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Статті в журналах з теми "Techniques IRM":
1
Boyer, Bruno, and Carl El Khoury. "IRM mammaire : techniques d’examen." Journal de Radiologie 87, no. 10 (October 2006): 1197. http://dx.doi.org/10.1016/s0221-0363(06)86703-x.
2
Prat, X., and P. Taourel. "3121 IRM du sein : techniques, indications." Journal de Radiologie 86, no. 10 (October 2005): 1202. http://dx.doi.org/10.1016/s0221-0363(05)74988-x.
3
La Folie, T., F. Sbardella, J. B. Veyrieres, A. Rimbot, and C. Arteaga. "IRM corps entier : techniques et indications." EMC - Radiologie et imagerie médicale - Abdominale - Digestive 5, no. 3 (January 2010): 1–15. http://dx.doi.org/10.1016/s1879-8527(10)72852-5.
4
Varin, C., C. Virlouvet, and J. N. Dacher. "TMA3 Techniques de synchronisation en IRM cardiaque." Journal de Radiologie 85, no. 9 (September 2004): 1513. http://dx.doi.org/10.1016/s0221-0363(04)77689-1.
5
Felblinger, Jacques, and Dominique Sappey-Marinier. "Méthodologies et techniques logicielles en IRM cérébrale." Journal de Radiologie 89, no. 10 (October 2008): 1258. http://dx.doi.org/10.1016/s0221-0363(08)75748-2.
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Thomassin-Naggara, I., I. Trop, L. Lalonde, J. David, L. Péloquin, and J. Chopier. "Astuces et nouveautés techniques en IRM mammaire." Journal de Radiologie Diagnostique et Interventionnelle 93, no. 11 (November 2012): 876–89. http://dx.doi.org/10.1016/j.jradio.2011.05.025.
7
Pierot, Laurent, and Serge Bracard. "IRM 3 Tesla : aspects techniques et applications cliniques." Journal de Radiologie 86, no. 10 (October 2005): 1278. http://dx.doi.org/10.1016/s0221-0363(05)75277-x.
8
Blum, Alain. "Nouvelles techniques, nouvelles pratiques en IRM ostéo-articulaire." Journal de Radiologie 89, no. 10 (October 2008): 1291. http://dx.doi.org/10.1016/s0221-0363(08)75852-9.
9
Blum, Alain. "Nouvelles techniques, nouvelles pratiques en IRM ostéo-articulaire." Journal de Radiologie 89, no. 10 (October 2008): 1320. http://dx.doi.org/10.1016/s0221-0363(08)75961-4.
10
Dupont, Sophie. "Qu’attend le neurologue des techniques avancées en IRM ?" Journal of Neuroradiology 43, no. 2 (March 2016): 75–76. http://dx.doi.org/10.1016/j.neurad.2016.01.036.
Дисертації з теми "Techniques IRM":
1
Bonnet, Mathieu. "Angio-IRM des artères pulmonaires : choix techniques et optimisation." Bordeaux 2, 1994. http://www.theses.fr/1994BOR23048.
2
Thomassin-Naggara, Isabelle. "Etude des tumeurs annexielles du pelvis féminin en IRM fonctionnelle : mise au point des techniques et applications cliniques." Paris 11, 2008. http://www.theses.fr/2008PA112116.
Анотація:
La caractérisation préopératoire des tumeurs annexielles est déterminante pour la prise en charge chirurgicale. L’IRM fonctionnelle dynamique avec injection (DCE-MRI) permet une optimisation de la caractérisation des tissus. Les tumeurs annexielles se distinguent selon leur courbe dynamique de rehaussement qui reflètent l’immaturité de la paroi vasculaire et l’expression du VEGFR-2 sur les cellules endothéliales. En vue d’une analyse quantitative du rehaussement, il est souhaitable de réaliser une séquence turbo-FLASH avec des angles élevés pour obtenir une dynamique de rehaussement optimale associée à une quasi linéarité de la relation entre le signal et la concentration de gadolinium. L’initialisation par un modèle de Kéty étendu stabilise la modélisation compartimentale à 4 paramètres qui permet la description la plus complète des échanges entre les compartiments vasculaire et interstitiel. L’optimisation de l ’acquisition et du post traitement des datas ont permis la réalisation d ’une analyse quantitative de la prise de contraste, analyse reproductible et pertinente pour comprendre les phénomènes physiopathologiques au sein des tissus. Dans le domaine des tumeurs annexielles, la perfusion tissulaire et la fraction volumique sanguine sont plus élevées dans les tumeurs malignes que dans les tumeurs bénignes. Enfin, l ’analyse quqntitative du rehaussement a permis la mise en évidence de données pertinentes sur la perfusion du myométre et tout particulièrement du myomètre interne qui pourrait avoir une rôle majeur dans l ’avenir dans le cadre des programmes de procréation médicalement assistéeThe preoperative characterization of adnexal tumors is crucial for surgical care. Dynamic contrast enhanced MR imaging (DCE-MRI) allows an optimization of the tissue characterization. Adnexal tumors differ according to their dynamic curve enhancement, which reflect the immaturity of the vascular wall and the expression of VEGFR-2 on endothelial cells. For a quantitative analysis of enhancement, a turbo-FLASH sequence with high angles is better to get both optimal dynamic enhancement range and an almost linear relationship between the signal and the concentration of gadolinium. Initialization by a extended Kéty model stabilizes our two-compartmental model which allows the best description of exchanges between the capillary and the interstitial spaces. Using quantitative DCE MRI, malignant adnexal tumors display higher tissue perfusion and blood volume fraction than benign tumors. Finally, quantitative DCE-MRI is a suitable, non-invasive tool to assess physiological microvascular states and variations in normal myometrium, and could potentially be used to assess the role of the inner myometrium in assisted reproductive therapy
3
Dhouib, Dorra. "Stratégie de compression d'images IRM volumiques pour des communications sans fil." Poitiers, 2010. http://www.theses.fr/2010POIT2251.
Анотація:
Face à l'augmentation importante des données en imagerie médicale générées par différents types de modalités, une réduction de la taille des données par compression des images s'est avérée indispensable. Cette dernière permet en effet de minimiser l'espace de stockage ou d'archivage des données et de réduire le temps de transfert des données et la largeur de bande dans le cas du traitement à distance (télémédecine). Dans ces applications, la compression doit évidemment préserver l'information utile. Ceci est possible grâce à la redondance de l'information qui peut être spatiale ou fréquentielle. Dans ce contexte, il est à noter que différentes techniques de compression efficaces ont été développées au cours des dernières décennies. Cependant, de nos jours, dans les services radiologiques, seule la compression sans perte est la plus souvent adoptée. Malgré les améliorations et les efforts fournis par les méthodes de compression sans perte, une compression avec perte s'est montrée envisageable. Mais ce type de compression doit être effectué sous le contrôle d'un médecin compétent, et sans avoir à introduire une certaine distorsion ; ce qui pourrait causer une éventuelle perte de l'information clinique utile et par conséquent influencer de manière significative le diagnostic. De plus, lors de la transmission, le bruit canal peut aussi introduire des erreurs qui risquent d'erroner le diagnostic. C’est pour cette raison qu'il est important de développer une stratégie de compression adéquate afin de réduire ce volume de données, et de résister aux erreurs de transmission par la même occasion. Pour répondre à cette double contrainte une stratégie de codage basée ROI et protection inégale de flux est développée dans cette thèse. Le schéma de compression basé ROI et protection inégale de flux proposé se compose de trois étapes. Dans une première étape, nous proposons d'extraire la région d'intérêt par segmentation hiérarchique de ces régions selon une méthode de segmentation basée sur la technique de lignes de partage des eaux par marqueurs, combinée à la technique des contours actifs par ensembles de niveaux. Dans la deuxième étape, les régions résultantes sont par la suite codées de façon sélective par un codeur 3D basé transformée en ondelettes discrète adaptatif de forme BISK3D, où le taux de compression de chaque région dépend de l'importance de cette région et de son utilité dans le diagnostic. En effet la région d'intérêt qui contient l'information utile au diagnostic est codée avec du "presque sans pertes" et le reste du volume avec perte. La troisième étape de notre schéma de codage est une stratégie de protection inégale (UEP) qui consiste à protéger le ROI avec un code correcteur de type Reed-Solomon avec un rendement très bas de façon à assurer une robustesse aux erreurs et les autres régions avec le même type de code correcteur mais de rendement plus élevé suivant la région. Des tests d’évaluation sont enfin réalisés afin de visualiser l’impact des erreurs de compression et par la suite celui des erreurs canal sur les différents flux. Afin d'étudier les performances de notre stratégie de codage dans le cas d'une transmission canal de type gaussien, une comparaison de cette stratégie avec SPIHT 3D est effectuéeGiven the significant increase in medical imaging data generated by different types of procedures, reducing the size of the data compression of images has become indispensable. It can minimize the data space in the case of archiving (or storage) or in the case of treatment at a distance (telemedicine) in the latter case, to reduce transfer time and bandwidth. In these applications, compression is obviously preserve useful information. This is possible thanks to the redundancy of information which can be either spatial or frequency. In this context, different effective compression techniques have been developed in recent decades. However, currently, in the radiological services, only lossless compression is the preferred way. Despite the improvements and efforts made by the methods of lossless compression, lossy compression has become feasible. But this type of compression must be done under the supervision of a competent physician, and without having to introduce some distortion, which could cause a possible loss of useful clinical information and therefore significantly influence the diagnosis. Also during transmission, the channel noise may also introduce errors that are likely erroneous diagnosis. For this reason it is important to develop a strategy appropriate to compression, both to reduce the volume of data, and to resist transmission errors. To meet this dual requirement of a strategy based ROI coding and unequal protection of streams is developed in this thesis. The compression scheme based ROI and unequal protection of stream proposed consists of three stages. In a first step we propose to extract the region of interest by hierarchical segmentation of these regions using a segmentation method based on the technical guidelines of the watershed by markers, combined with the technique of active contours by level sets. The resulting regions are then selectively encoded by an encoder 3D wavelet transform based adaptive discrete form BISK3D, where the compression ratio of each region depends on the importance of this region and its usefulness in diagnosis. Indeed the region of interest which contains information useful in diagnosis is coded with "almost lossless" and the rest of the volume lost. The third step of our coding scheme is a strategy of unequal protection (UEP), which is to protect the region of interest with a Reed-Solomon error correcting code with a very high efficiency so as to provide robustness to errors and other regions with the same type of correction code but lower yield by region. Evaluation tests were finally carried out to see the impact of compression errors and then the impact of channel errors on the various streams. To study the performance of our coding strategy in the case of a Gaussian transmission channel, this strategy is compared with 3D SPIHT
4
Bakhous, Christine. "Modèles d'encodage parcimonieux de l'activité cérébrale mesurée par IRM fonctionnelle." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00933426.
Анотація:
L'imagerie par résonance magnétique fonctionnelle (IRMf) est une technique non invasive permettant l'étude de l'activité cérébrale au travers des changements hémodynamiques associés. Récemment, une technique de détection-estimation conjointe (DEC) a été développée permettant d'alterner (1) la détection de l'activité cérébrale induite par une stimulation ainsi que (2) l'estimation de la fonction de réponse hémodynamique caractérisant la dynamique vasculaire; deux problèmes qui sont généralement traités indépendamment. Cette approche considère une parcellisation a priori du cerveau en zones fonctionnellement homogènes et alterne (1) et (2) sur chacune d'entre elles séparément. De manière standard, l'analyse DEC suppose que le cerveau entier peut être activé par tous les types de stimuli (visuel, auditif, etc.). Cependant la spécialisation fonctionnelle des régions cérébrales montre que l'activité d'une région n'est due qu'à certains types de stimuli. La prise en compte de stimuli non pertinents dans l'analyse, peut dégrader les résultats. La sous-famille des types de stimuli pertinents n'étant pas la même à travers le cerveau une procédure de sélection de modèles serait très coûteuse en temps de calcul. De plus, une telle sélection a priori n'est pas toujours possible surtout dans les cas pathologiques. Ce travail de thèse propose une extension de l'approche DEC permettant la sélection automatique des conditions (types de stimuli) pertinentes selon l'activité cérébrale qu'elles suscitent, cela simultanément à l'analyse et adaptativement à travers les régions cérébrales. Des exemples d'analyses sur des jeux de données simulés et réels, illustrent la capacité de l'approche DEC parcimonieuse proposée à sélectionner les conditions pertinentes ainsi que son intérêt par rapport à l'approche DEC standard.
5
Habib, Dayane. "Diffusion de l'hélium-3 hyperpolarisé dans le tissu pulmonaire : évaluation par différentes techniques IRM." Phd thesis, Université Paris Sud - Paris XI, 2007. http://tel.archives-ouvertes.fr/tel-00435916.
Анотація:
Ce travail présente une étude expérimentale sur l'effet de la diffusion restreinte de l'hélium-3 hyperpolarisé dans l'acinus pulmonaire effectuée à bas champ magnétique 0,1 T. Plusieurs fantômes avec différentes tailles et connections modélisant l'acinus humain sain et à un stade précoce de l'emphysème ont été réalisés selon le modèle de Kitaoka. L'atténuation du signal dévie par rapport au comportement prévu de décroissance exponentielle en G2, G étant l'intensité de gradient. Cette observation indique une certaine ambiguïté sur la possibilité de quantifier de façon absolue le coefficient de diffusion apparent (ADC), sauf dans la limite G faible. Des simulations Monte-Carlo sont en bon accord avec les mesures. Des séquences originales rapides basées sur le principe des échos de spin multiples ont été développées, pour accéder à une valeur globale d'ADC à des temps longs permettant l'exploration du gaz dans toute la structure de branchement de l'acinus. Des mesures sur un modèle animal d'emphysème (rat) ont été comparées à des cartes obtenues à partir d'acquisitions standard avec petits angles de basculement, elles indiquent une augmentation systématique et toujours significative des ADC par rapport au contrôle sain, pour plusieurs protocoles de mesure. La méthode globale a une meilleure sensibilité que la cartographie standard, en outre elle donne un plus fort contraste d'ADC entre animaux sains et avec emphysème du fait de la possibilité d'employer des valeurs de G plus faibles. Ces outils de mesure de diffusion par IRM et RMN des gaz hyperpolarisés ouvrent des voies prometteuses aussi bien pour la physique de la diffusion que pour les applications médicales.
6
Mellerio, Charles. "Optimisation des techniques avancées en IRM cérébrale dans la détection des lésions développementales épileptogènes." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05T025/document.
Анотація:
Les dysplasies corticales focales de type 2 (DCF2) sont une cause fréquente d’épilepsie partielle pharmacorésistante pouvant bénéficier d’un traitement chirurgical. Leur détection en IRM est un facteur indépendant de bon pronostic. Leur diagnostic reste difficile avec jusqu’à 40% d’IRM négatives. Le travail de cette thèse a pour principal objectif d’améliorer la détection des DCF2 à partir des séquences conventionnelles, d’évaluer la pertinence d’une augmentation de champ magnétique, et de valider de nouveaux outils de détection, en particulier par l’identification d’anomalies des sillons associées aux DCF2 de manière automatique puis visuelles. Cette étude a été réalisée à partir d’une des plus importante cohorte de patients (>80 patients) porteurs de DCF2 prouvée histologiquement. L’évaluation de la fréquence de chacun des signes en IRM nous a permis de démontrer que, bien qu’aucune anomalie ne soit visible dans 41% des cas, les différents signes chez les patients avec une IRM positive n’étaient jamais isolés et que la combinaison des 3 signes les plus évocateurs de DCF2 (épaississement cortical, flou de l'interface blanc-gris et « transmantle sign »), était retrouvée chez 27 patients (64%) suggérant que l’IRM puisse être un examen très caractéristique. En augmentant le champ magnétique de 1,5 à 3T en IRM le taux de détection n’est que peu modifié mais la caractérisation des DCF2 est améliorée en raison d’une meilleure visualisation du « transmantle sign », considéré comme une signature en IRM des DCF2. L’analyse automatisée des sillons basés sur le calcul d’un nouveau paramètre appelé « énergie sulcale » permet d’identifier des motifs sulcaux anormaux chez les patients porteurs de DCF2 dans la région centrale en comparaison aux sujets sains. Ce résultat souligne l'importance d’une étude des sillons et pourrait fournir un critère supplémentaire pour détecter et localiser la lésion chez des patients à IRM négative. Enfin, l’analyse visuelle des sillons par un reformatage 3D du cortex nous a permis de décrire un nouveau marqueur des DCF2 de la région centrale : un motif sulcal dénommé le "Power Button Sign". Compte tenu de son excellente reproductibilité et de sa spécificité, il pourrait être utilisé comme un nouveau critère diagnostic majeur de DCF2 de la région centrale. L’ensemble de ces résultat participe à la meilleure compréhension des phénomènes développementaux impliqués dans la physiopathologie des DCF2 et offre de nombreuses perspectives pour l’amélioration de leur détection en imagerieFocal cortical dysplasia type 2 (FCD2) is a common cause of intractable partial epilepsy surgically treatable. Their detection by MRI is an independent factor of good prognosis. The MR imaging diagnosis remains difficult with up to 40% negative MRI. Our main objective is to improve the detection of FCD2from conventional sequences, to assess the relevance of increased magnetic field and validate new tools for detection, in particular by identifying sulcal abnormalities associated with FCD2 automatically and visually. This study was carried out from one of the largest cohort of patients (> 80 patients) with histologically proven FCD2. The evaluation of the frequency of each MR signs showed that, although no abnormality is seen in 41% of cases, the different signs in patients with a positive MRI were never isolated and the combination of the 3 most suggestive signs of FCD2 (cortical thickening, bluring of the gray-white matter interface and "transmantle sign") was found in 27 patients (64%), indicating that MRI can be very suggestive. By increasing the magnetic field from 1.5 to 3T MRI detection rate is only slightly changed but characterization of FCD2 is improved thanks to a better visualization of the " transmantle sign " considered as a MR signature of FCD2. The automated sulcus analysis based on the calculation of a new parameter called "sulcal energy" identifies abnormal sulcal patterns in patients with FCD2 in the central region in comparison to healthy subjects. This result underlines the importance of the identification of sulci and could provide an additional criterion for detecting and locating the lesion in patients with negative MRI. Finally, the visual analysis of sulci by 3D reformatting of the cortex allowed us to describe a new MR sign of FCD2 in the central region: a sulcal pattern called the "Power Button Sign". Given its excellent reproducibility and specificity, it could be used as a new major diagnostic criterion of FCD2 in the central region. All these results contribute to the better understanding of the developmental processes involved in the pathophysiology of FCD2 and offers many opportunities for improving their MR detection
7
Poujol, Julie. "Techniques d'acquisitions et reconstructions IRM rapides pour améliorer la détection du cancer du sein." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0143/document.
Анотація:
Le cancer du sein est aujourd’hui le cancer le plus fréquent chez la femme ainsi que la première cause de décès féminin par cancer. Actuellement, l’IRM mammaire n’est réalisée qu’en seconde intention lorsque les autres modalités d’imagerie ne suffisent pas à poser un diagnostic. Dans le cas des populations à risque, l’IRM mammaire est recommandée comme examen de dépistage annuel en raison de sa très haute sensibilité de détection. Par IRM, la détection d’un cancer du sein se fait à la suite de l’injection d’un produit de contraste qui permet de visualiser les lésions mammaires en hypersignal. La majeure partie du diagnostic repose sur l’analyse morphologique de ces lésions ; une acquisition hautement résolue spatialement est donc nécessaire. Malgré l’utilisation des techniques d’accélération courantes, le volume de données à acquérir reste important et la résolution temporelle de l’examen d’IRM mammaire est aujourd’hui aux alentours d’une minute. Cette faible résolution temporelle limite donc intrinsèquement la spécificité de l’examen d’IRM mammaire. Un examen avec une haute résolution temporelle permettrait l’utilisation de modèles pharmacocinétiques donnant accès à des paramètres physiologiques spécifiques des lésions. L’approche proposée dans ce travail de thèse est le développement d’une séquence IRM permettant à la fois la reconstruction classique d’images, telle que celle utilisée en routine clinique pour le diagnostic, ainsi qu’une reconstruction accélérée d’images avec une plus haute résolution temporelle permettant ainsi l’application de modèles pharmacocinétiques. Le développement de cette séquence a été réalisé en modifiant l’ordre d’acquisition du domaine de Fourier de la séquence utilisée en clinique, afin qu’il soit aléatoire et permette la reconstruction a posteriori de domaines sous-échantillonnés acquis plus rapidement. Des acquisitions sur des objets tests, sur des volontaires et sur des patientes ont montré que l’acquisition aléatoire ne modifiait pas les images obtenues par reconstruction classique permettant ainsi le diagnostic conventionnel. Une attention particulière a été portée pour permettre la suppression de graisse nécessaire à l’acquisition des images d’IRM mammaire. Les reconstructions des domaines sous-échantillonnés sont réalisées via des reconstructions Compressed Sensing permettant la suppression des artéfacts de sous-échantillonnage. Ces reconstructions Compressed Sensing ont été développées et testées sur des fantômes numériques reproduisant des IRMs mammaires. Le potentiel de cette nouvelle acquisition a enfin été testé sur une lésion artificielle mammaire, développée à cet effet, et reproduisant des prises de contraste mammairesBreast cancer is nowadays the first cause of female cancer and the first cause of female death by cancer. Breast MRI is only performed in second intention when other imaging modalities cannot lead to a confident diagnosis. In high risk women population, breast MRI is recommended as an annual screening tool because of its higher sensitivity to detect breast cancer. Breast MRI needs contrast agent injection to visualize enhancing lesions and the diagnosis is mostly based on morphological analysis of these lesions. Therefore, an acquisition with high spatial resolution is needed. Despite the use of conventional MRI acceleration techniques, the volume of data to be acquired remains quite large and the temporal resolution of the exam is around one minute. This low temporal resolution may be the cause of the low specificity of breast MRI exam. Breast MRI with higher temporal resolution will allow the use of pharmacokinetic models to access physiological parameters and lesion specifications. The main aim of this work is to develop a MRI sequence allowing a flexible use of the acquired data at the reconstruction stage. On the one hand, the images can be reconstructed with a conventional reconstruction like the protocol used in clinical routine. On the other hand, the new MRI sequence will also allow the reconstruction of images with a higher temporal resolution allowing the use of pharmacokinetic models. The development of this sequence was done by modifying the acquisition order in the Fourier domain. A random acquisition of the Fourier domain will allow the reconstruction of sub-sampled domains acquired faster. We paid attention to fat suppression efficiency with this new Fourier domain acquisition order. Tests were performed on phantom, female volunteers and patients. These tests showed that the random acquisition did not impact the quality of images (MRI signal and lesion morphology) obtained by conventional reconstruction thus allowing the conventional diagnosis. The reconstructions of the sub-sampled Fourier domains were made using Compressed Sensing reconstructions to remove sub-sampling artifacts. These reconstructions were developed and tested on digital phantoms reproducing breast MRI. The potential of this new MRI acquisition was tested on an artificial enhancing breast lesion developed especially for this purpose
8
Poujol, Julie. "Techniques d'acquisitions et reconstructions IRM rapides pour améliorer la détection du cancer du sein." Electronic Thesis or Diss., Université de Lorraine, 2017. http://www.theses.fr/2017LORR0143.
Анотація:
Le cancer du sein est aujourd’hui le cancer le plus fréquent chez la femme ainsi que la première cause de décès féminin par cancer. Actuellement, l’IRM mammaire n’est réalisée qu’en seconde intention lorsque les autres modalités d’imagerie ne suffisent pas à poser un diagnostic. Dans le cas des populations à risque, l’IRM mammaire est recommandée comme examen de dépistage annuel en raison de sa très haute sensibilité de détection. Par IRM, la détection d’un cancer du sein se fait à la suite de l’injection d’un produit de contraste qui permet de visualiser les lésions mammaires en hypersignal. La majeure partie du diagnostic repose sur l’analyse morphologique de ces lésions ; une acquisition hautement résolue spatialement est donc nécessaire. Malgré l’utilisation des techniques d’accélération courantes, le volume de données à acquérir reste important et la résolution temporelle de l’examen d’IRM mammaire est aujourd’hui aux alentours d’une minute. Cette faible résolution temporelle limite donc intrinsèquement la spécificité de l’examen d’IRM mammaire. Un examen avec une haute résolution temporelle permettrait l’utilisation de modèles pharmacocinétiques donnant accès à des paramètres physiologiques spécifiques des lésions. L’approche proposée dans ce travail de thèse est le développement d’une séquence IRM permettant à la fois la reconstruction classique d’images, telle que celle utilisée en routine clinique pour le diagnostic, ainsi qu’une reconstruction accélérée d’images avec une plus haute résolution temporelle permettant ainsi l’application de modèles pharmacocinétiques. Le développement de cette séquence a été réalisé en modifiant l’ordre d’acquisition du domaine de Fourier de la séquence utilisée en clinique, afin qu’il soit aléatoire et permette la reconstruction a posteriori de domaines sous-échantillonnés acquis plus rapidement. Des acquisitions sur des objets tests, sur des volontaires et sur des patientes ont montré que l’acquisition aléatoire ne modifiait pas les images obtenues par reconstruction classique permettant ainsi le diagnostic conventionnel. Une attention particulière a été portée pour permettre la suppression de graisse nécessaire à l’acquisition des images d’IRM mammaire. Les reconstructions des domaines sous-échantillonnés sont réalisées via des reconstructions Compressed Sensing permettant la suppression des artéfacts de sous-échantillonnage. Ces reconstructions Compressed Sensing ont été développées et testées sur des fantômes numériques reproduisant des IRMs mammaires. Le potentiel de cette nouvelle acquisition a enfin été testé sur une lésion artificielle mammaire, développée à cet effet, et reproduisant des prises de contraste mammairesBreast cancer is nowadays the first cause of female cancer and the first cause of female death by cancer. Breast MRI is only performed in second intention when other imaging modalities cannot lead to a confident diagnosis. In high risk women population, breast MRI is recommended as an annual screening tool because of its higher sensitivity to detect breast cancer. Breast MRI needs contrast agent injection to visualize enhancing lesions and the diagnosis is mostly based on morphological analysis of these lesions. Therefore, an acquisition with high spatial resolution is needed. Despite the use of conventional MRI acceleration techniques, the volume of data to be acquired remains quite large and the temporal resolution of the exam is around one minute. This low temporal resolution may be the cause of the low specificity of breast MRI exam. Breast MRI with higher temporal resolution will allow the use of pharmacokinetic models to access physiological parameters and lesion specifications. The main aim of this work is to develop a MRI sequence allowing a flexible use of the acquired data at the reconstruction stage. On the one hand, the images can be reconstructed with a conventional reconstruction like the protocol used in clinical routine. On the other hand, the new MRI sequence will also allow the reconstruction of images with a higher temporal resolution allowing the use of pharmacokinetic models. The development of this sequence was done by modifying the acquisition order in the Fourier domain. A random acquisition of the Fourier domain will allow the reconstruction of sub-sampled domains acquired faster. We paid attention to fat suppression efficiency with this new Fourier domain acquisition order. Tests were performed on phantom, female volunteers and patients. These tests showed that the random acquisition did not impact the quality of images (MRI signal and lesion morphology) obtained by conventional reconstruction thus allowing the conventional diagnosis. The reconstructions of the sub-sampled Fourier domains were made using Compressed Sensing reconstructions to remove sub-sampling artifacts. These reconstructions were developed and tested on digital phantoms reproducing breast MRI. The potential of this new MRI acquisition was tested on an artificial enhancing breast lesion developed especially for this purpose
9
Dou, Weibei. "Segmentation d'images multispectrales basée sur la fusion d'informations : application aux images IRM." Caen, 2006. http://www.theses.fr/2006CAEN2026.
Анотація:
L'objectif de cette thèse consiste à développer une architecture de fusion d'informations basée sur la théorie floue pour la segmentation d'une cible à partir de plusieurs sources d'images. Notre application principale porte sur la segmentation des images IRM multispectrales. Nous proposons une approche de segmentation automatique basée sur la fusion des caractéristiques extraites de chaque source d'image. Ces caractéristiques sont modélisées par des fonctions d'appartenance, obtenues à partir de fonctions analytiques, qui prennent en compte des connaissances à priori sur la possibilité d'appartenance à une cible (tumeur ou tissus cérébraux) donnée par l'expert, et aussi la gradation d'intensité du signal de la cible. La segmentation d'une cible consiste finalement à combiner les différents degrés d'appartenance de la cible. Une étape supplémentaire basée sur une croissance 3D des régions floues est proposée pour améliorer le résultat de la combinaison. Pour évaluer les résultats de segmentation représentés par un ensemble flou, une extension du coefficient Kappa de Cohen, nommée "Kappa flou" est proposée, qui est une méthode d'évaluation globale sur la proportion d'agrément d'un classement flou. Cette architecture développée est mise en oeuvre pour la segmentation des tumeurs cérébrales à partir des images IRM qui comprennent pour l'instant les séquences de base : T1, T2 et densité de protons (DP). Les résultats sur sept patients atteints de tumeur montrent l'efficacité de notre système.
10
Trébuchet, Guillaume. "Segmentation par contours actifs de séquences de vélocimétrie IRM : application aux artères carotides." Angers, 2013. https://tel.archives-ouvertes.fr/tel-00956813.
Анотація:
La vélocimétrie par IRM est une modalité intéressante pour explorer des pathologies cardiovasculaires. La séquence d’IRM en contraste de phase a la particularité de fournir à la fois des informations anatomiques et des informations physiologiques, permettant ainsi de mesurer les propriétés géométriques des vaisseaux ainsi que leurs propriétés hémodynamiques. Le but de cette thèse est d’automatiser la segmentation des vaisseaux et les mesures de vélocimétrie, un traitement manuel étant inadapté à une exploitation de la vélocimétrie IRM à des fins diagnostiques en routine clinique. Les travaux menés ont conduit à proposer une méthode de segmentation basée sur les contours actifs guidés par une information région (approche « région »), contrairement aux approches classiques se focalisant uniquement sur les frontières inter-régions (approche « contour »). Cette approche « région » a été évaluée sur des données provenant d’un fantôme réalisé afin de disposer d’une référence objective. Une seconde évaluation a été réalisée sur une base de 28 carotides (14 patients) segmentées manuellement par un radiologue expert. Les résultats obtenus sur les données « fantôme » montrent que l’approche « contour » conduit à une erreur de mesure de l’aire de la lumière de la carotide segmentée et de la mesure du flux de respectivement 18. 4 % et 3. 6 %. Ces erreurs sont plus importantes que celles obtenues en utilisant l’approche proposée (respectivement 2. 3 % et 0. 7 %). Ce bénéfice apparaît encore bien supérieur sur la base de patients avec une sous-estimation des aires et débits sanguins de respectivement 40. 5 % et 26. 5 % pour l’approche « contour », contre 14,7 et 6. 4 % pour l’approche proposéeMRI Velocimetry is a useful modality to explore cardiovascular disease. The sequence of phase contrast MRI has the characteristic of providing both anatomical information and the physiological data, thus allow to measure geometric properties of vessels and blood flows. The purpose of this thesis is to automate the segmentation of vessels and velocimetry measurements, manual processing is inadequate to operate the MRI velocimetry for a diagnostic in clinical routine. The work led to propose a segmentation method based on active contours guided by an information region ("region-based" approach), unlike conventional approaches focusing only on cross-border regions ("edge-based" approach). This "region-based" approach was evaluated on data from a phantom made to provide an objective reference. A second evaluation was conducted on the basis of 28 carotid arteries (14 patients) manually segmented by an expert radiologist. The results of the "phantom" data show that the "edge-based" approach leads to an error in measuring the area of the lumen of the segmented carotid and extent linked flows, respectively 18. 4 % and 3. 6%. These errors are larger than those obtained using the proposed approach (respectively 2. 3 % and 0. 7 %). This benefit appears much higher on the database of patients with an underestimation of areas and blood flow, respectively 40. 5 % and 26. 5 % for the "edge-based" approach, against 14. 7 and 6. 4 % for the proposed approach
Книги з теми "Techniques IRM":
1
Charlotte, Brooks, and International Business Machines Corporation. International Technical Support Organization., eds. ILM Library: Techniques with Tivoli storage and IBM TotalStorage products. [United States?]: IBM, International Technical Support Organization, 2006.
2
Andrew, Todd-Pokropek, Viergever M. A, North Atlantic Treaty Organization. Scientific Affairs Division., and NATO Advanced Study Institute on the Formation, Handling, and Evaluation of Medical Images (1988 : Povoa de Varzim, Portugal), eds. Medical images: Formation, handling, and evaluation. Berlin: Springer-Verlag, 1992.
3
David, Mitchell. An adventure in programming techniques. Wokingham England: Addison-Wesley Pub. Co., 1986.
4
Carrabis, Joseph-David. Hard Disk Management Techniques for the IBM. Indianapolis, IN: Howard W. Sams & Co., 1988.
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Corsi, Jerome R. Debugging techniques for IBM PC BASIC. New York, NY: Brady Communications Co., 1986.
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1953-, Riehl Dan, ed. AS/400 powertools: Tips and techniques from News 3X/400. Loveland, Colo: Duke Press, 1991.
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Carrabis, Joseph David. Hard disk management techniques for the IBM. Indianapolis: H.W.Sams, 1987.
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Hall, Brian. Performance optimization and tuning techniques for IBM processors, including IBM POWER8. Poughkeepsie, NY: IBM Corp., International Technical Support Organization, 2014.
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Sloan, Jim. Jim Sloan's CL tips & techniques. Loveland, Colo: Duke Press, 1994.
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Chuck, Lundgren, ed. S/36 power tools: Tips and techniques from NEWS 3X/400. Loveland, Colo: Duke Press, 1991.
Частини книг з теми "Techniques IRM":
1
Al Sharkawy, Mohamed H., Veysel Demir, and Atef Z. Elsherbeni. "Combined Multigrid Technique and IMR Algorithm." In Electromagnetic Scattering Using the Iterative Multiregion Technique, 75–85. Cham: Springer International Publishing, 2007. http://dx.doi.org/10.1007/978-3-031-01702-5_7.
2
Patel, Lakshman Chandra. "Application of IPM Techniques, Integration and Case Studies." In Applied Entomology, 310–22. London: CRC Press, 2023. http://dx.doi.org/10.1201/9781032627809-16.
3
Abay, Solomon, and Adam B. Winick. "Biopsy Techniques." In IR Playbook, 451–61. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-71300-7_41.
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Rice, Samuel L., and Auh Whan Park. "Biopsy Techniques." In IR Playbook, 455–65. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-52546-9_37.
5
Tzeng, Gwo-Hshiung. "DEMATEL Technique for Forming INRM and DANP Weights." In New Concepts and Trends of Hybrid Multiple Criteria Decision Making, 49–60. New York : CRC Press, 2017.: CRC Press, 2017. http://dx.doi.org/10.1201/9781315166650-4.
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Hutchinson, W. E. "The Use of Systems Techniques in Integrated Catchment Management (ICM)." In Critical Issues in Systems Theory and Practice, 681–86. Boston, MA: Springer US, 1995. http://dx.doi.org/10.1007/978-1-4757-9883-8_105.
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Al Sharkawy, Mohamed H., Veysel Demir, and Atef Z. Elsherbeni. "IMR Technique for Large-Scale Electromagnetic Scattering Problems:2D Case." In Electromagnetic Scattering Using the Iterative Multiregion Technique, 39–53. Cham: Springer International Publishing, 2007. http://dx.doi.org/10.1007/978-3-031-01702-5_4.
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D’Eramo, C., E. Caleffi, and A. Bocchi. "Sedation and Analgesia: an i.m.—i.v. Technique for Dressing Procedures." In The Management of Burns and Fire Disasters: Perspectives 2000, 327–28. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-009-0361-6_57.
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Lotov, Alexander V., Vladimir A. Bushenkov, and Georgy K. Kamenev. "Epilogue: New applications of the IDM technique on the Web." In Interactive Decision Maps, 279–87. Boston, MA: Springer US, 2004. http://dx.doi.org/10.1007/978-1-4419-8851-5_10.
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Riexinger, Günther, David J. Regina, Christoph Haar, Tobias Schmid-Schirling, Inga Landwehr, Michael Seib, Jonas Lips, et al. "Traceability in Battery Production: Cell-Specific Marker-Free Identification of Electrode Segments." In Advances in Automotive Production Technology – Towards Software-Defined Manufacturing and Resilient Supply Chains, 344–53. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27933-1_32.
Анотація:
AbstractDigitalization in battery production, as well as the increase and stabilization of product quality of lithium-ion battery cells, require the elimination of information gaps between processes to enable the traceability of components and process steps to the finished product. In lithium-ion battery cell manufacturing, using a traceability system is considered a promising approach to reduce scrap rates and enable more efficient production. Today, traceability is possible from the assembled cell onwards. However, with a view to the new EU battery regulation, complete traceability down to the material needs to be ensured. One of the challenges in this context is to ensure both, traceability in continuous electrode production and cell-specific identification within the production chain. This paper presents an approach for identifying individual electrode segments without identification markers, using the individual microstructure of the electrode surface. The Fraunhofer Institute for Manufacturing Engineering and Automation IPA and the Fraunhofer Institute for Physical Measurement Techniques IPM are further developing and testing an identification technique known as Track & Trace Fingerprint. This technique is dedicated to serialization within battery production as part of the joint project DigiBattPro 4.0 and to be implemented at the Center for Digitalized Battery Cell Manufacturing (ZDB) of Fraunhofer IPA.
Тези доповідей конференцій з теми "Techniques IRM":
1
Manouchehri, Soheil. "Subsea Pipelines and Flowlines Decommissioning: What We Should Know for a Rational Approach." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61239.
Анотація:
Offshore and subsea decommissioning will increase in the next five years or so as many producing fields are matured and cease production while the oil price continues to remain low. This emphasizes the need for a thorough decommissioning plan to ensure a safe and technically feasible solution while it is economically viable and safeguards the environment. Offshore and subsea decommissioning is commonly considered on a case-by-case basis using the Comparative Assessment (CA) process in which the best decommissioning solution is obtained. Health, Safety and Environmental (HSE) considerations are always paramount in any decommissioning process. The aim is to significantly reduce the long term risks to other benefactors of the sea while the associated short term risks to those responsible for decommissioning operations are minimized. A major part of any decommissioning project is subsea pipelines decommissioning (by “pipelines”, it is meant to include flowlines, trunklines and flexible too). There are a number of techniques available for decommissioning of subsea pipelines ranging from preservation for potential future use to full recovery or leaving in-situ. However, each subsea pipeline decommissioning technique should be considered on its own merit. Selection of each decommissioning technique depends on many parameters, inter alia, size of pipeline, type of pipeline (e.g. single pipe, pipe-in-pipe, piggyback), type of conveying fluid, operational environment (location), production history, Inspection, Repair and Maintenance (IRM) records, HSE considerations, connection to other facilities, technical feasibility (including potential use of advanced technologies), regulatory authorities requirements and socio-economic considerations. This paper will look at specifics of subsea pipelines decommissioning. It will examine the procedures to be undertaken from desk top activities (e.g. planning and CA) up to operational activities (e.g. pigging, flushing, cleaning, removal or leaving in-situ). Different scenarios are discussed and potential advantages and disadvantages of each scenario are presented. In addition, a guide is proposed for future pipelines decommissioning projects to follow a rational approach.
2
Segura-Bowers, Brent, Gareth Edwards, and John Knoll. "ILM VFX." In SIGGRAPH '17: Special Interest Group on Computer Graphics and Interactive Techniques Conference. New York, NY, USA: ACM, 2017. http://dx.doi.org/10.1145/3078280.3101048.
3
Segura-Bowers, Brent, Jordan Vogt-Roberts, Jeff White, and Brent Segura-Bowers. "ILM VFX." In SIGGRAPH '17: Special Interest Group on Computer Graphics and Interactive Techniques Conference. New York, NY, USA: ACM, 2017. http://dx.doi.org/10.1145/3078280.3106000.
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Knoll, John, Vick Schutz, Stephen Ellis, Russell Paul, and John Levin. "ILM presents." In SIGGRAPH '17: Special Interest Group on Computer Graphics and Interactive Techniques Conference. New York, NY, USA: ACM, 2017. http://dx.doi.org/10.1145/3078345.3099607.
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Bluff, Richard, Rachel Rose, Joseph Kasparian, Patrick Gehlen, Hal Hickel, Charmaine Chan, and Safari Sosebee. "ILM presents." In SIGGRAPH '21: Special Interest Group on Computer Graphics and Interactive Techniques Conference. New York, NY, USA: ACM, 2021. http://dx.doi.org/10.1145/3446368.3452368.
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Van Hulse, Jason, Taghi M. Khoshgoftaar, and Amri Napolitano. "An empirical comparison of repetitive undersampling techniques." In Integration (IRI). IEEE, 2009. http://dx.doi.org/10.1109/iri.2009.5211614.
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Cantwell, Brian, Paige Warner, Michael Koperwas, and Kiran Bhat. "ILM facial performance capture." In SIGGRAPH '16: Special Interest Group on Computer Graphics and Interactive Techniques Conference. New York, NY, USA: ACM, 2016. http://dx.doi.org/10.1145/2897839.2927438.
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Chuhan, Kooj. "What if I'm not real." In SIGGRAPH07: Special Interest Group on Computer Graphics and Interactive Techniques Conference. New York, NY, USA: ACM, 2007. http://dx.doi.org/10.1145/1280120.1280137.
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Helman, Pablo, Leandro Estebecorena, and Stephane Grabli. "ILM presents: making "The Irishman"." In SIGGRAPH '20: Special Interest Group on Computer Graphics and Interactive Techniques Conference. New York, NY, USA: ACM, 2020. http://dx.doi.org/10.1145/3368850.3383427.
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Segura-Bowers, Brent. "ILM 2019 - Behind the Magic." In SIGGRAPH '19: Special Interest Group on Computer Graphics and Interactive Techniques Conference. New York, NY, USA: ACM, 2019. http://dx.doi.org/10.1145/3302502.3339250.
Звіти організацій з теми "Techniques IRM":
1
Feng, Chitao. Review of Development of IR Guidance Techniques. Part 1,. Fort Belvoir, VA: Defense Technical Information Center, March 1996. http://dx.doi.org/10.21236/ada306537.
2
Torres, Joseph A. Structural analysis of an ancient pottery by using FT-IR technique. Office of Scientific and Technical Information (OSTI), March 2013. http://dx.doi.org/10.2172/1068955.
3
Ben-Shalom, Ami, Adam Devir, and Leslie Salem. Development and Validation of Measurement Techniques of Transmittance of Thermal Contrast Utilizing Existing IR Imagers. Fort Belvoir, VA: Defense Technical Information Center, July 1988. http://dx.doi.org/10.21236/ada204920.
4
Kiefner. L51606 Technique Development for Polarized Pipe-to-Soil Potential Measurements. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), December 1989. http://dx.doi.org/10.55274/r0010103.
Анотація:
In the recent past years there has been a considerable amount of effort devoted to developing methods and instruments to correct measured pipe-to-soil potentials for IR drops that may occur from currents (from the cathodic protection system or stray sources) in the soil to obtain the polarized potential. However, many of the methods or instruments available are either time-consuming, cumbersome to use in the field, applicable to only certain types of cathodic protection systems and under particular circumstances, subject to influences from stray current sources or not fully developed as of yet. Thus, there is a need to develop a practical method of determining the polarized pipe potential free of IR drop errors. This report examines and compares seven available methods for measuring polarized potential and describes the advantages and disadvantages of each. The following methods for measuring polarized potential were evaluated: (1) pipe-to-soil measurements with cathodic protection; (2) pipe-to-soil measurements with interrupted cathodic protection (also called instant-off); (3) measurements based on rectifier AC waveform analysis; (4) stepped current reduction; (5) a four-terminal network; (6) extrapolation to zero resistance (IR drop); and (7) a combination of DC/AC transverse measurements.
5
Zhang, Hengdi, Yunming Li, Guangyu Chen, Fei Han, and Wei Jiang. Human amniotic membrane graft for refractory macular hole: a single-arm meta analysis and systematic review. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, February 2022. http://dx.doi.org/10.37766/inplasy2022.2.0098.
Анотація:
Review question / Objective: Currently, pars plana vitrectomy (PPV) with ILM peeling is the gold standard treatment for full thickness macular hole (FTMH). Despite of the high macular hole closure rate, a refractory FTMH may occur. The next step for a recurrent or persistent MH is usually repeat PPV with extended ILM peeling. This is not always an option especially with high myopia patients or those who had already undergone an aggressive ILM peeling at initial surgery. A variety of novel techniques have been developed to address this issue, among which human amniotic membrane seems to be a promising adjuvant. However, there are still uncertainties regarding the integration and the long-term effects of of the graft. Information sources: PubMed, Embase, Web of science, Cochrane library, Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure databases, sinomed (CBM), VIP database, Clinical Trails.gov and Chinese Clinical Trail Registry.
6
Agassi, Menahem, Michael J. Singer, Eyal Ben-Dor, Naftaly Goldshleger, Donald Rundquist, Dan Blumberg, and Yoram Benyamini. Developing Remote Sensing Based-Techniques for the Evaluation of Soil Infiltration Rate and Surface Roughness. United States Department of Agriculture, November 2001. http://dx.doi.org/10.32747/2001.7586479.bard.
Анотація:
The objective of this one-year project was to show whether a significant correlation can be established between the decreasing infiltration rate of the soil, during simulated rainstorm, and a following increase in the reflectance of the crusting soil. The project was supposed to be conducted under laboratory conditions, using at least three types of soils from each country. The general goal of this work was to develop a method for measuring the soil infiltration rate in-situ, solely from the reflectance readings, using a spectrometer. Loss of rain and irrigation water from cultivated fields is a matter of great concern, especially in arid, semi-arid regions, e.g. much of Israel and vast area in US, where water is a limiting factor for crop production. A major reason for runoff of rain and overhead irrigation water is the structural crust that is generated over a bare soils surface during rainfall or overhead irrigation events and reduces its infiltration rate (IR), considerably. IR data is essential for predicting the amount of percolating rainwater and runoff. Available information on in situ infiltration rate and crust strength is necessary for the farmers to consider: when it is necessary to cultivate for breaking the soil crust, crust strength and seedlings emergence, precision farming, etc. To date, soil IR is measured in the laboratory and in small-scale field plots, using rainfall simulators. This method is tedious and consumes considerable resources. Therefore, an available, non-destructive-in situ methods for soil IR and soil crusting levels evaluations, are essential for the verification of infiltration and runoff models and the evaluation of the amount of available water in the soil. In this research, soil samples from the US and Israel were subjected to simulated rainstorms of increasing levels of cumulative energies, during which IR (crusting levels) were measured. The soils from the US were studied simultaneously in the US and in Israel in order to compare the effect of the methodology on the results. The soil surface reflectance was remotely measured, using laboratory and portable spectrometers in the VIS-NIR and SWIR spectral region (0.4-2.5mm). A correlation coefficient spectra in which the wavelength, consisting of the higher correlation, was selected to hold the highest linear correlation between the spectroscopy and the infiltration rate. There does not appear to be a single wavelength that will be best for all soils. The results with the six soils in both countries indeed showed that there is a significant correlation between the infiltration rate of crusted soils and their reflectance values. Regarding the wavelength with the highest correlation for each soil, it is likely that either a combined analysis with more then one wavelength or several "best" wavelengths will be found that will provide useful data on soil surface condition and infiltration rate. The product of this work will serve as a model for predicting infiltration rate and crusting levels solely from the reflectance readings. Developing the aforementioned methodologies will allow increased utilization of rain and irrigation water, reduced runoff, floods and soil erosion hazards, reduced seedlings emergence problems and increased plants stand and yields.
7
Irudayaraj, Joseph, Ze'ev Schmilovitch, Amos Mizrach, Giora Kritzman, and Chitrita DebRoy. Rapid detection of food borne pathogens and non-pathogens in fresh produce using FT-IRS and raman spectroscopy. United States Department of Agriculture, October 2004. http://dx.doi.org/10.32747/2004.7587221.bard.
Анотація:
Rapid detection of pathogens and hazardous elements in fresh fruits and vegetables after harvest requires the use of advanced sensor technology at each step in the farm-to-consumer or farm-to-processing sequence. Fourier-transform infrared (FTIR) spectroscopy and the complementary Raman spectroscopy, an advanced optical technique based on light scattering will be investigated for rapid and on-site assessment of produce safety. Paving the way toward the development of this innovative methodology, specific original objectives were to (1) identify and distinguish different serotypes of Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Bacillus cereus by FTIR and Raman spectroscopy, (2) develop spectroscopic fingerprint patterns and detection methodology for fungi such as Aspergillus, Rhizopus, Fusarium, and Penicillium (3) to validate a universal spectroscopic procedure to detect foodborne pathogens and non-pathogens in food systems. The original objectives proposed were very ambitious hence modifications were necessary to fit with the funding. Elaborate experiments were conducted for sensitivity, additionally, testing a wide range of pathogens (more than selected list proposed) was also necessary to demonstrate the robustness of the instruments, most crucially, algorithms for differentiating a specific organism of interest in mixed cultures was conceptualized and validated, and finally neural network and chemometric models were tested on a variety of applications. Food systems tested were apple juice and buffer systems. Pathogens tested include Enterococcus faecium, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus, Yersinia enterocolitis, Shigella boydii, Staphylococus aureus, Serratiamarcescens, Pseudomonas vulgaris, Vibrio cholerae, Hafniaalvei, Enterobacter cloacae, Enterobacter aerogenes, E. coli (O103, O55, O121, O30 and O26), Aspergillus niger (NRRL 326) and Fusarium verticilliodes (NRRL 13586), Saccharomyces cerevisiae (ATCC 24859), Lactobacillus casei (ATCC 11443), Erwinia carotovora pv. carotovora and Clavibacter michiganense. Sensitivity of the FTIR detection was 103CFU/ml and a clear differentiation was obtained between the different organisms both at the species as well as at the strain level for the tested pathogens. A very crucial step in the direction of analyzing mixed cultures was taken. The vector based algorithm was able to identify a target pathogen of interest in a mixture of up to three organisms. Efforts will be made to extend this to 10-12 key pathogens. The experience gained was very helpful in laying the foundations for extracting the true fingerprint of a specific pathogen irrespective of the background substrate. This is very crucial especially when experimenting with solid samples as well as complex food matrices. Spectroscopic techniques, especially FTIR and Raman methods are being pursued by agencies such as DARPA and Department of Defense to combat homeland security. Through the BARD US-3296-02 feasibility grant, the foundations for detection, sample handling, and the needed algorithms and models were developed. Successive efforts will be made in transferring the methodology to fruit surfaces and to other complex food matrices which can be accomplished with creative sampling methods and experimentation. Even a marginal success in this direction will result in a very significant breakthrough because FTIR and Raman methods, in spite of their limitations are still one of most rapid and nondestructive methods available. Continued interest and efforts in improving the components as well as the refinement of the procedures is bound to result in a significant breakthrough in sensor technology for food safety and biosecurity.
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Upadhyaya, Shrini K., Abraham Shaviv, Abraham Katzir, Itzhak Shmulevich, and David S. Slaughter. Development of A Real-Time, In-Situ Nitrate Sensor. United States Department of Agriculture, March 2002. http://dx.doi.org/10.32747/2002.7586537.bard.
Анотація:
Although nitrate fertilizers are critical for enhancing crop production, excess application of nitrate fertilizer can result in ground water contamination leading to the so called "nitrate problem". Health and environmental problems related to this "nitrate problem" have led to serious concerns in many parts of the world including the United States and Israel. These concerns have resulted in legislation limiting the amount of nitrate N in drinking water to 10mg/g. Development of a fast, reliable, nitrate sensor for in-situ application can be extremely useful in dynamic monitoring of environmentally sensitive locations and applying site-specific amounts of nitrate fertilizer in a precision farming system. The long range objective of this study is to develop a fast, reliable, real-time nitrate sensor. The specific objective of this one year feasibility study was to explore the possible use of nitrate sensor based on mid-IR spectroscopy developed at UCD along with the silver halide fiber ATR (i.e. attenuated total internal reflection) sensor developed at TAU to detect nitrate content in solution and soil paste in the presence of interfering compounds. Experiments conducted at Technion and UCD clearly demonstrate the feasibility of detecting nitrate content in solutions as well as soil pastes using mid-IR spectroscopy and an ATR technique. When interfering compounds such as carbonates, bicarbonates, organic matter etc. are present special data analysis technique such as singular value decomposition (SYD) or cross correlation was necessary to detect nitrate concentrations successfully. Experiments conducted in Israel show that silver halide ATR fiber based FEWS, particularly flat FEWS, resulted in low standard error and high coefficient of determination (i.e. R² values) indicating the potential of the flat Fiberoptic Evanescent Wave Spectroscopy (FEWS) for direct determinations of nitrate. Moreover, they found that it was possible to detect nitrate and other anion concentrations using anion exchange membranes and M1R spectroscopy. The combination of the ion-exchange membranes with fiberoptices offers one more option to direct determination of nitrate in environmental systems.
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Sprague, Joshua, David Kushner, James Grunden, Jamie McClain, Benjamin Grime, and Cullen Molitor. Channel Islands National Park Kelp Forest Monitoring Program: Annual report 2014. National Park Service, August 2022. http://dx.doi.org/10.36967/2293855.
Анотація:
Channel Islands National Park (CHIS) has conducted long-term ecological monitoring of the kelp forests around San Miguel, Santa Rosa, Santa Cruz, Anacapa and Santa Barbara Islands since 1982. The original permanent transects were established at 16 sites between 1981 and 1986 with the first sampling beginning in 1982, this being the 33rd year of monitoring. An additional site, Miracle Mile, was established at San Miguel Island in 2001 by a commercial fisherman with assistance from the park. Miracle Mile was partially monitored from 2002 to 2004, and then fully monitored (using all KFM protocols) since 2005. In 2005, 16 additional permanent sites were established to collect baseline data from inside and adjacent to four marine reserves that were established in 2003. Sampling results from all 33 sites mentioned above are included in this report. Funding for the Kelp Forest Monitoring Program (KFM) in 2014 was provided by the National Park Service (NPS). The 2014 monitoring efforts utilized 49 days of vessel time to conduct 1,040 dives for a total of 1,059 hours of bottom time. Population dynamics of a select list of 71 “indicator species” (consisting of taxa or categories of algae, fish, and invertebrates) were measured at the 33 permanent sites. In addition, population dynamics were measured for all additional species of fish observed at the sites during the roving diver fish count. Survey techniques follow the CHIS Kelp Forest Monitoring Protocol Handbook (Davis et al. 1997) and an update to the sampling protocol handbook currently being developed (Kushner and Sprague, in progress). The techniques utilize SCUBA and surface-supplied-air to conduct the following monitoring protocols: 1 m2 quadrats, 5 m2 quadrats, band transects, random point contacts, fish transects, roving diver fish counts, video transects, size frequency measurements, and artificial recruitment modules. Hourly temperature data were collected using remote temperature loggers at 32 sites, the exception being Miracle Mile where there is no temperature logger installed. This annual report contains a brief description of each site including any notable observations or anomalies, a summary of methods used, and monitoring results for 2014. All the data collected during 2014 can be found in the appendices and in an Excel workbook on the NPS Integrated Resource Management Applications (IRMA) portal. In the 2013 annual report (Sprague et al. 2020) several changes were made to the appendices. Previously, annual report density and percent cover data tables only included the current year’s data. Now, density and percent cover data are presented in graphical format and include all years of available monitoring data. Roving diver fish count (RDFC), fish size frequency, natural habitat size frequency, and Artificial Recruitment Module (ARM) size frequency data are now stored on IRMA at https://irma.nps.gov/DataStore/Reference/Profile/2259651. The temperature data graphs in Appendix L include the same graphs that were used in past reports, but include additional violin plot sections that compare monthly means from the current year to past years. In addition to the changes listed above, the layout of the discussion section was reordered by species instead of by site. The status of kelp forests differed among the five park islands. This is a result of a combination of factors including but not limited to, oceanography, biogeography and associated differences in species abundance and composition, as well as sport and commercial fishing pressure. All 33 permanent sites were established in areas that had or were historically known to have had kelp forests in the past. In 2014, 15 of the 33 sites monitored were characterized as developing kelp forest, kelp forest or mature kelp forest. In addition, three sites were in a state of transition. Two sites were part kelp forest and part dominated by Strongylocentrotus purpuratus...
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Hibbert, Angela, and Begona Pérez Gómez. Operational monitoring systems available at the three sites. EuroSea, 2023. http://dx.doi.org/10.3289/eurosea_d5.9.
Анотація:
Tide gauges can capture sea level variability on multiple timescales, from high frequency events like waves, tides and tsunamis, to seasonal and interannual changes and the longer-term trends associated with Climate Change. However, financial constraints dictate that they are often maintained to lower standards than the stringent accuracy requirements demanded by the IOC-UNESCO’s Global Sea Level Observing System (GLOSS) for monitoring sea level rise. In addition, a sparsity of Global Navigation Satellite System (GNSS) receivers at the coast means that there are large uncertainties in rates of land motion at tide gauges, which also hampers the estimation of long-term sea level trends. Task 5.1.1 has devised prototype low maintenance tide gauge systems, powered by renewable energy and which monitor both land motion and sea level using novel techniques such as ground-based GNSS Interferometric Reflectometry (GNSS-IR). These systems eliminate the need for costly ongoing levelling exercises and also incorporate customisations to local monitoring needs, such as sensors for lightning detection and wave height. Despite a number of unforeseen setbacks, these prototype systems are now operating at 2 locations in the Mediterranean Sea and a third system is in transit to Colombia for installation by local stakeholders who have been trained in the installation methodology by the WP5 team. It is hoped that there is potential to advance these technological solutions as a global standard, via the GLOSS community. (EuroSea Deliverable, D5.9)