ISMRM 24th Annual Meeting & Exhibition • 07-13 May 2016 • Singapore

Scientific Session: Velocity & Flow Quantification

Tuesday, May 10, 2016
Room 334-336
10:00 - 12:00
Moderators: Jeremy Collins, Oliver Wieben

4D flow MRI-Derived Hemodynamic Atlases of the Left Ventricle with Hypertrophic Cardiomyopathy Demonstrate Abnormally Elevated Blood Flow Velocities
Pim van Ooij1, Alex J Barker2, Henk A Marquering3, Gustav J Strijkers3, James C Carr2, Michael Markl2,4, and Aart J Nederveen5
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Radiology, Northwestern University, Chicago, IL, United States, 3Biomedical Engineering & Physics, Academic Medical Center, Amsterdam, Netherlands, 4Biomedical Engineering, Northwestern University, Chicago, IL, United States, 5Academic Medical Center, Amsterdam, Netherlands
Altered hemodynamics in the left ventricle (LV) may contribute to heart failure in hypertrophic cardiomyopathy (HCM). The aim of this was study was to employ 4D flow MRI to identify regions with altered velocity in HCM patients based on the concept of 'LV flow heat maps' comparing velocity fields in HCM patients with an atlas derived from healthy controls. In the ejection phase, abnormally elevated velocity was found in the LV outflow tract, whereas the filling phase showed elevated velocity in the LV apex.

Characterization of aortic blood flow after aortic valve replacement by 4D flow MRI
Alex S Hong1, Emilie Bollache1, Pim van Ooij1, James C Carr1, Alex J Barker1, Jeremy D Collins1, and Michael Markl2
1Department of Radiology, Northwestern University, Chicago, IL, United States, 2Department of Radiology, Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States
Aortic valve replacement (AVR) is an effective surgical approach to treating aortic valvular disease, but it is unclear if and what type of prosthesis can fully reproduce physiologically normal flow characteristic of a native aortic valve. We utilized 4D flow MRI to systematically compare blood flow in the thoracic aorta in post-AVR (bioprosthetic vs. mechanical) patients and healthy controls. Both bioprosthetic and mechanical valves were found to produce higher peak systolic flow velocities and peak wall shear stress in the ascending aorta than native valves, demonstrating the presence of significant changes in aortic blood flow in AVR patients.

Pressure Gradient Measurement in the Coronary Artery Using Phase Contrast (PC)-MRI: Initial Patient Results Towards Noninvasive Quantification of Fractional Flow Reserve
Zixin Deng1,2, Sangeun Lee3, Zhaoyang Fan1, Christopher Nguyen1, Iksung Cho3, Qi Yang1, Xiaoming Bi4, Byoung-Wook Choi5, Jung-Sun Kim3, Daniel Berman1, Hyuk-Jae Chang3, and Debiao Li1
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, 3Cardiology, Severance Hospital, Yonsei Univeristy College of Medicine, Seoul, Korea, Republic of, 4R&D, Siemens Healthcare, Los Angeles, CA, United States, 5Radiology, Severance Hospital, Yonsei Univeristy College of Medicine, Seoul, Korea, Republic of
Fractional flow reserve is an invasive diagnostic tool to evaluate the functional significance of a coronary stenosis by quantifyin­g the pressure gradient (ΔP) across the stenosis. We proposed a non-invasive technique to derive ΔP using Phase-contrast (PC)-MRI in conjunction with the Navier-Stokes equations (ΔPMR). Excellent correlation was observed between derived ΔPMR and measure ΔP from a pressure transducer in a small caliber phantom model. A significant increase in ΔPMR was seen in the patient group vs. healthy controls. Preliminary results suggested that noninvasive quantification of ΔPMR in coronary arteries is feasible. 

Cine Phase Contrast Simultaneous Multi-Slice imaging of blood flow and CSF motion.
David A Feinberg1,2, Alexander Beckett1, An T Vu1,2, and Liyong Chen2
1Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States, 2Advanced MRI Technologies, Sebastopol, CA, United States
The purpose was to develop and evaluate a novel approach to MR phase imaging of blood flow and CSF flow by combining cine phase contrast (cine-PC) with simultaneous multi-slice (SMS) technique to measure velocity in several slice planes simultaneously. Comparisons were made between SMS 2-4 and conventional single-slice 2D cine-PC GE imaging. The velocity curves measured in internal carotid (ICA) and vertebral arteries and jugular veins and aqueductal CSF were similar between SMS and conventional single-slice cine-PC. In ICA correlations (R=0.92-0.98) in 6 subjects. This new ability for simultaneous cross-sectional hemodynamic quantification may be useful for medical diagnoses.  

Vortex-ring mixing as a measure of diastolic function of the human heart: phantom validation and initial observations in healthy volunteers and patients with heart failure
Johannes Töger1,2, Mikael Kanski1, Per M Arvidsson1, Marcus Carlsson1, Sándor J Kovács3, Rasmus Borgquist4, Johan Revstedt5, Gustaf Söderlind2, Hĺkan Arheden1, and Einar Heiberg1,2,6
1Department of Clinical Physiology, Lund University Hospital, Lund University, Lund, Sweden, 2Department of Numerical Analysis, Centre for Mathematical Sciences, Lund University, Lund, Sweden, 3Department of Internal Medicine, Washington University School of Medicine, St Louis, MO, United States, 4Department of Arrhythmias, Lund University Hospital, Lund University, Lund, Sweden, 5Department of Energy Sciences, Lund University, Faculty of Engineering, Lund, Sweden, 6Department of Biomedical Engineering, Lund University, Faculty of Engineering, Lund, Sweden
Diastolic dysfunction of the left ventricle (LV) of the heart is a severe condition associated with poor prognosis. However, objective and reproducible assessment of diastolic function remains a challenge. We propose a new method using 4D flow MR by quantification of blood mixing within the LV diastolic vortex-ring. Phantom validation showed fair agreement between 4D flow MR and planar laser-induced fluorescence (PLIF). Quantitative vortex-ring mixing differs between healthy controls and patients with heart failure, which demonstrates its potential as a marker of diastolic dysfunction.

Dynamic assessment of atrioventricular junction (AVJ) based on radial long-axis cine cardiac MR imaging
Shuang Leng1, Shuo Zhang2, Xiaodan Zhao1, Baoru Leong1, Yiying Han1, Yasutomo Katsumata3, Stuart Cook1,4, Ru San Tan1,4, and Liang Zhong1,4
1National Heart Centre Singapore, Singapore, Singapore, 2Philips Healthcare Singapore, Singapore, Singapore, 3Philips Healthcare Japan, Tokyo, Japan, 4Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
We have developed a semi-automatic tracking system of atrioventricular junction (AVJ) deformation with two-, three-, and four-chamber cardiovascular magnetic resonance (CMR) long-axis images 1. In this study, we applied the feature-tracking technique in 18 radial rotational long-axis cine CMR planes and evaluated the motion of 36 evenly located AVJ points. Results have shown that 1) the obtained average AVJ velocities (Sm, Em and Am) and maximal displacements are independent of the number of AVJ points selected, and 2) the routinely acquired CMR imaging generated in clinical practice are sufficient enough for dynamic assessment of AVJ deformation.

3D Blood Flow Velocity Distribution in the Normal Aorta: Effect of Age and Gender Across 101 Subjects
Julio Garcia1, Roel L.F. van der Palen2, Alex J. Barker1, Jeremy D. Collins1, James C. Carr1, Joshua Robinson3, Cynthia Rigsby3, and Michael Markl1,4
1Radiology, Northwestern University, Chicago, IL, United States, 2Pediatric Cardiology, Leiden University Medical Center, Leiden, Netherlands, 3Department of Medical Imaging, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, United States, 4Biomedical Engineering, Northwestern University, Evanston, IL, United States
The systematic characterization of effects in aortic disease patients and healthy controls is important to improve disease diagnosis. 4D flow MRI can be applied for the analysis of altered hemodynamics in cardiovascular disease. However, data analysis can be time consuming and often data are not fully utilized by analysis based on 2D planes. This study aimed to systematically apply flow distribution analysis in the entire volume of the aorta to establish normative reference values across a wide age range from pediatric to adult subjects.

High Quality Preclinical 4D-Flow Phase Contrast Imaging
Moritz Braig1, Jochen Leupold1, Ko Cheng-Wen2, Marius Menza1, Juergen Hennig1, Jan Korvink3, and Dominik von Elverfeldt1
1University Medical Center Freiburg, Freiburg, Germany, 2Dept. Computer Science and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan, 3Institute of Microstructure Technology, Karlsruhe Institute of Technology, Karlsruhe, Germany
So far preclinical 4D-Flow MRI has not been able to deliver an analysis of complex flow due to low resolution. The presented framework and improvements allow high quality data acquisitions with a reduced measurement time and the possibility to visualize regional flow abnormalities. An automatic magnitude segmentation in every timeframe combines anatomic information with the underlying blood flow showing even small vessels. It will draw new conclusions in mouse models of cardiovascular diseases as a valuable tool for preclinical researchers.

Ultra-High-Dimensional Flow Imaging (N-D Flow)
Joseph Y. Cheng1, Tao Zhang1, Marcus T. Alley1, Michael Lustig2, John M. Pauly3, and Shreyas S. Vasanawala1
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering & Computer Sciences, University of California, Berkeley, CA, United States, 3Electrical Engineering, Stanford University, Stanford, CA, United States
Volumetric cardiac-resolved flow imaging (4D flow) can enable the assessment of flow, function, and anatomy from a single sequence. Here, 4D flow is extended to higher dimensional space as N-D flow. By resolving different dynamics such as respiration or contrast enhancement, more diagnostic information can be extracted for a single-sequence protocol. Furthermore, this potentially improves image quality and quantification accuracy. N-D flow is enabled by a compressed-sensing and parallel imaging based acquisition and reconstruction. The feasibility of this approach is demonstrated for pediatric imaging. 

In vitro validation of Cartesian 4D flow mapping using patient-specific 3D printed total cavo-pulmonary connection models
Zachary Borden1, Peng Lai2, Ann Shimakawa2, Alejandro Roldan-Alzate1,3, and Christopher J Francois1
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2GE Healthcare, Menlo Park, CA, United States, 3Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, United States
Congenital heart disease is a common disease process which benefits from MRI 4D flow analysis. In a total cavo-pulmonary connection model, Cartesion 4D Flow mapping using k-t acceleration and variable density signal averaging correlates well with US flow probe data and 2D PC measurements. The improved post processing efficiency of Cartesian acquisition may allow more widespread adoption of 4D flow technology for analyzing congenital heart disease.

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