Recommended Radiographic Views for Sinus Imaging
CT scanning without contrast is the gold standard for routine sinus imaging, while plain radiographs are generally not recommended due to their limited sensitivity and specificity, particularly for ethmoid disease. 1, 2
Plain Radiography (When CT is Unavailable)
When CT is unavailable and plain radiographs must be used, the following views are recommended:
Waters view (occipito-mental): The single most useful view for evaluating maxillary sinuses 1
Caldwell view (anterior-posterior): Best demonstrates frontal sinuses 1
- Limited utility for ethmoid visualization due to structural superimposition
Lateral view: Visualizes sphenoid sinus and adenoids in children 1
Limitations of Plain Radiography
- Poor sensitivity for ethmoid disease (51.8%) 3
- Limited visualization of fine bony anatomy and ostiomeatal complex 1
- High false-positive rates (32% for maxillary sinuses, higher for other sinuses) 1
- Poor correlation between radiographic findings and actual disease requiring treatment 1
- Cannot adequately evaluate chronic sinusitis or provide surgical planning information 1
Modern Imaging Recommendations
Non-contrast CT: Gold standard for routine sinus evaluation 1, 2
- Provides accurate depiction of sinus anatomy and soft-tissue changes
- Allows multiplanar reconstruction (axial, coronal, sagittal)
- Essential for surgical planning
- Low-dose protocols now have radiation exposure similar to conventional radiographs 2
Contrast-enhanced CT: Indicated when complications are suspected 1, 2
- Orbital or intracranial complications
- Immunocompromised patients (especially for invasive fungal sinusitis)
MRI: Not first-line for routine sinusitis but valuable for specific scenarios 1, 2
- Better differentiates mucosal thickening from secretions
- Superior for detecting intracranial complications
- Recommended for suspected fungal sinusitis or to differentiate inflammatory disease from tumors
Common Pitfalls to Avoid
- Relying solely on plain radiographs for ethmoid disease evaluation 1, 3, 4
- Using ultrasonography as primary diagnostic tool (poor sensitivity/specificity) 1
- Performing imaging for uncomplicated acute sinusitis (diagnosis should be clinical) 1
- Failing to use contrast when evaluating for complications 2
- Misinterpreting normal mucosal thickening as pathologic 2
Special Considerations
- For pregnant women: Ultrasonography may be considered for maxillary and frontal sinuses to avoid radiation exposure 1
- For children: CT with lower radiation dose is preferred; plain films have even lower diagnostic value in pediatric populations 4
- For preoperative evaluation: CT is essential as it provides a "road map" for surgery 1
In summary, while the Waters view alone may be sufficient for basic maxillary sinus evaluation 5, modern practice strongly favors CT as the primary imaging modality for comprehensive sinus evaluation due to its superior diagnostic accuracy and ability to visualize all paranasal sinuses and critical anatomical structures.