Abstract: An apparatus for generating gamma emission images including two gamma cameras mounted to a gantry wherein the gantry includes two moveable rings and a locking mechanism which can lock the two moveable rings together in one of two separate configurations. Each camera is mounted to a separate one of the two moveable rings and defines a camera axis, the two camera axes together defining a configuration angle and two different configuration angles are possible. By locking the two moveable rings together a single motor and associated hardware and software can be used to rotate both cameras about an imaging axis simultaneously.