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目的评估感兴趣区(ROI)不同设置方法对肝癌(HCC)患者TACE术治疗前后ADC值测量及观察者之间变异的影响。方法 36例经病理证实中晚期肝癌患者于肝动脉栓塞化疗(TACE)术前、术后1个月行扩散加权成像检查(b=1 000)。两位有经验的放射科医生通过三种不同ROI设置方法对肝癌病灶行ADC值测量,这三种方法分别为:整体容积法、最大层面法、多个小样本法,最后对不同ROI设置方法测量的平均ADC±SD值及观察者之间变异的差异用组内相关系数(ICC)进行对比分析。结果三种ROI设置方法在不同观察者间均存在较好的一致性(P>0.05,ICC=0.99)。整体容积法ROI的ICC在TACE术前非常好(0.91),在TACE术后良好(0.79),单层最大层面法在TACE术前、后的ICC分别为0.77和0.63,多个小样本法的ICC分别为0.76和0.37。多个小样本法TACE术前ADC值低于整体容积法或最大层面法。TACE术后的ADC值在整体容积、最大层面或多个小样本ROI间差异无统计学意义。整体容积和最大层面ROI的SD显著大于多个小样本ROI。结论 ROI设置大小和位置对肿瘤的ADC值测量和观察者间变异有相当大的影响。TACE术后观察者间变异性更大。整体容积法获得的肿瘤ADC值最具可重复性的结果。
Objective To evaluate the effect of different settings of ROI on the measurement of ADC value and the variation between observers before and after TACE in patients with hepatocellular carcinoma (HCC). Methods Thirty - six patients with pathologically confirmed advanced hepatocellular carcinoma were examined by diffusion - weighted imaging (T = = 1 000) before surgery and 1 month after surgery. Two experienced radiologists measured ADC values for liver cancer lesions using three different ROI settings. The three methods were volumetric volume method, maximum slice method, and multiple small sample methods. Finally, different ROI setting methods Differences in measured mean ADC ± SD values and between observer variances were compared using the intraclass correlation coefficient (ICC). Results The three methods of setting ROI showed good agreement among different observers (P> 0.05, ICC = 0.99). The ICC of volumetric ROI was very good (0.91) before TACE and good (0.79) after TACE. The ICC of single layer maximum layer before and after TACE were 0.77 and 0.63, respectively. ICC was 0.76 and 0.37 respectively. Multiple small sample TACE preoperative ADC value is lower than the volume or the maximum slice method. TACE ADC value in the overall volume, the largest level or multiple small sample ROI difference was not statistically significant. The SD of the overall volume and the maximum level ROI is significantly larger than the multiple small sample ROIs. Conclusions The size and location of ROI settings have a considerable impact on the measurement of ADC values and interobserver variability in tumors. Interobserver variability was greater after TACE. The most reproducible results were obtained for the ADC values of the tumors obtained by the volumetric method.