CEREBRAL radionuclide angiography with T cpertechnetate or DTPA (RNA) as part of cerebral serial scintigraphy has considerable sensitivity in detecting cerebrovascular disease. 1 We recently have published an algorithm which is useful in planning non-invasive diagnostic tests (RNA, Doppler sonography and transmission-computed tomography) for patients suspected of having cerebrovascular disease.2 Within this algorithm, the role of Doppler sonography (DS) was not well defined as there are no comparative data on sensitivity, specificity and diagnostic accuracy of this well established noninvasive method. 86Since DS is not expected to provide information on major intracranial cerebral artery lesions, and RNA can fail to detect extracranial lesions, the present study was designed to show whether the data obtained from DS would complement that of RNA and, thereby, increase the sensitivity of these non-invasive diagnostic methods. Efforts were made to compare the results of RNA and DS to findings obtained from radiographic angiography (RGA) by studying patients identified by RGA as having vascular alterations. Material and MethodsA total of 216 patients, all suspected clinically of having cerebrovascular disease, were studied by RNA and DS. Among these patients 86 had biplane RGA using the Seldinger technique. The results of this procedure were used to divide the patients into 3 groups: a) patients with normal angiogram, b) patients with arterial stenosis (more than 30% of the luminal