MR-ANGIOGRAPHY OF INTRACRANIAL ANEURYSMS - A COMPARISON OF 0.5 T AND 1.5 T

The objective of this paper is to compare the diagnostic efficacy of 3 DFT time-of-flight MR angiography (MRA) at middle-field-strength and high-field-strength in diagnosis of intracranial aneurysms. Thirty-one patients, including 26 patients with angiographically confirmed intra cranial aneurysms (n=28), underwent MRA at 0.5 and 1.5 T, Images were interpreted by six trained observers who were blinded to diagnosis, Tw elve projections of MRA of the circle of Willis, by maximum-intensity projection algorithm, were reviewed using continuous confidence-judgme nt scales. It was found that MRA at 1.5 T was more sensitive than that at 0.5 T in detection of aneurysms, The sensitivity of six observers ranged between 50 and 64% (mean 56%) at 0.5 T, and between 61 and 86% (mean 75%) at 1.5 T, In the smaller aneurysms less than 5 mm, the diff erences between the units became greater, The sensitivity for small an eurysms ranged from 23 to 54% (mean 32%) at 0.5 T, and from 31 to 69% (mean 58%) at 1.5 T. Our conclusion was that high field strength confe rs higher accuracy in the detection of intracranial aneurysms with MRA with current-generation MR imagers. (C) 1997 Elsevier Science Ltd.