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Sample records for ct concept definitions

  1. ITER concept definition. V.2

    International Nuclear Information System (INIS)

    1989-01-01

    Volume II of the two volumes describing the concept definition of the International Thermonuclear Experimental Reactor deals with the ITER concept in technical depth, and covers all areas of design of the ITER tokamak. Included are an assessment of the current database for design, scoping studies, rationale for concepts selection, performance flexibility, the ITER concept, the operations and experimental/testing program, ITER parameters and design phase schedule, and research and development specific to ITER. This latter includes a definition of specific research and development tasks, a division of tasks among members, specific milestones, required results, and schedules. Figs and tabs

  2. Interreligious Communication (Definition, Concepts, Situation

    Directory of Open Access Journals (Sweden)

    Vahid Safi Esfahani

    2015-12-01

    Full Text Available Abstract Religion and monotheistic beliefs are the bases of the human societies and culture and communications are the most important manifestations of these bases. About the three elements of religion, culture and communications, which act as the distinctions of human beings from other beings, and the relationship among them, many discussions have been occurred. In this article, the definitions offered for religion, culture and communication and their relationship, using the literature governing the Intercultural Communication and Cross-cultural Communication as two subjects discussed in the field of Cultural Communication and International Communication, have been reviewed and tried through a novel method to promote the level of religion from a concept usually seen as something such as race, ethnic, identity and life style under the title of international communication and cultural communication to a much higher position and place it under the title of interreligious communication. Following creation of a new field of study, many of the scholars and thinkers who are concerned about that field get together and focus of its issues and try to offer definitions and divisions about the subject. Later, after accumulation of scientific materials about different issues in the field, the human knowledge in that subject starts to develop further and in a more organized way. In this regard, first, the preferred definitions of religion, culture, communication, and Interreligious Communication will be offered. Accordingly, every society includes a meaning structure which is called culture and communication would act as an interaction tool in this system whose task is coding and decoding. Religion is considered the origin of culture and the director of communication. Based on these primary definitions, the interreligious communication is defined as: the relationship between or among the monotheistic religions based on the common understanding of religious

  3. Interreligious Communication (Definition, Concepts, Situation

    Directory of Open Access Journals (Sweden)

    Hasan Bashir

    2016-01-01

    Full Text Available Abstract Religion and monotheistic beliefs are the bases of the human societies and culture and communications are the most important manifestations of these bases. About the three elements of religion, culture and communications, which act as the distinctions of human beings from other beings, and the relationship among them, many discussions have been occurred. In this article, the definitions offered for religion, culture and communication and their relationship, using the literature governing the Intercultural Communication and Cross-cultural Communication as two subjects discussed in the field of Cultural Communication and International Communication, have been reviewed and tried through a novel method to promote the level of religion from a concept usually seen as something such as race, ethnic, identity and life style under the title of international communication and cultural communication to a much higher position and place it under the title of interreligious communication. Following creation of a new field of study, many of the scholars and thinkers who are concerned about that field get together and focus of its issues and try to offer definitions and divisions about the subject. Later, after accumulation of scientific materials about different issues in the field, the human knowledge in that subject starts to develop further and in a more organized way. In this regard, first, the preferred definitions of religion, culture, communication, and Interreligious Communication will be offered. Accordingly, every society includes a meaning structure which is called culture and communication would act as an interaction tool in this system whose task is coding and decoding. Religion is considered the origin of culture and the director of communication. Based on these primary definitions, the interreligious communication is defined as: the relationship between or among the monotheistic religions based on the common understanding of religious

  4. ITER concept definition. V.1

    International Nuclear Information System (INIS)

    1989-01-01

    Under the auspices of the International Atomic Energy Agency (IAEA), an agreement among the four parties representing the world's major fusion programs resulted in a program for conceptual design of the next logical step in the fusion program, the International Thermonuclear Experimental Reactor (ITER). The definition phase, which ended in November, 1989, is summarized in two reports: a brief summary is contained in the ITER Definition Phase Report (IAEA/ITER/DS/2); the extended technical summary and technical details of ITER are contained in this two-volume report. The first volume of this report contains the Introduction and Summary, and the remainder will appear in Volume II. In the Conceptual Design Activities phase, ITER has been defined as being a tokamak device. The basic performance parameters of ITER are given in Volume I of this report. In addition, the rationale for selection of this concept, the performance flexibility, technical issues, operations, safety, reliability, cost, and research and development needed to proceed with the design are discussed. Figs and tabs

  5. Cryogenic fluid management program flight concept definition

    Science.gov (United States)

    Kroeger, Erich

    1987-01-01

    The Lewis Research Center's cryogenic fluid management program flight concept definition is presented in viewgraph form. Diagrams are given of the cryogenic fluid management subpallet and its configuration with the Delta launch vehicle. Information is given in outline form on feasibility studies, requirements definition, and flight experiments design.

  6. Conception, definition, measuring procedure of grain size

    International Nuclear Information System (INIS)

    Yanagisawa, Kazuaki

    1976-12-01

    The conception, definition, measuring procedure of ''Grain Size'' were surveyed. A concept ''grain diameter'' was introduced after deriving a calculation formula for the grain diameter for using the Comparison (simple) and Intercept(detailed) procedure. As an example and putting into practice, the grain diameter determination was carried out by means of the Comparison procedure for a UO 2 pellet used in a densification experiment. (auth.)

  7. Automatic extraction of legal concepts and definitions

    NARCIS (Netherlands)

    Winkels, R.; Hoekstra, R.

    2012-01-01

    In this paper we present the results of an experiment in automatic concept and definition extraction from written sources of law using relatively simple natural language and standard semantic web technology. The software was tested on six laws from the tax domain.

  8. Fission Surface Power System Initial Concept Definition

    Science.gov (United States)

    2010-01-01

    Under the NASA Exploration Technology Development Program (ETDP) and in partnership with the Department of Energy (DOE), NASA has embarked on a project to develop Fission Surface Power (FSP) technology. The primary goals of the project are to 1) develop FSP concepts that meet expected surface power requirements at reasonable cost with added benefits over other options, 2) establish a hardwarebased technical foundation for FSP design concepts and reduce overall development risk, 3) reduce the cost uncertainties for FSP and establish greater credibility for flight system cost estimates, and 4) generate the key products to allow NASA decision-makers to consider FSP as a preferred option for flight development. The FSP project was initiated in 2006 as the Prometheus Program and the Jupiter Icy Moons Orbiter (JIMO) mission were phased-out. As a first step, NASA Headquarters commissioned the Affordable Fission Surface Power System Study to evaluate the potential for an affordable FSP development approach. With a cost-effective FSP strategy identified, the FSP team evaluated design options and selected a Preliminary Reference Concept to guide technology development. Since then, the FSP Preliminary Reference Concept has served as a point-of-departure for several NASA mission architecture studies examining the use of nuclear power and has provided the foundation for a series of "Pathfinder" hardware tests. The long-term technology goal is a Technology Demonstration Unit (TDU) integrated system test using full-scale components and a non-nuclear reactor simulator. The FSP team consists of Glenn Research Center (GRC), Marshall Space Flight Center (MSFC) and the DOE National Laboratories at Los Alamos (LANL), Idaho (INL), Oak Ridge (ORNL), and Sandia (SNL). The project is organized into two main elements: Concept Definition and Risk Reduction. Under Concept Definition, the team performs trade studies, develops analytical tools, and formulates system concepts. Under Risk

  9. Voluntary euthanasia: ethical concepts and definitions.

    Science.gov (United States)

    Sanders, K; Chaloner, C

    Euthanasia is a highly emotive and contentious subject, giving rise to a great deal of debate. However, despite its frequent exposure in public and professional media, there appears to be a lack of clarity about the concepts and definitions used in the euthanasia debate. This suggests that discussions on this subject are inadequately informed and ineffectual. The ethical focus of the euthanasia debate concerns the moral legitimacy of 'voluntary euthanasia'. This article provides an overview and clarification of some of the key ethical issues at the centre of that debate.

  10. Concepts for dose determination in flat-detector CT

    International Nuclear Information System (INIS)

    Kyriakou, Yiannis; Deak, Paul; Langner, Oliver; Kalender, Willi A

    2008-01-01

    Flat-detector computed tomography (FD-CT) scanners provide large irradiation fields of typically 200 mm in the cranio-caudal direction. In consequence, dose assessment according to the current definition of the computed tomography dose index CTDI L=100mm , where L is the integration length, would demand larger ionization chambers and phantoms which do not appear practical. We investigated the usefulness of the CTDI concept and practical dosimetry approaches for FD-CT by measurements and Monte Carlo (MC) simulations. An MC simulation tool (ImpactMC, VAMP GmbH, Erlangen, Germany) was used to assess the dose characteristics and was calibrated with measurements of air kerma. For validation purposes measurements were performed on an Axiom Artis C-arm system (Siemens Medical Solutions, Forchheim, Germany) equipped with a flat detector of 40 cm x 30 cm. The dose was assessed for 70 kV and 125 kV in cylindrical PMMA phantoms of 160 mm and 320 mm diameter with a varying phantom length from 150 to 900 mm. MC simulation results were compared to the values obtained with a calibrated ionization chambers of 100 mm and 250 mm length and to thermoluminesence (TLD) dose profiles. The MCs simulations were used to calculate the efficiency of the CTDI L determination with respect to the desired CTDI ∞ . Both the MC simulation results and the dose distributions obtained by MC simulation were in very good agreement with the CTDI measurements and with the reference TLD profiles, respectively, to within 5%. Standard CTDI phantoms which have a z-extent of 150 mm underestimate the dose at the center by up to 55%, whereas a z-extent of ≥600 mm appears to be sufficient for FD-CT; the baseline value of the respective profile was within 1% to the reference baseline. As expected, the measurements with ionization chambers of 100 mm and 250 mm offer a limited accuracy, whereas an increased integration length of ≥600 mm appeared to be necessary to approximate CTDI ∞ in within 1%. MC

  11. Concepts for dose determination in flat-detector CT

    Science.gov (United States)

    Kyriakou, Yiannis; Deak, Paul; Langner, Oliver; Kalender, Willi A.

    2008-07-01

    Flat-detector computed tomography (FD-CT) scanners provide large irradiation fields of typically 200 mm in the cranio-caudal direction. In consequence, dose assessment according to the current definition of the computed tomography dose index CTDIL=100 mm, where L is the integration length, would demand larger ionization chambers and phantoms which do not appear practical. We investigated the usefulness of the CTDI concept and practical dosimetry approaches for FD-CT by measurements and Monte Carlo (MC) simulations. An MC simulation tool (ImpactMC, VAMP GmbH, Erlangen, Germany) was used to assess the dose characteristics and was calibrated with measurements of air kerma. For validation purposes measurements were performed on an Axiom Artis C-arm system (Siemens Medical Solutions, Forchheim, Germany) equipped with a flat detector of 40 cm × 30 cm. The dose was assessed for 70 kV and 125 kV in cylindrical PMMA phantoms of 160 mm and 320 mm diameter with a varying phantom length from 150 to 900 mm. MC simulation results were compared to the values obtained with a calibrated ionization chambers of 100 mm and 250 mm length and to thermoluminesence (TLD) dose profiles. The MCs simulations were used to calculate the efficiency of the CTDIL determination with respect to the desired CTDI∞. Both the MC simulation results and the dose distributions obtained by MC simulation were in very good agreement with the CTDI measurements and with the reference TLD profiles, respectively, to within 5%. Standard CTDI phantoms which have a z-extent of 150 mm underestimate the dose at the center by up to 55%, whereas a z-extent of >=600 mm appears to be sufficient for FD-CT; the baseline value of the respective profile was within 1% to the reference baseline. As expected, the measurements with ionization chambers of 100 mm and 250 mm offer a limited accuracy, whereas an increased integration length of >=600 mm appeared to be necessary to approximate CTDI∞ in within 1%. MC simulations

  12. Contrasting lexical similarity and formal definitions in SNOMED CT: consistency and implications.

    Science.gov (United States)

    Agrawal, Ankur; Elhanan, Gai

    2014-02-01

    To quantify the presence of and evaluate an approach for detection of inconsistencies in the formal definitions of SNOMED CT (SCT) concepts utilizing a lexical method. Utilizing SCT's Procedure hierarchy, we algorithmically formulated similarity sets: groups of concepts with similar lexical structure of their fully specified name. We formulated five random samples, each with 50 similarity sets, based on the same parameter: number of parents, attributes, groups, all the former as well as a randomly selected control sample. All samples' sets were reviewed for types of formal definition inconsistencies: hierarchical, attribute assignment, attribute target values, groups, and definitional. For the Procedure hierarchy, 2111 similarity sets were formulated, covering 18.1% of eligible concepts. The evaluation revealed that 38 (Control) to 70% (Different relationships) of similarity sets within the samples exhibited significant inconsistencies. The rate of inconsistencies for the sample with different relationships was highly significant compared to Control, as well as the number of attribute assignment and hierarchical inconsistencies within their respective samples. While, at this time of the HITECH initiative, the formal definitions of SCT are only a minor consideration, in the grand scheme of sophisticated, meaningful use of captured clinical data, they are essential. However, significant portion of the concepts in the most semantically complex hierarchy of SCT, the Procedure hierarchy, are modeled inconsistently in a manner that affects their computability. Lexical methods can efficiently identify such inconsistencies and possibly allow for their algorithmic resolution. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Description logics with approximate definitions precise modeling of vague concepts

    NARCIS (Netherlands)

    Schlobach, Stefan; Klein, Michel; Peelen, Linda

    2007-01-01

    We extend traditional Description Logics (DL) with a simple mechanism to handle approximate concept definitions in a qualitative way. Often, for example in medical applications, concepts are not definable in a crisp way but can fairly exhaustively be constrained through a particular sub- and a

  14. Identifying problematic concepts in SNOMED CT using a lexical approach.

    Science.gov (United States)

    Agrawal, Ankur; Perl, Yehoshua; Elhanan, Gai

    2013-01-01

    SNOMED CT (SCT) has been endorsed as a premier clinical terminology by many organizations with a perceived use within electronic health records and clinical information systems. However, there are indications that, at the moment, SCT is not optimally structured for its intended use by healthcare practitioners. A study is conducted to investigate the extent of inconsistencies among the concepts in SCT. A group auditing technique to improve the quality of SCT is introduced that can help identify problematic concepts with a high probability. Positional similarity sets are defined, which are groups of concepts that are lexically similar and the position of the differing word in the fully specified name of the concepts of a set that correspond to each other. A manual auditing of a sample of such sets found 38% of the sets exhibiting one or more inconsistent concepts. Group auditing techniques such as this can thus be very helpful to assure the quality of SCT, which will help expedite its adoption as a reference terminology for clinical purposes.

  15. Digital games in medical education: Key terms, concepts, and definitions.

    Science.gov (United States)

    Bigdeli, Shoaleh; Kaufman, David

    2017-01-01

    Introduction: Game-based education is fast becoming a key instrument in medical education. Method: In this study, papers related to games were filtered and limited to full-text peer-reviewed published in English. Results: To the best of researchers' knowledge, the concepts used in the literature are varied and distinct, and the literature is not conclusive on the definition of educational games for medical education. Conclusion: This paper attempts to classify terms, concepts and definitions common to gamification in medical education.

  16. Inequalities in health: definitions, concepts, and theories

    Directory of Open Access Journals (Sweden)

    Mariana C. Arcaya

    2015-06-01

    Full Text Available Individuals from different backgrounds, social groups, and countries enjoy different levels of health. This article defines and distinguishes between unavoidable health inequalities and unjust and preventable health inequities. We describe the dimensions along which health inequalities are commonly examined, including across the global population, between countries or states, and within geographies, by socially relevant groupings such as race/ethnicity, gender, education, caste, income, occupation, and more. Different theories attempt to explain group-level differences in health, including psychosocial, material deprivation, health behavior, environmental, and selection explanations. Concepts of relative versus absolute; dose–response versus threshold; composition versus context; place versus space; the life course perspective on health; causal pathways to health; conditional health effects; and group-level versus individual differences are vital in understanding health inequalities. We close by reflecting on what conditions make health inequalities unjust, and to consider the merits of policies that prioritize the elimination of health disparities versus those that focus on raising the overall standard of health in a population.

  17. Lay Worker Health Literacy: A Concept Analysis and Operational Definition.

    Science.gov (United States)

    Cadman, Kathleen Paco

    2017-10-01

    The concept of lay worker health literacy is created by concurrently analyzing and synthesizing two intersecting concepts, lay workers and health literacy. Articulation of this unique intersection is the result of implementing a simplified Wilson's Concept Analysis Procedure. This process incorporates the following components: a) selecting a concept, b) determining the aims/purposes of analysis, c) identifying all uses of the concept, d) determining defining attributes, e) identifying a model case, f) identifying borderline, related, contrary, and illegitimate cases, g) identifying antecedents and consequences, and h) defining empirical referents. Furthermore, as current literature provides no operational definition for lay worker health literacy, one is created to contribute cohesion to the concept. © 2017 Wiley Periodicals, Inc.

  18. Space station high gain antenna concept definition and technology development

    Science.gov (United States)

    Wade, W. D.

    1972-01-01

    The layout of a technology base is reported from which a mechanically gimballed, directional antenna can be developed to support a manned space station proposed for the late 1970's. The effort includes the concept definition for the antenna assembly, an evaluation of available technology, the design of critical subassemblies and the design of critical subassembly tests.

  19. Definition and Evaluation of Bus and Truck Automation Operations Concepts

    OpenAIRE

    Tsao, H.-S. Jacob; Botha, Jan L.

    2002-01-01

    Traffic congestion will continue to worsen and likely worsen at a faster rate than ever. People throughput and freight throughput have become critical issues for California and the rest of the nation. PATH has been funding a one-year research project entitled "Definition and Evaluation of Bus and Truck Automation Operations Concepts," proposed by the authors. This report summarizes the results of the research project achieved during the first six months. During those six months, we reviewed l...

  20. Molten Salt: Concept Definition and Capital Cost Estimate

    Energy Technology Data Exchange (ETDEWEB)

    Stoddard, Larry [Black & Veatch, Kansas City, MO (United States); Andrew, Daniel [Black & Veatch, Kansas City, MO (United States); Adams, Shannon [Black & Veatch, Kansas City, MO (United States); Galluzzo, Geoff [Black & Veatch, Kansas City, MO (United States)

    2016-06-30

    The Department of Energy’s (DOE’s) Office of Renewable Power (ORP) has been tasked to provide effective program management and strategic direction for all of the DOE’s Energy Efficiency & Renewable Energy’s (EERE’s) renewable power programs. The ORP’s efforts to accomplish this mission are aligned with national energy policies, DOE strategic planning, EERE’s strategic planning, Congressional appropriation, and stakeholder advice. ORP is supported by three renewable energy offices, of which one is the Solar Energy Technology Office (SETO) whose SunShot Initiative has a mission to accelerate research, development and large scale deployment of solar technologies in the United States. SETO has a goal of reducing the cost of Concentrating Solar Power (CSP) by 75 percent of 2010 costs by 2020 to reach parity with base-load energy rates, and to reduce costs 30 percent further by 2030. The SunShot Initiative is promoting the implementation of high temperature CSP with thermal energy storage allowing generation during high demand hours. The SunShot Initiative has funded significant research and development work on component testing, with attention to high temperature molten salts, heliostats, receiver designs, and high efficiency high temperature supercritical CO2 (sCO2) cycles. DOE retained Black & Veatch to support SETO’s SunShot Initiative for CSP solar power tower technology in the following areas: 1. Concept definition, including costs and schedule, of a flexible test facility to be used to test and prove components in part to support financing. 2. Concept definition, including costs and schedule, of an integrated high temperature molten salt (MS) facility with thermal energy storage and with a supercritical CO2 cycle generating approximately 10MWe. 3. Concept definition, including costs and schedule, of an integrated high temperature falling particle facility with thermal energy storage and with a supercritical CO2

  1. On the Concept and Definition of Terrorism Risk.

    Science.gov (United States)

    Aven, Terje; Guikema, Seth

    2015-12-01

    In this article, we provide some reflections on how to define and understand the concept of terrorism risk in a professional risk assessment context. As a basis for this discussion we introduce a set of criteria that we believe should apply to any conceptualization of terrorism risk. These criteria are based on both criteria used in other areas of risk analysis and our experience with terrorism risk analysis. That is, these criteria offer our perspective. We show that several of the suggested perspectives and definitions have weaknesses in relation to these criteria. A main problem identified is the idea that terrorism risk can be conceptualized as a function of probability and consequence, not as a function of the interactions between adaptive individuals and organizations. We argue that perspectives based solely on probability and consequence should be used cautiously or not at all because they fail to reflect the essential features of the concept of terrorism risk, the threats and attacks, their consequences, and the uncertainties, all in the context of adaptation by the adversaries. These three elements should in our view constitute the main pillars of the terrorism risk concept. From this concept we can develop methods for assessing the risk by identifying a set of threats, attacks, and consequence measures associated with the possible outcome scenarios together with a description of the uncertainties and interactions between the adversaries. © 2015 Society for Risk Analysis.

  2. Multidetector CT in children: current concepts and dose reduction strategies

    Energy Technology Data Exchange (ETDEWEB)

    Nievelstein, Rutger A.J.; Dam, Ingrid M. van [University Medical Centre Utrecht, Department of Pediatric Radiology, Wilhelmina Children' s Hospital, E01.132, P.O. Box 85500, Utrecht (Netherlands); Molen, Aart J. van der [Leiden University Medical Centre, Department of Radiology, C-2S, Leiden (Netherlands)

    2010-08-15

    The recent technical development of multidetector CT (MDCT) has contributed to a substantial increase in its diagnostic applications and accuracy in children. A major drawback of MDCT is the use of ionising radiation with the risk of inducing secondary cancer. Therefore, justification and optimisation of paediatric MDCT is of great importance in order to minimise these risks (''as low as reasonably achievable'' principle). This review will focus on all technical and non-technical aspects relevant for paediatric MDCT optimisation and includes guidelines for radiation dose level-based CT protocols. (orig.)

  3. Multidetector CT in children: current concepts and dose reduction strategies

    International Nuclear Information System (INIS)

    Nievelstein, Rutger A.J.; Dam, Ingrid M. van; Molen, Aart J. van der

    2010-01-01

    The recent technical development of multidetector CT (MDCT) has contributed to a substantial increase in its diagnostic applications and accuracy in children. A major drawback of MDCT is the use of ionising radiation with the risk of inducing secondary cancer. Therefore, justification and optimisation of paediatric MDCT is of great importance in order to minimise these risks (''as low as reasonably achievable'' principle). This review will focus on all technical and non-technical aspects relevant for paediatric MDCT optimisation and includes guidelines for radiation dose level-based CT protocols. (orig.)

  4. A DEFINITION OF AUTHENTICITY CONCEPT IN CONSERVATION OF CULTURAL LANDSCAPES

    Directory of Open Access Journals (Sweden)

    Somayeh Fadaei Nezhad

    2015-03-01

    Full Text Available Cultural landscape can be defined as the result of human interaction with nature over time, which has led to the formation of the many and diverse layers of value. Currently, the UNESCO World Heritage Centre has a unique role among other scientific associations. In recent years, the World Heritage Center has put efforts into developing a framework and measures for evaluation and management of cultural landscapes. Moreover, the concept of authenticity; as the transmitter of values and significance of cultural landscape, is considered as the key component in the process of cultural landscape conservation. A lot of scientific resources have pointed out the importance of authenticity in the process of conserving cultural landscapes. However, the role of authenticity within the domain of conservation of cultural landscapes has received little attention. One of the main reasons can be lack of adaptation between conventional definitions of UNESCO and international documents concerning the authenticity for including the flexible and dynamic structure of cultural landscapes around the world. Therefore, this paper seeks to explore and develop a flexible framework in order to redefine the concept of authenticity in relation to cultural landscapes, which has some overlaps with UNESCO definitions despite its differences. For developing this framework, Iranian-Islamic philosophy of Mollasadra is applied and described with some examples of cultural landscapes in Iran.

  5. Concept definition of traffic flow wide-area surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.; Ferrell, R.K.; Kercel, S.W.

    1994-07-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret large spatial projections of data originating from multiple sensor suites. The intent of the Wide-Area Surveillance (WAS) Project is to build upon this concept and define the operational specifications and characteristics of a Traffic Flow Wide-Area Surveillance (TFWAS) system in terms of traffic management and control. In doing so, the functional capabilities of a TFWAS will be mapped onto an operational profile that is consistent with the Federal Highway Administration`s Intelligent Vehicle Highway System. This document provides the underlying foundation of this work by offering a concept definition for the TFWAS system. It concentrates on answering the question: ``What is the system?`` In doing so, the report develops a hierarchy of specialized definitions.

  6. PET/CT and vascular disease: Current concepts

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcanti Filho, Jose Leite Gondim; Souza Leao Lima, Ronaldo de [CDPI and Multi-Imagem Clinics, Rio de Janeiro (Brazil); Department of Radiology, Rio de Janeiro Federal University (UFRJ), Rio de Janeiro (Brazil); Souza Machado Neto, Luiz de [CDPI and Multi-Imagem Clinics, Rio de Janeiro (Brazil); Kayat Bittencourt, Leonardo, E-mail: lkayat@terra.com.br [CDPI and Multi-Imagem Clinics, Rio de Janeiro (Brazil); Department of Radiology, Rio de Janeiro Federal University (UFRJ), Rio de Janeiro (Brazil); Cortes Domingues, Romeu [CDPI and Multi-Imagem Clinics, Rio de Janeiro (Brazil); Fonseca, Lea Mirian Barbosa da [CDPI and Multi-Imagem Clinics, Rio de Janeiro (Brazil); Department of Radiology, Rio de Janeiro Federal University (UFRJ), Rio de Janeiro (Brazil)

    2011-10-15

    Since its introduction in 2001, positron emission tomography associated to computed tomography (PET/CT) has been established as a standard tool in cancer evaluation. Being a multimodality imaging method, it combines in a single session the sensitivity granted by PET for detection of molecular targets within the picomolar range, with an underlying submilimetric resolution inherent to CT, that can precisely localize the PET findings. In this last decade, there have been new insights regarding the pathophysiology of atherosclerosis, particularly about plaque rupture and vascular remodeling. This has increased the interest for research on PET/CT in vascular diseases as a potential new diagnostic tool, since some PET molecular targets could identify diseases before the manifestation of gross anatomic features. In this review, we will describe the current applications of PET/CT in vascular diseases, emphasizing its usefulness in the settings of vasculitis, aneurysms, vascular graft infection, aortic dissection, and atherosclerosis/plaque vulnerability. Although not being properly peripheral vascular conditions, ischemic cardiovascular disease and cerebrovascular disease will be briefly addressed as well, due to their widespread prevalence and importance.

  7. 3D intrathoracic region definition and its application to PET-CT analysis

    Science.gov (United States)

    Cheirsilp, Ronnarit; Bascom, Rebecca; Allen, Thomas W.; Higgins, William E.

    2014-03-01

    Recently developed integrated PET-CT scanners give co-registered multimodal data sets that offer complementary three-dimensional (3D) digital images of the chest. PET (positron emission tomography) imaging gives highly specific functional information of suspect cancer sites, while CT (X-ray computed tomography) gives associated anatomical detail. Because the 3D CT and PET scans generally span the body from the eyes to the knees, accurate definition of the intrathoracic region is vital for focusing attention to the central-chest region. In this way, diagnostically important regions of interest (ROIs), such as central-chest lymph nodes and cancer nodules, can be more efficiently isolated. We propose a method for automatic segmentation of the intrathoracic region from a given co-registered 3D PET-CT study. Using the 3D CT scan as input, the method begins by finding an initial intrathoracic region boundary for a given 2D CT section. Next, active contour analysis, driven by a cost function depending on local image gradient, gradient-direction, and contour shape features, iteratively estimates the contours spanning the intrathoracic region on neighboring 2D CT sections. This process continues until the complete region is defined. We next present an interactive system that employs the segmentation method for focused 3D PET-CT chest image analysis. A validation study over a series of PET-CT studies reveals that the segmentation method gives a Dice index accuracy of less than 98%. In addition, further results demonstrate the utility of the method for focused 3D PET-CT chest image analysis, ROI definition, and visualization.

  8. The influence of respiratory motion on CT image volume definition

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Romero, Ruth, E-mail: rrromero@salud.madrid.org; Castro-Tejero, Pablo, E-mail: pablo.castro@salud.madrid.org [Servicio de Radiofísica y Protección Radiológica, Hospital Universitario Puerta de Hierro Majadahonda, 28222 Madrid (Spain)

    2014-04-15

    Purpose: Radiotherapy treatments are based on geometric and density information acquired from patient CT scans. It is well established that breathing motion during scan acquisition induces motion artifacts in CT images, which can alter the size, shape, and density of a patient's anatomy. The aim of this work is to examine and evaluate the impact of breathing motion on multislice CT imaging with respiratory synchronization (4DCT) and without it (3DCT). Methods: A specific phantom with a movable insert was used. Static and dynamic phantom acquisitions were obtained with a multislice CT. Four sinusoidal breath patterns were simulated to move known geometric structures longitudinally. Respiratory synchronized acquisitions (4DCT) were performed to generate images during inhale, intermediate, and exhale phases using prospective and retrospective techniques. Static phantom data were acquired in helical and sequential mode to define a baseline for each type of respiratory 4DCT technique. Taking into account the fact that respiratory 4DCT is not always available, 3DCT helical image studies were also acquired for several CT rotation periods. To study breath and acquisition coupling when respiratory 4DCT was not performed, the beginning of the CT image acquisition was matched with inhale, intermediate, or exhale respiratory phases, for each breath pattern. Other coupling scenarios were evaluated by simulating different phantom and CT acquisition parameters. Motion induced variations in shape and density were quantified by automatic threshold volume generation and Dice similarity coefficient calculation. The structure mass center positions were also determined to make a comparison with their theoretical expected position. Results: 4DCT acquisitions provided volume and position accuracies within ±3% and ±2 mm for structure dimensions >2 cm, breath amplitude ≤15 mm, and breath period ≥3 s. The smallest object (1 cm diameter) exceeded 5% volume variation for the breath

  9. Mars power system concept definition study. Volume 1: Study results

    Science.gov (United States)

    Littman, Franklin D.

    1994-01-01

    A preliminary top level study was completed to define power system concepts applicable to Mars surface applications. This effort included definition of power system requirements and selection of power systems with the potential for high commonality. These power systems included dynamic isotope, Proton Exchange Membrane (PEM) regenerative fuel cell, sodium sulfur battery, photovoltaic, and reactor concepts. Design influencing factors were identified. Characterization studies were then done for each concept to determine system performance, size/volume, and mass. Operations studies were done to determine emplacement/deployment maintenance/servicing, and startup/shutdown requirements. Technology development roadmaps were written for each candidate power system (included in Volume 2). Example power system architectures were defined and compared on a mass basis. The dynamic isotope power system and nuclear reactor power system architectures had significantly lower total masses than the photovoltaic system architectures. Integrated development and deployment time phasing plans were completed for an example DIPS and reactor architecture option to determine the development strategies required to meet the mission scenario requirements.

  10. Design concepts of definitive disposal for high level radioactive wastes

    International Nuclear Information System (INIS)

    Badillo A, V.E.; Alonso V, G.

    2007-01-01

    It is excessively known the importance about finding a solution for the handling and disposition of radioactive waste of all level. However, the polemic is centered in the administration of high level radioactive waste and the worn out fuel, forgetting that the more important volumes of waste its are generated in the categories of low level wastes or of very low level. Depending on the waste that will be confined and of the costs, several technological modalities of definitive disposition exist, in function of the depth of the confinement. The concept of deep geologic storage, technological option proposed more than 40 years ago, it is a concept of isolation of waste of long half life placed in a deep underground installation dug in geologic formations that are characterized by their high stability and their low flow of underground water. In the last decades, they have registered countless progresses in technical and scientific aspects of the geologic storage, making it a reliable technical solution supported with many years of scientific work carried out by numerous institutions in the entire world. In this work the design concepts that apply some countries for the high level waste disposal that its liberate heat are revised and the different geologic formations that have been considered for the storage of this type of wastes. (Author)

  11. Reproducibility of CT bone dosimetry: Operator versus automated ROI definition

    International Nuclear Information System (INIS)

    Louis, O.; Luypaert, R.; Osteaux, M.; Kalender, W.

    1988-01-01

    Intrasubject reproducibility with repeated determination of vertebral mineral density from a given set of CT images was investigated. The region of interest (ROI) in 10 patient scans was selected by four independent operators either manually or with an automated procedure separating cortical and spongeous bone, the operators being requested to interact in ROI selection. The mean intrasubject variation was found to be much lower with the automated process (0.3 to 0.6%) than with the conventional method (2.5 to 5.2%). In a second study, 10 patients were examined twice to determine the reproducibility of CT slice selection by the operator. The errors were of the same order of magnitude as in ROI selection. (orig.)

  12. Auditing SNOMED CT hierarchical relations based on lexical features of concepts in non-lattice subgraphs.

    Science.gov (United States)

    Cui, Licong; Bodenreider, Olivier; Shi, Jay; Zhang, Guo-Qiang

    2018-02-01

    We introduce a structural-lexical approach for auditing SNOMED CT using a combination of non-lattice subgraphs of the underlying hierarchical relations and enriched lexical attributes of fully specified concept names. Our goal is to develop a scalable and effective approach that automatically identifies missing hierarchical IS-A relations. Our approach involves 3 stages. In stage 1, all non-lattice subgraphs of SNOMED CT's IS-A hierarchical relations are extracted. In stage 2, lexical attributes of fully-specified concept names in such non-lattice subgraphs are extracted. For each concept in a non-lattice subgraph, we enrich its set of attributes with attributes from its ancestor concepts within the non-lattice subgraph. In stage 3, subset inclusion relations between the lexical attribute sets of each pair of concepts in each non-lattice subgraph are compared to existing IS-A relations in SNOMED CT. For concept pairs within each non-lattice subgraph, if a subset relation is identified but an IS-A relation is not present in SNOMED CT IS-A transitive closure, then a missing IS-A relation is reported. The September 2017 release of SNOMED CT (US edition) was used in this investigation. A total of 14,380 non-lattice subgraphs were extracted, from which we suggested a total of 41,357 missing IS-A relations. For evaluation purposes, 200 non-lattice subgraphs were randomly selected from 996 smaller subgraphs (of size 4, 5, or 6) within the "Clinical Finding" and "Procedure" sub-hierarchies. Two domain experts confirmed 185 (among 223) suggested missing IS-A relations, a precision of 82.96%. Our results demonstrate that analyzing the lexical features of concepts in non-lattice subgraphs is an effective approach for auditing SNOMED CT. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Supercritical Carbon Dioxide Power Generation System Definition: Concept Definition and Capital Cost Estimate

    Energy Technology Data Exchange (ETDEWEB)

    Stoddard, Larry [Black & Veatch, Kansas City, MO (United States); Galluzzo, Geoff [Black & Veatch, Kansas City, MO (United States); Andrew, Daniel [Black & Veatch, Kansas City, MO (United States); Adams, Shannon [Black & Veatch, Kansas City, MO (United States)

    2016-06-30

    The Department of Energy’s (DOE’s) Office of Renewable Power (ORP) has been tasked to provide effective program management and strategic direction for all of the DOE’s Energy Efficiency & Renewable Energy’s (EERE’s) renewable power programs. The ORP’s efforts to accomplish this mission are aligned with national energy policies, DOE strategic planning, EERE’s strategic planning, Congressional appropriation, and stakeholder advice. ORP is supported by three renewable energy offices, of which one is the Solar Energy Technology Office (SETO) whose SunShot Initiative has a mission to accelerate research, development and large scale deployment of solar technologies in the United States. SETO has a goal of reducing the cost of Concentrating Solar Power (CSP) by 75 percent of 2010 costs by 2020 to reach parity with base-load energy rates, and 30 percent further reductions by 2030. The SunShot Initiative is promoting the implementation of high temperature CSP with thermal energy storage allowing generation during high demand hours. The SunShot Initiative has funded significant research and development work on component testing, with attention to high temperature molten salts, heliostats, receiver designs, and high efficiency high temperature supercritical CO2 (sCO2) cycles. DOE retained Black & Veatch to support SETO’s SunShot Initiative for CSP solar power tower technology in the following areas: 1. Concept definition, including costs and schedule, of a flexible test facility to be used to test and prove components in part to support financing. 2. Concept definition, including costs and schedule, of an integrated high temperature molten salt (MS) facility with thermal energy storage and with a supercritical CO2 cycle generating approximately 10MWe. 3. Concept definition, including costs and schedule, of an integrated high temperature falling particle facility with thermal energy storage and with a supercritical CO2 cycle

  14. Honeycombing on CT; its definition, pathologic correlation, and future direction of its diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Johkoh, Takeshi, E-mail: johkoht@aol.com [Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, 3-1 Kurumazuka, Itami, Hyogo, 664-8533 (Japan); Sakai, Fumikazu [Department of Diagnostic Radiology, Saitama International Medical Center, Saitama Medical University, Hidaka (Japan); Noma, Satoshi [Department of Radiology, Tenri Hospital, Tenri (Japan); Akira, Masanori [Department of Radiology, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai (Japan); Fujimoto, Kiminori [Department of Radiology and Center for Diagnostic Imaging, Kurume University School of Medicine, Kurume (Japan); Watadani, Takeyuki [Department of Radiology, University of Tokyo, Tokyo (Japan); Sugiyama, Yukihiko [Department of Internal Medicine, Jichi Medical University, Shimotsuke (Japan)

    2014-01-15

    Honeycombing on CT is the clue for the diagnosis of usual interstitial pneumonia (UIP) and its hallmark. According to the ATS-ERS-JRS-ALAT 2010 guideline, the patients with honeycombing on CT can be diagnosed as UIP without surgical biopsy. On CT scans, it is defined as clustered cystic airspaces, typically of comparable diameters of the order of 3–10 mm, which are usually subpleural and have well-defined walls. Pathologically, honeycombing consists of both collapsing of multiple fibrotic alveoli and dilation of alveolar duct and lumen Although the definition of honeycombing seems to be strict, recognition of honeycombing on CT is various among each observer Because typical honeycombing is frequently observed in the patients with UIP, we should judge clustered cysts as honeycombing when a diagnosis of UIP is suspected.

  15. Cortical region of interest definition on SPECT brain images using X-ray CT registration

    Energy Technology Data Exchange (ETDEWEB)

    Tzourio, N.; Sutton, D. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot); Joliot, M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot INSERM, Orsay (France)); Mazoyer, B.M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot Antenne d' Information Medicale, C.H.U. Bichat, Paris (France)); Charlot, V. (Hopital Louis Mourier, Colombes (France). Service de Psychiatrie); Salamon, G. (CHU La Timone, Marseille (France). Service de Neuroradiologie)

    1992-11-01

    We present a method for brain single photon emission computed tomography (SPECT) analysis based on individual registration of anatomical (CT) and functional ([sup 133]Xe regional cerebral blood flow) images and on the definition of three-dimensional functional regions of interest. Registration of CT and SPECT is performed through adjustment of CT-defined cortex limits to the SPECT image. Regions are defined by sectioning a cortical ribbon on the CT images, copied over the SPECT images and pooled through slices to give 3D cortical regions of interest. The proposed method shows good intra- and interobserver reproducibility (regional intraclass correlation coefficient [approx equal]0.98), and good accuracy in terms of repositioning ([approx equal]3.5 mm) as compared to the SPECT image resolution (14 mm). The method should be particularly useful for analysing SPECT studies when variations in brain anatomy (normal or abnormal) must be accounted for. (orig.).

  16. Diagnostic value of F18-FDG PET/CT in patients with the revised definition of fever of unknown origin

    DEFF Research Database (Denmark)

    Prakash, Vineet; Ketharanathan, Nagulabaskaran; Lorenz, Eleanor

    2009-01-01

    Objectives: Fever of unknown origin (FUO) is an increasingly accepted indication for PET/CT where it has a relatively high diagnostic yield. This study assesses its diagnostic value for the revised definition of FUO. Methods: The revised definition of FUO is fever of greater than 38.3C for more...... than 3 weeks duration and an uncertain diagnosis after comprehensive evaluation as an inpatient or outpatient for a minimum of 3 days or 3 outpatient visits, having excluded immunocompromised states. 59 patients (pts) (F=35, age 18-92) with this definition underwent PET with full diagnostic contrast......), neoplasm (6 pts) and drug fever (1 pt). Before ordering a PET/CT, conventional CT or MRI was performed in 43 pts. We considered that a PET/CT was essential to establish the final diagnosis in 15/43 pts (35%) with inconclusive CT or MRI. Conclusions: 18F-FDG PET/CT contributed to establishing a final...

  17. Orbital transfer vehicle concept definition and system analysis study. Volume 2: OTV concept definition and evaluation. Book 1: Mission and system requirements

    Science.gov (United States)

    Kofal, Allen E.

    1987-01-01

    The mission and system requirements for the concept definition and system analysis of the Orbital Transfer Vehicle (OTV) are established. The requirements set forth constitute the single authority for the selection, evaluation, and optimization of the technical performance and design of the OTV. This requirements document forms the basis for the Ground and Space Based OTV concept definition analyses and establishes the physical, functional, performance and design relationships to STS, Space Station, Orbital Maneuvering Vehicle (OMV), and payloads.

  18. Multiple organ definition in CT using a Bayesian approach for 3D model fitting

    Science.gov (United States)

    Boes, Jennifer L.; Weymouth, Terry E.; Meyer, Charles R.

    1995-08-01

    Organ definition in computed tomography (CT) is of interest for treatment planning and response monitoring. We present a method for organ definition using a priori information about shape encoded in a set of biometric organ models--specifically for the liver and kidney-- that accurately represents patient population shape information. Each model is generated by averaging surfaces from a learning set of organ shapes previously registered into a standard space defined by a small set of landmarks. The model is placed in a specific patient's data set by identifying these landmarks and using them as the basis for model deformation; this preliminary representation is then iteratively fit to the patient's data based on a Bayesian formulation of the model's priors and CT edge information, yielding a complete organ surface. We demonstrate this technique using a set of fifteen abdominal CT data sets for liver surface definition both before and after the addition of a kidney model to the fitting; we demonstrate the effectiveness of this tool for organ surface definition in this low-contrast domain.

  19. The Use of SNOMED CT for Representing Concepts Used in Preoperative Guidelines

    NARCIS (Netherlands)

    Ahmadian, Leila; de Keizer, Nicolette F.; Cornet, Ronald

    2009-01-01

    The use of guidelines to improve quality of care depends on presenting them in a standard machine-interpretable form and using common terms in guidelines as well as in patient records. In this study, the use of SNOMED CT for representing concepts used in preoperative assessment guidelines was

  20. A three-dimensional CT-based target definition for elective irradiation of the neck

    International Nuclear Information System (INIS)

    Nowak, Peter J.C.M.; Wijers, Oda B.; Lagerwaard, Frank J.; Levendag, Peter C.

    1999-01-01

    Introduction: Elective treatment of the clinically node-negative neck by radiation results in excellent control rates. However, radiation therapy with its organ-preserving properties is not without morbidity. Side effects of elective neck irradiation are mainly due to damage of the major and minor salivary glands, resulting in the dry mouth syndrome. Given that RT is the preferred treatment modality in case of elective treatment of the neck in many institutions, it is of utmost importance to try and reduce the associated sequelae of RT. Material and Methods: With the introduction of CT-planning systems and the development of 3D conformal radiation therapy (3D CRT) techniques, it has become feasible to deliver adequate doses of radiation to the target (neck) and at the same time saving (parts of) the salivary glands from doses beyond tolerance. A prerequisite for these techniques is that they require a precise knowledge of the target (i.e., of the elective neck) on CT. To be able to correlate borders of the surgical levels in the neck (I-VI) with structures seen on CT, an anatomical study, using two fixed (phenol, formaldehyde) human cadavers, was performed. Subsequently, the 6 potential lymph node regions in the neck on CT were defined. Results and Discussion: The reference for the current 3D CT-based definition of the lymph node regions in the neck is the official report of the American Academy of Otolaryngology, describing, based on surgical anatomy, the lymph node groups in the neck by Levels I-VI. The present investigation depicts reproducible landmarks on transversal CT images, corresponding to anatomical reference structures known from surgical levels (I-VI) and, this way, CT-based lymph node regions (1-6) were constructed

  1. Integrated technology rotor/flight research rotor hub concept definition

    Science.gov (United States)

    Dixon, P. G. C.

    1983-01-01

    Two variations of the helicopter bearingless main rotor hub concept are proposed as bases for further development in the preliminary design phase of the Integrated Technology Rotor/Flight Research Rotor (ITR/FRR) program. This selection was the result of an evaluation of three bearingless hub concepts and two articulated hub concepts with elastomeric bearings. The characteristics of each concept were evaluated by means of simplified methodology. These characteristics included the assessment of stability, vulnerability, weight, drag, cost, stiffness, fatigue life, maintainability, and reliability.

  2. Satellite Power Systems (SPS) concept definition study. Volume 6: SPS technology requirements and verification

    Science.gov (United States)

    Hanley, G.

    1978-01-01

    Volume 6 of the SPS Concept Definition Study is presented and also incorporates results of NASA/MSFC in-house effort. This volume includes a supporting research and technology summary. Other volumes of the final report that provide additional detail are as follows: (1) Executive Summary; (2) SPS System Requirements; (3) SPS Concept Evolution; (4) SPS Point Design Definition; (5) Transportation and Operations Analysis; and Volume 7, SPS Program Plan and Economic Analysis.

  3. Zero-gravity cloud physics laboratory: Experiment program definition and preliminary laboratory concept studies

    Science.gov (United States)

    Eaton, L. R.; Greco, E. V.

    1973-01-01

    The experiment program definition and preliminary laboratory concept studies on the zero G cloud physics laboratory are reported. This program involves the definition and development of an atmospheric cloud physics laboratory and the selection and delineations of a set of candidate experiments that must utilize the unique environment of zero gravity or near zero gravity.

  4. Definitions of Physical Concepts: A Study of Physics Teachers' Knowledge and Views. Research Report

    Science.gov (United States)

    Galili, Igal; Lehavi, Yaron

    2006-01-01

    A study was made of the ability of a population of high-school physics teachers to define physics concepts and of their views regarding the importance of such definitions. It was found possible to arrange the definitions accumulated in categories, and the classification so obtained was consonant with that of the philosophy of science. Although the…

  5. An Investigation of K-8 Preservice Teachers' Concept Images and Mathematical Definitions of Polygons

    Science.gov (United States)

    Ward, Robin A.

    2004-01-01

    In this paper, the author presents a study which explored K-8 preservice teachers' concept images and mathematical definitions of polygons. This study was carried out in which K-8 teacher candidates enrolled in an elementary mathematics content course were asked to sort, identify, and provide definitions of such shapes including triangles,…

  6. A simplified CT-based definition of the lymph node levels in the node negative neck

    International Nuclear Information System (INIS)

    Wijers, O.B.; Levendag, P.C.; Tan, T.; Dieren, E.B. van; Sornsen de Koste, J. van; Est, H. van der; Senan, S.; Nowak, P.J.C.M.

    1999-01-01

    Using three dimensional (3D) conformal radiotherapy (CRT) techniques for elective neck irradiation (ENI) may allow for local disease control to be maintained while diminishing xerostomia by eliminating major salivary glands (or parts thereof) from the treatment portals. The standardization of CT based target volumes for the clinically negative (elective) neck is a prerequisite for 3DCRT. The aim of the present study was to substantially modify an existing ('original') CT-based protocol for the delineation of the neck tar-et volume, into a more practical ('simplified') protocol. This will allow for rapid contouring and the implementation of conformal ENI in routine clinical procedures. An earlier ('original') version of the CT-based definition for elective neck node re-ions 2-5 was re-evaluated, using 15 planning CT scans of previously treated patients. The contouring guidelines were simplified by (1) using a smaller number of easily identifiable soft tissue- and bony anatomical landmarks, which in turn had to be identified in only a limited number of CT slices, and (2) by subsequently interpolating the contoured lymph node regions. The adequacy of target coverage and the sparing using both 'original' and 'simplified' delineation protocols was evaluated by DVH analysis after contouring the primary tumor, the neck and the major salivary glands in a patient with supraglottic laryngeal (SGL) carcinoma who was treated using a 3DCRT technique. The BEV projections of the 'original' and the 'simplified' versions of the 3D elective neck target showed good agreement and were found to be reproducible. The DVH's of the target and parotid glands were not significantly different using both contouring protocols. The 'simplified' protocol for the delineation of the 3D elective neck target produced both comparable target coverage and sparing of the major salivary glands. When used together with an interpolation program, this 'simplified' protocol substantial reduced the contouring

  7. Informatics with Systems Science and Cybernetics--Concepts and Definitions.

    Science.gov (United States)

    Samuelson, Kjell

    This dictionary defines information science, computer science, systems theory, and cybernetic terms in English and provides the Swedish translation of each term. An index of Swedish terms refers the user to the page where the English equivalent and definition appear. Most of the 38 references listed are in English. (RAA)

  8. Auditing description-logic-based medical terminological systems by detecting equivalent concept definitions

    NARCIS (Netherlands)

    Cornet, Ronald; Abu-Hanna, Ameen

    2008-01-01

    OBJECTIVE: To specify and evaluate a method for auditing medical terminological systems (TSs) based on detecting concepts with equivalent definitions. This method addresses two important problems: redundancy, where the same concept is represented more than once (described by different terms), and

  9. Satellite power system concept development and evaluation program system definition technical assessment report

    Energy Technology Data Exchange (ETDEWEB)

    1980-12-01

    The results of the system definition studies conducted by NASA as a part of the Department of Energy/National Aeronautics and Space Administration SPS Concept Development and Evaluation Program are summarized. The purpose of the system definition efforts was to identify and define candidate SPS concepts and to evaluate the concepts in terms of technical and cost factors. Although the system definition efforts consisted primarily of evaluation and assessment of alternative technical approaches, a reference system was also defined to facilitate economic, environmental, and societal assessments by the Department of Energy. This reference system was designed to deliver 5 GW of electrical power to the utility grid. Topics covered include system definition; energy conversion and power management; power transmission and reception; structures, controls, and materials; construction and operations; and space transportation.

  10. The MSFC Collaborative Engineering Process for Preliminary Design and Concept Definition Studies

    Science.gov (United States)

    Mulqueen, Jack; Jones, David; Hopkins, Randy

    2011-01-01

    This paper describes a collaborative engineering process developed by the Marshall Space Flight Center's Advanced Concepts Office for performing rapid preliminary design and mission concept definition studies for potential future NASA missions. The process has been developed and demonstrated for a broad range of mission studies including human space exploration missions, space transportation system studies and in-space science missions. The paper will describe the design team structure and specialized analytical tools that have been developed to enable a unique rapid design process. The collaborative engineering process consists of integrated analysis approach for mission definition, vehicle definition and system engineering. The relevance of the collaborative process elements to the standard NASA NPR 7120.1 system engineering process will be demonstrated. The study definition process flow for each study discipline will be will be outlined beginning with the study planning process, followed by definition of ground rules and assumptions, definition of study trades, mission analysis and subsystem analyses leading to a standardized set of mission concept study products. The flexibility of the collaborative engineering design process to accommodate a wide range of study objectives from technology definition and requirements definition to preliminary design studies will be addressed. The paper will also describe the applicability of the collaborative engineering process to include an integrated systems analysis approach for evaluating the functional requirements of evolving system technologies and capabilities needed to meet the needs of future NASA programs.

  11. Diagnostic accuracy of high-definition CT coronary angiography in high-risk patients

    International Nuclear Information System (INIS)

    Iyengar, S.S.; Morgan-Hughes, G.; Ukoumunne, O.; Clayton, B.; Davies, E.J.; Nikolaou, V.; Hyde, C.J.; Shore, A.C.; Roobottom, C.A.

    2016-01-01

    Aim: To assess the diagnostic accuracy of computed tomography coronary angiography (CTCA) using a combination of high-definition CT (HD-CTCA) and high level of reader experience, with invasive coronary angiography (ICA) as the reference standard, in high-risk patients for the investigation of coronary artery disease (CAD). Materials and methods: Three hundred high-risk patients underwent HD-CTCA and ICA. Independent experts evaluated the images for the presence of significant CAD, defined primarily as the presence of moderate (≥50%) stenosis and secondarily as the presence of severe (≥70%) stenosis in at least one coronary segment, in a blinded fashion. HD-CTCA was compared to ICA as the reference standard. Results: No patients were excluded. Two hundred and six patients (69%) had moderate and 178 (59%) had severe stenosis in at least one vessel at ICA. The sensitivity, specificity, positive predictive value, and negative predictive value were 97.1%, 97.9%, 99% and 93.9% for moderate stenosis, and 98.9%, 93.4%, 95.7% and 98.3%, for severe stenosis, on a per-patient basis. Conclusion: The combination of HD-CTCA and experienced readers applied to a high-risk population, results in high diagnostic accuracy comparable to ICA. Modern generation CT systems in experienced hands might be considered for an expanded role. - Highlights: • Diagnostic accuracy of High-Definition CT Angiography (HD-CTCA) has been assessed. • Invasive Coronary angiography (ICA) is the reference standard. • Diagnostic accuracy of HD-CTCA is comparable to ICA. • Diagnostic accuracy is not affected by coronary calcium or stents. • HD-CTCA provides a non-invasive alternative in high-risk patients.

  12. Concept definition of KT-2, a large-aspect-ratio diverter tokamak with FWCD

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Kyoo; Chang, In Soon; Chung, Moon Kyoo; Hwang, Chul Kyoo; Lee, Kwang Won; In, Sang Ryul; Choi, Byung Ho; Hong, Bong Keun; Oh, Byung Hoon; Chung, Seung Ho; Yoon, Byung Joo; Yoon, Jae Sung; Song, Woo Sub [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Chang, Choong Suk; Chang, Hong Yung; Choi, Duk In; Nam, Chang Heui [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of); Chung, Kyoo Sun [Hanyang Univ., Seoul (Korea, Republic of); Hong, Sang Heui [Seoul National Univ., Seoul (Korea, Republic of); Kang, Heui Dong [Kyungpook National Univ., Taegu (Korea, Republic of); Lee, Jae Koo [Pohang Inst. of Science and Technology, Kyungnam (Korea, Republic of)

    1994-11-01

    A concept definition of the KT-2 tokamak is made. The research goal of the machine is to study the `advanced tokamak` physics and engineering issues on the mid size large-aspect-ratio diverter tokamak with intense RF heating (>5 MW). Survey of the status of the research fields, the physics basis for the concept, operation scenarios, as well as machine design concept are presented. (Author) 86 refs., 17 figs., 22 tabs.

  13. Concept definition of KT-2, a large-aspect-ratio diverter tokamak with FWCD

    International Nuclear Information System (INIS)

    Kim, Sung Kyoo; Chang, In Soon; Chung, Moon Kyoo; Hwang, Chul Kyoo; Lee, Kwang Won; In, Sang Ryul; Choi, Byung Ho; Hong, Bong Keun; Oh, Byung Hoon; Chung, Seung Ho; Yoon, Byung Joo; Yoon, Jae Sung; Song, Woo Sub; Chang, Choong Suk; Chang, Hong Yung; Choi, Duk In; Nam, Chang Heui; Chung, Kyoo Sun; Hong, Sang Heui; Kang, Heui Dong; Lee, Jae Koo

    1994-11-01

    A concept definition of the KT-2 tokamak is made. The research goal of the machine is to study the 'advanced tokamak' physics and engineering issues on the mid size large-aspect-ratio diverter tokamak with intense RF heating (>5 MW). Survey of the status of the research fields, the physics basis for the concept, operation scenarios, as well as machine design concept are presented. (Author) 86 refs., 17 figs., 22 tabs

  14. Justifying threshold voltage definition for undoped body transistors through 'crossover point' concept

    International Nuclear Information System (INIS)

    Baruah, Ratul Kumar; Mahapatra, Santanu

    2009-01-01

    Two different definitions, one is potential based and the other is charge based, are used in the literatures to define the threshold voltage of undoped body symmetric double gate transistors. This paper, by introducing a novel concept of crossover point, proves that the charge based definition is more accurate than the potential based definition. It is shown that for a given channel length the potential based definition predicts anomalous change in threshold voltage with body thickness variation while the charge based definition results in monotonous change. The threshold voltage is then extracted from drain current versus gate voltage characteristics using linear extrapolation, transconductance and match-point methods. In all the three cases it is found that trend of threshold voltage variation support the charge based definition.

  15. Classifications, definitions and concepts of locality in Africa.

    Science.gov (United States)

    1983-01-01

    Sub-Saharan Africa, one of the world's least urbanized regions, has within the last 30 years or so been experiencing a very high rate of urban population growth. The prevalence of small localities, invariably spread out over large land surfaces, complicates the classifications and definitions of localities as well as making the identification of settlement patterns in a mapping exercise and during a census or survey field operation difficult. The distinguishing features of a locality are: 1) a distinct (separate) population cluster, 2) inhabitants live in neighboring quarters, and 3) it has a name or a locally recognized status. Even in African countries, where the definition of locality as a distinct population cluster has been employed, problems have cropped up with respect to classifications and identifications. Another problem with the classification of localities is related to the rapid changes that occur in rural settlement patterns. Despite the rapid growth of urban localities within the past few years in sub-Saharan Africa, the proportion of the population living in urban localities is still low. Whereas a locality is a distinct population cluster, with definable boundaries, the village as employed in some countries does not have clear cut boundaries. The definition of a locality as a distinct population cluster in which the inhabitants live in neighboring living quarters and which has a name or a locally recognized status is highly recommended. The UN proposal for the adoption of a classification scheme by size of locality needs to be examined by African countries. The urban/rural dichotomy is recommended for the classification of some tabulations from censuses and surveys--especially on the total population and population of major and minor civil divisions.

  16. Mars power system concept definition study. Volume 2: Appendices

    Science.gov (United States)

    Littman, Franklin D.

    1994-01-01

    This report documents the work performed by Rockwell International's Rocketdyne Division on NASA Contract No. NAS3-25808 (Task Order No. 16) entitled 'Mars Power System Definition Study'. This work was performed for NASA's Lewis Research Center (LeRC). The report is divided into two volumes as follows: Volume 1 - Study Results; and Volume 2 - Appendices. The results of the power system characterization studies, operations studies, and technology evaluations are summarized in Volume 1. The appendices include complete, standalone technology development plans for each candidate power system that was investigated.

  17. Evolution of Mediterranean diets and cuisine: concepts and definitions.

    Science.gov (United States)

    Radd-Vagenas, Sue; Kouris-Blazos, Antigone; Singh, Maria Fiatarone; Flood, Victoria M

    2017-01-01

    The Mediterranean diet has been demonstrated to provide a range of health benefits in observational and clinical trials and adopted by various dietary guidelines. However, a broad range of definitions exist impeding synthesis across trials. This review aims to provide a historical description of Mediterranean diets, from the ancient to the modern, to inform future educational and diet index tool development representing the 'traditional' Mediterranean diet. Nine databases were searched from inception to July 2015 to identify papers defining the Mediterranean diet. The definition accepted by the United Nations Educational, Scientific and Cultural Organization (UNESCO) was also reviewed. The 'traditional' Mediterranean diet is described as high in unprocessed plant foods (grains, vegetables, fruits, legumes, nuts/seeds and extra virgin olive oil), moderate in fish/shellfish and wine and low in meat, dairy, eggs, animal fats and discretionary foods. Additional elements relating to cuisine and eating habits identified in this review include frequent intake of home cooked meals; use of moist, lower temperature, cooking methods; eating main meals in company; reduced snacking occasions; fasting practice; ownership of a vegetable garden; use of traditional foods and combinations; and napping after the midday meal. Scope exists for future tools to incorporate additional elements of the 'traditional' Mediterranean diet to improve the quality, consistency, and synthesis of ongoing research on the Mediterranean diet.

  18. The place of the CT scan in the three concept view (TCV) of the low back syndrome

    International Nuclear Information System (INIS)

    Geldermann, P.W.

    1982-01-01

    From the historical lines along which our thinking about low back pain developed, three concepts can be deduced: radicular, stenotic and axial. The patient with a low back pain syndrome (LBS) should be seen with this three concept view (TCV) in mind. Modern insight into the degenerative process of the low back support this concept. The clinical syndromes illustrating these concepts, radicular syndromes, Neurogenic Peripheral Intermittent Claudication (NPIC), and axial low back pain, can intermingle. To determine the place of the CT scan in the process of diagnosis of the LBS, we carried out a total of 56 CT-examinations on about 200 low back patients with various indications. The results are discussed. In addition to radiological suppositions, NPIC plays an important part in deciding whether or not to perform a CT scan. (Author)

  19. [Alcoholism: definition, diagnosis, illness concept, follow-up, results and costs of treatment].

    Science.gov (United States)

    Feuerlein, W

    1991-02-01

    The article starts with a review on the definition of alcoholism stressing the useful differentiation between alcohol abuse and alcohol dependence. On the basis of this definition the principles of the diagnosis of alcoholism are demonstrated. The disease concept of alcoholism is discussed in detail. Then the aims, the structure and the results of the therapy for alcoholics are briefly described. The article concludes with a short cost-benefit analysis of the alcoholism treatment.

  20. The concept of presence in group psychotherapy: an operational definition.

    Science.gov (United States)

    Crane-Okada, Rebecca

    2012-07-01

    The paper aims to operationally define the concept of presence, as developed and exhibited by the therapist leading a psychotherapy group, and illustrated with case examples. A group therapist, who addresses tangible, basic group survival needs, while integrating knowledge of psychotherapeutic processes, authentic and effective interpersonal communications, and genuine concern for individual members and the group as a whole, is best situated to enact presence in the context of group psychotherapy. Establishing presence can be achieved in a systematic way with an understanding of the meaning of being present at each step in the development of the group psychotherapeutic process. © 2011 Wiley Periodicals, Inc.

  1. Concept definition for space station technology development experiments. Experiment definition, task 2

    Science.gov (United States)

    1986-01-01

    The second task of a study with the overall objective of providing a conceptual definition of the Technology Development Mission Experiments proposed by LaRC on space station is discussed. During this task, the information (goals, objectives, and experiment functional description) assembled on a previous task was translated into the actual experiment definition. Although still of a preliminary nature, aspects such as: environment, sensors, data acquisition, communications, handling, control telemetry requirements, crew activities, etc., were addressed. Sketches, diagrams, block diagrams, and timeline analyses of crew activities are included where appropriate.

  2. The essence of frailty: A systematic review and qualitative synthesis on frailty concepts and definitions.

    Science.gov (United States)

    Junius-Walker, Ulrike; Onder, Graziano; Soleymani, Dagmar; Wiese, Birgitt; Albaina, Olatz; Bernabei, Roberto; Marzetti, Emanuele

    2018-05-31

    One of the major threats looming over the growing older population is frailty. It is a distinctive health state characterised by increased vulnerability to internal and external stressors. Although the presence of frailty is well acknowledged, its concept and operationalisation are hampered by the extraordinary phenotypical and biological complexity. Yet, a widely accepted conception is needed to offer tailored policies and approaches. The ADVANTAGE Group aims to analyse the diverse frailty concepts to uncover the essence of frailty as a basis for a shared understanding. A systematic literature review was performed on frailty concepts and definitions from 2010 onwards. Eligible publications were reviewed using concept analysis that led to the extraction of text data for the themes "definition", "attributes", "antecedents", "consequences", and "related concepts". Qualitative description was used to further analyse the extracted text passages, leading to inductively developed categories on the essence of frailty. 78 publications were included in the review, and 996 relevant text passages were extracted for analysis. Five components constituted a comprehensive definition: vulnerability, genesis, features, characteristics, and adverse outcomes. Each component is described in more detail by a set of defining and explanatory criteria. An underlying functional perspective of health or its impairments is most compatible with the entity of frailty. The recent findings facilitate a focus on the relevant building blocks that define frailty. They point to the commonalities of the diverse frailty concepts and definitions. Based on these components, a widely accepted broad definition of frailty comes into range. Copyright © 2018 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  3. Definition of Turbulent Boundary-Layer with Entropy Concept

    Directory of Open Access Journals (Sweden)

    Zhao Rui

    2016-01-01

    Full Text Available The relationship between the entropy increment and the viscosity dissipation in turbulent boundary-layer is systematically investigated. Through theoretical analysis and direct numerical simulation (DNS, an entropy function fs is proposed to distinguish the turbulent boundary-layer from the external flow. This approach is proved to be reliable after comparing its performance in the following complex flows, namely, low-speed airfoil flows with different wall temperature, supersonic cavity-ramp flow dominated by the combination of free-shear layer, larger recirculation and shocks, and the hypersonic flow past an aeroplane configuration. Moreover, fs is deduced from the point of energy, independent of any particular turbulent quantities. That is, this entropy concept could be utilized by other engineering applications related with turbulent boundary-layer, such as turbulence modelling transition prediction and engineering thermal protection.

  4. Definition and Evaluation of Bus and Truck Automation Operations Concepts: Final Report

    OpenAIRE

    Taso, H. S. Jacob; Botha, Jan L.

    2003-01-01

    Traffic congestion will continue to worsen and likely worsen at a faster rate than ever. People throughput and freight throughput have become critical issues for California and the rest of the nation. PATH has funded a research project entitled Definition And Evaluation of Bus And Truck Automation Operations Concepts, proposed by the authors. This report summarizes the major findings of the research project. During the one-year project, we reviewed literature and developed operating concepts ...

  5. Proton upset rate prediction: a new sensitive volume concept definition

    International Nuclear Information System (INIS)

    Inguimbert, Christophe

    1999-01-01

    We present a model for predicting proton induced single event upset rate. The approach uses heavy ion cross section experimental data combined with nuclear reaction calculations in order to determine the proton upset cross section. The p+Si nuclear reaction as well as the Si(p, p)Si Coulombic scattering are described. The upset rate calculation depends on the energy deposited available in the charge collection region (sensitive region). This region is treated as a rectangular parallelepiped of thickness d at depth h. The sensitive thickness d is used as an input parameter in our model we have developed an original method to probe the sensitive region to evaluate d with reasonable accuracy d. We use short range ions and we propose a new mathematical analysis of these experimental data to determine h and d. This method consists in de-convoluting the heavy ion upset cross section σ_S_E_U(r) by the LET function of the incident ion LET(r) (r is the range of the incident ion). Our results are in relatively good agreement with other models. The accuracy of the method allows us to discuss the validity of the sensitive volume concept. Furthermore, we extrapolate an internal gain factor α that permit to take into account the charge collection mechanisms. α and d serve for quick and reasonably accurate prediction of proton induced SEU cross section in microelectronic devices. (author) [fr

  6. On the definition of a theoretical concept of an operating system

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2010-01-01

    We dwell on how a definition of a theoretical concept of an operating system, suitable to be incorporated in a mathematical theory of operating systems, could look like. This is considered a valuable preparation for the development of a mathematical theory of operating systems.

  7. Towards a Definition of Role-related Concepts for Business Modeling

    NARCIS (Netherlands)

    Meertens, Lucas Onno; Iacob, Maria Eugenia; Nieuwenhuis, Lambertus Johannes Maria

    2010-01-01

    Abstract—While several role-related concepts play an important role in business modeling, their definitions, relations, and use differ greatly between languages, papers, and reports. Due to this, the knowledge captured by models is not transferred correctly, and models are incomparable. In this

  8. Compendium of Executive Summaries from the Maglev System Concept Definition. Final Reports.

    Science.gov (United States)

    1993-03-01

    This report contains the Executive Summaries from the four System Concept Definition (SCD) studies awarded under the National Maglev Initiative...These summaries present the technical feasibility, performance, capital, operating and maintenance costs for a maglev system that would be available by

  9. Posttreatment assessment of response using FDG-PET/CT for patients treated with definitive radiation therapy for head and neck cancers

    International Nuclear Information System (INIS)

    Andrade, Regiane S.; Heron, Dwight E.; Degirmenci, Berna; Filho, Pedro A.A.; Branstetter, Barton F.; Seethala, Raja R.; Ferris, Robert L.; Avril, Norbert

    2006-01-01

    Purpose: The goal of this study was to evaluate coregistered [ 18 F] fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) for the detection of persistent disease after definitive radiation therapy in head and neck cancer. Methods and Materials: Posttreatment FDG-PET/CT was performed in 28 patients on average 8 weeks (range, 4 to 15.7 weeks) after completing definitive radiation therapy. FDG-PET/CT was visually analyzed for the entire patient group and at two time points (4-8 and >8 weeks) after treatment. The contrast-enhanced CT portion of PET/CT was separately analyzed blinded to the results of coregistered FDG-PET/CT and classified as negative or positive for residual locoregional disease. Pathologic findings and clinical follow-up served as the reference standard. Results: Follow-up data were available for all 28 patients (median, 17.6 months). Regarding the detection of residual disease, the overall sensitivity and specificity of FDG-PET/CT was 76.9% and 93.3%, respectively, compared with 92.3% and 46.7% for contrast-enhanced CT. The accuracy of FDG-PET/CT was 85.7%, compared with 67.9% for CT alone. All false-negative (n = 3) and false-positive (n = 1) FDG-PET/CT results occurred between 4 and 8 weeks after treatment. At 8 weeks or later after treatment, the specificity of CT was 28%, compared with 100% for FDG-PET/CT. Conclusions: The metabolic-anatomic information from coregistered FDG-PET/CT provided the most accurate assessment for treatment response when performed later than 8 weeks after the conclusion of radiation therapy. FDG-PET/CT excelled by a higher specificity and overall diagnostic performance than CT imaging alone. These results support a potential clinical role of FDG-PET/CT in the early assessment of therapy response after definitive radiation therapy

  10. Definition of the concept of «social temporality»

    Directory of Open Access Journals (Sweden)

    Yana S. Cherkun

    2016-02-01

    Full Text Available In the article is realized the theoretical analysis of the concepts of «temporality», «social» and «social temporality». Include such attributes of temporality: temporality as an internal time; temporality as a sequence; temporality as temporary; temporality as the length of time a certain point; temporality as a current event. Demarcation with similar concepts and definitions of the semantic aspects of the concept of «social temporality» had conducted. The author notes, that there are many definitions of «temporality», each of which has a right to exist, but the integration of existing social senses to determine temporality as a concept which indicates the rate of turnover in the time of the events that occur in the vital functions of humans in society. It is emphasized that in the presented interpretation of the concept of «social temporality» integrated internalization and exteriorization, and combined the discreteness and integrity. The author analyzes the relationship of the concept of «social temporality» with the concepts «social time», «social space» and «chronotops». The relationship of these concepts is represented by the fact that social time-space trajectory is represented by the flow of events that occur in the social space and move in social time and social temporality stress determines the speed of events. Thus, in the article the connection between the semantic aspects of social temporality and the definition of temporary and spatial specificity of global conflicts had established.

  11. Potential impact of 68Ga-PSMA-11 PET/CT on prostate cancer definitive radiation therapy planning.

    Science.gov (United States)

    Calais, Jérémie; Kishan, Amar U; Cao, Minsong; Fendler, Wolfgang P; Eiber, Matthias; Herrmann, Ken; Ceci, Francesco; Reiter, Robert E; Matthew, Rettig B; Hegde, John V; Shaverdian, Narek; King, Christopher R; Steinberg, Michael L; Czernin, Johannes; Nickols, Nicholas G

    2018-04-13

    Background: Standard-of-care imaging for initial staging of prostate cancer (PCa) underestimates disease burden. Prostate specific membrane antigen (PSMA) positron emission tomography/ computed tomography (PET/CT) detects PCa metastasis with superior accuracy with potential impact definitive radiation therapy (RT) planning for non-metastatic PCa. Objectives: i) To determine how often definitive PCa RT planning based on standard target volumes cover 68 Ga-PSMA-11 PET/CT defined disease, and ii) To assess the potential impact of 68 Ga-PSMA-11 PET/CT on definitive PCa RT planning. Patients and Methods: This is a post-hoc analysis of an intention to treat population of 73 patients with localized PCa without prior local therapy who underwent 68 Ga-PSMA PET/CT for initial staging as part of an Investigational New Drug trial. 11/73 were intermediate-risk (15%), 33/73 were high-risk (45%), 22/73 were very high risk (30%), and 7/73 were N1 (9.5%). Clinical target volumes (CTVs) that included the prostate, seminal vesicles, and pelvic lymph nodes (LNs) using Radiation Therapy Oncology Group (RTOG) consensus guidelines were contoured on the CT portion of the PET/CT by a radiation oncologist blinded to the PET findings. 68 Ga-PSMA-11 PET/CT images were analyzed by a nuclear medicine physician. PSMA-positive lesions not covered by planning volumes based on the CTVs were considered to have a major potential impact on treatment planning. Results: All patients had PSMA-positive primary prostate lesion(s). 25/73 (34%) and 7/73 (9.5%) had PSMA-positive pelvic nodal and distant metastases, respectively. The sites of nodal metastases in decreasing order of frequency were external iliac (20.5%), common iliac (13.5%), internal iliac (12.5%) obturator (12.5%), perirectal (4%), abdominal (4%), upper-diaphragm (4%), and presacral (1.5%). The median size of the nodal lesions was 6 mm (range 4-24 mm). RT planning based on the CTVs covered 69/73 (94.5%) of primary disease and 20/25 (80%) of

  12. Multisource inverse-geometry CT. Part I. System concept and development

    Energy Technology Data Exchange (ETDEWEB)

    De Man, Bruno, E-mail: deman@ge.com; Harrison, Dan; Yin, Zhye [CT Systems and Applications Laboratory, GE Global Research, Niskayuna, New York 12309 (United States); Uribe, Jorge [Functional Imaging Laboratory, GE Global Research, Niskayuna, New York 12309 (United States); Baek, Jongduk [School of Integrated Technology, Yonsei University, Incheon 406-840 (Korea, Republic of); Longtin, Randy; Roy, Jaydeep; Frutschy, Kristopher [Mechanical Systems Technologies, GE Global Research, Niskayuna, New York 12309 (United States); Waters, Bill [Design and Development Shops, GE Global Research, Niskayuna, New York 12309 (United States); Wilson, Colin; Inzinna, Lou; Neculaes, V. Bogdan [High Energy Physics Laboratory, GE Global Research, Niskayuna, New York 12309 (United States); Short, Jonathan [Detector Laboratory, GE Global Research, Niskayuna, New York 12309 (United States); Reynolds, Joseph [High Frequency Power Electronics Laboratory, GE Global Research, Niskayuna, New York 12309 (United States); Senzig, Bob [Molecular Imaging and Computed Tomography, GE Healthcare, Waukesha, Wisconsin 53188 (United States); Pelc, Norbert [Department of Radiology, Stanford University, Stanford, California 94305 (United States)

    2016-08-15

    Purpose: This paper presents an overview of multisource inverse-geometry computed tomography (IGCT) as well as the development of a gantry-based research prototype system. The development of the distributed x-ray source is covered in a companion paper [V. B. Neculaes et al., “Multisource inverse-geometry CT. Part II. X-ray source design and prototype,” Med. Phys. 43, 4617–4627 (2016)]. While progress updates of this development have been presented at conferences and in journal papers, this paper is the first comprehensive overview of the multisource inverse-geometry CT concept and prototype. The authors also provide a review of all previous IGCT related publications. Methods: The authors designed and implemented a gantry-based 32-source IGCT scanner with 22 cm field-of-view, 16 cm z-coverage, 1 s rotation time, 1.09 × 1.024 mm detector cell size, as low as 0.4 × 0.8 mm focal spot size and 80–140 kVp x-ray source voltage. The system is built using commercially available CT components and a custom made distributed x-ray source. The authors developed dedicated controls, calibrations, and reconstruction algorithms and evaluated the system performance using phantoms and small animals. Results: The authors performed IGCT system experiments and demonstrated tube current up to 125 mA with up to 32 focal spots. The authors measured a spatial resolution of 13 lp/cm at 5% cutoff. The scatter-to-primary ratio is estimated 62% for a 32 cm water phantom at 140 kVp. The authors scanned several phantoms and small animals. The initial images have relatively high noise due to the low x-ray flux levels but minimal artifacts. Conclusions: IGCT has unique benefits in terms of dose-efficiency and cone-beam artifacts, but comes with challenges in terms of scattered radiation and x-ray flux limits. To the authors’ knowledge, their prototype is the first gantry-based IGCT scanner. The authors summarized the design and implementation of the scanner and the authors presented

  13. Applied behavior analysis as intervention for autism: definition, features and philosophical concepts

    Directory of Open Access Journals (Sweden)

    Síglia Pimentel Höher Camargo

    2013-11-01

    Full Text Available Autism spectrum disorder (ASD is a lifelong pervasive developmental disorder with no known causes and cure. However, educational and behavioral interventions with a foundation in applied behavior analysis (ABA have been shown to improve a variety of skill areas such as communication, social, academic, and adaptive behaviors of individuals with ASD. The goal of this work is to present the definition, features and philosophical concepts that underlie ABA and make this science an effective intervention method for people with autism.

  14. ECOLOGICAL LIFESTYLE, THE BASIC PRINCIPLES OF THE OPERATIONAL DEFINITION OF THE CONCEPT

    Directory of Open Access Journals (Sweden)

    Olesya Nikolaevna Tarasova

    2015-12-01

    Full Text Available Based on the analysis of approaches to the empirical study of the environmental aspects of lifestyle are presented the basic principles that distinguish ecological way of life off the set of environmental practices that need to be taken into account in empirical measurement, namely: systematicity, conceptuality, contextual conformity and processuality. The article provides a theoretical basis and operational definition as an ecological way of life in general and the principles that distinguish it from other concepts of environmental sociology.

  15. Linking Keystone Species and Functional Groups: A New Operational Definition of the Keystone Species Concept

    OpenAIRE

    Robert D. Davic

    2003-01-01

    The concept of the "keystone species" is redefined to allow for the a priori prediction of these species within ecosystems. A keystone species is held to be a strongly interacting species whose top-down effect on species diversity and competition is large relative to its biomass dominance within a functional group. This operational definition links the community importance of keystone species to a specific ecosystem process, e.g., the regulation of species diversity, within functional groups ...

  16. The relation of CT-determined tumor parameters and local and regional outcome of tonsillar cancer after definitive radiation treatment

    International Nuclear Information System (INIS)

    Hermans, Robert; Op de beeck, Katya; Bogaert, Walter van den; Rijnders, Alexis; Staelens, Lorenzo; Feron, Michel; Bellon, Erwin

    2001-01-01

    Purpose: To investigate the value of CT-derived tumor parameters as predictor of local and regional outcome of tonsillar squamous cell carcinoma treated by definitive radiation therapy. Methods and Materials: The pretreatment CT studies of 112 patients with tonsillar squamous cell carcinoma were reviewed. After redigitizing the films, primary and nodal tumor volume was calculated with the summation-of-areas technique. The nodal CT aspect was graded using a 3-point scale (homogenous, inhomogeneous, and necrotic). Mean follow-up time was 33 months. Actuarial statistical analysis of local and regional outcome was done for each of the covariates; multivariate analysis was performed using Cox's proportional hazards model. Results: In the actuarial analysis, CT-determined primary tumor volume was significantly correlated with local recurrence rate (p<0.05) when all patients were considered, but primary tumor volume did not predict local control within the T2, T3, and T4 category. CT-determined nodal volume was significantly related to regional outcome (p<0.01), but nodal density was not. Total tumor volume was not significantly related to locoregional outcome (p=0.1). In the multivariate analysis, the T and N categories were the independent predictors of local and regional outcomes, respectively. Conclusion: Compared to other head-and-neck sites, primary and nodal tumor volume have only marginal predictive value regarding local and regional outcome after radiation therapy in tonsillar cancer

  17. Evaluation of a dual-room sliding gantry CT concept for workflow optimisation in polytrauma and regular in- and outpatient management

    Energy Technology Data Exchange (ETDEWEB)

    Frellesen, Claudia; Boettcher, Marie; Wichmann, Julian L.; Drieske, Martina; Kerl, J. Matthias; Lehnert, Thomas [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Nau, Christoph; Geiger, Emmanuel; Wutzler, Sebastian [Department of Trauma, Reconstructive and Hand Surgery, Clinic of the Goethe University, Frankfurt (Germany); Ackermann, Hanns [Department of Biostatistics and Mathematical Modelling, Clinic of the Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Vogl, Thomas J. [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Bauer, Ralf W., E-mail: ralfwbauer@aol.com [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany)

    2015-01-15

    Highlights: • A sliding gantry trauma room CT solution facilitates significantly faster polytrauma management. • Faster and more efficient resumption of regularly scheduled patients due to a two room solution is supported. • Sliding gantry CT achieves the same patient throughput as two separate conventional CT devices. - Abstract: Objectives: To reveal the impact on workflow from introducing a dual-room sliding gantry CT to the trauma room for polytrauma and regularly scheduled in- outpatients with regard to efficiency and degree of capacity utilisation. Materials and methods: Time analysis was performed for 30 polytrauma patients each in 2 different trauma room settings, the new trauma room comprising a sliding gantry CT, the old one a stationary single-room CT. Complete trauma room and diagnostic workup times were manually measured and compared for both groups. In a third scenario, the number of CT scans performed with one single sliding gantry CT and the two-room concept was compared to the number of CT scans performed on two separate regular CT units in a 5 days clinical routine sample. Results: Patients demographics and type of CT examinations were comparable for all patient groups. The median time from patient arrival in the trauma room until beginning of CT scanning was 6 min shorter for the sliding gantry CT group (21 vs.15 min). Sliding gantry CT embedded in a two-room solution achieved 252 CT scans in 5 working days, compared to 250 CT scans on two separate regular CT units with the same man power. Conclusions: Sliding gantry CT in the trauma room allows for significant time saving in the diagnostic workup of polytrauma patients and faster resumption of the regular in- outpatient's CT schedule is possible. With the same man power, the dual-room solution is able to generate the same throughput as two separate CT units.

  18. Evaluation of a dual-room sliding gantry CT concept for workflow optimisation in polytrauma and regular in- and outpatient management

    International Nuclear Information System (INIS)

    Frellesen, Claudia; Boettcher, Marie; Wichmann, Julian L.; Drieske, Martina; Kerl, J. Matthias; Lehnert, Thomas; Nau, Christoph; Geiger, Emmanuel; Wutzler, Sebastian; Ackermann, Hanns; Vogl, Thomas J.; Bauer, Ralf W.

    2015-01-01

    Highlights: • A sliding gantry trauma room CT solution facilitates significantly faster polytrauma management. • Faster and more efficient resumption of regularly scheduled patients due to a two room solution is supported. • Sliding gantry CT achieves the same patient throughput as two separate conventional CT devices. - Abstract: Objectives: To reveal the impact on workflow from introducing a dual-room sliding gantry CT to the trauma room for polytrauma and regularly scheduled in- outpatients with regard to efficiency and degree of capacity utilisation. Materials and methods: Time analysis was performed for 30 polytrauma patients each in 2 different trauma room settings, the new trauma room comprising a sliding gantry CT, the old one a stationary single-room CT. Complete trauma room and diagnostic workup times were manually measured and compared for both groups. In a third scenario, the number of CT scans performed with one single sliding gantry CT and the two-room concept was compared to the number of CT scans performed on two separate regular CT units in a 5 days clinical routine sample. Results: Patients demographics and type of CT examinations were comparable for all patient groups. The median time from patient arrival in the trauma room until beginning of CT scanning was 6 min shorter for the sliding gantry CT group (21 vs.15 min). Sliding gantry CT embedded in a two-room solution achieved 252 CT scans in 5 working days, compared to 250 CT scans on two separate regular CT units with the same man power. Conclusions: Sliding gantry CT in the trauma room allows for significant time saving in the diagnostic workup of polytrauma patients and faster resumption of the regular in- outpatient's CT schedule is possible. With the same man power, the dual-room solution is able to generate the same throughput as two separate CT units

  19. An Analysis of Perceptions and Attitudes Toward the Concepts "Disabled" and "Handicapped" and the Effects of Pre-Structured Definition Upon the Concepts.

    Science.gov (United States)

    Ianacone, Robert N.; Stodden, Robert A.

    The semantic differential technique was used in a study involving 40 undergraduate trainees in the area of special education to analyze the concepts "disabled" and "handicapped" and the effects of structured knowledge or definition on the participants' perceptions of and attitudes toward the concepts. The Semantic differential consisted of bipolar…

  20. Definition of internal target volume and domestric study for hepatocellular carcinoma using four-dimensional CT

    International Nuclear Information System (INIS)

    Xi Mian; Liu Mengzhong; Deng Xiaowu; Zhang Li; Huang Xiaoyan; Cai Ling

    2009-01-01

    Objective: To define individualized internal target volume (ITV) for hepatocellular carcinoma using four-dimensional (4D) CT, and to compare the differences in target volume definition and dose distribution among 3D, 4D and respiratory-gated plans. Methods: 4DCT scanning was obtained for 12 patients with hepatocellular. Gross tumor volume (GTV), clinical target volume (CTV) and normal tissues were contoured on all 10 respiratory phases of 4DCT images. The 3D, 4D and gated treatment plans were prepared for each patient using three different planning target volumes (PTVs): 1) PTV 3D was derived from a single CTV plus conventional margins; 2) PTV 4D was derived from ITV 4D , which encompassed all 10 CTVs plus setup margins (SMs); 3) PT Gating was derived from ITV Gating , which encompassed 3 CTVs within gating-window at end-expiration plus SMs. The PTV volume and dose distribution were compared among different plans. Results: The PTV3D was the largest in all 12 patients, but still missed partial target volume in 5 patients when comparing with PTV4D. Both the 4D plans and the gated plans spared more normal tissues than the 3D plans, especially the liver. Without increasing normal tissue dose, the 4D plans allowed for increasing the calculated dose from (50.8 ± 2.0) Gy (3D plans) to (54.7 ± 3.3) Gy, and the gated plans could further increase the dose to (58.0 ± 3.9) Gy. Conclusions: The 4DCT-based plans can ensure optimal target coverage with less irradiation of normal tissues and allow dose escalation when compared with 3D plans. Respiratory gated radiotherapy can further reduce the target volumes to spare more surrounding tissues, especially for patients with large extent of respiratory mobility. (authors)

  1. MO-E-17A-06: Organ Dose in Abdomen-Pelvis CT: Does TG 111 Equilibrium Dose Concept Better Accounts for KVp Dependence Than Conventional CTDI?

    International Nuclear Information System (INIS)

    Li, X; Morgan, A; Davros, W; Dong, F; Primak, A; Segars, W

    2014-01-01

    Purpose: In CT imaging, a desirable quality assurance (QA) dose quantity should account for the dose variability across scan parameters and scanner models. Recently, AAPM TG 111 proposed to use equilibrium dose-pitch product, in place of CT dose index (CTDI100), for scan modes involving table translation. The purpose of this work is to investigate whether this new concept better accounts for the kVp dependence of organ dose than the conventional CTDI concept. Methods: The adult reference female extended cardiac-torso (XCAT) phantom was used for this study. A Monte Carlo program developed and validated for a 128-slice CT system (Definition Flash, Siemens Healthcare) was used to simulate organ dose for abdomenpelvis scans at five tube voltages (70, 80, 100, 120, 140 kVp) with a pitch of 0.8 and a detector configuration of 2x64x0.6 mm. The same Monte Carlo program was used to simulate CTDI100 and equilibrium dose-pitch product. For both metrics, the central and peripheral values were used together with helical pitch to calculate a volume-weighted average, i.e., CTDIvol and (Deq)vol, respectively. Results: While other scan parameters were kept constant, organ dose depended strongly on kVp; the coefficient of variation (COV) across the five kVp values ranged between 70–75% for liver, spleen, stomach, pancreas, kidneys, colon, small intestine, bladder, and ovaries, all of which were inside the primary radiation beam. One-way analysis of variance (ANOVA) for the effect of kVp was highly significant (p=3e−30). When organ dose was normalized by CTDIvol, the COV across the five kVp values reduced to 7–16%. The effect of kVp was still highly significant (p=4e−4). When organ dose was normalized by (Deq)vol, the COV further reduced to 4−12%. The effect of kVp was borderline significant (p=0.04). Conclusion: In abdomen-pelvis CT, TG 111 equilibrium dose concept better accounts for kVp dependence than the conventional CTDI. This work is supported by a faculty startup

  2. MO-E-17A-06: Organ Dose in Abdomen-Pelvis CT: Does TG 111 Equilibrium Dose Concept Better Accounts for KVp Dependence Than Conventional CTDI?

    Energy Technology Data Exchange (ETDEWEB)

    Li, X [Cleveland State University, Cleveland, OH (United States); Morgan, A; Davros, W [Cleveland State University, Cleveland, OH (United States); Cleveland Clinic, Cleveland, Ohio (United States); Dong, F [Cleveland Clinic, Cleveland, Ohio (United States); Primak, A [Siemens Medical Solutions USA, Inc. (United States); Segars, W [Duke University, Durham, NC (United States)

    2014-06-15

    Purpose: In CT imaging, a desirable quality assurance (QA) dose quantity should account for the dose variability across scan parameters and scanner models. Recently, AAPM TG 111 proposed to use equilibrium dose-pitch product, in place of CT dose index (CTDI100), for scan modes involving table translation. The purpose of this work is to investigate whether this new concept better accounts for the kVp dependence of organ dose than the conventional CTDI concept. Methods: The adult reference female extended cardiac-torso (XCAT) phantom was used for this study. A Monte Carlo program developed and validated for a 128-slice CT system (Definition Flash, Siemens Healthcare) was used to simulate organ dose for abdomenpelvis scans at five tube voltages (70, 80, 100, 120, 140 kVp) with a pitch of 0.8 and a detector configuration of 2x64x0.6 mm. The same Monte Carlo program was used to simulate CTDI100 and equilibrium dose-pitch product. For both metrics, the central and peripheral values were used together with helical pitch to calculate a volume-weighted average, i.e., CTDIvol and (Deq)vol, respectively. Results: While other scan parameters were kept constant, organ dose depended strongly on kVp; the coefficient of variation (COV) across the five kVp values ranged between 70–75% for liver, spleen, stomach, pancreas, kidneys, colon, small intestine, bladder, and ovaries, all of which were inside the primary radiation beam. One-way analysis of variance (ANOVA) for the effect of kVp was highly significant (p=3e−30). When organ dose was normalized by CTDIvol, the COV across the five kVp values reduced to 7–16%. The effect of kVp was still highly significant (p=4e−4). When organ dose was normalized by (Deq)vol, the COV further reduced to 4−12%. The effect of kVp was borderline significant (p=0.04). Conclusion: In abdomen-pelvis CT, TG 111 equilibrium dose concept better accounts for kVp dependence than the conventional CTDI. This work is supported by a faculty startup

  3. Definition of postlumpectomy tumor bed for radiotherapy boost field planning: CT versus surgical clips

    International Nuclear Information System (INIS)

    Goldberg, Hadassah; Prosnitz, Robert G.; Olson, John A.; Marks, Lawrence B.

    2005-01-01

    Purpose: To compare the location and extent of the tumor bed as defined by surgical clips and computed tomography (CT) scans, after lumpectomy, for electron boost planning as part of breast radiotherapy. Methods and Materials: Planning CT images of 31 operated breasts in 30 patients who underwent lumpectomy were reviewed. One or more clips were placed in the lumpectomy cavity. Serial CT images were used to measure the depth and transverse and longitudinal dimensions. The area and geometric center of the tumor bed were defined by the clips and CT. Results: The CT and clip measurements were identical for the maximal tumor depth in 27 of 30 patients. The CT bed extended beyond the clips by 0-7 mm medially in the transverse/longitudinal extent (multiclip patients). The median distance between the geometric centers in the coronal plane for the tumor bed center was larger for patients with single clips than for those with multiple clips (p 2 . The CT bed was more readily visible in patients with a shorter interval between surgery and radiotherapy. Conclusion: The maximal depth of the tumor bed was similar using the two methods. The extent and centers of the clip-and CT-determined beds differed significantly. This may indicate an underestimation of the tumor bed as defined by clips only and justifies integration of CT information in boost field planning

  4. Iterative Reconstruction Techniques in Abdominopelvic CT: Technical Concepts and Clinical Implementation.

    Science.gov (United States)

    Patino, Manuel; Fuentes, Jorge M; Singh, Sarabjeet; Hahn, Peter F; Sahani, Dushyant V

    2015-07-01

    This article discusses the clinical challenge of low-radiation-dose examinations, the commonly used approaches for dose optimization, and their effect on image quality. We emphasize practical aspects of the different iterative reconstruction techniques, along with their benefits, pitfalls, and clinical implementation. The widespread use of CT has raised concerns about potential radiation risks, motivating diverse strategies to reduce the radiation dose associated with CT. CT manufacturers have developed alternative reconstruction algorithms intended to improve image quality on dose-optimized CT studies, mainly through noise and artifact reduction. Iterative reconstruction techniques take unique approaches to noise reduction and provide distinct strength levels or settings.

  5. Basic Definitions and Concepts of Systems Approach, Mathematical Modeling and Information Technologies in Sports Science

    Directory of Open Access Journals (Sweden)

    А. Лопатьєв

    2017-09-01

    Full Text Available The objective is to systematize and adapt the basic definitions and concepts of the systems approach, mathematical modeling and information technologies to sports science. Materials and methods. The research has studied the availability of appropriate terms in shooting sports, which would meet the requirements of modern sports science. It has examined the compliance of the shooting sports training program for children and youth sports schools, the Olympic reserve specialized children and youth schools, schools of higher sports skills, and sports educational institutions with the modern requirements and principles. Research results. The paper suggests the basic definitions adapted to the requirements of technical sports and sports science. The research has thoroughly analyzed the shooting sports training program for children and youth sports schools, the Olympic reserve specialized children and youth schools, schools of higher sports skills, and sports educational institutions. The paper offers options to improve the training program in accordance with the modern tendencies of training athletes.  Conclusions. The research suggests to systematize and adapt the basic definitions and concepts of the systems approach, mathematical modeling and information technologies using the example of technical sports.

  6. Definition of the prostate in CT and MRI: a multi-observer study

    NARCIS (Netherlands)

    Rasch, C.; Barillot, I.; Remeijer, P.; Touw, A.; van Herk, M.; Lebesque, J. V.

    1999-01-01

    To determine, in three-dimensions, the difference between prostate delineation in magnetic resonance (MR) and computer tomography (CT) images for radiotherapy treatment planning. Three radiation oncologists, considered experts in the field, outlined the prostate without seminal vesicles both on CT,

  7. Zero-gravity cloud physics laboratory: Candidate experiments definition and preliminary concept studies

    Science.gov (United States)

    Eaton, L. R.; Greco, R. V.; Hollinden, A. B.

    1973-01-01

    The candidate definition studies on the zero-g cloud physics laboratory are covered. This laboratory will be an independent self-contained shuttle sortie payload. Several critical technology areas have been identified and studied to assure proper consideration in terms of engineering requirements for the final design. Areas include chambers, gas and particle generators, environmental controls, motion controls, change controls, observational techniques, and composition controls. This unique laboratory will allow studies to be performed without mechanical, aerodynamics, electrical, or other type techniques to support the object under study. This report also covers the candidate experiment definitions, chambers and experiment classes, laboratory concepts and plans, special supporting studies, early flight opportunities and payload planning data for overall shuttle payload requirements assessments.

  8. The concept and definition of therapeutic inertia in hypertension in primary care: a qualitative systematic review.

    Science.gov (United States)

    Lebeau, Jean-Pierre; Cadwallader, Jean-Sébastien; Aubin-Auger, Isabelle; Mercier, Alain; Pasquet, Thomas; Rusch, Emmanuel; Hendrickx, Kristin; Vermeire, Etienne

    2014-07-02

    Therapeutic inertia has been defined as the failure of health-care provider to initiate or intensify therapy when therapeutic goals are not reached. It is regarded as a major cause of uncontrolled hypertension. The exploration of its causes and the interventions to reduce it are plagued by unclear conceptualizations and hypothesized mechanisms. We therefore systematically searched the literature for definitions and discussions on the concept of therapeutic inertia in hypertension in primary care, to try and form an operational definition. A systematic review of all types of publications related to clinical inertia in hypertension was performed. Medline, EMbase, PsycInfo, the Cochrane library and databases, BDSP, CRD and NGC were searched from the start of their databases to June 2013. Articles were selected independently by two authors on the basis of their conceptual content, without other eligibility criteria or formal quality appraisal. Qualitative data were extracted independently by two teams of authors. Data were analyzed using a constant comparative qualitative method. The final selection included 89 articles. 112 codes were grouped in 4 categories: terms and definitions (semantics), "who" (physician, patient or system), "how and why" (mechanisms and reasons), and "appropriateness". Regarding each of these categories, a number of contradictory assertions were found, most of them relying on little or no empirical data. Overall, the limits of what should be considered as inertia were not clear. A number of authors insisted that what was considered deleterious inertia might in fact be appropriate care, depending on the situation. Our data analysis revealed a major lack of conceptualization of therapeutic inertia in hypertension and important discrepancies regarding its possible causes, mechanisms and outcomes. The concept should be split in two parts: appropriate inaction and inappropriate inertia. The development of consensual and operational definitions

  9. Linking Keystone Species and Functional Groups: A New Operational Definition of the Keystone Species Concept

    Directory of Open Access Journals (Sweden)

    Robert D. Davic

    2003-07-01

    Full Text Available The concept of the "keystone species" is redefined to allow for the a priori prediction of these species within ecosystems. A keystone species is held to be a strongly interacting species whose top-down effect on species diversity and competition is large relative to its biomass dominance within a functional group. This operational definition links the community importance of keystone species to a specific ecosystem process, e.g., the regulation of species diversity, within functional groups at lower trophic levels that are structured by competition for a limited resource. The a priori prediction of keystone species has applied value for the conservation of natural areas.

  10. Feasibility of [18F]FDG-PET and coregistered CT on clinical target volume definition of advanced non-small cell lung cancer

    International Nuclear Information System (INIS)

    Messa, C.; IBFM-CNR, Milan; Scientific Institute H.S. Raffaele, Milan; Ceresoli, G.L.; Gregorc, V.; Rizzo, G.; Scientific Institute H.S. Raffaele, Milan; Artioli, D.; Cattaneo, M.; Castellone, P.; Picchio, M.; Landoni, C.; Scientific Institute H.S. Raffaele, Milan; Fazio, F.; IBFM-CNR, Milan; Scientific Institute H.S. Raffaele, Milan; Scientific Institute H.S. Raffaele, Milan

    2005-01-01

    Aim. To prospectively evaluate the impact of co registered positron emission tomography (PET) and computed tomography (CT) in 3D conformal radiotherapy (3D-CRT) planning in patients with non-small lung cancer (NSCLC). Methods. Twenty-one patients (median age: 57 years; range: 42-80 years) referred to 3D-CRT for NSCLC were recruited. Positron emission tomography with 18 F-fluorodeoxyglucose ([ 18 F]FDG-PET) and conventional CT images were coregistered (PET/CT images) using a commerciaI software package based on surface matching technique. Neoplastic areas were contoured on [ 18 F]FDGPET images with the aid of the correspondent CT image by a nuclear medicine physician. CT images and their relative PET contours were then transferred to treatment planning system. A radiation oncologist firstly contoured clinical target volumes (CTV) on CT scan alone (CTV-CT), and then on co registered PET/CT images (CTV-PET/CT). CTV-CT and CTV-PET/CT were compared for each patient; a difference higher than 25% was considered of clinical relevance. Results. Three patients were shifted to palliative radiotherapy for metastatic disease or very large tumor size, showed by [ 18 F]FDG-PET. Of the remaining 18 patients a CTV change, after inclusion of PET/CT data, was observed in 10/18 cases (55%): larger in 7/18 (range 33-279%) and smaller in 3/18 patients (range 26-34%), mainly due to inclusion or exclusion of Iymph-nodal disease and to better definition of tumor extent. CTV changes smaller than 25% occurred in the remaining 8/18 patients. Conclusion. [ 18 F]FDG-PET and CT images co-registration in radiotherapy treatment planning Ied to a change in CTV definition in the majority of our patients, which may signillcantly modify management and radiation treatment modality in these patients

  11. INFORMATION DIMENSION VS COMMUNICATIVE DIMENSION EXTENDING THE CONCEPT OF DEFINITION AS WILL SWANSON ACTUALLY ALREADY OVERCOME?

    Directory of Open Access Journals (Sweden)

    Dulce María Sánchez-Cadena

    2011-09-01

    Full Text Available Achieve the development of a society entails actions that provide the optimal conditions to be achieved, without exception of sectors (economic, rural, social and coordinating these activities with the capabilities necessary to carry out and achieve the desired development. However, when development strategies are constructed errors of poorly defined concepts for practical and therefore activities focus only on one dimension, when they meet two what happens? We fall short on assigned tasks and consequently the results are not what they expected and planned development does not progress to the estimated speed.In this short letter, we will explore the definition given by extension Swanson reviewed the concepts that compose to discuss briefly information and communication terms of coverage, terms used on a daily basis in the extension activities undertaken in the field Mexican, and we review other positions to see if others Swanson's vision really is outdated or not.

  12. Thoracic cavity definition for 3D PET/CT analysis and visualization.

    Science.gov (United States)

    Cheirsilp, Ronnarit; Bascom, Rebecca; Allen, Thomas W; Higgins, William E

    2015-07-01

    X-ray computed tomography (CT) and positron emission tomography (PET) serve as the standard imaging modalities for lung-cancer management. CT gives anatomical details on diagnostic regions of interest (ROIs), while PET gives highly specific functional information. During the lung-cancer management process, a patient receives a co-registered whole-body PET/CT scan pair and a dedicated high-resolution chest CT scan. With these data, multimodal PET/CT ROI information can be gleaned to facilitate disease management. Effective image segmentation of the thoracic cavity, however, is needed to focus attention on the central chest. We present an automatic method for thoracic cavity segmentation from 3D CT scans. We then demonstrate how the method facilitates 3D ROI localization and visualization in patient multimodal imaging studies. Our segmentation method draws upon digital topological and morphological operations, active-contour analysis, and key organ landmarks. Using a large patient database, the method showed high agreement to ground-truth regions, with a mean coverage=99.2% and leakage=0.52%. Furthermore, it enabled extremely fast computation. For PET/CT lesion analysis, the segmentation method reduced ROI search space by 97.7% for a whole-body scan, or nearly 3 times greater than that achieved by a lung mask. Despite this reduction, we achieved 100% true-positive ROI detection, while also reducing the false-positive (FP) detection rate by >5 times over that achieved with a lung mask. Finally, the method greatly improved PET/CT visualization by eliminating false PET-avid obscurations arising from the heart, bones, and liver. In particular, PET MIP views and fused PET/CT renderings depicted unprecedented clarity of the lesions and neighboring anatomical structures truly relevant to lung-cancer assessment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Current concepts in F18 FDG PET/CT-based Radiation Therapy planning for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Percy eLee

    2012-07-01

    Full Text Available Radiation therapy is an important component of cancer therapy for early stage as well as locally advanced lung cancer. The use of F18 FDG PET/CT has come to the forefront of lung cancer staging and overall treatment decision-making. FDG PET/CT parameters such as standard uptake value and metabolic tumor volume provide important prognostic and predictive information in lung cancer. Importantly, FDG PET/CT for radiation planning has added biological information in defining the gross tumor volume as well as involved nodal disease. For example, accurate target delineation between tumor and atelectasis is facilitated by utilizing PET and CT imaging. Furthermore, there has been meaningful progress in incorporating metabolic information from FDG PET/CT imaging in radiation treatment planning strategies such as radiation dose escalation based on standard uptake value thresholds as well as using respiratory gated PET and CT planning for improved target delineation of moving targets. In addition, PET/CT based follow-up after radiation therapy has provided the possibility of early detection of local as well as distant recurrences after treatment. More research is needed to incorporate other biomarkers such as proliferative and hypoxia biomarkers in PET as well as integrating metabolic information in adaptive, patient-centered, tailored radiation therapy.

  14. A Teacher's Conception of Definition and Use of Examples When Doing and Teaching Mathematics

    Science.gov (United States)

    Johnson, Heather Lynn; Blume, Glendon W.; Shimizu, Jeanne K.; Graysay, Duane; Konnova, Svetlana

    2014-01-01

    To contribute to an understanding of the nature of teachers' mathematical knowledge and its role in teaching, the case study reported in this article investigated a teacher's conception of a metamathematical concept, definition, and her use of examples in doing and teaching mathematics. Using an enactivist perspective on mathematical…

  15. Interleaving cerebral CT perfusion with neck CT angiography. Pt. I. Proof of concept and accuracy of cerebral perfusion values

    Energy Technology Data Exchange (ETDEWEB)

    Oei, Marcel T.H.; Meijer, Frederick J.A.; Woude, Willem-Jan van der; Smit, Ewoud J.; Ginneken, Bram van; Prokop, Mathias; Manniesing, Rashindra [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, P.O. Box 9101, Nijmegen (Netherlands)

    2017-06-15

    We present a novel One-Step-Stroke protocol for wide-detector CT scanners that interleaves cerebral CTP with volumetric neck CTA (vCTA). We evaluate whether the resulting time gap in CTP affects the accuracy of CTP values. Cerebral CTP maps were retrospectively obtained from 20 patients with suspicion of acute ischemic stroke and served as the reference standard. To simulate a 4 s gap for interleaving CTP with vCTA, we eliminated one acquisition at various time points of CTP starting from the bolus-arrival-time(BAT). Optimal timing of the vCTA was evaluated. At the time point with least errors, we evaluated elimination of a second time point (6 s gap). Mean absolute percentage errors of all perfusion values remained below 10 % in all patients when eliminating any one time point in the CTP sequence starting from the BAT. Acquiring the vCTA 2 s after reaching a threshold of 70HU resulted in the lowest errors (mean <3.0 %). Eliminating a second time point still resulted in mean errors <3.5 %. CBF/CBV showed no significant differences in perfusion values except MTT. However, the percentage errors were always below 10 % compared to the original protocol. Interleaving cerebral CTP with neck CTA is feasible with minor effects on the perfusion values. (orig.)

  16. Fire regime: history and definition of a key concept in disturbance ecology.

    Science.gov (United States)

    Krebs, Patrik; Pezzatti, Gianni B; Mazzoleni, Stefano; Talbot, Lee M; Conedera, Marco

    2010-06-01

    "Fire regime" has become, in recent decades, a key concept in many scientific domains. In spite of its wide spread use, the concept still lacks a clear and wide established definition. Many believe that it was first discussed in a famous report on national park management in the United States, and that it may be simply defined as a selection of a few measurable parameters that summarize the fire occurrence patterns in an area. This view has been uncritically perpetuated in the scientific community in the last decades. In this paper we attempt a historical reconstruction of the origin, the evolution and the current meaning of "fire regime" as a concept. Its roots go back to the 19th century in France and to the first half of the 20th century in French African colonies. The "fire regime" concept took time to evolve and pass from French into English usage and thus to the whole scientific community. This coincided with a paradigm shift in the early 1960s in the United States, where a favourable cultural, social and scientific climate led to the natural role of fires as a major disturbance in ecosystem dynamics becoming fully acknowledged. Today the concept of "fire regime" refers to a collection of several fire-related parameters that may be organized, assembled and used in different ways according to the needs of the users. A structure for the most relevant categories of parameters is proposed, aiming to contribute to a unified concept of "fire regime" that can reconcile the physical nature of fire with the socio-ecological context within which it occurs.

  17. Terms, concepts and definitions in clinical artificial nutrition. The ConT-SEEN Project.

    Science.gov (United States)

    Del Olmo García, María Dolores; Ocón Bretón, Julia; Álvarez Hernández, Julia; Ballesteros Pomar, María Dolores; Botella Romero, Francisco; Bretón Lesmes, Irene; de Luis Román, Daniel; Luengo Pérez, Luis Miguel; Martínez Olmos, Miguel Ángel; Olveira Fuster, Gabriel

    2018-01-01

    Imprecision in terms used in the field of clinical nutrition may lead to misinterpretations among professionals. For this reason, the Spanish Society of Endocrinology and Nutrition (SEEN) promoted this document on the terms and definitions used in clinical artificial nutrition (enteral and parenteral), establishing an agreement between Spanish experts of this specialty. Forty-seven specialists in endocrinology and nutrition, members of the Nutrition Area of the SEEN, participated between April and September 2016. After a systematic literature review, 52 concepts were proposed. The coordinators included two additional concepts, and 57were finally selected by the working group: 13 of a general nature, 30 referring to enteral nutrition and 14 to parenteral nutrition. The degree of agreement was subsequently determined using a two-round Delphi process. It was finally ratified by consistency and concordance analysis. Fifty-four of the 57 terms had a very consistent agreement and were concordant. Only three showed no concordance, of whom two were very consistent and one inconsistent. In conclusion, there was consensus in the definition of 54 basic terms in the practice of clinical nutrition. Copyright © 2017 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. [Acute schizophrenia concept and definition: investigation of a French psychiatrist population].

    Science.gov (United States)

    Baylé, F J; Misdrahi, D; Llorca, P M; Lançon, C; Olivier, V; Quintin, P; Azorin, J M

    2005-01-01

    For schizophrenic disorders, the clinical conception of "acute state" is widely used in clinical settings to assess the effectiveness of therapeutic programs as well as epidemiological studies. Schizophrenic-specific symptomatology modification, need for hospitalization, significant change in care, disturbances in social behavior or suicide attempts were all used to define acute schizophrenic state. The decision to hospitalize is frequently used to define acute state but refers to multiple factors such as mood disorder, suicide attempts, drug abuse or social and environmental problems. Indeed, several and distinct definitions in a criteria basis form are available but no one has reached consensus. Because recognition of acute schizophrenic state remains based on the subjective clinician's advice, epidemiological and therapeutic studies fail in validity and reliability. The aim of the study was to evaluate how a population of French psychiatrists define criteria and therapeutic targets of acute schizophrenic state in their clinical practice. Psychiatrists filled out a self administered interview. At the time the interview was given, clinicians were notified that they were participating in a clinical consensus survey about schizophrenia. Six major indicators for acute state definition based on the literature data were proposed: general schizophrenic symptomatology modification (depression, anxiety, agitation, impulsivity/aggressiveness), specific schizophrenic symptomatology modification (positive symptoms, negative symptoms, disorganization), need for hospitalization, significant change in care, disturbance in social behavior and lastly, suicidal behavior. Minimal duration (1.2 or 4 weeks) of general and specific schizophrenic symptomatology modification required to define acute state were evaluated. The booklet included the 30 PANSS symptoms listed with their definitions. Among this symptom list, clinicians were instructed to select the ten criteria which they

  19. Differential-associative processing or example elaboration: Which strategy is best for learning the definitions of related and unrelated concepts?

    Science.gov (United States)

    Hannon, Brenda

    2012-10-01

    Definitions of related concepts (e.g., genotype - phenotype ) are prevalent in introductory classes. Consequently, it is important that educators and students know which strategy(s) work best for learning them. This study showed that a new comparative elaboration strategy, called differential-associative processing, was better for learning definitions of related concepts than was an integrative elaborative strategy, called example elaboration. This outcome occurred even though example elaboration was administered in a naturalistic way (Experiment 1) and students spent more time in the example elaboration condition learning (Experiments 1, 2, 3), and generating pieces of information about the concepts (Experiments 2 and 3). Further, with unrelated concepts ( morpheme-fluid intelligence ), performance was similar regardless if students used differential-associative processing or example elaboration (Experiment 3). Taken as a whole, these results suggest that differential-associative processing is better than example elaboration for learning definitions of related concepts and is as good as example elaboration for learning definitions of unrelated concepts.

  20. 4D-CT-based target volume definition in stereotactic radiotherapy of lung tumours: Comparison with a conventional technique using individual margins

    International Nuclear Information System (INIS)

    Hof, Holger; Rhein, Bernhard; Haering, Peter; Kopp-Schneider, Annette; Debus, Juergen; Herfarth, Klaus

    2009-01-01

    Purpose: To investigate the dosimetric benefit of integration of 4D-CT in the planning target volume (PTV) definition process compared to conventional PTV definition using individual margins in stereotactic body radiotherapy (SBRT) of lung tumours. Material and methods: Two different PTVs were defined: PTV conv consisting of the helical-CT-based clinical target volume (CTV) enlarged isotropically for each spatial direction by the individually measured amount of motion in the 4D-CT, and PTV 4D encompassing the CTVs defined in the 4D-CT phases displaying the extremes of the tumour position. Tumour motion as well as volumetric and dosimetric differences and relations of both PTVs were evaluated. Results: Volumetric examinations revealed a significant reduction of the mean PTV by 4D-CT from 57.7 to 40.7 cm 3 (31%) (p 4D in PTV conv (r = -0.69, 90% confidence limits: -0.87 and -0.34, p = 0.007). Mean lung dose (MLD) was decreased significantly by 17% (p < 0.001). Conclusions: In SBRT of lung tumours the mere use of individual margins for target volume definition cannot compensate for the additional effects that the implementation of 4D-CT phases can offer.

  1. A semantic-based method for extracting concept definitions from scientific publications: evaluation in the autism phenotype domain.

    Science.gov (United States)

    Hassanpour, Saeed; O'Connor, Martin J; Das, Amar K

    2013-08-12

    A variety of informatics approaches have been developed that use information retrieval, NLP and text-mining techniques to identify biomedical concepts and relations within scientific publications or their sentences. These approaches have not typically addressed the challenge of extracting more complex knowledge such as biomedical definitions. In our efforts to facilitate knowledge acquisition of rule-based definitions of autism phenotypes, we have developed a novel semantic-based text-mining approach that can automatically identify such definitions within text. Using an existing knowledge base of 156 autism phenotype definitions and an annotated corpus of 26 source articles containing such definitions, we evaluated and compared the average rank of correctly identified rule definition or corresponding rule template using both our semantic-based approach and a standard term-based approach. We examined three separate scenarios: (1) the snippet of text contained a definition already in the knowledge base; (2) the snippet contained an alternative definition for a concept in the knowledge base; and (3) the snippet contained a definition not in the knowledge base. Our semantic-based approach had a higher average rank than the term-based approach for each of the three scenarios (scenario 1: 3.8 vs. 5.0; scenario 2: 2.8 vs. 4.9; and scenario 3: 4.5 vs. 6.2), with each comparison significant at the p-value of 0.05 using the Wilcoxon signed-rank test. Our work shows that leveraging existing domain knowledge in the information extraction of biomedical definitions significantly improves the correct identification of such knowledge within sentences. Our method can thus help researchers rapidly acquire knowledge about biomedical definitions that are specified and evolving within an ever-growing corpus of scientific publications.

  2. A semantic-based method for extracting concept definitions from scientific publications: evaluation in the autism phenotype domain

    OpenAIRE

    Hassanpour, Saeed; O?Connor, Martin J; Das, Amar K

    2013-01-01

    Background A variety of informatics approaches have been developed that use information retrieval, NLP and text-mining techniques to identify biomedical concepts and relations within scientific publications or their sentences. These approaches have not typically addressed the challenge of extracting more complex knowledge such as biomedical definitions. In our efforts to facilitate knowledge acquisition of rule-based definitions of autism phenotypes, we have developed a novel semantic-based t...

  3. Organic food processing: a framework for concept, starting definitions and evaluation.

    Science.gov (United States)

    Kahl, Johannes; Alborzi, Farnaz; Beck, Alexander; Bügel, Susanne; Busscher, Nicolaas; Geier, Uwe; Matt, Darja; Meischner, Tabea; Paoletti, Flavio; Pehme, Sirli; Ploeger, Angelika; Rembiałkowska, Ewa; Schmid, Otto; Strassner, Carola; Taupier-Letage, Bruno; Załęcka, Aneta

    2014-10-01

    In 2007 EU Regulation (EC) 834/2007 introduced principles and criteria for organic food processing. These regulations have been analysed and discussed in several scientific publications and research project reports. Recently, organic food quality was described by principles, aspects and criteria. These principles from organic agriculture were verified and adapted for organic food processing. Different levels for evaluation were suggested. In another document, underlying paradigms and consumer perception of organic food were reviewed against functional food, resulting in identifying integral product identity as the underlying paradigm and a holistic quality view connected to naturalness as consumers' perception of organic food quality. In a European study, the quality concept was applied to the organic food chain, resulting in a problem, namely that clear principles and related criteria were missing to evaluate processing methods. Therefore the goal of this paper is to describe and discuss the topic of organic food processing to make it operational. A conceptual background for organic food processing is given by verifying the underlying paradigms and principles of organic farming and organic food as well as on organic processing. The proposed definition connects organic processing to related systems such as minimal, sustainable and careful, gentle processing, and describes clear principles and related criteria. Based on food examples, such as milk with different heat treatments, the concept and definitions were verified. Organic processing can be defined by clear paradigms and principles and evaluated according criteria from a multidimensional approach. Further work has to be done on developing indicators and parameters for assessment of organic food quality. © 2013 Society of Chemical Industry.

  4. Organic food quality: a framework for concept, definition and evaluation from the European perspective.

    Science.gov (United States)

    Kahl, Johannes; Baars, Ton; Bügel, Susanne; Busscher, Nicolaas; Huber, Machteld; Kusche, Daniel; Rembiałkowska, Ewa; Schmid, Otto; Seidel, Kathrin; Taupier-Letage, Bruno; Velimirov, Alberta; Załecka, Aneta

    2012-11-01

    Consumers buy organic food because they believe in the high quality of the product. Furthermore, the EU legal regulatory framework for organic food and farming defines high quality of the products as an important goal of production. A major challenge is the need to define food quality concepts and methods for determination. A background is described which allows embedding of the quality definitions as well as evaluation methods into a conceptual framework connected to the vision and mission of organic agriculture and food production. Organic food quality is defined through specific aspects and criteria. For evaluation each criterion has to be described by indicators. The determination of indicators should be through parameters, where parameters are described by methods. Conversely, the conceptual framework is described according to underlying principles and starting definitions are given, but further work has do be done on the detailed scientific description of the indicators. Furthermore, parameters have to be defined for the evaluation of suitability of these indicators for organic food production. Copyright © 2012 Society of Chemical Industry.

  5. PROGNOSTICAL COMPETENCE OF THE FUTURE TEACHERS-ACTORS: TO THE ISSUE OF THE CONCEPT DEFINITION

    Directory of Open Access Journals (Sweden)

    Elena Viktorovna Tsalko

    2016-02-01

    Full Text Available In this paper on the basis of the notions of competence, forecasting, prognostical competence the author’s definition of future actors-teachers’ prognostical competence is developed. Under prognostic competence of future actors-teachers we understand a special competence that allows the subject, engaged in professional activities as a performer of roles in the theater (movies, TV, as well as performing teaching activities in the field of arts, to receive the necessary anticipatory information about the phenomenon under investigation (on performing roles in the theatre, films, and television, on the learning process and actors-teachers training. Components of prognostical competence as a type of competencies (cognitive, instrumental and operational and motivational-value are singled out. The feature of the future actor-teacher’s professional activities in the context of prognostical competence is viewed. It is the simultaneous solving the artistic-creative, organizational and teaching-upbringing problems.Purpose. The purpose of the paper is the definition of prognostical competence of future teachers-actors.Methodology. In the research the methods of theoretical level are used: comparison, analysis and synthesis, generalization, concretization; analytical methods; idealization and modeling.Result. The result of the research is the development of the author’s concept of «prognostical competence of the future teachers-actors».Practical implications. Application of the results: The results may be applied to the work of teachers-actors’ trainers as well as the researchers in Pedagogy.

  6. Concept and development status of fast breeder reactor fuels in the FaCT project

    International Nuclear Information System (INIS)

    Maeda, S.; Suzuki, M.; Kaito, T.; Tanaka, K.; Abe, T.

    2013-01-01

    The fuel development and the conceptual design study have been progressed in the first phase of the FaCT project in Japan. Significant outcomes of key technologies related to fuel design, fuel properties, core materials, fuel fabrication have been provided. The prospects of these technologies have been identified. After the Fukushima accident, the research and development for reducing the amount and toxic level of radioactive wastes will be promoted more than before. These outcomes will be reflected on the future development

  7. The significance of a uniform definition of pathological lymph nodes in Hodgkin lymphoma: Impact of different thresholds for positive lymph nodes in CT imaging on staging and therapy

    International Nuclear Information System (INIS)

    Vorwerk, Hilke; Obenauer, Silvia; Schmidberger, Heinz; Hess, Clemens F.; Weiss, Elisabeth

    2008-01-01

    Background and Purpose: The most commonly used approach for the assessment for differentiating malignant versus reactive lymph nodes is the measurement of the cross-section diameter of the lymph nodes in the transversal CT-planes. The intention of this article is to assess the impact of varying definitions of pathological lymph node size in CT-imaging in patients with Hodgkin lymphoma and to evaluate its effect on staging, chemotherapy regimes and radiation field size. Materials and methods: Pretherapeutic CT-scans of 10 consecutive patients with Hodgkin lymphoma have been evaluated based on two different definitions for malignant lymph node size; the classification of the German study group for Hodgkin lymphoma (1.0 cm) and the classification according to the results of the Cotswold consensus meeting 1989 (1.5 cm). Results: Applying the definitions of the DHSG and the Cotswold meeting we found more affected lymph node regions compared to the evaluation of the referring institutions in 9/10 and 6/10 patients, higher stages in 2/10 and 1/10 patients, more intense chemotherapy regimes in 3/10 and 1/10 and larger radiation fields in 10/10 and 6/10 patients, respectively. Conclusions: Varying definitions of pathologic lymph node size and inconsequent application of definitions reduce the comparability between different studies and within each study

  8. 68Ga-PSMA PET/CT in Patients with Rising Prostatic-Specific Antigen After Definitive Treatment of Prostate Cancer: Detection Efficacy and Diagnostic accuracy.

    Science.gov (United States)

    Hamed, Maged Abdel Galil; Basha, Mohammad Abd Alkhalik; Ahmed, Hussien; Obaya, Ahmed Ali; Afifi, Amira Hamed Mohamed; Abdelbary, Eman H

    2018-06-20

    68 Ga-prostate-specific membrane antigen-11 ( 68 Ga-PSMA-11) is a recently developed positron emission tomography (PET) tracer that can detect prostate cancer (PC) relapses and metastases with high contrast resolution. The aim of this study was to assess the detection efficacy and diagnostic accuracy of 68 Ga-PSMA PET/CT image in patients with rising prostatic-specific antigen (PSA) after treatment of PC. The present prospective study included 188 patients who exhibited rising of PSA level on a routine follow-up examination after definitive treatment of PC. All patients underwent a 68 Ga-PSMA PET/CT examination. For each patient, we determined the disease stage, the Gleason score, and the maximum standardized uptake value of the local recurrence and extraprostatic metastases. The detection efficacy and diagnostic accuracy of 68 Ga-PSMA PET/CT were established by histopathology and clinical and imaging follow-up as the reference standards. 68 Ga-PSMA PET/CT detected tumour relapse in 165 patients (35 patients had local recurrence, 106 patients had extraprostatic metastases, and 24 patients had combined lesions). The sensitivity, specificity, and accuracy values of 68 Ga-PSMA PET/CT examination in the detection of PC recurrence were 98.8%, 100%, and 98.8%, respectively. 68 Ga-PSMA PET/CT revealed an overall detection rate of 87.8% (165/188) in patients with rising PSA (median of 2.2 ng/mL, and range of 0.01-70 ng/mL). 68 Ga-PSMA PET/CT is a valuable tool for the detection of PC local recurrence or extraprostatic metastases following rising PSA levels after primary definitive therapy and should be incorporated during routine work-up. Copyright © 2018. Published by Elsevier Inc.

  9. System concept definition of the Grumman superconducting Electromagnetic Suspension (EMS) Maglev design

    Science.gov (United States)

    Proise, M.

    1994-01-01

    Grumman, under contract to the Army Corps of Engineers, completed a System Concept Definition (SCD) study to design a high-speed 134 m/s (300 m.p.h.) magnetically levitated (Maglev) transportation system. The primary development goals were to design a Maglev that is safe, reliable, environmentally acceptable, and low-cost. The cost issue was a predominant one, since previous studies have shown that an economically viable Maglev system (one that is attractive to investors for future models of passenger and/or freight transportation) requires a cost that is about $12.4 M/km ($20 Million per mile). The design is based on the electromagnetic suspension (EMS) system using superconducting iron-core magnets mounted along both sides of the vehicle. The EMS system has several advantages compared to the electrodynamic suspension (EDS) Maglev systems such as low stray magnetic fields in the passenger cabin and the surrounding areas, uniform load distribution along the full length of the vehicle, and small pole pitch for smoother propulsion and ride comfort. It is also levitated at all speeds and incorporates a wrap-around design of safer operation. The Grumman design has all the advantages of an EMS system identified above, while eliminating (or significantly improving) drawbacks associated with normal magnet powered EMS systems. Improvements include larger gap clearance, lighter weight, lower number of control servos, and higher off line switching speeds. The design also incorporates vehicle tilt (plus or minus 9 deg) for higher coordinated turn and turn out speed capability.

  10. Large Deployable Reflector (LDR) system concept and technology definition study. Volume 1: Executive summary, analyses and trades, and system concepts

    Science.gov (United States)

    Agnew, Donald L.; Jones, Peter A.

    1989-01-01

    A study was conducted to define reasonable and representative large deployable reflector (LDR) system concepts for the purpose of defining a technology development program aimed at providing the requisite technological capability necessary to start LDR development by the end of 1991. This volume includes the executive summary for the total study, a report of thirteen system analysis and trades tasks (optical configuration, aperture size, reflector material, segmented mirror, optical subsystem, thermal, pointing and control, transportation to orbit, structures, contamination control, orbital parameters, orbital environment, and spacecraft functions), and descriptions of three selected LDR system concepts. Supporting information is contained in appendices.

  11. Measuring social science concepts in pharmacy education research: From definition to item analysis of self-report instruments.

    Science.gov (United States)

    Cor, M Ken

    Interpreting results from quantitative research can be difficult when measures of concepts are constructed poorly, something that can limit measurement validity. Social science steps for defining concepts, guidelines for limiting construct-irrelevant variance when writing self-report questions, and techniques for conducting basic item analysis are reviewed to inform the design of instruments to measure social science concepts in pharmacy education research. Based on a review of the literature, four main recommendations emerge: These include: (1) employ a systematic process of conceptualization to derive nominal definitions; (2) write exact and detailed operational definitions for each concept, (3) when creating self-report questionnaires, write statements and select scales to avoid introducing construct-irrelevant variance (CIV); and (4) use basic item analysis results to inform instrument revision. Employing recommendations that emerge from this review will strengthen arguments to support measurement validity which in turn will support the defensibility of study finding interpretations. An example from pharmacy education research is used to contextualize the concepts introduced. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Space platform expendables resupply concept definition study. Volume 3: Work breakdown structure and work breakdown structure dictionary

    Science.gov (United States)

    1984-01-01

    The work breakdown structure (WBS) for the Space Platform Expendables Resupply Concept Definition Study is described. The WBS consists of a list of WBS elements, a dictionary of element definitions, and an element logic diagram. The list and logic diagram identify the interrelationships of the elements. The dictionary defines the types of work that may be represented by or be classified under each specific element. The Space Platform Expendable Resupply WBS was selected mainly to support the program planning, scheduling, and costing performed in the programmatics task (task 3). The WBS is neither a statement-of-work nor a work authorization document. Rather, it is a framework around which to define requirements, plan effort, assign responsibilities, allocate and control resources, and report progress, expenditures, technical performance, and schedule performance. The WBS element definitions are independent of make-or-buy decisions, organizational structure, and activity locations unless exceptions are specifically stated.

  13. Are Alternative Conceptions Dependent on Researchers' Methodology and Definition?: A Review of Empirical Studies Related to Concepts of Heat

    Science.gov (United States)

    Wong, Chee Leong; Chu, Hye-Eun; Yap, Kueh Chin

    2016-01-01

    Currently, there is no agreement among scientists and science educators on whether heat should be defined as a "process of energy transfer" or "form of energy." For example, students may conceive of heat as "molecular kinetic energy," but the interpretation of this alternative conception is dependent on educational…

  14. Satellite Power Systems (SPS) concept definition study (Exhibit D). Volume 5: Systems engineering/integration research and technology

    Science.gov (United States)

    Hanley, G. M.

    1981-01-01

    Guidelines and ground rules followed in the development of requirements for the SPS are presented. Development planning objectives are specified in each of these areas, and evolutionary SPS program scenarios are described for the various concepts studied during the past one year contract. Program descriptions are presented as planning packages of technical tasks, and schedule phasing. Each package identifies the ground based technology effort that will facilitate SPS definitions, designs, development, and operations.

  15. Converting from CT- to MRI-only-based target definition in radiotherapy of localized prostate cancer: A comparison between two modalities.

    Science.gov (United States)

    Seppälä, Tiina; Visapää, Harri; Collan, Juhani; Kapanen, Mika; Beule, Annette; Kouri, Mauri; Tenhunen, Mikko; Saarilahti, Kauko

    2015-11-01

    To investigate the conversion of prostate cancer radiotherapy (RT) target definition from CT-based planning into an MRI-only-based planning procedure. Using the CT- and MRI-only-based RT planning protocols, 30 prostate cancer patients were imaged in the RT fixation position. Two physicians delineated the prostate in both CT and T2-weighted MRI images. The CT and MRI images were coregistered based on gold seeds and anatomic borders of the prostate. The uncertainty of the coregistration, as well as differences in target volumes and uncertainty of contour delineation were investigated. Conversion of margins and dose constraints from CT- to MRI-only-based treatment planning was assessed. On average, the uncertainty of image coregistration was 0.4 ± 0.5 mm (one standard deviation, SD), 0.9 ± 0.8 mm and 0.9 ± 0.9 mm in the lateral, anterior-posterior and base-apex direction, respectively. The average ratio of the prostate volume between CT and MRI was 1.20 ± 0.15 (one SD). Compared to the CT-based contours, the MRI-based contours were on average 2-7 mm smaller in the apex, 0-1 mm smaller in the rectal direction and 1-4 mm smaller elsewhere. When converting from a CT-based planning procedure to an MRI-based one, the overall planning target volumes (PTV) are prominently reduced only in the apex. The prostate margins and dose constraints can be retained by this conversion.

  16. Converting from CT- to MRI-only-based target definition in radiotherapy of localized prostate cancer. A comparison between two modalities

    Energy Technology Data Exchange (ETDEWEB)

    Seppaelae, Tiina; Visapaeae, Harri; Collan, Juhani; Kapanen, Mika; Kouri, Mauri; Tenhunen, Mikko; Saarilahti, Kauko [University of Helsinki and Helsinki University Hospital, Comprehensive Cancer Center, POB 180, Helsinki (Finland); Beule, Annette [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 180, Helsinki (Finland)

    2015-11-15

    To investigate the conversion of prostate cancer radiotherapy (RT) target definition from CT-based planning into an MRI-only-based planning procedure. Using the CT- and MRI-only-based RT planning protocols, 30 prostate cancer patients were imaged in the RT fixation position. Two physicians delineated the prostate in both CT and T2-weighted MRI images. The CT and MRI images were coregistered based on gold seeds and anatomic borders of the prostate. The uncertainty of the coregistration, as well as differences in target volumes and uncertainty of contour delineation were investigated. Conversion of margins and dose constraints from CT- to MRI-only-based treatment planning was assessed. On average, the uncertainty of image coregistration was 0.4 ± 0.5 mm (one standard deviation, SD), 0.9 ± 0.8 mm and 0.9 ± 0.9 mm in the lateral, anterior-posterior and base-apex direction, respectively. The average ratio of the prostate volume between CT and MRI was 1.20 ± 0.15 (one SD). Compared to the CT-based contours, the MRI-based contours were on average 2-7 mm smaller in the apex, 0-1 mm smaller in the rectal direction and 1-4 mm smaller elsewhere. When converting from a CT-based planning procedure to an MRI-based one, the overall planning target volumes (PTV) are prominently reduced only in the apex. The prostate margins and dose constraints can be retained by this conversion. (orig.) [German] Ziel unserer Studie war es, die Umstellung der Strahlentherapieplanung des Prostatakarzinoms von CT-gestuetzter in ausschliesslich MR-gestuetzte Zieldefinition zu untersuchen. Bei 30 Patienten mit Prostatakarzinom wurden eine CT und eine MRT unter Planungsbedingungen durchgefuehrt. Zwei Untersucher konturierten die Prostata in CT- und T2-gewichteten MR-Bildern. Mit Hilfe der Position von Goldstiften und der anatomischen Grenzen der Prostata wurden die CT- und MR-Bilder koregistriert. Es wurden die Genauigkeit der Koregistrierung sowie die Unterschiede der Zielvolumina und der

  17. A Contribution to the Definition of the Concept of Popular Culture: An Empirical Inquiry into the Epistemological Shortcomings of Popular Conceptions about Pretrial Detention in Serbia

    Directory of Open Access Journals (Sweden)

    Saša Nedeljković

    2016-02-01

    Full Text Available In an attempt to ascertain the functionality of certain definitions of the concept of popular culture, or rather, to point out certain methodological options for the study of popular culture through analyzing certain popular conceptions, I have sought out those areas of social life which are under-represented in popular culture. I consider their avoidance symptomatic, worthy of attention and suitable for analysis. Discovering pretrial confinement as one such neglected area or topic, and trying to indirectly discover what might be the cause of this, I have analyzed and systematized those of its characteristics and elements which do not fulfill the requirements of the syndrome of popularity as it is typically understood.

  18. [Concept, definition and classification of intra-abdominal hypertension in pregnancy].

    Science.gov (United States)

    Marshalov, D V; Salov, I A; Shifman, E M; Petrenko, A P

    2013-01-01

    The article stresses methodological aspects of intaabdominal hypertension at pregnancy. Formal-logical analysis of conceptual framework and available classifications of intaabdominal hypertension was carried out. The article presents new definition and classification of intaabdominal hypertension.

  19. Equivalence of the Traditional and Non-Standard Definitions of Concepts from Real Analysis

    Directory of Open Access Journals (Sweden)

    John Cowles

    2014-06-01

    Full Text Available ACL2(r is a variant of ACL2 that supports the irrational real and complex numbers. Its logical foundation is based on internal set theory (IST, an axiomatic formalization of non-standard analysis (NSA. Familiar ideas from analysis, such as continuity, differentiability, and integrability, are defined quite differently in NSA–some would argue the NSA definitions are more intuitive. In previous work, we have adopted the NSA definitions in ACL2(r, and simply taken as granted that these are equivalent to the traditional analysis notions, e.g., to the familiar epsilon-delta definitions. However, we argue in this paper that there are circumstances when the more traditional definitions are advantageous in the setting of ACL2(r, precisely because the traditional notions are classical, so they are unencumbered by IST limitations on inference rules such as induction or the use of pseudo-lambda terms in functional instantiation. To address this concern, we describe a formal proof in ACL2(r of the equivalence of the traditional and non-standards definitions of these notions.

  20. The Impact of an Operational Definition of the Weight Concept on Students' Understanding

    Science.gov (United States)

    Stein, Hana; Galili, Igal

    2015-01-01

    Several researches in physics education have demonstrated the problematic status of teaching the subject of gravitation and weight and students' knowledge of these concepts. This paper presents findings of a study of students' knowledge following instruction within a changed conceptual framework of the weight concept in several 9th grade classes…

  1. Business communication and globalized English: recent definitions and applications of a concept across the corporate world

    Directory of Open Access Journals (Sweden)

    Fee-Alexandra HAASE

    2014-10-01

    Full Text Available This article approaches ‘business communication’ as a multi-layered economic phenomenon of the corporate society of the globalized business world. In academic education systems and in the business world under the term ‘business communication’ various definitions exist, which are applied across the fields of academic studies and in the business world. After the comparison of definitions of ‘business communication’, we demonstrate the various layers of business communication in the contemporary corporate world based upon a model of the corporate world and these cases using examples of companies implementing ‘business communication’ into their corporate structure.

  2. Post-treatment PET/CT and p16 status for predicting treatment outcomes in locally advanced head and neck cancer after definitive radiation

    Energy Technology Data Exchange (ETDEWEB)

    Awan, Musaddiq J.; Machtay, Mitchell; Yao, Min [Case Western Reserve University and University Hospitals, Department of Radiation Oncology, Cleveland, OH (United States); Lavertu, Pierre; Zender, Chad; Rezaee, Rod; Fowler, Nicole [University Hospitals, Department of Otolaryngology and Head and Neck Surgery, Cleveland, OH (United States); Karapetyan, Lilit; Gibson, Michael [University Hospitals, Department of Medical Oncology, Cleveland, OH (United States); Wasman, Jay [University Hospitals, Department of Pathology, Cleveland, OH (United States); Faulhaber, Peter [University Hospitals, Department of Nuclear Medicine and Radiology, Cleveland, OH (United States)

    2017-06-15

    To retrospectively review post-treatment (post-tx) FDG-PET/CT scans in patients with advanced head and neck squamous cell carcinoma (HNSCC) and known p16 status, treated with definitive (chemo)radiation (RT). A total of 108 eligible patients had N2A or greater HNSCC treated with chemoRT from August 1, 2008, to February 28, 2015, with post-tx PET/CT within 6 months after RT. Kaplan-Meier curves, log-rank statistics, and Cox proportional hazards regression were used for statistical analysis. Median follow-up was 2.38 years. Sixty-eight (63.0%) patients had p16+ and 40 (37.0%) had p16- status. Two-year overall survival and recurrence-free survival were 93.4% and 77.8%, respectively. The negative predictive value (NPV) of PET/CT for local recurrence (LR) was 100%. The NPV for regional recurrence (RR) was 96.5% for all patients, 100% for p16+ patients, and 88.5% for p16- patients. The positive predictive value (PPV) of PET/CT for recurrence was 77.3% for all patients, 50.0% for p16+, and 78.6% for p16-. The PPV for LR was 72.7% for all patients, 50.0% for p16+ patients, and 72.7% for p16- patients. The PPV for RR was 50.0% for all patients, 33% for p16+, and 66.6% for p16-. Post-tx PET/CT and p16 status were independent predictors of recurrence-free survival (p < 0.01). Post-tx PET/CT predicts treatment outcomes in both p16 + and p16- patients, and does so independently of p16 status. P16- patients with negative PET have a 10% risk of nodal recurrence, and closer follow-up in these patients is warranted. (orig.)

  3. Children's Scientific Curiosity: In Search of an Operational Definition of an Elusive Concept

    Science.gov (United States)

    Jirout, Jamie; Klahr, David

    2012-01-01

    Although curiosity is an undeniably important aspect of children's cognitive development, a universally accepted operational definition of children's curiosity does not exist. Almost all of the research on measuring curiosity has focused on adults, and has used predominately questionnaire-type measures that are not appropriate for young children.…

  4. Transactional Infrastructure of the Economy: the Evolution of Concepts and Synthesis of Definitions

    OpenAIRE

    Maruschak Irina Valeryevna

    2017-01-01

    The overview of evolution of market infrastructure concepts is provided, the first concepts of institutional infrastructure are revealed in the paper. Evolutionarily developed narrowing of essence of infrastructure in connection with the priority analysis of its physical (material and technological) components is proved. It ignores the fact that transactional resources, being drivers (driving forces) of economic systems evolution, in turn evolve, becoming harder and harder, combining increase...

  5. Satellite power systems (SPS) concept definition study. Volume 2, part 1: System engineering

    Science.gov (United States)

    Hanley, G. M.

    1980-01-01

    Top level trade studies are presented, including comparison of solid state and klystron concepts, higher concentration on the solar cells, composite and aluminum structure, and several variations to the reference concept. Detailed trade studies are presented in each of the subsystem areas (solar array, power distribution, structures, thermal control, attitude control and stationkeeping, microwave transmission, and ground receiving station). A description of the selected point design is also presented.

  6. Distribution of lymph node metastases on FDG-PET/CT in inoperable or unresectable oesophageal cancer patients and the impact on target volume definition in radiation therapy

    International Nuclear Information System (INIS)

    Machiels, Melanie; Geijsen, Elisabeth D.; Van Os, Rob M.; Hulshof, Maarten CCM; Wouterse, Sanne J.; Bennink, Roel J.; Van Laarhoven, Hanneke WM.

    2016-01-01

    Definitive chemoradiotherapy (dCRT) is standard care for localised inoperable/unresectable oesophageal tumours. Many surgical series have reported on distribution of lymph node metastases (LNM) in resected patients. However, no data is available on the distribution of at-risk LN regions in this more unfavourable patient group. This study aimed to determine the spread of LNM using FDG-PET/CT, to compare it with the distribution in surgical series and to define its impact on the definition of elective LN irradiation (ENI). FDG-PET/CT images of patients with oesophageal cancer treated with dCRT (from 2003 to 2013) were reviewed to identify the anatomic distribution of FDG-avid LNs. Tumours were divided according to proximal, mid-thoracic or distal localisation. About 105 consecutive patients entered analysis. The highest numbers of FDG-avid LNs in proximal tumours were at LN station 101R (45%) and 106recL (35%). For mid-thoracic tumours at 104R (30%) and 105 (30%). For tumours located in the distal oesophagus, the most common sites were along the lesser curvature of the stomach (21%) and the left gastric artery (21%). Except for the supraclavicular and pretracheal nodes, there were no positive locoregional LNM found outside the standard surgical resection area. Our results show a good correlation between the distribution of nodal volumes at risk in surgical series and on FDG-PET/CT. The results can be used to determine target definition in dCRT for oesophageal cancer. For mid-thoracic tumours, the current target delineation guidelines may be extended based on the risk of node involvement, but more clinical studies are needed to determine if the potential harm of expanding the CTV outweighs the potential benefit.

  7. Distribution of lymph node metastases on FDG-PET/CT in inoperable or unresectable oesophageal cancer patients and the impact on target volume definition in radiation therapy.

    Science.gov (United States)

    Machiels, Melanie; Wouterse, Sanne J; Geijsen, Elisabeth D; van Os, Rob M; Bennink, Roel J; van Laarhoven, Hanneke Wm; Hulshof, Maarten Ccm

    2016-08-01

    Definitive chemoradiotherapy (dCRT) is standard care for localised inoperable/unresectable oesophageal tumours. Many surgical series have reported on distribution of lymph node metastases (LNM) in resected patients. However, no data is available on the distribution of at-risk LN regions in this more unfavourable patient group. This study aimed to determine the spread of LNM using FDG-PET/CT, to compare it with the distribution in surgical series and to define its impact on the definition of elective LN irradiation (ENI). FDG-PET/CT images of patients with oesophageal cancer treated with dCRT (from 2003 to 2013) were reviewed to identify the anatomic distribution of FDG-avid LNs. Tumours were divided according to proximal, mid-thoracic or distal localisation. About 105 consecutive patients entered analysis. The highest numbers of FDG-avid LNs in proximal tumours were at LN station 101R (45%) and 106recL (35%). For mid-thoracic tumours at 104R (30%) and 105 (30%). For tumours located in the distal oesophagus, the most common sites were along the lesser curvature of the stomach (21%) and the left gastric artery (21%). Except for the supraclavicular and pretracheal nodes, there were no positive locoregional LNM found outside the standard surgical resection area. Our results show a good correlation between the distribution of nodal volumes at risk in surgical series and on FDG-PET/CT. The results can be used to determine target definition in dCRT for oesophageal cancer. For mid-thoracic tumours, the current target delineation guidelines may be extended based on the risk of node involvement, but more clinical studies are needed to determine if the potential harm of expanding the CTV outweighs the potential benefit. © 2016 The Royal Australian and New Zealand College of Radiologists.

  8. Standardizing terms, definitions and concepts for describing and interpreting unwanted immunogenicity of biopharmaceuticals

    DEFF Research Database (Denmark)

    Rup, B; Pallardy, M; Sikkema, D

    2015-01-01

    scientists are involved in: interpretation and management of clinical and biological outcomes of BP immunogenicity, improvement of methods for describing, predicting and mitigating immunogenicity risk and elucidation of underlying causes. Collaboration and alignment of efforts across these communities...... the Risk; www.abirisk.eu] was formed by leading clinicians, academic scientists and EFPIA (European Federation of Pharmaceutical Industries and Associations) members to elucidate underlying causes, improve methods for immunogenicity prediction and mitigation and establish common definitions around terms...

  9. Satellite Power Systems (SPS) concept definition study, exhibit C. Volume 2, part 1: System engineering

    Science.gov (United States)

    Hanley, G. M.

    1979-01-01

    Volume 2, Part 1, of a seven volume report is presented. Part 1 encompasses Satellite Power Systems (SPS) systems engineering aspects and is divided into three sections. The first section presents descriptions of the various candidate concepts considered and conclusions and recommendations for a preferred concept. The second section presents a summary of results of the various trade studies and analysis conducted during the course of the study. The third section describes the Photovoltaic Satellite Based Satellite Power System (SPS) Point Design as it was defined through studies performed during the period January 1977 through March 1979.

  10. PET/CT Improves the Definition of Complete Response and Allows to Detect Otherwise Unidentifiable Skeletal Progression in Multiple Myeloma.

    Science.gov (United States)

    Zamagni, Elena; Nanni, Cristina; Mancuso, Katia; Tacchetti, Paola; Pezzi, Annalisa; Pantani, Lucia; Zannetti, Beatrice; Rambaldi, Ilaria; Brioli, Annamaria; Rocchi, Serena; Terragna, Carolina; Martello, Marina; Marzocchi, Giulia; Borsi, Enrica; Rizzello, Ilaria; Fanti, Stefano; Cavo, Michele

    2015-10-01

    To evaluate the role of 18F-FDG PET/CT in 282 symptomatic multiple myeloma patients treated up-front between 2002 and 2012. All patients were studied by PET/CT at baseline, during posttreatment follow-up, and at the time of relapse. Their median duration of follow-up was 67 months. Forty-two percent of the patients at diagnosis had >3 focal lesions, and in 50% SUVmax was >4.2; extramedullary disease was present in 5%. On multivariate analysis, ISS stage 3, SUVmax >4.2, and failure to achieve best complete response (CR) were the leading factors independently associated with shorter progression-free survival (PFS) and overall survival (OS). These 3 variables were used to construct a prognostic scoring system based on the number of risk factors. After treatment, PET/CT negativity (PET-neg) was observed in 70% of patients, whereas conventionally defined CR was achieved in 53%. Attainment of PET-neg favorably influenced PFS and OS. PET-neg was an independent predictor of prolonged PFS and OS for patients with conventionally defined CR. Sixty-three percent of patients experienced relapse or progression; in 12%, skeletal progression was exclusively detected by systematic PET/CT performed during follow-up. A multivariate analysis revealed that persistence of SUVmax >4.2 following first-line treatment was independently associated with exclusive PET/CT progression. PET/CT combined with ISS stage and achievement or not of CR on first-line therapy sorted patients into different prognostic groups. PET/CT led to a more careful evaluation of CR. Finally, in patients with persistent high glucose metabolism after first-line treatment, PET/CT can be recommended during follow-up, to screen for otherwise unidentifiable progression. ©2015 American Association for Cancer Research.

  11. Integrated Technology Rotor/Flight Research Rotor (ITR/FRR) concept definition study

    Science.gov (United States)

    Hughes, C. W.

    1983-01-01

    Studies were conducted by Hughes Helicopters, Inc. (HHI) for the Applied Technology Laboratory and Aeromechanics Laboratory, U.S. Army Research and Technology Laboratories (AVRADCOM) and the Ames Research Center, National Aeronautics and Space Administration (NASA). Results of predesign studies of advanced main rotor hubs, including bearingless designs, are presented in this report. In addition, the Government's rotor design goals and specifications were reviewed and evaluated. Hub concepts were designed and qualitatively evaluated in order to select the two most promising concepts for further development. Various flexure designs, control systems, and pitchcase designs were investigated during the initial phases of this study. The two designs selected for additional development were designated the V-strap and flat-strap cruciform hubs. These hubs were designed for a four bladed rotor and were sized for 18,400 pounds gross weight with the same diameter (62 feet) and solidity (23 inch chord) as the existing rotor on the Rotor Systems Research Aircraft (RSRA).

  12. Economic Image Media Text: Definition of the Concept and its Content

    Directory of Open Access Journals (Sweden)

    Anastasia V. Kudrina

    2017-12-01

    Full Text Available The article describes the concept of economic image media text and its significance for participants of economic relations. The image factor is one of the ways to gain a place in the economic market, therefore media resources - journalism, advertising and PR are actively used by businessmen and companies with the widest range of pragmatic goals. The concept of the political image and the political image media text as a means of its implementation are known both among media users and among researchers. In spite of the fact that economic relations are closely connected with political ones, and economic factors often determine political processes, practically nothing is known about the economic image media text in the circle of media researchers.

  13. Design concept definition study for an improved shuttle waste collection subsystem

    Science.gov (United States)

    1984-01-01

    A no-risk approach for developing an Improved Waste Collection Subsystem (WCS) for the shuttle orbiter is described. The GE Improved WCS Concept builds on the experience of 14 Shuttle missions with over 400 man-days of service. This concept employs the methods of the existing flight-proven mature design, augmenting them to eliminate foreseen difficulties and to fully comply with the design requirements. The GE Improved WCS Concept includes separate storage for used wipes. Compaction of the wipes provides a solution to the capacity problem, fully satisfying the 210 man-day storage requirement. The added feature of in-flight serviceable storage space for the wipes creates a variable capacity feature which affords redundancy in the event of wipes compaction system failure. Addition of features permitting in-flight servicing of the feces storage tank creates a variable capacity WCS with easier post-flight servicing to support rapid turnaround of the Shuttle orbiter. When these features are combined with a vacuum pump to evacuate wipes and fecal storage tanks through replaceable odor/bacteria filters to the cabin, the GE Improved WCS satisfies the known requirements for Space Station use, including no venting to space.

  14. Transactional Infrastructure of the Economy: the Evolution of Concepts and Synthesis of Definitions

    Directory of Open Access Journals (Sweden)

    Maruschak Irina Valeryevna

    2017-03-01

    Full Text Available The overview of evolution of market infrastructure concepts is provided, the first concepts of institutional infrastructure are revealed in the paper. Evolutionarily developed narrowing of essence of infrastructure in connection with the priority analysis of its physical (material and technological components is proved. It ignores the fact that transactional resources, being drivers (driving forces of economic systems evolution, in turn evolve, becoming harder and harder, combining increase in efficiency of the elements and strengthening of heterogeneity and discrepancy of their structure. Transactional evolution of economy in general and evolution of separate transactional resources of production are the perspective directions of the special analysis. Transactional infrastructure is considered as the integrated complex of institutional, organizational (relational and information infrastructures. The problems of the first concepts of transactional infrastructure connected with difficulties of differentiation of its subsystems always operating jointly are revealed. Prospect of transition from the isolated analysis of separate resources of transactional type (institutes, organizations, information, social capital, trust, etc. to studying corresponding specific software infrastructures and to the system analysis of integrated transactional infrastructure of economy are argued. The transactional sector (as set of the specialized industries and the appropriate collective and individual subjects providing with resources market transaction is offered to be considered as transactional structure of economy. Transactional infrastructure is treated as critically significant factor of economic evolution which in the conditions of post-industrial type of economy gradually purchases transactional nature.

  15. Concepts leading to the definition of the term cervicogenic headache: a historical overview.

    Science.gov (United States)

    Antonaci, Fabio; Bono, Giorgio; Mauri, Marco; Drottning, Monica; Buscone, Simona

    2005-12-01

    The idea that headache may originate from a problem at the neck or cervical spine level has fascinated and stimulated researchers for centuries. Contributions and reports seeking to clarify this issue have multiplied in the past 80 or 90 years. Bärtschi-Rochaix reported what seems to have been the first clinical description of cervicogenic headache, but it was not until 1983 that Sjaastad and his school defined diagnostic criteria for this syndrome. The current, revised International Headache Society Classification (ICHD-II) includes the term cervicogenic headache, but the diagnostic criteria it gives differ from those of the International Association for the Study of Pain (IASP), and also from the most recent Cervicogenic Headache International Study Group (CHISG) definition (1998).

  16. A 4D global respiratory motion model of the thorax based on CT images: A proof of concept.

    Science.gov (United States)

    Fayad, Hadi; Gilles, Marlene; Pan, Tinsu; Visvikis, Dimitris

    2018-05-17

    Respiratory motion reduces the sensitivity and specificity of medical images especially in the thoracic and abdominal areas. It may affect applications such as cancer diagnostic imaging and/or radiation therapy (RT). Solutions to this issue include modeling of the respiratory motion in order to optimize both diagnostic and therapeutic protocols. Personalized motion modeling required patient-specific four-dimensional (4D) imaging which in the case of 4D computed tomography (4D CT) acquisition is associated with an increased dose. The goal of this work was to develop a global respiratory motion model capable of relating external patient surface motion to internal structure motion without the need for a patient-specific 4D CT acquisition. The proposed global model is based on principal component analysis and can be adjusted to a given patient anatomy using only one or two static CT images in conjunction with a respiratory synchronized patient external surface motion. It is based on the relation between the internal motion described using deformation fields obtained by registering 4D CT images and patient surface maps obtained either from optical imaging devices or extracted from CT image-based patient skin segmentation. 4D CT images of six patients were used to generate the global motion model which was validated by adapting it on four different patients having skin segmented surfaces and two other patients having time of flight camera acquired surfaces. The reproducibility of the proposed model was also assessed on two patients with two 4D CT series acquired within 2 weeks of each other. Profile comparison shows the efficacy of the global respiratory motion model and an improvement while using two CT images in order to adapt the model. This was confirmed by the correlation coefficient with a mean correlation of 0.9 and 0.95 while using one or two CT images respectively and when comparing acquired to model generated 4D CT images. For the four patients with segmented

  17. Satellite Power Systems (SPS) concept definition study, exhibit C. Volume 2, part 2: System engineering, cost and programmatics

    Science.gov (United States)

    Hanley, G. M.

    1979-01-01

    Volume 2, Part 2, of a seven volume Satellite Power Systems (SPS) report is presented. Part 2 covers cost and programmatics and is divided into four sections. The first section gives illustrations of the SPS reference satellite and rectenna concept, and an overall scenario for SPS space transportation involvement. The second section presents SPS program plans for the implementation of PHASE C/D activities. These plans describe SPS program schedules and networks, critical items of systems evolution/technology development, and the natural resources analysis. The fourth section presents summary comments on the methods and rationale followed in arriving at the results documented. Suggestions are also provided in those areas where further analysis or evaluation will enhance SPS cost and programmatic definitions.

  18. Integrated Technology Rotor/Flight Research Rotor (ITR/FRR) concept definition

    Science.gov (United States)

    Howes, H. E.; Tomashofski, C. A.

    1983-01-01

    A program was performed to identify and evaluate a variety of candidate rotor hub configurations for the ITR/FRR. Design criteria were established for the development of the hub concepts. Five initial hub configurations were examined and two were selected for further refinement and evaluation. The selected configurations were bearingless designs. The Classic Elastic Pitch Beam (CEPB) and the Plain Elastic Pitch Beam (PEPB), both exhibit superior qualities for the criteria in the final evalution. The CEPB is favored over the PEPB primarily because it offers better capability for built in damping for stability and is judged to have a lower risk in development.

  19. Concept definition study for recovery of tumbling satellites. Volume 2: Supporting research and technology report

    Science.gov (United States)

    Cable, D. A.; Derocher, W. L., Jr.; Cathcart, J. A.; Keeley, M. G.; Madayev, L.; Nguyen, T. K.; Preese, J. R.

    1986-01-01

    A number of areas of research and laboratory experiments were identified which could lead to development of a cost efficient remote, disable satellite recovery system. Estimates were planned of disabled satellite motion. A concept is defined as a Tumbling Satellite Recovery kit which includes a modular system, composed of a number of subsystem mechanisms that can be readily integrated into varying combinations. This would enable the user to quickly configure a tailored remote, disabled satellite recovery kit to meet a broad spectrum of potential scenarios. The capability was determined of U.S. Earth based satellite tracking facilities to adequately determine the orientation and motion rates of disabled satellites.

  20. A degree of controllability definition - Fundamental concepts and application to modal systems

    Science.gov (United States)

    Viswanathan, C. N.; Longman, R. W.; Likins, P. W.

    1984-01-01

    Starting from basic physical considerations, this paper develops a concept of the degree of controllability of a control system, and then develops numerical methods to generate approximate values of the degree of controllability for any linear time-invariant system. In many problems, such as the control of future, very large, flexible spacecraft and certain chemical process control problems, the question of how to choose the number and locations of the control system actuators is an important one. The results obtained here offer the control system designer a tool which allows him to rank the effectiveness of alternative actuator distributions, and hence to choose the actuator locations on a rational basis. The degree of controllability is shown to take a particularly simple form when the dynamic equations of a satellite are in second-order modal form. The degree of controllability concept has still other fundamental uses - it allows one to study the system structural relations between the various inputs and outputs of a linear system, which has applications to decoupling and model reduction.

  1. The radioactive waste management concept: problem definition and solving in Latvia

    International Nuclear Information System (INIS)

    Dreimanis, A.; Shatrovska, D.

    2003-01-01

    Development of radioactive waste (RW) management concept is treated as a key component of a general process - elaboration of the overall RW management strategy for a certain country/region. We present indication of possible solutions for crucial RW management problems for Latvia being in the same time rather generic for other countries. The importance of the Concept for Latvia follows from the planned decommissioning of the Salaspils Research Reactor (SRR) and from the recommended further upgrading of RW management organization in conditions of limited resources.The aim of this Concept is to stimulate the development of advanced, environmentally sound and population friendly system of RW management, in accord with the fair social system for the protection of human health and the environment, in line of international recommendations.The Concept foresees solutions for the safe management of RW for the period 2003-2010. The main problems to be analysed and solved in the Concept: 1.The increase of the RW quantity and a lack of the sufficient storage space. In addition to the traditional producers of RW such as medicine, industry, and science, there are two major operators in Latvia that have significantly increase the yearly amount of RW for disposal in recent years and will do so in nearest future - disposal off of the SRR decommissioning waste in the existing near-surface LILW-SL RW repository, which dictates the need for its enlargement. 2. The safety of the existent repository. To ensure protection of population and environment (including the Baltic sea) from exposure and radioactive contamination, proper measures shall be taken. The safety of RW repository should be upgraded via building long-term cover, according to recommendations of safety assessment (SA) by consortium CASSIOPEA. 3. Construction of a long term storage and the geological disposal site. Safe isolation of long-lived RW can be achieved by storage in the geological disposal site only, thereby; a

  2. [Food addiction: Definition, measurement and limits of the concept, associated factors, therapeutic and clinical implications].

    Science.gov (United States)

    Cathelain, Sarah; Brunault, Paul; Ballon, Nicolas; Réveillère, Christian; Courtois, Robert

    2016-12-01

    Addictions, which are characterized by the inability to control a behavior despite existence of physical or psychological consequences, have biological, psychological and social determinants. Although the possibility of developing an addiction to some psychoactive substances (e.g. alcohol, tobacco, cannabis) and to gambling (i.e., gambling disorder) is now well demonstrated, the possibility to develop a non-drug addiction (i.e., behavioral addiction) to certain behaviors which provide pleasure (e.g. eating, having sex, buying things) is still in debate. The concept of food addiction, which refers to people who exhibit substance dependence criteria in relation to some high-fat and high-sugar foods, was recently proposed by applying substance dependence DSM criteria to eating behavior. To assess food addiction, the Yale Food Addiction Scale is now the only self-administered questionnaire (diagnosis and estimate of the number of symptoms of food addiction). Prevalence for food addiction is higher in overweight and obese patients, and in patients with certain psychopathological characteristics (i.e., depression, Attention Deficit Hyperactivity Disorder, high impulsivity), in patients who are single and in patients with neurobiological alterations in the reward system. However, it is still unclear whether food addiction is necessary associated with subsequent increase in body weight and/or obesity. An increasing number of studies demonstrated that drug addiction and food addiction shares some similar clinical, neurobiological and psychopathological and sociocultural risk factors. To test the pertinence to include food addiction as an addiction, it would be interesting to conduct future studies in patients who may experience harms related to their food addiction, including not only patients with obesity, but also patients with metabolic syndrome, type 2 diabetes, hypertension, dyslipidemia, atherosclerosis, stroke, or coronary heart disease. Food addiction is a clinical

  3. CHERENCUBE: Concept definition and implementation challenges of a Cherenkov-based detector block for PET

    International Nuclear Information System (INIS)

    Somlai-Schweiger, I.; Ziegler, S. I.

    2015-01-01

    Purpose: A new concept for a depth-of-interaction (DOI) capable time-of-flight (TOF) PET detector is defined, based only on the detection of Cherenkov photons. The proposed “CHERENCUBE” consists of a cubic Cherenkov radiator with position-sensitive photodetectors covering each crystal face. By means of the spatial distribution of the detected photons and their time of arrival, the point of interaction of the gamma-ray in the crystal can be determined. This study analyzes through theoretical calculations and Monte Carlo simulations the potential advantages of the concept toward reaching a Cherenkov-only detector for TOF-PET with DOI capability. Furthermore, an algorithm for the DOI estimation is presented and the requirements for a practical implementation of the proposed concept are defined. Methods: The Monte Carlo simulations consisted of a cubic crystal with one photodetector coupled to each one of the faces of the cube. The sensitive area of the detector matched exactly the crystal size, which was varied in 1 mm steps between 1 × 1 × 1 mm 3 and 10 × 10 × 10 mm 3 . For each size, five independent simulations of ten thousand 511 keV gamma-rays were triggered at a fixed distance of 10 mm. The crystal chosen was PbWO 4 . Its scintillation properties were simulated, but only Cherenkov photons were analyzed. Photodetectors were simulated having perfect photodetection efficiency and infinite time resolution. For every generated particle, the analysis considered its creation process, parent and daughter particles, energy, origin coordinates, trajectory, and time and position of detection. The DOI determination is based on the distribution of the emission time of all photons per event. These values are calculated as a function of the coordinates of detection and origin for every photon. The common origin is estimated by finding the distribution with the most similar emission time-points. Results: Detection efficiency increases with crystal size from 8.2% (1 × 1

  4. Delivering on a gendered definition of health needs in local government budgeting: experiences and concepts.

    Science.gov (United States)

    Buyana, K

    2009-10-01

    Local governments are granted budgetary power in the Local Governments Act of the Republic of Uganda, which allows for local-level participation and flexibility in the allocation of financial grants channelled annually from central to local governments. The act prescribes a legal mandate to allocate public resources based on local priorities including the health needs of women compared with men. This study investigated the responsiveness of local government budgeting to the health needs of women as compared to men. A qualitative study was conducted in Mpigi district using a set of data collection methods including: a) three (3) focus group discussions with 8 female and 8 male respondents in each group; b) face-to-face interviews with a random sample of 120 households, 75% of which were male-headed and 25% female-headed ; c) key informant interviews with a sample of 10 administrative officers in Mpigi district ; and d) desk-review of the Mpigi district Budget Framework Paper. Health needs consist of the daily requirements, which, arise out of common disease infections and the socioeconomic constraints that affect the well-being of women and men. However, the primary concern of the district health sector is disease control measures, without emphasis on the differing socio-economic interests of women as compared to men. Local government budgeting, therefore, does not reflect the broad community-wide understanding of health needs. Local government budgeting should be informed by a two-fold framework for the gendered definition of health needs. The two-fold framework combines both disease-based health needs and socio-economic needs of women as compared to men.

  5. Key Concepts in Education: Critical Issues beyond Definition and Discursive Practices

    Directory of Open Access Journals (Sweden)

    Theo Hug

    2013-11-01

    Full Text Available Along with the processes of digitization, medialization and the globalization of communications and lifeworlds, new topics, subject matters, conceptualizations and methods have been deve­loped in educational research and practice. On the one hand, from a diachronic perspective we can notice how new aspects of education (Bildung, upbringing (Erziehung, learning and communication have been addressed. On the other hand, from a synchronic perspective we can see a simultaneity of the non-simultaneous in terms of understandings, approaches, methodologies and forms of mediation and collaboration. Although more and more open initiatives and open educational resources (OER, as well as international collaborations and transnational intellectual networks, are being brought forward, epistemological aspects about using different key concepts are widely underestimated. The paper starts with: (1 an outline of selected understandings of education and literacy, followed by (2 a discussion of critical epistemological aspects by way of contrasting and correlating conceptual dimensions. Lastly, the contribution aims at (3 a sketch of polylogical design principles for educational knowledge organization.

  6. CHERENCUBE: Concept definition and implementation challenges of a Cherenkov-based detector block for PET

    Energy Technology Data Exchange (ETDEWEB)

    Somlai-Schweiger, I., E-mail: ian.somlai@tum.de; Ziegler, S. I. [Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, München 81675 (Germany)

    2015-04-15

    Purpose: A new concept for a depth-of-interaction (DOI) capable time-of-flight (TOF) PET detector is defined, based only on the detection of Cherenkov photons. The proposed “CHERENCUBE” consists of a cubic Cherenkov radiator with position-sensitive photodetectors covering each crystal face. By means of the spatial distribution of the detected photons and their time of arrival, the point of interaction of the gamma-ray in the crystal can be determined. This study analyzes through theoretical calculations and Monte Carlo simulations the potential advantages of the concept toward reaching a Cherenkov-only detector for TOF-PET with DOI capability. Furthermore, an algorithm for the DOI estimation is presented and the requirements for a practical implementation of the proposed concept are defined. Methods: The Monte Carlo simulations consisted of a cubic crystal with one photodetector coupled to each one of the faces of the cube. The sensitive area of the detector matched exactly the crystal size, which was varied in 1 mm steps between 1 × 1 × 1 mm{sup 3} and 10 × 10 × 10 mm{sup 3}. For each size, five independent simulations of ten thousand 511 keV gamma-rays were triggered at a fixed distance of 10 mm. The crystal chosen was PbWO{sub 4}. Its scintillation properties were simulated, but only Cherenkov photons were analyzed. Photodetectors were simulated having perfect photodetection efficiency and infinite time resolution. For every generated particle, the analysis considered its creation process, parent and daughter particles, energy, origin coordinates, trajectory, and time and position of detection. The DOI determination is based on the distribution of the emission time of all photons per event. These values are calculated as a function of the coordinates of detection and origin for every photon. The common origin is estimated by finding the distribution with the most similar emission time-points. Results: Detection efficiency increases with crystal size from

  7. Fully automatic segmentation of femurs with medullary canal definition in high and in low resolution CT scans.

    Science.gov (United States)

    Almeida, Diogo F; Ruben, Rui B; Folgado, João; Fernandes, Paulo R; Audenaert, Emmanuel; Verhegghe, Benedict; De Beule, Matthieu

    2016-12-01

    Femur segmentation can be an important tool in orthopedic surgical planning. However, in order to overcome the need of an experienced user with extensive knowledge on the techniques, segmentation should be fully automatic. In this paper a new fully automatic femur segmentation method for CT images is presented. This method is also able to define automatically the medullary canal and performs well even in low resolution CT scans. Fully automatic femoral segmentation was performed adapting a template mesh of the femoral volume to medical images. In order to achieve this, an adaptation of the active shape model (ASM) technique based on the statistical shape model (SSM) and local appearance model (LAM) of the femur with a novel initialization method was used, to drive the template mesh deformation in order to fit the in-image femoral shape in a time effective approach. With the proposed method a 98% convergence rate was achieved. For high resolution CT images group the average error is less than 1mm. For the low resolution image group the results are also accurate and the average error is less than 1.5mm. The proposed segmentation pipeline is accurate, robust and completely user free. The method is robust to patient orientation, image artifacts and poorly defined edges. The results excelled even in CT images with a significant slice thickness, i.e., above 5mm. Medullary canal segmentation increases the geometric information that can be used in orthopedic surgical planning or in finite element analysis. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  8. Added diagnostic benefit of 16-row whole-body spiral CT in patients with multiple trauma differentiated by region and injury severity according to the ATLS registered concept

    International Nuclear Information System (INIS)

    Maurer, M.H.; Knopke, S.; Schroeder, R.J.

    2008-01-01

    Purpose: to determine the added diagnostic benefit of using MS-CT in multiple trauma patients differentiated by severity of injury and affected body region. Materials and methods: a retrospective analysis was performed of the 16-row whole-body spiral CT findings in 275 multiple trauma patients (73% men, 27% women; age 39.6 ± 18.9 years) with regard to additional findings and new findings obtained with CT compared to the findings obtained by conventional projection radiography and abdominal ultrasound in the emergency room. The additional and new findings were differentiated by body region (head, face, chest, pelvis, abdomen, spine) and the degree of severity according to the three classes of injuries distinguished by the ATLS registered concept (class 1: simple injury, class 2: potentially life threatening, class 3: immediately life threatening). Results: a total of 921 additional findings (findings potentially relevant for further diagnosis and therapy in addition to the findings obtained by conventional radiography or ultrasound) were obtained by MS-CT in all patients. The distribution by number of patients and body region was as follows: 22 neck, 76 face, 125 chest, 112 abdomen, 50 pelvis, and 91 spine. Most additional findings were categorized as potentially life threatening (ATLS class 2). In addition, there were 439 completely new findings, involving the head in 128 patients (mostly ATLS class 3), the face in 18, the chest in 47, the abdomen in 26, and the spine in 9 patients. Most new findings involving the face, abdomen, and spine were ATLS class 2 injuries. (orig.)

  9. Evaluation of the role of 18FDG-PET/CT in radiotherapy target definition in patients with head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Newbold, Katie L; Partridge, Mike; Cook, Gary; Sharma, Bhupinder; Rhys-Evans, Peter; Harrington, Kevin J; Nutting, Christopher M [The Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom)

    2008-08-15

    Background and purpose. As techniques for radiotherapy delivery have developed, increasingly accurate localisation of disease is demanded. Functional imaging, particularly PET and its fusion with anatomical modalities, such as PET/CT, promises to improve detection and characterisation of disease. This study evaluated the impact of 18FDG-PET/CT on radiotherapy target volume definition in head and neck cancer (HNC). Materials and methods. The PET/CT scans of patients with HNC were used in a radiotherapy planning (RTP) study. The gross tumour volume (GTV), clinical target volume (CTV) and planning target volume (PTV) were defined conventionally and compared to those defined using the PET/CT. Data were reported as the median value with 95% confidence intervals. Results. Eighteen patients were consented, 9 had known primary tumour site, 9 presented as unknown primary. In nine cases where the primary site was known, the combined primary and nodal GTV (GTVp+n) increased by a median of 6.1cm3 (2.6, 12.2) or 78% (18, 313), p=0.008 with CTV increasing by a median of 10.1cm3 (1.3, 30.6) or 4% (0, 13) p=0.012. In 9 cases of unknown primary the GTVp+n increased by a median 6.3cm3 (0.2, 15.7) or 61% (4, 210), p=0.012, with CTV increasing by a median 155.4cm3 (2.7, 281.7) or 95% (1, 137), p=0.008. Conclusion. 18FDG-PET revealed disease lying outside the conventional target volume, either extending a known area or highlighting a previously unknown area of disease, including the primary tumour in 5 cases. We recommend PET/CT in the RTP of all cases of unknown primary. In patients with a known primary, although the change in volume was statistically significant the clinical impact is less clear. 18FDG-PET can also show areas within the conventional target volume that are hypermetabolic which may be possible biological target volumes for dose escalation studies in the future

  10. Definition of the supraclavicular and infraclavicular nodes: implications for three-dimensional CT-based conformal radiation therapy.

    Science.gov (United States)

    Madu, C N; Quint, D J; Normolle, D P; Marsh, R B; Wang, E Y; Pierce, L J

    2001-11-01

    To delineate with computed tomography (CT) the anatomic regions containing the supraclavicular (SCV) and infraclavicular (IFV) nodal groups, to define the course of the brachial plexus, to estimate the actual radiation dose received by these regions in a series of patients treated in the traditional manner, and to compare these doses to those received with an optimized dosimetric technique. Twenty patients underwent contrast material-enhanced CT for the purpose of radiation therapy planning. CT scans were used to study the location of the SCV and IFV nodal regions by using outlining of readily identifiable anatomic structures that define the nodal groups. The brachial plexus was also outlined by using similar methods. Radiation therapy doses to the SCV and IFV were then estimated by using traditional dose calculations and optimized planning. A repeated measures analysis of covariance was used to compare the SCV and IFV depths and to compare the doses achieved with the traditional and optimized methods. Coverage by the 90% isodose surface was significantly decreased with traditional planning versus conformal planning as the depth to the SCV nodes increased (P correlation was found between brachial plexus depth and SCV depth up to 7 cm. Conformal optimized planning provided improved dosimetric coverage compared with standard techniques.

  11. A three-dimensional definition of nodal spaces on the basis of CT images showing enlarged nodes for pelvic radiotherapy

    International Nuclear Information System (INIS)

    Portaluri, Maurizio; Bambace, Santa; Perez, Celeste; Angone, Grazia

    2005-01-01

    Purpose: To demonstrate that margins of each pelvic chain may be derived by verifying the bony and soft tissue structures around abnormal nodes on computed tomography (CT) slices. Methods and Materials: Twenty consecutive patients (16 males, 4 females; mean age, 66 years; range, 43-80 years) with radiologic diagnosis of nodal involvement by histologically proved cervix carcinoma (two), rectum carcinoma (three), prostate carcinoma (four), lymphoma (five), penis carcinoma (one), corpus uteri carcinoma (one), bladder carcinoma (two), cutis tumor (one), and soft-tissue sarcoma (one) were retrospectively reviewed. One hundred CT scans showing 85 enlarged pelvic nodes were reviewed by two radiation oncologists (M.P., S.B.), and two radiologists (C.P., G.A.). Results: The more proximal structures to each enlarged node or group of nodes were thus recorded in a clockwise direction. Conclusion: According to their frequency and visibility, craniocaudal, anterior, lateral, posterior and medial margins of common iliac, external and internal iliac nodal chains, obturator and pudendal nodes, and deep and superficial inguinal nodes were derived from CT observations

  12. A novel concept for CT with fixed anodes (FACT): Medical imaging based on the feasibility of thermal load capacity.

    Science.gov (United States)

    Kellermeier, Markus; Bert, Christoph; Müller, Reinhold G

    2015-07-01

    Focussing primarily on thermal load capacity, we describe the performance of a novel fixed anode CT (FACT) compared with a 100 kW reference CT. Being a fixed system, FACT has no focal spot blurring of the X-ray source during projection. Monte Carlo and finite element methods were used to determine the fluence proportional to thermal capacity. Studies of repeated short-time exposures showed that FACT could operate in pulsed mode for an unlimited period. A virtual model for FACT was constructed to analyse various temporal sequences for the X-ray source ring, representing a circular array of 1160 fixed anodes in the gantry. Assuming similar detector properties at a very small integration time, image quality was investigated using an image reconstruction library. Our model showed that approximately 60 gantry rounds per second, i.e. 60 sequential targetings of the 1160 anodes per second, were required to achieve a performance level equivalent to that of the reference CT (relative performance, RP = 1) at equivalent image quality. The optimal projection duration in each direction was about 10 μs. With a beam pause of 1 μs between projections, 78.4 gantry rounds per second with consecutive source activity were thermally possible at a given thermal focal spot. The settings allowed for a 1.3-fold (RP = 1.3) shorter scan time than conventional CT while maintaining radiation exposure and image quality. Based on the high number of rounds, FACT supports a high image frame rate at low doses, which would be beneficial in a wide range of diagnostic and technical applications. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  13. An evaluation of the variability of tumor-shape definition derived by experienced observers from CT images of supraglottic carcinomas (ACRIN protocol 6658)

    International Nuclear Information System (INIS)

    Cooper, Jay S.; Mukherji, Suresh K.; Toledano, Alicia Y.; Beldon, Clifford; Schmalfuss, Ilona M.; Amdur, Robert; Sailer, Scott; Loevner, Laurie A.; Kousouboris, Phil; Ang, K. Kian; Cormack, Jean; Sicks, JoRean M.S.

    2007-01-01

    Purpose: Accurate target definition is considered essential for sophisticated, image-guided radiation therapy; however, relatively little information has been reported that measures our ability to identify the precise shape of targets accurately. We decided to assess the manner in which eight 'experts' interpreted the size and shape of tumors based on 'real-life' contrast-enhanced computed tomographic (CT) scans. Methods and Materials: Four neuroradiologists and four radiation oncologists (the authors) with considerable experience and presumed expertise in treating head-and-neck tumors independently contoured, slice-by-slice, his/her interpretation of the precise gross tumor volume (GTV) on each of 20 sets of CT scans taken from 20 patients who previously were enrolled in Radiation Therapy Oncology Group protocol 91-11. Results: The average proportion of overlap (i.e., the degree of agreement) was 0.532 (95% confidence interval 0.457 to 0.606). There was a slight tendency for the proportion of overlap to increase with increasing average GTV. Conclusions: Our work suggests that estimation of tumor shape currently is imprecise, even for experienced physicians. In consequence, there appears to be a practical limit to the current trend of smaller fields and tighter margins

  14. Co-registration of pre-operative CT with ex vivo surgically excised ground glass nodules to define spatial extent of invasive adenocarcinoma on in vivo imaging: a proof-of-concept study

    Energy Technology Data Exchange (ETDEWEB)

    Rusu, Mirabela [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); GE Global Research, Niskayuna, NY (United States); Rajiah, Prabhakar [UT Southwestern Medical Center, Dallas, TX (United States); Cleveland Medical Center and Case Western Reserve University, University Hospitals, Cleveland, OH (United States); Gilkeson, Robert; Yang, Michael; Donatelli, Christopher; Linden, Philip [Cleveland Medical Center and Case Western Reserve University, University Hospitals, Cleveland, OH (United States); Thawani, Rajat; Madabhushi, Anant [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); Jacono, Frank J. [Cleveland Medical Center and Case Western Reserve University, University Hospitals, Cleveland, OH (United States); Louis Stokes Cleveland VA Medical Center, Cleveland, OH (United States)

    2017-10-15

    To develop an approach for radiology-pathology fusion of ex vivo histology of surgically excised pulmonary nodules with pre-operative CT, to radiologically map spatial extent of the invasive adenocarcinomatous component of the nodule. Six subjects (age: 75 ± 11 years) with pre-operative CT and surgically excised ground-glass nodules (size: 22.5 ± 5.1 mm) with a significant invasive adenocarcinomatous component (>5 mm) were included. The pathologist outlined disease extent on digitized histology specimens; two radiologists and a pulmonary critical care physician delineated the entire nodule on CT (in-plane resolution: <0.8 mm, inter-slice distance: 1-5 mm). We introduced a novel reconstruction approach to localize histology slices in 3D relative to each other while using CT scan as spatial constraint. This enabled the spatial mapping of the extent of tumour invasion from histology onto CT. Good overlap of the 3D reconstructed histology and the nodule outlined on CT was observed (65.9 ± 5.2%). Reduction in 3D misalignment of corresponding anatomical landmarks on histology and CT was observed (1.97 ± 0.42 mm). Moreover, the CT attenuation (HU) distributions were different when comparing invasive and in situ regions. This proof-of-concept study suggests that our fusion method can enable the spatial mapping of the invasive adenocarcinomatous component from 2D histology slices onto in vivo CT. (orig.)

  15. Co-registration of pre-operative CT with ex vivo surgically excised ground glass nodules to define spatial extent of invasive adenocarcinoma on in vivo imaging: a proof-of-concept study

    International Nuclear Information System (INIS)

    Rusu, Mirabela; Rajiah, Prabhakar; Gilkeson, Robert; Yang, Michael; Donatelli, Christopher; Linden, Philip; Thawani, Rajat; Madabhushi, Anant; Jacono, Frank J.

    2017-01-01

    To develop an approach for radiology-pathology fusion of ex vivo histology of surgically excised pulmonary nodules with pre-operative CT, to radiologically map spatial extent of the invasive adenocarcinomatous component of the nodule. Six subjects (age: 75 ± 11 years) with pre-operative CT and surgically excised ground-glass nodules (size: 22.5 ± 5.1 mm) with a significant invasive adenocarcinomatous component (>5 mm) were included. The pathologist outlined disease extent on digitized histology specimens; two radiologists and a pulmonary critical care physician delineated the entire nodule on CT (in-plane resolution: <0.8 mm, inter-slice distance: 1-5 mm). We introduced a novel reconstruction approach to localize histology slices in 3D relative to each other while using CT scan as spatial constraint. This enabled the spatial mapping of the extent of tumour invasion from histology onto CT. Good overlap of the 3D reconstructed histology and the nodule outlined on CT was observed (65.9 ± 5.2%). Reduction in 3D misalignment of corresponding anatomical landmarks on histology and CT was observed (1.97 ± 0.42 mm). Moreover, the CT attenuation (HU) distributions were different when comparing invasive and in situ regions. This proof-of-concept study suggests that our fusion method can enable the spatial mapping of the invasive adenocarcinomatous component from 2D histology slices onto in vivo CT. (orig.)

  16. Concepts and definitions for "supportive care," "best supportive care," "palliative care," and "hospice care" in the published literature, dictionaries, and textbooks.

    Science.gov (United States)

    Hui, David; De La Cruz, Maxine; Mori, Masanori; Parsons, Henrique A; Kwon, Jung Hye; Torres-Vigil, Isabel; Kim, Sun Hyun; Dev, Rony; Hutchins, Ronald; Liem, Christiana; Kang, Duck-Hee; Bruera, Eduardo

    2013-03-01

    Commonly used terms such as "supportive care," "best supportive care," "palliative care," and "hospice care" were rarely and inconsistently defined in the palliative oncology literature. We conducted a systematic review of the literature to further identify concepts and definitions for these terms. We searched MEDLINE, PsycInfo, EMBASE, and CINAHL for published peer-reviewed articles from 1948 to 2011 that conceptualized, defined, or examined these terms. Two researchers independently reviewed each citation for inclusion and then extracted the concepts/definitions when available. Dictionaries/textbooks were also searched. Nine of 32 "SC/BSC," 25 of 182 "PC," and 12 of 42 "HC" articles focused on providing a conceptual framework/definition. Common concepts for all three terms were symptom control and quality-of-life for patients with life-limiting illness. "SC" focused more on patients on active treatment compared to other categories (9/9 vs. 8/37) and less often involved interdisciplinary care (4/9 vs. 31/37). In contrast, "HC" focused more on volunteers (6/12 vs. 6/34), bereavement care (9/12 vs. 7/34), and community care (9/12 vs. 6/34). Both "PC" and "SC/BSC" were applicable earlier in the disease trajectory (16/34 vs. 0/9). We found 13, 24, and 17 different definitions for "SC/BSC," "PC," and "HC," respectively. "SC/BSC" was the most variably defined, ranging from symptom management during cancer therapy to survivorship care. Dictionaries/textbooks showed similar findings. We identified defining concepts for "SC/BSC," "PC," and "HC" and developed a preliminary conceptual framework unifying these terms along the continuum of care to help build consensus toward standardized definitions.

  17. ECOTOURISM: DEFINITION AND CONCEPTS

    Directory of Open Access Journals (Sweden)

    Gheorghe CHEIA

    2013-07-01

    Full Text Available This paper takes into consideration some theoretical notions about ecotourism, an important segment of the tourism phenomenon, and wants to place face-to-face some of the most important attempts to define it (from Ceballos-Lascurain to David Weaver and Yi-Yen Wu. An important role in understanding ecological tourism is understanding the impacts that it has had on various elements of human society, and in a holistic vision we can conclude that ecotourism should be actually a principle that leads / underpins the entire global phenomenon of tourism.

  18. A Phase II Comparative Study of Gross Tumor Volume Definition With or Without PET/CT Fusion in Dosimetric Planning for Non–Small-Cell Lung Cancer (NSCLC): Primary Analysis of Radiation Therapy Oncology Group (RTOG) 0515

    International Nuclear Information System (INIS)

    Bradley, Jeffrey; Bae, Kyounghwa; Choi, Noah; Forster, Ken; Siegel, Barry A.; Brunetti, Jacqueline; Purdy, James; Faria, Sergio; Vu, Toni; Thorstad, Wade; Choy, Hak

    2012-01-01

    Background: Radiation Therapy Oncology Group (RTOG) 0515 is a Phase II prospective trial designed to quantify the impact of positron emission tomography (PET)/computed tomography (CT) compared with CT alone on radiation treatment plans (RTPs) and to determine the rate of elective nodal failure for PET/CT-derived volumes. Methods: Each enrolled patient underwent definitive radiation therapy for non–small-cell lung cancer (≥60 Gy) and had two RTP datasets generated: gross tumor volume (GTV) derived with CT alone and with PET/CT. Patients received treatment using the PET/CT-derived plan. The primary end point, the impact of PET/CT fusion on treatment plans was measured by differences of the following variables for each patient: GTV, number of involved nodes, nodal station, mean lung dose (MLD), volume of lung exceeding 20 Gy (V20), and mean esophageal dose (MED). Regional failure rate was a secondary end point. The nonparametric Wilcoxon matched-pairs signed-ranks test was used with Bonferroni adjustment for an overall significance level of 0.05. Results: RTOG 0515 accrued 52 patients, 47 of whom are evaluable. The follow-up time for all patients is 12.9 months (2.7–22.2). Tumor staging was as follows: II = 6%; IIIA = 40%; and IIIB = 54%. The GTV was statistically significantly smaller for PET/CT-derived volumes (98.7 vs. 86.2 mL; p < 0.0001). MLDs for PET/CT plans were slightly lower (19 vs. 17.8 Gy; p = 0.06). There was no significant difference in the number of involved nodes (2.1 vs. 2.4), V20 (32% vs. 30.8%), or MED (28.7 vs. 27.1 Gy). Nodal contours were altered by PET/CT for 51% of patients. One patient (2%) has developed an elective nodal failure. Conclusions: PET/CT-derived tumor volumes were smaller than those derived by CT alone. PET/CT changed nodal GTV contours in 51% of patients. The elective nodal failure rate for GTVs derived by PET/CT is quite low, supporting the RTOG standard of limiting the target volume to the primary tumor and involved nodes.

  19. Prostate bed target interfractional motion using RTOG consensus definitions and daily CT on rails. Does target motion differ between superior and inferior portions of the clinical target volume

    International Nuclear Information System (INIS)

    Verma, Vivek; Zhou, Sumin; Enke, Charles A.; Wahl, Andrew O.; Chen, Shifeng

    2017-01-01

    Using high-quality CT-on-rails imaging, the daily motion of the prostate bed clinical target volume (PB-CTV) based on consensus Radiation Therapy Oncology Group (RTOG) definitions (instead of surgical clips/fiducials) was studied. It was assessed whether PB motion in the superior portion of PB-CTV (SUP-CTV) differed from the inferior PB-CTV (INF-CTV). Eight pT2-3bN0-1M0 patients underwent postprostatectomy intensity-modulated radiotherapy, totaling 300 fractions. INF-CTV and SUP-CTV were defined as PB-CTV located inferior and superior to the superior border of the pubic symphysis, respectively. Daily pretreatment CT-on-rails images were compared to the planning CT in the left-right (LR), superoinferior (SI), and anteroposterior (AP) directions. Two parameters were defined: ''total PB-CTV motion'' represented total shifts from skin tattoos to RTOG-defined anatomic areas; ''PB-CTV target motion'' (performed for both SUP-CTV and INF-CTV) represented shifts from bone to RTOG-defined anatomic areas (i. e., subtracting shifts from skin tattoos to bone). Mean (± standard deviation, SD) total PB-CTV motion was -1.5 (± 6.0), 1.3 (± 4.5), and 3.7 (± 5.7) mm in LR, SI, and AP directions, respectively. Mean (± SD) PB-CTV target motion was 0.2 (±1.4), 0.3 (±2.4), and 0 (±3.1) mm in the LR, SI, and AP directions, respectively. Mean (± SD) INF-CTV target motion was 0.1 (± 2.8), 0.5 (± 2.2), and 0.2 (± 2.5) mm, and SUP-CTV target motion was 0.3 (± 1.8), 0.5 (± 2.3), and 0 (± 5.0) mm in LR, SI, and AP directions, respectively. No statistically significant differences between INF-CTV and SUP-CTV motion were present in any direction. There are no statistically apparent motion differences between SUP-CTV and INF-CTV. Current uniform planning target volume (PTV) margins are adequate to cover both portions of the CTV. (orig.) [de

  20. Locoregional recurrence of rectal carcinoma. A CT-analysis and a target volume concept in adjuvant radiotherapy

    International Nuclear Information System (INIS)

    Bagatzounis, A.; Koelbl, O.; Mueller, G.; Oppitz, U.; Willner, J.; Flentje, M.

    1997-01-01

    Patients and method: 155 patients with the diagnosis of rectal carcinoma recurrences were treated in our institution between 1980 and 1995. To determine the extension of the recurrent tumor within the pelvic levels (praesacral levels S1-S5, precoccygeal-, pelvic floor level and perineal level) and the tumor infiltration of pelvic organs and muscles we analysed the pretherapeutic CT-images. The lymphnode recurrences were classified as: Pararectal-, presacral-, iliac internal-, iliac external-, iliac communis- and paraaortal recurrences. Results: Sixty-one percent of the patients with rectum exstirpation and 66% with anterior resection showed a combined local and nodal recurrence. Isolated lymph node recurrences were rare (4% and 5%). The local recurrence was mostly situated in the presacral pelvis, predominantly there was an infiltration of the presacral space at the level of S4, S5 and os coccygis regardless of the operating method and the primary tumor location. The anastomosis was involved in the tumor recurrence in 93% of the anteriorly resected patients. In 9 out of 96 patients after rectum exstirpation the pelvic region caudal of the tip of the coccyx was the origin of the recurrent tumor. Primarily all 9 patients had a deep-seated carcinoma ( [de

  1. Concept Design of Trailor Ferry Service to Carry 150 Trailers Between Jacksonville, FL and Bridgeport, CT of USA

    Science.gov (United States)

    Sindagi, S. C.; Sandhu, B. S.

    2015-04-01

    With the increased load on highways, today there is a need to develop alternate ways to transport goods within the sovereignty. The use of ships to transport goods has always been the primary method of transporting goods across the seas but it can also be used to transport goods within the country. This way we can reduce the load on highways which at this point of time serve as the primary method of transportation. Worldwide very few ferries are in operation which transports 100-150 Trailers between two ports. Catching on this opportunity for design, construction and operation of vessels, a survey for possible routes in United States of America which will transport 150 Trailers has been conducted by various authorities and organizations. The challenge here is to determine the parameters of the vessel and design a fleet of vessels that could carry trailers along with their tractors within the least possible time and in with least possible freight between Jacksonville, FL and Bridgeport, CT of United States of America. The primary aim of the work presented here is to propose a design with fleet in such a way that each day 150 trailers could be loaded and unloaded at each of the two mentioned ports. An analysis of the route between the ports brought out various primary parameters like the distance, weather, different load lines to be encountered and also several size constraints that the vessel needs to adhere to, in order to ply smoothly on this route. The vessel is designed as per the Guidelines for ships operating in international waters. The economic analysis of the project was performed spanning over 20 years and the best freight was found out which would be most profitable for the company as well as be a good value for money for the customers.

  2. Evaluation of an improved technique for lumen path definition and lumen segmentation of atherosclerotic vessels in CT angiography.

    Science.gov (United States)

    van Velsen, Evert F S; Niessen, Wiro J; de Weert, Thomas T; de Monyé, Cécile; van der Lugt, Aad; Meijering, Erik; Stokking, Rik

    2007-07-01

    Vessel image analysis is crucial when considering therapeutical options for (cardio-) vascular diseases. Our method, VAMPIRE (Vascular Analysis using Multiscale Paths Inferred from Ridges and Edges), involves two parts: a user defines a start- and endpoint upon which a lumen path is automatically defined, and which is used for initialization; the automatic segmentation of the vessel lumen on computed tomographic angiography (CTA) images. Both parts are based on the detection of vessel-like structures by analyzing intensity, edge, and ridge information. A multi-observer evaluation study was performed to compare VAMPIRE with a conventional method on the CTA data of 15 patients with carotid artery stenosis. In addition to the start- and endpoint, the two radiologists required on average 2.5 (SD: 1.9) additional points to define a lumen path when using the conventional method, and 0.1 (SD: 0.3) when using VAMPIRE. The segmentation results were quantitatively evaluated using Similarity Indices, which were slightly lower between VAMPIRE and the two radiologists (respectively 0.90 and 0.88) compared with the Similarity Index between the radiologists (0.92). The evaluation shows that the improved definition of a lumen path requires minimal user interaction, and that using this path as initialization leads to good automatic lumen segmentation results.

  3. Evaluation of an improved technique for lumen path definition and lumen segmentation of atherosclerotic vessels in CT angiography

    International Nuclear Information System (INIS)

    Velsen, Evert F.S. van; Niessen, Wiro J.; Meijering, Erik; Stokking, Rik; Weert, Thomas T. de; Monye, Cecile de; Lugt, Aad van der

    2007-01-01

    Vessel image analysis is crucial when considering therapeutical options for (cardio-) vascular diseases. Our method, VAMPIRE (Vascular Analysis using Multiscale Paths Inferred from Ridges and Edges), involves two parts: a user defines a start- and endpoint upon which a lumen path is automatically defined, and which is used for initialization; the automatic segmentation of the vessel lumen on computed tomographic angiography (CTA) images. Both parts are based on the detection of vessel-like structures by analyzing intensity, edge, and ridge information. A multi-observer evaluation study was performed to compare VAMPIRE with a conventional method on the CTA data of 15 patients with carotid artery stenosis. In addition to the start- and endpoint, the two radiologists required on average 2.5 (SD: 1.9) additional points to define a lumen path when using the conventional method, and 0.1 (SD: 0.3) when using VAMPIRE. The segmentation results were quantitatively evaluated using Similarity Indices, which were slightly lower between VAMPIRE and the two radiologists (respectively 0.90 and 0.88) compared with the Similarity Index between the radiologists (0.92). The evaluation shows that the improved definition of a lumen path requires minimal user interaction, and that using this path as initialization leads to good automatic lumen segmentation results. (orig.)

  4. First-in-Human PET/CT Imaging of Metastatic Neuroendocrine Neoplasms with Cyclotron-Produced 44Sc-DOTATOC: A Proof-of-Concept Study.

    Science.gov (United States)

    Singh, Aviral; van der Meulen, Nicholas P; Müller, Cristina; Klette, Ingo; Kulkarni, Harshad R; Türler, Andreas; Schibli, Roger; Baum, Richard P

    2017-05-01

    44 Sc is a promising positron emission tomography (PET) radionuclide (T 1/2  = 4.04 hours, E β+average  = 632 keV) and can be made available, using a cyclotron production route, in substantial quantities as a highly pure product. Herein, the authors report on a first-in-human PET/CT study using 44 Sc-DOTATOC prepared with cyclotron-produced 44 Sc. The production of 44 Sc was carried out through the 44 Ca(p,n) 44 Sc nuclear reaction at Paul Scherrer Institut, Switzerland. After separation, 44 Sc was shipped to Zentralklinik Bad Berka, Germany, where radiolabeling was performed, yielding radiochemically pure 44 Sc-DOTATOC. Two patients, currently followed up after peptide receptor radionuclide therapy of metastatic neuroendocrine neoplasms, participated in this proof-of-concept study. Blood sampling was performed before and after application of 44 Sc-DOTATOC. PET/CT acquisitions, performed at different time points after injection of 44 Sc-DOTATOC, allowed detection of even very small lesions on delayed scans. No clinical adverse effects were observed and the laboratory hematological, renal, and hepatic profiles remained unchanged. In this study, cyclotron-produced 44 Sc was used in the clinic for the first time. It is attractive for theranostic application with 177 Lu, 90 Y, or 47 Sc as therapeutic counterparts. 44 Sc-based radiopharmaceuticals will be of particular value for PET facilities without radiopharmacy, to which they can be shipped from a centralized production site.

  5. Y-90 SPECT ML image reconstruction with a new model for tissue-dependent bremsstrahlung production using CT information: a proof-of-concept study

    Science.gov (United States)

    Lim, Hongki; Fessler, Jeffrey A.; Wilderman, Scott J.; Brooks, Allen F.; Dewaraja, Yuni K.

    2018-06-01

    While the yield of positrons used in Y-90 PET is independent of tissue media, Y-90 SPECT imaging is complicated by the tissue dependence of bremsstrahlung photon generation. The probability of bremsstrahlung production is proportional to the square of the atomic number of the medium. Hence, the same amount of activity in different tissue regions of the body will produce different numbers of bremsstrahlung photons. Existing reconstruction methods disregard this tissue-dependency, potentially impacting both qualitative and quantitative imaging of heterogeneous regions of the body such as bone with marrow cavities. In this proof-of-concept study, we propose a new maximum-likelihood method that incorporates bremsstrahlung generation probabilities into the system matrix, enabling images of the desired Y-90 distribution to be reconstructed instead of the ‘bremsstrahlung distribution’ that is obtained with existing methods. The tissue-dependent probabilities are generated by Monte Carlo simulation while bone volume fractions for each SPECT voxel are obtained from co-registered CT. First, we demonstrate the tissue dependency in a SPECT/CT imaging experiment with Y-90 in bone equivalent solution and water. Visually, the proposed reconstruction approach better matched the true image and the Y-90 PET image than the standard bremsstrahlung reconstruction approach. An XCAT phantom simulation including bone and marrow regions also demonstrated better agreement with the true image using the proposed reconstruction method. Quantitatively, compared with the standard reconstruction, the new method improved estimation of the liquid bone:water activity concentration ratio by 40% in the SPECT measurement and the cortical bone:marrow activity concentration ratio by 58% in the XCAT simulation.

  6. Standardizing terms, definitions and concepts for describing and interpreting unwanted immunogenicity of biopharmaceuticals: recommendations of the Innovative Medicines Initiative ABIRISK consortium.

    Science.gov (United States)

    Rup, B; Pallardy, M; Sikkema, D; Albert, T; Allez, M; Broet, P; Carini, C; Creeke, P; Davidson, J; De Vries, N; Finco, D; Fogdell-Hahn, A; Havrdova, E; Hincelin-Mery, A; C Holland, M; H Jensen, P E; Jury, E C; Kirby, H; Kramer, D; Lacroix-Desmazes, S; Legrand, J; Maggi, E; Maillère, B; Mariette, X; Mauri, C; Mikol, V; Mulleman, D; Oldenburg, J; Paintaud, G; R Pedersen, C; Ruperto, N; Seitz, R; Spindeldreher, S; Deisenhammer, F

    2015-09-01

    Biopharmaceuticals (BPs) represent a rapidly growing class of approved and investigational drug therapies that is contributing significantly to advancing treatment in multiple disease areas, including inflammatory and autoimmune diseases, genetic deficiencies and cancer. Unfortunately, unwanted immunogenic responses to BPs, in particular those affecting clinical safety or efficacy, remain among the most common negative effects associated with this important class of drugs. To manage and reduce risk of unwanted immunogenicity, diverse communities of clinicians, pharmaceutical industry and academic scientists are involved in: interpretation and management of clinical and biological outcomes of BP immunogenicity, improvement of methods for describing, predicting and mitigating immunogenicity risk and elucidation of underlying causes. Collaboration and alignment of efforts across these communities is made difficult due to lack of agreement on concepts, practices and standardized terms and definitions related to immunogenicity. The Innovative Medicines Initiative (IMI; www.imi-europe.org), ABIRISK consortium [Anti-Biopharmaceutical (BP) Immunization Prediction and Clinical Relevance to Reduce the Risk; www.abirisk.eu] was formed by leading clinicians, academic scientists and EFPIA (European Federation of Pharmaceutical Industries and Associations) members to elucidate underlying causes, improve methods for immunogenicity prediction and mitigation and establish common definitions around terms and concepts related to immunogenicity. These efforts are expected to facilitate broader collaborations and lead to new guidelines for managing immunogenicity. To support alignment, an overview of concepts behind the set of key terms and definitions adopted to date by ABIRISK is provided herein along with a link to access and download the ABIRISK terms and definitions and provide comments (http://www.abirisk.eu/index_t_and_d.asp). © 2015 British Society for Immunology.

  7. PET CT Thresholds for Radiotherapy Target Definition in Non-Small-Cell Lung Cancer: How Close are we to the Pathologic Findings?

    International Nuclear Information System (INIS)

    Wu Kailiang; Ung, Yee C.; Hornby, Jennifer

    2010-01-01

    Purpose: Optimal target delineation threshold values for positron emission tomography (PET) and computed tomography (CT) radiotherapy planning is controversial. In this present study, different PET CT threshold values were used for target delineation and then compared pathologically. Methods and Materials: A total of 31 non-small-cell lung cancer patients underwent PET CT before surgery. The maximal diameter (MD) of the pathologic primary tumor was obtained. The CT-based gross tumor volumes (GTV CT ) were delineated for CT window-level thresholds at 1,600 and -300 Hounsfield units (HU) (GTV CT1 ); 1,600 and -400 (GTV CT2 ); 1,600 and -450 HU (GTV CT3 ); 1,600 and -600 HU (GTV CT4 ); 1,200 and -700 HU (GTV CT5 ); 900 and -450 HU (GTV CT6 ); and 700 and -450 HU (GTV CT7 ). The PET-based GTVs (GTV PET ) were autocontoured at 20% (GTV 20 ), 30% (GTV 30 ), 40% (GTV 40 ), 45% (GTV 45 ), 50% (GTV 50 ), and 55% (GTV 55 ) of the maximal intensity level. The MD of each image-based GTV in three-dimensional orientation was determined. The MD of the GTV PET and GTV CT were compared with the pathologically determined MD. Results: The median MD of the GTV CT changed from 2.89 (GTV CT2 ) to 4.46 (GTV CT7 ) as the CT thresholds were varied. The correlation coefficient of the GTV CT compared with the pathologically determined MD ranged from 0.76 to 0.87. The correlation coefficient of the GTV CT1 was the best (r = 0.87). The median MD of GTV PET changed from 5.72cm to 2.67cm as the PET thresholds increased. The correlation coefficient of the GTV PET compared with the pathologic finding ranged from 0.51 to 0.77. The correlation coefficient of GTV 50 was the best (r = 0.77). Conclusion: Compared with the MD of GTV PET , the MD of GTV CT had better correlation with the pathologic MD. The GTV CT1 and GTV 50 had the best correlation with the pathologic results.

  8. Biofuel Drying - Literature Study and Definitions, Concepts and Terms; Torkning av biobraensle - litteraturstudie samt definitioner, begrepp och termer

    Energy Technology Data Exchange (ETDEWEB)

    Sanati, Mehri; Faghihi, Mostafa

    2001-09-01

    The report contains one section with definitions and explications of terms in the field of drying of biofuels. The second section presents, in english, the result of a literature study in the same subject, based on 90 literature references.

  9. The use of multi representative learning materials: definitive, macroscopic, microscopic, symbolic, and practice in analyzing students’ concept understanding

    Science.gov (United States)

    Susilaningsih, E.; Wulandari, C.; Supartono; Kasmui; Alighiri, D.

    2018-03-01

    This research aims to compose learning material which contains definitive macroscopic, microscopic and symbolic to analyze students’ conceptual understanding in acid-base learning materials. This research was conducted in eleven grade, natural science class, senior high school 1 (SMAN 1) Karangtengah, Demak province, Indonesia as the low level of students’ conceptual understanding and the high level of students’ misconception. The data collecting technique is by test to assess the cognitive aspect, questionnaire to assess students’ responses to multi representative learning materials (definitive, macroscopic, microscopic, symbolic), and observation to assess students’ macroscopic aspects. Three validators validate the multi-representative learning materials (definitive, macroscopic, microscopic, symbolic). The results of the research show that the multi-representative learning materials (definitive, macroscopic, microscopes, symbolic) being used is valid in the average score 62 of 75. The data is analyzed using the descriptive qualitative method. The results of the research show that 72.934 % students understand, 7.977 % less understand, 8.831 % do not understand, and 10.256 % misconception. In comparison, the second experiment class shows 54.970 % students understand, 5.263% less understand, 11.988 % do not understand, 27.777 % misconception. In conclusion, the application of multi representative learning materials (definitive, macroscopic, microscopic, symbolic) can be used to analyze the students’ understanding of acid-base materials.

  10. Differences in the definition of internal target volumes using slow CT alone or in combination with thin-slice CT under breath-holding conditions during the planning of stereotactic radiotherapy for lung cancer

    International Nuclear Information System (INIS)

    Seki, Satoshi; Kunieda, Etsuo; Takeda, Atsuya; Nagaoka, Tomoaki; Deloar, Hossain M.; Kawase, Takatsugu; Fukada, Junichi; Kawaguchi, Osamu; Uematsu, Minoru; Kubo, Atsushi

    2007-01-01

    Purpose: To investigate how the delineations of the internal target volume (ITV) made from 'slow' CT alter with reference to 'thin-slice' CT. Materials and methods: Thin-slice CT images taken under breath-holding conditions and slow CT images taken under shallow-breathing conditions (8 s/image) of 11 lung cancers were used for this study. Five radiation oncologists delineated ITV of the 11 lesions using slow CT images (ITV1), and then redefined them with reference to thin-slice CT images (ITV2). SD-images (standard deviation image) were created for all patients from ITV images in order to visualize the regional variation of the ITVs. Results: The mean value of ITV2 was smaller than that initially defined by ITV1. There was no significant change in ITV1 and ITV2 between operators with regard to standard deviation in volume. There was a significant difference in the distribution of the ratio of ITV1 to ITV2 obtained on thin-slice CTs between cases with and without ground glass opacity. In cases without ground glass opacity there was a tendency for ITV2 to have a smaller volume than ITV1. Conclusions: Combined use of slow CT and thin-slice CT in delineation of ITV contours appeared to be useful in making adjustments for obscured tumor images caused by respiratory movement

  11. Exploring Mathematical Definition Construction Processes

    Science.gov (United States)

    Ouvrier-Buffet, Cecile

    2006-01-01

    The definition of "definition" cannot be taken for granted. The problem has been treated from various angles in different journals. Among other questions raised on the subject we find: the notions of "concept definition" and "concept image", conceptions of mathematical definitions, redefinitions, and from a more axiomatic point of view, how to…

  12. Do SNOMED CT Relationships Qualify?

    NARCIS (Netherlands)

    Cornet, Ronald

    2008-01-01

    An important feature of SNOMED CT is post-coordination, which is enabled as SNOMED CT specifies refinability of target concepts of relationships. In this paper the use of refinable relationships in SNOMED CT is analysed, and the interplay between refinable and defining relationships. Refinability is

  13. Prostate bed target interfractional motion using RTOG consensus definitions and daily CT on rails. Does target motion differ between superior and inferior portions of the clinical target volume

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Vivek; Zhou, Sumin; Enke, Charles A.; Wahl, Andrew O. [University of Nebraska Medical Center, Department of Radiation Oncology, Omaha (United States); Chen, Shifeng [University of Maryland School of Medicine, Department of Radiation Oncology, Baltimore, MD (United States)

    2017-01-15

    Using high-quality CT-on-rails imaging, the daily motion of the prostate bed clinical target volume (PB-CTV) based on consensus Radiation Therapy Oncology Group (RTOG) definitions (instead of surgical clips/fiducials) was studied. It was assessed whether PB motion in the superior portion of PB-CTV (SUP-CTV) differed from the inferior PB-CTV (INF-CTV). Eight pT2-3bN0-1M0 patients underwent postprostatectomy intensity-modulated radiotherapy, totaling 300 fractions. INF-CTV and SUP-CTV were defined as PB-CTV located inferior and superior to the superior border of the pubic symphysis, respectively. Daily pretreatment CT-on-rails images were compared to the planning CT in the left-right (LR), superoinferior (SI), and anteroposterior (AP) directions. Two parameters were defined: ''total PB-CTV motion'' represented total shifts from skin tattoos to RTOG-defined anatomic areas; ''PB-CTV target motion'' (performed for both SUP-CTV and INF-CTV) represented shifts from bone to RTOG-defined anatomic areas (i. e., subtracting shifts from skin tattoos to bone). Mean (± standard deviation, SD) total PB-CTV motion was -1.5 (± 6.0), 1.3 (± 4.5), and 3.7 (± 5.7) mm in LR, SI, and AP directions, respectively. Mean (± SD) PB-CTV target motion was 0.2 (±1.4), 0.3 (±2.4), and 0 (±3.1) mm in the LR, SI, and AP directions, respectively. Mean (± SD) INF-CTV target motion was 0.1 (± 2.8), 0.5 (± 2.2), and 0.2 (± 2.5) mm, and SUP-CTV target motion was 0.3 (± 1.8), 0.5 (± 2.3), and 0 (± 5.0) mm in LR, SI, and AP directions, respectively. No statistically significant differences between INF-CTV and SUP-CTV motion were present in any direction. There are no statistically apparent motion differences between SUP-CTV and INF-CTV. Current uniform planning target volume (PTV) margins are adequate to cover both portions of the CTV. (orig.) [German] Zur Evaluation der interfraktionellen Variabilitaet des klinischen Zielvolumens der Prostataloge

  14. Cone beam CT imaging with limited angle of projections and prior knowledge for volumetric verification of non-coplanar beam radiation therapy: a proof of concept study

    Science.gov (United States)

    Meng, Bowen; Xing, Lei; Han, Bin; Koong, Albert; Chang, Daniel; Cheng, Jason; Li, Ruijiang

    2013-11-01

    Non-coplanar beams are important for treatment of both cranial and noncranial tumors. Treatment verification of such beams with couch rotation/kicks, however, is challenging, particularly for the application of cone beam CT (CBCT). In this situation, only limited and unconventional imaging angles are feasible to avoid collision between the gantry, couch, patient, and on-board imaging system. The purpose of this work is to develop a CBCT verification strategy for patients undergoing non-coplanar radiation therapy. We propose an image reconstruction scheme that integrates a prior image constrained compressed sensing (PICCS) technique with image registration. Planning CT or CBCT acquired at the neutral position is rotated and translated according to the nominal couch rotation/translation to serve as the initial prior image. Here, the nominal couch movement is chosen to have a rotational error of 5° and translational error of 8 mm from the ground truth in one or more axes or directions. The proposed reconstruction scheme alternates between two major steps. First, an image is reconstructed using the PICCS technique implemented with total-variation minimization and simultaneous algebraic reconstruction. Second, the rotational/translational setup errors are corrected and the prior image is updated by applying rigid image registration between the reconstructed image and the previous prior image. The PICCS algorithm and rigid image registration are alternated iteratively until the registration results fall below a predetermined threshold. The proposed reconstruction algorithm is evaluated with an anthropomorphic digital phantom and physical head phantom. The proposed algorithm provides useful volumetric images for patient setup using projections with an angular range as small as 60°. It reduced the translational setup errors from 8 mm to generally <1 mm and the rotational setup errors from 5° to <1°. Compared with the PICCS algorithm alone, the integration of rigid

  15. The language of science and the high school student: The recognition of concept definitions: A comparison between hindi speaking students in India and english speaking students in Australia

    Science.gov (United States)

    Lynch, P. P.; Chipman, H. H.; Pachaury, A. C.

    Sixteen concept words (mass, length, area, volume, solid, liquid, gas, element, compound, mixture, electron, proton, neutron, atom, molecule, and ion) associated with the theme, the nature of matter were described as simple text book definitions after examination of classroom notes and school texts of the last three decades. Sixteen multiple-choice items all of the same form were constructed for each of the concept definitions. The English version of the sixteen item test was given to 1635 high school students in Tasmania (where the language of instruction and the home language is English) and the Hindi version of the test was given to 826 students from the Bhopal/Barwani region of India where the medium of instruction is Hindi. The English and Hindi speaking data are compared from the point of view of development, performance for individual items, and overall performance at grade 10. A number of linguistic hypotheses are examined and reported upon. Although the overall score at grade 10 was identical (10.8/16) for both groups there are differences in development overall and for individual items which are of interest. Overall, the science specificity of the Hindi words does not appear to confer any clearly defined advantage or disadvantage though again there are some interesting individual anomolies.

  16. Concept definition and aerodynamic technology studies for single-engine V/STOL fighter/attack aircraft

    Science.gov (United States)

    Nelms, W. P.; Durston, D. A.

    1981-01-01

    The results obtained in the early stages of a research program to develop aerodynamic technology for single-engine V/STOL fighter/attack aircraft projected for the post-1990 period are summarized. This program includes industry studies jointly sponsored by NASA and the Navy. Four contractors have identified promising concepts featuring a variety of approaches for providing propulsive lift. Vertical takeoff gross weights range from about 10,000 to 13,600 kg (22,000 to 30,000 lb). The aircraft have supersonic capability, are highly maneuverable, and have significant short takeoff overload capability. The contractors have estimated the aerodynamics and identified aerodynamic uncertainties associated with their concepts. Wind-tunnel research programs will be formulated to investigate these uncertainties. A description of the concepts is emphasized.

  17. Comparative evaluation of CT-based and respiratory-gated PET/CT-based planning target volume (PTV) in the definition of radiation treatment planning in lung cancer: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Luca; Elisei, Federica [San Gerardo Hospital, Nuclear Medicine, Monza (Italy); Meregalli, Sofia; Niespolo, Rita [San Gerardo Hospital, Radiotherapy, Monza (Italy); Zorz, Alessandra; De Ponti, Elena; Morzenti, Sabrina; Crespi, Andrea [San Gerardo Hospital, Medical Physics, Monza (Italy); Brenna, Sarah [University of Milan-Bicocca, School of Radiation Oncology, Monza (Italy); Gardani, Gianstefano [San Gerardo Hospital, Radiotherapy, Monza (Italy); University of Milan-Bicocca, Milan (Italy); Messa, Cristina [San Gerardo Hospital, Nuclear Medicine, Monza (Italy); University of Milan-Bicocca, Tecnomed Foundation, Milan (Italy); National Research Council, Institute for Bioimaging and Molecular Physiology, Milan (Italy)

    2014-04-15

    The aim of this study was to compare planning target volume (PTV) defined on respiratory-gated positron emission tomography (PET)/CT (RG-PET/CT) to PTV based on ungated free-breathing CT and to evaluate if RG-PET/CT can be useful to personalize PTV by tailoring the target volume to the lesion motion in lung cancer patients. Thirteen lung cancer patients (six men, mean age 70.0 years, 1 small cell lung cancer, 12 non-small cell lung cancer) who were candidates for radiation therapy were prospectively enrolled and submitted to RG-PET/CT. Ungated free-breathing CT images obtained during a PET/CT study were visually contoured by the radiation oncologist to define standard clinical target volumes (CTV1). Standard PTV (PTV1) resulted from CTV1 with the addition of 1-cm expansion of margins in all directions. RG-PET/CT images were contoured by the nuclear medicine physician and radiation oncologist according to a standardized institutional protocol for contouring gated images. Each CT and PET image of the patient's respiratory cycle phases was contoured to obtain the RG-CT-based CTV (CTV2) and the RG-PET/CT-based CTV (CTV3), respectively. RG-CT-based and RG-PET/CT-based PTV (PTV2 and PTV3, respectively) were then derived from gated CTVs with a margin expansion of 7-8 mm in head to feet direction and 5 mm in anterior to posterior and left to right direction. The portions of gated PTV2 and PTV3 geometrically not encompassed in PTV1 (PTV2 out PTV1 and PTV3 out PTV1) were also calculated. Mean ± SD CTV1, CTV2 and CTV3 were 30.5 ± 33.2, 43.1 ± 43.2 and 44.8 ± 45.2 ml, respectively. CTV1 was significantly smaller than CTV2 and CTV3 (p = 0.017 and 0.009 with Student's t test, respectively). No significant difference was found between CTV2 and CTV3. Mean ± SD of PTV1, PTV2 and PTV3 were 118.7 ± 94.1, 93.8 ± 80.2 and 97.0 ± 83.9 ml, respectively. PTV1 was significantly larger than PTV2 and PTV3 (p = 0.038 and 0.043 with Student's t test, respectively). No

  18. Body packers on your examination table: How helpful are plain x-ray images? A definitive low-dose CT protocol as a diagnosis tool for body packers.

    Science.gov (United States)

    Schulz, B; Grossbach, A; Gruber-Rouh, T; Zangos, S; Vogl, Th J; Eichler, K

    2014-12-01

    To analyze the clinical value and radiation dose of plain x-rays and CT in examining patients suspected of ingesting drug-filled packets. Thirty-eight patients with suspected internal concealment of drug-filled packets who were examined with plain x-rays or CT or both were included in the study. CT studies were performed using low-dose and standard-dose techniques. All radiographic images were analysed by two radiologists regarding identification of the packets and estimating the effective radiation dose from standard- and low-dose CT versus conventional x-ray examinations. Descriptive calculations were made regarding the number and density of packs and radiation dosage. The diagnostic performance of both radiologists with standard- and low-dose CT was calculated by analysing differences in the mean number of packs found. Thirty-one patients were positively identified as body packers with an average of 13 packs (min: n = 1, max: n = 58, total: n = 390); seven patients were not concealing drug packets. X-ray images were taken of 24 patients prior to CT, thus allowing a direct comparison between the two methods. The correct diagnosis was made in 42%, in 33% the radiologists were uncertain, and in 25% of drug packets were either not or wrongly identified. X-ray imaging had a positive predictive value of 20% with a negative predictive value of 81%. A total of 55 CT examinations were performed on all patients with a mean effective dose of 2 mSv (low dose) versus 9.3 mSv (standard dose). The visibility of packets on low-dose CT images compared to high-dose CT was not reduced: the radiologists identified 385 and 381 of the packets, respectively, with no difference regarding the examination technique (p = 0.24 and p = 0.253, respectively). The radiodensity of all drug-filled packets at CT ranged from 26-292 HU (mean 181.2 HU). X-ray imaging of supposed body packers leads to a significant risk of diagnostic errors and additional need for CT. Instead, a single abdominal low

  19. Large Deployable Reflector (LDR) system concept and technology definition study. Volume 2: Technology assessment and technology development plan

    Science.gov (United States)

    Agnew, Donald L.; Jones, Peter A.

    1989-01-01

    A study was conducted to define reasonable and representative LDR system concepts for the purpose of defining a technology development program aimed at providing the requisite technological capability necessary to start LDR development by the end of 1991. This volume presents thirteen technology assessments and technology development plans, as well as an overview and summary of the LDR concepts. Twenty-two proposed augmentation projects are described (selected from more than 30 candidates). The five LDR technology areas most in need of supplementary support are: cryogenic cooling; astronaut assembly of the optically precise LDR in space; active segmented primary mirror; dynamic structural control; and primary mirror contamination control. Three broad, time-phased, five-year programs were synthesized from the 22 projects, scheduled, and funding requirements estimated.

  20. Assessment of a new trauma workflow concept implementing a sliding CT scanner in the trauma room: the effect on workup times

    NARCIS (Netherlands)

    Fung Kon Jin, P. H. Ping; Goslings, J. Carel; Ponsen, Kees Jan; van Kuijk, Cees; Hoogerwerf, Nico; Luitse, Jan S.

    2008-01-01

    INTRODUCTION: We developed a new shockroom resuscitation setting that includes a moveable, multislice computed tomography (CT) scanner capable of scanning patients during the initial trauma resuscitation phase without (multiple) patient transfers that previously were necessary. This enables us to

  1. Body packers on your examination table: How helpful are plain x-ray images? A definitive low-dose CT protocol as a diagnosis tool for body packers

    International Nuclear Information System (INIS)

    Schulz, B.; Grossbach, A.; Gruber-Rouh, T.; Zangos, S.; Vogl, Th. J.; Eichler, K.

    2014-01-01

    Aim: To analyze the clinical value and radiation dose of plain x-rays and CT in examining patients suspected of ingesting drug-filled packets. Materials and methods: Thirty-eight patients with suspected internal concealment of drug-filled packets who were examined with plain x-rays or CT or both were included in the study. CT studies were performed using low-dose and standard-dose techniques. All radiographic images were analysed by two radiologists regarding identification of the packets and estimating the effective radiation dose from standard- and low-dose CT versus conventional x-ray examinations. Descriptive calculations were made regarding the number and density of packs and radiation dosage. The diagnostic performance of both radiologists with standard- and low-dose CT was calculated by analysing differences in the mean number of packs found. Results: Thirty-one patients were positively identified as body packers with an average of 13 packs (min: n = 1, max: n = 58, total: n = 390); seven patients were not concealing drug packets. X-ray images were taken of 24 patients prior to CT, thus allowing a direct comparison between the two methods. The correct diagnosis was made in 42%, in 33% the radiologists were uncertain, and in 25% of drug packets were either not or wrongly identified. X-ray imaging had a positive predictive value of 20% with a negative predictive value of 81%. A total of 55 CT examinations were performed on all patients with a mean effective dose of 2 mSv (low dose) versus 9.3 mSv (standard dose). The visibility of packets on low-dose CT images compared to high-dose CT was not reduced: the radiologists identified 385 and 381 of the packets, respectively, with no difference regarding the examination technique (p = 0.24 and p = 0.253, respectively). The radiodensity of all drug-filled packets at CT ranged from 26–292 HU (mean 181.2 HU). Conclusion: X-ray imaging of supposed body packers leads to a significant risk of diagnostic

  2. SU-F-J-223: Patterns of Failure for Laryngeal Cancer Patients Treated with Definitive IMRT: Comparing Two Different Methods for Determining the Origin of Recurrence From Follow-Up PET/CT Scans

    Energy Technology Data Exchange (ETDEWEB)

    Brodin, P; Guha, C; Tome, W [Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York (United States); Kabarriti, R; Kalnicki, S; Garg, M [Montefiore Medical Center, Bronx, New York (United States); Vogelius, I [Rigshospitalet, Copenhagen University Hospital, Copenhagen (Denmark)

    2016-06-15

    Purpose: To determine patterns of failure in laryngeal cancer treated with definitive IMRT by comparing two different methods for identifying the recurrence epicenter on follow-up PET/CT. Methods: We identified 20 patients treated for laryngeal squamous cell carcinoma with definitive IMRT who had loco-regional recurrence diagnosed on PET/CT. Recurrence PET/CT scans were co-registered with the original treatment planning CT using deformable image registration with the VoxAlign deformation engine in MIM Software. Recurrence volumes were delineated on co-registered follow-up scans using a semi-automatic PETedge tool and two separate methods were used to identify the recurrence point of origin: a) Finding the point within the recurrence volume for which the maximum distance to the surface of the surrounding recurrence volume is smaller than for any other point. b) Finding the point within the recurrence volume with the maximum standardized uptake value (SUVmax), without geometric restrictions.For each method the failure pattern was determined as whether the recurrence origin fell within the original high-dose target volumes GTV70, CTV70, PTV70 (receiving 70Gy), intermediate-risk PTV59 (receiving 59.4Gy) or low-risk PTV54 (receiving 54.1Gy), in the original treatment planning CT. Results: 23 primary/nodal recurrences from the 20 patients were analyzed. The three-dimensional distance between the two different origins was on average 10.5mm (std.dev. 10mm). Most recurrences originated in the high-dose target volumes for both methods with 13 (57%) and 11 (48%) in the GTV70 and 20 (87%) and 20 (87%) in the PTV70 for method a) and b), respectively. There was good agreement between the two methods in classifying the origin target volumes with 69% concordance for GTV70, 89% for CTV70 and 100% for PTV70. Conclusion: With strong agreement in patterns of failure between two separate methods for determining recurrence origin, we conclude that most recurrences occurred within the

  3. Reperfusion is a more accurate predictor of follow-up infarct volume than recanalization: a proof of concept using CT in acute ischemic stroke patients.

    Science.gov (United States)

    Soares, Bruno P; Tong, Elizabeth; Hom, Jason; Cheng, Su-Chun; Bredno, Joerg; Boussel, Loic; Smith, Wade S; Wintermark, Max

    2010-01-01

    The purpose of this study was to compare recanalization and reperfusion in terms of their predictive value for imaging outcomes (follow-up infarct volume, infarct growth, salvaged penumbra) and clinical outcome in acute ischemic stroke patients. Twenty-two patients admitted within 6 hours of stroke onset were retrospectively included in this study. These patients underwent a first stroke CT protocol including CT-angiography (CTA) and perfusion-CT (PCT) on admission, and similar imaging after treatment, typically around 24 hours, to assess recanalization and reperfusion. Recanalization was assessed by comparing arterial patency on admission and posttreatment CTAs; reperfusion, by comparing the volumes of CBV, CBF, and MTT abnormality on admission and posttreatment PCTs. Collateral flow was graded on the admission CTA. Follow-up infarct volume was measured on the discharge noncontrast CT. The groups of patients with reperfusion, no reperfusion, recanalization, and no recanalization were compared in terms of imaging and clinical outcomes. Reperfusion (using an MTT reperfusion index >75%) was a more accurate predictor of follow-up infarct volume than recanalization. Collateral flow and recanalization were not accurate predictors of follow-up infarct volume. An interaction term was found between reperfusion and the volume of the admission penumbra >50 mL. Our study provides evidence that reperfusion is a more accurate predictor of follow-up infarct volume in acute ischemic stroke patients than recanalization. We recommend an MTT reperfusion index >75% to assess therapy efficacy in future acute ischemic stroke trials that use perfusion-CT.

  4. Satellite Power Systems (SPS) concept definition study. Volume 5: Special emphasis studies. [rectenna and solar power satellite design studies

    Science.gov (United States)

    Hanley, G. M.

    1980-01-01

    Satellite configurations based on the Satellite Power System baseline requirements were analyzed and a preferred concept selected. A satellite construction base was defined, precursor operations incident to establishment of orbital support facilities identified, and the satellite construction sequence and procedures developed. Rectenna construction requirement were also addressed. Mass flow to orbit requirements were revised and traffic models established based on construction of 60 instead of 120 satellites. Analyses were conducted to determine satellite control, resources, manufacturing, and propellant requirements. The impact of the laser beam used for space-to-Earth power transmission upon the intervening atmosphere was examined as well as the inverse effect. The significant space environments and their effects on spacecraft components were investigated to define the design and operational limits imposed by the environments on an orbit transfer vehicle. The results show that LEO altitude 300 nmi and transfer orbit duration 6 months are preferrable.

  5. CT findings at the primary site of oropharyngeal squamous cell carcinoma within 6-8 weeks after definitive radiotherapy as predictors of primary site control

    International Nuclear Information System (INIS)

    Ojiri, Hiroya; Mendenhall, William M.; Mancuso, Anthony A.

    2002-01-01

    Purpose: To determine whether findings on CT studies, done 6 weeks after radiotherapy (RT), can predict the likelihood of ultimate control at the primary site in oropharyngeal carcinoma. Methods and Materials: Forty-six patients with oropharyngeal squamous cell carcinoma underwent RT with curative intent. A minimal 2-year clinical follow-up after RT was required. The primary site CT findings were graded for risk of recurrence on a modified 3-point scale as follows: Grade 0, no detectable focal abnormalities; Grade 1, anatomic asymmetry or focal mass 10 mm (2a) or 10 mm at the primary site, the likelihood of local control is high (93%). The study results indicate that CT findings, based on this relatively small series, may not add incremental information beyond that of clinical examination for predicting local control but may be useful as a baseline if imaging surveillance is contemplated

  6. PET/CT and radiotherapy

    International Nuclear Information System (INIS)

    Messa, C.; CNR, Milano; S. Gerardo Hospital, Monza; Di Muzio, N.; Picchio, M.; Bettinardi, V.; Gilardi, M.C.; CNR, Milano; San Raffaele Scientific Institute, Milano; Fazio, F.; CNR, Milano; San Raffaele Scientific Institute, Milano; San Raffaele Scientific Institute, Milano

    2006-01-01

    This article reviews the state of the art of PET/CT applications in radiotherapy, specifically its use in disease staging, patient selection, treatment planning and treatment evaluation. Diseases for which radiotherapy with radical intent is indicated will be considered, as well as those in which PET/CT may actually change the course of disease. The methodological and technological aspects of PET/CT in radiotherapy are discussed, focusing on the problem of target volume definition with CT and PET functional imaging and the problem of tumor motion with respect to imaging and dose delivery

  7. CT after transsphenoidal surgery

    International Nuclear Information System (INIS)

    Tazawa, Satoru

    1991-01-01

    Two hundred and ten CT studies of 95 patients after transsphenoidal surgery were reviewed. Spheno-ethmoid opacificaiton, intrasellar hematoma and gas bubbles were noted within 2 weeks after surgery. Bone defect of the sellar floor and bone stent were seen on coronal scans in most cases. The packing material frequently disappeared on follow-up studies. Hormonal assessment of the functioning tumor, according to which the effect of treatment was evaluated, was correlated with CT findings. Because differentiation between postoperative changes and residual mass was difficult, there was no definite CT criteria to indicate residual functioning tumor except upward convexity of the diaphragma sellae on CT more than 3 months after surgery. Initial follow up CT study is recommended to be performed at about 3 months after surgery, at which time the immediate postoperative inflammatory changes have been disappeared. The incidence of recurrence was 3/47 (6%), which was shown on follow-up CT from 4 to 10 years after surgery. Therefore, subsequent CT study should be done in every year or two, taking the clinical symptoms and hormonal data into consideration. (author)

  8. CT after transsphenoidal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Tazawa, Satoru [Tohoku Univ., Sendai (Japan). School of Medicine

    1991-03-01

    Two hundred and ten CT studies of 95 patients after transsphenoidal surgery were reviewed. Spheno-ethmoid opacificaiton, intrasellar hematoma and gas bubbles were noted within 2 weeks after surgery. Bone defect of the sellar floor and bone stent were seen on coronal scans in most cases. The packing material frequently disappeared on follow-up studies. Hormonal assessment of the functioning tumor, according to which the effect of treatment was evaluated, was correlated with CT findings. Because differentiation between postoperative changes and residual mass was difficult, there was no definite CT criteria to indicate residual functioning tumor except upward convexity of the diaphragma sellae on CT more than 3 months after surgery. Initial follow up CT study is recommended to be performed at about 3 months after surgery, at which time the immediate postoperative inflammatory changes have been disappeared. The incidence of recurrence was 3/47 (6%), which was shown on follow-up CT from 4 to 10 years after surgery. Therefore, subsequent CT study should be done in every year or two, taking the clinical symptoms and hormonal data into consideration. (author).

  9. Definition of 1992 Technology Aircraft Noise Levels and the Methodology for Assessing Airplane Noise Impact of Component Noise Reduction Concepts

    Science.gov (United States)

    Kumasaka, Henry A.; Martinez, Michael M.; Weir, Donald S.

    1996-01-01

    This report describes the methodology for assessing the impact of component noise reduction on total airplane system noise. The methodology is intended to be applied to the results of individual study elements of the NASA-Advanced Subsonic Technology (AST) Noise Reduction Program, which will address the development of noise reduction concepts for specific components. Program progress will be assessed in terms of noise reduction achieved, relative to baseline levels representative of 1992 technology airplane/engine design and performance. In this report, the 1992 technology reference levels are defined for assessment models based on four airplane sizes - an average business jet and three commercial transports: a small twin, a medium sized twin, and a large quad. Study results indicate that component changes defined as program final goals for nacelle treatment and engine/airframe source noise reduction would achieve from 6-7 EPNdB reduction of total airplane noise at FAR 36 Stage 3 noise certification conditions for all of the airplane noise assessment models.

  10. Role of research in the safety case of future reactor concepts definite needs, confirmatory areas, added value

    International Nuclear Information System (INIS)

    Timo, Okkonen; Juhani, Hyvarinen

    2002-01-01

    In this paper, we aim to describe the role(s) of research when assessing - and finally demonstrating - the safety of future reactor concepts. The term 'research' could be defined in quite a limited fashion, while in this paper, we will use it synonymously to all Research and Design (R and D) work. First, we will provide a top-down planning perspective by identifying the general set of safety factors related to new reactor projects; i.e., factors that have to be accounted for already in the safety case. The research needs can be based on such a set of safety factors and related challenges, and it is crucial that the research requirements remain reasonable. For this, suitable design choices have to be made, such that they limit the criticality of individual plant functions, related systems/ structures/components (SSC), and human actions. In this context, we will discuss the general ways of limiting excessive research needs. The critical plant functions and SSC, in their turn, will require a strong safety demonstration. Once major design decisions have been made according to the aforementioned lines, actual systems are designed, using available equipment or developing new. Research support is needed to establish the technological adequacy and confidence level of each decision at each design level; this is relatively easy where conventional technologies are used, but more challenging if novel technologies come into question. Maturity of technology also correlates strongly with the attainable certainty and qualification of analysis tools. Here, we will describe the general phases of R and D from exploratory work to safety demonstration, and also independent confirmation. We will also touch upon the roles of different actors - the vendor, the licensee and the regulator - as well as their strategies in attacking the above-mentioned safety factors through research. (authors)

  11. CT findings of inoperable lung carcinoma

    International Nuclear Information System (INIS)

    Gay, S.B.; Black, W.C.

    1987-01-01

    CT is useful in the evaluation of patients with newly diagnosed or highly suspected lung cancer. The principal role of CT is to screen those patients with metastatic disease beyond the hili from an attempt at curative thoracotomy. While CT is regarded as very sensitive, it is not considered highly specific, and thus a surgical procedure is usually recommended for definitive diagnosis of most ''positive'' CT findings. However, the authors demonstrate a few characteristic CT findings that are highly predictive of unresectable metastatic disease. These CT findings include massive mediastinal lymphadenopathy, diffuse mediastinal infiltration, pericardial involvement, vascular encasement, and advanced chest wall invasion

  12. Mixed connective tissue disease associated with noted pulmonary CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Souji; Tsukada, Atsuko; Furuya, Tatsutaka

    1984-10-01

    CT was performed in a 56-year-old woman with mixed connective tissue disease (MCTD). Much more definitive pulmonary findings were obtained by CT than by the conventional chest x-ray examination and pulmonary function test. CT findings disclosed pulmonary lesions extremely similar to those in cases of progressive systemic sclerosis. Pulmonary CT was considered useful in examining pulmonary lesions for MCTD.

  13. Formal representation of complex SNOMED CT expressions

    Directory of Open Access Journals (Sweden)

    Markó Kornél

    2008-10-01

    Full Text Available Abstract Background Definitory expressions about clinical procedures, findings and diseases constitute a major benefit of a formally founded clinical reference terminology which is ontologically sound and suited for formal reasoning. SNOMED CT claims to support formal reasoning by description-logic based concept definitions. Methods On the basis of formal ontology criteria we analyze complex SNOMED CT concepts, such as "Concussion of Brain with(out Loss of Consciousness", using alternatively full first order logics and the description logic ℰℒ MathType@MTEF@5@5@+=feaagaart1ev2aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaWenfgDOvwBHrxAJfwnHbqeg0uy0HwzTfgDPnwy1aaceaGae8hmHuKae8NeHWeaaa@37B1@. Results Typical complex SNOMED CT concepts, including negations or not, can be expressed in full first-order logics. Negations cannot be properly expressed in the description logic ℰℒ MathType@MTEF@5@5@+=feaagaart1ev2aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaWenfgDOvwBHrxAJfwnHbqeg0uy0HwzTfgDPnwy1aaceaGae8hmHuKae8NeHWeaaa@37B1@ underlying SNOMED CT. All concepts concepts the meaning of which implies a temporal scope may be subject to diverging interpretations, which are often unclear in SNOMED CT as their contextual determinants are not made explicit. Conclusion The description of complex medical occurrents is ambiguous, as the same situations can be described as (i a complex occurrent C that has A and B as temporal parts, (ii a simple occurrent A' defined as a kind of A followed by some B, or (iii a simple occurrent B' defined as a kind of B preceded by some A. As negative statements in SNOMED CT cannot be exactly represented without

  14. CT findings of medulloblastoma

    International Nuclear Information System (INIS)

    Tsuchida, Tadashi; Fukuda, Mitsunori; Takeda, Norio; Tanaka, Ryuichi; Ito, Jusuke.

    1982-01-01

    Computed tomography (CT) of ten patients with medulloblastomas was evaluated. Six of them showed solid, nearly homogeneous lesions and a definite enhancement after the infusion of the contrast medium. However, 4 cases showed heterogenous mass lesions composed of areas of a low density and an iso- or slightly high density which was attenuated by contrast enhancement. Histological examinations revealed differentiated medulloblastomas in two of them, but the other two cases were typical medulloblastomas. It should be remembered that medulloblastomas can reveal heterogenous cerebellar midline mass lesions in CT scans. (author)

  15. Scope Definition

    DEFF Research Database (Denmark)

    Bjørn, Anders; Owsianiak, Mikołaj; Laurent, Alexis

    2018-01-01

    The scope definition is the second phase of an LCA. It determines what product systems are to be assessed and how this assessment should take place. This chapter teaches how to perform a scope definition. First, important terminology and key concepts of LCA are introduced. Then, the nine items...... making up a scope definition are elaborately explained: (1) Deliverables. (2) Object of assessment, (3) LCI modelling framework and handling of multifunctional processes, (4) System boundaries and completeness requirements, (5) Representativeness of LCI data, (6) Preparing the basis for the impact...... assessment, (7) Special requirements for system comparisons, (8) Critical review needs and (9) Planning reporting of results. The instructions relate both to the performance and reporting of a scope definition and are largely based on ILCD....

  16. Concept and development of measurement method of time sensitivity profile (TSP) in X-ray CT. Comparison of non-helical, single-slice helical, and multi-slice helical scans

    International Nuclear Information System (INIS)

    Tsujioka, Katsumi; Ida, Yoshihiro; Ohtsubo, Hironori; Takahashi, Yasukata; Niwa, Masayoshi

    2000-01-01

    We focused on the time element contained in a single CT image, and devised the concept of a time-sensitivity profile (TSP) describing how the time element is translated into an image. We calculated the data collection time range when the helical pitch is changed in non helical scans, single slice helical scans, and multi slice helical scans. We then calculated the time sensitivity profile (TSP) from the weighting applied when the data collection time range is translated into an image. TSP was also measured for each scanning method using our self-made moving phantom. TSPs obtained from the calculation and the experiments were very close. TSP showed interesting characteristics with each scanning method, especially in the case of multi slice helical scanning, in which TSP became shorter as helical pitch increased. We referred to the TSP's FWHM as the effective scanning time. When we conducted multi slice helical scanning at helical pitch 3, the effective scanning time increased to about 24% longer than that of a non helical scan. When we conducted multi slice helical scanning at helical pitch 5 or 6, the effective scanning time was about half that of a non helical scan. The time sensitivity profile (TSP) is a totally new concept that we consider an important element in discussing the time resolution of a CT scanner. The results of this review will provide significant data in determining the scanning parameters when scanning a moving object. (author)

  17. Impact of 18FDG-PET/CT on biological target volume (BTV) definition for treatment planning for non-small cell lung cancer patients

    International Nuclear Information System (INIS)

    Devic, Slobodan; Tomic, Nada; Faria, Sergio; Dean, Geoffrey; Lisbona, Robert; Parker, William; Kaufman, Chris; Podgorsak, Ervin B.

    2007-01-01

    This work represents our effort to test feasibility of FDG-based PET/CT on target volume delineation in radiotherapy treatment planning of NSCLC patients. Different methods have been developed to enable more precise target outlining using PET: Qualitative Visual Method, CTV=2.5 SUV units, linear SUV threshold function method, and CTV=40% Iso of Maximum Uptake Value. We are proposing reconstruction of three biological target volumes: necrotic BTV (same as PTV created by radiation oncologist using CT data), proliferating BTV (based on PET signal to background ratio 1:3) and hypoxic BTV (based on PET signal to background ratio of 1:19). Two IMRT plans were created and compared to the conventional treatment plan: 'conservative' IMRT plan delivers 52.5 Gy to the necrotic BTV and 65 Gy to the hypoxic BTV; 'radical' IMRT plan delivers 30 Gy to necrotic BTV, 52.5 Gy to proliferating BTV and 65 Gy to hypoxic BTV. Use of BTVs in IMRT plans is attractive because it increases dose to targets considered to need higher doses. It reduces considerably dose to heart and spinal cord, organs considered to limit dose escalation approaches in NSCLC treatment. 'Conservative' IMRT approach can be understood as a PET/CT-based concomitant boost to the tumor expressing the highest FDG uptake. 'Radical' plan implies deviation from the traditional uniform dose target coverage approach, with the intention of achieving better surrounding tissue sparing and ultimately allowing for dose escalation protocols relying on biologically based treatment planning

  18. Head trauma and CT

    International Nuclear Information System (INIS)

    Samejima, Kanji; Yoshii, Nobuo; Tobari, Chitoshi

    1979-01-01

    It has been said that chronic subdural hematoma cannot be diagnosed by CT. In our cases, CT was used, and the results were described. According to the density of the picture, CT findings of chronic subdural hematoma could be classified into 3 types, those of higher density than that of the cerebral paranchyma, those of isodensity, and those of lower density than that of the cerebral parenchyma. The difference among them appeared to be due to variation in the fluid in hematoma, especially that in hemoglobin concentration. Chronic subdural hematoma was found in 27 of 388 cases of head trauma in which CT was undertaken in our department of surgery for last 2 years. It is difficult to differenciate this disease from subdural edema or subarachnoideal retention of the cerebrospinal fluid. In many cases, use of contrast medium added no change to the CT picture. Cerebral angiography is necessary for definite diagnosis of the disease. Chronic subdural hematoma gives more varieties of findings than other intracranial hematomas. However, if the film is very carefully read, CT is still useful for diagnosing this disease in spite of initially remarked difficulties. (Ueda, J.)

  19. Impact of respiratory-correlated CT sorting algorithms on the choice of margin definition for free-breathing lung radiotherapy treatments.

    Science.gov (United States)

    Thengumpallil, Sheeba; Germond, Jean-François; Bourhis, Jean; Bochud, François; Moeckli, Raphaël

    2016-06-01

    To investigate the impact of Toshiba phase- and amplitude-sorting algorithms on the margin strategies for free-breathing lung radiotherapy treatments in the presence of breathing variations. 4D CT of a sphere inside a dynamic thorax phantom was acquired. The 4D CT was reconstructed according to the phase- and amplitude-sorting algorithms. The phantom was moved by reproducing amplitude, frequency, and a mix of amplitude and frequency variations. Artefact analysis was performed for Mid-Ventilation and ITV-based strategies on the images reconstructed by phase- and amplitude-sorting algorithms. The target volume deviation was assessed by comparing the target volume acquired during irregular motion to the volume acquired during regular motion. The amplitude-sorting algorithm shows reduced artefacts for only amplitude variations while the phase-sorting algorithm for only frequency variations. For amplitude and frequency variations, both algorithms perform similarly. Most of the artefacts are blurring and incomplete structures. We found larger artefacts and volume differences for the Mid-Ventilation with respect to the ITV strategy, resulting in a higher relative difference of the surface distortion value which ranges between maximum 14.6% and minimum 4.1%. The amplitude- is superior to the phase-sorting algorithm in the reduction of motion artefacts for amplitude variations while phase-sorting for frequency variations. A proper choice of 4D CT sorting algorithm is important in order to reduce motion artefacts, especially if Mid-Ventilation strategy is used. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Objectivity applied to embodied subjects in health care and social security medicine: definition of a comprehensive concept of cognitive objectivity and criteria for its application.

    Science.gov (United States)

    Solli, Hans Magnus; Barbosa da Silva, António

    2018-03-02

    The article defines a comprehensive concept of cognitive objectivity (CCCO) applied to embodied subjects in health care. The aims of this study were: (1) to specify some necessary conditions for the definition of a CCCO that will allow objective descriptions and assessments in health care, (2) to formulate criteria for application of such a CCCO, and (3) to investigate the usefulness of the criteria in work disability assessments in medical certificates from health care provided for social security purposes. The study design was based on a philosophical conceptual analysis of objectivity and subjectivity, the phenomenological notions 'embodied subject', 'life-world', 'phenomenological object' and 'empathy', and an interpretation of certificates as texts. The study material consisted of 18 disability assessments from a total collection of 86 medical certificates provided for social security purposes, written in a Norwegian hospital-based mental health clinic. Four necessary conditions identified for defining a CCCO were: (A) acknowledging the patient's social context and life-world, (B) perceiving patients as cognitive objects providing a variety of meaningful data (clinical, psychometric, and behavioural data - i.e. activities and actions, meaningful expressions and self-reflection), (C) interpreting data in context, and (D) using general epistemological principles. The criteria corresponding to these conditions were: (a) describing the patient's social context and recognizing the patient's perspective, (b) taking into consideration a variety of quantitative and qualitative data drawn from the clinician's perceptions of the patient as embodied subject, (c) being aware of the need to interpret the data in context, and (d) applying epistemological principles (professional expertise, dialogical intersubjectivity, impartiality, accuracy and correctness). Genuine communication is presupposed. These criteria were tested in the work disability assessments of medical

  1. Transnet regenerative braking concept definition

    CSIR Research Space (South Africa)

    Giesler, Achmed

    2015-09-01

    Full Text Available + EOHMIC + ERHEOSTAT (Alvaro J. Lopez, 2014) This basic equation does not yet take into account the energy storage system of an onboard system. This equation is merely given as a brief example of what inputs simulation software require. Due to the high... that can lead to additional cost savings. Carbon tax is a new tax that is expected to be implemented on the 1st of January 2016. It will be phased in over a period to time to allow for smooth transition in adopting cleaner and more efficient processes...

  2. Electrostatic discharge concepts and definitions

    Energy Technology Data Exchange (ETDEWEB)

    Borovina, Dan L [Los Alamos National Laboratory

    2008-01-01

    Many objects -like a human body, plastic wrap, or a rolling cart -that are electrically neutral, overall, can gain a net electrostatic charge by means of one of three methods: induction, physical transfer, or triboelectric charging (separation of conductive surfaces). The result is a voltage difference between the charged object and other objects, creating a situation where current flow is likely if two objects come into contact or close proximity. This current flow is known as electrostatic discharge, or ESD. The energy and voltage of the discharge can be influenced by factors such as the temperature and humidity in the room, the types of materials or flooring involved, or the clothing and footwear a person uses. Given the possible ranges of the current and voltage characteristic of an ESD pulse, it is important to consider the safety risks associated with detonator handling, assembly and disassembly, transportation and maintenance. For main charge detonators, these safety risks include high explosive violent reactions (HEVR) as well as inadvertent nuclear detonations (lND).

  3. The impact of time between staging PET/CT and definitive chemo-radiation on target volumes and survival in patients with non-small cell lung cancer

    International Nuclear Information System (INIS)

    Everitt, Sarah; Plumridge, Nikki; Herschtal, Alan; Bressel, Mathias; Ball, David; Callahan, Jason; Kron, Tomas; Schneider-Kolsky, Michal; Binns, David; Hicks, Rodney J.

    2013-01-01

    Background and purpose: To investigate the impact of treatment delays on radiation therapy (RT) target volumes and overall survival (OS) in patients with non-small cell lung cancer (NSCLC) who underwent two baseline FDG PET/CT scans. Material and methods: Patients underwent a staging (PET1) and RT planning (PET2) FDG PET/CT scan. At PET1 all patients were eligible for radical chemo-RT. OS and progression-free survival (PFS) were compared for patients remaining eligible for radical RT and those treated palliatively because PET2 showed progression. RT target volumes were contoured using PET1 and PET2. Normal tissue doses were compared for patients remaining eligible for radical RT. Results: Eighty-two patients underwent PET2 scans between October 2004 and February 2007. Of these, 21 had a prior PET1 scan, median 23 days apart (range 8–176 days). Six patients (29%) were unsuitable for radical RT after PET2; five received palliative treatment and one received no treatment. Patients treated palliatively had significantly worse OS and PFS than patients treated radically p < 0.001. Mean RT tumour volume increased from 105cc to 198cc (p < 0.005) between scans. Conclusions: Disease progression while awaiting initiation of curative RT in NSCLC is associated with larger treatment volumes and worse survival

  4. PERFORMANCE - AN EVOLVING CONCEPT

    OpenAIRE

    Assist. Mirela-Oana Pintea Ph.D Student; Lect. Monica-Violeta Achim

    2010-01-01

    The concept of performance is a problematic concept and will remain so as long as the definition of company performance varies depending on the interests of users of information. On this consideration, no consensus was reached regarding the definition, methodology and performance models used. Defining this concept is realized in accordance with its objectives of users of information, while the methodology and models used are influenced by legal regulations and management policies. The approac...

  5. The Venera-D Mission Concept: Evaluation by a Joint Science Definition Team of a Means for the Comprehensive Scientific Exploration of Venus

    Science.gov (United States)

    Senske, D.; Zasova, L. V.; Economou, T.; Eismont, N.; Esposito, L. W.; Gerasimov, M.; Ignatiev, N. I.; Ivanov, M.; Jessup, K. L.; Korablev, O.; Tibor, K.; Limaye, S. S.; Martynov, A.; Ocampo, A.

    2016-12-01

    Located in the same part of the solar system and formed out of the same protoplanetary material, Venus is Earth's twin. Although these siblings have nearly the same size, mass, and density, the climate of Venus, fueled by a massive CO2 atmosphere has an enormous greenhouse effect with a surface pressure of 90 atm. and a temperature of 470°C. Shrouded in clouds of sulfuric acid, the surface lacks water and has been sculpted by volcanism and deformed by faulting and folding forming rifts and belts of mountains. The lack of an intrinsic magnetic field suggests the planet's interior structure may be different than that of the earth. The study of Venus will aid in better understanding our own world and the possible future evolution of our climate. In particular, the instability of our climate and the increase in amount of greenhouse gases-can our climate be slowly going in Venus' direction? Despite the advancement in understanding achieved from previous and ongoing missions, the key questions concerning the origin and evolution of Venus and its climate cannot be solved by observations from orbit alone. Direct measurements in the atmosphere and on the surface are required. In this regard, a Joint Science Definition Team (JSDT) chartered by NASA and IKI/Roscosmos has been studying a concept for the comprehensive investigation of Venus that would consist of an orbiter (>3 yr. of operation) and a lander (2 hrs. on the surface). The scientific goals of the concept are tied closely to the key objectives established by VEXAG and the NASA Planetary Decadal Survey and include: investigation of the thermal structure and chemical composition of the atmosphere and clouds, abundances and isotopic ratios of the light and noble gases; study of the thermal balance, dynamics, and super-rotation of the atmosphere; determination of the surface mineralogy and elemental composition including key radioactive isotopes; study of potential current volcanic and electrical activity; and study of

  6. Quality evaluation of radiotherapy treatment planning using 3-dimensional CT images

    International Nuclear Information System (INIS)

    Araki, Yutaka; Isobe, Yoshihide; Ozaki, Shin; Hosoki, Takuya; Mori, Shigeru; Ikeda, Hiroshi.

    1984-01-01

    Recently superimposition of dose distribution onto CT images has become available with the use of planning computers. However, the distribution is mostly along the plane of central axis of the beam, and evaluation of the quality of planning has not yet been established. In this paper, a method to evaluate the quality is demonstrated, using the extended definitions of ICRU 29 concept in to 3-dimensions. Therapeutic efficiency (Target Volume dose/Treatment Volume dose) is the main key to evaluate it. Concept and procedures are described in detail with two case examples. (author)

  7. Stress: a concept analysis.

    Science.gov (United States)

    Goodnite, Patricia M

    2014-01-01

    To analyze the concept of stress and provide an operational definition of stress. Literature review revealed that stress is a commonly used, but often ambiguous, term. Findings supported a definition of stress entailing an individual's perception of a stimulus as overwhelming, which in turn elicits a measurable response resulting in a transformed state. This analysis adopts a dynamic definition of stress that may serve to encourage communication, promote reflection, and enhance concept understanding. This definition may provide direction for future work, as well as enhance efforts to serve patients affected by stress. © 2013 Wiley Periodicals, Inc.

  8. TU-E-BRA-11: Volume of Interest Cone Beam CT with a Low-Z Linear Accelerator Target: Proof-of-Concept.

    Science.gov (United States)

    Robar, J; Parsons, D; Berman, A; MacDonald, A

    2012-06-01

    This study demonstrates feasibility and advantages of volume of interest (VOI) cone beam CT (CBCT) imaging performed with an x-ray beam generated from 2.35 MeV electrons incident on a carbon linear accelerator target. The electron beam energy was reduced to 2.35 MeV in a Varian 21EX linear accelerator containing a 7.6 mm thick carbon x-ray target. Arbitrary imaging volumes were defined in the planning system to produce dynamic MLC sequences capable of tracking off-axis VOIs in phantoms. To reduce truncation artefacts, missing data in projection images were completed using a priori DRR information from the planning CT set. The feasibility of the approach was shown through imaging of an anthropomorphic phantom and the head-and-neck section of a lamb. TLD800 and EBT2 radiochromic film measurements were used to compare the VOI dose distributions with those for full-field techniques. CNR was measured for VOIs ranging from 4 to 15 cm diameter. The 2.35 MV/Carbon beam provides favorable CNR characteristics, although marked boundary and cupping artefacts arise due to truncation of projection data. These artefacts are largely eliminated using the DRR filling technique. Imaging dose was reduced by 5-10% and 75% inside and outside of the VOI, respectively, compared to full-field imaging for a cranial VOI. For the 2.35 MV/Carbon beam, CNR was shown to be approximately invariant with VOI dimension for bone and lung objects. This indicates that the advantage of the VOI approach with the low-Z target beam is substantial imaging dose reduction, not improvement of image quality. VOI CBCT using a 2.35 MV/Carbon beam is a feasible technique whereby a chosen imaging volume can be defined in the planning system and tracked during acquisition. The novel x-ray beam affords good CNR characteristics while imaging dose is localized to the chosen VOI. Funding for this project has been received from Varian Medical, Incorporated. © 2012 American Association of Physicists in Medicine.

  9. Concept - or no concept

    DEFF Research Database (Denmark)

    Thorsteinsson, Uffe

    1999-01-01

    Discussion about concept in industrial companies. A method for mapping of managerial concept in specific area is shown......Discussion about concept in industrial companies. A method for mapping of managerial concept in specific area is shown...

  10. A new consistent definition of the homogenized diffusion coefficient of a lattice, limitations of the homogenization concept, and discussion of previously defined coefficients

    International Nuclear Information System (INIS)

    Deniz, V.C.

    1980-01-01

    The problem concerned with the correct definition of the homogenized diffusion coefficient of a lattice, and the concurrent problem of whether or not a homogenized diffusion equation can be formally set up, is studied by a space-energy-angle dependent treatment for a general lattice cell using an operator notation which applies to any eigen-problem. A new definition of the diffusion coefficient is given, which combines within itself the individual merits of the two definitions of Benoist. The relation between the new coefficient and the ''uncorrected'' Benoist coefficient is discussed by considering continuous-spectrum and multi-group diffusion equations. Other definitions existing in the literature are briefly discussed. It is concluded that a diffusion coefficient should represent only leakage effects. A comparison is made between the homogenization approach and the approach via eigen-coefficients, and brief indications are given of a possible scheme for the latter. (author)

  11. CT pelvimetry

    International Nuclear Information System (INIS)

    Vicens, J.L.; Charles, G.; Le Berre, J.; Flageat, J.

    1989-01-01

    Pelvimetry aims at providing the obstetrician with information on the size and morphology of the female pelvis, thus enabling him to assess the obstetrical prognosis as accurately as possible. Computed tomography (CT) has several advantages, in particular the lower mother and fetus radiation dose. After a brief description of obstetrical anatomy, the usual CT exploration method is presented and its results are considered in terms of measurements, indices and morphological findings. If performed with a very strict exploration procedure, CT pelvimetry is a very reliable, fact and comfortable method of examination. All these advantages, combined with the minimized patient dose, should lead to an increasingly widespread use of this technique [fr

  12. CT and MRT in mediastinal and hilar masses. CT und MRT bei mediastinalen und hilaeren Raumforderungen

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, L.; Kramer, J.; Stiglbauer, R.; Wimberger, D.; Imhof, H. (Vienna Univ. (Austria). Klinik fuer Radiodiagnostik Ludwig-Boltzmann-Institut fuer Radiologisch-Physikalische Tumordiagnostik, Vienna (Austria)); Metz, V. (Vienna Univ. (Austria). 2. Chirurgische Klinik)

    1990-11-01

    Thirty-eight patients with mediastinal and/or hilar masses were imaged by computed tomography (CT) and magnetic resonance imaging (MRI). Results were analyzed retrospectively regarding the ability to demonstrate the masses, their number, size, definition, location and tissue characteristics. CT and MRI showed equivalent results in 32 cases; additional information was obtained in two patients by CT, in four patients by MRI. In view of the specific advantages and limitations of both CT and MRI we believed that in patients with mediastinal and/or hilar masses, contrast enhanced CT remains the procedure of choice after performing plain chest radiographs; in certain cases MRI will prove useful for further evaluation. (orig.).

  13. CT Scan

    Science.gov (United States)

    ... disease, lung nodules and liver masses Monitor the effectiveness of certain treatments, such as cancer treatment Detect ... scan done in a hospital or an outpatient facility. CT scans are painless and, with newer machines, ...

  14. Thoracic CT

    Science.gov (United States)

    ... through a vein (IV) in your hand or forearm. It may be given through the rectum using ... CT scan Vertebra, thoracic (mid back) Normal lung anatomy Thoracic organs References Gotway MB, Panse PM, Gruden ...

  15. CT Enterography

    Science.gov (United States)

    ... a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. These ... other medical conditions, and if you have a history of heart disease, asthma, diabetes, kidney disease or ...

  16. Elaborating on Threshold Concepts

    Science.gov (United States)

    Rountree, Janet; Robins, Anthony; Rountree, Nathan

    2013-01-01

    We propose an expanded definition of Threshold Concepts (TCs) that requires the successful acquisition and internalisation not only of knowledge, but also its practical elaboration in the domains of applied strategies and mental models. This richer definition allows us to clarify the relationship between TCs and Fundamental Ideas, and to account…

  17. C++QEDv2: The multi-array concept and compile-time algorithms in the definition of composite quantum systems

    Science.gov (United States)

    Vukics, András

    2012-06-01

    C++QED is a versatile framework for simulating open quantum dynamics. It allows to build arbitrarily complex quantum systems from elementary free subsystems and interactions, and simulate their time evolution with the available time-evolution drivers. Through this framework, we introduce a design which should be generic for high-level representations of composite quantum systems. It relies heavily on the object-oriented and generic programming paradigms on one hand, and on the other hand, compile-time algorithms, in particular C++ template-metaprogramming techniques. The core of the design is the data structure which represents the state vectors of composite quantum systems. This data structure models the multi-array concept. The use of template metaprogramming is not only crucial to the design, but with its use all computations pertaining to the layout of the simulated system can be shifted to compile time, hence cutting on runtime. Program summaryProgram title: C++QED Catalogue identifier: AELU_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AELU_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions:http://cpc.cs.qub.ac.uk/licence/aelu_v1_0.html. The C++QED package contains other software packages, Blitz, Boost and FLENS, all of which may be distributed freely but have individual license requirements. Please see individual packages for license conditions. No. of lines in distributed program, including test data, etc.: 597 974 No. of bytes in distributed program, including test data, etc.: 4 874 839 Distribution format: tar.gz Programming language: C++ Computer: i386-i686, x86_64 Operating system: In principle cross-platform, as yet tested only on UNIX-like systems (including Mac OS X). RAM: The framework itself takes about 60 MB, which is fully shared. The additional memory taken by the program which defines the actual physical system (script) is typically less than 1 MB. The memory storing

  18. Mixed connective tissue disease associated with noted pulmonary CT findings

    International Nuclear Information System (INIS)

    Yamazaki, Souji; Tsukada, Atsuko; Furuya, Tatsutaka

    1984-01-01

    CT was performed in a 56-year-old woman with mixed connective tissue disease (MCTD). Much more definitive pulmonary findings were obtained by CT than by the conventional chest x-ray examination and pulmonary function test. CT findings disclosed pulmonary lesions extremely similar to those in cases of progressive systemic sclerosis. Pulmonary CT was considered useful in examining pulmonary lesions for MCTD. (Namekawa, K.)

  19. Usefulness of multi-plane dynamic subtraction CT (MPDS-CT) for intracranial high density lesions

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Ryo; Kumazaki, Tatsuo [Nippon Medical School, Tokyo (Japan)

    1996-02-01

    We present a new CT technique using the high speed CT scanner in detection and evaluation of temporal and spatial contrast enhancement of intracranial high density lesions. A multi-plane dynamic subtraction CT (MPDS-CT) was performed in 21 patients with intracranial high density lesions. These lesions consisted of 10 brain tumors, 7 intracerebral hemorrhages and 4 vascular malformations (2 untreated, 2 post-embolization). Baseline study was first performed, and 5 sequential planes of covering total high density lesions were selected. After obtaining the 5 sequential CT images as mask images, three series of multi-plane dynamic CT were performed for the same 5 planes with an intravenous bolus injection of contrast medium. MPDS-CT images were reconstructed by subtracting dynamic CT images from the mask ones. MPDS-CT were compared with conventional contrast-enhanced CT. MPDS-CT images showed the definite contrast enhancement of high density brain tumors and vascular malformations which were not clearly identified on conventional contrast-enhanced CT images because of calcified or hemorrhagic lesions and embolic materials, enabling us to eliminate enhanced abnormalities with non-enhanced areas such as unusual intracerebral hemorrhages. MPDS-CT will provide us further accurate and objective information and will be greatly helpful for interpreting pathophysiologic condition. (author).

  20. Concepts of scale

    NARCIS (Netherlands)

    Padt, F.J.G.; Arts, B.J.M.

    2014-01-01

    This chapter provides some clarity to the scale debate. It bridges a variety of approaches, definitions and jargons used in various disciplines in order to provide common ground for a concept of scale as a basis for scale-sensitive governance of the environment. The chapter introduces the concept of

  1. A new consistent definition of the homogenized diffusion coefficient of a lattice, limitations of the homogenization concept, and discussion of previously defined coefficients

    International Nuclear Information System (INIS)

    Deniz, V.C.

    1978-01-01

    The problem concerned with the correct definition of the homogenized diffusion coefficient of a lattice, and the concurrent problem of whether or not a homogenized diffusion equation can be formally set up, is studied by a space-energy angle dependent treatment for a general lattice cell; using an operator notation which applies to any eigen-problem. It is shown that the diffusion coefficient should represent only leakage effects. A new definition of the diffusion coefficient is given, which combines within itself the individual merits of each of the two definitions of Benoist, and reduces to the 'uncorrected' Benoist coefficient in certain cases. The conditions under which a homogenized diffusion equation can be obtained are discussed. A compatison is made between the approach via a diffusion equation and the approach via the eigen-coefficients of Deniz. Previously defined diffusion coefficients are discussed, and it is shown that the transformed eigen-coefficients proposed by Gelbard and by Larsen are unsuitable as diffusion coefficients, and that the cell-edge normalization of the Bonalumi coefficient is not physically justifiable. (author)

  2. Empowerment: a Concept Analysis

    OpenAIRE

    Febriana, Dara

    2011-01-01

    This paper conceptually analyzed the concept of empowerment using the strategies of Walker & Avant (2005) the objective is to clarify the meaning of the concept and to clearly identify empowerment characteristic that will provide consistent definition for practice and future research. Empowerment is defined and examined using relevant resources of literatures and selected empirical referents that described empowerment as a complex and multidimensional concept. Within nursing context empowerme...

  3. Conceptual design of a crewed reusable space transportation system aimed at parabolic flights: stakeholder analysis, mission concept selection, and spacecraft architecture definition

    Science.gov (United States)

    Fusaro, Roberta; Viola, Nicole; Fenoglio, Franco; Santoro, Francesco

    2017-03-01

    This paper proposes a methodology to derive architectures and operational concepts for future earth-to-orbit and sub-orbital transportation systems. In particular, at first, it describes the activity flow, methods, and tools leading to the generation of a wide range of alternative solutions to meet the established goal. Subsequently, the methodology allows selecting a small number of feasible options among which the optimal solution can be found. For the sake of clarity, the first part of the paper describes the methodology from a theoretical point of view, while the second part proposes the selection of mission concepts and of a proper transportation system aimed at sub-orbital parabolic flights. Starting from a detailed analysis of the stakeholders and their needs, the major objectives of the mission have been derived. Then, following a system engineering approach, functional analysis tools as well as concept of operations techniques allowed generating a very high number of possible ways to accomplish the envisaged goals. After a preliminary pruning activity, aimed at defining the feasibility of these concepts, more detailed analyses have been carried out. Going on through the procedure, the designer should move from qualitative to quantitative evaluations, and for this reason, to support the trade-off analysis, an ad-hoc built-in mission simulation software has been exploited. This support tool aims at estimating major mission drivers (mass, heat loads, manoeuverability, earth visibility, and volumetric efficiency) as well as proving the feasibility of the concepts. Other crucial and multi-domain mission drivers, such as complexity, innovation level, and safety have been evaluated through the other appropriate analyses. Eventually, one single mission concept has been selected and detailed in terms of layout, systems, and sub-systems, highlighting also logistic, safety, and maintainability aspects.

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses ... CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  5. Effectiveness of quantitative MAA SPECT/CT for the definition of vascularized hepatic volume and dosimetric approach: phantom validation and clinical preliminary results in patients with complex hepatic vascularization treated with yttrium-90-labeled microspheres.

    Science.gov (United States)

    Garin, Etienne; Lenoir, Laurence; Rolland, Yan; Laffont, Sophie; Pracht, Marc; Mesbah, Habiba; Porée, Philippe; Ardisson, Valérie; Bourguet, Patrick; Clement, Bruno; Boucher, Eveline

    2011-12-01

    The goal of this study was to assess the use of quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) analysis for vascularized volume measurements in the use of the yttrium-90-radiolabeled microspheres (TheraSphere). A phantom study was conducted for the validation of SPECT/CT volume measurement. SPECT/CT quantitative analysis was used for the measurement of the volume of distribution of the albumin macroaggregates (MAA; i.e., the vascularized volume) in the liver and the tumor, and the total activity contained in the liver and the tumor in four consecutive patients presenting with a complex liver vascularization referred for a treatment with TheraSphere. SPECT/CT volume measurement proved to be accurate (mean error <7%) and reproducible (interobserver concordance 0.99). For eight treatments, in cases of complex hepatic vascularization, the hepatic volumes based on angiography and CT led to a relative overestimation or underestimation of the vascularized hepatic volume by 43.2 ± 32.7% (5-87%) compared with SPECT/CT analyses. The vascularized liver volume taken into account calculated from SPECT/CT data, instead of angiography and CT data, results in modifying the activity injected for three treatments of eight. Moreover, quantitative analysis of SPECT/CT allows us to calculate the absorbed dose in the tumor and in the healthy liver, leading to doubling of the injected activity for one treatment of eight. MAA SPECT/CT is accurate for volume measurements. It provides a valuable contribution to the therapeutic planning of patients presenting with complex hepatic vascularization, in particular for calculating the vascularized liver volume, the activity to be injected and the absorbed doses. Studies should be conducted to assess the role of quantitative MAA/SPECT CT in therapeutic planning.

  6. Clinical applications of SPECT-CT

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadzadehfar, Hojjat; Biersack, Hans-Juergen (eds.) [University Hospital Bonn (Germany). Dept. of Nuclear Medicine

    2014-06-01

    Covers the full spectrum of clinical applications of SPECT/CT in diagnosis of benign and malignant diseases. Includes chapters on the use of SPECT/CT for dosimetry and for therapy planning. Completely up to date. Many helpful illustrations. SPECT/CT cameras have considerably improved diagnostic accuracy in recent years. Such cameras allow direct correlation of anatomic and functional information, resulting in better localization and definition of scintigraphic findings. In addition to this anatomic referencing, CT coregistration provides superior quantification of radiotracer uptake based on the attenuation correction capabilities of CT. Useful applications of SPECT/CT have been identified not only in oncology but also in other specialties such as orthopedics and cardiology. This book covers the full spectrum of clinical applications of SPECT/CT in diagnosis and therapy planning of benign and malignant diseases. Opening chapters discuss the technology and physics of SPECT/CT and its use for dosimetry. The role of SPECT/CT in the imaging of a range of pathologic conditions is then addressed in detail. Applications covered include, among others, imaging of the thyroid, bone, and lungs, imaging of neuroendocrine tumors, cardiac scintigraphy, and sentinel node scintigraphy. Individual chapters are also devoted to therapy planning in selective internal radiation therapy of liver tumors and bremsstrahlung SPECT/CT. Readers will find this book to be an essential and up-to-date source of information on this invaluable hybrid imaging technique.

  7. Definitions and Basic Concepts of Supply and Demand Analysis Used to Determine Market Equilibrium. Principles of Economics II (Microeconomics), Lesson Plan No. 6.

    Science.gov (United States)

    Chiu-Irion, Vicky

    Developed as part of a 37.5-hour microeconomics course, this lesson plan focuses on the concepts of supply and demand analysis used to determine market equilibrium. The objectives of the 50-minute lesson are to enable the student to: (1) explain how a demand schedule is derived from raw data; (2) graph a demand curve from the demand schedule; (3)…

  8. The CO{sub 2} challenge. Aggressive downsizing for HSDI diesel - engine concept definition; Herausforderung CO{sub 2}. Aggessives Downsizing fuer HSDI-Diesel - Motorkonzeptdefinition

    Energy Technology Data Exchange (ETDEWEB)

    Sorger, Helfried; Howlett, Michael; Schnider, Wolfgang; Ausserhoffer, Norbert; Bartsch, Peter; Weissbaeck, Michael [AVL List GmbH, Graz (Austria); Soustelle, Olivier [Le Moteur Moderne, Palaiseau (France); Ragot, Patrick; Mallet, Philippe [Renault S.A.S., Rueil Malmaison (France)

    2010-07-01

    Against a background of consumer demand for low fuel consumption vehicles, as well as legislative pressure to reduce CO{sub 2} emissions, the automotive industry is currently developing solutions to significantly improve the efficiency of ICE-based powertrains. One answer to this challenge is the engine downsizing approach. A clear trend can be observed on the market already today: engines of 2.0L swept volume are replaced by engines with a size of about 1.6L. This paper describes the concept for an even more extreme downsizing approach for the next generation of powertrains by further reducing the engine size to 1.0L using a 3 cylinder concept with a specific power rating of 80 kW/L. AVL and Renault worked closely together to define a suitable diesel hybrid powertrain concept for EU6 emission limits. The consequences for the base engine design of such an aggressive downsizing approach were established by means of a design study supported by simulation. Key criteria for such a powertrain are to satisfy customer expectations for performance and driveability, as well as keep the NVH behaviour of the selected 3 cylinder engine configuration close to that of the traditional 4 cylinder engine reference base. The structural concept of this high power engine is based on a peak firing pressure limit of 190 bar. 2- and 4-valve per cylinder concepts are evaluated with regard to their effects on performance, emissions, fuel consumption and cost. The combustion- and EGR-system is defined with respect to EU6 emission compliance, taking into consideration DPF and NOx aftertreatment technologies. (orig.)

  9. CT cystography

    International Nuclear Information System (INIS)

    Tsili, A.

    2012-01-01

    Full text: Cancer of the urinary bladder is one of the commonest urothelial neoplasms. Conventional cystoscopy remains the mainstay in the diagnosis of urinary bladder carcinomas. But it is an invasive and uncomfortable procedure, associated with complications. Computed tomographic (CT) virtual cystoscopy has been proposed as an alternative imaging modality with potential advantages in the detection of urinary bladder neoplasms and good patient acceptance. It is a minimally invasive technique, allowing imaging of the urinary bladder in multiple planes and a 360 0 view. CT cystoscopy provides information about the location, size and morphologic features of urinary bladder lesions, indicating appropriate areas for biopsy. It can be performed in cases in which conventional cystoscopy is not feasible, such as in the presence of urethral strictures, marked prostatic hypertrophy or active bleeding, and in cases in which cystoscopic findings are inconclusive. The technique can be used to evaluate areas of the urinary bladder difficult to evaluate with cystoscopy, such as the anterior bladder neck and narrowmouthed diverticula. Finally, virtual cystoscopy provides both intraluminal and extraluminal pathologic changes, so intravesical disease and exrtavesical extension can be evaluated in the same study. One of the limitations of this technique is the difficulty to demonstrate small-sized lesions. The introduction of multi-detector row CT (MDCT) scanners was a major technological advancement because among other things it substantially improves z-axis resolution by reducing section collimation and allowing the detection of very small lesions. The near isotropic or isotropic pixels achieved with a multidetector CT scanner, enable the creation of multiplanar reformatted images with a resolution very close to that of the axial images and three-dimensional (3D) renderings of outstanding quality. Transverse, multiplanar reformations and virtual endoscopic images are complementary

  10. Bowel preparation for CT colonography

    International Nuclear Information System (INIS)

    Neri, Emanuele; Lefere, Philippe; Gryspeerdt, Stefaan; Bemi, Pietro; Mantarro, Annalisa; Bartolozzi, Carlo

    2013-01-01

    Bowel preparation represents an essential part of CT colonography, as the accuracy of the exam is strongly related to the adequacy of colonic cleansing, and a poor bowel preparation may compromise the diagnostic quality even despite optimization of all other acquisition parameters. Residual stool and fluid in the large bowel may affect the interpretation of the exam and may increase the number of false positives and false negatives. In this regard, the majority of patients having undergone CT colonography state that bowel preparation is the most unpleasant part. Unfortunately, to date no definite consensus has been reached about the ideal bowel preparation technique, and there is great variability in preparation strategies across diagnostic centers. The purpose of this review article is to describe the development and evolution of bowel preparation techniques in order to choose the best approach for optimizing the diagnostic quality of CT colonography in each patient

  11. Bowel preparation for CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele, E-mail: emanuele.neri@med.unipi.it [Diagnostic and Interventional Radiology, University of Pisa (Italy); Lefere, Philippe; Gryspeerdt, Stefaan [Department of Radiology, Stedelijk Ziekenhuis, Roeselare (Belgium); Bemi, Pietro; Mantarro, Annalisa; Bartolozzi, Carlo [Diagnostic and Interventional Radiology, University of Pisa (Italy)

    2013-08-15

    Bowel preparation represents an essential part of CT colonography, as the accuracy of the exam is strongly related to the adequacy of colonic cleansing, and a poor bowel preparation may compromise the diagnostic quality even despite optimization of all other acquisition parameters. Residual stool and fluid in the large bowel may affect the interpretation of the exam and may increase the number of false positives and false negatives. In this regard, the majority of patients having undergone CT colonography state that bowel preparation is the most unpleasant part. Unfortunately, to date no definite consensus has been reached about the ideal bowel preparation technique, and there is great variability in preparation strategies across diagnostic centers. The purpose of this review article is to describe the development and evolution of bowel preparation techniques in order to choose the best approach for optimizing the diagnostic quality of CT colonography in each patient.

  12. Introductory concepts

    International Nuclear Information System (INIS)

    Barnes, W.E.

    1983-01-01

    Physical theories are commonly classified as being either ''classical'' or ''modern''. The reasons for this distinction are both historical and substantive. Limited in the sophistication of their measuring instruments, early scientists proposed theories appropriate for the description of the simplest and most accessible physical phenomena, e.g., the trajectories of the planets. Because of the class of phenomena observed, certain beliefs came to underlie all classical theories with regard to the nature of time, space, matter, etc. For example, the idea was undisputed that an object has at all times both a definite position and velocity. Not until the interior of the atom and the nature of electromagnetic radiation were explored was it discovered that the concepts of classical physics are inadequate to deal with many phenomena. A reassessment of fundamental postulates led to the formulation of modern physics which, it is believed, successfully treats the behavior of all physical systems. To gain an understanding of the rudiments of modern physics, one proceeds as the early scientists did by first mastering the classical concepts that emerge from their intuitive picture of the world. Modifications of these concepts are subsequently introduced which allow a more accurate treatment of physical phenomena, particularly atomic and nuclear systems

  13. Cardiac CT

    International Nuclear Information System (INIS)

    Dewey, Marc

    2011-01-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  14. Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2011-07-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  15. Proposal for a universal definition of cerebral infarction.

    Science.gov (United States)

    Saver, Jeffrey L

    2008-11-01

    Cerebral infarction is a leading cause of disability and death worldwide but has no uniform international definition. Recent diagnostic advances have revised fundamental concepts in cerebral and cardiac ischemia. Cardiologists, already possessed of a nosologic framework distinguishing myocardial infarction from unstable angina on the basis of tissue state, promulgated a new "universal" tissue definition of myocardial infarction incorporating insights afforded by assays of cardiac troponin, a serum biomarker exquisitely sensitive to myocardial injury. Concurrently, vascular neurologists proposed a new tissue, rather than time, criterion to distinguish transient ischemia attack from cerebral infarction, responding to perspectives provided by diffusion MRI and cerebral blood volume CT, imaging biomarkers highly sensitive to neuronal injury. To complete this conceptual realignment, vascular neurology must now advance a clear, uniform, and operationalizable tissue definition of cerebral infarction. This review proposes cerebral infarction be defined as brain or retinal cell death due to prolonged ischemia. This definition categorizes both pannecrosis and neuronal dropout ("complete" and "incomplete" infarcts in classic neuropathologic terminology) as cerebral infarcts. Making the presence of any neuronal or glial cell death essential yields a definition of cerebral infarction that has high relevance to patients, physicians, and policymakers; is more easily applied in clinical practice; fosters action in acute care; harmonizes with myocardial ischemia classification; and focuses diagnostic evaluation on the cause of brain ischemia and the occurrence of end organ injury. The term cerebral infarction should be used when there is evidence of brain or retinal cell death due to cerebral ischemia.

  16. Dual, use-based definition of "system"

    CSIR Research Space (South Africa)

    Gonçalves, DP

    2015-09-01

    Full Text Available The standard definition (ISO 15288, 2008) of the concept of a system is not complete and is the definition of a closed system. Such a definition is inadequate for systems engineering. A use-based definition is proposed which spans the open...

  17. CT scan of Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, T; Noguchi, S; Nishitani, H [National Sanatorium of Utano, Kyoto (Japan); Kitano, H; Ikegami, Y

    1981-04-01

    In forty-eight patients with Parkinson's disease, we examined the ventricular size and the degree of cortical atrophy which were measured by the photos of CT scan and compared them with their clinical symptoms and side effects of anti-parkinsonian drugs. The ventricular size was expressed as the ventricular ratio which is the percentage of superimposed lateral ventricular area to the white and gray matter area at the slice number 2B of CT scan photos. The degree of the cortical atrophy was expressed as the sulcal numbers which were clearly visualized at the slice number 3B or 4A of CT scan photos. We used the CT scan photos of age-matched other patients which did not show definit central nervous system abnormalities. Our findings were as follows: (1) The ventricular enlargement was observed in the parkinsonian patients who showed dementia and/or Yahr's classification grades IV or V. (2) There was no correlation between the duration of this disease and the L--dopa treatments with the ventricular size and sulcal numbers. (3) The side effects of drugs such as visual hallucination were tended to be observed in the patients who showed the ventricular enlargement. (4) There was no definite correlation between the degree of cortical atrophy with clinical symptoms and side effects of various drugs. These findings suggested that the ventricular enlargement in Parkinson's disease was an important sign of dementia and the tendency of appearance of side effects of various drugs.

  18. CT scan of Parkinson's disease

    International Nuclear Information System (INIS)

    Konishi, Tetsuro; Noguchi, Sadako; Nishitani, Hiroshi; Kitano, Haruo; Ikegami, Yoshinori.

    1981-01-01

    In forty-eight patients with Parkinson's disease, we examined the ventricular size and the degree of cortical atrophy which were measured by the photos of CT scan and compared them with their clinical symptoms and side effects of anti-parkinsonian drugs. The ventricular size was expressed as the ventricular ratio which is the percentage of superimposed lateral ventricular area to the white and gray matter area at the slice number 2B of CT scan photos. The degree of the cortical atrophy was expressed as the sulcal numbers which were clearly visualized at the slice number 3B or 4A of CT scan photos. We used the CT scan photos of age-matched other patients which did not show definit central nervous system abnormalities. Our findings were as follows: (1) The ventricular enlargement was observed in the parkinsonian patients who showed dementia and/or Yahr's classification grades IV or V. (2) There was no correlation between the duration of this disease and the L--dopa treatments with the ventricular size and sulcal numbers. (3) The side effects of drugs such as visual hallucination were tended to be observed in the patients who showed the ventricular enlargement. (4) There was no definite correlation between the degree of cortical atrophy with clinical symptoms and side effects of various drugs. These findings suggested that the ventricular enlargement in Parkinson's disease was an important sign of dementia and the tendency of appearance of side effects of various drugs. (author)

  19. Self-Concept Is a Concept Worth Considering

    Science.gov (United States)

    Shields, Nora

    2009-01-01

    There is a growing recognition of the importance of self-concept in the pediatric rehabilitation research literature. There also is confusion and inconsistency in the definitions of and the terminology used to describe self-concept. What is agreed is that self-concept is multidimensional, comprising a child's perception of their personal…

  20. CT-Urography; Urografia CT

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Palma, Ludovico; Grotto, Maurizio [Trieste Univ., Trieste (Italy). Dipartimento di scienze cliniche, morfologiche e tecnologiche, UCO di radiologia; Morra, Aldo [CRO, Aviano (Italy). Reparto di radiologia

    2005-09-15

    In this paper we present an overview of CT-Urography. With the advent of multislice CT scanners and the evolution of image processing methods this technique now affords optimal urographic images comparable to those obtained with conventional techniques. We describe the acquisition techniques and protocols used by the various authors. Effective radiation dose has conditioned the use of CT-Urography so that the tendency today is to reduce the number of scans by performing, after the non enhanced scan, a single contrast-enhanced scan comprising both the nephrographic and urographic phase. With the use of multislice CT the quality of the urogram improves with the number of slices. We illustrate a variety of processing techniques, multiplanar reconstruction (MPR), maximum (MIP) and average intensity projection (AIP) and volume rendering (VR) and present a series of upper urinary tract tumours testifying to the superiority of the AIP technique over MIP. We then review the results of comparative studies of CT-Urography with conventional urography in upper urinary tract diagnostics. Finally, we describe the advantages and limitations of CT-Urography. [Italian] Gli Autori presentano una panoramica sulla Urografia TC (Uro TC). L'avvento della TC multistrato e l'evoluzione delle tecniche di elaborazione consentono di ottenere dei quadri urografici ottimali comparativi con quelli convenzionali. Vengono ricordate le varie tecniche di acquisizione e i protocolli usati dai vari Autori. La dose effettiva di radiazioni ha rappresentato uno dei fattori condizionanti per cui oggi prevale l'orientamento di ridurre il numero di scansioni, considerando dopo la scansione senza mezzo di contrasto un'unica scansione contrasto grafica comprendente sia la fase nefrografica che quella urografica. Con l'uso della TC multistrato la qualita dell'urogramma migliora con l'aumento del numero degli strati. Vengono descritte le varie tecniche di elaborazione, la

  1. High resolution extremity CT for biomechanics modeling

    International Nuclear Information System (INIS)

    Ashby, A.E.; Brand, H.; Hollerbach, K.; Logan, C.M.; Martz, H.E.

    1995-01-01

    With the advent of ever more powerful computing and finite element analysis (FEA) capabilities, the bone and joint geometry detail available from either commercial surface definitions or from medical CT scans is inadequate. For dynamic FEA modeling of joints, precise articular contours are necessary to get appropriate contact definition. In this project, a fresh cadaver extremity was suspended in parafin in a lucite cylinder and then scanned with an industrial CT system to generate a high resolution data set for use in biomechanics modeling

  2. High resolution extremity CT for biomechanics modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, A.E.; Brand, H.; Hollerbach, K.; Logan, C.M.; Martz, H.E.

    1995-09-23

    With the advent of ever more powerful computing and finite element analysis (FEA) capabilities, the bone and joint geometry detail available from either commercial surface definitions or from medical CT scans is inadequate. For dynamic FEA modeling of joints, precise articular contours are necessary to get appropriate contact definition. In this project, a fresh cadaver extremity was suspended in parafin in a lucite cylinder and then scanned with an industrial CT system to generate a high resolution data set for use in biomechanics modeling.

  3. Conception and Definition Method of Tolerant Water Yield and Sediment Yield of Small Watershed%小流域容许产水产沙量的概念与确定方法

    Institute of Scientific and Technical Information of China (English)

    杜树汉; 刘刚才

    2011-01-01

    The conception and definition method of tolerant water yield and sediment yield of small watershed were put forward. The main influencing factors of tolerant water yield and sediment yield of small watershed were soil forming rate, productivity of land, water body and water quality, sediment transport amount and quantity of water resources.%提出了小流域容许产水产沙量的概念及确定方法,指出小流域容许产水产沙量的主要影响因素为:成土速率、土地生产力、水体水质、泥沙输移量、水资源量.

  4. Pediatric CT quality management and improvement program

    Energy Technology Data Exchange (ETDEWEB)

    Larson, David B.; Chan, Frandics P.; Newman, Beverley; Fleischmann, Dominik [Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States); Molvin, Lior Z. [Stanford Hospital and Clinics, Stanford, CA (United States); Wang, Jia [Stanford University, Environmental Health and Safety, Stanford, CA (United States)

    2014-10-15

    Modern CT is a powerful yet increasingly complex technology that continues to rapidly evolve; optimal clinical implementation as well as appropriate quality management and improvement in CT are challenging but attainable. This article outlines the organizational structure on which a CT quality management and improvement program can be built, followed by a discussion of common as well as pediatric-specific challenges. Organizational elements of a CT quality management and improvement program include the formulation of clear objectives; definition of the roles and responsibilities of key personnel; implementation of a technologist training, coaching and feedback program; and use of an efficient and accurate monitoring system. Key personnel and roles include a radiologist as the CT director, a qualified CT medical physicist, as well as technologists with specific responsibilities and adequate time dedicated to operation management, CT protocol management and CT technologist education. Common challenges in managing a clinical CT operation are related to the complexity of newly introduced technology, of training and communication and of performance monitoring. Challenges specific to pediatric patients include the importance of including patient size in protocol and dose considerations, a lower tolerance for error in these patients, and a smaller sample size from which to learn and improve. (orig.)

  5. Pediatric CT quality management and improvement program

    International Nuclear Information System (INIS)

    Larson, David B.; Chan, Frandics P.; Newman, Beverley; Fleischmann, Dominik; Molvin, Lior Z.; Wang, Jia

    2014-01-01

    Modern CT is a powerful yet increasingly complex technology that continues to rapidly evolve; optimal clinical implementation as well as appropriate quality management and improvement in CT are challenging but attainable. This article outlines the organizational structure on which a CT quality management and improvement program can be built, followed by a discussion of common as well as pediatric-specific challenges. Organizational elements of a CT quality management and improvement program include the formulation of clear objectives; definition of the roles and responsibilities of key personnel; implementation of a technologist training, coaching and feedback program; and use of an efficient and accurate monitoring system. Key personnel and roles include a radiologist as the CT director, a qualified CT medical physicist, as well as technologists with specific responsibilities and adequate time dedicated to operation management, CT protocol management and CT technologist education. Common challenges in managing a clinical CT operation are related to the complexity of newly introduced technology, of training and communication and of performance monitoring. Challenges specific to pediatric patients include the importance of including patient size in protocol and dose considerations, a lower tolerance for error in these patients, and a smaller sample size from which to learn and improve. (orig.)

  6. FDG-PET/CT in oncology. German guideline

    International Nuclear Information System (INIS)

    Krause, B.J.; Beyer, T.; Bockisch, A.; Delbeke, D.; Kotzerke, J.; Minkov, V.; Reiser, M.; Willich, N.

    2007-01-01

    FDG-PET/CT examinations combine metabolic and morphologic imaging within an integrated procedure. Over the past decade PET/CT imaging has gained wide clinical acceptance in the field of oncology. This FDG-PET/CT guideline focuses on indications, data acquisition and processing as well as documentation of FDG-PET/CT examinations in oncologic patients within a clinical and social context specific to Germany. Background information and definitions are followed by examples of clinical and research applications of FDG-PET/CT. Furthermore, protocols for CT scanning (low dose and contrast-enhanced CT) and PET emission imaging are discussed. Documentation and reporting of examinations are specified. Image interpretation criteria and sources of errors are discussed. Quality control for FDG and PET/CT-systems, qualification requirements of personnel as well as legal aspects are presented. (orig.)

  7. Definition of the key target volume in radiosurgical management of arteriovenous malformations: a new dynamic concept based on angiographic circulation time.

    Science.gov (United States)

    Valle, Ramiro Del; Zenteno, Marco; Jaramillo, José; Lee, Angel; De Anda, Salvador

    2008-12-01

    The cumulative experience worldwide indicates complete radiosurgical obliteration rates of brain arteriovenous malformations (AVMs) ranging from 35 to 90%. The purpose of this study was to propose a strategy to increase the obliteration rate for AVMs through the dynamic definition of the key target volume (KTV). A prospective series of patients harboring an AVM was assessed using digital subtraction angiography in which a digital counter was used to measure the several stages of the frame-by-frame circulation time. All the patients were analyzed using dynamic measurement planning to define the KTV, corresponding to the volume of the shunt with the least vascular resistance and the earliest venous drainage. All patients underwent catheter-based angiography, a subgroup was additionally assessed by means of a superselective catheterization, and among these a further subgroup received embolization. The shunts were also categorized according to their angioarchitectural type: fistulous, plexiform, or mixed. The authors applied the radiosurgery-based grading system (RBGS) as well to find a correlation with the obliteration rate. This series includes 44 patients treated by radiosurgery; global angiography was performed for all patients, including dynamic measurement planning. Eighty-four percent of them underwent superselective catheterization, and 50% of the total population underwent embolization. In the embolized arm of the study, the pretreatment volume was up to 120 ml. In patients with a single treatment, the mean volume was 8.5 ml, and the median volume was 6.95 +/- 4.56 ml (mean +/- standard deviation), with a KTV of up to 15 ml. For prospectively staged radiosurgery, the mean KTV was 28 ml. The marginal radiation dose was 18-22 Gy, with a mean of dose 20 Gy. The mean RBGS score was 1.70. The overall obliteration rate was 91%, including the repeated radiosurgery group (4 patients), in which 100% showed complete obliteration. The overall permanent deficit was 2 of

  8. Temporal resolution and motion artifacts in single-source and dual-source cardiac CT

    International Nuclear Information System (INIS)

    Schöndube, Harald; Allmendinger, Thomas; Stierstorfer, Karl; Bruder, Herbert; Flohr, Thomas

    2013-01-01

    Purpose: The temporal resolution of a given image in cardiac computed tomography (CT) has so far mostly been determined from the amount of CT data employed for the reconstruction of that image. The purpose of this paper is to examine the applicability of such measures to the newly introduced modality of dual-source CT as well as to methods aiming to provide improved temporal resolution by means of an advanced image reconstruction algorithm. Methods: To provide a solid base for the examinations described in this paper, an extensive review of temporal resolution in conventional single-source CT is given first. Two different measures for assessing temporal resolution with respect to the amount of data involved are introduced, namely, either taking the full width at half maximum of the respective data weighting function (FWHM-TR) or the total width of the weighting function (total TR) as a base of the assessment. Image reconstruction using both a direct fan-beam filtered backprojection with Parker weighting as well as using a parallel-beam rebinning step are considered. The theory of assessing temporal resolution by means of the data involved is then extended to dual-source CT. Finally, three different advanced iterative reconstruction methods that all use the same input data are compared with respect to the resulting motion artifact level. For brevity and simplicity, the examinations are limited to two-dimensional data acquisition and reconstruction. However, all results and conclusions presented in this paper are also directly applicable to both circular and helical cone-beam CT. Results: While the concept of total TR can directly be applied to dual-source CT, the definition of the FWHM of a weighting function needs to be slightly extended to be applicable to this modality. The three different advanced iterative reconstruction methods examined in this paper result in significantly different images with respect to their motion artifact level, despite exactly the same

  9. Temporal resolution and motion artifacts in single-source and dual-source cardiac CT.

    Science.gov (United States)

    Schöndube, Harald; Allmendinger, Thomas; Stierstorfer, Karl; Bruder, Herbert; Flohr, Thomas

    2013-03-01

    The temporal resolution of a given image in cardiac computed tomography (CT) has so far mostly been determined from the amount of CT data employed for the reconstruction of that image. The purpose of this paper is to examine the applicability of such measures to the newly introduced modality of dual-source CT as well as to methods aiming to provide improved temporal resolution by means of an advanced image reconstruction algorithm. To provide a solid base for the examinations described in this paper, an extensive review of temporal resolution in conventional single-source CT is given first. Two different measures for assessing temporal resolution with respect to the amount of data involved are introduced, namely, either taking the full width at half maximum of the respective data weighting function (FWHM-TR) or the total width of the weighting function (total TR) as a base of the assessment. Image reconstruction using both a direct fan-beam filtered backprojection with Parker weighting as well as using a parallel-beam rebinning step are considered. The theory of assessing temporal resolution by means of the data involved is then extended to dual-source CT. Finally, three different advanced iterative reconstruction methods that all use the same input data are compared with respect to the resulting motion artifact level. For brevity and simplicity, the examinations are limited to two-dimensional data acquisition and reconstruction. However, all results and conclusions presented in this paper are also directly applicable to both circular and helical cone-beam CT. While the concept of total TR can directly be applied to dual-source CT, the definition of the FWHM of a weighting function needs to be slightly extended to be applicable to this modality. The three different advanced iterative reconstruction methods examined in this paper result in significantly different images with respect to their motion artifact level, despite exactly the same amount of data being used

  10. RADIOLOGICAL TIPS CT-guided biopsy of suspected malignancy: A ...

    African Journals Online (AJOL)

    under appropriate medical therapy and the lesion was successfully excised. ... origin.[4] Typically, these sympathetic tumours secrete catecholamines. It should be noted that phaeochromocytomas, arising from the adrenal medulla, are, by definition, ... Radiologically, CT, MRI, metaidbenzylguanidine scan and PET imaging.

  11. CT urography

    Energy Technology Data Exchange (ETDEWEB)

    Korobkin, M. [Dept. of Radiology, Univ. of Michigan, Ann Arbor, MI (United States)

    2005-11-15

    With the advent of multidetector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract - the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mmin diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination - MDCTU. (orig.)

  12. General definition of the concept of "sport" as one of the basic constructs of the general theory of physical culture and sports theory

    Directory of Open Access Journals (Sweden)

    Vasil Sutula

    2018-02-01

    Full Text Available Purpose: to reveal modern ideas about the essence of the concept of "sport" and determine its role in the development of the general theory of physical culture and sports theory. Material & Methods: analysis of specialized literature, which highlights various aspects of the development of the field of people's activities related to the use of physical exercises. Results: in today's society there is an objective sphere of human activity related to the use of physical exercises, for which the name in domestic and foreign scientific and social practice is most often used the term "physical culture". Conclusion: the constitutive conditions of the process of developing a general theory of physical culture are singled out, it is shown that sport, as a special socio-cultural phenomenon, is a historically conditioned activity of people associated with the use of physical exercises, aimed at preparing and participating in competitions, as well as individual and socially significant results of such activity.

  13. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... are the limitations of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed ... nasal cavity by small openings. top of page What are some common uses of the procedure? CT ...

  14. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, ... than regular radiographs (x-rays). top of page What are some common uses of the procedure? CT ...

  15. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... preferable over CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder ...

  16. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  17. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ...

  19. Radiation exposure in CT-guided interventions

    Energy Technology Data Exchange (ETDEWEB)

    Kloeckner, Roman, E-mail: Roman.Kloeckner@unimedizin-mainz.de [Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz (Germany); Santos, Daniel Pinto dos; Schneider, Jens [Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz (Germany); Kara, Levent [Department of Radiology, Inselspital Bern, Freiburgstraße 18, 3010 Bern (Switzerland); Dueber, Christoph; Pitton, Michael B. [Department of Diagnostic and Interventional Radiology, Johannes Gutenberg-University, Langenbeckstraße 1, 55131 Mainz (Germany)

    2013-12-01

    Purpose: To investigate radiation exposure in computed tomography (CT)-guided interventions, to establish reference levels for exposure, and to discuss strategies for dose reduction. Materials and methods: We analyzed 1576 consecutive CT-guided procedures in 1284 patients performed over 4.5 years, including drainage placements; biopsies of different organs; radiofrequency and microwave ablations (RFA/MWA) of liver, bone, and lung tumors; pain blockages, and vertebroplasties. Data were analyzed with respect to scanner settings, overall radiation doses, and individual doses of planning CT series, CT intervention, and control CT series. Results: Eighy-five percent of the total radiation dose was applied during the pre- and post-interventional CT series, leaving only 15% applied by the CT-guided intervention itself. Single slice acquisition was associated with lower doses than continuous CT-fluoroscopy (37 mGy cm vs. 153 mGy cm, p < 0.001). The third quartile of radiation doses varied considerably for different interventions. The highest doses were observed in complex interventions like RFA/MWA of the liver, followed by vertebroplasty and RFA/MWA of the lung. Conclusions: This paper suggests preliminary reference levels for various intervention types and discusses strategies for dose reduction. A multicenter registry of radiation exposure including a broader spectrum of scanners and intervention types is needed to develop definitive reference levels.

  20. Practical CT technology and techniques

    International Nuclear Information System (INIS)

    Berland, L.L.

    1987-01-01

    This handbook equips both radiologists and radiologists in training with a thorough working knowledge of the mechanisms and processes of computed tomography (CT) image generation, the common causes of image artifacts, and useful examination protocols for each area of the body. The author explains the fundamental technological principles of CT, focusing on those concepts crucial to successful CT examinations. The first part of the book succinctly reviews the fundamentals of CT technology. It begins with a methodical introduction to key principles of X-ray physics and technology, in which topics such as the modulation transfer function, magnification, and the X-ray tube are discussed in understandable, nonmathematical terms. The author then explains the basic technology of CT scanners, the principles of scan projection radiography, and the essential rules for radiation dosage determination and radiation protection. Careful attention is given to selectable scan factors in both routine and dynamic scanning, as well as to the processes involved in image creation and refinement and the chief determinants of image quality. Basic and specialized program features and the technology of image display, recording, and storage are also thoroughly described

  1. The meaning of the legislative definition of concept "Law-enforcement agencies" for the qualify of threat or violence according to employee of law-enforcement agency

    OpenAIRE

    Возьний, Володимир Іванович; Тернопільський національний економічний університет

    2014-01-01

    The problems of concept «Law-enforcement agencies» are considered in the article, positions of research workers are resulted. Criminal and legal description of object and victims of corpus delict is given «Threat orviolence according to the worker of law-enforcement agency". В статье рассмотрены проблемы понятия "правоохранительные органы", приведены позициинаучных работников. Дана уголовно-правовая характеристика объекта и потерпевших состава преступления "Угроза или насилие относительно ...

  2. (18)F-FDG PET-CT simulation for non-small-cell lung cancer: effect in patients already staged by PET-CT.

    Science.gov (United States)

    Hanna, Gerard G; McAleese, Jonathan; Carson, Kathryn J; Stewart, David P; Cosgrove, Vivian P; Eakin, Ruth L; Zatari, Ashraf; Lynch, Tom; Jarritt, Peter H; Young, V A Linda; O'Sullivan, Joe M; Hounsell, Alan R

    2010-05-01

    Positron emission tomography (PET), in addition to computed tomography (CT), has an effect in target volume definition for radical radiotherapy (RT) for non-small-cell lung cancer (NSCLC). In previously PET-CT staged patients with NSCLC, we assessed the effect of using an additional planning PET-CT scan for gross tumor volume (GTV) definition. A total of 28 patients with Stage IA-IIIB NSCLC were enrolled. All patients had undergone staging PET-CT to ensure suitability for radical RT. Of the 28 patients, 14 received induction chemotherapy. In place of a RT planning CT scan, patients underwent scanning on a PET-CT scanner. In a virtual planning study, four oncologists independently delineated the GTV on the CT scan alone and then on the PET-CT scan. Intraobserver and interobserver variability were assessed using the concordance index (CI), and the results were compared using the Wilcoxon signed ranks test. PET-CT improved the CI between observers when defining the GTV using the PET-CT images compared with using CT alone for matched cases (median CI, 0.57 for CT and 0.64 for PET-CT, p = .032). The median of the mean percentage of volume change from GTV(CT) to GTV(FUSED) was -5.21% for the induction chemotherapy group and 18.88% for the RT-alone group. Using the Mann-Whitney U test, this was significantly different (p = .001). PET-CT RT planning scan, in addition to a staging PET-CT scan, reduces interobserver variability in GTV definition for NSCLC. The GTV size with PET-CT compared with CT in the RT-alone group increased and was reduced in the induction chemotherapy group.

  3. 18F-FDG PET-CT Simulation for Non-Small-Cell Lung Cancer: Effect in Patients Already Staged by PET-CT

    International Nuclear Information System (INIS)

    Hanna, Gerard G.; McAleese, Jonathan; Carson, Kathryn J.; Stewart, David P.; Cosgrove, Vivian P.; Eakin, Ruth L.; Zatari, Ashraf; Lynch, Tom; Jarritt, Peter H.; Young, V.A. Linda D.C.R.; O'Sullivan, Joe M.

    2010-01-01

    Purpose: Positron emission tomography (PET), in addition to computed tomography (CT), has an effect in target volume definition for radical radiotherapy (RT) for non-small-cell lung cancer (NSCLC). In previously PET-CT staged patients with NSCLC, we assessed the effect of using an additional planning PET-CT scan for gross tumor volume (GTV) definition. Methods and Materials: A total of 28 patients with Stage IA-IIIB NSCLC were enrolled. All patients had undergone staging PET-CT to ensure suitability for radical RT. Of the 28 patients, 14 received induction chemotherapy. In place of a RT planning CT scan, patients underwent scanning on a PET-CT scanner. In a virtual planning study, four oncologists independently delineated the GTV on the CT scan alone and then on the PET-CT scan. Intraobserver and interobserver variability were assessed using the concordance index (CI), and the results were compared using the Wilcoxon signed ranks test. Results: PET-CT improved the CI between observers when defining the GTV using the PET-CT images compared with using CT alone for matched cases (median CI, 0.57 for CT and 0.64 for PET-CT, p = .032). The median of the mean percentage of volume change from GTV CT to GTV FUSED was -5.21% for the induction chemotherapy group and 18.88% for the RT-alone group. Using the Mann-Whitney U test, this was significantly different (p = .001). Conclusion: PET-CT RT planning scan, in addition to a staging PET-CT scan, reduces interobserver variability in GTV definition for NSCLC. The GTV size with PET-CT compared with CT in the RT-alone group increased and was reduced in the induction chemotherapy group.

  4. The use of fused PET/CT images for patient selection and radical radiotherapy target volume definition in patients with non-small cell lung cancer: Results of a prospective study with mature survival data

    International Nuclear Information System (INIS)

    Mac Manus, Michael P.; Everitt, Sarah; Bayne, Mike; Ball, David; Plumridge, Nikki; Binns, David; Herschtal, Alan; Cruickshank, Deborah; Bressel, Mathias; Hicks, Rodney J.

    2013-01-01

    Background and purpose: This prospective study investigated the impact of radiotherapy (RT)-planning FDG-PET/CT on management of non-small cell lung cancer (NSCLC). Materials and methods: Patients still eligible for radical RT after conventional staging underwent RT-planning PET/CT and, if disease was still treatable to 60 Gy, they entered our planning study, where visually-contoured tumour volumes derived with and without PET information were compared. If PET/CT detected advanced disease, palliative therapy was given. Overall survival (OS) for palliative and curative patients was compared. Results: Of 76 eligible patients, only 50 (66%) received radical chemoRT after PET/CT while 26 (34%) received palliative therapies because PET/CT detected advanced disease. Without PET, FDG-avid tumour would reside outside the planning target volume (PTV) in 36% of radical cases and in 25% 95% prescribed dose. OS for all patients was 56.8% and 24.9% at 1 and 4 years, respectively. OS for patients given chemoRT was 77.5% and 35.6% at 1 and 4 years, respectively and was 32% for stage IIIA patients at 4 years. OS for patients treated palliatively was inferior (P < 0.001); 16.3% and 4.1% at 1 and 4 years, respectively. Conclusions: Planning PET/CT frequently changed management and was associated with excellent survival. Survival data from this study were presented in part at the 2011 World Lung Cancer Conference, Amsterdam and planning data at the 2010 Annual Scientific Meeting of the American Society for Therapeutic Radiology and Oncology, Chicago

  5. Indeterminate lesions on planar bone scintigraphy in lung cancer patients: SPECT, CT or SPECT-CT?

    International Nuclear Information System (INIS)

    Sharma, Punit; Kumar, Rakesh; Singh, Harmandeep; Bal, Chandrasekhar; Malhotra, Arun; Julka, Pramod Kumar; Thulkar, Sanjay

    2012-01-01

    The objective of the present study was to compare the role of single photon emission computed tomography (SPECT), computed tomography (CT) and SPECT-CT of selected volume in lung cancer patients with indeterminate lesions on planar bone scintigraphy (BS). The data of 50 lung cancer patients (53 ± 10.3 years; range 30-75; male/female 38/12) with 65 indeterminate lesions on planar BS (January 2010 to November 2010) were retrospectively evaluated. All of them underwent SPECT-CT of a selected volume. SPECT, CT and SPECT-CT images were independently evaluated by two experienced readers (experience in musculoskeletal imaging, including CT: 5 and 7 years) in separate sessions. A scoring scale of 1 to 5 was used, in which 1 is definitely metastatic, 2 is probably metastatic, 3 is indeterminate, 4 is probably benign and 5 is definitely benign. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each modality, taking a score ≤2 as metastatic. With receiver operating characteristic (ROC) curve analysis, areas under the curve (AUC) were calculated for each modality and compared. Clinical and imaging follow-up and/or histopathology were taken as reference standard. For both readers SPECT was inferior to CT (P = 0.004, P = 0.022) and SPECT-CT (P = 0.003, P = 0.037). However, no significant difference was found between CT and SPECT-CT for reader 1 (P = 0.847) and reader 2 (P = 0.592). The findings were similar for lytic as well as sclerotic lesions. Moderate inter-observer agreement was seen for SPECT images (κ = 0.426), while almost perfect agreement was seen for CT (κ = 0.834) and SPECT-CT (κ = 0.971). CT alone and SPECT-CT are better than SPECT for accurate characterisation of indeterminate lesions on planar BS in lung cancer patients. CT alone is not inferior to SPECT-CT for this purpose and might be preferred because of shorter acquisition time and wider availability. (orig.)

  6. VSCE technology definition study

    Science.gov (United States)

    Howlett, R. A.; Hunt, R. B.

    1979-01-01

    Refined design definition of the variable stream control engine (VSCE) concept for advanced supersonic transports is presented. Operating and performance features of the VSCE are discussed, including the engine components, thrust specific fuel consumption, weight, noise, and emission system. A preliminary engine design is presented.

  7. TO THE DEFINITION OF THE CONCEPT OF "FATHERHOOD" Определимся с понятием «Отцовство»

    OpenAIRE

    Nekrasov S. D.; Ryabikina Z. I.; Tivodar A. R.

    2013-01-01

    The article gives the theoretical analysis of the con-ceptual field of the "Fatherhood as a component of self-consciousness of modern man" problem. We have revealed the complexity of the definition of the concept of "Fatherhood" and its structuring. We have also identified four emerging awareness of the "Fatherhood" status of a man

  8. CONCEPT OF MOBILE LEARNING

    Directory of Open Access Journals (Sweden)

    Г О Дуйсеева

    2016-12-01

    Full Text Available This article deals with the definition and the description of mobile learning. Ten years’ experience of the latest mobile technologies use and devices in educational process abroad is analyzed. Prospects and the possibilities of application of these technologies are considered. The basic concepts and development of mobile learning which proposed by scientists for the last years have been given.

  9. DEFINICIONES PERSONALES Y ASPECTOS ESTRUCTURALES DEL CONCEPTO DE LÍMITE FINITO DE UNA FUNCIÓN EN UN PUNTO (Personal Definitions and Structural Aspects of the Concept of Finite Limit of a Function at one Point

    Directory of Open Access Journals (Sweden)

    Juan Francisco Ruiz-Hidalgo

    2013-03-01

    Full Text Available Describimos e interpretamos las definiciones aportadas por un grupo de estudiantes de bachillerato sobre el concepto de límite finito de una función en un punto en términos de aspectos estructurales, compilados y sintetizados de investigaciones previas. Los aspectos estructurales son la interpretación como objeto o como proceso de la noción de límite, los algoritmos y las destrezas prácticas para su cálculo, su alcanzabilidad y su rebasabilidad. A partir de ellos, analizamos las definiciones recogidas. Entre los resultados, destacamos la riqueza de significado de estas definiciones por razón del carácter no alcanzable y no rebasable atribuido al límite y por su consideración dual como objeto o proceso. We describe and interpret the individual definitions of a group of non-compulsory secondary education students related to the concept of finite limit of a function at one point in terms of structural aspects compiled and synthesized from prior research. These aspects are the interpretation of the limit notion as an object or a process, its exact or approximate character, the algorithms and practical skills for its calculation, its reachability and its possibility of being exceeded. Among the results we point out the richness of meaning from these definitions by the not reachable and not exceedable attributed character of the limit, and also by the dual consideration of the limit as an object or process.

  10. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses special ... the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  11. Clinical values of CT and dynamic CT in brain infarction

    International Nuclear Information System (INIS)

    Lim, Soo Il; Jang, Do; Seo, Eun Joo; Sohn, Myung Hee; Choi, Ki Chul

    1985-01-01

    With the advent of faster scan time and new computer program, a scanning technique called 'dynamic computed tomography' has become possible. Dynamic computed tomography consisted of performing multiple rapid sequence scans after injection of contrast material. The authors have evaluated the clinical usefulness of computed tomography and dynamic computed tomography of 93 patients with brain infarction and/or ischemia during the period of 17 months from April 1983 to August 1984 in Department of Radiology, Chonbuk National University Hospital. The results were as follows; 1. The age distribution ranged from 18 years to 78 years. Among them the most common age group was between 50 years and 59 years (40.9%). 2. The sites of brain infarction were cerebral lobes (63 cases,68), basal ganglia (15 cases, 16.1%) and multiple sites (6 cases, 6.4%). The common affected site was middle cerebral artery territories. 3. The contrast enhancement of acute infarction was noted in 14 cases (17.5%) which occurred commonly between 3 days and 2 weeks from ictus. 4. The patterns of time-density curve in brain infarction and/or ischemia were as follow: a. Depression of slow wash-in phase was 20 cases (59%). b. Lower peak concentration was 17 cases (50%). c. Lower and delayed peak concentration was 7 cases (21%). d. No definite peak concentration was 6 cases (18%). First three patterns of time-density curve were thought as relatively characteristic curve of brain infarction and/or ischemia. 5. Two cases that showed negative findings on precontrast CT scan appeared to be positive findings as hypodensity on postcontrast CT scan and were confirmed as brain infarction by dynamic CT. 6. The diagnostic entity of dynamic CT scan were as follows; a. large artery thrombotic infarction were 23 cases (58%). b. lacnar infarction were 6 cases (15%). c. ischemia were 5 cases (13%). d. normal were 5 cases (13%). In six cases of lacunar infarction which was double hypodensity on pre-and postcontrast CT

  12. Clinical values of CT and dynamic CT in brain infarction

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Soo Il; Jang, Do; Seo, Eun Joo; Sohn, Myung Hee; Choi, Ki Chul [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

    1985-04-15

    With the advent of faster scan time and new computer program, a scanning technique called 'dynamic computed tomography' has become possible. Dynamic computed tomography consisted of performing multiple rapid sequence scans after injection of contrast material. The authors have evaluated the clinical usefulness of computed tomography and dynamic computed tomography of 93 patients with brain infarction and/or ischemia during the period of 17 months from April 1983 to August 1984 in Department of Radiology, Chonbuk National University Hospital. The results were as follows; 1. The age distribution ranged from 18 years to 78 years. Among them the most common age group was between 50 years and 59 years (40.9%). 2. The sites of brain infarction were cerebral lobes (63 cases,68), basal ganglia (15 cases, 16.1%) and multiple sites (6 cases, 6.4%). The common affected site was middle cerebral artery territories. 3. The contrast enhancement of acute infarction was noted in 14 cases (17.5%) which occurred commonly between 3 days and 2 weeks from ictus. 4. The patterns of time-density curve in brain infarction and/or ischemia were as follow: a. Depression of slow wash-in phase was 20 cases (59%). b. Lower peak concentration was 17 cases (50%). c. Lower and delayed peak concentration was 7 cases (21%). d. No definite peak concentration was 6 cases (18%). First three patterns of time-density curve were thought as relatively characteristic curve of brain infarction and/or ischemia. 5. Two cases that showed negative findings on precontrast CT scan appeared to be positive findings as hypodensity on postcontrast CT scan and were confirmed as brain infarction by dynamic CT. 6. The diagnostic entity of dynamic CT scan were as follows; a. large artery thrombotic infarction were 23 cases (58%). b. lacnar infarction were 6 cases (15%). c. ischemia were 5 cases (13%). d. normal were 5 cases (13%). In six cases of lacunar infarction which was double hypodensity on pre

  13. Initial experience with FDG-PET/CT in the evaluation of breast cancer

    International Nuclear Information System (INIS)

    Tatsumi, Mitsuaki; Cohade, Christian; Mourtzikos, Karen A.; Wahl, Richard L.; Fishman, Elliot K.

    2006-01-01

    We retrospectively reviewed FDG-PET/CT images in patients with breast cancer to determine whether PET/CT improved the level of diagnostic confidence as compared with PET and to compare PET/CT and CT findings at the location of suspected malignancies. The study included 75 patients with known breast cancer. The initial PET/CT study for each patient was retrospectively reviewed to determine whether improved diagnostic confidence (IDC) regarding lesion localization and characterization was observed with PET/CT as compared with PET alone. PET/CT and CT findings were compared regarding lesion characterization and staging in 69 of the 75 patients, and in the case of discordant findings, comparison with histological or informative follow-up results was also performed. Fifty of the 75 patients exhibited increased FDG uptake in a total of 95 regions. In the comparison of PET/CT and PET, PET/CT resulted in IDC in 30 (60%) of these 50 patients and in 52 (55%) of the 95 regions. In the comparison between PET/CT and CT in 69 patients, PET/CT demonstrated a significantly better accuracy than CT (P<0.05). PET/CT showed definitely positive findings in 60 regions with malignancies, among which CT exhibited positive findings in 43 (72%). PET/CT and CT accurately staged 59 (86%) and 53 (77%) of the 69 patients, respectively. (orig.)

  14. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  15. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Abdomen and Pelvis Computed tomography (CT) of the abdomen and pelvis is a ... is CT Scanning of the Abdomen/Pelvis? Computed tomography, more commonly known as a CT or CAT ...

  16. CT of sella after pituitary surgery

    International Nuclear Information System (INIS)

    Frank, W.; Imhof, H.; Schratter, M.; Knosp, E.

    1986-01-01

    A CT control scan of 32 patients after transsphenoidal resection of a pituitary tumour revealed sellar contents of different density and varying extent. Additional criteria were used to differentiate the intrasellar structures (size, extent, shape, structure, contrast enhancement, bone changes). CT made the definite diagnosis in 6 patients with pituitary tumour recurrence. Hormonal measurements were superior to CT in identifying recurrent tumours in another 3 patients. It is concluded that hormonal methods should be used in evaluating patients after surgery of a hormone-producing tumour. However, CT is the most useful method in detecting tumour recurrence in patients with non-functioning adenomas, and, if an adequate technique is used (coronal scanning, iv-contrast), even clinical asymptomatic tumours can be identified. (orig.) [de

  17. Three-dimensional reconstruction of CT images

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Toshiaki; Kattoh, Keiichi; Kawakami, Genichiroh; Igami, Isao; Mariya, Yasushi; Nakamura, Yasuhiko; Saitoh, Yohko; Tamura, Koreroku; Shinozaki, Tatsuyo

    1986-09-01

    Computed tomography (CT) has the ability to provide sensitive visualization of organs and lesions. Owing to the nature of CT to be transaxial images, a structure which is greater than a certain size appears as several serial CT images. Consequently each observer must reconstruct those images into a three-dimensional (3-D) form mentally. It has been supposed to be of great use if such a 3-D form can be described as a definite figure. A new computer program has been developed which can produce 3-D figures from the profiles of organs and lesions on CT images using spline curves. The figures obtained through this method are regarded to have practical applications.

  18. 18F-FDG PET/CT-based gross tumor volume definition for radiotherapy in head and neck Cancer: a correlation study between suitable uptake value threshold and tumor parameters

    International Nuclear Information System (INIS)

    Kao, Chia-Hung; Hsieh, Te-Chun; Yu, Chun-Yen; Yen, Kuo-Yang; Yang, Shih-Neng; Wang, Yao-Ching; Liang, Ji-An; Chien, Chun-Ru; Chen, Shang-Wen

    2010-01-01

    To define a suitable threshold setting for gross tumor volume (GTV) when using 18 Fluoro-deoxyglucose positron emission tomography and computed tomogram (PET/CT) for radiotherapy planning in head and neck cancer (HNC). Fifteen HNC patients prospectively received PET/CT simulation for their radiation treatment planning. Biological target volume (BTV) was derived from PET/CT-based GTV of the primary tumor. The BTVs were defined as the isodensity volumes when adjusting different percentage of the maximal standardized uptake value (SUVmax), excluding any artifact from surrounding normal tissues. CT-based primary GTV (C-pGTV) that had been previously defined by radiation oncologists was compared with the BTV. Suitable threshold level (sTL) could be determined when BTV value and its morphology using a certain threshold level was observed to be the best fitness of the C-pGTV. Suitable standardized uptake value (sSUV) was calculated as the sTL multiplied by the SUVmax. Our result demonstrated no single sTL or sSUV method could achieve an optimized volumetric match with the C-pGTV. The sTL was 13% to 27% (mean, 19%), whereas the sSUV was 1.64 to 3.98 (mean, 2.46). The sTL was inversely correlated with the SUVmax [sTL = -0.1004 Ln (SUVmax) + 0.4464; R 2 = 0.81]. The sSUV showed a linear correlation with the SUVmax (sSUV = 0.0842 SUVmax + 1.248; R 2 = 0.89). The sTL was not associated with the value of C-pGTVs. In PET/CT-based BTV for HNC, a suitable threshold or SUV level can be established by correlating with SUVmax rather than using a fixed threshold

  19. Radiotherapy and the importance of CT for the nasopharyngeal squammous cell carcinoma, 1

    International Nuclear Information System (INIS)

    Yamashita, Shoji; Dokiya, Takushi.

    1987-01-01

    Thirty-five patients with nasopharyngeal squamous cell carcinoma (NPC) were examined with computed tomography (CT) before definitive radiotherapy. CT clearly delincated the extent of the primary tumors. CT frequently showed subtle destruction of the paranasal sinuses and pterygoid plate, which was not usually detected by conventional X-ray examinations. T-staging was made according to the UICC TNM classification system (1978), depending on the clinical findings and the conventional X-ray examinations (non-CT T-stage). Then the non-CT T-stage of each patient was compared with T-stage diagnosed with CT findings alone (CT T-stage). CT upstaged non-CT T-stage in 14 of the 35 patients. Only one patient was downstaged by CT ; this patient had cranial nerve palsy but no detectable bone destruction as shown by CT. Since CT can reveal both bones and abnormal soft tissues well, it is a very useful diagnostic tool for the staging of the tumor assessment of treatment planning. Before radiotherapy, we should use CT to confirm that whether the tumor was located within the radiation field. CT is also useful to see the tumor regression after definitive radiotherapy. We conclude that CT is the single, most reliable imaging method for primary tumors of the NPC patients. (author)

  20. Infrastructure: concept, types and value

    Directory of Open Access Journals (Sweden)

    Alexander E. Lantsov

    2013-01-01

    Full Text Available Researches of influence of infrastructure on the economic growth and development of the countries gained currency. However the majority of authors drop the problem of definition of accurate concept of studied object and its criteria out. In the given article various approaches in the definition of «infrastructure» concept, criterion and the characteristics of infrastructure distinguishing it from other capital assets are presented. Such types of infrastructure, as personal, institutional, material, production, social, etc. are considered. Author’s definition of infrastructure is given.

  1. Green economy and related concepts

    NARCIS (Netherlands)

    Loiseau, Eleonore; Saikku, Laura; Antikainen, Riina; Droste, Nils; Hansjürgens, Bernd; Pitkänen, Kati; Leskinen, Pekka; Kuikman, Peter; Thomsen, Marianne

    2016-01-01

    For the last ten years, the notion of a green economy has become increasingly attractive to policy makers. However, green economy covers a lot of diverse concepts and its links with sustainability are not always clear. In this article, we focus on definitions of green economy and related concepts

  2. The niche party concept and its measurement

    OpenAIRE

    Meyer, Thomas M; Miller, Bernhard

    2015-01-01

    The concept of the niche party has become increasingly popular in analyses of party competition. Yet, existing approaches vary in their definitions and their measurement approaches. We propose using a minimal definition that allows us to compare political parties in terms of their ?nicheness?. We argue that the conceptual core of the niche party concept is based on issue emphasis and that a niche party emphasizes policy areas neglected by its rivals. Based on this definition, we propose a con...

  3. Prebiotics: why definitions matter

    Science.gov (United States)

    Hutkins, Robert W; Krumbeck, Janina A; Bindels, Laure B; Cani, Patrice D; Fahey, George; Goh, Yong Jun; Hamaker, Bruce; Martens, Eric C; Mills, David A; Rastal, Robert A; Vaughan, Elaine; Sanders, Mary Ellen

    2015-01-01

    The prebiotic concept was introduced twenty years ago, and despite several revisions to the original definition, the scientific community has continued to debate what it means to be a prebiotic. How prebiotics are defined is important not only for the scientific community, but also for regulatory agencies, the food industry, consumers and healthcare professionals. Recent developments in community-wide sequencing and glycomics have revealed that more complex interactions occur between putative prebiotic substrates and the gut microbiota than previously considered. A consensus among scientists on the most appropriate definition of a prebiotic is necessary to enable continued use of the term. PMID:26431716

  4. Spinal CT scan, 1

    International Nuclear Information System (INIS)

    Nakagawa, Hiroshi

    1982-01-01

    Methods of CT of the cervical and thoracic spines were explained, and normal CT pictures of them were described. Spinal CT was evaluated in comparison with other methods in various spinal diseases. Plain CT revealed stenosis due to spondylosis or ossification of posterior longitudinal ligament and hernia of intervertebral disc. CT took an important role in the diagnosis of spinal cord tumors with calcification and destruction of the bone. CT scan in combination with other methods was also useful for the diagnosis of spinal injuries, congenital anomalies and infections. (Ueda, J.)

  5. Power: towards a third generation definition

    OpenAIRE

    13250612 - Zaaiman, Stephanus Johannes

    2008-01-01

    Power is a well-established concept in the social sciences especially in the political sciences. Although it is widely used in scientific discourse, different definitions and perspectives prevail with regard to it. This article aims to explore the possibilities of taking the debate further towards a third generation definition of social power. Although first generation definitions (associated with Weber and Dahl) and second generation definitions (associated with inter alia Giddens and Morris...

  6. Capturing design knowledge in formal concept definitions

    NARCIS (Netherlands)

    Leeuwen, van J.P.; Vries, de B.; Timmermans, H.J.P.; Vries, de B.

    2000-01-01

    For support of creativity in architectural design, design systems must be provided with information models that are flexible enough to follow the dynamic way of designers in handling early design information. This paper discusses a framework for information modelling using Features that answers this

  7. Overview of IMRT - definitions and basic concepts

    International Nuclear Information System (INIS)

    Mackie, T.R.

    2008-01-01

    A detailed advanced outline of the title topic is presented. Summary is formulated as follows: (i) Conventional MLC, developed for block replacement, require corrections and careful QA when when used for IMRT; (ii) There are both advantages and disadvantages of static or dynamic MLC delivery; (iii) Tomotherapy uses binary MLC systems specifically designed for IMRT; (iv) There are two types of optimization, grid of beamlets and direct aperture methods; (v) Optimization is controlled by objective functions. (P.A.)

  8. Definition of a European promotion concept

    Science.gov (United States)

    Andersen, T. A. E.; Blume, H. T.; Brouwer, M. P. A. M.; Dangelo, L.; Duwe, H.; Eilersen, N.; Gaida, M.; Herten, M.; Iversen, T.-H.; Jungius, C.

    1992-07-01

    A marketing strategy for the services offered by the Columbus program is presented. The marketing goals, activities and means, and the procedures for monitoring and control are defined within the context of a first tentative marketing plan for Columbus utilization. The proposed organizational structure, based on national user support organizations within Europe, allows as far as possible for a clear coupling of the organization to the market segment.

  9. Basic concepts and definitions of clinical management

    Directory of Open Access Journals (Sweden)

    Angélica Román

    2012-06-01

    Full Text Available Management is leading, administering resources, and achieving the goals and objectives that have been set. In the Chilean health care system, management can be subdivided in three main levels – macro-management, meso-management and micro-management. Managing health care is also about epidemiological changes, information and technology innovations, patient groups demanding better services, but mostly about a huge escalation in costs that is not necessarily substantiated by evidence on more efficiency in health outcomes.Clinical management is more than a management tool. It is a cultural change that will provide new values to professional practice and to the organization as a whole. However, clinical management demands more commitment on behalf of the human teams that need to learn how to lead and to be led. These teams will be called upon to help in the decision-making process for the betterment of the institution.

  10. Liquidity (risk) concepts: definitions and interactions

    OpenAIRE

    Nikolaou, Kleopatra

    2009-01-01

    We discuss the notion of liquidity and liquidity risk within the financial system. We distinguish between three different liquidity types, central bank liquidity, funding and market liquidity and their relevant risks. In order to understand the workings of financial system liquidity, as well as the role of the central bank, we bring together relevant literature from different areas and review liquidity linkages among these three types in normal and turbulent times. We stress that the root of ...

  11. Using SNOMED CT to Represent Two Interface Terminologies

    Science.gov (United States)

    Rosenbloom, S. Trent; Brown, Steven H.; Froehling, David; Bauer, Brent A.; Wahner-Roedler, Dietlind L.; Gregg, William M.; Elkin, Peter L.

    2009-01-01

    Objective Interface terminologies are designed to support interactions between humans and structured medical information. In particular, many interface terminologies have been developed for structured computer based documentation systems. Experts and policy-makers have recommended that interface terminologies be mapped to reference terminologies. The goal of the current study was to evaluate how well the reference terminology SNOMED CT could map to and represent two interface terminologies, MEDCIN and the Categorical Health Information Structured Lexicon (CHISL). Design Automated mappings between SNOMED CT and 500 terms from each of the two interface terminologies were evaluated by human reviewers, who also searched SNOMED CT to identify better mappings when this was judged to be necessary. Reviewers judged whether they believed the interface terms to be clinically appropriate, whether the terms were covered by SNOMED CT concepts and whether the terms' implied semantic structure could be represented by SNOMED CT. Measurements Outcomes included concept coverage by SNOMED CT for study terms and their implied semantics. Agreement statistics and compositionality measures were calculated. Results The SNOMED CT terminology contained concepts to represent 92.4% of MEDCIN and 95.9% of CHISL terms. Semantic structures implied by study terms were less well covered, with some complex compositional expressions requiring semantics not present in SNOMED CT. Among sampled terms, those from MEDCIN were more complex than those from CHISL, containing an average 3.8 versus 1.8 atomic concepts respectively, pterms. PMID:18952944

  12. Using SNOMED CT to represent two interface terminologies.

    Science.gov (United States)

    Rosenbloom, S Trent; Brown, Steven H; Froehling, David; Bauer, Brent A; Wahner-Roedler, Dietlind L; Gregg, William M; Elkin, Peter L

    2009-01-01

    Interface terminologies are designed to support interactions between humans and structured medical information. In particular, many interface terminologies have been developed for structured computer based documentation systems. Experts and policy-makers have recommended that interface terminologies be mapped to reference terminologies. The goal of the current study was to evaluate how well the reference terminology SNOMED CT could map to and represent two interface terminologies, MEDCIN and the Categorical Health Information Structured Lexicon (CHISL). Automated mappings between SNOMED CT and 500 terms from each of the two interface terminologies were evaluated by human reviewers, who also searched SNOMED CT to identify better mappings when this was judged to be necessary. Reviewers judged whether they believed the interface terms to be clinically appropriate, whether the terms were covered by SNOMED CT concepts and whether the terms' implied semantic structure could be represented by SNOMED CT. Outcomes included concept coverage by SNOMED CT for study terms and their implied semantics. Agreement statistics and compositionality measures were calculated. The SNOMED CT terminology contained concepts to represent 92.4% of MEDCIN and 95.9% of CHISL terms. Semantic structures implied by study terms were less well covered, with some complex compositional expressions requiring semantics not present in SNOMED CT. Among sampled terms, those from MEDCIN were more complex than those from CHISL, containing an average 3.8 versus 1.8 atomic concepts respectively, pterms.

  13. Value of CT in the diagnosis of pseudomembranous colitis

    International Nuclear Information System (INIS)

    Fishman, E.K.; Merine, D.S.; Kuhlman, J.E.; Jones, B.

    1989-01-01

    With the increasing use of Ct as a primary imaging modality in the patient with abdominal distress, it is not surprising the CT may be the initial study to suggest the diagnosis of pseudomembranous colitis. The authors reviewed the CT scans in 16 patients with proved pseudomembranous colitis. In 12 of these cases, the diagnosis was not considered prior to CT. The CT findings included wall thickening (average, 18 mm), definite ulcerations (11 cases), ascites (two cases), and pseudoperforation (three cases). The pseudoperforation is caused by the trapping of contrast material within the large ulcerated mucosal folds and can simulate contrast extravasation. The various CT appearances of pseudomembranous colitis are addressed, as well as the potential difficulty in distinguishing it from other types of colitis

  14. Dose optimization in CT examination of children

    International Nuclear Information System (INIS)

    Hojreh, A.; Prosch, H.

    2012-01-01

    Problems arise due to the increased clinical use of computed tomography (CT) and the high radiosensitivity of children. The ALARA concept (as low as reasonably achievable) prevails in pediatric radiology. Justified indications and full utilization of available dose optimization methods. Medical physicists and the manufacturers should support pediatric radiology in the implementation of the ALARA concept. The referring physicians and radiology staff should be integrated into training programs. Sufficient diagnostic image quality is paramount and not the pretty images. (orig.) [de

  15. Evolutionary space platform concept study. Volume 2, part B: Manned space platform concepts

    Science.gov (United States)

    1982-01-01

    Logical, cost-effective steps in the evolution of manned space platforms are investigated and assessed. Tasks included the analysis of requirements for a manned space platform, identifying alternative concepts, performing system analysis and definition of the concepts, comparing the concepts and performing programmatic analysis for a reference concept.

  16. CT diagnosis of thyroid carcinoma

    International Nuclear Information System (INIS)

    Luo Dehong; Shi Mulan; Luo Douqiang

    1998-01-01

    Purpose: To study the CT appearances of thyroid carcinoma and its cervical metastatic lymphadenopathy, as well as to evaluate the diagnostic criteria of tumor invasion of adjacent structures. Methods: CT findings of surgery and pathology proved thyroid carcinoma in 52 patients were analyzed. Results: All of the primary tumor were heterogeneous in density, 32 tumors (82.5%) were ill-defined. Fine granular calcifications were revealed in 11 primary tumors and metastatic lymph nodes in 5 cases. Cystic formation with intracystic high density papillary-like nodules were found in 4 primary tumors and metastatic lymphadenopathy in 5 cases. Trachea, esophagus and carotic artery invasion were proved by surgery in 22, 21 and 10 cases respectively. Serrated inner wall and tumor nodule protrusion into tracheal lumen were the definite signs of trachea invasion. Use tumor encasement over 1/2 of the circumference of esophagus and 1/3 of the circumference of carotid artery as the diagnostic criterion of invasion, sensitivity was 71.4%, 100.0% specificity was 96.3%, 95.2% respectively. Conclusion: Fine granular calcification and cystic formation with high attenuation intracystic papillary-like nodules were characteristic manifestations of primary thyroid carcinoma (especially papillary carcinoma) and its metastatic lymphadenopathy as well. Contrast enhanced CT scan is helpful in the diagnosis of thyroid carcinoma and the delineation of tumor extent, which is very important in surgical planning

  17. Definition of IGRT

    International Nuclear Information System (INIS)

    Lief, Eugene

    2008-01-01

    Two definitions of image-guided radiation therapy (IGRT) are cited: 'Frequent imaging in the treatment room during a course of radiotherapy to guide the treatment process' and 'Any use of planar imaging, volumetric imaging or volumetric cine imaging, marker localization, marker tracking, patient surface imaging or patient surface tracking to improve the precision of radiation-therapy delivery'. Also cited are the sentences 'IGRT refers broadly to treatment delivery using modern imaging methods, such as CT, MRI, PET and Ultrasound, in target and non-target structures and in RT definition, design and delivery...' and 'IGRT includes, but is not limited to, 3DCRT, IMRT: stereotactic radiosurgery, stereotactic RT, and brachytherapy...'. Purposes include: Precise patient positioning; Automatic localization of bony structures or implanted fiducial markers; Imaging and positioning of soft tissue tumors and critical structures; Margin reduction and healthy organ sparing; and Delivering the desired dose distribution. On the negative side are the following factors: Physics staffing at treatment delivery Longer treatment times: 1 min. arm deployment, setup for scan, 1 min. gantry rotation - volume image acquisition, 30 sec. reconstruction (depends on resolution), 30 sec. load CT and CB into registration; Registration: from few sec. to few min.; Feasible if the number of treatments is low. The history of IGRT is mentioned, instrumentation is described using ample photographs, and many applications are shown. (P.A.)

  18. CT appearance of splenosis

    Energy Technology Data Exchange (ETDEWEB)

    Mendelson, D.S.; Cohen, B.A.; Armas, R.R.

    1982-12-01

    Splenosis is an unusual complication of splenic trauma. The computed tomographic (CT) appearance of splenosis is described. One should consider this diagnosis when faced with a history of splenic trauma and multiple round or oval masses at CT.

  19. CT appearance of splenosis

    International Nuclear Information System (INIS)

    Mendelson, D.S.; Cohen, B.A.; Armas, R.R.

    1982-01-01

    Splenosis is an unusual complication of splenic trauma. The computed tomographic (CT) appearance of splenosis is described. One should consider this diagnosis when faced with a history of splenic trauma and multiple round or oval masses at CT

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  2. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... cavities (ventricles) in patients with hydrocephalus . diseases or malformations of the skull. CT scanning is also performed ... biopsy ) from the brain. assess aneurysms or arteriovenous malformations through a technique called CT angiography. For more ...

  4. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  6. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... CT scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector ... Safety page for more information about radiation dose. Women should always inform their physician and x-ray ...

  7. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... preferable over CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder ...

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... CT of the Sinuses? CT is usually the first test ordered when a sinus tumor is suspected. ... Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise in several radiologic ...

  9. Abdominal and Pelvic CT

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    Full Text Available ... CT scanner or may be over the weight limit—usually 450 pounds—for the moving table. CT ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: ...

  10. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... CT scan, an experienced radiologist can diagnose many causes of abdominal pain or injury from trauma with ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  12. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  13. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This ... clinical problems. CT is less sensitive to patient movement than MRI. CT can be performed if you ...

  14. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide ... clicking and whirring sounds as the CT scanner's internal parts, not usually visible to you, revolve around ...

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... about tumors of the nasal cavity and sinuses. plan for surgery by defining anatomy. top of page ... for sinusitis. CT of the sinuses can help plan the safest and most effective surgery. CT of ...

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... Safety Images related to Computed Tomography (CT) - Head Videos related to Computed Tomography (CT) - Head Sponsored by ...

  17. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... related to Computed Tomography (CT) - Abdomen and Pelvis Videos related to Computed Tomography (CT) - Abdomen and Pelvis ...

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the nasal cavity. CT ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  1. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  2. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... of CT Scanning of the Abdomen and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed ... soft tissues and blood vessels. top of page What are some common uses of the procedure? This ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... head CT scanning. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits A CT scan is one of the safest ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  5. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Viewing a CT scan, an experienced radiologist can ... scanning is painless, noninvasive and accurate. A major advantage of CT is its ability to image bone, ...

  6. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces ... particularly the lungs, abdomen, pelvis and bones. A diagnosis determined by CT scanning may eliminate the need ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces ... medical device of any kind, unlike MRI. A diagnosis determined by CT scanning may eliminate the need ...

  8. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT scanning. top of page Additional Information and Resources RTAnswers.org: Radiation Therapy for Bladder Cancer Radiation ... Image Gallery Patient undergoing computed tomography (CT) scan View full size with caption Pediatric Content Some imaging ...

  9. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT) of the abdomen and pelvis is a diagnostic imaging test used to help detect diseases of ... as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces ...

  10. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... benefits vs. risks? Benefits A CT scan is one of the safest means of studying the sinuses. ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... sometimes compared to looking into a loaf of bread by cutting the loaf into thin slices. When ... actual CT scanning is performed. Depending on the type of CT scan, the machine may make several ...

  12. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging ...

  13. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... can be performed if you have an implanted medical device of any kind, unlike MRI. CT imaging ...

  14. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  15. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Viewing a CT scan, an experienced radiologist ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  16. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits A CT scan is one of the ... CT scans should have no immediate side effects. Risks There is always a slight chance of cancer ...

  17. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... membranes covering the brain. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Brain ...

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... scanners to obtain multiple slices in a single rotation. These scanners, called multislice CT or multidetector CT, ... for the moving table. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Head ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Stroke Brain Tumors Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... air-filled spaces within the bones of the face surrounding the nasal cavity. CT scanning is painless, ... and blood vessels. A CT scan of the face produces images that also show a patient's paranasal ...

  1. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  3. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT scanner is typically a large, box-like machine with a hole, or short tunnel, in the ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  5. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  6. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending ...

  7. CT of the knee

    International Nuclear Information System (INIS)

    Ghelman, B.

    1987-01-01

    CT can be combined with arthrography of the knee to study the following abnormalities: meniscal tears and cysts, synovial plicae, chondromalacia patellae, and osteochondritis dissecans. The CT-arthrogram images present abnormalities in a manner that resembles the ''in situ'' surgical findings, allowing management decisions to be made with greater confidence. The CT techniques for imaging the knee after arthrography are discussed, as is the use of plain CT

  8. ITER definition phase

    International Nuclear Information System (INIS)

    1989-01-01

    The International Thermonuclear Experimental Reactor (ITER) is envisioned as a fusion device which would demonstrate the scientific and technological feasibility of fusion power. As a first step towards achieving this goal, the European Community, Japan, the Soviet Union, and the United States of America have entered into joint conceptual design activities under the auspices of the International Atomic Energy Agency. A brief summary of the Definition Phase of ITER activities is contained in this report. Included in this report are the background, objectives, organization, definition phase activities, and research and development plan of this endeavor in international scientific collaboration. A more extended technical summary is contained in the two-volume report, ''ITER Concept Definition,'' IAEA/ITER/DS/3. 2 figs, 2 tabs

  9. Helical CT in acute lower gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Ernst, Olivier; Leroy, Christophe; Sergent, Geraldine; Bulois, Philippe; Saint-Drenant, Sophie; Paris, Jean-Claude

    2003-01-01

    The purpose of this study was to assess the usefulness of helical CT in depicting the location of acute lower gastrointestinal bleeding. A three-phase helical CT of the abdomen was performed in 24 patients referred for acute lower gastrointestinal bleeding. The diagnosis of the bleeding site was established by CT when there was at least one of the following criteria: spontaneous hyperdensity of the peribowel fat; contrast enhancement of the bowel wall; vascular extravasation of the contrast medium; thickening of the bowel wall; polyp or tumor; or vascular dilation. Diverticula alone were not enough to locate the bleeding site. The results of CT were compared with the diagnosis obtained by colonoscopy, enteroscopy, or surgery. A definite diagnosis was made in 19 patients. The bleeding site was located in the small bowel in 5 patients and the colon in 14 patients. The CT correctly located 4 small bowel hemorrhages and 11 colonic hemorrhages. Diagnosis of the primary lesion responsible for the bleeding was made in 10 patients. Our results suggest that helical CT could be a good diagnostic tool in acute lower gastrointestinal bleeding to help the physician to diagnose the bleeding site. (orig.)

  10. Teamwork: a concept analysis.

    Science.gov (United States)

    Xyrichis, Andreas; Ream, Emma

    2008-01-01

    This paper is a report of an analysis of the concept of teamwork. Teamwork is seen as an important facilitator in delivering quality healthcare services internationally. However, research studies of teamwork in health care are criticized for lacking a basic conceptual understanding of what this concept represents. A universal definition for healthcare settings and professionals is missing from published literature. Walker and Avant's approach was used to guide this concept analysis. Literature searches used bibliographic databases (Medline, CINAHL, Web of Science, Proquest CSA), internet search engines (GoogleScholar), and hand searches. Literature published between 1976 and 2006 was reviewed but only material in English was included. Based on the analysis undertaken, teamwork is proposed as a dynamic process involving two or more healthcare professionals with complementary backgrounds and skills, sharing common health goals and exercising concerted physical and mental effort in assessing, planning, or evaluating patient care. This is accomplished through interdependent collaboration, open communication and shared decision-making, and generates value-added patient, organizational and staff outcomes. Praising the value of teamwork without a common understanding of what this concept represents endangers both research into this way of working and its effective utilization in practice. The proposed definition helps reconcile discrepancies between how this concept is understood by nurses and doctors, as well as allied health professionals. A common understanding can facilitate communication in educational, research and clinical settings and is imperative for improving clarity and validity of future research.

  11. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) ... are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a ...

  12. Loneliness: a concept analysis.

    Science.gov (United States)

    Bekhet, Abir K; Zauszniewski, Jaclene A; Nakhla, Wagdy E

    2008-01-01

    Loneliness is a universal human experience recognized since the dawn of time, yet it is unique for every individual. Loneliness can lead to both depression and low self-esteem. This article explicates the concept of loneliness through the examination of its conceptual definition and uses, defining attributes, related concepts, and empirical referents. Literature review using hand search and database were used as sources of information. Because loneliness is commonly encountered in nursing situations, the information provided will serve as a framework for assessment, planning, intervention, and evaluation of clients.

  13. Who and Racist criteria on CT

    International Nuclear Information System (INIS)

    Servente, L.

    2012-01-01

    This presentation is about Who and Recist criteria on CT.These are rules to the evaluation of the solid tumors treatment response as well as different concepts of measurability criteria of blastic changes, target /non target lesions, adenopathies, lytic, cystic , non-measurable disease and progressive lesions

  14. CT of laryngotracheal trauma

    International Nuclear Information System (INIS)

    Lupetin, A.R.; Daffner, R.H.

    1991-01-01

    This paper evaluates the usefulness of CT for the diagnosis of traumatic laryngotracheal abnormalities. The authors retrospectively evaluated the neck CT studies of 50 patients (36 males, 14 females; age range, 16-75 years) who presented to a level I trauma center after suffering a blunt or penetrating laryngotracheal injury. CT results were correlated with endoscopic or surgical findings in 43 cases. Three groups emerge. CT positive: hyloid bone or laryngotracheal cartilage injury; CT positive: soft-tissue injury only; and CT negative. In group 1, CT demonstrated all bony or cartilaginous injuries proved at surgery or suggested at endoscopy. CT failed to demonstrate laryngotracheal separation in 1 case. In group 2, CT demonstrated all soft-tissue injuries suggested at endoscopy. In group 3, CT findings agreed with those of endoscopy in 7 cases, but minor soft-tissue findings seen at endoscopy were missed in 3 cases. Seven patients were studied only with CT. Ct is an accurate technique for detecting bony or cartilaginous laryngotracheal traumatic abnormalities. However, laryngotracheal separation and minor soft-tissue injuries can be missed

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

  17. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  19. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... vessels. CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT is less sensitive to patient movement ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography ( ...

  1. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT ...

  2. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems. CT ...

  4. The Logic of Definition

    Science.gov (United States)

    2009-05-01

    Wittgenstein , in his Philosophical Investigations (1953), observed that, for many phenomena, there are no necessary conditions common to all members of... Wittgenstein 1953: §66, p.27e). Wittgenstein refers to these overlapping similarities as “family resemblances” (Ibid., §67, p.27e). Few, if any, of...that is, we may resort to stipulative definition). But this is not necessary for the concept to be usable. Indeed, as Wittgenstein says, sometimes

  5. Evaluation of CT findings for diagnosis of pleural effusions

    International Nuclear Information System (INIS)

    Arenas-Jimenez, J.; Alonso-Charterina, S.; Fernandez-Latorre, F.; Gil-Sanchez, S.; Sanchez-Paya, J.; Lloret-Llorens, M.

    2000-01-01

    Computed tomography studies are usually used to assess patients with pleural effusions, and radiologists should be aware of the significance of different CT findings for the diagnosis of the effusion. The purpose of this study was to evaluate CT findings for etiological diagnosis of pleural effusions. Contrast-enhanced CT of the chest of 211 patients with pleural effusion of definite diagnosis were evaluated. The CT images were evaluated for the presence and extent of pleural effusion, thickening or nodules, extrapleural fat and other changes in the mediastinum or lung. The CT scans were read by two independent observers and correlation between them was evaluated. Comparison of CT findings between benign and malignant effusions, between exudates and transudates, and between empyemas and the other parapneumonic effusions were carried out. Kappa values for most CT findings were >0.85. Loculation, pleural thickening, pleural nodules, and extrapleural fat of increased density were only present in exudative effusions. Multiple pleural nodules and nodular pleural thickening were the only pleural findings limited to malignant pleural effusions. The signs were also more frequently seen in empyemas than in other parapneumonic effusions. Computed tomography findings can help to distinguish between transudates and exudates. Although there is some overlap between benign and malignant pleural effusions, pleural nodules and nodular pleural thickening were present almost exclusively in the latter. Although differences between CT findings of empyemas and the other parapneumonic effusions exist, there is no finding which can definitely differentiate between them. (orig.)

  6. Concepts of formal concept analysis

    Science.gov (United States)

    Žáček, Martin; Homola, Dan; Miarka, Rostislav

    2017-07-01

    The aim of this article is apply of Formal Concept Analysis on concept of world. Formal concept analysis (FCA) as a methodology of data analysis, information management and knowledge representation has potential to be applied to a verity of linguistic problems. FCA is mathematical theory for concepts and concept hierarchies that reflects an understanding of concept. Formal concept analysis explicitly formalizes extension and intension of a concept, their mutual relationships. A distinguishing feature of FCA is an inherent integration of three components of conceptual processing of data and knowledge, namely, the discovery and reasoning with concepts in data, discovery and reasoning with dependencies in data, and visualization of data, concepts, and dependencies with folding/unfolding capabilities.

  7. Marketing cardiac CT programs.

    Science.gov (United States)

    Scott, Jason

    2010-01-01

    There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

  8. LD Definition.

    Science.gov (United States)

    Learning Disability Quarterly, 1987

    1987-01-01

    The position paper (1981) of the National Joint Committee on Learning Disabilities presents a revised definition of learning disabilities and identifies issues and concerns (such as the limitation to children and the exclusion clause) associated with the definition included in P.L. 94-142, the Education for All Handicapped Children Act. (DB)

  9. Dose reduction strategies for cardiac CT

    International Nuclear Information System (INIS)

    Midgley, S.M.; Einsiedel, P.; Langenberg, F.; Lui, E.

    2010-01-01

    Full text: Recent advances in CT technology have produced brighter X-ray sources. gantries capable of increased rotation speeds, faster scintil lation materials arranged into multiple rows of detectors, and associated advances in 3D reconstruction methods. These innovations have allowed multi-detector CT to be turned to the diagnosis of cardiac abnormalities and compliment traditional imaging techniques such as coronary angiography. This study examines the cardiac imaging solution offered by the Siemens Somatom Definition Dual Source 64 slice CT scanner. Our dose reduction strategies involve optimising the data acquisition protocols according to diagnostic task, patient size and heart rate. The relationship between scan parameters, image quality and patient dose is examined and verified against measurements with phantoms representing the standard size patient. The dose reduction strategies are reviewed with reference to survey results of patient dose. Some cases allow the insertion of shielding to protect radiosensitive organs, and results are presented to quantify the dose saving.

  10. The sensitivity of computed tomography (CT) scans in detecting trauma: are CT scans reliable enough for courtroom testimony?

    Science.gov (United States)

    Molina, D Kimberley; Nichols, Joanna J; Dimaio, Vincent J M

    2007-09-01

    Rapid and accurate recognition of traumatic injuries is extremely important in emergency room and surgical settings. Emergency departments depend on computed tomography (CT) scans to provide rapid, accurate injury assessment. We conducted an analysis of all traumatic deaths autopsied at the Bexar County Medical Examiner's Office in which perimortem medical imaging (CT scan) was performed to assess the reliability of the CT scan in detecting trauma with sufficient accuracy for courtroom testimony. Cases were included in the study if an autopsy was conducted, a CT scan was performed within 24 hours before death, and there was no surgical intervention. Analysis was performed to assess the correlation between the autopsy and CT scan results. Sensitivity, specificity, positive predictive value, and negative predictive value were defined for the CT scan based on the autopsy results. The sensitivity of the CT scan ranged from 0% for cerebral lacerations, cervical vertebral body fractures, cardiac injury, and hollow viscus injury to 75% for liver injury. This study reveals that CT scans are an inadequate detection tool for forensic pathologists, where a definitive diagnosis is required, because they have a low level of accuracy in detecting traumatic injuries. CT scans may be adequate for clinicians in the emergency room setting, but are inadequate for courtroom testimony. If the evidence of trauma is based solely on CT scan reports, there is a high possibility of erroneous accusations, indictments, and convictions.

  11. Clinical study of retrocaval ureter diagnosed by CT scan

    International Nuclear Information System (INIS)

    Kiriyama, Isao; Hata, Ryosuke; Amemiya, Hiroshi

    1987-01-01

    Although retrocaval ureter is relatively uncommon congenital anomaly, surgical intervention is often necessary to alleviate the clinical signs and symptoms of the patients. Vena cavography has been indispensable imaging modality for the definitive diagnosis of this anomaly. Recently, however, CT scan in addition to excretory urography (IVP) and retrograde pyelography(RP) has been utilized in many reported cases in the diagnosis of retrocaval ureter. We have experienced 3 cases of retrocaval ureter consecutively. In this paper we report these 3 cases of retrocaval ureter, in which CT scan enabled us to confirm the definitive diagnosis. We also report another case of pelviureteric stenosis that was taken for retrocaval ureter by CT scan. Causes of the misdiagnosis is discussed. In conclusion CT scan is useful diagnostic modality in the diagnosis of retrocaval ureter and this lesser invasive technique might lessen the need for vena cavography. (author)

  12. Radiation exposure during CT-guided biopsies: recent CT machines provide markedly lower doses.

    Science.gov (United States)

    Guberina, Nika; Forsting, Michael; Ringelstein, Adrian; Suntharalingam, Saravanabavaan; Nassenstein, Kai; Theysohn, Jens; Wetter, Axel

    2018-03-28

    To examine radiation dose levels of CT-guided interventional procedures of chest, abdomen, spine and extremities on different CT-scanner generations at a large multicentre institute. 1,219 CT-guided interventional biopsies of different organ regions ((A) abdomen (n=516), (B) chest (n=528), (C) spine (n=134) and (D) extremities (n=41)) on different CT-scanners ((I) SOMATOM-Definition-AS+, (II) Volume-Zoom, (III) Emotion6) were included from 2013-2016. Important CT-parameters and standard dose-descriptors were retrospectively examined. Additionally, effective dose and organ doses were calculated using Monte-Carlo simulation, following ICRP103. Overall, radiation doses for CT interventions are highly dependent on CT-scanner generation: the newer the CT scanner, the lower the radiation dose imparted to patients. Mean effective doses for each of four procedures on available scanners are: (A) (I) 9.3mSv versus (II) 13.9mSv (B) (I) 7.3mSv versus (III) 11.4mSv (C) (I) 6.3mSv versus (II) 7.4mSv (D) (I) 4.3mSv versus (II) 10.8mSv. Standard dose descriptors [standard deviation (SD); CT dose index vol (CTDI vol ); dose-length product (DLP body ); size-specific dose estimate (SSDE)] were also compared. Effective dose, organ doses and SSDE for various CT-guided interventional biopsies on different CT-scanner generations following recommendations of the ICRP103 are provided. New CT-scanner generations involve markedly lower radiation doses versus older devices. • Effective dose, organ dose and SSDE are provided for CT-guided interventional examinations. • These data allow identifying organs at risk of higher radiation dose. • Detailed knowledge of radiation dose may contribute to a better individual risk-stratification. • New CT-scanner generations involve markedly lower radiation doses compared to older devices.

  13. Concept Evaluation Using the PDSA Cycle for Continuous Quality Improvement.

    Science.gov (United States)

    Laverentz, Delois Meyer; Kumm, Sharon

    As concept-based nursing education gains popularity, there is little literature on how to sustain quality after initiation of the curriculum. Critical appraisal of concepts in a university program revealed varying definitions, attributes, and exemplars resulting in student confusion. The Plan, Do, Study, Act (PDSA) cycle for continuous quality improvement was used for concept evaluation. The goals of the evaluation project were: 1) to develop common definition and attributes for concepts and 2) to develop horizontal and vertical leveling of exemplars to build on prior student learning. The continuous quality improvement process can be used to prevent "concept creep" and ensure internal consistency of concept definitions, attributes, and exemplars.

  14. Identifying disease-centric subdomains in very large medical ontologies : A case-study on breast cancer concepts in SNOMED CT. Or: Finding 2500 out of 300.000

    NARCIS (Netherlands)

    Milian, Krystyna; Aleksovski, Zharko; Vdovjak, Richard; Ten Teije, Annette; Van Harmelen, Frank

    2010-01-01

    Modern medical vocabularies can contain up to hundreds of thousands of concepts. In any particular use-case only a small fraction of these will be needed. In this paper we first define two notions of a disease-centric subdomain of a large ontology. We then explore two methods for identifying

  15. Translational research: a concept analysis.

    Science.gov (United States)

    Wendler, M Cecilia; Kirkbride, Geri; Wade, Kristen; Ferrell, Lynne

    2013-01-01

    BACKGROUND/CONCEPTUAL FRAMEWORK: Little is known about which approaches facilitate adoption and sustainment of evidence-based practice change in the highly complex care environments that constitute clinical practice today. The purpose of this article was to complete a concept analysis of translational research using a modified Walker and Avant approach. DESIGN/DATA COLLECTION: Using a rigorous and thorough review of the recent health care literature generated by a deep electronic search from 2004-2011, 85 appropriate documents were retrieved. Close reading of the articles by three coresearchers yielded an analysis of the emerging concept of translational research. Using the iterative process described by Walker and Avant, a tentative definition of the concept of translational research, along with antecedents and consequences were identified. Implications for health care professionals in education, practice, and research are offered. Further research is needed to determine the adequacy of the definition, to identify empirical referents, and to guide theory development. The study resulted in a theoretical definition of the concept of translational research, along with identification of antecedents and consequences and a description of an ideal or model case to illustrate the definition. Implications for practice and education include the importance of focusing on translational research approaches that may reduce the research-practice gap in health care, thereby improving patient care delivery. Research is needed to determine the usefulness of the definition in health care clinical practice.

  16. Suicide Lethality: A Concept Analysis.

    Science.gov (United States)

    DeBastiani, Summer; De Santis, Joseph P

    2018-02-01

    Suicide is a significant health problem internationally. Those who complete suicide may have different behaviors and risk factors than those who attempt a non-fatal suicide. The purpose of this article is to analyze the concept of suicide lethality and propose a clear definition of the concept through the identification of antecedents, attributes, and consequences. A literature search for articles published in the English language between 1970 and 2016 was conducted using MEDLINE, the Cochrane Library, Pubmed, Psychlit, Ovid, PsycINFO, and Proquest. The bibliographies of all included studies were also reviewed to identify additional relevant citations. A concept analysis was conducted on the literature findings using six stages of Walker and Avant's method. The concept analysis differentiated between suicide, lethality, suicidal behavior, and suicide lethality. Presence of a suicide plan or a written suicide note was not found to be associated with the majority of completed suicides included in the definition of suicide lethality. There are a few scales that measure the lethality of a suicide attempt, but none that attempt to measure the concept of suicide lethality as described in this analysis. Clarifying the concept of suicide lethality encourages awareness of the possibility of different suicidal behaviors associated with different suicide outcomes and will inform the development of future nursing interventions. A clearer definition of the concept of suicide lethality will guide clinical practice, research, and policy development aimed at suicide prevention.

  17. What is the complementary role of ultrasound evaluation in the diagnosis of acute appendicitis after CT?

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Kyung Mi [Department of Radiology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Lee, Kwanseop [Department of Radiology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of)], E-mail: kwanseop@hallym.or.kr; Kim, Min-Jeong; Yoon, Hoi Soo; Jeon, Eui Yong; Koh, Sung Hye [Department of Radiology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Min, Kwangseon [Department of Pathology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Choi, Dongil [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine (Korea, Republic of)

    2010-04-15

    The objective of our study was to estimate the complementary role of ultrasound evaluation in the diagnosis of acute appendicitis after abdominoplevic CT. A total of 104 patients initially underwent abdominopelvic CT before appendix US due to acute abdominal pain. All CT examinations were evaluated retrospectively for the presence of acute appendicitis. The findings of appendix on CT were classified into five categories (definite appendicitis, probably appendicitis, equivocal CT findings for diagnosis of appendicitis, probably not appendicitis, and normal looking appendix). Appendix US images and their radiologic reports were also evaluated retrospectively. Then, CT and US findings were correlated with clinical or pathologic diagnosis. Three all patients with definite appendicitis initially on CT again showed US findings of appendicitis. In the 32 patients of probably appendicitis on CT, US showed normal looking appendix in seven patients (21.8%, 7 of 32) who improved with medical treatment and discharged. In the 16 patients of equivocal CT findings for diagnosis of appendicitis, US showed appendicitis in seven patients (43.8%, 7 of 16) and normal looking appendix in nine patients. In the 12 patients of probably not appendicitis on CT, US showed acute appendicitis in two patients (16.7%, 2 of 12). In the 41 patients of normal looking appendix on CT, US showed acute appendicitis in five patients (12.2%, 5 of 41). US reevaluation enables us to avoid misdiagnosis of appendicitis on CT and improve diagnostic accuracy of acute appendicitis.

  18. Goal Definition

    DEFF Research Database (Denmark)

    Bjørn, Anders; Laurent, Alexis; Owsianiak, Mikołaj

    2018-01-01

    The goal definition is the first phase of an LCA and determines the purpose of a study in detail. This chapter teaches how to perform the six aspects of a goal definition: (1) Intended applications of the results, (2) Limitations due to methodological choices, (3) Decision context and reasons...... for carrying out the study, (4) Target audience , (5) Comparative studies to be disclosed to the public and (6) Commissioner of the study and other influential actors. The instructions address both the conduct and reporting of a goal definition and are largely based on the ILCD guidance document (EC...

  19. Space Mission Concept Development Using Concept Maturity Levels

    Science.gov (United States)

    Wessen, Randii R.; Borden, Chester; Ziemer, John; Kwok, Johnny

    2013-01-01

    Over the past five years, pre-project formulation experts at the Jet Propulsion Laboratory (JPL) has developed and implemented a method for measuring and communicating the maturity of space mission concepts. Mission concept development teams use this method, and associated tools, prior to concepts entering their Formulation Phases (Phase A/B). The organizing structure is Concept Maturity Level (CML), which is a classification system for characterizing the various levels of a concept's maturity. The key strength of CMLs is the ability to evolve mission concepts guided by an incremental set of assessment needs. The CML definitions have been expanded into a matrix form to identify the breadth and depth of analysis needed for a concept to reach a specific level of maturity. This matrix enables improved assessment and communication by addressing the fundamental dimensions (e.g., science objectives, mission design, technical risk, project organization, cost, export compliance, etc.) associated with mission concept evolution. JPL's collaborative engineering, dedicated concept development, and proposal teams all use these and other CML-appropriate design tools to advance their mission concept designs. This paper focuses on mission concept's early Pre-Phase A represented by CMLs 1- 4. The scope was limited due to the fact that CMLs 5 and 6 are already well defined based on the requirements documented in specific Announcement of Opportunities (AO) and Concept Study Report (CSR) guidelines, respectively, for competitive missions; and by NASA's Procedural Requirements NPR 7120.5E document for Projects in their Formulation Phase.

  20. Technical principles of dual source CT

    International Nuclear Information System (INIS)

    Petersilka, Martin; Bruder, Herbert; Krauss, Bernhard; Stierstorfer, Karl; Flohr, Thomas G.

    2008-01-01

    During the past years, multi-detector row CT (MDCT) has evolved into clinical practice with a rapid increase of the number of detector slices. Today's 64 slice CT systems allow whole-body examinations with sub-millimeter resolution in short scan times. As an alternative to adding even more detector slices, we describe the system concept and design of a CT scanner with two X-ray tubes and two detectors (mounted on a CT gantry with a mechanical offset of 90 deg.) that has the potential to overcome limitations of conventional MDCT systems, such as temporal resolution for cardiac imaging. A dual source CT (DSCT) scanner provides temporal resolution equivalent to a quarter of the gantry rotation time, independent of the patient's heart rate (83 ms at 0.33 s rotation time). In addition to the benefits for cardiac scanning, it allows to go beyond conventional CT imaging by obtaining dual energy information if the two tubes are operated at different voltages. Furthermore, we discuss how both acquisition systems can be used to add the power reserve of two X-ray tubes for long scan ranges and obese patients. Finally, future advances of DSCT are highlighted

  1. Towards a clearer definition and understanding of "Indiginous ...

    African Journals Online (AJOL)

    Towards a clearer definition and understanding of "Indiginous Community" for purposes of the Intellectual Property Laws Amendment Bill, 2010: an exploration of the concepts "Indiginous" and "Traditional"

  2. The meaning and knowledge of definition in elementary school geometry

    OpenAIRE

    Tomažič, Maša

    2017-01-01

    The first part of the diploma thesis considers the theoretical aspects of the meaning of concepts and definition of concepts. The focus is on the question ‘Why are definitions important and how should definitions look like?’. Then, the difference between the definition of a concept and the image of a concept is explained and the interactions between them considered. The second part of this diploma thesis describes the results of a pilot study, which considered the extent to which seventh...

  3. TH-C-BRD-06: A Novel MRI Based CT Artifact Correction Method for Improving Proton Range Calculation in the Presence of Severe CT Artifacts

    International Nuclear Information System (INIS)

    Park, P; Schreibmann, E; Fox, T; Roper, J; Elder, E; Tejani, M; Crocker, I; Curran, W; Dhabaan, A

    2014-01-01

    Purpose: Severe CT artifacts can impair our ability to accurately calculate proton range thereby resulting in a clinically unacceptable treatment plan. In this work, we investigated a novel CT artifact correction method based on a coregistered MRI and investigated its ability to estimate CT HU and proton range in the presence of severe CT artifacts. Methods: The proposed method corrects corrupted CT data using a coregistered MRI to guide the mapping of CT values from a nearby artifact-free region. First patient MRI and CT images were registered using 3D deformable image registration software based on B-spline and mutual information. The CT slice with severe artifacts was selected as well as a nearby slice free of artifacts (e.g. 1cm away from the artifact). The two sets of paired MRI and CT images at different slice locations were further registered by applying 2D deformable image registration. Based on the artifact free paired MRI and CT images, a comprehensive geospatial analysis was performed to predict the correct CT HU of the CT image with severe artifact. For a proof of concept, a known artifact was introduced that changed the ground truth CT HU value up to 30% and up to 5cm error in proton range. The ability of the proposed method to recover the ground truth was quantified using a selected head and neck case. Results: A significant improvement in image quality was observed visually. Our proof of concept study showed that 90% of area that had 30% errors in CT HU was corrected to 3% of its ground truth value. Furthermore, the maximum proton range error up to 5cm was reduced to 4mm error. Conclusion: MRI based CT artifact correction method can improve CT image quality and proton range calculation for patients with severe CT artifacts

  4. Automated quantification of emphysema in CT studies of the lung

    International Nuclear Information System (INIS)

    Archer, D.C.; deKemp, R.A.; Coblentz, C.L.; Nahmias, C.

    1991-01-01

    Emphysema by definition is a pathologic diagnosis. Recently, in vivo quantification of emphysema from CT with point counting and with a GE 9800 CT scanner program called Density Mask has been described. These methods are laborious and time-consuming, making them unsuitable for screening. The propose of this paper is to create a screening test for emphysema. The authors developed a computer program that quantifies the amount of emphysema from standard CT-scans. The computer was programmed to recognize the lung edges on each section by identifying abrupt changes in CT numbers; grow regions within each lung to identify and separate the lungs from other structures; count regions of lung containing CT numbers measuring <-900 HU corresponding to areas of emphysema; and calculation the percentage of emphysema present from the volume of normal emphysematous lung. The programs were written in C and urn on a Sun 4/100 workstation

  5. CT simulation in nodal positive breast cancer

    International Nuclear Information System (INIS)

    Horst, E.; Schuck, A.; Moustakis, C.; Schaefer, U.; Micke, O.; Kronholz, H.L.; Willich, N.

    2001-01-01

    Background: A variety of solutions are used to match tangential fields and opposed lymph node fields in irradiation of nodal positive breast cancer. The choice is depending on the technical equipment which is available and the clinical situation. The CT simulation of a non-monoisocentric technique was evaluated in terms of accuracy and reproducibility. Patients, Material and Methods: The field match parameters were adjusted virtually at CT simulation and were compared with parameters derived mathematically. The coordinate transfer from the CT simulator to the conventional simulator was analyzed in 25 consecutive patients. Results: The angles adjusted virtually for a geometrically exact coplanar field match corresponded with the angles calculated for each set-up. The mean isocenter displacement was 5.7 mm and the total uncertainty of the coordinate transfer was 6.7 mm (1 SD). Limitations in the patient set-up became obvious because of the steep arm abduction necessary to fit the 70 cm CT gantry aperture. Required modifications of the arm position and coordinate transfer errors led to a significant shift of the marked matchline of >1.0 cm in eight of 25 patients (32%). Conclusion: The virtual CT simulation allows a precise and graphic definition of the field match parameters. However, modifications of the virtual set-up basically due to technical limitations were required in a total of 32% of cases, so that a hybrid technique was adapted at present that combines virtual adjustment of the ideal field alignment parameters with conventional simulation. (orig.) [de

  6. Spinal CT scan, 2

    International Nuclear Information System (INIS)

    Nakagawa, Hiroshi

    1982-01-01

    Plain CT described fairly accurately the anatomy and lesions of the lumbar and sacral spines on their transverse sections. Since hernia of the intervertebral disc could be directly diagnosed by CT, indications of myelography could be restricted. Spinal-canal stenosis of the lumbar spine occurs because of various factors, and CT not only demonstrated the accurate size and morphology of bony canals, but also elucidated thickening of the joints and yellow ligament. CT was also useful for the diagnosis of tumors in the lumbar and sacral spines, visualizing the images of bone changes and soft tissues on the trasverse sections. But the diagnosis of intradural tumors required myelography and metrizamide CT. CT has become important for the diagnosis of spinal and spinal-cord diseases and for selection of the route of surgical arrival. (Chiba, N.)

  7. Ecological units: definitions and application.

    Science.gov (United States)

    Jax, Kurt

    2006-09-01

    Concepts of ecological units, such as population, community, and ecosystem, are at the basis of ecological theory and research and have increasingly become the focus of conservation strategies. Concepts of these units still suffer from inconsistencies and confusions over terminology. The different concepts are treated here together as a common "conceptual cluster," with similar ecological functions (roles) and similar problems in their definition and use. An analysis of the multitude of existing terms and concepts that have been developed for these units reveals that they differ with respect to at least four basic criteria: (i) the questions as to whether they are defined statistically or via a network of interactions; (ii) if their boundaries are drawn by topographical or process-related criteria; (iii) how high the required internal relationships are; and (iv) if they are perceived as "real" entities or abstractions by an observer The various definitions cannot be easily sorted into just a few types, but they can be characterized by several independent criteria. I argue that serious problems arise if the different possibilities of defining ecological units are not recognized and if the concepts are perceived as self-evident. The different concepts of ecological units should be defined and used in a philosophically informed manner I propose a dual approach to the use of ecological units. Generic meanings of the main concepts (especially population, community, and ecosystem) should be retained only as heuristically useful perspectives, while specific and "operational" definitions of the concepts as units should be developed, depending on specific purposes of their use. Some thoughts on the basic requirements for such definitions and the domains of their uses are briefly explained.

  8. Vocal cord paralysis due to extralaryngeal causes : evaluation with CT

    International Nuclear Information System (INIS)

    Lee, Jong Hwa; Mo, Jong Hyun; Moon, Sung Hee; Na, Dong Gyu; Byun, Hong Sik; Cho, Jae Min; Han, Boo Kyung; Son, Young Ik; Baek, Chung Whan

    1999-01-01

    To evaluate the use of CT in patients with vocal cord paralysis due to extralaryngeal causes, and to use CT for the assessment of extralaryngeal diseases causing vocal cord paralysis. We prospectively studied the results of CT in 41 patients with vocal cord paralysis in whom laryngoscopy revealed no laryngeal cause and physical examination demonstrated no definite extralaryngeal cause. The extralaryngeal cause of vocal cord palsy was determined after comprehensive clinical diagnosis. Enhanced CT scans were acquired from the skull base and continued to the level of the aorticopulmonary window. We used CT to assess the detection rate for extralaryngeal causes and to extimate the extent of extralaryngeal disease and the distribution of lesions. CT revealed that in 20 of 41 patients(49%) the extralarygeal causes of vocal paralysis were as follows : thyroid cancer(n=10), nodal disease(n=6), esophageal cancer(n=2), neurogenic tumor(n=1), aortic aneurysm(n=1). Lesions were located on the left side in 13 patients(65%), and in the tracheoesophageal groove in 15(75%). In patients with vocal cord paralysis in whom no definite lesion is seen on physical examination , CT could be a useful primary imaging method for the assessment of extralaryngeal causes

  9. CT of Mirizzi syndrome

    International Nuclear Information System (INIS)

    Yamamoto, Shinichiro; Fukushima, Keisuke; Ishihara, Kenji; Hirano, Yutaka; Sano, Kaizo

    1983-01-01

    PTC or ERCP findings of four cases of Mirizzi syndrome were demonstrated. They consisted of a smooth stricture of the common hepatic duct, curved impressions of the duct and dilatation of proximal biliary radicles. CT could visualize the impacted stone in the neck of the gallbladder, dilatation of proximal common hepatic and intrahepatic duct. Absence of the dilatation of distal common bile duct could also be confirmed by CT, thus the diagnosis of Mirizzi syndrome might be possible by CT. (author)

  10. CT imaging of necrosive fasciitis

    International Nuclear Information System (INIS)

    Schulze, M.; Overkamp, D.; Joanoviciu, S.; Horger, M.

    2008-01-01

    NF is a rare but dramatic and often fatal infection of the fascii and adjoining soft tissues. Contrary to the Fournier's definition, it is most common in elderly people. Patients with immune problems have a higher risk (e.g. Diabetes mellitus, alcohol or drug abuse, AIDS, leukaemia, chemotherapy and immunosuppressive medication). Predisposition factors are diverticulitis, insect bites, or surgical interventions (Uppot RN, Levy HM, PLatel PH, Radiology 2003; 226; 115; Wysoki MG, Santora TA, Shah RM et al. Necrotizing fasciitis: CT characteristics, Radiology 1997; 203;859). Men are affected more frequently than women. In principle, NF may occur everywhere in the body but incidence in the region of the scrotum, perineum and lower extremities are the most common. (orig.)

  11. Coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2009-07-01

    Coronary CT angiography has attained increasing scientific attention at academic institutions and has become a highly accurate diagnostic modality. Extending this knowledge into a practice setting is the purpose of 'Coronary CT Angiography'. This book will assist you in integrating cardiac CT into your daily practice, while also giving an overview of the current technical status and applications. The specific features of scanners from all four main vendors are also presented providing an objective overview of noninvasive coronary angiography using CT. (orig.)

  12. Head CT scan

    Science.gov (United States)

    ... scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... head size in children Changes in thinking or behavior Fainting Headache, when you have certain other signs ...

  13. A Bayesian concept learning approach to crowdsourcing

    DEFF Research Database (Denmark)

    Viappiani, P.; Zilles, S.; Hamilton, H.J.

    2011-01-01

    techniques, inference methods, and query selection strategies to assist a user charged with choosing a configuration that satisfies some (partially known) concept. Our model is able to simultaneously learn the concept definition and the types of the experts. We evaluate our model with simulations, showing......We develop a Bayesian approach to concept learning for crowdsourcing applications. A probabilistic belief over possible concept definitions is maintained and updated according to (noisy) observations from experts, whose behaviors are modeled using discrete types. We propose recommendation...

  14. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses ... of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  15. Modelos e concepções de inovação: a transição de paradigmas, a reforma da C&T brasileira e as concepções de gestores de uma instituição pública de pesquisa em saúde Innovation models and conceptions: transition of paradigm, the Brazilian S&T reform and conceptions of managers from a public health research institution

    Directory of Open Access Journals (Sweden)

    Mariza Velloso Fernandez Conde

    2003-01-01

    Full Text Available O artigo analisa as diversas acepções do termo "inovação" presentes na literatura, em documentos institucionais e referidas por gestores de C&T. A partir da revisão da literatura sobre inovação e modelos de análise da inovação analisaram-se as concepções de inovação coletadas junto a gestores da Fiocruz. Constatou-se que a complexidade dos processos de inovação, a dificuldade de identificação dos nexos causais entre Ciência, Tecnologia, Economia e Sociedade e a aceleração das mudanças do papel do conhecimento geraram uma grande proliferação de modelos de análise da inovação em oposição ao "modelo linear de inovação", caracterizando um período de transição paradigmática. A análise dos documentos institucionais e das concepções dos gestores indicou uma convergência com concepções e modelos de inovação adotados pelos países de economia avançada. Esses modelos estariam fundamentando uma reforma do setor de C&T brasileiro que pode ser caracterizada como uma política para a inovação tecnológica. Essa perspectiva reduz os objetivos das atividades de C&T a uma única questão: articular o empreendimento científico com a inovação industrial e a competitividade, o que introduz questões significativas para sua tradução na área da saúde pública.This article intends to identify and to discuss the meanings of the term innovation in specialized literature, in institutional documents and in a public health research institution managers' interpretations. A brief review of specialized literature was undertaken concerning innovation and models of analysis of innovation. This review was used as reference for the analysis of the meanings found in institutional documents of Science, Technology & Innovation from the Brazilian Ministry of the Science and Technology and in innovation conceptions from managers of Fiocruz. The complexity of the processes involved in innovation generation, the difficulty to identify

  16. [Biometric bases: basic concepts of probability calculation].

    Science.gov (United States)

    Dinya, E

    1998-04-26

    The author gives or outline of the basic concepts of probability theory. The bases of the event algebra, definition of the probability, the classical probability model and the random variable are presented.

  17. Conceptualising Business Models: Definitions, Frameworks and Classifications

    OpenAIRE

    Erwin Fielt

    2013-01-01

    The business model concept is gaining traction in different disciplines but is still criticized for being fuzzy and vague and lacking consensus on its definition and compositional elements. In this paper we set out to advance our understanding of the business model concept by addressing three areas of foundational research: business model definitions, business model elements, and business model archetypes. We define a business model as a representation of the value logic of an organization in...

  18. Locoregional recurrence of rectal carcinoma. A CT-analysis and a target volume concept in adjuvant radiotherapy; Das lokoregionaere Rezidiv des Rektumkarzinoms. Eine computertomographische Analyse und ein Zielvolumenkonzept fuer die adjuvante Radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Bagatzounis, A. [Wuerzburg Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie; Koelbl, O. [Wuerzburg Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie; Mueller, G. [Wuerzburg Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie; Oppitz, U. [Wuerzburg Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie; Willner, J. [Wuerzburg Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie; Flentje, M. [Wuerzburg Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie

    1997-02-01

    Patients and method: 155 patients with the diagnosis of rectal carcinoma recurrences were treated in our institution between 1980 and 1995. To determine the extension of the recurrent tumor within the pelvic levels (praesacral levels S1-S5, precoccygeal-, pelvic floor level and perineal level) and the tumor infiltration of pelvic organs and muscles we analysed the pretherapeutic CT-images. The lymphnode recurrences were classified as: Pararectal-, presacral-, iliac internal-, iliac external-, iliac communis- and paraaortal recurrences. Results: Sixty-one percent of the patients with rectum exstirpation and 66% with anterior resection showed a combined local and nodal recurrence. Isolated lymph node recurrences were rare (4% and 5%). The local recurrence was mostly situated in the presacral pelvis, predominantly there was an infiltration of the presacral space at the level of S4, S5 and os coccygis regardless of the operating method and the primary tumor location. The anastomosis was involved in the tumor recurrence in 93% of the anteriorly resected patients. In 9 out of 96 patients after rectum exstirpation the pelvic region caudal of the tip of the coccyx was the origin of the recurrent tumor. Primarily all 9 patients had a deep-seated carcinoma (<6 cm ab ano). Only 2 patients showed an isolated perineal recurrence after rectum exstirpation. Two thirds of the deepseated tumors showed a vaginal involvement. The incidence of iliac internal- and presacral nodal recurrence was 47 to 59%. The incidence of iliac external lymph node recurrences was 7% after rectum exstirpation and 2% after anterior resection/Hartmann procedure. (orig./AJ) [Deutsch] Patienten und Methode: 155 Patienten wurden in unserer Klinik im Zeitraum 1980 bis 1995 wegen eines Rektumkarzinomrezidivs behandelt. Die Rezidivausdehnung innerhalb der Beckenetagen (Sakralsegmente S1 bis S5, praekokzygeal, Beckenbodenetage und perineales Weichgewebe) und die Infiltration von Beckenorganen und Muskelgruppen

  19. Pitch and timbre : definition, meaning and use

    NARCIS (Netherlands)

    Houtsma, A.J.M.

    1997-01-01

    Pitch and timbre are terms frequently used in studies on sound perception. Despite the existence of formal definitions, these terms are often used ambiguously in the literature. This paper is intended as a review of the ANSI definitions and their shortcomings, of modern ways to define the concepts

  20. Complex overlapping concepts: An effective auditing methodology for families of similarly structured BioPortal ontologies.

    Science.gov (United States)

    Zheng, Ling; Chen, Yan; Elhanan, Gai; Perl, Yehoshua; Geller, James; Ochs, Christopher

    2018-05-28

    In previous research, we have demonstrated for a number of ontologies that structurally complex concepts (for different definitions of "complex") in an ontology are more likely to exhibit errors than other concepts. Thus, such complex concepts often become fertile ground for quality assurance (QA) in ontologies. They should be audited first. One example of complex concepts is given by "overlapping concepts" (to be defined below.) Historically, a different auditing methodology had to be developed for every single ontology. For better scalability and efficiency, it is desirable to identify family-wide QA methodologies. Each such methodology would be applicable to a whole family of similar ontologies. In past research, we had divided the 685 ontologies of BioPortal into families of structurally similar ontologies. We showed for four ontologies of the same large family in BioPortal that "overlapping concepts" are indeed statistically significantly more likely to exhibit errors. In order to make an authoritative statement concerning the success of "overlapping concepts" as a methodology for a whole family of similar ontologies (or of large subhierarchies of ontologies), it is necessary to show that "overlapping concepts" have a higher likelihood of errors for six out of six ontologies of the family. In this paper, we are demonstrating for two more ontologies that "overlapping concepts" can successfully predict groups of concepts with a higher error rate than concepts from a control group. The fifth ontology is the Neoplasm subhierarchy of the National Cancer Institute thesaurus (NCIt). The sixth ontology is the Infectious Disease subhierarchy of SNOMED CT. We demonstrate quality assurance results for both of them. Furthermore, in this paper we observe two novel, important, and useful phenomena during quality assurance of "overlapping concepts." First, an erroneous "overlapping concept" can help with discovering other erroneous "non-overlapping concepts" in its vicinity

  1. Retractile mesenteritis in a 12-year-old girl: CT findings

    International Nuclear Information System (INIS)

    Ueda, D.; Chiba, S.

    1997-01-01

    We report a pathologically proven case of retractile mesenteritis in a 12-year-old girl. Computed tomography (CT) demonstrated a large mass of fat density completely circumscribing the colon. Although the definitive diagnosis of retractile mesenteritis depends on histopathological findings, recognition of CT features is helpful in the diagnosis. (orig.). With 1 fig

  2. Evaluation of the efficiency of FDG PET/CT in detection and characterization of skeletal metastases

    Directory of Open Access Journals (Sweden)

    Ahmed Wafaie

    2014-03-01

    Conclusion: Fused PET/CT was highly efficient in evaluation of skeletal metastases with superior performance in: detection of early bone marrow infiltration not apparent on CT, resolution of metabolic activity before definite signs of complete healing on CT, detection of missed sclerotic metastases on PET due to their relatively low metabolic activity, detection of intra and extra osseous recurrence and differentiation of benign from malignant bone lesions.

  3. Hidden Curriculum: An Analytical Definition

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Andarvazh

    2018-03-01

    Full Text Available Background: The concept of hidden curriculum was first used by Philip Jackson in 1968, and Hafferty brought this concept to the medical education. Many of the subjects that medical students learn are attributed to this curriculum. So far several definitions have been presented for the hidden curriculum, which on the one hand made this concept richer, and on the other hand, led to confusion and ambiguity.This paper tries to provide a clear and comprehensive definition of it.Methods: In this study, concept analysis of McKenna method was used. Using keywords and searching in the databases, 561 English and 26 Persian references related to the concept was found, then by limitingthe research scope, 125 abstracts and by finding more relevant references, 55 articles were fully studied.Results: After analyzing the definitions by McKenna method, the hidden curriculum is defined as follows: The hidden curriculum is a hidden, powerful, intrinsic in organizational structure and culture and sometimes contradictory message, conveyed implicitly and tacitly in the learning environment by structural and human factors and its contents includes cultural habits and customs, norms, values, belief systems, attitudes, skills, desires and behavioral and social expectations can have a positive or negative effect, unplanned, neither planners nor teachers, nor learners are aware of it. The ultimate consequence of the hidden curriculum includes reproducing the existing class structure, socialization, and familiarizing learners for transmission and joining the professional world.Conclusion: Based on the concept analysis, we arrived at an analytical definition of the hidden curriculum that could be useful for further studies in this area.Keywords: CONCEPT ANALYSIS, HIDDEN CURRICULUM, MCKENNA’S METHOD

  4. CT of pleural abnormalities

    International Nuclear Information System (INIS)

    Webb, W.R.

    1995-01-01

    Briefly discussed were CT diagnosis of pleural thickening, CT technique for examining the pleura or pleuro-pulmonary disease, diagnosis of pleural collections, diagnosis of pleural fluid abnormalities in patients with pneumonia, pleural neoplasms, malignant (diffuse) mesothelioma, metastases, local fibrous tumor of the pleura (benign mesothelioma) (21 refs.)

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits CT scanning is painless, noninvasive and accurate. A ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams ...

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  8. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  9. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional ... advantage of CT is its ability to image bone, soft tissue and blood vessels all at the same time. ...

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional ... advantage of CT is its ability to image bone, soft tissue and blood vessels all at the same time. ...

  11. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional ... advantage of CT is its ability to image bone, soft tissue and blood vessels all at the same time. ...

  12. CT of pleural abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Webb, W R [California Univ., San Francisco, CA (United States). Dept. of Radiology

    1996-12-31

    Briefly discussed were CT diagnosis of pleural thickening, CT technique for examining the pleura or pleuro-pulmonary disease, diagnosis of pleural collections, diagnosis of pleural fluid abnormalities in patients with pneumonia, pleural neoplasms, malignant (diffuse) mesothelioma, metastases, local fibrous tumor of the pleura (benign mesothelioma) (21 refs.).

  13. Tuberculous peritonitis: CT appearance

    International Nuclear Information System (INIS)

    Hanson, R.D.; Hunter, T.B.

    1985-01-01

    Rare, sporadic cases of tuberculous peritonitis do occur in the United States and other advanced countries. Because there are few descriptions of the CT appearance of the peritoneal forms of tuberculous (TB), this report illustrates a case of tuberculous peritonitis with prominent CT findings and discusses the differentiation of this entity from other, more common diseases

  14. CT urography and hematuria

    DEFF Research Database (Denmark)

    Bretlau, Thomas; Hansen, Rasmus H; Thomsen, Henrik S

    2015-01-01

    BACKGROUND: Computed tomography (CT) urography is now used in the work-up of patients with hematuria. The dose of contrast medium and radiation varies considerably between the different CT protocols. PURPOSE: To study the disease prevalence in a consecutive group of patients with hematuria...

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... can help plan the safest and most effective surgery. CT of the sinuses is now widely available and is performed in a relatively short time, especially when compared to magnetic resonance imaging (MRI). CT scanning is painless, noninvasive and ...

  16. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... about tumors of the nasal cavity and sinuses. plan for surgery by defining anatomy. top of page How should ... for sinusitis. CT of the sinuses can help plan the safest and most effective surgery. CT of the sinuses is now widely available ...

  17. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  18. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... or nurse at the time of the CT examination. If your child has a known contrast material ... be given to your child for the CT examination. top of page What does the CT equipment ...

  19. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... view of the body's interior. Refinements in detector technology allow new CT scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," ...

  20. Faith: a concept analysis.

    Science.gov (United States)

    Dyess, Susan Macleod

    2011-12-01

    This paper reports a concept analysis of faith. There are numerous scholars who consider spirituality and religiosity as they relate to health and nursing. Faith is often implied as linked to these concepts but deserves distinct exploration. In addition, as nursing practice conducted within communities of faith continues to emerge, concept clarification of faith is warranted. Qualitative analysis deliberately considered the concept of faith within the lens of Margaret Newman's health as expanding consciousness. Data sources used included a secondary analysis of stories collected within a study conducted in 2008, two specific reconstructed stories, the identification of attributes noted within these various stories and selected philosophical literature from 1950 to 2009.  A definition was identified from the analysis; faith is an evolving pattern of believing, that grounds and guides authentic living and gives meaning in the present moment of inter-relating. Four key attributes of faith were also identified as focusing on beliefs, foundational meaning for life, living authentically in accordance with beliefs, and interrelating with self, others and/or Divine. Although a seemingly universal concept, faith was defined individually. Faith appeared to be broader than spiritual practices and religious ritual and became the very foundation that enabled human beings to make sense of their world and circumstances. More work is needed to understand how faith community nursing can expand the traditional understanding of denominationally defined faith community practices and how nurses can support faith for individuals with whom they encounter within all nursing practice. © 2011 Blackwell Publishing Ltd.

  1. CT of splenic trauma

    International Nuclear Information System (INIS)

    Griffiths, B.G.; Federle, M.P.; Minagi, H.; Jeffrey, R.B.

    1986-01-01

    Fifty-five consecutive cases of surgically proved splenic injuries were evaluated by CT. CT correctly identified 54 splenic injuries, with one false-negative and three false-positive studies. In the single false-negative study and in two of the three false-positive studies, CT correctly indicated the presence of a large hemoperitoneum and other abdominal visceral lacerations and so correctly indicated the need for surgery. Of the 55 proved cases of splenic injury, CT revealed hemoperitoneum in 54 (99%), perisplenic clot in 47 (85%), splenic laceration in 39 (71%), and subcapsular hematoma in 13 (24%). Perisplenic clot can be distinguished from lysed blood in the peritoneal cavity and is a sensitive and specific sign of splenic trauma, even in the absence of visible splenic laceration. The authors conclude that CT is highly reliable means of evaluating splenic trauma

  2. CT of abdominal abscesses

    International Nuclear Information System (INIS)

    Korobkin, M.T.

    1987-01-01

    The imaging search for a suspected abdominal abscess is common in hospitalized patients, especially after recent abdominal surgery. This paper examines the role of CT in the detection, localization, and treatment of abdominal abscess. The accuracy, limitations, and technical aspects of CT in this clinical setting are discussed. The diagnosis of an abscess is based on the demonstration of a circumscribed abnormal fluid collection. Although percutaneous aspiration with gram stain and culture is usually indicated to differentiate abscess from other fluid collections, the CT-based detection of extraluminal gas bubbles makes the diagnosis of an abscess highly likely. CT is compared with conventional radiographic studies, US, and radio-nuclide imaging. Specific CT and clinical features of abscesses in the following sites are emphasized: subphrenic space, liver, pancreas, kidneys, psoas muscle, appendix, and colonic diverticula. Most abdominal abscesses can be successfully treated with percutaneous drainage techniques. The techniques, results, and limitations of percutaneous abscess drainage are reviewed

  3. CT of tracheal agenesis

    International Nuclear Information System (INIS)

    Strouse, Peter J.; Hernandez, Ramiro J.; Newman, Beverley

    2006-01-01

    Tracheal agenesis is a rare and usually lethal anomaly. In the past, opaque contrast medium was injected via the esophagus to demonstrate the anatomy. To demonstrate the utility of helical and multidetector CT in delineating the aberrant anatomy in newborns with tracheal agenesis. Four newborns with tracheal agenesis were identified from three institutions. Imaging studies and medical records were reviewed. Each child was imaged with chest radiography. One child was imaged on a single-detector helical CT scanner and the other three on multidetector scanners. Helical and multidetector CT with 2D and 3D reconstructions clearly delineated the aberrant tracheobronchial and esophageal anatomy in each infant. Minimum intensity projection reformatted CT images were particularly helpful. One infant each had type I and type II tracheal agenesis. Two infants had type III tracheal agenesis. All four infants died. CT is a useful tool for delineating the aberrant anatomy of newborns with tracheal agenesis and thus helps in making rational clinical decisions. (orig.)

  4. Head trauma and CT

    International Nuclear Information System (INIS)

    Samejima, Kanji; Yoshii, Nobuo; Tobari, Chitoshi

    1979-01-01

    In our cases of acute and subacute subdural hematoma, the use of CT was evaluated. In our department of surgery, acute subdural hematoma was found in 46 of 388 patients of head trauma who underwent CT. Acute subdural hematoma, like epidural hematoma was usually visualized as a high-density area along the cranial inner table, and this was easily differenciated from epidural hematoma because of difference in shape from the other. The picture of acute subdural hematoma was occasionally confused with that of intracerebral hematoma or cerebral contusion. Single use of CT does not differenciate subacute subdural hematoma from chronic subdural hematoma. However, CT usually visualized acute hematoma as a high-density area, showing the extent of hematoma. Comparison of the thickness of hematoma with the axis deviation of the median part such as the 3rd cerebral ventricle suggested severity of cerebral edema. CT also revealed bilateral or multiple lesions of cerebral contusion or intracerebral hematoma. (Ueda, J.)

  5. CT of laryngeal trauma

    International Nuclear Information System (INIS)

    Jeffrey, R.B.

    1986-01-01

    Computed tomography has made a significant contribution to the radiologic assessment of the injured larynx. CT is an accurate, noninvasive modality that can rapidly diagnose both soft tissue and cartilaginous injuries. CT of the larynx involves a minimal degree of patient manipulation and discomfort and can be performed in conjunction with CT evaluation of intracranial or facial injuries. Conventional radiologic studies (anteroposterior and lateral soft tissue films of the neck, tomograms, or xerograms) are capable of demonstrating some cartilaginous fractures but are of limited value in defining the extent of soft tissue injury. In the acute trauma setting, laryngography is often technically difficult to perform because of patient discomfort and inability to cooperate. Although the overall experience is somewhat limited, CT appears to overcome many of the limitations of these conventional radiologic methods. The following is a discussion of the role of CT scanning in evaluating injuries to the larynx and cervical soft tissues

  6. COMET concept

    International Nuclear Information System (INIS)

    Alsmeyer, H.; Tromm, W.

    1995-01-01

    Studies of the COMET core catcher concept developed for a future PWR have been continued. The concept is based on the spreading of a core melt on a sacrificial layer and its erosion, until a subsequent addition of water from below causes a fragmentation of the melt. A porous solidification of the melt would then admit a complete flooding within a short period. (orig.)

  7. Concept Mapping

    Science.gov (United States)

    Technology & Learning, 2005

    2005-01-01

    Concept maps are graphical ways of working with ideas and presenting information. They reveal patterns and relationships and help students to clarify their thinking, and to process, organize and prioritize. Displaying information visually--in concept maps, word webs, or diagrams--stimulates creativity. Being able to think logically teaches…

  8. Management concepts.

    Science.gov (United States)

    Bittner, Rhonda

    2006-01-01

    Management concepts evolve through time. Health care managers can learn new concepts by evaluating classical management strategies, as well as modern-day strategies. Focusing on quality improvement and team building can help managers align the goals of their departments with the goals of the organization, consequently improving patient care.

  9. The ratio of ICRP103 to ICRP60 calculated effective doses from CT: Monte Carlo calculations with the ADELAIDE voxel paediatric model and comparisons with published values

    International Nuclear Information System (INIS)

    Caon, Martin

    2013-01-01

    The ADELAIDE voxel model of paediatric anatomy was used with the EGSnrc Monte Carlo code to compare effective dose from computed tomography (CT) calculated with both the ICRP103 and ICRP60 definitions which are different in their tissue weighting factors and in the included tissues. The new tissue weighting factors resulted in a lower effective dose for pelvis CT (than if calculated using ICRP60 tissue weighting factors), by 6.5 % but higher effective doses for all other examinations. ICRP103 calculated effective dose for CT abdomen + pelvis was higher by 4.6 %, for CT abdomen (by 9.5 %), for CT chest + abdomen + pelvis (by 6 %), for CT chest + abdomen (by 9.6 %), for CT chest (by 10.1 %) and for cardiac CT (by 11.5 %). These values, along with published values of effective dose from CT that were calculated for both sets of tissue weighting factors were used to determine single values for the ratio ICRP103:ICRP60 calculated effective doses from CT, for seven CT examinations. The following values for ICRP103:ICRP60 are suggested for use to convert ICRP60 calculated effective dose to ICRP103 calculated effective dose for the following CT examinations: Pelvis CT, 0.75; for abdomen CT, abdomen + pelvis CT, chest + abdomen + pelvis CT, 1.00; for chest + abdomen CT, and for chest CT. 1.15; for cardiac CT 1.25.

  10. Lateral Concepts

    DEFF Research Database (Denmark)

    Gad, Christopher; Bruun Jensen, casper

    2016-01-01

    This essay discusses the complex relation between the knowledges and practices of the researcher and his/her informants in terms of lateral concepts. The starting point is that it is not the prerogative of the (STS) scholar to conceptualize the world; all our “informants” do it too. This creates...... the possibility of enriching our own conceptual repertoires by letting them be inflected by the concepts of those we study. In a broad sense, the lateral means that there is a many-to-many relation between domains of knowledge and practice. However, each specific case of the lateral is necessarily immanent...... to a particular empirical setting and form of inquiry. In this sense lateral concepts are radically empirical since it locates concepts within the field. To clarify the meaning and stakes of lateral concepts, we first make a contrast between lateral anthropology and Latour’s notion of infra-reflexivity. We end...

  11. Concept theory

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2009-01-01

      Concept theory is an extremely broad, interdisciplinary and complex field of research related to many deep fields with very long historical traditions without much consensus. However, information science and knowledge organization cannot avoid relating to theories of concepts. Knowledge...... organizing systems (e.g. classification systems, thesauri and ontologies) should be understood as systems basically organizing concepts and their semantic relations. The same is the case with information retrieval systems. Different theories of concepts have different implications for how to construe......, evaluate and use such systems. Based on "a post-Kuhnian view" of paradigms this paper put forward arguments that the best understanding and classification of theories of concepts is to view and classify them in accordance with epistemological theories (empiricism, rationalism, historicism and pragmatism...

  12. A case study of analyzing student teachers' concept images of the ...

    African Journals Online (AJOL)

    This paper presents a tool for analyzing student teachers' concept images of the definite integral. The tool shows the basic concepts that underpin the concept of the definite integral and displays them in terms of process and object conceptions within various representations in the context of area under a curve. The use of ...

  13. The definition of alcoholism.

    Science.gov (United States)

    Madden, J S

    1993-11-01

    Formulations of alcohol dependence are continuously refreshed, in line with changing concepts and altered needs. Two new descriptions have been prepared: the revised WHO criteria for substance use disorders and an educative definition of alcoholism. The major sets of diagnostic criteria provided by WHO and by the American Psychiatric Association are moving closer together but have not solved all the semantic problems. More refined assessments are also available to quicken fulfillment of the long-awaited hope that treatments can be matched to patients.

  14. Dual tracer functional imaging of gastroenteropancreatic neuroendocrine tumors using 68Ga-DOTA-NOC PET-CT and 18F-FDG PET-CT: competitive or complimentary?

    Science.gov (United States)

    Naswa, Niraj; Sharma, Punit; Gupta, Santosh Kumar; Karunanithi, Sellam; Reddy, Rama Mohan; Patnecha, Manish; Lata, Sneh; Kumar, Rakesh; Malhotra, Arun; Bal, Chandrasekhar

    2014-01-01

    This study aimed to compare the diagnostic performance of Ga-DOTANOC PET/CT with F-FDG PET/CT in the patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Data of 51 patients with definite histological diagnosis of GEP-NET who underwent both Ga-DOTA-NOC PET-CT and F-FDG PET-CT within a span of 15 days were selected for this retrospective analysis. Sensitivity, specificity, and predictive values were calculated for Ga-DOTA-NOC PET-CT and F-FDG PET-CT, and results were compared both on patientwise and regionwise analysis. Ga-DOTA-NOC PET-CT is superior to F-FDG PET-CT on patientwise analysis (P DOTA-NOC PET-CT is superior to F-FDG PET-CT only for lymph node metastases (P DOTA-NOC PET-CT detected more liver and skeletal lesions compared with F-FDG PET-CT, the difference was not statistically significant. In addition, the results of combined imaging helped in selecting candidates who would undergo the appropriate mode of treatment, whether octreotide therapy or conventional chemotherapy Ga-DOTA-NOC PET-CT seems to be superior to F-FDG PET-CT for imaging GEP-NETs. However, their role seems to be complementary because combination of Ga-DOTA-NOC PET-CT and F-FDG PET-CT in such patients helps demonstrate the total disease burden and segregate them to proper therapeutic groups.

  15. Pediatric obesity: Current concepts.

    Science.gov (United States)

    Greydanus, Donald E; Agana, Marisha; Kamboj, Manmohan K; Shebrain, Saad; Soares, Neelkamal; Eke, Ransome; Patel, Dilip R

    2018-04-01

    This discussion reflects on concepts of obesity in children and adolescents in the early 21st century. It includes reflections on its history, definition, epidemiology, diagnostic perspectives, psychosocial considerations, musculoskeletal complications, endocrine complications and principles of management. In addition to emphasis on diet and exercise, research and clinical applications in the second decade of the 21 st century emphasize the increasing use of pharmacotherapy and bariatric surgery for adolescent and adult populations with critical problems of overweight and obesity. We conclude with a discussion of future directions in pediatric obesity management. Copyright © 2018 Mosby, Inc. All rights reserved.

  16. Computer graphic display of cardiac CT scans

    International Nuclear Information System (INIS)

    Palmer, R.; Carlsson, E.

    1982-01-01

    In order to improve spatial conception and quantitative assessment of the cardiac structures based on cardiac computed tomography, methods for computer graphic display were developed. Excised hearts and living dogs with myocardial infarctions were subjected to CT scanning. The data on the scanner tapes were processed to provide isodensity plots, linear section plots, time-weighted integrated isodensity plots as well as topographical density displays and three-dimensional spatial reconstructions of single and multi-layer scans. (orig.)

  17. First installation of a dual-room IVR-CT system in the emergency room.

    Science.gov (United States)

    Wada, Daiki; Nakamori, Yasushi; Kanayama, Shuji; Maruyama, Shuhei; Kawada, Masahiro; Iwamura, Hiromu; Hayakawa, Koichi; Saito, Fukuki; Kuwagata, Yasuyuki

    2018-03-05

    Computed tomography (CT) embedded in the emergency room has gained importance in the early diagnostic phase of trauma care. In 2011, we implemented a new trauma workflow concept with a sliding CT scanner system with interventional radiology features (IVR-CT) that allows CT examination and emergency therapeutic intervention without relocating the patient, which we call the Hybrid emergency room (Hybrid ER). In the Hybrid ER, all life-saving procedures, CT examination, damage control surgery, and transcatheter arterial embolisation can be performed on the same table. Although the trauma workflow realized in the Hybrid ER may improve mortality in severe trauma, the Hybrid ER can potentially affect the efficacy of other in/outpatient diagnostic workflow because one room is occupied by one severely injured patient undergoing both emergency trauma care and CT scanning for long periods. In July 2017, we implemented a new trauma workflow concept with a dual-room sliding CT scanner system with interventional radiology features (dual-room IVR-CT) to increase patient throughput. When we perform emergency surgery or interventional radiology for a severely injured or ill patient in the Hybrid ER, the sliding CT scanner moves to the adjacent CT suite, and we can perform CT scanning of another in/outpatient. We believe that dual-room IVR-CT can contribute to the improvement of both the survival of severely injured or ill patients and patient throughput.

  18. CT of the heart

    International Nuclear Information System (INIS)

    Lipton, M.J.

    1986-01-01

    Advances based upon the detector elements instead of X-ray film have greatly increased the power of X-ray imaging. Computed tomography (CT) creates cross sectional rather than projected images. Recently, high speed CT devices have been developed for cardiovascular studies. The Cine-CT scanner employs a scanning electron beam deflected on an extended tungsten target ring. Fast scans of 50 millisecond exposures at multiple levels can provide information concerning blood flow in vessels and tissues, myocardial wall motion, valve integrity, coronary bypass graft patency and proximal coronary artery anatomy. Cine-CT dynamic scanning can also provide volume imaging with small quantities (0.05 - 1.5 ml/kg) of contrast medium administered via peripheral vein injections. Cine-CT provides simultaneous measurements of cardiac dimensions and function and is rapidly becoming a new tool for quantitating myocardial blood flow, cardiac chamber volumes and wall mechanics. The future outlook is very promising for this three-dimensional cine-CT technique with high spatial resolution. High speed CT should provide unique diagnostic information and as the technology continues to improve at a rapid speed, this new imaging modality could be a challenge for angiography. (Auth.)

  19. Health Habit: A Concept Analysis.

    Science.gov (United States)

    Opalinski, Andra S; Weglicki, Linda S; Gropper, Sareen S

    2018-01-01

    The aim of this article is to provide clarity of the concept of health habit. Using Walker and Avant's (1983; 2010) method for conducting a concept analysis, the authors identify the attributes and characteristics of health habit, its theoretical and practical application to nursing, and sample cases to further illustrate the concept. Empirical and conceptual literature was used to inform this concept analysis. Articles and one book from 1977 to 2014 were reviewed from PsycINFO, Medline, Cumulative Index to Nursing Health Literature (CINAHL), Science Direct, EBSCOhost and Web of Science. Offering a clear definition and conceptual model of health habit provide the foundation to identify/develop appropriate measures of the concept and guide further investigation of understanding the development and sustainability of healthy habits. Additional research is needed to test the conceptual relationships between health habits and outcome variables as they apply to different groups across the age continuum. © 2017 Wiley Periodicals, Inc.

  20. Definitions Are Important: The Case of Linear Algebra

    Science.gov (United States)

    Berman, Abraham; Shvartsman, Ludmila

    2016-01-01

    In this paper we describe an experiment in a linear algebra course. The aim of the experiment was to promote the students' understanding of the studied concepts focusing on their definitions. It seems to be a given that students should understand concepts' definitions before working substantially with them. Unfortunately, in many cases they do…

  1. Transboundary natural area protection: Broadening the definition of national security

    Science.gov (United States)

    Haven B. Cook

    2007-01-01

    This paper looks at the definition and concept of national security, and examines how the environment is linked with national security. The traditional, state view of national security that guides most foreign policy includes the concepts of military power, sovereignty and geopolitical stability. This paper advocates broadening the definition of security to include...

  2. PET/CT-guided interventional procedures: rationale, justification, initial study, and research plan

    Energy Technology Data Exchange (ETDEWEB)

    Wong, K.; Rahill, J.; Cleary, K. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Petrillo, S.; Earl-Graef, D. [Dept. of Radiology, Georgetown Univ. Hospital, MedStar Health, Washington, DC (United States); Banovac, F.; Levy, E. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Dept. of Radiology, Georgetown Univ. Hospital, MedStar Health, Washington, DC (United States); Shekhar, R. [Dept. of Radiology, Univ. of Maryland Medical Center, Baltimore, MD (United States)

    2007-06-15

    Positron-emission tomography (PET) and PET/CT (computed tomography) are becoming increasingly important for diagnosis and treatment of cancer. Clinically relevant changes can sometimes be seen on PET that are not seen on other imaging modalities. However, PET is not suitable for guiding biopsy as the images are not obtained in real-time. Therefore, our research group has begun developing a concept for PET/CT-guided interventional procedures. This paper presents the rationale for this concept, outlines our research plan, and includes an initial study to evaluate the relative sensitivity of CT and PET/CT in detecting suspicious lesions. (orig.)

  3. Development of a guideline on reading CT images of malignant pleural mesothelioma and selection of the reference CT films

    International Nuclear Information System (INIS)

    Zhou, Huashi; Tamura, Taro; Kusaka, Yukinori; Suganuma, Narufumi; Subhannachart, Ponglada; Vijitsanguan, Chomphunut; Noisiri, Weeraya; Hering, Kurt G.; Akira, Masanori; Itoh, Harumi

    2012-01-01

    Purpose: International experts developed a guideline on reading CT images of malignant pleural mesothelioma for radiologists and physicians. It is intended that it act as a supplement to the current International Classification of HRCT for Occupational and Environmental Respiratory Diseases. Methods: The research literatures on mesothelioma CT features were systematically reviewed. Ten mesothelioma CT features were adopted into the guideline prepared according to experts’ opinion. The terminology of mesothelioma CT features and mesothelioma probability were agreed by consensus of experts. The CT reference films for each mesothelioma feature were selected based on agreement by experts from 22 definite mesothelioma cases confirmed pathologically and immunohistochemically. To support the validity of the mesothelioma probability, 4 experts’ readings of CT films from 57 cases with or without mesothelioma were analyzed by kappa statistics between the experts; sensitivity and specificity for mesothelioma were also assessed. Results: The mesothelioma CT Guideline was developed, providing the terminology of CT features and the mesothelioma probability, the judgement of severity, the distribution of mesothelioma, and the revised CT reading sheet including mesothelioma items. The CT reference films with ten mesothelioma typical features were selected. The average linearly and quadratically weighted kappa of the agreement on the 4-point scale mesothelioma probability were 0.58 and 0.71, respectively. The average sensitivity and specificity for mesothelioma were 93.2% and 65.6%, respectively. Conclusion: The evidence-based mesothelioma CT Guideline developed may serve as a good educational tool to facilitate physicians in recognising mesothelioma and improve their proficiency in diagnosis of mesothelioma.

  4. Development of a guideline on reading CT images of malignant pleural mesothelioma and selection of the reference CT films

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Huashi, E-mail: zhouhua@u-fukui.ac.jp [Department of Environmental Health, School of Medicine, University of Fukui, 23-3 Shimoaitsuki, Matsuoka, Eihezi-cho, Fukui Prefecture 910-1193 (Japan); Tamura, Taro, E-mail: tarou@u-fukui.ac.jp [Department of Environmental Health, School of Medicine, University of Fukui, 23-3 Shimoaitsuki, Matsuoka, Eihezi-cho, Fukui Prefecture 910-1193 (Japan); Kusaka, Yukinori, E-mail: kusakayk@gmail.com [Department of Environmental Health, School of Medicine, University of Fukui, 23-3 Shimoaitsuki, Matsuoka, Eihezi-cho, Fukui Prefecture 910-1193 (Japan); Suganuma, Narufumi, E-mail: nsuganuma@kochi-u.ac.jp [Department of Environmental Medicine, Kochi University School of Medicine (Japan); Subhannachart, Ponglada, E-mail: pongladas@gmail.com [Central Chest Disease Institute of Thailand, 39 Moo 9, Tiwanon Road, Muang Nonthaburi 11000 (Thailand); Vijitsanguan, Chomphunut, E-mail: Chompoo_vj@yahoo.com [Central Chest Disease Institute of Thailand, 39 Moo 9, Tiwanon Road, Muang Nonthaburi 11000 (Thailand); Noisiri, Weeraya, E-mail: weeraya_tat@yahoo.com [Central Chest Disease Institute of Thailand, 39 Moo 9, Tiwanon Road, Muang Nonthaburi 11000 (Thailand); Hering, Kurt G., E-mail: k.g.hering@t-online.de [Department of Diagnostic Radiology, Radiooncology and Nuclear Medicine, Radiological Clinic, Miner' s Hospital, Radiologische Klinik, Lansppaschaftskranhaus Dortmund, Wieckesweg 27 44309, Dortmund (Germany); Akira, Masanori, E-mail: akira@kch.hosp.go.jp [Department of Radiology, National Hospital Organization Kinki-Chuo Chest Medical Center, 1180 Nagasone-cho, Kita-ku, Sakai, Osaka 591-8555 (Japan); Itoh, Harumi, E-mail: hitoh@fmsrsa.fukui-med.ac.jp [Department of Environmental Health, School of Medicine, University of Fukui, 23-3 Shimoaitsuki, Matsuoka, Eihezi-cho, Fukui Prefecture 910-1193 (Japan); Department of Radiology, School of Medicine, University of Fukui, 23-3 Shimoaitsuki Matsuoka, Eiheizi-cho, Fukui Prefecture 910-1193 (Japan); and others

    2012-12-15

    Purpose: International experts developed a guideline on reading CT images of malignant pleural mesothelioma for radiologists and physicians. It is intended that it act as a supplement to the current International Classification of HRCT for Occupational and Environmental Respiratory Diseases. Methods: The research literatures on mesothelioma CT features were systematically reviewed. Ten mesothelioma CT features were adopted into the guideline prepared according to experts’ opinion. The terminology of mesothelioma CT features and mesothelioma probability were agreed by consensus of experts. The CT reference films for each mesothelioma feature were selected based on agreement by experts from 22 definite mesothelioma cases confirmed pathologically and immunohistochemically. To support the validity of the mesothelioma probability, 4 experts’ readings of CT films from 57 cases with or without mesothelioma were analyzed by kappa statistics between the experts; sensitivity and specificity for mesothelioma were also assessed. Results: The mesothelioma CT Guideline was developed, providing the terminology of CT features and the mesothelioma probability, the judgement of severity, the distribution of mesothelioma, and the revised CT reading sheet including mesothelioma items. The CT reference films with ten mesothelioma typical features were selected. The average linearly and quadratically weighted kappa of the agreement on the 4-point scale mesothelioma probability were 0.58 and 0.71, respectively. The average sensitivity and specificity for mesothelioma were 93.2% and 65.6%, respectively. Conclusion: The evidence-based mesothelioma CT Guideline developed may serve as a good educational tool to facilitate physicians in recognising mesothelioma and improve their proficiency in diagnosis of mesothelioma.

  5. CT pelvimetry. La scanopelvimetrie

    Energy Technology Data Exchange (ETDEWEB)

    Vicens, J.L.; Charles, G.; Le Berre, J.; Flageat, J. (Hopital d' Instruction des Armees Begin, 94 - Saint-Mande (FR))

    1989-01-01

    Pelvimetry aims at providing the obstetrician with information on the size and morphology of the female pelvis, thus enabling him to assess the obstetrical prognosis as accurately as possible. Computed tomography (CT) has several advantages, in particular the lower mother and fetus radiation dose. After a brief description of obstetrical anatomy, the usual CT exploration method is presented and its results are considered in terms of measurements, indices and morphological findings. If performed with a very strict exploration procedure, CT pelvimetry is a very reliable, fact and comfortable method of examination. All these advantages, combined with the minimized patient dose, should lead to an increasingly widespread use of this technique.

  6. CT of chest trauma

    International Nuclear Information System (INIS)

    Goodman, P.C.

    1986-01-01

    There appears to be a limited role for computed tomography in the evaluation of chest trauma. The literature contains few papers specifically addressing the use of CT in the setting of chest trauma. Another series of articles relates anecdotal experiences in this regard. This paucity of reports attests to the remarkable amount of information present on conventional chest radiographs as well as the lack of clear indications for CT in the setting of chest trauma. In this chapter traumatic lesions of various areas of the thorax are discussed. The conventional radiographic findings are briefly described and the potential or proven application of CT is addressed

  7. NMR-CT scanner

    International Nuclear Information System (INIS)

    Kose, Katsumi; Sato, Kozo; Sugimoto, Hiroshi; Sato, Masataka.

    1983-01-01

    A brief explanation is made on the imaging methods for a practical diagnostic NMR-CT scanner : A whole-body NMR-CT scanner utilizing a resistive magnet has been developed by Toshiba in cooperation with the Institute for Solid State Physics, the University of Tokyo. Typical NMR-CT images of volunteers and patients obtained in the clinical experiments using this device are presented. Detailed specifications are also shown about the practical NMR-CTs which are to be put on the market after obtaining the government approval. (author)

  8. Dual energy cardiac CT.

    Science.gov (United States)

    Carrascosa, Patricia; Deviggiano, Alejandro; Rodriguez-Granillo, Gastón

    2017-06-01

    Conventional single energy CT suffers from technical limitations related to the polychromatic nature of X-rays. Dual energy cardiac CT (DECT) shows promise to attenuate and even overcome some of these limitations, and might broaden the scope of patients eligible for cardiac CT towards the inclusion of higher risk patients. This might be achieved as a result of both safety (contrast reduction) and physiopathological (myocardial perfusion and characterization) issues. In this article, we will review the main clinical cardiac applications of DECT, that can be summarized in two core aspects: coronary artery evaluation, and myocardial evaluation.

  9. Optimal gross tumor volume definition in lung-sparing intensity modulated radiotherapy for pleural mesothelioma: an in silico study.

    Science.gov (United States)

    Botticella, Angela; Defraene, Gilles; Nackaerts, Kristiaan; Deroose, Christophe M; Coolen, Johan; Nafteux, Philippe; Peeters, Stephanie; Ricardi, Umberto; De Ruysscher, Dirk

    2016-12-01

    The gross tumor volume (GTV) definition for malignant pleural mesothelioma (MPM) is ill-defined. We therefore investigated which imaging modality is optimal: computed tomography (CT) with intravenous contrast (IVC), positron emission tomography-CT (PET/CT) or magnetic resonance imaging (MRI). Sixteen consecutive patients with untreated stage I-IV MPM were included. Patients with prior pleurodesis were excluded. CT with IVC, 18FDG-PET/CT and MRI (T2 and contrast-enhanced T1) were obtained. CT was rigidly co-registered with PET/CT and with MRI. Three sets of pleural GTVs were defined: GTV CT , GTV CT+PET/CT and GTV CT+MRI . Quantitative and qualitative evaluations of the contoured GTVs were performed. Compared to CT-based GTV definition, PET/CT identified additional tumor sites (defined as either separate nodules or greater extent of a known tumor) in 12/16 patients. Compared to either CT or PET/CT, MRI identified additional tumor sites in 15/16 patients (p = .7). The mean GTV CT , GTV CT+PET/CT and GTV CT+MRI [±standard deviation (SD)] were 630.1 cm 3 (±302.81), 640.23 cm 3 (±302.83) and 660.8 cm 3 (±290.8), respectively. Differences in mean volumes were not significant. The mean Jaccard Index was significantly lower in MRI-based contours versus all the others. As MRI identified additional pleural disease sites in the majority of patients, it may play a role in optimal target volume definition.

  10. Travelling Concepts

    DEFF Research Database (Denmark)

    Simonsen, Karen-Margrethe

    2013-01-01

    Review of "Travelling Concepts, Metaphors, and Narratives: Literary and Cultural Studies in an Age of Interdisciplinary Research" ed. by Sibylle Baumgarten, Beatrice Michaelis and Ansagar Nünning, Trier; Wissenschaftlicher Verlag Trier, 2012......Review of "Travelling Concepts, Metaphors, and Narratives: Literary and Cultural Studies in an Age of Interdisciplinary Research" ed. by Sibylle Baumgarten, Beatrice Michaelis and Ansagar Nünning, Trier; Wissenschaftlicher Verlag Trier, 2012...

  11. Concepts of happiness across time and cultures.

    Science.gov (United States)

    Oishi, Shigehiro; Graham, Jesse; Kesebir, Selin; Galinha, Iolanda Costa

    2013-05-01

    We explored cultural and historical variations in concepts of happiness. First, we analyzed the definitions of happiness in dictionaries from 30 nations to understand cultural similarities and differences in happiness concepts. Second, we analyzed the definition of happiness in Webster's dictionaries from 1850 to the present day to understand historical changes in American English. Third, we coded the State of the Union addresses given by U.S. presidents from 1790 to 2010. Finally, we investigated the appearance of the phrases happy nation versus happy person in Google's Ngram Viewer from 1800 to 2008. Across cultures and time, happiness was most frequently defined as good luck and favorable external conditions. However, in American English, this definition was replaced by definitions focused on favorable internal feeling states. Our findings highlight the value of a historical perspective in the study of psychological concepts.

  12. Semantic similarity-based alignment between clinical archetypes and SNOMED CT: an application to observations.

    Science.gov (United States)

    Meizoso García, María; Iglesias Allones, José Luis; Martínez Hernández, Diego; Taboada Iglesias, María Jesús

    2012-08-01

    One of the main challenges of eHealth is semantic interoperability of health systems. But, this will only be possible if the capture, representation and access of patient data is standardized. Clinical data models, such as OpenEHR Archetypes, define data structures that are agreed by experts to ensure the accuracy of health information. In addition, they provide an option to normalize clinical data by means of binding terms used in the model definition to standard medical vocabularies. Nevertheless, the effort needed to establish the association between archetype terms and standard terminology concepts is considerable. Therefore, the purpose of this study is to provide an automated approach to bind OpenEHR archetypes terms to the external terminology SNOMED CT, with the capability to do it at a semantic level. This research uses lexical techniques and external terminological tools in combination with context-based techniques, which use information about structural and semantic proximity to identify similarities between terms and so, to find alignments between them. The proposed approach exploits both the structural context of archetypes and the terminology context, in which concepts are logically defined through the relationships (hierarchical and definitional) to other concepts. A set of 25 OBSERVATION archetypes with 477 bound terms was used to test the method. Of these, 342 terms (74.6%) were linked with 96.1% precision, 71.7% recall and 1.23 SNOMED CT concepts on average for each mapping. It has been detected that about one third of the archetype clinical information is grouped logically. Context-based techniques take advantage of this to increase the recall and to validate a 30.4% of the bindings produced by lexical techniques. This research shows that it is possible to automatically map archetype terms to a standard terminology with a high precision and recall, with the help of appropriate contextual and semantic information of both models. Moreover, the

  13. [Self esteem : concept analysis.

    Science.gov (United States)

    Doré, Christina

    2017-06-01

    Self-esteem is an inner attitude at the base of the construction of personality and psychic balance in addition to be responsible of adaptive processes over the course of life. The concept of self-esteem is commonly used in several disciplines however, it seems that the consensus on its conceptualization and its operationalization is not yet reached. In this context, the concept analysis allows to address a phenomenon and to understand its use and its evolution from a unique disciplinary perspective. The aim of this article is therefore to analyze the concept of self esteem from a nursing perspective to identify : definitions of the term and related terms, attributes, model and limit cases proposed here within the community of mental health nurses, antecedents and consequents as well as the empirical references using the Walker and Avant method. The attributes identified allowing a deeper understanding of the concept are : the self-value, the self-acceptance, the self-efficacy, attitude towards oneself and finally, self-respect.

  14. Conventional 3D staging PET/CT in CT simulation for lung cancer: impact of rigid and deformable target volume alignments for radiotherapy treatment planning.

    Science.gov (United States)

    Hanna, G G; Van Sörnsen De Koste, J R; Carson, K J; O'Sullivan, J M; Hounsell, A R; Senan, S

    2011-10-01

    Positron emission tomography (PET)/CT scans can improve target definition in radiotherapy for non-small cell lung cancer (NSCLC). As staging PET/CT scans are increasingly available, we evaluated different methods for co-registration of staging PET/CT data to radiotherapy simulation (RTP) scans. 10 patients underwent staging PET/CT followed by RTP PET/CT. On both scans, gross tumour volumes (GTVs) were delineated using CT (GTV(CT)) and PET display settings. Four PET-based contours (manual delineation, two threshold methods and a source-to-background ratio method) were delineated. The CT component of the staging scan was co-registered using both rigid and deformable techniques to the CT component of RTP PET/CT. Subsequently rigid registration and deformation warps were used to transfer PET and CT contours from the staging scan to the RTP scan. Dice's similarity coefficient (DSC) was used to assess the registration accuracy of staging-based GTVs following both registration methods with the GTVs delineated on the RTP PET/CT scan. When the GTV(CT) delineated on the staging scan after both rigid registration and deformation was compared with the GTV(CT)on the RTP scan, a significant improvement in overlap (registration) using deformation was observed (mean DSC 0.66 for rigid registration and 0.82 for deformable registration, p = 0.008). A similar comparison for PET contours revealed no significant improvement in overlap with the use of deformable registration. No consistent improvements in similarity measures were observed when deformable registration was used for transferring PET-based contours from a staging PET/CT. This suggests that currently the use of rigid registration remains the most appropriate method for RTP in NSCLC.

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... of any kind, unlike MRI. CT imaging provides real-time imaging, making it a good tool for guiding ... information is needed to determine the extent of soft tissue of the tumor, magnetic resonance imaging (MRI) ...

  16. Abdominal and Pelvic CT

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    Full Text Available ... often used to determine the cause of unexplained pain. CT scanning is fast, painless, noninvasive and accurate. ... help diagnose the cause of abdominal or pelvic pain and diseases of the internal organs, small bowel ...

  17. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to ... time staying still, are claustrophobic, or have chronic pain, you may find a CT exam to be ...

  18. Computed Tomography (CT) -- Head

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    Full Text Available ... is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to ... time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be ...

  19. Abdominal and Pelvic CT

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    Full Text Available ... wear during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images ... and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media ...

  20. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... wear during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images ... and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media ...

  1. Computed Tomography (CT) -- Head

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    Full Text Available ... wear during the procedure. Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images ... and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media ...

  2. Computed Tomography (CT) -- Head

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    Full Text Available ... that lasts for at most a minute or two. You may experience a sensation like you have ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  3. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... that lasts for at most a minute or two. You may experience a sensation like you have ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  4. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... hard time staying still, are claustrophobic, or have chronic pain, you may find a CT exam to ...

  5. Computed Tomography (CT) -- Head

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to ...

  6. Abdominal and Pelvic CT

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    Full Text Available ... have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may ... still, are very nervous or anxious or have chronic pain, you may find a CT exam to ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. CT ... iodine is extremely rare, and radiology departments are well-equipped to deal with them. Because children are ...

  8. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... detailed images of many types of tissue as well as the lungs, bones, and blood vessels. CT ... iodine is extremely rare, and radiology departments are well-equipped to deal with them. Because children are ...

  9. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... CT of the sinuses is primarily used to: help diagnose sinusitis . evaluate sinuses that are filled with ... elevated. Straps and pillows may be used to help the patient maintain the correct position and to ...

  10. Abdominal and Pelvic CT

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    Full Text Available ... emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives. Tell your ... emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives. CT has ...

  11. CT diagnosis of hepatoma

    Energy Technology Data Exchange (ETDEWEB)

    Itai, Yuji [Tokyo Univ. (Japan). Faculty of Medicine

    1982-04-01

    In hepatocellular carcinoma, present status of CT diagnosis was discussed. Hepatocellular carcinoma is sometimes imaged in same concentration as that of surrounding tissues, and the detection rate ranged from 79 to 94%. The rate of differential diagnosis between primary and metastatic carcinoma was only 83% (includes 22% of false diagnosis) using contrast enhancement. The rates of detection of hepatocellular carcinoma and metastatic one were also only 87% and 75%, respectively, even by the combined use of arterial infusion CT and dynamic CT. However, the CT images is reproducible, and is supplemented by the information of US. Thus, the combination of these methods is useful in diagnosing the presence, extension, and nature of liver carcinoma.

  12. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... of the nasal cavity and sinuses. plan for surgery by defining anatomy. top of page How should ... can help plan the safest and most effective surgery. CT of the sinuses is now widely available ...

  13. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... treatments. plan for and assess the results of surgery, such as organ transplants. stage, plan and properly ... CT scanning may eliminate the need for exploratory surgery and surgical biopsy. No radiation remains in a ...

  14. Computed Tomography (CT) -- Head

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  16. Abdominal and Pelvic CT

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    Full Text Available ... its ability to image bone, soft tissue and blood vessels all at the same time. Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  17. Abdominal and Pelvic CT

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    Full Text Available ... as: infections such as appendicitis , pyelonephritis or infected fluid collections, also known as abscesses. inflammatory bowel disease ... caused by a burst appendix or an infected fluid collection and the subsequent spread of infection. CT ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  19. Pediatric CT Scans

    Science.gov (United States)

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  1. Abdominal and Pelvic CT

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    Full Text Available ... tomography (CT) scan View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  2. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... is painless, noninvasive and accurate. It’s also the most reliable imaging technique for determining if the sinuses ... CT scan of the sinuses, the patient is most commonly positioned lying flat on the back. The ...

  3. Abdominal and Pelvic CT

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    Full Text Available ... Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal Cancer top of page This page was reviewed ... GI Tract X-ray (Radiography) - Upper GI Tract Colorectal Cancer Images related to Computed Tomography (CT) - Abdomen ...

  4. Heart CT scan

    Science.gov (United States)

    ... make to decrease the risk of heart disease. Risks Risks of CT scans include: Being exposed to ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  5. Abdominal and Pelvic CT

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    Full Text Available ... the examination table will move during the scan, so that the x-ray beam follows a spiral ... and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections ...

  6. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... the examination table will move during the scan, so that the x-ray beam follows a spiral ... and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... the examination table will move during the scan, so that the x-ray beam follows a spiral ... and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections ...

  8. Abdominal and Pelvic CT

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    Full Text Available ... Radiation Therapy for Bladder Cancer Radiation Therapy for Colorectal Cancer top of page This page was reviewed on ... GI Tract X-ray (Radiography) - Upper GI Tract Colorectal Cancer Images related to Computed Tomography (CT) - Abdomen and ...

  9. Abdominal and Pelvic CT

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    Full Text Available ... should always inform their physician and the CT technologist if there is any possibility that they may ... located in a separate control room, where the technologist operates the scanner and monitors your examination in ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  11. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  12. Abdominal and Pelvic CT

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    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  13. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... Magnetic Resonance Imaging (MRI) - Head Head and Neck Cancer Treatment Radiation Dose in X-Ray and CT Exams Contrast Materials Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation ...

  14. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... x-ray equipment to evaluate the paranasal sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the nasal cavity. CT scanning is painless, noninvasive and accurate. It’s ...

  15. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  16. Abdominal and Pelvic CT

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  17. Computed Tomography (CT) -- Head

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... of the Sinuses? CT is usually the first test ordered when a sinus tumor is suspected. If ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... membranes covering the brain. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Brain ...

  20. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... view of the body's interior. Refinements in detector technology allow nearly all CT scanners to obtain multiple ... for the moving table. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Head ...