Direct Charged-Particle Imaging System Using an Ultra-Thin Phosphor: Physical Characterization and Dynamic...

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Radiopharmaceutical Science

Background:

• In vivo imaging of beta rays is essential for microdosimetry and radiopharmaceutical development.
• A previously reported system for in vivo imaging of high-energy electron emissions in small animals required further characterization.

Purpose of the Study:

• To thoroughly characterize the performance of a newly developed system for in vivo beta ray imaging.
• To evaluate the system's sensitivity, detectability, spatial resolution, and linearity.
• To demonstrate the system's capability in dynamically imaging radiotracer uptake in vivo.

Main Methods:

• Performance characterization including sensitivity, detectability, spatial resolution, and linearity measurements.
• Demonstration of detection for beta rays, conversion electrons, and positrons.
• Application to dynamic imaging of (18)F-Fluorodeoxyglucose (FDG) uptake in mouse xenograft tumors.

Main Results:

• The system's performance metrics (sensitivity, detectability, resolution, linearity) were thoroughly measured.
• The system demonstrated the ability to detect various high-energy electrons, including beta rays, conversion electrons, and positrons.
• Dynamic imaging revealed heterogeneous (18)F-FDG uptake distributions in millimeter-sized xenograft tumors in mice.

Conclusions:

• The characterized system provides a valuable tool for in vivo beta ray imaging.
• The system's ability to detect diverse electron emissions and image radiotracer uptake is confirmed.
• Observed heterogeneity in FDG uptake highlights the system's potential for preclinical cancer research.