UBCNews - Business - MRI Contrast Reaction Protocols: What Imaging Centers Need To Document

Episode Date: February 24, 2026

Have you ever wondered what actually happens when someone has a reaction to contrast media during an MRI or CT scan? It's way more common than you might think, and how we document and manage these reactions has just gotten a major overhaul. Today, we're examining the new protocol guide for MRI contrast reactions with our guest, an expert in radiology safety. ContrastConnect City: Las Vegas Address: Las vegas Website: https://www.contrast-connect.com/

Have you ever wondered what actually happens when someone has a reaction to contrast media during an MRI or CT scan? It's way more common than you might think, and how we document and manage these reactions has just gotten a major overhaul. Today, we're examining the new protocol guide for MRI contrast reactions with our guest, an expert in radiology safety. Thanks for having me. Yeah, this is a really timely topic. Most acute severe adverse reactions to iodineated contrast media occur within 30 minutes of injection, so patient monitoring during that window is critical. The challenge is that not all reactions are the same. Some are mild and self-limiting, while others could be life-threatening.

Right, and that's where documentation becomes so important. I mean, if a patient has a reaction, what exactly should medical staff be recording? Documentation of ID-nated contrast media hypersensitivity reactions, including symptoms and the specific inciting agent in the electronic health record is strongly recommended. It's not enough to just write contrast allergy. You need to document the exact contrast agent, the symptoms like urticaria, bronchospasm, or hypotension, and the severity. This optimizes future management, because if the patient needs contrast again, you know exactly what to avoid. or how to prepare. So specificity matters here. Um, what about the idea that someone with a shellfish allergy can't have contrast? I've heard that myth floating around. That's exactly what it is,

a myth. There's no clear association between shellfish allergy and an increased risk of contrast media hypersensitivity. Same goes for iodine allergy. Iodine is an essential element, not an allergy. The mechanism for immediate contrast reactions is related to the physiochemical properties of the media, not iodine content. So patients labeled as having iodine allergy are not candidates for premedication based on that alone. I see. That clears things up. So if someone does have a prior reaction, what's the protocol now? Do we automatically premedicate them with steroids? That's actually one of the big changes. For patients with a history of mild

immediate hypersensitivity reactions, pre-medication is not recommended anymore. The evidence just doesn't support it. Instead, switching the contrast agent is recommended when feasible, meaning if you know which agent caused the reaction and you have an alternative available. I remember early in my career, we premedicate almost everyone with a history of any reaction. It felt safer, but we've learned that switching agents is actually more effective. Interesting. And what about more severe reactions like anaphylaxis? For severe immediate reactions, the first step is to consider alternative imaging studies altogether, maybe contrast enhanced MRI, ultrasound, or even non-contrast core.

If there's no acceptable alternative, then switching the contrast agent is recommended when feasible, and premedication may be considered. But here's the key. The study should be performed in a hospital setting with a rapid response team available, including personnel, equipment, and supplies to treat anaphylaxis. That point about rapid response teams sets up our next piece, treatment protocols. But first, a quick word from our sponsor. This episode is brought to you by Contrast Connect.

Owned and led by radiologists, Contrast Connect provides regulatory-compliant virtual contrast supervision services that adhere strictly to CMS, ACR, and HIPAA guidelines. Their approach ensures patient safety while streamlining operational costs for imaging centers. If your facility needs remote oversight for contrast administration, visit the link in the description. Picking up on those rapid response teams, when someone is having a severe reaction, like anaphylaxis, right there in the imaging suite, what's the immediate treatment? Epinephrine is recommended as the first-line treatment for anaphylaxis. You stop the contrast infusion immediately and administer epinephrine intramuscularly, typically into the vastest lateralus in the thymestinephalus in the thymophagus. For adults, the dose is typically 0.3 to 0.5 milligrams, which may need to be repeated.

For children, it's 0.01 milligrams per kilogram. And this is critical. Delay in administering epinephrine has been associated with worse outcomes and increased risk of biphasic reactions, where symptoms resolve but then recur up to 72 hours later. So, timing is everything. I've also heard antihistamines mentioned. Are those part of the protocol? H1 antihistamines should not be administered as the primary and only treatment for anaphylaxis. They can address cutaneous symptoms like hives, but they don't treat the life-threatening respiratory or cardiovascular symptoms.

Epinephrine does. There's also no strong evidence that H2 antihistamines or glucocorticoids prevent bifasic anaphylaxis, despite common practice. You could say antihistamines are like bringing a band aid to a broken bone. They might help a little, but they're not fixing the real problem. Good analogy. Now, let's talk about delayed reactions. Some patients develop symptoms hours or even days later. How do we handle those? Delayed hypersensitivity reactions are less common than immediate ones, but they do occur. Usually cutaneous symptoms like maculipapular rash. For patients with a history of non-severe delayed reactions, there's no evidence to support premedication. The decision to use contrast and whether to switch agents should be made by the patient.

patient and treating physician, depending on the need for the study. For severe cutaneous adverse reactions, like Stevens Johnson syndrome, patients should strictly avoid contrast in the future. That makes sense. So, to everyone listening, if you've had a delayed rash after a CT scan, don't panic, but definitely let your doctor know. Now, what about follow-up? Should patients see a specialist after a severe reaction? Yes, after a severe immediate reaction. It's recommended that the radiologists consider referral to a specialized allergist. Skin testing may be helpful for higher risk patients with a history of severe reactions, particularly if performed within six months of the reaction. This can help identify alternative contrast agents that might be tolerated. A serum triptase level,

if drawn ideally within two hours, but up to six hours after symptom onset, can support the diagnosis of anaphylaxis. Wow, I didn't realize there was a blood test that could confirm anaphylaxis. That's definitely a tool clinicians should know about. Absolutely. And just to circle back, rooms where contrast material is administered should be equipped with basic and advanced life support monitoring equipment and drugs, as recommended by American College of Radiology Guidelines.

Radiologists and support staff are advised to regularly review treatment protocols, ideally annually, to stay current. In other words, preparation and protocol review are essential for patient safety. Right. One last thing. Pre-medication. We talked about it not being recommended for mild reactions, but what's the rationale there? The risk-benefit analysis has shifted. Direct risks of corticosteroid pre-medication are generally minor, like transient hyperglycemia or sleeplessness. But in direct risks include diagnostic delay because of the time required to complete the pre-medication regimen. When you weigh that against the very low rate of severe reactions with low osmolality contrast media, the benefit just doesn't outweigh the burden for mild prior reactors.

Switching agents, when possible, is more effective. Exactly. So the takeaway is, document everything, know your protocols, and don't rely on outdated myths. Thanks so much for breaking this down. My pleasure. Robust protocols and sound practice saves lives.