Introduction to Abdominal Radiology

1. Introduction to Abdominal Radiology Dr. LeeAnn Pack Dipl. ACVR

2. Abdominal Radiography • Abdominal Preparation • Withhold food for 12-24 hours as needed • Give enema 2-3 hours before study • Exceptions • Critically ill • Suspect obstruction (acute abdomen)

3. Indications • Vomiting • Abdominal pain • Hematuria • Pain on defecation • Abdominal mass • Pendulous fluid filled abdomen • Many many more

4. Abdominal Imaging Technique • VD and lateral views • Positioning • Include from the diaphragm to the pelvic inlet • Femurs are placed perpendicular to the spine • Hind legs pulled forward for “butt shot” • Exposure is made on expiration • Collimate to decrease scatter!

5. Normal Abdomen

6. Technical Factors - Abdomen • The image should be made dark enough to penetrate the liver • The abdomen has a low inherent contrast • Use lower kVp technique and higher mAs • A grid should be used to decrease scatter

7. Liver Spleen Kidneys Stomach Duodenum Small Intestine Cecum Colon Bladder Prostate Retroperitoneal fat Structures Normally Seen

8. Gall bladder Pancreas Adrenals Ovaries Uterus Ureters Lymph nodes Mesentery Vasculature Structures Not Normally Seen

9. Radiography of the Liver • Liver size • Normal • Increased • Decreased • Liver opacity • Increased • decreased

10. Normal Liver Lateral View • Caudoventral margin extends to or slightly caudal to the costal arch • Long axis of the stomach should be parallel to the ribs or perpendicular to the spine

11. Normal Liver VD View • Long axis of the stomach is perpendicular to the spine • Caudal margins of the liver are difficult to visualize on this view

12. Hepatomegaly • Caudoventral margin projects caudal to costal arch • Liver margins may be rounded • Pylorus is displaced caudodorsally and to the left • Change in long axis of stomach

13. Hepatomegaly • Generalized with smooth margins • Cushing’s • Fatty infiltration • Diabetes Mellitus • Hepatic lipidosis • Passive congestion • RHF • Neoplasia • LSA • Inflammation, cholestasis

14. Hepatomegaly • General enlargement lumpy margins • Malignant neoplasia • Nodular hyperplasia • Focal enlargement • Neoplasia • Nodular hyperplasia • Cysts, abscesses

15. Microhepatia • Stomach shifted cranially – especially pylorus • May be functionally normal • Portosystemic shunt • Hepatic fibrosis

16. Changes in Liver Opacity • Increased • Mineralization • Biliary – choleliths • Parenchymal • Parasitic cysts • Granulomatous ds • neoplasia • Decreased • Gas

17. Spleen • On the VD view the head of the spleen is seen • caudolateral to the stomach fundus • craniolateral to the left kidney • The position of the tail varies • More often seen on right lateral • In cats • seen “laying along left side” sometimes on VD • Not seen routinely on lateral

18. Normal Spleen

19. Splenomegaly • Normal shape, smooth margins • Drug induced • Sedatives, anx • Diffuse infiltrative process • LSA, HSA • Vascular stasis • Splenic torsion

20. Drug Induced Splenomegaly

21. Splenomegaly • Focal enlargement • Hematoma • Nodular hyperplasia • Neoplasia • Hemangiosarcoma • Hemangioma

22. Splenic Masses • May occur in the head, body or tail • Located mid abdomen, left or right • May be very large • Can cause abdominal organ displacement • Can displace stomach cranially and small intestines in various direction depending on location

23. Kidneys • Right located more cranial than left • Dogs = 2½-3½ * L2 on VD • Cats = 2.4-3 * L2 on VD • Size should only be evaluated on the VD view due to magnification on the lateral • IV contrast can be used if necessary

24. Kidneys • Increase in size • Acute inflammation • Infiltrative process • LSA • Decrease in size • Hypoplasia • Fibrosis • Renal failure • Mineralization – look a kids on both views • Focal change in shape • ACA

25. Check Out the Ureters

26. Stomach • Caudal to liver • Axis parallel to ribs • Change in size, shape, mineralized, rugal fold abnormal • Right vs. Left lateral (air/fluid) • Foreign bodies, outflow obstruction

27. Stomach • Dog – crosses from left to right • Cat – from left to midline

28. Which one is Left? Right?

29. Gastric FB - Bone

30. Gastric FB - Cloth

31. Gastric FB - Rock

32. Small Intestine • Duodenum – fixed along right side • Jejunum and ileum – position varies • Normal width = < 3* last rib width • Contains both air and fluid • Can not determine wall thickness • Peyer’s patches, string of pearls

33. Small Intestine Obstruction

34. Intestinal FB’s

35. Intestinal FB

36. Cecum and Colon • Cecum • mid right abdomen • Comma shaped –may contain air • Not often seen in cats • Colon • Ascending, Transverse, Descending • Normal width = < 5 * last rib width

37. Colon

38. Megacolon

39. Megacolon – Why?

40. Beach Sand

41. Urinary Bladder • Dog – caudal abdomen or pelvic • Cat – always intra-abdominal • Vary in size (empty to very distended) • Bladder wall changes can not be determined on radiographs

42. Urinary Bladder • Change in Opacity • Mineral • Cystic calculi • Air • Emphysematous cystitis • Iatrogenic

43. What Do You See?

44. Butt Shot!

45. HBC – Ruptured Bladder

46. Prostate • Usually well visualized in intact males • Should be symmetrical with smooth margins • Enlarged if • > 50% of pelvis inlet width (VD) • >70% of sacro-pubic distance (lateral)

47. Prostate • Enlargement • Hypertrophy • Neoplasia • Prostatitis • Abscess • Paraprostatic cysts • Mineralization

48. Prostatic Adenocarcinoma

49. Pancreatitis • The pancreas is not normally seen • Increased density and decreased serosal detail in the right cranial quadrant • Duodenum may be persistently distended with gas (sentinel sign) • Duodenum can be pushed to the right and pyloroduodenal angle is increased

50. Adrenal Glands • Seen only when enlarged or mineralized • Enlargement • Pheochromocytoma • Cortical carcinoma • Adenoma • Adrenal mineralization • Dystrophic mineralization of tumors • Mineralization of non neoplastic adrenals (cats)