[How to read a screening mammography (mammotest)].

The purpose of this chapter is to give to the radiologist some practical information in order to be able to read the mammotests, as they are performed in mass screening for breast cancer in France. The examples shown must help to detect as many small cancers as possible, without inflating the false positive rate. Screening mammotests can be read one by one (first reading), or by large series (second or third reading). To improve both the sensitivity and the specificity, reading technique should be strict, with correct fitting (viewboxes, ambiant light). For each case, a technical evaluation is performed (sharpness, contrast, breast projection), followed by the detection phase (asymmetry, abnormal density or calcifications or distorsion). Then, the image is analyzed (eliminating the typical benign conditions), and finally encoded to formalize the result: normal/suspicious for breast cancer. A good working method and a perfect knowledge of normal and pathologic appearances, allow us to reach the recommended rates for detected cancers and positive tests.