Design: Retrospective single-centre cohort over five years
Population: 617,531 contrast-enhanced CT and MR examinations; 1,620 acute reactions
Primary outcome: Direct medical cost and added department time per reaction
Effect: Median added time 25 min (CT) and 27 min (MR); admitted patient about $13,942

A five-year single-centre study (JACR, 17 October 2026) covered 363,671 contrast-enhanced CT and 253,860 contrast-enhanced MR examinations, with 1,099 acute reactions to iodinated contrast and 521 to gadolinium-based agents, classified by ACR severity.

Most patients needed no billable treatment (29% of CT and 21% of MR reactions did). Median direct cost was small - about $15 for CT and under $2 for MR - but rose sharply with severity, to about $326 for an emergency department visit, about $13,942 for an admission, and up to $238,029 for a single severe reaction. Reactions added a median 25 minutes (CT) and 27 minutes (MR) to the patient's time in the department.

The costs are US estimates and will differ elsewhere, but the time cost transfers: a reaction disrupts the list behind it. Both are arguments for proportionate risk assessment and for a team well drilled to treat reactions quickly.

Screen for prior contrast reactions before every enhanced study
Expect a reaction to cost a slot of about half an hour on the list
Keep emergency drugs and a reaction algorithm in every contrast room
Record reaction type and severity precisely to guide future imaging

Why it matters

It turns contrast safety into a measurable operational cost that departments can plan around.

The statistics, in plain English

Medians describe the typical reaction, which is minor; the very high maximum costs come from a handful of severe cases. Costs were modelled from US payer databases, so the dollar figures are estimates rather than billed amounts.