The current invention is generally related to a data acquisition and or image processing method and system for acquiring and or processing sparse channel data. The sparse channel is implemented in a data acquisition system having a predetermined wider pitch between the adjacent detector cells than that in the currently available imaging systems at least in one predetermined channel direction. The sparse channel is also defined to encompass various imaging modalities including CT, positron emission tomography (PET) and positron emission tomography-computed tomography (PET/CT). The sparse channel data is acquired by the sparse channel data acquisition system, and an image is reconstructed from the sparse channel data according to a predetermined iterative reconstruction technique.
