A method is disclosed for determining at least one PET parameter for a PET examination in a combined magnetic resonance/PET scanner designed for isocentric measurement. In at least one embodiment, at least one acquisition time for the PET examination is determined as a PET parameter from magnetic resonance data, recorded for determining patient-specific examination parameters for a magnetic resonance examination, and/or from at least one patient-specific information value derived therefrom, and is displayed and/or used for controlling the scanner.