Figure 3-29. Posteroanterior anal projection of the rectum using the Chassard-Lapine method.
3-13. SPECIFIC BODY FUNCTIONS
a. Relation to Surrounding Space. The manner of placement of the patient in
relation to the surrounding space is one way of defining a body position (for example,
prone and supine positions).
b. Anatomical Surface Nearest the Film. A body position may also be named
according to the anatomical surface (body part) closest to the film. For example, in the
left lateral position, the patient's left side is closest to the film.
c. Author or Originator. As stated in paragraph 3-12, sometimes the body
position that the parent must assume in order to obtain a certain projection is named
after the individual who developed the overall method far placing the patient, film, and
central ray CR, as in the Chassard-Lapine method.
d. Anatomical Structure Demonstrated. In same cases, the position is named
after the anatomical structure demonstrated, as in a PA clavicle.
body position: the way the patient is placed in relation to the surrounding space; the
body described in terms of the part closest to the film, the author of the method, or the
anatomical structure demonstrated.
3-14. LATERAL POSITION
"Latus" is Latin for "side." Thus, a lateral position is one in which the patient is on
his side. If a patient is placed in the lateral position in preparation for a true lateral
projection, the patient is rotated 90 degrees (1/4 turn) from a true AP or PA (figure 3-30).
Thus, a true lateral is perpendicular (at right angles to) a true AP or PA. In the
left lateral position, the patient's left side is against the film. In the right lateral position
the patient's right side is closest to the image receptor.