TRADITIONAL POSTER - ismrm

Poster Sessions
1366. Volumetric, 3D Velocity Encoded Valve Imaging with Radial Undersampling
Steven R. Kecskemeti 1 , Kevin Johnson 1 , Oliver Wieben 1
1 Medical Physics, University of Wisconsin, Maidson, WI, United States
The application of PC to cardiac valve imaging offers unique challenges. With the valve location changing as much as 30mm within the cardiac cycle, 2D
single directional PC exams may miss the intended location. An attractive alternative is 3D PC covering a modest slab, with three directional velocity
encoding [1]. However, current use is hampered by long scantimes necessary to achieve the high spatial and temporal resolution required for valve
imaging. A 3D hybrid radial k-space acquisition allows both the mitral and tricuspid or the pulmonary and aortic valves to be imaged in a single scan
within a reasonable time.
1367. Inline Magnitude of Velocity Calculation for Phase Contrast MRA Improves Cardiac Valvular
Assessment
Philip Anthony Hodnett 1,2 , Jeremy D. Collins 3 , Timothy Scanlon, Amir H. Davarpanah, Peter Weale 4 , Sven
Zuehlsdorff 4 , James C. Carr, Chris Glielmi 4
1 Department of Cardiovascular Imaging, Northwestern University, Chicago, IL, United States; 2 Northshore University HealthCare
System, Chicago, IL, United States; 3 Northwestern University, United States; 4 Siemens Healthcare, MR Research and Development,
Chicago, IL
Background: Standard phase contrast MRI (PC-MRI) has potential sources for error when used in assessment of cardiac valvular pathology. We propose a
new directionally independent tool for peak velocity evaluation Methods:The technique employs a phase contrast sequence with three flow encoding
directions and one flow compensated reference. Phase difference images between between each flow encoded and the flow compensated images were
quantified for directional velocity Results: The root sum of square of the 3D encoded data is computed inline and displayed in a magnitude of velocity
dataset for each patient. We compared standard Throughplane phase contrast MRA and Inline calculation velocity of magnitude to the reference standard
echocardiography. Conclusion:Extracting the magnitude of peak velocity independent of its direction significantly reduces error in peak velocity estimation
(one-tailed t-test:p