Interpreting X-rays

Wikis > Imaging > X-ray > Interpreting X-rays

Observer variation in interpretation is common.

Density - the amount of blackening/darkness in the x-ray
Increased density – denotes a whiter or lighter shadow on the x-ray
Increased radiolucency – a greater penetration by the x-rays
Increased radiopacity – diminished penetration by the x-rays
Contrast – the difference in the degree of density distinction between black and white images
Sclerosis – an increase in the density of bone such as that its radiographic appearance is whiter than usual
Eburnation – (same as sclerosis) – but is the final stage of sclerosis

Radiolucency – the ability of x-rays to penetrate a given material
Radiopacity – the difficulty in ability to penetrate a given material

The ABC’s or ABCD’s approach:
D = distal to proximal
S = Soft tissue
C = Cartilage space
B = Bony mineralisation
A = Alignment

Soft tissues – do the soft tissue follow the bone’s contour; are there any areas of increased density; are the fascial planes distinguishable; soft tissue calcifications; fad pad displacement; joint effusions
Cartilage – changes in joint space; changes in subchondral bone; any sclerosis.
Bone – all present?, density changes, erosions, loss of bone, fractures
Alignment – consistency of foot alignment with clinical examination; trabecular pattern; presence of fracture

The interpretation of foot x-rays can be confusing due to a large number of normal variants, accessory bones and overlapping of osseous segments.

Interpretation of a foot X-ray:
1) Identify the view
2) Overall condition of bone
3) Cortical and trabecular patterns
4) Soft tissues
5) Phalanges (all present; note fusions, joint space narrowing, erosions, rotations, fractures, exostoses, state of distal tufts, tumours)
6) Metatarsals (all present; note fractures, previous surgery, erosions, cystic degeneration, exostoses, shape of metatarsal heads, shape and alignment of shafts, deformities, tumours, periosteal reactions; note joint structure and alignment)
7) Tarsals (all present; note joint spacing, fractures, dislocation, erosions, tumours, accessory bones)
8) Lateral view (note talar dome shape, calcaneal spurring, cyma line, calcaneal inclination angle, metatarsal declination angle, talar beaking, first metatarsal phalangeal joint structure/shape, exostoses, fractures, calcifications, tumours)
9) Anteroposterior view (note alignments, cyma line, relationships between bones)
10) Relate this to available clinical and other laboratory data

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