Coronary vessel-wall and lumen imaging using radial k-space acquisition with MRI at 3 Tesla

Abstract

This study investigates the feasibility of imaging the coronary lumen and vessel-wall, using MRI with a radial k-space trajectory at 3 T. Such radial trajectories offer the advantage of greater vessel sharpness than traditional Cartesian trajectories. This field strength offers an increased signal-to-noise ratio (SNR) compared with 1.5 T, which compensates for the slight SNR reduction due to the radial sequence. Images of the coronary lumen were acquired for seven healthy volunteers. In ten volunteers the vessel wall was scanned, with blood suppression using oblique-slab adiabatic re-inversion. Scans were performed during free breathing, using prospective respiratory navigator-gating. Coronary lumen scans had SNR of 16.0+/-1.9 and contrast-to-noise ratio (CNR) of 10.3+/-2.1, showing acceptable image quality. Vessel wall images showed good image quality, with mean SNR of 16.6+/-2.0/5.8+/-2.8/10.1+/-2.2 for vessel wall/lumen/epicardial fat. The wall-blood CNR was 10.7+/-2.7, and wall-fat CNR was 6.5+/-2.5. It is concluded that radial gradient-echo imaging at 3 T is a promising method for coronary vessel-wall imaging, and is also feasible for imaging the coronary lumen.