TRANSCRANIAL DOPPLER CORRELATION WITH ANGIOGRAPHY IN DETECTION OF INTRACRANIAL STENOSIS

Background and Purpose The purpose of this study was to evaluate the u se of velocity criteria applied to transcranial Doppler (TCD) signals in the detection of stenosis of the middle cerebral (MCA), distal vert ebral, and basilar arteries. Methods Sixty-five patients who underwent both cerebral angiography and transcranial Doppler examinations in th e workup of acute cerebral ischemia were reviewed. Angiography was per formed a mean of 7+/-5 days (range, 1 to 28 days) after TCD. Interpret ation of the angiogram was performed without input regarding the TCD f indings. TCD interpretation was performed according to standard criter ia. Results When we used a mean velocity (MV) cutoff of greater than o r equal to 80 cm/s in the MCA as the criterion for stenosis, 10 of 12 stenoses of any degree were detected by TCD, with 11 of 87 false-posit ives. Nine of 12 MCA stem (M1) stenoses were detected when a cutoff of greater than or equal to 90 cm/s was used, with 7 of 87 false-positiv es. When we used an MV cutoff of greater than or equal to 70 cm/s as t he criterion for greater than or equal to 50% stenosis of the vertebro basilar system, 5 of most important confounding factor was the presenc e of greater than or equal to 75% stenosis of the extracranial interna l carotid artery, resulting in both false-positive (from collateral fl ow) and false-negative (decreased volume flow from the proximal stenos is without adequate collateral flow) errors in TCD interpretation. Whe n patients with greater than or equal to 75% stenosis of the cervical internal carotid artery were excluded from analysis, a TCD MV cutoff o f greater than or equal to 80 cm/s identified 9 of 10 M1 lesions with 7 of 61 false-positives, and an MV of greater than or equal to 70 cm/s identified 3 of 4 vertebrobasilar lesions causing greater than or equ al to 50% stenosis with 7 of 56 false-positives. Conclusions TCD may b e an effective screening test for M1 stenosis when velocity criteria a lone are used. TCD may less reliably detect intracranial vertebral and basilar artery stenosis.