Rosana Carvalho Silva MD, Presenter: Nothing to Disclose

Patricia S. Oliveira MD, Abstract Co-Author: Nothing to Disclose

Vasilios Charilaos Bobotis MD, Abstract Co-Author: Nothing to Disclose

Jacob Szejnfeld MD, Abstract Co-Author: Nothing to Disclose

Karina Krajden Haratz, Abstract Co-Author: Nothing to Disclose

Cynthia Maria Soares Alves DPhil, Abstract Co-Author: Nothing to Disclose

Franklin de Freitas Tertulino MD, Abstract Co-Author: Nothing to Disclose

Samia Yamashita, Abstract Co-Author: Nothing to Disclose

Sergio A. Ajzen MD, PhD, Abstract Co-Author: Nothing to Disclose

Luciana Satiro Timbo MD, Abstract Co-Author: Nothing to Disclose

Mild ventriculomegaly (VM) is the most common fetal cerebral anomaly detected by routine prenatal sonographic scans. VM is very often the “tip of the iceberg”, being the first sign of a more complex central nervous system (CNS) malformation that may be undetected, especially related to the midline. The aim of this study was to assess the corpus callosum of fetuses with VM using ultrafast MRI.

In this retrospective study we have selected 54 fetuses with mild ventriculomegaly (atrium width of 10–15 mm) diagnosed at prenatal sonography, between 2008 and 2011. Mean gestational age was 27 weeks. These fetuses were submitted to MR study (1,5T system with rapid acquisition of Half-Fourier T2-weighted sequences along the three orthogonal planes) and the following parameters were analyzed: atrium width and morphology of the lateral ventricles, morphology and biometry of the corpus callosum, signal intensity alterations of the brain tissue, pattern of sulci and gyri and other CNS malformations.

We have found bilateral VM in 40 fetuses and unilateral VM in 14. Mean transverse diameter of the lateral ventricles was 12 mm. The morphologic analysis showed 9 fetuses with normal configuration, 26 fetuses with parallel configuration of the frontal horns and 19 with colpocephaly. 31 fetuses presented corpus callosum agenesis (12 complete and 19 partial agenesis). Isolated agenesis was seen in 18 fetuses. Associated abnormalities were seen in 13 fetuses (Dandy-Walker, Chiari malformation type II, holoprosencephaly, neuronal migrational disturbances) and its identification is vital for prognostic determination, since the severity of clinical presentation is more related to associated malformations than with corpus callosum agenesis itself. 

Ventricular dilatation is a reliable tool for the diagnosis of corpus callosum agenesis. Also, mild ventricular dilatation may be a signal of hidden abnormalities, since 25% of the fetuses with mild VM had severe associated conditions. MR proved to be a very useful modality for the identification of corpus callosum agenesis and associated fetuses’ malformations.

Prenatal diagnosis of fetuses with mild VM and associated malformations is crucial for pregnancy management and parents information regarding neurological development of their child.

Silva, R, Oliveira, P, Bobotis, V, Szejnfeld, J, Haratz, K, Alves, C, Tertulino, F, Yamashita, S, Ajzen, S, Timbo, L, Behind the Ventriculomegaly: MRI Imaging for the Detection of Callosal Anomalies in Fetuses with Mild Ventricular Dilations.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034346.html