IEEE Transactions on Radiation and Plasma Medical Sciences最新文献

{"title":"Implementation of Photonic Crystals Into Davis LUT Module for GATE Simulation","authors":"Xuzhi He;Carlotta Trigila;Emilie Roncali","doi":"10.1109/TRPMS.2024.3501373","DOIUrl":"https://doi.org/10.1109/TRPMS.2024.3501373","url":null,"abstract":"The performance of positron emission tomography (PET) detectors has been constrained by the photodetector collection of optical photons emitted in the scintillator, which was limited to photons reaching the exit surface with an angle larger than the critical angle. Photonic crystals (PhCs) are periodic nanostructures with sizes comparable to the optical photons’ wavelengths, which can break through the critical angle limit. Thorough experimental investigation of PhCs effect on optical harvest in scintillator detectors is complex and costly. Simulation can overcome these challenges. Mainstream software, such as GATE does not support PhCs simulation. Here, we generalize the GATE optical model by incorporating the PhCs optical model into the look-up table (LUT) Davis model. We can model the performance of advanced scintillator detectors via the generalized LUT Davis model. The scintillator and PhCs materials tested in this work were lutetium oxyorthosilicate and titanium dioxide, respectively. Scintillators with a cross section of <inline-formula> <tex-math>$3times 3$ </tex-math></inline-formula> mm2 or <inline-formula> <tex-math>$10times 10$ </tex-math></inline-formula> mm2 and a thickness varying from 9 to 18 mm with a step size of 3 mm were modeled with a PhCs interface to the photodetector. Among the 4 tested PhCs configurations, the best optical photon harvest was improved by 62.4% compared to traditional coupling with variable results between PhCs structures. The energy resolution only slightly improved. We thus investigated the angular distribution of collected optical photons, which can guide the optimization of photodetectors’ detection efficiency at specific angles.","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"9 3","pages":"269-276"},"PeriodicalIF":4.6,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10756607","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Fast Plastic Scintillator for Low-Intensity Proton Beam Monitoring","authors":"A. Andrè;C. Hoarau;Y. Boursier;A. Cherni;M. Dupont;L. Gallin Martel;M.-L. Gallin Martel;A. Garnier;J. Hèrault;J.-P. Hofverberg;P. Kavrigin;C. Morel;J.-F Muraz;M. Pinson;G. Tripodo;D. Maneval;S. Marcatili","doi":"10.1109/TRPMS.2024.3498959","DOIUrl":"https://doi.org/10.1109/TRPMS.2024.3498959","url":null,"abstract":"In the context of particle therapy monitoring, we are developing a gamma-ray detector to determine the ion range in vivo from the measurement of particle time of flight. For this application, a beam monitor capable to tag in time the incident ion with a time resolution below 235-ps full width at half maximum (FWHM) (100-ps rms) is required to provide a start signal for the acquisition. We have therefore developed a dedicated detector based on a fast organic scintillator (EJ-204) of <inline-formula> <tex-math>$25times 25times $ </tex-math></inline-formula>1 mm3 coupled to four silicon photomultiplier strips that allow measuring the particle incident position by scintillation light sharing. The prototype was characterized with single protons of energies between 63 and 225 MeV at the MEDICYC and ProteusONE facilities of the Antoine Lacassagne proton therapy center in Nice. We obtained a time resolution of 120-ps FWHM at 63 MeV, and a spatial resolution of ~2-mm rms for single particles. Two identical detectors also allowed to measure the MEDICYC proton energy with 0.3% accuracy.","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"9 3","pages":"382-387"},"PeriodicalIF":4.6,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical and Deep-Learned Evaluation of MR-Guided Self-Supervised PET Reconstruction","authors":"Jessica B. Hopson;Sam Ellis;Anthime Flaus;Colm J. McGinnity;Radhouene Neji;Andrew J. Reader;Alexander Hammers","doi":"10.1109/TRPMS.2024.3496779","DOIUrl":"10.1109/TRPMS.2024.3496779","url":null,"abstract":"Reduced dose positron emission tomography (PET) lowers the radiation dose to patients and reduces costs. Lower-count data, however, degrades reconstructed image quality. Advanced reconstruction methods help mitigate image quality losses, but it is important to assess the resulting images from a clinical perspective. Two experienced clinicians assessed four PET reconstruction algorithms for [18F]FDG brain data, compared to a clinical standard reference (maximum-likelihood expectation-maximization (MLEM)), based on seven clinical image quality metrics: global quality rating, pattern recognition, diagnostic confidence (all on a scale of 0–4), sharpness, caudate-putamen separation (CP), noise, and contrast (on a scale between 0–2). The reconstruction methods assessed were a guided and unguided version of self-supervised maximum a posteriori EM (MAPEM) (where the guidance case used the patient’s MR image to control the smoothness penalty). For 3 of the 11 patient datasets reconstructed, post-smoothed versions of the MAPEM reconstruction were also considered, where the smoothing was with the point-spread-function used in the resolution modelling. Statistically significant improvements were observed in sharpness, CP, and contrast for self-supervised MR-guided MAPEM compared to MLEM. For example, MLEM scored between 1-1.1 out of 2 for sharpness, CP, and contrast, whereas self-supervised MR-guided MAPEM scored between 1.5-1.75. In addition to the clinical evaluation, pretrained convolutional neural networks (CNNs) were used to assess the image quality of a further 62 images. The CNNs demonstrated similar trends to the clinician, showing their potential as automated standalone observers. Both the clinical and CNN assessments suggest when using only 5% of the standard injected dose, self-supervised MR-guided MAPEM reconstruction matches the 100% MLEM case for overall performance. This makes the images far more clinically useful than standard MLEM.","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"9 3","pages":"337-346"},"PeriodicalIF":4.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143504796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Time-Walk and Timing-Shift Correction Method for Dual-Ended Readout TOF-DOI PET Detectors","authors":"Haibo Wang;Jiahao Xie;Jinyi Qi;Simon R. Cherry;Junwei Du","doi":"10.1109/TRPMS.2024.3497774","DOIUrl":"https://doi.org/10.1109/TRPMS.2024.3497774","url":null,"abstract":"Positron emission tomography (PET) detectors suffer from time-walk when the leading edge discriminator is employed for timing pick-off as well as a timing-shift when thick crystals are utilized due to the depth-of-interaction (DOI) effect. In this study, a combined time-walk and timing-shift correction method was proposed for dual-ended readout PET detectors. To evaluate the proposed method, a pair of dual-ended readout PET detectors was constructed. Each detector was based on two Hamamatsu S14161-3050-08 silicon photomultiplier (SiPM) arrays coupled to both ends of an <inline-formula> <tex-math>$8times 8$ </tex-math></inline-formula> arrays of <inline-formula> <tex-math>$3.1times 3.1times 20~{mathrm { mm}}^{3}$ </tex-math></inline-formula> lutetium-yttrium oxyorthosilicate crystals with a 3.2-mm pitch. By employing the relationship between the energies and detected time differences of events, the time-walk and timing-shift were effectively corrected. The coincidence time resolution of the two detectors improved from <inline-formula> <tex-math>$260.7~pm ~1.0$ </tex-math></inline-formula> ps to <inline-formula> <tex-math>$229.4~pm ~1.0$ </tex-math></inline-formula> ps when a 400–650 keV energy window was used to select events. These results demonstrate the effectiveness of the proposed time-walk and timing-shift correction method.","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"9 3","pages":"277-283"},"PeriodicalIF":4.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Energy-Based Scatter Estimation Using Energy Spectra Modification in PET","authors":"Ang Li;Bingxuan Li;Lei Fang;Xiaoyun Zhou;Qingguo Xie;Peng Xiao","doi":"10.1109/TRPMS.2024.3495219","DOIUrl":"https://doi.org/10.1109/TRPMS.2024.3495219","url":null,"abstract":"Energy-based scatter estimation methods have illustrated promising results in recent literature. Accurate estimation of energy probability density function of scattered photons (PDF-SC) is essential for precise scatter estimation and avoiding bias in reconstructed images. This article presents a novel method, referred to as energy spectra modification (ESM), to precisely estimate position-dependent local PDF-SC, which improves the accuracy of scatter estimation. ESM involves an iterative process to deblur local energy spectra, with the starting point constructed using an initial PDF-SC derived from global energy spectra. The scattered component of the deblurred energy spectrum is reblurred and normalized to estimate the local PDF-SC. We validated this approach through Monte Carlo simulations using a bladder phantom, an image quality phantom, and a cylindrical phantom. Comparative analyses were conducted against the traditional method employing global PDF-SC, a recent advancement, and the single scatter simulation method. The results demonstrated that our method effectively reduced activity bias of the global PDF-SC approach across various energy resolutions, windows, target size, and count levels. It achieved this with a comparable computational load and without hyperparameter modification.","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"9 3","pages":"347-361"},"PeriodicalIF":4.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Demonstration of LGADs and Cherenkov Gamma Detectors for Prompt Gamma Timing Proton Therapy Range Verification","authors":"Ryan Heller;Justin Ellin;Michael Backfish;Joshua W. Cates;Woon-Seng Choong;Nicolaus Kratochwil;Eric Prebys;Leonor Rebolo;Sara St. James;Gerard Ariño-Estrada","doi":"10.1109/TRPMS.2024.3494720","DOIUrl":"https://doi.org/10.1109/TRPMS.2024.3494720","url":null,"abstract":"The great potential for precision dose delivery with proton therapy remains to be fully exploited, largely due to uncertainties in range that require additional conservative treatment margins. Analysis of time distributions from prompt gamma-ray emissions offers a means to precisely verify the range in real time and shrink treatment margins, thus increasing effectiveness and reducing toxicity. We demonstrate a prototype prompt gamma timing system to detect proton range shifts, based on low gain avalanche detectors, used to time incoming protons, and Cherenkov detectors, to time the outgoing prompt gammas. With this system, we are able to detect range shifts induced in a PMMA phantom with about 1 mm precision consistently.","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"9 4","pages":"508-514"},"PeriodicalIF":4.6,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10748344","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gamma-Ray Position-of-Interaction Estimation in a Thick Monolithic LaBr3 Detector Using Artificial Neural Networks","authors":"T. Ferri;F. Rosellini;A. Caracciolo;G. Borghi;M. Carminati;F. Camera;A. Giaz;C. Fiorini","doi":"10.1109/TRPMS.2024.3492674","DOIUrl":"https://doi.org/10.1109/TRPMS.2024.3492674","url":null,"abstract":"Monolithic gamma-ray detectors can be used in single photon emission computed tomography systems for monitoring the delivered dose during boron neutron capture therapy treatments. Gamma-ray hit localization in thick monolithic scintillator crystals is a challenging task due to internal reflections and Compton scattering. Existing methods like the center of gravity (CoG) are susceptible to reconstruction uncertainties at the crystal edges, while approaches, including nonlinear analytical and statistical models, such as the maximum-likelihood, require significant computational resources. Artificial neural networks (ANNs) offer significant improvements in terms of accuracy and computational speed. In this study, we develop a supervised ANN regression algorithm for real-time position reconstruction in a thick square lanthanum bromide crystal [LaBr<inline-formula> <tex-math>$_{3}(text {Ce}+text {Sr})$ </tex-math></inline-formula>] with <inline-formula> <tex-math>$5, text {cm}times 5,text {cm}times 2,text {cm}$ </tex-math></inline-formula> dimensions, coupled with an <inline-formula> <tex-math>$8times 8$ </tex-math></inline-formula> matrix of silicon photomultipliers. The implemented neural network was trained and tested using calibration data acquired irradiating the crystal with a collimated 137Cs source (pencil-beam irradiation). The detector in combination with the ANN model achieves a positioning accuracy for single-gamma-ray events of approximately 2.6 mm in the central region, evaluated as the full width at half maximum (FWHM) of the prediction error distribution, slightly worsening toward the edges. The imaging capabilities of the detector in combination with a channel-edge pinhole collimator were then evaluated by acquiring images of a movable uncollimated 137Cs point source. The source was shifted in nine different positions at 3 mm distance from each other and the resolution of the system was evaluated fitting the images with a Gaussian curve. An image spatial resolution of around 8 mm FWHM was obtained, dominated as expected by the collimator geometry, with an accuracy of 0.7 mm in estimating the position of the point source.","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"9 3","pages":"284-295"},"PeriodicalIF":4.6,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10745622","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IEEE Transactions on Radiation and Plasma Medical Sciences Publication Information","authors":"","doi":"10.1109/TRPMS.2024.3475531","DOIUrl":"https://doi.org/10.1109/TRPMS.2024.3475531","url":null,"abstract":"","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"8 8","pages":"C3-C3"},"PeriodicalIF":4.6,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10744627","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IEEE Transactions on Radiation and Plasma Medical Sciences Information for Authors","authors":"","doi":"10.1109/TRPMS.2024.3475533","DOIUrl":"https://doi.org/10.1109/TRPMS.2024.3475533","url":null,"abstract":"","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"8 8","pages":"C2-C2"},"PeriodicalIF":4.6,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10744626","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dedicated 3D-Printed Radioactive Phantoms With ¹⁸F-FDG for Ultrahigh-Resolution PET","authors":"Ezzat Elmoujarkach;Steven Seeger;Luise Morgner;Fabian Schmidt;Julia G. Mannheim;Christian L. Schmidt;Magdalena Rafecas","doi":"10.1109/TRPMS.2024.3483233","DOIUrl":"https://doi.org/10.1109/TRPMS.2024.3483233","url":null,"abstract":"This study explores the potential of digital light processing to 3-D print radioactive phantoms for high-resolution positron emission tomography (PET). Using a slightly modified desktop 3-D printer and mixtures of 18F-FDG (T1/2: 109.8 min) and photopolymer resin, we have printed standardized and custom radioactive objects designed for ultrahigh-resolution PET, also as a first step toward complex geometries. The phantoms were: a flood source to assess uniformity, a two-point phantom for spatial resolution assessment, a multiline phantom for validating submillimeter printing resolution, a fish-like phantom with different activity concentrations, and a 50%-downscaled micro-PET image quality phantom (National Electrical Manufacturers Association NU 4-2008). Positron range effects were examined on the latter using a removable cover. The evaluation relied on planar images from a phosphor imager and tomographic images from a commercial small animal PET scanner. We were able to print radioactive uniform distributions with relative standard deviation below 4.5% and structures as small as 0.3 mm. Our two-point phantom outperformed a commercial one in terms of peak difference (6% versus 72%) and peak-to-valley ratio (75.3 versus 14.1). The fish-like phantom shows that printing hot regions and air cavities onto a uniform background is feasible. Future steps include using longer-lived radionuclides like 89Zr and 22Na.","PeriodicalId":46807,"journal":{"name":"IEEE Transactions on Radiation and Plasma Medical Sciences","volume":"9 3","pages":"362-371"},"PeriodicalIF":4.6,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10742298","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}