Answer
Radiology staff observe you for at least 30 minutes because most immediate hypersensitivity reactions occur shortly after contrast administration.
Sources for this answer
- Magnevist 2mmol/l solution for injection — Current selected SmPCemc · Summary of Product Characteristics
- NHSNHS · NHS medicine guidance
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.