Chemical shift imaging and localised magnetic resonance spectroscopy in full-term asphyxiated neonates

Background: Diagnosis of brain lesions after birth anoxia-ischemia is essential for appropriate management. Clinical evaluation is not sufficient. MRI has been proven to provide useful information. Objective: To compare abnormalities observed with MRI, including diffusion-weighted imaging (DWI), localised magnetic resonance spectroscopy (MRS) and chemical shift imaging (CSI) and correlate these findings with the clinical outcome. Materials and methods: Fourteen full-term neonates with birth asphyxia were studied. MRI, MRS and CSI were performed within the first 4 days of life. Results: Lesions observed with DWI were correlated with outcome, but the apparent diffusion coefficient (ADC) did improve diagnostic confidence. The mean value of Lac/Cr for the neonates with a favourable outcome was statically lower than for those who died (0.22 vs 1.04; P = 0.01). The same results were observed for the Lac/NAA ratio (0.21 vs 1.23; P = 0.01). Data obtained with localised MRS and CSI were correlated for the ratio N-acetyl-aspartate/choline, but not for the other metabolites. No correlation was found between the ADC values and the metabolite ratios. Conclusions: Combination of these techniques could be helpful in our understanding of the physiopathological events occurring in neonates with asphyxia.