A New 2D-Based Method for Carotid Intima-Media Thickness Quantification From Ultrasound Sequences

BACKGROUND: Ultrasound measurement of carotid Intima-Media Thickness (IMT) is a suitable method to evaluate subclinical arteriosclerosis. OBJECTIVES: The current study aimed to present a new computerized algorithm to detect instantaneous changes of the IMT to Common Carotid Artery (CCA) of IMT in sequential ultrasound images by applying the maximum gradient and the dynamic programming. PATIENTS AND METHODS: In a cross-sectional design, an examination was performed on thirty healthy human subjects with the mean age of 44 ± 6 years from April 2013 to June 2013 in Beheshti Hospital, Kashan, Iran. In all individuals, the instantaneous changes of the far wall IMT on the CCA were extracted. Local measurements of vessel intensity, intensity gradient, and boundary continuity were extracted for all of the sequential ultrasonic 2D-frames throughout three cardiac cycles. The Pearson correlation coefficients and Bland-Altman analysis were performed to assess the relationship and agreement between IMT measured by the proposed and conventional manual methods. RESULTS: There was no significant difference between the proposed and manual methods with paired t-test analysis (in systole: 0.57 ± 0.10 vs. 0.56 ± 0.10 mm; P = 0.188 and in diastole: 0.63 ± 0.16 vs. 0.62 ± 0.10 mm; P = 0.122 for the manual and proposed methods, respectively). The Pearson correlation coefficients were r = 0.94 and r = 0.93 for IMT(s) and IMT(d), respectively (both P < 0.001). Limit of agreements were narrow and considerable agreement was found between the two methods. CONCLUSIONS: The present study demonstrated that the proposed computerized analyzing method can provide accurate measurements of the IMT of the CCA in sequential 2D ultrasonic images.