Figure 3-30. A true lateral is rotated 90 degree or 1/4 turn from a PA or AP projection.
3-15. OBLIQUE POSITION
In the oblique position, the frontal or coronal body plane (the plane that divides
the body into anterior and posterior portions) is neither at right angles (lateral) nor
parallel (PA or AP) to the film, such as demonstrated in figure 3-31. This plane is
somewhere between a PA (or AP) and a lateral. The exact amount of body rotation in
an oblique position will change according to the anatomical structure to be
demonstrated. But, it will be somewhere between a PA (or AP) and lateral.
Figure 3-31. In the oblique position the frontal or coronal plane is somewhere between
a PA (or AP) and a lateral.
3-16. DECUBITUS POSITION
The term "decubitus" is derived from the Latin verb "decumbere," which means to
lie down. Decubitus terminology indicates the position of the patient during the
examination. Decubitus is a general term meaning the act of lying down and the
position that the patient assumes in lying down. There are a number of decubitus (lying
down) positions. These are defined according to the way in which the body part/surface
comes in contact with the bed or other surface. Before specifying the various decubitus
positions the related term "recumbent" needs to be defined (paragraph 3-17).
decubitus position: the patient in a lying down position.