Small animal positioning Flashcards
Abdomen
Two views are standard
Right Lateral (R Lat)
Unless right side down is contraindicated
Ventrodorsal (VD)
Label (L/R) goes towards the hips
Measurement taken at the diaphragm
Use Anode Heel Effect to your advantage
Thickest part of patient at cathode – helps reduce density differences
Use grid to have better detail
Reduces scatter fogging
Attempt for exposure at expiration*
Parameters are entire diaphragm and caudal aspect of heart up to and including greater trochanters of the femurs
Abdomen lateral view
Head is in natural position
Forelimbs pulled cranially; hind limbs pulled caudally
Stretching them slightly
To prevent rotation a foam pad can be placed between limbs or they can be held slightly apart
Keep sternum and vertebrae at the same plane
Can use foam wedge under sternum
Abdomen ventrodorsal view
Head pulled forward or towards the table
Forelimbs pulled forward
Hind limbs left in natural position (frog-legged) or pulled caudally
V-trough can be used to keep patient from rotating
Place trough under thorax not abdomen
Thorax
Three views are standard
Right Lateral (R Lat)
Left lateral (L Lat)
Dorsoventral (DV) if examining the heart OR Ventrodorsal (VD) if examining the lungs
DV = Heart lies in natural position
Label (L/R) placed towards head
Measure over the heart
Use Anode Heel Effect to your advantage
Use a grid for better detail
Exposure should be taken on maximum inspiration
Critical when examining lungs
Sedation decreases inspiration capacity so can mask some pathologies
Parameters are thoracic inlet up to and including the entire diaphragm
Can use same positioning aids as Abdomen
Thorax centering
Pull forearms as far forward as you can then feel the caudal aspect of the scapula
If you place the transverse line of the collimator cross hairs right behind the caudal aspect of the scapula you will be centered over the heart
Thorax lateral views
Head in natural position
Forelimbs pulled forward and hind limbs pulled backward
Gentle pressure applied to stretch patient
To help avoid rotation, limbs should be separated
Want to pull forelimbs and scapulae off the lungs
Spine and sternum should be in the same plane
Trying to superimpose ribs
Thorax VD/DV
Head in natural position
Any turning of the head will cause rotation in the spine
Forelimbs pulled cranially and hind limbs pulled caudally
Gentle pressure applied to stretch patient
Ensure limbs are being pulled evenly to avoid rotation
Spine should have “tear drops” if straight
Spine and sternum should be in the same plane
Straight positioning is important as rotation can change the shape of the heart
Shoulder
Requires two views
Lateral
Caudocranial (CC)
Measure over manubrium when animal is in position
Center beam on joint space of the shoulder
Shoulder lateral
Affected limb is down
Head and neck extended dorsally
Top leg is pulled up and caudally
Affected limb pulled down and cranially
Shoulder joint moved off sternum
Same positioning will be used for humerus
Shoulder caudocranial
Patient is in dorsal recumbence
Measure through the chest – thickest part
Pull patient’s head slightly to opposite side so view unobstructed
DO NOT turn head or will cause thorax to rotate and will obstruct view
Pull front limb cranially
Use elbow to ensure is CC
Scapula lateral view
Lateral View (different than text)
Place in lateral recumbence with affected side down
Hold both legs at elbow
Push lower limb (affected) dorsally while pulling upper limb ventrally
Measure through chest – thickest part
Humerus
Requires two views
Lateral – same as for shoulder
Caudocranial (similar to shoulder) or craniocaudal
Measure at proximal humerus at level of shoulder joint
Center the beam at center of humerus shaft
If limb is too painful can position craniocaudally
Abduct limb slightly from body
Measure through chest
Use elbow to ensure CC
Elbow
Requires two views
Lateral
Craniocaudal
Measure over the joint
Center the beam at center of joint
Entire olecranon must be included
Elbow lateral
Patient in lateral recumbence – affected side down
Pull top limb caudally
Most cases you can allow affected limb to stay in relaxed natural position
Elbow should be flexed between 45 and 90 degrees depending on veterinarian preference
Grasp the carpus to ensure limb is not oblique
Elbow CC
Craniocaudal
Place in sternal recumbence with affected limb extended cranially
Patient’s head pulled straight up so nose is pointing at ceiling (dorsally)
Ensure DO NOT twist head as can oblique elbow
Angle tube head 5-10 degrees to compensate for angle at elbow*
Radius and ulna
Requires two views
Lateral
Craniocaudal
Measure at mid shaft of radius and ulna
Radius and ulna lateral
Place in lateral recumbence, affected side down
Most cases can allow affected limb to be in relaxed natural position only grasping carpus to prevent obliquing
Center mid shaft of long bones and include both joints
Can use gauze at carpus to prevent fingers from being in primary beam
Radius and ulna CC
Place in sternal recumbence with affected limb extended cranially
Patient’s head pulled straight up so nose pointing at ceiling (dorsally)
Ensure DO NOT twist head or will oblique elbow
Can use gauze at carpus to prevent fingers from being in primary beam
Metacarpus and digits
Requires four views
Lateral
Dorsopalmar
Dorsopalmar Medial-Lateral Oblique
Dorsopalmar Lateral-Medial Oblique
Obliques are 45 degrees from dorsopalmar
Obtained by placing hand behind elbow of affected limb to extend and then leaning entire patient either away from or towards you
Make sure all toes and all of carpus included
Carpus
Same as metacarpus and digits
Lateral
DP
Dorsopalmar Medial-Lateral Oblique
Dorsopalmar Lateral-Medial Oblique
Collimate down to only the carpus
Pelvis lateral
Lateral recumbence, affected side down
Center on pelvis
Measure at level of trochanter or thickest part
Include entire pelvis and portion of lumbar spine and entire stifle
Rule of Thumb
Top limb caudal, bottom (affected) limb cranial
Will separate hip joints off each other and allow to determine which femur is which
Pelvis VD frog leg view
ONLY used if extended legs contraindicated
Patient in dorsal recumbence
Allow limbs to fall into natural position and hold metatarsus together to ensure symmetry
Pelvis VD extended hips
Femurs parallel to each other
Both patellae centered between the femoral condyles
Done by grasping tarsi and rotating limbs medially (pigeon-toe)
Ensure pelvis not rotated
Obturator foramen, hip joints, os coxae should all appear as mirror images
Tail should be straight
Not curled under either femur
Include top of iliac wings (last two lumbar vertebrae) and stifles
Extended hips for OFA
OFA – Orthopedic Foundation for Animals
Patient must be minimum of 2 years in order to be certified Dysplasia free
Symmetry and precision are vital
Sedation may be required
Following information MUST be PERMANENTLY imprinted on film:
Full registered name
Full date of birth
CKC or AKC number
Date of radiograph
Owner’s name
Veterinarian or Clinic name
Femur lateral
Measure at mid shaft when patient in position
Lateral recumbence with affected side down
Top limb pulled towards ceiling out of beam path
Use tarsus to ensure limb is parallel to cassette
Can use hand or foam under tarsus to do this
Include coxofemoral joint to stifle
Femur CC
Can be in dorsal recumbence, sitting on butt, or can do cross table*
Affected limb pulled caudally
Use tarsus to ensure straight
Patella should be between femoral condyles
Include proximal 3rd of tibia and entire coxofemoral joint
Magnification and/or loss of detail common due to OFD
Stifle lateral
Lateral recumbence with affected limb down
Natural, slightly flexed position
Ensure tibia parallel to table
Can use foam under tarsus
Stifle CC
Dorsal recumbence with affected leg extended caudally
Include proximal 3rd of tibia and distal 3rd of femur (make even with stifle centered)
Patella should be between femoral condyles
Distortion and magnification can be reduced by having animal sit on their butt
Tibia and fibula lateral
Lateral recumbence with affected side down
Opposite limb pulled up towards ceiling and away from body
Let limb go into natural position
Ensure tibia parallel to table for true lateral
Center on long bones and include both joints
Tibia and fibula CC
Dorsal recumbence with affected limb extended caudally
Use pressure on femur to extend limb properly
Use gauze at tarsus to prevent fingers from being in primary beam
Use calcaneus of tarsus to ensure limb true CC
Ensure tail not under affected leg
Include entire tarsus and stifle
Tarsus
Requires four views
Lateral
Dorsopalmar
Dorsopalmar Medial-Lateral Oblique
Dorsopalmar Lateral-Medial Oblique
Collimate down to only tarsus
Obliques are 45 degrees from DP
Can sit patient on butt and lean towards/away from you to get appropriate angles
Metatarsus and phalanges
Requires four views
As per tarsus
Include all toes and all of tarsus
Spine
Best to have patient sedated
Two required views
Lateral
Ventrodorsal
Use of grid increases detail and contrast
Ensure animal parallel to table, use foam wedges under nose, neck and lower abdomen
May need to use small lead numbers to identify locations on larger breed dogs
Skull
Best to have patient sedated
Symmetry used to interpret films
If not parallel then may look as though something going on due to increased/decreased densities
Routine and bullae series
Grid use will increase detail and contrast**
Include tip of nose to base of skull
Routine skull
Lateral View
Superimpose one eye over the other
Center on angle of jaw
If straight radiograph shows:
Only one frontal sinus
Teeth are superimposed (look blurry)
Bullae are superimposed
Mandible superimposed
Dorsoventral or Ventrodorsal View
Center at angle of jaw
Ensure hard palate parallel to table
Should see symmetry of two halves of the skull
Bullae
Lateral View
Measure highest point of zygomatic arch
Center on base of ear
Dorsoventral or Ventrodorsal View
Measure at highest point of cranium – just caudal to lateral canthi
Center on D/V midline between ears and at base of ears
Open-mouth Rostrocaudal (rostral 10 degree ventral-caudodorsal)
Feline: closed-mouth rostral 10-degree ventral-caudodorsal
Lateral Oblique View, affected side side UP
Lateral Oblique View, affected side DOWN
Oblique skull
Center on area of interest
Angle 20-30 degrees from lateral for jaws
Angle 45 degrees for bullae and TMJ
Use a sponge/wedge
Need views of both left and right side in order to compare
Lead letter placed closest to object being highlighted
