d. Shielding. Your next step after immobilization is to see to the shielding of the
patient with a lead apron. It is important to protect the patient's body from scatter
radiation. Shielding of the gonadal area (ovaries and testes), when possible, is critical.
If the gonads are not involved, you still need to protect the rest of the body from scatter
radiation, where feasible. For example, when you are radiographing the hand, you
should shield the patient's abdomen and vital organs. There are very few exams for
which you do not shield the patient. For a barium enema (BE), a lead apron over a
female's gonads is not feasible as the shield would obstruct the area of interest. If a
mortally wounded accident victim were brought in for X-rays, there would probably not
be time to shield the patient. If, however, other individuals are present to assist in the
exam, they should be shielded (as in the case of an accident victim who is brought in by
a friend and the friend is asked to hold the patient for radiographing). When
radiographing a cadaver for an autopsy, a shield is, of course, not necessary.
e. The Three-Point Check. The last procedure in patient positioning is the
three-point check, a final verification of the source-to-image receptor distance (SID), the
conefield (CF), if applicable, and the letter (LM).
(1) The source-to-image receptor distance (SID). Make sure that you did, in
fact, select the right SID. Double check the setting: 40 inches or 72 inches as
appropriate to the examination that you are doing.
(2) The conefield (CF). Did you actually cone down to the size film or
conefield being used for the exam?
The letter marker (LM). Did you, in fact, place the correct letter marker
on the film?
THE THREE POINT CHECK
A reverification of the:
3. Letter marker.