Ultrasonographic characteristics of the portal venous system of 37 healthy,unsedated, student-owned cats: A prospective study

Objective The aim of this study was to determine portal vein and divisional branch diameters and portal vein velocities in healthy, unsedated cats, using B-mode and Doppler ultrasound.Animal Thirty-seven healthy, adult cats, all owned by students.Procedure Enrollment of cats in the study was done prospectively. Ultrasonographic imaging in both the longitudinal and transverse planes was assessed, with all examinations and measurements done by the same person. The assessment included the following 3 sites: extra-hepatic portion of the portal vein, intra-hepatic branches of the portal vein, and the aorta at the level of the porta hepatis. The Shapiro-Wilk test was used for normality and P < 0.05 was used to define statistical significance.Results Both the extra-hepatic portion of the portal vein and the porta hepatis were identified in all 37 cats (100%), whereas the aorta was recorded in 31 (84%), and the left and right intra-hepatic branches of the portal vein were seen in 29 (78%). Pulsed-wave Doppler ultrasound of the portal vein was obtained in 32 cats (86%). In longitudinal view, average maximal diameter of the extra-hepatic portal vein was 3.6 mm (± 0.7 mm), and the mean portal flow velocity was 14.6 cm/s (± 4.3 cm/s). In transverse view, average maximal diameter was 4.8 mm (± 0.8 mm) for the extra-hepatic portal vein, and 3.1 mm (± 0.8 mm) and 2.6 mm (± 0.7 mm) for the left and right intra-hepatic branches, respectively. The portal-vein-to-aorta ratio averaged 1.2 (± 0.2).Conclusion This study produced sonographic data of the portal venous system in healthy, conscious adult cats, which may be useful during investigation of liver diseases, including congenital and acquired liver diseases.