...
Additionally, Hounsfield unit measurements are also provided, taken as an average of a 5x5 pixel region centered at the center of the crosshairs overlying the image.
Size measurements of the calculus can be obtained by glancing at the magnification panel most suitable for evaluating the structure of interest, in this case, the lower left panel which is at 4x magnification.
US and international patents are pending for the magnified measure tool.
...