scholarly journals Parametric Mapping of Brain Tissues from Diffusion Kurtosis Tensor

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Yuanyuan Chen ◽  
Xin Zhao ◽  
Hongyan Ni ◽  
Jie Feng ◽  
Hao Ding ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Regional Analysis ◽  
Gaussian Model ◽  
Gaussian Mixture ◽  
Diffusion Kurtosis Imaging ◽  
Mean Values ◽  
Detailed Classification ◽  
Magnetic Resonance Imaging Mri ◽  
Non Gaussian ◽  
Diffusion Kurtosis

Diffusion kurtosis imaging (DKI) is a new diffusion magnetic resonance imaging (MRI) technique to go beyond the shortages of conventional diffusion tensor imaging (DTI) from the assumption that water diffuse in biological tissue is Gaussian. Kurtosis is used to measure the deviation of water diffusion from Gaussian model, which is called non-Gaussian, in DKI. However, the high-order kurtosis tensor in the model brings great difficulties in feature extraction. In this study, parameters like fractional anisotropy of kurtosis eigenvalues (FAek) and mean values of kurtosis eigenvalues (Mek) were proposed, and regional analysis was performed for 4 different tissues: corpus callosum, crossing fibers, thalamus, and cerebral cortex, compared with other parameters. Scatterplot analysis and Gaussian mixture decomposition of different parametric maps are used for tissues identification. Diffusion kurtosis information extracted from kurtosis tensor presented a more detailed classification of tissues actually as well as clinical significance, and the FAek ofD-eigenvalues showed good sensitivity of tissues complexity which is important for further study of DKI.

scholarly journals Differential cortical microstructural maturation in the preterm human brain with diffusion kurtosis and tensor imaging

2019 ◽  
Vol 116 (10) ◽  
pp. 4681-4688 ◽  
Author(s):  
Minhui Ouyang ◽  
Tina Jeon ◽  
Aristeidis Sotiras ◽  
Qinmu Peng ◽  
Virendra Mishra ◽  
...  
Keyword(s):  
Human Brain ◽  
Diffusion Tensor ◽  
Cortical Plate ◽  
Diffusion Kurtosis Imaging ◽  
Third Trimester ◽  
Microstructural Changes ◽  
The Third ◽  
Cortical Regions ◽  
Non Gaussian ◽  
Diffusion Kurtosis

During the third trimester, the human brain undergoes rapid cellular and molecular processes that reshape the structural architecture of the cerebral cortex. Knowledge of cortical differentiation obtained predominantly from histological studies is limited in localized and small cortical regions. How cortical microstructure is differentiated across cortical regions in this critical period is unknown. In this study, the cortical microstructural architecture across the entire cortex was delineated with non-Gaussian diffusion kurtosis imaging as well as conventional diffusion tensor imaging of 89 preterm neonates aged 31–42 postmenstrual weeks. The temporal changes of cortical mean kurtosis (MK) or fractional anisotropy (FA) were heterogeneous across the cortical regions. Cortical MK decreases were observed throughout the studied age period, while cortical FA decrease reached its plateau around 37 weeks. More rapid decreases in MK were found in the primary visual region, while faster FA declines were observed in the prefrontal cortex. We found that distinctive cortical microstructural changes were coupled with microstructural maturation of associated white matter tracts. Both cortical MK and FA measurements predicted the postmenstrual age of preterm infants accurately. This study revealed a differential 4D spatiotemporal cytoarchitectural signature inferred by non-Gaussian diffusion barriers inside the cortical plate during the third trimester. The cytoarchitectural processes, including dendritic arborization and neuronal density decreases, were inferred by regional cortical FA and MK measurements. The presented findings suggest that cortical MK and FA measurements could be used as effective imaging markers for cortical microstructural changes in typical and potentially atypical brain development.

scholarly journals White matter microstructural integrity across the adult lifespan: Combined perspective of diffusion tensor and kurtosis imaging

2021 ◽  
Author(s):  
Hiba Taha ◽  
Jordan A Chad ◽  
J. Jean Chen
Keyword(s):  
White Matter ◽  
Brain Aging ◽  
Diffusion Tensor ◽  
Diffusion Imaging ◽  
General Pattern ◽  
B Value ◽  
Diffusion Kurtosis Imaging ◽  
Adult Lifespan ◽  
Non Gaussian ◽  
Diffusion Kurtosis

Studies of healthy brain aging have reported diffusivity patterns associated with white matter degeneration using diffusion tensor imaging (DTI), which assumes that diffusion measured at the typical b-value (approximately 1000 s/mm2) is Gaussian. Diffusion kurtosis imaging (DKI) is an extension of DTI that measures non-Gaussian diffusion (kurtosis) to better capture microenvironmental changes by incorporating additional data at a higher b-value. In this study, using UK Biobank data (b values of 1000 and 2000 s/mm2), we investigate (1) the extent of novel information gained from adding diffusional kurtosis to diffusivity observations in aging, and (2) how conventional DTI metrics in aging compare with diffusivity metrics derived from DKI, which are corrected for kurtosis. We find a general pattern of lower kurtosis alongside higher diffusivity among older adults. We also find differences between diffusivity metrics derived from DTI and DKI, emphasizing the importance of accounting for non-Gaussian diffusion. This work highlights the utility of measuring diffusional kurtosis as a simple addition to conventional diffusion imaging of aging.

scholarly journals Diffusion kurtosis imaging of white matter in bipolar disorder

2021 ◽  
Author(s):  
Vina M Goghari ◽  
Mavis Kusi ◽  
Mohammed K Shakeel ◽  
Clare Beasley ◽  
Szabolcs David ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
White Matter ◽  
Diffusion Tensor ◽  
Brain Regions ◽  
Diffusion Kurtosis Imaging ◽  
Simple Diffusion ◽  
Spherical Deconvolution ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Diffusion Kurtosis

AbstractObjectivesWhite matter pathology is thought to contribute to the pathogenesis of bipolar disorder (BD). However, most studies of white matter in BD have used the simple diffusion tensor imaging (DTI) model, which has several limitations. DTI studies have reported heterogenous results, leading to a lack of consensus about the extent and location of white matter alterations. Here, we applied two advanced diffusion magnetic resonance imaging (MRI) techniques to investigate white matter microstructure in BD.MethodsTwenty-five patients with BD and 24 controls comparable for age and sex were included in the study. Whole-brain voxel-based analysis (VBA) and a network-based connectivity approach using constrained spherical deconvolution (CSD)-tractography were used to assess group differences in diffusion kurtosis imaging (DKI) and DTI metrics.ResultsVBA showed lower mean kurtosis in the corona radiata and posterior association fibers in BD following threshold-free cluster enhancement. Regional differences in connectivity were indicated by lower mean kurtosis and kurtosis anisotropy in streamlines traversing the temporal and occipital lobes, and lower mean axial kurtosis in the right cerebellar, thalamo-subcortical pathways in BD. Significant differences were not seen in the DTI metrics following FDR- correction.ConclusionsDifferences between BD and controls were observed in DKI metrics in multiple brain regions, indicating altered connectivity across cortical, subcortical and cerebellar areas. DKI was more sensitive than DTI at detecting these differences, suggesting that DKI is useful for investigating white matter in BD.

scholarly journals More accurate estimation of diffusion tensor parameters using diffusion kurtosis imaging

2010 ◽  
Vol 65 (1) ◽  
pp. 138-145 ◽  
Author(s):  
Jelle Veraart ◽  
Dirk H. J. Poot ◽  
Wim Van Hecke ◽  
Ines Blockx ◽  
Annemie Van der Linden ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Diffusion Kurtosis Imaging ◽  
Accurate Estimation ◽  
Diffusion Kurtosis

scholarly journals Diffusion Kurtosis Imaging of Substantia Nigra Is a Sensitive Method for Early Diagnosis and Disease Evaluation in Parkinson’s Disease

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Guohua Zhang ◽  
Yuhu Zhang ◽  
Chengguo Zhang ◽  
Yukai Wang ◽  
Guixian Ma ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Rating Scale ◽  
Diffusion Tensor ◽  
Diffusion Kurtosis Imaging ◽  
Healthy Controls ◽  
Potential Biomarker ◽  
Diffusion Kurtosis ◽  
Sensitive Method

Background.To diagnose Parkinson disease (PD) in an early stage and accurately evaluate severity, it is important to develop a sensitive method for detecting structural changes in the substantia nigra (SN).Method.Seventy-two untreated patients with early PD and 72 healthy controls underwent diffusion tensor and diffusion kurtosis imaging. Regions of interest were drawn in the rostral, middle, and caudal SN by two blinded and independent raters. Mean kurtosis (MK) and fractional anisotropy in the SN were compared between the groups. Receiver operating characteristic (ROC) and Spearman correlation analyses were used to compare the diagnostic accuracy and correlate imaging findings with Hoehn-Yahr (H-Y) staging and part III of the Unified Parkinson’s Disease Rating Scale (UPDRS-III).Result.MK in the SN was increased significantly in PD patients compared with healthy controls. The area under the ROC curve was 0.976 for MK in the SN (sensitivity, 0.944; specificity, 0.917). MK in the SN had a positive correlation with H-Y staging and UPDRS-III scores.Conclusion.Diffusion kurtosis imaging is a sensitive method for PD diagnosis and severity evaluation. MK in the SN is a potential biomarker for imaging studies of early PD that can be widely used in clinic.

Three-dimensional characterization of non-gaussian water diffusion in humans using diffusion kurtosis imaging

2006 ◽  
Vol 19 (2) ◽  
pp. 236-247 ◽  
Author(s):  
Hanzhang Lu ◽  
Jens H. Jensen ◽  
Anita Ramani ◽  
Joseph A. Helpern
Keyword(s):  
Three Dimensional ◽  
Water Diffusion ◽  
Diffusion Kurtosis Imaging ◽  
Non Gaussian ◽  
Diffusion Kurtosis
Sign in / Sign up

Export Citation Format

Share Document