TractEM: Evaluation of protocols for deterministic tractography white matter atlas

2021 ◽  
Author(s):  
Francois Rheault ◽  
Roza G. Bayrak ◽  
Xuan Wang ◽  
Kurt G. Schilling ◽  
Jasmine M. Greer ◽  
...  
Keyword(s):  
White Matter ◽  
Deterministic Tractography

scholarly journals Change in Right Inferior Longitudinal Fasciculus Integrity Is Associated With Naming Recovery in Subacute Poststroke Aphasia

2020 ◽  
Vol 34 (9) ◽  
pp. 784-794
Author(s):  
Marieke Blom-Smink ◽  
Marjolein Verly ◽  
Kerstin Spielmann ◽  
Marion Smits ◽  
Gerard M. Ribbers ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Change Score ◽  
Strong Positive Correlation ◽  
Boston Naming Test ◽  
Inferior Longitudinal Fasciculus ◽  
Deterministic Tractography ◽  
The Right ◽  
Left Hemisphere Stroke ◽  
Microstructural Integrity

Background. Despite progress made in understanding functional reorganization patterns underlying recovery in subacute aphasia, the relation between recovery and changes in white matter structure remains unclear. Objective. To investigate changes in dorsal and ventral language white matter tract integrity in relation to naming recovery in subacute poststroke aphasia. Methods. Ten participants with aphasia after left-hemisphere stroke underwent language testing and diffusion tensor imaging twice within 3 months post onset, with a 1-month interval between sessions. Deterministic tractography was used to bilaterally reconstruct the superior longitudinal fasciculus (SLF), inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), middle longitudinal fasciculus (MdLF), and uncinate fasciculus (UF). Per tract, the mean fractional anisotropy (FA) was extracted as a measure of microstructural integrity. Naming accuracy was assessed with the Boston Naming Test (BNT). Correlational analyses were performed to investigate the relationship between changes in FA values and change in BNT score. Results. A strong positive correlation was found between FA change in the right ILF within the ventral stream and change on the BNT ( r = 0.91, P < .001). An increase in FA in the right ILF was associated with considerable improvement of naming accuracy (range BNT change score: 12-14), a reduction with limited improvement or slight deterioration. No significant correlations were found between change in naming accuracy and FA change in any of the other right or left ventral and dorsal language tracts. Conclusions. Naming recovery in subacute aphasia is associated with change in the integrity of the right ILF.

scholarly journals TractEM: Fast Protocols for Whole Brain Deterministic Tractography-Based White Matter Atlas

2019 ◽  
Author(s):  
Roza G. Bayrak ◽  
Xuan Wang ◽  
Kurt G. Schilling ◽  
Jasmine M. Greer ◽  
Colin B. Hansen ◽  
...  
Keyword(s):  
White Matter ◽  
Correlation Coefficient ◽  
Mean Squared Error ◽  
Intraclass Correlation ◽  
Structural Connectivity ◽  
Fiber Bundles ◽  
Initial Stage ◽  
Human Connectome Project ◽  
Baltimore Longitudinal Study ◽  
Deterministic Tractography

AbstractReproducible identification of white matter tracts across subjects is essential for the study of structural connectivity of the human brain. The key challenges are anatomical differences between subjects and human rater subjectivity in labeling. Labeling white matter regions of interest presents many challenges due to the need to integrate both local and global information. Clearly communicating the human/manual processes to capture this information is cumbersome, yet essential to lay a solid foundation for comprehensive atlases. The state-of-the-art for white matter atlas is the single population-averaged Johns Hopkins Eve atlas. A critical bottleneck with the Eve atlas framework is that manual labeling time is extensive and peripheral white matter regions are conservatively labeled. In this work, we developed protocols that will facilitate manual virtual dissection of white matter pathways, with the goals to be anatomically accurate, intuitive, reproducible, and act as an initial stage to build an amenable knowledge base of neuroanatomical regions. We analyzed reproducibility of the fiber bundles and variability of human raters using DICE correlation coefficient, intraclass correlation coefficient, and root mean squared error. The protocols at their initial stage have shown promising results on both typical 3T research acquisition Baltimore Longitudinal Study of Aging and high-acquisition quality Human Connectome Project datasets. The TractEM manual labeling protocols allow for reconstruction of reproducible subject-specific fiber bundles across the brain. The protocols and sample results have been made available in open source to improve generalizability and reliability in collaboration.

scholarly journals Structure, Asymmetry and Segmentation of the Human Parietal Aslant and Vertical Occipital Fasciculi

2018 ◽  
Author(s):  
Sandip S Panesar ◽  
Joao Tiago A Belo ◽  
Fang-Cheng Yeh ◽  
Juan C Fernandez-Miranda
Keyword(s):  
White Matter ◽  
Normal Subjects ◽  
Arcuate Fasciculus ◽  
Bipartite System ◽  
Human Connectome Project ◽  
Average Diffusion ◽  
Single Subjects ◽  
Deterministic Tractography

AbstractWe previously proposed a bipartite ‘dorsal-ventral’ model of human arcuate fasciculus (AF) morphology. This model does not, however, account for the ‘vertical,’ temporoparietal subdivision of the AF described in earlier dissection and tractographic studies. In an effort to address the absence of the vertical AF (VAF) within the ‘dorsal-ventral’ model, we conducted a dedicated tractographic and white-matter dissection study of this tract and another short, vertical, posterior-hemispheric fascicle: the vertical occipital fasciculus (VOF). We conducted atlas-based, non-tensor, deterministic tractography in 30 single subjects from the Human Connectome Project database and verified our results using an average diffusion atlas comprising 842 separate normal subjects. We also performed white-matter dissection in 4 cadaveric hemispheres. Our tractographic results demonstrate that the VAF is in fact a bipartite system connecting the ventral-parietal and ventral-temporal regions, with variable connective and no volumetric lateralization. The VOF is a nonlateralized, non-segmented system connecting lateral occipital areas with basal-temporal regions. Importantly, the VOF was distinctly dissociated from the VAF. As the VAF demonstrates no overall connective or volumetric lateralization, we postulate its distinction from the AF system and propose its renaming to the ‘parietal aslant tract,’ (PAT) with unique dorsal and ventral subdivisions. Our tractography results were supported by diffusion atlas and white matter dissection findings.

scholarly journals Associations of behavioral problems and white matter properties of the cerebellar peduncles in boys and girls born full term and preterm

2021 ◽  
Author(s):  
Machiko Hosoki ◽  
Lisa Bruckert ◽  
Lauren Borchers ◽  
Virginia Marchman ◽  
Katherine Travis ◽  
...  
Keyword(s):  
White Matter ◽  
Middle Childhood ◽  
Behavioral Problems ◽  
Internalizing Problems ◽  
Externalizing Problems ◽  
Full Term ◽  
School Aged Children ◽  
Cerebellar Peduncles ◽  
Deterministic Tractography

Accumulating evidence suggests that the role of cerebellum includes regulation of behaviors; Cerebellar impairment may lead to behavioral problems. Behavioral problems differ by sex: internalizing problems are more common in girls, externalizing problems in boys. Behavioral problems are also elevated in children born preterm (PT) compared to children born full-term (FT). The current study examined internalizing and externalizing problems in 8-year-old children in relation to sex, birth-group, FA of the cerebellar peduncles, and interactions among these predictor variables. Participants (N=78) were 44 boys (28 PT) and 34 girls (15 PT). We assessed behavioral problems via standardized parent-reports and FA of the cerebellar peduncles using deterministic tractography. Internalizing problems were higher in children born PT compared to children born FT (p=.032); the interaction of sex and birth-group was significant (p=.044). When considering the contribution of the mean-tract FA of cerebellar peduncles to behavioral problems, there was a significant interaction of sex and mean-tract FA of the ICP with internalizing problems; the slope was negative in girls (p=.020) but not boys. In boys, internalizing problems were only associated with mean-tract FA ICP in those born preterm (p=.010). We found no other significant associations contributing to internalizing or externalizing problems. Thus, we found sexual dimorphism and birth-group differences in the association of white matter metrics of the ICP and internalizing problems in school-aged children. The findings inform theories of the origins of internalizing behavioral problems in middle childhood and may suggest approaches to treatment at school age.

FT-IR microspectroscopic analysis of diseased white matter brain tissues

1995 ◽  
Vol 53 ◽  
pp. 968-969
Author(s):  
Steven M. Le Vine ◽  
David L. Wetzel
Keyword(s):  
White Matter ◽  
Gray Matter ◽  
Twitcher Mouse ◽  
Grid Pattern ◽  
Marked Contrast ◽  
Spatially Resolved ◽  
Ft Ir ◽  
Ir Microspectroscopy ◽  
Chemical Evidence

In situ FT-IR microspectroscopy has allowed spatially resolved interrogation of different parts of brain tissue. In previous work the spectrrscopic features of normal barin tissue were characterized. The white matter, gray matter and basal ganglia were mapped from appropriate peak area measurements from spectra obtained in a grid pattern. Bands prevalent in white matter were mostly associated with the lipid. These included 2927 and 1469 cm-1 due to CH2 as well as carbonyl at 1740 cm-1. Also 1235 and 1085 cm-1 due to phospholipid and galactocerebroside, respectively (Figs 1and2). Localized chemical changes in the white matter as a result of white matter diseases have been studied. This involved the documentation of localized chemical evidence of demyelination in shiverer mice in which the spectra of white matter lacked the marked contrast between it and gray matter exhibited in the white matter of normal mice (Fig. 3).The twitcher mouse, a model of Krabbe’s desease, was also studied. The purpose in this case was to look for a localized build-up of psychosine in the white matter caused by deficiencies in the enzyme responsible for its breakdown under normal conditions.

Sign in / Sign up

Export Citation Format

Share Document