Speaker
Description
Low-dose imaging and small-animal positron-emission tomography (PET) require detectors with both high sensitivity and high spatial resolution. In this study, we investigate the performance of high-density scintillators, such as Bismuth Germanate (BGO) and LYSO:Ce, with multi-channel, low-noise, low-power, high-frequency (HF) readout electronics to enhance the Time-of-Flight (TOF) and Depth-of-Interaction (DOI) performance of pixelated detectors. High-frequency SiPM readout has demonstrated significant improvements in coincidence time resolution (CTR) by enabling the detection of ultrafast optical-photon production, such as Cherenkov emission in BGO and fast scintillation in LYSO:Ce.
Two DOI-encoding detector designs are compared in this work: a double-sided readout and a single-sided readout employing a light guide to achieve DOI encoding through light sharing of laterally depolished crystal matrices. The detector modules are read out using a custom sixteen-channel low-noise HF electronics board capable of setting a low leading-edge threshold for the detection of the earliest photons produced. In combination with metal-in-trench Broadcom SiPMs, which provide high photon detection efficiency in the relevant wavelength range, this approach enables improved timing and DOI resolution.
Experimental results demonstrate that matrices of 20 mm long LYSO:Ce crystals can achieve a DOI resolution of approximately 2 mm FWHM and a CTR of 130 ps FWHM using the light-sharing method. BGO crystals show a DOI resolution above 7 mm FWHM with the same method; however, this improves to 4.5 mm FWHM when a double-sided readout is employed, which also provides a CTR of 254 ps FWHM. The double-sided readout approach will be further investigated using LYSO matrices, where improved performance in terms of both timing and DOI resolution is expected.
| Track | FTMI |
|---|---|
| Presentation type | Oral |