Quantification of Imaging Suite–Level Energy Patterns in MRI, CT, and PET/CT to Guide Energy Efficiency

Background The urgency for systemic change in how care, particularly energy-intensive advanced imaging services, is delivered and managed is evident, as the emissions associated with these services are adversely affecting human health. Although the energy demand from the main power supply (ie, electricity directly powering the imaging hardware) has been well characterized, imaging suite-level quantification that includes the heating, ventilation, and air conditioning (HVAC) and chilled water subsystems is not yet understood. Purpose To comprehensively assess imaging suite-level energy by quantifying energy demands from main power, HVAC, and chilled water subsystems. Materials and Methods Power, temperature, and flow meters were permanently installed in four imaging suites (3-T MRI, 1.5-T MRI, CT, and PET/CT) to measure energy patterns for the main power, HVAC, and MRI chilled water subsystems in an outpatient facility. Software was developed to calculate suite-level energy consumption over a 30-day period. Descriptive statistics were used to summarize power and energy consumption values across all subsystems (main power, HVAC, and chilled water) and imaging suites. Results Projected suite-level total annual energy consumption was 277.9, 211.5, 54.8, and 117.2 MWh for the 3-T MRI, 1.5-T MRI, CT, and PET/CT suites, respectively, equivalent to the annual electricity use of 25.8, 19.6, 5.1, and 10.9 average U.S. homes. Main power dominated MRI suite energy demand, accounting for 64.63% (179.6 of 277.9 MWh per year) and 72.72% (153.8 of 211.5 MWh per year) of the total for 3-T and 1.5-T MRI, respectively. The HVAC (9.97% [27.7 of 277.9]; 17.45% [36.9 of 211.5], respectively) and chilled water (25.40% [70.6 of 277.9]; 9.83% [20.8 of 211.5], respectively) subsystems also contributed. In CT and PET/CT suites, HVAC was the primary driver of demand (68.8% [37.7 of 54.8 MWh per year]; 64.76% [75.9 of 117.2 MWh per year], respectively), with the remaining attributed to main power. Conclusion Suite-level quantification revealed modality- and subsystem-specific energy patterns, where main power dominated MRI suite energy, and HVAC dominated CT and PET/CT suite energy. © RSNA, 2026