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Sample records for clinical positron emission

  1. Positron emission tomography clinical practice

    CERN Document Server

    Valk, Peter E; Bailey, Dale L; Townsend, David W; Maisey, Michael N

    2006-01-01

    This book provides a contemporary reference to the science, technology and clinical applications of PET and PET/CT. The opening chapters summarize the scientific aspects of PET and PET/CT including physics, instrumentation, radiation dosimetry and radiation protection. A chapter on normal variants in FDG PET imaging serves as an introduction to the clinical chapters, which cover oncology applications and have been updated to include the impact of FDG PET/CT imaging in oncology. The book concludes with chapters on the use of PET and PET/CT in cardiology and neurology and PET imaging of infectio

  2. Introducing Positron Emission Tomography (PET) in Clinical Practice

    OpenAIRE

    Janevik-Ivanovska, Emilija; Avmedovski, Fatmir; Yamamoto, Mayumi; Bhonsle, Uday

    2009-01-01

    Positron emission tomography (PET) is a major diagnostic imaging technique predominantly used in determining the presence and severity of cancers, neurological conditions, and cardiovascular diseases. It is currently the most effective way to check for cancer recurrences and it offers significant advantages over other forms of imaging such as computed tomography (CT) or magnetic resonance imaging (MRI) scans in detecting disease in many patients. In the USA, an estimated 1 129 900 clinical PE...

  3. Clinical cardiac positron emission tomography: State of the art

    International Nuclear Information System (INIS)

    Cardiac positron emission tomography (PET) has evolved rapidly from a relatively esoteric research tool into clinical applications providing unique, quantitative information on myocardial perfusion, metabolism, and cell membrane function and having a potentially significant impact on cardiovascular medicine. Although there are many different positron radionuclides for imaging diverse myocardial behavior, three radionuclides have reached accepted clinical utility. Cardiac PET using nitrogen-13-ammonia, rubidium-82, and fluoro-18-deoxyglucose has proved accurate and definitive in multiple university and private-practice sites for diagnosing and assessing severity and location of coronary artery disease in symptomatic or asymptomatic patients, for identifying injured but viable myocardium potentially salvageable by revascularization, and for ruling out clinically significant coronary artery stenosis with a high specificity in patients who might otherwise undergo coronary arteriography to document the absence of significant disease. 89 references

  4. Kinetic modeling in pre-clinical positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kuntner, Claudia [AIT Austrian Institute of Technology GmbH, Seibersdorf (Austria). Biomedical Systems, Health and Environment Dept.

    2014-07-01

    Pre-clinical positron emission tomography (PET) has evolved in the last few years from pure visualization of radiotracer uptake and distribution towards quantification of the physiological parameters. For reliable and reproducible quantification the kinetic modeling methods used to obtain relevant parameters of radiotracer tissue interaction are important. Here we present different kinetic modeling techniques with a focus on compartmental models including plasma input models and reference tissue input models. The experimental challenges of deriving the plasma input function in rodents and the effect of anesthesia are discussed. Finally, in vivo application of kinetic modeling in various areas of pre-clinical research is presented and compared to human data.

  5. Methods and clinical applications of positron emission tomography in endocrinology

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) allows to detect in coincidence photons issued from annihilation between positrons and electrons nearby situated. Tomographic detection (plane by plane) and tomographic reconstruction will lead to the quantitation of radioactive distribution per voxel, in the organ of interest. Recent tomographs can acquire simultaneously several transaxial slices, with a high sensitivity and a spatial resolution of 3-5 mm. Commonly used positron emitters have a short half-life: 2, 10, 20 and 110 min for 150, 13N, 11C and 18F, respectively. The use of these isotopes requires on line production of radionuclides and synthesis of selected molecules. In endocrinology, PET allows among others to study noninvasively the receptor density of hormonodependent neoplasms such as breast, uterus, prostate tumors and prolactinomas. These last tumors represent a particular entity because of several combined characteristics: high turnover rate of amino acids, high density of dopaminergic receptors and response to bromocriptine (analogue of dopamine inhibiting the secretion of prolactine) in relation to the level of receptors. Because PET permits to evaluate the density of dopaminergic receptors and the metabolism of amino acids, theoretical response of the prolactinoma to bromocriptin can be predicted, the achieved therapeutic efficacy can be estimated and the long-term follow up of tumor growth can be assessed. This example illustrates the clinical value of PET in endocrinology

  6. Positron Emission Tomography (PET) and breast cancer in clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Lavayssiere, Robert [Centre d' Imagerie Paris-Nord, 1, avenue Charles Peguy, 95200 Sarcelles (France); Institut du Sein Henri Hartmann (ISHH), 1, rue des Dames Augustines, 92200 Neuilly sur Seine (France)], E-mail: cab.lav@wanadoo.fr; Cabee, Anne-Elizabeth [Centre d' Imagerie Paris-Nord, 1, avenue Charles Peguy, 95200 Sarcelles (France); Institut du Sein Henri Hartmann (ISHH), 1, rue des Dames Augustines, 92200 Neuilly sur Seine (France); Centre RMX, 80, avenue Felix Faure, 75105 Paris (France); Filmont, Jean-Emmanuel [Institut du Sein Henri Hartmann (ISHH), 1, rue des Dames Augustines, 92200 Neuilly sur Seine (France); American Hospital of Paris, Nuclear Medicine, 63, boulevard Victor Hugo - BP 109, 92202 Neuilly sur Seine Cedex (France)

    2009-01-15

    The landscape of oncologic practice has changed deeply during the past few years and there is now a need, through a multidisciplinary approach, for imaging to provide accurate evaluation of morphology and function and to guide treatment (Image Guided Therapy). Increasing emphasis has been put on Position Emission Tomography (PET) role in various cancers among clinicians and patients despite a general context of healthcare expenditure limitation. Positron Emission Tomography has currently a limited role in breast cancer, but also general radiologists and specialists should be aware of these indications, especially when staging aggressive cancers and looking for recurrence. Currently, the hybrid systems associating PET and Computed Tomography (CT) and in the same device [Rohren EM, Turkington TG, Coleman RE. Clinical applications of PET in oncology. Radiology 2004;231:305-32; Blodgett TM, Meltzer CM, Townsend DW. PET/CT: form and function. Radiology 2007;242:360-85; von Schulthess GK, Steinert HC, Hany TF. Integrated PET/CT: current applications and futures directions. Radiology 2006;238(2):405-22], or PET-CT, are more commonly used and the two techniques are adding their potentialities. Other techniques, MRI in particular, may also compete with PET in some instance and as far as ionizing radiations dose limitation is considered, some breast cancers becoming some form of a chronic disease. Breast cancer is a very complex, non-uniform, disease and molecular imaging at large may contribute to a better knowledge and to new drugs development. Ongoing research, Positron Emission Mammography (PEM) and new tracers, are likely to bring improvements in patient care [Kelloff GJ, Hoffman JM, Johnson B, et al. Progress and promise of FDG-PET Imaging for cancer patient management and oncologic drug development. Clin Cancer Res 2005;1(April (8)): 2005].

  7. Positron Emission Tomography (PET) and breast cancer in clinical practice

    International Nuclear Information System (INIS)

    The landscape of oncologic practice has changed deeply during the past few years and there is now a need, through a multidisciplinary approach, for imaging to provide accurate evaluation of morphology and function and to guide treatment (Image Guided Therapy). Increasing emphasis has been put on Position Emission Tomography (PET) role in various cancers among clinicians and patients despite a general context of healthcare expenditure limitation. Positron Emission Tomography has currently a limited role in breast cancer, but also general radiologists and specialists should be aware of these indications, especially when staging aggressive cancers and looking for recurrence. Currently, the hybrid systems associating PET and Computed Tomography (CT) and in the same device [Rohren EM, Turkington TG, Coleman RE. Clinical applications of PET in oncology. Radiology 2004;231:305-32; Blodgett TM, Meltzer CM, Townsend DW. PET/CT: form and function. Radiology 2007;242:360-85; von Schulthess GK, Steinert HC, Hany TF. Integrated PET/CT: current applications and futures directions. Radiology 2006;238(2):405-22], or PET-CT, are more commonly used and the two techniques are adding their potentialities. Other techniques, MRI in particular, may also compete with PET in some instance and as far as ionizing radiations dose limitation is considered, some breast cancers becoming some form of a chronic disease. Breast cancer is a very complex, non-uniform, disease and molecular imaging at large may contribute to a better knowledge and to new drugs development. Ongoing research, Positron Emission Mammography (PEM) and new tracers, are likely to bring improvements in patient care [Kelloff GJ, Hoffman JM, Johnson B, et al. Progress and promise of FDG-PET Imaging for cancer patient management and oncologic drug development. Clin Cancer Res 2005;1(April (8)): 2005

  8. Clinical application of positron emission tomography imaging in urologic tumors

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is an advanced noninvasive molecular imaging modality that is being investigated for use in the differentiation, diagnosis, and guiding therapy ora variety of cancer types. FDG PET has the unique clinical value in the differentiation, diagnosis, and monitoring therapy of prostate, such as bladder, renal, and testicle cancer. However, high false-positive and false-negative findings are observed in the detection of these tumors with FDG PET. 11C-Choline (CH) and 11C-acetate (AC) can overcome the pitfall of FDG, and appear to be more successful than FGD in imaging prostate cancer and bladder cancer. The short half-life of 11C prevents the widespread use of CH and AC and 18F-fluorocholine (FCH) and 18F-fluoroacetate (FAC) seem to be potential tracers. Potential clinical value of the new PET tracers, such as 3'-deoxy-3'-18F-fluorothymidine (FLT), 18F-fluorodihydrotestosterone (FDHT), and 9-(4-18F-3-hydroxymethylbutyl)-guanine(18F-FHBG) in the detection of urologic tumors, can deserve further study. (authors)

  9. Development of radioisotopically labeled compounds for clinical positron emission tomography

    International Nuclear Information System (INIS)

    It is its quantitative imaging capacity with high spatial resolution that makes positron emission tomography a unique tool for the development of quantitative tracer kinetic studies for the measurement of physiological processes in man. Research success in this area will depend on the ingenuity of biomedical scientists in prioritizing the development of tracers. Choices must be made based on the importance of different physiological measurements, the capacity to synthesize an appropriate radioisotopically labeled compound for this measurement and the ability to determine an adequate kinetic model for its interpretation. Examples are given of these steps in the development of PET tracers at the NIMH. 17 refs.; 1 table

  10. Positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a method for quantitative imaging of regional physiological and biochemical parameters. Positron emitting radioactive isotopes can be produced by a cyclotron, eg. the biologically important carbon (11C), oxygen (15O), and nitrogen (13N) elements. With the tomographic principles of the PET scanner the quantitative distribution of the administered isotopes can be determined and images can be provided as well as dynamic information on blood flow, metabolism and receptor function. In neurology PET has been used for investigations on numerous physiological processes in the brain: circulation, metabolism and receptor studies. In Parkinson's disease PET studies have been able to localize the pathology specifically, and in early stroke PET technique can outline focal areas with living but non-functioning cells, and this could make it possible to intervene in this early state. With positron emission tomography a quantitative evaluation of myocardial blood flow, glucose and fatty acid metabolism can be made as well as combined assessments of blood flow and metabolism. Combined studies of blood flow and metabolism can determine whether myocardial segments with abnormal motility consist of necrotic or viable tissue, thereby delineating effects of revascularisation. In the future it will probably be possible to characterize the myocardial receptor status in different cardiac diseases. The PET technique is used in oncology for clinical as well as more basic research on tumor perfusion and metabolism. Further, tumor uptake of positron labelled cytotoxic drugs might predict the clinical benefit of treatment. (au) (19 refs.)

  11. Positron emission tomography. Basic principles

    International Nuclear Information System (INIS)

    The basic principles of positron emission tomography (PET) technique are reviewed. lt allows to obtain functional images from gamma rays produced by annihilation of a positron, a positive beta particle. This paper analyzes positron emitters production in a cyclotron, its general mechanisms, and the various detection systems. The most important clinical applications are also mentioned, related to oncological uses of fluor-l8-deoxyglucose

  12. Positron emission tomography-computed tomography has a clinical impact for patients with cervical cancer

    DEFF Research Database (Denmark)

    Sandvik, Rikke Mulvad; Jensen, Pernille Tine; Hendel, Helle W;

    2011-01-01

    Many studies have found that positron emission tomography-computed tomography (PET-CT) has a high sensitivity and specificity in the identification of metastasis in cervical cancer. Herlev Hospital, Denmark, has been performing PET-CTs in stage I-IV cervical cancer since 1 May 2006. The present...... study investigates the positive (PPV) and negative predictive value (NPV) of PET-CT in stage I disease and the clinical impact of the scan results in all disease stages....

  13. In vivo dopamine receptor assessment for clinical studies using positron emission tomography

    International Nuclear Information System (INIS)

    A discussion is presented of techniques to determine cerebral DA-receptor function in vivo and possible (future) applications of such techniques in clinical studies. A brief summary is given on existing approaches that are of particular clinical interest. The emphasis is laid on the in vivo receptor binding techniques, which have become of clinical interest with the advent of positron emission tomography. Both possibilities and limitations of the present methods to assess DA receptors and possible relationships to pathological or behavioral manifestations are described. (author)

  14. Clinical application of positron emission tomography for diagnosis of dementia

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Kazunari [Hyogo Brain and Heart Center, Himeji (Japan)

    2002-12-01

    Clinical applications of PET studies for dementia are reviewed in this paper. At the mild and moderate stages of Alzheimer's disease (AD), glucose metabolism is reduced not only in the parietotemporal region but also in the posterior cingulate and precuneus. At the advanced stage of AD, there is also a metabolic reduction in the frontal region. In AD patients, glucose metabolism is relatively preserved in the pons, sensorimotor cortices, primary visual cortices, basal ganglia, thalamus and cerebellum. In patients with dementia with Lewy bodies, glucose metabolism in the primary visual cortices is reduced, and this reduction appears to be associated with the reduction pattern in AD patients. In patients with frontotemporal dementia, reduced metabolism in the frontotemporal region is the main feature of this disease, but reduced metabolism in the basal ganglia, and/or parietal metabolic reduction can be associated with the frontotemporal reduction. When corticobasal degeneration is associated with dementia, the reduction pattern of dementia is similar to the reduction pattern in AD and the hallmarks of diagnosing corticobasal degeneration associated with dementia are a reduced metabolism in the primary sensorimotor region and/or basal ganglia and an asymmetric reduction in the two hemispheres. FDG-PET is a very useful tool for the diagnosis of early AD and for the differential diagnosis of dementia. I also describe clinical applications of PET for the diagnosis of dementia in Japan. (author)

  15. Clinical application of positron emission tomography for diagnosis of dementia

    International Nuclear Information System (INIS)

    Clinical applications of PET studies for dementia are reviewed in this paper. At the mild and moderate stages of Alzheimer's disease (AD), glucose metabolism is reduced not only in the parietotemporal region but also in the posterior cingulate and precuneus. At the advanced stage of AD, there is also a metabolic reduction in the frontal region. In AD patients, glucose metabolism is relatively preserved in the pons, sensorimotor cortices, primary visual cortices, basal ganglia, thalamus and cerebellum. In patients with dementia with Lewy bodies, glucose metabolism in the primary visual cortices is reduced, and this reduction appears to be associated with the reduction pattern in AD patients. In patients with frontotemporal dementia, reduced metabolism in the frontotemporal region is the main feature of this disease, but reduced metabolism in the basal ganglia, and/or parietal metabolic reduction can be associated with the frontotemporal reduction. When corticobasal degeneration is associated with dementia, the reduction pattern of dementia is similar to the reduction pattern in AD and the hallmarks of diagnosing corticobasal degeneration associated with dementia are a reduced metabolism in the primary sensorimotor region and/or basal ganglia and an asymmetric reduction in the two hemispheres. FDG-PET is a very useful tool for the diagnosis of early AD and for the differential diagnosis of dementia. I also describe clinical applications of PET for the diagnosis of dementia in Japan. (author)

  16. Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs

  17. Positron emission tomography.

    Science.gov (United States)

    Hoffman, E J; Phelps, M E

    1979-01-01

    Conventional nuclear imaging techniques utilizing lead collimation rely on radioactive tracers with little role in human physiology. The principles of imaging based on coincidence detection of the annihilation radiation produced in positron decay indicate that this mode of detection is uniquely suited for use in emission computed tomography. The only gamma-ray-emitting isotopes of carbon, nitrogen, and oxygen are positron emitters, which yield energies too high for conventional imaging techniques. Thus development of positron emitters in nuclear medicine imaging would make possible the use of a new class of physiologically active, positron-emitting radiopharmaceuticals. The application of these principles is described in the use of a physiologically active compound labeled with a positron emitter and positron-emission computed tomography to measure the local cerebral metabolic rate in humans. PMID:440173

  18. Clinical impact of 18F-fluorodeoxyglucose positron emission tomography in the diagnosis of neurological diseases

    International Nuclear Information System (INIS)

    In this review it will be discussed in which neurological disorders positron emission tomography can yield important diagnostic information. Because positron emission tomography is an expensive method indications have to be cleary defined. One important question concerns the differentiation of tumor recurrence and scar due to radiation therapy or an operation. The grading of brain tumors is another application. In HIV patients fluorodeoxyglucose positron emission tomography can separate lymphoma and toxoplasmosis. In the evaluation of dementia positron emission tomography can help to clarify the differential diagnosis. Another important area is the presurgical evaluation of epilepsy patients and patients with cerebrovascular disease in whom a surgical revascularization procedure is planned. In extrapyramidal disorders, positron emission tomography can often help to establish the final diagnosis. (author)

  19. Clinical correlates of decreased anteroposterior metabolic gradients in positron emission tomography (PET) of schizophrenic patients

    International Nuclear Information System (INIS)

    The finding in schizophrenic patients of a reversal of the normal frontal to posterior pattern of brain metabolic activity with positron emission tomography (PET) is of interest, but its relevance to psychopathology is unknown. Using PET, the authors studied 21 patients with chronic schizophrenia and 21 age- and sex-matched control subjects. Although eight of the 21 patients and only one of the control subjects showed a relatively lower anteroposterior metabolic gradient, no clinical correlates of this finding were noted. In addition, cerebral atrophy, as determined by CAT scan, was not associated with this aberrant metabolic pattern

  20. Clinical correlates of decreased anteroposterior metabolic gradients in positron emission tomography (PET) of schizophrenic patients

    Energy Technology Data Exchange (ETDEWEB)

    DeLisi, L.E.; Buchsbaum, M.S.; Holcomb, H.H.; Dowling-Zimmerman, S.; Pickar, D.; Boronow, J.; Morihisa, J.M.; van Kammen, D.P.; Carpenter, W.; Kessler, R.

    1985-01-01

    The finding in schizophrenic patients of a reversal of the normal frontal to posterior pattern of brain metabolic activity with positron emission tomography (PET) is of interest, but its relevance to psychopathology is unknown. Using PET, the authors studied 21 patients with chronic schizophrenia and 21 age- and sex-matched control subjects. Although eight of the 21 patients and only one of the control subjects showed a relatively lower anteroposterior metabolic gradient, no clinical correlates of this finding were noted. In addition, cerebral atrophy, as determined by CAT scan, was not associated with this aberrant metabolic pattern.

  1. Economic analysis of clinical positron emission tomography of the heart with rubidium-82

    International Nuclear Information System (INIS)

    This report describes a cost analysis for clinical positron emission tomography (PET) of the heart using generator produced rubidium-82 (82Rb). Considered sequentially are the clinical problem, current noninvasive radionuclide methods, positron emission tomograph, and the cost of PET per study. Also analyzed are the costs of PET versus thallium imaging in the management of chest pain, for screening asymptomatic men at high risk for coronary artery disease and for evaluating myocardial viability after myocardial infarction or thrombolytic therapy. Noninvasive assessment of coronary artery stenosis and myocardial ischemia/viability in symptomatic or asymptomatic subjects remains a major medical problem because the sensitivity and specificity of thallium imaging are only 70-85% and 50-70%, respectively, in recent studies. Cardiac positron imaging has an accuracy for noninvasive diagnosis of coronary artery disease in symptomatic or asymptomatic patients with a sensitivity and specificity of 95-98%. It can also be used for assessing physiologic stenosis severity, for imaging myocardial infarction and viability, for assessing effects of interventions such as thrombolysis, percutaneous transluminal coronary angioplasty (PTCA) or bypass surgery on myocardial perfusion, metabolism or coronary flow reserve, for assessing collateral function noninvasively in man, and for diagnosing cardiomyopathy not due to coronary artery disease. Although the cost for cardiac PET with 82Rb may be modestly higher than for 201Tl, the greater diagnostic yield of PET results in comparable or lower overall medical management costs than no diagnostic tests/interventions and lower overall costs compared to thallium imaging for evaluating patients with chest pain, asymptomatic high risk males, and patients after acute myocardial infarction/thrombolysis for myocardial viability

  2. Positron-emission tomography

    International Nuclear Information System (INIS)

    Positron-emission tomography (PET) combines early biochemical assessment of pathology achieved by nuclear medicine with the precise localization achieved by computerized image reconstruction. In this technique a chemical compound with the desired biological activity is labeled with a radioactive isotope that decays by emitting a positron, or positive electron. With suitable interpretation PET images can provide a noninvasive, regional assessment of many biochemical processes that are essential to the functioning of the organ that is being visualized

  3. Clinical use of amyloid-positron emission tomography neuroimaging: Practical and bioethical considerations.

    Science.gov (United States)

    Witte, Michael M; Foster, Norman L; Fleisher, Adam S; Williams, Monique M; Quaid, Kimberly; Wasserman, Michael; Hunt, Gail; Roberts, J Scott; Rabinovici, Gil D; Levenson, James L; Hake, Ann Marie; Hunter, Craig A; Van Campen, Luann E; Pontecorvo, Michael J; Hochstetler, Helen M; Tabas, Linda B; Trzepacz, Paula T

    2015-09-01

    Until recently, estimation of β-amyloid plaque density as a key element for identifying Alzheimer's disease (AD) pathology as the cause of cognitive impairment was only possible at autopsy. Now with amyloid-positron emission tomography (amyloid-PET) neuroimaging, this AD hallmark can be detected antemortem. Practitioners and patients need to better understand potential diagnostic benefits and limitations of amyloid-PET and the complex practical, ethical, and social implications surrounding this new technology. To complement the practical considerations, Eli Lilly and Company sponsored a Bioethics Advisory Board to discuss ethical issues that might arise from clinical use of amyloid-PET neuroimaging with patients being evaluated for causes of cognitive decline. To best address the multifaceted issues associated with amyloid-PET neuroimaging, we recommend this technology be used only by experienced imaging and treating physicians in appropriately selected patients and only in the context of a comprehensive clinical evaluation with adequate explanations before and after the scan. PMID:27239516

  4. Re-Evaluation of Clinical Dementia Diagnoses with Pittsburgh Compound B Positron Emission Tomography

    Directory of Open Access Journals (Sweden)

    M. Degerman Gunnarsson

    2013-12-01

    Full Text Available Objectives: There is an overlap regarding Pittsburgh compound B (PIB retention in patients clinically diagnosed as Alzheimer's disease (AD and non-AD dementia. The aim of the present study was to investigate whether there are any differences between PIB-positive and PIB-negative patients in a mixed cohort of patients with neurodegenerative dementia of mild severity regarding neuropsychological test performance and regional cerebral glucose metabolism measured with [18F]fluoro-2-deoxy-D-glucose (FDG positron emission tomography (PET. Methods: Eighteen patients clinically diagnosed as probable AD or frontotemporal dementia were examined with PIB PET, FDG PET and neuropsychological tests and followed for 5-9 years in a clinical setting. Results: The PIB-positive patients (7 out of 18 had slower psychomotor speed and more impaired visual episodic memory than the PIB-negative patients; otherwise performance did not differ between the groups. The initial clinical diagnoses were changed in one third of the patients (6 out of 18 during follow-up. Conclusions: The subtle differences in neuropsychological performance, the overlap of hypometabolic patterns and clinical features between AD and non-AD dementia highlight the need for amyloid biomarkers and a readiness to re-evaluate the initial diagnosis.

  5. Positron emission tomography

    International Nuclear Information System (INIS)

    The aim of this project is to provide a simple summary of new trends in positron emission tomography and its basic physical principles. It provides thereby compendious introduction of the trends of the present development in diagnostics using PET systems. A review of available literature was performed. (author)

  6. Integration of Quantitative Positron Emission Tomography Absolute Myocardial Blood Flow Measurements in the Clinical Management of Coronary Artery Disease.

    Science.gov (United States)

    Gewirtz, Henry; Dilsizian, Vasken

    2016-05-31

    In the >40 years since planar myocardial imaging with(43)K-potassium was introduced into clinical research and management of patients with coronary artery disease (CAD), diagnosis and treatment have undergone profound scientific and technological changes. One such innovation is the current state-of-the-art hardware and software for positron emission tomography myocardial perfusion imaging, which has advanced it from a strictly research-oriented modality to a clinically valuable tool. This review traces the evolving role of quantitative positron emission tomography measurements of myocardial blood flow in the evaluation and management of patients with CAD. It presents methodology, currently or soon to be available, that offers a paradigm shift in CAD management. Heretofore, radionuclide myocardial perfusion imaging has been primarily qualitative or at best semiquantitative in nature, assessing regional perfusion in relative terms. Thus, unlike so many facets of modern cardiovascular practice and CAD management, which depend, for example, on absolute values of key parameters such as arterial and left ventricular pressures, serum lipoprotein, and other biomarker levels, the absolute levels of rest and maximal myocardial blood flow have yet to be incorporated into routine clinical practice even in most positron emission tomography centers where the potential to do so exists. Accordingly, this review focuses on potential value added for improving clinical CAD practice by measuring the absolute level of rest and maximal myocardial blood flow. Physiological principles and imaging fundamentals necessary to understand how positron emission tomography makes robust, quantitative measurements of myocardial blood flow possible are highlighted. PMID:27245647

  7. Positron emission tomography

    CERN Document Server

    Paans, A M J

    2006-01-01

    Positron Emission Tomography (PET) is a method for measuring biochemical and physiological processes in vivo in a quantitative way by using radiopharmaceuticals labelled with positron emitting radionuclides such as 11C, 13N, 15O and 18F and by measuring the annihilation radiation using a coincidence technique. This includes also the measurement of the pharmacokinetics of labelled drugs and the measurement of the effects of drugs on metabolism. Also deviations of normal metabolism can be measured and insight into biological processes responsible for diseases can be obtained. At present the combined PET/CT scanner is the most frequently used scanner for whole-body scanning in the field of oncology.

  8. Tomography by positrons emission

    International Nuclear Information System (INIS)

    The tomography by positrons emission is a technology that allows to measure the concentration of positrons emission in a tri dimensional body through external measurements. Among the isotope emissions have carbon isotopes are (11C), of the oxygen (15O), of the nitrogen (13N) that are three the element that constitute the base of the organic chemistry. Theses have on of the PET's most important advantages, since many biological interesting organic molecules can be tracer with these isotopes for the metabolism studies 'in vivo' through PET, without using organic tracers that modify the metabolism. The mentioned isotopes, also possess the characteristic of having short lifetime, that constitute on of PET's advantages from the dosimetric point of view. Among 11C, 15O, and 13N, other isotopes that can be obtained of a generator as the 68Ga and 82Rb

  9. A clinical evaluation of the quantitative accuracy of simultaneous emission/transmission scanning in whole-body positron emission tomography

    International Nuclear Information System (INIS)

    We present a clinical evaluation of the quantitative bias which is introduced during simultaneous emission/transmission (SET) acquisition for the application of whole-body positron emission tomography (PET) with fluorine-18 2-fluoro-2-deoxy-d-glucose. The quantitative accuracy of the SET technique was assessed by means of a clinical study involving 28 patients and a realistic phantom experiment. In the clinical study, SET overestimated the activity concentration in the tumours by a factor of approximately 1.10, but in the phantom study, where the tumours were smaller, the bias was found to increase to a value of 1.39. The bias in the soft tissue regions of the patient studies varied between 1.03 and 1.36, and close agreement was observed with the corresponding phantom results. The extent of the bias increased as the local activity concentration decreased and we attribute the effect to scattered photons from the transmission source which are detected in the emission window during SET. (orig.)

  10. Positron emission tomography-computed tomography has a clinical impact for patients with cervical cancer

    DEFF Research Database (Denmark)

    Sandvik, Rikke Mulvad; Jensen, Pernille Tine; Hendel, Helle Westergren;

    2011-01-01

    Many studies have found that positron emission tomography-computed tomography (PET-CT) has a high sensitivity and specificity in the identification of metastasis in cervical cancer. Herlev Hospital, Denmark, has been performing PET-CTs in stage I-IV cervical cancer since 1 May 2006. The present...

  11. Professional practice assessment. Pertinence of positron emission tomography clinical indications in oncology

    International Nuclear Information System (INIS)

    Introduction As part of the health care quality and safety policy in France, Professional Practice Assessment (P.P.A.) are mandatory in the health services 'certification' process. We present our study regarding the pertinence of Positron Emission Tomography (PET) indications in oncology. Materials and methods A multidisciplinary task group used the Quick Audit method with two rounds of 100 request forms each. The assessment list of criteria comprised four items of decreasing relevance grading the PET scans clinical indications, which were derived from the three French published guidelines (S.O.R. [F.N.C.L.C.C]., 'Guide du bon usage des examens d'imagerie medicale' [S.F.R.-S.F.M.N.], 'Guide pour la redaction de protocoles pour la TEP au F.D.G. en cancerologie' [S.F.M.N.]) and five additional items: clinical information, patient's body weight, previous treatments dates, diabetes, claustrophobia. Results The first round showed that 68% of the requested scans corresponded to the two most relevant groups of indications (S.O.R. Standards and Options). The request forms were correctly filled in regarding the clinical information, but this was not the case for the other items we tested. Several actions were conducted: dedicated PET request form, availability of the S.O.R. on the hospital intranet, boost of the referring physicians awareness during the multidisciplinary oncology meetings (Reunions de Concertation Pluridisciplinaires RCP). The second round showed a better pertinence of the PET scans indications (75% versus 68%); the patient's body weight was more frequently mentioned on the request form. Discussion This study is an example of P.P.A. in our discipline. It led to an improvement of the oncologic PET scans clinical indications in our hospital. This work is pursued in everyday discussion with the referring clinicians, especially during the RCP. (authors)

  12. Clinical Utility of Positron Emission Tomography Magnetic Resonance Imaging (PET-MRI) in Gastrointestinal Cancers.

    Science.gov (United States)

    Matthews, Robert; Choi, Minsig

    2016-01-01

    Anatomic imaging utilizing both CT (computed tomography) and MRI (magnetic resonance imaging) limits the assessment of cancer metastases in lymph nodes and distant organs while functional imaging like PET (positron emission tomography) scan has its limitation in spatial resolution capacity. Hybrid imaging utilizing PET-CT and PET-MRI are novel imaging modalities that are changing the current landscape in cancer diagnosis, staging, and treatment response. MRI has shown to have higher sensitivity in soft tissue, head and neck pathology, and pelvic disease, as well as, detecting small metastases in the liver and bone compared to CT. Combining MRI with PET allows for detection of metastases that may have been missed with current imaging modalities. In this review, we will examine the clinical utility of FDG PET-MRI in the diagnosis and staging of gastrointestinal cancers with focus on esophageal, stomach, colorectal, and pancreatic cancers. We will also explore its role in treatment response and future directions associated with it. PMID:27618106

  13. Positron Emission Tomography (PET) and its application in clinical diagnosis and functional brain organization studies

    International Nuclear Information System (INIS)

    Recent advances in positron emission tomography (PET) and other brain-imaging techniques have made it possible to visualize the working brain while the human subject is thinking, speaking or planning an action. PET provides researches with an opportunity to infer the neuroanatomy of a given function. Subjects either inhale or are injected with a radioactive material that binds to a physiologically active compound in the body. This serves as a tracer of blood flow and metabolic processes that reflect the activation of a given structure by emitting gamma rays which may be detected through a tomograph. PET research has produced findings that extend our knowledge on several important issues such as cerebral representation of language, perception, attention or memory. It has also proven to be an important source of information for clinical diagnosis of various neurological and psychiatric diseases. The present article provides a short review of main achievements in those fields. However, functional brain imaging is not exempt from methodological and theoretical difficulties. The main limitations of the method have been outlined. (author)

  14. Clinical Imaging Characteristics of the Positron Emission Mammography Camera: PEM Flex Solo II

    OpenAIRE

    MacDonald, Lawrence; Edwards, John; Lewellen, Thomas; Haseley, David; Rogers, James; Kinahan, Paul

    2009-01-01

    We evaluated a commercial positron emission mammography (PEM) camera, the PEM Flex Solo II. This system comprises two 6 × 16.4 cm detectors that scan together covering up to a 24 × 16.4 cm field of view (FOV). There are no specific standards for testing this detector configuration. We performed several tests important to breast imaging, and we propose tests that should be included in standardized testing of PEM systems.

  15. Pre-clinical Positron Emission Tomography Reconstruction Algorithm Effect on Cu-64 ATSM Lesion Hypoxia

    Directory of Open Access Journals (Sweden)

    Bal Sanghera

    2016-02-01

    Full Text Available Objective: Application of distinct positron emission tomography (PET scan reconstruction algorithms can lead to statistically significant differences in measuring lesion functional properties. We looked at the influence of two-dimensional filtered back projection (2D FBP, two-dimensional ordered subset expectation maximization (2D OSEM, three-dimensional ordered subset expectation maximization (3D OSEM without 3D maximum a posteriori and with (3D OSEM MAP on lesion hypoxia tracer uptake using a pre-clinical PET scanner. Methods: Reconstructed images of a rodent tumor model bearing P22 carcinosarcoma injected with hypoxia tracer Copper- 64-Diacetyl-bis (N4-methylthiosemicarbazone (i.e. Cu-64 ATSM were analyzed at 10 minute intervals till 60 minute post injection. Lesion maximum standardized uptake values (SUVmax and SUVmax/background SUVmean (T/B were recorded and investigated after application of multiple algorithm and reconstruction parameters to assess their influence on Cu-64 ATSM measurements and associated trends over time. Results: SUVmax exhibited convergence for OSEM reconstructions while ANOVA results showed a significant difference in SUVmax or T/B between 2D FBP, 2D OSEM, 3D OSEM and 3D OSEM MAP reconstructions across all time frames. SUVmax and T/B were greatest in magnitude for 2D OSEM followed by 3D OSEM MAP, 3D OSEM and then 2D FBP at all time frames respectively. Similarly SUVmax and T/B standard deviations (SD were lowest for 2D OSEM in comparison with other algorithms. Conclusion: Significantly higher magnitude lesion SUVmax and T/B combined with lower SD were observed using 2D OSEM reconstruction in comparison with 2D FBP, 3D OSEM and 3D OSEM MAP algorithms at all time frames. Results are consistent with other published studies however more specimens are required for full validation.

  16. Positron emission mammography imaging

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W.

    2003-10-02

    This paper examines current trends in Positron Emission Mammography (PEM) instrumentation and the performance tradeoffs inherent in them. The most common geometry is a pair of parallel planes of detector modules. They subtend a larger solid angle around the breast than conventional PET cameras, and so have both higher efficiency and lower cost. Extensions to this geometry include encircling the breast, measuring the depth of interaction (DOI), and dual-modality imaging (PEM and x-ray mammography, as well as PEM and x-ray guided biopsy). The ultimate utility of PEM may not be decided by instrument performance, but by biological and medical factors, such as the patient to patient variation in radiotracer uptake or the as yet undetermined role of PEM in breast cancer diagnosis and treatment.

  17. Positron emission tomography basic sciences

    CERN Document Server

    Townsend, D W; Valk, P E; Maisey, M N

    2003-01-01

    Essential for students, science and medical graduates who want to understand the basic science of Positron Emission Tomography (PET), this book describes the physics, chemistry, technology and overview of the clinical uses behind the science of PET and the imaging techniques it uses. In recent years, PET has moved from high-end research imaging tool used by the highly specialized to an essential component of clinical evaluation in the clinic, especially in cancer management. Previously being the realm of scientists, this book explains PET instrumentation, radiochemistry, PET data acquisition and image formation, integration of structural and functional images, radiation dosimetry and protection, and applications in dedicated areas such as drug development, oncology, and gene expression imaging. The technologist, the science, engineering or chemistry graduate seeking further detailed information about PET, or the medical advanced trainee wishing to gain insight into the basic science of PET will find this book...

  18. Clinical impact of Positron Emission Tomography (PET) on oncological patients and their potentially application context

    International Nuclear Information System (INIS)

    (PET) Positron Emission Tomography is a technique of nuclear medicine that has ability of detecting cancer through mechanisms based on molecular alterations of neoplastic processes. This review describes the PET Oncology applications and discusses the potential application of this technology in the sanitary and national academic framework . The most widely used in Oncology plotter is an analogue of laglucosa labelled with fluo: 18F-2-fluoro-2-Deoxy-D-glucose (FDG). In this way, the PET detects tumour retention of FDG, due to the highest glycolytic of cancer cells. In addition, the PET allow the study of the entire body at the same exploratory and some teams are coupled to systems of axial tomography (PET-CT). By ET-FDG, it is possible to diagnose, staging and restaged the majority of cancers, with diagnostic accuracy close to 90 per cent higher than the values provided by the conventional imaging techniques such. It is also possible to know early response to cancer treatments and obtain relevant medical prognosis information. (author)

  19. Fundamentals of positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography is a modern radionuclide method of measuring physiological quantities or metabolic parameters in vivo. The methods is based on: (1) Radioactive labelling with positron emitters; (2) the coincidence technique for the measurement of the annihilation radiation following positron decay; (3) analysis of the data measured using biological models. The basic aspects and problems of the method are discussed. The main fields of future research are the synthesis of new labelled compounds and the development of mathematical models of the biological processes to be investigated. (orig.)

  20. [Fundamentals of positron emission tomography].

    Science.gov (United States)

    Ostertag, H

    1989-07-01

    Positron emission tomography is a modern radionuclide method of measuring physiological quantities or metabolic parameters in vivo. The method is based on: (1) radioactive labelling with positron emitters; (2) the coincidence technique for the measurement of the annihilation radiation following positron decay; (3) analysis of the data measured using biological models. The basic aspects and problems of the method are discussed. The main fields of future research are the synthesis of new labelled compounds and the development of mathematical models of the biological processes to be investigated. PMID:2667029

  1. NMF on positron emission tomography

    DEFF Research Database (Denmark)

    Bödvarsson, Bjarni; Hansen, Lars Kai; Svarer, Claus;

    2007-01-01

    In positron emission tomography, kinetic modelling of brain tracer uptake, metabolism or binding requires knowledge of the cerebral input function. Traditionally, this is achieved with arterial blood sampling in the arm or as shown in (Liptrot, M, et al., 2004) by non-invasive K-means clustering....... We propose another method to estimate time-activity curves (TAC) extracted directly from dynamic positron emission tomography (PET) scans by non-negative matrix factorization (NMF). Since the scaling of the basis curves is lost in the NMF the estimated TAC is scaled by a vector alpha which is...

  2. Systematic screening of imaging biomarkers for the Islets of Langerhans, among clinically available positron emission tomography tracers

    International Nuclear Information System (INIS)

    Introduction: Functional imaging could be utilized for visualizing pancreatic islets of Langerhans. Therefore, we present a stepwise algorithm for screening of clinically available positron emission tomography (PET) tracers for their use in imaging of the neuroendocrine pancreas in the context of diabetes. Methods: A stepwise procedure was developed for screening potential islet imaging agents. Suitable PET-tracer candidates were identified by their molecular mechanism of targeting. Clinical abdominal examinations were retrospectively analyzed for pancreatic uptake and retention. The target protein localization in the pancreas was assessed in silico by –omics approaches and the in vitro by binding assays to human pancreatic tissue. Results: Six putative candidates were identified and screened by using the stepwise procedure. Among the tested PET tracers, only [11C]5-Hydroxy-tryptophan passed all steps. The remaining identified candidates were falsified as candidates and discarded following in silico and in vitro screening. Conclusions: Of the six clinically available PET tracers identified, [11C]5-HTP was found to be a promising candidate for beta cell imaging, based on intensity of in vivo pancreatic uptake in humans, and islet specificity as assessed on human pancreatic cell preparations. The flow scheme described herein constitutes a methodology for evaluating putative islet imaging biomarkers among clinically available PET tracers

  3. Methods and clinical applications of positron emission tomography in endocrinology. Methodologie et applications cliniques en endocrinologie de la tomographie a emission de positons

    Energy Technology Data Exchange (ETDEWEB)

    Landsheere, C. de; Lamotte, D. (Liege Univ. (BE))

    1990-01-01

    Positron emission tomography (PET) allows to detect in coincidence photons issued from annihilation between positrons and electrons nearby situated. Tomographic detection (plane by plane) and tomographic reconstruction will lead to the quantitation of radioactive distribution per voxel, in the organ of interest. Recent tomographs can acquire simultaneously several transaxial slices, with a high sensitivity and a spatial resolution of 3-5 mm. Commonly used positron emitters have a short half-life: 2, 10, 20 and 110 min for {sup 15}0, {sup 13}N, {sup 11}C and {sup 18}F, respectively. The use of these isotopes requires on line production of radionuclides and synthesis of selected molecules. In endocrinology, PET allows among others to study noninvasively the receptor density of hormonodependent neoplasms such as breast, uterus, prostate tumors and prolactinomas. These last tumors represent a particular entity because of several combined characteristics: high turnover rate of amino acids, high density of dopaminergic receptors and response to bromocriptine (analogue of dopamine inhibiting the secretion of prolactine) in relation to the level of receptors. Because PET permits to evaluate the density of dopaminergic receptors and the metabolism of amino acids, theoretical response of the prolactinoma to bromocriptin can be predicted, the achieved therapeutic efficacy can be estimated and the long-term follow up of tumor growth can be assessed. This example illustrates the clinical value of PET in endocrinology.

  4. Instrumentation in positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a three-dimensional medical imaging technique that noninvasively measures the concentration of radiopharmaceuticals in the body that are labeled with positron emitters. With the proper compounds, PET can be used to measure metabolism, blood flow, or other physiological values in vivo. The technique is based on the physics of positron annihilation and detection and the mathematical formulations developed for x-ray computed tomography. Modern PET systems can provide three-dimensional images of the brain, the heart, and other internal organs with resolutions on the order of 4 to 6 mm. With the selectivity provided by a choice of injected compounds, PET has the power to provide unique diagnostic information that is not available with any other imaging modality. This is the first five reports on the nature and uses of PET that have been prepared for the American Medical Association's Council on Scientific Affairs by an authoritative panel

  5. Can positron emission tomography be more than a diagnostic tool? A survey on clinical practice among radiation oncologists in India

    Directory of Open Access Journals (Sweden)

    HMT Thomas

    2014-01-01

    Full Text Available Aim: The purpose of the survey was to understand the role of positron emission tomography (PET in clinical radiotherapy practice among the radiation oncologists′ in India. Settings and Design: An online questionnaire was developed to survey the oncologists on their use of PET, viewing protocols, contouring techniques practiced, the barriers on the use of PET and the need for training in use of PET in radiotherapy. The questionnaire was sent to about 500 oncologists and 76 completed responses were received. Results: The survey shows that radiation oncologists use PET largely to assess treatment response and staging but limitedly use it for radiotherapy treatment planning. Only manual contouring and fixed threshold based delineation techniques (e.g. 40% maximum standard uptake value [SUV max ] or SUV 2.5 are used. Cost is the major barrier in the wider use of PET, followed by limited availability of FDG radionuclide tracer. Limited or no training was available for the use of PET. Conclusions: Our survey revealed the vast difference between literature suggestions and actual clinical practice on the use of PET in radiotherapy. Additional training and standardization of protocols for use of PET in radiotherapy is essential for fully utilizing the capability of PET.

  6. Imaging β-amyloid using [{sup 18}F]flutemetamol positron emission tomography: from dosimetry to clinical diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Heurling, Kerstin; Lubberink, Mark [Uppsala University, Section of Nuclear Medicine and PET, Department of Surgical Sciences, Uppsala (Sweden); Leuzy, Antoine [Karolinska Institutet, Department NVS, Centre for Alzheimer Research, Division of Translational Alzheimer Neurobiology, Huddinge (Sweden); Zimmer, Eduardo R. [Pontifical Catholic University of Rio Grande do Sul (PUCRS), Brain Institute of Rio Grande do Sul (BraIns), Porto Alegre (Brazil); Federal University of Rio Grande do Sul (UFRGS), Department of Biochemistry, Porto Alegre (Brazil); Nordberg, Agneta [Karolinska Institutet, Department NVS, Centre for Alzheimer Research, Division of Translational Alzheimer Neurobiology, Huddinge (Sweden); Karolinska University Hospital Huddinge, Department of Geriatric Medicine, Stockholm (Sweden)

    2016-02-15

    In Alzheimer's disease (AD), the deposition of β-amyloid (Aβ) is hypothesized to result in a series of secondary neurodegenerative processes, leading ultimately to synaptic dysfunction and neuronal loss. Since the advent of the first Aβ-specific positron emission tomography (PET) ligand, {sup 11}C-Pittsburgh compound B ([{sup 11}C]PIB), several {sup 18}F ligands have been developed that circumvent the limitations of [{sup 11}C]PIB tied to its short half-life. To date, three such compounds have been approved for clinical use by the US and European regulatory bodies, including [{sup 18}F]AV-45 ([{sup 18}F]florbetapir; Amyvid trademark), [{sup 18}F]-BAY94-9172 ([{sup 18}F]florbetaben; Neuraceq trademark) and [{sup 18}F]3'-F-PIB ([{sup 18}F]flutemetamol; Vizamyl trademark). The present review aims to summarize and discuss the currently available knowledge on [{sup 18}F]flutemetamol PET. As the {sup 18}F analogue of [{sup 11}C]PIB, [{sup 18}F]flutemetamol may be of use in the differentiation of AD from related neurodegenerative disorders and may help with subject selection and measurement of target engagement in the context of clinical trials testing anti-amyloid therapeutics. We will also discuss its potential use in non-AD amyloidopathies. (orig.)

  7. Clinical applications of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in carcinoma of unknown primary

    Institute of Scientific and Technical Information of China (English)

    HU Man; YU Jin-ming; ZHAO Wei; ZHANG Pin-liang; JU Gui-fang; FU Zheng; ZHANG Guo-li; KONG Li; YANG Yan-qin; MA Yi-dong

    2011-01-01

    Background Carcinoma of unknown primary (CUP) encompasses a heterogeneous group of tumors with varying clinical features. The management of patients of CUP remains a clinical challenge. The purpose of this study was to evaluate the clinical applications of integrated 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) information in patients with CUP,including detecting the occult primary tumor and effecting on disease therapy.Methods One hundred and forty-nine patients with histologically-proven metastases of CUP were included. For all patients,the conventional diagnostic work-up was unsuccessful in localizing the primary site. Whole-body PET/CT images were obtained approximately 60 minutes after intravenous injection of 350-425 MBq of 18F-FDG.Results In 24.8% of patients,FDG PET/CT detected primary tumors that were not apparent after conventional workup.In this group of patients,the overall sensitivity,specificity,and accuracy rates of FDG PET/CT in detecting unknown primary tumors were 86.0%,87.7%,and 87.2%,respectively. FDG PET/CT imaging also led to the detection of previously unrecognized metastases in 29.5% of patients. Forty-seven (31.5%,47 of 149) patients underwent a change in therapeutic management.Conclusions FDG PET/CT is a valuable tool in patients with CUP,because it assisted in detecting unknown primary tumors and previously unrecognized distant metastases,and optimized the mangement of these patients.

  8. Positron Emission Tomography: Its 65 years

    Science.gov (United States)

    Del Guerra, A.; Belcari, N.; Bisogni, M.

    2016-04-01

    Positron Emission Tomography (PET) is a well-established imaging technique for in vivo molecular imaging. In this review after a brief history of PET there are presented its physical principles and the technology that has been developed for bringing PET from a bench experiment to a clinical indispensable instrument. The limitations and performance of the PET tomographs are discussed, both as for the hardware and software aspects. The status of art of clinical, pre-clinical and hybrid scanners (, PET/CT and PET/MR) is reported. Finally the actual trend and the recent and future technological developments are fully illustrated.

  9. State of the art and prospects of clinical applications of positron emission tomography and examination with 18F-fluorodeoxyglucose

    International Nuclear Information System (INIS)

    Positron emission tomography attains a 95% precision in oncological diagnosis. The use of fluorine 18-labelled fluorodeoxyglucose during in vivo tumor imaging is based on the finding that neoplasm cells exhibit elevated glycolytic activity. The share of oncological examinations is 70% to 80%, the share of neurological and cardiological examinations is 20% to 30%. The detecting systems make for in vivo resolution at the level of 2 mm. (M.D.)

  10. Acute neuroinflammation in a clinically relevant focal cortical ischemic stroke model in rat: longitudinal positron emission tomography and immunofluorescent tracking.

    Science.gov (United States)

    Tóth, Miklós; Little, Philip; Arnberg, Fabian; Häggkvist, Jenny; Mulder, Jan; Halldin, Christer; Gulyás, Balázs; Holmin, Staffan

    2016-04-01

    Adequate estimation of neuroinflammatory processes following ischemic stroke is essential for better understanding of disease mechanisms, and for the development of treatment strategies. With the TSPO (18 kDa translocator protein) positron emission tomography (PET) radioligand [(11)C]PBR28, we monitored longitudinally the inflammatory response post-transient cerebral ischemia in rats, using a recently developed rat stroke model that produces isolated focal cortical infarcts with clinical relevance in size and pathophysiology. Six Sprague-Dawley rats were subjected to 90 min transient endovascular occlusion of the M2 segment of the middle cerebral artery (M2CAO). Animals were imaged with a nanoScan(®) PET/MRI system at 1, 4, 7 and 14 days after M2CAO with a bolus injection of [(11)C]PBR28. In the infarct region, we found a significantly increased uptake of [(11)C]PBR28 on day 4, 7 and 14 compared to day 1 as well as compared to the contralateral cortex. No significant increase was detected in the contralateral cortex during the 14 days of imaging. The activation in the infarct region gradually decreased between day 4 and day 14. In an additional group of animals (n = 26), immunofluorescence studies were performed with antibodies for activated microglia/monocytes (Cd11b), phagocytes (Cd68), astrocytes (glial fibrillary acidic protein) and TSPO. The TSPO immunofluorescence signal indicated reactive microgliosis post injury, corresponding to PET findings. The present clinically relevant animal model and TSPO PET ligand appear to be well suited for studies on neuroinflammation after ischemic stroke. PMID:25601153

  11. The clinical significance of incidental intra-abdominal findings on positron emission tomography performed to investigate pulmonary nodules

    Directory of Open Access Journals (Sweden)

    Gill Richdeep S

    2012-01-01

    Full Text Available Abstract Background Lung cancer is a common cause of cancer-related death. Staging typically includes positron emission tomography (PET scanning, in which18F-fluoro-2-dexoy-D-glucose (FDG is taken up by cells proportional to metabolic activity, thus aiding in differentiating benign and malignant pulmonary nodules. Uptake of FDG can also occur in the abdomen. The clinical significance of incidental intraabdominal FDG uptake in the setting of pulmonary nodules is not well established. Our objective was to report on the clinical significance of incidental intra-abdominal FDG activity in the setting of lung cancer. Methods Fifteen hundred FDG-PET reports for studies performed for lung cancer were retrospectively reviewed for the presence of incidental FDG-positive intraabdominal findings. Patient charts with positive findings were then reviewed and information extracted. Results Twenty-five patients (25/1500 demonstrated incidental intraabdominal FDG uptake thought to be significant (1.7% with a mean patient age of 71 years. Colonic uptake was most common (n = 17 with 9 (52% being investigated further. Of these 9 cases, a diagnosis of malignancy was made in 3 patients, pre-malignant adenomas in 2 patients, a benign lipoma in 1 patient and no abnormal findings in the remaining patients. 8 patients were not investigated further (3 diagnosed with metastatic lung cancer and 2 were of advanced age secondary to poor prognosis. Conclusion Incidental abdominal findings in the colon on FDG-PET scan for work-up of pulmonary nodules need to be further investigated by colonoscopy.

  12. Positron emission tomography in the Rett syndrome; Clinical, biochemical and pathologicl correlates

    Energy Technology Data Exchange (ETDEWEB)

    Naidu, S. (Kennedy Institute, Baltimore, MD (United States)); Wong, D.F.; Kitt, C.; Wenk, G.; Moser, H.W.

    1992-05-01

    A consistent constellation of clinical signs and symptoms define the Rett syndrome, the most prominent of which are disorders of movement and tone. Preliminary pathologic and neurochemical data indicate predominant involvement of the nigrostriatal dopaminergic pathways and the cholinergic system of the basal forebrain region. The age of onset differentiates the Rett syndrome from Alzheimer and Parkinson disease with similar lesions. PET scanning makes it possible to relate the chemistry of the brain to function by measuring the number and affinity of neuroreceptors, metabolism in specific brain regions, and provide important determinants of the underlying mechanisms in disease states. (author).

  13. Clinical Application of In-Room Positron Emission Tomography for In Vivo Treatment Monitoring in Proton Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Min, Chul Hee [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Zhu, Xuping [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Winey, Brian A. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Grogg, Kira [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Testa, Mauro [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); El Fakhri, Georges [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Bortfeld, Thomas R.; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Shih, Helen A., E-mail: hshih@partners.org [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)

    2013-05-01

    Purpose: The purpose of this study is to evaluate the potential of using in-room positron emission tomography (PET) for treatment verification in proton therapy and for deriving suitable PET scan times. Methods and Materials: Nine patients undergoing passive scattering proton therapy underwent scanning immediately after treatment with an in-room PET scanner. The scanner was positioned next to the treatment head after treatment. The Monte Carlo (MC) method was used to reproduce PET activities for each patient. To assess the proton beam range uncertainty, we designed a novel concept in which the measured PET activity surface distal to the target at the end of range was compared with MC predictions. The repositioning of patients for the PET scan took, on average, approximately 2 minutes. The PET images were reconstructed considering varying scan times to test the scan time dependency of the method. Results: The measured PET images show overall good spatial correlations with MC predictions. Some discrepancies could be attributed to uncertainties in the local elemental composition and biological washout. For 8 patients treated with a single field, the average range differences between PET measurements and computed tomography (CT) image-based MC results were <5 mm (<3 mm for 6 of 8 patients) and root-mean-square deviations were 4 to 11 mm with PET-CT image co-registration errors of approximately 2 mm. Our results also show that a short-length PET scan of 5 minutes can yield results similar to those of a 20-minute PET scan. Conclusions: Our first clinical trials in 9 patients using an in-room PET system demonstrated its potential for in vivo treatment monitoring in proton therapy. For a quantitative range prediction with arbitrary shape of target volume, we suggest using the distal PET activity surface.

  14. Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging in Patients With Carcinoma of the Nasopharynx: Diagnostic Accuracy and Impact on Clinical Management

    International Nuclear Information System (INIS)

    Purpose: To assess the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma as compared with PET and conventional imaging (CI) alone, and to assess the impact of PET/CT on further clinical management. Methods and Materials: Thirty-three patients with nasopharyngeal carcinoma had 45 PET/CT examinations. The study was a retrospective analysis. Changes in patient care resulting from the PET/CT studies were recorded. Results: Positron emission tomography/computed tomography had sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 92%, 90%, 90%, 90%, and 91%, respectively, as compared with 92%, 65%, 76%, 86%, and 80% for PET and 92%, 15%, 60%, 60%, and 60% for CI. Imaging with PET/CT altered further management of 19 patients (57%). Imaging with PET/CT eliminated the need for previously planned diagnostic procedures in 11 patients, induced a change in the planned therapeutic approach in 5 patients, and guided biopsy to a specific metabolically active area inside an edematous region in 3 patients, thus decreasing the chances for tissue sampling errors and avoiding damage to nonmalignant tissue. Conclusions: In cancer of the nasopharynx, the diagnostic performance of PET/CT is better than that of stand-alone PET or CI. Positron emission tomography/computed tomography had a major impact on further clinical management in 57% of patients

  15. A clinical positron emission tomography facility. 2-{sup 18}FDG studies: Development and results

    Energy Technology Data Exchange (ETDEWEB)

    Ohlsson, Tomas

    1996-10-01

    Two different types of accelerators have been used for production of ({sup 18}F)fluoride, and the isotope produced has been used for radiolabelling of 2-fluoro-2-deoxy-D-glucose (2-{sup 18}FDG). A rotating PET scanner, based on two scintillation camera heads, has been developed and used for human 2-{sup 18}FDG studies. The suitability of an energy window in the Compton region for imaging 511 keV photons in scintillation camera systems has been evaluated. A new simplified method for normalizing clinical 2-{sup 18}FDG results has been developed and validated, using erythrocytes as a reference tissue, requiring only one blood sample in the middle of the PET scan to calculate the integrated 2-{sup 18}FDG input function with an accuracy better than 8 percent. An investigation using 2-{sup 18}FDG PET to monitor the effect of therapy in advanced head and neck cancer patients has been performed. We found that low initial metabolic rate of glucose (MRG) predicted a complete local response. The second PET examination gave no further information for this group. In the group of primary tumours and lymph node metastases representing a combination of high initial MRG and small decrease in MRG at he second PET examination, the outcome was unfavourable. An accurate normalization of 2-{sup 18}FDG uptake was essential to evaluate the results of this study. 239 refs, 10 tabs.

  16. A clinical positron emission tomography facility. 2-18FDG studies: Development and results

    International Nuclear Information System (INIS)

    Two different types of accelerators have been used for production of (18F)fluoride, and the isotope produced has been used for radiolabelling of 2-fluoro-2-deoxy-D-glucose (2-18FDG). A rotating PET scanner, based on two scintillation camera heads, has been developed and used for human 2-18FDG studies. The suitability of an energy window in the Compton region for imaging 511 keV photons in scintillation camera systems has been evaluated. A new simplified method for normalizing clinical 2-18FDG results has been developed and validated, using erythrocytes as a reference tissue, requiring only one blood sample in the middle of the PET scan to calculate the integrated 2-18FDG input function with an accuracy better than 8 percent. An investigation using 2-18FDG PET to monitor the effect of therapy in advanced head and neck cancer patients has been performed. We found that low initial metabolic rate of glucose (MRG) predicted a complete local response. The second PET examination gave no further information for this group. In the group of primary tumours and lymph node metastases representing a combination of high initial MRG and small decrease in MRG at he second PET examination, the outcome was unfavourable. An accurate normalization of 2-18FDG uptake was essential to evaluate the results of this study. 239 refs, 10 tabs

  17. Outcomes of Positron Emission Tomography–Staged Clinical N3 Breast Cancer Treated With Neoadjuvant Chemotherapy, Surgery, and Radiotherapy

    International Nuclear Information System (INIS)

    Purpose: To evaluate the treatment outcome and efficacy of regional lymph node irradiation after neoadjuvant chemotherapy (NCT) and surgery in positron emission tomography (PET)–positive clinical N3 (cN3) breast cancer patients. Methods and Materials: A total of 55 patients with ipsilateral infraclavicular (ICL), internal mammary (IMN), or supraclavicular (SCL) lymph node involvement in the absence of distant metastases, as revealed by an initial PET scan, were retrospectively analyzed. The clinical nodal stage at diagnosis (2002 AJCC) was cN3a in 14 patients (26%), cN3b in 12 patients (22%), and cN3c in 29 patients (53%). All patients were treated with NCT, followed by mastectomy or breast-conserving surgery and subsequent radiotherapy (RT) with curative intent. Results: At the median follow-up of 38 months (range, 9–80 months), 20 patients (36%) had developed treatment failures, including distant metastases either alone or combined with locoregional recurrences that included one ipsilateral breast recurrence (IBR), six regional failures (RF), and one case of combined IBR and RF. Only 3 patients (5.5%) exhibited treatment failure at the initial PET-positive clinical N3 lymph node. The 5-year locoregional relapse-free survival, disease-free survival (DFS), and overall survival rates were 80%, 60%, and 79%, respectively. RT delivered to PET-positive IMN regions in cN3b patients and at higher doses (≥55 Gy) to SCL regions in cN3c patients was not associated with improved 5-year IMN/SCL relapse-free survival or DFS. Conclusion: NCT followed by surgery and RT, including the regional lymph nodes, resulted in excellent locoregional control for patients with PET-positive cN3 breast cancer. The primary treatment failure in this group was due to distant metastasis rather than RF. Neither higher-dose RT directed at PET-positive SCL nodes nor coverage of PET-positive IMN nodes was associated with additional gains in locoregional control or DFS.

  18. Positron emission tomography and migraine

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a brain imaging technique that allows in vivo studies of numerous physiological parameters. There have been few PET studies in migraine patients. Cerebral blood flow changes with no variations in brain oxygen consumption have been reported in patients with prolonged neurologic manifestations during migraine attacks. Parenteral administration of reserpine during migraine headache has been followed by a fall in the overall cerebral uptake of glucose. The small sample sizes and a number of methodologic problems complicate the interpretation of these results. Recent technical advances and the development of new PET tracers can be expected to provide further insight into the pathophysiology of migraine. Today cerebral cortex 5 HT2 serotonin receptors can be studied in migraine patients with PET

  19. Positron emission tomography wrist detector

    Science.gov (United States)

    Schlyer, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois

    2006-08-15

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal representing a time-of-occurrence of an annihilation event, generating an address signal representing a channel detecting the annihilation event, and generating a channel signal including the time and address signals. The method also includes generating a composite signal including the channel signal and another similarly generated channel signal concerning another annihilation event. An apparatus that serially transfers annihilation information includes a time signal generator, address signal generator, channel signal generator, and composite signal generator. The time signal is asynchronous and the address signal is synchronous to a clock signal. A PET scanner includes a scintillation array, detection array, front-end array, and a serial encoder. The serial encoders include the time signal generator, address signal generator, channel signal generator, and composite signal generator.

  20. Professional practice assessment. Pertinence of positron emission tomography clinical indications in oncology; Evaluation des pratiques professionnelles. Pertinence des indications de la tomographie a emission de positons en cancerologie

    Energy Technology Data Exchange (ETDEWEB)

    Le Stanc, E.; Tainturier, C. [Hopital Foch, Service de Medecine Nucleaire, 92 - Suresnes (France); Swaenepoel, J. [Hopital Foch, Cellule Qualite, 92 - Suresnes (France)

    2009-09-15

    Introduction As part of the health care quality and safety policy in France, Professional Practice Assessment (P.P.A.) are mandatory in the health services 'certification' process. We present our study regarding the pertinence of Positron Emission Tomography (PET) indications in oncology. Materials and methods A multidisciplinary task group used the Quick Audit method with two rounds of 100 request forms each. The assessment list of criteria comprised four items of decreasing relevance grading the PET scans clinical indications, which were derived from the three French published guidelines (S.O.R. [F.N.C.L.C.C]., 'Guide du bon usage des examens d'imagerie medicale' [S.F.R.-S.F.M.N.], 'Guide pour la redaction de protocoles pour la TEP au F.D.G. en cancerologie' [S.F.M.N.]) and five additional items: clinical information, patient's body weight, previous treatments dates, diabetes, claustrophobia. Results The first round showed that 68% of the requested scans corresponded to the two most relevant groups of indications (S.O.R. Standards and Options). The request forms were correctly filled in regarding the clinical information, but this was not the case for the other items we tested. Several actions were conducted: dedicated PET request form, availability of the S.O.R. on the hospital intranet, boost of the referring physicians awareness during the multidisciplinary oncology meetings (Reunions de Concertation Pluridisciplinaires RCP). The second round showed a better pertinence of the PET scans indications (75% versus 68%); the patient's body weight was more frequently mentioned on the request form. Discussion This study is an example of P.P.A. in our discipline. It led to an improvement of the oncologic PET scans clinical indications in our hospital. This work is pursued in everyday discussion with the referring clinicians, especially during the RCP. (authors)

  1. Scintillators for positron emission tomography

    International Nuclear Information System (INIS)

    Like most applications that utilize scintillators for gamma detection, Positron Emission Tomography (PET) desires materials with high light output, short decay time, and excellent stopping power that are also inexpensive, mechanically rugged, and chemically inert. Realizing that this ''ultimate'' scintillator may not exist, this paper evaluates the relative importance of these qualities and describes their impact on the imaging performance of PET. The most important PET scintillator quality is the ability to absorb 511 keV photons in a small volume, which affects the spatial resolution of the camera. The dominant factor is a short attenuation length (≤ 1.5 cm is required), although a high photoelectric fraction is also important (> 30% is desired). The next most important quality is a short decay time, which affects both the dead time and the coincidence timing resolution. Detection rates for single 511 keV photons can be extremely high, so decay times ≤ 500 ns are essential to avoid dead time losses. In addition, positron annihilations are identified by time coincidence so ≤5 ns fwhm coincidence pair timing resolution is required to identify events with narrow coincidence windows, reducing contamination due to accidental coincidences. Current trends in PET cameras are toward septaless, ''fully-3D'' cameras, which have significantly higher count rates than conventional 2-D cameras and so place higher demands on scintillator decay time. Light output affects energy resolution, and thus the ability of the camera to identify and reject events where the initial 511 keV photon has undergone Compton scatter in the patient. The scatter to true event fraction is much higher in fully-3D cameras than in 2-D cameras, so future PET cameras would benefit from scintillators with a 511 keV energy resolution < 10--12% fwhm

  2. Bioimpedance-based respiratory gating method for oncologic positron emission tomography (PET) imaging with first clinical results

    International Nuclear Information System (INIS)

    Respiratory motion may cause significant image artefacts in positron emission tomography/computed tomography (PET/CT) imaging. This study introduces a new bioimpedance-based gating method for minimizing respiratory artefacts. The method was studied in 12 oncologic patients by evaluating the following three parameters: maximum metabolic activity of radiopharmaceutical accumulations, the size of these targets as well as their target-to-background ratio. The bioimpedance-gated images were compared with non-gated images and images that were gated with a reference method, chest wall motion monitoring by infrared camera. The bioimpedance method showed clear improvement as increased metabolic activity and decreased target volume compared to non-gated images and produced consistent results with the reference method. Thus, the method may have great potential in the future of respiratory gating in nuclear medicine imaging.

  3. Bioimpedance-based respiratory gating method for oncologic positron emission tomography (PET) imaging with first clinical results

    Science.gov (United States)

    Koivumäki, T.; Vauhkonen, M.; Teuho, J.; Teräs, M.; Hakulinen, M. A.

    2013-04-01

    Respiratory motion may cause significant image artefacts in positron emission tomography/computed tomography (PET/CT) imaging. This study introduces a new bioimpedance-based gating method for minimizing respiratory artefacts. The method was studied in 12 oncologic patients by evaluating the following three parameters: maximum metabolic activity of radiopharmaceutical accumulations, the size of these targets as well as their target-to-background ratio. The bioimpedance-gated images were compared with non-gated images and images that were gated with a reference method, chest wall motion monitoring by infrared camera. The bioimpedance method showed clear improvement as increased metabolic activity and decreased target volume compared to non-gated images and produced consistent results with the reference method. Thus, the method may have great potential in the future of respiratory gating in nuclear medicine imaging.

  4. Positron emission tomography in epilepsy

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) was performed with the 18F-fluoro-deoxy-glucose method on 29 patients with epilepsy (generalized epilepsy, 4; partial epilepsy, 24; undetermined type, 1). The subjects were restricted to patients with epilepsy without focal abnormality on X-CT. All the patients with generalized epilepsy showed a normal pattern on PET. Fourteen out of the 24 patients with partial epilepsy and the 1 with epilepsy of undermined type showed focal hypometabolism on PET. The hypometabolic zone was localized in areas including the temporal cortex in 11 patients, frontal in 2 and thalamus in 1. The location of hypometabolic zone and that of interictal paroxysmal activity on EEG were well correlated in most patients. The patients with poorly-controlled seizure showed a higher incidence of PET abnormality (12 out of 13) than those with well-controlled seizures (2 out of 11). The incidence of abnormality on PET and MRI and the location of both abnormality were not necessarily coincident. These results indicated that the PET examination in epilepsy provides valuable information about the location of epileptic focus, and that the findings on PET in patients with partial epilepsy may be one of the good indicators about the intractability of partial epilepsy, and that PET and MRI provide complementary information in the diagnosis of epilepsy. (author)

  5. Highly metabolic thrombus of the portal vein: 18F fluorodeoxyglucose positron emission tomography/computer tomography demonstration and clinical significance in hepatocellular carcinoma

    OpenAIRE

    Sun, Long; Guan, Yong-Song; Pan, Wei-Ming; Chen, Gui-Bing; Luo, Zuo-Ming; Wei, Ji-Hong; Wu, Hua

    2008-01-01

    AIM: To assess the ability of 18F-fluorodeoxyglucose positron emission tomography/computer tomography (18F-FDG PET/CT) to differentiate between benign and malignant portal vein thrombosis in hepatocellular carcinoma (HCC) patients.

  6. Evaluation of fluorine-18-fluorodeoxyglucose whole body positron emission tomography imaging in the clinical diagnosis of lung cancer

    International Nuclear Information System (INIS)

    In recent years the use of positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose (FDG) has become a valuable tool in the detection of a variety of tumors including lung cancer. To determine its role in the diagnosis of patients with suspected lung cancer, we compared the results of FDG-PET with those of the other scintigraphic imaging techniques (67Ga-planar image, 201T1-SPECT and 99mTc-bone scintigraphy) used worldwide in patients with lung cancer. The analysis group consists of 178 patients, 159 malignant pulmonary diseases and 19 benign pulmonary diseases. FDG-PET was performed in 65 patients (51 malignant pulmonary diseases, 14 benign pulmonary diseases). FDG-PET had a sensitivity, specificity and accuracy of 98.0%, 78.6% and 93.8%, respectively, in detecting malignant pulmonary nodules. In N staging, sensitivity, specificity and accuracy were 66.7%, 81.3% and 76.0%, respectively. In M staging, the accuracy was 100%. Thus, FDG-PET imaging was more accurate than the other types of scintigraphic imaging. In our observations, whole-body 18FDG-PET images improved diagnostic accuracy in the evaluation of lung lesions and the staging of lung cancer. (author)

  7. Preclinical and clinical evaluation of O-[{sup 11}C]methyl-L-tyrosine for tumor imaging by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ishiwata, Kiichi [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan)]. E-mail: ishiwata@pet.tmig.or.jp; Tsukada, Hideo [Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita 434-8601 (Japan); Kubota, Kazuo [Department of Radiology, Division of Nuclear Medicine, International Medical Center of Japan, Shinjuku-ku, Tokyo 162-8655 (Japan); Nariai, Tadashi [Department of Neurosurgery, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8519 (Japan); Harada, Norihiro [Department of Radiology, Division of Nuclear Medicine, International Medical Center of Japan, Shinjuku-ku, Tokyo 162-8655 (Japan); Kawamura, Kazunori [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan); SHI Accelerator Service Ltd., Shinagawa-ku, Tokyo 141-8686 (Japan); Kimura, Yuichi [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan); Oda, Keiichi [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan); Iwata, Ren [CYRIC, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan)

    2005-04-01

    We performed preclinical and clinical studies of O-[{sup 11}C]methyl-L-tyrosine, a potential tracer for imaging amino acid transport of tumors by positron emission tomography (PET). Examinations of the radiation-absorbed dose by O-[{sup 11}C]methyl-L-tyrosine and the acute toxicity and mutagenicity of O-methyl-L-tyrosine showed suitability of the tracer for clinical use. The whole-body imaging of monkeys and healthy humans by PET showed low uptake of O-[{sup 11}C]methyl-L-tyrosine in all normal organs except for the urinary track and bladder, suggesting that the O-[{sup 11}C]methyl-L-tyrosine PET has the potential for tumor imaging in the whole-body. Finally, the brain tumor imaging was preliminarily demonstrated.

  8. Motion correction in thoracic positron emission tomography

    CERN Document Server

    Gigengack, Fabian; Dawood, Mohammad; Schäfers, Klaus P

    2015-01-01

    Respiratory and cardiac motion leads to image degradation in Positron Emission Tomography (PET), which impairs quantification. In this book, the authors present approaches to motion estimation and motion correction in thoracic PET. The approaches for motion estimation are based on dual gating and mass-preserving image registration (VAMPIRE) and mass-preserving optical flow (MPOF). With mass-preservation, image intensity modulations caused by highly non-rigid cardiac motion are accounted for. Within the image registration framework different data terms, different variants of regularization and parametric and non-parametric motion models are examined. Within the optical flow framework, different data terms and further non-quadratic penalization are also discussed. The approaches for motion correction particularly focus on pipelines in dual gated PET. A quantitative evaluation of the proposed approaches is performed on software phantom data with accompanied ground-truth motion information. Further, clinical appl...

  9. Positron emission tomography: radioisotope and radiopharmaceutical production

    International Nuclear Information System (INIS)

    A Centre for Positron Emission Tomography (PET) has been operational within the Department of Nuclear Medicine at the Austin and Repatriation Medical Centre (A and RMC) in Melbourne for seven years. PET is a non-invasive imaging technique based on the use of biologically relevant compounds labelled with short-lived positron-emitting radionuclides such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18. The basic facility consists of a medical cyclotron (10 MeV proton and 5 MeV deuteron), six lead-shielded hot cells with associated radiochemistry facilities, radiopharmacy and a whole body PET scanner. A strong radiolabelling development program, including the production of 15O-oxygen, 15O-carbon monoxide, 15O-carbon dioxide, 15O-water, 13N-ammonia, 18F-FDG, 18F-FMISO, 11C-SCH23390 and 11C-flumazenil has been pursued to support an ambitious clinical and research program in neurology, oncology, cardiology and psychiatry. Copyright (1999) Australasian Physical and Engineering Sciences in Medicine and the College of Biomedical Engineers

  10. Cyclotron, positrons and PET [positron emission tomography]. An overview

    International Nuclear Information System (INIS)

    PET (positron emission tomography) is a powerful new scientific tool which is capable of revealing biochemical transformations while they are occurring in the brain and other organs in the living human body. The application of PET to problems in biology and medicine is dominated by the short half-life of the isotopes used to prepare the radiotracers. The most commonly used positron emitting isotopes are carbon-11, fluorine-18, nitrogen-13, and oxygen-15 which have half-lives of 20.4, 110, 10 and 2 minutes, respectively. Their incorporation into radiotracers having diverse chemical structures and biochemical specificities has allowed the study of blood flow, sugar metabolism, oxygen metabolism, neurotransmission, enzyme activity and binding sites for therapeutic drugs and substances of abuse. PET research is most commonly carried out at a Cyclotron-PET Center (cyclotron, positron emission tomography, chemistry laboratory) where the short-lived isotopes can be produced and used efficiently. The number of Cyclotron-PET Centers has grown from 4 in 1976 to several dozen in 1988 and the number is expected to double in the next five years attesting to the vitality of the field and the current and anticipated contributions to research in biology and medicine

  11. Amyloid-β positron emission tomography imaging probes

    DEFF Research Database (Denmark)

    Kepe, Vladimir; Moghbel, Mateen C; Långström, Bengt;

    2013-01-01

    number of factors appear to preclude these probes from clinical utilization. As the available "amyloid specific" positron emission tomography imaging probes have failed to demonstrate diagnostic value and have shown limited utility for monitoring therapeutic interventions in humans, a debate on their...

  12. Positron emission tomography/computerized tomography in lung cancer

    OpenAIRE

    Sahiner, Ilgin; Vural, Gulin Ucmak

    2014-01-01

    Positron emission tomography (PET) using 2-(18F)-flouro-2-deoxy-D-glucose (FDG) has emerged as a useful tool in the clinical work-up of lung cancer. This review article provides an overview of applications of PET in diagnosis, staging, treatment response evaluation, radiotherapy planning, recurrence assessment and prognostication of lung cancer.

  13. Simultaneous emission and transmission scanning in positron emission tomography

    International Nuclear Information System (INIS)

    Examination by PET (positron emission tomography) scanning, following the dosage of 2-deoxy-18F fluoro-D-glucose (FDG), is positively utilized for the diagnosis of cancers, rather than for the purpose of studies. This is because the examination by FDG-PET (PET scanning following the dosage of FDG) ensures higher efficiency in discrimination of cancers, than conventional CT and PET. The method of whole body scanning by PET scanning following the dosage of FDG is effectively utilized not only for discrimination cancers, but also for determining the degree of malignancy of tumors and evaluating the methods of treatment of cancers. In conventional methods for examining the degree of malignancy of tumors and evaluating the methods of cancer treatment, it is necessary to correct for the gamma-ray attenuation, which requires a longer time for examination, increasing the physical and psychological pains of the patients. We have installed the simultaneous emission and transmission scanning capability into the HEADTOME-V of the Shimadzu SET-2000W Series positron emission tomographic scanning instruments, to establish an instrument that permits FDG-PET whole body scanning in actual clinical fields, with minimized physical and psychological pains of patients concerned, yet ensuring an outstandingly high examination efficiency. This report also presents some data obtained by this newly developed instrument and those obtained in practical applications. (author)

  14. 'Serial review on clinical PET tracers'. Dopamine D2 receptor imaging by positron emission tomography with [11C]N-methylspiperone and [11C]raclopride

    International Nuclear Information System (INIS)

    Dopamine D2 receptor binding is one of postsynaptic functions of dopaminergic neurotransmission system, and it can be estimated by positron emission tomography (PET) with [11C]raclopride and [11C]N-methylspiperone. The dopaminergic neurotransmission system is of central interest in pathophysiology of neuropsychiatric disorders, e.g., Parkinson's disease and schizophrenia. Measurement of binding potential (BPND) of [11C]raclopride to dopamine D2 receptors is useful for differential diagnosis of Parkinson's disease from other neurodegenerative diseases. Effects of antipsychotic drugs have widely been considered to be mediated by blockade of dopamine D2 receptors, and occupancy of dopamine D2 receptor by antipsychotic drug can be calculated from BPND of [11C]raclopride at baseline and drug challenge studies. Measurement of dopamine D2 receptor occupancy is useful for evaluation of effects of antipsychotic drug. It can also be applied for optimal dose finding of new antipsychotic drug in clinical trials. (author)

  15. Ionization and positron emission in giant quasiatoms

    International Nuclear Information System (INIS)

    Electron excitation processes in superheavy quasiatoms are treated within a relativistic framework. Theoretical results on K-hole production rates as well as delta-electron and positron spectra are compared with experimental data. It is demonstrated that the study of heavy ion collisions with nuclear time delay promises a signature for the spontaneous positron formation in overcritical systems. Corresponding experimental results are confronted with our theoretical hypothesis. Recent speculations on the origin of the observed peak structures in positron spectra are critically reviewed. Atomic excitations are also employed to obtain information on the course of a nuclear reaction. Using a semiclassical picture we calculate the emission of delta-electrons and positrons in deep-inelastic nuclear reactions. Furthermore some consequences of conversion processes in giant systems are investigated. (orig.)

  16. Positron emission tomography imaging of gene expression

    International Nuclear Information System (INIS)

    The merging of molecular biology and nuclear medicine is developed into molecular nuclear medicine. Positron emission tomography (PET) of gene expression in molecular nuclear medicine has become an attractive area. Positron emission tomography imaging gene expression includes the antisense PET imaging and the reporter gene PET imaging. It is likely that the antisense PET imaging will lag behind the reporter gene PET imaging because of the numerous issues that have not yet to be resolved with this approach. The reporter gene PET imaging has wide application into animal experimental research and human applications of this approach will likely be reported soon

  17. Advanced instrumentation for Positron Emission Tomography

    International Nuclear Information System (INIS)

    This paper summarizes the physical processes and medical science goals that underly modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost. 71 refs., 3 figs., 3 tabs

  18. Advanced Instrumentation for Positron Emission Tomography [PET

    Science.gov (United States)

    Derenzo, S. E.; Budinger, T. F.

    1985-04-01

    This paper summarizes the physical processes and medical science goals that underlay modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost.

  19. Utility of positron emission tomography in schwannomatosis.

    Science.gov (United States)

    Lieber, Bryan; Han, ByoungJun; Allen, Jeffrey; Fatterpekar, Girish; Agarwal, Nitin; Kazemi, Noojan; Zagzag, David

    2016-08-01

    Schwannomatosis is characterized by multiple non-intradermal schwannomas with patients often presenting with a painful mass in their extremities. In this syndrome malignant transformation of schwannomas is rare in spite of their large size at presentation. Non-invasive measures of assessing the biological behavior of plexiform neurofibromas in neurofibromatosis type 1 such as positron emission tomography (PET), CT scanning and MRI are well characterized but little information has been published on the use of PET imaging in schwannomatosis. We report a unique clinical presentation portraying the use of PET imaging in schwannomatosis. A 27-year-old woman presented with multiple, rapidly growing, large and painful schwannomas confirmed to be related to a constitutional mutation in the SMARCB1 complex. Whole body PET/MRI revealed numerous PET-avid tumors suggestive of malignant peripheral nerve sheath tumors. Surgery was performed on multiple tumors and none of them had histologic evidence of malignant transformation. Overall, PET imaging may not be a reliable predictor of malignant transformation in schwannomatosis, tempering enthusiasm for surgical interventions for tumors not producing significant clinical signs or symptoms. PMID:26960263

  20. Clinical applications of positron scanning

    International Nuclear Information System (INIS)

    There are only a few ways in which the radiopharmaceuticals carrying the positron-emitting isotope can be applied. a. intravenous bolus injection, b. continuous intravenous injection until equilibrium is reached, c. inhalation of a bolus of radioactive gases, d. continuous inhalation until equilibrium is reached. (orig./VJ)

  1. Beyond FDG positron emission tomography imaging

    International Nuclear Information System (INIS)

    At present, positron emission tomography/computed tomography (PET/CT) is one of the most rapidly growing areas of medical imaging, with many applications in the clinical management of patients with cancer. Although ((18)F) fluorodeoxyglucose (FDG)-PET/CT imaging provides high specificity and sensitivity in several kinds of cancer and has many applications, it is important to recognize that FDG is not a 'specific' radiotracer for imaging malignant disease. Highly 'tumor-specific' PET radiopharmaceuticals are essential to meet the growing demand of radioisotope-based molecular imaging technology. C-11 Methionine PET has been used to better define the radiotherapy field both for CNS tumors and head and neck (H and N) tumors to localize the most metabolic area inside a brain mass to guide the biopsy or in early evaluation of radiotherapy effect on H and N cancer. Flurodihydroxyphenylalanine (FDOPA) is an aromatic amino acid labelled with 18F. Besides it has also been introduced into oncological practice, in particular for malignant tumors of neural crest origin

  2. Resistive plate chambers in positron emission tomography

    Science.gov (United States)

    Crespo, Paulo; Blanco, Alberto; Couceiro, Miguel; Ferreira, Nuno C.; Lopes, Luís; Martins, Paulo; Ferreira Marques, Rui; Fonte, Paulo

    2013-07-01

    Resistive plate chambers (RPC) were originally deployed for high energy physics. Realizing how their properties match the needs of nuclear medicine, a LIP team proposed applying RPCs to both preclinical and clinical positron emission tomography (RPC-PET). We show a large-area RPC-PET simulated scanner covering an axial length of 2.4m —slightly superior to the height of the human body— allowing for whole-body, single-bed RPC-PET acquisitions. Simulations following NEMA (National Electrical Manufacturers Association, USA) protocols yield a system sensitivity at least one order of magnitude larger than present-day, commercial PET systems. Reconstruction of whole-body simulated data is feasible by using a dedicated, direct time-of-flight-based algorithm implemented onto an ordered subsets estimation maximization parallelized strategy. Whole-body RPC-PET patient images following the injection of only 2mCi of 18-fluorodesoxyglucose (FDG) are expected to be ready 7 minutes after the 6 minutes necessary for data acquisition. This compares to the 10-20mCi FDG presently injected for a PET scan, and to the uncomfortable 20-30minutes necessary for its data acquisition. In the preclinical field, two fully instrumented detector heads have been assembled aiming at a four-head-based, small-animal RPC-PET system. Images of a disk-shaped and a needle-like 22Na source show unprecedented sub-millimeter spatial resolution.

  3. Positron emission tomography of the lung

    International Nuclear Information System (INIS)

    Positron emission tomography enables the distribution of positron emitting isotopes to be imaged in a transverse plane through the body and the regional concentration of the isotope to be measured quantitatively. This thesis reports some applications of positron emission tomography to studies of pulmonary pathophysiology. Measurements in lung phantoms showed that regional lung density could be measured from a transmission tomogram obtained with an external source of positron emitting isotope. The regional, fractional blood volume was measured after labelling the blood with carbon-11-monoxide. Regional extravascular lung density (lung tissue and interstitial water per unit thoracic volume) was obtained by subtracting fractional blood volume from lung density. Measurements in normal subjects revealed large regional variations in lung density and fractional blood volume in the supine posture. Extravascular lung density showed a more uniform distribution. The technique has been used to study patients with chronic interstitial pulmonary oedema, pulmonary sarcoidosis and fibrosis, pulmonary arterial hypertension and patients with intracardiac, left-to-right shunt. Tomographic measurements of pulmonary tissue concentration of radionuclides are difficult, since corrections for the blood content and the inflation of the lung must be applied. A simultaneous measurement of lung density and fractional blood volume allows such corrections to be made and the extravascular tracer concentration to be calculated. This has been applied to measurements of the tissue penetration of carbon-11-labelled erythromycin in patients with lobar pneumonia. (author)

  4. Computed tomography and positron emission tomography/computed tomography surveillance after combined modality treatment of supradiaphragmatic Hodgkin lymphoma: a clinical and economic perspective.

    Science.gov (United States)

    Patel, Vatsal; Buckstein, Michael; Perini, Rodolfo; Hill-Kayser, Christine; Svoboda, Jakub; Plastaras, John P

    2013-10-01

    We studied the clinical benefits of radiological imaging, in the follow-up of patients after combined modality treatment for stage I/II classical supradiaphragmatic Hodgkin lymphoma (HL). Imaging data were collected for 78 adults treated during 1996-2008. Median follow-up was 4.6 years. Six of the nine relapses were detected clinically. On average, 31 imaging studies/patient were performed, with an estimated cost of $12 608/patient. Chest computed tomography (CT) scans accounted for 25%, abdominopelvic CT scans 41% and positron emission tomography (PET) or PET/CT scans 22% of this expense. Only one patient recurred infradiaphragmatically. The estimated radiation dose from imaging was 399 mSv and 229 mSv per patient, in relapse and non-relapse groups, respectively. CT scans contributed over 80% of the imaging radiation exposure. The routine use of CT scans in the surveillance of patients with HL after curative treatment adds to healthcare costs and total body radiation exposure with a low yield. History and physical examination remain effective tools for the follow-up of patients. PMID:23331161

  5. Positron emission tomography: a new paradigm in cancer management

    International Nuclear Information System (INIS)

    The National Cancer Institute (NCI) is currently building a positron emission tomography facility that will house a cyclotron and a PET fusion scanner. lt should be operational as of december 2007, being a cancer dedicated national referral center, the NCI should provide both positron-emitting radiopharmaceuticals and medical services to institutions and patients nationwide. PET technology provides metabolic information that has been documented to be useful in patient care. The properties of positron decay allow accurate imaging of the in vivo distribution of positron-emitting radiopharmaceuticals. a wide array of positron-emitting radiopharmaceuticals has been used to characterize multiple physiologic and pathologic states. The major clinical PET applications are in cancer patients using fluorine-18 fluorodeoxyglucose (FDG). FDG, an analogue of glucose, accumulates in most tumors in a greater amount than it does in normal tissue. PET is being used in diagnosis and follow-up of several malignancies, and the list of articles supporting its use continues to grow. in this article, the instrumentation aspects of PET are described and most of the clinical applications in oncology are described

  6. Incidental colorectal polyps in positron emission tomography

    International Nuclear Information System (INIS)

    Fluorodeoxy glucose positron emission tomography/computed tomography (FDG PET/CT) is increasingly being used for diagnosing various malignancies and surveillance of cancer recurrence, staging and screening in high-risk individuals. Due to its high sensitivity in picking up small dysplastic lesions, incidental lesions are detected frequently. We present two patients who underwent PET CT as part of cancer screening and were incidentally detected with adenomatous colonic polyps. Colonoscopy and biopsy confirmed the diagnosis

  7. Positron emission tomography (PET) for cholangiocarcinoma

    OpenAIRE

    Breitenstein, S; Apestegui, C.; Clavien, P.-A.

    2008-01-01

    The combination of positron emission tomography (PET) with computed tomography (PET-CT) provides simultaneous metabolic and anatomic information on tumors in the same imaging session. Sensitivity of PET/PET-CT is higher for intrahepatic (>90%) than for extrahepatic cholangiocarcinoma (CCA) (about 60%). The detection rate of distant metastasis is 100%. PET, and particularly PET-CT, improves the results and impacts on the oncological management in CCA compared with other imaging modalities. The...

  8. Spreadsheet program for estimating recovery coefficient to get partial volume corrected standardized uptake value in clinical positron emission tomography-computed tomography studies

    International Nuclear Information System (INIS)

    To develop a spreadsheet program for estimation of recovery coefficient (RC) to get partial volume corrected (PVC) standardized uptake value (SUV) in clinical positron emission tomography-computed tomography (PET-CT) studies. For formulation of this program we used data from a phantom study conducted at our center in which a phantom with a sphere assembly (seven spheres-different diameters) was filled with 18F-Fluorodeoxyglucose solution to get a sphere/background ratio of 8:1, 10:1 and 12:1. PET-CT images were acquired. RC was then calculated from processed PET-CT images. We plotted graph of RC versus lesion-size at different sphere/background ratio using MS Excel function. There was logarithmic increase in RC with increase in lesion size. We fitted the data with a logarithmic equation and found optimum fit (least-square fit). We then validated this program with clinical data using 42 lung nodules in five patients. The program estimates the value of RC and object to background ratio in PET-CT for the input lesion-size and displays graph with trendline. When the user enters SUV and background activity measured in clinical PET-CT, it provides the value of RC and PVC SUV. It also validates the data entry and displays appropriate message. It is consistent, reproducible, accurate and provides output for wide range of lesion-sizes (71% of lesions evaluated); however, program does not give output for lesion-size < 9 mm. The present spreadsheet program is a useful and easy tool for calculating PVC SUV of clinical PET-CT lesions

  9. A Case of Corticobasal Degeneration Studied with Positron Emission Tomography

    OpenAIRE

    Nagasawa, H; T. Imamura; Nomura, H; Itoh, M; Ido, T.

    1993-01-01

    We measured cerebral blood flow, oxygen metabolism, glucose utilization, and dopamine metabolism in the brain of a patient with corticobasal degeneration using positron emission tomography (PET). The clinical picture is distinctive, comprising features referable to both cortical and basal ganglionic dysfunction. Brain imagings of glucose and dopamine metabolism can demonstrate greater abnormalities in the cerebral cortex and in the striatum contralateral to the more affected side than those o...

  10. Clinical Usefulness of :18F 2-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography Scan in the Diagnosis of Ampullary Carcinoma

    International Nuclear Information System (INIS)

    To evaluate the clinical usefulness of the 18F 2-fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) scan in the diagnosis of the ampulla of Vater cancer. CT images of 39 patients with ampulla of Vater cancer were reviewed regarding the lesion size, location, and bile or pancreatic duct dilatation. The patients were divided into three groups according to the lesion visibility on CT (Group A: visible mass, Group B: no visible mass but prominent ampulla, Group C: no visible lesion). Standardized uptake value (SUV) was measured on PET scan and the detection rate on PET images was comparable with that of CT images. Twenty-four patients (61.5%) were classified as Group A, 11 (28.2%) as Group B and 4 (10.3%) as Group C. All of Group A, 10 (90.9%) of Group B and 3 (75.0%) of Group C showed biliary dilatation. Pancreatic duct dilatation was shown in 18 (75.0%) of Group A, 9 (81.8%) of Group B, and 1 (25.0%) of Group C. The average of SUV of all patients was 5.90 ± 3.1. Most (94.9%) of all patients showed high FDG uptake over 2.5 with 93.9% in Group B and C. '18F-FDG PET scan was use for the detection of ampulla of Vater cancer, even though the lesion was invisible on CT.

  11. Clinical Usefulness of :1{sup 8}F 2-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography Scan in the Diagnosis of Ampullary Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Se Jin; Chung, Jae Joon; Kim, Dae Jung; Cho, Eun Suk; Ahn, Jhii Hyun; Kim, Joo Jee; Yu, Jeong Sik [Dept. of Radiology, Gangnam Severance Hospital, Yensei University College of Medicine, Seoul (Korea, Republic of)

    2011-08-15

    To evaluate the clinical usefulness of the {sup 18}F 2-fluoro-2-deoxy-D-glucose positron emission tomography ({sup 18}F-FDG PET) scan in the diagnosis of the ampulla of Vater cancer. CT images of 39 patients with ampulla of Vater cancer were reviewed regarding the lesion size, location, and bile or pancreatic duct dilatation. The patients were divided into three groups according to the lesion visibility on CT (Group A: visible mass, Group B: no visible mass but prominent ampulla, Group C: no visible lesion). Standardized uptake value (SUV) was measured on PET scan and the detection rate on PET images was comparable with that of CT images. Twenty-four patients (61.5%) were classified as Group A, 11 (28.2%) as Group B and 4 (10.3%) as Group C. All of Group A, 10 (90.9%) of Group B and 3 (75.0%) of Group C showed biliary dilatation. Pancreatic duct dilatation was shown in 18 (75.0%) of Group A, 9 (81.8%) of Group B, and 1 (25.0%) of Group C. The average of SUV of all patients was 5.90 {+-} 3.1. Most (94.9%) of all patients showed high FDG uptake over 2.5 with 93.9% in Group B and C. '1{sup 8}F-FDG PET scan was use for the detection of ampulla of Vater cancer, even though the lesion was invisible on CT.

  12. Differentiation of clinically non-functioning pituitary adenomas from meningiomas and craniopharyngiomas by positron emission tomography with [18F]fluoro-ethyl-spiperone

    International Nuclear Information System (INIS)

    The differential diagnosis among various types of non-functioning sellar and parasellar tumours is sometimes difficult using currently available methods of morphological imaging. The aim of this study was to define whether assessment of the uptake of [18F]fluoro-ethyl-spiperone (FESP) with positron emission tomography (PET) could be helpful for the differential diagnosis of pituitary adenomas and other parasellar lesions, and for establishing the appropriate therapeutic approach. The population examined comprised 16 patients with the diagnosis of primary tumour of the sellar/parasellar region who were waiting to undergo surgical treatment. The results demonstrated that PET with [18F]FESP is a very specific method for differentiating adenomas from craniopharyngiomas and meningiomas. The visual interpretation of images allows such differentiation at approximately 70 min after tracer injection. Semiquantitative analysis of the dynamic PET data confirmed the results of visual interpretation, demonstrating that the uptake of [18F]FESP was consistently (i.e. throughout the series) at least two- to threefold higher in non-functioning adenomas than in other parasellar tumours as early as 70 min after tracer injection, and that it increased still further thereafter. It is concluded that PET with [18F]FESP might be of clinical value in those cases in which the differential diagnosis among various histological types of sellar tumour is uncertain with conventional methods. (orig.). With 3 figs., 1 tab

  13. Clinical value of whole-body F-18 fluorodeoxyglucose positron emission tomography / computed tomography in patients with carcinoma of unknown primary

    International Nuclear Information System (INIS)

    The purpose of the study is to investigate the clinical value of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in detecting the primary sites in patients with carcinoma of unknown primary (CUP). The reports of FDG PET/CT scans of 164 patients with CUP syndrome in consecutive 2589 patients referred to our department from January 2006 to June 2010 were retrospectively reviewed. The final results were obtained from the pathologic reports, other imaging modalities diagnoses and clinical follow-up data. There were 142 cases in the results analysis, as 19 patients were lost to follow-up and three patients were excluded. FDG PET/CT successfully detected primary tumours in 67 (47.2%) out of 142 patients. Among this group, 53 were pathologically proved and 17 patients were confirmed by clinical follow-up. The primary sites of 38 (56.7%) were in lung, eight (11.9%) in nasopharynx and 13 (19.4%) in digestive system. Six patients were misdiagnosed by FDG PET/CT scan. FDG PET/CT could not detect the primary lesion in 66 patients, and three primary tumours were identified by conventional work-up after negative FDG PET/CT scan. The accuracy, sensitivity and specificity of FDG PET/CT scan in detecting the primary site in this study were 93.7%, 95.7% and 91.7%, respectively. FDG PET/CT scan changed the medical management of about 33.8% of 142 CUP patients. FDG PET/CT whole-body imaging is a valuable tool in detecting the primary tumour of patients with CUP site.

  14. Shielding design for positron emission tomography facility

    International Nuclear Information System (INIS)

    With the recent advent of readily available tracer isotopes, there has been marked increase in the number of hospital-based and free-standing positron emission tomography (PET) clinics. PET facilities employ relatively large activities of high-energy photon emitting isotopes, which can be dangerous to the health of humans and animals. This coupled with the current dose limits for radiation worker and members of the public can result in shielding requirements. This research contributes to the calculation of the appropriate shielding to keep the level of radiation within an acceptable recommended limit. Two different methods were used including measurements made at selected points of an operating PET facility and computer simulations by using Monte Carlo Transport Code. The measurements mainly concerned the radiation exposure at different points around facility using the survey meter detectors and Thermoluminescent Dosimeters (TLD). Then the set of manual calculation procedures were used to estimate the shielding requirements for a newly built PEF facility. The results from the measurement and the computer simulation were compared to the results obtained from the set manual calculation procedure. In general, the estimated weekly dose at the points of interest is lower than the regulatory limits for the little company of Mary Hospital. Furthermore, the density and the HVL for normal strength concrete and clay bricks are almost similar. In conclusion, PET facilities present somewhat different design requirements and are more likely to require additional radiation shielding. Therefore, existing shields at the little Company of Mary Hospital are in general found to be adequate and satisfactory and additional shielding was found necessary at the new PET facility in the department of Nuclear Medicine of the Dr. George Mukhari Hospital. By use of appropriate design, by implying specific shielding requirements and by maintaining good operating practices, radiation doses to

  15. Clinical Usefulness of {sup 18}F-Fluorodeoxyglucose-Positron Emission Tomography in Patients With Locally Advanced Pancreatic Cancer Planned to Undergo Concurrent Chemoradiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jee Suk; Choi, Seo Hee; Lee, Youngin; Kim, Kyung Hwan [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Park, Jeong Youp; Song, Si Young [Department of Internal Medicine, Yonsei University College of Medicine, Seoul (Korea, Republic of); Cho, Arthur; Yun, Mijin; Lee, Jong Doo [Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul (Korea, Republic of); Seong, Jinsil, E-mail: jsseong@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2014-09-01

    Purpose: To assess the role of coregistered {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting radiographically occult distant metastasis (DM) at staging in patients with locally advanced pancreatic cancer (LAPC) and to study whether FDG-PET parameters can predict relatively long-term survival in patients who are more likely to benefit from chemoradiation therapy (CRT). Methods and Materials: From our institutional database, we identified 388 LAPC patients with M0 on conventional computed tomography (CT) who were planned to undergo CRT. Coregistered FDG-PET staging was offered to all patients, and follow-up FDG-PET was used at the clinical discretion of the physician. Results: FDG-PET detected unsuspected CT-occult DM in 33% of all 388 patients and allowed them to receive systemic therapy immediately. The remaining 260 patients (PET-M0) underwent CRT selectively as an initial treatment. Early DM arose in 13.1% of 260 patients, and the 1-year estimated locoregional recurrence rate was 5.4%. Median overall survival (OS) and progression-free survival (PFS) were 14.6 and 9.3 months, respectively, at a median follow-up time of 32.3 months (range, 10-99.1 months). Patients with a baseline standardized uptake value (SUV) <3.5 and/or SUV decline ≥60% had significantly better OS and PFS than those having none, even after adjustment for all potential confounding variables (all P<.001). Conclusions: FDG-PET can detect radiographically occult DM at staging in one-third of patients and spare them from the potentially toxic therapy. Additionally, FDG-PET parameters including baseline SUV and SUV changes may serve as useful clinical markers for predicting the prognosis in LAPC patients.

  16. Predicting amyloid status in corticobasal syndrome using modified clinical criteria, magnetic resonance imaging and fluorodeoxyglucose positron emission tomography

    OpenAIRE

    Sha, SJ; Ghosh, PM; Lee, Se; Corbetta-Rastelli, C; Jagust, WJ; Kornak, J.; Rankin, KP; Grinberg, LT; Vinter, HV; Mendez, MF; Dickson, DW; Seeley, WW; Gorno-Tempini, M; Kramer, J.; Miller, BL

    2015-01-01

    Introduction Group comparisons demonstrate greater visuospatial and memory deficits and temporoparietal-predominant degeneration on neuroimaging in patients with corticobasal syndrome (CBS) found to have Alzheimer’s disease (AD) pathology versus those with underlying frontotemporal lobar degeneration (FTLD). The value of these features in predicting underlying AD pathology in individual patients is unknown. The goal of this study is to evaluate the utility of modified clinical criteria and vi...

  17. Positron emission tomography of FDG in schizophrenia

    International Nuclear Information System (INIS)

    The use of the Donner dynamic positron emission tomograph to study fluorodeoxyglucose labelled 18F uptake in the brain of six patients with schizophrenia is reported. The glucose metabolic rate and the local cerebral metabolic rate were calculated. The dynamic brain uptake data and the blood input function were used to calculate rate constants by an iterative least squares fitting program for all regions of interest chosen in the brain. Although the number of patients was small, differences in k3 were statistically significant in several brain regions compared with normal controls

  18. Perspectives for positron emission tomography with RPCs

    International Nuclear Information System (INIS)

    In this study, we address the feasibility and main properties of a positron emission tomograph (PET) based on RPCs. The concept, making use of the converter-plate principle, takes advantage of the intrinsic layered structure of RPCs and its simple and economic construction. The extremely good time and position resolutions of RPCs also allow the TOF-PET imaging technique to be considered. Monte-Carlo simulations, supported by experimental data, are presented and the main advantages and drawbacks for applications of potential interest are discussed

  19. Positron Emission Tomography Imaging of Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Saravanan Kokila Krishnamoorthy

    2014-03-01

    Full Text Available Positron emission tomography (PET using 18F-fluorodeoxyglucose (FDG is increasingly used for the staging of solidmalignancies, including lung and esophagus. However, controversy still exists in relation to the application of PET inpancreatic cancer. The authors review seven studies (Abstracts #183, #189, #190, #254, #357, #375, #378 presented at the2014 ASCO Gastrointestinal Cancers Symposium and discuss on the role of PET in this disease. As the limitations of theResponse Evaluation Criteria In Solid Tumors (RECIST continue to become evident, FDG-PET may identify changes in themetabolic activity within pancreatic adenocarcinoma, and can provide both diagnostic and prognostic information.

  20. Positron emission tomography scan for predicting clinical outcome of patients with recurrent cervical carcinoma following radiation therapy

    Directory of Open Access Journals (Sweden)

    Daya Nand Sharma

    2012-01-01

    Materials and Methods: Twenty two patients of post irradiated recurrent cervical carcinoma (PIRCC were enrolled in this prospective study. 18-fluorodeoxyglucose (FDG PET imaging was performed in each patient before the salvage therapy. The maximum standardized uptake value (SUVmax and metabolic tumor volume (MTV were measured and correlated with cumulative progression free survival (PFS. Results: Median age of patients was 42 years. Majority of patients had stage III disease at the initial presentation and all 22 patients had received prior definitive RT. The median recurrence free period was 11 months. Salvage therapy consisted of surgical resection or re-irradiation depending upon the various clinical and radiological factors. Median SUVmax was 5.8 (range 1.8-50.6 and median MTV was 43 cm 3 (range 5.8-243. The cumulative PFS for all patients was 20% at 30 months. The one-year PFS was 28% for patients with SUVmax value of >5.8 versus 42% for those with SUVmax value of 43 cm 3 versus 45% for those with MTV value of <43 cm 3 (P value 0.8. Conclusion: Our preliminary experience has suggested that FDG uptake on PET scan can predict the clinical outcome of PIRCC patients. Further randomized studies may be conducted with large sample size and longer follow up to establish its definite predictive value.

  1. Clinical value of {sup 18}F-fluorodihydroxyphenylalanine positron emission tomography/computed tomography ({sup 18}F-DOPA PET/CT) for detecting pheochromocytoma

    Energy Technology Data Exchange (ETDEWEB)

    Luster, Markus; Zeich, Katrin; Glatting, Gerhard; Buck, Andreas K.; Solbach, Christoph; Reske, Sven N. [University of Ulm, Department of Nuclear Medicine, Ulm (Germany); Karges, Wolfram [RWTH Aachen, Division of Endocrinology and Diabetes, Aachen (Germany); Pauls, Sandra [University of Ulm, Department of Radiology, Ulm (Germany); Verburg, Frederik A. [University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Dralle, Henning [University Halle-Wittenberg, Department of General, Visceral and Vascular Surgery, Halle (Germany); Neumaier, Bernd [University of Ulm, Department of Nuclear Medicine, Ulm (Germany); Max-Planck-Institut fuer Neurologische Forschung, Section for Radiochemistry, Cologne (Germany); Mottaghy, Felix M. [University of Ulm, Department of Nuclear Medicine, Ulm (Germany); RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany)

    2010-03-15

    In detecting pheochromocytoma (PHEO), positron emission tomography (PET) with the radiolabelled amine precursor {sup 18}F-fluorodihydroxyphenylalanine ({sup 18}F-DOPA) offers excellent specificity, while computed tomography (CT) provides high sensitivity and ability to localize lesions; therefore, the combination of these modalities could be advantageous in this setting. The aim of this study was to investigate whether combined {sup 18}F-DOPA PET/CT more accurately detects and localizes PHEO lesions than does each modality alone. {sup 18}F-DOPA PET, CT and {sup 18}F-DOPA PET/CT images of 25 consecutive patients undergoing diagnostic scanning of suspected sporadic or multiple endocrine neoplasia type 2 syndrome-associated PHEO were reviewed retrospectively in randomized sequence. Two blinded observers scored the images regarding the likelihood of PHEO being present and localizable. Results were correlated with subsequent clinical history and, when available, histology. Of the 19 lesions detected by all three modalities, PET identified each as positive for PHEO, but was unable to definitively localize 15 of 19 (79%). CT could definitively localize all 19 lesions, but could not definitively diagnose or exclude PHEO in 18 of 19 (95%) lesions. Furthermore, CT falsely identified as negative for PHEO one lesion which was judged to be positive for this tumor by both PET and PET/CT. Only in PET/CT scans were all 19 lesions accurately characterized and localized. On a per-patient basis, the sensitivity of {sup 18}F-DOPA PET/CT for PHEO was 100% and the specificity 88%, with a 100% positive predictive value and an 88% negative predictive value. {sup 18}F-DOPA PET/CT more accurately diagnoses and localizes adrenal and extra-adrenal masses suspicious for PHEO than do {sup 18}F-DOPA PET or CT alone. (orig.)

  2. [F-18]Fluorodeoxyglucose positron emission tomography can predict pathological tumor stage and proliferative activity determined by Ki-67 in clinical stage IA lung adenocarcinomas

    International Nuclear Information System (INIS)

    The objective of this study was to predict a malignant grade of lung cancer by fluorodeoxyglucose positron emission tomography (FDG-PET) scanning, we investigated the correlation between FDG uptake and pathological tumor stage, proliferative activities determined by Ki-67 and cyclin D1, and an alteration of p53, in clinical stage (c-stage) IA lung adenocarcinomas. FDG-PET was performed for 71 patients with c-stage IA lung adenocarcinomas. FDG uptake was measured by a contrast ratio (CR) between the tumor and contralateral lung. Ki-67, cyclin D1 and p53 staining scores were examined by immunohistochemistry. The lesions with ground-glass opacity were found in 26 patients, and solid lesions in 45 by computed tomography. The pathological tumor stages (p-stage) were stage IA in 59 and more advanced stages in 12. The latter had significantly higher CR value than the former (P<0.001). Patients with CR≥0.55 could be predicted to be at advanced tumor stages, with a sensitivity of 0.83 and a specificity of 0.82. The CR and staining scores of Ki-67 were significantly correlated with each other (P<0.0001), and both the values were significantly higher in advanced tumor stages than in p-stage IA, and were also significantly higher in tumors with intratumoral lymphatic, vascular and pleural involvements than in those without such features (P<0.05-0.0001). In c-stage IA lung adenocarcinomas, the FDG uptake can predict p-stage and tumor proliferative activity determined by Ki-67. For c-stage IA lung adenocarcinomas showing CR≥0.55, mediastinoscopy or neoadjuvant chemotherapy is indicated. (author)

  3. ROC [Receiver Operating Characteristics] study of maximum likelihood estimator human brain image reconstructions in PET [Positron Emission Tomography] clinical practice

    International Nuclear Information System (INIS)

    This paper will report on the progress to date in carrying out Receiver Operating Characteristics (ROC) studies comparing Maximum Likelihood Estimator (MLE) and Filtered Backprojection (FBP) reconstructions of normal and abnormal human brain PET data in a clinical setting. A previous statistical study of reconstructions of the Hoffman brain phantom with real data indicated that the pixel-to-pixel standard deviation in feasible MLE images is approximately proportional to the square root of the number of counts in a region, as opposed to a standard deviation which is high and largely independent of the number of counts in FBP. A preliminary ROC study carried out with 10 non-medical observers performing a relatively simple detectability task indicates that, for the majority of observers, lower standard deviation translates itself into a statistically significant detectability advantage in MLE reconstructions. The initial results of ongoing tests with four experienced neurologists/nuclear medicine physicians are presented. Normal cases of 18F -- fluorodeoxyglucose (FDG) cerebral metabolism studies and abnormal cases in which a variety of lesions have been introduced into normal data sets have been evaluated. We report on the results of reading the reconstructions of 90 data sets, each corresponding to a single brain slice. It has become apparent that the design of the study based on reading single brain slices is too insensitive and we propose a variation based on reading three consecutive slices at a time, rating only the center slice. 9 refs., 2 figs., 1 tab

  4. 18F-Fluorodeoxyglucose Positron Emission Tomography for Primary Thyroid Cancer: Correlation with the Clinical, Pathologic and Sonographic Findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Eun; Kim, Eun Kyung; Moon, Hee Jung; Kwak, Jin Young [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2011-06-15

    We wanted to investigate the incidence and the clinicopathologic and sonographic characteristics of thyroid cancers that exhibit positive PET scans. From January 2007 to February 2008, 156 patients with thyroid cancer underwent both sonography and FDG-PET for the purpose of staging the cancer. We conducted a retrospective review of their clinical, radiologic and pathologic records and we evaluated the incidence of PET-positive thyroid cancer, as well as the associated clinicopathologic aggressiveness and the sonographic features. The incidence of PET-positive thyroid carcinoma was 78.2% (122/156). On univariate analysis, PET-positive thyroid cancer was significantly associated with tumor size, extracapsular invasion and central lymph node metastasis, but there was no association between the sonographic features of the thyroid cancer or the sonographic features of the 2 groups of tumor (1. probably benign and 2. suspicious for malignancy) and the FDG uptake. Multivariate logistic regression analysis showed a significant association between PET positivity and both extrathyroidal extension and a higher cancer stage (III/IV) (p < 0.05). The incidence of PET positive thyroid carcinoma is high (78.2%) and PET positivity is significantly associated with tumor size, extracapsular extension and a higher stage. However, there is no significant association between PET positivity and the sonographic features of thyroid carcinoma

  5. ROC (Receiver Operating Characteristics) study of maximum likelihood estimator human brain image reconstructions in PET (Positron Emission Tomography) clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Llacer, J.; Veklerov, E.; Nolan, D. (Lawrence Berkeley Lab., CA (USA)); Grafton, S.T.; Mazziotta, J.C.; Hawkins, R.A.; Hoh, C.K.; Hoffman, E.J. (California Univ., Los Angeles, CA (USA))

    1990-10-01

    This paper will report on the progress to date in carrying out Receiver Operating Characteristics (ROC) studies comparing Maximum Likelihood Estimator (MLE) and Filtered Backprojection (FBP) reconstructions of normal and abnormal human brain PET data in a clinical setting. A previous statistical study of reconstructions of the Hoffman brain phantom with real data indicated that the pixel-to-pixel standard deviation in feasible MLE images is approximately proportional to the square root of the number of counts in a region, as opposed to a standard deviation which is high and largely independent of the number of counts in FBP. A preliminary ROC study carried out with 10 non-medical observers performing a relatively simple detectability task indicates that, for the majority of observers, lower standard deviation translates itself into a statistically significant detectability advantage in MLE reconstructions. The initial results of ongoing tests with four experienced neurologists/nuclear medicine physicians are presented. Normal cases of {sup 18}F -- fluorodeoxyglucose (FDG) cerebral metabolism studies and abnormal cases in which a variety of lesions have been introduced into normal data sets have been evaluated. We report on the results of reading the reconstructions of 90 data sets, each corresponding to a single brain slice. It has become apparent that the design of the study based on reading single brain slices is too insensitive and we propose a variation based on reading three consecutive slices at a time, rating only the center slice. 9 refs., 2 figs., 1 tab.

  6. Quantification of myocardial blood flow with {sup 82}Rb positron emission tomography: clinical validation with {sup 15}O-water

    Energy Technology Data Exchange (ETDEWEB)

    Prior, John O.; Allenbach, Gilles; Bischof Delaloye, Angelika [Centre Hospitalier Universitaire Vaudois and University of Lausanne, Nuclear Medicine Department, Lausanne (Switzerland); Valenta, Ines; Burger, Cyrill [Cardiac Imaging, Department of Radiology, Zurich (Switzerland); Kosinski, Marek [Centre Hospitalier Universitaire Vaudois and University of Lausanne, Nuclear Medicine Department, Lausanne (Switzerland); Centre Hospitalier Universitaire Vaudois and University of Lausanne, University Institute for Radiation Physics, Lausanne (Switzerland); Verdun, Francis R. [Centre Hospitalier Universitaire Vaudois and University of Lausanne, University Institute for Radiation Physics, Lausanne (Switzerland); Kaufmann, Philipp A. [Cardiac Imaging, Department of Radiology, Zurich (Switzerland); University of Zurich, Zurich Centre for Integrative Human Physiology (ZIHP), Zurich (Switzerland)

    2012-06-15

    coronary artery territories (p > 0.31). Quantification of MBF with {sup 82}Rb with a newly derived correction for the nonlinear extraction function was validated against MBF measured using {sup 15}O-water in control subjects and patients with mild CAD, where it was found to be accurate at high flow rates. {sup 82}Rb-derived MBF estimates seem robust for clinical research, advancing a step further towards its implementation in clinical routine. (orig.)

  7. 18F-Fluorodeoxyglucose positron emission tomography pulmonary imaging in idiopathic pulmonary fibrosis is reproducible: implications for future clinical trials

    International Nuclear Information System (INIS)

    Noninvasive markers of disease activity in patients with idiopathic pulmonary fibrosis (IPF) are lacking. We performed this study to investigate the reproducibility of pulmonary 18F-FDG PET/CT in patients with IPF. The study group comprised 13 patients (11 men, 2 women; mean age 71.1 ± 9.9 years) with IPF recruited for two thoracic 18F-FDG PET/CT studies performed within 2 weeks of each other. All patients were diagnosed with IPF in consensus at multidisciplinary meetings as a result of typical clinical, high-resolution CT and pulmonary function test features. Three methods for evaluating pulmonary 18F-FDG uptake were used. The maximal 18F-FDG pulmonary uptake (SUVmax) in the lungs was determined using manual region-of-interest placement. An 18F-FDG uptake intensity histogram was automatically constructed from segmented lungs to evaluate the distribution of SUVs. Finally, mean SUV was determined for volumes-of-interest in pulmonary regions with interstitial lung changes identified on CT scans. Processing included correction for tissue fraction effects. Bland-Altman analysis was performed and interclass correlation coefficients (ICC) were determined to assess the reproducibility between the first and second PET scans, as well as the level of intraobserver and interobserver agreement. The mean time between the two scans was 6.3 ± 4.3 days. The interscan ICCs for pulmonary SUVmax analysis and mean SUV corrected for tissue fraction effects were 0.90 and 0.91, respectively. Intensity histograms were different in only 1 of the 13 paired studies. Intraobserver agreement was also excellent (0.80 and 0.85, respectively). Some bias was observed between observers, suggesting that serial studies would benefit from analysis by the same observer. This study demonstrated that there is excellent short-term reproducibility in pulmonary 18F-FDG uptake in patients with IPF. (orig.)

  8. Diagnosis of pancreatic cancer using fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET). Usefulness and limitations in clinical reality''

    International Nuclear Information System (INIS)

    The present review will provide an overview of the literature concerning the FDG PET diagnosis of pancreatic cancer and a summary from our experience of 231 cases of pancreatic lesions. FDG PET can effectively differentiate pancreatic cancer from benign lesion with high accuracy. Newly-developed PET scanners can detect small pancreatic cancers, up to 7 mm in diameter, by their high resolution, which could make a great contribution to the early detection of resectable and potentially curable pancreatic cancers. FDG PET is useful and cost-beneficial in the pre-operative staging of pancreatic cancer because an unexpected distant metastasis can be detected by whole-body PET in about 40% of the cases, which results in avoidance of unnecessary surgical procedures. FDG PET is also useful in evaluation of the treatment effect, monitoring after the operation and detection of recurrent pancreatic cancers. However, there are some drawbacks in PET diagnosis. A relatively wide overlap has been reported between semiquantitative uptake values obtained in cancers and those in inflammatory lesions. As for false-positive cases, active and chronic pancreatitis and autoimmune pancreatitis sometimes show high FDG accumulation and mimic pancreatic cancer with a shape of focal uptake. There were 8 false negative cases in the detection of pancreatic cancer by FDG PET, up to 33 mm in diameter, mainly because of their poor cellularity in cancer tissues. In addition, there are 19% of cancer cases with a decline in FDG uptake from 1 hr to 2 hr scan. FDG PET was recently applied to and was shown to be feasible in the differential diagnosis of cystic pancreatic lesions, such as intraductal papillary mucinous tumor of the pancreas. Further investigations are required to clarify the clinical value of FDG PET in predicting prognosis of the pancreatic patients. (author) 124 refs

  9. Positron emission tomography tracers for imaging angiogenesis

    International Nuclear Information System (INIS)

    Position emission tomography imaging of angiogenesis may provide non-invasive insights into the corresponding molecular processes and may be applied for individualized treatment planning of antiangiogenic therapies. At the moment, most strategies are focusing on the development of radiolabelled proteins and antibody formats targeting VEGF and its receptor or the ED-B domain of a fibronectin isoform as well as radiolabelled matrix metalloproteinase inhibitors or αvβ3 integrin antagonists. Great efforts are being made to develop suitable tracers for different target structures. All of the major strategies focusing on the development of radiolabelled compounds for use with positron emission tomography are summarized in this review. However, because the most intensive work is concentrated on the development of radiolabelled RGD peptides for imaging αvβ3 expression, which has successfully made its way from bench to bedside, these developments are especially emphasized. (orig.)

  10. Preclinical and the first clinical studies on [11C]ITMM for mapping metabotropic glutamate receptor subtype 1 by positron emission tomography

    International Nuclear Information System (INIS)

    Introduction: Preclinical studies and first positron emission tomography (PET) imaging studies were performed using N-[4-[6-(isopropylamino)pyrimidin-4-yl]-1,3-thiazol-2-yl]-4-[11C] methoxy-N-methylbenzamide ([11C]ITMM) to map metabotropic glutamate receptor type 1 (mGluR1) in the human brain. Methods: [11C]ITMM was synthesized by O-methylation of the desmethyl precursor with [11C]methyl triflate in the presence of NaOH at room temperature. In vitro selectivity and brain distributions of [11C]ITMM in mice were characterized. Radiation absorbed-dose by [11C]ITMM in humans was calculated from mouse distribution data. Acute toxicity of ITMM at 4.72 mg/kg body weight (> 74,000-fold clinical equivalent dose of [11C]ITMM) was evaluated. Mutagenicity of ITMM was studied by the Ames test. Clinical PET imaging of mGluR1 with [11C] ITMM was performed in a healthy volunteer. Results: ITMM had low activity for a 28-standard receptor binding profile. Regional brain uptake of [11C]ITMM in mice was heterogeneous and consistent with known mGluR1 distributions. The radiation absorbed-dose by [11C]ITMM in humans was sufficiently low for clinical use, and no acute toxicity or mutagenicity of ITMM occurred. A 90-min dynamic PET scan with [11C]ITMM in a healthy volunteer showed a gradual increase of radioactivity in the cerebellum. Total distribution volume of [11C]ITMM was highest in the cerebellum, followed by thalamus, cerebral cortex, and striatum; regional differences in brain radioactivity corresponded to the mGluR1 distribution in the brain. Peripherally, [11C]ITMM was stable in humans: 60% of the plasma radioactivity remained in the unchanged form for 60 min. Conclusions: [11C] ITMM is a suitable radioligand for imaging mGluR1 in the human brain providing acceptable dosimetry and pharmacological safety at the dose required for PET

  11. [Basic principles of 18F-fluorodeoxyglucose positron emission tomography].

    Science.gov (United States)

    Standke, R

    2002-01-01

    Positron emission tomography uses photons to receive regional information about dynamic, physiologic, and biochemical processes in the living body. A positron decay is measured indirectly by the simultaneous registration of both gamma rays created by the annihilation. The event is counted, if two directly opposite located detectors register gamma rays in coincidence. Unfortunately the detectors of a positron emission tomography system do not register only true coincident events. There are also scattered and random coincidences. Different types of positron tomographs are presented and scintillation crystals, which are in use for positron emission tomography are discussed. The 2D- and 3D-acquisition methods are described as well as preprocessing methods, such as correction for attenuation, scatter and dead time. For quantification the relative parameter standard uptake value (SUV) is explained. Finally hybrid systems, such as combined positron emission tomography/computed tomography scanners and the use of computed tomography data for attenuation correction are introduced. PMID:12506765

  12. 77 FR 8262 - Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    Science.gov (United States)

    2012-02-14

    ... Positron Emission Tomography Drugs; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice... entitled ``Investigational New Drug Applications for Positron Emission Tomography (PET) Drugs.'' The draft... Applications for Positron Emission Tomography (PET) drugs.'' The draft guidance summarizes the IND process...

  13. Pulmonary studies using positron emission tomography

    International Nuclear Information System (INIS)

    The detailed investigation of regional differences in lung function at a local level began when suitable γ-ray emitting isotopes and focused external radiation detectors (especially the Anger γ-camera) became available. A major recent advance has been the development of positron emission tomography (PET), which provides a powerful combination of highly accurate tomographic reconstruction of radioisotope concentration with a potentially unlimited list of biological compounds to be labelled with the positron emitting isotopes of oxygen, carbon and fluorine. Early studies using PET focused on the inhalation of 11CO (or C15O) and 19Ne gases and the intravenous injection of 13N in saline and H215O for the measurement of relatively simple aspects of regional lung function, such as tissue, blood and gas volumes, blood flow, ventilation and ventilation/perfusion (V'A/Q'). More recent work has been directed towards the more challenging areas of regional endothelial permeability, carbohydrate utilization, enzyme and receptor binding assays, and in vivo pharmacokinetics. The short physical half-lives of the isotopes (17 s to 2 h) and the noninvasive nature of PET allows serial measurements to be made on patients (within the constraints of permitted radiation doses) to assess the effect of physiological and therapeutic interventions. (au) 80 refs

  14. Positron emission tomography: diagnostic imaging on a molecular level

    International Nuclear Information System (INIS)

    In human medicine positron emission tomography (PET) is a modern diagnostic imaging method. In the present paper we outline the physical principles of PET and give an overview over the main clinic fields where PET is being used, such as neurology, cardiology and oncology. Moreover, we present a current project in veterinary medicine (in collaboration with the Paul Scherrer Institute and the University Hospital Zurich), where a hypoxia tracer is applied to dogs and cats suffering from spontaneous tumors. Finally new developments in the field of PET were discussed

  15. Positron emission tomography in urological cancer

    International Nuclear Information System (INIS)

    In staging cancer of the urinary bladder, the kidneys and the prostate and of testicular cancer there is a need for detecting tumor involvement of the lymph nodes to avoid surgical exploration. Positron emission tomography (PET) using fluorodeoxyglucose (FDG) can detect tumorous lymph nodes (sensitivity: 70%, specificity: 85%) which is helpful for several patients. In carcinoma of the prostate, other radiotracers than FDG (e.g. C-11-choline) might be more sensitive to detect tumorous lymph nodes. Up to now no diagnostical benefit of PET in germ cell tumors could be demonstrated in the published small series. In principle FDG-PET is useful in diagnosis of recurrence. In germ cell cancer FDG-PET seems to identify effectively persistent vital tumor tissue after chemotherapy. A multicenter study was initiated to demonstrate the potential of FDG-PET in a sufficient number of patients with germ cell tumor. (orig.)

  16. Compact conscious animal positron emission tomography scanner

    Science.gov (United States)

    Schyler, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois; Volkow, Nora

    2006-10-24

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

  17. Positron emission tomography of the heart

    International Nuclear Information System (INIS)

    Positron emission computed tomography (PCT) represents an important new tool for the noninvasive evaluation and, more importantly, quantification of myocardial performance. Most currently available techniques permit assessment of only one aspect of cardiac function, i.e., myocardial perfusion by gamma scintillation camera imaging with Thallium-201 or left ventricular function by echocardiography or radionuclide angiocardiography. With PCT it may become possible to study all three major segments of myocardial performance, i.e., regional blood flow, mechanical function and, most importantly, myocardial metabolism. Each of these segments can either be evaluated separately or in combination. This report briefly describes the principles and technological advantages of the imaging device, reviews currently available radioactive tracers and how they can be employed for the assessment of flow, function and metabolism; and, lastly, discusses possible applications of PCT for the study of cardiac physiology or its potential role in the diagnosis of cardiac disease

  18. Positron emission tomography and basal ganglia functions

    International Nuclear Information System (INIS)

    With the advent of positron emission tomography (PET), studies on the human brain function and pathophysiology of brain damage have been extremely progressed. It is well-known that the basal ganglia plays an important role as one of the central nervous system involved in exercise regulation. More recently, the potential involvement of the basal ganglia in psychological processes, such as cognitive function, has been pointed out, receiving much attention. In spite of such a lot of studies, however, basal ganglia function remains unclear. This paper describes the relationships between PET findings and basal ganglia function. PET findings are discussed in relation to brain energy metabolism and striatal dopamine function. Pathophysiology of the basal ganglia are described in terms of the following diseases: Parkinson's disease, Parkinson's syndrome, progressive supranuclear palsy, Huntington's disease, and dystonia. Physiological backgrounds of the basal ganglia for PET images are also referred to. (N.K.) 75 refs

  19. Positron emission tomography of the heart

    Energy Technology Data Exchange (ETDEWEB)

    Schelbert, H.R.; Phelps, M.E.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography (PCT) represents an important new tool for the noninvasive evaluation and, more importantly, quantification of myocardial performance. Most currently available techniques permit assessment of only one aspect of cardiac function, i.e., myocardial perfusion by gamma scintillation camera imaging with Thallium-201 or left ventricular function by echocardiography or radionuclide angiocardiography. With PCT it may become possible to study all three major segments of myocardial performance, i.e., regional blood flow, mechanical function and, most importantly, myocardial metabolism. Each of these segments can either be evaluated separately or in combination. This report briefly describes the principles and technological advantages of the imaging device, reviews currently available radioactive tracers and how they can be employed for the assessment of flow, function and metabolism; and, lastly, discusses possible applications of PCT for the study of cardiac physiology or its potential role in the diagnosis of cardiac disease.

  20. Clinical implications of determination of safe surgical margins by using a combination of CT and 18FDG-positron emission tomography in soft tissue sarcoma

    Directory of Open Access Journals (Sweden)

    Yoshioka Takako

    2011-07-01

    Full Text Available Abstract Background To determine safe surgical margins for soft tissue sarcoma, it is essential to perform a general evaluation of the extent of tumor, responses to auxiliary therapy, and other factors preoperatively using multiple types of diagnostic imaging. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT is a tool for diagnostic imaging that has recently spread rapidly in clinical use. At present, the roles played by FDG-PET/CT in determination of margins for surgical resection of sarcoma are unclear. The present study was undertaken to explore the roles of FDG-PET/CT in determination of surgical margins for soft tissue sarcoma and to examine whether PET can serve as a standard means for setting the margins of surgical resection during reduced surgery. Methods The study involved 7 patients with sarcoma who underwent surgery in our department and in whom evaluation with FDG-PET/CT was possible. Sarcoma was histologically rated as MFH in 6 cases and leiomyosarcoma in 1 case. In all cases, sarcoma was superficial (T1a or T2a. The tumor border was defined by contrast-enhanced MRI, and SUVs were measured at intervals of 1 cm over a 5-cm long area from the tumor border. Mapping of viable tumor cells was carried out on whole-mount sections of resected tissue, and SUVs were compared with histopathological findings. Results Preoperative maximum SUVs (SUV-max of the tumor averaged 11.7 (range: 3.8-22.1. Mean SUV-max was 2.2 (range: 0.3-3.8 at 1 cm from the tumor border, 1.1 (0.85-1.47 at 2 cm, 0.83 (0.65-1.15 at 3 cm, 0.7 (0.42-0.95 at 4 cm, and 0.64 (0.45-0.82 at 5 cm. When resected tissue was mapped, tumor cells were absent in the areas where SUV-max was below 1.0. Conclusions Our findings suggest that a safe surgical margin free of viable tumor cells can be ensured if the SUV cut-off level is set at 1.0. FDG-PET/CT is promising as a diagnostic imaging technique for setting of safe minimal margins for surgical

  1. Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and PET/Computed Tomography Imaging Characteristics of Thyroid Lymphoma and Their Potential Clinical Utility

    Energy Technology Data Exchange (ETDEWEB)

    Basu, S.; Li, G.; Bural, G.; Alavi, A. (Div. of Nuclear Medicine, Hospital of Univ. of Pennsylvania, Philadelphia, PA (United States))

    2009-02-15

    Background: A relative paucity of data exists in the literature with regard to the utility of fluorodeoxyglucose positron emission tomography (FDG-PET) imaging in the clinical management of patients with primary lymphoma of the thyroid gland (PTL). Purpose: To explore the FDG-PET imaging characteristics and their potential role in PTL, and to compare the results with anatomical imaging modalities. Material and Methods: Patients with thyroid lymphoma who had undergone whole-body FDG-PET or PET/computed tomography (CT) during their course of the disease were identified by examination of case records. PET scans were reevaluated, and maximum standardized uptake value (SUVmax) was calculated and used as the semiquantitative measure of FDG uptake for this analysis. CT and/or magnetic resonance imaging (MRI) studies carried out within 1 week of FDG-PET scan and without any therapeutic intervention between the two studies were considered for the purpose of comparison. A total of six patients with 20 studies (14 FDG-PET and six PET/CT examinations) were identified following the criteria. All patients were female (age 16-83 years). Among these, five were proven to have PTL. Two patients had localized PTL (stage IE), two patients had associated regional nodal involvement (IIE), and one patient had associated nodal involvement on both sides of the diaphragm (IIIE) at presentation. Except for one patient with follicular B-cell lymphoma, all others were diffuse large-B-cell lymphoma (DLBCL) subtype. Results: Avid FDG uptake was observed in both cases of untreated PTL, with SUVmax of 23 and 7.6, respectively. One patient showed focal FDG uptake (SUVmax 6.7) in the thyroid in the setting of a responding abdominal non-Hodgkin lymphoma (NHL) and was subsequently proven as adenomatous nodule with Hurthle cell changes. Following successful therapy, SUVmax declined consistently with improvement in disease status. In one patient, complete response was noted earlier by FDG-PET compared

  2. Non-oncological positron emission tomography (PET): brain imaging

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) allows evaluation of the central nervous system function. Imaging of regional cerebral blood flow and metabolism, and of several neurotransmission systems may be obtained using PET. PET quantification is accurate and has good test-retest reliability. For research purposes, PET has been used to study brain physiology, to explore neurological and psychiatric diseases pathophysiology and for the new drugs research and development. F.D.G. is the only PET radioligand with clinical application. Following criteria of evidence-based medicine, the clinical indications of F.D.G.-PET are: evaluation of treated gliomas, pre surgical study of partial refractory epilepsy and diagnosis of Alzheimer's disease when it is impossible to differentiate clinically from fronto-temporal dementia

  3. Positron emission tomography: physics, instrumentation, and image analysis.

    Science.gov (United States)

    Porenta, G

    1994-01-01

    Positron emission tomography (PET) is a noninvasive diagnostic technique that permits reconstruction of cross-sectional images of the human body which depict the biodistribution of PET tracer substances. A large variety of physiological PET tracers, mostly based on isotopes of carbon, nitrogen, oxygen, and fluorine is available and allows the in vivo investigation of organ perfusion, metabolic pathways and biomolecular processes in normal and diseased states. PET cameras utilize the physical characteristics of positron decay to derive quantitative measurements of tracer concentrations, a capability that has so far been elusive for conventional SPECT (single photon emission computed tomography) imaging techniques. Due to the short half lives of most PET isotopes, an on-site cyclotron and a radiochemistry unit are necessary to provide an adequate supply of PET tracers. While operating a PET center in the past was a complex procedure restricted to few academic centers with ample resources, PET technology has rapidly advanced in recent years and has entered the commercial nuclear medicine market. To date, the availability of compact cyclotrons with remote computer control, automated synthesis units for PET radiochemistry, high-performance PET cameras, and user-friendly analysis workstations permits installation of a clinical PET center within most nuclear medicine facilities. This review provides simple descriptions of important aspects concerning physics, instrumentation, and image analysis in PET imaging which should be understood by medical personnel involved in the clinical operation of a PET imaging center. PMID:7941595

  4. Positron emission tomography: Physics, instrumentation, and image analysis

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a noninvasive diagnostic technique that permits reconstruction of cross-sectional images of the human body which depict the biodistribution of PET tracer substances. A large variety of physiological PET tracers, mostly based on isotopes of carbon, nitrogen, oxygen, and fluorine is available and allows the in vivo investigation of organ perfusion, metabolic pathways and biomolecular processes in normal and diseased states. PET cameras utilize the physical characteristics of positron decay to derive quantitative measurements of tracer concentrations, a capability that has so far been elusive for conventional SPECT (single photon emission computed tomography) imaging techniques. Due to the short half lives of most PET isotopes, an on-site cyclotron and a radiochemistry unit are necessary to provide an adequate supply of PET tracers. While operating a PET center in the past was a complex procedure restricted to few academic centers with ample resources. PET technology has rapidly advanced in recent years and has entered the commercial nuclear medicine market. To date, the availability of compact cyclotrons with remote computer control, automated synthesis units for PET radiochemistry, high-performance PET cameras, and userfriendly analysis workstations permits installation of a clinical PET center within most nuclear medicine facilities. This review provides simple descriptions of important aspects concerning physics, instrumentation, and image analysis in PET imaging which should be understood by medical personnel involved in the clinical operation of a PET imaging center. (author)

  5. Incidental detection of clinically occult follicle stimulating hormone secreting pituitary adenoma on whole body 18-fluorodeoxyglucose positron emission tomography-computed tomography

    International Nuclear Information System (INIS)

    A 73-year-old man, known case of Hodgkin's lymphoma, underwent 18-Fluorodeoxyglucose positron emission tomography-computed tomography (18-FDG PET-CT) for post-chemotherapy evaluation of the disease status. The scan revealed focal increased FDG uptake in pituitary fossa. The CT images showed homogeneously enhancing pituitary lesion causing expansion of the sella. A possibility for the presence of pituitary adenoma was raised in the report. Hormonal assay of the patient showed raised follicle stimulating hormone (FSH) level of 18 IU/ml (normal range for males up to 5 IU/ml). All the other pituitary hormones were within the normal range. Nuclear magnetic resonance (NMR) imaging of brain showed a pituitary lesion with expanded sella pushing the optic chiasma superiorly. NMR findings confirmed the presence of pituitary macroadenoma. A final diagnosis of FSH secreting pituitary macroadenoma was made. (author)

  6. Experience on clinical application of positron emission tomography with a new radiopharmaceutical preparation Sodium 11C-butyrate in differential diagnosis of pathological volume brain formation

    International Nuclear Information System (INIS)

    Possibilities of the application of new radiopharmaceutical - sodium butyrate, [1-11C] (11C-Butyrate) for differential diagnosis of pathological volume brain formation were studied. Positron emission tomography (PET) of the brain was performed in 24 patients. In addition PET with 18F-FDG was performed in all patients. In 15 out of 24 patients the brain malignant tumor has been discovered, in 4 patients - benign tumors, in 5 - postoperative cysts. Results of the studies showed that the ratio tumor/normal tissue in case of 11C-Butyrate and 18F-FDG application proved to be comparable for all studied histological types of tumors. Malignant tumors in these cases had been visualized as a hot spots of increased uptake 11C-Butyrate (ratio ≥ 1). The obtained data testify to the diagnosis of the pathological volume brain formation

  7. Recent developments in positron emission tomography (PET) instrumentation

    International Nuclear Information System (INIS)

    This paper presents recent detector developments and perspectives for positron emission tomography (PET) instrumentation used for medical research, as well as the physical processes in positron annihilation, photon scattering and detection, tomograph design considerations, and the potentials for new advances in detectors. 117 refs., 4 figs., 4 tabs

  8. Clinical usefulness of positron emission tomography in the evaluation of regional cerebral blood flow and cerebral oxygen metabolism under glycerol and carbon dioxide loadings

    Energy Technology Data Exchange (ETDEWEB)

    Tanada, Shuji; Yonekura, Yoshiharu; Senda, Michio

    1987-02-01

    Cerebral blood flow (CBF) and oxygen metabolism (CMRO/sub 2/) were studied in normal cerebral cortices by positron emission tomography using continuous inhalation method of oxygen-15 labeled carbon dioxide and oxygen, and single inhalation method of oxygen-15 labeled carbon monoxide. The values of CBF, CMRO/sub 2/, and oxygen extraction fraction (OEF) in cerebral cortices of 18 healthy normal volunteers represented 40 +- 7 ml/100 ml/min, 3.2 +- 0.5 ml O/sub 2//100 ml/min, and 0.43 +- 0.07, respectively. In cases with glycerol loading, CBF increased in 10/14 cases. Studies of 6 cases with intracranial pressure indicated the presence of mechanism by which depressed CMRO/sub 2/ improved and was kept in normal values. The loading of 5% carbon dioxide showed an increase in CBF in cases with cerebral infarction, which implied the good cerebral vascular response to the elevated arterial carbon dioxide, but no particular changes were observed in CMRO/sub 2/ which seemed to be less responsive to the elevated arterial carbon dioxide level. In cases with moyamoya disease, 5% carbon dioxide loading showed no changes in CBF and CMRO/sub 2/. This suggested the poor cerebral vascular response to the elevation of arterial carbon dioxide, while X-ray CT failed to demonstrate any abnormalities in corresponding areas. Positron emission tomography proved to have a great potentiality regarding the evaluation of the changes in cerebral blood flow and cerebral oxygen metabolism under various loadings.

  9. Simulation of the annihilation emission of galactic positrons

    International Nuclear Information System (INIS)

    Positrons annihilate in the central region of our Galaxy. This has been known since the detection of a strong emission line centered on an energy of 511 keV in the direction of the Galactic center. This gamma-ray line is emitted during the annihilation of positrons with electrons from the interstellar medium. The spectrometer SPI, onboard the INTEGRAL observatory, performed spatial and spectral analyses of the positron annihilation emission. This thesis presents a study of the Galactic positron annihilation emission based on models of the different interactions undergone by positrons in the interstellar medium. The models are relied on our present knowledge of the properties of the interstellar medium in the Galactic bulge, where most of the positrons annihilate, and of the physics of positrons (production, propagation and annihilation processes). In order to obtain constraints on the positrons sources and physical characteristics of the annihilation medium, we compared the results of the models to measurements provided by the SPI spectrometer. (author)

  10. Amorphous silicon detectors in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Conti, M. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy) Lawrence Berkeley Lab., CA (USA)); Perez-Mendez, V. (Lawrence Berkeley Lab., CA (USA))

    1989-12-01

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs.

  11. Physiologic signal detection in positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography enables the noninvasive quantification in vivo of three-dimensional radionuclide distributions throughout the human body. Estimation of neurotransmitter and receptor function is performed through the application of tracer kinetic models and non-linear multiple regression parameter estimation methods. These quantitative estimates are often limited by the interaction between imaging characteristics of the PET scanner and the three-dimensional radionuclide distribution within the organ of interest. In order to assess the potential of PET to detect subtle changes in the function of the central nervous system, a three-dimensional PET simulation procedure based upon a digital brain phantom and tomograph detector response functions has been performed. Radiopharmaceutical kinetics for individual structures of the brain phantom (cortex, white matter, basal ganglia, etc.) have been assigned based upon in vitro autoradiography of human postmortem tissue and animal biodistribution studies. The recovery of the PET signals which originate from anatomic structures of interest has been evaluated for studies of the benzodiazepine, muscarinic, opiate, and GABA systems of the human brain. Typical results and the limitations of signal detection in PET neurotransmitter and receptor studies are discussed

  12. Amorphous silicon detectors in positron emission tomography

    International Nuclear Information System (INIS)

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters ε2τ's are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs

  13. Myocardial energy metabolism by positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) permits quantitative measurement of myocardial blood flow and metabolism in vivo in the cardiovascular areas. F-18 fluorodeoxyglucose (FDG) and C-11 palmitate have been used for energy metabolism in the cardiac PET. In fasting condition, beta-oxydation of fatty acids is the major energy source in the normal myocardium, whereas glucose metabolism is enhanced in the ischemic myocardium. No metabolic substrate is used in the necrotic myocardium. Thus, quantitative measurement of substrate utilization enables differentiation of ischemic from normal or infarcted myocardium and precise assessment of tissue abnormalities in vivo. FDG is administrated in fasting condition in our institute in order to delineate ischemic myocardium as a hot spot with suppression of the FDG uptake in the normal myocardium. However, when compared to the postprandial condition, FDG uptake may be enhanced even in the infarcted tissue, and thus, may possibly overestimate the tissue viability. A certain quantification of FDG uptake may be warranted for an accurate evaluation of FDG uptake. We have been measured FDG uptake index as a fraction of injected dose (% dose/100g tissue). This index correlated well with myocardial metabolic rate of glucose by Phelps method in the fasting condition. Dynamic PET study after C-11 palmitate injection has been used for estimate of fatty acid utilization. The first component of the washout from the myocardium is considered as rate of beta-oxydation. However, the washout of this tracer seems to be strikingly different between the fasting and postprandial conditions. (J.P.N.)

  14. Patient radiation protection in positron emission tomography

    International Nuclear Information System (INIS)

    Patient radiation protection in Positron Emission Tomography (PET) is closely related to the correct execution of studies: proper scanner performance, and optimization of both image quality and patient dose. We describe the quality control tests considered as essential: scanner stability, spatial resolution, sensitivity and tomographic uniformity. Knowledge of the dose received by the critical organ and the effective dose for each radiopharmaceutical allows the establishment of strategies for dose optimization. Although a great variety of PET tracers exist, we review the dose produced by F-FDG, the most widely used tracer, and those used in our PET Center O-Water, N-Ammonia, C-Methionine, C-Choline, F-Choline, F-Dopa, and F-FHBG. Reduction of administered activity to the patient is the direct way to reduce the dose. Thus, PET acquisition in the 3D mode, with higher sensitivity, is a determining factor. In order to reduce the dose to different organs, efforts should be directed to the critical organs, mainly the urinary bladder wall. Finally, correct patient preparation improves, PET image quality, due to an optimum tracer uptake, which optimizes the dose to different organs. (Author) 25 refs

  15. FDG positron emission computed tomography in a study of aphasia

    International Nuclear Information System (INIS)

    Positron emission computed tomography (PECT) using 18F-2-fluoro-2-deoxy-D-glucose (FDG) was used to investigate the correlations between clinical status, anatomy (as described by CT), and metabolism in five patients with stable aphasia resulting from ischemic cerebral infarction. Local cerebral metabolic activity was diminished in an area larger than the area of infarction demonstrated by CT. In one patient, FDG PECT revealed a metabolic lesion that probably caused the aphasic syndrome and was not apparent by CT. The data suggest that reliance on CT in delineating the extent of the brain lesion in aphasia or other neuropsychological defects can be misleading; FDG PECT may provide important additional information. Two patients with similar metabolic lesions had very different clinical syndromes, showing that even when currently available methods are combined, major gaps remain in clinicoanatomical correlations in aphasia

  16. Positron emission tomography with gamma camera in coincidence mode

    International Nuclear Information System (INIS)

    Positron emission tomography using F-18 FDG has been estbalished in clinical diagnostics with first indications especially in oncology. To install a conventional PET tomography (dedicated PET) is financially costly and restricted to PET examinations only. Increasing demand for PET diagnostics on one hand and restricted financial resources in the health system on the other hand led industry to develop SPECT cameras to be operated in coincidence mode (camera PET) in order to offer nuclear medicine physicians cost-effective devices for PET diagnostic. At the same time camera PET is inferior to conventional PET regarding sensitivity and detection-efficiency for 511 keV photons. Does camera-PET offer a reliable alternative to conventional PET? The first larger comparative studies are now available, so a first apraisal about the technical clinical performance of camera-PET can be done. (orig.)

  17. Axial positrons emission tomography: from mouse to human brain imaging

    International Nuclear Information System (INIS)

    Positrons emission tomography is a nuclear imaging technics using nuclear decays. It is used both in clinical and preclinical studies. The later requires the use of small animals such as the mouse. The objective is to obtain the best signal with the best spatial resolution. Yet, a weight ratio between humans and mice indicates the need of a sub-millimeter resolution. A conventional scanner is based on detection modules surrounding the object to image and arranged perpendicularly. This implies a strong relationship between efficiency and spatial resolution. This work focuses on the axial geometry in which detection modules are arranged parallel to the object. This limits the relationship between the figures of merit, leading to both high spatial resolution and efficiency. The simulations of prototypes showed great perspectives in term of sub-millimeter resolution with efficiencies of 15 or 40% according to the scanner's axial extension. These results indicate great perspectives for both clinical and preclinical imaging. (author)

  18. Positron Emission Mammography with Multiple Angle Acquisition

    International Nuclear Information System (INIS)

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FDG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three- dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned

  19. Positron emission tomography/computed tomography.

    Science.gov (United States)

    Townsend, David W

    2008-05-01

    Accurate anatomical localization of functional abnormalities obtained with the use of positron emission tomography (PET) is known to be problematic. Although tracers such as (18)F-fluorodeoxyglucose ((18)F-FDG) visualize certain normal anatomical structures, the spatial resolution is generally inadequate for accurate anatomic localization of pathology. Combining PET with a high-resolution anatomical imaging modality such as computed tomography (CT) can resolve the localization issue as long as the images from the two modalities are accurately coregistered. However, software-based registration techniques have difficulty accounting for differences in patient positioning and involuntary movement of internal organs, often necessitating labor-intensive nonlinear mapping that may not converge to a satisfactory result. Acquiring both CT and PET images in the same scanner obviates the need for software registration and routinely provides accurately aligned images of anatomy and function in a single scan. A CT scanner positioned in line with a PET scanner and with a common patient couch and operating console has provided a practical solution to anatomical and functional image registration. Axial translation of the couch between the 2 modalities enables both CT and PET data to be acquired during a single imaging session. In addition, the CT images can be used to generate essentially noiseless attenuation correction factors for the PET emission data. By minimizing patient movement between the CT and PET scans and accounting for the axial separation of the two modalities, accurately registered anatomical and functional images can be obtained. Since the introduction of the first PET/CT prototype more than 6 years ago, numerous patients with cancer have been scanned on commercial PET/CT devices worldwide. The commercial designs feature multidetector spiral CT and high-performance PET components. Experience has demonstrated an increased level of accuracy and confidence in the

  20. Impact of point spread function correction in standardized uptake value quantitation for positron emission tomography images. A study based on phantom experiments and clinical images

    International Nuclear Information System (INIS)

    While point spread function (PSF)-based positron emission tomography (PET) reconstruction effectively improves the spatial resolution and image quality of PET, it may damage its quantitative properties by producing edge artifacts, or Gibbs artifacts, which appear to cause overestimation of regional radioactivity concentration. In this report, we investigated how edge artifacts produce negative effects on the quantitative properties of PET. Experiments with a National Electrical Manufacturers Association (NEMA) phantom, containing radioactive spheres of a variety of sizes and background filled with cold air or water, or radioactive solutions, showed that profiles modified by edge artifacts were reproducible regardless of background μ values, and the effects of edge artifacts increased with increasing sphere-to-background radioactivity concentration ratio (S/B ratio). Profiles were also affected by edge artifacts in complex fashion in response to variable combinations of sphere sizes and S/B ratios; and central single-peak overestimation up to 50% was occasionally noted in relatively small spheres with high S/B ratios. Effects of edge artifacts were obscured in spheres with low S/B ratios. In patient images with a variety of focal lesions, areas of higher radioactivity accumulation were generally more enhanced by edge artifacts, but the effects were variable depending on the size of and accumulation in the lesion. PET images generated using PSF-based reconstruction are therefore not appropriate for the evaluation of SUV. (author)

  1. Guideline for performance evaluation of positron emission tomographs

    International Nuclear Information System (INIS)

    This supplement presents guideline for performance evaluation of positron emission tomographies (PET). The purpose of this guideline is to define measurement methods for evaluating both the performance of PET equipment and the accuracy of various data corrections in the clinical setting. The guideline has 8 items. The first four items, consisting of spatial dose distributions, scattering fraction, sensitivity, and counting loss and accidental coincidence counting, deals with the basic performance of PET equipment. The next three items, including image uniformity, accuracy of absorption and scattering correction, and characteristics of high counting rate (accuracy of counting loss corrections and S/N ratio), are designed to provide the quantitative evaluation of images reconstructed by various data corrections for absorption, scattering, counting loss, and others. The last item is partial volume effect (recovery coefficient), which is important for the quantitative analysis of PET images, with the aim of both the measurement method of partial volume effect and the definition of phantoms required. (N.K.)

  2. Differential diagnosis of depression: relevance of positron emission tomography

    International Nuclear Information System (INIS)

    The proper differential diagnosis of depression is important. A large body of research supports the division of depressive illness into bipolar and unipolar subtypes with respect to demographics, genetics, treatment response, and neurochemical mechanisms. Optimal treatment is different for unipolar and bipolar depressions. Treating a patient with bipolar depression as one would a unipolar patient may precipitate a serious manic episode or possibly even permanent rapid cycling disorder. The clinical distinction between these disorders, while sometimes difficult, can often be achieved through an increased diagnostic suspicion concerning a personal or family history of mania. Positron emission tomography and the FDG method, which allow in vivo study of the glucose metabolic rates for discrete cerebral structures, provide new evidence that bipolar and unipolar depression are two different disorders

  3. The introduction of positron emission tomography in Australia

    International Nuclear Information System (INIS)

    Positron Emission Tomography (PET) is a relatively new medical imaging modality based on images of the distribution of positron emitting radioisotopes in the human body. A PET scan can non-invasively provide quantitative information on the in vivo function performance of an organ, part thereof, or a bodily process. Two PET centres currently being established in Melbourne and in Sydney are introduced. 18 refs., 1 tab., 5 figs

  4. Recent innovations in the detection systems of Positron Emission Tomography

    International Nuclear Information System (INIS)

    Since the recognition of the clinical value of Positron Emission Tomography (PET) for the diagnosis and staging of several cancers, the PET systems have evolved to systems associating PET and Computed Tomography (CT). The main constraint for clinical imaging is to reduce the acquisition duration. As a consequence, PET detectors are faster and emit more light than the BGO crystal used previously. These detectors allow an improvement of the count rate performance of the PET systems, reducing the scattered and the random events while increasing the true events at high activity concentration. Among the new crystals, some allow measuring the time of flight of the annihilation photons. This measurement further improves the performance of the systems. The spatial resolution of clinical PET systems is still equal to 5 mm at best. High spatial resolution PET systems dedicated to small animal imaging have been developed. These systems use similar crystal materials as the clinical systems. However, in order to permit spatial resolution close to 1 mm, the crystal elements have much smaller transverse dimensions than that of clinical systems. The detectors are compact using position sensitive photomultipliers or photodiodes. In order to preserve the uniformity of the spatial resolution over the transverse field of view of the tomography, solutions allowing the measurement of the depth of interaction of the photons in the crystal have been designed. New compact detectors based on semi conductors are currently investigated. (author)

  5. Human cerebral circulation. Positron emission tomography studies

    International Nuclear Information System (INIS)

    We reviewed the literature on human cerebral circulation and oxygen metabolism, as measured by positron emission tomography (PET), with respect to normal values and of regulation of cerebral circulation. A multicenter study in Japan showed that between-center variations in cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) values were not considerably larger than the corresponding within-center variations. Overall mean±SD values in cerebral cortical regions of normal human subjects were as follows: CBF=44.4±6.5 ml/100 ml/min; CBV=3.8±0.7 ml/100 ml; OEF=0.44±0.06; CMRO2=3.3±0.5 ml/100 ml/min (11 PET centers, 70 subjects). Intrinsic regulation of cerebral circulation involves several factors. Autoregulation maintains CBF in response to changes in cerebral perfusion pressure; chemical factors such as PaCO2 affect cerebral vascular tone and alter CBF; changes in neural activity cause changes in cerebral energy metabolism and CBF; neurogenic control of CBF occurs by sympathetic innervation. Regional differences in vascular response to changes in PaCO2 have been reported, indicating regional differences in cerebral vascular tone. Relations between CBF and CBV during changes in PaCO2 and during changes in neural activity were in good agreement with Poiseuille's law. The mechanisms of vascular response to neural activation and deactivation were independent on those of responses to PaCO2 changes. CBV in a brain region is the sum of three components: arterial, capillary and venous blood volumes. It has been reported that the arterial blood volume fraction is approximately 30% in humans and that changes in human CBV during changes in PaCO2 are caused by changes in arterial blood volume without changes in venous blood volume. These findings should be considered in future studies of the pathophysiology of cerebrovascular diseases. (author) 136 refs

  6. Application of positron emission tomography in neurophysiology

    International Nuclear Information System (INIS)

    PET measures the distribution of positron-emitting radiotracers in the organs of living subjects, by means of the angular correlation of the gamma-rays originating from positron annihilation. The UBC/TRIUMF Program focusses the technique on measurements of brain physiology, and radio-labelled tracers have been developed for measurements of regional cerebral glucose metabolism, regional cerebral blood flow, regional synthesis of dopamine neurotransmitter, and regional density and kinetics of dopamine receptor sites. Data have been obtained on normal physiology, and deranged physiology in Alzheimer's disease, Huntington's disease, Parkinson's disease, and astrocytoma brain tumors undergoing pion radiation treatment

  7. Positron computed tomography: current state, clinical results and future trends

    International Nuclear Information System (INIS)

    An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends

  8. Positron emission tomography with selected mediastinoscopy compared to routine mediastinoscopy offers cost and clinical outcome benefits for pre-operative staging of non-small cell lung cancer

    International Nuclear Information System (INIS)

    18F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is an important staging procedure in patients with non-small cell lung cancer (NSCLC). We aimed to demonstrate, through a decision tree model and the incorporation of real costs of each component, that routine FDG-PET imaging as a prelude to curative surgery will reduce requirements for routine mediastinoscopy and overall hospital costs. A decision tree model comparing routine whole-body FDG-PET imaging to routine staging mediastinoscopy was used, with baseline variables of sensitivity, specificity and prevalence of non-operable and metastatic disease obtained from institutional data and a literature review. Costings for hospital admissions for mediastinoscopy and thoracotomy of actual patients with NSCLC were determined. The overall and average cost of managing patients was then calculated over a range of FDG-PET costs to derive projected cost savings to the community. The prevalence of histologically proven mediastinal involvement in patients with NSCLC presenting for surgical assessment at our institution is 20%, and the prevalence of distant metastatic disease is 6%. Based on literature review, the pooled sensitivity and specificity of FDG-PET for detection of mediastinal spread are 84% and 89% respectively, and for mediastinoscopy, 81% and 100%. The average cost of mediastinoscopy for NSCLC in our institution is AUD$4,160, while that of thoracotomy is AUD$15,642. The cost of an FDG-PET scan is estimated to be AUD$1,500. Using these figures and the decision tree model, the average cost saving is AUD$2,128 per patient. Routine FDG-PET scanning with selective mediastinoscopy will save AUD$2,128 per patient and will potentially reduce inappropriate surgery. These cost savings remain robust over a wide range of disease prevalence and FDG-PET costs. (orig.)

  9. Value of positron emission tomography and computer tomography (PET/CT) for urologic malignancies

    International Nuclear Information System (INIS)

    Positron emission tomography is a functional imaging technique that allows the detection of the regional metabolic rate, and is often coupled with other morphological imaging technique such as computed tomography. The rationale for its use is based on the clearly demonstrated fact that functional changes in tumor processes happen before morphological changes. Its introduction to the clinical practice added a new dimension in conventional imaging techniques. This review presents the current and proposed indications of the use of positron emission/computed tomography for prostate, bladder and testes, and the potential role of this exam in radiotherapy planning. (authors)

  10. [Value of positron emission tomography and computer tomography (PET/CT) for urologic malignancies].

    Science.gov (United States)

    Boujelbene, N; Prior, J O; Boubaker, A; Azria, D; Schaffer, M; Gez, E; Jichlinski, P; Meuwly, J-Y; Mirimanoff, R O; Ozsahin, M; Zouhair, A

    2011-07-01

    Positron emission tomography is a functional imaging technique that allows the detection of the regional metabolic rate, and is often coupled with other morphological imaging technique such as computed tomography. The rationale for its use is based on the clearly demonstrated fact that functional changes in tumor processes happen before morphological changes. Its introduction to the clinical practice added a new dimension in conventional imaging techniques. This review presents the current and proposed indications of the use of positron emission/computed tomography for prostate, bladder and testes, and the potential role of this exam in radiotherapy planning. PMID:21507695

  11. Perspectives for positron emission tomography with RPCs

    International Nuclear Information System (INIS)

    Full text: The basis of PET (Positron Emission Tomography) consists on the administration of a radioactive isotope attached to a tracer that permits to reveal its molecular pathways in a human body. A 3-D Complete-Body-Scan is desired in order to minimize the radiation dose to the patient and to increase the sensitivity of the axial field of view (FOV). A major candidate for gamma pair detection in 3-D Complete- Body-Scan are the RPCs (Resistive Plate Counters). They consist in a longitudinal microstrip grid 1.5 mm thick, spaced at 1 mm. The grid is placed between a large electric resistive glass anode and an aluminum cathode. The gap, around 300 m, is filled with a special gas and is polarized at around 6 kV. Every microstrip is equipped with high-speed preamplifier at both ends, allowing time of flight measurements. The RPC are solely tracking devices enjoying a large density of detection units. By construction they are able to provide an extremely large transverse resolution, the collecting leads being some 2.5 mm spaced. The longitudinal resolution is less sensitive, depending on the speed of the time of flight electronics. At this moment we estimate a 20 mm resolution. The RPCs present two main features: large longitudinal dimension and large transversal resolution which made them ideal for complete-body-scan devices. These peculiar features are the keys of a RPCs tomographic device. The evaluation of RPCs for 3-D Complete-Body-Scan followed two steps, the simulation of data acquisition and the image reconstruction. We choose the detecting base unit like a RPC, 2 meters long and 0.5 meters wide. According to previous assumptions this plate has a transverse resolution of 256 detection units and a longitudinal resolution of 100. (The transversal step is around 2 mm and the longitudinal step about 20 mm). Several base units are assembled to form different detecting structures. Two plates form an open detection structure like a sandwich. Four and six plates are

  12. Positron emission tomography in colorectal cancer;Tomografia por emissao de positron no cancer colorretal

    Energy Technology Data Exchange (ETDEWEB)

    Gabure, Jose Luiz de Carvalho; Bacega, Marcelle Francine [Universidade Cidade de Sao Paulo (UNICID), Sao Paulo, SP (Brazil); Racy, Douglas Jorge; Lima, Rodrigo Vaz de; Rigo, Leticia, E-mail: letirigo3@hotmail.co [Med Imagem Diagnosticos por Imagem, Sao Paulo, SP (Brazil)

    2009-12-15

    After an introduction on the physical and biological basics of positron emission tomography, this paper reviews the current status of PET imaging using the glucose analogue FDG in colorectal cancer. The use of PET-FDG is reviewed for detection, initial staging, therapy monitoring and staging of disease relapse. (author)

  13. Physical and technical basis of positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Positron emission tomography utilizes the annihilation of positrons, generating pairs of gamma quanta which are emitted in opposing directions. 'Electronic collimation' is performed by coincident detection of both quanta. Thus, there is no need for mechanical collimators and no limiting connection between sensitivity and spatial resolution. Transversal tomograms are reconstructed from the projection data by means of highly sophisticated data processing. The half life of the most positron emitters used in medical applications is short and of the order of some minutes. Therefore, many positron emitters have to be produced on-side by means of a cyclotron. PET is superior to SPECT with respect to physical and technical aspects, but the high costs of PET limit its wide-spread use up to now. (orig.)

  14. Improved sampling in positron emission tomography

    International Nuclear Information System (INIS)

    The biomedical research performed with the Donner 280-Crystal Positron Tomograph requires data acquisition times of five seconds or less and the ability to gate the data acquisition for periods during the cardiac cycle when the heart is nearly at rest. These requirements pose severe restrictions on the amount of detector movement and have motivated the search for a scheme that improves lateral sampling with a minimum number of detector positions. A new approach, developed by our group, involves only two positions of the detector assembly and increases lateral sampling uniformly by a factor of two. This new approach is referred as clamshell sampling. To test clamshell sampling we performed Monte Carlo computer simulations of data acquisition with the new geometry. Hot spots of varying sizes and separation comprise the model used in a geometry scaled to test imaging the human head with the Donner 280-Crystal Positron Tomograph

  15. Liquid Xenon Detectors for Positron Emission Tomography

    OpenAIRE

    Miceli, A.; Amaudruz, P.; Benard, F.; Bryman, D. A.; Kurchaninov, L.; Martin, J. P.; Muennich, A.; Retiere, F.; Ruth, T J.; Sossi, V.; A.J. Stoessl

    2011-01-01

    PET is a functional imaging technique based on detection of annihilation photons following beta decay producing positrons. In this paper, we present the concept of a new PET system for preclinical applications consisting of a ring of twelve time projection chambers filled with liquid xenon viewed by avalanche photodiodes. Simultaneous measurement of ionization charge and scintillation light leads to a significant improvement to spatial resolution, image quality, and sensitivity. Simulated per...

  16. Biological imaging in radiation therapy: role of positron emission tomography

    International Nuclear Information System (INIS)

    In radiation therapy (RT), staging, treatment planning, monitoring and evaluation of response are traditionally based on computed tomography (CT) and magnetic resonance imaging (MRI). These radiological investigations have the significant advantage to show the anatomy with a high resolution, being also called anatomical imaging. In recent years, so called biological imaging methods which visualize metabolic pathways have been developed. These methods offer complementary imaging of various aspects of tumour biology. To date, the most prominent biological imaging system in use is positron emission tomography (PET), whose diagnostic properties have clinically been evaluated for years. The aim of this review is to discuss the valences and implications of PET in RT. We will focus our evaluation on the following topics: the role of biological imaging for tumour tissue detection/delineation of the gross tumour volume (GTV) and for the visualization of heterogeneous tumour biology. We will discuss the role of fluorodeoxyglucose-PET in lung and head and neck cancer and the impact of amino acids (AA)-PET in target volume delineation of brain gliomas. Furthermore, we summarize the data of the literature about tumour hypoxia and proliferation visualized by PET. We conclude that, regarding treatment planning in radiotherapy, PET offers advantages in terms of tumour delineation and the description of biological processes. However, to define the real impact of biological imaging on clinical outcome after radiotherapy, further experimental, clinical and cost/benefit analyses are required. (topical review)

  17. Highly metabolic thrombus of the portal vein: 18F fluorodeoxyglucose positron emission tomography/computer tomography demonstration and clinical significance in hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To assess the ability of 18F-fluorodeoxyglucose positron emission tomography/computer tomography (18F-FDG PET/CT) to differentiate between benign and malignant portal vein thrombosis in hepatocellular carcinoma (HCC) patients. METHODS: Five consecutive patients who had HBV cirrhosis, biopsy-proven HCC, and thrombosis of the main portal vein and/or left/right portal vein on ultrasound (US), computer tomography (CT) or magnetic resonance imaging (MRI) were studied with 18F-FDG PET/CT. The presence or absence of a highly metabolic thrombus on 18F-FDG PET/CT was considered diagnostic for malignant or benign portal vein thrombosis, respectively. All patients were followed-up monthly with US, CT or MRI. Shrinkage of the thrombus or recanalization of the vessels on US, CT or MRI during follow-up was considered to be definitive evidence of the benign nature of the thrombosis, whereas enlargement of the thrombus, disruption of the vessel wall, and parenchymal infiltration over follow-up were considered to be consistent with malignancy 18F-FDG PET/CT, and US, CT or MRI results were compared. RESULTS: Follow-up (1 to 10 mo) showed signs of malignant thrombosis in 4 of the 5 patients. US, CT or MRI produced a true-positive result for malignancy in 4of the patients, and a false-positive result in 1.18F-FDG PET/CT showed a highly metabolic thrombus in 4 of the 5 patients.18F-FDG PET/CT achieved a true-positive result in all 4 of these patients, and a true-negative result in the other patient. No false-positive result was observed using 18F-FDG PET/CT.CONCLUSION: 18F-FDG PET/CT may be helpful in discriminating between benign and malignant portal vein thrombi. Patients may benefit from 18F-FDG PET/OT when portal vein thrombi can not be diagnosed exactly by US, CT or MRI.

  18. Clinical evaluation of iterative reconstruction (ordered-subset expectation maximization) in dynamic positron emission tomography: quantitative effects on kinetic modeling with N-13 ammonia in healthy subjects

    DEFF Research Database (Denmark)

    Hove, Jens D; Rasmussen, Rune; Freiberg, Jacob; Holm, Søren; Kelbaek, Henning; Kofoed, Klaus

    2008-01-01

    BACKGROUND: The purpose of this study was to investigate the quantitative properties of ordered-subset expectation maximization (OSEM) on kinetic modeling with nitrogen 13 ammonia compared with filtered backprojection (FBP) in healthy subjects. METHODS AND RESULTS: Cardiac N-13 ammonia positron e...

  19. Liquid Xenon Detectors for Positron Emission Tomography

    International Nuclear Information System (INIS)

    PET is a functional imaging technique based on detection of annihilation photons following beta decay producing positrons. In this paper, we present the concept of a new PET system for preclinical applications consisting of a ring of twelve time projection chambers filled with liquid xenon viewed by avalanche photodiodes. Simultaneous measurement of ionization charge and scintillation light leads to a significant improvement to spatial resolution, image quality, and sensitivity. Simulated performance shows that an energy resolution of < 10% (FWHM) and a sensitivity of 15% are achievable. First tests with a prototype TPC indicate position resolution < 1 mm (FWHM).

  20. Liquid Xenon Detectors for Positron Emission Tomography

    CERN Document Server

    Miceli, A; Benard, F; Bryman, D A; Kurchaninov, L; Martin, J P; Muennich, A; Retiere, F; Ruth, T J; Sossi, V; Stoessl, A J

    2011-01-01

    PET is a functional imaging technique based on detection of annihilation photons following beta decay producing positrons. In this paper, we present the concept of a new PET system for preclinical applications consisting of a ring of twelve time projection chambers filled with liquid xenon viewed by avalanche photodiodes. Simultaneous measurement of ionization charge and scintillation light leads to a significant improvement to spatial resolution, image quality, and sensitivity. Simulated performance shows that an energy resolution of <10% (FWHM) and a sensitivity of 15% are achievable. First tests with a prototype TPC indicate position resolution <1 mm (FWHM).

  1. Positron-emission tomography and cerebral metabolism

    International Nuclear Information System (INIS)

    In addition to the fact that radio-isotopes allow iso-atom labelling, they are short-lived and consequently may be injected into humans without serious problems of radiation damage. They disintegrate by emitting positrons which can be detected by external counting by virtue of the two 511 keV gamma rays emitted at the same time in opposite directions. These properties are used for tomographic detection and permit quantitative measurements of the radio-activity method will be described. The first concerns the transport of amino-acids into the brain, the second, the metabolism of psychoactive drugs. (orig./VJ)

  2. MR imaging and positron emission tomography of cortical heterotopia

    International Nuclear Information System (INIS)

    Heterotopia of the gray matter is a developmental malformation in which ectopic cortex is found in the white matter of the brain. A case of a 33-year-old man with cortical heterotopia who had a lifelong history of seizures and psychomotor retardation is reported, including the results of cerebral CT, magnetic resonance imaging, and positron emission tomography using 18F-2-deoxyglucose

  3. Physiopathology of ischemic strokes: the input of positron emission tomography

    International Nuclear Information System (INIS)

    The tomography by positrons emissions has brought essential physiological and pathological knowledge relative to cerebral vascular accidents in the acute phase, because it is possible to measure the cerebral blood flow, the oxygen extraction rate and the local oxygen consumption. (N.C.)

  4. Advance of molecular imaging with positron emission tomography

    International Nuclear Information System (INIS)

    Molecular imaging with positron emission tomography (PET) is an important field of molecular imaging. This article summarizes the fundamental of PET molecular imaging technique and its application in protein function, gene expression and gene therapy, receptor imaging, and blood-flow infusion and metabolism imaging. (authors)

  5. Skeletal muscle perfusion measured by positron emission tomography during exercise

    NARCIS (Netherlands)

    Ament, W; Lubbers, J; Rakhorst, G; Vaalburg, W; Verkerke, GJ; Paans, AMJ; Willemsen, ATM

    1998-01-01

    The applicability of (H2O)-O-15-positron emission tomographic (PET) imaging for the assessment of skeletal muscle perfusion during exercise was investigated in five healthy subjects performing intermittent isometric contractions on a calf ergometer. The workload of the left calf muscles was kept con

  6. 3D fast reconstruction in positron emission tomography

    International Nuclear Information System (INIS)

    The issue of long reconstruction times in positron emission tomography (PET) has been addressed from several points of view, resulting in an affordable dedicated system capable of handling routine 3D reconstructions in a few minutes per frame : on the hardware side using fast processors and a parallel architecture, and on the software side, using efficient implementation of computationally less intensive algorithms

  7. Utilisation of spatial and temporal correlations in positron emission tomography

    International Nuclear Information System (INIS)

    In this thesis we propose, implement, and evaluate algorithms improving spatial resolution in reconstructed images and reducing data noise in positron emission tomography imaging. These algorithms have been developed for a high resolution tomograph (HRRT) and applied to brain imaging, but can be used for other tomographs or studies. We first developed an iterative reconstruction algorithm including a stationary and isotropic model of resolution in image space, experimentally measured. We evaluated the impact of such a model of resolution in Monte-Carlo simulations, physical phantom experiments and in two clinical studies by comparing our algorithm with a reference reconstruction algorithm. This study suggests that biases due to partial volume effects are reduced, in particular in the clinical studies. Better spatial and temporal correlations are also found at the voxel level. However, other methods should be developed to further reduce data noise. We then proposed a maximum a posteriori de-noising algorithm that can be used for dynamic data to de-noise temporally raw data (sino-grams) or reconstructed images. The a priori modeled the coefficients in a wavelet basis of all the signals without noise (in an image or sinogram). We compared this technique with a reference de-noising method on replicated simulations. This illustrates the potential benefits of our approach of sinogram de-noising. (author)

  8. Positron Emission Tomography with Three-Dimensional Reconstruction

    International Nuclear Information System (INIS)

    The development of two different low-cost scanners for positron emission tomography (PET) based on 3D acquisition are presented. The first scanner consists of two rotating scintillation cameras, and produces quantitative images, which have shown to be clinically useful. The second one is a system with two opposed sets of detectors, based on the limited angle tomography principle, dedicated for mammographic studies. The development of low-cost PET scanners can increase the clinical impact of PET, which is an expensive modality, only available at a few centres world-wide and mainly used as a research tool. A 3D reconstruction method was developed that utilizes all the available data. The size of the data-sets is considerably reduced, using the single-slice rebinning approximation. The 3D reconstruction is divided into 1D axial deconvolution and 2D transaxial reconstruction, which makes it relatively fast. This method was developed for the rotating scanner, but was also implemented for multi-ring scanners with and without inter plane septa. An iterative 3D reconstruction method was developed for the limited angle scanner, based on the new concept of 'mobile pixels', which reduces the finite pixel errors and leads to an improved signal to noise ratio. 100 refs

  9. The natural history of misery perfusion in positron emission tomography

    International Nuclear Information System (INIS)

    This report reviews the natural courses of misery perfusion in 5 patients with atherosclerotic cerebrovascular occlusion diseases. Cases 1 showed partial improvement and Case 2 showed deterioration of misery perfusion on positron emission tomography (PET). These 2 patients did not show any clinical changes during the follow-up periods. Case 3 showed remarkable improvement of misery perfusion during the 2-year follow-ups, but his neurological condition worsened. The EC-IC bypass improved both in PET and clinical symptoms. Case 4 had a stroke at the region of misery perfusion in PET. Case 5 had a lacunar infarction 2 years after the EC-IC bypass on the opposite side. PET taken one month before the stroke did not show any signs of hypoperfusion in the area of the lacunar infarction. Misery perfusion seems not to be a static but a dynamic condition that can develop into cerebral infarction by some hemodynamic stresses. Cerebral cortical or lobar infarction may occur in the region of severe misery perfusion. EC-IC bypass may prevent impending infarction of the cerebral cortex by improving the regional cerebral blood flow. However, EC-CI bypass will not prevent the lacunar infarction of the basal ganglia or internal capsule. (author)

  10. Positron emission particle tracking-Application and labelling techniques

    Institute of Scientific and Technical Information of China (English)

    David J.Parker; Xianfeng Fan

    2008-01-01

    The positron emission particle tracking (PEPT) technique has been widely used in science and engineering to obtain detailed information on the motion and flow fields of fluids or granular materials in multiphase systems, for example, fluids in rock cracks, chemical reactors and food processors; dynamic behaviour of granular materials in chemical reactors, granulators, mixers, dryers, rotating kilns and ball mills. The information obtained by the PEPT technique can be used to optimise the design, operational conditions for a wide range of industrial process systems, and to evaluate modelling work. The technique is based on tracking radioactively labelled particles (up to three particles) by detecting the pairs of back-to-back 511 ke V -γ-rays arising from annihilation of emitted positrons. It therefore involves a positron camera, location algorithms for calculating the tracer location and speed, and tracer labelling techniques. This paper will review the particle tracking technique from tracking algorithm, tracer labelling to their application.

  11. Reconstruction Algorithms for Positron Emission Tomography and Single Photon Emission Computed Tomography and their Numerical Implementation

    CERN Document Server

    Fokas, A S; Marinakis, V

    2004-01-01

    The modern imaging techniques of Positron Emission Tomography and of Single Photon Emission Computed Tomography are not only two of the most important tools for studying the functional characteristics of the brain, but they now also play a vital role in several areas of clinical medicine, including neurology, oncology and cardiology. The basic mathematical problems associated with these techniques are the construction of the inverse of the Radon transform and of the inverse of the so called attenuated Radon transform respectively. We first show that, by employing mathematical techniques developed in the theory of nonlinear integrable equations, it is possible to obtain analytic formulas for these two inverse transforms. We then present algorithms for the numerical implementation of these analytic formulas, based on approximating the given data in terms of cubic splines. Several numerical tests are presented which suggest that our algorithms are capable of producing accurate reconstruction for realistic phanto...

  12. Positron emission tomography scans on kanji and kana

    International Nuclear Information System (INIS)

    We reanalyzed our positron emission tomography (PET) study on reading of Japanese kanji (morphogram) words, kana (phonogram) words and kana nonwords, using Statistical Parametric Mapping (SPM). The basal occipital and occipito-temporal areas were activated in common, among which activity was most pronounced in the fusiform/inferior temporal gyri with kanji and in the inferior occipital gyrus with kana. The results were consistent with the clinical observations that damage to the posterior inferior temporal cortex including the fusiform/inferior temporal gyri causes alexia with agraphia for kanji, whereas damage to the posterior occipital area including the inferior occipital gyrus causes pure alexia for kana. Bases on the present results and the lesion studies, a dual-route hypothesis that modifies Iwata's model of reading about the Japanese language was proposed. That is, the middle occipital gyrus, deep perisylvian temporoparietal cortex and posterior temporal gyrus constitute a dorsal route for reading and process phonology for words, whereas the inferior occipital, fusiform and posterior inferior temporal gyri constitute a ventral route for reading and process orthography and lexico-semantics for words. The ventral route may gain dominance in reading, according as a word is repeatedly presented. (author)

  13. Positron emission tomography scans on kanji and kana

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Yasuhisa [Mitsui Memorial Hospital, Tokyo (Japan)

    2002-12-01

    We reanalyzed our positron emission tomography (PET) study on reading of Japanese kanji (morphogram) words, kana (phonogram) words and kana nonwords, using Statistical Parametric Mapping (SPM). The basal occipital and occipito-temporal areas were activated in common, among which activity was most pronounced in the fusiform/inferior temporal gyri with kanji and in the inferior occipital gyrus with kana. The results were consistent with the clinical observations that damage to the posterior inferior temporal cortex including the fusiform/inferior temporal gyri causes alexia with agraphia for kanji, whereas damage to the posterior occipital area including the inferior occipital gyrus causes pure alexia for kana. Bases on the present results and the lesion studies, a dual-route hypothesis that modifies Iwata's model of reading about the Japanese language was proposed. That is, the middle occipital gyrus, deep perisylvian temporoparietal cortex and posterior temporal gyrus constitute a dorsal route for reading and process phonology for words, whereas the inferior occipital, fusiform and posterior inferior temporal gyri constitute a ventral route for reading and process orthography and lexico-semantics for words. The ventral route may gain dominance in reading, according as a word is repeatedly presented. (author)

  14. Software development for modeling positrons emission tomograph scanners

    International Nuclear Information System (INIS)

    The Geant4 Application for Tomographic Emission (GATE) is an international platform recognized and used to develop Computational Model Exposure (CME) in the context of Nuclear Medicine, although currently there are dedicated modules for applications in Radiotherapy and Computed Tomography (CT). GATE uses Monte Carlo (MC) methods, and has a scripting language of its own. The writing of scripts for simulation of a PET scanner in GATE involves a number of interrelated steps, and the accuracy of the simulation is dependent on the correct setup of the geometries involved, since the physical processes depend on them, as well as the modeling of electronic detectors in module Digitizer, for example. The manual implementation of this setup can be a source of errors, especially for users without experience in the field of simulations or without any previous knowledge of a programming language, and also due to the the fact that the modeling process in GATE still remains bounded to LINUX / UNIX based systems, an environment only familiar to a few. This becomes an obstacle for beginners and prevents the use of GATE by a larger number of users interested in optimizing their experiments and/or clinical protocols through a more accessible, fast and friendly application. The objective of this work is therefore to develop a user-friendly software for the modeling of Positron Emission Tomography called GUIGATE (Graphical User Interface for GATE), with specific modules dedicated to quality control in PET scanners. The results exhibit the features available in this first version of GUIGATE, present in a set of windows that allow users to create their input files, perform and display in real time the model and analyze its output file in a single environment, allowing so intuitively access the entire architecture of the GATE simulation and to CERN's data analyzer, the ROOT. (author)

  15. A novel clustering approach to positron emission particle tracking

    Science.gov (United States)

    Wiggins, Cody; Santos, Roque; Ruggles, Arthur

    2016-03-01

    A novel approach to positron emission particle tracking is presented based on determining regions of space with high density of line of response crossing via clustering. The method is shown to be able to accurately track multiple particles in systems where the number of particles is unknown and in which particles can enter and leave the field of view of the scanning system. This method is explored in various environments and its parametric dependence is studied.

  16. Microfluidics for Positron Emission Tomography (PET) Imaging Probe Development

    OpenAIRE

    Wang, Ming-Wei; Lin, Wei-Yu; Liu, Kan; Masterman-Smith, Michael; Shen, Clifton Kwang-Fu

    2010-01-01

    Due to increased needs for Positron Emission Tomography (PET) scanning, high demands for a wide variety of radiolabeled compounds will have to be met by exploiting novel radiochemistry and engineering technologies to improve the production and development of PET probes. The application of microfluidic reactors to perform radiosyntheses is currently attracting a great deal of interest because of their potential to deliver many advantages over conventional labeling systems. Microfluidic-based r...

  17. Positron emission tomography (PET) evaluation of abdominal aortic aneurysm (AAA)

    OpenAIRE

    SakalihasanN, Natzi; Van Damme, Hendrik; Gomez, P.; RIGO, PIERRE; Lapiere, C. M.; Nusgens, Betty; Limet, Raymond

    2002-01-01

    Background: aneurysmal disease is associated with all inflammatory Cell infiltrate and enzymatic degradation of the vessel wall. Aim of the study: to detect increased metabolic activity in abdominal aortic aneurysms (AAA) by means of positron emission tomography (PET-imaging). Study design: twenty-six patients with AAA underwent PET-imaging Results: in tell patients, PET-imaging revealed increased, fluoro-deoxy-glucose (18-FDG) uptake at the level of the aneurysm. Patients with positive PET-i...

  18. ENVISION, developing Positron Emission Tomography for particle therapy

    CERN Multimedia

    2013-01-01

    Particle therapy is an advanced technique of cancer radiation therapy, using protons or other ions to target the cancerous mass. ENVISION aims at developing medical imaging tools to improve the dose delivery to the patient, to ensure a safer and more effective treatment. The animation illustrates the use of Positron Emission Tomography (PET) for monitoring the dose during treatment. Produced by: CERN KT/Life Sciences and ENVISION Project Management: Manuela Cirilli 3D animation: Jeroen Huijben, Nymus3d

  19. Nonhuman Primate Positron Emission Tomography Neuroimaging in Drug Abuse Research

    OpenAIRE

    Howell, Leonard Lee; Murnane, Kevin Sean

    2011-01-01

    Positron emission tomography (PET) neuroimaging in nonhuman primates has led to significant advances in our current understanding of the neurobiology and treatment of stimulant addiction in humans. PET neuroimaging has defined the in vivo biodistribution and pharmacokinetics of abused drugs and related these findings to the time course of behavioral effects associated with their addictive properties. With novel radiotracers and enhanced resolution, PET neuroimaging techniques have also charac...

  20. Positron emission holography: A new method of creating positron camera images

    International Nuclear Information System (INIS)

    By simulating the presence of a Fresnel zone plate in a camera designed for positron emission tomography (PET), a hologram can be synthesized which permits full three-dimensional images of the positron distribution in the original object to be rapidly constructed. The method requires no additional apparatus to a standard PET system, which is also operated in the usual way. The trajectory of each photon pair, detected in coincidence, is weighted as if it had passed through a zone plate optimised to suit the problem, before recording its intercept with a (single) plane to produce the hologram. The final image is created by calculating the diffraction pattern of monochromatic light passed through this hologram; it may also be created optically. The method is described in detail and its attractions discussed. Results are presented of some simple objects obtained from holograms produced from PET camera data, in comparison with images created by conventional back-projection processing of the same data. (orig.)

  1. 18F-fluorodeoxyglucose positron emission tomography in uterine carcinosarcoma

    International Nuclear Information System (INIS)

    Uterine carcinosarcomas clinically confined to the uterus usually harbor occult metastases. We conducted a pilot study to evaluate the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in uterine carcinosarcoma. Patients with histologically confirmed uterine carcinosarcoma were enrolled. Abdominal and pelvic magnetic resonance imaging (MRI)/whole-body computed tomography (CT) scan, and whole-body 18F-FDG PET or PET/CT were undertaken for primary staging, evaluating response, and restaging/post-therapy surveillance. The clinical impact of 18F-FDG PET was determined on a scan basis. A total of 19 patients were recruited and 31 18F-FDG PET scans (including 8 scans performed on a PET/CT scanner) were performed. Positive impacts of scans were found in 36.8% (7/19) for primary staging, 66.7% (2/3) for monitoring response, and 11.1% (1/9) for restaging/post-therapy surveillance. PET excluded falsely inoperable disease defined by MRI in two patients. Aggressive treatment applying to three patients with PET-defined resectable stage IVB disease seemed futile. Two patients died of disease shortly after salvage therapy restaged by PET. With PET monitoring, one stage IVB patient treated by targeted therapy only was alive with good performance. Using PET did not lead to improvement of overall survival of this series compared with the historical control (n = 35) (P 0.779). The preliminary results suggest that 18F-FDG PET is beneficial in excluding falsely inoperable disease for curative therapy and in making a decision on palliation for better quality of life instead of aggressive treatment under the guidance of PET. PET seems to have limited value in post-therapy surveillance or restaging after failure. (orig.)

  2. Positron Emission Tomography in inflammatory cardiovascular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Renata Christian Martins; Gouvea, Clecio Maria, E-mail: renatafelix@cardiol.br, E-mail: renata.felix@inc.saude.gov.br [Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Carneiro, Michel Pontes [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil); Mesquita, Claudio Tinoco [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2014-10-15

    Many articles have demonstrated the role of PET-CT in the evaluation of inflammatory and infectious diseases of the cardiovascular system. The purpose of this article is to provide a review of the literature on this topic to identify clinical situations in which there is evidence of the usefulness of PET-CT in diagnostic and therapeutic evaluation.

  3. Positron Emission Tomography in inflammatory cardiovascular diseases

    International Nuclear Information System (INIS)

    Many articles have demonstrated the role of PET-CT in the evaluation of inflammatory and infectious diseases of the cardiovascular system. The purpose of this article is to provide a review of the literature on this topic to identify clinical situations in which there is evidence of the usefulness of PET-CT in diagnostic and therapeutic evaluation

  4. Positron emission tomography, physical bases and comparaison with other techniques

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a medical imaging technique that measures the three-dimensional distribution of molecules marked by a positron-emitting particle. PET has grown significantly in clinical fields, particularly in oncology for diagnosis and therapeutic follow purposes. The technical evolutions of this technique are fast. Among the technical improvements, is the coupling of the PET scan with computed tomography (CT). PET is obtained by intravenous injection of a radioactive tracer. The marker is usually fluorine (18F) embedded in a glucose molecule forming the 18-fluorodeoxyglucose (FDG-18). This tracer, similar to glucose, binds to tissues that consume large quantities of the sugar such cancerous tissue, cardiac muscle or brain. Detection using scintillation crystals (BGO, LSO, LYSO) suitable for high energy (511keV) recognizes the lines of the gamma photons originating from the annihilation of a positron with an electron. The electronics of detection or coincidence circuit is based on two criteria: a time window, of about 6 to 15 ns, and an energy window. This system measures the true coincidences that correspond to the detection of two photons of 511 kV from the same annihilation. Most PET devices are constituted by a series of elementary detectors distributed annularly around the patient. Each detector comprises a scintillation crystal matrix coupled to a finite number (4 or 6) of photomultipliers. The electronic circuit, or the coincidence circuit, determines the projection point of annihilation by means of two elementary detectors. The processing of such information must be extremely fast, considering the count rates encountered in practice. The information measured by the coincidence circuit is then positioned in a matrix or sinogram, which contains a set of elements of a projection section of the object. Images are obtained by tomographic reconstruction by powerful computer stations equipped with a software tools allowing the analysis and

  5. Positron emission tomography radioligands for in vivo imaging of Aβ plaques

    OpenAIRE

    Mason, N Scott; Mathis, Chester A.; Klunk, William E

    2013-01-01

    The development of positron emission tomography (PET) radioligands for the non-invasive imaging of amyloid-β plaque burden has been the focus of intense research efforts over the last decade. A variety of structural backbones have been investigated and several radiolabeled molecules have been evaluated in phase I (and later) clinical studies. These efforts have been driven by the desire not only to develop a suitable diagnostic imaging agent but also to develop a means to evaluate potential t...

  6. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography

    DEFF Research Database (Denmark)

    Christensen, Anders Nymark; Rydhög, J. S.; Søndergaard, Rikke Vicki;

    2016-01-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver......, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy...

  7. Fluorodeoxyglucose positron emission tomography-computed tomography findings in a case of xanthogranulomatous pyelonephritis

    OpenAIRE

    Joshi, Prathamesh; Lele, Vikram; Shah, Hardik

    2013-01-01

    Xanthogranulomatous pyelonephritis (XGNP) is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction. This condition can clinically present as recurrent urinary tract infections, flank pain, hematuria, and occasionally sepsis, and weight loss. This condition is usually associated with obstructing renal calculus. We present 18-fluorodeoxyglucose positron emission tomography-computed tomography (18-FDG PET/CT) findings in a...

  8. Optimization of In-Beam Positron Emission Tomography for Monitoring Heavy Ion Tumor Therapy

    OpenAIRE

    Vieira Crespo, Paulo Alexandre

    2010-01-01

    In-beam positron emission tomography (in-beam PET) is currently the only method for an in-situ monitoring of highly tumor-conformed charged hadron therapy. In such therapy, the clinical effect of deviations from treatment planning is highly minimized by implementing safety margins around the tumor and selecting proper beam portals. Nevertheless, in-beam PET is able to detect eventual, undesirable range deviations and anatomical modifications during fractionated irradiation, to verify the accu...

  9. The clinical significance and management of incidental focal FDG uptake in the thyroid gland on positron emission tomography/computed tomography (PET/CT) in patients with non-thyroidal malignancy

    International Nuclear Information System (INIS)

    Background Incidental focal fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG) uptake in the thyroid is not uncommon. A significant proportion is due to intercurrent thyroid cancer on further evaluation. Purpose To investigate and discuss the clinical significance and management of incidental focal FDG uptake in the thyroid gland on positron emission tomography/computed tomography (PET/CT) in patients with non-thyroidal malignancy. Material and Methods We investigated 188/7896 (2.4%) patients who had incidental focal thyroid uptake on FDG PET/CT in an oncology population over a 45-month period. Diagnosis was confirmed in 63 patients of whom 59 patients had histopathological verification. Results Thirty-two percent of confirmed cases were malignant comprising intercurrent thyroid cancer in three-quarters of these patients. Maximum standardized uptake values of the thyroid lesions and SUV ratios compared with background thyroid and mediastinal uptake were not predictive of a benign or malignant etiology. In patients with incidental thyroid cancers, more than half had non-papillary and intermediate to high-risk pathology. Conclusion Focal FDG uptake in the thyroid gland on PET/CT showed a malignancy risk of 32%. The intensity of uptake does not predict histology and underpins the importance of further investigations to exclude intercurrent thyroid cancer in suitable patients

  10. Positron emission tomography in the Rett syndrome

    International Nuclear Information System (INIS)

    A consistent constellation of clinical signs and symptoms define the Rett syndrome, the most prominent of which are disorders of movement and tone. Preliminary pathologic and neurochemical data indicate predominant involvement of the nigrostriatal dopaminergic pathways and the cholinergic system of the basal forebrain region. The age of onset differentiates the Rett syndrome from Alzheimer and Parkinson disease with similar lesions. PET scanning makes it possible to relate the chemistry of the brain to function by measuring the number and affinity of neuroreceptors, metabolism in specific brain regions, and provide important determinants of the underlying mechanisms in disease states. (author)

  11. Positron emission tomography (PET) in psychiatry

    International Nuclear Information System (INIS)

    Currently, clinical PET is mainly useful in psychiatry and related areas for differential diagnosis of dementia. In dementia of Alzheimer type reductions of glucose metabolism are found mainly in the temporoparietal assocaiton cortex, in Pick's disease mainly in the frontal cortex, and in Huntington's disease in the striatum. Other demential diseases usually show less toposelective metabolic impairment. In the future, new diagnostic possibilities may arise from analysis of functional stimulation of specific brain areas and from the use of ligands for specific neurotransmitter systems. (orig.)

  12. The imaging science of positron emission tomography

    International Nuclear Information System (INIS)

    To meet the goals of converging molecular imaging with molecular biology and molecular medicine, there is a need to define the strategy and structure for perfecting the accuracy of functional images derived using PET. This also relates directly to how clinical research, diagnostic questions and challenges from the pharmaceutical industry are addressed. In order to exploit the sensitivity and specificity of PET, an integrated, multidisciplinary approach is imperative. The structure to provide this needs to been seen in the context of an institutional approach, collaborations within the academic and industrial sectors and the funding needed to meet the challenges of addressing difficult questions. (orig.)

  13. Positron emission tomography and cerebral metabolism

    International Nuclear Information System (INIS)

    The association of new methods of labelling with short lived radioisotopes and of visualisation 'in vivo' of these labelled molecules by emission tomography, provide the possibility of studying brain metabolism at different levels. Two examples will illustrate the possibilities of this methodology. Cerebral metabolism of methionine-11C in phenylketonutic patients: The cerebral uptake of methionine was measured in 24 PKU children aged 1 to 40 months on a low protein diet. Ten of them were examined twice at intervals of several months. Stopping the diet for one week leads to an increase in blood phenylalanine and to a significant important decrease in brain uptake of labelled methionine. Futhermore, for children under treatment having a low phenylalanine blood concentration, brain uptake of methionine decreases with age between 1 and 40 months. These results suggest that the treatment of this disease should be started as soon as possible after birth. Cerebral metabolism of psychoactive drugs: The study of the brain distribution and kinetics of psychoactive drugs may help in understanding their mode of action. Chlorpromazine- 11C was administered i.v. to schyzophrenic patients not previously treated with neuroleptics. In all patients the brain uptake of the drug was high and rapid, and was localized mainly in the grey matter, probably in proportion to the blood flow. Non-specific binding of this drug to brain proteins prevented visualization of specific binding to dopaminergic or αnor-adrenergic receptors. Specific receptor binding of benzodiazepines was however visualized in the brain of baboons after injection of 11C-flunitrazepam (specific activity = 600 Ci/μmole) and subsequent displacement of this radioactive ligand by a pharmacological dose of Lorazepam

  14. Investigation of granular impact using positron emission particle tracking

    KAUST Repository

    Marston, Jeremy O.

    2015-04-01

    We present results from an experimental study of granular impact using a combination of high-speed video and positron emission particle tracking (PEPT). The PEPT technique exploits the annihilation of photons from positron decay to determine the position of tracer particles either inside a small granular bed or attached to the object which impacts the bed. We use dense spheres as impactors and the granular beds are comprised of glass beads which are fluidised to achieve a range of different initial packing states. For the first time, we have simultaneously investigated both the trajectory of the sphere, the motion of particles in a 3-D granular bed and particles which jump into the resultant jet, which arises from the collapse of the cavity formed by the impacting sphere.

  15. Study of patients with spinocerebellar degeneration using positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Susumu; Tanaka, Makoto; Sun, X.; Sakai, Yasujiro; Hirai, Shunsaku (Gunma Univ., Maebashi (Japan). School of Medicine)

    1993-10-01

    We studied cerebral blood flow, oxygen metabolism and their relation to clinical symptoms in 45 patients with spinocerebellar degeneration (SCD) and 12 normal control subjects using positron emission tomography (PET). Regions of interest were acquired for the cerebellar hemispheres, cerebellar vermis, brainstem, thalami, and cerebral cortices. PET studies revealed that regional cerebral blood flow (CBF), regional cerebral oxygen metabolic rate (CMRO[sub 2]), CBF/mean CBF of each cerebral cortex (CBF/mCBF) and CMRO[sub 2]/mean CMRO[sub 2] of each cerebral cortex (CMRO[sub 2]/mCMRO[sub 2]) in the cerebellar hemispheres, cerebellar vermis, and brainstem showed a significant decrease in comparison with the normal control subjects, while in the cerebral cortices and thalami, SCD patients showed normal values. CBF/mCBF and CMRO[sub 2]/mCMRO[sub 2] were significantly decreased in patients with olivo-pontocerebellar atrophy (OPCA) and Menzel type of hereditary ataxia (Menzel type) in the cerebellar hemispheres, cerebellar vermis, and brainstem, whereas patients with late cortical cerebellar atrophy (LCCA) and Holmes type of hereditary ataxia (Holmes type) revealed a significant decrease of CBF/mCBF and CMRO[sub 2]/mCMRO[sub 2] in the cerebellar hemispheres and cerebellar vermis, but not in the brainstem. Patients with OPCA showed a significant decrease of CBF in the cerebellar hemispheres, cerebellar vermis, brainstem and that of CMRO[sub 2] in the cerebellar hemispheres and cerebellar vermis. Patients with LCCA showed a significant decrease of CBF in the right cerebellar hemisphere and cerebellar vermis. In patients with LCCA and Holmes type, the severity of upper limb ataxia and dysdiadochocinesis were significantly correlated with CBF/mCBF and CMRO[sub 2]/mCMRO[sub 2] in the cerebellar hemispheres and brainstem. PET may be useful for diagnosing SCD and understanding its pathogenesis. (author).

  16. Positron Emission Tomography in the Management of Lung Cancer (NSCLC)

    International Nuclear Information System (INIS)

    Lung cancer is the leading cause of cancer deaths in men and the second most common cancer in women. Globally it remains the most commonly diagnosed cancer at 1.35 million, representing 12.4% of all new cancers. Almost half (49.9%) of the lung cancer cases occur in the developing countries of the world, which is a big change since 1980, when it was estimated that 69% were in developed countries. Although lung cancer is the most deadly of all the cancers, it is the only major cancer that does not have a widely accepted screening test. Lung cancer often presents as a solitary pulmonary nodule on chest radiographs, which are usually performed on patients as a preoperative screening test, or as a part of routine health screening, often in the absence of symptoms. Incidental detection can occur in up to 12% of cases in asymptomatic cases. It is clear that there is a need for the accurate diagnosis of these lesions. In recent years Positron early and Emission Tomography (PET) holds early and promise as a noninvasive investigative tool for the evaluation of lung cancer. 18F-FDG PET is currently indicated for the characterization of lung lesions, staging of non-small cell lung carcinoma (NSCLC), detection of distant metastases, and diagnosis of recurrent disease. PET/CT studies are also being increasingly employed in radiotherapy treatment also planning. Furthermore PET also plays an important role in monitoring of treatment response. On the face of it a PET-CT study may appear expensive. But in the overall context, PET/CT is cost-effective in the treatment of Lung cancer. The modality is the best discriminator of disease load if used in the correct clinical setting. It can do away with the need for multiple, many times needless investigations. It can reduce the number of futile operations, unwarranted interventions, as well as over and under treatments of lung cancer. (author)

  17. Metabolic and clinical assessment of efficacy of cryoablation therapy on skeletal masses by {sup 18}F-FDG positron emission tomography/computed tomography (PET/CT) and visual analogue scale (VAS): initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Masala, Salvatore; Bartolucci, Alberto D.; Mammucari, Matteo; Simonetti, Giovanni [University Hospital Tor Vergata, Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, Rome (Italy); Schillaci, Orazio; Calabria, Ferdinando [University Hospital Tor Vergata, Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, Rome (Italy); I.R.C.C.S. Neuromed, Department of Nuclear Medicine and Neuroradiology, Pozzilli (Italy); Policlinico Tor Vegata, Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, Rome (Italy)

    2011-02-15

    Various therapy modalities have been proposed as standard treatments in management of bone metastases. Radiation therapy remains the standard of care for patients with localized bone pain, but up to 30% of them do not experience notable pain relief. Percutaneous cryoablation is a minimally invasive technique that induces necrosis by alternately freezing and thawing a target tissue. This technique is successfully used to treat a variety of malignant and benign diseases in different sites. {sup 18}F-FDG positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) is a single technique of imaging that provides in a ''single step'' both morphological and metabolic features of neoplastic lesions of the bone. The aim of this study was to evaluate the efficacy of the cryosurgical technique on secondary musculoskeletal masses according to semi-quantitative PET analysis and clinical-test evaluation with the visual analogue scale (VAS). We enrolled 20 patients with painful bone lesions (score pain that exceeded 4 on the VAS) that were non-responsive to treatment; one lesion per patient was treated. All patients underwent a PET-CT evaluation before and 8 weeks after cryotherapy; maximum standardized uptake value (SUV{sub max}) was measured before and after treatment for metabolic assessment of response to therapy. After treatment, 18 patients (90%) showed considerable reduction in SUV{sub max} value (>50%) suggestive of response to treatment; only 2 patients did not show meaningful reduction in metabolic activity. Our preliminary study demonstrates that quantitative analysis provided by PET correlates with response to cryoablation therapy as assessed by CT data and clinical VAS evaluation. (orig.)

  18. Metabolic and clinical assessment of efficacy of cryoablation therapy on skeletal masses by 18F-FDG positron emission tomography/computed tomography (PET/CT) and visual analogue scale (VAS): initial experience

    International Nuclear Information System (INIS)

    Various therapy modalities have been proposed as standard treatments in management of bone metastases. Radiation therapy remains the standard of care for patients with localized bone pain, but up to 30% of them do not experience notable pain relief. Percutaneous cryoablation is a minimally invasive technique that induces necrosis by alternately freezing and thawing a target tissue. This technique is successfully used to treat a variety of malignant and benign diseases in different sites. 18F-FDG positron emission tomography/computed tomography (18F-FDG PET/CT) is a single technique of imaging that provides in a ''single step'' both morphological and metabolic features of neoplastic lesions of the bone. The aim of this study was to evaluate the efficacy of the cryosurgical technique on secondary musculoskeletal masses according to semi-quantitative PET analysis and clinical-test evaluation with the visual analogue scale (VAS). We enrolled 20 patients with painful bone lesions (score pain that exceeded 4 on the VAS) that were non-responsive to treatment; one lesion per patient was treated. All patients underwent a PET-CT evaluation before and 8 weeks after cryotherapy; maximum standardized uptake value (SUVmax) was measured before and after treatment for metabolic assessment of response to therapy. After treatment, 18 patients (90%) showed considerable reduction in SUVmax value (>50%) suggestive of response to treatment; only 2 patients did not show meaningful reduction in metabolic activity. Our preliminary study demonstrates that quantitative analysis provided by PET correlates with response to cryoablation therapy as assessed by CT data and clinical VAS evaluation. (orig.)

  19. Impact of fluorodeoxyglucose-positron emission tomography (FDG-PET) in the management of patients with cancer and other serious disorders: a clinical case based approach

    International Nuclear Information System (INIS)

    In this pictorial review, the impact of FDG-PET is illustrated with specific clinical case examples that would demonstrate the power and promise of this molecular imaging technique in managing a wide variety of disorders. The case vignettes depicted in this communication represent the ones where this modality can be utilized in the routine clinical scenario and can prove substantially beneficial to the patients of cancer and other serious disorders. Related discussions are drawn along with individual cases to enable the readers understand the further prospects of PET that are being explored at the present. (author)

  20. High-resolution PET [Positron Emission Tomography] for Medical Science Studies

    Science.gov (United States)

    Budinger, T. F.; Derenzo, S. E.; Huesman, R. H.; Jagust, W. J.; Valk, P. E.

    1989-09-01

    One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging.

  1. Clinical use of sentinel node (SN) mapping and 18F-fluorodeoxyglucose (FDG) positron emission tomography (TEP) in the management of cutaneous melanoma

    International Nuclear Information System (INIS)

    In France, there is a new case of melanoma for 10.000 inhabitants per year. This incidence has doubled in 10 years. Surgery of the primary site is the main treatment of this disease: however thanks to the concept of sentinel node (SN) the management of melanoma changes, it tends to include adjuvant treatments. Because of the isotopic detection of SN and the use of PET FDG, nuclear medicine plays a key role in melanoma. This paper aims to discuss the place of isotopic SN mapping and TEP FDG in clinical practice. (authors)

  2. The investigation of cerebrovascular disorders with positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) provides a non-invasive, regional, in vivo method to measure physiological parameters including cerebral blood flow, glucose and oxygen metabolism, blood volume, and pH. Measurement of these parameters not only enables a more complete understanding of the pathophysiology of acute cerebral ischemia and infarction, but provides objective criteria with which to better manage patients. This chapter will first discuss PET methodology and tracer techniques used in the investigation of patients with cerebrovascular disease and then describe the progress that has already resulted from applying these methods. 73 refs.; 7 figs

  3. Design of a volume-imaging positron emission tomograph

    International Nuclear Information System (INIS)

    Progress is reported in several areas of design of a positron volume imaging tomograph. As a means of increasing the volume imaged and the detector packing fraction, a lens system of detector light coupling is considered. A prototype layered scintillator detector demonstrates improved spatial resolution due to a unique Compton rejection capability.The conceptual design of a new mechanism for measuring scattered radiation during emission scans has been tested by Monte Carlo simulation. The problem of how to use effectively the resulting sampled scattered radiation projections is presented and discussed

  4. Positron Emission Tomography Imaging of Regional Pulmonary Perfusion and Ventilation

    OpenAIRE

    Musch, Guido; Venegas, Jose G.

    2005-01-01

    Positron emission tomography (PET) imaging is a noninvasive, quantitative method to assess pulmonary perfusion and ventilation in vivo. The core of this article focuses on the use of [13N]nitrogen (13N2) and PET to assess regional gas exchange. Regional perfusion and shunt can be measured with the 13N2–saline bolus infusion technique. A bolus of 13N2, dissolved in saline solution, is injected intravenously at the start of a brief apnea, while the tracer kinetics in the lung is measured by a s...

  5. Use of positron emission tomography in colorectal cancer

    International Nuclear Information System (INIS)

    The value of PET (Positron Emission Tomography) in colorectal cancer is presented. PET is a novel technique that uses F-18-FDG (fluorodeoxiglucose) to assess glucose metabolism by whole body imaging. It has been demonstrated that malignant cells have both increase of glucose uptake and utilization. In colorectal cancer, PET is indicated for staging, assess recurrence, liver metastasis and treatment follow-up. PET is more sensitive and specific than CT (Computed Tomography) and is cost effective. In 30% of cases PET may change patient management, avoiding unnecessary procedures (au)

  6. Imaging of brain activity by positron emission tomography

    International Nuclear Information System (INIS)

    Brain function is associated with regional energy metabolism and blood flow increase. Such brain activity is visualized by using external scintigraphy. Positron emission tomography (PET) is the currently available most superior technique, allowing three-dimensional imaging of subtle blood flow. In this article, imaging methods and application of PET are discussed in terms of the following items: (1) measurement of cerebral glucose consumption, (2) PET in persons with visual impairment, (3) association between brain function and regional cerebral blood flow, (4) measurement of cerebral blood flow, (5) method for decreasing noise in PET imaging, (6) anatomic standardization of PET images, and (7) speech load and regional cerebral activity images. (N.K.)

  7. Positron emission tomography. Present status and Romanian perspectives

    International Nuclear Information System (INIS)

    Basic principles of the positron emission tomography (PET) are summarised. The main PET methods using short-lived radioisotopes (i.e.11 C, 13 N, 15 O, 18 F) are briefly reviewed. Three types of particle accelerators for radioisotopes production and medical uses (including radiotherapy), corresponding to the proton energy (Ep p p < 200 MeV) are presented. PET imaging equipment and procedures are discussed. Main radiopharmaceuticals based on beta decay for PET studies and their role in medicine is also described. Finally, perspectives for a PET program in Romania (Cyclotron + Radiochemistry + Tomograph ) are discussed. (author)

  8. THE USE OF 18F-FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY TO ASSESS CLINICAL OUTCOMES OF PATIENTS WITH BORDERLINE RESECTABLE PANCREATIC CANCER.

    Science.gov (United States)

    Durmus, A; Yilmaz, A; Malya, F; Ozturk, G; Bektasoglu, H; Ertugrul, G; Karyagar, S; Karatepe, O

    2016-04-01

    The aim of this study is to evaluate the effect of 18FDG PET on preoperative staging and clinical management of pancreatic cancer. Between December 2011 and February 2015, 28 consecutive patients with borderline resectable pancreatic cancer were evaluated with both 18FDG PET scans and conventional preoperative imaging studies. Medical records of all patients were noted prospectively. 18FDG PET findings were compared with conventional imaging studies and over-staging or down-staging rates with changes in clinical management were evaluated. The correlation of 18FDG PET with conventional imaging studies was evaluated with a kappa agreement coefficient. A number of 22 (78.5%) patients had pancreatic head cancer and 6 (21.4%) patients had pancreatic body and tail cancers. Based on 18FDG PET, additional lesions were found in 4 (14.28%) of the patients which were lung and peritoneal lesions as metastasis. No hepatic metastasis or supraclavicular lymph node involvement was confirmed in patients. Routine use of 18FDG PET for preoperative staging has not an effect on cancer management in 96.8% of our patients. In conclusion, 18FDG PET has additional value over conventional radiologic techniques for monitoring the treatment response in locally advanced pancreatic cancer patients. It is feasible to predict early metastasis and patient outcome early (after one course of IC) during therapy. PMID:27249430

  9. Application of positron emission tomography in industrial research

    International Nuclear Information System (INIS)

    Positron Emission computed Tomography (PET) is a relatively new imaging technique, exploiting the 511 keV annihilation radiation characteristic of positron emitters. Although exclusively used till now in the field of nuclear medicine, the application of PET for the non-invasive, in-situ visualisation of processes of industrial interest is challenging, because PET can in principle be used to obtain quantitative, 2D/3D images of the flow and distribution of fluids inside process units, whose steel walls may be up to several centimeters thick. With the aid of a NeuroECAT positron tomographer the PET technique has been utilised to image important (model) processes in the petrochemical industry, using physical labelling of the phase to be imaged. First, the displacement of a brine/surfactant phase, labelled with 66Ga-EDTA, in a piece of reservoir rock was imaged. Secondly, the dehydration of water-in-oil emulsions was monitored dynamically by labelling the water phase with 68Ga-EDTA. The second study in particular demonstrates that in the presence of noisy data the image reconstruction method utilised strongly influences the results obtained. With the advent of PET in nuclear medicine the availability of short-lived positron emitting nuclides like 11C (t1/2 = 20 min), 13N (t1/2 = 10 min) and 150 (t1/2 = 2 min) has increased considerably, allowing the investigation of industrially important reactions by chemical labelling. Utilising the NeuroECAT in a special mode, the catalytic oxidation of carbon monoxide could be imaged in a model tubular reactor by using 11C-labelled CO, providing information about the kinetics of the individual reaction steps and interactions and about the degree of occupation of catalytically active sites. (author)

  10. Positron emission tomography in patients with head and neck carcinoma

    International Nuclear Information System (INIS)

    PURPOSE: To examine the role of positron emission tomography (PET) with labeled fluorodeoxyglucose (FDG) in patients with primary neoplasms of the head and neck. MATERIALS and METHODS: Between (9(92)) and (9(94)), forty-four FDG PET scans were performed on 27 patients with head and neck neoplasms. FDG uptake at the tumor sites was quantified with standardized uptake values (SUV). There were seven women and 20 men. Median age was 70 (37 - 85). All patients had squamous cell carcinoma except two with esthesioneuroblastoma. In six patients the primary site was occult and treatment consisted of surgery followed by radiation. In the other patients, primary sites included nasopharynx (2), base of tongue (6), tonsil (4), larynx (2), piriform sinus (3) paranasal sinuses (3) and multiple (1). Three were Stage II, four were Stage III, 11 were Stage IV and three had recurrent disease. Gross disease was treated by radiation (2), twice daily radiation (8) or concurrent chemotherapy and radiation (11). The median follow-up of survivors is 12 months (6 - 30). RESULTS: All patients had baseline scans prior to radiation therapy. In the six patients with occult primaries, no primary lesions were discovered by PET scans. In the other 21 patients, all known primary sites, regional node metastases and distant metastases demonstrated increased uptake on PET imaging. In one patient distant metastases were suggested on PET (but without corroborating clinical or radiographic evidence) and in two patients additional regional node metastases were discovered. Eleven patients had PET scans at the conclusion of radiation therapy. Five patients had complete responses by PET, two had major responses and four had partial responses. However, all these patients had good clinical responses and none have failed locally. Five patients had six scans during follow-up (at 3 to 12 months) to differentiate radiation changes from persistent disease. In four patients the PET scans were negative and they are

  11. A simple on-column preparation of [11C]choline. Automation and adaptation to routine production for clinical positron emission tomography (PET)

    International Nuclear Information System (INIS)

    [11C]Choline is currently a potential PET radiopharmaceutical for tumor imaging. For its routine PET application we have developed an automated synthesis system based on the Sep-Pak [11C]methylation method. A simple and highly sensitive method for the detection of residual 2-dimethylaminoethanol (DMAE) in [11C]choline injections was also developed by the combination of headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Using this system, [11C]choline ready for injection can be obtained in a decay corrected radiochemical yield of 88% with a radiochemical purity of >99% after optimizing reaction parameters. The total synthesis time was 16 min after the end of irradiation. The simplicity, the high efficiency, and the use of disposable components are advantageous for routine clinical use. (author)

  12. 'Serial review on clinical PET tracers'. Positron emission tomography with [11C]2-β-carbomethoxy-3β-(4-fluorophenyl) tropane for dopamine transporter

    International Nuclear Information System (INIS)

    [11C]2-β-carbomethoxy-3β-(4-fluorophenyl)tropane (11C-CFT) is a new radiotracer with a cocaine-structure and binds specifically to dopamine transporter located on the presynaptic dopaminergic terminal, which gives us in vivo information on dopamine transporter binding. The selectivity of 11C-CFT to the target region and the specificity of 11C-CFT is considerably high. The synthesis of the tracer is fairly stable. With these qualities, the tracer enables to illustrate the pathophysiology of Parkinson's disease (PD) or differentiate PD from brain disorders with Parkinsonisms. Moreover, it has been now in extensive use for other neurological and psychiatric diseases with dopaminergic abnormality. The clinical usefulness of 11C-CFT is described here. (author)

  13. Radiolabeled Phosphonium Salts as Mitochondrial Voltage Sensors for Positron Emission Tomography Myocardial Imaging Agents.

    Science.gov (United States)

    Kim, Dong-Yeon; Min, Jung-Joon

    2016-09-01

    Despite substantial advances in the diagnosis of cardiovascular disease, (18)F-labeled positron emission tomography (PET) radiopharmaceuticals remain necessary to diagnose heart disease because clinical use of current PET tracers is limited by their short half-life. Lipophilic cations such as phosphonium salts penetrate the mitochondrial membranes and accumulate in mitochondria of cardiomyocytes in response to negative inner-transmembrane potentials. Radiolabeled tetraphenylphosphonium cation derivatives have been developed as myocardial imaging agents for PET. In this review, a general overview of these radiotracers, including their radiosynthesis, in vivo characterization, and evaluation is provided and clinical perspectives are discussed. PMID:27540422

  14. Positron Emission Tomography of (64)Cu-DOTA-Rituximab in a Transgenic Mouse Model Expressing Human CD20 for Clinical Translation to Image NHL

    DEFF Research Database (Denmark)

    Natarajan, Arutselvan; Gowrishankar, Gayatri; Nielsen, Carsten Haagen;

    2012-01-01

    PURPOSE: This study aims to evaluate (64)Cu-DOTA-rituximab (PETRIT) in a preclinical transgenic mouse model expressing human CD20 for potential clinical translation. PROCEDURES: (64)Cu was chelated to DOTA-rituximab. Multiple radiolabeling, quality assurance, and imaging experiments were performed....... The human CD20 antigen was expressed in B cells of transgenic mice (CD20TM). The mice groups studied were: (a) control (nude mice, n¿=¿3) that received 7.4 MBq/dose, (b) with pre-dose (CD20TM, n¿=¿6) received 2 mg/kg pre-dose of cold rituximab prior to PETRIT of 7.4 MBq/dose, and (c) without pre......-dose (CD20TM, n¿=¿6) PETRIT alone received 7.4 MBq/dose. Small animal PET was used to image mice at various time points (0, 1, 2, 4, 24, 48, and 72 h). The OLINDA/EXM software was used to determine the human equivalent dose for individual organs. RESULTS: PETRIT was obtained with a specific activity of 545...

  15. {sup 18}F-Fluorodeoxyglucose positron emission tomography pulmonary imaging in idiopathic pulmonary fibrosis is reproducible: implications for future clinical trials

    Energy Technology Data Exchange (ETDEWEB)

    Win, Thida [Lister Hospital, Respiratory Medicine, Stevenage (United Kingdom); Lambrou, Tryphon; Hutton, Brian F.; Kayani, Irfan; Endozo, Raymondo; Shortman, Robert I.; Groves, Ashley M. [UCL/UCH, Institute of Nuclear Medicine, London (United Kingdom); Screaton, Nicholas J. [Papworth Hospital, Radiology Department, Cambridge (United Kingdom); Porter, Joanna C. [UCL/UCH, Centre for Respiratory Diseases, London (United Kingdom); Maher, Toby M. [Royal Brompton Hospital, Interstitial Lung Disease Unit, London (United Kingdom); Lukey, Pauline [GSK, Fibrosis DPU, Research and Development, Stevenage (United Kingdom)

    2012-03-15

    Noninvasive markers of disease activity in patients with idiopathic pulmonary fibrosis (IPF) are lacking. We performed this study to investigate the reproducibility of pulmonary {sup 18}F-FDG PET/CT in patients with IPF. The study group comprised 13 patients (11 men, 2 women; mean age 71.1 {+-} 9.9 years) with IPF recruited for two thoracic {sup 18}F-FDG PET/CT studies performed within 2 weeks of each other. All patients were diagnosed with IPF in consensus at multidisciplinary meetings as a result of typical clinical, high-resolution CT and pulmonary function test features. Three methods for evaluating pulmonary {sup 18}F-FDG uptake were used. The maximal {sup 18}F-FDG pulmonary uptake (SUVmax) in the lungs was determined using manual region-of-interest placement. An {sup 18}F-FDG uptake intensity histogram was automatically constructed from segmented lungs to evaluate the distribution of SUVs. Finally, mean SUV was determined for volumes-of-interest in pulmonary regions with interstitial lung changes identified on CT scans. Processing included correction for tissue fraction effects. Bland-Altman analysis was performed and interclass correlation coefficients (ICC) were determined to assess the reproducibility between the first and second PET scans, as well as the level of intraobserver and interobserver agreement. The mean time between the two scans was 6.3 {+-} 4.3 days. The interscan ICCs for pulmonary SUVmax analysis and mean SUV corrected for tissue fraction effects were 0.90 and 0.91, respectively. Intensity histograms were different in only 1 of the 13 paired studies. Intraobserver agreement was also excellent (0.80 and 0.85, respectively). Some bias was observed between observers, suggesting that serial studies would benefit from analysis by the same observer. This study demonstrated that there is excellent short-term reproducibility in pulmonary {sup 18}F-FDG uptake in patients with IPF. (orig.)

  16. F-18 fluoro-d-glucose positron emission tomography/computed tomography in a patient with corticobasal degeneration

    OpenAIRE

    Marti, Alejandro

    2015-01-01

    Corticobasal degeneration is a rare neurodegenerative disorder that often eludes clinical diagnosis. The present case shows the F-18 fluoro-d-glucose positron emission tomography/computed tomography (PET/CT) of a 62-year-old man with a progressive movement disorder with asymmetric features. PET/CT examination showed a markedly right-brain hemispheric hypometabolism also involving basal ganglia.

  17. F-18 fluoro-d-glucose positron emission tomography/computed tomography in a patient with corticobasal degeneration

    International Nuclear Information System (INIS)

    Corticobasal degeneration is a rare neurodegenerative disorder that often eludes clinical diagnosis. The present case shows the F-18 fluoro-d-glucose positron emission tomography/computed tomography (PET/CT) of a 62-year-old man with a progressive movement disorder with asymmetric features. PET/CT examination showed a markedly right-brain hemispheric hypometabolism also involving basal ganglia

  18. Basic principles of 18F-fluoro-deoxyglucose positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography uses photons to receive regional information about dynamic, physiologic, and biochemical processes in the living body. A positron decay is measured indirectly by the simultaneous registration of both gamma rays created by the annihilation. The event is counted, if two directly opposite located detectors register gamma rays in coincidence. Unfortunately the detectors of a positron emission tomography system do not register only true coincident events. There are also scattered and random coincidences. Different types of positron tomographs are presented and scintillation crystals, which are in use for positron emission tomography are discussed. The 2D- and 3D-acquisition methods are described as well as preprocessing methods, such as correction for attenuation, scatter and dead time. For quantification the relative parameter standard uptake value (SUV) is explained. Finally hybrid systems, such as combined positron emission tomography/computed tomography scanners and the use of computed tomography data for attenuation correction are introduced. (author)

  19. Simulation of the annihilation emission of galactic positrons; Modelisation de l'emission d'annihilation des positrons Galactiques

    Energy Technology Data Exchange (ETDEWEB)

    Gillard, W

    2008-01-15

    Positrons annihilate in the central region of our Galaxy. This has been known since the detection of a strong emission line centered on an energy of 511 keV in the direction of the Galactic center. This gamma-ray line is emitted during the annihilation of positrons with electrons from the interstellar medium. The spectrometer SPI, onboard the INTEGRAL observatory, performed spatial and spectral analyses of the positron annihilation emission. This thesis presents a study of the Galactic positron annihilation emission based on models of the different interactions undergone by positrons in the interstellar medium. The models are relied on our present knowledge of the properties of the interstellar medium in the Galactic bulge, where most of the positrons annihilate, and of the physics of positrons (production, propagation and annihilation processes). In order to obtain constraints on the positrons sources and physical characteristics of the annihilation medium, we compared the results of the models to measurements provided by the SPI spectrometer. (author)

  20. A controlled study of positron-emission-tomography and positron-emission-tomography/computed tomography in differential diagnosis of solitary pulmonary nodules-report of 60 cases

    Institute of Scientific and Technical Information of China (English)

    DING Qi-yong; HUA Yan-qing; ZHANG Guo-zhen; ZHAO Jun; GUAN Yi-hui; GE Xiao-jun; MAO Ding-biao; ZUO Chuan-tao

    2005-01-01

    @@ The differential diagnosis of solitary pulmonary nodules (SPNs) remains a challenge. It is acknowledged that combining positron-emission tomography (PET) and computed tomography (CT) offers the most reliable noninvasive method for the diagnosis of SPNs.

  1. 4.5 Tesla magnetic field reduces range of high-energy positrons -- Potential implications for positron emission tomography

    International Nuclear Information System (INIS)

    The authors have theoretically and experimentally investigated the extent to which homogeneous magnetic fields up to 7 Tesla reduce the spatial distance positrons travel before annihilation (positron range). Computer simulations of a noncoincident detector design using a Monte Carlo algorithm calculated the positron range as a function of positron energy and magnetic field strength. The simulation predicted improvements in resolution, defined as full-width at half-maximum (FWHM) of the line-spread function (LSF) for a magnetic field strength up to 7 Tesla: negligible for F-18, from 3.35 mm to 2.73 mm for Ga-68 and from 3.66 mm to 2.68 mm for Rb-82. Also a substantial noise suppression was observed, described by the full-width at tenth-maximum (FWTM) for higher positron energies. The experimental approach confirmed an improvement in resolution for Ga-68 from 3.54 mm at 0 Tesla to 2.99 mm FWHM at 4.5 Tesla and practically no improvement for F-18 (2.97 mm at 0 Tesla and 2.95 mm at 4.5 Tesla). It is concluded that the simulation model is appropriate and that a homogeneous static magnetic field of 4.5 Tesla reduces the range of high-energy positrons to an extent that may improve spatial resolution in positron emission tomography

  2. 77 FR 21783 - Guidance on Media Fills for Validation of Aseptic Preparations for Positron Emission Tomography...

    Science.gov (United States)

    2012-04-11

    ... the same title was announced in the Federal Register on September 30, 2011 (76 FR 60847), and Docket... Preparations for Positron Emission Tomography Drugs; Availability AGENCY: Food and Drug Administration, HHS... guidance entitled ``Media Fills for Validation of Aseptic Preparations for Positron Emission...

  3. 77 FR 71802 - Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    Science.gov (United States)

    2012-12-04

    ... announced in the Federal Register on February 14, 2012 (77 FR 8262), and Docket No. FDA-2012-D- 0081 was... Positron Emission Tomography Drugs; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice... ``Investigational New Drug Applications for Positron Emission Tomography (PET) Drugs.'' The guidance is intended...

  4. Functional images analysis and visualization in positron emission tomography

    International Nuclear Information System (INIS)

    Essentially new information on the metabolism and pathophysiology is available since the recent past using techniques combining the use of positron emitters labelling radiopharmaceuticals, models correctly describing the process studied and system for the in vivo external detection of transverse section of the body. This method is currently called Positron Emission Tomography (PET). At the Service Hospitalier Frederic Joliot of the C.E.A. Departement of Biology, a system was developed for data analysis and colour-coded representation as a tool for functional interpretation. Indeed, the tomographic images, i.e. the radioactive concentration in the transverse section is often but the first step of the study, the actual goal being the regional distribution of a metabolic or physiologic parameter, itself derived from the former distribution by assumption of a model. Such a quantification assumes an accurate analysis of the factors involved in the obtention of the functional image, and the development of the software actually adapted to the clinician's needs. Special attention was given to the representation of graphs and images as a man-machine interface, a tool for model fitting and output of final results in pseudo-color scales adapted to the studied parameter

  5. The metabolic landscape of cortico-basal ganglionic degeneration: regional asymmetries studied with positron emission tomography.

    OpenAIRE

    Eidelberg, D.; Dhawan, V; Moeller, J R; Sidtis, J.J.; Ginos, J Z; Strother, S C; Cederbaum, J.; Greene, P; Fahn, S; Powers, J M

    1991-01-01

    Regional metabolic rate for glucose (rCMRGlc) was estimated using [18F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) in five patients (four men, one woman; mean age 68; mean disease duration 2.4 years) with clinical findings consistent with the syndrome of cortico-basal ganglionic degeneration (CBGD). Left-right rCMRGlc asymmetry, (L-R)/(L + R) x 100, was calculated for 13 grey matter regions and compared with regional metabolic data from 18 normal volunteers and nine patien...

  6. New developments in molecular imaging: positron emission tomography time-of-flight (TOF-PET)

    International Nuclear Information System (INIS)

    Positron Emission tomography (PET) in increasingly being used in oncology for the diagnosis and staging of disease, as well as in monitoring response to therapy. One of the last advances in PET is the incorporation of Time-of-Flight (TOF) information, which improves the tomographic reconstruction process and subsequently the quality of the final image. In this work, we explain the principles of PET and the fundamentals of TOF-PET. Clinical images are shown in order to illustrate how TOF-PET improves the detectability of small lesions, particularly in patients with high body mass index. (Author) 20 refs

  7. Measurement of human blood brain barrier integrity using 11C-inulin and positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) using 11C-inulin was demonstrated to be applicable to the clinical measurement of blood brain barrier permeability and cerebral interstitial fluid volume. Kinetic data were analyzed by application of a two compartment model, in which blood plasma and interstitial fluid spaces constitute the compartments. The blood activity contribution was subtracted from the PET count with the aid of the 11CO inhalation technique. The values we estimated in a human brain were in agreement with the reported values obtained for animal brains by the use of 14C-inulin. (orig.)

  8. Fluorodeoxyglucose positron emission tomography-computed tomography findings in a case of xanthogranulomatous pyelonephritis

    International Nuclear Information System (INIS)

    Xanthogranulomatous pyelonephritis (XGNP) is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction. This condition can clinically present as recurrent urinary tract infections, flank pain, hematuria, and occasionally sepsis, and weight loss. This condition is usually associated with obstructing renal calculus. We present 18-fluorodeoxyglucose positron emission tomography-computed tomography (18-FDG PET/CT) findings in an elderly male suffering from pyrexia and weight loss and suspected urinary tract infection. PET/CT findings in this case lead to diagnosis of XGNP. This diagnosis should be kept in mind while evaluating similar symptoms and PET/CT scan findings. (author)

  9. New techniques for positron emission tomography in the study of human neurological disorders

    International Nuclear Information System (INIS)

    We continue our focus to develop more cost effective and efficient means for producing new functionally specific tracers and more simple, less expensive, means for acquiring and interpreting quantitative data. These improved processes are required for the future growth of positron emission tomography (PET) as a sophisticated research meeting and for the transfer of this technology to clinical use. Our approach concentrates on two separate yet related areas, radiosynthesis and data analysis. The program is divided into four subprojects, the first pair related to radiosynthesis, and the second pair related to data analysis. Progress during the past project year has been excellent in both accomplishment and publication record. 26 refs

  10. Distributed microprocessor automation network for synthesizing radiotracers used in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Russell, J.A.G.; Alexoff, D.L.; Wolf, A.P.

    1984-09-01

    This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. 20 refs. (DT)

  11. Distributed Microprocessor Automation Network for Synthesizing Radiotracers Used in Positron Emission Tomography [PET

    Science.gov (United States)

    Russell, J. A. G.; Alexoff, D. L.; Wolf, A. P.

    1984-09-01

    This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. (DT)

  12. Distributed microprocessor automation network for synthesizing radiotracers used in positron emission tomography

    International Nuclear Information System (INIS)

    This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. 20 refs. (DT)

  13. Methodological review on functional neuroimaging using positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hae Jeong [Yonsei University, College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Advance of neuroimaging technique has greatly influenced recent brain research field. Among various neuroimaging modalities, positron emission tomography has played a key role in molecular neuroimaging though functional MRI has taken over its role in the cognitive neuroscience. As the analysis technique for PET data is more sophisticated, the complexity of the method is more increasing. Despite the wide usage of the neuroimaging techniques, the assumption and limitation of procedures have not often been dealt with for the clinician and researchers, which might be critical for reliability and interpretation of the results. In the current paper, steps of voxel-based statistical analysis of PET including preprocessing, intensity normalization, spatial normalization, and partial volume correction will be revisited in terms of the principles and limitations. Additionally, new image analysis techniques such as surface-based PET analysis, correlational analysis and multimodal imaging by combining PET and DTI, PET and TMS or EEG will also be discussed.

  14. Studies of the brain cannabinoid system using positron emission tomography

    International Nuclear Information System (INIS)

    Studies using radiolabeled psychoactive drugs in conjunction with positron emission tomography (PET) have permitted the imaging of binding sites in the human brain. Similar studies of marijuana have been hampered by the unsuitability of radiolabeled THC for PET studies, and the current unavailability of other in vivo imaging agents for cannabinoid receptors. Recent developments in medicinal chemistry suggest that a PET radiotracer for cannabinoid receptors will soon become available. This chapter briefly reviews these developments, together with the results of PET studies of the effects of marijuana and other abused drugs on brain metabolism. It also reviews PET studies of cocaine binding sites, to demonstrate the kind of investigations that will be possible when a cannabinoid receptor PET radioligand becomes available

  15. Studies of the brain cannabinoid system using positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gatley, S.J.; Volkow, N.D.

    1995-10-01

    Studies using radiolabeled psychoactive drugs in conjunction with positron emission tomography (PET) have permitted the imaging of binding sites in the human brain. Similar studies of marijuana have been hampered by the unsuitability of radiolabeled THC for PET studies, and the current unavailability of other in vivo imaging agents for cannabinoid receptors. Recent developments in medicinal chemistry suggest that a PET radiotracer for cannabinoid receptors will soon become available. This chapter briefly reviews these developments, together with the results of PET studies of the effects of marijuana and other abused drugs on brain metabolism. It also reviews PET studies of cocaine binding sites, to demonstrate the kind of investigations that will be possible when a cannabinoid receptor PET radioligand becomes available.

  16. Timing performance comparison of digital methods in positron emission tomography

    International Nuclear Information System (INIS)

    Accurate timing information is essential in positron emission tomography (PET). Recent improvements in high speed electronics made digital methods more attractive to find alternative solutions to create a time mark for an event. Two new digital methods (mean PMT pulse model, MPPM, and median filtered zero crossing method, MFZCM) were introduced in this work and compared to traditional methods such as digital leading edge (LE) and digital constant fraction discrimination (CFD). In addition, the performances of all four digital methods were compared to analog based LE and CFD. The time resolution values for MPPM and MFZCM were measured below 300 ps at 1.6 GS/s and above that was similar to the analog based coincidence timing results. In addition, the two digital methods were insensitive to the changes in threshold setting that might give some improvement in system dead time.

  17. Magnet development for the BRF positron emission tomography accelerator

    International Nuclear Information System (INIS)

    A collaboration involving the Biomedical Research Foundation, Science Applications International Corporation, Fermi National Accelerator Laboratory, and the University of Washington is developing an accelerator for producing isotopes for Positron Emission Tomography (PET) scans. The Medium Energy Beam Transport (MEBT) section of this accelerator takes a small beam from a first RFQ acceleration device and matches it into a small 3D-acceptance at a second RFQ section. The beam transport system was designed to prevent beam losses due to emittance growth. The system includes two bending dipoles and seven quadrupoles of three different types. This report contains a brief description of the MEBT magnets and their electric, magnetic and thermal properties. The magnet measurements show that each of the magnets meets the system requirements

  18. Knowledge-based automated radiopharmaceutical manufacturing for Positron Emission Tomography

    International Nuclear Information System (INIS)

    This article describes the application of basic knowledge engineering principles to the design of automated synthesis equipment for radiopharmaceuticals used in Positron Emission Tomography (PET). Before discussing knowledge programming, an overview of the development of automated radiopharmaceutical synthesis systems for PET will be presented. Since knowledge systems will rely on information obtained from machine transducers, a discussion of the uses of sensory feedback in today's automated systems follows. Next, the operation of these automated systems is contrasted to radiotracer production carried out by chemists, and the rationale for and basic concepts of knowledge-based programming are explained. Finally, a prototype knowledge-based system supporting automated radiopharmaceutical manufacturing of 18FDG at Brookhaven National Laboratory (BNL) is described using 1stClass, a commercially available PC-based expert system shell

  19. Radiopharmaceuticals for positron emission tomography investigations of Alzheimer's disease

    International Nuclear Information System (INIS)

    Alzheimer's disease (AD) is a common degenerative neurological disease that is an increasing medical, economical, and social problem. There is evidence that a long ''asymptomatic'' phase of the disease exists where functional changes in the brain are present, but structural imaging for instance with magnetic resonance imaging remains normal. Positron emission tomography (PET) is one of the tools by which it is possible to explore changes in cerebral blood flow and metabolism and the functioning of different neurotransmitter systems. More recently, investigation of protein aggregations such as amyloid deposits or neurofibrillary tangles containing tau-protein has become possible. The purpose of this paper is to review the current knowledge on various 18F- and 11C-labelled PET tracers that could be used to study the pathophysiology of AD, to be used in the early or differential diagnosis or to be used in development of treatment and in monitoring of treatment effects. (orig.)

  20. Development of the LBNL positron emission mammography camera

    International Nuclear Information System (INIS)

    We present the construction status of the LBNL Positron Emission Mammography (PEM) camera, which utilizes a PET detector module with depth of interaction measurement consisting of 64 LSO crystals (3x3x30 mm3) coupled on one end to a single photomultiplier tube (PMT) and on the opposite end to a 64 pixel array of silicon photodiodes (PDs). The PMT provides an accurate timing pulse, the PDs identify the crystal of interaction, the sum provides a total energy signal, and the PD/(PD+PMT) ratio determines the depth of interaction. We have completed construction of all 42 PEM detector modules. All data acquisition electronics have been completed, fully tested and loaded onto the gantry. We have demonstrated that all functions of the custom IC work using the production rigid-flex boards and data acquisition system. Preliminary detector module characterization and coincidence data have been taken using the production system, including initial images

  1. Methodological review on functional neuroimaging using positron emission tomography

    International Nuclear Information System (INIS)

    Advance of neuroimaging technique has greatly influenced recent brain research field. Among various neuroimaging modalities, positron emission tomography has played a key role in molecular neuroimaging though functional MRI has taken over its role in the cognitive neuroscience. As the analysis technique for PET data is more sophisticated, the complexity of the method is more increasing. Despite the wide usage of the neuroimaging techniques, the assumption and limitation of procedures have not often been dealt with for the clinician and researchers, which might be critical for reliability and interpretation of the results. In the current paper, steps of voxel-based statistical analysis of PET including preprocessing, intensity normalization, spatial normalization, and partial volume correction will be revisited in terms of the principles and limitations. Additionally, new image analysis techniques such as surface-based PET analysis, correlational analysis and multimodal imaging by combining PET and DTI, PET and TMS or EEG will also be discussed

  2. Positron Emission Tomography in the Differential Diagnosis of Parkinsonism

    Directory of Open Access Journals (Sweden)

    Juha O Rinne

    2009-10-01

    Full Text Available Positron emission tomography (PET studies on presynaptic dopaminergic function can reveal hypofunction in early Parkinson’s disease (PD which may help in the early diagnosis especially in patients with mild symptoms. This hypofunction can be detected with fluorodopa (reflecting mainly aromatic amino acid decarboxylase activity of nigrostriatal terminals or dopamine transporter ligands. These studies can also help to distinguish PD from essential tremor. However, investigations of presynaptic dopaminergic function are not useful in the differential diagnosis of parkinsonian syndromes. PET ligands, such as fluorodeoxyglucose (reflecting glucose metabolism and dopamine receptor ligands, reflecting striatal neuronal function are better in this respect. Cardiac sympathetic function studies represent a new and interesting approach to improve differential diagnosis of parkinsonian syndromes but more studies are needed in larger patient populations with longer follow-up to evaluate the usefulness of these investigations. Multitracer approach combining ligands reflecting different aspects of dopaminergic neurotransmission and other physiological function will increase differential diagnostic accuracy.

  3. Investigation of language lateralization mechanism by Positron Emission Tomography

    International Nuclear Information System (INIS)

    As language lateralization in the brain left hemisphere is one of the most well known but less understood characteristics of the human brain, this research thesis reports the use of brain functional imaging to address some specific aspects of this lateralization. In a first part, the author reports the study of mechanisms of recovery from aphasia after a left hemisphere lesion within a population of aphasic right-handers. Based on a contrast between patients with a persistent aphasia despite usual language therapies, and patients with a significant recovery after a melodic and rhythmic therapy (TMR), a PET-based (positron emission tomography) activation study has been developed, based on the opposition between usual language stimuli and stimuli accentuated by TMR. In the second part, the author explored more systematically on sane patients the influence of some physical characteristics of auditory stimulation on the induced functional asymmetry

  4. Positron Emission Tomography: state of the art and future developments

    Science.gov (United States)

    Pizzichemi, M.

    2016-08-01

    Positron emission tomography (PET) plays a fundamental role in medical imaging, with a wide range of applications covering, among the others, oncology, neurology and cardiology. PET has undergone a steady technological evolution since its introduction in mid 20th century, from the development of 3D PET in the late 1980s, to the invention of PET/CT in the 1990s and more recently with the introduction of PET/MR scanners. The current research topics aiming to develop the next generation of PET scanners are summarized in this paper, focusing on the efforts to increase the sensitivity of the detectors, as long as improving their timing, spatial and energy resolutions, with the final goal of reducing the amount of radioactive dose received by the patients and the duration of the exams while improving at the same time the detectability of lesions.

  5. FEASIBILITY OF POSITRON EMISSION TOMOGRAPHY OF DOSE DISTRIBUTION IN PROTON BEAM CANCER THERAPY.

    Energy Technology Data Exchange (ETDEWEB)

    BEEBE - WANG,J.J.; DILMANIAN,F.A.; PEGGS,S.G.; SCHLYEER,D.J.; VASKA,P.

    2002-06-03

    Proton therapy is a treatment modality of increasing utility in clinical radiation oncology mostly because its dose distribution conforms more tightly to the target volume than x-ray radiation therapy. One important feature of proton therapy is that it produces a small amount of positron-emitting isotopes along the beam-path through the non-elastic nuclear interaction of protons with target nuclei such as {sup 12}C, {sup 14}N, and {sup 16}O. These radioisotopes, mainly {sup 11}C, {sup 13}N and {sup 15}O, allow imaging the therapy dose distribution using positron emission tomography (PET). The resulting PET images provide a powerful tool for quality assurance of the treatment, especially when treating inhomogeneous organs such as the lungs or the head-and-neck, where the calculation of the dose distribution for treatment planning is more difficult. This paper uses Monte Carlo simulations to predict the yield of positron emitters produced by a 250 MeV proton beam, and to simulate the productions of the image in a clinical PET scanner.

  6. Monitoring and management of lung cancer patients following curative-intent treatment: clinical utility of 2-deoxy-2-[fluorine-18]fluoro-d-glucose positron emission tomography/computed tomography

    Directory of Open Access Journals (Sweden)

    Sawada S

    2016-04-01

    Full Text Available Shigeki Sawada, Hiroshi Suehisa, Tsuyoshi Ueno, Ryujiro Sugimoto, Motohiro Yamashita Department of Thoracic Surgery, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan Abstract: A large number of studies have demonstrated that 2-deoxy-2-[fluorine-18]fluoro-d-glucose positron emission tomography/computed tomography (FDG-PET/CT is superior to conventional modalities for the diagnosis of lung cancer and the evaluation of the extent of the disease. However, the efficacy of PET/CT in a follow-up surveillance setting following curative-intent treatments for lung cancer has not yet been established. We reviewed previous papers and evaluated the potential efficacy of PET-CT in the setting of follow-up surveillance. The following are our findings: 1 PET/CT is considered to be superior or equivalent to conventional modalities for the detection of local recurrence. However, inflammatory changes and fibrosis after treatments in local areas often result in false-positive findings; 2 the detection of asymptomatic distant metastasis is considered to be an advantage of PET/CT in a follow-up setting. However, it should be noted that detection of brain metastasis with PET/CT has some limitation, similar to its use in pretreatment staging; 3 additional radiation exposure and higher medical cost arising from the use of PET/CT should be taken into consideration, particularly in patients who might not have cancer after curative-intent treatment and are expected to have a long lifespan. The absence of any data regarding survival benefits and/or improvements in quality of life is another critical issue. In summary, PET/CT is considered to be more accurate and sensitive than conventional modalities for the detection of asymptomatic recurrence after curative-intent treatments. These advantages could modify subsequent management in patients with suspected recurrence and might contribute to the selection of appropriate treatments for recurrence

  7. Evaluation of blood-brain barrier permeability changes in rhesus monkeys and man using 82Rb and positron emission tomography

    International Nuclear Information System (INIS)

    Dynamic positron tomography of the brain with /sup 82/Rb, obtained from a portable generator [/sup 82/Sr (25 days) - /sup 82/Rb (76 sec)], provides a means of studying blood-brain barrier (BBB) permeability in physiological and clinical investigations. The BBB in rhesus monkeys was opened unilaterally be intracarotid infusion of 3 M urea. This osmotic barrier opening allowed entry into the brain of intravenously administered rubidium chloride. The BBB opening was demonstrated noninvasively using /sup 82/Rb and positron emission tomography and corroborated by the accumulation of /sup 86/Rb in tissue samples. Positron emission tomography studies can be repeated every 5 min and indicate that dynamic tomography or static imaging can be used to study BBB permeability changes induced by a wide variety of noxious stimuli. Brain tumors in human subjects are readily detected because of the usual BBB permeability disruption in and around the tumors

  8. Evaluation of blood--brain barrier permeability changes in rhesus monkeys and man using 82Rb and positron emission tomography

    International Nuclear Information System (INIS)

    Dynamic positron tomography of the brain with 82Rb, obtained from a portable generator [82Sr (25 days) -- 82Rb (76 sec)], provides a means of studying blood-brain barrier (BBB) permeability in physiological and clinical investigations. The BBB in rhesus monkeys was opened unilaterally by intracarotid infusion of 3 M urea. This osmotic barrier opening allowed entry into the brain of intravenously administered rubidium chloride. The BBB opening was demonstrated noninvasively using 82Rb and positron emission tomography and corroborated by the accumulation of 86Rb in tissue samples. Positron emission tomography studies can be repeated every 5 min and indicate that dynamic tomography or static imaging can be used to study BBB permeability changes induced by a wide variety of noxious stimuli. Brain tumors in human subjects are readily detected because of the usual BBB permeability disruption in and around the tumors

  9. Calculation of Positron Distribution in the Presence of a Uniform Magnetic Field for the Improvement of Positron Emission Tomography (PET) Imaging Using GEANT4 Toolkit

    OpenAIRE

    Mohsen Mashayekhi; Ali Asghar Mowlavi

    2015-01-01

    Introduction Range and diffusion of positron-emitting radiopharmaceuticals are important parameters for image resolution in positron emission tomography (PET). In this study, GEANT4 toolkit was applied to study positron diffusion in soft tissues with and without a magnetic field for six commonly used isotopes in PET imaging including 11C, 13N, 15O, 18F, 68Ga, and 82Rb. Materials and Methods GEANT4 toolkit was used to simulate the transport and interactions of positrons. Calculations ...

  10. Molecular Imaging of Transporters with Positron Emission Tomography

    Science.gov (United States)

    Antoni, Gunnar; Sörensen, Jens; Hall, Håkan

    Positron emission tomography (PET) visualization of brain components in vivo is a rapidly growing field. Molecular imaging with PET is also increasingly used in drug development, especially for the determination of drug receptor interaction for CNS-active drugs. This gives the opportunity to relate clinical efficacy to per cent receptor occupancy of a drug on a certain targeted receptor and to relate drug pharmacokinetics in plasma to interaction with target protein. In the present review we will focus on the study of transporters, such as the monoamine transporters, the P-glycoprotein (Pgp) transporter, the vesicular monoamine transporter type 2, and the glucose transporter using PET radioligands. Neurotransmitter transporters are presynaptically located and in vivo imaging using PET can therefore be used for the determination of the density of afferent neurons. Several promising PET ligands for the noradrenaline transporter (NET) have been labeled and evaluated in vivo including in man, but a really useful PET ligand for NET still remains to be identified. The most promising tracer to date is (S,S)-[18F]FMeNER-D2. The in vivo visualization of the dopamine transporter (DAT) may give clues in the evaluation of conditions related to dopamine, such as Parkinson's disease and drug abuse. The first PET radioligands based on cocaine were not selective, but more recently several selective tracers such as [11C]PE2I have been characterized and shown to be suitable as PET radioligands. Although there are a large number of serotonin transporter inhibitors used today as SSRIs, it was not until very recently, when [11C]McN5652 was synthesized, that this transporter was studied using PET. New candidates as PET radioligands for the SERT have subsequently been developed and [11C]DASB and [11C]MADAM and their analogues are today the most promising ligands. The existing radioligands for Pgp transporters seem to be suitable tools for the study of both peripheral and central drug

  11. Scintillation crystals for positron emission tomography having a non reflecting band

    International Nuclear Information System (INIS)

    This invention relates generally to positron emission tomography, a sub-field of the class of medical imaging techniques using ionizing radiation and image reconstruction techniques; and more particularly to devices which use an array of scintillation detectors to detect the annihilation radiation from positron disintegration and use this information to reconstruct an image of the distribution of positron emitting isotope within a body section. 6 figs

  12. Spatial registration of echocardiographic and positron emission tomographic heart studies

    International Nuclear Information System (INIS)

    A method has been developed to match corresponding heart regions from functional echocardiographic (Echo) and metabolic fluorine-18-fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography (PET) studies in individual patients. Echo and PET images are spatially correlated by determining homologous anatomical landmarks (the two papillary muscles and the inferior junction of the right ventricle), identifiable in images obtained by both acquisition modalities. Echo-PET image registration is first performed in the plane identified by the three landmarks, using a rigid rotate-translate scale model. The registration parameters are then used to transform the whole PET volume. This allows a consistent Echo-PET regional analysis, according to a segmental subdivision of the heart. The technique was tested on patients. The overlay of Echo and PET registered images proved the reliability of realignment of the three markers and a good spatial correlation of myocardial walls. This approach to image registration could be applied to other acquisition modalities (such as magnetic resonance imaging and single-photon emission tomography), provided that the three anatomical landmarks are visualized. (orig.)

  13. Dynamic Positron Emission Tomography Imaging of Renal Clearable Gold Nanoparticles.

    Science.gov (United States)

    Chen, Feng; Goel, Shreya; Hernandez, Reinier; Graves, Stephen A; Shi, Sixiang; Nickles, Robert J; Cai, Weibo

    2016-05-01

    Optical imaging has been the primary imaging modality for nearly all of the renal clearable nanoparticles since 2007. Due to the tissue depth penetration limitation, providing accurate organ kinetics non-invasively has long been a huge challenge. Although a more quantitative imaging technique has been developed by labeling nanoparticles with single-photon emission computed tomography (SPECT) isotopes, the low temporal resolution of SPECT still limits its potential for visualizing the rapid dynamic process of renal clearable nanoparticles in vivo. The dynamic positron emission tomography (PET) imaging of renal clearable gold (Au) nanoparticles by labeling them with copper-64 ((64) Cu) to form (64) Cu-NOTA-Au-GSH is reported. Systematic nanoparticle synthesis and characterizations are performed to demonstrate the efficient renal clearance of as-prepared nanoparticles. A rapid renal clearance of (64) Cu-NOTA-Au-GSH is observed (>75%ID at 24 h post-injection) with its elimination half-life calculated to be less than 6 min, over 130 times shorter than previously reported similar nanoparticles. Dynamic PET imaging not only addresses the current challenges in accurately and non-invasively acquiring the organ kinetics, but also potentially provides a highly useful tool for studying renal clearance mechanism of other ultra-small nanoparticles, as well as the diagnosis of kidney diseases in the near future. PMID:27062146

  14. Correlated electron-positron emission in heavy-ion collisions

    International Nuclear Information System (INIS)

    A group of narrow electron-positron sum-energy lines with similar mean energies around 610, 750 and 810 keV has been observed with the EPOS spectrometer in both collision systems 238U + 232Th and 238U + 181Ta studied so far at the UNILAC heavy ion accelerator of GSI, Darmstadt. The intensities of the three lines vary with the beam-energy, the variation being most clearly observed for the 748-keV line in 238U + 181Ta. On the basis of our present understanding Internal Pair Conversion in a collision product at rest or in flight as well as coincident lepton emission during the quasiatomic phase of the collision can be excluded as the origin. The very narrow widths of the sum-energy lines as compared to the widths of the associated broad structure in the difference spectrum of the lepton energies seem to argue for a mutual cancellation of kinematical shifts. Such correlation is expected for two leptons emitted back-to-back in a two-body decay of objects being at rest in the heavy-ion c.m. frame. This speculative hypothesis is confronted with the actual dependence of the lines on the individual lepton energy and the lepton emission angle, as well as on the opening angle of the pair. In fact, the back-to-back decay could not be proved to be a general feature of these lines. (orig.)

  15. Development of radiotracers for imaging NR2B subtype NMDA receptors with positron emission tomography

    International Nuclear Information System (INIS)

    The aim of this thesis was to develop new radioactive tracers for imaging NR2B subtype NMDA receptors with positron emission tomography. Several compounds including 4-(4-fluoro-benzyl)piperidine and presenting interesting in vivo biological properties were the object of a labelling with a positrons emitter atom (11C or 18F)

  16. The review of myocardial positron emission computed tomography and positron imaging by gamma camera

    Energy Technology Data Exchange (ETDEWEB)

    Ohtake, Tohru [Tokyo Univ. (Japan). Faculty of Medicine

    1998-04-01

    To measure myocardial blood flow, Nitrogen-13 ammonia, Oxygen-15 water, Rubidium-82 and et al. are used. Each has merit and demerit. By measuring myocardial coronary flow reserve, the decrease of flow reserve during dipyridamole in patients with hypercholesterolemia or diabetes mellitus without significant coronary stenosis was observed. The possibility of early detection of atherosclerosis was showed. As to myocardial metabolism, glucose metabolism is measured by Fluorine-18 fluorodeoxyglucose (FDG), and it is considered as useful for the evaluation of myocardial viability. We are using FDG to evaluate insulin resistance during insulin clamp in patients with diabetes mellitus by measuring glucose utilization rate of myocardium and skeletal muscle. FFA metabolism has been measured by {sup 11}C-palmitate, but absolute quantification has not been performed. Recently the method for absolute quantification was reported, and new radiopharmaceutical {sup 18}F-FTHA was reported. Oxygen metabolism has been estimated by {sup 11}C-acetate. Myocardial viability, cardiac efficiency was evaluated by oxygen metabolism. As to receptor or sympathetic nerve end, cardiac insufficiency or cardiac transplantation was evaluated. Imaging of positron emitting radiopharmaceutical by gamma camera has been performed. Collimator method is clinically useful for cardiac imaging of viability study. (author). 54 refs.

  17. The review of myocardial positron emission computed tomography and positron imaging by gamma camera

    International Nuclear Information System (INIS)

    To measure myocardial blood flow, Nitrogen-13 ammonia, Oxygen-15 water, Rubidium-82 and et al. are used. Each has merit and demerit. By measuring myocardial coronary flow reserve, the decrease of flow reserve during dipyridamole in patients with hypercholesterolemia or diabetes mellitus without significant coronary stenosis was observed. The possibility of early detection of atherosclerosis was showed. As to myocardial metabolism, glucose metabolism is measured by Fluorine-18 fluorodeoxyglucose (FDG), and it is considered as useful for the evaluation of myocardial viability. We are using FDG to evaluate insulin resistance during insulin clamp in patients with diabetes mellitus by measuring glucose utilization rate of myocardium and skeletal muscle. FFA metabolism has been measured by 11C-palmitate, but absolute quantification has not been performed. Recently the method for absolute quantification was reported, and new radiopharmaceutical 18F-FTHA was reported. Oxygen metabolism has been estimated by 11C-acetate. Myocardial viability, cardiac efficiency was evaluated by oxygen metabolism. As to receptor or sympathetic nerve end, cardiac insufficiency or cardiac transplantation was evaluated. Imaging of positron emitting radiopharmaceutical by gamma camera has been performed. Collimator method is clinically useful for cardiac imaging of viability study. (author). 54 refs

  18. Function's evaluation, perfusion and metabolism by positron emission tomography associated with multislice tomography (PET/CT) in patient with previous diagnosis to myocardial necrosis

    International Nuclear Information System (INIS)

    A 64-years-old male patient with previous diagnosis of myocardial necrosis as assessed by myocardial perfusion gated single photon emission computed tomography (gSPECT) with 3-vessel-disease, left ventricular dysfunction and symptomatic by epigastric pain. The patient was referred for myocardial viability assessment by positron emission tomography (PET) to define clinical management decision. (authors)

  19. Characterization of time resolved photodetector systems for Positron Emission Tomography

    CERN Document Server

    Powolny, François

    The main topic of this work is the study of detector systems composed of a scintillator, a photodetector and readout electronics, for Positron Emission Tomography (PET). In particular, the timing properties of such detector systems are studied. The first idea is to take advantage of the good timing properties of the NINO chip, which is a fast preamplifier-discriminator developed for the ALICE Time of flight detector at CERN. This chip uses a time over threshold technique that is to be applied for the first time in medical imaging applications. A unique feature of this technique is that it delivers both timing and energy information with a single digital pulse, the time stamp with the rising edge and the energy from the pulse width. This entails substantial simplification of the entire readout architecture of a tomograph. The scintillator chosen in the detector system is LSO. Crystals of 2x2x10mm3 were used. For the photodetector, APDs were first used, and were then replaced by SiPMs to make use of their highe...

  20. Silicon as an unconventional detector in positron emission tomography

    Science.gov (United States)

    Clinthorne, Neal; Brzezinski, Karol; Chesi, Enrico; Cochran, Eric; Grkovski, Milan; Grošičar, Borut; Honscheid, Klaus; Huh, Sam; Kagan, Harris; Lacasta, Carlos; Linhart, Vladimir; Mikuž, Marko; Smith, D. Shane; Stankova, Vera; Studen, Andrej; Weilhammer, Peter; Žontar, Dejan

    2013-01-01

    Positron emission tomography (PET) is a widely used technique in medical imaging and in studying small animal models of human disease. In the conventional approach, the 511 keV annihilation photons emitted from a patient or small animal are detected by a ring of scintillators such as LYSO read out by arrays of photodetectors. Although this has been successful in achieving ˜5 mm FWHM spatial resolution in human studies and ˜1 mm resolution in dedicated small animal instruments, there is interest in significantly improving these figures. Silicon, although its stopping power is modest for 511 keV photons, offers a number of potential advantages over more conventional approaches including the potential for high intrinsic spatial resolution in 3D. To evaluate silicon in a variety of PET "magnifying glass" configurations, an instrument was constructed that consists of an outer partial-ring of PET scintillation detectors into which various arrangements of silicon detectors are inserted to emulate dual-ring or imaging probe geometries. Measurements using the test instrument demonstrated the capability of clearly resolving point sources of 22Na having a 1.5 mm center-to-center spacing as well as the 1.2 mm rods of a 18F-filled resolution phantom. Although many challenges remain, silicon has potential to become the PET detector of choice when spatial resolution is the primary consideration.

  1. European health telematics networks for positron emission tomography

    International Nuclear Information System (INIS)

    A pilot network of positron emission tomography centers across Europe has been setup employing telemedicine services. The primary aim is to bring all PET centers in Europe (and beyond) closer, by integrating advanced medical imaging technology and health telematics networks applications into a single, easy to operate health telematics platform, which allows secure transmission of medical data via a variety of telecommunications channels and fosters the cooperation between professionals in the field. The platform runs on PCs with Windows 2000/XP and incorporates advanced techniques for image visualization, analysis and fusion. The communication between two connected workstations is based on a TCP/IP connection secured by secure socket layers and virtual private network or jabber protocols. A teleconsultation can be online (with both physicians physically present) or offline (via transmission of messages which contain image data and other information). An interface sharing protocol enables online teleconsultations even over low bandwidth connections. This initiative promotes the cooperation and improved communication between nuclear medicine professionals, offering options for second opinion and training. It permits physicians to remotely consult patient data, even if they are away from the physical examination site

  2. Diagnosis of intrahepatic cholangiocarcinoma with positron emission tomography

    International Nuclear Information System (INIS)

    Diagnosis of intrahepatic cholangiocarcinoma (IC) by positron emission tomography (PET) has been scarcely reported and this paper reviews authors' experience of PET diagnosis of IC with [18F]deoxy-glucose (FDG). Subjects are 20 cases with IC who received FDG-PET diagnosis for evaluating the disease progression and 16 cases with suspicious recurrent IC. PET was done with Advance NXi machine (GE Medical System) 60 min after intravenous 200-250 MBq of FDG. Compared were images by PET and CT. For the IC, diagnostic sensitivities by CT and PET were found to be 95-100% and for metastatic lymph nodes, the sensitivity, specificity and overall accuracy of PET were 38, 100 and 74%, respectively, whereas those of CT, 75, 73 and 74%. For recurrence, those of PET were 77, 67 and 75%. In conclusion, PET images have a compensatory role for CT images, especially for lymphatic metastasis with higher specificity and for recurrence with higher overall accuracy. (R.T.)

  3. Predicting count loss in modern positron-emission tomography systems

    International Nuclear Information System (INIS)

    The purpose of the data-acquisition electronics for any positron-emission tomography (PET) system is to detect and digitally encode annihilation events as they occur. Individual elements of the electronics are placed in parallel or cascade to organize the event information for subsequent processing. Each element is parameterized with a count loss L which is the fraction of events lost due to dead time (encoding delays, etc.) or data overflow in queueing circuits. This is an important parameter because the sensitivity of the tomograph in proportional to (1-L). The authors have categorized processing elements according to five device types. For each type, they find an expression for count loss. Some mathematical models that have appeared in the literature are applicable. These are extended here to include other devices, such as bank encoders and time-to-digital converters (TDC), with coincidence time resolving circuitry. Because some PET systems will have devices that do not fall into these categories, the authors show the derivations of the loss expressions so that one could easily extend their models with parallel derivations for other device types. In addition to PET systems, one should also be able to apply their results to other types of instruments which count random events. Although they concentrate mainly on count loss, they also briefly discuss the evaluation of other metrics of counting efficiency, which are the fraction of miscoded events and the fraction of ''random coincidence'' events

  4. European health telematics networks for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kontaxakis, George [Universidad Politecnica de Madrid, ETSI Telecomunicacion, Madrid 28040 (Spain)]. E-mail: g.kontaxakis@upm.es; Pozo, Miguel Angel [Centro PET Complutense, Madrid 28040 (Spain); Universidad Complutense de Madrid, Instituto Pluridisciplinar, Madrid 28040 (Spain); Ohl, Roland [MedCom Gesellschaft fuer medizinische Bildverarbeitung mbH, Darmstadt 64283 (Germany); Visvikis, Dimitris [U650 INSERM, Lab. du Traitement de L' Information Medicale, University of Brest Occidentale, CHU Morvan, Brest 29609 (France); Sachpazidis, Ilias [Fraunhofer Institute for Computer Graphics, Darmstadt 64283 (Germany); Ortega, Fernando [Fundacion Instituto Valenciano de Oncologia, Valencia 46009 (Spain); Guerra, Pedro [Universidad Politecnica de Madrid, ETSI Telecomunicacion, Madrid 28040 (Spain); Cheze-Le Rest, Catherine [Dept. Medicine Nucleaire, CHU Morvan, Brest 29609 (France); Selby, Peter [MedCom Gesellschaft fuer medizinische Bildverarbeitung mbH, Darmstadt 64283 (Germany); Pan, Leyun [German Cancer Research Centre, Clinical Cooperation Unit Nuclear Medicine, Heidelberg 69120 (Germany); Diaz, Javier [Fundacion Instituto Valenciano de Oncologia, Valencia 46009 (Spain); Dimitrakopoulou-Strauss, Antonia [German Cancer Research Centre, Clinical Cooperation Unit Nuclear Medicine, Heidelberg 69120 (Germany); Santos, Andres [Universidad Politecnica de Madrid, ETSI Telecomunicacion, Madrid 28040 (Spain); Strauss, Ludwig [German Cancer Research Centre, Clinical Cooperation Unit Nuclear Medicine, Heidelberg 69120 (Germany); Sakas, Georgios [MedCom Gesellschaft fuer medizinische Bildverarbeitung mbH, Darmstadt 64283 (Germany); Fraunhofer Institute for Computer Graphics, Darmstadt 64283 (Germany)

    2006-12-20

    A pilot network of positron emission tomography centers across Europe has been setup employing telemedicine services. The primary aim is to bring all PET centers in Europe (and beyond) closer, by integrating advanced medical imaging technology and health telematics networks applications into a single, easy to operate health telematics platform, which allows secure transmission of medical data via a variety of telecommunications channels and fosters the cooperation between professionals in the field. The platform runs on PCs with Windows 2000/XP and incorporates advanced techniques for image visualization, analysis and fusion. The communication between two connected workstations is based on a TCP/IP connection secured by secure socket layers and virtual private network or jabber protocols. A teleconsultation can be online (with both physicians physically present) or offline (via transmission of messages which contain image data and other information). An interface sharing protocol enables online teleconsultations even over low bandwidth connections. This initiative promotes the cooperation and improved communication between nuclear medicine professionals, offering options for second opinion and training. It permits physicians to remotely consult patient data, even if they are away from the physical examination site.

  5. Characterization of nontransmural myocardial infarction by positron-emission tomography

    International Nuclear Information System (INIS)

    The present study was performed to determine whether positron emission tomography (PET) performed after i.v. 11C-palmitate permits detection and characterization of nontransmural myocardial infarction. PET was performed after the i.v. injection of 11C-palmitate in 10 normal subjects, 24 patients with initial nontransmural myocardial infarction (defined electrocardiographically), and 22 patients with transmural infarction. Depressed accumulation of 11C-palmitate was detected with sagittal, coronal and transverse reconstructions, and quantified based on 14 contiguous transaxial reconstructions. Defects with homogeneously intense depression of accumulation of tracer were detected in all 22 patients with transmural infarction (100%). Abnormalities of the distribution of 11C-palmitate in the myocardium were detected in 23 patients with nontransmural infarction (96%). Thallium scintigrams were abnormal in only 11 of 18 patients with nontransmural infarction (61%). Tomographically estimated infarct size was greater among patients with transmural infarction (50.4 +/- 7.8 PET-g-Eq/m2 [+/- SEM SEM]) compared with those with nontransmural infarction (19 +/- 4 PET-g-Eq, p less than 0.01). Residual accumulation of 11C-palmitate within regions of infarction was more intensely depressed among patients with transmural compared to nontransmural infarction (33 +/- 1 vs 39 +/- 1% maximal myocardial radioactivity, p less than 0.01). Thus, PET and metabolic imaging with 11C-palmitate is a sensitive means of detecting, quantifying and characterizing nontransmural and transmural myocardial infarction

  6. Positron emission tomography in degenerative disorders of the dopaminergic system

    International Nuclear Information System (INIS)

    21 patients who had Parkinson's disease (PD), PD plus dementia of Alzheimer type (PDAT) or progressive supranuclear palsy (PSP), were studied with positron emission tomography (PET) using (18F)-2-fluoro-2-deoxy-D-glucose (FDG). In one patient with strictly unilateral PD side differences in striatal dopa uptake were studied with 6-(18F)fluoro-L-dopa (F-dopa). In patients with PD PET with FDG did not show any significant change in regional cerebral metabolic rates for glucose (rCMR(Glu)). In PDAT glucose metabolism was generally reduced, the most severe decrease was found in parietal cortex. The matebolic pattern was similar to that typically found in patients with Alzheimer's disease (AD). In the patients with strictly unilateral PD rCMR(Glu) was normal, F-dopa PET, however, revealed a distinct reduction of dopa uptake in the contralateral putamen. In PSP glucose metabolism was significantly decreased in subcortical regions (caudatum, putamen and brainstem) and in frontal cortex. Thus PET demonstrated a clear difference of metabolic pattern between PDAT and PSP

  7. Photon time-of-flight-assisted positron emission tomography

    International Nuclear Information System (INIS)

    In positron emission tomography (PET), the annihilation radiation is usually detected as a coincidence occurrence that localizes the position of the annihilation event to a straight line joining the detectors. The measure of the difference between the time of flight (TOF) of the annihilation photons between their inception and their detection permits the localization of the position of the annihilation event along the coincidence line. The incorporation of TOF information into the PET reconstruction process improves the signal-to-noise ratio in the image obtained. The utilization of scintillation detectors utilizing cesium fluoride scintillators, fast photomultiplier tubes, and fast timing circuits allows sub-nanosecond coincidence timing resolution needed for the effective use of TOF in PET. Mathematical considerations and pilot experiments show that with state-of-the-art electronic components and through the application of proper reconstruction algorithms, the combination of TOF and PET positional data improves severalfold the signal-to-noise ratio with respect to conventional PET image reconstruction at the cost of increasing the amount of data to be processed. The construction of a TOF-assisted PET device is within the capability of state-of-the-art technology

  8. Anaesthesia for positron emission tomography scanning of animal brains.

    Science.gov (United States)

    Alstrup, Aage Kristian Olsen; Smith, Donald F

    2013-01-01

    Positron emission tomography (PET) provides a means of studying physiological and pharmacological processes as they occur in the living brain. Mice, rats, dogs, cats, pigs and non-human primates are often used in studies using PET. They are commonly anaesthetized with ketamine, propofol or isoflurane in order to prevent them from moving during the imaging procedure. The use of anaesthesia in PET studies suffers, however, from the drawback of possibly altering central neuromolecular mechanisms. As a result, PET findings obtained in anaesthetized animals may fail to correctly represent normal properties of the awake brain. Here, we review findings of PET studies carried out either in both awake and anaesthetized animals or in animals given at least two different anaesthetics. Such studies provide a means of estimating the extent to which anaesthesia affects the outcome of PET neuroimaging in animals. While no final conclusion can be drawn concerning the 'best' general anaesthetic for PET neuroimaging in laboratory animals, such studies provide findings that can enhance an understanding of neurobiological mechanisms in the living brain. PMID:23349451

  9. European health telematics networks for positron emission tomography

    Science.gov (United States)

    Kontaxakis, George; Pozo, Miguel Angel; Ohl, Roland; Visvikis, Dimitris; Sachpazidis, Ilias; Ortega, Fernando; Guerra, Pedro; Cheze-Le Rest, Catherine; Selby, Peter; Pan, Leyun; Diaz, Javier; Dimitrakopoulou-Strauss, Antonia; Santos, Andres; Strauss, Ludwig; Sakas, Georgios

    2006-12-01

    A pilot network of positron emission tomography centers across Europe has been setup employing telemedicine services. The primary aim is to bring all PET centers in Europe (and beyond) closer, by integrating advanced medical imaging technology and health telematics networks applications into a single, easy to operate health telematics platform, which allows secure transmission of medical data via a variety of telecommunications channels and fosters the cooperation between professionals in the field. The platform runs on PCs with Windows 2000/XP and incorporates advanced techniques for image visualization, analysis and fusion. The communication between two connected workstations is based on a TCP/IP connection secured by secure socket layers and virtual private network or jabber protocols. A teleconsultation can be online (with both physicians physically present) or offline (via transmission of messages which contain image data and other information). An interface sharing protocol enables online teleconsultations even over low bandwidth connections. This initiative promotes the cooperation and improved communication between nuclear medicine professionals, offering options for second opinion and training. It permits physicians to remotely consult patient data, even if they are away from the physical examination site.

  10. Fluorodeoxyglucose positron emission tomography in pancreatic cancer: an unsolved problem

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Takashi [Dept. of Radiology, Nagoya Univ. School of Medicine (Japan); Fukatsu, Hiroshi [Dept. of Radiology, Nagoya Univ. School of Medicine (Japan); Ito, Kengo; Tadokoro, Masanori [Dept. of Radiology, Nagoya Univ. School of Medicine (Japan); Ota, Toyohiro [Dept. of Radiology, Nagoya Univ. School of Medicine (Japan); Ikeda, Mitsuru [Dept. of Medical Information and Medical Records, Nagoya Univ. School of Medicine (Japan); Isomura, Takayuki [Dept. of Radiology, Nagoya Univ. School of Medicine (Japan); Ito, Shigeki [Dept. of Radiology, Nagoya Univ. School of Medicine (Japan); Nishino, Masanari [Dept. of Radiology, Nagoya Univ. School of Medicine (Japan); Ishigaki, Takeo [Dept. of Radiology, Nagoya Univ. School of Medicine (Japan)

    1995-01-01

    The aim of this study was to examine the significance and problems of 2-[fluorine-18]-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in diagnosing pancreatic cancer and mass-forming pancreatitis (MFP). PET, X-ray computed tomography (CT) and magnetic resonance (MR) imaging were performed in 15 patients with pancreatic cancer and nine patients with MFP. The areas of the PET scan were determined according to the markers drawn on the patients at CT or MR imaging. Regions of interests (ROIs) were placed by reference to the CT or MR images corresponding to the PET images. Tissue metabolism was evaluated by the differential absorption ratio (DAR) at 50 min after intravenous injection of FDG [DAR = tissue tracer concentration/(injected dose/body weight)]. The DAR value differed significantly in pancreatic cancer (mean{+-}SD, 4.64{+-}1.94) and MFP (mean{+-}SD, 2.84{+-}2.22) (P<0.05). In one false-negative case (mucinous adenocarcinoma), the tumour contained a small number of malignant cells. In one false-positive case, lymphocytes accumulated densely in the mass in the pancreatic head. Further studies are necessary to investigate the histopathological characteristics (especially the cellularity) and other factors affecting the FDG DAR on PET images. (orig.)

  11. Cerebral perfusion reserve indexes determined by fluoromethane positron emission scanning

    International Nuclear Information System (INIS)

    An index of cerebral perfusion reserve (RES%), defined as the percent change of regional cerebral blood flow over baseline per mm Hg of end-tidal CO2 tension, was determined for each middle cerebral artery (MCA) territory in patients with unilateral carotid distribution transient ischemic attacks or minor cerebrovascular accidents and was compared with that of age-matched, neurologically normal volunteers. Vasodilator responses to induced hypercapnia were tested during inhalation of 5% CO2 in 95% O2 while regional cerebral blood flow was measured by fluoromethane inhalation positron emission tomography. Mean RES% for 24 normal MCA territories was 5.2 +/- 0.8%. Mean RES% for 15 patient nonischemic MCA territories was 3.8 +/- 1.3% and for 15 ischemic MCA territories was 2.8 +/- 1.9% (both p less than 0.001). Individual RES% values and symmetry ratios between ischemic and nonischemic regions were also determined and compared with angiographic data. Areas of diminished, asymmetric, or paradoxical (two patients) CO2 reactivity appear to correspond to areas of compensatory vasodilation. We found this technique to be a safe and reproducible method for defining and recording localized areas of cerebral tissue at apparent risk for hemodynamically related damage

  12. Positron emission tomography in degenerative disorders of the dopaminergic system

    International Nuclear Information System (INIS)

    21 patients who had Parkinson's disease (PD), PD plus dementia of Alzheimer type (PDAT) or progressive supranuclear palsy (PSP), were studied with positron emission tomography (PET) using (18F)-2-fluoro-2-deoxy-D-glucose (FDG). In one patient with strictly unilateral PD side differences in striatal dopa uptake were studied with 6-(18F)fluoro-L-dopa (F-dopa). In patients with PD PET with FDG did not show any significant change in regional cerebral metabolic rates for glucose (rCMR(Glu)). In PDAT glucose metabolism was generally reduced, the most severe decrease was found in parietal cortex. The metabolic pattern was similar to that typically found in patients with Alzheimer's disease (AD). In the patient with strictly unilateral PD rCMR(Glu) was normal, F-dopa PET, however, revealed a distinct reduction of dopa uptake in the contralateral putamen. In PSP glucose metabolism was significantly decreased in subcortical regions (caudatum, putamen and brainstem) and in frontal cortex. Thus PET demonstrated a clear difference of metabolic pattern between PDAT and PSP. (authors)

  13. Measurement of regional cerebral blood flow by positron emission tomography

    International Nuclear Information System (INIS)

    The principal advantage of positron emission tomography over other methods for measuring cerebral blood flow stems from the accurate, quantitative three-dimensional measurements of regional brain radioactivity that are possible with this technique. As a result, accurate quantitative measurements of regional cerebral blood flow can be obtained for both superficial and deep cerebral structures. The value of PET for investigating central nervous system physiology and pathology extends far beyond this, however. Through the use of different radiotracers and appropriate mathematical models, PET can be applied to the measurement of a wide variety of physiologic variables. Measurements of rCBF tell only part of the story. Experience with PET and with a variety of other techniques has taught us that rCBF is at times a poor indicator of the metabolic, functional, and biochemical status of cerebral tissue. It is only by understanding the interaction of all of these factors that our understanding of neurologic disease can advance. It is in the investigation of these complex relationships that the real value of PET resides

  14. 76 FR 47593 - Guidance for Small Business Entities on Current Good Manufacturing Practice for Positron Emission...

    Science.gov (United States)

    2011-08-05

    ... a guidance for small business entities entitled ``PET Drugs--Current Good Manufacturing Practice... entitled ``PET Drugs--Current Good Manufacturing Practice (CGMP); Small Entity Compliance Guide.'' This... Manufacturing Practice for Positron Emission Tomography Drugs; Availability AGENCY: Food and Drug...

  15. Diagnostic value for extrahepatic metastases of hepatocellular carcinoma in positron emission tomography/computed tomography scan

    OpenAIRE

    2012-01-01

    AIM: To evaluated the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan in diagnosis of hepatocellular carcinoma (HCC) and extrahepatic metastases.

  16. Molecular pathology in vulnerable carotid plaques: correlation with [18]-fluorodeoxyglucose positron emission tomography (FDG-PET)

    DEFF Research Database (Denmark)

    Graebe, M; Pedersen, Sune Folke; Borgwardt, L;

    2008-01-01

    OBJECTIVES: Atherosclerosis is recognised as an inflammatory disease, and new diagnostic tools are warranted to evaluate plaque inflammatory activity and risk of cardiovascular events. We investigated [18]-fluorodeoxyglucose (FDG) uptake in vulnerable carotid plaques visualised by positron emission...

  17. Measurement of regional cerebral glucose utilization in man by positron emission tomography

    International Nuclear Information System (INIS)

    The various methods available for the study of regional cerebral glucose consumption in man by positron emission tomography are described and their applications, limitations and principal physiopathological results are presented

  18. Synthesis of the radiopharmaceuticals for positron emission tomography

    International Nuclear Information System (INIS)

    In this paper is shown a short overview of the biogenic positron radiopharmaceuticals production and a brief summary of some PET preparation synthesis. At the end the overview of some forward-looking positron radionuclides, which can be used for a preparation of the PET radiopharmaceuticals is said. A short review of diagnostic use of PET radiopharmaceuticals is presented (authors)

  19. Positron emission tomography with [{sup 18}F]FDG for therapy response monitoring in lymphoma patients

    Energy Technology Data Exchange (ETDEWEB)

    Spaepen, Karoline; Stroobants, Sigrid; Mortelmans, Luc [Department of Nuclear Medicine, UZ Gasthuisberg, Herestraat 49, 3000, Leuven (Belgium); Verhoef, Gregor [Department of Hematology, UZ Gasthuisberg, Herestraat 49, 3000, Leuven (Belgium)

    2003-06-01

    Lymphomas are a heterogeneous group of diseases with differing histopathology, clinical behaviour, response to therapy and outcome. Lymphomas are highly sensitive to chemotherapy and radiotherapy, and the recent developments in treatment have considerably improved clinical outcome. However, there is increasing recognition that this has been at the cost of long-term treatment-related effects in a relatively young patient population. Thus, one of the most challenging aspects in the imaging of lymphoma patients is tailoring the intensity of the treatment to the individual patient. This paper reviews recently published data concerning the use of fluorine-18 fluorodeoxyglucose positron emission tomography ([{sup 18}F]FDG-PET) for therapy monitoring in lymphoma patients and highlights the shortcomings and future directions. A temporary strategy for the implementation of [{sup 18}F]FDG-PET in the management of lymphoma patients is proposed. (orig.)

  20. Imaging prostate cancer: an update on positron emission tomography and magnetic resonance imaging

    DEFF Research Database (Denmark)

    Bouchelouche, Kirsten; Turkbey, Baris; Choyke, Peter;

    2010-01-01

    molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI......Prostate cancer is a common cancer in men and continues to be a major health problem. Imaging plays an essential role in the clinical management of patients. An important goal for prostate cancer imaging is more accurate disease characterization through the synthesis of anatomic, functional, and....../CT imaging of prostate cancer. Among these, choline (labeled with (18)F or (11)C), (11)C-acetate, and (18)F-fluoride have demonstrated promising results, and other new radiopharmaceuticals are currently under evaluation in preclinical and clinical studies....

  1. Imaging prostate cancer: an update on positron emission tomography and magnetic resonance imaging

    DEFF Research Database (Denmark)

    Bouchelouche, Kirsten; Turkbey, Baris; Choyke, Peter;

    2010-01-01

    Prostate cancer is a common cancer in men and continues to be a major health problem. Imaging plays an essential role in the clinical management of patients. An important goal for prostate cancer imaging is more accurate disease characterization through the synthesis of anatomic, functional, and...... molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI....../CT imaging of prostate cancer. Among these, choline (labeled with (18)F or (11)C), (11)C-acetate, and (18)F-fluoride have demonstrated promising results, and other new radiopharmaceuticals are currently under evaluation in preclinical and clinical studies....

  2. A Practical One-Pot Synthesis of Positron Emission Tomography (PET) Tracers via Nickel-Mediated Radiofluorination

    OpenAIRE

    Zlatopolskiy, Boris D; Zischler, Johannes; Urusova, Elizaveta A; Endepols, Heike; Kordys, Elena; Frauendorf, Holm; Mottaghy, Felix M; Neumaier, Bernd

    2015-01-01

    Invited for this months cover picture is the group of Professor Bernd Neumaier at the Institute of Radiochemistry and Experimental Molecular Imaging at the University Clinic of Cologne. The cover picture shows the differences in brain metabolism of a healthy young and a healthy old subject, as well as a patient suffering from Parkinsons disease (left to right) uncovered by 6-[18F]FDOPA-positron emission tomography (PET). Morbus Parkinson occurs when nerve cells that produce dopamine begin to ...

  3. Characteristics of glucose metabolism and amyloid deposition by positron emission tomography images in Alzheimer’s disease

    Institute of Scientific and Technical Information of China (English)

    纪勇

    2013-01-01

    Objective To investigate positron emission tomography (PET) image characteristics of glucose metabolism and amyloid deposition as demonstrated by fluorodeoxyglucose (18F-FDG) and Pittsburgh Compound B (PiB) in Alzheimer’s disease (AD) .Methods Patients with mild AD and moderate AD (n=6,each) were included in this study.6 healthy subjects were selected as normal controls.Cognitive function was assessed by the minimental state examination,Montreal Cognitive Assessment and Clinical Dementia Rating.Ventricular dilation,cor-

  4. F-18 fluoro-d-glucose positron emission tomography/computed tomography in a patient with corticobasal degeneration.

    Science.gov (United States)

    Marti, Alejandro

    2015-01-01

    Corticobasal degeneration is a rare neurodegenerative disorder that often eludes clinical diagnosis. The present case shows the F-18 fluoro-d-glucose positron emission tomography/computed tomography (PET/CT) of a 62-year-old man with a progressive movement disorder with asymmetric features. PET/CT examination showed a markedly right-brain hemispheric hypometabolism also involving basal ganglia. PMID:25829747

  5. Striatal [11C]-N-methyl-spiperone binding in patients with focal dystonia (torticollis) using positron emission tomography

    International Nuclear Information System (INIS)

    Specific binding of [11C]-N-methyl-spiperone to striatal dopamine D2 receptors was assessed using positron emission tomography (PET) in 6 patients with adult-onset focal dystonia (predominantly spasmodic torticollis) and in 5 healthy subjects. No significant difference in average specific striatal tracer uptake between patients and healthy subjects was found. However, in the 5 patients showing lateralisation of clinical signs a trend to higher striatal tracer uptake in the contralateral hemisphere was observed. (authors)

  6. What have positron emission tomography and ‘Zippy’ told us about the neuropharmacology of drug addiction?

    OpenAIRE

    Cumming, Paul; Caprioli, Daniele; Dalley, Jeffrey W.

    2011-01-01

    Translational molecular imaging with positron emission tomography (PET) and allied technologies offer unrivalled applications in the discovery of biomarkers and aetiological mechanisms relevant to human disease. Foremost among clinical PET findings during the past two decades of addiction research is the seminal discovery of reduced dopamine D2/3 receptor expression in the striatum of drug addicts, which could indicate a predisposing factor and/or compensatory reaction to the chronic abuse of...

  7. Catecholamine stimulation, substrate competition, and myocardial glucose uptake in conscious dogs assessed with positron emission tomography

    International Nuclear Information System (INIS)

    Uptake of radiolabelled deoxyglucose out of proportion to reduced coronary flow demonstrated by positron emission tomography has been used to identify reversibly ischemic, viable myocardium. For this concept to be applied reliably in the clinical setting, factors that may depress glucose availability independent of tissue viability, such as adrenergic stimulation and substrate competition, must be examined. Accordingly, we studied the effect of catecholamine stimulation by dopamine on myocardial glucose uptake in vivo using chronically instrumented, intact dogs and positron emission tomography. We measured myocardial activity of [2-18F]-2-deoxyglucose (FDG) and 82Rb in glucose-loaded animals randomly studied during dopamine infusion, during insulin infusion, and then during their combined infusion. Myocardial FDG uptake was significantly decreased when animals were treated with dopamine, compared with treatment in the same animals with insulin. When insulin was added to the dopamine infusion, myocardial FDG uptake was restored. In contrast, myocardial activity of 82Rb, which is taken up in proportion to coronary flow, was similar under all three experimental conditions. Plasma glucose, free fatty acid, and lactate concentrations were determined before and during each infusion. The depression of myocardial FDG activity seen during dopamine infusion and its reversal with addition of insulin can be explained on the basis of effects of these hormones on substrate availability and competition

  8. Diagnostic utility of fluorodeoxyglucose positron emission tomography/computed tomography in pyrexia of unknown origin

    International Nuclear Information System (INIS)

    The present study was undertaken to evaluate the diagnostic utility of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in patients presenting as pyrexia of unknown origin (PUO). Forty-seven patients (31 males and 16 females; mean age of 42.7 ± 19.96 years) presenting as PUO to the Department of Medicine at the All India Institute of Medical Sciences, New Delhi over a period of 2 years underwent F-18 FDG PET/CT. PET ⁄ CT was considered supportive when its results correlated with the final definitive diagnosis. Final diagnosis was made on the basis of combined evaluation of history, clinical findings, investigations, and response to treatment. Thirty-five PET/CT studies (74.5%) were positive. However, only 18 (38.3%) were supportive of the final diagnosis. In three patients (6.4%), PET/CT was considered diagnostic as none of the other investigations including contrast-enhanced computed tomography of chest and abdomen, and directed tissue sampling could lead to the final diagnosis. All these three patients were diagnosed as aortoarteritis. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography is an important emerging modality in the workup of PUO. It supported the final diagnosis in 38% of our patients and was diagnostic in 6.4% of patients. Thus, PET/CT should only be considered as second-line investigation for the diagnostic evaluation of PUO; especially in suspected noninfectious inflammatory disorders

  9. Silicon as an unconventional detector in positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a widely used technique in medical imaging and in studying small animal models of human disease. In the conventional approach, the 511 keV annihilation photons emitted from a patient or small animal are detected by a ring of scintillators such as LYSO read out by arrays of photodetectors. Although this has been successful in achieving ∼5mm FWHM spatial resolution in human studies and ∼1mm resolution in dedicated small animal instruments, there is interest in significantly improving these figures. Silicon, although its stopping power is modest for 511 keV photons, offers a number of potential advantages over more conventional approaches including the potential for high intrinsic spatial resolution in 3D. To evaluate silicon in a variety of PET “magnifying glass” configurations, an instrument was constructed that consists of an outer partial-ring of PET scintillation detectors into which various arrangements of silicon detectors are inserted to emulate dual-ring or imaging probe geometries. Measurements using the test instrument demonstrated the capability of clearly resolving point sources of 22Na having a 1.5 mm center-to-center spacing as well as the 1.2 mm rods of a 18F-filled resolution phantom. Although many challenges remain, silicon has potential to become the PET detector of choice when spatial resolution is the primary consideration. -- Highlights: ► We examine the use of position-sensitive silicon detectors in magnifying PET geometries. ► A demonstrator using silicon detectors and BGO scintillation detectors was constructed. ► Both single-slice and volume PET configurations were tested. ► For a 4.5 cm field-of-view, resolutions <1mm were achievable. ► Resolution will improve further with higher resolution silicon detectors.

  10. Positron emission tomography in patients with drug-resistant epilepsy

    International Nuclear Information System (INIS)

    Positron emission tomography with 18Fluor-deoxyglucose (18FDG PET) was introduced as method of evaluation of the cerebral metabolism in the early 80s. 18FDG PET/computed tomography (PET/CT) has rapidly become a method of epileptogenic zone localization because of the hypometaboilsm of this zone during the interictal period. This paper represents the first Bulgarian series of patients with drug- resistant epilepsy who were evaluated with 18FDG PET as part of the presurgical work-up. Our study has included 21 patients with drug-resistant epilepsy who were evaluated with 18FDG PET/CT from January 2010 to May 2013. All patients were evaluated with dedicated MRI epilepsy protocol. PET/CT study was fused with 3D MRI study using FSL or GE software. Video EEG monitoring was performed in all 21 patients and seizures were recorded in 18 patients. Hypometabolic zones were found in 15 patients. The hypometabolism was focal in 5 patients, multilobar in 9 patients and hemispheric in 1 patient. The MRI was normal in 8 patients. Hypometabolic zones were found in 3 of these 8 patients with cryptogenic epilepsy. Epilepsy surgery was performed in 6 cases. All operated patients were with hypometabolic zones. Significant seizure reduction after surgery was observed in 5 of 6 operated patients. 18FDG PET/CT is a valuable method for epileptogenic zone localization in patients with drug-resistant epilepsy. The introduction of this method in the bulgarian epilepsy surgery program increases the chances for successful resective surgery. (authors)

  11. Positron emission tomography in urological cancer; Positronenemissionstomographie bei urologischen Tumoren

    Energy Technology Data Exchange (ETDEWEB)

    Wit, M. de [Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Abt. Onkologie/Haematologie, Medizinische Klinik; Kotzerke, J. [Universitaetsklinikum Ulm (DE). Radiologie III (Nuklearmedizin)

    2000-09-01

    In staging cancer of the urinary bladder, the kidneys and the prostate and of testicular cancer there is a need for detecting tumor involvement of the lymph nodes to avoid surgical exploration. Positron emission tomography (PET) using fluorodeoxyglucose (FDG) can detect tumorous lymph nodes (sensitivity: 70%, specificity: 85%) which is helpful for several patients. In carcinoma of the prostate, other radiotracers than FDG (e.g. C-11-choline) might be more sensitive to detect tumorous lymph nodes. Up to now no diagnostical benefit of PET in germ cell tumors could be demonstrated in the published small series. In principle FDG-PET is useful in diagnosis of recurrence. In germ cell cancer FDG-PET seems to identify effectively persistent vital tumor tissue after chemotherapy. A multicenter study was initiated to demonstrate the potential of FDG-PET in a sufficient number of patients with germ cell tumor. (orig.) [German] Bei Harnblasen-, Nieren-, Prostata- und Hodenkarzinomen besteht aus klinischer Sicht ein Bedarf an verbessertem Lymphknoten-Staging, um die operative Evaluation zu vermeiden. Die Positronenemissionstomographie (PET) mit Fluordeoxyglukose (FDG) kann daher im Einzelfall bei Harnblasen- und Nierenkarzinomen hilfreich sein (bei Sensitivitaet um 70% und Spezifitaet um 85%). Beim Prostatakarzinom koennten sich andere Radiotracer (z.B. C-11-Cholin) bei der Detektion von tumoroesen Lymphknoten ueberlegen erweisen. Bei Keimzelltumoren konnte ein Nutzen der PET im primaeren Staging bei den bisher publizierten kleinen Studien nicht nachgewiesen werden. Fuer die Rezidivdiagnostik ist bei den genannten Tumoren aus grundsaetzlicher Ueberlegung der Einsatz von DFG-PET sinnvoll. Die Erkennung von vitalem malignen Tumorgewebe nach Chemotherapie erscheint bei Keimzelltumoren mit FDG-PET weitgehend sicher zu gelingen. Eine multizentrische Studie wurde begonnen, die hierueber Aufschluss geben wird. (orig.)

  12. Noninvasive alternatives to arterial blood sampling in positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography is commonly employed for the quantitative assessment of regional biochemistry. The determination of glucose and oxygen utilization rates using [F-18] 2FDG and [0-15] 0/sub 2/ demand accurate measurement of the driving function producing the observed tissue response. Conventional techniques consist of an arterial or venous puncture with either discrete or continuous sampling of blood label concentrations. A time-of-flight (TOF) probe and expired gas detector have been developed as alternatives to these invasive techniques. The acquisition of serial spectra with the TOF pair (4 x 4cm BaF/sub 2/;XP2020Q;380 psec FWHM), sampling a line through the cardiac chambers, reveals the spatial distribution of activity in the heart and surrounding tissue as a function of time. Region-of-interest analysis of the temporally resolved spectra produce the activity time courses required for analysis of tissue response data. Multigated TOF acquisition using a pulsewatch (LED-phototransistor pair which detects finger-tip blood volume changes) as the gating mechanism promises to provide an easy and accurate method for positioning the TOF probe. Dynamic techniques for the measurement of oxygen utilization rates require both the arterial [0-15] 0/sub 2/ and [0-15] H/sub 2/O concentrations. A heated flow-through plastic (NE 102) beta detector was developed to measure the concentration of label in the alveolar gas which was equilibrated with the blood in the pulmonary capillaries. Combining the TOF probe and expired gas data allows the separation of the oxygen and water components of the input function

  13. Analysis of Factors Affecting Positron Emission Mammography (PEM) Image Formation

    International Nuclear Information System (INIS)

    Image reconstruction for positron emission mammography (PEM) with the breast positioned between two parallel, planar detectors is usually performed by backprojection to image planes. Three important factors affecting PEM image reconstruction by backprojection are investigated: (1) image uniformity (flood) corrections, (2) image sampling (pixel size) and (3) count allocation methods. An analytic expression for uniformity correction is developed that incorporates factors for spatial-dependent detector sensitivity and geometric effects from acceptance angle limits on coincidence events. There is good agreement between experimental floods from a PEM system with a pixellated detector and numerical simulations. The analytic uniformity corrections are successfully applied to image reconstruction of compressed breast phantoms and reduce the necessity for flood scans at different image planes. Experimental and simulated compressed breast phantom studies show that lesion contrast is improved when the image pixel size is half of, rather than equal to, the detector pixel size, though this occurs at the expense of some additional image noise. In PEM reconstruction counts usually are allocated to the pixel in the image plane intersected by the line of response (LOR) between the centers of the detection pixels. An alternate count allocation method is investigated that distributes counts to image pixels in proportion to the area of the tube of response (TOR) connecting the detection pixels that they overlay in the image plane. This TOR method eliminates some image artifacts that occur with the LOR method and increases tumor signal-to-noise ratios at the expense of a slight decrease in tumor contrast. Analysis of image uniformity, image sampling and count allocation methods in PEM image reconstruction points to ways of improving image formation. Further work is required to optimize image reconstruction parameters for particular detection or quantitation tasks

  14. Study of brain metabolism using positron emission computed tomography

    International Nuclear Information System (INIS)

    Positron emission tomography permits the three-dimensional regional measurement of metabolism and blood flow in the brain. For the determination of cerebral metabolic rates of glucose by PET 18fluordeoxyglucose is usually applied: cerebral metabolic rate of glucose was found to be 36 to 47 μmol/100 g/min in the grey matter and 23 to 29 μmol/100 g/min in the white matter of normal volunteers. During physiologic activation metabolic rate of glucose is increased in the respective brain areas in relation to the strength and complexity of the stimulation. In patients suffering from ischaemic stroke glucose metabolism is markedly decreased within the infarction. Additonally, glucose metabolism is reduced by 20% in morphologically intact areas of the homolateral cortex, in the basal ganglia, in the cortical area contralateral to the infarction and in the contralateral cerebellum. This remote reduction of glucose utilization is probably caused by functional inactivation of these brain structures; it could be responsible for the diffuse organic syndrome in stroke victims not caused by the focal lesion. In patients suffering from dementia of the multi-infarct type and of the Alzheimer type glucose metabolism is reduced; the lesions in Alzheimer cases are most prominent in partietal and frontal cortical areas. In Chorea Huntington cases glucose metabolism is primarily disturbed in the striate, especially in the caudate nucleus; in these cases the metabolic disturbance can be detected earlier than the atrophy in computed tomograms. Disturbances of glucose and oxygen utilization are not necessary causes, but may also be sequelae od functional impairment. Additional information on pathogentic mechanisms may be obtained by the investigation of the protein synthesis. (orig.)

  15. Effect of tissue heterogeneity on quantification in positron emission tomography

    International Nuclear Information System (INIS)

    As a result of the limited spatial resolution of positron emission tomographic scanners, the measurements of physiological parameters are compromised by tissue heterogeneity. The effect of tissue heterogeneity on a number of parameters was studied by simulation and an analytical method. Five common tracer models were assessed. The input and tissue response functions were assumed to be free from noise and systematic errors. The kinetic model was assumed to be perfect. Two components with different kinetics were mixed in different proportions and contrast with respect to the model parameters. Different experimental protocols were investigated. Of three methods investigated for the measurement of cerebral blood flow (CBF) (steady state, dynamic, integral), the second one was least sensitive to errors caused by tissue heterogeneity and the main effect was an underestimation of the distribution volume. With the steady state method, errors in oxygen extraction fraction caused by tissue heterogeneity were always found to be less than the corresponding errors in CBF. For myocardial blood flow the steady state method was found to perform better than the bolus method. The net accumulation of substrate (i.e. rCMRglc in the case of glucose analogs) was found to be comparatively insensitive to tissue heterogeneity. Individual rate constans such as k2 and k3 for efflux and metabolism of the substrate in the pool of unmetabolized substrate in the tissue, respectively, were found to be more sensitive. In studies of radioligand binding, using only tracer doses, the effect of tissue heterogeneity on the parameter kon.Bmax could be considerable. In studies of radioligand binding using a protocol with two experiments, one with high and one with low specific activity, Bmax was found to be insensitive while Kd was very sensitive to tissue heterogeneity. (orig.)

  16. Effect of tissue heterogeneity on quantification in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Blomqvist, G. [Dept. of Clinical Neuroscience, Experimental Alcohol and Drug Addiction Research Section, Karolinska Hospital, Stockholm (Sweden); Lammertsma, A.A. [PET Methodology Group, Cyclotron Unit, MRC Clinical Sciences Centre, Royal Postgraduate Medical School, Hammersmith Hospital, London (United Kingdom); Mazoyer, B. [Service Hospitalier Frederic Joliot CEA/Dept. de Biologie, Hopital d`Orsay and Antenne d`Informatique Medicale, Hopital Robert Debre, Paris (France); Wienhard, K. [Max-Planck-Inst. fuer Neurologische Forschung, Koeln (Germany)

    1995-07-01

    As a result of the limited spatial resolution of positron emission tomographic scanners, the measurements of physiological parameters are compromised by tissue heterogeneity. The effect of tissue heterogeneity on a number of parameters was studied by simulation and an analytical method. Five common tracer models were assessed. The input and tissue response functions were assumed to be free from noise and systematic errors. The kinetic model was assumed to be perfect. Two components with different kinetics were mixed in different proportions and contrast with respect to the model parameters. Different experimental protocols were investigated. Of three methods investigated for the measurement of cerebral blood flow (CBF) (steady state, dynamic, integral), the second one was least sensitive to errors caused by tissue heterogeneity and the main effect was an underestimation of the distribution volume. With the steady state method, errors in oxygen extraction fraction caused by tissue heterogeneity were always found to be less than the corresponding errors in CBF. For myocardial blood flow the steady state method was found to perform better than the bolus method. The net accumulation of substrate (i.e. rCMR{sub glc} in the case of glucose analogs) was found to be comparatively insensitive to tissue heterogeneity. Individual rate constans such as k{sub 2} and k{sub 3} for efflux and metabolism of the substrate in the pool of unmetabolized substrate in the tissue, respectively, were found to be more sensitive. In studies of radioligand binding, using only tracer doses, the effect of tissue heterogeneity on the parameter k{sub on}.B{sub max} could be considerable. In studies of radioligand binding using a protocol with two experiments, one with high and one with low specific activity, B{sub max} was found to be insensitive while K{sub d} was very sensitive to tissue heterogeneity. (orig.)

  17. 18F-fluorodeoxyglucose positron emission tomography imaging in brain tumours : The Western Australia positron emission tomography/cyclotron service experience

    International Nuclear Information System (INIS)

    Full text: 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans in the first 49 patients referred with either possible brain tumour or brain tumour recurrence were reviewed. FDG-PET imaging was reported with reference to anatomical imaging. Based on the report the FDG study was classified as either positive or negative for the presence of tumour. Thirty-eight cases were included in the analysis, 21 having pathological data and 17 with diagnostic clinical follow up. Eleven were excluded, as they had inadequate follow-up data. Of the 21 cases with pathology, 18 were shown to have tumour. In this group there were five false-negative scans and two false-positive PET scans. Seventeen cases were assessed by clinical follow up, nine were considered to have been tumour. There were two false negatives with one false positive. The overall sensitivity, specificity and positive and negative predictive values were 74, 73, 87 and 53% respectively. This is similar to figures previously quoted in published work. Despite relatively limited numbers, the utility of FDG PET imaging in our hands is similar to published reports. With a positive predictive value of 87%, a positive FDG study indicates a high likelihood that there is brain tumour present. A negative study does not exclude the presence of tumour

  18. Development of EndoTOFPET-US, a multi-modal endoscope for ultrasound and time of flight positron emission tomography

    International Nuclear Information System (INIS)

    The EndoTOFPET-US project aims at delevoping a multi-modal imaging device that combines Ultrasound with Time-Of-Flight Positron Emission Tomography into an endoscopic imaging device. The goal is to obtain a coincidence time resolution of about 200 ps FWHM and sub-millimetric spatial resolution for the PET head, integrating the components in a very compact detector suitable for endoscopic use. The scanner will be exploited for the clinical test of new bio-markers especially targeted for prostate and pancreatic cancer as well as for diagnostic and surgical oncology. This paper focuses on the status of the Time-Of-Flight Positron Emission Tomograph under development for the EndoTOFPET-US project

  19. Basal ganglia disorders studied by positron emission tomography

    International Nuclear Information System (INIS)

    Recent development of positron emitting radioligands has made it possible to investigate the alterations of neurotransmitter systems associated with basal ganglia disorders in vivo. The functional integrity of nigro-striatal dopaminergic terminals may be studied with [18F]6-fluoro-L-dopa ([18F]dopa), and striatal dopamine receptor density with suitable PET ligands. [18F]dopa uptake in the striatum (putamen) is markedly reduced in patients with Parkinson's disease (PD). [18F]dopa-PET is capable of detecting sub-clinical nigral dysfunction in asymptomatic patients with familial PD and those who become Parkinsonian on conventional doses of dopamine receptor antagonists. While putamen [18F]dopa uptake is reduced to a similar level in patients with multiple system atrophy (MSA) and PD, caudate [18F] dopa uptake is lower in MSA than PD. However, [18F]dopa PET cannot consistently distinguish MSA from PD because individual ranges of caudate [18F]dopa uptake overlap. D1 and D2 receptor binding is markedly reduced in the striatum (posterior putamen) of MSA patients. Therefore, dopamine receptor imaging is useful for the differential diagnosis of MSA and PD. Similar marked reductions in putamen and caudate [18F]dopa uptake have been observed in patients with progressive supranuclear palsy (PSP). Moderate reductions in D2 receptor binding have been reported in the striatum of PSP patients. The reduction in D2 receptor binding is more prominent in the caudate than putamen. Striatal [18F]dopa uptake is normal or only mildly reduced in patients with dopa responsive dystonia (DRD). D2 receptor binding is markedly reduced in patients with Huntington's disease, while striatal [18F]dopa uptake is normal or mildly reduced. In summary, PET can demonstrate characteristic patterns of disruption of dopaminergic systems associated with basal ganglia disorders. These PET findings are useful in the differential diagnosis of basal ganglia disorders. (J.P.N.) 55 refs

  20. Positron emission tomography displacement sensitivity: predicting binding potential change for positron emission tomography tracers based on their kinetic characteristics.

    Science.gov (United States)

    Morris, Evan D; Yoder, Karmen K

    2007-03-01

    There is great interest in positron emission tomography (PET) as a noninvasive assay of fluctuations in synaptic neurotransmitter levels, but questions remain regarding the optimal choice of tracer for such a task. A mathematical method is proposed for predicting the utility of any PET tracer as a detector of changes in the concentration of an endogenous competitor via displacement of the tracer (a.k.a., its 'vulnerability' to competition). The method is based on earlier theoretical work by Endres and Carson and by the authors. A tracer-specific predictor, the PET Displacement Sensitivity (PDS), is calculated from compartmental model simulations of the uptake and retention of dopaminergic radiotracers in the presence of transient elevations of dopamine (DA). The PDS predicts the change in binding potential (DeltaBP) for a given change in receptor occupancy because of binding by the endogenous competitor. Simulations were performed using estimates of tracer kinetic parameters derived from the literature. For D(2)/D(3) tracers, the calculated PDS indices suggest a rank order for sensitivity to displacement by DA as follows: raclopride (highest sensitivity), followed by fallypride, FESP, FLB, NMSP, and epidepride (lowest). Although the PDS takes into account the affinity constant for the tracer at the binding site, its predictive value cannot be matched by either a single equilibrium constant, or by any one rate constant of the model. Values for DeltaBP have been derived from published studies that employed comparable displacement paradigms with amphetamine and a D(2)/D(3) tracer. The values are in good agreement with the PDS-predicted rank order of sensitivity to displacement. PMID:16788713

  1. Attenuation correction with Region Growing Method used in the Positron Emission Mammography System

    CERN Document Server

    Gu, Xiao-Yue; Yin, Peng-Fei; Yun, Ming-Kai; Pei, Chai; Fan, Xin; Huang, Xian-Chao; Sun, Xiao-Li; Wei, Long

    2014-01-01

    Positron Emission Mammography imaging system (PEMi) is a nuclear medicine diagnosis method dedicated for breast imaging. It provides a better resolution in detection of millimeter-sized breast tumors than whole-body PET. To address the requirement of semi-quantitative analysis with the radiotracer concentration map of the breast, a new attenuation correction method based on three-dimensional seeded region growing image segmentation (3DSRG-AC) solution was developed. The method gives a 3D connected region as the segmentation result instead of image slices. The continuously segmentation property makes this new method free of activity variation of breast tissues. Threshold value chosen is the key point for the segmentation process. The first valley of the grey level histogram of the reconstruction image is set as the lower threshold, which works fine in clinical application. Results show that attenuation correction for PEMi improves the image quality and the quantitative accuracy of radioactivity distribution de...

  2. Dose absorbed by technologists in positron emission tomography procedures with FDG

    International Nuclear Information System (INIS)

    The objective of this work was to evaluate radiation doses delivered to technologists engaged in different tasks involving positron emission tomography (PET) studies with FDG (fluorodeoxyglucose). This investigation was performed in two French nuclear medicine departments, which presented significant differences in their arrangements and radiation safety conditions. Both centers administered about 300 MBq per PET/CT study, although only one of them is a dedicated clinical PET center. Dose equivalent Hp(10) and skin dose Hp(0.07) were measured using Siemens electronic personnel dosimeters. For assessment dose absorbed by hands during drawing up of tracer and injection into the patient, a Polimaster wristwatch gamma dosimeter was employed. Absorbed dose and the time spent during each investigated task were recorded for a total of 180 whole-body PET studies. In this report, the methodology employed, the results and their radioprotection issues are presented as well as discussed. (author)

  3. Imaging Atherosclerosis with Hybrid Positron Emission Tomography/Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Ripa, Rasmus Sejersten; Kjær, Andreas

    2015-01-01

    Noninvasive imaging of atherosclerosis could potentially move patient management towards individualized triage, treatment, and followup. The newly introduced combined positron emission tomography (PET) and magnetic resonance imaging (MRI) system could emerge as a key player in this context. Both...... PET and MRI have previously been used for imaging plaque morphology and function: however, the combination of the two methods may offer new synergistic opportunities. Here, we will give a short summary of current relevant clinical applications of PET and MRI in the setting of atherosclerosis....... Additionally, our initial experiences with simultaneous PET/MRI for atherosclerosis imaging are presented. Finally, future potential vascular applications exploiting the unique combination of PET and MRI will be discussed....

  4. A Haar-wavelet-based Lucy-Richardson algorithm for positron emission tomography image restoration

    International Nuclear Information System (INIS)

    Deconvolution is an ill-posed problem that requires regularization. Noise would inevitably be enhanced during the iterative deconvolution process. The enhanced noise degrades the image quality, causing mistakes in clinical interpretations. This paper introduced a Haar-wavelet-based Lucy-Richardson algorithm (HALU) for positron emission tomography (PET) image restoration based on a spatially variant point spread function. After wavelet decomposition, Lucy-Richardson algorithm was applied to each approximation matrix with different iteration numbers. Thus, this enhanced the contrasts of our images without amplifying much of the noise level. The results showed that HALU can be able to recover the resolution and yield better contrast and lower noise level than the Lucy-Richardson algorithm.

  5. Positron emission tomography/computed tomography in the diagnosis of inflammatory processes

    International Nuclear Information System (INIS)

    The hybrid imaging modality known as PET/CT is being continuously introduced as a method of choice in the diagnostics of numerous inflammatory processes. The dual - computer tomography/positron emission tomography -investigation has advantages over other imaging modalities, mainly because of its ability to provide both morphological and functional information - combined in a whole body scan. Most of the inflammatory processes require on-time, accurate diagnostics and an imaging method that can provide therapy monitoring. The purpose of the following literature review is to compare the clinical application of PET/CT to other imaging modalities investigating inflammatory processes and to show its important role in the diagnostic algorithm and follow up of many inflammatory processes such as fever of unknown origin, osteomyelitis, inflammation of vascular prostheses etc. (authors) Key words: 18F-FDG PET/CT. DIAGNOSTIC IMAGING. INFLAMMATORY DISEASES

  6. An objective evaluation framework for segmentation techniques of functional positron emission tomography studies

    CERN Document Server

    Kim, J; Eberl, S; Feng, D

    2004-01-01

    Segmentation of multi-dimensional functional positron emission tomography (PET) studies into regions of interest (ROI) exhibiting similar temporal behavior is useful in diagnosis and evaluation of neurological images. Quantitative evaluation plays a crucial role in measuring the segmentation algorithm's performance. Due to the lack of "ground truth" available for evaluating segmentation of clinical images, automated segmentation results are usually compared with manual delineation of structures which is, however, subjective, and is difficult to perform. Alternatively, segmentation of co-registered anatomical images such as magnetic resonance imaging (MRI) can be used as the ground truth to the PET segmentation. However, this is limited to PET studies which have corresponding MRI. In this study, we introduce a framework for the objective and quantitative evaluation of functional PET study segmentation without the need for manual delineation or registration to anatomical images of the patient. The segmentation ...

  7. Gamma camera based Positron Emission Tomography: a study of the viability on quantification

    International Nuclear Information System (INIS)

    Positron Emission Tomography (PET) is a Nuclear Medicine imaging modality for diagnostic purposes. Pharmaceuticals labeled with positron emitters are used and images which represent the in vivo biochemical process within tissues can be obtained. The positron/electron annihilation photons are detected in coincidence and this information is used for object reconstruction. Presently, there are two types of systems available for this imaging modality: the dedicated systems and those based on gamma camera technology. In this work, we utilized PET/SPECT systems, which also allows for the traditional Nuclear Medicine studies based on single photon emitters. There are inherent difficulties which affect quantification of activity and other indices. They are related to the Poisson nature of radioactivity, to radiation interactions with patient body and detector, noise due to statistical nature of these interactions and to all the detection processes, as well as the patient acquisition protocols. Corrections are described in the literature and not all of them are implemented by the manufacturers: scatter, attenuation, random, decay, dead time, spatial resolution, and others related to the properties of each equipment. The goal of this work was to assess these methods adopted by two manufacturers, as well as the influence of some technical characteristics of PET/SPECT systems on the estimation of SUV. Data from a set of phantoms were collected in 3D mode by one camera and 2D, by the other. We concluded that quantification is viable in PET/SPECT systems, including the estimation of SUVs. This is only possible if, apart from the above mentioned corrections, the camera is well tuned and coefficients for sensitivity normalization and partial volume corrections are applied. We also verified that the shapes of the sources used for obtaining these factors play a role on the final results and should be delt with carefully in clinical quantification. Finally, the choice of the region

  8. Intrinsic spatial resolution limitations due to differences between positron emission position and annihilation detection localization; Limitacoes da resolucao espacial intrinseca devido as diferencas entre a posicao da emissao do positron e a deteccao da localizacao de aniquilacao

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Pedro; Malano, Francisco; Valente, Mauro, E-mail: valente@famaf.unc.edu.ar [Universidad Nacional de Cordoba, Cordoba (Argentina). Fac. de Matematica, Astronomia y Fisica (FaMAF)

    2012-07-01

    Since its successful implementation for clinical diagnostic, positron emission tomography (PET) represents the most promising medical imaging technique. The recent major growth of PET imaging is mainly due to its ability to trace the biologic pathways of different compounds in the patient's body, assuming the patient can be labeled with some PET isotope. Regardless of the type of isotope, the PET imaging method is based on the detection of two 511-keV gamma photons being emitted in opposite directions, with almost 180 deg between them, as a consequence of electron-positron annihilation. Therefore, this imaging method is intrinsically limited by random uncertainties in spatial resolutions, related with differences between the actual position of positron emission and the location of the detected annihilation. This study presents an approach with the Monte Carlo method to analyze the influence of this effect on different isotopes of potential implementation in PET. (author)

  9. Catecholaminergic neurotransmission in heart and brain, development of tracers for positron emission tomography

    OpenAIRE

    Langer, Claus Oliver

    2000-01-01

    The catecholamines norepinephrine and its biosynthetic precursor dopamine are two principal neurotransmitters in the human central nervous system (CNS). Moreover, norepinephrine is a major transmitter substance in the peripheral, autonomic nervous system. Positron emission tomography (PET) is a non-invasive imaging technique that uses positron-labeled molecules to image and measure the function of biological processes in vivo. Neuronal catecholaminergic pathways, both in CNS...

  10. In vivo monitoring of tissue function and metabolism using positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) relies on a combination of the use of positron-emitting radioactive tracers and computerized tomography to monitor certain physiological and functional characteristics in vivo and noninvasively. Its special and most powerful applications to date are in brain physiology and neurology. There are many potential research applications in farm animals, such as the mapping of neuro-humoral pathways, but cost and the need for special facilities are likely to be prohibitive

  11. Fabrication of polycrystalline scintillators for the positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Transparent ceramics are becoming more and more important for two new types of applications. On the one hand in cases where high mechanical and thermal demands in combination with optical properties are required, on the other hand where the optical properties of transparent materials like glass are not sufficient e.g. in positron-emission-tomography (PET) diagnostics. Most state of the art PET-scanners are using high-priced single crystals as scintillator material. The technological challenge is to replace single crystal by cost-efficient transparent ceramics. Producing transparent ceramics is ordered in synthesis of the powders and in manufacturing of these into transparent ceramics. The aim of this work was to synthesize single phase yttrium-alumina-and Luthetiumalumina-garnet (YAG, LuAG) powders partially doped with neodymium or praseodymium by four different synthesis routes (Pechini-synthesis, sol-gel-route, coprecipitation and solid state reactions). Additionally industrial LuAG and LuPO4 powders were characterized and manufactured. The powders were processed as submicron- and nanopowders. The compaction of nanopowder greenbodies sintered at high temperatures leads to a ''cross-over'' between both manufacturing route. Newly produced single-phase powders were homogenized with additions of sintering additives like tetraethyl orthosilicate (TEOS) and binders like polyvinyl alcohol (PVA). Moulding the powders were carried out by uniaxial pressing, cold isostatic pressing and in individual cases also by slip casting. The achieved green densities were in a range of 25-42 %. Examination of calcination behaviour leads to a calcination temperature of 1000 C with 2 hours dwell time in air atmosphere. Only solid state reactions resulted into transparent YAG, YAG:Pr, LuAG, LuAG:Pr ceramics. Solid state reactions of nanopowders resulted in heterogeneously transparent samples. Ceramics made by powders of other synthetic routes gave nontransparent ceramics due to porosity

  12. Vision 20/20: Positron emission tomography in radiation therapy planning, delivery, and monitoring.

    Science.gov (United States)

    Parodi, Katia

    2015-12-01

    Positron emission tomography (PET) is increasingly considered as an effective imaging method to support several stages of radiation therapy. The combined usage of functional and morphological imaging in state-of-the-art PET/CT scanners is rapidly emerging to support the treatment planning process in terms of improved tumor delineation, and to assess the tumor response in follow-up investigations after or even during the course of fractionated therapy. Moreover, active research is being pursued on new tracers capable of providing different insights into tumor function, in order to identify areas of the planning volume which may require additional dosage for improved probability of tumor control. In this respect, major progresses in the next years will likely concern the development and clinical investigation of novel tracers and image processing techniques for reliable thresholding and segmentation, of treatment planning and beam delivery approaches integrating the PET imaging information, as well as improved multimodal clinical instrumentation such as PET/MR. But especially in the rapidly emerging case of ion beam therapy, the usage of PET is not only limited to the imaging of external tracers injected to the patient. In fact, a minor amount of positron emitters is formed in nuclear fragmentation reactions between the impinging ions and the tissue, bearing useful information for confirmation of the delivered treatment during or after therapeutic irradiation. Different implementations of unconventional PET imaging for therapy monitoring are currently being investigated clinically, and major ongoing research aims at new dedicated detector technologies and at challenging applications such as real-time imaging and time-resolved in vivo verification of motion compensated beam delivery. This paper provides an overview of the different areas of application of PET in radiation oncology and discusses the most promising perspectives in the years to come for radiation therapy

  13. Vision 20/20: Positron emission tomography in radiation therapy planning, delivery, and monitoring

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is increasingly considered as an effective imaging method to support several stages of radiation therapy. The combined usage of functional and morphological imaging in state-of-the-art PET/CT scanners is rapidly emerging to support the treatment planning process in terms of improved tumor delineation, and to assess the tumor response in follow-up investigations after or even during the course of fractionated therapy. Moreover, active research is being pursued on new tracers capable of providing different insights into tumor function, in order to identify areas of the planning volume which may require additional dosage for improved probability of tumor control. In this respect, major progresses in the next years will likely concern the development and clinical investigation of novel tracers and image processing techniques for reliable thresholding and segmentation, of treatment planning and beam delivery approaches integrating the PET imaging information, as well as improved multimodal clinical instrumentation such as PET/MR. But especially in the rapidly emerging case of ion beam therapy, the usage of PET is not only limited to the imaging of external tracers injected to the patient. In fact, a minor amount of positron emitters is formed in nuclear fragmentation reactions between the impinging ions and the tissue, bearing useful information for confirmation of the delivered treatment during or after therapeutic irradiation. Different implementations of unconventional PET imaging for therapy monitoring are currently being investigated clinically, and major ongoing research aims at new dedicated detector technologies and at challenging applications such as real-time imaging and time-resolved in vivo verification of motion compensated beam delivery. This paper provides an overview of the different areas of application of PET in radiation oncology and discusses the most promising perspectives in the years to come for radiation therapy

  14. Vision 20/20: Positron emission tomography in radiation therapy planning, delivery, and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Parodi, Katia, E-mail: Katia.parodi@physik.uni-muenchen.de [Faculty of Physics, Department of Medical Physics, Ludwig Maximilians University Munich, Munich 85748 (Germany)

    2015-12-15

    Positron emission tomography (PET) is increasingly considered as an effective imaging method to support several stages of radiation therapy. The combined usage of functional and morphological imaging in state-of-the-art PET/CT scanners is rapidly emerging to support the treatment planning process in terms of improved tumor delineation, and to assess the tumor response in follow-up investigations after or even during the course of fractionated therapy. Moreover, active research is being pursued on new tracers capable of providing different insights into tumor function, in order to identify areas of the planning volume which may require additional dosage for improved probability of tumor control. In this respect, major progresses in the next years will likely concern the development and clinical investigation of novel tracers and image processing techniques for reliable thresholding and segmentation, of treatment planning and beam delivery approaches integrating the PET imaging information, as well as improved multimodal clinical instrumentation such as PET/MR. But especially in the rapidly emerging case of ion beam therapy, the usage of PET is not only limited to the imaging of external tracers injected to the patient. In fact, a minor amount of positron emitters is formed in nuclear fragmentation reactions between the impinging ions and the tissue, bearing useful information for confirmation of the delivered treatment during or after therapeutic irradiation. Different implementations of unconventional PET imaging for therapy monitoring are currently being investigated clinically, and major ongoing research aims at new dedicated detector technologies and at challenging applications such as real-time imaging and time-resolved in vivo verification of motion compensated beam delivery. This paper provides an overview of the different areas of application of PET in radiation oncology and discusses the most promising perspectives in the years to come for radiation therapy

  15. Decision logic for retreatment of asymptomatic lung cancer recurrence based on positron emission tomography findings

    International Nuclear Information System (INIS)

    Purpose: The purpose of the study was to determine if Positron emission tomography (PET) 2-[F-18] fluoro-2-deoxy-D-glucose (FDG) imaging could detect subclinical local lung cancer recurrence and whether retreatment of such recurrence was feasible and beneficial. Methods and Materials: Twenty patients with biopsy proven lung cancer were studied with Positron emission tomography for the purpose of detecting subclinical lung cancer recurrence over a period of 4.25 years. All patients were treated with external radiation as part or all of their therapy. Twenty patients had baseline PET and computed tomography (CT) studies for comparison with later studies. Surviving patients had a total of 40 sequential PET scans and 35 CT scans. The follow-up interval ranged from 5 to 40 months posttreatment. The differential uptake ratio (DUR) was determined for regions of interest of increased FDG uptake. Results: The median DUR value of the 20 baseline PET studies was 5.59. The DUR value of greater than 3 was empirically selected as being positive for tumor detection. On baseline studies, PET had a 100% correlation with the CT findings in regard to detection of the site of primary tumor involvement. Four of 20 patients showed areas of discordance in the mediastinal and hilar areas on initial PET and CT studies. Seven of 17 patients showed discordant posttreatment PET-CT findings. Two false positive PET studies were due to radiation pneumonitis and one to macrophage glycolysis in tumor necrosis. For detection of asymptomatic tumor recurrence, analysis of sequential PET and CT studies, biopsy results, and the patient's clinical course suggested that PET had a sensitivity of 100%, specificity of 89.3%, and accuracy of 92.5%. Computerized Tomography was found to have a sensitivity of 67%, specificity of 85%, and accuracy of 82% for detection of such early-stage recurrence. Five patients went on to have retreatment with external irradiation based upon the PET evidence. Four retreated

  16. Laparoscopic Scar: a mimicker of Sister Mary Joseph's nodule on positron emission tomography/CT

    International Nuclear Information System (INIS)

    Positron emission tomography/CT is an established imaging method in the diagnosis and staging of cancers. 18F-fluoro-2-deoxy-D-glucose (FDG) is the most commonly used radiotracer in positron emission tomography/CT. It is a tumour viability agent and usually its uptake within a lesion reflects the presence of a viable tumour tissue. However, false-positive FDG uptake is known to occur in benign processes of either inflammatory or infectious aetiology. We describe FDG uptake at the site of laparoscopic scar that mimicked Sister Mary Joseph's nodule in a patient with gastric adenocarcinoma. Here, the knowledge of the patient's history and subtle imaging findings helped in accurate staging of the patient. In this case report, we emphasize the value of the knowledge of the patient history and awareness of different pitfalls of FDG to achieve a correct diagnosis on positron emission tomography/CT

  17. Stages in the development of a dedicated positron emission tomography system for imaging small animals

    International Nuclear Information System (INIS)

    The stages in the development of a small diameter positron emission tomograph for the study of small animals are described. Initial experiments were performed with a pair of commercial, 4 mm multicrystal detectors at an inter-detector separation of 100 mm. The system's performance in this geometry was evaluated using physical and biological studies. These indicated the feasibility of using such detectors at this separation to delineate regional tracer kinetic information from small experimental animals. A small diameter, septa-less tomograph incorporating the detectors was simulated and biological data acquired which indicated the benefits of tomography compared with planar studies for imaging small animals. A tomograph incorporating 16 of the latest generation of block detector (3 mm crystals) in a ring diameter of 115 mm was constructed. The detectors were mounted on a 1 m2 vertical gantry and the system incorporated commercial hardware and software for data acquisition. The physical performance of the tomograph indicated that the spatial resolutions expected from the crystal size could be achieved at the centre of the field of view for all axes. However, the small diameter of the system resulted in larger degradation of the spatial resolution off-axis due to non-uniformity of detector sampling and photon penetration into neighbouring crystals. In spite of the physical problems posed by the small diameter of the system, useful in vivo studies on small animals are being routinely performed which assist in the development of novel radioligands and the interpretation of clinical positron emission tomography data and, in addition, provide a unique methodology to study the serial aspects of animal models of human disease. (author). 15 refs, 7 figs, 2 tabs

  18. The 511 keV emission from positron annihilation in the Galaxy

    Energy Technology Data Exchange (ETDEWEB)

    Prantzos, N.; Boehm, C.; Bykov, A. M.; Diehl, R.; Ferriere, K.; Guessoum, N.; Jean, P.; Knoedlseder, J.; Marcowith, A.; Moskalenko, I. V.; Strong, A.; Weidenspointner, G. [CNRS, UMR7095, UMPC and Institut d' Astrophysique de Paris, F-75014, Paris (France) and LAPP, 9 Chemin de Bellevue, BP 110 F-74941 Annecy-le-Vieux (France); A. F. Ioffe Institute of Physics and Technology, Russian Academy of Sciences, 194021, St. Petersburg (Russian Federation); Max Planck Institut fuer Extraterrestrische Physik, D-85741 Garching (Germany); Laboratoire d' Astrophysique de Toulouse-Tarbes, Universite de Toulouse, CNRS, 14 avenue Edouard Belin, F-31400 Toulouse (France); American University of Sharjah, College of Arts and Sciences/Physics Department, P.O. Box 26666, Sharjah (United Arab Emirates); CESR, Universite de Toulouse, CNRS, 9, Avenue du Colonel Roche, Boite Postal 4346, F-31028 Toulouse Cedex 4 (France); L.U.P.M., Universite Montpellier II, CNRS, Place Eugene Bataillon, F-34095 Montpellier (France); Hansen Experimental Physics Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, California 94305 (United States); Max Planck Institut fuer Extraterrestrische Physik, D-85741, Garching (Germany); Max Planck Institut fur Extraterrestrische Physik, Garching, D-85741 Germany, and MPI Halbleiterlabor, Otto-Hahn-Ring 6, D-81739 Muenchen (Germany)

    2011-07-01

    The first {gamma}-ray line originating from outside the Solar System that was ever detected is the 511 keV emission from positron annihilation in the Galaxy. Despite 30 years of intense theoretical and observational investigation, the main sources of positrons have not been identified up to now. Observations in the 1990s with OSSE/CGRO (Oriented Scintillation Spectrometer Experiment on GRO satellite/Compton Gamma Ray Observatory) showed that the emission is strongly concentrated toward the Galactic bulge. In the 2000s, the spectrometer SPI aboard the European Space Agency's (ESA) International Gamma Ray Astrophysics Laboratory (INTEGRAL) allowed scientists to measure that emission across the entire Galaxy, revealing that the bulge-to-disk luminosity ratio is larger than observed at any other wavelength. This mapping prompted a number of novel explanations, including rather ''exotic'' ones (e.g., dark matter annihilation). However, conventional astrophysical sources, such as type Ia supernovae, microquasars, or x-ray binaries, are still plausible candidates for a large fraction of the observed total 511 keV emission of the bulge. A closer study of the subject reveals new layers of complexity, since positrons may propagate far away from their production sites, making it difficult to infer the underlying source distribution from the observed map of 511 keV emission. However, in contrast to the rather well-understood propagation of high-energy (>GeV) particles of Galactic cosmic rays, understanding the propagation of low-energy ({approx}MeV) positrons in the turbulent, magnetized interstellar medium still remains a formidable challenge. The spectral and imaging properties of the observed 511 keV emission are reviewed and candidate positron sources and models of positron propagation in the Galaxy are critically discussed.

  19. A case of skeletal tuberculosis and psoas abscess: disease activity evaluated using 18 F-fluorodeoxyglucose positron emission tomography-computed tomography

    International Nuclear Information System (INIS)

    Psoas abscess complicating tuberculous spondylitis is a rare morbidity in extrapulmonary tuberculosis. There are no established guidelines for evaluating the clinical response of psoas abscess. Although several studies have shown that positron emission tomography-computed tomography with 18 F-fluorodeoxyglucose can play a potential role in diagnosing multifocal tuberculosis and monitoring the clinical response of pulmonary tuberculosis, to our knowledge, this is the first report demonstrating that positron emission tomography-computed tomography is useful for evaluating local inflammation and disease activity of a tuberculous psoas abscess. We report a case of multifocal bone and lymph node tuberculosis with concomitant lumbar psoas abscess in a 77-year-old man, along with a literature review. An initial positron emission tomography-computed tomography scan showed intense 18 F-fluorodeoxyglucose accumulation in the sternum, ribs, vertebrae, and lymph nodes. The patient was successfully treated with antitubercular agents and computed tomography-guided drainage therapy. A follow-up positron emission tomography-computed tomography after abscess drainage and 9 months of antitubercular drug treatment revealed that the majority of lesions improved; however, protracted inflammation surrounding the psoas abscess was still observed. These results indicate that disease activity of psoas abscess can remain, even after successful drainage and antitubercular medication regime of appropriate duration. We have successfully followed up the extent of skeletal tuberculosis complicated with psoas abscess by positron emission tomography-computed tomography. In this patient, positron emission tomography-computed tomography is useful for evaluating the disease activity of tuberculous psoas abscess and for assessing the appropriate duration of antitubercular drug therapy in psoas abscess

  20. Positron emission tomography alone, positron emission tomography-computed tomography and computed tomography in diagnosing recurrent cervical carcinoma: a systematic review and meta-analysis

    OpenAIRE

    Xiao, Yi; Wei, Jia; Zhang, Yicheng; Xiong, Weining

    2014-01-01

    Introduction The aim of the study was to assess systematically the accuracies of positron emission tomography (PET), PET/computed tomography (CT), and CT in diagnosing recurrent cervical cancer. Material and methods We searched for articles published from January 1980 to June 2013 using the following inclusion criteria: articles were reported in English; the use of PET, interpreted with or without the use of CT; use of CT to detect recurrent cervical cancer; and histopathologic analysis and/o...

  1. Positron emission tomography and migraine. Tomographie par emission de positons et migraine

    Energy Technology Data Exchange (ETDEWEB)

    Chabriat, H. (CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot)

    1992-04-01

    Positron emission tomography (PET) is a brain imaging technique that allows in vivo studies of numerous physiological parameters. There have been few PET studies in migraine patients. Cerebral blood flow changes with no variations in brain oxygen consumption have been reported in patients with prolonged neurologic manifestations during migraine attacks. Parenteral administration of reserpine during migraine headache has been followed by a fall in the overall cerebral uptake of glucose. The small sample sizes and a number of methodologic problems complicate the interpretation of these results. Recent technical advances and the development of new PET tracers can be expected to provide further insight into the pathophysiology of migraine. Today cerebral cortex 5 HT{sub 2} serotonin receptors can be studied in migraine patients with PET.

  2. Assessing tumor hypoxia by positron emission tomography with Cu-ATSM

    International Nuclear Information System (INIS)

    For the last several decades, hypoxia has been recognized to be one of the key factors in tumor aggression and an important impediment to local and distant control of malignant tumors. In addition, hypoxia is a major cause of failure of both radiation therapy and chemotherapy. It has been shown that hypoxia is an independent negative prognostic factor for patient outcome in various solid tumors. Clinical studies using polarographic oxygen electrodes, as a tool for measuring hypoxia, were the first to demonstrate the presence of hypoxia in human tumors and its association with poor prognosis. However, this method is invasive and has technical limitations that prevent its routine clinical use. Over the years, imaging as a noninvasive method has attracted a lot of attention and several radiotracers have been developed for noninvasive evaluation of hypoxia. One of the most promising radiotracers is the copper(2) complex of diacetyl-2,3-bis(N4-methyl-3-thiosemicarbazonato) ligand (Cu-ATSM) for imaging with positron emission tomography. In this review, the preclinical evaluation of Cu-ATSM as well as its clinical value in several solid tumors will be discussed.

  3. Cerebral metabolic data obtained by positron emission tomography in physiological aging. A review of the literature

    International Nuclear Information System (INIS)

    Following a summary of the general principles and limitations of metabolic measurements by positron emission tomography and of the different indices used to interpret the data, the authors review the results of published studies on physiological aging. Globally, with strict inclusion criteria absolute metabolic values at rest and under partial sensorial deprivation are little or not modified by age. In contrast, functional interactions between regions, as deduced from metabolic intercorrelations, are perhaps different in elderly people. In any case, positron emission tomography seems to discriminate between normal aging and different patterns of pathological aging. Technical improvements, more refined neuropsychological correlations and the use of dynamic activation paradigms will no doubt provide, in the future, a better definition of normal and pathological aging as positron tomography

  4. Cerebral metabolic data obtained by positron emission tomography in physiological aging. A review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Pellat, J.; Hommel, M.

    1987-06-18

    Following a summary of the general principles and limitations of metabolic measurements by positron emission tomography and of the different indices used to interpret the data, the authors review the results of published studies on physiological aging. Globally, with strict inclusion criteria absolute metabolic values at rest and under partial sensorial deprivation are little or not modified by age. In contrast, functional interactions between regions, as deduced from metabolic intercorrelations, are perhaps different in elderly people. In any case, positron emission tomography seems to discriminate between normal aging and different patterns of pathological aging. Technical improvements, more refined neuropsychological correlations and the use of dynamic activation paradigms will no doubt provide, in the future, a better definition of normal and pathological aging as positron tomography.

  5. Positron emission tomography in diagnosis and follow-up of treatment of head and neck tumours. Our initial experience

    International Nuclear Information System (INIS)

    Introduction: Positron emission tomography/ computed tomography (PET-CT) is one of the modalities that allow for imaging the metabolism of human cells. One of the indications for PET-CT is head and neck cancer staging and re staging. Aim of study: To test the diagnostic performance of PET-CT in a single centre study for head and neck cancer patients. Materials and methods: The study involved 60 patients with head and neck cancer diagnosed and treated in our department during 2008-2010. There were 71 PET-CT examinations (in 11 patients multiple studies were performed). In 40 patients PET-CT was performed for pre-operative staging, mainly to assess the presence of lymph node metastases. In 23 cases PET-CT was performed to confirm clinical suspicion of tumour recurrence. In 8 patients, the examination was performed to find the origin of the unknown primary cancer. Results: Positron emission tomography/ computed tomography results were compared with conventional imaging modalities and histopathology. In the surgical treatment group 4 false positive findings after histological examination were detected. PET-CT in 2 patients failed to show metastasis to the regional lymph nodes (false negative report). In patients with suspected recurrent tumour the diagnosis was confirmed in 14 cases. In all patients with metastases from an unknown primary origin, PET-CT was positive (4 cases were confirmed clinically). The results of PET-CT studies helped to change the method of treatment in 21 cases. Conclusion: Positron emission tomography/ computed tomography may be a valuable tool in detecting, staging and monitoring of selected patients with head and neck cancer, with a significant impact on clinical decision making. (authors)

  6. Use of transputers in a 3-D positron emission tomograph

    International Nuclear Information System (INIS)

    This paper discusses the use of a VME-based transputer system as a front-end parallel processing engine for Positron Volume Imaging. The authors model different topologies with different numbers of nodes, using the Master/Worker software paradigm called a Processor Farm, and determine optimum configuration parameters for different computation requirements. The versatility and scalability of transputers makes them very suitable for use in PVI tomographs in that the same transputers can be used for speeding up data acquisition, image reconstruction and display

  7. Graphics processing unit (GPU)-accelerated particle filter framework for positron emission tomography image reconstruction.

    Science.gov (United States)

    Yu, Fengchao; Liu, Huafeng; Hu, Zhenghui; Shi, Pengcheng

    2012-04-01

    As a consequence of the random nature of photon emissions and detections, the data collected by a positron emission tomography (PET) imaging system can be shown to be Poisson distributed. Meanwhile, there have been considerable efforts within the tracer kinetic modeling communities aimed at establishing the relationship between the PET data and physiological parameters that affect the uptake and metabolism of the tracer. Both statistical and physiological models are important to PET reconstruction. The majority of previous efforts are based on simplified, nonphysical mathematical expression, such as Poisson modeling of the measured data, which is, on the whole, completed without consideration of the underlying physiology. In this paper, we proposed a graphics processing unit (GPU)-accelerated reconstruction strategy that can take both statistical model and physiological model into consideration with the aid of state-space evolution equations. The proposed strategy formulates the organ activity distribution through tracer kinetics models and the photon-counting measurements through observation equations, thus making it possible to unify these two constraints into a general framework. In order to accelerate reconstruction, GPU-based parallel computing is introduced. Experiments of Zubal-thorax-phantom data, Monte Carlo simulated phantom data, and real phantom data show the power of the method. Furthermore, thanks to the computing power of the GPU, the reconstruction time is practical for clinical application. PMID:22472843

  8. Comparison of fluorine-18 and bromine-76 imaging in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, M.J.; Ferreira, N. [Service Hospitalier Frederic Joliot, CEA, Orsay (France)]|[Servico de Biofisica - IBILI - FMC, Coimbra (Portugal); Almeida, P.; Strul, D.; Loc`h, C.; Brulon, V.; Trebossen, R.; Maziere, B.; Bendriem, B. [Service Hospitalier Frederic Joliot, CEA, Orsay (France)

    1999-07-01

    State of the art positron emission tomography (PET) systems allow for scatter and attenuation correction. However, the size of the structure being studied and the region of interest (ROI) chosen also influence the accuracy of measurements of radioactive concentration. Furthermore, the limited spatial resolution of PET tomographs, which depends, among other factors, on the range of positrons in matter, can also contribute to a loss in quantitation accuracy. In this paper we address the influence of positron range, structure size and ROI size on the quantitation of radioactive concentration using PET. ECAT EXACT HR+ (HR+) and ECAT 953B/31 (ECAT 953B) PET systems were used in phantom acquisitions performed with two radioisotopes with different positron ranges. The 3D Hoffman phantom was scanned on both scanners with both radioisotopes, to visually analyse the image quality. A resolution phantom having six spheres of different diameters in a Plexiglas cylinder was used to calculate the values of the contrast recovery coefficient or hot spot recovery coefficient and of the spill-over or cold spot recovery coefficient under different imaging conditions used in clinical routine at our institution. Activity ratios were varied between 2 and 30 or between 0.4 and 200 by filling the spheres with fluorine-18 or bromine-76 respectively and the cylinder with {sup 11}C. Dynamic scans were performed on each scanner. Data were reconstructed using the same parameters as are used in clinical protocols. The variations in sphere and cylinder activities with time were fitted using the function M(t)=k{sub 1}.A(t)+k{sub 2}.B(t), where M(t) is the radioactivity concentration measured in an ROI placed on each sphere and A(t) and B(t) represent the true radioactivity concentrations present at time t in the spheres and in the cylinder respectively. k{sub 1} and k{sub 2} are factors representing the contrast recovery coefficient and the spill-over from surrounding activity on measurements

  9. Positron Emission Tomography and Optical Imaging of Tumor CD105 Expression with a Dual-Labeled Monoclonal Antibody

    OpenAIRE

    Zhang, Yin; Hong, Hao; Engle, Jonathan W.; Yang, Yunan; Theuer, Charles P.; Barnhart, Todd E.; Cai, Weibo

    2012-01-01

    CD105 (endoglin) is an independent prognostic marker for poor prognosis in > 10 solid tumor types, including breast cancer. The goal of this study was to develop a CD105-specific agent for both positron emission tomography (PET) and near-infrared fluorescence (NIRF) imaging, which can have potential clinical applications in diagnosis and imaged-guided surgery of breast cancer. TRC105, a chimeric anti-CD105 monoclonal antibody, was labeled with both a NIRF dye (i.e. 800CW) and 64Cu to yield 64...

  10. 99mTc bone scan and fluorodeoxyglucose positron emission tomography in evaluation of disseminated langerhans cell histiocytosis

    International Nuclear Information System (INIS)

    Langerhans cell histiocytosis (LCH) is a rare histiocytic disorder in which pathological langerhans cells accumulate in a variety of organs. Manifestations may include lung infiltrates, lymph node involvements, bone lesions, hepatic, hematopoietic and endocrine dysfunctions. In this case report we present fluorine-18 positron emission tomography (F-18 PET/CT) and bone scintigraphy findings of a 18-year-old male patient with disseminated LCH, mimicking multiple hypermetabolic metastatic lesions. Clinicians should be aware that LCH infiltrations can be seen as intense uptake and to differentiate infiltrations from other metastatic intense uptake with fluorodeoxyglucose PET/CT and bone scintigraphy, clinical and laboratory findings should be kept in mind. (author)

  11. Venous thrombosis of sarcoidosis as an unusual incidental finding on 18F-fluorodeoxyglucose positron emission tomography/computed tomography

    International Nuclear Information System (INIS)

    Sarcoidosis is defined as a multisystem granulomatous disorder of unknown cause. Venous thrombosis (VT) in the sarcoidosis is rare. The routine use of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has resulted in clinicians detecting many incidental findings, which have proven to be clinically significant such as thrombosis. Here, we present a case with VT of sarcoidosis in the inferior vena cava and portal vein as an unusual incidental finding on 18F-FDG PET/CT

  12. Time resolution in scintillator based detectors for positron emission tomography

    International Nuclear Information System (INIS)

    In the domain of medical photon detectors L(Y)SO scintillators are used for positron emission tomography (PET). The interest for time of flight (TOF) in PET is increasing since measurements have shown that new crystals like L(Y)SO coupled to state of the art photodetectors, e.g. silicon photomultipliers (SiPM), can reach coincidence time resolutions (CTRs) of far below 500ps FWHM. To achieve these goals it is important to study the processe in the whole detection chain, i.e. the high energy particle or gamma interaction in the crystal, the scintillation process itself, the light propagation in the crystal with the light transfer to the photodetector, and the electronic readout. In this thesis time resolution measurements for a PET like system are performed in a coincidence setup utilizing the ultra fast amplifier discriminator NINO. We found that the time-over-threshold energy information provided by NINO shows a degradation in energy resolution for higher SiPM bias voltages. This is a consequence of the increasing dark count rate (DCR) of the SiPM with higher bias voltages together with the exponential decay of the signal. To overcome this problem and to operate the SiPM at its optimum voltage in terms of timing we developed a new electronic board that employs NINO only as a low noise leading edge discriminator together with an analog amplifier which delivers the energy information. With this new electronic board we indeed improved the measured CTR by about 15%. To study the limits of time resolution in more depth we measured the CTR with 2x2x3mm3 LSO:Ce codoped 0.4%Ca crystals coupled to commercially available SiPMs (Hamamatsu S10931-50P MPPC) and achieved a CTR of 108±5ps FWHM at an energy of 511keV. We determined the influence of the data acquisition system and the electronics on the CTR to be 27±2ps FWHM and thus negligible. To quantitatively understand the measured values, we developed a Monte Carlo simulation tool in MATLAB that incorporates the timing

  13. Positron emission tomography/computerized tomography imaging of multiple focus of neurolymphomatosis

    International Nuclear Information System (INIS)

    Neurolymphomatosis is defined as infiltration of the peripheral nervous system by malignant lymphocytes in the presence of lymphoma. In this case, we described multiple neurol involvement and findings of 18F-fluorodeoxyglucose positron emission tomography/computerized tomography in a 35-year-old female diagnosed with B-cell lymphoma

  14. Recurrent ovarian endodermal sinus tumor: demonstration by computed tomography, magnetic resonance imaging, and positron emission tomography

    International Nuclear Information System (INIS)

    We report a case of recurrent endodermal sinus tumor of the ovary that was identified and/or clearly depicted by computed tomography, magnetic resonance imaging, and positron emission tomography. The potential roles of various imaging modalities in the detection of recurrent endodermal sinus tumor are discussed. (orig.)

  15. Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography in evaluation of residual intramuscular myxoma

    International Nuclear Information System (INIS)

    Intramuscular myxoma (IM) is a rare benign neoplasm. In a patient diagnosed with IM of left thigh, we report the utility of a postoperative fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography scan in assessing the efficacy of surgical excision

  16. Monitoring liver tumor therapy with [18F]FDG positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) with [18F]-2-flurodeoxy-glucose (FDG) can be utilized as a functional imaging modality for monitoring liver tumor therapy. We report three cases in which PET-FDG was more useful for this purpose than other imaging methods and tumor markers

  17. Tomography by positrons emission: integral unit to the service of Mexico

    International Nuclear Information System (INIS)

    The applications of the Positron emission tomography (PET) together with the one radiopharmaceutical 2 - [18 F]-fluoro-2-deoxy-D-glucose in the area of the medical imaging is expanding quickly and it possesses a bigger impact at the moment in favor of those patient to who suffers an oncological, cardiac or neurological illness in Mexico. (Author)

  18. On the possible mixing of the electron capture and the positron emission channels in nuclear decay

    OpenAIRE

    Isakov, V. I.

    2009-01-01

    On the basis of the idea of mixing (interaction) between the electron capture and the positron emission channels in the \\beta^+ decay in the cases when both channels are energetically allowed, we attempt to explain oscillations of the K-capture rates that were possibly seen in the recent experiment.

  19. Small animal positron emission tomography imaging and in vivo studies of atherosclerosis

    DEFF Research Database (Denmark)

    Hag, Anne Mette Fisker; Ripa, Rasmus Sejersten; Pedersen, Sune Folke;

    2013-01-01

    Atherosclerosis is a growing health challenge globally, and despite our knowledge of the disease has increased over the last couple of decades, many unanswered questions remain. As molecular imaging can be used to visualize, characterize and measure biological processes at the molecular and cellu...... knowledge obtained from in vivo positron emission tomography studies of atherosclerosis performed in small animals....

  20. Characterisation of beta(2)-adrenoceptors, using the agonist [C-11]formoterol and positron emission tomography

    NARCIS (Netherlands)

    Visser, T.J; van Waarde, Aaren; Doze, P; Elsinga, P.H; van der Mark, Thomas W.; Kraan, Jan; Ensing, Kees; Vaalburg, W.

    1998-01-01

    The agonist radioligand N-[2-hydroxy-5-[1-hydroxy-2-[[2-(4-[C-11]-methoxyphenyl)-1-methylethyl]amino]ethyl]phenyl]formamide ([C-11]formoterol) was synthesised in order to test its ability to visualise pulmonary beta(2)-adrenoceptors in vivo, with positron emission tomography (PET). Formoterol was la

  1. Capillaries within compartments: microvascular interpretation of dynamic positron emission tomography data

    DEFF Research Database (Denmark)

    Munk, O L; Keiding, S; Bass, L

    2003-01-01

    Measurement of exchange of substances between blood and tissue has been a long-lasting challenge to physiologists, and considerable theoretical and experimental accomplishments were achieved before the development of the positron emission tomography (PET). Today, when modeling data from modern PE...

  2. Diffuse nesidioblastosis diagnosed on a Ga-68 DOTATATE positron emission tomography/computerized tomography.

    Science.gov (United States)

    Arun, Sasikumar; Rai Mittal, Bhagwant; Shukla, Jaya; Bhattacharya, Anish; Kumar, Praveen

    2013-07-01

    The authors describe a 50 days old pre-term infant with persistent hyperinsulinemic hypoglycemia of infancy in whom Ga-68 DOTATATE positron emission tomography/computerized tomography scan showed diffusely increased tracer uptake in the entire pancreas with no abnormal tracer uptake anywhere else in the body, suggestive of a diffuse variant of nesidioblastosis. PMID:24250024

  3. Positron emission imaging device and method of using the same

    Science.gov (United States)

    Bingham, Philip R.; Mullens, James Allen

    2013-01-15

    An imaging system and method of imaging are disclosed. The imaging system can include an external radiation source producing pairs of substantially simultaneous radiation emissions of a picturization emission and a verification emissions at an emission angle. The imaging system can also include a plurality of picturization sensors and at least one verification sensor for detecting the picturization and verification emissions, respectively. The imaging system also includes an object stage is arranged such that a picturization emission can pass through an object supported on said object stage before being detected by one of said plurality of picturization sensors. A coincidence system and a reconstruction system can also be included. The coincidence can receive information from the picturization and verification sensors and determine whether a detected picturization emission is direct radiation or scattered radiation. The reconstruction system can produce a multi-dimensional representation of an object imaged with the imaging system.

  4. (18)F-Labeling of Arenes and Heteroarenes for Applications in Positron Emission Tomography.

    Science.gov (United States)

    Preshlock, Sean; Tredwell, Matthew; Gouverneur, Véronique

    2016-01-27

    Diverse radiochemistry is an essential component of nuclear medicine; this includes imaging techniques such as positron emission tomography (PET). As such, PET can track diseases at an early stage of development, help patient care planning through personalized medicine and support drug discovery programs. Fluorine-18 is the most frequently used radioisotope in PET radiopharmaceuticals for both clinical and preclinical research. Its physical and nuclear characteristics (97% β(+) decay, 109.8 min half-life, 635 keV positron energy) and high specific activity make it an attractive nuclide for labeling and molecular imaging. Arenes and heteroarenes are privileged candidates for (18)F-incorporation as they are metabolically robust and therefore widely used by medicinal chemists and radiochemists alike. For many years, the range of (hetero)arenes amenable to (18)F-fluorination was limited by the lack of chemically diverse precursors, and of radiochemical methods allowing (18)F-incorporation in high selectivity and efficiency (radiochemical yield and purity, specific activity, and radio-scalability). The appearance of late-stage fluorination reactions catalyzed by transition metal or small organic molecules (organocatalysis) has encouraged much research on the use of these activation manifolds for (18)F-fluorination. In this piece, we review all of the reactions known to date to install the (18)F substituent and other key (18)F-motifs (e.g., CF3, CHF2, OCF3, SCF3, OCHF2) of medicinal relevance onto (hetero)arenes. The field has changed significantly in the past five years, and the current trend suggests that the radiochemical space available for PET applications will expand rapidly in the near future. PMID:26751274

  5. The Positron Emission Tomography. A diagnostic technique; Con la PET diagnosi precoce della malattia

    Energy Technology Data Exchange (ETDEWEB)

    Salvadori, P. [Consiglio Nazionale delle Ricerche, Istituto di Fisiologia Clinica, Chimica e Radiofarmaceutica, Gruppo PET/Ciclotrone, Pisa (Italy)

    2001-07-01

    Positron Emission Tomography (PET) is a new imaging modality, which is able to assess non-invasively the biochemical mechanisms, underlying physiological and pathophysiological processes in vivo in humans. The technique relies on the administration of radioactive tracers labeled with short-lived positron emitters, which need to be produced on site via a particle accelerator (cyclotron). Radionuclides are produced upon request and formulated into biologically active organic molecules having precise pharmacokinetics and specificity. The radiotracer can be detected by the PET scanner and represented as tomographic sections (images of body sections) showing its regional distribution and concentration. This makes it possible to address clinical questions concerning occurrence and evolution of many diseases as well as their response to therapy. The ability to image (measure) biological processes and not only anatomy enables PET to explore diseases in the very early stage, including those diseases which are not related to modifications of organ structure (e.g. psychiatric diseases, metabolic disorders, biochemical disfunction). PET plays a major role, in conjunction with the other imaging modalities, to improve diagnosis capabilities and disease mechanism understanding. [Italian] La PET e' correntemente utilizzata come efficace strumento clinico, per l'elevata sensibilita' e specificita', nella valutazione dell'iter diagnostico di pazienti con sospetta cardiopatia ischemica e nel processo di decision making clinico di pazienti con disfunzione ventricolare sinistra e cardiopatia ischemica, in quanto metodica di riferimento per la diagnosi di vitalita' miocardica. In campo oncologico, viene impiegata l'ormai ben documentata capacita' del fluorodesossiglucosio (FDG), un tracciante contenente fluoro-18 ed in grado di permettere la misura del consumo cellulare di glucosio, nel porre in evidenza all'esame PET il tessuto neoplastico

  6. New techniques for positron emission tomography in the study of human neurological disorders

    International Nuclear Information System (INIS)

    This progress report represents a summary of our performance during the two year period following initial start-up of these research activities at Michigan. Productivity has been excellent; already over 47 papers and abstracts have been published or accepted for publication from this still young program. They represent significant contributions to extending the technology of positron emission tomography in the study of human neurological disorders. Our focus is to develop more cost effective and efficient means for producing new functionally specific tracers and simpler, less expensive, means for acquiring and interpreting quantitative data. These improved processes are required for the future growth of PET as a sophisticated research tool and for the transfer of this technology to clinical use. Our approach concentrates on two separate yet related areas, radiosynthesis and data analysis. In subproject 1, Drs. Jewett and Mulholland have introduced innovative methods for improving 11C and 18F synthetic processes. In Subproject 2, Dr. Hutchins has laid the foundations for an objective analysis of the limitations and opportunities for quantifying regional PET data. In Subproject 3, Dr. Koeppe has extended rapid techniques for parameter estimation in kinetic modeling of new ligands. Finally, in Subproject 4, Dr. Frey has applied kinetic analysis to ligand tracing of the cholinergic neurotransmitter system in animal and human brain. These DOE supported studies have direct impact on clinical research here and elsewhere which is expected to improve diagnosis and treatment of degenerative neurological diseases, mental illness and brain tumors. 47 refs., 7 figs., 4 tabs

  7. Positron Emission Tomography to Assess the Outcome of Intraportal Islet Transplantation.

    Science.gov (United States)

    Eriksson, Olof; Selvaraju, Ramkumar; Eich, Torsten; Willny, Mariam; Brismar, Torkel B; Carlbom, Lina; Ahlström, Håkan; Tufvesson, Gunnar; Lundgren, Torbjörn; Korsgren, Olle

    2016-09-01

    No imaging methodology currently exists to monitor viable islet mass after clinical intraportal islet transplantation. We investigated the potential of the endocrine positron emission tomography (PET) marker [(11)C]5-hydroxytryptophan ([(11)C]5-HTP) for this purpose. In a preclinical proof-of-concept study, the ex vivo and in vivo [(11)C]5-HTP signal was compared with the number of islets transplanted in rats. In a clinical study, human subjects with an intraportal islet graft (n = 8) underwent two [(11)C]5-HTP PET and MRI examinations 8 months apart. The tracer concentration in the liver as a whole, or in defined hotspots, was correlated to measurements of islet graft function. In rat, hepatic uptake of [(11)C]5-HTP correlated with the number of transplanted islets. In human subjects, uptake in hepatic hotspots showed a correlation with metabolic assessments of islet function. Change in hotspot standardized uptake value (SUV) predicted loss of graft function in one subject, whereas hotspot SUV was unchanged in subjects with stable graft function. The endocrine marker [(11)C]5-HTP thus shows a correlation between hepatic uptake and transplanted islet function and promise as a tool for noninvasive detection of viable islets. The evaluation procedure described can be used as a benchmark for novel agents targeting intraportally transplanted islets. PMID:27325286

  8. Diagnosis of tumor and inflammation in the chest by positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) utilizing =fluorine-18=-fluorodeoxyglucose (FDG) has been shown to be highly accurate in differentiating benign from malignant pulmonary tumors. Our hospital started the PET clinics very recently. The FDG-PET for lung tumor diagnosis has been included in the menu of services from the beginning of this clinics. Our objective in this paper is to determine how effectively the FDG-PET reveals the nature of the tumor in the chest in relation to CT, tansthoracic fine-needle biopsy, and thoracotomy. Sixteen patients with lung lesions who had undergone PET were selected retrospectively as eligible for pathological justification. All the 14 cases of lung cancer showed highly positive uptake of FDG relative to the normal lung tissue. One case of benign tumor, one case of scarred aterectasis showed negative uptake. One case of active form of tuberculosis showed high uptake. Five lymph node stations in 3 cases were revealed to be the metastasized lymph nodes pathologically. FDG-PET visualized all of them. Absence of lymph node metastasis was confirmed in 7 cases. FDG-PET gave them negative results. (author)

  9. Positron emission tomography imaging of tumor cell metabolism and application to therapy response monitoring

    Directory of Open Access Journals (Sweden)

    Amarnath eChallapalli

    2016-02-01

    Full Text Available Cancer cells do reprogramme their energy metabolism to enable several functions such as generation of biomass including membrane biosynthesis, and overcoming bioenergetic and redox stress. In this article we review both established and evolving radioprobes developed in association with positron emission tomography (PET to detect tumor cell metabolism and effect of treatment. Measurement of enhanced tumor cell glycolysis using 2-deoxy-2-[18F]-fluoro-D-glucose is well established in the clinic. Analogues of choline including [11C]-choline and various fluorinated derivatives are being tested in several cancer types clinically with PET. In addition to these, there is an evolving array of metabolic tracers for measuring intracellular transport of glutamine and other amino acids or for measuring glycogenesis, as well as probes used as surrogates for fatty acid synthesis or precursors for fatty acid oxidation. In addition to providing us with opportunities for examining the complex regulation of reprogrammed energy metabolism in living subjects, the PET methods open up opportunities for monitoring pharmacological activity of new therapies that directly or indirectly inhibit tumor cell metabolism.

  10. Basic principles of positron emission tomography in oncology: Quantitation and whole body techniques

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) of the brain and heart has made important contributions in clinical and research applications in the fields of neurology and cardiology. The more recent applications of PET in tumor imaging has marked oncology as the next frontier in PET; however, the dilemma of rising health care cost will challenge the application of new technologies. This challenge can be approached by innovative and appropriate use of sophisticated technology in both the research and clinical realms. The current developments of PET imaging technology to accurately stage the extent of tumor, as well as monitor the effectiveness or ineffectiveness of new or current therapies will be an extremely valuable tool in research and in the cost effective management of cancer patients. In the future, the oncologist may be able to adjust the chemotherapy to the tumor response based on PET imaging. In other situations, PET may be able to predict that no existing therapy will elicit a durable response, resolving the patients and families uncertainty of whether extreme therapeutic measures would have made a significant difference. This paper reviews some of the recent developments and areas of research in tumor PET imaging, and describes some of the practical and technical aspects involved with FDG tumor quantitation and whole body PET imaging. (authors)

  11. Segmental acquisition method for stationary objects in 18F-fluorodeoxyglucose positron emission tomography tests

    International Nuclear Information System (INIS)

    We investigated whether images of stationary objects obtained by segmental acquisition with positron emission tomography using 2-deoxy-2-[18F]-fluoro-D-glucose (FDG-PET) are of a quality equivalent to those obtained by conventional continuous acquisition. Phantoms filled with FDG and mid-abdominal regions of 18 patients who underwent FDG-PET tests were imaged by both continuous and segmental acquisition methods. The total acquisition time was set to 3 min; in the segmental acquisition mode, imaging for 15 s was repeated 12 times. Segmental images (SIs) obtained by superimposition of the reconstructed images were compared quantitatively and visually with continuous images (CIs). In all the phantom and clinical studies, SIs were never worse than CIs. The variances of the background counts of SIs were 9.8% and 13.0% less those of CIs in phantom and clinical studies, respectively. Visual assessments showed that SIs provided better detection of hot areas and superior image quality when compared to CIs. For stationary objects, the quality of images obtained by the segmental method is equivalent to that of images obtained conventionally by continuous acquisition. Moreover, under some conditions SIs provide better results than CIs. (author)

  12. A Delphi study to establish national cost-effectiveness research priorities for positron emission tomography

    International Nuclear Information System (INIS)

    Objective: This study aimed to determine the key cost-effectiveness research questions relating to positron emission tomography (PET) in the UK. Methods: A systematic literature review was conducted to establish the existing knowledge base relating to the cost-effectiveness of PET in the various conditions for which it has been proposed. A three-round postal Delphi study of relevant individuals was used to determine the key cost-effectiveness research questions relating to PET in the UK. The content and structure of the Delphi study was informed by the results of the literature review. Results: The most important cost-effectiveness research priorities for the National Health Service (NHS) relating to PET were in the clinical areas of lung cancer, breast cancer and the assessment of myocardial viability. Gamma camera PET using coincidence imaging was highlighted as a modality whose clinical role needed to be determined urgently. Conclusion: Underlying the cost-effectiveness research priorities which were established is the need for evidence that the use of the various PET modalities as a diagnostic technique will alter patient management as compared to existing diagnostic strategies. The findings of the project provide a contemporary overview of the potential role for PET in the NHS and will be relevant to other countries

  13. Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET)/MRI for Lung Cancer Staging.

    Science.gov (United States)

    Ohno, Yoshiharu; Koyama, Hisanobu; Lee, Ho Yun; Yoshikawa, Takeshi; Sugimura, Kazuro

    2016-07-01

    Tumor, lymph node, and metastasis (TNM) classification of lung cancer is typically performed with the TNM staging system, as recommended by the Union Internationale Contre le Cancer (UICC), the American Joint Committee on Cancer (AJCC), and the International Association for the Study of Lung Cancer (IASLC). Radiologic examinations for TNM staging of lung cancer patients include computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG-PET), and FDG-PET combined with CT (FDG-PET/CT) and are used for pretherapeutic assessments. Recent technical advances in MR systems, application of fast and parallel imaging and/or introduction of new MR techniques, and utilization of contrast media have markedly improved the diagnostic utility of MRI in this setting. In addition, FDG-PET can be combined or fused with MRI (PET/MRI) for clinical practice. This review article will focus on these recent advances in MRI as well as on PET/MRI for lung cancer staging, in addition to a discussion of their potential and limitations for routine clinical practice in comparison with other modalities such as CT, FDG-PET, and PET/CT. PMID:27075745

  14. Diagnosis of tumor and inflammation in the chest by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Toshihiko; Kosaka, Noboru; Kudo, Koichiro; Arai, Takashi; Fujii, Kyoichi; Kabe, Junzaburo [International Medical Center, Tokyo (Japan)

    1996-12-01

    Positron emission tomography (PET) utilizing =fluorine-18=-fluorodeoxyglucose (FDG) has been shown to be highly accurate in differentiating benign from malignant pulmonary tumors. Our hospital started the PET clinics very recently. The FDG-PET for lung tumor diagnosis has been included in the menu of services from the beginning of this clinics. Our objective in this paper is to determine how effectively the FDG-PET reveals the nature of the tumor in the chest in relation to CT, tansthoracic fine-needle biopsy, and thoracotomy. Sixteen patients with lung lesions who had undergone PET were selected retrospectively as eligible for pathological justification. All the 14 cases of lung cancer showed highly positive uptake of FDG relative to the normal lung tissue. One case of benign tumor, one case of scarred aterectasis showed negative uptake. One case of active form of tuberculosis showed high uptake. Five lymph node stations in 3 cases were revealed to be the metastasized lymph nodes pathologically. FDG-PET visualized all of them. Absence of lymph node metastasis was confirmed in 7 cases. FDG-PET gave them negative results. (author)

  15. Value of positron emission tomography and computer tomography (PET/CT) for urologic malignancies; Interet de la tomographie par emission de positons couplee a la scanographie (TEP/TDM) dans les cancers urologiques

    Energy Technology Data Exchange (ETDEWEB)

    Boujelbene, N.; Mirimanoff, R.O.; Ozsahin, M.; Zouhair, A. [Service de radio-oncologie, CHU Vaudois (CHUV), rue du Bugnon 46, CH-1011 Lausanne (Switzerland); Prior, J.O.; Boubaker, A. [Service de medecine nucleaire, CHU Vaudois (CHUV), rue du Bugnon 46, CH-1011 Lausanne (Switzerland); Azria, D. [Service de radio-oncologie, CRLC Val d' Aurelle-Paul-Lamarque, rue Croix-Verte, parc Euromedecine, 34298 Montpellier cedex 5 (France); Universite Montpellier I, 5, boulevard Henri-IV, CS 19044, 34967 Montpellier cedex (France); Schaffer, M. [Service de radio-oncologie, Ludwig-Maximilians-Universitaet Muenchen, Marchioninistr. 15, 81377 Munich (Germany); Gez, E. [Service de radio-oncologie, The Tel Aviv Sourasky Medical Center, 6 Weizmann Street, Tel Aviv 64239 (Israel); Jichlinski, P. [Service d' urologie, CHU Vaudois (CHUV), rue du Bugnon 46, CH-1011 Lausanne (Switzerland); Meuwly, J.Y. [Service de radiologie, CHU Vaudois (CHUV), rue du Bugnon 46, CH-1011 Lausanne (Switzerland)

    2011-07-15

    Positron emission tomography is a functional imaging technique that allows the detection of the regional metabolic rate, and is often coupled with other morphological imaging technique such as computed tomography. The rationale for its use is based on the clearly demonstrated fact that functional changes in tumor processes happen before morphological changes. Its introduction to the clinical practice added a new dimension in conventional imaging techniques. This review presents the current and proposed indications of the use of positron emission/computed tomography for prostate, bladder and testes, and the potential role of this exam in radiotherapy planning. (authors)

  16. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography

    Science.gov (United States)

    Christensen, A. N.; Rydhög, J. S.; Søndergaard, R. V.; Andresen, T. L.; Holm, S.; Munck Af Rosenschöld, P.; Conradsen, K.; Jølck, R. I.

    2016-05-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy (10- and 22 Gy) in a high-energy beam setting (18 MV). The developed silver-nanosensor provided high radiopacity on the planning CT-scans sufficient for patient positioning in image-guided radiotherapy and provided dosimetric information about the absorbed dose with a 10% and 8% standard deviation for the stereotactic regimens, 10 and 22 Gy, respectively.Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The

  17. Three-dimensional imaging of hidden objects using positron emission backscatter

    International Nuclear Information System (INIS)

    Positron emission backscatter imaging is a technique for interrogation and three-dimensional (3-D) reconstruction of hidden objects when we only have access to the objects from one side. Using time-of-flight differences in detected direct and backscattered positron-emitted photons, we construct 3-D images of target objects. Recently at Los Alamos National Laboratory, a fully three-dimensional imaging system has been built and the experimental results are discussed in this paper. Quantitative analysis of images reconstructed in both two- and three-dimensions are also presented.

  18. {sup 18}F-FDG positron emission tomography in the early diagnosis of enterocolitis: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Kresnik, E.; Gallowitsch, H.J.; Igerc, I.; Kumnig, G.; Gomez, I.; Lind, P. [Nuclear Medicine and Special Endocrinology, PET Centre, General Hospital, St. Veiterstrasse 47, 9020 Klagenfurt (Austria); Mikosch, P.; Alberer, D.; Hebenstreit, A. [Department of Internal Medicine and Gastroenterology, General Hospital, Klagenfurt (Austria); Wuertz, F. [Department of Pathology, General Hospital, Klagenfurt (Austria); Kogler, D.; Gasser, J. [Department of Radiology, General Hospital, Klagenfurt (Austria)

    2002-10-01

    Collagenous and eosinophilic colitis are rare diseases characterised by chronic watery diarrhoea. Radiographic evaluation of the gastrointestinal tract and colonoscopy are usually non-diagnostic since as many as one-third of patients will have minor abnormalities. To date a few investigators have reported increased fluorine-18 fluorodeoxyglucose ({sup 18}F-FDG) uptake on positron emission tomography (PET) in patients with acute enterocolitis, but there have been no reports on the use of {sup 18}F-FDG PET for the diagnosis of collagenous or eosinophilic colitis in an early clinical stage. The aim of this preliminary study was to evaluate the usefulness of {sup 18}F-FDG PET in the early diagnosis of patients with colitis. We investigated five women (mean age 61.2{+-}12.1 years) who had been diagnosed as having colitis in an early clinical stage. In all but one of the patients, the diagnosis of colitis was based on biopsy. Magnetic resonance colonography, ultrasonography and colonoscopy were performed in all but one of the patients. Two women were identified as having collagenous colitis in an early clinical stage. Another two patients had eosinophilic colitis. The morphological imaging methods, magnetic resonance colonography and ultrasonography, yielded no suspicious findings, and the results of colonoscopy similarly showed no abnormalities. One patient had colitis due to bacterial infection. In all patients {sup 18}F-FDG PET showed a pathological increase in tracer uptake in the large bowel, suggestive of colitis. In four of the five patients, colitis was confirmed by histology, and in one, by bacterial analysis. {sup 18}F-FDG PET was able to detect colitis in an early clinical stage, when morphological imaging methods and colonoscopy were non-diagnostic. The early performance of {sup 18}F-FDG PET imaging in patients with possible colitis is encouraging. (orig.)

  19. Positron emission tomography response criteria in solid tumours criteria for quantitative analysis of [18F]-fluorodeoxyglucose positron emission tomography with integrated computed tomography for treatment response assessment in metastasised solid tumours: All that glitters is not gold.

    Science.gov (United States)

    Willemsen, Annelieke E C A B; Vlenterie, Myrella; van Herpen, Carla M L; van Erp, Nielka P; van der Graaf, Winette T A; de Geus-Oei, Lioe-Fee; Oyen, Wim J G

    2016-03-01

    For solid tumours, quantitative analysis of [(18)F]-fluorodeoxyglucose positron emission tomography with integrated computed tomography potentially can have significant value in early response assessment and thereby discrimination between responders and non-responders at an early stage of treatment. Standardised strategies for this analysis have been proposed, and the positron emission tomography response criteria in solid tumours (PERCIST) criteria can be regarded as the current standard to perform quantitative analysis in a research setting, yet is not implemented in daily practice. However, several exceptions and limitations limit the feasibility of PERCIST criteria. In this article, we point out dilemmas that arise when applying proposed criteria like PERCIST on an expansive set of patients with metastasised solid tumours. Clinicians and scientists should be aware of these limitations to prevent that methodological issues impede successful introduction of research data into clinical practice. Therefore, to deliver on the high potential of quantitative imaging, consensus should be reached on a standardised, feasible and clinically useful analysis methodology. This methodology should be applicable in the majority of patients, tumour types and treatments. PMID:26808297

  20. Determination of the positron diffusion length in Kapton by analysing the positronium emission

    International Nuclear Information System (INIS)

    Doppler profile spectroscopy and Compton-to-peak ratio analysis have been used to study the positronium (Ps) emission from the Kapton surface as a function of the positron implantation energy E. Two different positions for the sample have been performed in the experiment. In the first case the sample and the Ge-detector are perpendicular to the positron beam. With this geometry the emission of para-positronium (p-Ps) is detected as a narrow central peak. In the second case, by rotating the sample 45 deg. with respect to the beam axis, the emission of p-Ps is detected as a blue-shifted fly away peak. The implantation of the positrons is described by the Makhov profile, where we used the modified median implantation for polymers as given by Algers et al. [J. Algers, P. Sperr, W. Egger, G. Koegel, F.H.J. Maurer, Phys. Rev. B 67 (2003) 125404]. Thermalised positrons can diffuse to the surface and may pick up an electron to be emitted as Ps. We found a thermal and or epithermal positron diffusion length L+ = 5.43 ± 0.71 nm and L+ = 5.51 ± 0.28 nm correspondingly for both cases, which is much more than the one found by Brusa et al. [R.S. Brusa, A. Dupasquier, E. Galvanetto, A. Zecca, Appl. Phys. A 54 (1992) 233]. The respective efficiency for the emission of Ps by picking up an electron from the surface is found to be fpu = 0.247 ± 0.012 and fpu = 0.156 ± 0.003

  1. A new method of detection for a positron emission tomograph using a time of flight method

    International Nuclear Information System (INIS)

    In the first chapter, it is shown the advantages of positron radioemitters (β+) of low period, and the essential characteristics of positron tomographs realized at the present time. The second chapter presents the interest of an original technique of image reconstruction: the time of flight technique. The third chapter describes the characterization methods which were set for verifying the feasibility of cesium fluoride in tomography. Chapter four presents the results obtained by these methods. It appears that the cesium fluoride constitute presently the best positron emission associated to time of flight technique. The hypotheses made on eventual performances of such machines are validated by experiments with phantom. The results obtained with a detector (bismuth germanate) conserves all its interest in skull tomography

  2. A new positron emission particle tracking facility at iThemba LABS

    International Nuclear Information System (INIS)

    Positron emission particle tracking (PEPT) has become a powerful tool for in-situ characterisation and visualization of particulate flow within aggressive industrial environments, such as tumbling mills and powder mixers. PEPT is based on the tracking of a single tracer particle which has been labelled with a radionuclide that decays via beta-plus decay. The location of the particle is obtained by the triangulation of events associated with the detection of pairs of annihilation gamma rays in a modified 'positron camera.' One of the challenges facing PEPT is associated with labelling particles smaller than 100 μm which would allow studies in systems of finer particulate flow, such as flotation cells. The Positron Imaging Centre at the University of Birmingham is currently the only operational PEPT facility in the world. PEPT Cape Town will shortly become operational at iThemba LABS, South Africa. (author)

  3. Contribution of 18F-fluorodeoxyglucose positron emission tomography in the detection and evaluation of peritoneal metastasis in colorectal cancer

    International Nuclear Information System (INIS)

    Accurate detection of peritoneal metastasis in colorectal cancer remains a diagnostic challenge. The accuracy of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the diagnosis of peritoneal recurrence was evaluated, FDG-PET was conducted in 18 patients previously treated for colorectal cancer and suspected recurrence with clinical symptoms, computed tomography (CT), and tumor markers. Final Diagnosis was obtained by histological evaluation (n=14) or clinical follow-up (n=4). FDG-PET sensitivity was 88%, and accuracy in detecting peritoneal recurrence was 78%. For CT scans, sensitivity was 38% and accuracy 44% Six patients were suspected to have peritoneal recurrence based on FDG-PET and 5 were identified pathologically with peritoneal metastasis. Lesions smaller than 30 mm were not detected by CT. FDG-PET detected 15 mm lesions. In conclusion, FDG-PET is an accurate, noninvasive way to detect peritoneal recurrence in colorectal cancer and would play an important role in clinical management. (author)

  4. Positron emission tomography studies of central receptors in humans

    International Nuclear Information System (INIS)

    Central neurotransmitter systems and receptors are intimately involved in the mechanism of several neurologic and psychiatric disorders. One well-known example is the nigro-striatal dopaminergic system in akinesia of Parkinson's disease. Although neurotransmitter concentration and receptor function can be measured regionally post-mortem, positron tomography (PET) studies can be performed during life and therefore may provide insight into changes at early stages of the disease as well as follow-up data on, and pharmacological modification of, such changes. PET allows to monitor non-invasively the time-course of regional tissue tracer concentration following administration of a radioactive drug. If the latter is known to interact selectively with specific binding sites, it can be used to probe in vivo the regional distribution and affinity of the receptors involved. This principle was first pioneered using 3H or 14C-labeled ligands injected intravenously to laboratory animal, but necessitated brain tissue sampling for determination of regional radioactive concentration. The feasibility of the PET paradigm to characterize specific binding in vivo showed that trace amounts of 11C-labeled flunitrazepam could be displaced specifically from the baboon's brain by a therapeutic load of the unlabeled competitor Lorazepam, indicating that specific in vivo binding of the radioligand to the benzodiazepine (BZD) receptors has taken place

  5. Diagnostic role of fluorine-18 (18F fluorodeoxyglucose positron emission tomography computed tomography in detecting recurrent disease in patients with colorectal cancer and elevated carcinoembryonic antigen

    Directory of Open Access Journals (Sweden)

    Matovina Emil

    2015-01-01

    Full Text Available Introduction. Early detection of recurrence is an important factor for long term survival of patients with colorectal cancer. Measurement of serum levels of carcinoembryonic antigen has been commonly used in the postoperative surveillance of colorectal cancer. The purpose of this study was to evaluate the ability of positron emission tomography-computed tomography to detect pathological substrate of elevated serum carcinoembryonic antigen in patients with colorectal cancer. Material and Methods. The patients with colorectal cancer who underwent curative surgical resection and/ or chemotherapy, who were found in our database, were analyzed retrospectively. Forty-eight 18F- fluorodeoxyglucose positron emission tomography-computed tomography studies including 45 patients (14 women, 31 men; mean age: 62.93 years with elevated serum, carcinoembryonic antigen levels, which had been performed between January 2011 and January 2014, were evaluated. Serum levels of carcinoembryonic antigen were measured within 3 months after positron emission tomography-computed tomography examination. Final diagnosis of recurrence was made by histopathological findings, radiology studies or clinical follow-up. Results. Recurrences were diagnosed in 37 patients, the prevalence being 77.1%. Liver metastases were found in 18 patients, abdominal, pelvic and/or mediastinal lymph nodes were positive in 19 patients, 11 patients had loco regional recurrences and 4 patients had pulmonary metastasis, and bone metastases were found in one patient. One patient was diagnosed with metastasis in scar tissue. The overall sensitivity and specificity of positron emission tomography-computed tomography was 90.24% and 71.42%, respectively. The positive and negative predictive values were 94.87% and 55.56%, respectively. Conclusion. 18F- fluorodeoxyglucose positron emission tomography-computed tomography is a powerful tool that could be used in determining colorectal cancer recurrence in

  6. Lymph node metastasis of squamous cell carcinoma from an unknown primary: impact of positron emission tomography

    International Nuclear Information System (INIS)

    This study was performed to assess the potential benefit of positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) in patients with cervical metastasis of squamous cell carcinoma from an unknown primary tumour. Eighteen patients with cervical metastasis of squamous cell carcinoma from an unknown primary who were assessed by physical examination including transnasal fibre-endoscopy and radiological work-up with computed tomography were included in this prospective tertiary referral centre cohort study. The results of the search for the primary with rigid panendoscopy of the upper aerodigestive tract were compared to the evaluation with FDG PET. Panendoscopy revealed a primary tumour in 8/18 (44%) patients. PET accurately diagnosed five of these eight primary tumours, and gave one false positive and three false negative scans, resulting in a sensitivity of 63%, a specificity of 90%, an accuracy of 78%, a positive predictive value of 83% and a negative predictive value of 75%. Small primaries or primaries in areas with physiologically increased FDG uptake can be missed with PET owing to the limited resolution of the camera (approximately 5 mm). Our study in a small number of patients suggests that PET does not provide benefit in terms of detecting additional primary tumours if applied in addition to extensive clinical work-up. Considering its high specificity, PET could be of value as an initial evaluation instrument, reserving the need for extensive work-up to patients with negative scans. (orig.)

  7. The Use of Positron Emission Tomography in Soft Tissue Sarcoma Patients under Therapy with Trabectedin

    Directory of Open Access Journals (Sweden)

    Gerlinde Egerer

    2009-07-01

    Full Text Available Background: We used 2-deoxy-2-[18F] fluoro-D-glucose (FDG positron emission tomography (PET to evaluate the FDG uptake in patients with advanced and/or metastatic soft tissue sarcoma (STS undergoing therapy with Ecteinascidin-743 (ET-743, Trabectedin, YondelisTM. Patients and Methods: The pilot study included nine patients with metastatic STS receiving a minimum of one cycle of treatment with trabectedin. Patients were examined using PET prior to onset of therapy and after completion of one or three cycles of trabectedin. Restaging according to Response Evaluation Criteria in Solid Tumours (RECIST was performed in parallel using computed tomography (CT and/or magnetic resonance imaging (MRI and served for reference. Results: Clinical outcome of nine evaluable patients was as follows: one patient with partial remission (PR, three patients with stable disease (SD, and five patients with progressive disease (PD. A more than 40% decrease of the standardized uptake value (SUV of sequential PET examination could be demonstrated for the responding patient (PR, whereas patients with SD or PD showed a stable SUV, but no increase in SUV. Conclusion: To our knowledge, this is the first small series of patients being treated with trabectedin and monitored using sequential PET imaging demonstrating SUV stabilization in nearly all monitored patients.

  8. Attenuation correction with region growing method used in the positron emission mammography imaging system

    Science.gov (United States)

    Gu, Xiao-Yue; Li, Lin; Yin, Peng-Fei; Yun, Ming-Kai; Chai, Pei; Huang, Xian-Chao; Sun, Xiao-Li; Wei, Long

    2015-10-01

    The Positron Emission Mammography imaging system (PEMi) provides a novel nuclear diagnosis method dedicated for breast imaging. With a better resolution than whole body PET, PEMi can detect millimeter-sized breast tumors. To address the requirement of semi-quantitative analysis with a radiotracer concentration map of the breast, a new attenuation correction method based on a three-dimensional seeded region growing image segmentation (3DSRG-AC) method has been developed. The method gives a 3D connected region as the segmentation result instead of image slices. The continuity property of the segmentation result makes this new method free of activity variation of breast tissues. The threshold value chosen is the key process for the segmentation method. The first valley in the grey level histogram of the reconstruction image is set as the lower threshold, which works well in clinical application. Results show that attenuation correction for PEMi improves the image quality and the quantitative accuracy of radioactivity distribution determination. Attenuation correction also improves the probability of detecting small and early breast tumors. Supported by Knowledge Innovation Project of The Chinese Academy of Sciences (KJCX2-EW-N06)

  9. [(18F]Fluoroethyltyrosine- positron emission tomography-guided radiotherapy for high-grade glioma

    Directory of Open Access Journals (Sweden)

    Ratib Osman

    2008-12-01

    Full Text Available Abstract Background To compare morphological gross tumor volumes (GTVs, defined as pre- and postoperative gadolinium enhancement on T1-weighted magnetic resonance imaging to biological tumor volumes (BTVs, defined by the uptake of 18F fluoroethyltyrosine (FET for the radiotherapy planning of high-grade glioma, using a dedicated positron emission tomography (PET-CT scanner equipped with three triangulation lasers for patient positioning. Methods Nineteen patients with malignant glioma were included into a prospective protocol using FET PET-CT for radiotherapy planning. To be eligible, patients had to present with residual disease after surgery. Planning was performed using the clinical target volume (CTV = GTV ∪ BTV and planning target volume (PTV = CTV + 20 mm. First, the interrater reliability for BTV delineation was assessed among three observers. Second, the BTV and GTV were quantified and compared. Finally, the geometrical relationships between GTV and BTV were assessed. Results Interrater agreement for BTV delineation was excellent (intraclass correlation coefficient 0.9. Although, BTVs and GTVs were not significantly different (p = 0.9, CTVs (mean 57.8 ± 30.4 cm3 were significantly larger than BTVs (mean 42.1 ± 24.4 cm3; p 3; p Conclusion Using FET, the interrater reliability had excellent agreement for BTV delineation. With FET PET-CT planning, the size and geometrical location of GTVs and BTVs differed in a majority of patients.

  10. Detection of amyloid in Alzheimer's disease with positron emission tomography using [11C]AZD2184

    International Nuclear Information System (INIS)

    Current positron emission tomography (PET) radioligands for detection of Aβ amyloid in Alzheimer's disease (AD) are not ideal for quantification. To improve the signal to noise ratio we have developed the radioligand [11C]AZD2184 and report here the first clinical evaluation. Eight AD patients and four younger control subjects underwent 93-min PET measurements with [11C]AZD2184. A ratio approach using the cerebellum as reference region was applied to determine binding parameters. Brain uptake of [11C]AZD2184 peaked within 1 min at 3-4% of injected radioactivity. AD patients had high radioactivity in cortical regions while controls had uniformly low radioactivity uptake. Specific binding peaked within 30 min at which time standardized uptake value ratios (SUVR) ranged between 1.19 and 2.57. [11C]AZD2184 is a promising radioligand for detailed mapping of Aβ amyloid depositions in Alzheimer's disease, due to low non-specific binding, high signal to background ratio and reversible binding as evident from early peak equilibrium. (orig.)

  11. Positron emission tomography-computed tomography in the management of lung cancer: An update

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    Punit Sharma

    2013-01-01

    Full Text Available This communication presents an update on the current role of positron emission tomography-computed tomography (PET-CT in the various clinical decision-making steps in lung carcinoma. The modality has been reported to be useful in characterizing solitary pulmonary nodules, improving lung cancer staging, especially for the detection of nodal and metastatic site involvement, guiding therapy, monitoring treatment response, and predicting outcome in non-small cell lung carcinoma (NSCLC. Its role has been more extensively evaluated in NSCLC than small cell lung carcinoma (SCLC. Limitations in FDG PET-CT are encountered in cases of tumor histotypes characterized by low glucose uptake (mucinous forms, bronchioalveolar carcinoma, neuroendocrine tumors, in the assessment of brain metastases (high physiologic 18F-FDG uptake in the brain and in cases presenting with associated inflammation. The future potentials of newer PET tracers beyond FDG are enumerated. An evolving area is PET-guided assessment of targeted therapy (e.g., EGFR and EGFR tyrosine kinase overexpression in tumors which have significant potential for drug development.

  12. Preliminary assessment of fluorine-18 fluorodeoxyglucose positron emission tomography in patients with bladder cancer

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the feasibility of imaging of bladder cancer with fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scanning. We studied 12 patients with histologically proven bladder cancer who had undergone surgical procedures and/or radiotherapy. Retrograde irrigation of the urinary bladder with 1000-3710 ml saline was performed during nine of the studies. Dynamic and static PET images were obtained, and standardized uptake value images were reconstructed. FDG-PET scanning was true-positive in eight patients (66.7%), but false-negative in four (33.3%). Of 20 organs with tumor mass lesions confirmed pathologically or clinically, 16 (80%) were detected by FDG-PET scanning. FDG-PET scanning detected all of 17 distant metastatic lesions and two of three proven regional lymph node metastases. FDG-PET was also capable of differentiating viable recurrent bladder cancer from radiation-induced alterations in two patients. In conclusion, these preliminary data indicate the feasibility of FDG-PET imaging in patients with bladder cancer, although a major remaining pitfall is intense FDG accumulation in the urine. (orig.). With 3 figs., 1 tab

  13. 18F-fluorodeoxyglucose positron emission tomography might be useful for diagnosis of hepatic amyloidosis

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    Tawada A

    2014-06-01

    Full Text Available Akinobu Tawada,1 Tatsuo Kanda,1 Takashi Oide,2 Toshio Tsuyuguchi,1 Fumio Imazeki,1,3 Yukio Nakatani,2 Osamu Yokosuka11Department of Gastroenterology, 2Department of Diagnostic Pathology, Chiba University Hospital, Chuo-ku, Chiba, Japan; 3Safety and Health Organization, Chiba University, Inage-ku, Chiba, JapanAbstract: We report on a woman with hepatic involvement of primary systemic (immunoglobulin light chain, AL amyloidosis. Her diagnosis was confirmed by liver biopsy. Clinical symptoms of hepatic amyloidosis are generally mild at its first stage, with most frequent findings being hepatomegaly and alkaline phosphatase elevation. Recent advances in the understanding of the pathophysiology of systemic amyloidosis have made several treatments available. However, its prognosis is occasionally poor. Because liver biopsy is not always safe, other modalities for the diagnosis are needed. Of interest was that fluorodeoxyglucose (FDG uptake into the liver was observed, compared with that into the spleen, in this patient, indicating that FDG positron emission tomography and computed tomography might be useful for the diagnosis of hepatic amyloidosis with mild liver dysfunction.Keywords: amyloidosis, diagnosis, hepatic involvement, FDG PET

  14. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography.

    Science.gov (United States)

    Christensen, A N; Rydhög, J S; Søndergaard, R V; Andresen, T L; Holm, S; Munck Af Rosenschöld, P; Conradsen, K; Jølck, R I

    2016-06-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive (106)Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy (10- and 22 Gy) in a high-energy beam setting (18 MV). The developed silver-nanosensor provided high radiopacity on the planning CT-scans sufficient for patient positioning in image-guided radiotherapy and provided dosimetric information about the absorbed dose with a 10% and 8% standard deviation for the stereotactic regimens, 10 and 22 Gy, respectively. PMID:27174233

  15. Hemodynamic evaluation by positron-emission CT after surgical treatment for children with moyamoya disease

    International Nuclear Information System (INIS)

    Cerebral circulation was measured in 3 children with moyamoya disease by means of positron-emission CT (PET) using the C15O2 continuous-inhalation method. The sequential change in the rCBF pattern was monitored before and after surgery. The initial symptoms of the three children were TIA, ICH, and complete stroke. A preoperative PET study revealed hypoperfusion areas in the frontal, temporal, and parietal cortexes and hyperperfusion areas in the basal ganglia and occipital cortex in each case. All cases were treated by combined EMS and EDAS or by EMS alone. The postoperative clinical course was good in the TIA- and ICH-onset cases, but left hemiparesis remained in the stroke-onset case. PET scans were repeated from 46 days to 126 days after the operation. An increase in the CBF in the parietal cortex was seen in the TIA- and ICH-onset cases, but no change was seen in the stroke-onset case. Our experience indicates that surgical treatment can be an effective procedure for preventing cerebral ischemic attack and reducing the hyperperfusional state at the basal ganglia in children with moyamoya disease, but no such effects can be expected in cases with permanent neurological deficits. (author)

  16. Positron emission tomography: Which indications, which benefits?; Tomographie par emission de positons (TEP): quelles indications, quels benefices?

    Energy Technology Data Exchange (ETDEWEB)

    Chassoux, F. [Ctr Hosp St Anne, Serv Neurochirurg, F-75014 Paris (France); Chassoux, F.; Chiron, C. [CEA, I2BM, Serv Hosp Frederic Joliot, F-91 Orsay (France); Chiron, C. [Hop Necker Enfants Malad, INSERM, U663, F-75015 Paris (France); Chassoux, F.; Chiron, C. [Univ Paris 06, F-75005 Paris (France)

    2008-07-01

    Positron emission tomography (PET) is currently used in the pre-surgical workup for drug-resistant partial epilepsies in addition to MRI. Inter-ictal metabolism is studied in clinical practice using {sup 18}fluoro-desoxy-glucose ({sup 18}FDG). In medial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis, hypo-metabolism ipsilateral to the epileptogenic focus is found in 70-90% of cases. However, hypo-metabolism is larger than the structural lesion observed on MRI and includes the epileptogenic zone and ictal discharge spread areas. Hypo-metabolism is related to surgical outcome and cognitive disturbances in MTLE. Although the usefulness of PET appears less well-established in extra-temporal lobe epilepsy and in children, its sensitivity may be improved by co-registration and superimposition of PET on MRI at any age. Focal hypo-metabolism can be easily detected by visual analysis, allowing detection of minor gyral abnormalities that may correspond to focal cortical dysplasias. Moreover, in cases of negative MRI, focal hypo-metabolism findings may help invasive monitoring planning and deep electrode placement for SEEG, and finally improve surgical outcome. (authors)

  17. Pioneering and fundamental achievements on the development of positron emission tomography (PET) in oncology

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG), a glucose analog, is widely used throughout the world as an indispensable imaging modality for the management of cancer treatment. This article reviews the pioneering achievements of PET in oncology with a focus on the development of PET that occurred from 1980 through the early-1990s. 18F-FDG was first applied for imaging of animal tumors in 1980 and for brain tumor imaging clinically in 1982. 18F-FDG enabled to visualize liver metastasis as clear positive image that could not be obtained by conventional nuclear imaging. Subsequently, 18F-FDG was used for imaging various cancers, such as lung, pancreas, colorectal and hepatoma. 11C-L-methionine (11C-MET) that reflects amino acid transport of cancers has an advantage that its uptake is lower in the brain and inflammatory tissue compared to 18F-FDG, and was first applied for imaging lung cancer and brain tumor. 18F-FDG and 11C-MET were proved to be sensitive tracers that can be used to objectively evaluate the effectiveness of cancer treatment. The diagnostic accuracy of PET, which is critical in clinical practice, was evaluated for the differential diagnosis of malignant and benign lung nodules using 18F-FDG or 11C-MET. In addition to 18F-FDG and 11C-MET, many radiopharmaceuticals were developed, such as 18F-labled thymidine analogs for evaluating proliferative activity, 18F-fluoromisonidazole for imaging of hypoxia, and 18F-fluorodeoxygalactose for evaluating liver-specific galactose metabolism and for imaging of hepatoma that retains galactose metabolic activity. These early efforts and achievements have greatly contributed to the development and clinical application of 18F-FDG PET in oncology. (author) 113 refs.

  18. Importance of defect detectability in Positron Emission Tomography imaging of abdominal lesions

    Directory of Open Access Journals (Sweden)

    Shozo Yamashita

    2015-07-01

    Full Text Available Objective(s: This study was designed to assess defect detectability in positron emission tomography (PET imaging of abdominal lesions. Methods: A National Electrical Manufactures Association International Electrotechnical Commission phantom was used. The simulated abdominal lesion was scanned for 10 min using dynamic list-mode acquisition method. Images, acquired with scan duration of 1-10 min, were reconstructed using VUE point HD and a 4.7 mm full-width at half-maximum (FWHM Gaussian filter. Iteration-subset combinations of 2-16 and 2-32 were used. Visual and physical analyses were performed using the acquired images. To sequentially evaluate defect detectability in clinical settings, we examined two middle-aged male subjects. One had a liver cyst (approximately 10 mm in diameter and the other suffered from pancreatic cancer with an inner defect region (approximately 9 mm in diameter. Results: In the phantom study, at least 6 and 3 min acquisition durations were required to visualize 10 and 13 mm defect spheres, respectively. On the other hand, spheres with diameters ≥17 mm could be detected even if the acquisition duration was only 1 min. The visual scores were significantly correlated with background (BG variability. In clinical settings, the liver cyst could be slightly visualized with an acquisition duration of 6 min, although image quality was suboptimal. For pancreatic cancer, the acquisition duration of 3 min was insufficient to clearly describe the defect region. Conclusion: The improvement of BG variability is the most important factor for enhancing lesion detection. Our clinical scan duration (3 min/bed may not be suitable for the detection of small lesions or accurate tumor delineation since an acquisition duration of at least 6 min is required to visualize 10 mm lesions, regardless of reconstruction parameters. Improvements in defect detectability are important for radiation treatment planning and accurate PET-based diagnosis.

  19. When to perform positron emission tomography/computed tomography or radionuclide bone scan in patients with recently diagnosed prostate cancer

    Directory of Open Access Journals (Sweden)

    Caldarella C

    2013-06-01

    Full Text Available Carmelo Caldarella,1 Giorgio Treglia,2 Alessandro Giordano,1 Luca Giovanella2 1Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Rome, Italy; 2Department of Nuclear Medicine and PET/CT Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland Abstract: Skeletal metastases are very common in prostate cancer and represent the main metastatic site in about 80% of prostate cancer patients, with a significant impact in patients' prognosis. Early detection of bone metastases is critical in the management of patients with recently diagnosed high-risk prostate cancer: radical treatment is recommended in case of localized disease; systemic therapy should be preferred in patients with distant secondary disease. Bone scintigraphy using radiolabeled bisphosphonates is of great importance in the management of these patients; however, its main drawback is its low overall accuracy, due to the nonspecific uptake in sites of increased bone turnover. Positron-emitting radiopharmaceuticals, such as fluorine-18-fluorodeoxyglucose, choline-derived drugs (fluorine-18-fluorocholine and carbon-11-choline and sodium fluorine-18-fluoride, are increasingly used in clinical practice to detect metastatic spread, and particularly bone involvement, in patients with prostate cancer, to reinforce or substitute information provided by bone scan. Each radiopharmaceutical has a specific mechanism of uptake; therefore, diagnostic performances may differ from one radiopharmaceutical to another on the same lesions, as demonstrated in the literature, with variable sensitivity, specificity, and overall accuracy values in the same patients. Whether bone scintigraphy can be substituted by these new methods is a matter of debate. However, greater radiobiological burden, higher costs, and the necessity of an in-site cyclotron limit the use of these positron emission tomography methods as first-line investigations in patients with prostate cancer

  20. Applications of Beta Particle Detection for Synthesis and Usage of Radiotracers Developed for Positron Emission Tomography

    Science.gov (United States)

    Dooraghi, Alex Abreu

    Positron Emission Tomography (PET) is a noninvasive molecular imaging tool that requires the use of a radioactive compound or radiotracer which targets a molecular pathway of interest. We have developed and employed three beta particle radiation detection systems to advance PET. Specifically, the goals of these systems are to: 1. Automate dispensing of solutions containing a positron emitting isotope. 2. Monitor radioactivity on-chip during synthesis of a positron emitting radiotracer. 3. Assay cellular uptake on-chip of a positron emitting radiotracer. Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing an optimum environment for radiation workers, but also to ensure a quantitatively accurate workflow. For the first project, we describe the development and performance of a system for automated radioactivity distribution of beta particle emitting radioisotopes such as fluorine-18 (F-18). Key to the system is a radiation detector in-line with a peristaltic pump. The system demonstrates volume accuracy within 5 % for volumes of 20 muL or greater. When considering volumes of 20 muL or greater, delivered radioactivity is in agreement with the requested radioactivity as measured with the dose calibrator. The integration of the detector and pump leads to a flexible system that can accurately dispense solutions containing F-18 in radioactivity concentrations directly produced from a cyclotron (~ 0.1-1 mCi/muL), to low activity concentrations intended for preclinical mouse scans (~ 1-10 muCi/muL), and anywhere in between. Electrowetting on dielectric (EWOD) is an attractive microfluidic platform for batch synthesis of PET radiotracers. Visualization of radioisotopes on-chip is critical for synthesis optimization and technological development. For the second project, we describe the development and performance of a Cerenkov/real-time imaging system for PET radiotracer synthesis on EWOD. We also investigate

  1. Guidelines and recommendations for practices of their clinical use of standards of compounds labeled with positron emitting radionuclides approved as established techniques. 2009 revision

    International Nuclear Information System (INIS)

    The recent advancement and prevalance of clinical application of positron emission tomography (PET) have forced us to review previous manuscript of Standards of compounds labeled with positron emitting radionuclides approved as established techniques for medical use and recommendations on practices of their clinical use'. Subcommittee on Medical Application of Positron Emitting Radionuclides of Medical Science and Pharmaceutical Committee in Japan Radioisotope Association has reviewed standards and recommendations for clinical use. Similar to the previous version of recommendations on practices of clinical use, this version includes 'clinical purpose', 'principle of measurement', 'methods of administration', and 'radiation exposure' of particular PET pharmaceuticals. This version includes 12 PET ligands that have been already approved as 'compounds labeled with positron emitting radionuclides as established techniques for medical use' in the committee (18fluorodeoxyglucose (18FDG), 15O-oxygen, 15O-carbon monoxide, 15O-carbon dioxide, 11C-monoxide, 13N-nitrogen, 13N-ammonia, 15O-water, 11C-L-methionine, 11C-sodium acetate, 11C-N-methylspiperone and 11C-choline), and three newly approved compounds (18F-sodium fluoride, 11C-raclopride, and 11C-flumazenil) which have been required for clinical use in many medical institutes. Each medical institute should have a committee and establish internal system to account for conducting clinical use of radiolabeled compounds. (author)

  2. Radiopharmaceuticals in positron emission tomography: Radioisotope productions and radiolabelling procedures at the Austin and Repatriation Medical Centre

    Energy Technology Data Exchange (ETDEWEB)

    Tochon-Danguy, H.J.; Sachinidis, J.I.; Chan, J.G.; Cook, M. [Austin and Repatriation Medical Centre, Melbourne, VIC (Australia). Centre for Positron Emission Tomography

    1997-10-01

    Positron Emission Tomography (PET) is a technique that utilizes positron-emitting radiopharmaceuticals to map the physiology, biochemistry and pharmacology of the human body. Positron-emitting radioisotopes produced in a medical cyclotron are incorporated into compounds that are biologically active in the body. A scanner measures radioactivity emitted from a patient`s body and provides cross-sectional images of the distribution of these radiolabelled compounds in the body. It is the purpose of this paper to review the variety of PET radiopharmaceuticals currently produced at the Austin and Repatriation Medical Centre in Melbourne. Radioisotope production, radiolabelling of molecules and quality control of radiopharmaceuticals will be discussed. A few examples of their clinical applications will be shown as well. During the last five years we achieved a reliable routine production of various radiopharmaceuticals labelled with the four most important positron-emitters: oxygen-15 (t,{sub 1/2}=2min), nitrogen-13 (t{sub 1/2}= 10 min), carbon-11 (t{sub 1/2}=20 min) and fluorine-18 (t{sub 1/2}= 110 min). These radiopharmaceuticals include [{sup 15}O]oxygen, [{sup 15}O]carbon monoxide, [{sup 15}O]carbon dioxide, [{sup 15}O]water, [{sup 13}N]ammonia, [{sup 11}C]flumazenil, [{sup 11}C]SCH23390, [{sup 18}F]fluoromisonidazole and [{sup 18}F]fluoro-deoxy-glucose ([{sup 18}F]FDG). In addition, since the half life of [{sup 18}F] is almost two hours, regional distribution can be done, and the Austin and Repatriation Medical Centre is currently supplying [{sup 18}F]FDG in routine to other hospitals. Future new radiopharmaceuticals development include a [{sup 18}F]thymidine analog to measure cell proliferation and a [{sup 11}C]pyrroloisoquinoline to visualize serotonergic neuron abnormalities. (authors) 23 refs., 2 tabs.

  3. Persistence of cerebral metabolic abnormalities in chronic schizophrenia as determined by positron emission tomography

    International Nuclear Information System (INIS)

    Local cerebral metabolic rates were determined by positron emission tomography and the deoxyglucose method in a group of 10 chronic schizophrenic subjects before and after somatic treatment and in eight normal subjects. Before treatment, schizophrenic subjects had markedly lower absolute metabolic activity than did normal controls in both frontal and temporal regions and a trend toward relative hyperactivity in the basal ganglia area. After treatment, their metabolic rates approached those seen in normal subjects in nearly all regions except frontal. Persistence of diminished frontal metabolism was manifested as significant relative hypofrontality. These findings suggest specific loci of aberrant cerebral functioning in chronic schizophrenia and the utility of positron emission tomography in characterizing these abnormalities

  4. The electronics system for the LBNL positron emission mammography (PEM) camera

    CERN Document Server

    Moses, W W; Baker, K; Jones, W; Lenox, M; Ho, M H; Weng, M

    2001-01-01

    Describes the electronics for a high-performance positron emission mammography (PEM) camera. It is based on the electronics for a human brain positron emission tomography (PET) camera (the Siemens/CTI HRRT), modified to use a detector module that incorporates a photodiode (PD) array. An application-specified integrated circuit (ASIC) services the photodetector (PD) array, amplifying its signal and identifying the crystal of interaction. Another ASIC services the photomultiplier tube (PMT), measuring its output and providing a timing signal. Field-programmable gate arrays (FPGAs) and lookup RAMs are used to apply crystal-by-crystal correction factors and measure the energy deposit and the interaction depth (based on the PD/PMT ratio). Additional FPGAs provide event multiplexing, derandomization, coincidence detection, and real-time rebinning. Embedded PC/104 microprocessors provide communication, real-time control, and configure the system. Extensive use of FPGAs make the overall design extremely flexible, all...

  5. Scar or recurrent rectal cancer. Positron emission tomography is more helpful for diagnosis than immunoscintigraphy

    International Nuclear Information System (INIS)

    We used positron emission tomography and fludeoxyglucose F-18 to assess metabolic activity of a pelvic mass in 18 patients who had suspected recurrent rectal cancer. Computed tomography could not differentiate tumor from scar. All patients presenting increased uptake of fludeoxyglucose F 18 by the mass were proved by histologic studies to suffer from recurrent tumor. Six of seven patients with low fludeoxyglucose uptake had nonmalignant lesions. Using immunoscintigraphy in 14 patients with elevated carcinoembryonic antigen levels, only four of ten recurrences could be identified by increased antibody accumulation in the mass. On the other hand, two of four benign lesions were interpreted as being recurrent tumor because of high uptake. Therefore, only positron emission tomography seems to be a useful diagnostic tool in the differentiation of recurrent rectal cancer and scar by providing information about the metabolic activity of a mass

  6. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    International Nuclear Information System (INIS)

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions

  7. An 8×8 Row-Column Summing Readout Electronics for Preclinical Positron Emission Tomography Scanners

    OpenAIRE

    Shih, Y. C.; Sun, F. W.; MacDonald, L R; Otis, B. P.; Miyaoka, R S; McDougald, W.; Lewellen, T K

    2009-01-01

    This work presents a row/column summing readout electronics for an 8×8 silicon photomultiplier array. The summation circuit greatly reduces the number of electronic channels, which is desirable for pursuing higher resolution positron emission tomography scanners. By using a degenerated common source topology in the summation circuit, more fan-in is possible and therefore a greater reduction in the number of electronic channels can be achieved. The timing signal is retrieved from a common anod...

  8. Dynamic Positron Emission Tomography Image Restoration via a Kinetics-Induced Bilateral Filter

    OpenAIRE

    Bian, Zhaoying; Huang, Jing; Ma, Jianhua; Lu, Lijun; Niu, Shanzhou; Zeng, Dong; Feng, Qianjin; Chen, Wufan

    2014-01-01

    Dynamic positron emission tomography (PET) imaging is a powerful tool that provides useful quantitative information on physiological and biochemical processes. However, low signal-to-noise ratio in short dynamic frames makes accurate kinetic parameter estimation from noisy voxel-wise time activity curves (TAC) a challenging task. To address this problem, several spatial filters have been investigated to reduce the noise of each frame with noticeable gains. These filters include the Gaussian f...

  9. Noninvasive measurement of regional myocardial glucose metabolism by positron emission computed tomography. [Dogs

    Energy Technology Data Exchange (ETDEWEB)

    Schelbert, H.R.; Phelps, M.E.

    1980-06-01

    While the results of regional myocardial glucose metabolism measurements using positron emission computed tomography (/sup 13/N-ammonia) are promising, their utility and value remains to be determined in man. If this technique can be applied to patients with acute myocardial ischemia or infarction it may permit delineation of regional myocardial segments with altered, yet still active metabolism. Further, it may become possible to evaluate the effects of interventions designed to salvage reversibly injured myocardium by this technique.

  10. Value of positron emission tomography in diagnosing synchronous penile metastasis from urothelial bladder cancer

    OpenAIRE

    Rouanne, M.; Alhammadi, A.; Vilain, D.; Radulescu, C.; Lebret, T.

    2015-01-01

    Metastases to the penis are extremely rare events. Most frequently, penile metastases come from the urogenital system (bladder, prostate) or the rectum-sigmoid colon. Usually painful, penile lesions may be asymptomatic, making diagnosis more challenging. Hence, we report the adding value of 18F-fludeoxyglucose–positron emission tomography/computed tomography (18F-FDG PET/CT) in the detection of penile metastases originating from urothelial carcinoma of the bladder. Arguably, penile metastases...

  11. [(18)F]Fluoroethyltyrosine- positron emission tomography-guided radiotherapy for high-grade glioma

    OpenAIRE

    Ratib Osman; Dipasquale Giovanna; Nouet Philippe; Rouzaud Michel; Haller Guy; Casanova Nathalie; Buchegger Franz; Zilli Thomas; Weber Damien C; Zaidi Habib; Vees Hansjorg; Miralbell Raymond

    2008-01-01

    Abstract Background To compare morphological gross tumor volumes (GTVs), defined as pre- and postoperative gadolinium enhancement on T1-weighted magnetic resonance imaging to biological tumor volumes (BTVs), defined by the uptake of 18F fluoroethyltyrosine (FET) for the radiotherapy planning of high-grade glioma, using a dedicated positron emission tomography (PET)-CT scanner equipped with three triangulation lasers for patient positioning. Methods Nineteen patients with malignant glioma were...

  12. Positron emission tomography in cases of chorea with different underlying diseases.

    OpenAIRE

    Hosokawa, S.; Ichiya, Y; Kuwabara, Y; Ayabe, Z; Mitsuo, K; Goto, I; Kato, M.

    1987-01-01

    Local cerebral metabolic rate for glucose (LCMRglc) was measured with positron emission tomography using the 18F-fluorodeoxy-glucose method in five patients with chorea due to different underlying diseases. Hypometabolism was observed in the striatum bilaterally in patients with Huntington's disease, choreoacanthocytosis, sporadic progressive chorea and dementia, and pseudo-Huntington form of dentato-rubro-pallido-luysian atrophy (DRPLA). The patient with hemichorea showed hypometabolism in t...

  13. Noninvasive measurement of regional myocardial glucose metabolism by positron emission computed tomography

    International Nuclear Information System (INIS)

    While the results of regional myocardial glucose metabolism measurements using positron emission computed tomography (13N-ammonia) are promising, their utility and value remains to be determined in man. If this technique can be applied to patients with acute myocardial ischemia or infarction it may permit delineation of regional myocardial segments with altered, yet still active metabolism. Further, it may become possible to evaluate the effects of interventions designed to salvage reversibly injured myocardium by this technique

  14. Photo-Detectors for Time of Flight Positron Emission Tomography (ToF-PET)

    OpenAIRE

    Levin, Craig S; Virginia Ch. Spanoudaki

    2010-01-01

    We present the most recent advances in photo-detector design employed in time of flight positron emission tomography (ToF-PET). PET is a molecular imaging modality that collects pairs of coincident (temporally correlated) annihilation photons emitted from the patient body. The annihilation photon detector typically comprises a scintillation crystal coupled to a fast photo-detector. ToF information provides better localization of the annihilation event along the line formed by each detector pa...

  15. The electronics system for the LBNL positron emission tomography (PEM) camera

    OpenAIRE

    Moses, W. W.; Young, J.W.; Baker, K.; Jones, W; Lenox, M.; Ho, M. H.; Weng, M.

    2000-01-01

    We describe the electronics for a high performance Positron Emission Mammography (PEM) camera. It is based on the electronics for a human brain PET camera (the Siemens/CTI HRRT), modified to use a detector module that incorporates a photodiode (PD) array. An ASIC services the PD array, amplifying its signal and identifying the crystal of interaction. Another ASIC services the photomultiplier tube (PMT), measuring its output and providing a timing signal. Field programmable gate arrays (...

  16. Gliomatosis cerebri mimicking encephalitis evaluated using fluorine-18 fluorodeoxyglucose: Positron emission tomography/computed tomography

    International Nuclear Information System (INIS)

    Gliomatosis cerebri (GC) is a rare condition in which an infiltrative glial neoplasm spreads through the brain with preservation of the underlying structure. F-18 fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has an important role in demonstrating the appropriate metabolism and differentiating pathologies mimicking GC on CT and magnetic resonance imaging. We describe imaging findings of FDG PET/CT in GC in a 9-year-old male child mimicking encephalitis

  17. The establishment of crystal position look-up table for positron emission tomography with block detectors

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A method has been developed to establish the crystal position look-up table for positron emission tomography with block detectors. It is based on the principle that the counts in crystal position histogram obey the Gaussian mixture model (GMM). This method has taken full consideration of the characteristics of the GMM and the detector itself. The experimental results have proved that it is simple, reliable, and universal.

  18. Regional structure-function correlations in chronic obstructive lung disease measured with positron emission tomography.

    OpenAIRE

    Brudin, L H; Rhodes, C G; Valind, S O; Buckingham, P D; Jones, T; Hughes, J. M.

    1992-01-01

    BACKGROUND: Positron emission tomography, performed with isotopes of very short half life, can be used to relate local lung tissue density to local ventilation and to the ventilation:perfusion ratio. This method has been used in 10 patients with severe chronic airflow obstruction and differing values for carbon monoxide transfer factor (TLCO) and transfer coefficient (KCO). METHODS: Ventilation (VA) and the ventilation:perfusion ratio (V/Q), lung density, and blood volume were measured region...

  19. Usefulness of myocardial positron emission tomography/nuclear imaging in Takotsubo cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    Marzia; Testa; Mauro; Feola

    2014-01-01

    AIM:To analyse and summarize all the articles related to positron emission tomography and Takotsubo cardiomyopathy(TTC).METHODS:We performed a systematic review of the existing literature on positron emission tomography/nuclear imaging and Takotsubo cardiomyopathy using PUBMED database.We combined search terms such as"takotsubo","takotsubo syndrome","myocardial positron emission tomography","positron emission tomography".All case reports were excluded.The list included only four articles which were reviewed by two independent investigators.It was not possible to undertake a formal meta-analysis because of the heterogeneity of the studies;therefore,we made a narrative synthesis of the collected data.RESULTS:Nuclear medicine techniques can be useful employed in the differential diagnosis of TTC from an acute coronary syndrome(ACS).In fact,transient left ventricular(LV)apical ballooning is a syndrome frequently misdiagnosed as an ACS and can mimic symptoms of myocardial infarction with ST-T segments changes on electrocardiography(ECG),a limited re-lease of myocardial enzyme,mainly reported after sudden emotional or physical stress,and an akinesis or dyskinesis of the left ventricle apex which are completely reversible in a few weeks.In the studies included in this review,nuclear medicine techniques have demonstrated a discrepancy between normal perfusion and a reduced glucose utilization in TTC,commonly known as"inverse flow metabolism mismatch".This suggests that apical ballooning represents a transient metabolic disorder on the cellular level,rather than a structural contractile disease of the myocardium,due to a transient decrease of glucose metabolism that might be related to a coronary microcirculation impairment followed by prolonged myocardial stunning.CONCLUSION:Nuclear medicine techniques can be usefully used for the diagnosis of TTC and can increase our knowledge of the pathophysiological mechanisms of TTC.

  20. Exogenous lipoid pneumonia with unusual CT pattern and FDG positron emission tomography scan findings

    International Nuclear Information System (INIS)

    We report a case of an exogenous lipoid pneumonia that appeared as a spiculated calcified mass on CT scan in which a positron emission tomography (PET) scan was performed before histological analysis. The F-18 fluoro-deoxy-D-glucose (FDG) PET showed a pattern highly suggestive of malignancy which, to our knowledge, has not yet been described. Similar to inflammatory and infectious lung diseases, lipoid pneumonia may be a false-positive case of F-18 FDG uptake. (orig.)

  1. Exogenous lipoid pneumonia with unusual CT pattern and FDG positron emission tomography scan findings

    Energy Technology Data Exchange (ETDEWEB)

    Tahon, Florence; Berthezene, Yves; Blineau, Nadine; Marchand, Bruno [Department of Radiology, Hopital de la Croix-Rousse, 103 grande rue de la Croix-Rousse, 69317 Lyon Cedex (France); Hominal, Stephane; Guerin, Jean-Claude [Department of Chest, Hopital de la Croix-Rousse, 103 grande rue de la Croix-Rousse, 69317 Lyon Cedex (France); Cinotti, Luc [CERMEP, 59 bd Pinel, 69003 Lyon Cedex (France)

    2002-07-01

    We report a case of an exogenous lipoid pneumonia that appeared as a spiculated calcified mass on CT scan in which a positron emission tomography (PET) scan was performed before histological analysis. The F-18 fluoro-deoxy-D-glucose (FDG) PET showed a pattern highly suggestive of malignancy which, to our knowledge, has not yet been described. Similar to inflammatory and infectious lung diseases, lipoid pneumonia may be a false-positive case of F-18 FDG uptake. (orig.)

  2. Imaging Chronic Pain and Inflammation : Positron Emission Tomography Studies of Whiplash Associated Disorder

    OpenAIRE

    Linnman, Clas

    2008-01-01

    This thesis is on chronic neck pain after a rear impact car injury, so called whiplash associated disorder (WAD). Three empirical studies using positron emission tomography (PET) with different radioligands have been performed. The first study evaluated resting state regional cerebral blood flow (rCBF) in WAD patients and in healthy, pain-free controls, by use of oxygen-15 labeled water. Patients had heightened resting rCBF bilaterally in the posterior parahippocampal and the posterior cingul...

  3. Identifying active vascular micro-calcification by 18F-sodium fluoride positron emission tomography

    OpenAIRE

    Irkle, Agnese; Vesey, Alex T.; Lewis, David Y.; Jeremy N Skepper; Bird, Joseph L. E.; Dweck, Marc R; Joshi, Francis R.; Gallagher, Ferdia A.; Warburton, Elizabeth A; Bennett, Martin R; Kevin M. Brindle; Newby, David E; Rudd, James H.; Davenport, Anthony P.

    2015-01-01

    Vascular calcification is a complex biological process that is a hallmark of atherosclerosis. While macrocalcification confers plaque stability, microcalcification is a key feature of high-risk atheroma and is associated with increased morbidity and mortality. Positron emission tomography and X-ray computed tomography (PET/CT) imaging of atherosclerosis using 18F-sodium fluoride (18F-NaF) has the potential to identify pathologically high-risk nascent microcalcification. However, the precise m...

  4. Identifying active vascular microcalcification by (18)F-sodium fluoride positron emission tomography

    OpenAIRE

    Irkle, Agnese; Vesey, Alex T.; Lewis, David Y.; Jeremy N Skepper; Bird, Joseph L. E.; Dweck, Marc R; Joshi, Francis R.; Gallagher, Ferdia A.; Warburton, Elizabeth A; Bennett, Martin R; Kevin M. Brindle; Newby, David E; Rudd, James H.; Davenport, Anthony P.

    2015-01-01

    Vascular calcification is a complex biological process that is a hallmark of atherosclerosis. While macrocalcification confers plaque stability, microcalcification is a key feature of high-risk atheroma and is associated with increased morbidity and mortality. Positron emission tomography and X-ray computed tomography (PET/CT) imaging of atherosclerosis using (18)F-sodium fluoride ((18)F-NaF) has the potential to identify pathologically high-risk nascent microcalcification. However, the preci...

  5. Brain Imaging with Positron Emission Tomography: Quantification and Biomedical Applications in Alzheimer's Disease and Brain Tumors

    OpenAIRE

    Wardak, Mirwais

    2013-01-01

    Positron emission tomography (PET) is a unique and powerful imaging technique that is used to visualize and quantify various biological processes in living subjects in health and disease. PET imaging can also provide biological information for the assessment of therapies. In this dissertation, we will cover three projects that utilize the quantitative capability of PET for studying two neurological disorders: Alzheimer's disease and brain tumors.One of the goals in PET imaging is to produce...

  6. Transcutaneous measurement of the arterial input function in positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) provides a powerful tool in medical research. Biochemical function can be both precisely localized and quantitatively measured. To achieve reliable quantitation it is necessary to know the time course of activity concentration in the arterial blood during the measurement. In this study the arterial blood curve from the brachial artery is compared to the activity measured in the internal carotid artery with a new transcutaneous detector

  7. Elevated Brain Cannabinoid CB1 Receptor Availability in Posttraumatic Stress Disorder: A Positron Emission Tomography Study

    OpenAIRE

    Neumeister, Alexander; Normandin, Marc D.; Pietrzak, Robert H.; Piomelli, Daniele; Zheng, Ming-Qiang; Gujarro-Anton, Ana; Potenza, Marc N.; Bailey, Christopher R.; Lin, Shu-fei; Najafzadeh, Soheila; Ropchan, Jim; Henry, Shannan; Corsi-Travali, Stefani; Carson, Richard E; Huang, Yiyun

    2013-01-01

    Endocannabinoids and their attending cannabinoid type 1 receptor (CB1) have been implicated in animal models of posttraumatic stress disorder (PTSD). However, their specific role has not been studied in people with PTSD. Herein, we present an in vivo imaging study using positron emission tomography (PET) and the CB1-selective radioligand [11C]OMAR in individuals with PTSD, and healthy controls with lifetime histories of trauma (trauma controls [TC]) and those without such histories (healthy c...

  8. Human hemispheric infarction studied by positron emission tomography and the 15O continuous inhalation technique

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) offers an entirely new approach to the study of the pathophysiology of cerebral ischemic disorders. For the first time it is possible to obtain functional tomographic images that represent cerebral perfusion and metabolism on a regional basis. We report here a study of cerebral blood flow and oxygen extraction by means of the 15O inhalation technique in a large number of human hemispheric infarctions. (orig.)

  9. Synthesis of Novel Neutrophil-Specific Imaging Agents for Positron Emission Tomography (PET) Imaging

    OpenAIRE

    ZHANG Yi; Kundu, Bijoy; Fairchild, Karen D.; Locke, Landon; Berr, Stuart S.; Linden, Joel; Pan, Dongfeng

    2007-01-01

    A neutrophil specific peptide, cinnamoyl-F(D)LF(D)LFK (cFLFLFK), was conjugated consecutively with a polyethylene glycol moiety (3.4 K) and 2,2′,2″,2‴-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid (DOTA) to form cFLFLFK-PEG-DOTA. After 64Cu labeling, Positron Emission Tomography (PET) imaging was successfully able to detect mouse lung inflammation.

  10. Dynamic positron emission tomography in man using small bismuth germanate crystals

    International Nuclear Information System (INIS)

    Primary considerations for the design of positron emission tomographs for medical studies in humans are the need for high imaging sensitivity, whole organ coverage, good spatial resolution, high maximum data rates, adequate spatial sampling with minimum mechanical motion, shielding against out of plane activity, pulse height discrimination against scattered photons, and timing discrimination against accidental coincidences. We discuss the choice of detectors, sampling motion, shielding, and electronics to meet these objectives

  11. Combined use of positron emission tomography and volume doubling time in lung cancer screening with low-dose CT scanning

    DEFF Research Database (Denmark)

    Ashraf, H; Dirksen, A; Jakobsen, Annika Loft;

    2011-01-01

    In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules....

  12. Assessment of regional myocardial and renal blood flow with copper-PTSM and positron emission tomography.

    Science.gov (United States)

    Shelton, M E; Green, M A; Mathias, C J; Welch, M J; Bergmann, S R

    1990-09-01

    We recently demonstrated in isolated, perfused hearts that radiolabeled pyruvaldehyde bis(N4-methylthiosemicarbazonato)copper(II) (Cu-PTSM) is well extracted throughout a range of conditions including ischemia, hypoxia, and hyperemia. Once extracted, binding of radioactivity by the isolated heart was essentially irreversible, giving this tracer microspherelike qualities. Because Cu-PTSM can be readily prepared with the generator-produced positron-emitting copper 62 and other gamma- or positron-emitting copper radionuclides, we evaluated its usefulness for measuring regional myocardial and renal blood flow in vivo in intact dogs at rest, after ischemia, or after coronary hyperemia was induced by intravenous administration of dipyridamole. After intravenous administration of radiolabeled Cu-PTSM, the tracer cleared rapidly from the blood. Myocardial uptake of single photon-emitting 67Cu-labeled Cu-PTSM was measured directly in myocardial samples 15 minutes after tracer administration, and it increased proportionally with blood flow throughout the flow range (estimated concomitantly with radiolabeled microspheres) of 0.0-6.0 ml/g/min (n = 340 samples from 17 dogs, r = 0.99, Ycopper radioactivity = 85Xmicrosphere flow -7 chi 2 + 17). Renal uptake of radiolabeled Cu-PTSM was also proportional to blood flow. Positron emission tomography was performed in four intact dogs after intravenous administration of 64Cu-labeled Cu-PTSM (19% positron decay, t1/2 = 12.8 hours). High-quality images of heart and kidney were obtained. Accordingly, radiolabeled Cu-PTSM should be a useful, generator-produced tracer for estimating regional myocardial and renal blood flow with positron emission tomography. PMID:2394015

  13. What have positron emission tomography and 'Zippy' told us about the neuropharmacology of drug addiction?

    Science.gov (United States)

    Cumming, Paul; Caprioli, Daniele; Dalley, Jeffrey W

    2011-08-01

    Translational molecular imaging with positron emission tomography (PET) and allied technologies offer unrivalled applications in the discovery of biomarkers and aetiological mechanisms relevant to human disease. Foremost among clinical PET findings during the past two decades of addiction research is the seminal discovery of reduced dopamine D(2/3) receptor expression in the striatum of drug addicts, which could indicate a predisposing factor and/or compensatory reaction to the chronic abuse of stimulant drugs. In parallel, recent years have witnessed significant improvements in the performance of small animal tomographs (microPET) and a refinement of animal models of addiction based on clinically relevant diagnostic criteria. This review surveys the utility of PET in the elucidation of neuropharmacological mechanisms underlying drug addiction. It considers the consequences of chronic drug exposure on regional brain metabolism and neurotransmitter function and identifies those areas where further research is needed, especially concerning the implementation of PET tracers targeting neurotransmitter systems other than dopamine, which increasingly have been implicated in the pathophysiology of drug addiction. In addition, this review considers the causal effects of behavioural traits such as impulsivity and novelty/sensation-seeking on the emergence of compulsive drug-taking. Previous research indicates that spontaneously high-impulsive rats--as exemplified by 'Zippy'--are pre-disposed to escalate intravenous cocaine self-administration, and subsequently to develop compulsive drug taking tendencies that endure despite concurrent adverse consequences of such behaviour, just as in human addiction. The discovery using microPET of pre-existing differences in dopamine D(2/3) receptor expression in the striatum of high-impulsive rats suggests a neural endophenotype that may likewise pre-dispose to stimulant addiction in humans. PMID:20846139

  14. Evaluation of recurrent gastric malignancy with [F-18]-FDG positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jadvar, H.; Tatlidil, R.; Garcia, A.A.; Conti, P.S

    2003-03-01

    AIM: We retrospectively assessed the use of [{sup 18}F] fluorodeoxyglucose positron emission tomography (FDG PET) in the evaluation of recurrent disease in patients with history of gastric malignancy. MATERIALS AND METHODS: Eighteen patients were referred for FDG PET for evaluation of recurrent gastric cancer. Prior treatments included total (n=4) or partial gastrectomy (n=14) followed by chemotherapy alone (n=7) or combined chemoradiation therapy (n=2). The interval between the most recent treatment and PET ranged from 3 months to 2 years. Correlative diagnostic data were available in 16 patients and were all obtained within 3 months of the PET study. Validation was by clinical or imaging follow-up (2-45 months) in 16 patients and histology in two patients. RESULTS: PET was concordant with computed tomography (CT) in 12 patients (5 TP, 6 TN, 1 FN). In one patient with negative imaging studies, an incidental finding of left obstructive uropathy was determined to be due to metastatic ureteral stricture. Discordant imaging findings were present in four patients (22% of total). PET-detected diffuse metastatic lesions in three of these patients with rising serum tumour markers while other imaging studies were negative. Additional chemotherapy was initiated in these three patients (17% of total) based on PET localization of disease. PET and a gastric anastomosis biopsy were negative in another patient with positive CT. The remaining two patients without correlative imaging studies died shortly after positive PET studies with presumed recurrent cancer. CONCLUSION: FDG PET may be useful in the evaluation of recurrent gastric cancer, and can localize the disease when CT is non-diagnostic. Imaging evaluation with PET may also impact on the clinical management of patients with recurrent gastric cancer.

  15. Positron emission tomography for diagnosis of Alzheimer's disease and vascular dementia

    International Nuclear Information System (INIS)

    In mild or atypical cases of Alzheimer's disease (AD) the differential diagnosis to other dementing diseases, such as vascular dementia (VD), may pose a difficult problem. Beside computed tomography (CT) and magnetic resonance imaging (MRI), functional neuroimaging by positron emission tomography (PET). Support the clinical diagnosis by visualizing cerebral function. PET of 18F-2-fluoro-2-deoxy-D-glucose (FDG) for measurement of regional cerebral glucose metabolism (rCMRGl) has shown a typical metabolic pattern in patients with probable AD: hypometabolism in temporoparietal and frontal association areas, but relative recessing of primary cortical areas, basal ganglia and cerebellum. In VD a different pattern is seen. It consists of scattered areas with reduction of rCMRGl typically extending over cortical and subcortical structures. Severity of dementia is correlated with rCMRGl reduction in the temporoparietal association cortex, irrespective of the cause of dementia. Also the total volume of hypometabolic regions is related to severity of dementia but did not differ between AD and VD, even in patients with small lacunar infarction. This indicates that the total volume of functional tissue loss is more important, since it also includes the effects of incompletely infarcted tissue and morphologically intact but deafferented cortex. The characteristic metabolic pattern has a high diagnostic accuracy for the discrimination between probable AD, normals and VD, even in patients with mild cognitive impairment. Under clinical and therapeutic aspects the analysis of longitudinal changes of rCMRGl has shown that neuropsychological and metabolic changes are closely related in both, AD and VD. (author)

  16. Fluorine-18 fluorodeoxyglucose positron emission tomography in infectious bone diseases: results of histologically confirmed cases

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the clinical use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in acute and chronic osteomyelitis and inflammatory spondylitis. The study population comprised 21 patients suspected of having acute or chronic osteomyelitis or inflammatory spondylitis. Fifteen of these patients subsequently underwent surgery. FDG-PET results were correlated with histopathological findings. The remaining six patients, who underwent conservative therapy, were excluded from any further evaluation due to the lack of histopathological data. The histopathological findings revealed osteomyelitis or inflammatory spondylitis in all 15 patients: seven patients had acute osteomyelitis and eight patients had chronic osteomyelitis or inflammatory spondylitis. FDG-PET yielded 15 true-positive results. The tracer uptake correlated with the histopathological findings in each case. Bone scintigraphy performed in 11 patients yielded ten true-positive results and one false-negative result. Follow-up carried out on two patients revealed normal or clearly reduced tracer uptake, which correlated with a normalisation of clinical data. In early postoperative follow-up it was impossible to differentiate between postsurgical reactive changes and further infection using FDG-PET. It is concluded that acute and chronic osteomyelitis of the peripheral as well as the central skeleton can be detected using FDG-PET. Osteomyelitis can be differentiated from soft tissue infection surrounding the bone. Unlike computed tomography and magnetic resonance imaging, FDG-PET is not affected by metal implants used for fixing fractures. FDG-PET demonstrated promising initial results with respect to treatment monitoring. Nevertheless, in the early postoperative phase FDG-PET seems to be of limited value owing to unspecific tracer uptake. (orig.)

  17. Fluorine-18 fluorodeoxyglucose positron emission tomography in infectious bone diseases: results of histologically confirmed cases

    Energy Technology Data Exchange (ETDEWEB)

    Kaelicke, T. [Dept. of Surgery, University of Bochum (Germany); Schmitz, A.; Schmitt, O. [Dept. of Orthopaedics, University of Bonn (Germany); Risse, J.H.; Biersack, H.J. [Dept. of Nuclear Medicine, University of Bonn (Germany); Arens, S.; Hansis, M. [Dept. of Trauma Surgery, University of Bonn (Germany); Keller, E. [Department of Radiology, University of Bonn (Germany); Gruenwald, F. [Department of Nuclear Medicine, University of Frankfurt/Main (Germany)

    2000-05-01

    The aim of this study was to evaluate the clinical use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in acute and chronic osteomyelitis and inflammatory spondylitis. The study population comprised 21 patients suspected of having acute or chronic osteomyelitis or inflammatory spondylitis. Fifteen of these patients subsequently underwent surgery. FDG-PET results were correlated with histopathological findings. The remaining six patients, who underwent conservative therapy, were excluded from any further evaluation due to the lack of histopathological data. The histopathological findings revealed osteomyelitis or inflammatory spondylitis in all 15 patients: seven patients had acute osteomyelitis and eight patients had chronic osteomyelitis or inflammatory spondylitis. FDG-PET yielded 15 true-positive results. The tracer uptake correlated with the histopathological findings in each case. Bone scintigraphy performed in 11 patients yielded ten true-positive results and one false-negative result. Follow-up carried out on two patients revealed normal or clearly reduced tracer uptake, which correlated with a normalisation of clinical data. In early postoperative follow-up it was impossible to differentiate between postsurgical reactive changes and further infection using FDG-PET. It is concluded that acute and chronic osteomyelitis of the peripheral as well as the central skeleton can be detected using FDG-PET. Osteomyelitis can be differentiated from soft tissue infection surrounding the bone. Unlike computed tomography and magnetic resonance imaging, FDG-PET is not affected by metal implants used for fixing fractures. FDG-PET demonstrated promising initial results with respect to treatment monitoring. Nevertheless, in the early postoperative phase FDG-PET seems to be of limited value owing to unspecific tracer uptake. (orig.)

  18. Synthesis of small molecules via click chemistry for positron emission tomography (PET) imaging of tumor integrin αvβ3 and/or α5β1 expression

    OpenAIRE

    Monaco, Alessandra

    2013-01-01

    Positron emission tomography (PET) is the most sensitive imaging technology in nuclear medicine to measure biological and physiological process in vivo, with many applications in clinical areas such as oncology, neuropsychiatry and cardiology. The most common radionuclides for the production of radiopharmaceuticals are 11C, 13N, 14O and 18F, which are easily introduced in biomolecules. Of them 18F is the most used positron emitting radionuclides because of its half-life of 110 min which makes...

  19. Tomography by positrons emission: integral unit to the service of Mexico; Tomografia por emision de positrones: unidad integral al servicio de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez D, F.A. [Unidad PET-Ciclotron, Facultad de Medicina, UNAM (Mexico)]. e-mail: fred-alonso@correo.unam.mx

    2005-07-01

    The applications of the Positron emission tomography (PET) together with the one radiopharmaceutical 2 - [{sup 18} F]-fluoro-2-deoxy-D-glucose in the area of the medical imaging is expanding quickly and it possesses a bigger impact at the moment in favor of those patient to who suffers an oncological, cardiac or neurological illness in Mexico. (Author)

  20. A positron emission tomography study of nigro-striatal dopaminergic mechanisms underlying attention: implications for ADHD and its treatment

    OpenAIRE

    del Campo, Natalia; Fryer, Tim D; Hong, Young T.; Smith, Rob; Brichard, Laurent; Acosta-Cabronero, Julio; Chamberlain, Samuel R.; Tait, Roger; Izquierdo, David; Regenthal, Ralf; Dowson, Jonathan; Suckling, John; Baron, Jean-Claude; Aigbirhio, Franklin I.; Robbins, Trevor W.

    2013-01-01

    Through the combined use of 18F-fallypride positron emission tomography and magnetic resonance imaging this study examined the neural mechanisms underlying the attentional deficits associated with attention deficit/hyperactivity disorder and their potential reversal with a single therapeutic dose of methylphenidate. Sixteen adult patients with attention deficit/hyperactivity disorder and 16 matched healthy control subjects were positron emission tomography and magnetic resonance imaging scann...

  1. Image findings of monomorphic non-hogdkin lymphoproliferative disorder in a post renal transplant patient diagnosed with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography

    OpenAIRE

    Kamaleshwaran, Koramadai Karuppusamy; Rajasekar, Thirugnanam; Shibu, Deepu; Radhakrishnan, Edathurthy Kalarikal; Shinto, Ajit Sugunan

    2014-01-01

    Post-transplant lymphoproliferative disorder (PTLD) is a heterogeneous group of lymphoid proliferations caused by immunosuppression after solid organ or bone marrow transplantation. PTLD is categorized by early lesion, polymorphic PTLD and monomorphic PTLD. Fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) scans have clinical significance in the evaluation of PTLD following renal transplantation. We report imaging findings of a monomorphic non-H...

  2. 18 Fluoride-fluorodeoxyglucose positron emission tomography in initial staging and response assessment of primary non-Hodgkin lymphoma of the tibia

    International Nuclear Information System (INIS)

    Primary lymphoma of the bone is a rare clinical presentation constituting to <1% of all lymphomas. The long bones are usually involved. Combined treatment with chemotherapy and radiation offers long-term survival. The authors present the role of 18 fluoride-fluorodeoxyglucose positron emission tomography-computerized tomography in initial staging and response assessment in a case of primary diffuse large B cell lymphoma of the tibia

  3. Cancer Research UK procedures in manufacture and toxicology of radiotracers intended for Pre-phase I positron emission tomography studies in cancer patients

    OpenAIRE

    Aboagye, E O; Luthra, S K; Brady, F; Poole, K; Anderson, H.; Jones, T.; Boobis, A; Burtles, S S; Price, P

    2002-01-01

    Radiolabelled compounds formulated for injection (radiopharmaceuticals), are increasingly being employed in drug development studies. These can be used in tracer amounts for either pharmacokinetic or pharmacodynamic studies. Such radiotracer studies can also be carried out early in man, even prior to conventional Phase I clinical testing. The aim of this document is to describe procedures for production and safety testing of oncology radiotracers developed for imaging by positron emission tom...

  4. Detection and Assessment Using Positron Emission Tomography of Genetically Determined Defects in Myocardial Fatty Acid Utilization. Final report, 8/1/93-6/30/97

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, Steven R.

    2000-04-09

    An approach using positron emission tomography (PET) was developed, validated and used to measure myocardial fatty acid metabolism in patients with inherited forms of heart failure. Abnormalities were correlated with the severity of the clinical illness. The approach developed was also shown to identify abnormalities in myocardial fatty acid metabolism in some patients with acquired forms of heart failure. The PET technique thus permits identification of abnormal fatty acid metabolism and provides an approach to evaluate the efficacy of interventional strategies.

  5. Diagnostic and therapeutic impact of whole body positron emission tomography using fluorine-18-fluoro-2-deoxy-D-glucose in children with chronic granulomatous disease

    OpenAIRE

    Gungor, T; Engel-Bicik, I; Eich, G.; Willi, U; Nadal, D; Hossle, J; Seger, R.; Steinert, H

    2001-01-01

    AIMS—To compare whole body positron emission tomography (PET) using fluorine-18-fluoro-2-deoxy-D-glucose (FDG) with computed tomography (CT) in detecting active infective foci in children with chronic granulomatous disease.
METHODS—We performed 22 whole body FDG PET studies in seven children with X linked (n = 6) or autosomal recessive (n = 1) CGD. All had clinical signs of infection and/or were evaluated prior to bone marrow transplantation (BMT). Nineteen PET studies...

  6. Patient radiation protection in positron emission tomography; Proteccion radiologica del paciente en la tomografia por emision de positrones

    Energy Technology Data Exchange (ETDEWEB)

    Marti-Climent, J. M.; Garcia-Velloso, M. J. [Universidad de Navarra. (Spain)

    2003-07-01

    Patient radiation protection in Positron Emission Tomography (PET) is closely related to the correct execution of studies: proper scanner performance, and optimization of both image quality and patient dose. We describe the quality control tests considered as essential: scanner stability, spatial resolution, sensitivity and tomographic uniformity. Knowledge of the dose received by the critical organ and the effective dose for each radiopharmaceutical allows the establishment of strategies for dose optimization. Although a great variety of PET tracers exist, we review the dose produced by F-FDG, the most widely used tracer, and those used in our PET Center O-Water, N-Ammonia, C-Methionine, C-Choline, F-Choline, F-Dopa, and F-FHBG. Reduction of administered activity to the patient is the direct way to reduce the dose. Thus, PET acquisition in the 3D mode, with higher sensitivity, is a determining factor. In order to reduce the dose to different organs, efforts should be directed to the critical organs, mainly the urinary bladder wall. Finally, correct patient preparation improves, PET image quality, due to an optimum tracer uptake, which optimizes the dose to different organs. (Author) 25 refs.

  7. Development of skin surface radiation detector system to monitor radioactivity in arterial blood with positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a unique method to determine quantitatively and localize precisely human physiological functions. The measurement of regional cerebral blood flow (rCBF) is one of the most commonly used clinical PET studies. Two conventional methods are commonly used to measure the time course of activity concentration (TCC) in arterial blood. A new type detector system for measuring the TCC in the arterial blood of a subject in PET study without taking the arterial blood have been developed. The system measures the radioactivity in arterial blood through the skin of a subject. A detector is placed on the skin over a wrist. The block diagram of the detector system is shown. It was tried to measure 15O activity (half life: 122s). The nuclei emit the positrons of maximum energy 1.73 MeV, which has about 9 mm range in tissues, and can penetrate through a skin from an artery. The phantom experiment to examine the performance of the detector system and the clinical PET study and their results are reported. (K.I.)

  8. Positron emission tomography in patients suffering from HIV-1 infection

    International Nuclear Information System (INIS)

    This paper reviews currently available PET studies performed either to improve our understanding of the pathogenesis of HIV-1 infection or to assess the value of PET imaging in the clinical decision making of patients infected with HIV-1 presenting with AIDS-related opportunistic infections and malignancies. FDG PET has shown that HIV-1 infection progresses by distinct anatomical steps, with involvement of the upper torso preceding involvement of the lower part of the torso, and that the degree of FDG uptake relates to viral load. The former finding suggests that lymphoid tissues are engaged in a predictable sequence and that diffusible mediators of activation might be important targets for vaccine or therapeutic intervention strategies. In lipodystrophic HIV-infected patients, limited available data support the hypothesis that stavudine-related lipodystrophy is associated with increased glucose uptake by adipose tissue as a result of the metabolic stress of adipose tissue in response to highly active antiretroviral treatment (HAART). Finally, in early AIDS-related dementia complex (ADC), striatal hypermetabolism is observed, whereas progressive ADC is characterized by a decrease in subcortical and cortical metabolism. In the clinical setting, PET has been shown to allow the differentiation of AIDS-related opportunistic infections and malignancies, and to allow monitoring of side effects of HAART. However, in patients suffering from HIV infection and presenting with extracerebral lymphoma or other human malignancies, knowledge of viraemia is essential when interpreting FDG PET imaging. (orig.)

  9. Positron emission tomography in presurgical evaluation of epilepsy

    International Nuclear Information System (INIS)

    In a considerable proportion of patients with medically intractable partial epilepsies who are considered for surgery, the detection of a lesion with MRI or CT is not possible. Functional imaging methods can provide clinically useful information in these cases, being methods which enable localisation of functional abnormalities independent from EEG. There is an extensive knowledge about interictal PET-investigations with F-18 FDG. Many centers dealing with preoperative evaluation of epilepsy use this method as part of their diagnostic routine. Most studies report a decrease of glucose metabolism in topographic correlation to the EEG defined seizure origin in temporal lobe epilepsy in 70%-85% of the patients. The sensitivity reported for the detection of extratemporal foci is markedly lower. The mapping of neuronal structures with specific ligands, i.e. benzodiazepine receptor ligands has advantages compared to the detection of changes in flow and metabolism. It enables the differentiation of abnormalities in the neuronal texture of the brain from deactivated cortical areas. This is especially important when surgical procedures other than standard resection techniques are considered. The clinical importance of the functional imaging methods is that they help to decrease the amount of invasive EEG recordings in temporal lobe epilepsy. Furthermore, in extratemporal epilepsies functional imaging techniques facilitate the placement of the electrodes for invasive EEG recording. (orig.)

  10. Positron emission tomography in patients suffering from HIV-1 infection

    Energy Technology Data Exchange (ETDEWEB)

    Sathekge, Mike [University Hospital of Pretoria, Department of Nuclear Medicine, Pretoria (South Africa); Goethals, Ingeborg; Wiele, Christophe van de [University Hospital Ghent, Department of Nuclear Medicine, Ghent (Belgium); Maes, Alex [AZ Groening, Department of Nuclear Medicine, Kortrijk (Belgium)

    2009-07-15

    This paper reviews currently available PET studies performed either to improve our understanding of the pathogenesis of HIV-1 infection or to assess the value of PET imaging in the clinical decision making of patients infected with HIV-1 presenting with AIDS-related opportunistic infections and malignancies. FDG PET has shown that HIV-1 infection progresses by distinct anatomical steps, with involvement of the upper torso preceding involvement of the lower part of the torso, and that the degree of FDG uptake relates to viral load. The former finding suggests that lymphoid tissues are engaged in a predictable sequence and that diffusible mediators of activation might be important targets for vaccine or therapeutic intervention strategies. In lipodystrophic HIV-infected patients, limited available data support the hypothesis that stavudine-related lipodystrophy is associated with increased glucose uptake by adipose tissue as a result of the metabolic stress of adipose tissue in response to highly active antiretroviral treatment (HAART). Finally, in early AIDS-related dementia complex (ADC), striatal hypermetabolism is observed, whereas progressive ADC is characterized by a decrease in subcortical and cortical metabolism. In the clinical setting, PET has been shown to allow the differentiation of AIDS-related opportunistic infections and malignancies, and to allow monitoring of side effects of HAART. However, in patients suffering from HIV infection and presenting with extracerebral lymphoma or other human malignancies, knowledge of viraemia is essential when interpreting FDG PET imaging. (orig.)

  11. Influence of slice overlap on positron emission tomography image quality

    Science.gov (United States)

    McKeown, Clare; Gillen, Gerry; Dempsey, Mary Frances; Findlay, Caroline

    2016-02-01

    PET scans use overlapping acquisition beds to correct for reduced sensitivity at bed edges. The optimum overlap size for the General Electric (GE) Discovery 690 has not been established. This study assesses how image quality is affected by slice overlap. Efficacy of 23% overlaps (recommended by GE) and 49% overlaps (maximum possible overlap) were specifically assessed. European Association of Nuclear Medicine (EANM) guidelines for calculating minimum injected activities based on overlap size were also reviewed. A uniform flood phantom was used to assess noise (coefficient of variation, (COV)) and voxel accuracy (activity concentrations, Bq ml-1). A NEMA (National Electrical Manufacturers Association) body phantom with hot/cold spheres in a background activity was used to assess contrast recovery coefficients (CRCs) and signal to noise ratios (SNR). Different overlap sizes and sphere-to-background ratios were assessed. COVs for 49% and 23% overlaps were 9% and 13% respectively. This increased noise was difficult to visualise on the 23% overlap images. Mean voxel activity concentrations were not affected by overlap size. No clinically significant differences in CRCs were observed. However, visibility and SNR of small, low contrast spheres (⩽13 mm diameter, 2:1 sphere to background ratio) may be affected by overlap size in low count studies if they are located in the overlap area. There was minimal detectable influence on image quality in terms of noise, mean activity concentrations or mean CRCs when comparing 23% overlap with 49% overlap. Detectability of small, low contrast lesions may be affected in low count studies—however, this is a worst-case scenario. The marginal benefits of increasing overlap from 23% to 49% are likely to be offset by increased patient scan times. A 23% overlap is therefore appropriate for clinical use. An amendment to EANM guidelines for calculating injected activities is also proposed which better reflects the effect overlap size has

  12. Geneva University - The AX-PET experiment : A demonstrator for an axial Positron Emission Tomography

    CERN Multimedia

    Université de Genève

    2012-01-01

    Geneva University École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92   Wednesday 14 March 2012 SEMINAIRE DE PHYSIQUE CORPUSCULAIRE 11.15 a.m. - Science II, Auditoire 1S081, 30, quai Ernest-Ansermet, 1211 Genève 4 The AX-PET experiment : A demonstrator for an axial Positron Emission Tomography Dr Chiara CASELLA   ETH Zurich   PET (Positron Emission Tomography) is a tool for in-vivo functional imaging, successfully used since the earliest days of nuclear medicine. It is based on the detection of the two coincident 511 keV photons from the annihilation of a positron, emitted from a radiotracer injected into the body. Tomographic analysis of the coincidence data allows for a 3D reconstructed image of the source distribution. The AX-PET experiment proposes a novel geometrical approach for a PET scanner, in which l...

  13. Assessment of pathophysiology of stroke by positron emission tomography

    International Nuclear Information System (INIS)

    In stroke patients, multitracer PET permits the assessment of acute changes in regional cerebral blood flow, blood volume, oxygen consumption and glucose metabolism. While early infarcts exhibit low flow and oxygen consumption, increased oxygen extraction fraction due to preserved metabolism at reduced flow suggests viability of tissue. However, most initially ''viable'' tissue will be metabolically deranged and will become necrotic in the further course. Increased glucose uptake at reduced oxygen supply induces non-oxidative glycolysis with noxious lactacidosis, whereas hyperperfusion beyond the metabolic demand is of controversial effect. In subacute or chronic states after ischaemia reduced flow can be compensated by increased blood volume; when perfusional reserve is exhausted, oxygen extraction increases. Such findings may guide therapeutic decisions and predict the severity of permanent deficits. Functional deactivation of tissue remote from the lesion is found regularly as a sign of damaged connecting pathways. Flow and metabolic studies during the performance of specific tasks help to detect alternative functional loops and may yield prognostic information. Repeat studies in the course of stroke are employed for the evaluation of therapeutic strategies targeted to improve reperfusion or to effect metabolic or biochemical alterations. In the future PET may gain additional clinical importance when patients are selected for elective treatment according to the prevailing pathophysiological pattern. (orig./MG)

  14. High power laser production of short-lived isotopes for positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a powerful diagnostic/imaging technique requiring the production of the short-lived positron emitting isotopes 11C, 13N, 15O and 18F by proton irradiation of natural/enriched targets using cyclotrons. The development of PET has been hampered due to the size and shielding requirements of nuclear installations. Recent results show that when an intense laser beam interacts with solid targets, megaelectronvolt (MeV) protons capable of producing PET isotopes are generated. This report describes how to generate intense PET sources of 11C and 18F using a petawatt laser beam. The work describing the laser production of 18F through a (p,n) 18O reaction, and the subsequent synthesis of 2-[18F] is reported for the first time. The potential for developing compact laser technology for this purpose is discussed

  15. Brain energy metabolism and dopaminergic function in Huntington's disease measured in vivo using positron emission tomography

    International Nuclear Information System (INIS)

    A 48-year-old man with typical Huntington's disease was investigated with computed tomography (CT) and positron emission tomography. Regional cerebral blood flow, oxygen extraction, oxygen and glucose utilization, L-Dopa uptake, and dopamine (D2) receptor binding were measured using several positron-labelled tracers. CT showed slight atrophy of the head of caudate but no cortical atrophy, although distinct frontal lobe dysfunction was present on psychometric testing. Oxygen and glucose metabolism and cerebral blood flow were decreased in the striata and to a lesser extent in frontal cortex. Cerebral blood flow was in the low normal range throughout the remainder of the brain. A normal metabolic ratio was found in all regions, since the changes in glucose utilization paralleled those in oxygen consumption. The capacity of the striatum to store dopamine as assessed by L-[18F]-fluorodopa uptake was normal, but dopamine (D2) receptor binding was decreased when compared to normal subjects

  16. Diagnostic value for extrahepatic metastases of hepatocellular carcinoma in positron emission tomography/computed tomography scan

    Institute of Scientific and Technical Information of China (English)

    Ji Eun Lee; Jae Young Jang; Soung Won Jeong; Sae Hwan Lee; Sang Gyune Kim; Sang-Woo Cha; Young Seok Kim

    2012-01-01

    AIM:To evaluated the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan in diagnosis of hepatocellular carcinoma (HCC) and extrahepatic metastases.METHODS:A total of 138 patients with HCC who had both conventional imaging modalities and 18F-FDG PET/CT scan done between November 2006 and March 2011 were enrolled.Diagnostic value of each imaging modality for detection of extrahepatic metastases was evaluated.Clinical factors and tumor characteristics including PET imaging were analyzed as indicative factors for metastases by univariate and multivariate methods.RESULTS:The accuracy of chest CT was significantly superior compared with the accuracy of PET imaging for detecting lung metastases.The detection rate of metastatic pulmonary nodule ≥ 1 cm was 12/13(92.3%),when < 1 cm was 2/10 (20%) in PET imaging.The accuracy of PET imaging was significantly superior compared with the accuracy of bone scan for detecting bone metastases.In multivariate analysis,increased tumor size (≥ 5 cm) (P =0.042) and increased average standardized uptake value (SUV)uptake (P =0.028) were predictive factors for extrahepatic metastases.Isometabolic HCC in PET imaging was inversely correlated in multivariate analysis (P =0.035).According to the receiver operating characteristic curve,the optimal cutoff of average SUV to predict extrahepatic metastases was 3.4.CONCLUSION:18F-FDG PET/CT scan is invaluable for detection of lung metastases larger than 1 cm and bone metastases.Primary HCC having larger than 5 cm and increased average SUV uptake more than 3.4should be considered for extrahepatic metastases.

  17. Occupational Exposure to Veterinary Workers from the Positron Emission Tomography Imaging Agent 64Cu-ATSM.

    Science.gov (United States)

    Hetrick, Lucas D; Kraft, Susan L; Johnson, Thomas E

    2015-11-01

    Cu-ATSM is an emerging radiopharmaceutical for diagnostic use in positron emission tomography (PET), but to date there are no studies that assess the potential occupational doses to workers in either human or veterinary medicine. This study was aimed at determining the external radiation dose to veterinary workers from clinical PET/CT (PET combined with computed tomography) procedures using Cu-ATSM. To determine the dose to the workers, each worker was assigned two Electronic Personal Dosimeters (EPDs) to be worn on the chest and waist during the entirety of each procedure. The workers monitored during this study included a radiobiologist, a nuclear medicine technologist, an anesthesiologist, and a veterinary surgeon. Seven canine patients were imaged with an average mass of 33.7 kg (a range of 20.0-55.1 kg) with an average injected activity of 5 MBq kg. The dose range for the radiobiologist was 2-17 μSv (mean of 7.1 μSv), for the nuclear medicine technologist 0-14 μSv (mean of 5.6 μSv), for the anesthesiologist 0-12 μSv (mean of 4.0 μSv), and for the surgeon 0-10 μSv (mean of 3.6 μSv). In a comparison between the results of this study and published literature on occupational exposures from veterinary FDG PET/CT procedures, Cu-ATSM veterinary PET/CT procedures, on a per patient bias, exposed workers to less radiation. PMID:26425985

  18. Differentiating cardiomyopathy of coronary artery disease from nonischemic dilated cardiomyopathy utilizing positron emission tomography

    International Nuclear Information System (INIS)

    To determine if imaging of blood flow (using N-13 ammonia) and glucose metabolism (using F-18 2-deoxyglucose) with positron emission tomography can distinguish cardiomyopathy of coronary artery disease from nonischemic dilated cardiomyopathy, 21 patients with severe left ventricular dysfunction who were evaluated for cardiac transplantation were studied. The origin of left ventricular dysfunction had been previously determined by coronary angiography to be ischemic (11 patients) or nonischemic (10 patients). Images were visually analyzed by three observers on a graded scale in seven left ventricular segments and revealed fewer defects in dilated cardiomyopathy compared with ischemic cardiomyopathy for N-13 ammonia (2.7 +/- 1.6 versus 5 +/- 0.6; p less than 0.03) and F-18 deoxyglucose (2.8 +/- 2.1 versus 4.6 +/- 1.1; p less than 0.03). An index incorporating extent and severity of defects revealed more homogeneity with fewer and less severe defects in subjects with nonischemic than in those with ischemic cardiomyopathy as assessed by imaging of flow (2.8 +/- 1.8 versus 9.2 +/- 3; p less than 0.001) and metabolism (3.8 +/- 3.3 versus 8.5 +/- 3.6; p less than 0.005). Diagnostic accuracy for distinguishing the two subgroups by visual image analysis was 85%. Using previously published circumferential count profile criteria, patients with dilated cardiomyopathy had fewer ischemic segments (0.4 +/- 0.8 versus 2.5 +/- 2 per patient; p less than 0.01) and infarcted segments (0.1 +/- 0.3 versus 2.4 +/- 1.4 per patient; p less than 0.001) than did patients with cardiomyopathy of coronary artery disease. The sensitivity for differentiating the two clinical subgroups using circumferential profile analysis was 100% and the specificity 80%

  19. Brain glucose utilization in systemic lupus erythematosus with neuropsychiatric symptoms: a controlled positron emission tomography study

    International Nuclear Information System (INIS)

    In contrast to morphological imaging [such as magnetic resonance imaging (MRI) or computed tomography], functional imaging may be of advantage in the detection of brain abnormalities in cases of neuropsychiatric systemic lupus erythematosus (SLE). Therefore, we studied 13 patients (aged 40±14 years, 11 female, 2 male) with neuropsychiatric SLE who met four of the American Rheumatism Association criteria for the classification of SLE. Ten clinically and neurologically healthy volunteers served as controls (aged 40±12 years, 5 female, 5 male). Both groups were investigated using fluorine-18-labelled fluorodeoxyglucose brain positron emission tomography (PET) and cranial MRI. The normal controls and 11 of the 13 patients showed normal MRI scans. However, PET scan was abnormal in all 13 SLE patients. Significant group-to-group differences in the glucose metabolic index (GMI=region of interest uptake/global uptake at the level of the basal ganglia and thalamus) were found in the parieto-occipital region on both sides: the GMI of the parieto-occipital region on the right side was 0.922±0.045 in patients and 1.066±0.081 in controls (P<0.0001, Mann Whitney U test), while on the left side it was 0.892±0.060 in patients and 1.034±0.051 in controls (P=0.0002). Parieto-occipital hypometabolism is a conspicuous finding in mainly MRI-negative neuropsychiatric SLE. As the parieto-occipital region is located at the boundary of blood supply of all three major arteries, it could be the most vulnerable zone of the cerebrum and may be affected at an early stage of the cerebrovascular disease. (orig.). With 1 fig., 1 tab

  20. Fluorine-18 fluorodeoxyglucose positron emission tomography in the follow-up of differentiated thyroid cancer

    International Nuclear Information System (INIS)

    Whole-body fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging was performed during the follow-up of 33 patients suffering from differentiated thyroid cancer. Among them there were 26 patients with papillary and seven with follicular tumours. Primary tumour stage (pT) was pT1 in six cases, pT2 in eight cases, pT3 in three cases and pT4 in 14 cases. FDG PET was normal in 18 patients. In three patients a slightly increased metabolism was observed in the thyroid bed, assumed to be related to remnant tissue. In one case local recurrence, in ten cases lymph node metastases (one false-positive, caused by sarcoidosis) and in three cases distant metastases were found with FDG PET. In comparison with whole-body scintigraphy using iodine-131 (WBS) there were a lot of discrepancies in imaging results. Whereas three patients had distant metastases (proven with 131I) and a negative FDG PET, in four cases 131I-negative lymph node metastases were detectable with PET. Even in the patients with concordant ''staging'', differences between 131I and FDG were observed as to the exact lesion localization. Therefore, a coexistence of 131I-positive/FDG-negative, 131I-negative/FDG-positive and 131I-positive/FDG-positive malignant tissue can be assumed in these patients. A higher correlation of FDG PET was observed with hexakis (2-methoxyisobutylisonitrile) technetium-99m (I) (MIBI) scintigraphy (performed in 20 cases) than with WBS. In highly differentiated tumours 131I scintigraphy had a high sensitivity, whereas in poorly differentiated carcinomas FDG PET was superior. The clinical use of FDG PET can be recommended in all cases of suspected or proven recurrence and/or metastases of differentiated thyroid cancer and is particularly useful in cases with elevated serum thyroglobulin levels and negative WBS. (orig.). With 3 figs., 2 tabs

  1. Digital contrast enhancement of 18Fluorine-fluorodeoxyglucose positron emission tomography images in hepatocellular carcinoma

    Science.gov (United States)

    Pandey, Anil Kumar; Sharma, Sanjay Kumar; Agarwal, Krishan Kant; Sharma, Punit; Bal, Chandrasekhar; Kumar, Rakesh

    2016-01-01

    Purpose: The role of 18fluorodeoxyglucose positron emission tomography (PET) is limited for detection of primary hepatocellular carcinoma (HCC) due to low contrast to the tumor, and normal hepatocytes (background). The aim of the present study was to improve the contrast between the tumor and background by standardizing the input parameters of a digital contrast enhancement technique. Materials and Methods: A transverse slice of PET image was adjusted for the best possible contrast, and saved in JPEG 2000 format. We processed this image with a contrast enhancement technique using 847 possible combinations of input parameters (threshold “m” and slope “e”). The input parameters which resulted in an image having a high value of 2nd order entropy, and edge content, and low value of absolute mean brightness error, and saturation evaluation metrics, were considered as standardized input parameters. The same process was repeated for total nine PET-computed tomography studies, thus analyzing 7623 images. Results: The selected digital contrast enhancement technique increased the contrast between the HCC tumor and background. In seven out of nine images, the standardized input parameters “m” had values between 150 and 160, and for other two images values were 138 and 175, respectively. The value of slope “e” was 4 in 4 images, 3 in 3 images and 1 in 2 images. It was found that it is important to optimize the input parameters for the best possible contrast for each image; a particular value was not sufficient for all the HCC images. Conclusion: The use of above digital contrast enhancement technique improves the tumor to background ratio in PET images of HCC and appears to be useful. Further clinical validation of this finding is warranted. PMID:26917889

  2. Positron emission tomography 2008 in Germany. Results of the query and current status

    International Nuclear Information System (INIS)

    Aim: The working group on positron emission tomography (PET) of the DGN (German Society of Nuclear Medicine) initiated this first survey to collect and analyse information on the practise of PET in Germany in the year 2008. Methods: A questionnaire was sent to PET performing facilities (medical practices, hospitals, university hospitals and others) for retrospective data acquisition. Details regarding the equipment and examination procedures were examined as well as indications and number of studies. In addition, the role of PET within the diagnostic process was evaluated. Results: Responses from 65 sites were analysed. Their technical equipment consisted of 77 PET scanners (40 of them were combined PET/CT devices). About 63 500 PET studies had been performed with 86% in the field of oncology, 8% in neurology and 3% in cardiology. The radiotracers were labelled with 18F in 91% of the studies, whereas 68Ga was used in 4% and 11C in 3%. The analyses revealed lung tumours as the most investigated tumour entity, followed by malignant lymphoma, tumours of the gastro-intestinal tract and prostate cancer (about 14 000, 6000, 5000 and 2000). Corresponding to the new scanners and software procedures, the number of studies with attenuation correction by CT was high (68%) and nearly all studies were reconstructed iteratively (99%). The PET images were analysed quantitatively in the majority of cases (91%). The clinical reports, which included image documentation for the greater part, were posted regularly within 3 days. However, in 70% of the sites electronic transfer possibilities were used additionally to speed up the diagnostic process. The high standard of quality was demonstrated by the fact, that 40 facilities were engaged in a tumour board. Further on, one third of the physicians had gained a PET certification awarded by the DGN. Conclusion: Relative to the high general standard of diagnostic instrumentation in Germany, PET is less established, in particular when

  3. Utility of positron emission tomography for tumour surveillance in children with neurofibromatosis type 1

    Energy Technology Data Exchange (ETDEWEB)

    Moharir, Mahendranath [Hospital for Sick Children, Division of Neurology, Ontario (Canada); London, Kevin [Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney (Australia); Howman-Giles, Robert [University of Sydney, Discipline of Imaging, Faculty of Medicine, Sydney (Australia); North, Kathryn [Children' s Hospital at Westmead, Institute for Neuroscience and Muscle Research, Sydney, NSW (Australia)

    2010-07-15

    There is little consensus regarding optimal surveillance of optic pathway glioma (OPG) and plexiform neurofibroma (PNF) in childhood neurofibromatosis type 1 (NF1). {sup 18}F-2-Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography and computed tomography (PET/CT) is employed in the surveillance of adult PNFs; but its utility has neither been specifically studied in children with PNFs nor in children with OPG. Review of PET/CT studies was performed in NF1 children with OPG or PNF. FDG-avidity of tumours was semi-quantitatively analysed and graded by calculating the maximum standardised uptake value (SUV{sub max}) [grade 1: <3 (low), grade 2: >3-<4 (intermediate), grade 3: >4 (intense)]. Eighteen children (ten girls; median age: 8.5-years) had PET/CT. Nineteen OPGs were imaged. The SUV{sub max} could be measured in 16. Ten were grade 1 and three each were grade 2 and grade 3. FDG-avidity reduced from grade 3 to grade 1 in two symptomatic OPGs following chemotherapy and this was associated with clinical improvement. PET/CT diagnosed symptomatic OPGs with a sensitivity of 0.625 [95% confidence interval (CI): 0.259-0.897] and specificity of 0.875 (95% CI: 0.466-0.993). Sixteen PNFs were imaged. Twelve were grade 1 and two each were grade 2 and grade 3. The two grade 3 PNFs were confirmed malignant peripheral nerve sheath tumours. PET/CT diagnosed malignant transformation with a sensitivity of 1.0 (95% CI: 0.197-1.0) and specificity of 0.857 (95% CI: 0.561-0.974). PET/CT may contribute useful information to the surveillance of OPG in childhood NF1 - particularly to identify progressive, symptomatic tumours. As in adults, PET/CT is useful for the detection of malignant transformation in PNFs in children with NF1. (orig.)

  4. Pitfalls in Positron Emission Tomography/Computed Tomography Imaging: Causes and Their Classifications

    Institute of Scientific and Technical Information of China (English)

    Tian-ran Li; Jia-he Tian; Hui Wang; Zi-qian Chen; Chun-lei Zhao

    2009-01-01

    Objective To describe the pitfalls in positron emission tomography/computed tomography (PET/CT) imaging and classify them according to the principles of their generation. Methods We summarized retrospectively the 18F-fluorodeoxyglucose (FDP) PET/CT imaging pitfalls through reviewing the PET/CT images of 872 patients. The pitfalls were divided into artifacts and infrequent physiological uptake, and the artifacts were further classified according to their causes. Meanwhile, we calculated the incidences of various pitfalls. Whether the PET/CT pitfalls influenced the diagnostic decision was analyzed. The appearances of pitfalls in PET were also described. Results Pitfalls could be found in PET/CT images of 684 (78.4%) patients. Artifacts were found in 664 (76.15%) patients, and could be classified into self-factor artifacts and equipment- or technology- related artifacts. Among self-factor artifacts, respiratory motion (57.5%), postprandial or hyperglycemia artifacts (2.41%), and metal or high density matter artifacts (1.38%) were frequent. As for equipment- or technology-related factors, injection point outleakage or radiotracer contamination (13.88%) and truncation artifacts (1.83%) were most common ones. Infrequent physiological FDG uptakes, including fatty uptake, endometrial uptake, and bilateral breast feeding period uptake, were found in 20 (2.29%) patients. Among all pitfalls, the artifacts in 92 (13.4%) patients and infrequent physiological uptakes in 6 (0.88%) patients affected the diagnostic results. Artifact images in PET could be described as hot or cold area and the images of infrequent physiological uptake were always shown as hot area. Conclusions The incidence of pitfall in PET/CT imaging was high and the causes of pitfalls are various. Among all causes that artifacts generated, respiratory motion is the most common. Some pitfalls may disturb clinical physicians' decision, so it is important to recognize artifacts and physiological uptake, and

  5. Utility of positron emission tomography for tumour surveillance in children with neurofibromatosis type 1

    International Nuclear Information System (INIS)

    There is little consensus regarding optimal surveillance of optic pathway glioma (OPG) and plexiform neurofibroma (PNF) in childhood neurofibromatosis type 1 (NF1). 18F-2-Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography and computed tomography (PET/CT) is employed in the surveillance of adult PNFs; but its utility has neither been specifically studied in children with PNFs nor in children with OPG. Review of PET/CT studies was performed in NF1 children with OPG or PNF. FDG-avidity of tumours was semi-quantitatively analysed and graded by calculating the maximum standardised uptake value (SUVmax) [grade 1: 3-4 (intense)]. Eighteen children (ten girls; median age: 8.5-years) had PET/CT. Nineteen OPGs were imaged. The SUVmax could be measured in 16. Ten were grade 1 and three each were grade 2 and grade 3. FDG-avidity reduced from grade 3 to grade 1 in two symptomatic OPGs following chemotherapy and this was associated with clinical improvement. PET/CT diagnosed symptomatic OPGs with a sensitivity of 0.625 [95% confidence interval (CI): 0.259-0.897] and specificity of 0.875 (95% CI: 0.466-0.993). Sixteen PNFs were imaged. Twelve were grade 1 and two each were grade 2 and grade 3. The two grade 3 PNFs were confirmed malignant peripheral nerve sheath tumours. PET/CT diagnosed malignant transformation with a sensitivity of 1.0 (95% CI: 0.197-1.0) and specificity of 0.857 (95% CI: 0.561-0.974). PET/CT may contribute useful information to the surveillance of OPG in childhood NF1 - particularly to identify progressive, symptomatic tumours. As in adults, PET/CT is useful for the detection of malignant transformation in PNFs in children with NF1. (orig.)

  6. Optimal scan time for evaluating pancreatic disease with positron emission tomography using F-18-fluorodeoxyglucose

    International Nuclear Information System (INIS)

    Image interpretation in positron emission tomography (PET) using F-18-fluoro-2-deoxy-D-glucose (FDG) is usually performed for images obtained at 1 h postinjection (PI) of FDG, but it remains unknown whether this is the optimal time for imaging patients with pancreatic disease. The aim of this study was to assess the optimal scan time for FDG-PET for patients suspected of having pancreatic cancer. Forty-four patients with suspected pancreatic cancer underwent FDG-PET scans at both 1 h and 2 h PI. Tracer uptake in the pancreatic lesions and possible liver metastasis was interpreted qualitatively, using a 5-point grading system (0=normal, 1=probably normal, 2=equivocal, 3=probably abnormal, and 4=definitely abnormal) by 4 nuclear medicine physicians independently, who were blind to all clinical information. Detection performance with each image was compared using receiver operating characteristic (ROC) analysis. An average score of the 4 readers for each patient was also defined as consensus average index (CAI) and compared between the two images. ROC results indicated no significant differences in detection performance (Averaged areas under ROC curves of 1 h vs. 2 h were 0.92 vs. 0.90 for primary tumor, and 0.81 vs. 0.85 for liver metastases). There were no significant differences in CAIs between 1 h and 2 h PI images in interpreting primary tumor and positive liver metastases, but a significant difference was observed for cases without liver metastases (p<0.05). The certainty of excluding liver metastases was increased when the 2 h image was used, although ROC analysis did not establish a difference between 1 h and 2 h imaging for differentiating malignant and benign lesions in primary pancreatic cancer or its liver metastases. (author)

  7. Lesion quantification in oncological positron emission tomography: a maximum likelihood partial volume correction strategy.

    Science.gov (United States)

    De Bernardi, Elisabetta; Faggiano, Elena; Zito, Felicia; Gerundini, Paolo; Baselli, Giuseppe

    2009-07-01

    A maximum likelihood (ML) partial volume effect correction (PVEC) strategy for the quantification of uptake and volume of oncological lesions in 18F-FDG positron emission tomography is proposed. The algorithm is based on the application of ML reconstruction on volumetric regional basis functions initially defined on a smooth standard clinical image and iteratively updated in terms of their activity and volume. The volume of interest (VOI) containing a previously detected region is segmented by a k-means algorithm in three regions: A central region surrounded by a partial volume region and a spill-out region. All volume outside the VOI (background with all other structures) is handled as a unique basis function and therefore "frozen" in the reconstruction process except for a gain coefficient. The coefficients of the regional basis functions are iteratively estimated with an attenuation-weighted ordered subset expectation maximization (AWOSEM) algorithm in which a 3D, anisotropic, space variant model of point spread function (PSF) is included for resolution recovery. The reconstruction-segmentation process is iterated until convergence; at each iteration, segmentation is performed on the reconstructed image blurred by the system PSF in order to update the partial volume and spill-out regions. The developed PVEC strategy was tested on sphere phantom studies with activity contrasts of 7.5 and 4 and compared to a conventional recovery coefficient method. Improved volume and activity estimates were obtained with low computational costs, thanks to blur recovery and to a better local approximation to ML convergence. PMID:19673203

  8. Fluorodeoxyglucose positron emission tomography in the initial staging of germ cell tumours

    Energy Technology Data Exchange (ETDEWEB)

    Hain, S.F.; O' Doherty, M.J. [Clinical PET Centre, Guy' s and St Thomas' Hospitals, London (United Kingdom); Timothy, A.R.; Leslie, M.D.; Partridge, S.E. [Dept. of Clinical Oncology, Guy' s and St Thomas' Hospitals, London (United Kingdom); Huddart, R.A. [Dept. of Radiotherapy and Oncology, Royal Marsden, Surrey (United Kingdom)

    2000-05-01

    Testicular cancer is a rare tumour with the potential for cure at diagnosis. It is important, however, to identify those patients with metastases at presentation so as to ensure that the optimum treatment strategy is employed. Many criteria have been used to try to place patients into high- or low-risk groups, with variable success. Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has the potential to identify active disease and thereby influence further management. Here we report on a retrospective study of the use of FDG-PET in the detection of metastatic testicular carcinoma at diagnosis. Thirty-one patients [13 with seminoma and 18 with non-seminomatous germ cell tumours (13 teratomas, 5 mixed)] were staged by FDG-PET scanning. The imaging was performed using a Siemens ECAT 951 scanner. All results were assessed on the basis of histology or clinical follow-up. FDG-PET scan identified metastatic disease in ten and was negative in 16; there were no false-positives and five false-negatives. There were six patients in whom FDG-PET was negative and computed tomography was regarded as suspicious but follow-up was inconclusive. The positive predictive value was 100%. The negative predictive value was 76% or 91%, depending on whether the aforementioned six cases were regarded as true-negatives or false-negatives. It may be concluded that FDG-PET is capable of detecting metastatic disease at diagnosis that is not identified by other imaging techniques. These preliminary results are sufficient to suggest that a large prospective study should be performed to evaluate the role of FDG-PET in primary staging of disease. (orig.)

  9. The relationship between cerebrospinal fluid markers of Alzheimer pathology and positron emission tomography tau imaging.

    Science.gov (United States)

    Gordon, Brian A; Friedrichsen, Karl; Brier, Matthew; Blazey, Tyler; Su, Yi; Christensen, Jon; Aldea, Patricia; McConathy, Jonathan; Holtzman, David M; Cairns, Nigel J; Morris, John C; Fagan, Anne M; Ances, Beau M; Benzinger, Tammie L S

    2016-08-01

    The two primary molecular pathologies in Alzheimer's disease are amyloid-β plaques and tau-immunoreactive neurofibrillary tangles. Investigations into these pathologies have been restricted to cerebrospinal fluid assays, and positron emission tomography tracers that can image amyloid-β plaques. Tau tracers have recently been introduced into the field, although the utility of the tracer and its relationship to other Alzheimer biomarkers are still unknown. Here we examined tau deposition in 41 cognitively normal and 11 cognitively impaired older adults using the radioactive tau ligand (18)F-AV-1451 (previously known as T807) who also underwent a lumbar puncture to assess cerebrospinal fluid levels of total tau (t-tau), phosphorylated tau181 (p-tau181) and amyloid-β42 Voxel-wise statistical analyses examined spatial patterns of tau deposition associated with cognitive impairment. We then related the amount of tau tracer uptake to levels of cerebrospinal fluid biomarkers. All analyses controlled for age and gender and, when appropriate, the time between imaging and lumbar puncture assessments. Symptomatic individuals (Clinical Dementia Rating > 0) demonstrated markedly increased levels of tau tracer uptake. This elevation was most prominent in the temporal lobe and temporoparietal junction, but extended more broadly into parietal and frontal cortices. In the entire cohort, there were significant relationships among all cerebrospinal fluid biomarkers and tracer uptake, notably for tau-related cerebrospinal fluid markers. After controlling for levels of amyloid-β42, the correlations with tau uptake were r = 0.490 (P Alzheimer's disease, there is focal tauopathy in the medial temporal lobes and adjacent cortices. PMID:27286736

  10. Pharmacokinetics of Genetically Engineered Antibody Forms Using Positron Emission Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Steven M. Larson, M.D. Nai-Kong Cheung, M.D., Ph.D.

    2004-08-31

    In the last grant period we have focused on multi-step targeting methodologies (MST), as a method for delivery of high dose to the tumor, with low dose to the bone marrow. We have explored uptake in colorectal, pancreatic and prostate cancer, using an special preparation, developed in collaboration with NeoRex A high tumor/bone marrow ratio is clearly achieved with MST, but with a cost, namely the higher dose to normal kidney. For this reason, we have in particular, (a) looked dosimetry for both tumor and normal organ, and especially renal dosimetry, which appears to be the target organ, for Y-90. (b) In parallel with this we have explored the dosimetry of very high dose rate radionuclides, including Holmium-166. (c) In addition, with NaiKong Cheung, we have developed a new MST construct based on the anti-GD2 targeting 5F11; (d) we have successfully completed development of s-factor tables for mice. In summary, renal dosimetry is dominated by about 4-5% of the injected dose being held long-term in the renal cortex, probably in the proximal tubule, due to the universal uptake of small proteins. This appears to be a function of a biotynlated protein binding of the strept-avidin construct, to HSP70. This cortical uptake has caused us to reconsider renal dosimetry as a whole, with the smaller mass of the cortex, rather than the whole kidney, as the target organ. These insights into dosimetry will be of great importance as MST, becomes more common in clinical practice.

  11. Clinical CT-based calculations of dose and positron emitter distributions in proton therapy using the FLUKA Monte Carlo code

    Science.gov (United States)

    Parodi, K.; Ferrari, A.; Sommerer, F.; Paganetti, H.

    2007-07-01

    Clinical investigations on post-irradiation PET/CT (positron emission tomography/computed tomography) imaging for in vivo verification of treatment delivery and, in particular, beam range in proton therapy are underway at Massachusetts General Hospital (MGH). Within this project, we have developed a Monte Carlo framework for CT-based calculation of dose and irradiation-induced positron emitter distributions. Initial proton beam information is provided by a separate Geant4 Monte Carlo simulation modelling the treatment head. Particle transport in the patient is performed in the CT voxel geometry using the FLUKA Monte Carlo code. The implementation uses a discrete number of different tissue types with composition and mean density deduced from the CT scan. Scaling factors are introduced to account for the continuous Hounsfield unit dependence of the mass density and of the relative stopping power ratio to water used by the treatment planning system (XiO (Computerized Medical Systems Inc.)). Resulting Monte Carlo dose distributions are generally found in good correspondence with calculations of the treatment planning program, except a few cases (e.g. in the presence of air/tissue interfaces). Whereas dose is computed using standard FLUKA utilities, positron emitter distributions are calculated by internally combining proton fluence with experimental and evaluated cross-sections yielding 11C, 15O, 14O, 13N, 38K and 30P. Simulated positron emitter distributions yield PET images in good agreement with measurements. In this paper, we describe in detail the specific implementation of the FLUKA calculation framework, which may be easily adapted to handle arbitrary phase spaces of proton beams delivered by other facilities or include more reaction channels based on additional cross-section data. Further, we demonstrate the effects of different acquisition time regimes (e.g., PET imaging during or after irradiation) on the intensity and spatial distribution of the irradiation

  12. The 511 keV emission from positron annihilation in the Galaxy

    CERN Document Server

    Prantzos, N; Bykov, A M; Diehl, R; Ferriere, K; Guessoum, N; Jean, P; Knoedlseder, J; Marcowith, A; Moskalenko, I V; Strong, A; Weidenspointner, G

    2010-01-01

    The first gamma-ray line originating from outside the solar system that was ever detected is the 511 keV emission from positron annihilation in the Galaxy. Despite 30 years of intense theoretical and observational investigation, the main sources of positrons have not been identified up to now. Observations in the 1990's with OSSE/CGRO showed that the emission is strongly concentrated towards the Galactic bulge. In the 2000's, the SPI instrument aboard ESA's INTEGRAL gamma-ray observatory allowed scientists to measure that emission across the entire Galaxy, revealing that the bulge/disk luminosity ratio is larger than observed in any other wavelength. This mapping prompted a number of novel explanations, including rather "exotic ones (e.g. dark matter annihilation). However, conventional astrophysical sources, like type Ia supernovae, microquasars or X-ray binaries, are still plausible candidates for a large fraction of the observed total 511 keV emission of the bulge. A closer study of the subject reveals new...

  13. Role of Positron Emission Tomography in the Treatment of Occult Disease in Head-and-Neck Cancer: A Modeling Approach

    International Nuclear Information System (INIS)

    Purpose: To determine under what conditions positron emission tomography (PET) imaging will be useful in decisions regarding the use of radiotherapy for the treatment of clinically occult lymph node metastases in head-and-neck cancer. Methods and Materials: A decision model of PET imaging and its downstream effects on radiotherapy outcomes was constructed using an influence diagram. This model included the sensitivity and specificity of PET, as well as the type and stage of the primary tumor. These parameters were varied to determine the optimal strategy for imaging and therapy for different clinical situations. Maximum expected utility was the metric by which different actions were ranked. Results: For primary tumors with a low probability of lymph node metastases, the sensitivity of PET should be maximized, and 50 Gy should be delivered if PET is positive and 0 Gy if negative. As the probability for lymph node metastases increases, PET imaging becomes unnecessary in some situations, and the optimal dose to the lymph nodes increases. The model needed to include the causes of certain health states to predict current clinical practice. Conclusion: The model demonstrated the ability to reproduce expected outcomes for a range of tumors and provided recommendations for different clinical situations. The differences between the optimal policies and current clinical practice are likely due to a disparity between stated clinical decision processes and actual decision making by clinicians.

  14. Standard of Practice Specific to Positron Emission Tomography (PET) Radiopharmaceuticals in Saudi Arabia

    International Nuclear Information System (INIS)

    Radiopharmaceuticals are essential tools for understanding human physiology and biochemistry, and subsequently, for the diagnosis and therapy of an extensive variety of diseases. Of the various cyclotron produced radiopharmaceuticals, positron emission tomography (PET) radiopharmaceuticals are being increasingly utilized in nuclear medicine imaging for both research and routine clinical diagnosis. The non-invasive PET imaging modality is unique in its ability to measure functional and metabolic activities of the body organs or tissues. These images are not available with other imaging technologies, such as CT, MRI or X-ray. With the aim of providing quality clinical service for the patients, acquiring most up-to-date imaging modality, PET has advanced exceptionally in the developed countries and with limited prevalence in developing countries. This must be attributed to the cost and complexity of such practice, in addition to the requirement of cyclotron and a radiochemistry laboratory on site for radiopharmaceuticals production. Our vision is to make the Kingdom of Saudi Arabia self-sufficient in all its requirements of radiopharmaceutical products as well as supplying the neighboring countries with such products for a comprehensive diagnostic and therapeutic care of the population. The Cyclotron and Radiopharmaceuticals Department (C and R) at the King Faisal Specialist Hospital and Research Center is a unique combination of advanced accelerator technology, radiochemistry, radiopharmacy, and radiopharmaceuticals research. A diverse staff composed of engineers, chemists, pharmacists and scientists work jointly with an aim to develop and manufacture SPECT and PET radioisotopes and their radiopharmaceutical products for on-demand availability in the clinical care of patients. The C and R Department ensures that it manufactures PET radiopharmaceutical products according to the international guidelines of Good Manufacturing Practices (GMP) and Good Radiopharmacy

  15. Adequacy of compartmental model for positron emission tomography examinations; Adequacao de modelo compartimental para exames de tomografia por emissao de positrons

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Joao Eduardo Maeda Moreira da; Furuie, Sergio Shiguemi [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia de Telecomunicacoes e Controle. Lab. de Engenharia Biomedica

    2011-12-15

    The objective of this work is the determination of the most adequate compartmental model for the study of physiological dynamics based on positron emission tomography exams. We propose the use of Akaike's information criterion for the optimal model selection, and Levenberg-Marquardt algorithm with sensitivity equations for the task of estimating the characteristic parameters of the differential equations describing the models. We have considered three compartmental structures represented, respectively, by two compartments and two characteristic constants, three compartments and four characteristic constants and four compartments and six characteristics constants. The data considered in this work were synthesized taking into account key features of a real tomography exam, such as type and level of noise and morphology of the input function of the system. Applying the proposed methodology with three noise levels (low, medium and high), we obtained agreement of the best model with strong and considerable degrees (with Kappa indexes equal to 0.95, 0.93 and 0.63, respectively). It was observed that, with high noise level and more complex models (four compartments), the classification is deteriorated due to lack of data for the decision. Programs have been developed and a graphical interface that can be used in research, development, simulation and parameter identification of compartmental models, supporting analysis of clinical diagnostics and scientific practices. (author)

  16. Bitemporal hypometabolism in Creutzfeldt-Jakob disease measured by positron emission tomography with [18F]-2-fluorodeoxyglucose

    International Nuclear Information System (INIS)

    It is well established that Creutzfeldt-Jakob disease (CJD) is caused by a slow infectious agent similar to the scrapie prion. However, the pathogenesis of this infection is poorly understood. Positron emission tomography (PET) was performed on a 54-year-old man with autopsy confirmed CJD using [18F]-2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. Temporal lobe hypometabolism with hemispheric asymmetry was observed. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer disease (AD). The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the possibility that AD may be caused by a slow infectious prion

  17. Dedifferentiated laryngeal chondrosarcoma: combined morphologic and functional imaging with positron-emission tomography/magnetic resonance imaging.

    Science.gov (United States)

    Purohit, Bela S; Dulguerov, Pavel; Burkhardt, Karim; Becker, Minerva

    2014-07-01

    Chondrosarcoma of the larynx is a rare, low-grade malignancy in terms of histology and clinical behavior. We present an unusual case of laryngeal chondrosarcoma, which developed a large dedifferentiated component on recurrence after primary surgery. The diagnosis of dedifferentiation was suggested in view of the morphological and metabolic findings on hybrid positron-emission tomography/magnetic resonance imaging (PET/MRI) and was subsequently confirmed surgically. Whole-organ, slice-by-slice radiologic-histologic correlation revealed excellent delineation of the well-differentiated and dedifferentiated tumor components with PET/MRI. PET/MRI can provide additional functional information to supplement the morphological mapping and histopathology of these tumors. PMID:24222068

  18. Imaging Spectrum and Pitfalls of 11C-Methionine Positron Emission Tomography in a Series of Patients with Intracranial Lesions

    Science.gov (United States)

    Matsuda, Hiroshi; Kubota, Kazoo

    2016-01-01

    11C-methionine (Met) positron emission tomography (PET) is one of the most commonly used PET tracers for evaluating brain tumors. However, few reports have described tips and pitfalls of 11C-Met PET for general practitioners. Physiological 11C-Met uptake, anatomical variations, vascular disorders, non-tumorous lesions such as inflammation or dysplasia, benign brain tumors and patient condition during 11C-Met PET examination can potentially affect the image interpretation and cause false positives and negatives. These pitfalls in the interpretation of 11C-Met PET images are important for not only nuclear medicine physicians but also general radiologists. Familiarity with the spectrum and pitfalls of 11C-Met images could help prevent unfavorable clinical results caused by misdiagnoses. PMID:27134530

  19. A comparison of endoscopic ultrasound guided biopsy and positron emission tomography with integrated computed tomography in lung cancer staging

    DEFF Research Database (Denmark)

    Larsen, S S; Vilmann, P; Krasnik, K;

    2009-01-01

    BACKGROUND AND STUDY AIMS: Exact staging of patients with non-small-cell lung cancer (NSCLC) is important to improve selection of resectable and curable patients for surgery. Positron emission tomography with integrated computed tomography (PET/CT) and endoscopic ultrasound guided fine needle...... aspiration biopsy (EUS-FNA) are new and promising methods, but indications in lung cancer staging are controversial. Only few studies have compared the 2 methods. The aim of this study was to assess and compare the diagnostic values of PET/CT and EUS-FNA for diagnosing advanced lung cancer in patients, who...... had both procedures performed. PATIENTS AND METHODS: 27 patients considered to be potential candidates for resection of NSCLC underwent PET/CT and EUS-FNA. Diagnoses were confirmed either by open thoracotomy, mediastinoscopy or clinical follow-up. Advanced lung cancer was defined as tumour...

  20. [18F]Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/Computed Tomography (CT) in Suspected Recurrent Breast Cancer

    DEFF Research Database (Denmark)

    Hildebrandt, Malene Grubbe; Gerke, Oke; Baun, Christina;

    2016-01-01

    PURPOSE: To prospectively investigate the diagnostic accuracy of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) with dual-time-point imaging, contrast-enhanced CT (ceCT), and bone scintigraphy (BS) in patients with suspected breast cancer recurrence....... PATIENTS AND METHODS: One hundred women with suspected recurrence of breast cancer underwent 1-hour and 3-hour FDG-PET/CT, ceCT, and BS within approximately 10 days. The study was powered to estimate the precision of the individual imaging tests. Images were visually interpreted using a four......-point assessment scale, and readers were blinded to other test results. The reference standard was biopsy along with treatment decisions and clinical follow-up (median, 17 months). RESULTS: FDG-PET/CT resulted in no false negatives and fewer false positives than the other imaging techniques. Accuracy of results...

  1. Novel Radioligands for Cyclic Nucleotide Phosphodiesterase Imaging with Positron Emission Tomography: An Update on Developments Since 2012

    Directory of Open Access Journals (Sweden)

    Susann Schröder

    2016-05-01

    Full Text Available Cyclic nucleotide phosphodiesterases (PDEs are a class of intracellular enzymes that inactivate the secondary messenger molecules, cyclic adenosine monophosphate (cAMP and cyclic guanosine monophosphate (cGMP. Thus, PDEs regulate the signaling cascades mediated by these cyclic nucleotides and affect fundamental intracellular processes. Pharmacological inhibition of PDE activity is a promising strategy for treatment of several diseases. However, the role of the different PDEs in related pathologies is not completely clarified yet. PDE-specific radioligands enable non-invasive visualization and quantification of these enzymes by positron emission tomography (PET in vivo and provide an important translational tool for elucidation of the relationship between altered expression of PDEs and pathophysiological effects as well as (pre-clinical evaluation of novel PDE inhibitors developed as therapeutics. Herein we present an overview of novel PDE radioligands for PET published since 2012.

  2. Licensing of facilities of tomography position emission. Acquired experience; Autorizacion de instalaciones de tomografia por emision de positrones. Experiencia adquirida

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, C.; Ramirez, M. L. [Consejo de Seguridad Nuclear. Madrid (Spain)

    2003-07-01

    Facilities with cyclotron used to produce positron emission radioisotopes and 18-FDG synthesis are considered of high risk because they use important quantities of non sealed radioactive material, which together with the high energy of acceleration beams make them difficult facilities. Also, the PET facilities that use 18-FDG, have specific radiological risk. The CSN analyses and evaluates during licensing each stage of the process, including 18-FDG synthesis, its clinic use and the conditioning of package for further transportation to other facilities. These facilities are subject to various technical requirements that must be present in the Resolution which authorize the set up. The CSN supervises the functioning of all these facilities. (Author) 9 refs.

  3. Realizing the potential of positron emission tomography with 18F-fluorodeoxyglucose to improve the treatment of Alzheimer's disease.

    Science.gov (United States)

    Foster, Norman L; Wang, Angela Y; Tasdizen, Tolga; Fletcher, P Thomas; Hoffman, John M; Koeppe, Robert A

    2008-01-01

    Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG-PET) thus far rarely has been used to advance the development of new treatments for Alzheimer's disease (AD). Now that FDG-PET with standard acquisition protocols for dementia is widely available, change in cerebral glucose metabolism is a feasible outcome variable for clinical drug trials. Individual analysis of FDG-PET results also might prove valuable. FDG-PET can detect metabolic changes very early in the course of AD and identify subjects for earlier treatment. FDG-PET reliably distinguishes AD from frontotemporal dementia so that only those most likely to benefit are enrolled in trials. Finally, objectively identifying phenotypic variations of AD with FDG-PET might have pathogenic and prognostic implications that can be used for personalized treatment approaches. The judicious use of FDG-PET is needed to accelerate the evaluation of promising new drugs and more rationally target treatments for dementing diseases. PMID:18631997

  4. Are We Ready for Positron Emission Tomography/Computed Tomography-based Target Volume Definition in Lymphoma Radiation Therapy?

    International Nuclear Information System (INIS)

    Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) has become indispensable for the clinical management of lymphomas. With consistent evidence that it is more accurate than anatomic imaging in the staging and response assessment of many lymphoma subtypes, its utility continues to increase. There have therefore been efforts to incorporate PET/CT data into radiation therapy decision making and in the planning process. Further, there have also been studies investigating target volume definition for radiation therapy using PET/CT data. This article will critically review the literature and ongoing studies on the above topics, examining the value and methods of adding PET/CT data to the radiation therapy treatment algorithm. We will also discuss the various challenges and the areas where more evidence is required.

  5. Preclinical studies on [{sup 11}C]MPDX for mapping adenosine A{sub 1} receptors by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ishiwata, Kiichi; Kimura, Yuichi; Oda, Keiichi; Kawamura, Kazunori; Ishii, Kenji; Senda, Michio [Tokyo Metropolitan Inst. of Gerontology (Japan). Positron Medical Center; Nariai, Tadashi; Wakabayashi, Shinichi [Tokyo Medical and Dental Univ. (Japan). School of Medicine; Shimada, Junichi [Kyowa Hakko Kogyo Co. Ltd., Tokyo (Japan). Pharmaceutical Research Inst.

    2002-09-01

    In previous in vivo studies with mice, rats and cats, we have demonstrated that [{sup 11}C]MPDX ([1-methyl-{sup 11}C]8-dicyclopropylmethyl-1-methyl-3-propylxanthine) is a potential radioligand for mapping adenosine A{sub 1} receptors of the brain by positron emission tomography (PET). In the present study, we performed a preclinical study. The radiation absorbed-dose by [{sup 11}C]MPDX in humans estimated from the tissue distribution in mice was low enough for clinical use, and the acute toxicity and mutagenicity of MPDX were not found. The monkey brain was clearly visualized by PET with [{sup 11}C]MPDX. We have concluded that [{sup 11}C]MPDX is suitable for mapping adenosine A{sub 1} receptors in the human brain by PET. (author)

  6. 18F-2-Deoxy-2-Fluoro-D-Glucose Positron Emission Tomography: Computed Tomography for Preoperative Staging in Gastric Cancer Patients

    OpenAIRE

    Youn, Seok Hwa; Seo, Kyung Won; Lee, Sang Ho; Shin, Yeon Myung; Yoon, Ki Young

    2012-01-01

    Purpose The use of 18F-2-deoxy-2-fluoro-D-glucose positron emission tomography-computed tomography as a routine preoperative modality is increasing for gastric cancer despite controversy with its usefulness in preoperative staging. In this study we aimed to determine the usefulness of preoperative positron emission tomography-computed tomography scans for staging of gastric cancer. Materials and Methods We retrospectively analyzed 396 patients' positron emission tomography-computed tomography...

  7. New developments in molecular imaging: positron emission tomography time-of-flight (TOF-PET); Nuevos desarrollos en imagen molecular: Tomografia por Emision de Positrones con Teimpo de Vuelo (TOF-PET)

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, P.; Couce, B.; Iglesias, A.; Lois, C.

    2011-07-01

    Positron Emission tomography (PET) in increasingly being used in oncology for the diagnosis and staging of disease, as well as in monitoring response to therapy. One of the last advances in PET is the incorporation of Time-of-Flight (TOF) information, which improves the tomographic reconstruction process and subsequently the quality of the final image. In this work, we explain the principles of PET and the fundamentals of TOF-PET. Clinical images are shown in order to illustrate how TOF-PET improves the detectability of small lesions, particularly in patients with high body mass index. (Author) 20 refs.

  8. The fast method of Cu-porphyrin complex synthesis for potential use in positron emission tomography imaging

    Science.gov (United States)

    Kilian, Krzysztof; Pęgier, Maria; Pyrzyńska, Krystyna

    2016-04-01

    Porphyrin based photosensitizers are useful agents for photodynamic therapy and fluorescence imaging of cancer. Additionally, porphyrins are excellent metal chelators, forming stable metalo-complexes and 64Cu isotope can serve as a positron emitter (t1/2 = 12.7 h). The other advantage of 64Cu is its decay characteristics that facilitates the use of 64Cu-porphyrin complex as a therapeutic agent. Thus, 64Cu chelation with porphyrin photosensitizer may become a simple and versatile labeling strategy for clinical positron emission tomography. The present study reports a convenient method for the synthesis of Cu complex with tetrakis(4-carboxyphenyl)porphyrin (TCPP). The experimental conditions for labeling, such as the metal-to-ligand molar ratio, pH and time of reaction were optimized to achieve a high complexation efficiency in a short period of time as possible. In order to accelerate the metallation, the use of substitution reactions of cadmium or lead porphyrin and the presence of reducing agent, such as ascorbic acid, hydroxylamine and flavonoid - morin, were evaluated. The optimum conditions for the synthesis of the copper complex were borate buffer at pH 9 with the addition of 10-fold molar excess, with respect to Cu2 + ions and TCPP and ascorbic acid which resulted in reduction of the reaction time from 30 min to below 1 min.

  9. Dose absorbed by technologists in positron emission tomography procedures with FDG

    Directory of Open Access Journals (Sweden)

    Ademir Amaral

    2007-09-01

    Full Text Available The objective of this work was to evaluate radiation doses delivered to technologists engaged in different tasks involving positron emission tomography (PET studies with FDG (fluorodeoxyglucose. This investigation was performed in two French nuclear medicine departments, which presented significant differences in their arrangements and radiation safety conditions. Both centers administered about 300 MBq per PET/CT study, although only one of them is a dedicated clinical PET center. Dose equivalent Hp(10 and skin dose Hp(0.07 were measured using Siemens electronic personnel dosimeters. For assessment dose absorbed by hands during drawing up of tracer and injection into the patient, a Polimaster wristwatch gamma dosimeter was employed. Absorbed dose and the time spent during each investigated task were recorded for a total of 180 whole-body PET studies. In this report, the methodology employed, the results and their radioprotection issues are presented as well as discussed.O objetivo deste trabalho foi o de avaliar doses absorvidas por profissionais de saúde em diferentes tarefas relacionadas à tomografia por emissão de pósitrons com [18F]-FDG (fluordesoxiglicose. Esta pesquisa foi realizada em dois centros de medicina nuclear na França, os quais apresentavam diferenças significativas em sua organização e radioproteção. Esses centros aplicavam aproximadamente 300 MBq por exame PET/CT, embora apenas um deles correspondesse a um serviço de medicina nuclear dedicado a exames por PET. A dose equivalente (Hp(10 e a dose na pele Hp(0,07 foram medidas usando dosímetros eletrônicos (Siemens. Para avaliação da dose nas mãos do tecnologista durante a preparação do radiofármaco e durante injeção no paciente, um dosímetro tipo relógio de pulso (Polimaster foi empregado. A dose absorvida e o tempo empregado durante cada tarefa foram registrados para um total de 180 exames de corpo inteiro através da PET. Neste trabalho, a metodologia

  10. Quantitative evaluation of regional substrate metabolism in the human heart by positron emission tomography

    International Nuclear Information System (INIS)

    Meaning interpretation of metabolic images obtained by positron emission tomography for evaluation of cardiac disease requires a knowledge of the normal variation in regional myocardial substrate metabolism. Recent studies with fluorine-18 (F-18) fluorodeoxyglucose suggest inhomogeneity of myocardial glucose metabolism in the normal human heart, which may relate to substrate availability. Therefore, quantitative evaluation of myocardial oxidative metabolism and glucose metabolism, as derived by dynamic positron emission tomography with carbon-11 (C-11) acetate and F-18 fluorodeoxyglucose, was performed in nine healthy male volunteers. All were studied under tightly controlled metabolic conditions of hyperinsulinemic-euglycemic clamping with and without a concurrent lipid emulsion infusion. Significant inhomogeneity of regional glucose metabolism was noted although it was less than that described under fasting conditions. Glucose utilization was 13% lower in the septum compared with the lateral wall both without and with lipid infusion (0.34 vs. 0.39 mumol/g per min, respectively, p less than 0.05; and 0.33 vs. 0.38 mumol/g per min, respectively, (p less than 0.05)). Relatively decreased septal glucose utilization could not be explained by decreased metabolic demand because C-11 clearance constants were marginally higher in the septum than in the lateral wall in both studies (0.055 vs. 0.054 per min, respectively, p = NS; and 0.061 vs. 0.056 per min, respectively,(p less than 0.05)). Relatively decreased septal glucose utilization could reflect regional variation in substrate use and possible preferential free fatty acid utilization by the septum. These data provide a useful framework for assessing altered cardiac metabolism in disease and support standardization of metabolic conditions during metabolic imaging with positron emission tomography

  11. Quantitative evaluation of regional substrate metabolism in the human heart by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, R.J.; Herman, W.H.; Kalff, V.; Molina, E.; Wolfe, E.R.; Hutchins, G.; Schwaiger, M. (Department of Internal Medicine, University of Michigan Hospitals, Ann Arbor (USA))

    1991-07-01

    Meaning interpretation of metabolic images obtained by positron emission tomography for evaluation of cardiac disease requires a knowledge of the normal variation in regional myocardial substrate metabolism. Recent studies with fluorine-18 (F-18) fluorodeoxyglucose suggest inhomogeneity of myocardial glucose metabolism in the normal human heart, which may relate to substrate availability. Therefore, quantitative evaluation of myocardial oxidative metabolism and glucose metabolism, as derived by dynamic positron emission tomography with carbon-11 (C-11) acetate and F-18 fluorodeoxyglucose, was performed in nine healthy male volunteers. All were studied under tightly controlled metabolic conditions of hyperinsulinemic-euglycemic clamping with and without a concurrent lipid emulsion infusion. Significant inhomogeneity of regional glucose metabolism was noted although it was less than that described under fasting conditions. Glucose utilization was 13% lower in the septum compared with the lateral wall both without and with lipid infusion (0.34 vs. 0.39 mumol/g per min, respectively, p less than 0.05; and 0.33 vs. 0.38 mumol/g per min, respectively, (p less than 0.05)). Relatively decreased septal glucose utilization could not be explained by decreased metabolic demand because C-11 clearance constants were marginally higher in the septum than in the lateral wall in both studies (0.055 vs. 0.054 per min, respectively, p = NS; and 0.061 vs. 0.056 per min, respectively,(p less than 0.05)). Relatively decreased septal glucose utilization could reflect regional variation in substrate use and possible preferential free fatty acid utilization by the septum. These data provide a useful framework for assessing altered cardiac metabolism in disease and support standardization of metabolic conditions during metabolic imaging with positron emission tomography.

  12. Noninvasive measurement of liver regeneration with positron emission tomography and [2-11C]thymidine

    International Nuclear Information System (INIS)

    The feasibility of liver regeneration determination with [2-11C]thymidine and positron emission tomography was investigated in partially hepatectomized rats. Serial tomographic scans were performed over a 120-minute period after injection of [2-11C]thymidine together with tritium-labeled thymidine. Within 10 minutes after injection, positron emission tomography scans showed a twofold higher hepatic uptake in regenerating than in nonregenerating livers. Time-activity curves over the liver area indicated that the maximal uptake was followed by a faster decrease of 11C radioactivity in controls than in regenerating animals, so that total 11C activity remaining in the liver at 120 minutes accounted for 68% of maximum in regenerating and only 38% in controls. Tissue distribution studies performed at 120 minutes showed that total 11C radioactivity, expressed in percent injected dose per gram, was six times higher in regenerating livers than in controls (0.62% ± 0.07% in regenerating livers and 0.10% ± 0.03% in nonregenerating livers; P less than 0.001) and correlated with 3H radioactivity measured in the nuclear fraction (r = 0.92; P less than 0.001). When the hepatic uptake was expressed in percent of dose per organ, the difference between both groups increased (2.31% ± 0.23% in regenerating livers and 0.29% ± 0.02% in nonregenerating livers; P less than 0.001) because of higher weight of regenerating livers than of nonregenerating livers (3.83 ± 0.11 g in regenerating livers and 2.96 ± 0.16 g in nonregenerating livers; P less than 0.001). In other organs examined, no difference in 11C radioactivity was found between the two groups of rats. These results indicated the potential usefulness of [2-11C]thymidine and positron emission tomography for noninvasive measurement of liver regeneration

  13. A new positron emission particle tracking facility at iThemba LABS

    International Nuclear Information System (INIS)

    Positron emission particle tracking (PEPT) has become a powerful tool for in-situ characterisation of particulate flow within aggressive industrial environments, such as tumbling mills and powder mixers. PEPT is based on the tracking of a single tracer particle which has been labelled with a radionuclide that decays via β decay. The location of the particle is obtained by the triangulation of events associated with the detection of pairs of annihilation γ rays in a modified 'positron camera'. One of the challenges facing PEPT is associated with labelling sub-millimetre sized particles which would allow studies in systems of finer particulate flow, such as flotation cells. The Positron Imaging Centre at the University of Birmingham is currently the only operational PEPT facility in the world. We are presently installing a PEPT laboratory at the iThemba LABS cyclotron facility in Cape Town. Details of this new facility will be presented, together with a flavour of recent PEPT data obtained in Birmingham, and results from our accelerator-based studies at iThemba LABS which are aimed at extending the state-of-the-art in the size and type of labelled tracer particles for PEPT work. (author)

  14. Human hemispheric infarction studied by positron emission tomography and the 150 continuous inhalation technique

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) offers an entirely new approach to the study of the pathophysiology of cerebral ischemic disorders. This is so because for the first time it is possible to obtain functional tomographic images that represent cerebral perfusion and metabolism in a regional basis. We report here a study of cerebral blood flow and oxygen extraction by means of the 15O inhalation technique in a large number of human hemispheric infarctions. PET imaging with this non-invasive technique has permitted the description of hitherto unreported focal patterns of changes in the CBF/EO2 couple that may have important pathophysiologic and prognostic implications

  15. Whole Body Muscle Activity during the FIFA 11+ Program Evaluated by Positron Emission Tomography

    OpenAIRE

    Nakase, Junsuke; Inaki, Anri; Mochizuki, Takafumi; Toratani, Tatsuhiro; Kosaka, Masahiro; Ohashi, Yoshinori; Taki, Junichi; Yahata, Tetsutaro; Kinuya, Seigo; Tsuchiya, Hiroyuki

    2013-01-01

    Purpose This study investigated the effect of the FIFA 11+ warm-up program on whole body muscle activity using positron emission tomography. Methods Ten healthy male volunteers were divided into a control group and a group that performed injury prevention exercises (The 11+). The subjects of the control group were placed in a sitting position for 20 min and 37 MBq of 18F-fluorodeoxyglucose (FDG) was injected intravenously. The subjects then remained seated for 45 min. The subjects of the exer...

  16. Dead time correction in positron emission tomograph. A method using single photon rate

    Energy Technology Data Exchange (ETDEWEB)

    Senda, Michio; Yonekura, Yoshiharu; Mukai, Takao; Fujita, Toru; Torizuka, Kanji

    1987-06-01

    The count rate linearity and dead time count losses were evaluated in Positologica III, a wholebody multislice positron emission tomograph, using several kinds of phantoms. A wide variation was observed in the relationship between count loss and true coincidence count rate depending on the source distribution, and the dead time correction using the count rate itself was unsuccessful. Since most count losses of this PET scanner occur when the single photon signals were encoded at the circuitry, we measured the single rate to correct for the count loss. This method enabled dead time correction independent of the distribution of source and attenuation material.

  17. Time stamp generation with inverse FIR filters for Positron Emission Tomography

    International Nuclear Information System (INIS)

    Photon coincidence detection is the process by which Positron Emission Tomography (PET) works. This requires the determination of the time of impact of each coincident photon at the detector system, also known as time stamp. In this work, the timestamp was generated by means of digital time-domain deconvolution with FIR filters for a INa(Tl) based system. The detector deadtime was reduced from 350 ns to 175 ns while preserving the system's energy resolution and a direct relation between the amount of light collected and the temporal resolution was found.(author)

  18. Risk of malignancy in thyroid incidentalomas detected by (18)f-fluorodeoxyglucose positron emission tomography

    DEFF Research Database (Denmark)

    Soelberg, Kerstin; Bonnema, Steen Joop; Brix, Thomas Heiberg;

    2012-01-01

    Background: The expanding use of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) has led to the identification of increasing numbers of patients with an incidentaloma in the thyroid gland. We aimed to review the proportion of incidental thyroid cancers found by (18)F-FDG PET...... uptake, 7 of whom (4.4%) had thyroid malignancy. In the eight studies reporting individual maximum standardized uptake values (SUV(max)), the mean SUV(max) was 4.8 (standard deviation [SD] 3.1) and 6.9 (SD 4.7) in benign and malignant lesions, respectively (p...

  19. Receptor-specific positron emission tomography radiopharmaceuticals: 75Br-labeled butyrophenone neuroleptics

    International Nuclear Information System (INIS)

    Cerebral dopaminergic D2 receptors are involved in several common disease states, such as schizophrenia, Parkinson's disease, and Huntington's chorea. The use of radiolabeled D2 receptor-binding ligands with positron emission tomography (PET) to noninvasively quantitate D2 receptor densities thus has potential application in medicine. Butyrophenone neuroleptics have a high in vitro and in vivo binding affinity for cerebral D2 receptors, and due to the useful chemical and nuclear decay properties of 74Br (76% β+, half-life = 1.6 h), the authors have evaluated radiobrominated bromospiperone (BSP), brombenperidol (BBP), and bromperidol (BP) as radiopharmaceuticals for use with PET

  20. A Charge-Sensitive Amplifier Associated with APD or PMT for Positron Emission Tomography Scanners

    OpenAIRE

    Mathez, H; Russo, P.; Lu, G.-N.; Pittet, P.; Quiquerez, L.; Lecoq, J.; Bohner, G.

    2010-01-01

    We present a Charge-Sensitive Amplifier (CSA) to be coupled with a 511-KeV 2-photon detector for positron emission tomography scanners. The circuit has been designed to be associated with an Avalanche Photodiode (APD) or Photo-Multiplier Tube (PMT) with large capacitance. It is a two-stage structure. The input stage consists of a foldedcascode fully-differential part and a common-mode feedback (CMFB) circuit. The output stage employs complementary source followers. The amplifier has been desi...

  1. A Lower-Cost High-Resolution LYSO Detector Development for Positron Emission Mammography (PEM)

    OpenAIRE

    Ramirez, Rocio A.; Zhang, Yuxuan; Liu, Shitao; Li, Hongdi; Baghaei, Hossain; An, Shaohui; Wang, Chao; Jan, Meei-Ling; Wong, Wai-Hoi

    2009-01-01

    In photomultiplier-quadrant-sharing (PQS) geometry for positron emission tomography applications, each PMT is shared by four blocks and each detector block is optically coupled to four round PMTs. Although this design reduces the cost of high-resolution PET systems, when the camera consists of detector panels that are made up of square blocks, half of the PMT’s sensitive window remains unused at the detector panel edge. Our goal was to develop a LYSO detector panel which minimizes the unused ...

  2. Flip-flop phenomenon in systemic sclerosis on fluorodeoxyglucose positron emission tomography/computed tomography

    International Nuclear Information System (INIS)

    Systemic sclerosis (SSc) is a rare autoimmune disease, which may affect multiple organ systems. Fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) can demonstrate the degree and anatomical extent of involvement in the entire body and coexisting malignancies in connective tissue diseases. We present a case of SSc with an increased 18F-FDG uptake in the cutaneous and subcutaneous tissues even higher than the neighboring skeletal muscles (“flip-flop phenomenon,” that is, an increased 18F-FDG uptake in the skin but a decreased 18F-FDG uptake in the skeletal muscles)

  3. Benign breast lesions detected by positron emission tomography-computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Benveniste, Ana P., E-mail: apbenveniste@mdanderson.org [Department of Diagnostic Radiology,The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Yang, Wei, E-mail: wyang@mdanderson.org [Department of Diagnostic Radiology,The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Benveniste, Marcelo F., E-mail: mfbenveniste@mdanderson.org [Department of Diagnostic Radiology,The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Mawlawi, Osama R., E-mail: omawlawi@mdanderson.org [Department of imaging physics, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Marom, Edith M., E-mail: emarom@mdanderson.org [Department of Diagnostic Radiology,The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    {sup 18}F-fluorodeoxyglucose positron emission computed tomography (FDG PET-CT) is widely used in the initial staging and response evaluation of patients with malignancy. This review describes a spectrum of benign breast findings incidentally detected by FDG PET-CT at staging that may be misinterpreted as malignancy. We describe the pattern of distribution and intensity of FDG uptake in a spectrum of benign breast diseases with their corresponding typical morphological imaging characteristics to help the nuclear medicine physician and/or general radiologist identify benign lesions, avoiding unnecessary breast imaging work-up and biopsies.

  4. Positron Emission Tomography Imaging of Tumor Angiogenesis with a 66Ga-Labeled Monoclonal Antibody

    OpenAIRE

    Engle, Jonathan W.; Hong, Hao; Zhang, Yin; Valdovinos, Hector F.; Myklejord, Duane V.; Barnhart, Todd E.; Theuer, Charles P.; Robert J. Nickles; Cai, Weibo

    2012-01-01

    The goal of this study was to develop a 66Ga-based positron emission tomography (PET) tracer for non-invasive imaging of CD105 expression during tumor angiogenesis, a hallmark of cancer. 66Ga was produced using a cyclotron with natZn or isotopically enriched 66Zn targets. TRC105, a chimeric anti-CD105 monoclonal antibody, was conjugated to 2-S-(4-isothiocyanatobenzyl)-1, 4, 7-triazacyclononane-1, 4, 7-triacetic acid (p-SCN-Bn-NOTA) and labeled with 66Ga. No difference in CD105 binding affinit...

  5. Positron Emission Tomography-Scanner at Children`s Hospital of Michigan at Detroit, Michigan

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The Department of Energy has prepared an environmental assessment (EA), DOE/EA-0795, to support the DOE decision to provide a grant of $7,953,600 to be used in support of a proposed Positron Emission Tomography Scanner at Children`s Hospital of Michigan at Detroit, Michigan. Based upon the analysis in the EA, DOE has determined that the proposed action is not a major Federal action significantly affected the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI).

  6. Chemical neuroanatomy and in vitro receptor autoradiography: A basis for cerebral positron emission tomography

    International Nuclear Information System (INIS)

    We review chemical neuroanatomy and in vitro receptor (IVG) autoradiography as tools for the development of methods suitable for positron emission tomography (PET) studies. The organizations of monoaminergic, cholinergic, γ-aminobutyric acidergic (GABA), and excitatory amino acidergic (EAA) pathways within the central nervous system are summarized, as is the presently accepted classification of GABA and EAA receptors. We describe the technique of IVG and discuss its unique advantages for the selection of possible PET methods. Finally, we discuss receptor changes in Huntington's disease and olivopontocerebellar atrophy, two human diseases for which IVG has suggested possible targets for PET imaging

  7. Caffeine and human cerebral blood flow: A positron emission tomography study

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow (CBF) in humans. A mean dose of 250 mg of caffeine produced approximately a 30% decrease in whole brain CBF; regional differences in caffeine effect were not observed. Pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease. Caffeine decreased paCO2 and increased systolic blood pressure significantly; the change in paCO2 did not account for the change in CBF. Smaller increases in diastolic blood pressure, heart rate, plasma epinephrine and norepinephrine, and subjectively reported anxiety were also observed

  8. Diagnosis of a cardiac angiosarcoma by fluorine-18 fluordeoxyglucose positron emission tomography

    International Nuclear Information System (INIS)

    Cardiac angiosarcoma is a rare tumour entity with a poor prognosis. Early detection is difficult but important for the further course of the disease. We report on a young patient with a tumour of unknown origin and dignity of the right atrium. Magnetic resonance imaging, CT and echocardiography were sufficient in localisation, but no statement on the dignity was possible. Furthermore, staging led to ambiguous results. Malignancy could be proved by fluorine-18 fluordeoxyglucose positron emission tomography, leading to early surgery. Histology revealed a poorly differentiated angiosarcoma. (orig.)

  9. Characterisation of beta(2)-adrenoceptors, using the agonist [C-11]formoterol and positron emission tomography

    OpenAIRE

    Visser, T J; van Waarde, Aaren; Doze, P; Elsinga, P.H.; van der Mark, Thomas W.; Kraan, Jan; Ensing, Kees; Vaalburg, W.

    1998-01-01

    The agonist radioligand N-[2-hydroxy-5-[1-hydroxy-2-[[2-(4-[C-11]-methoxyphenyl)-1-methylethyl]amino]ethyl]phenyl]formamide ([C-11]formoterol) was synthesised in order to test its ability to visualise pulmonary beta(2)-adrenoceptors in vivo, with positron emission tomography (PET). Formoterol was labelled via reaction of a dibenzyl-protected precursor with [C-11]CH3I. Subsequent deprotection with Pd/C and H-2 yielded [C-11]formoterol in 5-15% (corrected for decay) and the specific activity ra...

  10. Positron emission tomography/computed tomography for optimized colon cancer staging and follow up

    DEFF Research Database (Denmark)

    Engelmann, Bodil Elisabeth; Loft, Annika; Kjær, Andreas;

    2014-01-01

    OBJECTIVES: Optimal management of colon cancer (CC) requires detailed assessment of extent of disease. This study prospectively investigates the diagnostic accuracy of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (PET/CT) for staging and detection of recurrence....../CT diagnosed all relapses detected during the first 2 years. High preoperative TIMP-1 levels were associated with significant hazards toward risk of recurrence and shorter overall survival. CONCLUSIONS: This study indicates PET/CT as a valuable tool for staging and follow up in CC. TIMP-1 provided prognostic...

  11. Brain dopaminergic system changes in drug addiction: a review of positron emission tomography findings.

    Science.gov (United States)

    Hou, Haifeng; Wang, Chunyan; Jia, Shaowei; Hu, Shu; Tian, Mei

    2014-10-01

    Dopamine (DA) is considered crucial for the rewarding effects of drugs of abuse, but its role in addiction remains unclear. Positron emission tomography (PET) is the first technology used for in vivo measurement of components of the dopaminergic system in the human brain. In this article, we review the major findings from PET imaging studies on the involvement of DA in drug addiction, including presynaptic DA synthesis, vesicular monoamine transporter 2, the DA transporter, and postsynaptic DA receptors. These results have corroborated the role of DA in addiction and increased the understanding of its underlying mechanisms. PMID:25260796

  12. Positron Emission Tomography-Scanner at Children's Hospital of Michigan at Detroit, Michigan

    International Nuclear Information System (INIS)

    The Department of Energy has prepared an environmental assessment (EA), DOE/EA-0795, to support the DOE decision to provide a grant of $7,953,600 to be used in support of a proposed Positron Emission Tomography Scanner at Children's Hospital of Michigan at Detroit, Michigan. Based upon the analysis in the EA, DOE has determined that the proposed action is not a major Federal action significantly affected the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI)

  13. Cerebrospinal fluid analysis detects cerebral amyloid-β accumulation earlier than positron emission tomography

    OpenAIRE

    Palmqvist, Sebastian; Mattsson, Niklas; Hansson, Oskar; ,

    2016-01-01

    See Rabinovici (doi:10.1093/brain/aww025) for a scientific commentary on this article. Cerebral accumulation of amyloid-β is thought to be the starting mechanism in Alzheimer’s disease. Amyloid-β can be detected by analysis of cerebrospinal fluid amyloid-β42 or amyloid positron emission tomography, but it is unknown if any of the methods can identify an abnormal amyloid accumulation prior to the other. Our aim was to determine whether cerebrospinal fluid amyloid-β42 change before amyloid PET ...

  14. Preparation of radiopharmaceuticals labelled with bromine positron emitting isotopes for the study of dopaminergic receptors of the central nervous system using positron emission tomography

    International Nuclear Information System (INIS)

    The in vivo study of dopaminergic receptors of the central nervous system using positron emission tomography requires the preparation of radiopharmaceuticals labelled with β+ emitting isotopes. The chemical and pharmacological properties of these ligands are evaluated. Cyclotron produced 75 and 76 bromine β+ emitting isotopes are incorporated into dopaminergic ligands by electrophilic substitution using peracetic acid in a no-carrier added form. Purity, lipophilicity and specific activity are analyzed. Pharmacological criteria (specificity, saturability, displacement, localization) required for ligand-receptor binding studies are evaluated in vitro on striatal membranes and in vivo in the rat. Positron emission tomographic studies show that the study of dopaminergic D2 receptors is possible using 75 and 76 bromine labelled bromospiperone and bromolisuride. These ligands are used in physiological and pharmacological studies of the central nervous system

  15. Multitracer study with positron emission tomography in Creutzfeldt-Jakob disease

    International Nuclear Information System (INIS)

    During the period February 1997 to April 2000, 15 patients with clinical symptoms of Creutzfeldt-Jakob disease (CJD) were referred to Uppsala University PET Centre. Positron emission tomography (PET) was performed to detect characteristic signs of the disease, e.g. neuronal death and/or astrocytosis in the brain. The examinations were performed in one session starting with oxygen-15 labelled water scan to measure regional cerebral blood flow, followed by imaging with the monoamine oxidase B inhibitor N-[11C-methyl]-L-deuterodeprenyl (DED) to assess astrocytosis in the brain and finally imaging with fluorine-18 2-fluorodeoxyglucose (FDG) to assess regional cerebral glucose metabolism (rCMRglu). Nine of the patients fulfilled the clinical criteria of probable CJD. In eight of them, FDG and DED imaging revealed, in comparison with normal controls, a typical pattern characterized by a pronounced regional decrease (2SD) in DED binding, indicating astrocytosis. These changes were most pronounced in the cerebellum and the frontal, occipital and parietal cortices, whereas the pons, the thalamus and the putamen were less affected and the temporal cortex appeared unaffected. The cerebral blood flow showed a pattern similar to that observed with FDG. In the ninth patient, analysis with DED was not possible. The diagnosis of definite CJD according to international consensus criteria was confirmed in six of these patients. In one patient with probable CJD, protease-resistant prion protein (PrPres) could not be demonstrated. In two patients with probable CJD, autopsy was not allowed. Computed tomography and magnetic resonance imaging, performed in four and seven of these nine patients respectively, showed unspecific, mainly atrophic changes. In six other patients, the PET examinations gave a different pattern. In three of them, high rCMRglu was noticed in parts of the brain, particularly in the temporal lobes and basal ganglia, which could suggest encephalitis. One of the

  16. Multitracer study with positron emission tomography in Creutzfeldt-Jakob disease

    Energy Technology Data Exchange (ETDEWEB)

    Engler, Henry [Uppsala University PET Centre, Uppsala University Hospital, SE 751 85 Uppsala (Sweden); Department of Neurology, Uppsala University Hospital, Uppsala (Sweden); Lundberg, Per Olov [Department of Neurology, Uppsala University Hospital, Uppsala (Sweden); Ekbom, Karl [Department of Neurology, Huddinge University Hospital, Stockholm (Sweden); Nennesmo, Inger [Department of Pathology, Huddinge University Hospital, Stockholm (Sweden); Nilsson, Anna; Bergstroem, Mats; Hartvig, Per; Laangstroem, Bengt [Uppsala University PET Centre, Uppsala University Hospital, SE 751 85 Uppsala (Sweden); Tsukada, Hideo [Hamamatsu Photonics K.K.Central Research Lab, Hamakita City (Japan)

    2003-01-01

    During the period February 1997 to April 2000, 15 patients with clinical symptoms of Creutzfeldt-Jakob disease (CJD) were referred to Uppsala University PET Centre. Positron emission tomography (PET) was performed to detect characteristic signs of the disease, e.g. neuronal death and/or astrocytosis in the brain. The examinations were performed in one session starting with oxygen-15 labelled water scan to measure regional cerebral blood flow, followed by imaging with the monoamine oxidase B inhibitor N-[{sup 11}C-methyl]-L-deuterodeprenyl (DED) to assess astrocytosis in the brain and finally imaging with fluorine-18 2-fluorodeoxyglucose (FDG) to assess regional cerebral glucose metabolism (rCMR{sub glu}). Nine of the patients fulfilled the clinical criteria of probable CJD. In eight of them, FDG and DED imaging revealed, in comparison with normal controls, a typical pattern characterized by a pronounced regional decrease (<2SD) in glucose brain metabolism, indicative of neuronal dysfunction; this was accompanied by a similar increase (>2SD) in DED binding, indicating astrocytosis. These changes were most pronounced in the cerebellum and the frontal, occipital and parietal cortices, whereas the pons, the thalamus and the putamen were less affected and the temporal cortex appeared unaffected. The cerebral blood flow showed a pattern similar to that observed with FDG. In the ninth patient, analysis with DED was not possible. The diagnosis of definite CJD according to international consensus criteria was confirmed in six of these patients. In one patient with probable CJD, protease-resistant prion protein (PrPres) could not be demonstrated. In two patients with probable CJD, autopsy was not allowed. Computed tomography and magnetic resonance imaging, performed in four and seven of these nine patients respectively, showed unspecific, mainly atrophic changes. In six other patients, the PET examinations gave a different pattern. In three of them, high rCMR{sub glu} was

  17. Are restrictions to behaviour of patients required following fluorine-18 fluorodeoxyglucose positron emission tomographic studies?

    International Nuclear Information System (INIS)

    The clinical use of positron emission tomography (PET) is expanding rapidly in most European countries. It is likely therefore that patients receiving the tracer fluorine-18 fluorodeoxyglucose (18FDG) will be discharged to come into contact with family members, members of the public and ward staff. There are few direct measurements on which to base any recommendations with regard to radiation protection, and so we have measured the dose rates from patients undergoing clinical PET examinations in our centre. Seventy-five patients who underwent whole-body and brain 18FDG PET examinations were studied. Dose rates were measured at 0.1, 0.5, 1.0 and 2.0 m from the mid thorax on leaving the department. The median administered activity was 323 MBq with a 95th percentile value of 360 MBq. The median dose rates measured at the four distances were 90.0, 35.0, 14.0 and 5.0 μSv h-1 (the median dose rates per unit administered activity at 2 h post injection were 0.31, 0.11, 0.04 and 0.02 μSv h-1 MBq-1). The corresponding 95th percentile values were 174.0, 69.0, 29.0 and 7.5 μSv h-1 (0.43, 0.2, 0.08 and 0.03 μSv h-1 MBq-1). A number of social situations were modelled and an annual dose limit of 1 mSv was used to determine whether restrictive behavioural advice was required. In the case of nursing staff on wards a value of 6 mSv was regarded as the annual limit, which translates to a daily limit of approximately 24 μSv. There is no need for restrictive advice for patients travelling by public or private transport when they leave the department 2 h after the administration of 18FDG. Similarly, there is no need for restrictive advice with regard to their contact with partners, work colleagues or children of any age, although it should be stressed that children should not accompany the patient to the scanning department. The only possible area of concern is in an oncology ward, where patients may be regularly referred for PET investigations and other high activity radionuclide

  18. A phase III clinical trial to evaluate the measurement of tumor proliferation using f-18 fluoro-3'-deoxy-3' -l-fluorothymidine (FLT) positron emission tomography in patients with lung cancer

    International Nuclear Information System (INIS)

    This study was performed to validate the efficacy of FLT-PET as a noninvasive tumor proliferation imaging method and the safety of FLT as a diagnostic radiopharmaceutical. A prospective, nonrandomized, phase III clinical trial was performed in a single center. Adult patient(pt)s with primary lung cancer with > 1.5 cm in size, scheduled to surgery after staging work-up were eligible. Before surgery, FLT-PET images were obtained using a PET/CT scanner at 1 hr after injection of 370 MBq FLT. Standardized uptake values (SUV) of tumor were measured using a threshold (80% of maxSUV) defined volume of interest. After surgery, Ki-67 values of tumor were measured by two pathologists who were blind to FLT-PET results. The primary endpoint of this study was a good correlation between the measurements of tumor proliferation by SUVs using FLT-PET and Ki-67 values (H0: = 0.5 vs H1: > 0.5, p 0.05) in tumors > 3 cm in size. In all 110 pts, 10 mild or moderate adverse reactions were recorded, but no reaction was considered to be related to FLT and all pts recovered. FLT-PET is an effective and safe imaging method to measure tumor proliferation in vivo

  19. Positron emission tomography with 2-deoxy-2-[18F]fluoro-d -glucose in patients with thyroid diseases : FDG PET in thyroid diseases

    OpenAIRE

    2011-01-01

    The aim of this thesis was to contribute to the field of positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) in benign and malignant diseases of the thyroid gland. The primary method used was review of retrospectively or prospectively enrolled patients referred for FDG PET at the Mayo Clinic, Rochester, MN, USA. PET findings were compared with the results of all other imaging, laboratory results and clinical information, as well as, extensive recording of follow-up i...

  20. Positron emission tomography in digestive neuroendocrine tumors: choice of the tracer; Apport de la tomographie par emission de positons dans les tumeurs endocrines digestives: choix du traceur

    Energy Technology Data Exchange (ETDEWEB)

    Taieb, D.; Tessonnier, L.; Mundler, O. [Centre Hospitalo-Universitaire de La Timone, Service Central de Biophysique et de Medecine Nucleaire, 13 - Marseille (France)

    2009-11-15

    Digestive endocrine tumors represent a heterogeneous group of neoplasm sharing common characteristics such as their high density of peptide receptors, their ability to take up amino acids and de-carboxylate them into biogenic amines and their low glycolytic activity. These features are used for nuclear imaging targeting. To date, somatostatin receptor scintigraphy is considered the 'gold standard' imaging procedure of well-differentiated tumors. Despite the significant contribution of SPECT/CT, the use of positron emission tomography imaging (PET) is growing rapidly. Three PET imaging modalities are currently available: {sup 68}Ga-labeled somatostatin analogs PET, {sup 18}F-dihydroxy-phenylalanine PET ({sup 18}F-DOPA) and {sup 18}F-deoxyglucose PET ({sup 18}F-F.D.G.). This article focuses on the current targets of molecular imaging and highlights the potential clinical applications of new targets. (authors)