Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
Leipzig Ultrasound Institute, Rödelstraße 24, 04229 Leipzig, Germany.
J Dairy Sci. 2019 Oct;102(10):9488-9494. doi: 10.3168/jds.2019-16670. Epub 2019 Aug 14.
Ample research has described the assessment of dimensional changes for different teat traits, whereas diagnostic techniques to reliably assess blood circulation in teats of dairy cows are limited. Here, we describe the development and evaluation of a scanning technique to quantify blood flow in teats of dairy cows using power Doppler ultrasonography. In 2 consecutive trials, 384 teat scans [trial 1, n = 256 (sagittal plane, n = 128; transverse plane, n = 128); trial 2, n = 128 (transverse plane)] from 16 cows were obtained by the same 2 operators. Perfusion intensity from single images (trial 1) and video images (trial 2) were assessed using a commercially available software program. Intraclass correlation coefficients (ICC) and concordance correlation coefficients (CCC) were used to assess interoperator reproducibility (agreement between measurements performed by different operators) and intraoperator repeatability (agreement between measurements performed by the same operator). In trial 1, interoperator ICC and CCC indicated poor agreement (ICC ≤0.26, CCC ≤0.26). Intraoperator ICC and CCC demonstrated poor agreement between duplicate measurements within operators (ICC ≤0.19, CCC ≤0.19). Modifications after trial 1 included (1) a different ultrasound device, (2) analysis of video clips rather than single images, (3) restriction to 1 sectional plane (i.e., transverse), and (4) a scanning sequence such that repeated scans within operators were measured one after another. Through these modifications, intraoperator repeatability in trial 2 yielded fair to good agreement, with intraoperator ICC and CCC over both operators ranging from 0.44 to 0.70 and from 0.57 to 0.69, respectively, whereas interoperator ICC and CCC showed poor agreement (ICC = 0.35, CCC = 0.34). We conclude that repeatable measurements of blood perfusion intensity of teats in dairy cows can be attained with power Doppler ultrasonography. Power Doppler ultrasonography is a suitable tool to quantify slow flow in small vessels and may be an acceptable diagnostic technique to assess changes in blood circulation that result from machine milking in teats of dairy cows, although further research is necessary to validate this hypothesis.
大量研究已经描述了不同乳头特征的尺寸变化评估，而用于可靠评估奶牛乳头血液循环的诊断技术却很有限。在这里，我们描述了一种使用功率多普勒超声技术量化奶牛乳头血流量的扫描技术的开发和评估。在 2 项连续试验中，由 2 名操作人员对 16 头奶牛的 384 个乳头扫描（试验 1：矢状面，n=128；横切面，n=128；试验 2：横切面，n=128）进行了操作。使用商业可用软件程序评估来自单个图像（试验 1）和视频图像（试验 2）的灌注强度。使用组内相关系数（ICC）和一致性相关系数（CCC）评估操作者间再现性（不同操作者进行的测量之间的一致性）和操作者内重复性（同一操作者进行的测量之间的一致性）。在试验 1 中，操作者间 ICC 和 CCC 表明一致性差（ICC≤0.26，CCC≤0.26）。操作者内 ICC 和 CCC 表明操作者内重复测量之间一致性差（ICC≤0.19，CCC≤0.19）。试验 1 后进行了以下修改：（1）使用不同的超声设备；（2）分析视频剪辑而不是单个图像；（3）限制在 1 个剖切面（即横切面）；（4）扫描顺序使得同一操作者内的重复扫描一个接一个地进行测量。通过这些修改，试验 2 中的操作者内重复性得到了良好到中等的一致性，同一位操作者内的 ICC 和 CCC 分别在两位操作者之间的范围从 0.44 到 0.70 和从 0.57 到 0.69，而操作者间 ICC 和 CCC 则显示出一致性差（ICC=0.35，CCC=0.34）。我们得出结论，使用功率多普勒超声可以实现奶牛乳头血流量的可重复测量。功率多普勒超声是量化小血管中缓慢血流的合适工具，可能是一种可接受的诊断技术，可以评估机器挤奶对奶牛乳头血液循环变化的影响，尽管需要进一步研究来验证这一假设。
