Transient elastography: a novel, non-invasive method for the evaluation of liver stiffness and controlled attenuation parameter in cows

This study investigated the use of transient elastography (TE) as a tool for the non-invasive evaluation of liver stiffness and controlled attenuation parameter (CAP) in cows. A total of 85 cows were used for this study. After the liver was located and subcutaneous tissue thickness was checked by means of ultrasonography, liver stiffness and CAP were measured using TE. At least 10 measurements were taken per individual cow. In addition, intraclass correlation coefficients were calculated for intra-rater and two-rater inter-rater reliability of liver stiffness and CAP measurement, and were evaluated. Of the 85 cows, 61 (71.8%) were measurable owing to their significantly less body weight and subcutaneous tissue thickness compared with those of unmeasurable cows. Liver stiffness showed no significant differences among sexes, ages, or breeds. CAP showed no significant differences among sexes and breeds. Intra- and inter-rater reliabilities for liver stiffness and CAP were almost perfect. Both liver stiffness and CAP could be quantitatively evaluated with good reproducibility in cows using TE, and CAP increased with the growth of the cows. However, evaluation was not possible in obese cows or cows with high values for subcutaneous tissue thickness or body weight.