Toes Lateral is a radiography positioning projection of the Lower Extremity. Affected toe in true lateral on IR, CR perpendicular. SID 40". The centering point is located IP joint of the great toe, or the PIP joint of the affected toe, in true lateral. The central ray is perpendicular to the IR, to the IP joint of the 1st toe or the PIP joint of toes 2-5. Image-quality criteria include affected toe in true lateral with no rotation or overlap of phalanges, great toe separated from the second toe for clear visualization. A sample technique is 63 kVp with DR 0.9 or CR 2 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- The affected toe in true lateral, with adjacent toes held clear.
- Great toe separated from remaining four toes.
- Interphalangeal joints open; MTP joints overlapped (Merrill's).
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.
- Merrill's: lateral recumbent, on the unaffected side for toes 1-2 and the affected side for toes 3-5.
- Bontrager: rotate the leg and foot medially (lateromedial) for toes 1-3, laterally (mediolateral) for toes 4-5.
- WARNING: manipulate toes only if no deformity is apparent (Merrill's). If there is none, flex and separate the other toes with tape, gauze or a tongue blade.
Position & centering point
IP joint of the great toe, or the PIP joint of the affected toe, in true lateral.
Central ray
Perpendicular to the IR, to the IP joint of the 1st toe or the PIP joint of toes 2-5.
Exposure / technique
- kVp
- 63
- mAs
- DR 0.9 / CR 2
- SID
- 40" (102 cm)
- Notes
- Flex and separate the unaffected toes with tape, gauze or a tongue blade to prevent superimposition. 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
- Affected toe in true lateral with no rotation or overlap of phalanges.
- Great toe separated from the second toe for clear visualization.
- True lateral: distal phalanx more concave anteriorly, proximal phalanx more concave posteriorly.
- Other toes flexed out of the field; for toes 3-5 at least the distal phalanx is clear.
- Bone trabeculae sharp, no motion blur.
- Collimation: close to the affected toe.
Common errors
- 1 Failure to achieve true lateral causes phalanx overlap and joint closure.
- 2 Unaffected toes not flexed and separated, leaving superimposition.
- 3 CR not directed to the IP or PIP joint of the affected toe.
Clinical indications
- Trauma evaluation for suspected toe fracture.
- Pathologies such as osteoarthritis and gout, especially in the first digit.