True about screening mammography is

Mammography Soft tissue radiographs are taken by placing the breast in direct contact with ultrasensitive film and exposing it to low-voltage, high-amperage x-rays . The dose of radiation is approximately 0.1 cGy and, therefore, mammography is a very safe investigation. The sensitivity of this investigation increases with age as the breast becomes less dense. In total, 5% of breast cancers are missed by population-based mammographic screening programmes; even in retrospect, such carcinomas are not apparent. Thus, a normal mammogram does not exclude the presence of carcinoma. Digital mammography is being introduced, which allows manipulation of the images and computer-aided diagnosis. Tomo-mammography is also being assessed as a more sensitive diagnostic modality. Ref: Bailey and love 27th edition Pg no : 864