Radiographic and computed tomographic features of caval foramen hernias of the liver in 7 dogs: mimicking lung nodules.

This study describes the imaging features and characteristics of caval foramen hernias in 7 dogs diagnosed by computed tomography (CT). On lateral radiographs, 6 of 7 dogs showed dome-shaped, broad-based, caudal mediastinal lesions. CT findings included caudal vena cava (CVC) compression (n=7), right lateral (n=6) or medial (n=1) liver lobe involvement, hepatic vein dilation (n=5) and biliary tract involvement (n=1) with partial (n=6) or entire (n=1) liver lobe hernias. A caval foramen hernia should be part of the differential diagnosis when the aforementioned imaging features are detected. CT is considered as a useful tool for diagnosis and evaluation in dogs with a caval foramen hernia.