Detection frequency, sonoanatomy and reference values of the duodenal papillae and connected anatomical structures in cats

To describe the detection frequency, sonoanatomy and reference values of the duodenal papillae and connected anatomical structures in cats, with reference to gross anatomical and histopathological nomenclature. A prospective, case-controlled study of sonographic examinations of the duodenal papillae in 50 client-owned cats using an ultrasound device (Logiq E9, GE Healthcare) with a 15 MHz linear transducer. The major duodenal papilla was found in 100% of cases, the minor duodenal papilla in 10%. The common bile duct and the main pancreatic duct could be traced to the duodenum in all of the cats. After an extramural part, in which the two ducts extend in a parallel fashion, they entered the duodenal wall. The subsequent intramural part was divided into three sections: the portio infundibularis, the portio submucosa and the major duodenal papilla. The 27 clinically healthy cats had a mean portio infundibularis length, width, and height in mm of 3.7, 2.5 and 2.2, respectively. These dimensions were 3.5, 2.1, 2.9 for the portio submucosa and 0.5, 2.1, 2.9 for the major duodenal papilla. Calculi in the major duodenal papilla were found in 12% of the cats. The course of the accessory pancreatic duct from the pancreas through the MIDP into the duodenum was documented. The ultrasonographic examination of the duodenal papillae is easy to perform and it can be considered part of the routine examination for feline patients presenting with relevant clinical signs, in some cases to help establish a diagnosis and plan treatment.