scholarly journals Ln(iii)-complexes of a DOTA analogue with an ethylenediamine pendant arm as pH-responsive PARACEST contrast agents

2016 ◽  
Vol 45 (8) ◽  
pp. 3486-3496 ◽  
Author(s):  
T. Krchová ◽  
A. Gálisová ◽  
D. Jirák ◽  
P. Hermann ◽  
J. Kotek
Keyword(s):  
Contrast Agents ◽  
Magnetization Transfer ◽  
Magnetization Transfer Ratio ◽  
Ph Responsive ◽  
Resonance Imaging ◽  
Biologically Relevant ◽  
Pendant Arm ◽  
Ratio Approach ◽  
Magnetic Resonance Imaging Mri ◽  
Ph Range

New contrast agents useful for pH determination (in the biologically relevant pH range) by Magnetic Resonance Imaging (MRI) using magnetization transfer ratio approach are presented.

Biocompatible dextran-coated gadolinium-doped cerium oxide nanoparticles as MRI contrast agents with high T1 relaxivity and selective cytotoxicity to cancer cells

2021 ◽  
Author(s):  
Anton Popov ◽  
Maxim Artemovich Abakumov ◽  
Irina Savintseva ◽  
Artem Ermakov ◽  
Nelly Popova ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Resonance Imaging ◽  
Mri Contrast ◽  
Selective Cytotoxicity ◽  
Magnetic Resonance Imaging Mri

Gd-based complexes are widely used as magnetic resonance imaging (MRI) contrast agents. The safety of previously approved contrast agents is questionable and is being re-assessed. The main causes of concern...

scholarly journals Effect of Gd and Dy Concentrations in Layered Double Hydroxides on Contrast in Magnetic Resonance Imaging

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 462 ◽  
Author(s):  
Karina Nava Andrade ◽  
Gregorio Guadalupe Carbajal Arízaga ◽  
José Antonio Rivera Mayorga
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Resonance Imaging ◽  
Mri Contrast ◽  
Molar Ratios ◽  
Magnetic Resonance Imaging Mri ◽  
Double Hydroxide ◽  
Double Hydroxides

In this work, we explore the synthesis of layered double hydroxide (LDH) particles containing different molar ratios of Gd3+ and Dy3+ cations. A single crystalline phase was obtained for Zn2.0Al0.75Gd0.125Dy0.125-LDH and Zn2.0Al0.5Gd0.25Dy0.25-LDH, and their efficiency as contrast agents was evaluated by T1- and T2-weighted magnetic resonance imaging (MRI). Both GdDy-LDHs exhibited longitudinal relaxivity (r1) higher than a commercial reference. The highest contrast in the T1 mode was achieved with the Zn2.0Al0.75Gd0.125Dy0.125-LDH, which contained the lowest concentration of lanthanides; this efficiency is related to the lowest amount of carbonate anions complexing the lanthanide sites. On the contrary, the best contrast in the T2 mode was achieved with Zn2.0Al0.5Gd0.25Dy0.25-LDH. Zn2.0Al0.75Gd0.125Dy0.125-LDH and Zn2.0Al0.5Gd0.25Dy0.25-LDH presented r2/r1 ratios of 7.9 and 22.5, respectively, indicating that the inclusion of gadolinium and dysprosium into layered structures is a promising approach to the development of efficient bimodal (T1/T2) MRI contrast agents.

Occurrence and microstructural features of slowly expanding lesions on fingolimod or natalizumab treatment in multiple sclerosis

2020 ◽  
pp. 135245852096910
Author(s):  
Paolo Preziosa ◽  
Elisabetta Pagani ◽  
Lucia Moiola ◽  
Mariaemma Rodegher ◽  
Massimo Filippi ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Signal Intensity ◽  
Linear Models ◽  
Magnetization Transfer ◽  
Brain Magnetic Resonance Imaging ◽  
White Matter Lesions ◽  
Magnetization Transfer Ratio ◽  
Treatment Groups ◽  
Natalizumab Treatment ◽  
Magnetic Resonance Imaging Mri

Background: In multiple sclerosis (MS), up to 57% of white matter lesions are chronically active. These slowly expanding lesions (SELs) contribute to disability progression. Objective: The aim of this study is to compare fingolimod and natalizumab effects on progressive linearly enlarging lesions (i.e. SELs), a putative biomarker of smouldering inflammation. Methods: Relapsing-remitting MS patients starting fingolimod ( n = 24) or natalizumab ( n = 28) underwent 3T brain magnetic resonance imaging (MRI) at baseline, months 6, 12 and 24. SELs were identified among baseline-visible lesions showing ⩾ 12.5% of annual increase, calculated by linearly fitting the Jacobian of the nonlinear deformation field between timepoints obtained combining T1- and T2-weighted scans. SEL burden, magnetization transfer ratio (MTR) and T1 signal intensity were compared using linear models. Results: The prevalences of fingolimod (75%) and natalizumab patients (46%) with ⩾ 1 SEL were not significantly different (adjusted- p = 0.08). Fingolimod group had higher SEL number and volume (adjusted- p ⩽ 0.047, not false discovery rate (FDR) survived). In both groups, SELs versus non-SELs showed lower MTR and T1 signal intensity (adjusted- p ⩽ 0.01, FDR-survived). Longitudinally, non-SEL MTR increased in both treatment groups (adjusted- p ⩽ 0.005, FDR-survived). T1 signal intensity decreased in SELs with both treatments (adjusted- p ⩽ 0.049, FDR-survived in fingolimod group) and increased in natalizumab non-SELs (adjusted- p = 0.03, FDR-survived). Conclusion: The effects of natalizumab and fingolimod on SEL occurrence seem modest, with natalizumab being slightly more effective. Both treatments may promote reparative mechanisms in stable or chronic inactive lesions.

scholarly journals Ferritin: A Platform for MRI Contrast Agents Delivery

Inorganics ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 33 ◽  
Author(s):  
Maria Ruggiero ◽  
Diego Alberti ◽  
Valeria Bitonto ◽  
Simonetta Geninatti Crich
Keyword(s):  
Magnetic Resonance Imaging ◽  
Targeted Therapy ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Resonance Imaging ◽  
Mri Contrast ◽  
Magnetic Resonance Imaging Mri ◽  
Accurate Imaging ◽  
Unique Surface

The search for high relaxivities and increased specificity continues to be central to the development of paramagnetic contrast agents for magnetic resonance imaging (MRI). Ferritin, due to its unique surface properties, architecture, and biocompatibility, has emerged as a natural nanocage that can potentially help to reach both these goals. This review aims to highlight recent advances in the use of ferritin as a nanoplatform for the delivery of metal-based MRI contrast agents (containing Gd3+, Mn2+, or Fe2O3) alone or in combination with active molecules used for therapeutic purposes. The collected results unequivocally show that the use of ferritin for contrast agent delivery leads to more accurate imaging of cancer cells and a significantly improved targeted therapy.

scholarly journals Uniform Fe3O4/Gd2O3-DHCA nanocubes for dual-mode magnetic resonance imaging

2020 ◽  
Vol 11 ◽  
pp. 1000-1009
Author(s):  
Miao Qin ◽  
Yueyou Peng ◽  
Mengjie Xu ◽  
Hui Yan ◽  
Yizhu Cheng ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Clinical Diagnostics ◽  
Resonance Imaging ◽  
Dual Mode ◽  
Mri Contrast ◽  
Magnetic Resonance Imaging Mri

The multimodal magnetic resonance imaging (MRI) technique has been extensively studied over the past few years since it offers complementary information that can increase diagnostic accuracy. Simple methods to synthesize contrast agents are necessary for the development of multimodal MRI. Herein, uniformly distributed Fe3O4/Gd2O3 nanocubes for T 1–T 2 dual-mode MRI contrast agents were successfully designed and synthesized. In order to increase hydrophilicity and biocompatibility, the nanocubes were coated with nontoxic 3,4-dihydroxyhydrocinnamic acid (DHCA). The results show that iron (Fe) and gadolinium (Gd) were homogeneously distributed throughout the Fe3O4/Gd2O3-DHCA (FGDA) nanocubes. Relaxation time analysis was performed on the images obtained from the 3.0 T scanner. The results demonstrated that r 1 and r 2 maximum values were 67.57 ± 6.2 and 24.2 ± 1.46 mM−1·s−1, respectively. In vivo T 1- and T 2-weighted images showed that FGDA nanocubes act as a dual-mode contrast agent enhancing MRI quality. Overall, these experimental results suggest that the FGDA nanocubes are interesting tools that can be used to increase MRI quality, enabling accurate clinical diagnostics.

Investigations of the Horse Conceptus Via Magnetic Resonance Imaging (Mri) and Nitroxide Spin Labels as Contrast Agents

1990 ◽  
Vol 9 (3-6) ◽  
pp. 391-397 ◽  
Author(s):  
Uwe M. Oehler ◽  
Edward G. Janzen ◽  
Keith Betteridge ◽  
Colin Fyfet ◽  
Rheal A. Towner ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Spin Labels ◽  
Resonance Imaging ◽  
Nitroxide Spin Labels ◽  
Magnetic Resonance Imaging Mri
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