Bibliografias temáticas / MRI probe

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Literatura científica selecionada sobre o tema "MRI probe"

Autor: Grafiati

Publicado: 8 de fevereiro de 2025

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Artigos de revistas sobre o assunto "MRI probe"

Periyathambi, Prabu, Alien Balian, Zhangjun Hu, Daniel Padro, Luiza I. Hernandez, Kajsa Uvdal, Joao Duarte e Frank J. Hernandez. "Activatable MRI probes for the specific detection of bacteria". Analytical and Bioanalytical Chemistry 413, n.º 30 (27 de outubro de 2021): 7353–62. http://dx.doi.org/10.1007/s00216-021-03710-z.

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AbstractActivatable fluorescent probes have been successfully used as molecular tools for biomedical research in the last decades. Fluorescent probes allow the detection of molecular events, providing an extraordinary platform for protein and cellular research. Nevertheless, most of the fluorescent probes reported are susceptible to interferences from endogenous fluorescence (background signal) and limited tissue penetration is expected. These drawbacks prevent the use of fluorescent tracers in the clinical setting. To overcome the limitation of fluorescent probes, we and others have developed activatable magnetic resonance probes. Herein, we report for the first time, an oligonucleotide-based probe with the capability to detect bacteria using magnetic resonance imaging (MRI). The activatable MRI probe consists of a specific oligonucleotide that targets micrococcal nuclease (MN), a nuclease derived from Staphylococcus aureus. The oligonucleotide is flanked by a superparamagnetic iron oxide nanoparticle (SPION) at one end, and by a dendron functionalized with several gadolinium complexes as enhancers, at the other end. Therefore, only upon recognition of the MRI probe by the specific bacteria is the probe activated and the MRI signal can be detected. This approach may be widely applied to detect bacterial infections or other human conditions with the potential to be translated into the clinic as an activatable contrast agent.

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Faas, Henryk M., James L. Krupa, Alexander J. Taylor, Francesco Zamberlan, Christopher J. Philp, Huw E. L. Williams, Simon R. Johnson, Galina E. Pavlovskaya, Neil R. Thomas e Thomas Meersmann. "Accelerated 19F·MRI Detection of Matrix Metalloproteinase-2/-9 through Responsive Deactivation of Paramagnetic Relaxation Enhancement". Contrast Media & Molecular Imaging 2019 (28 de fevereiro de 2019): 1–13. http://dx.doi.org/10.1155/2019/4826520.

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Paramagnetic gadolinium ions (GdIII), complexed within DOTA-based chelates, have become useful tools to increase the magnetic resonance imaging (MRI) contrast in tissues of interest. Recently, “on/off” probes serving as 19F·MRI biosensors for target enzymes have emerged that utilize the increase in transverse (T2∗ or T2) relaxation times upon cleavage of the paramagnetic GdIII centre. Molecular 19F·MRI has the advantage of high specificity due to the lack of background signal but suffers from low signal intensity that leads to low spatial resolution and long recording times. In this work, an “on/off” probe concept is introduced that utilizes responsive deactivation of paramagnetic relaxation enhancement (PRE) to generate 19F longitudinal (T1) relaxation contrast for accelerated molecular MRI. The probe concept is applied to matrix metalloproteinases (MMPs), a class of enzymes linked with many inflammatory diseases and cancer that modify bioactive extracellular substrates. The presence of these biomarkers in extracellular space makes MMPs an accessible target for responsive PRE deactivation probes. Responsive PRE deactivation in a 19F biosensor probe, selective for MMP-2 and MMP-9, is shown to enable molecular MRI contrast at significantly reduced experimental times compared to previous methods. PRE deactivation was caused by MMP through cleavage of a protease substrate that served as a linker between the fluorine-containing moiety and a paramagnetic GdIII-bound DOTA complex. Ultrashort echo time (UTE) MRI and, alternatively, short echo times in standard gradient echo (GE) MRI were employed to cope with the fast 19F transverse relaxation of the PRE active probe in its “on-state.” Upon responsive PRE deactivation, the 19F·MRI signal from the “off-state” probe diminished, thereby indicating the presence of the target enzyme through the associated negative MRI contrast. Null point 1H·MRI, obtainable within a short time course, was employed to identify false-positive 19F·MRI responses caused by dilution of the contrast agent.

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Antonios, Joseph P., Horacio Soto, Richard G. Everson, Diana L. Moughon, Anthony C. Wang, Joey Orpilla, Caius Radu et al. "Detection of immune responses after immunotherapy in glioblastoma using PET and MRI". Proceedings of the National Academy of Sciences 114, n.º 38 (5 de setembro de 2017): 10220–25. http://dx.doi.org/10.1073/pnas.1706689114.

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Contrast-enhanced MRI is typically used to follow treatment response and progression in patients with glioblastoma (GBM). However, differentiating tumor progression from pseudoprogression remains a clinical dilemma largely unmitigated by current advances in imaging techniques. Noninvasive imaging techniques capable of distinguishing these two conditions could play an important role in the clinical management of patients with GBM and other brain malignancies. We hypothesized that PET probes for deoxycytidine kinase (dCK) could be used to differentiate immune inflammatory responses from other sources of contrast-enhancement on MRI. Orthotopic malignant gliomas were established in syngeneic immunocompetent mice and then treated with dendritic cell (DC) vaccination and/or PD-1 mAb blockade. Mice were then imaged with [18F]-FAC PET/CT and MRI with i.v. contrast. The ratio of contrast enhancement on MRI to normalized PET probe uptake, which we term the immunotherapeutic response index, delineated specific regions of immune inflammatory activity. On postmortem examination, FACS-based enumeration of intracranial tumor-infiltrating lymphocytes directly correlated with quantitative [18F]-FAC PET probe uptake. Three patients with GBM undergoing treatment with tumor lysate-pulsed DC vaccination and PD-1 mAb blockade were also imaged before and after therapy using MRI and a clinical PET probe for dCK. Unlike in mice, [18F]-FAC is rapidly catabolized in humans; thus, we used another dCK PET probe, [18F]-clofarabine ([18F]-CFA), that may be more clinically relevant. Enhanced [18F]-CFA PET probe accumulation was identified in tumor and secondary lymphoid organs after immunotherapy. Our findings identify a noninvasive modality capable of imaging the host antitumor immune response against intracranial tumors.

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Pulyer Yuly, M., e Samuel Patz. "5572132 MRI probe for external imaging". Magnetic Resonance Imaging 15, n.º 4 (janeiro de 1997): XVII. http://dx.doi.org/10.1016/s0730-725x(97)89062-5.

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Kotera, Naoko, Nawal Tassali, Estelle Léonce, Céline Boutin, Patrick Berthault, Thierry Brotin, Jean-Pierre Dutasta et al. "A Sensitive Zinc-Activated129Xe MRI Probe". Angewandte Chemie International Edition 51, n.º 17 (12 de março de 2012): 4100–4103. http://dx.doi.org/10.1002/anie.201109194.

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Kotera, Naoko, Nawal Tassali, Estelle Léonce, Céline Boutin, Patrick Berthault, Thierry Brotin, Jean-Pierre Dutasta et al. "A Sensitive Zinc-Activated129Xe MRI Probe". Angewandte Chemie 124, n.º 17 (12 de março de 2012): 4176–79. http://dx.doi.org/10.1002/ange.201109194.

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Hillery, Terence. "Genicular Nerve Radiofrequency Ablation Before and After Magnetic Resonance Imaging Anatomical Mapping: Case Study". Pain Medicine Case Reports 7, n.º 4 (31 de julho de 2023): 183–86. http://dx.doi.org/10.36076/pmcr.2023.7.183.

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Background: Chronic knee pain is a significant cause of morbidity for which radiofrequency ablation (RFA) of genicular nerves (GN) may be considered. However, treatment effectiveness depends on accurate placement of RFA probes, and there remains uncertainty on GN anatomical location. Case Report: A 21-year-old man presented with 2 months of severe knee pain following a canoe trip. Hoffa’s fat impingement was diagnosed with magnetic resonance imaging (MRI), and a subsequent fat pad injection was unsuccessful. After GN blocks, RFA provided 90% relief for 4 weeks. At this time, RFA was performed with probe placement determined by the patient’s MRI-mapped GN neurovascular bundle location. At 8 weeks, the patient continues to have 100% left knee pain relief. Conclusion: This case suggests that MRI-mapped GNs may assist in planning genicular RFA to improve probe and nerve apposition. Key words: Genicular nerve, magnetic resonance imaging, radiofrequency ablation

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Pinggera, Daniel, Paul Rhomberg, Ronny Beer, Claudius Thomé e Ondra Petr. "Brain Tissue Damage Induced by Multimodal Neuromonitoring In Situ during MRI after Severe Traumatic Brain Injury: Incidence and Clinical Relevance". Journal of Clinical Medicine 11, n.º 11 (2 de junho de 2022): 3169. http://dx.doi.org/10.3390/jcm11113169.

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Both neuromonitoring and early magnetic resonance imaging (MRI) provide crucial information for treatment management and prognosis in patients with severe traumatic brain injury (sTBI). So far, neuromonitoring in situ impedes the routine implementation of MRI due to safety concerns. We aimed to evaluate the brain tissue damage induced by inserted neuromonitoring devices and its clinical relevance. Nineteen patients with sTBI and being exposed to at least one MRI with neuromonitoring in situ and one follow-up MRI after neuromonitoring removal were analyzed. All MRIs were reviewed for specific tissue damage. Three females and sixteen males (aged 20–74 years, mean 42.8 years) with an initial median GCS of 5 (range 3–8) were analyzed. No lesion was observed in six patients (31.6%), whereas another six patients (31.6%) demonstrated a detectable probe trajectory. Probe-related tissue damage was visible in seven patients (36.8%) with the size of the lesion prone to further enlarge with increasing cumulative duration of MRI examinations. Upon interdisciplinary evaluation, the lesions were not considered clinically relevant. Neuromonitoring probes in situ during MRI examinations may cause local brain tissue damage, yet without any clinical implications if placed correctly. Therefore, indications must be strictly based on joint decision from all involved disciplines.

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Kim, Ji Min, Ah Yung Han, Ha Young Lee, So Ra Lee e Dae Cheol Kweon. "Measurement of MRI Monitor Luminance and MRI Room Illuminance with a Light Probe". Journal of the Korean Magnetics Society 26, n.º 5 (31 de outubro de 2016): 168–72. http://dx.doi.org/10.4283/jkms.2016.26.5.168.

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Jain, Amit L., Abhinav Sidana, Zachary Stanik, Mahir Maruf, Brian P. Calio, Dordaneh Sugano, Kai Hans Hammerich et al. "Training and skills assessment for MRI/TRUS fusion-guided prostate biopsy: End-fire vs. side-fire ultrasound probes." Journal of Clinical Oncology 35, n.º 6_suppl (20 de fevereiro de 2017): e540-e540. http://dx.doi.org/10.1200/jco.2017.35.6_suppl.e540.

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e540 Background: Magnetic resonance imaging (MRI)/transrectal ultrasound (TRUS) fusion-guided prostate biopsy (FBx) has rapidly proliferated in prostate cancer evaluation. FBx success may be dependent on multiple factors, including skills learned with user experience and the type of ultrasound (US) probe used. Our objective of this study was to compare the accuracy of the MRI/TRUS FBx technique utilizing an end fire versus a side fire US probe on an FBx platform. Methods: The participants of the study consisted of three different experience levels (expert ( > 1000 FBx), Urology fellows with none to minimal FBx experience, Urology residents with no FBx experience). Each participant performed three trials of the FBx with the UroNav System in separate phantom models of the prostate. Each trial involved targeting the same set of fiducials through FBx platform and then using US only; first using an end fire US probe, and then using a side fire US probe. Fusion registration error (FRE) was defined as the distance between MR target and transformed core location from the US only biopsy. Results: Six users with 3 different experience levels performed the FBx. Mean FRE with the end fire probe for the residents, fellows, expert was 7.42(±0.11), 5.10(±0.73) & 3.75(±0.75) respectively. Mean FRE with the side fire probe for the residents, fellows, expert was 6.08(±0.09), 4.76(±0.68) & 3.46(±0.08) respectively. There was no significant difference between the FRE averages for end fire vs. side fire. There was an inverse relationship of mean FRE with user experience level (corr. coefficient (r) = -0.79, p = 0.011 for end fire; r = -0.84, p = 0.004 for side-fire). Conclusions: We report the results of a pilot study comparing the efficacy of side fire and end fire US probes in MRI/TRUS FBx. Our preliminary results suggest the type of US probe used does not significantly affect FRE and FBx performance. As expected, FRE decreases with increased user experience. A larger study with more participants will be needed to compare these probes with adequately powered analysis and will dictate the practice in clinical settings as minimization of FRE will improve diagnostic accuracy of this technique in detecting clinically significant cancer.

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Mais fontes

Teses / dissertações sobre o assunto "MRI probe"

Wu, Faye Y. "Multi-probe robotic positioner for cryoablation in MRI". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74953.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 116-118).
This thesis describes the design of a guidance device for faster and more accurate targeting of multiple probes during cryoablation and other percutaneous interventions performed in closed bore magnetic resonance (MR) imaging systems. The device is intended to be mounted onto a Siemens 110 mm MR loop coil that rests on the patient and contains a cable driven two-degree-of- freedom spherical mechanism that orientates the intervention probes about a remote center of motion located 15 mm above the skin entry point. A carriage, pulled by strong and low stretch cables, can position up to three intervention probes as it travels on a rotating hoop. Its motion is constrained by a custom designed roller bearing to minimize friction. A thumbscrew fastened latch allows a probe to be engaged in a guide that constrains the probe along a specific trajectory. The probe can also be disengaged from its track, freeing it to move with respiration and enabling the guide to be repositioned for another probe to be inserted. Compact MR compatible piezoelectric motors are used to actuate the system. A prototype was built from 3D printed ABS plastic as a proof of concept. Bench level evaluation demonstrated that each component of the device performs according to the design specifications. The device performance was characterized by analyzing still images taken before and after movement, which yielded sub-degree accuracy, sub-degree repeatability near vertical position, and an incremental step resolution of at least 0.5 degree. Upon further developments of the registration and calibration modules in 3D slicer to interface the robot with image data, evaluation of the device in MRI will be performed.
by Faye Y. Wu.
S.M.

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Khachaturian, Mark Haig 1979. "Advances in MRI to probe the functional and structural network of the macaque brain". Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/44785.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2007.
Includes bibliographical references (leaves 95-103).
Diffusion MRI and fMRI have provided neuroscientists with non-invasive tools to probe the functional and structural network of the brain. Diffusion MRI is a neuroimaging technique capable of measuring the diffusion of water in neural tissue. It can reveal histological architecture irresolvable by conventional magnetic resonance imaging methods and has emerged as a powerful tool to investigate a wide range of neuropathologies. fMRI is a neuroimaging technique sensitive to hemodynamics which is indirectly linked to neural activity. Despite the applications of diffusion MRI and fMRI in basic and clinical neuroscience, the underlying biophysical mechanisms of cerebral diffusion and the hemodynamic response remain largely unknown. Also, these neurotechnqiues suffer from low SNR compared to conventional MRI. The challenges associated with the acquisition and interpretation of diffusion MRI and fMRI limit the application of these powerful non-invasive neuroimaging tools to study the functional and structural network of the brain. The purpose of this thesis is three fold; (1) improve the acquisition and reconstruction of the diffusion MRI and fMRI signals and (2) develop an MR-compatible cortical cooling system to reversibly deactivate cerebral glucose metabolism, and (3) apply the cortical cooling system to investigate the effect of cerebral glucose metabolism on cerebral diffusion and the hemodynamic response. First, I describe a novel phased array monkey coil capable of improving the resolution of diffusion MRI (4 fold increase) and fMRI (2 fold increase) in monkeys. Secondly, I present a novel reconstruction method to resolve complex white matter architecture which boosts the sampling efficiency of the diffusion MRI acquisition by 274-377%.
(cont.) Thirdly, I present a MR-compatible cortical cooling system capable of reversibly deactivating cerebral metabolism in monkeys. The cortical cooling system has been applied to study the effect of cerebral glucose metabolism on the cerebral diffusion of water. I use MR temperature maps to quantify the region and degree of deactivation (accuracy of ±1 °C in vivo). Then, I show that reversible deactivation of cerebral glucose metabolism affects the magnitude of cerebral diffusion (12-20%) but not the anisotropy. Finally, I apply the cortical cooling system to study the effect of reversibly deactivating cerebral glucose metabolism in V1 and its effect on the hemodynamic response in the visual system. Reversible deactivation of V1 decreased the hemodynamic response in visually driven regions upstream and downstream from V1. Compensatory effects were observed in V1 in both hemispheres and ipsilateral TEO with in 2 minutes of deactivation. Here I have described the tools to probe the functional and structural network of the macaque brain.
by Mark Haig Khachaturian.
Ph.D.

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Bortolotti, Laura. "Test of multiple sensor set-up for head motion characterization during MRI acquisition". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14564/.

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L'Imaging a Risonanza Magnetica (MRI) è una tecnica di imaging ampiamente utilizzata in ambito medico. La ricerca in questo campo si sta focalizzando sullo sviluppo di scanner a campi molto intensi, come lo scanner a 7 T utilizzato in questa tesi. La risoluzione delle immagini e l'entità degli artefatti creati dai movimenti involontari del paziente sono proporzionali all'intensità di campo magnetico e diventano rilevanti ad intensità molto elevate. Le tecniche di Motion Correction, nota la cinetica dei movimenti, permettono di correggere queste distorsioni. La tesi è inserita in un progetto che ha come scopo la misura indiretta dei movimenti della testa durante la scansione MRI. In particolare, mi sono concentrata sui miglioramenti da apportare al set-up e sulla caratterizzazione dei tre strumenti usati per la misura: la telecamera di campo magnetico (Clip on Camera Head, CCH) formata da 16 sonde fissate in una struttura cilindrica posizionata attorno alla testa del paziente; la telecamera ottica (Moiré Phase Tracking System, MPT) che misura i movimenti tramite l'immagine di un marker olografico supportato da un bite tenuto nella bocca del volontario; il dispositivo (Physlog) dello scanner che fornisce i parametri fisiologici (respirazione e battito cardiaco). La comunicazione hardware degli strumenti avviene grazie a un segnale di trigger, di cui ho ottimizzato la sincronizzazione. Inoltre, abbiamo acquisito dataset completi di tre volontari, a diverse condizioni. I dati sono stati sincronizzati e analizzati, tramite analisi multivariate, per caratterizzare la risposta e la stabilità del sistema e la variabilità individuale dei pazienti. L'analisi ha permesso di capire meglio le proprietà dello strumento e ha consentito di associare le misure del campo magnetico al di fuori del cranio ai valori fisiologici dei volontari.

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FATEHBASHARZAD, PARISA. "Functionalized Concave Cube Gold Nanoparticles as Dual probe for Magnetic Resonance Imaging and Surface Enhanced Raman Scattering". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2020. http://hdl.handle.net/10281/273768.

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An innovative class of MRI CAs is represented by Gd-loaded gold nanoparticles. Differently from other nano-sized systems, the size, shape and chemical functionalization appear to affect the observed relaxation enhancement of water protons in their suspensions. The herein reported results shed more light on the determinants of the relaxation enhancement brought by Gd-loaded concave cube gold nanoparticles. It has been found that the role of the concave surface of these nanoparticles in the relaxivity is remarkable and it provides high contribution of second sphere water molecules. The specific shape of concave cube nanoparticles increases the relaxivity from 20.9 mM-1S-1 for spherical nanoparticles to 36.3 mM-1S-1. On the other hand, our studies prove that this special shape gold nanoparticles show high efficiency as a SERS probe. In the single-particle surface-enhanced Raman spectroscopy, the use of tunable plasmonic nanoparticles, having tipped surface structures, as being substrates revealed a highly feasible and promising approach to optimize SERS-based imaging and sensing applications. The concave cubic morphology has shown a remarkable plasmonic response, representing high sensitivity to the concavity degree. hence they can provide strong Raman signal which can be use in Raman imaging. Magnetic resonance and optical imaging are complementary techniques. By applying same nanoparticles as a contrast agent for both methods simultaniusly, screening total body with very clear identification become possible. This progress in imaging technologies associated with the advance of nanotechnology makes feasible the cancer detection and localization in its early stage.
An innovative class of MRI CAs is represented by Gd-loaded gold nanoparticles. Differently from other nano-sized systems, the size, shape and chemical functionalization appear to affect the observed relaxation enhancement of water protons in their suspensions. The herein reported results shed more light on the determinants of the relaxation enhancement brought by Gd-loaded concave cube gold nanoparticles. It has been found that the role of the concave surface of these nanoparticles in the relaxivity is remarkable and it provides high contribution of second sphere water molecules. The specific shape of concave cube nanoparticles increases the relaxivity from 20.9 mM-1S-1 for spherical nanoparticles to 36.3 mM-1S-1. On the other hand, our studies prove that this special shape gold nanoparticles show high efficiency as a SERS probe. In the single-particle surface-enhanced Raman spectroscopy, the use of tunable plasmonic nanoparticles, having tipped surface structures, as being substrates revealed a highly feasible and promising approach to optimize SERS-based imaging and sensing applications. The concave cubic morphology has shown a remarkable plasmonic response, representing high sensitivity to the concavity degree. hence they can provide strong Raman signal which can be use in Raman imaging. Magnetic resonance and optical imaging are complementary techniques. By applying same nanoparticles as a contrast agent for both methods simultaniusly, screening total body with very clear identification become possible. This progress in imaging technologies associated with the advance of nanotechnology makes feasible the cancer detection and localization in its early stage.

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Dalveren, Taylan. "A Study of Sensitivity Mapping Techniques for Multi-Channel MR Coils". University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1373403690.

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Hoang, Minh Dung. "Instrumentation and technical development for small animal micro-MRI studies at 7-Tesla". Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10284.

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L'IRM offre de nombreux avantages qui en font un outil d'imagerie attractif en comparaison avec d'autres modalités d'imagerie préclinique complémentaires telles que l'imagerie optique, la micro-tomographie aux rayons X (μ-scanner ou μ-CT), la micro- Tomographie par Emission de Positons (μ-TEP), l'échographie ultrasonore ou l'imagerie par photoluminescence et fluorescence. La nature tridimensionnelle de l'IRM sur une grande région d'intérêt en combinaison avec un contraste endogène tissulaire inégalé et qui est réalisable avec une résolution micrométrique en font un outil d'imagerie de haute importance en recherche biomédicale et plus particulièrement si l'on tient compte de la diversité des sources de contraste tissulaire possibles. Cependant, la principale limitation de lIRM reste sa sensibilité relativement faible et sa productivité réduite à un seul examen à la fois. L'objectif principal de ce travail de thèse a été le développement d'un ensemble de méthodologies en Imagerie par Résonance Magnétique (IRM), dédiées à des études sur des modèles expérimentaux. Une grande partie de nos efforts a été consacrée aux travaux suivants:-au développement et à l'optimisation d'instrumentations dédiées,-à la mise en place de protocoles IRM efficaces, L'ensemble de nos travaux a visé à surmonter tant les contraintes expérimentales rencontrées que celles liées a notre installation IRM. Particulièrement, l'amélioration d'images ex vivo et in vivo a été obtenu lors d'études précliniques utilisant des modèles animaux de la maladie d'Alzheimer. Les résultats obtenus ont été atteints logiquement et progressivement à partir d'expérimentations ex vivo et in vivo. La première étape a été consacré à l'amélioration de la composante clé en amont de la chaîne d'acquisition: la sonde RMN, également appelée résonateur radiofréquence (RF). Nous avons mené notre travail sur les trois aspects expérimentaux suivants: Conception et réalisation de sondes dédiées à l'imagerie in vivo de la souris tant pour l'étude du corps entier que pour l'IRM de la tête, - Développement et mise en oeuvre de sondes et d'instrumentation permettant l'acquisition simultanée de plusieurs cerveaux de souris ex vivo afin d'augmenter la productivité et l'efficacité de notre scanner, -Conception et réalisation d'un ensemble d'antennes spécialement adapté à l'imagerie directe de coupes de tissues histologiques de différentes tailles ainsi qu'a la mise au point des protocoles correspondants à la préparation des échantillons. Dans le chapitre d'introduction (chapitre 1), nous décrivons l'ensemble des outils et protocoles de caractérisation des sondes RMN conçues et réalisées pour les besoins de nos études. Cette caractérisation systématique effectuée aussi pour les antennes RMN commerciales du laboratoire a permis d'établir une étude comparative de leurs performances. Dans le chapitre 2, nous avons étudié des résonateurs RF homogènes avec une attention particulière pour les résonateurs de type cage d'oiseau. Après examen de leurs principaux avantages et des limites de chaque structure (passe-bas et passe-haut), nous détaillons les étapes pratiques nécessaires pour concevoir une antenne cage d'oiseau de type passe-haut dédiée à l'imagerie corps entier de souris. A titre d'exemple, nous présentons des séries d'images par IRM, illustrant l'excellente couverture RF et permettant l'identification (dans notre cas, de façon qualitative) des propriétés pharmacocinétiques d'agents de contraste nouvellement conçus [etc...]
The overarching goals of this work are to develop a set of magnetic resonance (MR) imaging methodologies to help study experimental models in the biomedical research. MRI offers a combination of attributes making it appealing as an imaging tool in biomedical research compared to other complementary preclinical imaging modalities such as optical imaging, micro-computed tomography, micro-Positron emission tomography or ultrasound bio-microscopy. The three-dimensional nature of MRI over a large region of interest and the unrivaled endogenous tissue contrast achievable in micrometric resolution make it a very important tool in biomedical research. This is particularly important with the expanding potentials of tissue contrast mechanism it can offer. However, one of the major limitations is its relative low sensitivity and slow throughput. A large part of our efforts have been dedicated to improve the MRI instrumentation and protocols to overcome some of these limitations around the existing MRI scanner in order help better screen both in vivo and ex vivo transgenic mouse models, -the most studied animal model of human diseases. This was assessed in our work with a particular focus on experimental models of Alzheimer’s disease.The description of our work and results build logically and incrementally from in vivo to ex vivo experimental set up starting with tackling the improvement of the first component of the acquisition chain: the MRI probe, also termed radiofrequency (RF) resonator or coil. The scope of the work expands from probes enabling in vivo whole mouse body to headonlyMRI as well as multiple ex vivo sample imaging in order to achieve higher throughput to dedicated instrumentation and set up for direct MR imaging of histology sections. In the introductory chapter (Chapter 1), we describe the set of tools and protocol that enable the characterization of each MRI probe used in our study. The systematic characterization for both existing commercial MRI coils and the one we develop in-house during this work allow for direct comparison of their performance. In chapter 2, we investigate the homogeneous RF resonators dedicated for in vivo studies with a particular focus on birdcage resonators. After examining the main advantages and limitations between low and high pass structures, we introduce the practical steps required to design a high pass birdcage structure aimed at whole mouse body imaging. Examples of serial imaging illustrate the excellent RF coverage of the whole mouse body in order to screen qualitatively the pharmacokinetic properties of newly designed contrast agents. For mouse head imaging, we aimed to increase the coil sensitivity relative to an existing commercial coil by reducing the geometry structure to closely fit the region of interest. The resulting gain in filling factor achieved without compromising the overall homogeneity of the RF field covering the brain region lead to 10% gain in Signal-to- Noise Ratio (SNR) or an equivalent 20% reduction in imaging time [etc...]

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Zimmeter, Katharina. "Développement de sondes IRM à base de peptides ou thiosemicarbazones pour la détection de cuivre(II) dans le milieu physiologique". Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAF046.

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Le cuivre échangeable, principalement lié à l'albumine sérique humaine (HSA) dans le sang, est un biomarqueur potentiel pour des maladies comme celles de Wilson et d’Alzheimer. Aucune méthode spécifique pour le détecter in vivo n'existant à ce jour, cette thèse présente des avancées dans la conception de sondes IRM (imagerie par résonance magnétique) responsives au CuII via deux approches : les agents de contraste (AC) de type q et τR, intégrant chacun un complexe de gadolinium et un ligand spécifique du CuII. Une partie de la thèse est dédiée à la synthèse et à l’étude de ligands adaptés à ces deux approches avec une affinité et une sélectivité suffisantes pour le CuII : des dérivés du motif peptidique ATCUN pour les sondes de type q et des α-pyridyl-thiosemicarbazones pour les sondes de type τR. L'autre partie porte sur leur association avec des agents IRM et leur caractérisation. Les sondes étudiées ont validé le principe des deux approches, bien que des optimisations restent nécessaires. Une relaxivité accrue de presque 400% a été observée pour l'AC de type q, DO3A-pyrGH, en présence de CuII, et une augmentation faible, mais notable pour les sondes τR en présence simultanée de CuII et de HSA
Exchangeable copper, which is primarily bound to human serum albumin (HSA) in the blood, is a potential biomarker for diseases such as Wilson's and Alzheimer's. To date, there is no specific method for its detection in vivo. This thesis presents progress in the design of CuII-responsive MRI (magnetic resonance imaging) probes through two approaches: q-based and τR-based contrast agents (CAs), each containing a gadolinium complex and a CuII-specific ligand. One part of the work is dedicated to the development of ligands adapted to these two approaches, with sufficient CuII-affinity and selectivity: derivatives of the peptidic ATCUN motif for q-based probes and α-pyridyl thiosemicarbazones for τR-based probes. The other part focuses on their incorporation into MRI CAs and their characterization. The probes studied proved the principle of both approaches, although optimizations are still needed. An increase in relaxivity of nearly 400% was observed for the q-based CA, DO3A-pyrGH, in the presence of CuII, and a small but notable increase for τR-type probes in the simultaneous presence of CuII and HSA

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Chalmers, Kirsten Hardie. "Fluorinated paramagnetic probes for 19-F and 1-H MRS/MRI". Thesis, Durham University, 2011. http://etheses.dur.ac.uk/879/.

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Novel CF3-labelled lanthanide(III) complexes have been synthesised for use as probes for 19-F and 1-H magnetic resonance spectroscopy and imaging. The syntheses and evaluation of two classes of fluorinated paramagnetic complexes are defined. Notably, the 19-F magnetic resonance relaxation processes for the complexes have been assessed, allowing for the analysis of the interplay between applied field, Ln(III) ion and rotational correlation time on relaxation properties. Strategies employed to enhance signal intensity are discussed, examining a number of different of fluorinated mono- and di-amide cyclen ligands. Systems incorporating phosphinate pendant arms are of particular interest, resulting in complexes with favourable isomer distributions, faster longitudinal relaxation rates and narrower linewidths. Finally, the synthesis of high molecular weight conjugates with paramagnetic fluorinated complexes is described. Three different classes of medium to high molecular adducts were considered, with the merits and limitations of each assessed. The desirable formation of one species in solution, ease of solubility and attractive 19F and 1H relaxometric properties render the chitosan conjugates promising candidates for future use as imaging probes.

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Leung, Ho-hon Arthur, e 梁浩瀚. "Lanthanide complexes for magnetic resonance imaging (MRI) contrast agents and fluorescence probes". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47752774.

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In this work, novel Gd(III) complexes endowed with non-steroidal anti-inflammatory drugs (NSAIDs) were synthesised and their targeting properties towards sites of inflammation were studied in U87 xenograft and rheumatoid arthritis animal models. The Tb(III) analogues were also synthesised and their photophysical properties were studied. Six new Gd(III) DO3A-amide complexes bearing different linkers, ethylenediamine (GdL1), hexamethylenediamine (GdL2), 2,2’-oxydiethylamine (GdL3), 4,7,10-trioxa-1,13-tridecanediamine (GdL4), trans-1,4-cyclohexanediamine (GdL5), and 1,4-phenylenediamine (GdL6) were incorporated to mefenamic acid (MA) moiety, a common NSAID. The syntheses, relaxometric properties by NMR techniques, hydration number determinations by luminescence lifetime measurements, lipophilicities by UV-Vis spectrometry, serum albumin binding properties by tryptophan emission-quenching experiments, cytotoxicities by MTT assay, cellular uptake properties; MRI scans on U87 sxenograft and rheumatoid arthritis animal models, and biodistributions of these new complexes were discussed. GdL1-L6 possess one bound water molecule and GdL2-L5 show higher relaxivities than Gd-DOTA (4.21 mM?1s?1, 300 MHz, 25oC), a clinically used MRI contrast agent (CA). The relaxivities at 300 and 400 MHz respectively at 25oC are in the descending order of GdL4 (5.70 and 4.87 mM?1?1) > GdL3 (4.94 and 4.07 mM?1s?1) > GdL2 (4.60 and 4.07 mM?1s?1) > GdL5 (4.41 and 4.12 mM?1s?1) > GdL6 (3.98 and 3.31 mM?1s?1) > GdL1 (3.96 and 3.56 mM?1s?1). GdL1-L5 show low cytotoxicities towards HeLa cells at 1000 μM. The MRI scans of GdL1-L6 on U87 xenograft show strong intensity boost immediately after administration. The intensity enhancements persist for more than 90 mins and complete clearances are found after 24 h post-administration. Their MRI scans on arthritis model also show prolonged retention. It is concluded that the retention is related to the targeting on inflammatory mediators of the complexes. All complexes show superior retention and intensity enhancements in kidney, liver, tumour and arthritis joint than Gd-DOTA. GdL1-L6 are therefore potential candidates as universal MRI CAs. Three new Gd(III) DO3A-amide complexes bearing respectively benzoic acid (GdL7), salicylic acid (GdL8), and methylated salicylic acid (GdL9), one known Gd(III) DTPA-bissalicylic acid (GdL10) complex and one new Gd(III) DTPA-bismethylated salicylic acid (GdL11) were synthesised and investigated. Their syntheses, relaxivities, hydration numbers, pH dependent photophysical properties, cytotoxicities, cellular uptake properties and MRI scans on arthritis rat model were discussed. All GaL7-L11 possess one bound water molecule and show lower relaxivities than Gd-DOTA. The relaxivities at 300 MHz at 25oC are in the descending order of GdL10 (3.64 mM?1s?1) > GdL9 (3.53 mM?1s?1) > GdL11 (2.69 mM?1s?1) > GdL8 (2.10 mM?1s?1) > GdL7 (1.99 mM?1s?1). Their Tb(III) analogue (TbL7-L11) show pH dependent UV-Vis and photoluminescence spectra which are consequences of protonation or deprotonation of the carboxylic acid, hydroxyl and amide groups. It is concluded that the pH change alters energy transfer efficiency and the ligand triplet energy level. GdL7-L11 show low cytotoxicities in MTT assay. Specifically, GdL8 is examined on arthritis rat model to give a comparable intensity at the arthritis joint to Gd-DOTA but having a longer retention time. LnL8 has therefore demonstrated its potential as both a MRI CA to target inflammation sites and a pH dependent luminescence probe.
published_or_final_version
Chemistry
Doctoral
Doctor of Philosophy

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Adhitiyawarman. "Pyridyltriazole-containing compounds as sinc-responsive MRI contrast agents and luminescence probes". Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/43041.

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Magnetic resonance imaging (MRI) is a versatile imaging modality in modern clinical applications. The use of MRI started to be more powerful since the invention of smart contrast agents, which can selectively respond to a specific stimulus such as a metal ion. This study was focused on GdDO3A-based complexes designed to be zinc-responsive MRI contrast agents by exploiting a new pyridyltriazole moiety as an active arm for a zinc(II) chelator. This active arm was designed to have a coordination displacement ability to give a switch-on MR signal. A series of pyridyltriazole containing compounds were synthesized and examined sequentially. The primary compound containing pyrydyltriazole LnC2 (q = 0) exhibited no response towards zinc(II). Modification by changing the binding orientation of the pyridyltriazole, LnC4 had reduced the steric hindrance allowing one coordination site for water (q = 1); however, it still did not show any change in signal to the presence of zinc(II). Increasing the distance between the active arm and the lanthanide centre via additional carbon linkers (LnC5 and LnC6) gave complexes an open-structure (q = 2). This structure also had low affinity toward zinc(II) and did not provide a switch on response to the MR signal. Addition of a hydroxyl functional group to the pyridyltriazole (LnC7) did not change its coordination mode (q = 2). Incorporation of a carboxylic acid group (LnC8) provided coordination to give a q = 1 complex. Furthermore, it exhibited coordination displacement in response to zinc(II), by modulating its hydration number to give a "switch on" MR signal; the relaxivity increased by 30% from 6.5 to 8.6 mM-1s-1 as a response to one equivalent of zinc(II). Elongation of the linker by replacing it with the tri- and tetra-ethylene glycol (LnC9 and LnC10) changed their relaxivity in response to zinc(II) which was assumed to be a result of a different coordination mode. A series of emissive lanthanide complexes with high fluorescence quantum yields were also synthesized as luminescence probes namely; a click-ready complex (TbC1), water soluble complexes (TbC2a, TbC2b), a polymerizable complex (TbC2c), a dimer complex (TbC2-dimer), tridentate ligand complexes (Tb/Eu(27)3, Tb/Eu(32b)3) and a complex potential for dual-modal fluorescence/MR imaging probe (Tb(GdC8)3).

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Livros sobre o assunto "MRI probe"

Xiao, Yun. Fu qin de mai di: Xiyu mei nü de qing gan mei wen. Wulumuqi: Xinjiang ren min chu ban she, 2002.

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Isakov, Ben. Mir, shagi, sozvuchii︠a︡. New York: [publisher not identified], 2013.

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A, Gracheva L., e Polesterov I︠A︡ I︠U︡, eds. I pomnit mir spasennyĭ, mir vechnyĭ, mir zhivoĭ--. Moskva: Profizdat, 2005.

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Pingwa, Jia, ed. Da jia mei wen. Beijing: Beijing shi yue wen yi chu ban she, 2003.

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Philippe, Lejeune. Moi aussi. Paris: Seuil, 1986.

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Gao, Jian, e Xiaodan Yu. Mei gui shu. Beijing: Zhongguo she hui ke xue chu ban she, 1993.

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Skalon, N. R. Veshchʹ i slovo: Predmetnyĭ mir v sovetskoĭ filosofskoĭ proze. Alma-Ata: "Gylym", 1991.

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Beniak, Edouard. Ma muse à moi, Montréal: Poésie et prose illustrées. Montréal: Lanctôt, 2007.

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Chen, Min, e Chu Sun. Qi di Zhongguo qing nian de100 pian ren sheng mei wen. Beijing: Zhongguo guang bo dian shi chu ban she, 2007.

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Fedorov, G. I. Khudozhestvennyĭ mir chuvashskoĭ prozy 1950-1990-kh godov. Cheboksary: Chuvashskiĭ gos. in-t gumanitarnykh nauk, 1996.

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Capítulos de livros sobre o assunto "MRI probe"

Ariando, David J., e Soumyajit Mandal. "Coils and Probe Circuits". In Portable Low-Field MRI Scanners, 57–111. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-60230-6_4.

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Ganepola, Tara, Zoltan Nagy, Daniel C. Alexander e Martin I. Sereno. "An Unsupervised Group Average Cortical Parcellation Using Diffusion MRI to Probe Cytoarchitecture". In Computational Diffusion MRI, 145–56. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-54130-3_12.

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Pizzolato, Marco, Demian Wassermann, Tanguy Duval, Jennifer S. W. Campbell, Timothé Boutelier, Julien Cohen-Adad e Rachid Deriche. "A Temperature Phantom to Probe the Ensemble Average Propagator Asymmetry: An In-Silico Study". In Computational Diffusion MRI, 183–94. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-28588-7_16.

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Jallais, Maëliss, e Demian Wassermann. "Single Encoding Diffusion MRI: A Probe to Brain Anisotropy". In Mathematics and Visualization, 171–91. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-56215-1_8.

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AbstractThis chapter covers anisotropy in the context of probing microstructure of the human brain using single encoded diffusion MRI. We will start by illustrating how diffusion MRI is a perfectly adapted technique to measure anisotropy in the human brain using water motion, followed by a biological presentation of human brain. The non-invasive imaging technique based on water motions known as diffusion MRI will be further presented, along with the difficulties that come with it. Within this context, we will first review and discuss methods based on signal representation that enable us to get an insight into microstructure anisotropy. We will then outline methods based on modeling, which are state-of-the-art methods to get parameter estimations of the human brain tissue.

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Pham, Wellington. "Principles for the Design of MRI Probes". In Principles of Molecular Probe Design and Applications, 147–99. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-5739-0_4.

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von Morze, Cornelius, Galen D. Reed, Zhen J. Wang, Michael A. Ohliger e Christoffer Laustsen. "Hyperpolarized Carbon (13C) MRI of the Kidneys: Basic Concept". In Methods in Molecular Biology, 267–78. New York, NY: Springer US, 2021. http://dx.doi.org/10.1007/978-1-0716-0978-1_16.

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AbstractExisting clinical markers for renal disease are limited. Hyperpolarized (HP) 13C MRI is based on the technology of dissolution dynamic nuclear polarization (DNP) and provides new avenues for imaging kidney structure, function, and most notably, renal metabolism, addressing some of these prior limitations. Changes in kidney structure and function associated with kidney disease can be evaluated using [13C]urea, a metabolically inert tracer. Metabolic changes can be assessed using [1-13C]pyruvate and a range of other rapidly metabolized small molecules, which mainly probe central carbon metabolism. Results from numerous preclinical studies using a variety of these probes demonstrated that this approach holds great potential for monitoring renal disease, although more work is needed to bridge intelligently into clinical studies. Here we introduce the general concept of HP 13C MRI and review the most relevant probes and applications to renal disease, including kidney cancer, diabetic nephropathy and ischemic kidney injury.This chapter is based upon work from the PARENCHIMA COST Action, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

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Kretschmer, Jan, Juan Pellico, Angelina Prytula-Kurkunova, Rafael Torres Martin De Rosales e Andre Ferreira Martins. "Advances in PET/MRI and Probe Development for Biomedical Precision Imaging Applications". In Lanthanide and Other Transition Metal Ion Complexes and Nanoparticles in Magnetic Resonance Imaging, 367–98. Boca Raton: CRC Press, 2024. http://dx.doi.org/10.1201/9781003374688-12.

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Gobbi, David G., Roch M. Comeau e Terry M. Peters. "Ultrasound Probe Tracking for Real-Time Ultrasound/MRI Overlay and Visualization of Brain Shift". In Medical Image Computing and Computer-Assisted Intervention – MICCAI’99, 920–27. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/10704282_100.

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Laurent, Sophie, Céline Henoumont, Dimitri Stanicki, Sébastien Boutry, Estelle Lipani, Sarah Belaid, Robert N. Muller e Luce Vander Elst. "Imaging Probes". In MRI Contrast Agents, 13–21. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-2529-7_3.

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Morrow, Janet R., e Sarina J. Dorazio. "Direct Excitation Ln(III) Luminescence Spectroscopy to Probe the Coordination Sphere of Ln(III) Catalysts, Optical Sensors and MRI Agents". In Luminescence of Lanthanide Ions in Coordination Compounds and Nanomaterials, 303–30. Chichester, United Kingdom: John Wiley & Sons Ltd, 2014. http://dx.doi.org/10.1002/9781118682760.ch08.

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Trabalhos de conferências sobre o assunto "MRI probe"

Akram, Mohammad Makhdoumi, Farshid Shateri, Abdolkhalegh Mohammadi, Alireza Geravand, Wei Shi e Benoit Gosselin. "Implantable Neural Probe with Thermo-Optic Switches Based on Multimode Interference (MMI) in Thermogenetic Application". In 2024 22nd IEEE Interregional NEWCAS Conference (NEWCAS), 148–52. IEEE, 2024. http://dx.doi.org/10.1109/newcas58973.2024.10666322.

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Jia, Ziqi, Paritosh Rustogi, Jack Judy e Yong-Kyu Yoon. "MRI COMPATIBLE MULTIFUNCTIONAL CARBON NANOFIBER NEURAL PROBE". In 2022 Solid-State, Actuators, and Microsystems Workshop. San Diego: Transducer Research Foundation, 2022. http://dx.doi.org/10.31438/trf.hh2022.58.

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Larson, Blake T., Arthur G. Erdman e Nikolaos V. Tsekos. "An MRI-Compatible Probe Exchanger for Early Diagnosis and Treatment of Breast Cancer". In ASME 2004 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/detc2004-57047.

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The objective of this project is to develop a device to exchange interventional probes such as biopsy needles, local anesthesia, ablation tools, and lesion removal devices to perform multiple procedures for breast cancer diagnosis and treatment during single session in the MR scanner. Used as a supplement to an existing five degree-of-freedom (DOF) interventional probe positioning device, the apparatus is fitted with two additional DOF for the selection and exchange of interventional probes to be used in an automated probe positioning device. The entire system is constructed of MR compatible materials, i.e. non-magnetic and non-conductive, to eliminate artifacts and distortion of the MR images. The apparatus is remotely controlled by means of ultrasonic piezoelectric motors and a graphical user interface, providing MRI-guided planning and monitoring of the procedure while it is in progress. Based on a timing analysis, the device can quickly exchange a probe (48 seconds), thereby reducing the complexity and cost of the overall procedure.

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Liu, Xinyang, Kemal Tuncali, William M. Wells e Gary P. Zientara. "Automatic probe artifact detection in MRI-guided cryoablation". In SPIE Medical Imaging, editado por David R. Holmes e Ziv R. Yaniv. SPIE, 2013. http://dx.doi.org/10.1117/12.2008530.

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Wu, Faye Y., Meysam Torabi, Atsushi Yamada, Alex Golden, Gregory S. Fischer, Kemal Tuncali, Dan D. Frey e Conor Walsh. "An MRI Coil-Mounted Multi-Probe Robotic Positioner for Cryoablation". In ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/detc2013-13132.

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Cryoablation is a percutaneous procedure for treating solid tumors using needle-like instruments. This paper presents an interventional guidance device for faster and more accurate alignment and insertion of multiple probes during cryoablation performed in closed bore magnetic resonance (MR) imaging systems. The device is compact and is intended to be mounted onto a Siemens 110 mm MR loop coil. A cable-driven two-degrees-of-freedom spherical mechanism mimics the wrist motion as it orients the intervention probes about a remote center of motion located 15 mm above the skin. A carriage interfaces with the probes via a thumbscrew-fastened latch to passively release the probes from their tracks, enabling them to be inserted sequentially and freeing them to move with respiration. Small actuator modules containing piezoelectric encoder-based motors are designed to be snap-fit into the device for ease of replacement and sterilization. The robot MRI compatibility was validated with standard cryoablation imaging sequences in 3T MR environment, yielding a maximum of 4% signal to noise ratio during actuator motion. Bench-level device characterization demonstrated a maximum error of 0.78° in the carriage movement. Needle-tip placement experiments for multiple targets in gelatin were performed using our image-guided navigation software, measuring an average targeting error of 2.0 mm.

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Seifi, Bahram, Elena Semouchkina, Warren Perger, Gang Chea Lee, Thomas Neuberger e Michael Lanagan. "Modified design of the coil probe for high field MRI". In 2015 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting. IEEE, 2015. http://dx.doi.org/10.1109/aps.2015.7305066.

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Schell, J. B., J. B. Kammerer, L. Hebrard, D. Gounot, E. Breton, L. Cuvillon e M. de Mathelin. "3T MRI scanner magnetic gradient mapping using a 3D Hall probe". In 2012 IEEE Sensors. IEEE, 2012. http://dx.doi.org/10.1109/icsens.2012.6411080.

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Schell, J. B., J. B. Kammerer, L. Hebrard, E. Breton, D. Gounot, L. Cuvillon e M. de Mathelin. "CMOS 3D Hall probe for magnetic field measurement in MRI scanner". In 2012 IEEE 10th International New Circuits and Systems Conference (NEWCAS). IEEE, 2012. http://dx.doi.org/10.1109/newcas.2012.6329070.

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"AUTOMATIC DEACTIVATION DESIGN FOR PHASED ARRAY SURFACE PROBE IN 1.5T MRI". In International Conference on Biomedical Electronics and Devices. SciTePress - Science and and Technology Publications, 2008. http://dx.doi.org/10.5220/0001050501600163.

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Cruttenden, Corey, Mahdi Ahmadi, Xiao-Hong Zhu, Wei Chen e Rajesh Rajamani. "An MRI Compatible Brain Probe for Signal Recording and Deep Brain Stimulation". In 2018 Design of Medical Devices Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/dmd2018-6951.

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Electrical stimulation of neural tissue is a promising therapy for a variety of neurological diseases. For example, electrical stimulation of deep thalamic nuclei has been used extensively to treat symptoms of Parkinson’s disease, and there is growing interest in treating other conditions including epilepsy and depression with similar techniques. However, the mechanisms of electrical brain stimulation for disease therapy are not fully understood [1].

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Relatórios de organizações sobre o assunto "MRI probe"

Sun, Xiankai. PSMA-Targeted Nano-Conjugates as Dual-Modality (MRI/PET) Imaging Probes for the Noninvasive Detection of Prostate Cancer. Fort Belvoir, VA: Defense Technical Information Center, outubro de 2006. http://dx.doi.org/10.21236/ada463857.

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Sun, Xiankai. PSMA-Targeted Nano-Conjugates as Dual-Modality (MRI/PET) Imaging Probes for the Non-Invasive Detection of Prostate Cancer. Fort Belvoir, VA: Defense Technical Information Center, outubro de 2008. http://dx.doi.org/10.21236/ada493649.

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Sun, Xiankai. PSMA-Targeted Nano-Conjugates as Dual-Modality (MRI/PET) Imaging Probes for the Non-Invasive Detection of Prostate Cancer. Fort Belvoir, VA: Defense Technical Information Center, janeiro de 2010. http://dx.doi.org/10.21236/ada519262.

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Briggs, Richard W. Abnormalities in Human Brain Creatine Metabolism in Gulf War Illness Probed with MRS. Fort Belvoir, VA: Defense Technical Information Center, outubro de 2013. http://dx.doi.org/10.21236/ada589864.

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Briggs, Richard W. Abnormalities in Human Brain Creatine Metabolism in Gulf War Illness Probed with MRS. Fort Belvoir, VA: Defense Technical Information Center, dezembro de 2014. http://dx.doi.org/10.21236/ada622274.

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Levisohn, Sharon, Mark Jackwood e Stanley Kleven. New Approaches for Detection of Mycoplasma iowae Infection in Turkeys. United States Department of Agriculture, fevereiro de 1995. http://dx.doi.org/10.32747/1995.7612834.bard.

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Mycoplasma iowae (Mi) is a pathogenic avian mycoplasma which causes mortality in turkey embryos and as such has clinical and economic significance for the turkey breeder industry. Control of Mi infection is severely hampered by lack of adequate diagnostic tests, together with resistance to most antibiotics and resilience to environment. A markedly high degree of intra-species antigenic variation also contributes to difficulties in detection and control of infection. In this project we have designed an innovative gene-based diagnostic test based on specific amplification of the 16S rRNA gene of Mi. This reaction, designed Multi-species PCR-RFLP test, also amplifies the DNA of the pathogenic avian mycoplasmas M. gallisepticum (Mg) and M. synoviae (Ms). This test detects DNA equivalent to about 300 cfu Mi or either of the other two target mycoplasmas, individually or in mixed infection. It is a quick test, applicable to a wide variety of clinical samples, such as allantoic fluid or tracheal or cloacal swab suspensions. Differential diagnosis is carried out by gel electro-phoresis of the PCR amplicon digested with selected restriction enzymes (Restriction Fragment Length Polymorphism). This can also be readily accomplished by using a simple Dot-Blot hybridization assay with digoxigenin-labeled oligonucleotide probes reacting specifically with unique Mi, Mg or Ms sequences in the PCR amplicon. The PCR/OLIGO test increased sensitivity by at least 10-fold with a capacity for rapid testing of large numbers of samples. Experimental infection trials were carried out to evaluate the diagnostic tools and to study pathogenesis of Mi infection. Field studies and experimental infection of embryonated eggs indicated both synergistic and competitive interaction of mycoplasma pathogens in mixed infection. The value of the PCR diagnostic tests for following the time course of egg transmission was shown. A workable serological test (Dot Immunobinding Assay) was also developed but there was no clear-cut evidence that infected turkeys develop an immune response. Typing of a wide spectrum of Mi field isolates by a variety of gene-based molecular techniques indicated a higher degree of genetic homogeneity than predicted on the basis of the phenotypic variability. All known strains of Mi were detected by the method developed. Together with an M. meleagridis-PCR test based on the same gene, the Multi-species PCR test is a highly valuable tool for diagnosis of pathogenic mycoplasmas in single or mixed infection. The further application of this rapid and specific test as a part of Mi and overall mycoplasma control programs will be dependent on developments in the turkey industry.

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Deschamps, Henschel e Robert. PR-420-123712-R01 Lateral Ground Movement Detection Capabilities Derived from Synthetic Aperture Radar. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), novembro de 2014. http://dx.doi.org/10.55274/r0010831.

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The objective of this research was to quantify long-term ground deformation at the Belridge Oil Field, in the San Joaquin Valley (SJV), California using operational Interferometric Synthetic Aperture Radar (InSAR) monitoring techniques. A high spatial and temporal resolution, millimeter-precision time-series of ground deformation measurements was produced for the entire oil field from 2000 to 2012 using imagery from multiple satellites and beam modes. Trihedral Corner Reflectors (CRs) with co-located Global Navigation Satellite System (GNSS) units were used to validate the wide-area measurements along a section of Southern California Gas Company (SoCalGas) Line 7056. The GNSS measurements were also used to validate the precision of the InSAR measurements, and to determine what component of the overall motion was lateral motion. Deformation profiles over Lines 1203 were analyzed to identify periods of rapid deformation related to known pipeline incidents. Finally, we also investigated the use Multiple Aperture Interferometry (MAI) for measuring horizontal motion in the alongtrack (north-south) direction. The result is a detailed, seamless, long-term, validated time-series of ground change observations that could prove useful for further analysis of reservoir changes. Combined with injection and production data, the results may be used to extend an understanding of the geomechanics of Enhanced Oil Recovery (EOR) fields. This work reinforces the operational capability of InSAR for monitoring both EOR reservoir dynamics and deformation over buried pipelines.

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Bracewell, Jef. Coastal topography change at Gulf Islands National Seashore, Texas: 2018–2021 data summary. National Park Service, maio de 2022. http://dx.doi.org/10.36967/nrds-2293377.

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In the spring of 2018 and 2021, the Gulf Coast Network collected coastal topography data at Gulf Islands National Seashore as a part of the NPS Vital Signs Monitoring Program. Monitoring was conducted following methods detailed in Monitoring Coastal Topography at Gulf Coast Network Parks: Protocol Implementation Plan (PIP; Bracewell 2017). Key findings from this effort are as follows: In Florida, the Perdido Key unit showed higher losses in profile area as well as retreat in dune crest and shoreline position than in the Fort Pickens unit. Because of unfavorable weather conditions and a compressed survey window, six of 16 transects in Mississippi were not surveyed in 2021. The highest rates of loss in profile area on Horn Island were at the western end. Three pilot monitoring transects were added in 2021 at Fort Pickens area, updrift, or east of the Gulf Coast Network's established effort. This expands survey coverage about 3 kilometers (1.9 miles [mi]) and incorporates a portion of the narrower, washover-prone section of the unit. This project is in the early phases of implementation and will benefit from future surveys to better understand the influence of slight changes in survey timing and other environmental variations.

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Bracewell, Jeff. Coastal topography change at Gulf Islands National Seashore, Florida and Mississippi: 2018–2021 data summary—version 1.1. National Park Service, agosto de 2022. http://dx.doi.org/10.36967/2293995.

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