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

Abstract

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.

Caval foramen hernia in a cat

“… 16 CT is commonly used to confirm caval foramen hernia. 1 , 5 In this case, it also enabled assessment of vasculature and identification of herniated structures, aiding anaesthetic and surgical planning. If there is no access to CT or if the client is financially constrained, the combined clinical, radiographic and ultrasonographic findings would provide indication for surgical intervention.…”

“… 1 However, another canine case reported lethargy since infancy and most cases were found incidentally in older patients. 1 – 5 These presentations are similar to another congenital diaphragmatic hernia, peritoneopericardial diaphragmatic hernia (PPDH). Cats with PPDH were a median of 1–2 years of age at diagnosis, with diagnosis occurring as late as 12.3 years.…”

“…In other cases of caval foramen hernia, only a small portion of omental fat or a single liver lobe were herniated. 1 – 5 In dogs, the right lateral liver lobe is most commonly affected, with ventral herniation with respect to the caudal vena cava. 1 In the present case, the diaphragmatic defect was relatively large, allowing herniation of multiple organs.…”

“…Radiographically, caval foramen hernias most often appear as a caudal dome-shaped soft tissue opacity broad-based to the diaphragm. 1 These can be confused for pulmonary masses. 1 , 5 In this case, the broad base helped prioritise diaphragmatic hernia over other origins.…”

“… 1 These can be confused for pulmonary masses. 1 , 5 In this case, the broad base helped prioritise diaphragmatic hernia over other origins. Caval foramen hernia was specifically considered because of the location of the soft tissue opacity and border effacement of the caudal vena cava.…”