Aortic Arch Aneurysm: CT and MR Features

Kim, Dong Hun; Kim, Hyae Young; Kim, Sung Moon; Lee, Jin Seung; Song, Koun Sik; Song, Meong Gun; Lim, Tae Hwan

Abstract

PURPOSE: The purpose of this study was to evaluate the CT and MR features of aortic arch aneurysms and todetermine the differences between involved segments and morphologic types according to their causes.
MATERIALS AND METHODS
Twenty-nine patients with aortic arch aneurysms who underwent CT scanning(n=24) and/or MR imaging(n=16)were retrospectively evaluated. The aneurysms were analyzed with respect to location of involved segment,morphology, direction and size, and morphologic differences between aneurysms were compared according to causes.
RESULTS
The causes of arch aneurysms were atherosclerosis in 25 patients(86%), trauma in three (10%) and infection in one (4%). Arch aneurysms were frequently located at the arch only(n=17,59%), ascending aorta toarch(n=6,21%), arch to descending aorta(n=4,14%), or ascending aorta to descending aorta(n=2,7%). The shape of theaneurysm was fusiform in 15 patients and saccular in 14. Atherosclerotic aneurysms(n=25) were fusiform in 15patients and saccular in ten. Arch aneurysms due to trauma and infection(n=4) were saccular. MRI was more helpfulthan CT scanning involved site, direction, and morphology of the aneurysm.
CONCLUSION
Bothe CT scanning and MRIeasily diagnose arch aneurysms, though MRI is a very useful imaging modality for evaluating involved aorticsegments and morphologic types. Aortic arch aneurysms are either fusiform or saccular. Most saccular aneurysmsinvolve the aortic arch, whereas the involvement of fusiform aneurysms is more varied. Atherosclerosis is the mostcommon cause of both fusiform and saccular arch aneurysms.