Pediatric lumbar spine (AP/PA view)

The anteroposterior or posterioanterior lumbar spine view for pediatrics is one of two views to examine the lumbar vertebrae. The posteroanterior view is preferred in pediatrics to reduce radiation dose to the child's radiosensitive organs.

Indications

This projection demonstrates the lumbar spine in its natural anatomical position. It is useful in diagnosing fractures in pediatric patients. This view will also demonstrate scoliosis, however in this case specifically, the scoliosis series should be performed.

Patient position

• if performing PA, the patient is erect with the patient's abdomen in contact with the detector

• if performing AP, the patient is erect with the patient's back in contact with the detector

• hands are placed by the patient's side

Technical factors

• anteroposterior or posteroanterior projection

• suspended expiration

• centering point

  • at the level of the iliac crests

• collimation

  • laterally to include the transverse processes and sacroiliac joints

  • superiorly to include the T12/L1 junction

  • inferiorly to include the sacral region

• orientation

  • portrait 

• detector size

  • 24 cm x 30 cm or 35cm x 43 cm depending on the patient's size

• exposure ¹

  • 65-80 kVp

  • 2-12 mAs

• SID

  • 100 cm

• grid

  • no

Image technical evaluation

All lumbar vertebrae should be clearly visible. Sacroiliac joints are seen symmetrical with spinous processes seen centrally to demonstrate no rotation ². A physical metal marker is ideal for pediatric imaging. 

Practical points

Preparing the room beforehand (setting up the detector, exposure and preparing lead gowns) is important as pediatric patients may not remain still.

Immobilization techniques

The radiograph should be free from motion artifact and rotation to avoid repeated x-rays.

• it may be necessary for the parent or radiographer to hold the patient in position

• ideally, the parent should be in the child's direct line of sight; in this case, if the child refuses to stay still in the PA position, an AP position could be performed if this allows the child to directly see the parent

• techniques will vary based on the department

• distraction techniques can be utilized to avoid scattered radiation to parents and staff ³