1. A cone beam computerized tomography (CBCT) system comprising: a radiation source for emitting a cone beam of radiation in a beam direction towards an object; a detector for detecting said cone beam of radiation; a positioner for moving said radiation source and said object according to a scanning trajectory; and a controller in communication with said positioner, said controller operable to operate said radiation source according to a sampling pattern that includes intersections of the scanning trajectory and a reconstruction trajectory, wherein motion of said radiation source is substantially confined to a spherical shell, and wherein said positioner is operable to move said radiation source at speed higher than a highest speed of the object by a factor of at least 10, and wherein a largest angular discrepancy between any vector in a range of the scanning trajectory and a nearest sample of the scanning trajectory does not exceed 10°.