International Nuclear Information System (INIS)

The kinetics of "1"8F-fluorodeoxyglucose ("1"8F-FDG) in the monkey brain were monitored, and comparisons were made between the conscious state and when under ketamine and pentobarbital anesthesia. Rhesus monkeys were intravenously injected with "1"8F-FDG and followed by 60 min of PET scanning. In the conscious state, the "1"8F-FDG concentration reached a plateau 5 min after intravenous injection. Under ketamine anesthesia, the "1"8F-FDG concentration gradually increased with time in all monitored regions. At 60 min after injection, the concentration in the striatum was about 3.2 times greater than that in the conscious state, and about 4.5 times greater in the cerebral cortex. Under pentobarbital anesthesia, the "1"8F-FDG concentration in the occipital cortex was slightly lower. These findings demonstrate that "1"8F-FDG concentration in the monkey brain is significantly affected by anesthesia. The results also imply the existence of a short-term regulation ...

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"1"8F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) scan has been found to reflect tumor aggressiveness and prognosis in various types of cancer. However, pattern of FDG uptake in biliary malignancies and its clinical significance have not been studied well. The purpose of this study was to assess the additional value of "1"8F-FDG PET in differential diagnosis and prognosis of cholangiocarcinoma (CC) according to the tumor location and tumor morphology. From April 2005 to May 2008, eighty two patients (M:F=55:27, age 66.2#+-#9.6 yrs) with CC underwent "1"8F-FDG PET. For semiquantitative analysis, the maximum standardized uptake value (SUV_m_a_x) was obtained from the primary tumor. The difference of SUV_m_a_x according to the tumor location and tumor growth pattern, such as scirrhous type, nodular type, polypoid type were compared. Overall sensitivity of PET scan was 81.7% in CC. ...

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IntroductionCopper(II)-diacetyl-bis(N4-methylthiosemicarbazone), or Cu-ATSM, a hypoxia imaging agent, has been shown to be predictive of response to traditional cancer therapies in patients with a wide range of tumors. It is known that the environment of the tumor results in a myriad of physiological consequences, including hypoxia, alterations in metabolism and proliferation. In an effort to better characterize the relationships between Cu-ATSM and other prominent radiopharmaceuticals, this current study was undertaken to compare the regional distribution of 64Cu-ATSM with [18F]fluoromisonidazole (18F-FMISO), [18F]fluoro-2-deoxy-d-glucose (18F-FDG) and [18F]fluorothymidine (18F-FLT) in 9L tumors.MethodsTaking advantage of the different half-life of 18F (t1/2=110 min) in comparison to 64Cu...

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The Subcommittee for Surveillance of Nuclear Medicine Practice has implemented a survey for actual nuclear medicine practice in Japan every 5 years. This article reports on the third survey implemented during a one-month period in June 1992. Questionnaires were sent to all 1256 facilities employing radiopharmaceuticals in routine practice, and 1162 (92.5%) answered. In vivo nuclear medicine examinations per day were performed in 6600 cases. SPECT accounted for 19.4%, as compared with 7.1% in the 1987 survey. According to organs, the frequency of examination for the cerebrospinal region was 3.2 and 2.2 times higher than that in the 1982 and 1987 surveys, respectively, whereas for the thyroid gland it was 0.6-fold and 0.7-fold that of these surveys. The proportion of bone scintigraphy was the highest (24.5%), followed by tumor scintigraphy (14.1%) and myocardial scintigraphy (11.9%). The frequency of myocardial and cerebral blood flow scintigraphy was dramatically increased as compared ...

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Targeted studies completed include the evaluation of tritiated N-0437, evaluation of /sup 35/S-cysteamine, evaluation of /sup 18/F-FDG and initiation of synthetic efforts towards the synthesis of iodinated N-0437 and pergolide analogs. The direction of the project has been changed due to several factors which include the decided lack of favorable experimental results, the excellence of results using muscarinic receptor ligands in pituitary, brain and heart and the contention of the DOE review panel that the original grant proposal was based on flawed assumptions together with their perceived lack of importance to pituitary imaging. In the final year of this grant, three studies will be completed. The first study is the continuation of synthetic efforts to prepare iodinated N-0437 and pergolide analogs for possible use as brain imaging agents. The second study is directed towards completion of biochemical evaluation of various muscarinic ...

ScienceCinema

...global warming ...

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Positron-emission tomography (PET) and PET/CT (computed tomography) are becoming increasingly important for diagnosis and treatment of cancer. Clinically relevant changes can sometimes be seen on PET that are not seen on other imaging modalities. However, PET is not suitable for guiding biopsy as the images are not obtained in real-time. Therefore, our research group has begun developing a concept for PET/CT-guided interventional procedures. This paper presents the rationale for this concept, outlines our research plan, and includes an initial study to evaluate the relative sensitivity of CT and PET/CT in detecting suspicious lesions. (orig.)

KoreaScience (Korea)

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International Nuclear Information System (INIS)

Positron emission tomography (PET) and X-ray computed tomography (CT) performed with PET/CT cameras allow us to obtain concurrently information on the presence and degree of alterations of myocardial perfusion and metabolism and on coronary arteries calcification. Furthermore, by gated myocardial perfusion studies, PET may provide crucial information on regional coronary blood flow reserve and endothelial dysfunction. A number of recent papers provide some insight on the potential of PET/CT in cardiology and in the assessment of various cardiovascular diseases including various types of vasculitis and metabolic diseases.

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We investigated the efficacy of combined FDG-PET/CT imaging for the diagnosis of small-size uveal melanomas and the feasibility of combining separate, high-resolution (HR) FDG-PET with MRI for its improved localization and detection. Patients, methods: 3 patients with small-size uveal melanomas (0.2-1.5 ml) were imaged on a combined whole-body PET/CT, a HR brain-PET, and a 1.5 T MRI. Static, contrast-enhanced FDG-PET/CT imaging was performed of head and torso with CT contrast enhancement. HR PET imaging was performed in dynamic mode 0-180 min post-injection of FDG. MRI imaging was performed using a high-resolution small-loop-coil placed over the eye in question with T2-3D-TSE and T1-3D-SE with 18 ml Gd-contrast. Patients had their eyes shaded during the scans. Lesion visibility on high-resolution FDGPET images was graded for confidence: 1: none, 2: suggestive, ...

Science.gov (United States)

... H1+80 Remaining H +82 Remaining H+56 IlemaJntng ,H+77 Remaining. Aa pct c/m pct mr/hr pet mr/hr pet ... mr/hr avg. pct c/rnh pt pa pct ...

UK PubMed Central (United Kingdom)

Multimodality imaging with PET/CT and SPECT/CT has become commonplace in clinical practice and in preclinical and basic medical research. Do other combinations of imaging modalities have a similar...Full Text Available

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Integration of positron emission tomography (PET) and magnetic resonance (MR) has become a topic of increasing interest to the imaging community over the past two years. In this text, the authors attempt to distinguish facts from fiction concerning such integrated systems. Analysis of existing information of combined imaging on existing brain PET/MR systems and imaging experience with PET-computed tomography (CT) is reviewed. Various types of system integration of PET and MR are discussed with completely independent systems on one hand and completely integrated systems with the possibility of simultaneous data acquisition on the other hand. Furthermore, it is discussed, what simultaneous data acquisition with nuclear imaging systems combined with MR or CT really means, as technical simultaneity may not be relevant in light of the pharmacokinetics of the nuclear tracers used. The authors conclude that ...

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Positron emission tomography (PET) and magnetic resonance imaging (MRI) studies were performed on a case of neuro-Behcet's syndrome. In accordance with the clinical signs, FDG PET (using /sup 18/F-labeled 2-F-2'-desoxyglucose) revealed disseminated storage defects in the cerebrum and cerebellum. Focal regions of enhanced signal intensity were demonstrated in the parietal white matter of the cerebrum in T2-weighted images and in the brain stem by MRI. (orig.).

International Nuclear Information System (INIS)

Positron emission tomography (PET) is a fully quantitative technology for imaging metabolic pathways and dynamic processes in vivo. Attenuation correction of raw PET data is a prerequisite for quantification and is typically based on separate transmission measurements. In PET/CT attenuation correction, however, is performed routinely based on the available CT transmission data. Recently, combined PET/magnetic resonance (MR) has been proposed as a viable alternative to PET/CT. Current concepts of PET/MRI do not include CT-like transmission sources and, therefore, alternative methods of PET attenuation correction must be found. This article reviews existing approaches to MR-based attenuation correction (MR-AC). Most groups have proposed MR-AC algorithms for brain PET studies and more recently also for torso ...

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Breast Cancer

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Flame retardant recycled PET blends containing PC and triphenyl phosphite (TPP) have been designed using the following sequential processing strategy: PET and PC are first melt blended with a transesterification catalyst, allowing the compatibilisation of the blend, before adding TPP. The presence of this last component was shown to stop the transesterification reaction between PET and PC, avoiding chain breaking. In addition, TPP acts as a chain extender of PET, allowing the average chain length to be increased. The optimized blends obtained present "V-0" UL94 rating due to a better thermal stability leading to low flammability and to the development of an important, stable and covering char layer, resulting in self-extinguishability and very low Heat Release Rates during combustion.

International Nuclear Information System (INIS)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high magnetic fields. Initial pilot studies with ...

International Nuclear Information System (INIS)

To evaluate the role of positron emission tomography-computed tomography (PET-CT) in staging and determining early treatment response to chemotherapy in children with neuroblastoma (NB) and its correlation with the final outcome. Patients and Methods: Seventeen patients of NB with mean age of 51.5 months (age range 2-132 months; 14 males, 3 females) underwent serial "1"8F-fluorodeoxyglucose (FDG) PET-CT imaging. All 17 patients were for staging before any treatment. Twelve of 17 patients underwent "1"3"1I meta-iodobezylguanidine (MIBG) scan and bone scan. MIBG uptake was seen in the primary lesion in 11/12 patients. MIBG uptake in bones was seen in 3/12 patients. All bone lesions were concordant on MIBG and bone scan. Early response to chemotherapy was evaluated after two cycles using PET-CT. A 30% reduction in longest diameter was taken as cut-off value for response on CT based on the response evaluation criteria in solid ...

International Nuclear Information System (INIS)

Colerectal cancer (CRC) is the second commonest cancer in the Western World. Successful treatment relies significantly on accurate detection and staging of primary disease as well as the early identification of the presence and extent of recurrence. Morphological imaging techniques, particularly computed tomography (CT), are well established and widely available to carry out these tasks in addition to predicting and monitoring response to therapy. This review analyses the current inadequacies for imaging CRC and critically assesses the potential role of functional imaging with positron emission tomography (PET). It was reviewed the current literature, to use the experience from the firs 1000 PET studies carried out at the institution and the perspective of surgical colleagues. It was found little evidence for the use of 2-["1"8F]fluoro-2-deoxy-D-glucose (FDG)-PET for screening asymptomatic individuals and current modalities ...

British Library Electronic Table of Contents (United Kingdom)

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest...

British Library Electronic Table of Contents (United Kingdom)

Summation Copper-64 (T1/2?=?12.7 hours; ?+, 0.653?MeV [17.8 %]; ??, 0.579?MeV [38.4 %]) has decay characteristics that allow for positron emission tomography (PET) imaging and targeted radiotherapy of cancer. The well-established coordination chemistry of copper allows for its reaction with a wide variety of chelator systems that can potentially be linked to peptides and other biologically relevant small molecules, antibodies, proteins, and nanoparticles. The 12.7-hours half-life of 64Cu provides the flexibility to image both smaller molecules and larger, slower clearing proteins and nanoparticles. In a practical sense, the radionuclide or the 64Cu-radiopharmaceuticals can be easily shipped for PET imaging studies at sites remote to the production facility. Due to the versatility of 64Cu, ...

UK PubMed Central (United Kingdom)

According to world statistics, dogs and cats are the species that owners most frequently seek assistance with potential poisonings, accounting 95–98% of all reported animal cases. Exposures...Full Text Available

International Nuclear Information System (INIS)

Brain glucose metabolism was evaluated in four patients with acquired immunodeficiency syndrome (AIDS) dementia complex using ["1"8F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) scans at the beginning of therapy with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine), and later in the course of therapy. In two patients, baseline, large focal cortical abnormalities of glucose utilization were reversed during the course of therapy. In the other two patients, the initial PET study did not reveal pronounced focal alterations, while the post-treatment scans showed markedly increased cortical glucose metabolism. The improved cortical glucose utilization was accompanied in all patients by immunologic and neurologic improvement. PET-FDG studies can detect cortical metabolic abnormalities associated with AIDS dementia complex, and may be used to monitor the metabolic improvement in response to AZT treatment.

UK PubMed Central (United Kingdom)

The ability to achieve tumor selective expression of therapeutic genes is an area that needs improvement for cancer gene therapy to be successful. One approach to address this is through the...Full Text Available

UK PubMed Central (United Kingdom)

We report on a high resolution, monolithic crystal PET detector design concept that provides depth of interaction (DOI) positioning within the crystal. Our design utilizes a novel sensor on...Full Text Available

International Nuclear Information System (INIS)

In cases of obstructive colorectal cancer (CRC), preoperative diagnosis of the proximal lesion is often difficult when the primary lesion impedes the passage of the endoscope. The aim of this study was to evaluate the usefulness of fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in such cases. A total of 52 obstructive CRC patients who underwent preoperative FDG-PET and subsequent surgical resection were retrospectively reviewed. The correlation between characteristics of the proximal lesion and FDG-PET findings was analyzed statistically. There was a significant correlation between the proximal lesion size and the maximum standardized uptake value (P=0.00016). Abnormal FDG accumulation in the proximal colon indicated the existence of proximal cancer or adenoma with a sensitivity of 50% and a specificity of 100%. There was a significant difference in the distribution of tumor size between the cases ...

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The electrical conductivity of ion-implanted films of Nylon 66, Polypropylene (PP), Poly(tetrafluoroethylene) (Teflon) and mainly Poly (ethylene terephthalate) (PET) was determined by DC measurements at voltages up to 4500 V and compared with the corresponding values of pristine films. Measurements were made at 21/sup 0/C +/- 1/sup 0/C and 65 +/- 2% RH. The electrical conductivity of PET films implanted with F/sup +/, Ar/sup +/, or As/sup +/ ions at energies of 50 keV increases by seven orders of magnitude as the fluence increases from 1 x 10/sup 18/ to 1 x 10/sup 20/ ions/m/sup 2/. The conductivity of films implanted with As/sup +/ was approximately one order greater than those implanted with Ar/sup +/, which in turn was approximately one-half order greater than those implanted with F/sup +/. The conductivity of the most conductive film approx.1 S/m) was almost 14 orders of magnitude greater than the pristine PET film. ...

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The aim of this work is the evaluation of biodistribution and radiation dosimetry of a cocaine analog, the N-(3-iodo-prop-2E-enyl)-2beta-carbo-methoxy-3beta-(4-methyl-phenyl) nor-tropane (PE2I), labeled with carbon 11 ([{sup 11}C]PE2I). The [{sup 11}C]PE2I is a selective radioligand for imaging neuronal dopamine transporter (DAT) with positron emission tomography (PET). The DAT is a membrane-bound pre synaptically located protein that regulates the concentration of dopamine at nerve terminals. DAT radioligands are often used to evaluate the progression of Parkinson's disease or the efficiency of neuro-protective therapeutics and, typically, these studies required several successive PET scans. (author)

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Image registrations that are based on similarity measures simply adjust the parameters of an appropriate spatial transformation model until the similarity measure reaches an optimum. The numerous similarity measures that have been proposed in the past are differently sensitive to imaging modality, image content and differences in the image content, selection of the floating and target image, partial image overlap, etc. In this paper, we evaluate and compare 12 similarity measures for the rigid registration. To study the impact of different imaging modalities on the behavior of similarity measures, we have used 16 CT/MR and 6 PET/MR image pairs with known 'gold standard' registrations. The results for the PET/MR registration and for the registration of CT to both rectified and unrectified MR images indicate that mutual information, normalized mutual information and the entropy correlation coefficient are the most accurate ...

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A beta microprobe was successfully applied to monitor arterial input function for quantification of regional cerebral blood flow (rCBF) in the monkey brain with {sup 15}O-water and positron emission tomography (PET). The sensitivity of the probe was approximately 0.83 to 1.67 cps/kBq/ml depending on the studies. A preliminary study was performed to find a suitable use and to evaluate the performance of the system and data analysis procedure. The results showed that dispersion correction of measured input function was unnecessary if microprobes were connected directly to the arterial catheter. Then multiple CBF measurements were done in three monkeys under anesthesia. Identical regions of interest were placed with the aid of magnetic resonance imaging (MRI) of each monkey and rCBF values were estimated. Estimated rCBFs were reproducible for several measurements. The mean CBF value for a pentobarbital anesthetized monkey was 46.0 ml/min/100 g (PaCO{sub 2}=46.3 mmHg). ...

International Nuclear Information System (INIS)

Aim: There has been a great demand for developments of the radioligands to visualize the N-methyl-D-aspartate (NMDA) receptors by PET/SPECT. We have recently synthesized two C-11 labeled antagonists for the glycine-binding site on NMDA receptors. The aim of this work is to examine for their in vitro and in vivo binding characteristics, and to evaluate their potentials as PET radioligands for the NMDA receptors. Materials and methods: Two C-11 labeled 4-hydroxy-2-quinolones (1 and 2) were synthesized by conventional methylation of the corresponding phenols with ["1"1C]methyl iodide. In vitro and ex vivo quantitative autoradiographs with imaging plate, as well as animal PET, were employed in order to evaluate their in vitro and in vivo binding to the NMDA receptors. Results: The compound 1 showed the specific binding to rat brain slices with higher localization in the hippocampus and cerebral cortex than in the cerebellum. ...

British Library Electronic Table of Contents (United Kingdom)

Rationale Receptor occupancy study has been performed to evaluate pharmacokinetic profiles in new antipsychotic drug development. While these findings highlight the value of positron emission tomography (PET) for dose-finding study, what is unclear is if it is necessary to conduct these studies in patients with schizophrenia or whether studies in healthy volunteers are adequate. Objectives To determine if it is necessary to conduct dopamine receptor occupancy studies in patients with schizophrenia or whether studies in healthy volunteers are adequate for dose-finding study, we compared the concentration?occupancy relationship in terms of EC50 between patients and healthy volunteers. Methods Ten healthy volunteers and eight patients with schizophrenia participated in the study. We measured ...

British Library Electronic Table of Contents (United Kingdom)

In this study, Nylon 66/Polyester (Ny 66/PET) hybrid cord design and production was investigated to obtain new cord with better performance than conventional cord. The factors affecting cord properties and cord production process were examined. Taguchi design of experiment method was implemented in order to minimize the required number of experiments. Different sets of 4 reference cords conventionally used in tyre industry were prepared and resorcinol-formaldehyde-latex (RFL) treated in order to make a comparison of performance. Mechanical and thermal properties of hybrid cords were measured and compared with the values of reference cords. It was found that the twist level of high modulus PET component in the hybrid cords should be the same or above of the nylon in order to obtain maximum ...

International Nuclear Information System (INIS)

The authors used studies of local cerebral metabolic rate for glucose (LCMRGlc) to examine development of cerebral organization in 5 days to 1 year old children. A group (n=8) of infants with diverse pediatric disorders allowed investigation of developmental changes in LCMRGlc, while also providing relevant clinical management information. Patients consisted of questionable and definite neonatal seizures, cerebral embolism from cardiac sources, and otherwise normal infants with facial nevi with consideration of Sturge-Weber. Gradual increase in cortical LCMRGlc coincides with suppression of intrinsic subcortical reflexes present in all newborns. Two retarded children (2 years old) showed LCMRGlc developmental patterns of a few days old, which corresponded to their functional and mental status. These studies illustrate great potential of PET to study normal and altered states of human brain development.

UK PubMed Central (United Kingdom)

Translocator protein (TSPO) is upregulated in activated microglia and thus can serve as a marker of neuroinflammation. Recently, a novel radioligand, ¹¹C-N,N-diethyl-2-[2-(4-methoxyphenyl)-5,7-dimethyl-pyrazolo[1,5-a]pyrimidin-3-yl]-acetamide...Full Text Available

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Research is described in the development of organometallic reagents in which the boron was attached to a nonreactive organic or inorganic matrix such as polystyrene, silica, or alumina. We developed the synthesis of oxygen-15 labelled butanol, which has been found to be a valuable blood flow agent in humans. We have also developed a series of polymeric borane derivatives which were used to prepare nitrogen-13 labelled amines.

British Library Electronic Table of Contents (United Kingdom)

Combination agents comprising two different pharmacophores with the same biological target have the potential to show additive or synergistic activity. Bis(thiosemicarbazonato)copper(II) complexes (e.g. 64Cu-ATSM) and nitroimidazoles (e.g. 18F-MISO) are classes of tracer used for the delineation of tumor hypoxia by positron emission tomography (PET). Three nitroimidazole-bis(thiosemicarbazonato)copper(II) conjugates were produced in order to investigate their potential as combination hypoxia imaging agents. Two were derived from the known bifunctional bis(thiosemicarbazone) H2ATSM/A and the third from the new precursor diacetyl-2-(4-N-methyl-3-thiosemicarbazone)-3-(4-N-ethylamino-3-thiosem icarbazone) - H2ATSM/en. Oxygen-dependent uptake studies were performed using the 64Cu radiolabelled ...

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Modern imaging technologies visualize different aspects of disease in a non-invasive way. Considerable progress has been made in the fusion of images from different imaging modalities using software approaches. One goal of fusion software is to align anatomical and functional images and allow improved spatial localization of abnormalities. The resulting correlation of the anatomical and functional images may clarify the nature of the abnormality and help diagnose or stage the underlying disease. Whereas successful image fusion software has been developed for the brain, only limited success has been achieved for image alignment in other parts of the body. The development and current status of alternative approaches are presented. Dual-modality imaging is described with devices where two modalities are combined and mounted in a single gantry. The use of existing scanner technology ensures that no compromises are made in the clinical efficacy of either the anatomical or functional imaging ...

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A new coumarin-based sensor molecule (L1) has been synthesized and this was found to bind calcium and magnesium ions more effectively as compared to other alkali/alkaline earth/lanthanide and certain transition metal ions. A significant enhancement in fluorescence intensity was observed on binding to Ca2+ and Mg2+ ions; while a minor quenching was observed for weakly bound Hg2+, Ni2+, Fe3+, and Co2+ ions. PET process, coupled with the ICT process, is proposed to explain the observed spectral response.

International Nuclear Information System (INIS)

During the last decade there was a growing interest on the application of Positron Emission Tomography, PET, techniques to Breast Imaging. More recently, preliminary results suggested the use of dedicated devices to Breast Imaging using the same technique, the so-called Positron Emission Mammography cameras, PEM. In this article we review the arguments leading to a dedicated instrument. Based on these arguments we describe the concept of a PEM camera under development within the Crystal Clear Collaboration and the first results of its expected performance in terms of sensitivity and position resolution.

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A major factor for the achievement of the desirable performance, efficiency and lifetime of flexible organic electronic devices is the optimization of the encapsulation layers that protect the device active layers by atmospheric gas molecule permeation. The active layers consisted of small molecule and/or polymer organic semiconductors as well as the organic conductors need to be encapsulated into a transparent medium that will provide the necessary protection and maintain their charge generation and transport characteristics. The encapsulation layers are generally consisted of inorganic thin films (silicon oxide-SiO{sub x} and aluminium oxide-AlO{sub x}) deposited onto the polymeric substrates, such as PolyEthylene Terephthalate (PET). In this work, in situ and real-time Spectroscopic Ellipsometry in the ultraviolet spectral region has been implemented in order to investigate the growth of inorganic SiO{sub x} and AlO{sub x} nano-layers onto ...

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For Monte Carlo simulations to be used as an alternative solution to perform scatter correction, accurate modelling of the scanner as well as speed is paramount. General-purpose Monte Carlo packages (Geant4, EGS, MCNP) allow a detailed description of the scanner but are not efficient at simulating voxel-based geometries (patient images). On the other hand, dedicated codes (SimSET, PETSIM) will perform well for voxel-based objects but will be poor in their capacity of simulating complex geometries such as a PET scanner. The approach adopted in this work was to couple a dedicated code (SimSET) with a general-purpose package (Geant4) to have the efficiency of the former and the capabilities of the latter. The combined SimSET+Geant4 code (SimG4) was assessed on the GE Advance PET scanner and compared to the use of SimSET only. A better description of the resolution and sensitivity of the scanner and of the scatter fraction was obtained with SimG4. ...

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Background: Cu-diacetyl-bis(N{sup 4}-methylthiosemicarbazone) [Cu-ATSM], although excellent for oncology applications, may not be suitable for delineating cardiovascular or neurological hypoxia. For this reason, new Cu hypoxia positron emission tomography (PET) imaging agents are being examined to search for a higher selectivity for hypoxic or ischemic tissue at higher oxygen concentrations found in these tissues. Two approaches are to increase alkylation or to replace the sulfur atoms with selenium, resulting in the formation of selenosemicarbazones. Methods: Three {sup 64}Cu-labeled selenosemicarbazone complexes were synthesized and one was screened for hypoxia selectivity in vitro using EMT-6 mouse mammary carcinoma cells. Rodent biodistribution and small animal PET images were obtained from BALB/c mice implanted with EMT-6 tumors. One alkylated thiosemicarbazone was synthesized and examined. Results: Of the three bis(selenosemicarbazone) ...

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Various control procedures have been suggested for reducing foodborne infectious diseases. Receiving considerable attention is irradiation. This report estimates the medical and wage (or productivity) benefits associated with prevention of five human diseases transmitted by beef, pork, and chicken. (These diseases can also be transmitted by other vectors, such as eggs, milk, and pets. But these sources are not included in the analysis.) All of these foodborne infectious diseases - salmonellosis, campylobacteriosis, trichinosis, tapeworm, and toxoplasmosis - could be significantly reduced by irradiating meat and poultry. The Food and Drug Administration (FDA) has just approved irradiation of pork to prevent trichinosis (50FR 29658-59) and is considering approval of irradiation of chicken to kill Salmonella. 22 references.

British Library Electronic Table of Contents (United Kingdom)

Nonfunctioning pancreatic endocrine tumors (PETs) are rare and generally asymptomatic. A 68-year-old woman who had refused treatment for a pancreatic mass, revealed by ultrasonography to be 55 mm in diameter, was referred to us again 29 months later with jaundice. Investigations showed an 82-mm tumor in the head of pancreas, exposed from the papilla of Vater to the duodenal lumen. After biliary decompression and drainage, we performed pancreatoduodenectomy with resection of the portal vein and superior mesenteric vein, followed by reconstruction using a cylindrically customized autologous graft harvested from the right ovarian vein. The tumor was resected curatively. Microscopically, it consisted of trabecular and ribbon-like arrangement of neoplastic cells. Immunohistochemical staining wa...

International Nuclear Information System (INIS)

The central benzodiazepine receptor tracer [N-methyl-"1"1C]iomazenil (Ro 16-0154) was synthesized by alkylation of the desmethyl precursor noriomazenil with ["1"1C]methyl iodide. The ["1"1C]CH_3I (prepared by reduction of ["1"1C]CO_2 with LiAlH_4 followed by reaction with HI) was reacted with noriomazenil inN,N -dimethylformamide and Bu_4N"+OH"- for 1 min at 80 deg. C and purified by HPLC (C_1_8, 34% CH_3CN/H_2O, 7 mL/min). The product was obtained with synthesis time 35 #+-# 5 min (mean #+-# SD, n = 7), radiochemical yield (EOB) 36 #+-# 16%, radiochemical purity 99 #+-# 1%, and specific activity 5100 #+-# 2800 mCi/#mu#mol. Absorbed radiation doses were calculated from previously acquired human biodistribution data. The urinary bladder wall received the highest dose (0.099 mGy/MBq) for 4.8 h voiding interval and the effective dose equivalent was 0.015 mSv/MBq. After i.v. injection of ["1"1C]iomazenil in an adult baboon or healthy human volunteer, radioactivity accumulated in the cortex ...

International Nuclear Information System (INIS)

Introduction: Development of agonist positron emission tomography (PET) radioligands for the 5-HT neurotransmitter system is an important target to enable the understanding of human 5-HT function in vivo. ["1"1C]CUMI-101, proposed as the first 5-HT_1_A receptor agonist PET ligand, has been reported to behave as a potent 5-HT_1_A agonist in a cellular system stably expressing human recombinant 5-HT_1_A receptors. In this study, we investigate the agonist properties of CUMI-101 in rat brain tissue. Methods: ["3"5S]-GTP#gamma#S binding studies were used to determine receptor function in HEK (human embryonic kidney) 293 cells transfected with human recombinant 5-HT_1_A receptors and in rat cortex and rat hippocampal tissue, following administration of CUMI-101 and standard 5-HT1A antagonists (5-HT, 5-CT and 8-OH-DPAT). Results: CUMI-101 behaved as an agonist at human recombinant 5-HT_1_A receptors (pEC_5_0 9.2). However, CUMI-101 did not show ...

International Nuclear Information System (INIS)

Differentiated thyroid cancer (DTC) has variable degree of F-18 FDG avidity. The purpose of this study was to evaluate the relationship between F-18 FDG uptake and pathological or immunohistochemical features of DTC. DTC patients who underwent both pre-operative F-18 FDG PET/CT scan and surgery were included in the study. Maximum standardized uptake values (SUVmax) of primary tumor were calculated. If the primary tumor showed no perceptibly increased F-18 FDG uptake, region of interest was drawn based on finding of CT portion of the PET/CT images. Pathological and immunohistochemical markers such as presence of lymph node (LN) metastasis and underlying thyroiditis, tumor size, Ki-67 labeling index, expressions of EGFR, COX-2, and Galectin-3 were evaluated. Total of 106 patients was included (102 papillary carcinomas, 4 follicular carcinomas). The mean SUVmax of the large tumors (above 1 cm) was significantly higher than the mean SUVmax of small ...

International Nuclear Information System (INIS)

A curved crystal X-ray spectrographs of reflection type spherical geometry was required based on the Johann scheme. Due to their high efficiency and resolution, X-ray spectrographs of focusing spectrograph spatial resolution are suitable for detecting weak X-ray spectra in spectrometers for laser fusion research. Spherically bent mica crystal with a radius of curvature of 380 mm was used in the spectrometer. The Bragg angle of the crystal analyzer was 51 degree. The image plate was employed to obtain high spatial resolution and a narrow spectral band width, with an effective area of 30 mm x 80 mm. The designed optical path of the X-ray spectrometer beam was 980 mm long from the source to the crystal and the detector. The first experiment was carried out at the 20 J energy laser facility of Research Center of Laser Fusion, China Academy of Engineering Physics. X-ray spectra in an absolute intensity scale were obtained from Al laser-produced plasmas created by laser energies 6.78 J, with ...

Energy Technology Data Exchange (ETDEWEB)

The ink jet printing technology is a relatively novel technique in development of organic electronic devices. The technique consists of working out depositions of organic layers by a piezo-based ink jet printer. In this work polymer conducting films deposited by ink jet printing technique on different plastic substrates has been demonstrated. The poly(3,4-ethylenedioxythiofene)/poly(4-styrenesulfonate) [PEDOT/PSS] and glycerol-modified PEDOT/PSS [G-PEDOT/PSS] were used like conducting inks to be applied on polyester and polyethylene terephthalate (PET) substrates. By means of the change of substrate associated to the deposition number or type of polymer ink used for printing of the conducting films, the sheet resistance can be modified. Such a behavior suggests that plastic substrate fulfills an important role for the changing of sheet resistance of the PEDOT/PSS and G-PEDOT/PSS films made by ink jet printing technique. Films obtained from this technique on ...

British Library Electronic Table of Contents (United Kingdom)

The preS2 antigens of hepatitis B virus (HBV), which causes a serious health problem in the world, have been implicated in hepatocyte cell binding and viral penetration. Therefore, the importance of antibody production against preS2 antigen for early diagnosis of HBV has been well established. In this study, the recombinant HBV preS2 single chain variable fragment (scFv) antibody was successfully expressed in E. coli with the novel cold shock vector (pCold) under the cspA promoter, and its expression level was compared with the pET vector under the T7 promoter. Additionally, a host with an oxidizing cytoplasm, E. coli trxB/gor double mutant, was used to improve the soluble expression. The anti-HBV preS2 scFv using pCold vector was successfully expressed in a soluble and functional form in ...

Energy Technology Data Exchange (ETDEWEB)

The effect of atmospheric pressure on tracking resistance of organic insulating materials were investigated in the range of 500 to 1007 hPa. The tracking resistance for Polycarbonate (PC), Modified Polyphenylene Oxide (M-PPO) and Paper Base Phenolic Resin Laminate (PL) increase with the decrease in atmospheric pressure. The scintillating discharges on these samples surface lead to the ignition. The tracking failure on these results from the ignition on the surface. For Polybutylene Terephthalate (PBT) and Polyethylene Terephthalate (PET), the tracking resistance decrease with the decrease in atmospheric pressure. The discharges observed on the these surface are the glow-like. The discharge area spreads on the surface between the electrodes at the lower pressure. The failure on this group results from the carbonization by the discharges on the surface. However, the tracking resistance for Unsaturated Polyester Resins (UP) has no significant dependence on lower ...

CERN Document Server

The idea to couple the Treatment Planning System (TPS) to the information on the real boron distribution in the patient is the main added value of the new methodology set-up at DIMNP of University of Pisa, in collaboration with the JRC of Petten (NL). The methodology has been implemented in the new TPS, called BDTPS (Boron Distribution Treatment Planning System), which takes into account the actual boron distribution in the patient brain, while the standard TPS assumes a uniform boron distribution, absolutely far from the reality. Nowadays, Positron Emission Tomography (PET) is able to provide this in vivo information. The new TPS, based on the Monte Carlo technique, has been validated comparing the main BNCT parameters (thermal flux, boron dose, etc.) as measured during the irradiation of a special heterogeneous boron phantom (HEBOM), ad hoc designed, as calculated by the BDTPS and by the standard TPS SERA. An evident SERA overestimation of the thermal neutron ...

DEFF Research Database (Denmark)

The coupling between cerebral metabolic rate of oxygen (CMRO2) and blood flow (CBF) in response to visual stimulation was evaluated by means of a model of oxygen delivery. The model predicted a nonlinear relationship between stimulus-evoked changes of oxygen consumption and blood flow. The magnitude of the CMRO2/CBF ratio index (IO2) was used to indicate the degree of flow-metabolism coupling prevailing in specific areas of the brain during physiological stimulation. Therefore, the index provided a measure of the blood oxygenation level dependent (BOLD) magnetic resonance contrast. To evaluate the changes of IO2 in response to visual stimulation, the model was applied to the effect of a changing flicker rate of a visual stimulus on the magnitudes of CBF, CMRO2, and oxygen diffusion capacity, in the human brain. Positron emission tomography (PET) was used to measure the CBF and the CMRO2 in 12 healthy volunteers who viewed a cross-hair (baseline) or a yellow-blue ...

International Nuclear Information System (INIS)

Primary standardisation was performed on a solution of "1"8F using the 4#pi##beta#-#gamma# coincidence counting efficiency-tracing extrapolation method with "6"0Co used as a tracer nuclide. The result was used to calibrate the ANSTO secondary standard ionisation chamber which is used to disseminate Australian activity standards for gamma emitters. Using the secondary activity standard for "1"8F, the Capintec CRC-712M dose calibrator at the Australian National Medical Cyclotron (NMC) Positron Emission Tomography (PET) Quality Control (QC) Section was calibrated. The dial setting number recommended by the manufacturer for the measurement of the activity of "1"8F is 439. In this work, the dial setting numbers for the activity measurement of the solution of "1"8F in Wheaton vials were experimentally determined to be 443+/-12, 446+/-12, 459+/-11, 473+/-15 for 0.1, 1, 4.5 and 9ml solution volumes, respectively. The uncertainties given above are expanded uncertainties ...

Energy Technology Data Exchange (ETDEWEB)

The transport of radon in concrete takes place through the complicated network of interconnected pores that is, at any time, the result of the process of hydration of cement and of moisture distribution and transport. Initially the microstructure of concrete depends on the mix proportions and curing conditions, its time-evolution being conditioned by its surrounding environment. Radon transport will be consequently a function of time, as it is influenced by the changing microstructure (total porosity and its distribution) and by the amount and distribution of the moisture contained in the pore system. A selection of information from the large amount of literature available on concrete is presented in chapter 2. A model that describes the process of hydration, of microstructure development and of moisture transport is presented in chapter 3. The physics of radon diffusion in homogeneous porous materials is outlined in chapter 4. The coupling of the numerical implementation of the ...

International Nuclear Information System (INIS)

Full text: Radiotherapy treatment planning (RTP) relies heavily on medical imaging. Until recently, the most important planning tool was the treatment simulator. The kilovoltage radiographic capabilities in a treatment simulator enabled the boundaries of treatment fields to be visualized with respect to bony anatomic landmarks. Perhaps the most important advance in treatment planning in recent years is the ability to visualize the passage of the beams with respect to a more accurate geometrical representation of the tumor and other soft tissue structures. This 'virtual simulation' uses a computer-based representation of a patient to determine the extent of the disease and the location of radiation sensitive normal tissue. Computer tomographic (CT) imaging produces a high-resolution three-dimensional representation of anatomy that can be correlated with other image sets such as magnetic resonance images (MRI) of function. Positron emission tomographic (PET) imaging ...

Energy Technology Data Exchange (ETDEWEB)

Aim: Today, MRI is an integral part of the presurgical evaluation of patients suffering from partial epilepsy. These patients frequently show focal morphological abnormalities with potential epileptogenic character and surgical resection of these lesions is associated with superior postsurgical outcome as to seizure frequency. Apart from easily detectable defects, such as post-traumatic lesions or cerebral infarction, as wide variety of mainly small abnormalities can be detected using MRI. Methods: In this study, 484 patients suffering from partial epilepsy of temporal or frontal onset were evaluated for the incidence of different lesions in this population. Results: All lesions found were included without evaluating their potential epileptogenicity, which remains to be proven using other procedures (EEG, SPECT, PET, etc.). Involvement of the hippocampal formation was a major finding in temporal lobe epilepsy, which could be detected as sclerosis (T2w-images), ...