New Brain Scan Contrast Agent: Elucirem

Author: Ruoxi Lin

Editors: Eric Lin and Hwi-On Lee

Artist: Lalita Ma

It’s September 25, 2022. An adult patient steps into the Hospital of the University of Pennsylvania for her MRI scan appointment. The standard procedure is as follows: She will change into a hospital gown and lay flat on the patient's table before she is moved into the machine. While this is true for most patients, it may differ in other cases. Let’s say that our female patient is suspected of having a brain tumor; this time, before being put under the magnets of the MRI machine, she will be given an injection first. Her technologist puts an IV (intravenous injection) in her arm to administer a safe substance that will help clarify the brain images and locate the tumor. This substance, Elucirem — also known as Gadopiclenol — is the newest contrast agent on the market.

Developed by Guerbet, a pharmaceutical company specializing in drugs related to medical imaging, Elucirem received the FDA seal of approval on September 21st, 2022, with the first record of its use located in the same hospital that our female patient entered. Like most safe contrast agents, it is approved for use on most patients and has a low chance of adverse reactions, amounting to only around 0.2%. But it’s important to understand how contrast agents work from the get-go to determine whether this new drug improves from the old ones.

Contrast agents are substances that act as a “dye” for the human body’s internal structures, amplifying the contrast and, therefore, visibility of diseases in the body against organs and blood vessels. Most contrast agents are made with gadolinium, a rare earth metal normally toxic to humans but relatively harmless when used in Gadolinium Contrast Agents (GCBAs). This is because the metal in GCBAs undergoes a process known as chelation; chemical ions naturally produced in the body bind to toxic substances and prevent them from harming the body. The gadolinium administered through an IV is then excreted in the form of urine by the kidneys.

The images produced on the computer result from the MRI machine's magnetic imaging and a GCBA working in tandem. Gadolinium ions have the greatest possible number of unpaired electrons, which makes them more reactive. They can shorten the spin-lattice relaxation time, a type of MRI pulse sequence, or the magnetic gradient the machine operates with. Think of it as a set of lines of code that the machine runs through for the most conclusive picture. The relaxation of protons combined with reactive gadolinium ions creates brighter pictures that can aid radiologists in identifying lesions (damaged or diseased areas) in the body.

Elucirem is a particularly special kind of GCBA because it utilizes half the normal gadolinium dosage and has a high relaxivity that produces high-quality images. The secret lies in its structure; most gadolinium molecules in GCBAs have one molecular exchange site with water, while Elucirem has two. The additional site provides higher relaxivity, contrast, and more reactions with a lower gadolinium dose. This lowers the amount of gadolinium patients are exposed to, preventing possible systemic fibrosis and internal organ damage caused by prolonged usage. Not only that, but the usage of Elucirem can help reduce the amount of gadolinium emitted into the atmosphere, reducing our environmental footprint and preventing pollution.

As is with all substances, Elucirem still has an intended audience, so it may not work the best for everyone. For instance, patients with acute kidney injury or chronic kidney disease are highly advised not to take GCBAs because they can increase their risk of contracting nephrogenic systemic fibrosis, a rare disease that can cause darkened and tightened skin, as well as reduced internal organ function. Those with impaired kidneys can’t eliminate the gadolinium normally, so the function of the kidney may be worsened by injecting the metal.

Elucirem is an extremely significant creation in the field of radiology and may someday lead to further steps in the development of medicine-related technologies. It can reduce the chance of disease for patients needing specialized medical imaging and lower the environmental risks associated with gadolinium. Such advancements are just what our patients need in order to ensure their health and well-being.

Citations:

“Celebrating the First Clinical Administration of EluciremTM (Gadopiclenol) Injection for

MRI.” Appliedradiology.com, 20 Nov. 2023, appliedradiology.com/Articles/celebrating-

the-first-clinical-administration-of-elucirem-gadopiclenol-injection-for-mr. Accessed 25

Nov. 2023.

“EluciremTM (Gadopiclenol) Injection.” Guerbet North America, 2023,

www.guerbet.com/en-us/products-solutions/contrast-agents/elucirem-gadopiclenol-

injection. Accessed 25 Nov. 2023.

“ELUCIREMTM (Gadopiclenol) Is Now FDA Approved.” ELUCIREMTM (Gadopiclenol) Is

Now FDA Approved, www.elucirem.com/elucirem. Accessed 25 Nov. 2023.

Ferris, Nick, and Stacy Goergen . “Gadolinium Contrast Medium (MRI Contrast

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