Preoperative diffusion-weighted imaging value of rectal cancer: preoperative T staging and correlations with histological T stage.

PURPOSE:To assess the ability of diffusion-weighted imaging (DWI) for evaluating T stage and correlation with histological T stage of rectal cancer. METHOD:The diagnostic accuracy, sensitivity, and specificity of T2WI and DWI combined with T2WI for T stage were evaluated. Mean tumor apparent diffusion coefficient (ADC) was compared with histological T stage. RESULT:There were no significant differences in the diagnostic accuracy, sensitivity, and specificity no matter what kind of T stage was concerned. The difference between ADC values and histological T stage were significantly different. CONCLUSION:DWI was useful for evaluating T stage of rectal cancer. The ADC may predict the histological grade.