[Conventional radiology of osteoporosis and radiographic absorptiometry]

Radiographic findings suggestive of osteopenia and osteoporosis are frequently encountered in daily medical practice and can result from a wide spectrum of diseases ranging from highly prevalent causes such as postmenopausal and involutional osteoporosis to very rare endocrinologic and hereditary or acquired disorders. As bone mass is lost, changes in the trabecular and cortical bone structure occur. The changes that are visible on conventional radiographs may give specific information on the etiology of the underlying disease. Even though conventional radiography is indispensable in the differential diagnosis of osteopenia and osteoporosis, visual assessment of bone mass and its changes is subjective and strongly depends on the radiographic technique. With radiogrammetry and radiographic absorptiometry two methods exist that rely on conventional radiography and allow for a quantification of bone mass.