Influence of moderate hyperbilirubinemia in infants' brain: Quantitative susceptibility mapping and 1 H-MRS study

Ru Zhao ¹ JiaJia Xu ¹ Lianzi Su ¹ YanQi Shan ¹ Hao Zhan ¹ Qun Pei ¹ LongSheng Wang ^1* Liwei Zou ^1,2*

• ¹ The Second Affiliated Hospital of Anhui Medical University, Hefei, China
• ² MOE Key Laboratory of Population Health Across Life Cycle and Anhui Provincial Key Laboratory of Population Health and Aristogenics, Hefei, China

The effects of moderate neonatal hyperbilirubinemia (NHB) keep unknown. The aim of this work was to investigate whether moderate NHB has an impact on infants' brain and the relationship between brain magnetic susceptibility, brain metabolites and biochemical tests in moderate NHB by quantitative susceptibility mapping (QSM) and magnetic resonance spectroscopy (MRS).Twenty-eight term babies with moderate level of blood bilirubin were enrolled in the NHB group, and 16 term infants were collected as the control group. All patients underwent biochemical tests, 1H-MRS, and QSM examinations. Biochemical test results (e.g. direct bilirubin (DBiL)), metabolite ratios (e.g.Glycerophosphocholine (GPC)), and susceptibility values were collected. The Mann Whitney U test was used to assess the differences between NHB and control groups. Partial least square correlation analyses (PLSC) were performed to analyze the correlations between biochemical results with metabolite ratios, and susceptibility values.The Mann Whitney U test depicted that significant differences were observed in the biochemical results, susceptibility value of left putamen, and absolute concentration of GPC between the NHB and controls. No significant differences were found in the metabolite ratios between the two groups. PLSC analysis demonstrated that ratios of myo-Inositol (Ins), N-Acetylaspartate (NAA), and GPC relative to Cr have robust correlation with DBiL in NHB group. Furthermore, increasing susceptibility values of putamen, globus pallidus, caudate nucleus, and thalamus had moderate correlation with decreasing DBiL and increasing TSH concentrations in the NHB group.This study demonstrated that moderate hyperbilirubinemia could induce metabolic and susceptibility changes in infants' brain (e.g., decreasing susceptibility values and metabolites values) and these changes have correlation with biochemical studies.