Preliminary evaluation of X-ray fluorescence imaging and ultra-high resolution CdTe PET: the progression toward broader spectrum multi-modality tools for small animal neuroscientific investigation

X-Ray Fluorescence Emission Tomography (XFET);Cadmium telluride (CdTe);Positron Emission Tomography (PET);Hybrid Pixel-Waveform;Energy Resolvable Photon Counting Detectors;Imaging;Transgenic Animals

Groll, Andrew Nicholas ; Meng ; Ling-Jian

关键词: X-Ray Fluorescence Emission Tomography (XFET);    Cadmium telluride (CdTe);    Positron Emission Tomography (PET);    Hybrid Pixel-Waveform;    Energy Resolvable Photon Counting Detectors;    Imaging;    Transgenic Animals;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/92655/GROLL-THESIS-2016.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The United States Food and Drug Administration (FDA) describes the development of medications to be a five step process which entails three direct steps located in the laboratory environment. These laboratory investigations include exploring the fundamental mechanisms governing the disease of interest as well as testing any drugs in the preclinical environment for a preliminary assessment of the potential impact of humans. The maximum preliminary assessment potential is in part constrained by the instruments available for exploring the small animals, generally mice, involved in the experiments. Nuclear instruments such X-ray, Positron Emission Tomography (PET), and Single Photon Emission Computed Tomography (SPECT) are often implemented due to their ability to identify either the anatomical or physical features of interest. In this thesis, two state of the art nuclear modalities, X-Ray Fluorescence Emission Tomography (XFET) and CdTe Hybrid Pixel-Waveform (HPWF) PET, are evaluated as potentially complementary experimental preclinical instruments due the their combined ability to reveal biological information through the utilization of a broader portion of the electromagnetic spectrum with discussion directly focused on neurological applications.The two independent experimental systems were evaluated for proof of concept in order establish the potential viability of imaging small transgenic animals. The first modality, a benchtop XFET system, used an incident monochromatic 17.4 keV beam with a slit mounted Andor Ikon-L Charge Coupled Device (CCD) with a featured pixelated element size of 13.5 μm x 13.5 μm. Samples for the XFET system were mounted on a 4-D stage capable of X-Y-Z translation with full rotation. Fluorescent emissions were measured from a triple tube capillary phantom composed of various chemical compositions in addition to a resin encased osmium stained zebrafish. Spectral results and imaging results are presented.The second modality was explored with an intent to better understand the maximum achievable spatial resolution. A dual HWPF detector coincidence system composed of CdTe energy resolvable photon counting (ERPC) detectors was implemented with a field programmable gate array (FPGA) modifiable readout sequence of an 8 application specific integrated circuit (ASIC) layout per detector. Each ASIC featured 64 x 32 pixelated elements of size 350 μm x 350 μm bump bonded to the under size of a 2 mm thick CdTe crystal with an area of 11 mm x 22 mm. The unique readout scheme of the HPWF detector design uses an external digitizer sampling at 200 Ms/s to save the cathode waveform and the anode waveform for each individual event for post processing. Experiments were performed using (A) a 10 μCi Na-22 source with a diameter of 250 μm, and (B) a set of 3 microcapillary tubes with sub 1 mm inner diameter.