A method for the characterization of the echostructures of normal and pathological breast tissues

Since a valid macroscopic investigation fundamentally cannot exist without its basis in microscopy, we are seeking to identify characteristic echo structures by means of acoustical microscopy at frequencies of 600 MHZ and 1 GHZ in order to better understand ultrasonography in everyday practice and to determine reliable and specific imaging characteristics of the different components of breast tissues. We have studied slices of mammary tissue 5-10 microns thick which had been removed during surgery. Acoustical imaging has to be performed in transmission mode as well as reflection mode. The intrinsic acoustic contrast is more than sufficient to obtain good visualization of different tissue components of the mammary gland. We noted, however, that even if the microscopic acoustic images were of good quality--often as good as light microscopy--certain tissue components such as the epithelium are irregularly visualized. It appears that the effective visualization of a structure depends entirely upon this acoustical environment.