Proton MR spectroscopy for time evaluation of brain injury in asphyxiated,term neonates

BACKGROUND AND PURPOSE: Neurologic and developmental outcomes of asphyxiate d, term neonates are difficult to predict applying clinical or laboratory c riteria. In this study, we investigated the association of MR spectroscopy (MRS) results with neurodevelopmental status at age 12 months. METHOD: Thirty-one term neonates, who were enrolled in a prospective study of the utility of MR imaging for the determination of neurologic and develo pmental status, underwent single-voxel proton MRS of the basal nuclei and i ntervascular boundary zones. Ratios of lactate, choline, creatine, and N-ac etylaspartate (NAA) peaks were calculated and tested for association with n euromotor scores and Mental Development Index of the Bayley Scores of Infan t Development obtained at age 12 months. RESULTS: Elevated lactate and diminished NAA were the most common findings in infants with neurologic and developmental abnormalities at age 12 months . Although many ratios had statistically significant associations with outc ome (P<.05), the highest significance was obtained with lactate/choline rat ios in the basal nuclei. A false-positive finding was seen in a patient who was born after a 36-week gestation period thigh lactate/choline but normal neurodevelopmental status at 12 months) and in three patients with apparen t watershed injury thigh watershed lactate/choline but normal neurodevelopm ental status at 12 months). A false-negative MRS finding (normal lactate/ch oline but abnormal outcome) was seen in a patient who had an apparent prena tal injury. CONCLUSION: Proton MRS appears to be a useful tool for assessing brain inju ry in neonates who have suffered hypoxia or ischemia. Correlation with gest ational age and imaging findings are essential for proper interpretation of the spectra. Patients with apparent watershed injuries may have normal neu rodevelopmental status at age 12 months.