title: MR angiography of intracranial aneurysms: a comparison of 0.5 T and 1.5 T.
abstract: 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 intracranial aneurysms (n = 28), underwent MRA at 0.5 and 1.5 T. Images were interpreted by six trained observers who were blinded to diagnosis. Twelve projections of MRA of the circle of Willis, by maximum-intensity projection algorithm, were reviewed using continuous confidence-judgement 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 86% (mean 75%) at 1.5 T. In the smaller aneurysms less than 5 mm, the differences between the units became greater. The sensitivity for small aneurysms 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 confers higher accuracy in the detection of intracranial aneurysms with MRA with current-generation MR imagers.
authors.affiliation: Department of Radiology, Kumamoto University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Korogi
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: N
authors.initials: N
authors.lastname: Mabuchi
authors.forename: T
authors.initials: T
authors.lastname: Watabe
authors.forename: Y
authors.initials: Y
authors.lastname: Shiokawa
authors.forename: H
authors.initials: H
authors.lastname: Shiga
authors.forename: T
authors.initials: T
authors.lastname: O'Uchi
authors.forename: T
authors.initials: T
authors.lastname: Nakagawa
authors.forename: H
authors.initials: H
authors.lastname: Miki
authors.forename: Y
authors.initials: Y
authors.lastname: Horikawa
authors.forename: S
authors.initials: S
authors.lastname: Fujiwara
authors.forename: M
authors.initials: M
authors.lastname: Furuse
mesh_terms: D000465:Algorithms; D001158:Arteries; D001488:Basilar Artery / Q000473:pathology; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000473:pathology; D002831:Choroid Plexus / Q000098:blood supply; D002941:Circle of Willis / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D002532:Intracranial Aneurysm / Q000175:diagnosis*; D018810:Magnetic Resonance Angiography / Q000379:methods; D015588:Observer Variation; D009880:Ophthalmic Artery / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016037:Single-Blind Method