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Accuracy of a whole-body single-photon emission computed tomography with a thallium-bromide detector : Verification via Monte Carlo simulations

Ito, Toshimune ; Hitomi, Keitaro ; Ljungberg, Michael LU orcid ; Kawasaki, Sousei ; Katayama, Yuka ; Kato, Akane ; Tsuchikame, Hirotatsu ; Suzuki, Kentaro ; Miyazaki, Kyosuke and Mogi, Ritsushi (2025) In Medical Physics 52(6). p.4079-4095
Abstract

Background: Single-photon emission computed tomography (SPECT) devices equipped with cadmium–zinc–telluride (CZT) detectors achieve high contrast resolution because of their enhanced energy resolution. Recently, thallium bromide (TlBr) has gained attention as a detector material because of its high atomic number and density. Purpose: This study evaluated the clinical applicability of a SPECT system equipped with TlBr detectors using Monte Carlo simulations, focusing on 99mTc and 177Lu imaging. Methods: This study used the Simulation of Imaging Nuclear Detectors Monte Carlo program to compare the imaging characteristics between a whole-body SPECT system equipped with TlBr (T-SPECT) and a system equipped with CZT detectors (C-SPECT). The... (More)

Background: Single-photon emission computed tomography (SPECT) devices equipped with cadmium–zinc–telluride (CZT) detectors achieve high contrast resolution because of their enhanced energy resolution. Recently, thallium bromide (TlBr) has gained attention as a detector material because of its high atomic number and density. Purpose: This study evaluated the clinical applicability of a SPECT system equipped with TlBr detectors using Monte Carlo simulations, focusing on 99mTc and 177Lu imaging. Methods: This study used the Simulation of Imaging Nuclear Detectors Monte Carlo program to compare the imaging characteristics between a whole-body SPECT system equipped with TlBr (T-SPECT) and a system equipped with CZT detectors (C-SPECT). The simulations were performed using a three-dimensional brain phantom and a National Electrical Manufacturers Association body phantom to evaluate 99mTc and 177Lu imaging. The simulation parameters were accurately set by comparing them with the actual measurements. Results: The T-SPECT system demonstrated improved energy resolution and higher detection efficiency than the C-SPECT system. In 99mTc imaging, T-SPECT demonstrated 1.71 times higher photopeak counts and improved contrast resolution. T-SPECT exhibited a significantly lower impact of hole tailing and higher-energy resolution (4.50% for T-SPECT vs. 7.34% for C-SPECT). Furthermore, T-SPECT showed higher peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) values, indicating better image quality. In 177Lu imaging, T-SPECT showed 2.76 times higher photopeak counts and improved energy resolution (3.94% for T-SPECT vs. 5.20% for C-SPECT). T-SPECT demonstrated a higher contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR) across all acquisition times, maintaining sufficient counts even with shorter acquisition times. Moreover, T-SPECT acquired higher low-frequency values in power spectrum density (PSD), indicating more accurate internal image reproduction. Conclusions: T-SPECT offers superior energy resolution and detection efficiency than C-SPECT. Moreover, T-SPECT can provide higher contrast resolution and sensitivity in clinical imaging with 99mTc and 177Lu. Furthermore, the Monte Carlo simulations are confirmed to be a valuable guide for the development of T-SPECT.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
development (new technology and techniques), instrumentation, Monte Carlo modeling, phantoms–digital
in
Medical Physics
volume
52
issue
6
pages
17 pages
publisher
John Wiley & Sons Inc.
external identifiers
  • pmid:40017160
  • scopus:85219612756
ISSN
0094-2405
DOI
10.1002/mp.17724
language
English
LU publication?
yes
id
c29f217f-6599-4a2f-a15b-ecdf0a7e25d7
date added to LUP
2025-06-30 11:00:03
date last changed
2025-07-14 11:37:25
@article{c29f217f-6599-4a2f-a15b-ecdf0a7e25d7,
  abstract     = {{<p>Background: Single-photon emission computed tomography (SPECT) devices equipped with cadmium–zinc–telluride (CZT) detectors achieve high contrast resolution because of their enhanced energy resolution. Recently, thallium bromide (TlBr) has gained attention as a detector material because of its high atomic number and density. Purpose: This study evaluated the clinical applicability of a SPECT system equipped with TlBr detectors using Monte Carlo simulations, focusing on 99mTc and 177Lu imaging. Methods: This study used the Simulation of Imaging Nuclear Detectors Monte Carlo program to compare the imaging characteristics between a whole-body SPECT system equipped with TlBr (T-SPECT) and a system equipped with CZT detectors (C-SPECT). The simulations were performed using a three-dimensional brain phantom and a National Electrical Manufacturers Association body phantom to evaluate 99mTc and 177Lu imaging. The simulation parameters were accurately set by comparing them with the actual measurements. Results: The T-SPECT system demonstrated improved energy resolution and higher detection efficiency than the C-SPECT system. In 99mTc imaging, T-SPECT demonstrated 1.71 times higher photopeak counts and improved contrast resolution. T-SPECT exhibited a significantly lower impact of hole tailing and higher-energy resolution (4.50% for T-SPECT vs. 7.34% for C-SPECT). Furthermore, T-SPECT showed higher peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) values, indicating better image quality. In 177Lu imaging, T-SPECT showed 2.76 times higher photopeak counts and improved energy resolution (3.94% for T-SPECT vs. 5.20% for C-SPECT). T-SPECT demonstrated a higher contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR) across all acquisition times, maintaining sufficient counts even with shorter acquisition times. Moreover, T-SPECT acquired higher low-frequency values in power spectrum density (PSD), indicating more accurate internal image reproduction. Conclusions: T-SPECT offers superior energy resolution and detection efficiency than C-SPECT. Moreover, T-SPECT can provide higher contrast resolution and sensitivity in clinical imaging with 99mTc and 177Lu. Furthermore, the Monte Carlo simulations are confirmed to be a valuable guide for the development of T-SPECT.</p>}},
  author       = {{Ito, Toshimune and Hitomi, Keitaro and Ljungberg, Michael and Kawasaki, Sousei and Katayama, Yuka and Kato, Akane and Tsuchikame, Hirotatsu and Suzuki, Kentaro and Miyazaki, Kyosuke and Mogi, Ritsushi}},
  issn         = {{0094-2405}},
  keywords     = {{development (new technology and techniques); instrumentation; Monte Carlo modeling; phantoms–digital}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{4079--4095}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Medical Physics}},
  title        = {{Accuracy of a whole-body single-photon emission computed tomography with a thallium-bromide detector : Verification via Monte Carlo simulations}},
  url          = {{http://dx.doi.org/10.1002/mp.17724}},
  doi          = {{10.1002/mp.17724}},
  volume       = {{52}},
  year         = {{2025}},
}