Adaptive speckle reduction of ultrasound images based on maximum likelihood estimation

A method has been developed in this paper to gain effective speckle reduction in medical ultrasound images.To exploit full knowledge of the speckle distribution, here maximum likelihood was used to estimate speckleparameters corresponding to its statistical mode. Then the results were incorporated into the nonlinearanisotropic diffusion to achieve adaptive speckle reduction. Verified with simulated and ultrasound images,we show that this algorithm is capable of enhancing features of clinical interest and reduces speckle noisemore efficiently than just applying classical filters. To avoid edge contribution, changes of contrast-to-noiseratio of different regions are also compared to investigate the performance of this approach.