Multiple-hit parameter estimation in monolithic detectors

William C J Hunter, Harrison H Barrett, Robert S. Miyaoka, Tom K. Lewellen

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We examine a maximum-a-priori (MAP) method for estimating the primary interaction position of gamma rays with multiple-interaction sites (hits) in a monolithic detector. In assessing the performance of a multiple-hit estimator over that of a conventional one-hit estimator, we consider a few different detector and readout configurations of a 50-mm-wide square LSO block. For this study, we use simulated data from SCOUT, a Monte-Carlo tool for photon tracking and modeling scintillation-camera output. With this tool, we determine estimate bias and variance for a multiple-hit estimator and compare these with similar metrics for a conventional ML estimator, which assumes full energy deposition in one hit. We also examine the effect of event filtering on these metrics; for this purpose, we use a likelihood threshold to reject signals that are not likely to have been produced under the assumed likelihood model. Depending on detector design, we observe a 1-12% improvement of intrinsic resolution for a 1-or-2-hit estimator as compared with a 1-hit estimator. We also observe improved differentiation of photopeak events using a 1-or-2-hit estimator as compared with the 1-hit estimator; more than 6% of photopeak events that were rejected by likelihood filtering for the 1-hit estimator were accurately identified as photopeak events and positioned without loss of resolution by a 1-or-2-hit estimator.

Original languageEnglish (US)
Title of host publicationIEEE Nuclear Science Symposium Conference Record
Pages2224-2229
Number of pages6
DOIs
StatePublished - 2012
Event2011 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2011 - Valencia, Spain
Duration: Oct 23 2011Oct 29 2011

Other

Other2011 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2011
CountrySpain
CityValencia
Period10/23/1110/29/11

Fingerprint

Gamma Cameras
Gamma Rays
Photons
estimators
detectors
photopeak
scintillation
readout
estimating
cameras
interactions
gamma rays

ASJC Scopus subject areas

  • Radiation
  • Nuclear and High Energy Physics
  • Radiology Nuclear Medicine and imaging

Cite this

Hunter, W. C. J., Barrett, H. H., Miyaoka, R. S., & Lewellen, T. K. (2012). Multiple-hit parameter estimation in monolithic detectors. In IEEE Nuclear Science Symposium Conference Record (pp. 2224-2229). [6154454] https://doi.org/10.1109/NSSMIC.2011.6154454

Multiple-hit parameter estimation in monolithic detectors. / Hunter, William C J; Barrett, Harrison H; Miyaoka, Robert S.; Lewellen, Tom K.

IEEE Nuclear Science Symposium Conference Record. 2012. p. 2224-2229 6154454.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Hunter, WCJ, Barrett, HH, Miyaoka, RS & Lewellen, TK 2012, Multiple-hit parameter estimation in monolithic detectors. in IEEE Nuclear Science Symposium Conference Record., 6154454, pp. 2224-2229, 2011 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2011, Valencia, Spain, 10/23/11. https://doi.org/10.1109/NSSMIC.2011.6154454
Hunter WCJ, Barrett HH, Miyaoka RS, Lewellen TK. Multiple-hit parameter estimation in monolithic detectors. In IEEE Nuclear Science Symposium Conference Record. 2012. p. 2224-2229. 6154454 https://doi.org/10.1109/NSSMIC.2011.6154454
Hunter, William C J ; Barrett, Harrison H ; Miyaoka, Robert S. ; Lewellen, Tom K. / Multiple-hit parameter estimation in monolithic detectors. IEEE Nuclear Science Symposium Conference Record. 2012. pp. 2224-2229
@inproceedings{07d0ee82c56e4c2da4cda61d91569b59,
title = "Multiple-hit parameter estimation in monolithic detectors",
abstract = "We examine a maximum-a-priori (MAP) method for estimating the primary interaction position of gamma rays with multiple-interaction sites (hits) in a monolithic detector. In assessing the performance of a multiple-hit estimator over that of a conventional one-hit estimator, we consider a few different detector and readout configurations of a 50-mm-wide square LSO block. For this study, we use simulated data from SCOUT, a Monte-Carlo tool for photon tracking and modeling scintillation-camera output. With this tool, we determine estimate bias and variance for a multiple-hit estimator and compare these with similar metrics for a conventional ML estimator, which assumes full energy deposition in one hit. We also examine the effect of event filtering on these metrics; for this purpose, we use a likelihood threshold to reject signals that are not likely to have been produced under the assumed likelihood model. Depending on detector design, we observe a 1-12{\%} improvement of intrinsic resolution for a 1-or-2-hit estimator as compared with a 1-hit estimator. We also observe improved differentiation of photopeak events using a 1-or-2-hit estimator as compared with the 1-hit estimator; more than 6{\%} of photopeak events that were rejected by likelihood filtering for the 1-hit estimator were accurately identified as photopeak events and positioned without loss of resolution by a 1-or-2-hit estimator.",
author = "Hunter, {William C J} and Barrett, {Harrison H} and Miyaoka, {Robert S.} and Lewellen, {Tom K.}",
year = "2012",
doi = "10.1109/NSSMIC.2011.6154454",
language = "English (US)",
isbn = "9781467301183",
pages = "2224--2229",
booktitle = "IEEE Nuclear Science Symposium Conference Record",

}

TY - GEN

T1 - Multiple-hit parameter estimation in monolithic detectors

AU - Hunter, William C J

AU - Barrett, Harrison H

AU - Miyaoka, Robert S.

AU - Lewellen, Tom K.

PY - 2012

Y1 - 2012

N2 - We examine a maximum-a-priori (MAP) method for estimating the primary interaction position of gamma rays with multiple-interaction sites (hits) in a monolithic detector. In assessing the performance of a multiple-hit estimator over that of a conventional one-hit estimator, we consider a few different detector and readout configurations of a 50-mm-wide square LSO block. For this study, we use simulated data from SCOUT, a Monte-Carlo tool for photon tracking and modeling scintillation-camera output. With this tool, we determine estimate bias and variance for a multiple-hit estimator and compare these with similar metrics for a conventional ML estimator, which assumes full energy deposition in one hit. We also examine the effect of event filtering on these metrics; for this purpose, we use a likelihood threshold to reject signals that are not likely to have been produced under the assumed likelihood model. Depending on detector design, we observe a 1-12% improvement of intrinsic resolution for a 1-or-2-hit estimator as compared with a 1-hit estimator. We also observe improved differentiation of photopeak events using a 1-or-2-hit estimator as compared with the 1-hit estimator; more than 6% of photopeak events that were rejected by likelihood filtering for the 1-hit estimator were accurately identified as photopeak events and positioned without loss of resolution by a 1-or-2-hit estimator.

AB - We examine a maximum-a-priori (MAP) method for estimating the primary interaction position of gamma rays with multiple-interaction sites (hits) in a monolithic detector. In assessing the performance of a multiple-hit estimator over that of a conventional one-hit estimator, we consider a few different detector and readout configurations of a 50-mm-wide square LSO block. For this study, we use simulated data from SCOUT, a Monte-Carlo tool for photon tracking and modeling scintillation-camera output. With this tool, we determine estimate bias and variance for a multiple-hit estimator and compare these with similar metrics for a conventional ML estimator, which assumes full energy deposition in one hit. We also examine the effect of event filtering on these metrics; for this purpose, we use a likelihood threshold to reject signals that are not likely to have been produced under the assumed likelihood model. Depending on detector design, we observe a 1-12% improvement of intrinsic resolution for a 1-or-2-hit estimator as compared with a 1-hit estimator. We also observe improved differentiation of photopeak events using a 1-or-2-hit estimator as compared with the 1-hit estimator; more than 6% of photopeak events that were rejected by likelihood filtering for the 1-hit estimator were accurately identified as photopeak events and positioned without loss of resolution by a 1-or-2-hit estimator.

UR - http://www.scopus.com/inward/record.url?scp=84858681435&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84858681435&partnerID=8YFLogxK

U2 - 10.1109/NSSMIC.2011.6154454

DO - 10.1109/NSSMIC.2011.6154454

M3 - Conference contribution

AN - SCOPUS:84858681435

SN - 9781467301183

SP - 2224

EP - 2229

BT - IEEE Nuclear Science Symposium Conference Record

ER -