The modality of MRI has the potential to give a wealth of information concerning vascular pathology, including definition of intra-luminal space and vessel wall morphology, flow shear at the vessel wall, plaque localization and characterization, and flow rates and patterns. These data are easily registered to soft tissue MR images taken during the same examination. Phase Contrast-MRA (PC-MRA), in particular, can (1) produce qualitative images of intravascular space, and (2) provide quantitative flow velocities. Despite this potential, PC-MRA is not regularly used clinically. Long imaging times are one important challenge to phase contrast methods, as is the signal loss from disordered flow in the presence of the flow-encoding gradient.This grant will produce "next-generation" PC-MRA methodology. Current methods for PC-MRA will be greatly enhanced by (1) using a novel, rapid, high signal-to-noise-ratio (SNR) data acquisition strategy, with (2) a new scheme for flow encoding which further increases SNR, and (3) integration and refinement of reconstruction methods, such as non-Cartesian parallel imaging, all of which will produce high resolution, high SNR, accurate measures of blood flow as well as easily calculated, repeatable estimates of wall shear stress (WSS). Both 3D (data averaged over the cardiac cycle) and 4D (data parsed over the cardiac cycle) versions will be implemented. The work in this grant will develop these methods and include initial quantitative assessment of performance. The applications will be focussed on intra-cranial and carotid PC-MRA, with the goal of developing robust technology for real-world clinical imaging. The developed technology will also, in general, be valid for extra-neurological applications.
|Effective start/end date||07/01/2010 → 06/30/2012|