Calcaneus Lateral (Mediolateral) is a radiography positioning projection of the Lower Extremity. Patient lateral recumbent on affected side, CR perpendicular to calcaneus. SID 40". The centering point is located 1 inch inferior to the medial malleolus, with the lateral border of the foot on the IR. The central ray is perpendicular to the calcaneus in true lateral projection. Image-quality criteria include no rotation: superior talus superimposed, lateral malleolus over the posterior half of tibia and talus, talocalcaneal articulation clearly demonstrated. A sample technique is 70 kVp with DR 1.1 or CR 2.2 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Calcaneus in true lateral profile.
- Calcaneal tuberosity in profile.
- Talocalcaneal joint articulation open.
- Talar dome and neck.
- Distal tibia-fibula above the talus, with the lateral malleolus over the posterior half of the tibia and talus.
Patient preparation
- WARNING: with possible spinal injury or severe trauma, do not attempt to move the patient; do not rotate a severely injured part or remove splints (Bontrager). Merrill's: do not attempt true AP or lateral positioning of a severely injured limb; take two projections 90 degrees apart, moving it as little as possible, and move the IR and tube if the patient cannot reach the position.
- Verify patient identity using two identifiers.
- Remove footwear, socks, and any radiopaque foot jewelry.
- Position the patient lateral recumbent on the affected side.
- Place the affected foot on the IR with the lateral border down.
- Flex the knee about 45 degrees; place the other leg behind the injured limb.
- Support the knee and leg so the sole is perpendicular to the IR; dorsiflex the foot to 90 degrees.
Position & centering point
1 inch inferior to the medial malleolus, with the lateral border of the foot on the IR.
Central ray
Perpendicular to the calcaneus in true lateral projection.
Exposure / technique
- kVp
- 70
- mAs
- DR 1.1 / CR 2.2
- SID
- 40" (102 cm)
- Notes
- Position patient on affected side. Flex knee if needed for comfort. Sample technique: DR 1.1 / CR 2.2 mAs at 70 kVp, 40 in SID, for a 5 cm part. Adjust for your equipment.
kVp and mAs are sample values. Use caution when applying them in your department.
Image-quality criteria
- No rotation: superior talus superimposed, lateral malleolus over the posterior half of tibia and talus.
- Talocalcaneal articulation clearly demonstrated.
- Calcaneal tuberosity shown in profile.
- Tarsal sinus and calcaneocuboid joint open.
- Ankle joint included proximally.
- Collimation: 1 inch on all sides of calcaneus, include heel and base of 5th metatarsal.
Common errors
- 1 Rotation: superior portions of the talus not superimposed.
- 2 Foot not dorsiflexed so the sole is at a right angle to the leg.
- 3 CR not directed 1 inch inferior to the medial malleolus.
- 4 Long axis of the foot not parallel to the IR.
Clinical indications
- Suspected calcaneal fracture or stress fracture.
- Bony lesions of the calcaneus, talus and talocalcaneal joint.
- Assessment of talocalcaneal articulation.