Pediatric ankle (lateral view)

The lateral ankle view for pediatrics is one of three views to examine the distal tibia, distal fibula, proximal talus and proximal fifth metatarsal.

Indications

The lateral projection demonstrates the ankle joint orthogonal to the AP ankle view. It is useful in diagnosing fractures, joint space abnormalities and localizing foreign bodies in pediatric patients.

Patient position

• the patient is in a lateral recumbent position with the lateral aspect of the ankle in contact with the detector

• affected foot in dorsiflexion

Technical factors

• lateral projection

• centering point

  • the midpoint of the lateral and medial malleoli

• collimation

  • laterally to the skin margins

  • superior to examine the distal third of the tibia and fibula

  • inferior to the proximal aspect of the metatarsals

• orientation

  • portrait

• detector size

  • 18 x 24 cm

• exposure ¹

  • 50-55 kVp

  • 1-2 mAs

• SID

  • 100 cm

• grid

  • no

Image technical evaluation

The talar domes should be seen superimposed to allow for assessment of joint space articulation and the superior surface of the talus. The distal fibula should be superimposed on the posterior aspect of the distal tibia 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 when their affected ankle 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