Traditional
Poster Session - fMRI |
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fMRI: Acquisition Methods
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the poster (Not all posters are available for viewing.)
Thursday 10 May 2012
Exhibition Hall |
13:30 - 15:30 |
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2041. |
Simultaneous Measurement
of Signal Fluctuations in GE and SE BOLD data during Resting
State fMRI at 7T ![](poster.gif)
Jack Harmer1, Richard Bowtell1,
and Susan Francis1
1SPMMRC, The University of Nottingham,
Nottingham, Nottinghamshire, United Kingdom
Spontaneous, low frequency fluctuations in connected
networks have been identified in T2*-weighted
gradient-echo (GE) BOLD data. Here, we use a dual GE-SE-EPI
sequence at 7T to identify functional connectivity maps
in SE and GE BOLD data using ICA analysis. We assess the
correlation of signal fluctuations in the SE and GE
time-series, showing a higher correlation in the DMN
than in global grey matter. We calculate the ratio of
the changes in relaxation rates underlying the signal
fluctuations, δR2*/δR2, to be 1.910.30 in grey matter,
in good agreement with the value of ~2.1 found for
task-induced changes in motor cortex.
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2042. |
BOLD fMRI using a
cryogenic RF probe: A concept for studying temperature
perception in transgenic mouse models ![](poster.gif)
Henning Matthias Reimann1, Jan Hentschel1,
Babette Wagenhaus1, Andreas Pohlmann1,
and Thoralf Niendorf1,2
1Berlin Ultrahigh Field Facility (B.U.F.F.),
Max-Delbrück-Center for Molecular Medicine (MDC),
Berlin, Germany, 2Experimental
and Clinical Research Center (ECRC), a joint cooperation
between the Charité Medical Faculty and the Max-Delbrück-Center,
Berlin, Germany
Only little is known about the temperature perception
and regulation mechanisms in mammals. The combination of
fMRI and genetic modifications in rodents has great
potential to help elucidating the role of the various
proteins involved in the underlying pathways. Here we
demonstrate the successful adaptation of an MR-optimized
thermo-stimulation system to mice fMRI, which is of
particular interest considering the numerous transgenic
strains used in biomedical research of thermal
perception. Moreover this report is the first that
demonstrates fMRI activations for cold stimuli in mice.
Signal-to-noise ratio was enhanced by using a cryogenic
RF probe. Based on the concepts and results reported
here we anticipate to extend our fMRI explorations into
temperature perception and regulation mechanisms in mice
with the ultimate goal to characterize the cold sensing
transient receptor potential channel TRPM8.
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2043. |
A Brain Resting State fMRI
Connectivity Study Using High-Temperature Superconducting RF
Coil Platform in A 7T Rat MRI Imager ![](poster.gif)
Yen-Liang Liu1,2, Yun-An Huang1,
In-Tsang Lin1, Hong-Chang Yang3,
and Jyh-Horng Chen1,2
1Interdisciplinary MRI/MRS Lab, Department of
Electrical Engineering, National Taiwan University,
Taipei, Taiwan, 2Graduate
Institute of Biomedical Electronics and Bioinformatics,
National Taiwan University, Taipei, Taiwan, 3Department
of Physics, National Taiwan University, Taipei, Taiwan
A 4cm high-temperature superconducting (HTS)
radio-frequency (RF) coil platform was applied on the
fMRI study in a 7T MRI system. Not only the image SNR
but also the functional SNR were improved due to reduced
thermal noise. Compared to a similar home-made copper RF
coil, this study obtained an approximate twice SNR gain
in both fast spin echo and echo planar imaging (EPI)
sequences. The time-series analysis of the resting state
fMRI study showed that not only the functional SNR was
raised but also the functional connectivity was
improved.
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2044. |
Feasibility of Using
Simultaneous BOLD-ASL to Estimate the Magnitude of the CBF
Response to an Unknown Stimulus
Aaron Benjamin Simon1, and Richard Buxton2
1Department of Bioengineering, University of
California San Diego, La Jolla, CA, United States, 2Department
of Radiology, University of California San Diego, La
Jolla, CA, United States
We analyzed a novel method of quantitatively measuring
CBF fluctuations during complex behavior without
knowledge of stimulus dynamics, based on the combined
measurement of BOLD and CBF time series. We hypothesized
that projection of the ASL time series onto the BOLD
time series would separate ASL fluctuations due to CBF
from those due to noise. This method was tested on data
from a visual stimulus experiment and was found to
significantly remove noise from the ASL data, although
it produced a small underestimate of CBF fluctuations
due to the presence of noise in the BOLD signal.
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2045. |
MRI evaluation of metal
acupuncture needles ![](poster.gif)
Ling Mei1,2, Xiaojing Long*1, Qian
Huang2, Haibo Yu3, Yanjun Diao1,3,
Wanzhang Yang4, and Bensheng Qiu*1,5
1Paul C. Lauterbur Research Center for
Biomedical Imaging, Shenzhen Institutes of Advanced
Technology, Chinese Academy of Sciences, Shenzhen,
Guangdong, China,2Department of Electronic
and Information Engineering, South China University of
Technology, Guangzhou, Guangdong, China, 3Shenzhen
Hospital of TCM Affiliated Guangzhou University of TCM,
Shenzhen, Guangdong, China, 4Shenzhen
Nanshan Hospital, Shenzhen, Guangdong, China, 5Department
of Radiology, University of Washington School of
Medicine, Seattle, WA, United States
Three types of metal acupuncture needles were evaluated
with respect to MR imaging artifact and RF-induced
heating effect. The gold needle generated little
artifact, and the Austenitic stainless steel needle
produced moderate artifacts in both phantom and in-vivo
experiments. However, the traditional stainless steel
needle produced huge artifacts. The temperature of the
three needles in the phantom have no significant change
during a long time MR scanning. In conclusion, gold and
Austenitic stainless steel acupuncture needles are MR
compatible and safe, which can be used for systemic
research on the ancient acupuncture using a modern and
powerful MR imaging modality.
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2046. |
Sinusoidal echo-planar
imaging with parallel acquisition technique for reduced
acoustic noise in auditory fMRI ![](poster.gif)
Jascha Zapp1, Sebastian Schmitter2,
and Lothar R Schad1
1Computer Assisted Clinical Medicine,
Heidelberg University, Mannheim, Germany, 2Center
for Magnetic Resonance Research, University of
Minnesota, Minneapolis, United States
Acoustic scanner noise causes an unwanted BOLD signal in
the auditory cortex during fMRI and also poses a safety
issue. Conventional EPI produces high sound pressure
level (SPL) due to fast switching of trapezoidal
gradients. The aim of this work is to present an
enhanced sinusoidal EPI (sEPI) with PAT for reduced SPL.
We provide a comprehensive comparison of SPL
measurements between sEPI and conventional EPI for their
most feasible configurations. The sEPI PAT sequence
provides a reduction in SPL of up to 11.1dB and 5.1dB
compared to EPI PAT at 3T for matrix sizes of 64x64 and
128x128pixels, respectively.
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2047. |
Sensitivity and
Specificity Enhancement in High-Speed FMRI using Multi-Echo
Echo-Volumar Imaging ![](poster.gif)
Stefan Posse1,2, and Elena Ackley1
1Neurology, University of New Mexico,
Albuquerque, NM, United States, 2Electrical
and Computer Engineering, Physics and Astronomy,
University of New Mexico, Albuquerque, NM, United States
We introduce high-speed multi-echo EVI with 241 ms
temporal resolution and investigate the BOLD contrast
characteristics of parametric EVI images during visual
and motor tasks. Average T2* values in cortical areas
ranged from 30-60 ms, consistent with multi-echo EPI.
First and second echo images, T2* maps and weighted echo
average maps showed strong BOLD activation in visual and
motor cortex and supplementary motor area. The S0 maps
showed much smaller activation, predominantly in large
blood vessels, consistent with localized in-flow
effects. Multi-echo multi-slab EVI enables rapid mapping
of T2* and sensitive detection of brain activation and
in-flow effects.
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2048. |
Brain fMRI with dual echo
steady-state (DESS) imaging: preliminary findings on signal
behavior and flip-angle dependency ![](poster.gif)
Pei-Hsin Wu1, Hsiao-Wen Chung1,2,
Ming-Long Wu3,4, Tzu-Chao Chuang5,
and Tzu-Cheng Chao3,4
1Department of Electrical Engineering,
National Taiwan University, Taipei, Taiwan, 2Institute
of Biomedical Electronics and Bioinformatics, National
Taiwan University, Taipei, Taiwan, 3Department
of Computer Science and Information Engineering,
National Cheng Kung University, Tainan, Taiwan, 4Institute
of Medical Informatics, National Cheng Kung University,
Tainan, Taiwan, 5Department
of Electrical Engineering, National Sun Yat-Sen
University, Kaohsiung, Taiwan
Previous study demonstrates that optimization of image
contrast for morphological depiction using DESS imaging.
The sensitivity of DESS signals to functional brain
activations, however, has not been explored. In this
study, we report the preliminary results from phantom
and human experiments to investigate the relationship
between functional contrast and the imaging parameters
for S+ and S- images, respectively.
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2049. |
Direct SENSE imaging for
fast, multi-echo fMRI over a restricted field of view ![](poster.gif)
Mark Chiew1,2, and Simon J Graham1,3
1Medical Biophysics, University of Toronto,
Toronto, Ontario, Canada, 2Rotman
Research Institute, Toronto, Ontario, Canada, 3Imaging
Research, Sunnybrook Research Institute, Toronto,
Ontario, Canada
We present a novel method for fast acquisition of
densely-sampled multi-echo fMRI data over a restricted
field of view. The DSI (Direct SENSE Imaging) technique
employs a modified STEAM localization method for
selective excitation of a small number of voxels, and
uses direct sensitivity encoding for spatial separation
of measured signals. The readout requires no imaging
gradients as no Fourier encoding is performed, and the
received signals contain both T2 and T2* contrast. This
method is proposed as a promising alternative to
whole-brain approaches for fast imaging in targeted, ROI-based
fMRI.
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2050. |
Compressed Sensing
Improves BOLD Sensitivity at both the Individual & Group
Levels ![](poster.gif)
Steven D. Beyea1,2, Dan Holland3,
Careesa Liu1, Xiaowei Song1, Ryan
C.N. D'Arcy1,4, Tynan Stevens1,5,
Andy Sederman3, Lynn Gladden3, and
Chris V. Bowen1,2
1Institute for Biodiagnostics (Atlantic),
National Research Council Canada, Halifax, Nova Scotia,
Canada, 2Physics
& Radiology, Dalhousie University, Halifax, Nova Scotia,
Canada, 3Department
of Chemical Engineering & Biotechnology, University of
Cambridge, Cambridge, United Kingdom, 4Neuroscience
& Radiology, Dalhousie University, Halifax, Nova Scotia,
Canada, 5Physics,
Dalhousie University, Halifax, Nova Scotia, Canada
Compressed Sensing (CS) reconstruction of variable
density spiral fMRI acquisitions are evaluated. CS is
shown to improve fMRI sensitivity relative to
conventional density compensated re-gridding. Using CS,
it was demonstrated that, even when using a matched TR,
it is possible to obtain data using a 28% under-sampled
1-shot acquisition which exhibits no loss in fMRI
sensitivity compared to a uniformly sampled 2-shot
acquisition.
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2051. |
Compressed Sensing Enabled
Ultra-High Resolution Optogenetic Functional Magnetic
Resonance Imaging (ofMRI)
Nguyen Van Le1, Thanh Hai Nguyen1,
Xiaoyi Yu1, Zhongnan Fang1, and
Jin Hyung Lee1,2
1Department of Electrical Engineering,
University of California, Los Angeles, Los Angeles,
Califorinia, United States, 2Department
of Psychiatry and Biobehavioral Sciences, University of
California, Los Angeles, Los Angeles, California, United
States
ofMRI is a powerful new technology that enables precise
control of brain circuit elements while monitoring its
causal output. To bring ofMRI to it’s full potential, it
is essential to achieve high-spatial resolution with
minimal distortions. To this end, we combined compressed
sensing (CS) reconstruction with under-sampled
ultra-high-resolution b-SSFP fMRI, and fast spiral
readout. Under-sampling was performed by random
selection of 1 in 3 spiral interleaves. The CS object
function was designed to optimize data consistency and
L1 norm minimization in spatial and temporal dimensions.
The results demonstrate achievement of high-quality
high-resolution images with precise temporal dynamics
necessary for fMRI.
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2052. |
Curved Slice Functional
Imaging ![](poster.gif)
Hans Weber1, Daniel Gallichan1,
Jakob Assländer1, Jürgen Hennig1,
and Maxim Zaitsev1
1Department of Radiology, Medical Physics,
University Medical Center Freiburg, Freiburg, Germany
The ExLoc concept enables excitation and geometrically
matched spatial encoding of curved slices with variable
curvature, orientation and position. This allows a
better adaptation of the slice geometry to the anatomy
under investigation. In this study we apply the ExLoc
concept to echo planar imaging and present preliminary
results from a curved slice fMRI experiment.
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2053.
![](MAGNA25.jpg) |
A Flexible Framework of
Perfusion fMRI using Asymmetric Label and Control
Acquisitions with Background Suppressed pCASL GRASE
Lirong Yan1, Emily Kilroy1, and
Danny JJ Wang1
1Neurology, University of California, Los
Angeles, Los Angeles, California, United States
Perfusion fMRI using arterial spin labeling (ASL) is
advantageous for quantifying perfusion both at rest and
during task activation. However, it is limited by low
temporal resolution and sensitivity. With
pseudo-continuous ASL (pCASL) with background suppressed
(BS) 3D GRASE, the temporal resolution and sensitivity
of perfusion fMRI can be improved by skipping control
acquisitions without compromising the quantification of
cerebral blood flow. In this study, a flexible framework
of perfusion fMRI was introduced by using asymmetric
label and control acquisitions in pCASL with BS 3D GRASE
which was validated using visual cortex stimulation.
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2054. |
Inherent and Dynamic B0 Mapping
and Deblurring in SENSE Spiral Imaging and Application to
Resting-State fMRI ![](poster.gif)
Trong-Kha Truong1, and Nan-kuei Chen1
1Brain Imaging and Analysis Center, Duke
University, Durham, NC, United States
Spiral imaging is vulnerable to spatial and temporal
variations of the static magnetic field (B0)
caused by susceptibility effects, subject motion,
physiological noise, and/or system instabilities,
resulting in image blurring. Previously proposed
deblurring methods rely on separately acquired B0 maps,
which increases the scan time and precludes the
correction of temporal B0 variations.
Here, we propose a novel k-space energy spectrum
analysis method that can inherently and dynamically
generate a B0 map
from SENSE spiral k-space data at each time point,
without requiring any additional data acquisition or
pulse sequence modification, and demonstrate its
effectiveness in resting-state fMRI experiments.
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2055. |
Dynamic unwarping of EPI
geometric distortions using Interleaved Dual Echo with
Acceleration (IDEA) EPI ![](poster.gif)
Benedikt Andreas Poser1, and V Andrew Stenger1
1UH-QMC Neuroscience and MR Research Program,
University of Hawaii, Honolulu, Hawaii, United States
BOLD fMRI usually employs EPI, which suffers from
distortions caused by field inhomogeneity. Most
correction methods rely on some form of reference data
acquired at the start. Subject motion during the scan
may invalidate this reference as distortion changes with
head position. Ability to dynamically update correction
parameters may therefore be beneficial. We show that
dynamic correction can achieved using IDEA EPI,
originally intended for Nyquist ghost compensation. Two
images are simultaneously sampled under the positive and
negative readout gradients. Their ΔTE of one echospacing
(0.5–0.9ms) allows fieldmaps to be calculated from each
volume. Phantom and in vivo examples are shown and
compared to conventional fieldmap correction.
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2056.
![](MAGNA25.jpg) |
Moving Fluid Suppressed
BOLD Signals Using DANTE Prepared Multislice EPI
Linqing Li1, Christine Law1,
Yazhuo Kong1, Michael Kelly1,
Jamie Near1, and Peter Jezzard1
1FMRIB, Clinical Neurology Department,
University of Oxford, Oxford, United Kingdom
We propose the employment of DANTE prepared multislice
EPI (DANTE-EPI) for whole brain BOLD signal measurement.
Based on the flow suppression feature of DANTE, we
hypothesize that the intravascular BOLD signal will be
largely suppressed and thus the venous blood
contamination reduced. As such, the BOLD signal from
DANTE-EPI may be more accurately located to the site of
neuronal activity.
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2057. |
Steady State Free
Precession (SSFP) and fMRI: Expressions Accounting for
Reversible vs Irreversible Transverse Relaxation Effects
Robert V. Mulkern1, Mukund Balasubramanian1,
Dimitrios Mitsouras2, and Stephen Haker2
1Department of Radiology, Children's Hospital
Boston, Boston, Massachusetts, United States, 2Department
of Radiology, Brigham and Women's Hospital, Boston,
Massachusetts, United States
Reversible relaxation processes resulting from inherent
frequency distributions have been incorporated into SSFP
signal analyses to separately examine how changes in
either reversible or irreversible transverse relaxation
affect SSFP based fMRI signal intensities. The analytic
expressions obtained for Lorentzian, Gaussian and square
distributions were derived using a single sum series
expansion previously unnoted which allowed for a closed
form solution for the Lorentzian and rapidly converging
solutions for Gaussian and square distributions. The
expressions should be useful for allowing detailed
investigations of mechanisms affecting SSFP based fMRI
studies in either transition band or passband modes.
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2058. |
Blipped “yz-Shimming” to
Correct for Geometric Distortions in Echo-Planar Imaging of
the Human Spinal Cord ![](poster.gif)
Jürgen Finsterbusch1,2
1Department of Systems Neuroscience,
University Medical Center Hamburg-Eppendorf, Hamburg,
Germany, 2Neuroimage
Nord, University Medical Centers Hamburg-Kiel-Lübeck,
Hamburg-Kiel-Lübeck, Germany
Magnetic field inhomogeneities and susceptibility
differences cause geometric distortions in echo-planar
imaging that are related to the phase modulation induced
during the echo train. Here, an approach involving
additional blip gradient pulses in the phase and readout
direction (“yz-shimming”) is presented that aims to
compensate these unwanted phase modulations and, thus,
corrects for the geometric distortions. Its feasibility
is demonstrated in a phantom and the human spinal cord
in vivo.
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2059. |
Simulation of optimal echo
times to maximize BOLD sensitivity in the orbitofrontal
cortex for fMRI
Sebastian Domsch1, and Lothar R. Schad1
1Computer Assisted Clinical Medicine,
Heidelberg University, Mannheim, Germany
The orbitofrontal cortex (OFC), important for
decision-making and reward processing, is affected by
susceptibility gradients (SG) causing signal drop outs
and image distortions in fMRI using EPI. In subcortical
brain areas, BOLD sensitivity (BS) depends critically on
echo time (TE). In this work, optimal TE for single EPI
slices are calculated via BS simulations considering
local T2star and SG values to maximize BS in the OFC. It
shows that optimal TEs increase in foot-head direction
from about 20ms to 40ms for AC-PC section orientation.
Further, the results show good consistency over all
subjects.
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2060. |
T2*-Weighted Echo-Planar
Imaging of Inner Fields-of-View Using 2D-Selective RF
Excitations ![](poster.gif)
Jürgen Finsterbusch1,2
1Department of Systems Neuroscience,
University Medical Center Hamburg-Eppendorf, Hamburg,
Germany, 2Neuroimage
Nord, University Medical Centers Hamburg-Kiel-Lübeck,
Hamburg-Kiel-Lübeck, Germany
With spatially 2D-selective RF excitations rectangular
profiles can be excited which can be used to acquire
inner fields-of-view without phase-encoding aliasing.
Thus, geometric distortions in echo-planar imaging that
are caused by magnetic field and susceptibility
inhomogeneities, can be reduced for small target
regions. In the present study, two approaches are
investigated that either involve a FID sequence or a
spin-echo-based acquisitions with an echo train shift.
The feasibility of both approaches to acquire
high-resolution T2*-weighted echo-planar images of inner
fields-of-view with minimum distortions is shown.
Furthermore, their applicability to functional
neuroimaging is demonstrated.
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2061. |
Reduced image distortions
in fMRI using accelerated EPIK sequence at 3T
Seong Dae Yun1, Martina Reske1,
Kaveh Vahedipour1, Tracy Warbrick1,
and N. Jon Shah1,2
1Institute of Neuroscience and Medicine - 4,
Forschungszentrum Jülich, Jülich, Germany, 2JARA
- Faculty of Medicine, RWTH Aachen University, Aachen,
Germany
EPI is in widespread use in MR studies acquiring time
series data due to its capability of achieving a
relatively high temporal resolution. However, the fact
that EPI acquires echoes with evolving time delays makes
it prone to severe image distortions. To overcome this
issue, EPIK (EPI with Keyhole) accelerated using GRAPPA
was tested at 3T. This EPIK variant offers a higher
temporal resolution and robustness against field
inhomogeneities when compared to interleaved EPI and
single-shot EPI, respectively. The performance of the
method was validated with human functional MRI
measurements as well as MRI simulation results using
JEMRIS.
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2062. |
Improvement of 3D
PRESTO-SENSE fMRI sensitivity using 32-channel head coil
Renaud Lopes1, Aurelien Monnet1,
and Xavier Leclerc1
1CHRU Lille, Neuroradiology service, Lille,
Nord, France
In this study, we assess the potential impact of
32-channel head coil on the results of a fMRI paradigm
with 3D PRESTO-SENSE sequence. fMRI results obtained
with 32-channel head coil were compared to those
obtained with 8-channel head coil. Model-based and
data-driven analyses were used in order to compare the
statistical power of activity detection for each coil.
In this study, it was demonstrated that 3D PRESTO-SENSE
with 32-channel head coil can be used for fMRI studies.
Higher fMRI sensitivity was found compared to the same
sequence with 8-channel head coil.
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2063. |
Multi-echo magnetic
resonance inverse imaging improves the sensitivity of BOLD
signal detection
Kevin Wen-Kai Tsai1, Thomas Witzel2,
Wei-Jui Kuo3, and Fa-Hsuan Lin1,2
1Institute of Biomedical Engineering,
National Taiwan University, Taipei, Taiwan, Taiwan, 2Athinoula
A. Martinos Center for Biomedical Imaging, Massachusetts
General Hospital, Charlestown, MA, United States, 3Institute
of Neuroscience, National Yang-Ming University, Taipei,
Taiwan, Taiwan
Functional MRI experiments using EPI should tune the
echo time (TE) to local T2* value in order to optimize
the BOLD signal sensitivity. Since the T2* values are
different across the whole brain, acquisitions using one
single TE may not be optimal. Using experimental data,
we demonstrate that, the InI can use different TEs
across acquisitions to improve the sensitivity of
detecting BOLD signal and obtain hemodynamic response
estimates of 100 ms temporal sampling, reasonable
spatial resolution, and whole-brain coverage.
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2064. |
Robustness and
Reproducibility of PTX 3DTRF Pulse Design for Ultra High
Field fMRI ![](poster.gif)
Hai Zheng1, Lei Sheu2,3, Tiejun
Zhao4, Yongxian Qian5, Tamer
Ibrahim1,5, Howard Aizenstein1,2,
and Fernando Boada1,5
1Bioengineering, University of Pittsburgh,
Pittsburgh, Pennsylvania, United States, 2Psychiatry,
University of Pittsburgh, Pittsburgh, Pennsylvania,
United States, 3Psychology,
University of Pittsburgh, Pittsburgh, Pennsylvania,
United States, 4Siemens
Medical Solutions USA, Pittsburgh, Pennsylvania, United
States, 5Radiology,
University of Pittsburgh, Pittsburgh, Pennsylvania,
United States
T2* weighted BOLD fMRI in ultra high field (UHF) is
hampered by susceptibility-induced signal loss between
air cavities and brain tissues. In this article, we
proposed a new RF pulse design strategy, dubbed as PTX
3DTRF, by combing 3DTRF method and PTX technique to
simultaneously and precisely recover multi-slice signal
loss and improve BOLD signal. Significant improvement in
UHF human study can be observed when the proposed
methods are applied. Robustness and reproducibility are
proved by scanning multiple subjects (N=5) and multiple
times on one subject (two of the five subjects were
scanned twice, respectively).
|
2065. |
Frontal Cortex fMRI at 7T:
Escaping Flat Minimum Traps in Higher-Order B0 Shimming
Algorithms ![](poster.gif)
Ariane Fillmer1, Milan Scheidegger1,2,
Peter Boesiger1, and Anke Henning1
1Institute for Biomedical Engineering,
University and ETH Zurich, Zurich, ZH, Switzerland, 2Clinic
of Affective Disorders and General Psychiatry,
University Hospital of Psychiatry Zurich, Zurich, ZH,
Switzerland
To make use of the full capacity of fMRI applications in
ultra-high field strengths, an excellent B0 shimming is
inevitable. Usually these applications suffer from major
distortions and signal drop-outs in the frontal cortex
area. This work presents a modified approach of B0
shimming, which enables the restoration of signal in the
frontal cortex and therefore renders fMRI applications
in the frontal cortex possible.
|
2066. |
Integration of Concurrent
Real-time fMRI and EEG data: Simultaneous Real-time fMRI and
EEG Neurofeedback ![](poster.gif)
Jerzy Bodurka1, Vadim Zotev1,
Raquel Phillips1, and Han Yuan1
1Laureate Institute for Brain Research,
Tulsa, Oklahoma, United States
We describe the system we implemented on commercial MRI
and EEG equipment in which we achieved integration of
concurrent real-time fMRI (rtfMRI) and
electroencephalography (EEG) data for the purpose of
simultaneous rtfMRI-EEG neurofeedback. This
first-of-its-kind real-time simultaneous fMRI and EEG
multimodal neurofeedback (rtfMRI-EEG-mnf) approach
allows research participants to receive information
about their cerebral electrophysiological and
hemodynamic activity in real-time and to then use this
information to volitionally self-regulate neural
responses. This system can be used in the development of
novel cognitive neuroscience research paradigms and
novel enhanced cognitive therapeutic approaches for
major psychiatric disorders.
|
2067. |
Optimization of
diffusion-weighted fMRI at 3T MRI compare with BOLD-fMRI ![](poster.gif)
Li-Ming Hsu1, Kuan-Hung Cho2,
Cyril Poupon3, Denis Le Bihan3,
and Ching-Po Lin1,4
1Department of Biomedical Imaging and
Radiological Sciences, National Yang-Ming University,
Taipei, Taiwan, 2Instrumentation
Resource Center, National Yang-Ming University, Taipei,
Taiwan, 3NeuroSpin,
IFR 49 CEA Saclay, Gif-sur-Yvette, France, 4Institute
of Neuroscience, National Yang-Ming University, Taipei,
Taiwan
To optimize the diffusion-fMRI at different b-values by
considering the signal performance compared with BOLD-fMRI
during visual stimulation. The results show that the
DfMRI at b-value = 1,200 s/mm2 should be a better
choice than b-value = 600 and 1,800 s/mm2. DfMRI
could provides the chance to approach the neuron
activation than hemodynamic response.
|
2068. |
High spatial and temporal
resolution fcMRI with BOLD selectivity using multiecho
simultaneous multislice EPI ![](poster.gif)
Valur Olafsson1, Jia Guo1, Chi Wah
Wong1, Prantik Kundu2, Souheil
Inati3, Wen-Ming Luh3, Vinai
Roopchansingh3, Noah Brenowitz2,
Peter Bandettini2,3, Eric Wong1,
and Thomas Liu1
1UCSD Center for Functional MRI, La Jolla,
CA, United States, 2Section
on Functional Imaging Methods, NIMH, Bethesda, MD,
United States, 3Functional
MRI Facility, NIMH, Bethesda, MD, United States
Motion and physiological noise confounds are key factors
that limit the sensitivity of resting-state functional
connectivity MRI (fcMRI) measures. The acquisition of
multiple echoes has been shown to be effective for
automatically identifying and removing these confounds.
However, the acquisition of multiple echoes requires
additional readout time and leads to a decrease in
temporal resolution. To address this issue, we have used
a simultaneous multislice excitation strategy to
compensate for the extra readout time and achieve whole
brain coverage with 3 echoes, 2 mm isotropic resolution,
and a TR of 2 seconds.
|
2069. |
Brain Circuit Analysis
with Real-Time Optogenetic Functional Magnetic Resonance
Imaging (rt-ofMRI)
Zhongnan Fang1, and Jin Hyung Lee1,2
1Department of Electrical Engineering,
University of California, Los Angeles, Los Angeles,
California, United States, 2Department
of Psychiatry and Biobehavioral Sciences, University of
California, Los Angeles, Los Angeles, California, United
States
Here we present a novel real-time optogenetic functional
magnetic resonance imaging (ofMRI) method. ofMRI is a
novel technology, which enables systematic analysis of
brain circuits by using optogenetic stimulation as
input, and fMRI readout as output. Real-time ofMRI (rt-ofMRI)
aims to provide real-time brain circuit analysis
capabilities using ofMRI. Our goal is to acquire,
reconstruct, motion correct, and analyze ofMRI images in
real-time. This approach enables high-throughput ofMRI
studies with live activation feedback on image quality,
motion characteristics, and optogenetic stimulation
response. It prevents long offline processing and
facilitates interactive experiment parameter selection
(e.g. stimulation frequency, isoflurane level, etc.).
|
2070. |
The Origins of fMRI
Contrast in SPEN Imaging at Ultra High Magnetic Fields
Eddy Solomon1, Nadya Pyatigorskaya2,
Peter Bendel1, Denis Le Bihan2,
Luisa Ciobanu2, and Lucio Frydman1
1Weizmann Institute of Science, Rehovot,
Israel, 2Neurospin,
CEA, Saclay, France
This presentation examines the origin of the
function-derived activation detected by SPEN fMRI, with
a series of preclinical high (7T) and ultra-high (17.2T)
magnetic field studies. Artifact-free images of a rat’s
head with good resolution in all areas and localized
activation maps were obtained in a single scan using a
variety of SPEN sequences. Our data shows that, besides
the normal T2*-weighted BOLD contribution which arises
in non-refocused sequences, fMRI SPEN signals contains a
strong component caused by apparent T1-related inflow
effects. This contribution can be modulated by varying
the scanning repetition rate; measurements at 7T support
this finding.
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2071.
![](MAGNA25.jpg) |
Significant reduction in
ADC during enhanced neuronal activity in isolated spinal
cord of newborn rat ![](poster.gif)
Nitzan Tirosh1, and Uri Nevo1
1Biomedical Engineering, Tel Aviv University,
Tel Aviv, Israel
Isolated and viable spinal cords of newborn rats were
used to investigate whether the changes in DWI signal
during neuronal activation originate from biophysical
mechanisms linked to neuronal activity or related to
vascular effects. DW images were acquired with three
diffusion times and along three diffusion directions
during three physiological phases: Spontaneous activity,
chemically induced enhanced activity and return to
baseline activity. Reduction of 18-27% in the average
ADC was observed during elevated neuronal activity.
These results suggest that electrical activity affects
water displacement in neurons and these changes are not
an MR artifact due to a vascular effect.
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2072.
![](MAGNA25.jpg) |
Susceptibility-induced
increase of apparent diffusion coefficient: BOLD effect
behind diffusion fMRI
Dmitry S. Novikov1, Marco Reisert2,
and Valerij G. Kiselev2
1Radiology, NYU School of Medicine, New York,
NY, United States, 2Radiology,
University Medical Center Freiburg, Germany
NMR diffusion measurements are confounded by
heterogeneous microscopic magnetic susceptibility. It is
known that apparent diffusion coefficient (ADC) is
smaller in this case than the genuine diffusivity when
diffusion is slow. We discover a more general effect:
ADC over- or underestimates the genuine diffusivity when
diffusion is fast depending on the pulse sequence. Our
theory agrees with Monte Carlo simulations in
computer-generated capillary network. The ~5% change in
the simulated ADC quantitatively explains the observed
DWI signal changes both in hypercapnia and under
neuronal activation, suggesting that BOLD effect is
sufficient for rationalizing the “diffusion fMRI”
phenomenon.
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Traditional
Poster Session - fMRI |
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Click on
to view
the abstract pdf. Click on
to view
the poster (Not all posters are available for viewing.)
Thursday 10 May 2012
Exhibition Hall |
13:30 - 15:30 |
|
|
2073. |
A Distributed Dipole Model
for Estimating Epileptiform Magnetic Fields in Brain Tissue ![](poster.gif)
Padmavathi Sundaram1, Darren Orbach1,
Robert Mulkern1, Mukund Balasubramanian1,
and William Wells2
1Radiology, Children's Hospital Boston,
Harvard Medical School, Boston, MA, United States, 2Radiology,
Brigam and Women's Hospital, Harvard Medical School,
Boston, MA, United States
In past work, we imaged epileptiform events using
gradient-echo EPI and found fast MR phase changes that
suggested 183 nT local magnetic fields inside neuronal
tissue. Here we attempt to determine whether these
fields are compatible with electrophysiology in
epilepsy. Nature and strengths of magnetic fields inside
the brain are largely unknown. All empirical
measurements are done using MEG and are of magnetic
fields outside the brain.
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2074. |
Voxel-wise Tissue
Segmentation and Partial Volume Quantification in
Experimental EPI Space to Inform fMRI and fcMRI Analysis ![](poster.gif)
Daniel L Shefchik1, Andrew S Nencka1,
Andrzej Jesmanowicz1, and James S Hyde1
1Biophysics, Medical College of Wisconsin,
Milwaukee, WI, United States
Tissue segmentation for functional MRI studies is
normally performed with FreeSurfer, which utilizes T1
weighted anatomical images to provide tissue separation
maps. The anatomical separation maps have a different
image warping than EPI images and can lead to incorrect
image registration. A different tissue separation method
utilizes the GREASE-II sequence to produce T1, T2, and
T2’ relaxivity maps in the same EPI space as functional
studies. The three EPI relaxivity maps produce CSF, gray
and white matter maps by using their mean relaxivity
values. Tissue maps are combined to view the Partial
volume effect throughout the brains gray matter.
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2075. |
A real-time event-related
hyperscan-fMRI software system ![](poster.gif)
Sebastian Baecke1, Michael Luehrs1,
Ralf Luetzkendorf1, and Johannes Bernarding1
1Biometrics and Medical Informatics,
Otto-von-Guericke University, Magdeburg, Sachsen-Anhalt,
Germany
We have developed an adaptive hyper-scanning software
system, that combine two (or more) MR scanner in real
time. The activation of the two volunteers can be
analysed in real time and used on a brain-computer
interface for controlling various paradigms. The biggest
advantage here is the direct feedback to the subjects
which may then influence their own brain activity and
thus the development and optimization of their own
strategies to increase their neural response. Here we
present the first results of a feasibility study for
social interaction connecting a 3T and 7T MR scanners.
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2076. |
A novel temporal filtering
strategy for functional MRI using UNFOLD
Sebastian Domsch1, Andreas Lemke1,
Sebastian Weingärtner1, and Lothar R. Schad1
1Computer Assisted Clinical Medicine,
Heidelberg University, Mannheim, Germany
UNFOLD to increase sampling rates in fMRI to detect
transient BOLD signal modulations requires temporal
filtering before statistical mapping in the time domain
is carried out. Low-pass filtering and zero-filling has
been proposed. Both strategies are non-optimal since
low-pass filtering degrades temporal resolution and
zero-filling leads to serial correlations (non-white
noise) known to bias linear modeling of neuronal
responses. We propose a more sophisticated temporal
filtering strategy intrinsically avoiding non-white
noise to increase statistical inference.
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2077. |
Effect of Distortion
Correction on Group Level Statistics in FMRI of Medial
Temporal Lobe
Jarle Ladstein1, Hallvard Røe Evensmoen2,
Asta Kristine Håberg2, Anders Kristoffersen3,
Dominic Holland4, Anders M Dale4,5,
and Pål Erik Goa3
1MI Lab and Department of Circulation and
Medical Imaging, Norwegian University of Science and
Technology, Trondheim, Norway, 2Department
of Neuroscience, Norwegian University of Science and
Technology, Trondheim, Norway, 3Clinic
of Radiology, St. Olavs University Hospital, Trondheim,
Norway, 4Department
of Neurosciences, The University of California, San
Diego, United States, 5Department
of Radiology, The University of California, San Diego,
United States
Geometric distortions in functional EPI scans cause
local misregistration between functional and anatomical
images. This can decrease the power of functional group
level analysis in regions with much distortion. To
evaluate the effect of applying a distortion correction
to the functional data, 25 subjects were scanned during
a special encoding paradigme and the data analyzed both
with and without applying a correction estimated from
reverse gradient scans. In regions of interest in the
entorhinal cortex the degree of distortion was high and
using distortion corrected data had a positive effect in
terms of increased activation volume and peak z-volume.
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2078. |
Influence of the choice of
the impulse response function in statistical analysis of
diffusion fMRI time series at high b-value ![](poster.gif)
Emilie Vallée1, Live Eikenes2,
Anders Kristoffersen3, and Asta K Håberg2,3
1MI Lab, Department of Circulation and
Medical Imaging, Norwegian University of Science and
Technology, Trondheim, Norway, 2Department
of Neuroscience, Norwegian University of Science and
Technology, Trondheim, Norway, 3MI
Lab, Department of Medical Imaging, St. Olavs Hospital,
Trondheim, Norway
Diffusion functional MRI has been proposed as a method
that detects true neuronal activity as changes in the
grey matter diffusion properties. Due to the high level
of noise present in the data, the origin of the
diffusion signal remains uncertain. Data was analyzed
using a response function modeling the diffusion process
(DRF) and the vascular process (HRF). Though the average
time-course from DRF analysis showed a 3s earlier and
steeper rise than the one from HRF analysis (= BOLD
signal), noise measurements suggested that the observed
shift was caused by correlated noise (physiological and
artefactual) present in the data.
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2079. |
Small scale functional
activations using a non-linear, population-specific brain
model and 3D EPI at 7 Tesla
Günther Grabner Grabner1,2, Benedikt Andreas
Poser2, Siegfried Trattnig1, and
Markus Barth2
1Department of Radiology, Medical University
Vienna, Vienna, Vienna, Austria, 2Donders
Institute for Brain, Cognition and Behaviour, Radboud
University Nijmegen, Nijmegen, Netherlands
Due to the availability of high field scanners and novel
imaging methods, high resolution, whole brain fMRI
becomes feasible. However, for performing fMRI group
analyses spatial smoothing is necessary to account for
inter-individual anatomical variation. Here, we
investigate the possibility to build a high resolution,
group specific anatomical template (model) directly from
the functional T2* weighted data acquired at 7 Tesla.
The purpose of this model is two fold; first, spatial
smoothing can be kept at a low level and second,
misregistration between distorted functional and
anatomical data is avoided.
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2080. |
Optimization of ICA for
detection of weak and focal activations in fMRI
Waqas Majeed1,2, Feng Wang1,2,
Robert M Friedman3, Chaohui Tang1,2,
and Malcolm J Avison1,2
1Vanderbilt University Institute of Imaging
Science (VUIIS), Vanderbilt University, Nashville, TN,
United States, 2Department
of Radiology, Vanderbilt University, Nashville, TN,
United States, 3Department
of Psychology, Vanderbilt University, Nashville, TN,
United States
In this study, we describe an approach for detecting
weak and focal activity patterns in fMRI data. High
resolution cerebral blood volume weighted images were
acquired from squirrel monkeys during tactile
stimulation of digits 1 and 3. The data were
preprocessed to enhance effective contrast-to-noise
ratio, and the model order was estimated in a
data-driven fashion (based upon stability of the
principal modes). Activation patterns associated with
stimulation of individual digits were successfully
detected using ICA. In future, we intend to use this
approach to investigate the presence of local functional
connectivity networks within the somatosensory cortex of
squirrel monkeys.
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2081. |
Parameter Estimation of
the BOLD fMRI model within a general Particle Filter
framework ![](poster.gif)
Imali Thanuja Hettiarachchi1, Shady Mohamed1,
and Saeid Nahavandi1
1Centre for Intelligent Systems Research,
Deakin University, Geelong, VIC, Australia
This work demonstrates a novel Bayesian learning
approach for model based analysis of Functional Magnetic
Resonance (fMRI) data. We use a physiologically inspired
hemodynamic model and investigate a method to
simultaneously infer the neural activity together with
hidden state and the physiological parameter of the
model. This joint estimation problem is still an open
topic. In our work we use a Particle Filter accompanied
with a kernel smoothing approach to address this problem
within a general filtering framework. Simulation results
show that the proposed method is a consistent approach
and has a good potential to be enhanced for further fMRI
data analysis.
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2082. |
Retinotopy using
multifocal fMRI with a correlation-based approach ![](poster.gif)
Yao-Wen Chang1, and Teng-Yi Huang1
1Dept. of EE, National Taiwan University of
Science and Technology, Taipei city, Taiwan
This study investigated the multifocal fmri method for
retinotopy mapping. Different from the previous studies
employing m-sequence, we utilized a correlation approach
to create stimulus series. This approach can be used to
comprise the hemodynamic response function of BOLD
effect in the generated series. In our preliminary
result, we were able to acquire local signals in V1 from
each of the 60 stimulated regions.
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2083. |
Modelling and Removing the
Gradient Artefact using a Gradient Model Fit (GMF) ![](poster.gif)
Glyn S Spencer1, Karen J Mullinger1,
Andrew Peters1, and Richard Bowtell1
1SPMMRC, School of Physics and Astronomy,
University of Nottingham, Nottingham, Nottinghamshire,
United Kingdom
The EEG gradient artefact (GA) is formed from a linear
superposition of individual artefacts generated by the
orthogonal gradients. Variations in position of the head
and/or EEG leads scale the relative weighting of the
artefact contribution from the different gradient
channels. Here we verify this concept and use it to
introduce a novel GA correction method, which is based
on a gradient model fit (GMF). Our results show that GMF
performs better than conventional GA correction methods
at high frequency when subject movement occurs,
potentially providing a more robust method for GA
correction when investigating gamma (30-150Hz) frequency
neuronal activity.
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2084. |
Short TE fMRI data:
removing motion and physiological noise confounds from BOLD
fMRI ![](poster.gif)
Molly Gallogly Bright1, and Kevin Murphy1
1CUBRIC, School of Psychology, Cardiff
University, Cardiff, United Kingdom
FMRI data reflect noise sources in addition to neuronal
activation, and their relative contributions depend on
the echo time (TE). Short TE data may contain
information related to motion and physiology, and could
potentially correct BOLD-weighted fMRI data for these
confounds. We used a dual-echo sequence to
simultaneously record fMRI data at short and
BOLD-weighted TEs, introducing head nodding, breathing
challenges, and visual stimulation to characterize their
effects on both datasets. Significant correlations were
observed between short TE data and “noise” regressors.
Using short TE data to correct BOLD-weighted data
(replacing motion correction regressors) increased the
significance of activation maps.
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2085. |
Characterization of the
effects of task-correlated facial and head movements in fMRI
Jeremy F Maglandd1, and Anna Rose Childress2
1Department of Radiology, University of
Pennsylvania, Philadelphia, PA, United States, 2Department
of Psychiatry, University of Pennsylvania, Philadelphia,
PA, United States
It is generally assumed that facial movements occur
randomly throughout the fMRI scan. However, since humans
use facial movements to express emotion, task-correlated
movement cannot be ruled out. Eight healthy volunteers
were instructed to move systematically during fMRI
examinations, with various types of movements of the
eyes (open/close, squint), face (smile/frown, clench
jaw), and body. Standard fMRI analyses were performed to
identify ‘false activations’. The facial movements
resulted in several brain regions having high
statistical significance. Jaw clenching yielded the
characteristic false activation in the region
surrounding the temporal muscles. These data may be used
to characterize the potential confounding effects of
systematic movements during an fMRI exam.
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2086. |
Sub-volume utilization
method for retrospective motion correction in long
acquisition fMRI ![](poster.gif)
Joong Il Kim1,2, Haewon Nam3,
Jeong Hoon Ko2, and Hae-Jeong Park1,2
1BK21 Project for Medical Science, Yonsei
University College of Medicine, Seoul, Korea, 2Department
of Diagnostic Radiology, Nuclear Medicine and Research
Institute of Radiological Science, Seoul, Korea, 3Medical
Research Institute, Ewha Womans University, Seoul, Korea
Motion during long-acquisition interleaved EPI sequence
was detected using both discontinuity measure defined by
the authors and realignment parameters. Retrospective
correction of motion artifact was achieved by sub-volume
utilization, which takes advantage of the interleaved
characteristics of the acquired sequences. Discontinuity
measure and realignment parameter respectively detected
inter-volume and intra-volume motion, and thereby
complemented each other. The proposed method is
especially useful in long-acquisition studies where
motion can severely affect image quality..
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2087. |
Regression of
Physiological Signals Using Phase-Constrained Inverse
Imaging in Functional MRI ![](poster.gif)
Rasim Boyacioglu1, and Markus Barth1
1Donders Institute for Brain, Cognition and
Behaviour, Radboud University, Nijmegen, Netherlands
Phase-constrained inverse imaging (pcInI) combines
inverse imaging (InI) and phase-constrained
reconstruction. Performance of pcInI is assessed with a
moving dots functional paradigm. A phase regressor is
obtained for each coil channel and used as confound
regressors in the analysis (either individually or after
averaging). On group average, cluster size and maximum
z-scores increase 52% and 10% (average regressor) and
534% and 36% (individual regressors) with respect to the
case with no regressors.
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2088. |
Comparison of Thermal and
Physiological Noise Amplification in Accelerated and
Segmented EPI Acquisitions ![](poster.gif)
Christina Triantafyllou1,2, Jonathan R
Polimeni2, Jennifer A McNab2,
Thomas Witzel2, and Lawrence L Wald2,3
1A.A. Martinos Imaging Center, McGovern
Institute for Brain Research, Massachusetts Institute of
Technology, Cambridge, MA, United States, 2A.A.
Martinos Center for Biomedical Imaging, Department of
Radiology, MGH, Charlestown, MA, United States, 3Harvard-MIT
Division of Health Sciences and Technology, Cambridge,
MA, United States
In this study, we compare two different acquisitions;
Accelerated (GRAPPA) single-shot and non-accelerated
mutli-shot EPI with matched effective echo spacing. Our
findings demonstrate that in both thermal and
physiological noise dominated acquisitions, when the
temporal sampling interval is matched, by temporally
smoothing the single-shot time-series, the single-shot
accelerated time-series result in higher tSNR. But if
the fixed duration scan can afford reduced temporal
resolution (sampling interval not matched), then the
slower multi-shot strategy provides slightly higher tSNR
than the distortion matched single-shot acquisition.
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2089. |
Physiological noise
covariance across receiver channels explains time-series SNR
model for RF coil array fMRI data
Jonathan R. Polimeni1, Christina
Triantafyllou1,2, and Lawrence L. Wald1,3
1Athinoula A. Martinos Center for Biomedical
Imaging, Department of Radiology, Harvard Medical
School, Massachusetts General Hospital, Charlestown, MA,
United States, 2A.
A. Martinos Imaging Center, McGovern Institute for Brain
Research, Massachusetts Institute of Technology,
Cambridge, MA, United States, 3Harvard-MIT
Division of Health Sciences and Technology,
Massachusetts Institute of Technology, Cambridge, MA,
United States
The original model for relating image SNR to temporal
SNR demonstrated that physiological noise scales
linearly with signal level, providing a quantitative
relationship between image SNR and temporal SNR.
Recently it has been demonstrated that fMRI data
acquired with multi-channel array coils deviates from
the standard model and the deviation appears to increase
with element count. Here we consider the effects of
physiological noise correlations across coil channels.
Extending the physiological noise model to include a
physiological covariance matrix can explain the observed
deviation of the data from the Kruger model and provides
an interpretation of the recently proposed models.
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2090. |
Cardiac artifacts around
the brainstem in fMRI studies ![](poster.gif)
Chisato Suzuki1, Kenichi Ueno1, R.
Allen Waggoner2, and Kang Cheng1,2
1fMRI Support Unit, RIKEN-Brain Science
Institute, Wako-shi, Saitama, Japan, 2Laboratory
for Cognitive Brain Mapping, RIKEN-Brain Science
Institute, Wako-shi, Saitama, Japan
Cardiac artifacts are a major contributor to noise in
BOLD studies of deep brain structures. The aim of this
study was to evaluate the effect of this artifact with
MPRAGE and EPI images. By reordering the k-space data
based on the cardiac cycle timing, we revealed signal
components synchronized to cardiac pulses. In contrast
to EPI data that showed widely distributed artifacts in
and around the brainstem, no heartbeat-synchronized
signal was found in T1W data. These results suggest that
rather than physical motion the main component of the
artifacts is from sources such as CSF flow and the
vessel pulsation.
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2091. |
Retrospective Corrections
for 3D FMRI: RETROICOR or RETROKCOR? ![](poster.gif)
Rob H.N. Tijssen1,22, and Karla L. Miller1
1FMRIB Centre, Oxford University, Oxford,
United Kingdom, 2University
Medical Center Utrecht, Utrecht, Netherlands
Recent renewed interest in 3D acquisition methods for
FMRI poses the question whether retrospective
corrections are better performed in image space (RETROICOR
or k-space (RETROKCOR). As 3D acquisitions typically use
multi-shot readouts in which the data are combined over
a period of several seconds one could argue that a
k-space based correction is more appropriate. It was
found, however, that RETROICOR performs equally well
compared to RETROKCOR suggesting that a single
cardiac/respiratory phase for the entire volume is
sufficient to generate suitable nuisance regressors for
an effective correction of the data.
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2092. |
Brain Tissue Specific
Spatial Distribution of fMRI Physiological Noise: CSF Noise
High or Low? ![](poster.gif)
Maryam Falahpour1,2, Hazem Refai2,
and Jerzy Bodurka1
1Laureate Institute for Brain Research,
Tulsa, Oklahoma, United States, 2Electrical
and Computer Engineering, University of Oklahoma, Tulsa,
Oklahoma, United States
It has been consistently shown that physiological noise
contribution in BOLD fMRI data is significantly greater
in gray matter than in white matter and with evidence of
the largest noise in CSF. Here, we investigate
brain-tissue-specific physiological noise spatial
distributions, along with further investigations for CSF
compartments noise level. T1-based tissue segmentation
has been used for generating appropriate masks. We
showed that the physiological noise in CSF compartments
is highly spatially dependent. It is higher for inferior
and superior axial slices where it has more overlap with
GM and brain vasculature, and lowest in the slices
containing ventricles.
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|
Traditional
Poster Session - fMRI |
|
fMRI Connectivity Analysis
Click on
to view
the abstract pdf. Click on
to view
the poster (Not all posters are available for viewing.)
Thursday 10 May 2012
Exhibition Hall |
13:30 - 15:30 |
|
|
2093. |
Independent sources of
spontaneous BOLD fluctuation along the visual pathway ![](poster.gif)
Jacco A de Zwart1, Peter van Gelderen1,
Zhongming Liu1, and Jeff H Duyn1
1Advanced MRI section, LFMI, NINDS, National
Institutes of Health, Bethesda, MD, United States
BOLD fMRI experiments of spontaneous brain activity in
humans have found inter-hemispheric correlation between
homologous regions, and suggested involvement of a
direct callosal connection. We studied spontaneous
activity in human Lateral Geniculate Nuclei (LGN), with
no direct commissural connections. High-resolution 7 T
fMRI was performed during visual stimulation and rest.
Correlation analysis was performed between left and
right LGN, and left and right visual cortex. Substantial
specific left-right LGN correlation was found, which was
not merely driven by visual cortex, or the result of
global fluctuations. Strong signal coherence was thus
found not indicative of a direct neuronal connection.
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2094. |
Power density distribution
of spontaneous BOLD fluctuations
Wen-Ju Pan1, Matthew Magnuson1,
Garth Thompson1, and Shella Keilholz1
1Biomedical Engineering, Emory
University/Georgia Institute of Technology, Atlanta, GA,
United States
The power density distribution in BOLD fluctuations of
intrinsic brain activity may be a potential index of
neural excitability. The present study examined resting
state activity in an animal model and demonstrated a
spatially-varying BOLD power distribution across brain
regions under light anesthesia. Variations were observed
across cortical areas, but much larger differences were
present between cortical and subcortical regions.
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2095. |
An objective autoselection
of resting-state networks based on time course correlation ![](poster.gif)
Hsin-Long Hsieh1,2, Pin-Yu Chen2,
Jhih-Wei He1, Yao-Chia Shih1,2,
Fu-Shan Jaw1, and Wen-Yih Isaac Tseng2
1Institute of Biomedical Engineering,
National Taiwan University, Taipei, Taiwan, Taiwan, 2Center
for Optoelectronic Biomedicine, National Taiwan
Univerity College of Medicine, Taipei, Taiwan, Taiwan
Independent component analysis (ICA) has recently been
employed in the detection of the resting-state networks
(RSNs) which are consistent and highly reproducible
across healthy subjects. However, the identification of
RSNs often involves visual inspection and/or correlating
spatial maps derived from ICA with templates or
seed-based results. To avoid bias caused by
investigators, we employed a more objective and
template-free approach to select and classify components
derived from ICA as RSNs based on the component's time
course correlation. Our proposed method adds value to
the data-driven approach in defining RSNs, and is
potentially useful in the connectome research.
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2096. |
T1/T2 Ratio Maps for the
Production of fcMRI Seed Region Based on Gray Matter
Myeloarchitecture ![](poster.gif)
Daniel L Shefchik1, Andrew S Nencka1,
Andrzej Jesmanowicz1, Edgar A DeYoe1,
and James S Hyde1
1Biophysics, Medical College of Wisconsin,
Milwaukee, WI, United States
Preliminary data show that a T1 to T2 ratio map can be
used to generate a seed region for fcMRI analysis. The
acquisition of T1 and T2 maps in the same EPI space as
fcMRI data allows a direct, one-to-one relationship
between the ratio map and the functional data for a
precise definition of the regions of interest. fcMRI
analysis based upon seeds from mCytoarchitecture removes
the need for functional scout scans from fcMRI studies,
while avoiding potential confounds associated with
template-based seed determination or independent
component analysis.
|
2097. |
A Method to Determine the
Necessity for Global Signal Regression in Resting-State fMRI
Studies
Gang Chen1, Guangyu Chen1,
Chunming Xie1, B. Douglas Ward1,
Wenjun Li1, Piero Antuono2, and
Shi-Jiang Li1
1Biophysics, Medical College of Wisconsin,
Milwaukee, WI, United States, 2Neurology,
Medical College of Wisconsin, Milwaukee, WI, United
States
In resting-state functional MRI studies, the efficacy of
the global signal regression method remains
questionable. We demonstrate that the accuracy of the
estimated global signal is determined by the level of
global noise. A method to quantify global noise levels
was then introduced. We show that a criteria to
determine the necessity for global signal regression can
be found based on the method.
|
2098. |
Effects of low pass
filtering and autocorrelation on resting state fMRI as
investigated using a regression model in SPM8 ![](poster.gif)
Kayako Matsuo1, Yung-Chin Hsu2,
and Wen-Yih I Tseng1
1National Taiwan University College of
Medicine, Taipei, Taiwan, 2Department
of Biomedical Engineering and Environmental Sciences,
National Tsing Hua University, Taipei, Taiwan
We examined an interaction between the low pass
filtering (LPF) and the first degree autocorrelation
(AR(1)) on SPM8 platform using resting state fMRI. We
set 2 different procedures for the same data: with or
without an LPF at 0.1Hz. Time courses were extracted
from 3 cognitive mode network (CMN) regions as well as 3
default mode network (DMN) regions. We set 2 different
GLMs for both of LPF and no LPF data: with or without
AR(1). The LPF and the AR(1) acted in an opposite way
with each other; specifically, the LPF enhanced DMN
activity, whereas the AR(1) decreased.
|
2099. |
Correction of hemodynamic
latency based on breath holding improves Granger causality
obtained from fMRI data ![](poster.gif)
Zhihao Li1, Behnaz Yousefi1,
Gopikrishna Deshpande2,3, and Xiaoping Hu1
1Biomedical Engineering, Emory University &
Georgia Institute of Technology, Atlanta, GA, United
States, 2Electrical
and Computer Engineering, Auburn University, Auburn, AL,
United States, 3Psychology,
Auburn University, Auburn, AL, United States
Granger causality analysis of fMRI data suffers from
spatial variability of the hemodynamic response. The
present study attempted to correct this variance by
signal latency values derived from breath holding. With
fMRI data acquired during face perception, our
correction showed improved effective connectivity from
the primary visual cortex to the fusiform face area. The
present results demonstrated the utility of breath
holding based signal latency correction for Granger
causality analysis.
|
2100. |
Grading resting-state fMRI
datasets by reweighted L1 regression ![](poster.gif)
Chia-Jung Yeh1, Yu-Sheng Tseng1,
Teng-Yi Huang1, and Shang-Yueh Tsai2,3
1Dept. of EE, National Taiwan University of
Science and Technology, Taipei, Taiwan, 2Graduate
Institute of Applied Physics, National Chengchi
University, Taipei, Taiwan,3Reasearch Center
for Mind, Brain and Learning, National Chengchi
University, Taipei, Taiwan
The rest-state fMRI (rsfMRI) detects the dynamic
neuronal activity using a long series of BOLD imaging
and measures the “connectivity” of brain functional
areas using either correlation analysis or independent
component analysis. However, in our experience, rsfMRI
sometimes shows unstable results even if we preformed
study using the same imaging protocols and data analysis
methods. In this study, we proposed to use reweighted L1
regression, a form of robust regression, to find the
“outliers” of the rsfMRI time series in the default-mode
network (DMN) and developed a grading method for rsfMRI
datasets.
|
2101. |
Resting state functional
networks VS. Structural networks: What do their differences
tell us? ![](poster.gif)
Jose Angel Pineda-Pardo1,2, Elena Molina1,
Ana Beatriz Solana1, Kenia Martinez3,
Roberto Colom3, Javier Martin Buldu4,
Juan Antonio Hernandez Tamames1, and
Francisco del Pozo Guerrero2
1Laboratory of Neuroimaging, Center for
Biomedical Technology - Universidad Politecnica de
Madrid and Universidad Rey Juan Carlos, Pozuelo de
Alarcon, Madrid, Spain,2Laboratory of
Biosignal and Brain Connectivity Analysis, Center for
Biomedical Technology - UPM, Pozuelo de Alarcon, Madrid,
Spain, 3Universidad
Autonoma de Madrid, Spain,4Laboratory of
Biological Networks, Center for Biomedical Technology -
UPM, Pozuelo de Alarcon, Madrid, Spain
In this work we present a new comparative approach
aiming to find differences between structural
connectivity and resting state functional connectivity
(SC-rsFC) networks focusing in the organization of their
connections. We compare weights distribution, normalized
graph metrics, links orientation, and Rentian scaling in
order to find out how rsFC differs from SC network.
Structural connectivity was obtained by means of a graph
based tractography method instead of usual deterministic
tractography. We found out that rsFC network was less
spatially optimized than SC in terms of Rentian scaling
and normalized graph metrics. We also observed different
tendencies in the links orientations when the weights
distributions of the networks are compared.
|
2102. |
Resolving resting state
correlations in noncompliant subjects using short TE fMRI
data ![](poster.gif)
Molly Gallogly Bright1, and Kevin Murphy1
1CUBRIC, School of Psychology, Cardiff
University, Cardiff, United Kingdom
Characterization of resting state networks may provide
insight into clinical populations. However, patients
often exhibit increased motion artifacts, obscuring
resting state correlations. Short echo time (TE) fMRI
data reflect several noise sources, and may assist in
mapping correlated networks in these scenarios. We used
a dual-echo sequence to acquire fMRI data at very short
(~3ms) and BOLD-weighted TEs. Cued head motion was
introduced to simulate noncompliant patient behavior.
The short TE data were used as voxelwise noise
regressors to correct the BOLD-weighted data. This
correction recovered seed correlation maps of the
default mode network in data with gross motion
artifacts.
|
|
|
Traditional
Poster Session - fMRI |
|
fMRI: Brain Connectivity Studies
Click on
to view
the abstract pdf. Click on
to view
the poster (Not all posters are available for viewing.)
Thursday 10 May 2012
Exhibition Hall |
13:30 - 15:30 |
|
|
2103. |
Suppression of Functional
Connectivity in Somatosensory and Attention Networks During
Strong Transcutaneous Electrical Nerve Stimulation
K Gopinath1,2, W Ringe3, L Ouyang2,
K Carter3, L Butler2, B
Thapa-Chhetry2, A Goyal2, P Gandhi2,
H Dinse4, R Haley5, and R Briggs2,5
1Department of Radiology & Imaging Sciences,
Emory University, Atlanta, GA, United States, 2Department
of Radiology, UT Southwestern Medical Center, Dallas,
TX, United States, 3Department
of Psychiatry, UT Southwestern Medical Center, Dallas,
TX, United States, 4Institut
für Neuroinformatik, Ruhr-University, Bochum, Germany,5Department
of Internal Medicine, UT Southwestern Medical Center,
Dallas, TX, United States
Resting-state functional connectivity networks are
influenced by the conditions under which fcMRI is
conducted. Previous reports have demonstrated increased
striatal functional connectivity to somatosensory and
attention networks during minimally perceptible
transcutaneous electrical stimulation (TENS-Lo),
compared to eyes open resting (REST) conditions. In this
study the functional connectivity to somatosensory and
attention networks were assessed during strongly
perceptible (but not painful) TENS (TENS-Hi), as well as
REST conditions. During TENS_Hi dorsal striatal
functional connectivity to somatosensory and attention
networks was significantly weaker compared to REST.
Combined with previous reports from TENS-Lo, results
indicate a need for systematic graded TENS fcMRI
studies.
|
2104. |
Anticorrelated
Resting-state Functional Connectivity in Awake Rat Brain
Zhifeng Liang1, Jean King1, and
Nanyin Zhang1
1Psychiatry, University of Massachusetts
Medical School, Worcester, MA, United States
Anticorrelated resting-state functional connectivity
(RSFC) has yet been observed without the commonly used
preprocessing step of global signal correction. In this
study we reported robust anticorrelated RSFC that is
independent of preprocessing procedures within a well
documented frontolimbic circuit between the infralimbic
cortex and amygdala. The finding of this study makes it
possible to uncover the neurophysiologic basis of
anticorrelated RSFC when combining with other techniques
such as neuron recording.
|
2105. |
Uncovering Intrinsic
Connectional Architecture of Functional Networks in Awake
Rat Brain
Zhifeng Liang1, Jean King1, and
Nanyin Zhang1
1Psychiatry, University of Massachusetts
Medical School, Worcester, MA, United States
Intrinsic connectional architecture of the brain is a
crucial element in understanding the governing principle
of brain organization. However, this research topic is
significantly underexplored in animals. By utilizing an
awake animal imaging model in this study we explored the
intrinsic connectional architecture of the rat brain.
Our data suggested that the rat brain network exhibited
typical features of small-worldness and strong community
structures as shown in the human brain The results of
this work provided a functional ‘atlas’ of the rat brain
at both intra- and inter-region levels. More
importantly, the current work revealed that functional
networks in rats are organized in a non-trivial manner
and conserved fundamental topological properties as the
human brain.
|
2106. |
Optical Imaging of
Functional Connectivity in the Mouse Brain
Adam Q Bauer1, Brian R White1,
Abraham Z Snyder1, Bradley L Schlaggar1,
Jin-Moo Lee2, and Joseph P Culver1
1Radiology, Washington University in Saint
Louis, Saint Louis, MO, United States, 2Neurology,
Washington University in Saint Louis, Saint Louis, MO,
United States
We combined resting-state functional connectivity
mapping with optical intrinsic signal imaging (fcOIS).
We demonstrate functional connectivity in mice through
highly detailed fcOIS mapping of resting-state networks
across most of the cerebral cortex. Synthesis of
multiple network connectivity patterns through iterative
parcellation and clustering provides a comprehensive map
of the functional neuroarchitecture and demonstrates
identification of the major functional regions of the
mouse cerebral cortex.
|
2107. |
Baseline-dependent
neurovascular coupling and its implications for
resting-state fMRI
Peter Herman1, Robert N. S. Sachdev2,
Basavaraju G. Sanganahalli1, Hal Blumenfeld2,3,
David A. McCormick2, and Fahmeed Hyder1,4
1Department of Diagnostic Radiology, Yale
University, New Haven, Connecticut, United States, 2Department
of Neurobiology, Yale University, New Haven,
Connecticut, United States, 3Department
of Neurology, Yale University, New Haven, Connecticut,
United States, 4Department
of Biomedical Engineering, Yale UNiversity, New Haven,
Connecticut, United States
A long-standing hypothesis is that tasks or stimuli that
evoke neural activity also trigger cerebral blood flow (CBF).
Here we examined whether spontaneously occurring
cortical fluctuations triggered changes in local blood
flow in head-fixed awake and anesthetized rodents. While
the linear correlations were rarely significant, using a
convolution model of neurovascular coupling we found
non-linear correlation between the neural and
hemodynamic signals. The calculated transfer functions
were significantly different in awake and anesthetized
states. In particular the intensity of neurovascular
signals decreases with deeper anesthesia and, the
response time of the neurovascular coupling slows down.
|
2108. |
Dynamics of resting-state
functional connectivity associated with heart rate
variability
Catie Chang1, Coraline D. Metzger2,
Gary H. Glover3, and Martin Walter2
1Advanced MRI section, NINDS, National
Institutes of Health, Bethesda, MD, United States, 2Department
of Psychiatry, Otto-von-Guericke University, Magdeburg,
Germany,3Department of Radiology, Stanford
University, Stanford, CA, United States
It was previously observed that functional connectivity
exhibits dynamic changes over the course of a
resting-state fMRI scan. The origins and relevance of
such fluctuations, however, are not clear. Here, we
examine whether heart rate variability, an index of
psycho-physiological state, covaries with changes in the
seed-based functional connectivity maps of regions
involved in salience processing (dACC, amygdala).
Significant effects were found in multiple cortical and
subcortical regions, including thalamus, brainstem,
basal ganglia, and insula, suggesting that fluctuations
in autonomic or emotional processes may constitute one
source of spontaneous connectivity variation.
|
2109. |
Olfactory fMRI
Connectivity Analysis Based On Granger Causality With
Application in Anosmia Assessment ![](poster.gif)
Elena Molina1, Susana Borromeo1,
Guillermo Luna1, Jose Angel Pineda-Pardo1,
Ana Beatriz Solana1, Cristina Gómez2,
Adolfo Toledano3, and Juan Antonio
Hernández-Tamames1
1Neuroimaging Lab., Center for Biomedical
Technology - Universidad Politécnica de Madrid and
Universidad Rey Juan Carlos, Pozuelo de Alarcón, Madrid,
Spain, 2CC.
Salud Universidad Rey Juan Carlos, Móstoles, Madrid,
Spain, 3Servicio
Otorrino Fundación Hospital de Alcorcón, Alcorcón,
Madrid, Spain
In this work, we describe hubs organization within the
olfactory network with Functional Magnetic Resonance
Imaging (fMRI). Granger causality analyses were applied
in preselected regions of interest (ROIs) involved in
olfactory tasks. We found differences between healthy
subjects and patients with different types of anosmia:
viral, idiopathic and traumatic. The study of the hubs
organization conducted us to an accurate description of
the strength of the nodes within the olfactory network
and which of them are impaired in different anosmic
pathologies.
|
2110.
![](MAGNA25.jpg) |
Reliable Detection of
Default Mode Network in Resting-state Perfusion fMRI using
pCASL 3D GRASE with Background Suppression ![](poster.gif)
Lirong Yan1, Yong Fan2, and Danny
JJ Wang1
1Neurology, UCLA, Los Angeles, CA, United
States, 2Institute
of Automation, Chinese Academy of Sciences, Beijing,
China
Resting-state functional connectivity (RSFC) analysis of
ASL perfusion fMRI may improve the understanding of the
biophysical mechanism of resting connectivity, and may
provide a quantitative alternative to resting state BOLD
fMRI. In this study, pseudo-continuous ASL (pCASL) with
3D background suppressed (BS) GRASE readout was used to
detect RSFC arising from spontaneous perfusion
fluctuations. By comparison with a standard
resting-state BOLD fMRI scan and a pCASL GRASE scan with
compromised BS, the present study shows that the default
mode network can be reliably detected in resting-state
perfusion image series without BOLD contamination.
|
2111. |
Prediction of Vascular
Dementia brain in distinct frequency bandwidths with
whole-brain functional connectivity patterns
Delong Zhang1, Bo Liu2,3, Jun Chen2,3,
Xiaoling Peng1, Xian Liu2,3, and
Ruiwang Huang1
1Center for Studies of Psychological
Application, Guangdong Key Laboratory of Mental Health
and Cognitive Science, South China Normal University,
Guangzhou, China,2Department of Radiology,
Guangdong Province Hospital of Traditional Chinese
Medicine, Guangzhou, China, 3Department
of Radiology, Guangzhou University of Traditional
Chinese Medicine, Guangzhou, China
Here we used support vector machines (SVM) method to
predict the Vascular Dementia (VaD), one of the most
common types of dementia, from the functional brain
scans according to the whole-brain functional networks,
and compared the detection efficiency at different
frequency bandwidths, slow-5 (0.01~0.27 Hz), slow-4
(0.027~0.073 Hz), and whole band (0.01~0.073 Hz). The
result suggested that whole-brain functional
connectivity contain adequate information about
neurobiological changes in VaD patients, and the
detection efficiency related to the slow-5 was more
prominent. These contribute to the understanding of VaD
and may facilitate discovery of biomarkers for the
diagnosis of individual VaD patient.
|
2112. |
The brain default mode
network in patients with type 1 diabetes and hypoglycemia
unawareness under different blood glucose levels
Silvia Mangia1, Federico De Martino1,2,
Anjali Kumar3, Amir Moheet3, Pete
Kollasch1, Lynn Eberly4, and
Elizabeth Seaquist3
1CMRR - Dept. of Radiology, University of
Minnesota, Minneapolis, Minnesota, United States, 2Department
of Cognitive Neuroscience, University of Maastricht,
Maastricht, Netherlands, 3Dept.
of Medicine, University of Minnesota, Minneapolis,
Minnesota, United States, 4Div.
of Biostatistics, University of Minnesota, Minneapolis,
Minnesota, United States
We measured the brain default mode network (DMN) in six
subjects with type 1 diabetes (T1DM) and hypoglycemia
unawareness and in seven healthy controls with similar
age and body-mass-index, by using resting-state fMRI
while blood glucose levels were controlled by
hyperinsulinemic clamps. Decreased functional
connectivity of some DMN regions was observed in T1DM
subjects as compared to controls in euglycemia.
Furthermore, whereas the prefrontal cortex had basically
no functional connectivity to the other areas of the DMN
during hypoglycemia in controls, such response was
largely reduced in T1DM unaware patients, likely
reflecting differences their perception of the stress of
hypoglycemia.
|
2113. |
A resting-state fMRI study
in chronic obstruction pulmonary disease
Ai Wern Chung1, James W. Dodd2,
Rebecca A. Charlton3, Paul W. Jones2,
and Thomas R. Barrick1
1Stroke and Dementia Research Centre, St
George's University of London, London, London, United
Kingdom, 2Division
of Clinical Science, St George's University of London,
London, United Kingdom, 3Department
of Psychiatry, University of Illinois at Chicago,
Chicago, IL, United States
Chronic obstructive pulmonary disease (COPD) is a
heterogeneous condition increasingly recognised to be a
multi-system disorder associated with a wide range of
extra pulmonary comorbidities such as heart disease.
Brain pathology and cognitive dysfunction is a potential
systemic occurrence in COPD. Using functional MRI, we
sought to identify differences in the underlying
functional connectivity between stable COPD patients and
controls, under the resting-state condition. We found
wide-spread decrease in resting-state functional
connectivity across the brain including the default mode
and pre-frontal networks, suggesting global differences
between patients and controls.
|
2114. |
Altered Baseline
Oxygenation and Blood Flow Perturb Resting-state Functional
Connectivity – a Nonhuman Primate Study
Hsiao-Ying Wey1,2, Jinqi Li2, and
Timothy Q Duong2,3
1Department of Radiology, A. A. Martinos
Center for Biomedical Imaging, MGH/Harvard Medical
School, Charlestown, MA, United States, 2Research
Imaging Institute, University of Texas Health Science
Center at San Antonio, San Antonio, TX, United States, 3Department
of Radiology, University of Texas Health Science Center
at San Antonio, San Antonio, TX, United States
Recent advances in resting-state functional connectivity
highlight its potential utility in clinical populations.
In this study, we aimed to systematically investigate
the effects of different basal oxygenation and blood
flow conditions on fc measurements in non-human primate.
Our results showed that cerebral connectivity, when
compared to normal air condition, was reduced under
hypercapnia and hyperoxia but remained comparable under
hypoxia. These findings could have strong implications
when applying resting-state fMRI in disease states in
which baseline oxygenation and blood flow are markedly
altered.
|
2115. |
Differential Resting-State
Network Connectivity of Extrastriate Body Area and Lateral
Occipital Complex
Kaundinya Gopinath1,2, Aman Goyal2,
Richard Briggs2, and K Sathian3
1Department of Radiology & Imaging Sciences,
Emory University, Atlanta, GA, United States, 2Department
of Radiology, UT Southwestern Medical Center, Dallas,
TX, United States, 3Department
of Neurology, Emory University, Atlanta, GA, United
States
A number of areas in the human occipitotemporal cortex
are specialized for processing particular types of
sensory stimuli. Among these areas are the lateral
occipital complex (LOC), an object-selective area and
the extrastriate body area (EBA), a body part-selective
area. This study used seed-based and graph theory
approaches to test whether these areas connect to
distinct resting-state networks. LOC and EBA exhibited
different functional connectivity patterns. LOC
interacted more with motor regions and lateral
frontoparietal regions involved in processing external
stimuli. In contrast EBA interacted more with somatic
sensorimotor regions and DMN regions involved in
self-referential processing.
|
2116. |
Differential effect of
medetomidine on functional activation and connectivity:
electrophysiology validation ![](poster.gif)
Si Kang Lew1, Fatima Nasrallah1,
Amanda Low1, and Kai Hsiang Chuang1
1MRI Group, Singapore Bioimaging Consortium,
Singapore, Singapore, Singapore
Previous study on medetomidine showed dosage dependent
suppression of functional connectivity without changing
BOLD activation. We used electrophysiology measurements
including somatosensory evoked potential (SEP) and
resting electroencephalography (EEG) to understand the
underlying neural correlate. The neurovascular coupling
was investigated in the primary somatosensory cortex
(S1) using forepaw stimulation. The SEP shows similar
response under different medetomidine doses and
correlated well with BOLD activation. The coherence of
resting EEG between the bilateral S1 didn’t change
except for gamma band. The link between BOLD fluctuation
and EEG synchrony has yet to be determined.
|
2117. |
Adrenergic receptor
agonist vs antagonist tuning functional connectivity in
resting state ![](poster.gif)
Fatima Ali Nasrallah1, Amanda Simin1,
Chen Kaina1, and Kai-Hsiang Chuang1
1MRI Group, Singapore Bioimaging Consortium,
Singapore, Singapore, Singapore
Receptor targeted pharmaceuticals are applied to
modulate neurotransmission to investigate the neural
correlate of resting state functional connectivity. The
á2 adrenergic receptor agonist, Medetomidine, and
antagonist, Atipamezole, were used to understand the
role of the adrenergic system in modulating functional
connectivity. Activation of the á2 receptor caused a
dosage dependant loss of interhemispheric connectivity
compared to deactivation of the receptor by the
antagonist which resulted in an increase in functional
connectivity. This study provides an insight into the
underlying basis of functional connectivity.
|
2118. |
Anterior-Posterior
Dissociation of the Default Mode Network in Dogs
Sreenath Pruthviraj Kyathanahally1, Oleg
Mykolajovych Pustovyy2, Paul Waggoner3,
Ronald Beyers1, John Schumacher4,
Jay Barrett5, Edward E Morrison2,
Robert L Gillette4, Thomas S Denney1,6,
Vitaly J Vodyanoy5, and Gopikrishna Deshpande1,6
1AU MRI Research center,Department of
Electrical and Computer Engineering, Auburn University,
Auburn, Alabama, United States, 2Department
of Anatomy,Physiology & Pharmacology, Auburn University,
Auburn, Alabama, United States, 3Canine
Detection Research Institute, Auburn University, Auburn,
Alabama, United States, 4Department
of Clinical Sciences, Auburn University, Auburn,
Alabama, United States, 5College
of Veterinary Medicine, Auburn University, Auburn,
Alabama, United States, 6Department
of Psychology, Auburn University, Auburn, Alabama,
United States
The Default mode network (DMN) has been observed in
humans and monkeys, but not in rodents. In order to
investigate the evolutionary hierarchy of the DMN, we
obtained resting state fMRI data in dogs and performed
independent component analysis (ICA). Dogs, being lower
than humans/monkeys, but higher than rodents in
evolution, showed localized correlations in the
posterior cingulate region in one ICA component while in
the medial frontal regions in another ICA component.
This shows that there is anterior-posterior dissociation
and localized synchrony in DMN in dogs, which is a
strikingly similar result to the one obtained in young
children.
|
2119. |
Finding thalamic BOLD
correlates to cortical alpha modulation
Zhongming Liu1, Jacco A de Zwart1,
Bing Yao1, Peter van Gelderen1,
Li-Wei Kuo1, and Jeff H Duyn1
1Advanced MRI Section, LFMI, NINDS, National
Institutes of Health, Bethesda, Maryland, United States
Simultaneous EEG-fMRI data were analyzed to reveal the
thalamocortical networks associated with the modulation
of cortical alpha (8-12Hz) EEG. The occipital alpha
rhythm was found to be negatively correlated with the
BOLD signals at both the visual cortex and the visual
thalamus but positively at the anterior dorsal nuclei,
which was neither structurally nor functionally
connected with the visual cortex. Negative thalamic
BOLD-alpha correlation was mostly found at Pulvinar, as
confirmed by comparison with reference locations defined
through functional localizer with visual stimulation as
well as high-resolution anatomical images with gradient
echo phase contrast at 7T.
|
2120. |
The “foot-print” of memory
encoding on the brain
Deng Mao1, Kuang-Chi Tung1,
Peiying Liu1, Yong He2, Jinhui
Wang2, and Hanzhang Lu1
1Advanced Imaging Research Center, University
of Texas Southwestern Medical Center, Dallas, Texas,
United States, 2State
Key Laboratory of Cognitive Neuroscience and Learning,
Beijing Normal University, Beijing, China
A number of evidences have suggested that the resting
brain can be modulated by recent experience. However,
few reports have demonstrated the feasibility to measure
brain changes after merely minutes of use. Here, we used
a 20-min memory encoding task to stimulate the brain,
and collected fcMRI data (under resting state) before
and after the task. We compared resting brain networks
between these two time points and demonstrated that
fcMRI brain networks can be modified in the acute phase
using a memory task. Finally, we correlated the extent
of connectivity change with the behavioral data of
memory scores across individuals.
|
2121. |
Modulation of hypothalamic
connectivity by food ingestion
Claudia Huerta1, Jinqi Li1,
Hsiao-Ying Wey2, and Timothy Q Duong1
1UTHSCSA, San Antonio, TX, United States, 2Martinos
Center for Biomedical Imaging, Charlestown,
Massachussetts, United States
The hypothalamus plays a pivot role in the regulation of
satiety and hunger. This study optimized imaging
parameters to ensure reliable detection and stability of
EPI signals from the hypothalamic and applied rsfMRI to
identify hypothalamic network regulating hunger and
satiety in healthy lean subjects. We identified common
and different activated structures before and after food
ingestion, some are established and some appeared novel.
Future studies will focus on validation, extend this
approach to study hypothalamic connectivity in obese
subjects to attempt to undercover pathological neural
mechanisms regulating satiety.
|
2122. |
Resting-State Functional
Connectivity during Pregnancy ![](poster.gif)
Russell Wade Chan1,2, Iris Y. Zhou1,2,
Leon C. Ho1,2, and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal
Processing, The University of Hong Kong, Hong Kong SAR,
China, 2Electrical
and Electronic Engineering, The University of Hong Kong,
Hong Kong SAR, China
This study explores the effects of pregnancy on
resting-state functional connectivity in the rat brain.
The results show that pregnancy alters the strength and
spatial distribution of the fcMRI signals. Specifically,
the effects of pregnancy at G17 increase the spontaneous
fluctuations in fcMRI signal in the caudate putamen,
hippocampus and thalamus; whereas the spontaneous
fluctuations in fcMRI signal were similar in the motor
cortex for the pregnant and non-pregnant group. The
longitudinal effects of pregnancy, as well as, the
effects on other functional networks are to be explored.
|
2123. |
Brain Networks Modulated
by Menstrual Cycle: a Resting State Study ![](poster.gif)
Xinyuan Miao1, Thomas Zeffiro2,
Jing Chen1, Xiaohong Joe Zhou3,
and Yan Zhuo1
1Institute of Biophysics, Chinese Academy of
Sciences, Beijing, Beijing, China, 2Neural
Systems Group, Massachusetts General Hospital, 3Department
of Radiology and Center for MR Research, University of
Illinois Medical Center, United States
n this resting state study, we examined the effect of
the menstrual cycle on six major functional brain
networks as well as the hippocampus and amygdala,
regions which may play an important role in spatial
cognition and emotion processing throughout the
menstrual cycle. We utilized 160 meta-analysis derived
ROIs to parcellate the cortex and cerebellum into six
networks: cingulo-opercular, frontoparietal, default
mode, sensorimotor, occipital, and cerebellar. It was
observed that the inter-regional correlations among some
of these networks as well as the hippocampus and
amygdala were differentially modulated during phases of
the menstrual cycle.
|
2124. |
Prior cognitive state can
influence functional connectivity networks at the individual
and group level. ![](poster.gif)
Chris Tailby1,2, David F Abbott1,3,
and Graeme D Jackson1,3
1Brain Research Institute, Florey
Neuroscience Institutes, Melbourne, Victoria, Australia, 2Psychological
Sciences, University of Melbourne, Melbourne, Victoria,
Australia,3Department of Medicine, University
of Melbourne, Melbourne, Victoria, Australia
Previous work demonstrated that resting state functional
connectivity (RSFC) measured in an individual can vary
with prior cognitive state. The analysis of large
multicentre data sets using RSFC is becoming
increasingly widespread. It is therefore important to
determine whether the dependence of RSFC on a given
prior cognitive state is consistent across individuals,
as this would have the potential to bias large
multicentre RSFC analyses. By comparing, across 25
healthy participants, RSFC maps obtained following
performance of two cognitive tasks we show that RSFC
networks vary heterogeneously across subjects. Such
effects can produce weak effects at the group level.
|
2125. |
Seed-based functional
connectivity analysis of the emotional circuitry: Improving
the signal of vulnerable regions with spin-echo EPI
Roberto Goya-Maldonado1, Brice Fernandez1,2,
Victor Spoormaker1, and Michael Czisch1
1MPI of Psychiatry, Munich, BY, Germany, 2GE
Healthcare, Global Applied Science Laboratory, Munich,
Germany
Functional connectivity (fc) analysis allows monitoring
specific regional brain changes in activation along
time. The susceptibility artifacts commonly present
during the acquisition of fMRI with GRE-EPI can
drastically limit the investigation of the emotional
circuitry. We tested the applicability of SE-EPI for fc
analysis at 3T. The seeds placed in the emotional
circuitry presented robust and anatomically reliable
connectivity patterns in the differential contrast
SE>GRE. This suggests a potential benefit to be further
explored in functional studies addressing the affective
system.
|
2126. |
Investigation of the
large-scale functional brain networks modulated by long-time
transcutaneous electric acupoint stimulation ![](poster.gif)
Yin Jiang1, Yue Zhang2, Jing Wang2,
Jing Fang2, Jisheng Han1, Xiaoping
Hu3, Cailian Cui1, and Jue Zhang2
1Neuroscience Research Institute and
Department of Neurobiology, Peking University, beijing,
China, 2Biomedical
Engineering, Peking University, beijing, China, 3Biomedical
Engineering, Georgia Institute of Technology and Emory
University, Atlanta, Georgia, United States
Acupuncture has been worldwide used to against many
disorders. However, the neural mechanism underlying
acupuncture is still unclear. Many studies have
investigated to the sustained effects using short-time
acupuncture (no more than 6 min) for healthy subjects,
which may be not long enough to satisfy the treatment
effects. This is the first study, to our knowledge, to
investigate small-world properties of brain functional
networks modulated by long-time acupuncture(30 minutes).
A tendency of increasing local efficiency was
demonstrated in TEAS(transcutaneous electric acupoint
stimulation) when compared with MTEAS(minimal
TEAS),which suggest higher fault-tolerance for brain
network after long-time acupuncture.
|
2127.
![](MAGNA25.jpg) |
Resting-state functional
connectivity predicts the amplitude of the BOLD response to
thermal pain stimulation in humans
Stephen D Mayhew1, Nicholas Hylands-White2,
Camillo Porcaro3, and Andrew P Bagshaw1
1Birmingham University Imaging Centre, School
of Psychology, University of Birmingham, Birmingham,
West Mids, United Kingdom, 2Pain
Management Group, Faculty of Health, Birmingham City
University, Birmingham, United Kingdom, 3Institute
of Neuroscience, Newcastle University, Newcastle upon
Tyne, United Kingdom
Here we define pain regions of interest (ROIs) from
brain areas exhibiting a very significant BOLD response
to thermal stimulation: ACC, SII and anterior insula. We
compare the strength of functional connectivity between
these ROIs during rest with the mean amplitude of the
BOLD response in these ROIs during the stimulation runs.
We observed that subjects who had greater resting
connectivity between pain-responsive regions had a
larger BOLD response to thermal pain stimulation. This
work provides a novel demonstration that part of the
inter-subject variability in evoked BOLD responses is
explained by the intrinsic resting properties of the
pain network.
|
2128. |
Graph theoretical Network
Analysis of Pain Processing: Pain is more than Sensation
Silke Kreitz1, Marina Sergejeva1,
and Andreas Hess1
1Institute of Experimental and Clinical
Pharmacology and Toxicology, FAU Erlangen-Nuremberg,
Erlangen, Germany
The investigation of the neural basis of pain perception
using modern neuroimaging techniques, such as functional
MRI, has shown that nociceptive stimuli commonly elicit
activity within a wide range of brain structures. In
this study, we used functional MRI and graph theoretical
network analysis methods to investigate the connectivity
between mouse brain structures that are activated by
thermal nociceptive and non nociceptive stimuli. The
resulting stimulus specific interregional connectivity
networks demonstrate the rebuilding of connections
between brain structures during nocicpetive processing
and give us a deeper insight into the functionality of
the brain under pain.
|
|
|
Traditional
Poster Session - fMRI |
|
fMRI: Cognitive Neuroscience
Click on
to view
the abstract pdf. Click on
to view
the poster (Not all posters are available for viewing.)
Thursday 10 May 20122
Exhibition Hall |
13:30 - 15:30 |
|
|
2129. |
Load Dependency of
Correlation between Intrinsic Brain Activity and Brain
Activation Induced by Working Memory Task
Qihong Zou1,2, Thomas J. Ross2,
Hong Gu2, Xiujuan Geng2, Xi-Nian
Zuo3, Elliot L. Hong4, Jia-Hong
Gao1,5, Elliot A. Stein2, Yu-Feng
Zang6,7, and Yihong Yang2
1MRI Research Center and Beijing City Key Lab
for Medical Physics and Engineering, Peking University,
Beijing, Beijing, China, 2Neuroimaging
Research Branch, National Institute on Drug Abuse,
National Institutes of Health, Baltimore, MD, United
States, 3Institute
of Psychology, Chinese Academy of Sciences, Beijing,
Beijing, China, 4Maryland
Psychiatric Research Center, Department of Psychiatry,
University of Maryland School of Medicine, Baltimore,
MD, United States, 5Brain
Research Imaging Center, University of Chicago, Chicago,
IL, United States, 6Center
for Cognition and Brain Disorders and The Affiliated
Hospital, Hangzhou Normal University, Hangzhou,
Zhejiang, China, 7State
Key Laboratory of Cognitive Neuroscience and Learning,
Beijing Normal University, Beijing, Beijing
There is no consensus whether spontaneous activity
predicts task activation, and it is unknown whether
rest-task relationship is dependent on task load. Here,
we investigate these issues on forty subjects with a
resting-state scan and following N-back verbal working
memory task scans. We show that fALFF during resting
state can predict activation during working memory task.
We further demonstrate that such rest-task correlations
are modulated by cognitive load of working memory task.
These findings suggest that resting-state activity
facilitate specific brain circuit engagement for
performing a cognitive task, and that resting-state
activity can load dependently predict task-induced brain
responses.
|
2130. |
Quantification of Load
Dependent Brain Activity in Parametric N-Back Working Memory
Tasks using pCASL Perfusion Imaging
Qihong Zou1,2, Hong Gu2,
Jiongjiong Wang3, Jia-Hong Gao1,4,
and Yihong Yang2
1MRI Research Center and Beijing City Key Lab
for Medical Physics and Engineering, Peking University,
Beijing, Beijing, China, 2Neuroimaging
Research Branch, National Institute on Drug Abuse,
National Institutes of Health, Baltimore, MD, United
States, 3Department
of Neurology, University of California Los Angeles, Los
Angeles, CA, United States, 4Brain
Research Imaging Center, University of Chicago, Chicago,
IL, United States
Brain activation and deactivation induced by N-back
working memory tasks and load effects have been
investigated using PET and BOLD fMRI. However,
mechanisms of BOLD fMRI are not completely understood
and PET requires injection of radioactive tracers. Here,
a pCASL technique was used to quantify CBF, a well
understood index reflective of cerebral metabolism. We
showed activation in fronto-parietal cortices and
deactivation in PCC and MPFC during working memory
tasks. Most of the activated/deactivated brain regions
showed approximately linear relationship between CBF and
task loads. These results demonstrate feasibility of ASL
techniques to quantify brain activity during high
cognitive tasks.
|
2131. |
Differential neural
activation in field dependent and field independent subjects
for a camouflage detection task: An fMRI study
Shilpi Modi1, Janani Rajagopalan2,
Pawan Kumar1, Rajendra P Tripathi1,
Subash Khushu1, and Manas K Mandal2
1Institute of Nuclear Medicine and Allied
Sciences (INMAS), Delhi, Delhi, India, 2Defence
Institute of Psychological Research, Delhi, Delhi, India
An fMRI paradigm was designed to obtain the neural
correlates of camouflage detection with real life
photographs. The study accentuates on the comparative
study between Field-dependent and Field-independent
individuals in accordance to their neural correlates
derived upon camouflage detection. A widespread
activation of the dorsal stream of visual processing was
obtained with a greater activation in field dependent
subjects as compared to the field independent ones
suggesting a greater effort required by them for task
performance. However, additional recruitment of superior
parietal, thalamic and cerebellar regions in field
independent subjects might explain their capability to
better perform the task.
|
2132. |
Greater activation of
brain regions serving abstract reasoning abilities in
alcohol dependents: An fMRI study
Deepika Bagga1, Namita Singh1,
Shilpi Modi1, Mohan Lal Garg2,
Debajyoti Bhattacharyya3, Prabhjot Kaur1,
and Subash Khushu1
1NMR Research Centre, Institute of Nuclear
Medicine and Allied Sciences (INMAS), Delhi, Delhi,
India, 2Department
of Biophysics, Punjab University, Chandigarh, Punjab,
India,3Base Hospital, Army Medical Corps,
Delhi, Delhi, India
Neuropsychological findings suggest a deficit in
abstract reasoning abilities in alcohol dependents.
However, this deficit has not been studied so far using
BOLD fMRI. We attempted to address this issue by
carrying out an fMRI study on alcohol dependents and
controls for an abstract reasoning task. Alcoholics
showed a greater activation in the
fronto-parieto-temporal network implicated in abstract
reasoning suggesting a compensatory mechanism to meet
the task performance comparable to controls.
|
2133. |
Neural plasticity of Brain
Motor Networks in Professional Fencers Studied with
Functional MRI ![](poster.gif)
Laura Parisi1, Maria A. Rocca1,
Letizia Leocani2, Roberto Gatti3,
Carlotta Castellani2, Monica Rossi3,
Andrea Falini4, Giancarlo Comi5,
and Massimo Filippi1
1Neuroimaging Research Unit, Institute of
Experimental Neurology, San Raffaele Scientific
Institute and Vita-Salute San Raffaele University,
Milan, Italy, Italy, 2Dept.
of Clinical Neurophysiology, San Raffaele Scientific
Institute and Vita-Salute San Raffaele University,
Milan, Italy, Italy, 3Rehabilitation
Department, San Raffaele Scientific Institute and
Vita-Salute San Raffaele University, Milan, Italy,
Italy, 4Department
of Neuroradiology, San Raffaele Scientific Institute and
Vita-Salute San Raffaele University, Milan, Italy,
Italy, 5Department
of Neurology, San Raffaele Scientific Institute and
Vita-Salute San Raffaele University, Milan, Italy, Italy
Using functional magnetic resonance imaging (fMRI), we
investigated brain motor networks involved in interlimb
coordination in 14 young high-level professional fencers
in comparison to 15 matched young, untrained subjects
while performing three different motor tasks (bimanual
anti-phase, right hand-foot in-phase and right hand-foot
anti-phase movements). Both single motor task analysis
and voxel-wise analysis of functional connectivity with
the motor cortex showed an optimization of the
recruitment of the brain regions underlying interlimb
coordination in fencers in comparison to controls,
suggesting that specific intensive motor training can
modulate neural plasticity of cerebro-cerebellar-basal
ganglia loops and their functional connectivities.
|
2134. |
The Study of Deception and
Truth Using Functional Magnetic Resonance Imaging (fMRI) ![](poster.gif)
Ajchamon Thammachai1, Suwit Saekho2,3,
Nuanlaor Thawinchai4, Taipesrinivasti
Bhakdikul5, Uten Yarach2, Sranut
Chunpenmongkol2, and Witaya Sungkarat6
1program in Forensic Science, Graduate
school, Chiang Mai University, Chiang Mai, 50200,
Thailand, 2Radiological
Technology, Faculty of Associated Medical Sciences,
Chiang Mai University, Thailand, 3Biomedical
Engineering Center, Chiang Mai University, Thailand, 4Physical
Therapy, Faculty of Associated Medical Sciences, Chiang
Mai University, Thailand, 5Faculty
of Law, Chiang Mai University, Thailand, 6Radiology,
Mahidol University, Thailand
Deceptive detection using Functional magnetic resonance
imaging (fMRI) is an exciting tool. The Peak of Tension
Test (POT) can provoke deceptions about criminal
details. We propose a new method to identify deception
using the POT along with the fMRI by comparing the
differences in brain activities between deception and
truth telling in both POT and Relevant questions (R).
The results demonstrated that right inferior frontal
gyrus was more activated in the POT. Left inferior and
middle frontal gyri were more activated during deception
than those telling the truth.
|
2135. |
Persistent activity in
posterior parietal cortex reflects planned changes in
orientation during navigation ![](poster.gif)
Peter Brotchie1,2, Shaun Seixas3,
Shoane Ip4, Mathew Hughes3, and
Graeme Jackson4
1MRI, Geelong Hospital, Geelong, Victoria,
Australia, 2Radiology,
University of Melbourne, Melbourne, Victoria, Australia, 3Brain
and Psychological Research Centre, Swinburne University
of Technology, Melbourne, Victoria, Australia, 4Melbourne
Brain Centre, Brain Research Institute, Melbourne,
Victoria, Australia
Posterior parietal cortex (PPC) has long been known to
be involved in spatial processing, forming a key element
of the “where” pathway in visual processing. However,
its role in navigation has not been well documented with
functional imaging studies. In this study we have looked
at the role of PPC in navigation using a delayed
response paradigm to assess the persistent activity that
is known to be present in the neurons of the posterior
parietal cortex (PPC) in delayed response tasks. In
order to detect orientation specific activity, we used
repetition suppression of the subect’s orientation with
respect to a virtual environment. We found increased
activity predominantly in area PFm of the left PPC that
was orientation specific, but present only when the
subject was planning a change in orientation. The
findings indicate a specialised region in PPC that plans
for upcoming changes in orientation.
|
2136. |
Bittersweet - neither
happy nor sad. An experimental comparision of the neural
effects of bittersweet, negative and positive film clips
using 7T fMRI
Frank P. Schulte1,2, Stefan Maderwald2,
Nicole C. Kraemer3, and Matthias Brand1,2
1General Psychology: Cognition, University
Duisburg-Essen, Duisburg, Germany, 2Erwin
L. Hahn Institute for Magnetic Resonance Imaging,
University Duisburg-Essen, Essen, Germany, 3Social
Psychology: Media and Communication, University
Duisburg-Essen, Duisburg, Germany
Media psychology suggests that watching sad movies does
not only include sad aspects, but also positive
messages, and elicits “bittersweet” feelings. Using
7T-fMRI, we examined neural activity during the
presentation of positive, negative and bittersweet
movies. Data from 10 female participants shows
activation differences in the left orbitofrontal cortex
(BA 47,11), indicating that this region is crucially
involved in integrating the sweet and the bitter
component of bittersweet movies. We found no activation
differences within key brain structures of the limbic
system, indicating that the different presented films
seem to have induced equally strong emotional
experiences.
|
2137. |
Convergence of emotion
processing on the right ventrolateral prefrontal cortex:
Parametric mediation analysis of fMRI ![](poster.gif)
Ikuhiro Kida1, Yoshinobu Iguchi1,
and Yoko Hoshi1
1Tokyo Metropolitan Institute of Medical
Science, Setagaya-ku, Tokyo, Japan
We employed parametric mediation analysis to identify
the functional circuits mediating emotion response.
Unpleasant pictures induced activity in sub-cortical
regions, including the amygdala, as well as in cortical
regions, particularly the right inferior frontal gyrus.
Parametric mediation analysis of fMRI signals in the
activated region revealed that, although the right
ventrolateral prefrontal cortex (VLPFC), BA47, contained
no mediators for valence, the region was a mediator for
all other predictors. These results suggest that the
right VLPFC plays a key role in emotion generation and
cognition through the convergence of emotion processing
on this region from other cortical and sub-cortical
regions.
|
2138. |
Differential Consolidation
of Motor Memory
Kuang-Chi Tung1, Jinsoo Uh1, and
Hanzhang Lu1
1Advanced Imaging Research Center, University
of Texas Southwestern Medical Center, Dallas, TX, United
States
Resting brain encodes footprint of training effect. The
spatial pattern of increase in the amount of spontaneous
activity and functional connectivity are strikingly
different, based on the amount of neural activity
involved during the training. Our present findings show
that in two-hand training, consolidation of training
effect took place in frontal lobe and mid-brain regions
such as hypothalamus and basal nuclei, whereas in
one-hand training, it took place primarily in the motor
and somatosensory areas.
|
2139. |
Investigation of
recognition memory in fMRI using optimal stimulus
arrangement with behavioral information from pilot studies ![](poster.gif)
Dietmar Cordes1, Grit Herzmann2,
Rajesh Nandy3, and Tim Curran2
1University of Colorado, Denver, CO, United
States, 2University
of Colorado, Boulder, CO, United States, 3University
of California, Los Angeles, CA, United States
In this study, a new method is proposed for optimization
of contrast detection power by including probabilistic
behavioral information, based on pilot data, in the
genetic algorithm. As a particular application, a
recognition memory task is studied and the design matrix
optimized for contrasts involving the familiarity of
individual items and the recollection of the items'
qualitative information. Optimization of contrast
efficiency is a complicated issue, especially for
recognition memory tasks, because subjects’ responses
are not deterministic but probabilistic. Contrast
efficiencies are not predictable unless behavioral
responses are included in the design optimization.
|
2140. |
Brain control performance
using single- and dual-ROI’s in real-time fMRI with
neurofeedback
Jason G Parker1,2, Jonathan Sackett3,
Phani Kidambi2, Lacey Sickinger1,
and Cemil Kirbas1,4
1Innovation Center, Kettering Health Network,
Kettering, OH - Ohio, United States, 2Biomedical,
Industrial, and Human Factors Engineering, Wright State
University, Dayton, OH - Ohio, United States, 3Siemens
Medical Solutions USA, Malvern, PA, United States, 4Psychiatry,
Wright State University, Dayton, OH - Ohio, United
States
The magnitude and extent by which humans can control
brain function remains poorly understood. The purpose of
this work was to determine if humans receiving
neurofeedback on two brain regions simultaneously were
less effective at learning brain control than those
receiving feedback from a single region. Ten subjects (2
groups of 5) were imaged during single- and dual-ROI
feedback. Performance was quantified as the mean %
signal changed weighted by the HRF. No significant
differences were found between the two methods, possibly
indicating humans can learn to control multiple brain
regions at once.
|
2141. |
The Dependency of
Correlation between the BOLD Based Aging Index and MMSE
Score on the Cognitive Contents
Toshiharu Nakai1, Naoki Kamiya1,
Makoto Miyakoshi2, and Kayako Matsuo3
1Neuroimaging & Informatics, NCGG, Ohbu,
Aichi, Japan, 2JSPS,
Tokyo, Japan, 3NTU,
Taipei, Taiwan
The correlation between the BOLD based aging index (BAI)
and MMSE score change two years later was evaluated. It
was indicated that age-related augmentation of brain
activation observed in early stage of the elderly group
(60-75 year old) may be associated with the potential
risk of converting to MCI, when BAI was evaluated using
a visuo-motor task, while BAI obtained by checker board
stimuli did not correlate with MMSE score change. BAI
may represent two different types of demand at
neuro-physiological and neuronal circuit level, which
can be discriminated by the cognitive contents of the
tasks.
|
2142. |
Multimodal food
perception: meta-analysis of neuroimaging studies of food
cues ![](poster.gif)
Claudia Huerta1, and Timothy Q Duong1
1UTHSCSA, San Antonio, TX, United States
The aim of the present study was to determine the
concurrence in the brain regions activated in response
to multimodal food cue stimuli in healthy normal weight
adults. Activation likelihood estimation meta-analysis
was performed for: i) visual food cues, contrasted
between food and nonfood pictures, ii) taste food cues,
contrasted between food and tasteless solution, and iii)
olfactory food cues contrasted between food/pleasant and
nonfood/unpleasant odors. Different neural systems were
observed to be associated with each modality but the
insula was commonly engaged across the different
presentations of food cues.we have identified and
compared the neural systems involved in different food
cue presentations in healthy normal weight adults. These
findings have the potential to improve our understanding
of food perception, advance research in neurophysiology
and neuropathology of hunger and craving, and help
develop novel therapeutic strategies targeting obesity.
|
2143. |
Covariate effects in
verbal working memory fMRI using schizophrenia and control
participants ![](poster.gif)
Kayako Matsuo1, S.H. Annabel Chen2,
Chih-Min Liu3, Chen-Chung Liu3,
Hai-Go Hwu3, and Wen-Yih I Tseng1
1National Taiwan University College of
Medicine, Taipei, Taiwan, 2Division
of Psychology, Nanyang Technological University,
Singapore, 3Department
of Psychiatry, National Taiwan University Hospital,
Taipei, Taiwan
We investigated influences of various covariates on a
verbal working memory (VWM) fMRI employing 18 each of
schizophrenia and control participants. Six covariates
of age, gender, response time (RT), accuracy rate,
handedness score, and education year had all no
significant differences between the two subject groups.
Covariates by the behavioral data (RT and accuracy)
specifically showed positive correlations with the DMN
activation, which reflect the self-regulating mechanism
during the low load condition. The inclusion of
covariates into the design matrix was effective to
obtain the “true†contrast effects even when the
comparison groups were “matched†beforehand.
|
2144. |
Functional MRI study of
visual processing of affirmative and negative sentences
Uttam Kumar1, and C L Khetrapal1
1CBMR, Center of Biomedical Magnetic
Resonance, Lucknow, Uttar Pradesh, India
Functional Magnetic Resonance Imaging technique has been
employed to study the expression and interpretation of
negation in Hindi language. Hindi is subject-object-verb
(SOV) language and has a long tradition of grammar and
literature. To account the effect of semantic and
syntactic features on neural network the study was
undertaken where native Hindi reader performed the
sentence judgment task (target-Probe) in affirmative and
negative sentences. The result shows involvement of
common as well as distinct regions for affirmative and
negative sentences.
|
2145. |
fMRI Neurofeedback of
Kinesthetic Motor Imagery ![](poster.gif)
Mark Chiew1,2, Stephen M LaConte3,4,
and Simon J Graham1,5
1Medical Biophysics, University of Toronto,
Toronto, Ontario, Canada, 2Rotman
Research Institute, Toronto, Ontario, Canada, 3Virginia
Tech Carilion Research Institute, Virginia Tech,
Roanoke, Virginia, United States, 4Virginia
Tech – Wake Forest University School of Biomedical
Engineering and Sciences, Virginia Tech, Blacksburg,
Virginia, United States, 5Imaging
Research, Sunnybrook Research Institute, Toronto,
Ontario, Canada
Functional MRI neurofeedback (fMRI NF) enables subjects
to regulate their brain activity by viewing and
manipulating their fMRI signals in real-time. Here we
present an fMRI NF study of brain activity in the left
and right primary motor (M1) ROIs associated with
kinesthetic motor imagery, analyzed offline using
partial least squares methods. Using a differential
feedback measure (left M1 - right M1 and vice versa), we
found subjects were more successful at suppressing
activity in the ipsilateral M1 than up-regulating
activity in the contralateral M1, and that task success
was correlated with expression of task-positive network
regions.
|
2146. |
Investigating the duration
of brain response to acupuncture stimulation by using
independent component analysis ![](poster.gif)
Tomokazu Murase1, Masahiro Umeda2,
Yuko Kawai2, Yasuharu Watanabe2,
Toshihiro Higuchi3, and Chuzo Tanaka3
1Department of Neurosurgery, Meiji University
of integrative Medicine, Nantan-shi, Kyoto, Japan, 2Department
of informatics, Meiji University of integrative
Medicine,3Department of Neurosurgery, Meiji
University of integrative Medicine
We examined the correlation between the selected ICs and
some hypothetical GLMs and predicted the temporal delay
in brain activation induced by acupuncture. The fMRI
data were analyzed using Tensor-ICA, and IC-related
cerebral activity with each stimulation was selected to
the activation area by referring to previous studies.
Acupuncture stimulation for a duration of 15 s resulted
in little cerebral activity; however, a duration of 30 s
resulted in great cerebral activity in the predictable
area. In conclusion, we found that changes in BOLD
signals caused by acupuncture stimulation lasted for
around 15 s after the stimulation.
|
2147. |
Single-Trial EEG
Discriminant Components Acquired During 3T fMRI ![](poster.gif)
Jennifer M Walz1, Jordan Muraskin1,
Robin I Goldman1, Truman R Brown2,
and Paul Sajda1
1Biomedical Engineering, Columbia University,
New York, NY, United States, 2Radiology
and Radiological Science, Medical University of South
Carolina, Charleston, SC, United States
We previously demonstrated that single-trial variability
(STV) of EEG components recorded simultaneously with
1.5T fMRI can yield task-relevant BOLD activations that
are unobservable using traditional fMRI analysis
methods. A higher field MR system provides greater SNR
of the fMRI BOLD signal, but reduces the SNR of the EEG
due to increased magnitude of gradient, BCG, and motion
artifacts. We have demonstrated the feasibility of our
EEG-fMRI STV analysis methods in the more challenging
environment of the higher-field 3T scanner, and we have
surpassed our previous results in EEG discrimination
performance, cluster size, and max z-score.
|
|
|
Traditional
Poster Session - fMRI |
|
Human fMRI: Systems Neuroscience
Click on
to view
the abstract pdf. Click on
to view
the poster (Not all posters are available for viewing.)
Thursday 10 May 20122
Exhibition Hall |
13:30 - 15:30 |
|
|
2148. |
Prolonged tasks during
steady state fMRI
Amir M Abduljalil1, Chima Oluigbo1,
Xiangyu Yang1, Ali Rezai1, Dustin
Cunningham1, Seongjin Choi1, and
Michael V Knopp1
1The Ohio State University, Columbus, Ohio,
United States
In Task based fMRI, the detectable activation is
expected to diminish as the task continues over one
minute. In this study, a comparison was made between a
scan of the subject at rest and a scan of the same
subject performing a task for the entire duration. The
calculated functional maps were generated from multiple
sections of the time series data in a sliding window
manner. A consistent differentiation was observed in the
independent components and seed-based functional maps
between the resting scans and the scans under extended
period of stimulation.
|
2149. |
Odorant Mediated vs.
Sniffing Mediated BOLD Activation in Human Primary Olfactory
Cortex
Xiaoyu Sun1, Jianli Wang1,
Christopher W Weitekamp1, Megha Patel1,
Jeffrey Vesek1, and Qing X Yang1,2
1Radiology, Pennsylvania State University
College of Medicine, Hershey, PA, United States, 2Neurosurgery,
Pennsylvania State University College of Medicine,
Hershey, PA, United States
The odor perception is intimately coupled with sniffing,
and both functions are processed in the primary
olfactory cortex (POC). A variety of studies on
mammalian olfactory systems have shown the spatial
distribution of the olfactory components in the
olfactory system. However, It is difficult to
differentiate odorant perception from sniffing in human
primary olfactory cortex using fMRI. In this study, we
demonstrated that the BOLD signals in the POC from
odorant stimulation can be separated and quantified from
those by sniffing, which opens up opportunities for
investigating mechanisms of olfactory deficits in
several neurodegenerative diseases.
|
2150. |
Olfactory Habituation in
the Human Brain
Jianli Wang1, Xiaoyu Sun1, Zackary
Herse1, Megha Patel1, Sarah Ryan1,
Jeffrey Vesek1, and Qing X Yang1,2
1Radiology, Penn State College of Medicine,
Hershey, PA, United States, 2Neurosurgery,
Penn State College of Medicine, Hershey, PA, United
States
As the brain’s BOLD signal responding to odorant
stimulation is strongly modulated by habituation and
respiration, quantitative assessment of olfactory
deficits in the brain using fMRI is complex. A thorough
understanding of the dynamic behavior of the BOLD signal
due to habituation in the central olfactory system is
essential for clinical applications of olfactory fMRI.
Published fMRI studies on human olfactory habituation
have been limited. In this study, we characterized the
dynamic behavior of the BOLD signal in human primary
olfactory cortex and related structures when subjected
to odor habituation.
|
2151. |
Brain Performance
Correlations with Oxygenation Levels and Neuronal Activity
in Resting State fMRI ![](poster.gif)
David Matthew Carpenter1, Edmund Wong1,
Jessica Roman1, and Cheuk Ying Tang1,2
1Radiology, Mount Sinai School of Medicine,
New York, New York, United States, 2Psychiatry,
Mount Sinai School of Medicine, New York, New York,
United States
Here we used the random fluctuations of the resting
state brain and capitalized on the hemodynamic delay of
BOLD fMRI to investigate what primes the brain for best
performance: preceding blood oxygenation levels or
preceding neuronal activity. The results show
correlation between response time (at T=0) and blood
oxygen levels of the default network (BOLD at T=0) but
not with neuronal activity of the network (BOLD at
T=2sec). Subjects’ performance was correlated to the
oxygen level and not the neuronal activity immediately
preceding level of activity.
|
2152. |
Comparison of Anesthetic
Effects on the Resting-State CBF between Sevoflurane and
Propofol: Similarities, Discrepancies, and their
Implications ![](poster.gif)
Maolin Qiu1, Ramachandran Ramani2,
and R. Todd Constable1
1Diagnostic Radiology, Yale University, New
Haven, CT, United States, 2Anesthesiology,
Yale University, New Haven, CT, United States
The anesthetic effects of different agents on CBF have
been investigated in recent years, however, variability
in results among the studies exists. We use pulsed
arterial spin labeling (PASL) MRI, with the similar
experiment protocols, to assess the regional CBF changes
in healthy human volunteers induced by sevoflurane and
propofol. Our results showed, in the presence of an
anesthetic, the observed regional CBF is the interplay
among local neuronal activity that contributes to the
regional changes in CBF via the neurovascular coupling,
the distributions of the neuroceptors as the molecular
targets of the agent, the neurophysiology of the brain,
i.e., the subsystems of the brain that the anesthetic
progressively suppressed, and the vascular structure of
the brain.
|
2153. |
Probing Neural Networks
Involved in Upregulation of Heart Rate and Blood Pressure
During Handgrip
Jinqi Li1, Michael Riedel2, Karl
Li3, Claudia Ivette Huerta2,
Hsiao-Ying Wey4, Jacob L Eisenrich3,
and Timothy Q Duong2
1Research Imaging Institute, San Antonio,
Texas, United States, 2Research
Imaging Institute, 3Medical
School, UT Health Sience Center, 4Harvard
University, United States
fMRI studies were done on four healthy subjects who
performed static handgrip. Two fMRI analyses were
performed using FSL: 1) block-correlation of rest versus
handgrip, and 2) linear-correlation with HR. Stronger
activations in insula, thalamus and anterior cingulate,
which were highly accepted as central command areas, in
block –correlation analysis largely disappeared in HR
correlation analysis. We concluded that the commonly
identified activation of thalamus and insular cortex,
anterior cingulated are likely to be involved in
performing the visual feedback tasks, but unlikely to be
the predominant central command networks that drive HR
or BP increases during exercise.
|
2154. |
BOLD, CBF, and CBV fMRI
measurements in chronic stroke patients reveal details of
altered neurovascular coupling ![](poster.gif)
Manus Donahue1,2, Charlotte Stagg2,
Jacinta O'Shea2, Peter Jezzard2,
Leif Ostergaard3, Bradley MacIntosh2,4,
Heidi Johansen-Berg2, and Jakob Blicher3
1Vanderbilt University, Nashville, TN, United
States, 2FMRIB
Centre, Oxford University, Oxford, Oxfordshire, United
Kingdom, 3Center
of Functionally Integrative Neuroscience, Aarhus
University, Aarhus, Denmark, 4Medical
Biophysics, University of Toronto, Toronto, Ontario,
Canada
The aim of this work is to apply a multi-modal,
noninvasive fMRI approach to better quantify hemodynamic
compensation mechanisms during stroke recovery (n=22).
Despite robust BOLD, CBF-weighted and CBV-weighted
reactivity changes in healthy subjects, in stroke
patients with motor impairment, BOLD-fMRI yielded no
significant (P>0.05) average changes, despite
significant (P<0.01) changes in CBF and CBV. Therefore
in chronic stroke, neuronal activity can lead to
measurable changes in CBF and CBV in expected cortical
areas despite an absent BOLD-fMRI response. Thus,
multi-modal fMRI may be better suited than BOLD-fMRI for
interrogating cortical reorganization under circumstance
of impaired neurovascular coupling.
|
2155. |
The Correlation between
the BOLD Contrast and Motor Execution Quantified by
Motion-capture Analysis of the Movements
Toshiharu Nakai1, Ichiro Takashima2,
Makoto Miyakoshi3, Shintaro Ninomiya4,
Ayuko Tanaka5, Kayako Matsuo6, and
Junichi Hasegawa4
1Neuroimaging & Informatics, NCGG, Ohbu,
Aichi, Japan, 2AIST,
Tsukuba, Ibaragi, Japan, 3JSPS,
Tokyo, Japan, 4Chukyo
University, Toyota, Aichi, Japan, 5NCGG,
Ohbu, Aichi, Japan, 6NTU,
Taipei, Taiwan
The relationship between the BOLD contrast in the
primary motor area and the motor performance quantified
by motion-capture analysis using conventional CCD camera
and color markers compatible with MRI was investigated.
Significant difference of the correlation gradient
corrected by the mean amplitude of the movements
determined was detected depending on the preciseness of
the movements (p<0.05). It was suggested that the
correlation between the BOLD signal and motor
performance is potentially biased by movement amplitude
instability.
|
2156. |
Thalamocortical vs.
Corticocortical Functional Connections during
Propofol-induced Anesthesia
Xiaolin Liu1, Barney D Ward1,
Shi-Jiang Li1, and Anthony G Hudetz2
1Department of Biophysics, Medical College of
Wisconsin, Milwaukee, Wisconsin, United States, 2Department
of Anesthesiology, Medical College of Wisconsin,
Milwaukee, Wisconsin, United States
In this study, we examined whether the loss of
consciousness in deep propofol sedation is more related
to a direct action of the propofol on corticocortical
functional connections or a disruption of
thalamocortical interactions, of particular interest,
the nonspecific thalamic network. We found that although
the nonspecific functional connectivity was
significantly diminished as the level of consciousness
was reduced, functional connectivity between the
cortical network nodes were not statistically altered
during deep sedation and the subsequent recovery. These
preliminary findings suggest that propofol-induced
reduction in the level of consciousness is reflected by
changes of the nonspecific thalamocortical connectivity
rather than by changes of the corticocortical
connections.
|
2157. |
An fMRI study of the
relative laterality of dominant and non-dominant hand
sensory function ![](poster.gif)
David F. Abbott1,2, Susan M. Palmer3,
Essie Low3, Graeme D. Jackson1,2,
and Leeanne M. Carey3,4
1Brain Research Institute, Florey
Neuroscience Institutes, Melbourne, Victoria, Australia, 2Department
of Medicine, The University of Melbourne, Melbourne,
Victoria, Australia, 3National
Stroke Research Institute, Florey Neuroscience
Institutes, Melbourne, Victoria, Australia, 4LaTrobe
University, Bundoora, Victoria, Australia
We used fMRI to explore the relative lateralisation of
brain activity associated with controlled tactile
stimulation of the fingertips of the left or right hand,
in thirteen healthy subjects. An adaptive and largely
threshold independent method of objectively determining
laterality was adapted for this study to permit
statistical comparison of the laterality of activity
associated with dominant-hand compared to laterality of
activity associated with non-dominant-hand stimuli. We
found that subjects are more strongly lateralised in
secondary somatosensory cortex for sensory stimuli of
their dominant right-hand than for similar stimuli
applied to their non-dominant left hand.
|
2158. |
Common and Unique Neural
Regions Activated During Simple Hand Movements: Implications
for Understanding Plasticity After Peripheral Nerve Damage ![](poster.gif)
Rebecca D. Ray1, Michelle Johnson2,
and Christopher Pawela3
1Plastic Surgery, Medical College of
Wisconsin, Milwaukee, WI, United States, 2Physical
Medicine and Rehabilitation, Medical College of
Wisconsin, Milwaukee, WI, United States,3Plastic
Surgery and Biophysics, Medical College of Wisconsin,
Milwaukee, WI, United States
Can specific hand movements be mapped onto unique brain
regions? This study investigates the common and
different representations of individual hand movements
(grasp, index finger flexion and extension, finger
spread and thumb raise). Participants wore MRI
compatible sensor gloves to measure finger flexure and
the orientation (pitch and roll) of the user’s hand as
they controlled a small black dot. Several key regions
are common to these tasks. There are also activated
regions unique to each task. Understanding how motor
tasks map onto specific neural regions allows
investigators to study plasticity following nerve damage
and other disorders of the nervous system.
|
2159. |
Dynamic Behavior of BOLD
Signal and the Associated Olfactory Neural Networks: A
Functional Magnetic Resonance Imaging Study
Prasanna Karunanayaka1, Chris Weitekamp11,
Kathleen Gates2, Jianli Wang1,
Paul Eslinger3, Peter Molenaar2,
and Quing Yang1
1Radiology, Penn State University, Hershey,
PA, United States, 2Human
Development and Family Studies, Penn State University,
University Park, PA, United States,3Neurology,
Penn State University, Hershey, PA, United States
Using fMRI data, we present a novel approach capable of
revealing the olfactory network that subserve a
four-strength fMRI paradigm. The method entails
combining unified Structural Equation Modeling (uSEM)
and group independent component analysis (ICA) to
investigate the underlying olfactory network structure.
A significant finding of this study is the
identification of primary as well as secondary networks
that subserve olfactory processing. Thus, the approach
presented and described in this paper highlights the
advantage of analyzing olfaction in terms of cognitive
modules based on underlying network structure(s).
|
2160. |
Somatotopic Mapping of
Individual Fingers with a novel Vibrotactile Stimulator
using BOLD fMRI at 3T
Sunil K. Valaparla1,2, Hsiao-Ying (Monica)
Wey1,2, William E. Rogers1, Jinqi
Li1, Geoffrey D Clarke2, and
Timothy Q. Duong1,2
1Research Imaging Institute, University of
Texas Health Science Center San Antonio, San Antonio,
Texas, United States, 2Radiology,
University of Texas Health Science Center San Antonio,
San Antonio, Texas, United States
High resolution mapping of somatotopy remains an active
area of research. In this study, we: i) designed and
constructed a MRI-compatible stimulator working on
magneto-mechanical principles that is applicable for a
wide-range of stimulation frequencies, ii) implemented
high-resolution fMRI studies with 1.5 mm isotropic
resolution to map human finger somatosensory cortex
(S1), iii) mapped out the tuning curve as a function of
stimulation frequency, and iv) applied the optimal
conditions to map finger somatotopy.
|
2161. |
Simultaneous Real-time
fMRI and EEG Neurofeedback for Self-Regulation of Human
Brain Activity ![](poster.gif)
Vadim Zotev1, Raquel Phillips1,
Han Yuan1, Wayne Drevets1, and
Jerzy Bodurka1
1Laureate Institute for Brain Research,
Tulsa, OK, United States
We have employed novel integration of real-time
functional magnetic resonance imaging (rtfMRI) and
encephalography (EEG) to provide simultaneous rtfMRI-EEG
multimodal neurofeedback for regulation of both
hemodynamic and electrophysiological activity of the
human brain. We demonstrated, for the first time, that
healthy participants can learn to simultaneously
regulate their frontal high-beta EEG asymmetry and left
amygdala fMRI activation using retrieval of positive
autobiographical memories along with rtfMRI-EEG
neurofeedback. This proof-of-concept study opens up
possibilities for development of novel cognitive
neuroscience research paradigms and enhanced cognitive
therapeutic approaches for major neuropsychiatric
disorders.
|
|
|
Traditional
Poster Session - fMRI |
|
fMRI: Animal Neuroscience
Click on
to view
the abstract pdf. Click on
to view
the poster (Not all posters are available for viewing.)
Thursday 10 May 2012
Exhibition Hall |
13:30 - 15:30 |
|
|
2162. |
fMRI/fcMRI investigation
showing cortical and subcortical pathways involving in
phrenic nerve activation and respiration control in rats
under 9.4Tesla.
Rupeng Li1, Nicholas Flugstad2,
Xiping Liu3, Christopher Pawela1,2,
Ji-Geng Yan2, Hani S Matloub2, and
James S Hyde1
1Biophysics, Medical College of Wisconsin,
Milwaukee, WI, United States, 2Plastic
Surgery, Medical College of Wisconsin, Milwaukee, WI,
United States, 3Anesthesiology,
Medical College of Wisconsin, Milwaukee, WI, United
States
Cortical and subcortical pathways accouting for phrenic
nerve function were discovered with the combination of
BOLD fMRI and fcMRI for the first time.It helps with
further investigation of respiratory system control and
provide physiological basis for this nerve to be used as
donor for peripheral nerve injury repair.
|
2163. |
Elucidating bilaterality
of fMRI BOLD signal change in the mouse brain upon
unilateral innocuous and noxious paw stimulation ![](poster.gif)
Aileen Schroeter1, Joanes Grandjean1,
Aline Seuwen1, Bechara Saab2, and
Markus Rudin1,3
1Institute for Biomedical Engineering,
University and ETH, Zürich, Switzerland, 2Institute
for Brain Research, University and ETH, Zürich,
Switzerland, 3Institute
of Pharmacology and Toxicology, University, Zürich,
Switzerland
FMRI has been widely used to assess changes in brain
activity evoked by innocuous and noxious stimuli. In our
laboratory, the application of established sensory
stimulation paradigms to isoflurane-anesthetized mice
yields consistent bilateral BOLD signal changes in the
brain. This observation stands in contrast to the
majority of fMRI studies reporting predominantly
contralateral brain responses during unilateral
innocuous and mild noxious paw stimulation in healthy
rats and mice. The presented study deals with the
characterization and clarification of the bilateral BOLD
signal change in the mouse brain and should yield to
more insight into interhemispheric processing of
unilateral peripheral stimuli.
|
2164. |
BOLD fMRI Response of the
Rat Brain to Bolus Injection of Hypertonic Saline
Bianca Gonzales Cerqueira1, Qiang Shen1,
Fang Du1, Glenn M. Toney2, and
Timothy Q. Duong1
1Research Imaging Institute, University of
Texas Health Science Center at San Antonio, San Antonio,
TX, United States, 2Department
of Physiology, University of Texas Health Science Center
at San Antonio, San Antonio, TX, United States
Osmoregulation is an essential function in mammals. This
study uses BOLD fMRI to investigate rat brain activation
in response to a 200µl bolus injection of hypertonic
saline into the right internal carotid. Activated areas
are cingulate cortex, somatosensory cortex, fornix,
periaqueductal gray, field CA3 of hippocampus,
hypothalamic paraventricular nucleus, insula, median
preoptic nucleus, and organsum vasculosum laminae
terminalis. We found novel sites of activation as well
as established areas that are consistent with
osmoregulatory circuits reported in
electrophysiological, histological, and lesion studies.
Our ultimate goal is to identify and validate new sites
for targeting treatment of salt-sensitive forms of
hypertension.
|
2165. |
Plasticity of the rat
sensory cortex at 9.4T demonstrated in a survival model of
brachial plexus injury and repair with contralateral C7
nerve transfer
Nicholas A Flugstad1, Jack B Stephenson1,
Rupeng Li2, Ji-Geng Yan1,
Christopher Pawela2, Hani S Matloub1,
and James S Hyde2
1Plastic Surgery, Medical College of
Wisconsin, Milwaukee, WI, United States, 2Biophysics,
Medical College of Wisconsin, Milwaukee, WI, United
States
9.4T fMRI was done in a controlled rat survival model
after total brachial plexus avulsion and cross C7 nerve
tranfer. fMRI scans at 0, 3, 5, and 7 months after
repair demonstrated remodeling of the sensory cortex of
the rat forepaw. Over time, the signal migrated from the
ipsilateral sensory cortex to the contralateral sensory
cortex. This represents trans-hemispheric cortical
remodelling and restoration of native somatotopy. After
cross C7 nerve trnsfer, the rat brain seems to be
capable of higher level reorganization in order to
restore sensory input to its native anatomical location
in the cortex.
|
2166. |
Methylene Blue (a
Metabolic Enhancer) Increases Basal CBF, and Hypercapnic and
Functional fMRI Responses ![](poster.gif)
Shiliang Huang1, Fang Du1, Yen-Yu
I Shih1, Qiang Shen1, Ai-Ling Lin1,
Shao-Hua Yang2, and Timothy Q Duong1
1Reseach Imaging Institute, University of
Texas Health Science Center at San Antonio, San Antonio,
TX, United States, 2Department
of Pharmacology and Neuroscience, University of North
Texas Health Science Center at Fort Worth, Fort Worth,
TX, United States
Methylene blue (MB) is FDA-approved to treat
methemoglobinemia and cyanide poisoning and it has
recently been shown to be neuroprotective in stroke,
Alzheimer and Parkinson diseases in preclinical and
clinical studies. MB enhances ATP production by acting
as an electron donor in the mitochondrial electron
transport chain. It also reduces free radical production
under metabolically stressed conditions. This study used
MRI to investigate the effects of MB on hemodynamic and
metabolic parameters. We found that MB increases basal
BF, hypercapnia-induced and forepaw-stimulation fMRI
responses and oxygen consumption during forepaw
stimulation. These results support the positive benefits
of MB for treatments.
|
2167. |
Potentiation of the
metabotropic glutamate receptor subtype 5 modulates
dopaminergic neurotransmission
Nellie Byun1,2, Ayan Ghoshal1,3,
Nathaniel D. Kelm2,4, Robert L. Barry2,5,
Wellington Pham2,5, Carrie K. Jones1,3,
John C. Gore2,5, and P. Jeffrey Conn1,3
1Vanderbilt Center for Neuroscience Drug
Discovery, Nashville, TN, United States, 2Vanderbilt
University Institute of Imaging Science, Nashville, TN,
United States,3Pharmacology, Vanderbilt
University Medical Center, Nashville, TN, United States, 4Biomedical
Engineering, Vanderbilt University, Nashville, TN,
United States, 5Radiology
& Radiological Sciences, Vanderbilt University Medical
Center, Nashville, TN, United States
Previous preclinical studies have demonstrated the
potential of compounds that target the metabotropic
glutamate receptor subtype 5 (mGluR5) for the treatment
of schizophrenia. Like typical and atypical
antipsychotic drugs, the novel selective mGluR5
potentiator VU0360172 suppressed amphetamine-induced
hyperlocomotion in rodents. Here we used VU0360172 and
pharmacologic MRI (phMRI) to determine specific regions
of mGluR5-mediated modulation of amphetamine-induced
brain activation as well as the effects of VU0360172
alone.
|
2168. |
Longitudinal fMRI of
Spontaneous Plasticity in Rats After Focal Stroke Under
Alpha-Chloralose Anesthetic ![](poster.gif)
Tobias C Wood1, Denise Duricki2,
Lawrence Moon2, Camilla Simmons1,
Michel Mesquita1, Steven Williams1,
and Diana Cash1
1Department of Neuroimaging, King's College
London, London, United Kingdom, 2Wolfson
Centre for Age Related Diseases, King's College London
We present a longitudinal fMRI study of focal stroke
recovery in adult rats under Alpha-Chloralose anesthetic
using forepaw stimulation. Spontaneous plasticity was
observed, confirming this protocol is suitable for use
with repeated imaging experiments.
|
2169. |
Frequency distribution of
the BOLD signal during resting-state and nicotine infusion
in mice using a phased-array cryogenic coil at 9.4T ![](poster.gif)
Joanes Grandjean1, and Markus Rudin1,2
1Institute for Biomedical Engineering, ETH
and University, Zürich, Switzerland, 2Institute
of Pharmacology and Toxicology, University of Zürich,
Switzerland
Resting-state fMRI in mice has been limited due to small
voxel-size, leading to low SNR. It would allow studying
mechanisms underlying resting-state fMRI, and provide a
translational platform. In this study, we measured the
amplitudes of low-frequency fluctuation (ALFF) of the
fMRI signal during resting-state and nicotine infusion
in mice and showed the organization of ALFFs in the
mouse brain. Nicotine infusion increased low frequencies
in the frontal cortex, and decreased medium frequencies
in the sensory/motor cortex. Analysis of the ALFFs may
be used to study resting-state fMRI in mice and
frequency distribution can be altered following an
intervention.
|
2170. |
Classification of neural
activity patterns observed by phMRI upon pharmacological
interventions in rats ![](poster.gif)
Basil Künnecke1, Andreas Bruns1,
Eric Prinssen1, Jean-Luc Moreau1,
Joseph G Wettstein1, Markus von Kienlin1,
and Céline Risterucci1
1CNS Research, F. Hoffmann-La Roche Ltd,
Basel, Switzerland
Preclinical pharmacological fMRI (phMRI) has been
successfully used to elucidate the effects of
psychoactive drugs on regional cerebral activity, but
comparative meta-analyses of study ensembles are largely
missing. The present work provides such a systematic and
quantitative analysis of perfusion-based phMRI data
obtained upon interventions with an extensive set of
neuroactive reference compounds impacting on the domains
of anxiety and depression. Neural activity patterns
detected by phMRI were subjected to principal component
analysis in order to yield specific signatures for the
drugs’ modes-of-action and objective measures of
dose-effect and treatment duration-effect relationships.
|
2171. |
Blood oxygenation
level-dependent functional magnetic resonance imaging
analysis of functional representation of taste information
processing in the rat brain ![](poster.gif)
Ikuhiro Kida1, Yoshinobu Iguchi1,
and Yoko Hoshi1
1Tokyo Metropolitan Institute of Medical
Science, Setagaya-ku, Tokyo, Japan
The neuronal mechanisms underlying taste discrimination
and perception in cortical and subcortical regions
remain unclear. We performed blood oxygenation
level-dependent (BOLD) functional magnetic resonance
imaging at 7 T to clarify the neuronal network in the
cortical and subcortical regions for taste
discrimination. Sucrose and NaCl stimulation increased
and decreased the BOLD signals, respectively, in the
insular cortex and regions like the caudate-putamen and
nucleus accumbens core. This suggests that the activated
regions differed but overlapped for taste
discrimination. The correlation between the signals in
such regions may be related to positive and negative
emotional and affective processes, including food
preferences.
|
2172. |
Retinal and Choroidal
Blood Flow Autoregulation in Rats at 11.7T
Guang Li1, Yen-Yu I. Shih2, Bryan
H. De La Garza2, Jeffrey W. Kiel3,4,
and Timothy Q. Duong2
1Radiology, University of Texas Health
Science Center at San Antonio, San Antonio, TX, United
States, 2Research
Imaging Institute, University of Texas Health Science
Center at San Antonio, San Antonio, TX, United States, 3Ophthalmology,
University of Texas Health Science Center at San
Antonio, San Antonio, TX, United States, 4Physiology,
University of Texas Health Science Center at San
Antonio, San Antonio, TX, United States
Autoregulation of ocular blood flow (BF) with respect to
changing blood pressure (BP) is important to retinal
health. Autoregulation dysfunction has been implicated
in many retinal diseases such as glaucoma. This study
investigated changes in BF and
blood-oxygen-level-dependence (BOLD) MRI of the retinal
and choroidal vasculatures in the retina with respect to
increased blood pressure (BP), which is induced by
transient partial occlusion of the descending aorta. We
found that BF in both of the retinal and choroidal
vasculatures was tightly regulated. This approach sets
the stage for study of retinal diseases in which
autoregulation may be perturbed.
|
2173. |
Rodent resting-state fMRI
in the transition to chronic pain: relating functional
connectivity to receptor expression changes ![](poster.gif)
Pei-Ching Chang1, Sara Pollema1,
Maria Virginia Centeno1, Daniele Procissi2,
Marwan Baliki1, Marco Martina1,
and A. Vania Apkarian1
1Departments of Physiology, Northwestern
University, Chicago, IL, United States, 2Departments
of Radiology, Northwestern University, Chicago, IL,
United States
In this study, we combined rs-fMRI and receptors
expression to evaluate the mechanisms of transition from
an acute peripheral nerve injury to chronic neuropathic
pain. We showed that enhanced functional connectivity in
NAc with prefrontal regions in the neuropathic pain
animals, consistent with increased PFC-NAc connectivity
we observed in chronic pain patients. Furthermore,
significant correlation between functional connectivity
and receptors expression was observed in the neuropathic
pain animals. This is the first demonstration of a link
between human and animal fMRI for transition to chronic
pain, and the first evidence relating changes in
receptors expression and functional connectivity.
|
2174. |
Frequency dependant brain
activation during somatosensory stimulation in anaesthetised
rats: a comparison using evoked potentials, quantitative
2-deoxyglucose autoradiography and fMRI
Diana Cash1, Camilla Simmons1,
Alanna C Easton2, David J Lythgoe1,
Steven CR Williams1, and Michel SB Mesquita1
1Neuroimaging, King's College London, London,
United Kingdom, 2Neuroscience,
King's College London, London, United Kingdom
Forepaw sensory stimulation at 0.5 and 3 Hz in
anaesthetized rats was characterized for BOLD fMRI,
neural activity and regional glucose uptake. Electrical
activity was greater at lower frequency whereas
metabolic activity was greater at higher frequency. An
expected increase in BOLD in forepaw cortex was detected
at 3Hz, but a widespread negative BOLD signal was
detected at 0.5Hz, suggesting the lack of neurovascular
coupling at this slow stimulation rate.
|
2175. |
Frequency cutoff in
neurovascular coupling of resting-state fMRI
Wen-Ju Pan1, Garth Thompson1,
Matthew Magnuson1, and Shella Keilholz1
1Biomedical Engineering, Emory
University/Georgia Institute of Technology, Atlanta, GA,
United States
BOLD fluctuations typically exhibit high power only in
the low frequencies (<0.1). The mechanism of the
frequency cutoff has been rarely investigated. By
simultaneous intracortical DC recording and fMRI, the
DC/BOLD coherences were demonstrated within a frequency
range of high BOLD power, and can be modulated by
vasoactive properties in a rat model.
|
2176. |
Vibrotactile and
Electrocutaneous Stimuli Activate Distinct but Overlapping
Areas in Primary Somatosensory Cortex that Differ in their
Stimulus-Response Properties ![](poster.gif)
Feng Wang1, Robert Friedman1,
Chaohui Tang1, and Malcolm Avison1
1Vanderbilt University, Nashville, TN, United
States
To examine the role of dorsal column (DC) and
spinothalamic (ST) spinal cord afferents to primary
somatosensory (SI) cortex, we compared the cortical and
thalamic topography and stimulus response properties
associated with vibrotactile (VS) and electrocutaneous
stimulation (ES) of single digits in anesthetized
squirrel monkeys. VS, which activates only the DC inputs
and ES, which activates both DC and ST afferents,
elicited similar stimulus responses in area 3b, but very
different responses in areas 1 and 3a.
|
2177.
![](MAGNA25.jpg) |
Coupling of long
projecting vasoactive dopaminergic afferents to negative
fMRI signals in the striatum
Yi-Hua Hsu1,2, Chiao-Chi V Chen2,
Yen-Yu I Shih3, and Chen Chang1,2
1Institute of Pharmacology, National
Yang-Ming University, Taipei, Taiwan, Taiwan, 2Institute
of Biomedical Sciences, Academia Sinica, Taipei, Taiwan,
Taiwan, 3Research
Imaging Institute, University of Texas Health Science
Center at San Antonio, San Antonio, Texas, United States
Vasoactive neurotransmitters are a direct cause of
negative fMRI signals. Dopamine, for instance, can be
vasoconstrictive. The dopaminergic system mainly
involves a long projection from the substantia nigra to
the striatum. The coupling of the fMRI signals with a
long vasoactive pathway raises the issue whether the
negative fMRI response represents remote rather than
local neuronal activity. To clarify, a local anesthetic
was used to block the local or remote site of the
pathway during induction of the negative fMRI signals.
The results indicate that the negative fMRI signals are
directly coupled to remote neuronal activation without
involving local neurons.
|
2178. |
Amplitude Modulation
Frequency and Duty Cycle Processing in the Auditory System:
An fMRI Investigation ![](poster.gif)
Joe S. Cheng1,2, Patrick P. Gao1,2,
Condon Lau1,2, Jevin W. Zhang1,2,
Matthew M. Cheung1,2, Iris Y. Zhou1,2,
and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal
Processing, The University of Hong Kong, Hong Kong SAR,
China, 2Department
of Electrical and Electronic Engineering, The University
of Hong Kong, Hong Kong SAR, China
Amplitude modulations (AMs) are an essential cue for
recognizing and categorizing behaviorally relevant sound
and broad tends concerning the coding of AMs parameters
use electrophysiology techniques[1-3].
|
2179. |
How does whisker
stimulation modulate ongoing electrophysiological signal?
Implications for resting state fMRI
Hanbing Lu1, Leiming Wang1,
William W Rea1, Elliot A Stein1,
and Yihong Yang1
1National Institute on Drug Abuse, NIH,
Baltimore, MD, United States
Spontaneous fluctuations in the resting state fMRI time
course have been shown to exhibit structured spatial and
temporal patterns. However, the underlying mechanisms
are still poorly understood. The goal of this study is
to investigate how tasks modulate ongoing spontaneous
fluctuations.
|
2180. |
Noninvasive fMRI
Investigation of Interaural Level Difference Processing in
the Rat Subcortex ![](poster.gif)
Condon Lau1,2, Jevin W. Zhang1,2,
Joe S. Cheng1,2, Kyle K. Xing1,2,
Iris Y. Zhou1,2, Matthew M. Cheung1,2,
and Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal
Processing, The University of Hong Kong, Hong Kong, Hong
Kong SAR, China, 2Department
of Electrical and Electronic Engineering, The University
of Hong Kong, Hong Kong, Hong Kong SAR, China
Interaural level differences (ILDs) are important
features for sound localization. Sound arrives at the
ears with different sound pressure levels (SPLs)
depending on the azimuth of the source. fMRI with seven
ILD settings spanning ±18dB (higher SPL in left ear is
positive) is used to examine a rat model of subcortical
ILD processing. Results show the inferior colliculus and
dorsal lateral lemniscus contralateral to the higher SPL
ear respond with larger signal change. This asymmetry is
not apparent in the cochlear nucleus and superior
olivary complex. These findings demonstrate fMRI is an
effective tool for examining subcortical ILD processing.
|
2181. |
Investigation of the BOLD
contrast mechanisms initiated during prolonged trigeminal
nerve stimulation
Nathalie Just1, and Rolf Gruetter1,2
1LIFMET, CIBM/EPFL, Lausanne, Switzerland, 2Department
of Radiology, Universities of Lausanne and Geneva,
Switzerland
BOLD fMRI investigations in rodents are useful to
understand and interpret the underlying physiological
and molecular mechanisms of brain activation. Neurons of
the whisker barrel system in the rodent primary
somatosensory cortex are known to encode external events
in time and space and thus offer an excellent model to
study BOLD activation processes. In the present study,
we proposed to investigate the BOLD contrast mechanisms
initiated during sustained trigeminal nerve (TGN)
stimulation in the rat since different stimulation
durations could potentially result in different
activation maps themselves resulting from the
recruitment of different neuronal, vascular or metabolic
mechanisms.
|
2182. |
Laminar-specific BOLD
Functional MRI of the Human Retina to Hyperoxia Inhalation
Yi Zhang1,2, Oscar San Emeterio Nateras1,
Qi Peng1, and Timothy Duong1,2
1Radiology, University of Texas Health
Science Center at San Antonio, San Antonio, TX, United
States, 2Research
Imaging Institute, University of Texas Health Science
Center at San Antonio, San Antonio, TX, United States
The human retina is supplied by two (retinal and
choroidal) separate vasculatures and their integrity is
vital for maintaining normal retinal structure and
function. This study demonstrates a novel BOLD fMRI
application in the human retina with laminar
specificity, made possible by stable eye fixation and
bSSFP acquisition. Inversion-recovery bSSFP with
reversed partial-Fourier readout was used to suppress
the vitreous and to achieve strong BOLD-sensitivity
without distortion. bSSFP fMRI reveals differential BOLD
responses to hyperoxia in retinal and choroidal
vasculatures. This approach could provide useful
physiological information of the retina in healthy and
diseased states, and complement existing imaging
techniques.
|
2183. |
BOLD fMRI of Rat Retina at
11.7 Tesla ![](poster.gif)
Bryan H DeLaGarza1, Eric R Muir1,
William E Rogers1, and Timothy Q Duong1
1Research Imaging Institute,
Ophthalmology/Radiology, Univ of Texas Health Science
Center at San Antonio, San Antonio, TX, United States
This study reports a novel application of BOLD fMRI of
visual stimulation in the rat retina at 11.7 Tesla.
Visual stimuli employed diffuse achromatic light
flickering at 8 Hz. Higher magnetic field was used to
improve signal-to-noise ratio, spatial resolution
(110x110x1000 microns) and BOLD contrast sensitivity.
This approach can be used to evaluate functional changes
in the rat retinas where many retinal disease models are
readily available. BOLD fMRI of the retina provides
unique clinically relevant data and has the potential to
complement existing retinal imaging techniques.
|
|
|
Traditional
Poster Session - fMRI |
|
Click on
to view
the abstract pdf. Click on
to view
the poster (Not all posters are available for viewing.)
Thursday 10 May 2012
Exhibition Hall |
13:30 - 15:30 |
|
|
2184. |
High Temporal Resolution
In-Vivo Blood Oximetry via Projection Based T2 Measurement
Varsha Jain1, Jeremy Magland1,
Michael Langham1, and Felix W Wehrli1
1Department of Radiology, University of
Pennsylvania, Philadelphia, PA, United States
Measuring oxygen saturation (SvO2) in large blood
vessels can provide important information about oxygen
delivery and its consumption. Quantification of blood’s
T2 value can be utilized to determine SvO2.We propose a
fast method for blood T2 quantification via computing
the complex difference of velocity-encoded
projections.Average resting state SvO2 measurements in
superior sagittal sinus,straight sinus, left and right
internal jugular veins in the three subjects were 65±3
%, 70±1%, 68±3% and 69±3%, respectively, in agreement
with previous reports. Additionally, in concurrence with
the known vasoldilatory effect of hypercapnia SvO2
levels increased by ~10%HbO2. Potential clinical
applications extend to the study of pathological
conditions affecting cerebral metabolism, for example,
neurodegenerative conditions such as Alzheimer’s
dementia.
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2185. |
Characterization of Blood
Pool Half Life of USPIO Contrast Agent Ferumoxytol in Humans
Deqiang Qiu1, Thomas Christen1,
Wendy W Ni1, Greg Zaharchuk1, and
Michael E Moseley1
1Radiology, Stanford University, Stanford,
CA, United States
Ultra Small Paramagnetic Iron Oxide (USPIO) contrast
agents have a strong T2* effect, which allows
steady-state high-resolution quantitative Cerebral Blood
Volume mapping (CBV) as well as enhanced sensitivity for
fMRI based on CBV changes. We characterized the
half-life of an FDA-approved USPIO compound ferumoxytol
(AMAG Pharmaceuticals, Inc., Cambridge, MA) in humans.
The R2* values of the brain before and after contrast
injection as well as at follow-up sessions were
obtained. The half-life of the contrast agent was
estimated to range from 12.1 hours to 22.6 hours, longer
than that measured in animal studies.
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2186. |
Cerebral Blood Volume
Changes During Brain Activation ![](poster.gif)
Steffen Norbert Krieger1, Robert Trampel1,
Markus Streicher1, and Robert Turner1
1Neurophysics, Max Plank Institute for Human
Cognitive and Brain Sciences, Leipzig, Saxonia, Germany
Due to its good localization to neuronal activity, fMRI
studies have begun to utilize changes of cerebral blood
volume (CBV). However, if cerebral vessels are
considered to be impermeable, the contents of the skull
incompressible, and the skull itself inextensible,
task-related and hypercapnia-related changes of CBV
could produce intolerable changes of intracranial
pressure. We propose that much of the change in CBV is
facilitated by exchange of water between capillaries and
surrounding tissue. To explore this idea we developed a
novel hemodynamic boundary-value model and found
approximate solutions. A macroscopic experimental model
provides biophysical insight.
|
2187. |
Mapping of CMRO2 changes
in visual cortex during a visual motion paradigm at 7T
Dimo Ivanov 1, Laurentius Huber 1,
Stefan Kabisch 1,2, Markus Streicher 1,
Haiko Schloegl 1,2, Ilona Henseler 1,
Elisabeth Roggenhofer 1, Wolfgang Heinke 3,
and Robert Turner 1
1Max Planck Institute for Human Cognitive and
Brain Sciences, Leipzig, Germany, 2Department
of Medicine, University Hospital Leipzig, Leipzig,
Germany, 3Department
of Anesthesiology and Intensive Care Therapy, University
Hospital Leipzig, Leipzig, Germany
|
2188. |
What is the best way to
use hyperoxia to measure venous cerebral blood volume? ![](poster.gif)
Nicholas P Blockley1, and Richard B Buxton1
1Center for Functional MRI, University of
California San Diego, La Jolla, California, United
States
Measurement of the BOLD response to hyperoxia has been
proposed as a way to measure venous cerebral blood
volume. We simulated two methods of achieving this aim
with a detailed BOLD signal model, testing each for
sensitivity to intersubject variations in haematocrit
and baseline oxygen extraction. The first was the
original method of normalising the tissue signal
response to hyperoxia by the signal response of a large
vein. The second was a new method based only on the
tissue signal response. Compared with the original
approach, this new method was found to be much less
sensitive to intersubject variability.
|
2189. |
Hyperoxia Modulated Evoked
Cerebral Blood Flow in the Human motor Cortex: Measured with
LL-FAIR ASL
Paula L. Croal1, Emma L. Hall1,
Ian D. Driver1, Penny A. Gowland1,
and Susan T. Francis1
1Sir Peter Mansfield MR Centre, University of
Nottingham, Nottingham, Nottinghamshire, United Kingdom
Local CBF (LCBF) is currently thought to increase on
cortical activation to meet an increased demand in
oxidative metabolism. However, animal literature
suggests that this increase is dominated by a change in
the vascular reactivity, as the LCBF response is higher
with hyperoxia. This study measures the LCBF response in
the human motor cortex on hyperoxia using LL-FAIR-ASL. A
trend was seen, with hyperoxia increasing the LCBF
response and reducing transit times to a greater extent
than normoxia. This finding raises questions as to
whether the role of functional hyperaemia is driven by
changes in metabolic demand or vasculature reactivity.
|
2190. |
Small changes in relative
CMRO2 during
stepped hypercapnia? ![](poster.gif)
Stefan Alexandru Carp1, Woo Hyun Shim1,
Jeong Kon Kim1, and Young Ro Kim1
1Massachusetts General Hospital, Charlestown,
MA, United States
Hypercapnic (CO2) calibration is necessary to be able to
measure relative changes in the cerebral metabolic rate
of oxygen (CMRO2) during evoked fMRI responses. The
underlying assumption is that there are no metabolic
changes associated with CO2 inhalation. In this work we
administered several levels of CO2 (2.5, 5 and 7.5%) to
anesthetized rats and compared relative CMRO2 values
between these levels. We observe that when calibrating
with the 2.5% to 5% transition, 7.5% CO2 appears to
result in lower cerebral oxygen demand. This may be a
result of BOLD signal contamination due to venous volume
changes.
|
2191. |
Quantification of Venous
Vessel Size in Human Brain in Response to Hypercapnia and
Hyperoxia
Yuji Shen1, and Ida M Pu2
1Brain Research Imaging Centre, University of
Edinburgh, Edinburgh, Scotland, United Kingdom, 2Department
of Computing, Goldsmiths, University of London, London,
United Kingdom
Hypercapnia and hyperoxia-induced BOLD contrasts were
employed to measure the mean venous vessel size in human
brain in response to hypercapnia and hyperoxia. A
combined GE and SE sequence was used to acquire GE and
SE signals simultaneously. The experimental paradigm
consisted of two 3-minute blocks of breathing 6% CO2 or
100% O2 interleaved with three 2-minute blocks of
breathing room air. The vessel size index q = ÄR2*/ÄR2
was calculated and then converted to the vessel radius.
It was found that the mean venous vessel radii were
larger in hypercapnia than in hyperoxia in both grey and
white matter.
|
2192. |
Hypercapnia-Induced Vessel
Size Imaging at 3 Tesla using PROPELLER-EPI
Martin Krämer1, Andreas Deistung1,
Thies H Jochimsen2, and Jürgen R Reichenbach1
1Medical Physics Group, Department of
Diagnostic and Interventional Radiology I, Jena
University Hospital, Jena, Germany, 2Klinik
und Poliklinik für Nuklearmedizin, Universitätsmedizin
Leipzig, Leipzig, Germany
Vessel size imaging at 3T requires sensitive mapping of
the transverse gradient-echo and spin-echo relaxation
rates. To realize hypercapnia-induced vessel size
imaging at lower clinical field strength we demonstrate
that the PROPELLER-EPI technique can be applied for this
purpose. Results shown from our in-vivo study at 3T are
then compared to a previous single-shot EPI study
performed at 7T.
|
2193. |
Influence of CO2 on
Cerebral O2 metabolism
during sustained hypoxia
Zachary M Smith1, Ethan Li1, and
David J Dubowitz1
1Center for Functional MRI, University of
California San Diego, La Jolla, California, United
States
Hypobaric hypoxia is accompanied by an increase in
cerebral O2 metabolism.
During acute hypoxia this CMRO2 rise
can be paritally mitigated by maintaining arterial CO2 at
its normoxic level. We investigated if acetazolamide (a
carbonic anhydrase inhibitor that increases CO2 in
the cerebral tissues) modulated this CMRO2 increase
during sustained hypoxia. CMRO2 was
measured using ASL and TRUST at 3T in human volunteers
during normoxia, and following 2-days sustained hypoxia
with or without treatment with acetazolamide. Following
acetazolamide, the hypoxia-induced rise in CMRO2 was
reduced. These data provide evidence for a CO2 dependence
of the CMRO2 rise
during sustained hypobaric hypoxia.
|
2194. |
Interaction of CBF
reactivity to hypoxia and to hypercapnia
Zachary M Smith1, Ethan Li1, and
David J Dubowitz1
1Center for Functional MRI, University of
California San Diego, La Jolla, California, United
States
Cerebral blood flow (CBF) and pulmonary ventilation both
increase with hypercapnia or hypoxia. We investigated 1)
the CBF reactivity to isolated hypoxia and isolated
hypercapnia, 2) reactivity to both stimuli in
combination and 3) impact of prolonged hypoxic
acclimatization on CBF response. Results were compared
with ventilation reactivity. Following 7-days hypoxic
acclimatization ventilatory reactivity to hypoxia
increased, whereas CBF reactivity diminished. For
combined hypoxic/hypercapnic stimuli, CBF shows an
additive increase in sensitivity, whereas ventilation
shows a multiplicative increase. However, after hypoxic
acclimatization, the response in both CBF and
ventilation is multiplicative. These differences in CBF
and ventilatory sensitivity may provide insights into
the mechanisms of hypoxic and CO2 modulation
of CBF.
|
2195.
![](SUMMA25.jpg) |
Adaptation of cerebral
blood flow and oxygen metabolsim and modulation of
neurovascular coupling with prolonged stimulation in human
visual cortex ![](poster.gif)
Farshad Moradi1, and Richard B Buxton1
1Radiology, Univeristy of California, San
Diego, San Diego, California, United States
After prolonged stimulation, the flow and metabolic
activity in the visual cortex undergo significantly
reduction. However, the BOLD signal did not show a
significant adaptation due to the changes in
neurovascular coupling opposing the effect of flow
adaptation. Our results demonstrate that the coupling
between flow and neural activity not only depends on
attention and contrast, but also on structure of the
stimulus (continuous versus intermittent presentation)
and sensory adaptation.
|
2196. |
Calibrated BOLD: measuring
task-related changes in CMRO2 at
baseline and elevated CBF ![](poster.gif)
Kevin Murphy1, Ashley D Harris1,
and Richard G Wise1
1CUBRIC, School of Psychology, Cardiff
University, Cardiff, United Kingdom
By administering CO2 at two different levels, we show
that calibrated BOLD techniques perform similarly in
baseline conditions and at altered baseline CBF levels
that simulate drug or disease effects on baseline brain
physiology. We combined the hypercapnic challenge and
task scans of calibrated BOLD techniques into a single
acquisition. A 4mmHg increase in CO2 at baseline and
elevated CBF levels yields similar estimates of
task-related CMRO2 change. Verifying the performance of
calibrated approaches at modified CBF levels renders
calibrated BOLD techniques more pertinent to a clinical
setting.
|
2197. |
The relationship between
GABA concentrations and cerebral hemodynamics is spatially
heterogeneous ![](poster.gif)
Yi-Ching Lynn Ho1, Jakob Udby Blicher1,
Christopher Bailey1, Torben Ellegaard Lund1,
Jamie Near2, Kim Vang3, Arne
Møller3, and Leif Østergaard1
1Center for Functionally Integrative
Neuroscience (CFIN), Aarhus University, Aarhus, Denmark, 2FMRIB,
Oxford University, Oxford, United Kingdom, 3PET
Center, Aarhus University, Aarhus, Denmark
The influence of baseline GABA on hemodynamics is a
current topic of interest, with a few studies showing
correlations of GABA with BOLD and hemodynamic metrics,
e.g. baseline CBF. In our study, we found that the
GABA-BOLD correlations appear to depend on the area
under investigation. Furthermore, in areas showing
significant correlations, parallel changes in PET-CBF do
not seem to contribute to the relationship. A simple,
linear, mechanistic relationship between GABA
concentrations and hemodynamics may not exist.
|
2198. |
Investigation of fMRI
Induced Resonance Frequency Shifts at 7T
Marta Bianciardi1,2, Peter van Gelderen1,
and Jeff H Duyn1
1Advanced MRI Section, LFMI, NINDS, National
Institutes of Health, Bethesda, MD, United States, 2A.A.
Martinos Center for Biomedical Imaging, Department of
Radiology, Massachusetts General Hospital, Charlestown,
MA, United States
Resonance frequency shifts observed from phase signals
in gradient echo fMRI may provide information
complementary to magnitude signals. However, because of
confounding effects of instrumental and physiological
noise, these signals are difficult to detect and rarely
used. We demonstrate that optimized pre-processing
improves detection of task-evoked and spontaneous
changes in phase signals over large areas of the cortex.
Comparison with magnitude data suggests that the
observed phase signal originate from neuronal activity
and represent susceptibility changes in pial and
intracortical veins. They therefore provide
complementary information to magnitude signals.
|
2199. |
An Absolute Quantification
Method for Pharmacological MRI ![](poster.gif)
Yun-Hsuan Lin1, Kai-Ling Lu1,
Chin-Tien Lu1, Yi-Jui Liu2, and
Fu-Nien Wang1
1Department of Biomedical Engineering and
Environmental Sciences, National Tsing Hua University,
Hsinchu, Taiwan, 2Department
of Automatic Control Engineering, Feng Chia University,
Taichung, Taiwan
Absolute quantification of phMRI could benefit
inter-subject comparison and longitudinal follow-up. In
this study, we combined a modified Vascular-Space
Occupancy (VASO) method and the phMRI technique to
acquire high-resolution multi-slice absolute
quantification of cerebral blood volume (CBV), and
applied for methamphetamine (mAMPH) challenged phMRI on
a rat model. We used single slice IR-RARE sequence to
calculate absolute CBV by the VASO method with Gd-DTPA
administration. Short TR as 1600ms was used to reduced
the tissue interference. Then, multislice relative CBV
maps calculated by the pre- and post-MION images were
converted to absolute values according to the overlapped
slice.
|
2200. |
Direct Experimental
Evidence of the Two Extravascular Compartments Contribution
to The BOLD Signal ![](poster.gif)
Xiaoqi Wang1, Alexander L Sukstanskii2,
and Dmitriy A Yablonskiy1,2
1Department of Physics, Washington University
in St. Louis, St. Louis, Missouri, United States, 2Department
of Radiology, Washington University in St. Louis, St.
Louis, Missouri, United States
Recently introduced qBOLD technique allows quantitative
estimate of brain tissue hemodynamic parameters such as
deoxygenated blood volume and oxygen extraction
fraction. The technique is based on a two extravascular
compartment model of MR signal (intra- and
extra-cellular) in the presence of blood vessel network
and a gradient echo sampling of spin echo (GESSE)
sequence for data acquisition. At the same time numerous
publications treat BOLD signal in the framework of a
single compartment model which can introduce bias if
quantitative results are needed. In this work we present
direct experimental evidence supporting two
extravascular compartments contribution to the BOLD
signal.
|
2201. |
Estimation of functional
changes in blood oxygenation level in large veins from BOLD
frequency shift and susceptibility maps
Marta Bianciardi1,2, Peter van Gelderen1,
and Jeff H Duyn1
1Advanced MRI Section, LFMI, NINDS, National
Institutes of Health, Bethesda, MD, United States, 2A.A.
Martinos Center for Biomedical Imaging, Department of
Radiology, Massachusetts General Hospital, Charlestown,
MA, United States
Blood fractional oxygen saturation is an indicator of
oxygen delivery and metabolism, and may be used to
report tissue viability and function. Current methods
that estimate the blood fractional oxygen saturation
rely on the use of sophisticated fMRI sequences and
modeling. We demonstrate the feasibility of estimating
the functional change in blood fractional oxygen
saturation in large veins during task performance by
analyzing the phase signal in gradient-echo fMRI. With
activation, fractional oxygen saturation in the sagittal
sinus was found to increase by 0.05 which is close to
literature estimates.
|
2202. |
Direct Imaging of Distinct
Vascular Elements Detected by BOLD and Iron Oxide Based
Blood Volume Using High Resolution fMRI of the Rodent
Whisker Barrel
Xin Yu1, Benjamin Porter1, Stephen
Dodd1, Afonso Silva1, and Alan
Koretsky1
1NINDS, NIH, Bethesda, MD, United States
Direct characterization of the intracortical changes in
vascular elements eliciting BOLD and CBV remains
challenging. We measured BOLD and iron oxide based CBV
in layer IV/V of the barrel cortex after whisker pad
stimulation at high temporal (100msec) and spatial
resolutions (150 x150µm) using EPI and fast
gradient-echo MRI. Low intensity EPI voxels corresponded
to activated BOLD voxels and were attributed to venules.
Voxels activated using BOLD were non-overlapping with
CBV voxels. Fast activations (<500msec) and distinct
locations from BOLD voxels led us to attribute these CBV
voxels primarily to penetrating arterioles known to
vasodilate during increased neural activity.
|
2203. |
Influence of orientation
of the draining vein in fMRI ![](poster.gif)
Toru Yamamoto1, and Hiroharu Kubota2
1Faculty of Health Sciences, Hokkaido
University, Sapporo, Hokkaido, Japan, 2Graduate
School of Health Sciences, Hokkaido University, Sapporo,
Hokkaido, Japan
Conventional fMRI involving gradient-echo EPI is mainly
influenced by the magnetic distortion around the
draining vein from the activation area. This distortion
depends on the angle between the draining vein and the
static magnetic field in MRI (Į). To investigate how
the activation area is influenced by the angle between
the draining vein and the static magnetic field, we
performed the same fMRI study for different head
positions in an RF coil by tilting the volunteerfs
head. We found that the activation area, especially the
position of the largest signal increase, shifted
superiorly along the draining vein when Į increased.
|
2204.
![](MAGNA25.jpg) |
Assessment of the
linearity of the R2* dependence on blood oxygenation and
measurement of venous CBV using hyperoxia at 7T
Paula L. Croal1, Ian D. Driver1,
Emma L. Hall1, Susan T. Francis1,
and Penny A. Gowland1
1Sir Peter Mansfield MR Centre, University of
Nottingham, Nottingham, Nottinghamshire, United Kingdom
The linearity of R2* with blood oxygenation is a
critical assumption in most models of the BOLD signal,
and in the measurement of venous cerebral blood volume (vCBV)
using hyperoxia. We used isocapnic hyperoxic to test the
linearity of R2* in grey matter across a dynamic range
of precisely targeted PETO2 levels. A strong linear
relationship was found between oxygenation and R2*,
allowing calculation of GM vCBV (1.97%). The advantage
of this method over previous methods of measuring vCBV
using hyperoxia is that it does not assume that the
relaxivity of the oxygen is the same in the vein and
tissue.
|
2205. |
Systematic evaluation of
BOLD fMRI phase changes at 7 Tesla ![](poster.gif)
Katja Neumann1, Myung-Ho In1, and
Oliver Speck1
1Biomedical Magnetic Resonance,
Otto-von-Guericke-University, Magdeburg, Germany
Functional magnetic resonance (fMRI) phase images of
motor and visual stimulation and a breath hold condition
obtained at 7 Tesla were processed using a stable phase
preserving reconstruction method and analyzed using
general linear model and independent component analysis.
Phase changes upon activations have shown a comparable
sensitivity as magnitude data. Temporally correlated
magnitude and phase time courses of independent
components were observed for motor stimulation;
temporally anti-correlated time courses were observed
for independent components of visual stimulation data.
fMRI phase images may provide complementary information
about spatial localization of brain activation and may
also increase the detection sensitivity.
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