Reliability of cerebral radioisotopic angiography and of directional Doppler C.W. in the diagnosis of cerebrovascular insufficiency.

The diagnostic value of radioisotopic cerebral angioscintigraphy (R.A.) and of Doppler CW (D.C.W.) techniques to identify stenosis of the internal carotid artery in its extracranial course was studied in 97 patients with ischaemic lesions (50 T.I.A. and 47 Complete Stroke). The results of R.A. and D.C.W. were compared with those of contrast carotid-angiography (C.A.). C.A. revealed stenosis above 50% or complete occlusion in 22% of cases, whereas D.C.W. and R.A. showed flow reduction in 27% and 48% of the cases respectively. In T.I.A., C.A. positivity went down to 8%; D.C.W. to 16%; and R.A. to 34%. In "Complete Stroke" positivity was 36% for C.A.; 41% for D.C.W.; and 62% for R.A. There was a high number of false positive findings with D.C.W. (8) but even more with R.A. (27). False negative findings occurred only in two cases with R.A. These data confirm the diagnostic value of these two noninvasive techniques to identify haemodynamically carotid stenosis. The use of both methods can reduce error due to false negativity. The rather marked frequency of false positivity, particularly with reference to R.A. doesn't affect the diagnostic value of the two methods.