Skull Lateral is a radiography positioning projection of the Skull. True lateral cranium. SID 40". CR perpendicular to IR. The centering point is located 2" (5 cm) superior to the eam. mid-sagittal plane parallel to ir; interpupillary line perpendicular to ir.. The central ray is horizontal, perpendicular to ir. centered to a point 2" superior to the eam (external auditory meatus).. Image-quality criteria include superimposed mandibular rami (no rotation)., superimposed orbital roofs.. Standard exposure ranges from 70 to 80 kVp, 10 to 25 mAs, at an SID of 40 inches (102 cm).
Patient preparation
- Verify patient identity.
- Remove glasses, earrings, hairpins, dentures, hearing aids.
- Position patient prone or upright with affected side against IR.
- Align mid-sagittal plane parallel to IR; interpupillary line perpendicular to IR.
- IOML (infraorbitomeatal line) parallel to the long axis of the IR.
- Suspend respiration during exposure.
Position & centering point
2" (5 cm) superior to the EAM. Mid-sagittal plane parallel to IR; interpupillary line perpendicular to IR.
Central ray
Horizontal, perpendicular to IR. Centered to a point 2" superior to the EAM (external auditory meatus).
Exposure / technique
- kVp
- 70–80
- mAs
- 10–25
- SID
- 40" (102 cm)
- Notes
- Use a small focal spot for sharper detail of cranial sutures.
Image-quality criteria
- Superimposed mandibular rami (no rotation).
- Superimposed orbital roofs.
- Sella turcica seen in profile.
- Cranium centered on IR with ~1" margin all around.
- Detail of cranial bones, sutures, and sella turcica visible.
- No tilt: TMJs superimposed.
Clinical indications
- Trauma evaluation for skull fractures (linear, depressed, basilar).
- Evaluation of sella turcica for pituitary mass effect.
- Pneumatized sinus evaluation (frontal, sphenoid).
- Pre/post-operative cranial follow-up.
Aligned to the 2025 ARRT Content Specifications.