Short-Term Evaluation of Plaque Area Measurement Reproducibility from Computer-Assisted Sonography

Abstract

One reason why quantifying plaque regression is difficult is the poor spatial control of the shooting angle whether in angiography or ultrasonography techniques. A computer-assisted technique has been developed to assess absolute carotid plaque dimensions from B-mode ultrasonography, with enhanced capability of comparative examinations at large time intervals. Plaque area is measured from arterial lumen to adventitia with a real-time tissular detection program. Further measurements on the same patient are made using an echo-specific mask automatically generated by the computer from the original section. For an average sonographer, the manipulation takes no more than ten minutes for each view. In order to determine the reproducibility of this technique, a repeated measurement study (TO, T1, T2) was carried out on 8 patients with moderate to severe atherosclerotic lesions at carotid localizations. The plaque areas ranged from 52.7 to 202.3 mm2 (120.7 ±61). The coefficients of correlation between the measurements (T0-T1, T0-T2) were respectively 0.93 and 0.96 (P < 0.0001). The mean coefficient of variation (±SD) was 9.8% ±4.8. This study shows the feasibility of an accurate follow-up for atherosclerotic patients, with a two-dimensional plaque quantification, closer to the reality of the evolution of the pathology than the usual scoring system.