Diffusion tensor imaging: A biomarker of outcome in Krabbe's disease.

Krabbe's disease is a rare autosomal recessive lysosomal disorder resulting from deficiency of β-galactocerebrosidase that affects primarily cerebral white matter and peripheral nerves. Conventional magnetic resonance imaging (MRI) is sensitive to changes in white matter myelination, but its assessment is based purely on qualitative, visual inspection, and it is subject to interobserver variability and open to reader bias. Diffusion tensor imaging (DTI) is an advanced MRI technique that provides quantitative information about the microscopic structural organization of the white matter and changes in cell density and myelination, and it is a suitable MRI tool for studying Krabbe's disease. This Review discusses the available studies on the application of quantitative DTI analysis to assess white matter changes in patients with Krabbe's disease. Quantitative analysis of DTI scalars, especially radial diffusivity and fractional anisotropy, has been shown to be a sensitive in vivo biomarker of white matter microstructural damage in Krabbe's disease, to detect early white matter injury in asymptomatic neonates with Krabbe's disease, to predict motor and cognitive functions after hematopoietic stem cell transplantation (HSCT), and to serve as a measurement for monitoring effects of HSCT on white matter development in Krabbe's disease.