RadteraCT Paranasal Sinuses (Non-Contrast)
CTNo contrastHead & Neck
Indications
- Chronic or recurrent sinusitis
- Pre-operative mapping prior to functional endoscopic sinus surgery (FESS)
- Evaluation of sinonasal anatomic variants (e.g. concha bullosa, Haller cell, Onodi cell)
- Suspected sinonasal obstruction, polyposis, mucocele
- Surgical navigation/stealth dataset
Patient prep
- No NPO or contrast for routine sinusitis study
- Remove dentures, earrings, glasses, hairpins
- Supine head-first; for surgical navigation acquire per navigation system fiducial protocol
Contrast
None / non-contrast
Technique
- Supine, head first; acquire thin-section helical volume covering frontal sinus through hard palate/maxillary teeth
- Low-dose technique appropriate (bone detail high inherent contrast): 100-120 kV, low mAs with AEC
- Reconstruct thin (0.5-0.75 mm) bone/sharp kernel and reformat coronal and sagittal
- Coronal plane is primary for FESS mapping (relationship of uncinate, ostiomeatal complex, cribriform plate/fovea ethmoidalis)
- No breath-hold needed; quiet breathing
Series / Sequences
| # | Series / Sequence | Plane | Thickness | Notes |
|---|---|---|---|---|
| 1 | Axial bone | axial | 0.5-0.75 mm | Sharp/bone kernel; source for reformats |
| 2 | Coronal reformat (bone) | coronal | 1-2 mm | Primary plane for ostiomeatal complex and FESS planning |
| 3 | Sagittal reformat (bone) | sagittal | 1-2 mm | Frontal recess/sphenoethmoidal recess |
| 4 | Axial/coronal soft tissue (optional) | axial | 2-3 mm | Soft-tissue window if mass/complication suspected |
Key points
- Low-dose non-contrast bone technique is standard; sinusitis does not require IV contrast
- Coronal reformats are key for FESS; report keros classification (olfactory fossa depth), cribriform plate asymmetry, optic nerve/ICA dehiscence near sphenoid, Onodi/Haller cells
- Add IV contrast and soft-tissue series if invasive fungal sinusitis, abscess, orbital/intracranial complication, or neoplasm is suspected
- Note any prior surgical changes for revision FESS
References
• ACR–ASNR–SPR Practice Parameter for the Performance of CT of the Extracranial Head and Neck
• ACR Appropriateness Criteria: Sinonasal Disease
• Radiopaedia: CT paranasal sinuses (protocol) link
• RadioGraphics: Imaging of the Paranasal Sinuses for FESS
• ACR Appropriateness Criteria: Sinonasal Disease
• Radiopaedia: CT paranasal sinuses (protocol) link
• RadioGraphics: Imaging of the Paranasal Sinuses for FESS
Source: Researched — verify against your institution
Reference template — verify and adapt to your scanner, vendor and institution before clinical use. Not a substitute for clinical judgment.