The aim of this study was to define the risk ratios of the late-infancy magnetic resonance imaging pattern for long-term outcome in term infants with perinatal asphyxia. We evaluated 65 term infants with perinatal asphyxia and performed magnetic resonance imaging examinations between 4-12 months of age. Magnetic resonance imaging scans were classified as follows: (1) periventricular leukomalacia in 21 (32%) infants, (2) marked cortical atrophy in 17 (26%) infants, (3) multicystic encephalomalacia in 10 (15%) infants, (4) deep gray matter involvement in 8 (12%) infants, (5) focal cortical involvement in 6 (9%) infants, (6) myelination delay in 3 (5%) infants. The overall outcome was favorable in 19 (29%) of 65 infants. Infants with diffuse cortical involvement (multicystic encephalomalacia and marked cortical atrophy) are four times (odds ratio: 4.4 and 4.1 respectively) more likely to attain the unfavorable outcome than the infants with other patterns of magnetic resonance imaging. Infants with focal cortical involvement had relatively favorable outcome in 60% of the cases. In conclusion, it appears that the overall outcome of infants with perinatal asphyxia correlated well with the magnetic resonance imaging patterns obtained between 4 and 12 months of age. (C) 2004 by Elsevier Inc. All rights reserved.