BACKGROUND AND PURPOSE: WM injury is associated with different disabilities that children born prematurely may experience during their lives. The aim of this study was to use TBSS to test the hypothesis that WM microstructure at TEA in preterm infants is correlated with cognitive and motor outcome at 2-year corrected age.

The relationship between MR patterns of brain damage and type or timing of perinatal hypoxia-ischemia was studied. MR images of 104 children with evidence of bilateral posthypoxic-ischemic brain damage and neonatal records were reviewed. Three different MR patterns were found. Periventricular leukomalacia occurred in 73 children, in 82% after a history of subacute or chronic hypoxia-ischemia, in 71% after preterm birth. Predominant lesions of basal ganglia and thalamus occurred in 21 children, in 95% preceded by acute profound asphyxia, in 85% after term birth. Multicystic encephalopathy occurred in 10 infants, in 70% preceded by mild signs of hypoxia-ischemia, followed by an unexpectedly severe encephalopathy, in 60% after term birth. Statistical analysis showed that the patterns of injury were primarily related to the type of hypoxia-ischemia. We conclude that the type of hypoxia-ischemia, rather than the postconceptional age at occurrence determines the pattern of brain injury.

.4 to 662)). Conclusions-In the cohort studied, 50% of the infants with c-PVL had a more localised form (grade II). In grade II PVL, the cysts developed beyond the first month of life in more than half of the cases and were often no longer visible, on US, at 40 weeks PMA. In order not to miss this diagnosis, sequential US should also be performed beyond the first month of life. Mild ventriculomegaly noted at term can sometimes be due to grade II c-PVL. Cerebral palsy was slightly less common and tended to be less severe in infants with grade II PVL than in those with grade III PVL.

During a period of 30 months, 504 infants of 34 weeks gestation or less were enrolled in a prospective cranial ultrasound study. Ninety-two (18.4%) infants developed different degrees of periventricular leukomalacia (PVL), being transient periventricular echogenicities (PVE) in 75, localised cystic lesions in 7 and extensive cysts in 10. Eight of 75 (10.6%) infants with PVE, 4 of the 6 (66.6%) survivors with localised cysts and all 8 survivors with extensive cysts developed cerebral palsy in infancy and MRI studies could be performed in 15 of these 20 infants between 11 and 32 months of age. Neurological sequelae were most severe among the infants with extensive cysts and none were able to walk, while 6 of the 12 who developed cerebral palsy following either PVE or localised cysts had learned to walk independently. There appeared to be a good correlation between the degree of PVL, diagnosed using ultrasound, and the extent of MRI changes noted in infancy. Ventricular enlargement and delay in myelination were more common in infants with cystic lesions and periventricular hyperintensity (PVHI) was present in all infants, but most extensive in the cases with extensive cysts. MRI performed later in infancy may, even in the absence of neonatal cranial ultrasound, provide information about both the presence as well as the degree of leukomalacia, which the child may have suffered in the neonatal or antenatal period.

BACKGROUND AND PURPOSE:Signal-intensity abnormalities in the PLIC and thinning of the CC are often seen in preterm infants and associated with poor outcome. DTI is able to detect subtle abnormalities. We used FT to select bundles of interest (CC and PLIC) to acquire additional information on the WMI.