摘要
目的探讨食管癌磁共振扩散加权成像(DWI)诊断的最佳b值及表观扩散系数(ADC)在食管癌恶性度预测方面的应用价值。方法对初诊为食管癌的45例患者行前瞻性常规MRI平扫及DWI扫描,依据病理结果对照分析不同病理分级食管癌间的ADC值变化。采用单次激发SE-EPI序列,取不同b值(500、800 s/mm^2和1000 s/mm^2)对食管癌患者进行DWI检查,得到相应的DWI及ADC图像。结果食管癌病灶在各组不同b值获得的DWI图像上均表现为高信号,同时病灶的信噪比(SNR)及对比噪声比(CNR)均随着b值的升高而表现为下降;各b值下病灶的ADC值不同,同一b值下不同病理分级间病灶的ADC值亦不相同,食管癌的病理分级可以通过各b值下的ADC值进行有效的评价。绘制ROC曲线后分析得出,当b值为500 s/mm^2时,受试者工作特征曲线(ROC)曲线下面积最大,对食管癌恶性度的预测价值最高,相应的ADC值为1.72×10^(-3)mm^2/s,其敏感度和特异度为85.7%和82.4%。结论 b值为500 s/mm^2时有利于食管癌病灶的检出和显示;ADC值测定可以反映肿瘤的病理分级,对于术前评估食管癌的恶性程度有重要作用,可以为临床治疗及患者预后评价提供更多的信息。
Objective To choose the most appropriate b value of diffusion weighted imaging（ DWI） for the diagnosis of esophageal cancer and to mainly evaluate the value of apparent diffusion coefficient（ ADC） in the malignant degree of esophageal cancer. Methods Forty-five patients preliminarily diagnosed with esophageal carcinoma were asked to undergo the regular MR examination and DWI scans. We analyzed the changes of ADC values in different pathological grades of esophageal cancer based on the pathological results. SE-EPI-DW sequence was used with three groups of different b values（ 500,800 and 1000 s/mm^2） and the corresponding DWI images and ADC images were obtained. Results On DWI image with different b values,the esophageal cancer appeared as a high signal and the SNR as well as the CNR decreased with increasing b value. The ADC values of the esophageal cancer were different with each b value. The ADC values between different pathological grades of esophageal cancer were all statistically different under the same b value and this means that the ADC values obtained from each b value were instrumental in distinguishing the different pathological grades of esophageal cancer. By operating the characteristic（ ROC） curve,we can see that with the b value of 500 s / mm^2,the area under ROC curve was the largest and the diagnosis value for esophageal cancer is the highest. The corresponding value of ADC was 1. 72 × 10^-3mm^2/ s,its sensitivity and specificity were 85. 7% and 82. 4%. Conclusion The measurement of ADC values can reflect the different pathological grades of cancer and this is important for evaluating the degree malignancy before operation and also provides more information for clinical treatment and prognostic evaluation.
出处
《临床放射学杂志》
CSCD
北大核心
2016年第5期763-767,共5页
Journal of Clinical Radiology
关键词
食管癌
扩散加权成像
表观扩散系数
病理分级
Esophageal cancer
Diffusion weighted imaging
Apparent diffusion coefficient
Pathological grades
