Ecodesign and Operational Strategies to Reduce the Carbon Footprint of MRI for Energy Cost Savings

Background: Radiology is a major contributor to health care's climate footprint due to energy-intensive devices, particularly MRI, which uses the most energy.Purpose: To determine the energy, cost, and carbon savings that could be achieved through different scanner power management strategies.Materials and Methods: In this retrospective evaluation, four outpatient MRI scanners from three vendors were individually equipped with power meters (1-Hz sampling rate). Power measurement logs were extracted for 39 days. Data were segmented into off, idle, prepared-to-scan, scan, or power-save modes for each scanner. Energy, cost (assuming a mean cost of $0.14 per kilowatt hour), and carbon savings were calculated for the lowest scanner activity modes. Data were summarized using descriptive statistics and 95% CIs. Results: Projected annual energy consumption per scanner ranged from 82.7 to 171.1 MW-hours, with 72%-91% defined as nonproductive. Power draws for each mode were measured as 6.4 kW & PLUSMN; 0.1 (SD; power-save mode), 7.3 kW & PLUSMN; 0.6 to 9.7 kW & PLUSMN; 0.2 (off), 9.5 kW & PLUSMN; 0.9 to 14.5 kW & PLUSMN; 0.5 (idle), 17.3 kW & PLUSMN; 0.5 to 25.6 kW & PLUSMN; 0.6 (prepared-to-scan mode), and 28.6 kW & PLUSMN; 8.6 to 48.3 kW & PLUSMN; 11.8 (scan mode). Switching MRI units from idle to off mode for 12 hours overnight reduced power consumption by 25%-33%, translating to a potential annual savings of 12.3-21.0 MW-hours, $1717-$2943, and 8.7-14.9 metric tons of carbon dioxide (CO2) equivalent (MTCO2eq). The power-save mode further reduced consumption by 22%-28% compared with off mode, potentially saving an additional 8.8-11.4 MW-hours, $1226-$1594, and 6.2-8.1 MTCO2eq per year for 12 hours overnight. Implementation of a power-save mode for 12 hours overnight in all outpatient MRI units in the United States could save U.S. health care 58 863.2-76 288.2 MW-hours, $8.2-$10.7 million, and 41 606.4-54 088.3 MTCO2eq. Conclusion: Powering down MRI units made radiology departments more energy efficient and showed substantial sustainability and cost benefits.& COPY; RSNA, 2023

Automated summary

This study evaluated the energy-saving, cost-saving, and carbon-reducing effects of different scanner power management strategies. The results showed that powering down MRI units could significantly reduce energy consumption, carbon emissions, and economic costs, with important implications for overall sustainability.