Which of the following projections WOULD take advantage of the so-called heel effect if the cathode was toward the head?

The heel effect is a phenomenon encountered in radiography where the intensity of the x-ray beam is greater on the side of the cathode compared to the anode. This effect is significant when positioning patients for certain projections, as it allows for more uniform density in the radiographic image.

In this scenario, when the cathode is positioned toward the head, the denser composition of anatomy such as the femur can benefit from the higher intensity of exposure on that side. The lateral femur projection will require adequate penetration to visualize the entire length of the femur, and having the cathode side toward the head ensures that this critical structure receives sufficient radiation for optimal imaging.

The other projections listed are less favorable for utilizing the heel effect with the cathode toward the head. The AP T/S (Thoracic Spine) and AP L/S (Lumbar Spine) projections generally have uniform anatomy over a wider area, so the heel effect is less beneficial in providing increased density in these cases. Similarly, the lateral L/S projection would not capitalize on the heel effect in the same manner as the lateral femur, as it also involves a broader region needing to be adequately imaged.

Thus, for the lateral femur, positioning the cathode toward the