scholarly journals Oscillating gradient diffusion MRI reveals unique microstructural information in normal and hypoxia-ischemia injured mouse brains

2014 ◽  
Vol 72 (5) ◽  
pp. 1366-1374 ◽  
Author(s):  
Dan Wu ◽  
Lee J. Martin ◽  
Frances J. Northington ◽  
Jiangyang Zhang
Keyword(s):  
Diffusion Mri ◽  
Gradient Diffusion ◽  
Hypoxia Ischemia

scholarly journals Imaging neurodegeneration in the mouse hippocampus after neonatal hypoxia-ischemia using oscillating gradient diffusion MRI

2013 ◽  
Vol 72 (3) ◽  
pp. 829-840 ◽  
Author(s):  
Manisha Aggarwal ◽  
Jennifer Burnsed ◽  
Lee J. Martin ◽  
Frances J. Northington ◽  
Jiangyang Zhang
Keyword(s):  
Diffusion Mri ◽  
Neonatal Hypoxia ◽  
Gradient Diffusion ◽  
Hypoxia Ischemia ◽  
Mouse Hippocampus

scholarly journals Oscillating-gradient diffusion magnetic resonance imaging detects acute subcellular structural changes in the mouse forebrain after neonatal hypoxia-ischemia

2018 ◽  
Vol 39 (7) ◽  
pp. 1336-1348 ◽  
Author(s):  
Dan Wu ◽  
Lee J Martin ◽  
Frances J Northington ◽  
Jiangyang Zhang
Keyword(s):  
Diffusion Mri ◽  
Structural Changes ◽  
Spatial Scales ◽  
Brain Structures ◽  
Contralateral Side ◽  
Neonatal Hypoxia ◽  
Gradient Diffusion ◽  
Hypoxia Ischemia ◽  
Apparent Diffusion

The recently developed oscillating-gradient diffusion MRI (OG-dMRI) technique extends our ability to examine brain structures at different spatial scales. In this study, we investigated the sensitivity of OG-dMRI in detecting cellular and subcellular structural changes in a mouse model of neonatal hypoxia ischemia (HI). Neonatal mice received unilateral HI injury or sham injury at postnatal day 10, followed by in vivo T2-weighted and diffusion MRI of the brains at 3–6 h and 24 h after HI. Apparent diffusion coefficient (ADC) maps were acquired using conventional pulsed-gradient dMRI (PG-dMRI) and OG-dMRI with oscillating frequencies from 50 to 200 Hz. Pathology at cellular and subcellular levels was evaluated using neuronal, glial, and mitochondrial markers. We found significantly higher rates of ADC increase with oscillating frequencies (Δ fADC) in the ipsilateral edema region, compared to the contralateral side, starting as early as 3 h after HI. Even in injured regions that showed no apparent change in PG-ADC or pseudo-normalized PG-ADC measurements, Δ fADC remained significantly elevated. Histopathology showed swelling of sub-cellular structures in these regions with no apparent whole-cell level change. These results suggest that OG-dMRI is sensitive to subcellular structural changes in the brain after HI and is less susceptible to pseudo-normalization than PG-dMRI.

scholarly journals Probing mouse brain microstructure using oscillating gradient diffusion MRI

2011 ◽  
Vol 67 (1) ◽  
pp. 98-109 ◽  
Author(s):  
Manisha Aggarwal ◽  
Melina V. Jones ◽  
Peter A. Calabresi ◽  
Susumu Mori ◽  
Jiangyang Zhang
Keyword(s):  
Mouse Brain ◽  
Diffusion Mri ◽  
Gradient Diffusion ◽  
Brain Microstructure

Characterizing glioma microenvironment with ultra-high gradient diffusion MRI.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 2050-2050
Author(s):  
Ina Ly ◽  
Barbara Wichtmann ◽  
Susie Yi Huang ◽  
Aapo Nummenmaa ◽  
Ovidiu Andronesi ◽  
...  
Keyword(s):  
Diffusion Model ◽  
Diffusion Mri ◽  
Volume Fraction ◽  
Response To Treatment ◽  
Imaging Biomarker ◽  
Normal Brain ◽  
Post Contrast ◽  
Major Barrier ◽  
High Gradient ◽  
Gradient Diffusion

2050 Background: The infiltrating nature of gliomas, particularly into the peritumoral area, is a major barrier to improving clinical outcome as microscopic disease remains even after apparent gross total resection. Conventional T1 post-contrast and T2/FLAIR MRI do not capture full tumor extent. A better imaging biomarker is needed to improve differentiation between tumor, peritumoral area and normal brain. Methods: 4 pre-surgical patients with non-enhancing, FLAIR-hyperintense lesions suspicious for glioma underwent ultra-high gradient diffusion MRI on the Connectome MRI scanner, a unique scanner with maximum gradient strength of 300 mT/m enabling mapping of cellular microstructures on a micron-level scale. The FLAIR area was defined as the tumor region of interest (ROI). Radiographically normal appearing brain up to 1 cm around the FLAIR area was defined as the peritumoral ROI. Using a novel 3 compartment diffusion model (Linear Multiscale Model), the volume fraction of water (VFW) was calculated within restricted (intracellular), hindered (extracellular) and free (CSF) spaces. VFW in the tumor, peritumoral ROI, contralateral normal white matter (WM) and cortex were compared. Results: Within the tumor ROI, the median VFW in the restricted compartment was decreased vs. the peritumoral ROI (↓ 34%), WM (↓ 46%) and cortex (↓ 18%) while median VFW in the hindered compartment was increased vs. the peritumoral ROI (↑ 26%), WM (↑ 54%) and cortex (↑ 25%). Within the peritumoral ROI, median VFW in the hindered compartment was increased compared to WM (↑ 23%). 3 patients had available histopathology revealing isocitrate dehydrogenase-mutant gliomas. Conclusions: Using ultra-high gradient diffusion MRI and a novel diffusion model, we detected distinct diffusion patterns in the tumor and peritumoral area not seen on conventional MRI. Lower VFW in the restricted compartment within the tumor may reflect decreased intracellular water mobility due to enlarged nuclei. Higher VFW in the hindered compartment in the tumor and peritumoral area may reflect higher degree of tissue permeability and edema. MRI-pathology and larger cohort validation studies are underway to elucidate microenvironment changes in response to treatment.

scholarly journals NIMG-09. CHARACTERIZING GLIOMA MICROENVIRONMENT WITH ULTRA-HIGH GRADIENT DIFFUSION MRI

2017 ◽  
Vol 19 (suppl_6) ◽  
pp. vi144-vi144
Author(s):  
Ina Ly ◽  
Barbara Wichtmann ◽  
Susie Huang ◽  
Aapo Nummenmaa ◽  
Ovidiu Andronesi ◽  
...  
Keyword(s):  
Diffusion Mri ◽  
High Gradient ◽  
Gradient Diffusion ◽  
Glioma Microenvironment

scholarly journals Axon diameter index estimation independent of fiber orientation distribution using high-gradient diffusion MRI

NeuroImage ◽  
2020 ◽  
Vol 222 ◽  
pp. 117197 ◽  
Author(s):  
Qiuyun Fan ◽  
Aapo Nummenmaa ◽  
Thomas Witzel ◽  
Ned Ohringer ◽  
Qiyuan Tian ◽  
...  
Keyword(s):  
Fiber Orientation ◽  
Diffusion Mri ◽  
Orientation Distribution ◽  
Axon Diameter ◽  
High Gradient ◽  
Gradient Diffusion ◽  
Fiber Orientation Distribution ◽  
Index Estimation

scholarly journals High-gradient diffusion MRI reveals distinct estimates of axon diameter index within different white matter tracts in the in vivo human brain

2019 ◽  
Vol 225 (4) ◽  
pp. 1277-1291 ◽  
Author(s):  
Susie Y. Huang ◽  
Qiyuan Tian ◽  
Qiuyun Fan ◽  
Thomas Witzel ◽  
Barbara Wichtmann ◽  
...  
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Diffusion Mri ◽  
Axon Diameter ◽  
White Matter Tracts ◽  
High Gradient ◽  
Gradient Diffusion

scholarly journals Scan-Rescan Repeatability of Axonal Imaging Metrics using High-Gradient Diffusion MRI and Statistical Implications for Study Design

NeuroImage ◽  
2021 ◽  
pp. 118323
Author(s):  
Qiuyun Fan ◽  
Maya N. Polackal ◽  
Qiyuan Tian ◽  
Chanon Ngamsombat ◽  
Aapo Nummenmaa ◽  
...  
Keyword(s):  
Study Design ◽  
Diffusion Mri ◽  
High Gradient ◽  
Gradient Diffusion

Diffusion‐prepared 3D gradient spin‐echo sequence for improved oscillating gradient diffusion MRI

2020 ◽  
Vol 85 (1) ◽  
pp. 78-88
Author(s):  
Dan Wu ◽  
Dapeng Liu ◽  
Yi‐Cheng Hsu ◽  
Haotian Li ◽  
Yi Sun ◽  
...  
Keyword(s):  
Diffusion Mri ◽  
Spin Echo ◽  
Gradient Diffusion ◽  
Spin Echo Sequence
Sign in / Sign up

Export Citation Format

Share Document