III. Advantages

  1. Much more sensitive than Sinus XRay
  2. Good Sinus Anatomy definition
    1. Views sphenoid and Ethmoid Sinuses well
    2. Defines osteomeatal complex well

IV. Indications

  1. Confusing presentation
  2. Evaluation before endoscopic surgery
  3. Sinusitis refractory to maximal medical management
    1. Recurrent Acute Sinusitis
    2. Persistent Chronic Sinusitis Symptoms
    3. Suspected Osteomeatal complex Occlusion
    4. Suspected Allergic Fungal Sinusitis
    5. Suspected Fungal Sinusitis or other complicated Sinusitis (e.g. immunocompromised patients)
    6. Sinusitis complications (e.g. Cavernous Sinus Thrombosis)

V. Technique

  1. Full Coronal non-contrast Sinus CT
    1. Standard view indicated in most cases
    2. Mucosal thickening >5mm is consistent with sinus infection
    3. Demonstrates fluid and mucosal edema, as well as bony destruction
    4. Fat stranding (increased density) may be present in para-sinus spaces
  2. Limited Sinus CT
    1. Consider as alternative to full Sinus CT
    2. Four non-contiguous 5 mm slices in coronal plane
      1. Frontal Sinus
      2. Anterior ethmoid and Maxillary Sinuses
      3. Posterior ethmoid and Maxillary Sinuses
      4. Sphenoid Sinus
    3. Advantages
      1. Less expensive
      2. Less radiation
    4. Disadvantage
      1. Unknown efficacy
  3. Contrast Sinus CT
    1. Indications
      1. Periorbital Cellulitis or abscess
      2. Vascular complications
      3. Cavernous Sinus Thrombosis
    2. Findings
      1. Necrotic tissue and fluid does not contrast enhance
      2. Inflamed, thickened mucosa contrast enhances
        1. Mucosa, fluid and soft tissue may be indistinguishable without contrast
      3. Consider IV contrast in complicated cases (e.g. vascular complications, Cavernous Sinus Thrombosis)

VI. Timing

  1. Perform during maximal medical therapy
  2. Delay if URI present

VII. Contraindications: Relative

  1. Submaximal medical Management
  2. Upper Respiratory Infection
  3. Acute sinus infection

VIII. Interpretation

  1. Findings consistent with Rhinosinusitis
    1. Air-fluid levels
    2. Total opacification
    3. Mucosal thickening >5 mm
  2. Complications identified by Sinus CT
    1. Osteomeatal Complex Obstruction
    2. Allergic Fungal Sinusitis

IX. References

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Related Studies

Ontology: CT of paranasal sinuses (C0412593)

Concepts Diagnostic Procedure (T060)
ICD10 56022-01
SnomedCT 241526005
English CT of paranasal sinuses (procedure), Computed tomography of paranasal sinuses (procedure), Computed tomography of paranasal sinuses, paranasal CT scan, computed tomography of paranasal sinuses, computed tomography of paranasal sinuses (procedure), CT scan of paranasal sinuses, Computerised tomography of paranasal sinus, Computerized tomography of paranasal sinus, CT of paranasal sinuses
Spanish TC de senos paranasales, tomografía computarizada de senos paranasales (procedimiento), tomografía computarizada de senos paranasales

Ontology: Computed tomography of sinuses (C1960838)

Concepts Diagnostic Procedure (T060)
SnomedCT 425916005
English Computed tomography of sinuses (procedure), Computed tomography of sinuses
Spanish TC sinusal, tomografía computarizada sinusal, tomografía computarizada sinusal (procedimiento)