Diffusion tensor imaging of the developing human cerebrum

Abstract

Diffusion tensor imaging (DTI) was performed on 15 fresh spontaneously or therapeutically aborted normal fetuses and five term infants at different gestational ages. Regional cortical fractional anisotropy (FA) values were observed to increase with gestational age (GA) from 15 to 28 weeks, followed by a decrease through 36 weeks. The early increase in the cortical FA value, which has never been reported before, is consistent with neuronal migration from the germinal matrix. A statistically significant inverse correlation between GA and the FA values in the germinal matrix was observed (r = -0.81, P = 0.004). In addition, there was a significant difference in the FA values in the right and left frontal cortices (P = 0.007, sign test), suggesting cortical lateralization during the early stage of development. Our studies suggest that the DTI-estimated anisotropy could be useful in following neuronal migration, cortical maturation, and associated changes in the germinal matrix during early brain development.

Diffusion Tensor MR Imaging in Children with Pantothenate Kinase−Associated Neurodegeneration with Brain Iron Accumulation and Their Siblings

“…These metrics have been widely used to study the microstructural white matter abnormalities in a number of neurologic disorders. Apart from normal white matter, high FA values have also been reported in the developing cerebral cortex, 11,12 brain abscess cavities, 13 and leptomeningeal-cortical regions of patients with meningitis. 14 High FA has been reported in patients with gliomas with chronic hemorrhage, and a metalloanisotropic effect of intracellular iron has been suggested as the reason for this increase.…”

Retrospective measurement of the diffusion tensor eigenvalues from diffusion anisotropy and mean diffusivity in DTI

“…We note that publications that reported tensor anisotropy (rotationally invariant or variant) or mean diffusivity alone were not included in this study (5)(6)(7)(8)11,14,20,21,34,36). The formalism presented in this paper can still be used to interpret literature data using the predicted longitudinal and transverse eigenvalues for cases in which the published reports tabulated the D av and any anisotropy index.…”

“…Equation [11] predicts that the D av normalized eigenvalues are related only to RA n . It also predicts that and Ќ can be determined from D av and RA n (or other anisotropy indices) in the axisymmetric case.…”

“…[2]- [11] along with the assumption of axisymmetry to compute the effective eigenvalues from any tab-ulated anisotropy indices and compared them with the tabulated eigenvalues. Only selected publications (see Results below) that tabulated the mean diffusivity and any rotationally-invariant anisotropy indices along with the tensor eigenvalues were included.…”

Abnormal Developmental Trajectories of White Matter in Autism - The Contribution of MRI

“…Diffusion tensor imaging (DTI) can detect information regarding the size and shape of the compartments, by recording the diffusion of water molecules in more than six directions (Basser et al, 1994;Le Bihan & van Zijl, 2002). DTI was previously shown to be a sensitive method for the study of WM connectivity, integrity, development and pathology (Basser et al, 1994;Dubois et al, 2006;Gupta et al, 2005;Huang et al, 2006;Hüppi & Dubois, 2006;Lebihan, 2006;Neil et al, 2002;Wakana et al, 2003).…”