From the Guidelines
When reading the frontal sinus on a CT scan, use a systematic approach that includes examining both axial and coronal views for comprehensive evaluation, as recommended by the most recent guidelines 1. Begin by identifying the frontal sinus above the orbit and assess its pneumatization pattern, which varies significantly between individuals. Look for the frontal sinus drainage pathway (frontal recess), noting its patency and any obstruction. Evaluate the mucosal lining for abnormal thickening (>3mm suggests inflammation), air-fluid levels, or complete opacification. Check for bony integrity of the sinus walls, looking for dehiscence, erosion, or fractures, particularly along the posterior wall adjacent to the anterior cranial fossa. Compare the right and left frontal sinuses for asymmetry, which may indicate pathology. This systematic approach is important because frontal sinus pathology can lead to serious complications due to its proximity to the brain, and subtle findings might indicate frontal sinusitis, mucoceles, or other conditions requiring intervention, as highlighted in recent studies 1. The frontal sinus is often the most challenging paranasal sinus to evaluate due to its variable anatomy and complex drainage pathway, so careful attention to these details ensures accurate interpretation, and CT scans are considered the best imaging modality for this purpose, providing detailed depiction of bony anatomy and essential information for surgical planning 1.
Some key points to consider when evaluating the frontal sinus on a CT scan include:
- The importance of using both axial and coronal views to fully assess the sinus and its drainage pathway
- The need to evaluate the mucosal lining and bony integrity of the sinus walls
- The potential for serious complications if frontal sinus pathology is not accurately diagnosed and treated
- The value of CT scans in providing detailed information for surgical planning and intervention, as noted in recent guidelines 1.
Overall, a systematic and thorough approach to reading the frontal sinus on a CT scan is essential for accurate diagnosis and effective treatment of frontal sinus pathology, and this approach should be guided by the most recent and highest-quality evidence available 1.
From the Research
Approach to Reading the Frontal Sinus on a CT Scan
- The approach to reading the frontal sinus on a computed tomography (CT) scan involves evaluating the extent of sinus opacification, opacification of sinus drainage pathways, anatomical variants, critical variants, and the condition of surrounding soft tissues 2.
- A systematic approach to the use of coronal, axial, and sagittal images in CT evaluation is essential for accurate assessment of the frontal sinus 2.
- The radiologist's goal is to report on key points, including the extent of sinus opacification and anatomical variants, to provide a roadmap for functional endoscopic sinus surgery (FESS) 2.
- Computed tomography (CT) scans of the paranasal sinuses, including the frontal sinus, are mandatory for preoperative evaluation before FESS 2.
- The use of CT scans can help identify complications of rhinosinusitis, such as orbital cellulitis, meningitis, and abscess, and can guide referral to an otolaryngologist 3.
Key Points to Evaluate
- Extent of sinus opacification
- Opacification of sinus drainage pathways
- Anatomical variants
- Critical variants
- Condition of surrounding soft tissues, including the brain and orbits 2