Validation of an automated computerized analyzing system for measuring common carotid artery intima-media thickness by brightness mode ultrasound

Background and Purpose.-Evaluation of subclinical atherosclerosis by B-mode carotid ultrasound intima-media thickness (IMT) is an endorsed technique whose ease and precision is improved by use of automated IMT measurement algorithms. We report results of a validation study of SonoCalc, an automated IMT software program. Methods.-Three vascular sonographers measured the mean common carotid artery IMT twice of 120 near and far wall CCA segments from 30 subjects by manual electronic instrument calipers and with SonoCalc. Results.-Accuracy analysis indicated the equivalence of SonoCalc IMT measurements to those with manual electronic instrument calipers (p < 0.0001). The coefficient of variation (CV) was calculated for each set of duplicate SonoCalc and manual electronic instrument calipers measurements. The average SonoCalc-manual electronic instrument calipers CV differences significantly favored SonoCalc (p < 0.0001). Conclusion.-This study demonstrated that the use of the SonoCalc and the manual electronic instrument calipers produced measurements whose differences were statistically insignificant. Furthermore, the analysis to assess reproducibility of the two methods showed that the SonoCalc method was significantly more reproducible than the manual electronic instrument calipers methods.