scholarly journals Dynamic, Simultaneous Concentration Mapping of Multiple MRI Contrast Agents with Dual Contrast - Magnetic Resonance Fingerprinting

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christian E. Anderson ◽  
Mette Johansen ◽  
Bernadette O. Erokwu ◽  
He Hu ◽  
Yuning Gu ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Contrast Agents ◽  
Ex Vivo ◽  
Single Agent ◽  
Mri Contrast Agents ◽  
Mri Contrast Agent ◽  
Spatiotemporal Resolution ◽  
Mri Contrast ◽  
Contrast Magnetic Resonance

AbstractSynchronous assessment of multiple MRI contrast agents in a single scanning session would provide a new “multi-color” imaging capability similar to fluorescence imaging but with high spatiotemporal resolution and unlimited imaging depth. This multi-agent MRI technology would enable a whole new class of basic science and clinical MRI experiments that simultaneously explore multiple physiologic/molecular events in vivo. Unfortunately, conventional MRI acquisition techniques are only capable of detecting and quantifying one paramagnetic MRI contrast agent at a time. Herein, the Dual Contrast – Magnetic Resonance Fingerprinting (DC-MRF) methodology was extended for in vivo application and evaluated by simultaneously and dynamically mapping the intra-tumoral concentration of two MRI contrast agents (Gd-BOPTA and Dy-DOTA-azide) in a mouse glioma model. Co-registered gadolinium and dysprosium concentration maps were generated with sub-millimeter spatial resolution and acquired dynamically with just over 2-minute temporal resolution. Mean tumor Gd and Dy concentration measurements from both single agent and dual agent DC-MRF studies demonstrated significant correlations with ex vivo mass spectrometry elemental analyses. This initial in vivo study demonstrates the potential for DC-MRF to provide a useful dual-agent MRI platform.

scholarly journals Study on Establishing Reference Safe Concentrations of MRI Contrast Agents for Optimized Images: Paramagnetic Gd-DTPA-BMEA and Superparamagnetic Ferucarbotran

2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast Agent ◽  
In Vitro Experiments ◽  
Mri Contrast ◽  
In Vivo Experiments ◽  
Contrast Agent Injection

The purpose of this study is to establish the minimal injection doses of magnetic resonance imaging (MRI) contrast agents that can achieve optimized images while improving the safety of injectable MRI drugs. Gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) and ferucarbotran, commonly used in clinical practice, were selected and evaluated with in vitro and in vivo experiments. MRI was acquired using T1-weighted (T1W) and T2-weighted (T2W) sequences, and the results were quantitatively analyzed. For in vitro experiments, results showed that T1W and T2W images were optimal when Gd-DTPA-bisamide (2-oxoethyl) (Gd-DTPA-BMEA) and ferucarbotran were diluted to a volume percentage of 0.6% and 0.05%; all comparisons were significant differences in grayscale statistics using one-way analysis of variance (ANOVA). For in vivo experiments, the contrast agent with optimal concentration percentages determined from in vitro experiments were injected into mice with an injection volume of 100 μL, and the images of brain, heart, liver, and mesentery before and after injection were compared. The statistical results showed that the p values of both T1W and T2W were less than 0.001, which were statistically significant. Under safety considerations for MRI contrast agent injection, optimized MRI images could still be obtained after reducing the injection concentration, which can provide a reference for the safety concentrations of MRI contrast agent injection in the future.

scholarly journals A Photocleavable Contrast Agent for Light-Responsive MRI

2020 ◽  
Vol 13 (10) ◽  
pp. 296
Author(s):  
Friederike Reeßing ◽  
Sèvrin E. M. Huijsse ◽  
Rudi A. J. O. Dierckx ◽  
Ben L. Feringa ◽  
Ronald J.H. Borra ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast Agent ◽  
Whole Body ◽  
Spatiotemporal Resolution ◽  
Mri Contrast ◽  
High Relaxivity ◽  
Vis Spectroscopy ◽  
Clinical Mri

Thanks to its innocuousness and high spatiotemporal resolution, light is used in several established and emerging applications in biomedicine. Among them is the modulation of magnetic resonance imaging (MRI) contrast agents’ relaxivity with the aim to increase the sensitivity, selectivity and amount of functional information obtained from this outstanding whole-body medical imaging technique. This approach requires the development of molecular contrast agents that show high relaxivity and strongly pronounced photo-responsiveness. To this end, we report here the design and synthesis of a light-activated MRI contrast agent, together with its evaluation using UV–vis spectroscopy, Fast Field Cycling (FFC) relaxometry and relaxometric measurements on clinical MRI scanners. The high relaxivity of the reported agent changes substantially upon irradiation with light, showing a 17% decrease in relaxivity at 0.23T upon irradiation with λ = 400 nm (violet) light for 60 min. On clinical MRI scanners (1.5T and 3.0T), irradiation leads to a decrease in relaxivity of 9% and 19% after 3 and 60 min, respectively. The molecular design presents an important blueprint for the development of light-activatable MRI contrast agents.

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.

Investigation of cyano-bridged coordination nanoparticles Gd3+/[Fe(CN)6]3−/d-mannitol as T1-weighted MRI contrast agents

Nanoscale ◽  
2015 ◽  
Vol 7 (28) ◽  
pp. 11899-11903 ◽  
Author(s):  
M. Perrier ◽  
A. Gallud ◽  
A. Ayadi ◽  
S. Kennouche ◽  
C. Porredon ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Resonance Imaging ◽  
Mri Contrast

Ultra small Gd3+/[Fe(CN)6]3− nanoparticles are investigated in vivo as contrast agents for Magnetic Resonance Imaging.

scholarly journals Iron Oxide as an Mri Contrast Agent for Cell Tracking: Supplementary Issue

2015 ◽  
Vol 8s1 ◽  
pp. MRI.S23557 ◽  
Author(s):  
Daniel J. Korchinski ◽  
May Taha ◽  
Runze Yang ◽  
Nabeela Nathoo ◽  
Jeff F. Dunn
Keyword(s):  
Iron Oxide ◽  
Contrast Agents ◽  
Cell Tracking ◽  
Ex Vivo ◽  
Cerebral Aneurysms ◽  
Cell Types ◽  
Mri Contrast Agent ◽  
Mri Contrast ◽  
Different Cell Types

Iron oxide contrast agents have been combined with magnetic resonance imaging for cell tracking. In this review, we discuss coating properties and provide an overview of ex vivo and in vivo labeling of different cell types, including stem cells, red blood cells, and monocytes/macrophages. Furthermore, we provide examples of applications of cell tracking with iron contrast agents in stroke, multiple sclerosis, cancer, arteriovenous malformations, and aortic and cerebral aneurysms. Attempts at quantifying iron oxide concentrations and other vascular properties are examined. We advise on designing studies using iron contrast agents including methods for validation.

scholarly journals MRI Contrast Agent-Based Multifunctional Materials: Diagnosis and Therapy

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Hyeona Yim ◽  
Seogjin Seo ◽  
Kun Na
Keyword(s):  
Contrast Agents ◽  
In Vivo Imaging ◽  
Mri Contrast Agents ◽  
Mri Contrast Agent ◽  
Resonance Imaging ◽  
Mri Contrast ◽  
Agent Based ◽  
Diagnosis And Therapy ◽  
Magnetic Resonance Imaging Mri

Various imaging technologies have become increasingly important in developing a better understanding of information on the biological and clinical phenomena associated with diseases of interest. Of these technologies, magnetic resonance imaging (MRI) is one of the most powerful for clinical diagnosis and in vivo imaging without the exposure to ionising radiation or radiotracers. Despite its many advantages, there are intrinsic limitations caused by MRI contrast agents, such as short vascular half-life circulation, which lead to unwanted side effects. In this review, we will focus on the multifunctional modification of MRI contrast agents for diagnosis and therapy.

scholarly journals A Review on the Optimal Design of Magnetic Nanoparticle-Based T2 MRI Contrast Agents

2020 ◽  
Vol 6 (1) ◽  
pp. 11 ◽  
Author(s):  
Nina Kostevšek
Keyword(s):  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Superparamagnetic Nanoparticles ◽  
Mri Contrast Agent ◽  
Active Components ◽  
Future Directions ◽  
Mri Contrast ◽  
Foreign Substance ◽  
Optimal Surface

Relaxivity r2 and thus the contrast efficacy of superparamagnetic nanoparticles (NPs) can be enhanced via either NP’s magnetic properties or coating optimization. Numerous reports can be found about the investigation of the optimal iron oxide nanoparticles (IO NPs) size, shape, crystallinity and composition that yield high saturation magnetization (ms) values and, consequently, high r2 values. Although the use of an appropriate coating can boost up the NPs MRI contrast agent efficiency, this topic has been largely understudied. Therefore, in this review, the factors affording r2 enhancement of spherical magnetic NPs are discussed. Based on the literature, the requirements for an optimal surface coating that may increase r2 values and ensure stability and biocompatibility of NPs are listed. One of the best candidates that fulfil these requirements are liposomes with embedded magnetic NPs, so-called magneto-liposomes. The analysis of the literature elucidated the most appropriate phospholipid compositions for the relaxivity enhancement and for magneto-liposomes in vivo stability. Finally, the future directions in the development of NP-based contrast agents are given. For example, most of the synthetic NPs are recognized and eliminated as a foreign substance by the immune system. To overcome this issue, a design of a biomimetic, cell-membrane-based nanocarrier for contrast agents is proposed. Disguised with cell membranes, NPs or other active components can act as autogenous cells and thus ensure the inherent biocompatibility.

HP-DO3A-based amphiphilic MRI contrast agents and relaxation enhancement through their assembly with polyelectrolytes

2016 ◽  
Vol 4 (45) ◽  
pp. 7241-7248 ◽  
Author(s):  
Qin Zhu ◽  
Heng Yang ◽  
Yuanyuan Li ◽  
Yu Tian ◽  
Wei Wang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Self Assembly ◽  
Mri Contrast Agents ◽  
Resonance Imaging ◽  
Mri Contrast ◽  
Good Biocompatibility ◽  
Magnetic Resonance Imaging Mri

HP-DO3A-based amphiphilic magnetic resonance imaging (MRI) contrast agents show electrostatic self-assembly ability with polyelectrolytes, good biocompatibility, and significant contrast enhancement in in vivo imaging.

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...

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