title: Intracranial vascular stenosis and occlusion: comparison of 3D time-of-flight and 3D phase-contrast MR angiography.
abstract: We compared the value of 3D time-of-flight (TOF) and phase-contrast (PC) MR angiography (MRA) for detection and grading of intracranial vascular steno-occlusive disease. Unenhanced 3D-TOF MRA and 3D-PC MRA (30-60 cm/s velocity encoding) were performed at the level of the circle of Willis in 18 patients, mean age 56 +/- 10 years. Postprocessed images using a maximum-intensity projection reconstruction with multiple targetted projections were analysed. A total of 126 vessels was assessed by PC MRA and 143 by TOF MRA, with digital subtraction angiography (DSA) in 15 patients and/or transcranial Doppler sonography (TCD) in 18 as a standard. Two blinded readers reviewed the MRA, DSA and TCD examinations retrospectively. On DSA and/or TCD the two observers found 32 and 28 steno-occlusive lesions. 3D-TOF MRA was more sensitive than 3D-PC MRA (87% and 86% vs. 65% and 60%) and had a higher negative predictive value (96% vs. 89%). Correct grading of stenoses was achieved in 78 % by 3D-TOF and 65% by 3D-PC MRA.
authors.affiliation: Institute of Clinical Radiology, University of Münster, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Oelerich
authors.forename: M G
authors.initials: MG
authors.lastname: Lentschig
authors.forename: P
authors.initials: P
authors.lastname: Zunker
authors.forename: P
authors.initials: P
authors.lastname: Reimer
authors.forename: E J
authors.initials: EJ
authors.lastname: Rummeny
authors.forename: G
authors.initials: G
authors.lastname: Schuierer
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis*; D002941:Circle of Willis / Q000473:pathology; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D018810:Magnetic Resonance Angiography / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity; D017585:Ultrasonography, Doppler, Transcranial