Fig 1.

Flow diagram shows the enrollment and assessment of patients. * indicates the criteria for inclusion into the study, which were the availability of MR angiograms of good quality for diagnostic purposes, the acquisition of informed consent from the patients, and the absence of a history of brain surgery or risk factors such as heart failure. ** indicates cases in which one radiologist judged the quality of the CT angiograms and digital subtraction angiograms as excellent or good for diagnostic purposes. The results of the assessments of MR angiograms and CT angiograms were compared with those of DSA.