VUMC Radiology and Philips Publish Collaborative Life Cycle Assessment in 'Radiology'

The analysis found diagnostic services generate the equivalent of nearly 1,100 gas-powered cars annually, or an estimated 4.6kt carbon dioxide equivalent.

The life cycle assessment conducted by the Department of Radiology and Philips uncovered where the cumulative greenhouse gas emissions come from 

and identified top hot spots that can be targeted through efficiency strategies. (iStock/Diana Duren)

A seminal cradle-to-grave analysis of hospital-based radiology services by the Department of Radiology at Vanderbilt University Medical Center and Royal Philips found the energy consumption from imaging equipment accounted for more than 50% of the department’s greenhouse gas emissions and shed light on areas to focus future evidence-based strategies to decarbonize.

The life cycle assessment (LCA) results, which have been peer-reviewed and published in Radiology, found diagnostic services generate the equivalent of nearly 1,100 gas-powered cars annually, or an estimated 4.6kt carbon dioxide equivalent.

Researchers looked at life cycle data (including material extraction, manufacturing, transportation and service life for products used to provide radiology services) from a 10-year period across a large radiology practice, including diagnostic radiology services used for inpatient, outpatient and emergency department visits within an adult hospital. Data did not include nuclear medicine, interventional radiology or breast imaging services.

Radiology services support diagnostics across all specialties. Yet, previous specialty studies examined energy use of imaging equipment, monitors and other health care processes, but not the entire suite of services within a diagnostic radiology department nor its impact across the entire lifecycle – from material extraction to end of life. Climate change, driven primarily by human-induced greenhouse gas (GHG) emissions, poses major risks to human health. Health care contributes 8.5% of GHG emissions in the U.S.

Diana Carver, PhD                      John Scheel, MD, MPH

“Our study is a crucial stride in understanding the overall environmental impact of radiology. Identifying a range of contributors to radiology’s carbon footprint means we can develop focused strategies to reduce emissions without compromising patient care. Our goal is to enable high-quality health care that aligns with our collective responsibility to advance sustainability,” said Diana Carver, PhD, associate professor of Radiology and Radiological Sciences, and principal investigator of the study.

Carver, John Scheel, MD, PhD, professor of Radiology and vice chair of Global Health in the Department of Radiology and Radiological Sciences, and Reed A. Omary, MD, MS, professor of Radiology and Biomedical Engineering, along with Philips, collaborated with health care sustainability expert Cassandra Thiel, PhD, assistant professor in NYU Langone Health’s Departments of Population Health and Ophthalmology.

The diagnostic radiology services accounted for 4.6 kt carbon dioxide equivalent, with MR accounting for the majority of GHG emissions (48%), followed by CT (24%), X-ray and fluoroscopy (12%), general department workstation PACS and data storage (12%) and ultrasound (4%).

The LCA helped uncover where the cumulative GHG emissions come from and identified the following top hot spots:

• 54% from energy use of imaging equipment.
• 11% from the production of imaging equipment.
• 11% from the production and use of onsite and remote workstations and data storage.
• 10% from the production and use of linens.
• 8% from the production of disposable supplies.

“What stands out to me is the detail to which we can explore, and change, energy usage patterns. For example, a key finding is most of our carbon emissions with CT occurred when we were not imaging patients – during downtime. Now we can work with colleagues to reduce our per-patient waste by imaging more patients in a scheduling block. At the same time, we can collaborate with our industry partners to develop CT software and hardware upgrades to reduce energy use, thus carbon emissions, during downtime,” said Scheel.

The team was surprised at the emergence of both digital workstations and data storage as well as linens production and laundering as about 10% of emissions each, which underscores the opportunity for health systems and hospitals to look across their value chains for strategies to increase efficiency, said Scheel.

Landmark assessment powered by collaboration

Life cycle assessment methodology dates to the 1960s to study the environmental impact of products from mining or growing and harvesting raw materials to transporting, producing, installing, using and disposing of them. LCAs are used across industry sectors to establish baseline data on carbon emissions and environmental waste and analyze the impact of interventions on carbon footprints.

(courtesy of Ecoinvent)

Using this, the gold standard assessment methodology produces a more accurate sustainability picture. An energy calculation of a CT scanner may show how much energy is used during an imaging exam and between patient scans; but the LCA reveals the environmental impact associated with, for example, the production of the scanner, operation use and disposal upon expiration.

“We are thrilled to have conducted this landmark study together with Philips. Collaborations that join academia and industry are fundamental to recognizing that climate care is health care. Joint effort works at the speed and scale necessary to mitigate the impact of the changing environment on people’s health and for future generations,” said Omary.

“This collaboration illustrates the importance of joining forces to tackle significant challenges such as reducing radiology’s carbon footprint while also reducing the cost of care. We can do both. Further, we’ve identified critical areas for improvement, including optimizing equipment usage and enhancing patient flow which can also lead to better patient care while we also increase access to that care,” said Jeff DiLullo, Chief Region Leader, Philips North America. “This study underscores the importance of driving innovation in technology to deliver better, more sustainable care. We are also helping providers to adopt other best practices like circularity to extend accessibility of care for more people. Through increased options for upgrades and refurbishment, we help customers maximize the value of their existing systems and sustainably reduce waste, all while lowering the total cost of ownership.”

The life cycle inventory used SimaPro 9.3.0.227 (PRé Sustainability) and the EcoInvent v3.8 database,28 one of the most comprehensive LCI databases available. Electricity consumption comes from the case location from the Southeastern Electric Reliability Council (SERC) regional power grid.