Three-dimensional color-coded duplex sonography for assessment of the vertebral artery origin and vertebral artery stenoses

Objective. The aim of the study was to assess the potential of 3-dimensional (3D) color-coded duplex sonography (CDS) for evaluation of the vertebral artery origin and stenoses in this location. Methods. To compare 2-dimensional (2D) and 3D CDS, both techniques were performed in 25 healthy volunteers and in 18 patients with 21 stenoses of the vertebral artery origin. Stenoses were graded in line with hemodynamic criteria on 2D CDS and according to North American Symptomatic Carotid Endarterectomy Trial criteria on 3D CDS. In 6 patients, digital subtraction angiography (DSA) Was performed additionally. Stenoses were graded according to North American Symptomatic Carotid Endarterectomy Trial criteria and compared with 2D and 3D sonographic data. Results. Overall correlation of both sonographic techniques concerning the grading of the stenoses was good (r = 0.69; P < .01). The interobserver correlation for assessment of stenoses by means of 3D CDS was high (r = 0.94; P < .01). Three-dimensional CDS correlated excellently with DSA in 3 of 6 patients but showed only intermediate or no correlation in the remaining 3 patients. In contrast, spatial information on the stenotic morphologic characteristics was always very comparable with the results obtained by DSA. Conclusions. Three-dimensional CDS represents a valuable tool for assessment of the origin of the vertebral artery, allowing important morphologic information on stenoses in this location. For grading of stenoses of the vertebral artery origin, 3D information should be combined with hemodynamic criteria obtained by spectral Doppler imaging in 2D CDS. Three-dimensional CDS could be a valuable tool before interventional procedures of the proximal vertebral artery, saving time and avoiding iodinated contrast agents.