1CVM 6101Radiographic Anatomy of the AbdomenTravis C. Saveraid, DVM, DACVRMedical Imaging DepartmentCollege of Veterinary MedicineUniversity of MinnesotaVeterinary Medical CenterUNIVERSITY OF MINNESOTACVM 6101 [Imaging Anatomy]• Goals & Expectations:– Identify specific structures or parts thereof– Understand why the views (projections) look as they do– Keep in mind that the items listed in the “to know” lists are from the perspective of practicing radiologists– If asked, be able to describe what soft-tissue (muscle, tendon, ligament, vessel, or alimentary/parenchymal) structure(s) attach to, pass through, or lie in contact with a given anatomic landmark or regionVeterinary Medical CenterUNIVERSITY OF MINNESOTACVM 6101 [Imaging Anatomy]• Approach:– Introductory lectures defining the important structures and how they are viewed radiographically– Open session, instructor proctored group laboratory exercises wherein actual radiographs of the anatomic structures are viewed and understood– Web-based self-study sets both available on CD and from the web site http://www.academic-server.cvm.umn.edu/radiology//Veterinary Medical CenterUNIVERSITY OF MINNESOTA2CVM 6101 [Imaging Anatomy]• Sources of Information:– Anatomy Textbooks– Radiographic Anatomy Textbooks– General Veterinary Imaging Textbooks– U-MN Medical Imaging web site http://www.academic-server.cvm.umn.edu/radiology/Veterinary Medical CenterUNIVERSITY OF MINNESOTATo Know List1) liver•2)spleen• 3) left and right kidneys• 4) urinary bladder• 5) small intestine• 6) colon• 7) rectum• 8) prostate gland• 9) left and right diaphragmatic crura• 10) diaphragmatic cupola• 11) approximate area of the adrenal glands• 12) approximate area of the pancreas• 13) xiphoid of the sternum• 14) approximate area of the uterus• 15) approximate area of the left and right ovaries• 16) stomach: cardiofundic, body, and pylorus/pyloric antrum regions• 17) cecum18) approximate area of the caudal vena cava, aorta, and iliac (sublumbar) lymph nodes• 19) region of the falciform fatAbdominal CT images(single slice)DorsalSagittal3(*3 different dogs)• Left parasagittal• Midline sagittal• Right parasagittalNormal Lateral ViewsVeterinary Medical CenterUNIVERSITY OF MINNESOTANormal VD ViewsVeterinary Medical CenterUNIVERSITY OF MINNESOTA4Normal Canine AbdomenNormal (Fat) FelineNormal (Fat) Feline5Interpretive Background: Abdomen• Peritoneal organs (surrounded by peritoneum and obscured by peritoneal fluid) include liver, spleen, pancreas, alimentary organs, urinary bladder, uterus, ovary, prostate (depending on location) and mesenteric lymph nodes• Retroperitonealorgans (only partially surrounded by peritoneum and NOT obscured by peritoneal fluid) include great vessels, kidneys, adrenal glands, ureters (except very distal), urethra and retroperitoneal lymph nodesVeterinary Medical CenterUNIVERSITY OF MINNESOTACVM 6101 [Imaging Anatomy]• Diaphragm:–VÆD/DÆV and RÆL/LÆR views– Beware of superimposed structures including vertebrae, ribs, sternebrae, lungs, stomach, nipples, fascial planes, trachea, etc.– Remember, the diaphragm is a sling-like muscle that “actively” contracts (caudally) and “passively” relaxes (cranially) [numerous influences such as lungs, abdominal fat, etc.]Veterinary Medical CenterUNIVERSITY OF MINNESOTACVM 6101 [Imaging Anatomy]• Diaphragm: Specific Morphology– Hiatus for caudal vena cava– Hiatus for aorta– Hiatus for esophagus (esophagus, vagal n)• For more review, see normal thoracic lectureVeterinary Medical CenterUNIVERSITY OF MINNESOTA6CVM 6101 [Imaging Anatomy]Diaphragm– Aortic hiatusVeterinary Medical CenterUNIVERSITY OF MINNESOTACVM 6101 [Imaging Anatomy]Diaphragm– CVC hiatusVeterinary Medical CenterUNIVERSITY OF MINNESOTACVM 6101 [Imaging Anatomy]Diaphragm– Esophageal hiatusVeterinary Medical CenterUNIVERSITY OF MINNESOTA7CVM 6101 [Imaging Anatomy]• Stomach:–VÆD/DÆV and RÆL/LÆR as well as horizontal-beam views– Beware of superimposed structures including vertebrae, ribs, sternebrae, lungs, stomach, nipples, fascial planes, liver, etc.– Remember, the stomach is like a wine skin with an outlet on both ends (distension changes its shape)– The stomach responds to forces from regional organs and masses by changing shapeVeterinary Medical CenterUNIVERSITY OF MINNESOTACVM 6101 [Imaging Anatomy]• Stomach: Broad Anatomic Regions– Cardia– Fundus– Body– PylorusVeterinary Medical CenterUNIVERSITY OF MINNESOTAVeterinary Medical CenterUNIVERSITY OF MINNESOTANormal Abdominal Architecture8Interpretive Background: Abdomen• Useful interpretive criteria:– Liver size influences the “fundic-pyloric” axis• Normally parallel to last 2-3 ribs on lateral view• Normally perpendicular to spine on VD/DV views– Large liver or right-sided liver mass displaces pylorus caudally and to the left • remember F-P axis effect– Small liver allows pylorus to drift cranially• remember F-P axis effectVeterinary Medical CenterUNIVERSITY OF MINNESOTAFundic-pyloric axis• Normal axis between perpendicular to spine and parallel to caudal ribsCVM 6101 [Imaging Anatomy]• Stomach:– Appearance changes depending on DV (sternalrecumbency) vs. VD (spinal recumbency) views (with the X-ray beam is centered on the last rib): • On DV views, the gas is primarily in the cardiac region with less in the pyloric region; fluid is in the body region• On VD views, the fluid is primarily in the cardiac region with less in the pyloric region; air is in the body region• Appearance may vary depending on the relative amounts of fluid and gasVeterinary Medical CenterUNIVERSITY OF MINNESOTA9CVM 6101 [Imaging Anatomy]Stomach–DV– Gas in cardia and pyloric antrumVeterinary Medical CenterUNIVERSITY OF MINNESOTACVM 6101 [Imaging Anatomy]Stomach–VD– Gas in body/fundusVeterinary Medical CenterUNIVERSITY OF MINNESOTACVM 6101 [Imaging Anatomy]• Stomach:– Appearance changes depending on R vs. L recumbentlateral views (with the X-ray beam is centered on the last rib): • On R lateral views, the gas is primarily in the cardiac region with fluid in the pyloric region (may look like ball)• On L lateral views, the gas is primarily in the pyloric region with fluid in the cardiac region• Appearance may vary depending on the relative amounts of fluid and gasVeterinary Medical CenterUNIVERSITY OF MINNESOTA10CVM 6101 [Imaging Anatomy]Stomach– R