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1.
The examples and clinical cases presented in this section are not intended to be considered as absolute models in terms of image quality or device parameter settings. They must initiate an individual analysis according to CT parameters and image quality. Nevertheless, they present practically different CT levels which can be used according to the clinical context and the type of device.  相似文献   

2.
The aim of our study was to assess the contribution of image fusion of SPECT combined with computed tomography (SPECT-CT) or magnetic resonance imaging (SPECT-MRI) in our daily practice of bone scintigraphy. Seventeen patients underwent a SPECT image fusion, SPECT-CT or MRI in addition to conventional bone scintigraphy. These acquisitions are made separately with images stored in DICOM format. The fusion was operated after a manual coregistration of the images. Results show that in 35.29% of cases, the image fusion allowed to pinpoint the exact location of increased uptake seen on the whole body scan and/or on static images. In 35.29% of cases, the fusion has confirmed a diagnosis doubtful in planar imaging. In five patients, representing 29.41% of cases, the fusion has corrected a diagnosis. In one patient (5.88% of cases), the fusion has eliminated a false positive related to increased uptake visualized on the whole body scan. In two patients (11.11% of cases), the fusion has eliminated false negative of bone scan in one case and of MRI in the other case. Finally, in nine patients (50% of cases), the fusion has influenced the therapeutic management.  相似文献   

3.
Nuclear medicine could significantly contribute to management of patients with prostate carcinoma. Apart from bone scintigraphy, and success of sentinel lymph node procedure, from a diagnosis point of view 18F-fluorocholine, which is now disposable, will certainly allow better staging accuracy, better efficiency of recurrences detection, and better treatments evaluation. Regarding to treatments, several radiopharmaceuticals demonstrated their efficiency as palliative treatment of painful bone metastasis, and maybe in the near future will contribute to curative treatment when associated to chemotherapy.  相似文献   

4.
To increase the germplasm necessary for varietal improvement of tuberous-rooted chervil, a food apiaceae of increasing importance, two successive surveys of wild populations were carried out in Germany, in the Rhine and the Weser River basins. These mainly riparian populations are likely to be shaped by changes in hydrographic networks that characterize their habitat. Molecular studies have shown a strong structuration between wild populations (GST ∼ 32 %), but did not reveal any structuring effect of the hydrographic network on diversity or any global phenomenon of genetic erosion. A discussion about the strategy for maintaining the diversity of this species on a long-term period is proposed.  相似文献   

5.
Residual radioactivity within decay tanks in an in-hospital clinical nuclear medicine unit reflects the specific typology of the concerned unit. To learn how to improve management of emptying the tanks, measures of residual radioactivity over the year 2009 have been compared to prevailing legal norms in Luxembourg. Legal norms have in no case been outpassed. A minimal residual radioactivity, below legal thresholds, has been often found (84%). It concerned 131I, 99mTc and 111In. This is why management of radioactive decay tanks may be continued unchanged.  相似文献   

6.

Objectives

Retrospective evaluation of the SPECT/CT role in the Sentinel Lymph Node identification.

Patients and methods

Thirty-two patients underwent a lymphoscintigraphy with SPECT/CT imaging. Those patients presented several cancer types (16 melanoma, one squamous cell carcinoma, three breast cancers, eight vulvar cancers, three cervical cancers).

Results

The scintigraphic detection rate was 81% with planar imaging while this rate was 89% with SPECT/CT. The SPECT/CT provided an additional quantitative information in 66% cases. Moreover, the quality of the interpretation was better in two different conditions (planar interpretation followed by routine and blinded SPECT/CT interpretation) with SPECT/CT. In our study, the false negative rate is 4.5%.

Conclusions

SPECT/CT provides quantitative and qualitative informations in the sentinel lymph node detection. Therefore, it can be a valuable tool for the surgeon to find and harvest the sentinel lymph node especially where the lymphatic drainage pattern can be unusual or hard to predict (cervical or trunk localisation). It's a new tool for preoperative detection and it can decrease the false negative rate.  相似文献   

7.
The Microlithic industries of lower Palaeolithic central Europe have been speculated to be a result of raw material availability and therefore natural constraints. However, on some sites such as Bilzingsleben and Vertessz?ll?s, raw material constraints do not apply. Clearly here has been a positive selection for small-scale tools that must have different explanations. The seemingly stable pattern of forms unrelated to raw material properties, leads to the inference that early hominin societies possessed and transmitted over generations, a defined set of behavioural norms. The paper argues that patterns of choice can be isolated within lower Palaeolithic stone tool assemblages that are distinct from patterns of ecological restraint.  相似文献   

8.
Tumor hypoxia is a major parameter of radioresistance. Hypoxia PET imaging using several radiotracers (F-Miso, FAZA, Cu-ATSM, EF5…) may help predict response to radiotherapy. Hypoxic area evaluation may also help select patients for hypoxia-targeting drugs, and thus reinforcing radiotherapy effects. Hypoxia imaging may also be fused with radiotherapy planning CT to define radioresistance areas that may be boosted by dose-painting radiotherapy. Despite several difficulties (patient positioning, organ and tumor motion, image definition…), targeting hypoxic regions within tumors is one of the most promising research strategies of modern radiotherapy.  相似文献   

9.
Myocardial 123-I-metaiodobenzylguanidine (MIBG) imaging enables the assessment of postganglionic sympathetic cardiac innervation. Recently myocardial 123-I-MIBG scintigraphy has been found to be useful to distinguishing Parkinsońs disease (PD) from other akinetic rigid syndromes. The absence of published guidelines for cardiac 123-I-MIBG imaging makes standardization of procedures among individual users of this technique even more important. Cardiac MIBG study showed markedly decreased uptake in PD, dementia with Lewy bodies (DLB) and pure autonomic failure, which is a common feature of Lewy body disease. The cardiac MIBG uptake is severely impaired even in the early disease stage. Atypical parkinsonian syndromes, including Multiple System Atrophy, Progressive Supranuclear Palsy, and other, show modest reduction of cardiac MIBG uptake. The MIBG study can be used for differentiating patients with extrapyramidal signs and dementia, and might provide useful diagnostic information to discriminate DLB and Alzheime?s disease.  相似文献   

10.

Purpose

To assess dual-tracer imaging of hybrid SPECT/CT (S/CT) compared to planar scintigraphy (S/PL) and ultrasounds (US), in preoperative localization hyperparathyroidism.

Methods

Dual tracer S/CT, S/PL and US for preoperative localization were performed in 99 patients with hyperparathyroidism. Patients with single-gland and multiple gland disease (MGD) were evaluated. For S/PL and S/CT, 15 MBq of 123I were given and 2 hours later, 555 MBq/kg of 99mTc-MIBI was injected. Images were acquired simultaneously using appropriate windows in S/PL and S/CT, then compared to US. Thus, the predicted positions were compared to the intraoperative findings and abnormal parathyroid glands were measured.

Results

Seventy-five patients underwent invasive surgery, which served as standard. Sixty-seven adenomas and 17 MGD were found on 70 patients. Sensitivity for US, S/PL and S/CT was respectively 69, 82 and 83%; and specificity was 96, 91 and 93% with an overall kappa-coefficient of 0.64, 0.73 and 0.76. US, S/PL and S/CT were correlated with the size of abnormal glands even if US remains the most accurate measuring technique. S/CT was able to predict the true position of the abnormal gland in 80% of cases.

Conclusion

Dual-isotope planar imaging and S/CT were statistically significantly superior to US imaging in sensitivity. The addition of CT to SPECT further improves parathyroid adenoma localization and predicts the size, which can help for mini-invasive surgery.  相似文献   

11.
The position of lithic industries of Chinese Paleolithic in comparison with those of other regions in the world is always a controversial topic. The typological analysis has made Chinese prehistorians reveal some variability between lithic industries of different regions of China in terms of technical tradition and industrial structure. But this recognition, based upon some morphological characters of stone artifacts, failed to define systematically the modes of production that exist in each site. To answer these problematic some new methods need to be applied. So the lithic materials from 8 Chinese sites dated from 300 ka to 50 ka B.P. were selected and analyzed by means of lithic technological analysis and a new approach for analyzing the structures of cores. This paper presents principally the analytical results of modes of débitage and revealed that the modes of débitage during this period were characterized essentially by system C (“simple débitage”) and E (discoid) and that the concept Levallois was absent during this period in technical systems of lithic production in China. The Chinese lithic industries between 300 ka and 50 ka B.P. saw some homogeneity in the scale of the continent and remarkable difference from those of other regions in the world. So a stable, continuous but independent even isolated evolution in comparison with those of other regions was observed in this period. In addition, despite of apparent homogeneity, some variability exists also between these industries.  相似文献   

12.
Implementations of the statutory UE requirements concerning ionizing radiation in the medical domain (96/29/Euratom, 13th May 1996; 97/43/Euratom, 30th June 1997) have changed quality control in medical imaging departments. In Luxembourg, the Ministry of Health and the “Union of Luxembourg Hospitals” have thus created a “Medical Physics Cell” (five Medical Physics experts). It is in charge of implementing a standardized program of Quality Assurance (QA) and radiation protection relative to patients as well as staffs, on a coordinated national basis, in all five in-hospital nuclear medicine departments of the country. The program distributes QA controls between three levels, various periodicities and degrees of expertise. It sensitizes staff and medical doctors by trainings and facilitates ISO accreditation. From 2002 to 2011, in all five in-hospital departments of nuclear medicine of a small country, image quality, radiation protection and reference values of each medical equipment were defined and implemented in a standard way. In 2011, the medical physics cell, the driving force leading to the institutionalization of the discipline within the nuclear medicine departments, is considered as a partner rather than as a control body by the teams in charge of the nuclear medicine departments.  相似文献   

13.

Objective

Set up a framework for evaluating automatic segmentation methods of tumour volumes on PET images.

Patient and methods

This study was performed with PET images of 18 patients with non-Hodgkin's lymphoma. One target lesion per patient was pointed out. Each lesion was then three times manually delineated by five experts. Four automatic methods (the application of a threshold of 42% of the maximum SUV, the MIP-based method, the Daisne et al. method and the Nestle et al. method) were evaluated by comparison with the set of manual delineations.

Results

From the manual delineations, we have concluded to a moderate intra-operator variability and to a reduced interoperator reproducibility. From statistical tests performed on various quantitative criteria, there was no significant difference between the MIP-based method, the Daisne et al. method and the Nestle et al. one. The application of a threshold of 42% of the maximum SUV appears to be less efficient.

Conclusion

This work proposes a comparison and an evaluation protocol for segmentation methods. The generated data set will be distributed online for the community to simplify the evaluation of any new method of segmentation.  相似文献   

14.
A large number of Armorican engravings (Brittany, France) have been made by “pecking”. Each hammerstone impact caused the removal of a few square millimetres of rock, leaving distinctive groove called “flake negative”. The flake negatives are an authentic “signature of percussion” which informs us about the gestures employed by the engraver. The study of the signatures of percussion makes it possible for us to identify cases of superposition or to show as yet unperceived modifications of the engraved signs or transformations that have been carried out. For example, the technological study of Dissignac (Saint-Nazaire, Loire-Atlantique) showed the case of a crook transformed into a hafted axe. This method thus represents a new way in the development of the relative chronology of neolithic engravings in Armorica.  相似文献   

15.
Positron emission tomography (PET) with FDG has a prominent role in the staging of lymphoma, including Hodgkin's lymphoma and aggressive non Hodgkin's lymphoma. Its value in the assessment of end therapy response is also well established, especially with residual masses on CT scan to differentiate between fibrosis (scar) and active tissue. International experts with the International Harmonization Project of lymphoma have proposed a set of interpretation criteria. Finally, FDG-PET looks very promising in the early response assessment; it has shown to be predictive of chemosensitivity and of therapy response. Interpretation criteria have been improved and proposed. FDG-PET usefulness is being evaluated in national and international research protocols where therapeutic strategies are based on FDG-PET results.  相似文献   

16.
Résumé Des papillons de carpocapse Cydia pomonella L., mâles et femelles séparés, sont soumis au contact des résidus secs du CGA 184'699, un inhibiteur de croissance d'insectes (ICI) et du fenoxycarb, un régulateur de croissance d'insectes (RCI). Ils sont ensuite regroupés dans boîtes non traitées pour l'accouplement et la ponte. La fécondité du carpocapse n'est pratiquement pas affectée par ce conditionnement mais sa fertilité diminue avec l'augmentation de la concentration des produits et avec la durée d'exposition. Avec le CGA 184'699, l'efficacité ovicide induite atteint environ 50% suite à un contact de trois jours avec les résidus d'un traitement à 100 mg/l, alors qu'avec le fenoxycarb elle s'élève à 87% dans les mêmes conditions. Avec le CGA 184'699, seul le contact des femelles avec les résidus provoque cette réduction de fertilité, alors que le fenoxycarb agit sur les deux sexes.
Summary Codling moth, Cydia pomonella L., males and females were exposed separately to contact with dry residues of CGA 184'699 an insect growth inhibitor (IGI) and fenoxycarb, an insect growth regulator (IGR), The sexes were then grouped together in non treated boxes for mating and egglaying. Fecundity of codling moth was little affected by this treatment but its fertility decreased with increases in the concentration of products and the duration of contact. Induced ovicidal efficacy was about 50% after three days contact with the residues of a 100 mg (a.i.)/l application of CGA 184'699, whereas the same conditions led to about 87% efficacy with fenoxycarb. With CGA 184'699, only contact by females affected egg eclosion whereas fenoxycarb acted on both sexes.
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17.
The “livre de beurre” blades debitage is classically attached to Grand-Pressigny country (Indre-et-Loire). This question is reconsidered by the autors to ligth on their knowledge of the sites and raw materials in a broadest geographic expanse: the South of Touraine and Poitou. Cultural attribution of this practice is also reconsidered and replaced in largest context.  相似文献   

18.
Do the decorated productions cover esthetics, i.e. the whole of the symbolic systems of a culture of hunters-gatherers? How to leave this glance with the aesthetic requirements that we other Westerners, pose on all things… and to exceed the debate of the artistic expressions thought from the aesthetic point of view, like “works of art” objects and “stylistics” objects? It is out of question “to make a fetish” of the productions decorated “works of art” while placing them at the starting point with our reflexion, (Studying them from a functional, technological, typological, art for art, meaningful point of view…) but to associate another of dimensions of the aesthetic experiment, i.e., the context of the decorated productions.  相似文献   

19.
Résumé La métamorphose des insectes est régie par un équilibre hormonal complexe dans lequel l'hormone juvénile (HJ) joue un rôle important. Au dernier stade larvaire, la teneur en HJ est particulièrement faible dans le corps de l'insecte. Si un régulateur de croissance d'insectes (RCI)-un mimétique de l'HJ-est appliqué à ce moment-là, la mue nymphale est pertubée provoquant des déformations morphogénétiques caractéristiques. La teneur en HJ est également très faible dans les ufs fraîchement pondus. Les traitements aux RCI peuvent par conséquent perturber le développement embryonnaire de certaines espèces et produire ainsi un effet ovicide. Depuis quelques années deux RCI-le fenoxycarb et le CGA 45 128-ont été testés pour leur activité morphogénétique sur le dernier stade larvaire de quelques ravageurs tels qu'Adoxophyes orana F.v.R., ainsi que pour leur activité ovicide sur les ufs frais de Cydia pomonella L. et Grapholita funebrana Tr. Après quelques années d'expérimentation et de commercialisation des RCI dans les vergers européens, il s'avère que l'utilisation de ces produits peu toxiques, sélectifs et peu nocifs pour la faune utile, constitue une amélioration considérable pour l'aménagement de la lutte intégrée.
Insect growth regulators (IGR), mimics of juvenile hormone, as morphological and ovicidal means of control against orchard tortricids
Summary Metamorphosis is regulated by a complex hormonal balance in which juvenile hormone (JH) plays an important part. At the last larval instar the content of JH is particularly low in the insect body. If an insect growth regulator (IGR) — a mimic of JH-is applied at this time, the pupal moult may be disturbed with the characteristic morphogenetical deformations. The JH content is also very low in freshly laid eggs. Therefore IGR treatments may disturb the embryonic development of some species and produce an ovicidal activity. During a few years two IGR-fenoxycarb and CGA 45128-were evaluated for their morphogenetical effect on the last larval instar of Adoxophyes orana F.v.R. and their ovicidal effect on freshly laid eggs of Cydia pomonella L. and Grapholita funebrana Tr. After a few years of experimentation with both compounds and of commercialisation of fenoxycarb in European orchards, IGR confirmed to present a considerable improvement in integrated pest management due to selectivity, and low mammal toxicity.
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