Evaluating the environmental sustainability of AI in radiology: a systematic review of current practice

Objective Data-heavy and energy-heavy artificial intelligence (AI) technologies are increasingly being applied in healthcare, particularly for clinical imaging, often without consideration of their environmental impacts. We aimed to assess current practice in considering and evaluating environmental sustainability (ES) impacts of AI-enabled clinical pathways in radiology. Methods and analysis We searched MEDLINE and Embase on 5 November 2024 for quantitative clinical radiology studies which used a machine learning approach to aid in radiological diagnosis or intervention and discussed its ES impacts. We included peer-reviewed, English language studies published from 2015 onwards. Our primary outcome was any quantitative reporting of ES impacts, and our secondary outcome was any within-text qualitative discussion of ES impacts. For quantitative outcomes, we conducted synthesis without meta-analysis based on effect direction and size, with our secondary outcome synthesised narratively. Results Of 4449 records screened, 18 met our inclusion criteria. Six (33.33%) reported quantitative ES outcomes and 15 (83.33%) included qualitative discussion of ES. When applied to the same tasks, algorithms designed to be ‘lightweight’ demonstrated from 2.19 to 17.15 times reduction in carbon emissions (median 7.81, 16 datapoints) and from 1.60 to 751.62 times reduction in energy consumption (median 3.22, 16 datapoints) compared with state-of-the-art alternatives, while maintaining similar or improved clinical performance. No quantitative studies compared ES outcomes for an AI-enabled pathway versus standard-of-care, and 75.00% of studies reporting only on our secondary outcome included just a single sentence on sustainability. Conclusion Despite increasing concern about the climate impacts of AI, environmental outcomes are rarely considered within evaluations of AI technologies in clinical radiology. However, there are approaches available with smaller carbon footprints. To meet their stated aims on sustainability, funders and governance bodies should consider how to promote integration of environmental impact assessment into AI health research and evaluation. PROSPERO registration number CRD42024601818.