Bone abnormalities need to be searched for carefully
Chest radiography is not indicated for a suspected simple rib fracture
Malignant bone disease may manifest as either single or multiple lesions
Bones are the densest normal structures seen on a chest X-ray. Despite this, the power of the X-ray beam used is usually not optimised to view the bones, but rather to give greater detail to the lungs and soft tissues. For this reason abnormalities of the bones may not be obvious and so must be searched for carefully.
Bones visible on a chest X-ray include the ribs, clavicles, scapulae, humeri, and the spine. The sternum cannot be seen clearly because it overlies the spine and mediastinum.
Rib fractures
Chest radiography is not indicated for demonstration of a suspected simple rib fracture. This is because many fractures are not visible, and because management is not altered even if it is seen. If there is clinical suspicion of complications such as a pneumothorax, a chest X-ray is indicated.
There is angulation of the ribs at multiple fracture sites (arrows)
At the site of injuries there is increased density (whiter areas) due to callus formation
Malignant bone disease
There may be evidence of metastatic bone disease on a chest X-ray. This may manifest as a single bone metastasis, or as a diffuse abnormality representing widespread metastases. Bones may become denser (whiter) due to a sclerotic process (often seen in prostate cancer), or less dense (blacker) due to a lytic process (as is often the case in renal cell cancer).
Bone metastases may present with pathological fractures which may appear as acute or old fractures, depending on the stage of healing.
Primary bone tumours, both benign and malignant, are relatively uncommon.
