Double photon emission coincidence imaging with GAGG-SiPM Compton camera

Compton imaging is a promising gamma-ray imaging method based on the Compton scattering kinematics due to high Compton scattering probability for sub-MeV to MeV gamma-rays. A conventional Compton camera has a disadvantage of low signal-to-background ratio (SBR), which is caused by drawing of multiple Compton cones. A method to solve this fundamental problem is the double-photon emission computed tomography (DPECT), which uses the coincidence detection for cascade gamma-rays and significantly increases the SBR using intersections of two Compton cones. In this study, we demonstrated the DPECT method by using 134Cs radio isotope, which is one of important radioisotopes for the imaging of fuel debris, with two Ce:Gd(Al,Ga)O12 (GAGG) scintillator Compton cameras

Development of a transparent single-grid-type MSGC based on LCD technology

We are developing a multi-grid-type MSGC based on the liquid crystal display (LCD) technology, which enables a large area and fine structure. Single-grid-type MSGC using transparent electrodes has been fabricated and successfully operated in several different gas mixtures. The use of LCD technology allows us to integrate some simple electronics using thin film transistors. Such an integrated device is our next target. The successful operation of Single-grid-type MSGC is the very important first step for us

Simultaneous measurements of single gamma ray of 131I and annihilation radiation of 18F with Compton PET hybrid camera

In internal 131I therapy for thyroid cancer, a decision to continue treatment is made by comparing 131I scintigraphy and [18F]FDG-PET. However, with current SPECT and PET systems, simultaneous imaging of diagnostic PET nuclides and therapeutic 131I nuclides has not been achieved so far. Therefore, we demonstrated that the recently developed Compton PET hybrid camera with Ce:Gd3(Al,Ga)5O12 (GAGG)- Silicon Photomultiplier(SiPM) scintillation detectors can be used to simultaneously image 131I Compton image and 18F PET image

Development of a transparent single-grid-type MSGC based on LCD technology

We are developing a multi-grid-type MSGC based on the liquid crystal display (LCD) technology, which enables a large area and fine structure. Single-grid-type MSGC using transparent electrodes has been fabricated and successfully operated in several different gas mixtures. The use of LCD technology allows us to integrate some simple electronics using thin film transistors. Such an integrated device is our next target. The successful operation of Single-grid-type MSGC is the very important first step for us

Simultaneous in vivo imaging with PET and SPECT tracers using a Compton-PET hybrid camera

Positron-emission tomography (PET) and single-photon-emission computed tomography (SPECT) are well-established nuclear-medicine imaging methods used in modern medical diagnoses. Combining PET with 18F-fuorodeoxyglucose (FDG) and SPECT with an 111In-labelled ligand provides clinicians with information about the aggressiveness and specifc types of tumors. However, it is difcult to integrate a SPECT system with a PET system because SPECT requires a collimator. Herein, we describe a novel method that provides simultaneous imaging with PET and SPECT nuclides by combining PET imaging and Compton imaging. The latter is an imaging method that utilizes Compton scattering to visualize gamma rays over a wide range of energies without requiring a collimator. Using Compton imaging with SPECT nuclides, instead of the conventional SPECT imaging method, enables PET imaging and Compton imaging to be performed with one system. In this research, we havedemonstrated simultaneous in vivo imaging of a tumor-bearing mouse injected with 18F-FDG and an 111In-antibody by using a prototype Compton-PET hybrid camera. We have succeeded in visualizing accumulations of 18F-FDG and 111In-antibody by performing PET imaging and Compton imaging simultaneously. As simultaneous imaging utilizes the same coordinate axes, it is expected to improve the accuracy of diagnoses