Final answer:
A patient must stand facing the x-ray tube with the anterior surface of the shoulder against the image receptor for a PA clavicle projection. The shoulders should be rolled forward to decrease overlap with the scapulae, and a 45-degree cephalic tilt may be utilized for a better view.
Step-by-step explanation:
The patient position for a PA clavicle projection typically requires the patient to stand facing the x-ray tube, with the anterior surface of the shoulder against the image receptor. The patient's feet should be shoulder-width apart for stability, and arms hanging naturally at the sides. The patient is instructed to roll the shoulders forward to bring the scapulae out of the way, and to depress the shoulders and extend the neck if possible. This position allows for the best visualization of the clavicle without as much overlapping of bony structures.
For a better assessment of the clavicle, a 45-degree cephalic tilt may also be used, but it's not as common as the standard PA projection for this purpose.