Which finding signifies ventriculomegaly in relation to NTD?

The lemon sign is indicative of ventriculomegaly, particularly when considered alongside neural tube defects (NTDs). It is an ultrasound finding characterized by a distinctive shape of the fetal skull, which appears flattened in the frontal region and pointed at the occipital area. This configuration often occurs due to dysgenesis of the cerebellum and is commonly observed in conditions such as spina bifida.

Ventriculomegaly itself refers to the enlargement of the brain's ventricles, which is often associated with NTDs. The presence of the lemon sign suggests underlying structural brain changes that may occur with NTDs and indicates that further evaluation is warranted to assess the extent of the neuroanatomical anomalies.

In contrast, other signs, such as the olive sign and banana sign, relate to different aspects of fetal development or other specific anomalies, whereas the bladder sign does not hold relevance in identifying ventriculomegaly in this context. Understanding the implications of these ultrasound findings is crucial for proper diagnosis and management of suspected neural tube defects and associated complications.