Evaluation of the Antenatal Fetal Brain Metabolites using Proton Magnetic Resonance Spectroscopy / 대한주산의학회잡지

ABSTRACT

OBJECTIVE:The purpose of this study was to compare the sensitivity of proton Magnetic Resonance Spectrography (MRS) for estimating absolute metabolite concentrations and ratio of fetal brains. METHODS:Between September 2005 and August 2006, our study was prospective single center trial and included 39 healthy women (Group 1: fetuses with risk factor of fetal distress or hypoxic damage [n=15], Group 2: fetal CNS anomalies on ultrasound [n=12], Group 3: normal fetuses [n=12]). We quantified resonances for the main proton MRS-detectable brain and calculated metabolite ratios of the three groups. We compared the obtained metabolite levels of the three groups with electronic fetal cardiotocography, Doppler ultrasound examination, Apgar score, and umbilical artery blood gas analysis. RESULTS:Abnormal amniotic fluid, abnormal Doppler studies, and abnormal cardiotocograms were significantly more prevalent in Group 1 compared with those of Group 2 and 3. In Group 1, choline (Cho) levels (7.86+/-3.51mmol/L) were significantly higher than in Group 2 or 3 (p=0.024). The ratios of N-acetylasparate (NAA)/creatinine-phosphocreatine (Cr) and Cho/Cr were increased whereas the ratios of NAA/Cho, lactate (Lac)/Cho, Lac/NAA, and Lac/Cr were decreased; however, there was no statistical significance. In patients who have oligohydramnios and absence of umbilical diastolic flow, choline and N-acetylasparate levels were significantly elevated (p<0.05, p<0.05, respectively). But, MRS metabolites and ratios showed no significant differences for low Apgar scores, umbilical arterial academia, uterine artery notching, maternal blood pressure or abnormal fetal cardiotocograms. CONCLUSION:This study demonstrates the possibility of performing proton MRS to assess the metabolic information of the fetal brain. Further technical progress may be useful of improving the degree of detection of hypoxic changes or an impending hypoxic state for prenatal diagnosis.