Foot - Composite DP

Radiographic Positioning

Adult Foot - Composite Dorsoplantar Projection

Other related pages of interest Applied Radiography Radiographic Anatomy Radiographic Protocols

Name of projection	Foot - Composite Dorsoplantar (Phantom foot)
Area Covered	Phalanges, metatarsals, navicular, cuniforms, cuboid, talus, calcaneus. The hindfoot is seen free of superimposition of the tibia and fibula.
Pathology shown	Fractures, dislocation, foreign body, joint space abnormalities
Radiographic Anatomy	Foot Radiographic Anatomy
IR Size & Orientation	24 x 30 cm Portrait
Film / Screen Combination	Detail (CR and DR as recommended by manufacturer)
Bucky / Grid	No
Filter	No
Exposure	57 kVp 1.5 mAs for each exposure
FFD / SID	100 cm
Central Ray	1st Exposure: 15° posterior, directed to the base of the 3rd metatarsal 2nd Exposure: 25° anterior, directed to the level of the lateral maleolus
Collimation	Outer skin margins of foot on 4 sides
Markers	Distal and Lateral Marker orientation AP
Shielding	Gonadal (check your department's policy guidelines)
Respiration	Not applicable
Positioning	1st Exposure Place the cassette on the floor of the exam room Place the foot on the IR parallel to its long axis Place the plantar surface of the foot against the IR The unaffected foot should be a step behind the affected foot Center to the base of the 3rd metatarsal It is essential that the foot does not move between exposures. Hold the patient's foot firmly and have them take a giant step forward. 2nd Exposure Align the leg to the long axis of the foot The entire plantar surface of the foot against the IR Center to the level of the mid-maleolus
Critique PACEMAN	Positioning No rotation is evidenced by The joint between the medial and intermediate cuneiformsis open (this is closed when the foot is rotated) First metatarsal shaft has equal concavity on both sides Nearly equal spacing between 2nd to 5th metatarsals There should be overlap of 2nd to 5th metatarsal bases. Area Covered Phalanges, metatarsals, navicular, cuniforms, cuboid, talus, calcaneus, and surrounding foot soft tissue. Collimation Centre: The base of the third metatarsal Shutter A: Open to include the outer skin margins of the lateral and medial sides of the foot Shutter B: Open to include the soft tissue of the toes and the proximal calcaneus Exposure Soft tissue visualized All skeletal structures have a similar density
Special Notes	The nickname for this projection, "phantom foot", stems from the appearance of the radiograph. The hind foot is demonstrated free of superimposition of the leg, giving the appearance of a phantom foot. This projection can only be done using film or CR. It cannot be done with DR due to the necessity of two exposures to create one image. Be sure to have ample room to move the tube around the patient as they must remain stationary during the move. Permit the patient to hold onto a chair or some type of support because the necessary stance may be difficult for some patients.