Three-Dimensional Crystal Vue Imaging technology assessment of Sylvian fissures at 20-32+6 weeks' normal gestation

Assess developmental pattern of Sylvian fissures (SF) with Three-Dimensional Crystal Vue Imaging (3D-CVI) at 20-32⁺⁶ weeks of gestation.

This was a prospective cross-sectional study. Assess 20-32⁺⁶ weeks' gestation normal development of fetal brain SF with 3D-CVI imaging. Measure the uncovered area and perimeter of the insula on the Three-Dimensional (3D) image and establish reference ranges for the uncovered area and perimeters of the insula during normal pregnancy 20-32⁺⁶ weeks' gestation. Examine intra- and interobserver repeatability of measurements of the uncovered area and perimeter of the insula.

A total of 286 normal fetuses from 20 to 32⁺⁶ weeks of gestation were studied. The SF first was trapezoidal in the 25 weeks of gestation, gradually becoming triangular as gestational age (GA) increased, and then closing from posterior up to anterior down. The uncovered area and dimension of the insula showed a parabolic curve that first increased and then decreased as GA and head circumference (HC) increased. Reference ranges for measurements of the uncovered area and perimeters of the insula during normal pregnancy 20-32⁺⁶ weeks' gestation were established. The intra- and interobserver agreements were reproducible (all ICC > 0.850); there were more than 95% dots in the Bland-Altman plots (95 limits of agreement (LOA)) scale in every figure.

3D-CVI can be used to observe the morphological changes of SF during middle and late pregnancy, which is an intuitive supplementary means for prenatal evaluation of cerebral cortex development, guiding subsequent follow-up and referral for assessment by expert neurosonologists.

• A new imaging technique was found to visualize the SF of fetal brain surface. • This technique has the advantages of good consistency and repeatability, simple operation, short time-consuming, and low cost. • Its 3D visualization images can be used to the development and changes of the sulci on the brain surface, it provides a new method to evaluate the development of cerebral cortex.