[Comparative estimation of the limitations of mammography and echography in senologic practice].

Mammography and breast ultrasonography are complementary examinations. The combination of the two examinations can provide an accurate diagnosis, which mammography alone is unable to do. Ultrasonography is particularly important in the examination of dense breasts, especially for the visualization of sonolucent or hypoechogenic formations. However, ultrasonography should not be performed alone, as it is unable to visualize microcalcifications. It can not be used as a screening test and it would be a professional error to perform only a clinical examination and ultrasonography, as a large number of diagnoses would be missed. Two essential points should be stressed: 30% of carcinomas have microcalcifications; amongst these 30%, many lesions are small and impalpable and they may not be seen on ultrasonography in a fatty breast. 40% of occult cancers are detected by the microcalcifications identified on mammography, which remains the key to breast investigations. Ultrasonography compensates for some of the deficiencies of radiography and can be very useful in dense breasts, in cystic or hypoechogenic structures. It can also be used to guide aspiration biopsy of non palpable lesions and for the pre-operative localization of impalpable lesions with abnormal echostructure, which are not visible on mammography.