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.

Cardiovascular magnetic resonance at 3.0T: Current state of the art

“…These studies have been conducted using a variety of different pulse sequences including segmented gradient echo (GRE) sequences [55,57,58,60,61], fast spin echo sequences [62], and recently, SSFP sequences [63,64]. There have been two studies directly comparing non-contrast coronary angiography images acquired at 1.5 and 3.0T.…”

“…To implement SSFP sequences at 3.0T, flip angles must be adjusted and/or repetition times increased. Obtaining consistent results when imaging the coronary arteries using SSFP sequences have proved difficult at 3.0T due to the high sensitivity of SSFP to off-resonance artifacts, and it has been suggested that better image quality may be obtained more consistently by using a spoiled GRE sequence instead of SSFP [60,61]. …”

Right coronary wall cmr in the older asymptomatic advance cohort: positive remodeling and associations with type 2 diabetes and coronary calcium

“…Several approaches are likely needed in combination to improve image quality and SNR in order to make this a more robust and reliable technique. These include optimized multi-element surface coils, 3 D acquisition[10,23], free-breathing methods to allow longer acquisitions[26], radial k -space sampling[27], and higher magnetic field strength, such as 3T[28-31]. …”

Clinical Applications for Cardiovascular Magnetic Resonance Imaging at 3 Tesla

“…In a study of patients with CAD, a free-breathing, navigator-gated technique for 3D coronary black blood imaging showed increased coronary vessel wall thickness in patients with mild CAD when compared to a healthy control population [53]. Preliminary studies of coronary vessel wall imaging at 3 T are promising and show the potential to detect preclinical disease and monitor treatment effects over time [52, 54]. …”