What is the typical kVp used in the "high" phase of energy switching?

• A. 60-80 kVp
• B. 80-100 kVp
• C. 100-140 kVp
• D. 140-160 kVp

Answer: (C)

The typical kilovolt peak (kVp) used in the "high" phase of energy switching in bone densitometry is within the range of 100-140 kVp. This range is effective for penetrating the denser structures in the body, such as bone, allowing for improved differentiation between bone and soft tissue in the resultant scans. Utilizing higher kVp values enhances the quality of the images by maximizing the contrast between dense and less dense structures, which is crucial for accurate bone density assessments.

This phase is part of a dual-energy X-ray absorptiometry (DXA) technique where two different energy levels are used to measure bone density. The "high" phase enhances the ability to differentiate bone mineral density from surrounding soft tissues more accurately, thus providing clinicians with reliable data to assess fracture risk and bone health.