Clinical decision making regarding the use of imaging is appropriately centered on diagnostic efficacy and individual patient factors. However, health policy and imaging guidelines may incorporate other inputs, such as cost-effectiveness and patient preference. In the context of climate change and resource scarcity, the environmental impacts of imaging modalities including ultrasound, CT, and MRI will also become relevant. The purpose of this study was to estimate the environmental impacts of various abdominal imaging examinations.
Using commercially available software (SimaPro) and data from user manuals and field experts, a streamlined life cycle assessment was performed to estimate multifactorial environmental impacts of the production and use of ultrasound, CT, and MRI per abdominal imaging examination.
Ultrasound consumed less energy in both production and use phases (7.8 and 10.3 MJ/examination, respectively) than CT (58.9 and 41.1 MJ/examination) or MRI (93.2 and 216 MJ/examination). Ultrasound emitted fewer CO2 equivalents in production and use phases (0.5 and 0.65 kg/examination) than CT (4.0 and 2.61 kg/examination) or MRI (6.0 and 13.72 kg/examination). Potential human health effects from pollutant emissions were found to be smallest with ultrasound in both production and use phases.
Among the three imaging modalities, ultrasound was found to have the least environmental impact, by one or more orders of magnitude in various domains. This analysis provides an initial framework for comparing environmental impacts across imaging modalities, which may provide useful inputs for cost-effectiveness analyses and policymaking.