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1 |
0174. |
Gradient-Induced Voltages on 12-lead ECGs during
High-Duty-Cycle MRI Sequences and a Theoretically based
Method to Remove Them ![](play.gif)
HuaLei Zhang1, Zion Tsz ho Tse2,
Charles L. Dumoulin3, Ronald Watkins4,
Wei Wang1, Jay Ward5, Raymond
Kwong1, William Stevenson1, and
Ehud J. Schmidt1
1Brigham and Women's Hospital, Boston, MA,
United States, 2University
of Georgia, Georgia, United States, 3Cincinnati
Children’s Hospital Medical Center, Cincinnati, United
States, 4Stanford
University, CA, United States, 5E-TROLZ,
Inc, Andover, MA, United States
To restore high fidelity 12-lead ECG traces acquired
during high-duty-cycle MR imaging sequences, we
developed techniques to restore ECGs distorted by
gradient-induced voltages. We developed a system
response function which characterized induced voltages
at each channel based on simultaneously recorded
gradient waveforms. We then measured gradient-induced
voltages in volunteers at spectrum and amplitude up to
24 KHz and +/-10Volt, and demonstrated close agreement
between the theoretical and measured gradient-induced
voltages. A rapid training sequence permitted computing
the response function coefficients, followed by
real-time gradient-induced voltage removal during
imaging. The response function coefficients varied by
subject, sequences parameters, and slice orientation.
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2 |
0175.
![](http://ismrm.org/15/program_files/MAGNA25.jpg) |
Automatic detection of inflammatory ‘hotspots’ in abdominal
aortic aneurysms to identify patients at risk of aneurysm
expansion and rupture ![](play.gif)
Yolanda Georgia Koutraki1,2, Chengjia Wang1,3,
Jennifer Robson2, Olivia Mcbride2,
Rachael O. Forsythe2, Tom J. MacGillivray1,
Calum D. Gray1, Keith Goatman3, J.
Camilleri-Brennan2, David E. Newby1,2,
and Scott I. Semple1,2
1Clinical Research Imaging Centre, University
of Edinburgh, Edinburgh, United Kingdom, 2Centre
for Cardiovascular Science, University of Edinburgh,
Edinburgh, United Kingdom, 3Toshiba
Medical Visualization System - Europe, Edinburgh, United
Kingdom
The measurement of the diameter of abdominal aortic
aneurysms (AAA) as a criterion for repair has been
proved to be imperfect, thus new methods are required.
Recently Ultrasmall Superparamagnetic Particles of Iron
Oxide (USPIO) in AAA were shown to identify cellular
inflammation in MRI scans and patients were classified
in 3 groups based on the inflammation patterns. Group 3,
with ‘inflammatory hotspots’ on the aortic wall, was
found to have a 3fold expansion of AAA. The
classification process was manual and thus
time-consuming and prone to inter- and intra-observer
variability. We are suggesting the use of our automated
classification software which has excellent agreement
rates in ‘hotspot’ detection, while it provides a 40
times faster, robust and objective processing, with the
potential of sub-classification of the crucial patient
group.
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3 |
0176. |
In-vivo lipid quantification in carotid plaques using
multi-slice T2 mapping: histological validation ![](play.gif)
Luca Biasiolli1,2, Joshua T Chai1,
Linqing Li3, Ashok Handa4, Peter
Jezzard3, Robin P Choudhury1, and
Matthew D Robson2
1AVIC, Radcliffe Department of Medicine,
University of Oxford, Oxford, United Kingdom, 2OCMR,
Radcliffe Department of Medicine, University of Oxford,
Oxford, United Kingdom, 3FMRIB,
Nuffield Department of Clinical Neurosciences,
University of Oxford, Oxford, United Kingdom, 4Nuffield
Department of Surgical Sciences, University of Oxford,
Oxford, United Kingdom
Quantitative T2 mapping has recently emerged as a
promising alternative to multicontrast MRI for carotid
plaque characterization, as it can measure plaque MR
properties directly on a voxel by voxel basis and
discriminate between the lipid core and the surrounding
fibrous tissue. In this study we have developed and
validated a DANTE-MESE sequence for multi-slice T2
mapping and used it for in-vivo plaque lipid
quantification. We have demonstrated that our method is
strongly correlated with histology and can discriminate
between symptomatic and asymptomatic plaques, and hence
has a lot of potential for clinical application.
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4 |
0177. |
Coronary Endothelial Function Assessment Using Self-Gated
Cardiac Cine MRI with golden angle acquisition and k-t
Sparse SENSE ![](play.gif)
Jerome Yerly1,2, Giulia Ginami1,2,
Giovanna Nordio1,2, and Matthias Stuber1,2
1Department of Radiology, University Hospital
(CHUV) and University of Lausanne (UNIL), Lausanne,
Switzerland, 2Center
for Biomedical Imaging (CIBM), Lausanne, Switzerland
Coronary endothelial function (CEF) can be assessed
non-invasively by measuring the vasodilatation of the
coronary arteries in response to isometric handgrip
exercise using bright blood cine MRI. However, cine MRI
requires an external ECG signal to synchronize the data
acquisition, which can be challenging to obtain in
patients at high field strength. To address this hurdle,
we propose a cardiac self-gated technique that combines
golden angle radial acquisition with k-t sparse SENSE to
reconstruct cardiac cine images without ECG. We
demonstrate that our framework can accurately assess CEF
and provide results equivalent to those of the standard
ECG-gated technique.
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5 |
0178.
![](http://ismrm.org/15/program_files/SUMMA25.jpg) |
Inter-study repeatability of self-gated quantitative
myocardial perfusion MRI ![](play.gif)
Devavrat Likhite1, Promporn Suksaranjit2,
Chris McGann2, Brent Wilson2,
Imran Haider2, Ganesh Adluru1, and
Edward DiBella1
1UCAIR, University of Utah, Salt Lake City,
Utah, United States, 2Division
of Cardiovascular Medicine, Department of Medicine,
University of Utah, Salt Lake City, Utah, United States
Dynamic contrast enhanced MRI is maturing as a tool in
contemporary cardiovascular medicine and quantifying
cardiac perfusion is becoming clinically relevant. The
purpose of this study is to understand the inter-study
repeatability of a self-gated approach for
quantification of myocardial perfusion. Nine subjects
underwent self-gated regadenoson rest/stress imaging
twice within 9.5±4.5 days. The systolic images showed
good repeatability of the myocardial perfusion reserve,
with a coefficient of variation similar to published
gated studies.
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6 |
0179. |
Initial Experience in Patients for Highly Accelerated
Free-Breathing Whole-Heart Coronary MRA - permission withheld
Christoph Forman1, Christoph Tillmanns2,
Michael O. Zenge1, and Michaela Schmidt1
1Siemens AG, Healthcare, Imaging and Therapy
Systems, Magnetic Resonance, Erlangen, Germany, 2Diagnostikum
Berlin, Berlin, Germany
3D whole-heart magnetic resonance angiography (CMRA)
with high isotropic resolution allows the assessment of
the complete cardiac anatomy including the coronary
arteries. The highly accelerated data acquisition with
sparse, incoherent sampling enables its integration into
routine clinical examination even with navigator-gating.
In this work, the resulting image quality and diagnostic
performance of sparse CMRA was evaluated in patients and
compared to computed tomography angiography (CTA).
Although CMRA was inferior to CTA, it provides a
promising radiation-free method visualizing congenital
malformations and has great potential for screening,
e.g. to assess the risk of sudden cardiac death.
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7 |
0180. |
Accelerated Four-dimensional, multiphase, steady-state
imaging with Contrast Enhancement (MUSIC) using Parallel
Imaging and Compressed Sensing ![](play.gif)
Ziwu Zhou1, Fei Han1, Stanislas
Rapacchi1, Ihab Ayad2, Isidro
Salusky3, Adam Plotnik1, Paul Finn1,
and Peng Hu1
1Radiology, UCLA, Los Angeles, CA, United
States, 2Anesthesiology,
UCLA, Los Angeles, CA, United States, 3Pediatrics,
UCLA, Los Angeles, CA, United States
In this study, we evaluate the usage of Parallel Imaging
and Compressed Sensing to accelerate a recently proposed
four dimensional, non-breath-hold, multiphase
steady-state imaging technique (MUSIC), in hope to
decrease acquisition time and increase temporal
resolution. Based on initial experience on nine
pediatric patients with congenital heart disease,
accelerated MUSIC has similar image quality with half
acquisition time, compared with original MUSIC. Image
reconstruction is implemented in C/C++ that allows
clinically acceptable reconstruction time, make it
feasible for practical usage.
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8 |
0181.
![](http://ismrm.org/15/program_files/MAGNA25.jpg) |
Dual Agent Relaxivity Cancellation (DARC) Imaging, a Novel
Imaging Method for Dark Blood Post-Contrast Imaging:
Application to MR Lymphangiography ![](play.gif)
Jeffrey H Maki1, Noah Briller1,
Peter C Neligan2, and Gregory J Wilson1
1Radiology, University of Washington,
Seattle, WA, United States, 2Plastic
Surgery, University of Washington, Seattle, WA, United
States
A novel MR imaging method using two contrast agents (one
for enhancement of non-blood-pool tissues, and one for
suppression of blood-pool signal), named Dual Agent
Relaxivity Cancellation (DARC), was developed for the
visualization of lymphatic channels. The MR
lymphangiography technique utilizes the T1 signal
enhancement of intracutaneously injected gadobenate and
the blood-pool T2* signal suppression of intravenously
injected ferumoxytol. When imaged with mDixon using
relatively long TE’s (4-8ms), lymphatic channels are
easily visualized without venous overlay.
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9 |
0182. |
CMR-footprinting: Quantifying tissue parameters with
clinical pulse sequence simulations improves measurement
accuracy - an example with MOLLI T1 mapping ![](play.gif)
Christos G. Xanthis1,2, Sebastian L. Bidhult1,
Georgios Kantasis1,2, Mikael Kanski1,
Einar Heiberg1,3, Håkan Arheden1,
and Anthony H. Aletras1,2
1Cardiac MR group Lund, Dept. of Clinical
Physiology, Lund University, Lund, Skåne, Sweden, 2Department
of Computer Science and Biomedical Informatics,
University of Thessaly, Lamia, Lamia, Greece, 3Department
of Biomedical Engineering, Faculty of Engineering, Lund
University, Lund, Skåne, Sweden
MR simulations have been used in a limited scope in the
past. In this study, we propose CMR-footprinting, a new
method showing how quantitative CMR with clinical pulse
sequences can be improved by comparing the signals
acquired from the MRI scanner to the entire pool of
possible outcomes that are produced by massively
parallel MRI simulations of the identical pulse sequence
for different tissue types. A MOLLI example was used and
CMR-footprinting demonstrated overall T1 accuracy
improvement and good performance even for long T1s with
a zero seconds pause.
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10 |
0183.
![](http://ismrm.org/15/program_files/SUMMA25.jpg) |
Modified Wideband 3D Late Gadolinium Enhancement (LGE) MRI
for Patients with Implantable Cardiac Devices ![](play.gif)
Shams Rashid1, Stanislas Rapacchi1,
Kalyanam Shivkumar1,2, Adam Plotnik1,
J. Paul Finn1,3, and Peng Hu1,3
1Radiological Sciences, University of
California, Los Angeles, Los Angeles, CA, United States, 2UCLA
Cardiac Arrhythmia Center, University of California, Los
Angeles, Los Angeles, CA, United States, 3Biomedical
Physics Inter-Departmental Graduate Program, University
of California, Los Angeles, Los Angeles, CA, United
States
We have modified a 3D LGE sequence for LGE cardiac MRI
of patients with implanted cardiac devices by
implementing a wideband inversion pulse and increasing
the RF excitation pulse bandwidth. We show reduced
hyper-intensity artifacts due to the wideband inversion
pulse. We also show that the conventional 3D LGE
sequence produces artifacts due to slab profile
distortion, which are reduced by increasing the
bandwidth of the RF excitation pulse. We present results
from phantom, volunteer and patient studies.
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11 |
0184.
![](http://ismrm.org/15/program_files/MAGNA25.jpg) |
Black Blood Late Gadolinium Enhancement (BB-LGE) using a
joint T2 Magnetization
Preparation and Inversion Preparation ![](play.gif)
Tamer Basha1, Sébastien Roujol1,
Kraig V. Kissinger1, Beth Goddu1,
Warren J. Manning1,2, and Reza Nezafat1
1Department of Medicine, Beth Israel
Deaconess Medical Center & Harvard Medical School,
Boston, Massachusetts, United States, 2Radiology,
Beth Israel Deaconess Medical Center and Harvard Medical
School, Boston, Massachusetts, United States
Late gadolinium enhancement (LGE) allows depiction of
scar/fibrosis in patients with cardiovascular disease.
An inversion recovery based sequence is commonly used to
achieve suppression of healthy myocardium signal.
However, the blood pool and subendocardial scar
typically have similar signal, making it difficult to
distinguish subendocardial scar. In this work, we
propose a novel pulse sequence that uses an optimized
combination of an inversion pulse and a T2prep
composite pulse to simultaneously null both the healthy
myocardium and blood signals, producing a black-blood
LGE (BB-LGE) image without losing significant
scar-myocardium contrast.
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12 |
0185.
![](http://ismrm.org/15/program_files/SUMMA25.jpg) |
"Squashing the peanut": What it means for in-vivo cardiac
DTI ![](play.gif)
Andrew D Scott1,2, Sonia Nielles-Vallespin1,3,
Pedro Ferreira1,2, Laura-Ann McGill1,2,
Dudley Pennell1,2, and David Firmin1,2
1NIHR Cardiovascular Biomedical Research
Unit, The Royal Brompton Hospital, London, United
Kingdom, 2National
Heart and Lung Institute, Imperial College London,
London, United Kingdom, 3National
Heart, Lung and Blood Institute, National Institutes of
Health, Bethesda, Maryland, United States
The effects of noise have been well described in
neurological DTI, but the specific effects on cardiac
DTI are less understood. We developed cardiac specific
simulations to demonstrate the effects of noise on
parameters derived from cardiac DTI at a range of
b-values. This framework was used to demonstrate the
benefits of averaging the complex rather than magnitude
data. Subsequently, an algorithm for complex averaging
of in-vivo data was developed and tested in a healthy
cohort. FA and MD are over-estimated at low b-values and
under-estimated at high b-values. Complex averaging
reduces under-estimation of MD and FA at high b-values.
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13 |
0186. |
Diffusion-tensor imaging study of myocardial architecture of
Situs Inversus and Situs Solitus mutant mouse hearts ![](play.gif)
Yijen Lin Wu1,2, Yu Chen1, XiaoQin
Liu1, Fang-Cheng Yeh3, T. Kevin
Hitchens4, George C Gabriel1, and
Cecilia Wen Ya Lo1
1Developmental Biology, University of
Pittsburgh, Pittsburgh, PA, United States, 2Rangos
Research Center Imaging Core, Children's Hospital of
Pittsburgh of UPMC, Pittsburgh, PA, United States, 3Psychology,
Carnegie Mellon University, Pittsburgh, PA, United
States, 4Pittsburgh
NMR Center for Biomedical Research, Carnegie Mellon
University, Pittsburgh, PA, United States
Normal human development results in an asymmetrical
arrangement of the organs within the chest and abdomen,
as referred to as Situs Solitus. Situs Inversus, a type
of laterality defect, in which the organs of the chest
and abdomen are arranged in a perfect mirror image
reversal of the normal position. We used DTI to study
the myocardial architecture of Pkd1l1-/- mutant mouse
hearts, with either Situs Solitus or Situs Inversus
phenotypes. Although the Situs Solitus mutant heart
appears phenotypically “normal”, our DTI results show
that it is showing more aberrant myocardial organization
similar to those of Situs Inversus mutant heart.
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14 |
0187.
![](http://ismrm.org/15/program_files/SUMMA25.jpg) |
Mechanical Activation Time Mapping in Heart Failure Patients
with and without Myocardial Scar using Cine DENSE MRI ![](play.gif)
Daniel A Auger1, Sophia X Cui1,
Xiao Chen1, Jeffrey W Holmes1,
Kenneth C Bilchick2, and Frederick H Epstein1,3
1Department of Biomedical Engineering,
University of Virginia, Charlottesville, Virginia,
United States, 2Department
of Medicine, Cardiovascular Medicine, University of
Virginia, Charlottesville, Virginia, United States, 3Department
of Radiology and Medical Imaging, University of
Virginia, Charlottesville, Virginia, United States
The purpose of this study was to use MRI and other
methods to evaluate the relationship between mechanical
and electrical cardiac activation in patients with heart
failure (HF), a wide QRS complex, and the absence or
presence of myocardial scar. Cine DENSE MR strain
imaging methods were used to assess the delay in
mechanical activation time in patients with and without
scar. Results show good correlations between mechanical
and electrical activation times in both patient cohorts.
In patients with scar, the steeper slope of the
regression line may reflect a more complex
electromechanical substrate and altered
electro-mechanical coupling.
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15 |
0188. |
A
Bayesian Approach for Accelerated Phase Contrast MRI ![](play.gif)
Adam Rich1, Lee C. Potter1, Ning
Jin2, Joshua Ash1, Orlando
Simonetti3, and Rizwan Ahmad3
1Electrical and Computer Engineering, The
Ohio State University, Columbus, OH, United States, 2Siemens
Medical Solution, Columbus, OH, United States, 3Davis
Heart and Lung Research Institute, The Ohio State
University, Columbus, OH, United States
Phase Contrast MRI (PC-MRI) offers unique advantages
over Doppler ultrasound for the quantification of
hemodynamics. However, lengthy scan times have limited
the clinical use of PC-MRI. We propose a Bayesian
inference technique to accelerate PC-MRI data
acquisition. The technique exploits the rich structure
inherent to the data across space, time and encodings.
Using 2D PC-MRI data from healthy volunteers,
performance of the technique is examined over a wide
range of acquisition times for prospective and
retrospective under-sampling. The proposed technique
provides an accurate recovery of peak and mean velocity
at accelerate rates of eight or higher with fast
computation.
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16 |
0189. |
Validation of radially undersampled 4D-Flow-MRI in an animal
model of portal hypertension ![](play.gif)
Alex Frydrychowicz1, Alejandro Roldan-Alzate2,
Emily Winslow2, Dan Consigny2,
Camilo Campo2, Utaroh Motosugi2,
Kevin M Johnson2, Christopher J François2,
Oliver Wieben2, and Scott B Reeder2
1Clinic for Radiology and Nuclear Medicine,
University Hospital Schleswig-Hosltein, Campus Lübeck,
Lübeck, Schleswig-Holstein, Germany, 2University
of Wisconsin - Madison, Wisconsin, United States
An animal model of portal hypertension by partial portal
vein ligature was created in seven pigs and evaluated by
4D Flow MRI using PC-VIPR, a radially undersampled
acquisition scheme. During the operative procedure,
vessels were assessed by perivascular ultrasound to
provide an unprecedented in-vivo comparison of 4D Flow
MRI to a reference standard. PHTN was successfully
created, results show a good agreement of US and 4D Flow
MRI using PC-VIPR.
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