Diffusion-weighted magnetic resonance imaging in infants with periventricular leukomalacia.

Objective: We examined diffusion-weighted magnetic resonance imaging (DWI) findings in periventricular leukomalacia (PVL) and then evaluated the relationship between the mean apparent diffusion coefficient (ADC) values and the region and severity of PVL.

Methods: Between April 2006 and July 2007, 98 infants at gestational ages between 27 and 33 weeks were enrolled in the study. DWI was performed during the first week of life when electroencephalography indicated PVL. The mean ADC values were evaluated using regions of interest drawn manually in the periventricular white matter, posterior limbs of internal capsules (PLICs), and various regions of the brain.

Results: DWI was performed in three of four infants with PVL indicated on electroencephalography. All had decreased diffusivity in the anterior to posterior white matter despite a predominance in the posterior white matter. DWI abnormalities were also observed in the corpus callosum and PLICs and were more broadly distributed in the brain than those detected by later conventional MRI. In the PLICs, the changes in the ADC values were correlated with the severity of the PVL.

Conclusion: The DWI findings provided additional information regarding PVL. Among the findings, the association of the presence of decreased diffusivity in the corticospinal tract with later motor impairment was the most interesting.