CT Sinus (Limited or Complete) — Dictation, Appropriateness, and Dose for Residents

1. The Pre-FESS Read: Nailing the CT Sinus Report

It’s a busy outpatient list. Next up is a non-contrast CT of the paranasal sinuses for pre-operative planning. The ENT surgeon is expecting a detailed road map for a Functional Endoscopic Sinus Surgery (FESS), and your attending wants every critical anatomic variant and potential surgical pitfall explicitly mentioned. You need to evaluate the ostiomeatal complex, hunt for Onodi and Haller cells, check the lamina papyracea for dehiscence, and apply the Lund-Mackay score. Missing one of these can have real consequences in the OR.

When I was a fellow, these were the reads where I’d pull up a separate browser window with diagrams of the uncinate process just to be sure. It’s a high-stakes anatomy quiz every time. The goal is to create a report that’s not just a description of mucosal thickening, but a clinically actionable guide for the surgeon. For more tools to help you through residency, check out our free trainee calculators and references.

2. What a CT Sinus Exam Covers and What Attendings Look For

A CT of the paranasal sinuses, whether limited or complete, is the gold standard for evaluating the bony anatomy and inflammatory disease of the sinonasal cavities. It’s the definitive study for chronic sinusitis and the essential first step before any FESS procedure. Your attending isn’t just looking for a general impression of “sinusitis”; they expect a systematic evaluation that answers specific clinical questions.

This study is designed to clearly delineate:

• The extent of mucosal thickening and sinus opacification, systematically graded using the Lund-Mackay scoring system.
• The presence and character of sinonasal polyposis.
• Key anatomic variants that could complicate surgery, such as an Onodi cell threatening the optic nerve or a Haller cell narrowing the maxillary ostium.
• Evidence of bony destruction, which could suggest a chronic aggressive infection, an invasive fungal process, or a neoplasm.
• Potential complications of sinusitis, like mucocele formation, orbital cellulitis, or intracranial extension.

Ultimately, your report serves as a surgical roadmap. The surgeon relies on your detailed description of the ostiomeatal complex, the position of the uncinate process, and the integrity of structures like the cribriform plate to plan their approach and avoid complications.

3. Radiology Report Template for CT Sinus (Limited or Complete)

This template provides a solid framework for a comprehensive pre-FESS or chronic sinusitis evaluation. It’s structured to ensure you hit all the key points your attending and the referring ENT surgeon need to see.

Technique

Non-contrast high-resolution computed tomography of the paranasal sinuses was performed with axial acquisition and subsequent coronal and sagittal reformations. Sub-millimeter slices were obtained with a bone algorithm.

Findings

Paranasal Sinuses:
Maxillary Sinuses: [Describe mucosal thickening, air-fluid levels, or opacification. Note any retention cysts or polyps.]
Ethmoid Air Cells: [Describe anterior and posterior ethmoid opacification.]
Sphenoid Sinuses: [Describe opacification. Note relationship to optic canals and any Onodi cells.]
Frontal Sinuses: [Describe opacification and patency of the frontal recess.]

Ostiomeatal Complex (OMC):
Right OMC: [Patent/Obstructed. Describe position of the uncinate process, size of the ethmoid bulla, and patency of the infundibulum.]
Left OMC: [Patent/Obstructed. Describe position of the uncinate process, size of the ethmoid bulla, and patency of the infundibulum.]

Nasal Cavity and Anatomic Variants:
Nasal Septum: [Midline/Deviated to the right/left. Note any septal spur.]
Turbinates: [Note any concha bullosa (pneumatized middle turbinate) or paradoxical middle turbinate.]
Anatomic Variants: [Comment on presence of Haller cells (infraorbital ethmoid cells) or Onodi cells (sphenoethmoidal cells).]

Bony Structures:
[Comment on the integrity of the lamina papyracea, cribriform plate, and fovea ethmoidalis. Note any bony destruction or remodeling to suggest chronic inflammation, mucocele, or neoplasm.]

Incidental Findings:
[Orbits, intracranial structures, and soft tissues of the face are partially visualized and grossly unremarkable. Or describe findings.]

Impression

1. Findings consistent with [mild/moderate/severe] chronic rhinosinusitis. Lund-Mackay score is [X] out of 24.
2. [Right/Left/Bilateral] ostiomeatal complex obstruction.
3. Anatomic variants relevant to surgical planning include [e.g., left-sided concha bullosa, deviated nasal septum to the right, bilateral Haller cells].
4. [No evidence of bony destruction to suggest aggressive or neoplastic process.]

4. Where to Find More Free Radiology Templates

Building a personal library of high-quality templates is a rite of passage in residency. While you’ll create your own macros over time, starting with established, peer-reviewed templates is a smart move. Two great free repositories exist that are worth bookmarking:

• RadReport.org: Curated by the Radiological Society of North America (RSNA), this is one of the most comprehensive and widely used libraries. It covers nearly every modality and subspecialty.
• Radiology Templates (AU): This excellent resource is maintained by Australian radiologists and offers a clean, easy-to-navigate collection of templates for a wide range of common studies.

5. The Next-Level Move: From Free-Form Dictation to Structured Report

The challenge with templates isn’t finding them; it’s using them efficiently under pressure. Tabbing through fields in your dictation system while trying to describe complex findings can break your concentration. The ideal workflow is to dictate your findings naturally, as if you were presenting the case to your attending, and have the software handle the structuring for you.

This is the core idea behind GigHz Precision AI. You can dictate positive findings in free form—”Extensive mucosal thickening throughout the maxillary and ethmoid sinuses with a large concha bullosa on the left and a deviated septum”—and the AI engine organizes those findings into a clean, structured report. It uses pre-loaded templates from governing bodies like the ACR and automatically calculates scores like the Lund-Mackay, ensuring your final report is comprehensive and ready for sign-off.

6. When Should You Order a CT Sinus? ACR Appropriateness Criteria

The American College of Radiology (ACR) provides evidence-based guidelines on when imaging is indicated. For sinonasal disease, the recommendations are quite specific and help guide clinicians to the right test for the right reason.

For a patient with acute (less than 4 weeks) uncomplicated rhinosinusitis, imaging is Usually Not Appropriate. This is a clinical diagnosis. However, the moment you suspect a complication, the calculus changes. For acute rhinosinusitis with suspected orbital or intracranial complication, a CT of the sinuses (often with contrast) is Usually Appropriate to look for abscesses or cellulitis.

The most common indication is for patients with chronic rhinosinusitis (>12 weeks), recurrent acute sinusitis, or sinonasal polyposis who are being considered for surgery. In this scenario, a non-contrast CT of the sinuses is Usually Appropriate and is considered the first-line imaging test. This also applies to suspected mucoceles or evaluation of a deviated nasal septum.

In more urgent situations, such as acute sinusitis with rapid progression or suspected invasive fungal sinusitis, both CT and MRI are rated as Usually Appropriate to assess for bony erosion and soft tissue invasion. Similarly, for a suspected sinonasal mass, both modalities are considered Usually Appropriate, with MRI often providing better soft-tissue characterization and CT defining the bony involvement. Finally, for a suspected CSF leak, a specialized high-resolution CT or CT cisternogram is Usually Appropriate.

7. How Much Radiation Does a CT Sinus Deliver?

Patients and referring providers are increasingly aware of radiation dose, and being able to contextualize it is a key skill. A standard non-contrast CT of the sinuses delivers an estimated effective dose of 0.6-1.5 mSv. This is a relatively low dose, especially when compared to other common CT studies.

To put this in perspective, this dose is in the same ballpark as the average annual background radiation a person receives from natural sources. Modern dose-reduction techniques, like iterative reconstruction, can lower the dose even further, with some low-dose protocols achieving doses around 0.3 mSv. Another alternative, particularly in the outpatient ENT setting, is Cone-Beam CT (CBCT), which offers significantly lower radiation dose while still providing excellent bony detail for pre-surgical planning.

8. CT Sinus Imaging Protocol — Phases, Contrast, and Reconstructions

The quality of a CT sinus interpretation is highly dependent on the acquisition technique. The protocol is designed to maximize spatial resolution of the bony anatomy using the lowest possible radiation dose. It is almost always performed without intravenous contrast unless there is a specific concern for a mass, abscess, or other complication.

The key is acquiring thin, sub-millimeter slices through the sinuses and then creating high-resolution reformats in all three planes. The coronal reformats are considered the gold standard for FESS planning, as they provide the clearest view of the ostiomeatal complex and the relationship of the sinuses to the orbits and skull base.

Common protocol pitfalls:

• Slice Thickness: Using slices thicker than 1 mm for the primary acquisition can limit the quality of the coronal and sagittal reformats, obscuring small but critical structures.
• Field of View (FOV): An FOV that is too wide includes unnecessary anatomy, potentially increasing dose and reducing resolution. A tight FOV of 15-18 cm focused on the sinuses is ideal.
• Patient Positioning: If the patient’s head is tilted, it can make interpreting the coronal views of the ostiomeatal units challenging. A neutral head position is crucial.

9. The 3-Months-Free Offer for Radiology Residents and Fellows

3+ months free for radiology residents and fellows

Look like a rockstar on your reports — dictate positive findings in free form, and our AI generates a structured report using ACR and SIR templates, with the appropriate clinical decision support firing automatically. This lets you focus on the images, not the clicks. All we ask in return is your feedback so we can keep improving the product for trainees.

To get set up, we just need three items:

1. Your PGY year (e.g., PGY-2, PGY-4)
2. Your training type (radiology residency or specific fellowship)
3. Your training program / hospital name

The signup process is simple. No credit card, no long forms. Just reply to the application with the information above. You can apply for the residents free-access program here and get started.

10. Frequently Asked Questions

Is GigHz Precision AI HIPAA-compliant?

Yes. The platform is designed for de-identified workflows by default. No patient-identifying information is required or stored, ensuring compliance with HIPAA privacy and security standards.

Do I need my hospital’s IT department to set this up?

No. GigHz Precision AI is a secure, browser-based application. There is no software to install. It works on any computer, including the PACS workstation in the reading room or your personal laptop or iPad at home.

Does this replace PowerScribe or my hospital’s dictation system?

No, it works alongside it. Most residents dictate into the GigHz web app, let the AI structure the report, and then copy-paste the final, clean text into their official PACS or EMR dictation window for sign-off.

Can I use it on my phone or iPad on call?

Yes. The platform is fully responsive and works well on mobile devices and tablets, making it a useful tool for reviewing findings and drafting reports while on call or away from a dedicated workstation.

Can I customize the templates?

Yes. While the system comes pre-loaded with ACR and other society-endorsed templates, you can create, modify, and save your own templates to match your personal style or your institution’s specific requirements.

What happens after my residency or fellowship ends?

After the free access period for trainees, you have the option to transition to a paid plan for practicing radiologists. There is no automatic enrollment or obligation.