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 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.
- 1.5T: coronary MRA typically relies on SSFP sequences (gadolinium contrast not necessary for this sequence).
- 3T: 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
3T 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.
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