Diffusion-Weighted Imaging of the Brain in Preterm Infants With Focal and Diffuse White Matter Abnormality

TLDR

Diffuse excessive high signal intensity (DEHSI) is the most common MRI finding in term‑equivalent preterm infants, yet its biological significance remains unclear. The study aimed to determine whether DEHSI reflects normal or abnormal white matter by comparing diffusion characteristics with normal and overtly damaged infants. Using 1.5‑Tesla diffusion‑weighted MRI, 50 preterm infants were classified into normal, DEHSI, or overt pathology groups, and ADC values were measured in frontal, central, and posterior white matter and compared by ANOVA with Bonferroni correction. ADC values were significantly higher in both DEHSI and overt pathology groups compared to normal, with no difference between DEHSI and overt pathology, indicating that DEHSI represents diffuse white matter abnormality.

Abstract

The most common finding on magnetic resonance imaging (MRI) of the brain in preterm infants at term-equivalent age is diffuse excessive high signal intensity (DEHSI) in the white matter. It is unclear whether DEHSI represents a biological abnormality. This study used diffusion-weighted imaging (DWI) to compare apparent diffusion coefficient (ADC) values in DEHSI with infants with normal imaging and those with overt brain damage to determine whether DEHSI shows the diffusion characteristics of normal or abnormal tissue.MRI, using conventional and diffusion-weighted imaging (DWI), was performed in 50 preterm infants at term-equivalent age using a 1.5 Tesla MR scanner. The infants were divided into 3 groups on the basis of their MRI results: 1) normal white matter, 2) DEHSI, or 3) overt white matter pathology. ADC values were measured in the frontal, central, and posterior white matter at the level of the centrum semiovale. ADC values in the 3 groups of preterm infants were compared using a 1-way analysis of variance with a Bonferroni test for multiple comparisons.ADC values were significantly higher in infants with DEHSI and infants with overt white matter pathology than in infants with normal white matter. There was no significant difference between ADC values in infants with DEHSI and those with overt white matter pathology.This study provides objective evidence that DEHSI represents diffuse white matter abnormality.