Paediatric scaphoid (axial view)

The scaphoid axial view in paediatrics examines the scaphoid bone in its true anatomical position. Since minimising radiation dose is essential in paediatric imaging, one posteroanterior angled view of the scaphoid is usually sufficient. The scaphoid bone begins ossification at age 5 years and completes around ages 13 to 15 years ¹, therefore it is important to only perform this radiograph on children greater than five-years-old.

Indications

This scaphoid view allows for visualisation of the entire scaphoid and is thus useful for identifying any subtle fractures through the distal, middle or proximal scaphoid. 

Patient position

• patient is either seated alongside the table or supine with arm outstretched
• the affected wrist is placed with palm on the image receptor
• affected wrist in ulnar deviation; as much as the child can achieve

Technical factors

• posteroanterior axial projection
• centring point
  • anatomical snuffbox 
  • the central beam is angled 15-30° proximally along the long axis of the arm towards the elbow
• collimation
  • laterally to the skin margins
  • distal to the base of the first metacarpal 
  • proximal to the radiocarpal joint
• orientation  
  • portrait
• detector size
  • 18 cm x 24 cm
• exposure ²
  • 40-52 kVp
  • 1-2 mAs
• SID
  • 100 cm
• grid
  • no

Image technical evaluation

The scaphoid should appear elongated and free from superimposition. Adjacent carpal joint spaces should appear open ³.

Practical points

Preparing the room beforehand (setting up the detector, exposure and preparing lead gowns) is important as paediatric patients may not remain still when their affected wrist is moved onto the detector. If the child is seated, raising or lowering the table can assist with alleviating pain from assuming the required position. Scaphoid fractures often do not allow patients to ulnar deviate, so ensure to only deviate as much as the child can tolerate. 

Immobilisation techniques

It is important for the radiograph to 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
• techniques will vary based on the department
• distraction techniques can be utilised to avoid scattered radiation to parents and staff ⁴