A method for sensing a level of ionizing radiation directed from a radiation source through a subject and toward an imaging detector, the method executed at least in part by a logic processor, obtains positional coordinate data that is indicative of at least a portion of the subject to be exposed to radiation and that defines a radiation measurement area relative to the subject. The method assigns one or more sensing elements to sense radiation within the radiation measurement area. A measurement signal is acquired from each of one or more assigned sensing elements.
