Picture this: Over the past 13 years, a staggering 13.5 billion milliliters of contrast media – that's enough to fill millions of swimming pools – has been used in medical imaging scans for millions of Americans. This revelation comes from a recent study and shines a light on an overlooked environmental crisis tied to our healthcare system. But here's where it gets controversial: Are we prioritizing patient health at the expense of our planet's well-being? Let's dive into the details and explore what this means for medicine, the environment, and perhaps even your next doctor's visit.
From 2011 to 2024, Medicare beneficiaries received 13.5 billion milliliters of contrast media during 169 million advanced imaging procedures, such as CT scans and MRIs. This eye-opening data was revealed in a research letter published on December 5 in JAMA Network Open. For beginners wondering what contrast media is, think of it as a special dye injected into the body to highlight areas of interest in scans, making it easier for doctors to diagnose conditions like tumors or blockages.
The research was led by Florence Doo, MD, from the University of Maryland in Baltimore, in partnership with experts from the Harvey L. Neiman Health Policy Institute, NYU Langone, and universities in the UK, including Oxford and Imperial College London. In a statement from the institute, Doo emphasized that while these agents are essential for accurate imaging, they linger in the environment long after use. 'Contrast agents are crucial for effective imaging, but they don't vanish post-procedure,' she explained. 'Elements like iodine and gadolinium come from finite resources and can seep into wastewater, building up in rivers, oceans, and even our tap water. By measuring which types of scans consume the most contrast, we can create smart, feasible plans for managing these substances responsibly – ensuring patients still get top-notch, safe care.'
And this is the part most people miss: These contrast agents aren't just helpful tools; they're also stubborn pollutants that standard water treatment plants struggle to eliminate fully. That raises real questions about their lasting effects on ecosystems and human health over time.
The team analyzed public claims data from U.S. Medicare Part B fee-for-service program, spanning 2011 to 2024. They used specific medical coding (CPT codes) to pinpoint contrast-involving imaging types, including CT, CT angiography, MRI, and MR angiography. To estimate volumes, they applied typical dosages: 100 milliliters for iodine-based agents and 15 milliliters for those using gadolinium.
Their analysis uncovered that Medicare patients had 169 million contrast-enhanced scans across 82 CPT codes. This broke down to 41 codes for iodine-based exams (making up 50% of the total), including 28 for CT scans (68%) and 13 for CT angiograms (32%). For gadolinium-based procedures (the other 50%), there were 29 MRI codes (71%) and 12 MR angiography codes (29%). All told, these required 13.5 billion milliliters of contrast media.
Yearly usage saw an upward trend, with average increases of 5.2% per year for iodine-based agents and 3.5% for gadolinium-based ones from 2014 to 2019. The COVID-19 pandemic caused dips in 2020, but volumes bounced back strongly in 2021 – up 10.8% for iodine and 10.1% for gadolinium – likely due to deferred procedures. Iodine-based agents dominated the overall volume, accounting for 12.9 billion milliliters (95.6%). The biggest single contributor? CT scans of the abdomen or pelvis, using 4.4 billion milliliters. On the gadolinium side, brain MRIs led the pack at 221 million milliliters.
But here's a potential counterpoint that might spark debate: Some argue that the environmental toll is exaggerated, pointing out that medical imaging saves countless lives and that pollution from imaging is just a drop in the ocean compared to other industries. What do you think – is this a fair trade-off, or should we demand greener alternatives sooner?
Doo's team stresses that practical steps exist to curb this pollution without sacrificing care. For instance, doctors can double-check if a scan is truly needed, adjust doses based on a patient's weight to avoid overuse, and switch to vials that allow multiple uses. Excitingly, new options like eco-friendly, biodegradable contrast agents and AI-powered tools to minimize doses are on the horizon – though they're still in testing and need thorough safety checks before widespread use.
Ultimately, these findings paint a concerning picture of imaging's global footprint. 'We can't turn a blind eye to the ecological fallout from medical scans,' Doo warned. 'Managing contrast agents wisely is a tangible way to balance patient needs with Earth's health, fitting into larger efforts for sustainable healthcare.'
For the full details, check out the report at https://www.doi.org/10.1001/jamanetworkopen.2025.47304.
Disclosure: Doo received funding from a National Institutes of Health grant and the Association of Academic Radiology Clinical Effectiveness in Radiology Research Academic Fund, partially supported by GE Healthcare.
What are your thoughts on this? Do the lifesaving benefits of advanced imaging justify the environmental risks, or should stricter regulations be implemented now? Agree, disagree, or have your own take? We'd love to hear from you in the comments – let's start a conversation!
