1. Diagnostic Imaging of Horses
LACP
Chapter 7
Pages

2. Diagnostic Radiology Very similar to small animals
Principles are the same as in small animals
Large animal radiology is very unique due to the conformation of the patient and the fact that most radiographs are performed on a standing, awake patient.
The temperament of the animal can hinder the ability to position a patient for ideal film studies.

3. Safety: “Fear Factors”
Injured horses-painful
Strange noises
Strange things touching the horses; for example, ideally the film cassette should be placed to contact the patient’s skin.
Personnel and equipment are in vulnerable positions with a patient that is often suspicious of the situation.

4. Safety: Personnel Involved
Move slowly and speak in a low calm voice
Do not make loud crashing noises
Let the horse know that you are getting ready to do something to him/her. Gently rub the area of interest-touch it lightly if it is not injured.
PPE-Wear these items! What are they?

5. Just how many people does it take to take a radiograph?
One person to tend to the horse’s head-your restrainer
One person to operate the radiograph machine
One person to hold/position the film cassette
That’s right-this equals 3

6. Anatomic Direction Femur - tibia/fibula Tarsus - digits
Cranial - Caudal
Tarsus - digits
Dorsal - Plantar

7. The five Routine views Lateromedial (Lateral)--Extended
Lateromedial (Flexed lateral)--Flexed
Dorsopalmar (DP)
Dorsolateral-palmaromedial oblique (DLPMO)
Dorsomedial-palmarolateral oblique (DMPLO)

8. Radiograph labeling Standard convention Marker is placed
Cranial / Dorsal
Lateral
Be sure to “flash” the cassette
Permanently identifies film as belonging to a certain patient
Owners name
Patient name / number
Name of clinic / Location
Date of exam
Limb examined (RF, LF, RH, LH)

10. The Equipment: Radiograph machine Caliper Radiograph cassette holder
Cassette/film
Play-doh or putty
Positioning blocks
Processor to develop the film
Chemical Sedation/Restraint devices
PPE
Time and patience!

11. Radiograph Cassette holder

12. Film cassette in cassette holder

13. Portable radiograph machine

14. Portable radiograph machine

15. Portable radiograph machine with a light collimator

16. Wood and Plexiglas positioning block for the equine foot.

17. Position of the cassette for stand-on radiographic views

18. Position of the foot and cassette for stand-on views of the foot.

19. Slots provide additional support for film cassettes.

21. Packing of the grooves of the sole to prevent artifacts created by the air pockets of the hoof. These artifacts can sometimes mimic fracture lines and may obscure true lesions. Do not over pack. Always be sure to clean the hoof wall, sole and recesses of the frog. Hoof picks, soap, water and a brush may be needed.

22. Here’s the setup! Without the horse of course…

23. Generally you are about 30-40 inches (80 cm.)
away from the patient.

25. Removal of the shoe is recommended but is expensive to remove and place back on the horse. Many owners will object to this. Always obtain owner consent before removing shoes!

26. Horseshoes interfere with interpretation of radiographs

27. Hoof anatomy

28. Lateral Horse is weight bearing Cassette holder is used
X-ray beam is perpendicular to the middle carpal joint

29. Flexed Lateral Foot is elevated Carpus held in flexion
X-ray beam is centered at middle carpal joint
Tendency to shift carpus toward midline
Hands are close enough for scatter radiation--use gloves!

30. Dorsopalmar Weight bearing X-ray beam centered at middle carpal joint
Cassette parallel to the palmar aspect of the limb