News | Contrast Media | March 12, 2021
The new contrast agent offers a vast improvement over traditional gadolinium-based products
(a) High-resolution 3D MRI brain vascular map using SAIO. Various blood vessels in the rat brain can be visualized. In addition to clinically important brain vessels including anterior cerebral artery, middle cerebral artery, posterior cerebral artery, fine vessel structures as thin as ~ 100 microns in diameter can be clearly visualized. (b) 3D MRI brain vascular map using Dotarem (gadolinium-based contrast agent). Resolution is low and microvessels are not visible. (c) For 3D reconstruction, multiple slice

(a) High-resolution 3D MRI brain vascular map using SAIO. Various blood vessels in the rat brain can be visualized. In addition to clinically important brain vessels including anterior cerebral artery, middle cerebral artery, posterior cerebral artery, fine vessel structures as thin as ~ 100 microns in diameter can be clearly visualized. (b) 3D MRI brain vascular map using Dotarem (gadolinium-based contrast agent). Resolution is low and microvessels are not visible. (c) For 3D reconstruction, multiple slices of MRI images of the rat heart were obtained after injection of SAIO. Rat coronary arteries (180 microns) which are 10 times thinner than human coronary arteries were successfully visualized. Coronary arteries supply blood to the heart muscle and the blockage or narrowing of such arteries causes myocardial infarction or angina, but visualizing these arteries was impossible due to the limited resolution of current MRI contrast agents. Image courtesy of Institute for Basic Science


March 12, 2021 — Heart attack and stroke are the first and second leading causes of death in developed countries, respectively. As the disease often results in sudden death with few special prognostic symptoms, early diagnosis is very important. For this purpose, imaging techniques such as magnetic resonance imaging (MRI) are widely used to identify the narrowing or blockage of blood vessels.

In MRI, contrast agents improve the visibility of the structures such as smaller blood vessels within the body. Just as satellites or global positioning systems (GPS) give traffic congestion information, the MRI contrast agents can give accurate information of vascular conditions such as vascular blockage and stenosis. Commonly used products are the gadolinium-based contrast agents. Free gadolinium ions have high toxicity, and thus they must be administered in chelated forms. However, even then there are some health risks of nephrogenic systemic fibrosis for patients with poor kidney functions. There have been some attempts to use paramagnetic iron-based nanoparticles as contrasting agents, but their renal clearance profile must be improved to prevent undesirable accumulation in the liver and other organs.

A collaborative research team led by Professor CHEON Jinwoo, the director of the Center for Nanomedicine (CNM), Institute for Basic Science (IBS) at Yonsei University, Seoul, South Korea and Professor CHOI Byoung Wook from Yonsei University College of Medicine developed a high-performance MRI contrast agent for 3D vascular mapping. The researchers developed a nanoparticle-based MRI contrast agent, called SAIO (Supramolecular Amorphous-like Iron Oxide). The particle is 5 nanometers in size, which is about 1,500 times smaller than the microvascular diameter. This allows it to circulate across blood vessels in the body.

The SAIO is a special nanoparticle that consist of a polysaccharide core made primarily with dextran cross-linked with other molecules. This core is then coated with an iron oxide surface to give it paramagnetic properties at room temperature. The hybrid nature of the SAIOs gives them both excellent biocompatibility and imaging performance. The researchers compared the contrast performance, retention, and renal clearance profile of the SAIO against Dotarem (a gadolinium-based agent) and iron oxide nanoparticles.

SAIO is one of the highest resolution imaging agents, which is 10 times more precise than the image generated using current contrast agents. It has achieved a 3D brain vascular mapping that can clearly identify brain microvessels as thin as a hair (100 microns) in animal experiments. In addition, to excellent resolution, the enhancement lasts substantially longer (>10 min) in comparison to Dotarem (< 2 min), which gives the radiologist an ample amount of time to carry out the imaging procedures. These excellent properties of the SAIO allowed the researchers to observe the heart blood vessels, which are hardly visible with current MRI contrast agents.

In addition to having high resolution, excretion of the contrasting agent through urine is especially important to avoid its accumulation within the body, which can cause various side effects. SAIO has an excellent renal clearance profile without accumulation in liver or spleen. It was also found that SAIO was stable without aggregation nor iron leaching for up to a year.

Director Cheon said, "SAIO is a next-generation contrast agent that satisfies both high resolution and safety at the same time" and professor Choi said, "SAIO is expected to play a vital role in increasing the accuracy of the diagnosis of cerebro-cardiovascular diseases such as stroke, myocardial infarction, angina, and dementia."

For more information: www.ibs.re.kr/en

Related MRI Content:

Novel MRI Contrast Agent Sidesteps Toxic Effects of Current Products

Cardiac MRI Contrast Agents Carry Low Risk of Adverse Events

Related Content on Gadolinium Contrast Safety:

The Debate Over Gadolinium MRI Contrast Toxicity

VIDEO: Big Concerns Remain for MRI Gadolinium Contrast Safety — An interview with Emanuel Kanal, M.D.

FDA Approves Bayer's Gadavist Contrast for Cardiac MRI in Adult Coronary Artery Disease Patients

VIDEO: Artificial Intelligence May Help Reduce Gadolinium Dose in MRI

Subtle Medical Receives FDA 510(k) Clearance for AI-powered SubtleMR

VIDEO: Managing Gadolinium Safety — Interview with Lawrence Tanenbaum, M.D.

Artificial Intelligence Processes Provide Solutions to Gadolinium Retention Concerns

MRI's Environmental Impact

VIDEO: How Serious is MRI Gadolinium Retention in the Brain and Body? An interview with Max Wintermark, M.D.

Radiology Has Failed to Properly Assess or Track MRI Gadolinium Contrast Safety

Recent Developments in Contrast Media

FDA Committee Votes to Expand Warning Labels on Gadolinium-Based Contrast Agents

European Medicines Agency Issues Update on Gadolinium Contrast Agents

ISMRM Issues Guidelines for MRI Gadolinium Contrast Agents

FDA: No Harm in MRI Gadolinium Retention in the Brain

VIDEO: MRI Gadolinium Contrast Retention in the Brain

Gadolinium May Remain in Brain After Contrast MRI

Related Content

Feature | Radiology Business | By Melinda Taschetta-Millane

Did you know that Imaging Technology News (ITN) maintains more than 40 comparison charts of product specifications from ...

Time August 12, 2022
arrow
News | Radiology Education

August 11, 2022 — After a three-year break, this spring featured the return of the anticipated Canon Roadshow Events ...

Time August 11, 2022
arrow
News | Computed Tomography (CT)

August 11, 2022 — For the first time, researchers successfully captured CT images of an entire woolly mammoth tusk ...

Time August 11, 2022
arrow
News | Radiology Imaging

August 11, 2022 — Bracco Imaging S.p.A. has announced the renewal of the “Bracco Fellowships” initiative, in partnership ...

Time August 11, 2022
arrow
News | Ultrasound Imaging

August 10, 2022 — Butterfly Network, Inc., a digital health company transforming care with handheld, whole-body ...

Time August 10, 2022
arrow
News | Point-of-Care Ultrasound (POCUS)

August 10, 2022 — Mindray North America, a global leader and developer of healthcare technologies and solutions for ...

Time August 10, 2022
arrow
Feature | Magnetic Resonance Imaging (MRI) | Christine Book

August 10, 2022 — The imaging community has lost a legend, recognized for having revolutionized the field of diagnostic ...

Time August 10, 2022
arrow
News | Prostate Cancer

August 9, 2022 — Bot Image, an Omaha-based MRI medical device company has developed an AI-driven medical device CAD ...

Time August 09, 2022
arrow
News | X-Ray

August 5, 2022 — GE Healthcare released its most advanced fixed X-ray system yet, the next-generation Definium 656 HD ...

Time August 05, 2022
arrow
News | Contrast Media

August 3, 2022 — According to an open-access article in ARRS’ American Journal of Roentgenology (AJR), electronic health ...

Time August 03, 2022
arrow
Subscribe Now