WorldWideScience

Sample records for understood positron emission

  1. Positron emission tomography

    International Nuclear Information System (INIS)

    Reivich, M.; Alavi, A.

    1985-01-01

    This book contains 24 selections. Some of the titles are: Positron Emission Tomography Instrumentation, Generator Systems for Positron Emitters, Reconstruction Algorithms, Cerebral Glucose Consumption: Methodology and Validation, Cerebral Blood Flow Tomography Using Xenon-133 Inhalation: Methods and Clinical Applications, PET Studies of Stroke, Cardiac Positron Emission Tomography, and Use of PET in Oncology

  2. Positron emission tomography

    International Nuclear Information System (INIS)

    Iio, Masahiro

    1982-01-01

    Utilization of positron emission tomography was reviewed in relation to construction and planned construction of small-size medical cyclotrons, planned construction of positron cameras and utilization of short-lived radionuclides. (Chiba, N.)

  3. Cardiac positron emission tomography

    International Nuclear Information System (INIS)

    Eftekhari, M.; Ejmalian, G.

    2003-01-01

    Positron emission tomography is an intrinsically tool that provide a unique and unparalleled approach for clinicians and researchers to interrogate the heart noninvasively. The ability to label substances of physiological interest with positron-emitting radioisotopes has permitted insight into normal blood flow and metabolism and the alterations that occur with disease states. Positron emission tomography of the heart has evolved as a unique, noninvasive approach for the assessment of myocardial perfusion, metabolism, and function. Because of the intrinsic quantitative nature of positron emission tomography measurements as well as the diverse compounds that can be labeled with positron- emitting radioisotopes, studies with positron emission tomography have provided rich insight into the physiology of the heart under diverse conditions

  4. Positron emission tomography

    International Nuclear Information System (INIS)

    Paans, A.M.J.

    1981-01-01

    Positron emitting radiopharmaceuticals have special applications in in-vivo studies of biochemical processes. The combination of a cyclotron for the production of radionuclides and a positron emission tomograph for the registration of the distribution of radioactivity in the body enables the measurement of local radioactivity concentration in tissues, and opens up new possibilities in the diagnosis and examination of abnormalities in the metabolism. The principles and procedures of positron emission tomography are described and the necessary apparatus considered, with emphasis on the positron camera. The first clinical applications using 55 Co bloemycine for tumor detection are presented. (C.F.)

  5. Positron emission tomography

    NARCIS (Netherlands)

    Paans, AMJ

    Positron Emission Tomography (PET) is a method for determining biochemical and physiological processes in vivo in a quantitative way by using radiopharmaceuticals labelled with positron emitting radionuclides as C-11, N-13, O-15 and F-18 and by measuring the annihilation radiation using a

  6. Positron emission computed tomography

    International Nuclear Information System (INIS)

    Grover, M.; Schelbert, H.R.

    1985-01-01

    Regional mycardial blood flow and substrate metabolism can be non-invasively evaluated and quantified with positron emission computed tomography (Positron-CT). Tracers of exogenous glucose utilization and fatty acid metabolism are available and have been extensively tested. Specific tracer kinetic models have been developed or are being tested so that glucose and fatty acid metabolism can be measured quantitatively by Positron-CT. Tracers of amino acid and oxygen metabolism are utilized in Positron-CT studies of the brain and development of such tracers for cardiac studies are in progress. Methods to quantify regional myocardial blood flow are also being developed. Previous studies have demonstrated the ability of Positron-/CT to document myocardial infarction. Experimental and clinical studies have begun to identify metabolic markers of reversibly ischemic myocardium. The potential of Positron-CT to reliably detect potentially salvageable myocardium and, hence, to identify appropriate therapeutic interventions is one of the most exciting applications of the technique

  7. Positron emission tomography

    International Nuclear Information System (INIS)

    Yamamoto, Y.L.; Thompson, C.J.; Diksic, M.; Meyer, E.; Feindel, W.H.

    1984-01-01

    One of the most exciting new technologies introduced in the last 10 yr is positron emission tomography (PET). PET provides quantitative, three-dimensional images for the study of specific biochemical and physiological processes in the human body. This approach is analogous to quantitative in-vivo autoradiography but has the added advantage of permitting non-invasive in vivo studies. PET scanning requires a small cyclotron to produce short-lived positron emitting isotopes such as oxygen-15, carbon-11, nitrogen-13 and fluorine-18. Proper radiochemical facilities and advanced computer equipment are also needed. Most important, PET requires a multidisciplinary scientific team of physicists, radiochemists, mathematicians, biochemists and physicians. The most recent trends are reviewed in the imaging technology, radiochemistry, methodology and clinical applications of positron emission tomography. (author)

  8. 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.

  9. Tomography by positrons emission

    International Nuclear Information System (INIS)

    Mosconi, Sergio L.

    1999-01-01

    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 ( 11 C), of the oxygen ( 15 O), of the nitrogen ( 13 N) 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 11 C, 15 O, and 13 N, other isotopes that can be obtained of a generator as the 68 Ga and 82 Rb

  10. Positron emission tomography

    International Nuclear Information System (INIS)

    Bolwig, T.G.; Haunsoe, S.; Dahlgaard Hove, J.; Hesse, B.; Hoejgard, L.; Jensen, M.; Paulson, O.B.; Hastrup Svendsen, J.; Soelvsten Soerensen, S.

    1994-01-01

    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 ( 11 C), oxygen ( 15 O), and nitrogen ( 13 N) 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. Positronemisionstomografi

    Energy Technology Data Exchange (ETDEWEB)

    Bolwig, T.G.; Haunsoe, S.; Dahlgaard Hove, J.; Hesse, B.; Hoejgard, L.; Jensen, M.; Paulson, O.B.; Hastrup Svendsen, J.; Soelvsten Soerensen, S.

    1994-10-01

    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 ([sup 11]C), oxygen ([sup 15]O), and nitrogen ([sup 13]N) 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.).

  12. Positron emission mammography imaging

    OpenAIRE

    Moses, William W.

    2003-01-01

    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 mammogra...

  13. Positron emission tomography

    International Nuclear Information System (INIS)

    Lindback, Stig

    1995-01-01

    Positron Emission Tomography (PET) is an advanced nuclear medicine technique used for research at major centres. Unique diagnostic information is obtained from tomographic measurements of the biochemistry and physiology of tissues and organs. In theory, diseases are related to biochemical changes and these can be observed with PET long before any anatomical changes are detectable. In PET the radioactive component is a positron-emitting isotope or 'tracer'. The positrons annihilate with electrons in the body to produce two gamma rays 180° apart; coincidence detection of these gammas provides a very efficient method of determining the spatial distribution of the radioisotope tracer. Because physiological measurements are usually required in a single imaging session, very short-lived isotopes are used to label the tracer molecules; isotope production and labelling is usually carried out in situ. The most commonly used radionuclides are carbon- 11 (half-life 20 minutes), nitrogen-13 (10 minutes), oxygen-15 (2 minutes), and fluorine-18 (110 minutes). A PET system has three major components: - a particle accelerator with targets for production of the positron-emitting isotopes; - chemistry modules for synthesis and labelling of the desired tracers; - and a PET camera for in-vivo measurements of the distribution of the tracer in the body

  14. Positron emission tomography camera

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    A positron emission tomography camera having a plurality of detector rings positioned side-by-side or offset by one-half of the detector cross section around a patient area to detect radiation therefrom. Each ring contains a plurality of scintillation detectors which are positioned around an inner circumference with a septum ring extending inwardly from the inner circumference along each outer edge of each ring. An additional septum ring is positioned in the middle of each ring of detectors and parallel to the other septa rings, whereby the inward extent of all the septa rings may be reduced by one-half and the number of detectors required in each ring is reduced. The additional septa reduces the costs of the positron camera and improves its performance

  15. Positron Emission Tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Welch, M.J.

    1990-01-01

    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.

  16. Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Welch, M.J.

    1990-01-01

    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 camera

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    A positron emission tomography camera having a plurality of detector planes positioned side-by-side around a patient area to detect radiation. Each plane includes a plurality of photomultiplier tubes and at least two rows of scintillation crystals on each photomultiplier tube extend across to adjacent photomultiplier tubes for detecting radiation from the patient area. Each row of crystals on each photomultiplier tube is offset from the other rows of crystals, and the area of each crystal on each tube in each row is different than the area of the crystals on the tube in other rows for detecting which crystal is actuated and allowing the detector to detect more inter-plane slides. The crystals are offset by an amount equal to the length of the crystal divided by the number of rows. The rows of crystals on opposite sides of the patient may be rotated 90 degrees relative to each other

  18. Positron Emission Mammography imaging

    Energy Technology Data Exchange (ETDEWEB)

    Moses, W.W. E-mail: wwmoses@lbl.gov

    2004-06-01

    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.

  19. 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.

  20. Fundamentals of positron emission tomography

    International Nuclear Information System (INIS)

    Ostertag, H.

    1989-01-01

    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.) [de

  1. Positron emission tomography in oncology

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This report describes the current and potential uses of positron emission tomography in clinical medicine and research related to oncology. Assessment will be possible of metabolism and physiology of tumors and their effects on adjacent tissues. Specific probes are likely to be developed for target sites on tumors, including monoclonal antibodies and specific growth factors that recognize tumors. To date, most oncological applications of positron emission tomography tracers have been qualitative; in the future, quantitative metabolic measurements should aid in the evaluation of tumor biology and response to treatment

  2. 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...... is calculated from the NMF solution. The method is tested on a [18F]-Altanserin tracer ligand data set consisting of 5 healthy subjects. The results from using K-means clustering and NMF are compared to a sampled arterial TAC. The comparison is done by calculating the correlation with the arterial sampled TAC....

  3. Positron emission tomography takes lead

    International Nuclear Information System (INIS)

    Simms, R.

    1989-01-01

    Positron emission tomography (PET)'s ability to detect functional abnormalities before they manifest anatomically is examined and some of its most common applications are outlined. It is emphasised that when PET facility and Australian Nuclear Science and Technology Organization's national cyclotron are established at the Royal Prince Alfred Hospital, the availability of short-lived tracers such as oxygen 15, nitrogen 13 and fluorine 18 would improve the specificity of tests(e.g. for brain tumors or cardiac viability) further. Construction of the cyclotron will start shortly and is due to be completed and operating by the end of 1991

  4. Applications for positron emission mammography.

    Science.gov (United States)

    Weinberg, Irving N

    2006-01-01

    High resolution positron emission mammography (PEM) can address the current clinical needs of breast cancer patients and the requirements for future translational work. Combining the quantitative capabilities of positron emission tomography (PET) with millimeter resolution, PEM can image the earliest in situ forms of breast cancer as well as putative cancer precursor lesions (e.g., atypical ductal hyperplasia) whose behavior is important for prevention studies. The importance of the ability to detect intraductal cancer cannot be overemphasized, for several reasons: at least one-third of new cancers are detected at this intraductal stage, intervention at this stage represents the best opportunity for complete cure, and a significant number of invasive cancers contain an intraductal component. Without knowledge of the extent of the intraductal component, surgeons are unable to completely excise cancers about a third of the time, leading to unnecessary re-excisions or radiation therapy. Current investigations aimed at specifying best practices in radiotherapy of DCIS patients are stymied by the lack of objective quantitative methods of rapidly assessing response. Other future applications of PEM are suggested, including an information technology project built on PEM that promises to individualize therapy and facilitate surveillance of high risk populations. The high overall accuracy of PEM (i.e., both specificity and sensitivity) is an unusual and welcome development in the history of breast imaging. With this high accuracy, and continued technical innovation to reduce radiation dose, PEM may someday replace X-ray mammography as a first line approach to breast cancer detection.

  5. Positron Emission Mammotomography with Dual Planar Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Mark Smith; Raymond Raylman; Stanislaw Majewski

    2003-06-29

    Positron emission mammography (PEM) is usually performed with two stationary planar detectors above and below a compressed breast. There is image blurring normal to the detectors due to the limited angular range of the lines of response. Positron emission mammotomography (PEM-T) with dual planar detectors rotating about the breast can obtain complete angular sampling and has the potential to improve activity estimation.

  6. Positron emission tomography and migraine

    International Nuclear Information System (INIS)

    Chabriat, H.

    1992-01-01

    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 2 serotonin receptors can be studied in migraine patients with PET

  7. 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...

  8. Positron Emission Tomography - Computed Tomography (PET/CT)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Positron Emission Tomography - Computed Tomography (PET/CT) Positron emission tomography (PET) ... Emission Tomography – Computed Tomography (PET/CT)? What is Positron Emission Tomography – Computed Tomography (PET/CT) Scanning? Positron emission tomography, ...

  9. Positron emission tomography imaging--technical considerations

    International Nuclear Information System (INIS)

    Muehllehner, G.; Karp, J.S.

    1986-01-01

    Positron imaging instrumentation has improved rapidly in the last few years. Scanners currently under development are beginning to approach fundamental limits set by positron range and noncolinearity effects. This report reviews the latest developments in positron emission tomography (PET) instrumentation, emphasizing the development of coding schemes that reduce the complexity and cost of high-resolution scanners. The relative benefits of using time-of-flight (TOF) information is discussed as well. 68 references

  10. Scintillators for positron emission tomography

    International Nuclear Information System (INIS)

    Moses, W.W.; Derenzo, S.E.

    1995-09-01

    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

  11. Positron emission tomography in oncology

    International Nuclear Information System (INIS)

    Lecomte, R.; Bentourkia, M.; Benard, F.

    2002-01-01

    Positron Emission Tomography is a sophisticated molecular imaging technique, using a special scanner, that displays the functional status of tissues in the body at the cellular level (their metabolism). It is a diagnostic scan that provides the physician with information not available with traditional anatomic studies such as CT or MRI. PET can detect changes in cell function (disease) long before they are evident as physical (anatomic) changes seen on CT or MRI. In this way PET can add important information about many diseases allowing the physician to make a diagnosis often much earlier than with anatomic imaging techniques such as CT or MRI alone. In addition, in cases where an abnormality is noted on CT or MRI, PET can help differentiate benign changes from changes due to disease. PET scanning also typically images the entire body, unlike CT/MRI which is usually broken up into specific limited body section scans. All cells use glucose as an energy source but cancer cells use much more since they are growing much faster and out of control. This is the basis of imaging with F-18 FDG glucose, the radiotracer agent use in a PET oncology study. The abnormal, accelerated glucose used by cancer cells is detected by the PET scanner that processes the emissions from the F-18 FDG glucose by abnormally high levels of metabolism (tumor)

  12. Radiopharmaceutical chemistry for positron emission tomography

    NARCIS (Netherlands)

    Elsinga, PH

    Radiopharmaceutical chemistry includes the selection, preparation, and preclinical evaluation of radiolabeled compounds. This paper describes selection criteria for candidates for positron emission tomography (PET) investigations. Practical aspects of nucleophilic and electrophilic

  13. Positron emission tomography in epilepsy

    International Nuclear Information System (INIS)

    Hosokawa, Shinichi; Kato, Motohiro; Otsuka, Makoto; Kuwabara, Yasuo; Ichiya, Yuichi; Goto, Ikuo

    1989-01-01

    Positron emission tomography (PET) was performed with the 18 F-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)

  14. Clinical utility of positron emission mammography

    OpenAIRE

    Glass, Shannon B.; Shah, Zeeshan A.

    2013-01-01

    Several imaging modalities have been introduced over recent years to better screen for and stage breast cancer. Positron emission mammography (PEM) has been approved by the US Food and Drug Administration and introduced into clinical use as a diagnostic adjunct to mammography and breast ultrasonography. PEM has higher resolution and a more localized field of view than positron emission tomography–computed tomography and can be performed on patients to stage a newly diagnosed malignancy. Revie...

  15. Positron emission tomography studies of brain receptors

    International Nuclear Information System (INIS)

    Maziere, B.; Maziere, M.

    1991-01-01

    Probing the regional distribution and affinity of receptors in the brain, in vivo, in human and non human primates has become possible with the use of selective ligands labelled with positron emitting radionuclides and positron emission tomography (PET). After describing the techniques used in positron emission tomography to characterize a ligand receptor binding and discussing the choice of the label and the limitations and complexities of the in vivo approach, the results obtained in the PET studies of various neurotransmission systems: dopaminergic, opiate, benzodiazepine, serotonin and cholinergic systems are reviewed

  16. New Possibilities of Positron-Emission Tomography

    Science.gov (United States)

    Volobuev, A. N.

    2018-01-01

    The reasons for the emergence of the angular distribution of photons generated as a result of annihilation of an electron and a positron in a positron-emission tomograph are investigated. It is shown that the angular distribution of the radiation intensity (i.e., the probability of photon emission at different angles) is a consequence of the Doppler effect in the center-of-mass reference system of the electron and the positron. In the reference frame attached to the electron, the angular distribution of the number of emitted photons does not exists but is replaced by the Doppler shift of the frequency of photons. The results obtained in this study make it possible to extend the potentialities of the positron-emission tomograph in the diagnostics of diseases and to obtain additional mechanical characteristics of human tissues, such as density and viscosity.

  17. Positron emission tomography with Positome, 2

    International Nuclear Information System (INIS)

    Nukui, Hideaki; Yamamoto, Y.L.; Thompson, C.J.; Feindel, W.

    1979-01-01

    Positron emission tomography with Positome II using 68 Ga-EDTA was performed in cases with brain tumor and cerebral arteriovenous malformation. A significant focal uptake in static study and hemodynamic changes in dynamic study were noted in all cases except one case with intracranial lipoma. Comparing this method with sup(99m) Tc-pertechnetate cerebral image study and computerized axial tomography, the diagnostic rate for detecting brain tumor was almost equal in all of these three methods. However, detecting and localizing was easier and clearer in static positron emission tomography with 68 Ga-EDTA than in sup(99m) Tc-pertechnetate cerebral image and computerized axial tomography without infusion of contrast medium. Furthermore, static positron emission tomography with 68 Ga-EDTA was superior to computerized axial tomography without infusion of contrast medium for detecting cerebral arteriovenous malformation. Concerning dynamic positron emission tomography with 68 Ga-EDTA, semiquantitative values obtained by this method correlated well with findings of computerized axial tomography and was thought to be more precise and in detail than the findings of sup(99m) Tc-pertechnetate cerebral image study. Summation of the previous studies about dynamic positron emission tomography with 77 Kr in occlusive cerebrovascular disease is also reported. In conclusion, static positron emission tomography with 68 Ga-EDTA is a very useful diagnostic method for detecting and localizing brain tumor and cerebral arteriovenous malformation without any attendant complications. Furthermore, a good combination of static and dynamic positron emission tomography and computerized axial tomography appear to be outstandingly effective for not only detecting the lesion but also understanding the pathophysiological aspect in cases with various intracranial lesions. (author)

  18. Positron emission tomography imaging of gene expression

    International Nuclear Information System (INIS)

    Tang Ganghua

    2001-01-01

    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

  19. Clinical utility of positron emission mammography.

    Science.gov (United States)

    Glass, Shannon B; Shah, Zeeshan A

    2013-07-01

    Several imaging modalities have been introduced over recent years to better screen for and stage breast cancer. Positron emission mammography (PEM) has been approved by the US Food and Drug Administration and introduced into clinical use as a diagnostic adjunct to mammography and breast ultrasonography. PEM has higher resolution and a more localized field of view than positron emission tomography-computed tomography and can be performed on patients to stage a newly diagnosed malignancy. Review of mammograms together with magnetic resonance or PEM images improves detection of disease.

  20. Ionization and positron emission in giant quasiatoms

    International Nuclear Information System (INIS)

    Soff, G.; Reinhardt, J.; Reus, T. de; Wietschorke, K.H.; Schaefer, A.; Mueller, B.; Greiner, W.; Mueller, U.; Schlueter, P.

    1985-07-01

    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.)

  1. Is positron emission tomography useful in stroke?

    NARCIS (Netherlands)

    DeReuck, J; Leys, D; DeKeyser, J

    Positron emission tomography (PET) has been widely used in the study of stroke and related cerebrovascular diseases. It has shown the various stages leading to cerebral infarction and defined the significance of the ischaemic penumbra. PET scan can predict the clinical outcome of patients with acute

  2. Positron emission tomography in malignant haematological disease

    NARCIS (Netherlands)

    Schot, Bartholomeus Wilhelmus

    2007-01-01

    Positron emission tomography (PET) is a diagnostic technique with a promising role especially in the haemato-oncology. Although its use in the management ; of malignant lymphoma seems to be established already, much about the true potential and drawbacks of FDG-PET in this disease are still unknown.

  3. Features and applications of positron emission tomography

    International Nuclear Information System (INIS)

    Fan Mingwu

    1997-01-01

    Positron emission tomography, the so-called world's smartest camera, is based on a NaI or BGO detector and imaging of positron-emitting radioisotopes which are introduced as a tracer into the regional tissue or organ of interest. With the aid of a computer visual images of a series of these distributions can be built into a picture of the functional status of the tissue or organ being imaged. This highly accurate imaging technique is already widely used for clinical diagnostics heart disease, brain disorder, tumors and so on

  4. Positron emission tomography of the lung

    International Nuclear Information System (INIS)

    Wollmer, P.

    1984-01-01

    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)

  5. Positron emission tomography in movement disorders

    International Nuclear Information System (INIS)

    Martin, W.R.W.

    1985-01-01

    Positron emission tomography provides a method for the quantitation of regional function within the living human brain. Studies of cerebral metabolism and blood flow in patients with Huntington's disease, Parkinson's disease and focal dystonia have revealed functional abnormalities within substructures of the basal ganglia. Recent developments permit assessment of both pre-synaptic and post-synaptic function ion dopaminergic pathways. These techniques are now being applied to studies of movement disorders in human subjects

  6. Positron emission tomography of FDG in schizophrenia

    International Nuclear Information System (INIS)

    Sargent, T. III; Kusubov, N.

    1986-01-01

    The use of the Donner dynamic positron emission tomograph to study fluorodeoxyglucose labelled 18 F 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

  7. Methods and instrumentation for positron emission tomography

    International Nuclear Information System (INIS)

    Mandelkern, M.A.; Phelps, M.E.

    1988-01-01

    This paper reports on positron emission tomography (PET), a technique for the noninvasive measurement of local tissue concentrations of injected radioactive tracers. Tracer kinetics techniques can be applied to this information to quantify physiologic function in human tissue. In the tracer method, a pharmaceutical is labeled by a radioactive atom. When introduced into the subject that molecule follows a physiologic pathway. The space- and time-dependent distribution of the radionuclide is obtained via an imaging technique. If the radiopharmaceutical is sufficiently analogous to a natural substrate or other substance of interest, a quantitative image can be translated into a physiologic measurement

  8. Contribution of positron emission tomography in neurology

    International Nuclear Information System (INIS)

    Salmon, E.; Franck, G.

    1992-01-01

    Positron Emission Tomography (PET) is a scanner technique using tracers labelled with shortlived radioisotopes which allows to study and quantify human metabolic processes or drug pharmacology in vivo. The technique is first applied in physiological studies. Sleep, normal brain metabolism or cerebral activations have been studied. The pharmacological approach concerns both drug distribution in the human brain and blood flow or metabolic variations under treatment. Main neurological applications in pathology are cerebrovascular disorders, diseases leading to dementia, epilepsy, movement disorders, and brain tumors. In each field of application, PET gives unique and frequently early informations. It nicely combines both dynamic informations and measurement precision. (author)

  9. 77 FR 8262 - Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    Science.gov (United States)

    2012-02-14

    ...] Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs... Applications for Positron Emission Tomography (PET) Drugs.'' The draft guidance is intended to assist... draft guidance entitled ``Investigational New Drug Applications for Positron Emission Tomography (PET...

  10. F-18-fluorodeoxyglucose-positron emission tomography in colorectal cancer

    International Nuclear Information System (INIS)

    Joerg, L.; Langsteger, W.

    2002-01-01

    Whole-body positron emission tomography (PET) with the radiolabeled glucose analog F-18-fluorodeoxyglucose (F-18-FDG) is a sensitive diagnostic tool that images tumors based on increased uptake of glucose. Several recent publications have shown that F-18-fluorodeoxyglucose-positron emission tomography is more sensitive than computed-tomography (CT) in detecting colorectal cancer. In patients with increasing CEA (carcinoembryonic antigen) and no evidence of recurrent disease on CT F-18-fluorodeoxyglucose-positron emission tomography often detects recurrent cancer. In all, patient management seems to be changed in about 25 % of patients who undergo F-18-fluorodeoxyglucose-positron emission tomography in addition to standard staging procedure. Limited reports to date on both chemotherapy and radiotherapy support the role of F-18-fluorodeoxyglucose-positron emission tomography in assessing treatment response. Also regarding preoperative staging of primary colorectal cancer the literature is very limited. (author)

  11. The Positron Emission Tomography. A diagnostic technique

    International Nuclear Information System (INIS)

    Salvadori, P.

    2001-01-01

    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 [it

  12. 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...

  13. Positron Emission Tomography of the Heart

    Science.gov (United States)

    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.

  14. Positron emission tomography in drug development

    International Nuclear Information System (INIS)

    Rubin, R. H.; Fischman, A. J.

    1997-01-01

    There are four kinds of measurements that can be carried out with positron emission tomography (PET) that can contribute significantly to the process of drug development: pharmacodynamic measurement of tissue metabolism influenced by a given drug; precise measurements of tissue blood flow; tissue pharmacokinetics of a given drug following administration of a particular dose; and the temporal course of ligand-receptor interaction. One or more of these measurements can greatly improve the decision making involved in determining the appropriate dose of a drug, the clinical situations in which a drug might be useful, and the linkage of pharmacokinetics with pharmacodynamics, which is at the heart of effective drug development. The greater the potential of a particular compound as a therapeutic agent, the greater the potential for PET to contribute to the drug development process

  15. 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.

  16. Instrumentation optimization for positron emission mammography

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W. E-mail: wwmoses@lbl.gov; Qi Jinyi

    2004-07-11

    The past several years have seen designs for PET cameras optimized to image the breast, commonly known as Positron Emission Mammography (PEM) cameras. The guiding principal behind PEM instrumentation is that a camera whose field of view is restricted to a single breast has higher performance and lower cost than a conventional PET camera. The most common geometry is a pair of parallel planes of detector modules, although geometries that encircle the breast have also been proposed. The ability of the detectors to measure the depth of interaction (DOI) is also a relevant feature. This paper finds that while both the additional solid angle coverage afforded by encircling the breast and the decreased blurring afforded by the DOI measurement improve performance, for small lesions the ability to measure DOI is more important than the ability to encircle the breast.

  17. Positron emission tomography and basal ganglia functions

    International Nuclear Information System (INIS)

    Kato, Motohiro; Otsuka, Makoto; Taniwaki, Koukyo; Hosokawa, Shinichi; Kuwabara, Yasuo; Ichiya, Yuichi

    1990-01-01

    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

  18. Fundamental limits of positron emission mammography

    International Nuclear Information System (INIS)

    Moses, William W.; Qi, Jinyi

    2001-01-01

    We explore the causes of performance limitation in positron emission mammography cameras. We compare two basic camera geometries containing the same volume of 511 keV photon detectors, one with a parallel plane geometry and another with a rectangular geometry. We find that both geometries have similar performance for the phantom imaged (in Monte Carlo simulation), even though the solid angle coverage of the rectangular camera is about 50 percent higher than the parallel plane camera. The reconstruction algorithm used significantly affects the resulting image; iterative methods significantly outperform the commonly used focal plane tomography. Finally, the characteristics of the tumor itself, specifically the absolute amount of radiotracer taken up by the tumor, will significantly affect the imaging performance

  19. Applications of positron emission tomography to psychiatry

    International Nuclear Information System (INIS)

    Volkow, N.D.; Brodie, J.D.; Gomez-mont, F.

    1985-01-01

    The brain's inaccessibility has hampered investigation of the metabolic changes underlying the behavioral and psychological symptoms of psychiatric patients. Using positron emission transaxial tomography (PET) to study the functioning human brain opens the possibility of directly investigating the patterns of activity associated with mental illness. A major focus of present-day research in psychiatry has been to identify etiological agents that fit a medical model of psychiatric illness. Experiments seeking pathophysiological indices that would permit objective classification of psychiatric illnesses have failed to reveal consistent abnormalities. The lack of consistency is explained in part by research designs that deal with the brain as if it were a homogeneous organ. PET offers a unique technique for monitoring the regional biochemical activity that is associated with the different ''brain states'' and ''brain traits'' of normal subjects and psychiatric patients

  20. Fundamental limits of positron emission mammography

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W.; Qi, Jinyi

    2001-06-01

    We explore the causes of performance limitation in positron emission mammography cameras. We compare two basic camera geometries containing the same volume of 511 keV photon detectors, one with a parallel plane geometry and another with a rectangular geometry. We find that both geometries have similar performance for the phantom imaged (in Monte Carlo simulation), even though the solid angle coverage of the rectangular camera is about 50 percent higher than the parallel plane camera. The reconstruction algorithm used significantly affects the resulting image; iterative methods significantly outperform the commonly used focal plane tomography. Finally, the characteristics of the tumor itself, specifically the absolute amount of radiotracer taken up by the tumor, will significantly affect the imaging performance.

  1. Instrumentation optimization for positron emission mammography

    Energy Technology Data Exchange (ETDEWEB)

    Moses, William W.; Qi, Jinyi

    2003-06-05

    The past several years have seen designs for PET cameras optimized to image the breast, commonly known as Positron Emission Mammography or PEM cameras. The guiding principal behind PEM instrumentation is that a camera whose field of view is restricted to a single breast has higher performance and lower cost than a conventional PET camera. The most common geometry is a pair of parallel planes of detector modules, although geometries that encircle the breast have also been proposed. The ability of the detector modules to measure the depth of interaction (DOI) is also a relevant feature. This paper finds that while both the additional solid angle coverage afforded by encircling the breast and the decreased blurring afforded by the DOI measurement improve performance, the ability to measure DOI is more important than the ability to encircle the breast.

  2. Instrumentation optimization for positron emission mammography

    International Nuclear Information System (INIS)

    Moses, William W.; Qi, Jinyi

    2003-01-01

    The past several years have seen designs for PET cameras optimized to image the breast, commonly known as Positron Emission Mammography or PEM cameras. The guiding principal behind PEM instrumentation is that a camera whose field of view is restricted to a single breast has higher performance and lower cost than a conventional PET camera. The most common geometry is a pair of parallel planes of detector modules, although geometries that encircle the breast have also been proposed. The ability of the detector modules to measure the depth of interaction (DOI) is also a relevant feature. This paper finds that while both the additional solid angle coverage afforded by encircling the breast and the decreased blurring afforded by the DOI measurement improve performance, the ability to measure DOI is more important than the ability to encircle the breast

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

    International Nuclear Information System (INIS)

    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 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)

  4. Investigation of language lateralization mechanism by Positron Emission Tomography

    International Nuclear Information System (INIS)

    Belin, Pascal

    1997-01-01

    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 [fr

  5. Positron emission tomography in drug development and drug evaluation

    NARCIS (Netherlands)

    Paans, AMJ; Vaalburg, W

    2000-01-01

    Positron Emission Tomography (PET) is an imaging modality which can determine biochemical and physiological processes in vivo in a quantitative way by using radiopharmaceuticals labeled with positron emitting radionuclides as C-11, N-13, O-15 and F-18 and by measuring the annihilation radiation

  6. Integrated positron emission tomography/computed tomography for ...

    African Journals Online (AJOL)

    Integrated positron emission tomography/computed tomography for evaluation of mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosisendemic area: A 5-year prospective observational study.

  7. Positron emission tomography for the assessment of myocardial viability

    International Nuclear Information System (INIS)

    Schelbert, H.R.

    1991-01-01

    The detection of viable myocardium or ischemically injured myocardium with a reversible impairment of contractile function remains clinically important but challenging. Detection of reversible dysfunction and distinction from irreversible tissue injury by positron emission tomography is based on identification of preserved or even enhanced glucose metabolism with F-18 2-fluoro 2-deoxyglucose. Regional patterns of myocardial glucose utilization and blood flow, defined as perfusion-metabolism mismatches or matches, on positron emission tomography in patients with chronic or even acute ischemic heart disease are highly accurate in predicting the functional outcome after interventional revascularization. Compared with thallium-201 redistribution scintigraphy, positron emission tomography appears to be diagnostically more accurate, especially in patients with severely impaired left ventricular function. While larger clinical trials are needed for further confirmation, positron emission tomography has already proved clinically useful for stratifying patients with poor left ventricular function to the most appropriate therapeutic approach

  8. Positron emission tomography in patients with primary CNS lymphomas

    NARCIS (Netherlands)

    Roelcke, U; Leenders, KL

    This article reviews possible clinical applications of positron emission tomography (PET) in patients with CNS lymphomas. PET allows quantitative assessment of brain tumor pathophysiology and biochemistry in vivo. Therefore, it provides different information about tumors when compared to

  9. Functional cardiac imaging: positron emission tomography

    International Nuclear Information System (INIS)

    Mullani, N.A.; Gould, K.L.

    1984-01-01

    Dynamic cardiovascular imaging plays a vital role in the diagnosis and treatment of cardiac disease by providing information about the function of the heart. During the past 30 years, cardiovascular imaging has evolved from the simple chest x-ray and fluoroscopy to such sophisticated techniques as invasive cardiac angiography and cinearteriography and, more recently, to noninvasive cardiac CT scanning, nuclear magnetic resonance, and positron emission tomography, which reflect more complex physiologic functions. As research tools, CT, NMR, and PET provide quantitative information on global as well as regional ventricular function, coronary artery stenosis, myocardial perfusion, glucose and fatty acid metabolism, or oxygen utilization, with little discomfort or risk to the patient. As imaging modalities become more sophisticated and more oriented toward clinical application, the prospect of routinely obtaining such functional information about the heart is becoming realistic. However, these advances are double-edged in that the interpretation of functional data is more complex than that of the anatomic imaging familiar to most physicians. They will require an enhanced understanding of the physiologic and biochemical processes, as well as of the instrumentation and techniques for analyzing the data. Of the new imaging modalities that provide functional information about the heart, PET is the most useful because it quantitates the regional distribution of radionuclides in vivo. Clinical applications, interpretation of data, and the impact of PET on our understanding of cardiac pathophysiology are discussed. 5 figures

  10. Amorphous silicon detectors in positron emission tomography

    International Nuclear Information System (INIS)

    Conti, M.; Perez-Mendez, V.

    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 ε 2 τ'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. 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.

  12. Scatter correction for positron emission mammography

    International Nuclear Information System (INIS)

    Qi Jinyi; Huesman, Ronald H.

    2002-01-01

    In this paper we present a scatter correction method for a regularized list mode maximum likelihood reconstruction algorithm for the positron emission mammograph (PEM) that is being developed at our laboratory. The scatter events inside the object are modelled as additive Poisson random variables in the forward model of the reconstruction algorithm. The mean scatter sinogram is estimated using a Monte Carlo simulation program. With the assumption that the background activity is nearly uniform, the Monte Carlo scatter simulation only needs to run once for each PEM configuration. This saves computation time. The crystal scatters are modelled as a shift-invariant blurring in image domain because they are more localized. Thus, the useful information in the crystal scatters can be deconvolved in high-resolution reconstructions. The propagation of the noise from the estimated scatter sinogram into the reconstruction is analysed theoretically. The results provide an easy way to calculate the required number of events in the Monte Carlo scatter simulation for a given noise level in the image. The analysis is also applicable to other scatter estimation methods, provided that the covariance of the estimated scatter sinogram is available. (author)

  13. Scatter correction for positron emission mammography

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Jinyi; Huesman, Ronald H.

    2002-04-01

    In this paper we present a scatter correction method for a regularized list mode maximum likelihood reconstruction algorithm for the positron emission mammograph (PEM) that is being developed at our laboratory. The scatter events inside the object are modeled as additive Poisson random variables in the forward model of the reconstruction algorithm. The mean scatter sinogram is estimated using a Monte Carlo simulation program. With the assumption that the background activity is nearly uniform, the Monte Carlo scatter simulation only needs to run once for each PEM configuration. This saves computational time. The crystal scatters are modeled as a shift-invariant blurring in image domain because they are more localized. Thus, the useful information in the crystal scatters can be deconvolved in high-resolution reconstructions. The propagation of the noise from the estimated scatter sinogram into the reconstruction is analyzed theoretically. The results provide an easy way to calculate the required number of events in the Monte Carlo scatter simulation for a given noise level in the image. The analysis is also applicable to other scatter estimation methods, provided that the covariance of the estimated scatter sinogram is available.

  14. Image improvement method for positron emission mammography.

    Science.gov (United States)

    Slavine, Nikolai V; Seiler, Stephen J; McColl, Roderick W; Lenkinski, Robert E

    2017-07-01

    To evaluate in clinical use a rapidly converging, efficient iterative deconvolution algorithm (RSEMD) for improving the quantitative accuracy of previously reconstructed breast images by a commercial positron emission mammography (PEM) scanner. The RSEMD method was tested on imaging data from clinical Naviscan Flex Solo II PEM scanner. This method was applied to anthropomorphic like breast phantom data and patient breast images previously reconstructed with Naviscan software to determine improvements in image resolution, signal to noise ratio (SNR) and contrast to noise ratio (CNR). In all of the patients' breast studies the improved images proved to have higher resolution, contrast and lower noise as compared with images reconstructed by conventional methods. In general, the values of CNR reached a plateau at an average of 6 iterations with an average improvement factor of about 2 for post-reconstructed Flex Solo II PEM images. Improvements in image resolution after the application of RSEMD have also been demonstrated. A rapidly converging, iterative deconvolution algorithm with a resolution subsets-based approach (RSEMD) that operates on patient DICOM images has been used for quantitative improvement in breast imaging. The RSEMD method can be applied to PEM images to enhance the resolution and contrast in cancer diagnosis to monitor the tumor progression at the earliest stages. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  15. Radiologist views of positron emission mammography.

    Science.gov (United States)

    Greene, Lacey R; George, Robert F

    2012-01-01

    Early detection and diagnosis of malignant breast lesions are vital to survival. Although current imaging modalities such as mammography, ultrasonography, and magnetic resonance imaging focus on an anatomic approach, they do not provide sufficient data about the pathophysiology of malignant breast lesions. Positron emission mammography (PEM) is an innovative technology specifically designed to visualize the physiologic and metabolic processes in malignant breast lesions, but it remains underused as a diagnostic tool. The purpose of this research is to provide quantitative and qualitative evidence from radiologists' perspective about the efficacy of physiologic imaging and the future implementation of PEM as a diagnostic tool in clinical practice. Radiologists were asked to complete a survey designed to elicit their perspective on the role of physiologic imaging in detecting and diagnosing breast cancer and on PEM as an adjunct modality. Based on the survey data, 66% of participants considered physiologic imaging to be beneficial because it provides additional diagnostic data, and 67% supported the future use of PEM as an adjunct to mammography. Although preliminary indications favor the use of adjunct PEM, further research is needed before it becomes a common clinical tool.

  16. Positron emission mammography: initial clinical results.

    Science.gov (United States)

    Levine, Edward A; Freimanis, Rita I; Perrier, Nancy D; Morton, Kathryn; Lesko, Nadia M; Bergman, Simon; Geisinger, Kim R; Williams, Rodney C; Sharpe, Connie; Zavarzin, Valera; Weinberg, Irving N; Stepanov, Pavel Y; Beylin, David; Lauckner, Kathryn; Doss, Mohan; Lovelace, Judy; Adler, Lee P

    2003-01-01

    Evaluation of high-risk mammograms represents an enormous clinical challenge. Functional breast imaging coupled with mammography (positron emission mammography [PEM]) could improve imaging of such lesions. A prospective study was performed using PEM in women scheduled for stereotactic breast biopsy. Patients were recruited from the surgical clinic. Patients were injected with 10 mCi of 2-[18F] fluorodeoxyglucose. One hour later, patients were positioned on the stereotactic biopsy table, imaged with a PEM scanner, and a stereotactic biopsy was performed. Imaging was reviewed and compared with pathologic results. There were 18 lesions in 16 patients. PEM images were analyzed by drawing a region of interest at the biopsy site and comparing the count density in the region of interest with the background. A lesion-to-background ratio >2.5 appeared to be a robust indicator of malignancy and yielded a sensitivity of 86%, specificity of 91%, and overall diagnostic accuracy of 89%. No adverse events were associated with the PEM imaging. The data show that PEM is safe, feasible, and has an encouraging accuracy rate in this initial experience. Lesion-to-background ratios >2.5 were found to be a useful threshold value for identifying positive (malignant) results. This study supports the further development of PEM.

  17. Positron emission particle tracking in pulsatile flow

    Science.gov (United States)

    Patel, Nitant; Wiggins, Cody; Ruggles, Arthur

    2017-05-01

    Positron emission particle tracking (PEPT) is increasingly used to understand the flow characteristics in complex systems. This research utilizes PEPT to measure pulsatile flow of frequency 2.1 Hz in an elastic Masterkleer PVC tube of 19 mm inner diameter and 3.2 mm wall thickness. Anion exchange resin beads are labeled with 18F and delivered to a pump driven flow loop with motorized ball valve used to develop the pulsatile flow. Data are collected in the tube with circular cross section, and measurements are also collected with a section of the tube pinched. Nominal flow velocities are near 1 m/s and Reynolds numbers near 20,000. Many thousand PEPT particle traces are collected and synchronized with the flow pulsation. These Lagrangian data are presented as a series of 20 still frames depicting the 3-D velocity field present during each phase of the flow pulsation. Pressure data are also collected to resolve the pressure wave front moving through the open elastic tube at velocity 15.2 m/s.

  18. Simulation of the annihilation emission of galactic positrons

    International Nuclear Information System (INIS)

    Gillard, W.

    2008-01-01

    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)

  19. Positron Emission Mammography with Multiple Angle Acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    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.

  20. Positron Emission Mammography with Multiple Angle Acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FbG) 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.

  1. Shielding design for positron emission tomography facility

    International Nuclear Information System (INIS)

    Abdallah, I.I.

    2007-01-01

    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

  2. A new liquid xenon scintillation detector for positron emission tomography

    International Nuclear Information System (INIS)

    Chepel, V.Yu.

    1993-01-01

    A new positron-sensitive detector of annihilation photons filled with liquid xenon is proposed for positron emission tomography. Simultaneous detection of both liquid xenon scintillation and ionization current produces a time resolution of < 1 ns and a position resolution in the tangential direction of the tomograph ring is ∼ 1 mm and in the radial direction is ∼ 5 mm. The advantages of a tomograph with new detectors are discussed. New algorithms of Compton scattering can be used. (author)

  3. The Role of Positron Emission Tomography in Colorectal Carcinoma

    OpenAIRE

    Nachar, Oussama M.

    2002-01-01

    Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) is a functional imaging modality that provides mapping of glucose metabolism in the whole body. The glucose analogue fluorodeoxyglucose is labeled with the cyclotron-produced, positron-emitting radioisotope fluorine-18. The resulting radiopharmaceutical FDG is a substrate for glucose transport proteins (Glut) in cell membranes and accumulates intracellularly. Increased metabolic activity in malignant tissue is accompanied by...

  4. Positron emission tomographic imaging of tumors using monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Zalutsky, M.R.

    1992-08-01

    This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.

  5. Positron emission tomography scanning in malignant melanoma.

    Science.gov (United States)

    Tyler, D S; Onaitis, M; Kherani, A; Hata, A; Nicholson, E; Keogan, M; Fisher, S; Coleman, E; Seigler, H F

    2000-09-01

    Several recent studies have demonstrated the low yield of anatomically based computed tomography scans in evaluating Stage III (American Joint Committee on Cancer) patients with malignant melanoma. The purpose of this study was to investigate the efficacy and clinical utility of functionally based positron emission tomography (PET) scans in the same patient population. A prospective evaluation of 106 whole body PET scans obtained after injection of 2-fluorine-18, 2-fluoro-2-deoxy-D-glucose (FDG) was performed in 95 patients with clinically evident Stage III lymph node and/or in-transit melanoma. Areas of abnormality on FDG PET scanning were identified visually as foci of increased metabolic activity compared with background, and all positive foci were assessed pathologically. In this patient population, there were 234 areas that were evaluated pathologically of which 165 were confirmed histologically to be melanoma. PET scanning identified 144 of the 165 areas of melanoma for a sensitivity of 87.3%. The 21 areas of melanoma that were missed included 10 microscopic foci, 9 foci less than 1 cm, and 2 foci greater than 1 cm. There were 39 areas of increased PET activity that were not associated with malignancy for a 78.6% predictive value of a positive test. Of the 39 false-positive areas (false-positive rate of 56.5%), 13 could be attributed to recent surgery, 3 to arthritis, 3 to infection, 2 to superficial phlebitis, 1 to a benign skin nevus, and 1 to a colonic polyp. Pathologic evaluation of the remaining false-positive areas failed to reveal a definitive etiology for their increased activity on PET scan. With the application of pertinent clinical information, the predictive value of a positive PET scan could be improved to 90. 6%. The specificity of PET scanning in this study was only 43.5% because very few prophylactic lymph node dissections were performed. Thirty-six of the total 183 abnormal areas (19.7%) on PET scanning proved to be unsuspected areas of

  6. Positron emission mammography-guided breast biopsy.

    Science.gov (United States)

    Raylman, R R; Majewski, S; Weisenberger, A G; Popov, V; Wojcik, R; Kross, B; Schreiman, J S; Bishop, H A

    2001-06-01

    Positron emission mammography (PEM) is a technique to obtain planar images of the breast for detection of potentially cancerous, radiotracer-avid tumors. To increase the diagnostic accuracy of this method, use of minimally invasive methods (e.g., core biopsy) may be desirable for obtaining tissue samples from lesions detected with PEM. The purpose of this study was to test the capabilities of a novel method for performing PEM-guided stereotactic breast biopsies. The PEM system consisted of 2 square (10 x 10 cm) arrays of discrete scintillator crystals. The detectors were mounted on a stereotactic biopsy table. The stereotactic technique used 2 PEM images acquired at +/-15 degrees and a new trigonometric algorithm. The accuracy and precision of the guidance method was tested by placement of small point sources of (18)F at known locations within the field of view of the imager. The calculated positions of the sources were compared with the known locations. In addition, simulated stereotactic biopsies of a breast phantom consisting of a 10-mm-diameter gelatin sphere containing a concentration of (18)F-FDG consistent with that reported for breast cancer were performed. The simulated lesion was embedded in a 4-cm-thick slab of gelatin containing a commonly reported concentration of FDG, simulating a compressed breast (target-to-background ratio, approximately 8.5:1). An anthropomorphic torso phantom was used to simulate tracer uptake in the organs of a patient 1 h after a 370-MBq injection of FDG. Five trials of the biopsy procedure were performed to assess repeatability. Finally, a method for verifying needle positioning was tested. The positions of the point sources were successfully calculated to within 0.6 mm of their true positions with a mean error of +/-0.4 mm. The biopsy procedures, including the method for verification of needle position, were successful in all 5 trials in acquiring samples from the simulated lesions. The success of this new technique shows its

  7. Redistribution of myocardial perfusion during permanent dual chamber pacing in symptomatic non-obstructive hypertrophic cardiomyopathy : A quantitative positron emission tomography study

    NARCIS (Netherlands)

    Posma, JL; Blanksma, PK; vanderWall, EE

    Dual chamber pacing causes significant symptomatic improvement in many patients with hypertrophic cardiomyopathy. The mechanism behind this beneficial response is not fully understood. Positron emission tomography showed a redistribution of myocardial flow during pacing in a patient with

  8. Positron emission tomography : measurement of transgene expression

    NARCIS (Netherlands)

    de Vries, EFJ; Vaalburg, W

    Noninvasive and repetitive imaging of transgene expression can play a pivotal role in the development of gene therapy strategies, as it offers investigators a means to determine the effectiveness of their gene transfection protocols. In the last decade, imaging of transgene expression using positron

  9. New detector developments for high resolution positron emission tomography

    International Nuclear Information System (INIS)

    Ziegler, S.I.; Pichler, B.; Lorenz, E.

    1998-01-01

    The strength of quantitative, functional imaging using positron emission tomography, specially in small animals, is limited due to the spatial resolution. Therefore, various tomograph designs employing new scintillators, light sensors, or coincidence electronic are investigated to improve resolution without losses in sensitivity. Luminous scintillators with short light decay time in combination with novel readout schemes using photomultipliers or semiconductor detectors are currently tested by several groups and are implemented in tomographs for small animals. This review summarises the state of development in high resolution positron emission tomography with a detailed description of a system incorporating avalanche photodiode arrays and small scintillation crystals. (orig.) [de

  10. Positron emission tomography in oncology. Council on Scientific Affairs

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This report describes the current and potential uses of positron emission tomography in clinical medicine and research related to oncology. Assessment will be possible of metabolism and physiology of tumors and their effects on adjacent tissues. Specific probes are likely to be developed for target sites on tumors, including monoclonal antibodies and specific growth factors that recognize tumors. To date, most oncological applications of positron emission tomography tracers have been qualitative; in the future, quantitative metabolic measurements should aid in the evaluation of tumor biology and response to treatment. 41 references

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

    International Nuclear Information System (INIS)

    Bauer, R.

    1994-01-01

    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.) [de

  12. 3D fast reconstruction in positron emission tomography

    International Nuclear Information System (INIS)

    Egger, M.L.; Scheurer, A. Hermann; Joseph, C.; Morel, C.

    1996-01-01

    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

  13. Detectors, sampling, shielding, and electronics for positron emission tomography

    International Nuclear Information System (INIS)

    Derenzo, S.E.

    1981-08-01

    A brief discussion of the important design elements for positron emission tomographs is presented. The conclusions are that the instrumentation can be improved by the use of larger numbers of small, efficient detectors closely packed in many rings, the development of new detector materials, and novel electronic designs to reduce the deadtime and increase maximum event rates

  14. Positron Emission Tomography : background, possibilities and perspectives in neuroscience

    NARCIS (Netherlands)

    Paans, AMJ

    Positron Emission Tomography (PET) is a method for determining biochemical and physiological processes in vivo in a quantitative way. This includes the measurement of the pharmacokinetics of labeled drugs and the measurement of the effects of drugs and/or therapy on metabolism. Also deviations of

  15. Positron emission tomography of incidentally detected small pulmonary nodules

    DEFF Research Database (Denmark)

    Fischer, B M; Mortensen, J; Dirksen, A

    2004-01-01

    The aim of this study was to assess the value of fluorodeoxyglucose positron emission tomography (FDG PET) imaging of small pulmonary nodules incidentally detected by spiral computed tomography (CT) in a high-risk population. Ten patients (five females, five males, aged 54-72 years) were recruited...

  16. Amyloid-β positron emission tomography imaging probes

    DEFF Research Database (Denmark)

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

    2013-01-01

    , a 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...

  17. 64Cu loaded liposomes as positron emission tomography imaging agents

    DEFF Research Database (Denmark)

    Petersen, Anncatrine Luisa; Binderup, Tina; Rasmussen, Palle

    2011-01-01

    We have developed a highly efficient method for utilizing liposomes as imaging agents for positron emission tomography (PET) giving high resolution images and allowing direct quantification of tissue distribution and blood clearance. Our approach is based on remote loading of a copper...

  18. Quantification in dynamic and small-animal positron emission tomography

    NARCIS (Netherlands)

    Disselhorst, Johannes Antonius

    2011-01-01

    This thesis covers two aspects of positron emission tomography (PET) quantification. The first section addresses the characterization and optimization of a small-animal PET/CT scanner. The sensitivity and resolution as well as various parameters affecting image quality (reconstruction settings, type

  19. Sentence comprehension and word repetition : A positron emission tomography investigation

    NARCIS (Netherlands)

    Stowe, L.A.; Paans, A.M.J.; Wijers, A.A.; Zwarts, F.; Mulder, G.; Vaalburg, W.

    1999-01-01

    Using positron emission tomography, visual presentation of sentences was shown to cause increased regional cerebral blood flow relative to word Lists in the left lateral anterior superior and middle temporal gyri, attributable to cognitive processes that occur during sentence comprehension in

  20. Positron emission tomography for staging of oesophageal and gastroesophageal malignancy

    NARCIS (Netherlands)

    Kole, AC; Plukker, JT; Nieweg, OE; Vaalburg, W

    Positron emission tomography (PET) with [F-18]-fluoro-2-deoxy-D-glucose (FDG) was prospectively investigated as a means of detecting metastatic disease in patients with oesophageal tumours and compared with computerized tomography (CT), with the surgical findings as a gold standard. Twenty-six

  1. Measurement of absolute bone blood flow by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nahmias, C.; Cockshott, W.P.; Garnett, E.S.; Belbeck, L.W.

    1986-03-01

    A method of measuring bone blood flow has been developed using /sup 18/F sodium fluoride and positron emission tomography. The blood flow levels are in line with those obtained experimentally from microsphere embolisation. This investigative method could be applied to elucidate a number of clinical questions involving bone perfusion.

  2. 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

  3. Positron emission tomography/computed tomography scanning for ...

    African Journals Online (AJOL)

    Background: Although the site of nosocomial sepsis in the critically ill ventilated patient is usually identifiable, it may remain occult, despite numerous investigations. The rapid results and precise anatomical location of the septic source using positron emission tomography (PET) scanning, in combination with computed ...

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

    International Nuclear Information System (INIS)

    Steinling, M.; Samson, Y.

    1999-01-01

    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.)

  5. Serotonin synthesis studied with positron emission tomography, (PET)

    DEFF Research Database (Denmark)

    Honoré, Per Gustaf Hartvig; Lundquist, Pinelopi

    Positron emission tomography (PET) has the potential to study the biosynthesis and release of serotonin (5HT) at brain serotonergic neurons. PET requires probe compounds with specific attributes to enable imaging and quantification of biological processes. This section focuses on probes to measure...

  6. Fluorinated amino acids for tumour imaging with positron emission tomography.

    NARCIS (Netherlands)

    Laverman, P.; Boerman, O.C.; Corstens, F.H.M.; Oyen, W.J.G.

    2002-01-01

    The currently preferred radiopharmaceutical for positron emission tomography (PET) in oncology is 2-[(18)F]fluoro-deoxyglucose (FDG). Increased accumulation of this deoxyglucose analogue in tumour cells is based on elevated glucose metabolism by tumour cells and subsequent trapping in the cells. In

  7. 77 FR 71802 - Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    Science.gov (United States)

    2012-12-04

    ...] Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs; Availability... Positron Emission Tomography (PET) Drugs.'' The guidance is intended to assist manufacturers of PET drugs... ``Investigational New Drug Applications for Positron Emission Tomography (PET) Drugs.'' The guidance summarizes the...

  8. 77 FR 21783 - Guidance on Media Fills for Validation of Aseptic Preparations for Positron Emission Tomography...

    Science.gov (United States)

    2012-04-11

    ...] Guidance on Media Fills for Validation of Aseptic Preparations for Positron Emission Tomography Drugs... Aseptic Preparations for Positron Emission Tomography (PET) Drugs.'' This guidance is intended to help... Preparations for Positron Emission Tomography (PET) Drugs.'' Most PET drugs are designed for parenteral...

  9. Images to visualize the brain. PET: Positron Emission Tomography

    International Nuclear Information System (INIS)

    1992-01-01

    Diagnosis instrument and research tool, Positron Emission Tomography permits advanced technological developments on positron camera, on molecule labelling and principally on very complex 3D image processing. Cyceron Centre in Caen-France works on brain diseases and try to understand the mechanism of observed troubles and to assess the treatment efficiency with PET. Service Hospitalier Frederic Joliot of CEA-France establishes a mapping of cognitive functions in PET as vision areas, anxiety regions, brain organization of language, different attention forms, voluntary actions and motor functions

  10. Positron emission tomography in a national research centre

    International Nuclear Information System (INIS)

    Weinreich, R.

    1989-01-01

    The example of the Paul Scherrer Institute shows that positron emission tomography can be implanted successfully as spin-off into an appropriate environment. The adaption to the existing irradiation facilities of the technique of production of the short-lived positron emitters is complex. However, the basic necessities of a tomography programme can be covered. Moreover, the relatively high energy of the institute's injector cyclotron allows additional production of rare-used longer-lived positron emitters. The scanner exceeded the guaranteed specifications. With respect to the somewhat lower availability of beam time compared to a usual baby cyclotron, the research programme must not be very patient-intense. A strong participation of the pharmaceutical industry has directed research priorities into the pharmacological area. (orig.) [de

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

    International Nuclear Information System (INIS)

    Paez Gutierrez, Diana Isabel; De los Reyes, Amelia; Llamas Olier, Augusto

    2007-01-01

    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

  12. Alcohol ADME in primates studied with positron emission tomography.

    Directory of Open Access Journals (Sweden)

    Zizhong Li

    Full Text Available The sensitivity to the intoxicating effects of alcohol as well as its adverse medical consequences differ markedly among individuals, which reflects in part differences in alcohol's absorption, distribution, metabolism, and elimination (ADME properties. The ADME of alcohol in the body and its relationship with alcohol's brain bioavailability, however, is not well understood.The ADME of C-11 labeled alcohol, CH(3 (11CH(2OH, 1 and C-11 and deuterium dual labeled alcohol, CH(3 (11CD(2OH, 2 in baboons was compared based on the principle that C-D bond is stronger than C-H bond, thus the reaction is slower if C-D bond breaking occurs in a rate-determining metabolic step. The following ADME parameters in peripheral organs and brain were derived from time activity curve (TAC of positron emission tomography (PET scans: peak uptake (C(max; peak uptake time (T(max, half-life of peak uptake (T(1/2, the area under the curve (AUC(60 min, and the residue uptake (C(60 min.For 1 the highest uptake occurred in the kidney whereas for 2 it occurred in the liver. A deuterium isotope effect was observed in the kidneys in both animals studied and in the liver of one animal but not the other. The highest uptake for 1 and 2 in the brain was in striatum and cerebellum but 2 had higher uptake than 1 in all brain regions most evidently in thalamus and cingulate. Alcohol's brain uptake was significantly higher when given intravenously than when given orally and also when the animal was pretreated with a pharmacological dose of alcohol.The study shows that alcohol metabolism in peripheral organs had a large effect on alcohol's brain bioavailability. This study sets the stage for clinical investigation on how genetics, gender and alcohol abuse affect alcohol's ADME and its relationship to intoxication and medical consequences.

  13. Nuclear medicine and positron emission tomography: An overview

    International Nuclear Information System (INIS)

    McCarthy, T.J.; Schwarz, S.W.; Welch, M.J.

    1994-01-01

    Nuclear medicine is the field of medical practice that involves the oral or intravenous administration of radioactive materials for use in diagnosis and therapy. The majority of radiopharmaceutical available are used for diagnostic purposes. These involve the determination of organ function, shape, or position from an image of the radioactivity distribution within an organ or at a location within the body. After administration, the radiopharmaceutical localizes within an organ or target tissue due to its biological or physiologic characteristics. This diagnostic capability is usually the result of the emission of gamma radiation from the radiopharmaceutical localized within an organ. This allows for external detection and imaging using a special type of camera known as a gamma camera. When a positron-emitting radionuclide decays, a positron (positive electron) is emitted from the nucleus. The positron then annihilates with an electron, resulting in the release of energy in the form of two 511-KeV γ-rays at 180 degree to one another. The energy of these photons is sufficient to pass through tissue. Thus, placing a series of detectors around the patient allows technicians to monitor the emission of both of the photons that result from a single positron annihilation. this ultimately allows an accurate quantification of the distribution of radioactivity in the body not possible when only a single γ-ray is emitted

  14. Clinical applications of positron emission tomography at Montreal Neurological Institute

    International Nuclear Information System (INIS)

    Morgan, P.P.

    1983-01-01

    The Montreal Neurological Institute occupies a leading position in positron emission tomography (PET) of the brain with the help of the following three techological gains: they have acquired a 'Therascan' positron emission tomograph manufactured by Atomic Energy of Canada Ltd.; also, a 'Baby Cyclotron' manufactured by Japan Steel Works Ltd.; and they have written a computer program to display the results in colour. Four short-lived isotopes are used; 11 C, 15 O, 18 F, 13 N. Studies of the oxygen uptake of tumours, their glucose metabolism (as monitored by 18 F labelled 2-fluoro-2-deoxyglucose), and their uptake of therapeutic agents, provide valuable research and diagnostic information. PET is also being used to study epilepsy and cerebrovascular disease

  15. Measurement of brain pH with positron emission tomography

    International Nuclear Information System (INIS)

    Buxton, R.B.; Alpert, N.M.; Ackerman, R.H.; Wechsler, L.R.; Elmaleh, D.R.; Correia, J.A.

    1985-01-01

    With positron emission tomography (PET) it is now possible to measure local brain pH noninvasively in humans. The application of PET to the determination of pH is relatively new, so only a handful of papers on the subject have appeared in print. This chapter reviews the current strategies for measuring brain pH with PET, discuss methodological problems, and present initial results

  16. Detectors for high resolution dynamic positron emission tomography

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.

    1985-01-01

    Tomography is the technique of producing a photographic image of an opaque specimen by transmitting a beam of x-rays or gamma rays through the specimen onto an adjacent photographic film. The image results from variations in thickness, density, and chemical composition, of the specimen. This technique is used to study the metabolism of the human brain. This article examines the design of equipment used for high resolution dynamic positron emission tomography. 27 references, 5 figures, 3 tables

  17. Simulated annealing image reconstruction for positron emission tomography

    International Nuclear Information System (INIS)

    Sundermann, E.; Lemahieu, I.; Desmedt, P.

    1994-01-01

    In Positron Emission Tomography (PET) images have to be reconstructed from moisy projection data. The noise on the PET data can be modeled by a Poison distribution. In this paper, we present the results of using the simulated annealing technique to reconstruct PET images. Various parameter settings of the simulated annealing algorithm are discussed and optimized. The reconstructed images are of good quality and high contrast, in comparison to other reconstruction techniques. (authors)

  18. Comparison of Diagnostic Performance of Three-Dimensional Positron Emission Mammography versus Whole Body Positron Emission Tomography in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Dong Dai

    2017-01-01

    Full Text Available Objective. To compare the diagnostic performance of three-dimensional (3D positron emission mammography (PEM versus whole body positron emission tomography (WBPET for breast cancer. Methods. A total of 410 women with normal breast or benign or highly suspicious malignant tumors were randomized at 1 : 1 ratio to undergo 3D-PEM followed by WBPET or WBPET followed by 3D-PEM. Lumpectomy or mastectomy was performed on eligible participants after the scanning. Results. The sensitivity and specificity of 3D-PEM were 92.8% and 54.5%, respectively. WBPET showed a sensitivity of 95.7% and specificity of 56.8%. After exclusion of the patients with lesions beyond the detecting range of the 3D-PEM instrument, 3D-PEM showed higher sensitivity than WBPET (97.0% versus 95.5%, P = 0.913, particularly for small lesions (<1 cm (72.0% versus 60.0%, P = 0.685. Conclusions. The 3D-PEM appears more sensitive to small lesions than WBPET but may fail to detect lesions that are beyond the detecting range. This study was approved by the Ethics Committee (E2012052 at the Tianjin Medical University Cancer Institute and Hospital (Tianjin, China. The instrument positron emission mammography (PEMi was approved by China State Food and Drug Administration under the registration number 20153331166.

  19. Comparison of Diagnostic Performance of Three-Dimensional Positron Emission Mammography versus Whole Body Positron Emission Tomography in Breast Cancer.

    Science.gov (United States)

    Dai, Dong; Song, Xiuyu; Wang, Man; Li, Lin; Ma, Wenchao; Xu, Wengui; Ma, Yunchuan; Liu, Juntian; Zhang, Jin; Liu, Peifang; Gu, Xiaoyue; Su, Yusheng

    2017-01-01

    To compare the diagnostic performance of three-dimensional (3D) positron emission mammography (PEM) versus whole body positron emission tomography (WBPET) for breast cancer. A total of 410 women with normal breast or benign or highly suspicious malignant tumors were randomized at 1 : 1 ratio to undergo 3D-PEM followed by WBPET or WBPET followed by 3D-PEM. Lumpectomy or mastectomy was performed on eligible participants after the scanning. The sensitivity and specificity of 3D-PEM were 92.8% and 54.5%, respectively. WBPET showed a sensitivity of 95.7% and specificity of 56.8%. After exclusion of the patients with lesions beyond the detecting range of the 3D-PEM instrument, 3D-PEM showed higher sensitivity than WBPET (97.0% versus 95.5%, P = 0.913), particularly for small lesions (PEM appears more sensitive to small lesions than WBPET but may fail to detect lesions that are beyond the detecting range. This study was approved by the Ethics Committee (E2012052) at the Tianjin Medical University Cancer Institute and Hospital (Tianjin, China). The instrument positron emission mammography (PEMi) was approved by China State Food and Drug Administration under the registration number 20153331166.

  20. Positron transaxial emission tomograph with computerized image reconstruction

    International Nuclear Information System (INIS)

    Jatteau, Michel.

    1981-01-01

    This invention concerns a positron transaxial emission tomography apparatus with computerized image reconstruction, like those used in nuclear medicine for studying the metabolism of organs, in physiological examinations and as a diagnosis aid. The operation is based on the principle of the detection of photons emitted when the positrons are annihilated by impact with an electron. The appliance is mainly composed of: (a) - a set of gamma ray detectors distributed on a polygonal arrangement around the body area to be examined, (b) - circuits for amplifying the signals delivered by the gamma ray detectors, (c) - computers essentially comprising energy integration and discrimination circuits and provided at the output of the detectors for calculating and delivering, as from the amplified signals, information on the position and energy relative to each occurrence constituted by the detections of photons, (d) - time coincidence circuits for selecting by emission of detector validation signals, only those occurrences, among the ensemble of those detected, which effectively result from the annihilation of positrons inside the area examined, (e) - a data processing system [fr

  1. Positron emission tomography and cerebral metabolism

    International Nuclear Information System (INIS)

    Comar, D.; Maziere, M.; Zarifian, E.; Naquet, R.

    1979-01-01

    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- 11 C 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- 11 C 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 11 C-flunitrazepam (specific activity = 600 Ci/μmole) and subsequent displacement of this radioactive ligand by a pharmacological dose of Lorazepam

  2. An automated blood sampling system used in positron emission tomography

    International Nuclear Information System (INIS)

    Eriksson, L.; Bohm, C.; Kesselberg, M.

    1988-01-01

    Fast dynamic function studies with positron emission tomography (PET), has the potential to give accurate information of physiological functions of the brain. This capability can be realised if the positron camera system accurately quantitates the tracer uptake in the brain with sufficiently high efficiency and in sufficiently short time intervals. However, in addition, the tracer concentration in blood, as a function of time, must be accurately determined. This paper describes and evaluates an automated blood sampling system. Two different detector units are compared. The use of the automated blood sampling system is demonstrated in studies of cerebral blood flow, in studies of the blood-brain barrier transfer of amino acids and of the cerebral oxygen consumption. 5 refs.; 7 figs

  3. 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.

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

    Science.gov (United States)

    Lavayssière, Robert; Cabée, Anne-Elizabeth; Filmont, Jean-Emmanuel

    2009-01-01

    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 [Juweid ME, Cheson BD. Positron-emission tomography and assessment of cancer therapy. N Engl J Med 2006;354:496-507; Koh DM, Cook GJR, Husband JE. New horizons in oncologic imaging. N Engl J Med 2003;348:25; Tafra L, positron emission tomography (PET) and mammography (PEM) for breast cancer: importance to surgeons. Ann Surg Oncol 2006;14(1):3-13] 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

  5. The metabolism of the human brain studied with positron emission tomography

    International Nuclear Information System (INIS)

    Greitz, T.; Ingvar, D.H.; Widen, L.

    1985-01-01

    This volume presents coverage of the use of positron emission tomography (PET) to study the human brain. The contributors assess new developments in high-resolution positron emission tomography, cyclotrons, radiochemistry, and tracer kinetic models, and explore the use of PET in brain energy metabolism, blood flow, and protein synthesis measurements, receptor analysis, and pH determinations, In addition, they discuss the relevance and applications of positron emission tomography from the perspectives of physiology, neurology, and psychiatry

  6. Positron emission tomography findings in atypical polypoid adenomyoma

    Directory of Open Access Journals (Sweden)

    Tatsuya Fukami

    2016-03-01

    Full Text Available Atypical polypoid adenomyoma (APAM is a rare polypoid tumor of the uterus composed of atypical endometrial glands surrounded by smooth muscle. A 29-year-old nulligravida, was clinically diagnosed with endocervical myoma and underwent trans-uterine cervical resection with hysteroscope. The histopathological diagnosis of specimens was APAM. Eight months later, she diagnosed recurrent uterine tumor. The positron emission tomography (PET-CT imaging showed an increased fluorodeoxyglucose uptake. She has performed hysterectomy and was diagnosed APAM. Therapy for APAM depends on multiple factors such as age at presentation and desire for childbearing among others. This is the first report of PET-CT findings in APAM.

  7. A Real Time Digital Coincidence Processor for positron emission tomography

    International Nuclear Information System (INIS)

    Dent, H.M.; Jones, W.F.; Casey, M.E.

    1986-01-01

    A Real Time Digital Coincidence Processor has been developed for use in the Positron Emission Tomograph (PET) ECAT scanners manufactured by Computer Technology and Imaging, Inc. (CTI). The primary functions of the Coincidence Processor include: receive from the BGO detector modules serial data, which includes timing information and detector identification; process the received data to form coincidence detector pairs; and present the coincidence pair data to a Real Time Sorter. The primary design emphasis was placed on the Coincidence Processor being able to process the detector data into coincidence pairs at real time rates. This paper briefly describes the Coincidence Processor and some of the considerations that went into its design

  8. Low-resource synchronous coincidence processor for positron emission tomography

    International Nuclear Information System (INIS)

    Sportelli, Giancarlo; Belcari, Nicola; Guerra, Pedro; Santos, Andres

    2011-01-01

    We developed a new FPGA-based method for coincidence detection in positron emission tomography. The method requires low device resources and no specific peripherals in order to resolve coincident digital pulses within a time window of a few nanoseconds. This method has been validated with a low-end Xilinx Spartan-3E and provided coincidence resolutions lower than 6 ns. This resolution depends directly on the signal propagation properties of the target device and the maximum available clock frequency, therefore it is expected to improve considerably on higher-end FPGAs.

  9. Time-of-Flight Positron Emission Tomography with Radiofrequency Phototube

    International Nuclear Information System (INIS)

    Margaryan, A.; Kakoyan, V.; Knyazyan, S.

    2011-01-01

    In this paper γ-detector, based on the radiofrequency (RF) phototube and recently developed fast and ultrafast scintillators, is considered for Time-of-Flight positron emission tomography applications. Timing characteristics of such a device has been investigated by means of a dedicated Monte Carlo code based on the single photon counting concept. Biexponential timing model for scintillators have been used. The calculations have shown that such a timing model is in a good agreement with recently measured data. The timing resolution of -detectors can be significantly improved by using the RF phototube. (authors)

  10. Application of positron emission tomography in industrial research

    International Nuclear Information System (INIS)

    Jonkers, G.; van den Bergen, E.A.; Vonkeman, K.A.

    1990-01-01

    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 66 Ga-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 68 Ga-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 11 C (t1/2 = 20 min), 13 N (t1/2 = 10 min) and 15 0 (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 11 C-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)

  11. Clinical applications of positron emission tomography in breast cancer patients

    International Nuclear Information System (INIS)

    Roemer, W.; Avril, N.; Schwaiger, M.

    1997-01-01

    Increased glucose metabolism by malignant tissue can be visualized with positron emission tomography (PET), using the radiolabeled glucose analogue F-18 fluorodeoxyglucose (FDG). Depending on the criteria of image interpretation FDG-PET allows detection of breast cancer with a sensitivity of 68% to 94 % and a specificity of 84 % to 97 %. However, sensitivity to visualize small tumors (< 1 cm) is limited. Positron emission tomography demonstrates tumor involvement of regional lymph nodes with high accuracy, predominantly in patients with advanced breast cancer. The sensitivity for the detection of axillary lymph node metastases was 79% with a corresponding specificity of 96 %. Lymph node metastases could not be identified in four of six patients with small primary breast cancer (stage pT1), resulting in a sensitivity of only 33% in these patients. By visualizing primary tumors and metastases in one imaging procedure, PET imaging may allow the effective staging of breast cancer patients. Further studies are needed to define the role of scintigraphic techniques for the diagnostic work-up in patients. (author)

  12. Positron emission tomography in the management of cervix cancer patients

    International Nuclear Information System (INIS)

    Bonardel, G.; Gontier, E.; Soret, M.; Dechaud, C.; Fayolle, M.; Foehrenbach, H.; Chargari, C.; Bauduceau, O.

    2009-01-01

    Since its introduction in clinical practice in the 1990 s, positron emission tomography (PET), usually with 18 F-fluoro-2-deoxy-D-glucose ( 18 F-F.D.G.), has become an important imaging modality in patients with cancer. For cervix carcinoma, F.D.G.-PET is significantly more accurate than computed tomography (CT) and is recommended for loco-regional lymph node and extra pelvic staging. The metabolic dimension of the technique provides additional prognostic information. Ongoing studies now concentrate on more advanced clinical applications, such as the planning of radiotherapy, the response evaluation after the induction of therapy, the early detection of recurrence. Technical innovations, such as PET cameras with better spatial resolution and hybrid positron emission tomography/computed tomography (PET-CT), available now on the whole territory, provide both anatomic and metabolic information in the same procedure. From the point of view of biological metabolism, new radiopharmaceutical probes are being developed. Those hold promise for future refinements in this field. This article reviews the current applications of F.D.G.-PET in patients with cervix cancer. (authors)

  13. Positron emission CT on post-traumatic epilepsy

    International Nuclear Information System (INIS)

    Tsukiyama, Takashi; Tsubokawa, Takashi; Doi, Nobuyasu; Sato, Kohten; Iio, Masaaki.

    1983-01-01

    Six patients suffering from post-traumatic epilepsy were checked by encephalography (EEG), X-ray CT and cerebral positron emission computed tomography (PECT) using 11 C-carbon dioxide ( 11 CO 2 ) and 11 C-glucoses as indicators of the local cerebral circulation and local cerebral glucose utilization, in order to assess the diagnostic value of PECT in post-traumatic epilepsy. In those patients (4 cases) who had focal electrical abnormalities or X-ray CT lesions, PECT clearly revealed localized regions of decreased cerebral circulation and glucose utilization. A focal hypometabolic zone also appeared in the post-traumatic epilepsy (1 case) which had a normal X-ray CT. One case, who had been treated for several years by medication but showed no EEG change and no abnormality on X-ray CT, revealed a normal circulation and metabolism by RECT. This case did not require any further medication for epilepsy. It is concluded that positron emission CT represents a useful diagnostic method for post-traumatic epilepsy which does not demonstrate any abnormality on X-ray CT. (author)

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

    International Nuclear Information System (INIS)

    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. (author)

  15. 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)

  16. 76 FR 6144 - Positron Emission Tomography; Notice of Public Meeting; Request for Comments

    Science.gov (United States)

    2011-02-03

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-N-0060] Positron Emission Tomography; Notice of Public Meeting; Request for Comments AGENCY: Food and Drug... injection, and sodium fluoride F 18 injection used in positron emission tomography (PET) imaging. By...

  17. 4.5 Tesla magnetic field reduces range of high-energy positrons -- Potential implications for positron emission tomography

    International Nuclear Information System (INIS)

    Wirrwar, A.; Vosberg, H.; Herzog, H.; Halling, H.; Weber, S.; Mueller-Gaertner, H.W.; Forschungszentrum Juelich GmbH

    1997-01-01

    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

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

    International Nuclear Information System (INIS)

    Lavayssiere, Robert; Cabee, Anne-Elizabeth; Filmont, Jean-Emmanuel

    2009-01-01

    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

  19. 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].

  20. Evaluation of scintillators and semiconductor detectors to image three-photon positron annihilation for positron emission tomography

    International Nuclear Information System (INIS)

    Abuelhia, E.; Spyrou, N.M.; Kacperski, K.; College University, Middlesex Hospital, London

    2008-01-01

    Positron emission tomography (PET) is rapidly becoming the main nuclear imaging modality of the present century. The future of PET instrumentation relies on semiconductor detectors because of their excellent characteristics. Three-photon positron annihilation has been recently investigated as a novel imaging modality, which demands the crucial high energy resolution of semiconductor detector. In this work the evaluation of the NaI(Tl) scintillator and HPGe and CdZTe semiconductor detectors, to construct a simple three-photon positron annihilation scanner has been explored. The effect of detector and scanner size on spatial resolution (FWHM) is discussed. The characteristics: energy resolution versus count rate and point-spread function of the three-photon positron annihilation image profile from triple coincidence measurements were investigated. (author)

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

    International Nuclear Information System (INIS)

    Buck, A.; Kamel, E.

    2002-01-01

    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)

  2. Application of positron emission tomography in the lung

    International Nuclear Information System (INIS)

    Valind, S.O.; Wollmer, P.E.; Rhodes, C.G.

    1985-01-01

    The early application of positron emission tomography in the lung was mainly concerned with the investigation of the regional volume of the vascular and extravascular compartments, using measurements of fractional blood volume and lung density. However, in addition to its passive role in the exchange of oxygen and carbon dioxide, the lung exerts a number of active, metabolic functions such as the inactivation of circulating vasoactive compounds and the synthesis and release of biologically active substances. Furthermore, many of the pulmonary disorders originate at a cellular or metabolic level, or have metabolic consequences. Many of the substrates of biochemical reactions and the biologically active compounds, or their analogs, can be labeled with positron-emitting radioisotopes without disturbing their biological or biochemical characteristics. In combination with the development of the appropriate physiological and biochemical models, the quantitative measurements possible with PET provide a unique opportunity of regionally studying the metabolic processes of the lung of man in vivo. Hence, a range of different expressions of metabolism and of lung function can be evaluated and their interdependence can be studied regionally

  3. Positron Emission Tomography Application to Drug Development and Research

    Science.gov (United States)

    Salvadori, Piero A.

    The research for the identification and development of new drugs represents a very complex process implying long times and massive investments. This process was not able to parallel the rate of discoveries made in the field of genomic and molecular biology and a gap created between demand of new drugs and the ability of pharmaceutical companies to select good candidates. Positron Emission Tomography, among the different Molecular Imaging modalities, could represent a new tool for the early assessment and screening of new drug candidates and, due to its physical performances and the characteristics of positron-labeled tracers, gain the role of "Biomarker" accepted by the Companies and the Regulatory Bodies of Drug Agencies. To fulfil this task PET has to exploit all of its special features such as data absolute quantification and modelling, high spatial resolution and dynamic imaging. Relevant efforts need to be directed to the careful design and validation of experimental protocols with the main goal of achieving consistency in multi- centric trials.

  4. Temporoparietal cortex in aphasia. Evidence from positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Metter, E.J.; Hanson, W.R.; Jackson, C.A.; Kempler, D.; van Lancker, D.; Mazziotta, J.C.; Phelps, M.E. (National Institute of Aging, Baltimore, MD (USA))

    1990-11-01

    Forty-four aphasic patients were examined with (F18)-fluorodeoxyglucose positron emission tomography in a resting state to determine whether consistent glucose metabolic abnormalities were present. Ninety-seven percent of subjects showed metabolic abnormalities in the angular gyrus, 89% in the supramarginal gyrus, and 87% in the lateral and transverse superior temporal gyrus. Pearson product moment correlations were calculated between regional metabolic measures and performance on the Western Aphasia Battery. No significant correlations were found between the Western Aphasia Battery scores and right hemisphere metabolic measures. Most left hemisphere regions correlated with more than one score from the Western Aphasia Battery. Temporal but not frontal regions had significant correlations to the comprehension score. The left temporoparietal region was consistently affected in these subjects, suggesting that common features in the aphasias were caused by left temporoparietal dysfunction, while behavioral differences resulted from (1) the extent of temporoparietal changes, and (2) dysfunction elsewhere in the brain, particularly the left frontal and subcortical areas.

  5. Diagnosis and evaluation of gastric cancer by positron emission tomography

    Science.gov (United States)

    Wu, Chen-Xi; Zhu, Zhao-Hui

    2014-01-01

    Gastric cancer is the second leading cause of cancer mortality worldwide. The diagnosis of gastric cancer has been significantly improved with the broad availability of gastrointestinal endoscopy. Effective technologies for accurate staging and quantitative evaluation are still in demand to merit reasonable treatment and better prognosis for the patients presented with advanced disease. Preoperative staging using conventional imaging tools, such as computed tomography (CT) and endoscopic ultrasonography, is inadequate. Positron emission tomography (PET), using 18F-fluorodeoxyglucose (FDG) as a tracer and integrating CT for anatomic localization, holds a promise to detect unsuspected metastasis and has been extensively used in a variety of malignancies. However, the value of FDG PET/CT in diagnosis and evaluation of gastric cancer is still controversial. This article reviews the current literature in diagnosis, staging, response evaluation, and relapse monitoring of gastric cancer, and discusses the current understanding, improvement, and future prospects in this area. PMID:24782610

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

    Directory of Open Access Journals (Sweden)

    H. Nagasawa

    1993-01-01

    Full Text Available 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 of blood flow and oxygen metabolism. This unique combination study measuring both cerebral glucose utilization and dopamine metabolism in the nigrostriatal system can provide efficient information about the dysfunctions which are correlated with individual clinical symptoms, and this study is essential to diagnosis of corticobasal degeneration.

  7. [Evaluation of pulmonary lesions with positron emission tomography].

    Science.gov (United States)

    Knopp, M V; Bischoff, H G

    1994-10-01

    Positron emission tomography (PET) with fluor-18-labeled deoxyglucose (FDG) enables metabolically oriented imaging of intrapulmonary lesions. PET is currently not used for the detection of lung metastases, but for further diagnostic differentiation of nodules that have already been detected. The diagnostic accuracy of FDG-PET is currently dependent on the size of the metastatic lesions and the uptake intensity. Significantly increased FDG uptake is strongly suggestive of malignant disease whatever the size of lesion concerned. Differentiation of a solitary metastasis from a primary lung tumor is not possible. Slightly elevated FDG uptake can also be found in tuberculosis, sarcoidosis and other granulomatous or inflammatory processes. Exclusion of metastatic disease with PET is currently only reliably possible for lesions larger than 2.0 cm in diameter, owing to respiratory motion and effects of partial volume.

  8. Guideline for performance evaluation of positron emission tomographs

    International Nuclear Information System (INIS)

    1994-01-01

    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.)

  9. Positron emission tomography with gamma camera in coincidence mode

    International Nuclear Information System (INIS)

    Hertel, A.; Hoer, G.

    1999-01-01

    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.) [de

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

    International Nuclear Information System (INIS)

    Schwartz, J.M.; Baxter, L.R. Jr.; Mazziotta, J.C.; Gerner, R.H.; Phelps, M.E.

    1987-01-01

    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

  11. Serotonin synthesis studied with positron emission tomography, (PET)

    DEFF Research Database (Denmark)

    Honoré, Per Gustaf Hartvig; Lundquist, Pinelopi

    Positron emission tomography (PET) has the potential to study the biosynthesis and release of serotonin (5HT) at brain serotonergic neurons. PET requires probe compounds with specific attributes to enable imaging and quantification of biological processes. This section focuses on probes to measure...... seroonin synthesis rate. Knowledge of altered 5HT synthesis and release in disease states may furnish basis for effective pharmacotherapy that may improve the care of psychiatric and neurological disease. Validation of PET measurements of the two PET tracers using perturbation showed that 5-hydroxy...... different from those of 5HTP, suggesting that the two PET probes provide estimates related to the enzyme activity of different steps in the 5HT synthesis pathway. Applications of the two tracers HTP and AMT are reviewed. Up to now, 5HTP has mainly been used for the detection, staging and treatment...

  12. Lesion detection and quantitation of positron emission mammography

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Jinyi; Huesman, Ronald H.

    2001-12-01

    A Positron Emission Mammography (PEM) scanner dedicated to breast imaging is being developed at our laboratory. We have developed a list mode likelihood reconstruction algorithm for this scanner. Here we theoretically study the lesion detection and quantitation. The lesion detectability is studied theoretically using computer observers. We found that for the zero-order quadratic prior, the region of interest observer can achieve the performance of the prewhitening observer with a properly selected smoothing parameter. We also study the lesion quantitation using the test statistic of the region of interest observer. The theoretical expressions for the bias, variance, and ensemble mean squared error of the quantitation are derived. Computer simulations show that the theoretical predictions are in good agreement with the Monte Carlo results for both lesion detection and quantitation.

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

    International Nuclear Information System (INIS)

    Brard, Emmanuel

    2013-01-01

    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)

  14. Development of the LBNL positron emission mammography camera

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Jennifer S.; Choong, Woon-Seng; Wang, Jimmy; Maltz, Jonathon S.; Qi, Jinyi; Mandelli, Emanuele; Moses, William W.

    2002-12-19

    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.

  15. A Review on Segmentation of Positron Emission Tomography Images

    Science.gov (United States)

    Foster, Brent; Bagci, Ulas; Mansoor, Awais; Xu, Ziyue; Mollura, Daniel J.

    2014-01-01

    Positron Emission Tomography (PET), a non-invasive functional imaging method at the molecular level, images the distribution of biologically targeted radiotracers with high sensitivity. PET imaging provides detailed quantitative information about many diseases and is often used to evaluate inflammation, infection, and cancer by detecting emitted photons from a radiotracer localized to abnormal cells. In order to differentiate abnormal tissue from surrounding areas in PET images, image segmentation methods play a vital role; therefore, accurate image segmentation is often necessary for proper disease detection, diagnosis, treatment planning, and follow-ups. In this review paper, we present state-of-the-art PET image segmentation methods, as well as the recent advances in image segmentation techniques. In order to make this manuscript self-contained, we also briefly explain the fundamentals of PET imaging, the challenges of diagnostic PET image analysis, and the effects of these challenges on the segmentation results. PMID:24845019

  16. Temporoparietal cortex in aphasia. Evidence from positron emission tomography

    International Nuclear Information System (INIS)

    Metter, E.J.; Hanson, W.R.; Jackson, C.A.; Kempler, D.; van Lancker, D.; Mazziotta, J.C.; Phelps, M.E.

    1990-01-01

    Forty-four aphasic patients were examined with (F18)-fluorodeoxyglucose positron emission tomography in a resting state to determine whether consistent glucose metabolic abnormalities were present. Ninety-seven percent of subjects showed metabolic abnormalities in the angular gyrus, 89% in the supramarginal gyrus, and 87% in the lateral and transverse superior temporal gyrus. Pearson product moment correlations were calculated between regional metabolic measures and performance on the Western Aphasia Battery. No significant correlations were found between the Western Aphasia Battery scores and right hemisphere metabolic measures. Most left hemisphere regions correlated with more than one score from the Western Aphasia Battery. Temporal but not frontal regions had significant correlations to the comprehension score. The left temporoparietal region was consistently affected in these subjects, suggesting that common features in the aphasias were caused by left temporoparietal dysfunction, while behavioral differences resulted from (1) the extent of temporoparietal changes, and (2) dysfunction elsewhere in the brain, particularly the left frontal and subcortical areas

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

    International Nuclear Information System (INIS)

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

    1995-01-01

    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

  18. 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.

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

    International Nuclear Information System (INIS)

    Metter, E.J.; Wasterlain, C.G.; Kuhl, D.E.; Hanson, W.R.; Phelps, M.E.

    1981-01-01

    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

  20. Positron emission tomography evaluation of sedative properties of antihistamines.

    Science.gov (United States)

    Yanai, Kazuhiko; Zhang, Dongying; Tashiro, Manabu; Yoshikawa, Takeo; Naganuma, Fumito; Harada, Ryuichi; Nakamura, Tadaho; Shibuya, Katsuhiko; Okamura, Nobuyuki

    2011-07-01

    H(1) antihistamines are often used in the medication for allergic diseases, coughs and colds, and insomnia, with or without prescription, even though their sedative properties are a potentially dangerous unwanted side effect that is not properly recognized. These sedative properties have been evaluated using the incidence of subjective sleepiness, objective cognitive and psychomotor functions, and positron emission tomography (PET) measurement of H(1) receptor occupancy. This article reviews the current updated literature on the sedative properties of antihistamines examined by PET measurement of H(1) receptor occupancy. The use of PET to examine antihistamine penetration in the human brain in relation to psychometric and other functional measures of CNS effects is a major breakthrough and provides a new standard by which the functional CNS effects of antihistamines can be related directly to H(1) receptor occupancy. Therapy with antihistamines can be better guided by considering histamine H(1) receptor occupancy from the view of their sedative properties.

  1. Antiretroviral Tissue Kinetics: In Vivo Imaging Using Positron Emission Tomography▿

    Science.gov (United States)

    Di Mascio, Michele; Srinivasula, Sharat; Bhattacharjee, Abesh; Cheng, Lily; Martiniova, Lucia; Herscovitch, Peter; Lertora, Juan; Kiesewetter, Dale

    2009-01-01

    Our current knowledge on the antiviral efficacy, dosing, and toxicity of available highly active antiretroviral therapy regimens is mostly derived from plasma or blood kinetics of anti-human immunodeficiency virus (anti-HIV) drugs. However, the blood comprises only 2% of the total target cells in the body. Tissue drug levels may differ substantially from corresponding plasma levels, and drug distribution processes may be characterized by high intertissue variability, leading to suboptimal target site concentrations and the potential risk for therapeutic failures. Positron emission tomography has greatly expanded the scope of the pharmacokinetic measurements that can be performed noninvasively in animal models or humans. We have prepared [18F]FPMPA, a fluorine-18-radiolabeled analogue of tenofovir, to study antiretroviral tissue kinetics in vivo noninvasively and tested the imaging probe in rats. The biodistribution of the fluorine-18 analogue closely follows that of nonfluorinated tenofovir. Compared to that in the blood, the levels of penetration of the antiretroviral drug were found to be significantly reduced in the spleen and submandibular lymph nodes (∼2-fold), in the mesenteric lymph nodes and the testes (∼4-fold), and in the brain compartment (∼25-fold). Intersubject variability of the trough drug concentration (measured at 120 min) in certain tissues, like the colon (coefficient of variation, >100%), is not reflected by the intersubject variability in the blood compartment (coefficient of variation, 24%). Positron emission tomography imaging of the fluorine-18 analogue revealed the accumulation of the antiretroviral drug in the cortex of the kidneys, a potential correlate of tenofovir-induced nephrotoxicity observed in HIV-1-infected treated patients. Thus, [18F]FPMPA is a promising radiotracer for evaluation of tenofovir biodistribution under carefully controlled drug administration protocols. PMID:19667288

  2. Antiretroviral tissue kinetics: in vivo imaging using positron emission tomography.

    Science.gov (United States)

    Di Mascio, Michele; Srinivasula, Sharat; Bhattacharjee, Abesh; Cheng, Lily; Martiniova, Lucia; Herscovitch, Peter; Lertora, Juan; Kiesewetter, Dale

    2009-10-01

    Our current knowledge on the antiviral efficacy, dosing, and toxicity of available highly active antiretroviral therapy regimens is mostly derived from plasma or blood kinetics of anti-human immunodeficiency virus (anti-HIV) drugs. However, the blood comprises only 2% of the total target cells in the body. Tissue drug levels may differ substantially from corresponding plasma levels, and drug distribution processes may be characterized by high intertissue variability, leading to suboptimal target site concentrations and the potential risk for therapeutic failures. Positron emission tomography has greatly expanded the scope of the pharmacokinetic measurements that can be performed noninvasively in animal models or humans. We have prepared [18F]FPMPA, a fluorine-18-radiolabeled analogue of tenofovir, to study antiretroviral tissue kinetics in vivo noninvasively and tested the imaging probe in rats. The biodistribution of the fluorine-18 analogue closely follows that of nonfluorinated tenofovir. Compared to that in the blood, the levels of penetration of the antiretroviral drug were found to be significantly reduced in the spleen and submandibular lymph nodes (approximately 2-fold), in the mesenteric lymph nodes and the testes (approximately 4-fold), and in the brain compartment (approximately 25-fold). Intersubject variability of the trough drug concentration (measured at 120 min) in certain tissues, like the colon (coefficient of variation, >100%), is not reflected by the intersubject variability in the blood compartment (coefficient of variation, 24%). Positron emission tomography imaging of the fluorine-18 analogue revealed the accumulation of the antiretroviral drug in the cortex of the kidneys, a potential correlate of tenofovir-induced nephrotoxicity observed in HIV-1-infected treated patients. Thus, [18F]FPMPA is a promising radiotracer for evaluation of tenofovir biodistribution under carefully controlled drug administration protocols.

  3. Fluorinated tracers for imaging cancer with positron emission tomography.

    Science.gov (United States)

    Couturier, Olivier; Luxen, André; Chatal, Jean-François; Vuillez, Jean-Philippe; Rigo, Pierre; Hustinx, Roland

    2004-08-01

    2-[18F]fluoro-2-deoxy-D-glucose (FDG) is currently the only fluorinated tracer used in routine clinical positron emission tomography (PET). Fluorine-18 is considered the ideal radioisotope for PET imaging owing to the low positron energy (0.64 MeV), which not only limits the dose rate to the patient but also results in a relatively short range of emission in tissue, thereby providing high-resolution images. Further, the 110-min physical half-life allows for high-yield radiosynthesis, transport from the production site to the imaging site and imaging protocols that may span hours, which permits dynamic studies and assessment of potentially fairly slow metabolic processes. The synthesis of fluorinated tracers as an alternative to FDG was initially tested using nucleophilic fluorination of the molecule, as performed when radiolabelling with iodine-124 or bromide-76. However, in addition to being long, with multiple steps, this procedure is not recommended for bioactive molecules containing reactive groups such as amine or thiol groups. Radiochemical yields are also often low. More recently, radiosynthesis from prosthetic group precursors, which allows easier radiolabelling of biomolecules, has led to the development of numerous fluorinated tracers. Given the wide availability of 18F, such tracers may well develop into important routine tracers. This article is a review of the literature concerning fluorinated radiotracers recently developed and under investigation for possible PET imaging in cancer patients. Two groups can be distinguished. The first includes "generalist" tracers, i.e. tracers amenable to use in a wide variety of tumours and indications, very similar in this respect to FDG. These are tracers for non-specific cell metabolism, such as protein synthesis, amino acid transport, nucleic acid synthesis or membrane component synthesis. The second group consists of "specific" tracers for receptor expression (i.e. oestrogens or somatostatin), cell hypoxia or

  4. Fluorinated tracers for imaging cancer with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Couturier, Olivier; Chatal, Jean-Francois [Division of Nuclear Medicine, Hotel Dieu, CHU, Nantes (France); Luxen, Andre [Centre de Recherche du Cyclotron, University of Liege, Liege (Belgium); Vuillez, Jean-Philippe [Division of Nuclear Medicine, CHU, Grenoble (France); Rigo, Pierre [Division of Nuclear Medicine, Hopital Princesse Grace, Monte Carlo (Monaco); Hustinx, Roland [Division of Nuclear Medicine, CHU, Liege (Belgium)

    2004-08-01

    2-[{sup 18}F]fluoro-2-deoxy-d-glucose (FDG) is currently the only fluorinated tracer used in routine clinical positron emission tomography (PET). Fluorine-18 is considered the ideal radioisotope for PET imaging owing to the low positron energy (0.64 MeV), which not only limits the dose rate to the patient but also results in a relatively short range of emission in tissue, thereby providing high-resolution images. Further, the 110-min physical half-life allows for high-yield radiosynthesis, transport from the production site to the imaging site and imaging protocols that may span hours, which permits dynamic studies and assessment of potentially fairly slow metabolic processes. The synthesis of fluorinated tracers as an alternative to FDG was initially tested using nucleophilic fluorination of the molecule, as performed when radiolabelling with iodine-124 or bromide-76. However, in addition to being long, with multiple steps, this procedure is not recommended for bioactive molecules containing reactive groups such as amine or thiol groups. Radiochemical yields are also often low. More recently, radiosynthesis from prosthetic group precursors, which allows easier radiolabelling of biomolecules, has led to the development of numerous fluorinated tracers. Given the wide availability of{sup 18}F, such tracers may well develop into important routine tracers. This article is a review of the literature concerning fluorinated radiotracers recently developed and under investigation for possible PET imaging in cancer patients. Two groups can be distinguished. The first includes ''generalist'' tracers, i.e. tracers amenable to use in a wide variety of tumours and indications, very similar in this respect to FDG. These are tracers for non-specific cell metabolism, such as protein synthesis, amino acid transport, nucleic acid synthesis or membrane component synthesis. The second group consists of ''specific'' tracers for receptor

  5. 76 FR 6143 - Draft Guidance on Positron Emission Tomography Drug Applications-Content and Format for New Drug...

    Science.gov (United States)

    2011-02-03

    ...; formerly Docket No. 00D-0892] Draft Guidance on Positron Emission Tomography Drug Applications--Content and... Applications for Certain Positron Emission Tomography Drug Products; Availability,'' issued on March 10, 2000... and ANDAs.'' The draft guidance is intended to assist manufacturers of certain positron emission...

  6. 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 ...

  7. High-resolution fluorodeoxyglucose positron emission tomography with compression ("positron emission mammography") is highly accurate in depicting primary breast cancer.

    Science.gov (United States)

    Berg, Wendie A; Weinberg, Irving N; Narayanan, Deepa; Lobrano, Mary E; Ross, Eric; Amodei, Laura; Tafra, Lorraine; Adler, Lee P; Uddo, Joseph; Stein, William; Levine, Edward A

    2006-01-01

    We sought to prospectively assess the diagnostic performance of a high-resolution positron emission tomography (PET) scanner using mild breast compression (positron emission mammography [PEM]). Data were collected on concomitant medical conditions to assess potential confounding factors. At four centers, 94 consecutive women with known breast cancer or suspicious breast lesions received 18F-fluorodeoxyglucose (FDG) intravenously, followed by PEM scans. Readers were provided clinical histories and x-ray mammograms (when available). After excluding inevaluable cases and two cases of lymphoma, PEM readings were correlated with histopathology for 92 lesions in 77 women: 77 index lesions (42 malignant), 3 ipsilateral lesions (3 malignant), and 12 contralateral lesions (3 malignant). Of 48 cancers, 16 (33%) were clinically evident; 11 (23%) were ductal carcinoma in situ (DCIS), and 37 (77%) were invasive (30 ductal, 4 lobular, and 3 mixed; median size 21 mm). PEM depicted 10 of 11 (91%) DCIS and 33 of 37 (89%) invasive cancers. PEM was positive in 1 of 2 T1a tumors, 4 of 6 T1b tumors, 7 of 7 T1c tumors, and 4 of 4 cases where tumor size was not available (e.g., no surgical follow-up). PEM sensitivity for detecting cancer was 90%, specificity 86%, positive predictive value (PPV) 88%, negative predictive value (NPV) 88%, accuracy 88%, and area under the receiver-operating characteristic curve (Az) 0.918. In three patients, cancer foci were identified only on PEM, significantly changing patient management. Excluding eight diabetic subjects and eight subjects whose lesions were characterized as clearly benign with conventional imaging, PEM sensitivity was 91%, specificity 93%, PPV 95%, NPV 88%, accuracy 92%, and Az 0.949 when interpreted with mammographic and clinical findings. FDG PEM has high diagnostic accuracy for breast lesions, including DCIS.

  8. Novel targets for positron emission tomography (PET) radiopharmaceutical tracers for visualization of neuroinflammation

    Science.gov (United States)

    Shchepetkin, I.; Shvedova, M.; Anfinogenova, Y.; Litvak, M.; Atochin, D.

    2017-08-01

    Non-invasive molecular imaging techniques can enhance diagnosis of neurological diseases to achieve their successful treatment. Positron emission tomography (PET) imaging can identify activated microglia and provide detailed functional information based on molecular biology. This imaging modality is based on detection of isotope labeled tracers, which emit positrons. The review summarizes the developments of various radiolabeled ligands for PET imaging of neuroinflammation.

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

    International Nuclear Information System (INIS)

    Labas, R.

    2007-01-01

    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 ( 11 C or 18 F)

  10. Transthoracic Doppler echocardiography compared with positron emission tomography for assessment of coronary microvascular dysfunction

    DEFF Research Database (Denmark)

    Michelsen, Marie Mide; Mygind, Naja Dam; Pena, Adam

    2017-01-01

    BACKGROUND: Coronary microvascular function can be assessed by transthoracic Doppler echocardiography as a coronary flow velocity reserve (TTDE CFVR) and by positron emission tomography as a myocardial blood flow reserve (PET MBFR). PET MBFR is regarded the noninvasive reference standard...

  11. 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

    , 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...

  12. Estimation of intersubject variability of cerebral blood flow measurements using MRI and positron emission tomography

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Larsson, Henrik B W; Hansen, Adam E

    2012-01-01

    PURPOSE: To investigate the within and between subject variability of quantitative cerebral blood flow (CBF) measurements in normal subjects using various MRI techniques and positron emission tomography (PET). MATERIALS AND METHODS: Repeated CBF measurements were performed in 17 healthy, young...

  13. Readout of scintillator light with avalanche photodiodes for positron emission tomography

    International Nuclear Information System (INIS)

    Chen, Ruru; Fremout, A.; Tavernier, S.; Bruyndonckx, P.; Clement, D.; Loude, J.-F.; Morel, C.

    1999-01-01

    The noise properties and other relevant characteristics of avalanche photodiodes have been investigated with the perspective of replacing photomultiplier tubes in positron emission tomography. It is clearly demonstrated that they are a valid alternative to photomultiplier tubes in this application

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

    International Nuclear Information System (INIS)

    Baron, J.C.

    1986-05-01

    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 [fr

  15. Positron Emission Tomography with Three-Dimensional Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, K.

    1996-10-01

    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.

  16. Positron emission tomography/computed tomography imaging and rheumatoid arthritis.

    Science.gov (United States)

    Wang, Shi-Cun; Xie, Qiang; Lv, Wei-Fu

    2014-03-01

    Rheumatoid arthritis (RA) is a phenotypically heterogeneous, chronic, destructive inflammatory disease of the synovial joints. A number of imaging tools are currently available for evaluation of inflammatory conditions. By targeting the upgraded glucose uptake of infiltrating granulocytes and tissue macrophages, positron emission tomography/computed tomography with fluorine-18 fluorodeoxyglucose ((18) F-FDG PET/CT) is available to delineate inflammation with high sensitivity. Recently, several studies have indicated that FDG uptake in affected joints reflects the disease activity of RA. In addition, usage of FDG PET for the sensitive detection and monitoring of the response to treatment has been reported. Combined FDG PET/CT enables the detailed assessment of disease in large joints throughout the whole body. These unique capabilities of FDG PET/CT imaging are also able to detect RA-complicated diseases. Therefore, PET/CT has become an excellent ancillary tool to assess disease activity and prognosis in RA. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  17. Relevance of positron emission tomography (PET) in oncology

    International Nuclear Information System (INIS)

    Weber, W.A.; Avril, N.; Schwaiger, M.

    1999-01-01

    Background: The clinical use of positron emission tomography (PET) for detection and staging of malignant tumors is rapidly increasing. Furthermore, encouraging results for monitoring the effects of radio- and chemotherapy have been reported. Methods: This review describes the technical principles of PET and the biological characteristics of tracers used in oncological research and patient studies. The results of clinical studies published in peer reviewed journals during the last 5 years are summarized and clinical indications for PET scans in various tumor types are discussed. Results and Conclusions: Numerous studies have documented the high diagnostic accuracy of PET studies using the glucose analogue F-18-fluordeoxyglucose (FDG-PET) for detection and staging of malignant tumors. In this field, FDG-PET has been particularly successful in lung cancer, colorectal cancer, malignant lymphoma and melanoma. Furthermore, FDG-PET has often proven to be superior to morphological imaging techniques for differentation of tumor recurrence from scar tissue. Due to the high glucose utilization of normal gray matter radiolabeled amino-acids like C-11-methionine are superior to FDG for detection and delineation of brain tumors by PET. In the future, more specific markers of tumor cell proliferation and gene expression may allow the application of PET not only for dianostic imaging also but for non-invasive biological characterization of malignant tumors and early monitoring of therapeutic interventions. (orig.) [de

  18. FPGA-Based Pulse Parameter Discovery for Positron Emission Tomography.

    Science.gov (United States)

    Haselman, Michael; Hauck, Scott; Lewellen, Thomas K; Miyaoka, Robert S

    2009-10-24

    Modern Field Programmable Gate Arrays (FPGAs) are capable of performing complex digital signal processing algorithms with clock rates well above 100MHz. This, combined with FPGA's low expense and ease of use make them an ideal technology for a data acquisition system for a positron emission tomography (PET) scanner. The University of Washington is producing a series of high-resolution, small-animal PET scanners that utilize FPGAs as the core of the front-end electronics. For these next generation scanners, functions that are typically performed in dedicated circuits, or offline, are being migrated to the FPGA. This will not only simplify the electronics, but the features of modern FPGAs can be utilizes to add significant signal processing power to produce higher resolution images. In this paper we report how we utilize the reconfigurable property of an FPGA to self-calibrate itself to determine pulse parameters necessary for some of the pulse processing steps. Specifically, we show how the FPGA can generate a reference pulse based on actual pulse data instead of a model. We also report how other properties of the photodetector pulse (baseline, pulse length, average pulse energy and event triggers) can be determined automatically by the FPGA.

  19. Quantitative Cardiac Positron Emission Tomography: The Time Is Coming!

    Directory of Open Access Journals (Sweden)

    Roberto Sciagrà

    2012-01-01

    Full Text Available In the last 20 years, the use of positron emission tomography (PET has grown dramatically because of its oncological applications, and PET facilities are now easily accessible. At the same time, various groups have explored the specific advantages of PET in heart disease and demonstrated the major diagnostic and prognostic role of quantitation in cardiac PET. Nowadays, different approaches for the measurement of myocardial blood flow (MBF have been developed and implemented in user-friendly programs. There is large evidence that MBF at rest and under stress together with the calculation of coronary flow reserve are able to improve the detection and prognostication of coronary artery disease. Moreover, quantitative PET makes possible to assess the presence of microvascular dysfunction, which is involved in various cardiac diseases, including the early stages of coronary atherosclerosis, hypertrophic and dilated cardiomyopathy, and hypertensive heart disease. Therefore, it is probably time to consider the routine use of quantitative cardiac PET and to work for defining its place in the clinical scenario of modern cardiology.

  20. Quality assurance and radiation safety in positron emission tomography

    International Nuclear Information System (INIS)

    Kmetyuk, Ya.V.; Radosh, H.V.; Bezshyyko, O.A.; Golinka-Bezshyyko, L.O.; Kadenko, I.M.; Kazinova, O.A.; Nagai, A.O.

    2012-01-01

    Scientific studies, clinical experience and economic analysis have shown that the positron emission tomography (PET) is clinically and cost effective cancer diagnostics method. Combined PET and computed tomography (PET/CT) has proven clinical utility, particularly in the diagnosis, staging or restaging malignant disease and metastases, surgical planning, radiation therapy planning and evaluation of treatment response. The use of PET/CT has grown substantially in the past few years, with an increasing number of hospitals and installations of PET/CT imaging centers each year. In the same time combination of 2 procedures, each of which impart a radiation dose and, as a result, increases the deleterious influence for health, creates additional radiation safety issues. In these conditions the role of quality assurance (QA) and quality control (QC) programs is getting more and more important. We considered main QA and radiation safety requirements for whole PET technology chain from radio-pharmacy facilities to PET/CT scanning and patient release criteria. All these issues were considered and assessed having the example of PET facilities and technology chain of All-Ukrainian Center for Radiosurgery of the Clinical Hospital 'Feofania'

  1. Positron emission tomography imaging in evaluation of cancer patients

    International Nuclear Information System (INIS)

    Kumar, R.; Bhargava, P.; Bozkurt, M.F.; Zhuang, H.; Potenta, S.; Alavi, A.

    2003-01-01

    Positron emission tomography (PET) is a diagnostic imaging technique that has progressed rapidly from being a research technique in laboratories to a routine clinical imaging modality. The most widely used radiotracer in PET is Fluorine18-fluorodeoxyglucose (F18-FDG), which is an analogue of glucose. The FDG uptake in cells is directly proportional to glucose metabolism of cells. Since glucose metabolism is increased many fold in malignant tumors PET has a high sensitivity and a high negative predictive value. PET with FDG is now the standard of care in initial staging, monitoring the response to the therapy, and management of lung cancer, colonic cancer, lymphoma, melanoma, esophageal cancer, head and neck cancer and breast cancer. Other indications of PET like bone tumor, ovarian cancer and cancer of unknown primary (CUP) has also been discussed in brief. The aim of this review article is to review the clinical applications of PET in various malignancies and only limited number of important studies will be discussed for this effort. (author)

  2. 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.

  3. 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...

  4. Simultaneous laser speckle imaging and positron emission tomography

    Science.gov (United States)

    Gramer, M.; Feuerstein, D.; Backes, H.; Takagaki, M.; Kumagai, T.; Graf, R.

    2013-06-01

    Complex biological systems often require measurements of multiple parameters with high temporal and spatial resolution. Multimodal approaches and the combination of methods are therefore a powerful tool to address such scientific questions. Laser speckle imaging (LSI) is an optical method that monitors dynamic changes in cortical blood flow (CBF) with high temporal resolution. Positron emission tomography (PET) allows for quantitative imaging of physiological processes and is a gold standard method to determine absolute cerebral blood flow. We developed a setup that allows simultaneous measurement with both modalities. Here, we simultaneously measured CBF with PET and LSI in rats and analyzed how the correlation of PET and LSI is modified when (1) different methods are used for the calculation of speckle inverse correlation time (ICT), (2) speckle data is acquired through thinned or craniectomized skull, (3) influence of surface vessels is removed from the speckle data. For the latter, a method for automated vessel segmentation from LSI data was developed. We obtained the best correlation (R² = 0.890, pICT. Thus, LSI provides CBF in absolute units at high temporal resolution.

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

    International Nuclear Information System (INIS)

    Sureau, F.

    2008-06-01

    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)

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

    International Nuclear Information System (INIS)

    Herscovitch, P.; Powers, W.J.

    1987-01-01

    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

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

    International Nuclear Information System (INIS)

    Tang Ganghua; Wu Guangyuan

    2007-01-01

    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. 11 C-Choline (CH) and 11 C-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 11 C prevents the widespread use of CH and AC and 18 F-fluorocholine (FCH) and 18 F-fluoroacetate (FAC) seem to be potential tracers. Potential clinical value of the new PET tracers, such as 3'-deoxy-3'- 18 F-fluorothymidine (FLT), 18 F-fluorodihydrotestosterone (FDHT), and 9-(4- 18 F-3-hydroxymethylbutyl)-guanine( 18 F-FHBG) in the detection of urologic tumors, can deserve further study. (authors)

  8. Positron emission mammography: high-resolution biochemical breast imaging.

    Science.gov (United States)

    Weinberg, Irving N; Beylin, David; Zavarzin, Valera; Yarnall, Steve; Stepanov, Pavel Y; Anashkin, Edward; Narayanan, Deepa; Dolinsky, Sergei; Lauckner, Kathrin; Adler, Lee P

    2005-02-01

    Positron emission mammography (PEM) provides images of biochemical activity in the breast with spatial resolution matching individual ducts (1.5 mm full-width at half-maximum). This spatial resolution, supported by count efficiency that results in high signal-to-noise ratio, allows confident visualization of intraductal as well as invasive breast cancers. Clinical trials with a full-breast PEM device have shown high clinical accuracy in characterizing lesions identified as suspicious on the basis of conventional imaging or physical examination (sensitivity 93%, specificity 83%, area under the ROC curve of 0.93), with high sensitivity preserved (91%) for intraductal cancers. Increased sensitivity did not come at a cost of reduced specificity. Considering that intraductal cancer represents more than 30% of reported cancers, and is the form of cancer with the highest probability of achieving surgical cure, it is likely that the use of PEM will complement anatomic imaging modalities in the areas of surgical planning, high-risk monitoring, and minimally invasive therapy. The quantitative nature of PET promises to assist researchers interested studying the response of putative cancer precursors (e.g., atypical ductal hyperplasia) to candidate prevention agents.

  9. Positron emission mammography (PEM): reviewing standardized semiquantitative method.

    Science.gov (United States)

    Yamamoto, Yayoi; Tasaki, Youichiro; Kuwada, Yukiko; Ozawa, Yukihiko; Katayama, Atsushi; Kanemaki, Yoshihide; Enokido, Katsutoshi; Nakamura, Seigo; Kubouchi, Kouichi; Morita, Satoshi; Noritake, Mutsumi; Nakajima, Yasuo; Inoue, Tomio

    2013-11-01

    To validate semiquantitative analysis of positron emission mammography (PEM). Fifty women with histologically confirmed breast lesions were retrospectively enrolled. Semiquantitative uptake values (4 methods), the maximum PEM uptake value (PUVmax), and the lesion-to-background (LTB) value (3 methods) were measured. LTB is a ratio of the lesion's PUVmax to the mean background; LTB1, LTB2, and LTB3 (which were calculated on different background) were used to designate the three values measured. Interobserver reliability between two readers for PUVmax and the LTBs was tested using the interobserver correlation coefficient (ICC). The likelihood ratio test was used to evaluate the relationship between ICCs. Receiver operating characteristic (ROC) curves were calculated for all methods. Diagnostic accuracy in differentiating benign tissue from malignant tissue was compared between PUVmax and LTB1. The ICC rate was 0.971 [95 % confidence interval (CI) 0.943-0.986] for PUVmax, 0.873 (95 % CI 0.758-0.935) for LTB1, 0.965 (95 % CI 0.925-0.983) for LTB2, and 0.895 (95 % CI 0.799-0.946) for LTB3. However, there were some technical difficulties in the practical use of LTB2 and LTB3. The likelihood ratio test between PUVmax and LTB1 was statistically significant (p PEM in semiquantitative analysis.

  10. Comparison of scintillators for positron emission mammography (PEM) systems

    Energy Technology Data Exchange (ETDEWEB)

    Raymond Raylman; Stanislaw Majewski; Mark Smith; Randolph Wojcik; Andrew Weisenberger; Brian Kross; Vladimir Popov; Jamal J. Derakhshan

    2003-02-01

    Positron emission mammography (PEM) has promise as an effective method for the detection of breast lesions. Perhaps the most significant design feature of a PEM system is the choice of scintillator material. In this investigation we compared three scintillators for use in PEM: NaI(Tl), gadolinium oxyorthosilicate (GSO), and lutetium-gadolinium oxyorthosilicate (LGSO). The PEM systems consisted of two 30/spl times/30 arrays of pixelated scintillators (3/spl times/3/spl times/10 mm/sup 3/ for GSO and LGSO and 3/spl times/3/spl times/19 mm/sup 3/ for NaI(Tl)) coupled to arrays of square position-sensitive photomultiplier tubes. The Compton scatter fraction, system energy resolution, spatial resolution, spatial resolution uniformity, and detection sensitivity were compared. Compton scatter fractions for the systems were comparable, between 8% and 9%. The NaI(Tl) system produced the best system energy resolution (18.2%), the GSO system had the worst system energy resolution (28.7%).

  11. Florbetapir positron emission tomography and cerebrospinal fluid biomarkers

    Science.gov (United States)

    Hake, Ann; Trzepacz, Paula T.; Wang, Shufang; Yu, Peng; Case, Michael; Hochstetler, Helen; Witte, Michael M.; Degenhardt, Elisabeth K.; Dean, Robert A.

    2015-01-01

    Background We evaluated the relationship between florbetapir-F18 positron emission tomography (FBP PET) and cerebrospinal fluid (CSF) biomarkers. Methods Alzheimer’s Disease Neuroimaging Initiative (ADNI)-GO/2 healthy control (HC), mild cognitive impairment (MCI), and Alzheimer’s disease (AD) dementia subjects with clinical measures and CSF collected ±90 days of FBP PET data were analyzed using correlation and logistic regression. Results In HC and MCI subjects, FBP PET anterior and posterior cingulate and composite standard uptake value ratios correlated with CSF amyloid beta (Aβ1-42) and tau/Aβ1-42 ratios. Using logistic regression, Aβ1-42, total tau (t-tau), phosphorylated tau181P (p-tau), and FBP PET composite each differentiated HC versus AD. Aβ1-42 and t-tau distinguished MCI versus AD, without additional contribution by FBP PET. Total tau and p-tau added discriminative power to FBP PET when classifying HC versus AD. Conclusion Based on cross-sectional diagnostic groups, both amyloid and tau measures distinguish healthy from demented subjects. Longitudinal analyses are needed. PMID:25916563

  12. Positron emission tomography scans on kanji and kana

    International Nuclear Information System (INIS)

    Sakurai, Yasuhisa

    2002-01-01

    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)

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

    International Nuclear Information System (INIS)

    Geltman, E.M.; Biello, D.; Welch, M.J.; Ter-Pogossian, M.M.; Roberts, R.; Sobel, B.E.

    1982-01-01

    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

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

    Science.gov (United States)

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

    2012-01-01

    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 radiochemistry can lead to the use of smaller quantities of precursors, accelerated reaction rates and easier purification processes with greater yield and higher specific activity of desired probes. Several ‘proof-of-principle’ examples, along with basics of device architecture and operation, and potential limitations of each design are discussed here. Along with the concept of radioisotope distribution from centralized cyclotron facilities to individual imaging centers and laboratories (“decentralized model”), an easy-to-use, standalone, flexible, fully-automated radiochemical microfluidic platform can open up to simpler and more cost-effective procedures for molecular imaging using PET. PMID:20643021

  15. Therapy response evaluation with positron emission tomography-computed tomography.

    Science.gov (United States)

    Segall, George M

    2010-12-01

    Positron emission tomography-computed tomography with F-18-fluorodeoxyglucose is widely used for evaluation of therapy response in patients with solid tumors but has not been as readily adopted in clinical trials because of the variability of acquisition and processing protocols and the absence of universal response criteria. Criteria proposed for clinical trials are difficult to apply in clinical practice, and gestalt impression is probably accurate in individual patients, especially with respect to the presence of progressive disease and complete response. Semiquantitative methods of determining tissue glucose metabolism, such as standard uptake value, can be a useful descriptor for levels of tissue glucose metabolism and changes in response to therapy if technical quality control measures are carefully maintained. The terms partial response, complete response, and progressive disease are best used in clinical trials in which the terms have specific meanings and precise definitions. In clinical practice, it may be better to use descriptive terminology agreed upon by imaging physicians and clinicians in their own practice. Copyright © 2010. Published by Elsevier Inc.

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

    International Nuclear Information System (INIS)

    Holmes, T.J.

    1983-01-01

    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

  17. Variation in positron emission tomography use after colon cancer resection.

    Science.gov (United States)

    Bailey, Christina E; Hu, Chung-Yuan; You, Y Nancy; Kaur, Harmeet; Ernst, Randy D; Chang, George J

    2015-05-01

    Colon cancer surveillance guidelines do not routinely include positron emission tomography (PET) imaging; however, its use after surgical resection has been increasing. We evaluated the secular patterns of PET use after surgical resection of colon cancer among elderly patients and identified factors associated with its increasing use. We used the SEER-linked Medicare database (July 2001 through December 2009) to establish a retrospective cohort of patients age ≥ 66 years who had undergone surgical resection for colon cancer. Postoperative PET use was assessed with the test for trends. Patient, tumor, and treatment characteristics were analyzed using univariable and multivariable logistic regression analyses. Of the 39,221 patients with colon cancer, 6,326 (16.1%) had undergone a PET scan within 2 years after surgery. The use rate steadily increased over time. The majority of PET scans had been performed within 2 months after surgery. Among patients who had undergone a PET scan, 3,644 (57.6%) had also undergone preoperative imaging, and 1,977 (54.3%) of these patients had undergone reimaging with PET within 2 months after surgery. Marriage, year of diagnosis, tumor stage, preoperative imaging, postoperative visit to a medical oncologist, and adjuvant chemotherapy were significantly associated with increased PET use. PET use after colon cancer resection is steadily increasing, and further study is needed to understand the clinical value and effectiveness of PET scans and the reasons for this departure from guideline-concordant care. Copyright © 2015 by American Society of Clinical Oncology.

  18. Synthesis of the radiopharmaceuticals for positron emission tomography

    International Nuclear Information System (INIS)

    Biricova, V.; Kuruc, J.

    2007-01-01

    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. single photon emission tomography and positron emission tomography - Part 1 (October 2012), Part 2 (October 2010)

    International Nuclear Information System (INIS)

    Buvat, Irene

    2010-10-01

    The objective of this lecture is to present the single photon emission computed tomography (SPECT) and the positron emission tomography (PET) imaging techniques. Part 1 Content: 1 - Introduction: anatomic, functional and molecular imaging; 2 - Radiotracers: chemical and physical constraints, gamma photon emitters, positon emitters, radioisotopes production, emitters type and imaging techniques; 3 - Gamma cameras; 4 - Quantification in emission tomography: attenuation, scattering, un-stationary spatial resolution; 5 - Synthesis and conclusion. Part 2 content: 1 - Positon emitters; 2 - Positons detection: Coincidence detection (electronic collimation, PET detectors with gamma cameras, dedicated PET detectors, spectrometry); PET detectors type; time-of-flight PET; 2D PET; 3D PET; 3 - Quantification in emission tomography: detected events, attenuation, scattering, fortuitous coincidences, standardisation; 4 - Common SPECT and PET problems: partial volume effect, movement, tomographic reconstruction, calibration, dead time; 5 - Synthesis and conclusion

  20. Fuzzy-rule-based image reconstruction for positron emission tomography

    Science.gov (United States)

    Mondal, Partha P.; Rajan, K.

    2005-09-01

    Positron emission tomography (PET) and single-photon emission computed tomography have revolutionized the field of medicine and biology. Penalized iterative algorithms based on maximum a posteriori (MAP) estimation eliminate noisy artifacts by utilizing available prior information in the reconstruction process but often result in a blurring effect. MAP-based algorithms fail to determine the density class in the reconstructed image and hence penalize the pixels irrespective of the density class. Reconstruction with better edge information is often difficult because prior knowledge is not taken into account. The recently introduced median-root-prior (MRP)-based algorithm preserves the edges, but a steplike streaking effect is observed in the reconstructed image, which is undesirable. A fuzzy approach is proposed for modeling the nature of interpixel interaction in order to build an artifact-free edge-preserving reconstruction. The proposed algorithm consists of two elementary steps: (1) edge detection, in which fuzzy-rule-based derivatives are used for the detection of edges in the nearest neighborhood window (which is equivalent to recognizing nearby density classes), and (2) fuzzy smoothing, in which penalization is performed only for those pixels for which no edge is detected in the nearest neighborhood. Both of these operations are carried out iteratively until the image converges. Analysis shows that the proposed fuzzy-rule-based reconstruction algorithm is capable of producing qualitatively better reconstructed images than those reconstructed by MAP and MRP algorithms. The reconstructed images are sharper, with small features being better resolved owing to the nature of the fuzzy potential function.

  1. Software development for modeling positrons emission tomograph scanners

    International Nuclear Information System (INIS)

    Vieira, Igor Fagner

    2013-01-01

    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)

  2. Fuzzy-rule-based image reconstruction for positron emission tomography.

    Science.gov (United States)

    Mondal, Partha P; Rajan, K

    2005-09-01

    Positron emission tomography (PET) and single-photon emission computed tomography have revolutionized the field of medicine and biology. Penalized iterative algorithms based on maximum a posteriori (MAP) estimation eliminate noisy artifacts by utilizing available prior information in the reconstruction process but often result in a blurring effect. MAP-based algorithms fail to determine the density class in the reconstructed image and hence penalize the pixels irrespective of the density class. Reconstruction with better edge information is often difficult because prior knowledge is not taken into account. The recently introduced median-root-prior (MRP)-based algorithm preserves the edges, but a steplike streaking effect is observed in the reconstructed image, which is undesirable. A fuzzy approach is proposed for modeling the nature of interpixel interaction in order to build an artifact-free edge-preserving reconstruction. The proposed algorithm consists of two elementary steps: (1) edge detection, in which fuzzy-rule-based derivatives are used for the detection of edges in the nearest neighborhood window (which is equivalent to recognizing nearby density classes), and (2) fuzzy smoothing, in which penalization is performed only for those pixels for which no edge is detected in the nearest neighborhood. Both of these operations are carried out iteratively until the image converges. Analysis shows that the proposed fuzzy-rule-based reconstruction algorithm is capable of producing qualitatively better reconstructed images than those reconstructed by MAP and MR P algorithms. The reconstructed images a resharper, with small features being better resolved owing to the nature of the fuzzy potential function.

  3. RELIABILITY OF POSITRON EMISSION TOMOGRAPHY-COMPUTED TOMOGRAPHY IN EVALUATION OF TESTICULAR CARCINOMA PATIENTS.

    Science.gov (United States)

    Nikoletić, Katarina; Mihailović, Jasna; Matovina, Emil; Žeravica, Radmila; Srbovan, Dolores

    2015-01-01

    The study was aimed at assessing the reliability of 18F-fluorodeoxyglucose positron emission tomography-computed tomography scan in evaluation of testicular carcinoma patients. The study sample consisted of 26 scans performed in 23 patients with testicular carcinoma. According to the pathohistological finding, 14 patients had seminomas, 7 had nonseminomas and 2 patients had a mixed histological type. In 17 patients, the initial treatment was orchiectomy+chemotherapy, 2 patients had orchiectomy+chemotherapy+retroperitoneal lymph node dissection, 3 patients had orchiectomy only and one patient was treated with chemotherapy only. Abnormal computed tomography was the main cause for the oncologist to refer the patient to positron emission tomography-computed tomography scan (in 19 scans), magnetic resonance imaging abnormalities in 1 scan, high level oftumor markers in 3 and 3 scans were perforned for follow-up. Positron emission tomography-computed tomography imaging results were compared with histological results, other imaging modalities or the clinical follow-up of the patients. Positron emission tomography-computed tomography scans were positive in 6 and negative in 20 patients. In two patients, positron emission tomography-computed tomography was false positive. There were 20 negative positron emission omography-computed tomography scans perforned in 18 patients, one patient was lost for data analysis. Clinically stable disease was confirmed in 18 follow-up scans performed in 16 patients. The values of sensitivty, specificity, accuracy, and positive- and negative predictive value were 60%, 95%, 75%, 88% and 90.5%, respectively. A hgh negative predictive value obtained in our study (90.5%) suggests that there is a small possibility for a patient to have future relapse after normal positron emission tomography-computed tomography study. However, since the sensitivity and positive predictive value of the study ire rather low, there are limitations of positive

  4. Analysis of solute transport in plants using positron emission tomography

    International Nuclear Information System (INIS)

    Partelova, D.

    2016-01-01

    In the first part of the work, geometrically and radiochemically characterized standards (phantoms) imitating the plant tissues and allowing the exact quantification of visualised radioindicator in plant tissues were designed and prepared within the study of visual and analytical characteristics of used positron emission tomograph (microPET system) commercially developed for animal objects at visualization of thin objects. Individual experiments carried out by exposure of excised leaves of tobacco (Nicotiana tabacum L.) or radish (Raphanus sativus L.) in solutions of 2-deoxy-2-fluoro-D-glucose labelled with positron emitter 18 F (2-[ 18 F]FDG) containing 10-, 100-, or 1000-times higher concentrations of D-glucose (c glu ) in comparison with the original 2-[ 18 F]FDG solution showed that the significant changes in visualisation of 2-[ 18 F]FDG distribution as well as in chemical portion of 2-[ 18 F]FDG within the leaf blade were observed as result of increased c glu . In the experiments with the whole plants of tobacco or radish exposed in 2-[ 18 F]FDG solution through the root system, only minimal translocation of 18 F radioactivity into the above-ground parts of plants, also in the case of increased c glu , was observed, which suggest the role of root system as a selective barrier of 2-[ 18 F]FDG transport from roots to the above-ground parts. On the basis of mentioned knowledge and analytical approaches (application of prepared phantoms), the dynamic study of 2-[ 18 F]FDG uptake and transport within the excised leaf of tobacco or whole radish plant was carried out. The description of these processes was realized through the 3D PET images and through the quantification of 2-[ 18 F]FDG distribution within the chosen regions of interest from the point of view of accumulated 18 F radioactivity (in Bq) or amount of D-glucose (in μg) as well. Application of methods of multivariate analysis allows to found the similarities between studied objects mainly from the point

  5. Positron emission computerized tomography: a potential tool for in vivo quantitation of the distribution of radiopharmaceuticals

    International Nuclear Information System (INIS)

    Huebner, K.F.; King, P.; Gibbs, W.D.; Washburn, L.C.; Hayes, R.L.

    1981-01-01

    The principles and some of the difficulties in quantitative positron emission computerized tomography have been discussed. We have shown that randoms and scattered events are a major cause of noise and counting errors in positron emission computerized tomography. The noise has been identified as a convoluting process and a mathematical solution has been presented. Examples of phantom studies and in vivo measurements have demonstrated that the distribution of positron emitting radiopharmaceuticals can be quantitated with much improved accuracy using the deconvolution equation to remove undesired noise

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

    International Nuclear Information System (INIS)

    Blomqvist, G.; Lammertsma, A.A.; Mazoyer, B.; Wienhard, K.

    1995-01-01

    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 glc in the case of glucose analogs) was found to be comparatively insensitive to tissue heterogeneity. Individual rate constans such as k 2 and k 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 on .B 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 max was found to be insensitive while K d was very sensitive to tissue heterogeneity. (orig.)

  7. Cerebral glucose metabolism on positron emission tomography of children.

    Science.gov (United States)

    Shan, Zuyao Y; Leiker, Andrew J; Onar-Thomas, Arzu; Li, Yimei; Feng, Tianshu; Reddick, Wilburn E; Reutens, David C; Shulkin, Barry L

    2014-05-01

    Establishing the normative range of age-dependent fluorodeoxyglucose (FDG) uptake in the developing brain is necessary for understanding regional quantitative analysis of positron emission tomography (PET) brain images in children and also to provide functional information on brain development. We analyzed head sections of FDG PET/computed tomography (CT) images for 115 patients (5 months to 23 years) without central nervous system disease before treatment, as PET studies are not performed on healthy children owing to ethical considerations and the risk of radiation exposure. We investigated the changes in FDG uptake and established age-associated normative ranges of cerebral FDG. Head sections of FDG PET/CT images were registered to a population-based probabilistic atlas of human cortical structures. Gray matter of 56 brain structures was defined on normalized PET images according to the atlas. To avoid individual and experimental confounding factors, the relative standardized uptake value (SUV) over the cerebellum of each structure was calculated. Relative SUVs were analyzed by ANOVA and modeled using generalized estimating equalization analysis with false discovery rate control. Age and structure were significant factors affecting SUVs. Anatomic proximity had little effect on FDG uptake. Linear and quadratic developmental trajectories were observed on absolute and relative SUVs, respectively. An increase from posterior-to-anterior and superior-to-inferior pattern was observed in both absolute SUV increase rate and relative SUV peak age. The SUV of each structure was modeled with respect to age, and these models can serve as baselines for the quantitative analysis of cerebral FDG-PET images of children. Copyright © 2013 Wiley Periodicals, Inc.

  8. [Positron emission tomography/computed tomography for lung cancer staging].

    Science.gov (United States)

    Ladrón de Guevara H, David; Furnaro L, Francisca; Yévenes A, Sebastián; Clavero R, José Miguel; Lazo P, David; Rodríguez D, Patricio; Piottante B, Antonio; Pefaur D, Raúl; Pardo B, Claudio

    2015-01-01

    PET/CT (Positron Emission Tomography/Computed Tomography) is widely used in nodal and metastatic staging of lung cancer patients. To analyze PET/CT detection of metastatic disease in patients with lung cancer. We reviewed retrospectively F18Fluorodeoxyglucose PET/CT scans performed between December 2008 and December 2013. We selected 143 patients aged 30 to 92 years (63% males) with confirmed lung cancer referred for staging, with no previous treatment. We reviewed whole body PET/CT and brain magnetic resonance images. SUVmax (Standardized Uptake Value maximum) of primary pulmonary lesion, hilar/mediastinal nodes, and distant metastases were calculated. Histological types encountered were adenocarcinoma in 55%, squamous-cell in 15%, small-cell in 8%, large-cell in 6% and adeno-squamous in 2%. In 22 cases (15%) histology was not available. Nodal involvement was observed in 60% of patients (44% hilar and 48% mediastinal). Skip metastases (mediastinal involvement without hilum involvement) were encountered in 17% of cases, and were significantly more common among high uptake lung tumors (p < 0.01). Best SUVmax cut-off for node involvement was 4.4 for hilum and 4.0 for mediastinum (sensibility: 86.4%, specificity: 99.8%). Sixty six patients (46.2%) showed distant metastases on PET/CT. The most common metastases were osseous in 22%, adrenal in 16%, hepatic in14%, pulmonary in 14% and cerebral in 12%. PET/CT detected a second unexpected synchronic cancer in eight patients (6%). PET/CT is accurate for nodal staging using an uptake index as SUVmax. Distant metastases are common, especially in bone, adrenal glands and liver.

  9. Fluorodeoxyglucose positron emission tomography in pulmonary carcinoid tumors

    International Nuclear Information System (INIS)

    Gasparri, R.; Rezende, G. C.; Brambilla, D.; Petrella, F.; Galetta, D.; Spaggiari, L.; Fazio, N.; Maisonneuve, P.; Travaini, L. L.; Paganelli, G.

    2015-01-01

    The role of fluorodeoxyglucose positron emission tomography (FDG-PET) as an additional investigation to computer tomography for pulmonary carcinoid tumors remains controversial. The aim of this study was to assess the role of FDG-PET for the diagnosis and staging of pulmonary carcinoid tumors. It has been performed a retrospective mono-institutional analysis of data from 97 patients with pathologically confirmed pulmonary carcinoid tumor who had been operated on between July 1998 and April 2009 and had had a preoperative FDG-PET scan performed. Sixty-five (67%) of the 97 tumors were typical (TC) and 32 (33%) atypical (AC) carcinoid tumors. Overall FDG-PET sensitivity was 67% being lower for TC (60%) than for AC (81%) (P=0.04). FDG-PET negative tumors were smaller than FDG-PET positive tumors, with a respective median size of 15 and 17 mm (P=0.02). Median SUVmax for FDG-PET-positive tumors was 4.0 (2.8-5.1) with no difference between TC and AC tumors. Median Ki-67 expression was respectively 4.7% and 3.1% for FDG-PET positive and FDG-PET negative tumors (P=0.05). During a median follow-up of 49 months (interquartile range 30-63 months), 9 patients (4TC, 5AC) developed recurrent disease. Neither SUVmax nor Ki-67 expression resulted associated with disease-free survival. With an overall sensitivity of 67%, FDG-PET has shown to be useful in the preoperative work-up of patients with suspect lung carcinoid tumors. In particular it could have a role in larger tumors. These results warrant a prospective evaluation of FDG-PET in the staging of lung carcinoid tumor.

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

    International Nuclear Information System (INIS)

    Smith, Mark F.; Majewski, Stan; Weisenberger, Andrew G.; Kieper, Douglas A.; Raylman, Raymond R.; Turkington, Timothy G.

    2001-01-01

    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

  11. Nonhuman primate positron emission tomography neuroimaging in drug abuse research.

    Science.gov (United States)

    Howell, Leonard Lee; Murnane, Kevin Sean

    2011-05-01

    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 characterized in vivo drug interactions with specific protein targets in the brain, including neurotransmitter receptors and transporters. In vivo determinations of cerebral blood flow and metabolism have localized brain circuits implicated in the effects of abused drugs and drug-associated stimuli. Moreover, determinations of the predisposing factors to chronic drug use and long-term neurobiological consequences of chronic drug use, such as potential neurotoxicity, have led to novel insights regarding the pathology and treatment of drug addiction. However, similar approaches clearly need to be extended to drug classes other than stimulants. Although dopaminergic systems have been extensively studied, other neurotransmitter systems known to play a critical role in the pharmacological effects of abused drugs have been largely ignored in nonhuman primate PET neuroimaging. Finally, the study of brain activation with PET neuroimaging has been replaced in humans mostly by functional magnetic resonance imaging (fMRI). There has been some success in implementing pharmacological fMRI in awake nonhuman primates. Nevertheless, the unique versatility of PET imaging will continue to complement the systems-level strengths of fMRI, especially in the context of nonhuman primate drug abuse research.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mark F. Smith; Stan Majewski; Andrew G. Weisenberger; Douglas A. Kieper; Raymond R. Raylman; Timothy G. Turkington

    2001-11-01

    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.

  13. Positron Emission Mammography for Breast Cancer in Rajavithi Hospital.

    Science.gov (United States)

    Boonyaleepan, Araya

    2016-02-01

    Positron Emission Mammography (PEM) is a new modality in the investigation of breast cancer in Rajavithi Hospital, and its effectiveness has not yet been evaluated. To study the effectiveness and characterization of breast images taken with PEM in Rajavithi Hospital. This was a retrospective study in which data were collected and analyzed of patients who were investigated by PEM in Rajavithi Hospital between 18 September 2013 and 31 May 2014. Lesion to background (LTB) ratio of >_2. 0 with focal localization was considered to be suggestive of PEM positive for malignancy. Twenty-three female patients were included in the study, and their mean age was 51.7 years. Mean fasting blood glucose (FBS) was 93.64 mg/dl, and mean Fluorodeoxyglucose (FDG) injected dose was 7.76 mCi. The average PUV mean of background of both breasts decreased with advancing age. Fourteen patients were pathologically diagnosed with a total of lesions, of which 12 were malignant and four were benign. The positive predictive value (PPV) was 76.92%, and the mean LTB of true positive lesions was 5.31. Three false positive lesions were found: one mild atypical cell, one papilloma and one fibroadenoma, and the mean LTB was 2.92. The two false negative lesions were both DCIS. There was a moderate PPV in this PEM study for breast cancer in Rajavithi Hospital, and investigators need further experience and training in interpreting PEM. The information of mammographic, ultrasonographic and clinical findings should be used together with PEM to make diagnostic decision. The addition of biopsies could also improve the efficacy of PEM studies.

  14. Low-energy positron and electron diffraction and positron-stimulated secondary electron emission from Cu(100)

    International Nuclear Information System (INIS)

    Weiss, A.H.

    1983-01-01

    The results of two series of experiments are reported. In the first, an electrostatically guided beam of low-energy (40-400 eV) positrons, delta/sub p/ was used to study low-energy positron diffraction (LEPD) from a Cu(100) surface under ultrahigh-vacuum conditions. Low-energy electron diffraction (LEED) data were obtained from the same sample in the same apparatus. Comparison of LEPD and LEED intensity versus energy data with model calculations made using computer programs developed by C.B. Duke and collaborators indicated that: LEPD data is adequately modeled using potentials with no exchange-correlation term. The inelastic mean free path, lambda/sub ee/, is shorter for positrons than for electrons at low (< approx.80 eV). LEED is better than LEPD at making a determination of the first-layer spacing of Cu(100) for the particular data set reported. In the second set of experiments, the same apparatus and sample were used to compare positron- and electron-stimulated secondary-electron emission (PSSEE and ESSEE). The results were found to be consistent with existing models of secondary-electron production for metals. The energy distributions of secondary-electrons had broad low-energy (<10 eV) peaks for both positron and electron stimulation. But the PSEE distribution showed no elastic peak. Measurements of secondary-electron angular distributions, found to be cosine-like in both the PSSEE and ESSEE case, were used to obtain total secondary yield ratios, delta, at four beam energies ranging from 40-400 eV. The secondary yield ratio for primary positrons and the yield for primary electrons, delta/sub e/, were similar at these energies. For 400-eV primary particles the secondary yields were found to be delta/sub p/ = 0.94 +/- 0.12 and delta/sub e/ = 0.94 +/- 0./12, giving a ratio of unity for positron-stimulated secondary yield to electron-stimulated secondary yield

  15. 76 FR 54473 - Guidance on Positron Emission Tomography Drug Applications-Content and Format for New Drug...

    Science.gov (United States)

    2011-09-01

    ... (formerly Docket No. 00D-0892)] Guidance on Positron Emission Tomography Drug Applications-- Content and... NDAs and ANDAs.'' This document is intended to assist manufacturers of certain positron emission... Emission Tomography Drug Products,'' issued on March 10, 2000 (65 FR 13010). The February 3, 2011, revised...

  16. Positron Emission Tomography Imaging Using Radiolabeled Inorganic Nanomaterials

    Science.gov (United States)

    Sun, Xiaolian; Cai, Weibo; Chen, Xiaoyuan

    2015-01-01

    CONSPECTUS Positron emission tomography (PET) is a radionuclide imaging technology that plays an important role in preclinical and clinical research. With administration of a small amount of radiotracer, PET imaging can provide a noninvasive, highly sensitive, and quantitative readout of its organ/tissue targeting efficiency and pharmacokinetics. Various radiotracers have been designed to target specific molecular events. Compared with antibodies, proteins, peptides, and other biologically relevant molecules, nanoparticles represent a new frontier in molecular imaging probe design, enabling the attachment of different imaging modalities, targeting ligands, and therapeutic payloads in a single vector. We introduce the radiolabeled nanoparticle platforms that we and others have developed. Due to the fundamental differences in the various nanoparticles and radioisotopes, most radiolabeling methods are designed case-by-case. We focus on some general rules about selecting appropriate isotopes for given types of nanoparticles, as well as adjusting the labeling strategies according to specific applications. We classified these radiolabeling methods into four categories: (1) complexation reaction of radiometal ions with chelators via coordination chemistry; (2) direct bombardment of nanoparticles via hadronic projectiles; (3) synthesis of nanoparticles using a mixture of radioactive and nonradioactive precursors; (4) chelator-free postsynthetic radiolabeling. Method 1 is generally applicable to different nanomaterials as long as the surface chemistry is well-designed. However, the addition of chelators brings concerns of possible changes to the physicochemical properties of nanomaterials and detachment of the radiometal. Methods 2 and 3 have improved radiochemical stability. The applications are, however, limited by the possible damage to the nanocomponent caused by the proton beams (method 2) and harsh synthetic conditions (method 3). Method 4 is still in its infancy

  17. Evaluation of esophageal cancer by positron emission tomography

    International Nuclear Information System (INIS)

    Himeno, Shinji; Yasuda, Seiei; Shimada, Hideo; Tajima, Tomoo; Makuuchi, Hiroyasu

    2002-01-01

    A retrospective study was performed to determine the indications for positron emission tomography (PET) using [ 18 F]fluorodeoxyglucose (FDG) in patients with esophageal cancer, including those with early cancer, and to investigate whether the tumor-to-normal ratio (T/N ratio) could be used as a substitute for the standardized uptake value (SUV). Thirty-six patients were included in the study. Thirty-one patients who had 36 biopsy-proven lesions (35 squamous cell carcinomas and one small cell carcinoma) underwent PET study prior to treatment. PET images were evaluated visually and the relationship between the depth of invasion and the PET findings were examined in 22 lesions of 19 patients from whom specimens were obtained from the primary tumor by surgery or endoscopic mucosal resection. PET results were also compared with computed tomography (CT) and endoscopic ultrasonography (EUS) for detection of regional lymph node metastases in 18 patients who underwent extended lymph node dissection. Five patients underwent PET studies for the detection of recurrence and the PET findings were compared with their CT findings. The T/N ratio and the SUV were calculated for 20 primary tumors. Among the 15 tumors that were pT1b or greater, all 15 were positive on PET and all seven of the lesions confined to the mucosa (Tis or T1a) were negative. The sensitivity, specificity and accuracy of detecting nodal involvement were, respectively, 37.5, 96.1 and 88.3% by CT, 30.8, 88.5 and 81.0% by EUS and 41.7, 100 and 92.2% by PET. More sites of recurrence were detected by PET than by CT. There was no statistically significant correlation between the SUV and the T/N ratio. PET imaging can detect primary esophageal cancer with a depth of invasion of T1b or greater, but Tis and T1a tumors are undetectable. PET seems to be more accurate than CT or EUS for diagnosing lymph node metastasis. The T/N ratio cannot be used as a substitute for the SUV. (author)

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

    International Nuclear Information System (INIS)

    Karim, Kamran Said

    2010-01-01

    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 LuPO 4 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

  19. Positron emission tomography of malignant tumours at head and neck. Evaluation of the diagnostic value of positron emission tomography by comparison with computed tomography

    International Nuclear Information System (INIS)

    Kettler, Nele

    2011-01-01

    Imaging methods for early, accurate diagnosis and aftercare of malignant growths is currently one of the most important research topics. The objective of this thesis is to evaluate the diagnostic value of FDG-positron emission tomography by comparison with computed tomography for patients with squamous cell carcinoma, malignant melanoma or sarcoma at head and neck. Measurement criteria are sensitivity and specificity. A retrospective evaluation of 100 examinations on 85 patients of University clinic Aachen was performed. The examination reports were supported by reports from histology, positron emission tomography and computed tomography. In each case, the histological results were assumed to provide a reliable benchmark. Sensitivity and specificity for the primary tumour site, metastatic lymphatic nodes and defined anatomic structures were compared across all patients. Comparisons were also performed on sub groups separated by gender, cancer type and the time and frequency at which tumours arose. The statistic analysis was done with MedCalc. Results: The results for sensitivity and specificity of the primary tumour site were 86.42% and 42.86%, and 64.71% and 66.07%, for positron emission tomography and computed tomography respectively. The results for the lymphatic nodes were 51.52% and 92.86% and 64.71% and 66.07%. When the constituent anatomic structures were evaluated separately, the specificity was significantly higher. The separation by gender showed no difference. Because the classification by tumor type resulted in samples that were of varying size, a comparison was difficult. For the diagnosis of primary tumours, the examination with positron emission tomography was superior, whereas computed tomography proved more effective for the diagnosis of recurrent tumours. For the diagnosis of the main tumour site, both methods were shown to be equally suitable. For the assessment of lymphatic nodes, positron emission tomography was superior to computed tomography

  20. Dynamic positron emission tomography for study of cerebral hemodynamics in a cross section of the head using positron-emitting 68Ga-EDTA and 77Kr

    International Nuclear Information System (INIS)

    Yamamoto, Y.L.; Thompson, C.J.; Meyer, E.; Robertson, J.S.; Feindel, W.

    1977-01-01

    Dynamic positron emission tomographic studies were performed on over 120 patients with occlusive cerebrovascular disease, arteriovenous malformations, and brain tumors, using the positron section scanner, consisting of a ring of 32 scintillation detectors. The radiopharmaceuticals were nondiffusible 68 Ga-EDTA for transit time and uptake studies and the diffusible tracer, 77 Kr, for quantitative regional cerebral blood flow studies in every square centimeter of the cross section of the head. The results of dynamic positron emission tomography in correlation with the results from the gamma scintillation camera dynamic studies and computed tomography (CT) scans are discussed

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

    International Nuclear Information System (INIS)

    Setty, B.; Blake, M.A.; Holalkere, N.S.; Blaszkowsky, L.S.; Fischman, A.

    2006-01-01

    Positron emission tomography/CT is an established imaging method in the diagnosis and staging of cancers. 18 F -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

  2. Homotopic non-local regularized reconstruction from sparse positron emission tomography measurements

    International Nuclear Information System (INIS)

    Wong, Alexander; Liu, Chenyi; Wang, Xiao Yu; Fieguth, Paul; Bie, Hongxia

    2015-01-01

    Positron emission tomography scanners collect measurements of a patient’s in vivo radiotracer distribution. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer), which is introduced into the body on a biologically active molecule, and the tomograms must be reconstructed from projections. The reconstruction of tomograms from the acquired PET data is an inverse problem that requires regularization. The use of tightly packed discrete detector rings, although improves signal-to-noise ratio, are often associated with high costs of positron emission tomography systems. Thus a sparse reconstruction, which would be capable of overcoming the noise effect while allowing for a reduced number of detectors, would have a great deal to offer. In this study, we introduce and investigate the potential of a homotopic non-local regularization reconstruction framework for effectively reconstructing positron emission tomograms from such sparse measurements. Results obtained using the proposed approach are compared with traditional filtered back-projection as well as expectation maximization reconstruction with total variation regularization. A new reconstruction method was developed for the purpose of improving the quality of positron emission tomography reconstruction from sparse measurements. We illustrate that promising reconstruction performance can be achieved for the proposed approach even at low sampling fractions, which allows for the use of significantly fewer detectors and have the potential to reduce scanner costs

  3. Positron emission tomography with f18-fluorodeoxyglucose in the staging and preoperative evaluation of malignant pleural mesothelioma.

    Science.gov (United States)

    Schneider, D B; Clary-Macy, C; Challa, S; Sasse, K C; Merrick, S H; Hawkins, R; Caputo, G; Jablons, D

    2000-07-01

    The purpose of this study was to evaluate the utility of positron emission tomography with F18-fluorodeoxyglucose in the preoperative evaluation and staging of malignant mesothelioma in patients who were candidates for aggressive combined modality therapy. Eighteen consecutive patients with biopsy-proven malignant mesothelioma underwent positron emission tomographic scanning. The results of positron emission tomographic imaging were compared with results obtained by computed tomography, mediastinoscopy, thoracoscopy, and pathologic examination of surgical specimens. All patients fasted and received an average of 14.5 +/- 2.7 mCi of F18-fluorodeoxyglucose for positron emission tomographic scanning. Attenuation-corrected whole-body and regional emission images of the chest and upper abdomen were acquired and formatted into transaxial, coronal, and sagittal images. All primary malignant mesotheliomas accumulated F18-fluorodeoxyglucose, and the mean standardized uptake value was 7. 6 (range, 3.33-14.85; n = 9). There were no false-negative results of positron emission tomography. Identification of occult extrathoracic metastases by positron emission tomography was the basis for excluding two patients from surgical therapy. There were two false-positive results of positron emission tomography: increased F18-fluorodeoxyglucose uptake in the contralateral chest that was negative by thoracoscopic biopsy (n = 1) and increased abdominal F18-fluorodeoxyglucose uptake after partial colectomy for diverticular disease (n = 1). Positron emission tomography can identify malignant pleural mesothelioma and appears to be a useful noninvasive staging modality for patients being considered for aggressive combined modality therapy.

  4. Defining a radiotherapy target with positron emission tomography

    International Nuclear Information System (INIS)

    Black, Quinten C.; Grills, Inga S.; Kestin, Larry L.; Wong, Ching-Yee O.; Wong, John W.; Martinez, Alvaro A.; Yan Di

    2004-01-01

    Purpose: F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is now considered the most accurate clinical staging study for non-small-cell lung cancer (NSCLC) and is also important in the staging of multiple other malignancies. Gross tumor volume (GTV) definition for radiotherapy, however, is typically based entirely on computed tomographic data. We performed a series of phantom studies to determine an accurate and uniformly applicable method for defining a GTV with FDG-PET. Methods and materials: A model-based method was tested by a phantom study to determine a threshold, or unique cutoff of standardized uptake value based on body weight (standardized uptake value [SUV]) for FDG-PET based GTV definition. The degree to which mean target SUV, background FDG concentration, and target volume influenced that GTV definition were evaluated. A phantom was constructed consisting of a 9.0-L cylindrical tank. Glass spheres with volumes ranging from 12.2 to 291.0 cc were suspended within the tank, with a minimum separation of 4 cm between the edges of the spheres. The sphere volumes were selected based on the range of NSCLC patient tumor volumes seen in our clinic. The tank and spheres were filled with a variety of known concentrations of FDG in several experiments and then scanned using a General Electric Advance PET scanner. In the initial experiment, six spheres with identical volumes were filled with varying concentrations of FDG (mean SUV 1.85 ∼ 9.68) and suspended within a background bath of FDG at a similar concentration to that used in clinical practice (0.144 μCi/mL). The second experiment was identical to the first, but was performed at 0.144 and 0.036 μCi/mL background concentrations to determine the effect of background FDG concentration on sphere definition. In the third experiment, six spheres with volumes of 12.2 to 291.0 cc were filled with equal concentrations of FDG and suspended in a standard background FDG concentration of 0.144

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    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. (authors)

  6. Role and impact of [18F]-fluorodeoxyglucose positron emission tomography in recurrent breast cancer

    International Nuclear Information System (INIS)

    Grahek, D.; Montravers, F.; Aide, N.; Kerrou, K.; Talbot, J.N.

    2004-01-01

    [18F]-fluorodeoxyglucose positron emission tomography is widely used in oncology to detect malignant tissue, assess the extent of the disease and follow up treatment. In breast cancer, recurrence detection seems to be the leading indication of [18F] fluorodeoxyglucose positron emission tomography. This review, including recent publications, aims to evaluate its role to detect the recurrent malignant. tissue when tumour marker levels are isolatedly rising and to evaluate the extent of-the disease. The first impact studies reveal its important role in the management of the patients suspected of breast cancer recurrence. (author)

  7. Regional cerebral glucose metabolism during sevoflurane anaesthesia in healthy subjects studied with positron emission tomography

    DEFF Research Database (Denmark)

    Schlünzen, L; Juul, N; Hansen, K V

    2010-01-01

    BACKGROUND: The precise mechanism by which sevoflurane exerts its effects in the human brain remains unknown. In the present study, we quantified the effects of sevoflurane on regional cerebral glucose metabolism (rGMR) in the human brain measured with positron emission tomography. METHODS: Eight...... volunteers underwent two dynamic 18F-fluorodeoxyglucose positron emission tomography (PET) scans. One scan assessed conscious-baseline metabolism and the other scan assessed metabolism during 1 minimum alveolar concentration (MAC) sevoflurane anaesthesia. Cardiovascular and respiratory parameters were...... areas by 48-71% of the baseline (Pmetabolic reduction of GMR in all regions...

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

    Directory of Open Access Journals (Sweden)

    Mohsen Mashayekhi

    2015-05-01

    Full Text Available 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 were performed for the soft tissue phantom (8 mm ×8 mm × 8 mm. Positrons were emitted isotropically from the center of the phantom. By the application of a magnetic field perpendicular to the path of positrons, lateral scattering of positrons could be prevented due to Lorentz force. When the positron energy was below the cut-off threshold (0.001 MeV, the simulation was terminated. Results The findings showed that the presence of a magnetic field increased the rate of positron annihilation. At magnetic field strengths of 3, 7, and 10 Tesla, 18F with the lowest decay energy showed improvements in the ratio of full width at half maximum (FWHM resolution to the peak of curve by 3.64%, 3.89%, and 5.96%, respectively. In addition, at magnetic field strengths of 3, 7 and 10 Tesla, 82Rb with the highest decay energy showed improvements in resolution by 33%, 85%, and 99%, respectively. Conclusion Application of a magnetic field perpendicular to the positron diffusion plane prevented the scattering of positrons, and consequently, improved the intrinsic spatial resolution of PET imaging, caused by positron range effects.

  9. Use of positron emission tomography (PET) for the diagnosis of large-vessel vasculitis.

    Science.gov (United States)

    Loricera, J; Blanco, R; Hernández, J L; Martínez-Rodríguez, I; Carril, J M; Lavado, C; Jiménez, M; González-Vela, C; González-Gay, M Á

    2015-01-01

    The term vasculitis encompasses a heterogeneous group of diseases that share the presence of inflammatory infiltrates in the vascular wall. The diagnosis of large-vessel vasculitis is often a challenge because the presenting clinical features are nonspecific in many cases and they are often shared by different types of autoimmune and inflammatory diseases including other systemic vasculitides. Moreover, the pathogenesis of large-vessel vasculitis is not fully understood. Nevertheless, the advent of new imaging techniques has constituted a major breakthrough to establish an early diagnosis and a promising tool to monitor the follow-up of patients with largevessel vasculitis. This is the case of the molecular imaging with the combination of positron emission tomography with computed tomography (PET/CT) using different radiotracers, especially the (18)F-fluordeoxyglucose ((18)F-FDG). In this review we have focused on the contribution of (18)F-FDG PET in the diagnosis of large-vessel vasculitis. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  10. 2-18F-fluoro-2-deoxyglucose positron emission tomography in delirium.

    Science.gov (United States)

    Haggstrom, Lucy R; Nelson, Julia A; Wegner, Eva A; Caplan, Gideon A

    2017-11-01

    Delirium is a common, serious, yet poorly understood syndrome. Growing evidence suggests cerebral metabolism is fundamentally disturbed; however, it has not been investigated using 2- 18 F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in delirium. This prospective study thus explored FDG PET patterns of cerebral glucose metabolism in older inpatients with delirium. A particular emphasis was on the posterior cingulate cortex (PCC), a key region for attention, which is a central feature of delirium. Delirium scans were compared with post-delirium scans using visual analysis and semi-quantitative analysis with NeuroQ; 13 participants (8 female, median 84 y) were scanned during delirium, and 6 scanned again after resolution. On visual analysis, cortical hypometabolism was evident in all participants during delirium (13/13), and improved with delirium resolution (6/6). Using NeuroQ, glucose metabolism was higher post-delirium in the whole brain and bilateral PCC compared to during delirium ( p delirium duration. This research found widespread, reversible cortical hypometabolism during delirium and PCC hypometabolism was associated with inattention during delirium.

  11. Fluorodeoxyglucose and C-Choline positron emission tomography for distinction of metastatic plexopathy and neuritis : a case report

    NARCIS (Netherlands)

    Bartels, Anna L.; Zeebregts, Clark J; Enting, Roeline; Slart, Riemer Hja

    2009-01-01

    INTRODUCTION: Fluorodeoxyglucose positron emission tomography scanning has an established role in the diagnostic work-up of many malignant diseases and also in the evaluation of cancer treatment response. Fluorodeoxyglucose positron emission tomography may, however be non-specific as infectious

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

    International Nuclear Information System (INIS)

    Pellat, J.; Hommel, M.

    1987-01-01

    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 [fr

  13. Intrinsic spatial resolution limitations due to differences between positron emission position and annihilation detection localization

    International Nuclear Information System (INIS)

    Perez, Pedro; Malano, Francisco; Valente, Mauro

    2012-01-01

    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)

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

    International Nuclear Information System (INIS)

    Lopez D, F.A.

    2005-01-01

    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)

  15. 76 FR 47593 - Guidance for Small Business Entities on Current Good Manufacturing Practice for Positron Emission...

    Science.gov (United States)

    2011-08-05

    ... prepared this guidance in accordance with the Small Business Regulatory Enforcement Fairness Act. It is...] Guidance for Small Business Entities on Current Good Manufacturing Practice for Positron Emission... and Drug Administration (FDA) is announcing the availability of a guidance for small business entities...

  16. 18F-fluorodeoxyglucose positron emission tomography predicts survival of patients with neuroendocrine tumors

    DEFF Research Database (Denmark)

    Binderup, Tina; Knigge, Ulrich; Loft, Annika

    2010-01-01

    PURPOSE: (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) is currently not used on a routine basis for imaging of neuroendocrine (NE) tumors. The aim of this study was to investigate the prognostic value of FDG-PET in patients with NE tumors. EXPERIMENTAL DESIGN: Ninety...

  17. 77 FR 71803 - Guidance on Food and Drug Administration Oversight of Positron Emission Tomography Drug Products...

    Science.gov (United States)

    2012-12-04

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-D-0080] Guidance on Food and Drug Administration Oversight of Positron Emission Tomography Drug Products--Questions and Answers; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food...

  18. Positron emission tomography in the diagnosis and staging of lung cancer

    DEFF Research Database (Denmark)

    Fischer, B M; Mortensen, J; Højgaard, L

    2001-01-01

    positron emission tomography (PET) and gamma-camera PET in the diagnostic investigation of non-small-cell lung cancer (NSCLC). A systematic literature search was carried out in the MEDLINE and EMBASE databases and the Cochrane Controlled Trials Register. We identified 55 original works on the diagnostic...

  19. 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

    , 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...

  20. Hypoxia positron emission tomography imaging: combining information on perfusion and tracer retention to improve hypoxia specificity

    DEFF Research Database (Denmark)

    Busk, Morten; Munk, Ole L; Jakobsen, Steen S

    2017-01-01

    BACKGROUND: Static positron emission tomography (PET) allows mapping of tumor hypoxia, but low resolution and slow tracer retention/clearance results in poor image contrast and the risk of missing areas where hypoxic cells and necrosis are intermixed. Fully dynamic PET may improve accuracy but scan...

  1. Monitoring variables affecting positron emission tomography measurements of cerebral blood flow in anaesthetized pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Zois, Nora Elisabeth; Simonsen, Mette

    2018-01-01

    Background Positron emission tomography (PET) imaging of anaesthetized pig brains is a useful tool in neuroscience. Stable cerebral blood flow (CBF) is essential for PET, since variations can affect the distribution of several radiotracers. However, the effect of physiological factors regulating...

  2. 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 PET...

  3. A New Positron Emission Tomography (PET) Radioligand for Imaging Sigma-1 Receptors in Living Subjects

    DEFF Research Database (Denmark)

    James, Michelle L; Shen, Bin; Zavaleta, Cristina L

    2012-01-01

    ]13 was synthesized by nucleophilic fluorination, affording a product with >99% radiochemical purity (RCP) and specific activity (SA) of 2.6 ± 1.2 Ci/µmol (n = 13) at end of synthesis (EOS). Positron emission tomography (PET) and ex vivo autoradiography studies of [(18)F]13 in mice showed high uptake...

  4. Monitoring variables affecting positron emission tomography measurements of cerebral blood flow in anaesthetized pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Zois, Nora Elisabeth; Simonsen, Mette

    Background: Positron emission tomography (PET) imaging of anaesthetised pig brains is a useful tool in neuroscience. Stable cerebral blood flow (CBF) is essential for PET, since variations can affect the kinetics of several radiotracers. However, the impact of physiological factors regulating CBF...

  5. Statistical properties of compartmental model parameters extracted from dynamic positron emission tomography experiments

    International Nuclear Information System (INIS)

    Mazoyer, B.M.; Huesman, R.H.; Budinger, T.F.; Knittel, B.L.

    1986-01-01

    Over the past years a major focus of research in physiologic studies employing tracers has been the computer implementation of mathematical methods of kinetic modeling for extracting the desired physiological parameters from tomographically derived data. A study is reported of factors that affect the statistical properties of compartmental model parameters extracted from dynamic positron emission tomography (PET) experiments

  6. A positron emission tomography study of wind-up pain in chronic postherniotomy pain

    DEFF Research Database (Denmark)

    Kupers, Ron; Lonsdale, Markus Georg; Aasvang, Eske Kvanner

    2011-01-01

    -induced wind-up pain in neuropathic pain patients. We therefore used positron emission tomography (PET) to investigate the cerebral response pattern of mechanical wind-up pain in a homogenous group of 10 neuropathic pain patients with long-standing postherniotomy pain in the groin area. Patients were scanned...

  7. Positron emission tomography in the follow-up of cutaneous malignant melanoma patients

    DEFF Research Database (Denmark)

    Danielsen, Maria; Højgaard, Liselotte; Kjær, Andreas

    2014-01-01

    node involvement and distant metastases, accentuating the importance of close surveillance to identify disease progression at an early stage, and thereby detect recurrences amenable to treatment. Positron emission tomography (PET) has already been proven useful in the staging of CMM, but the utility...

  8. Early positron emission tomography response-adapted treatment in stage I and II hodgkin lymphoma

    DEFF Research Database (Denmark)

    André, Marc P.E.; Girinsky, Théodore; Federico, Massimo

    2017-01-01

    Purpose Patients who receive combined modality treatment for stage I and II Hodgkin lymphoma (HL) have an excellent outcome. Early response evaluation with positron emission tomography (PET) scan may improve selection of patients who need reduced or more intensive treatments. Methods We performed...

  9. 77 FR 11553 - Draft Guidance on Food and Drug Administration Oversight of Positron Emission Tomography Drug...

    Science.gov (United States)

    2012-02-27

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-D-0080] Draft Guidance on Food and Drug Administration Oversight of Positron Emission Tomography Drug Products--Questions and Answers; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The...

  10. 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....

  11. Characterization of hepatic tumors using [11C]metomidate through positron emission tomography

    DEFF Research Database (Denmark)

    Roivainen, Anne; Naum, Alexandru; Nuutinen, Heikki

    2013-01-01

    ABSTRACT: BACKGROUND: Using positron emission tomography (PET), we compared two tracers, [11C]metomidate ([11C]MTO) and [11C]acetate ([11C]ACE), for the characterization of hepatic tumors. METHODS: Thirty-three patients underwent PET with [11C]MTO and [11C]ACE and magnetic resonance imaging (MRI...

  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...

  13. Cobalt-55 positron emission tomography in traumatic brain injury : A pilot study

    NARCIS (Netherlands)

    Jansen, HML; vanderNaalt, J; vanZomeren, AH; Paans, AMJ; VeenmavanderDuin, L; Hew, JM; Pruim, J; Minderhoud, JM; Korf, J

    Traumatic brain injury is usually assessed with the Glasgow coma scale (GCS), CT, or MRI. After such injury, the injured brain tissue is characterised by calcium mediated neuronal damage and inflammation. Positron emission tomography with the isotope cobalt-55 (Go-PET) as a calcium tracer enables

  14. Activity-based costing evaluation of a [F-18]-fludeoxyglucose positron emission tomography study

    NARCIS (Netherlands)

    Krug, Bruno; Van Zanten, Annie; Pirson, Anne-Sophie; Crott, Ralph; Vander Borght, Thierry

    2009-01-01

    Objective: The aim of the study is to use the activity-based costing approach to give a better insight in the actual cost structure of a positron emission tomography procedure (FDG-PET) by defining the constituting components and by simulating the impact of possible resource or practice changes.

  15. 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...

  16. Ischemic patterns assessed by positron emission tomography predict adverse outcome in patients with idiopathic dilated cardiomyopathy

    NARCIS (Netherlands)

    de Jong, Richard M.; Tio, Rene A.; van der Harst, Pim; Voors, Adriaan A.; Koning, Paul M.; Zeebregts, Clark J. A. M.; van Veldhuisen, Dirk J.; Dierckx, Rudi A. J. O.; Slart, Riemer H. J. A.

    2009-01-01

    Although patients with idiopathic dilated cardiomyopathy (DCM) have no coronary artery disease, regional impairment of myocardial perfusion combined with preserved metabolism has been found using positron emission tomography (PET). Our aim was to assess the prognostic relevance of PET-mismatch

  17. In vitro imaging of bacteria using (18)F-fluorodeoxyglucose micro positron emission tomography

    NARCIS (Netherlands)

    Heuker, Marjolein; Sijbesma, Jürgen W A; Suárez, Rocío Aguilar; de Jong, Johan R; Boersma, Hendrikus H; Luurtsema, Gert; Elsinga, Philip H; Glaudemans, Andor W J M; van Dam, Gooitzen M; van Dijl, Jan Maarten; Slart, Riemer H J A; van Oosten, Marleen

    2017-01-01

    Positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose ((18)F-FDG) can be applied to detect infection and inflammation. However, it was so far not known to what extent bacterial pathogens may contribute to the PET signal. Therefore, we investigated whether clinical isolates of

  18. In vitro imaging of bacteria using 18F-fluorodeoxyglucose micro positron emission tomography

    NARCIS (Netherlands)

    Heuker, Marjolein; Sijbesma, Jürgen W.A.; Suárez, Rocío Aguilar; De Jong, Johan R.; Boersma, Hendrikus H.; Luurtsema, Gert; Elsinga, Philip H.; Glaudemans, Andor W.J.M.; Van Dam, Gooitzen M.; Van Dijl, Jan Maarten; Slart, Riemer H.J.A.; Van Oosten, Marleen

    2017-01-01

    Positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose (18F-FDG) can be applied to detect infection and inflammation. However, it was so far not known to what extent bacterial pathogens may contribute to the PET signal. Therefore, we investigated whether clinical isolates of

  19. Characterization of positron emission tomography hypoxia tracer uptake and tissue oxygenation via electrochemical modeling

    NARCIS (Netherlands)

    Bowen, S.R.; Kogel, A.J. van der; Nordsmark, M.; Bentzen, S.M.; Jeraj, R.

    2011-01-01

    PURPOSE: Unique uptake and retention mechanisms of positron emission tomography (PET) hypoxia tracers make in vivo comparison between them challenging. Differences in imaged uptake of two common hypoxia radiotracers, [(61)Cu]Cu-ATSM and [(18)F]FMISO, were characterized via computational modeling to

  20. Fluorodeoxyglucose-based positron emission tomography imaging to monitor drug responses in hematological tumors

    NARCIS (Netherlands)

    Newbold, Andrea; Martin, Ben P.; Cullinane, Carleen; Bots, Michael

    2014-01-01

    Positron emission tomography (PET) can be used to monitor the uptake of the labeled glucose analog fluorodeoxyglucose (¹⁸F-FDG), a process that is generally believed to reflect viable tumor cell mass. The use of ¹⁸F-FDG PET can be helpful in documenting over time the reduction in tumor mass volume

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

    International Nuclear Information System (INIS)

    Zade, Anand; Ahire, Archana; Shetty, Shishir; Rai, Sujith; Bokka, Rajashekharrao; Velumani, Arokiaswamy; Kabnurkar, Rasika

    2015-01-01

    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

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

    International Nuclear Information System (INIS)

    Gundacker, S.

    2014-01-01

    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

  3. 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.

  4. The potential application of silver and positron emission tomography for in vivo dosimetry during radiotherapy

    DEFF Research Database (Denmark)

    Hansen, Anders T; Hansen, Søren B; Petersen, Jørgen B

    2007-01-01

    The possible use of silver as a material for in vivo dosimetry in radiotherapy was investigated. The investigation was carried out using a positron emission tomography (PET) scanner, two clinical accelerators and a phantom with silver implants. The phantom was irradiated several times to doses...... between 6 and 45 Gy. The resulting activity of positron-emitting isotopes produced in the silver by photonuclear processes was measured. It was found that the two therapeutic beams with energies of 15 MV and 18 MV would produce approximately 8344 and 7013 atoms of the radioactive isotope (106)Ag per Gy...

  5. Positron emission tomography of hepatic first-pass metabolism of ammonia in pig

    DEFF Research Database (Denmark)

    Keiding, S; Munk, O L; Roelsgaard, K

    2001-01-01

    Hepatic first-pass metabolism plays a key role in metabolic regulation and drug metabolism. Metabolic processes can be quantified in vivo by positron emission tomography scanning (PET). We wished to develop a PET technique to measure hepatic first-pass metabolism of ammonia. Seven anaesthetised...... pigs were given positron-labelled ammonia, (13)NH(3), into the portal vein and into the vena cava as successive 2-min infusions followed by 22-min dynamic liver scanning. Vena cava infusion data were used to account for recirculation of tracer and metabolites following the portal vein infusion...

  6. Positron emission intensities in the decay of 64Cu, 76Br and 124I

    International Nuclear Information System (INIS)

    Qaim, S.M.; Bisinger, T.; Hilgers, K.; Nayak, D.; Coenen, H.H.

    2007-01-01

    The relatively long-lived positron emitters 64 Cu (t 1/2 = 12.7 h), 76 Br (t 1/2 = 16.2 h) and 124 I (t 1/2 = 4.18 d) are finding increasing applications in positron emission tomography (PET). For precise determination of their positron emission intensities, each radionuclide was prepared via a charged particle induced reaction in a ''no-carrier-added'' form and with high radionuclidic purity. It was then subjected to γ-ray and X-ray spectroscopy as well as to anticoincidence beta and γγ-coincidence counting. The positron emission intensities measured were: 64 Cu (17.8 ± 0.4)%, 76 Br (58.2 ± 1.9)% and 124 I (22.0 ± 0.5)%. The intensity of the weak 1346 keV γ-ray emitted in the decay of 64 Cu was determined as (0.54 ± 0.03)%. Some implications of the precisely determined nuclear data are discussed. (orig.)

  7. Positron Emission Tomography: Current Challenges and Opportunities for Technological Advances in Clinical and Preclinical Imaging Systems

    Science.gov (United States)

    Vaquero, Juan José; Kinahan, Paul

    2017-01-01

    Positron emission tomography (PET) imaging is based on detecting two time-coincident high-energy photons from the emission of a positron-emitting radioisotope. The physics of the emission, and the detection of the coincident photons, give PET imaging unique capabilities for both very high sensitivity and accurate estimation of the in vivo concentration of the radiotracer. PET imaging has been widely adopted as an important clinical modality for oncological, cardiovascular, and neurological applications. PET imaging has also become an important tool in preclinical studies, particularly for investigating murine models of disease and other small-animal models. However, there are several challenges to using PET imaging systems. These include the fundamental trade-offs between resolution and noise, the quantitative accuracy of the measurements, and integration with X-ray computed tomography and magnetic resonance imaging. In this article, we review how researchers and industry are addressing these challenges. PMID:26643024

  8. Emission tomography with positrons principle, physical performances of a ring detector and quantitative possibilities

    International Nuclear Information System (INIS)

    Soussaline, F.; Plummer, D.; Todd Pokropek, A.E.; Loc'h, C.; Comar, D.

    1979-01-01

    Satisfactory qualitative and quantitative data in positron emission tomography requires the use of a well adapted tomographic system. A number of parameters have been identified which can be considered as the critical characteristics for evaluation and intercomparison of such systems. Using these the choice of a single slice ring positron camera could be justified by its physical performance, which is presented and discussed. Series of physical and mathematical simulations allow an appropriate knowledge of such a system, which has been in use for more than a year in a clinical environment. These studies aid to the interpretation of very interesting physiopathologic studies. In principle, a positron tomographic system permits measurement of absolute quantitative concentration values, which are essential for precise metabolic studies. The main sources of error comprising the calibration of the system, the tail effects and the precision for attenuation correction are analysed. When taking in account these errors, a precision of the order of 10% should be obtainable [fr

  9. Bitemporal hypometabolism in Creutzfeldt-Jakob disease measured by positron emission tomography with [18F]-2-fluorodeoxyglucose

    International Nuclear Information System (INIS)

    Friedland, R.P.; Prusiner, S.B.; Jagust, W.J.; Budinger, T.F.; Davis, R.L.

    1984-01-01

    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

  10. Bitemporal hypometabolism in Creutzfeldt-Jakob disease measured by positron emission tomography with (/sup 18/F)-2-fluorodeoxyglucose

    Energy Technology Data Exchange (ETDEWEB)

    Friedland, R.P.; Prusiner, S.B.; Jagust, W.J.; Budinger, T.F.; Davis, R.L.

    1984-10-01

    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.

  11. 18F-fluorodeoxyglucose positron emission tomography in colorectal cancer: value in primary staging and follow-up

    International Nuclear Information System (INIS)

    Joerg, L.; Heinisch, M.; Rechberger, E.; Kurz, F.; Klug, R.; Aufschnaiter, M; Hammer, J.; Langsteger, W.

    2002-01-01

    Positron emission tomography using 18 F-fluorodeoxyglucose (FDG-PET) is a encouraging imaging techniques allowing a highly sensitive whole-body search for malignant foci detected by their increased glucose metabolism compared with benign tissues. Several studies are now available that indicate its added value for diagnosis and staging of colorectal cancer. In all, patient management seems to be changed in 20-30 % of patients who undergo fluorodeoxyglucose positron emission tomography in addition to standard staging procedures. Fluorodeoxyglucose positron emission tomography is also useful in monitoring radiation therapy and chemotherapy. Regarding preoperative staging of primary colorectal cancer the literature is very limited. (author)

  12. Positron emission tomography evaluation of somatostatin receptor targeted (64)Cu-TATE-liposomes in a human neuroendocrine carcinoma mouse model

    DEFF Research Database (Denmark)

    Petersen, Anncatrine Luisa; Binderup, Tina; Jølck, Rasmus Irming

    2012-01-01

    end of DSPE-PEG(2000) on PEGylated liposomes with an encapsulated positron emitter (64)Cu that can be utilized for positron emission tomography (PET) imaging. The biodistribution and pharmacokinetics of the (64)Cu-loaded PEGylated liposomes with and without TATE was investigated and their ability...

  13. Basal ganglia disorders studied by positron emission tomography

    International Nuclear Information System (INIS)

    Shinotoh, Hitoshi

    1994-01-01

    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 [ 18 F]6-fluoro-L-dopa ([ 18 F]dopa), and striatal dopamine receptor density with suitable PET ligands. [ 18 F]dopa uptake in the striatum (putamen) is markedly reduced in patients with Parkinson's disease (PD). [ 18 F]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 [ 18 F]dopa uptake is reduced to a similar level in patients with multiple system atrophy (MSA) and PD, caudate [ 18 F] dopa uptake is lower in MSA than PD. However, [ 18 F]dopa PET cannot consistently distinguish MSA from PD because individual ranges of caudate [ 18 F]dopa uptake overlap. D 1 and D 2 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 [ 18 F]dopa uptake have been observed in patients with progressive supranuclear palsy (PSP). Moderate reductions in D 2 receptor binding have been reported in the striatum of PSP patients. The reduction in D 2 receptor binding is more prominent in the caudate than putamen. Striatal [ 18 F]dopa uptake is normal or only mildly reduced in patients with dopa responsive dystonia (DRD). D 2 receptor binding is markedly reduced in patients with Huntington's disease, while striatal [ 18 F]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

  14. Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined

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

    International Nuclear Information System (INIS)

    Wolkin, A.; Jaeger, J.; Brodie, J.D.; Wolf, A.P.; Fowler, J.; Rotrosen, J.; Gomez-Mont, F.; Cancro, R.

    1985-01-01

    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

  16. A positron emission tomography study of cardiac sequelae in children with Kawasaki disease, 1

    International Nuclear Information System (INIS)

    Ohmochi, Yutaka

    1994-01-01

    This study quantitatively measured regional myocardial blood flow (MBF) and perfusable tissue fraction (pTF) in 25 children (mean age: 17.2±2.7) with Kawasaki disease using positron emission tomography and H 2 15 O. Patients were divided into three groups based on coronary angiographic findings. Group 1 consisted of 11 patients with normal coronary angiograms; Group 2, 7 patients with stenotic coronary lesions. There were no significant differences in MBF and pTF among 5 divided regions on the left ventricular wall. Average MBF at rest in Group 1 was 0.91±0.19 ml/min/g. There was a poor correlation between MBF estimated positron emission tomography and patient's age in Group 1. (r=-0.374, Y=-0.0234X + 1.254: p 2 15 O, to determine the functional capacity of coronary artery lesions and myocardial damage in children with Kawasaki disease. (author)

  17. Performance evaluation of BGO block detectors used in positron emission tomography and a coincidence system

    International Nuclear Information System (INIS)

    Kim, J. H.; Choi, Y.; Lim, K. C.; Lee, M. Y.; Woo, S. K.; Lee, K. H.; Kim, S. E.; Choi, Y. S.; Kim, B. T.

    1999-01-01

    We investigated the basic performances of the BGO block detectors, which is used in the GE Advance positron emission tomography. The block detector is composed of 36 small BGO crystals coupled to two 2-channel photomultiplier tubes. In this study, we measured the crystal map and the intrinsic energy resolution of the detector. The coincidence signals between the detectors were also obtained using F-18. The intrinsic energy resolution of the block detector was 69% FWHM at 140 keV and 33% FWHM at 511 keV. High quality crystal map and the coincidence signals between the detectors were successfully obtained. The timing resolution of the detectors are being measured. The results of this study demonstrate the feasibility of developing high performance positron emission tomography

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

    International Nuclear Information System (INIS)

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-01-01

    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

  19. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-05-01

    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.

  1. Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined.

  2. Role of isotope scan, including positron emission tomography/computed tomography, in nodular goitre.

    Science.gov (United States)

    Giovanella, Luca; Ceriani, Luca; Treglia, Giorgio

    2014-08-01

    Nuclear medicine techniques were first used in clinical practice for diagnosing and treating thyroid diseases in the 1950s, and are still an integral part of thyroid nodules work-up. Thyroid imaging with iodine or iodine-analogue isotopes is the only examination able to prove the presence of autonomously functioning thyroid tissue, which excludes malignancy with a high probability. In addition, a thyroid scan with technetium-99m-methoxyisobutylisonitrile is able to avoid unnecessary surgical procedures for cytologically inconclusive thyroid nodules, as confirmed by meta-analysis and cost-effectiveness studies. Finally, positron emission tomography alone, and positron emission tomography combined with computed tomography scans with (18)F-fluoro-2-deoxy-d-glucose are also promising for diagnosing thyroid diseases, but further studies are needed before introducing them to clinical practice. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. A feature point identification method for positron emission particle tracking with multiple tracers

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, Cody, E-mail: cwiggin2@vols.utk.edu [University of Tennessee-Knoxville, Department of Physics and Astronomy, 1408 Circle Drive, Knoxville, TN 37996 (United States); Santos, Roque [University of Tennessee-Knoxville, Department of Nuclear Engineering (United States); Escuela Politécnica Nacional, Departamento de Ciencias Nucleares (Ecuador); Ruggles, Arthur [University of Tennessee-Knoxville, Department of Nuclear Engineering (United States)

    2017-01-21

    A novel detection algorithm for Positron Emission Particle Tracking (PEPT) with multiple tracers based on optical feature point identification (FPI) methods is presented. This new method, the FPI method, is compared to a previous multiple PEPT method via analyses of experimental and simulated data. The FPI method outperforms the older method in cases of large particle numbers and fine time resolution. Simulated data show the FPI method to be capable of identifying 100 particles at 0.5 mm average spatial error. Detection error is seen to vary with the inverse square root of the number of lines of response (LORs) used for detection and increases as particle separation decreases. - Highlights: • A new approach to positron emission particle tracking is presented. • Using optical feature point identification analogs, multiple particle tracking is achieved. • Method is compared to previous multiple particle method. • Accuracy and applicability of method is explored.

  4. Cost Effectiveness of Positron Emission Tomography for the Management of Potentially Operable Non-Small Cell Lung Cancer in Quebec

    Directory of Open Access Journals (Sweden)

    Van Hung Nguyen

    2005-01-01

    Full Text Available BACKGROUND: The potential benefits of positron emission tomography (PET scanning stem from the fact that it can reduce the number of diagnostic examinations; particularly, the number of unnecessary thoracic surgeries.

  5. Dynamic positron emission tomography in man using small bismuth germanate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.; Cahoon, J.L.

    1982-04-01

    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.

  6. Dynamic positron emission tomography in man using small bismuth germanate crystals

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.; Cahoon, J.L.

    1982-04-01

    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

  7. 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...... tomography (PET). Uptake was correlated to quantitative gene expression of known markers of inflammation and plaque vulnerability. METHODS: Ten patients with recent transient ischaemic attack and carotid artery stenosis (>50%) underwent combined FDG-PET and computed tomography angiography (CTA) the day...

  8. Dynamic Positron Emission Tomography [PET] in Man Using Small Bismuth Germanate Crystals

    Science.gov (United States)

    Derenzo, S. E.; Budinger, T. F.; Huesman, R. H.; Cahoon, J. L.

    1982-04-01

    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.

  9. Positron-emission tomography imaging of long-term shape recognition challenges

    OpenAIRE

    Rosier, A.; Cornette, L.; Dupont, P.; Bormans, G.; Michiels, J.; Mortelmans, L.; Orban, G. A.

    1997-01-01

    Long-term visual memory performance was impaired by two types of challenges: a diazepam challenge on acquisition and a sensory challenge on recognition. Using positron-emission tomography regional cerebral blood flow imaging, we studied the effect of these challenges on regional brain activation during the delayed recognition of abstract visual shapes as compared with a baseline fixation task. Both challenges induced a significant decrease in differential activation in the left fusiform gyrus...

  10. A tumor-targeted polymer theranostics platform for positron emission tomography and fluorescence imaging

    Czech Academy of Sciences Publication Activity Database

    Koziolová, Eva; Goel, S.; Chytil, Petr; Janoušková, Olga; Barnhart, T. E.; Cai, W.; Etrych, Tomáš

    2017-01-01

    Roč. 9, č. 30 (2017), s. 10906-10918 ISSN 2040-3364 R&D Projects: GA ČR(CZ) GA15-02986S; GA MZd(CZ) NV16-28594A; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers * positron emission tomography ( PET ) * fluorescence imaging Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 7.367, year: 2016

  11. 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Tuberculosis: Spectrum of Manifestations.

    Science.gov (United States)

    Agarwal, Krishan Kant; Behera, Abhishek; Kumar, Rakesh; Bal, Chandrasekhar

    2017-01-01

    The objective of this article is to provide an illustrative tutorial highlighting the utility of 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography ( 18 F-FDG-PET/CT) imaging to detect spectrum of manifestations in patients with tuberculosis (TB). FDG-PET/CT is a powerful tool for early diagnosis, measuring the extent of disease (staging), and consequently for evaluation of response to therapy in patients with TB.

  12. 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.

  13. 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.

  14. Brain dopaminergic system changes in drug addiction: a review of positron emission tomography findings

    OpenAIRE

    Hou, Haifeng; Wang, Chunyan; Jia, Shaowei; Hu, Shu; Tian, Mei

    2014-01-01

    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 D...

  15. A multicrystal two dimensional BGO detector system for positron emission tomography

    International Nuclear Information System (INIS)

    Casey, M.E.; Nutt, R.

    1986-01-01

    This paper presents a discussion of a new multicrystal detector system as it is implemented in Positron Emission Tomography. The system consists of a 32 x 8 matrix of BGO crystals, a tuned light pipe, and four photomultipliers. The electronics that decodes the position consists of fast preamps, gated integrators, and level comparators. This detector represents a major development toward reducing the cost of PET

  16. 2-¹⁸fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) for postchemotherapy seminoma residual lesions

    DEFF Research Database (Denmark)

    Bachner, M; Loriot, Y; Gross-Goupil, M

    2012-01-01

    2-¹⁸fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) has been recommended in international guidelines in the evaluation of postchemotherapy seminoma residuals. Our trial was designed to validate these recommendations in a larger group of patients.......2-¹⁸fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) has been recommended in international guidelines in the evaluation of postchemotherapy seminoma residuals. Our trial was designed to validate these recommendations in a larger group of patients....

  17. The role of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in resectable pancreatic cancer.

    Science.gov (United States)

    Crippa, Stefano; Salgarello, Matteo; Laiti, Silvia; Partelli, Stefano; Castelli, Paola; Spinelli, Antonello E; Tamburrino, Domenico; Zamboni, Giuseppe; Falconi, Massimo

    2014-08-01

    The role of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in pancreatic ductal adenocarcinoma is debated. We retrospectively assessed the value of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in addition to conventional imaging as a staging modality in pancreatic cancer. (18)Fluoro-deoxyglucose positron emission tomography/computed tomography was performed in 72 patients with resectable pancreatic carcinoma after multi-detector computed tomography positron emission tomography was considered positive for a maximum standardized uptake value >3. Overall, 21% of patients had a maximum standardized uptake value ≤ 3, and 60% of those had undergone neoadjuvant treatment (P=0.0001). Furthermore, 11% of patients were spared unwarranted surgery since positron emission tomography/computed tomography detected metastatic disease. All liver metastases were subsequently identified with contrast-enhanced ultrasound. Sensitivity and specificity of positron emission tomography/computed tomography for distant metastases were 78% and 100%. The median CA19.9 concentration was 48.8 U/mL for the entire cohort and 292 U/mL for metastatic patients (P=0.112). The widespread application of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in patients with resectable pancreatic carcinoma seems not justified. It should be considered in selected patients at higher risk of metastatic disease (i.e. CA19.9>200 U/mL) after undergoing other imaging tests. Neoadjuvant treatment is significantly associated with low metabolic activity, limiting the value of positron emission tomography in this setting. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  18. Modeling and simulation of Positron Emission Mammography (PEM) based on double-sided CdTe strip detectors

    OpenAIRE

    Özşahin, İlker; Ünlü, Mehmet Zübeyir

    2014-01-01

    Breast cancer is the most common leading cause of cancer death among women. Positron Emission Tomography (PET) Mammography, also known as Positron Emission Mammography (PEM), is a method for imaging primary breast cancer. Over the past few years, PEMs based on scintillation crystals dramatically increased their importance in diagnosis and treatment of early stage breast cancer. However, these detectors have significant limitations like poor energy resolution resulting with false-negative resu...

  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. Aspects of positron emission tomography radiochemistry as relevant for food chemistry.

    Science.gov (United States)

    Wuest, F

    2005-12-01

    Positron emission tomography (PET) is a medical imaging technique using compounds labelled with short-lived positron emitting radioisotopes to obtain functional information of physiological, biochemical and pharmacological processes in vivo. The need to understand the potential link between the ingestion of individual dietary agents and the effect of health promotion or health risk requires the exact metabolic characterization of food ingredients in vivo. This exciting but rather new research field of PET would provide new insights and perspectives on food chemistry by assessing quantitative information on pharmocokinetics and pharmacodynamics of food ingredients and dietary agents. To fully exploit PET technology in food chemistry appropriately radiolabelled compounds as relevant for food sciences are needed. The most widely used short-lived positron emitters are (11)C (t(1/2) = 20.4 min) and (18)F (t(1/2) = 109.8 min). Longer-lived radioisotopes are available by using (76)Br (t(1/2) = 16.2 h) and (124)I (t(1/2) = 4.12 d). The present review article tries to discuss some aspects for the radiolabelling of food ingredients and dietary agents either by means of isotopic labelling with (11)C or via prosthetic group labelling approaches using the positron emitting halogens (18)F, (76)Br and (124)I.

  1. 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.

  2. Electron emission and positron production in deep-inelastic heavy-ion reactions

    International Nuclear Information System (INIS)

    Mueller, U.; Soff, G.; Reinhardt, J.; Reus, T. de; Mueller, B.; Greiner, W.

    1984-02-01

    Atomic excitations are used to obtain information on the course of a nuclear reaction. Employing a semiclassical picture we calculate the emission of delta-electrons and positrons in deep inelastic nuclear reactions for the example of U+U collisions incorporating nuclear trajectories resulting from two different nuclear friction models. The emission spectra exhibit characteristic deviations from those expected for elastic Coulomb scattering. The theoretical probabilities are compared with recent experimental data by Backe et al.. A simple model is used to estimate the influence of a three-body break-up of the compound system upon atomic excitations. (orig.)

  3. Application of Positron Emission Tomography to Aerosol Transport Research in a Model of Human Lungs

    Directory of Open Access Journals (Sweden)

    Jicha M.

    2013-04-01

    Full Text Available Positron Emission Tomography (PET is a convenient method for measurement of aerosol deposition in complex models of lungs. It allows not only the evaluation of regional deposition characteristics but also precisely detects deposition hot spots. The method is based on a detection of a pair of annihilation photons moving in opposite directions as a result of positron – electron interaction after the positron emission decay of a suitable radioisotope. Liquid di(2-ethylhexyl sebacate (DEHS particles tagged with fluorine-18 as a radioactive tracer were generated by condensation monodisperse aerosol generator. Aerosol deposition was measured for three different inhalation flowrates and for two sizes of particles. Combination of PET with Computed Tomography (CT in one device allowed precise localisation of particular segments of the model. The results proved correlation of deposition efficiency with Stokes number, which means that the main deposition mechanism is inertial impaction. As a next task the methodology for tagging the solid aerosol particles with radioactive tracer will be developed and deposition of porous and fiber aerosols will be measured.

  4. 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...

  5. Carbon-11 and Fluorine-18 Labeled Amino Acid Tracers for Positron Emission Tomography Imaging of Tumors

    Directory of Open Access Journals (Sweden)

    Aixia Sun

    2018-01-01

    Full Text Available Tumor cells have an increased nutritional demand for amino acids (AAs to satisfy their rapid proliferation. Positron-emitting nuclide labeled AAs are interesting probes and are of great importance for imaging tumors using positron emission tomography (PET. Carbon-11 and fluorine-18 labeled AAs include the [1-11C] AAs, labeling alpha-C- AAs, the branched-chain of AAs and N-substituted carbon-11 labeled AAs. These tracers target protein synthesis or amino acid (AA transport, and their uptake mechanism mainly involves AA transport. AA PET tracers have been widely used in clinical settings to image brain tumors, neuroendocrine tumors, prostate cancer, breast cancer, non-small cell lung cancer (NSCLC and hepatocellular carcinoma. This review focuses on the fundamental concepts and the uptake mechanism of AAs, AA PET tracers and their clinical applications.

  6. Carbon-11 and Fluorine-18 Labeled Amino Acid Tracers for Positron Emission Tomography Imaging of Tumors

    Science.gov (United States)

    Sun, Aixia; Liu, Xiang; Tang, Ganghua

    2017-12-01

    Tumor cells have an increased nutritional demand for amino acids(AAs) to satisfy their rapid proliferation. Positron-emitting nuclide labeled AAs are interesting probes and are of great importance for imaging tumors using positron emission tomography (PET). Carbon-11 and fluorine-18 labeled AAs include the [1-11C] amino acids, labeling alpha-C- amino acids, the branched-chain of amino acids and N-substituted carbon-11 labeled amino acids. These tracers target protein synthesis or amino acid(AA) transport, and their uptake mechanism mainly involves AA transport. AA PET tracers have been widely used in clinical settings to image brain tumors, neuroendocrine tumors, prostate cancer, breast cancer, non–small cell lung cancer (NSCLC) and hepatocellular carcinoma. This review focuses on the fundamental concepts and the uptake mechanism of AAs, AA PET tracers and their clinical applications.

  7. Brain energy metabolism and dopaminergic function in Huntington's disease measured in vivo using positron emission tomography

    International Nuclear Information System (INIS)

    Leenders, K.L.; Frackowiak, R.S.; Quinn, N.; Marsden, C.D.

    1986-01-01

    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-[ 18 F]-fluorodopa uptake was normal, but dopamine (D2) receptor binding was decreased when compared to normal subjects

  8. [Fluorinated analogs of nucleosides and fluorinated tracers of gene expression for positron emission tomography].

    Science.gov (United States)

    Couturier, Olivier; Chatal, Jean-François; Hustinx, Roland

    2004-09-01

    18F-FDG is currently the only fluorinated tracer used in routine clinical positron emission tomography (PET). Fluorine 18 is considered as the ideal radioisotope for PET, thanks to a low positron energy, which not only limits the dose rate to the patients but also provides high-resolution images. Furthermore, the 110 min. physical half-life allows for high-yield radiosynthesis, transport from the production site to the imaging site, and imaging protocols that could span hours, which permits dynamic studies and assessing metabolic processes that may be fairly slow. Recently, synthesis of fluorinated tracers from prosthetic group precursors, which allows easier radiolabeling of biomolecules, has given a boost to the development of numerous fluorinated tracers. Given the wide availability of fluorine 18, such tracers may well develop into important routine tracers. This article is a review of the literature concerning fluorinated analogs of nucleosides and fluorinated radiotracers of gene expression recently developed and under investigation.

  9. Noninvasive assessment of canine myocardial oxidative metabolism with carbon-11 acetate and positron emission tomography

    International Nuclear Information System (INIS)

    Brown, M.A.; Myears, D.W.; Bergmann, S.R.

    1988-01-01

    Noninvasive quantification of regional myocardial metabolism would be highly desirable to evaluate pathogenetic mechanisms of heart disease and their response to therapy. It was previously demonstrated that the metabolism of radiolabeled acetate, a readily utilized myocardial substrate predominantly metabolized to carbon dioxide (CO2) by way of the tricarboxylic acid cycle, provides a good index of oxidative metabolism in isolated perfused rabbit hearts because of tight coupling between the tricarboxylic acid cycle and oxidative phosphorylation. In the present study, in a prelude to human studies, the relation between myocardial clearance of carbon-11 (11C)-labeled acetate and myocardial oxygen consumption was characterized in eight intact dogs using positron emission tomography. Anesthetized dogs were studied during baseline conditions and again during either high or low work states induced pharmacologically. High myocardial extraction and rapid blood clearance of tracer yielded myocardial images of excellent quality. The turnover (clearance) of 11C radioactivity from the myocardium was biexponential with the mean half-time of the dominant rapid phase averaging 5.4 +/- 2.2, 2.8 +/- 1.3 and 11.1 +/- 1.3 min in control, high and low work load studies, respectively. No significant difference was found between the rate of clearance of 11C radioactivity from the myocardium measured noninvasively with positron emission tomography and the myocardial efflux of 11CO2 measured directly from the coronary sinus. The rate of clearance of the 11C radioactivity from the heart correlated closely with myocardial oxygen consumption (r = 0.90, p less than 0.001) as well as with the rate-pressure product (r = 0.95, p less than 0.001). Hence, the rate of oxidation of 11C-acetate can be determined noninvasively with positron emission tomography, providing a quantitative index of oxidative metabolism under diverse conditions

  10. The current status of positron emission mammography in breast cancer diagnosis.

    Science.gov (United States)

    Kalles, Vasileios; Zografos, George C; Provatopoulou, Xeni; Koulocheri, Dimitra; Gounaris, Antonia

    2013-04-01

    Mammography is currently the standard breast cancer screening procedure, even though it is constrained by low specificity in the detection of malignancy and low sensitivity in women with dense breast tissue. Modern imaging modalities, such as magnetic resonance imaging (MRI), have been developed in an effort to replace or complement mammography, because the early detection of breast cancer is critical for efficient treatment and long-term survival of patients. Nuclear medicine imaging technology has been introduced in the field of oncology with the development of positron emission tomography (PET), positron emission tomography/computed tomography (PET/CT) and, ultimately, positron emission mammography (PEM). PET offers the advantage of precise diagnosis, by measuring metabolism with the use of a radiotracer and identifying changes at the cellular level. PET/CT imaging allows for a more accurate assessment by merging the anatomic localization to the functional image. However, both techniques have not yet been established as diagnostic tools in early breast cancer detection, primarily because of low sensitivity, especially for sub-centimeter and low-grade tumors. PEM, a breast-specific device with increased spatial resolution, has been developed in order to overcome these limitations. It has demonstrated higher detectability than PET/CT and comparable or better sensitivity than MRI. The ability to target the lesions visible in PEM with PEM-guided breast biopsy systems adds to its usability in the early diagnosis of breast cancer. The results from recent studies summarized in this review indicate that PEM may prove to be a useful first-line diagnostic tool, although further evaluation and improvement are required.

  11. Basic concepts on positron emission tomography in oncology and pediatric peculiarities

    International Nuclear Information System (INIS)

    Giammarile, F.; Pellet, O.

    2002-01-01

    (Positron Emission Tomography (PET) is an old functional imaging method, pertaining to the nuclear medicine field, based on the utilisation of positrons emitting nuclei, fixed on targeted molecules. Available since the Seventies, the clinical impact of PET grows daily, particularly in oncology. This method rests on the coincidence detection of the photons issued by the annihilation of the positron. It can be carried out on dedicated scans, equipped with a crown of detectors (PET camera) or on classical cameras whose crystal and electronic system has been adapted CDET camera). The 2-deoxy-2 fluoro-D-glucose marked with fluorine 18 [18FDG or FDG is a glucose analogue. Its cellular uptake uses the facilitated transport of glucose but its metabolism is partial because, contrary to this one, it remains within the cell. This allows functional studies (evaluation of glucose metabolism) on the cell. FDG uptake is thus increased under the pathological conditions comprising an increase in the consumption of glucose either by increase in glycolysis (malignant tumoral tissue) or by increase in the only anaerobic cycle (ischaemia). Consequently, this diagnostic method identifies in vivo the hyper-metabolism of malignant cells and provides a quantification of the tumoral glycolysis, during and after treatment. In Paediatrics, its diffusion and its use in clinical routine, are currently limited, because of the limited availability of the equipment. It is probable that with the awaited rise of PET in France, the paediatric applications will also see their place increasing in the diagnostic strategy of cancer. (authors)

  12. Positron emission tomographic imaging of tumors using monoclonal antibodies. Progress report, April 15, 1992--October 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Zalutsky, M.R.

    1992-08-01

    This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.

  13. ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography for the evaluation of bone metastasis in patients with gastric cancer.

    Science.gov (United States)

    Ma, Dae Won; Kim, Jie-Hyun; Jeon, Tae Joo; Lee, Yong Chan; Yun, Mijin; Youn, Young Hoon; Park, Hyojin; Lee, Sang In

    2013-09-01

    The roles of positron emission tomography and bone scanning in identifying bone metastasis in gastric cancer are unclear. We compared the usefulness of positron emission tomography-computed tomography and scanning in detecting bone metastasis in gastric cancer. Data from 1485 patients diagnosed with gastric cancer who had undergone positron emission tomography-computed tomography and scanning were reviewed. Of 170 enrolled patients who were suspected of bone metastasis in either positron emission tomography or scanning, 81.2% were confirmed to have bone metastasis. The sensitivity, specificity, and accuracy were 93.5%, 25.0%, and 80.6%, respectively, for positron emission tomography and 93.5%, 37.5%, and 82.9%, respectively, for scanning. 87.7% of patients with bone metastasis showed positive findings on two modalities. 15.0% of solitary bone metastases were positive on positron emission tomography only. Positron emission tomography was superior to scanning for the detection of synchronous bone metastasis, but the two modalities were similar for the detection of metachronous bone metastasis. The concordance rate of response assessment after treatment between two modalities was moderate. Positron emission tomography-computed tomography may be more effective for the diagnosis of bone metastasis in the initial staging workup. Conversely, bone scanning and positron emission tomography-computed tomography may be similarly effective for the detection of metachronous bone metastasis. Copyright © 2013 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  14. Caffeine and human cerebral blood flow: A positron emission tomography study

    International Nuclear Information System (INIS)

    Cameron, O.G.; Modell, J.G.; Hariharan, M.

    1990-01-01

    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 p a CO 2 and increased systolic blood pressure significantly; the change in p a CO 2 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

  15. Fluorine-18-fluorodeoxyglucose Positron Emission Tomography in Diffuse Large B-cell Lymphoma

    DEFF Research Database (Denmark)

    Mylam, Karen Juul; Nielsen, Anne Lerberg; Pedersen, Lars Møller

    2014-01-01

    Diffuse large B-cell lymphoma (DLBCL) is an aggressive and potentially curable type of lymphoma. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) is part of clinical routine for DLBCL in most hospitals and also recommended for staging and end-of-therapy evaluation. FDG......-PET/computed tomography (CT) is able to identify nodal and extranodal sites with greater accuracy than CT alone. Little evidence supports the use of surveillance FDG-PET imaging in the follow-up setting because of high rates of false-positive scans and because most studies are retrospective. This article discusses FDG...

  16. 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...... or PET/computed tomography imaging. Methods: Studies evaluating thyroid carcinomas discovered incidentally in patients or healthy volunteers by (18)F-FDG PET were systematically searched in the PubMed database from 2000 to 2011. The main exclusion criteria were known thyroid disease, lack of assigned...

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

    Science.gov (United States)

    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 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. PMID:24019680

  18. Amyloid and metabolic positron emission tomography imaging of cognitively normal adults with Alzheimer's parents

    DEFF Research Database (Denmark)

    Mosconi, Lisa; Rinne, Juha O; Tsui, Wai H

    2013-01-01

    emission tomography (PET) with (11)C-Pittsburgh compound B (PiB) and 18F-fluoro-2-deoxy-d-glucose (FDG). These included 19 NL with a maternal history (MH), 12 NL with a paternal history (PH), and 16 NL with negative family history of AD (NH). Automated regions of interest, statistical parametric mapping......This study examines the relationship between fibrillar beta-amyloid (Aβ) deposition and reduced glucose metabolism, a proxy for neuronal dysfunction, in cognitively normal (NL) individuals with a parent affected by late-onset Alzheimer's disease (AD). Forty-seven 40-80-year-old NL received positron...

  19. Prognostication and Risk-Adapted Therapy of Hodgkin's Lymphoma Using Positron Emission Tomography

    Directory of Open Access Journals (Sweden)

    Yvette L. Kasamon

    2011-01-01

    Full Text Available The use of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET for response assessment in lymphoma is now widespread. Prognostic information obtained from PET performed after two to three cycles of chemotherapy may guide more individualized, risk-adapted therapeutic strategies. Progress in the risk stratification of Hodgkin's lymphoma through midtreatment PET is reviewed, with a focus on management implications in newly diagnosed and relapsed disease. How to tailor treatment on the basis of the interim PET result is not yet defined but is the subject of ongoing trials.

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

    International Nuclear Information System (INIS)

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

    1984-01-01

    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)

  1. Metabolic and hemodynamic evaluation of brain metastases from small cell lung cancer with positron emission tomography

    DEFF Research Database (Denmark)

    Lassen, U; Andersen, P; Daugaard, G

    1998-01-01

    Brain metastases from small cell lung cancer respond to chemotherapy, but response duration is short and the intracerebral concentration of chemotherapy may be too low because of the characteristics of the blood-brain barrier. Positron emission tomography has been applied in a variety of tumors...... for studies of metabolic and hemodynamic features. This study was performed to determine regional cerebral metabolic rate of glucose (rCMRglu), regional cerebral blood flow (rCBF), and regional cerebral blood volume (rCBV) in brain metastases from small cell lung cancer and the surrounding brain. Tumor r...

  2. Implementation of sum-peak method for standardization of positron emission radionuclides

    International Nuclear Information System (INIS)

    Fragoso, Maria da Conceicao de Farias; Oliveira, Mercia Liane de; Lima, Fernando Roberto de Andrade

    2015-01-01

    Positron Emission Tomography (PET) is being increasingly recognized as an important quantitative imaging tool for diagnosis and assessing response to therapy. As correct dose administration plays a crucial part in nuclear medicine, it is important that the instruments used to assay the activity of the short-lived radionuclides are calibrated accurately, with traceability to the national or international standards. The sum-peak method has been widely used for radionuclide standardization. The purpose of this study was to implement the methodology for standardization of PET radiopharmaceuticals at the Regional Center for Nuclear Sciences of the Northeast (CRCN-NE). (author)

  3. Treatment modification of yttrium-90 radioembolization based on quantitative positron emission tomography/CT imaging.

    Science.gov (United States)

    Chang, Ted T; Bourgeois, Austin C; Balius, Anastasia M; Pasciak, Alexander S

    2013-03-01

    Treatment activity for yttrium-90 ((90)Y) radioembolization when calculated by using the manufacturer-recommended technique is only partially patient-specific and may result in a subtumoricidal dose in some patients. The authors describe the use of quantitative (90)Y positron emission tomography/computed tomography as a tool to provide patient-specific optimization of treatment activity and evaluate this new method in a patient who previously received traditional (90)Y radioembolization. The modified treatment resulted in a 40-Gy increase in absorbed dose to tumor and complete resolution of disease in the treated area within 3 months. Copyright © 2013. Published by Elsevier Inc.

  4. 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)

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

    International Nuclear Information System (INIS)

    Kuhl, D.E.

    1991-01-01

    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

  7. Positron emission tracking of individual particles in particle-laden rimming flow

    International Nuclear Information System (INIS)

    Denissenko, P.; Thomas, P. J.; Guyez, E.; Parker, D. J.; Seville, J. P. K.

    2014-01-01

    The motion of a single tracer particle in particle-laden rimming flows is investigated experimentally by means of Positron Emission Particle Tracking (PEPT). Semi-dilute suspensions, with a volume fraction of 8% of heavy particles are considered. The trajectory of the tracer particle is monitored for several thousand cylinder revolutions and related to the optically recorded drift of the large-scale granular segregation bands developing in the cylinder. Results of the data analysis provide first insights into the relation between behaviour of individual particles and the spatiotemporal dynamics displayed by the macroscopic particle-segregation patterns

  8. Monitoring variables affecting positron emission tomography measurements of cerebral blood flow in anaesthetized pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Zois, Nora Elisabeth; Simonsen, Mette

    2018-01-01

    Background Positron emission tomography (PET) imaging of anaesthetized pig brains is a useful tool in neuroscience. Stable cerebral blood flow (CBF) is essential for PET, since variations can affect the distribution of several radiotracers. However, the effect of physiological factors regulating...... and the monitoring parameters. Results No significant statistical correlations were found between CBF and the nine monitoring variables. However, we found that arterial carbon dioxide tension (PaCO2) and body temperature were important predictors of CBF that should be observed and kept constant. In addition, we...

  9. Human hemispheric infarction studied by positron emission tomography and the 150 continuous inhalation technique

    International Nuclear Information System (INIS)

    Baron, J.-C.; Bousser, M.G.; Comar, D.; Kellershohn, C.

    1979-01-01

    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 15 O 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

  10. Positron emission mammography in breast cancer presurgical planning: comparisons with magnetic resonance imaging

    OpenAIRE

    Schilling, Kathy; Narayanan, Deepa; Kalinyak, Judith E.; The, Juliette; Velasquez, Maria Victoria; Kahn, Simone; Saady, Matthew; Mahal, Ravinder; Chrystal, Larraine

    2010-01-01

    Purpose The objective of this study was to compare the performance characteristics of 18F-fluorodeoxyglucose (FDG) positron emission mammography (PEM) with breast magnetic resonance imaging (MRI) as a presurgical imaging and planning option for index and ipsilateral lesions in patients with newly diagnosed, biopsy-proven breast cancer. Methods Two hundred and eight women >25 years of age (median age = 59.7 ± 14.1 years) with biopsy-proven primary breast cancer enrolled in this prospective, si...

  11. Recommendations for measurement of tumour vascularity with positron emission tomography in early phase clinical trials

    International Nuclear Information System (INIS)

    Aboagye, Eric O.; Kenny, Laura M.; Myers, Melvyn; Gilbert, Fiona J.; Fleming, Ian N.; Beer, Ambros J.; Cunningham, Vincent J.; Marsden, Paul K.; Visvikis, Dimitris; Gee, Antony D.; Groves, Ashley M.; Cook, Gary J.; Kinahan, Paul E.; Clarke, Larry

    2012-01-01

    The evaluation of drug pharmacodynamics and early tumour response are integral to current clinical trials of novel cancer therapeutics to explain or predict long term clinical benefit or to confirm dose selection. Tumour vascularity assessment by positron emission tomography could be viewed as a generic pharmacodynamic endpoint or tool for monitoring response to treatment. This review discusses methods for semi-quantitative and quantitative assessment of tumour vascularity. The radioligands and radiotracers range from direct physiological functional tracers like [ 15 O]-water to macromolecular probes targeting integrin receptors expressed on neovasculature. Finally we make recommendations on ways to incorporate such measurements of tumour vascularity into early clinical trials of novel therapeutics. (orig.)

  12. The timing of adoption of positron emission tomography: a real options approach.

    Science.gov (United States)

    Pertile, Paolo; Torri, Emanuele; Flor, Luciano; Tardivo, Stefano

    2009-09-01

    This paper presents the economic evaluation from a hospital's perspective of the investment in positron emission tomography, adopting a real options approach. The installation of this equipment requires a major capital outlay, while uncertainty on several key variables is substantial. The value of several timing strategies, including sequential investment, is determined taking into account that future decisions will be based on the information available at that time. The results show that adopting this approach may have an impact on the timing of investment, because postponing the investment may be optimal even when the Expected Net Present Value of the project is positive.

  13. Positron emission tomographic images and expectation maximization: A VLSI architecture for multiple iterations per second

    International Nuclear Information System (INIS)

    Jones, W.F.; Byars, L.G.; Casey, M.E.

    1988-01-01

    A digital electronic architecture for parallel processing of the expectation maximization (EM) algorithm for Positron Emission tomography (PET) image reconstruction is proposed. Rapid (0.2 second) EM iterations on high resolution (256 x 256) images are supported. Arrays of two very large scale integration (VLSI) chips perform forward and back projection calculations. A description of the architecture is given, including data flow and partitioning relevant to EM and parallel processing. EM images shown are produced with software simulating the proposed hardware reconstruction algorithm. Projected cost of the system is estimated to be small in comparison to the cost of current PET scanners

  14. 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.

  15. Radiolabeled phosphonium salts as mitocondrial voltage sensors for positron emission tomography myocardial imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Yon; Min, Jung Joon [Dept. of Nuclear Medicine,Chonnam National University Medical School and Hwasun Hospital, Gwangju (Korea, Republic of)

    2016-09-15

    Despite substantial advances in the diagnosis of cardiovascular disease, {sup 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 tetraphenyl phosphonium 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.

  16. Diagnosis of a cardiac angiosarcoma by fluorine-18 fluordeoxyglucose positron emission tomography

    International Nuclear Information System (INIS)

    Freudenberg, L.S.; Rosenbaum, S.J.; Eising, E.G.; Bockisch, A.; Schulte-Herbrueggen, J.; Lauenstein, T.; Wolff, A.

    2002-01-01

    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.)

  17. Time stamp generation with inverse FIR filters for Positron Emission Tomography

    International Nuclear Information System (INIS)

    Namias, Mauro

    2009-01-01

    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. Positron Emission Tomography-Scanner at Children's Hospital of Michigan at Detroit, Michigan

    International Nuclear Information System (INIS)

    1992-01-01

    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)

  19. 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.

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

    International Nuclear Information System (INIS)

    Hara, Toshihiko; Iio, Masaaki; Tsukiyama, Takashi

    1988-01-01

    Positron emission tomography (PET) using 11 C-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 11 CO 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 14 C-inulin. (orig.)

  1. 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)

    Loc'h, C.

    1988-04-01

    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 [fr

  2. Fluorodeoxyglucose-positron emission tomography/computed tomography imaging features of colloid adenocarcinoma of the lung: a case report.

    Science.gov (United States)

    Wang, ZhenGuang; Yu, MingMing; Chen, YueHua; Kong, Yan

    2017-07-27

    Colloid adenocarcinoma of the lung is a rare subtype of variants of invasive adenocarcinomas. We report the appearance of this unusual entity on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography. A 60-year-old man of Chinese Han nationality coughed with a little white sputum for 1 month. Chest computed tomography showed multiple bilateral subpleural nodules and plaques accompanied by air bronchograms, which were most concentrated in the lower lobe of his right lung. Positron emission tomography indicated increased radioactivity uptake with a maximum standardized uptake value of 3.5. Positron emission tomography/computed tomography showed a soft tissue density lesion in his left adrenal gland with a maximum standardized uptake value of 4.1. The positron emission tomography/computed tomography appearance suggested a primary colloid adenocarcinoma in the lower lobe of his right lung accompanied by intrapulmonary and left adrenal gland metastases. The diagnostic rate of colloid adenocarcinoma can be increased by combining the anatomic and metabolic information of lesions. The advantage of positron emission tomography/computed tomography in the diagnosis of colloid adenocarcinoma, as with other cancers, is the ability to locate extrapulmonary disease, facilitating clinical staging.

  3. A method for measuring the energy spectrum of coincidence events in positron emission tomography.

    Science.gov (United States)

    Goertzen, Andrew L; Stout, David B; Thompson, Christopher J

    2010-01-21

    Positron emission tomography (PET) system energy response is typically characterized in singles detection mode, yet there are situations in which the energy spectrum of coincidence events might be different than the spectrum measured in singles mode. Examples include imaging with isotopes that emit a prompt gamma in coincidence with a positron emission, imaging with low activity in a LSO/LYSO-based cameras, in which the intrinsic activity is significant, and in high scatter situations where the two 511 keV photons have different scattering probabilities (i.e. off-center line source). The ability to accurately measure the energy spectrum of coincidence events could be used for validating simulation models, optimizing energy discriminator levels and examining scatter models and corrections. For many PET systems operating in coincidence mode, the only method available for estimating the energy spectrum is to step the lower and upper level discriminators (LLD and ULD). Simple measurement techniques such as using a narrow sliding energy window or stepping only the LLD will not yield a spectrum of coincidence events that is accurate for cases where there are different energy components contributing to the spectrum. In this work we propose a new method of measuring the energy spectrum of coincidence events in PET based on a linear combination of two sets of coincident count measurements: one made by stepping the LLD and one made by stepping the ULD. The method was tested using both Monte Carlo simulations of a Siemens microPET R4 camera and measured data acquired on a Siemens Inveon PET camera. The results show that our energy spectrum calculation method accurately measures the coincident energy spectra for cases including the beta/gamma spectrum of the (176)Lu intrinsic activity present in the LSO scintillator crystals, a (68)Ge source and an (124)I source (in which there are prompt gamma-rays emitted together with the positron).

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

    International Nuclear Information System (INIS)

    Gould, K.L.; Goldstein, R.A.; Mullani, N.A.

    1989-01-01

    This report describes a cost analysis for clinical positron emission tomography (PET) of the heart using generator produced rubidium-82 ( 82 Rb). 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 82 Rb may be modestly higher than for 201 Tl, 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

  5. Performance of Positron Emission Tomography and Positron Emission Tomography/Computed Tomography Using Fluorine-18-Fluorodeoxyglucose for the Diagnosis, Staging, and Recurrence Assessment of Bone Sarcoma

    Science.gov (United States)

    Liu, Fanxiao; Zhang, Qingyu; Zhu, Dezhi; Li, Zhenfeng; Li, Jianmin; Wang, Boim; Zhou, Dongsheng; Dong, Jinlei

    2015-01-01

    Abstract To investigate the performance of fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and PET/computed tomography (CT) in the diagnosis, staging, restaging, and recurrence surveillance of bone sarcoma by systematically reviewing and meta-analyzing the published literature. To retrieve eligible studies, we searched the MEDLINE, Embase, and the Cochrane Central library databases using combinations of following Keywords: “positron emission tomography” or “PET,” and “bone tumor” or “bone sarcoma” or “sarcoma.” Bibliographies from relevant articles were also screened manually. Data were extracted and the pooled sensitivity, specificity, and diagnostic odds ratio (DOR), on an examination-based or lesion-based level, were calculated to appraise the diagnostic accuracy of 18F-FDG PET and PET/CT. All statistical analyses were performed using Meta-Disc 1.4. Forty-two trials were eligible. The pooled sensitivity and specificity of PET/CT to differentiate primary bone sarcomas from benign lesions were 96% (95% confidence interval [CI], 93–98) and 79% (95% CI, 63–90), respectively. For detecting recurrence, the pooled results on an examination-based level were sensitivity 92% (95% CI, 85–97), specificity 93% (95% CI, 88–96), positive likelihood ratio (PLR) 10.26 (95% CI, 5.99–17.60), and negative likelihood ratio (NLR) 0.11 (95% CI, 0.05–0.22). For detecting distant metastasis, the pooled results on a lesion-based level were sensitivity 90% (95% CI, 86–93), specificity 85% (95% CI, 81–87), PLR 5.16 (95% CI, 2.37–11.25), and NLR 0.15 (95% CI, 0.11–0.20). The accuracies of PET/CT for detecting local recurrence, lung metastasis, and bone metastasis were satisfactory. Pooled outcome estimates of 18F-FDG PET were less complete compared with those of PET/CT. 18F-FDG PET and PET/CT showed a high sensitivity for diagnosing primary bone sarcoma. Moreover, PET/CT demonstrated excellent accuracy for the staging

  6. Influence of 18F-fluorodeoxyglucose-positron emission tomography on computed tomography-based radiation treatment planning for oesophageal cancer

    International Nuclear Information System (INIS)

    Everitt, C.; Leong, T.

    2006-01-01

    The addition of positron emission tomography (PET) information to CT-based radiotherapy treatment planning has the potential to improve target volume definition through more accurate localization of the primary tumour and involved regional lymph nodes. This case report describes the first patient enrolled to a prospective study evaluating the effects of coregistered positron emission tomography/CT images on radiotherapy treatment planning for oesophageal cancer. The results show that if combined positron emission tomography/CT is used for radiotherapy treatment planning, there may be alterations to the delineation of tumour volumes when compared to CT alone. For this patient, a geographic miss of tumour would have occurred if CT data alone were used for radiotherapy planning Copyright (2006) Blackwell Publishing Asia Pty Ltd

  7. Cerebral blood flow measured by positron emission tomography during normothermic cardiopulmonary bypass: An experimental porcine study

    DEFF Research Database (Denmark)

    Thomassen, Sisse Anette; Kjaergaard, Benedict; Alstrup, Aage Kristian Olsen

    2018-01-01

    min and, thereafter, all the pigs returned to 60 mL/kg/min for another 60 min. The MAP was measured continuously and the CBF was measured by positron emission tomography (PET) during spontaneous circulation and at each CPB pump flow after 30 min of steady state. Results: Two pigs were excluded due...... emission tomography (PET) using 15O-labelled water with no pharmacological interventions to maintain the MAP. Methods: Eight pigs (69-71 kg) were connected to normothermic CPB. After 60 minutes (min) with a CPB pump flow of 60 mL/kg/min, the pigs were changed to either 35 mL/kg/min or 47.5 mL/kg/min for 60......Background: Mean arterial blood pressure (MAP) and/or pump flow during normothermic cardiopulmonary bypass (CPB) are the most important factors of cerebral perfusion. The aim of this study was to explore the influence of CPB blood flow on cerebral blood flow (CBF) measured by dynamic positron...

  8. Carbon-11 labelled tyrosine to study tumor metabolism by positron emission tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Bolster, J.M.; Vaalburg, W.; Paans, A.M.J.; Dijk, T.H. van; Elsinga, P.H.; Zijlstra, J.B.; Piers, D.A.; Mulder, N.H.; Woldring, M.G.; Wynberg, H.

    1986-10-01

    To measure the rate of protein synthesis in human neoplasms by positron emission tomography, we prepared no carrier added DL-(1-/sup 11/C)-tyrosine by /sup 11/C-carboxylation of the appropriate ..cap alpha..-lithioisocyanide followed by hydrolysis of the isocyanide function and removal of the protecting methoxy group. The purification, resolution and solvent switch to saline was performed by high performance liquid chromatography (HPLC). DL-(1-/sup 11/C)-Tyrosine in 0.1 N NaH/sub 2/PO/sub 4/ buffer was prepared with a radiochemical yield of 8%-16% (EOS, 35 min). The enantiometric separation and solvent switch to saline were achieved in 5 min and 10 min respectively. Consequently l-(1-/sup 11/C)-tyrosine in physiological saline was obtained in 2%-4% radiochemical yield. Tumor accumulation in rats with the experimental WALKER 256 carcinosarcoma was observed for both the L- and D-isomer. Using positron emission tomography a tumor/muscle ratio of two was observed for the L-isomer 15 min after injection. The corresponding figure for the D-isomer was 2.5. The first clinical results with DL-(1-/sup 11/C)-tyrosine show accumulation of radioactivity in meningioma, a primary breast carcinoma and in liver metastases of a colonic carcinoma.

  9. Positron emission tomography: Indications in lung cancer – Prospective experience of a department

    Directory of Open Access Journals (Sweden)

    Diva Ferreira

    2007-01-01

    Full Text Available Positron emission tomography (PET is a new technique in nuclear medicine. It uses biological radiotracers such as 18F-fluoro-2-deoxyglucose (FDG which permit the detection of suspected lesions with metabolic alterations that take up the glucose isotope too avidly, as is the case with neoplastic cells. PET has become an innovatory and important imaging tool for evaluating patients with lung cancer. The present recommended uses of PET include lung cancer diagnosis and the intrathoracic and extrathoracic staging in N-SCLC. Resumo: A tomografia emissora de positrões (PET é uma tecnologia recente no âmbito da medicina nuclear. Utiliza radionuclídeos biológicos como o 18F-fluoro-2-deoxy- D-glicose (FDG permitindo detectar locais onde o metabolismo está aumentado, como no caso de células neoplásicas. Tem vindo a tornar-se um inovador e importante meio imagiológico no cancro do pulmão. Recomendações actuais incluem o diagnóstico de cancro do pulmão, bem como o estadiamento loco- -regional e à distancia do CPNPC. Key-words: Positron emission tomography, lung cancer, diagnosis, staging, Palavras-chave: Tomografia emissora de positrões, cancro do pulmão, diagnóstico, estadiamento

  10. Clinical Imaging Characteristics of the Positron Emission Mammography PEM Flex Solo II.

    Science.gov (United States)

    Macdonald, Lawrence; Edwards, John; Lewellen, Thomas; Rogers, James; Kinahan, Paul

    2008-10-01

    Positron emission mammography (PEM) uses two opposing gamma-ray imagers and limited-angle tomography techniques to image radiotracer distributions within the breast. Due to their smaller size and closer proximity to the source, dedicated PEM cameras can provide better spatial resolution and count sensitivity than whole-body positron emission tomographs. We performed several clinical imaging tests on a commercially available PEM camera, the PEM Flex Solo II. This system is comprised of two opposing 6 cm × 16.4 cm detectors that scan in unison to cover up to a 24 cm × 16.4 cm field of view (FOV). We measured spatial resolution, uniformity, recovery coefficients (RC), and quantification using the system clinical software. Image linearity and coefficient of variation (CV) at the edge of the FOV were also characterized. Anecdotal examples of clinical patient data are presented. Spatial resolution is 2.4 mm FWHM for image planes parallel to the detector faces; background variability is 6%; quantification and RC varied within the FOV; positioning linearity began at ~ 13 mm from the edge of the detector housing; CV increased rapidly at the edge of the FOV due to limited sampling in these image planes.

  11. An amorphous selenium based positron emission mammography camera with avalanche gain.

    Science.gov (United States)

    Reznik, A; Lui, B J M; Rowlands, J A

    2005-02-01

    Early diagnosis of breast cancer is crucial for effective treatment, and the need exists for greater detection ability and specificity than possible by screening x-ray mammography (currently the primary imaging technique for the detection of breast lesions). Positron Emission Tomography (PET) using the radiotracer 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) offers a noninvasive, highly sensitive method for the diagnosis of breast cancer. Images from PET contain unique metabolic information that is not available from anatomical imaging techniques. We propose a Positron Emission Mammography (PEM) imaging system that maintains the established high specificity of FDG PET while providing improved collection efficiency for the radiotracer signal and the potential for images with better spatial resolution. This PEM system will enable detection of lesions that are considerably smaller than those that can be visualized using whole body PET imaging. The compact dual-head PEM camera will be based on an amorphous selenium (a-Se) avalanche photodetector and the scintillator lutetium oxyorthosilicate (LSO). The camera promises high collection efficiency by combining the fast scintillation light decay and high light yield of LSO with the excellent quantum efficiency, large avalanche gain, and rapid response time of a-Se. We have measured the gain and readout time of an 8 microm a-Se layer and demonstrated the feasibility of the proposed PEM camera.

  12. Whole body muscle activity during the FIFA 11+ program evaluated by positron emission tomography.

    Directory of Open Access Journals (Sweden)

    Junsuke Nakase

    Full Text Available 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 exercise group performed part 2 of the 11+for 20 min, after which FDG was injected. They then performed part 2 of the 11+for 20 min, and rested for 25 min in a sitting position. Positron emission tomography-computed tomography images were obtained 50 min after FDG injection in each group. Regions of interest were defined within 30 muscles. The standardized uptake value was calculated to examine the FDG uptake of muscle tissue per unit volume. RESULTS: FDG accumulation within the abdominal rectus, gluteus medius and minimus were significantly higher in the exercise group than in the control group (P<0.05. CONCLUSION: The hip abductor muscles and abdominal rectus were active during part 2 of the FIFA 11+ program.

  13. High-resolution PET (positron emission tomography) for medical science studies

    Energy Technology Data Exchange (ETDEWEB)

    Budinger, T.F.; Derenzo, S.E.; Huesman, R.H.; Jagust, W.J.; Valk, P.E. (Lawrence Berkeley Lab., CA (USA))

    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. 6 refs., 21 figs.

  14. Positron emission tomography studies in the normal and abnormal ageing of human brain

    International Nuclear Information System (INIS)

    Comar, D.; Baron, J.C.

    1987-01-01

    Until recently, the investigation of the neurophysiological correlates of normal and abnormal ageing of the human brain was limited by methodological constraints, as the technics available provided only a few parameters (e.g. electroencephalograms, cerebral blood flow) monitored in superficial brain structures in a grossly regional and poorly quantitative way. Lately several non invasive techniques have been developed which allow to investigate in vivo both quantitatively and on local basis a number of previously inaccessible important aspects of brain function. Among these techniques, such as single photon emission tomography imaging of computerized electric events, nuclear magnetic resonance, positron emission tomography stands out as the most powerful and promising method since it allows the in vivo measurement of biochemical and pharmacological parameters

  15. Cerebral blood volume measured with inhaled C15O and positron emission tomography

    International Nuclear Information System (INIS)

    Martin, W.R.; Powers, W.J.; Raichle, M.E.

    1987-01-01

    Local cerebral blood volume (CBV) has been measured previously with inhaled 11 CO and positron emission tomography (PET). The model used assumes that equilibrium in tracer concentration has occurred between arterial and systemic venous blood before the PET measurement is made. To verify that this model may be used with the much shorter half-lived C 15 O, we have simultaneously measured arterial and venous blood radioactivity following C 15 O inhalation. Equilibrium occurred 95 +/- 39 s after inhalation (n = 7). If the PET measurement is commenced prior to arteriovenous equilibrium, significant errors occur in calculated CBV. These data indicate that C 15 O may be used as a tracer for CBV measurement provided that emission data collection commences at approximately 120 s after inhalation. Strict quality control measures must be maintained to minimize the contamination of administered C 15 O with 15 O-labeled CO 2

  16. Imaging of the dopaminergic neurotransmission system using single-photon emission tomography and positron emission tomography in patients with parkinsonism

    International Nuclear Information System (INIS)

    Booij, J.; Tissingh, G.; Winogrodzka, A.; Royen, E.A. van

    1999-01-01

    Parkinsonism is a feature of a number of neurodegenerative diseases, including Parkinson's disease, multiple system atrophy and progressive supranuclear palsy. The results of post-mortem studies point to dysfunction of the dopaminergic neurotransmitter system in patients with parkinsonism. Nowadays, by using single-photon emission tomography (SPET) and positron emission tomography (PET) it is possible to visualise both the nigrostriatal dopaminergic neurons and the striatal dopamine D 2 receptors in vivo. Consequently, SPET and PET imaging of elements of the dopaminergic system can play an important role in the diagnosis of several parkinsonian syndromes. This review concentrates on findings of SPET and PET studies of the dopaminergic neurotransmitter system in various parkinsonian syndromes. (orig.)

  17. 18F-AV-1451 positron emission tomography in Alzheimer's disease and progressive supranuclear palsy.

    Science.gov (United States)

    Passamonti, Luca; Vázquez Rodríguez, Patricia; Hong, Young T; Allinson, Kieren S J; Williamson, David; Borchert, Robin J; Sami, Saber; Cope, Thomas E; Bevan-Jones, W Richard; Jones, P Simon; Arnold, Robert; Surendranathan, Ajenthan; Mak, Elijah; Su, Li; Fryer, Tim D; Aigbirhio, Franklin I; O'Brien, John T; Rowe, James B

    2017-03-01

    The ability to assess the distribution and extent of tau pathology in Alzheimer's disease and progressive supranuclear palsy in vivo would help to develop biomarkers for these tauopathies and clinical trials of disease-modifying therapies. New radioligands for positron emission tomography have generated considerable interest, and controversy, in their potential as tau biomarkers. We assessed the radiotracer 18F-AV-1451 with positron emission tomography imaging to compare the distribution and intensity of tau pathology in 15 patients with Alzheimer's pathology (including amyloid-positive mild cognitive impairment), 19 patients with progressive supranuclear palsy, and 13 age- and sex-matched controls. Regional analysis of variance and a support vector machine were used to compare and discriminate the clinical groups, respectively. We also examined the 18F-AV-1451 autoradiographic binding in post-mortem tissue from patients with Alzheimer's disease, progressive supranuclear palsy, and a control case to assess the 18F-AV-1451 binding specificity to Alzheimer's and non-Alzheimer's tau pathology. There was increased 18F-AV-1451 binding in multiple regions in living patients with Alzheimer's disease and progressive supranuclear palsy relative to controls [main effect of group, F(2,41) = 17.5, P AV-1451 binding was significantly increased in patients with Alzheimer's disease, relative to patients with progressive supranuclear palsy and with control subjects, in the hippocampus and in occipital, parietal, temporal, and frontal cortices (t's > 2.2, P's AV-1451 binding was elevated in the midbrain (t = 2.1, P AV-1451 uptake in the putamen, pallidum, thalamus, midbrain, and in the dentate nucleus of the cerebellum (t's > 2.7, P's AV-1451 strongly bound to Alzheimer-related tau pathology, but less specifically in progressive supranuclear palsy. 18F-AV-1451 binding to the basal ganglia was strong in all groups in vivo. Postmortem histochemical staining showed absence of

  18. T cell homing to tumors detected by 3D-coordinated positron emission tomography and magnetic resonance imaging

    DEFF Research Database (Denmark)

    Agger, Ralf; Petersen, Mikkel; Petersen, Charlotte Christie

    2007-01-01

    of magnetic resonance imaging with the high sensitivity and spatial accuracy of positron emission tomography. We have used this technique, together with determination of tissue radioactivity, flow cytometry, and microscopy, to characterize and quantitate the specific accumulation of transferred CD8+ T cells...... was determined by flow cytometry each day for 8 consecutive days after adoptive transfer. From low levels 1 day after injection, their number gradually increased until day 5 when an average of 3.3x10(6) SIINFEKL-specific cells per gram tumor tissue was found. By applying the combined positron emission tomography...

  19. Use of fluorine-18 fluorodeoxyglucose positron emission tomography in the detection of silent metastases from malignant melanoma

    DEFF Research Database (Denmark)

    Eigtved, A; Andersson, A P; Dahlstrøm, K

    2000-01-01

    Correct staging is crucial for the management and prognosis of patients with malignant melanoma. The aim of this prospective study was to compare staging by whole-body positron emission tomography using fluorine-18 fluorodeoxyglucose (18F-FDG) with staging by conventional methods. Thirty-eight pa......Correct staging is crucial for the management and prognosis of patients with malignant melanoma. The aim of this prospective study was to compare staging by whole-body positron emission tomography using fluorine-18 fluorodeoxyglucose (18F-FDG) with staging by conventional methods. Thirty...

  20. Effect of oral contrast agents on computed tomography-based positron emission tomography attenuation correction in dual-modality positron emission tomography/computed tomography imaging.

    Science.gov (United States)

    Antoch, Gerald; Jentzen, Walter; Freudenberg, Lutz S; Stattaus, Jorg; Mueller, Stefan P; Debatin, Jorg F; Bockisch, Andreas

    2003-12-01

    To evaluate the effect of iodine- and barium-based contrast agents on the computed tomography (CT)-based positron emission tomography (PET) attenuation correction in dual-modality PET/CT. Experiments were conducted on a Society of Nuclear Medicine/National Electrical Manufacturers Association-PET phantom equipped with cylinders containing [18F]-2-fluoro-2-desoxy-D-glucose. The main compartment was filled with iodine (0.5-10%), barium (0.5-50%), or water (negative control). The error in attenuation correction was determined by comparison of measured tracer quantities in the presence of contrast agents with expected quantities. Contrast agent attenuation was demonstrated to be comparable to in vivo conditions. The presence of contrast agents resulted in an overestimation of the intracylindrical activity concentration on PET images and overestimation directly related to contrast concentrations (iodine 5-38%; barium 15-580%). Iodine and barium concentrations in clinical use resulted in an activity overestimation of 20 +/- 1.8% for iodine and 21 +/- 2.9% for barium. An overestimation of the tracer activity concentration is to be expected in the presence of oral contrast agents, if PET attenuation correction is attained CT-based.

  1. Routine positron emission tomography and positron emission tomography/computed tomography in melanoma staging with positive sentinel node biopsy is of limited benefit.

    Science.gov (United States)

    Constantinidou, Anastasia; Hofman, Michael; O'Doherty, Michael; Acland, Katharine M; Healy, Ciaran; Harries, Mark

    2008-02-01

    Positron emission tomography (PET) is increasingly used for the staging and management of melanoma. The aim of this study was to evaluate the role of PET or PET/ computed tomography (CT) as a routine procedure in patients with positive sentinel node biopsy (SNB). Thirty patients with melanoma of Breslow thickness greater than 1 mm who had PET or PET/CT scans performed within 100 days after a positive SNB were reviewed retrospectively. Two patients (6%) had a positive PET scan, none of which were melanoma related. The first patient had a synchronous neuroendocrine thyroid tumour and the second patient had increased uptake in the chest wall, which proved to be old trauma. Lymph node dissection was positive in five cases (16%). With a median follow-up of 24 months, 21 patients remained disease free. In none of the 30 cases did the early PET scan after a positive SNB alter subsequent melanoma management. The role of PET scanning soon after a positive sentinel node biopsy seems to be of limited benefit. It is questionable whether any imaging is beneficial at this stage. The results of this review suggest that PET scanning might not be indicated for this group of patients.

  2. Bitemporal hypometabolism in Creutzfeldt-Jakob Disease measured by positron emission tomography with (F-18)2-fluorodeoxyglucose

    International Nuclear Information System (INIS)

    Friedland, R.P.; Budinger, T.F.; Prusiner, S.B.; Jagust, W.J.

    1984-01-01

    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 male subject with autopsy confirmed CJD using (F-18)2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. An x-ray computed tomographic study of the brain performed 4 days prior to PET was normal. In the PET study the frontal to temporal cortex difference of activity densities was 30% on the left and 12% on the right, reflecting temporal hypometabolism. The left-right temporal cortex difference of activity density was 25%, documenting marked hemispheric asymmetry. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer's Disease (AD) and are distinctly different from PET-FDG finding in patients with other dementing illnesses or in healthy aged subjects. Recent work has demonstrated extensive biological similarities between CJD, scrapie and AD. The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the hypothesis that AD is caused by a slow infectious (prion-like) pathogen

  3. Bitemporal hypometabolism in Creutzfeldt-Jakob Disease measured by positron emission tomography with (F-18)2-fluorodeoxyglucose

    Energy Technology Data Exchange (ETDEWEB)

    Friedland, R.P.; Budinger, T.F.; Prusiner, S.B.; Jagust, W.J.

    1984-01-01

    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 male subject with autopsy confirmed CJD using (F-18)2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. An x-ray computed tomographic study of the brain performed 4 days prior to PET was normal. In the PET study the frontal to temporal cortex difference of activity densities was 30% on the left and 12% on the right, reflecting temporal hypometabolism. The left-right temporal cortex difference of activity density was 25%, documenting marked hemispheric asymmetry. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer's Disease (AD) and are distinctly different from PET-FDG finding in patients with other dementing illnesses or in healthy aged subjects. Recent work has demonstrated extensive biological similarities between CJD, scrapie and AD. The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the hypothesis that AD is caused by a slow infectious (prion-like) pathogen.

  4. Reactivation of medial temporal lobe and occipital lobe during the retrieval of color information: A positron emission tomography study.

    Science.gov (United States)

    Ueno, Aya; Abe, Nobuhito; Suzuki, Maki; Hirayama, Kazumi; Mori, Etsuro; Tashiro, Manabu; Itoh, Masatoshi; Fujii, Toshikatsu

    2007-02-01

    It is widely accepted that memory traces of an event include various types of information about the content of the event and about the circumstances in which the individual experienced it. However, how these various types of information are stored and later retrieved is poorly understood. One hypothesis postulates that the retrieval of specific event information reactivates regions that were active during the encoding of this information, with the aid of binding functions of the medial temporal lobe (MTL) structures. We used positron emission tomography to identify the brain regions related to the encoding and retrieval of color information. Specifically, we assessed whether overlapping activity was found in both the MTL structures and color-related cortical regions during the encoding and retrieval of color information attached with meaningless shapes. During the study, subjects were asked to encode colored (red or green) and achromatic random shapes. At subsequent testing, subjects were presented with only achromatic shapes, which had been presented with or without colors during encoding, and were engaged in retrieval tasks of shapes and colors. Overlapping activity was found in the MTL and occipital lobe (the lingual and inferior occipital gyri) in the right hemisphere during the encoding and retrieval of meaningless shapes with color information compared with those without color information. Although there are some limitations to be considered, the present findings seem to support the view that the retrieval of specific event information is associated with reactivation of both the MTL structures and the regions involved during encoding of the information.

  5. Inhibition of [11C]mirtazapine binding by alpha2-adrenoceptor antagonists studied by positron emission tomography in living porcine brain

    DEFF Research Database (Denmark)

    Smith, Donald F; Dyve, Suzan; Minuzzi, Luciano

    2006-01-01

    Inhibition of [11C]mirtazapine binding by alpha2-adrenoceptor antagonists studied by positron emission tomography in living porcine brain......Inhibition of [11C]mirtazapine binding by alpha2-adrenoceptor antagonists studied by positron emission tomography in living porcine brain...

  6. Studies of discrete symmetries in a purely leptonic system using the Jagiellonian Positron Emission Tomograph

    Directory of Open Access Journals (Sweden)

    Moskal P.

    2016-01-01

    Full Text Available Discrete symmetries such as parity (P, charge-conjugation (C and time reversal (T are of fundamental importance in physics and cosmology. Breaking of charge conjugation symmetry (C and its combination with parity (CP constitute necessary conditions for the existence of the asymmetry between matter and antimatter in the observed Universe. The presently known sources of discrete symmetries violations can account for only a tiny fraction of the excess of matter over antimatter. So far CP and T symmetries violations were observed only for systems involving quarks and they were never reported for the purely leptonic objects. In this article we describe briefly an experimental proposal for the test of discrete symmetries in the decays of positronium atom which is made exclusively of leptons. The experiments are conducted by means of the Jagiellonian Positron Emission Tomograph (J-PET which is constructed from strips of plastic scintillators enabling registration of photons from the positronium annihilation. J-PET tomograph together with the positronium target system enable to measure expectation values for the discrete symmetries odd operators constructed from (i spin vector of the ortho-positronium atom, (ii momentum vectors of photons originating from the decay of positronium, and (iii linear polarization direction of annihilation photons. Linearly polarized positronium will be produced in the highly porous aerogel or polymer targets, exploiting longitudinally polarized positrons emitted by the sodium 22Na isotope. Information about the polarization vector of orthopositronium will be available on the event by event basis and will be reconstructed from the known position of the positron source and the reconstructed position of the orthopositronium annihilation. In 2016 the first tests and calibration runs are planned, and the data collection with high statistics will commence in the year 2017.

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

    International Nuclear Information System (INIS)

    Pozzo, Lorena

    2005-01-01

    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. Mechanisms for the recovery of aphasia following stroke. A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Warburton, E

    1998-07-01

    Language disorders following stroke are common and are a major source of distress and disability. Most patients show some recovery with time implying the potential for neuronal plasticity within the brain for recovery of language. The mechanisms underlying recovery are poorly understood, making strategies for speech therapy and further investigation of potential therapeutic agents difficult. These studies were designed to explore the cortical re-organisation which underlies at least some language recovery using positron emission tomography (PET). With the rapid developments in PET technology and advances in image data processing it is now well established that language tasks can be studied in terms of responses within brain regions, and interactions between regions. The results can be interpreted with reference to neuropsychological theory and models. Many language activation studies have been performed in the normal brain. Thestudies reported here concentrated on one behavioural task - the verbal fluency task - the strategy being to compare patterns of activation in normal subjects with those in recovered aphasic patients performing the same fluency task. In the first part of this thesis, a detailed PET study of a verb retrieval task was made using different control tasks in normal volunteers. The results show that this task engages a widespread network of regions, predominantly in the left hemisphere i.e. the dorsolateral temporal cortex, the inferolateral temporal cortex and inferior parietal cortex, an extensive area of the dorsolateral prefrontal cortex (LDLPFC), the anterior cingulate and the supplementary motor area (SMA). The experiments using different control tasks suggest that the dorsolateral temporal cortex is involved with auditory and lexical processing of the stimulus nouns and it is demonstrated that observation of an activation in this region is dependent on the particular control task used with the retrieval task. This explains discrepancies

  9. Mechanisms for the recovery of aphasia following stroke. A positron emission tomography study

    International Nuclear Information System (INIS)

    Warburton, E.

    1998-01-01

    Language disorders following stroke are common and are a major source of distress and disability. Most patients show some recovery with time implying the potential for neuronal plasticity within the brain for recovery of language. The mechanisms underlying recovery are poorly understood, making strategies for speech therapy and further investigation of potential therapeutic agents difficult. These studies were designed to explore the cortical re-organisation which underlies at least some language recovery using positron emission tomography (PET). With the rapid developments in PET technology and advances in image data processing it is now well established that language tasks can be studied in terms of responses within brain regions, and interactions between regions. The results can be interpreted with reference to neuropsychological theory and models. Many language activation studies have been performed in the normal brain. The studies reported here concentrated on one behavioural task - the verbal fluency task - the strategy being to compare patterns of activation in normal subjects with those in recovered aphasic patients performing the same fluency task. In the first part of this thesis, a detailed PET study of a verb retrieval task was made using different control tasks in normal volunteers. The results show that this task engages a widespread network of regions, predominantly in the left hemisphere i.e. the dorsolateral temporal cortex, the inferolateral temporal cortex and inferior parietal cortex, an extensive area of the dorsolateral prefrontal cortex (LDLPFC), the anterior cingulate and the supplementary motor area (SMA). The experiments using different control tasks suggest that the dorsolateral temporal cortex is involved with auditory and lexical processing of the stimulus nouns and it is demonstrated that observation of an activation in this region is dependent on the particular control task used with the retrieval task. This explains discrepancies

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

    International Nuclear Information System (INIS)

    Frank, Albert; Lefkowitz, David; Jaeger, Stanley; Gobar, Lisa; Sunderland, John; Gupta, Naresh; Scott, Walter; Mailliard, James; Lynch, Henry; Bishop, John; Thorpe, Patricia; Dewan, Naresh

    1995-01-01

    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

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

    International Nuclear Information System (INIS)

    Yen, C.K.; Budinger, T.F.

    1981-01-01

    Dynamic positron tomography of the brain with 82 Rb, obtained from a portable generator [ 82 Sr (25 days) -- 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 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 82 Rb and positron emission tomography and corroborated by the accumulation of 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

  12. Anti-amyloid-β-mediated positron emission tomography imaging in Alzheimer's disease mouse brains.

    Directory of Open Access Journals (Sweden)

    Daniel McLean

    Full Text Available Antibody-mediated imaging of amyloid β (Aβ in Alzheimer's disease (AD offers a promising strategy to detect and monitor specific Aβ species, such as oligomers, that have important pathological and therapeutic relevance. The major current limitation of antibodies as a diagnostic and imaging device is poor blood-brain-barrier permeability. A classical anti-Aβ antibody, 6E10, is modified with 10 kDa polyethylene glycol (PEG and a positron emitting isotope, Copper-64 (t(½ = 12.7 h, and intravenously delivered to the TgCRND8 mouse model of Alzheimer's disease. Modification of 6E10 with PEG (6E10-PEG increases accumulation of 6E10 in brain tissue in both TgCRND8 and wild type control animals. 6E10-PEG differentiates TgCRND8 animals from wild type controls using positron emission tomography (PET and provides a framework for using antibodies to detect pathology using non-invasive medical imaging techniques.

  13. Positron emission tomography of hepatic first-pass metabolism of ammonia in pig

    International Nuclear Information System (INIS)

    Keiding, S.; Munk, O.L.; Roelsgaard, K.; Bender, D.; Bass, L.

    2001-01-01

    Hepatic first-pass metabolism plays a key role in metabolic regulation and drug metabolism. Metabolic processes can be quantified in vivo by positron emission tomography scanning (PET). We wished to develop a PET technique to measure hepatic first-pass metabolism of ammonia. Seven anaesthetised pigs were given positron-labelled ammonia, 13 NH 3 , into the portal vein and into the vena cava as successive 2-min infusions followed by 22-min dynamic liver scanning. Vena cava infusion data were used to account for recirculation of tracer and metabolites following the portal vein infusion. The scan data were analysed by a model of sinusoidal zonation of ammonia metabolism with periportal urea formation and perivenous formation of glutamine. The hepatic extraction fraction of 13 NH 3 was 0.73±0.16 (mean±SD, n=7 pigs). Values of clearance of ammonia to urea and to glutamine were obtained, as were rate constants for washout of these two metabolites. Overall, the modelling showed half of the ammonia uptake to be converted to urea and half to glutamine. The washout rate constant for glutamine was about one-tenth of that for urea. We conclude that hepatic first-pass metabolism of ammonia was successfully assessed by PET. (orig.)

  14. Development of a treatment planning system for BNCT based on positron emission tomography data: preliminary results

    Science.gov (United States)

    Cerullo, N.; Daquino, G. G.; Muzi, L.; Esposito, J.

    2004-01-01

    Present standard treatment planning (TP) for glioblastoma multiforme (GBM - a kind of brain tumor), used in all boron neutron capture therapy (BNCT) trials, requires the construction (based on CT and/or MRI images) of a 3D model of the patient head, in which several regions, corresponding to different anatomical structures, are identified. The model is then employed by a computer code to simulate radiation transport in human tissues. The assumption is always made that considering a single value of boron concentration for each specific region will not lead to significant errors in dose computation. The concentration values are estimated "indirectly", on the basis of previous experience and blood sample analysis. This paper describes an original approach, with the introduction of data on the in vivo boron distribution, acquired by a positron emission tomography (PET) scan after labeling the BPA (borono-phenylalanine) with the positron emitter 18F. The feasibility of this approach was first tested with good results using the code CARONTE. Now a complete TPS is under development. The main features of the first version of this code are described and the results of a preliminary study are presented. Significant differences in dose computation arise when the two different approaches ("standard" and "PET-based") are applied to the TP of the same GBM case.

  15. Positron emission tomography/computed tomography surveillance in patients with Hodgkin lymphoma in first remission has a low positive predictive value and high costs.

    Science.gov (United States)

    El-Galaly, Tarec Christoffer; Mylam, Karen Juul; Brown, Peter; Specht, Lena; Christiansen, Ilse; Munksgaard, Lars; Johnsen, Hans Erik; Loft, Annika; Bukh, Anne; Iyer, Victor; Nielsen, Anne Lerberg; Hutchings, Martin

    2012-06-01

    The value of performing post-therapy routine surveillance imaging in patients with Hodgkin lymphoma is controversial. This study evaluates the utility of positron emission tomography/computed tomography using 2-[18F]fluoro-2-deoxyglucose for this purpose and in situations with suspected lymphoma relapse. We conducted a multicenter retrospective study. Patients with newly diagnosed Hodgkin lymphoma achieving at least a partial remission on first-line therapy were eligible if they received positron emission tomography/computed tomography surveillance during follow-up. Two types of imaging surveillance were analyzed: "routine" when patients showed no signs of relapse at referral to positron emission tomography/computed tomography, and "clinically indicated" when recurrence was suspected. A total of 211 routine and 88 clinically indicated positron emission tomography/computed tomography studies were performed in 161 patients. In ten of 22 patients with recurrence of Hodgkin lymphoma, routine imaging surveillance was the primary tool for the diagnosis of the relapse. Extranodal disease, interim positron emission tomography-positive lesions and positron emission tomography activity at response evaluation were all associated with a positron emission tomography/computed tomography-diagnosed preclinical relapse. The true positive rates of routine and clinically indicated imaging were 5% and 13%, respectively (P = 0.02). The overall positive predictive value and negative predictive value of positron emission tomography/computed tomography were 28% and 100%, respectively. The estimated cost per routine imaging diagnosed relapse was US$ 50,778. Negative positron emission tomography/computed tomography reliably rules out a relapse. The high false positive rate is, however, an important limitation and a confirmatory biopsy is mandatory for the diagnosis of a relapse. With no proven survival benefit for patients with a pre-clinically diagnosed relapse, the high costs and low

  16. 18F-fluoro-2-deoxyglucose positron emission tomography-negative endocarditis lenta caused by Bartonella henselae

    NARCIS (Netherlands)

    Sankatsing, Sanjay U. C.; Kolader, Marion-Eliëtte; Bouma, Berto J.; Bennink, Roel J.; Verberne, Hein J.; Ansink, Tieneke M.; Visser, Caroline E.; van der Meer, Jan T. M.

    2011-01-01

    It has been suggested that 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) might serve as a tool for the often difficult diagnosis of infective endocarditis. The case is described of a patient with a Bartonella henselae endocarditis with a negative FDG-PET. This case report

  17. The value of positron emission tomography/computed tomography for evaluating metastatic disease in patients with pancreatic cancer.

    Science.gov (United States)

    Kim, Mi-Jin; Lee, Kwang Hyuck; Lee, Kyu Taek; Lee, Jong Kyun; Ku, Bon-Ho; Oh, Cho-Rong; Heo, Jin Seok; Choi, Seong-Ho; Choi, Dong Wook

    2012-08-01

    Routine application of positron emission tomography/computed tomography (PET/CT) for pancreatic cancer staging remains a controversial approach. The purpose of this study was to reassess the clinical impact of PET/CT for the detection of distant metastasis of pancreatic cancer. From January 2006 to June 2009, 125 patients with histologically proven pancreatic cancer that had undergone PET/CT at our hospital were retrospectively reviewed. To evaluate the clinical efficacy of PET/CT on the management plan, the post-PET/CT management plans were compared with the pre-PET/CT management plans. After the conventional staging workup, we determined that 76 patients (60.8%) had resectable lesions, whereas 48 patients had unresectable lesions. One patient underwent explorative laparotomy due to equivocal resectability. Positron emission tomography/computed tomography diagnosed distant metastasis in only 2 (2.6%) of the 76 patients with resectable lesions, and these patients did not undergo unnecessary surgical treatment. Complete resection was not performed in 8 of the 74 operative patients because they had distant metastasis detected during the operative procedure. Positron emission tomography/computed tomography diagnosed distant metastasis in 32 of the 44 patients with metastatic lesions that were histologically shown to have sensitivity of 72.7%. Positron emission tomography/computed tomography has a limited role in the evaluation of metastatic disease from pancreatic cancer.

  18. Incidental head and neck findings on 18F-fluoro-deoxy-glucose positron emission tomography computed tomography.

    Science.gov (United States)

    Williams, S P; Kinshuck, A J; Williams, C; Dwivedi, R; Wieshmann, H; Jones, T M

    2015-09-01

    The overlapping risk factors for lung and head and neck cancer present a definite risk of synchronous malignant pathology. This is the first study to specifically review incidental positron emission tomography computed tomography findings in the head and neck region in lung carcinoma patients. A retrospective review was performed of all lung cancer patients who underwent positron emission tomography computed tomography imaging over a five-year period (January 2008 - December 2012), identified from the Liverpool thoracic multidisciplinary team database. Six hundred and nine patients underwent positron emission tomography computed tomography imaging over this period. In 76 (12.5 per cent) scans, incidental regions of avid 18F-fluoro-deoxy-glucose uptake were reported in the head and neck region. In the 28 patients who were fully investigated, there were 4 incidental findings of malignancy. In lung cancer patients undergoing investigative positron emission tomography computed tomography scanning, a significant number will also present with areas of clinically significant 18F-fluoro-deoxy-glucose uptake in the head and neck region. Of these, at least 5 per cent may have an undiagnosed malignancy.

  19. Combined computed tomography and fluorodeoxyglucose positron emission tomography in the diagnosis of prosthetic valve endocarditis: a case series.

    Science.gov (United States)

    Bartoletti, Michele; Tumietto, Fabio; Fasulo, Giovanni; Giannella, Maddalena; Cristini, Francesco; Bonfiglioli, Rachele; Raumer, Luigi; Nanni, Cristina; Sanfilippo, Silvia; Di Eusanio, Marco; Scotton, Pier Giorgio; Graziosi, Maddalena; Rapezzi, Claudio; Fanti, Stefano; Viale, Pierluigi

    2014-01-13

    The diagnosis of prosthetic valve endocarditis is challenging. The gold standard for prosthetic valve endocarditis diagnosis is trans-esophageal echocardiography. However, trans-esophageal echocardiography may result in negative findings or yield images difficult to differentiate from thrombus in patients with prosthetic valve endocarditis. Combined computed tomography and fluorodeoxyglucose positron emission tomography is a potentially promising diagnostic tool for several infectious conditions and it has also been employed in patients with prosthetic valve endocarditis but data are still scant. We reviewed the charts of 6 patients with prosthetic aortic valves evaluated for suspicion of prosthetic valve endocarditis, at two different hospital, over a 3-year period. We found 3 patients with early-onset PVE cases and blood cultures yielding Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus lugdunensis, respectively; and 3 late-onset cases in the remaining 3 patients with isolation in the blood of Streptococcus bovis, Candida albicans and P. aeruginosa, respectively. Initial trans-esophageal echocardiography was negative in all the patients, while fluorodeoxyglucose positron emission tomography showed images suspicious for prosthetic valve endocarditis. In 4 out of 6 patients valve replacement was done with histology confirming the prosthetic valve endocarditis diagnosis. After an adequate course of antibiotic therapy fluorodeoxyglucose positron emission tomography showed resolution of prosthetic valve endocarditis in all the patients. Our experience confirms the potential role of fluoroseoxyglucose positron emission tomography in the diagnosis and follow-up of prosthetic valve endocarditis.

  20. Levodopa pharmacokinetic-pharmacodynamic modeling and 6-[F-18]levodopa positron emission tomography in patients with Parkinson's disease

    NARCIS (Netherlands)

    Dietz, M; Harder, S; Graff, J; Kunig, G; Vontobel, P; Leenders, KL; Baas, H

    Objective: Parameters of a pharmacokinetic-pharmacodynamic (PK-PD) model of levodopa have been claimed to reflect the magnitude of the dopaminergic deficit in patients with Parkinson's disease. The aim of this study was to correlate such parameters with positron emission tomography (PET) with

  1. Thalamic glucose metabolism in temporal lobe epilepsy measured with 18F-FDG positron emission tomography (PET)

    NARCIS (Netherlands)

    Khan, N; Leenders, KL; Hajek, M; Maguire, P; Missimer, J; Wieser, HG

    1997-01-01

    Thalamic glucose metabolism has been studied in 24 patients suffering from temporal lobe epilepsy (TLE) using interictal F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET). A total of 17 patients had a unilateral TL seizure onset, 11 of these patients had a mesial temporal lobe

  2. 18F-2-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography in Staging of Locally Advanced Breast Cancer

    NARCIS (Netherlands)

    Hoeven, J.J.M. van der; Krak, N.C.; Hoekstra, O.S.; Comans, E.F.I.; Boom, R.P.A.; Geldere, D. van; Meijer, S.; Wall, E. van der; Buter, J.; Pinedo, H.M.; Teule, G.J.J.; Lammertsma, A.A.

    2004-01-01

    PURPOSE To prospectively evaluate the effect of adding whole-body 18F-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) to conventional screening for distant metastases in patients with locally advanced breast cancer (LABC). PATIENTS AND METHODS All women with LABC referred for

  3. Report of two cases of fluorodeoxyglucose positron emission tomography/computed tomography appearance of hibernoma: A rare benign tumor

    International Nuclear Information System (INIS)

    Agrawal, Archi; Kembhavi, Seema; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2014-01-01

    False-positive findings are commonly seen in positron emission tomography computed tomography imaging. One of the most common false positive finding is uptake of fluorodeoxyglucose in brown adipose tissue. Herein, we report two cases with incidentally detected hibernomas-a brown fat containing tumor with metabolic activity

  4. Unusual sites of metastatic recurrence of osteosarcoma detected on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

    International Nuclear Information System (INIS)

    Kabnurkar, Rasika; Agrawal, Archi; Rekhi, Bharat; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2015-01-01

    Osteosarcoma (OS) is the most common nonhematolymphoid primary bone malignancy characterized by osteoid or new bone formation. Lungs and bones are the most common sites of metastases. We report a case where unusual sites of the soft tissue recurrence from OS were detected on restaging fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography scan done post 6 years of disease free interval

  5. Experimental validation of granular dynamics simulations of gas-fluidised beds with homogeneous inflow conditions using Positron Emission Particle Tracking

    NARCIS (Netherlands)

    Hoomans, B.P.B.; Kuipers, J.A.M.; Mohd Salleh, M.; Seville, J.P.

    2001-01-01

    A hard-sphere granular dynamics model of a two-dimensional gas-fluidised bed was experimentally validated using Positron Emission Particle Tracking (PEPT). In the model the Newtonian equations of motion are solved for each solid particle while taking into account the particle¿particle and

  6. T cell homing to tumors detected by 3D-coordinated positron emission tomography and magnetic resonance imaging

    DEFF Research Database (Denmark)

    Agger, Ralf; Petersen, Mikkel; Petersen, Charlotte Christie

    2007-01-01

    of magnetic resonance imaging with the high sensitivity and spatial accuracy of positron emission tomography. We have used this technique, together with determination of tissue radioactivity, flow cytometry, and microscopy, to characterize and quantitate the specific accumulation of transferred CD8+ T cells...

  7. Regional myocardial oxygen consumption estimated by carbon-11 acetate and positron emission tomography before and after repetitive ischemia

    DEFF Research Database (Denmark)

    Kofoed, K F; Hansen, P R; Holm, S

    2011-01-01

    Preserved myocardial oxygen consumption estimated by carbon 11-acetate and positron emission tomography (PET) in myocardial regions with chronic but reversibly depressed contractile function in patients with ischemic heart disease have been suggested to be caused by repeated short episodes of acu...... myocardial ischemia. To evaluate this hypothesis myocardial 11C-acetate PET imaging was performed before and after acute repetitive myocardial ischemia....

  8. Use of a high density lead glass tubing projection chamber in positron emission tomography and in high energy physics

    International Nuclear Information System (INIS)

    Conti, M.; Guerra, A.D.; Habel, R.; Mulera, T.; Perez-Mendez, V.; Schwartz, G.

    1985-10-01

    We describe the principle of operation of a high density Projection Chamber, in which the converter/radiator and drift field shaping structures are combined in the form of high density (5 to 6 g/cm 3 ) lead glass tubing. The main applications of this type of detector to Medical Physics (Positron Emission Tomography) and High Energy Physics (Electromagnetic Calorimetry) are discussed

  9. Effects of high amphetamine dose on mood and cerebral glucose metabolism in normal volunteers using positron emission tomography (PET)

    NARCIS (Netherlands)

    Vollenweider, FX; Maguire, RP; Leenders, KL; Mathys, K; Angst, J

    1998-01-01

    The effects of high euphorigenic doses of D-amphetamine (0.9-1.0 mg/kg p.o.) on regional cerebral glucose metabolism (rCMRglu) and psychological measures were investigated in 10 healthy human volunteers using a within-subject design and [F-18]-fluorodeoxygrucose positron emission tomography

  10. Recommendations for measurement of tumour vascularity with positron emission tomography in early phase clinical trials

    Energy Technology Data Exchange (ETDEWEB)

    Aboagye, Eric O.; Kenny, Laura M.; Myers, Melvyn [Imperial College London, Department of Surgery and Cancer, Faculty of Medicine, London (United Kingdom); Gilbert, Fiona J. [University of Cambridge, Radiology Department, Cambridge (United Kingdom); Fleming, Ian N. [University of Aberdeen, NCRI PET Research Network, Aberdeen Bioimaging Centre, Aberdeen (United Kingdom); Beer, Ambros J. [Technische Universitaet Munchen, Klinikum rechts der Isar, Department of Nuclear Medicine, Munich (Germany); Cunningham, Vincent J. [University of Aberdeen, Institute of Medical Sciences, Aberdeen (United Kingdom); Marsden, Paul K. [St. Thomas' Hospital, Division of Imaging Sciences, PET Imaging Centre, London (United Kingdom); Visvikis, Dimitris [INSERM National Institute of Health and Clinical Sciences LaTIM, CHU Morvan, Brest (France); Gee, Antony D. [St. Thomas' Hospital, Division of Imaging Sciences, The Rayne Institute, London (United Kingdom); Groves, Ashley M. [University College London, University College Hospital, Institute of Nuclear Medicine, London (United Kingdom); Cook, Gary J. [St. Thomas' Hospital, KCL Division of Imaging, Sciences and Biomedical Engineering, PET Imaging Centre, London (United Kingdom); Kinahan, Paul E. [University of Washington, 222 Old Fisheries Center (FIS), Box 357987, Seattle, WA (United States); Clarke, Larry [Cancer Imaging Program, Imaging Technology Development Branch, Rockville, MD (United States)

    2012-07-15

    The evaluation of drug pharmacodynamics and early tumour response are integral to current clinical trials of novel cancer therapeutics to explain or predict long term clinical benefit or to confirm dose selection. Tumour vascularity assessment by positron emission tomography could be viewed as a generic pharmacodynamic endpoint or tool for monitoring response to treatment. This review discusses methods for semi-quantitative and quantitative assessment of tumour vascularity. The radioligands and radiotracers range from direct physiological functional tracers like [{sup 15}O]-water to macromolecular probes targeting integrin receptors expressed on neovasculature. Finally we make recommendations on ways to incorporate such measurements of tumour vascularity into early clinical trials of novel therapeutics. (orig.)

  11. Regional cerebral glucose consumption measured by positron emission tomography in patients with Wilson's disease

    International Nuclear Information System (INIS)

    Kuwert, T.; Scholz, D.; Milz, M.; Herzog, H.; Feinendegen, L.E.; Hefter, H.; Weiss, P.; Arendt, G.; Loken, M.; Minnesota Univ., Minneapolis, MN; Hennerici, M.

    1992-01-01

    Using positron emission tomography (PET), the regional cerebral metabolic rate of glucose consumption (rCMRGlc) was measured in 14 patients with Wilson's disease (WD) and 23 normal subjects. In WD patients, cerebellar, striatal and - to a lesser extent - cortical and thalamic rCMRGlc were significantly decreased compared with controls. Striatal rCMRGlc was significantly reduced in those 4 patients who had recently started decoppering therapy as compared with striatal rCMRGlc measured in those 10 patients with longer duration of medication. Caudate rCMRGlc correlated significantly with various signs of extrapyramidal dysfunction. Cerebellar, thalamic and cortical rCMRGlc correlated significantly with the severity of pyramidal signs. These data indicate that the PET measurement of rCMRGlc may be a useful tool to evaluate cerebral involvement in WD and to monitor the response to treatment. (orig.)

  12. Nicotine Blocks Brain Estrogen Synthase (Aromatase): In Vivo Positron Emission Tomography Studies in Female Baboons

    Energy Technology Data Exchange (ETDEWEB)

    Biegon, A.; Biegon, A.; Kim, S.-W.; Logan, J.; Hooker, J.M.; Muench, L.; Fowler, J.S.

    2010-01-12

    Cigarette smoking and nicotine have complex effects on human physiology and behavior, including some effects similar to those elicited by inhibition of aromatase, the last enzyme in estrogen biosynthesis. We report the first in vivo primate study to determine whether there is a direct effect of nicotine administration on brain aromatase. Brain aromatase availability was examined with positron emission tomography and the selective aromatase inhibitor [{sup 11}C]vorozole in six baboons before and after exposure to IV nicotine at .015 and .03 mg/kg. Nicotine administration produced significant, dose-dependent reductions in [{sup 11}C]vorozole binding. The amygdala and preoptic area showed the largest reductions. Plasma levels of nicotine and its major metabolite cotinine were similar to those found in cigarette smokers. Nicotine interacts in vivo with primate brain aromatase in regions involved in mood, aggression, and sexual behavior.

  13. Sparse representation and dictionary learning penalized image reconstruction for positron emission tomography.

    Science.gov (United States)

    Chen, Shuhang; Liu, Huafeng; Shi, Pengcheng; Chen, Yunmei

    2015-01-21

    Accurate and robust reconstruction of the radioactivity concentration is of great importance in positron emission tomography (PET) imaging. Given the Poisson nature of photo-counting measurements, we present a reconstruction framework that integrates sparsity penalty on a dictionary into a maximum likelihood estimator. Patch-sparsity on a dictionary provides the regularization for our effort, and iterative procedures are used to solve the maximum likelihood function formulated on Poisson statistics. Specifically, in our formulation, a dictionary could be trained on CT images, to provide intrinsic anatomical structures for the reconstructed images, or adaptively learned from the noisy measurements of PET. Accuracy of the strategy with very promising application results from Monte-Carlo simulations, and real data are demonstrated.

  14. Sparse representation and dictionary learning penalized image reconstruction for positron emission tomography

    Science.gov (United States)

    Chen, Shuhang; Liu, Huafeng; Shi, Pengcheng; Chen, Yunmei

    2015-01-01

    Accurate and robust reconstruction of the radioactivity concentration is of great importance in positron emission tomography (PET) imaging. Given the Poisson nature of photo-counting measurements, we present a reconstruction framework that integrates sparsity penalty on a dictionary into a maximum likelihood estimator. Patch-sparsity on a dictionary provides the regularization for our effort, and iterative procedures are used to solve the maximum likelihood function formulated on Poisson statistics. Specifically, in our formulation, a dictionary could be trained on CT images, to provide intrinsic anatomical structures for the reconstructed images, or adaptively learned from the noisy measurements of PET. Accuracy of the strategy with very promising application results from Monte-Carlo simulations, and real data are demonstrated.

  15. Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.C.; Hagman, J.; Buchsbaum, M.S.; Blinder, B.; Derrfler, M.; Tai, W.Y.; Hazlett, E.; Sicotte, N. (Univ. of California, Irvine (USA))

    1990-03-01

    Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using (18F)-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion that bulimia is a diagnostic grouping distinct from these disorders.

  16. Caffeine and human cerebral blood flow: A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, O.G.; Modell, J.G.; Hariharan, M. (Univ. of Michigan Medical Center, Ann Arbor (USA))

    1990-01-01

    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 p{sub a}CO{sub 2} and increased systolic blood pressure significantly; the change in p{sub a}CO{sub 2} 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.

  17. Present results and perspectives of positron emission tomography in oncology and radiotherapy

    International Nuclear Information System (INIS)

    Lonneux, M.; Sibomana, M.; Pauwels, S.; Gregoire, V.

    1999-01-01

    Positron emission tomography (PET) is one of the most promising diagnostic procedures in oncology. Using the glucose analogue fluorodeoxyglucose, PET produces whole-body images and is highly sensitive for tumor diagnosis and staging. We review three particular clinical situations in which PET-FDG has proven not only its diagnostic accuracy, but also its impact on patient management, i.e., the staging of non-small cell lung cancer, diagnosis and staging of colo-rectal cancer and head and neck cancer recurrence. Image registration yields anatomic-metabolic images that could be used as additional information for the determination of radiation fields. Tracer and technical issues remain to be solved before PET can be routinely used for that purpose. (authors)

  18. Sub-core permeability and relative permeability characterization with Positron Emission Tomography

    Science.gov (United States)

    Zahasky, C.; Benson, S. M.

    2017-12-01

    This study utilizes preclinical micro-Positron Emission Tomography (PET) to image and quantify the transport behavior of pulses of a conservative aqueous radiotracer injected during single and multiphase flow experiments in a Berea sandstone core with axial parallel bedding heterogeneity. The core is discretized into streamtubes, and using the micro-PET data, expressions are derived from spatial moment analysis for calculating sub-core scale tracer flux and pore water velocity. Using the flux and velocity data, it is then possible to calculate porosity and saturation from volumetric flux balance, and calculate permeability and water relative permeability from Darcy's law. Full 3D simulations are then constructed based on this core characterization. Simulation results are compared with experimental results in order to test the assumptions of the simple streamtube model. Errors and limitations of this analysis will be discussed. These new methods of imaging and sub-core permeability and relative permeability measurements enable experimental quantification of transport behavior across scales.

  19. Positron Emission Tomography in clinical research and clinical diagnosis: tracer modelling and radioreceptors

    International Nuclear Information System (INIS)

    Beckers, C.; Goffinet, A.; Bol, A.

    1989-01-01

    Positron emission tomography (PET) allows noninvasive studies of different metabolic pathways in man in a unique way. Human biochemistry can now be studied using physiological tracers like glucose or oxygen; promising investigations are now underway with various neurotransmitters. The aim of this workshop, sponsored by the European Community, has been to convene a group of experts to discuss more deeply the problems related to the study of receptors and energy metabolism, and this particularly in relationship with the compartmental analysis and the modelling of the data. Up to now, these have mostly been accumulated for the brain and heart. Oncology is now a growing field of interest and more applications are certain to arise in the near future. The papers included in this volume summarize the main points discussed during the workshop. (author). refs.; figs.; tabs

  20. Deconvolution based attenuation correction for time-of-flight positron emission tomography

    Science.gov (United States)

    Lee, Nam-Yong

    2017-10-01

    For an accurate quantitative reconstruction of the radioactive tracer distribution in positron emission tomography (PET), we need to take into account the attenuation of the photons by the tissues. For this purpose, we propose an attenuation correction method for the case when a direct measurement of the attenuation distribution in the tissues is not available. The proposed method can determine the attenuation factor up to a constant multiple by exploiting the consistency condition that the exact deconvolution of noise-free time-of-flight (TOF) sinogram must satisfy. Simulation studies shows that the proposed method corrects attenuation artifacts quite accurately for TOF sinograms of a wide range of temporal resolutions and noise levels, and improves the image reconstruction for TOF sinograms of higher temporal resolutions by providing more accurate attenuation correction.

  1. Assessment of pancreatic blood flow with positron emission tomography and oxygen-15 water

    International Nuclear Information System (INIS)

    Kubo, Soichi; Yamamoto, Kazutaka; Magata, Yasutaka; Iwasaki, Yasushi; Tamaki, Nagara; Yonekura, Yoshiharu; Konishi, Junji

    1991-01-01

    Dynamic positron emission tomography (PET) was performed following an intravenous bolus injection of 15 O-water for the assessment of regional pancreatic blood flow in 4 normal volunteers and 11 patients with pancreatic cancer. The regional pancreatic blood flow index (PFI) was calculated by the autoradiographic method assuming the time-activity curves of the aorta as an input function. The mean PFI value was 0.514±0.098 in the normal pancreas but it was decrease in the pancreatic cancer (0.247±0.076) (p 15 O-water permits quantitative assessment of pancreatic blood flow which decreased in both pancreatic cancer and concomitant obstructive pancreatitis distal to the tumor. (author)

  2. 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....

  3. Short time bacterial endotoxins test for positron emission tomography by means of positively charged filters

    Energy Technology Data Exchange (ETDEWEB)

    Nakazawa, Nobuhiro; Wakita, Kazuo [Nishijin Hospital, Kyoto (Japan); Mineura, Katsuyoshi [Kyoto Prefectural Univ. of Medicine (Japan)] (and others)

    2002-11-01

    Positron emission tomography (PET) radiotracers have very short physical half-lives. It is hard to complete a bacterial endotoxins test prior to release from medical institutes. For endotoxin quantitative determination, limulus amebocyte lysate (LAL) reagent and kinetic-turbidimetry system were previously developed. We investigated the possibility of a short time test by means of positively charged filters. As a result of this study, the effects of positively charged filters on endotoxin removal were over 99.5% for [{sup 18}F]FDG and [{sup 18}F]NaF, which were contaminated with the indicated concentration of endotoxin. Combining this filter and the kinetic-turbidimetric method, it was possible to complete a bacterial endotoxins test in 5 min prior to the patient's administration. This test should be required prior to release for PET radiopharmaceutical quality control. It has been suggested that this combination is a good method for this purpose. (author)

  4. Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    Directory of Open Access Journals (Sweden)

    Erdem Sürücü

    2016-10-01

    Full Text Available A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT.

  5. Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    Science.gov (United States)

    Sürücü, Erdem; Demir, Yusuf; Dülger, Ahmet C.; Batur, Abdüssamed; Ölmez, Şehmus; Kitapçı, Mehmet T.

    2016-01-01

    A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT) scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG) uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT. PMID:27751978

  6. Image properties of list mode likelihood reconstruction for a rectangular positron emission mammography with DOI measurements

    International Nuclear Information System (INIS)

    Qi, Jinyi; Klein, Gregory J.; Huesman, Ronald H.

    2000-01-01

    A positron emission mammography scanner is under development at our Laboratory. The tomograph has a rectangular geometry consisting of four banks of detector modules. For each detector, the system can measure the depth of interaction information inside the crystal. The rectangular geometry leads to irregular radial and angular sampling and spatially variant sensitivity that are different from conventional PET systems. Therefore, it is of importance to study the image properties of the reconstructions. We adapted the theoretical analysis that we had developed for conventional PET systems to the list mode likelihood reconstruction for this tomograph. The local impulse response and covariance of the reconstruction can be easily computed using FFT. These theoretical results are also used with computer observer models to compute the signal-to-noise ratio for lesion detection. The analysis reveals the spatially variant resolution and noise properties of the list mode likelihood reconstruction. The theoretical predictions are in good agreement with Monte Carlo results

  7. Scintillation photon detection and event selection in high resolution positron emission tomography

    International Nuclear Information System (INIS)

    Turko, B.T.; Zizka, G.; Lo, C.C.; Leskovar, B.; Cahoon, J.L.; Huesman, R.H.; Derenzo, S.E.; Geyer, A.B.; Budinger, T.F.

    1987-01-01

    The scintillation photon detection and event selection subsystem for the high spatial resolution Donner 600-channel positron emission tomograph is described. The tomograph spatial resolution of better than 3.0 mm, FWHM, is obtained by using 600 closely-packed bismuth germanate 3 mm thick scintillation detectors. Each detector has its own 13.5 mm diameter photomultiplier and event selection channel, consisting of two fast pulse amplifiers, a charge integrator, a differential pulse height discriminator and precision time delay for event strobing. The event selection channel is capable of starting a timing cycle from the first photoelectric emitted from the photocathode. It is also capable of discriminating between true events and noise and of eliminating events occurring simultaneously in two adjacent channels. Adjustments of the event strobing time and two discriminator levels are performed by a computer

  8. Positron emission tomography / ultrasound fusion technique in patients with malignant melanoma

    International Nuclear Information System (INIS)

    Freesmeyer, Martin; Winkens, Thomas; Elsner, Peter; Goetze, Steven; Kaatz, Martin

    2015-01-01

    18 F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT is commonly used to assess tumour recurrence in high-risk patients with malignant melanoma (MM). However, results can be ambiguous either because of the CT's insufficient soft-tissue contrast or non-specific FDG accumulation caused by inflammation. Ultrasound (US) can provide additional morphologic information that is superior to CT. For precisely combining PET and US findings, we used a real-time fusion technique based on navigated US (PET/US fusion). Here, we describe our results from patients where PET/US fusion proved helpful in differentiating unclear PET/CT findings. This fusion technique is likely to be helpful for decision making in MM patients and biopsy guidance.

  9. Intraprocedural yttrium-90 positron emission tomography/CT for treatment optimization of yttrium-90 radioembolization.

    Science.gov (United States)

    Bourgeois, Austin C; Chang, Ted T; Bradley, Yong C; Acuff, Shelley N; Pasciak, Alexander S

    2014-02-01

    Radioembolization with yttrium-90 ((90)Y) microspheres relies on delivery of appropriate treatment activity to ensure patient safety and optimize treatment efficacy. We report a case in which (90)Y positron emission tomography (PET)/computed tomography (CT) was performed to optimize treatment planning during a same-day, three-part treatment session. This treatment consisted of (i) an initial (90)Y infusion with a dosage determined using an empiric treatment planning model, (ii) quantitative (90)Y PET/CT imaging, and (iii) a secondary infusion with treatment planning based on quantitative imaging data with the goal of delivering a specific total tumor absorbed dose. © 2014 SIR Published by SIR All rights reserved.

  10. Usefulness of positron emission tomography (TEP) in the assessment of osteo-articular prosthesis

    International Nuclear Information System (INIS)

    Maldonado, A.; Suarez, J.P.; Dominguez, M.L.

    2004-01-01

    Joint arthroplasty is performed with increasing frequency as the population ages. Loosening or infection of the prosthesis is a relatively common event that can limit the lifetime of a prosthesis. Accuracy differentiation between aseptic and septic loosening of the prosthesis remains a challenge because of the consequences for patient management. Moreover, an early diagnosis of infected hip prosthesis is very important for optimal and cost-effective management. Various approaches have developed to visualize infection and inflammation by nuclear medicine techniques. Recently positron emission tomography (PET) with fluorine-l8 labelled 2 fluoro-2-deoxyglucose ( 18 F-FDG) has been shown to delineate infectious and inflammatory foci with high sensitivity owing to the increased glucose metabolism in inflammatory cells. In this paper we review the role of FDG-PET in this common differential diagnosis in patients with total knee and hip prostheses. Different patterns of FDG-PET interpretation have been described as wed as methodological aspects. (author)

  11. Interstitial brachytherapy for liver metastases and assessment of response by positron emission tomography: a case report

    Directory of Open Access Journals (Sweden)

    Goura Kishor Rath

    2010-10-01

    Full Text Available For liver metastases (LM, image guided percutaneous ablative procedures such as radiofrequency ablation (RFA, laser induced thermal therapy (LITT and trans-arterial chemo-embolisation (TACE are increasingly being used because they are relatively safer, less invasive and equally effective. CT scan guided interstitial brachytherapy (IBT with a single large dose of radiation by high dose rate (HDR brachytherapy is a novel technique of treating LM and has shown good results. Positron emission tomography (PET scan may provide better information for assessing the response toIBT procedures. We hereby report a case of LM that was treated by HDR IBT and PET scan was done in addition to CT scan for assessing the response.

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

    Directory of Open Access Journals (Sweden)

    Rasmus Sejersten Ripa

    2015-01-01

    Full Text Available 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.

  13. Towards factor analysis exploration applied to positron emission tomography functional imaging for breast cancer characterization

    International Nuclear Information System (INIS)

    Rekik, W.; Ketata, I.; Sellami, L.; Ben slima, M.; Ben Hamida, A.; Chtourou, K.; Ruan, S.

    2011-01-01

    This paper aims to explore the factor analysis when applied to a dynamic sequence of medical images obtained using nuclear imaging modality, Positron Emission Tomography (PET). This latter modality allows obtaining information on physiological phenomena, through the examination of radiotracer evolution during time. Factor analysis of dynamic medical images sequence (FADMIS) estimates the underlying fundamental spatial distributions by factor images and the associated so-called fundamental functions (describing the signal variations) by factors. This method is based on an orthogonal analysis followed by an oblique analysis. The results of the FADMIS are physiological curves showing the evolution during time of radiotracer within homogeneous tissues distributions. This functional analysis of dynamic nuclear medical images is considered to be very efficient for cancer diagnostics. In fact, it could be applied for cancer characterization, vascularization as well as possible evaluation of response to therapy.

  14. Comparison of kinetic models for data from a positron emission tomograph

    International Nuclear Information System (INIS)

    Coxson, P.G.; Huesman, R.H.; Lim, S.; Klein, G.J.; Reutter, B.W.; Budinger, T.F.

    1995-01-01

    The purpose of this research was to compare a physiological model of 82 Rb in the myocardium with two reduced order models with regard to their ability to assess physiological parameters of diagnostic significance. A three compartment physiological model of 82 Rb uptake in the myocardium was used to simulate kinetic region of interest data from a positron emission tomograph (PET). Simulations were generated for eight different blood flow rates reflecting the physiological range of interest. Two reduced order models which are commonly used with myocardial PET studies were fit to the simulated data and the parameters of the reduced order models were compared with the physiological parameters. Then all three models were fit to the simulated data with noise added. Monte Carlo simulations were used to evaluate and compare the diagnostic utility of the reduced order models

  15. Vasculitis assessment with [18F]F.D.G. positron emission tomography

    International Nuclear Information System (INIS)

    Liozon, E.; Monteil, J.

    2008-01-01

    [ 18 F]fluorodeoxyglucose ( 18 F.D.G.) positron emission tomography (PET) is a noninvasive metabolic imaging modality that is well suited to the assessment of activity and extent of large vessel vasculitis, such as giant cell arteritis and Takayasu arteritis. PET could be more effective than magnetic resonance imaging in detecting the earliest stages of vascular wall inflammation. The visual grading of vascular [ 18 F]F.D.G. uptake makes it possible to discriminate arteritis from atherosclerosis, providing therefore high specificity. High sensitivity can be achieved provided scanning is performed during active inflammatory phase, preferably before starting corticosteroid treatment. Large scale prospective studies are needed to determine the exact value of PET imaging in assessing the large vessel vasculitis outcome and response to immunosuppressive treatment

  16. Effect of gender on glucose utilization rates in healthy humans: A positron emission tomography study

    International Nuclear Information System (INIS)

    Miura, S.A.; Schapiro, M.B.; Grady, C.L.; Kumar, A.; Salerno, J.A.; Kozachuk, W.E.; Wagner, E.; Rapoport, S.I.; Horwitz, B.

    1990-01-01

    Positron emission tomography (PET) was used with 18fluorodeoxyglucose to see if gender differences in resting cerebral glucose utilization could be detected. Thirty-two healthy subjects (15 women and 17 men; age range: 21-38 yr) were examined using a high-resolution PET scanner to determine the regional cerebral metabolic rate for glucose (CMRglc) in 65 gray matter regions of interest. Whole brain CMRglc did not differ significantly between the two genders, nor did any of the regional CMRglc values. Only 1 of 65 ratios of regional-to-whole brain CMRglc differed significantly between men and women, which is consistent with chance. These results indicate that there are no differences in resting regional cerebral glucose utilization between young men and women

  17. Extensive Tattoos Mimicking Lymphatic Metastasis on Positron Emission Tomography Scan in a Patient With Cervical Cancer.

    Science.gov (United States)

    Grove, Narine; Zheng, Ma; Bristow, Robert E; Eskander, Ramez N

    2015-07-01

    Positron emission tomography (PET) fused with computed tomography (CT) imaging is common in the clinical assessment of patients with locally advanced cervical cancer. Limitations to the utilization and interpretation of PET-CT scans in patients with cervical cancer have been described, including false-positive findings secondary to tattoo ink. A 32-year-old woman presented with clinical stage 1B1 cervical cancer and extensive tattoos of the lower extremities. Preoperative PET-CT scan identified two ileac lymph nodes with increased fluorine-18-deoxyglucose uptake suspicious for metastatic disease. At the time of surgical resection, bilateral pigmented lymph nodes were identified with histologic examination showing deposition of tattoo ink and no malignant cells. Physicians should be cognizant of the possible effects of tattoos on PET-CT findings while counseling patients and formulating a treatment program.

  18. Prognostic Value of 18F-Fluorodeoxyglucose Positron Emission Tomography in Patients with Resectable Pancreatic Cancer

    Science.gov (United States)

    Choi, Hye Jin; Kang, Chang Moo; Lee, Woo Jung; Song, Si Young; Cho, Arthur; Yun, Mijin; Lee, Jong Doo; Kim, Joo Hang

    2013-01-01

    Purpose We evaluated the prognostic value of 18F-2-fluoro-2-deoxyglucose positron emission tomography (FDG PET) in patients with resectable pancreatic cancer. Materials and Methods We retrospectively reviewed the medical records of pancreatic cancer patients who underwent curative resection, which included 64 consecutive patients who had preoperative FDG PET scans. For statistical analysis, the maximal standardized uptake value (SUVmax) of primary pancreatic cancer was measured. Survival time was estimated by the Kaplan-Meier method, and Cox's proportional hazard model was used to determine whether SUVmax added new predictive information concerning survival together with known prognostic factors. p3.5) showed significantly shorter OS and DFS than the low SUVmax group. Multivariate analysis of OS and DFS showed that both high SUVmax and poor tumor differentiation were independent poor prognostic factors. Conclusion Our study showed that degree of FDG uptake was an independent prognostic factor in pancreatic cancer patients who underwent curative resection. PMID:24142641

  19. Positron emission tomography with [11C]-acetate for evaluation of myocardial oxidative metabolism. Clinical use

    International Nuclear Information System (INIS)

    Litvinova, I.S.; Litvinov, M.M.; Rozhkova, G.G.; Leont'eva, I.V.; Sebeleva, I.A.; Tumanyan, M.R.; Koledinskij, D.G.; Sukhorukov, V.S.

    2001-01-01

    The diagnostic potentials of positron emission tomography (PET) with [ 11 C]-acetate as applied to mitochondrial disorders in children with cardiomyopathies (CMP) are evaluated. PET examinations are performed in 17 patients of the mean age of 7.5 ± 3.1 years with CMP. A dynamic study with [ 11 C]-acetate is conducted to evaluate the Krebs cycle activity. The experiments have indicated to a fewer accumulation of [ 11 C]-acetate and to its slower clearance in the ischemic zone as compared with the normal myocardium. The Krebs cycle activity has been reduced. By means of PET with [ 11 C]-acetate the oxidation rate constant of the Krebs cycle and the [ 11 C]-acetate-activity clearance half-time can be quantified. This makes possible to assess the extent of oxidative metabolism malfunction, including the case of perfusion reduction [ru

  20. Image properties of list mode likelihood reconstruction for a rectangular positron emission mammography with DOI measurements

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Jinyi; Klein, Gregory J.; Huesman, Ronald H.

    2000-10-01

    A positron emission mammography scanner is under development at our Laboratory. The tomograph has a rectangular geometry consisting of four banks of detector modules. For each detector, the system can measure the depth of interaction information inside the crystal. The rectangular geometry leads to irregular radial and angular sampling and spatially variant sensitivity that are different from conventional PET systems. Therefore, it is of importance to study the image properties of the reconstructions. We adapted the theoretical analysis that we had developed for conventional PET systems to the list mode likelihood reconstruction for this tomograph. The local impulse response and covariance of the reconstruction can be easily computed using FFT. These theoretical results are also used with computer observer models to compute the signal-to-noise ratio for lesion detection. The analysis reveals the spatially variant resolution and noise properties of the list mode likelihood reconstruction. The theoretical predictions are in good agreement with Monte Carlo results.

  1. Regional cerebral glucose metabolic rate in human sleep assessed by positron emission tomography

    International Nuclear Information System (INIS)

    Buchsbaum, M.S.; Wu, J.; Hazlett, E.; Sicotte, N.; Bunney, W.E. Jr.; Gillin, J.C.

    1989-01-01

    The cerebral metabolic rate of glucose was measured during nighttime sleep in 36 normal volunteers using positron emission tomography and fluorine-18-labeled 2-deoxyglucose (FDG). In comparison to waking controls, subjects given FDG during non-rapid eye movement (NREM) sleep showed about a 23% reduction in metabolic rate across the entire brain. This decrease was greater for the frontal than temporal or occipital lobes, and greater for basal ganglia and thalamus than cortex. Subjects in rapid eye movement (REM) sleep tended to have higher cortical metabolic rates than walking subjects. The cingulate gyrus was the only cortical structure to show a significant increase in glucose metabolic rate in REM sleep in comparison to waking. The basal ganglia were relatively more active on the right in REM sleep and symmetrical in NREM sleep

  2. Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography.

    Science.gov (United States)

    Sürücü, Erdem; Demir, Yusuf; Dülger, Ahmet C; Batur, Abdüssamed; Ölmez, Şehmus; Kitapçı, Mehmet T

    2016-10-05

    A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT) scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG) uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT.

  3. Positron emission tomography suggests that the rate of progression of idiopathic parkinsonism is slow

    International Nuclear Information System (INIS)

    Bhatt, M.H.; Snow, B.J.; Martin, W.R.; Pate, B.D.; Ruth, T.J.; Calne, D.B.

    1991-01-01

    The authors performed sequential positron emission tomography scans with 6-[18F]fluoro-L-dopa in 9 patients with idiopathic parkinsonism and 7 age-matched normal control subjects to compare changes in the nigrostriatal dopaminergic pathway over time. The mean interval between the scans was 3.3 years for the group with idiopathic parkinsonism and 3.9 years for the control subjects. The scans were analyzed by calculating the ratio of striatal to background radioactivity. Both groups showed statistically significant reductions of striatal uptake over the interval. The rate of decrease was almost identical in each group (p = 0.6). They infer that the usual rate of loss of integrity of the dopaminergic nigrostriatal pathway in patients with idiopathic parkinsonism is slow and the rate of change between the two groups was comparable

  4. Positron Emission Tomography and Magnetic Resonance Imaging of the Brain in Fabry Disease

    DEFF Research Database (Denmark)

    Korsholm, Kirsten; Feldt-Rasmussen, Ulla; Granqvist, Henrik

    2015-01-01

    also inspected visually and severity of white matter lesions (WMLs) was graded using a visual rating scale. RESULTS: In 28 patients brain-FDG-PET was normal; in 23 of these 28 patients brain MRI was normal--of the remaining five patients in this group, four patients had WMLs and one patient never had...... risk of cerebrovascular disease at a young age in addition to heart and kidney failure. OBJECTIVE: The objective of this study was to assess brain function and structure in the Danish cohort of patients with Fabry disease in a prospective way using 18-fluoro-deoxyglucose (F-18 FDG) positron emission...... tomography (PET) and magnetic resonance imaging (MRI). PATIENTS: Forty patients with Fabry disease (14 males, 26 females, age at inclusion: 10-66 years, median: 39 years) underwent a brain F-18-FDG-PET-scan at inclusion, and 31 patients were followed with FDG-PET biannually for up to seven years. All...

  5. New tracers developed in positron emission tomography: a possible second breath in targeting tumour hypoxia?

    International Nuclear Information System (INIS)

    Baillet, G.; Groheux, D.; Barre, E.; Toubert, M.E.; Dechaud, C.; Teyton, P.; Moretti, J.L.; Le Beau de Hemricourt, E.

    2007-01-01

    There is an increasing interest for targeting of tumor hypoxia and our paper aimed to emphasize the main points of this topic. We review new insights at cellular level and focus on the leading part of hypoxia inducible factor one alpha and its connections with angio genesis. We shortly describe different methods to assess tissue hypoxia then zoom on to positron emission tomography and its acknowledged tracers 18 F-fluoro misonidazole and 18 F-fluoro-erythro-nitroimidazole. Recent studies concerning two new promising tracers Cu(II)-di-acetyl-bis(N(4)-methyl-thio-semicarbazone) and FAZA are reviewed, and the respective value of the tracers is discussed. (N.C.)

  6. Facile synthesis of ( sup 11 C)buprenorphine for positron emission tomographic studies of opioid receptors

    Energy Technology Data Exchange (ETDEWEB)

    Lever, J.R.; Dannals, R.F.; Wagner, H.N. Jr. (Johns Hopkins Univ., Baltimore, MD (USA). School of Hygiene and Public Health Johns Hopkins Univ., Baltimore, MD (USA). Dept. of Radiology); Mazza, S.M. (Johns Hopkins Univ., Baltimore, MD (USA). School of Hygiene and Public Health); Ravert, H.T.; Wilson, A.A. (Johns Hopkins Univ., Baltimore, MD (USA). Dept. of Radiology)

    1990-01-01

    We have developed a simple and rapid method for the production of buprenorphine (BPN), a potent opioid partial agonist, labelled with carbon-11 at the 6-methoxy position. The procedure uses a precursor synthesized in high yield (89%) from BPN in two steps and employs ({sup 11}C)iodomethane as the radiolabelling reagent. ({sup 11}C)BPN of 97% radiochemical purity can be prepared in high specific activity (41 GBq/{mu}mol; 1120 mCi/{mu}mol) in a radiochemical yield of 10% at end-of-synthesis (not decay corrected). The ({sup 11}C)BPN is available for use in studies of cerebral opioid receptors by positron emission tomography within 24 min from end-of-bombardment, including radiosynthesis, purification, formulation for i.v. injection and determination of specific activity. (author).

  7. The ECAT ART Scanner for Positron Emission Tomography. 1. Improvements in Performance Characteristics.

    Science.gov (United States)

    Townsend, David W.; Beyer, Thomas; Jerin, Jeff; Watson, Charles C.; Young, John; Nutt, Ronald

    1999-01-01

    The widespread use of positron emission tomography (PET) has been to some extent limited by the cost and complexity of PET instrumentation. Recognition of the wider applicability of clinical PET imaging is reflected in the ECAT ART design, a low cost PET scanner targeted for clinical applications, particularly in oncology. The ART comprises two asymmetrically opposed arrays of BGO block detectors. Each array consists of 88 (transaxial) by 24 (axial) crystals, and the arrays rotate continuously at 30 rpm to acquire a full 3D projection data set. Sensitivity and count rate limitations are key performance parameters for any imaging device. This paper reports on improved performance characteristics of the ART, achieved by operating the scanner with a decreased block integration time, reduced coincidence time window, and collimated singles transmission sources. Compared to the standard ART configuration, these modifications result in both improved count rate performance and higher quality transmission scans.

  8. Current applications and future developments of positron emission tomography in head and neck cancer

    International Nuclear Information System (INIS)

    Lonneux, M.

    2005-01-01

    Positron emission tomography (PET-scan) is a well-established imaging modality in oncology. Using FDG, PET has also a wide range of applications in head and neck tumors for diagnosis, staging, monitoring of response to therapy, and detection of relapse. After a short technical introduction, the current indications of PET-FDG in head and neck tumors are reviewed. Present and future developments of PET are twofold: the use of new tracers for protein synthesis, cellular proliferation or detection of hypoxia etc., and the introduction of metabolic imaging as a adjunct to CT and MRI to determine target-volumes in radiation treatment planning. However, it has to be emphasized that a thorough clinical validation of the methods used is mandatory before their implementation in routine practice. (author)

  9. Radiochemical syntheses further radiopharmaceuticals for positron emission tomography and new strategies for their production

    CERN Document Server

    Kilbourn, Michael R; Kilbourn, Michael R

    2015-01-01

    This book describes methods and procedures for preparing PET radiopharmaceuticals, and highlights new methods for conducting radiochemical reactions with carbon-11 (C11) and fluorine-18 (F18), which are two of the most commonly used radionuclides in positron emission tomography (PET) imaging.     Provides reliable methods for radiochemical syntheses and reactions, including all essential information to duplicate the procedure     Eliminates the time-consuming process of searching journal articles and extracting pertinent details from lengthy experimental sections or supporting information     Focuses on an emerging and important area for pharmaceutical and medical applications     Encompasses technical, regulatory, and application aspects     Includes solid-phase radiochemistry, transition-metal catalyzed radiochemistry, microfluidics, click chemistry, green radiochemistry and new strategies for radiopharmaceutical quality control.

  10. 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 ...

  11. Marked reduction of cerebral oxygen metabolism in patients with advanced cirrhosis; A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Kawatoko, Toshiharu; Murai, Koichiro; Ibayashi, Setsurou; Tsuji, Hiroshi; Nomiyama, Kensuke; Sadoshima, Seizo; Eujishima, Masatoshi; Kuwabara, Yasuo; Ichiya, Yuichi (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1992-01-01

    Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO{sub 2}), and oxygen extraction fraction (rOEF) were measured using positron emission tomography (PET) in four patients with cirrhosis (two males and two females, aged 57 to 69 years) in comparison with those in five age matched controls with previous transient global amnesia. PET studies were carried out when the patients were fully alert and oriented after the episodes of encephalopathy. In the patients, rCBF tended to be lower, while rCMRO{sub 2} was significantly lowered in almost all hemisphere cortices, more markedly in the frontal cortex. Our results suggest that the brain oxygen metabolism is diffusely impaired in patients with advanced cirrhosis, and the frontal cortex seems to be more susceptible to the systemic metabolic derangements induced by chronic liver disease. (author).

  12. Speech processing system demonstrated by positron emission tomography (PET). A review of the literature

    International Nuclear Information System (INIS)

    Hirano, Shigeru; Naito, Yasushi; Kojima, Hisayoshi

    1996-01-01

    We review the literature on speech processing in the central nervous system as demonstrated by positron emission tomography (PET). Activation study using PET has been proved to be a useful and non-invasive method of investigating the speech processing system in normal subjects. In speech recognition, the auditory association areas and lexico-semantic areas called Wernicke's area play important roles. Broca's area, motor areas, supplementary motor cortices and the prefrontal area have been proved to be related to speech output. Visual speech stimulation activates not only the visual association areas but also the temporal region and prefrontal area, especially in lexico-semantic processing. Higher level speech processing, such as conversation which includes auditory processing, vocalization and thinking, activates broad areas in both hemispheres. This paper also discusses problems to be resolved in the future. (author) 42 refs

  13. Role of 18F-fluorodeoxyglucose Positron Emission Tomography scan in differentiating enhancing brain tumors

    International Nuclear Information System (INIS)

    Das, Kajal; Mathuriya, Suresh N.; Mittal, Bhagwant R.; Vasistha, Rakesh K.; Singh, Paramjit

    2011-01-01

    To determine whether F-18-fluorodeoxyglucose positron emission tomography (F-18-FDG PET) can be used to differentiate among common enhancing brain tumors such as gliomas, metastatic brain tumors, and lymphoma. We evaluated 20 patients with an enhancing brain tumor on magnetic resonance imaging (MRI). FDG PET scan was done in all patients pre operatively. For PET image analysis, regions of interest were placed over the tumor (T), contralateral cortex (C), and white matter (WM). Average and maximum pixel values were determined at each site. On the basis of these measurements, average and maximum standard uptake values (SUV avg and SUV max ) were calculated, and comparisons among lesions were then made. FDG PET appears to provide additional information for differentiating common enhancing malignant brain tumors, namely lymphoma versus high grade glioma and metastatic tumor, particularly when differential diagnoses are difficult to narrow using MRI alone

  14. Prognostic Evaluation of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Endometrial Cancer

    DEFF Research Database (Denmark)

    Vilstrup, Mie Holm; Jochumsen, Kirsten M; Hess, Søren

    2017-01-01

    OBJECTIVE: This study aims to ascertain if semiquantitative measurements derived from F-fluorodeoxyglucose positron emission tomography/computed tomography can be used as prognostic markers in patients with newly diagnosed endometrial cancer. MATERIALS AND METHODS: Patients with endometrial cancer...... proportional regression models were used for prognostic evaluation. RESULTS: Eighty-three patients (median age, 69.9 y; range, 26.8-91.1) with primarily high-risk endometrial cancer or suspected high The International Federation of Gynecology and Obstetrics stage were included. Mean follow-up time was 3......-risk endometrial cancer. Thus, SUVmax and cTLG might help identify patients who could benefit from a more aggressive treatment strategy or closer surveillance....

  15. Diagnostic performance of fluorodeoxyglucose positron emission tomography/magnetic resonance imaging fusion images of gynecological malignant tumors. Comparison with positron emission tomography/computed tomography

    International Nuclear Information System (INIS)

    Nakajo, Kazuya; Tatsumi, Mitsuaki; Inoue, Atsuo

    2010-01-01

    We compared the diagnostic accuracy of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and PET/magnetic resonance imaging (MRI) fusion images for gynecological malignancies. A total of 31 patients with gynecological malignancies were enrolled. FDG-PET images were fused to CT, T1- and T2-weighted images (T1WI, T2WI). PET-MRI fusion was performed semiautomatically. We performed three types of evaluation to demonstrate the usefulness of PET/MRI fusion images in comparison with that of inline PET/CT as follows: depiction of the uterus and the ovarian lesions on CT or MRI mapping images (first evaluation); additional information for lesion localization with PET and mapping images (second evaluation); and the image quality of fusion on interpretation (third evaluation). For the first evaluation, the score for T2WI (4.68±0.65) was significantly higher than that for CT (3.54±1.02) or T1WI (3.71±0.97) (P<0.01). For the second evaluation, the scores for the localization of FDG accumulation showing that T2WI (2.74±0.57) provided significantly more additional information for the identification of anatomical sites of FDG accumulation than did CT (2.06±0.68) or T1WI (2.23±0.61) (P<0.01). For the third evaluation, the three-point rating scale for the patient group as a whole demonstrated that PET/T2WI (2.72±0.54) localized the lesion significantly more convincingly than PET/CT (2.23±0.50) or PET/T1WI (2.29±0.53) (P<0.01). PET/T2WI fusion images are superior for the detection and localization of gynecological malignancies. (author)

  16. Development of a dedicated positron emission tomography system for the detection and biopsy of breast cancer

    International Nuclear Information System (INIS)

    Dedicated positron emission mammography breast imaging systems have shown great promise for the detection of small, radiotracer-avid lesions. Our group (a collaboration consisting of West Virginia University, Jefferson Lab and the University of Washington) is extending this work by developing a positron emission mammography-tomography (PEM-PET) system for imaging and biopsy of breast lesions. The system will have four planar detector heads that will rotate about the breast to acquire multi-view data suitable for tomographic reconstruction. Each detector head will consist of a 96x72 array of 2x2x15 mm 3 LYSO detector elements (pitch=2.1 mm) mounted on a 3x4 array of 5x5 cm 2 flat panel position-sensitive photomultiplier tubes. PEM-PET is expected to have approximately two-millimeter resolution and possess the ability to guide the needle biopsy of suspicious lesions seen on the PET images. Initial tests of the scintillator arrays yielded excellent results. Pixel maps for all four scintillator arrays demonstrated that separation of the LYSO elements was very good; all of the LYSO array elements were observed, even in areas between individual PSPMTs. System energy resolution was measured to be 25% FWHM at 511 keV. Future work includes the use of field programmable gate arrays (FPGAs) to replace the current VME-based data acquisition system, a PSPMT gain normalization procedure to help improve response uniformity and energy resolution, and the addition of an x-ray source and detector to produce multi-modality PEM-PET-CT images of the breast

  17. Predicting Outcome in Patients with Rhabdomyosarcoma: Role of [18F]Fluorodeoxyglucose Positron Emission Tomography

    International Nuclear Information System (INIS)

    Casey, Dana L.; Wexler, Leonard H.; Fox, Josef J.; Dharmarajan, Kavita V.; Schoder, Heiko; Price, Alison N.; Wolden, Suzanne L.

    2014-01-01

    Purpose: To evaluate whether [ 18 F]fluorodeoxyglucose positron emission tomography (FDG-PET) response of the primary tumor after induction chemotherapy predicts outcomes in rhabdomyosarcoma (RMS). Methods and Materials: After excluding those with initial tumor resection, 107 patients who underwent FDG-PET after induction chemotherapy at Memorial Sloan Kettering Cancer Center from 2002 to 2013 were reviewed. Local control (LC), progression-free survival (PFS), and overall survival (OS) were calculated according to FDG-PET response and maximum standardized uptake value (SUV) at baseline (PET1/SUV1), after induction chemotherapy (PET2/SUV2), and after local therapy (PET3/SUV3). Receiver operator characteristic curves were used to determine the optimal cutoff for dichotomization of SUV1 and SUV2 values. Results: The SUV1 (<9.5 vs ≥9.5) was predictive of PFS (P=.02) and OS (P=.02), but not LC. After 12 weeks (median) of induction chemotherapy, 45 patients had negative PET2 scans and 62 had positive scans: 3-year PFS was 72% versus 44%, respectively (P=.01). The SUV2 (<1.5 vs ≥1.5) was similarly predictive of PFS (P=.005) and was associated with LC (P=.02) and OS (P=.03). A positive PET3 scan was predictive of worse PFS (P=.0009), LC (P=.05), and OS (P=.03). Conclusions: [ 18 F]fluorodeoxyglucose positron emission tomography is an early indicator of outcomes in patients with RMS. Future prospective trials may incorporate FDG-PET response data for risk-adapted therapy and early assessment of new treatment regimens

  18. Usefulness of Positron Emission Tomography in Patients with Syphilis: A Systematic Review of Observational Studies.

    Science.gov (United States)

    Chen, Jian-Hua; Zheng, Xin; Liu, Xiu-Qin

    2017-05-05

    Diagnosis of syphilis is difficult. Follow-up and therapy evaluation of syphilitic patients are poor. Little is known about positron emission tomography (PET) in syphilis. This review was to systematically review usefulness of PET for diagnosis, disease extent evaluation, follow-up, and treatment response assessment in patients with syphilis. We searched PubMed, EMBASE, SCOPUS, Cochrane Library, Web of Science, ClinicalTrials.gov, and three Chinese databases (SinoMed, Wanfang, and CNKI) for English and Chinese language articles from inception to September 2016. We also collected potentially relevant studies and reviews using a manual search. The search keywords included the combined text and MeSH terms "syphilis" and "positron emission tomography". We included studies that reporting syphilis with a PET scan before and/or after antibiotic treatment. The diagnosis of syphilis was based on serological criteria or dark field microscopy. Outcomes include pre- and post-treatment PET scan, pre- and post-treatment computed tomography, and pre- and post-treatment magnetic resonance imaging. We excluded the articles not published in English or Chinese or not involving humans. Of 258 identified articles, 34 observational studies were included. Thirty-three studies were single-patient case reports and one study was a small case series. All patients were adults. The mean age of patients was 48.3 ± 12.1 years. In primary syphilis, increased fluorodeoxyglucose (FDG) accumulation could be seen at the site of inoculation or in the regional lymph nodes. In secondary syphilis with lung, bone, gastrointestinal involvement, or generalized lymphadenopathy, increased FDG uptake was the most commonly detected changes. In tertiary syphilis, increased glucose metabolic activity, hypometabolic lesions, or normal glucose uptake might be seen on PET. There were five types of PET scans in neurosyphilis. A repeated PET scan after treatment revealed apparent or complete resolution of the

  19. [18F]AV-1451 tau positron emission tomography in progressive supranuclear palsy.

    Science.gov (United States)

    Whitwell, Jennifer L; Lowe, Val J; Tosakulwong, Nirubol; Weigand, Stephen D; Senjem, Matthew L; Schwarz, Christopher G; Spychalla, Anthony J; Petersen, Ronald C; Jack, Clifford R; Josephs, Keith A

    2017-01-01

    The [ 18 F]AV-1451 positron emission tomography ligand allows the in vivo assessment of tau proteins in the brain. It shows strong binding in Alzheimer's dementia, but little is known about how it performs in progressive supranuclear palsy, a primary 4R tauopathy. The objectives of this study were to determine whether [ 18 F]AV-1451 uptake can be observed in progressive supranuclear palsy and to characterize the regional distribution when compared with controls and Alzheimer's dementia. [ 18 F]AV-1451 positron emission tomography was performed in 10 patients with probable progressive supranuclear palsy. These patients were age- and gender-matched to 50 controls and 10 Alzheimer's dementia patients who had undergone identical [ 18 F]AV-1451 imaging. Regional comparisons of [ 18 F]AV-1451 uptake were performed across the whole brain using region-of-interest and voxel-level analyses, and correlations between regional [ 18 F]AV-1451 and the progressive supranuclear palsy rating scale were assessed. An elevated [ 18 F]AV-1451 signal was observed in progressive supranuclear palsy when compared with controls in the pallidum, midbrain, dentate nucleus of the cerebellum, thalamus, caudate nucleus, and frontal regions. Signal in the cerebellar dentate and pallidum were also greater in progressive supranuclear palsy when compared with Alzheimer's dementia. Conversely, the [ 18 F]AV-1451 signal across the cortex was higher in Alzheimer's dementia when compared with progressive supranuclear palsy. The [ 18 F]AV-1451 signal in a number of regions correlated with the progressive supranuclear palsy rating scale. Progressive supranuclear palsy is associated with an elevated [ 18 F]AV-1451 signal in a characteristic and distinct regional pattern that correlates with disease severity and differs from the patterns observed in Alzheimer's dementia. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

  20. Measurement of lower limb blood flow in patients with neurogenic claudication using positron emission tomography.

    Science.gov (United States)

    Keenan, G F; Ashcroft, G P; Roditi, G H; Hutchison, J D; Evans, N T; Mikecz, P; Chaloner, F; Dodd, M; Leonard, C; Porter, R W

    1995-02-15

    Ten subjects (seven with neurogenic claudication and three control subjects) underwent examination of lower limb muscle blood flow before and after exercise using positron emission tomography. To investigate the hypothesis that lower limb muscle ischemia was the origin of symptoms in neurogenic claudication. Patients with neurogenic claudication secondary to spinal stenosis experience lower limb discomfort after exercise similar to that of ischemic claudication. However, they do not have clinical evidence of peripheral vascular disease. The authors postulated that the lower limb discomfort in patients with neurogenic claudication may arise from muscle ischemia due to inadequate dilatation of arterioles in response to exercise, this itself arising secondary to sympathetic dysfunction due to spinal stenosis. Using O15-labeled water and positron emission tomography measured thigh and leg muscle blood flow response to exercise bilaterally in seven patients with unilateral neurogenic claudication and three control subjects were measured. The average values obtained for mid-thigh and mid-calf muscle perfusion at rest were 2.57 ml/min/100 g tissue (2.23-3.90) and 2.39 ml/min/100 g tissue (2.03-3.46), respectively. The average values obtained from mid-thigh and mid-calf perfusion after exercise were 4.41 ml/min/100 g tissue (2.8-6.0) and 4.87 ml/min/100 g (2.2-11.7). We found no difference in muscle perfusion between symptomatic and asymptomatic limbs in this group of patients. These studies suggest that muscle ischemia is not the origin of symptoms in most patients with neurogenic claudication.

  1. Development of a dedicated positron emission tomography system for the detection and biopsy of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Raylman, Raymond R; Majewski, Stan; Kross, Brian; Popov, Vladimir; Proffitt, James; Smith, Mark F; Weisenberger, Andrew G; Wojcik, Randolph

    2006-12-01

    Dedicated positron emission mammography breast imaging systems have shown great promise for the detection of small, radiotracer-avid lesions. Our group (a collaboration consisting of West Virginia University, Jefferson Lab and the University of Washington) is extending this work by developing a positron emission mammography-tomography (PEM-PET) system for imaging and biopsy of breast lesions. The system will have four planar detector heads that will rotate about the breast to acquire multi-view data suitable for tomographic reconstruction. Each detector head will consist of a 96x72 array of 2x2x15 mm{sup 3} LYSO detector elements (pitch=2.1 mm) mounted on a 3x4 array of 5x5 cm{sup 2} flat panel position-sensitive photomultiplier tubes. PEM-PET is expected to have approximately two-millimeter resolution and possess the ability to guide the needle biopsy of suspicious lesions seen on the PET images. Initial tests of the scintillator arrays yielded excellent results. Pixel maps for all four scintillator arrays demonstrated that separation of the LYSO elements was very good; all of the LYSO array elements were observed, even in areas between individual PSPMTs. System energy resolution was measured to be 25% FWHM at 511 keV. Future work includes the use of field programmable gate arrays (FPGAs) to replace the current VME-based data acquisition system, a PSPMT gain normalization procedure to help improve response uniformity and energy resolution, and the addition of an x-ray source and detector to produce multi-modality PEM-PET-CT images of the breast.

  2. Development of a dedicated positron emission tomography system for the detection and biopsy of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Raylman, Raymond R. [Center for Advanced Imaging, Department of Radiology, West Virginia University, Morgantown, WV (United States)]. E-mail: rraylman@wvu.edu; Majewski, Stan [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kross, Brian [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Popov, Vladimir [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Proffitt, James [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Smith, Mark F. [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Weisenberger, Andrew G. [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Wojcik, Randy [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2006-12-20

    Dedicated positron emission mammography breast imaging systems have shown great promise for the detection of small, radiotracer-avid lesions. Our group (a collaboration consisting of West Virginia University, Jefferson Lab and the University of Washington) is extending this work by developing a positron emission mammography-tomography (PEM-PET) system for imaging and biopsy of breast lesions. The system will have four planar detector heads that will rotate about the breast to acquire multi-view data suitable for tomographic reconstruction. Each detector head will consist of a 96x72 array of 2x2x15 mm{sup 3} LYSO detector elements (pitch=2.1 mm) mounted on a 3x4 array of 5x5 cm{sup 2} flat panel position-sensitive photomultiplier tubes. PEM-PET is expected to have approximately two-millimeter resolution and possess the ability to guide the needle biopsy of suspicious lesions seen on the PET images. Initial tests of the scintillator arrays yielded excellent results. Pixel maps for all four scintillator arrays demonstrated that separation of the LYSO elements was very good; all of the LYSO array elements were observed, even in areas between individual PSPMTs. System energy resolution was measured to be 25% FWHM at 511 keV. Future work includes the use of field programmable gate arrays (FPGAs) to replace the current VME-based data acquisition system, a PSPMT gain normalization procedure to help improve response uniformity and energy resolution, and the addition of an x-ray source and detector to produce multi-modality PEM-PET-CT images of the breast.

  3. Imaging sensitivity of dedicated positron emission mammography in relation to tumor size.

    Science.gov (United States)

    Eo, Jae Seon; Chun, In Kook; Paeng, Jin Chul; Kang, Keon Wook; Lee, Sang Mi; Han, Wonshik; Noh, Dong-Young; Chung, June-Key; Lee, Dong Soo

    2012-02-01

    Positron emission mammography (PEM) has been reported to have higher sensitivity than whole-body positron emission tomography (PET)due to higher spatial resolution. However, no direct evidence exists regarding the imaging sensitivity of PEM related to lesion size. In the present study, imaging sensitivity of PEM was investigated in relation to pathologically confirmed tumor size. A total of 113 breast lesions from 101 patients were included in the analysis. The patients underwent (18)F-fluorodeoxyglucose (FDG) PEM and whole-body PET/computed tomography (CT) before surgical resection, and images were analyzed visually and quantitatively using the tumor-to-normal-tissue uptake ratio (TNR). Tumors were classified into four groups based on size using pathologic results, and sensitivities of PEM and PET/CT were compared in the overall subjects and in each size group. In visual analysis, PEM showed significantly higher imaging sensitivity than PET/CT (95% vs. 87%; P = 0.004), which was more definite in the small-tumor groups. In quantitative analysis, the TNR of PEM was significantly higher than that of PET/CT in the small-tumor groups, whereas no difference was found in the overall group. With a cutoff TNR of 2.5, PEM showed significantly higher sensitivity than PET/CT in the overall and small-tumor groups. In conclusion, PEM had higher imaging sensitivity than PET/CT, particularly in small tumors. The results suggest that PEM may be used for diagnosis and characterization of small lesions as a supplementary imaging modality for PET/CT. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. A preliminary report of breast cancer screening by positron emission mammography.

    Science.gov (United States)

    Yamamoto, Yayoi; Tasaki, Youichiro; Kuwada, Yukiko; Ozawa, Yukihiko; Inoue, Tomio

    2016-02-01

    Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) and PET/computed tomography (PET/CT) have had a considerable impact on the detection of various malignancies. PET and PET/CT are minimally invasive methods that can provide whole-body imaging at one time. Therefore, an FDG-PET cancer screening program has been widely used in Japan. However, the breast cancer detection rate of FDG-PET cancer screening is relatively low. Therefore, FDG-PET screening is not recommended for breast cancer screening. Positron emission mammography (PEM) is a high-resolution molecular breast imaging technology. PEM can detect small breast cancers that cannot be detected on PET or PET/CT images due to limited spatial resolution. We have performed opportunistic breast cancer screening using PEM since 2011. To the best of our knowledge, this is the first report regarding PEM breast cancer screening. This study enrolled 265 women. PEM images were analyzed by agreement of 2 experienced nuclear medicine physicians. The readers were given information from medical interview sheet. US findings were interpreted holistically. The number of participants, patient recall rate, further examination rate, and cancer detection rate by year were calculated. The overall recall rate was 8.3%; the work-up examination rate was 77.3%, and cancer detection rate was 2.3%. The positive predictive value of PEM was 27.3%. Six cancers were found by PEM screening. Five were invasive cancers and one was ductal carcinoma in situ. Histological tumor sizes were reported in three cases: 0.7, 1.2, and 2 cm. PEM screening appears to have potential for breast cancer screening.

  5. A Lower-Cost High-Resolution LYSO Detector Development for Positron Emission Mammography (PEM).

    Science.gov (United States)

    Ramirez, Rocio A; Zhang, Yuxuan; Liu, Shitao; Li, Hongdi; Baghaei, Hossain; An, Shaohui; Wang, Chao; Jan, Meei-Ling; Wong, Wai-Hoi

    2009-10-01

    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 portion of the PMTs for a low-cost, high-resolution, and high-sensitivity positron emission mammography (PEM) camera. We modified the PQS design by using elongated blocks at panel edges and square blocks in the inner area. For elongated blocks, symmetric and asymmetrical reflector patterns were developed and PQS and PMT-half-sharing (PHS) arrangements were implemented in order to obtain a suitable decoding. The packing fraction was 96.3% for asymmetric block and 95.5% for symmetric block. Both of the blocks have excellent decoding capability with all crystals clearly identified, 156 for asymmetric and 144 for symmetric and peak-to-valley ratio of 3.0 and 2.3 respectively. The average energy resolution was 14.2% for the asymmetric block and 13.1% for the symmetric block. Using a modified PQS geometry and asymmetric block design, we reduced the unused PMT region at detector panel edges, thereby increased the field-of-view and the overall detection sensitivity and minimized the undetected breast region near the chest wall. This detector design and using regular round PMT allowed building a lower-cost, high-resolution and high-sensitivity PEM camera.

  6. Cerebral blood flow measured by positron emission tomography during normothermic cardiopulmonary bypass: an experimental porcine study.

    Science.gov (United States)

    Thomassen, Sisse Anette; Kjærgaard, Benedict; Alstrup, Aage Kristian Olsen; Munk, Ole Lajord; Frøkiær, Jørgen; Larsson, Anders; Rasmussen, Bodil Steen

    2018-01-01

    Mean arterial blood pressure (MAP) and/or pump flow during normothermic cardiopulmonary bypass (CPB) are the most important factors of cerebral perfusion. The aim of this study was to explore the influence of CPB blood flow on cerebral blood flow (CBF) measured by dynamic positron emission tomography (PET) using 15 O-labelled water with no pharmacological interventions to maintain the MAP. Eight pigs (69-71 kg) were connected to normothermic CPB. After 60 minutes (min) with a CPB pump flow of 60 mL/kg/min, the pigs were changed to either 35 mL/kg/min or 47.5 mL/kg/min for 60 min and, thereafter, all the pigs returned to 60 mL/kg/min for another 60 min. The MAP was measured continuously and the CBF was measured by positron emission tomography (PET) during spontaneous circulation and at each CPB pump flow after 30 min of steady state. Two pigs were excluded due to complications. CBF increased from spontaneous circulation to a CPB pump flow of 60 mL/kg/min. A reduction in CPB pump flow to 47.5 mL/kg/min (n=3) resulted in only minor changes in CBF while a reduction to 35 mL/kg/min (n=3) caused a pronounced change (correlation coefficient (R 2 ) 0.56). A return of CPB pump flow to 60 mL/kg/min was followed by an increase in CBF, except in the one pig with the lowest CBF during low flow (R 2 =0.44). CBF and MAP were not correlated (R 2 =0.20). In this experimental porcine study, a relationship was observed between pump flow and CBF under normothermic low-flow CPB. The effect of low pump flow on MAP showed substantial variations, with no correlation between CBF and MAP.

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

    Directory of Open Access Journals (Sweden)

    Mohsen Mashayekhi

    2015-05-01

    Application of a magnetic field perpendicular to the positron diffusion plane prevented the scattering of positrons, and consequently, improved the intrinsic spatial resolution of PET imaging, caused by positron range effects.

  8. Development of skin surface radiation detector system to monitor radioactivity in arterial blood along with positron emission tomography

    International Nuclear Information System (INIS)

    Watabe, Hiroshi; Miyake, Masayasu; Narita, Yuichirou; Nakamura, Takashi; Itoh, Masatoshi

    1995-01-01

    A noninvasive blood radioactivity monitor system for Positron Emission Tomography (PET) study has been developed. This system has dual plastic scintillators to detect positrons from the wrist artery. One is for monitoring the blood radioactivity in artery and tissue, and another is for monitoring only in tissue, in order to subtract background radiation from tissue. The authors carried out phantom experiments for evaluating basic characteristics of this monitor system. Clinical experiments using 15 O-labeled water were also done to compare this system with a conventional invasive monitor

  9. Real-time tumor tracking using implanted positron emission markers: Concept and simulation study

    International Nuclear Information System (INIS)

    Xu Tong; Wong, Jerry T.; Shikhaliev, Polad M.; Ducote, Justin L.; Al-Ghazi, Muthana S.; Molloi, Sabee

    2006-01-01

    The delivery accuracy of radiation therapy for pulmonary and abdominal tumors suffers from tumor motion due to respiration. Respiratory gating should be applied to avoid the use of a large target volume margin that results in a substantial dose to the surrounding normal tissue. Precise respiratory gating requires the exact spatial position of the tumor to be determined in real time during treatment. Usually, fiducial markers are implanted inside or next to the tumor to provide both accurate patient setup and real-time tumor tracking. However, current tumor tracking systems require either substantial x-ray exposure to the patient or large fiducial markers that limit the value of their application for pulmonary tumors. We propose a real-time tumor tracking system using implanted positron emission markers (PeTrack). Each marker will be labeled with low activity positron emitting isotopes, such as 124 I, 74 As, or 84 Rb. These isotopes have half-lives comparable to the duration of radiation therapy (from a few days to a few weeks). The size of the proposed PeTrack marker will be 0.5-0.8 mm, which is approximately one-half the size of markers currently employed in other techniques. By detecting annihilation gammas using position-sensitive detectors, multiple positron emission markers can be tracked in real time. A multimarker localization algorithm was developed using an Expectation-Maximization clustering technique. A Monte Carlo simulation model was developed for the PeTrack system. Patient dose, detector sensitivity, and scatter fraction were evaluated. Depending on the isotope, the lifetime dose from a 3.7 MBq PeTrack marker was determined to be 0.7-5.0 Gy at 10 mm from the marker. At the center of the field of view (FOV), the sensitivity of the PeTrack system was 240-320 counts/s per 1 MBq marker activity within a 30 cm thick patient. The sensitivity was reduced by 45% when the marker was near the edge of the FOV. The scatter fraction ranged from 12% ( 124 I, 74 As

  10. Preliminary results for positron emission mammography: real-time functional breast imaging in a conventional mammography gantry.

    Science.gov (United States)

    Weinberg, I; Majewski, S; Weisenberger, A; Markowitz, A; Aloj, L; Majewski, L; Danforth, D; Mulshine, J; Cowan, K; Zujewski, J; Chow, C; Jones, E; Chang, V; Berg, W; Frank, J

    1996-07-01

    In order to optimally integrate radiotracer breast imaging within the breast clinic, anatomy and pathology should be easily correlated with functional nuclear medicine breast images. As a first step in the development of a hybrid functional/anatomic breast imaging platform with biopsy capability, a conventional X-ray mammography gantry was modified to image the compressed breast with positron emitters. Phantom studies with the positron emission mammography (PEM) device showed that a 1-cc hot spot could be detected within 5 min. A preliminary clinical trial demonstrated in vivo visualization of primary breast cancer within 4 min. For sites where positron-emitting radionuclides are available, PEM promises to achieve low-cost directed functional examination of breast abnormalities, with the potential for achieving X-ray correlation and image-guided biopsy.

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

    International Nuclear Information System (INIS)

    Parodi, Katia

    2015-01-01

    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

  12. Optimised motion tracking for positron emission tomography studies of brain function in awake rats.

    Directory of Open Access Journals (Sweden)

    Andre Z Kyme

    Full Text Available Positron emission tomography (PET is a non-invasive molecular imaging technique using positron-emitting radioisotopes to study functional processes within the body. High resolution PET scanners designed for imaging rodents and non-human primates are now commonplace in preclinical research. Brain imaging in this context, with motion compensation, can potentially enhance the usefulness of PET by avoiding confounds due to anaesthetic drugs and enabling freely moving animals to be imaged during normal and evoked behaviours. Due to the frequent and rapid motion exhibited by alert, awake animals, optimal motion correction requires frequently sampled pose information and precise synchronisation of these data with events in the PET coincidence data stream. Motion measurements should also be as accurate as possible to avoid degrading the excellent spatial resolution provided by state-of-the-art scanners. Here we describe and validate methods for optimised motion tracking suited to the correction of motion in awake rats. A hardware based synchronisation approach is used to achieve temporal alignment of tracker and scanner data to within 10 ms. We explored the impact of motion tracker synchronisation error, pose sampling rate, rate of motion, and marker size on motion correction accuracy. With accurate synchronisation (20 Hz, and a small head marker suitable for awake animal studies, excellent motion correction results were obtained in phantom studies with a variety of continuous motion patterns, including realistic rat motion (<5% bias in mean concentration. Feasibility of the approach was also demonstrated in an awake rat study. We conclude that motion tracking parameters needed for effective motion correction in preclinical brain imaging of awake rats are achievable in the laboratory setting. This could broaden the scope of animal experiments currently possible with PET.

  13. Determination of spatial resolution of positron emission tomograph of clear PET-XPAD3/CT system

    Energy Technology Data Exchange (ETDEWEB)

    Olaya D, H.; Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, 150003 Tunja, Boyaca (Colombia); Morel, C. [Centre de Physique des Particules de Marseille, ImXgam Group, 13009 Marseille (France); Castro, H. F. [Universidad Nacional de Colombia, Physics Department, Carrera 45 No. 26-85, Bogota (Colombia)

    2016-10-15

    Based on the National Electrical Manufacturers Association (Nema), using the Amine software to construction of sinograms and using a radioactive source {sup 22}Na that emitting positrons were made calculations for determine spatial resolution of ring array system of phoswich detectors of positron emission tomograph included in the Clear PET-XPAD3/CT prototype for small animals made in the laboratories of CCPM and whose project is led by the research group ImXgam. The radioactive source {sup 22}Na approximately 9 MBq of activity, with spherical shape and diameter of 0.57 mm immersed in a plexiglas disc was located at the geometric center of tomographic system with a Field of View (Fov) of 35 mm in the axial and transverse directions. Displacements of radioactive source were performed on the three cartesian axes and was rebuilt a sinogram for each axis. The shape of sinogram allow describe the correct position and the maximum efficiency of each detector. Subsequently, was carried out a scanning in each one of three spatial axes taking an enough distance covering the dimensions of radioactive source, were recorded data for each one of phoswich detector crystals which are aligned in the axis of movement. The process was repeated for other axes and then was offsetting the radioactive source with respect to the Fov and were calculated FWHM (Full Width at Half Maximum) and FWTM (Full Width at Tenth Maximum) values and performing statistics of these values with parabolic fitting, the latter setting allows to obtain parameters of spatial resolution of system. (Author)

  14. Determination of spatial resolution of positron emission tomograph of clear PET-XPAD3/CT system

    International Nuclear Information System (INIS)

    Olaya D, H.; Martinez O, S. A.; Morel, C.; Castro, H. F.

    2016-10-01

    Based on the National Electrical Manufacturers Association (Nema), using the Amine software to construction of sinograms and using a radioactive source 22 Na that emitting positrons were made calculations for determine spatial resolution of ring array system of phoswich detectors of positron emission tomograph included in the Clear PET-XPAD3/CT prototype for small animals made in the laboratories of CCPM and whose project is led by the research group ImXgam. The radioactive source 22 Na approximately 9 MBq of activity, with spherical shape and diameter of 0.57 mm immersed in a plexiglas disc was located at the geometric center of tomographic system with a Field of View (Fov) of 35 mm in the axial and transverse directions. Displacements of radioactive source were performed on the three cartesian axes and was rebuilt a sinogram for each axis. The shape of sinogram allow describe the correct position and the maximum efficiency of each detector. Subsequently, was carried out a scanning in each one of three spatial axes taking an enough distance covering the dimensions of radioactive source, were recorded data for each one of phoswich detector crystals which are aligned in the axis of movement. The process was repeated for other axes and then was offsetting the radioactive source with respect to the Fov and were calculated FWHM (Full Width at Half Maximum) and FWTM (Full Width at Tenth Maximum) values and performing statistics of these values with parabolic fitting, the latter setting allows to obtain parameters of spatial resolution of system. (Author)

  15. 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

  16. Efficacy of 3D-positron emission tomography/computed tomography for upper abdomen.

    Science.gov (United States)

    Murakami, Koji; Nakahara, Tadaki

    2014-04-01

    Recent advancement in computed tomography (CT) enables us to obtain high spatial resolution image and made it possible to construct extensive high-definition three-dimensional (3D) images. But a lack of contrast resolution in CT alone is still remained problem. Meanwhile, as fluorodeoxyglucose-positron emission tomography (PET) can visualize tumors in high contrast, we can create 3D images fusing the accumulation in tumors on PET/CT images. Such images can play the role of a "map of body" which makes it easy to understand the anatomical information before surgery. We also try to evaluate segmental liver function by using PET/CT fusion images. By using (11) C-methionine PET/contrast-enhanced CT, superior image quality compared to single photon emission computed tomography/CT can be obtained. CT, especially with contrast enhancement for obtaining anatomical imaging information plus PET for obtaining functional imaging information is a highly compatible combination, and adding these two types information will further increase clinical usefulness. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  17. Towards a practical implementation of the MLE algorithm for positron emission tomography

    International Nuclear Information System (INIS)

    Llacer, J.; Andreae, S.; Veklerov, E.; Hoffman, E.J.

    1986-01-01

    Recognizing that the quality of images obtained by application of the Maximum Likelihood Estimator (MLE) to Positron Emission Tomography (PET) and Single Photon Emission Tomography (SPECT) appears to be substantially better than those obtained by conventional methods, the authors have started to develop methods that will facilitate the necessary research for a good evaluation of the algorithm and may lead to its practical application for research and routine tomography. They have found that the non-linear MLE algorithm can be used with pixel sizes which are smaller than the sampling distance, without interpolation, obtaining excellent resolution and no noticeable increase in noise. They have studied the role of symmetry in reducing the amount of matrix element storage requirements for full size applications of the algorithm and have used that concept to carry out two reconstructions of the Derenzo phantom with data from the ECAT-III instrument. The results show excellent signal-to-noise (S/N) ratio, particularly for data with low total counts, excellent sharpness, but low contrast at high frequencies when using the Shepp-Vardi model for probability matrices

  18. Positron emission tomography in amyotrophic lateral sclerosis: Towards targeting of molecular pathological hallmarks

    Energy Technology Data Exchange (ETDEWEB)

    Willekens, Stefanie M.A.; Weehaeghe, Donatienne van [University Hospitals Leuven and KU Leuven, Division of Nuclear Medicine, Department of Imaging and Pathology, Leuven (Belgium); Damme, Philip van [University Hospitals Leuven, Department of Neurology, Leuven (Belgium); KU Leuven, Department of Neurosciences, Experimental Neurology, Leuven (Belgium); Leuven Research Institute for Neuroscience and Disease (LIND), Leuven (Belgium); VIB, Vesalius Research Center, Laboratory of Neurobiology, Leuven (Belgium); Laere, Koen van [University Hospitals Leuven and KU Leuven, Division of Nuclear Medicine, Department of Imaging and Pathology, Leuven (Belgium); Leuven Research Institute for Neuroscience and Disease (LIND), Leuven (Belgium)

    2017-03-15

    During the past decades, extensive efforts have been made to expand the knowledge of amyotrophic lateral sclerosis (ALS). However, clinical translation of this research, in terms of earlier diagnosis and improved therapy, remains challenging. Since more than 30% of motor neurons are lost when symptoms become clinically apparent, techniques allowing non-invasive, in vivo detection of motor neuron degeneration are needed in the early, pre-symptomatic disease stage. Furthermore, it has become apparent that non-motor signs play an important role in the disease and there is an overlap with cognitive disorders, such as frontotemporal dementia (FTD). Radionuclide imaging, such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT), form an attractive approach to quantitatively monitor the ongoing neurodegenerative processes. Although [{sup 18}F]-FDG has been recently proposed as a potential biomarker for ALS, active targeting of the underlying pathologic molecular processes is likely to unravel further valuable disease information and may help to decipher the pathogenesis of ALS. In this review, we provide an overview of radiotracers that have already been applied in ALS and discuss possible novel targets for in vivo imaging of various pathogenic processes underlying ALS onset and progression. (orig.)

  19. Long-term cigarette smoking is associated with increased myocardial perfusion heterogeneity assessed by positron emission tomography

    International Nuclear Information System (INIS)

    Meeder, J.G.; Blanksma, P.K.; Wall, E.E. van der; Anthonio, R.L.; Willemsen, A.T.M.; Pruim, J.; Vaalburg, W.; Lie, K.I.

    1996-01-01

    The pathophysiology of smoking-related coronary events in patients with normal coronary arteries is incompletely understood. This study was conducted to explore, in subjects without symptoms of cardiovascular disease, the long-term effects of smoking on regional coronary artery vasoactivity, especially during sympathetic stimulation. In ten smoking and ten non-smoking sex- and age-matched healthy volunteers, segmental myocardial perfusion was studied using dynamic parametric nitrogen-13 ammonia positron emission tomography at rest and during sympathetic stimulation evoked by the cold pressor stimulation. Smokers demonstrated a higher myocardial perfusion at rest (116±17 ml/min/100 g vs 96±20 ml/min/100 g, P <0.01) and an impaired myocardial perfusion increase during cold pressor stimulation (1.02±0.15 vs 1.18±0.17, P <0.05). The heterogeneity of perfusion, expressed as coefficient of variation, was significantly different between the smoking and the non-smoking group. The coefficient of variation of segmental myocardial perfusion was higher in smokers at rest (17.5%±4.2% vs 13.5%±1.9%, P <0.05) and during cold pressor stimulation (17.0%±3.2% vs 13.9%±1.8%, P <0.05). We conclude that the long-term effects of smoking in healthy volunteers are associated with (1) increased myocardial perfusion at rest, (2) impaired myocardial perfusion response to cold pressor stimulation, and (3) increased myocardial perfusion heterogeneity both at rest and during cold pressor stimulation. These results may suggest that in healthy subjects the long-term effect of smoking is related to abnormal coronary artery vasoactivity, presumably induced by an interplay of regional endothelial dysfunction and autonomic dysregulation. (orig.). With 1 fig., 1 tab

  20. Positron emission tomography/magnetic resonance hybrid scanner imaging of cerebral blood flow using 15O-water positron emission tomography and arterial spin labeling magnetic resonance imaging in newborn piglets

    DEFF Research Database (Denmark)

    Andersen, Julie B; Henning, William S; Lindberg, Ulrich

    2015-01-01

    arterial spin labeling (ASL) magnetic resonance imaging (MR) on a hybrid PET/MR in seven newborn piglets. Positron emission tomography was performed with IV injections of 20 MBq and 100 MBq (15)O-water to confirm CBF reliability at low activity. Cerebral blood flow was quantified using a one......Abnormality in cerebral blood flow (CBF) distribution can lead to hypoxic-ischemic cerebral damage in newborn infants. The aim of the study was to investigate minimally invasive approaches to measure CBF by comparing simultaneous (15)O-water positron emission tomography (PET) and single TI pulsed......, PET-IDIF overestimated CBF. Injected activity of 20 MBq (15)O-water had acceptable concordance with 100 MBq, without compromising image quality. Single TI ASL was questionable for regional CBF measurements. Global ASL CBF and PET CBF were congruent during baseline but not during hyperperfusion....

  1. Development of a positron emission mammography scanner for breast cancer detection

    International Nuclear Information System (INIS)

    Belcari, Nicola

    2004-01-01

    Positron Emission Mammography (PEM) is a relatively new nuclear medicine imaging technique for the detection and staging of breast cancer. PEM tries to overcome the limitations of existing whole body clinical PET scanners by means of a breast-dedicated design. We have designed a novel PEM scanner prototype, called YAP-PEM, based on a pair of opposing detector heads made up of a 6 cmx6 cm YAP:Ce scintillation matrix and position sensitive photo-detectors. This thesis work is dedicated to the detector development for the construction of the PEM scanner. The utilization of three different types of PSPMT have been evaluated: the R8520-00-C12, the well known R2486 and a very early version of the new H8500 'Flat Panel' PSPMT, all from Hamamatsu. These tubes have been fully characterized in terms of their imaging performance in the identification of small scintillation pixels. The H8500 confirmed the good expected performance and represents a noticeable advance in position sensitive photo-detection, in particular for its shape and size, that allows it to be tiled over large areas, as demanded by current and future application. The adopted final solution is based on an array of position sensitive PMTs, model R8520-00-C12, because of the size of the used YAP:Ce matrix that better fits with this solution. A complete signal processing and acquisition platform has been also developed for the utilization of an array of nine of these PS-PMTs. The first detector head composed of the YAP:Ce matrix and nine R8520 has been assembled, optimized and characterized. In the thesis the calibration procedures and evaluation results for the chosen detector solution for the PEM system are described. The work is completed by a full Monte Carlo simulation. Various parameters have been considered here; in particular the acquisition geometry and the tumor size. The Monte Carlo simulation on YAP-PEM indicates that our system could be able to detect very small tumors, down to 5 mm in diameter for

  2. High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ronzhin, A.; Los, S.; Martens, M.; Ramberg, E.; /Fermilab; Kim, H.; Chen, C.; Kao, C.; /Chicago U.; Niessen, K.; /SUNY, Buffalo; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez; Mazzillo, M.; Carbone, B.; /SGS Thomson, Catania

    2011-02-01

    We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomography (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile

  3. Second-Generation Triple Reporter for Bioluminescence, Micro–Positron Emission Tomography, and Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Aparna H. Kesarwala

    2006-10-01

    Full Text Available Bioluminescence, positron emission tomography (PET, and fluorescence modalities are currently available for noninvasive imaging in vivo, each with its own merits. To exploit the combined strengths of each and facilitate multimodality imaging, we engineered a dual-reporter construct in which firefly luciferase (FLuc and a 12–amino acid nonstructural linker were fused in frame to the N-terminus of a mutant herpes simplex virus thymidine kinase (mNLS-SR39TK kinetically enhanced for positron emission tomography (PET. Furthermore, a triple-reporter construct was developed in which monster green fluorescent protein (MGFP, a recently available enhanced fluorescent protein, was introduced into the fusion vector downstream of an internal ribosome entry site (IRES to allow analysis by fluorescence microscopy or flow cytometry without compromising the specific activities of the upstream fusion components. FLuc bioluminescence was measured with a cooled charge-coupled device camera and mNLS-SR39TK activity by 9-[4-[18F]fluoro-3-(hydroxymethyl butyl guanine (18F-FHBG microPET or 3H-penciclovir net accumulation. Importantly, HeLa cells transiently transfected with the FLuc-mNLS-SR39TK-IRES-MGFP triple reporter retained the same specific activities of the FLuc-mNLS-SR39TK heteroenzyme and the individual unfused enzymes with no change in protein half-lives. The presence of the IRES-MGFP modestly decreased upstream heteroprotein expression. In living mice, somatic gene transfer of a ubiquitin promoter-driven FLuc-mNLS-SR39TK-IRES-MGFP plasmid showed a > 1,000-fold increase in liver photon flux and a > 2-fold increase in liver retention of 18F-FHBG by microPET compared with mice treated with control plasmid. Multifocal hepatocellular fluorescence was readily observed by standard confocal microscopy. This second-generation triple reporter incorporating enhanced components enables bioluminescence, PET, and fluorescence imaging of cells and living animals.

  4. Modeling clustered activity increase in amyloid-beta positron emission tomographic images with statistical descriptors

    Directory of Open Access Journals (Sweden)

    Shokouhi S

    2015-04-01

    Full Text Available Sepideh Shokouhi,1 Baxter P Rogers,1 Hakmook Kang,2 Zhaohua Ding,1 Daniel O Claassen,3 John W Mckay,1 William R Riddle1On behalf of the Alzheimer’s Disease Neuroimaging Initiative1Department of Radiology and Radiological Sciences, Vanderbilt University Institute of Imaging Science, 2Department of Biostatistics, 3Department of Neurology, Vanderbilt University, Nashville, TN, USABackground: Amyloid-beta (Aβ imaging with positron emission tomography (PET holds promise for detecting the presence of Aβ plaques in the cortical gray matter. Many image analyses focus on regional average measurements of tracer activity distribution; however, considerable additional information is available in the images. Metrics that describe the statistical properties of images, such as the two-point correlation function (S2, have found wide applications in astronomy and materials science. S2 provides a detailed characterization of spatial patterns in images typically referred to as clustering or flocculence. The objective of this study was to translate the two-point correlation method into Aβ-PET of the human brain using 11C-Pittsburgh compound B (11C-PiB to characterize longitudinal changes in the tracer distribution that may reflect changes in Aβ plaque accumulation.Methods: We modified the conventional S2 metric, which is primarily used for binary images and formulated a weighted two-point correlation function (wS2 to describe nonbinary, real-valued PET images with a single statistical function. Using serial 11C-PiB scans, we calculated wS2 functions from two-dimensional PET images of different cortical regions as well as three-dimensional data from the whole brain. The area under the wS2 functions was calculated and compared with the mean/median of the standardized uptake value ratio (SUVR. For three-dimensional data, we compared the area under the wS2 curves with the subjects’ cerebrospinal fluid measures.Results: Overall, the longitudinal changes in wS2

  5. Noninvasive quantification of muscarinic receptors in vivo with positron emission tomography in the dog heart

    International Nuclear Information System (INIS)

    Delforge, J.; Janier, M.; Syrota, A.; Crouzel, C.; Vallois, J.M.; Cayla, J.; Lancon, J.P.; Mazoyer, B.M.

    1990-01-01

    The in vivo quantification of myocardial muscarinic receptors has been obtained in six closed-chest dogs by using positron emission tomography. The dogs were injected with a trace amount of 11C-labeled methylquinuclidinyl benzilate (MQNB), a nonmetabolized antagonist of the muscarinic receptor. This was followed 30 minutes later by an injection of an excess of unlabeled MQNB (displacement experiment). Two additional injections of unlabeled MQNB with [11C]MQNB and without [11C]MQNB (second displacement experiment) were administered after 70 and 120 minutes, respectively. This protocol allowed a separate evaluation of the quantity of available receptors (B'max) as well as the association and dissociation rate constants (k+1 and k-1) in each dog. The parameters were calculated by using a nonlinear mathematical model in regions of interest over the left ventricle and the interventricular septum. The average value of B'max was 42 +/- 11 pmol/ml tissue, the rate constants k+1, k-1, and Kd were 0.6 +/- 0.1 ml.pmol-1.min-1, 0.27 +/- 0.03 ml.pmol-1.min-1, and 0.49 +/- 0.14 pmol.ml-1, respectively, taking into account the MQNB reaction volume estimated to 0.15 ml/ml tissue. Although [11C]MQNB binding would appear irreversible, our findings indicate that the association of the antagonist is very rapid and that the dissociation is far from negligible. The dissociated ligand, however, has a high probability of rebinding to a free receptor site instead of escaping into the microcirculation. We deduce that the positron emission tomographic images obtained after injecting a trace amount of [11C]MQNB are more representative of blood flow than of receptor density or affinity. We also suggest a simplified protocol consisting of a tracer injection of [11C]MQNB and a second injection of an excess of cold MQNB, which is sufficient to measure B'max and Kd in humans

  6. Positron emission mammography in breast cancer presurgical planning: comparisons with magnetic resonance imaging.

    Science.gov (United States)

    Schilling, Kathy; Narayanan, Deepa; Kalinyak, Judith E; The, Juliette; Velasquez, Maria Victoria; Kahn, Simone; Saady, Matthew; Mahal, Ravinder; Chrystal, Larraine

    2011-01-01

    The objective of this study was to compare the performance characteristics of (18)F-fluorodeoxyglucose (FDG) positron emission mammography (PEM) with breast magnetic resonance imaging (MRI) as a presurgical imaging and planning option for index and ipsilateral lesions in patients with newly diagnosed, biopsy-proven breast cancer. Two hundred and eight women >25 years of age (median age = 59.7 ± 14.1 years) with biopsy-proven primary breast cancer enrolled in this prospective, single-site study. MRI, PEM, and whole-body positron emission tomography (WBPET) were conducted on each patient within 7 business days. PEM and WBPET images were acquired on the same day after intravenous administration of 370 MBq of FDG (median = 432.9 MBq). PEM and MRI images were blindly evaluated, compared with final surgical histopathology, and the sensitivity determined. Substudy analysis compared the sensitivity of PEM versus MRI in patients with different menopausal status, breast density, and use of hormone replacement therapy (HRT) as well as determination of performance characteristics for additional ipsilateral lesion detection. Two hundred and eight patients enrolled in the study of which 87% (182/208) were analyzable. Of these analyzable patients, 26.4% (48/182), 7.1% (13/182), and 64.2% (120/182) were pre-, peri-, and postmenopausal, respectively, and 48.4% (88/182) had extremely or heterogeneously dense breast tissue, while 33.5% (61/182) had a history of HRT use. Ninety-two percent (167/182) underwent core biopsy for index lesion diagnosis. Invasive cancer was found in 77.5% (141/182), while ductal carcinoma in situ (DCIS) and/or Paget's disease were found in 22.5% (41/182) of patients. Both PEM and MRI had index lesion depiction sensitivity of 92.8% and both were significantly better than WBPET (67.9%, p PEM and MRI had equivalent sensitivity of various tumors, categorized by tumor stage as well as similar invasive tumor size predictions with Spearman's correlation

  7. 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

  8. Positron emission tomography with additional γ-ray detectors for multiple-tracer imaging.

    Science.gov (United States)

    Fukuchi, Tomonori; Okauchi, Takashi; Shigeta, Mika; Yamamoto, Seiichi; Watanabe, Yasuyoshi; Enomoto, Shuichi

    2017-06-01

    Positron emission tomography (PET) is a useful imaging modality that quantifies the physiological distributions of radiolabeled tracers in vivo in humans and animals. However, this technique is unsuitable for multiple-tracer imaging because the annihilation photons used for PET imaging have a fixed energy regardless of the selection of the radionuclide tracer. This study developed a multi-isotope PET (MI-PET) system and evaluated its imaging performance. Our MI-PET system is composed of a PET system and additional γ-ray detectors. The PET system consists of pixelized gadolinium orthosilicate (GSO) scintillation detectors and has a ring geometry that is 95 mm in diameter with an axial field of view of 37.5 mm. The additional detectors are eight bismuth germanium oxide (BGO) scintillation detectors, each of which is 50 × 50 × 30 mm 3 , arranged into two rings mounted on each side of the PET ring with a 92-mm-inner diameter. This system can distinguish between different tracers using the additional γ-ray detectors to observe prompt γ-rays, which are emitted after positron emission and have an energy intrinsic to each radionuclide. Our system can simultaneously acquire double- (two annihilation photons) and triple- (two annihilation photons and a prompt γ-ray) coincidence events. The system's efficiency for detecting prompt de-excitation γ-rays was measured using a positron-γ emitter, 22 Na. Dual-radionuclide ( 18 F and 22 Na) imaging of a rod phantom and a mouse was performed to demonstrate the performance of the developed system. Our system's basic performance was evaluated by reconstructing two images, one containing both tracers and the other containing just the second tracer, from list-mode data sets that were categorized by the presence or absence of the prompt γ-ray. The maximum detection efficiency for 1275 keV γ-rays emitted from 22 Na was approximately 7% at the scanner's center, and the minimum detection efficiency was 5.1% at the edge of

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

    International Nuclear Information System (INIS)

    Pizzichemi, M

    2014-01-01

    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

  10. Quantification of myocardial perfusion using cardiac magnetic resonance imaging correlates significantly to rubidium-82 positron emission tomography in patients with severe coronary artery disease

    DEFF Research Database (Denmark)

    Qayyum, Abbas A; Hasbak, Philip; Larsson, Henrik B W

    2014-01-01

    INTRODUCTION: Aim was to compare absolute myocardial perfusion using cardiac magnetic resonance imaging (CMRI) based on Tikhonov's procedure of deconvolution and rubidium-82 positron emission tomography (Rb-82 PET). MATERIALS AND METHODS: Fourteen patients with coronary artery stenosis underwent ...

  11. The predictive role of interim positron emission tomography for Hodgkin lymphoma treatment outcome is confirmed using the interpretation criteria of the Deauville five-point scale

    DEFF Research Database (Denmark)

    Gallamini, Andrea; Barrington, Sally F; Biggi, Alberto

    2014-01-01

    A retrospective, international, multicenter study was undertaken to assess: (i) the prognostic role of 'interim' positron emission tomography performed during treatment with doxorubicin, bleomycin, vinblastine and dacarbazine in patients with Hodgkin lymphoma; and (ii) the reproducibility of the ...

  12. The role of positron emission tomography in mediastinal staging of patients with non-small cell lung cancer.

    Science.gov (United States)

    d'Amico, Andrea; Turska-d'Amico, Maria; Jarzab, Barbara; Zielinski, Marcin

    2015-01-01

    To examine the diagnostic accuracy of positron emission tomography/computed tomography in evaluating the mediastinum of patients with non-small cell lung cancer compared to histopathology results. The prospective study was conducted at the Department of Thoracic Surgery of the Pulmonary Hospital in Zakopane, Poland, from September 2008 to August 2012 and comprised patients with radiologically-suspected lung cancer. All patients underwent histological verification by either mediastinoscopy alone or thoracotomy with mediastinal lymphanedectomy. Computed tomography and positron emission tomography/computed tomography data sets were compared with the results of the histopathology examinations. There were 80 patients in the study. In the diagnosis of mediastinal lymph nodes, computed tomography was able to detect 9(11.25%) true-positive, 17(21.25%) false-positive, 40(50%) true-negative and 14(17.5%) false-negative cases. The sensitivity, specificity and accuracy of the method were found to be 39%, 70% and 61% respectively, while the positive and negative predictive values were 35% and 74%. Positron emission tomography/computed tomography yielded 15(18.75%) true-positive, 12(15%) false-positive, 46(57.5%) true-negative and 7(8.75%) false-negative cases. Sensitivity was 68% while specificity was 79%. The accuracy was 96%, and the positive and negative predictive values were 55% and 87% respectively. Positron emission tomography/computed tomography had higher diagnostic accuracy than computed tomography in assessing mediastinal lymph nodes of patients with non-small cell lung cancer. However, a positive test requires histopathology confirmation.

  13. Head and neck: normal variations and benign findings in FDG positron emission tomography/computed tomography imaging.

    Science.gov (United States)

    Højgaard, Liselotte; Berthelsen, Anne Kiil; Loft, Annika

    2014-04-01

    Positron emission tomography (PET)/computed tomography with FDG of the head and neck region is mainly used for the diagnosis of head and neck cancer, for staging, treatment evaluation, relapse, and planning of surgery and radio therapy. This article is a practical guide of imaging techniques, including a detailed protocol for FDG PET in head and neck imaging, physiologic findings, and pitfalls in selected case stories. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Experimental Evaluation of Depth-of-Interaction Correction in a Small-Animal Positron Emission Tomography Scanner

    OpenAIRE

    Green, Michael V.; Ostrow, Harold G.; Seidel, Jurgen; Pomper, Martin G.

    2010-01-01

    Human and small-animal positron emission tomography (PET) scanners with cylindrical geometry and conventional detectors exhibit a progressive reduction in radial spatial resolution with increasing radial distance from the geometric axis of the scanner. This “depth-of-interaction” (DOI) effect is sufficiently deleterious that many laboratories have devised novel schemes to reduce the magnitude of this effect and thereby yield PET images of greater quantitative accuracy. Here we examine experim...

  15. EEG, transmission computed tomography, and positron emission tomography with fluorodeoxyglucose 18F. Their use in adults with gliomas

    International Nuclear Information System (INIS)

    Newmark, M.E.; Theodore, W.H.; Sato, S.; De La Paz, R.; Patronas, N.; Brooks, R.; Jabbari, B.; Di Chiro, G.

    1983-01-01

    We evaluated the relationship between findings from EEG, transmission computed tomography (CT), and positron emission tomography in 23 adults with gliomas. The cortical metabolic rate was suppressed in patients with and without focal slowing. Focal delta activity was not related to involvement of gray or white matter. Rhythmic delta activity and focal attenuation of background amplitude on EEG, however, were correlated with involvement of the thalamus

  16. Retroperitoneal Endometriosis: A Possible Cause of False Positive Finding at 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

    International Nuclear Information System (INIS)

    Maffione, Anna Margherita; Panzavolta, Riccardo; Lisato, Laura Camilla; Ballotta, Maria; D'Isanto, Mariangela Zanforlini; Rubello, Domenico

    2015-01-01

    Endometriosis is a frequent and clinically relevant problem in young women. Laparoscopy is still the gold standard for the diagnosis of endometriosis, but frequently both morphologic and functional imaging techniques are involved in the diagnostic course before achieving a conclusive diagnosis. We present a case of a patient affected by infiltrating retroperitoneal endometriosis falsely interpreted as a malignant mass by contrast-enhanced magnetic resonance imaging and 18 F-fluorodeoxyglucose positron emission tomography/computed tomography

  17. Positron emission tomography/computed tomography imaging features of renal cell carcinoma and pulmonary metastases in a dog.

    Science.gov (United States)

    Song, Sun-Hye; Park, Noh-Won; Eom, Ki-Dong

    2014-05-01

    A 9-year-old spayed female cocker spaniel dog was referred for hematuria. A large abdominal mass and multiple pulmonary nodules were identified radiographically. A whole-body 2-deoxy-2-[(18)F]fluoro-d-glucose positron emission tomography/computed tomography (PET/CT) scan revealed intensely increased uptake in a renal mass and the pulmonary nodules. Renal cell carcinoma was diagnosed on histological examination.

  18. Positron emission tomography/computed tomography imaging features of renal cell carcinoma and pulmonary metastases in a dog

    OpenAIRE

    Song, Sun-Hye; Park, Noh-Won; Eom, Ki-Dong

    2014-01-01

    A 9-year-old spayed female cocker spaniel dog was referred for hematuria. A large abdominal mass and multiple pulmonary nodules were identified radiographically. A whole-body 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography/computed tomography (PET/CT) scan revealed intensely increased uptake in a renal mass and the pulmonary nodules. Renal cell carcinoma was diagnosed on histological examination.

  19. Comparative analysis of imaging sensitivity of positron emission mammography and whole-body PET in relation to tumor size.

    Science.gov (United States)

    Yamamoto, Yayoi; Ozawa, Yukihiko; Kubouchi, Kouichi; Nakamura, Seigo; Nakajima, Yasuo; Inoue, Tomio

    2015-01-01

    Positron emission mammography (PEM) consists of a dedicated PET scanner for breast imaging with a higher spatial resolution than whole-body PET (WBPET) scanners. This study compared the imaging sensitivity of PEM with WBPET in relation to tumor size. Fifty-four Japanese women younger than 50 years with histologically confirmed breast lesions were retrospectively enrolled. Positron emission mammography and WBPET were conducted on the same day. Positron emission mammography and WBPET images were blindly evaluated and compared with histopathology. Tumors were classified into 3 groups based on size as follows: group 1, 1 cm or smaller; group 2, 1 to 2 cm; and group 3, larger than 2 cm. The sensitivities of PEM and WBPET were compared in overall subjects and in each size group. In visual analysis, the overall imaging sensitivity was 78.6% (33/42) for PEM and 47.6% (20/42) for WBPET. The overall sensitivity of PEM was significantly higher than that of WBPET (P PEM and WBPET were larger in smaller tumors: group 1 (66.7% vs 13.3%), group 2 (63.4% vs 36.4%), and group 3 (100.0% vs 87.5%). The sensitivity of PEM was significantly higher than that of WBPET in group 1 (P = 0.008); however, no significant differences were seen in group 2 (P = 0.500) or group 3 (P = 0.250). Overall, the imaging specificity of PEM and WEBPET was 90.6% (60/66) and 93.9% (62/66), respectively. The imaging sensitivity of PEM was higher than that of WBPET in Japanese women younger than 50 years. Positron emission mammography showed significant sensitivity in tumors smaller than 1 cm, which has been a weak point for WBPET.

  20. Lymphocytic Thyroiditis Presenting as a Focal Uptake on 18F-Fluorodeoxyglucose Positron Emission Tomography: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-12-15

    Diffuse increased uptake on 18F-Fluorodeoxyglucose Positron Emission Tomography (18F FDG PET) is a well-known finding of the lymphocytic thyroiditis. Nevertheless, a pathologic confirmation is needed in cases of a focal 18F FDG uptake in the thyroid gland. This article reports a rare case of a focal 18F FDG uptake lesion by PET, which was revealed pathologically to be lymphocytic thyroiditis

  1. Utility of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in a child with chronic granulomatous disease

    International Nuclear Information System (INIS)

    Garg, Gunjan; DaSilva, Raphaella; Bhalakia, Avni; Milstein, David M.

    2016-01-01

    We report the fluorodeoxyglucose positron emission tomography/computed tomography (FDG - PET/CT) findings in an 11-month-old boy with suspected milk protein allergy, presented to the hospital with 2-month history of fever of unknown origin and failure to thrive. It showed FDG avid lymphadenopathy above and below the diaphragm and splenic focus, which could represent diffuse inflammatory process or lymphoma. Subsequent jejunal biopsy showed non-necrotizing granulomas

  2. In Vivo Treatment Sensitivity Testing With Positron Emission Tomography/Computed Tomography After One Cycle of Chemotherapy for Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    Hutchings, Martin; Kostakoglu, Lale; Zaucha, Jan Maciej

    2014-01-01

    PURPOSE: Negative [(18)F]fluorodeoxyglucose (FDG) -positron emission tomography (PET)/computed tomography (CT) after two cycles of chemotherapy indicates a favorable prognosis in Hodgkin lymphoma (HL). We hypothesized that the negative predictive value would be even higher in patients responding....... In the absence of precise pretherapeutic predictive markers, PET1 is the best method for response-adapted strategies designed to select patients for less intensive treatment....

  3. Multifactorial relationship between 18F-fluoro-deoxy-glucose positron emission tomography signaling and biomechanical properties in unruptured aortic aneurysms.

    Science.gov (United States)

    Nchimi, Alain; Cheramy-Bien, Jean-Paul; Gasser, T Christian; Namur, Gauthier; Gomez, Pierre; Seidel, Laurence; Albert, Adelin; Defraigne, Jean-Olivier; Labropoulos, Nicos; Sakalihasan, Natzi

    2014-01-01

    The relationship between biomechanical properties and biological activities in aortic aneurysms was investigated with finite element simulations and 18F-fluoro-deoxy-glucose (18F-FDG) positron emission tomography. The study included 53 patients (45 men) with aortic aneurysms, 47 infrarenal (abdominal aortic) and 6 thoracic (thoracic aortic), who had ≥1 18F-FDG positron emission tomography/computed tomography. During a 30-month period, more clinical events occurred in patients with increased 18F-FDG uptake on their last examination than in those without (5 of 18 [28%] versus 2 of 35 [6%]; P=0.03). Wall stress and stress/strength index computed by finite element simulations and 18F-FDG uptake were evaluated in a total of 68 examinations. Twenty-five (38%) examinations demonstrated ≥1 aneurysm wall area of increased 18F-FDG uptake. The mean number of these areas per examination was 1.6 (18 of 11) in thoracic aortic aneurysms versus 0.25 (14 of 57) in abdominal aortic aneurysms, whereas the mean number of increased uptake areas colocalizing with highest wall stress and stress/strength index areas was 0.55 (6 of 11) and 0.02 (1 of 57), respectively. Quantitatively, 18F-FDG positron emission tomographic uptake correlated positively with both wall stress and stress/strength index (P<0.05). 18F-FDG uptake was particularly high in subjects with personal history of angina pectoris and familial aneurysm. Increased 18F-FDG positron emission tomographic uptake in aortic aneurysms is strongly related to aneurysm location, wall stress as derived by finite element simulations, and patient risk factors such as acquired and inherited susceptibilities.

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

    International Nuclear Information System (INIS)

    Alonso, O.

    2006-01-01

    (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) [es

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

    International Nuclear Information System (INIS)

    Nyberg, Svante; Cselenyi, Zsolt; Julin, Per; Olsson, Hans; Svensson, Samuel; Eriksdotter Joenhagen, Maria; Freund-Levi, Yvonne; Halldin, Christer; Andersson, Jan; Varnaes, Katarina; Farde, Lars

    2009-01-01

    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 [ 11 C]AZD2184 and report here the first clinical evaluation. Eight AD patients and four younger control subjects underwent 93-min PET measurements with [ 11 C]AZD2184. A ratio approach using the cerebellum as reference region was applied to determine binding parameters. Brain uptake of [ 11 C]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. [ 11 C]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.)

  6. The cerebral blood flow and metabolism for Broca's aphasia using positron emission tomography

    International Nuclear Information System (INIS)

    Kato, Toshiaki

    1987-01-01

    A total of 11 patients with Broca's aphasia (BA) underwent positron emission tomography (PET) with the purpose of investigating the responsible region and the symptomatic flow and metabolism thresholds for BA. Computed tomography (CT) was concurrently performed. In the group of 3 patients undergoing PET with C-11 glucose, both PET and CT provided abnormal findings in the region that is thought to be responsible for BA (Broca's area), including the cortex and subcortex in the anterior region to Sylvian fissure. The Broca's area in the remaining one was shown as low C-11 accumulation area on PET and as isodensity on CT. The second group, consisting of 8 BA patients and 30 control patients without BA, underwent PET using O-15 steady method. PET showed reduction of regional cerebral blood flow (rCBF) and oxygen metabolic rate (rCMRO 2 ) in the Broca's area in all BA patients. Computed tomography showed abnormal low density in the Broca's area in 3 patients, and abnormal findings in the basal ganglionic region and subcortex without evidence for abnormal low density in the Broca's area in the other 5 patients. Comparison of rCBF and rCMRO 2 in BA patients with those in control patients may show the symptomatic thresholds to be 20 - 27 ml/100 g/min for rCBF and 2.0 ml/100 g/min for rCMRO 2 . (Namekawa, K.)

  7. Longitudinal base to apex perfusion gradients by dipyridamole positron emission tomography indicate diffuse coronary atherosclerosis

    International Nuclear Information System (INIS)

    Nakagawa, Yuko

    2001-01-01

    Diffuse coronary atherosclerosis is clinically important and often associated with localized stenosis but is not detected or quantified by current methods including coronary arteriography. Accordingly, I quantified the longitudinal base to apex distribution of N-13 ammonia on positron emission tomography (PET) after dipyridamole stress for 17 normal volunteers and 30 patients with abnormal coronary arteriograms. Heart images were divided into 32 short axis tomographic slices along the long axis, and each slice was divided into anterior, septal, lateral and inferior quadrant. Average relative activity for each slice in each quadrant was graphed against slice number and a third order polynomial curve was best fit to the longitudinal distribution of activity. In the patients group, average relative activity in each quadrant, except septum in mild to moderate disease group, progressively and significantly decreased from base to apex slices compared to normal group, and perfusion decreasing was more progressed in severe disease group. In 12 of the patients with one- or two-vessel disease, longitudinal base to apex perfusion gradient was observed in angiographically stenosis-free quadrant. Thus, patients with segmental coronary artery disease by arteriography have abnormal longitudinal base to apex perfusion gradients on dipyridamole PET images indicating diffuse coronary atherosclerosis. (author)

  8. Fluorine-18 deoxyglucose uptake in sarcoidosis measured with positron emission tomography

    International Nuclear Information System (INIS)

    Brudin, L.H.; Valind, S.O.; Rhodes, C.G.; Pantin, C.F.; Sweatman, M.; Jones, T.; Hughes, J.M.B.

    1994-01-01

    Regional pulmonary glucose metabolism (MR glu ; μmol h -1 g -1 ), extravascular lung density (D EV ; g cm -3 ) and vascular volume (V B ; ml cm -3 ) were measured in a single midthoracic transaxial slice (-2 cm thick) using positron emission tomography (PET) in seven patients with histologically proven sarcoidosis. The measurements were repeated 1-7 months later after steroid therapy (in two cases, no treatment) in order to assess MR glu as an index of inflammation and relate it to routine pulmonary function tests, chest radiography and serum angiotensin converting enzyme (SACE) levels. MR glu was computed from serial lung scans and peripheral venous blood samples for 60 min following an i.v. injection of 18 F-2-fluoro-2-deoxy-D-glucose ( 18 FDG). Both MR glu (which was increased in six of seven patients) and elevated SACE levels returned to normal in those patients treated with high-dose steroids. Regional vascular volume was normal in six of seven cases and did not change significantly with therapy. The high tissue density measured in all patients decreased significantly in two of three patients treated with 40 mg prednisolone daily. The abnormal MR glu observed in active sarcoidosis becomes normal pari passu with SACE levels during high-dose steroid therapy. We conclude that MR glu measured with 18 FDG and PET may reflect ''disease activity'' in sarcoidosis in quantitative terms (per gram lung tissue) and in respect of disease distribution. (orig.)

  9. Positron emission tomography molecular imaging of dopaminergic system in drug addiction.

    Science.gov (United States)

    Hou, Haifeng; Tian, Mei; Zhang, Hong

    2012-05-01

    Dopamine (DA) is involved in drug reinforcement, but its role in drug addiction remains unclear. Positron emission tomography (PET) is the first technology used for the direct measurement of components of the dopaminergic system in the living human brain. In this article, we reviewed the major findings of PET imaging studies on the involvement of DA in drug addiction, especially in heroin addiction. Furthermore, we summarized PET radiotracers that have been used to study the role of DA in drug addiction. To investigate presynaptic function in drug addiction, PET tracers have been developed to measure DA synthesis and transport. For the investigation of postsynaptic function, several radioligands targeting dopamine one (D1) receptor and dopamine two (D2) receptor are extensively used in PET imaging studies. Moreover, we also summarized the PET imaging findings of heroin addiction studies, including heroin-induced DA increases and the reinforcement, role of DA in the long-term effects of heroin abuse, DA and vulnerability to heroin abuse and the treatment implications. PET imaging studies have corroborated the role of DA in drug addiction and increase our understanding the mechanism of drug addiction. Copyright © 2012 Wiley Periodicals, Inc.

  10. Kinetic analysis of [11C]vorozole binding in the human brain with positron emission tomography.

    Science.gov (United States)

    Logan, Jean; Kim, Sung Won; Pareto, Deborah; Telang, Frank; Wang, Gene-Jack; Fowler, Joanna S; Biegon, Anat

    2014-01-01

    Using positron emission tomography, we investigated the kinetics of [11C]vorozole ([11C]VOR), a radiotracer for the enzyme aromatase that catalyzes the last step in estrogen biosynthesis. Six subjects were scanned under baseline conditions followed by retest 2 weeks later. The retest was followed by a blocking study with 2.5 mg of the aromatase inhibitor letrozole. The binding potential (BP(A)ND) was estimated from a Lassen plot using the total tissue distribution volume (VT) for baseline and blocked. for the thalamus was found to be 15 times higher than that for the cerebellum. From the letrozole studies, we found that [11C]VOR exhibits a slow binding compartment (small k4) that has a nonspecific and a blockable component. Because of the sensitivity of VT to variations in k4, a common value was used for the four highest binding regions. We also considered the tissue uptake to plasma ratio for 60 to 90 minutes as an outcome measure. Using the ratio method, the difference between the highest and lowest was 2.4 compared to 3.5 for the VT. The ratio method underestimates the high regions but is less variable and may be more suitable for patient studies. Because of its kinetics and distribution, this tracer is not a candidate for a bolus infusion or reference tissue methods.

  11. Energy discrimination for positron emission tomography using the time information of the first detected photons

    Science.gov (United States)

    Therrien, A. C.; Lemaire, W.; Lecoq, P.; Fontaine, R.; Pratte, J.-F.

    2018-01-01

    The advantages of Time-of-Flight positron emission tomography (TOF-PET) have pushed the development of detectors with better time resolution. In particular, Silicon Photomultipliers (SiPM) have evolved tremendously in the past decade and arrays with a fully digital readout are the next logical step (dSiPM). New multi-timestamp methods use the precise time information of multiple photons to estimate the time of a PET event with greater accuracy, resulting in excellent time resolution. We propose a method which uses the same timestamps as the time estimator to perform energy discrimination, thus using data obtained within 5 ns of the beginning of the event. Having collected all the necessary information, the dSiPM could then be disabled for the remaining scintillation while dedicated electronics process the collected data. This would reduce afterpulsing as the SPAD would be turned off for several hundred nanoseconds, emptying the majority of traps. The proposed method uses a strategy based on subtraction and minimal electronics to reject energy below a selected threshold. This method achieves an error rate of less than 3% for photopeak discrimination (threshold at 400 keV) for dark count rates up to 100 cps/μm2, time-to-digital converter resolution up to 50 ps and a photon detection efficiency ranging from 10 to 70%.

  12. Preparation of a potential positron emission tomographic radioligand for the dopamine transporter

    International Nuclear Information System (INIS)

    Mueller, L.; Halldin, C.; Foged, C.; Karlsson, P.; Hall, H.; Swahn, C.G.; Suzdak, P.D.; Hohlweg, R.; Nielsen, E.B.; Frade, L.

    1994-01-01

    NNC 12-0722 (1-[2-(bis(4-fluorophenyl)-methoxy)ethyl]-4-methyl piperazine) is a new selective inhibitor of the dopamine transporter. [ 11 C]NNC 12-0722 was prepared by N-methylation of the desmethyl compound with [ 11 C]methyl iodide. The total radiochemical yield of [ 11 C]NNC 12-0722 was 40%-50% with an overall synthesis time of 30-35 min. The radiochemical purity was higher than 99% and the specific radioactivity about 1500 Ci/mmol (55 GBq/μmol). Autoradiographic examination of [ 11 C]NNC 12-0722 binding on whole hemisphere cryosections from human brain post mortem demonstrated specific binding in the caudate nucleus and putamen. In a positron emission tomographic examination of [ 11 C]NNC 12-0722 in a cynomolgus monkey there was a rapid uptake of radioactivity in the brain. In the striatum, a region with a high density of dopamine transporters, the radioactivity was two times higher than in the cerebellum. These results indicate that [ 11 C]NNC 12-0722 may be a useful radioligand for labelling of the dopamine transporter in man. (orig.)

  13. A promising new mechanism of ionizing radiation detection for positron emission tomography: Modulation of optical properties

    Science.gov (United States)

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2016-01-01

    Using conventional scintillation detection, the fundamental limit in positron emission tomography (PET) time resolution is strongly dependent on the inherent temporal variances generated during the scintillation process, yielding an intrinsic physical limit for the coincidence time resolution of around 100 ps. On the other hand, modulation mechanisms of the optical properties of a material exploited in the optical telecommunications industry can be orders of magnitude faster. In this paper we borrow from the concept of optics pump-probe measurement to for the first time study whether ionizing radiation can produce modulations of optical properties, which can be utilized as a novel method for radiation detection. We show that a refractive index modulation of approximately 5 × 10−6 is induced by interactions in a cadmium telluride (CdTe) crystal from a 511 keV photon source. Furthermore, using additional radionuclide sources, we show that the amplitude of the optical modulation signal varies linearly with both the detected event rate and average photon energy of the radiation source. PMID:27716640

  14. Ultrafast detection in particle physics and positron emission tomography using SiPMs

    Science.gov (United States)

    Dolenec, R.; Korpar, S.; Križan, P.; Pestotnik, R.

    2017-12-01

    Silicon photomultiplier (SiPM) photodetectors perform well in many particle and medical physics applications, especially where good efficiency, insensitivity to magnetic field and precise timing are required. In Cherenkov time-of-flight positron emission tomography the requirements for photodetector performance are especially high. On average only a couple of photons are available for detection and the best possible timing resolution is needed. Using SiPMs as photodetectors enables good detection efficiency, but the large sensitive area devices needed have somewhat limited time resolution for single photons. We have observed an additional degradation of the timing at very low light intensities due to delayed events in distribution of signals resulting from multiple fired micro cells. In this work we present the timing properties of AdvanSiD ASD-NUV3S-P-40 SiPM at single photon level picosecond laser illumination and a simple modification of the time-walk correction algorithm, that resulted in reduced degradation of timing resolution due to the delayed events.

  15. Is there any role of positron emission tomography computed tomography for predicting resectability of gallbladder cancer?

    Science.gov (United States)

    Kim, Jaihwan; Ryu, Ji Kon; Kim, Chulhan; Paeng, Jin Chul; Kim, Yong-Tae

    2014-05-01

    The role of integrated (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography computed tomography (PET-CT) is uncertain in gallbladder cancer. The aim of this study was to show the role of PET-CT in gallbladder cancer patients. Fifty-three patients with gallbladder cancer underwent preoperative computed tomography (CT) and PET-CT scans. Their medical records were retrospectively reviewed. Twenty-six patients underwent resection. Based on the final outcomes, PET-CT was in good agreement (0.61 to 0.80) with resectability whereas CT was in acceptable agreement (0.41 to 0.60) with resectability. When the diagnostic accuracy of the predictions for resectability was calculated with the ROC curve, the accuracy of PET-CT was higher than that of CT in patients who underwent surgical resection (P=0.03), however, there was no difference with all patients (P=0.12). CT and PET-CT had a discrepancy in assessing curative resection in nine patients. These consisted of two false negative and four false positive CT results (11.3%) and three false negative PET-CT results (5.1%). PET-CT was in good agreement with the final outcomes compared to CT. As a complementary role of PEC-CT to CT, PET-CT tended to show better prediction about resectability than CT, especially due to unexpected distant metastasis.

  16. Positron Emission Tomography Reveals Abnormal Topological Organization in Functional Brain Network in Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Qiu eXiangzhe

    2016-05-01

    Full Text Available Recent studies have demonstrated alterations in the topological organization of structural brain networks in diabetes mellitus (DM. However, the DM-related changes in the topological properties in functional brain networks are almost unexplored so far. We therefore used fluoro-D-glucose positron emission tomography (FDG-PET data to construct functional brain networks of 73 DM patients and 91 sex- and age-matched normal controls (NCs, followed by a graph theoretical analysis. We found that both DM patients and NCs had a small-world topology in functional brain network. In comparison to the NC group, the DM group was found to have significantly lower small-world index, lower normalized clustering coefficients and higher normalized shortest path length. Moreover, for diabetic patients, the nodal centrality was significantly reduced in the right rectus, the right cuneus, the left middle occipital gyrus, and the left postcentral gyrus, and it was significantly increased in the orbitofrontal region of the left middle frontal gyrus, the left olfactory region, and the right paracentral lobule. Our results demonstrated that the diabetic brain was associated with disrupted topological organization in the functional PET network, thus providing the functional evidence for the abnormalities of brain networks in DM.

  17. Detecting Metastatic Bladder Cancer Using (18)F-Fluorodeoxyglucose Positron-Emission Tomography/Computed Tomography.

    Science.gov (United States)

    Öztürk, Hakan

    2015-10-01

    The purpose of this study was to retrospectively investigate the contribution of (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)F-FDG-PET/CT) to detection of metastatic bladder cancer. The present study included 79 patients (69 men and 10 women) undergoing (18)F-FDG-PET/CT upon suspicion of metastatic bladder cancer between July 2007 and April 2013. The mean age was 66.1 years with a standard deviation of 10.7 years (range, 21 to 85 years). Patients were required to fast for 6 hours prior to scanning, and whole-body PET scanning from the skull base to the upper thighs was performed approximately 1 hour after intravenous injection of 555 MBq of (18)F-FDG. Whole body CT scanning was performed in the cranio-caudal direction. FDG-PET images were reconstructed using CT data for attenuation correction. Suspicious recurrent or metastatic lesions were confirmed by histopathology or clinical follow-up. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of (18)F-FDG-PET/CT were 89%, 78%, 90%, 75%, and 86%, respectively. (18)F-FDG-PET/CT can detect metastases with high sensitivity and positive predictive values in patients with metastatic bladder carcinoma.

  18. Methods for modeling and quantification in functional imaging by positron emissions tomography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Costes, Nicolas

    2017-01-01

    This report presents experiences and researches in the field of in vivo medical imaging by positron emission tomography (PET) and magnetic resonance imaging (MRI). In particular, advances in terms of reconstruction, quantification and modeling in PET are described. The validation of processing and analysis methods is supported by the creation of data by simulation of the imaging process in PET. The recent advances of combined PET/MRI clinical cameras, allowing simultaneous acquisition of molecular/metabolic PET information, and functional/structural MRI information opens the door to unique methodological innovations, exploiting spatial alignment and simultaneity of the PET and MRI signals. It will lead to an increase in accuracy and sensitivity in the measurement of biological phenomena. In this context, the developed projects address new methodological issues related to quantification, and to the respective contributions of MRI or PET information for a reciprocal improvement of the signals of the two modalities. They open perspectives for combined analysis of the two imaging techniques, allowing optimal use of synchronous, anatomical, molecular and functional information for brain imaging. These innovative concepts, as well as data correction and analysis methods, will be easily translated into other areas of investigation using combined PET/MRI. (author) [fr

  19. A noninvasive approach to quantitative functional brain mapping with H215O and positron emission tomography

    International Nuclear Information System (INIS)

    Fox, P.T.; Mintun, M.A.; Raichle, M.E.; Herscovitch, P.

    1984-01-01

    Positron emission tomographic (PET) measurements of regional cerebral blood flow (rCBF) with intravenously administered 15 O-labeled water and an adaptation of the Kety autoradiographic model are well suited to the study of functional-anatomical correlations within the human brain. This model requires arterial blood sampling to determine rCBF from the regional tissue radiotracer concentration (Cr) recorded by the tomograph. Based upon the well-defined, nearly linear relation between Cr and rCBF inherent in the model, we have developed a method for estimating changes in rCBF from changes in Cr without calculating true rCBF and thus without arterial sampling. This study demonstrates that quantitative functional brain mapping does not require the determination of rCBF from Cr when regional neuronal activation is expressed as the change in rCBF from an initial, resting-state measurement. Patterned-flash visual stimulation was used to produce a wide range of increases in rCBF within the striate cortex. Changes in occipital rCBF were found to be accurately estimated directly from Cr over a series of 56 measurements on eight subjects. This adaptation of the PET/autoradiographic method serves to simplify its application and to make it more acceptable to the subject

  20. Integrated and automated data analysis for neuronal activation studies using positron emission tomography. Methodology and applications

    International Nuclear Information System (INIS)

    Minoshima, Satoshi; Arimizu, Noboru; Koeppe, R.A.; Kuhl, D.E.

    1994-01-01

    A data analysis method was developed for neuronal activation studies using [ 15 O] water positron emission tomography (PET). The method consists of several procedures including intra-subject head motion correction (co-registration), detection of the mid-sagittal plane of the brain, detection of the intercommissural (AC-PC) line, linear scaling and non-linear warping for anatomical standardization, pixel-by-pixel statistical analysis, and data display. All steps are performed in three dimensions and are fully automated. Each step was validated using a brain phantom, computer simulations, and data from human subjects, demonstrating accuracy and reliability of the procedure. The method was applied to human neuronal activation studies using vibratory and visual stimulations. The method detected significant blood flow increases in the primary sensory cortices as well as in other regions such as the secondary sensory cortex and cerebellum. The proposed method should enhance application of PET neuronal activation studies to the investigation of higher-order human brain functions. (author) 38 refs