Cornputerised analysis of liver texture with correlation to needle biopsy

Aim: To assist in tissue characterisation for the non-invasive diagnosis of diffuse fatty liver infiltration by providing quantitative indices of ultrasonic (US) backscatter with correlation to histology. Methods and Materials: US images from patients referred to US-guided liver needle biopsy (LNB) for persistently elevated liver enzymes or serologically positive markers for viral hepatitis were recorded. The histopathological reports were reviewed. Steatosis, inflammation and degree of fibrosis were scored from 0 (normal) to 3 (severe). Patients with level 3 steatosis without inflammation or fibrosis were selected. US images from twenty-four healthy subjects served as control. Four textural indices were calculated for a selected ROI corresponding to the biopsy site. Sensitivity and specificity of discrimination between the two groups were evaluated. Results: Fatty and healthy livers formed two distinct clusters. However, in all parametric sub-spaces there was a slight overlap between the groups with a few numbers of cases located across the dichotomy line. The sensitivity for all the indices was high (90-100%). The specificity for each of the indices was moderate. The co-occurrence local homogeneity index yielded the highest specificity (88.5%), with a sensitivity equivalent to two of the other indices (90%). Conclusions: Highly accurate "ultrasonic biopsy" may be obtained for severe fatty liver. The described indices can serve as a tool in US computer-aided diagnosis (CAD) of diffuse parenchymal liver disease, in particular for severe steatosis of the liver.