[22p-A102-1~17] 2.4 Medical application

▲ [22p-A102-12] Double Photon Coincidence Imaging with Parallel and Slit Collimators in vivo

〇(D)Linlin YAN¹, Mizuki Uenomachi², Taisei Ueki¹, Donghwan Kim¹, Kenji Shimazoe¹, Hiroyuki Takahashi¹ (1.The Univ. of Tokyo, 2.The Univ. of Kotyo)

Keywords:Double-Photon Emission Computed Tomography, Coincidence detection

In medical imaging, SPECT is widely used modality which is using single photon detection from radioisotope. However further development of increasing the contrast in the image is still under investigation. Recently, we proposed a novel method (Double Photon Emission CT) using a coincidence detection of two cascade gamma-rays from the radiotracer. The radiotracer used in this imaging method include nuclides such as ¹¹¹In that emit several gamma rays at the same time. Coincidence detection of two cascaded gamma rays from ¹¹¹In was used in this study. With a short delay of approximately 85 ns, ¹¹¹In, a well-known and widely used SPECT tracer, emits two cascade photons of 171 keV and 245 keV. In comparison with single photon detection, the coincidence detection of two gamma-rays theoretically identifies the position in a single point and dramatically improves the signal-to-noise ratio. In this study, we demonstrated the double photon coincidence imaging with parallel and slit collimators in tumor-bearing mouse and succeeded to visualize ¹¹¹In-antibody accumulation.