Dual energy X-ray absorptimetry: fundamentals, methodology, and clinical applications.

Dual-energy X-ray absorptiometry (DXA; DEXA) is the technique of choice to diagnose osteoporosis and to monitor the response to treatment. It is also useful for measuring body composition. In recent years, new applications have been developed, including vertebral morphometry through the study of the lateral spine, prosthesis integration in orthopedics, and lipodystrophy in HIV+ patients, although its use in these cases is not well established. DXA densitometry is accurate and precise. It is essential to optimize each step of the diagnostic process, taking care to ensure the best acquisition, image analysis, and interpretation of the results. Thus, to obtain the greatest utility from DXA, radiologists need to know the technique, its indications, and its pitfalls. This article reviews the fundamentals, modalities, methods, and clinical applications of DXA.