scholarly journals Zonal differences in meniscus MR relaxation times in response to in vivo static loading in knee osteoarthritis

2015 ◽  
Vol 34 (2) ◽  
pp. 249-261 ◽  
Author(s):  
Nathaniel E. Calixto ◽  
Deepak Kumar ◽  
Karupppasamy Subburaj ◽  
Justin Singh ◽  
Joseph Schooler ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Static Loading ◽  
Relaxation Times ◽  
Mr Relaxation

scholarly journals Changes in MR relaxation times of the meniscal body with loading: an in vivo pilot study in knee osteoarthritis

2013 ◽  
Vol 21 ◽  
pp. S213
Author(s):  
K. Subburaj ◽  
R.B. Souza ◽  
B.T. Wyman ◽  
X. Li ◽  
T.M. Link ◽  
...  
Keyword(s):  
Pilot Study ◽  
Knee Osteoarthritis ◽  
Relaxation Times ◽  
Mr Relaxation

scholarly journals Changes in MR relaxation times of the meniscus with acute loading: An in vivo pilot study in knee osteoarthritis

2013 ◽  
Vol 41 (2) ◽  
pp. 536-543 ◽  
Author(s):  
Karupppasamy Subburaj ◽  
Richard B. Souza ◽  
Bradley T. Wyman ◽  
Marie-Pierre Hellio Le Graverand-Gastineau ◽  
Xiaojuan Li ◽  
...  
Keyword(s):  
Pilot Study ◽  
Knee Osteoarthritis ◽  
Relaxation Times ◽  
Mr Relaxation

scholarly journals P281 RELATIONSHIP OF IN VIVO MR T1RHO AND T2 RELAXATION TIMES IN CARTILAGE WITH KNEE OSTEOARTHRITIS

2006 ◽  
Vol 14 ◽  
pp. S154
Author(s):  
X. Li ◽  
S. Kazzaz ◽  
D. Castillo ◽  
G. Blumenkrantz ◽  
C.B. Ma ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Relaxation Times ◽  
T2 Relaxation ◽  
Relationship Of

scholarly journals Gd3+-Asparagine-Anionic Linear Globular Dendrimer Second-Generation G2 Complexes: Novel Nanobiohybrid Theranostics

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Nasim Hashempour Alamdari ◽  
Mahmood Alaei-Beirami ◽  
Seyed Ataollah Sadat Shandiz ◽  
Hadi Hejazinia ◽  
Rahimeh Rasouli ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Relaxation Times ◽  
Cost Effective ◽  
Water Soluble ◽  
Brain Targeting ◽  
Tumor Growth Inhibition ◽  
Effective Agent ◽  
Water Soluble Polymer ◽  
Mr Relaxation

Designing a unique theranostic biocompatible, biodegradable, and cost-effective agent which is easy to be synthesized as a biohybrid material was the aim of this study. In this matter, asparagine attached to anionic linear globular dendrimer G2 (as a biocompatible, biodegradable, and cost-effective agent which is negatively charged nanosized and water soluble polymer that outweighs other traditionally used dendrimers) and finally contrast agent (Gd3+) was loaded (which made complexes) in synthesized asparagine-dendrimer. Observations revealed that, in addition to successful colon cancer and brain targeting, Gd3+-dendrimer-asparagine, the proposed theranostic agent, could increase T1 MR relaxation times, decrease T2 MR relaxation times significantly, and improve contrast of image as well as illustrating good cellular uptake based on florescent microscopy/flow cytometry and ICP-mass data. In addition to that, it increased tumor growth inhibition percentage (TGI%) significantly compared to FDA approved contrast agent, Magnevist. Totally, Gd3+-anionic linear globular dendrimer G2-asparagine could be introduced to the cancer imaging/therapy (theranostics) protocols after in vivo MR and fluorescent analysis and passing clinical trials. Hence, this nanotheranostic agent would be a promising candidate for brain drug delivery and imaging in the future.

scholarly journals Whole-brain 3D MR fingerprinting brain imaging: clinical validation and feasibility to patients with meningioma

2021 ◽  
Author(s):  
Thomaz R. Mostardeiro ◽  
Ananya Panda ◽  
Robert J. Witte ◽  
Norbert G. Campeau ◽  
Kiaran P. McGee ◽  
...  
Keyword(s):  
White Matter ◽  
Statistical Significance ◽  
Relaxation Times ◽  
Brain Structures ◽  
Centrum Semiovale ◽  
In Vivo Evaluation ◽  
Whole Brain ◽  
Mean Values ◽  
Caudate Head

Abstract Purpose MR fingerprinting (MRF) is a MR technique that allows assessment of tissue relaxation times. The purpose of this study is to evaluate the clinical application of this technique in patients with meningioma. Materials and methods A whole-brain 3D isotropic 1mm3 acquisition under a 3.0T field strength was used to obtain MRF T1 and T2-based relaxometry values in 4:38 s. The accuracy of values was quantified by scanning a quantitative MR relaxometry phantom. In vivo evaluation was performed by applying the sequence to 20 subjects with 25 meningiomas. Regions of interest included the meningioma, caudate head, centrum semiovale, contralateral white matter and thalamus. For both phantom and subjects, mean values of both T1 and T2 estimates were obtained. Statistical significance of differences in mean values between the meningioma and other brain structures was tested using a Friedman’s ANOVA test. Results MR fingerprinting phantom data demonstrated a linear relationship between measured and reference relaxometry estimates for both T1 (r2 = 0.99) and T2 (r2 = 0.97). MRF T1 relaxation times were longer in meningioma (mean ± SD 1429 ± 202 ms) compared to thalamus (mean ± SD 1054 ± 58 ms; p = 0.004), centrum semiovale (mean ± SD 825 ± 42 ms; p < 0.001) and contralateral white matter (mean ± SD 799 ± 40 ms; p < 0.001). MRF T2 relaxation times were longer for meningioma (mean ± SD 69 ± 27 ms) as compared to thalamus (mean ± SD 27 ± 3 ms; p < 0.001), caudate head (mean ± SD 39 ± 5 ms; p < 0.001) and contralateral white matter (mean ± SD 35 ± 4 ms; p < 0.001) Conclusions Phantom measurements indicate that the proposed 3D-MRF sequence relaxometry estimations are valid and reproducible. For in vivo, entire brain coverage was obtained in clinically feasible time and allows quantitative assessment of meningioma in clinical practice.

Knee Cartilage T 2 Relaxation Times 3 Months after ACL Reconstruction Are Associated with Knee Gait Variables Linked to Knee Osteoarthritis

2021 ◽  
Author(s):  
Jack R. Williams ◽  
Kelsey Neal ◽  
Abdulmajeed Alfayyadh ◽  
Kendra Lennon ◽  
Jacob J. Capin ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Acl Reconstruction ◽  
Relaxation Times ◽  
Knee Cartilage

Abstract 403: Tracking the Migration of Porcine Mesenchymal Stem Cells with the MRI Contrast Agent Ferex in an AAA Model

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Rami Tadros ◽  
Bhakti Rawal ◽  
Karen Briley-Saebo ◽  
David O’Connor ◽  
Dan Han ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Contrast Agent ◽  
Lentiviral Vector ◽  
Relaxation Times ◽  
Mri Contrast Agent ◽  
Signal Loss ◽  
Post Transplantation ◽  
Mri Contrast

Introduction: Mesenchymal stem cells (MSC) are being investigated in porcine abdominal aortic aneurysm (PAAA) models for their repair potential. This study uses MSCs labeled with the MRI contrast agent Ferex to non-invasively evaluate MSC migration in-vivo. Methods: MSCs from 6 pigs were isolated from bone marrow via Ficoll Paque separation and expanded in culture. Using a Lentiviral vector, MSC from all 6 pigs were transfected with green florescent protein (GFP). MSCs from 4 of these pigs were also labeled with 200μg/ml Ferex using Poly-L-Lysine and then analyzed for Ferex uptake and viability. Preservation of the MSC phenotype was confirmed using flow cytometry by detecting positive CD90 and negative CD45 and CD117. Transmission electron microscopy established that Ferex localized to lysosomes. MSCs were then injected into the adventitia of the PAAA. In-vivo MRI was performed using multiple echo gradient echo sequences. Effective transverse relaxation times (T2* values) were calculated on a pixel-by-pixel basis as a function of time post cell transplantation. Results: Ferex labeled MSCs were visible post transplantation at 4, 11, 15 and 21 days using MRI. The MRI signal void (decreased T2* values) correlated with the presence of Ferex within the PAAA. This signal loss progressively expanded circumferentially at each study interval representing cellular movement. MSC migration and localization were confirmed with GFP visualization on fluorescence microscopy and immunohistochemistry. In-vivo MRI signals also correlate with iron deposition on Perl’s stain. Conclusion: Ferex can be used as an in-vivo tracking agent of MSCs in PAAA models.

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