Phantom and Human Experiments for Breast Cancer Detection by Ultrasound Transmission Technique

Summary

A new technique named the ultrasound transmission technique has been proposed by the authors. The idea was developed from the clinical findings that sound velocity in breast cancer is higher than in normal tissue by 49-90 m/s. Phantom experiments were conducted. Plexiglas (PMMA) plates 3 mm, 2 mm, or 1 mm thick were put into a cubic container (86 × 86 × 86 mm) filled with degassed water. In the echogram, the apparent distance between the back wall of the container and transducer was shortened because of the higher velocity of sound waves in plexiglas (2700 m/s) than degassed water (1500 m/s). This result showed the validity of the method. A breast to be examined can be sandwiched between a planar ultrasound transducer and reflector plate. Similar experiments were performed using a slice of pork (42 mm thick) instead of degassed water. The shortening of the reflector was apparent. The forearm of a human volunteer was also examined with plexiglas 2mm or 1 mm thick with similar results, suggesting the validity of the method.