Department of Radiology, Shiga University of Medical Science, and Kusatsu General Hospital, Seta, Tsukinowa, Otsu, Shiga 520-2192, Japan.
Eur J Radiol. 2011 Dec;80(3):e524-30. doi: 10.1016/j.ejrad.2010.12.035. Epub 2011 Jan 26.
To assess the reliability of CT airway measurement using phantom and to evaluate its reproducibility using clinical chest CT images.
The phantom consisted of six tubes with different diameters and wall thicknesses was used. The wall area ratio (%WA) and wall thickness ratio (%WT) were calculated and the difference from the actual value (error ratio) was assessed. In vivo validation was performed with MDCT data of consecutive 10 patients and inter- and intra-rater agreements of the measurement were evaluated.
The error ratio of %WA and %WT increased for the phantom tube with a 1mm or thinner wall thickness. The FOV size has an influence on the airway measurement especially for the tube with 1mm wall thickness. Inter-rater reliabilities between two observers for %WA and %WT were excellent and good intra-class correlation coefficient for %WA and %WT were obtained as 0.825 and 0.811, respectively. Intra-rater reliabilities of measurement also showed good intra-class correlation coefficient for %WA and %WT as 0.822 and 0.800, respectively.
Although the phantom study showed there is a tendency to overestimate the wall area of an airway with a thickness 1mm or less, the software has a potential to be used in assessing longitudinal observation of the same patient, as well as, comparison among different patients due to good intra- and inter-rater reliability.
评估使用体模进行 CT 气道测量的可靠性，并评估使用临床胸部 CT 图像的可重复性。
该体模由六个具有不同直径和壁厚的管子组成。计算了壁面积比（%WA）和壁厚比（%WT），并评估了与实际值的差异（误差比）。对连续 10 例患者的 MDCT 数据进行了体内验证，并评估了测量的组内和组间一致性。
对于壁厚为 1mm 或更薄的管，%WA 和 %WT 的误差比增加。视野大小对气道测量有影响，特别是对于壁厚为 1mm 的管。两位观察者之间的 %WA 和 %WT 的组内可靠性均为优秀，%WA 和 %WT 的组内相关系数分别为 0.825 和 0.811。测量的组内可靠性也显示出 %WA 和 %WT 的良好组内相关系数，分别为 0.822 和 0.800。
尽管体模研究表明，对于厚度为 1mm 或更薄的气道，存在高估壁面积的趋势，但由于良好的组内和组间可靠性，该软件具有用于评估同一患者的纵向观察以及不同患者之间比较的潜力。
