K-edge subtraction using an energy-resolving position-sensitive detector

Digital Subtraction Angiography is an important technique used to image arterial blood flow using an introduced contrast agent. K-edge subtraction uses contrast-agents with a K-edge feature to acquire the same information but requires knowledge of the X-ray energy and so is usually conducted using synchrotron radiation. However, given a detector that measures position and energy – rather than the currently used integrating devices – it is possible to use white-beam radiation to conduct dynamic K-edge subtraction studies. This study demonstrates an approach to this imaging possibility using analysis of the spectral histogram in each image pixel. K-edge subtraction can be conducted more efficiently using a broad-spectrum X-ray source by processing groups of data either side of the K-edge. Using a simulated data model the possible quality of this new technique is explored under a number of assumed spectral resolutions. The effects on the final image of different methods of image subtraction and pre-processing are also explored.