Timing in a medical imaging system. The system comprises a magnetic resonance imaging (MRI) subsystem and a non-MRI subsystem. Operation of the non-MRI subsystem involves a timing signal within a radio frequency (RF) cabin of the MRI subsystem. Basing each non-MRI subsystem timing signal on a time base common between the MRI subsystem and the non-MRI subsystem. The non-MRI subsystem can be a medical imaging subsystem. The non-MRI medical imaging subsystem can be a positron emission tomography (PET) subsystem. Each non-MRI subsystem timing signal that based on the common time base can be created using the same model of equipment used for creating timing signals in the MRI subsystem. At least one stage of the non-MRI subsystem timing signal based on the common time base can be created using the same equipment used for creating timing signals in the MRI subsystem.