The Great Contrast Shortage of 2022-Lessons learnt in Australia

Introduction: Computed tomography (CT) imaging is one of the most commonly used diagnostic tools. Iodine-based contrast media (IBCM) are frequently administered intravenously to improve soft tissue contrast in a wide range of CT scans. Supply chain disruptions triggered by the SARS-CoV-19 pandemic led to a global shortage of IBCM in mid-2022. The purpose of this study was to explore the impact of this shortage on the delivery of healthcare in Western Australia.

Methods: We performed a single-centre retrospective analysis of the provision of CT studies, comparing historical patterns to the shortage period. We focussed our attention on the total number of CT scans (noncontrast CT [NCCT] and contrast-enhanced CT [CECT]) and also specifically CT pulmonary angiogram (CTPA) and CT neck angiogram with or without inclusion of circle of Willis (CTNA) examinations. We also examined whether a decrease was compensated by increasing frequency of alternate examinations such as ventilation/perfusion (V/Q) scans, carotid Doppler ultrasound studies and Magnetic Resonance Angiograms (MRAs).

Results: Since 2012, there has been an approximate linear increase in the frequency of CT examinations. During the period of contrast shortage, there was an abrupt drop-off by approximately 50% in the CECT, CTPA and CTNA groups compared with the preceding 6 weeks (49%, 55% and 44%, respectively, with P < 0.001 in all cases). During the contrast shortage, the frequency of V/Q scans increased fivefold (from 13 to 65; P < 0.001). However, the provision of carotid Doppler ultrasound studies and MRAs remained approximately stable in frequency across recent time intervals.

Conclusion: Our findings demonstrate that the IBCM shortage crisis had a very significant impact on the delivery of healthcare. While V/Q scans could (partially) substitute for CTPA studies in suspected pulmonary emboli, there appeared to be no valid alternative for CTNA studies in stroke calls. The unexpected and critical shortage of IBCM forced healthcare professionals to conserve resources, prioritise indications, triage patients based on risk, explore alternate imaging strategies and prepare for similar events recurring in the future.