Teses / dissertações sobre o tema "18F-TEP"
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Hovhannisyan, Narinée. "[18F] Fludarabine pour l'imagerie TEP des lymphomes". Thesis, Normandie, 2018. http://www.theses.fr/2018NORMC412/document.
Texto completo da fonteAlthough PET using [18F]FDG has proved to be useful for diagnosis and therapy monitoring in patients with lymphoma, the specificity of [18F]FDG uptake has been critically questioned because of its dependence on glucose metabolism, which may indiscriminately increase in benign conditions such as inflammatory or infectious processes. Considering these drawbacks, an adenine nucleoside analogue was developed as a novel PET imaging probe ([18F]fludarabine). An efficient and fully automated radiosynthesis has been implemented and, subsequently preclinical studies in xenograft murine models (follicular cell lines: RL7 and DOHH-2, multiple myeloma (MM): RPMI8226, central nervous system (CNS) lymphoma: MC116) were conducted with this novel 18F-radiopharmaceutical in parallel with [18F]FDG. The pattern of the radioactivity distribution in selected organs confirmed the tumor-specific targeting. In a follicular lymphoma model, we evaluated its robustness during rituximab therapy and demonstrated - the treatment did not interfere with its uptake - a stronger correlation between quantitative values extracted from this 18F-radiopharmaceutical and histology when compared to [18F]FDG-PET. Accordingly, this PET tool may be considered as a promising approach for detecting the persistence of residual disease during or after rituximab-like treatment. Furthermore, its behaviour in turpentine-induced inflammatory process showed significantly weaker uptake in inflammation when compared to [18F]FDG. In MM, the role of [18F]FDG-PET remains limited because of its lack of sensitivity for detecting diffuse bone marrow involvement, small skull lesions due to the physiological [18F]FDG uptake in brain. Our data suggested that [18F]fludarabine-PET might represent an alternative and perhaps more specific modality for MM imaging. In our latest study, on xenograft brain tumors, this novel PET probe revealed significantly divergent responses between CNS lymphoma and glioblastoma (GBM), while [18F]FDG demonstrated overlap between the groups. A first in man study, was undertaken, for an initial diagnosis, where 10 untreated patients were enrolled with either B-cell chronic lymphocytic leukemia (CLL) or diffuse large B-cell lymphoma (DLBCL). Successive partial body scans were acquired for 250 min after i.v. injection with an activity of 4 MBq/kg. The results with conventional modalities (CT and/or [18F]FDG-PET) have also been investigated. The study was also designed to estimate its radiation dose for major organs. In DLBCL patients, increased uptake was observed in sites considered abnormal by CT and [18F]FDG; in two patients discrepancies were observed in comparison with [18F]FDG. In CLL patients, the uptake coincided with sites expected to be involved and displayed a significant uptake in hematopoietic bone marrow. No uptake was observed, whatever the disease group, in the cardiac muscle and brain. Moreover, its mean effective dose was below the effective dose reported for [18F]FDG. In conclusion, these preclinical and clinical findings revealed a great specificity of this 18F-radiopharmaeutical for lymphoma tissues. Furthermore, it might well be a robust tool for correctly quantifying the disease, even with inflammatory processes, thus avoiding the false-positive results, and an innovative approach for imaging lymphoid neoplasms with low mitotic activity
Vanhoutte, Matthieu. "Caractérisation par imagerie TEP 18F-FDG de la maladie d’Alzheimer à début précoce". Thesis, Lille 2, 2018. http://www.theses.fr/2018LIL2S026/document.
Texto completo da fonteAlzheimer’s disease (AD) is the most common form of neurodegenerative dementia, characterized at 95% by late-onset forms (LOAD) which present episodic memory impairments and progress slowly. However, 5% of AD patients have an early-onset form (EOAD) of the disease whose onset begins before 65. Although the lesion substratum is similar between EOAD and LOAD, EOAD has more severe neuritic plaque deposits, neurofibrillary tangles and brain atrophy. Moreover, EOAD is more heterogeneous than LOAD, because even if most of the impairments are about episodic memory there is a high proportion of atypical forms impaired in language, visuospatial or executive functions. Although many 18F-FDG PET studies allowed to metabolically characterize EOAD compared to LOAD or healthy controls group, very few differentiated typical from atypical forms. In this thesis, we examined 18F-FDG PET data, complemented by structural MRI, in order to improve characterization and comprehension of typical and atypical forms of EOAD. Following a first harmonization work between 18F-FDG PET reconstructions from both GE and Siemens scanners used for the acquisition of patient data, our second aim was to study at baseline on the whole brain hypometabolic patterns characterizing the clinical forms of EOAD and their correlations with neuropsychological performance. This work showed that each clinical form of EOAD was characterized by specific hypometabolic patterns highly correlated with clinical symptoms and neuropsychological performance of the associated cognitive domain. Then, we focused on the 3-year hypometabolism progression on the cortical surface according typical or atypical forms of EOAD. Although similar patterns of hypometabolism evolution between typical and atypical forms were observed in parietal cortices, atypical only showed a more severe reduction of metabolism in lateral orbitofrontal cortices associated with more severe cognitive declines. Temporally, the results suggest that hypometabolism in typical forms would progress according to an anterior-to-posterior axis coherently with Braak and Braak stages, whereas in atypical forms hypometabolism would progress according a posterior-to-anterior axis. Taken together, results consolidate the hypothesis of a different tau distribution in terms of burden and temporal evolution between both forms of EOAD. Our last goal was to determine the discriminative power of 18F-FDG PET data, alone or combined to structural MRI data, in order to automatically classify in a supervised manner EOAD patients into typical or atypical form. We applied machine learning algorithms combined to cross-validation methods to assess influence of some components on classification performances. Maximum balanced accuracies equal to 80.8% in monomodal 18F-FDG PET and 92.4% in multimodal 18F-FDG PET/T1 MRI were obtained, validating 18F-FDG PET as a sensible biomarker of EOAD and highlighting the incontestable contribution of multimodality. In conclusion, our works allowed a better characterization and comprehension of clinical forms of EOAD, paving the way to personalized patient management and more effective treatments for these distinct clinical forms
Nioche, Christophe. "Caractérisation des tumeurs gliales en TEP/TDM à la 18F-Dopa et en IRM de perfusion". Thesis, Paris 11, 2011. http://www.theses.fr/2011PA112100.
Texto completo da fonteMRI provides morphological information about tumour, but also provides information regarding the micro-vascularization of the tumour. In PET/CT, the accumulation of 18F-FDopa in tumour cells results from the metabolic activity greater than that of healthy tissues. We studied 28 gliomas for which we analysed data from MRI and PET/CT. A registration method has been developed to combine information from both PET and MRI and to extract volumes of interest consistent with the information included in the two modalities. In these volumes, the tumour compartment and normal tissue compartment were identified using a Gaussian mixture model. Parameters from PET or MRI data were then calculated in these compartments. ROC analyses combined with linear discriminant analyses were used to assess whether joint observation of standardized uptake value (SUVmax ) and relative Cerebral Blood Volume (rCBV) or of relative rk1 and rCBV could distinguish between low grade and high grade tumours. We found that using this joint analysis, 82.4% of high-grade tumors and 70.0% of low-grade tumors were correctly classified (AUC of 0.88 for [SUVmax , rCBV] and of 0.92 for [rk1 , rCBV]). Considering the [SUVmax , rCBV] combined information, the sensitivity for detecting high-grade tumors was 95% with a specificity of 60%. The negative predictive value was 52% for a positive predictive value of 95%. Similarly, considering the [rk1 , rCBV] combined information, we also a specificity of 60% associated with a 95% sensitivity for detecting high-grade tumors, with a negative predictive value of 60% and positive predictive value of 95%. Our work shows that joint analysis of microvascular and metabolic information is possible by combining PET and MR imaging data. However, we found that, in our patient population, the microvascular information given by MR did not bring information more discriminating than the metabolic information derived from PET only
Palard, Xavier. "Quantification multiparamétrique par TEP à la 18F-Choline et IRM dans le cancer de la prostate". Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1B058.
Texto completo da fonteResearch question: Do the functional parameters derived by 18F-Choline (FCH) Positon Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) add informations to characterize the aggressiveness of prostate cancer? Objectives: The first objective of this work was (i) to enhance a potential link between quantitative parameters extracted by FCH PET and clinicopathological parameters in prostate cancer. Then, after this preliminary study, in order to optimize the quantification of the FCH influx with a kinetic analysis, the second objective was (ii) to optimize the exam protocol of the FCH PET early acquisition. Finally, the last objective was (iii) to enhance a potential link between quantitative parameters extracted by FCH PET and quantitative parameters extracted by multiparametric MRI in prostate cancer. Results: For the first step (i), we compared FCH PET quantitative parameters and clinicopathological parameters extracted from 61 patients referred to the nuclear medicine department to perform an FCH PET/ CT with newly histologically proven prostate cancer and before any treatment The FCH influx measured using kinetic analysis was higher for patients with a Gleason score ≥ 4+3 than for patients with a Gleason score < 4 + 3. Concerning the second step (ii), firstly, we compared the contrast to noise ratio of 77 prostatic cancer lesions at 5 minutes and 10 minutes post-injection in order to optimize the length of the early FCH PET acquisition. No significant difference was observed. Secondly, we sought to define an optimal time sampling of the early FCH PET acquisition comparing 7 different time samplings with a FCH influx as objective extracted from 37 prostatic cancer lesions. The 12x5”-8x30” time sampling was selected. For the last step of this work (iii), we compared FCH PET and multiparametric MRI quantitative parameters extracted from 14 prostatic cancer lesions. The FCH influx was moderately correlated to the vessel permeability measured by the volume transfert constant of gadolinium (r = 0.55). Conclusion: The FCH influx extracted from the early FCH PET acquisition using kinetic analysis seems to be linked to the tumoral differentiation of prostatic cancers. This FCH influx seems also linked to the vessel permeability. However, due to the moderate degree of correlation, these two imaging parameters reflect two different processes. To confirm the results obtained in this work, other studies are needed to enhance the role of the functional parameters derived by FCH PET and multiparametric MRI as biomarkers for prostate cancer
Rmeily-Haddad, Mireille. "Analyse temporelle de la fixation cérébrale du 18F-FDG en TEP : cartographies et application clinique potentielle". Amiens, 2009. http://www.theses.fr/2009AMIED009.
Texto completo da fonteVerdurand, Mathieu. "Vers l'imagerie TEP de la neurotransmission sérotoninergique dans la maladie d'Alzheimer : du radiotraceur au modèle animal". Phd thesis, Université Claude Bernard - Lyon I, 2008. http://tel.archives-ouvertes.fr/tel-00348975.
Texto completo da fonteUne première partie, méthodologique, a consisté à automatiser et à optimiser la radiosynthèse du [11C]PIB, un radiotraceur pouvant détecter l'accumulation des peptides amyloïdes dans le cerveau de patients atteints de la MA.
Dans une seconde partie, nous nous sommes intéressés à l'imagerie TEP de la neurotransmission sérotoninergique. Les antagonistes des récepteurs 5-HT6 ont démontré des propriétés procognitives et des études post-mortem ont montrées leur modification dans la MA. Cependant, aucun centre ne dispose encore d'un radiotraceur spécifique. Nous rapportons l'évaluation biologique d'un radiotraceur antagoniste des 5-HT6, le [18F]12ST05. D'autre part, une étude récente en imagerie TEP au [18F]MPPF, un antagoniste des récepteurs 5-HT1A, a révélé une diminution de sa fixation chez des patients Alzheimer alors qu'une augmentation pouvait être constatée chez des patients MCI. Nous sommes parvenus à reproduire une surexpression transitoire des 5-HT1A dans un modèle animal de la MA et nous proposons différents mécanismes compensatoires à l'origine de cette augmentation. Ces résultats apportent des hypothèses sur la nature des phénomènes compensatoires précoces stimulés et pourraient avoir des conséquences sur les thérapeutiques ciblant les 5-HT1A.
Didelot, Adrien. "Étude par la TEP au [18F]MPPF des récepteurs cérébraux sérotoninergiques 5-HT1A dans l’épilepsie du lobe temporal". Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10104/document.
Texto completo da fonteIn patients suffering from epilepsy, no neuroimaging method has proved able to delineate the epileptogenic zone (EZ), which is defined by the area of cortex required to generate the epileptic seizures. About one third of patient suffering from temporal lobe epilepsies (TLE) are not seizure free after surgery after removal of the cortical area supposed to included the EZ according to the presurgical evaluation. Data from previous studies carried out in our departement suggested that decreases of the [18F]MPPF binding potential (BPND) correlated, at the group level, with cortical epileptogenicity. Our aim was to validate the relevance of [18F]MPPF PET at the individual level for identifying the EZ in TLE. In a first study, the [18F]MPPF PET of 42 patients suffering from TLE were visually and statistically analyzed and compared with [18F]FDG PET, which were performed in the same group of patients during their presurgical evaluation. In a second study, we developed a voxel based analysis of asymmetry index (AI) of [18F]MPPF binding and compared the sensibility and specificity of this method to those of conventional SPM analysis of [18F]MPPF PET data. This second study was carried out in 24 patients, who have been operated and remained seizure-free after surgery. Two statistical thresholds (p< 0.05 corrected at the voxel level and p< 0.05 corrected at the cluster level) were used for each method. In a last study, the correlation between the depressive symptoms and the BPND of [18F]MPPF was studied in 24 patients suffering from TLE. These three studies lead to the following conclusions: i) [18F]MPPF PET is more performant than [18F]FDG PET for identifying the epileptogenic lobe in patients suffering from TLE, ii) AI analysis with a statistical threshold of p< 0.05 corrected at the cluster is the method of analysis of [18F]MPPF PET that allowed EZ identification with the best sensitivity [96%] and specificity [88%] in TLE, iii) at the group level, depressive symptoms positively correlate with an increase of the BPND of [18F]MPPF BPND within the raphe nuclei and the insula controlateral to the EZ
Didelot, Adrien. "Étude par la TEP au [18F]MPPF des récepteurs cérébraux sérotoninergiques 5-HT1A dans l'épilepsie du lobe temporal". Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00705810.
Texto completo da fonteAwde, Ali Reda. "Evaluation de la protéine translocatrice TSPO comme cible pour l’imagerie moléculaire et la thérapie du glioblastome dans un modèle expérimental chez le rat". Thesis, Paris 5, 2012. http://www.theses.fr/2012PA05P647.
Texto completo da fonteIn France alone, there are 3000 new cases of glioblastoma multiforme (GBM) per year and therefore GBM is the most common and aggressive form of the primary tumor in the central nervous system (CNS). The clinical prognosis for glioblastoma patients is extremely poor with a median survival period that rarely exceeds 15 months post-diagnosis. Since the study performed by Stupp and colleagues in 2005, the standard treatment for newly diagnosed glioblastoma consists of surgical removal of the tumor, followed by radiotherapy and concomitant chemotherapy with temozolomide. The 18 kDa Translocator Protein (TSPO), previously known as the peripheral benzodiazepine receptor (PBR) is a mitochondrial membrane protein known to be implicated in cholesterol transport, protein import, transport of porphyrin, cell proliferation and apoptosis through its interaction with VDAC (Voltage-Dependent Anion Channel) in the mitochondrial permeability transition pore (PTPM). Previous studies have reported overexpression of TSPO in brain tumors, suggesting that this protein may represent a molecular target for the therapy of GBM. In particular, Erucylphosphohomocholine (ErPC3, erufosine), an alkylphosphocholine, seems to be a promising agent in the treatment of glioblastoma. Previous studies have reported its ability to induce apoptosisin otherwise highly apoptosis resistant glioma cell lines and ErPC3 induced apoptosis seems to require the presence TSPO. [18F]DPA-714, a new TSPO radioligand for positron emission tomography (PET) imaging, was developed at the CEA and validated in different models of neuroinflammation. The hypotheses underlying this thesis are: 1) that the overexpression of TSPO in GBM can be detected by PET imaging using [18F]DPA-714 and 2) that the targeting of TSPO, via specific ligands or via ErPC3, can induce apoptosis in GBM. The objectives of the thesis were: 1) to evaluate the expression of TSPO in a panel of rodent and human glioma cell lines and 2) to characterize, in vitro and in vivo, the anti-neoplastic effect of TSPO ligands (PK11195 and RO5-4864) or ErPC3 in glioma cell lines as well as 3) to develop a preclinical model for in vivo PET imaging using [18F]DPA-714 to monitor treatment efficacy of selected ligands. In this thesis, we demonstrated the feasibility of using PET imaging with [18F]DPA-714 to characterize 9L glioma in an orthotopic rat model and to evaluate the effect of ErPC3 treatment, which could provide a new approach to molecular imaging of GBM. We confirmed the pro-apoptotic effect of ErPC3 in the rat 9L glioma cells in vitro and in vivo, and found an infiltration of microglia/macrophages (CD11b-positive) and astrocytes (GFAP-positive) in the tumor area of animals treated with ErPC3. These results open interesting perspectives for clinical research in the treatment of GBM
Tiss, Amal. "Joint Reconstruction of Longitudinal Positron Emission Tomography Studies for Tau Protein Imaging". Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS387.pdf.
Texto completo da fonteThe accumulation of the paired helical filament tau protein leads to the cognitive decline seen in Alzheimer’s disease (AD). The Positron Emission Tomography tracer, [18F]-AV-1451, permits the observation of PHF tau in vivo. To determine the rate of tau deposition in the brain, the conventional approach involves scanning the subject two times (2-3 years apart) and reconstructing the images separately. Region-specific rates of accumulation are derived from the difference image which suffers from an increased intensity variation making this approach inadequate for clinical trial looking at the effect of a candidate drug on tau because the increased variation leads to a higher sample size required. We propose a joint longitudinal image reconstruction where the tau deposition difference image is reconstructed directly from measurements leading to a lower intensity variation. This approach introduces a linear temporal dependency and accounts for spatial alignment, and the different injected doses. We validate the reconstruction method by simulating higher tau accumulation in real data at different intensity levels. We additionally reconstruct the data from 123 subjects: 109 healthy subjects, 10 suffering from mild cognitive impairment, and 4 diagnosed with AD. The joint reconstruction shows better contrast in the difference image obtained by the numerical simulations and a drastically reduced variance in the change of the Standard Uptake Value Ratio among subjects. The decreased variance of our method leads to a smaller sample size for a potential clinical trial evaluating the effect of a candidate drug against AD
Mesguich, Charles. "Apport de l’imagerie fonctionnelle par TEP dans la prise en charge diagnostique et thérapeutique du myélome multiple et comparaison à l’IRM de diffusion". Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0229.
Texto completo da fonteTherapeutic changes over the past decade have contributed to an improvement in the survival of Multiple Myeloma (MM). Newer whole-body imaging techniques, such as 18-FDG PET-CT (PET-FDG) and MRI, have replaced radiological surveys for diagnostic purposes but also therapeutic evaluation. However, each of these modalities has its limits. Diffusion-weighted MRI (DW-MRI), analysis of tumor heterogeneity with the help of artificial intelligence (AI) as well as the development of new PET radiotracers are three important ways that may contribute to improve MM patient’s management. The general objective of this work was to assess the contribution of these new approaches during the initial diagnosis of MM as well as during therapeutic evaluation.The first part of this work was to prospectively compare the detection of focal bone lesions by FDG-PET and DW-MRI in a population of newly diagnosed MM. The second part of this work was to assess the contribution of radiomics coupled to AI for the diagnosis of diffuse bone marrow disease in FDG-PET. The third part of this work was devoted to the prospective comparison of the prognostic values of FDG-PET and DW-MRI during the therapeutic evaluation of MM eligible to autologous stem cell transplantation. The last part describes the protocol that aims at comparing the performance of 18F-Fluorocholine PET-CT and FDG-PET in the initial work-up of MM
Nguyen, Duc Loc. "Apport de l’imagerie TEP TSPO dans un modèle d’épilepsie mésio-temporale chez la souris". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS393/document.
Texto completo da fonteThe model induced by unilateralinjection of kainic acid is considered as the bestreliable model for the mesial temporal lobeepilepsy (MTLE) and reproduces theepileptogenesis and the typical hippocampalsclerosis (HS).Recent ex vivo studies have revealed theexistence of neuroinflammation in the HS ofepileptic patients and animal models. The18kDa translocator protein (TSPO), which iscurrently the most widely studied with variousradiotracers, is considered as a reference targetto visualize and quantify theneuroinflammation.In that context, my thesis focused ondetermining the evolution of TSPO during theconstitution of HS using 18F-DPA-714positrons emission tomography (PET) in alongitudinal study in this mouse model, and toidentify its origin fromimmunohistofluorescence analysis.We demonstrated the feasibility of PET tomonitor in vivo the inflammatory process evenin small cerebral structures both by the localmeasurement of the percent injected dose or bythe measurement of the volume of distribution.The peak signal was found during theepileptogenesis and corresponded to activatedmicroglia, and then this signal decreased butpersisted after the HS was well established, andmainly originated from activated astrocytesduring this period.Our main results allowed us to identifydifferent phases during which potential antiepileptictreatment targeting differentcomponents of neuroinflammation could beinvestigated
Patin, Delphine. "Le radiopharmaceutique en TEP : imagerie des lymphomes non-Hodgkiniens avec la [18F]Fludarabine ; synthèse, radiosynthèse et évaluation in vivo d’un procédé de vectorisation". Caen, 2013. http://www.theses.fr/2013CAEN2087.
Texto completo da fonteWe have investigated the radiosynthesis of Fludarabine, a drug used for the treatment of lymphoproliterative disorders, to develop a specific tracer of non-Hodgkin’s lymphoma for PET imaging. The radiolabelling with fluorine-18 and its automation on commercial apparatus were performed. The in vivo evaluation in preclinical studies showed that [18F]Fludarabine presents a better contrast than [18F]FDG and could be useful for diagnosis and monitoring of non-Hodgkin’s lymphoma. In a second part and in order to develop a tool for studying the norepinephrine system, involved in numerous cerebral pathologies, we have focused our research in the cerebral vectorization of MIBG. We developed a system based on 1,4-dihydroquinoline / quinolinium salt redox system and realized its labeling with carbon-11. The in vivo evaluation allowed to validate this chemical delivery system which would next used to vectorize the [125I]MIBG to the central nervous system
Onoma, Dago Pacôme. "Segmentation des lésions tumorales en imagerie TEP au 18F-FDG basée sur la marche aléatoire : Application aux petites lésions et aux lésions hétérogènes". Rouen, 2013. http://www.theses.fr/2013ROUES057.
Texto completo da fonteFor external radiotherapy treatment planning, Positron Emission Tomography (PET) using 18F-FDG functional imaging provides metabolic information complementary to anatomic imaging (CT) in the tumor target volume delineation. Indeed, it provides good detection and discrimination of tumor cells to define the tumor target volume in radiotherapy, especially for patients with lung cancer and head and neck tumors. In this context, it is essential to provide an accurate automatic segmentation method dealing with some specific problems in PET imaging, such as the partial volume effect and the physiological heterogeneity often found in the lesions. To this aim, we have implemented a method based on the Random Walk (RW) theory. Algorithmic improvements of the original method have been proposed corresponding to the semi-automatic definition of seeds based on the Fuzzy-C-Means algorithm taking into account the heterogeneity present in the lesion. In addition, we have proposed to make the parameter β adaptive by integrating the distance between adjacent voxels in the "weight" modeling of the walker and the integration of the probability density in the system of linear equations used in the RW to take partial volume effect into account. Due to the fact that the improvements have been done using local information, the segmentation algorithm is called 3D-Locally Adaptive Random Walk (3D-LARW). The performances of the method have been evaluated on PET images of a physical phantom, analytically simulated heterogeneous lesions, as well as on patient data. These performances have been compared with those of the original method (RW), an adaptive thresholding method (TAD) and a fuzzy method (FLAB). The results have shown that our method gives better overall performances whatever the studied data and the evaluation criteria. On the physical phantom, the results have shown the promising contribution of our approach for small lesions in which partial volume effect occurs. In addition, significant difference between our approach and other methods (TAD and FLAB) have demonstrated the robustness of the random walk against the physiological heterogeneities often found in the lesions on simulated data and heterogeneous lesions of patient data
Verger, Antoine. "Quantification du métabolisme glycolytique cérébral en imagerie TEP au 18F-FDG : caractérisation de l’impact du vieillissement et de sa composante accélérée d’origine vasculaire". Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0274/document.
Texto completo da fonte18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) is a brain-imaging technique allowing brain glycolytic metabolism to be quantified. The aim of this doctoral thesis work was to try to better characterize the aging-related changes in brain metabolism, including the part with a possible vascular origin, thanks to a three-dimensional voxel-based quantitative analysis of 18F-FDG PET images. Our work shows firstly that there is a clear advantage to use a particular spatial normalization software (BM: Block Matching) for the brain quantitative analysis, at least for the providing of templates adapted to each study population. This advantage was shown, initially, for the localization of temporal epileptic foci and thereafter, for quantifying the age-related changes in brain metabolism (enhanced determination of the involved brain areas). With this method, a decrease in brain metabolism could be documented throughout the life especially within certain frontal areas. In addition, we tried to determine the component of cerebral aging, which might be of a vascular origin and thus, susceptible to be treated or prevented by vascular treatments. In this research field, we have shown that microvascular abnormalities, setting within white-matter and called leukoaraiosis, were associated with a decrease in the grey-matter metabolism, in particular within certain frontal areas. This effect was independent of the inherent effect of age and of cortical atrophy. Finally, in a population of older patients with a high prevalence of hypertension, we showed that the blood pressure level was correlated to a brain metabolic remodeling, especially when this pressure was measured at central level and when considering the pulse pressure and a threshold value of 50 mmHg. The global cerebral aging and its acceleration in relation to vascular factors may be assessed by 18F-FDG PET when using an adapted voxel-based quantitative method. This assessment could potentially be useful for the monitoring of vascular treatments and for differentiating the aging- and vascular-related metabolic changes to those corresponding to brain diseases of other origins
Lerond, Jérôme. "Système sérotoninergique 5-HT1A et schizophrénie : étude par tomographie par émission de positons au p-[18F]MPPF chez des patients schizophrènes traités par antipsychotiques". Thesis, Nancy 1, 2011. http://www.theses.fr/2011NAN10152/document.
Texto completo da fonteBackgrounds: Multiple post-mortem and pharmacological studies suggest a key role of the serotonergic 1A (5-HT1A) system in the pathophysiology of schizophrenia. Materials and methods: The aim of our work was to assess the 5-HT1A receptors availability In patients suffering from schizophrenia treated with different antipsychotic drugs, compared to controls, using a new ligand antagonist of 5-HT1A receptors, the [18F]MPPF. The 5-HT1A binding potential of 19 schizophrenic patients (treated with either aripiprazole (a 5-HT1A partial agonist) or Second Generation Antipsychotic (olanzapine or risperidone) was compared with that of 19 age-matched healthy controls. This is the first report of a [18F]MPPF PET study in treated patients with schizophrenia. Results: A significant reduction of [18F]MPPF BPND was found in treated patients with schizophrenia compared to age- and gender-matched healthy subjects. These modifications were mainly localized in the frontal and orbitofrontal cortex and may reflect either the pathophysiology of schizophrenia or medication effects. In comparison to matched healthy subjects, the reduction of 5-HT1A receptor availability was more extensive in schizophrenic patients with aripiprazole treatment than in schizophrenic patients with SGA treatment. Conclusion: These results suggest that aripiprazole has a major impact on [18F]MPPF BPND, likely due to its partial agonist activity at 5-HT1A receptors. In order to distinguish the relative contributions of the disease itself versus medication effects, future [18F]MPPF studies should be performed in APD-naïve patients with schizophrenia
Merabet, Zennadi Manel. "Évaluation de la place de l'imagerie cérébrale morphologique et métabolique dans le phénotypage diagnostique et thérapeutique des TCA". Electronic Thesis or Diss., Saint-Etienne, 2023. http://www.theses.fr/2023STET0061.
Texto completo da fonteThe most common eating disorders are anorexia nervosa and bulimia nervosa; they represent a serious public health problem with significant physical and psychological consequences. In the context of emerging precision medicine, various fields are increasingly turning to patient phenotyping to improve treatment and personalize healthcare. This research has focused on bulimia nervosa and anorexia nervosa, aiming to define the role of metabolic and morphological brain imaging in their therapeutic and prognostic pathways. Aims : Analyze the link between cerebral serotonergic activity and the efficacy of fluoxetine in bulimia nervosa ; Analyze the relationship between the morphology and function of the pituitary gland in anorexia nervosa ; Creation of an MRI atlas of the pituitary gland. We used positron emission tomography with the radioligand [18F]MPPF to analyze cerebral serotonergic activity in bulimia nervosa, and correlations with the response to fluoxetine, as well as voxel-wise analyses, were performed using SPM. For the study of pituitary gland morphology in anorexia nervosa, we manually delineated anterior and posterior lobes of the gland and conducted correlations with pituitary hormones. From pituitary delineations in control women, we created an optimized MRI atlas using a "lesion cost masking" approach with SPM. We found a negative correlation between BPND [18F]MPPF in the dorsal raphe nucleus (before fluoxetine) and the response to fluoxetine in bulimia nervosa. Significant differences in BPND [18F]MPPF were also observed before and after fluoxetine treatment in limbic regions among responders but not in non-responders. In anorexia nervosa, a correlation was found between the volume of the anterior pituitary and growth hormone. The MRI atlas of the global, anterior, and posterior pituitary showed good concordance and correlation with manual delineations. In the field of eating disorders, both metabolic and morphological brain imaging undoubtedly play a significant role. It helps unravel mysteries still surrounding the pathophysiology of these disorders. Our results also suggest the dorsal raphe nucleus activity as a biomarker for fluoxetine response in bulimia nervosa. As for pituitary volume, it appears to be a good marker of disease severity. Our pituitary atlas aims to eliminate manual delineations, providing a significant time-saving advantage in clinical research
Michel, Marion. "Conception, synthèse et validation de molécules hétérocycliques fluorées ciblant IDO et/ou TDO pour le traitement de la neuroinflammation et son diagnostic par imagerie 18F-TEP". Electronic Thesis or Diss., Orléans, 2023. http://www.theses.fr/2023ORLE1051.
Texto completo da fonteThe ageing of the global population has led to an increase in the number of people suffering from neurodegenerative diseases, with the concomitant lack of curative treatments. Consequently, the development of new diagnostic and therapeutic tools to improve care for these patients has become a major research challenge.Many of these diseases, including Alzheimer's, Parkinson's and Lou Gehrig's disease, follow the same pathophysiological process known as neuroinflammation. This mechanism of cerebral immunity, which emerges at the earliest stages of the disease, has recently become the focus of scientific interest. Indoleamine 2,3-dioxygenase (IDO) and Tryptophan 2,3-dioxygenase (TDO) enzymes, involved in the catabolism of tryptophan, have been identified as being over-expressed in the context of neuroinflammation and appear to play a key role in it.Positron emission tomography (PET) is a precision imaging-technique giving access to the functional study of organs such as the brain. This non-invasive technique can thus be used for the diagnosis, monitoring and quantification of CNS diseases by the administration of specific radiotracers targeting this area.In order to design powerful fluorinated radioligands specific to the IDO and TDO enzymes, we began this research project by transposing IDO ligands form the literature into new 18F-labelled radioligands. We then developed original chemical series with a [6-5] or [6-5-5] scaffold to obtain mixed or selective TDO ligands. Finally, the exploration of the chemical space in the heterocyclic domain led us to the novel design of fluorinated TDO-selective ligands with a high potential for development
Humbert, Olivier. "Imagerie TEP au 18F-FDG du cancer du sein : étude du comportement métabolique des différents phénotypes tumoraux et prédiction de la réponse tumorale à la chimiothérapie néoadjuvante". Thesis, Dijon, 2015. http://www.theses.fr/2015DIJOS024/document.
Texto completo da fontePositron Emission Tomography (PET) with 18Fluoro-deoxyglucose (18F-FDG) is the reference imaging examination for in-vivo quantification of the glucidic metabolism of tumour cells. It allows for the monitoring of tumour metabolic changes during chemotherapy. Breast cancer comprises several distinct genomic entities with different biological characteristics and clinical behaviours, leading to different tailored treatments. The aim of this doctoral thesis was to evaluate the relationship between the different biological entities of breast cancer and the tumour metabolic behaviour during neoadjuvant chemotherapy. We have also retrieved, among the various metabolic parameters on PET images, the most reliable ones to predict, as early as after the first neoadjuvant cycle, the final tumour histologic response and patient’s outcome. We have also evaluated early changes in tumour blood flow, using a tumour first-pass model derived from an dynamic 18F-FDG-PET acquisition.The first article presented in this thesis has underlined the strong correlation between breast cancer subtypes, and the tumour metabolic behaviour during chemotherapy. The following three articles have demonstrated that tumour metabolic changes after the first neoadjuvant cycle can predict the final histologic complete response at the end of the treatment, both in triple-negative and HER2 positive tumours. Concerning the luminal/HER2 subtype, the early metabolic response mainly predicts patient’s outcome.These results should lead, in the near future, to PET-guided neoadjuvant strategies, in order to adapt the neoadjuvant treatment in poor-responding women. Such a strategy should lead to enhanced personalized medicine
Vauclin, Sébastien. "Segmentation et étude par simulations Monte Carlo de l’apport de la synchronisation respiratoire en imagerie TEP ou 18F-FDG à visée de radiothérapie conformationnelle des tumeurs pulmonaires". Rouen, 2009. http://www.theses.fr/2009ROUES009.
Texto completo da fonteFor external radiotherapy treatment planning, Positron Emission Tomography (PET) using 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) thoracic functional imaging currently demonstrate a great interest in the definition of the tumoral target volume, especially in patients with "Non Small Cell Lung Cancers". To that end, it is essential to have efficient automatic segmentation method and to accuratly synchronize the acquisition of PET data to the patient breathing. For this purpose, 3 automatic and iterative thresholding methods (Methods №1, №2 and №3) inspired of literature approaches, but with significant algorithmic modifications were implemented and studied using data acquired on physical phantoms, as well as patients. The results were compared with those of a fixed threshold of 40% of the maximum intensity within the hyperfixation (I_MaxHyp), as well as the "manual" delineation of two experimented nuclear physicians. This work underlines that the Method №2 is the most accurate while being easy to implement in clinical routine. From the point of view of functionnal volume restitution on physical phantoms, measurement errors committed with this approach are in median equal to 0. 33 mL and 50% of them (i. E. The interquartile range) are respectively included between -0. 97 mL et 0. 76 mL. Then, the contribution of respiratory gating was studied. To that end, 18F-FDG phase respiratory-gated PET thoracic exams were simulated by Monte Carlo method using the GATE software, the SIEMENS Biograph Sensation 16 Hi-Rez PET scanner model and the 4D NCAT numerical thoracic voxelised phantom. The contribution of respiratory gating was emphasized and it was also shown that it seems preferable to reconstruct the acquired data with a number of temporal frames allowing to optimize obtained results according to the desired purpose. Indeed, a respiratory cycle sampling of 8, 5 and 3 frames seems respectively the best adapted for the measurement of real functionnal occupancy volumes covered by the lesions during breathing, towards the restitution of I_MaxHyp and for the visual detectability of tumors. These works should have a significant impact on the treatment planning in external radiotherapy
Anouan, Koutoua Joseph. "Correction de l'effet de volume partiel en imagerie fonctionnelle par TEP au 18F-FDG pour le suivi thérapeutique de patients atteints de cancer pulmonaire non à petites cellules". Rouen, 2013. http://www.theses.fr/2013ROUES028.
Texto completo da fontePan, Xiaoxi. "Towards FDG-PET image characterization and classification : application to Alzheimer's disease computer-aided diagnosis". Thesis, Ecole centrale de Marseille, 2019. http://www.theses.fr/2019ECDM0008.
Texto completo da fonteAlzheimer's disease (AD) is becoming the dominant type of neurodegenerative brain disease in elderly people, which is incurable and irreversible for now. It is expected to diagnose its early stage, Mild Cognitive Impairment (MCI), then interventions can be applied to delay the onset. Fluorodeoxyglucose positron emission tomography (FDG-PET) is considered as a significant and effective modality to diagnose AD and the corresponding early phase since it can capture metabolic changes in the brain thereby indicating abnormal regions. Therefore, this thesis is devoted to identify AD from Normal Control (NC) and predict MCI conversion under FDG-PET modality. For this purpose, three independent novel methods are proposed. The first method focuses on developing connectivities among anatomical regions involved in FDG-PET images which are rarely addressed in previous methods. Such connectivities are represented by either similarities or graph measures among regions. Then combined with each region's properties, these features are fed into a designed ensemble classification framework to tackle problems of AD diagnosis and MCI conversion prediction. The second method investigates features to characterize FDG-PET images from the view of spatial gradients, which can link the commonly used features, voxel-wise and region-wise features. The spatial gradient is quantified by a 2D histogram of orientation and expressed in a multiscale manner. The results are given by integrating different scales of spatial gradients within different regions. The third method applies Convolutional Neural Network (CNN) techniques to three views of FDG-PET data, thereby designing the main multiview CNN architecture. Such an architecture can facilitate convolutional operations, from 3D to 2D, and meanwhile consider spatial relations, which is benefited from a novel mapping layer with cuboid convolution kernels. Then three views are combined and make a decision jointly. Experiments conducted on public dataset show that the three proposed methods can achieve significant performance and moreover, outperform most state-of-the-art approaches
Dierickx, Lawrence O. "Quantitative data analysis and functional testicular evaluation using PET-CT and FDG". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30400.
Texto completo da fonteThe aim of this thesis is to evaluate the use of PET/CT with 18F-FDG for an assessment of the testicular function and to optimise and standardise the acquisition protocol and the testicular volume analysis in order to do that. In chapter I we provide a literature overview where we establish that the 18F-FDG uptake is correlated with the spermatogenesis because of the presence of GLUT 3 transporters on the Sertoli cells and the spermatides and not on the Leydig cells which are responsible for the steroidogenesis. We then provide an overview of the public health problem of male infertility where we point out different possible clinical applications for testicular functional imaging. In chapter II we examine the significant correlation between 18F-FDG uptake in terms of intensity and volume of uptake and the testicular function via the parameters of the sperm analysis. In chapter III, we focus on the standardisation of the acquisition protocol for this specific indication, after a brief technical overview of the PET/CT and of its limitations. Because the first study was done via a manually delineated testicular volume, we re-analysed the correlation with a solid and reproducible adaptive volume segmentation method in a second article. We further focussed on optimising the acquisition protocol by evaluating the impact of the intense urinary activity on the testicular uptake. First we examined this impact with phantom studies where we simulated the bladder and the testes. We proceeded with a clinical study where we aimed to evaluate and compare 2 diuretic protocols. In chapter IV we address the overall important subject, and even more so in this andrological context, of the radioprotection related issues of a PET/CT with 18F-FDG. Finally, in chapter V we provide an overview of some of the issues still to be addressed and the future perspectives for this new direction in the field of nuclear medicine that we could name 'nuclear andrology'
Costes, Nicolas. "Neurotransmission sérotoninergique 5-HT1A : approche méthodologique de la mesure in vivo par le [18F]MPPF en tomographie par émission de positons". Phd thesis, Université Claude Bernard - Lyon I, 2007. http://tel.archives-ouvertes.fr/tel-00180894.
Texto completo da fonteLes travaux contenus dans cette thèse comprennent : i/ une expérience de modélisation compartimentale des échanges in vivo entre le ligand et son récepteur soutenue par une étude chez un échantillon réduit d'hommes sains dans un protocole TEP multi-injection de [18F]MPPF, ii/ la recherche et la validation d'un protocole de modélisation simplifiée grâce à la connaissance du modèle complexe élaboré dans l'expérimentation multi-injection, iii/ la réalisation d'une base de données normative du marquage des récepteur 5HT1A par le [18F]MPPF dans le cas sain, chez les hommes et les femmes au cours de la vie adulte, IV/ la réalisation d'un étude TEP test-retest pour la connaissance de la reproductibilité de la mesure au [18F]MPPF, V/ la constitution d'une base de données simulées par la méthode de Monte-Carlo pour le développement et la validation des outils de correction et d'exploitation de la mesure quantitative de la fixation du traceur.
La base simulée est utilisée pour la mise au point de méthodes de correction (effet de volume partiel) ou de détection (libération de sérotonine endogène).
L'application des travaux expérimentaux est exposée dans le contexte d'une utilisation de cette mesure quantitative à l'usage de la recherche clinique.
Ce travail constitue une phase importante dans le développement d'un traceur : il se situe à l'interface entre les expérimentations biologiques sur l'animal et l'utilisation du traceur TEP dans un examen chez l'Homme.
Omarjee, Loukman. "Atteintes Cardiovasculaires du Pseudoxanthome Élastique : Aspects Physiopathologiques et Stratégies Thérapeutiques". Thesis, Angers, 2019. https://dune.univ-angers.fr/documents/dune15886.
Texto completo da fonteSince the discovery of the ABCC6 gene in 2000, mutations are at the origin of PseudoxanthomeElastic (PXE), knowledge of genetics, pathophysiology, phenotypic characterizations have has mademajor advances, notably with the Discovery in 2013 of the fundamental role of Pyrophosphateinorganic (PPi) as a deficient anti‐calcifying factor in patients. The overall goal of this thesis was tostudy, from the cohort of patients at the center of PXE reference of the CHU d'Angers, differentaspects of cardiovascular phenotype (CV) of PXE. Thus, in a first work, we were able to show in thestudy GOCAPXE, that ectopic calcifications would be a active process that can be detected by imagingUsing a specific activity tracer Osteoblastic, 18‐sodium fluoride (18F‐NaF); that this process wasdetectable even before these calcifications are not visible by conventional imaging techniques; thatthis process was localized to areas usually injured in the PXE: flexion folds and neck for skin and thesuperficial femoral artery for the vessel. This technique should be validated in a study longitudinaland its role as a diagnostic biomarker In this way, monitoring and monitoring could be considered.The second work of this thesis was to study the morphological consequences and functional of achronic increase in blood pressure in PXE patients. This question was relevant because in theliterature, the question of a high blood pressure (hypertension) in PXE remains controversial. Wehave thus shown for the first time that in a model of HTA induced by the Deoxycorticosterone(DOCA)‐Salt in Abcc6‐/‐ this increase in blood pressure led to a CV remodeling with both fibrosis andcalcifications dystrophic. The results of this study suggest need for optimal control of blood pressurein patients. The third work of this thesis was to characterize a lesion of the internal carotid detectedwith high frequency in the Angevine cohort. We have could show that this abnormality washypoplasia of the Probably congenital internal carotid. In the patients of the angevine cohort, thislesion was associated with intracranial aneurysms but we have not found in association with theoccurrence of vascular accident brain. Thus, the results of this study invite practitioners supportingPXE patients to search for it systematically in the vascular balance of a PXE patient. If such a lesion isfound, vascular imaging Intracranial should be proposed to research Aneurysms and theirmanagement discussed in consultation multidisciplinary. Finally, the latest work has made it possibleto show that systemic treatment with Thiosulphate Sodium (STS), used in renal calciphylaxia, waseffective on the regression of arterial calcifications and skin in a young boy with a phenotype CVGravel resulting from the deleterious combination of several pathogenic genes of the PXE spectrumThis treatment would deserve be validated in a human therapeutic trial but also the demonstrationof its mechanisms of action in the Abcc6‐/‐murin model. We suggest using this treatment for severeand rapidly progressive PXE especially on the vascular plane.At the end of this thesis work, we showed that the ABCC6 gene was involved in vascular remodelingat both at the developmental level (Carotid Hypoplasia) but also acquired (Fibrosis, CardiacCalcification Dystrophic). We also showed that calcifications in PXE were tissues and locationsspecific, that these calcifications were active. Finally we have opened the door to a treatment ofsevere forms of PXE with Sodium Thiosulphate. An approach multimodal therapy targeting multiplemechanisms this would be useful to evaluate in future clinical trials
Eldin, Carole. "Coxiella burnetii : de la culture aux manifestations cliniques". Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0034/document.
Texto completo da fonteC. burnetii is an intracellular bacterium. Recently, an axenic medium, named ACCM 2, has been developed and allows the culture of this bacterium in a microaerophilic atmosphere. We tested if the addition of uric acid in the medium could allow an aerobic culture. We observed growth of C. burnetii incubated under aerobic conditions in the ACCM2 medium enriched with uric acid. In Cayenne, French Guiana, pneumonia caused by C. burnetii are frequent and severe. We analyzed the genome of a strain from Cayenne. This work revealed a 6105 bp deletion in the gene of the type 1 secretion system (T1SS). This genome reduction is probably involved in the hypervirulence of Cayenne strains. Finally, we tested the antibiotic suceptibility of 6 strains isolated from patients living in Cayenne. These strains were all susceptible to doxycycline and resistant to macrolides. In a third part we analyzed the contribution of PET scanner in the diagnosis of C. burnetii infections. 167 patients with C. burnetii infections benefited from a PET scan. We found a high proportion of osteo-articular (21) and lymphadenitis (27) fixations, and we proposed new definitions for these locations. We then investigated the impact of surgical treatment in patients with vascular infections. A retrospective analysis of 86 patients with vascular infections showed that surgery was associated with a lower mortality at 2.5 years and a better serological outcome
Dhaynaut, Maëva. "PET imaging for the characterization of tauopathies : Alzheimer's disease and chronic traumatic encephalopathy". Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS197.
Texto completo da fonteTauopathies are neurodegenerative diseases characterized by intracerebral aggregation of abnormal Tau proteins. During this university thesis, we studied by Positon Emission Tomography (PET) imaging the Tau burden in Alzheimer’s Disease (AD) and Chronic Traumatic Encephalopathy (CTE), two different taupotahies with similar Tau isoforms. In this context, our first objective was to determine the ability of Tau PET imaging to improve the diagnosis of AD and to determine the viability of a new potential treatment. We have established that Tau PET imaging was able to detect the beneficial effect of a non-invasive brain stimulation, called transcranial alternating current stimulation (tACS) in people with AD. Our second objective was to determine the usefulness of Tau PET imaging in vivo in a population of American football players to help the early detection of CTE. We have demonstrated that in our population, Tau PET imaging was able to highlight the Tau pathology in early stages of CTE. In parallel, we have studied by autoradiography post-mortem from patients with neuro-pathological diagnosis of AD and CTE the binding pattern of three radiotracers widely used in research for Tau imaging. We directly compared the binding properties of [18F]-AV-1451 with [18F]-MK-6240 and [18F]-PI-2620 in the same specimens. These three tracers showed similar strong binding pattern to Tau protein in AD and a lack of binding in CTE brain slices. In total, these experiments allow to confirm the potential utility of Tau PET tracers for the reliable detection, quantification of Tau aggregates and disease-progression tracking in AD, while it remains questionable for CTE
Bernard, Julie. "Synthèse de pinces à fluorures dérivées d'aminoacides pour l'imagerie TEP". Thesis, Dijon, 2014. http://www.theses.fr/2014DIJOS059/document.
Texto completo da fonteThis thesis project, which is part of a collaboration between the Institut de Chimie Moléculaire de l’Université de Bourgogne and the Positron Emission Tomography Research Centre, is about the synthesis of fluoride pincers derived from amino acids based on 18F-B bond construction to get a new class of PET imaging agents. First, this project concerned the design, synthesis and characterisation of new boronato and trifluoroborato phosphonium amino acid salts. Quaternisation of o-boronate phenyl phosphine with β-iodo amino esters or γ-iodo amino ester leads to the corresponding salts without racemisation and in yields up to 88%. Saponification of boronato phosphonium amino esters afford the free carboxylic acid derivatives, whereas HCl acidolysis leads to the corresponding amino compounds which offers the opportunity of further biomolecule coupling. Then, o-trifluoroborate phosphonium salts are efficiently prepared by reaction with KHF2 in solution on hydroalcoholic mixture. The kinetic stabilities of these o-trifluoroborate phosphoniums have shown extremely stable compounds to hydrolysis. Finally, [18F]-radiosyntheses of phosphonium salts was studied according to two methods : by 18F-19F isotopic exchange from trifluoroborate or by carrier added preparation of [18F]-fluoride ions from boronate phosphonium salts. Satisfactingly, after a total synthesis of 50 minutes (including azeotropic drying, synthesis and purification), [18F]-203c was obtained with a RCY on 10% decay corrected, a RCP ≥ 97% and a specific activity of 0.13 GBq/µmol
Hamelin, Lorraine. "Analyse de la morphologie des sillons corticaux et de l'activation microgliale dans la maladie d'Alzheimer : étude couplée en IRM, TEP-PiB et TEP-DPA Sulcal morphology as a new imaging marker for the diagnosis of early onset Alzheimer’s disease Early and protective microgial activation in Alzheimer's diease: a prospective study using 18F-DPA-714 PET imaging Distinct dynamic profiles of microglial activation are associated with progression of Alzheimer’s disease". Thesis, Sorbonne Paris Cité, 2018. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=2327&f=13526.
Texto completo da fonteNo abstract
Montesino, Orellana Marlene Rossibel. "Caractérisation de l'inflammation artérielle associée au vieillissement par la tomographie d'émission par positrons (TEP)". Mémoire, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6082.
Texto completo da fonteKaridioula, Ismaël. "Quantification automatique de la fixation du FDG dans les tumeurs pulmonaires en imagerie TEP-TDM". Clermont-Ferrand 1, 2007. http://www.theses.fr/2007CLF1MM20.
Texto completo da fonteTixier, Florent. "Caractérisation de l'hétérogénéité tumorale sur des images issues de la tomographie par émission de positons (TEP)". Phd thesis, Université de Bretagne occidentale - Brest, 2013. http://tel.archives-ouvertes.fr/tel-00991783.
Texto completo da fonteBodet-Milin, Caroline Kraeber-Bodéré Françoise. "Intérêt de la TEP au 18-FDG dans l'évaluation de la réponse à la radioimmunothérapie des patients porteurs de lymphomes malins non hodgkiniens traités par Yttrium-90 Epratuzumab". [S.l.] : [s.n.], 2005. http://theses.univ-nantes.fr/thesemed/SPEbodet.pdf.
Texto completo da fonteGauthé, Mathieu. "Optimisation médico-économique des stratégies d'utilisation des examens TEP/TDM en imagerie oncologique". Thesis, Université de Paris (2019-....), 2020. http://www.theses.fr/2020UNIP7040.
Texto completo da fontePositron emission tomography coupled with computed tomography (PET/CT) devices are essential pathways in oncology. Many studies have reported the performances of the various radiopharmaceutical drugs (RPD) used for PET/CT imaging in many cancers. The rise of PET/CT remains slowed down in France for economic reasons. However, the difference between the cost of a PET/CT examination, compared to that of another modern imaging routinely used in the same indication, is not so obvious once considered the impact on decision making and the costs avoided by the revision of erroneous or incomplete diagnoses. Nonetheless, if all PET/CT examinations are currently reimbursed in the same way regardless of the RPD used, thus making their cost identical from the health insurance perspective, their production costs for the hospital vary and should be considered according to the frequency of the indication of the examination.We compared several imaging strategies for prostate cancer imaging by analyzing the data acquired during the French prospective multicenter FLUPROSTIC study, which included two RPD for PET imaging: 18F-flurocholine (FCH) and 18F-sodium fluoride (NaF), FCH being twice more costly for the hospital than NaF.The analysis of the impact of each imaging strategy on decision making, based on dedicated questionnaires completed by the referring clinicians, demonstrated that FCH PET/CT was the imaging modality that had the highest impact, especially for patients presenting with first biochemical recurrence.The cost-utility analysis, carried out from the health insurance perspective for patients with first biochemical recurrence of prostate cancer over a "lifetime" time horizon, was based on a model5combining a decision tree integrating the diagnostic performances of imaging and a Markov model simulating the natural history of prostate cancer. This analysis demonstrated that FCH PET/CT, the most accurate imaging modality from a diagnostic point of view, had a 100% probability of being the most cost-effective strategy for willingness to pay thresholds of 3,000€ or 9,000€ per quality-adjusted life year gained if the imaging reading was made by local specialists or experts respectively. From the hospital perspective, the 20% drop in the cost of FCH between 2018 and 2019 had made profitable the production of FCH PET/CT examinations for prostate cancer imaging.PET/CT increases diagnostic accuracy and has an impact on decision making in many cancers. It helps to reduce unnecessary treatments and their potential side effects, to improve the quality of life of patients and to reduce the treatment costs for the health care system. The medico-economic evaluation of RPDs used for PET/CT imaging in oncology, in addition to that of their diagnostic performances, seems essential in order to optimize their use. In France, this evaluation should be made from both perspectives of the health insurance and the hospital. Indeed, the PET/CT production costs can largely vary for the hospital according to the RPD costs and constitute a barrier to its use, even in a frequent indication for which diagnostic performances and impact on decision making are high
Abgral, Ronan. "Tomographie par émission de positons au 18F-fluorodesoxyglucose et carcinome épidermoïde des voies aérodigestives supérieures réfractaire au traitement". Phd thesis, Université de Bretagne occidentale - Brest, 2013. http://tel.archives-ouvertes.fr/tel-00952418.
Texto completo da fonteJoyard, Yoann. "Synthèse de nouveaux radiomarqueurs potentiels de l’hypoxie tumorale : Développement d’une nouvelle méthodologie de fluoration nucléophile et son application vers la synthèse du 2-[18F]Fluoro-2-désoxy-D-glucose". Thesis, Rouen, INSA, 2013. http://www.theses.fr/2013ISAM0018/document.
Texto completo da fonteIt has been recognized that hypoxia plays a major negative role in overall tumor progression. The identification and quantitative estimation of tumor hypoxia by means of nuclear imaging is an important factor in planning the therapeutic strategy for a better clinical outcome. In the present work, a new 99mTc tracer for imaging tumor hypoxia has been successfully developed. New organosilicon fluorinated derivatives were also studied. Every synthesized compounds incorporated a nitroimidazole moiety, which is selectively trapped in hypoxic cells. The second part of this work, led to the development of a new nucleophilic fluorination strategy for the preparation of PET tracers. The new strategy was attempted for the preparation of Fluorodeoxyglucose. In the course of this study, a novel oxidative deprotection method of thiols was developed. Herein was described, the synthesis of sulfonic acid derivatives by oxidative deprotection of thiols using tert-butyl hypochlorite
Bragulat, Véronique. "Approche anatomo-fonctionnelle des systèmes monoaminergiques dans la dépression avec la [18F]-dopa et dans la dépendance tabagique avec la [11C]-béfloxatone grâce à la tomographie par émission de positons". Paris 6, 2003. http://www.theses.fr/2003PA066033.
Texto completo da fonteJacquemin, Manon. "Etude de l’impact du radiomarquage de cellules avec des émetteurs β+ pour l'imagerie TEP : développement dosimétrique à l'échelle multi-cellulaire, analyse des paramètres d'influence et application au cas du ¹⁸F-FDG". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP007.
Texto completo da fonteIn vitro labelling of cells with β+-emitting radionuclides combined with nuclear medicine imaging is a potential method for in vivo cell trafficking analysis with PET imaging. The labeling-associated exposition of cells to high levels of activity still raises some concerns since it may result in cell death and therefore a loss of image quality. In addition, the administration of potentially damaged cells rises essential questions regarding the safety of such procedure. This research work was conducted with a view of better understand the issues underlying the radiolabelling procedure in order to optimize the current clinical practice. More precisely, this thesis focused on the calculation of the absorbed doses to cells during in vitro ¹⁸F-FDG radiolabelling and the correlation to the biological observed effects. As a first step, computing tools at the multi-cellular scale were developed and optimized. Based on a generic approach, we explored and compared several hybrid methods mixing Monte Carlo simulations, analytic approaches or molecular dynamics. Then, JURKAT and adipose mesenchymal stem cells (adMSCs) were radiolabelled with ¹⁸F-FDG and tested for clonogenic survival assay, cell cycle analysis and ᵧ-H2AX phosphorylation quantification. A multi-cellular dosimetry model describing the full experiment, from the incubation of cells with ¹⁸F-FDG, washing steps, to culture of cells for functional assays was developed. Dynamic changes in cell density, as well as experimentally determined activity uptake and retention with time were thus considered. Lastly, the mean cell absorbed dose was correlated with the three biological endpoints and results were compared with X-ray irradiation. The results helped to better understand the irradiation features associated to ¹⁸F-FDG labelling and the observed biological effects, thus providing a knowledge base in favour of harmonizing the labelling methods
Ciappuccini, Renaud. "Apport de l'imagerie fonctionnelle par TEMP/TDM et TEP/TDM dans la prise en charge des cancers différenciés de la thyroïde Incremental Value of a Dedicated Head and Neck Acquisition during 18F-FDG PET/CT in Patients with Differentiated Thyroid Cancer Full text links full-text provider logo Actions Favorites Share Page navigation Title & authors Abstract Conflict of interest statement Figures Similar articles Cited by References Related information LinkOut - more resources EJNMMI Res . 2018 Dec 3;8(1):104. doi: 10.1186/s13550-018-0461-x. Optimization of a dedicated protocol using a small-voxel PSF reconstruction for head-and-neck 18 FDG PET/CT imaging in differentiated thyroid cancer 78 Lymph node involvement in head-and-neck and thyroid cancers with digital PET/CT: the impact of ultra-high definition voxels and point-spread function Tumor burden of persistent disease in patients with differentiated thyroid cancer: correlation with postoperative risk-stratification and impact on outcome 133 18F-Fluorocholine PET/CT is a highly sensitive but poorly specific tool for identifying malignancy in thyroid nodules with indeterminate cytology: The Chocolate study PSMA expression in neovasculature of persistent/recurrent differentiated thyroid cancerin the neck: relationship with radioiodine uptake, 18Fluorodeoxyglucose avidity and outcome". Thesis, Normandie, 2020. http://www.theses.fr/2020NORMC424.
Texto completo da fonteRadioiodine (131I) and 18-Fluorodeoxyglucose (18FDG) are two radiopharmaceuticals used for scintigraphic imaging in differentiated thyroid cancers (DTC). Tumour uptake of each tracer depends on tumour differentiation and aggressiveness. Our goal was to further assess various technical aspects in DTC imaging workup, such as SPECT/CT and PET/CT, point-spread function (PSF), voxel size, digital PET, and to explore further other PET tracers. The aim of the first part was to assess the performance of 18FDG PET/CT for the detection of neck lymph node involvement. A dedicated PET/CT acquisition improved tumour detection compared to the whole-body acquisition. PSF reconstruction allowed detection of smaller cancer deposits and the optimal acquisition duration time was assessed. Using digital PET acquisitions, ultra-thin voxels reconstructions were performed. The impact of ultra-thin voxels and PSF on quantitative values was evaluated. The second part focused on 131I-SPECT/CT and 18FDG-PET/CT imaging, in an attempt to assess tumour burden of persistent disease. Tumor burden was correlated with the postoperative risk and affected the response to therapy. In the third part, another PET tracer, i.e. 18-Fluorocholine (FCH), and a marker of neovasculature, i.e. prostate-specific membrane antigen (PSMA), were studied. FCH PET/CT offered high negative predictive value to reliably exclude cancer in PET-negative nodules with indeterminate cytology and might prevent unnecessary surgeries. Also, PSMA expression assessed with immunohistochemistry was associated with poor prognosis factors. Further studies are needed to confirm new insights of FCH PET and 68Ga-PSMA PET in DTC
Parent, Maxime. "Utilisation du [18F]Fluoro-éthoxybenzovesamicol ([18F]FEOBV) avec la tomographie par émission de positrons (TEP) comme mesure in vivo de la perte neuronale cholinergique chez le rat". Mémoire, 2011. http://www.archipel.uqam.ca/4668/1/M12396.pdf.
Texto completo da fonteLee, Yanick. "Radiosynthesis of hexadecyl-4-[18F]fluorobenzoate for labeling exosomes and chitosan hydrogels". Thèse, 2017. http://hdl.handle.net/1866/19446.
Texto completo da fontePositron emission tomography (PET) is a powerful nuclear imaging modality allowing for non-invasive functional measures in cells, animals and humans with high sensitivity. Exosomes are 30-120 nm extracellular vesicles that can transfer their cytoplasmic contents between cells, however, understanding where exosomes traffic in the body remains a challenge. Chitosan-based thermosensitive hydrogels have been developed and are currently under optimization for various applications such as blood vessel embolization, drug delivery, lymphocyte delivery systems, and cartilage and intervertebral disc repair. There is an urgent need for in vivo, short term follow-up of such procedures to assess the retention of hydrogels and exosomes at the site of injection. Hexadecyl-4-[18F]fluorobenzoate ([18F]HFB) is a long chain lipophilic radiotracer that has been reported to be retained within cell membranes or biomaterials. The aim of this work was to automate the radiosynthesis of [18F]HFB for labeling exosomes and chitosan-based hydrogels. The radiosynthesis and purification of [18F]HFB was done using the commercial IBA Synthera® chemistry synthesiser with the R&D IFP-cassette and HPLC module. As previously reported, [18F]HFB was prepared by [18F]F- substitution of the trimethyl ammonium triflate precursor in DMSO. After removal of unreacted [18F]F- and DMSO via a C18 light cartridge, [18F]HFB was eluted with acetonitrile and purified by semi-prep C18 HPLC. [18F]HFB was then reformulated in DMSO (10%) solution after removal of the HPLC solvent from the radioactive product peak under nitrogen, filtered, and diluted in sterile saline. [18F]HFB was obtained in radiochemical yield (isolated after HPLC and evaporation) ranging from 15 – 45% (decay-corrected), high radiochemical and chemical purities, and within a total synthesis time of 60 mins. Exosomes were not successfully labeled. However, high labeling efficiency was observed with the chitosan hydrogels displaying a stability >90%, even after 8 hours incubation in saline. PET imaging with [18F]HFB of exosomes and biomaterials presents a novel approach to determining their in vivo distribution.