Investigators from Okazaki City Hospital, and other centers in Japan retrospectively evaluated the clinical features, ultrasonography, and EEG findings in 22 preterm infants with PVHI and 49 with PVL. Gestational age and birth weight were significantly lower in infants with PVHI than those with PVL. EEGs performed serially beginning immediately after birth were normal in the majority of infants with PVHI on days 1- 2. EEG abnormalities appeared after ultrasonography abnormalities. The majority of infants with PVL (28 (85%) of 33) showed acute-stage EEG abnormalities on days 1-2. Acute-stage EEG abnormalities were more frequent in infants with PVHI than in those with PVL on days 5-14 (p < 0.05). The rate of infants with acute-stage EEG abnormalities decreased with age, whereas the rate of infants with chronic-stage EEG abnormalities increased with age. Normal EEG before ultrasonography abnormalities was more common in infants with PVHI than in those with PVL. PVHI causes mostly postnatal injury, whereas PVL is presumed to cause mostly pre- or perinatal injury. 
COMMENTARY. PVHI and PVL are well-defined white matter injuries in preterm infants that are accompanied by neurological sequelae. Cranial ultrasonography (US) in infants with PVHI shows periventricular intraparenchymal echodensity (IPE) at 1-3 days after birth, whereas cystic changes in deep white matter are seen in infants with cystic PVL at 1-3 weeks.
Ultrasound vs MRI for detecting intracranial hemorrhage in preterm neonates
Investigators at Johns Hopkins Hospital studied 12 premature neonates with a mean gestational age of 32 weeks, comparing US and MRI for detection of grade I-III germinal matrix hemorrhage (GMH) and PVHI. US had high sensitivity (100%) and specificity (93%) in detecting grade III GMH but poor sensitivity (0%) in detection of intraventricular hemorrhage (grade II GMH). US is first line of imaging for brain injury in the evaluation of premature neonates with suspected intracranial hemorrhage, but usefulness of MRI and susceptibility-weighted imaging for predicting long-term neurological outcome remains to be determined .