MSK radiographs Flashcards by Madeleine Gauthier

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

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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

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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

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ulna is _____. fibula is _____.

lateral (both)

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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

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on the canine manus, the sesamoids at the MC-phalangeal joint is _____.

palmar

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in pelvic MSK radiographs, the limb that is _____ placed is the one against the plate.

cranially

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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

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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

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what are nutrient foramen?

little holes in bone where vessels travel into the bone. they are normal!

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what are the Roentgen (idk how to spell that lol) signs for MSK? think about your ABCD’S

Alignment
Bone
Cartilage
Device
Soft tissues

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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

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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?)

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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!

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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

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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

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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

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aggressive bone lesions are typically the result of _____.

neoplasia

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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

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what are the 3 types of lysis? tell me then in order of least to most aggressive

geographic
moth eaten
permeative

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what is geographic lysis?

margins are well defined with clear demarcation of the adjacent normal bone
typically associated with less aggressive disease processes

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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

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_______ is seen with benign joint disease, such as degenerative joint disease, as well as subchondral sclerosis secondary to chronic stress remodelling

increase subchondral bone opacity

what is moth eaten lysis?

multiple small geographic areas of lysis
coalescing regions of ill-defined lysis

what is permeative lysis?

ill-defined, long zone of transition to normal bone multiple pinpoint foci of lysis

what is the zone of transition?

graduation for disease bone to normal bone

true or false: always classify the most aggressive periosteal response seen on the lesion

true

tell me the types of periosteal reaction, from least to most aggressive

solid lamellated/onion skin columnar/palisading star burst / sun burst amorphous

what is solid periosteal reaction?

periosteal proliferation and mineralization far outweighs osteoclastic or other one resorptive activity

what is Codman's triangle?

a distinctive triangular form of periosteal reaction seen when an aggressive bone lesion grows faster than new periosteum can be ossified. only the periosteum at the very margin of the lesion has time to ossify, creating a triangular lip of new bone. the periosteum sort of lifts up and creates a triangle suspect osteosarcoma or other kind of tumor

what is columnar/palisading periosteal reaction?

the periosteum sort of grows out of the bone in horizontal lines/columns

what is a star burst/sun burst periosteal reaction>?

periosteum radiates outwards from bone, and there's a halo of lighter stuff around it, like a sun burst

what is amorphous periosteal reaction?

no structure, ill-defined, just kind of bleh

what are the radiographic markers of joint disease?

increased synovial vol effusion subchondral bone changes intraarticular calcification joint malformation

many times with cruciate ligament injury, the only radiographic finding will be _____. other radiographic findings include _____ formation and ______ ______ of the ______. Occasionally a(n) ________ fracture involving the cruciate ligament can be seen.

joint effusion osteophyte cranial displacement of the tibia avulsion

What is osteochondrosis? what does it result in? common signalment? what bad disease can occur due to this?

issues with endochondral ossification leading to epiphyseal cartilage necrosis, associated with focal necrosis and ischemia leading to chondromalacia (if vascular bed doesn't bypass necrotic region) results in joint mice common cause of lameness in young growing large breed dogs and horses OCD (osteochondrosis dissecans) --> chondromalacia will cause tissues extending from the surface o the cartilage to the subchondral bone. osteochondral fragments can separate from subchondral bone and mineralize

tell me some differences between dogs and horses in terms of osteochondrosis

what are some signs of septic arthritis?

narrowing joint space, subchondral bone lysis, may show gas (Rare)

for skull radiography, very precise ____ and usually _______ in small animals and _____ horses is needed. the skull should be _____, but there is breed variation.

positioning general anesthesia marked sedation symmetrical

tell me about SA skull rad positioning

lateral VD/DV (open mouth, closed mouth, and intra-oral) various obliques rostrocaudal (frontal for sinuses, open-mouth for bullae)

compare and contrast radiography vs CT in skull evaluations

RG: slow and tedious, requires GA (sometimes prolonged), not very sensitive to subtle disease changes, evaluation often equivocal CT: fast, usually done with sedation, very accurate, sensitive, and specific, tremendous aid in ID-ing regions to biopsy or changes that may alter therapy/prognosis

tell me the vertebral column formula for dogs and cats

C7 T13 L7 S3 Cd20-24

tell me the vertebral column formula for horses

C7 T18 L6 S5 Cd15-21

tell me the vertebral column formula for cows

C7 T13 L6 S5 Cd18-20

tell me the vertebral column formula for pigs

C7 T14-15 L6-7 S4 Cd20-23

for spinal rads, ____ or marked ______ is usually required for proper positioning.

anesthesia, sedation

1. every vertebral body is separated by an intervertebral disc EXCEPT which ones? 2. ____ is normally narrower than other cervical disc spaces 3. ____ is the anticlinal disc space - the narrowest disc space in the ____ spine. 4. Cranial to t10-11, there is an _____ ____ that crosses the floor of the vertebral canal - prevent IVDD herniation into canal

1. C1-2, S1-2, S2-3 2. C2-3 3. T10-11, TL 4. intercapital ligament

only disc spaces in/on the _____ of the image are truly representative. why?

center towards the edge of the image, the disc spaces appear artificially narrowed due to beam divergence

tell me the radiographic markers of intervertebral disc disease (IVDD)

1. calcification of the IV disc 2. narrowing of the IV disc space 3. increase opacity of the IV foramen 4. change in size/shape of the IV foramen 5. narrowing of the facet joints

definitive diagnosis of IVDD requires what? how do you get this?

visualization of compression of the spinal cord cross sectional imaging has replaced X-ray myelograms in most regions CT alone is effective with mineralized discs MRI or CT-myelogram often/usually required for non-mineralized disc compression

in a equine carpal DLPMO, which bones will be seen from proximal to distal, and if bones are in the same row, from medial to lateral (from left to right of image)

- radius (ulna is fused) - radial carpal bone, intermediate carpal bone, ulnar carpal bone, accessory carpal bone - carpal 3, carpal 4 - metacarpal 3, metacarpal 4

in a equine carpal DMPLO, which bones will be seen from proximal to distal, and if bones are in the same row, from lateral to medial (from left to right of image)

- radius (ulna is fused) - intermediate carpal bone, radial carpal bone - carpal 3, carpal 2 - metacarpal 3, metacarpal 2

You are taking DP radiographs of an equine forelimb and find that the space between the proximal sesamoids and the proximal phalanx isn't wide enough. what can you do to widen the gap?

put the generator and plate at an angle (like 30 degrees)

what are the radiographic signs of laminitis?

- palmar rotation of distal phalanx from hoof wall (results in thicker dorsal hoof wall) - distal (vertical or sinking) displacement of distal phalanx (results in thinner sole)

tell me the difference between a slab and chip fx how do you definitively diagnose a slab fx?

basically just different sizes of bones. a chip fx is a smaller part of a bone, and a slab fx goes through the whole length of the bone and like one side is broken off you need to do dorsoproximal or dorsodistal view (you need to flex the joint)

in a equine tarsal DLPMO, which bones will be seen from proximal to distal, and if bones are in the same row, from medial to lateral (from left to right of image)

- tibia - (medial ridge of trochlea), talus, calcaneus - central tarsal - 3rd tarsal, 4th tarsal - MT3 (cannon), MT4 (lateral splint)

in a equine tarsal DMPLO, which bones will be seen from proximal to distal, and if bones are in the same row, from lateral to medial (from right to left of this image)

- tibia - (lateral ridge of trochlea), (medial ridge of trochlea), talus, calcaneus - central tarsal - 3rd tarsal, 1st + 2nd T (fused) - MT3 (cannon), MT2 (medial splint)