1. A method for processing a fluoroscopic image, said method comprising: scanning an object with an imaging system including at least one radiation source and at least one detector array; acquiring a plurality of dark images to generate a baseline image; acquiring a plurality of lag images subsequent to the baseline image; determining a plurality of parameters of a power law using at least one lag image and at least one baseline image; performing a log-log extrapolation of the power law including the determined parameters.