Postsurgical follow-up of aortic dissections by MRI.

Fifteen patients with surgical repair for dissecting aneurysm were examined by Magnetic Resonance Imaging (MRI), using a 0.5 T super-conductive unit. Follow-up studies were obtained at 1 to 18 months (mean 7.2) post-surgery. T1-weighted spin-echo sequences were acquired with ECG gating on axial, coronal and oblique sagittal planes. In 6 patients gated gradient rephased sequences were also employed. Residual intimal tear in the native aorta was visualized in 11 patients, together with new or progressive extention of the dissection and aneurysmatic development. Gradient rephasing sequences were useful in detecting slow flow and thrombotic deposits and in evaluating relations to aortic vessels and intimal flap. MR images provided useful information on pathology allowing a non invasive evaluation of the status of the aorta.