Lemon MJ, Nelson NC.
Introduction/Purpose: Acute pancreatitis is the most common disease of the canine exocrine pancreas, and has a rapidly progressive course frequently associated with high morbidity and mortality rates . Diagnosis of canine pancreatitis is challenging , as no single test is definitive and results of biochemical tests may take several days to acquire. In humans , contrast-enhanced abdominal computed tomography is the test of choice for diagnosing pancreatitis, as it has good diagnostic accuracy and the severity of CT lesions is significantly associated with prognosis. Recent descriptions of the normal canine pancreas on CT have used a small number of dogs of similar breed and body size. The aim of this study was to further characterize the normal imaging characteristics of the canine pancreas on CT in a heterogeneous population of dogs.
Methods: Canine patients scheduled to undergo CT examination of body parts other than the abdomen with no previous history or clinical signs consistent with pancreatitis were enrolled. Non breath-he ld, sternal recumbent abdomi nal CT examinations consisted of pre-contrast and early and late post-contrast phases. Measurements performed included length of each lobe, and width and height of the body and lobes. Parenchymal attenuation values were measured within regions of interest placed in each lobe and in the body for all phases. Three dimensional volume rendering of the entire organ was also performed. Serum samples were submitted for pancreatic lipase immunoreactivity in order to rule out subclinical pancreatitis. Linear regression of multiple pancreatic dimensional values and body weight was performed.
Results: Position of the right and left lobes within the peritoneal space was variable between dogs, with the right lobe occasionally located very dorsal, adjacent to the spine. Attenuation values of the pancreatic parenchyma and pancreatic dimensions were similar to those reported in previous studies. However, the dimensional ranges varied widely between dogs. Average length of the right and left lobes was 8.4 cm and 7.4 em, respectively. The left lobe was consistently shorter than the right, and minimum left lobe length was 3.1 cm. Average height and width of the body was 1.8 cm and 4.3 cm. Average height and width of the right lobe was 17.6 cm and 15.8 em, while that of the left lobe was 15.8 cm and 21.2 cm. Average three-dimensional volume of the pancreas was 38 ern”. Pancreatic volume was highly correlated with body weight (R2=O.726; P<O.001). Significant relationships were also identified between body weight and left lobe length, right lobe width and left lobe width, though the strength of these correlations were less.
Discussion/Conclusion: The dimensional and x-ray attenuation characteristics of the pancreas included herein may be used as normal canine reference ranges, particularly for patients being evaluated for clinical signs consistent with pancreatitis. However, some pancreatic measurements are significantly associated with body weight. Therefore, pancreatic size should be evaluated in concert with patient body size.