Light from an object such as a cell moving through an imaging system is collected and dispersed so that it can be imaged onto a time delay and integration (TDI) detector. The light can be emitted from a luminous object or can be light from a light source that has been scattered or not absorbed by the object or can include a light emission by one or more probes within or on the object. Multiple objects passing through the imaging system can be imaged, producing both scatter images and dispersed images at different locations on one or more TDI detectors.