Impact of Unnecessary Imaging Scans on Climate Change

April 3, 2025

Recent research published in the Journal of the American College of Radiology highlights an alarming correlation between unnecessary medical imaging scans and climate change. This study reveals that such scans contribute significantly to greenhouse gas emissions, with Medicare recipients alone generating up to 129 metric kilotons of carbon dioxide annually. This emission level is comparable to the energy consumption of a town with a population exceeding 70,000.

Researchers from the Harvey L. Neiman Health Policy Institute conducted an extensive analysis of imaging data for approximately 30 million traditional Medicare beneficiaries from 2017 to 2021. They found that a substantial percentage--estimated at 26%--of imaging scans ordered for Medicare patients are deemed inappropriate. By tracking these unnecessary scans, the researchers were able to quantify their associated carbon dioxide emissions.

Different types of imaging scans contribute varying amounts of emissions. For instance, MRIs account for up to 136 kilotons of emissions, while CT scans contribute approximately 178 kilotons, X-rays add 46 kilotons, and ultrasounds contribute about 23 kilotons. Notably, these estimates also take into account the energy consumed when the machines are in standby mode or during production phases between scans.

By reducing the number of unnecessary imaging scans, researchers estimate that carbon emissions could be decreased by as much as 129 kilotons. Unnecessary CT scans are responsible for nearly half of these emissions, while unnecessary MRIs contribute around a quarter.

The study's authors caution that emissions from medical imaging are likely to rise further due to increasing overall imaging volumes in the past decade and the potential for additional increases linked to climate change-related events.

Reducing unnecessary imaging procedures not only has environmental benefits but also mitigates risks and costs for patients and the healthcare system. The findings underscore the need for healthcare professionals to critically assess the necessity of imaging orders to promote both patient well-being and environmental sustainability.

For more detailed information, refer to the study by Gregory Cavanagh et al., titled Excess Greenhouse Gas Emissions Associated With Inappropriate Medical Imaging in the US Medicare Part B Population From 2017 to 2021.