新的内括约肌测量方法：可行性研究。

New method for internal anal sphincter measurements: feasibility study.

机构信息

First Clinical Division of General Surgery, Anaesthesiological and Surgical Science Department, University Hospital of Verona, Verona, Italy.

出版信息

Int J Comput Assist Radiol Surg. 2010 Sep;5(5):515-25. doi: 10.1007/s11548-010-0406-y. Epub 2010 Feb 24.

DOI:10.1007/s11548-010-0406-y

PMID:20180035

Abstract

PURPOSE

The aim of this paper is to provide a method for measuring the internal anal sphincter on the basis of the quantitative analysis of three-dimensional endosonographic images. A software calculates a large set of measurements which are able to describe the three-dimensional shape of the muscle.

METHODS

A software provides four types of measurements: thickness, length, area and volume. The different magnitudes are estimated using the same reference system. The measurements obtained are modeled by functions that describe their spatial trend. The precision and reproducibility of the method was tested on a phantom before a study was performed on fifteen healthy patients. The measurements were carried out by two different operators. The inter-observer variability were assessed.

RESULTS

In the phantom measurements the mean errors and the standard deviation were: 0.05 +/- 0.1 mm for the thickness, 0.02 +/- 0.12 mm for the length, -4.43 +/- 2.4 mm(2) for the area, -20.69 +/- 20.83 mm(3) for the volume. The maximum absolute differences between the measurements carried out by the two operators was: 0.18 mm for the thickness (in the 95% of the case), 1.69 mm(2) for the area (in the 95% of the case), and 0.25 mm for the length, and 29.46 mm(3) for the volume. The human IAS assessments were evaluated on each segment. The mean of the all tissue measurements carried out were (mean +/- SD): 1.71 +/- 0.34 mm for the thickness, 33.24 +/- 6.10 mm for the length, 111.28 +/- 29.08 mm(2) for the area. The mean of the volume measurements of the entire tissue was: 4124 +/- 1160 mm(3). Inter-observer variability was observed only in the anterior proximal segment for the thickness measurements by Wilcoxon's signed rank test (P value = 0.048) and for the volume assessments by the limits of agreement method (-118 to 78 mm(3)). The mean percentage errors and the limit of agreement for the measurements of the entire tissue were: 0.27 and (-0.11 to 0.12 mm) for the thickness, -2.32 and (-3.88 to 2.33 mm) for the length, -0.05 and (-9.71 to 9.83 mm(2)) for the area, -1.89 and (-366 to 240 mm(3)) for the volume.

CONCLUSION

The assessments of accuracy and precision of the method result satisfactory for all four type of measurements. The reproducibility analysis confirms very good inter-observer agreement for the phantom measurements and for the most part of the IAS segments evaluations. Inter-observer variability was seen only for the thickness and volume measurements of the anterior-proximal segment. Our method provides a high number of measurements with good accuracy enabling a very detailed study of IAS morphology.

摘要

目的

本文旨在提供一种基于三维内视镜超声图像定量分析测量内括约肌的方法。一个软件可以计算出大量的测量值，这些测量值能够描述肌肉的三维形状。

方法

该软件提供了四种类型的测量值：厚度、长度、面积和体积。使用相同的参考系统来估计不同的量值。使用描述其空间趋势的函数对获得的测量值进行建模。在对 15 名健康患者进行研究之前，我们在体模上测试了该方法的精密度和可重复性。由两名不同的操作人员进行测量。评估了观察者间的可变性。

结果

在体模测量中，平均误差和标准差分别为：厚度为 0.05±0.1mm，长度为 0.02±0.12mm，面积为-4.43±2.4mm(2)，体积为-20.69±20.83mm(3)。两名操作人员之间测量的最大绝对差异为：厚度为 0.18mm（95%的情况下），面积为 1.69mm(2)（95%的情况下），长度为 0.25mm，体积为 29.46mm(3)。对每个节段的人类 IAS 评估进行了评估。所有组织测量的平均值为（平均值±标准差）：厚度为 1.71±0.34mm，长度为 33.24±6.10mm，面积为 111.28±29.08mm(2)。整个组织体积测量的平均值为：4124±1160mm(3)。仅在前部近端节段观察到观察者间的可变性，这是通过 Wilcoxon 符号秩检验（P 值=0.048）对厚度测量和通过一致性界限法（-118 至 78mm(3)）对体积评估进行评估的。整个组织测量的平均百分比误差和一致性界限为：厚度为 0.27 和（-0.11 至 0.12mm），长度为-2.32 和（-3.88 至 2.33mm），面积为-0.05 和（-9.71 至 9.83mm(2)），体积为-1.89 和（-366 至 240mm(3)）。