OC10.05: Prenatal sonographic evaluation of the frontal brain sulcation: qualitative and quantitative assessment with pathologic correlations

Describe neurosonographic appearance of lateral frontal sulci between 28+0- and 32+6-weeks' gestation in fetuses with normal and abnormal sulcation development. This is a retrospective analysis of TV-US 3D datasets of 100 typically developed and 6 fetuses with sulcation disorders. The anterior coronal plane was analysed for the superior frontal sulcus (SFS), middle frontal sulcus (MFS), and inferior frontal sulcus (IFS) using 1) a subjective scale (absent, indentation, triangle, line) and 2) measurement of the angle between the lips of each sulci (see figure 1A). We assessed the symmetry of sulcation between hemispheres, and the correlation between sulcation angles, gestational age, and cranial biometry. In the controls, the SFS and IFS were present in 90% of fetuses by 29 weeks' gestation, changing in appearance from an indentation to a line by 32 weeks'. The MFS was inconsistently present. The SFS and IFS sulcation angle decreased with gestational age (p < 0.0001) and did not correlate with head circumference measurements. No differences were observed between hemispheres. In fetuses with sulcation disorders, asymmetry between hemispheres was the most common finding (n = 5, 83%). In 2 cases of syndromic megalencephaly, there was evidence of over-sulcation with multiple small sulci and no distinct SFS or IFS (see figure 1B). The remaining 4 cases showed delayed sulcation, with the SFS and IFS absent or underdeveloped for gestational age (lissencephaly/ simplified gyral pattern) (see figure 1C). In normal development, the lateral frontal sulci follow a predictable symmetrical trajectory which is independent of head circumference. Deviation from this trajectory may be associated with disorders of sulcation development. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.