Preoperative apparent diffusion coefficient value of gastric cancer by diffusion‐weighted imaging: Correlations with postoperative TNM staging

BACKGROUND: To determine if the apparent diffusion coefficient (ADC) values of gastric cancers on the preoperative diffusion weighted imaging (DWI) correlate with the postoperative TNMs of the lesions. METHODS: In a retrospective clinical study, seventy patients with gastric cancers were enrolled and each underwent a MRI before surgery. DWI was obtained with a single-shot, echo-planar imaging sequence in the axial plane (b values: 0 and 1000 s/mm(2) ). The mean and minimum ADC values of the gastric cancers were calculated and compared among various postoperative TNM staging. RESULTS: Both mean and minimum ADC values of the gastric cancers correlated with the postoperative T staging (r = -0.464, -0.476; both P < 0.001), N staging (r = -0.402, -0.397; P = 0.001, 0.002) and TNM staging (r = -0.446, -0.437; both P < 0.001). The areas under the receiver operating characteristic (ROC) curves for the differentiating lymph node metastasis were 0.788 for the mean ADC values (P = 0.001) and 0.778 for the minimum ADC values (P = 0.001). CONCLUSION: The preoperative ADC values of gastric cancers can help to assess the postoperative TNM staging.