RSNA2023 Leading Through Change
Daily Bulletin

Practical Power-Down Strategies Deliver Cost Savings

Monday, Nov. 27, 2023

By Lynn Antonopoulos

Optimized use of the low-power mode on CT scanners during non-operational hours may deliver substantial energy and greenhouse gas savings, according to findings presented in a Sunday session. Equipment power-down strategies may even offer benefits that reach beyond environmental concerns.



"Reducing health care related emissions and environmental impacts has co-benefits to multiple stakeholders," said Maura J. Brown, MD, MHA, FRCPC, clinical assistant professor of radiology at the University of British Columbia (BC) in Vancouver, Canada. "As I read about the health impacts of the climate crisis and how providing health care is part of the problem, accounting for 4%-10% of global carbon emissions, I considered it might be within my sphere of influence as a radiologist to become part of the solution in reducing our health care emissions."

Dr. Brown and a team that included colleagues from medical physics and facilities management, radiologists, technologists and a business analyst, set out to assess and model potential energy and cost savings, within the parameters of their existing equipment, without adding to technologist workload or interfering with department and patient workflow.

The researchers extracted CT scanner usage data from the radiology information systems of four health care organizations and developed models for energy savings. They began with 37 scanners but excluded 20 that were identified as having either a lack of a practical low-power mode or a lack of sufficient data from the manufacturer.

Dr. Brown and colleagues classified the remaining 17 scanners based on clinical usage patterns—seven light-use, five medium-use and five heavy-use. They developed a formula to calculate the energy saved based on the difference in power consumption modes, the number of scans and the estimated time the scanner was active during a specified period.

The team identified a potential annual energy savings of 251,024 kWh if all light- and medium-use scanners were switched to low power mode when not in use. "This is the equivalent of 456,042 miles driven in a gasoline-powered car and approximately U.S. $30,876 saved in electricity costs," Dr. Brown said.

She noted that because of their usage volume, it was impractical to power down heavy-use scanners.

Collaborative Efforts Provide Morale Boost

"I was really surprised at the amount of energy and money that can be saved by setting scanners to low power modes in non-operation hours," Dr. Brown said. "For just one scanner, the numbers are interesting, however when many sites are involved, the scale of energy and cost saving is astounding for such a simple intervention."

In addition to delivering measurable savings, Dr. Brown said the effort may provide other, intangible benefits including a morale boost obtained by radiologists and department staff when working on solutions for reducing emissions and improving health locally and globally.

"It's an opportunity for radiologists to be leaders and important for us to become engaged, to look around, talk to people outside of our normal day-to-day work and encourage cross collaboration," Dr. Brown said. "In more general terms of reducing health care waste and carbon emissions, individuals may feel that it doesn't matter what one person does. In one way, this is true; however, when you get many people, practices and facilities implementing low carbon, low waste, sustainable health care, the cumulative positive effects are enormous."

Access the presentation, "Energy and Greenhouse Gas Emission Savings from Power Down of CT Scanners in Non-Operational Hours in a Large Regional Practice," (S2-STCE1-2) on demand at