A 1.5 mm BGO PET detector with DOI measurement

Area of Science:

• Medical Imaging
• Nuclear Instrumentation
• Materials Science

Background:

• Small-animal PET systems require high sensitivity, spatial resolution, and signal-to-noise ratio (SNR).
• Extracting depth-of-interaction (DOI) information is crucial for improving PET performance.
• Bismuth germanate (BGO) crystals have limitations in light yield, complicating DOI measurement.

Purpose of the Study:

• To develop and validate a DOI detector for small-animal PET systems.
• To overcome challenges in DOI extraction with BGO crystals.
• To provide a cost-effective DOI solution for high-sensitivity PET.

Main Methods:

• A 10 × 8 BGO crystal array was coupled to a MPPC array using a light-sharing window (LSW).
• The detector configuration aimed to enhance DOI measurement despite BGO's low light yield.
• A rapid calibration method involving vertical line source irradiation and histogram matching was employed.

Main Results:

• The detector achieved an intrinsic DOI resolution of 4.4 mm (FWHM) and a mean absolute error (MAE) of 2.2 mm.
• An energy resolution of 17.4% was obtained at 511 keV.
• The rapid calibration method yielded a DOI resolution of 4.9 mm (FWHM) in a single measurement.

Conclusions:

• The light-sharing window (LSW) method is feasible for BGO-based DOI detectors.
• This approach offers a cost-effective solution for high-sensitivity small-animal PET imaging.
• The developed DOI detector meets the demands for improved PET system performance.