Nasal Bone Lateral View X-Ray: Positioning, Technique & Anatomy

Nasal Bone Lateral View

The Lateral View of the Nasal Bones is a specialized, high-resolution radiographic projection designed specifically to demonstrate the delicate nasal bones, the frontonasal suture, and the surrounding anterior nasal soft tissues in profile.

Because nasal fractures often involve minimal displacement, both Right and Left lateral views are routinely obtained for bilateral comparison, with the side closest to the image receptor (IR) showing the finest spatial sharpness and minimal geometric magnification.

1. Clinical Indications & Contraindications

Detailed Indications:

• Nasal Trauma & Direct Impact:
  • Detection of linear, comminuted, or depressed fractures of the nasal bones.
  • Identification of fracture displacement (anterior, posterior, or “telescoping” impaction).
  • Assessment of associated soft tissue swelling, hematoma, or soft tissue lacerations in profile.
• Frontonasal Suture & Process Disruptions:
  • Diastasis or fracture-dislocation across the frontonasal suture (nasofrontal junction).
  • Fractures involving the frontal process of the maxilla and the anterior nasal spine.
• Foreign Body Localization: Visualization and depth assessment of radiopaque foreign bodies lodged in the anterior nasal cavity or soft tissues.
• Post-Reduction Follow-up: Verification of bony alignment following closed or open reduction of a fractured nasal bridge.

Contraindications & Limitations:

• Unstable Cervical Spine Injury: Standard semi-prone or rotated-head lateral positioning is contraindicated until C-spine clearance is complete. If necessary, a horizontal beam (cross-table) lateral can be performed supine with a direct film-to-face contact approach.
• Nasal Septal Deviation (Inherent Limitation): Lateral radiographs show the nasal bones in superimposition; they cannot reliably evaluate lateral deviation of the nasal septum or medial orbital wall/lamina papyracea blowouts. A Waters (Parietoacanthial) view or high-resolution facial bone CT must accompany the lateral view for complete assessment.

2. Technical Factors & Exposure Physics

Unlike standard skull radiography, the nasal bones are extremely thin, delicate, and surrounded by air. Using standard skull factors will completely burn out (overpenetrate) the nasal bone. A low-kVp, non-grid (tabletop) technique is essential.

Parameter	Recommended Specification	Radiographic Rationale
Grid Usage	Non-Grid (Tabletop)	Air provides natural contrast; a grid is omitted to prevent grid cutoff and preserve fine detail
Image Receptor (IR)	18 × 24 cm (Landscape/Crosswise)	Small format; both R and L sides can be exposed on one cassette with lead masking
SID	100 to 115 cm ( 40 to 44 inches)	Standard focal distance minimizes penumbra
Tube Potential (kVp)	50 – 60 kVp (VeryLow)	High-contrast (photoelectric-dominant) beam prevents burnout of thin bone cortex
mAs Range	3 – 6 mAs (Low Exposure)	Calibrated for low density to visualize both bone trabeculae and soft tissue profile
Focal Spot	Small (0.6 mm)	Crucial for resolving micro-fractures and subtle cortical disruption
Breathing	Suspended respiration	Eliminates respiratory motion blur and soft-tissue twitching

3. Step-by-Step Patient & Part Positioning

• Patient Preparation: Remove eyeglasses, nose piercings/rings, earrings, and metallic hair accessories.
• General Posture Options:
  1. Erect (Seated – Preferred): Patient sits facing the upright table or Bucky, turns the head into a true lateral position with the side of interest resting against the non-grid receptor surface.
  2. Semi-Prone (Tabletop): Patient lies semi-prone on the radiographic table with the affected side down. The ipsilateral arm rests by the side; the contralateral arm and knee are flexed to stabilize the body.
• Alignment of Reference Lines & Planes:
  1. Mid-Sagittal Plane (MSP): Must be strictly parallel to the plane of the image receptor. Ensure the patient is not tipping the chin up or down.
  2. Interpupillary Line (IPL): Must be strictly perpendicular to the plane of the image receptor. Use a radiolucent sponge beneath the chin if needed to maintain this alignment.
  3. Infraorbitomeatal Line (IOML): Must be positioned parallel to the transverse or long axis of the image receptor.

4. Central Ray (CR) & Strict Collimation

• CR Angle: Strictly perpendicular (0⁰) to the image receptor.
• CR Centering Point: Directed to a point 1.25 cm (0.5 inch) inferior to the Nasion (the nasofrontal junction).
• Strict Collimation: Tight four-sided collimation is critical to reduce scatter and protect image contrast:
  • Superiorly: 2cm above the glabella (to include the nasofrontal suture).
  • Inferiorly: To the level of the anterior nasal spine and upper lip.
  • Anteriorly: 2 to 3 cm beyond the anterior soft-tissue tip of the nose.
  • Posteriorly: To the anterior border of the maxilla and anterior lacrimal crest.

5. Radiographic Anatomy & Quality Evaluation Criteria

• No Rotation or Tilt: Confirmed by the precise alignment of the nasal bones without double contouring of the anterior maxilla.
• Structures Visualized in Profile:
  • Nasal bones from their thick superior junction at the frontal bone down to their thin, pointed inferior borders.
  • Frontonasal suture (nasofrontal junction).
  • Frontal process of the maxilla.
  • Anterior nasal spine visualized sharply in profile at the base of the nasal septum.
  • Clear soft-tissue outline of the nasal bridge, cartilaginous dorsum, and nasal tip.
• Optimal Density & Penetration: High-contrast resolution that clearly defines the fine cortical margins and trabeculae of the nasal bone without burning out the anterior soft tissues or under-penetrating the anterior nasal spine.