Adrian A, Twedt D, Kraft SL.
Introduction/Purpose: Computed tomography (CT) is considered the gold strandard for diagnosing pancreatitis in humans. The most common canine exocrine pancreatic disease is pancreatitis. A combination of clinical signs, hematology and chemistry results, various serum/blood assays, and B-mode ultrasound (US) are commonly used in an attempt to diagnose pancreatitis in dogs. Although advanced disease can be detected with US, there are inherent limitations. Dogs with suspected pancreatitis were enrolled in a prospective study to describe the CT appearance of canine pancreatitis.
Methods: After clinical and US diagnosis of pancreatitis, a sedated 3-phase angiographic CT was performed. After completion of the CT, each dog had US guided aspirates of the pancreas and blood drawn for a cPLi assay. Images were evaluated for portion of visible pancreas, pancreatic size, evaluation of the pancreatic parenchyma (attenuation), presence of peri-pancreatic changes and contrast enhancement pattern. The CT attenuation and enhancement were compared to the liver.
Results: Seven dogs have been enrolled in the study. One of those dogs had a previous body and left limb pancreatectomy. 4/7 dogs had a positive cPLi test, 1/7 was questionable and 2/7 were negative. On CT all pancreata were visualized in their entirety. In 7/7 dogs the right limb and body of the pancreas were affected. Additionally in 2 dogs the left limb was also affected. The affected pancreata were enlarged (right limb mean 2.61 cm, body mean 2.25cm and left limb mean 2.45cm). The parenchyma was homogenous in all left limbs, 5/6 bodies and 6/7 right limbs. 5/6 left limbs and bodies and 6/7 right had ill-defined borders. None of the dogs had evidence of pancreatic mineralization or adjacent gas. The mesentery was hyperattenuating surrounding 2/6 left limbs and bodies and 3/7 right limbs. Surrounding free fluid was seen in 4/7 cases. The contrast enhancement pattern in all 3 phases was homogenous in 5/6 left limbs and bodies and in 6/7 right limbs. In patients with heterogenous contrast enhancement the delayed phase was best to identify ring-like and patchy enhancement. Fine needle aspirates showed no cytologic abnormalities in 3/7 cases, inflammation in 2/7 cases and 2/7 were non- diagnostic. 6/7 dogs had a fluid filled stomach. The common bile duct was visualized in 4/7 dogs, and 2 ducts were dilated. CT identified thrombi in the portal vein in 2/7 dogs and a cholelith in 1 dog. The pancreatic duct was visualized in 2 patients, both of which were considered normal.
Discussion/Conclusion: An enlarged, homogenously to heterogenously attenuating and contrast enhancing pancreas, with ill-defined borders is consistent with pancreatitis. Inflammatory changes of the pancreas can lead to visible attenuation differences and altered contrast enhancement. The apperance of the surrounding mesentery can vary. A fluid-filled stomach is often present. Careful evaluation of the portal vein is recommended to evaluate the presence of a thrombus.