12 research outputs found

    Learn2Reg: comprehensive multi-task medical image registration challenge, dataset and evaluation in the era of deep learning

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    Image registration is a fundamental medical image analysis task, and a wide variety of approaches have been proposed. However, only a few studies have comprehensively compared medical image registration approaches on a wide range of clinically relevant tasks. This limits the development of registration methods, the adoption of research advances into practice, and a fair benchmark across competing approaches. The Learn2Reg challenge addresses these limitations by providing a multi-task medical image registration data set for comprehensive characterisation of deformable registration algorithms. A continuous evaluation will be possible at https://learn2reg.grand-challenge.org. Learn2Reg covers a wide range of anatomies (brain, abdomen, and thorax), modalities (ultrasound, CT, MR), availability of annotations, as well as intra- and inter-patient registration evaluation. We established an easily accessible framework for training and validation of 3D registration methods, which enabled the compilation of results of over 65 individual method submissions from more than 20 unique teams. We used a complementary set of metrics, including robustness, accuracy, plausibility, and runtime, enabling unique insight into the current state-of-the-art of medical image registration. This paper describes datasets, tasks, evaluation methods and results of the challenge, as well as results of further analysis of transferability to new datasets, the importance of label supervision, and resulting bias. While no single approach worked best across all tasks, many methodological aspects could be identified that push the performance of medical image registration to new state-of-the-art performance. Furthermore, we demystified the common belief that conventional registration methods have to be much slower than deep-learning-based methods

    Strategic Thinking and Risk Attitude

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    WOS: 000444687500014In recent years, strategic thinking and risk attitude are demonstrated among the most interesting topics in strategic management literature. However, when the literature on the subject is examined, it is seen that there is not enough comprehensive correlational studies, although it is understood that there is significant logical linking between the two subjects. The purpose of this study is to explore the relationships between strategic thinking and risk attitude, to carry out a pioneering step towards filling this gap in the literature and to encourage further work. Qualitative research method will be used in the study and conceptual association will be done by analyzing the secondary sources with the document review technique

    Toward automatic regional analysis of pulmonary function using inspiration and expiration thoracic CT.

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    Item does not contain fulltextPURPOSE: To analyze pulmonary function using a fully automatic technique which processes pairs of thoracic CT scans acquired at breath-hold inspiration and expiration, respectively. The following research objectives are identified to: (a) describe and systematically analyze the processing pipeline and its results; (b) verify that the quantitative, regional ventilation measurements acquired through CT are meaningful for pulmonary function analysis; (c) identify the most effective of the calculated measurements in predicting pulmonary function; and (d) demonstrate the potential of the system to deliver clinically important information not available through conventional spirometry. METHODS: A pipeline of automatic segmentation and registration techniques is presented and demonstrated on a database of 216 subjects well distributed over the various stages of COPD (chronic obstructive pulmonary disorder). Lungs, fissures, airways, lobes, and vessels are automatically segmented in both scans and the expiration scan is registered with the inspiration scan using a fully automatic nonrigid registration algorithm. Segmentations and registrations are examined and scored by expert observers to analyze the accuracy of the automatic methods. Quantitative measures representing ventilation are computed at every image voxel and analyzed to provide information about pulmonary function, both globally and on a regional basis. These CT derived measurements are correlated with results from spirometry tests and used as features in a kNN classifier to assign COPD global initiative for obstructive lung disease (GOLD) stage. RESULTS: The steps of anatomical segmentation (of lungs, lobes, and vessels) and registration in the workflow were shown to perform very well on an individual basis. All CT-derived measures were found to have good correlation with spirometry results, with several having correlation coefficients, r, in the range of 0.85-0.90. The best performing kNN classifier succeeded in classifying 67% of subjects into the correct COPD GOLD stage, with a further 29% assigned to a class neighboring the correct one. CONCLUSIONS: Pulmonary function information can be obtained from thoracic CT scans using the automatic pipeline described in this work. This preliminary demonstration of the system already highlights a number of points of clinical importance such as the fact that an inspiration scan alone is not optimal for predicting pulmonary function. It also permits measurement of ventilation on a per lobe basis which reveals, for example, that the condition of the lower lobes contributes most to the pulmonary function of the subject. It is expected that this type of regional analysis will be instrumental in advancing the understanding of multiple pulmonary diseases in the future.1 maart 201

    Free press and fair trial: The role of behavioral research.

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    Suggests that current case law and legal codes concerning media coverage of trials are inconsistent and provide insufficient guidance to judges in their use of restraints and remedies. In addition, it is contended that there currently does not exist adequate empirical research on the impact of news coverage and juror behavior. Legal issues involving free press and fair trial are discussed in relation to research on the nature and extent of news coverage of crime, the potential prejudicial impact of news coverage in actual cases, and simulation studies on the effects of judicial remedies. It is argued that carefully conducted empirical research could provide important information to the courts. Research directions and methodological caveats to increase legal relevance and scientific validity are suggested

    School Guidance and Counseling Program Outcomes and Measures for Their Assessment

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