By Matt Skoufalos
Amidst the overwhelming scientific evidence that carbon emissions driven by human activity continue to contribute to global health challenges posed by climate change, the field of health care is itself taking long overdue steps to address its role in the mechanisms at work therein.
“Health Care’s Climate Footprint,” a 2019 environmental policy paper from the international non-governmental agency Health Care Without Harm, provides some of the most comprehensive accounting of the scope of carbon emissions attributable to the business of health care across the planet.
According to the paper, the healthcare industry accounts for 4.4 percent of global carbon emissions. About 10 percent of the carbon emissions produced by the United States alone is attributed to health care, and the American health care system is the top C02 emitter “in both absolute and per capita terms,” at 546 million tons.
That same policy paper describes greenhouse gas emissions from health care as resulting from “energy consumption, transport, and product manufacture, use, and disposal,” in various ways. Direct emissions from health care facilities and their vehicle fleets comprise 17 percent of their global health care carbon footprint; they contribute another 12 percent via indirect emissions from purchased energy sources (electricity, steam, cooling, and heating). Health Care Without Harm attributes the remaining 71 percent to supply chain sources “through the production, transport, and disposal of goods and services” including “pharmaceuticals and other chemicals, food and agricultural products, medical devices, hospital equipment, and instruments.”
Finally, even when accounting for supply-chain emissions, 25 percent of all health care emissions “are generated outside of the country where the health care product is ultimately consumed,” according to the document. It also attributes the bulk of emissions from the health care industry to its consumption of fossil fuels, and notes that half of the global climate footprint from health care sources is a result of energy generation for and within the health care sector.
The research paper “Climate Change, Carbon Dioxide Emissions, and Medical Imaging Contribution,” written by Eugenio Picano, Cristina Mangia, and Antonello D’Andrea, and published by the Journal of Clinical Medicine in 2022, posits that medical imaging accounts for approximately 1 percent of the global carbon health care footprint, based on “a conservative estimate of 10 billion medical examinations per year worldwide.”
Nearly every authoritative source on carbon emissions in general, as well as those relating to the health care industry in specific, agree that the work set before the largest institutions of the day lies in changing the courses of their environmental future in ways great and small. How that work might be achievable, and managing the changes that inherently will come with it, now falls to decision-makers in the device manufacturing world and leading health care institutions as much as it falls to legislators and policymakers.
Vibhas Deshpande, vice president of sustainability innovation and strategic research at Siemens Healthineers, said that his company has put its commitment to sustainability front and center among organizational objectives, foremost by adding the word “sustainably” to its value statement last year – “We pioneer breakthroughs in health care. For everyone. Everywhere. Sustainably.” – and establishing key performance indicators for charting the change.
These KPI include a 90 percent reduction in its Scope I emissions (volume of greenhouse gas emissions directly controlled by the company) and Scope II emissions (volume of greenhouse gas emissions indirectly controlled by the company, including purchased energy) by 2030, before ultimately hitting net zero by 2050. Siemens Healthineers is also seeking to reduce its Scope III emissions (all indirect emissions not covered by Scopes I and II) 28 percent by 2030, and 90 percent by 2050.
“We are absolutely committing to this,” Deshpande said. “We need to help our customers who are downstream, so both of us benefit from a reduction in the carbon footprint.”
Reducing emissions at the institutional level means reducing power consumption at the imaging device level. Siemens Healthineers research collaborations with the Universities of Basel in Switzerland and California at San Francisco (USCF) illustrated, respectively, how much electricity is required to power MR machines, and how much might be conserved by regulating it.
“In the University of Basel study, Dr. Elmar Merkle and colleagues showed that the annual consumption of three CT units and four MR scanners was equal to the annual energy consumption of a town of 850 people,” Deshpande said. “That’s the magnitude of the problem here.”
UCSF research revealed what could perhaps have been expected, which is that even merely turning the systems off when they’re not in use offers a significant reduction in power consumption.
“Most scanners are not in use overnight, but they’re still consuming energy because superconducting magnets need to be kept cool,” Deshpande said. “One way to reduce energy during non-operational hours is to cycle cooling. That saves a lot of energy; that’s an easy win to get.”
Similarly, Deshpande spoke about finding ways to manage energy demand from MR systems by using artificial intelligence (AI)-driven software optimization to help configure their operations. Newly available, AI-powered, low-magnetic-field-strength scanners also may help conserve resources.
“We will always need to strike a balance between the benefits of these high magnetic fields – such as higher resolution and higher signal, to better understand some clinical problems – and the resources needed to manufacture, install and run this equipment,” Deshpande said.
“Cost-effectiveness comes down to what is the appropriate use of resources for each patient,” he said. “Imaging as a standalone activity is energy-intensive, but if you look at the entire patient care pathway, the appropriate tests done at the right time can be valuable in reducing the entire cost of care in that patient’s life.”
For an original equipment manufacturer (OEM), contemplating that care pathway also motivates an internal analysis of the life cycle of an individual scanner, from materials sourcing to the manufacturing process, use of the technology in the field, and what happens when it’s retired.
Deshpande said Siemens Healthineers is trying to extend the useful life of its scanners through modular designs that are able to be upgraded at the customer site, and also by recycling those elements of its manufacture that are able to be recovered. The helium used in cooling MR magnets can be reclaimed from defunct scanners and reused in other processes. Newer Siemens Healthineers MR systems, like the MAGNETOM Free.Max, which is powered by a 0.55T magnet, use only a fraction of the helium demanded by legacy systems.
“It’s not only about when a machine is in use, but we really want to think holistically from the material supply to the end of life of the machine,” Deshpande said.
To that end, OEMs will be instrumental in the work that’s needed to build partnerships and policy guidance as the medical imaging space manages operational changes in pursuit of sustainability. Device manufacturers may be able to reduce the energy their imaging systems consume by helping their customers to manage infrastructure conditions onsite before they’re installed, Deshpande said, or by working with regulators to develop EnergyStar criteria for medical imaging devices. Customer and academic partnerships provide key feedback and information that helps the next generation of technology function better and more efficiently.
“It really has to be a collaboration,” Deshpande said. “You can derive intelligence and drive changes by integrating information from the manufacturers, clinicians, and companies providing different products being used in the care pathway. I think we all believe that this is the right thing to do.”
Dr. Sean Woolen, director of prostate imaging at UCSF, who worked with Siemens Healthineers on MRI power conservation research, believes the pathway to greater sustainability in operational culture must be “framed in a win-win scenario” to generate buy-in from all parties involved. For example, saving on electricity consumption doesn’t only reduce the carbon footprint of a health care entity, it also cuts costs, which is important when green energy sources are a more expensive choice than their fossil-fuel-based alternatives.
“Some people will talk about the ultimate solution, which is having your hospital on fully clean energy,” Woolen said. “At UCSF, we have quite a bit of our hospitals on clean energy. But usually, the cleaner the energy, the more expensive the price. Being able to be more efficient with energy use saves money.”
Changing behavior in any context is both a critical piece of embracing sustainability culture and “one of the hardest things to do,” Woolen said. The most lasting improvements might be those that are folded into protocols or the background operations of new technologies. For instance, the three key insights from the MRI study – powering down equipment, shortening scanning times, and scanning on lower field strengths – don’t achieve as much individually as realizing each improvement, let alone doing so at scale.
“We talk about performance gaps in health care all the time,” Woolen said. “You have some solutions that we know would make a huge impact on sustainable health care. How many institutions are following those practices so that we can close that gap?”
“Anything automated is going to be the easiest level of behavior change,” he said. “Figure out what the barriers are for technologists who don’t have the knowledge; why some of these simple solutions aren’t always happening. We should all be practicing at that same high level of evidence.”
Other imaging leaders believe some of the gains that can be won by managing power consumption on imaging devices can be further extended by similarly turning off PACS monitors and computers as well as office lights at the end of a shift.
A group out of Northwestern University is working with Siemens Healthineers to measure the power output associated with different pulse sequences during an imaging study, to see whether certain studies require more energy than others. The same researchers are also seeking ways to recycle some of the disposable materials consumed in the imaging space, like iodine contrast agents and their packaging materials.
Dr. Katherine Maturen is the associate chair for ambulatory radiology and strategy at Michigan Medicine, and medical director of its East and Northeast Radiology Ambulatory Care Units in Ann Arbor, Michigan. Maturen and Woolen are collaborating on a comprehensive scoping review of medical imaging sustainability literature, synthesizing previous studies to develop a database of known values (such as the energy and carbon emissions associated with a single scan), and create a roadmap for future research.
Among hundreds of articles that have been published on the subject of radiology sustainability, Maturen noted that maybe only 50 articles are based on primary data collection efforts; most articles are commentaries and calls for action.
“Right now, there’s a lot of gaps in our quantitative knowledge; once we’ve resolved that, we can start to make broader statements,” she said.
Maturen agrees that it’s difficult to reconcile the impulse towards reducing energy consumption in medical imaging with the historic drive in the field to capture “the most high-definition, beautiful images achievable.” It’s even more complicated to demonstrate a clear business directive in doing so, especially in a landscape of conflicting financial and cultural incentives.
“I think you have to make it practical to people,” Maturen said. “It has to be within the scope of what we can change. These issues are very high-level and seem out of reach to many practicing radiologists.”
“What other specialties are making headway on sustainability?” she said. “Anesthesia, because they’re literally using greenhouse gases. Some surgical specialties are doing well because they’re targeting waste, so they’re getting efficacy quickly.”
Maturen also rightly points out that the bottom line of the argument – reducing carbon emissions – takes precedence over the mechanisms by which people in the health care sector achieve it.
“The outcome we’re talking about is an ethical outcome,” she said. “It doesn’t matter why they make a sustainable change in practice – maybe because it is faster, less expensive or because they are personally concerned about the environment – it just matters that they do it. As sustainability becomes incorporated into practice, people’s attitudes will change over time.” •
