Measurements and Visibility of the Pancreatic Ducts on Computed Tomography in 78 Cats Without Clinical Evidence of Pancreatitis

TL;DR

This study provides normal CT measurements for pancreatic ducts in healthy cats and shows that contrast imaging helps visualize these structures.

Contribution

The study establishes normal CT measurements for feline pancreatic ducts and highlights the importance of contrast imaging for visibility.

Findings

The average sizes of the left, right, and common pancreatic ducts in healthy cats are 1.4 mm, 1.1 mm, and 1.6 mm, respectively.

Post-contrast CT images significantly improve the visibility of the pancreatic ducts and duodenal papilla in cats.

The duodenal papilla was identified in 94% of post-contrast cases and had a mean diameter of 2.8 mm.

Abstract

Cats often suffer from diseases of their pancreas, which is an abdominal organ that produces enzymes that help digest food and also produces hormones, including those that regulate blood sugar. Vets use a type of imaging using X-rays called computed tomography (CT) to look at internal organs to help diagnose for pancreatic disease. It is important to know what internal organs normally look like so abnormalities can be recognised. This study looks at the CT appearance of the pancreas in a large group of 78 healthy cats and provides normal sizes for the internal ducts in the pancreas. The average size is 1.4 mm (left duct), 1.1 mm (right duct), and 1.6 mm where the two ducts join (common duct). Many CT studies of the abdomen in cats will include extra images acquired after a contrast agent which contains iodine is injected into the vein. This contrast agent highlights blood vessels and internal organs with a high blood supply, and this study shows that vets need the images after contrast to be able to reliably see certain small structures, including the duodenal papilla (a small round structure that marks where the pancreatic duct enters the bowel).

Imaging is commonly used to help diagnose pancreatic disease in cats. In order to establish normal computed tomography (CT) measurements for the pancreatic ducts in cats, images of 78 cats without clinical evidence of pancreatic disease, and with normal DGGR (1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6′-methylresorufin) ester lipase values, were evaluated retrospectively by two reviewers. The left pancreatic duct measured 1.4 ± 0.8 mm (mean ± standard deviation), the right pancreatic duct measured 1.1 ± 0.5 mm, and the common duct measured 1.6 ± 0.8 mm. All ducts were better visualised post-contrast, with the left pancreatic duct identified most frequently (not visualised on post-contrast images in only 3% of cases). There was visibility of the right and common hepatic ducts less frequently, not observed post-contrast in 22 and 20% of cases, respectively. The duodenal papilla measured 2.8 ± 0.7 mm in diameter. It had an HU of 43 ± 14 pre-contrast and 109 ± 32 post-contrast. It was identified in all but 6% of cases on post-contrast images. This study shows that the pancreatic ducts and duodenal papilla can be seen on post-contrast images and provides normal ranges of size for the pancreatic duct and duodenal papilla.

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