TRANSCRANIAL DOPPLER ULTRASOUND BATTERY RELIABLY IDENTIFIES SEVERE INTERNAL CAROTID-ARTERY STENOSIS

Background and Purpose There is a clinical imperative for noninvasive tests for carotid disease that have high sensitivity. Previous studies have shown that transcranial Doppler ultrasound (TCD) can identify in tracranial collateral flow patterns and other hemodynamic consequences of carotid occlusion. We hypothesized that a battery of such TCD find ings would have a greater sensitivity than any one TCD finding alone a nd would have clinical utility in identifying carotid disease. Methods We determined the prevalence of seven TCD findings in patients with v arious degrees of carotid stenosis as measured by a blinded observer o n 138 cerebral angiograms. We further determined the sensitivity and s pecificity of any one finding or any single abnormality in the TCD bat tery (the combination of all seven findings) for identifying severe (g reater than or equal to 70%) carotid stenosis by angiography. Results The following four individual TCD findings were associated (P<.001) wi th greater than or equal to 70% carotid stenosis on cerebral angiograp hy: ophthalmic and anterior cerebral artery flow reversal and low midd le cerebral artery flow acceleration and pulsatility. The presence of any single abnormality in the TCD battery had a similar association (P <.001) with greater than or equal to 70% carotid stenosis. The individ ual TCD findings had sensitivities of 3% to 83% and specificities of 6 0% to 100% for identifying greater than or equal to 70% carotid stenos is. The TCD battery had a sensitivity of 95% and specificity of 42% fo r identifying greater than or equal to 70% carotid stenosis. Conclusio ns A battery of TCD findings that can be routinely measured reliably i dentified patients with greater than or equal to 70% angiographic inte rnal carotid artery stenosis with high sensitivity.