The normal breast and its variations in mammography.

The mammographic appearance of the breast varies along the lifetime due to physiological modifications or use of hormonal therapies. Density of the glandular tissue is due to amount of cellular elements of the gland and to hydratation of the tissues. Normal variations are encountered as for example breast asymmetry. The currently breast composition should be described with the BI-RADS lexicon classification. Mammary asymmetry is frequent and has to be differentiated from pathologic changes. A good mammographic technique is mandatory for an adequate visualisation of the breast tissues.