Lameness (Yr 4) Flashcards
(25 cards)
what is a major artifact that could happen when radiographing the musculoskeletal system?
geometric distortion
what is geometric distortion?
structures towards the edge of the collimation are not truly parallel to the beams so it will be distorted (lengthened or shortened) on the image
what are the rontgen (radiographic) signs?
number
size
shape (and margination)
location
opacity
what are the three specific assessments to make looking at musculoskeletal radiographs?
soft tissue (swelling/loss)
bones
joints
what assessments should be made about the bones in musculoskeletal cases?
alignment, shape, length
periosteal reaction, cortical lysis, defects
endosteal/medullary changes
physes (growth plates)
what can cause reduced size of soft tissues?
atrophy (focal) - chronic lameness, neurogenic, fibrosis/scaring
weight loss (general)
what can cause a focal increase in soft tissue size?
trauma
abscess/seroma
granuloma
neoplasia
what can cause a diffuse increase in soft tissue?
oedema
cellulitis/vasculitis
diffuse neoplasia
what are the parts of a long bone?
epiphysis, metaphysis, diaphysis
what are the layers of long bone?
periosteum
cortex
endosteum
medulla
what changes can be seen with bones on radiographs?
reduction in opacity
periosteal reaction (bone surface)
how can focal bone loss (lysis) be categorised on radiographs?
geographic
moth-eaten
permeative
what is geographic bone lysis?
homogenous reduction in opacity
what is moth-eaten bone lysis?
lots of coalescing areas of lysis
what is permeative bone lysis?
slow lysis of a particular area
what is the least to most aggressive categories of bone lysis (loss)?
geographic (least)
moth-eaten
permeative (most)
how can periosteal reaction (bone surface) be described from inactive/benign to active/aggressive?
smooth
rough
brush border
palisading
spicular
sunburst
amorphous
what do you need to critically assess when looking at joints?
soft tissue swelling
joint space width
subchondral bone opacity
oestophyte/enthesophytes
periarticular mineralisation
what is the only joint that you can definitively say from a radiograph if there is effusion within the joint or soft tissue swelling around it?
stifle (due to infrapatellar fat pad)
how can cartilage around a joint be visualised on radiographs?
contrast studies (or use another imaging modality)
what are some causes of subchondral bone changes?
osteochondrosis (main one)
aseptic necrosis (femoral head)
septic arthritis
erosive arthritis
trauma (avulsion fracture)
soft tissue neoplasia
osseous cyst like lesions
osteoarthritis (if severe)
what are some radiographic changes seen with osteoarthritis?
soft tissue swelling/effusion
periarticular new bone (at predictable sites)
subchondral sclerosis
narrowed joint space
(evidence of primary disease process)
what are the predilection sites for oesteochondrosis?
caudal aspect of humeral head
medial part of humeral condyle
lateral femoral condyle
medial trochlear ridge of talus
what are the predilection sites for osteosarcomas?
proximal humerus
distal radius/ulna
distal femur
proximal tibia
