3D Coronary Vessel Wall Imaging with a Local Inversion Technique and Spiral Image Acquisition

Introduction Coronary MRA has shown great potential for non-invasive assessment of the lumen of the coronary arteries (1), but it does not provide any information on the presence or magnitude of atherosclerotic plaque. It is also known that approximately 60-70% of acute coronary syndromes are caused by < 50% luminal diameter stenoses (2). Thus, a noninvasive approach for coronary plaque imaging would be desirable. Recently, MR coronary vessel wall and plaque imaging using dual inversion (Dual-IR) 2D fast spin echo techniques have been reported. It could be demonstrated that respiratory motion artifacts can be minimized by the use of breathholding or respiratory navigators and that both techniques allow for direct assessment of coronary wall thickness and the visualization of atherosclerotic plaque (3-6). However, for clinical use, 3D approaches would be more favorable as they allow for a more extensive coverage of the coronary artery tree and they offer the potential for higher spatial image resolution. The combination of a 3D-acquisition technique together with a Dual-IR pre-pulse can decrease the effectiveness of the Dual-IR preparation, thereby decreasing the black blood properties. We therefore implemented a 2D selective local inversion pre-pulse, which preserves the signal from the area of interest while minimizing unwanted signal from adjacent tissues and blood. We hypothesize that this approach allows for 3D black blood coronary vessel wall imaging.