Magnetic resonance imaging (MRI) in the diagnosis of head and neck disease.

Magnetic resonance imaging (MRI) is the modality of choice to identify intracranial or perineural spread from a head and neck primary tumor. Perineural spread is a form of metastatic disease in which primary tumors spread along neural pathways. Orbital cellulitis is a sight-threatening, and potentially life-threatening condition. Urgent imaging is performed to assess the anatomic extent of disease, including postseptal, cavernous sinus, and intracranial involvement, and identify orbital abscesses that require exploration and drainage. MRI is useful in the evaluation of the brachial plexus.