OBJECTIVETo evaluate the clinical value of diffusion-weighted imaging (DWI) with 3.0 T magnetic resonance scanner for nasopharyngeal carcinoma (NPC) and to explore the appropriate b value during this procedure.

METHODSTotally 50 patients with histopathologically confirmed NPC and 20 volunteers underwent DWI using single-shot echo-planar imaging technique were enrolled in this study. Four groups of b value (600, 800, 1000 and 1200) were applied. The apparent diffusion coefficients (ADC) between the primary tumor of NPC and the metastatic lymph nodes were compared in each group. ADC between the metastatic lymph nodes and benign nodes were also compared.

RESULTSAlthough the mean ADC were not significantly different between NPC and those of metastatic cervical lymph nodes in each group, the mean ADC of the metastatic lymph nodes were significantly lower than those of benign nodes (P<0.05). When b value was 800, both satisfying images and accurate measurements were acquired.

CONCLUSIONDWI is helpful in the diagnosis of primary lesions and their lymph node metastases of NPC.