Calcaneus Axial (Plantodorsal) is a radiography positioning projection of the Lower Extremity. Foot dorsiflexed, CR angled 40° cephalad through plantar surface. SID 40". The centering point is located plantar surface of the calcaneus with foot dorsiflexed against ir.. The central ray is angled 40 degrees cephalad, entering the plantar surface at the base of the third metatarsal and exiting just distal to the lateral malleolus.. Image-quality criteria include entire calcaneus visible including tuberosity and anterior process., plantar and dorsal surfaces clearly demonstrated.. Standard exposure ranges from 60 to 70 kVp, 4 to 8 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Calcaneal tuberosity in profile.
- Anterior process of the calcaneus.
- Posterior, middle, and anterior articular facets.
- Medial and lateral processes of the calcaneus.
- Talocalcaneal joint articulation.
- Talocalcaneal (subtalar) joint.
Patient preparation
- Verify patient identity using two identifiers.
- Remove footwear, socks, and any radiopaque foot jewelry.
- Position the patient supine or seated with the leg extended.
- Place the affected foot on the IR with the plantar surface facing the tube.
- Dorsiflexe the foot to place the plantar surface perpendicular to the IR.
Position & centering point
Plantar surface of the calcaneus with foot dorsiflexed against IR.
Central ray
Angled 40 degrees cephalad, entering the plantar surface at the base of the third metatarsal and exiting just distal to the lateral malleolus.
Exposure / technique
- kVp
- 60–70
- mAs
- 4–8
- SID
- 40" (102 cm)
- Notes
- CR angled 40 degrees cephalad. Patient may wear an ankle support if needed.
Image-quality criteria
- Entire calcaneus visible including tuberosity and anterior process.
- Plantar and dorsal surfaces clearly demonstrated.
- Posterior, middle, and anterior articular facets shown.
- Medial and lateral processes visible without superimposition.
- Bone trabeculae sharp, no motion artifact.
- Collimation: include the entire calcaneus from tuberosity to talocalcaneal joint.
Common errors / ARRT traps
- 1 Insufficient CR angulation (less than 40 degrees) fails to open the posterior facet.
- 2 Plantarflexion instead of dorsiflexion closes the view of the posterior structures.
- 3 Off-centered CR clips the calcaneal tuberosity.
- 4 Foot rotated medially or laterally distorts the axial projection.
Clinical indications
- Suspected calcaneal fracture or stress fracture.
- Evaluation of calcaneal spur or plantar fasciitis.
- Assessment of posterior heel pain or bone lesion.
Aligned to the current ARRT Radiography Content Specifications.