The Use of Gadolinium in Musculoskeletal MRI—Time to Rethink?

AbstractMagnetic resonance imaging has continued to evolve over the recent decades, in part, due to the evolution of gadolinium-based contrast agents and their use. These were initially thought to have a relatively low-risk profile. However, there is mounting evidence that trace amounts of gadolinium are retained within the body. To ascertain the current use of gadolinium in medical practice, we performed a survey of musculoskeletal radiologists, within the United Kingdom, Europe and India. The survey demonstrated varied practices amongst all radiologists with relatively indiscriminate use of gadolinium. In this review, we discuss the current evidence for and against the use of gadolinium in musculoskeletal magnetic resonance imaging.

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Value of contrast-enhanced Magnetic Resonance Imaging (MRI) in the diagnosis of breast cancer

Mini-Reviews in Medicinal Chemistry ◽

10.2174/1389557521666210521113155 ◽

2021 ◽

Vol 21 ◽

Author(s):

Mateus Aquino Gonçalves ◽

Bruna Pereira ◽

Camila Tavares ◽

Taináh Martins ◽

Elaine Cunha ◽

...

Keyword(s):

Breast Cancer ◽

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Contrast Agents ◽

Eating Habits ◽

The Body ◽

Resonance Imaging ◽

Hydrogen Atoms ◽

Body Tissues ◽

Magnetic Resonance Imaging Mri

: This review article aims to address the main features of breast cancer. Thus, the general aspects of this disease have been shown since the first evidence of breast cancer in the world until the numbers today. In this way, there are some ways to prevent breast cancer, such as the woman's lifestyle (healthy eating habits and physical activities) that helps to reduce the incidence of this anomaly. The first noticeable symptom of this anomaly is typically a lump that feels different from the rest of the breast tissue. More than 80% of breast cancer are discovered when the woman feels a lump being present and about 90% of the cases, the cancer is noticed by the woman herself. Currently, the most used method for the detection of cancer and other injuries is the Magnetic Resonance Imaging (MRI) technique. This technique has been shown to be very effective, however, for a better visualization of the images, contrast agents (CAs) are used, which are paramagnetic compounds capable of increasing the relaxation of the hydrogen atoms of the water molecules present in the body tissues. The most used CAs are Gd3+ complexes, although they are very efficient, they are toxic to the organism. Thus, new contrast agents have been studied to replace Gd3+ complexes, we can mention iron oxides as a promising substitute.

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Amphiphilic branched polymeric nitroxides for efficient magnetic resonance imaging of multiple-object in vivo

10.21203/rs.3.rs-154115/v1 ◽

2021 ◽

Author(s):

Xiaoming Wang ◽

Shiwei Guo ◽

Zhiqian Li ◽

Qiang Luo ◽

Yan Dai ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Contrast Agents ◽

Cardiovascular System ◽

Water Environment ◽

Mri Contrast Agents ◽

The Body ◽

Resonance Imaging ◽

Cas A

Abstract Background: In order to solve the potential toxicity of metal-based Magnetic resonance imaging (MRI) contrast agents (CAs), a concept of non-metallic MRI CAs has emerged. Currently, paramagnetic nitroxides (such as (2, 2, 5, 5-tetramethylpyrrolidine-1-oxyl, PROXYL), (2, 2, 6, 6-tetramethylpiperidine-1-oxide, TEMPO), etc.) are being extensively studied because their good stability and imaging mechanism are similar to metal based contrast agents (such as Gd3+ chelate-based clinical CAs). However, nitroxides lower relaxivity and metabolizes rapidly in vivo are still challenge. Previous researches have proven that the construction of macromolecular nitroxides contrast agents (mORCAs) is a promising solution through the macromolecularization of nitroxides (ie, large molecules carry nitroxides). Macromolecular effects not only improve the stability of nitroxides by limiting their exposure to reductive substances in the body, but also improve the overall 1H water relaxation by increasing the concentration of nitroxides and slowing the molecular rotation speed. Results: Branched pDHPMA-mPEG-Ppa-PROXYL with high molecular weight (MW=160 kDa) and nitroxides content (0.059 mmol/g), it can form a nanoscale (~ 28 nm) self-assembled aggregate in a water environment and hydrophobic PROXYL can be protected by the hydrophilic outer layer to obtain the strong reduction resistance in vivo. Compared with the small molecular 3-Carboxy-PROXYL (3-CP), Branched pDHPMA-mPEG-Ppa-PROXYL displays there prominent performance: 1) its longitudinal relaxivity (0.50 mM-1 s-1) is about three times that of the 3-CP (0.17 mM-1 s-1); 2) the blood retention time of nitroxides is increased significantly from a few minutes of 3-CP to 6 h; 3) it could provide long-term and significant enhancement in MR imaging of the tumor, liver, kidney and cardiovascular system (heart and aortaventralis), and this is the first report on nitroxides-based MRI CAs for imaging the cardiovascular system. Conclusions: As a safe and efficient candidate metal-free magnetic resonance contrast agent, Branched pDHPMA-mPEG-Ppa-PROXYL is expected to be used not only in tumor, liver and kidney imaging, but also in cardiovascular system imaging, which expands the application scope of this kind of CAs.

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Amphiphilic branched polymer-nitroxides conjugate as a nanoscale agent for potential magnetic resonance imaging of multiple objects in vivo

Journal of Nanobiotechnology ◽

10.1186/s12951-021-00951-z ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Xiaoming Wang ◽

Shiwei Guo ◽

Zhiqian Li ◽

Qiang Luo ◽

Yan Dai ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Contrast Agents ◽

Cardiovascular System ◽

Water Environment ◽

Mri Contrast Agents ◽

The Body ◽

Resonance Imaging ◽

Cas A

Abstract Background In order to address the potential toxicity of metal-based magnetic resonance imaging (MRI) contrast agents (CAs), a concept of non-metallic MRI CAs has emerged. Currently, paramagnetic nitroxides (such as (2,2,5,5-tetramethylpyrrolidine-1-oxyl, PROXYL), (2,2,6,6-tetramethylpiperidine-1-oxide, TEMPO), etc.) are being extensively studied because their good stability and imaging mechanism are similar to metal-based contrast agents (such as Gd3+ chelate-based clinical CAs). However, a lower relaxivity and rapid in vivo metabolism of nitroxides remain to be addressed. Previous studies have demonstrated that the construction of macromolecular nitroxides contrast agents (mORCAs) is a promising solution through macromolecularization of nitroxides (i.e., use of large molecules to carry nitroxides). Macromolecular effects not only increase the stability of nitroxides by limiting their exposure to reductive substances in the body, but also improve the overall 1H water relaxation by increasing the concentration of nitroxides and slowing the molecular rotation speed. Results Branched pDHPMA-mPEG-Ppa-PROXYL with a high molecular weight (MW = 160 kDa) and a nitroxides content (0.059 mmol/g) can form a nanoscale (~ 28 nm) self-assembled aggregate in a water environment and hydrophobic PROXYL can be protected by a hydrophilic outer layer to obtain strong reduction resistance in vivo. Compared with a small molecular CA (3-Carboxy-PROXYL (3-CP)), Branched pDHPMA-mPEG-Ppa-PROXYL displays three prominent features: (1) its longitudinal relaxivity (0.50 mM− 1 s− 1) is about three times that of 3-CP (0.17 mM− 1 s− 1); (2) the blood retention time of nitroxides is significantly increased from a few minutes of 3-CP to 6 h; (3) it provides long-term and significant enhancement in MR imaging of the tumor, liver, kidney and cardiovascular system (heart and aortaventralis), and this is the first report on nitroxides-based MRI CAs for imaging the cardiovascular system. Conclusions As a safe and efficient candidate metal-free magnetic resonance contrast agent, Branched pDHPMA-mPEG-Ppa-PROXYL is expected to be used not only in imaging the tumor, liver and kidney, but also the cardiovascular system, which expands the application scope of these CAs. Graphical abstract

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Supramolecular Enhancement of Aminoxyl ORCA Contrast Agents

10.26434/chemrxiv.9640862.v1 ◽

2019 ◽

Author(s):

Hamilton Lee ◽

Jenica Lumata ◽

Michael A. Luzuriaga ◽

Candace Benjamin ◽

Olivia Brohlin ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Side Effects ◽

Magnetic Resonance ◽

Tobacco Mosaic Virus ◽

Contrast Agents ◽

Single Molecule ◽

Organic Radical ◽

Resonance Imaging ◽

Physiological Conditions

<div><div><div><p>Many contrast agents for magnetic resonance imaging are based on gadolinium, however side effects limit their use in some patients. Organic radical contrast agents (ORCAs) are potential alternatives, but are reduced rapidly in physiological conditions and have low relaxivities as single molecule contrast agents. Herein, we use a supramolecular strategy where cucurbit[8]uril binds with nanomolar affinities to ORCAs and protects them against biological reductants to create a stable radical in vivo. We further over came the weak contrast by conjugating this complex on the surface of a self-assembled biomacromolecule derived from the tobacco mosaic virus.</p></div></div></div>

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Magnetic resonance thermometry using a GdIII-based contrast agent

Chemical Communications ◽

10.1039/d0cc06400a ◽

2021 ◽

Vol 57 (14) ◽

pp. 1770-1773

Author(s):

S. A. Amali S. Subasinghe ◽

Jonathan Romero ◽

Cassandra L. Ward ◽

Matthew D. Bailey ◽

Donna R. Zehner ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Contrast Agent ◽

Contrast Agents ◽

Resonance Imaging ◽

Magnetic Resonance Thermometry

The complexes described here serve as contrast agents for magnetic resonance imaging thermometry.

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

Journal of Materials Chemistry B ◽

10.1039/d1tb01147b ◽

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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PO-1735: Superparamagnetic nickel ferrite nanoparticles as contrast agents in Magnetic Resonance Imaging

Radiotherapy and Oncology ◽

10.1016/s0167-8140(21)01753-9 ◽

2020 ◽

Vol 152 ◽

pp. S962

Author(s):

C. Ferrer ◽

C. Huertas ◽

R. Plaza ◽

E. Corredoira

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Contrast Agents ◽

Nickel Ferrite ◽

Ferrite Nanoparticles ◽

Resonance Imaging ◽

Nickel Ferrite Nanoparticles

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Manganese Ferrite Nanoparticles Encapsulated into Vitamin E/Sphingomyelin Nanoemulsions as Contrast Agents for High‐Sensitive Magnetic Resonance Imaging

Advanced Healthcare Materials ◽

10.1002/adhm.202101019 ◽

2021 ◽

pp. 2101019

Author(s):

Sandra Díez‐Villares ◽

Miguel A. Ramos‐Docampo ◽

Andrés da Silva‐Candal ◽

Pablo Hervella ◽

Abi J. Vázquez‐Ríos ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Vitamin E ◽

Magnetic Resonance ◽

Contrast Agents ◽

Ferrite Nanoparticles ◽

Manganese Ferrite ◽

Resonance Imaging

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Polyphosphorhydrazone-Based Radical Dendrimers

Molecules ◽

10.3390/molecules26051230 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1230

Author(s):

Vega Lloveras ◽

José Vidal-Gancedo

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Contrast Agents ◽

Biomedical Applications ◽

Organic Radicals ◽

Resonance Imaging ◽

Metal Free ◽

Antioxidant Agents ◽

New Type ◽

Paramagnetic Properties

The search for new biomedical applications of dendrimers has promoted the synthesis of new radical-based molecules. Specifically, obtaining radical dendrimers has opened the door to their use in various fields such as magnetic resonance imaging, as anti-tumor or antioxidant agents, or the possibility of developing new types of devices based on the paramagnetic properties of organic radicals. Herein, we present a mini review of radical dendrimers based on polyphosphorhydrazone, a new type of macromolecule with which, thanks to their versatility, new metal-free contrast agents are being obtained, among other possible applications.

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