Where is the central ray directed in an anteroposterior (AP) axial inlet projection of the pelvis?

In an anteroposterior (AP) axial inlet projection of the pelvis, the central ray is directed specifically at the pubic symphysis. This positioning is crucial because the pubic symphysis serves as a landmark to ensure the correct anatomical view of the pelvis is obtained. The inlet view is oriented to display the pelvic inlet—a vital area in assessing pelvic conditions, injuries, or anatomical variations. Aligning the central ray with the pubic symphysis provides an ideal perspective for evaluating the pelvic inlet.

In comparison, focusing the central ray at the sacral curve, greater sciatic notch, or the level of L4-L5 would not effectively capture the necessary anatomy of the pelvic inlet, thereby compromising the diagnostic quality of the image.