Fast Measurements of Flow Through Mitral Regurgitant Orifices With Magnetic Resonance Phase Velocity MappingAnnals of Biomedical Engineering
AbstractMagnetic-resonance (MR) phase velocity mapping (PVM) shows promise in measuring the mitral regurgitant volume. However, in its conventional nonsegmented form, MR-PVM is slow and impractical for clinical use. The aim of this study was to evaluate the accuracy of rapid, segmented k-spaceMR-PVM in quantifying the mitral regurgitant flow through a control volume (CV) method. Two segmented MR-PVM schemes, one with seven (seg-7) and one with nine (seg-9) lines per segment, were evaluated in acrylic regurgitant mitral valve models under steady and pulsatile flow. A nonsegmented (nonseg) MR-PVM acquisition was also performed for reference. The segmented acquisitions were considerably faster (min) than the nonsegmented (>45 min). The regurgitant flow rates and volumes measured with segmented MR-PVM agreed closely with those measured with nonsegmented MR-PVM (differences 0.05), when the CV was large enough to exclude the region of flow acceleration and aliasing from its boundaries. The regurgitant orifice shape (circular vs. slit-like) and the presence of aortic outflow did not significantly affect the accuracy of the results under both steady and pulsatile flow (p>0.05). This study shows that segmented k-space MR-PVM canaccurately quantify the flow through regurgitant orifices using the CV method and demonstrates great clinical potential.
Publisher's StatementThe final publication is available at Springer via http://dx.doi.org/10.1007/s10439-004-7815-4
Citation InformationZhang, H., Halliburton, S. S., White, R. D., , & Chatzimavroudis, G. P. (2004). Fast Measurements of Flow through Mitral Regurgitant Orifices with Magnetic Resonance Phase Velocity Mapping. Annals of Biomedical Engineering, 32(12), 1618 - 1627. doi:10.1007/s10439-004-7815-4