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

Review Article: Green Management of IBD-New Paradigms for an Eco-Friendly Approach

BACKGROUND

The worldwide prevalence of inflammatory bowel disease (IBD) is increasing, with its potential evolution as a global disease and a consequent increase in its burden on healthcare systems. These estimates do not factor in the 'real' price of IBD, which, beyond curbing career aspirations, instilling social stigma, and impairing the quality of life in patients, could also significantly affect the environment.

AIM

To highlight potential areas for intervention and develop management strategies aimed at minimising environmental impacts in the field of IBD over time.

METHODS

Various aspects of IBD care (organisation of IBD centres, diagnostics and therapeutics) are examined from an environmental sustainability perspective.

RESULTS

Each stage, from the patient's means of transport to the hospital to the physician's diagnostic and therapeutic decisions, contribute to CO2 and waste production. Strategies to contain the environmental impact are feasible. Some are easy to implement, such as ensuring the appropriateness of the diagnostic and therapeutic pathway for patients; others need to be implemented in synergy with healthcare providers' policies and pharmaceutical companies.

CONCLUSIONS

With an inevitable increase in the number of patient visits, endoscopies, laboratory testing, and long-term therapeutic strategies for IBD, the clinical community should be aware of environmental concerns and investigate possible strategies to reduce the environmental impact of IBD care.

Beyond Do No Harm: Introduction to Green Radiology

ABSTRACT

In 2021, the Human Rights Council declared that having a clean, healthy, and sustainable environment is a human right. According to the WHO, 24% of deaths are attributable to environmental health risks and are largely preventable. Current predictions show that rising emissions will be linked to an enormous healthcare burden, especially for high-risk populations and historically disadvantaged communities. The US healthcare industry accounts for nearly 18% of its GDP and is a major consumer of resources. The largest healthcare-related source of greenhouse gas emissions is from the supply chain, including pharmaceuticals, other chemicals, food, and the transportation required to mobilize them accounting for 80% of emissions, with only 20% of emissions from purchased energy and the facilities directly. As a field, radiology has historically monitored its impact in terms of radiation exposure and thermal effects but has not focused on other pollutants, greenhouse gas emissions, or waste. Although tackling large issues such as climate change and pollution seems daunting, we can start by raising awareness through education, investigation, and advocacy. In this review, we discuss a systems-based approach to addressing climate change from the federal to the local level focusing on the potential role of the radiologist.

Imperative for a health-centred focus on climate change in radiology

Climate change negatively impacts individual and population-level health through multiple pathways, including poor air quality, extreme heat and changes in infectious disease. These health effects will lead to higher health system and medical imaging utilisation. At the same time, the delivery of radiology services generates substantial greenhouse gas emissions. Mitigation strategies to reduce the environmental impact of medical imaging and adaptation strategies to build resiliency to current and future impacts of climate change in radiology should be centred on human health. A health-centred response in radiology reinforces the role of radiologists as physicians and emphasises the opportunity for medical imaging to promote health and advance our understanding of climate-related health effects. This review discusses the need for a health-centred focus on climate change in radiology, including the effects of climate change on human health and health systems, intersection of climate change with health equity, health benefits of climate action and opportunities to leverage medical imaging to improve human health.

Reducing the Energy Consumption of Magnetic Resonance Imaging and Computed Tomography Scanners: Integrating Ecodesign and Sustainable Operations

ABSTRACT

This review aims to provide valuable insights into how energy consumption in magnetic resonance imaging (MRI) and computed tomography (CT) scanners can be effectively monitored, managed, and reduced, thereby contributing to more sustainable medical imaging practices. Demand for advanced imaging technologies such as MRI and CT scanners continues to increase, and understanding the resultant impact on greenhouse gas emissions requires a thorough evaluation of their energy consumption. This review examines the energy monitoring and consumption characteristics of MRI and CT scanners, highlighting potential approaches for energy savings. An overview of MRI and CT principles, hardware components, and their associated energy consumption is provided. After addressing the technical aspects, the hardware and software requirements essential for accurate energy metering are detailed. Baseline measurements of energy consumption data are then provided as a foundation to understand current usage patterns and identify areas for improvement. Ongoing efforts to reduce energy consumption are categorized into 3 main strategies: operations, scanner design enhancements, and active scanning techniques, including accelerated MRI protocols. Ultimately, we emphasize that achieving sustainability in medical imaging requires collaboration across disciplines. By incorporating eco-friendly design in new imaging equipment, we can reduce the environmental impact, promote sustainability, and set a health care industry standard for a healthier planet.

Cardiac MRI Pectoralis Muscle Thickness as a Measure of Sarcopenia: Prognostic Significance, Interreader Agreement, and Physiologic Correlation

Purpose To evaluate pectoralis muscle thickness at routine cardiac MRI as a marker of sarcopenia, including prognostic significance for major adverse cardiac events (MACE), interobserver agreement, and correlation with physiologic parameters. Materials and Methods This retrospective cohort study included adult patients undergoing cardiac MRI for assessment of suspected cardiomyopathy between October 2018 and February 2020. Measurements of maximum pectoralis major thickness were performed by two experienced radiologists using axial images at the level of the carina. A random subset of 50 patients were re-evaluated to assess intra- and interobserver agreement. The primary end point was MACE, defined as a composite of cardiac death, resuscitated sudden cardiac death, appropriate implantable cardioverter defibrillator discharge, or hospitalization for heart failure. Prognostic significance of pectoralis major thickness measurements for MACE was assessed using Cox proportional hazard models, and correlation between muscle thickness measurements and cardiopulmonary exercise testing (CPET), performed within 1 year of MRI, was assessed using Spearman correlation. Results The study included 1045 patients (mean age, 50 years ± 17 [SD]; 642 male, 403 female). After median follow-up of 3.3 years (IQR: 2.3-3.9 years), MACE occurred in 66 patients. In multivariable models adjusted for patient age, left ventricular ejection fraction, late gadolinium enhancement, and cardiomyopathy cause, pectoralis major muscle thickness was predictive of MACE in both male (hazard ratio [HR], 0.89 [95% CI: 0.85, 0.94]; P < .001) and female patients (HR, 0.85 [95% CI: 0.76, 0.96]; P = .008), with improved model fit in nested models. Pectoralis muscle thickness measurements had excellent intra- and interobserver agreement (intraclass correlation coefficient, 0.99 and 0.95, respectively) and correlated with absolute peak oxygen uptake (r = 0.65, P < .0001) and oxygen uptake efficiency slope (r = 0.61, P < .001) in the subset who underwent CPET within 1 year of MRI (n = 258). Conclusion Pectoralis major muscle thickness at routine cardiac MRI is a simple, reproducible measure of sarcopenia that was associated with MACE occurrence in male and female patients and correlated with CPET parameters. Keywords: Cardiac, Cardiomyopathies, MR Imaging Supplemental material is available for this article. © RSNA, 2024.

Increased Emergency Department Medical Imaging: Association with Short-Term Exposures to Ambient Heat and Particulate Air Pollution

Background Climate change adversely affects human health, resulting in higher demand for health care services. However, the impact of climate-related environmental exposures on medical imaging utilization is currently unknown. Purpose To determine associations of short-term exposures to ambient heat and particulate air pollution with utilization of emergency department medical imaging. Materials and Methods In this retrospective time-stratified case-crossover study, daily imaging utilization counts from four emergency departments were linked to local daily environmental data-including fine particulate matter with 2.5-µm or smaller aerodynamic diameter (PM2.5) and ambient temperature-over 10 years (January 2013 to December 2022). Conditional Poisson regression models were used to evaluate the associations between daily imaging utilization and environmental exposures on the same day and each of the 7 days preceding imaging, lag days 0-7, controlling for day of the week, month, and year. Moving averages of mean daily PM2.5 and temperature were calculated to account for lagged exposure effects. Imaging counts were also stratified by modality (CT, radiography, US, and MRI). Results In an analysis of 1 666 420 emergency department imaging studies, a rise of 10 °C in the 2-day moving average of mean daily temperature and a rise of 10 μg/m3 in the 3-day moving average of mean daily PM2.5 were associated with overall imaging utilization increases of 5.1% (incidence rate ratio [IRR], 1.051; 95% CI: 1.045, 1.056) and 4.0% (IRR, 1.040; 95% CI: 1.035, 1.046), respectively. Heat exposure days (mean temperature >20 °C) and air pollution exposure days (mean PM2.5 >12 μg/m3) were associated with same-day excess absolute risk of 5.5 and 6.4 imaging studies per 1 million people at risk per day, respectively. Heat exposure days and air pollution exposure days were associated with increased utilization of radiography (excess relative risk, 2.7% [P < .001] and 2.1% [P < .001], respectively) and CT (excess relative risk, 2.0% [P = .001] and 2.7% [P < .001]) but not US (P = .14 and P = .14) or MRI (P = .70 and P = .65). Conclusion Short-term exposures to ambient heat and particulate air pollution were associated with increased utilization of radiography and CT but not US or MRI. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Vosshenrich in this issue.

Preoperative prediction of diffuse glioma type and grade in adults: a gadolinium-free MRI-based decision tree

OBJECTIVES

To develop a gadolinium-free MRI-based diagnosis prediction decision tree (DPDT) for adult-type diffuse gliomas and to assess the added value of gadolinium-based contrast agent (GBCA) enhanced images.

MATERIALS AND METHODS

This study included preoperative grade 2-4 adult-type diffuse gliomas (World Health Organization 2021) scanned between 2010 and 2021. The DPDT, incorporating eleven GBCA-free MRI features, was developed using 18% of the dataset based on consensus readings. Diagnosis predictions involved grade (grade 2 vs. grade 3/4) and molecular status (isocitrate dehydrogenase (IDH) and 1p/19q). GBCA-free diagnosis was predicted using DPDT, while GBCA-enhanced diagnosis included post-contrast images. The accuracy of these predictions was assessed by three raters with varying experience levels in neuroradiology using the test dataset. Agreement analyses were applied to evaluate the prediction performance/reproducibility.

RESULTS

The test dataset included 303 patients (age (SD): 56.7 (14.2) years, female/male: 114/189, low-grade/high-grade: 54/249, IDH-mutant/wildtype: 82/221, 1p/19q-codeleted/intact: 34/269). Per-rater GBCA-free predictions achieved ≥ 0.85 (95%-CI: 0.80-0.88) accuracy for grade and ≥ 0.75 (95%-CI: 0.70-0.80) for molecular status, while GBCA-enhanced predictions reached ≥ 0.87 (95%-CI: 0.82-0.90) and ≥ 0.77 (95%-CI: 0.71-0.81), respectively. No accuracy difference was observed between GBCA-free and GBCA-enhanced predictions. Group inter-rater agreement was moderate for GBCA-free (0.56 (95%-CI: 0.46-0.66)) and substantial for GBCA-enhanced grade prediction (0.68 (95%-CI: 0.58-0.78), p = 0.008), while substantial for both GBCA-free (0.75 (95%-CI: 0.69-0.80) and GBCA-enhanced (0.77 (95%-CI: 0.71-0.82), p = 0.51) molecular status predictions.

CONCLUSION

The proposed GBCA-free diagnosis prediction decision tree performed well, with GBCA-enhanced images adding little to the preoperative diagnostic accuracy of adult-type diffuse gliomas.

KEY POINTS

Question Given health and environmental concerns, is there a gadolinium-free imaging protocol to preoperatively evaluate gliomas comparable to the gadolinium-enhanced standard practice? Findings The proposed gadolinium-free diagnosis prediction decision tree for adult-type diffuse gliomas performed well, and gadolinium-enhanced MRI demonstrated only limited improvement in diagnostic accuracy. Clinical relevance Even inexperienced raters effectively classified adult-type diffuse gliomas using the gadolinium-free diagnosis prediction decision tree, which, until further validation, can be used alongside gadolinium-enhanced images to respect standard practice, despite this study showing that gadolinium-enhanced images hardly improved diagnostic accuracy.

The environmental effects of non-invasive cardiac imaging

The healthcare sector is a major contributor to the universal climate footprint, of this a significant proportion is attributable to medical imaging and further to dedicated cardiac imaging. The increasing availability and utility of cardiac imaging techniques for prognosis, diagnosis and management raises concerns for the impact of these investigations on the environment. Our objective was to review the published literature assessing the environmental impact of non-invasive imaging modalities within cardiology, subsequently helping guide physicians toward a more sustainable approach to cardiac imaging and improved awareness of the environmental impact of healthcare within this field. We conducted a systematic review of studies measuring the environmental impact of non-invasive cardiac imaging. A total of 8 studies were included in the final analysis. Cardiac imaging has a significant environmental impact, which varies by modality: lowest for echocardiography and highest for MRI. As a whole this field represents a significant contributor to climate-related threats to human health, which we should strive toward harm minimisation. This may be mitigated through the conscious utilisation of energy consumption and contrast media, as well as healthcare worker education and quality improvement to guide imaging choice based on environmental impact alongside conventional determinants such as patient characteristics, clinical guidelines and cost (visual abstract).

A semi-automatic analytical methodology for characterizing the energy consumption of MRI systems using load duration curves

BACKGROUND AND PURPOSE

Magnetic resonance imaging (MRI) scanners are a major contributor to greenhouse gas emissions from the healthcare sector, and efforts to improve energy efficiency and reduce energy consumption rely on quantification of the characteristics of energy consumption. The purpose of this work was to develop a semi-automatic analytical methodology for the characterization of the energy consumption of MRI systems using only the load duration curve (LDC). LDCs are a fundamental tool used across various fields to analyze and understand the behavior of loads over time.

METHODS

An electric current transformer sensor and data logger were installed on two 3T MRI scanners from two vendors, termed M1 (outpatient scanner) and M2 (inpatient/emergency scanner). Data was collected for 1 month (7/11/2023 to 8/11/2023). Active power was calculated, assuming a balanced three-phase system, using the average current measured across all three phases, a 480 V reference voltage for both machines, and vendor-provided power factors. An LDC was constructed for each system by sorting the active power values in descending order and computing the cumulative time (in units of percentage) for each data point. The first derivative of the LDC was then computed (LDC'), smoothed by convolution with a window function (sLDC'), and used to detect transitions between different system modes including (in descending power levels): scan, prepared-to-scan, idle, low-power, and off. The final, segmented LDC was used to measure time (% total time), total energy (kWh), and mean power (kW) for each system mode on both scanners. The method was validated by comparing mean power values, computed using the segmented 1-month LDC, for each nonproductive system mode (i.e., prepared-to-scan, idle, lower-power, and off) against power levels measured after a deliberate system shutdown was performed for each scanner (1 day worth of data).

RESULTS

The validation revealed differences in mean power values <1.4% for all nonproductive modes and both scanners. In the scan system mode, the mean power values ranged from 29.8 to 37.2 kW and the total energy consumed for 1 month ranged from 11 106 to 14 466 kWh depending on the scanner. Over the course of 1 month, the portion of time the scanners were in nonproductive modes ranged from 76% to 80% across scanners and the nonproductive energy consumption ranged from 8010 to 6722 kWh depending on the scanner. The M1 (outpatient) scanner consumed 99.9 and 183.9 kWh/day in idle mode for weekdays and weekends, respectively, because the scanner spent 23% more time proportionally in idle mode on the weekends.

CONCLUSIONS

A semi-automatic method for quantifying energy consumption characteristics of MRI scanners was introduced and validated. This method is relatively simple to implement as it requires only power data from the scanners and avoids the technical challenges associated with extracting and processing scanner log files. The methodology enables quantitative evaluation of the power, time, and energy characteristics of MRI scanners in scan and nonproductive system modes, providing baseline data and the capability of identifying potential opportunities for enhancing the energy efficiency of MRI scanners.

Canadian Association of Radiologists Statement on Planetary Health Education in Radiology

The health of Canadians is already impacted by climate change due to wildfire smoke, heat domes, floods, droughts, and the changing distribution of vector borne disease. The healthcare sector contributes to climate change, accounting for approximately 4.6% of annual greenhouse gas emissions in Canada. Healthcare teams have a responsibility and opportunity to reduce harm by limiting emissions and waste, and engaging the public in understanding the planetary health links between clean air and water, a stable climate, a healthy planet and human health. Transformation of Canadian healthcare to a low carbon, climate resilient system will be enhanced by physician engagement and leadership. Cornerstones to physician participation include knowledge of the anthropogenic etiology of the climate crisis, the human health impacts, and the contribution providing healthcare makes to the climate crisis. Integration of climate change knowledge into the Canadian Radiology educational curricula is essential to position radiologists to lead transformative change in mitigation and adaptation of the healthcare system to the climate crisis. This statement is intended to provide guidelines to optimize education and research for current and future Canadian radiologists, and builds on existing planetary healthcare education publications and the Canadian Association of Radiologists Statement on Environmental Sustainability in Medical Imaging.

Footprints in the scan: reducing the carbon footprint of diagnostic tools in urology

PURPOSE OF REVIEW

There is an ever-growing focus on climate change and its impact on our society. With healthcare contributing a sizeable proportion of carbon emissions, the sector has a duty to address its environmental impact. We highlight the recent progress, current challenges, and future prospects for reducing the carbon footprint in diagnostic urology, specifically for imaging, without compromising patient care.

RECENT FINDINGS

The review is separated into four key areas of recent research: the design of a green radiology department, considering both infrastructural as well as behavioural changes that promote sustainability; individual scanners, where we provide an update on recent technological advancements and changes in behaviour that may enhance sustainable use; responsible resource allocation, where it is important to derive the maximal benefit for patients through the smallest use of resources; the recent research regarding single versus reusable urologic endoscopes as a case example.

SUMMARY

We offer an overview of the present sustainability landscape in diagnostic urology with the aim of encouraging additional research in areas where existing practices may be challenged. To protect the environment, attention is drawn to both more simple steps that can be taken as well as some more complex and expensive ones.

Cardiac Cine MRI Using a Commercially Available 0.55-T Scanner

Purpose To compare parameters of left ventricular (LV) and right ventricular (RV) volume and function between a commercially available 0.55-T low-field-strength cardiac cine MRI scanner and a 1.5-T scanner. Materials and Methods In this prospective study, healthy volunteers (May 2022 to July 2022) underwent same-day cine imaging using both scanners (0.55 T, 1.5 T). Volumetric and functional parameters were assessed by two experts. After analyzing the results of a blinded crossover reader study of the healthy volunteers, 20 participants with clinically indicated cardiac MRI were prospectively included (November 2022 to February 2023). In a second blinded expert reading, parameters from clinical 1.5-T scans in these participants were compared with those same-day 0.55-T scans. Results are displayed as Bland-Altman plots. Results Eleven healthy volunteers (mean age: 33 years [95% CI: 27, 40]; four of 11 [36%] female, seven of 11 [64%] male) were included. Very strong mean correlation was observed (r = 0.98 [95% CI: 0.97, 0.98]). Average deviation between MRI systems was 1.6% (95% CI: 0.3, 2.9) for both readers. Twenty participants with clinically indicated cardiac MRI were included (mean age: 55 years [95% CI: 48, 62], six of 20 [30%] female, 14 of 20 [70%] male). Mean correlation was very strong (r = 0.98 [95% CI: 0.97, 0.98]). LV and RV parameters demonstrated an average deviation of 1.1% (95% CI: 0.1, 2.1) between MRI systems. Conclusion Cardiac cine MRI at 0.55 T yielded comparable results for quantitative biventricular volumetric and functional parameters compared with routine imaging at 1.5 T, if acquisition time is doubled. Keywords: Cardiac, Comparative Studies, Heart, Cardiovascular MRI, Cine, Myocardium Supplemental material is available for this article. ©RSNA, 2024.

Role of green and sustainable practices in shaping the future of medical imaging technology: A cross-sectional multi-stakeholder analysis among students, radiographers, and academic experts

INTRODUCTION

The detection and treatment of diseases like COVID, diabetes, cancer, cardiovascular conditions, etc., have made medical imaging technology more necessary, so it is expected that the demands of imaging modalities are also increasing and are major contributors to carbon emissions in the healthcare industry. Hence, the Radiology departments, like the rest of the healthcare industry should adapt the procedures to become more sustainable.

METHODS

A total of 1016 respondents completed the online survey to assess the perception, current practices, and challenges in adopting green and sustainable practices in medical imaging. The radio technologists, teaching faculties, and students of medical imaging were recruited for the study. The survey tool was distributed to the closed groups through social media and emails.

RESULTS

The majority of participants (66.6%) highlighted the importance of green and sustainable practices in medical imaging whereas only 21.06% of participants seem to have implemented these practices. Most of the participants give positive responses on the use of zero-lead aprons (77%), refurbished medical systems (85.8%), and eco-friendly packaging (89.5%). The mixed response was received from waste segregation and energy-saving measures. The majority (60.3%) of them have no formal education or training. However, they have a good attitude towards the willingness to adopt green practices.

CONCLUSIONS

There is a gap between perception and implementation of green and sustainable practices due to leadership and information barriers. Comprehensive training for stakeholders of medical imaging is crucial to fully integrate sustainability practices, possibly through webinars or educational modules.

IMPLICATIONS FOR PRACTICE

The study's findings shed light on how important medical imaging stakeholders view green and sustainable practices as well as potential obstacles to their implementation at the local level whilst suggesting the need for exclusive training on these practices to promote sustainability.

Canadian Association of Radiologists Statement on Environmental Sustainability in Medical Imaging

Immediate and strategic action is needed to improve environmental sustainability and reduce the detrimental effects of climate change. Climate change is already adversely affecting the health of Canadians related to worsening air pollution and wildfire smoke, increasing frequency and intensity of extreme weather events, and expansion of vector-borne and infectious illnesses. On one hand, radiology contributes to the climate crisis by generating greenhouse gas emissions and waste during the production, manufacture, transportation, and use of medical imaging equipment and supplies. On the other hand, radiology departments are also susceptible to equipment and infrastructure damage from flooding, extreme temperatures, and power failures, as well as workforce shortages due to injury and illness, potentially disrupting radiology services and increasing costs. The Canadian Association of Radiologists' (CAR) advocacy for environmentally sustainable radiology in Canada encompasses both minimizing the detrimental effects that delivery of radiology services has on the environment and optimizing the resilience of radiology departments to increasing health needs and changing patterns of disease on imaging related to climate change. This statement provides specific recommendations and pathways to help guide radiologists, medical imaging leadership teams, industry partners, governments, and other key stakeholders to transition to environmentally sustainable, net-zero, and climate-resilient radiology organizations. Specific consideration is given to unique aspects of medical imaging in Canada. Finally, environmentally sustainable radiology programs, policies, and achievements in Canada are highlighted.

Cardiovascular Imaging, Climate Change, and Environmental Sustainability

Environmental exposures including poor air quality and extreme temperatures are exacerbated by climate change and are associated with adverse cardiovascular outcomes. Concomitantly, the delivery of health care generates substantial atmospheric greenhouse gas (GHG) emissions contributing to the climate crisis. Therefore, cardiac imaging teams must be aware not only of the adverse cardiovascular health effects of climate change, but also the downstream environmental ramifications of cardiovascular imaging. The purpose of this review is to highlight the impact of climate change on cardiovascular health, discuss the environmental impact of cardiovascular imaging, and describe opportunities to improve environmental sustainability of cardiac MRI, cardiac CT, echocardiography, cardiac nuclear imaging, and invasive cardiovascular imaging. Overarching strategies to improve environmental sustainability in cardiovascular imaging include prioritizing imaging tests with lower GHG emissions when more than one test is appropriate, reducing low-value imaging, and turning equipment off when not in use. Modality-specific opportunities include focused MRI protocols and low-field-strength applications, iodine contrast media recycling programs in cardiac CT, judicious use of US-enhancing agents in echocardiography, improved radiopharmaceutical procurement and waste management in nuclear cardiology, and use of reusable supplies in interventional suites. Finally, future directions and research are highlighted, including life cycle assessments over the lifespan of cardiac imaging equipment and the impact of artificial intelligence tools. Keywords: Heart, Safety, Sustainability, Cardiovascular Imaging Supplemental material is available for this article. © RSNA, 2024.

Approaches to reduce medical imaging departments' environmental impact: A scoping review

INTRODUCTION

Global warming stands as a paramount public health issue of our time, and it is fundamental to explore approaches to green medical imaging departments/(MID). This study aims to map the existing actions in the literature that promote sustainable development in MID towards the promotion of environmental impact reduction.

METHODS

Following the JBI methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR), this literature search was conducted on MEDLINE, Embase and CINAHL to encompass studies published after 2013. Combinations of keywords and relevant terms related to environmental sustainability, recycling, medical waste, and greening radiology were applied for this review. Three independent reviewers screened abstracts, titles, and eligible full-text. Disagreement was solved through consensus.

RESULTS

38 out of 4630 articles met all inclusion criteria, and four additional articles were identified and added through reference search. A third of the studies included were published after 2022, and most were conducted in developed countries (36/41). Articles focused on computed tomography (9/41), magnetic resonance imaging (6/41), interventional radiology (4/41), conventional radiography (4/41), ultrasound (2/41), mixed modalities (10/41), or not applicable to an imaging modality (6/41). Four principal categories were identified to decrease ecological footprint: energy consumption, waste management, justification and environmental pollution.

CONCLUSION

To minimise the environmental impact of MIDs raising awareness and promoting education is fundamental. Examinations must be justified adequately, energy consumption must be reduced, and waste management practices need to be implemented. Further studies are required to prioritise the most effective strategies, supporting decision-making among stakeholders.

IMPLICATIONS FOR PRACTICE

Several strategies are already possible to implement to reduce the environmental impact of MIDs and improve the healthcare outcomes for patients.

Applications of Urinary Extracellular Vesicles in the Diagnosis and Active Surveillance of Prostate Cancer

Prostate cancer is the most common non-cutaneous cancer among men in the UK, causing significant health and economic burdens. Diagnosis and risk prognostication can be challenging due to the genetic and clinical heterogeneity of prostate cancer as well as uncertainties in our knowledge of the underlying biology and natural history of disease development. Urinary extracellular vesicles (EVs) are microscopic, lipid bilayer defined particles released by cells that carry a variety of molecular cargoes including nucleic acids, proteins and other molecules. Urine is a plentiful source of prostate-derived EVs. In this narrative review, we summarise the evidence on the function of urinary EVs and their applications in the evolving field of prostate cancer diagnostics and active surveillance. EVs are implicated in the development of all hallmarks of prostate cancer, and this knowledge has been applied to the development of multiple diagnostic tests, which are largely based on RNA and miRNA. Common gene probes included in multi-probe tests include PCA3 and ERG, and the miRNAs miR-21 and miR-141. The next decade will likely bring further improvements in the diagnostic accuracy of biomarkers as well as insights into molecular biological mechanisms of action that can be translated into opportunities in precision uro-oncology.

Planetary Health and Radiology: Why We Should Care and What We Can Do

Climate change adversely affects the well-being of humans and the entire planet. A planetary health framework recognizes that sustaining a healthy planet is essential to achieving individual, community, and global health. Radiology contributes to the climate crisis by generating greenhouse gas (GHG) emissions during the production and use of medical imaging equipment and supplies. To promote planetary health, strategies that mitigate and adapt to climate change in radiology are needed. Mitigation strategies to reduce GHG emissions include switching to renewable energy sources, refurbishing rather than replacing imaging scanners, and powering down unused scanners. Radiology departments must also build resiliency to the now unavoidable impacts of the climate crisis. Adaptation strategies include education, upgrading building infrastructure, and developing departmental sustainability dashboards to track progress in achieving sustainability goals. Shifting practices to catalyze these necessary changes in radiology requires a coordinated approach. This includes partnering with key stakeholders, providing effective communication, and prioritizing high-impact interventions. This article reviews the intersection of planetary health and radiology. Its goals are to emphasize why we should care about sustainability, showcase actions we can take to mitigate our impact, and prepare us to adapt to the effects of climate change. © RSNA, 2024 Supplemental material is available for this article. See also the article by Ibrahim et al in this issue. See also the article by Lenkinski and Rofsky in this issue.

Contrast Media-driven Anthropogenic Gadolinium: Knowns and Unknowns

Gadolinium-based contrast agents (GBCAs) have augmented the capabilities of MRI, which has led to their widespread and increasing use in radiology practice. GBCAs are introduced into the environment through disposal of unused product and elimination after intravenous injection, both primarily via liquid dispersion into the environment. This human introduction of gadolinium into the environment, referred to as anthropogenic gadolinium, is associated with the detection of gadolinium in water systems, raising concerns for potential adverse impact and prompting certain mitigation actions. This article summarizes the existing knowledge and problem scope, conveys the relevant underlying chemical principles of chelate dissociation, and offers an inferred perspective that the magnitude of the problem is most unlikely to cause human harm. The merits and limitations regarding possible mitigation tactics, such as collecting urine after GBCA administration, use of lower-dose high-relaxivity macrocyclic GBCAs, and the option for virtual contrast-enhanced examinations, will be discussed. Finally, the potential for monitoring gadolinium uptake in bone will be presented, and recommendations for future research will be offered. © RSNA, 2024 See also the article by Ibrahim et al in this issue. See also the article by McKee et al in this issue.

Energy and Greenhouse Gas Emission Savings Associated with Implementation of an Abbreviated Cardiac MRI Protocol

Supplemental material is available for this article. See also the article by Lenkinski and Rofsky in this issue. See also the article by McKee et al in this issue.

Radiology: Cardiothoracic Imaging Highlights 2023

Radiology: Cardiothoracic Imaging publishes novel research and technical developments in cardiac, thoracic, and vascular imaging. The journal published many innovative studies during 2023 and achieved an impact factor for the first time since its inaugural issue in 2019, with an impact factor of 7.0. The current review article, led by the Radiology: Cardiothoracic Imaging trainee editorial board, highlights the most impactful articles published in the journal between November 2022 and October 2023. The review encompasses various aspects of coronary CT, photon-counting detector CT, PET/MRI, cardiac MRI, congenital heart disease, vascular imaging, thoracic imaging, artificial intelligence, and health services research. Key highlights include the potential for photon-counting detector CT to reduce contrast media volumes, utility of combined PET/MRI in the evaluation of cardiac sarcoidosis, the prognostic value of left atrial late gadolinium enhancement at MRI in predicting incident atrial fibrillation, the utility of an artificial intelligence tool to optimize detection of incidental pulmonary embolism, and standardization of medical terminology for cardiac CT. Ongoing research and future directions include evaluation of novel PET tracers for assessment of myocardial fibrosis, deployment of AI tools in clinical cardiovascular imaging workflows, and growing awareness of the need to improve environmental sustainability in imaging. Keywords: Coronary CT, Photon-counting Detector CT, PET/MRI, Cardiac MRI, Congenital Heart Disease, Vascular Imaging, Thoracic Imaging, Artificial Intelligence, Health Services Research © RSNA, 2024.

Environmental Sustainability and AI in Radiology: A Double-Edged Sword

According to the World Health Organization, climate change is the single biggest health threat facing humanity. The global health care system, including medical imaging, must manage the health effects of climate change while at the same time addressing the large amount of greenhouse gas (GHG) emissions generated in the delivery of care. Data centers and computational efforts are increasingly large contributors to GHG emissions in radiology. This is due to the explosive increase in big data and artificial intelligence (AI) applications that have resulted in large energy requirements for developing and deploying AI models. However, AI also has the potential to improve environmental sustainability in medical imaging. For example, use of AI can shorten MRI scan times with accelerated acquisition times, improve the scheduling efficiency of scanners, and optimize the use of decision-support tools to reduce low-value imaging. The purpose of this Radiology in Focus article is to discuss this duality at the intersection of environmental sustainability and AI in radiology. Further discussed are strategies and opportunities to decrease AI-related emissions and to leverage AI to improve sustainability in radiology, with a focus on health equity. Co-benefits of these strategies are explored, including lower cost and improved patient outcomes. Finally, knowledge gaps and areas for future research are highlighted.