Department of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Haeundae-ro 875, Haeundae-gu, Busan, Republic of Korea.
Department of Radiology, Seoul National University Hospital, 101, Daehak-ro, Jongno-gu, Seoul, Republic of Korea.
Eur Radiol. 2020 Jan;30(1):206-212. doi: 10.1007/s00330-019-06385-4. Epub 2019 Aug 9.
To evaluate the intraobserver and interobserver reliability of gallbladder polyp measurements using transabdominal US and the factors that affect reliability.
From November 2017 to February 2018, two radiologists measured the maximum diameter of 91 gallbladder polyps using transabdominal US. Intraobserver and interobserver agreement were determined using 95% Bland-Altman limits of agreement and intraclass correlation coefficients (ICCs). The effects of image settings, polyp location, and polyp size were evaluated by comparing ICCs using z tests.
The intraobserver agreement rates were 0.960 (95% confidence interval [CI], 0.939-0.973) for observer 1 and 0.962 (95% CI, 0.943-0.975) for observer 2. The ICCs between the two observers were 0.963 (95% CI, 0.926-0.979) for the first measurement and 0.973 (95% CI, 0.950-0.984) for the second measurement. The 95% limits of agreement on repeated measurements were 22.3-25.2% of the mean, and those between the two observers were 25.5-34.2% of the mean. ICCs for large polyps (≥ 5 mm) were significantly higher than those for small polyps (< 5 mm). There were no significant differences in the ICCs between image settings and polyp location.
Polyp size measurements using transabdominal US are highly repeatable and reproducible. Polyp size significantly affects the reliability of measurement. Diameter changes of approximately less than 25% may fall within the measurement error; this should be considered while interpreting the change in size during follow-up US, especially for small polyps.
• Gallbladder polyp size measurement using transabdominal US is highly repeatable and reproducible. • Diameter changes of approximately less than 25% should be interpreted carefully, especially in small polyps.
评估经腹超声测量胆囊息肉最大径的观察者内和观察者间可靠性及其影响因素。
本研究于 2017 年 11 月至 2018 年 2 月，由 2 名放射科医生使用经腹超声测量 91 个胆囊息肉的最大径。采用 95%的 Bland-Altman 一致性界限和组内相关系数（ICC）评估观察者内和观察者间的一致性。采用 z 检验比较 ICC，评估图像设置、息肉位置和息肉大小对可靠性的影响。
观察者 1 的观察者内一致性率为 0.960（95%置信区间：0.939～0.973），观察者 2 为 0.962（95%置信区间：0.943～0.975）。两位观察者之间的 ICC 分别为首次测量的 0.963（95%置信区间：0.926～0.979）和第二次测量的 0.973（95%置信区间：0.950～0.984）。重复测量的 95%一致性界限为平均值的 22.3%～25.2%，两位观察者之间的 95%一致性界限为平均值的 25.5%～34.2%。直径≥5mm 的大息肉的 ICC 明显高于直径＜5mm 的小息肉。图像设置和息肉位置对 ICC 无显著影响。
经腹超声测量胆囊息肉大小具有高度可重复性和可再现性。息肉大小显著影响测量的可靠性。直径变化小于约 25%可能属于测量误差范围；在解释后续超声随访中大小的变化时，特别是在测量小息肉时，应考虑到这一点。
