The clinical epidemiological investigation of diagnostic modalities in breast cancer detection--a comparison of ultrasonography and mammography.

We reviewed the medical records and images of 39 women with palpable breast masses, including 18 cases with breast cancer and 21 cases with benign breast mass, to compare diagnostic accuracy and clinical agreement between ultrasonography and mammography in breast cancer detection. We showed that the operating characteristics of ultrasonography, including sensitivity, specificity and positive likelihood ratio, were superior to that of mammography. We also confirmed that the established malignant criteria for malignancy, including lobulated shape, irregular contour and non-uniform internal echo in ultrasonography, and stellate mass in mammography, were statistically significant in distinguishing breast cancer from benign breast lesion. Moreover, the interobserver agreement kappa of ultrasonography and mammography were 0.64 and 0.59, respectively. Ultrasonography was also superior to mammography in attaining clinical agreement between the different observers in breast cancer detection.