What is the typical kVp utilized in the "low" phase of energy switching?

• A. 50-70 kVp
• B. 60-80 kVp
• C. 70-140 kVp
• D. 80-100 kVp

Answer: (C)

In bone densitometry, energy switching is a technique that involves alternating between different kilovolt peak (kVp) settings to optimize imaging and assess bone density. The "low" phase typically refers to the kVp range used to penetrate the less dense structures of the body while maintaining good image quality for denser bone material.

The correct range for the "low" phase of energy switching is generally around 70-140 kVp. This kVp range is suitable for reducing the amount of radiation exposure while also allowing enough penetration for effective imaging of the bone. At this higher end of kVp, the X-rays have increased energy which helps in differentiating between bone and soft tissue in the images.

Using a kVp range such as 50-70 would result in insufficient penetration of denser areas, whereas lower settings would compromise the quality of images needed to make accurate assessments in bone densitometry. This higher range allows for a more comprehensive evaluation of bone health and density.