IEEE Nuclear Science Symposuim & Medical Imaging Conference最新文献_第7页

Segmentation of rat spinal cord in PET using spatiotemporal information 基于时空信息的PET大鼠脊髓分割

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5874483

E. K. Fung, D. Weinzimmer, S. Strittmatter, Yiyun Huang, R. Carson

引用次数: 0

Elastic cross-sections for low energy collision of Ar+ with Ne and Monte Carlo simulation of the transport of Ar+ ions in gaseous Ar/Ne mixtures Ar+与Ne低能碰撞的弹性截面和Ar+离子在气体Ar/Ne混合物中输运的Monte Carlo模拟

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5874019

J. Barata, C. Conde

{"title":"Elastic cross-sections for low energy collision of Ar+ with Ne and Monte Carlo simulation of the transport of Ar+ ions in gaseous Ar/Ne mixtures","authors":"J. Barata, C. Conde","doi":"10.1109/NSSMIC.2010.5874019","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874019","url":null,"abstract":"The drift velocities and the longitudinal and transverse diffusion coefficients for Ar+ ions in gaseous Ar/Ne mixtures, at atmospheric pressures, for Ar concentrations between 1 and 20%, and reduced electric field strengths, E/N, from 1 to 100 Td, corresponding to E/p, from about 0.329 to 32.9 V cm−1 Torr−1 at 293 K, are calculated by Monte Carlo simulation. The Monte Carlo simulations use a set of integral and differential elastic collision cross-sections for Ar+ ions with neutral Ar and Ne atoms. Differential and integral elastic collision cross-sections for Ar+ ions with neutral Ne atoms are calculated, and reported for center-of-mass energies between 1 meV and 10 eV, using a modified Tang and Toennies ion-atom interaction potential model to describe ab initio spectroscopic data for the ArNe+ molecular ion and the long-range interaction potentials. The phase shifts were calculated with the JWKB approximation. The cross-sections for the collision of Ar+ ions with Ar atoms used were the ones calculated before by the authors.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"27 1","pages":"1476-1479"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78157546","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}

引用次数: 0

Mixture model for fast estimation of positron range 快速估计正电子距离的混合模型

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5874361

P. Olcott, Eric Gonzalez, A. Vandenbroucke, C. Levin

引用次数: 1

A study of transit time variation in the PMT with a gain programmable voltage divider for a TOF PET 带增益可编程分压器的TOF PET PMT中传输时间变化的研究

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5874162

Chao Wang, Hongdi Li, S. An, Yuxuan Zhang, H. Baghaei, R. Ramirez, Shitao Liu, W. Wong

{"title":"A study of transit time variation in the PMT with a gain programmable voltage divider for a TOF PET","authors":"Chao Wang, Hongdi Li, S. An, Yuxuan Zhang, H. Baghaei, R. Ramirez, Shitao Liu, W. Wong","doi":"10.1109/NSSMIC.2010.5874162","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874162","url":null,"abstract":"In the front-end circuit of a Positron Emission Tomography (PET) camera, adjusting the photomultipliers (PMT) gain by changing the voltage distribution in dynodes instead of changing the total high voltage is more convenient to realize, and this method is better in signal-to-noise-ratio (SNR) than using a variable-gain-amplifier (VGA) in the signal path which may induce extra noise. In this study, we revised the previous voltage divider design to achieve wider gain adjustable range which relaxes the PMT gain-spread requirement to reduce the PMT cost. An accurate test bench was used to measure the PMT transit time variation as a function of the relative gain. From the test result, within the adjustable gain range, the PMT transit time variation can be as large as several hundreds of picoseconds; and this is non-ignorable in the Time-of-Flight (TOF) applications. Hence, a time correction is required. A look-up-table (LUT) from the transit time variation vs. PMT relative gain curve is used to correct this transit time variation with the gain adjustment simultaneously without performing the time-consuming entire system timing recalibration.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"22 1","pages":"2155-2157"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78963126","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}

引用次数: 0

3D cone-beam rebinning and reconstruction for animal PET transmission tomography 动物PET透射断层扫描三维锥束重建

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5874323

Junjun Deng, S. Siegel, Mu Chen

{"title":"3D cone-beam rebinning and reconstruction for animal PET transmission tomography","authors":"Junjun Deng, S. Siegel, Mu Chen","doi":"10.1109/NSSMIC.2010.5874323","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874323","url":null,"abstract":"In PET scanners, one or multiple collimated point sources are used to acquire transmission measurements to generate attenuation maps for emission tomography [1]. The transmission acquisition is, intrinsically, 3D cone beam geometry. The acquired list-mode data are transformed into sinograms in the histogram process. Thereafter, transmission images are reconstructed from the sinograms, which are then re-projected to generate an attenuation map. Conventionally, a 2D rebinning method is used to transform the list-mode data into 2D parallel beam sinograms [2], and, accordingly, 2D reconstruction algorithms are employed to generate transmission images. Due to the inaccuracy of the 2D rebinning method, only limited oblique Lines of Response (LOR) can be used, causing limited axial coverage. If more oblique LORs were to be accepted in the rebinning process, artifacts would be introduced in the transmission images that may result in inaccurate attenuation correction factors. To address this issue, a 3D cone-beam rebinning process is proposed to faithfully transform the list-mode data, and the associated reconstruction algorithms for cone-beam geometry have been adopted to generate the transmission images. The experimental results showed the new method produced better images, especially in the axial direction.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"94 1","pages":"2885-2888"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87686070","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}

引用次数: 0

Integration of radiation transport models in an interactive video game to train law enforcement and first responders on preventative RAD/NUC detection (PRND) methods 在互动视频游戏中集成辐射传输模型，以培训执法人员和急救人员预防性RAD/NUC检测(PRND)方法

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5873823

J. Winso, J. Rolando, W. H. Knight, E. S. Ackermann, V. Wijekumar, H. Yu

引用次数: 1

Maintaining low radiation damage of lead tungstate scintillation crystals operating in high dose rate radiation environment 在高剂量率辐射环境下维持钨酸铅闪烁晶体的低辐射损伤

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5873917

A. Borisevitch, V. Dormenev, A. Fedorov, M. Korjik, T. Kuske, V. Mechinsky, O. Missevitch, R. Novotny, R. Rusack, A. Singovski

{"title":"Maintaining low radiation damage of lead tungstate scintillation crystals operating in high dose rate radiation environment","authors":"A. Borisevitch, V. Dormenev, A. Fedorov, M. Korjik, T. Kuske, V. Mechinsky, O. Missevitch, R. Novotny, R. Rusack, A. Singovski","doi":"10.1109/NSSMIC.2010.5873917","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5873917","url":null,"abstract":"Scintillation crystals of the lead tungstate family — PWO, PWO-II — became widely used in electromagnetic calorimeters in high energy physics experiments at high luminosity accelerator facilities. During the operation of electromagnetic calorimeters a damage of the optical transmission of the crystals occurs due to creation of color centers. In addition to the recharge of a priori in the crystals existing defects by γ-radiation additional damage of the crystal matrix occurs due to hadrons. Therefore, radiation induced optical absorption can limit the energy resolution of the calorimeter. We have minimized radiation damage effects by technological efforts to obtain perfect crystals with a minimal concentration of the defects creating metastable color centers as well as the recoven' of color centers by stimulation with infrared light. In this paper we discuss the method of stimulated recovery of radiation induced absorption which can be even applied in situ. The mechanisms of the damage under γ- and hadronirradiation are described.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"os-55 1","pages":"1010-1013"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87095793","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}

引用次数: 3

Development of pulsed X-ray tube equipped streak camera system to study scintillation phenomenon 用于研究闪烁现象的脉冲x射线管条纹相机系统的研制

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5873742

T. Yanagida, Y. Fujimoto, Y. Furuya, Y. Yokota, N. Kawaguchi, K. Kamada, J. Pejchal, Varely Chani, K. Fukuda, D. Totsuka, K. Uchiyama, Kuniyoshi Mori, Ken Kitano, M. Nikl, A. Yoshikawa

引用次数: 0

Fingertip beta imager based on the SiPM technology 基于SiPM技术的指尖beta成像仪

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5874257

A. Stolin, S. Majewski, R. Raylman, H. W. Hazard

{"title":"Fingertip beta imager based on the SiPM technology","authors":"A. Stolin, S. Majewski, R. Raylman, H. W. Hazard","doi":"10.1109/NSSMIC.2010.5874257","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874257","url":null,"abstract":"We have implemented the low-profile SENSL 16ch SPMArray2 module in a small prototype of a beta/positron imager. The SiPM sensor has a 0.5–1mm thick plastic scintillator optically coupled via thin (1–2mm) glass window for better light spread between the sixteen 3mm SiPM pads to allow center of gravity position calculations of the scintillation light flashes. In the initial studies, aluminized Mylar foil and Teflon tape were used for a top surface reflector, and black Tedlar foil for a light-tight mechanical barrier. Sensitivity of 3–5 counts/sec per nanoCi was measured with one layer of 50 micron Teflon and 50 micron Tedlar each. For two Tedlar layers the sensitivity was lower by about 10 percent with the applied broad energy window. Intrinsic spatial resolution was estimated at approximately 2.5mm, with the un-collimated positron beam distribution limiting the measurement. The position information can be used as a finer indication when the hot spots are located within the ∼10mm×10mm useful FOV of the device. According to the initial plans, the imager will be evaluated as a tool assisting with checking the cancer margin adequacy in breast cancer excision (lumpectomy). Before surgery, the patient will obtain systemic injection of positron biomarker, such as F18-FDG, the same that was used to detect the cancer in the PET procedure. Attached to the surgeons fingertip, the imager will be used to scan the surface of the post-extraction cavity for residual positron activity as an indication of non-sufficient cancer margins, to allow for immediate in-situ correction. The imager is planned as another instrument in the set of complementary imaging and non-imaging tools to assist with breast cancer surgeries, not to replace other tools.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"46 1","pages":"2595-2597"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88315070","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}

引用次数: 2

Imaging performance of two multiple-pinhole small-animal SPECT systems: Multiplexed vs. non-multiplexed data acquisition 两种多针孔小动物SPECT系统的成像性能:多路与非多路数据采集

IEEE Nuclear Science Symposuim & Medical Imaging Conference Pub Date : 2010-10-01 DOI: 10.1109/NSSMIC.2010.5874400

Mi-Ae Park, E. Lunsford, R. Zimmerman, S. Southekal, J. Frangioni, S. Moore

{"title":"Imaging performance of two multiple-pinhole small-animal SPECT systems: Multiplexed vs. non-multiplexed data acquisition","authors":"Mi-Ae Park, E. Lunsford, R. Zimmerman, S. Southekal, J. Frangioni, S. Moore","doi":"10.1109/NSSMIC.2010.5874400","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874400","url":null,"abstract":"Increasing the number of pinholes in small-animal SPECT significantly improves its count sensitivity. When the detector(s) are small, however, overlapping of projections (multiplexing) from different pinholes is unavoidable and can amplify noise in reconstructed images. We have evaluated the performance of two multi-pinhole systems, one with and one without multiplexing, for a prototypical tumor-imaging task. We prepared seven beads (∼1.8-mm diameter) to mimic tumors labeled with Tc-99m. A uniform gelatin phantom was used to simulate normal background tissue. The tumor-to-normal tissue ratio was ∼6:1, and each bead contained ∼1 μCi. The first scanner, equipped with two 0.8-mm pinholes on each of three heads (HMS-0.8), acquired only non-overlapping projections. We also scanned the phantom using 1.6mm pinholes (HMS-1.6) The second scanner had 9 pinholes on each of four heads, and allowed multiplexing. To compensate for decay, the phantom was scanned for 50 min on HMS-0.8, 58 min on HMS-1.6, 82 min on NanoSPECT/CT with 1.4 mm pinholes (Nano-1.4), and 102 min with 1.0 mm pinholes (Nano-1.0). A total of 30 (24) angular projections were acquired with HMS (Nano); these were reconstructed using 10 OSEM subsets for HMS, and 4 subsets for Nano. The mean voxel value in each sphere, and the mean and standard deviation in a large VOI in the background, were used to compute the signal-to-noise ratio (SNR) and contrast of each bead. The relative noise in the background was also calculated. The systems with and without multiplexing yielded similar image quality and average bead SNR, especially for HMS-0.8 and Nano-1.0. Both systems yielded very similar SNR values, despite the fact that the multiplexed system acquired data using 36 pinholes, while the non-multiplexed system had only 6 pinholes. The multiplexed acquisition did not seem to adversely affect the image contrast of the spherical tumors.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"4 1","pages":"3225-3227"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88356444","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}

引用次数: 0