A Study of Coincidence Line Spread Function (CLSF) Estimation for Small Scintillators Using Quadrant Sharing Technique

Mehmet Aykac; Hongdi Li; Jorge Uribe; Yu Wang; Hossain Baghaei; Yaqiang Liu; Tao Xing; Wai Hoi Wong

doi:10.1109/TNS.2003.817965

A Study of Coincidence Line Spread Function (CLSF) Estimation for Small Scintillators Using Quadrant Sharing Technique

Mehmet Aykac, Hongdi Li, Jorge Uribe, Yu Wang, Hossain Baghaei, Yaqiang Liu, Tao Xing, Wai Hoi Wong

Cancer Systems Imaging

Research output: Contribution to journal › Article › peer-review

3 Scopus citations

Abstract

Inter-crystal scatter and scintillation light spread are the primary factors for mispositioning of coincidence events in positron emission tomography (PET) for light sharing detectors. The probability of Compton scatter of a 511 keV photon within the crystal is more than 50% of the interactions. Inter-crystal scatter has been studied before and it was concluded that the coincidence line spread function (CLSF) was not significantly affected. Unlike one-to-one scintillator-photomultiplier tube (PMT) coupled (discrete) detectors, detector blocks utilizing the light sharing technique have additional degradation of their spatial resolution due to shared scintillation photons within the block. This study focuses on an estimation of CLSF for 7 × 7 BGO (bismuth germanate) detector blocks by comparing the simulation results for discrete and light shared detectors. The simulation model included inter-crystal scatter but the effect of scintillation light spread is the primary emphasis of our investigation. Based on experimental measurements, deterministic position profiles that calculate a spread (uncertainty) in positioning due to light sharing between neighboring crystals, were estimated from simple photoelectron statistics. The resultswere embedded in the Monte Carlo simulation to estimate the CLSF more accurately. Two 7 × 7 BGO detector blocks (2.68 mm × 2.68 mm × 18 mm) with different surface treatments coupled to 4 PMTs were used to estimate the positioning spread values. For discrete detectors, the FWHM values of CLSF for 7 × 7 BGO block with crystal dimensions of 2.68 mm × 2.68 mm × 18 mm were found to be approximately 1.47 mm for discrete detectors and 1.51 mm for light shared detectors. The intrinsic spatial resolutions of 7 × 7 light shared BGO block with crystal dimensions of 2.68 mm × 2. 68 mm × 18 mm for 20 cm, 40 cm and 80 cm detector ring diameters were estimated as 1.57 mm, 1.75 mm and 2.30 mm, respectively.

Original language	English (US)
Pages (from-to)	1331-1338
Number of pages	8
Journal	IEEE Transactions on Nuclear Science
Volume	50
Issue number	5 II
DOIs	https://doi.org/10.1109/TNS.2003.817965
State	Published - Oct 2003

Keywords

Coincidence line
Monte Carlo methods
Positron emission tomography

ASJC Scopus subject areas

Nuclear and High Energy Physics
Nuclear Energy and Engineering
Electrical and Electronic Engineering

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10.1109/TNS.2003.817965

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@article{ad23a879f2f64ac096313d72ee645c7d,

title = "A Study of Coincidence Line Spread Function (CLSF) Estimation for Small Scintillators Using Quadrant Sharing Technique",

abstract = "Inter-crystal scatter and scintillation light spread are the primary factors for mispositioning of coincidence events in positron emission tomography (PET) for light sharing detectors. The probability of Compton scatter of a 511 keV photon within the crystal is more than 50% of the interactions. Inter-crystal scatter has been studied before and it was concluded that the coincidence line spread function (CLSF) was not significantly affected. Unlike one-to-one scintillator-photomultiplier tube (PMT) coupled (discrete) detectors, detector blocks utilizing the light sharing technique have additional degradation of their spatial resolution due to shared scintillation photons within the block. This study focuses on an estimation of CLSF for 7 × 7 BGO (bismuth germanate) detector blocks by comparing the simulation results for discrete and light shared detectors. The simulation model included inter-crystal scatter but the effect of scintillation light spread is the primary emphasis of our investigation. Based on experimental measurements, deterministic position profiles that calculate a spread (uncertainty) in positioning due to light sharing between neighboring crystals, were estimated from simple photoelectron statistics. The resultswere embedded in the Monte Carlo simulation to estimate the CLSF more accurately. Two 7 × 7 BGO detector blocks (2.68 mm × 2.68 mm × 18 mm) with different surface treatments coupled to 4 PMTs were used to estimate the positioning spread values. For discrete detectors, the FWHM values of CLSF for 7 × 7 BGO block with crystal dimensions of 2.68 mm × 2.68 mm × 18 mm were found to be approximately 1.47 mm for discrete detectors and 1.51 mm for light shared detectors. The intrinsic spatial resolutions of 7 × 7 light shared BGO block with crystal dimensions of 2.68 mm × 2. 68 mm × 18 mm for 20 cm, 40 cm and 80 cm detector ring diameters were estimated as 1.57 mm, 1.75 mm and 2.30 mm, respectively.",

keywords = "Coincidence line, Monte Carlo methods, Positron emission tomography",

author = "Mehmet Aykac and Hongdi Li and Jorge Uribe and Yu Wang and Hossain Baghaei and Yaqiang Liu and Tao Xing and Wong, {Wai Hoi}",

note = "Funding Information: Manuscript received January 28, 2002; revised July 1, 2003. This work was supported by NIH Grants RO1 CA76246, RO1 CA61880, and RO1 CA58980, the J.S. Dunn Research Foundation, and the Cobb Endowment for Cancer Research.",

year = "2003",

month = oct,

doi = "10.1109/TNS.2003.817965",

language = "English (US)",

volume = "50",

pages = "1331--1338",

journal = "IEEE Transactions on Nuclear Science",

issn = "0018-9499",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

number = "5 II",

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T1 - A Study of Coincidence Line Spread Function (CLSF) Estimation for Small Scintillators Using Quadrant Sharing Technique

AU - Aykac, Mehmet

AU - Li, Hongdi

AU - Uribe, Jorge

AU - Wang, Yu

AU - Baghaei, Hossain

AU - Liu, Yaqiang

AU - Xing, Tao

AU - Wong, Wai Hoi

N1 - Funding Information: Manuscript received January 28, 2002; revised July 1, 2003. This work was supported by NIH Grants RO1 CA76246, RO1 CA61880, and RO1 CA58980, the J.S. Dunn Research Foundation, and the Cobb Endowment for Cancer Research.

PY - 2003/10

Y1 - 2003/10

N2 - Inter-crystal scatter and scintillation light spread are the primary factors for mispositioning of coincidence events in positron emission tomography (PET) for light sharing detectors. The probability of Compton scatter of a 511 keV photon within the crystal is more than 50% of the interactions. Inter-crystal scatter has been studied before and it was concluded that the coincidence line spread function (CLSF) was not significantly affected. Unlike one-to-one scintillator-photomultiplier tube (PMT) coupled (discrete) detectors, detector blocks utilizing the light sharing technique have additional degradation of their spatial resolution due to shared scintillation photons within the block. This study focuses on an estimation of CLSF for 7 × 7 BGO (bismuth germanate) detector blocks by comparing the simulation results for discrete and light shared detectors. The simulation model included inter-crystal scatter but the effect of scintillation light spread is the primary emphasis of our investigation. Based on experimental measurements, deterministic position profiles that calculate a spread (uncertainty) in positioning due to light sharing between neighboring crystals, were estimated from simple photoelectron statistics. The resultswere embedded in the Monte Carlo simulation to estimate the CLSF more accurately. Two 7 × 7 BGO detector blocks (2.68 mm × 2.68 mm × 18 mm) with different surface treatments coupled to 4 PMTs were used to estimate the positioning spread values. For discrete detectors, the FWHM values of CLSF for 7 × 7 BGO block with crystal dimensions of 2.68 mm × 2.68 mm × 18 mm were found to be approximately 1.47 mm for discrete detectors and 1.51 mm for light shared detectors. The intrinsic spatial resolutions of 7 × 7 light shared BGO block with crystal dimensions of 2.68 mm × 2. 68 mm × 18 mm for 20 cm, 40 cm and 80 cm detector ring diameters were estimated as 1.57 mm, 1.75 mm and 2.30 mm, respectively.

AB - Inter-crystal scatter and scintillation light spread are the primary factors for mispositioning of coincidence events in positron emission tomography (PET) for light sharing detectors. The probability of Compton scatter of a 511 keV photon within the crystal is more than 50% of the interactions. Inter-crystal scatter has been studied before and it was concluded that the coincidence line spread function (CLSF) was not significantly affected. Unlike one-to-one scintillator-photomultiplier tube (PMT) coupled (discrete) detectors, detector blocks utilizing the light sharing technique have additional degradation of their spatial resolution due to shared scintillation photons within the block. This study focuses on an estimation of CLSF for 7 × 7 BGO (bismuth germanate) detector blocks by comparing the simulation results for discrete and light shared detectors. The simulation model included inter-crystal scatter but the effect of scintillation light spread is the primary emphasis of our investigation. Based on experimental measurements, deterministic position profiles that calculate a spread (uncertainty) in positioning due to light sharing between neighboring crystals, were estimated from simple photoelectron statistics. The resultswere embedded in the Monte Carlo simulation to estimate the CLSF more accurately. Two 7 × 7 BGO detector blocks (2.68 mm × 2.68 mm × 18 mm) with different surface treatments coupled to 4 PMTs were used to estimate the positioning spread values. For discrete detectors, the FWHM values of CLSF for 7 × 7 BGO block with crystal dimensions of 2.68 mm × 2.68 mm × 18 mm were found to be approximately 1.47 mm for discrete detectors and 1.51 mm for light shared detectors. The intrinsic spatial resolutions of 7 × 7 light shared BGO block with crystal dimensions of 2.68 mm × 2. 68 mm × 18 mm for 20 cm, 40 cm and 80 cm detector ring diameters were estimated as 1.57 mm, 1.75 mm and 2.30 mm, respectively.

KW - Coincidence line

KW - Monte Carlo methods

KW - Positron emission tomography

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ER -

A Study of Coincidence Line Spread Function (CLSF) Estimation for Small Scintillators Using Quadrant Sharing Technique

Abstract

Keywords

ASJC Scopus subject areas

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