American Journal of Neuroradiology 2008;29:347.
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American Journal of Neuroradiology
DOI 10.3174/ajnr.A0789
BRAIN
Transcranial Color-Coded Duplex Sonography for Detection of Distal Internal Carotid Artery Stenosis
From the Department of Neurology (J.V.), Vilnius University Hospital, Santariskiu Klinikos, Vilnius, Lithuania; the Institute for Neuroradiology (G.S.), Bezirksklinikum Regensburg, Regensburg, Germany; the Department of Neurology (B.Z., U.B., F.S.), University of Regensburg, Bezirksklinikum Regensburg, Regensburg, Germany; and the Department of Neurology (J.D.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass.
Please address correspondence to F. Schlachetzki, MD, Department of Neurology, University of Regensburg, Bezirksklinikum Regensburg, Universitaetsstrasse 84, 93053 Regensburg, Germany; e-mail: felix.schlachetzki{at}klinik.uni-regensburg.de
BACKGROUND AND PURPOSE: Gradation of high-grade intracranial internal carotid artery (ICA) stenosis poses a challenge to noninvasive neurovascular imaging, which seems critical for angioplasty in the ICA segments C1 and C5. We investigated cutoff values of intracranial ICA stenosis for transcranial color-coded sonography (TCCS) and compared this method with the "gold standard," digital subtraction angiography (DSA).
Materials and METHODS: Forty patients (mean age, 58.9 ± 13.8 years) with intracranial ICA lesions were prospectively examined by using TCCS and DSA. Two standard TCCS coronal imaging planes were used to evaluate the intracranial ICA. In addition, a control group of 128 volunteers without cerebrovascular disease (mean age, 48.8 ± 15.9 years) was investigated to establish standard velocity values.
RESULTS: DSA confirmed 96 stenoses and 8 occlusions of the intracranial ICA in the study population. In 9% and 7% of cases, stenosis confined to the C1 or C5 segment was >50% and 70%, respectively. Receiver-operating curves demonstrated cutoff values for >70% stenosis in C1 when the peak systolic velocity (PSV) was >200 cm/s (specificity, 100%; sensitivity, 71%) or the C1/submandibular ICA index was >3 (specificity, 93%; sensitivity, 86%).
CONCLUSIONS: TCCS is a reliable adjunctive method to detect and quantify significant stenosis of the intracranial ICA. The assessment of the C1/ICA index and peak systolic velocities maximizes the diagnostic accuracy of C1 stenosis to >70% when extracranial ICA stenosis coexists. Further studies need to be performed to compare the diagnostic accuracies of MR angiography and TCCS with that of DSA.