BACKGROUND:Tumor burden is difficult to estimate by endoscopy and conventional EUS. OBJECTIVE:The purpose of this study was to determine the accuracy and the reliability of a new 3-dimensional (3D) EUS system in a pseudotumor model (Olympus EUS EXERA EU-M60). DESIGN:A pseudotumor model was developed in a porcine stomach. Pseudotumors were created by injecting various volumes of US gel (0.3, 0.5, 0.7, and 1 mL) into porcine stomach specimens, and then the volume was measured in vitro. Two investigators made volume measurements by outlining the cross-sectional area of the pseudotumor at different radial planes. The instrument then automatically calculated the volume based on the outlined cross-sectional areas. The measured volume was compared with the actual volume of the pseudotumor by using a Bland-Altman analysis. Every second, third, fourth, fifth, sixth, and tenth image was measured to calculate the tumor volume and to determine the optimum number of images required for accurate volume determination. Inter- and intraobserver variability, percentage error, Bland-Altman analysis, analysis of variance (ANOVA), and kappa statistic were performed. SETTING:This study was performed in an in vitro animal model. PATIENTS:There were no patients involved in this study. MAIN OUTCOME MEASUREMENTS:Accuracy and reliability of pseudotumor volume measurement. RESULTS:When averaging across all measurements, the overall average mean error was 3.25%. The overall inter-rater reliability as measured by intraclass correlation coefficient was 0.78. The overall intra-rater reliability as measured by intraclass correlation coefficient was 0.99. Bland-Altman analysis and ANOVA showed similar low variability for measured volumes based on image frequencies for volume calculations between every other and every sixth image but greater variability for measured volumes based on every tenth image. Larger pseudotumors were measured with a slight decrease in mean percentage error. The kappa statistic for interobserver variability was .61, which demonstrated substantial agreement among observers. LIMITATIONS:The major limitation of this technology is the penetration of the US beam to evaluate large tumors, because the US transducer is high frequency (20 MHz) and, therefore, has a limited penetration. CONCLUSIONS:In conclusion, the new Olympus EUS EXERA EU-M60 3D US probe allowed for accurate volume measurements of small pseudotumors in porcine stomach model in vitro. There was substantial evaluator agreement, with a low interobserver variability. Larger pseudotumors were measured with a slightly lower percentage error than smaller pseudotumors. Volumes measured with a greater number of radial images were measured slightly more accurately. We plan to test this device in patients with GI tumors in the near future.

译文

背景:难以通过内窥镜检查和常规EUS评估肿瘤负担。
目的:本研究的目的是确定伪肿瘤模型(Olympus EUS EXERA EU-M60)中新的3维(3D)EUS系统的准确性和可靠性。
设计:在猪胃中建立了假肿瘤模型。通过将各种体积的US凝胶(0.3、0.5、0.7和1 mL)注入猪胃标本中来创建假瘤,然后在体外进行测量。两名研究人员通过概述假瘤在不同径向平面上的横截面积来进行体积测量。然后,仪器会根据轮廓截面积自动计算体积。通过使用Bland-Altman分析将测得的体积与假瘤的实际体积进行比较。每隔第二,第三,第四,第五,第六和第十个图像进行测量以计算肿瘤体积并确定准确确定体积所需的最佳图像数量。进行了观察者之间和观察者内部的变异性,百分比误差,Bland-Altman分析,方差分析(ANOVA)和kappa统计。
地点:这项研究是在体外动物模型中进行的。
患者:本研究无患者参与。
主要观察指标:假瘤体积测量的准确性和可靠性。
结果:所有测量结果取平均值时,总体平均平均误差为3.25%。通过类内相关系数测得的整体评分者间可靠性为0.78。通过类别内相关系数测得的整体内部评分者信度为0.99。 Bland-Altman分析和方差分析显示,基于图像频率的测量体积的相似性低变异性,用于每隔一张和每第六张图像之间的体积计算,但基于每十分之一图像的测量体积变异性更大。测量较大的假瘤,平均百分比误差略有降低。观察者间差异的kappa统计值为.61,表明观察者之间存在重大共识。
局限性:该技术的主要局限性在于US束穿透性大,以评估大型肿瘤,因为US换能器的频率很高(20 MHz),因此穿透性有限。
结论:总而言之,新的Olympus EUS EXERA EU-M60 3D US探针可在猪胃模型中对小假瘤进行精确的体积测量。评估者之间达成了一致意见,观察者之间的差异很小。与较小的假瘤相比,测量较大的假瘤的百分比误差略低。用更多数量的径向图像测量的体积稍微更精确地测量。我们计划在不久的将来在胃肠道肿瘤患者中测试该设备。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录