Hepatic Tumors: Region-of-Interest versus Volumetric Analysis for Quantification of Attenuation at CT
Hepatic Tumors: Region-of-Interest versus Volumetric Analysis for Quantification of Attenuation at CT
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DOI：
10.1148/radiol.11110106
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发表时间：
2012-03-01
期刊：
影响因子：
19.7
通讯作者：
Yaghmai, Vahid
中科院分区：
文献类型：
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作者：
Chalian, Hamid;Tochetto, Sandra M.;Yaghmai, Vahid
目的：评价常规使用的人工感兴趣区(ROI)方法和半自动CT容积方法测量肝脏肿瘤衰减的可重复性。材料和方法：这项符合HIPAA标准的回顾性研究获得了机构评审委员会的批准。免除了对患者知情同意的要求。208例结肠癌肝转移灶在门静脉期多探测器CT图像上采用单一感兴趣区(单个层面上三个感兴趣区的平均值)和半自动分割整个肿瘤体积(体积衰减)的方法来测量，以评估方法间的一致性。对前70名患者进行了观察者内和观察者间的重复性评估。30天后重复测量以评估观察者内的重复性。方法间的差异采用重复测量方差分析进行检验。使用Bland-Altman分析和LIN一致性相关系数(Rho(C))对方法间、观察者内和观察者间的一致性进行检验。结果：总共评估了208例直径大于20 mm的结肠癌肝转移患者，其中100名女性和108名男性(平均年龄61.6岁+/-11.6岁，范围28-87岁)。三种测量方法之间的衰减有显著差异(P<；均为.001)。与单一感兴趣区测量(精度=12.0%，Rho(C)=0.947，P<；.001)和三个感兴趣区的平均测量值(精度=9.3%，Rho(C)=0.965，P<；.001)相比，体积测量具有更好的观察者间一致性(精度=3.3%，Rho(C)=0.996，P&t；.001)。与单一感兴趣区测量(精度=11.3%，Rho(C)=0.957，P<；.001)和三个感兴趣区的平均值(精度=8.5%，Rho(C)=0.976，P<；.001)相比，体积测量的观察者间一致性(精度=3.6%，Rho(C)=0.993，P<；.001)更好。一种基于整体病变衰减评估的方法显示出比ROI测量更好的重复性。
Purpose: To evaluate the reproducibility of liver tumor attenuation measurement performed by using the routinely used manual region-of-interest (ROI) method and that of measurement performed by using a semiautomated volumetric approach at computed tomography (CT).Materials and Methods: This HIPAA-compliant retrospective study had institutional review board approval. The requirement for patient informed consent was waived. Attenuation of colon cancer liver metastases in 208 patients was measured on portal venous phase multidetector CT images by using a single ROI, the average measurement in three ROIs on a single section, and with semiautomated segmentation of the entire tumor volume (volumetric attenuation) to evaluate intermethod agreement. Intraobserver and interobserver reproducibility were evaluated in the first 70 patients. Measurements were repeated after 30 days to assess intraobserver reproducibility. Differences between methods were tested by using repeated-measures analysis of variance. Intermethod, intraobserver, and interobserver agreements were tested by using Bland-Altman analysis and the Lin concordance correlation coefficient (rho(c)). P < .05 was considered to indicate a significant difference.Results: A total of 208 pathologically proven colon cancer hepatic metastases larger than 20 mm in diameter in 100 women and 108 men (mean age, 61.6 years +/- 11.6 [standard deviation]; range, 28-87 years) were evaluated. Attenuation was significantly different between the three methods of measurement (P < .001 for all). Volumetric measurements had better intraobserver agreement (precision = 3.3%, rho(c) = 0.996, P < .001) than single-ROI measurements (precision = 12.0%, rho(c) = 0.947, P < .001) and measurements averaged over three ROIs (precision = 9.3%, rho(c) = 0.965, P < .001). Volumetric measurements also had better interobserver agreement (precision = 3.6%, rho(c) = 0.993, P < .001) than single-ROI measurements (precision = 11.3%, rho(c) = 0.957, P < .001) and the average measurement in three ROIs (precision = 8.5%, rho(c) = 0.976, P < .001).Conclusion: Measurements of hepatic tumor attenuation at multidetector CT are reproducible. An approach based on the evaluation of whole-lesion attenuation demonstrated better reproducibility than ROI measurements.