Diffusion-weighted imaging and magnetic resonance proton spectroscopy following preterm birth.

To study the associations between magnetic resonance proton spectroscopy (MRS) data and apparent diffusion coefficients (ADC) from the preterm brain with developmental outcome at 18 months corrected age and clinical variables. A prospective observational cohort study of 67 infants born before 35 weeks gestational age who received both magnetic resonance imaging of the brain between 37 and 44 weeks corrected gestational age and developmental assessment around 18 months corrected age. No relationships were found between ADC values and MRS results or outcome. MRS ratios involving N-acetyl aspartate (NAA) from the posterior white matter were associated with "severe" and "moderate to severe" difficulties, and fine motor scores were significantly lower in participants with a visible lactate doublet in the posterior white matter. The presence of a patent ductus arteriosus (PDA) was the only clinical factor related to NAA ratios. Altered NAA levels in the posterior white matter may reflect subtle white matter injury associated with neuro-developmental difficulties, which may be related to a PDA. Further work is needed to assess the longer-term neuro-developmental implications of these findings, and to study the effect of PDAs on developmental outcome in later childhood/adolescence.