Ultrasound imaging in an experimental model of fatty liver disease and cirrhosis in rats

Forty Wistar rats (30 treated, 10 controls) were included. Liver injury was induced by dual exposure to CCl4 and ethanol for 4, 8 and 15 weeks. Liver echogenicity, its correlation to the right renal cortex echogenicity, measurement of portal vein diameter (PVD) and the presence of ascites were evaluated and compared to histological findings of hepatic steatosis and cirrhosis. Liver echogenicity correlated to hepatic steatosis when it was greater or equal to the right renal cortex echogenicity, with a sensitivity of 90%, specificity of 100%, positive and negative predictive values of 100% and 76.9% respectively, and accuracy of 92.5%. Findings of heterogeneous liver echogenicity and irregular surface correlated to liver cirrhosis with a sensitivity of 70.6%, specificity of 100%, positive and negative predictive values of 100% and 82.1% respectively, and accuracy of 87.5%. PVD was significantly increased in both steatotic and cirrhotic rats; however, the later had greater diameters. PVD cut-off point separating steatosis from cirrhosis was 2.1 mm (sensitivity of 100% and specificity of 90.5%). One third of cirrhotic rats presented with ascites.The use of ultrasound imaging in the follow-up of murine diffuse liver disease models is feasible and efficient, especially when the studied parameters are used in combination. The potential implication of this study is to provide a non-invasive method that allows follow-up studies of fatty liver disease and cirrhosis of individual rats for pre-clinical drug or cell based therapies.Domestic dogs and cats are very well known to develop chronic hepatic diseases. Hepatic lipidosis (HL) or fatty liver is an important liver disease in cats. It is characterized by excess fat accumulation in the liver and seems to have no age, breed, or gender predilection [1,2]. HL is more common in obese or previously obese cats which have undergone brief periods of anorexia or food deprivation [3]. Obesity in cats has been described as the most prev