Pediatric finger (PA view)

The posteroanterior finger view for pediatrics is part of a two view series examining the distal metacarpal, distal, middle and proximal phalanges of the finger of interest. 

Indications

This projection demonstrates the metacarpal and interphalangeal joint spaces in their natural anatomic position. It is useful for diagnosing fractures and localizing foreign bodies in pediatric patients. 

Patient position

• patient is either seated alongside the table or supine with arm outstretched
• palmar aspect of the hand placed on the detector
• fully extend finger(s) of interest in order to open the interphalangeal spaces

Technical factors

• posteroanterior projection
• centering point
  • approximately over the proximal interphalangeal joint
• collimation
  • laterally to the adjacent fingers 
  • proximal to include the carpometacarpal joint
  • distal to the tips of the distal phalanges 
• orientation  
  • portrait
• detector size
  • 18 cm x 24 cm
• exposure ¹
  • 40-46 kVp
  • 0.8-2 mAs
• SID
  • 100 cm
• grid
  • no

Image technical evaluation

Finger is visualized with open interphalangeal joints, no rotation is demonstrated by equal metacarpal midshaft concavities ². No soft tissue overlap between fingers and the finger of interest is correctly labeled and identified. 

Practical points

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

Immobilization 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 utilized to avoid scattered radiation to parents and staff ³

Placing radiolucent items such as a clear clipboard on top of the child's hand can be useful for keeping the child's finger and hand flat and still for the posteroanterior view. However, placing items on top of the child's hand should be used only if it will not injure the child further.