ABSTRACT
Background and purpose:Gastric cancer impacts human health seriously. Accurate preoperative assessment of T staging and metastatic lymph nodes of gastric cancer was beneifcial to patients’ treatment options and their prognosis. The purpose of this study was to evaluate the diagnostic performance of diffusion-weighted magnetic resonance imaging for preoperative assessment of T staging and metastatic lymph nodes in patients with gastric cancer. Methods:This study selected 35 gastric cancer patients met the criteria for this prospective study. They all underwent gastric 3.0 T MRI+DWI imaging scan. These patients’ T stage and metastatic lymph nodes were evaluated before the surgery, with the reference of post-operative histopathological ifndings. Kappa consistency test was used to assess the consistency of T staging between the two methods. This study analyzed short axis diameter, long axis diameter and apparent diffusion coeffcient (ADC) values of lymph nodes, relative of muscle’s ADC (rADCm) values (rADCm=ADC values of lymph nodes/ADC values of right erector spinae), and relative of primary tumor’s ADC (rADCp) values (rADCp=ADC values of lymph nodes/ADC values of primary tumor) on MRI image. Independent samples test was used to assess the difference between metastatic lymph nodes and benign lymph nodes. The receiver operating characteristic(ROC) curve was generated to evaluate the accuracy of diffusion-weighted magnetic resonance imaging (MRI) for preoperative assessment of metastatic lymph nodes of gastric cancer.Results:The accuracy of diffusion-weighted MRI for T stages was 77.14%, 75% for T1, 100% for T2, 76.47% for T3 and 75.00% for T4 and respectively. There were statistically signiifcant differences in the long axis diameter, the short axis diameter, ADC value, rADCm and rADCp between metastatic lymph nodes and benign lymph nodes (P<0.05). The area under the ROC curve of rADCm was greater than thats of other criteria, so rADCm was the most signiifcant parameter. The best discriminative cut-off value of long axis, short axis, ADC value, rADCm value and rADCp value were 9.55 mm, 6.05 mm, 0.934×10-3mm2/s, 0.60 and 1.083, respectively. The sensitivity and speciifcity were 59.00% and 73.10%, 59.00% and 69.80%, 82.60% and 88.50%, 83.70% and 84.60%, 78.20% and 80.80%, respectively.Conclusion:Diffusion-weighted MRI has great signiifcance for preoperative assessment of T staging and metastatic lymph nodes of gastric cancer.