Evaluating Diagnostic Images

errors of observation

missing an abnormality

errors of interpretation

failure to link abnormal finding to relevant clinical data

ABCS search pattern

A = alignment

B = bone density

C = cartilage spaces

S = soft tissues

how does decalcification appear on an xray

fluffy appearance

things to evaluate with alignment

general skeletal architecture, general contour of bones, alignment of bones

things to evaluate with bone density

general bone density, textural abnormalities, local bone density changes

things to evaluate with cartilage spaces

joint space, subchondral bone, epiphyseal plate

SALTER

looking at epiphyseal plate fx

S = straight across

A = above

L = lower or below

T = two or through

ER = erasure of growth plate or crush

ME

M = metaphysis

E = epiphysis

• grade I: fx through physis

• grade II: tx through physis and Metaphysis

• grade IIIL fx through physis and Epiphysis

• grade IV: through physis, Metaphysis, and Epiphysis

• grade V: crush/compression to physis

what to evaluate for soft tissues

muscles, fat, joint capsules, periosteum, miscellaneous soft tissue findings

fat pad sign

= sail sign = trauma or inflammation of a joint

FBI sign

= fat blood interface = fluid in joint, could be due to a fx

periosteal reactions

1. solid = benign

2. lamellated = slightly aggressive

3. spiculated = aggressive

4. codman’s = very aggressive

OA

degenerative condition in which cartilage wears down, most common type of arthritis

RA

progressive, systemic, autoimmune disease where the immune system attacks the body’s own tissue causing inflammation affecting primarily the synovial joints

osteoporosis

cortical thinning, low bone mass, trabecular changes, fx

imaging of osteoporosis

1. Dual-Energy X-ray Absorptiometry (DXA) → T-score and Z-score

2. peripheral screening → peripheral DXA (pDXA), quantitative ultrasound (QUS), peripheral quantitative computed tomography (pQCT)

T-score

compares your results to a healthy young adult age 20-35 → 0 means you’re the norm

Z-score

compares your results to a person of the same gener and age as yourself → 0 means you’re the norm

T-score and z-score -1.5 to -2.4

may indicate osteopenia (precursor to osteoporosis)

T-score and Z-score less than -2.5

may indicate osteoporosis

osteomyelitis

bone infection

septic arthritis

joint infection

cellulitis/myositis

infection of soft tissue