Iterative image reconstruction techniques: cardiothoracic computed tomography applications.

Iterative image reconstruction algorithms provide significant improvements over traditional filtered back projection in computed tomography (CT). Clinically available through recent advances in modern CT technology, iterative reconstruction enhances image quality through cyclical image calculation, suppressing image noise and artifacts, particularly blooming artifacts. The advantages of iterative reconstruction are apparent in traditionally challenging cases-for example, in obese patients, those with significant artery calcification, or those with coronary artery stents. In addition, as clinical use of CT has grown, so have concerns over ionizing radiation associated with CT examinations. Through noise reduction, iterative reconstruction has been shown to permit radiation dose reduction while preserving diagnostic image quality. This approach is becoming increasingly attractive as the routine use of CT for pediatric and repeated follow-up evaluation grows ever more common. Cardiovascular CT in particular, with its focus on detailed structural and functional analyses, stands to benefit greatly from the promising iterative solutions that are readily available.

A 2D/3D image analysis system to track fluorescently labeled structures in rod-shaped cells: application to measure spindle pole asymmetry during mitosis.

BACKGROUND: The yeast Schizosaccharomyces pombe is frequently used as a model for studying the cell cycle. The cells are rod-shaped and divide by medial fission. The process of cell division, or cytokinesis, is controlled by a network of signaling proteins called the Septation Initiation Network (SIN); SIN proteins associate with the SPBs during nuclear division (mitosis). Some SIN proteins associate with both SPBs early in mitosis, and then display strongly asymmetric signal intensity at the SPBs in late mitosis, just before cytokinesis. This asymmetry is thought to be important for correct regulation of SIN signaling, and coordination of cytokinesis and mitosis. In order to study the dynamics of organelles or large protein complexes such as the spindle pole body (SPB), which have been labeled with a fluorescent protein tag in living cells, a number of the image analysis problems must be solved; the cell outline must be detected automatically, and the position and signal intensity associated with the structures of interest within the cell must be determined. RESULTS: We present a new 2D and 3D image analysis system that permits versatile and robust analysis of motile, fluorescently labeled structures in rod-shaped cells. We have designed an image analysis system that we have implemented as a user-friendly software package allowing the fast and robust image-analysis of large numbers of rod-shaped cells. We have developed new robust algorithms, which we combined with existing methodologies to facilitate fast and accurate analysis. Our software permits the detection and segmentation of rod-shaped cells in either static or dynamic (i.e. time lapse) multi-channel images. It enables tracking of two structures (for example SPBs) in two different image channels. For 2D or 3D static images, the locations of the structures are identified, and then intensity values are extracted together with several quantitative parameters, such as length, width, cell orientation, background fluorescence and the distance between the structures of interest. Furthermore, two kinds of kymographs of the tracked structures can be established, one representing the migration with respect to their relative position, the other representing their individual trajectories inside the cell. This software package, called "RodCellJ", allowed us to analyze a large number of S. pombe cells to understand the rules that govern SIN protein asymmetry. CONCLUSIONS: "RodCell" is freely available to the community as a package of several ImageJ plugins to simultaneously analyze the behavior of a large number of rod-shaped cells in an extensive manner. The integration of different image-processing techniques in a single package, as well as the development of novel algorithms does not only allow to speed up the analysis with respect to the usage of existing tools, but also accounts for higher accuracy. Its utility was demonstrated on both 2D and 3D static and dynamic images to study the septation initiation network of the yeast Schizosaccharomyces pombe. More generally, it can be used in any kind of biological context where fluorescent-protein labeled structures need to be analyzed in rod-shaped cells. AVAILABILITY: RodCellJ is freely available under http://bigwww.epfl.ch/algorithms.html, (after acceptance of the publication).

Main results of the Monte Carlo studies carried out for nuclear medicine practices within the ORAMED project

The aim of ORAMED work package 4 was the optimization of the medical practices in nuclear medicine during the preparation of radiopharmaceuticals and their administration to the patient. During the project a wide campaign of measurements was performed in the nuclear medicine departments of the collaborating hospitals. Such data were intrinsically characterized by a large variability that depended on the procedure, the employed techniques and the operator's habits. That variability could easily hide some important parameter, for example, the effectiveness of the adopted shielding (for syringe and vial) or the effect of the distances from the source. This information is necessary for a valuable optimization purpose of radiation protection. To this end a sensitivity analysis was carried out through Monte Carlo simulations employing voxel models, representing operator's hand during the considered practices. Such analysis allowed understanding at what extent the range of personal dose equivalent evaluated during measurements can be considered intrinsically related to the procedures. Furthermore, with the Monte Carlo simulations it was possible to study the appropriateness of the shielding usually utilized in these practices.

Iowa EDI Claim and Reporting Compliance Handbook, July 2000

The Iowa EDI Implementation Guide is designed to help any individuals or businesses understand and implement the IAIABC’s Release 2 EDI package. In order to process workers’ compensation claims in Iowa after July 1, 2001, that information will have to be exchanged using EDI as the IAIABC and State of Iowa have standardized. Below are sections that make this process easier to understand.

SlimCodeML: An Optimized Version of CodeML for the Branch-Site Model

CodeML (part of the PAML package) im- plements a maximum likelihood-based approach to de- tect positive selection on a specific branch of a given phylogenetic tree. While CodeML is widely used, it is very compute-intensive. We present SlimCodeML, an optimized version of CodeML for the branch-site model. Our performance analysis shows that SlimCodeML substantially outperforms CodeML (up to 9.38 times faster), especially for large-scale genomic analyses.

Dynamic estimation of three-dimensional cerebrovascular deformation from rotational angiography

Purpose: The objective of this study is to investigate the feasibility of detecting and quantifying 3D cerebrovascular wall motion from a single 3D rotational x-ray angiography (3DRA) acquisition within a clinically acceptable time and computing from the estimated motion field for the further biomechanical modeling of the cerebrovascular wall. Methods: The whole motion cycle of the cerebral vasculature is modeled using a 4D B-spline transformation, which is estimated from a 4D to 2D + t image registration framework. The registration is performed by optimizing a single similarity metric between the entire 2D + t measured projection sequence and the corresponding forward projections of the deformed volume at their exact time instants. The joint use of two acceleration strategies, together with their implementation on graphics processing units, is also proposed so as to reach computation times close to clinical requirements. For further characterizing vessel wall properties, an approximation of the wall thickness changes is obtained through a strain calculation. Results: Evaluation on in silico and in vitro pulsating phantom aneurysms demonstrated an accurate estimation of wall motion curves. In general, the error was below 10% of the maximum pulsation, even in the situation when substantial inhomogeneous intensity pattern was present. Experiments on in vivo data provided realistic aneurysm and vessel wall motion estimates, whereas in regions where motion was neither visible nor anatomically possible, no motion was detected. The use of the acceleration strategies enabled completing the estimation process for one entire cycle in 5-10 min without degrading the overall performance. The strain map extracted from our motion estimation provided a realistic deformation measure of the vessel wall. Conclusions: The authors' technique has demonstrated that it can provide accurate and robust 4D estimates of cerebrovascular wall motion within a clinically acceptable time, although it has to be applied to a larger patient population prior to possible wide application to routine endovascular procedures. In particular, for the first time, this feasibility study has shown that in vivo cerebrovascular motion can be obtained intraprocedurally from a 3DRA acquisition. Results have also shown the potential of performing strain analysis using this imaging modality, thus making possible for the future modeling of biomechanical properties of the vascular wall.

Morphodynamic analysis of cerebral aneurysm pulsation from time-resolved rotational angiography

This paper presents a technique to estimate and model patient-specific pulsatility of cerebral aneurysms over onecardiac cycle, using 3D rotational X-ray angiography (3DRA) acquisitions. Aneurysm pulsation is modeled as a time varying-spline tensor field representing the deformation applied to a reference volume image, thus producing the instantaneousmorphology at each time point in the cardiac cycle. The estimated deformation is obtained by matching multiple simulated projections of the deforming volume to their corresponding original projections. A weighting scheme is introduced to account for the relevance of each original projection for the selected time point. The wide coverage of the projections, together with the weighting scheme, ensures motion consistency in all directions. The technique has been tested on digital and physical phantoms that are realistic and clinically relevant in terms of geometry, pulsation and imaging conditions. Results from digital phantomexperiments demonstrate that the proposed technique is able to recover subvoxel pulsation with an error lower than 10% of the maximum pulsation in most cases. The experiments with the physical phantom allowed demonstrating the feasibility of pulsation estimation as well as identifying different pulsation regions under clinical conditions.

Caracterización socioeconómica y demográfica de niños y adolescentes que estudian y trabajan simultáneamente fuera de casa

Identificar las características socioeconómicas y demográficas de niños y adolescentes que estudiaban y trabajaban simultáneamente fuera de casa. Estudio no-experimental, correlacional, de delineación transversal. Se aplicó cuestionario a alumnos de enseñanza primaria matriculados en escuelas públicas de Ribeirão Preto-SP (Brasil). Dos escuelas fueron sorteadas. Se utilizó Statistical Package of Social Sciences, versión 14,0 para análisis de datos. De los 133 estudiantes que respondieron el cuestionario, 36 (27,7%) refirieron trabajar fuera de casa, 20,6% tenía 11 y 13 años, 66,7% eran de sexo masculino (p=0,000) y comenzaron a trabajar precozmente para sumar a la renta familiar (p=0,003). El salario recibido se aplicaba a la mejora de la renta familiar, constatándose que si dicha renta aumentaba, la presencia del joven en su trabajo disminuía. Se evidenció que muchos factores contribuyen en la inserción precoz de estos sujetos en el mercado laboral, tales como el tamaño, la estructura familiar y la pobreza.

Transtorno afetivo bipolar: perfil farmacoterapêutico e adesão ao medicamento

Este estudo teve como objetivos verificar a adesão de portadores de transtorno afetivo bipolar (TAB) à terapêutica medicamentosa e identificar possíveis causas de adesão e não adesão ao medicamento de acordo com o perfil farmacoterapêutico. Trata-se de estudo transversal, descritivo, realizado em Núcleo de Saúde Mental de um município do interior paulista. Participaram do estudo 101 pacientes com TAB. Para coleta dos dados, utilizou-se a entrevista estruturada e o teste de Morisky-Green e, para a análise dos mesmos, o programa Statistical Package for the Social Science. Os resultados mostraram que a maioria (63%) dos sujeitos investigados não adere ao medicamento. Apesar de não ter ocorrido diferenças significativas entre o grupo de aderentes e não aderentes, para as variáveis investigadas, foi possível verificar a utilização de polifarmacoterapia e regimes terapêuticos complexos no tratamento do TAB. Permanece como desafio a implementação de estratégias que possam melhorar, na prática, a adesão de pacientes ao tratamento medicamentoso.

Human Capital, the Structure of Production, and Growth

Recent decisions by the Spanish national competition authority (TDC) mandate payment systems to include only two costs when setting their domestic multilateral interchange fees (MIF): a fixed processing cost and a variable cost for the risk of fraud. This artificial lowering of MIFs will not lower consumer prices, because of uncompetitive retailing; but it will however lead to higher cardholders fees and, likely, new prices for point of sale terminals, delaying the development of the immature Spanish card market. Also, to the extent that increased cardholders fees do not offset the fall in MIFs revenue, the task of issuing new cards will be underpaid relatively to the task of acquiring new merchants, causing an imbalance between the two sides of the networks. Moreover, the pricing scheme arising from the decisions will cause unbundling and underprovision of those services whose costs are excluded. Indeed, the payment guarantee and the free funding period will tend to be removed from the package of services currently provided, to be either provided by third parties, by issuers for a separate fee, or not provided at all, especially to smaller and medium-sized merchants. Transaction services will also suffer the consequences that the TDC precludes pricing them in variable terms.

Qualidade de vida de pacientes com câncer hematológico em tratamento quimioterápico

Estudo descritivo, transversal desenvolvido com objetivo de associar aspectos socio demográficos e clínicos aos domínios de qualidade de vida relacionada à saúde (QVRS), para avaliar pacientes onco-hematológicos submetidos à quimioterapia. Na coleta de dados utilizou-se um instrumento sociodemográfico e clínico e o European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC) QLQ-C-30. A amostra foi constituída de 32 pacientes, sendo oito (25%) com diagnóstico de linfoma de Hodgkin, nove (28,12%) linfoma não Hodgkin e 15 (46,87%) leucemia. Os dados foram analisados pelo software Statistical Package for Social Science (SPSS). O QLQ-C-30 mostrou média das funções física, cognitiva, emocional, social e desempenho de papel de 54,81 a 41,18, demonstrando um nível pouco satisfatório. Nas escalas de sintomas, houve predomínio de fadiga média 64,57 seguida de insônia (56,90) e perda de apetite (50,71). Esses sintomas interferiram nas funções físicas, emocionais e cognitivas demonstrando que efeitos colaterais do tratamento influenciam negativamente na QVRS dos pacientes.

Paediatric cardiac CT examinations: impact of the iterative reconstruction method ASIR on image quality--preliminary findings.

BACKGROUND: Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. OBJECTIVE: To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. MATERIALS AND METHODS: Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDI(vol) 4.8-7.9 mGy, DLP 37.1-178.9 mGy·cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. RESULTS: The best image quality for all clinical images was obtained with 20% and 40% ASIR (p < 0.001) whereas with ASIR above 50%, image quality significantly decreased (p < 0.001). With 100% ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. CONCLUSION: Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone.

Iowa Technology Governance Board Annual Report, January 8, 2007

This Technology Governance Board Annual Report provides information o the total annual executive branch information technology expenditures (hardware, software, and personnel) and estimates for the amount of technology spending to be requested for the succeeding fiscal year. The report contains a projection of technology cost savings, an accounting of the level of technology cost savings for the current fiscal year, and a comparison of the level of technology cost savings for the current fiscal year with that of the previous fiscal year. This report was produced in compliance with Iowa Code §8A.204(3a) and was submitted to the Governor, the Department of Management, and the General Assembly on January 8, 2007.

Midwest Regional Rail Passenger Initiative Status Report December 2006

This report is submitted as required per Code of Iowa section 327J.3(5), "The director shall report annually to the general assembly concerning the development and operation of the midwest regional rail system and the state's passenger rail service." The Midwest Regional Rail Initiative (MWRRI) is a nine-state effort to develop an implementation plan for a 3,000-mile, high-speed rail system hubbed in Chicago. Studies done since 1996 have concluded that such a regional system, including a line from Chicago to Omaha through Davenport, Iowa City and Des Moines, is viable. Most of the system would be upgraded to allow 110 mile-per-hour service. Some low volume lines, including the Iowa portions, would be upgraded for 79 mile-per-hour service. The nine-state coalition released an updated 2004 executive report for the system. As reported, the updated cost estimate for the Chicago to Omaha corridor, which includes a branch to Quincy, Ill., is $638 million for infrastructure and $167 million for rolling stock. These costs are higher than first estimated in 1998 and are given in 2002 dollars, (not adjusted for the cost of inflation). Operating subsidies would be required during an extended start-up phase. The allocation of these subsidy costs among the various states has not been determined, and is still a subject for analysis and negotiation. Little progress on implementation is expected unless a federal funding package is passed for passenger rail initiatives. Continued congressional discussion on policy directions relative to Amtrak clouds the issue of passenger rail funding. However, Congress is expected to address passenger rail issues and funding in 2007. Participation of the Iowa Department of Transportation in the MWRRI is authorized under Iowa Code section 327J.3.

Qualidade de Serviço numa unidade Hoteleira em São Vicente

A satisfação dos clientes é uma forma das empresas se manterem no mercado a partir da conquista dos seus parceiros comerciais, por isso o tema satisfação ganhou maior importância no contexto da administração de empresas. Dado o crescente fenómeno competitivo da indústria hoteleira, o objectivo deste estudo foi aumentar a compreensão das percepções sobre a qualidade do serviço de um hotel, da perspectiva dos seus consumidores. Além disso, este estudo também pretendeu explorar a relação entre a satisfação global e nove factores de qualidade num serviço sendo eles: “higiene e limpeza”, “decoração”, “conforto”, “funcionários”, “alimentação”, “animação”, “serviços de apoio”, “quarto”, e “relação qualidade/preço”. Esta pesquisa acedeu as percepções da qualidade do serviço no hotel através da aplicação de um questionário abrangendo uma amostra de 16 respondentes (hospedes que de livre vontade responderam ao questionário). Os dados recolhidos foram analisados em SPSS (Statistical Package for Social Sciences). Verificamos os seguintes resultados: São o conforto (primeiro lugar), a higiene e limpeza (em segundo) e os serviços de apoio (em terceiro) que mais influenciam a satisfação global no hotel. Costumer’s satisfaction is one way for companies to keep in the market by the conquest of its trading partners; hence, the theme of satisfaction gained greater importance in the context of business administration lately. Given the increasing competitive phenomenon in the touristic industry, the aim of this study was to increase the comprehension of perceptions towards hotel service quality from the hotel customer’s perspective. Besides, this study also intended to explore the relationship between the overall satisfaction and nine service quality factors, namely: “cleanness”, “decoration”, “comfort”, “staff”, and “food/beverage”, “entertainment” “support services”, “rooms and “relation quality/price”. This research assessed the ‘perceptions of service quality’ by applying a questionnaire comprising a sample of 16 guests that responded it correctly. Data collected was analyzed using SPSS - (Statistical Package for Social Sciences). The results indicated the following: comfort (in the first place), cleanness (in the second) and support services (in the third) are the factors that most influence the overall satisfaction in a hotel.