Resumo

MAYOBRE, Finita et al. Utilidad de la espectroscopia por resonancia magnética en fetos con resistencias arteriales normales y resistencias arteriales elevadas. Rev Obstet Ginecol Venez [online]. 2011, vol.71, n.2, pp.98-111. ISSN 0048-7732.

Objective: To determine if proton magnetic resonance spectroscopy could be used to evaluate fetal brain development with normal and high arterial resistances, and to predict neurological damage. Setting: Unidad de Perinatología del Hospital Universitario de Caracas Methods: Umbilical cord and brain median artery at M₂ segment level arterial resistances were measured to sixty pregnant women with gestation age of 26 to 36 weeks. Thirty had normal arterial resistances (control fetuses) and thirty had high arterial resistances. Body and cerebral axial, coronal and sagittal images were obtained from all fetuses. Cerebral spectroscopy was performed with short and medium-length eco time. Single voxel was located in the basal ganglia. N-acetylaspartate/creatine, N-acetylaspartate/choline, choline/creatine, choline/N-acetylaspartate, mio-inositol/N-acetilaspartate and mio-inositol/creatine ratios were analyzed. Absolute frequencies, percentages, median, standard deviations and Fisher test were used for statistical analysis. Results: Fetuses with high umbilical cord arterial resistances were significant higher than the obtained for control fetuses. Anatomical images were normal in all fetuses. N-acetylaspartate/choline and N-acetylaspartate/creatine increased and choline/N-acetylaspartate, myo-inositol/N-acetylaspartate and myo-inositol/creatine decreased with gestational age in control fetuses. Large variability resulted on metabolite ratios of fetuses with high umbilical cord arterial resistances. No significant differences on metabolites ratios were found between control fetuses and fetuses with high umbilical cord arterial resistances. Lactate was detected in 68 % of brain fetuses with high umbilical cord arterial resistances. Conclusion: Proton magnetic resonance spectroscopy is able to evaluate fetal brain development and brain lactate, which is indicative of hypoxia, might predict neurological damage.

Palavras-chave : Fetus brain proton magnetic resonance spectroscopy; Brain lactate; Fetus eco-Doppler; Fetus magnetic resonance imaging; Arterial resistances in fetuses; Arterial resistances in umbilical cord.