A method is disclosed for the prediction of a likely contrast medium behavior for a contrast medium-assisted examination of an object under investigation. In an embodiment, the method includes detecting patient-specific blood flow behavior data in a pre-measurement making use of a defined examination protocol and determining an individual impulse response function from the blood flow behavior data; detecting a pre-measured heart rate signal associated with the pre-measurement; and predicting the likely contrast medium behavior based on the individual impulse response function, the pre-measured heart rate signal and a current examination protocol, and a currently detected heart rate signal. A method for activation of a medical imaging system is also disclosed. Also disclosed are a device for predicting a likely contrast medium behavior, a control device with a device of this type for an imaging system, and an imaging system with a control device.