What adjustments may need to be made for individuals with obesity during a DXA scan?

• A. Change the patient position
• B. Increase radiation exposure
• C. Machine calibration due to fat distribution and attenuation
• D. No adjustments are necessary

Answer: (C)

In a DXA (Dual-Energy X-ray Absorptiometry) scan for individuals with obesity, it is important to consider how fat distribution and attenuation can affect the accuracy of the bone density measurements. The correct answer emphasizes the necessity of machine calibration to accommodate these factors.

Individuals with obesity often have a different body composition and fat distribution compared to individuals with an average body weight. Increased fat can attenuate X-rays more than lean mass due to the differences in density. This means that the machine needs to account for this when calculating bone mineral density (BMD) to provide accurate results. Calibration adjustments tailored to individual body composition ensure that the scan interprets the data correctly, reflecting a more accurate assessment of bone health.

This calibration process may involve modifying parameters of the scan protocol to account for the additional soft tissue, ensuring that the readings for bone density are not erroneously elevated or depressed due to the presence of excess adipose tissue. Therefore, machine calibration is critical in enhancing the precision of the DXA results for obese patients.