Clinical Implications of MR Imaging Findings in the White Matter in Very Preterm Infants: A 2-year Follow-up Study

Purpose: To explore the association between diffuse excessive high signal intensity (DEHSI), punctate white matter (WM) lesions, and ventricular dilatation around term-equivalent age (TEA) and at clinical follow-up at 2 years in very pre-term infants and the effect on neurodevelopment. Materials and Methods: Ethical approval for this prospective study was given by the institutional review board, and informed parental consent was obtained. An unselected cohort of 110 preterm infants (gestational age, < 32 weeks) was imaged around or alter TEA. Clinical follow-up was performed at a corrected age of 2 years and consisted of a neurologic examination and a mental and developmental assessment (Bayley Scales of Infant Development). Univariate analyses and logistic and linear regression were performed to examine the relationships between variables. Results: DEHSI was found in 58 of 65 (89%) infants imaged around TEA. DEHSI was never detected in infants imaged after postmenstrual age of 50 weeks and showed no association with neurodevelopmental outcome. Punctate WM lesions and ventricular dilatation were significantly associated with mental (P = .02 for punctate WM lesions) and psychomotor developmental delay (P < .001 and P = .03, respectively), motor delay (P = .002 and P = .02, respectively), and cerebral palsy (P = .01 and P = .03, respectively). Conclusion: Because of its high incidence in preterm infants around TEA, its absence after a postmenstrual age of 50 weeks, and its association with normal neurologic outcome at a corrected age of 2 years, DEHSI should not be considered pant of the spectrum of WM injury, but rather a prematurity-related developmental phenomenon. (C) RSNA, 2011