When Lumbar Spine MRIs Aren’t Indicated, the Waste Isn’t Just Clinical

Multicenter review links scans ordered outside ACR criteria to preventable emissions

BY LYNN ANTONOPOULOS July 10, 2026

Abdul Cader

Hernandez

Reducing low-value imaging has long been a priority for improving patient care and controlling costs. New research adds another dimension: unnecessary imaging can carry a measurable environmental toll, and it may be larger than clinicians might expect.

“Healthcare-related emissions represent a substantial and growing share of our global carbon footprint,” said Isa Abdul Cader, MD, a diagnostic radiology resident at Loma Linda University in California. “We hoped to quantify what we suspect but rarely measure: the environmental cost of care that was never indicated.”

To examine that impact, Dr. Abdul Cader and colleagues conducted a multicenter retrospective review within Los Angeles’ large safety-net county healthcare system, evaluating the impact of low-value lumbar spine (L-spine) MRIs.

Over a six-week representative period in 2023, these exams accounted for 1,479 kg of carbon dioxide equivalents (CO₂e)—a standard way to express the warming impact of greenhouse gases as a single number. Projected over a year, emissions would exceed 12,800 kg, comparable to driving more than 32,500 miles in a gas-powered vehicle.

The findings highlight how adherence to established imaging guidelines can simultaneously improve patient outcomes and reduce the environmental footprint of care.

“Stewardship of planetary health is, at its core, stewardship of patient health,” Dr. Abdul Cader said. “Radiology in particular is accelerating as a central modality in both diagnostics and treatment, which makes it a prime and urgent target for these efforts.”

Dr. Abdul Cader and his team evaluated 534 lumbar spine MRI exams performed across four centers. They identified 19% as low value based on American College of Radiology (ACR) appropriateness criteria for low back pain.

The team collected additional preliminary data on the results of non-indicated imaging but did not factor them into the analysis which focused on appropriateness criteria adherence rather than diagnostic outcomes.

To quantify the impact, the researchers used scanner log data from 3T and 1.5T systems obtained by Andrew Hernandez, PhD, a diagnostic clinical and research medical physicist from the UC Davis Health, calculating energy consumption at the exam level and combined those findings with estimates of patient travel-related emissions derived from zip code data.

Low-value scans consumed 650.7 kWh of energy, (360 kg of CO₂e).

Clinical Consequences Align with Environmental Costs

The study reinforces a well-established clinical message: early MRI for nonspecific low back pain rarely improves outcomes and may contribute to harm. Dr. Abdul Cader and his team note that prior research has linked non-adherent imaging to increased downstream testing, higher rates of intervention and even worse pain outcomes.

“Our findings add an environmental layer to that argument,” he said. “Adhering to appropriateness criteria isn't a tradeoff between patient welfare and sustainability; instead, it advances both simultaneously.”

That alignment may help strengthen the case for more consistent guideline adherence among referring providers.

Importantly, Dr. Abdul Cader stressed that ACR appropriateness criteria are designed to preserve access to imaging when clinically indicated.

“Red flag symptoms, including a history of malignancy, prolonged steroid use, neurological deficits or signs of cauda equina syndrome, all continue to warrant early MRI,” he said. “In this context, guideline adherence isn't about withholding care but delivering the right care to the right patient at the right time.”

While the study focused narrowly on lumbar spine MRI within a single healthcare system, Dr. Abdul Cader emphasized that it’s important for his colleagues in radiology to appreciate the scope of what the study represents: a single modality, encompassing a handful of protocols, for a limited study indication, across one county healthcare system.

“Even at that focused scale, the misallocation of resources is measurable and meaningful,” he said. “There are undoubtedly countless other use cases across radiology where we could ask the same questions and potentially find similar results.”

The findings suggest that radiologists are well positioned to lead efforts in identifying and reducing low-value imaging across modalities and clinical scenarios.

“It is our responsibility as radiologists, as the experts in clinical imaging, to identify those areas, advocate for guideline adherence and take ownership of stewardship in its fullest sense,” Dr. Abdul Cader emphasized.

“It is our responsibility as radiologists, as the experts in clinical imaging, to identify those areas, advocate for guideline adherence and take ownership of stewardship in its fullest sense.”

— ISA ABDUL CADER, MD

Patient Travel Drives Most Imaging-Related CO₂e

Even more striking than the energy consumption by scanners was a finding related to patient transportation, which contributed 1,119 kg CO₂e, roughly 90% of the total.

“The most unanticipated finding was that emissions from patient transportation significantly outpaced those associated with the scans themselves,” Dr. Abdul Cader said.

Patient transportation emissions were estimated based on using zip code-based assumptions, and the transportation mode was not confirmed at the individual level.

Even with that limitation, the findings shift the focus of sustainability efforts beyond the scanner. However, the apparent gap between travel emissions and scan emissions reflects the limits of what the researchers measured for the MRI itself.

“Care must be taken when interpreting these results, as only Scope 1 emissions related to power consumption of the MRI scanners was included in the analysis,” Dr. Hernandez noted.

“The practical assumption is that efforts focused solely on reducing direct MRI usage, while valuable, address only a fraction of the problem,” Dr. Abdul Cader added.

Awareness as a Catalyst for Change

Looking ahead, Dr. Abdul Cader pointed to awareness as the most immediate and impactful lever for change.

“If I could change one thing tomorrow, it would be a focus on awareness of the issue of low-value imaging across the healthcare system,” he said. “The recognition of the issue and its downstream impacts would ideally be the catalyst for change.”

Dr. Abdul Cader said that awareness could take multiple forms, including integrating environmental considerations into clinical decision-making, tracking low-value imaging as a quality metric and reinforcing the role of appropriateness criteria in everyday practice.

The findings also underscore a broader challenge in applying population-based appropriateness criteria to individual patient care, where clinicians must weigh guideline recommendations against the risk of missing serious conditions and understand the evidence supporting their diagnostic performance.

“Institutions should understand that an unnecessary scan carries costs to both the healthcare system and the planet,” he added. “Technical interventions such as clinical decision support tools or prior authorization only work durably when the underlying culture is aware of, and values appropriate ordering.”