scholarly journals Relative indices of water diffusion anisotropy are equivalent in live and formalin-fixed mouse brains

2003 ◽  
Vol 50 (4) ◽  
pp. 743-748 ◽  
Author(s):  
Shu-Wei Sun ◽  
Jeffrey J. Neil ◽  
Sheng-Kwei Song
Keyword(s):  
Water Diffusion ◽  
Diffusion Anisotropy ◽  
Formalin Fixed

scholarly journals Microscopic diffusion anisotropy in formalin fixed prostate tissue: Preliminary findings

2012 ◽  
Vol 68 (6) ◽  
pp. 1943-1948 ◽  
Author(s):  
Roger M. Bourne ◽  
Nyoman Kurniawan ◽  
Gary Cowin ◽  
Paul Sved ◽  
Geoffrey Watson
Keyword(s):  
Prostate Tissue ◽  
Diffusion Anisotropy ◽  
Formalin Fixed

Human Acute Cerebral Ischemia: Detection of Changes in Water Diffusion Anisotropy by Using MR Imaging

Radiology ◽  
1999 ◽  
Vol 212 (3) ◽  
pp. 785-792 ◽  
Author(s):  
A. Gregory Sorensen ◽  
Ona Wu ◽  
William A. Copen ◽  
Timothy L. Davis ◽  
R. Gilberto Gonzalez ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Mr Imaging ◽  
Water Diffusion ◽  
Diffusion Anisotropy ◽  
Acute Cerebral Ischemia

scholarly journals Modeling water diffusion anisotropy within fixed newborn primate brain using Bayesian probability theory

2005 ◽  
Vol 55 (1) ◽  
pp. 187-197 ◽  
Author(s):  
Christopher D. Kroenke ◽  
G. Larry Bretthorst ◽  
Terrie E. Inder ◽  
Jeffrey J. Neil
Keyword(s):  
Probability Theory ◽  
Water Diffusion ◽  
Bayesian Probability ◽  
Diffusion Anisotropy ◽  
Primate Brain

scholarly journals Brain water diffusion coefficients and diffusion anisotropy in non-demented patients with diffuse leuko-araiosis.

1998 ◽  
Vol 65 (2) ◽  
pp. 167-172
Author(s):  
Toshikazu Tsuganesawa ◽  
Hironaka Igarashi ◽  
Shin Kitamura ◽  
Akiro Terashi
Keyword(s):  
Diffusion Coefficients ◽  
Water Diffusion ◽  
Diffusion Anisotropy ◽  
And Diffusion ◽  
Brain Water

scholarly journals Water diffusion anisotropy in white and gray matter of the human spinal cord

2008 ◽  
Vol 27 (3) ◽  
pp. 476-482 ◽  
Author(s):  
Cristina Rossi ◽  
Andreas Boss ◽  
Günter Steidle ◽  
Petros Martirosian ◽  
Uwe Klose ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Gray Matter ◽  
Water Diffusion ◽  
Diffusion Anisotropy ◽  
Human Spinal Cord

scholarly journals Rapid Microscopic Fractional Anisotropy Imaging via an Optimized Kurtosis Formulation

2020 ◽  
Author(s):  
N. J. J. Arezza ◽  
D. H. Y. Tse ◽  
C. A. Baron
Keyword(s):  
White Matter ◽  
Healthy Volunteers ◽  
Fractional Anisotropy ◽  
Water Diffusion ◽  
Direct Approach ◽  
Linear Regression Method ◽  
Cumulant Expansion ◽  
Diffusion Anisotropy ◽  
Gamma Model ◽  
Isotropic Resolution

AbstractWater diffusion anisotropy in the human brain is affected by disease, trauma, and development. Microscopic fractional anisotropy (μFA) is a diffusion MRI (dMRI) metric that can quantify water diffusion anisotropy independent of neuron fiber orientation dispersion. However, there are several different techniques to estimate μFA and few have demonstrated full brain imaging capabilities within clinically viable scan times and resolutions. Here, we present an optimized spherical tensor encoding (STE) technique to acquire μFA directly from the 2nd order cumulant expansion of the dMRI signal (i.e. diffusion kurtosis) which requires fewer powder-averaged signals than other STE fitting techniques and can be rapidly computed. We found that the optimal dMRI parameters for white matter μFA imaging were a maximum b-value of 2000 s/mm2 and a ratio of isotropic to linear tensor encoded acquisitions of 1.7 for our system specifications. We then compared two implementations of the direct approach to the well-established gamma model in 4 healthy volunteers on a 3 Tesla system. One implementation of the direct cumulant approach used mean diffusivity (D) obtained from a 2nd order fit of the cumulant expansion, while the other used a linear estimation of D from the low b-values. Both implementations of the direct approach showed strong linear correlations with the gamma model (ρ=0.97 and ρ=0.90) but mean biases of −0.11 and −0.02 relative to the gamma model were also observed, respectively. All three μFA measurements showed good test-retest reliability (ρ≥0.79 and bias=0). To demonstrate the potential scan time advantage of the direct approach, 2 mm isotropic resolution μFA was demonstrated over a 10 cm slab using a subsampled data set with fewer powder-averaged signals that would correspond to a 3.3-minute scan. Accordingly, our results introduce an optimization procedure that has enabled clinically relevant, nearly full brain μFA in only several minutes.HighlightsDemonstrated method to acquire optimal parameters for regression μFA imagingμFA measured using an optimized linear regression method at 3TFirst μFA comparison between direct regression approach and the gamma modelBoth approaches correlated strongly in white matter in healthy volunteersNearly full brain μFA demonstrated in a 3.3-minute scan at 2 mm isotropic resolution

Ultrastructural Localization of Acid Mucosubstance in Skeletal Muscle

1967 ◽  
Vol 25 ◽  
pp. 52-53 ◽  
Author(s):  
William J. Dougherty ◽  
Samuel S. Spicer
Keyword(s):  
Striated Muscle ◽  
Divalent Cations ◽  
Ultrastructural Localization ◽  
Major Elements ◽  
Frozen Sections ◽  
Thorium Dioxide ◽  
Iron Solution ◽  
Coupling System ◽  
Psoas Muscles ◽  
Formalin Fixed

In recent years, considerable attention has focused on the morphological nature of the excitation-contraction coupling system of striated muscle. Since the study of Porter and Palade, it has become evident that the sarcoplastic reticulum (SR) and transverse tubules constitute the major elements of this system. The problem still exists, however, of determining the mechamisms by which the signal to interdigitate is presented to the thick and thin myofilaments. This problem appears to center on the movement of Ca++ions between myofilaments and SR. Recently, Philpott and Goldstein reported acid mucosubstance associated with the SR of fish branchial muscle using the colloidal thorium dioxide technique, and suggested that this material may serve to bind or release divalent cations such as Ca++. In the present study, Hale's iron solution adapted to electron microscopy was applied to formalin-fixed myofibrils isolated from glycerol-extracted rabbit psoas muscles and to frozen sections of formalin-fixed rat psoas muscles.

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