PREOPERATIVE ASSESSMENT OF ABDOMINAL AORTIC-ANEURYSM - THE VALUE OF HELICAL AND 3-DIMENSIONAL COMPUTED-TOMOGRAPHY

Purpose: The purpose of this study was to evaluate the utility of heli cal computed tomography (CT) in the preoperative assessment of abdomin al aortic aneurysms (AAA) and to compare its accuracy with aortography and operative findings.Methods: Thirty-two patients with suspected AA A were evaluated by helical CT with either 5 mm collimation (slice thi ckness) or a combination of 3 mm collimation through the renal and mes enteric arteries and 7 mm collimation through the remainder of the AAA . Three-dimensional reconstructions were performed with use of three d ifferent techniques, and results were compared with aortography and su rgery. Results: Twenty-five patients were found to have an aneurysm, a nd 19 subsequently underwent surgery. Standard angiography was also pe rformed in 13. The location, size, and extent of the aneurysm, as well as the wall calcification and intraaneurysmal thrombus, were well dep icted with helical CT. The visceral aortic branches, including the det ection of renal artery stenosis and accessory renal arteries, were con sistently seen with the 3 mm/7 mm collimation protocol and three-dimen sional reconstruction. Conclusion: Helical CT with three-dimensional d isplay of the aorta and its branches combines the advantages of conven tional CT imaging and aortography. This technique appears to provide c omprehensive preoperative evaluation of AAA.