How many degrees should you rotate the femur when positioning for a proximal femur scan?

• A. 5-10 degrees
• B. 15-25 degrees
• C. 30-35 degrees
• D. 45-50 degrees

Answer: (B)

When positioning for a proximal femur scan, rotating the femur 15-25 degrees internally helps ensure proper alignment of the hip joint in relation to the imaging detector. This internal rotation is essential for accurately capturing the region of interest, which includes the femoral neck and head.

This rotation aligns the femoral neck parallel to the detector, allowing for a true representation of bone mineral density in that area, which is crucial for assessing potential osteoporosis or other skeletal conditions. Properly executing this positioning technique contributes to obtaining optimal imaging results and enhances diagnostic accuracy.

Degrees of rotation that are too low may not adequately position the femur, potentially leading to foreshortened images or misrepresentation of bone density. Conversely, excessive rotation may result in distortion of the proximal femur, which could compromise the quality of the scan and interfere with identifying areas of concern. Therefore, adhering to the recommended range of 15-25 degrees is critical for effective imaging in bone densitometry.