Abstract: Background- 2D shear wave elastography (2D-SWE) is a non-invasive method to measure liver fibrosis. Hypothesis/Objectives– The objectives of this study were trifold: 1) to assess the feasibility of performing 2D-SWE in awake cats, 2) to determine whether anesthesia altered shear wave velocity (SWV) measurements, and 3) to correlate hepatic stiffness with histologically quantified hepatic fibrosis. We hypothesize that cats with normal hepatic histology will have a mean shear wave speed 1.197 ± 0.25 m/s, similar to humans. Animals – Eleven healthy, research colony cats. Methods – The study followed a prospective, observational, crossover design. Feline health status was based on physical examination, CBC, serum biochemistry, and abdominal ultrasound. Cats underwent 2D-SWE in awake and anesthetized states. Ultrasound-guided needle biopsies of the liver were collected during the anesthetic period. Histology samples were deemed acceptable if > 15 portal tracts were present on H&E stained formalin fixed paraffin embedded (FFPE) histologic sections. Hepatic fibrosis was quantified using QuPath software on digitized Masson’s trichrome stained FFPE histology slides. Results – The mean velocities were not significantly different between awake (1.47 ± 0.18) and anesthetized cats (1.47 ± 0.24 m/s). There was a greater variability in the SWV values in the awake group. All cats had clinically insignificant fibrosis, and there was no correlation between the SWV measurements and the quantity of histological fibrosis. Conclusions and clinical importance – 2D-SWE is feasible in cats. Anesthesia did not impact mean SWV. 2D-SWE cannot detect minimal differences in hepatic fibrosis in healthy cats.
