Department of Radiology, Ultramedica Clinic.
Ultraschall Med. 2012 Dec;33(7):E68-E74. doi: 10.1055/s-0029-1245951. Epub 2011 Feb 3.
The aim of this study was to measure the two frontomaxillo-facial (FMF) angles: the FMF-vomer (FMF-v) and the FMF-palate (FMF-p), and to visualize the vomer in the 1(st) and early 2(nd) trimester, in order to ascertain whether they can be used as markers for trisomy 21 and trisomy 13.
A 2D ultrasound scan was performed in the 340 normal and 12 abnormal pregnancies, using the linear, convex and endovaginal probes.
We visualized the FMF angles within 1 to 5 minutes in 253 (72 %) of cases by using the linear probe. FMF-v angle was significantly smaller that the FMF-p angle (79.8° vs. 89.7°, 71.5° vs. 84.5° for the two trimesters, respectively), and that the value of both angles decreased in the second trimester. There was not one single case of trisomy in which vomer could be identified in the 1 (st) and early 2 (nd) trimester. The FMF-p angle failed to present difference between normal cases and the ones with trisomy (89.5°). There was not one single case of trisomy (21 or 13) in which vomer or FMF-v could be identified in the first or early second trimester. The diagnostic accuracy of vomer as a marker for trisomy was 0.985.
If the vomer cannot be visualized in the 1 (st) and early 2 (nd) trimester, it is important to check the karyotype, and it is not necessary to measure the FMF-p angle. The high resolution probe (L 12 - 5 Mhz) enables easier assessment of the vomer.
本研究旨在测量两个额上颌（FMF）角：FMF-犁骨（FMF-v）和 FMF-硬腭（FMF-p），并在第一和第二孕早期可视化犁骨，以确定它们是否可作为唐氏综合征 21 号和 13 号三体的标志物。
使用线性、凸形和经阴道探头对 340 例正常妊娠和 12 例异常妊娠进行二维超声检查。
我们使用线性探头在 253 例（72%）病例中在 1 至 5 分钟内可视化了 FMF 角。FMF-v 角明显小于 FMF-p 角（第一和第二孕早期分别为 79.8°和 89.7°，71.5°和 84.5°），并且两个角度在第二孕早期都减小。在第一和第二孕早期，没有一个三体病例可以识别犁骨。FMF-p 角在正常病例和三体病例之间没有差异（89.5°）。在第一或早期第二孕早期，没有一个三体（21 号或 13 号）病例可以识别犁骨或 FMF-v。犁骨作为三体标志物的诊断准确性为 0.985。
如果在第一和第二孕早期无法可视化犁骨，则检查染色体核型很重要，没有必要测量 FMF-p 角。高分辨率探头（L 12-5 MHz）可以更轻松地评估犁骨。
