New screening technique could provide more reliable breast cancer detection

Scientists have successfully completed an initial trial of a new, potentially more reliable, technique for screening breast cancer using ultrasound. In standard mammography, only about 30 percent  of suspicious lesions turn out to be malignant, leading to many unnecessary biopsies. Ultrasound is safe, low cost, and already extensively used in other applications. However the quality of the images is not yet good enough for reliable breast cancer diagnoses. Different biological tissues have different sound speeds, and this affects the time it takes for sound waves to arrive at the detector, which distorts the image. The new method works by detecting the intensity of ultrasonic waves. Intensity is converted to heat that is then sensed by a thin membrane of pyroelectric film, which generates a voltage output dependant on the temperature rise. Imaging detectors based on this new principle should be much less susceptible to the effects caused by the uneven sound speed in tissues.