Breast tumor is the most common tumor in the world. The most important method to reduce the mortality due to breast tumor is diagnosed and found as early as possible. Imaging technology is one of the most important me...Breast tumor is the most common tumor in the world. The most important method to reduce the mortality due to breast tumor is diagnosed and found as early as possible. Imaging technology is one of the most important means to help doctors diagnose tumor early. This paper first simply introduces the common imaging technology. Then the mechanism and application of the ultrasonic elastic imaging technology in the diagnosis of breast tumor are summarized and discussed detailly. The methods for image treatment are introduced also. At last the development trend is analyzed. It is shown that the ultrasonic imaging technology is the most convenient and the cheapest relative to other imaging technologies such as nuclear magnetic imaging (NMI) and computer tomography (CT). Especially the ultrasonic elastic imaging technology can provide not only imaging information but also mechanism parameters, which helps to improve the accuracy of diagnosis obviously. Therefore, the ultrasonic elastic imaging technology is worthy of being studied further. More effective image analysis method is required.展开更多
Ultrasonic velocities have been measured in single phase Bi_1.7 Pb_0.3Sr2CaCu2O8+x and Bi1.7Pb0.3Sr2Ca2O10+x polycrystalline samples. Anomalous changes of both longitudinal and transverse velocities were observed near...Ultrasonic velocities have been measured in single phase Bi_1.7 Pb_0.3Sr2CaCu2O8+x and Bi1.7Pb0.3Sr2Ca2O10+x polycrystalline samples. Anomalous changes of both longitudinal and transverse velocities were observed near 200K, which indicates that some structural phase transitio might occur. The elastic constants of these samples have been determined from the measured ultrasonic velocity data, which are much smaller than those of YBa2 Cu3 O7-y and BaTiO3, manifesting that the interlayer coupling will dramatically decrease when the c - axes of the unit cells of these perovstite-like multilayer ceramics increase. The values of Poisson ratio, however, of those ceramics are very close, implying similar interatomic bonding forces. Corrected to void-free state, the Debye temperature of these materials is estirnated as 270 ±20k. The temperature dependence of Debye temperatures for these materials is also calculated by using the same method and reported for the first time.展开更多
文摘Breast tumor is the most common tumor in the world. The most important method to reduce the mortality due to breast tumor is diagnosed and found as early as possible. Imaging technology is one of the most important means to help doctors diagnose tumor early. This paper first simply introduces the common imaging technology. Then the mechanism and application of the ultrasonic elastic imaging technology in the diagnosis of breast tumor are summarized and discussed detailly. The methods for image treatment are introduced also. At last the development trend is analyzed. It is shown that the ultrasonic imaging technology is the most convenient and the cheapest relative to other imaging technologies such as nuclear magnetic imaging (NMI) and computer tomography (CT). Especially the ultrasonic elastic imaging technology can provide not only imaging information but also mechanism parameters, which helps to improve the accuracy of diagnosis obviously. Therefore, the ultrasonic elastic imaging technology is worthy of being studied further. More effective image analysis method is required.
基金The project is supported by the National Center of ResearchDevelopment on Supperconductivity of China+1 种基金the National Science Foundation of Chinathe Third World Academy of Sciences
文摘Ultrasonic velocities have been measured in single phase Bi_1.7 Pb_0.3Sr2CaCu2O8+x and Bi1.7Pb0.3Sr2Ca2O10+x polycrystalline samples. Anomalous changes of both longitudinal and transverse velocities were observed near 200K, which indicates that some structural phase transitio might occur. The elastic constants of these samples have been determined from the measured ultrasonic velocity data, which are much smaller than those of YBa2 Cu3 O7-y and BaTiO3, manifesting that the interlayer coupling will dramatically decrease when the c - axes of the unit cells of these perovstite-like multilayer ceramics increase. The values of Poisson ratio, however, of those ceramics are very close, implying similar interatomic bonding forces. Corrected to void-free state, the Debye temperature of these materials is estirnated as 270 ±20k. The temperature dependence of Debye temperatures for these materials is also calculated by using the same method and reported for the first time.
