Breast lesions may, during their development, provide sonography signs can be difficult to view or are not very specific. They are called “subtle images”. Proximal (ductal) lesions are differentiated from distal (ductal-lobular) lesions. Proximal lesions are mainly inflammatory or infectious, altering the duct walls that evolve into ectasia and then fibrosis with possible acute episodes of plasmocyte mastitis or bacterial mastitis. The fibrovascular stalks of the papilloma accounts for the Doppler flow. Certain secretory forms of intra-ductal carcinoma may distend the structure of the milk ducts. The sonography of lesions of the ductal-lobular units are related to the degree of fibrosis, the atrophy or cell proliferation, and the disorganisation of the architecture. The extent of the fibrosis, or the cell density of certain tumours may modify the tissue hardness in elastography.