[Diagnosis of osteoporosis-importance of dual-energy X-ray absorptiometry].

Dual-energy X‑ray absorptiometry (DXA) assessing the lumbar spine and bilateral proximal femurs is the current guideline-recommended standard method for quantitative measurement of bone density. The output of DXA-the T score-reflects the number of standard deviations by which the measured bone density differs from the average of a healthy young reference population. The operational World Health Organization (WHO) definition of osteoporosis is based on a T score ≤-2.5 at the femoral neck, although other measurement locations are interpreted analogously in clinical routine. Numerous studies have shown that a decrease in bone density is associated with an exponential increase in the fracture risk. However, consideration of the bone density in isolation is inadequate to predict the real fracture risk. Therefore, DXA results must always be interpreted within the context of other clinical risk factors. Additional DXA methods and further analyses can significantly improve the diagnostic accuracy.