Magnetic resonance imaging of the nasopharynx and skull base.

Ten patients with a normal nasopharynx and 36 patients with pathology of the nasopharynx or skull base were studied with magnetic resonance imaging (MRI). Four millimeter thick axial, coronal, and often sagittal scans were obtained using SE 500/28 and SE 2000/56 pulse sequences. The normal scans were compared with cadaver cryosections. Correlation was made with computed tomography (CT) scans as well as with clinical history and physical examination whenever possible. MRI clearly provided superior information compared with CT and other imaging studies. Advantages of MRI over CT include 1) the delineation of tumor infiltrations of the longus colli muscles, rectus capitus muscles, and muscles of mastication, 2) demonstration of tumor extensions into the skull base or parapharyngeal spaces, and 3) demonstration of both normal and pathologic cranial nerves. For all these reasons, MRI is currently the imaging study of choice for pathology of the nasopharynx and skull base.