Cranial sonography in neonates almost always reveals a hyperechoic "blush" just posterior and superior to the ventricular trigones on parasagittal views. This normal increased echogenicity resembles fine brush strokes. It is probably caused by the interface of numerous parallel fibers that are nearly perpendicular to the longitudinal axis of a sonographic beam passing through the anterior fontanelle. The same echogenicity is not seen on sonograms obtained through the posterior fontanelle because with that angulation the long axis of the sonographic beam and the fiber tracts are nearly parallel. Sonographic-pathologic correlation in 28 autopsy cases showed that abnormal, dense, globular, coarse, peritrigonal echogenicity was due to periventricular leukomalacia with hemorrhage. Cases with nonhemorrhagic periventricular leukomalacia or perinatal telencephalic leukoencephalopathy demonstrated the normal peritrigonal hyperechogenicity.