The PA prone radiograph is rarely performed and is often utilized when a patient is unable to lay supine. The projection is adequate for the examination of the abdominal cavity, however, not as practical for the renal structures due to magnification.

the patient is prone, either on the x-ray table (preferred) or on a trolley
patients should be changed into a hospital gown, with radiopaque items (e.g. belts, zippers) removed
the patient should be free from rotation; both shoulders and hips equidistant from the table/trolley
the x-ray is taken in full inspiration

Technical factors

PA projection
centering point
- the midsagittal place (equidistant from each PSIS) at the level of the iliac crest
collimation
- laterally to the lateral abdominal wall
- superior to the diaphragm
- inferior to the inferior pubic rami
orientation
- portrait
detector size
- 35 cm x 43 cm
exposure
- 70-80 kVp
- 30-120 mAs; AEC should be used if available
SID
- 100 cm
grid
- yes

Image technical evaluation

lateral abdominal wall should be included
inferior pubic rami should be included inferiorly
if possible, the diaphragm should be included superiorly
the abdomen should be free from rotation with a symmetry of the:
- ribs (superior)
- iliac crests (middle)
- obturator foramen (inferior)
no blurring of the bowel gas due to respiratory motion

Practical points

For larger patients, it may be necessary to perform two x-rays using a landscape orientation of the detector to include the entire abdomen.

Exposure will need to be adjusted according to an imaging system (CR or DR) and patient size. Where possible mAs should be manipulated to ensure adequate image density and appropriate image contrast.

Ensure the patient has adequate head space to breath and hear instructions.