Diffusion tensor imaging of periventricular leukomalacia – Initial experience

Abstract

Aim of the study: To investigate the role of MR diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) in the assessment of altered major white matter fibers in preterm infants and children with PVL. Patients and methods: We used diffusion tensor imaging to evaluate the major white matter tract fibers in 15 children with periventricular leukomalacia in correlation with cognitive and motor disability. Mean age of the patients was 28.5 months (range: 9–84 months). 5 normal control children were recruited (mean age: 21.4, range: 11–60 months). MR imaging was obtained by using a 1.5-T, whole-body scanner. DTI was acquired after the routine sequences. Then, data post-processing and fiber-tracking method was applied. Results: This study demonstrated the existence of the WM tract injury in PVL patients using the DTI tractography approach in correlation with neurodevelopmental delay in patients with various degrees of cognitive and motor impairment. Compared with the normal control group, the following abnormalities were detected on qualitative analysis of the white matter tracts. Corticospinal tracts: Decreased volume and cross-sectional area on the affected side. Ascending sensorimotor tracts: Thinning of sensory fiber tracts and posterior thalamic radiations. Commissural and association tracts: Significant damage of the callosal fibers was reported in cases with partial agenesis of the corpus callosum. Conclusion: DTI proved to be a promising noninvasive method for assessing the severity of white matter tract injury in patients with PVL. This is owing to the capability of fiber-tracking techniques to provide more information for understanding the pathophysiologic features of sensorimotor and cognitive disability associated with PVL. This will allow for the early intervention and initiation of rehabilitation programs aiming for minimizing the associated neurological deficit.

Keywords

• DTI: diffusion-tensor imaging
• DTT: diffusion tensor tractography (DTT)
• PVL: periventricular leukomalacia
• CP: cerebral palsy