[Magnetic resonance: the usefulness of gradient-echo refocusing sequences in the diagnosis of aneurysms of the abdominal aorta]. / Risonanza magnetica: utilità delle sequenze gradient echo refocusing nella diagnostica degli aneurismi dell'aorta addominale.

Sixteen patients bearing aneurysms of the abdominal aorta were studied by means of a 0.5 T MR unit. Spin-echo T1-weighted sequences and gradient-echo refocusing sequences were performed. All patients were previously submitted to US; in 8 cases angio CT was performed, and in 6 patients angiography of the abdominal aorta. A comparative analysis with the US findings showed a high correlation coefficient for the maximum diameters (R = 0.93) while site and size evaluations were not accurate. A very high correlation coefficient for the maximum diameters (0.97) was found at the comparative analysis with CT findings, while in two cases an erroneous suprarenal location was described. Angiographic examination provided valuable information about renal and iliac involvement, but the maximum diameters could not be accurately assessed. Spin-echo MRI allowed good evaluation of the maximum size, of location and extent of the aneurysm, as well as of iliac involvement; this technique, however, was useless in the characterization of the thrombus. Gradient-echo refocusing sequences have proven very useful for the identification of endoluminal contours and for the correct evaluation of the thrombus. Spin-echo sequences, on the contrary, accurately assessed only 7 cases, whereas the diagnosis was uncertain in the remaining 4 patients.