MRI contrast agents

2018 ◽  
pp. 63-69
Author(s):  
Kim-Lien Nguyen ◽  
J Paul Finn
Keyword(s):  
Contrast Agents ◽  
Common Factor ◽  
Pulse Sequences ◽  
Negative Contrast ◽  
Positive Contrast ◽  
Mri Contrast Agents ◽  
Magnetic Resonance Imaging Examination ◽  
Hypersensitivity Reactions ◽  
Mri Contrast ◽  
Tissue Contrast

Pharmacologic agents used in the context of a cardiovascular magnetic resonance imaging examination can be divided into three main groups: contrast agents, stress-testing agents (dobutamine, adenosine, regadenoson, dipyridamole), and agents used for treatment of hypersensitivity reactions. The safety of stress agents will be elaborated in the chapter on ischaemic heart disease. This chapter will focus on contrast agents and briefly touch upon medications used in the setting of hypersensitivity reactions. Contrast agents are used to further augment tissue contrast and have become an integral component of cardiovascular imaging. These agents typically exert strong T1 shortening (gadolinium or manganese chelates, positive contrast) or T2 shortening (iron oxide particles, negative contrast). In some cases, very small iron particles may produce enhancement on either T1- or T2-weighted pulse sequences. The common factor lies in the paramagnetic properties of the material when exposed to an external magnetic field. The largest group of compounds consists of gadolinium-based contrast agents (GBCAs). Since the first description of nephrogenic systemic fibrosis in patients with renal insufficiency in 2000, and subsequent alerts by the US Food and Drug Administration and the European Medicines Association, interest in the safety of GBCAs has increased, along with concerted efforts to seek alternative contrast agents. Overall however, GBCAs are well tolerated.

Paramagnetic and Superparamagnetic Inorganic Nanoparticles for T1-Weighted Magnetic Resonance Imaging

2018 ◽  
Vol 25 (25) ◽  
pp. 2970-2986 ◽  
Author(s):  
Leyong Zeng ◽  
Di Wu ◽  
Ruifen Zou ◽  
Tianxiang Chen ◽  
Jinchao Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Negative Contrast ◽  
Positive Contrast ◽  
Mri Contrast Agents ◽  
Inorganic Nanoparticles ◽  
Oxide Nanoparticles ◽  
Resonance Imaging ◽  
Mri Contrast

Magnetic resonance imaging (MRI) has become a promising technique in the early diagnosis of cancers, especially the application of contrast agents can further enhance the detection limit. Compared with the dark signal in “negative” contrast agents (T2), “positive” contrast agents (T1) with bright signal are more desirable for high-resolution imaging. However, the clinically used gadolinium complexes have short circulation time and the risk of nephrogenic system fibrosis. Therefore, to overcome the disadvantage of T2 agents and traditional T1 agents, it is very interesting to develop nano-scaled T1-weighted MRI contrast agents with safer and more precise imaging performance. The present review systematically summarized the recent progress of paramagnetic and superparamagnetic inorganic nanoparticles as T1-weighted MRI contrast agents, including gadolinium oxide nanoparticles, gadoliniumbased upconversion nanoparticles, manganese oxide nanoparticles, and ultra-small iron oxide nanoparticles. Moreover, we also described their applications in multi-modal imaging and visualized theranostics.

scholarly journals Synthesis, Characterizations, and 9.4 Tesla T2 MR Images of Polyacrylic Acid-Coated Terbium(III) and Holmium(III) Oxide Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1355
Author(s):  
Shanti Marasini ◽  
Huan Yue ◽  
Son Long Ho ◽  
Ji Ae Park ◽  
Soyeon Kim ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Polyacrylic Acid ◽  
Colloidal Stability ◽  
Negative Contrast ◽  
Mri Contrast Agents ◽  
Mr Images ◽  
Mri Contrast ◽  
3.0 T ◽  
Magnetic Resonance Imaging Mri

Polyacrylic acid (PAA)-coated lanthanide oxide (Ln2O3) nanoparticles (NPs) (Ln = Tb and Ho) with high colloidal stability and good biocompatibility were synthesized, characterized, and investigated as a new class of negative (T2) magnetic resonance imaging (MRI) contrast agents at high MR fields. Their r2 values were appreciable at a 3.0 T MR field and higher at a 9.4 T MR field, whereas their r1 values were negligible at all MR fields, indicating their exclusive induction of T2 relaxations with negligible induction of T1 relaxations. Their effectiveness as T2 MRI contrast agents at high MR fields was confirmed from strong negative contrast enhancements in in vivo T2 MR images at a 9.4 T MR field after intravenous administration into mice tails.

Cubosomes as Carriers for MRI Contrast Agents

2017 ◽  
Vol 24 (5) ◽  
pp. 470-482 ◽  
Author(s):  
Nicolas Alcaraz ◽  
Ben J. Boyd
Keyword(s):  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast

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 Correction to: Magnetic Nanoparticles as MRI Contrast Agents

2021 ◽  
Vol 379 (4) ◽  
Author(s):  
Ashish Avasthi ◽  
Carlos Caro ◽  
Esther Pozo-Torres ◽  
Manuel Pernia Leal ◽  
María Luisa García-Martín
Keyword(s):  
Magnetic Nanoparticles ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast

A correction to this paper has been published: https://doi.org/10.1007/s41061-021-00340-y

One-Step Synthesis of Single-Stranded DNA-Bridged Iron Oxide Supraparticles as MRI Contrast Agents

Nano Letters ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2793-2799
Author(s):  
Jingfang Zhang ◽  
Zhenghan Di ◽  
Husheng Yan ◽  
Yuliang Zhao ◽  
Lele Li
Keyword(s):  
Iron Oxide ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Single Stranded Dna ◽  
Mri Contrast ◽  
One Step

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 Defining the conditions for the development of the emerging class of FeIII-based MRI contrast agents

2021 ◽  
Author(s):  
Zsolt Baranyai ◽  
Fabio Carniato ◽  
Alessandro Nucera ◽  
Dávid Horváth ◽  
Lorenzo Tei ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Model Systems ◽  
Mri Contrast

An integrated 1H and 17O NMR relaxometric study on model systems allowed to highlight that the Fe(III) complexes might represent the best alternative to Gd-based MRI contrast agents at the magnetic fields of current and future clinical scanners.

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