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Convex Optimization of Coincidence Time Resolution for a High-Resolution PET System

文献技术官添加于 2011-6-5 20:27 | 2950 次阅读 | 0 个评论

作者
Reynolds PD, Olcott PD, Pratx G, Lau FWY, Levin CS
摘要
We are developing a dual panel breast-dedicated PET system using LSO scintillators coupled to position sensitive avalanche photodiodes (PSAPD). The charge output is amplified and read using NOVA RENA-3 ASICs. This paper shows that the coincidence timing resolution of the RENA-3 ASIC can be improved using certain list-mode calibrations. We treat the calibration problem as a convex optimization problem and use the RENA-3s analog-based timing system to correct the measured data for time dispersion effects from correlated noise, PSAPD signal delays and varying signal amplitudes. The direct solution to the optimization problem involves a matrix inversion that grows order (n3) with the number of parameters. An iterative method using single-coordinate descent to approximate the inversion grows order (n). The inversion does not need to run to convergence, since any gains at high iteration number will be low compared to noise amplification. The system calibration method is demonstrated with measured pulser data as well as with two LSO-PSAPD detectors in electronic coincidence. After applying the algorithm, the 511keV photopeak paired coincidence time resolution from the LSO-PSAPD detectors under study improved by 57%, from the raw value of 16.30.07 ns FWHM to 6.920.02 ns FWHM (11.520.05 ns to 4.890.02 ns for unpaired photons).
详细资料
- 文献种类: Journal Article
- 期刊名称: IEEE Transactions on Medical Imaging
- 期刊缩写: IEEE Trans. Med. Imaging
- 期卷页: 2011年第30卷第2期 391-400页
- ISBN: 0278-0062
学科领域信息系统 » 计算机科学
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附件
Convex Optimization of Coincidence Time Resolution for a High-Resolution PET System