Longitudinal comparison of pre- and postoperative diffusion tensor imaging parameters in young children with hydrocephalus

2010 ◽  
Vol 5 (4) ◽  
pp. 385-391 ◽  
Author(s):  
Ellen L. Air ◽  
Weihong Yuan ◽  
Scott K. Holland ◽  
Blaise V. Jones ◽  
Karin Bierbrauer ◽  
...  

Object The goal in this study was to compare the integrity of white matter before and after ventriculoperitoneal (VP) shunt insertion by evaluating the anisotropic diffusion properties with the aid of diffusion tensor (DT) imaging in young children with hydrocephalus. Methods The authors retrospectively identified 10 children with hydrocephalus who underwent both pre- and postoperative DT imaging studies. The DT imaging parameters (fractional anisotropy [FA], mean diffusivity, axial diffusivity, and radial diffusivity) were computed and compared longitudinally in the splenium and genu of the corpus callosum (gCC) and in the anterior and posterior limbs of the internal capsule (PLIC). The patients' values on DT imaging at the pre- and postshunt stages were compared with the corresponding age-matched controls as well as with a large cohort of healthy children in the database. Results In the gCC, 7 of 10 children had abnormally low preoperative FA values, 6 of which normalized postoperatively. All 3 of the 10 children who had normal preoperative FA values had normal FA values postoperatively as well. In the PLIC, 7 of 10 children had abnormally high FA values, 6 of which normalized postoperatively, whereas the other one had abnormally low postoperative FA. Of the remaining 3 children, 2 had abnormally low preoperative FA values in the PLIC; this normalized in 1 patient after surgery. The other child had a normal preoperative FA value that became abnormally low postoperatively. When comparing the presurgery frequency of abnormally low, normal, and abnormally high FA values to those postsurgery, there was a statistically significant longitudinal difference in both gCC (p = 0.02) and PLIC (p = 0.002). Conclusions In this first longitudinal DT imaging study of young children with hydrocephalus, DT imaging anisotropy yielded abnormal results in several white matter regions of the brain, and trended toward normalization following VP shunt placement.

2009 ◽  
Vol 21 (7) ◽  
pp. 1406-1421 ◽  
Author(s):  
Elizabeth A. Olson ◽  
Paul F. Collins ◽  
Catalina J. Hooper ◽  
Ryan Muetzel ◽  
Kelvin O. Lim ◽  
...  

Healthy participants (n = 79), ages 9–23, completed a delay discounting task assessing the extent to which the value of a monetary reward declines as the delay to its receipt increases. Diffusion tensor imaging (DTI) was used to evaluate how individual differences in delay discounting relate to variation in fractional anisotropy (FA) and mean diffusivity (MD) within whole-brain white matter using voxel-based regressions. Given that rapid prefrontal lobe development is occurring during this age range and that functional imaging studies have implicated the prefrontal cortex in discounting behavior, we hypothesized that differences in FA and MD would be associated with alterations in the discounting rate. The analyses revealed a number of clusters where less impulsive performance on the delay discounting task was associated with higher FA and lower MD. The clusters were located primarily in bilateral frontal and temporal lobes and were localized within white matter tracts, including portions of the inferior and superior longitudinal fasciculi, anterior thalamic radiation, uncinate fasciculus, inferior fronto-occipital fasciculus, corticospinal tract, and splenium of the corpus callosum. FA increased and MD decreased with age in the majority of these regions. Some, but not all, of the discounting/DTI associations remained significant after controlling for age. Findings are discussed in terms of both developmental and age-independent effects of white matter organization on discounting behavior.


Cephalalgia ◽  
2015 ◽  
Vol 35 (13) ◽  
pp. 1162-1171 ◽  
Author(s):  
Catherine D Chong ◽  
Todd J Schwedt

Background Specific white-matter tract alterations in migraine remain to be elucidated. Using diffusion tensor imaging (DTI), this study investigated whether the integrity of white-matter tracts that underlie regions of the “pain matrix” is altered in migraine and interrogated whether the number of years lived with migraine modifies fibertract structure. Methods Global probabilistic tractography was used to assess the anterior thalamic radiations, the corticospinal tracts and the inferior longitudinal fasciculi in 23 adults with migraine and 18 healthy controls. Results Migraine patients show greater mean diffusivity (MD) in the left and right anterior thalamic radiations, the left corticospinal tract, and the right inferior longitudinal fasciculus tract. Migraine patients also show greater radial diffusivity (RD) in the left anterior thalamic radiations, the left corticospinal tract as well as the left and right inferior longitudinal fasciculus tracts. No group fractional anisotropy (FA) differences were identified for any tracts. Migraineurs showed a positive correlation between years lived with migraine and MD in the right anterior thalamic radiations ( r = 0.517; p = 0.012) and the left corticospinal tract ( r = 0.468; p = 0.024). Conclusion Results indicate that white-matter integrity is altered in migraine and that longer migraine history is positively correlated with greater alterations in tract integrity.


2008 ◽  
Vol 1 (4) ◽  
pp. 263-269 ◽  
Author(s):  
Weihong Yuan ◽  
Scott K. Holland ◽  
Blaise V. Jones ◽  
Kerry Crone ◽  
Francesco T. Mangano

Object Diffusion tensor (DT) imaging was used in children with supratentorial tumors to evaluate the anisotropic diffusion properties between different tumor grades and between tumors and adjacent and contralateral white matter. Methods In this retrospective review, the authors review the cases of 16 children (age range 1–18 years) who presented to their institution with supratentorial tumors and were treated between 2004 and 2007. Eleven patients had low-grade and 5 had high-grade tumors. Fractional anisotropy (FA), mean diffusivity, and axial (λ∥) and radial (λ⊥) eigenvalues within selected regions were studied. Mitotic index, necrosis, and vascularity of the tumors were compared with DT imaging parameters. Results The mean diffusivity was significantly higher in low-grade than in high-grade tumors (p = 0.04); the 2 tumor grades also significantly differed for both λ∥ (p < 0.05) and λ⊥ (p < 0.05). Mean diffusivity values in low-grade tumors were significantly higher than in adjacent normal-appearing white matter (NAWM; p = 0.0004) and contralateral NAWM (p = 0.0001). In both low- and high-grade tumors, the FA was significantly lower than in NAWM (p < 0.0001 and p < 0.03, respectively) and contralateral NAWM (p < 0.0001 and p < 0.003, respectively). Tumor cellularity highly correlated with mean diffusivity and λ∥and λ⊥. Conclusions Diffusion tensor imaging is a useful tool in the evaluation of supratentorial tumors in children. The mean diffusivity appears to be a significant marker in differentiating tumors grades. Findings related to λ∥ and λ⊥ within tumor groups and between tumors and NAWM may be an indirect manifestation of the combined effects of axonal injury, demyelination, and tumor mass within the cranial compartment.


2021 ◽  
Author(s):  
Xiaoyu Xu ◽  
Yuying Jin ◽  
Ning Pan ◽  
Muqing Cao ◽  
Jin Jing ◽  
...  

Abstract Cantonese and Mandarin are logographic languages, and the phonology is the main difference between the two languages. It is unclear whether long-term experience of Cantonese-Mandarin bilingualism will shape different brain white matter structures of pathways related to phonological processing. 30 Cantonese-Mandarin bilinguals and 30 Mandarin monolinguals completed diffusion-weighted imaging (DWI) scans and phonological processing tasks. The tractography and TBSS were used to investigate the structural differences in the bilateral superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF) and inferior fronto-occipital fasciculus (IFOF) between Cantonese-Mandarin bilinguals and Mandarin monolinguals. Post-hoc correlation analysis was conducted to investigate the relationship between the different structures with phonological processing skills. Compared to the Mandarin monolinguals, the Cantonese-Mandarin bilinguals had higher fractional anisotropy (FA) along the left ILF, higher mean diffusivity (MD) in the clusters along the temporoparietal segment of SLF (tSLF), as well as higher axial diffusivity (AD) in the right tSLF, IFOF, bilateral ILF. The mean AD of the different voxels in the right IFOF and the mean FA of the different voxels in the left ILF were positively correlated with the inverse efficiency score (IES) of the Cantonese auditory and Mandarin visual rhyming judgment tasks respectively within the bilingual group. Long-term experience of Cantonese-Mandarin bilinguals shape different brain white matter structures including right tSLF, IFOF, bilateral ILF. The bilinguals’ white matter showed higher diffusivity, especially in the axonal direction, than the monolinguals. These changes were related to bilinguals’ phonological processing.


2021 ◽  
Vol 13 ◽  
Author(s):  
Donglai Jing ◽  
Yaojing Chen ◽  
Kexin Xie ◽  
Yue Cui ◽  
Chunlei Cui ◽  
...  

ObjectiveThe objective of the study was to explore patterns of white matter (WM) alteration in preclinical stage familial Creutzfeldt–Jakob disease (fCJD) using diffusion tensor imaging (DTI).MethodsSeven asymptomatic carriers of the PRNP G114V mutation and six non-carriers were recruited from the same fCJD kindred and follow-up obtained from all asymptomatic carriers and two non-carriers 2 years later. Overlapping WM patterns were also explored in asymptomatic carriers and symptomatic CJD patients. All participants underwent clinical and neuropsychological assessments and DTI at baseline and follow-up. DTI data were subjected to whole-brain voxel-wise analysis of fractional anisotropy (FA) and mean diffusivity (MD) in WM using tract-based spatial statistics. Three comparisons were conducted: baseline carriers against non-carriers (baseline analysis), changes after 2 years in carriers (follow-up analysis), and differences between patients with symptomatic CJD and healthy controls (CJD patient analysis).ResultsNeither carriers nor non-carriers developed any neurological symptoms during 2 years of follow-up. Baseline analysis showed no differences between the carrier and non-carrier groups in MD and FA. Follow-up analysis showed significantly increased MD in multiple WM tracts, among which increased MD in the bilateral superior longitudinal fasciculus, bilateral anterior thalamic radiation, bilateral cingulate gyrus, and left uncinate fasciculus overlapped the patterns observed in patients with symptomatic CJD.ConclusionChanges in integrity within multiple WM tracts can be detected during the preclinical stage of fCJD.


Diabetes Care ◽  
2012 ◽  
Vol 35 (11) ◽  
pp. 2167-2173 ◽  
Author(s):  
T. Aye ◽  
N. Barnea-Goraly ◽  
C. Ambler ◽  
S. Hoang ◽  
K. Schleifer ◽  
...  

2018 ◽  
Vol 29 (2) ◽  
pp. 233-241 ◽  
Author(s):  
Amjad Samara ◽  
Kaiyang Feng ◽  
R. Terry Pivik ◽  
Kelly P. Jarratt ◽  
Thomas M. Badger ◽  
...  

2019 ◽  
Author(s):  
Szabolcs David ◽  
Hamed Y. Mesri ◽  
Victor A. Bodiut ◽  
Steven H. J. Nagtegaal ◽  
Hesham Elhalawani ◽  
...  

AbstractBackground and purposeRadiation-induced changes in brain tissue may relate to post-radiotherapy (RT) cognitive decline. Our aim is to investigate changes of the brain microstructural properties after exposure to radiation during clinical protocols of RT using diffusion MRI (dMRI).Methods and MaterialsThe susceptibility of tissue changes to radiation was investigated in a clinically heterogenic cohort (age, pathology, tumor location, type of surgery) consisting of 121 scans of 18 patients (10 females). The imaging dataset included 18 planning CTs and 103 dMRI scans (range 2-14, median = 6 per patient) assessing pre-operative, post-operative pre-RT and post-RT states. Diffusion tensor imaging (DTI) metrics were estimated from all scans for a region-of-interest based linear relation analysis between mean dose and change in DTI metrics, while partial volume effects were regressed out.ResultsThe largest regional dose dependency with mean diffusivity appear in the white matter of the frontal pole in the left hemisphere by an increase of 2.61 %/(Gy x year). Full brain-wise, pooled results for white matter show fractional anisotropy to decrease by 0.85 %/(30Gy x year); mean diffusivity increase by 9.17 %/(30Gy x year); axial diffusivity increase by 7.30%/(30Gy x year) and radial diffusivity increases by 10.63%/(30Gy x year).ConclusionsWhite matter is susceptible to radiation with some regional variability where diffusivity metrics demonstrate the largest relative sensitivity. This suggests that dMRI is a promising tool in assessing microstructural changes after RT, which can help in understanding treatment-induced cognitive decline.


2020 ◽  
Vol 61 (12) ◽  
pp. 1677-1683 ◽  
Author(s):  
Kerim Aslan ◽  
Hediye Pinar Gunbey ◽  
Sumeyra Cortcu ◽  
Onur Ozyurt ◽  
Ugur Avci ◽  
...  

Background Metabolic, morphological, and functional brain changes associated with a neurological deficit in hyperthyroidism have been observed. However, changes in microstructural white matter (WM), which can explain the underlying pathophysiology of brain dysfunctions, have not been researched. Purpose To assess microstructural WM abnormality in patients with untreated or newly diagnosed hyperthyroidism using tract-based spatial statistics (TBSS). Material and Methods Eighteen patients with hyperthyroidism and 14 age- and sex-matched healthy controls were included in this study. TBSS were used in this diffusion tensor imaging study for a whole-brain voxel-wise analysis of fractional anisotropy, mean diffusivity, axial diffusivity (AD), and radial diffusivity (RD) of WM. Results When compared to the control group, TBSS showed a significant increase in the RD of the corpus callosum, anterior and posterior corona radiata, posterior thalamic radiation, cingulum, superior longitudinal fasciculus, and the retrolenticular region of the internal capsule in patients with hyperthyroidism ( P < 0.05), as well as a significant decrease in AD in the anterior corona radiata and the genu of corpus callosum ( P < 0.05). Conclusion This study showed that more regions are affected by the RD increase than the AD decrease in the WM tracts of patients with hyperthyroidism. These preliminary results suggest that demyelination is the main mechanism of microstructural alterations in the WM of hyperthyroid patients.


2017 ◽  
Vol 5 (1-2) ◽  
pp. 1-12
Author(s):  
L. Shrestha

Aim: To investigate the role of white matter integrity in the pathophysiology of tinnitus, and also to analyze the whole brain for white matter changes quantitatively by comparing tinnitus patients with healthy controls based on the affected side of the tinnitus using Tract Based Spatial Statistics (TBSS).Methods: Total of 41 right-handed tinnitus patients and 35 age-matched right-handed healthy controls were initially examined non-invasively in resting-state using the 3.0T MRI scanner. We obtained the estimated Fractional anisotropy (FA), mean diffusivity (MD), Axial Diffusivity (AD), Radial Diffusivity (RD), and Mode of Anisotropy (MO) data for each subject. TBSS was used to perform group statistical analysis of DTI data from each group.Results: Compared to controls in right-sided tinnitus patients, FA and MO were decreased, and MD was normal with decreased AD and increased RD. FA and AD showed similar decreased values (t>1.5, FWEcorrected P<0.05) in the right corticospinal tract, right superior longitudinal fasciculus, and right inferior fronto-occipital fasciculus. Compared to controls with left-sided tinnitus patients, FA and MO were decreased, and MD was also increased with decreased AD with increased RD in patients. MO showed significantly decreased values (t>1.5, FWEcorrected P<0.05) of MO in Forceps major, bilateral cingulum (especially the left), and bilateral anterior thalamic radiation. Bilaterally affected tinnitus patients showed no difference when compared to controls.Conclusion: After analyzing the whole brain for white matter changes quantitatively using TBSS, changes were observed in unilaterally affected tinnitus patients compared to controls. Our findings indicated cross-modal plasticity could have caused changes in somatosensory, audio-visual, limbic, and attention pathways.Nepal Journal of Radiology Vol.5(1-2) 2015: 1-12


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