1. Contents -- 2. Mathematical foundations -- 3. Governing equations of elastodynamics -- 4. Constitutive equations, governing equations, elastodynamic energy conservation -- 5. Acoustics -- 6. Electromagnetism -- 7. Vector wave equations -- 8. Elastic plane waves in homogeneous materials -- 9. Reflection, transmission, and mode conversion of elastic plane waves at planar boundaries between homogenous nondissipative materials -- 10. Rayleigh surface waves -- 11. Plane wave spatial spectrum -- 12. Ultrasonic beams and wave packets -- 13. Point sources in homogeneous isotropic infinite space, elastodynamic source fields -- 14. Force density and dilatation rate sources on surfaces of homogeneous isotropic half-spaces, radiation fields of piezoelectric transducers -- 15. Scatterers in homogeneous istropic nondissipative infinite spaces -- 16. Inverse scattering : US-NDT imaging.