Fig. 4.

DE CT imaging enables quantitative, 3D mapping of extrinsic contrast agents (iodine, red; gold, green) and soft tissues (gray) present in the subject (coronal maximum intensity projections shown through a live mouse). However, because DE CT with EIDs provide only two independent measurements with limited sensitivity, it is difficult to separate certain intrinsic materials, such as bones (see ribs, yellow arrow), from gold nanoparticles accumulated in the spleen (blue arrow). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)