Magnetic resonance imaging of head and neck tumors.

Magnetic resonance imaging (MRI) provides several advantages over computed tomography (CT) in the evaluation of head and neck region tumors. The improved soft-tissue contrast among normal and abnormal tissues provided by MRI now permits the exact delineation of tumor margins in the nasopharynx, oropharynx, and skull base regions. In addition, the ability to depict cross-sectional anatomy and pathology in three planes without intravenous contrast, patient manipulation, or ionizing irradiation is a distinct advantage of MRI over CT scanning. Drawbacks of MRI include the detection of subtle osseous abnormalities, patient motion, and artifacts introduced by ferromagnetic dental appliances. These drawbacks appear minimal when compared to the benefits of improved soft-tissue contrast and the ability to image exact tumor volumes.