T2 Relaxation and Diffusion of Collagen Gel Oriented.

2005 ◽  
Vol 29 (3) ◽  
pp. 347-350
Author(s):  
M. Takeuchi ◽  
M. Sekino ◽  
N. Iriguchi ◽  
S. Ueno
Keyword(s):  
Collagen Gel ◽  
T2 Relaxation ◽  
And Diffusion

Complementary information from multi-exponential T2 relaxation and diffusion tensor imaging reveals differences between multiple sclerosis lesions

NeuroImage ◽  
2008 ◽  
Vol 40 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Shannon H. Kolind ◽  
Cornelia Laule ◽  
Irene M. Vavasour ◽  
David K.B. Li ◽  
Anthony L. Traboulsee ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
T2 Relaxation ◽  
Complementary Information ◽  
And Diffusion

scholarly journals Impact of Xylose on Dynamics of Water Diffusion in Mesoporous Zeolites Measured by NMR

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5518
Author(s):  
Madison L. Nelson ◽  
Joelle E. Romo ◽  
Stephanie G. Wettstein ◽  
Joseph D. Seymour
Keyword(s):  
Pure Water ◽  
Translational Motion ◽  
Mesoporous Structure ◽  
T2 Relaxation ◽  
Structure And Dynamics ◽  
Mesoporous Zeolites ◽  
Starting Point ◽  
Before And After ◽  
5A Zeolite ◽  
And Diffusion

Zeolites are known to be effective catalysts in biomass converting processes. Understanding the mesoporous structure and dynamics within it during such reactions is important in effectively utilizing them. Nuclear magnetic resonance (NMR) T2 relaxation and diffusion measurements, using a high-power radio frequency probe, are shown to characterize the dynamics of water in mesoporous commercially made 5A zeolite beads before and after the introduction of xylose. Xylose is the starting point in the dehydration into furfural. The results indicate xylose slightly enhances rotational mobility while it decreases translational motion through altering the permeability, K, throughout the porous structure. The measurements show xylose inhibits pure water from relocating into larger pores within the zeolite beads where it eventually is expelled from the bead itself.

scholarly journals NI-3 Magnetic resonance relaxometry for tumor cell density imaging for glioma: An exploratory study via 11C-methionine PET and its validation via stereotactic tissue sampling

2021 ◽  
Vol 3 (Supplement_6) ◽  
pp. vi18-vi18
Author(s):  
Manabu Kinoshita ◽  
Masato Uchikoshi ◽  
Souichiro Tateishi ◽  
Shohei Miyazaki ◽  
Mio Sakai ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Tumor Cell ◽  
Cell Density ◽  
T2 Relaxation ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Tumor Load ◽  
The Brain ◽  
And Diffusion ◽  
Met Pet

Abstract Objective: While visualization of non-enhancing tumors for glioma is crucial for planning the most appropriate surgical or non-surgical treatment of the disease, current MRI cannot achieve this goal. This study aims to test the hypothesis that quantitative and diffusion MRI can estimate tumor burden with the brain. Materials and Methods: Study 1: Ten patients who have undergone Methionine PET (Met-PET), quantitative MRI (qMRI), and diffusion MRI (DWI) were included for analysis. A cut-off of a tumor-to-normal ratio (T/Nr) 1.5 was set on Met-PET, and the values from qMRI and DWI were compared. Study 2: Seventy-nine stereo-tactically sampled tissues from 22 glioma patients were correlated with Met-PET, qMRI, and DWI measurements regarding tumor cell density. qMRI acquisition: Imaging was performed on either a 1.5 or 3 T MR scanner (Prisma or Aera; Siemens Healthcare, Erlangen, Germany). T1-relaxometry was achieved by first acquiring MP2RAGE images, then converting those images into T1-relaxation time maps. At the same time, T2-relaxometry was achieved by first acquiring multi-echo T2-weighted images and then converting those images into T2-relaxation time maps, with both relaxometries performed via Bayesian inference modeling (Olea Nova+; Canon Medical Systems, Tochigi, Japan). Results: Study 1 revealed that regions of 1850ms < T1-relaxation time < 3200ms and 115ms < T2-relaxation time < 225ms tended to be Met-PET T/Nr > 1.5. DWI was not useful to separate areas between low and high Met-PET. Study 2 showed that regions of 1850ms < T1-relaxation time < 3200ms showed high tumor cell density than other areas (p=0.04). Conclusions: Our results supported the hypothesis that qMRI is useful for predicting the tumor load within the brain among glioma patients. T1-relaxation time was notably useful for this means. On the other hand, ADC measured from DWI was limited for tumor load prediction.

Molecular Mobility of Unfilled and Carbon-Black-Filled Isoprene Rubber: Proton NMR Transverse Relaxation and Diffusion

2007 ◽  
Vol 80 (5) ◽  
pp. 854-872 ◽  
Author(s):  
Ximei Sun ◽  
Avraam I. Isayev ◽  
Tirtha R. Joshi ◽  
Ernst von Meerwall
Keyword(s):  
Molecular Mobility ◽  
Solid State Nmr ◽  
T2 Relaxation ◽  
Transverse Relaxation ◽  
Network Chain ◽  
Short T2 ◽  
Gradient Diffusion ◽  
And Diffusion ◽  
Relaxation Decay ◽  
Isoprene Rubber

Abstract In an effort to understand the effect of ultrasound on the devulcanization of gum and filled isoprene rubber vulcanizates, solid state NMR 1H transverse relaxation (T2) was employed to analyze rubber molecular mobility. The T2 relaxation decay of the unfilled and the black filled IR was successfully described by a two-component model. The short T2 component arose from the chemically crosslinked (gel) and physically entangled (heavy sol) network. The long T2 decay came from the unentangled sol and dangling network chain ends. Vulcanization decreased the molecular mobility; however, ultrasound devulcanization partially reversed this effect. Addition of processing oil in the filled IR significantly altered the dependence of T2 on the sol fraction. T2 and pulsed-gradient diffusion experiments were carried out on IR melt specimens after sonication with or without subsequent vulcanization. The lowered and broadened M-distribution produced results quantitatively related to earlier work in natural rubber.

Water dynamics in human blood via combined measurements of T2 relaxation and diffusion in the presence of gadolinium

1998 ◽  
Vol 39 (2) ◽  
pp. 223-233 ◽  
Author(s):  
Greg J. Stanisz ◽  
Jonathan G. Li ◽  
Graham A. Wright ◽  
R. Mark Henkelman
Keyword(s):  
Human Blood ◽  
Water Dynamics ◽  
T2 Relaxation ◽  
And Diffusion ◽  
Combined Measurements

scholarly journals A Method for Manufacturing Oncological Phantoms for the Quantification of 18F-FDG PET and DW-MRI Studies

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Francesca Gallivanone ◽  
Irene Carne ◽  
Matteo Interlenghi ◽  
Daniela D’Ambrosio ◽  
Maurizia Baldi ◽  
...  
Keyword(s):  
Fdg Pet ◽  
T2 Relaxation ◽  
Mri Studies ◽  
Adc Values ◽  
3D Printed ◽  
18F Fdg ◽  
New Generation ◽  
And Diffusion ◽  
Mri Measurements ◽  
Normal Background

The aim of this work was to develop a method to manufacture oncological phantoms for quantitation purposes in 18F-FDG PET and DW-MRI studies. Radioactive and diffusion materials were prepared using a mixture of agarose and sucrose radioactive gels. T2 relaxation and diffusion properties of gels at different sucrose concentrations were evaluated. Realistic oncological lesions were created using 3D-printed plastic molds filled with the gel mixture. Once solidified, gels were extracted from molds and immersed in a low-radioactivity gel simulating normal background tissue. A breast cancer phantom was manufactured using the proposed method as an exploratory feasibility study, including several realistic oncological configurations in terms of both radioactivity and diffusion. The phantom was acquired in PET with 18F-FDG, immediately after solidification, and in DW-MRI the following day. Functional volumes characterizing the simulated BC lesions were segmented from PET and DW-MRI images. Measured radioactive uptake and ADC values were compared with gold standards. Phantom preparation was straightforward, and the time schedule was compatible with both PET and MRI measurements. Lesions appeared on 18F-FDG PET and DW-MRI images as expected, without visible artifacts. Lesion functional parameters revealed the phantom’s potential for validating quantification methods, in particular for new generation hybrid PET-MRI systems.

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