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64 Cards in this Set
- Front
- Back
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When do you switch from using dorsal/caudal to dorsal and palmar/plantar?
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Distal to the carpus/tarsus
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What are the general steps in evaluating a radiograph?
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(1) check patient info
(2) evaluate patient positioning (3) evaluate radiographic technique (4) ID Roentgen signs (5) Make a radiographic Dx or list of Ddx |
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What are Roentgen signs? Name the 6 different categories.
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def: radiographic abnormalities
(1) number (2) size (3) shape (4) opacity (5) location/position (6) margination/contour |
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What specific things should you evaluate on an orthopedic radiograph?
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(1) physeal closures in relation to age of animal
(2) soft tissues (3) periosteal margins and all cortices (4) periarticular margins and subchondral bone (5) joint capsular attachments (6) joint spaces (7) medullary cavities (8) overall alignment and relationship of bones |
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What Roentgen signs can you see in soft tissue, and where do you look?
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loss of visualization of fascial planes
changes in opacity look at fascial planes and margination of muscle groups |
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What causes loss of visualization of fascial planes in soft tissue?
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edema
hemorrhage inflammation tumor infiltration |
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What causes changes in opacity of soft tissue?
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gas
swelling mineralization |
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What can cause gas in soft tissues?
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open wound:laceration or fracture
gas-producing organisms iatrogenic: post-op or needle puncture |
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What can cause mineralization of soft tissues?
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2 common ones:
-metastatic mineralization -dystrophic mineralization 2 uncommon ones: -idiopathic -neoplastic |
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What is metastatic mineralization?
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mineralization of normal tissue d/t high serum [Ca] and or [P]
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What is dystrophic mineralization?
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mineralization of dead, degenerative, or devitalized tissues
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What is idiopathic mineralization?
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mineralization of soft tissues NOT d/t dystrophic or metastatic etiologies
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What is neoplastic mineralization?
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mineral or bone production by a tumor
(some consider this a separate category) |
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What are the 2 types of soft tissue swelling around or near a joint?
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intracapsular swelling
extracapsular swelling |
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What are some causes of intracapsular soft tissue swelling?
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effusion
soft tissue proliferation: synovial proliferation, neoplasia |
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What are the characteristics of intracapsular swelling?
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conforms to joint margins
swelling will be centered on the joint -structures Cr to joint are pushed more Cr -structures Cd to joint are pushed more Cd in the stifle: infrapatellar fat pad is compressed and displaced cranially (out from joint) |
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What are the Roentgen signs of intracapsular swelling of the stifle?
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infrapatellar fat pad is compressed and displaced Cr
fascial planes Cd to stifle are displaced Cd |
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What are some causes of extracapsular soft tissue swelling?
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edema, hemorrhage, inflammation
ligamentous/tendinous pathology neoplasia |
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What are the Roentgen signs of extracapsular swelling of the stifle?
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patella ligament desmitis
infrapatellar fat pad is displaced Cd fascial planes Cd to stifle are displaced Cr |
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How does bone respond to injury and disease?
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new bone formation
lysis or reabsorption can be a combo |
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How do you characterize osseous lesions? What procedures(s) do you need?
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aggressive vs. non-agressive
active vs. inactive duration radiographs, but you need a biopsy for histopath for a final Dx |
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What are the lag times of different radiographic changes?
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Lytic changes: 5-7d
Productive changes: 10-14d |
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How much bone loss is required before you can see it on survey rads?
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30-60%
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What are the 2 productive radiographic changes of osseous lesions?
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osteophytes
periosteal reaction (new bone formation) |
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What 6 factors do you evaluate to determine aggressive vs. non-aggressive osseous lesions?
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(1) location and # of lesions
(2) pattern of lysis (3) pattern of new bone production (periosteal reaction) (4) cortical disruption (5) transition zone to normal bone (6) change in lesion appearance over time |
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What is osteosclerosis?
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def: increased bone opacity
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What is osteopenia?
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def: generalized decreased bone opacity
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What are the 2 types of osteopenia?
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Osteoporosis
Osteomalacia |
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Compare and contrast osteomalacia
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Osteoporosis
-loss of bone mass (quantity of bone is decreased) -remaining bone is normal Osteomalacia -loss of mineralizaiton of bone matrix (quality of bone is decreased) -increased % fo non-calcified osteoid and/or insufficient mineralization of osteoid matrix -remaining bone is NOT normal |
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What can cause generalized osteosclerosis?
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rare
osteopetrosis myelofibrosis FeLV idopathic dietary imbalances (Ca, Vit D toxicity) |
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What can cause generalized osteopenia?
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congenital Dz (osteogenesis imperfecta)
metabolic Dz nutritional Dz disuse |
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What are the Roentgen signs of generalized osteopenia?
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-decreased bone opacity
-cortical thinning -coarse trabeculation d/t endosteal resorption -relative increase in opacity of cortical bone and vertebral endplates -intracortical bone loss ("double cortical line") -bone deformity or pathologic fractures -loss of lamina dura around teeth (hyperparathyroidism) |
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What is lysis?
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def: focal/multifocal bone loss
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What can cause bone lysis?
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trauma
infection tumor |
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How does the location and number of the osseous lesion(s) influence its aggressiveness?
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primary bone tumors
-appendicular -monostotic -metaphyseal metastatic bone tumors -axial (ribs, vertebra) -polyostotic -diaphyseal or metaphyseal fungal osteomyelitis: -polyostotic -metaphyseal juvenile (hematogenous/bacT) osteomyelitis: -polyostotic -epiphyseal or metaphyseal |
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What do monostotic and polyostotic mean?
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monostotic: involving 1 bone
polyostotic: involving multiple bones |
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What are the 3 patterns of bone lysis (least aggressive to most aggressive)?
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geographic
moth-eaten permeative |
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What are the characteristics of geographic bone lysis?
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large, focal area
+/- expansile well defined, short transition zone least aggressive of bone lysis patterns |
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What can cause geographic bone lysis?
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bone cyst
bone abscess |
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What are the characteristics of moth-eaten bone lysis?
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multiple, small areas
+/- coalescing into larger areas indistinct margins (long transition zone) usually aggressive |
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What can cause moth-eaten bone lysis?
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osteomyelitis
neoplasia |
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What are the characteristics of permeative bone lysis?
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numerous small/pinpoint areas
medulla AND cortex indistinct margins (long transition zone) most aggressive pattern of bone lysis |
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What can cause permeative bone lysis?
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progression from moth-eaten lysis (d/t osteomyelitis or neoplasia)
usually d/t neoplasia |
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If the animal has geographic AND moth-eaten bone lysis, which one do you base your evaluation on?
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the moth-eaten bone lysis
always use the most aggressive feature |
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What is the composition of the periosteum?
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2 layers
-inner: cambium layer (produces bone) -outer: fibrous layer attached to cortex by Sharpey's fibers |
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What factors do you assess to classify periosteal rxns?
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aggressiveness
activity duration |
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How do you assess the aggressiveness of periosteal rxns?
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based on the organization of the new bone
-very organized: non-aggressive -haphazard: aggressive |
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What are the categories of periosteal rxn organization (least aggressive to most aggressive)?
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solid
lamellated columnar (palisading) spiculated (sun burst) amorphous |
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Give an example of each kind of bone organization in periosteal rxns.
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-Solid, smooth bone: callus
-lamellated: low grade osteomyelitis -Columnar (palisading): hypertrophic osteopathy, bacT osteomyelitis -spiculated (sun burst): neoplasia, osteomyelitis -amorphous: neoplasia |
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What are the characteristics of a solid periosteal rxn?
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bone completely fills the area under the rxn
surface is smooth or undulating non-aggressive (usually) callus |
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What are the characteristics of a lamellated periosteal rxn?
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layered "onion skin" appearances d/t cyclic/intermittent bone formation
more aggressive than solid periosteal rxns |
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What are some causes of lamellated periosteal rxns?
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stress fracture
osteomyelitis hypertrophic osteopathy can be a transient feature of normal growth |
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What are the characteristics of columnar to spiculated periosteal rxns?
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columns (palisading) to spiculated (sun burst) projections of bone
bone doesn't completely fill in area under periosteum aggressiveness: solid < lamellated < columnar < spiculated < amorphous |
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What is a cause of columnar periosteal rxns?
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hypertrophic osteopathy
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What is a cause of spiculated periosteal rxns?
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primary bone neoplasia (like osteosarcoma)
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What are the characteristics of amorphous periosteal rxns?
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bone is formed in disorganized manner
+/- destruction of spicules of bone as they're formed most aggressive periosteal rxn |
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What causes most amorphous periosteal rxns?
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neoplasia
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What is Codman's Triangle?
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a solid periosteal rxn seen at the edge of an aggressive rxn
sometimes mistaken for a tumor |
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How do you assess the activity level of a periosteal rxn?
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look at the sharpness of the margins
-sharp margins: inactive -blurry margins: active |
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How do you assess the duration of a periosteal rxn?
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older lesions --> more opaque and "bone-like"
recent lesions --> area under periosteum is soft tissue opaque, turns into bone as it matures remember, these lesions have a 10-14d lag time to be seen in radiographs |
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How does the level of cortical disruption affect the aggressiveness of the bone lesion?
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cortical disruption --> aggressive process
benign processes will allow cortex to remodel or conform to enlarging masses |
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How does the bone lesion's transition zone relate to its aggressiveness?
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long transition zone
-poorly defined demarcation b/w lesion and normal bone -aggressive (osteomyelitis, primary neoplasia, metastatic neoplasia) short transition zone -well-defined demarcation b/w lesion and normal bone -non-aggressive lesions (bone cyst, benign neoplasia) |
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How does the bone lesion's rate of change relate to its aggressiveness?
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aggressive lesions change quickly
-changes seen b/w rads taken 10-14d apart non-aggressive lesions change slowly or appear not to change |
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If your Dx is still unclear after assessing the bone lesion radiographically, what do you do?
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metastasis check
bone biopsy or FNA repeat rads in 10-14d |
