1. A method for quantifying an echo texture feature, comprising: obtaining an ultrasound image, wherein the ultrasound image comprises a plurality of pixels, wherein each pixel contains a pixel value; defining a region of interests on the ultrasound image and determining a regional standard deviation, wherein the regional standard deviation is the standard deviation of the pixel values of the pixels in the selected ROI; eliminating the pixels having the pixel value lower than a standard value in the selected ROI, wherein the standard value is a multiple of the regional standard deviation; generating a set of local statistical parameters for each of the pixels remaining in the selected ROI. A N th set of local statistical parameters is obtained from the pixel points within a local area composed of the N th pixel point and the pixel points adjacent the N th pixel in the selected ROI, and the N th pixel is one of the pixels remaining in the selected ROI, N is a natural number from 1 to the number of the pixels remaining in the selected ROI; and acquiring at least one echo texture index in accordance with the local statistical parameters.