MRI of the floor of the mouth, tongue and orohypopharynx.

Magnetic resonance is the imaging modality of choice for studies of the orohypopharynx, floor of the mouth, or tongue base. The superiority of MRI soft tissue contrast can demonstrate intra- and extraorgan spread of tumor beyond that of CT. Use of T1- and T2-weighted pulse sequences allows better discrimination of pathologic masses from fat or muscle than does CT. Multiplanar capabilities allow ease of examination in the preferred planes. Various sequences or planes of imaging may be chosen to tailor the examination to the anatomic region of interest. The use of Gd-DTPA with T1-weighted images should further improve diagnostic precision of tumor location and extension and may replace the need for the longer T2-weighted sequences. Gadolinium may help differentiate tumor recurrence from fibrosis in the post-radiation patient. New improvements in surface coil technology, motion and flow compensation imaging strategies, faster scan times, and spatial resolution will further advance MRI as the modality of choice for assessment of oropharyngeal, mouth, and tongue soft tissue masses.