Measuring the Environmental Impact of MRI and CT: A Life Cycle Assessment

Objective

To assess the environmental impact of MR and CT imaging using life cycle assessment, focusing on energy use, resource consumption, and emissions.

Methods

This International Organization for Standardization 14040-guided life cycle assessment-based study focused on MRI and CT services, including the production and use of three MRI and four CT scanners, at a quaternary care 800-bed academic medical center in the Southeastern United States over a 1-year period. Data were collected through direct observation, record review, staff interviews, and energy metering. Environmental impacts were assessed using SimaPro 9.3.0.2 and the Ecoinvent v3.8 database.

Results

MRI and CT services at this site generate an estimated 221 and 108 tons of carbon dioxide equivalent per year, respectively. This is equivalent to the emissions of 52 (MRI) and 25 (CT) cars driven annually. Energy consumption accounted for the largest portion of emissions (58% for MRI, 33% for CT), followed by disposable supplies (26% for MRI, 16% for CT), capital equipment production (7% for MRI, 13% for CT), and linens (4% for MRI, 11% for CT). Switching to solar photovoltaic electricity could reduce total MRI emissions by 70% and CT emissions by 40%, increasing the relative impacts of scanner production, disposable supplies, and linens.

Discussion

This study highlights the significant environmental impact of MRI and CT services, particularly energy consumption. Renewable energy sources, such as solar photovoltaics, offer the greatest potential for mitigating the environmental footprint. Additional strategies include optimizing scanner utilization, adopting reusable or reprocessable supplies, and embracing circular business practices such as circular manufacturing and extending the lifespan of capital equipment.