A PNS MRI scan is magnetic resonance imaging of the paranasal sinuses and nearby structures. It gives high‑resolution soft‑tissue images to assess sinusitis, polyps, tumours, orbital or skull‑base involvement, and complications or intracranial extension. MRI is superior to CT for soft‑tissue detail; gadolinium contrast may be used. Preparation includes removing metal and informing staff about pregnancy or renal impairment; it takes about 20–40 minutes.

PNS in MRI refers to peripheral nerve stimulation from time-varying gradient magnetic fields. Rapid gradient switching can induce electric fields that produce tingling, muscle twitching, or mild discomfort. Risk depends on gradient amplitude, slew rate, coil design and patient sensitivity. Safety standards set limits and scanners use pulse adjustments, slower gradient switching and monitoring to minimize PNS and ensure patient comfort.

A PNS scan images the paranasal sinuses to assess sinus infections, inflammation, fluid levels, mucosal thickening, polyps, blockages and fractures. It's used to diagnose and monitor sinusitis, guide treatment or surgery, and detect trauma or suspected foreign bodies. While a plain PNS X‑ray shows general changes, CT provides more detailed anatomy when surgical planning or complex disease is needed.

Abnormal PNS (paranasal sinus) MRI findings are commonly caused by acute or chronic sinusitis (viral or bacterial), allergic rhinitis with mucosal swelling, nasal polyps, mucoceles, and fungal infections. Less commonly, prior surgery or scarring, dental infections, trauma, and benign or malignant tumors can produce opacification or bone changes. Clinical history, endoscopy, and CT help differentiate causes.

The peripheral nervous system (PNS) links the central nervous system to limbs and organs, carrying sensory input to the brain and spinal cord and delivering motor commands to muscles and glands. It enables voluntary movement, reflexes, and vital autonomic functions such as heart rate, digestion, and breathing. Proper PNS function is essential for sensation, coordinated action, and maintaining internal balance and responsiveness to the environment.

A PNS (paranasal sinus) CT scan is generally painless. You lie on a table while the scanner rotates; there’s no cutting or prolonged discomfort. If intravenous contrast is used you may feel a brief warm or metallic sensation and mild arm discomfort from the injection. Claustrophobia or staying still can be uncomfortable for some. Serious pain or complications are rare.