Clinical Osteology · Oct 8, 2026
Computed tomography and opportunistic osteoporosis screening
By Girsa D, Malíková H
Osteoporosis represents a serious health problem with a high risk of fractures, morbidity, and mortality. Although population-based screening using clinical examination, the “Fracture Risk Assessment Tool” questionnaire, and bone densitometry (DXA) was introduced in the Czech Republic in 2023, some patients remain undetected. One option for improving early diagnosis is opportunistic screening, that is, using CT examinations already performed for another indication. CT examinations contain information about bone density that can be obtained by measuring the CT attenuation of trabecular bone, most commonly in the L1 vertebral body, expressed in Hounsfield units (HU). Low CT attenuation values indicate reduced bone mineral density and may serve as a basis for recommending a subsequent DXA examination. In addition to CT attenuation measurements, the presence of vertebral compression fractures is also an important finding; these often remain overlooked despite being associated with a significantly increased risk of a future severe femoral fracture. The advantages of opportunistic screening are the use of existing data without additional radiation exposure, an increase in the number of patients detected, and potential cost savings. The disadvantages are difficulties in standardizing assessment, greater workload, and the fact that it reaches only individuals already undergoing examinations within the healthcare system. Bone CT attenuation values are affected primarily by the X-ray tube voltage during the CT examination, calibration of the CT scanner, and the use of intravenous contrast agents. The results must therefore be interpreted with regard to the technical parameters of the examination. The use of specialized software and artificial intelligence represents a promising prospect. Opportunistic osteoporosis screening has the potential to improve early diagnosis. Its wider implementation requires standardization of the methodology and collaboration among medical managers, clinicians, radiologists, and radiation physicists, as well as the use of modern information technologies.