Bone age (radiograph)

The bone age, hand and wrist PA is a commonly performed examination to determine the radiographic age of the patient via the assessment of growth centres

Patient position

• patient is seated alongside the table
• the non-dominant handis placed, palm down on the image receptor
• shoulder, elbow, and wrist should all be in the transverse plane, perpendicular to the central beam
• the hand and elbow should be at shoulder height which makes radius and ulna parallel (lowering the arm makes radius cross the ulna and thus relative shortening of radius)

Technical factors

• posteroanterior projection
• centring point
  • the mid-metacarpal region of the left hand 
• collimation
  • laterally to the skin margins
  • proximal to include 1/3 of the forearm
  • distal to the tips of the distal phalanges 
• orientation
  • portrait
• detector size
  • 18 cm x 24 cm
• exposure
  • 50-60 kVp
  • 1-5 mAs
• SID
  • 100 cm
• grid
  • no

Image technical evaluation

5th finger is positioned PA, with no rotation as evidenced by the symmetric appearance of the concavities of the phalanges. Interphalangeal and metacarpophalangeal joint spaces of digits 2 to 5 appear open.

The concavity of the metacarpal shafts is equal 1.

Practical points

This is not a technically challenging radiograph, always ensure the fingers are equal distance apart and the detector is high enough to avoid overlap at the wrist.

Assessment is performed with a radiograph of the non-dominant hand with a single DP view that includes the distal radius and ulna and all the fingers. Appearances of the carpal bones, metacarpal, phalanges, radius and ulna are compared to standardised versions in one of two main atlases:

• Greulich & Pyle atlas presents a single standardised image for a range of ages of each gender 
• Tanner-Whitehouse atlas involves the scoring of each carpal bone, the radius and ulna leading to a total score, from which age can be estimated