MSK radiographs Flashcards
what technique for MSK and how many views? what views?
low kVp, high mAs (increase contrast)
2 mandatory views for SA, 4 min for LA, can be upwards of 8 for some LA radiographic studies
LA: lat/medial, Cr/Cd, DP
SA: VD, DV, Cr/Cd
tell me about labeling for MSK
named by where beam enters/exits
LA: always lateral; if no lat, cranial or dorsal
SA: label applied to surface touching plate
is there normally a space between bones in a joint? why or why not?
yes
cartilage is there, and because of high H2O content, it makes it look like ST
ulna is _____. fibula is _____.
lateral (both)
you have a radiograph of a dog foot and you see weird black lines at the bottom. is this normal?
yes normal
this is the foot pad
on the canine manus, the sesamoids at the MC-phalangeal joint is _____.
palmar
in pelvic MSK radiographs, the limb that is _____ placed is the one against the plate.
cranially
how do you take an image of a particular bone? what about a particular joint?
bone: bone of interest + proximal & distal joints
joint: joint in center, 1/3 of adjacent diaphyses
what is an apophysis?
normal developmental outgrowth of a bone which arises form a separate ossification centre, and fuses to the bone later in development
what are nutrient foramen?
little holes in bone where vessels travel into the bone. they are normal!
what are the Roentgen (idk how to spell that lol) signs for MSK? think about your ABCD’S
Alignment
Bone
Cartilage
Device
Soft tissues
what is alignment of bone? what is normal?
the appearance of the way the bones line up at the joint and along the bone
normal = draw a line down the middle of one bone, draw another line down the middle of another bone or joint, whatever is touching the first bone, the angle between the two lines should be 1-3 degrees
how do you know if an implant device is failing?
bone becoming more Lucent near the implant = bad (irregular bone density = lysis)
bad alignment (depends on time of implant/radiographs, like how many weeks after sx is this?)
if your PE is highly suggestive of a fx, yet radiographs are not revealing, what should you do?
consider rechecking images in 7-10 days, as during healing process normal resorption of fx margins will occur that will enlarge fx lines enough to allow visualization of its margin
trust your PE!
tell me about the 5 radiographic stages of secondary bone healing. with dates pleeeeeease
Stage 1: sharp margins, good definition, ST swelling variable, w/ minimally displaced fx’s the margins are hard to visualize
Stage 2: 5-10 days post-fx, resorption of fx margins (margins soften), fx gap widens,
Stage 3: 10-20 days after reduction, callus formation (endosteal + periosteal), fx gap narrows
Stage 4: >30 days after reduction, fx disappears gradually, callus remodelling
Stage 5: > 3 months, continued remodelling of callus, trabecular pattern may develop w/I callus, cortical shadow appears, cortical remodelling along lines of stress
what are the 3 complications with fx healing?
malunion: healed with abnormal alignment (poor reduction, movement)
delayed union: slow to heal
non-union: no evidence that healing is progressing
what is a sequestrum? what is an involucrum? what is a cloaca (in terms of a sequestrum)?
sequestrum: non-viable bone fragment
involucrum: parent bone bed, sort of darker area/ring around sequestrum
cloaca: draining tract
aggressive bone lesions are typically the result of _____.
neoplasia
how do you differentiate between aggressive and non-aggressive bone lesions?
aggressive: cortical destruction, periosteal reaction that is not smooth, zone of transition not distinct
non-aggressive: no cortical destruction, no periosteal reaction, zone of transition sharp
the more solid and smoothly marginated periosteal reaction, the less aggressive bone lesion
what are the 3 types of lysis? tell me then in order of least to most aggressive
geographic
moth eaten
permeative
what is geographic lysis?
margins are well defined with clear demarcation of the adjacent normal bone
typically associated with less aggressive disease processes
tell me about subchondral cyst-like lesions
seen in horses of any age, typically round-oval shaped geographic areas of lucency with sclerotic rim
most common in stifle joint
subchondral surface of femoral condyle can be flattened at level of cyst
most common in the weight-bearing area of the medial femoral condyle