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 1/2 inch inferior to the nasion (Bontrager), or 1 inch distal to it (Merrill's), over the nasal bones. Mid-sagittal plane parallel to IR. The central ray is perpendicular to IR (horizontal when the patient is erect). Centered 1/2 inch inferior to the nasion (Bontrager). Merrill's uses 1 inch distal to the nasion. Image-quality criteria include nasal bones visualized in profile without overlap, sharp outline of nasal bone edges. A sample technique is 70 kVp with DR 2.5 or CR 5 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Nasal bones in profile, thin linear appearance.
- Frontonasal suture.
- Anterior nasal spine.
- Soft tissue nasal structures.
Patient preparation
- Trauma patient: rule out cervical spine injury before moving the head or neck.
- Verify patient identity.
- Remove glasses, earrings, hairpins.
- Position patient semiprone or erect with affected side against IR.
- Image both sides for comparison; the side nearest the IR is shown best.
- Align mid-sagittal plane parallel to IR; interpupillary line perpendicular.
- IOML (infraorbitomeatal line) perpendicular to the front edge of the IR.
- Suspend respiration during exposure.
Position & centering point
1/2 inch inferior to the nasion (Bontrager), or 1 inch distal to it (Merrill's), over the nasal bones. Mid-sagittal plane parallel to IR.
Central ray
Perpendicular to IR (horizontal when the patient is erect). Centered 1/2 inch inferior to the nasion (Bontrager). Merrill's uses 1 inch distal to the nasion.
Exposure / technique
- kVp
- 70
- mAs
- DR 2.5 / CR 5
- SID
- 40" (102 cm)
- Notes
- Nongrid (Bontrager). Merrill's chart uses a small focal spot and no grid for this row. Sample technique: DR 2.5 / CR 5 mAs at 70 kVp, 40 in SID, for a 6 cm part. Adjust for your equipment.
kVp and mAs are sample values. Use caution when applying them in your department.
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.
- Frontonasal suture and anterior nasal spine shown.
- Both sides examined for comparison, with the side nearest the IR shown best.
- Soft tissue nasal structures shown with the nasal bones.
Common errors
- 1 Rotation: nasal bones not shown in a true lateral.
- 2 Using a grid or AEC: Bontrager lists this view as nongrid, no AEC.
Clinical indications
- Nasal bone fracture evaluation.
- Trauma to nasal dorsum assessment.