Free water elimination and mapping from diffusion MRI

2009 ◽  
Vol 62 (3) ◽  
pp. 717-730 ◽  
Author(s):  
Ofer Pasternak ◽  
Nir Sochen ◽  
Yaniv Gur ◽  
Nathan Intrator ◽  
Yaniv Assaf
Keyword(s):  
Diffusion Mri ◽  
Free Water ◽  
Water Elimination

scholarly journals [Re] Optimization of a free water elimination two-compartment model for diffusion tensor imaging

2017 ◽  
Author(s):  
Rafael Neto Henriques ◽  
Ariel Rokem ◽  
Eleftherios Garyfallidis ◽  
Samuel St-Jean ◽  
Eric Thomas Peterson ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Mri ◽  
Diffusion Tensor ◽  
Free Water ◽  
Compartment Model ◽  
B Values ◽  
Brain White Matter ◽  
Diffusion Weighted ◽  
Two Compartment Model ◽  
Water Elimination

Typical diffusion-weighted imaging (DWI) is susceptible to partial volume effects: different types of tissue that reside in the same voxel are inextricably mixed. For instance, in regions near the cerebral ventricles or parenchyma, fractional anisotropy (FA) from diffusion tensor imaging (DTI) may be underestimated, due to partial volumes of cerebral spinal fluid (CSF). Free-water can be suppressed by adding parameters to diffusion MRI models. For example, the DTI model can be extended to separately take into account the contributions of tissue and CSF, by representing the tissue compartment with an anisotropic diffusion tensor and the CSF compartment as an isotropic free water diffusion coefficient. Recently, two procedures were proposed to fit this two-compartment model to diffusion-weighted data acquired for at least two different non-zero diffusion MRI b-values. In this work, the first open-source reference implementation of these procedures is provided. In addition to presenting some methodological improvements that increase model fitting robustness, the free water DTI procedures are re-evaluated using Monte-Carlo multicompartmental simulations. Analogous to previous studies, our results show that the free water elimination DTI model is able to remove confounding effects of fast diffusion for typical FA values of brain white matter. In addition, this study confirms that for a fixed scanning time the fwDTI fitting procedures have better performance when data is acquired for diffusion gradient direction evenly distributed along two b-values of 500 and 1500 s/mm2.

scholarly journals Separating blood and water: Perfusion and free water elimination from diffusion MRI in the human brain

NeuroImage ◽  
2017 ◽  
Vol 156 ◽  
pp. 423-434 ◽  
Author(s):  
Anna S. Rydhög ◽  
Filip Szczepankiewicz ◽  
Ronnie Wirestam ◽  
André Ahlgren ◽  
Carl-Fredrik Westin ◽  
...  
Keyword(s):  
Human Brain ◽  
Diffusion Mri ◽  
Free Water ◽  
Water Elimination

scholarly journals Diffusion MRI free water is a sensitive marker of age-related changes in the cingulum

2019 ◽  
Author(s):  
Manon Edde ◽  
Guillaume Theaud ◽  
François Rheault ◽  
Bixente Dilharreguy ◽  
Catherine Helmer ◽  
...  
Keyword(s):  
White Matter ◽  
Verbal Fluency ◽  
Diffusion Mri ◽  
White Matter Hyperintensities ◽  
Free Water ◽  
Partial Volume ◽  
Cingulum Bundle ◽  
Partial Volume Effects ◽  
Age Related ◽  
Water Elimination

AbstractDiffusion MRI is extensively used to investigate changes in white matter microstructure. However, diffusion measures within white matter tissue can be affected by partial volume effects due to cerebrospinal fluid and white matter hyperintensities, especially in the aging brain. In previous aging studies, the cingulum bundle that plays a central role in the architecture of the brain networks supporting cognitive functions has been associated with cognitive deficits. However, most of these studies did not consider the partial volume effects on diffusion measures. The aim of this study was to evaluate the effect of free water elimination on diffusion measures of the cingulum in a group of 68 healthy elderly individuals. We first determined the effect of free water elimination on conventional DTI measures and then examined the effect of free water elimination on verbal fluency performance over 12 years. The cingulum bundle was reconstructed with a tractography pipeline including a white matter hyperintensities mask to limit the negative impact of hyperintensities on fiber tracking algorithms. We observed that free water elimination improved the sensitivity of conventional DTI measures to detect associations between tissue-specific diffusion measures of the cingulum and changes in verbal fluency in older individuals. Moreover, free water content measured along the cingulum was independently strongly associated with changes in verbal fluency. These observations suggest the importance of using free water elimination when studying brain aging and indicate that free water itself could be a relevant marker for age-related cingulum white matter modifications and cognitive decline.

Characterizing Extracellular White Matter Pathologies Using Free Water Imaging Across the Schizophrenia Illness Course: A Multi-Site Harmonized Diffusion MRI Study

2021 ◽  
Vol 89 (9) ◽  
pp. S85
Author(s):  
Suheyla Cetin-Karayumak ◽  
Ofer Pasternak ◽  
Fan Zhang ◽  
Johanna Seitz ◽  
Doron Elad ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Mri ◽  
Free Water ◽  
Mri Study

Characterizing Peritumoral Tissue Using DTI-Based Free Water Elimination

2019 ◽  
pp. 123-131 ◽  
Author(s):  
Abdol Aziz Ould Ismail ◽  
Drew Parker ◽  
Moises Hernandez-Fernandez ◽  
Steven Brem ◽  
Simon Alexander ◽  
...  
Keyword(s):  
Free Water ◽  
Water Elimination ◽  
Peritumoral Tissue

scholarly journals White-matter free-water diffusion MRI in schizophrenia: a systematic review and meta-analysis

2022 ◽  
Author(s):  
Inês Carreira Figueiredo ◽  
Faith Borgan ◽  
Ofer Pasternak ◽  
Federico E. Turkheimer ◽  
Oliver D. Howes
Keyword(s):  
White Matter ◽  
Healthy Volunteers ◽  
Diffusion Mri ◽  
Clinical Symptoms ◽  
Free Water ◽  
Brain Regions ◽  
Water Levels ◽  
First Episode ◽  
Whole Brain ◽  
Illness Duration

AbstractWhite-matter abnormalities, including increases in extracellular free-water, are implicated in the pathophysiology of schizophrenia. Recent advances in diffusion magnetic resonance imaging (MRI) enable free-water levels to be indexed. However, the brain levels in patients with schizophrenia have not yet been systematically investigated. We aimed to meta-analyse white-matter free-water levels in patients with schizophrenia compared to healthy volunteers. We performed a literature search in EMBASE, MEDLINE, and PsycINFO databases. Diffusion MRI studies reporting free-water in patients with schizophrenia compared to healthy controls were included. We investigated the effect of demographic variables, illness duration, chlorpromazine equivalents of antipsychotic medication, type of scanner, and clinical symptoms severity on free-water measures. Ten studies, including five of first episode of psychosis have investigated free-water levels in schizophrenia, with significantly higher levels reported in whole-brain and specific brain regions (including corona radiata, internal capsule, superior and inferior longitudinal fasciculus, cingulum bundle, and corpus callosum). Six studies, including a total of 614 participants met the inclusion criteria for quantitative analysis. Whole-brain free-water levels were significantly higher in patients relative to healthy volunteers (Hedge’s g = 0.38, 95% confidence interval (CI) 0.07–0.69, p = 0.02). Sex moderated this effect, such that smaller effects were seen in samples with more females (z = −2.54, p < 0.05), but antipsychotic dose, illness duration and symptom severity did not. Patients with schizophrenia have increased free-water compared to healthy volunteers. Future studies are necessary to determine the pathological sources of increased free-water, and its relationship with illness duration and severity.

scholarly journals Dedicated diffusion phantoms for the investigation of free water elimination and mapping: insights into the influence of T 2 relaxation properties

2020 ◽  
Vol 33 (4) ◽  
Author(s):  
Ezequiel Farrher ◽  
Farida Grinberg ◽  
Li‐Wei Kuo ◽  
Kuan‐Hung Cho ◽  
Richard P. Buschbeck ◽  
...  
Keyword(s):  
Free Water ◽  
Relaxation Properties ◽  
Water Elimination

scholarly journals Diffusion kurtosis imaging with free water elimination: A bayesian estimation approach

2018 ◽  
Vol 80 (2) ◽  
pp. 802-813 ◽  
Author(s):  
Quinten Collier ◽  
Jelle Veraart ◽  
Ben Jeurissen ◽  
Floris Vanhevel ◽  
Pim Pullens ◽  
...  
Keyword(s):  
Bayesian Estimation ◽  
Free Water ◽  
Diffusion Kurtosis Imaging ◽  
Water Elimination ◽  
Diffusion Kurtosis

scholarly journals A diffusion model‐free framework with echo time dependence for free‐water elimination and brain tissue microstructure characterization

2018 ◽  
Vol 80 (5) ◽  
pp. 2155-2172 ◽  
Author(s):  
Miguel Molina‐Romero ◽  
Pedro A. Gómez ◽  
Jonathan I. Sperl ◽  
Michael Czisch ◽  
Philipp G. Sämann ◽  
...  
Keyword(s):  
Time Dependence ◽  
Brain Tissue ◽  
Diffusion Model ◽  
Free Water ◽  
Microstructure Characterization ◽  
Tissue Microstructure ◽  
Model Free ◽  
Water Elimination ◽  
Echo Time
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