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 |