Johnson Garrett G R J, Zeiler Frederick A, Unger Bertram, Hansen Gregory, Karakitsos Dimitrios, Gillman Lawrence M
Undergraduate Medical Education, University of Manitoba, Winnipeg, MB, Canada.
Departments of Surgery, University of Manitoba, GF439, 820 Sherbrook Street, Winnipeg, MB, R3A 1R9, Canada.
Crit Ultrasound J. 2016 Dec;8(1):18. doi: 10.1186/s13089-016-0053-9. Epub 2016 Nov 10.
Ultrasound measurement of optic nerve sheath diameter (ONSD) appears to be a promising, rapid, non-invasive bedside tool for identification of elevated intra-cranial pressure. With improvements in ultrasound technology, machines are becoming smaller; however, it is unclear if these ultra-portable handheld units have the resolution to make these measurements precisely. In this study, we estimate the accuracy of ONSD measurement in a pocket-sized ultrasound unit.
Utilizing a locally developed, previously validated model of the eye, ONSD was measured by two expert observers, three times with two machines and on five models with different optic nerve sheath sizes. A pocket ultrasound (Vscan, GE Healthcare) and a standard portable ultrasound (M-Turbo, SonoSite) were used to measure the models. Data was analyzed by Bland-Altman plot and intra-class correlation coefficient (ICC).
The ICC between raters for the SonoSite was 0.878, and for the Vscan was 0.826. The between-machine agreement ICC was 0.752. Bland-Altman agreement analysis between the two ultrasound methods showed an even spread across the range of sheath sizes, and that the Vscan tended to read on average 0.33 mm higher than the SonoSite for each measurement, with a standard deviation of 0.65 mm.
Accurate ONSD measurement may be possible utilizing pocket-sized, handheld ultrasound devices despite their small screen size, lower resolution, and lower probe frequencies. Further study in human subjects is warranted for all newer handheld ultrasound models as they become available on the market.
超声测量视神经鞘直径（ONSD）似乎是一种很有前景的、快速、无创的床边工具，用于识别颅内压升高。随着超声技术的改进，设备变得越来越小；然而，尚不清楚这些超便携式手持设备是否具有精确进行这些测量的分辨率。在本研究中，我们评估了袖珍型超声设备测量ONSD的准确性。
利用本地开发的、先前已验证的眼部模型，由两名专家观察者使用两台机器对五个具有不同视神经鞘尺寸的模型进行三次ONSD测量。使用袖珍超声（Vscan，GE医疗）和标准便携式超声（M-Turbo，SonoSite）测量模型。通过Bland-Altman图和组内相关系数（ICC）分析数据。
SonoSite测量者间的ICC为0.878，Vscan测量者间的ICC为0.826。两台机器之间的一致性ICC为0.752。两种超声方法之间的Bland-Altman一致性分析表明，在整个鞘尺寸范围内分布均匀，并且每次测量时Vscan的读数平均比SonoSite高0.33mm，标准差为0.65mm。
尽管袖珍型手持超声设备屏幕小、分辨率低且探头频率低，但仍可能准确测量ONSD。随着所有更新的手持超声模型投放市场，有必要在人体受试者中进行进一步研究。
