Positioning for Toes, Foot, Calcaneus & Ankle (RADS 320)

SID for toes, foot, calcaneus & ankle

40 in.

kVp for toes, foot, calcaneus & ankle

65-75

IR size for toes, foot, calcaneus & ankle

10 x 12 or larger CW or LW

AP Projection of Toes: CR

perpendicular through the 3rd MTP when demonstration of joint spaces is not critical

AP Axial Projection of Toes: CR

directed 15 degrees posteriorly toward the heel (perpendicular if on sponge 15 degrees) entering at the 3rd MTP to open joint spaces

AP Axial of Toes: SS

the 14 phalanges of the toes; the distal portions of the metatarsals and the IP joints

AP Axial / Dorsoplantar of toes: Patient Position

rest plantar surface of foot in the IF or place a 15 degree wedge sponge under foot with toes elevated

AP oblique projection (medial rotation): Patient Position

rotate foot medially so that plantar surface forms a 30-45 degree angle to the plane of the IR (digits 1 & 2 medially; 3-5 laterally)

AP oblique, medial rotation of toes: CR

perpendicular and enters at the 3rd metatarsophalangeal joint (MTP)

AP oblique, medial rotation of toes: SS

shows the toes and the distal portion of the metatarsals rotated medially

For lateral projections of digits 1-2 of the toes rotate the foot...

medially resting on medial surface

For lateral projections of digits 3-5 of the toes rotate the foot...

laterally resting on lateral surface

Lateral Projections of Toes: CR

directed perpendicular to midpoint of IR; Great Toe - at IP; 2-5 at PIP

Lateral Projections of Toes: SS

lateral projection of phalanges of the toe and the IP articulations projected free of the other toes

Lateral Projections of Toes: Collimation

1 in on all sides and 1 in proximal to the MTP joint

AP Axial Foot: CR

10 degrees cephalad entering at the base of the 3rd metatarsal (placing the CR perp. to the metatarsals)

AP Axial Foot: SS

AP (dorsoplantar) projection of the tarsals anterior to the talus, metatarsals, and phalanges

AP Axial Foot is used for:

-localizing foreign bodies

-determining the locations of fragments in fractures of the metatarsals and anterior tarsals

-performing general surveys of the bones of the foot

AP oblique projection (medial rotation) of the Foot: Patient Position

plantar surface of the foot forms 30 degree angle with IR medially

AP oblique projection (medial rotation) of the Foot: CR

Perpendicular to base of 3rd Metatarsal

AP oblique projection (medial rotation) of the Foot: SS

joint spaces between the cuboid & calcaneus, cuboid & 4th and 5th metatarsal, cuboid & lateral cuneiform, and talus & navicular bone

- cuboid shown in profile and sinus tarsi well shown

Mediolateral Projection of Foot: Patient Position

dorsiflex foot to form 90 degree angle with tib/fib, plantar surface perpendicular to IR

Mediolateral Projection of Foot: CR

perpendicular to base of 3rd metatarsal (don't want to see 4th and 5th metatarsals or the cuboid)

Mediolateral Projection of Foot: SS

the entire foot in profile, the ankle joint, and the distal ends of the tibia and fibula

Lateral Projection Longitudinal Arch Weight Bearing Method of Foot: CR

perpendicular to a point just above the base of 3rd metatarsal

What is the purpose of the Lateral Projection Longitudinal Arch Weight Bearing Method of the Foot?

Used to show the structural status of the longitudinal arch where both the right and left sides are examined for comparison

AP Axial Projection Weight Bearing Method Standing: SID

48 in to reduce magnification

AP Axial Projection Weight Bearing Method Standing: CR

10 degrees toward heel (cephalic) enters between feet at level of base of 3rd metatarsal

AP Axial Projection Weight Bearing Method Standing: SS

a weight bearing AP axial projection of both feet, permitting accurate evaluation and comparison of the tarsals and metatarsals

Axial Projection (Plantodorsal) of Calcaneus: CR

angle 40 degrees cephalic and enters the plantar surface of the foot at the base of the 3rd metatarsal and exits the dorsal surface of the ankle joint

Axial Projection (Plantodorsal) of Calcaneus: SS

an axial projection of the calcaneus, talocalneal joint (subtalar joint), and the sustentaculum tali in profile

Axial Projection (dorsoplantar) of Calcaneus: Patient Position

Prone with sandbags placed under ankle to dorsiflex the ankle; foot is perpendicular to the tabletop

Axial Projection (dorsoplantar) of Calcaneus: CR

40 degrees caudal to long axis of foot enters the dorsal surface of the ankle joint; exits the plantar surface of the foot

Mediolateral Projection of Calcaneus: CR

1" distal to medial malleolus which places the CR at the subtalar joint & perpendicular to IR

AP Ankle: CR

Perpendicular to point midway between malleoli

AP Ankle: Position

Patient seated supine w/ affected limb extended adjust the ankle joint in the anatomic position (foot pointing straight up)

-flex the ankle and foot to place the long axis of the foot in the vertical position

For the AP ankle what joints are not open?

the inferior tibiofibular joint and the talofibular joint indicating that the patient had no ruptured ligaments

Mediolateral projection of Ankle: CR

enters at the medial malleolus

Mediolateral projection of Ankle: SS

a true lateral projection of the lower third of the tibia and fibula, the ankle joint, and the tarsals including the base of the fifth metatarsal

Lateromedial Projection of Ankle: CR

perpendicular through the ankle joint 1/2 inch superior to lateral malleolus

AP oblique projection (medial rotation) of Ankle: CR

perpendicular entering midway between malleoli

AP oblique projection (medial rotation) of Ankle: degree of obliquity

45 degrees medial

The 45 degree medial oblique projection of the ankle shows:

the distal ends of the tibia and fibula, parts of which are often superimposed over the talus and the tibiofibular joint is open

AP oblique projection (medial rotation) of the Mortise Joint Ankle: CR

perpendicular to mid malleoli

AP oblique projection (medial rotation) of the Mortise Joint Ankle: degree of obliquity

15-20 degrees medially

The mortise joint oblique shows:

the three sides of the mortise joint should be visualized

Stress views of the ankle

to verify presence of ligamentous tear

Stress view of the ankle: CR

perpendicular entering midway between the malleoli

AP Projection Weight Bearing Method of the Ankle is done to...

identify ankle joint space narrowing with weight-bearing

AP Projection Weight Bearing Method of the Ankle: Patient Position

upright on a low platform that has an IR groove or use blocks to elevate the feet to the level of the x-ray

AP Projection Weight Bearing Method of the Ankle: CR

perpendicular to center of IR entering at the level of the ankle joints

Lateral Projection Weight Bearing Method of the Ankle: CR

perpendicular through the ankle joint 1/2 in superior to lateral malleolus