Liver Stiffness Measurements in Small Animals

Transient elastography (TE) to measure liver stiffness (LS) has been introduced more than 10 years ago and is now the most widely used commercially available method to screen for liver fibrosis worldwide. Although the human TE device has been successfully applied to measure LS in larger animals such as pigs or in other smaller organs such as spleen, there was a need to assess LS in smaller animals such as rodents. Recently transient micro-elastography (TME) or μFibroScan has been introduced by Echosens to measure LS in mice. TME has proven to be extremely useful to study LS in genetic mice models or LS and SS in rats in response to portal pressure modulating drugs in comparison to invasive pressure measurements. It also confirmed that LS is similar in small animal livers as compared to humans (~4 kPa). In comparison to TE, slightly adjusted parameter settings are used due to the smaller organ size and anatomy. TME has been also explored directly touching the surface of the liver without any pressure. Taken together, TME is a novel elastographic technique to measure LS and SS in rodents in order to better understand their molecular basis or pharmacodynamic responses in small animal models of cirrhosis.