1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference最新文献

{"title":"Quantitative Volume Analysis Of Coronary Vessel Systems By 3-D Reconstruction From Biplane Angiograms","authors":"A. Wahle, E. Wellnhofer, I. Mugaragu, H. U. Sauer, H. Oswald, E. Fleck","doi":"10.1109/NSSMIC.1993.701838","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701838","url":null,"abstract":"Quantitative evaluations on coronary vessel systems are of increasing importance in cardio-vascular diagnosis, therapy planning and surgical verification. Local evaluations, like stenosis analysis, are already available with sufficient accuracy. On the other hand, global evaluations on vessel segments or vessel subsystems are not yet common. Especially for the &agnosis of diffuse coronary artery diseases, we combined a 3-D reconstruction system operating on biplane angiogram with a length/volume calculation. The 3-D reconstruction results in a 3-D model of the coronary vessel system, consisting of the vessel skeleton and a discrete number of contours. To obtain a most accurate model, we focussed on exact geometry determination. Several algorithms for calculating missing geometric parameters and correcting remaining geometry errors were implemented and verified. The length/volume evaluation can be performed either on single vessel segments, on a set of segments, or on sub-trees. A volume model based on generalized elliptical conic sections is created for the selected segments. Volumes and lengths (measured along the vessel course) of those elements are summed up. In this way, the morphological parameters of a vessel subsystem can be set in relation to the parameters of the supplying segment proximal to it. These relations allow objective assessments of diffuse coronary artery diseases. sional measures defined on sets of sub-trees was selected and tested clinically. IT. 3-D RECONSTRUCTION A . Imaging Geometry and Point Reconstruction Standard biplane angiographic equipment consists of two x-ray systems having a common coordinate system [l]. In conventional methods, a fixed rotational origin of both systems is assumed where the projection axes intersect, the isocenter. For volume measurements, we need a very high reconstruction accuracy, because linear reconstruction errors raise to the third power. The classic isocenvic model could not satisfy this requirement: there is neither a stable isocenter, nor is there an adequate way to determine the required distances manually [21. In our geometric model, we use a variable iso-axis instead of a fixed isocenter. The distance of the projection axes creates a unique iso-axis orthogonal to both of them (fig. 2). The locations of x-ray sources and image intensifiers are determined in terms of distances to this iso-axis. The origin of the world coordinate system is defined as the weighted middle of the projection axes distance on the iso-axis. The angulation is obtained conventionally as a sequence of rotations, con-","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115717238","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":"Attenuation correction in 3D PET-comparison of the direct and the reconstruction-reprojection method","authors":"T. Beyer, D. Townsend, M. Defrise","doi":"10.1109/NSSMIC.1993.373523","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.373523","url":null,"abstract":"Two methods for attenuation correction in 3D positron emission tomography have been compared. The first method, which is referred to here as the direct method, estimates the attenuation correction factors from the ratio of the blank and transmission scan. The second method, referred to here as the reconstruction-reprojection method is based on the reconstruction and forward projection of a transmission image. Using computer simulation, it is shown that the reconstruction-reprojection method significantly increases the signal-to-noise ratio in the corrected 3D emission scan, but leads to only a limited improvement in the image. A similar image signal-to-noise ratio can be obtained using the direct method, if the transmission scan is first convolved with a 3-point smoothing window. The consequence of the loss of resolution caused by this smoothing is analysed using a simulated chest phantom.<<ETX>>","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114579541","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":"An Object-oriented Dataflow Software Development Tool For Medical Image Analysis","authors":"M. S. Atkins, B. Johnston, T. Zuk, T. Arden","doi":"10.1109/NSSMIC.1993.701848","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701848","url":null,"abstract":"Developers of new algorithms typically require an interactive environment in which the image data can be passed through various operators, some of which may involve feedback, synchronization, merging and conditional control strategies. This paper describes how the dataflow methodology of a pictorial object-oriented software development tool called WIT has greatly simplified the prototyping and testing of our new image registration and segmentation methods. WIT allows the user to draw a dataflow graph by linking operators in a CAD-like manner. We describe the main features of WIT, and show dataflow graphs for two medical image analysis algorithms; the 3D registration of PET scans into a common coordinate space, and tissue segmentation in MRI images where we are looking at quantitation of tumour volumes.","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124454200","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 Custom CMOS Integrated Circuit For PET Tomograph Front-end Applications","authors":"D. Binkley, M. Paulus, M. Casey, R. Nutt, W. Loeffler, J. Clif, J. M. Rochelle","doi":"10.1109/NSSMIC.1993.701771","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701771","url":null,"abstract":"A custom CMOS integrated circuit has been designed, prototyped, and evaluated for PET tomograph front-end applications. The integrated circuit reduces the size. cost, and power consumption of existing PET frontend circuits by Over a factor of two. The integrated circuit, fabricated in a standard digital, 2 p, double-metal, double-poly, n-well CMOS process, has a die size of 6.6mmx6.4mm and power consumption of under 600 mW. The PET front-end CMOS integrated circuit processes energy, position, and timing information from a BGO block detector containing four photomultiplier tubes. Photomultiplier preamplifiers and variable gain amplifiers are co~ected to summing circuits and gated integrators to provide energy and position (x and y) signals. A constantfraction discriminator, requiring no external delay line, provides a timing output derived from the sum of the four photomultiplier signals. Eight 7- and 8-bit digital-to-analog converters. connected to a readwrite serial data interface, provide gain-control and threshold levels. The measured position, energy, and timing performance (3.05ns FWHM) of the integrated circuit is comparable to existing discrete PET frontend circuits.","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123664240","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":"Brain image registration based on cortical contour mapping","authors":"C. Davatzikos, Jerry L Prince, R. Bryan","doi":"10.1109/NSSMIC.1993.373607","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.373607","url":null,"abstract":"The authors address the problem of brain image registration, and they present a new, nonlinear registration technique. In the first step of the authors' technique they obtain a point-to-point mapping between the outer cortical contours of the brain images using an elastic string algorithm. In the second step the authors register the two images based on the point-to-point correspondence established in the first step. They propose a new, nonlinear registration transformation, which is based on a spatially variable scaling and relation that can describe highly nonlinear deformations. Finally, the authors test their algorithm on two different registration problems: they first consider the registration of a postmortem photograph of a baboon brain cross-section and then an MR image of approximately the same cross-section.<<ETX>>","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122833833","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":"Instrumentation And Control Upgrade Planning At Arkansas Nuclear One","authors":"J. Jehlen, K. Nichols, D. Wilkinson, E. Brown","doi":"10.1109/NSSMIC.1993.701795","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701795","url":null,"abstract":"fNTRODlJCTION EPRI has undertaken the Instrumentation and Control (I&C) Initiative to reduce operations and maintenance (O&M) costs through long term life cycle management planning and to promote the cost effective use of modern technology in nuclear power plant I&C upgrades. A key element in the Initiative is the Demonstration Plant Program. The Demonstration Plant Program was started in 1991 with the goal of establishing comprehensive, integrata I&C maintenance and upgrade planning programs in operating nuclear power plants. The intent of these programs is to develop cost effective solutions to I&C obsolescence problems, and to demonstrate the technology developed under EPRI research and development programs. Currently, EPRI has established demonstration programs at eight plants including:","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126263276","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 Proposal Of Accurate Scatter Correction Method Considering Energy Spectra Of Scattered Photons In Single Photon Emission CT","authors":"A. Chugo, K. Ogawa","doi":"10.1109/NSSMIC.1993.701863","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701863","url":null,"abstract":"","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130113152","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":"Energy Transfer Mechanism In Gd/sub 2/(SiO/sub 4/)O:Ce Scintillators","authors":"H. Suzuki, T. Tombrello, C. Melcher, J. Schweitzer","doi":"10.1109/NSSMIC.1993.701640","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701640","url":null,"abstract":"The scintillation decay of cerium-doped gadolinium oxyorthosilicate Gd/sub 2/(SiO/sub 4/)O:Ce is lengthened by the energy transfer from Gd to Ce. To investigate the role of the Gd in the scintillation processes, the Gd was partially replaced by optically inactive rare earth elements, Y and Lu, and the effective transfer rates from Gd to Ce were measured as a function of Gd and Ce concentrations using UV- and gamma-ray excitations. The data clearly indicate the dilution of the Gd by the Y and the Lu further lengthens the migration time through the Gd in the energy transfer process from Gd to Ce. >","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"2197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130131926","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":"3D segmentation of Ct images on a massively parallel computer","authors":"S. Wegner, H. Oswald, E. Fleck, R. Felix","doi":"10.1109/NSSMIC.1993.702011","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.702011","url":null,"abstract":"For 3D scenes a 3D segmentation technique on a massively parallel computer is described and tested on CT image sequences. The approach is based on a volume growing technique driven by statistical features and a model depending on characteristic object parameters. The volumes of interest are specified interactively and used as seed volumes for the growing algorithm. An estimation technique is employed to calculate several statistical properties of these seed volumes. The required homogeneity criterion for each volume is then obtained in regard to the estimated statistics and the model of the object. These segmentation results are handled by a 3D morphological operator. Due to practical considerations the approach has been implemented on a massively parallel SIMD (single instruction multiple data) machine, the MasPar Mp1102.","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122032003","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":"Distance-dependent restoration filtering of dual photopeak window scatter compensated SPECT images","authors":"S. Glick, D. de Vries, Matt A. King","doi":"10.1109/NSSMIC.1993.373522","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.373522","url":null,"abstract":"A non-iterative SPECT reconstruction method is presented which consists of pre-processing the projection data for compensation of scatter, attenuation and the detector response prior to ramp filtered backprojection. Scatter is compensated for using the dual-photopeak window (DPW) method, attenuation is compensated for using Bellini's method, and compensation for the non-stationary detector response and noise suppression is performed with a frequency distance principle (FDP) Wiener filter. This approach was compared to a number of different processing methods using a Monte Carlo simulation study of an anthropomorphic digitized phantom of the liver and spleen. Compared to Butterworth smoothing, the DPW/FDP Wiener filtering method can provide a substantial increase in contrast with a noise increase ranging from minimal to moderate depending on the cut-off frequency of the Butterworth filter.<<ETX>>","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"166 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122408072","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}