Radiographic anatomy of the canine liver: simple measurements determined from the lateral radiograph

Abstract

The literature on plain film evaluation of the canine liver is reviewed and the problems associated with radiographic hepatometry in this species and in man are outlined. Methods used to determine liver size in man are briefly described. Liver measurements obtained from lateral recumbent radiographs of 20 German Shepherd Dogs were examined statistically. The ratio of a measurement of liver length to second lumbar vertebra body length was found to be of statistical value, as was the relative position of the junction separating left medial, right medial and quadrate lobes from a further part of the right medial and left lateral lobes. The extrapolation of these results to other breeds is discussed.

Evaluation of the radiographic liver length/11th thoracic vertebral length ratio as a method for quantifying liver size in cats

“…One previous study reported evidence that excessive fat deposition in the falciform ligaments may result in dorsal deviation of the liver parenchyma in cats . Elongation of the triangular ligament in older cats may result in caudal and dorsal extension of the liver, which can also be misdiagnosed as hepatomegaly . In our clinical experience, dorsal deviation of the liver in obese cats without liver disease has often been misdiagnosed as microhepatia.…”

“…Changes in hepatic size are frequently used as indicators of liver disease . Hepatic vascular stasis, steroid hepatopathy, hepatic lipidosis, inflammatory, and infiltrative disease, and neoplasia are differential diagnoses of hepatomegaly, and hepatic lipidosis is one of the most common liver diseases in cats .…”

“…Hepatic vascular stasis, steroid hepatopathy, hepatic lipidosis, inflammatory, and infiltrative disease, and neoplasia are differential diagnoses of hepatomegaly, and hepatic lipidosis is one of the most common liver diseases in cats . Congenital vascular anomalies of the portal vein, chronic hepatic inflammation, and liver cirrhosis may lead to a reduction in liver size . However, in cats, it can be difficult to determine whether change in radiographic liver size is caused by liver disease, in contrast to the relationship between liver size and liver disease observed in dogs …”

“…We have also observed that the liver of healthy young and neonatal cats can be misinterpreted as hepatomegaly. In dogs, it is generally known that the size of the liver varies greatly depending on the breed and body conformation . However, cats do not exhibit as much variation in body conformation according to breed.…”

“…In dogs, the liver length is also known to be affected by respiratory phase . A radiographic ratio of liver length to the 11th thoracic vertebral length (LL/T11 ratio) has been previously described as a method for objective assessment of liver size in dogs . Additionally, in human medicine, liver volume measured by CT has been found to correlate with actual liver weight, regardless of the underlying liver disease …”