Yi Li BS, Presenter: Nothing to Disclose

Deborah Levine MD, Abstract Co-Author: Consultant, SafeMed Inc, San Diego, CA Editor with royalties, UpToDate, Inc Editor with royalties, Amirsys, Inc

Judy Ann Estroff MD, Abstract Co-Author: Nothing to Disclose

Tina Young Poussaint MD, Abstract Co-Author: Nothing to Disclose

Caroline Diana Robson MBChB, Abstract Co-Author: Consultant, Amirsys, Inc

Henry A. Feldman PhD, Abstract Co-Author: Nothing to Disclose

Tejas S. Mehta MD, MPH, Abstract Co-Author: Nothing to Disclose

Richard L. Robertson MD, Abstract Co-Author: Nothing to Disclose

Carol Elizabeth Barnewolt MD, Abstract Co-Author: Nothing to Disclose

To assess postnatal outcomes of fetuses with agenesis or dysgenesis of the corpus callosum (ACC) after referral for ventriculomegaly (VM).

In a prospective IRB-approved study from 7/2003 to 5/2009, 433 fetuses referred for VM were imaged with US and MRI. Five radiologists independently recorded ventricular diameter, ventricular configuration, degree of visualization of the corpus callosum, and CNS abnormalities, with final descriptions decided by consensus. Postnatal outcomes were obtained.

58 fetuses had callosal abnormalities and 224 had isolated VM. Atrial diameter was 8-42 mm (mean 14.4 mm) in ACC and 9-19 mm (mean 11.5 mm) in isolated VM fetuses (p<0.0001). Frontal horn diameters were 1-22 mm (mean 4.4 mm) and 2-15 mm (mean 4.9 mm), respectively (p<0.0001). Pre-conference kappa for ACC among US readers was 0.86, among MR readers was 0.89, and among all readers was .87. 5/25 fetuses with isolated ACC by US had additional CNS abnormalities on MR. Fetuses with ACC were more likely to be described as having colpocephaly (58% by US, 81% by MR) compared to fetuses with isolated VM (0% by MR/US, p<0.00001). In fetuses with ACC, 33/58 (57%) had complete nonvisualization of the corpus callosum, and 15/58 (26%) had partial nonvisualization. In fetuses with isolated VM, these percentages were 0/224 (0%) and 7/224 (3%), respectively. 2/23 (9%) fetuses with isolated ACC, 13/35 (37%) fetuses with ACC and other CNS abnormalities, and 21/224 (9%) with isolated VM either underwent termination or died in utero or in the neonatal period. In 8/23 fetuses with isolated ACC on prenatal imaging, additional CNS abnormalities were present postnatally. Neurodevelopmental outcome was normal in 1/43 (2%) surviving children with ACC (the normal infant had isolated ACC), and 62/208 (30%) surviving children with isolated VM (p<0.00001). Degree of callosal visualization was not as important as presence of associated CNS abnormalities in predicting birth and developmental outcomes.

There is high inter-rater agreement in prenatal diagnosis of ACC. MR is more sensitive than US in diagnosis of ACC and in identifying CNS anomalies associated with ACC. Information regarding diagnosis and associated abnormalities influences pregnancy management.

Knowledge of prenatal findings associated with ACC will aid in diagnosis, and knowledge of postnatal outcomes will aid in pregnancy counseling.

Li, Y, Levine, D, Estroff, J, Poussaint, T, Robson, C, Feldman, H, Mehta, T, Robertson, R, Barnewolt, C, Postnatal Outcome after Magnetic Resonance and Ultrasound Diagnosis of Agenesis or Dysgenesis of the Corpus Callosum in Fetuses Referred for Ventriculomegaly.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9001856.html