TY - JOUR
T1 - A new approach to structural integrity assessment based on axial and radial diffusivities
AU - Wheeler-Kingshott, Claudia A M
AU - Ciccarelli, Olga
AU - Schneider, Torben
AU - Alexander, Daniel C.
AU - Cercignani, Mara
PY - 2012/10
Y1 - 2012/10
N2 - This study describes a method for performing diffusivity measures along and across a specific direction, derived from white matter in healthy controls. The diffusion tensor (DT) assigns a principal eigenvector (v1) and eigenvalue (axial diffusivity, dax) to each voxel. The average of the second and third eigenvalues is the radial diffusivity, drad•v1 may be affected by pathology, therefore when comparing d ax and drad in patients one has to consider the direction of the measurement and underlying anatomy. Here we created a representative super-DT dataset, DT rref, whose eigenvector, v1,ref, was considered the most likely direction of diffusivity per voxel. We defined the projected axial diffusivity, dp-ax, as the projection of individual DTs along v1,ref and the projected radial diffusivity, dp-rad, as the average of the projections along the second and third eigenvectors of DTref. The projected diffusivities are promising new parameters for studying white matter pathology.
AB - This study describes a method for performing diffusivity measures along and across a specific direction, derived from white matter in healthy controls. The diffusion tensor (DT) assigns a principal eigenvector (v1) and eigenvalue (axial diffusivity, dax) to each voxel. The average of the second and third eigenvalues is the radial diffusivity, drad•v1 may be affected by pathology, therefore when comparing d ax and drad in patients one has to consider the direction of the measurement and underlying anatomy. Here we created a representative super-DT dataset, DT rref, whose eigenvector, v1,ref, was considered the most likely direction of diffusivity per voxel. We defined the projected axial diffusivity, dp-ax, as the projection of individual DTs along v1,ref and the projected radial diffusivity, dp-rad, as the average of the projections along the second and third eigenvectors of DTref. The projected diffusivities are promising new parameters for studying white matter pathology.
KW - Axial diffusivity
KW - Diffusion tensor
KW - DTI
KW - Eigenvalues
KW - Radial diffusivity
KW - Template
UR - http://www.scopus.com/inward/record.url?scp=84870193140&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84870193140&partnerID=8YFLogxK
M3 - Article
C2 - 23158579
AN - SCOPUS:84870193140
VL - 27
SP - 85
EP - 90
JO - Functional Neurology
JF - Functional Neurology
SN - 0393-5264
IS - 2
ER -