The present invention provides a volumetric computed tomography (VCT) system capable of producing data for reconstructing an entire three-dimensional (3D) image of a subject during a single rotation without suffering from cone beam artifacts. The VCT system comprises an array of source positions distributed along a line parallel to an axis of rotation, a plurality of collimators, and an array of x-ray detectors. In a preferred embodiment, a reversed imaging geometry is used. A 2D array of source positions provides x-rays emanating from each focal spot toward an array of detectors. The x-rays are restricted by a collimator array and measured by a detector array separately per each source position. The axial extent of the source array and the detector array are comparable to or larger than the axial extent of the portion of the object being imaged.