Fast MRI flow imaging by sparse sampling and segmentation

Abstract

Clinical use of cardiac synchronized Magnetic Resonance Imaging has been limited because of long unacceptable acquisition times. BRISK (Block Regional Interpolation Scheme for k-space) is a rapid MRI technique, which employs temporal sparse sampling scheme that varies the sampling rate as a function of distance from the k-space center. Using combination of conventional segmentation and BRISK approach, a new rapid phase contrast cine approach named FAST was investigated. FAST technique samples contiguous regions of k-space using a segmentation factor, just as in conventional segmentation, with the difference that the segmentation factor (SF) is varied as a function of distance from the k-space center. FAST and BRISK can be performed in nearly equally scan times. Both retained excellent axial-velocity accuracy. However secondary velocities, which were two orders of magnitude lower than the primary, suffered from comparable inaccuracies and distortion in conventional segmentation, BRISK and FAST.