1. A method for mapping radiological image data from a source imaging system to a target imaging system comprising: obtaining sensitometric response data for both the source and the target imaging systems; identifying an anchor point that relates a specified source signal value to a specified target signal value; and applying a transform to map a range of source signal values to a corresponding range of target signal values, wherein the transform is defined according to the sensitometric response data obtained for both the source and the target imaging systems and according to the identified anchor point.