Quantitative evaluation of fibrosis by geometrical characteristics of hepatic capsule based on ultrasonic images:an experimental study / 中华超声影像学杂志

ABSTRACT

Objective To explore the feasibility of quantitative evaluation in fibrosis by geometrical characteristics of hepatic capsule based on computer technology . Methods Fifty-nine rabbits models of fibrosis were established and then were divided into four groups according to the results of pathologic examinationS0-S1 ,S2 ,S3 and S4 groups . Two-dimensional high-frequency ultrasound images of hepatic capsule of the rabbits were collected at 6th week ,12th week and 18th week . All the images were collected to obtain the contour line of the capsule and its shape control points by combining manual monitoring and gradient optimization methods . Subsequently ,the mean value and variance of angles between adjacent seed points and the number of continuous segments of the contour line ,were extracted to evaluate the smoothness and continuity of the contour line of the hepatic capsule . Results With aggravating fibrosis ,the mean value and variance of the angles were gradually increased ,and the differences between S0-S1 and other 3 groups were all statistically significant( P <0 .05) . Similarly ,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 S0-S1 and S4 group( P =0 .025) ,S2 and S4 group( P =0 .004) were also statistically significant . Conclusions Analysis of geometrical characteristics of the hepatic capsule partially indicates the presence of early-stage fibrosis ,and is expected to provide a quantitative method for non-invasive assessment of fibrosis .