Extending the Utility of the Parabolic Approximation in Medical Ultrasound Using Wide Wide-Angle Diffraction Modeling
Abstract: Wide-angle angle parabolic models are commonly used in geophysics and underwater acoustics but have seen little application in medical ultrasound. Here, a widewide angle model for continuous continuous-wave high-intensity intensity ultrasound beams is derived, which approximates the dif diffraction fraction process more accurately than the commonly used Khokhlov-Zabolotskaya Zabolotskaya-Kuznetsov Kuznetsov (KZK) equation without increasing implementation complexity or computing time. A method for preventing the high spatial frequencies often present in source boundary con conditions ditions from corrupting the solution is presented. Simulations of shallowly focused axisymmetric beams using both the wide-angle angle and standard parabolic models are compared to assess the accuracy with which they model diffraction effects. The wide-angle wide model proposed here offers improved focusing accuracy and less error throughout the computational domain than the standard parabolic model, offering a facile method for extending the utility of existing KZK codes.