Minimum detection time (MDT) for elemental EDXRF images

Abstract

When obtaining a chemical element image through energy dispersive X‐ray fluorescence (EDXRF) scanning of a specific sample, it is important to determine the minimum detection time (MDT) required per dot (pixel) and per element in order to identify the minority and the trace elements present in the sample. Starting from the statistical criteria of limit of detection, quantitative estimations can be made regarding the concentration of elements present in the samples, determining the MDT which fits to the limit of detection previously established. Given that with this technique it is possible to implement in vivo applications, in this work, a process was developed for the MDT that is capable of generating the minimum radiation exposure in imaging EDXRF. For this proposal, the MDT is determined for metals, such as Fe, Cu, and Pb, given their great biomedical interest, in a series of equivalent bone and soft tissue phantom samples. Consequently, a criteria for global scanning time per dot was established, hence providing an elemental XRF image according to the As Low As Reasonably Achievable principles, i.e. as low an exposure as reasonably possible for each sample type studied by this sort of devices, in order to obtain appropriate information for each field of application. Copyright © 2015 John Wiley & Sons, Ltd.