Abstract: A sample for diagnosis of breast cancer can be prepared by isolating a ductal fluid sample from one duct of a breast of a patient. The isolated ductal fluid is not mixed with ductal fluid from any other duct of the breast. Generally the target duct is not spontaneously discharging. The isolated ductal fluid sample can be examined to determine the presence or absence of a marker associated with cancer or pre-cancer. An isolated ductal fluid sample not mixed with ductal fluid from any other duct of the breast permits identification of the duct which is diseased and provides increased sensitivity for existing diagnostic and analytic techniques.

Abstract: An ultrasonic diagnostic imaging system receives echo signals from a transducer for digital processing and image formation. An analog to digital converter converts the analog echo signals to digital signal samples. The dynamic range of the analog to digital converter is more efficiently used for harmonic imaging and saturation of the analog to digital converter is more effectively prevented by attenuating the fundamental signal content of echo signals prior to analog to digital conversion.