IEEE Nuclear Science Symposium Conference Record, 2005最新文献

{"title":"Estimating 3D respiratory motion from orbiting views","authors":"R. Zeng, J. Fessler, J. Balter","doi":"10.1109/NSSMIC.2005.1596816","DOIUrl":"https://doi.org/10.1109/NSSMIC.2005.1596816","url":null,"abstract":"This paper describes a method for estimating 3D respiratory motion so as to characterize tumor motion. This method uses two sets of measurements. One is a reference thorax volume obtained from a conventional fast CT scanner under breath-hold condition. The other is a sequence of projection views of the same patient (acquired at treatment time) using a slowly rotating cone-beam system (1 minute per rotation) during free breathing. We named this method deformation from orbiting views (DOV). Breathing motion over the entire acquisition period is estimated by deforming the reference volume through time so that its projections best match the measured projection views. The nonrigid breathing motion is described by a B-spline based deformation model. The parameters of this model are estimated by minimizing a regularized squared error cost function, using a conjugate gradient descent algorithm. Performance of this approach was evaluated by simulation. Results showed good agreement between the estimated and synthesized motion, with a mean absolute error of 1.63 mm. Relatively larger errors tended to occur in uniform regions, which would not have significant effects on generating deformed volumes based on the estimated motion. The results indicate that it is feasible to estimate realistic nonrigid motion from a sequence of slowly rotating cone beam projection views.","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115689371","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":"Track clustering and vertexing algorithm for L1 trigger","authors":"G. Cancelo","doi":"10.1109/NSSMIC.2005.1596250","DOIUrl":"https://doi.org/10.1109/NSSMIC.2005.1596250","url":null,"abstract":"One of the keystones of the canceled BTeV experiment (proposed at Fermilab's Tevatron) was its sophisticated three-level trigger. The trigger was designed to reject 99.9% of light-quark background events and retain a large number of B decays. The BTeV pixel detector provided a 3-dimensional, high resolution tracking system to detect B signatures. The level 1 pixel detector trigger was proposed as a two stage process, a track-segment finder and a vertex finder which analyzed every accelerator crossing. In simulations the track-segment finder stage outputs an average of 200 track-segments per accelerator crossing (2.5 MHz). The vertexing stage finds vertices and associates track-segments with the vertices found. This paper proposes a novel adaptive pattern recognition model to find the number and the estimated location of vertices, and to cluster track-segments around those vertices. The track clustering and vertex finding is done in parallel. The pattern recognition model also generates the estimate of other important parameters such as the covariance matrix of the cluster vertices and the minimum distances from the tracks to the vertices needed to compute detached tracks.","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133041322","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":"Statistical reconstruction methods in PET: resolution limit, noise, edge artifacts and considerations for the design of better scanners","authors":"J. L. Herraiz, S. España, J. Udías, J. Vaquero, M. Desco","doi":"10.1109/NSSMIC.2005.1596690","DOIUrl":"https://doi.org/10.1109/NSSMIC.2005.1596690","url":null,"abstract":"Small animal positron emission tomography (PET) scanners are being increasingly used as a basic measurement tool in modern biomedical research. The new designs and technologies of these scanners and the modern reconstruction methods have allowed to reach high spatial resolution and sensitivity. Despite their successes, some important issues remain to be addressed in high resolution PET imaging. First, iterative reconstruction methods like maximum likelihood-expectation maximization (MLEM) are known to recover resolution, but also to create noisy images and edge artifacts if some kind of regularization is not imposed. Second, the limit of resolution achievable by iterative methods on high resolution scanners is not quantitatively understood. Third, the use of regularization methods like Sieves or maximum a posteriori (MAP) requires the determination of the optimal values of several adjustable parameter that may be object-dependent. In this work we review these problems in high resolution PET and establish that the origin of them is more related with the physical effects involved in the emission and detection of the radiation during the acquisition than with the kind of iterative reconstruction method chosen. These physical effects (positron range, non-collinearity, scatter inside the object and inside the detector materials) cause that the tube of response (TOR) that connects the voxels with a line of response (LOR) is rather thick. This implies that the higher frequencies of the patient organ structures are not recorded by the scanner and therefore cannot be recovered during the reconstruction. As iterations grow, ML-EM algorithms try to recover higher frequencies in the image. Once that a certain critic frequency is reached, this only maximizes high frequency noise. Using frequency response analyses techniques, we determine the maximum achievable resolution, before edge artifacts spoil the quality of the image, for a particular scanner as a function of the thickness of the TOR, and independently of the reconstruction method employed. With the same techniques, we can deduce well defined stopping criteria for reconstructions methods. Also, criteria for the highest number of subsets which should be used and how the design of the scanners can be optimized when statistical reconstruction methods are employed, is established.","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131198299","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":"Active nuclear material detection and imaging","authors":"D. R. Norman, J. Jones, K. J. Haskell, P. Vanier, L. Forman","doi":"10.1109/NSSMIC.2005.1596423","DOIUrl":"https://doi.org/10.1109/NSSMIC.2005.1596423","url":null,"abstract":"An experimental evaluation has been conducted to assess the operational performance of a coded-aperture, thermal neutron imaging system and its detection and imaging capability for shielded nuclear material in pulsed photonuclear environments. This evaluation used an imaging system developed by Brookhaven National Laboratory. The active photonuclear environment was produced by an operationally-flexible, Idaho National Laboratory (INL) pulsed electron accelerator. The neutron environments were monitored using INL photonuclear neutron detectors. Results include experimental images, operational imaging system assessments and recommendations that would enhance nuclear material detection and imaging performance.","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114011137","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 CMS object-oriented simulation","authors":"S. Abdoulline, N. Amapane, F. Ambroglini, P. Arce, S. Ashby, S. Banerjee, U. Berthon, T. Boccali, M. Case, C. Charlot, H. Cheung, T. Cox, N. Darmenov, A. De Roeck, X. Ding, S. Dutta, D. Elvira, F. Ferro, A. Giammanco, P. Govoni, O. Gutsche, X. Huang, V. Innocente, C. Jones, A. Kharchilava, P. Katsas, J. Kowalkowski, K. Lassila-Perini, S. Magni, P. Meridiani, F. Moortgat, A. Nikitenko, I. Osborne, M. Paterno, M. Pioppi, S. Piperov, N. Ratnokiva, A. Rizzi, E. Sexton-Kennedy, E. Shabalina, L. Silvestris, M. Spiropulu, M. Stavrianakou, W. Tanenbaum, J. Weng, T. Wildish, R. Wilkinson, S. Wynhoff, A. Yagil, J. Yarba, M. Zanetti, A. Zhokin","doi":"10.1109/NSSMIC.2005.1596421","DOIUrl":"https://doi.org/10.1109/NSSMIC.2005.1596421","url":null,"abstract":"The CMS object oriented Geant4-based program is used to simulate the complete central CMS detector (over 1 million geometrical volumes) and the forward systems such as the Totem telescopes, Castor calorimeter, zero degree calorimeter, Roman pots, and the luminosity monitor. The simulation utilizes the full set of electromagnetic and hadronic physics processes provided by Geant4 and detailed particle tracking in the 4 tesla magnetic field. Electromagnetic shower parameterization can be used instead of full tracking of high-energy electrons and positrons, allowing significant gains in speed without detrimental precision losses. The simulation physics has been validated by comparisons with test beam data and previous simulation results. The system has been in production for almost two years and has delivered over 100 million events for various LHC physics channels. Productions are run on the US and EU grids at a rate of 3-5 million events per month. At the same time, the simulation has evolved to fulfill emerging requirements for new physics simulations, including very large heavy ion events and a variety of SUSY scenarios. The software has also undergone major technical upgrades. The framework and core services have been ported to the new CMS offline software architecture and event data model. In parallel, the program is subjected to ever more stringent quality assurance procedures, including a recently commissioned automated physics validation suite","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122682521","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 16-channel silicon strips readout chip in 180 nm CMOS technology","authors":"M. Dhellot, J. Genat, H. Lebbolo, T. Pham, A. Savoy-Navarro","doi":"10.1109/NSSMIC.2005.1596586","DOIUrl":"https://doi.org/10.1109/NSSMIC.2005.1596586","url":null,"abstract":"A highly integrated readout scheme for silicon trackers making use of deep sub-micron CMOS electronics (DSM) is presented. In the context of the International Linear Collider (ILC) trackers developments, a 16-channel readout chip for silicon strips detector has been designed in 180 nm CMOS technology, each channel comprising a low noise amplifier, a pulse shaper, a sample and hold and a comparator. Results are presented.","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133593504","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":"LCFI charge transfer inefficiency studies for CCD vertex detectors","authors":"A. Sopczak","doi":"10.1142/9789812773678_0140","DOIUrl":"https://doi.org/10.1142/9789812773678_0140","url":null,"abstract":"The Linear Collider Flavour Identification (LCFI) collaboration studies CCD detectors for quark flavour identification in the framework of a future linear e+e- collider. The flavour identification is based on precision reconstruction of charged tracks very close to the interaction point. Therefore, this detector will be exposed to a high level of radiation and thus an important aspect of the vertex detector development are radiation hardness studies. Results of detailed simulations of the charged transport properties of a CCD prototype chip are reported and compared with initial measurements. The simulation program allows to study the effect of radiation damage after the exposure of the detector to a realistic radiation dose, which is expected in the environment of detector operation at a future LC","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131289002","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 ALICE data-acquisition system","authors":"J. Nelson, O. Baillie, E. Denes, A. Holba, G. Rubin, L. Szedrei, T. Kiss, Z. Meggyesi, W. Bozzoli, R. Divià, G. Harangozó, R. Mclaren, H. G. Ritter, E. V. D. Bij, P. Vyvre, A. Vascotto, R. Brockmann, B. Kolb, M. Purschke, M. Beldishevski, M. Bellato, G. Maron, Bjarne Kvamme, B. Skaali, Bin Wu, H. Beker","doi":"10.1142/9789814447188_0072","DOIUrl":"https://doi.org/10.1142/9789814447188_0072","url":null,"abstract":"ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma in nucleus-nucleus collisions at the CERN Large Hadron Collider (LHC). A large bandwidth and flexible DAQ is required to collect sufficient statistics in the short running time available per year for heavy ion and to accommodate very different requirements originated from the large set of detectors and the different beams used","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120900351","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":"System calibration and statistical image reconstruction for sub-mm stationary pinhole SPECT","authors":"F. van der Have, B. Vastenhouw, M. Rentmeester, F. Beekman","doi":"10.1109/NSSMIC.2005.1596883","DOIUrl":"https://doi.org/10.1109/NSSMIC.2005.1596883","url":null,"abstract":"Iterative SPECT reconstruction requires position-dependent point spread functions (PSFs) specifying the response of the detectors to a point source at every position in the instrument. To obtain accurately reconstructed images, the PSFs should incorporate all important effects of photon transport and imaging geometry. The PSFs can be measured directly, but measuring in each voxel of the object space can be impractical for sub-mm-resolution instruments. This study describes a method for generating complete PSF lookup tables from a limited number of point source measurements for a stationary small-animal SPECT system with 75 pinholes (U-SPECT-I, J. Nucl. Med., 2005, pp. 1194-1200). The method is based on modeling the shape of the PSFs, measured at a limited number of positions. Subsequently the model parameters are generalized to estimate and shape PSFs at missing positions. The method enables us to obtain 0.45 mm reconstructed resolution with 0.6 mm pinholes and 0.35 mm resolution with 0.3 mm pinholes with a SPECT system which has 3.2 mm intrinsic detector resolution","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115392705","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":"Gamma scanning evaluation for random packed columns","authors":"V. Pas, F. E. Costa, P. Rela, W. Calvo, G. LeRoux, M. M. Hamada","doi":"10.1109/NSSMIC.2005.1596306","DOIUrl":"https://doi.org/10.1109/NSSMIC.2005.1596306","url":null,"abstract":"In the present study, the liquid (water) holdup distribution was measured in a packed column (7.62 cm diameter) filled with 0.9 cm glass Rashig rings using noninvasive gamma ray technique. Three different radioactive sources: 11.1 MBq 60Co (1133 keV), 74 GBq 131I (380 keV), and 740 GBq 99mTc (140 keV) with a CsI(Tl) detector coupled to a photodiode were used to scan the column. The primary objective is to detect spatial patterns and statistical information on liquid distribution in packed distillation columns. Vertical scans, at different positions of the packed bed, were made for different liquid and gas flow rates. A mathematical relation based in the transmission radioactive by materials was used to calculate the spatial variation of liquid hold-up along the column. It was found that the liquid holdup distribution was not uniform and that the liquid distributor design had a significant effect on the holdup distribution. The system proved to be very useful in monitoring the condition of the process of packed column showing liquid distributions. The better results were found using a 99mTc source. Flooded sections in the column can easily be identified using this technique","PeriodicalId":105619,"journal":{"name":"IEEE Nuclear Science Symposium Conference Record, 2005","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115666843","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}