Improvement in PET/CT image quality in overweight patients with PSF and TOF
Open accessAbstract
Objective: The aim of this study was to evaluate the effect of the point spread function (PSF) and time of flight (TOF) on PET/CT images of overweight patients in relation to the iteration number and the acquisition time. Methods: This study consisted of a phantom study and a clinical study. The NEMA IEC body phantom and a 40 cm diameter large phantom (LG phantom) simulating an overweight patient were used in this study. Both phantoms were filled with 18 F solution with a sphere to background ratio of 4:1. The PET data were reconstructed with the baseline ordered-subsets expectation maximization (OSEM) algorithm, with the OSEM + PSF model, with the OSEM + TOF model and with the OSEM + PSF + TOF model. The clinical study was a retrospective analysis of 66 patients who underwent 18 F-FDG PET/CT. The image quality was evaluated using the background variability (coefficient of variance, CV phantom and CV liver) and the contrast (CONT HOT and SNR). Results: In phantom study, the CV phantom of the LG phantom was higher than that of the NEMA phantom. The PSF decreased the CV phantom of the LG phantom to the NEMA phantom level. The TOF information accelerated the CV phantom plateau earlier. The best relationship between the CV phantom and the CONT HOT was observed for the OSEM + PSF + TOF. In clinical study, the combination of PSF and TOF decreased the CV liver for overweight patients to that for normal weight patients while it increased the SNR similarly between two patient groups. Conclusion: The combination of the PSF and TOF correction improved the image quality of the LG phantom and overweight patients.
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PSF compensation can increase the SNR and subjectively rated image quality.
“PSF compensation can also increase the SNR [157,158] and thereby the subjectively rated image quality [157,161,162].”
From Influences on PET Quantification and Interpretation (2022) · cites this paper as [158]
The Discussion reports improved SNR in images reconstructed with PSF and TOF information, with the greatest improvement from their combination. The Methods describe observer ratings of phantom-sphere visibility, but the paper does not show that increased SNR caused an improvement in subjectively rated image quality. Its clinical image-quality assessment used quantitative measures. (LLM, conf=0.85)
Experimental — accuracy not yet measuredCompared to standard OSEM reconstruction, OSEM with TOF shows improved noise characteristics.
“Compared to standard ordered subset expectation maximization (OSEM) reconstruction, OSEM with TOF shows improved noise characteristics [49,94,156,157,158].”
From Influences on PET Quantification and Interpretation (2022) · cites this paper as [158]
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Cites
(2001) · PubMed · Cited by 943 · see citing works
Surti, S., Kuhn, A., Werner, M. E., Perkins, A. E., Kolthammer, J. A., & Karp, J. S. (2007) · PubMed · Cited by 639 · see citing works
Benefit of Time-of-Flight in PET: Experimental and Clinical Results
Karp, J. S., Surti, S., Daube-Witherspoon, M. E., & Muehllehner, G. (2008) · Journal of Nuclear Medicine · doi:10.2967/jnumed.107.044834 · Cited by 585 · see citing works
Fully 3-D PET reconstruction with system matrix derived from point source measurements
Panin, V. Y., Kehren, F., Michel, C., & Casey, M. (2006) · IEEE Transactions on Medical Imaging · doi:10.1109/tmi.2006.876171 · Cited by 536 · see citing works
Focus on time-of-flight PET: the benefits of improved time resolution
Conti, M. (2011) · European Journal of Nuclear Medicine and Molecular Imaging · doi:10.1007/s00259-010-1711-y · Cited by 335 · see citing works
Impact of Time-of-Flight on PET Tumor Detection
Kadrmas, D. J., Casey, M. E., Conti, M., Jakoby, B. W., Lois, C., & Townsend, D. W. (2009) · Journal of Nuclear Medicine · doi:10.2967/jnumed.109.063016 · Cited by 277 · see citing works
An Assessment of the Impact of Incorporating Time-of-Flight Information into Clinical PET/CT Imaging
Lois, C., Jakoby, B., Long, M. J., Hübner, K. F., Barker, D. W., Casey, M., Conti, M., Panin, V., Kadrmas, D. J., & Townsend, D. W. (2010) · Journal of Nuclear Medicine · doi:10.2967/jnumed.109.068098 · Cited by 263 · see citing works
Oncological applications of FDG PET imaging: brain tumors, colorectal cancer, lymphoma and melanoma.
Delbeke, D. (1999) · PubMed · Cited by 231 · see citing works
Akamatsu, G., Ishikawa, K., Mitsumoto, K., Taniguchi, T., Ohya, N., Baba, S., Abe, K., & Sasaki, M. (2012) · Journal of Nuclear Medicine · doi:10.2967/jnumed.112.103861 · Cited by 206 · see citing works
Self-citationImprovement in Lesion Detection with Whole-Body Oncologic Time-of-Flight PET
Fakhri, G. E., Surti, S., Trott, C. M., Scheuermann, J. S., & Karp, J. S. (2011) · Journal of Nuclear Medicine · doi:10.2967/jnumed.110.080382 · Cited by 199 · see citing works
Workman, R. B., & Coleman, R. E. (2006) · Springer eBooks · doi:10.1007/978-0-387-38335-4_3 · Cited by 176 · see citing works
(2004) · PubMed · Cited by 141 · see citing works
Surti, S., Scheuermann, J., El Fakhri, G., Daube-Witherspoon, M. E., Lim, R., Abi-Hatem, N., Moussallem, E., Benard, F., Mankoff, D., & Karp, J. S. (2011) · Journal of Nuclear Medicine · doi:10.2967/jnumed.110.086678 · Cited by 104 · see citing works
Masuda, Y., Kondo, C., Matsuo, Y., Uetani, M., & Kusakabe, K. (2009) · Journal of Nuclear Medicine · doi:10.2967/jnumed.108.060590 · Cited by 104 · see citing works
(2005) · PubMed · Cited by 103 · see citing works
Akamatsu, G., Mitsumoto, K., Taniguchi, T., Tsutsui, Y., Baba, S., & Sasaki, M. (2014) · European Journal of Radiology · doi:10.1016/j.ejrad.2013.09.030 · Cited by 96 · see citing works
Self-citationExperimental evaluation of a simple lesion detection task with time-of-flight PET
Surti, S., & Karp, J. S. (2008) · Physics in Medicine and Biology · doi:10.1088/0031-9155/54/2/013 · Cited by 87 · see citing works
Japanese guideline for the oncology FDG-PET/CT data acquisition protocol: synopsis of Version 1.0
Fukukita, H., Senda, M., Terauchi, T., Suzuki, K., Daisaki, H., Matsumoto, K., Ikari, Y., & Hayashi, M. (2010) · Annals of Nuclear Medicine · doi:10.1007/s12149-010-0377-7 · Cited by 83 · see citing works
Patient Weight-Based Acquisition Protocols to Optimize18F-FDG PET/CT Image Quality
Nagaki, A., Onoguchi, M., & Matsutomo, N. (2011) · Journal of Nuclear Medicine Technology · doi:10.2967/jnmt.110.081661 · Cited by 51 · see citing works
Impact of body habitus on quantitative and qualitative image quality in whole-body FDG-PET
Tatsumi, M., Clark, P., Nakamoto, Y., & Wahl, R. L. (2003) · European Journal of Nuclear Medicine and Molecular Imaging · doi:10.1007/s00259-002-0980-5 · Cited by 34 · see citing works
Martí-Climent, J. M., Prieto, E., Domínguez‐Prado, I., García‐Velloso, M. J., Rodríguez‐Fraile, M., Arbizu, J., Vigil, C., Caicedo, C., Peñuelas, I., & Richter, J. Á. (2013) · Revista Española de Medicina Nuclear e Imagen Molecular (English Edition) · doi:10.1016/j.remnie.2012.11.012 · Cited by 32 · see citing works
Akamatsu, G., Mitsumoto, K., Ishikawa, K., Taniguchi, T., Ohya, N., Baba, S., Abe, K., & Sasaki, M. (2013) · Clinical Nuclear Medicine · doi:10.1097/rlu.0b013e31828da3bd · Cited by 27 · see citing works
Self-citationRelationship between changes in body weight and waist circumference in Japanese
Miyatake, N., Matsumoto, S., Miyachi, M., Fujii, M., & Numata, T. (2007) · Environmental Health and Preventive Medicine · doi:10.1265/ehpm.12.220 · Cited by 18 · see citing works
Akamatsu, G., Uba, K., Taniguchi, T., Mitsumoto, K., Narisue, A., Tsutsui, Y., & Sasaki, M. (2014) · Journal of Nuclear Medicine Technology · doi:10.2967/jnmt.114.140665 · Cited by 17 · see citing works
Self-citationOptimization of time-of-flight reconstruction on Philips GEMINI TF
Vandenberghe, S., van Elmbt, L., Guerchaft, M., Clementel, E., Verhaeghe, J. A. J., Bol, A., Lemahieu, I. A., & Lonneux, M. (2009) · European Journal of Nuclear Medicine and Molecular Imaging · doi:10.1007/s00259-009-1164-3 · Cited by 16 · see citing works
Patient weight-based acquisition protocols to optimize 18F-FDG PET/CT image quality
長木, 昭. (2012) · Kanazawa University Repository for Academic Resources (DSpace) (Kanazawa University) · Cited by 4 · see citing works
Flagged first, then by citations
Cited by
Sorted by citations
The new opportunities for high time resolution clinical TOF PET
Conti, M., & Bendriem, B. (2019) · Clinical and Translational Imaging · doi:10.1007/s40336-019-00316-5 · Cited by 151 · see citing works
Akamatsu, G., Ikari, Y., Nishida, H., Nishio, T., Ohnishi, A., Maebatake, A., Sasaki, M., & Senda, M. (2015) · Journal of Nuclear Medicine Technology · doi:10.2967/jnmt.115.161745 · Cited by 85 · see citing works
Self-citationGnesin, S., Kieffer, C., Zeimpekis, K., Papazyan, J. P., Guignard, R., Prior, J. O., Verdun, F. R., & Lima, T. V. M. (2020) · EJNMMI Physics · doi:10.1186/s40658-019-0269-4 · Cited by 83 · see citing works
SiPM applications in positron emission tomography: toward ultimate PET time-of-flight resolution
Lecoq, P. R., & Gundacker, S. (2021) · The European Physical Journal Plus · doi:10.1140/epjp/s13360-021-01183-8 · Cited by 79 · see citing works
Salvadori, J., Odille, F., Verger, A., Olivier, P., Karcher, G., Marie, P., & Imbert, L. (2020) · EJNMMI Physics · doi:10.1186/s40658-020-0281-8 · Cited by 51 · see citing works
Influences on PET Quantification and Interpretation
Rogasch, J. M. M., Hofheinz, F., van Heek, L., Voltin, C.-A., Boellaard, R., & Kobe, C. (2022) · Diagnostics · doi:10.3390/diagnostics12020451 · Cited by 50 · see citing works
Rogasch, J. M., Steffen, I. G., Hofheinz, F., Großer, O. S., Furth, C., Mohnike, K., Hass, P., Walke, M., Apostolova, I., & Amthauer, H. (2015) · EJNMMI Research · doi:10.1186/s13550-015-0111-5 · Cited by 43 · see citing works
Lasnon, C., Salomon, T., Desmonts, C., Dô, P., Oulkhouir, Y., Madelaine, J., & Aide, N. (2016) · Annals of Nuclear Medicine · doi:10.1007/s12149-016-1135-2 · Cited by 41 · see citing works
Hashimoto, N., Morita, K., Tsutsui, Y., Himuro, K., Baba, S., & Sasaki, M. (2018) · Journal of Nuclear Medicine Technology · doi:10.2967/jnmt.117.204735 · Cited by 26 · see citing works
Self-citationShang, K., Cui, B., Ma, J., Shuai, D., Liang, Z., Jansen, F. P., Zhou, Y., Lu, J., & Zhao, G. (2017) · European Journal of Radiology · doi:10.1016/j.ejrad.2017.05.029 · Cited by 21 · see citing works
Vennart, N. J., Bird, N. J., Buscombe, J. R., Cheow, H., Nowosinska, E., & Heard, S. (2017) · Nuclear Medicine Communications · doi:10.1097/mnm.0000000000000669 · Cited by 19 · see citing works
Behr, S. C., Bahroos, E., Hawkins, R. A., Nardo, L., Ravanfar, V., Capbarat, E. V., & Seo, Y. (2017) · Molecular Imaging and Biology · doi:10.1007/s11307-017-1145-z · Cited by 15 · see citing works
Advancing Precision Nuclear Medicine and Molecular Imaging for Lymphoma
Wright, C., Maly, J. J., Zhang, J., & Knopp, M. V. (2016) · PET Clinics · doi:10.1016/j.cpet.2016.08.005 · Cited by 14 · see citing works
Xu, L., Cui, C., Li, R., Yang, R., Liu, R., Meng, Q., & Wang, F. (2022) · EJNMMI Research · doi:10.1186/s13550-022-00945-4 · Cited by 12 · see citing works
Rana, N., Kaur, M., Singh, H., & Mittal, B. R. (2020) · Journal of Nuclear Medicine Technology · doi:10.2967/jnmt.120.250282 · Cited by 10 · see citing works
Bouchareb, Y., Tag, N., Sulaiman, H., Riyami, K. A., Jawa, Z. M., & Al-Dhuhli, H. (2023) · Nuclear Medicine and Molecular Imaging · doi:10.1007/s13139-023-00795-5 · Cited by 11 · see citing works
Dasari, P. K. R., Jones, J. P., Casey, M., Liang, Y., Dilsizian, V., & Smith, M. F. (2018) · Journal of Nuclear Cardiology · doi:10.1007/s12350-018-1311-y · Cited by 9 · see citing works
Rezaei, S., Ghafarian, P., Jha, A. K., Rahmim, A., Sarkar, S., & Ay, M. R. (2019) · Physica Medica · doi:10.1016/j.ejmp.2019.10.031 · Cited by 8 · see citing works
Rezaei, S., Ghafarian, P., Karam, M. B., Uribe, C., Rahmim, A., Sarkar, S., & Ay, M. R. (2020) · Japanese Journal of Radiology · doi:10.1007/s11604-019-00914-3 · Cited by 8 · see citing works
Lu, S., Zhang, P., Li, C., Sun, J., Liu, W., & Zhang, P. (2021) · BMC Medical Imaging · doi:10.1186/s12880-021-00683-4 · Cited by 7 · see citing works
Monaco, L., Ponti, E. D., Crivellaro, C., Morzenti, S., Todde, S., Landoni, C., Elisei, F., Musarra, M., & Guerra, L. (2022) · Current Radiopharmaceuticals · doi:10.2174/1874471015666220107100200 · Cited by 6 · see citing works
Impact of patient body habitus on image quality and quantitative value in bone SPECT/CT
Fukai, S., Daisaki, H., Umeda, T., Shimada, N., Miyaji, N., Ito, R., Takiguchi, T., & Terauchi, T. (2022) · Annals of Nuclear Medicine · doi:10.1007/s12149-022-01746-4 · Cited by 6 · see citing works
Maebatake, A., Akamatsu, G., Miwa, K., Tsutsui, Y., Himuro, K., Baba, S., & Sasaki, M. (2015) · Annals of Nuclear Medicine · doi:10.1007/s12149-015-1032-0 · Cited by 5 · see citing works
Self-citationZhang, J., Sun, Y., Zhang, Y., & Teng, J. (2017) · EURASIP Journal on Image and Video Processing · doi:10.1186/s13640-017-0218-x · Cited by 3 · see citing works
18F-FDG PET Adults Whole-Body Scan Injected Dose Optimization: A Mini Review
(2023) · Journal of Population Therapeutics and Clinical Pharmacology · doi:10.47750/jptcp.2023.1113 · Cited by 2 · see citing works
Dasari, P. K. R., Jones, J. P., Casey, M., & Smith, M. F. (2017) · IEEE Transactions on Radiation and Plasma Medical Sciences · doi:10.1109/trpms.2017.2715047 · Cited by 3 · see citing works
Mohymen, A. A., Farag, H. I., Reda, S., Monem, A. S., & Ali, S. A. (2025) · Applied Radiation and Isotopes · doi:10.1016/j.apradiso.2025.111761 · Cited by 2 · see citing works
Maronnier, Q., Robaine, N., Chaltiel, L., Dierickx, L., Cassou‐Mounat, T., Terroir-Cassou-Mounat, M., Vija, L., Vallot, D., Brillouet, S., Lamesa, C., et al. (2024) · EJNMMI Physics · doi:10.1186/s40658-023-00610-2 · Cited by 2 · see citing works
Monsef, A., Sheikhzadeh, P., Steiner, J. R., Sadeghi, F., Yazdani, M., & Ghafarian, P. (2024) · Biomedical Physics & Engineering Express · doi:10.1088/2057-1976/ad3e00 · Cited by 2 · see citing works
Modification of [18F]-FDG PET/CT imaging protocols in obese oncology patients: A nationwide survey
Oliveira, R. S., Figueiredo, L., & Costa, P. (2022) · Radiography · doi:10.1016/j.radi.2022.10.016 · Cited by 2 · see citing works
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Sekikawa, Y., Funada, K., Akamatsu, G., Himuro, K., Takahashi, A., Baba, S., & Sasaki, M. (2021) · Annals of Nuclear Medicine · doi:10.1007/s12149-021-01620-9 · Cited by 2 · see citing works
Self-citationSun, Y., Fei, T., Zhang, L., Liu, X., & Zhang, J. (2018) · Automatic Control and Computer Sciences · doi:10.3103/s0146411618010078 · Cited by 2 · see citing works
Guglielmo, P., Laudicella, R., Rovera, G., Filice, A., Panareo, S., Chierichetti, F., Zorz, A., Ferretti, S., Iudicello, A., Frantellizzi, V., et al. (2024) · Clinical and Translational Imaging · doi:10.1007/s40336-024-00675-8 · Cited by 1 · see citing works
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Akamatsu, G., 木寺, 大., 前畠, 彬., 光元, 勝., 筒井, 悠., 三輪, 建., & 佐々木, 雅. (2015) · Japanese Journal of Radiological Technology · doi:10.6009/jjrt.2015_jsrt_71.11.1115 · Cited by 1 · see citing works
Self-citationOwaki, Y., Minamishima, K., & Nakajima, K. (2022) · Nuclear Medicine Communications · doi:10.1097/mnm.0000000000001527 · Cited by 1 · see citing works
Hotsumi, H., Ishii, S., Suenaga, H., Sugawara, S., Fukushima, K., & Ito, H. (2023) · PubMed Central · Cited by 1 · see citing works
Ghafarian, P., Rezaei, S., Gharepapagh, E., Sarkar, S., & Ay, M. R. (2022) · Iranian South Medical Journal · doi:10.52547/ismj.25.4.355 · Cited by 1 · see citing works
O33. The value of different reconstruction algorithms for quantification of FDG PET brain imaging
Moalosi, T. C. G., Dupont, P. J., Mix, M. D., Warwick, J., Toit, M. D. D., & Doruyter, A. (2016) · Physica Medica · doi:10.1016/j.ejmp.2016.07.041 · Cited by 1 · see citing works
Antić, V., & Haglund, J. (2016) · RAD Conference Proceedings. · doi:10.21175/radproc.2016.29
The Impact of Patient’s Body Habitus on PET Image Quality in Digital and Analogic PET/CTPreprint
Weyts, K., Quak, E., Licaj, I., Lasnon, C., Ciappuccini, R., Foucras, G., Savigny, J.-F., Bardet, S., & Jaudet, C. (2020) · Research Square · doi:10.21203/rs.3.rs-56118/v1
A PET/CT Phantom for Evaluating The PET Image Quality of Micro-Lesion and CT Performance ParametersPreprint
Lu, S., Zhang, P., Li, C., Sun, J., Liu, W., & Zhang, P. (2020) · Research Square · doi:10.21203/rs.3.rs-108386/v1
Comparison of PSF and Non PSF BLOB based reconstructed image in Time-of-Flight PET/CT
Vishwakarma, M. K. (2021) · International Journal of Pharmaceutical and Bio-Medical Science · doi:10.47191/ijpbms/v1-i8-03
Xu, L., Cui, C., Li, R., Yang, R., Liu, R., Meng, Q., & Wang, F. (2022) · Research Square · doi:10.21203/rs.3.rs-1310776/v1
Rezvani, S., Ghafarian, P., Karam, M. B., & Ay, M. (2023) · Innovative Journal of Radiology · doi:10.5812/ijr-129306
Rezvani, S., Ghafarian, P., Karam, M. B., & Ay, M. (2023) · Iranian Journal of Radiology · doi:10.5812/iranjradiol-129306
Petryakova, A. V., Чипига, Л. А., Andreev, G. А., Gromova, E. A., Катаева, Г. В., Kovalev, K. V., Onischenko, S. S., & Bezumova, E. V. (2024) · Radiacionnaâ gigiena · doi:10.21514/1998-426x-2024-17-1-44-53
Mohamed, A. A., Farag, H. I., Reda, S., Soltan, A., & Ali, S. A. (2024) · SSRN Electronic Journal · doi:10.2139/ssrn.4812783
Ogasawara, R., Irikawa, A., Watanabe, Y., Harada, T., Hosokawa, S., Koyama, K., Tsuda, K., Kimura, T., Okuda, K., & Takahashi, Y. (2025) · Radiation · doi:10.3390/radiation5020018
Xu, L., Cui, C., Li, R., Yang, R., Liu, R., Meng, Q., & Wang, F. (2023) · Figshare · doi:10.6084/m9.figshare.22602265
Legodi, K., Qebetu, M., Banda, K., Goorhoo, P., López-Montes, A., Shi, K., Sathekge, M. M., & Ramonaheng, K. (2026) · Biomedical Physics & Engineering Express · doi:10.1088/2057-1976/ae7577
Wang, J., Huang, J., Cui, B., Yang, H., Tian, D., Ma, J., Duan, W., Chen, Z., & Lu, J. (2026) · EJNMMI Physics · doi:10.1186/s40658-026-00922-z
- Authors
- Taniguchi, T., Akamatsu, G., Kasahara, Y., Mitsumoto, K., Baba, S., Tsutsui, Y., Himuro, K., Mikasa, S., Kidera, D., & Sasaki, M.
- Affiliations
- Kyushu University (JP)
- Corresponding author
- Sasaki, Masayuki
- Venue
- Annals of Nuclear Medicine
- Published
- 2014-09-26
- Volume
- 29
- Issue
- 1
- Pages
- 71-77
- ISSN
- 0914-7187 (ISSN-L)
- 1864-6433
- PMC
- PMC4661192
- OpenAlex
- W1987671573
- Cited by
- 53
- References
- 26
- Citations by year
- 2026: 2 · 2025: 2 · 2024: 5 · 2023: 6 · 2022: 8 · 2021: 4 · 2020: 7 · 2019: 3 · 2018: 3 · 2017: 5 · 2016: 4 · 2015: 4
- FWCI
- 3.39
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Locations
- Annals of Nuclear Medicine (publishedVersion, cc-by)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Radiology, Nuclear Medicine and Imaging › Medical Imaging Techniques and Applications
- Health Sciences › Medicine › Radiology, Nuclear Medicine and Imaging › Cardiac Imaging and Diagnostics
- Health Sciences › Medicine › Radiology, Nuclear Medicine and Imaging › Radiation Dose and Imaging
- Keywords
- point spread function correction, time-of-flight correction, overweight patients, 18F-FDG PET, OSEM, background variation, coefficient of variation, signal-to-noise ratio
- MeSH terms
- Adult, Aged, Aged, 80 and over, Algorithms, Female, Humans, Male, Middle Aged, Models, Biological, Retrospective Studies, Tomography, X-Ray Computed, Phantoms, Imaging, Radiopharmaceuticals, Fluorodeoxyglucose F18, Positron-Emission Tomography, Overweight, Multimodal Imaging
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