Fetal brain infections.

INTRODUCTION: Congenital infections can cause severe brain damage. As a result, it is very important to identify them early in their course so that treatment can be administered to the mother, if possible. The role of imaging is to determine the presence, if any, and the extent of brain damage in the infected fetus. Although MRI is most commonly used as an adjunct to sonography, when clinical suspicion is high in the setting of a normal ultrasound or to better define abnormalities detected by ultrasound, MRI is routinely used in toxoplasmosis seroconversion to definitively rule out brain lesions, even when the ultrasound scan is considered normal. MRI is also used serially throughout the pregnancy to check for the development of brain abnormalities; medical treatment results in excellent clinical outcome if the brain is normal. DISCUSSION: This article describes the indications, techniques, and findings that will allow proper use of fetal MRI in the setting of congenital infections.