Coronary MR angiography (coronary MRA) is a developing approach to imaging the coronary arteries.
Advantages of coronary MRA include avoidance of the intravenous iodinated contrast and ionizing radiation used in coronary CT angiography and conventional angiography.
A disadvantage of coronary MRA has been a problem with low signal-to-noise ratio when trying to image a small vessel with free breathing sequences. Current techniques also typically involve long scan times since ECG-gated and respiratory-gated acquisition is necessary to avoid motion blurring.
- 1.5 T: coronary MRA typically relies on SSFP sequences (gadolinium contrast not necessary for this sequence).
- 3 T: coronary MRA typically relies on gradient echo (GRE) sequences with a double dose of IV contrast agent.
- fat-saturation techniques (such as STIR or SPIR) are necessary to suppress epicardial fat surrounding the coronary arteries
- a T2W magnetization preparation pulse suppresses myocardial signal and venous blood signal in the epicardial veins
3 T GRE contrast-enhanced whole heart coronary MRA sensitivity (94%) and specificity (82%) approaches that of 64-slice coronary CTA, but data about its prognostic ability has not yet been developed.
- 1. Ishida M, Sakuma H. Magnetic resonance of coronary arteries: assessment of luminal narrowing and blood flow in the coronary arteries. J Thorac Imaging. 2014;29 (3): 155-62. doi:10.1097/RTI.0000000000000081 - Pubmed citation
- 2. Nagata M, Kato S, Kitagawa K et-al. Diagnostic accuracy of 1.5-T unenhanced whole-heart coronary MR angiography performed with 32-channel cardiac coils: initial single-center experience. Radiology. 2011;259 (2): 384-92. doi:10.1148/radiol.11101323 - Pubmed citation