For a unilateral AP hip projection, where should the central ray enter?

For a unilateral AP hip projection, where should the central ray enter?

• A. Hip joint
• B. Acetabulum
• C. Femoral neck
• D. Mid-shaft of femur

Answer: (C)

Center the beam at the midpoint of the femoral neck. Directing the central ray here ensures the proximal femur, especially the neck, is well visualized with the neck in profile and minimized distortion when the leg is properly rotated. This position provides a true AP view of the hip, showing the femoral head, neck, and acetabulum in a single image. If you aimed at the hip joint, acetabulum, or mid-shaft instead, you’d risk worse neck foreshortening or missing the critical proximal anatomy that defines the hip projection.

Center the beam at the midpoint of the femoral neck. Directing the central ray here ensures the proximal femur, especially the neck, is well visualized with the neck in profile and minimized distortion when the leg is properly rotated. This position provides a true AP view of the hip, showing the femoral head, neck, and acetabulum in a single image. If you aimed at the hip joint, acetabulum, or mid-shaft instead, you’d risk worse neck foreshortening or missing the critical proximal anatomy that defines the hip projection.