Abstract: This presentation will discuss our recent research and developmental efforts toward broadband X-ray fluorescence emission tomography (XFET) techniques for simultaneous imaging of multiple trace metals, such as Br, La, Gd, Hf, Au, Lu, Pt, in small lab animals. One of our emphases is to use low-powered laboratory X-ray sources to facilitate the XFET studies, so as to make it widely accessible to the medical imaging community and biology labs, and to minimize the radiation dose to the lab animal for potential in vivo studies. In order to achieve an adequate signal-to-noise ratio (SNR), we have been developing and optimizing a series of enabling techniques. These include small-pixel CdTe imaging spectrometers, low-noise readout electronics, machine learning (ML) techniques for compensating for the charge-sharing effects, 1-D or 2-D inverted compound-eye (ICE) camera designs for optimizing the sensitivity, as well as the various system geometry for reducing the influence of scattered X-ray noise. These technological components have been integrated into a bench-top XFET system that consists of a full ring of 24 ICE cameras surrounding the object. Our preliminary results have demonstrated a sensitivity of sub-25 µg/ml for Gd in mouse-sized objects and a clear potential to achieve a single µg/ml level with an optimized system design and the use of a synchrotron X-ray beam.

In this talk, we will present details of these developmental steps, the initial performance assessment of XFET system, as well as feasibility studies of using the XFET system to image therapeutic agents for cancer and micro-scintillation crystals for remote X-ray induced optogenetics effects in mice. More importantly, we would like to use this opportunity to explore collaborative research from both X-ray detection and X-ray source perspectives to bring the sensitivity of XFET down to molecular-imaging-relevant levels (such as sub-µg/ml) for imaging live animals and to find truly meaningful applications of the XFET technique.

Bio: Ling-Jian Meng is currently a Professor at the University of Illinois at Urbana-Champaign (UIUC) in the Department of Nuclear, Plasma, and Radiological Engineering and the Department of Bioengineering, and an affiliated member of the Beckman Institute of Advanced Science and Technology. Meng is also a Visiting Associate Professor at the Massachusetts General Hospital (MGH), an Associate Editor for leading research journals, such as the IEEE Transaction on Medical Imaging (TMI) and Medical Physics, and a charter member of the NIH Imaging Technology Development (ITD) study session.