Evidence for Biot slow wave data in 3D ultrasound tomographic (3D UT) data from an orthopedic scan is shown by segmentation interior to Bone. Previous results have shown the quantitative accuracy of the 3D ultrasound volography method for ligaments, cartilage, tendons, skin, fat, muscle, etc. Interior to bone the SOS values are lower than expected. It is known that a slow compressional wave is predicted by Johnson-Biot theory which has speed of sound (SOS) values independently measured which are similar to our values based on segmentation for trabecular bone matrix interior to bone. Values for marrow are determined from segmentation and are commensurate with literature values as well. Concepts from algebraic topology are applied to the tomographic data (the first homotopy group of the N-torus, where N is the number of receiver elements in the array) and a quantitative comparison of the data redundancy with 2D algorithms is carried out. The use of algebraic topology gives a suitable context in which to understand phase unwrapping issues and leads to constraints on the distance between the data acquisition (DA) data levels and the frequencies used in the reconstruction. The data redundancy comparison applies to any 3D vs 2D comparison, e.g. 3D UT compared with MRI and shows the much larger size of the information contributing to a single voxel in the 3D vs 2D as long as the 3D model for wave propagation is used. The implications of this are discussed. Validation of attenuation variation with frequency is shown.
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