1. A method comprising: acquiring several 2D x-ray tomosynthesis projection images Tp of a patient's breast taken at different angles of an imaging x-ray beam relative to the breast; computer-processing the projection images Tp into reconstructed slice images Tr representing respective 3D slices of the breast; each of said slice images Tr comprising respective pixel values of a respective array of pixels; wherein the pixels of at least one of said slice images Tr represent respective slice volumes that differ in size from those represented by the pixels of at least another one of said slice images Tr at least in planes to which said slices conform; and selectively displaying said slice images Tr on a computer display unit.