Introduction:
Novel multi-parametric criteria for duplex ultrasonography (DUS) grading of extracranial internal carotid artery (ICA) steno-occlusive disease have been recently introduced by the German ultrasound expert panel (DEGUM). We sought to determine diagnostic accuracy of the DEGUM criteria against the gold standard catheter angiography.
Methods:
We prospectively enrolled consecutive patients who routinely underwent diagnostic or therapeutic catheter angiography of the extracranial carotid arteries in four German study sites. Internal carotid artery disease was graded according to the DEGUM multi-parametric criteria for DUS. On angiography, extracranial ICA disease was graded using the NASCET approach. Ultrasonography and endovascular raters were blinded to clinical data and any other imaging modalities. To correspond to clinically relevant NASCET groups, all stenosis measurements were stratified into ranges: normal, mild (1-49%), moderate (50-69%), severe (70-99%) and occlusion.
Results:
We studied 130 patients who underwent both DUS and catheter angiography for assessment of carotid arteries (mean age, 64±11 years; 67% men; median time between DUS and angiography, 1 day [interquartile range, 2.5]). To date, fifty-two carotid artery pairs were independently rated and available for comparative analysis. Compared with catheter angiography, DUS had the following positive (PPV) and negative predictive values (NPV): PPV 50% and NPV 72% (3 true positive, 3 false positive, 33 true negative, 13 false negative) for detection of moderate, and PPV 57% and NPV 77% (20 true positive, 15 false positive, 13 true negative, 4 false negative) for detection of severe stenosis.
Conclusions:
Our preliminary data indicate that the novel DEGUM multi-parametric ultrasonography criteria do not eliminate the need for a confirmatory test for identification of clinically relevant grades of extracranial ICA disease.
Noninvasive techniques for diagnosis of carotid artery disease.
