2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)最新文献

{"title":"Monte-Carlo simulations for an endoscopic time-of-flight PET detector","authors":"M. Zvolsky, A. Cserkaszky, G. Cucciati, E. Garutti, B. Frisch","doi":"10.1109/NSSMIC.2014.7430753","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430753","url":null,"abstract":"The EndoTOFPET-US collaboration develops a novel multimodal device for Ultrasound (US) Endoscopy and Positron Emission Tomography (PET) for detecting and quantifying novel morphologic and functional biomarkers for pancreas and prostate oncology. The detector is based on scintillating crystals with Silicon Photomultiplier (SiPM) read-out, aiming at a time of flight coincidence time resolution of 200 ps and a spatial resolution of ≈ 1 mm to allow for more sensitive, more precise and lower radiation-dose imaging than whole-body devices. We develop a framework, which is built around the Geant4-based simulation toolkit GAMOS, to simulate and reconstruct realistic imaging scenarios with this asymmetric PET detector. Both attenuation and activity DICOM data from e.g. PET/CT scans can be incorporated as phantoms in the simulations. The framework takes care of distributing jobs on a computing grid which is crucial for running large-scale simulations on voxelised phantoms. A set of studies on simple simulated phantoms quantifies the influence of acquisition time and detector movement on the spatial image resolution and overall image quality. A scan time of approx. 10 min and small rotation of around 10° yields a sufficient image quality. We further present qualitative studies of the expected performance of the EndoTOFPET-US detector using voxelised patient PET/CT DICOM datasets. The studies suggest that the endoscopic approach is able to separate the prostatic lesion well from the background radiation from prostate and bladder.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123304090","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":"PET image reconstruction with correction for non-periodic deformable motion!","authors":"I. Klyuzhin, G. Stortz, V. Sossi","doi":"10.1109/NSSMIC.2014.7431026","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7431026","url":null,"abstract":"Image reconstruction techniques that use rectangular basis functions (pixels and voxels) may not be optimal when non-periodic, deformable motion correction is required. Here we propose a new approach to PET image reconstruction and non-rigid motion correction that is based on representing the imaged objects with regularized, spatially bounded sets of disconnected points. Motion correction is performed by explicitly incorporating the object motion into the reconstruction algorithm, though the dynamically adjusted coordinates of the points. Within the proposed approach, the images are reconstructed iteratively in list-mode, and the system matrix calculation is based on the localized estimation of the probabilistic weights for every point in the generated point set, using an optimized point search algorithm. To validate the motion correction, a digital phantom of a freely moving mouse was generated using mesh deformation operators such as armatures and curve modifiers. From the simulated PET list-mode data and a priori known motion trajectory, we reconstructed 3D images corrected for deformable, non-periodic motion without using the traditional gate-based methods. In addition, the stability of the reconstructed images with respect to the point set parameters and deformations was investigated.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123085833","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":"Performances of Principal Component Analysis for the extraction of respiratory signal from Time-of-Flight PET coincidences stream","authors":"L. Presotto, E. De Bernardi, M. Gilardi, L. Gianolli, V. Bettinardi","doi":"10.1109/NSSMIC.2014.7430956","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430956","url":null,"abstract":"Recently Principal Component Analysis (PCA) was suggested as a potential way to extract motion signals (e.g: cardiac beat and respiratory signals) from the coincidences stream of the PET scan. Proofs of principle ensued. Aim: To assess minimum requirements of the signal for PCA to successfully recover it, in terms of temporal resolution, of total counts needed and of strength of the motion signal in the data. The use of Time-Of-Flight technology, to increase signal-to-background ratio was investigated to see whether it would give improved results. Materials and methods: A General Electrics Medical Systems Discovery-690 PET/CT was used. A phantom with an uniform background and hot spherical sources placed on a moving platform was used. Motion period was set to about 4 seconds and motion range at 10 mm and 20 mm. The motion was recorded with an RPM device. PCA was applied to obtain motion signals with 80, 160 and 320 ms sampling. It was applied to data relative to 327, 163, 81 and 41 seconds of total acquisition time. The correlation to the RPM signal, which for this phantom is virtually noiseless, was used to measure the power of PCA signal to be an effective indicator of the motion signal. PCA was applied to TOF, traditional non-TOF data and non-TOF data with a rejection for all events with a time signature indicating events outside a 40 cm diameter. Data were also analyzed for a cardiac scan of a patient, with samplings of 20, 40 and 80 ms, to try to recover both cardiac and respiratory signal. Results: Correlation coefficients of 0.80 or greater were found in all cases for the phantom with 20 mm motion. For the 10 mm motion markedly lower correlations are found. At 80 ms temporal resolution the correlations are too low or absent to allow motion signal extraction. High enough values (r>0.7) are found only at 320 ms sampling for 81 s (or longer) acquisitions or at 160 ms sampling for 327 s acquisitions. The use of TOF data did not improve results for this, relatively small, phantom. Nonetheless exploiting TOF to improve rebinning resolution and to reject random coincidences improved a bit the results.In the example patient analyzed both the cardiac and the respiratory signal could be extracted at 20 ms sampling with 2 minutes of total duration Conclusion: Principal Component Analysis proved to be effective as a tool to extract motion signal from PET coincidences stream. Sampling durations as fast as 160 ms for respiratory signals with few moving objects in the Field of View or 40 ms sampling for dual motion extraction with large motion signals in the FOV are feasible.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122205939","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":"Quantitative performance of iterative algorithms, with and without PSF and TOF, in the conditions of a dynamic cardiac 13N-ammonia study","authors":"L. Presotto, E. De Bernardi, L. Gianolli, M. Gilardi, V. Bettinardi","doi":"10.1109/NSSMIC.2014.7430837","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430837","url":null,"abstract":"Iterative reconstruction algorithm are the standard reconstruction for clinical imaging. For quantification purposes in kinetic modelling sometimes analytical reconstruction are preferred for their linearity and the absence of bias at the low statistics typical of dynamic studies. Time-Of-Flight (TOF) technology was suggested to be able to improve the efficacy of random coincidences correction, to reduce noise and should be able to reduce bias. Point Spread Function modelling (PSF) can also improve quantification accuracy recovery resolution degrading effects.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121153458","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":"Development of a SiPM-based Anger camera for INSERT, a new multi-modality SPECT/MRI system for preclinical and clinical imaging","authors":"P. Busca, C. Fiorini, A. D. Butt, M. Occhipinti, R. Quaglia, P. Trigilio, K. Nagy, T. Bukki, M. Czeller, Z. Nyitrai, C. Piemonte, F. Acerbi, A. Ferri, J. Rieger","doi":"10.1109/NSSMIC.2014.7430774","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430774","url":null,"abstract":"A new multi-modality imaging tool is under development in the framework of the INSERT (INtegrated SPECT/MRI for Enhanced Stratification in Radio-chemoTherapy) project, supported by the European Community. A custom SPECT apparatus, used as an insert for commercially available MRI systems, could enhance the treatment of brain tumors (primarily glioma) by offering more effective and earlier diagnosis with potentially better outcome in survival. In this work we briefly describe the architecture of the gamma-ray photo-detection module with focus on the Silicon PhotoMultiplier (SiPM) detectors and their performance with low-energy gamma-rays (57Co - 122 keV). The camera has a 50.40 mm × 51.70 mm photo-detection area, comprising of 144 SiPMs with 36 readout channels, each one composed of four short-circuited SiPMs for an 8 mm × 8 mm active area. We have developed an Anger camera to characterize and qualify the array when coupled to a CsI:Tl scintillator (8 mm thick). We have measured an intrinsic spatial resolution better than 1.35 mm and an energy resolution below 14% using a 57Co source, when the tile is cooled down to -17°C to reduce the impact of the dark count rate on the measurements.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116261489","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":"Timing optimization for digital PET detector module based on FPGA-only MVT digitizers","authors":"Chen Zeng, D. Xi, W. Liu, Xiongze Mei, Xiang Liu, Heejong Kim, P. Xiao, C. Kao, Q. Xie","doi":"10.1109/NSSMIC.2014.7430851","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430851","url":null,"abstract":"Nowadays, time-of-flight (TOF) PET detectors and systems are becoming increasingly common since scintillators, photodetectors and electronics has made significant progress. It has been well recognized that TOF PET imaging can increase the image signal-to-noise ratio (SNR) and yield other benefits; and the degree of these enhancements is higher as the timing resolution improves. Previously we have developed a digital PET detector module using 48-channel FPGA-only MVT digitizer board and measured a coincidence resolving time (CRT) of 684ps (FWHM) and an energy resolution of 15% @511KeV. In this work, we investigate to replace our currently used SiPM with SiPMs that exhibit better timing characteristics. Specifically, we consider SensL FB30035 and Excelitas C30742-33-50C. We set a pair of single channel LYSO/SiPM detectors, first connect their output to an oscilloscope for both of SiPMs under test and measure their performance in different bias voltage. The results indicate that the CRT obtained for the SensL FM30035, SensL FB30035 and Excelitas C30742-33-50C-X are, respectively, 464ps, 310ps and 247ps FWHM. Based on these data sampled by oscilloscope, we also simulate the MVT sampling process and evaluate two common pulse model's suitability for both of SiPMs. Then we reconnect the signal from these SiPMs to our upgraded 72-channel MVT digitizer board. Timing resolution of 357ps and 278ps are achieved respectively by FB30035 and C30742.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115269368","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":"Electronic readout system for retina-based cosmic-ray telescope","authors":"A. Abba, F. Caponio, A. Geraci, N. Lusardi, N. Neri","doi":"10.1109/NSSMIC.2014.7431135","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7431135","url":null,"abstract":"We have designed a multichannel readout board to replace the old A-RX board of the LHCb TELL1, which is able to readout and process up to 8 BEETLE chips. We doubled the number of channels and the sampling speed of the old A-RX replacing the ADC with new serial converters and we added a powerful Kintex-7 FPGA to pre-process the data. Each board is able to readout 1024 channels simultaneously at the rate of 1.25 MHz.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124933656","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":"The sROD module for the ATLAS Tile Calorimeter upgrade demonstrator","authors":"F. Carrió, V. Castillo, A. Ferrer, L. Fiorini, Y. Hernandez, E. Higón, B. Mellado, P. Moreno, R. Reed, C. Solans, A. Valero, J. Valls","doi":"10.1109/NSSMIC.2014.7431253","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7431253","url":null,"abstract":"This work presents the first prototype of the super Read-Out Driver (sROD) demonstrator board for the Tile Calorimeter Demonstrator project. This project aims to test the new readout electronics architecture for the Phase II Upgrade of the ATLAS Tile Calorimeter, replacing the front-end electronics of one complete drawer with the new electronics during the shutdown at the end of 2015, in order to evaluate its performance. The sROD demonstrator board will receive and process data from a complete module sending it to the present RODs to keep compatibility with the current system. Moreover the sROD demonstrator board will transmit Timing, Trigger and Control information (TTC) and Detector Control System (DCS) commands to the front-end electronics.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125172908","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":"Simulation study of a pinhole SPECT system with a triple head gamma camera","authors":"Y. Ichimura, K. Ogawa","doi":"10.1109/NSSMIC.2014.7430822","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430822","url":null,"abstract":"The purpose of our research is to develop a new pinhole SPECT system using a triple head gamma camera system. The proposed data acquisition geometry used multi-pinhole collimators attached to each gamma camera. Acquired data were reconstructed with the OS-EM method. We evaluated the feasibility of the system with simulations. In the simulations, we evaluated three types of the pinhole collimators with the numbers of pinholes; 5, 8 and 11. And we used a brain phantom and myocardial phantom. Attenuation correction was conducted with the x-ray CT image of the corresponding slice. The results of the simulations confirmed the feasibility of our proposed multi-pinhole SPECT system with more than eight pinholes for each detector.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125322960","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":"Detector response modeling with asymmetric 2D Gaussian functions for GPU-based image reconstruction of the whole-body dual-ring OpenPET","authors":"H. Tashima, E. Yoshida, Tetsuya Shinaji, T. Yamaya","doi":"10.1109/NSSMIC.2014.7430806","DOIUrl":"https://doi.org/10.1109/NSSMIC.2014.7430806","url":null,"abstract":"We are developing the OpenPET which can provide an open space to make the patient observable and accessible during PET measurements. One of the key technologies for realizing the OpenPET geometry is the depth of interaction (DOI) detectors because the geometry has many oblique lines of response (LORs). Even if the DOI detectors reduce the blurring effect of the thick crystals, it is important to model the detector response function (DRF) in the reconstruction algorithm to achieve high spatial resolution images. In this study, therefore, we developed a new DRF model based on asymmetric 2D Gaussian functions perpendicular to the LOR for on-the-fly DRF calculation by GPUs during image reconstruction. In the proposed model, we virtually separated the detector crystal into two parts: head and tail. The head part has the shape of a cube. We set the center position of the asymmetric 2D Gaussian function at the center of the head part. The parameters of the asymmetric 2D Gaussian functions were calculated according to the size of the head part and tail part components perpendicular to the LOR. The proposed model was implemented on GPUs using the CUDA framework. We compared the proposed model with a simple Gaussian model and a crystal subsampling model which is an analytical model. We found DRFs in the proposed method provided a similar shape to that in the analytical model. In addition, the proposed model could include the blurring effect. The analytical model could represent only the effect of crystal shape, while the simple Gaussian model could represent only the blurring effect. Finally, the proposed method was applied for a prototype whole-body dual-ring OpenPET. As a result, the proposed method could improve the spatial resolution especially in the gap region of the OpenPET.","PeriodicalId":144711,"journal":{"name":"2014 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122843000","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}