Page 23 - A Practical Guide to Equine Radiography

4 A PRACTICAL GUIDE TO EQUINE RADIOGRAPHY

• Endosteal new bone: most commonly asso- What can radiographs tell us about soft
VetBooks.ir ciated with trauma, e.g. fractures, but can tissues?

also be caused by infection or inflammation.
• Radiographs are not very sensitive when it
• Cortical thickening: in response to stress.
• Callus formation: fracture repair. comes to the assessment of different soft
tissue densities: e.g. fluids such as blood or
urine have the same radiographic appearance
as most other soft tissues (tendons, cartilage,
How does a decrease in bone etc.).
production appear on radiographs? • The exception is fat, which appears more
Bone resorption results in lysis of bone and radiolucent than other soft tissues, which
appears radiographically as radiolucency. This can, for example, be appreciated in the case
is most commonly focal in the horse but can of the triangular radiolucency consistent
also be diffuse. with the patellar fat pad in the stifle or on
the dorsal aspect of the carpus. The disap-
• Focal lucencies: pearance of these may indicate pathology of
the respective joint.
− Changes in bone contour, e.g. flat- • Abdominal radiography:
tening of trochlear ridges in cases of
osteochondrosis. − The sheer size of an adult horse makes it
− Well-defined lucencies within bone, e.g. impossible to get detailed radiographs of
osseous cyst-like lesions. the adult abdomen. One exception where
− Subchondral bone lucencies, e.g. in abdominal radiographs may be useful is
osteoarthritis. to visualize the presence of sand or entero-
liths in the gut.
• Diffuse lesions: − Abdominal radiographs in foals are
commonly performed to evaluate the gas-
− Diffuse bone resorption affecting whole trointestinal tract and render diagnostic
bones is, for example, seen with disuse results similar to small animals.
osteopenia and results in a honeycomb
appearance of the bone structure. This is • Thoracic radiography:
often most easily appreciated in the proxi-
mal sesamoid bones or the distal phalanx. − This is best performed with a high-
− Diffuse heterogenous lesions are a radio- output X-ray machine and a grid for scatter
graphic sign of neoplastic processes; reduction, hence is usually only done in
however, bone tumours are extremely rare hospital settings.
in horses! − It is not very sensitive for most thoracic
disease and its usefulness should be
considered very carefully in each case,
especially since it involves high radiation
exposures!

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