ADC全容积直方图在直肠癌分期中的应用

摘要

Objective To investigate the efficacy of histogram analysis of the whole-volume in apparent diffusion coefficient (ADC) for T and N staging in rectal cancer. Methods Thirty-five patients were enrolled and underwent preoperative DWI exam-ination. Tumors were delineated on each slice of the ADC maps. A series of histogram parameters were calculated and correlated with T and N staging by Spearman correlation analysis. The diagnostic performance of each parameter for distinguishing T and N staging was assessed by using the area under the receiver operating characteristic curve(AUC). Repeatability test was used to as-sess the repeatability between observers. Results There were significant correlations between histogram parameters (Histogram width and Skew) and T-staging ( P =0.036,r =0.355;P =0.033,r =0.361). Among all the histogram parameters, histo-gram width and Skew had larger AUC value in differentiating T3from T1/T2tumor, which were 0.716 and 0.720 respectively. However,we didn't find any positive result in whether lymph node metastasis. The intraclass correlation coefficient of 75% histo-gram parameters were more than 0.8 in repeatability test. Conclusion The repeatability of most histogram parameters in rectal cancer is high. Histogram width and Skew correlated significantly with T staging.%目的 探讨ADC全容积直方图在直肠癌TN分期中的应用价值.方法 前瞻性收集经结肠镜病理证实为直肠癌患者35例,术前行磁共振DWI检查.在ADC直方图软件上勾画肿瘤轮廓,计算ADC直方图参数,采用Spearman法分析ADC直方图参数与肿瘤TN分期相关性,用ROC曲线评价各参数诊断TN分期的效能.采用可靠性检验评估观察者间可重复性.结果 参数Histogram width、Skew与肿瘤T分期具有显著相关性( P =0.036,r =0.355;P =0.033,r =0.361);Histogram width、Skew在区分T3与T1/T2期肿块时曲线下面积分别为0.716、0.720.但淋巴结是否转移的指标分析中未发现阳性结果.可靠性检验显示75%的参数组间相关系数在0.8以上.结论 大部分ADC全容积直方图参数在直肠癌应用中可靠性高.其中,Histogram width以及Skew与直肠癌T分期具有显著相关性.