Introduction to Abdominal Radiology

1. Introduction to Abdominal Radiology Meghan Woodland, DVM

2. Indications • Vomiting/Diarrhea • Abdominal Pain • Hematuria • Abdominal Mass/Distension • Tenesmus (Pain on Defecation)

3. Technical Factors • Abdomen has low inherent contrast • Lower kVp • Higher mAs • Collimation • High amount of scatter • Use grid (if patient is >10-11cm thick) • Take exposure on expiration

4. Positioning • VD and R lateral views • Include from diaphragm to pelvic inlet • Fore limbs pulled cranially • Hind limbs pulled caudally • Additional views as necessary

5. Radiographic techniques: the dog  By Joe P. Morgan, John Doval, Valerie Samii

6. Radiographic techniques: the dog  By Joe P. Morgan, John Doval, Valerie Samii

8. Improper positioning. Could miss a diaphragmatic hernia.

9. UnpreparedAbdomen

10. “Butt Shot” – Urethral Calculi

11. Interpretation of Abdominal Radiographs • Liver • Spleen • Kidneys • GIT (Stomach, SI, Cecum, LI) • Bladder • Prostate • Extra-abdominal structures

12. Structures Not Normally Seen • Gall bladder • Pancreas • Adrenals • Ovaries • Uterus • Ureters • Lymph Nodes • Mesentery • Vasculature

13. Liver • Lateral view: • Caudo-ventral margin angular • Should not extend beyond the costal arch • Normal gastric axis parallel to ribs or perpendicular to spine • VD view: • Liver margins not well seen • Long axis of stomach perpendicular to spine

15. Over-inflation of chest gives false appearance of enlarged liver

17. Spleen • Size is subjective • Lateral view: • Tail of spleen visible, but position varies • Not usually seen on this view in cats • VD view: • Head of the spleen is visualized • Caudo-lateral to stomach fundus • Cranio-lateral to left kidney • Cats : often seen lying along the left body wall

18. Dog – Lateral View

19. Dog – VD View

20. Cat – Lateral View

21. Cat – VD View

22. Kidneys • Right located cranial to left • May be difficult to see in young or emaciated animals • Size (only evaluated on VD view) • Dogs: 2 ½ to 3 ½ times the length of L2 • Cats: 2 to 3 times the length of L2

23. Dog – Lateral View

24. Dog – VD View

25. Cat – Lateral View

26. Cat – VD View

27. Gastrointestinal Tract • Stomach • Caudal to liver • Gastric Axis • Less than 3 ICS wide on lateral view • VD: • Dog = U-shaped • Cat = J-shaped

29. “U-Shaped” Stomach Dog – VD View

30. “J-Shaped” Stomach Cat – VD View

31. Gastrointestinal Tract • Small Intestine • Size: Width less than 3 times the last rib • Duodenum • Fixed along the right side • Extends caudally from the pyloric region of the stomach • Jejunum/Ileum • Position Varies • Mid-ventral abdomen

33. Gastrointestinal Tract • Cecum • Comma shaped • Mid, right abdomen • Not often seen in cats • Large Intestine • Ascending, transverse and descending colon • Size: Width less than 5 times the last rib

34. Cecum – VD View

35. Cecum – Lateral View

36. Megacolon in a Dog Descending colon Transverse Colon Ascending Colon

37. Transverse Colon Ascending Colon Descending colon Contrast Study

38. Bladder • Size varies • Dog: • Oval to ellipsoid • Caudal abdomen or pelvic • Cat: • Ellipsoid • Always intra-abdominal (elongated bladder neck)

39. Bladder more pelvic Dog – Lateral View

40. Long Bladder Neck Cat – Lateral View

41. Prostate • Intact males ++ • Caudal to bladder • Symmetrical with smooth margins • Size: • Lateral: Less than 70% of sacro-pubic distance • VD: Less than 50% of pelvic inlet width

43. Extra-Abdominal Structures • Soft Tissues • Bone (Spine, Pelvis, Hind limbs) • Diaphragm • Thorax (if visible)

45. Decreased Abdominal Detail • Inability to distinguish organs • Causes: • Young Animals * • Emaciated Animals • Peritoneal Fluid • Inflammation (Peritonitis, Pancreatitis) • Carcinomatosis  Normal finding

46. Emaciated Cat

47. Abdominal Fluid

48. Fun Slides How Many Babies?

49. Where is the foreign body?

50. What organs are mineralized?