What technology is primarily used in dual-energy X-ray absorptiometry (DXA)?

• A. Magnetic Resonance Imaging
• B. X-rays
• C. Ultrasound
• D. Computed Tomography

Answer: (B)

Dual-energy X-ray absorptiometry (DXA) primarily utilizes X-ray technology to measure bone mineral density. This method involves the use of two different energy levels of X-rays, which allows for the precise differentiation between bone and soft tissue. By measuring the absorption of these X-ray energies as they pass through the body, DXA can effectively assess bone density, which is critical for diagnosing conditions like osteoporosis and evaluating fracture risk.

The choice of X-rays in DXA is essential because this technique provides high precision and accuracy in measurements, which is vital for clinical assessments. Other imaging modalities, such as Magnetic Resonance Imaging, Ultrasound, and Computed Tomography, are not used in DXA, as they have different mechanisms and applications that do not align with the specific requirements for measuring bone density.