Pediatric abdomen (AP supine view)

The AP supine abdominal radiograph is a routine view when imaging the paediatric abdomen. This view may be taken alongside the PA erect and lateral decubitus views. As radiation protection is an essential consideration in paediatrics, some departmental protocols may only perform one view (either the AP supine or PA erect view) depending on the clinical indications ¹. 

Patient position

• patient is supine with no rotation of the shoulders and hips
• remove any radiopaque items (e.g. ECG dots, nappy, shiny decorative clothing)
• take the x-ray in full inspiration
• patient is placed on top of the detector

Technical factors

• anteroposterior projection
• centring point
  • the midsagittal plane (xiphisternum) at the level of the iliac crest
• collimation
  • laterally to the lateral abdominal wall
  • superior to the diaphragm
  • inferior to the inferior pubic rami
  • it is not advised to collimate too tightly laterally in case of missing bowel loops and/or organs ²
• orientation
  • portrait
• detector size
  • will vary depending on the child's body habitus
• exposure ³
  • 60-75 kVp
  • 2-10 mAs
• SID
  • 100 cm
• grid
  • ​if patient thickness is above 10cm, use of a grid is advisable ³

Image technical evaluation

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

Practical points

• paediatric patients may feel uncomfortable when bony landmarks are felt for, therefore an appropriate explanation to the patient beforehand is ideal for improving patient comfort
• to achieve sufficient inspiration, using child-appropriate language will be useful
  • e.g. 'breathe in, you are about to go diving underwater!', 'breathe in, you are about to blow out a birthday candle!'

Immobilisation techniques

It is important for the image to be free from movement artefact and rotation to avoid repeated x-rays.

• it may be necessary for the parent or radiographer to hold the patient in position
• sometimes it is only necessary to keep the child's arms away from the abdominal area; in these cases, sandbags, pillows or velcro straps could be used to keep the arms down 
• techniques will vary based on the department