Signalment: 8 year old MN Miniature Schnauzer

Radiologist's Description: A large aberrant vessel (wide arrow) connecting the portal vein with the azygos (long arrow) is noted. The aberrant vessel is similar in diameter to the caudal segment of the portal vein. Color flow Doppler (blue) demonstrates blood flow away from the portal vein towards the azygos, which runs paralell to and between the aorta and vena cava. This is consistent with portosystemic shunting. Moderate to marked reduction in portal vein diameter cranial to the shunt (small arrrow) consistent with hypoperfusion is noted. Conclusions: Extrahepatic macroscopic portoazygos shunt.

Definitive Diagnosis: US and Sx Dx: Portoazygos (Splenoazygos) shunt.