Department of Radiology, University of California, San Diego, San Diego, California, USA.
Maternal-Fetal Care and Genetics, University of California, San Diego, La Jolla, California, USA.
J Ultrasound Med. 2022 Aug;41(8):1907-1914. doi: 10.1002/jum.15867. Epub 2021 Nov 9.
To demonstrate the significance of the double line appearance of the septi pellucidi laminae (SPL) on fetal ultrasound.
A total of 522 uncomplicated singleton pregnancies (15 to 39 weeks' gestational age) with fetal ultrasounds were enrolled. The presence of a single versus double line SP as well as measurement of the cavum septi pellucidi (CSP) was determined retrospectively. Ultrasound settings from the CSP images were recorded. Thickness of the SPL was measured in 20 ultrasound and 14 MRI cases; histology was reviewed from one neonate. Maternal BMI and gestational age were also recorded.
The presence of double line SPL is a normal sonographic finding, seen in 47% (188/403) of normal fetuses. Thickness of the SPL in 10 cases with double line averaged 1.4 mm and in 10 cases with single line averaged 0.8 mm; MRI measurements were within 0.1 mm of the corresponding ultrasound measurements. Double line cavum was more often seen with mid-dynamic contrast range settings (5, 6) rather than high range settings (7-10) (P value <.05). The double line was only visualized on ultrasound when the angle of insonation was at or near perpendicular to the laminae; it was never visualized on coronal ultrasound imaging or MRI imaging.
A double line septum pellucidum lamina is a normal finding seen in almost 50% of uncomplicated singleton pregnancies. It may be attributed to borders of cell layers within each lamina that form separate specular reflections on both sides; this can be accentuated by ultrasound settings and beam angulation.
展示胎儿超声中透明隔板双层线外观的意义。
共纳入 522 例单纯性单胎妊娠（15 至 39 孕周）的胎儿超声检查。回顾性确定存在单层还是双层透明隔板（SPL）以及测量透明隔腔（CSP）。记录 CSP 图像的超声设置。在 20 例超声和 14 例 MRI 病例中测量 SPL 厚度；从一名新生儿中复查组织学。还记录了母亲的 BMI 和孕龄。
双层 SPL 的存在是一种正常的超声表现，在 47%（188/403）的正常胎儿中可见。10 例双层 SPL 厚度平均为 1.4mm，10 例单层 SPL 厚度平均为 0.8mm；MRI 测量值与相应的超声测量值相差 0.1mm 以内。双层透明隔腔更常见于中动态对比范围设置（5、6），而不是高范围设置（7-10）（P 值<0.05）。只有当超声入射角与板层平行或接近平行时，才能在超声上看到双层；在冠状超声成像或 MRI 成像上从未看到过。
双层透明隔板是一种在近 50%的单纯性单胎妊娠中常见的正常表现。它可能归因于每个板层内细胞层的边界，在两侧形成单独的镜面反射；这可以通过超声设置和光束角度来增强。
