EARLY PATTERN-RECOGNITION IN SEVERE PERINATAL ASPHYXIA - A PROSPECTIVE MRI STUDY

On the basis of MRI examinations in 88 neonates and infants with perinatal asphyxia, we defined 6 different patterns on T2-weighted images: pattern A - scattered hyperintensity of both hemispheres of the telencephalon with blurred border zones between cortex and white matter, indicating diffuse brain injury; pattern B - parasagittal hyperintensity extending into the corona radiata, corresponding to the watershed zones; pattern C - hyper- and hypointense lesions in thalamus and basal ganglia, which relate to haemorrhagic necrosis or iron deposition i n these areas; pattern D - periventricular hyperintensity, mainly along the lateral ventricles, i.e. periventricular leukomalacia (PVL), originating from the matrix zone; pattern E - small multifocal lesions varying from hyper- to hypointense, interpreted as necrosis and haemorrhage; pattern F - periventricular centrifugal hypointense stripes in the centrum semiovale and deep white matter of the frontal and occipital lobes. Contrast was effectively inverted on T1-weighted images. Patterns A, B and C were found in 17 %, 25 % and 37 % of patients, and patterns D, E and F in 19 %,17 % and 35 %, respectively. In 49 patients a combination of patterns was observed, but 30% of the initial images were normal. At follow-up, persistent abnormalities were seen in all children with patterns A and D, but in only 52 % of those with pattern C. Myelination was retarded most often in patients with diffuse brain injury and PVL (patterns A and D).