IS TRANSCRANIAL DOPPLER A WORTHWHILE ADDITION TO SCREENING-TESTS FOR CEREBROVASCULAR-DISEASE

Purpose: Carotid duplex imaging has become the standard diagnostic eva luation for patients with suspected cerebrovascular disease. Transcran ial Doppler ultrasonography expands the noninvasive diagnostic capabil ities to the intracranial circulation. The purpose of this study was t o evaluate the results of routine transcranial Doppler studies on pati ents referred for noninvasive cerebrovascular evaluation. Methods: A t otal of 670 patients had routine transcranial Doppler examinations as part of their noninvasive cerebrovascular evaluation. Patients were ca tegorized clinically and according to their severity of extracranial i nternal carotid artery stenosis (<50%, 50% to 79%, 80% to 99%, occlusi on). Transcranial Doppler examinations were classified as normal or ab normal (intracranial stenosis, collateral pathway, >30% velocity diffe rence between sides, how reversal, and velocities +/-2 SD from normal) . Results: Forty-eight percent of the patients were women, and 52% wer e men. The average age was 65.5 years. Fifty-four percent of the patie nts were white, 42% were black, 3% were Hispanic, and 1% were other. F orty-eight percent presented with hemispheric symptoms, 34% had no sym ptoms, and 18% had nonhemispheric symptoms. Forty-five percent (304 of 670) had an interpretable transcranial Doppler examination. The abili ty to insonate the basal cerebral arteries through the temporal bone w as significantly reduced in women (p < 0.0001), black patients (p < 0. 0001), and older patients (p < 0.0001). The results of forty-four perc ent of interpretable examinations were normal, 19% demonstrated side-t o-side velocity differences, 13% showed collateral pathways, 11% showe d velocities +/-2 SD, 10% showed an intracranial stenosis, and 4% show ed reversed flow pattern. Although 56% of the patients had notable fin dings, no patient had their diagnostic or therapeutic plan altered by the transcranial Doppler results. Conclusion: Less than 50% of the pat ients referred for first-time cerebrovascular examination had access f or an interpretable transcranial Doppler examination. Though the numbe r of positive findings is reasonably high, no material impact on diagn ostic or treatment plans was seen in the patients in this series. Thes e results indicate that selection criteria for examination of the intr acranial arteries should be refined and that transcranial Doppler scan ning should not be incorporated as part of the ''routine'' noninvasive cerebrovascular examination.