Based on a systematic review, sensitivity is 87% and specificity is 92% for detecting intracranial aneurysms (IAs) (compared to catheter DSA) with significantly poorer sensitivity for aneurysms < 3mm diameter 1) 2) 3).
MRA’s ability to detect IAs depends on aneurysm size, rate, and direction of blood flow in the aneurysm relative to the magnetic field, and aneurysmal thrombosis and calcification. MRA may be most useful as a screening test in high-risk patients, including patients with two first degree relatives with IAs, especially those who are also smokers or hypertensive themselves 4).