Hybrid pixel-waveform semiconductor detectors: novel detector readout for semiconductor pet imaging of small animal neurodegenerative models

Developing nuclear detection instrumentation for biomedically selected tasks uniquely produces a dualistic intellectual challenge: the engineering of the instrument cannot occur without mastery knowledge of its governing principles while a lack of clear understanding of the application provides an uncertain instrument performance requirement. Therefore, this work lays the contextual importance of developing nuclear imaging instrumentation for application specific purposes by focused discussion on preclinical pathological dementia imaging. To this end, this work explores the potential use of small pixel hybrid pixel-waveform (HPWF) CdTe detectors for PET by experimentally evaluating common performance criteria such as timing resolution, energy resolution, and spatial resolution with efforts aimed at deconstructing the performance limitations as a PET detector module intended for imaging small animal neurodegenerative models. HPWF CdTe detectors utilize a simplified anode ASIC (Application Specific Integrated Circuit) to readout the anode pixels for providing the X-Y address of gamma interactions, and use digital waveform sampling circuitry to read the cathode waveform for deriving the energy, timing and (depth-of interaction) DOI. This offers several advantages over typical CdTe pixel detectors for PET, including a) an improved timing resolution over anode triggered pixelated detectors, b) an improved energy resolution since the cathode signal is immune to the charge sharing and charge loss due to small pixels, c) a simplified anode pixel readout circuitry for smaller pixels, and d) an excellent potential DOI resolution. Experimental work was performed in multiple iterations to include analysis of a phantom point source image, a simple back projected microfluidic phantom with 750 μm and 500 μm channels, and a mouse brain phantom demonstrating the spatial resolution breaking performance in application to mouse models while simultaneously comparing the improvement over the current 1-2 mm limit. The results show sub 1 millimeter spatial resolution is possible with HPWF detectors.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Nuclear, Plasma, Radiolgc Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2018

Author dc:creator

• Groll, Andrew Nicholas

Contributors dc:contributor

• Meng, Ling-Jian
• Uddin, Rizwan
• Dobrucki, Wawrzyniec
• Tai, Yuan-Chuan

• CdTe detectors
• PET
• Hybrid Pixel-Waveform
• Energy Resolvable Photon Counting Detectors

Statement dc:rights

• Copyright 2017 Andrew Groll

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/99177

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/99177