Nasal Bones Lateral is a radiography positioning projection of the Skull. True lateral nasal bones. SID 40". CR perpendicular to IR. The centering point is located approximately 1/2 inch distal to the nasion, over the nasal bones. mid-sagittal plane parallel to ir.. The central ray is horizontal, perpendicular to ir. centered ~1/2 inch distal to the nasion.. Image-quality criteria include nasal bones visualized in profile without overlap., sharp outline of nasal bone edges.. Standard exposure ranges from 55 to 65 kVp, 4 to 8 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Nasal bones in profile, thin linear appearance.
- Nasion and nasal bridge outlined.
- Nasal septum superimposed on nasal bones.
- Anterior nasal spine.
- Frontal process of maxilla.
- Perpendicular plate of ethmoid.
Patient preparation
- Verify patient identity.
- Remove glasses, earrings, hairpins.
- Position patient prone or upright with affected side against IR.
- Align mid-sagittal plane parallel to IR; interpupillary line perpendicular.
- IOML (infraorbitomeatal line) parallel to long axis of IR.
- Suspend respiration during exposure.
Position & centering point
Approximately 1/2 inch distal to the nasion, over the nasal bones. Mid-sagittal plane parallel to IR.
Central ray
Horizontal, perpendicular to IR. Centered ~1/2 inch distal to the nasion.
Exposure / technique
- kVp
- 55–65
- mAs
- 4–8
- SID
- 40" (102 cm)
- Notes
- Low kVp for small anatomic structure. Small focal spot required.
Image-quality criteria
- Nasal bones visualized in profile without overlap.
- Sharp outline of nasal bone edges.
- No rotation: nasal bones appear as thin linear structures.
- Nasion clearly visualized.
- Nasal septum superimposed on nasal bones.
- Minimal surrounding soft tissue blur.
Common errors / ARRT traps
- 1 Rotation: nasal bones appear thick or asymmetrical.
- 2 CR not at nasion: nasal bones off-center on IR.
- 3 Excessive mAs: degraded detail of thin bone.
- 4 Tilt: nasal bones appear foreshortened.
- 5 IOML not parallel: geometric distortion of nasal anatomy.
Clinical indications
- Nasal bone fracture evaluation.
- Trauma to nasal dorsum assessment.
- Post-operative nasal bone follow-up.
- Evaluation of nasal deformity.
Aligned to the 2025 ARRT Content Specifications.