RAD141 – Chap 7 – Foot Projections

Question Answer
Should screens or grids be used on foot projections? regular screens, no grid
What is the SID for foot projections? 40 inches
What is proper collimation for a foot projection? entire foot s/b demonstrated; lateral should include at least 1 inch of distal tibia-fibula
What are the routine foot projections? Supplementary? Routine -> AP, medial oblique, lateral; supplementary – lateral toe
What is the patient position for the AP foot? patient either supine or sitting on table; flex knee and place plantar surface of affected foot flat on cassette; if available use lead to block off the other half of the film
What size film is used for an AP foot? 1/2 of 10 x 12
How should the tube and CR be angled for AP foot? tube angulation -> 10 degress cephalic toward the long axis of the leg; CR position -> base of the 3rd metatarsal
What are special considerations for an AP foot? a high arch requires more angle (15 deg); low arch nearer 5 degrees to be perpendicular to metatarsals; for foreign body, CR s/b perpendicular to IR w/no CR angle
What is the patient position for an oblique foot? Patient sits are lays on the table, knee flexed, plantar surface of foot on table; rotate foot (with leg) medially approx 30 deg from the AP position
What film size s/b used for an oblique foot? 1/2 of a 10 x 12
What is the tube angulation and CR position for an oblique foot? tube angulation is perpendicular to the film; CR is base of the 3rd metatarsal
What is the patient position for a lateral foot? lateral recumbent position (pilllow for head, affected side down); flex knee about 45 deg; place opposite leg behind injured one; place plantar surface perpendicular to film, foot centered to film; slightly elevate knee w/sponge (to ensure true lateral)
What film size s/b used for a lateral foot? 8 x 10
How should the tube be angle and central ray be positioned for a lateral foot? tube angulation s/b perpendicular to film; CR through mid-tarsals
What is the patient position for a lateral toe? same a lateral foot; extend the affected toe as much as possible (tongue depressor or tape may be required)
What is an extra consideration of lateral toe is requested in addition to the routine foot series? radiograph the lateral foot on a 10 x 12 on 1/2 the film (using lead strips to leave unexposed film); put the lateral toe on the other half of the 10 x 12
What is the film size for a lateral toe? if requested alone, use an 8 x 10
How should the tube and CR be angled for a lateral toe? tube should be angled perpendicular to film; CR s/b positioned to the PIP of affected toe