Digital Breast Tomosynthesis is a technique that uses conventional x-rays and a digital detector to obtain a variable number of images from the acquisition of multiple low-dose projections of the breast. The reconstructed images show a plane of the breast in sharp focus, while tissue above and below appears out of focus [3,4].

Various vendors are undergoing clinical trials, but up to now there is no universally accepted technology.

General characteristics of a DBT unit are:

 - the presence of a moving x-ray source with an arc-like motion. Different angular range and a continuous or step-and-shoot acquisition may be used;

 - a flat-panel digital detector, that may consist of selenium, which is usually preferred, or of cesium iodide crystal on an amorphous silicon layer. The detector may be stationary or move with the tube;

 - reconstruction algorithms, similar to those of CT, to reconstruct images from the data obtained [5].

The dose of a single DBT acquisition is reported to be approximately equal to that of a two view Digital Mammography, but new technologies may help reduce the radiation exposure.

The aim of introducing DBT in clinical practice, as stated by more than one study already published [3,5], is to reduce diagnostic doubts (false negative and false positive) related to superimposition of glandular tissue, particularly in women with dense breasts. Up to now, the majority of articles regarding Tomosynthesis concentrated on technical and physical aspects or on the performance of this new technique compared to Digital Mammography.

There is a general consensus in the application of ACR BIRADS in description of breast findings [1], but some typical aspect must be considered.