Sustainability of contrast-enhanced breast imaging: a review of current evidence

Breast cancer is the most commonly diagnosed malignancy among women worldwide. Contrast-enhanced imaging is central to diagnosis, staging, and treatment monitoring, yet its increasing use raises important environmental concerns. This review critically compares the sustainability of contrast-enhanced mammography (CEM) and breast magnetic resonance imaging (bMRI), focusing on contrast medium ecotoxicity, energy consumption, data storage, digital infrastructure, patient access, and travel-related emissions. Both iodinated and gadolinium-based contrast media persist in aquatic environments and contribute to water pollution. Although standard wastewater treatment removes a higher proportion of iodinated contrast, the injected dose is substantially larger, resulting in a greater overall environmental load. Gadolinium-based media are used in smaller quantities but are poorly removed by conventional treatment processes and may release toxic free gadolinium ions after excretion. While CEM involves ionizing radiation and a smaller field of view, it consumes markedly less energy per examination, generates smaller data volumes, and can be integrated into existing mammography infrastructure-enhancing accessibility, enabling decentralized deployment, and reducing patient travel. CEM is also faster, more cost-effective, and often preferred by patients due to greater comfort and shorter examination time. In contrast, bMRI, though radiation-free and offering wider anatomical coverage, has a significantly higher energy demand and digital footprint. Overall, CEM demonstrates advantages in environmental, economic, and social sustainability without compromising diagnostic performance in selected clinical indications. Radiology departments can meaningfully reduce healthcare's carbon footprint by incorporating sustainability principles into modality selection, contrast-media management, and workflow optimization. CRITICAL RELEVANCE STATEMENT: CEM and bMRI address similar clinical indications with comparable diagnostic accuracy. CEM offers potential sustainability advantages through lower energy use, smaller data volumes, and easier integration into existing infrastructure, although it involves ionizing radiation, a limited field of view, and a higher environmental load from iodinated contrast. Considering sustainability alongside clinical factors can help radiology departments reduce environmental impact while maintaining high diagnostic standards. KEY POINTS: Sustainability should be an integral factor when selecting imaging modalities for breast cancer care. Both iodinated and gadolinium-based contrast media show environmental persistence and ecotoxic potential, with iodinated contrast producing a higher total environmental load despite greater removal in wastewater treatment. CEM consumes markedly less energy per examination and produces smaller data volumes than bMRI, reducing its digital and carbon footprint. CEM can be implemented on existing mammography systems, reducing patient travel, exam time, and costs.