[Evaluation of blood flow in aortic aneurysm and dissection by cine magnetic resonance imaging]

The blood flow in aortic aneurysms and dissections was evaluated using cine MR imaging which depicts turbulent blood flow as a signal loss within a high-intensity blood pool or flowing blood. Six patients with 8 aortic aneurysms ranging 38 to 70 mm in diameter, and 16 patients with aortic dissections were imaged with a 0.5 or 1.5 T superconducting magnet using an ECG-gated fast field echo technique. Circulating flows were observed in 3 of 8 aortic aneurysms. This suggests that turbulent blood flow did not occur prominently in the relatively small aortic aneurysms imaged in this study. The false lumens were thrombosed in 2 of 16 aortic dissections. In 13 of the remaining 14 dissections jet flows were observed through the entry into the false lumen. In 2 of these cases the jet flows moved to and fro through the entry. The entry was not detected in a small abdominal aortic dissection. Re-entry was seen in one case. Using a spin-echo imaging technique, the entry can be diagnosed by detecting the interruption of the intimal flap and the flow void within the false lumen. However, the entry was more clearly depicted and the direction of blood flow better determined by cine MR imaging compared with the conventional spin-echo imaging technique. Cine MR imaging provides useful information about the blood flow in aortic aneurysms and dissections noninvasively.