The apparatus of at least one embodiment includes an input unit, a storage unit, an output unit, and an interface to the imaging device, via which configuration parameters of the imaging device can be read out or transferred. A calculating unit either reads out the configuration parameters from the imaging device or sends the configuration parameters to the imaging device if they have been entered at the input unit by an operator, the configuration parameters being required for the purpose of specifying the quantity of a contrast medium. The calculating unit is so designed as to calculate, on the basis of the parameters that have been entered and/or read out and calculation formulas which are stored in the storage unit, the quantity of a contrast medium that is required for these parameters, and to display the quantity via the output unit.
