2002 IEEE Nuclear Science Symposium Conference Record最新文献_第5页

Development of transmission Si(Li) detectors 透射式Si(Li)探测器的研制

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239332

D. Protic, T. Krings

{"title":"Development of transmission Si(Li) detectors","authors":"D. Protic, T. Krings","doi":"10.1109/NSSMIC.2002.1239332","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239332","url":null,"abstract":"During the development of double-sided microstructured Si(Li) detectors thin Li-doped contacts with effective thicknesses below 10 /spl mu/m could be created. The effective thickness was determined by evaluating the measured energy loss of /spl alpha/-particles entering the detector through the Li-doped contact. Extensive examinations have been performed to rind the correlation between the effective thicknesses determined with the help of of /spl alpha/-particles and the thicknesses based on the measured distribution of the Li-ions; in the Li-diffused layers. Pronounced discrepancies were found in the relation between the effective thicknesses and the thicknesses of the removed layer during the thinning process. In any case, the effective thickness was considerably smaller than the thickness concluded from the distribution of the Li-ions. The dependence of the effective thickness on the bias voltage and the temperature was studied. A possible explanation of the relatively small effective thicknesses based on the internal electric field inside the Li-doped layer caused by the concentration gradient is presented. The technique to create Li-doped layers with an effective thickness smaller than 5 /spl mu/m is described. In this way, the transmission Si(Li) detectors with effective dead layers being smaller than 0.1% of their thickness can be realized (patent is riled).","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126520892","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: 5

Novel neutron detector for high rate imaging applications 用于高速率成像应用的新型中子探测器

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239339

J. Lacy, A. Athanasiades, N. N. Shehad, R. Austin, C.S. Martin

{"title":"Novel neutron detector for high rate imaging applications","authors":"J. Lacy, A. Athanasiades, N. N. Shehad, R. Austin, C.S. Martin","doi":"10.1109/NSSMIC.2002.1239339","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239339","url":null,"abstract":"Next generation neutron science facilities, such as the Spallation Neutron Source, require improved thermal neutron detectors, with high counting rate capability, high spatial resolution, low cost per unit area, and adaptability to unique geometries. We propose a neutron detector technology, based on arrays of boron-lined plastic straws, that satisfies the above requirements. The elemental component of this detector is a B/sub 4/C-lined mylar straw, 4 mm in diameter and 1 m long, and operated as a proportional counter with an Ar/ethane gas mixture. Thermal neutrons captured in /sup 10/B are converted into secondary particles, which ionize the gas contained within the straw. Using a deep stack of such straws, with 20-25 layers, neutron detection efficiencies up to 80% can be achieved in the 1-10 /spl Aring/ neutron wavelength range. In such a highly segmented array, exceedingly high count rates can be achieved, on the order of 200/spl times/10/sup 6/ cps/m/sup 2/. Gamma ray discrimination was on the order of 10/sup 6/ for an energy threshold of 50 keV; position resolution of a 1-m long detector was measured to be 5.5 mm FWHM, and a highly linear readout was achieved using resistive charge division.","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128151958","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: 18

3D motion estimation with image reconstruction for gated cardiac ECT 门控心脏电痉挛图像重建的三维运动估计

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239687

Z. Cao, D. Gilland, B. Mair, R. Jaszczak

引用次数: 4

Imaging characterization of an experimental apparatus for dual energy angiography 双能血管造影术实验装置的成像特性

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239678

G. Baldazzi, B. Bernardi, D. Bollini, M. Gambaccini, M. Gombia, P. Rossi, A. Sarnelli, A. Taibi, A. Tuffanelli, G. Pancaldi, M. Zuffa

{"title":"Imaging characterization of an experimental apparatus for dual energy angiography","authors":"G. Baldazzi, B. Bernardi, D. Bollini, M. Gambaccini, M. Gombia, P. Rossi, A. Sarnelli, A. Taibi, A. Tuffanelli, G. Pancaldi, M. Zuffa","doi":"10.1109/NSSMIC.2002.1239678","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239678","url":null,"abstract":"An angiographic practice an iodate contrast medium is injected in patient vessels with catheters. The absorption of X-rays rises immediately above the Iodine K-edge energy (33.17 keV), permitting to distinguish human soft tissues characterized by similar absorption's coefficients. Conventional image subtraction technique uses two images, acquired before and after the injection of the contrast medium, respectively. The vessels' morphology results from the difference of images so obtained. A different approach is presented: two quasimonochromatic peaks, having mean energies lower and higher than the Iodine K-edge, are produced with a pyrolytic graphite crystal monochromator and split in two thin parallel beams, respectively. These two beams impinge on phantoms simulating patient vessels and are detected with solid-state array detectors. The image results as the difference between the intensities of the two beams emerging from patient tissues and Iodine. In this work, we show results and first image of a phantom, characterized by calibrated vessels inside, obtained with an experimental apparatus to perform a double energy scanning in a 120 mm /spl times/ 120 mm field of view.","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121584820","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: 6

A new framework of quantifying differences between images by matching gradient fields and its application to image blending 基于梯度场匹配的图像差异量化框架及其在图像混合中的应用

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239511

W. Liao, Chin-Lung Yu, Marvin Bergsneider, L. Vese, Sung-Cheng Huang

{"title":"A new framework of quantifying differences between images by matching gradient fields and its application to image blending","authors":"W. Liao, Chin-Lung Yu, Marvin Bergsneider, L. Vese, Sung-Cheng Huang","doi":"10.1109/NSSMIC.2002.1239511","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239511","url":null,"abstract":"This paper presents a new method for quantifying the differences between images. The proposed model is based on matching the gradient fields of two images. We first define new image spaces in which images are considered equivalent under a similarity group actions and the difference between two image classes is then defined by employing the Cauchy-Schwarz inequality to the gradient fields. The advantage of our approach is that images are identified by their relative contrasts and thus is scale free. Using this approach, we are able to achieve image blending in a novel way. By modifying the group actions, we extend our basic model to more general equivalence classes. The variational problems and the corresponding Euler-Lagrange equations associated to these models are proposed and the gradient descent time dependent partial differential equations are derived. Fast and efficient solvers employing the Additive Operator Splitting scheme are also presented. We tested our models on simulation images as well as real brain MRI and PET images from normal control subjects.","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"58 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121714605","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: 4

PET and SPECT performance of the Siemens HD3 e.cam/sup duet//spl reg/ : a 1" Na(I) hybrid camera PET和SPECT性能的西门子HD3 e.cam/sup //spl reg/: 1“Na(I)混合相机

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239606

V. Sossi, O. Morin, A. Celler, T.D. Rempel, A. Belzberg, C. Carhart

引用次数: 3

Improving large angle cone beam CT image reconstruction with practical supplementary information 用实用的补充信息改进大角度锥束CT图像重建

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239491

K. Tam, H. Bruder, K. Stierstorfer, T. Flohr, K. Sourbelle, A. Khamene

{"title":"Improving large angle cone beam CT image reconstruction with practical supplementary information","authors":"K. Tam, H. Bruder, K. Stierstorfer, T. Flohr, K. Sourbelle, A. Khamene","doi":"10.1109/NSSMIC.2002.1239491","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239491","url":null,"abstract":"Single circle cone beam scan is simple and fast to execute and image reconstruction with the Feldkamp algorithm is efficient, thus it is widely employed in a number of major medical imaging modalities. Cone beam scanners employing large area flat panel detectors with 256 rows or more are expected to appear on the market in the next few years. The large number of rows allows the collection of a large quantity of data in a very short time, and thus the new generation of scanners will be suited for scanning dynamic objects. Because of its speed single circle scan will be ideal for such scans. In 3D angio systems employing C arms the popular scan mode is circular arc, which is less complete compared to single circle scan. It is well known that a single circle scan path with Feldkamp reconstruction does not yield complete information to reconstruct the object. There are missing Radon data located along the rotation axis and its neighborhood In this paper we investigate the improvement to lite single circle scan reconstruction images with the use of supplemental), information. In particular we study a supplementary line scan and a supplementary circle scan. We also discuss the use of other sources of supplementary information, including topogram and a priori information.","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131346548","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

Impact of different realignment algorithms on the SPM analysis of [/sup 11/C]raclopride PET studies 不同调整算法对raclopride PET研究SPM分析的影响

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239509

M. Zamburlini, R. de la Fuente-Fernández, A. Stoessl, T. Ruth, V. Sossi

{"title":"Impact of different realignment algorithms on the SPM analysis of [/sup 11/C]raclopride PET studies","authors":"M. Zamburlini, R. de la Fuente-Fernández, A. Stoessl, T. Ruth, V. Sossi","doi":"10.1109/NSSMIC.2002.1239509","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239509","url":null,"abstract":"In this paper we address the issue of how the preprocessing steps of a typical neuroreceptor PET study may influence the outcome of an SPM analysis examining inter-condition differences. Two preprocessing steps and their possible interaction were investigated: 1) the realignment of dynamic images to correct for patient's motion and 2) the effect of the template in the normalization step required by SPM. Methods: The impact of different realignment algorithms was tested by performing the SPM analysis on a six patient - two conditions /sup 11/C-raclopride (RAC) study where the dynamic images of each subject were re-aligned with four algorithms. Once realigned, the images were normalized to the standard cerebral blood flow (CBF) template. available in SPM, and to a RAC template. The SPM pattern showing the inter-condition differences obtained in each case was compared with the expected one. The accuracy of the four alignment algorithms used was further tested using a set of motion-free RAC studies. Results/Conclusion: We found that 1) different realignment algorithms may create different inter-condition difference patterns, 2) such differences in the results may be due to a failure in accuracy of some realignment algorithms, and 3) the use of a template that closely matches the spatial distribution of the tracer under investigation can minimize these problems.","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134071228","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

Optimization of design for X-ray imaging gas polarimeter using computer simulation x射线成像气体偏振计的计算机模拟优化设计

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239293

T. Suzuki, S. Gunji, H. Sakurai, F. Tokanai

引用次数: 1

Triple GEM structure for medical imaging 用于医学成像的三重GEM结构

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239528

E. Tsyganov, A. Buzulutskov, P. Antich, J. Moore, R. Parkey, E. Richer, S. Seliounine, N. Slavine, T. Nguyen

引用次数: 2