1. A system for imaging ultrasound scatterers, comprising: an ultrasound transducer array for transmitting ultrasound beams and detecting ultrasound echoes reflected at a multiplicity of sample volumes in a scan plane; means coupled to said ultrasound transducer array for acquiring raw acoustic sample data derived from ultrasound echoes reflected from each scan plane; first storage means for storing a respective image frame data set of raw acoustic sample data for each scan plane; histogram means for organizing at least one of said image frame data sets into a histogram data set; end-point determination means for determining first and second end points of a new map input range as a function of said histogram data set; second storage means for storing an old map having output values corresponding to respective input values of an old map input range greater than said new map input range; means for transforming said old map into a new map comprising output values corresponding to respective input values of said new map input range, said output values of said new map being derived from said output values of said old map; means for inputting said new map to said second storage means; means for applying the contents said second storage means to an image frame data set to form a mapped image frame data set; a display monitor comprising a multiplicity of pixels; and means for displaying said mapped image frame data set by controlling intensity values of said pixels on said display monitor.