Today's Veterinary Practice

MAY-JUN 2018

Today's Veterinary Practice provides comprehensive information to keep every small animal practitioner up to date on companion animal medicine and surgery as well as practice building and management.

Issue link: https://todaysveterinarypractice.epubxp.com/i/969768

Contents of this Issue

Navigation

Page 61 of 87

PEER REVIEWED 60 IMAGING ESSENTIALS In the cat, the left lobe of the pancreas is larger than the right lobe and extends to the left close to the splenic hilum ( FIGURE 5 ). Body The body is located where the right and left lobes come together, immediately ventral to the portal vein and common bile duct. Occasionally, the pancreatic duct is seen as two thin hyperechoic lines that are 1 mm apart in the center of the pancreas. 1,2 In the cat, the body of the pancreas and the pyloroduodenal junction are in a more midline position ( FIGURE 6 ). NORMAL ULTRASONOGRAPHIC FEATURES Adequate ultrasound imaging of the pancreas is highly dependent upon the ultrasonographer's skills and knowledge of the regional anatomy. The pancreas is an elongated organ that is localized by using various anatomic structures: the body is located at the pyloroduodenal junction, immediately ventral to the portal vein; the left lobe is caudal to the greater curvature of the stomach; and the right lobe is located in the mesoduodenum in the dog ( FIGURE 7 ). 1-5 Patient factors also play a role in ultrasound imaging. Excessive aerophagia and inadequate fasting often result in significant shadowing and reverberation artifacts from the gastric contents. These artifacts will likely obscure the region of the left lobe and body of the pancreas, making assessment of these structures challenging or impossible, particularly in dogs. The normal pancreas, if visualized, is isoechoic to slightly hypoechoic to the surrounding mesentery. The boundaries of the pancreas are delineated by thin hyperechoic lines. The normal canine pancreas is 6 to 8 mm thick with a pancreatic ductal diameter of 0.6 mm. The normal feline pancreas is 4 to 6 mm thick with a pancreatic ductal diameter of 1 mm. FIGURE 4. Sagittal reformatted CT image of the abdomen from a dog (the cranial aspect of the patient is on the left side of the image, and the dorsal aspect of the patient is at the bottom of the image) ( A ). Long axis ultrasound image from a cat ( B ). In both images, the portal vein ( PV ) is dorsal to the pancreas ( white arrow ). ST , stomach; GB , gallbladder; CVC , caudal vena cava; LI , liver. A B FIGURE 5. Transverse ultrasound image of a cat's left cranial abdomen caudal to the stomach ( ST ), showing the left pancreatic lobe ( LP ) in long axis extending across the screen. The left lobe of the pancreas is normal, measuring 4 mm thick ( white arrows ), and is hypoechoic relative to the surrounding mesentery without any mesenteric reaction. The spleen is located just out of plane to the right of the image.

Articles in this issue

Archives of this issue

view archives of Today's Veterinary Practice - MAY-JUN 2018