Quality assurance for non-contrast CT of the abdomen and pelvis during a period of supply chain disruption leading to iodinated contrast shortage in the emergency department setting

Abstract

Objectives: Iodinated contrast media (ICM) shortage crisis due to COVID-19 lockdowns led to a need for alternate imaging protocols consisting of non-contrast computed tomography (CT) for abdominal complaints and related trauma indications in emergency department (ED) settings. This quality assurance study aims to evaluate clinical outcomes of protocol modifications during ICM shortage and identify potential imaging misdiagnosis of acute abdominal complaints and related trauma. Material and Methods: The study included 424 ED patients with abdominal pain, falls, or motor vehicle collision (MVC)-related trauma who had non-contrast CT of the abdomen and pelvis in May 2022. We accessed the initial complaint, order indication, non-contrast CT results, any acute or incidental findings, and any follow-up imaging of the same body region with their results. We evaluated their association utilizing Chi-squared tests. We assessed sensitivity, specificity, and positive/negative predictive values using follow-up scan confirmation. Results: Across initial complaint categories, 72.9% of cases were abdominal pain, and 37.3% received positive findings. Only 22.6% of patients had follow-up imaging. Most confirmed original reports were for abdominal pain. We also found three reports of missed findings. There were significant associations between complaint categories and initial non-contrast CT report results (P < 0.001), as well as initial complaint categories and whether the patient received follow-up imaging or not (P < 0.004). No significant associations were found between follow-up imaging results and initial report confirmation. Non-contrast CT had 94% sensitivity and 100% specificity, with positive and negative predictive values 100% and 94%, respectively. Conclusion: Rate of missed acute diagnoses using non-contrast CT for patients presenting to the ED with acute abdominal complaints or related trauma has been low during the recent shortage, but further investigation would be needed to verify and quantify the implications of not routinely giving oral or intravenous contrast in the ED.