[2H01-08] Imaging Detectors

[2H06] Quantum sensing of pH around local environment using cascade photon angular correlation change and application to nuclear medicine imaging

*Fumiki Sensui¹, Mizuki Uenomachi², Kenji Shimazoe^1,5, Hiroyuki Takahashi¹, Zhihong Zhong¹, Hideki Tomita^3,5, Kei Kamada⁴ (1. The University of Tokyo, 2. Institute of Physical and Chemical Research, 3. Nagoya University, 4. Tohoku University, 5. JST PRESTO)

Keywords:Nuclear Medicine, Angular Correlation, Double Photon Nuclide, Quantum Sensing

Our group has been developing DPECT (Double Photon Emission CT) to improve the accuracy of nuclear medicine diagnosis using cascade nuclides that emit multiple gamma rays simultaneously. There is an angular correlation between two gamma rays emitted from a two-photon nuclide, which depends on the local environment around the nuclide. In this study, we propose and investigate a new sensing and imaging method to detect the pH and chemical state around radionuclides by measuring the angular correlation change of the cascade nuclides. In order to verify the principle, we measured the angular correlation change of ¹¹¹InCl₃ aqueous solution in different pH environments, and observed a 5% increase in the emission around the 180 degree direction and a 5% decrease in the emission around the 90 degree direction in the environments above pH 3. By applying the measured degree of angular correlation change to SPECT technology, we succeeded in simultaneously performing positional decomposition by imaging and pH decomposition by angular correlation.