Ultrasonography Grading of Internal Carotid Artery Disease: Multiparametric German Society of Ultrasound in Medicine (DEGUM) versus Society of Radiologists in Ultrasound (SRU) Consensus Criteria.

PURPOSE: We sought to determine the diagnostic agreement between the revised ultrasonography approach by the German Society of Ultrasound in Medicine (DEGUM) and the established Society of Radiologists in Ultrasound (SRU) consensus criteria for the grading of carotid artery disease. MATERIALS AND METHODS: Post-hoc analysis of a prospective multicenter study, in which patients underwent ultrasonography and digital subtraction angiography (DSA) of carotid arteries for validation of the DEGUM approach. According to DEGUM and SRU ultrasonography criteria, carotid arteries were independently categorized into clinically relevant NASCET strata (normal, mild [1-49 %], moderate [50-69 %], severe [70-99 %], occlusion). On DSA, carotid artery findings according to NASCET were considered the reference standard. RESULTS: We analyzed 158 ultrasonography and DSA carotid artery pairs. There was substantial agreement between both ultrasonography approaches for severe (κw 0.76, CI95 %: 0.66-0.86), but only fair agreement for moderate (κw 0.38, CI95 %: 0.19-0.58) disease categories. Compared with DSA, both ultrasonography approaches were of equal sensitivity (79.7 % versus 79.7 %; p = 1.0) regarding the identification of severe stenosis, yet the DEGUM approach was more specific than the SRU approach (70.2 % versus 56.4 %, p = 0.0002). There was equality of accuracy parameters (p > 0.05) among both ultrasonography approaches for the other ranges of carotid artery disease. CONCLUSION: While the sensitivity was equivalent, false-positive identification of severe carotid artery stenosis appears to be more frequent when using the SRU ultrasonography approach than the revised multiparametric DEGUM approach.

Validation of Multiparametric Ultrasonography Criteria with Digital Subtraction Angiography in Carotid Artery Disease: A Prospective Multicenter Study.

PURPOSE: The German Society of Ultrasound in Medicine (DEGUM) recently revised its multiparametric criteria for duplex ultrasonography (DUS) grading of internal carotid artery (ICA) disease. We determined the diagnostic accuracy of the revised DEGUM criteria for ultrasonography grading of ICA disease in a prospective multicenter study. MATERIALS AND METHODS: We evaluated consecutive patients who underwent digital subtraction angiography of the extracranial carotid arteries at four tertiary care hospitals. Blinded investigators graded ICA disease according to DEGUM-recommended ultrasonography criteria and calculated NASCET-type percent stenosis from angiography images. Endpoints included overall classification accuracy, prediction of clinically relevant disease categories and between-test agreement in the continuous range of percent stenosis. RESULTS: A total of 121 patients (median age: 69 [IQR, 16] years; 74 % men; median time between DUS and angiography: 1 day [IQR, 2]) provided 163 DUS-angiography carotid artery pairs. The classification accuracy of the DEGUM criteria to predict stenosis within 10 % increments as compared to angiography was 34.9 % (95 % CI, 28.0 - 42.6). The sensitivity of DUS for the detection of moderate (50 - 69 %) and severe (70 - 99 %) stenosis was 35 % and 81 %, with an overall accuracy of 73 % and 74 %, respectively. The specificity was 89 % and 69 %, respectively. Considering the continuous spectrum of the disease (0 - 100 %), the Bland-Altman interval limit of agreement was 51 %. CONCLUSION: At laboratories experienced with ultrasound grading of the extracranial ICA, the revised DEGUM multiparametric ultrasonography criteria do not eliminate the need for a confirmatory test for the identification of clinically relevant grades of the disease.