Biphasic time course of brain water ADC observed during the first month of life in term neonates with severe perinatal asphyxia is indicative of poor outcome at 3 years

In severe perinatal asphyxia, the prognostic value of apparent diffusion coefficient (ADC) measurements is still open to question. We hypothesized that temporal and anatomical changes of brain ADC values occurring early after the hypoxic-ischemic insult could predict the outcome at 36 months. To demonstrate this, mean ADC values were calculated for 16 brain structures in 59 term neonates who underwent an MR examination during the first month of life. Neonates were divided into two groups according to their 36-month outcome: unfavorable (death/severe disability) or favorable outcome. ADC values were plotted against age at scan.In neonates with favorable outcomes (n=32), ADC values were constant over the study period. In babies with unfavorable outcomes (n=27), ADCs exhibited two different patterns. In infratentorial structures, ADCs were constant and normal. In supratentorial areas, ADCs followed a biphasic temporal evolution: ADC values were at their lowest at day 2, showed a rapid increase until Days 5-7, and were thereafter similar to those of neonates with favorable outcomes. Using receiver operating characteristic analysis, during the first 3-5 days of life, all neonates with decreased ADC had an unfavorable outcome.These temporal and anatomical changes of ADC values imply that individual prognosis of asphyxiated neonates can only be predicted by measurement of ADC in supratentorial areas within the first 3-5 days of life.