Search results for "030218 nuclear medicine & medical imaging"
showing 10 items of 1054 documents
The 15-Country Collaborative Study of Cancer Risk Among Radiation Workers in the Nuclear Industry: design, epidemiological methods and descriptive re…
2007
International audience; Radiation protection standards are based mainly on risk estimates from studies of atomic bomb survivors in Japan. The validity of extrapolations from the relatively high-dose acute exposures in this population to the low-dose, protracted or fractionated environmental and occupational exposures of primary public health concern has long been the subject of controversy. A collaborative retrospective cohort study was conducted to provide direct estimates of cancer risk after low-dose protracted exposures. The study included nearly 600,000 workers employed in 154 facilities in 15 countries. This paper describes the design, methods and results of descriptive analyses of th…
Endovascular stentectomy using the snare over stent-retriever (SOS) technique: An experimental feasibility study
2017
PLoS one 12(5), e0178197 (2017). doi:10.1371/journal.pone.0178197
Weighted Likelihood Function of Multiple Statistical Parameters to Retrieve 2D TRUS-MR Slice Correspondece for Prostate Biopsy
2012
International audience; This paper presents a novel method to identify the 2D axial Magnetic Resonance (MR) slice from a pre-acquired MR prostate volume that closely corresponds to the 2D axial Transrectal Ultrasound (TRUS) slice obtained during prostate biopsy. The shape-context representations of the segmented prostate contours in both the imaging modalities are used to establish point correspondences using Bhattacharyya distance. Thereafter, Chi-square distance is used to find the prostate shape similarities between the MR slices and the TRUS slice. Normalized mutual information and correlation coefficient between the TRUS and MR slices are computed to find the information theoretic simi…
A hybrid framework of multiple active appearance models and global registration for 3D prostate segmentation in MRI.
2012
International audience; Real-time fusion of Magnetic Resonance (MR) and Trans Rectal Ultra Sound (TRUS) images aid in the localization of malignant tissues in TRUS guided prostate biopsy. Registration performed on segmented contours of the prostate reduces computational complexity and improves the multimodal registration accuracy. However, accurate and computationally efficient 3D segmentation of the prostate in MR images could be a challenging task due to inter-patient shape and intensity variability of the prostate gland. In this work, we propose to use multiple statistical shape and appearance models to segment the prostate in 2D and a global registration framework to impose shape restri…
Texture analysis for infarcted myocardium detection on delayed enhancement MRI
2017
Detection of infarcted myocardium in the left ventricle is achieved with delayed enhancement magnetic resonance imaging (DE-MRI). However, manual segmentation is tedious and prone to variability. We studied three texture analysis methods (run-length matrix, co-occurrence matrix, and autoregressive model) in combination with histogram features to characterize the infarcted myocardium. We evaluated 10 patients with chronic infarction to select the most discriminative features and to train a support vector machine (SVM) classifier. The classifier model was then used to segment five human hearts from the STACOM DE-MRI challenge at MICCAI 2012. The Dice coefficient was used to compare the segmen…
Vom Röntgen zum PET/MRT, und dann? – Zukunftsweisende Bildgebung in der Kinderradiologie
2019
Die Kinderradiologie steht heute vor weitreichenden Veränderungen. Basismodalitäten wie Röntgen und Ultraschall werden zunehmend durch neuere, moderne Techniken ergänzt. Dieser Übersichtsartikel stellt Fortschritte in der Kinderradiologie sowie technische Innovationen vor, welche in Zukunft noch größere Bedeutung erlangen könnten. Hierzu werden CT-Dosisreduktionstechniken inklusive der Anwendung künstlicher Intelligenz sowie Fortschritte in den Gebieten der Magnetresonanztomografie und molekularen Bildgebung dargestellt. Kernaussagen
A generic TG-186 shielded applicator for commissioning model-based dose calculation algorithms for high-dose-rate Ir-192 brachytherapy
2017
PurposeA joint working group was created by the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) with the charge, among others, to develop a set of well-defined test case plans and perform calculations and comparisons with model-based dose calculation algorithms (MBDCAs). Its main goal is to facilitate a smooth transition from the AAPM Task Group No. 43 (TG-43) dose calculation formalism, widely being used in clinical practice for brachytherapy, to the one proposed by Task Group No. 186 (TG-186) for MBDCAs. To do so, in this work a hypothetical, generic high-dose rate (HDR) Ir-19…
Factor analysis-based approach for early uptake automatic quantification of breast cancer by 18F-FDG PET images sequence
2014
International audience; Factor Analysis of Medical Image Sequences (FAMIS) is recognized as one pioneer successfully used approach for analyzing especially dynamic images' sequence for estimating kinetics and associated compartments having a physiological meaning. Some studies tried to extend the exploring of this approach to analyze Positron Emission Tomography (PET) image modality for dynamic sequences. PET images with 18F-fluorodesoxyglucose (18F-FDG) is the gold standard for in vivo, evaluation of tumor glucose metabolism and is widely used in clinical oncology. In this paper, a novel approach is proposed to obtain an automated quantification method for early accumulation of 18F-FDG tra…
Quantifying multidimensional control mechanisms of cardiovascular dynamics during multiple concurrent stressors
2021
Heartbeat regulation is achieved through different routes originating from central autonomic network sources, as well as peripheral control mechanisms. While previous studies successfully characterized cardiovascular regulatory mechanisms during a single stressor, to the best of our knowledge, a combination of multiple concurrent elicitations leading to the activation of different autonomic regulatory routes has not been investigated yet. Therefore, in this study, we propose a novel modeling framework for the quantification of heartbeat regulatory mechanisms driven by different neural routes. The framework is evaluated using two heartbeat datasets gathered from healthy subjects undergoing p…
Imaging of hepatic hemangioma: from A to Z
2019
The hemangioma is the most common solid lesion of the liver. Therefore, radiologists must know the typical and atypical imaging findings of this lesion in order to reach a correct diagnosis and avoid diagnostic errors. However, only few papers have comprehensively described the entire spectrum of atypical and uncommon imaging features. In this updated review, we provide the imaging features of hepatic hemangioma, in both typical and atypical forms, as well as its association with abnormalities in the adjacent hepatic parenchyma and other hepatic lesions, and its complications.