Preoperative evaluation of abdominal aortic aneurysm by MR imaging with aortography correlation.

Sonography, computed tomography, and most recently, magnetic resonance imaging (MRI) have been advocated as noninvasive imaging methods for the preoperative evaluation of patients with abdominal aortic aneurysms (AAA). We prospectively assessed the value of MRI in this clinical setting. Twenty of 23 patients with AAA referred for evaluation with biplane aortography underwent MRI within 3 days of aortography. MR and angiographic studies were interpreted prospectively and independently and then the results were compared with each other and with the operative findings. All angiographically demonstrated infrarenal and suprarenal aneurysms except one were documented as such by MRI. The distal extent of the aneurysm on MRI agreed with that on angiography in all but 3 cases. MRI is an accurate method for assessing the size and extent of AAA and its relationship to the main renal artery origins. MRI is not accurate in detecting vascular obstructions or accessory renal arteries. Therefore, the usefulness of MRI and the need for aortography in preoperative assessment of AAA depends upon the specific information the surgeon requires prior to aneurysmectomy in a given patient.