Comparison of 3D-ultrasound of the carotid vessels with contrast enhanced magnetic resonance angiography

Purpose: Duplexsonography of internal and common carotid artery (ICA and CCA) is routinely performed in diagnosis of stroke, as about 20% of ischaemic strokes are caused by large-artery atherosclerosis. Here, we introduce a new method of sonographic 3D-visualization of the carotid vessels and compare it with contrast enhanced magnetic resonance angiography (CE-MRA). Method: Curefab CS (Curefab GmbH, München, Germany) is a mobile computer hard- and software attachment to conventional ultrasoundsystems allowing 3D-reconstruction of vessels. Fifty carotid vessels of 25 patients were examined by 3D-ultrasound (2 investigators) and CE-MRA. Besides total length of sonographically detectable ICA distal to the bifurcation also cross section area of CCA and ICA were measured. Inter-rater reliability between the two investigators and between each investigator and MRA was calculated by using intraclass correlation coefficient (ICC). Results: Mean length of reconstructed ICA distal to the bifurcation was 31 mm for both investigators. Mean ICC (absolute agreement) between investigator 1 and investigator 2 for CCA & ICA was 0,90 (standard deviation [sd] 0,08) respectively 0,73 (sd 0,22) for ICA only. Mean ICC (consistency) between investigator 1 respectively investigator 2 and CE-MRA for CCA & ICA was 0,67 (sd 0,20) respectively 0,65 (sd 0,21) and 0,79 (sd 0,17) respectively 0,75 (sd 0,19) for ICA only. Conclusion: Native 3D-ultrasound visualization of carotid vessels is feasible and shows a good agreement in comparison with CE-MRA. These results warrant application of 3D-ultrasound for grading carotid artery stenosis based on the local morphology as complementary method to the well-established flow-based classification.