Ductal carcinoma in-situ (DCIS) has been visualized by 2D XDFI (X-ray dark-field imaging) and further by a 3D X-ray CT, and the data was acquired by the X-ray optics DEI (diffraction-enhanced imaging). A newly made algorithm was used for CT Data of 900 projections with interval of 0.2 degrees were used. Ductus lactiferi, microcalcification in a 3D form have been clearly visible. The spatial resolution available was approximately 30 μm.