Musculoskeletal Flashcards
How frequently are OCD lesions in the caudal aspect of the humeral head bilateral?
85%
Diagnostic sensitivity of RG,US & MRI for OCD. VRU 56.1
Based on the article: Diagnostic sensitivity of RG, US and MRI for shoulder OCD, what views should be performed to evaluate for OCD?
Lateromedial, supinated and pronated lateromedial views
Craniocaudal views to rule out any additional pathology or fragments
Diagnostic sensitivity of RG,US & MRI for OCD. VRU 56.1
What was sensitivity/specificity for radiographs/US/MRI for detecting OC/OCD lesions or flaps?
Diagnostic sensitivity of RG,US & MRI for OCD. VRU 56.1
OC/OCD lesions:
Radiographs: 88.5/90
US: 92/60
MRI: 96/89
Flaps:
Rad: 22/100
US: 11/87
MR: 75/93
What is the best sequence to visualize Shoulder OCD using MRI?
Diagnostic sensitivity of RG,US & MRI for OCD. VRU 56.1
Sagittal Fat sat - either T2 or PD
Diagnostic sensitivity of RG,US & MRI for OCD. VRU 56.1
In regards to shoulder OC/OCD: positive likelihood ratios were high for MR and radiography for??
Diagnostic sensitivity of RG,US & MRI for OCD. VRU 56.1
detecting presence of OC/OCD, presence of flaps, and sclerosis (rad) or bone marrow lesions (MRI)
MRI had higher odds ratios for detecting OCD lesions, for boths rads and US. What else did MR have a higher odds ratio for?
Diagnostic sensitivity of RG,US & MRI for OCD. VRU 56.1
detecting in situ flap, and the presence of subchondral bone marrow lesions (vs sclerosis on rads).
What are the radiographic changes seen in primary and concomitant flexor enthesopathy?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
Irregular margination of the medial humeral epicondyle Adjacent calcified bodies Spur on the medial epicondyle Subtrochlear sclerosis Ill-defined medial coronoid process \+/- other OA changes
What is the difference between primary and concomitant flexor enthesopathy?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
Primary - only changes associated with the ligaments and enthesis of the flexor tendons
Concomitant - frequently seen in association with medial coronoid disease, or other forms of elbow dysplasia.
Both forms may or may have OA changes.
Can radiography be used to delineate between primary and concomitant flexor enthesopathy?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
No - may need to perform other imaging modalities
What are US findings consistent with a flexor enthesopathy in the elbow?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
Abnormal fiber structure within the flexor tendons
Abnormal attachment, outward bowing of flexor muscles
Irregular margination of humeral medial epicondyle
Focal acoustic shadowing within flexor muscles - calcification
What are scintigraphic findings consistent with a flexor enthesopathy in the elbow?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
increased RPUin area of medial humeral epicondyle
What are CT findings consistent with a flexor enthesopathy in the elbow?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
CT of canine elbow joints affected by primary and concomitant flexor enthesopathy VRU 55.1
Irregular, sclerotic, thickened medial humeral epicondyle
thickened flexor muscles with contrast enhancement
focal area of increased attenuation in muscles (calcified bodies)
What are MRI findings consistent with a flexor enthesopathy in the elbow?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
irregular, sclerotic medial humeral epicondyle
thickened muscles with contrast enhancement
focal area of low signal intensity within muscle - calcified body
What are the approximate % of radiographic changes for primary and concomitant groups in the following categories:
1) Irregular margination of medial humeral epicondyle
2) Spur formation
3) Calcified body
4) Subtrochlear sclerosis
* *For each of these groups - what form of OA was most commonly associated with each type?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
1) Irregular margination - Pri - 34%, Con - 33%
Con - severe OA in 2/3
2) Spur formation - Pri - 66%, Con - 67%
Pri - can be in absence of OA
Con - Mod OA
3) Calcified body - Pri - 41%, Con - 33%
Pri - Mod OA
Con - Severe OA
4) Subtrochlear sclerosis - Pri - 62%, Con - 70%
In absence of any OA changes in the elbow - what radiogrpahic findings should make you think of flexor enthesopathy?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
Irregularity of the medial epicondyle
Spur formation
What was most common CT finding consistent with flexor enthesopathy? Give approximate percentages for each group (primary and concomitant)
CT of canine elbow joints affected by primary and concomitant flexor enthesopathy VRU 55.1
Flexor muscle thickening and enhancement
Primary - 93%
Concomitant - 81%
Of the CT findings, which were most inconsistently found in both groups?
CT of canine elbow joints affected by primary and concomitant flexor enthesopathy VRU 55.1
Calcified body
Historically, what is most common finding associated with flexor enthesopathy on radiographs?
What was most common in this article?
Radiographic features of primary and concomitant flexor enthesopathy in the canine elbow. VRU 54.2
Calcified body
Spur formation
What were most common MR findings consistent with flexor enthesopathy:
MRI of primary and concomitant flexor enthesopathy in the canine elbow. VRU 55.1
Irregular outline of the medial epicondl eThickened cortex Flexor thickened Hyperintense flexors contrast enhancement of hte flexors calcified bodies
Which MR findings consistent with flexor enthesopathy were most common for each group? Give approximate percent.
Which sequences were best to see these changes?
MRI of primary and concomitant flexor enthesopathy in the canine elbow. VRU 55.1
Thickened and/or hyperintense flexors.
Primary - 100%/100%
Concomitant: 96/89
T2 and STIR
What was least common finding on MR for flexor enthesopathy?
MRI of primary and concomitant flexor enthesopathy in the canine elbow. VRU 55.1
Calcified body and medial coronoid abnormalities (18% in concomitant group)
MRI is one of the worst modalities for helping determining between primary and concomitant flexor enthesopathy. why?
MRI of primary and concomitant flexor enthesopathy in the canine elbow. VRU 55.1
MR was pretty terrible at identifying bony pathology (medial coronoid problems)
What were common findings for scintigraphy in flexor enteshopathy?
Use of SPECT for diagnosis of primary and concomitant flexor enthesopathy in the canine elbow. Vet Comp Trau and Ortho 5/2013
Increased uptake in the medial humeral epicondyle
Increased uptake in the medial coronoid
SPECT had fairly good sensitivity and positive predictive value. What brought down the specificity and NPV?
Use of SPECT for diagnosis of primary and concomitant flexor enthesopathy in the canine elbow. Vet Comp Trau and Ortho 5/2013
Increase uptake in the medial coronoid process in dogs with primary enthesopathy.
What are typical MR findings for bone infarction?
Imaging diagnosis - medullary tibial infarction in a horse. VRU 51.2
Double line sign in all sequences
T1: Central hyperintense, surrounded by hypointense zone
T2: Central hypointense, hyperintense rim, intermediate halo on the outside
STIR: hypointense center, hyperintense halo, hypointense marrow
What are causes of bone infarction?
Imaging diagnosis - medullary tibial infarction in a horse. VRU 51.2
thromboembolic cardiac disease, tumors, traumatic injuries, idiopathic (most common)
Why does the double line sign occur on MRI in bone infarction?
Imaging diagnosis - medullary tibial infarction in a horse. VRU 51.2
Differentiation between viable and non-viable tissues
T2:
Hyperintense rim: granulation tissue
Hypointense halo: sclerotic bone
Lesions occuring in the distal phalanges that may be aggressive or just exhibit a smooth periosteal reaction.
Epidermoid intraosseous cysts can be lytic or proliferative. Histopath is the only way to know for sure. VRU 33.3
What is the difference between an AVM or AVF?
Imaging diagnosis - Radiographic, US, CT and fluoroscopic appearance of a distal pelvic limb AV malformation in a young GS dog. VRU 57.2
AVF - single connection between an artery and vein, usually acquired
AVM - complex lesion that involve multiple aberrant shutning vesels that originate from one or more arteries and terminate in one or more venous structures. Most commonly are acquired
How do Arteriovenous fistulas form?
Imaging diagnosis - Radiographic, US, CT and fluoroscopic appearance of a distal pelvic limb AV malformation in a young GS dog. VRU 57.2
blunt or penetrating trauma, surgical procedures or catheterization
What is fremitus or bruit?
Imaging diagnosis - Radiographic, US, CT and fluoroscopic appearance of a distal pelvic limb AV malformation in a young GS dog. VRU 57.2
Fremitus - vibratory tremors felt through the chest by palpation
Bruit - murmur heard in the artery - high rate of blood flow through an unobstructed artery
What are some radiographic changes associated with lymphoma?
Radiographic diagnosis - polyostotic lymphoma in a 5m old dog VRU 42.6
sternal, cranial mediastinal, trachealbronchial and abdominal lymphadenopathy, diffuse unstructured interstitial pulmonary infiltrates, solitary pulmonary masses, hepatic or splenic enlargement, pleural or peritoneal effusion and osteolytic changes
Why is their hypercalcemia in animals with lymphoma?
Radiographic diagnosis - polyostotic lymphoma in a 5m old dog VRU 42.6
PTH related protein (PTHrp) is secreted which is very similar to the hormone secreted by the parathyroid glands (PTH)
Elevated PTHrp results in increased bone resorption (via osteoclasts), increased serum calcium resorption, increased intestinal absorption of calcium, and increased production of Vitamin D in the kidneys.
What are other causes of bone destruction in lymphoma (other than alterations in PTH)?
Radiographic diagnosis - polyostotic lymphoma in a 5m old dog VRU 42.6
Direct neoplastic infiltration of bone marrow resulting in infarction and necoriss with secondary absorption via osteoclasts
What are other differentials for ostoepenia/lytic bone lesions?
Radiographic diagnosis - polyostotic lymphoma in a 5m old dog VRU 42.6
primary or secondary hyperparathyroidism, multiple myeloma, other primary neoplasia, bone mets, multifocal fungal osteomyelitis
What breeds are predisposed to histiocytic sarcoma in the bone?
Skeletal lesions of histiocytic sarcoma in 19 dogs. VRU 48.6
Rottweilers, Golden retrievers
What is the difference between localized and disseminated HS?
Skeletal lesions of histiocytic sarcoma in 19 dogs. VRU 48.6
Localized - better prognosis. can eventually metastasize
Disseminaetd - affects multiple organ systems, grave prognosis
What were common sites of osseous involvement?
Skeletal lesions of histiocytic sarcoma in 19 dogs. VRU 48.6
Periarticular bones
Proximal humerus
Rib
Vertebrae
What radiographic changes are seen in histiocytic sarcoma of the bone?
Skeletal lesions of histiocytic sarcoma in 19 dogs. VRU 48.6
All types of lysis - osteolytic
Variable new bone formation
What are other differentials for periarticular tumor resulting in multiple bone lysis?
Skeletal lesions of histiocytic sarcoma in 19 dogs. VRU 48.6
Bacterial osteomyelitis
Synovial cell sarcoma
Which is more common - synovial cell sarcoma or periarticular histiocytic sarcoma?
Skeletal lesions of histiocytic sarcoma in 19 dogs. VRU 48.6
Histiocytic sarcoma is 3x more likely
What are differential diagnoses for bony lytic lesion?
Osteomyelitis associated with disseminated blastomycosis in 9 dogs VRU 1979
primary and metastatic neoplasia
fungal: crypto, histo, blasto
Bacterial osteomyelitis
What are imaging characteristics for blasto bone lesions?
Osteomyelitis associated with disseminated blastomycosis in 9 dogs VRU 1979
Lytic lesion with periosteal reaction, thickened soft tissue
What were common locations for blasto bone lesions?
Osteomyelitis associated with disseminated blastomycosis in 9 dogs VRU 1979
appendicular skeleton - distal to radiocarpal, tibiotarsal
Lots of metacarpal/tarsal and carpal/tarsal bones
Femur, radius, ulna, tibia all were seen with lesions
only 2 lesions were above the elbow
What are 2 mechanisms of tumor spread of melanoma/
Malignant melanoma with skeletal metastasis in a dog VRU 1976
blood
lymphatics
Where were radiographic changes of bone metastasis
Malignant melanoma with skeletal metastasis in a dog VRU 1976
Medullary origin
polyostotic
cortical destruction
lytic
What are common sites of metastasis?
Malignant melanoma with skeletal metastasis in a dog VRU 1976
region node and lungs
Others: spleen, kidney, liver, cns, adrenal, heart, pituitary, bone
What is the difference between osteosarcoma and parosteal osteosarcoma?
Parosteal osteosarcoma of hte cervical vertebra in a dog VRU 38.2
Osteosarcoma - originates from the medulla
Parosteal - arises from the surface of the bone/periosteal connective tissue
What are the imaging characteristics seen with parosteal osteosarcoma?
Parosteal osteosarcoma of hte cervical vertebra in a dog VRU 38.2
Parosteal - cortex is intact, smooth borders, may not have any lysis
What characteristics make osteosarcomas less malignant in cats than dogs?
primary bone tumors in the cat. VRU 1982
Metastasis is not common (
Most common bone tumor in cats and their location?
primary bone tumors in the cat. VRU 1982
Osteosarcoma
Similar sites in the appendicular skeleton to dogs
What is the top 3 most common bone tumors in cats?
primary bone tumors in the cat. VRU 1982
Osteosarcoma
Fibrosarcoma
Chondrosarcoma
Which aggressive bone characteristic is not seen with osteosarcoma in cats?
primary bone tumors in the cat. VRU 1982
Periosteal proliferation - usually much slower growing
What are imaging characteristics of chondrosarcoma?
primary bone tumors in the cat. VRU 1982
Osteoblastic, minimal cortical or periosteal response
Very organized
Imaging characteristics of parosteal osteosarcoma?
primary bone tumors in the cat. VRU 1982
Slow growing sarcoma arising from the bone forming periosteal connective tissue
Imaging characteristics of giant cell tumors?
primary bone tumors in the cat. VRU 1982
Intramedullary origin, marked lysis with cortical destruction and pathologic fractures
Indistinct tumor margins
Imaging characteristics of osteosarcoma?
primary bone tumors in the cat. VRU 1982
Indistinct margins
Cortical destruction
Large extraosseous mineralized component (not periosteal reaction)
What is different between multiple cartilaginous exostoses in cats and dogs?
primary bone tumors in the cat. VRU 1982
Dogs - appear before skeletal maturity, and stop once maturity has been reached
Cats - do not appear until after skeletal maturit and thus continue to grow until there is functional impairment. and may be associated with FeLV
