Relevant bibliographies by topics / Ultra-short echo time (UTE)

Academic literature on the topic 'Ultra-short echo time (UTE)'

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Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Ultra-short echo time (UTE)"

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Williams, A., Y. Qian, D. Bear, and C. R. Chu. "Assessing degeneration of human articular cartilage with ultra-short echo time (UTE) T2* mapping." Osteoarthritis and Cartilage 18, no. 4 (April 2010): 539–46. http://dx.doi.org/10.1016/j.joca.2010.02.001.

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Bracher, Anna-Katinka, Christian Hofmann, Axel Bornstedt, Saïd Boujraf, Erich Hell, Johannes Ulrici, Axel Spahr, Bernd Haller, and Volker Rasche. "Feasibility of ultra-short echo time (UTE) magnetic resonance imaging for identification of carious lesions." Magnetic Resonance in Medicine 66, no. 2 (February 28, 2011): 538–45. http://dx.doi.org/10.1002/mrm.22828.

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Delacoste, Jean, Jerome Chaptinel, Catherine Beigelman‐Aubry, Davide Piccini, Alain Sauty, and Matthias Stuber. "A double echo ultra short echo time (UTE) acquisition for respiratory motion‐suppressed high resolution imaging of the lung." Magnetic Resonance in Medicine 79, no. 4 (August 30, 2017): 2297–305. http://dx.doi.org/10.1002/mrm.26891.

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Łopuszyńska, Natalia, Krzysztof Szczepanowicz, Krzysztof Jasiński, Piotr Warszyński, and Władysław P. Węglarz. "Effective Detection of Nafion®-Based Theranostic Nanocapsules Through 19F Ultra-Short Echo Time MRI." Nanomaterials 10, no. 11 (October 26, 2020): 2127. http://dx.doi.org/10.3390/nano10112127.

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The application of the Three-Dimensional Ultra-Short Echo Time (3D UTE)pulse sequence at a high magnetic field for visualization of the distribution of 19F loaded theranostic core-shell nanocapsules with Nafion® (1,1,2,2-tetrafluoroethene; 1,1,2,2-tetrafluoro-2- [1,1,1,2,3,3-hexafluoro-3-(1,2,2-trifluoroethenoxy)propan-2-yl] oxyethanesulfonic acid) incorporated into the shell is presented. The nanocarriers were formed via the layer-by-layer technique with biodegradable polyelectrolytes: PLL (Poly-L-lysine), and with Nafion®: polymer with high 19F content. Before imaging, an MR (magnetic resonance) spectroscopy and T1 and T2 measurements were performed, resulting in values of T2 between 1.3 ms and 3.0 ms, depending on the spectral line. To overcome limitations due to such short T2, the 3D UTE pulse sequence was applied for 19F MR imaging. First Nafion® solutions of various concentrations were measured to check the detection limit of our system for the investigated molecule. Next, the imaging of a phantom containing core-shell nanocapsules was performed to assess the possibility of visualizing their distribution in the samples. Images of Nafion® containing samples with SNR ≥ 5 with acquisition time below 30 min for 19F concentration as low as 1.53 × 10−2 mmol 19F/g of sample, were obtained. This is comparable with the results obtained for molecules, which exhibit more preferable MR characteristics.
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Tbini, Zeineb, Mokhtar Mars, and Mouna Bouaziz. "T1 Relaxation Time of Achilles Tendon at 3 Tesla with Special Reference to Relevant Clinical Score: A Preliminary Study." Current Medical Imaging Formerly Current Medical Imaging Reviews 16, no. 2 (January 24, 2020): 164–73. http://dx.doi.org/10.2174/1573405615666181205130816.

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Purpose: The purpose of this study was to investigate T1 relaxation time of the human Achilles tendon, to test its short-term repeatability as well as the minimal detectable change, and to assess the extent that correlate with clinical symptoms. Methods: Twenty asymptomatic volunteers and eighteen patients with clinically and sonographically confirmed tendinopathy were scanned for ankle using a 3 Tesla (T) MR scanner. T1 maps were calculated from a variable flip angle gradient echo Ultra-short echo time sequence (VFA-GE UTE) and inversion recovery spin echo sequence (IR-SE) using a self-developed matlab algorithm in three regions of interest of Achilles Tendon (AT). Signal to Noise Ratio (SNR) between the two sequences was evaluated. INTRA-class Correlation Coefficient (ICC), Coefficient of Variation (CV) and the Least Significant Change (LSC) were calculated, to test short-term repeatability of T1. Subjects were assessed by the VISA-A clinical score. P values less than 0.005 were considered statistically significant. Results: Mean T1 values were 427.09 ± 53.37 ms and 528.70 ± 103.50 ms using IR-SE sequence and 575.43 ± 110.60 ms and 875.81 ± 425.77 ms with VFA-GE UTE sequence in the whole AT for volunteers and patients, respectively. : T1 values showed a significant difference between volunteers and patients (P=0.001). Regional variation of T1 in healthy and tendinopathic AT were greater for VFA-GE UTE sequence than for IR-SE sequence. VFA-GE UTE sequence showed clearly higher SNR compared to IR-SE sequence. Short-term repeatability of T1 values for volunteers showed an LSC of 22% and 14% for IR-SE sequence and VFA-GE UTE sequence, respectively. For patients, LSC was 14% and 5% for IR-SE sequence and VFA-GE UTE sequence, respectively. There was no correlation between T1 and VISA-A clinical score (p>0.005). Conclusion: VFA-GE UTE sequence used for T1 mapping calculation demonstrated short acquisition time and clearly high SNR. Results revealed that T1 relaxation time can be used as a biomarker to differentiate between healthy and pathologic Achilles tendon. However, T1 showed no correlation with the VISA-A clinical score.
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Delacoste, Jean, Helene Feliciano, Jérôme Yerly, Vincent Dunet, Catherine Beigelman‐Aubry, Giulia Ginami, Ruud B. van Heeswijk, Davide Piccini, Matthias Stuber, and Alain Sauty. "A black‐blood ultra‐short echo time (UTE) sequence for 3D isotropic resolution imaging of the lungs." Magnetic Resonance in Medicine 81, no. 6 (February 8, 2019): 3808–18. http://dx.doi.org/10.1002/mrm.27679.

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Schwaiger, Benedikt J., Charlotte Schneider, Sophia Kronthaler, Florian T. Gassert, Christof Böhm, Daniela Pfeiffer, Thomas Baum, et al. "CT-like images based on T1 spoiled gradient-echo and ultra-short echo time MRI sequences for the assessment of vertebral fractures and degenerative bone changes of the spine." European Radiology 31, no. 7 (January 14, 2021): 4680–89. http://dx.doi.org/10.1007/s00330-020-07597-9.

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Abstract Objectives To evaluate the performance of 3D T1w spoiled gradient-echo (T1SGRE) and ultra-short echo time (UTE) MRI sequences for the detection and assessment of vertebral fractures and degenerative bone changes compared with conventional CT. Methods Fractures (n = 44) and degenerative changes (n = 60 spinal segments) were evaluated in 30 patients (65 ± 14 years, 18 women) on CT and 3-T MRI, including CT-like images derived from T1SGRE and UTE. Two radiologists evaluated morphological features on both modalities: Genant and AO/Magerl classifications, anterior/posterior vertebral height, fracture age; disc height, neuroforaminal diameter, grades of spondylolisthesis, osteophytes, sclerosis, and facet joint degeneration. Diagnostic accuracy and agreement between MRI and CT and between radiologists were assessed using crosstabs, weighted κ, and intraclass correlation coefficients. Image quality was graded on a Likert scale. Results For fracture detection, sensitivity, specificity, and accuracy were 0.95, 0.98, and 0.97 for T1SGRE and 0.91, 0.96, and 0.95 for UTE. Agreement between T1SGRE and CT was substantial to excellent (e.g., Genant: κ, 0.92 [95% confidence interval, 0.83–1.00]; AO/Magerl: κ, 0.90 [0.76–1.00]; osteophytes: κ, 0.91 [0.82–1.00]; sclerosis: κ, 0.68 [0.48–0.88]; spondylolisthesis: ICCs, 0.99 [0.99–1.00]). Agreement between UTE and CT was lower, ranging from moderate (e.g., sclerosis: κ, 0.43 [0.26–0.60]) to excellent (spondylolisthesis: ICC, 0.99 [0.99–1.00]). Inter-reader agreement was substantial to excellent (0.52–1.00), respectively, for all parameters. Median image quality of T1SGRE was rated significantly higher than that of UTE (p < 0.001). Conclusions Morphologic assessment of bone pathologies of the spine using MRI was feasible and comparable to CT, with T1SGRE being more robust than UTE. Key Points • Vertebral fractures and degenerative bone changes can be assessed on CT-like MR images, with 3D T1w spoiled gradient-echo–based images showing a high diagnostic accuracy and agreement with CT. • This could enable MRI to precisely assess bone morphology, and 3D T1SGRE MRI sequences may substitute additional spinal CT examinations in the future. • Image quality and robustness of T1SGRE sequences are higher than those of UTE MRI for the assessment of bone structures.
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Tang, Peng, Jingtao Xu, Wei Liu, Yu Li, Wei Fan, and Xiaoliang Huang. "Study of the Feasibility of Conventional MR Images and Magnetic Resonance (MR)/Ultra-Short Echo Time (UTE) Technique in the Evaluation of Lumbar Disc Degeneration in the Axial Plane." Journal of Medical Imaging and Health Informatics 11, no. 3 (March 1, 2021): 817–21. http://dx.doi.org/10.1166/jmihi.2021.3360.

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The advantage and value of magnetic resonance (MR)-ultra-short echo time (UTE) technique in the displaying the structures of degenerative intervertebral discs were observed through evaluating the lumbar disc degeneration in the axial plane by conventional MR image and MR-UTE technique. A total of 160 examinees screened by inclusion and exclusion criteria were enrolled, and a total of 800 intervertebral disks were involved, and the degree of intervertebral disc degeneration was classified by conventional MR image classification method. After the first echo image of MR-UTE technique was integrated with the contour, the image entered UTE cartilage endplate, fibrous ring and osseous endplate. The integrity of the intervertebral disc from the above and below the intervertebral disc and the correlation of the structural endplate with the integrities of cartilage endplate, fibrous ring and osseous endplate under double echo sequence were analyzed, and the correlation analysis of the two categorical variables was conducted using rank correlation analysis. Under the MR-UTE sequence, there was no statistical significant difference in structural integrity constituent ratio (intact structure only on one side, incomplete structure on both side) between the non-low back pain group and the low back pain group (P > 0.05), the proportion of complete structure disappearance was lowest, and the proportion of partial structure disappearance was highest; there was a significant difference in the structural integrity of fibrous ring between the non-low back pain group and the low back pain group (P < 0.05), there was a statistical significant difference in structural integrity of fibrous rings between the two groups (P < 0.05); there was a statistical significant difference in pain degree between the partial structure disappearance group and the complete structure disappearance group (P < 0.05). There was no significant difference in pain degree between the groups (intact structure only on one side and incomplete structure on both side); conventional MR images showed no significant difference in the intervertebral disc degeneration degree between the non-low back pain group and low back pain group (P > 0.05), and the intervertebral disc degeneration degree had no significant correlation with the lower back pain. MR-UTE sequence and T2WI sequence showed that there was a correlation between different intervertebral disc degeneration degrees and the structural integrity distributions of cartilage endplate, osseous endplate and fibrous rings in two groups of patients with or without low back pain (P < 0.05). Whether low back pain exists or not has little effect on the intervertebral disc degeneration degree on T2WI. MR-UTE double echo sequence scan reveals that the intervertebral disc degeneration degree is positively related to the integrity and integrity distribution of cartilage endplate, fibrous ring and bone endplate.
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Takahashi, Masaya, Osamu Togao, Makoto Obara, Marc van Cauteren, Yoshiharu Ohno, Shigehiro Doi, Makoto Kuro-O, Craig Malloy, Connie C. Hsia, and Ivan Dimitrov. "Ultra-short echo time (UTE) MR imaging of the lung: Comparison between normal and emphysematous lungs in mutant mice." Journal of Magnetic Resonance Imaging 32, no. 2 (July 22, 2010): 326–33. http://dx.doi.org/10.1002/jmri.22267.

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Geibel, Margit-Ann, Benjamin Gelißen, Anna-Katinka Bracher, and Volker Rasche. "Artifact Properties of Dental Ceramic and Titanium Implants in MRI." RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren 191, no. 05 (November 12, 2018): 433–41. http://dx.doi.org/10.1055/a-0755-2374.

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Aim Assessment of the visualization of titanium and ceramic dental implants using various isotropic three-dimensional magnetic resonance imaging (MRI) methods. Materials and Methods 21 dental implants (7 ceramic, 14 titanium) were scanned in vitro with a spatially isotropically resolved three-dimensional gradient echo (FFE), a turbo spin echo (SE) and an ultra-short-echo time (UTE) imaging technique. The resulting absolute volumes of the implants were quantified and the relative error to the theoretical volume was calculated. Results Ceramic implants and their periphery could be displayed well in all cases. The observed mean relative error results were 5.4 ± 2.3 % (UTE) to 6.5 ± 4.3 % (FFE). No significant difference was observed between the investigated MRI methods. The transition between implant and surrounding agarose could be shown in all cases without artifacts. Titanium implants resulted in mean relative errors between 1314 ± 350 % (FFE) and 2157 ± 810 % (SE). Here, significant differences were observed between the FFE and the SE and between the UTE and the SE sequence. The periphery of the implants could not be displayed in any case. Conclusion Use of the MRI technique for the diagnosis of peri-implantitis, the assessment of anatomical structures and planning of dental implantation is currently very limited but could be used more frequently, provided there are no disturbing or imaging-disturbing materials in the region of interest. MRI technology is not suitable in case of titanium implants. When using ceramic implants, MRI technology is an option. Key points Citation Format
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Dissertations / Theses on the topic "Ultra-short echo time (UTE)"

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Nazaran, Amin. "Ultra Short MR Relaxometry and Histological Image Processing for Validation of Diffusion MRI." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6348.

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Magnetic Resonance Imaging (MRI) is an imaging modality that acquires an image with little to no damage to the tissue. MRI does not introduce foreign particles or high energy radiation into the body, making it one of the least invasive medical imaging modalities. MRI can achieve excellent soft tissue contrast and is therefore useful for diagnosis of a wide variety of diseases. While there are a wide variety of available techniques for generating contrast in MRI, there are still many open areas for research. For example, many tissues in the human body exhibit such rapid signal decay that they are difficult to image with MRI: they are "MRI invisible". Furthermore, some of the newer MRI imaging techniques have not been fully validated to ensure that they are truly revealing accurate information about the underlying anatomical microstructure that they purport to image. This dissertation focuses on the development of new techniques in two distinct areas. First, a novel method for accurately assessing the MRI signal decay properties of tissues that are normally MRI invisible, such as tendons, ligaments, and certain pathological chemical deposits in the brain, is presented. This is termed "ultrashort MRI relaxometry". Second, two new image processing algorithms that operate on high resolution images of stained histological slices of the ex vivo brain are presented. The first of these image processing algorithms allows the semi-automated extraction of nerve fiber directionality from the histological slice images, a process that is normally done manually, is incredibly time consuming, and is prone to human error. This new technique represents one significant step in the complicated problem of attempting to validate a popular MRI technique, Diffusion Tensor Imaging (DTI), by ensuring that DTI results correlate with the true underlying physiology revealed by histological slicing and staining. The second of these image processing algorithms attempts to extract and segment regions of different "cytoarchitectonic characteristics" from stained histological slices of ex vivo brain. Again, traditional cytoarchitectonic segmentation relies on manual segmentation by an expert neuroanatomist, which is slow and sometimes inconsistent. The new technique is a first step towards automated this process, potentially providing greater accuracy and repeatability of the segmentations in a much shorter time. Together, these contributions represent a significant contribution to the body of MR imaging techniques, and associated image processing techniques for validation of newer MR neuroimaging techniques against the gold standard of stained histological slices of ex vivo brain.
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Bianchi, Andrea. "Magnetic resonance imaging techniques for pre-clinical lung imaging." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0060/document.

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Dans ce travail, les s´séquences Imagerie par Résonance Magnétique (IRM) radiales à temps d’écho ultra-court (UTE) sont analysées pour évaluer leur potentiel dans l’étude non-invasive de différents modèles expérimentaux de maladies pulmonaires chez la souris. Chez le petit animal, les séquences radiales UTE peuvent efficacement limiter l’impact négatif sur la qualité de l’image dû au déphasage rapide des spins causé par les nombreuses interfaces air/tissu. En plus, les séquences radiales UTE sont moins sensibles aux artefacts de mouvement par rapport aux séquences Cartésiennes classiques. En conséquence, chez le petit animal, les séquences radiales UTE peuvent permettre d’obtenir des images du poumon avec une résolution bien inférieure au millimètre avec des rapports signal/bruit importants dans le parenchyme pulmonaire, tout en travaillant en conditions physiologiques (animaux en respiration spontanée). Dans cette thèse, il sera démontré que les séquences d’IRM protonique UTE sont outils efficaces dans l’étude quantitative et non-invasive de différents marqueurs distinctifs de certaines pathologies pulmonaires d’intérêt général. Les protocoles développés serontsimples, rapides et non-invasifs, faciles à implémenter, avec une interférence minimale sur la pathologie pulmonaire étudiée et, en définitive, potentiellement applicables chez l’homme. Il sera ainsi démontré que l’emploi des agents de contraste, administrés via les voies aériennes, permet d’augmenter la sensibilité des protocoles développés. Parallèlement, dans cette thèse des protocoles suffisamment flexibles seront implémentés afin de permettre l’étude d’un agent de contraste paramagnétique générique pour des applications aux poumons
In this work, ultra-short echo time (UTE) Magnetic Resonance Imaging (MRI) sequences are investigated as flexible tools for the noninvasive study of experimental models of lung diseases in mice. In small animals radial UTE sequences can indeed efficiently limit the negative impact on lung image quality due to the fast spin dephasing caused by the multiple air/tissue interfaces. In addition, radial UTE sequences are less sensitive to motion artifacts compared to standard Cartesian acquisitions. As a result, radial UTE acquisitions can provide lung images in small animals at sub-millimetric resolution with significant signal to noise ratio in the lung parenchyma, while working with physiological conditions (freely-breathing animals). In this thesis, UTE proton MRI sequences were shown to be efficient instruments to quantitatively investigate a number of hallmarks in longitudinal models of relevant lung diseases with minimal interference with the lung pathophysiology, employing easilyimplementable fast protocols. The synergic use of positive contrast agents, along with anadvantageous administration modality, was shown to be a valuable help in the increase of sensitivity of UTE MRI. At the same time, UTE MRI was shown to be an extremely useful and efficacious sequence for studying positive contrast agents in lungs
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Hofmann, Christian [Verfasser]. "Applicability of three-dimensional ultra-short echo time magnetic resonance imaging for in vivo assessment of caries lesions and early demineralization / Christian Hofmann." Ulm : Universität Ulm. Medizinische Fakultät, 2014. http://d-nb.info/1052062377/34.

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Araujo, Ericky Caldas de Almeida. "Adaptation of Proof of Concepts Into Quantitative NMR Methods : Clinical Application for the Characterization of Alterations Observed in the Skeletal Muscle Tissue in Neuromuscular Disorders." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112075/document.

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Actuellement, des méthodes quantitatives de résonance magnétique nucléaire (RMN) offrent des biomarqueurs qui permettent la réalisation d’études longitudinales pour le suivi de l’évolution des maladies neuromusculaires et des essais thérapeutiques de manière non-invasive. A la différence de la dégénérescence graisseuse, les processus d’inflammation/œdème/nécrose et fibrose sont des signes d’activité des maladies et leurs quantifications constitueraient ainsi de biomarqueurs parfaitement adaptés pour le suivi thérapeutique. Ce travail de thèse a consisté à mettre en place des méthodologies quantitatives plus précises et adaptées à l’étude clinique du muscle pour : (i) détecter et quantifier des sites d’activité de maladies par la cartographie T2 de l’eau ; (ii) identifier les différents processus pathophysiologiques qui sont à l’origine des altérations du T2 ; et (iii) détecter et quantifier la fibrose musculaire. Nous avons implémenté deux méthodes pour la quantification du T2 de l’eau dans le muscle. La première est basée sur une séquence d’écho de spin du type CPMG, où les signaux provenant des protons des lipides et de l’eau sont acquis simultanément et séparés à postériori par un traitement tri-exponentiel qui exploite la différence entre les T2 qui caractérisent les signaux de l’eau et de la graisse. La deuxième technique est basée sur une séquence de « partially spoiled steady state free precession (pSSFP) ». Différemment de la première technique qui nécessite un traitement assez élaboré sur des images acquises à 17 temps d’écho différents, dans la pSSFP la cartographie T2 est extraite à partir de deux séries de données 3D. L’acquisition 3D est compatible avec des techniques de sélection spectrale de l’eau, ce qui évite la contamination par les signaux des lipides. Les deux méthodes ont été validées expérimentalement chez des malades et des sujets sains et ont démontré leur capacité à détecter et quantifier des sites d’activité de maladies. Ces deux travaux font l’objet de deux publications dans des journaux scientifiques internationaux : Azzabou, de Sousa, Araujo, & Carlier, 2014. Journal of Magnetic Resonance Imaging. DOI 10.1002/jmri.24613 (in press); et de Sousa, Vignaud, Araujo, & Carlier . 2012. Magnetic Resonance in Medicine. 67:1379-1390. Malgré le fait de permettre la détection des sites d’activité de maladies, la mesure mono-exponentielle du T2 de l’eau par imagerie reste non-spécifique vis-à-vis des processus physiologiques à l’origine de l’augmentation du T2. Il est connu que la relaxation T2 du muscle squelettique n’est pas mono-exponentielle. Cela est interprété comme une conséquence de la compartimentation anatomique de l’eau tissulaire. Nous avons mis au point une méthode pour l’acquisition localisée de données CPMG. Cette technique permet l’acquisition des données dans des conditions nécessaires pour la réalisation de traitements multi-exponentiels précis. Ce travail nous a permis d’établir un modèle de compartimentation qui explique parfaitement la relaxation T2 dans le muscle. Il a fait l’objet d’un article publié dans le « Biophysical Journal » (Araujo, Fromes & Carlier 2014. New Insights on skeletal muscle tissue compartments revealed by T2 NMR relaxometry. (In press)). Les essais réalisés chez des sujets malades suggèrent un grand potentiel pour l’application de la méthode dans des études cliniques. La formation de la fibrose commence avec une accumulation excessive de tissu conjonctif intramusculaire (TCIM). Nous avons exploité la technique « Ultrashort Time-to-Echo » (UTE) pour essayer de détecter et caractériser le signal du TCIM. Dans une première étude, nous avons caractérisé in vivo une composante à T2 court (~500 µs) dans le muscle, et nous avons trouvé des indices qui suggèrent qu’elle représente le TCIM. Dans une deuxième étude, nous avons mis au point une méthodologie qui a permis d’imager cette composante à T2 court dans le muscle pour la première fois
Current quantitative nuclear magnetic resonance (NMR) technics offer biomarkers that allow performing non-invasive longitudinal studies for the follow up of therapeutic trials in neuromuscular disorders (NMD). In contrast to fat degeneration, the mechanisms of inflammation/oedema/necrosis and fibrosis are characteristic signs of disease activity, which makes their quantification a promising source of crucial biomarkers for longitudinal studies. This thesis work consisted on the implementation of more precise quantitative NMR methods adapted to the clinical study of skeletal muscle (SKM) for : (i) detection and quantification of sites of disease activity by T2-mapping of muscle water ; (ii) investigation of the different pathophysiological mechanisms underlying T2 alterations ; and (iii) Detection and quantification of muscle fibrosis. We implemented two methods for T2 mapping of muscle water. The first one is based on a multi-spin-echo sequence du type CPMG. In this method the 1H-NMR signals from water and lipids are acquired simultaneously. The acquired data are fitted to a tri-exponential model, in which water and fat signals are separated by exploring the T2 difference between water and fat. This method allows extraction of muscle water T2-value in the presence of fat infiltration. The second method is based on a « partially spoiled steady state free precession » (pSSFP) sequence. In contrast to the first method, which demands a sophisticated post-treatment of images acquired at 17 different echo-times, with the pSSFP a T2-mapping is extracted from two 3D data sets. 3D acquisition is compatible with spectrally selective water excitation, which eliminates signal contribution from lipids. Both methods were validated experimentally on patients and healthy subjects. The results demonstrated their capacity to detect and quantify disease activity sites. This 2 works have been published in two international journals : Azzabou, de Sousa, Araujo, & Carlier, 2014. Journal of Magnetic Resonance Imaging. DOI 10.1002/jmri.24613 (in press); et de Sousa, Vignaud, Araujo, & Carlier . 2012. Magnetic Resonance in Medicine. 67:1379-1390. Although it was shown to reveal disease activity, mono-exponential T2 of muscle water is non-specific to what concerns the mechanisms underlying its alterations. It has been long known that T2 relaxation in SKM tissue is multi-exponential. This is currently accepted to reveal anatomical compartmentation of myowater. We implemented a method for localized spectroscopic CPMG acquisition. CPMG data respect echo-time sampling and signal to noise ration limits for allowing robust multiexponential analysis. This work allowed us to establish a compartmentation model that perfectly explains the multi-exponential T2 relaxation observed in SKM tissue. This work was published in the « Biophysical Journal » (Araujo, Fromes & Carlier 2014. New Insights on skeletal muscle tissue compartments revealed by T2 NMR relaxometry. (In press)). Pilot studies performed in patients show promising results and suggest potential application of the method in clinical studies. Fibrosis starts with an excessive accumulation of intramuscular connective tissue (IMCT). We have explored the « Ultrashort time to echo » (UTE) method with the aim to detect and characterize the signal from IMCT. In a first study we characterized in vivo a short T2 component (~500 µs) in SKM, and we collected evidences suggesting that this component might reflect IMCT. Then we implemented a methodology that allowed imaging this short component in SKM tissue for the first time
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Book chapters on the topic "Ultra-short echo time (UTE)"

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Li, Xue, Cheng Zhao, and Weiwei Zhang. "Non-invasive Assessment of in Vivo Auricular Cartilage by Ultra-short Echo Time (UTE) $$T_{2}^{*}$$ Mapping." In Lecture Notes in Computer Science, 92–100. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-32254-0_11.

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Rasche, Volker, Christian Hofmann, Regina Maschka, Johannes Ulrici, Erich Hell, Bernd Haller, and Saïd Boujraf. "The application of ultra short echo time MRI (UTE) for the structural assessment of dental hard tissue components." In IFMBE Proceedings, 65–67. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-03891-4_18.

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Ling, H., J. Moore, H. Kim, L. C. Trintinalia, R. Bhalla, and G. Xu. "Time-Frequency Processing of Wideband Radar Echo: from Fixed Resolution to Multiresolution and Superresolution." In Ultra-Wideband, Short-Pulse Electromagnetics 2, 527–34. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4899-1394-4_55.

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Witschey, Walter RT, and Michael Markl. "Blood flow and phase contrast CMR." In The EACVI Textbook of Cardiovascular Magnetic Resonance, edited by Massimo Lombardi, Sven Plein, Steffen Petersen, Chiara Bucciarelli-Ducci, Emanuela R. Valsangiacomo Buechel, Cristina Basso, and Victor Ferrari, 146–63. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198779735.003.0018.

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Flow-sensitive cardiovascular magnetic resonance (CMR) is a widespread non-invasive imaging method for the clinical evaluation of blood flow in cardiovascular disease. The basic principle of phase contrast magnetic resonance imaging (MRI) is the use of bipolar gradients to encode blood velocity in the magnetic resonance (MR) signal phase. The most common type of flow-encoded scan two-dimensional (2D) cine phase contrast CMR with single-direction velocity encoding is clinically used to quantify cardiovascular flow and velocities. Trade-offs between resolution (temporal and spatial) and acquisition time are illustrated in the context of patient examination, considering high-velocity jet flow, patient breath-hold duration, respiratory motion artefacts, and patient comfort. In addition, the chapter describes how the velocity-to-noise ratio and aliasing behaviour of flow measurements are affected by the velocity-encoding sensitivity (VENC). An advantage of phase contrast MR is that flow encoding may be performed in all three spatial dimensions, improving peak velocity measurement accuracy. Several clinical applications (aortic stenosis, coarctation, and ventricular shunting) and best practices are explained in detail with illustrations. Analysis and post-processing of phase contrast data are summarized. The progressive development of advanced phase contrast techniques is discussed by adding incremental complexity, starting with 2D phase contrast (2D spatial and one-dimensional velocity) and ending with four-dimensional flow encoding (three-dimensional spatial and velocity). Methods to accelerate phase contrast, such as parallel imaging, are briefly discussed. Finally, the chapter concludes with a summary of emerging topics for accelerated scanning and special applications such as compressed sensing, real-time phase contrast, and ultra-short echo time imaging.
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Ramzy, Danny, and Joshua Chung. "The Tandem: Life System." In Mechanical Circulatory Support, 138–44. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780190909291.003.0019.

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The Tandem Life series of support devices offers short-term mechanical circulatory support for patients with cardiopulmonary failure. The system provides options for left ventricular, right ventricular support, or both, as well as adaptation of a membrane oxygenator for extra corporeal membrane oxygenation (ECMO). This chapter outlines the indications for use, insertion techniques, and outcomes for the Tandem Heart, Tandem Lung, and Protek Duo platforms. Although limited published data exist for these technologies, experience is rapidly growing. The technology has allowed for patients to be fully ambulatory during time of support. The authors provide the perspective of one of the largest implanting centers internationally.
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Robert, Alice Rinky, Ganja Himavathi, and Maddila Suresh. "Multicomponent Synthesis of Heterocycles by Microwave Irradiation." In Advances in Organic Synthesis, 1–52. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815040524122170003.

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The multicomponent reactions (MCRs) are vital for producing structurally varied molecular objects. Multicomponent reactions (MCRs) contain three or more synthetic stages and are carried out without isolation of any intermediate, thus requiring mild reaction conditions. They are eco-friendly and cost-effective, have a short reaction time, produce higher yields, and require raw materials. The use of microwave irradiation in green organic synthesis sustains some of the aims of “green and sustainable chemistry.” It offers several benefits over the conventional approach in reducing time, reaction rates, selectivity, product yields, etc. Consequently, the preparation of various heterocycles using a one-pot multicomponent method combined with the application of microwave irradiation is one of the best areas amongst synthetic chemistry. The present study illustrates an overview of recent progress on microwave irradiated, one-pot multicomponent synthesis of heterocycles.
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"Benthic Habitats and the Effects of Fishing." In Benthic Habitats and the Effects of Fishing, edited by Jake Rice. American Fisheries Society, 2005. http://dx.doi.org/10.47886/9781888569605.ch4.

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<strong><em>Abstract. </em></strong>This paper first considers why it has been so difficult to make progress on moving fisheries toward ecological sustainability even in the narrow context of the target species. It then reviews the additional challenges that must be confronted when addressing the ecosystem effects of fishing, particularly impacts on benthic communities and habitats. Several impediments to progress are identified, including excess fishing capacity, the differential time courses of costs and benefits in reductions in fishing, myths and preconceptions regarding precaution and the relationship of sustainability to fishery characteristics, and above all, the complexity of the concept of sustainability itself, which has ecological, economic, and social dimensions. It has proven nearly impossible to find management options that do not lose ground on some dimensions in exchange for positive change on others. The paper evaluates the main tools available for reducing the effects of fishing on benthic communities and habitats, with regard to sustainability on all three axes. Four main classes of tools, including changing the cost– benefit accounting to include ecosystem goods and services, marine protected areas, gear modification and fleet substitution, and eco-certification, were all found to incur significant social or economic costs in order to make significant contributions to reducing impacts of fisheries on benthos. Because of the inescapability of trade-offs in decision making, a structured framework is needed for the decisionmaking process. Objectives-based fisheries management provides such a framework, but including benthos (and other ecosystem properties) in the list of objectives presents real challenges in keeping the list tractably short and the individual objectives usefully explicit. Work done by expert groups on approaches to meet these challenges is summarized. Overall, although there are many ecological questions about fishing effects on the benthos that have not yet been fully answered, the more urgent challenges are to find ways to use the knowledge we do have more effectively in decision making.
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Conference papers on the topic "Ultra-short echo time (UTE)"

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Li, Xue, Enhui Li, and Weiwei Zhang. "Quantifying Auricular Cartilage in Vivo Using Ultra-Short Echo Time (UTE) T2* Mapping." In the Third International Symposium. New York, New York, USA: ACM Press, 2019. http://dx.doi.org/10.1145/3364836.3364864.

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Ibrahim, El-Sayed H., Robert A. Pooley, Mellena D. Bridges, Joseph G. Cernigliaro, and William E. Haley. "Kidney stone imaging with 3D ultra-short echo time (UTE) magnetic resonance imaging. A phantom study." In 2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE, 2014. http://dx.doi.org/10.1109/embc.2014.6944094.

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Yang, Xiahan, Yahong Rosa Zheng, Ming Yang, and Lixin Ma. "Compressed sensing with non-uniform fast fourier transform for radial Ultra-short Echo Time (UTE) MRI." In 2015 IEEE 12th International Symposium on Biomedical Imaging (ISBI). IEEE, 2015. http://dx.doi.org/10.1109/isbi.2015.7164020.

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Buerger, Christian, Andrew Aitken, Charalampos Tsoumpas, Andrew Peter King, Volkmar Schulz, Paul Marsden, and Tobias Schaeffter. "Investigation of 4D PET attenuation correction using Ultra-short Echo Time MR." In 2011 IEEE Nuclear Science Symposium and Medical Imaging Conference (2011 NSS/MIC). IEEE, 2011. http://dx.doi.org/10.1109/nssmic.2011.6153668.

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Ibrahim, El-Sayed, Robert Pooley, Joseph Cernigliaro, Mellena Bridges, Jamie Giesbrandt, James Williams, and William Haley. "In vitro imaging of kidney stones using ultra-short echo-time magnetic resonance." In 2015 IEEE 12th International Symposium on Biomedical Imaging (ISBI 2015). IEEE, 2015. http://dx.doi.org/10.1109/isbi.2015.7164153.

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Bates, A., N. Higano, A. Schuh, A. Hahn, S. B. Fain, P. S. Kingma, and J. C. Woods. "Lung Ventilation Maps in Neonates with Congenital Diaphragmatic Hernia from Registration of Ultra-Short Echo Time Magnetic Resonance Imaging." In American Thoracic Society 2020 International Conference, May 15-20, 2020 - Philadelphia, PA. American Thoracic Society, 2020. http://dx.doi.org/10.1164/ajrccm-conference.2020.201.1_meetingabstracts.a4685.

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Magariu, Nicolae, Nicolai Ababii, Vasile Postica, Mani Teja Boddulur, Oleg Lupan, Rainer Adelung, and Sandra Hansen. "Al2O3/CuO non-planar heterostructures for VOCs vapors detection." In 11th International Conference on Electronics, Communications and Computing. Technical University of Moldova, 2022. http://dx.doi.org/10.52326/ic-ecco.2021/el.03.

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In this work, the gas sensing properties of the non-planar heterostructures based on CuO thin films, grown by the direct ink writing and covered with an ultrathin Al2O3 layer, are presented as a function of the operating temperature. The obtained results demonstrates the excellent selectivity to volatile organic compounds (VOCs) vapors, namely n-butanol and 2-propanol in a operating temperature range of 200 – 350 ºC. The relatively low gas response was observed at room temperature, which is very important for low-power operation. The dynamic gas response showed an ultra-fast response time of 2 – 3 s. The obtained results demonstrates the excellent potential of nonplanar heterostructures based on metal oxides for use in high-performance environmental monitoring applications.
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Da Silva de Aguiar, Janaina Izabel, Amir Mahmoudkhani, and Samal Ibragimova. "Ultra-Low Dose Asphaltene Inhibitors for Offshore Applications: Myth or Reality." In SPE International Conference on Oilfield Chemistry. SPE, 2021. http://dx.doi.org/10.2118/204357-ms.

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Abstract In recent years, long-distance subsea tiebacks have become a preferred field development option for deep and ultra-deepwater production. However, conditions such as lengthy umbilical systems, high pressures and variable temperatures conditions pose challenges for the continuous injection of various flow assurance chemicals. Severe operating conditions often require relatively high volumes of diluted inhibitors to be stored and injected offshore, resulting in high CAPEX costs for the installation of large topsides chemical storage tanks and their associated weight increases. Alliance Engineering estimates a deepwater platform's topsides installed costs are within the range of $35,000-$50,000/ton. It is possible to achieve significant capital cost savings on new platform designs if the dosage rates and subsequently offshore storage volumes of the highest usage production chemicals such as asphaltene inhibitors could be significantly reduced. This paper presents information on a new class of biosurfactants that are bio-based and eco-acceptable with potentials for development of ultra-low dose asphaltene inhibitors for offshore applications. Asphaltenes were extracted from chemical free crude oil samples and a curve of solubility with different ratios of heptane was obtained for each sample in order to determine the best conditions to perform the screening tests. A new class of glycolipid biosurfactants (GLP-U) was developed as an asphaltene dispersants effective at low concentrations for use in offshore applications. The new GLP-U biosurfactants are eco-acceptable and soluble in the organic solvents commonly used in offshore production chemicals. GLP-U were proved to be effective in dispersing and preventing precipitation of isolated asphaltenes at dosage rates as low as 25 mg/L (active substance), while for comparison a dodecylbenzesulfonic acid-based inhibitor provided inhibition at significantly higher concentrations (at least 40 times more).
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"Learning Entrepreneurship through Virtual Multicultural Teamwork." In InSITE 2019: Informing Science + IT Education Conferences: Jerusalem. Informing Science Institute, 2019. http://dx.doi.org/10.28945/4364.

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[This Proceedings paper was revised and published in the 2019 issue of the journal Issues in Informing Science and Information Technology, Volume 16] Aim/Purpose: This paper explores the benefits and challenges of experiencing virtual multi-cultural teamwork in order to learn entrepreneurship. Background: Entrepreneurial eco-system usually requires working in international, virtual multi-cultural diverse teams. Higher education institutes are trying to educate future generation of entrepreneurs, coping with challenges derived from the virtual work and cultural diversity. Prior research shows that traditional learning is not effective for entrepreneurial education. Methodology: An explorative study was conducted based on the BIPA project, a Bavarian (German)-Israeli Partnership Accelerator, which was held four times between 2015 and 2017. The project aims to experience entrepreneurial virtual multicultural teamwork via co-creation of tailored-solutions for challenges of German or Israeli corporates. Retrospective interviews with participants were held after finishing their mission, and analyzed. Contribution: This research contributes to the body of knowledge about multicultural diverse participants in virtual entrepreneurial environments, in order to work together. This situation raises new challenges, due to the combination of multicultural teamwork and the use of virtual communication. Findings: The multicultural teamwork was a trigger to participate, specifically in the con-text of entrepreneurship studies with those two cultures, German and Israeli, which were found by participants as complementary, stimulating and fruitful, although challenging. Through experience, participants improved their entrepreneurial skills and mindset. The major teamwork challenges that were found included conflicts concerning free-riding, as well as communication challenges, due to virtual, language and cultural communication competencies. Recommendations for Practitioners: At a practical level, results can be useful for global companies, showing the benefits of virtual teamwork of employees in different locations, both in terms of reducing expenses and improving innovation. Moreover, managers can motivate employees by highlighting personal benefits, such as cultural awareness and improving their entrepreneurial skills and mindset. In addition, faculty may use this kind of experience to enhance entrepreneurial learning skills and mindset. Recommendations for Researchers : At the theoretical level, this research advances the body of knowledge of entrepreneurial multicultural teamwork in a virtual environment. In this research, the teams worked for a short time together (14 weeks) and had a week of face-to-face interaction with their team members. It is recommended to examine long-term teamwork, and how it affects teamwork challenges, as well as entrepreneurial learning. This research found the combination of German-Israeli cultures as stimulating entrepreneurial teamwork. It is recommended to examine other cultural combinations in teams, in order to be able to generalize findings. Impact on Society: Understanding the needs, benefits, and challenges of entrepreneurial multicultural teams working in a virtual environment can be useful to current global entrepreneurial eco-system, which is commonly using this kind of teamwork. Future Research: ‎This study included teams from two cultures: German and Israeli. Research must be expanded to different cultures and to groups compounded from more than two cultures. Moreover, the combination of virtual communication and face-to-face meetings in different milestones during the timeline of the teamwork must be further examined, especially in longer projects.
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