[Diagnostic imaging for breast cancer]

With the westernization of the Japanese diet and way of life, the mortality due to breast cancer continues gradually to increase. This disease, however, is a type of cancer that can be well controlled by primary preventive measures and early detection. Numerous techniques of diagnostic imaging for breast cancer have been established, but the most common are mammography and ultrasonography. For X-ray mammography, a low tube voltage is necessary so that small differences in X-ray absorption by the various tissues within the breast may be detected, but when the surface dose is increased, it is a source of anxiety because of the possible development of secondary carcinoma. Ultrasonography of the breast, however, is free from the dangers of radiation exposure, and may be conducted in conjunction with palpation, thus representing a highly reliable approach. The diagnostic reliability of mammography and ultrasonography was investigated in 251 cases in which breast cancer was confirmed by these methods in a total of 752 outpatients who visited the Department of Breast Surgery of the Aichi Cancer Center Hospital in Nagoya, Japan. As a diagnostic procedure for breast cancer, mammography was shown to have a sensitivity of 89.2%, a specificity of 92.6%, and an accuracy rate of 91.5%, the respective values for the ultrasound technique being 84.9%, 88.9%, and 87.5%. These results are superior even to those of surgeons with 30 years of experience specializing in the breast (86.9%, 85.3%, and 85.8%), especially when tumors cannot be palpated.(ABSTRACT TRUNCATED AT 250 WORDS)