Grading of Hepatic Steatosis by Ultrasound Quantification

Fatty liver is the most common chronic liver disease, and finding the appropriate method for detecting the problem is necessary. The current study aimed to quantity liver steatosis using Computed Tomography (CT), ultrasound images, and Alanine Aminotransferase (ALT) blood test.

In this work, 163 Non-Alcoholic Fatty Liver Disease (NAFLD) patients implemented CT and ultrasound images on their abdomen regions. The liver and spleen density were calculated using CT images (as the standard method), and then the patients were divided into mild, and moderate to severe groups. During the sonography, an M-value histogram of the liver and the right kidney was drawn and their ratio (liver/kidney) was considered as a Hepatorenal Index (HRI). Mann-Whitney test was used to evaluate the relationships between HRI and ALT values.

The mean and standard deviation of the liver density in CT scans were obtained as 51 ± 4 HU. The HRI had better performance (Area Under the Curve, AUC: 0.94) than the ALT (AUC: 0.88) in determining liver steatosis. In addition, there was a significant difference between the mild, and moderate to severe groups (P < 0.001) in HRI and ALT values.

Based on the results, HRI is an excellent factor to distinguish between mild, and moderate to severe fatty liver. Notably, HRI is reproducible and operator-independent.