Impact of iodinated contrast media conserving interventions and lessons for the future

Introduction: A severe shortage of iodinated contrast medium (ICM) has forced radiology departments around the world to implement strategies to reduce contrast utilization. The aim of this study was to evaluate the effect of these interventions on ordering practices and ICM consumption for computed tomography (CT). Methods: Our radiology department instituted several ICM-conserving interventions on 13^th May 2022, encompassing: (i) improved triage; (ii) diversion to alternative modalities and non-enhanced CT (NECT); and (iii) reduction in ICM dosing. The impact of these changes on contrast-enhanced CT (CECT) scan numbers, and ICM consumption in the first 28 days post-intervention, was quantified and compared with the preceding 12 months. Sub-analyses of CT pulmonary angiography (CTPA), abdominal and pelvic CECT (CECT AP), and ‘Code stroke’ CT numbers and the impact on alternative modalities was also performed. The t-test for unpaired samples was used to assess the statistical significance of change. Results: The average daily number of CECT (all), CECT (inpatient and ED), CTPA, CECT AP, and ‘Code stroke’ CT scans decreased significantly (P < 0.01), by 58.6%, 68.8%, 74.1%, 88.0%, and 37.5%, respectively. The number of NECT, NECT abdomen and pelvis (NECT AP), and nuclear medicine lung ventilation:perfusion (VQ) scans increased significantly (P < 0.01), by 41.6%, 608.2%, and 165.8%, respectively. ICM consumption also decreased significantly (P < 0.01), by 65.3% (75.8% for ED and inpatient scans). Conclusion: Interventions in CT alone, focused on improving patient triage to CECT while avoiding deferment of any outpatient oncology studies, have achieved an approximately two-thirds reduction in ICM consumption.