Cherenkov luminescence imaging in transparent media and the imaging of thin or shallow sources

Abstract

Abstract. In this work, we demonstrated the possibility of high spatial resolution Cherenkov luminescence imaging (CLI) for objects in transparent media. We also demonstrated the possibility of the CLI of thin opaque objects using optical transducers. Results demonstrate that submillimeter resolution CLI is achievable for beta-emitting radionuclides, including 76 Br that emits positrons of very high energy. The imaging of beta-emitters through scintillation detectors exhibits lower resolution when compared to CLI of the same sources. The application of optical transducers for the CLI was demonstrated using plants labeled with 11 CO 2 and phantoms containing beta-emitters.

Cherenkov luminescence imaging of shallow sources in semitransparent media

“…As it was shown in Ref. 13, distribution of the CR emitted from the tape reproduces approximately the activity distribution on the acrylic plate. The CR profiles of the "0" layer phantoms are presented in Fig.…”

“…Thus, statistically, the beta particle scattering can be ignored as it was demonstrated in our previous work. 13 Also in this work, a straight trajectory approximation demonstrates reasonable results for the analytical calculations of the point spread functions for the CR sources in transparent media.…”

“…We combine both MC simulation and experimentally measured data to characterize CLI with respect to the beta particle end-point energy. This is an extension of our previous work 13 where we studied the CLI of beta sources in transparent media. This work expands previous consideration to the semitransparent media, particular, to the characteristics of CLI when the depths of the radioactive sources are comparable to the mean beta particle CR range in the media.…”

“…2,3 Recently, several groups have demonstrated and characterized the use of CLI to measure the distribution of beta-emitting radionuclides (both positron and electron) in small animals by optical imaging systems. [4][5][6][7][8][9] These studies demonstrated that a wide variety of beta-emitting radionuclides (including 18 F, 13 N, 64 Cu, 89 Zr, 90 Y, 124 I, 131 I, and 177 Lu) can be used for CLI. In the studies reported by Mitchell et al and Gill et al, 7,8 the light output from the CR in transparent media was estimated using GEANT4-based Monte Carlo (MC) simulation.…”

“…The reason that we are particularly interested in the behavior of CLI in this shallow depth is because the directional nature of CR in transparent media causes "flashlight effect." 13 That is, if there is no light scattering in a media, the only CR photons that can be detected by the camera are the photons emitted by the particles moving toward camera (within range of angles determined by the CR cone angle and camera's aperture). Although the scattering of the light photons in semitransparent media should washout this effect, CR photons emitted by the particles moving toward the camera near the surface of the media will be less subjected to the absorption and scattering by the tissue.…”