Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

This article discusses radiographic positioning to show the heel and ankle for the Radiologic Technologist (X-Ray Tech).

Heel Axial (Plantodorsal)

Purpose and Structures Shown Clear demonstration of calcaneus and subtalar joint. No rotation of calcaneus. Anterior portion of calcaneus without excessive density over posterior portion.

Position of patient Supine or seated position with legs fully extended.

Position of part Radiologic technologists may place the IR under patient’s ankle, centered to midline of ankle. Place long strip of gauze around ball of foot. Have patient pull gauze to hold ankle in right angle. If patient’s ankle cannot be dorsiflexed enough to place plantar surface of foot perpendicular to IR, raise leg on sandbags to obtain the correct position.

Central ray Directed to midpoint of IR at cephalic angle of 40 degrees to long axis of foot. CR enters base of third metatarsal.

Heel Axial (Dorsoplantar)

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown the x-ray should clearly demonstrate calcaneus and subtalar joints.

Position of patient Prone position.

Position of part X-ray technologists can help elevate patient’s ankle on sandbags. Adjust height and position of sandbags so patient can dorsiflex ankle enough to place long axis of foot perpendicular to tabletop. Place IR against plantar surface of foot and support it in position with sandbags or a portable IR holder.

Central ray Midpoint of IR at caudal angle of 40 degrees to long axis of foot.
CR enters proximal anterior calcaneus.

Heel PA Axial Oblique (Lateral Rotation)

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown Middle and posterior articulations of subtalar joint. “End-on” image of sinus tarsi. Unobstructed projection of lateral malleolus.

Position of patient Lie on affected side in lateral position. Flex uppermost knee. Support knee as needed to prevent forward rotation of body.

Position of part Ask patient to extend affected limb. Roll limb slightly forward from lateral position. Wedge under heel. Heel should be slightly elevated about 1-2 inches (3.8 cm) from exact lateral position. Ball of foot (the metatarsophalangeal area) angled forward approximately 25 degrees.

Central ray Directed to ankle joint at a double angle of 5 degrees anterior and 23 degrees caudal.

Heel AP Axial Oblique (Broden Method)

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown To demonstrate posterior articular facet of calcaneus to determine presence of joint involvement in cases of comminuted fracture. Anterior portion of the posterior facet is shown best in the 40-degree projection. 10-degree projection shows posterior portion. Articulation between the talus and sustentaculum tali (middle facet) is usually shown best in one of the intermediate projections.

Position of patient Supine position. Adjust small sandbag under each knee.

Position of part Dorsiflex 90 degrees, if needed, loop a strip of bandage around ball of the foot. Have patient grasp ends of bandage and dorsiflex foot enough to obtain right-angle flexion at the ankle joint. Ask patient to maintain flexion for exposure. (see Heel Axial Plantodorsal). With patient’s ankle joint maintained in right-angle flexion, rotate the leg and foot 45 degrees medially, and rest the foot against a 45-degree foam wedge.

Central ray Angled cephalad at 40, 30, 20, and 10 degrees, respectively. Four separate images are obtained.
For each image, direct CR to a point 2 or 3 cm caudoanteriorly to lateral malleolus, to midpoint of an imaginary line extending between most prominent point of lateral malleolus and base of the fifth metatarsal.

Heel Lateral Rotation (Broden Method)

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown Clear demonstration of subtalar joint. Posterior facet of calcaneus. Articulation between talus and sustentaculum tali.

Position of patient Supine position. The radiologic technologists may adjust small sandbag under each knee of the patient.

Position of part Ankle joint held in right-angle flexion. Rotate leg and foot 45 degrees laterally. Foot may rest against 45 degrees foam wedge.

Central ray Directed to point 2 cm distal and 2 cm anterior to medial malleolus, at cephalic angle of 15 degrees for first exposure. Two or three images made with a 3 or 4 degrees difference in CR angulation.

Heel Lateromedial Oblique Projection (Isherwood Method)

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown Clear demonstration of talar articular surface of calcaneus. Anterior subtalar articular surface. Oblique projection of tarsals.

Position of patient Semi-supine or seated, turned away from side being examined. Ask patient to flex knee enough to place ankle joint in nearly right angle flexion. Lean leg and foot medially.

Position of part Medial border of foot resting on IR. Place a 45 degrees foam wedge under elevated leg. Adjust leg so that its long axis is in same plane as CR. Adjust foot at right angle. Place support under knee.

Central ray Perpendicular to IR at a point 1 inch (2.5 cm) distal and 1 inch (2.5 cm) anterior to lateral malleolus.

Heel AP Axial Oblique (Isherwood Method)

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown Clear demonstration of posterior articulation of subtalar joint in profile.

Position of patient Supine or seated.

Position of part Ask patient to rotate leg and foot laterally until side of foot and ankle rests against an optional 30-degree foam wedge. Dorsiflex foot, have patient maintain position by pulling on a broad bandage looped around the ball of the foot (see Heel Axial Plantodorsal).

Central ray 10 degrees cephalad at a point 1 inch (2.5 cm) distal to the medial malleolus.

LE-P-30 – Ankle AP

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown AP projection of ankle joint, distal ends of tibia and fibula, and proximal portion of talus.

Position of patient Supine position. Affected limb fully extended.

Position of part Adjust ankle joint in anatomic position to get true AP projection. Flex ankle and foot enough to place long axis of foot in vertical position.

Central ray Perpendicular to IR through the ankle joint at point midway between malleoli.

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Ankle Lateral Mediolateral

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown Demonstrates true lateral projection of lower portion of tibia and fibula, ankle joint, and tarsals.

Position of patient Supine. Turned toward affected side until ankle is lateral.

Position of part Place long axis of IR parallel with long axis of patient’s leg and center it to ankle joint. Lateral surface of foot is in contact with IR. Dorsiflex foot and adjust it in lateral position.  Prevent lateral rotation of ankle.

Central ray Perpendicular to IR at the ankle joint, entering medial malleolus.

Ankle Lateral Lateromedial

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown To get clear lateral image of ankle joint, tibiotalar joint, fibula over posterior half of tibia.

Position of patient Supine Patient turned away from affected side until extended leg is placed laterally.

Position of part Foot in the lateral position. If necessary, place a support under the patient’s knee.

Central ray Perpendicular to IR and through the ankle joint, entering 1/2 inch (1 .3 cm) superior to the lateral malleolus.

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Ankle AP Oblique Medial Rotation

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown Ankle middle articulation and open sinus tarsi Subtalar joint

Position of patient Seated, recumbent, or supine on table. Turn with body weight resting on flexed hip and thigh of unaffected side.

Position of part Rotate leg and foot medially 30 degrees, use a foam wedge if needed. Place support under knee if needed. If patient is recumbent, place another under greater trochanter. Dorsiflex foot, and then invert it if possible. If necessary, have patient maintain position by pulling on strip of bandage looped around ball of foot. (See Heel Axial Plantodorsal).

Central ray 10 degrees cephalad 1 inch (2.5 cm) distal and 1 inch (2.5 cm) anterior to lateral malleolus.

Ankle AP Oblique Lateral Rotation

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown Useful in determining fractures and demonstrating superior aspect of calcaneus. Subtalar joint. Calcaneal sulcus.

Position of patient Seat patient on table with affected leg extended.

Position of part Place plantar surface of patient’s foot in vertical position, and rotate the leg and foot 45 degrees laterally. Rest foot against a foam wedge for support, and center ankle joint to IR.

Central ray Perpendicular to IR entering ankle joint midway between malleoli.

Ankle AP Stress

Which surface of the foot should be in contact with the IR for the recumbent lateral projection of the foot?

Purpose and Structures Shown Obtained after an inversion or eversion injury to verify the presence of a ligament tear.

Position of patient When injury is recent and ankle is acutely sensitive to movement, orthopedic surgeon may inject a local anesthetic into sinus tarsi preceding examination.  The physician adjusts foot when it must be turned into extreme stress and holds or straps it in position for the exposure. The patient usually can hold the foot in the stress position when the injury is not too painful or after he or she has received a local anesthetic by asymmetrically pulling on a strip of bandage looped around the ball of the foot.

Position of part Adjust ankle joint in anatomic position to get true AP projection. Flex ankle and foot enough to place long axis of foot in vertical position.

Central ray Perpendicular to IR through ankle joint at point midway between malleoli.

Video Credit : klhellens

Video Credit : Radiologyinstructor