What is the recommended initial imaging study, CT (Computed Tomography) sinus with or without contrast, for facial pain suspected to be related to sinusitis?

CT Sinus Without Contrast is the Recommended Initial Imaging Study for Facial Pain Suspected to be Related to Sinusitis

CT maxillofacial without IV contrast is the recommended initial imaging study for evaluating facial pain suspected to be related to sinusitis. 1, 2

Rationale for Non-Contrast CT

• Non-contrast CT is considered the gold standard for routine sinus evaluation, providing:

  • Accurate depiction of sinus anatomy and soft-tissue changes
  • Detailed visualization of the osteomeatal complex
  • Ability to perform multiplanar reconstruction (axial, coronal, sagittal)
  • Surgical planning information if intervention becomes necessary 1, 2

• The American College of Radiology (ACR) Appropriateness Criteria specifically recommends CT maxillofacial without IV contrast for patients with:

  • Acute recurrent sinusitis
  • Chronic rhinosinusitis
  • Sinonasal polyposis
  • Facial pressure/pain unresponsive to medical therapy 1

When Contrast Should Be Considered

Contrast-enhanced CT should be reserved for specific clinical scenarios:

1. Suspected complications including:

   • Orbital complications (cellulitis, abscess)
   • Intracranial extension
   • Cavernous sinus thrombosis 1, 2

2. Suspected invasive fungal sinusitis, particularly in:

   • Immunocompromised patients
   • Patients with hematological malignancies 1

3. Suspected sinonasal mass or neoplasm 1

Important Clinical Considerations

• Imaging is not recommended for uncomplicated acute rhinosinusitis, as diagnosis should be made on clinical grounds 2, 3

• Plain radiographs have poor sensitivity and specificity (25-41% for most sinus groups) and are no longer recommended for sinus imaging 2, 3

• Performing both non-contrast and contrast CT doubles radiation exposure without significant additional diagnostic yield 1, 2

• MRI is not first-line for routine sinusitis evaluation but may be valuable in specific scenarios:

  • Better differentiation of mucosal thickening from secretions
  • Detection of intracranial complications
  • Suspected fungal sinusitis
  • Differentiating inflammatory disease from tumors 1, 2

Common Pitfalls to Avoid

• Ordering imaging for uncomplicated acute sinusitis when diagnosis can be made clinically 2, 4

• Misinterpreting incidental radiographic findings as bacterial sinusitis when they may represent viral infection or normal variants 2, 5

• Performing imaging too soon after treatment (less than 4 weeks after acute bacterial sinusitis) 2

• Using contrast when not indicated, unnecessarily increasing radiation exposure 1, 2

• Failing to use contrast when complications are suspected, potentially missing important findings 1, 2

In summary, CT maxillofacial without IV contrast should be the initial imaging study for evaluating facial pain suspected to be related to sinusitis, with contrast-enhanced studies reserved for cases with suspected complications or specific clinical scenarios requiring enhanced tissue characterization.