[Doppler sonography of the extracranial cerebral arteries: primarily a didactic problem].

Three graduate students were systematically trained to apply continuous wave Doppler sonography for non-invasive screening of the extracranial brain-supplying arteries. The method described by Büdingen et al. (1982) was used. Each student was trained on 100 patients by means of instruction and supervision. 50% of the patients had vascular lesions. In the course of the training period the students were individually tested on fourty-eight (4 x 12) selected patients having vascular lesions of varying site and degree. The students' diagnostic progress was compared with the author's own performance on initial self-training used cerebral angiography as a reference. All measurable parameters of the students' performance considerably improved during the training period. At the end of the course the trainees were accurate in the diagnosis of carotid lesions but still had considerable difficulties in assessing the degree of stenoses as well as in recognizing multiple lesions, and in particular lesions within the subclavian-vertebral circulation. It is concluded that training on only 100 patients is insufficient. Nevertheless the study clearly demonstrated the value of instruction through an experienced examiner, including immediate feed-back on the performance in any individual case examined. This kind of training has proved to be definitely superior to, and more efficient than self-training as exclusively based on checking the diagnosis by angiography.