Ultrasound transmission computed tomography of the breast.

A preliminary clinical study of ultrasound transmission computed tomography of the breast (UTCTB) was undertaken to evaluate its capacity in the detection of breast abnormalities and to establish criteria for distinguishing benign from malignant lesions. Only patients with palpable and/or mammographically evident lesions were selected for study; complete analysis was accomplished in 78 cases. Visual and computer interpretations of reconstructed UTCTB scans were based on changes in speed of sound wave transmission and attenuation between the suspicious area and the surrounding tissue. In the computer-aided classification, discriminant functions were derived to predict the presence or absence of carcinoma. Visual analysis was subject to a low sensitivity. The presence of high speed transmission within a lesion usually indicated malignancy, although the converse was not true. Computer-aided preliminary screening of UTCTB scans by a trained technician may have the potential of contributing to interpretation accuracy; however, this finding must be highly qualified, given the methodologic constraints of the study.