Ultrasonic computed tomography for anisotropic materials characterization

Tomographic imaging principles have been successfully applied to the problem of recovering local material properties from acoustic wave propagation data for many years. While acoustic tomography has many features in common with its radiographic counterpart, there are additional complicating features (notably ray bending) which makes tomography more difficult with acoustic data. When anisotropy is included, the level of difficulty increases markedly. The problem of tomographic image reconstruction is discussed for anisotropic media. Particularly, attention is focused on alternative approaches to incorporate the directional dependence of material properties in the reconstruction algorithm. Also, techniques for extending existing tomography methods to recover multiple material parameter are presented