Duplex scanning diagnosis of internal carotid artery dissections. A case control study

The reliability of duplex scanning (DS) for the diagnosis of internal carotid artery dissections (ICAD) is not clear.

Nine DS signs known to be suggestive for the diagnosis of ICAD were compared between 70 patients with ICAD and 70 matched patients without dissection.

Visible internal tapering occlusion, regular eccentric narrowing channel, ectasia beyond the carotid bulb, resistive index asymmetry, blood flow slowdown, ophthalmic artery blood flow inversion, and biphasic flow are more frequent in cases than in controls (p < 0.001). Atheroma plaques were absent in 80% of ICAD. When DS direct signs and hemodynamic signs were studied, sensitivity was 90% and specificity 60%.

Diagnosis of ICAD by DS could be improved if direct signs were combined with hemodynamic signs, giving a high sensitivity and a rather good specificity.