How should the proximal femur be positioned for a scan?

• A. Externally rotated and free from obstruction
• B. Internally rotated and secured in the foot positioning device
• C. Flexed at the knee for comfort
• D. Extended with a cushion for support

Answer: (B)

The proximal femur should be positioned with internal rotation and secured in the foot positioning device to ensure accurate imaging during a bone densitometry scan. Internal rotation helps to align the femoral neck along the correct axis, which is critical for obtaining precise measurements of bone mineral density. Proper alignment minimizes the effects of positioning on the results, allowing for standardized evaluations.

Using a foot positioning device further stabilizes the patient's leg and maintains this internal rotation, reducing the likelihood of any motion artifacts that could compromise the scan quality. This setup is essential for achieving consistent, reliable results that can be compared over time and across different patients.

The other positioning options do not meet the necessary criteria for accurate imaging. External rotation, while perhaps comfortable for some patients, would not align the femoral neck properly for the required measurements. Flexing at the knee could alter the positioning of the proximal femur, affecting the orientation and potentially the accuracy of the scan. Extending the leg with a cushion may provide comfort but does not ensure the femur is positioned correctly for optimal imaging.