Objective: To determine the reproducibility of a simplified method of power Doppler 3-dimensional (3D) sonographic examination.
Methods: Twenty-nine patients with solid pelvic masses underwent transvaginal 3D power Doppler evaluation. The volume of interest was obtained by drawing the margins of the largest section of the mass in the 3 orthogonal planes. The 3D vascular parameters ("relative color," "average color," and "flow measure") obtained by our method were compared with those calculated by a manufacturer-suggested model based on several parallel section planes drawn on the longitudinal frames. The intraobserver variability was quantified on 5 different 3D images acquired by the same operator at 5-minute intervals for each patient. The intraobserver variability was also assayed in 10 patients at 24-hour intervals. Ten patients were scanned by a second sonographer for interobserver variability.
Results: There was high agreement between the 3D parameters obtained with the 2 methods. The 3D indices were similar in repeated observations at 5-minute intervals (median coefficients of variation for relative color, average color, and flow measure, 10.9, 4.5, and 13.0, respectively) and at 24-hour intervals (intraclass correlation coefficients for relative color, average color, and flow measure, 0.920, 0.978, and 0.978) and by the second sonographer (interclass correlation coefficients for relative color, average color, and flow measure, 0.978, 0.966, and 0.997).
Conclusions: The acceptable rates of intraobserver and interobserver variability make this approach potentially suitable for research protocols.