1
|
He W, Zhao Y, Huang W, Zhao X, Niu M, Yang H, Zhang L, Ren Q, Gu Z. A multi-resolution TOF-DOI detector for human brain dedicated PET scanner. Phys Med Biol 2024; 69:025023. [PMID: 38181423 DOI: 10.1088/1361-6560/ad1b6b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 01/05/2024] [Indexed: 01/07/2024]
Abstract
Objective. We propose a single-ended readout, multi-resolution detector design that can achieve high spatial, depth-of-interaction (DOI), and time-of-flight (TOF) resolutions, as well as high sensitivity for human brain-dedicated positron emission tomography (PET) scanners.Approach. The detector comprised two layers of LYSO crystal arrays and a lightguide in between. The top (gamma ray entrance) layer consisted of a 16 × 16 array of 1.53 × 1.53 × 6 mm3LYSO crystals for providing high spatial resolution. The bottom layer consisted of an 8 × 8 array of 3.0 × 3.0 × 15 mm3LYSO crystals that were one-to-one coupled to an 8 × 8 multipixel photon counter (MPPC) array for providing high TOF resolution. The 2 mm thick lightguide introduces inter-crystal light sharing that causes variations of the light distribution patterns for high DOI resolution. The detector was read out by a PETsys TOFPET2 application-specific integrated circuit.Main result. The top and bottom layers were distinguished by a convolutional neural network with 97% accuracy. All crystals in the top and bottom layers were resolved. The inter-crystal scatter (ICS) events in the bottom layer were identified, and the measured average DOI resolution of the bottom layer was 4.1 mm. The coincidence time resolution (CTR) for the top-top, top-bottom, and bottom-bottom coincidences was 476 ps, 405 ps, and 298 ps, respectively. When ICS events were excluded from the bottom layer, the CTR of the bottom-bottom coincidence was 277 ps.Significance. The top layer of the proposed two-layer detector achieved a high spatial resolution and the bottom layer achieved a high TOF resolution. Together with its high DOI resolution and detection efficiency, the proposed detector is well suited for next-generation high-performance brain-dedicated PET scanners.
Collapse
Affiliation(s)
- Wen He
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
- Peking University Shenzhen Graduate School, Shenzhen, People's Republic of China
| | - Yangyang Zhao
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
| | - Wenjie Huang
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
| | - Xin Zhao
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
| | - Ming Niu
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
| | - Hang Yang
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
| | - Lei Zhang
- Peking University Shenzhen Graduate School, Shenzhen, People's Republic of China
- Institute of Cancer Research, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
| | - Qiushi Ren
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
- Peking University Shenzhen Graduate School, Shenzhen, People's Republic of China
| | - Zheng Gu
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, People's Republic of China
- Peking University Shenzhen Graduate School, Shenzhen, People's Republic of China
| |
Collapse
|
2
|
Sanaat A, Amini M, Arabi H, Zaidi H. The quest for multifunctional and dedicated PET instrumentation with irregular geometries. Ann Nucl Med 2024; 38:31-70. [PMID: 37952197 PMCID: PMC10766666 DOI: 10.1007/s12149-023-01881-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 10/09/2023] [Indexed: 11/14/2023]
Abstract
We focus on reviewing state-of-the-art developments of dedicated PET scanners with irregular geometries and the potential of different aspects of multifunctional PET imaging. First, we discuss advances in non-conventional PET detector geometries. Then, we present innovative designs of organ-specific dedicated PET scanners for breast, brain, prostate, and cardiac imaging. We will also review challenges and possible artifacts by image reconstruction algorithms for PET scanners with irregular geometries, such as non-cylindrical and partial angular coverage geometries and how they can be addressed. Then, we attempt to address some open issues about cost/benefits analysis of dedicated PET scanners, how far are the theoretical conceptual designs from the market/clinic, and strategies to reduce fabrication cost without compromising performance.
Collapse
Affiliation(s)
- Amirhossein Sanaat
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Mehdi Amini
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Hossein Arabi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland.
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, 9700 RB, Groningen, The Netherlands.
- Department of Nuclear Medicine, University of Southern Denmark, 500, Odense, Denmark.
- University Research and Innovation Center, Óbuda University, Budapest, Hungary.
| |
Collapse
|
3
|
Allen MS, Scipioni M, Catana C. New Horizons in Brain PET Instrumentation. PET Clin 2024; 19:25-36. [PMID: 37806894 PMCID: PMC10840690 DOI: 10.1016/j.cpet.2023.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Dedicated brain PET scanners are optimized to provide high sensitivity and high spatial resolution compared with existing whole-body PET systems, and they can be much cheaper to produce and install in various clinical and research settings. Advancements in detector technology over the past few years have placed several standalone PET, PET/computed tomography, and PET/MR systems on or near the commercial market; the features and capabilities of these systems will be reviewed here.
Collapse
Affiliation(s)
- Magdelena S Allen
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital; Department of Physics, Massachusetts Institute of Technology
| | - Michele Scipioni
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital; Harvard Medical School
| | - Ciprian Catana
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital; Harvard Medical School.
| |
Collapse
|
4
|
Iwao Y, Akamatsu G, Tashima H, Takahashi M, Yamaya T. Pre-acquired CT-based attenuation correction with automated headrest removal for a brain-dedicated PET system. Radiol Phys Technol 2023; 16:552-559. [PMID: 37819445 DOI: 10.1007/s12194-023-00744-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 10/13/2023]
Abstract
Attenuation correction (AC) is essential for quantitative positron emission tomography (PET) images. Attenuation coefficient maps (μ-maps) are usually generated from computed tomography (CT) images when PET-CT combined systems are used. If CT has been performed prior to PET imaging, pre-acquired CT can be used for brain PET AC, because the human head is almost rigid. This pre-acquired CT-based AC approach is suitable for stand-alone brain-dedicated PET, such as VRAIN (ATOX Co. Ltd., Tokyo, Japan). However, the headrest of PET is different from the headrest in pre-acquired CT images, which may degrade the PET image quality. In this study, we prepared three different types of μ-maps: (1) based on the pre-acquired CT, where namely the headrest is different from the PET system (μ-map-diffHr); (2) manually removing the headrest from the pre-acquired CT (μ-map-noHr); and (3) artificially replacing the headrest region with the headrest of the PET system (μ-map-sameHr). Phantom images by VRAIN using each μ-map were investigated for uniformity, noise, and quantitative accuracy. Consequently, only the uniformity of the images using μ-map-diffHr was out of the acceptance criteria. We then proposed an automated method for removing the headrest from pre-acquired CT images. In comparisons of standardized uptake values in nine major brain regions from the 18F-fluoro-2-deoxy-D-glucose-PET of 10 healthy volunteers, no significant differences were found between the μ-map-noHr and the μ-map-sameHr. In conclusion, pre-acquired CT-based AC with automated headrest removal is useful for brain-dedicated PET such as VRAIN.
Collapse
Affiliation(s)
- Yuma Iwao
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.
| | - Go Akamatsu
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.
| | - Hideaki Tashima
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan
| | - Miwako Takahashi
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan
| | - Taiga Yamaya
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.
| |
Collapse
|
5
|
Akamatsu G, Tashima H, Yoshida E, Iwao Y, Takyu S, Wakizaka H, Takahashi M, Yamaya T. [[PET] 3. The World's First Hemispherical Brain PET System: VRAIN]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2023; 79:200-205. [PMID: 36804812 DOI: 10.6009/jjrt.2023-2161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- Go Akamatsu
- National Institutes for Quantum Science and Technology (QST)
| | - Hideaki Tashima
- National Institutes for Quantum Science and Technology (QST)
| | - Eiji Yoshida
- National Institutes for Quantum Science and Technology (QST)
| | - Yuma Iwao
- National Institutes for Quantum Science and Technology (QST)
| | - Sodai Takyu
- National Institutes for Quantum Science and Technology (QST)
| | | | | | - Taiga Yamaya
- National Institutes for Quantum Science and Technology (QST)
| |
Collapse
|
6
|
Akamatsu G, Tsutsui Y, Daisaki H, Mitsumoto K, Baba S, Sasaki M. A review of harmonization strategies for quantitative PET. Ann Nucl Med 2023; 37:71-88. [PMID: 36607466 PMCID: PMC9902332 DOI: 10.1007/s12149-022-01820-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 12/27/2022] [Indexed: 01/07/2023]
Abstract
PET can reveal in vivo biological processes at the molecular level. PET-derived quantitative values have been used as a surrogate marker for clinical decision-making in numerous clinical studies and trials. However, quantitative values in PET are variable depending on technical, biological, and physical factors. The variability may have a significant impact on a study outcome. Appropriate scanner calibration and quality control, standardization of imaging protocols, and any necessary harmonization strategies are essential to make use of PET as a biomarker with low bias and variability. This review summarizes benefits, limitations, and remaining challenges for harmonization of quantitative PET, including whole-body PET in oncology, brain PET in neurology, PET/MR, and non-18F PET imaging. This review is expected to facilitate harmonization of quantitative PET and to promote the contribution of PET-derived biomarkers to research and development in medicine.
Collapse
Affiliation(s)
- Go Akamatsu
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Sciences, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan. .,Department of Molecular Imaging Research, Kobe City Medical Center General Hospital, 2-1-1 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.
| | - Yuji Tsutsui
- Department of Radiological Science, Faculty of Health Science, Junshin Gakuen University, 1-1-1 Chikushigaoka, Minami-ku, Fukuoka, 815-8510 Japan
| | - Hiromitsu Daisaki
- Department of Radiological Technology, Gunma Prefectural College of Health Sciences, 323-1 Kamioki-machi, Maebashi, Gunma 371-0052 Japan
| | - Katsuhiko Mitsumoto
- Department of Clinical Radiology Service, Kyoto University Hospital, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto, 606-8507 Japan
| | - Shingo Baba
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan
| | - Masayuki Sasaki
- Department of Medical Quantum Science, Faculty of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan
| |
Collapse
|