Head-to-head Comparison Between Digital and Analog PET of Human and Phantom Images when Optimized for Maximizing the Signal-to-noise Ratio from Small Lesions

Overview

Journal EJNMMI Phys

Specialty Radiology

Date 2020 Feb 23

PMID 32086646

Citations 20

Authors

Julien Salvadori

Freddy Odille

Antoine Verger

Pierre Olivier

Gilles Karcher

Pierre-Yves Marie

Laetitia Imbert

Affiliations

Soon will be listed here.

Abstract

Background: Routine PET exams are increasingly performed with reduced injected activities, leading to the use of different image reconstruction parameters than the NEMA parameters, in order to prevent from any deleterious decrease in signal-to-noise ratio (SNR) and thus, in lesion detectability. This study aimed to provide a global head-to-head comparison between digital (Vereos, Philips®) and analog (Ingenuity TF, Philips®) PET cameras of the trade-off between SNR and contrast through a wide-ranging number of reconstruction iterations, and with a further reconstruction optimization based on the SNR of small lesions.

Methods: Image quality parameters were compared between the two cameras on human and phantom images for a number of OSEM reconstruction iterations ranging from 1 to 10, the number of subsets being fixed at 10, and with the further identification of reconstruction parameters maximizing the SNR of spheres and adenopathies nearing 10 mm in diameter. These reconstructions were additionally obtained with and without time-of-flight (TOF) information (TOF and noTOF images, respectively) for further comparisons.

Results: On both human and phantom TOF images, the compromise between SNR and contrast was consistently more advantageous for digital than analog PET, with the difference being particularly pronounced for the lowest numbers of iterations and the smallest spheres. SNR was maximized with 1 and 2 OSEM iterations for the TOF images from digital and analog PET, respectively, whereas 4 OSEM iterations were required for the corresponding noTOF images from both cameras. On the TOF images obtained with this SNR optimization, digital PET exhibited a 37% to 44% higher SNR as compared with analog PET, depending on sphere size. These relative differences were however much lower for the noTOF images optimized for SNR (- 4 to + 18%), as well as for images reconstructed according to NEMA standards (- 4 to + 12%).

Conclusion: SNR may be dramatically higher for digital PET than for analog PET, especially when optimized for small lesions. This superiority is mostly attributable to enhanced TOF resolution and is significantly underestimated in NEMA-based analyses.

Citing Articles

Calculation of recovery coefficients for partial volume effect correction in PET/CT imaging using a customized anthropomorphic body phantom.

Yavuz G, Kovan B, Toklu T, Cermik T, Ozturk C Biomed Eng Online. 2025; 24(1):20.

PMID: 39955528 PMC: 11830175. DOI: 10.1186/s12938-025-01330-7.

Investigation and optimization of PET-guided SPECT reconstructions for improved radionuclide therapy dosimetry estimates.

Marquis H, Willowson K, Schmidtlein C, Bailey D Front Nucl Med. 2024; 3:1124283.

PMID: 39380952 PMC: 11460090. DOI: 10.3389/fnume.2023.1124283.

Feasibility of direct brain F-fluorodeoxyglucose-positron emission tomography attenuation and high-resolution correction methods using deep learning.

Ueda T, Yamashita K, Kawazoe R, Sayawaki Y, Morisawa Y, Kamezaki R Asia Ocean J Nucl Med Biol. 2024; 12(2):108-119.

PMID: 39050241 PMC: 11263769. DOI: 10.22038/AOJNMB.2024.74875.1522.

Long-axial-field of view in prostate cancer next generation imaging: the launch pad of theragnostic.

Volpe F, Nappi C, Klain M Eur J Nucl Med Mol Imaging. 2024; 51(7):2134-2136.

PMID: 38351388 DOI: 10.1007/s00259-024-06647-4.

Ultra-fast whole-body bone tomoscintigraphies achieved with a high-sensitivity 360° CZT camera and a dedicated deep-learning noise reduction algorithm.

Bahloul A, Verger A, Lamash Y, Roth N, Dari D, Marie P Eur J Nucl Med Mol Imaging. 2023; 51(5):1215-1220.

PMID: 38082197 DOI: 10.1007/s00259-023-06558-w.

References

Karp J, Surti S, Daube-Witherspoon M, Muehllehner G . Benefit of time-of-flight in PET: experimental and clinical results. J Nucl Med. 2008; 49(3):462-70. PMC: 2639717. DOI: 10.2967/jnumed.107.044834. View

Nguyen N, Vercher-Conejero J, Sattar A, Miller M, Maniawski P, Jordan D . Image Quality and Diagnostic Performance of a Digital PET Prototype in Patients with Oncologic Diseases: Initial Experience and Comparison with Analog PET. J Nucl Med. 2015; 56(9):1378-85. DOI: 10.2967/jnumed.114.148338. View

Surti S, Karp J . Advances in time-of-flight PET. Phys Med. 2016; 32(1):12-22. PMC: 4747834. DOI: 10.1016/j.ejmp.2015.12.007. View

Sah B, Ghafoor S, Burger I, Ter Voert E, Sekine T, Delso G . Feasibility of F-FDG Dose Reductions in Breast Cancer PET/MRI. J Nucl Med. 2018; 59(12):1817-1822. DOI: 10.2967/jnumed.118.209007. View

Rausch I, Ruiz A, Valverde-Pascual I, Cal-Gonzalez J, Beyer T, Carrio I . Performance Evaluation of the Vereos PET/CT System According to the NEMA NU2-2012 Standard. J Nucl Med. 2018; 60(4):561-567. DOI: 10.2967/jnumed.118.215541. View

Kolthammer J, Su K, Grover A, Narayanan M, Jordan D, Muzic R . Performance evaluation of the Ingenuity TF PET/CT scanner with a focus on high count-rate conditions. Phys Med Biol. 2014; 59(14):3843-59. PMC: 4457340. DOI: 10.1088/0031-9155/59/14/3843. View

Ahn S, Ross S, Asma E, Miao J, Jin X, Cheng L . Quantitative comparison of OSEM and penalized likelihood image reconstruction using relative difference penalties for clinical PET. Phys Med Biol. 2015; 60(15):5733-51. DOI: 10.1088/0031-9155/60/15/5733. View

Karakatsanis N, Fokou E, Tsoumpas C . Dosage optimization in positron emission tomography: state-of-the-art methods and future prospects. Am J Nucl Med Mol Imaging. 2015; 5(5):527-47. PMC: 4620179. View

Brasse D, Kinahan P, Lartizien C, Comtat C, Casey M, Michel C . Correction methods for random coincidences in fully 3D whole-body PET: impact on data and image quality. J Nucl Med. 2005; 46(5):859-67. View

10.

Wright C, Binzel K, Zhang J, Knopp M . Advanced Functional Tumor Imaging and Precision Nuclear Medicine Enabled by Digital PET Technologies. Contrast Media Mol Imaging. 2017; 2017:5260305. PMC: 5612735. DOI: 10.1155/2017/5260305. View

11.

van Sluis J, de Jong J, Schaar J, Noordzij W, van Snick P, Dierckx R . Performance Characteristics of the Digital Biograph Vision PET/CT System. J Nucl Med. 2019; 60(7):1031-1036. DOI: 10.2967/jnumed.118.215418. View

12.

van der Vos C, Koopman D, Rijnsdorp S, Arends A, Boellaard R, van Dalen J . Quantification, improvement, and harmonization of small lesion detection with state-of-the-art PET. Eur J Nucl Med Mol Imaging. 2017; 44(Suppl 1):4-16. PMC: 5541089. DOI: 10.1007/s00259-017-3727-z. View

13.

Lopez-Mora D, Flotats A, Fuentes-Ocampo F, Camacho V, Fernandez A, Ruiz A . Comparison of image quality and lesion detection between digital and analog PET/CT. Eur J Nucl Med Mol Imaging. 2019; 46(6):1383-1390. DOI: 10.1007/s00259-019-4260-z. View

14.

Taniguchi T, Akamatsu G, Kasahara Y, Mitsumoto K, Baba S, Tsutsui Y . Improvement in PET/CT image quality in overweight patients with PSF and TOF. Ann Nucl Med. 2014; 29(1):71-7. PMC: 4661192. DOI: 10.1007/s12149-014-0912-z. View

15.

Fuentes-Ocampo F, Lopez-Mora D, Flotats A, Paillahueque G, Camacho V, Duch J . Digital vs. analog PET/CT: intra-subject comparison of the SUVmax in target lesions and reference regions. Eur J Nucl Med Mol Imaging. 2019; 46(8):1745-1750. DOI: 10.1007/s00259-018-4256-0. View

16.

Lois C, Jakoby B, Long M, Hubner K, Barker D, Casey M . An assessment of the impact of incorporating time-of-flight information into clinical PET/CT imaging. J Nucl Med. 2010; 51(2):237-45. PMC: 2818518. DOI: 10.2967/jnumed.109.068098. View

17.

Akamatsu G, Ishikawa K, Mitsumoto K, Taniguchi T, Ohya N, Baba S . Improvement in PET/CT image quality with a combination of point-spread function and time-of-flight in relation to reconstruction parameters. J Nucl Med. 2012; 53(11):1716-22. DOI: 10.2967/jnumed.112.103861. View

18.

Rahmim A, Qi J, Sossi V . Resolution modeling in PET imaging: theory, practice, benefits, and pitfalls. Med Phys. 2013; 40(6):064301. PMC: 3663852. DOI: 10.1118/1.4800806. View

19.

Salvadori J, Perrin M, Marie P, Imbert L, Verger A . High-Resolution Brain 18F-FDG Images Provided by Fully Digital PET. Clin Nucl Med. 2019; 44(4):301-302. DOI: 10.1097/RLU.0000000000002483. View

20.

Karaoglanis K, Polycarpou I, Efthimiou N, Tsoumpas C . Appropriately regularized OSEM can improve the reconstructed PET images of data with low count statistics. Hell J Nucl Med. 2015; 18(2):140-5. DOI: 10.1967/s002449910209. View