Basic sonographic examination of the fetal brain at 11–13 weeks' gestation: Rationale for a simple and reliable four‐step technique

Abstract

The widespread incorporation of first‐trimester scanning between 11 and 13 weeks' gestation has shifted from the screening of chromosomal abnormalities, mainly by measuring nuchal translucency thickness and visualization of the nasal bone, to a more detailed study of the fetal anatomy leading to early detection of several structural congenital anomalies. This goal can be improved by the routine and focused sonographic assessment of specific anatomic planes and the identification of distinctive landmarks that can help disclosing a particular, non‐evident condition. In this article we present the basis for a basic, early examination of the fetal brain during screening using a four‐step technique, which can be readily incorporated during the first‐trimester scan. The technique includes the focused visualization of the cranial contour, choroid plexuses of the lateral ventricles and midline, aqueduct of Sylvius, brainstem, fourth ventricle, and the choroid plexus of the fourth ventricle. The rationale for this approach is presented and discussed.

First‐trimester ventriculomegaly in fetuses with callosal agenesis: Cause or association?

“…In recent years, there has been an increasing interest in the early diagnosis of structural anomalies, particularly those involving the central nervous system (CNS) 2–4 . This has led to important advances in defining the normal and abnormal sonographic features of the early fetal brain 5,6 …”

“…[2][3][4] This has led to important advances in defining the normal and abnormal sonographic features of the early fetal brain. 5,6 One of the conditions that can be potentially detected at this early gestational age is fetal ventriculomegaly. Unfortunately, there are no diagnostic criteria for defining this condition.…”

Advances in Maternal–Fetal Imaging

“…The scientific background achieved together with the advent of modern real‐time high‐frequency ultrasound probes has enabled a number of congenital defects to be diagnosed early in gestation, shifting from the second to the first trimester of pregnancy. In this view, the authors present a how‐do‐we‐do‐it article in which sonographers are trained in a tutorial in order to examine the fetal brain between 11 and 13 weeks; in the same way, pregnant women undergo calculation of personal risk according to the Fetal Medicine Foundation guidelines 9 …”

“…In this view, the authors present a how-do-we-do-it article in which sonographers are trained in a tutorial in order to examine the fetal brain between 11 and 13 weeks; in the same way, pregnant women undergo calculation of personal risk according to the Fetal Medicine Foundation guidelines. 9 World-renowned experts in the field of the prenatal diagnosis of orofacial malformations will describe the role of 3D/4D ultrasound, fetal magnetic resonance imaging (MRI), and virtual reality as complementary diagnostic tools that have been demonstrated to increase the antenatal detection rate of facial clefting. 10 Fetal MRI is a second-line diagnostic possibility that is used to provide additional information to ultrasound.…”