Abstract:

Objective: To explore the feasibility of quantitative evaluation of cirrhosis by geometrical characteristics of hepatic capsule based on high-frequency ultrasound imaging.

Methods: Rabbits with models of cirrhosis were established and then were divided into four groups: control, 6-week, 12-week and 18-week groups. Two-dimensional high-frequency ultrasound images of hepatic capsule of all rabbits were collected to obtain hepatic capsual contours and key points refltected shapes of these contours (shape control points) which were approximated by the principle of vertical gradient maximization under the manual supervision. Subsequently, the number of continuous segments of the contour line, the mean value and variance of angles between adjacent seed points were extracted to evaluate the continuity and smoothness of the contour line of the hepatic capsule.

Results: With aggravating cirrhosis, the number of segments required to make the sum of lengths of continuous segments reach up to 80% of the total width of the imaging section was gradually increased. The differences between the control group and 18-week group (P = 0.025) as well as between 6-week group and 18-week group (P = 0.004) were statistically significant. Similarly, the mean value and variance of the angles were also gradually increased, and the differences between the control group and the 6-week (P = 0.015, P = 0.036), 12-week (P < 0.001, P = 0.002) and 18-week groups (P = 0.023, P < 0.001) were statistically significant. In addition, the difference in variance of angles between the 6-week group and 18-week group (P = 0.030) was statistically significant.

Conclusion: Sonographic analysis of geometrical characteristics of the hepatic capsule could be used to partially indicate the presence of early-stage cirrhosis, which could provide a quantitative method for non-invasive assessment of cirrhosis.

Key words: Geometrical characteristics; Ultrasonography; Cirrhosis; Hepatic capsule; High frequency