Fig. 6

Example of cine FISS ASL for visualization and quantification of flow velocity in the left coronary arteries of a healthy subject. a 3-mm thick maximum intensity projection from oblique axial QISS MRA shows the left main and LAD coronary arteries (arrows). b Upper left frame shows graphical positioning of a 25-mm thick adiabatic inversion RF pulse through the aortic root which overlaps the sinuses of Valsalva and the ostium of the left main coronary artery. Remainder of frames (seven out of 32 acquired) acquired with cine FISS ASL (oblique axial orientation) show the progression of the labeled bolus (arrows) through the left main and LAD coronary arteries. The time between successive frames was 37.1 msec and the mean flow velocity between 444 msec and 615 msec after the R wave was 16.4 cm/s. c QISS MRA of the LAD (arrows) in an oblique coronal view. d MIP of three overlapping cine FISS ASL slices acquired in an oblique coronal plane through the LAD (eight frames displayed of 32 acquired). Blood in the aortic root was labeled in diastole, 580 msec after the R-wave (upper left frame). The labeled bolus (arrows) can be visualized as it progresses through nearly the entire length of the LAD. e The proximal LAD (inset, arrow) is seen in cross-section with 2D phase contrast using through-plane flow encoding (30 cm/s), permitting quantification of the diastolic flow velocity (which was similar to that measured by cine FISS ASL). f 2D phase contrast scan acquired with right-to-left flow encoding along the length of the LAD shows only faint, incomplete visualization of the vessel due to partial volume averaging and in-plane flow saturation