A helical CT scanner for imaging an object is provided. The helical CT scanner includes an X-ray emitter configured to emit X-ray beams towards the object, and a detector array positioned opposite the X-ray emitter, the detector array including a plurality of discrete detector blocks arranged in a two-dimensional grid, each detector block including a plurality of pixels, wherein at least one first gap is defined between adjacent detector blocks in a first direction, and wherein at least one second gap is defined between adjacent detector blocks in a second direction. The helical CT scanner further includes a processing device communicatively coupled to said detector array, said processing device configured to reconstruct an image of the object based on image data acquired using said detector array.