Postsurgical follow-up with MR imaging of aortic dissections

Fifteen patients with surgical repair for dissecting aneurysm were examined by MR imaging (0.5-T superconductive unit). Follow-up studies were obtained at 5-18 months after surgery. T1-weighted spin-echo sequences were acquired with electro cardiographic gating on axial, coronal, and sagittal oblique planes (20 degrees-30 degrees). Residual intimal tear in the native aorta was visualized, together with new or progressive extention of the dissection. No postoperative complications were present. MR imaging provided useful information regarding the evolution of the pathology and allowed noninvasive evaluation of the status of the native aorta. Differentiation between thrombotic material and slow-flowing blood in the false lumen was possible with use of gradient-echo sequences, which displayed the high signal intensity of flowing blood