Background: Periventricular white matter (WM) hyperechogenicity that does not evolve into cystic lesion(s) is frequently encountered on cranial ultrasonography (CUS) of preterm infants. Subjective interpretation of its presence, however, is challenging. Quantitative analysis of echogenicity is a novel technique that may overcome ambiguities in CUS interpretation. Its association to maturation and neurodevelopment remains undefined.
Objectives: To determine the relationship between quantitative WM echogenicity to postnatal and postconceptional age and to neuromotor development at term equivalent.
Methods: We measured mean pixel brightness intensity at the frontoparietal and parietooccipital WM, choroid plexus and calvarium bone on sequential neonatal CUS scans. The relative echogenicity (RE) was derived by dividing the mean WM echogenicity to that of the choroid plexus (RECP) or bone (REBN). The Lacey Assessment of the Preterm Infants was administered before discharge.
Results: 58 preterm infants (mean gestational age 30.6±2.3 weeks and mean birth weight 1211.9±224.7 g) were included. The RECP of the frontoparietal WM decreased significantly with advancing postnatal and postconceptional age (r=0.4, p <.0001). The REBN of the frontoparietal and parietooccipital WM during intermediate and late pre-discharge CUS studies, respectively, were significantly associated with neuromotor status at term (p <.05). The RECP and REBN measured during the first week of life were not associated with neuromotor status at term.
Conclusions: Quantitative measurements of the RE of periventricular WM are feasible in neonatal CUSs of premature infants and may reflect microstructural developmental changes. An optimal echogenicity quantification technique and its correlation to long-term outcome remains to be determined
