Energy use in MRI services can be reduced through operational changes and, where clinically appropriate, selection of lower energy sequences that provide comparable diagnostic information. An in-press article in Academic Radiology reports a one-month assessment of a single 3 T MRI scanner, examining how gradient systems, system electronics, operational status and sequence type contributed to electricity consumption. The assessment focuses on Scope 2 emissions linked to purchased electricity and addresses a practical gap in routine imaging operations. The findings show that radiology departments can use energy monitoring, scanner power modes and careful protocol review to reduce environmental impact while keeping diagnostic quality as the primary requirement.
Idle Operation Drives Energy Burden
The monitored scanner completed 790 individual sequence instances for 87 patients during the assessment period. Energy use was separated between the gradient system and system electronics, allowing active scanning to be distinguished from idle operation. During sequence acquisition, gradients accounted for the larger share of power demand. During idle periods, system electronics dominated, accounting for most energy use while the scanner was not acquiring images.
The difference between active and idle operation is important for operational planning. Although active scanning used more energy per unit of time, idle operation lasted much longer and therefore produced a larger cumulative energy burden. Non-business hours accounted for most overall energy expenditure despite limited procedural demand, with system electronics making up the dominant share during these periods. Leaving scanners in idle mode when not in use still consumed substantial electricity.
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The pattern points to two separate opportunities for radiology services. First, idle power demand can be addressed through low power modes during non-business hours when clinically and operationally feasible. Second, active scanning demand can be reduced through protocol review, because the energy profile of a sequence depends on both its technical requirements and its duration. Energy monitoring therefore gives departments a way to identify where routine scanner behaviour creates avoidable consumption in daily practice.
Sequence Duration Influences Efficiency
Sequence choice also contributed to variation in MRI energy use. The assessment compared clinically related sequences that may provide similar diagnostic information in selected settings. These comparisons did not imply that one sequence can always replace another. Instead, they identified where lower energy options may be appropriate when diagnostic utility, patient factors and the clinical question allow.
Several sequence pairs showed meaningful differences in per-sequence energy consumption. Fluid-attenuated inversion recovery consumed less energy than three-dimensional fluid-attenuated inversion recovery, while T2 turbo spin-echo-weighted fat-saturated imaging consumed less than short tau inversion recovery. T1 turbo spin-echo consumed less than Dixon imaging in the monitored data. T2 half-Fourier acquisition single-shot turbo spin-echo also showed lower consumption than conventional T2 turbo spin-echo, including in an abdominal and pelvic imaging subanalysis, although clinical context remains essential.
The main driver behind these differences was acquisition time. Across the comparisons, sequences with shorter acquisition times generally consumed less energy per completed sequence, even when per-minute consumption was similar. This makes total energy per sequence more relevant for clinical operations than instantaneous power alone, because imaging protocols require sufficient time to achieve diagnostic image quality. The highest total energy contribution came from frequently used sequences, particularly diffusion-weighted and diffusion tensor imaging, T2 turbo spin-echo, scout imaging, Dixon imaging and T1 turbo spin-echo. Their impact reflected frequent use as well as, in diffusion-weighted and diffusion tensor imaging, high gradient demand.
Operational Changes Need Clinical Safeguards
The assessment supports a combined approach to MRI energy conservation. Comprehensive energy monitoring can establish baseline consumption patterns before operational changes are introduced. Low power mode during non-business hours is a priority where scanner availability, emergency access and workflow can be preserved. Sequence optimisation can then be considered through collaboration between radiologists, MRI physicists and application specialists.
Technical changes that reduce sequence duration without compromising diagnostic quality may also reduce energy use. Possible approaches include parameter adjustments to minimise scan time, protocol standardisation that includes energy efficiency considerations, acceleration techniques and regular review of scanning protocols as newer energy-efficient technologies become available. AI acceleration techniques are included among the approaches considered for reducing scan duration, while diagnostic quality remains the controlling requirement.
The findings also define limits for implementation. Any substitution must remain case specific and under the radiologist responsible for protocoling or interpreting the examination.
Subspecialty requirements, patient factors and diagnostic priorities take precedence over energy considerations. The assessment also has practical limitations: chiller energy use was not directly measured, energy recording used 30-second intervals, breath-hold and free-breathing techniques were not systematically analysed, energy use was not categorised by anatomic site, and data came from a single 3 T scanner at one institution. Broader multicentre work would be needed to test generalisability across scanners, field strengths and clinical settings.
MRI energy conservation can be pursued without treating sustainability as separate from clinical governance. The strongest message is that idle operation, scanner power management and sequence duration all matter. Lower energy sequences may reduce consumption when they provide appropriate diagnostic information, but substitution is not a blanket policy. Energy monitoring, low power modes and careful protocol optimisation offer radiology departments practical ways to reduce environmental impact while keeping image quality, patient factors and clinical need at the centre of decision-making.
Source: Academic Radiology
Image Credit: iStock
References:
Scherer N, Wang F, Chang A et al. (2026) Energy Conservation in MRI: Sequence Selection and Operational Strategies. Academic Radiology: In Press.
