Toes AP Oblique is a radiography positioning projection of the Lower Extremity. Foot rotated 30-45 degrees, medially for toes 1-3 and laterally for toes 4-5. CR perpendicular. SID 40". The centering point is located MTP joint in question (Bontrager) or 3rd MTP joint (Merrill's). Bontrager rotates medially for toes 1-3 and laterally for toes 4-5. The central ray is perpendicular in a 30-45 degree oblique, to the MTP joint in question (Bontrager) or the 3rd MTP joint (Merrill's). Image-quality criteria include all five toes visible in a 30-45 degree oblique projection, correct obliquity: one side of the shafts more concave; soft tissues of the toes overlap. A sample technique is 63 kVp with DR 0.9 or CR 2 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- All five toes in oblique projection.
- IP and 2nd to 5th MTP joints open; 1st MTP not always open (Merrill's).
- Distal metatarsals.
- First through fifth metatarsal heads.
Patient preparation
- WARNING: with possible spinal injury or severe trauma, do not attempt to move the patient; do not rotate a severely injured part or remove splints (Bontrager). Merrill's: do not attempt true AP or lateral positioning of a severely injured limb; take two projections 90 degrees apart, moving it as little as possible, and move the IR and tube if the patient cannot reach the position.
- Verify patient identity using two identifiers.
- Remove footwear, socks, and any radiopaque foot jewelry.
- Position the patient supine or seated with the knee flexed.
- Place the affected foot flat on the IR.
- Rotate the leg and foot medially (inward) 30-45 degrees; for the 4th and 5th toes, rotate laterally.
- Support the raised part of the foot with a 45-degree radiolucent block.
Position & centering point
MTP joint in question (Bontrager) or 3rd MTP joint (Merrill's). Bontrager rotates medially for toes 1-3 and laterally for toes 4-5.
Central ray
Perpendicular in a 30-45 degree oblique, to the MTP joint in question (Bontrager) or the 3rd MTP joint (Merrill's).
Exposure / technique
- kVp
- 63
- mAs
- DR 0.9 / CR 2
- SID
- 40" (102 cm)
- Notes
- Rotate the leg and foot inward (medially) 30-45 degrees; for the 4th and 5th toes, rotate laterally. Sample technique: DR 0.9 / CR 2 mAs at 63 kVp, 40 in SID, for a 1.5 cm part. Adjust for your equipment.
kVp and mAs are sample values. Use caution when applying them in your department.
Image-quality criteria
- All five toes visible in a 30-45 degree oblique projection.
- Correct obliquity: one side of the shafts more concave; soft tissues of the toes overlap.
- Metatarsal heads side by side with little or no overlap.
- Distal metatarsals clearly demonstrated.
- Bone trabeculae sharp, no motion artifact.
- Collimation: 1 inch on all sides of toes.
Common errors
- 1 Obliquity wrong: shafts not more concave on one side, soft tissues not overlapping.
- 2 Metatarsal heads overlapping instead of side by side.
- 3 CR not centered to the MTP joint in question (Bontrager) or the 3rd MTP (Merrill's).
Clinical indications
- Fractures or dislocations of the phalanges of the digits in question.
- Pathologies such as osteoarthritis and gout, especially in the first digit.