A diagnostic imaging system includes a high frequency electromagnetic energy source that emits a beam of high frequency electromagnetic energy toward an object to be imaged. An energy discriminating (ED) detector receives high frequency electromagnetic energy emitted by the high frequency electromagnetic energy source. The ED detector includes a first direct conversion layer and a second direct conversion layer. The first direct conversion layer comprises a first direct conversion material and the second direct conversion layer comprises a second direct conversion material that is different from the first direct conversion material. A data acquisition system (DAS) is operably connected to the ED detector and a computer operably connected to the DAS.