[Area reduction in carotid stenosis of the internal carotid artery]

In patients with atherosclerotic extracranial internal carotid artery (ICA-) stenosis the diagnostic value of colour Doppler energy (CDE)-coded duplexsonography was compared to three other methods: continuous wave (cw) Doppler peak systolic frequency (pF), pulsed wave (pw) Doppler peak systolic velocity (pV), and intraarterial digital subtraction angiography.

In 58 patients who suffered from 60 moderate to severe ICA stenoses, B-mode sonography combined with CDE-coded duplex sonography was applied to measure the extent of the stenosis by determining the residual lumen width. Results were correlated to pF and pV and with various angiographic indices.

The determined values of the degree of stenosis were correlated to the measurement of pV (r = 0.441, p < 0.01), but not to pF (r = 0.122, n.s.). The best correlation to angiography was obtained when the linear ICA diameter was compared to the distal common carotid artery (common carotid artery index) (r = 0.214, n.s.). Sensitivity, specificity and diagnostic accuracy were comparable to the different frequency-based measurements, but the positive predictive value was lower.

Determination of the degree of stenosis based on CDE alone is not reliable enough to allow correct diagnosis of severe carotid artery stenosis. In combination with the peak frequency method is's diagnostic value could be improved. This requires verification in a separate study.