Green's function method for modeling nonlinear three-dimensional pulsed acoustic fields in diagnostic ultrasound including tissue-like attenuation

The iterative nonlinear contrast source (INCS) method, developed previously to predict the nonlinear acoustic pressure field excited by a medical diagnostic phased array transducer in a lossless medium, is extended to deal with media showing attenuation of a frequency power law type. For a linear case, comparison shows an excellent agreement between the results of the extended INCS method and the FieldII program. For a nonlinear case, the INCS method is used to show that the axial field profile of the second harmonic component in a medium with a frequency power law attenuation with a power b = 1.14 differs considerably from the field profiles in a lossless medium and in a medium with b = 2, i.e. square power law attenuation.