National Research Council, Institute of Clinical Physiology, Lecce, Italy.
Department of Obstetrics and Gynecology, Hospital Santa Caterina Novella, Galatina, Lecce, Italy.
Ultrasound Obstet Gynecol. 2017 Dec;50(6):766-775. doi: 10.1002/uog.17441.
To evaluate the accuracy and reliability of an automatic ultrasound technique for assessment of the angle of progression (AoP) during labor.
Thirty-nine pregnant women in the second stage of labor, with fetus in cephalic presentation, underwent conventional labor management with additional translabial sonographic examination. AoP was measured in a total of 95 acquisition sessions, both automatically by an innovative algorithm and manually by an experienced sonographer, who was blinded to the algorithm outcome. The results obtained from the manual measurement were used as the reference against which the performance of the algorithm was assessed. In order to overcome the common difficulties encountered when visualizing by sonography the pubic symphysis, the AoP was measured by considering as the symphysis landmark its centroid rather than its distal point, thereby assuring high measurement reliability and reproducibility, while maintaining objectivity and accuracy in the evaluation of progression of labor.
There was a strong and statistically significant correlation between AoP values measured by the algorithm and the reference values (r = 0.99, P < 0.001). The high accuracy provided by the automatic method was also highlighted by the corresponding high values of the coefficient of determination (r = 0.98) and the low residual errors (root mean square error = 2°27' (2.1%)). The global agreement between the two methods, assessed through Bland-Altman analysis, resulted in a negligible mean difference of 1°1' (limits of agreement, 4°29').
The proposed automatic algorithm is a reliable technique for measurement of the AoP. Its (relative) operator-independence has the potential to reduce human errors and speed up ultrasound acquisition time, which should facilitate management of women during labor. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
评估一种自动超声技术评估分娩过程中进展角度（AoP）的准确性和可靠性。
39 名处于第二产程、胎儿头位的孕妇接受常规分娩管理，并附加经阴道超声检查。共进行了 95 次采集，分别由创新算法自动测量和经验丰富的超声医师手动测量，后者对算法结果不知情。将手动测量的结果作为算法性能评估的参考。为了克服在超声检查耻骨联合时常见的可视化困难，AoP 的测量通过考虑耻骨联合的质心而不是其远端点作为标志点，从而保证了高测量可靠性和可重复性，同时在评估分娩进展时保持了客观性和准确性。
算法测量的 AoP 值与参考值之间存在很强的统计学显著相关性（r = 0.99，P < 0.001）。自动方法提供的高精度还通过相应的高决定系数（r = 0.98）和低残差误差（均方根误差 = 2°27'（2.1%））得到了强调。通过 Bland-Altman 分析评估两种方法之间的整体一致性，得出了一个可忽略的平均差异为 1°1'（界限为 4°29'）。
所提出的自动算法是一种测量 AoP 的可靠技术。其（相对）操作员独立性有可能减少人为错误并缩短超声采集时间，这应有助于分娩期间的女性管理。版权所有 © 2017 ISUOG。由 John Wiley & Sons Ltd 出版。
