| Term | Definition |
| Foot AP / AP Axial central ray: | (1) Axial: 10 degrees toward the heel entering the
base of the third metatarsal
(2) AP: perpendicular to the IR and
entering the base of the third metatarsal |
| Foot AP / AP Axial structures shown: | an AP (dorsoplantar) projection of the tarsals anterior
to the talus, metatarsals, and phalanges |
| Foot AP / AP Axial evaluation criteria: | - Anatomy from toes to tarsals; may include portions of talus and calcaneus
- Axial projection resulting in improved demonstration of IP, MTP, and TMT joint spaces |
| Foot AP Oblique Medial / Lateral rotation central ray: | perpendicular to the IR and entering the base of the third metatarsal |
| Foot AP Oblique Medial / Lateral rotation structures shown: | - the interspaces of the cuboid and the calcaneus
- the cuboid and the 4th and 5th metatarsals
- the cuboid and the lateral cuneiform, and the talus and the navicular bone
- the cuboid and sinus tarsi is shown in profile |
| Foot AP Oblique Medial / Lateral rotation evaluation criteria:
- Sinus tarsi
- Lateral TMT and intertarsal joints | - entire foot, from toes to heel
- 3rd through 5th MT free of superimposition
- 1st and 2nd MT superimposed on medial and
intermediate cuneiforms
- navicular, lateral cuneiform, and cuboid with less superimposition
- tuberosity of the 5th MT |
| Foot LATERAL Mediolateral central ray: | perpendicular to the base of the third metatarsal |
| Foot LATERAL Mediolateral structures shown: | the entire foot in profile, the ankle joint, and the distal ends of the tibia and fibula |
| Foot LATERAL Mediolateral evaluation criteria: | - entire foot and distal leg
- superimposed plantar surfaces of the MT heads
- fibula overlapping the posterior portion of the tibia
- tibiotalar joint |
| Calcaneus Axial Plantodorsa central ray: | - the central ray enters near the base of the 3rd MT
- directed to the midpoint of the IR at a CEPHALIC angle (entering the plantar surface and toward the heel) of 40 degrees to the long axis of the foot |
| Calcaneus Axial Plantodorsa structures shown: | an axial projection of the calcaneus |
| Calcaneus Axial Plantodorsa evaluation criteria: | - calcaneus and subtalar joint
- the 1st or 5th MT not projected to the sides of foot
- anterior portion of the calcaneus with brightness similar to the posterior portion; otherwise, two images may be needed for the two regions of thickness |
| Calcaneus Axial Dorsoplantar central ray: | - enters the dorsal surface of the ankle joint
- directed to the midpoint of the IR at a CAUDAL angle (enters posterior surface and toward the heel) of 40 degrees to the long axis of the foot. |
| Calcaneus Axial Dorsoplantar structures shown: | an axial projection of the calcaneus and the subtalar
joint |
| Calcaneus Axial Dorsoplantar evaluation criteria: | - calcaneus and the subtalar joint
- sustentaculum tali
- calcaneus not rotated—the 1st or 5th MT not projected to the sides of the foot
- anterior portion of the calcaneus with brightness similar to the posterior portion |
| Calcaneus Lateral Mediolateral central ray: | - perpendicular to the calcaneus
- center about 1 inch distal to the medial malleolus
- this places the central ray at the subtalar joint |
| Calcaneus Lateral Mediolateral structures shown: | the ankle joint and the calcaneus in lateral profile |
| Calcaneus Lateral Mediolateral evaluation criteria: | - calcaneus, including ankle joint and adjacent tarsals
- no rotation of the calcaneus
- tuberosity in profile
- sinus tarsi open
- calcaneocuboid and talonavicular joints open |
| Ankle AP central ray: | perpendicular through the ankle joint at a point midway between the malleoli |
| Ankle AP structures shown: | a true AP projection of the ankle joint, the distal ends of the tibia and fibula, and the proximal portion of the
talus |
| Ankle AP evaluation criteria:
- no overlapping of the medial talomalleolar joint | - medial and lateral malleoli
- talus with proper brightness
- normal overlapping of the tibiofibular articulation with the anterior tubercle slightly superimposed over the fibula
- talus slightly overlapping the distal fibula
- tibiotalar joint space |
| Ankle Mediolateral central ray: | perpendicular to the ankle joint, entering the medial malleolus |
| Ankle Mediolateral structures shown: | a true lateral projection of the lower 3rd of the tibia
and fibula; the ankle joint; and the tarsals, including the base of the 5th metatarsal |
| Ankle Mediolateral evaluation criteria:
- 5th MT base and tuberosity should be seen to check for Jones fracture | -distal tib/fib, talus, calcaneus, and adjacent tarsals
- ankle in true lateral position
- tibiotalar joint well visualized, with the medial and lateral talar domes superimposed
- fibula over the posterior half of the tibia |
| Ankle Lateromedial central ray: | perpendicular through the ankle joint, entering 12 inch (1.3 cm) superior to the lateral malleolus |
| Ankle Lateromedial structure shown: | a lateral projection of the lower third of the tibia and
fibula, the ankle joint, and the tarsals |
| Ankle Lateromedial evaluation criteria: | -distal tib/fib, talus, calcaneus, and adjacent tarsals
- ankle in true lateral position
- tibiotalar joint well visualized, with the medial and lateral talar domes superimposed
- fibula over the posterior half of the tibia |
| Ankle AP Oblique Medial rotation central ray: | perpendicular to the ankle joint, entering midway between the malleoli |
| Ankle AP Oblique Medial rotation structure shown: | - the 45-degree medial oblique projection
shows the distal ends of the tibia and fibula, parts of which are often superimposed over the talus
- the tibiofibular articulation also should be shown |
| Ankle AP Oblique Medial rotation evaluation criteria: | -ankle joint centered to exposure area
- distal tibia, fibula, and talus
- proper 45-degree rotation of ankle
- tibiofibular articulation open
- distal tibia and fibula overlap some of the talus |
| Ankle Mortise Joint AP Oblique Medial rotation central ray: | Perpendicular, entering the ankle joint
midway between the malleoli |
| Ankle Mortise Joint AP Oblique Medial rotation structures shown: | - the entire ankle mortise joint should be
shown in profile
- the 3 sides of the mortise joint should be visualized |
| Ankle Mortise Joint AP Oblique Medial rotation evaluation criteria: | - distal tibia, fibula, and talus
- proper 15- to 20-degree rotation of ankle
- talofibular articulation open
- tibiotalar articulation open
- no overlap of the anterior tubercle of the tibia and the superolateral portion of the talus with the fibula |
| Ankle AP Oblique Lateral rotation central ray: | - perpendicular, entering the ankle joint midway between the malleoli |
| Ankle AP Oblique Lateral rotation structures shown: | the lateral rotation oblique projection is useful in determining fractures and showing the superior aspect of the calcaneus |
| Ankle AP Oblique Lateral rotation evaluation criteria: | - distal tibia, fibula, and talus
- tibiotalar joint
- calcaneal sulcus (superior portion of calcaneus) |
