An AP pelvis X‑ray is an anteroposterior radiograph of the pelvis taken with the X‑ray beam passing front‑to‑back while the patient lies flat or stands. It shows pelvic bones, hip joints, sacrum and proximal femora to detect fractures, dislocations, arthritis, degenerative changes or congenital abnormalities. It’s quick, noninvasive; metal is removed and pregnancy should be reported.

AP view means anteroposterior projection: the X‑ray beam passes from the front (anterior) of the body to the back (posterior) onto a detector behind the patient. It’s used when patients cannot stand for a PA view (for example, supine or bedridden). AP films can magnify the heart and alter mediastinal appearance, so interpretation adjusts for projectional differences.

A standard pelvis X‑ray is an anteroposterior (AP) view taken with the patient supine or standing and both legs slightly internally rotated to align the femoral necks. It displays the pelvic ring, hips and proximal femora. Additional projections — inlet, outlet, Judet obliques or dedicated hip lateral/frog‑leg — are used for suspected acetabular or femoral‑neck injury.

For an AP pelvis radiograph, center the x‑ray beam at the midpoint between the anterior superior iliac spines (ASIS) and the pubic symphysis—approximately at the level of the femoral heads. Have the patient supine with both legs internally rotated about 15° to place the femoral necks parallel, and collimate to include the iliac crests down to the proximal femora.

AP pelvis is a single anteroposterior radiographic view of the whole pelvis, obtained with the patient supine and legs internally rotated. It serves as the primary pelvic film; additional views (inlet/outlet, Judet obliques) or dedicated hip projections may be requested for trauma, suspected fractures, or further assessment, and CT/MRI are used when more detailed imaging is needed.

AP (anteroposterior) and PA (posteroanterior) describe X-ray beam direction. In AP the beam travels front-to-back, used for supine or portable films; it increases heart and mediastinal magnification. In PA the beam travels back-to-front with the patient standing against the detector; it reduces magnification and gives a more accurate heart size and better lung detail, so PA is preferred for routine chest X-rays.