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Wang Q, Abdelhafez YG, Nalbant H, Spencer BA, Bayerlein R, Qi J, Cherry SR, Nardo L, Badawi RD. Refining penalty parameter selection in whole-body PET image reconstruction for lung cancer patients using the cross-validation log-likelihood method. Phys Med Biol 2024; 69:185002. [PMID: 39168154 DOI: 10.1088/1361-6560/ad7222] [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: 05/31/2024] [Accepted: 08/21/2024] [Indexed: 08/23/2024]
Abstract
Objective.Penalty parameters in penalized likelihood positron emission tomography (PET) reconstruction are typically determined empirically. The cross-validation log-likelihood (CVLL) method has been introduced to optimize these parameters by maximizing a CVLL function, which assesses the likelihood of reconstructed images using one subset of a list-mode dataset based on another subset. This study aims to validate the efficacy of the CVLL method in whole-body imaging for cancer patients using a conventional clinical PET scanner.Approach.Fifteen lung cancer patients were injected with 243.7 ± 23.8 MBq of [18F]FDG and underwent a 22 min PET scan on a Biograph mCT PET/CT scanner, starting at 60 ± 5 min post-injection. The PET list-mode data were partitioned by subsampling without replacement, with 20 minutes of data for image reconstruction using an in-house ordered subset expectation maximization algorithm and the remaining 2 minutes of data for cross-validation. Two penalty parameters, penalty strengthβand Fair penalty function parameterδ, were subjected to optimization. Whole-body images were reconstructed, and CVLL values were computed across various penalty parameter combinations. The optimal image corresponding to the maximum CVLL value was selected by a grid search for each patient.Main results.Theδvalue required to maximize the CVLL value was notably small (⩽10-6in this study). The influences of voxel size and scan duration on image optimization were investigated. A correlation analysis revealed a significant inverse relationship between optimalβand scan count level, with a correlation coefficient of -0.68 (p-value = 3.5 × 10-5). The optimal images selected by the CVLL method were compared with those chosen by two radiologists based on their diagnostic preferences. Differences were observed in the selection of optimal images.Significance.This study demonstrates the feasibility of incorporating the CVLL method into routine imaging protocols, potentially allowing for a wide range of combinations of injected radioactivity amounts and scan durations in modern PET imaging.
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Affiliation(s)
- Qian Wang
- Department of Biomedical Engineering, University of California, Davis, CA, United States of America
- Department of Radiology, University of California, Davis, CA, United States of America
| | - Yasser G Abdelhafez
- Department of Radiology, University of California, Davis, CA, United States of America
- Department of Radiotherapy and Nuclear Medicine, South Egypt Cancer Institute, Assiut University, Assiut, Egypt
| | - Hande Nalbant
- Department of Radiology, University of California, Davis, CA, United States of America
| | - Benjamin A Spencer
- Department of Biomedical Engineering, University of California, Davis, CA, United States of America
- Department of Radiology, University of California, Davis, CA, United States of America
| | - Reimund Bayerlein
- Department of Biomedical Engineering, University of California, Davis, CA, United States of America
- Department of Radiology, University of California, Davis, CA, United States of America
| | - Jinyi Qi
- Department of Biomedical Engineering, University of California, Davis, CA, United States of America
| | - Simon R Cherry
- Department of Biomedical Engineering, University of California, Davis, CA, United States of America
- Department of Radiology, University of California, Davis, CA, United States of America
| | - Lorenzo Nardo
- Department of Radiology, University of California, Davis, CA, United States of America
| | - Ramsey D Badawi
- Department of Biomedical Engineering, University of California, Davis, CA, United States of America
- Department of Radiology, University of California, Davis, CA, United States of America
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Roya M, van Snick JH, Slart RHJA, Noordzij W, Stormezand GN, Willemsen ATM, Boellaard R, Glaudemans AWJM, Tsoumpas C, van Sluis J. Clinical Performance Comparison of a Long Versus a Short Axial Field-of-View PET/CT Using EARL-Compliant Reconstructions. Mol Imaging Biol 2024:10.1007/s11307-024-01939-5. [PMID: 39093483 DOI: 10.1007/s11307-024-01939-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 06/13/2024] [Accepted: 07/22/2024] [Indexed: 08/04/2024]
Abstract
PURPOSE To ensure comparable PET/CT image quality between or within centres, clinical inter-system performance comparisons following European Association of Nuclear Medicine Research Ltd. (EARL) guidelines is required. In this work the performance of the long axial field-of-view Biograph Vision Quadra is compared to its predecessor, the short axial field-of-view Biograph Vision. PROCEDURES To this aim, patients with suspected tumour lesions received a single weight-based (3 MBq/kg) 2-deoxy-2-[18F]fluoro-D-glucose injection and underwent routine clinical ( ∼ 15 min) scans on the Vision and 3-min scans on the Quadra in listmode in balanced order. Image quality (IQ), image noise (IN), and tumour demarcation (TD) were assessed visually by four nuclear medicine physicians using a 5-point Likert scale and semiquantitative analysis was performed using standardised uptake values (SUVs). Inter-reader agreement was tested using Wilcoxon's signed rank test and the SUVs were statistically compared using a paired t-test. RESULTS Twenty patients (mean age, 60 years ± 8.8 [standard deviation], 16 male) were enrolled. Inter-reader agreement ranged from good to very good for IQ and IN (0.62 ≤ W ≤ 0.81), and fair for TD (0.29 ≤ W ≤ 0.39). Furthermore, a significant difference was found for TD (p = 0.015) between the systems, showing improved TD for the Quadra. CONCLUSION This study demonstrates that the Quadra can be used in routine clinical practice with multiple PET/CT systems or in multicentre studies. This system provides comparable diagnostic image quality and semiquantitative accuracy, improved TD, and has the advantage of shorter scan durations.
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Affiliation(s)
- Mostafa Roya
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.
| | - Johannes H van Snick
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Riemer H J A Slart
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
- Department of Biomedical Photonic Imaging, Faculty of Science and Technology, University of Twente, Enchede, The Netherlands
| | - Walter Noordzij
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Gilles N Stormezand
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Antoon T M Willemsen
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Ronald Boellaard
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
- Department of Radiology and Nuclear Medicine, Free University of Amsterdam, University Medical Centers Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Andor W J M Glaudemans
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Charalampos Tsoumpas
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Joyce van Sluis
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
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Bayerlein R, Swarnakar V, Selfridge A, Spencer BA, Nardo L, Badawi RD. Cloud-based serverless computing enables accelerated monte carlo simulations for nuclear medicine imaging. Biomed Phys Eng Express 2024; 10:10.1088/2057-1976/ad5847. [PMID: 38876087 PMCID: PMC11254166 DOI: 10.1088/2057-1976/ad5847] [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: 01/29/2024] [Accepted: 06/14/2024] [Indexed: 06/16/2024]
Abstract
Objective.This study investigates the potential of cloud-based serverless computing to accelerate Monte Carlo (MC) simulations for nuclear medicine imaging tasks. MC simulations can pose a high computational burden-even when executed on modern multi-core computing servers. Cloud computing allows simulation tasks to be highly parallelized and considerably accelerated.Approach.We investigate the computational performance of a cloud-based serverless MC simulation of radioactive decays for positron emission tomography imaging using Amazon Web Service (AWS) Lambda serverless computing platform for the first time in scientific literature. We provide a comparison of the computational performance of AWS to a modern on-premises multi-thread reconstruction server by measuring the execution times of the processes using between105and2·1010simulated decays. We deployed two popular MC simulation frameworks-SimSET and GATE-within the AWS computing environment. Containerized application images were used as a basis for an AWS Lambda function, and local (non-cloud) scripts were used to orchestrate the deployment of simulations. The task was broken down into smaller parallel runs, and launched on concurrently running AWS Lambda instances, and the results were postprocessed and downloaded via the Simple Storage Service.Main results.Our implementation of cloud-based MC simulations with SimSET outperforms local server-based computations by more than an order of magnitude. However, the GATE implementation creates more and larger output file sizes and reveals that the internet connection speed can become the primary bottleneck for data transfers. Simulating 109decays using SimSET is possible within 5 min and accrues computation costs of about $10 on AWS, whereas GATE would have to run in batches for more than 100 min at considerably higher costs.Significance.Adopting cloud-based serverless computing architecture in medical imaging research facilities can considerably improve processing times and overall workflow efficiency, with future research exploring additional enhancements through optimized configurations and computational methods.
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Affiliation(s)
- Reimund Bayerlein
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Vivek Swarnakar
- Department of Radiology, University of California Davis, Davis, CA, USA
| | - Aaron Selfridge
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Benjamin A Spencer
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
- Department of Radiology, University of California Davis, Davis, CA, USA
| | - Lorenzo Nardo
- Department of Radiology, University of California Davis, Davis, CA, USA
| | - Ramsey D Badawi
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
- Department of Radiology, University of California Davis, Davis, CA, USA
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Bayerlein R, Spencer BA, Leung EK, Omidvari N, Abdelhafez YG, Wang Q, Nardo L, Cherry SR, Badawi RD. Development of a Monte Carlo-based scatter correction method for total-body PET using the uEXPLORER PET/CT scanner. Phys Med Biol 2024; 69:045033. [PMID: 38266297 DOI: 10.1088/1361-6560/ad2230] [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: 09/25/2023] [Accepted: 01/24/2024] [Indexed: 01/26/2024]
Abstract
Objective.This study presents and evaluates a robust Monte Carlo-based scatter correction (SC) method for long axial field of view (FOV) and total-body positron emission tomography (PET) using the uEXPLORER total-body PET/CT scanner.Approach.Our algorithm utilizes the Monte Carlo (MC) tool SimSET to compute SC factors in between individual image reconstruction iterations within our in-house list-mode and time-of-flight-based image reconstruction framework. We also introduced a unique scatter scaling technique at the detector block-level for optimal estimation of the scatter contribution in each line of response. First image evaluations were derived from phantom data spanning the entire axial FOV along with image data from a human subject with a large body mass index. Data was evaluated based on qualitative inspections, and contrast recovery, background variability, residual scatter removal from cold regions, biases and axial uniformity were quantified and compared to non-scatter-corrected images.Main results.All reconstructed images demonstrated qualitative and quantitative improvements compared to non-scatter-corrected images: contrast recovery coefficients improved by up to 17.2% and background variability was reduced by up to 34.3%, and the residual lung error was between 1.26% and 2.08%. Low biases throughout the axial FOV indicate high quantitative accuracy and axial uniformity of the corrections. Up to 99% of residual activity in cold areas in the human subject was removed, and the reliability of the method was demonstrated in challenging body regions like in the proximity of a highly attenuating knee prosthesis.Significance.The MC SC method employed was demonstrated to be accurate and robust in TB-PET. The results of this study can serve as a benchmark for optimizing the quantitative performance of future SC techniques.
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Affiliation(s)
- Reimund Bayerlein
- Departments of Radiology and Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
| | - Benjamin A Spencer
- Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
| | | | - Negar Omidvari
- Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
| | - Yasser G Abdelhafez
- Departments of Radiology and Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
| | - Qian Wang
- Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
| | - Lorenzo Nardo
- Departments of Radiology and Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
| | - Simon R Cherry
- Departments of Radiology and Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
- Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
| | - Ramsey D Badawi
- Departments of Radiology and Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
- Biomedical Engineering, University of California-Davis, Davis, CA, United States of America
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Qi C, Sui X, Yu H, Wang S, Hu Y, Sun H, Yang X, Wang Y, Zhou Y, Shi H. Phantom study and clinical application of total-body 18F-FDG PET/CT imaging: How to use small voxel imaging better? EJNMMI Phys 2024; 11:17. [PMID: 38358541 PMCID: PMC10869323 DOI: 10.1186/s40658-023-00597-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 11/28/2023] [Indexed: 02/16/2024] Open
Abstract
BACKGROUND Conventional PET/CT imaging reconstruction is typically performed using voxel size of 3.0-4.0 mm in three axes. It is hypothesized that a smaller voxel sizes could improve the accuracy of small lesion detection. This study aims to explore the advantages and conditions of small voxel imaging on clinical application. METHODS Both NEMA IQ phantom and 30 patients with an injected dose of 3.7 MBq/kg were scanned using a total-body PET/CT (uEXPLORER). Images were reconstructed using matrices of 192 × 192, 512 × 512, and 1024 × 1024 with scanning duration of 3 min, 5 min, 8 min, and 10 min, respectively. RESULTS In the phantom study, the contrast recovery coefficient reached the maximum in matrix group of 512 × 512, and background variability increased as voxel size decreased. In the clinical study, SUVmax, SD, and TLR increased, while SNR decreased as the voxel size decreased. When the scanning duration increased, SNR increased, while SUVmax, SD, and TLR decreased. The SUVmean was more reluctant to the changes in imaging matrix and scanning duration. The mean subjective scores for all 512 × 512 groups and 1024 × 1024 groups (scanning duration ≥ 8 min) were over three points. One false-positive lesion was found in groups of 512 × 512 with scanning duration of 3 min, 1024 × 1024 with 3 min and 5 min, respectively. Meanwhile, the false-negative lesions found in group of 192 × 192 with duration of 3 min and 5 min, 512 × 512 with 3 min and 1024 × 1024 with 3 min and 5 min were 5, 4, 1, 4, and 1, respectively. The reconstruction time and storage space occupation were significantly increased as the imaging matrix increased. CONCLUSIONS PET/CT imaging with smaller voxel can improve SUVmax and TLR of lesions, which is advantageous for the diagnosis of small or hypometabolic lesions if with sufficient counts. With an 18F-FDG injection dose of 3.7 MBq/kg, uEXPLORER PET/CT imaging using matrix of 512 × 512 with 5 min or 1024 × 1024 with 8 min can meet the image requirements for clinical use.
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Affiliation(s)
- Chi Qi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, No. 180 in Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, People's Republic of China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, People's Republic of China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, People's Republic of China
- Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, 646000, People's Republic of China
| | - Xiuli Sui
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, No. 180 in Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, People's Republic of China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, People's Republic of China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, People's Republic of China
| | - Haojun Yu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, No. 180 in Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, People's Republic of China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, People's Republic of China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, People's Republic of China
| | - Siyang Wang
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, No. 180 in Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, People's Republic of China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, People's Republic of China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, People's Republic of China
| | - Yan Hu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, No. 180 in Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, People's Republic of China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, People's Republic of China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, People's Republic of China
| | - Hongyan Sun
- Central Research Institute, United Imaging Healthcare Group Co, Ltd, Shanghai, People's Republic of China
| | - Xinlan Yang
- Central Research Institute, United Imaging Healthcare Group Co, Ltd, Shanghai, People's Republic of China
| | - Yihan Wang
- Central Research Institute, United Imaging Healthcare Group Co, Ltd, Shanghai, People's Republic of China
| | - Yun Zhou
- Central Research Institute, United Imaging Healthcare Group Co, Ltd, Shanghai, People's Republic of China
| | - Hongcheng Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, No. 180 in Fenglin Road, Shanghai, 200032, People's Republic of China.
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, People's Republic of China.
- Shanghai Institute of Medical Imaging, Shanghai, 200032, People's Republic of China.
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, People's Republic of China.
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Kaviani S, Sanaat A, Mokri M, Cohalan C, Carrier JF. Image reconstruction using UNET-transformer network for fast and low-dose PET scans. Comput Med Imaging Graph 2023; 110:102315. [PMID: 38006648 DOI: 10.1016/j.compmedimag.2023.102315] [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: 06/07/2023] [Revised: 09/26/2023] [Accepted: 11/15/2023] [Indexed: 11/27/2023]
Abstract
INTRODUCTION Low-dose and fast PET imaging (low-count PET) play a significant role in enhancing patient safety, healthcare efficiency, and patient comfort during medical imaging procedures. To achieve high-quality images with low-count PET scans, effective reconstruction models are crucial for denoising and enhancing image quality. The main goal of this paper is to develop an effective and accurate deep learning-based method for reconstructing low-count PET images, which is a challenging problem due to the limited amount of available data and the high level of noise in the acquired images. The proposed method aims to improve the quality of reconstructed PET images while preserving important features, such as edges and small details, by combining the strengths of UNET and Transformer networks. MATERIAL AND METHODS The proposed TrUNET-MAPEM model integrates a residual UNET-transformer regularizer into the unrolled maximum a posteriori expectation maximization (MAPEM) algorithm for PET image reconstruction. A loss function based on a combination of structural similarity index (SSIM) and mean squared error (MSE) is utilized to evaluate the accuracy of the reconstructed images. The simulated dataset was generated using the Brainweb phantom, while the real patient dataset was acquired using a Siemens Biograph mMR PET scanner. We also implemented state-of-the-art methods for comparison purposes: OSEM, MAPOSEM, and supervised learning using 3D-UNET network. The reconstructed images are compared to ground truth images using metrics such as peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), and relative root mean square error (rRMSE) to quantitatively evaluate the accuracy of the reconstructed images. RESULTS Our proposed TrUNET-MAPEM approach was evaluated using both simulated and real patient data. For the patient data, our model achieved an average PSNR of 33.72 dB, an average SSIM of 0.955, and an average rRMSE of 0.39. These results outperformed other methods which had average PSNRs of 36.89 dB, 34.12 dB, and 33.52 db, average SSIMs of 0.944, 0.947, and 0.951, and average rRMSEs of 0.59, 0.49, and 0.42. For the simulated data, our model achieved an average PSNR of 31.23 dB, an average SSIM of 0.95, and an average rRMSE of 0.55. These results also outperformed other state-of-the-art methods, such as OSEM, MAPOSEM, and 3DUNET-MAPEM. The model demonstrates the potential for clinical use by successfully reconstructing smooth images while preserving edges. The comparison with other methods demonstrates the superiority of our approach, as it outperforms all other methods for all three metrics. CONCLUSION The proposed TrUNET-MAPEM model presents a significant advancement in the field of low-count PET image reconstruction. The results demonstrate the potential for clinical use, as the model can produce images with reduced noise levels and better edge preservation compared to other reconstruction and post-processing algorithms. The proposed approach may have important clinical applications in the early detection and diagnosis of various diseases.
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Affiliation(s)
- Sanaz Kaviani
- Faculty of Medicine, University of Montreal, Montreal, Canada; University of Montreal Hospital Research Centre (CRCHUM), Montreal, Canada.
| | - Amirhossein Sanaat
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva, Switzerland
| | - Mersede Mokri
- Faculty of Medicine, University of Montreal, Montreal, Canada; University of Montreal Hospital Research Centre (CRCHUM), Montreal, Canada
| | - Claire Cohalan
- University of Montreal Hospital Research Centre (CRCHUM), Montreal, Canada; Department of Physics and Biomedical Engineering, University of Montreal Hospital Centre, Montreal, Canada
| | - Jean-Francois Carrier
- University of Montreal Hospital Research Centre (CRCHUM), Montreal, Canada; Department of Physics, University of Montreal, Montreal, QC, Canada; Department de Radiation Oncology, University of Montreal Hospital Centre (CHUM), Montreal, Canada
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Wang Y, Chen Z, Zhu Y, Zhao H, Li L, Huang G, Xue W, Chen R, Liu J. Total-body [ 68 Ga]Ga-PSMA-11 PET/CT improves detection rate compared with conventional [ 68 Ga]Ga-PSMA-11 PET/CT in patients with biochemical recurrent prostate cancer. Eur J Nucl Med Mol Imaging 2023; 50:4096-4106. [PMID: 37578502 DOI: 10.1007/s00259-023-06355-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 07/22/2023] [Indexed: 08/15/2023]
Abstract
PURPOSE The purpose of this study was to assess whether total-body [68 Ga]Ga-PSMA-11 PET/CT could improve the detection rate compared with conventional [68 Ga]Ga-PSMA-11 PET/CT in patients with biochemical recurrent prostate cancer. METHODS Two hundred biochemical recurrent prostate cancer patients with similar clinicopathological characteristics were included, of whom 100 patients underwent early total-body [68 Ga]Ga-PSMA-11 PET/CT and diuretic-delayed total-body [68 Ga]Ga-PSMA-11 PET/CT, and the other 100 patients received early conventional [68 Ga]Ga-PSMA-11 PET/CT and diuretic-delayed conventional [68 Ga]Ga-PSMA-11 PET/CT. The detection rates of total-body [68 Ga]Ga-PSMA-11 PET/CT and conventional [68 Ga]Ga-PSMA-11 PET/CT were compared using a chi-square test and stratified analysis. The image quality of total-body [68 Ga]Ga-PSMA PET/CT and conventional [68 Ga]Ga-PSMA-11 PET/CT was compared based on subjective scoring and objective parameters. Subjective scoring was conducted from background noise and lesion prominence using a 5-point scale. Objective parameters were evaluated by SUVmax, SUVmean, the standard deviation (SD) of SUV, and the signal-to-noise ratio (SNR) of liver and gluteus maximus. The SUVmax of the recurrent lesions was also measured. RESULTS The liver SD of the total-body [68 Ga]Ga-PSMA-11 PET/CT was significantly lower than that of conventional [68 Ga]Ga-PSMA-11 PET/CT, the SNR was significantly higher than that of conventional [68 Ga]Ga-PSMA-11 PET/CT, and the subjective evaluation was significantly better than that of conventional [68 Ga]Ga-PSMA-11 PET/CT. The detection rate of total-body [68 Ga]Ga-PSMA PET/CT for biochemical recurrence of prostate cancer was significantly higher than that of conventional [68 Ga]Ga-PSMA-11 PET/CT (91.0% vs. 74.0%, P = 0.003). Total-body [68 Ga]Ga-PSMA-11 PET/CT had better detection efficiency for patients with a Gleason score ≤ 8 or PSA ≤ 2 ng/ml. The advantages of diuretic-delayed total-body [68 Ga]Ga-PSMA-11 PET/CT were more obvious. CONCLUSION Total-body [68 Ga]Ga-PSMA-11 PET/CT could significantly improve the detection rate compared with conventional [68 Ga]Ga-PSMA-11 PET/CT in patients with biochemical recurrent prostate cancer.
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Affiliation(s)
- Yining Wang
- Department of Nuclear Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China
| | - Zijun Chen
- Department of Nuclear Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China
| | - Yinjie Zhu
- Department of Urology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China
| | - Haitao Zhao
- Department of Nuclear Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China
| | - Lianghua Li
- Department of Nuclear Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China
| | - Gang Huang
- Department of Nuclear Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China
| | - Wei Xue
- Department of Urology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China
| | - Ruohua Chen
- Department of Nuclear Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Jianjun Liu
- Department of Nuclear Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
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Puri T, Frost ML, Moore AEB, Choudhury A, Vinjamuri S, Mahajan A, Fynbo C, Vrist M, Theil J, Kairemo K, Wong J, Zaidi H, Revheim ME, Werner TJ, Alavi A, Cook GJR, Blake GM. Utility of a simplified [ 18F] sodium fluoride PET imaging method to quantify bone metabolic flux for a wide range of clinical applications. Front Endocrinol (Lausanne) 2023; 14:1236881. [PMID: 37780613 PMCID: PMC10534005 DOI: 10.3389/fendo.2023.1236881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 08/14/2023] [Indexed: 10/03/2023] Open
Abstract
We review the rationale, methodology, and clinical utility of quantitative [18F] sodium fluoride ([18F]NaF) positron emission tomography-computed tomography (PET-CT) imaging to measure bone metabolic flux (Ki, also known as bone plasma clearance), a measurement indicative of the local rate of bone formation at the chosen region of interest. We review the bone remodelling cycle and explain what aspects of bone remodelling are addressed by [18F]NaF PET-CT. We explain how the technique works, what measurements are involved, and what makes [18F]NaF PET-CT a useful tool for the study of bone remodelling. We discuss how these measurements can be simplified without loss of accuracy to make the technique more accessible. Finally, we briefly review some key clinical applications and discuss the potential for future developments. We hope that the simplified method described here will assist in promoting the wider use of the technique.
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Affiliation(s)
- Tanuj Puri
- Faculty of Biology, Medicine and Health, School of Medical Sciences, Division of Cancer Sciences, The University of Manchester, The Christie NHS Foundation Trust, Manchester, United Kingdom
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King’s College London, St. Thomas’ Hospital, London, United Kingdom
| | - Michelle L. Frost
- Institute of Cancer Research Clinical Trials & Statistics Unit (ICR-CTSU), The Institute of Cancer Research, Sutton, United Kingdom
| | - Amelia E. B. Moore
- Department of Cancer Imaging, and King’s College London and Guy’s and St Thomas’ PET Centre, School of Biomedical Engineering and Imaging Sciences, King’s College London, St. Thomas’ Hospital, London, United Kingdom
| | - Ananya Choudhury
- Faculty of Biology, Medicine and Health, School of Medical Sciences, Division of Cancer Sciences, The University of Manchester, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Sobhan Vinjamuri
- Nuclear Medicine Department, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool, United Kingdom
| | - Abhishek Mahajan
- The Clatterbridge Cancer Centre NHS Foundation Trust, University of Liverpool, Liverpool, United Kingdom
| | - Claire Fynbo
- Clinic of Nuclear Medicine, Gødstrup Hospital, Herning, Denmark
| | - Marie Vrist
- University Clinic in Nephrology and Hypertension, Gødstrup Hospital, Herning, Denmark
| | - Jørn Theil
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Kalevi Kairemo
- Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - James Wong
- Department of Anaesthesia, St Bartholomew’s Hospital, Barts Health NHS Trust, London, United Kingdom
| | - Habib Zaidi
- Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva, Switzerland
| | - Mona-Elisabeth Revheim
- The Intervention Centre, Oslo University Hospital, Norway Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Thomas J. Werner
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Abass Alavi
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Gary J. R. Cook
- Department of Cancer Imaging, and King’s College London and Guy’s and St Thomas’ PET Centre, School of Biomedical Engineering and Imaging Sciences, King’s College London, St. Thomas’ Hospital, London, United Kingdom
| | - Glen M. Blake
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King’s College London, St. Thomas’ Hospital, London, United Kingdom
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Hu H, Huang Y, Sun H, Zhou K, Jiang L, Zhong J, Chen L, Wang L, Han Y, Wu H. A proper protocol for routine 18F-FDG uEXPLORER total-body PET/CT scans. EJNMMI Phys 2023; 10:51. [PMID: 37695324 PMCID: PMC10495295 DOI: 10.1186/s40658-023-00573-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 08/08/2023] [Indexed: 09/12/2023] Open
Abstract
BACKGROUND Conventional clinical PET scanners typically have an axial field of view (AFOV) of 15-30 cm, resulting in limited coverage and relatively low photon detection efficiency. Taking advantage of the development of long-axial PET/CT, the uEXPLORER PET/CT scanner with an axial coverage of 194 cm increases the effective count rate by approximately 40 times compared to that of conventional PET scanners. Ordered subset expectation maximization (OSEM) is the most widely used iterative algorithm in PET. The major drawback of OSEM is that the iteration process must be stopped before convergence to avoid image degradation due to excessive noise. A new Bayesian penalized-likelihood iterative PET reconstruction, named HYPER iterative, was developed and is now available on the uEXPLORER total-body PET/CT, which incorporates a noise control component by using a penalty function in each iteration and finds the maximum likelihood solution through repeated iterations. To date, its impact on lesion visibility in patients with a full injected dose or half injected dose is unclear. The goal of this study was to determine a proper protocol for routine 18F-FDG uEXPLORER total-body PET/CT scans. RESULTS The uEXPLORER total-body PET/CT images reconstructed using both OSEM and HYPER iterative algorithms of 20 tumour patients were retrospectively reviewed. The quality of the 5 min PET image was excellent (score 5) for all of the dose and reconstruction methods. Using the HYPER iterative method, the PET images reached excellent quality at 1 min with full-dose PET and at 2 min with half-dose PET. The PET image reached a similar excellent quality at 2 min with a full dose and at 3 min with a half dose using OSEM. The noise in the OSEM reconstruction was higher than that in the HYPER iterative. Compared to OSEM, the HYPER iterative had a slightly higher SUVmax and TBR of the lesions for large positive lesions (≥ 2 cm) (SUVmax: up to 9.03% higher in full dose and up to 12.52% higher in half dose; TBR: up to 8.69% higher in full dose and up to 23.39% higher in half dose). For small positive lesions (≤ 10 mm), the HYPER iterative had an obviously higher SUVmax and TBR of the lesions (SUVmax: up to 45.21% higher in full dose and up to 74.96% higher in half dose; TBR: up to 44.91% higher in full dose and up to 93.73% higher in half dose). CONCLUSIONS A 1 min scan with a full dose and a 2 min scan with a half dose are optimal for clinical diagnosis using the HYPER iterative and 2 min and 3 min for OSEM. For quantification of the small lesions, HYPER iterative reconstruction is preferred.
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Affiliation(s)
- Huiran Hu
- Nanfang PET Center, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong Province, People's Republic of China
| | - Yanchao Huang
- Nanfang PET Center, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong Province, People's Republic of China
| | - Hongyan Sun
- United Imaging Healthcare, Shanghai, People's Republic of China
| | - Kemin Zhou
- Nanfang PET Center, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong Province, People's Republic of China
| | - Li Jiang
- Nanfang PET Center, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong Province, People's Republic of China
| | - Jinmei Zhong
- Nanfang PET Center, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong Province, People's Republic of China
| | - Li Chen
- Nanfang PET Center, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong Province, People's Republic of China
| | - Lijuan Wang
- Nanfang PET Center, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong Province, People's Republic of China
| | - Yanjiang Han
- Nanfang PET Center, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong Province, People's Republic of China.
| | - Hubing Wu
- Nanfang PET Center, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong Province, People's Republic of China.
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10
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Yu X, Sun H, Xu L, Han Y, Wang C, Li L, Ng YL, Shi F, Qiu J, Huang G, Zhou Y, Chen Y, Liu J. Improved accuracy of the biodistribution and internal radiation dosimetry of 13 N-ammonia using a total-body PET/CT scanner. Med Phys 2023; 50:5865-5874. [PMID: 37177847 DOI: 10.1002/mp.16450] [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: 07/05/2022] [Revised: 04/23/2023] [Accepted: 04/23/2023] [Indexed: 05/15/2023] Open
Abstract
BACKGROUND Conventional short-axis PET typically utilizes multi-bed multi-pass acquisition to produce quantitative whole-body dynamic images and cannot record all the uptake information simultaneously, resulting in errors when fitting the time-activity curves (TACs) and calculating radiation doses. PURPOSE The aim of this study is to evaluate the 13 N-ammonia biodistribution and the internal radiation doses using a 194 cm long total-body PET/CT scanner (uEXPLORER), and make a comparison with the previous short-axis PET results. METHODS Ten subjects (age 40-74 years) received 13 N-NH3 injection (418.1-670.81 MBq) and were under a dynamic scan for about 60 min with using a 3-dimensional whole-body protocol. ROIs were drawn visually on 11 major organs (brain, thyroid, gallbladder, heart wall, kidneys, liver, pancreas, spleen, lungs, bone marrow, and urinary bladder content) for each subject. TACs were generated using Pmod and the absorbed radiation doses were calculated using Olinda 2.2. To compare with the conventional PET/CT, five points were sampled on uEXPLORER's TACs to mimic the result of a short-axis PET/CT (15 cm axial FOV, consisted of 9 or 10 bed positions). Then the TACs were obtained using the multi-exponential fitting method, and the residence time and radiation dose were also calculated and compared with uEXPLORER. RESULTS The highest absorbed organ doses were the pancreas, thyroid, spleen, heart wall, and kidneys for the male. For the female, the first five highest absorbed organ dose coefficients were the pancreas, heart wall, spleen, lungs, and kidneys. The lowest absorbed dose was found in red marrow both for male and female. The simulated short-axis PET can fit TACs well for the gradually-changed uptake organs but typically underestimated for the rapid-uptake organs during the first-10 min, resulting in errors in the calculated radiation dose. CONCLUSION uEXPLORER PET/CT can measure 13 N-ammonia's TACs simultaneously in all organs of the whole body, which can provide more accurate biodistribution and radiation dose estimation compared with the conventional short-axis scanners.
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Affiliation(s)
- Xiaofeng Yu
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Hongyan Sun
- Central Research Institute, United Imaging Healthcare, Shanghai, People's Republic of China
| | - Lian Xu
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Yuan Han
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Cheng Wang
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Lianghua Li
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Yee Ling Ng
- Central Research Institute, United Imaging Healthcare, Shanghai, People's Republic of China
| | - Fuxiao Shi
- Central Research Institute, United Imaging Healthcare, Shanghai, People's Republic of China
| | - Ju Qiu
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Gang Huang
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Yun Zhou
- Central Research Institute, United Imaging Healthcare, Shanghai, People's Republic of China
| | - Yumei Chen
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Jianjun Liu
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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11
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Li L, Wan L, Zhao H, Wang C, Wei W, Liu J. Biodistribution and radiation dosimetry of multiple tracers on total-body positron emission tomography/computed tomography. Quant Imaging Med Surg 2023; 13:5182-5194. [PMID: 37581077 PMCID: PMC10423372 DOI: 10.21037/qims-22-1418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 06/05/2023] [Indexed: 08/16/2023]
Abstract
Background [18F]F-FDG, [68Ga]Ga-PSMA-11, and [68Ga]Ga-FAPI-04 have achieved good results in multiple clinical trials and clinical practice, but the imaging of these tracers is limited to traditional short-axis positron emission tomography/computed tomography (PET/CT). Therefore, we aimed to use total-body PET/CT dynamic scanning to describe whole-body biodistribution of these three tracers and to calculate more precise radiation doses. Methods Total-body PET/CT (uExplorer, United Imaging Healthcare) dynamic scanning was performed on 54 patients, including 30 patients with [18F]F-FDG, 10 patients with [68Ga]Ga-PSMA-11, and 14 patients with [68Ga]Ga-FAPI-04. A 60-minute dynamic scanning of whole body was performed simultaneously after bedside bolus injection of the corresponding tracers. The dynamic sequence of 92 frames was quantitatively analyzed by the Pmod4.0 software. Whole body biodistribution was calculated as time-activity curves (TACs) describing dynamic uptake patterns in the subject's major organs, followed by calculation of tracer kinetics and cumulative organ activity. Finally, combined with the OLINDA/EXM software, effective doses of the different tracers and individual organ doses were calculated. Results In a systematic TAC analysis of three tracers, we identified distinct biodistribution patterns in major organs. [68Ga]Ga-PSMA-11 showed a trend of rapid increasing and slow decreasing in liver, spleen, muscle, and bone. In the heart, stomach, brain, and lung, tracer decreased rapidly after rapid increasing. Similarly, tracer uptake in the kidney and urinary bladder increased gradually. [68Ga]Ga-FAPI-04 showed a rapid increasing and rapid decreasing trend in brain, lung, liver, spleen, bone, heart, kidney, and stomach. The mean effective dose of [68Ga]Ga-PSMA-11 was 1.47E-02 mSv/MBq, and the mean effective doses of [18F]F-FDG and [68Ga]Ga-FAPI-04 were comparable (2.52E-02 mSv/MBq and 2.23E-02 mSv/MBq). The mean effective dose of [18F]F-FDG was lower than that reported in the literature measured by previous short-axis PET, while both [68Ga]Ga-PSMA-11 and [68Ga]Ga-FAPI-04 had higher value than previously reported value. Conclusions [18F]F-FDG, [68Ga]Ga-PSMA-11 and [68Ga]Ga-FAPI-04 have good biodistribution in human organs. Real-time high-sensitivity dynamic scanning with total-body PET/CT is a very effective way to accurately calculate biodistribution and effective dose of positron-labeled radiopharmaceuticals.
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Affiliation(s)
- Lianghua Li
- Department of Nuclear Medicine, Institute of Clinical Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Liangrong Wan
- Department of Nuclear Medicine, Institute of Clinical Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Haitao Zhao
- Department of Nuclear Medicine, Institute of Clinical Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Cheng Wang
- Department of Nuclear Medicine, Institute of Clinical Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Weijun Wei
- Department of Nuclear Medicine, Institute of Clinical Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jianjun Liu
- Department of Nuclear Medicine, Institute of Clinical Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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12
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Li Y, Wang J, Hu J, Jia J, Sun H, Zhao Y, Hu Y. PET/CT scan without sedation: how to use total-body PET/CT to salvage child's involuntary movement? Eur J Nucl Med Mol Imaging 2023; 50:2912-2913. [PMID: 36973518 DOI: 10.1007/s00259-023-06208-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 03/18/2023] [Indexed: 03/29/2023]
Affiliation(s)
- Yongjiang Li
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China
- Department of Nuclear Medicine, Sun Yat-Sen University Cancer Center, No.651 Dongfeng East Road, Guangzhou, Guangdong, China
| | - Juan Wang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China
- Department of Pediatric Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - Junfeng Hu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China
- Department of Nuclear Medicine, Sun Yat-Sen University Cancer Center, No.651 Dongfeng East Road, Guangzhou, Guangdong, China
| | - Jin Jia
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China
- Department of Nuclear Medicine, Sun Yat-Sen University Cancer Center, No.651 Dongfeng East Road, Guangzhou, Guangdong, China
| | - Hongyan Sun
- Central Research Institute, United Imaging Healthcare Group Co, Ltd, Shanghai, China
| | - Yumo Zhao
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China
- Department of Nuclear Medicine, Sun Yat-Sen University Cancer Center, No.651 Dongfeng East Road, Guangzhou, Guangdong, China
| | - Yingying Hu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China.
- Department of Nuclear Medicine, Sun Yat-Sen University Cancer Center, No.651 Dongfeng East Road, Guangzhou, Guangdong, China.
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13
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Sohn JH, Behr SC, Hernandez PM, Seo Y. Quantitative Assessment of Myocardial Ischemia With Positron Emission Tomography. J Thorac Imaging 2023; 38:247-259. [PMID: 33492046 PMCID: PMC8295411 DOI: 10.1097/rti.0000000000000579] [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: 11/26/2022]
Abstract
Recent advances in positron emission tomography (PET) technology and reconstruction techniques have now made quantitative assessment using cardiac PET readily available in most cardiac PET imaging centers. Multiple PET myocardial perfusion imaging (MPI) radiopharmaceuticals are available for quantitative examination of myocardial ischemia, with each having distinct convenience and accuracy profile. Important properties of these radiopharmaceuticals ( 15 O-water, 13 N-ammonia, 82 Rb, 11 C-acetate, and 18 F-flurpiridaz) including radionuclide half-life, mean positron range in tissue, and the relationship between kinetic parameters and myocardial blood flow (MBF) are presented. Absolute quantification of MBF requires PET MPI to be performed with protocols that allow the generation of dynamic multiframes of reconstructed data. Using a tissue compartment model, the rate constant that governs the rate of PET MPI radiopharmaceutical extraction from the blood plasma to myocardial tissue is calculated. Then, this rate constant ( K1 ) is converted to MBF using an established extraction formula for each radiopharmaceutical. As most of the modern PET scanners acquire the data only in list mode, techniques of processing the list-mode data into dynamic multiframes are also reviewed. Finally, the impact of modern PET technologies such as PET/CT, PET/MR, total-body PET, machine learning/deep learning on comprehensive and quantitative assessment of myocardial ischemia is briefly described in this review.
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Affiliation(s)
- Jae Ho Sohn
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA
| | - Spencer C. Behr
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA
| | | | - Youngho Seo
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA
- Department of Radiation Oncology, University of California, San Francisco, CA
- UC Berkeley-UCSF Graduate Program in Bioengineering, Berkeley and San Francisco, CA
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14
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Mingels C, Weidner S, Sari H, Buesser D, Zeimpekis K, Shi K, Alberts I, Rominger A. Impact of the new ultra-high sensitivity mode in a long axial field-of-view PET/CT. Ann Nucl Med 2023; 37:310-315. [PMID: 36913094 PMCID: PMC10129991 DOI: 10.1007/s12149-023-01827-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 02/14/2023] [Indexed: 03/14/2023]
Abstract
OBJECTIVE Long axial field-of-view (LAFOV) PET/CT showed improved performance resulting from higher sensitivity. The aim was to quantify the impact of using the full acceptance angle (UHS) in image reconstructions with the Biograph Vision Quadra LAFOV PET/CT (Siemens Healthineers) compared to the limited acceptance angle (high sensitivity mode, HS). METHODS 38 oncological patients examined on a LAFOV Biograph Vision Quadra PET/CT were analysed. 15 patients underwent [18F]FDG-PET/CT, 15 patients underwent [18F]PSMA-1007 PET/CT, and 8 patients underwent [68Ga]Ga-DOTA-TOC PET/CT. Signal-to-noise ratio (SNR) and standardised uptake values (SUVmean/max/peak) were used to compare UHS and HS with different acquisition times. RESULTS The SNR was significantly higher for UHS compared to HS over all acquisition times (SNR UHS/HS [18F]FDG: 1.35 ± 0.02, p < 0.001; [18F]PSMA-1007: 1.25 ± 0.02, p < 0.001; [68Ga]Ga-DOTA-TOC: 1.29 ± 0.02, p < 0.001). CONCLUSION UHS showed significantly higher SNR opening the possibility of halving short acquisition times. This is of advantage in further reduction of whole-body PET/CT acquisition.
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Affiliation(s)
- Clemens Mingels
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, 3010, Bern, Switzerland.
| | - Sabine Weidner
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, 3010, Bern, Switzerland
| | - Hasan Sari
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, 3010, Bern, Switzerland.,Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland
| | - Dorothee Buesser
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, 3010, Bern, Switzerland
| | - Konstantinos Zeimpekis
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, 3010, Bern, Switzerland
| | - Kuangyu Shi
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, 3010, Bern, Switzerland
| | - Ian Alberts
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, 3010, Bern, Switzerland
| | - Axel Rominger
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, 3010, Bern, Switzerland
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15
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Huang Y, Wang M, Jiang L, Wang L, Chen L, Wang Q, Feng J, Wang J, Xu W, Wu H, Han Y. Optimal clinical protocols for total-body 18F-FDG PET/CT examination under different activity administration plans. EJNMMI Phys 2023; 10:14. [PMID: 36808378 PMCID: PMC9938848 DOI: 10.1186/s40658-023-00533-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 02/10/2023] [Indexed: 02/20/2023] Open
Abstract
BACKGROUND Highly sensitive digital total-body PET/CT scanners (uEXPLORER) have great potential for clinical applications and fundamental research. Given their increasing sensitivity, low-dose scanning or snapshot imaging is now possible in clinics. However, a standardized total-body 18F-FDG PET/CT protocol is still lacking. Establishing a standard clinical protocol for total-body 18F-FDG PET/CT examination under different activity administration plans can help provide a theoretical reference for nuclear radiologists. METHODS The NEMA image quality (IQ) phantom was used to evaluate the biases of various total-body 18F-FDG PET/CT protocols related to the administered activity, scan duration, and iterations. Several objective metrics, including contrast recovery (CR), background variability (BV), and contrast-to-noise ratio (CNR), were measured from different protocols. In line with the European Association of Nuclear Medicine Research Ltd. (EARL) guidelines, optimized protocols were suggested and evaluated for total-body 18F-FDG PET/CT imaging for three different injected activities. RESULTS Our NEMA IQ phantom evaluation resulted in total-body PET/CT images with excellent contrast and low noise, suggesting great potential for reducing administered activity or shortening the scan duration. Different to the iteration number, prolonging the scan duration was the first choice for achieving higher image quality regardless of the activity administered. In light of image quality, tolerance of oncological patients, and the risk of ionizing radiation damage, the 3-min acquisition and 2-iteration (CNR = 7.54), 10-min acquisition and 3-iteration (CNR = 7.01), and 10-min acquisition and 2-iteration (CNR = 5.49) protocols were recommended for full-dose (3.70 MBq/kg), half-dose (1.95 MBq/kg), and quarter-dose (0.98 MBq/kg) activity injection schemes, respectively. Those protocols were applied in clinical practices, and no significant differences were observed for the SUVmax of large/small lesions or the SUVmean of different healthy organs/tissues. CONCLUSION These findings support that digital total-body PET/CT scanners can generate PET images with a high CNR and low-noise background, even with a short acquisition time and low administered activity. The proposed protocols for different administered activities were determined to be valid for clinical examination and can maximize the value of this imaging type.
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Affiliation(s)
- Yanchao Huang
- grid.284723.80000 0000 8877 7471Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Meng Wang
- grid.284723.80000 0000 8877 7471Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Li Jiang
- grid.284723.80000 0000 8877 7471Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Lijuan Wang
- grid.284723.80000 0000 8877 7471Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Li Chen
- grid.284723.80000 0000 8877 7471Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Qiaoyu Wang
- grid.284723.80000 0000 8877 7471Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jiatai Feng
- grid.497849.fCentral Research Institute, United Imaging Healthcare, Shanghai, China
| | - Jingyi Wang
- grid.497849.fCentral Research Institute, United Imaging Healthcare, Shanghai, China
| | - Wanbang Xu
- grid.506955.aDepartment of Traditional Chinese Medicine, Guangdong Institute for Drug Control, Guangzhou, China
| | - Hubing Wu
- grid.284723.80000 0000 8877 7471Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yanjiang Han
- Laboratory for Quality Control and Evaluation of Radiopharmaceuticals, Department of Nuclear Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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Li Y, Hu J, Sari H, Xue S, Ma R, Kandarpa S, Visvikis D, Rominger A, Liu H, Shi K. A deep neural network for parametric image reconstruction on a large axial field-of-view PET. Eur J Nucl Med Mol Imaging 2023; 50:701-714. [PMID: 36326869 DOI: 10.1007/s00259-022-06003-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 10/09/2022] [Indexed: 11/06/2022]
Abstract
PURPOSE The PET scanners with long axial field of view (AFOV) having ~ 20 times higher sensitivity than conventional scanners provide new opportunities for enhanced parametric imaging but suffer from the dramatically increased volume and complexity of dynamic data. This study reconstructed a high-quality direct Patlak Ki image from five-frame sinograms without input function by a deep learning framework based on DeepPET to explore the potential of artificial intelligence reducing the acquisition time and the dependence of input function in parametric imaging. METHODS This study was implemented on a large AFOV PET/CT scanner (Biograph Vision Quadra) and twenty patients were recruited with 18F-fluorodeoxyglucose (18F-FDG) dynamic scans. During training and testing of the proposed deep learning framework, the last five-frame (25 min, 40-65 min post-injection) sinograms were set as input and the reconstructed Patlak Ki images by a nested EM algorithm on the vendor were set as ground truth. To evaluate the image quality of predicted Ki images, mean square error (MSE), peak signal-to-noise ratio (PSNR), and structural similarity index measure (SSIM) were calculated. Meanwhile, a linear regression process was applied between predicted and true Ki means on avid malignant lesions and tumor volume of interests (VOIs). RESULTS In the testing phase, the proposed method achieved excellent MSE of less than 0.03%, high SSIM, and PSNR of ~ 0.98 and ~ 38 dB, respectively. Moreover, there was a high correlation (DeepPET: [Formula: see text]= 0.73, self-attention DeepPET: [Formula: see text]=0.82) between predicted Ki and traditionally reconstructed Patlak Ki means over eleven lesions. CONCLUSIONS The results show that the deep learning-based method produced high-quality parametric images from small frames of projection data without input function. It has much potential to address the dilemma of the long scan time and dependency on input function that still hamper the clinical translation of dynamic PET.
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Affiliation(s)
- Y Li
- College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, People's Republic of China.,College of Optical Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China
| | - J Hu
- Department of Nuclear Medicine, Inselpital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - H Sari
- Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland
| | - S Xue
- Department of Nuclear Medicine, Inselpital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - R Ma
- Department of Nuclear Medicine, Inselpital, Bern University Hospital, University of Bern, Bern, Switzerland.,Department of Engineering Physics, Tsinghua University, Beijing, China
| | - S Kandarpa
- LaTIM, INSERM, UMR 1101, University of Brest, Brest, France
| | - D Visvikis
- LaTIM, INSERM, UMR 1101, University of Brest, Brest, France
| | - A Rominger
- Department of Nuclear Medicine, Inselpital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - H Liu
- College of Optical Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China.
| | - K Shi
- Department of Nuclear Medicine, Inselpital, Bern University Hospital, University of Bern, Bern, Switzerland.,Computer Aided Medical Procedures and Augmented Reality, Institute of Informatics I16, Technical University of Munich, Munich, Germany
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Chen R, Yang X, Yu X, Zhou X, Ng YL, Chen Y, Li L, Zhou Y, Huang G, Liu J. The feasibility of ultra-early and fast total‑body [ 68 Ga]Ga-FAPI-04 PET/CT scan. Eur J Nucl Med Mol Imaging 2023; 50:661-666. [PMID: 36308535 DOI: 10.1007/s00259-022-06004-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 10/10/2022] [Indexed: 01/24/2023]
Abstract
PURPOSE [68 Ga]Ga-FAPI-04 PET/CT has been widely used in oncology patients. The patients need to lie still for 20-30 min during scan after waiting for 60 min post-tracer injection in traditional [68 Ga]Ga-FAPI-04 PET/CT scan. This is difficult for some patients who are intolerant to prolonged horizontal positioning and waiting time. Therefore, we evaluated the diagnostic value of the images obtained in ultra-early and fast scan (5-min p.i., 30-s acquisition time) by the total-body [68 Ga]Ga-FAPI-04 PET/CT and to investigate whether they could meet the requirements of clinical diagnosis. METHODS Total-body [68 Ga]Ga-FAPI-04 PET/CT was conducted in 12 patients at the Renji Hospital. Patients underwent PET with two acquisitions: 5-min p.i. and 30-s acquisition time (ultra-early and fast imaging) and 60-min p.i. and 300-s acquisition time (traditional imaging). Mean [68 Ga]Ga-FAPI-04 injection dose was 1.85 MBq/kg. RESULTS Forty-four lesions were detected in 12 patients on traditional imaging. All the 44 lesions on conventional imaging could also detected by ultra-early and fast imaging. For all the 12 patients, the tumor stage did not change, as same lesions were visible for every case in both images. There was no statistically significant difference in SUVmax of lesions between ultra-early and fast imaging and traditional imaging (12.5 ± 8.7 vs 13.7 ± 8.5, P = 0.528). Background bloodpool (4.0 ± 0.6 vs 0.9 ± 0.2, P < 0.001)and liver (2.5 ± 0.7 vs 1.0 ± 0.5, P < 0.001)at traditional imaging showed a significant decrease in SUVmean compared to ultra-early and fast imaging. CONCLUSIONS Ultra-early and fast imaging versus traditional [68 Ga]Ga-FAPI-04 imaging resulted in equivalent tumor detection and lesion uptake. Ultra-early and fast total-body [68 Ga]Ga-FAPI-04 PET/CT scan could meet clinical diagnostic requirements for patients with poor tolerant to prolonged horizontal positioning and waiting time.
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Affiliation(s)
- Ruohua Chen
- Department of Nuclear Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Xinlan Yang
- Central Research Institute, United Imaging Healthcare Group Co, Ltd, Shanghai, China
| | - Xiaofeng Yu
- Department of Nuclear Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Xiang Zhou
- Department of Nuclear Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yee Ling Ng
- Central Research Institute, United Imaging Healthcare Group Co, Ltd, Shanghai, China
| | - Yumei Chen
- Department of Nuclear Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Lianghua Li
- Department of Nuclear Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yun Zhou
- Central Research Institute, United Imaging Healthcare Group Co, Ltd, Shanghai, China
| | - Gang Huang
- Department of Nuclear Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, Shanghai, China.
| | - Jianjun Liu
- Department of Nuclear Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, Shanghai, China.
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18
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Daube-Witherspoon ME, Pantel AR, Pryma DA, Karp JS. Total-body PET: a new paradigm for molecular imaging. Br J Radiol 2022; 95:20220357. [PMID: 35993615 PMCID: PMC9733603 DOI: 10.1259/bjr.20220357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/25/2022] [Accepted: 08/12/2022] [Indexed: 11/05/2022] Open
Abstract
Total body (TB) positron emission tomography (PET) instruments have dramatically changed the paradigm of PET clinical and research studies due to their very high sensitivity and capability to image dynamic radiopharmaceutical distributions in the major organs of the body simultaneously. In this manuscript, we review the design of these systems and discuss general challenges and trade-offs to maximize the performance gains of current TB-PET systems. We then describe new concepts and technology that may impact future TB-PET systems. The manuscript summarizes what has been learned from the initial sites with TB-PET and explores potential research and clinical applications of TB-PET. The current generation of TB-PET systems range in axial field-of-view (AFOV) from 1 to 2 m and serve to illustrate the benefits and opportunities of a longer AFOV for various applications in PET. In only a few years of use these new TB-PET systems have shown that they will play an important role in expanding the field of molecular imaging and benefiting clinical practice.
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Affiliation(s)
| | - Austin R Pantel
- Department of Radiology, University of Pennsylvania, Philadelphia, United States
| | - Daniel A Pryma
- Department of Radiology, University of Pennsylvania, Philadelphia, United States
| | - Joel S Karp
- Department of Radiology, University of Pennsylvania, Philadelphia, United States
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19
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The feasibility of ultralow-activity 18F-FDG dynamic PET imaging in lung adenocarcinoma patients through total-body PET/CT scanner. Ann Nucl Med 2022; 36:887-896. [PMID: 35857172 DOI: 10.1007/s12149-022-01772-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 07/03/2022] [Indexed: 11/01/2022]
Abstract
OBJECTIVE To explore the feasibility of ultralow-activity 18F-FDG total-body dynamic PET imaging for clinical practice in patients with lung adenocarcinoma. METHODS Eight of 18 patients were randomly injected with 18F-FDG with full activity (3.7 MBq/kg) for total-body dynamic PET imaging, while 10 received one-tenth activity (0.37 MBq/kg). The generated time-to-activity curves (TACs) according to the regions of interest (ROIs) were processed by PMOD through standard FDG two-tissue compartment model fitting. The kinetic constant rates (K1, K2, K3, and Ki), radiation dose, prompt counts, and data storage size were analysed between the full- and ultralow-activity groups. The SUVmax-Tumour/SUVmax-Liver and SUVmax-Tumour/SUVmax-Muscle on static PET images were also assessed. RESULTS Each of the fitted models has a satisfactory goodness-of-fit with R2 greater than 0.9 except 3 (3/234) in ultralow-activity group, where one in pancreas (R2 = 0.851), another one in muscle (R2 = 0.868), and the third one in bone marrow (R2 = 0.895). All the fitted models in the full-activity group had a better goodness-of-fit than those in the ultralow-activity group. However, no significant differences were found in any of the kinetic metrics or image quality between the two groups except in the reduction of radiation dose and data storage size. CONCLUSIONS The 10 × reduction of injected 18F-FDG could achieve comparable kinetic metrics and T/N ratios by total-body dynamic PET imaging in lung adenocarcinoma patients. Ultralow-activity total-body PET imaging is feasible for clinical practice in oncological patients without obesity, especially in dynamic PET scanning.
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20
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Ma R, Hu J, Sari H, Xue S, Mingels C, Viscione M, Kandarpa VSS, Li WB, Visvikis D, Qiu R, Rominger A, Li J, Shi K. An encoder-decoder network for direct image reconstruction on sinograms of a long axial field of view PET. Eur J Nucl Med Mol Imaging 2022; 49:4464-4477. [PMID: 35819497 DOI: 10.1007/s00259-022-05861-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 06/02/2022] [Indexed: 11/04/2022]
Abstract
PURPOSE Deep learning is an emerging reconstruction method for positron emission tomography (PET), which can tackle complex PET corrections in an integrated procedure. This paper optimizes the direct PET reconstruction from sinogram on a long axial field of view (LAFOV) PET. METHODS This paper proposes a novel deep learning architecture to reduce the biases during direct reconstruction from sinograms to images. This architecture is based on an encoder-decoder network, where the perceptual loss is used with pre-trained convolutional layers. It is trained and tested on data of 80 patients acquired from recent Siemens Biograph Vision Quadra long axial FOV (LAFOV) PET/CT. The patients are randomly split into a training dataset of 60 patients, a validation dataset of 10 patients, and a test dataset of 10 patients. The 3D sinograms are converted into 2D sinogram slices and used as input to the network. In addition, the vendor reconstructed images are considered as ground truths. Finally, the proposed method is compared with DeepPET, a benchmark deep learning method for PET reconstruction. RESULTS Compared with DeepPET, the proposed network significantly reduces the root-mean-squared error (NRMSE) from 0.63 to 0.6 (p < 0.01) and increases the structural similarity index (SSIM) and peak signal-to-noise ratio (PSNR) from 0.93 to 0.95 (p < 0.01) and from 82.02 to 82.36 (p < 0.01), respectively. The reconstruction time is approximately 10 s per patient, which is shortened by 23 times compared with the conventional method. The errors of mean standardized uptake values (SUVmean) for lesions between ground truth and the predicted result are reduced from 33.5 to 18.7% (p = 0.03). In addition, the error of max SUV is reduced from 32.7 to 21.8% (p = 0.02). CONCLUSION The results demonstrate the feasibility of using deep learning to reconstruct images with acceptable image quality and short reconstruction time. It is shown that the proposed method can improve the quality of deep learning-based reconstructed images without additional CT images for attenuation and scattering corrections. This study demonstrated the feasibility of deep learning to rapidly reconstruct images without additional CT images for complex corrections from actual clinical measurements on LAFOV PET. Despite improving the current development, AI-based reconstruction does not work appropriately for untrained scenarios due to limited extrapolation capability and cannot completely replace conventional reconstruction currently.
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Affiliation(s)
- Ruiyao Ma
- Department of Engineering Physics, Tsinghua University, and Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, 100084, China.,Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Institute of Radiation Medicine, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Bavaria, Neuherberg, Germany
| | - Jiaxi Hu
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Hasan Sari
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland
| | - Song Xue
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Clemens Mingels
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Marco Viscione
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | | | - Wei Bo Li
- Institute of Radiation Medicine, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Bavaria, Neuherberg, Germany
| | | | - Rui Qiu
- Department of Engineering Physics, Tsinghua University, and Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, 100084, China.
| | - Axel Rominger
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Junli Li
- Department of Engineering Physics, Tsinghua University, and Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing, 100084, China.
| | - Kuangyu Shi
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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21
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Wang Z, Cao X, LaBella A, Zeng X, Biegon A, Franceschi D, Petersen E, Clayton N, Ulaner GA, Zhao W, Goldan AH. High-resolution and high-sensitivity PET for quantitative molecular imaging of the monoaminergic nuclei: A GATE simulation study. Med Phys 2022; 49:4430-4444. [PMID: 35390182 PMCID: PMC11025683 DOI: 10.1002/mp.15653] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 02/03/2022] [Accepted: 03/07/2022] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Quantitative in vivo molecular imaging of fine brain structures requires high-spatial resolution and high-sensitivity. Positron emission tomography (PET) is an attractive candidate to introduce molecular imaging into standard clinical care due to its highly targeted and versatile imaging capabilities based on the radiotracer being used. However, PET suffers from relatively poor spatial resolution compared to other clinical imaging modalities, which limits its ability to accurately quantify radiotracer uptake in brain regions and nuclei smaller than 3 mm in diameter. Here we introduce a new practical and cost-effective high-resolution and high-sensitivity brain-dedicated PET scanner, using our depth-encoding Prism-PET detector modules arranged in a conformal decagon geometry, to substantially reduce the partial volume effect and enable accurate radiotracer uptake quantification in small subcortical nuclei. METHODS Two Prism-PET brain scanner setups were proposed based on our 4-to-1 and 9-to-1 coupling of scintillators to readout pixels using1.5 × 1.5 × 20 $1.5 \times 1.5 \times 20$ mm3 and0.987 × 0.987 × 20 $0.987 \times 0.987 \times 20$ mm3 crystal columns, respectively. Monte Carlo simulations of our Prism-PET scanners, Siemens Biograph Vision, and United Imaging EXPLORER were performed using Geant4 application for tomographic emission (GATE). National Electrical Manufacturers Association (NEMA) standard was followed for the evaluation of spatial resolution, sensitivity, and count-rate performance. An ultra-micro hot spot phantom was simulated for assessing image quality. A modified Zubal brain phantom was utilized for radiotracer imaging simulations of 5-HT1A receptors, which are abundant in the raphe nuclei (RN), and norepinephrine transporters, which are highly concentrated in the bilateral locus coeruleus (LC). RESULTS The Prism-PET brain scanner with 1.5 mm crystals is superior to that with 1 mm crystals as the former offers better depth-of-interaction (DOI) resolution, which is key to realizing compact and conformal PET scanner geometries. We achieved uniform 1.3 mm full-width-at-half-maximum (FWHM) spatial resolutions across the entire transaxial field-of-view (FOV), a NEMA sensitivity of 52.1 kcps/MBq, and a peak noise equivalent count rate (NECR) of 957.8 kcps at 25.2 kBq/mL using 450-650 keV energy window. Hot spot phantom results demonstrate that our scanner can resolve regions as small as 1.35 mm in diameter at both center and 10 cm away from the center of the transaixal FOV. Both 5-HT1A receptor and norepinephrine transporter brain simulations prove that our Prism-PET scanner enables accurate quantification of radiotracer uptake in small brain regions, with a 1.8-fold and 2.6-fold improvement in the dorsal RN as well as a 3.2-fold and 4.4-fold improvement in the bilateral LC compared to the Biograph Vision and EXPLORER, respectively. CONCLUSIONS Based on our simulation results, the proposed high-resolution and high-sensitivity Prism-PET brain scanner is a promising cost-effective candidate to achieve quantitative molecular neuroimaging of small but important brain regions with PET clinically viable.
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Affiliation(s)
- Zipai Wang
- Department of Biomedical Engineering, College of Engineering and Applied Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Xinjie Cao
- Department of Electrical and Computer Engineering, College of Engineering and Applied Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Andy LaBella
- Department of Radiology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Xinjie Zeng
- Department of Electrical and Computer Engineering, College of Engineering and Applied Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Anat Biegon
- Department of Radiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Dinko Franceschi
- Department of Radiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Eric Petersen
- Department of Biomedical Engineering, College of Engineering and Applied Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Nicholas Clayton
- Department of Radiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Gary A. Ulaner
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Molecular Imaging and Therapy, Hoag Family Cancer Institute, Newport Beach, California, USA
| | - Wei Zhao
- Department of Radiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Amir H. Goldan
- Department of Radiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, USA
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22
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Liu G, Yu H, Shi D, Hu P, Hu Y, Tan H, Zhang Y, Yin H, Shi H. Short-time total-body dynamic PET imaging performance in quantifying the kinetic metrics of 18F-FDG in healthy volunteers. Eur J Nucl Med Mol Imaging 2022; 49:2493-2503. [PMID: 34417855 DOI: 10.1007/s00259-021-05500-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 07/18/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE To investigate the performance of short-time dynamic imaging in quantifying kinetic metrics of 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG). METHODS Dynamic total-body positron emission tomography (PET) imaging was performed in 11 healthy volunteers for 75 min. The data were divided into 30-, 45- and 75-min groups. Nonlinear regression (NLR) generated constant rates (k1 to k3) and NLR-based Ki in various organs. The Patlak method calculated parametric Ki images to generate Patlak-based Ki values. Paired samples t-test or the Wilcoxon signed-rank test compared the kinetic metrics between the groups, depending on data normality. Deming regression and Bland-Altman analysis assessed the correlation and agreement between NLR- and Patlak-based Ki. A two-sided P < 0.05 was considered statistically significant. RESULTS The 45- and 75-min groups were similar in NLR-based kinetic metrics. The relative difference ranges were as follows: k1, from 3.4% (P = 0.627) in the spleen to 57.9% (P = 0.130) in the white matter; k2, from 6.0% (P = 0.904) in the spleen to 60.7% (P = 0.235) in the left ventricle (LV) myocardium; k3, from 45.6% (P = 0.302) in the LV myocardium to 96.3% (P = 0.478) in the liver; Ki, from 14.0% (P = 0.488) in the liver to 77.8% (P = 0.067) in the kidney. Patlak-based Ki values were also similar between these groups in all organs, except the grey matter (9.6%, P = 0.029) and cerebellum (14.4%, P = 0.002). However, significant differences in kinetic metrics were found between the 30-min and 75-min groups in most organs both in NLR- and Patlak-based analyses. The NLR- and Patlak-based Ki values significantly correlated, with no bias in any of the organs. CONCLUSION Dynamic imaging using a high-sensitivity total-body PET scanner for a shorter time of 45 min could achieve relevant kinetic metrics of 18F-FDG as done by long-time imaging.
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Affiliation(s)
- Guobing Liu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Haojun Yu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Dai Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Pengcheng Hu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Yan Hu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Hui Tan
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Yiqiu Zhang
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Hongyan Yin
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China
- Shanghai Institute of Medical Imaging, Shanghai, 200032, China
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Hongcheng Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, People's Republic of China.
- Institute of Nuclear Medicine, Fudan University, Shanghai, 200032, China.
- Shanghai Institute of Medical Imaging, Shanghai, 200032, China.
- Cancer Prevention and Treatment Center, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
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Ito T, Maeno T, Tsuchikame H, Shishido M, Nishi K, Kojima S, Hayashi T, Suzuki K. Adapting a low-count acquisition of the bone scintigraphy using deep denoising super-resolution convolutional neural network. Phys Med 2022; 100:18-25. [PMID: 35716484 DOI: 10.1016/j.ejmp.2022.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/21/2022] [Accepted: 06/11/2022] [Indexed: 10/18/2022] Open
Abstract
PURPOSE Deep-layer learning processing may improve contrast imaging with greater precision in low-count acquisition. However, no data on noise reduction using super-resolution processing for deep-layer learning have been reported in nuclear medicine imaging. OBJECTIVES This study was designed to evaluate the adaptability of deep denoising super-resolution convolutional neural networks (DDSRCNN) in nuclear medicine by comparing them with denoising convolutional natural networks (DnCNN), Gaussian processing, and nonlinear diffusion (NLD) processing. METHODS In this study, 156 patients were included. Data were collected using a matrix size of 256 × 256 with a pixel size of 2.46 mm at 0.898 folds, 15% energy window at the center of the photopeak energy (140 keV), and total count of 1000 kilocounts (kct). Following the training and validation of two learning models, we created 100 images for each 20-test datum. The peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) between each image and the reference image were calculated. RESULTS DDSRCNN showed the highest PSNR values for all total counts. Regarding SSIM, DDSRCNN had significantly higher values than the original and Gaussian. In DnCNN, false accumulation was observed as the total counts increased. Regarding PSNR and SSIM transition, the model using 100-500-kct training data was significantly higher than that using 100-kct training data. CONCLUSIONS Edge-preserving noise reduction processing was possible, and adaptability to low-count acquisition was demonstrated using DDSRCNN. Using training data with different noise levels, DDSRCNN could learn the noise components with high accuracy and contrast improvement.
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Affiliation(s)
- Toshimune Ito
- Department of Radiological, Technology, Faculty of Medical Technology, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan.
| | - Takafumi Maeno
- Department of Radiology, Saiseikai Yokohamashi Tobu Hospital, 3-6-1 Shimosueyoshi, Tsurumi-ku, Yokohama, Kanagawa 230-0012, Japan.
| | - Hirotatsu Tsuchikame
- Department of Radiology, Saiseikai Yokohamashi Tobu Hospital, 3-6-1 Shimosueyoshi, Tsurumi-ku, Yokohama, Kanagawa 230-0012, Japan.
| | - Masaaki Shishido
- Department of Radiology, Saiseikai Yokohamashi Tobu Hospital, 3-6-1 Shimosueyoshi, Tsurumi-ku, Yokohama, Kanagawa 230-0012, Japan.
| | - Kana Nishi
- Department of Radiology, Saiseikai Yokohamashi Tobu Hospital, 3-6-1 Shimosueyoshi, Tsurumi-ku, Yokohama, Kanagawa 230-0012, Japan
| | - Shinya Kojima
- Department of Radiological, Technology, Faculty of Medical Technology, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan.
| | - Tatsuya Hayashi
- Department of Radiological, Technology, Faculty of Medical Technology, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan.
| | - Kentaro Suzuki
- Department of Radiological Technology, Toranomon Hospital, 2-2-2 Tranomon, Minato-ku, Tokyo 105-8470, Japan; Department of Radiation Oncology, Graduated School of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, Japan.
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Li A, Xie Q, Huang J, Xiao P. Evaluation of applying space-variant resolution modeling to attenuation correction in PET. Biomed Phys Eng Express 2022; 8:045009. [PMID: 35623332 DOI: 10.1088/2057-1976/ac741c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Attenuation correction aims to recover the underestimated tracer uptake and improve the image contrast recovery in positron emission tomography (PET). However, traditional ray-tracing-based projection of attenuation maps is inaccurate as some physical effects are not considered, such as finite crystal size, inter-crystal penetration and inter-crystal scatter. In this study, we evaluated the effects of applying resolution modeling (RM) to attenuation correction by implementing space-variant RM to complement physical effects which are usually omitted in the traditional projection model. We verified this method on a brain PET scanner developed by our group, in both Monte Carlo simulation and real-world data, in comparison with space-invariant Gaussian RM, average-depth-of-interaction, and multi-ray tracing methods. The results indicate that the space-variant RM is superior in terms of artifacts reduction and contrast recovery.
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Affiliation(s)
- Ang Li
- College of life science and technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province, China, Wuhan, 430074, CHINA
| | - Qingguo Xie
- Biomedical Engineering Department, Huazhong University of Science and Technology, Wuhan, Hubei 430074, Wuhan, Hubei, 430074, CHINA
| | - Jing Huang
- Huazhong University of Science and Technology, 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province, China, Wuhan, 430074, CHINA
| | - Peng Xiao
- Biomedical Engineering Department, Huazhong University of Science and Technology, Wuhan, Hubei 430074, Wuhan, Hubei, 430074, CHINA
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Karakatsanis NA, Nehmeh MH, Conti M, Bal G, González AJ, Nehmeh SA. Physical performance of adaptive axial FOV PET scanners with a sparse detector block rings or a checkerboard configuration. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac6aa1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 04/26/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. Using Monte-Carlo simulations, we evaluated the physical performance of a hypothetical state-of-the-art clinical PET scanner with adaptive axial field-of-view (AFOV) based on the validated GATE model of the Siemens Biograph VisionTM PET/CT scanner. Approach. Vision consists of 16 compact PET rings, each consisting of 152 mini-blocks of 5 × 5 Lutetium Oxyorthosilicate crystals (3.2 × 3.2 × 20 mm3). The Vision 25.6 cm AFOV was extended by adopting (i) a sparse mini-block ring (SBR) configuration of 49.6 cm AFOV, with all mini-block rings interleaved with 16 mm axial gaps, or (ii) a sparse mini-block checkerboard (SCB) configuration of 51.2 cm AFOV, with all mini-blocks interleaved with gaps of 16 mm (transaxial) × 16 mm (axial) width in checkerboard pattern. For sparse configurations, a ‘limited’ continuous bed motion (limited-CBM) acquisition was employed to extend AFOVs by 2.9 cm. Spatial resolution, sensitivity, image quality (IQ), NECR and scatter fraction were assessed per NEMA NU2-2012. Main Results. All IQ phantom spheres were distinguishable with all configurations. SBR and SCB percent contrast recovery (% CR) and background variability (% BV) were similar (p-value > 0.05). Compared to Vision, SBR and SCB %CRs were similar (p-values > 0.05). However, SBR and SCB %BVs were deteriorated by 30% and 26% respectively (p-values < 0.05). SBR, SCB and Vision exhibited system sensitivities of 16.6, 16.8, and 15.8 kcps MBq−1, NECRs of 311 kcps @35 kBq cc−1, 266 kcps @25.8 kBq cc−1, and 260 kcps @27.8 kBq cc−1, and scatter fractions of 31.2%, 32.4%, and 32.6%, respectively. SBR and SCB exhibited a smoother sensitivity reduction and noise enhancement rate from AFOV center to its edges. SBR and SCB attained comparable spatial resolution in all directions (p-value > 0.05), yet, up to 1.5 mm worse than Vision (p-values < 0.05). Significance. The proposed sparse configurations may offer a clinically adoptable solution for cost-effective adaptive AFOV PET with either highly-sensitive or long-AFOV acquisitions.
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Zhang Y, Hu P, He Y, Yu H, Tan H, Liu G, Gu J, Shi H. Ultrafast 30-s total-body PET/CT scan: a preliminary study. Eur J Nucl Med Mol Imaging 2022; 49:2504-2513. [PMID: 35578037 DOI: 10.1007/s00259-022-05838-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 05/07/2022] [Indexed: 02/01/2023]
Abstract
PURPOSE The aim of this study is to explore the diagnostic value of the images obtained in ultrafast 30-s acquisition time by the total-body PET/CT (18F-FDG injection dose of about 3.7 MBq/kg), and to evaluate whether they can meet the requirements of clinical diagnosis or not. METHODS This retrospective study explored the clinical value of ultrafast 30-s 18F-FDG total-body PET/CT in 88 oncology patients, using the post-surgical pathological diagnosis as the reference standard. The data were acquired over 300 s and reconstructed using all 300-s data (G300) and only the initial 30 s (G30). Two readers independently assessed all images qualitatively and quantitatively. The diagnostic performance was compared between G300 and G30. RESULTS The G300 average qualitative score was higher than G30 (P < 0.001). G300 and G30 also differed quantitatively in the liver and mediastinum SUVmax, SD, and SNR (all P < 0.001), but had similar sensitivities (89.09% vs. 86.36%, P = 0.250). The G300 group had higher accuracy (79.73%) and a larger area under the curve (0.709) than G30 (77.70% and 0.695, respectively; all P > 0.05). CONCLUSION The 30-s total-body PET/CT could meet clinical diagnostic requirements for malignant tumors in patients intolerant to prolonged horizontal positioning.
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Affiliation(s)
- Yiqiu Zhang
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd., Shanghai, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, China.,Shanghai Institute of Medical Imaging, Shanghai, China
| | - Pengcheng Hu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd., Shanghai, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, China.,Shanghai Institute of Medical Imaging, Shanghai, China
| | - Yibo He
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd., Shanghai, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, China.,Shanghai Institute of Medical Imaging, Shanghai, China
| | - Haojun Yu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd., Shanghai, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, China.,Shanghai Institute of Medical Imaging, Shanghai, China
| | - Hui Tan
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd., Shanghai, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, China.,Shanghai Institute of Medical Imaging, Shanghai, China
| | - Guobing Liu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd., Shanghai, China.,Institute of Nuclear Medicine, Fudan University, Shanghai, China.,Shanghai Institute of Medical Imaging, Shanghai, China
| | - Jianying Gu
- Department of Plastic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
| | - Hongcheng Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd., Shanghai, China. .,Institute of Nuclear Medicine, Fudan University, Shanghai, China. .,Shanghai Institute of Medical Imaging, Shanghai, China.
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Andreou C, Weissleder R, Kircher MF. Multiplexed imaging in oncology. Nat Biomed Eng 2022; 6:527-540. [PMID: 35624151 DOI: 10.1038/s41551-022-00891-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 09/06/2021] [Indexed: 01/24/2023]
Abstract
In oncology, technologies for clinical molecular imaging are used to diagnose patients, establish the efficacy of treatments and monitor the recurrence of disease. Multiplexed methods increase the number of disease-specific biomarkers that can be detected simultaneously, such as the overexpression of oncogenic proteins, aberrant metabolite uptake and anomalous blood perfusion. The quantitative localization of each biomarker could considerably increase the specificity and the accuracy of technologies for clinical molecular imaging to facilitate granular diagnoses, patient stratification and earlier assessments of the responses to administered therapeutics. In this Review, we discuss established techniques for multiplexed imaging and the most promising emerging multiplexing technologies applied to the imaging of isolated tissues and cells and to non-invasive whole-body imaging. We also highlight advances in radiology that have been made possible by multiplexed imaging.
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Affiliation(s)
- Chrysafis Andreou
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.,Center for Molecular Imaging and Nanotechnology (CMINT), Memorial Sloan Kettering Cancer Center, New York, NY, USA.,Department of Electrical and Computer Engineering, University of Cyprus, Nicosia, Cyprus
| | - Ralph Weissleder
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. .,Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. .,Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
| | - Moritz F Kircher
- Molecular Pharmacology Program, Sloan Kettering Institute, New York, NY, USA.,Department of Imaging, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA.,Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Hu Y, Liu G, Yu H, Gu J, Shi H. Diagnostic performance of total-body 18F-FDG PET/CT with fast 2-min acquisition for liver tumours: comparison with conventional PET/CT. Eur J Nucl Med Mol Imaging 2022; 49:3538-3546. [PMID: 35344063 DOI: 10.1007/s00259-022-05772-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 03/19/2022] [Indexed: 12/29/2022]
Abstract
PURPOSE To comparatively evaluate the diagnostic performances of total-body 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG PET/CT) with fast 2-min acquisition and conventional PET/CT in liver cancer patients. METHODS This study included 156 patients with liver tumours. Seventy-eight patients underwent total-body PET/CT. PET raw data were reconstructed using acquisition durations of 2 min (G2) and 15 min (G15). Another 78 patients with liver lesions (control patients) underwent conventional uMI780 PET/CT (G780). All patients were evaluated based on TNM staging. The maximum tumour standardized uptake value (tumour SUVmax), mean normal liver SUV (SUVmean), and tumour SUVmax-to-liver SUVmean ratio (TLR) were determined for all patients. G15 data were used as the reference in the lesion detectability analysis. The diagnostic performances of PET/CT in terms of visual parameters and of PET in terms of semi-quantitative parameters such as SUVmax and TLR were evaluated. Receiver operating characteristics (ROC) curve analysis of SUVmax and TLR at G2 was performed. Pathologic findings of surgical specimens served as the gold standard for all patients. RESULTS The lesions found in G15 were also noted in G2; three lymph nodes were missed in G2. However, no significant difference was found in the TNM stage among G2, G15, and G780. For benign and malignant lesions, the liver SUVmean in G2 and G15 was higher than that in G780 (all P < 0.05). The tumour SUVmax and TLR in G2 were equivalent to those in G15 and G780 regardless of whether the lesions were benign or malignant. ROC curve analysis (SUVmax cutoff: 4.34, TLR cutoff: 1.34) demonstrated that G2 also had good sensitivity in detecting liver cancer. CONCLUSION The diagnostic performance of total-body PET/CT in G2 was comparable to that in G15 among liver cancer patients. Further, the diagnostic efficiency of total-body PET/CT imaging with fast 2-min acquisition and conventional PET/CT was similar.
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Affiliation(s)
- Yan Hu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Nuclear Medicine Institute of Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Guobing Liu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Nuclear Medicine Institute of Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Haojun Yu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.,Nuclear Medicine Institute of Fudan University, Shanghai, 200032, China.,Shanghai Institute of Medical Imaging, Shanghai, 200032, China
| | - Jianying Gu
- Department of Plastic Surgery, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.
| | - Hongcheng Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China. .,Nuclear Medicine Institute of Fudan University, Shanghai, 200032, China. .,Shanghai Institute of Medical Imaging, Shanghai, 200032, China.
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Ouyang Z, Zhao S, Cheng Z, Duan Y, Chen Z, Zhang N, Liang D, Hu Z. Dynamic PET Imaging Using Dual Texture Features. Front Comput Neurosci 2022; 15:819840. [PMID: 35069162 PMCID: PMC8782430 DOI: 10.3389/fncom.2021.819840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 12/10/2021] [Indexed: 11/16/2022] Open
Abstract
Purpose: This study aims to explore the impact of adding texture features in dynamic positron emission tomography (PET) reconstruction of imaging results. Methods: We have improved a reconstruction method that combines radiological dual texture features. In this method, multiple short time frames are added to obtain composite frames, and the image reconstructed by composite frames is used as the prior image. We extract texture features from prior images by using the gray level-gradient cooccurrence matrix (GGCM) and gray-level run length matrix (GLRLM). The prior information contains the intensity of the prior image, the inverse difference moment of the GGCM and the long-run low gray-level emphasis of the GLRLM. Results: The computer simulation results show that, compared with the traditional maximum likelihood, the proposed method obtains a higher signal-to-noise ratio (SNR) in the image obtained by dynamic PET reconstruction. Compared with similar methods, the proposed algorithm has a better normalized mean squared error (NMSE) and contrast recovery coefficient (CRC) at the tumor in the reconstructed image. Simulation studies on clinical patient images show that this method is also more accurate for reconstructing high-uptake lesions. Conclusion: By adding texture features to dynamic PET reconstruction, the reconstructed images are more accurate at the tumor.
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Affiliation(s)
- Zhanglei Ouyang
- School of Physics, Zhengzhou University, Zhengzhou, China
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Shujun Zhao
- School of Physics, Zhengzhou University, Zhengzhou, China
| | - Zhaoping Cheng
- Department of PET/CT, The First Affiliated Hospital of Shandong First Medical University, Shandong Provincial Qianfoshan Hospital, Jinan, China
| | - Yanhua Duan
- Department of PET/CT, The First Affiliated Hospital of Shandong First Medical University, Shandong Provincial Qianfoshan Hospital, Jinan, China
| | - Zixiang Chen
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Na Zhang
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Dong Liang
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Zhanli Hu
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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Determination of optimal 68 Ga-PSMA PET/CT imaging time in prostate cancers by total-body dynamic PET/CT. Eur J Nucl Med Mol Imaging 2021; 49:2086-2095. [PMID: 34962583 DOI: 10.1007/s00259-021-05659-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 12/12/2021] [Indexed: 01/21/2023]
Abstract
BACKGROUND 68 Ga-PSMA PET/CT has been widely used in patients with prostate cancer. Due to the limited axial field of view of conventional PET scanners, whole-body dynamic 68 Ga-PSMA PET/CT has not been performed. We investigated the time-activity curves (TACs) of prostate cancer pathological lesions and physiologic bladder activity to determine the optimal 68 Ga-PSMA PET/CT imaging time by total-body (TB) PET/CT. METHODS Dynamic TB-PET performed on 11 patients with prostate cancer was analyzed. TACs were obtained by drawing regions of interest in normal organs and pathological lesions (primary prostate lesions and lymph nodes and bone metastases). We evaluated the 68 Ga-PSMA uptake pattern of normal organs, urinary bladder, and pathological lesions. RESULTS The urinary bladder TAC increased slowly between 180 and 330 s post-injection and then rapidly between 5.5 and 60.0 min post-injection. The pathological lesion uptake increased rapidly during the first 5 min post-injection and then slowly through the remaining 55 min. Six minutes post-injection was the optimal time with the highest pathological lesion SUVmean values still higher than the urinary bladder activity value. However, these prostate lesion, lymph node metastasis, and bone metastasis SUVmean values were one-third, one-half, and one-half the corresponding values 60 min post-injection, suggesting that early imaging might miss low PSMA uptake lesions. A minimum of 35 min post-injection was required for the pathological lesions to have SUVmean values similar to the corresponding values at 60 min post-injection (all P > 0.05), even though the pathological lesion SUVmean values showed a continuous upward trend through the 60 min. CONCLUSIONS Combining early dynamic 68 Ga-PSMA PET (75-360 s) and conventional static imaging 60 min post-injection could avoid the urinary bladder activity interference to better detect pathological lesions and lesions with relatively low PSMA uptake. The pathological lesion SUVmean values at 35-59 min and 60 min post-injection were similar, so 68 Ga-PSMA PET imaging could also be made at 35-59 min post-injection.
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Abstract
Abstract
In this partial review and partial attempt at vision of what may be the future of dedicated brain PET scanners, the key implementations of the PET technique, we postulate that we are still on a development path and there is still a lot to be done in order to develop optimal brain imagers. Optimized for particular imaging tasks and protocols, and also mobile, that can be used outside the PET center, in addition to the expected improvements in sensitivity and resolution. For this multi-application concept to be more practical, flexible, adaptable designs are preferred. This task is greatly facilitated by the improved TOF performance that allows for more open, adjustable, limited angular coverage geometries without creating image artifacts. As achieving uniform very high resolution in the whole body is not practical due to technological limits and high costs, hybrid systems using a moderate-resolution total body scanner (such as J-PET) combined with a very high performing brain imager could be a very attractive approach. As well, as using magnification inserts in the total body or long-axial length imagers to visualize selected targets with higher resolution. In addition, multigamma imagers combining PET with Compton imaging should be developed to enable multitracer imaging.
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Miller K. A backprojection kernel (KRNL3D) for very-wide-aperture 3D tomography applied to PET with Multigrid for precise use of time-of-flight data. Phys Med Biol 2021; 66. [PMID: 34673567 DOI: 10.1088/1361-6560/ac320a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 10/21/2021] [Indexed: 11/11/2022]
Abstract
In 'KRNL3D' we derive a kernel functionK(y1,y2,φ) whose backprojections from all directions (θ,φ) in the spherical band∣φ∣<φ¯maxon the celestial sphere, when integrated with respect to solid angle, yieldρ, the 3D Gaussian point response function (PRF) of radius 1. ThisK, when convolved against line integral data from an unknown density functionf, yields an integral formula for the 'mollification'ff=ρ∗f, which is a slightly blurred version off, and which stabilizes the mild ill-posedness. Applied to positron emission tomography that backprojection reconstruction occurs stochastically and one emission event at a time, after needed data corrections. We describe Octave (≈Matlab) codes to tabulateKand to test its use with a large apertureφ¯max=π/3orπ/6. 'KRNL3D-TOF' truncates backprojection to a cylindrical patch about the TOF approximate location of each event. These 'backplacements' decrease the computational cost and limit noise and streaking in one region from contaminating the reconstruction in more distant regions. They also retain the ability to count emission events in an isolated blob despiteverylow event counts, a valuable feature fordynamicstudies of metabolic processes. 'Multigrid' allows further reduction in the radius and lengths of the cylinders, thereby enabling even moreprecise use of the TOF information. This precision should be especially important as researchers decrease the TOF uncertainty in newer generation scanners. Finally, we discuss 'further work' that needs to be done. Our codes are being made freely available athttps://github.com/keithmillerberkeley/PET-codes.
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Affiliation(s)
- Keith Miller
- Department of Mathematics, University of California at Berkeley, Berkeley, CA 94720-3840, United States of America
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Ferino-Pérez A, Vélayoudom FL, Belia L, Glaude EL, Gaspard S, Jáuregui-Haza UJ. In silico development of new PET radiopharmaceuticals from mTOR inhibitors. J Mol Graph Model 2021; 111:108057. [PMID: 34847519 DOI: 10.1016/j.jmgm.2021.108057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 10/19/2022]
Abstract
Rapamycin (or sirolimus) is a macrolide that has shown to be useful as an immunosuppressant and that was studied in metabolic, neurological, or genetic disorders. Rapamycin is a specific natural inhibitor of the mechanistic target of rapamycin (mTOR) that is a kinase protein playing a pivotal role in cell growth and proliferation by activation of several metabolic processes. This work aimed to evaluate the utility of several compounds obtained from rapamycin and its semi-synthetic analogs everolimus and temsirolimus as possible radiopharmaceuticals oriented to this protein. Density Functional Theory calculations of these molecules were made and further analysis of the dual descriptor, charges populations, and of the electrostatic potential surfaces were performed. Molecular docking simulations were used to evaluate the interactions of the rapamycin with the studied candidates. They allowed us to propose two strategies for the synthesis of novel compounds based on electrophilic reactions. Molecular docking results also helped us to eliminate molecules that did not interact correctly with the target. Finally, we found for the first time, that the novel compounds synthesized through the electrophilic addition reaction that employed 18F-selectfluor, should maintain the biological activity of original compounds and could be suitable as Positron Emission Tomography radiopharmaceuticals targeting mTOR Complex1 system.
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Affiliation(s)
- Anthuan Ferino-Pérez
- Instituto Superior de Tecnologías y Ciencias Aplicadas (InSTEC), Universidad de La Habana, La Habana, CP 10600, Cuba
| | - Fritz-Line Vélayoudom
- Department of Endocrinology-Diabetology. University Hospital of Guadeloupe. 97139, Les Abymes, France; Inserm UMR1283, CNRS UMR8199, European Genomic Institute for Diabetes (EGID), Institut Pasteur de Lille, France.
| | - Lyonel Belia
- Department of Nuclear Medicine. University Hospital of Guadeloupe, 97139, Les Abymes, France
| | - Eddy-Laurent Glaude
- Department of Interventional and Diagnostic Radiology. University Hospital of Guadeloupe, 97139, Les Abymes, France
| | - Sarra Gaspard
- Laboratoire COVACHIMM2E, EA 3592, Université des Antilles, BP 250, 97159, Pointe-à-Pitre, Guadeloupe
| | - Ulises J Jáuregui-Haza
- Instituto Superior de Tecnologías y Ciencias Aplicadas (InSTEC), Universidad de La Habana, La Habana, CP 10600, Cuba; Instituto Tecnológico de Santo Domingo (INTEC), República Dominicana, France
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Hu Y, Liu G, Yu H, Wang Y, Li C, Tan H, Chen S, Gu J, Shi H. Feasibility of ultra-low 18F-FDG activity acquisitions using total-body PET/CT. J Nucl Med 2021; 63:959-965. [PMID: 34593593 DOI: 10.2967/jnumed.121.262038] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 09/09/2021] [Indexed: 11/16/2022] Open
Abstract
The present study aimed to evaluate the feasibility of ultra-low 18F-fluorodeoxyglucose (FDG) activity in total-body positron emission tomography (PET)/computed tomography (CT) oncological studies. Methods: Thirty patients with cancer were enrolled prospectively and underwent a total-body PET/CT examination with an ultra-low 18F-FDG activity (0.37 MBq/kg) after an uptake time of 60 minutes. Among the enrolled patients, 11 were diagnosed with colorectal cancer (CRC). PET raw data were acquired within 15 minutes and reconstructed using data from the first 1, 2, 4, 8, 10 and the entire 15 min (G1, G2, G4, G8, G10, G15). Image quality was assessed qualitatively by two readers using a 5-point Likert scale twice. Cohen's kappa test was performed to investigate the intra-reader and inter-reader agreement. The standard uptake value (SUV)max of lesions, SUVmax, SUVmean, and standard deviation (SD) of the livers, the tumor-to-background ratio (TBR), and the signal-to-noise ratio (SNR) were measured and compared. The acquisition time for a clinically acceptable image quality was determined using an ultra low activity injection. In a matched-pair study, 11 patients with CRC who received a full FDG activity (3.7 MBq/kg) with a 2-min PET acquisition were selected retrospectively with matched sex, height, weight, body mass index, glucose level, uptake time, and pathological types with the 11 CRC subjects in the prospective study. Qualitative and quantitative analyses were performed and compared between the 11 patients with CRC in the ultra-low activity group and their matched full activity controls. Results: Qualitative analysis of image quality showed good intra- and inter-reader agreements (all kappa > 0.7). All the images acquired for 8-min or longer scored over 3 (indicating clinical acceptability). There was no significant difference in TBR and liver SNR among all the images acquired for 8-min or longer. In the matched study, no significant difference was found in the image quality score and quantitative parameters between the ultra-low activity group with an 8-min acquisition and the full activity group with a 2-min acquisition. Conclusion: Ultra-low FDG activity injection with 8-min acquisition in a total-body PET/CT study can achieve acceptable image quality equivalent to that in the full activity group using 2-min acquisition.
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Affiliation(s)
- Yan Hu
- Department of Nuclear Medicine, Zhongshan Hospital, China
| | - Guobing Liu
- Department of Nuclear Medicine, Zhongshan Hospital, China
| | - Haojun Yu
- Department of Nuclear Medicine, Zhongshan Hospital, China
| | - Ying Wang
- Central Research Institute, United Imaging Healthcare, China
| | - Chenwei Li
- Central Research Institute, United Imaging Healthcare, China
| | - Hui Tan
- Department of Nuclear Medicine, Zhongshan Hospital, China
| | - Shuguang Chen
- Department of Nuclear Medicine, Zhongshan Hospital, China
| | - Jianying Gu
- Department of Plastic Surgery, Zhongshan Hospital, Fudan University, China
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Moskal P, Kowalski P, Shopa RY, Raczyński L, Baran J, Chug N, Curceanu C, Czerwiński E, Dadgar M, Dulski K, Gajos A, Hiesmayr BC, Kacprzak K, Kapłon Ł, Kisielewska D, Klimaszewski K, Kopka P, Korcyl G, Krawczyk N, Krzemień W, Kubicz E, Niedźwiecki S, Parzych S, Raj J, Sharma S, Shivani S, Stępień E, Tayefi F, Wiślicki W. Simulating NEMA characteristics of the modular total-body J-PET scanner-an economic total-body PET from plastic scintillators. Phys Med Biol 2021; 66. [PMID: 34289460 DOI: 10.1088/1361-6560/ac16bd] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 07/21/2021] [Indexed: 02/01/2023]
Abstract
The purpose of the presented research is estimation of the performance characteristics of the economic total-body Jagiellonian-PET system (TB-J-PET) constructed from plastic scintillators. The characteristics are estimated according to the NEMA NU-2-2018 standards utilizing the GATE package. The simulated detector consists of 24 modules, each built out of 32 plastic scintillator strips (each with cross section of 6 mm times 30 mm and length of 140 or 200 cm) arranged in two layers in regular 24-sided polygon circumscribing a circle with the diameter of 78.6 cm. For the TB-J-PET with an axial field-of-view (AFOV) of 200 cm, a spatial resolutions (SRs) of 3.7 mm (transversal) and 4.9 mm (axial) are achieved. The noise equivalent count rate (NECR) peak of 630 kcps is expected at 30 kBq cc-1. Activity concentration and the sensitivity at the center amounts to 38 cps kBq-1. The scatter fraction (SF) is estimated to 36.2 %. The values of SF and SR are comparable to those obtained for the state-of-the-art clinical PET scanners and the first total-body tomographs: uExplorer and PennPET. With respect to the standard PET systems with AFOV in the range from 16 to 26 cm, the TB-J-PET is characterized by an increase in NECR approximately by factor of 4 and by the increase of the whole-body sensitivity by factor of 12.6 to 38. The time-of-flight resolution for the TB-J-PET is expected to be at the level of CRT = 240 ps full width at half maximum. For the TB-J-PET with an AFOV of 140 cm, an image quality of the reconstructed images of a NEMA IEC phantom was presented with a contrast recovery coefficient and a background variability parameters. The increase of the whole-body sensitivity and NECR estimated for the TB-J-PET with respect to current commercial PET systems makes the TB-J-PET a promising cost-effective solution for the broad clinical applications of total-body PET scanners. TB-J-PET may constitute an economic alternative for the crystal TB-PET scanners, since plastic scintillators are much cheaper than BGO or LYSO crystals and axial arrangement of the strips significantly reduces the costs of readout electronics and SiPMs.
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Affiliation(s)
- P Moskal
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - P Kowalski
- Department of Complex Systems, National Centre for Nuclear Research, 05-400 Otwock-Świerk, Poland
| | - R Y Shopa
- Department of Complex Systems, National Centre for Nuclear Research, 05-400 Otwock-Świerk, Poland
| | - L Raczyński
- Department of Complex Systems, National Centre for Nuclear Research, 05-400 Otwock-Świerk, Poland
| | - J Baran
- Institute of Nuclear Physics Polish Academy of Sciences, 31-342 Cracow, Poland
| | - N Chug
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - C Curceanu
- INFN, Laboratori Nazionali di Frascati, I-00044 Frascati, Italy
| | - E Czerwiński
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - M Dadgar
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - K Dulski
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - A Gajos
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - B C Hiesmayr
- Faculty of Physics, University of Vienna, A-1090 Vienna, Austria
| | - K Kacprzak
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - Ł Kapłon
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - D Kisielewska
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - K Klimaszewski
- Department of Complex Systems, National Centre for Nuclear Research, 05-400 Otwock-Świerk, Poland
| | - P Kopka
- Department of Complex Systems, National Centre for Nuclear Research, 05-400 Otwock-Świerk, Poland
| | - G Korcyl
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - N Krawczyk
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - W Krzemień
- High Energy Physics Division, National Centre for Nuclear Research, 05-400 Otwock-Świerk, Poland
| | - E Kubicz
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - Sz Niedźwiecki
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - Sz Parzych
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - J Raj
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - S Sharma
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - S Shivani
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - E Stępień
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - F Tayefi
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348 Cracow, Poland.,Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, 30-348 Cracow, Poland
| | - W Wiślicki
- Department of Complex Systems, National Centre for Nuclear Research, 05-400 Otwock-Świerk, Poland
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Investigating ultra-low-dose total-body [18F]-FDG PET/CT in colorectal cancer: initial experience. Eur J Nucl Med Mol Imaging 2021; 49:1002-1011. [PMID: 34462790 DOI: 10.1007/s00259-021-05537-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/20/2021] [Indexed: 12/29/2022]
Abstract
PURPOSE This study was to evaluate the effects of an ultra-low dose of [18F]-FDG on the image quality of total-body PET/CT and its lesion detectability in colorectal cancer (CRC). METHODS Sixty-two CRC patients who underwent total-body PET/CT (uEXPLORER, United Imaging Healthcare, Shanghai, China) with an ultra-low dose (0.37 MBq/kg) of [18F]-FDG were enrolled in this retrospective study. The PET images were reconstructed with the entire 15-min dataset first and then split into 13-, 8-, 5-, 4-, 3-, 2-, and 1-min duration groups to simulate fast scanning images. For simplicity, the images reconstructed with the data from 15 to 1 min were referred to as G15, G13, and so on until G1. Subjective image quality was assessed with 5-point Likert scales. The objective image quality parameters included the SUVmax, SUVmean, and signal-to-noise ratio (SNR) of the liver and blood pool and the SUVmax and tumor-to-background ratio (TBR) of the lesions. G15 served as the control to evaluate lesion detectability. RESULTS A total of 62 patients (43 men, 19 women; age 41-88, mean ± SD 64.0 ± 10.9 years) with 64 CRC primary tumor lesions and 10 low-grade intraepithelial neoplasia (LGIN) lesions were enrolled in this study. The subjective scores were highest for G15 (4.5 ± 0.5) and then decreased from G13 (4.3 ± 0.4) to G8 (3.7 ± 0.5). The liver SNR increased with the extension of acquisition time from G8 (17.2 ± 2.8) to G13 (20.6 ± 3.4) and G15 (21.9 ± 3.4). The liver SNR of G8 was not significantly different from that of G13 (p = 0.15) and was significantly different from that of G15 (p = 0.001). All 64 CRC lesions could be identified in all image groups, even on G1. One of ten LGINs was missed on G1, G2, and G3, and one LGIN was missed on G1, G2, G3, and G4. G15 served as the control, and 100% (48/48) lymph nodes could be found on G13 and G8 compared to 93.8% (45/48) lymph nodes on G5 and G4, 85.4% (41/48) lymph nodes on G3, 81.3% (39/48) lymph nodes on G2, and 77.1% (37/48) lymph nodes on G1. For liver metastases, there were no missed liver lesions on G13 and G8 and 3, 4, 6, 7, and 9 missed liver lesions on G5, G4, G3, G2, and G1, respectively. For other areas of metastasis, including the lung, peritoneum, and ovaries, there were no missed lesions in any group. CONCLUSIONS Total-body PET/CT with an ultra-low dose of [18F]-FDG can maintain satisfactory image quality and lesion detectability in CRC.
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Lan X, Younis MH, Li K, Cai W. First clinical experience of 106 cm, long axial field-of-view (LAFOV) PET/CT: an elegant balance between standard axial (23 cm) and total-body (194 cm) systems. Eur J Nucl Med Mol Imaging 2021; 48:3755-3759. [PMID: 34424375 PMCID: PMC8381142 DOI: 10.1007/s00259-021-05505-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Xiaoli Lan
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. .,Hubei Key Laboratory of Molecular Imaging, Wuhan, China.
| | - Muhsin H Younis
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Ke Li
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Weibo Cai
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, WI, USA.
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Spencer BA, Berg E, Schmall JP, Omidvari N, Leung EK, Abdelhafez YG, Tang S, Deng Z, Dong Y, Lv Y, Bao J, Liu W, Li H, Jones T, Badawi RD, Cherry SR. Performance Evaluation of the uEXPLORER Total-Body PET/CT Scanner Based on NEMA NU 2-2018 with Additional Tests to Characterize PET Scanners with a Long Axial Field of View. J Nucl Med 2021; 62:861-870. [PMID: 33008932 PMCID: PMC8729871 DOI: 10.2967/jnumed.120.250597] [Citation(s) in RCA: 165] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/21/2020] [Indexed: 01/07/2023] Open
Abstract
The world's first total-body PET scanner with an axial field of view (AFOV) of 194 cm is now in clinical and research use at our institution. The uEXPLORER PET/CT system is the first commercially available total-body PET scanner. Here we present a detailed physical characterization of this scanner based on National Electrical Manufacturers Association (NEMA) NU 2-2018 along with a new set of measurements devised to appropriately characterize the total-body AFOV. Methods: Sensitivity, count-rate performance, time-of-flight resolution, spatial resolution, and image quality were evaluated following the NEMA NU 2-2018 protocol. Additional measurements of sensitivity and count-rate capabilities more representative of total-body imaging were performed using extended-geometry phantoms based on the world-average human height (∼165 cm). Lastly, image quality throughout the long AFOV was assessed with the NEMA image quality (IQ) phantom imaged at 5 axial positions and over a range of expected total-body PET imaging conditions (low dose, delayed imaging, short scan duration). Results: Our performance evaluation demonstrated that the scanner provides a very high sensitivity of 174 kcps/MBq, a count-rate performance with a peak noise-equivalent count rate of approximately 2 Mcps for total-body imaging, and good spatial resolution capabilities for human imaging (≤3.0 mm in full width at half maximum near the center of the AFOV). Excellent IQ, excellent contrast recovery, and low noise properties were illustrated across the AFOV in both NEMA IQ phantom evaluations and human imaging examples. Conclusion: In addition to standard NEMA NU 2-2018 characterization, a new set of measurements based on extending NEMA NU 2-2018 phantoms and experiments was devised to characterize the physical performance of the first total-body PET system. The rationale for these extended measurements was evident from differences in sensitivity, count-rate-activity relationships, and noise-equivalent count-rate limits imposed by differences in dead time and randoms fraction between the NEMA NU 2 70-cm phantoms and the more representative total-body imaging phantoms. Overall, the uEXPLORER PET system provides ultra-high sensitivity that supports excellent spatial resolution and IQ throughout the field of view in both phantom and human imaging.
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Affiliation(s)
- Benjamin A. Spencer
- Department of Biomedical Engineering, University of California–Davis, Davis, California,Department of Radiology, University of California–Davis, Davis, California
| | - Eric Berg
- Department of Biomedical Engineering, University of California–Davis, Davis, California
| | | | - Negar Omidvari
- Department of Biomedical Engineering, University of California–Davis, Davis, California
| | - Edwin K. Leung
- Department of Biomedical Engineering, University of California–Davis, Davis, California
| | | | | | - Zilin Deng
- United Imaging Healthcare, Shanghai, China
| | - Yun Dong
- United Imaging Healthcare, Shanghai, China
| | - Yang Lv
- United Imaging Healthcare, Shanghai, China
| | - Jun Bao
- United Imaging Healthcare, Shanghai, China
| | | | - Hongdi Li
- United Imaging Healthcare, Houston, Texas; and
| | - Terry Jones
- Department of Radiology, University of California–Davis, Davis, California
| | - Ramsey D. Badawi
- Department of Biomedical Engineering, University of California–Davis, Davis, California,Department of Radiology, University of California–Davis, Davis, California
| | - Simon R. Cherry
- Department of Biomedical Engineering, University of California–Davis, Davis, California,Department of Radiology, University of California–Davis, Davis, California
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Rowe SP, Solnes LB, Yin Y, Kitchen G, Lodge MA, Karakatsanis NA, Rahmim A, Pomper MG, Leal JP. Imager-4D: New Software for Viewing Dynamic PET Scans and Extracting Radiomic Parameters from PET Data. J Digit Imaging 2021; 32:1071-1080. [PMID: 31388864 DOI: 10.1007/s10278-019-00255-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Extensive research is currently being conducted into dynamic positron emission tomography (PET) acquisitions (including dynamic whole-body imaging) as well as extraction of radiomic features from imaging modalities. We describe a new PET viewing software known as Imager-4D that provides a facile means of viewing and analyzing dynamic PET data and obtaining associated quantitative metrics including radiomic parameters. The Imager-4D was programmed in the Java language utilizing the FX extensions. It is executable on any system for which a Java w/FX compliant virtual machine is available. The software incorporates the ability to view and analyze dynamic data acquired with different types of dynamic protocols. For image display, the program maintains a built-in library of 62 different lookup tables with monochromatic and full-color distributions. The Imager-4D provides multiple display layouts and can display fused images. Multiple methods of volume-of-interest (VOI) selection are available. Dynamic analysis features, such as image summation and full Patlak analysis, are also available. The user interface includes window width and level, blending, and zoom functionality. VOI sizes are adjustable and data from VOIs can either be displayed numerically or graphically within the software or exported. An example case of a 50-year-old woman with metastatic colorectal cancer and thyroiditis is included and demonstrates the steps for a user to obtain standard PET parameters, dynamic data, and radiomic features using selected VOIs. The Imager-4D represents a novel PET viewer that allows the user to view dynamic PET data, to derive dynamic and radiomic parameters from that data, and to combine dynamic data with radiomics ("dynomics"). The Imager-4D is available as a free download. This software has the potential to speed the adoption of advanced analysis of dynamic PET data into routine clinical use.
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Affiliation(s)
- Steven P Rowe
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 550 N. Broadway Suite 300, Baltimore, MD, 21205, USA. .,The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 601 N. Caroline JHOC 3233, Baltimore, MD, 21287, USA.
| | - Lilja B Solnes
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 550 N. Broadway Suite 300, Baltimore, MD, 21205, USA
| | - Yafu Yin
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 550 N. Broadway Suite 300, Baltimore, MD, 21205, USA.,Department of Nuclear Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Grant Kitchen
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, USA
| | - Martin A Lodge
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 550 N. Broadway Suite 300, Baltimore, MD, 21205, USA
| | - Nicolas A Karakatsanis
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 550 N. Broadway Suite 300, Baltimore, MD, 21205, USA.,Department of Radiology, Weill Cornell Medical College of Cornell University, New York, NY, USA
| | - Arman Rahmim
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 550 N. Broadway Suite 300, Baltimore, MD, 21205, USA.,Departments of Radiology and Physics, University of British Columbia, Vancouver, BC, Canada
| | - Martin G Pomper
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 550 N. Broadway Suite 300, Baltimore, MD, 21205, USA
| | - Jeffrey P Leal
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 550 N. Broadway Suite 300, Baltimore, MD, 21205, USA.
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Yang J, Sohn JH, Behr SC, Gullberg GT, Seo Y. CT-less Direct Correction of Attenuation and Scatter in the Image Space Using Deep Learning for Whole-Body FDG PET: Potential Benefits and Pitfalls. Radiol Artif Intell 2021; 3:e200137. [PMID: 33937860 PMCID: PMC8043359 DOI: 10.1148/ryai.2020200137] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 11/04/2020] [Accepted: 11/13/2020] [Indexed: 05/14/2023]
Abstract
PURPOSE To demonstrate the feasibility of CT-less attenuation and scatter correction (ASC) in the image space using deep learning for whole-body PET, with a focus on the potential benefits and pitfalls. MATERIALS AND METHODS In this retrospective study, 110 whole-body fluorodeoxyglucose (FDG) PET/CT studies acquired in 107 patients (mean age ± standard deviation, 58 years ± 18; age range, 11-92 years; 72 females) from February 2016 through January 2018 were randomly collected. A total of 37.3% (41 of 110) of the studies showed metastases, with diverse FDG PET findings throughout the whole body. A U-Net-based network was developed for directly transforming noncorrected PET (PETNC) into attenuation- and scatter-corrected PET (PETASC). Deep learning-corrected PET (PETDL) images were quantitatively evaluated by using the standardized uptake value (SUV) of the normalized root mean square error, the peak signal-to-noise ratio, and the structural similarity index, in addition to a joint histogram for statistical analysis. Qualitative reviews by radiologists revealed the potential benefits and pitfalls of this correction method. RESULTS The normalized root mean square error (0.21 ± 0.05 [mean SUV ± standard deviation]), mean peak signal-to-noise ratio (36.3 ± 3.0), mean structural similarity index (0.98 ± 0.01), and voxelwise correlation (97.62%) of PETDL demonstrated quantitatively high similarity with PETASC. Radiologist reviews revealed the overall quality of PETDL. The potential benefits of PETDL include a radiation dose reduction on follow-up scans and artifact removal in the regions with attenuation correction- and scatter correction-based artifacts. The pitfalls involve potential false-negative results due to blurring or missing lesions or false-positive results due to pseudo-low-uptake patterns. CONCLUSION Deep learning-based direct ASC at whole-body PET is feasible and potentially can be used to overcome the current limitations of CT-based approaches, benefiting patients who are sensitive to radiation from CT.Supplemental material is available for this article.© RSNA, 2020.
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Affiliation(s)
- Jaewon Yang
- From the Department of Radiology and Biomedical Imaging (J.Y., J.H.S., S.C.B., G.TG., Y.S.) and Physics Research Laboratory (J.Y., G.T.G., Y.S.), University of California, San Francisco, 185 Berry St, Suite 350, San Francisco, CA 94143-0946
| | - Jae Ho Sohn
- From the Department of Radiology and Biomedical Imaging (J.Y., J.H.S., S.C.B., G.TG., Y.S.) and Physics Research Laboratory (J.Y., G.T.G., Y.S.), University of California, San Francisco, 185 Berry St, Suite 350, San Francisco, CA 94143-0946
| | - Spencer C. Behr
- From the Department of Radiology and Biomedical Imaging (J.Y., J.H.S., S.C.B., G.TG., Y.S.) and Physics Research Laboratory (J.Y., G.T.G., Y.S.), University of California, San Francisco, 185 Berry St, Suite 350, San Francisco, CA 94143-0946
| | - Grant T. Gullberg
- From the Department of Radiology and Biomedical Imaging (J.Y., J.H.S., S.C.B., G.TG., Y.S.) and Physics Research Laboratory (J.Y., G.T.G., Y.S.), University of California, San Francisco, 185 Berry St, Suite 350, San Francisco, CA 94143-0946
| | - Youngho Seo
- From the Department of Radiology and Biomedical Imaging (J.Y., J.H.S., S.C.B., G.TG., Y.S.) and Physics Research Laboratory (J.Y., G.T.G., Y.S.), University of California, San Francisco, 185 Berry St, Suite 350, San Francisco, CA 94143-0946
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Ghabrial A, Franklin DR, Zaidi H. A Monte Carlo simulation study of scatter fraction and the impact of patient BMI on scatter in long axial field-of-view PET scanners. Z Med Phys 2021; 31:305-315. [PMID: 33593642 DOI: 10.1016/j.zemedi.2021.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 01/24/2021] [Accepted: 01/25/2021] [Indexed: 11/16/2022]
Abstract
The NEMA NU-2 standard describes a protocol for measurement of scatter fraction (SF) using an axially-aligned line source, offset at 45mm from the central axis, in a cylindrical polyethylene phantom. In this work, which is an extension of our preliminary results previuosly published in the Proceedings of IEEE NSS/MIC 2018 [1], we aim to evaluate the performance of the NEMA NU-2 SF protocol in a Siemens Biograph mCT PET/CT whole-body scanner and a long axial field-of-view (LAFOV) total-body PET scanner to determine whether modifications to the NEMA NU-2 SF protocol are needed for the characterisation of scatter in such scanners. In addition, we evaluate the impact of patient body mass index (BMI) on SF in a LAFOV scanner. The Siemens Biograph mCT and a typical LAFOV PET scanner were modelled in GATE. Monte Carlo simulations were performed to validate the mCT scanner model against published experimental results. SF was estimated using a modified NEMA NU-2 protocol with variable radial offsets on both scanners and compared to ground truth SF measurements obtained with a uniform-activity cylindrical phantom. Correlation between BMI and SF in the LAFOV scanner was evaluated by simulating anthropomorphic phantoms with different BMIs and realistic 18F-FDG distributions, together with uniformly-filled 200cm long cylindrical phantoms with equivalent effective diameters. The optimal offset was found to be either 60mm or 80mm, depending on the chosen optimality metric. We conclude that modifications to NEMA NU-2 are required for accurate SF characterisation in whole-body and LAFOV scanners. Finally, SF in anthropomorphic phantoms with realistic tissue concentrations of 18F-FDG was found to be strongly correlated with SF in an equivalent-volume cylindrical phantom for the LAFOV PET scanner; BMI was also found to strongly positively correlate with the SF.
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Affiliation(s)
- Amir Ghabrial
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva, Switzerland; University of Technology Sydney, Ultimo NSW 2007, Australia
| | | | - 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, DK-500 Odense, Denmark
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42
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Lan X, Fan K, Li K, Cai W. Dynamic PET imaging with ultra-low-activity of 18F-FDG: unleashing the potential of total-body PET. Eur J Nucl Med Mol Imaging 2021; 48:4138-4141. [PMID: 33515054 DOI: 10.1007/s00259-021-05214-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Xiaoli Lan
- Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
- Hubei Key Laboratory of Molecular Imaging, Wuhan, China.
| | - Kevin Fan
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI, USA
| | - Ke Li
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI, USA
| | - Weibo Cai
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI, USA.
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43
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Ultra-low-activity total-body dynamic PET imaging allows equal performance to full-activity PET imaging for investigating kinetic metrics of 18F-FDG in healthy volunteers. Eur J Nucl Med Mol Imaging 2021; 48:2373-2383. [PMID: 33479842 DOI: 10.1007/s00259-020-05173-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 12/20/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE To investigate the feasibility of ultra-low-activity total-body positron emission tomography (PET) dynamic imaging for quantifying kinetic metrics of 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) in normal organs and to verify its clinical relevance with full-activity imaging. METHODS Dynamic total-body PET imaging was performed in 20 healthy volunteers, with eight using full activity (3.7 MBq/kg) of 18F-FDG and 12 using 10× activity reduction (0.37 MBq/kg). Image contrast, in terms of liver-to-muscle ratio (LMR), liver-to-blood ratio (LBR), and blood-to-muscle ratio (BMR) of radioactivity concentrations were assessed. A two-tissue compartment model was fitted to the time-to-activity curves in organs based on regions of interest (ROIs) delineation using PMOD, and constant rates (k1, k2, and k3) were generated. Kinetic constants, corresponding coefficients of variance (CoVs), image contrast, radiation dose, prompt counts, and data size were compared between full- and low-activity groups. RESULTS All constant rates, corresponding CoVs, and image contrast in different organs were comparable with none significant differences between full- and ultra-low-activity groups. PET images in the ultra-low-activity group generated significantly lower effective radiation dose (median, 0.419 vs. 4.886 mSv, P < 0.001), reduced prompt counts (median, 2.79 vs. 55.68 billion, P < 0.001), and smaller data size (median, 71.11 vs. 723.18 GB, P < 0.001). CONCLUSION Total-body dynamic PET imaging using 10× reduction of injected activity could achieve relevant kinetic metrics of 18F-FDG and comparable image contrast with full-activity imaging. Activity reduction results in significant decrease of radiation dose and data size, rendering it more acceptable and easier for data reconstruction, transmission, and storage for clinical practice.
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Abstract
Total-body PET image reconstruction follows a similar procedure to the image reconstruction process for standard whole-body PET scanners. One unique aspect of total-body imaging is simultaneous coverage of the entire human body, which makes it convenient to perform total-body dynamic PET scans. Therefore, four-dimensional dynamic PET reconstruction and parametric imaging are of great interest in total-body imaging. This article covers some basics of PET image reconstruction and then focuses on three- and four-dimensional PET reconstruction for total-body imaging. Methods for image formation from raw measurements in total-body PET are described. Challenges and opportunities in total-body PET image reconstruction are discussed.
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Affiliation(s)
- Jinyi Qi
- Department of Biomedical Engineering, University of California, One Shields Avenue, Davis, CA 95616, USA.
| | - Samuel Matej
- Department of Radiology, University of Pennsylvania, 3620 Hamilton Walk, John Morgan Building, Room 156A, Philadelphia, PA 19104-6061, USA
| | - Guobao Wang
- Department of Radiology, University of California Davis Medical Center, Lawrence J. Ellison Ambulatory Care Center Building, Suite 3100, 4860 Y Street, Sacramento, CA 95817, USA
| | - Xuezhu Zhang
- Department of Biomedical Engineering, University of California, One Shields Avenue, Davis, CA 95616, USA
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Viswanath V, Chitalia R, Pantel AR, Karp JS, Mankoff DA. Analysis of Four-Dimensional Data for Total Body PET Imaging. PET Clin 2021; 16:55-64. [PMID: 33218604 PMCID: PMC8722496 DOI: 10.1016/j.cpet.2020.09.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The high sensitivity and total-body coverage of total-body PET scanners will be valuable for a number of clinical and research applications outlined in this article.
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Affiliation(s)
- Varsha Viswanath
- Department of Radiology, University of Pennsylvania, John Morgan Building, 3620 Hamilton Walk, Room 150, Philadelphia, PA 19103, USA.
| | - Rhea Chitalia
- Department of Radiology, University of Pennsylvania, Richards Building, 3700 Hamilton Walk, Room D700, Philadelphia, PA 19103, USA
| | - Austin R Pantel
- Department of Radiology, University of Pennsylvania, Hospital of the University of Pennsylvania, 1 Donner Building, 3400 Spruce Street, Philadelphia, PA 19104-4283, USA
| | - Joel S Karp
- Department of Radiology, University of Pennsylvania, John Morgan Building, 3620 Hamilton Walk, Room 150, Philadelphia, PA 19103, USA
| | - David A Mankoff
- Department of Radiology, Abramson Cancer Center, University of Pennsylvania, Hospital of the University of Pennsylvania, 1 Donner Building, 3400 Spruce Street, Philadelphia, PA 19104-4283, USA
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Raczyński L, Wiślicki W, Klimaszewski K, Krzemień W, Kopka P, Kowalski P, Shopa R, Bała M, Chhokar J, Curceanu C, Czerwiński E, Dulski K, Gajewski J, Gajos A, Gorgol M, Del Grande R, Hiesmayr B, Jasińska B, Kacprzak K, Kapłon L, Kisielewska D, Korcyl G, Kozik T, Krawczyk N, Kubicz E, Mohammed M, Niedźwiecki S, Pałka M, Pawlik-Niedźwiecka M, Raj J, Rakoczy K, Ruciński A, Sharma S, Shivani S, Silarski M, Skurzok M, Stepień E, Zgardzińska B, Moskal P. 3D TOF-PET image reconstruction using total variation regularization. Phys Med 2020; 80:230-242. [DOI: 10.1016/j.ejmp.2020.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 10/09/2020] [Accepted: 10/14/2020] [Indexed: 12/31/2022] Open
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Chondronikola M, Sarkar S. Total-body PET Imaging: A New Frontier for the Assessment of Metabolic Disease and Obesity. PET Clin 2020; 16:75-87. [PMID: 33160928 DOI: 10.1016/j.cpet.2020.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Obesity and associated metabolic syndrome are a global public health issue. Understanding the pathophysiology of this systemic disease is of critical importance for the development of future therapeutic interventions to improve clinical outcomes. The multiorgan nature of the pathophysiology of obesity presents a unique challenge. Total-body PET imaging, either static or dynamic, provides a vital set of tools to study organ crosstalk. The visualization and quantification of tissue metabolic kinetics with total-body PET in health and disease provides essential information to better understand disease physiology and potentially develop diagnostic and therapeutic modalities.
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Affiliation(s)
- Maria Chondronikola
- Department of Nutrition, University of California Davis, One Shields Avenue, Davis, CA 95616, USA; Harokopio University of Athens, El Venizelou 70, Kallithea 17676, Greece
| | - Souvik Sarkar
- Harokopio University of Athens, El Venizelou 70, Kallithea 17676, Greece; Division of Gastroenterology and Hepatology, University of California Davis, Davis, CA, USA.
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Høilund-Carlsen PF, Piri R, Gerke O, Edenbrandt L, Alavi A. Assessment of Total-Body Atherosclerosis by PET/Computed Tomography. PET Clin 2020; 16:119-128. [PMID: 33160930 DOI: 10.1016/j.cpet.2020.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Atherosclerotic burden has become the focus of cardiovascular risk assessment. PET/computed tomography (CT) imaging with the tracers 18F-fluorodeoxyglucose and 18F-sodium fluoride shows arterial wall inflammation and microcalcification, respectively. Arterial uptake of both tracers is modestly age dependent. 18F-sodium fluoride uptake is consistently associated with risk factors and more easily measured in the heart. Because of extremely high sensitivity, ultrashort acquisition, and minimal radiation to the patient, total-body PET/CT provides unique opportunities for atherosclerosis imaging: disease screening and delayed and repeat imaging with global disease scoring and parametric imaging to better characterize the atherosclerosis of individual patients.
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Affiliation(s)
- Poul Flemming Høilund-Carlsen
- Department of Nuclear Medicine, Odense University Hospital, Kløvervænget 47, 5000 Odense C, Denmark; Department of Clinical Research, University of Southern Denmark, 5000 Odense C, Denmark.
| | - Reza Piri
- Department of Nuclear Medicine, Odense University Hospital, Kløvervænget 47, 5000 Odense C, Denmark; Department of Clinical Research, University of Southern Denmark, 5000 Odense C, Denmark
| | - Oke Gerke
- Department of Nuclear Medicine, Odense University Hospital, Kløvervænget 47, 5000 Odense C, Denmark; Department of Clinical Research, University of Southern Denmark, 5000 Odense C, Denmark
| | - Lars Edenbrandt
- Department of Clinical Physiology, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Molecular and Clinical Medicine, Institute of Medicine, SU Sahlgrenska, 41345 Göteborg, Sweden
| | - Abass Alavi
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, 3400 Spruce Street, PA 19104, USA
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Daube-Witherspoon ME, Viswanath V, Werner ME, Karp JS. Performance Characteristics of Long Axial Field-of-View PET Scanners with Axial Gaps. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2020; 5:322-330. [PMID: 34179595 DOI: 10.1109/trpms.2020.3027257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The introduction of long (>60 cm) axial field-of-view (LAFOV) PET systems has shown their potential for clinical and research applications. LAFOV scanners are expensive, so there is interest in designing systems with longer axial coverage while mitigating cost by introducing detector gaps. We used measurements on the PennPET Explorer (64-cm AFOV prototype) and simulations of scanners up to 143-cm long to assess scanner performance with axial gaps introduced by varying the number of detector rows in each ring. Removing detectors reduces the total sensitivity and results in a non-uniform axial noise profile. Axial resolution shows small (<0.5 mm) loss from the edge of the AFOV to the center, even for a 143-cm AFOV scanner with an unrestricted acceptance angle. The presence of large axial gaps increases the variability in axial resolution and contrast recovery across the AFOV compared to a system without gaps. More modest axial gaps show less variable behavior. The results suggest that designs where the gap is no larger than one-half of the width of a detector ring may be preferred, although the optimal choice of scanner design with the trade-offs of performance and AFOV will depend on its intended usage.
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Affiliation(s)
| | - Varsha Viswanath
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Matthew E Werner
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Joel S Karp
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 USA
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