Evaluation of cerebral aneurysms with helical CT: correlation with conventional angiography and MR angiography.

Abstract

To evaluate detection of intracranial aneurysms with helical computed tomography (CT) and compare the results with those of conventional angiography and magnetic resonance (MR) angiography. Twenty-one patients with 30 intracranial aneurysms were studied with helical CT and conventional angiography; 17 of the patients (24 aneurysms) also underwent MR angiography. All aneurysms 3 mm or larger in greatest dimension were seen with helical CT and MR angiography; no aneurysms smaller than 3 mm were apparent with either modality. Of the 21 aneurysms demonstrated with both helical CT and MR angiography, 11 were seen equally well with both techniques; six were seen better with helical CT owing to flow-related or motion artifact at MR angiography, and four were seen better with MR angiography because calcium partially obscured them at helical CT. Helical CT is a promising noninvasive method of imaging the intracranial vasculature and is comparable with standard MR angiographic techniques in demonstrating aneurysms.