Frauenarztpraxis Bahnhofstraße, Wolfenbüttel.
Ultraschall Med. 2011 Dec;32 Suppl 2:E147-50. doi: 10.1055/s-0031-1281648. Epub 2011 Aug 29.
Novel aneuploidy screening has been suggested for measuring the yolk sac during very early pregnancy. However, in a pilot study the measured diameters differed up to 29 % from the overall average. The aim of this study was to analyze the impact of image magnification on yolk sac measurement.
From November 3, 2009 to July 28, 2010, 119 yolk sac measurements were performed. During each examination, each yolk sac was examined once with standard image magnification and once by live scan zoom.
The measurement values were 5 % smaller in the standard image. The mean relative ratio (RR), median RR, and standard deviation (SD) were 0.951, 0.950, and 0.103 mm, respectively (95 % CI 0.744 to 1.158 mm). Regarding absolute differences, the mean, median, and standard deviation were -0.222 mm, -0.220 mm, and 0.473 mm, respectively, (95 % CI -1.169 to + 0.725 mm). With standard zoom (magnified images), the SD was 1.142 mm (1.099 mm).
Five criteria should be regarded for optimal image settings: image magnification during live scan, optimal gain setting, enhanced gamma level, median section plane, and out-to-out caliper placement.
新型非整倍体筛查已被建议用于测量极早期妊娠的卵黄囊。然而，在一项初步研究中，所测量的直径与总体平均值相差高达 29%。本研究旨在分析图像放大对卵黄囊测量的影响。
2009 年 11 月 3 日至 2010 年 7 月 28 日，共进行了 119 次卵黄囊测量。在每次检查中，每个卵黄囊均以标准图像放大和实时扫描放大各检查一次。
标准图像下的测量值小 5%。平均相对比（RR）、中位数 RR 和标准差（SD）分别为 0.951、0.950 和 0.103 mm（95%置信区间 0.744 至 1.158 mm）。关于绝对差值，平均值、中位数和标准差分别为-0.222 mm、-0.220 mm 和 0.473 mm（95%置信区间-1.169 至+0.725 mm）。使用标准缩放（放大图像），SD 为 1.142 mm（1.099 mm）。
应注意五个最佳图像设置标准：实时扫描时的图像放大、最佳增益设置、增强的伽马水平、中位数截面平面和内外卡尺放置。
