A method is disclosed for operating a hybrid medical imaging unit including a first imaging device of relatively high spatial resolution and a second nuclear medicine imaging device of relatively high sensitivity that respectively acquire imaging measurement signals from a common examination volume. In an embodiment of the method, during the current measurement signal acquisition of the second imaging device, the continuously acquired measurement signals are used to determine a region in the examination volume in which a region referred measurement signal acquisition is subsequently performed by the first examination device with use of a region referred measurement protocol.