Dynamic magnetic resonance imaging (MRI) has been used to improve the detection of tumors, to determine the tumor extension, and to make differential diagnosis. Most malignant lesions of the head and neck show early enhancement and early washout of contrast media on dynamic MRI, but the tumor characterization remains unclear. Pharmacokinetic analysis of dynamic MRI can provide information about the permeability of Gd-DTPA in the tumor that may reflect the oxygen concentration of the tumor and the amount of drug delivered to the tumor. This information may be useful in the prediction of radiation and/or chemotherapy response of the tumor.