Arthritis imaging Flashcards
Which study should you order first?
an xray/ plain radiograph ordered first
gives overview and xray corrlated to other non xray studies
Why order a CT scan?
if cortical bone is to be evaluated, for early or subtle change
good anatomy detail
Why order an MRI?
if soft tissue and marrow edema inducing pathology to be studied
highly sensitive
How do you choose MRI or CT?
second study based on pathology
Bone scan?
more multiple sites/screens
metastasis
Arthritis?
disease affecting joint space, bones and soft tissues on both sides of articulation
Classify, 4 types of arthritis?
Degenerative
Inflammatory
Septic/infection/osteomyelitis
Metabolic
Degenerative?
osteophytes, subchondral sclerosis, loss of joint space-usually uneven, cysts (geodes)
Inflammatory?
eroisions, juta-articualr osteoporosis, uniform loss of joint space, usually soft tissue swelling
Septic/infection/osteomyelitis?
rapid onset, usually monarticular, effusion, bone destruction/demineralization
Metabolic?
lumpy/bumpy soft tissue swelling, characteristic marginated bony erosion with overhanging edges
Osteoarthritis?
Disruption/ injury/ degeration of articular cartilage eventually exposing subchondral bone
diarthrodial weight bearing joints, 1 cmc and mtp joints and dip joints of hands, increased incidence with age
any arthritis can develop into this
aggregated by use, relieved by rest, morning stiffness
Osteoarthritis-DJD?
cyst formation, long standing
eburnation?
occurs at areas of cartilage loss
DJD of hand?
CMC joint
nodes
Rheumatoid Arthritis?
Autoimmune/ connective tissue disorder
bilaterally symmetric, soft tissue swelling
2nd and 3rd MCP, 4th and 5th MTP of feet
late- eroisions, marked joints, space narrowing, joint destruction, subchondral cyst, subluxation, fusion, acetabuli protusio (acetabulum into hip)
Eburnation with RA?
no
Other signs of RA?
atlantoaxial subluxation
eroision
osteopenia, joint space narrowing
Septic arthritis?
infection most commonly spread hematogenously from synovium to joint
rapid course, early cortical destruction, pain/swelling, signs of infection (WBS) and monoarticular
high index of suspicion and joint aspiration
Septic arthritis Xray findings?
joint effusion, periarticular osteoporosis, destruction of articular cartilage and cortex on both side of jt rapid onset
Sign of septic arthritis?
severly irregular cortex- white line destruction
Tuberculous arthritis?
insidious course, may take months to have same appearance as pyogenic takes days/weeks
synovitis with pannus leads to chrondronecrosis
phemister triad-gradual, slow joint space narrowing, marginal eroisions, juxtaartricular osteoporosis
condused with atypical monoarticular RA
Sequestration?
space with bone in it
Acute osteomyelitis?
new born formation, abscess, effusion, soft tissue swell, rule out tumor
Diabetic osteomyelitis?
less bony density, osteopenia, irregular
vascular calcification–diabetes
significant soft tissue swell
Three phase bone scan?
hot- tumors, infections, cellulitis with bone
cellulitis- wont see increased activity
Crystal induced arthropathy?
CPPD and Gout
crystal deposition in cartilage and soft tissues, inflammation
CPPF: Chondrocalcinosis with arthritis resembling OA, subchondral cysts
Joints involved Crystal induced arthropathy?
knee, wrist, and hip involvement common
more common in males
Chondrocalcinosis?
seen with gout and crystal deposit
well outlined disc
calcification in joint
Classic gout?
1st MTP classic, erosion with overhanging edge, joint space maintained
Advantages of plain xray?
quick, not expensive, relatively low radiation
Disadvantage of plain xrays?
not 3D, can miss pathology, may still require other imaging studies
CT scanning?
excellant anatomic detail
will detect almost all pathology related to cortical bone injury
great for showing displacement or joint involvement
Advantages of MRI?
no radiation
we can slice through the body using any imaging plane
MRI is very good for looking at the soft tissues
MRI is very sensitive in detecting water
Bone scan?
Tc99m labeled MDP
injected into a vein
tracer accumulates in osteblasts
increased osteoblasts in fracture, tumor and infection
