PNS in a CT scan stands for paranasal sinuses. A PNS CT is a non‑contrast computed tomography study that images the air-filled sinus cavities to evaluate sinusitis, polyps, anatomical variants, fractures, or tumors. It shows mucosal thickening, air–fluid levels, and bony anatomy, and is commonly used for chronic or recurrent sinus symptoms and preoperative planning due to its high sinus detail.

A CT (computed tomography) scan of the brain and peripheral nervous system uses X‑rays and computer processing to produce detailed cross‑sectional images. It evaluates brain anatomy and acute problems (bleeding, stroke, tumors, fractures) and can assess bony pathways and surrounding tissues affecting peripheral nerves. The test is quick and noninvasive, may use contrast, and involves ionizing radiation with limited resolution for tiny nerve fibers.

Costs vary widely by country and facility. In India a non‑contrast CT PNS typically costs about ₹1,200–₹5,000 in private centres. In countries with public health coverage it may be covered, while private scans often run about £150–£400. In the US out‑of‑pocket prices commonly range from $300–$2,000 depending on hospital, location and whether contrast or specialist interpretation is needed; appointment timing and imaging technology also affect price.

A CT PNS (CT paranasal sinuses) scan itself is very quick—usually 2 to 5 minutes of imaging. Including registration, positioning and brief preparation, the whole appointment typically takes 15 to 30 minutes. No special preparation is generally needed, though children or anxious patients may require extra time. If contrast is used, allow 30–60 minutes; results often arrive within hours to days.

CT of the paranasal sinuses is generally painless and noninvasive. You lie on a table that moves through the scanner; you may feel mild discomfort from lying still, noise, or claustrophobia. Contrast dye is usually not needed for routine PNS CT—if used, the IV can sting briefly or cause warmth. Serious side effects are rare.

CT PNS is designed for sinuses and bone detail and can only incidentally show large masses that extend into the paranasal sinuses or skull base. It is not reliable for detecting intracranial brain tumors. Dedicated brain MRI (with contrast) is the preferred, more sensitive modality for diagnosing and characterizing brain tumors; CT head may be used if MRI is unavailable or contraindicated.