Diffusion tensor imaging and Tract-Based Spatial Statistics in Alzheimer's disease and mild cognitive impairment

Perspective on future role of biological markers in clinical therapy trials of Alzheimer's disease: A long-range point of view beyond 2020

“…Increased MD and decreased FA values have been reported in AD and MCI in parietal and temporal areas, including the hippocampal region, suggesting unspecific bundle degeneration [191,192]. Abnormal DT derived indices have also been demonstrated in frontal region, and specifically in the cingulum posterior, corpus callosum, fasciculus longitudinalis superior, and fasciculus uncinatus [193][194][195].…”

Individual Classification of Mild Cognitive Impairment Subtypes by Support Vector Machine Analysis of White Matter DTI

“…Most investigations included only 1 (not further specified) MCI group, [23][24][25] or only the sd-aMCI subtype, [26][27][28][29] or a mix of several subtypes, with the aim of discriminating stable versus progressive MCI. 30 Only 3 recent contributions compared DTI patterns in aMCI versus non-MCI.…”

“…First, a group-level analysis using TBSS, 22 an improved voxel-based technique with respect to spatial normalization, was performed to identify regions with altered white matter structure between groups. As discussed above, recent investigations implementing this technique in the domain of MCI 23,24,28 documented the presence of reduced FA primarily in white matter tracts with homogeneously oriented fibers (ie, genu or splenium of the corpus callosum, superior longitudinal fasciculus, cingulus) and, more rarely, in frontal, parietal, and temporal white matter. However, other studies led to negative data challenging this point of view.…”

“…Applying DTI analyses with voxelwise TBSS, 22 an increasing number of contributions described the damage of long interhemispheric and intrahemispheric white matter tracts with homogeneously oriented fibers (ie, genu or splenium of the corpus callosum, superior longitudinal fasciculus, cingulus) and, more rarely, in frontal, parietal, and temporal white matter in patients with MCI compared with healthy controls. [23][24][25][26][27][28][29][30][31] The biologic relevance of the description of MCI subtypes is still a challenging issue. In particular, it is unclear whether the neuropsychologic definition of these subtypes corresponds to distinct patterns of brain compromise.…”

White Matter Alteration in Idiopathic Normal Pressure Hydrocephalus: Tract-Based Spatial Statistics Study

“…In TBSS analysis, there is a function called "back-projection," which reverses each voxel on the mean FA skeleton back to its original place in native space. 11 This function may be beneficial, especially for the cohort including patients with iNPH, to confirm the accuracy of registration by showing the direct relationship between the TBSS results for standard space and those of the native image.…”