Evaluation Of Lymph Nodes In Patients With Gastric Carcinoma Using DWI Value

Objective: The study was to investigate the diagnostic value of diffusion weightedimaging in determine the lymph node metastasis of gastric cancer, and evaluate the valueof ADC and ADC ratio in the differentiation of metastatic lymph nodes fromnon-metastatic lymph nodes in gastric cancer.Materials and Methods Magnetic resonance imaging (MRI) scans before surgeryand clinical data of43pathologically proven gastric carcinoma were retrospectivelyreviewed. Size-based criteria (i.e. short-axis diameter and long-axis diameter), minimumADC values were measured in metastatic and non-metastatic Lymph nodes (LNs). RelativeADC (rADC) was calculated by ADClesion/ADCreference site, and the right erectorspinae was determined to be the reference site for rADC. A receiver operatingcharacteristic (ROC) curve was generated to evaluate the capability of morphological andADC measurements in distinguishing metastatic LNs.Results The short-axis and long-axis diameter of metastatic LNs were larger thannon-metastatic LNs, and differences showed statistic significance (P=0.000, P=0.000).The minimum ADC value and rADC of metastatic lymph nodes were significantly lowerthan that of non-metastatic lymph nodes (P=0.000, P=0.000). The short-axis diameter,long-axis diameter, minimum ADC value and rADC were contributory to differentiatemetastatic from non-metastatic LNs. The area under the ROC curve of minimum ADC wasgreater than that of other criteria. Using the minimum ADC criteria (≤0.878×10-3mm2/s),the sensitivity and specificity for differentiating metastatic from non-metastatic LNs were87.7%and77.4%, respectively. The correlation between ADC-based criteria andsize-based criteria both in metastatic and non-metastatic LNs were found to beinsignificant (P＞0.05). Conclusion ADC value has a high diagnostic efficacy in differentiating metastaticLNS in patient with gastric carcinoma, and minimum ADC shows superior diagnosticperformance.