c. Oblique Projections.
(1) Positioning the patient. To obtain an oblique projection, the patient must
be positioned in an oblique body position. As you recall, in an oblique position the body
part is rotated so that neither a frontal (AP or PA) nor a lateral projection is produced.
(2) Use of oblique projections. As stated earlier, oblique projections
supplement AP and lateral views.
(right or left) and the body surface (anterior or posterior) closest to the film. There are
three alternative names for the position shown in figure 3-41. The patient's right side is
closest to the film and that the central ray is traveling from a posterior to anterior
surface. Thus, this can be termed a left posterior to right anterior projection with the
patient in the oblique body position. It can also be termed a right posteoanterior (PA)
oblique projection. But most commonly, it is referred to as a right anterior oblique
(RAO) projection. Right anterior oblique is the term used by most radiographers in the
United States (US). It is still useful, however, to also be familiar with the other alternative
names for each oblique projection. (In this text, the term RAO will be used.) In figure 3-42,
the patient is in an oblique position with the left side closest to the film. The central ray is
following a posterior to anterior direct this projection can be described using any of the three
names listed in the caption. Again, most radiographers will call this a left anterior oblique (LAO)
position. The remaining oblique projections are shown in figures 3-43 and 3-44.
Figure 3-41. Right anterior oblique (RAO), left posterior to right anterior projection in the
oblique body position, or right posteroanterior (PA) oblique projection.
Figure 3-42. Left anterior oblique (LAO), or right posterior to left anterior projection with
the patient in the oblique position, or left posteroanterior (PA) oblique projection.