DWI及ADC值对胃癌转移淋巴结的诊断价值  

The Diagnostic Value of Diffusion Weighted Imaging and ADC Values in the Determination of Lymph Node Metastases of Gastric Cancer

作　　者：杨虹[1] 李雪霜[1] 陆通[1] 张琴 樊芮娜 朱凯[2] 郭玉林[2] 

机构地区：[1]宁夏医科大学,750004 [2]宁夏医科大学总医院放射科,750004

出　　处：《临床放射学杂志》2017年第9期1271-1275,共5页Journal of Clinical Radiology

基　　金：宁夏自然基金项目(基金号:NZ14145);2015宁夏研究生教育创新计划项目(编号:NXYC201511)

摘　　要：目的探究磁共振扩散加权成像(DWI)及表观扩散系数(ADC)值对胃癌转移性淋巴结的鉴别诊断价值。方法搜集26例行常规MR及DWI检查,后经胃镜组织活检证实为胃癌的影像学资料,以术后病理结果为金标准,测量转移性、非转移性淋巴结的短径、长径、相对ADC值(r ADC)(平均ADC值/右肾门水平右侧竖脊肌ADC值),以上指标通过受试者工作特征曲线(ROC)曲线下面积(Az)来比较其在区别胃癌转移性、非转移性淋巴结的诊断效能。结果 DWI图像与手术后组织病理对照,其中53枚是转移性的、67枚是非转移性的淋巴结,转移性、非转移性淋巴结的短径、长径对比,二者之间差异无统计学意义(P>0.05);而转移淋巴结的r ADC值(0.719±0.075)低于非转移淋巴结的r ADC值(0.977±0.079),二者之间差异有统计学意义(P=0.000)。r ADC阈值=0.807,其敏感性、特异性、准确性、阳性预测值、阴性预测值分别为79.2%、73.1%、80.2%、82.2%、81.6%,诊断效能最高。结论 DWI及ADC值能很好地鉴别胃癌转移与非转移淋巴结,与常规MR序列相比,DWI能提供更多生理学和功能学信息,以协助临床诊断。Objective To explore the diagnostic value of diffusion weighted imaging（ DWI） and ADC values in the determination of lymph node metastasis of gastric cancer. Methods 26 cases of gastric cancer were confirmed by gastroscope biopsy with preoperative routine MR and DWI scans before surgery. Short-axis diameter,long-axis diameter,the relative ADC values were measured in metastatic and non-metastatic Lymph nodes; the latter was calculated by ADC lesion/the right erector spinae. A receiver operating characteristic（ ROC） curve was generated to evaluate the capability of short-axis diameter,long-axis diameter and the r ADC in distinguishing metastatic lymph nodes. Results 53 Lymph nodes and 67non-metastatic ones were successfully dissected according to the DWI. The differences of the short-axis diameter and longaxis diameter between the two groups was not statistically significant（ P〉 0. 05）. However,the r ADC value of the metastatic Lymph nodes（ 0. 719 ± 0. 075） was lower than that of non-metastatic ones（ 0. 977 ± 0. 079）,with significant difference（ P =0. 000）. When the r ADC value was chosen as 0. 807,the area under the ROC curve is greater than all other criteria,such as short-axis diameter,long-axis diameter and the r ADC. The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value for differentiating two groups were 79. 2%,73. 1%,80. 2%,82. 2%,81. 6%,respectively. Conclusion Diffusion-weighted imaging and ADC values is a promising new technique for differentiating metastatic Lymph nodes from non-metastatic ones. Compared with routine magnetic resonance sequences,DWI could provide more useful physiological and functional information for diagnosis.

关 键 词：胃癌 淋巴结 磁共振扩散加权成像 表观扩散系数 

分 类 号：R445.2[医药卫生—影像医学与核医学] R735.2[医药卫生—诊断学]