Metabolic and structural changes detected by magnetic resonance in IUGR fetuses

V. Zamfirescu, R. Vladareanu, S. Vladareanu, C. Badiu

Rezumat: Intrauterine growth restriction (IUGR) due to placental insufficiency affects 5-10% of all pregnancies and induces cognitive disorders in a substantial proportion of all newborns and is associated with a high risk of abnormal neurodevelopment. Magnetic resonance imaging (MRI) studies have consistently demonstrated brain structural changes on IUGR fetuses: decreased volume in gray matter (GM) and hippocampus; major delays in cortical development have been reported in neonates; reduced GM volumes and decreased fractal dimension of both GM and white matter in infants. MR spectroscopy (MRS) has become a powerful diagnostic tool in the detection of specific brain abnormalities, such as hypoxic-ischemic encephalopathy. Therefore, it is of great interest to explore the possibilities of proton MR spectroscopy as a tool to examine the human fetal brain in situ. This is a technique with which the chemical composition of in vivo tissue can be assessed noninvasively. It has been reported that impaired fetal brain development associated with ventriculomegaly, intrauterine growth restriction (IUGR), and small for gestational age fetuses can be shown by MRS signal changes. Normative values for the levels of the fetal brain metabolites, Inositol, Choline, Creatine, N-Acetylaspartate and their ratios are available and can be used as references to examine changes in MRS spectra due to pathological conditions of the fetal brain, for example, neuronal damage due to hypoxia. MRI has the potential to become an important tool in studying normal and abnormal fetal brain development.
Cuvinte cheie: intauterine growth restriction, fetus, proton spectroscopy, brain metabolites.