Costs and imaging delays associated with acute reactions to contrast material: A single-center retrospective study

Acute reactions to iodinated contrast material (ICM) and gadolinium-based contrast agents (GBCAs) are routinely encountered during CT and MR exams, but their associated direct medical costs and radiology practice workflow delays remain largely unknown. The purpose of this five-year, single-center retrospective study was to determine the costs and the Radiology departmental delays associated with acute ICM and GBCA reactions.

Contrast-enhanced CT and MR (CECT and CEMR) examinations performed from November 1, 2019, to October 31, 2024 at our institution were included. Acute reactions were identified as allergic-like or physiologic and categorized by severity using established ACR criteria. Drug, procedural, and hospitalization costs were estimated using 2025 CMS and US Department of Veterans Affairs databases. Delays were quantified by comparing time from exam start to departmental exit for exams with and without reactions.

A total of 363,671 CECT exams and 253,860 CEMR exams were included, with 1099 acute ICM (789 allergic-like, 310 physiologic) and 521 acute GBCA reactions (321 allergic-like, 200 physiologic) identified. A minority of patients received billable medication or a procedure for their treatment (321 CECT, 29%; 107 CEMR, 21%). Median costs were modest ($15 for CECT; $1.66 for CEMR), but varied substantially by severity (severe reactions up to $238,029) and outcome (ED patient = $326, Admitted patient = $13,942). Acute ICM and GBCA reactions resulted in a median additional time of 25 minutes (IQR 11-43 min) and 27 minutes (IQR 8-59 min) in Radiology, respectively.

Acute ICM and GBCA reactions contribute to additional estimated direct medical costs and imaging delays that increase with reaction severity. Our findings help quantify how these adverse events increase direct and indirect estimated direct medical costs and negatively affect Radiology workflow; providing decision makers with important economic and operational context.