Periventricular low intensities on fluid attenuated inversion recovery imaging in the newborn infant: Relationships to chronic white matter lesions

BACKGROUND: Neurological disadvantages due to hypoxic ischemic encephalopathy (HIE) are still very serious problems. In order to support the infant with HIE, it is important to evaluate the severity of the brain injury early. The authors performed a magnetic resonance imaging (MRI) study of the neonatal brain in order to assess the clinical value of periventricular low intensities (PVLI) detected on fluid attenuated inversion recovery (FLAIR) imaging. METHODS: A total of 451 MRI from 167 preterm and 113 term infants were sorted into groups according to the corrected age at the time of scanning. Intensities in the white matter were then divided into five grades according to the severity of the finding on FLAIR imaging. Chronic abnormalities such as periventricular hyperintensities (PVHI) were also analyzed. RESULTS: In early MRI, which was obtained before 2 months corrected age, the incidence of PVLI was 63%, while it was only 3% and 0% in the middle (2-8 months) and the late (8-18 months) scans, respectively. Instead of PVLI, PVHI were commonly observed both on late FLAIR imaging (89%) and late T2-weighted imaging (72%). The severity of the white matter damage diagnosed on early FLAIR imaging had a significant correlation with that of late FLAIR imaging. CONCLUSIONS: F-PVLI on early FLAIR imaging would be a good predictor of chronic white matter damage. FLAIR imaging would be also useful in follow-up of infants because of its high sensitivity to the chronic white matter lesion.