anteroposterior projection: a projection of the X-my beam human anterior
surface to a posterior surface.
Figure 3-24. Anteroposterior chest projection with central ray entering anterior surface
and traveling to posterior surface
The view is the opposite of the projection and can be described as the way the
image is seen from the vantage point of the image receptor. It is what is seen when the
radiograph is viewed from the viewbox (figure 3-25). The term PA protection describes
how the CR travels from the X-ray tube through the posterior aspect to the anterior
aspect to the film. The term AP view describes how the side closest to the film, that is,
the posterior surface, is demonstrated (figure 3-26).
Figure 3-25. The radiologist, looking over X-rays at a viewbox.