Test 2: 16 large animal xray Flashcards
5 steps to interpret if you have good large animal xray
- Adequate quality study
- Adequate number of views
- Identification of abnormalities
- Recommendations
- Interpretation of abnormalities
* Make diagnosis vs list differential diagnoses
* Determine significance
how many views for large animal
4 need obliques to see small details
changes indicate bone damage
shape:—
size: —
shape: contour abnormality, malalignment, subluxation
size: soft tissue swelling
roentgen signs: size, shape, opacity, margination, number
changes indicate bone damage
opacity:—
margination: —
opacity: increased or decreased bone density
margination: irregular periosteal proliferation, subchondral irregularity/bone loss
roentgen signs: size, shape, opacity, margination, number
soft tissue and — have the same opacity
fluid
4 ways to describe bone abnormality
- what is the abnormality
- where is it
- one bone or multiple bones
- localized, diffuse, multifocal
disorder of the connective tissues between bones and tendons or ligaments
enthesopathy
why is medullary cavity less opaque then cortical bone
fatty= less opaque= less white
geographic lysis can be caused by
bone cyst
subcondral injury
moth eaten or permeative lysis can be caused by
more aggressive destruction
osteomyelitis
neoplasia
osteophytosis
“bone spurs”, are outgrowths of bone tissue that form around damaged joints
severe osteophytosis
(bone spur)
periarticular new bone
— bone pathology is likely to be painful no matter the location
“Aggressive”
rapidly changing= normally caused by sepsis or neoplasia
— bone pathology may or may not cause lameness depending on its location and other regional factors
”Benign”
joint space has thinned= loss of cartilage
based on location is that a cyst?
no
that is where collateral ligament attaches= enthesis
need to know attachment points to rule in and out diagnosis
if this circle was on the long bone it would prob be a bone cyst
well defined but irregular periarticular proliferation
caused by injury to intracapsular soft tissue
this is where joint capsule attaches
proliferation of periosteum secondary to inflammation of joint capsule
subchondral bone plate thickening/ trabecular sclerosis
demineralization/lysis of the subchondral bone plate
what shows osteoarthritis
- Subchondral sclerosis +/- lucency
- Joint effusion/capsular thickening (soft tissue swelling)
- Periarticular new bone formation
- Joint space narrowing (cartilage loss)
early stage septic arthritis/physitis will show
Joint effusion/capsular thickening (often marked)
Subchondral lysis
What is the body part/region included?
Which of the images or sets of images is abnormal and which set is normal (A vs B)?
stifle
B
Describe the lesion(s) on the abnormal set of images using orthopedic Roentgen signs
Include names of the bones and anatomical directions (e.g. dorsal vs palmar, medial vs lateral, proximal vs distal, if applicable)
Ill-defined osteolysis of proximolateral tibial epiphysis and metaphysis
Moderate adjacent lateral soft tissue swelling
roentgen signs: size, shape, opacity, margination, number
Is the primary lesion radiographically aggressive or benign?
Would you expect this lesion to cause lameness?
aggressive: ill defined margins
yes →aggressive lesions and associated with joint (subchondral/epiphyseal location)
What is the body part/region included?
Which of the images or sets of images is abnormal and which set is normal (A vs B)?
R metatarsophalangeal joint (aka RH fetlock)
A
Which of the images or sets of images is abnormal and which set is normal (A vs B)?
Describe the lesion(s) on the abnormal set of images using orthopedic Roentgen signs
Include names of the bones and anatomical directions (e.g. dorsal vs palmar, medial vs lateral, proximal vs distal, if applicable)
Well-defined ovoid lucency within distal third metatarsal diaphysis, just proximal to proximal sesamoid bones, medial parasagittal to midline
Thin rim surrounding sclerosis
Is the primary lesion radiographically aggressive or benign?
Would you expect this lesion to cause lameness?
benign (well-defined lucency, the surrounding sclerosis suggests this was not a rapid process (bone has time to remodel over time)
No/unlikely (benign lesion and not associated with joint)
where is a horse’s knee and what is the equivalent human joint
knee is the front leg of horse between ulna and radius and the carpal joints
equal to wrist of human
where is the hock of a horse
back leg- after tibia and fibula and before cannon bone
equal to ankle in a human
a horse’s cannon bone is –
metacarpals/ metatarsals
is below the hock( back leg) or the knee(front leg) and befor the fetlock (metacarpal-phalangeal joint)
