1. Abdominal Positioning
RVT: Chapter 18

2. Learning Objectives: Abdomen & Soft Tissue
Understand radiographic concerns associated with the abdomen
Properly and safely position a small animal for two common radiographic views, with the ability to:
Measure accurately
Center the x-ray beam appropriately
Image with correct borders
Properly position the patient
Understand alternate views
Identify normal abdominal anatomy, including major differences between cats and dogs

3. Small Animal Abdomen: Anatomy

4. SA Abdomen: Radiographic Concerns
Similar tissue densities & multiple organ systems
GI gas & fat provide contrast
Generally use a higher kVp and lower mAs needed
Try for higher _____ and lower ______ to shorten exposure
May need two films per view in deep-chested dogs
Can average measurements on smaller animals
Heel effect!
Contrast media often required

5. SA Abdomen: Radiographic Concerns
Use nonmanual restraint whenever possible
Wear PPE at all times
Measure in the position to be radiographed
Thickest part: Usually last rib (T_ _ )
Expose at end of _______________ (during pause)
Allows maximum space for abdominal organs

6. Radiographing the Abdomen: Positioning

7. Lateral Abdomen – Dog vs Cat

8. Abdominal Positioning: Lateral
Lateral recumbency
Sternum & spine on same plane
___________ to the image receptor
Aim is symmetry & superimposition
Forelimbs pulled cranially; hind limbs caudal
Foam wedge needed?
Right lateral separates kidneys better

9. Abdominal Positioning: Lateral
Left lateral is preferable in vomiting patients
Gas in pylorus can highlight a foreign body
Left lateral may be required in contrast studies
L/R marker at ventral aspect
Collimation must include:
Cranial margin- Full diaphragm and heart apex (T7)
Caudal margin- Greater trochanter
(coxofemoral joint)

10. Liver Mass

11. Gastric Trichobezoar

12. Gastric Dilitation & Volvulus (GDV)
“Double bubble”

13. Lateral Positioning: Confirmation
Superimposition of:
Vertebral foramina
Spinous processes
Coxofemoral joints
Ribs

14. Abdominal Positioning: Ventrodorsal
Measure at about 13th rib
Dorsal recumbency
Restraint device?
Must pull forelimbs cranial; hindlimbs in natural position
Imagine a straight line connecting nose & caudal midline
* DV can be used as alternative if animal is compromised by VD
Dog
Cat

15. Abdominal Positioning: Ventrodorsal
Collimation must include:
Cranial margin- Full diaphragm (T9)
Caudal margin- Greater trochanter
(coxofemoral joint)
Central ray positioning differs between cat & dog
Central beam is slightly more caudal on cats
Ensure marker is on the correct side!

16. V/D Positioning: Confirmation
Spinous processes are aligned in the center of vertebral bodies
Sternum and spine are super imposed
Abdominal symmetry

17. Abdomen: Lateral Oblique
Used to evaluate male urinary/reproductive tracts
Better visualization of penis
Free leg must be retracted out of the field of view!

18. Abdomen: Modified Lateral
Used when radiographing the entire male urinary tract
Hind limbs pulled cranially so they don’t overlap urethra or bladder
*Used mainly for contrast

19. Abdominal Anatomy: Notes
Fat animals image better than emaciated ones
Fat serves as a contrasting opacity
Many normal structures hidden radiographically
Ureters, urethra, adrenals, pancreas, etc.
Abnormalities can make them visible!
Liver – very large organ!
Normally lies within ribs
Best evaluated via lateral radiograph
Stomach –
Normally within rib cage (include caudal ribs in radiograph)
Food images as granular material of mixed opacity
Can be 2-3 times larger after a meal
Gas rises and fluid moves with gravity

20. Chocolate Ingestion

21. Abdominal Anatomy: Notes
Spleen- usually to the left of midline; lateral to the stomach
Kidneys- right is more cranial than left
Should find the left within the lumbar spinal region
Bladder- very caudal in the abdomen

22. Bladder Stones