Environmental Sustainability and MRI: Challenges, Opportunities, and a Call for Action

Abstract

The environmental impact of magnetic resonance imaging (MRI) has recently come into focus. This includes its enormous demand for electricity compared to other imaging modalities and contamination of water bodies with anthropogenic gadolinium related to contrast administration. Given the pressing threat of climate change, addressing these challenges to improve the environmental sustainability of MRI is imperative. The purpose of this review is to discuss the challenges, opportunities, and the need for action to reduce the environmental impact of MRI and prepare for the effects of climate change. The approaches outlined are categorized as strategies to reduce greenhouse gas (GHG) emissions from MRI during production and use phases, approaches to reduce the environmental impact of MRI including the preservation of finite resources, and development of adaption plans to prepare for the impact of climate change. Co-benefits of these strategies are emphasized including lower GHG emission and reduced cost along with improved heath and patient satisfaction. Although MRI is energy-intensive, there are many steps that can be taken now to improve the environmental sustainability of MRI and prepare for the effects of climate change. On-going research, technical development, and collaboration with industry partners are needed to achieve further reductions in MRI-related GHG emissions and to decrease the reliance on finite resources. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 6.

Keywords: MRI; climate change; environment; sustainability.

FIGURE 1:

Summary of strategies to address environmental sustainability in MRI.

FIGURE 2:

Summary of power ranges for MRI scanner modes (a) and energy use for an MRI scanner over a 24-hour period (b).

FIGURE 3:

MRI power consumption trending line graphs during MRI examinations of the ankle using an identical imaging protocol at field strengths of 0.55T (a), 1.5T (b), and 3T (c). Energy consumption in kilowatt-hours (kWh) is visualized overall, as well as for individual pulse sequences, localizers, and adjustment scans. Total energy consumption of the entire imaging protocol is calculated by summing up data of individual sequences and the MRI scanner’s baseline power consumption between sequences.

FIGURE 4:

Low-field MRI examples. Side-by-side comparison of sagittal T2-weighted images of the lumbar spine at 0.55T (a) and 1.5T (b) in a 30-year-old healthy volunteer and coronal PD fat saturated images of the left knee at 0.55T (c) and 3T (d) in a 35-year-old male patient following a twisting injury. The medial collateral ligament tear (arrows in c and d) is identified at both field strengths.

FIGURE 5:

Strategies to address waste in MRI should follow a hierarchy of refuse, reduce, reuse, repurpose, recycle, and finally dispose.

FIGURE 6:

Summary of GBCA and waterbody contamination in the environment. Opportunities to decrease Gd and GBCA contamination are highlighted.

FIGURE 7:

Summary of key challenges and opportunities for environmental sustainability in MRI.