Title: MR Angiography in the Preoperative Evaluation of Abdominal Aortic Aneurysms: A Preliminary Study
Abstract: PURPOSE:The ability of magnetic resonance (MR) angiography to depict visceral and renal vessels was evaluated in patients with abdominal aortic aneurysms (AAAs).PATIENTS AND METHODS: MR sequences (sagittal TI-weighted, two-dimensional coronal, and three-dimensional axial time-of-flight) were compared in a prospective blinded fashion with conventional angiograms obtained preoperatively in 23 patients with AAAs.Results were correlated with surgical findings when available.RESULTS: Operative aortic clamp site was correctly predicted with conventional angiography in 95% of patients and with MR angiography in 86% (P > .I).Aneurysm neck measurements obtained with the two modalities were within 1 cm in 91% of cases.With conventional angiography as the standard of reference, 96% of all renal arteries were identified on MR angiograms but 36% of accessory arteries were missed.MR angiography enabled identification of patients who had at least one renal artery stenosis greater than 50% with a sensitivity of 100% and specificity of 89%.For identifying individual renal artery, celiac artery, and superior mesenteric artery stenoses of similar severity, the sensitivity and specificity were 67% and in excess of 96%, respectively.The celiac artery could not be evaluated in one case.CONCLUSION: The results of this small study suggest that the role of MR angiography in the preoperative evaluation of AAA warrants further investigation.