The nasal cavity and sinuses filter, warm, and humidify the air we breathe. When this system malfunctions, it causes persistent symptoms like chronic congestion, facial pressure, and a reduced sense of smell. Since the source of these issues is hidden deep within the facial bones, direct visualization of the internal anatomy is necessary for an accurate diagnosis. Imaging provides a detailed map of the nasal passages, allowing specialists to pinpoint the exact cause of symptoms that resist initial medical treatment.
The Tools of Visualization
Specialists use three primary methods to generate detailed images of the nasal passages, each offering a distinct view of the internal anatomy. Computed Tomography (CT) scanning is the standard tool for assessing the bony framework and air-filled spaces of the sinuses. The CT scan excels at showing fine bone detail, making it ideal for identifying structural narrowing or damage to the sinus walls. This rapid, cross-sectional imaging clearly distinguishes air, bone, and soft tissue density, providing a high-resolution blueprint for surgical planning.
Magnetic Resonance Imaging (MRI) provides superior contrast for soft tissues, which is useful for differentiating various types of fluid and growths. An MRI can help distinguish between inflammatory mucus, nasal polyps, and potentially more serious soft tissue masses like tumors. While it is slower and more expensive than a CT scan, MRI is often reserved for cases where spread to the brain or eye socket is a concern. Nasal Endoscopy, or rhinoscopy, is a distinct procedure where a thin, lighted tube with a camera is inserted directly into the nose for a real-time visual inspection. This allows the physician to examine the mucosal lining, identify the precise location of drainage, and directly sample tissue if necessary.
Structural Issues and Airflow Obstruction
Imaging methods are highly effective at revealing fixed, anatomical problems that physically block the normal flow of air and mucus drainage. A common finding is a deviated septum, where the thin wall of cartilage and bone separating the nasal passages is misaligned. This misalignment appears sharply curved or shifted on a CT scan and can drastically narrow one side of the nasal cavity, impeding airflow.
Scans frequently show turbinate hypertrophy, which is the enlargement of the shelf-like structures inside the nose that regulate airflow. This enlargement can involve the soft mucosal tissue, the underlying bone, or both, a distinction clearly made by CT imaging. When a severe septal deviation is present, the turbinates on the opposite side may enlarge in a compensatory effort. Fixed structural variants, such as an enlarged middle turbinate containing an air pocket (concha bullosa), can also contribute to chronic obstruction by blocking the narrow drainage pathways of the sinuses.
Identifying Disease and Inflammation
The primary strength of imaging lies in characterizing the pathological conditions that cause chronic symptoms. For sinusitis, CT scans show evidence of mucosal thickening (swelling of the inner lining) and opacification (clouding of normally air-filled sinuses by fluid or thick mucus). Acute sinusitis may present with a distinct air-fluid level visible within the sinus cavity, indicating trapped liquid.
Chronic inflammatory conditions, such as nasal polyps, appear on CT as soft-tissue masses that are hypoattenuating (lower density than bone). These benign, teardrop-shaped growths can completely fill and obstruct the nasal cavity and sinuses, a condition known as sinonasal polyposis. MRI offers supplementary detail by helping to differentiate these polyps and inflammatory secretions from solid masses. Imaging is also the initial step in investigating suspicious growths. An MRI is often used to assess masses for local invasion into surrounding soft tissues, such as the orbit or the base of the skull, assisting in surgical planning.
Understanding Your Results and Next Steps
Once images are acquired, a radiologist generates a comprehensive report detailing the findings, including the extent of inflammatory disease and the location of key anatomical structures. This report often uses a standardized scoring system to quantify the severity of sinus opacification, providing a measurable baseline. The specialist, typically an otolaryngologist, then correlates these findings with the patient’s symptoms and the results of a nasal endoscopy.
This combined assessment determines the appropriate path forward, which may involve medical management or surgical intervention. If imaging reveals mild mucosal thickening without significant structural blockage, initial treatment may involve medication to reduce inflammation. If scans show severe obstruction from a deviated septum or extensive polyps, the images become an indispensable roadmap for functional endoscopic sinus surgery. Follow-up imaging may be ordered months later to monitor treatment effectiveness and confirm the resolution of disease or the patency of newly opened drainage pathways.