The dynamic range describes the range of x-ray intensities a detector can differentiate. A high dynamic range provides the discrimination between small differences in x-ray attenuation.
A current CT scanner has approximately a dynamic range of 1,000,000 to 1 and 1,100 views or projections a second.

Process of conversion of continuous (analog) signals, such as the detected radiation (voltage), into numbers. This is carried out with an analog to digital converter. There are two kinds of discretization involved: the voltage is only measured (sampled) at particular discrete times and only voltages within a particular range and separated by a particular minimum amount can be distinguished. Voltages beyond this range are said to exceed the dynamic range of the digitizer.