Non-contrast coronary magnetic resonance angiography: current frontiers and future horizons

Abstract

Coronary magnetic resonance angiography (coronary MRA) is advantageous in its ability to assess coronary artery morphology and function without ionizing radiation or contrast media. However, technical limitations including reduced spatial resolution, long acquisition times, and low signal-to-noise ratios prevent it from clinical routine utilization. Nonetheless, each of these limitations can be specifically addressed by a combination of novel technologies including super-resolution imaging, compressed sensing, and deep-learning reconstruction. In this paper, we first review the current clinical use and motivations for non-contrast coronary MRA, discuss currently available coronary MRA techniques, and highlight current technical developments that hold unique potential to optimize coronary MRA image acquisition and post-processing. In the final section, we examine the various research-based coronary MRA methods and metrics that can be leveraged to assess coronary stenosis severity, physiological function, and atherosclerotic plaque characterization. We specifically discuss how such technologies may contribute to the clinical translation of coronary MRA into a robust modality for routine clinical use.

Feasibility of 3.0 T balanced fast field echo non-contrast-enhanced whole-heart coronary magnetic resonance angiography

“…By applying the 3D free-breathing method to wholeheart coronary magnetic resonance angiography (CMRA), several studies have attempted to improve the assessment of coronary artery stenosis and provide an accurate diagnosis of clinically significant lesions (6). Previous studies had confirmed that both 1.5 T NCE-CMRA and 3.0 T contrast-enhanced coronary magnetic resonance (CE-CMRA) can detect coronary artery stenosis (7)(8)(9).…”

Radiation Dose Reduction Opportunities in Vascular Imaging

“…CMRA offers a radiation and contrast-free alternative for the evaluation of CAD, particularly for patients who can maintain a heart rate of less than 70 beats per minute. Additional benefits, including the simultaneous acquisition of anatomical and functional data combined with the lack of calcium blooming artifact, make CMRA a preferable choice in a variety of scenarios, including patients with chronic renal failure who are more prone to high coronary calcification burden [ 41 ].…”

“…In children, radiation reduction is of paramount importance due to the detrimental effects that cumulative radiation exposure may have on a child’s development and risk of cancer. Kawasaki disease, which requires monitoring for evaluation of coronary aneurysms, can result in high radiation exposure in children as coronary CTA has been the predominant surveillance method [ 41 ]. The Japanese Circulation Society guidelines support using coronary MRA over coronary CTA for monitoring Kawasaki patients to reduce radiation exposure, a recommendation initially made by the society in 2013.…”

Free-breathing high resolution modified Dixon steady-state angiography with compressed sensing for the assessment of the thoracic vasculature in pediatric patients with congenital heart disease

“…Furthermore, a sufficient fat suppression is important in order to differentiate small vessels from surrounding fatty tissue. The presented sequence also was combined with compressed sensing, which allows for an even shorter acquisition time without decreasing the spatial resolution [ 33 , 34 ].…”