Abstract: A prone CT breast x-ray imaging system is described that can image a full breast to create a conventional 2D digital image in very high resolution (e.g. <=25 micron pixels). The system is capable of imaging the entire breast in 3D based on multiple projection views from a 1D or 2D detector. Data can be acquired and reconstructed with a limited number of views from limited angles or with conventional cone beam CT algorithms. The resulting 3D image enables the detection and diagnosis of fine micro calcifications and small masses as may be distributed throughout the breast, thus allowing radiologists to make an improved determination of malignancy as opposed to conventional 2D digital mammography. In addition, the injection of intravenous contrast in conjunction with or without pre and post contrast subtraction imaging provides a radiologist with morphologic information on the existing tumor burden in the breast.