Which of the following regions is NOT included in the proximal femur ROIs?

The proximal femur regions of interest (ROIs) typically include anatomical areas that are critical for assessing bone density and evaluating the risk for fractures, particularly in osteoporotic patients. The proximal femur ROI encompasses regions like the trochanteric region, which is important for understanding the mechanical properties of the femur and its susceptibility to fractures. Ward's region, a specific zone within the femoral neck, is also included as it plays a significant role in hip fracture risk assessment.

The distal femur shaft, however, is not considered part of the proximal femur regions. It is located much further down the femur, away from the hip joint, and does not share the same biomechanical properties and fracture risk characteristics associated with the proximal femur. Similarly, while the term "shaft" could generally refer to the entire length of the femur, it is typically associated with the diaphyseal region and, in terms of bone density analysis, is distinct from the proximal femur.

Thus, the correct response is that the distal femur shaft is not included in the proximal femur ROIs, as it is anatomically and functionally separate from the regions that are primarily evaluated for hip fracture risk.