Transcript Diagnostic Imaging of Horses

Diagnostic Imaging of
Horses
LACP
Chapter 7
Pages 147-175
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.
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.
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?
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
Anatomic Direction
• Femur tibia/fibula
– Cranial - Caudal
• Tarsus - digits
– Dorsal Plantar
The five Routine views
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Lateromedial (Lateral)--Extended
Lateromedial (Flexed lateral)--Flexed
Dorsopalmar (DP)
Dorsolateral-palmaromedial oblique
(DLPMO)
• Dorsomedial-palmarolateral oblique
(DMPLO)
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
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Owners name
Patient name / number
Name of clinic / Location
Date of exam
Limb examined (RF, LF, RH, LH)
The Equipment:
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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!
Radiograph Cassette holder
Film cassette in cassette holder
Portable radiograph machine
Portable radiograph machine
Portable radiograph machine
with a light collimator
Wood and Plexiglas positioning
block for the equine foot.
Position of the cassette for
stand-on radiographic views
Position of the foot and cassette
for stand-on views of the foot.
Slots provide additional
support for film cassettes.
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.
Here’s the setup! Without the
horse of course…
Generally you are about 30-40 inches (80 cm.)
away from the patient.
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!
Horseshoes interfere with
interpretation of radiographs
Hoof anatomy
Lateral
• Horse is weight
bearing
• Cassette holder is
used
• X-ray beam is
perpendicular to
the middle carpal
joint
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!
Dorsopalmar
• Weight bearing
• X-ray beam
centered at
middle carpal
joint
• Cassette parallel
to the palmar
aspect of the limb