A PNS MRI scan is a magnetic resonance imaging study focused on the paranasal sinuses and nearby structures. It produces detailed cross‑sectional images of the sinuses, nasal cavity, orbits and skull base to evaluate sinusitis, polyps, tumors, bone or soft‑tissue complications and for preoperative planning. It is noninvasive, uses no ionizing radiation, may use contrast for clearer soft‑tissue detail, and takes about 15–45 minutes.

Gadolinium-based contrast agents are used for most MRI contrast studies. Gadolinium is a paramagnetic metal given intravenously in chelated form to reduce toxicity; it enhances vascular structures, inflammation, tumors, and breakdowns in the blood–brain barrier. Side effects are uncommon but can include allergic reactions and, rarely, nephrogenic systemic fibrosis in people with severe kidney impairment, so kidney function is usually checked beforehand.

A PNS scan is an imaging test of the paranasal sinuses (air‑filled cavities around the nose). It can be a plain X‑ray or, more commonly, a CT scan used to detect sinusitis, fluid levels, polyps, mucosal thickening, and facial bone fractures. The procedure is quick and noninvasive, uses ionizing radiation, and is ordered when symptoms are persistent, severe, or complications are suspected.

Contrast dye used in MRI is gadolinium-based and may cause mild, short-lived effects: headache, nausea, dizziness, warmth at the injection site, taste changes, itching, hives or rash. Rarely it triggers serious allergic reactions, breathing difficulties or low blood pressure. In people with severe kidney disease it can rarely cause nephrogenic systemic fibrosis; trace gadolinium retention has been reported after repeated doses.

The peripheral nervous system (PNS) is the part of the nervous system outside the brain and spinal cord. It comprises cranial and spinal nerves, ganglia, and sensory receptors that connect the central nervous system to limbs and organs. The PNS includes somatic (voluntary) and autonomic (involuntary — sympathetic and parasympathetic) divisions, relaying sensory input to the brain and motor commands to tissues.

A PNS (paranasal sinuses) CT scan is generally painless and noninvasive. You lie still while the scanner takes images; you may feel mild discomfort from staying in one position, claustrophobia, or machine noise. If contrast dye is used, you might notice a brief sting or warmth; allergic reactions are uncommon. The scan itself does not cause pain, though existing sinus tenderness may persist.