High resolution, magnetization transfer saturation, variable flip angle, time-of-flight MRA in the detection of intracranial vascular stenoses

摘要: OBJECTIVE Factors that restrict 3D TOF MRA are limited resolution, saturation of flow, and degree background suppression. We evaluated for intracranial stenoses by using a technique minimizes these factors. MATERIALS AND METHODS Twenty-nine patients underwent intraarterial digital subtraction angiography (DSA). The studies were performed on 1.5 T Siemens SP 4000 system. Integrated techniques applied to the conventional acquisition included following: (a) 256 x matrix with 140 mm FOV 0.9 slice thickness, yielding 0.54 mm3 voxel; (b) tilted optimized nonsaturating excitation (TONE); (c) magnetization transfer (MTS). DSA was Angiostar system 1,024 noninterpolated matrix. MRAs reviewed two neuroradiologists. Two hundred seventy-seven vessels total 806 segments. Vessel segments 5 point scale. RESULTS estimated accuracy detecting stenosis over all vessel 0.88 +/- 0.03 0.89 0.02 readers, respectively. ranged from 0.94 0.93 internal carotid artery respectively, 0.65 0.17 0.71 0.15 distal vertebral stenosis. In determined catheter be stenosis-free, reader confidence at proximal versus similar carotid, basilar, posterior cerebral arteries. However, anterior middle arteries, one or both readers more confident in diagnosing segment. CONCLUSION High resolution MTS TONE is an accurate screening medium large stenoses.