Magnetic resonance imaging of the thoracic aorta.

Magnetic resonance imaging (MRI) is steadily becoming recognized as a premier imaging modality for evaluating the thoracic aorta. Its noninvasive, nonimaging approach and refined resolution capabilities effectively combine the advantages of echocardiography, angiography, and computed tomography (CT) under the auspices of a single imaging device. On static spin-echo MRI, blood flow appears dark, allowing superb depiction of both intra- and extra vascular anatomy. With dynamic MR studies, gradient echo (cine) and phase velocity mapping techniques have proven effective in assessing the physiological consequences of anatomic vascular abnormalities in a qualitative and quantitative manner, respectively. Magnetic resonance angiography (MRA) is fast becoming a prominent vascular imaging method. Although still evolving, MRA bolsters the vascular imaging capabilities of MRI by enhancing the imaging resolution of the major branch vessels and collateral vessels. With continued advances in this area, MRI may adopt the role as the primary imaging method for assessing the thoracic aorta.