[Magnetic resonance imaging in dissection of the aorta]. / Imagerie par résonance magnétique au cours des dissections de l'aorte.

ABSTRACT

In order to evaluate the usefulness of this new exploratory method in dissection of the aorta, 13 patients (10 men and 3 women, mean age 58 +/- 14 years) were examined by means of an 0.5 Tesla Magniscan 5000 nuclear magnetic resonance machine. Fifteen examinations were performed 5 in patients with actual aortic dissection (type A 4 including one acute, type B1), 5 in patients previously operated upon for type A dissection and 5 for suspected acute aortic dissection unconfirmed by other examinations. Magnetic resonance imaging (MRI), synchronized with electrocardiography, was carried out using spin-echo techniques with 1 to 3 echoes and multiple contiguous sections along several planes. In the 5 patients with actual dissection the 2 channels separating the membrane could be demonstrated, thus providing a firm diagnosis (MRI proved superior to angiography in 2/5 patients). All 5 patients could be classified as either type A or type B. Extension to the cervical vessels was observed in 3 cases and the portal of entry was seen in one case, but the origin of the coronary arteries was never visualized. In the 5 patients previously operated upon MRI provided detailed analysis of the prosthesis of the supra-coronary ascending aorta implanted in all cases, of the aorta proximal and distal to that segment and of the periaortic mediastinum. By studying the signal from the false channel distal to the prosthesis information was obtained as to the presence in it (2 patients) or absence of circulating blood.(ABSTRACT TRUNCATED AT 250 WORDS)