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Mohan Li

C★STAR Program 2018

Areas of Research

Development of an Organ Dedicated PET System

PI: Shiva AbbaszadehBretty Yockey, MD – Carle Physician Mentor

Whole-body (WB) positron emission tomography (PET) has beed widely used for early diagnosis, recurrence prediction and radiotherapy of cancers in di↵erent regions. However, the poor counting efficiency, inadequate spatial and contrast resolutions, relatively high cost and long scan times of WB PET obstructs its clinical performance. For example, the spatial resolution of WB PET is typically 4 to 6 mm, which causes the detection of lesions less than 10 mm in diameter less accurately. In breast cancer, however, only about 58% of primary tumors whose diameters are larger than 10 mm.

We have begun to develop a detector module for the proposed system. The scintillator is a 6 ⇥ 6 LYSO array (EPIC Crystal, China) and the pixel size is 1 ⇥ 1 ⇥ 20 mm3. The four lateral surfaces of each pixel are ground in W14 to reduce reflection and improve DOI resolution, and the two end surfaces are polished to improve the light collection efficiency. The reflective material is Toray E60 (Toray Industries, Japan). A 2-mm optical light guide H-K9L (Foctek Photonics, Japan) is used to share lights to a 2 ⇥ 2 SiPM array (S13361-3050AE-08, Hamamatsu Photonics, Japan) for the sake of crystal identification. DOI resolution was implemented by dual-ended readout. The readout electronics is based on TOFPET2 ASIC (PETsys Electronics, Portugal). The designed detector module has a compact geometry and is easy to scale up to build the whole proposed system.

Through this project, we will go through the complete process of a system design including performance simulation, detector design and system assembly. We will also build a deeper understanding about the influence of detector performances on the system performances and balance trade-off considerations. Our ultimate goal is not only to build a high performance organ dedicated PET system but also to make it to be used in hospitals and genuinely help doctors and patients.