Surgery for Obesity and Related Diseases: I. A Novel Approach to the Quantification of the Longitudinal Speed of Sound and Its Potential for Tissue Characterization.

Described here is a method to determine the longitudinal speed of sound in speckle-dominated ultrasound images. The method is based on the concept that the quality of an ultrasound image is maximized when the beamformer's speed of sound matches the speed in the medium. The method captures the quality of the ultrasound image using two quantitative image-quality metrics: image brightness and sharpness around the intended focal zone. The proposed method requires no calibration, is computationally efficient and is deployable on commercial ultrasound systems without hardware or software modifications. Ex vivo testing on tissue-mimicking phantoms indicates the method's accuracy in predicting the true speed of sound to within 1% of ground truth values.