Frequently encountered cranial ultrasound features in the white matter of preterm infants: Correlation with MRI

BackgroundBilateral symmetrical echogenic and echolucent areas in the white matter are frequently seen on the cranial ultrasound scans of apparently well preterm infants without overt pathology.AimTo determine whether these features reflect maturational processes as seen on MRI.MethodsPreterm and term-born infants without overt pathology on contemporaneous brain ultrasound and MRI were studied. Ultrasound scans were compared with T2-weighted MRI to identify MR correlates for the bilateral and symmetrical echogenic and echolucent phenomena in the white matter seen on ultrasound.ResultsForty-four sets of scans (26 preterm, 8 term-born infants) were assessed. Echogenic features were better and more frequently seen on early ultrasound as compared to nearer term age. Echogenic blushes in the white matter correlated well with high signal intensity areas and echogenic lines with low signal intensity lines on MRI. Echolucent areas correlated with the site of the internal capsule and the myelinated posterior pons. The subplate was not reliably identified.ConclusionMany echogenic and echolucent features in the white matter of well preterm and some term-born infants correlated well with areas of differing signal intensity on MRI. They most likely reflect normal maturational processes but the echogenic hemispheric features may represent delayed or abnormal maturation.