An imaging system includes a collimator assembly, a detector assembly and a control device. The collimator assembly is configured to collimate photons emitted from an imaged subject. The collimator assembly may include a plurality of slit-plates and a plurality of slats parallel to a transverse plane of the imaging system. Each of the plurality slit-plates may include one or more slits configured to collimate the photons in a first direction. The detector assembly is configured to generate signals based on the collimated photons. The control device is configured to place the plurality of slit-plates in a plurality of locations to provide a plurality of fields of view of the imaging system.
