An adverse drug reaction (ADR) following intravascular administration of contrast agents (CA), including iodine-based contrast media (ICM), gadolinium-based contrast agents (GBCA), or ultrasound contrast agents (USCA), is defined as a harmful and unintended response to a CA. In this context, ‘response’ implies that a causal relationship between a medicinal product and an adverse event is at least a reasonable possibility [1].