title: Comparison of accuracy of magnetic resonance angiography with conventional angiography: a report of 45 cases.
abstract: To investigate the accuracy of magnetic resonance angiography (MRA), compared to conventional cerebral and carotid angiography (CA), 45 patients underwent MRA within one week after CA. The MRA involves a FISP (fast imaging steady precession) pulse sequence base on three-dimensional time-of-flight phenomena at 1.0 Tesla. Repetition time of 35-40 msec, echo time of 7-11 msec and a flip angle of 15-25 degrees were used to optimise the depiction of blood flow as high intensity. Volume data were then submitted to a maximum intensity projection programme and viewed at multiple arbitrary projection angles rotating through the three orthogonal planes. Venous structures were suppressed with a presaturation slab superior to the area of interest. All significant stenoses and occlusions at the carotid bifurcation and circle of Willis were detected. Other than the carotid siphon (61.4%), the rest of the arteries have above 70% complete agreement between MRA and CA. The carotid bifurcation and basilar artery show complete agreement of 75.4% and 76.2% respectively, making MRA a simple sensitive screening procedure. This report shows that MR angiography has an important role in the evaluation of blood flow in the head and neck regions.
authors.affiliation: Department of Diagnostic Radiology, Singapore General Hospital.
authors.forename: K H
authors.initials: KH
authors.lastname: Toh
authors.forename: K P
authors.initials: KP
authors.lastname: Tan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D001488:Basilar Artery; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D002533:Cerebral Angiography; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000175:diagnosis / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity