16:00 |
0449.
![](http://www.ismrm.org/15/program_files/SUMMA25.jpg) |
Correction of background
phase offsets in phase-contrast MRI using concurrent
magnetic field monitoring. ![](play.gif)
Daniel Giese1,2, Bertram Wilm2,3,
Julia Busch2, David Maintz1,
Christoph Barmet2,3, Klaas Pruessmann2,
and Sebastian Kozerke2
1Radiology, University Hospital Cologne,
Cologne, Germany, 2Institute
for Biomedical Engineering, University and ETH Zurich,
Zurich, Switzerland, 3Skope
Magnetic Resonance Technologies, Zurich, Switzerland
Concurrent magnetic field monitoring is used to analyze
and correct for eddy-current related background phase
offsets in phase-contrast MRI. It is demonstrated that
3rd order correction results in residual background
offsets of less than 0.6 cm/s. Using simultaneous
acquisition of field monitoring and imaging data,
temperature dependent changes in background phase
offsets are inherently captured and corrected for.
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16:12 |
0450.
![](http://www.ismrm.org/15/program_files/SUMMA25.jpg) |
Reproducibility of
Phase-Contrast MRI in the Coronary Artery: Towards
Noninvasive Pressure Gradient Measurement and Quantification
of Fractional Flow Reserve ![](play.gif)
Zixin Deng1,2, Yang Qi2, Xiaoming
Bi3, Zhaoyang Fan2, and Debiao Li1,2
1Bioengineering, University of California,
Los Angeles, Los Angeles, California, United States, 2Biomedical
Imaging Research Institute (BIRI), Cedars-Sinai Medical
Center, Los Angeles, California, United States, 3R&D,
Siemens Healthcare, Los Angeles, California, United
States
Fractional Flow Reserve (FFR) invasively evaluates the
functional severity of an intermediate stenosis by
measuring the stenotic pressure drop via
catheterization. Noninvasive pressure measurements using
PC-MRI and Navier-Stokes equations have been shown in
the aorta, carotid and renal arteries. In this study,
the feasibility and reproducibility of PC-MRI and
noninvasive pressure calculations were evaluated in the
coronary arteries to establish the robustness of
noninvasive FFR measurement using MRI. Excellent
correlations were observed in the through-plane and
slightly lower in the in-plane velocities between the
repeated acquisitions. The noninvasive pressure values
in healthy subjects were near zero, as expected.
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16:24 |
0451.
![](http://www.ismrm.org/15/program_files/SUMMA25.jpg) |
Soft-gated accelerated
Cartesian 4D flow imaging with intrinsic navigation
![](play.gif)
Joseph Y Cheng1,2, Marcus T Alley2,
Tao Zhang1,2, Peng Lai3, Jonathan
I Tamir4, Martin Uecker4, John M
Pauly1, Michael Lustig4, and
Shreyas S Vasanawala2
1Electrical Engineering, Stanford University,
Stanford, CA, United States, 2Radiology,
Stanford University, Stanford, CA, United States, 3Global
Applied Science Laboratory, GE Healthcare, Menlo Park,
CA, United States, 4Electrical
Engineering and Computer Sciences, University of
California, Berkeley, CA, United States
Time-resolved phase contrast MRI (4D flow) can quantify
cardiac function and flow. The technique may even permit
complex anatomical assessment, thus comprising a
comprehensive exam in a single scan. Unfortunately,
artifacts from respiratory motion compromise this
ability. Therefore, we developed a simple method to
measure motion using readily available navigation
information from the flow encoding gradients. We
incorporated and modified a variable-density sampling
and radial view-ordering scheme to facilitate motion
correction and compressed sensing methods. Lastly, we
integrated soft-gating to the compressed sensing and
parallel imaging reconstruction. These
motion-compensation approaches help improve the
reliability and resolution of 4D flow imaging.
|
16:36 |
0452.
![](http://www.ismrm.org/15/program_files/SUMMA25.jpg) |
Aortic stiffness, cardiac
energetic, systolic and diastolic function in healthy
ageing. ![](play.gif)
Jehill D Parikh1, Kieren G Hollingsworth1,
Andrew M Blamire1, and Guy MacGowan2
1Newcastle Magnetic Resonance Centre,
Newcastle University, Newcastle upon Tyne, Tyne and
Wear, United Kingdom, 2Cardiology,
Freeman Hospital, Newcastle Upon Tyne, Tyne and Wear,
United Kingdom
Aorta rapidly expands during a ventricular contraction
accommodating the majority (50% or more) of the stroke
volume. Aortic stiffness increases with age, and is
regarded as an independent risk factor in the
development of cardiovascular disease. Additionally,
normal ageing is characterized by age-related diastolic
dysfunction, altered systolic strains and impaired
myocardial energetics. In this study we explore
associations between age-related increase in aortic
stiffness and cardiac energetics and left ventricular
function. Such associations may provide important
insights into how normal ageing affects the heart, which
may allow development of potential treatments to
attenuate this process.
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16:48 |
0453.
![](http://www.ismrm.org/15/program_files/SUMMA25.jpg) |
3D quantification of
Vorticity and Helicity from 4D flow data using finite
element interpolations ![](play.gif)
Julio Sotelo1,2, Jesus Urbina1,3,
Israel Valverde4,5, Cristian Tejos1,
Pablo Irarrazaval1, Daniel E. Hurtado2,6,
and Sergio Uribe1,3
1Biomedical Imaging Center, Electrical
Engineering Department, Pontificia Universidad Catolica
de Chile, Santiago, RM, Chile, 2Structural
and Geotechnical Engineering Departement, Pontificia
Universidad Catolica de Chile, Santiago, RM, Chile, 3Radiology
Department, School of Medicine, Pontificia Universidad
Catolica de Chile, Santiago, Chile, 4Pediatric
Cardiology Unit, Hospital Virgen del Rocio, Seville,
Spain, 5Cardiovascular
Pathology Unit, Institute of Biomedicine of Seville
(IBIS), Hospital Virgen del Rocio, Seville, Spain, 6Biomedical
Engineering Group, Pontificia Universidad Catolica de
Chile, Santiago, Chile
Several methods have been proposed to analyze
hemodynamic parameters from 4D flow data, including
vorticity and helicity. However the analysis is usually
qualitative and performed in reformatted 2D planes. In
this work we propose a novel method that integrates
advanced image processing strategies and computational
techniques based on finite element interpolations to
obtain a 3D quantitative map of vorticity, helicity
density and relativity helicity density derived from 4D
flow data sets obtained from volunteers and patients.
|
17:00 |
0454.
![](http://www.ismrm.org/15/program_files/SUMMA25.jpg) |
Reproducibility of Advanced
Velocity and Wall Shear Stress Quantification Techniques
Derived From 4D Flow MRI in the Pathological Aorta ![](play.gif)
Pim van Ooij1, Wouter V Potters1,
Jeremy D Collins2, James C Carr2,
S Chris Malaisrie3, Patrick M McCarthy4,
Michael Markl2, and Alex J Barker2
1Radiology, Academic Medical Center,
Amsterdam, Netherlands, 2Radiology,
Northwestern University, Chicago, IL, United States, 3Medicine-Cardiology,
Northwestern University, Chicago, IL, United States, 4Division
of Cardiac Surgery, Northwestern University, Chicago,
IL, United States
Recently a technique was developed to visualize
patient-specific abnormal aortic velocity and wall shear
stress (WSS) for guidance in tissue resection surgery
for BAV disease. In this study, the reproducibility of
the technique is investigated by comparing abnormal
velocity and WSS of baseline and follow-up (separated by
appr. a year) 4D flow MRI in 24 BAV patients and 15
tricuspid aortic valves and aortic dilatation (TAV+D).
No significant differences were found in aortic
diameter, peak velocity or abnormal velocity and WSS.
Therefore, the technique is stable.
|
17:12 |
0455.
![](http://www.ismrm.org/15/program_files/MAGNA25.jpg) |
4D Flow based
Characterization of Aortic Morphometry and Flow Parameters:
Impact of Age, Aortic Dilatation and Valve Morphology ![](play.gif)
Julio Garcia1, Alex J Barker1, Ian
Murphy1, Kelly B Jarvis1, Alex L
Powell1, Susanne Schnell1, Jeremy
Collins1, James Carr1, S Chris
Malaisrie2, and Michael Markl1,3
1Radiology, Northwestern University, Chicago,
Illinois, United States, 2Division
of Cardiothoracic Surgery, Northwestern University,
Chicago, Illinois, United States, 3Biomedical
Engineering, Northwestern University, Evanston,
Illinois, United States
Aortic diameter and peak velocity are important metrics
for the characterization of aortic disease. However,
these parameters are typically evaluated at selected
locations along the aorta and are thus subject to
observer variability and may miss the true maximum
aortic diameter or velocity. The purpose of this study
was to apply volumetric 4D flow MRI for the simultaneous
assessment of aorta morphometry and flow parameters
along the entire volume of the thoracic aorta in
patients with aortic dilation.
|
17:24 |
0456. |
Longitudinal Monitoring of
Hepatic Blood Flow in patients with portal hypertension
before and after TIPS implantation with 4D Flow MRI ![](play.gif)
Peter Bannas1,2, Alejandro Roldán-Alzate1,
Kevin M Johnson3, Michael A Woods1,
Utaroh Motosugi1, Oliver Wieben3,
Scott B Reeder1,3, and Harald Kramer1,4
1Radiology, University of Wisconsin-Madison,
Madison, WI, United States, 2Radiology,
University Medical Center Hamburg-Eppendorf, Hamburg,
Hamburg, Germany, 3Medical
Physics, University of Wisconsin-Madison, WI, United
States, 4Radiology,
Ludwig-Maximilians-University Hospital, Munich, Bavaria,
Germany
Transjugular intrahepatic portosystemic shunt (TIPS) is
non-surgical method of portal decompression to treat
major complications of portal hypertension. Currently,
the combination of Doppler ultrasound and invasive
portosystemic pressure measurements are applied to
monitor patients before and after TIPS placement. An
alternative operator-independent and non-invasive
technique would be highly desirable. In this study we
demonstrate the feasibility of 4D-flow MRI for
qualitative and quantitative analyses of hepatic blood
flow before and then 2 and 12 weeks after TIPS
placement. 4D flow MRI is feasible for longitudinal
hemodynamic monitoring of the blood flow in the portal
vein and the TIPS stent.
|
17:36 |
0457. |
Quantitative assessment of
splenic hemodynamics at 4D flow MRI in the evaluation of
thrombocytopenia: A pilot study in cirrhotic patients with
portal hypertension ![](play.gif)
Jeremy Douglas Collins1, Jad Bou Ayache2,
Edouard Semaan3, Riad Salem4,
James Christian Carr3, Michael Markl3,
and Zoran Stankovic5
1Radiology, Northwestern University, Chicago,
IL, United States, 2Radiology,
Icahn School of Medicine at Mount Sinai, New York,
United States, 3Northwestern
University, Illinois, United States, 4Radiology,
Northwestern University, Illinois, United States, 5Radiology,
University Hospital, Freiberg, Germany
There is a clinical need for a non-invasive diagnostic
test to assess spleen function. Quantitative splenic
hemodynamics, assessed using non-contrast 4D flow MRI,
demonstrate differences between patients with severe and
mild thrombocytopenia and may be useful to distinguish
patients with hypersplenism associated thrombocytopenia
from those with thrombopoetin deficiency.
|
17:48 |
0458. |
Highly Accelerated
Intracranial 4D Flow MRI with CIRcular Cartesian
UnderSampling (CIRCUS) ![](play.gif)
Jing Liu1, Farshid Faraji1, Sarah
Kefayati1, Henrik Haraldsson1, and
David Saloner1,2
1Radiology and Biomedical Imaging, University
of California San Francisco, San Francisco, CA, United
States, 2Radiology
Service, VA Medical Center, San Francisco, CA, United
States
An effective k-space undersampling scheme for 3D
Cartesian acquisition combined with compressed sensing
and parallel imaging has successfully been implemented
and applied to intracranial 4D flow MRI. Our preliminary
results demonstrated that the proposed approach achieved
high image quality and accurate velocity imaging with
largely accelerated acquisition (R=7).
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