WorldWideScience

Sample records for tomography pet instrumentation

  1. Advanced Instrumentation for Positron Emission Tomography [PET

    Science.gov (United States)

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

    1985-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-04-01

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

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

    International Nuclear Information System (INIS)

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

    1986-04-01

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

  4. 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

  5. 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.

  6. Positron Emission Tomography (PET)

    Science.gov (United States)

    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.

  7. Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Rollo, F.D.; Hines, H.

    2001-01-01

    ADAC Laboratories has two main imaging strengths: PET and Gamma Cameras. PET's three-dimensional imaging of metabolic function is used in oncology, with emerging opportunties in cardiology, genetic mapping and pharmaceuticals research. In oncology, PET imaging can provide comprehensive and accurate staging information which is not available from CT or MRI. In some cases, this information can lead to modification of treatment, for example from an aggressive approach to one of palliation. The SKYLight is the world's first and only gantry-free camera. It is a dual-detector variable angle camera designed for high throughput, with unsurpassed openness and patient access. (orig.)

  8. Cost-effectiveness of PET and PET/Computed Tomography

    DEFF Research Database (Denmark)

    Gerke, Oke; Hermansson, Ronnie; Hess, Søren

    2015-01-01

    measure by means of incremental cost-effectiveness ratios when considering the replacement of the standard regimen by a new diagnostic procedure. This article discusses economic assessments of PET and PET/computed tomography reported until mid-July 2014. Forty-seven studies on cancer and noncancer...

  9. THE CHARACTERISTICS OF EEC PET INSTRUMENTATION

    NARCIS (Netherlands)

    PAANS, AMJ

    1991-01-01

    As a result of a Guide-Questionnaire distributed among all European PET centers an inventory of the European PET instrumentation has become available in a data base. An overview and analysis of the European PET equipment, cyclotrons, scanners and software, together with some global information on

  10. 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)

  11. 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

  12. Positron Emission Tomography (PET) in the oncologic clinical practice

    International Nuclear Information System (INIS)

    Serna M, J.A.; Luviano, C.; Martinez V, D.; Maldonado S, A.

    2005-01-01

    We intended to determine the frequency with that the computer axial tomography (TAC), it was able to visualize the lesions extra neoplasia detected by the PET tomography in patients with fully identified primary malignant neoplasia. (Author)

  13. Positron emission tomography (PET) for oncologic applications in oral region

    International Nuclear Information System (INIS)

    Shozushima, Masanori; Terasaki, Kazunori

    2004-01-01

    A rapidly emerging clinical application of positron emission tomography (PET) is the detection of cancer with radionuclide tracer, because it provides information unavailable by ultrasound, computed tomography or magnetic resonance imaging. The most commonly used radiotracer for PET oncologic imaging is fluorine-18-labeled fluorodeoxyglucose ( 18 F-FDG). Early studies show PET has potential value in viewing the region of the tumor, detecting, staging, grading, monitoring response to anticancer therapy, and differentiating recurrent or residual disease from post treatment changes. However, limitations of FDG-PET in the head and neck region, namely, physiological FDG uptake in the salivary glands and palatine tonsils, have been reported, increasing the false-positive rates in image interpretation. This review was designed to address these distinctions of oral cancer PET imaging: specialization of PET equipment, cancer cell metabolism, proliferation and tracers, clinical diagnosis of oral cancer with PET, pitfalls in oncologic diagnosis with FDG-PET imaging. (author)

  14. Compton scatter tomography in TOF-PET

    Science.gov (United States)

    Hemmati, Hamidreza; Kamali-Asl, Alireza; Ay, Mohammadreza; Ghafarian, Pardis

    2017-10-01

    Scatter coincidences contain hidden information about the activity distribution on the positron emission tomography (PET) imaging system. However, in conventional reconstruction, the scattered data cause the blurring of images and thus are estimated and subtracted from detected coincidences. List mode format provides a new aspect to use time of flight (TOF) and energy information of each coincidence in the reconstruction process. In this study, a novel approach is proposed to reconstruct activity distribution using the scattered data in the PET system. For each single scattering coincidence, a scattering angle can be determined by the recorded energy of the detected photons, and then possible locations of scattering can be calculated based on the scattering angle. Geometry equations show that these sites lie on two arcs in 2D mode or the surface of a prolate spheroid in 3D mode, passing through the pair of detector elements. The proposed method uses a novel and flexible technique to estimate source origin locations from the possible scattering locations, using the TOF information. Evaluations were based on a Monte-Carlo simulation of uniform and non-uniform phantoms at different resolutions of time and detector energy. The results show that although the energy uncertainties deteriorate the image spatial resolution in the proposed method, the time resolution has more impact on image quality than the energy resolution. With progress of the TOF system, the reconstruction using the scattered data can be used in a complementary manner, or to improve image quality in the next generation of PET systems.

  15. Positron emission tomography (PET) in psychiatry

    International Nuclear Information System (INIS)

    Buchsbaum, M.S.

    1984-01-01

    In the past the approach to the brain has been necessarily indirect, employing peripheral fluids to assess central and regional neurochemical processes. Blood, urine, skin and muscle biopsy, and cerebrospinal fluid are valuable reflectors of the neurochemical and neuropharmacological activity of the brain, but are removed in time and place from disordered thought processes and diluted by the products of both functional and dysfunctional brain systems. Biopsy studies have helped in studying the functional disorders of organs like the liver, but they are destructive to the brain and less useful because unlike these organs, the brain has a regional variation in its chemistry. The experimental insights from animal studies focusing on the pharmacology of individual cell groups - in striatum or locus coeruleus, for example - cannot easily or unambigiously be applied to clinical populations. Positron emission tomography (PET) is a versatile approach utilizing the mathematics of x-ray transmission scanning (CT scanning) to produce slice images of radioisotope distribution. PET makes possible a wide range of metabolic studies. Positron emitters such as carbon-11 or fluorine-18 can be used to label glucose, amino acids, drugs, neurotransmitter precursors, and many other molecules and examine their distribution and fate in discrete cell groups

  16. 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...

  17. Early-Dynamic Positron Emission Tomography (PET)/Computed Tomography and PET Angiography for Endoleak Detection After Endovascular Aneurysm Repair.

    Science.gov (United States)

    Drescher, Robert; Gühne, Falk; Freesmeyer, Martin

    2017-06-01

    To propose a positron emission tomography (PET)/computed tomography (CT) protocol including early-dynamic and late-phase acquisitions to evaluate graft patency and aneurysm diameter, detect endoleaks, and rule out graft or vessel wall inflammation after endovascular aneurysm repair (EVAR) in one examination without intravenous contrast medium. Early-dynamic PET/CT of the endovascular prosthesis is performed for 180 seconds immediately after intravenous injection of F-18-fluorodeoxyglucose. Data are reconstructed in variable time frames (time periods after tracer injection) to visualize the arterial anatomy and are displayed as PET angiography or fused with CT images. Images are evaluated in view of vascular abnormalities, graft configuration, and tracer accumulation in the aneurysm sac. Whole-body PET/CT is performed 90 to 120 minutes after tracer injection. This protocol for early-dynamic PET/CT and PET angiography has the potential to evaluate vascular diseases, including the diagnosis of complications after endovascular procedures.

  18. Instrumentation for positron emission tomography

    International Nuclear Information System (INIS)

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

    1984-01-01

    Positron emission tomography with a spatial resolution of 2 mm full width at half maximum for quantitation in regions of interest 4 mm in diameter will become possible with the development of detectors that achieve ultrahigh resolution. Improved resolution will be possible using solid-state photodetectors for crystal identification or photomultiplier tubes with many small electron multipliers. Temporal resolution of 2 seconds and gating of cyclic events can be accomplished if statistical requirements are met. The major physical considerations in achieving high-resolution positron emission tomography are the degradation in resolution resulting from positron range, emission angle, parallax error, detector sampling density, the sensitivity of various detector materials and packing schemes, and the tradeoff between temporal resolution and statistical accuracy. The accuracy of data required for physiological models depends primarily on the fidelity of spatial sampling independent of statistical constraints

  19. 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

  20. 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

  1. 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

  2. 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].

  3. Positron emission tomography (PET) and pancreatic tumours

    International Nuclear Information System (INIS)

    Montravers, F.; Kerrou, K.; Grahek, D.; Gutman, F.; Beco, V. de; Talbot, J.N.

    2005-01-01

    Neoplasms of the pancreas may originate front both exocrine and endocrine cells but in 90% of the cases, they correspond to ductal adenocarcinomas. For adenocarcinomas, the major indication of FDG-PET corresponds to the pre-operative staging because unexpected distant metastases can be detected by FDG-PET in about 20 to 40% of the cases, which results in avoidance of unnecessary surgical procedures. FDG PET is also useful in evaluation of the treatment effect, monitoring after the operation and detection of recurrent pancreatic cancers. For the characterisation of the pancreatic tumour, the performance of FDG-PET is sometimes limited due to poor cellularity, hyperglycemia or inflammatory processes. especially for large tumours and is indicated only in cases of doubtful results of CT or MRI. For endocrine pancreatic tumours, FDG-PET is useful only in case of poorly-differentiated and aggressive tumours. F-DOPA PET can he useful, complementary to pentetreotide scintigraphy, in well-differentiated endocrine tumours. (authors)

  4. Physics and instrumentation of emission computed tomography

    International Nuclear Information System (INIS)

    Links, J.M.

    1986-01-01

    Transverse emission computed tomography can be divided into two distinct classes: single photon emission computed tomography (SPECT) and positron emission tomography (PET). SPECT is usually accomplished with specially-adapted scintillation cameras, although dedicated SPECT scanners are available. The special SPECT cameras are standard cameras which are mounted on gantries that allow 360 degree rotation around the long axis of the head or body. The camera stops at a number of angles around the body (usually 64-128), acquiring a ''projection'' image at each stop. The data from these projections are used to reconstruct transverse images with a standard ''filtered back-projection'' algorithm, identical to that used in transmission CT. Because the scintillation camera acquires two-dimensional images, a simple 360 degree rotation around the patient results in the acquisition of data for a number of contiguous transverse slices. These slices, once reconstructed, can be ''stacked'' in computer memory, and orthogonal coronal and sagittal slices produced. Additionally, reorienting algorithms allow the generation of slices that are oblique to the long axis of the body

  5. Positron Emission Tomography (PET in Oncology

    Directory of Open Access Journals (Sweden)

    Andrea Gallamini

    2014-09-01

    Full Text Available Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV and the total amount of tumor glycolysis (TLG. FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%–15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later.

  6. Positron Emission Tomography (PET) in Oncology

    Energy Technology Data Exchange (ETDEWEB)

    Gallamini, Andrea, E-mail: gallamini.a@ospedale.cuneo.it [Department of Research and Medical Innovation, Antoine Lacassagne Cancer Center, Nice University, Nice Cedex 2-06189 Nice (France); Zwarthoed, Colette [Department of Nuclear Medicine, Antoine Lacassagne Cancer Center, Nice University, Nice Cedex 2-06189 Nice (France); Borra, Anna [Hematology Department S. Croce Hospital, Via M. Coppino 26, Cuneo 12100 (Italy)

    2014-09-29

    Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV) and the total amount of tumor glycolysis (TLG). FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%–15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later.

  7. Technical and instrumentational foundations of PET/MRI

    NARCIS (Netherlands)

    Rausch, Ivo; Quick, Harald H.; Cal-Gonzalez, Jacobo; Sattler, Bernhard; Boellaard, Ronald; Beyer, Thomas

    This paper highlights the origins of combined positron emission tomography (PET) and magnetic resonance imaging (MRI) whole-body systems that were first introduced for applications in humans in 2010. This text first covers basic aspects of each imaging modality before describing the technical and

  8. Positron Emission Tomography (PET) in the oncologic clinical practice; Tomografia por Emision de Positrones (PET) en la practica clinica oncologica

    Energy Technology Data Exchange (ETDEWEB)

    Serna M, J A; Luviano, C; Martinez V, D [Hospital Angeles del Pedregal Mexico DF (Mexico); Maldonado S, A [Centro PET Complutense, Madrid (Spain)

    2005-07-01

    We intended to determine the frequency with that the computer axial tomography (TAC), it was able to visualize the lesions extra neoplasia detected by the PET tomography in patients with fully identified primary malignant neoplasia. (Author)

  9. Positron emission tomography (PET) in psychiatry. PET in der Psychiatrie

    Energy Technology Data Exchange (ETDEWEB)

    Herholz, K [Max-Planck-Institut fuer Neurologische Forschung und Neurologische Klinik der Universitaet Koeln (Germany)

    1993-08-13

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

  10. Positron emission tomography (PET) in psychiatry. PET in der Psychiatrie

    Energy Technology Data Exchange (ETDEWEB)

    Herholz, K. (Max-Planck-Institut fuer Neurologische Forschung und Neurologische Klinik der Universitaet Koeln (Germany))

    1993-08-13

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

  11. PET/CT: underlying physics, instrumentation, and advances.

    Science.gov (United States)

    Torres Espallardo, I

    Since it was first introduced, the main goal of PET/CT has been to provide both PET and CT images with high clinical quality and to present them to radiologists and specialists in nuclear medicine as a fused, perfectly aligned image. The use of fused PET and CT images quickly became routine in clinical practice, showing the great potential of these hybrid scanners. Thanks to this success, manufacturers have gone beyond considering CT as a mere attenuation corrector for PET, concentrating instead on design high performance PET and CT scanners with more interesting features. Since the first commercial PET/CT scanner became available in 2001, both the PET component and the CT component have improved immensely. In the case of PET, faster scintillation crystals with high stopping power such as LYSO crystals have enabled more sensitive devices to be built, making it possible to reduce the number of undesired coincidence events and to use time of flight (TOF) techniques. All these advances have improved lesion detection, especially in situations with very noisy backgrounds. Iterative reconstruction methods, together with the corrections carried out during the reconstruction and the use of the point-spread function, have improved image quality. In parallel, CT instrumentation has also improved significantly, and 64- and 128-row detectors have been incorporated into the most modern PET/CT scanners. This makes it possible to obtain high quality diagnostic anatomic images in a few seconds that both enable the correction of PET attenuation and provide information for diagnosis. Furthermore, nowadays nearly all PET/CT scanners have a system that modulates the dose of radiation that the patient is exposed to in the CT study in function of the region scanned. This article reviews the underlying physics of PET and CT imaging separately, describes the changes in the instrumentation and standard protocols in a combined PET/CT system, and finally points out the most important

  12. Positron emission tomography (PET) in psychiatry

    International Nuclear Information System (INIS)

    Herholz, K.

    1993-01-01

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

  13. Modern imaging methods: positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) combination

    International Nuclear Information System (INIS)

    Votrubova, J.; Belohlavek, O.

    2004-01-01

    An overview of the title topic is presented. Attention is paid to the technical principles of PET and CT, indications for PET and PET/CT examination, and achievements of the PET Centre of the Na Homolce hospital. (P.A.)

  14. Positron Emission Tomography imaging with the SmartPET system

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, R.J. [Department of Physics, University of Liverpool, Liverpool, Merseyside L69 7ZE (United Kingdom)], E-mail: cooperrj@ornl.gov; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Grint, A.N.; Harkness, L.J.; Nolan, P.J.; Oxley, D.C.; Scraggs, D.P.; Mather, A.R. [Department of Physics, University of Liverpool, Liverpool, Merseyside L69 7ZE (United Kingdom); Lazarus, I.; Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom)

    2009-07-21

    The Small Animal Reconstruction Tomograph for Positron Emission Tomography (SmartPET) project is the development of a small animal Positron Emission Tomography (PET) demonstrator based on the use of High-Purity Germanium (HPGe) detectors and state of the art digital electronics. The experimental results presented demonstrate the current performance of this unique system. By performing high precision measurements of one of the SmartPET HPGe detectors with a range of finely collimated gamma-ray beams the response of the detector as a function of gamma-ray interaction position has been quantified, facilitating the development of parametric Pulse Shape Analysis (PSA) techniques and algorithms for the correction of imperfections in detector performance. These algorithms have then been applied to data from PET imaging measurements using two such detectors in conjunction with a specially designed rotating gantry. In this paper we show how the use of parametric PSA approaches allows over 60% of coincident events to be processed and how the nature and complexity of an event has direct implications for the quality of the resulting image.

  15. 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

  16. Precision Medicine and PET/Computed Tomography: Challenges and Implementation.

    Science.gov (United States)

    Subramaniam, Rathan M

    2017-01-01

    Precision Medicine is about selecting the right therapy for the right patient, at the right time, specific to the molecular targets expressed by disease or tumors, in the context of patient's environment and lifestyle. Some of the challenges for delivery of precision medicine in oncology include biomarkers for patient selection for enrichment-precision diagnostics, mapping out tumor heterogeneity that contributes to therapy failures, and early therapy assessment to identify resistance to therapies. PET/computed tomography offers solutions in these important areas of challenges and facilitates implementation of precision medicine. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Dual-modality PET/CT instrumentation-today and tomorrow

    DEFF Research Database (Denmark)

    Lonsdale, Markus Nowak; Beyer, Thomas

    2010-01-01

    Positron emission tomography (PET) has proven to be a clinically valuable imaging modality, particularly for oncology staging and therapy follow-up. The introduction of combined PET/CT imaging has helped address challenging imaging situations when anatomical information on PET-only was inadequate...

  18. TH-A-17A-01: Innovation in PET Instrumentation and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Casey, M [Siemens Healthcare, Knoxville, Tennessee (United States); Miyaoka, R [University of Washington, Seattle, WA (United States); Shao, Y [University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    Innovation in PET instrumentation has led to the new millennium revolutionary imaging applications for diagnosis, therapeutic guidance, and development of new molecular imaging probes, etc. However, after several decades innovations, will the advances of PET technology and applications continue with the same trend and pace? What will be the next big thing beyond the PET/CT, PET/MRI, and Time-of-flight PET? How will the PET instrumentation and imaging performance be further improved by novel detector research and advanced imaging system development? Or will the development of new algorithms and methodologies extend the limit of current instrumentation and leapfrog the imaging quality and quantification for practical applications? The objective of this session is to present an overview of current status and advances in the PET instrumentation and applications with speakers from leading academic institutes and a major medical imaging company. Presenting with both academic research projects and commercial technology developments, this session will provide a glimpse of some latest advances and challenges in the field, such as using semiconductor photon-sensor based PET detectors to improve performance and enable new applications, as well as the technology trend that may lead to the next breakthrough in PET imaging for clinical and preclinical applications. Both imaging and image-guided therapy subjects will be discussed. Learning Objectives: Describe the latest innovations in PET instrumentation and applications Understand the driven force behind the PET instrumentation innovation and development Learn the trend of PET technology development for applications.

  19. TH-A-17A-01: Innovation in PET Instrumentation and Applications

    International Nuclear Information System (INIS)

    Casey, M; Miyaoka, R; Shao, Y

    2014-01-01

    Innovation in PET instrumentation has led to the new millennium revolutionary imaging applications for diagnosis, therapeutic guidance, and development of new molecular imaging probes, etc. However, after several decades innovations, will the advances of PET technology and applications continue with the same trend and pace? What will be the next big thing beyond the PET/CT, PET/MRI, and Time-of-flight PET? How will the PET instrumentation and imaging performance be further improved by novel detector research and advanced imaging system development? Or will the development of new algorithms and methodologies extend the limit of current instrumentation and leapfrog the imaging quality and quantification for practical applications? The objective of this session is to present an overview of current status and advances in the PET instrumentation and applications with speakers from leading academic institutes and a major medical imaging company. Presenting with both academic research projects and commercial technology developments, this session will provide a glimpse of some latest advances and challenges in the field, such as using semiconductor photon-sensor based PET detectors to improve performance and enable new applications, as well as the technology trend that may lead to the next breakthrough in PET imaging for clinical and preclinical applications. Both imaging and image-guided therapy subjects will be discussed. Learning Objectives: Describe the latest innovations in PET instrumentation and applications Understand the driven force behind the PET instrumentation innovation and development Learn the trend of PET technology development for applications

  20. Tomography methods for diagnostic examination of cerebrovascular disease: a comparative evaluation of SPECT, PET and MR/CT findings

    International Nuclear Information System (INIS)

    Reiche, W.; Kaiser, H.J.; Weiller, C.; Altehoefer, C.; Buell, U.; Isensee, C.

    1991-01-01

    Single Photon Emissions Computerized Tomography (SPECT), Positron Emissions Tomography (PET), Magnetic Resonance Tomography (MR), and Transmission Computerized Tomography (CT) complement each other and lead to a consideration of the cerebrovascular disease under patho-physiological aspects. Indications for the combined application of functionally oriented (SPECT/PET) and morphologically oriented (CT/MR) examination methods with cerebrovascular disease are presented. (orig./MG) [de

  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. An economic evaluation of positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) for the diagnosis of breast cancer recurrence.

    Science.gov (United States)

    Auguste, P; Barton, P; Hyde, C; Roberts, T E

    2011-04-01

    To review the published economic studies that have evaluated positron emission tomography/computed tomography (PET/CT) in the treatment of recurrent breast cancer, and to develop and carry out a model-based economic evaluation to investigate the relative cost-effectiveness of PET/CT to detect breast cancer recurrence compared with conventional work-up. A systematic review of economic and diagnostic evidence for PET/CT in diagnosis of breast cancer recurrence. The original databases searched include MEDLINE (Ovid) (1950 to week 5 May 2009), EMBASE (Ovid) (1980 to 2009 week 22) and the NHS Economic Evaluation Database. An updated search was conducted for each database from May 2009 to week 4 April 2010. A decision tree was developed in TREEAGE software (TreeAge Software Inc., Williamstown, MA, USA). The relevant data on accuracy, sensitivity and specificity of each diagnostic test were linked in the model, to costs and the primary outcome measure, cost per quality-adjusted life-year (QALY). The model estimated the mean cost associated with each diagnostic procedure and assumed that patients entering the model were aged 50-75 years. The results of the cost-effectiveness analysis are presented in terms of the incremental cost-effectiveness ratios (ICERs). The ICER for the strategy of PET compared with conventional work-up was estimated at £29,300 per QALY; the ICER for PET/CT compared with PET was £ 31,000 per QALY; and the ICER for PET/CT combined with conventional work-up versus PET/CT was £ 42,100. Clearly, for each additional diagnostic test that is added to PET, the more expensive the package becomes, but also the more effective it becomes in terms of QALYs gained. The probabilistic sensitivity analysis shows that at a willingness-to-pay threshold of £ 20,000 per QALY, conventional work-up is the preferred option. Only data from indirect comparisons are available from the accuracy review, and there is some uncertainty about whether the data defining the

  3. Instrumentation for three-dimensional tomography

    International Nuclear Information System (INIS)

    Derenzo, S.E.

    1981-01-01

    The Donner 280-crystal positron tomograph is described and its operation is explained. The instrument was put into operation in 1978. Possible uses of this instrument in human and animal studies are given

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

    International Nuclear Information System (INIS)

    Aguilar, P.; Couce, B.; Iglesias, A.; Lois, C.

    2011-01-01

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

  5. 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...

  6. 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.

  7. Positron Emission Tomography (PET) Evaluation After Initial Chemotherapy and Radiation Therapy Predicts Local Control in Rhabdomyosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Dharmarajan, Kavita V., E-mail: dharmark@mskcc.org [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States); Wexler, Leonard H.; Gavane, Somali; Fox, Josef J.; Schoder, Heiko; Tom, Ashlyn K.; Price, Alison N.; Meyers, Paul A.; Wolden, Suzanne L. [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States)

    2012-11-15

    Purpose: 18-fluorodeoxyglucose positron emission tomography (PET) is already an integral part of staging in rhabdomyosarcoma. We investigated whether primary-site treatment response characterized by serial PET imaging at specific time points can be correlated with local control. Patients and Methods: We retrospectively examined 94 patients with rhabdomyosarcoma who received initial chemotherapy 15 weeks (median) before radiotherapy and underwent baseline, preradiation, and postradiation PET. Baseline PET standardized uptake values (SUVmax) and the presence or absence of abnormal uptake (termed PET-positive or PET-negative) both before and after radiation were examined for the primary site. Local relapse-free survival (LRFS) was calculated according to baseline SUVmax, PET-positive status, and PET-negative status by the Kaplan-Meier method, and comparisons were tested with the log-rank test. Results: The median patient age was 11 years. With 3-year median follow-up, LRFS was improved among postradiation PET-negative vs PET-positive patients: 94% vs 75%, P=.02. By contrast, on baseline PET, LRFS was not significantly different for primary-site SUVmax {<=}7 vs >7 (median), although the findings suggested a trend toward improved LRFS: 96% for SUVmax {<=}7 vs 79% for SUVmax >7, P=.08. Preradiation PET also suggested a statistically insignificant trend toward improved LRFS for PET-negative (97%) vs PET-positive (81%) patients (P=.06). Conclusion: Negative postradiation PET predicted improved LRFS. Notably, 77% of patients with persistent postradiation uptake did not experience local failure, suggesting that these patients could be closely followed up rather than immediately referred for intervention. Negative baseline and preradiation PET findings suggested statistically insignificant trends toward improved LRFS. Additional study may further understanding of relationships between PET findings at these time points and outcome in rhabdomyosarcoma.

  8. Evaluation of dosimetric techniques in positrons emission tomography and computerized tomography (PET/CT)

    International Nuclear Information System (INIS)

    Pinto, Gabriella Montezano

    2014-01-01

    Among diagnostic techniques PET/CT is one of those with the highest dose delivery to the patient as a cause of external exposure to X-rays, and the use of a radiopharmaceutical that results in a high energy gamma emission. The dosimetry of these two components becomes important in order to optimize and justify the technique. Various dosimetric techniques are found in literature without a consensus of the best to use. With the advances in technological and consequent equipment configuration changes, upgrades and variation in methodologies, particularly in computed tomography, a standardization of these techniques is required. Previous studies show that CT is responsible for 70 % of the dose delivered to the patient in PET/CT examinations. Thus, many researchers have been focused on CT dose optimization protocols studies. This work analyzes the doses involved in a PET/CT oncology protocol by using an Alderson female anthropomorphic phantom in a public hospital of Rio de Janeiro city. The dose estimate for PET examination resulting from the use of 18 F - FDG radiopharmaceutical was conducted through dose factors published in ICRP 106; the dose for CT was estimated and compared by calculation of the absorbed doses to patients according to four methods: thermoluminescent dosimetry (TL0100) distributed in critical organs of the Alderson phantom; measurements of CTOI according to AAPM number 96; correction factor for effective diameter SSOE (AAPM Number 204); and simulation by ImPACT program For CT, the results in terms of effective dose presented (TLO, CTOI and ImPACT) ± 5 % maximum variations between methodologies. Considering medium absorbed dose (TLO, SSOE and ImPACT) the results differed in ± 7 % from each other. These findings demonstrate that parameters provided by the manufacturer on the console can be used to have a primary approach of both, absorbed and effective doses to the patient since that a quality assurance program of these parameters are adopted in

  9. Magnetic resonance imaging-guided attenuation correction of positron emission tomography data in PET/MRI

    OpenAIRE

    Izquierdo-Garcia, David; Catana, Ciprian

    2016-01-01

    Attenuation correction (AC) is one of the most important challenges in the recently introduced combined positron emission tomography/magnetic resonance imaging (PET/MR) scanners. PET/MR AC (MR-AC) approaches aim to develop methods that allow accurate estimation of the linear attenuation coefficients (LACs) of the tissues and other components located in the PET field of view (FoV). MR-AC methods can be divided into three main categories: segmentation-, atlas- and PET-based. This review aims to...

  10. Molecular Imaging and Precision Medicine: PET/Computed Tomography and Therapy Response Assessment in Oncology.

    Science.gov (United States)

    Sheikhbahaei, Sara; Mena, Esther; Pattanayak, Puskar; Taghipour, Mehdi; Solnes, Lilja B; Subramaniam, Rathan M

    2017-01-01

    A variety of methods have been developed to assess tumor response to therapy. Standardized qualitative criteria based on 18F-fluoro-deoxyglucose PET/computed tomography have been proposed to evaluate the treatment effectiveness in specific cancers and these allow more accurate therapy response assessment and survival prognostication. Multiple studies have addressed the utility of the volumetric PET biomarkers as prognostic indicators but there is no consensus about the preferred segmentation methodology for these metrics. Heterogeneous intratumoral uptake was proposed as a novel PET metric for therapy response assessment. PET imaging techniques will be used to study the biological behavior of cancers during therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Analysis of human cerebral functions using positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Shibasaki, Takashi

    1984-01-01

    Positron emission tomography has two major advantages to analyse human cerebral functions in vivo. First, we can see the distribution of a variety of substance in the living (and doing something) human brain. Positron emitters, 11 C, 13 N, 15 O and 18 F, are made by medical cyclotron and are elements of natural substrates or easily tagged to substrate. Second, the distribution of the tracer is calculated to make a quantitative functional map in a reasonable spatial resolution over the entire brain in the same time. Not only cortical areas but also deeper structures show regional cerebral blood flow (rCBF) or local cerebral metabolic rates (LCMRs). Nowadays, PET is put to practical use for determination of mainly rCBF, LCMR for glucose (LCMRsub(glu)), LCMR for oxygen (LCMRsub(o2)) and regional cerebral blood volume (rCBV). There have been many other pilot studies, such as estimation of distribution of given neurotransmitters or modulators in the brain which also confirms the substances' role in the neuronal function, and observation of protein synthesis relating to memory function. (J.P.N.)

  12. 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.

  13. Trends in PET imaging

    International Nuclear Information System (INIS)

    Moses, William W.

    2000-01-01

    Positron Emission Tomography (PET) imaging is a well established method for obtaining information on the status of certain organs within the human body or in animals. This paper presents an overview of recent trends PET instrumentation. Significant effort is being expended to develop new PET detector modules, especially those capable of measuring depth of interaction. This is aided by recent advances in scintillator and pixellated photodetector technology. The other significant area of effort is development of special purpose PET cameras (such as for imaging breast cancer or small animals) or cameras that have the ability to image in more than one modality (such as PET / SPECT or PET / X-Ray CT)

  14. PET with a dual-head coincidence gamma camera in head and neck cancer: A comparison with computed tomography and dedicated PET

    International Nuclear Information System (INIS)

    Zimny, M.

    2001-01-01

    Positron emission tomography with 18 F-fluoro-deoxyglucose (FDG PET) is a promising imaging tool for detecting and staging of primary or recurrent head and neck cancer. The aim of this study was to evaluate a dual-head gamma camera modified for coincidence detection (KGK-PET) in comparison to computed tomography (CT) and dedicated PET (dPET). 50 patients with known or suspected primary or recurrent head and neck cancer were enrolled. 32 patients underwent KGK-PET and dPET using a one-day protocol. The sensitivity for the detection of primary/ recurrent head and neck cancer for KGK-PET and CT was 80% and 54%, respectively, specificity was 73% and 82%, respectively. The sensitivity and specificity for the detection of lymph node metastases based on neck sides with KGK-PET was 71% (CT: 65%) and 88% (CT: 89%) respectively. In comparison to dPET, KGK-PET revealed concordant results in 32/32 patients with respect to primary tumor/recurrent disease and in 55/60 evaluated neck sides. All involved neck sides that were missed by KGK-PET were also negative with dPET. These results indicate that in patients with head and neck cancer KGK-PET reveals information, that are similar to dPET and complementary to CT. (orig.) [de

  15. 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

  16. Lung PET scan

    Science.gov (United States)

    ... Chest PET scan; Lung positron emission tomography; PET - chest; PET - lung; PET - tumor imaging; ... Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging . 6th ed. Philadelphia, ...

  17. Fabrication of polycrystalline scintillators for the positron emission tomography (PET); Herstellung polykristalliner Szintillatoren fuer die Positronen-Emissions-Tomographie (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Karim, Kamran Said

    2010-07-01

    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{sub 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

  18. Positron Emission Tomography (PET) Imaging of Opioid Receptors

    NARCIS (Netherlands)

    van Waarde, Aren; Absalom, Anthony; Visser, Anniek; Dierckx, Rudi; Dierckx, Rudi AJO; Otte, Andreas; De Vries, Erik FJ; Van Waarde, Aren; Luiten, Paul GM

    2014-01-01

    The opioid system consists of opioid receptors (which mediate the actions of opium), their endogenous ligands (the enkephalins, endorphins, endomorphins, dynorphin, and nociceptin), and the proteins involved in opioid production, transport, and degradation. PET tracers for the various opioid

  19. Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

    International Nuclear Information System (INIS)

    Brady, Samuel L.; Shulkin, Barry L.

    2015-01-01

    Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV bw ) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV bw , background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake

  20. Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Brady, Samuel L., E-mail: samuel.brady@stjude.org [Division of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105 (United States); Shulkin, Barry L. [Nuclear Medicine and Department of Radiological Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105 (United States)

    2015-02-15

    Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV{sub bw}) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV{sub bw}, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake.

  1. Magnetic resonance imaging-guided attenuation correction of positron emission tomography data in PET/MRI

    Science.gov (United States)

    Izquierdo-Garcia, David; Catana, Ciprian

    2018-01-01

    Synopsis Attenuation correction (AC) is one of the most important challenges in the recently introduced combined positron emission tomography/magnetic resonance imaging (PET/MR) scanners. PET/MR AC (MR-AC) approaches aim to develop methods that allow accurate estimation of the linear attenuation coefficients (LACs) of the tissues and other components located in the PET field of view (FoV). MR-AC methods can be divided into three main categories: segmentation-, atlas- and PET-based. This review aims to provide a comprehensive list of the state of the art MR-AC approaches as well as their pros and cons. The main sources of artifacts such as body-truncation, metallic implants and hardware correction will be presented. Finally, this review will discuss the current status of MR-AC approaches for clinical applications. PMID:26952727

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

    DEFF Research Database (Denmark)

    Honoré, Per Gustaf Hartvig; Lundquist, Pinelopi

    -L-(beta-11C tryptophan) (5HTP) quantifies the activity of amino acid decarboxylase in the conversion to 5HT. On the other hand, alpha-methyl-tryptophan (AMT) measures the conversion to the corresponding 5-hydroxytryptophan analogue. The irreversible binding of the PET probe 5HTP in the monkey brain was lower...... evaluations of neuroendocrine tumours. Though, a few studies using 5HT have been conducted on CNS disorders. AMT-PET studies have mainly been confined to brain diseases causing various degree of neurodegeneration....

  3. Precision Medicine and PET/Computed Tomography in Melanoma.

    Science.gov (United States)

    Mena, Esther; Sanli, Yasemin; Marcus, Charles; Subramaniam, Rathan M

    2017-10-01

    Recent advances in genomic profiling and sequencing of melanoma have provided new insights into the development of the basis for molecular biology to more accurately subgroup patients with melanoma. The development of novel mutation-targeted and immunomodulation therapy as a major component of precision oncology has revolutionized the management and outcome of patients with metastatic melanoma. PET imaging plays an important role in noninvasively assessing the tumor biological behavior, to guide individualized treatment and assess response to therapy. This review summarizes the recent genomic discoveries in melanoma in the era of targeted therapy and their implications for functional PET imaging. Published by Elsevier Inc.

  4. Evaluation of therapy response in breast and ovarian cancer patients by positron emission tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Baum, R. P.; Przetak, C. [Zentralklinik Bad Berka, Clinic of Nuclear Medicine, Center for PET, Bad Berka (Germany)

    2001-09-01

    Positron emission tomography (PET) has the potential to contribute significantly to treatment planning and to the evaluation of response to therapy in patients with cancer. For disease recurrence PET imaging provides information non-invasively. The final goal is to biologically characterize an individual patients' tumor and to predict the response to treatment at the earliest possible time. Quantitative and/or semi-quantitative PET studies yield valuable information in breast cancer regarding prognosis and response to chemohormontherapy in a timely fashion. In ovarian cancer, up to now only few studies have been performed applying PET techniques for the evaluation of treatment response. These preliminary studies indicate that serial assessment of tumor metabolism by FDG-PET early during effective chemotherapy may predict subsequent response to such therapy. PET studies can be repeated without any side-effects and with low radiation exposure and results can be directly correlated with clinical laboratory data and histology. Therapy monitoring by PET could help to optimize neoadjuvant therapy protocols and to avoid ineffective preoperative therapy in non-responders, but this has to be proven in a larger number of patients and in different neoadjuvant settings such as chemotherapy, radiation therapy, hormone therapy or a combination of these.

  5. Evaluation of therapy response in breast and ovarian cancer patients by positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Baum, R. P.; Przetak, C.

    2001-01-01

    Positron emission tomography (PET) has the potential to contribute significantly to treatment planning and to the evaluation of response to therapy in patients with cancer. For disease recurrence PET imaging provides information non-invasively. The final goal is to biologically characterize an individual patients' tumor and to predict the response to treatment at the earliest possible time. Quantitative and/or semi-quantitative PET studies yield valuable information in breast cancer regarding prognosis and response to chemohormontherapy in a timely fashion. In ovarian cancer, up to now only few studies have been performed applying PET techniques for the evaluation of treatment response. These preliminary studies indicate that serial assessment of tumor metabolism by FDG-PET early during effective chemotherapy may predict subsequent response to such therapy. PET studies can be repeated without any side-effects and with low radiation exposure and results can be directly correlated with clinical laboratory data and histology. Therapy monitoring by PET could help to optimize neoadjuvant therapy protocols and to avoid ineffective preoperative therapy in non-responders, but this has to be proven in a larger number of patients and in different neoadjuvant settings such as chemotherapy, radiation therapy, hormone therapy or a combination of these

  6. PET, Positron emission tomography: Presentation of a clinical case

    International Nuclear Information System (INIS)

    Sierralta C, Paulina; Jofre M, M. Josefina; Gonzalez E, Patricio; Massardo V, Teresa; Humeres A, Pamela; Canessa G, Jose

    2003-01-01

    A patient with a solitary pulmonary nodule is presented. She was studied with PET using F-18 FDG. The metabolic images demonstrated increased uptake in the nodule and 2 additional areas suggestive of extension, not seen in anatomic diagnostic procedures. These findings were compatible with a malignant tumour with metastasis (au)

  7. 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

  8. 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)

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

    International Nuclear Information System (INIS)

    DeLisi, L.E.; Buchsbaum, M.S.; Holcomb, H.H.

    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

  10. FIRST: Fast Iterative Reconstruction Software for (PET) tomography

    International Nuclear Information System (INIS)

    Herraiz, J L; Espana, S; Vaquero, J J; Desco, M; UdIas, J M

    2006-01-01

    Small animal PET scanners require high spatial resolution and good sensitivity. To reconstruct high-resolution images in 3D-PET, iterative methods, such as OSEM, are superior to analytical reconstruction algorithms, although their high computational cost is still a serious drawback. The higher performance of modern computers could make iterative image reconstruction fast enough to be viable, provided we are able to deal with the large number of probability coefficients for the system response matrix in high-resolution PET scanners, which is a difficult task that prevents the algorithms from reaching peak computing performance. Considering all possible axial and in-plane symmetries, as well as certain quasi-symmetries, we have been able to reduce the memory requirements to store the system response matrix (SRM) well below 1 GB, which allows us to keep the whole response matrix of the system inside RAM of ordinary industry-standard computers, so that the reconstruction algorithm can achieve near peak performance. The elements of the SRM are stored as cubic spline profiles and matched to voxel size during reconstruction. In this way, the advantages of 'on-the-fly' calculation and of fully stored SRM are combined. The on-the-fly part of the calculation (matching the profile functions to voxel size) of the SRM accounts for 10-30% of the reconstruction time, depending on the number of voxels chosen. We tested our approach with real data from a commercial small animal PET scanner. The results (image quality and reconstruction time) show that the proposed technique is a feasible solution

  11. FIRST: Fast Iterative Reconstruction Software for (PET) tomography

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J L [Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Espana, S [Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Vaquero, J J [Unidad de Medicina y CirugIa Experimental, Hospital GU Gregorio Maranon, Madrid (Spain); Desco, M [Unidad de Medicina y CirugIa Experimental, Hospital GU Gregorio Maranon, Madrid (Spain); UdIas, J M [Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain)

    2006-09-21

    Small animal PET scanners require high spatial resolution and good sensitivity. To reconstruct high-resolution images in 3D-PET, iterative methods, such as OSEM, are superior to analytical reconstruction algorithms, although their high computational cost is still a serious drawback. The higher performance of modern computers could make iterative image reconstruction fast enough to be viable, provided we are able to deal with the large number of probability coefficients for the system response matrix in high-resolution PET scanners, which is a difficult task that prevents the algorithms from reaching peak computing performance. Considering all possible axial and in-plane symmetries, as well as certain quasi-symmetries, we have been able to reduce the memory requirements to store the system response matrix (SRM) well below 1 GB, which allows us to keep the whole response matrix of the system inside RAM of ordinary industry-standard computers, so that the reconstruction algorithm can achieve near peak performance. The elements of the SRM are stored as cubic spline profiles and matched to voxel size during reconstruction. In this way, the advantages of 'on-the-fly' calculation and of fully stored SRM are combined. The on-the-fly part of the calculation (matching the profile functions to voxel size) of the SRM accounts for 10-30% of the reconstruction time, depending on the number of voxels chosen. We tested our approach with real data from a commercial small animal PET scanner. The results (image quality and reconstruction time) show that the proposed technique is a feasible solution.

  12. Positron Emission Tomography (PET): Towards Time of Flight

    International Nuclear Information System (INIS)

    Karp, Joel

    2004-01-01

    PET is a powerful imaging tool that is being used to study cancer, using a variety of tracers to measure physiological processes including glucose metabolism, cell proliferation, and hypoxia in tumor cells. As the utilization of PET has grown in the last several years, it has become clear that improved lesion detection and quantification are critical goals for cancer studies. Although physical performance of the current generation of PET scanners has improved recently, there are limitations especially for heavy patients where attenuation and scatter effects are increased. We are investigating new scintillation detectors, scanner designs, and image processing algorithms in order to overcome these limitations and improve performance. In particular, we are studying scanner designs that would incorporate scintillators with improved energy and timing resolution. Improved energy resolution helps to reduce scattered radiation, and improved timing resolution makes it feasible to incorporate the time-of-flight information between the two coincident gamma rays into the image reconstruction algorithm, a technique that improves signal-to-noise. Results of recent experiments and computer simulations will be shown to demonstrate these potential improvements.

  13. 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....

  14. Prospective evaluation of fluorodeoxyglucose positron emission tomography/computed tomography scan (FDG-PET/CT) for axillary staging in breast cancer

    International Nuclear Information System (INIS)

    Yamaguchi, Masahide; Noguchi, Akinori; Tani, Naoki

    2008-01-01

    Seventy-two patients from 2005 October to 2007 February with operative breast cancer underwent fluorodeoxyglucose positron emission tomography/computed tomography scan (FDG-PET/CT) of chest and body, ultrasound scan (US) and enhanced computed tomography scan (CT) followed by sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND). The results of PET/CT were compared with histopathological diagnosis of SLNB and ALND. Sensitivity, specificity and accuracy of PET/CT for detection of axillary lymph node metastases were 61%, 96% and 88%, respectively. Seven false-negative and two false-positive of PET/CT results were found. In patients with false-negative of PET/CT results there are two skin-invasive breast cancer patients and axillary lymph node metastases were detected in three patients with US, in one with CT and in four with SLNB. In clinical method for diagnosis of axillary lymph node metastases SLNB should be recommended because sensitivity of PET/CT for early breast cancer patients were low and positive diagnosis of axillary lymph node metastases with PET needs more than 1 cm size of lesion. PET/CT is useful for not-early breast cancer patients. To decide the operation of axillary lymph node disection needs total diagnosis of US, CT, SLNB and clinical findings. (author)

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

    International Nuclear Information System (INIS)

    Campisi, Roxana; Aramayo, Natalia; Osorio, Amilcar

    2010-01-01

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

  16. [18F]fluorodeoxyglucose PET/computed tomography in breast cancer and gynecologic cancers

    DEFF Research Database (Denmark)

    Hildebrandt, Malene Grubbe; Kodahl, Annette Raskov; Teilmann-Jørgensen, Dorte

    2015-01-01

    In this literature review, an update is provided on the role of [(18)F]fluorodeoxyglucose PET/computed tomography in different clinical settings of the 4 most frequent female-specific cancer types: breast, endometrial, ovarian, and cervical cancer. The most recent knowledge regarding primary...... diagnosis, staging, response evaluation, prognostic and predictive values, recurrence detection, and radiotherapy planning is evaluated, including, when clinically relevant, considerations with respect to the epidemiology, treatment, and course of the diseases....

  17. PET and Single-Photon Emission Computed Tomography in Brain Concussion.

    Science.gov (United States)

    Raji, Cyrus A; Henderson, Theodore A

    2018-02-01

    This article offers an overview of the application of PET and single photon emission computed tomography brain imaging to concussion, a type of mild traumatic brain injury and traumatic brain injury, in general. The article reviews the application of these neuronuclear imaging modalities in cross-sectional and longitudinal studies. Additionally, this article frames the current literature with an overview of the basic physics and radiation exposure risks of each modality. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. The clinical usefulness of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in follow-up of curatively resected pancreatic cancer patients.

    Science.gov (United States)

    Jung, Woohyun; Jang, Jin-Young; Kang, Mee Joo; Chang, Ye Rim; Shin, Yong Chan; Chang, Jihoon; Kim, Sun-Whe

    2016-01-01

    Computed tomography and serum tumor markers have limited value in detecting recurrence after curative surgery of pancreatic cancer. This study evaluated the clinical utility of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in diagnosing recurrence. One hundred ten patients underwent curative resection of pancreatic cancer were enrolled. The diagnostic value of abdominal computed tomography (CT), PET-CT and serum carbohydrate antigen (CA) 19-9 concentration were compared. The prognostic value of SUVmax on PET-CT was evaluated. PET-CT showed relatively higher sensitivity (84.5% vs. 75.0%) and accuracy (84.5% vs. 74.5%) than CT, whereas PET-CT plus CT showed greater sensitivity (97.6%) and accuracy (90.0%) than either alone. In detecting distant recurrences, PET-CT showed higher sensitivity (83.1% vs. 67.7%) than CT. Nineteen patients showed recurrences only on PET-CT, with eleven having invisible or suspected benign lesions on CT, and eight had recurrences in areas not covered by CT. SUVmax over 3.3 was predictive of poor survival after recurrence. PET-CT in combination with CT improves the detection of recurrence. PET-CT was especially advantageous in detecting recurrences in areas not covered by CT. If active post-operative surveillance after curative resection of pancreatic cancer is deemed beneficial, then it should include PET-CT combined with CT. Copyright © 2015 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

  19. 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...

  20. Positron emission tomography (PET) and pancreatic tumours; Tomographie par emission de positons (TEP) et tumeurs pancreatiques

    Energy Technology Data Exchange (ETDEWEB)

    Montravers, F.; Kerrou, K.; Grahek, D.; Gutman, F.; Beco, V. de; Talbot, J.N. [Hopital Tenon, Service de Medecine, 75 - Paris (France)

    2005-07-15

    Neoplasms of the pancreas may originate front both exocrine and endocrine cells but in 90% of the cases, they correspond to ductal adenocarcinomas. For adenocarcinomas, the major indication of FDG-PET corresponds to the pre-operative staging because unexpected distant metastases can be detected by FDG-PET in about 20 to 40% of the cases, which results in avoidance of unnecessary surgical procedures. FDG PET is also useful in evaluation of the treatment effect, monitoring after the operation and detection of recurrent pancreatic cancers. For the characterisation of the pancreatic tumour, the performance of FDG-PET is sometimes limited due to poor cellularity, hyperglycemia or inflammatory processes. especially for large tumours and is indicated only in cases of doubtful results of CT or MRI. For endocrine pancreatic tumours, FDG-PET is useful only in case of poorly-differentiated and aggressive tumours. F-DOPA PET can he useful, complementary to pentetreotide scintigraphy, in well-differentiated endocrine tumours. (authors)

  1. Somatostatin receptor positron emission tomography/computed tomography (PET/CT) in the evaluation of opsoclonus-myoclonus ataxia syndrome

    International Nuclear Information System (INIS)

    Joshi, Prathamesh; Lele, Vikram

    2013-01-01

    Opsoclonus-myoclonus ataxia (OMA) syndrome is the most common paraneoplastic neurological syndrome of childhood, associated with occult neuroblastoma in 20%-50% of all cases. OMA is the initial presentation of neuroblastoma in 1%-3% of children. Conventional radiological imaging approaches include chest radiography and abdominal computed tomography (CT). Nuclear medicine techniques, in form of 123 I/ 131 I-metaiodobenzylguanidine (MIBG) scintigraphy have been incorporated in various diagnostic algorithms for evaluation of OMA. We describe use of somatostatin receptor PET/CT with 68 Gallium- DOTA-DPhe 1 , Tyr 3 -octreotate (DOTATATE) in diagnosis of neuroblastoma in two cases of OMA

  2. Somatostatin receptor positron emission tomography/computed tomography (PET/CT) in the evaluation of opsoclonus-myoclonus ataxia syndrome.

    Science.gov (United States)

    Joshi, Prathamesh; Lele, Vikram

    2013-04-01

    Opsoclonus-myoclonus ataxia (OMA) syndrome is the most common paraneoplastic neurological syndrome of childhood, associated with occult neuroblastoma in 20%-50% of all cases. OMA is the initial presentation of neuroblastoma in 1%-3% of children. Conventional radiological imaging approaches include chest radiography and abdominal computed tomography (CT). Nuclear medicine techniques, in form of (123)I/(131)I-metaiodobenzylguanidine (MIBG) scintigraphy have been incorporated in various diagnostic algorithms for evaluation of OMA. We describe use of somatostatin receptor PET/CT with (68)Gallium- DOTA-DPhe(1), Tyr(3)-octreotate (DOTATATE) in diagnosis of neuroblastoma in two cases of OMA.

  3. Non-oncological positron emission tomography (PET): brain imaging; La tomographie par emission de positons (TEP) hors oncologie: l'exploration du cerveau

    Energy Technology Data Exchange (ETDEWEB)

    Lomena, F. [Centro de Diagnostico por la imagen (CDIC), Hospital Clinic, Servicio de medicina nuclear, Barcelona (Spain)

    2008-10-15

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

  4. Radiation shielding and health physics instrumentation for PET medical cyclotrons

    International Nuclear Information System (INIS)

    Mukherjee, B.

    2002-01-01

    Full text: Modern Medical Cyclotrons produce a variety of short-lived positron emitting PET radioisotopes, and as a result are the source of intense neutron and gamma radiations. Since such cyclotrons are housed within hospitals or medical clinics, there is significant potential for un-intentional exposure to staff or patients in proximity to cyclotron facilities. Consequently, the radiological hazards associated with Cyclotrons provide the impetus for an effective radiological shielding and continuous monitoring of various radiation levels in the cyclotron environment. Management of radiological hazards is of paramount importance for the safe operation of a Medical Cyclotron facility. This work summarised the methods of shielding calculations for a compact hospital based Medical Cyclotron currently operating in Canada, USA and Australia. The design principle and operational history of a real-time health physics monitoring system (Watchdog) operating at a large multi-energy Medical Cyclotron is also highlighted

  5. [Indications and instructions to patients for a positron emission tomography-PET scan. The importance of the hybridic PET/CT-computerised tomography scan and which specialty should be responsible for its function].

    Science.gov (United States)

    Grammaticos, Philip; Datseris, Ioannis; Gerali, Sofia; Papantoniou, Vassilios; Valsamaki, Pipitsa; Boundas, Dimitrios

    2007-01-01

    Indications and instructions to patients for performing a positron emission tomography - PET scan are mentioned. Although PET camera was developed in 1970 its clinical indications were established in about 1998. The hybridic PET/CT- computerized tomography scanner appeared in 2001 and its clinical indications are still under discussion. These discussions refer to both the use of PET/CT as an acquisition correction and anatomic localization device for PET images (AC/A) and to its use as a diagnostic CT scan (dCT). Most of the patients submitted for a PET scan have already done a dCT scan. This was the case in 286 out of the first 300 patients referred to "Evangelismos" hospital in Athens for a PET scan. These two scans can be matched electronically. Extra cost, space, personnel and radiation absorption dose especially in children, are additional factors to be considered in using the PET/CT scanner. The specialty of Nuclear Medicine is now based on the PET camera, its best part and main equipment for molecular imaging. It is very much easier and faster for a Nuclear Medicine physician who routinely reports tomographic PET and SPET images, to be familiar with the CT images than for a Radiologist to get to "know how" about the PET camera and the whole Nuclear Medicine Department. Nuclear Medicine is about open radiation sources, molecular imaging, specific radio-pharmacology, radiobiology, radiation protection etc, while on the other hand in some countries, Nuclear Physicians have already spent, as part of their official training, six months in a Radiology Department whose function is considered to be at least 25% about the CT scanner. We come to the conclusion that the PET/CT scanner should be under the responsibility of the Nuclear Medicine Department and the Radiologist should act as an advisor.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-15

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

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

    International Nuclear Information System (INIS)

    Luster, Markus; Zeich, Katrin; Glatting, Gerhard; Buck, Andreas K.; Solbach, Christoph; Reske, Sven N.; Karges, Wolfram; Pauls, Sandra; Verburg, Frederik A.; Dralle, Henning; Neumaier, Bernd; Mottaghy, Felix M.

    2010-01-01

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

  8. Positron emission tomography of the heart

    International Nuclear Information System (INIS)

    Budinger, T.F.; Yano, Y.; Mathis, C.A.; Moyer, B.R.; Huesman, R.H.; Derenzo, S.E.

    1983-01-01

    Positron emission tomography (PET) offers the opportunity to noninvasively measure heart muscle blood perfusion, oxygen utilization, metabolism of fatty acids, sugars and amino acids. This paper reviews physiological principles which are basic to PET instrumentation for imaging the heart and gives examples of the application of positron emission tomography for measuring myocardial flow and metabolism. 33 references, 11 figures, 1 table

  9. Positron emission tomography/computed tomography (PET/CT) in children.

    Science.gov (United States)

    Shore, Richard M

    2008-06-01

    Although PET imaging has been available for more than two decades, its use has greatly increased lately due to the advent of PET/CT, readily available sources of commercially supplied FDG, and mobile scanners. These features have enabled PET scanning to expand beyond select major university medical centers, with on-site cyclotron facilities to smaller institutions including free- standing children's hospitals. In these settings, imaging is generally limited to FDG, which suffices for most applications, with the majority of studies performed for tumor imaging. FDGI is being used for evaluation of many tumors in children, with its use in lymphoma being the most established. In lymphoma, it has proven quite useful in determining whether active tumor is present in residual masses following treatment, which may otherwise contain only residual fibrous tissue. For brain tumors, FDGI has some relation to tumor grade, although its more important role is distinguishing recurrent or residual tumor from the effects of treatment, particularly radiation necrosis. For neurological evaluation, interictal FDGI is helpful in localizing potential seizure foci for subsequent subdural EEG monitoring. Because of the relatively long uptake time of FDG, true ictal studies cannot be performed with FDG, and these remain within the domain of SPECT imaging of tracers such as Tc-99m HMPAO. Examinations utilizing radiopharmaceuticals other than FDG are significantly more limited in their availability and are limited to PET centers with on-site cyclotrons. However, these additional agents open the door to many additional studies, including more specific tumor-imaging agents of certain tumors such as neuroblastoma. Another neurotransmitter, F-18-fluoro-L-dopa, is of benefit outside of the central nervous system for evaluating infantile hyperinsulism. The use of PET/CT in children is increasing quickly, particularly FDGI imaging of tumors. It is expected that over the next few years, its role will

  10. 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

  11. [(18) F]fluoromethylcholine (FCH) positron emission tomography/computed tomography (PET/CT) for lymph node staging of prostate cancer

    DEFF Research Database (Denmark)

    Poulsen, Mads H; Bouchelouche, Kirsten; Høilund-Carlsen, Poul F

    2012-01-01

    recurrence. Therefore, one may question whether surgical lymph node dissection (LND) is sufficiently reliable for staging of these patients. Several imaging methods for primary LN staging of patients with prostate cancer have been tested. Acceptable detection rates have not been achieved by CT or MRI...... this procedure. However, we did detect several bone metastases with [(18) F]FCH PET/CT that the normal bone scans had missed, and this might be worth pursuing. OBJECTIVES: •  To assess the value of [(18) F]fluoromethylcholine (FCH) positron emission tomography/computed tomography (PET/CT) for lymph node (LN...

  12. [18F]Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/Computed Tomography (CT) in Suspected Recurrent Breast Cancer

    DEFF Research Database (Denmark)

    Hildebrandt, Malene Grubbe; Gerke, Oke; Baun, Christina

    2016-01-01

    PURPOSE: To prospectively investigate the diagnostic accuracy of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) with dual-time-point imaging, contrast-enhanced CT (ceCT), and bone scintigraphy (BS) in patients with suspected breast cancer recurrence....... PATIENTS AND METHODS: One hundred women with suspected recurrence of breast cancer underwent 1-hour and 3-hour FDG-PET/CT, ceCT, and BS within approximately 10 days. The study was powered to estimate the precision of the individual imaging tests. Images were visually interpreted using a four...

  13. Positron emission tomography/computed tomography (PET/CT) and CT for N staging of non-small cell lung cancer.

    Science.gov (United States)

    Vegar Zubović, Sandra; Kristić, Spomenka; Hadžihasanović, Besima

    2017-08-01

    Aim The aim of this study is to investigate the possibilities of non-invasive diagnostic imaging methods, positron emission tomography/computed tomography (PET/CT) and CT, in clinical N staging of non-small cell lung cancer (NSCLC). Methods Retrospective clinical study included 50 patients with diagnosed NSCLC who have undergone PET/CT for the purpose of disease staging. The International association for the study of lung cancer (IASLC) nodal mapping system was used for analysis of nodal disease. Data regarding CT N-staging and PET/CT Nstaging were recorded. Two methods were compared using χ2 test and Spearman rank correlation coefficient. Results Statistical analysis showed that although there were some differences in determining the N stage between CT and PET/CT, these methods were in significant correlation. CT and PET/CT findings established the same N stage in 74% of the patients. In five patients based on PET/CT findings the staging was changed from operable to inoperable, while in four patients staging was changed from inoperable to operable. Conclusion PET/CT and CT are noninvasive methods that can be reliably used for N staging of NSCLC. Copyright© by the Medical Assotiation of Zenica-Doboj Canton.

  14. Ambient radiation levels in positron emission tomography/computed tomography (PET/CT) imaging center

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Priscila do Carmo; Oliveira, Paulo Marcio Campos de; Mamede, Marcelo; Silveira, Mariana de Castro; Aguiar, Polyanna; Real, Raphaela Vila, E-mail: pridili@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Silva, Teogenes Augusto da [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-01-15

    Objective: to evaluate the level of ambient radiation in a PET/CT center. Materials and methods: previously selected and calibrated TLD-100H thermoluminescent dosimeters were utilized to measure room radiation levels. During 32 days, the detectors were placed in several strategically selected points inside the PET/CT center and in adjacent buildings. After the exposure period the dosimeters were collected and processed to determine the radiation level. Results: in none of the points selected for measurements the values exceeded the radiation dose threshold for controlled area (5 mSv/ year) or free area (0.5 mSv/year) as recommended by the Brazilian regulations. Conclusion: in the present study the authors demonstrated that the whole shielding system is appropriate and, consequently, the workers are exposed to doses below the threshold established by Brazilian standards, provided the radiation protection standards are followed. (author)

  15. Ambient radiation levels in positron emission tomography/computed tomography (PET/CT) imaging center

    Science.gov (United States)

    Santana, Priscila do Carmo; de Oliveira, Paulo Marcio Campos; Mamede, Marcelo; Silveira, Mariana de Castro; Aguiar, Polyanna; Real, Raphaela Vila; da Silva, Teógenes Augusto

    2015-01-01

    Objective To evaluate the level of ambient radiation in a PET/CT center. Materials and Methods Previously selected and calibrated TLD-100H thermoluminescent dosimeters were utilized to measure room radiation levels. During 32 days, the detectors were placed in several strategically selected points inside the PET/CT center and in adjacent buildings. After the exposure period the dosimeters were collected and processed to determine the radiation level. Results In none of the points selected for measurements the values exceeded the radiation dose threshold for controlled area (5 mSv/year) or free area (0.5 mSv/year) as recommended by the Brazilian regulations. Conclusion In the present study the authors demonstrated that the whole shielding system is appropriate and, consequently, the workers are exposed to doses below the threshold established by Brazilian standards, provided the radiation protection standards are followed. PMID:25798004

  16. Detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography (FDG-PET/CT)

    International Nuclear Information System (INIS)

    Hirakawa, Tomoko; Okumura, Yoshihiro; Kato, Jun

    2012-01-01

    The purpose of this study was to analyze the detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT). Data for a total of 492 patients who had undergone both PET/CT and colonoscopy were analyzed. After the findings of PET/CT and colonoscopy were determined independently, the results were compared in each of the six colonic sites examined in all patients. The efficacy of PET/CT was determined using colonoscopic examination as the gold standard. In all, 270 colorectal lesions 5 mm or more in size, including 70 pathologically confirmed malignant lesions, were found in 172 patients by colonoscopy. The sensitivity and specificity of PET/CT for detecting any of the colorectal lesions were 36 and 98%, respectively. For detecting lesions 11 mm or larger, the sensitivity was increased to 85%, with the specificity remaining consistent (97%). Moreover, the sensitivity for tumors 21 mm or larger was 96% (48/50). Tumors with malignant or high-grade pathology were likely to be positive with PET/CT. A size of 10 mm or smaller [odds ratio (OR) 44.14, 95% confidence interval (95% CI) 11.44-221.67] and flat morphology (OR 7.78, 95% CI 1.79-36.25) were significant factors that were associated with false-negative cases on PET/CT. The sensitivity of PET/CT for detecting colorectal lesions is acceptable, showing size- and pathology-dependence, suggesting, for the most part, that clinically relevant lesions are detectable with PET/CT. However, when considering PET/CT for screening purposes caution must be exercised because there are cases of false-negative results. (author)

  17. Development of computed tomography instrument for college teaching

    International Nuclear Information System (INIS)

    Liu Fenglin; Lu Yanping; Wang Jue

    2006-01-01

    Computed tomography (CT), which uses penetrating radiation from many directions to reconstruct cross-sectional or 3D images of object, has widely applied in medical diagnosis and treatment, industrial NDT and NDE. So it is significant for college students to understand the fundamental of CT. The authors describe the CD-50BG CT instrument developed for experimental teaching at colleges. With 50 mm field-of-view and the translation-rotation scanning mode, the system makes use of a single plastic scintillator + photomultiplier detector and a 137 Cs radioactive source with 0.74 GBq activity, which is housed in a tungsten alloy shield. At the same time, an image processing software has been developed to process the acquired data, so that cross-sectional and 3D images can be reconstructed. High quality images with 1 lp·mm -1 spatial resolution and 1% contrast sensitivity are obtained. So far in China, more than ten institutions including Tsinghua University and Peking University have already applied the system to elementary teaching. (authors)

  18. FDG-PET in the diagnosis of neuropsychiatric Lupus erythematosus and comparison with computed tomography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Stoppe, G.; Wildhagen, K.; Meyer, G.J.; Schober, O.

    1989-01-01

    Central nervous system involvement has been found in 30-75% of all cases of systemic lupus erythematosus (SLE). Up to now, clinical diagnosis is difficult and there are no markers for disease activity. We have compared cranial computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) using fluorodesoxyglucose (FDG) in two cases. FDG-PET is shown to be the most sensitive method demonstrating even reversible deficits and a better correlation with other neurological findings. MRI seems to be more sensitive than CT. A survey of the literature concerning imaging methods in neuropsychiatric SLE is given. The special problem of neuronal desactivation by antineuronal activity is discussed. (orig.) [de

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

    International Nuclear Information System (INIS)

    Grabowska, A.; Krolicki, L.

    1997-01-01

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

  20. Performance and limitations of positron emission tomography (PET) scanners for imaging very low activity sources.

    Science.gov (United States)

    Freedenberg, Melissa I; Badawi, Ramsey D; Tarantal, Alice F; Cherry, Simon R

    2014-02-01

    Emerging applications for positron emission tomography (PET) may require the ability to image very low activity source distributions in the body. The performance of clinical PET scanners in the regime where activity in the field of view is source in the NEMA scatter phantom), the BGO-based scanner significantly outperformed the LSO-based scanner. This was largely due to the effect of background counts emanating from naturally occurring but radioactive (176)Lu within the LSO detector material, which dominates the observed counting rate at the lowest activities. Increasing the lower energy threshold from 350 keV to 425 keV in an attempt to reduce this background did not significantly improve the measured NECR performance. The measured singles rate due to (176)Lu emissions within the scanner energy window was also found to be dependent on temperature, and to be affected by the operation of the CT component, making approaches to correct or compensate for the background more challenging. We conclude that for PET studies in a very low activity range, BGO-based scanners are likely to have better performance because of the lack of significant background. Copyright © 2013 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  1. 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.

  2. PET/CT (and CT) instrumentation, image reconstruction and data transfer for radiotherapy planning

    International Nuclear Information System (INIS)

    Sattler, Bernhard; Lee, John A.; Lonsdale, Markus; Coche, Emmanuel

    2010-01-01

    The positron emission tomography in combination with CT in hybrid, cross-modality imaging systems (PET/CT) gains more and more importance as a part of the treatment-planning procedure in radiotherapy. Positron emission tomography (PET), as a integral part of nuclear medicine imaging and non-invasive imaging technique, offers the visualization and quantification of pre-selected tracer metabolism. In combination with the structural information from CT, this molecular imaging technique has great potential to support and improve the outcome of the treatment-planning procedure prior to radiotherapy. By the choice of the PET-Tracer, a variety of different metabolic processes can be visualized. First and foremost, this is the glucose metabolism of a tissue as well as for instance hypoxia or cell proliferation. This paper comprises the system characteristics of hybrid PET/CT systems. Acquisition and processing protocols are described in general and modifications to cope with the special needs in radiooncology. This starts with the different position of the patient on a special table top, continues with the use of the same fixation material as used for positioning of the patient in radiooncology while simulation and irradiation and leads to special processing protocols that include the delineation of the volumes that are subject to treatment planning and irradiation (PTV, GTV, CTV, etc.). General CT acquisition and processing parameters as well as the use of contrast enhancement of the CT are described. The possible risks and pitfalls the investigator could face during the hybrid-imaging procedure are explained and listed. The interdisciplinary use of different imaging modalities implies a increase of the volume of data created. These data need to be stored and communicated fast, safe and correct. Therefore, the DICOM-Standard provides objects and classes for this purpose (DICOM RT). Furthermore, the standard DICOM objects and classes for nuclear medicine (NM, PT) and

  3. A combined positron emission tomography (PET)-electron paramagnetic resonance imaging (EPRI) system: initial evaluation of a prototype scanner

    Science.gov (United States)

    Tseytlin, Mark; Stolin, Alexander V.; Guggilapu, Priyaankadevi; Bobko, Andrey A.; Khramtsov, Valery V.; Tseytlin, Oxana; Raylman, Raymond R.

    2018-05-01

    The advent of hybrid scanners, combining complementary modalities, has revolutionized the application of advanced imaging technology to clinical practice and biomedical research. In this project, we investigated the melding of two complementary, functional imaging methods: positron emission tomography (PET) and electron paramagnetic resonance imaging (EPRI). PET radiotracers can provide important information about cellular parameters, such as glucose metabolism. While EPR probes can provide assessment of tissue microenvironment, measuring oxygenation and pH, for example. Therefore, a combined PET/EPRI scanner promises to provide new insights not attainable with current imagers by simultaneous acquisition of multiple components of tissue microenvironments. To explore the simultaneous acquisition of PET and EPR images, a prototype system was created by combining two existing scanners. Specifically, a silicon photomultiplier (SiPM)-based PET scanner ring designed as a portable scanner was combined with an EPRI scanner designed for the imaging of small animals. The ability of the system to obtain simultaneous images was assessed with a small phantom consisting of four cylinders containing both a PET tracer and EPR spin probe. The resulting images demonstrated the ability to obtain contemporaneous PET and EPR images without cross-modality interference. Given the promising results from this initial investigation, the next step in this project is the construction of the next generation pre-clinical PET/EPRI scanner for multi-parametric assessment of physiologically-important parameters of tissue microenvironments.

  4. 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

  5. The willingness to pay for positron emission tomography (PET). Evaluation of suspected lung cancer using contingent valuation

    International Nuclear Information System (INIS)

    Papatheofanis, F.J.

    2000-01-01

    In this study, contingent valuation is used to estimate the willingness-to-pay (WTP) for positron emission tomography (PET) imaging by patients with suspected benign or malignant lung disease. Patients (n=87) undergoing thoracic computed tomography were surveyed for their WTP for PET for the evaluation of lung disease in lieu of further testing. Patients were provided background PET information and a two-page self-administered questionnaire. The survey queried basic demographic information, perceived risk of malignancy, and perceived life expectancy given a diagnosis of malignancy. Patients with increased perception of risk were willing to pay more than those with lower perceived risk. Patients who were self-payers for their health insurance indicated a lower WTP than those who did not pay any out-of-pocket insurance premiums. Individuals are willing to pay additional out-of-pocket costs for diagnostic imaging to reduce their perception of risk and improve their quality of life

  6. PET-Studies in parkinson's disease; Untersuchungen mit der Positronen-Emissions-Tomographie (PET) bei Patienten mit Morbus Parkinson

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, J. [Klinik fuer Neurologie, Univ. Leipzig (Germany)

    2002-09-01

    Positron-emission-tomography (PET) has enabled to study the metabolism and blood flow in specific brain areas. Besides, there is a variety of radiotracers that allow quantification of the function of distinct molecules. In respect to Parkinson's disease, PET allowed for the first time to assess the number of dopaminergic neurons in vivo. Thus, helping confirming a dopaminergic deficit, measuring disease progression and also help to determine the function of dopaminergic grafts. Current research has shifted to determine the role of related neurotransmitter systems in the pathophysiology of Parkinson's disease. (orig.) [German] Die positronen-emissions-tomographie (PET) bietet neben der Messung von Metabolismus und Blutfluss die Moeglichkeit der Darstellung von einzelnen Molekuelen. Bei Patienten mit Morbus Parkinson hat es diese Technik erstmals erlaubt, die Anzahl der dopaminergen Neurone zu quantifizieren, wodurch die Diagnose gesichert, die Progression der Erkrankung beurteilt und auch das Anwachsen von Implantaten beurteilt werden kann. Die PET hat einen wesentlichen Beitrag zu unserem heutigen Wissen ueber die Pathophysiologie dieser Erkrankung beigetragen. (orig.)

  7. Gamma camera based FDG PET in oncology

    International Nuclear Information System (INIS)

    Park, C. H.

    2002-01-01

    Positron Emission Tomography(PET) was introduced as a research tool in the 1970s and it took about 20 years before PET became an useful clinical imaging modality. In the USA, insurance coverage for PET procedures in the 1990s was the turning point, I believe, for this progress. Initially PET was used in neurology but recently more than 80% of PET procedures are in oncological applications. I firmly believe, in the 21st century, one can not manage cancer patients properly without PET and PET is very important medical imaging modality in basic and clinical sciences. PET is grouped into 2 categories; conventional (c) and gamma camera based ( CB ) PET. CB PET is more readily available utilizing dual-head gamma cameras and commercially available FDG to many medical centers at low cost to patients. In fact there are more CB PET in operation than cPET in the USA. CB PET is inferior to cPET in its performance but clinical studies in oncology is feasible without expensive infrastructures such as staffing, rooms and equipments. At Ajou university Hospital, CBPET was installed in late 1997 for the first time in Korea as well as in Asia and the system has been used successfully and effectively in oncological applications. Our was the fourth PET operation in Korea and I believe this may have been instrumental for other institutions got interested in clinical PET. The following is a brief description of our clinical experience of FDG CBPET in oncology

  8. PET/MRI. Challenges, solutions and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Herzog, Hans [Forschungszentrum Juelich (Germany). Inst. of Neuroscience and Medicine - 4

    2012-07-01

    Already from the start of PET/CT integrating positron emission tomography (PET) and computed tomography (CT) in one instrument, there have been considerations how to combine PET and magnetic resonance imaging (MRI) so that their complementary abilities can be utilized in a single investigation. Since classical PET electronics fail in an even weak magnetic field and PET signal processing might disturb high-frequency signals of MRI, it soon became clear that new solutions had to be found to avoid mutual interferences. During the last fifteen years a number of different approaches towards PET/MRI for small animal imaging have been developed by research groups which together with their specific features are summarized in this review. Recently, PET/MRI for human imaging became available as well - this time by industrial initiatives. First some prototypes of BrainPET/MRI were developed followed by commercial products for simultaneous and non-simultaneous whole-body PET/MRI. Although only PET/MRI integrated in one scanner offers the full diversity of complementary multiparametric imaging, there are also promising applications of non-simultaneous sequential PET/MRI. While describing the present instrumentation for human PET/MRI, this review discusses the challenges and promises related to this new imaging technology. (orig.)

  9. New developments in molecular imaging: positron emission tomography time-of-flight (TOF-PET); Nuevos desarrollos en imagen molecular: Tomografia por Emision de Positrones con Teimpo de Vuelo (TOF-PET)

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, P.; Couce, B.; Iglesias, A.; Lois, C.

    2011-07-01

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

  10. Para neoplastic syndromes: Usefulness of 18F-fluoro-deoxy-glucose (F.D.G.) positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Banayan, S.; Janier, M.; Guillerma-Zucchi, N.; Billotey, C.; Ninet, J.; Delmas, P.; Thivolet, C.; Pellet, O.

    2008-01-01

    Background We evaluated the performance of 18 F-fluorodeoxyglucose ( 18 F.D.G.) positron emission tomography (PET) in the diagnosis of underlying malignancy in cases of suspected para neoplastic syndrome (P.S.). Methods 18 F.D.G.-PET was performed in 31 patients, clinically suspected to have P.S.. The P.S. were 34, among which 12 neurological diseases, eight endocrine, seven rheumatological, one dermatological and six vascular. We compared computed tomography (CT), iodine-enhanced most of the time, and 18 F.D.G.-PET reports to clinicians definitive conclusion at the end of the work-up and a follow-up period of, at least, two months. Results We obtained a histological diagnosis of cancer for ten patients, but could only identify the primary site of malignancy for nine of them. 18 F.D.G.-PET showed six primary sites among which three were not seen on CT. CT disclosed four primary sites, among which one was not seen on 18 F.D.G.-PET. In one case, 18 F.D.G.-PET disclosed regional lymph node metastases whereas these were not identified by CT. Eleven non-neoplastic causes were evidenced, among which 18 F.D.G.-PET played a major role in three cases. Ten causes were still undetermined at the end of the study. Conclusion Whole-body 18 F.D.G.-PET study plays an important role in the identification of underlying malignancy in clinically suspected para neoplastic syndromes; either by identifying the primary tumor or by directing biopsy of metastases. Furthermore, it can identify non-neoplastic causes. (authors)

  11. A combined positron emission tomography (PET)- electron paramagnetic resonance imaging (EPRI) system: initial evaluation of a prototype scanner.

    Science.gov (United States)

    Tseytlin, Mark; Stolin, Alexander V; Guggilapu, Priyaankadevi; Bobko, Andrey A; Khramtsov, Valery V; Tseytlin, Oxana; Raylman, Raymond R

    2018-04-20

    The advent of hybrid scanners, combining complementary modalities, has revolutionized imaging; enhancing clinical practice and biomedical research. In this project, we investigated the melding of two complementary, functional imaging methods: positron emission tomography (PET) and electron paramagnetic resonance imaging (EPRI). The PET radiotracers can provide important information about cellular parameters, such as glucose metabolism. While EPR probes can provide assessment of tissue microenvironment, measuring parameters such as oxygenation and pH, for example. A combined PET/EPRI scanner has the promise to provide new insights not attainable with current imagers by simultaneous acquisition of multiple components of tissue microenvironments. In this investigation, a prototype system was created by combing two existing scanners, modified for simultaneous imaging. Specifically, a silicon photomultiplier (SiPM) based PET scanner ring designed as a portable scanner was combined with an EPRI scanner designed for the imaging of small animals. The ability of the system to obtain simultaneous images was assessed with a small phantom consisting of four cylinders containing both PET and EPR tracers. The resulting images demonstrated the ability to obtain contemporaneous PET and ERP images without cross-modality interference. The next step in this project is the construction of pre-clinical PET/EPRI scanner for multi-parametric assessment of physiologically important parameters of tissue microenvironments. . © 2018 Institute of Physics and Engineering in Medicine.

  12. Radiotherapy treatment planning for patients with non-small cell lung cancer using positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Erdi, Yusuf E.; Rosenzweig, Kenneth; Erdi, Alev K.; Macapinlac, Homer A.; Hu, Yu-Chi; Braban, Louise E.; Humm, John L.; Squire, Olivia D.; Chui, Chen-Shou; Larson, Steven M.; Yorke, Ellen D.

    2002-01-01

    Purpose: Many patients with non-small cell lung cancer (NSCLC) receive external beam radiation therapy as part of their treatment. Three-dimensional conformal radiation therapy (3DCRT) commonly uses computed tomography (CT) to accurately delineate the target lesion and normal tissues. Clinical studies, however, indicate that positron emission tomography (PET) has higher sensitivity than CT in detecting and staging of mediastinal metastases. Imaging with fluoro-2-deoxyglucose (FDG) PET in conjunction with CT, therefore, can improve the accuracy of lesion definition. In this pilot study, we investigated the potential benefits of incorporating PET data into the conventional treatment planning of NSCLC. Case-by-case, we prospectively analyzed planning target volume (PTV) and lung toxicity changes for a cohort of patients. Materials and methods: We have included 11 patients in this study. They were immobilized in the treatment position and CT simulation was performed. Following CT simulation, PET scanning was performed in the treatment position using the same body cast that was produced for CT simulation and treatment. The PTV, along with the gross target volume (GTV) and normal organs, was first delineated using the CT data set. The CT and PET transmission images were then registered in the treatment planning system using either manual or automated methods, leading to consequent registration of the CT and emission images. The PTV was then modified using the registered PET emission images. The modified PTV is seen simultaneously on both CT and PET images, allowing the physician to define the PTV utilizing the information from both data sets. Dose-volume histograms (DVHs) for lesion and normal organs were generated using both CT-based and PET+CT-based treatment plans. Results: For all patients, there was a change in PTV outline based on CT images versus CT/PET fused images. In seven out of 11 cases, we found an increase in PTV volume (average increase of 19%) to

  13. Positron Emission Tomography: Its 65 years

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  14. Positron emission tomography (PET) studies of dopaminergic/cholinergic interactions in the baboon brain

    International Nuclear Information System (INIS)

    Dewey, S.L.; Brodie, J.D.; Fowler, J.S.; MacGregor, R.R.; Schlyer, D.J.; King, P.T.; Alexoff, D.L.; Volkow, N.D.; Shiue, C.Y.; Wolf, A.P.

    1990-01-01

    Interactions between the dopaminergic D2 receptor system and the muscarinic cholinergic system in the corpus striatum of adult female baboons (Papio anubis) were examined using positron emission tomography (PET) combined with [18F]N-methylspiroperidol [( 18F]NMSP) (to probe D2 receptor availability) and [N-11C-methyl]benztropine (to probe muscarinic cholinergic receptor availability). Pretreatment with benztropine, a long-lasting anticholinergic drug, bilaterally reduced the incorporation of radioactivity in the corpus striatum but did not alter that observed in the cerebellum or the rate of metabolism of [18F]NMSP in plasma. Pretreatment with unlabelled NMSP, a potent dopaminergic antagonist, reduced the incorporation of [N-11C-methyl]benztropine in all brain regions, with the greatest effect being in the corpus striatum greater than cortex greater than thalamus greater than cerebellum, but did not alter the rate of metabolism of the labelled benztropine in the plasma. These reductions in the incorporation of either [18F]NMSP or [N-11C-methyl]benztropine exceeded the normal variation in tracer incorporation in repeated studies in the same animal. This study demonstrates that PET can be used as a tool for investigating interactions between neurochemically different yet functionally linked neurotransmitters systems in vivo and provides insight into the consequences of multiple pharmacologic administration

  15. The measurement of willingness to pay for mass cancer screening with whole-body PET (positron emission tomography)

    International Nuclear Information System (INIS)

    Yasunaga, Hideo; Ide, Hiroo; Imamura, Tomoaki; Ohe, Kazuhiko

    2006-01-01

    Recently, we have seen an increase in the number of studies that measured the willingness to pay (WTP) for medical services using the contingent valuation method (CVM) and evaluated the benefits of these services. This study aimed to measure the general public's WTP for cancer screening with positron emission tomography (PET) and to determine consumer characteristics that may affect their WTP. A questionnaire survey of males and females living in Japan aged between 40 and 59 years was conducted via the Internet. A total of 274 individuals accepted the offer to participate and were enrolled in the study. The study participants were divided into two groups: Group A (n=138) and Group B (n=136). Group A was provided only with information about the PET procedure and the high cancer detection rate; Group B was provided with additional information regarding the possibility of ''false negative'' and false positive'' results and the fact that the efficacy of PET screening for reducing mortality has not yet been demonstrated. Participants were then asked to answer their WTP for cancer screening with PET by payment cards approach. The overall average amount consumers were willing to pay for PET cancer screening was $103.7 (n=274). The average value in Group A was $107.3, the average value in Group B was $100.0 and there was no statistically significant difference between the groups. The results of categorical regression analysis showed that household annual income was the only significant factor affecting WTP. Our study showed that household annual income affected the WTP for cancer screening with PET and therefore the demand for PET screening would be limited to the high-income group. Negative information about PET did not reduce the WTP. This finding suggests that test subjects mainly evaluated the high detection rate of PET screening and the reassurance'' value of receiving negative screening results. (author)

  16. Isolated thymic Langerhans cell histiocytosis discovered on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT).

    Science.gov (United States)

    Turpin, Sophie; Carret, Anne-Sophie; Dubois, Josée; Buteau, Chantal; Patey, Natalie

    2015-11-01

    The thymic infiltration in young patients with multisystemic Langerhans cell histiocytosis and its radiologic features are well known. However, isolated thymic disease has seldom been reported in the literature. We report the case of a 10-month-old child admitted for fever of unknown origin. Whole-body F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) was performed to identify a focus of infection. It demonstrated an unusual aspect of the thymus, which led to further investigation and revealed isolated infiltration of the thymus by Langerhans cell histiocytosis. The patient was treated accordingly and is now disease free. As evaluation of Langerhans cell histiocytosis patients with F-18 FDG PET/CT is becoming more frequent, it is important to be aware of the scintigraphical characteristics of thymic Langerhans cell histiocytosis.

  17. Isolated thymic Langerhans cell histiocytosis discovered on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT)

    Energy Technology Data Exchange (ETDEWEB)

    Turpin, Sophie [CHU Sainte-Justine, Nuclear Medicine, Montreal (Canada); Carret, Anne-Sophie [CHU Sainte-Justine, Hemato-Oncology, Montreal (Canada); Dubois, Josee [CHU Sainte-Justine, Radiology, Montreal (Canada); Buteau, Chantal [CHU Sainte-Justine, Infectious Diseases, Montreal (Canada); Patey, Natalie [CHU Sainte-Justine, Pathology, Montreal (Canada)

    2015-11-15

    The thymic infiltration in young patients with multisystemic Langerhans cell histiocytosis and its radiologic features are well known. However, isolated thymic disease has seldom been reported in the literature. We report the case of a 10-month-old child admitted for fever of unknown origin. Whole-body F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) was performed to identify a focus of infection. It demonstrated an unusual aspect of the thymus, which led to further investigation and revealed isolated infiltration of the thymus by Langerhans cell histiocytosis. The patient was treated accordingly and is now disease free. As evaluation of Langerhans cell histiocytosis patients with F-18 FDG PET/CT is becoming more frequent, it is important to be aware of the scintigraphical characteristics of thymic Langerhans cell histiocytosis. (orig.)

  18. Brain fluorodeoxyglucose positron emission tomography (¹⁸FDG PET) in patients with acute thallium intoxication.

    Science.gov (United States)

    Liu, C H; Lin, K J; Wang, H M; Kuo, H C; Chuang, W L; Weng, Y H; Shih, T S; Huang, C C

    2013-03-01

    Thallium toxicity induces cellular injury through impaired Na-K-ATPase activity. The aim of this study was to investigate functional imaging and the long-term clinical-imaging correlations of thallium toxicity. We measured thallium concentrations in blood, urine, stools, and hair of a 48-year-old woman and a 52-year-old man (patients 1 and 2) in the first 3 months after exposure to thallium containing water, and studied their neuropsychological functions. Using fluorodeoxyglucose positron emission tomography ((18)FDG PET) scans, we examined the brain involvement and correlated the image findings with the clinical presentations. On the 1st, 30th, and 61st days after exposure, the thallium concentrations in patient 1 were 2056, 311, and 7.5 μg/L in the blood, and 11400, 4570, and 36.4 μg/L in the urine. The concentrations in patient 2 were 956, 235, and 15.6 μg/L in the blood, and 11900, 2670, and 101 μg/L in the urine. On the 40th, 50th and 89th days after exposure, the thallium concentration in the stools were 21.6, 3.6, and 0.35 μg/g in patient 1, and 22.2, 3.2, and 0.37 μg/g in patient 2. Executive function, perceptual motor speed, and learning memory were initially abnormal but recovered particularly within the first year. The first (18)FDG PET studies of both patients disclosed a decreased uptake of glucose metabolism in the cingulate gyrus, bilateral frontal, and parietal lobes 2-5 months after exposure. The follow-up (18)FDG PET scan of patient 2 revealed a partial recovery. This study indicates that damage to the central nervous system after acute thallium poisoning may be reversible after a long-term follow-up. Brain (18)FDG PET demonstrated the brain involvement and was correlated with cognitive impairment.

  19. {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT) Imaging in the Staging and Prognosis of Inflammatory Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Alberini, J.L.; Wartski, M.; Gontier, E.; Madar, O.; Pecking, A.P. [Nuclear Medicine Department, Cancer Research Center Rene Huguenin, Saint-Cloud (France); Lerebours, F. [Oncology Department, Cancer Research Center Rene Huguenin, Saint-Cloud (France); Fourme, E. [Biostatistics Department, Cancer Research Center Rene Huguenin, Saint-Cloud (France); Le Stanc, E. [Nuclear Medicine Department, Foch Hospital, Suresnes (France); Cherel, P. [Radiology Department, Cancer Research Center Rene Huguenin, Saint-Cloud (France); Alberini, J.L. [School of Medicine, Versailles Saint-Quentin University (France)

    2009-07-01

    Background: To prospectively assess fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) staging and prognosis value in patients with suspected inflammatory breast cancer (IBC). Methods: Sixty-two women (mean age 50.7 {+-} 11.4 years) presenting with unilateral inflammatory breast tumors (59 invasive carcinomas; 3 mastitis) underwent a PET/CT scan before biopsy. Results: PET/CT scan was positive for the primary malignant tumor in 100% and false positive in 2 of 3 benign mastitis. In 59 IBC patients, FDG nodal foci were detected in axillary (90%; n = 53) and extra-axillary areas (56%; n = 33) ipsilateral to the cancer. Compared with clinical examination, the axillary lymph node status by PET/CT was upstaged and down staged in 35 and 5 patients, respectively. In 7 of 9 N0 patients, the axillary lymph node positivity on PET/CT was correct, as revealed by pathological post surgery assessment (not available in the 2 remaining patients). The nodal foci were compared with preoperative fine needle aspiration and/or pathological post chemotherapy findings available in 44 patients and corresponded to 38 true positive, 4 false-negative, and 2 false-positive cases. In 18 of 59 IBC patients (31%), distant lesions were found. On the basis of a univariate analysis of the first enrolled patients (n = 42), among 28 patients who showed intense tumoral uptake (standard uptake value(max){>=}5), the 11 patients with distant lesions had a worse prognosis than the 17 patients without distant lesions (P =.04). Conclusions: FDG-PET/CT imaging provides additional invaluable information regarding nodal status or distant metastases in IBC patients and should be considered in the initial staging. It seems also that some prognostic information can be derived from FDG uptake characteristics. (authors)

  20. 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT) Imaging in the Staging and Prognosis of Inflammatory Breast Cancer

    International Nuclear Information System (INIS)

    Alberini, J.L.; Wartski, M.; Gontier, E.; Madar, O.; Pecking, A.P.; Lerebours, F.; Fourme, E.; Le Stanc, E.; Cherel, P.; Alberini, J.L.

    2009-01-01

    Background: To prospectively assess fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) staging and prognosis value in patients with suspected inflammatory breast cancer (IBC). Methods: Sixty-two women (mean age 50.7 ± 11.4 years) presenting with unilateral inflammatory breast tumors (59 invasive carcinomas; 3 mastitis) underwent a PET/CT scan before biopsy. Results: PET/CT scan was positive for the primary malignant tumor in 100% and false positive in 2 of 3 benign mastitis. In 59 IBC patients, FDG nodal foci were detected in axillary (90%; n = 53) and extra-axillary areas (56%; n = 33) ipsilateral to the cancer. Compared with clinical examination, the axillary lymph node status by PET/CT was upstaged and down staged in 35 and 5 patients, respectively. In 7 of 9 N0 patients, the axillary lymph node positivity on PET/CT was correct, as revealed by pathological post surgery assessment (not available in the 2 remaining patients). The nodal foci were compared with preoperative fine needle aspiration and/or pathological post chemotherapy findings available in 44 patients and corresponded to 38 true positive, 4 false-negative, and 2 false-positive cases. In 18 of 59 IBC patients (31%), distant lesions were found. On the basis of a univariate analysis of the first enrolled patients (n = 42), among 28 patients who showed intense tumoral uptake (standard uptake value(max)≥5), the 11 patients with distant lesions had a worse prognosis than the 17 patients without distant lesions (P =.04). Conclusions: FDG-PET/CT imaging provides additional invaluable information regarding nodal status or distant metastases in IBC patients and should be considered in the initial staging. It seems also that some prognostic information can be derived from FDG uptake characteristics. (authors)

  1. Radiation dose reduction through combining positron emission tomography/computed tomography (PET/CT) and diagnostic CT in children and young adults with lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Zhihua; Gates, Erica L.; Trout, Andrew T. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); O' Brien, Maureen M. [Cincinnati Children' s Hospital Medical Center, Division of Oncology, Cancer and Blood Disease Institute, Cincinnati, OH (United States)

    2018-02-15

    Both [F-18]2-fluoro-2-deoxyglucose positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) and diagnostic CT are at times required for lymphoma staging. This means some body segments are exposed twice to X-rays for generation of CT data (diagnostic CT + localization CT). To describe a combined PET/diagnostic CT approach that modulates CT tube current along the z-axis, providing diagnostic CT of some body segments and localization CT of the remaining body segments, thereby reducing patient radiation dose. We retrospectively compared total patient radiation dose between combined PET/diagnostic CT and separately acquired PET/CT and diagnostic CT exams. When available, we calculated effective doses for both approaches in the same patient; otherwise, we used data from patients of similar size. To confirm image quality, we compared image noise (Hounsfield unit [HU] standard deviation) as measured in the liver on both combined and separately acquired diagnostic CT images. We used t-tests for dose comparisons and two one-sided tests for image-quality equivalence testing. Mean total effective dose for the CT component of the combined and separately acquired diagnostic CT exams were 6.20±2.69 and 8.17±2.61 mSv, respectively (P<0.0001). Average dose savings with the combined approach was 24.8±17.8% (2.60±2.51 mSv [range: 0.32-4.72 mSv]) of total CT effective dose. Image noise was not statistically significantly different between approaches (12.2±1.8 HU vs. 11.7±1.5 HU for the combined and separately acquired diagnostic CT images, respectively). A combined PET/diagnostic CT approach as described offers dose savings at similar image quality for children and young adults with lymphoma who have indications for both PET and diagnostic CT examinations. (orig.)

  2. Radiation dose reduction through combining positron emission tomography/computed tomography (PET/CT) and diagnostic CT in children and young adults with lymphoma

    International Nuclear Information System (INIS)

    Qi, Zhihua; Gates, Erica L.; Trout, Andrew T.; O'Brien, Maureen M.

    2018-01-01

    Both [F-18]2-fluoro-2-deoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) and diagnostic CT are at times required for lymphoma staging. This means some body segments are exposed twice to X-rays for generation of CT data (diagnostic CT + localization CT). To describe a combined PET/diagnostic CT approach that modulates CT tube current along the z-axis, providing diagnostic CT of some body segments and localization CT of the remaining body segments, thereby reducing patient radiation dose. We retrospectively compared total patient radiation dose between combined PET/diagnostic CT and separately acquired PET/CT and diagnostic CT exams. When available, we calculated effective doses for both approaches in the same patient; otherwise, we used data from patients of similar size. To confirm image quality, we compared image noise (Hounsfield unit [HU] standard deviation) as measured in the liver on both combined and separately acquired diagnostic CT images. We used t-tests for dose comparisons and two one-sided tests for image-quality equivalence testing. Mean total effective dose for the CT component of the combined and separately acquired diagnostic CT exams were 6.20±2.69 and 8.17±2.61 mSv, respectively (P<0.0001). Average dose savings with the combined approach was 24.8±17.8% (2.60±2.51 mSv [range: 0.32-4.72 mSv]) of total CT effective dose. Image noise was not statistically significantly different between approaches (12.2±1.8 HU vs. 11.7±1.5 HU for the combined and separately acquired diagnostic CT images, respectively). A combined PET/diagnostic CT approach as described offers dose savings at similar image quality for children and young adults with lymphoma who have indications for both PET and diagnostic CT examinations. (orig.)

  3. Radiation dose reduction through combining positron emission tomography/computed tomography (PET/CT) and diagnostic CT in children and young adults with lymphoma.

    Science.gov (United States)

    Qi, Zhihua; Gates, Erica L; O'Brien, Maureen M; Trout, Andrew T

    2018-02-01

    Both [F-18]2-fluoro-2-deoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) and diagnostic CT are at times required for lymphoma staging. This means some body segments are exposed twice to X-rays for generation of CT data (diagnostic CT + localization CT). To describe a combined PET/diagnostic CT approach that modulates CT tube current along the z-axis, providing diagnostic CT of some body segments and localization CT of the remaining body segments, thereby reducing patient radiation dose. We retrospectively compared total patient radiation dose between combined PET/diagnostic CT and separately acquired PET/CT and diagnostic CT exams. When available, we calculated effective doses for both approaches in the same patient; otherwise, we used data from patients of similar size. To confirm image quality, we compared image noise (Hounsfield unit [HU] standard deviation) as measured in the liver on both combined and separately acquired diagnostic CT images. We used t-tests for dose comparisons and two one-sided tests for image-quality equivalence testing. Mean total effective dose for the CT component of the combined and separately acquired diagnostic CT exams were 6.20±2.69 and 8.17±2.61 mSv, respectively (PCT effective dose. Image noise was not statistically significantly different between approaches (12.2±1.8 HU vs. 11.7±1.5 HU for the combined and separately acquired diagnostic CT images, respectively). A combined PET/diagnostic CT approach as described offers dose savings at similar image quality for children and young adults with lymphoma who have indications for both PET and diagnostic CT examinations.

  4. Polarimetry noise in fiber-based optical coherence tomography instrumentation

    Science.gov (United States)

    Zhang, Ellen Ziyi; Vakoc, Benjamin J.

    2011-01-01

    High noise levels in fiber-based polarization-sensitive optical coherence tomography (PS-OCT) have broadly limited its clinical utility. In this study we investigate contribution of polarization mode dispersion (PMD) to the polarimetry noise. We develop numerical models of the PS-OCT system including PMD and validate these models with empirical data. Using these models, we provide a framework for predicting noise levels, for processing signals to reduce noise, and for designing an optimized system. PMID:21935044

  5. Development and Design of Next-Generation Head-Mounted Ambulatory Microdose Positron-Emission Tomography (AM-PET) System.

    Science.gov (United States)

    Melroy, Samantha; Bauer, Christopher; McHugh, Matthew; Carden, Garret; Stolin, Alexander; Majewski, Stan; Brefczynski-Lewis, Julie; Wuest, Thorsten

    2017-05-19

    Several applications exist for a whole brain positron-emission tomography (PET) brain imager designed as a portable unit that can be worn on a patient's head. Enabled by improvements in detector technology, a lightweight, high performance device would allow PET brain imaging in different environments and during behavioral tasks. Such a wearable system that allows the subjects to move their heads and walk-the Ambulatory Microdose PET (AM-PET)-is currently under development. This imager will be helpful for testing subjects performing selected activities such as gestures, virtual reality activities and walking. The need for this type of lightweight mobile device has led to the construction of a proof of concept portable head-worn unit that uses twelve silicon photomultiplier (SiPM) PET module sensors built into a small ring which fits around the head. This paper is focused on the engineering design of mechanical support aspects of the AM-PET project, both of the current device as well as of the coming next-generation devices. The goal of this work is to optimize design of the scanner and its mechanics to improve comfort for the subject by reducing the effect of weight, and to enable diversification of its applications amongst different research activities.

  6. Translocator Protein-18 kDa (TSPO Positron Emission Tomography (PET Imaging and Its Clinical Impact in Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Anne-Claire Dupont

    2017-04-01

    Full Text Available In vivo exploration of activated microglia in neurodegenerative diseases is achievable by Positron Emission Tomography (PET imaging, using dedicated radiopharmaceuticals targeting the translocator protein-18 kDa (TSPO. In this review, we emphasized the major advances made over the last 20 years, thanks to TSPO PET imaging, to define the pathophysiological implication of microglia activation and neuroinflammation in neurodegenerative diseases, including Parkinson’s disease, Huntington’s disease, dementia, amyotrophic lateral sclerosis, multiple sclerosis, and also in psychiatric disorders. The extent and upregulation of TSPO as a molecular biomarker of activated microglia in the human brain is now widely documented in these pathologies, but its significance, and especially its protective or deleterious action regarding the disease’s stage, remains under debate. Thus, we exposed new and plausible suggestions to enhance the contribution of TSPO PET imaging for biomedical research by exploring microglia’s role and interactions with other cells in brain parenchyma. Multiplex approaches, associating TSPO PET radiopharmaceuticals with other biomarkers (PET imaging of cellular metabolism, neurotransmission or abnormal protein aggregates, but also other imaging modalities, and peripheral cytokine levels measurement and/or metabolomics analysis was considered. Finally, the actual clinical impact of TSPO PET imaging as a routine biomarker of neuroinflammation was put into perspective regarding the current development of diagnostic and therapeutic strategies for neurodegenerative diseases.

  7. PET

    DEFF Research Database (Denmark)

    Mariager, Rasmus Mølgaard; Schmidt, Regin; Heiberg, Morten Rievers

    PET handler om den hemmelige tjenestes arbejde under den kolde krig 1945-1989. Her fortæller Regin Schmidt, Rasmus Mariager og Morten Heiberg om de mest dramatiske og interessante sager fra PET's arkiv. PET er på flere måder en udemokratisk institution, der er sat til at vogte over demokratiet....... Dens virksomhed er skjult for offentligheden, den overvåger borgernes aktiviteter, og den registrerer følsomme personoplysninger. Historien om PET rejser spørgsmålet om, hvad man skal gøre, når befolkningen i et demokrati er kritisk indstillet over for overvågningen af lovlige politiske aktiviteter......, mens myndighederne mener, at det er nødvendigt for at beskytte demokratiet. PET er på en gang en fortælling om konkrete aktioner og begivenheder i PET's arbejde og et stykke Danmarkshistorie. Det handler om overvågning, spioner, politisk ekstremisme og international terrorisme.  ...

  8. Computed tomography automatic exposure control techniques in 18F-FDG oncology PET-CT scanning.

    Science.gov (United States)

    Iball, Gareth R; Tout, Deborah

    2014-04-01

    Computed tomography (CT) automatic exposure control (AEC) systems are now used in all modern PET-CT scanners. A collaborative study was undertaken to compare AEC techniques of the three major PET-CT manufacturers for fluorine-18 fluorodeoxyglucose half-body oncology imaging. An audit of 70 patients was performed for half-body CT scans taken on a GE Discovery 690, Philips Gemini TF and Siemens Biograph mCT (all 64-slice CT). Patient demographic and dose information was recorded and image noise was calculated as the SD of Hounsfield units in the liver. A direct comparison of the AEC systems was made by scanning a Rando phantom on all three systems for a range of AEC settings. The variation in dose and image quality with patient weight was significantly different for all three systems, with the GE system showing the largest variation in dose with weight and Philips the least. Image noise varied with patient weight in Philips and Siemens systems but was constant for all weights in GE. The z-axis mA profiles from the Rando phantom demonstrate that these differences are caused by the nature of the tube current modulation techniques applied. The mA profiles varied considerably according to the AEC settings used. CT AEC techniques from the three manufacturers yield significantly different tube current modulation patterns and hence deliver different doses and levels of image quality across a range of patient weights. Users should be aware of how their system works and of steps that could be taken to optimize imaging protocols.

  9. Higher fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) uptake in tuberculous compared to bacterial spondylodiscitis

    Energy Technology Data Exchange (ETDEWEB)

    Bassetti, Matteo; Merelli, Maria; Della Siega, Paola; Righi, Elda [Santa Maria della Misericordia University Hospital, Infectious Diseases Division, Udine (Italy); Di Gregorio, Fernando [Santa Maria della Misericordia University Hospital, Microbiology Unit, Udine (Italy); Screm, Maria; Scarparo, Claudio [Santa Maria della Misericordia University Hospital, Radiology Unit, Udine (Italy)

    2017-06-15

    Tuberculous spondylodiscitis can be difficult to diagnose because of its nonspecific symptoms and the similarities with non-tubercular forms of spinal infection. Fluorine-18-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG PET-CT) is increasingly used for the diagnosis and monitoring of tubercular diseases. Retrospective, case-control study comparing tuberculous spondylodiscitis with biopsy-confirmed pyogenic spondylodiscitis in the period 2010-2012. Ten cases of tuberculous spondylodiscitis and 20 controls were included. Compared to pyogenic, tuberculous spondylodiscitis was more frequent in younger patients (P = 0.01) and was more often associated with thoraco-lumbar tract lesions (P = 0.01) and multiple vertebral involvement (P = 0.01). Significantly higher maximum standardized uptake values (SUV) at FDG-PET were displayed by tuberculous spondylodiscitis compared to controls (12.4 vs. 7.3, P = 0.003). SUV levels above 8 showed the highest value of specificity (0.80). Mean SUV reduction of 48% was detected for tuberculous spondylodiscitis at 1-month follow-up. Higher SUV levels at FDG-PET were detected in tuberculous compared with pyogenic spondylodiscitis. PET-CT use appeared useful in the disease follow-up after treatment initiation. (orig.)

  10. Positron emission tomography of the heart

    International Nuclear Information System (INIS)

    Budinger, T.F.; Yano, Y.; Moyer, B.R.; Mathis, C.A.; Ganz, E.; Huesman, R.H.; Derenzo, S.E.

    1982-01-01

    Positron emission tomography (PET) of the heart can measure blood perfusion, metabolism of fatty acids, metabolism of sugars, uptake of amino acids and can quantitate infarction volume. The principles which are basic to PET instrumentation and procedures for quantitative studies of the heart muscle with examples of measurements of myocardial flow and metabolism, are reviewed

  11. Positron emission tomography of the heart

    International Nuclear Information System (INIS)

    Budinger, T.F.; Yano, Y.; Huesman, R.H.; Derenzo, S.E.; Moyer, B.R.; Mathis, C.A.; Ganz, E.; Knittel, B.

    1983-01-01

    Positron emission tomography (PET) of the heart can measure blood perfusion, metabolism of fatty acids, metabolism of sugars, uptake of amino acids and can quantitate infarction volume. The principles are reviewed which are basic to PET instrumentation and procedures for quantitative studies of human physiology with examples of measurements of myocardial flow and metabolism

  12. Measurement of acetylcholinesterase (AChE) activity in living brain by positron emission tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Irie, Toshiaki [National Inst. of Radiological Sciences, Chiba (Japan)

    1999-07-01

    Central cholinergic neuronal system has been known to be related to learning and memory, and its deficit is found in the brain of Alzheimer's disease (AD) and other degenerative disorders. Postmortem studies have shown that acetylcholinesterase (AChE), one of biochemical markers of central cholinergic nerve system, is consistently reduced in the cerebral cortex of patients with Alzheimer's disease (AD). Non-invasive mapping and/or measuring AChE activity in the living brain by positron emission tomography (PET) would be a useful tool for assessment of cholinergic dysfunction in AD and other disorders, and provide a direct method for validation of therapeutic efficacy of drugs, AChE inhibitors. We have challenged to measure AChE activity using tracers of substrate type, radiolabelled acetylcholine analogs, which are lipophilic enough to go across blood brain barrier and are metabolically trapped by AChE in the brain. The analogs designed, N-methylpiperidyl esters, were evaluated in terms of their metabolic rate and specificity against AChE. Studies examining the response to AChE activity showed metabolic accumulation of some analogs responded well to changes in cortical AChE activity in an animal model of AD. The study was further applied to living human by PET using [{sup 11}C]N-methylpiperidyl-4-acetate (MP4A), which was chosen on the basis of its reactivity and specificity suitable for the human cortical AChE. Regional cerebral metabolic rate of MP4A reflecting AChE activity was quantitatively determined using three compartment model analysis of dynamic PET data and the arterial input function obtained by TLC-radioluminography or plasma samples. The kinetic analyses showed that AChE activities estimated were well agree with those of postmortem examination in cerebral cortices and thalamus in healthy subjects, and that there was significant reduction of cortical AChE activity in patients with AD. The results suggest feasibility of the present method for

  13. Monte Carlo simulation of simultaneous radiation detection in the hybrid tomography system ClearPET-XPAD3/CT

    Energy Technology Data Exchange (ETDEWEB)

    Dávila, H. Olaya, E-mail: hernan.olaya@uptc.edu.co; Martínez, S. A. [Physics Department, Universidad Pedagógica y Tecnológica de Colombia, Tunja-Colombia (Colombia); Sevilla, A. C., E-mail: acsevillam@unal.edu.co; Castro, H. F. [Physics Department, Universidad Nacional de Colombia, Bogotá D.C - Colombia (Colombia)

    2016-07-07

    Using the Geant4 based simulation framework SciFW1, a detailed simulation was performed for a detector array in the hybrid tomography prototype for small animals called ClearPET / XPAD, which was built in the Centre de Physique des Particules de Marseille. The detector system consists of an array of phoswich scintillation detectors: LSO (Lutetium Oxy-ortosilicate doped with cerium Lu{sub 2}SiO{sub 5}:Ce) and LuYAP (Lutetium Ortoaluminate of Yttrium doped with cerium Lu{sub 0.7}Y{sub 0.3}AlO{sub 3}:Ce) for Positron Emission Tomography (PET) and hybrid pixel detector XPAD for Computed Tomography (CT). Simultaneous acquisition of deposited energy and the corresponding time - position for each recorded event were analyzed, independently, for both detectors. interference between detection modules for PET and CT. Information about amount of radiation reaching each phoswich crystal and XPAD detector using a phantom in order to study the effectiveness by radiation attenuation and influence the positioning of the radioactive source {sup 22}Na was obtained. The simulation proposed will improve distribution of detectors rings and interference values will be taken into account in the new versions of detectors.

  14. Monte Carlo simulation of simultaneous radiation detection in the hybrid tomography system ClearPET-XPAD3/CT

    Science.gov (United States)

    Dávila, H. Olaya; Sevilla, A. C.; Castro, H. F.; Martínez, S. A.

    2016-07-01

    Using the Geant4 based simulation framework SciFW1, a detailed simulation was performed for a detector array in the hybrid tomography prototype for small animals called ClearPET / XPAD, which was built in the Centre de Physique des Particules de Marseille. The detector system consists of an array of phoswich scintillation detectors: LSO (Lutetium Oxy-ortosilicate doped with cerium Lu2SiO5:Ce) and LuYAP (Lutetium Ortoaluminate of Yttrium doped with cerium Lu0.7Y0.3AlO3:Ce) for Positron Emission Tomography (PET) and hybrid pixel detector XPAD for Computed Tomography (CT). Simultaneous acquisition of deposited energy and the corresponding time - position for each recorded event were analyzed, independently, for both detectors. interference between detection modules for PET and CT. Information about amount of radiation reaching each phoswich crystal and XPAD detector using a phantom in order to study the effectiveness by radiation attenuation and influence the positioning of the radioactive source 22Na was obtained. The simulation proposed will improve distribution of detectors rings and interference values will be taken into account in the new versions of detectors.

  15. [18F]Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/Computed Tomography (CT) in Suspected Recurrent Breast Cancer: A Prospective Comparative Study of Dual-Time-Point FDG-PET/CT, Contrast-Enhanced CT, and Bone Scintigraphy.

    Science.gov (United States)

    Hildebrandt, Malene Grubbe; Gerke, Oke; Baun, Christina; Falch, Kirsten; Hansen, Jeanette Ansholm; Farahani, Ziba Ahangarani; Petersen, Henrik; Larsen, Lisbet Brønsro; Duvnjak, Sandra; Buskevica, Inguna; Bektas, Selma; Søe, Katrine; Jylling, Anne Marie Bak; Ewertz, Marianne; Alavi, Abass; Høilund-Carlsen, Poul Flemming

    2016-06-01

    To prospectively investigate the diagnostic accuracy of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) with dual-time-point imaging, contrast-enhanced CT (ceCT), and bone scintigraphy (BS) in patients with suspected breast cancer recurrence. One hundred women with suspected recurrence of breast cancer underwent 1-hour and 3-hour FDG-PET/CT, ceCT, and BS within approximately 10 days. The study was powered to estimate the precision of the individual imaging tests. Images were visually interpreted using a four-point assessment scale, and readers were blinded to other test results. The reference standard was biopsy along with treatment decisions and clinical follow-up (median, 17 months). FDG-PET/CT resulted in no false negatives and fewer false positives than the other imaging techniques. Accuracy of results were similar for 1-hour and 3-hour FDG-PET/CT. For distant recurrence, the area under the receiver operating curve was 0.99 (95% CI, 0.97 to 1) for FDG-PET/CT, 0.84 (95% CI, 0.73 to 0.94) for ceCT, and 0.86 (95% CI, 0.77 to 0.94) for the combined ceCT+BS. Of 100 patients, 22 (22%) were verified with distant recurrence, and 18 of these had bone involvement. Nineteen patients (19%) had local recurrence only. In exploratory analyses, diagnostic accuracy of FDG-PET/CT was better than ceCT alone or ceCT combined with BS in diagnosing distant, bone, and local recurrence, shown by a greater area under the receiver operating curve and higher sensitivity, specificity, and superior likelihood ratios. FDG-PET/CT was accurate in diagnosing recurrence in breast cancer patients. It allowed for distant recurrence to be correctly ruled out and resulted in only a small number of false-positive cases. Exploratory findings suggest that FDG-PET/CT has greater accuracy than conventional imaging technologies in this patient group. © 2016 by American Society of Clinical Oncology.

  16. Development and Design of Next-Generation Head-Mounted Ambulatory Microdose Positron-Emission Tomography (AM-PET System

    Directory of Open Access Journals (Sweden)

    Samantha Melroy

    2017-05-01

    Full Text Available Several applications exist for a whole brain positron-emission tomography (PET brain imager designed as a portable unit that can be worn on a patient’s head. Enabled by improvements in detector technology, a lightweight, high performance device would allow PET brain imaging in different environments and during behavioral tasks. Such a wearable system that allows the subjects to move their heads and walk—the Ambulatory Microdose PET (AM-PET—is currently under development. This imager will be helpful for testing subjects performing selected activities such as gestures, virtual reality activities and walking. The need for this type of lightweight mobile device has led to the construction of a proof of concept portable head-worn unit that uses twelve silicon photomultiplier (SiPM PET module sensors built into a small ring which fits around the head. This paper is focused on the engineering design of mechanical support aspects of the AM-PET project, both of the current device as well as of the coming next-generation devices. The goal of this work is to optimize design of the scanner and its mechanics to improve comfort for the subject by reducing the effect of weight, and to enable diversification of its applications amongst different research activities.

  17. Use of F-18 fluoro deoxyglucose (FDG) positron emission tomography (PET) in the assessment of malignant mesothelioma

    International Nuclear Information System (INIS)

    Brown, F.M.M.; Pathmaraj, K.; Berlangieri, S.U.; Knight, S.; Clarke, C.P.; Scott, A.M.

    2002-01-01

    Full text: Australia has the highest mesothelioma incidence rate in the world and the incidence of Mesothelioma is increasing. Therapy for Mesothelioma involves surgery (including phototherapy), radiotherapy and chemotherapy. Computed tomography (CT) is frequently used to stage the extent of Mesothelioma. This study aimed to evaluate the utility of FDG PET in staging Mesothelioma and monitoring response to therapy. Nineteen F-18 FDG PET was performed at the A and RMC Centre for PET in 14 patients (13M: 1F, age range 39-77 years, mean age 58 years) with biopsy proven malignant pleural Mesothelioma. Patients were referred for staging (5 patients) or evaluation of patients post surgery or phototherapy (9 patients). 3 patients had more than 1 PET scan. FDG scans were reviewed with full access to the CT report. Standardised Uptake Values (SUV) were performed in all scans in regions of maximal FDG uptake corresponding to CT abnormality. Normal lung SUVs were also calculated. Follow-up was possible in all patients to the time of death or December 2001 (Follow-up 4 - 45 months, mean 16 months; 3 patients still alive). All FDG PET scans were positive for FDG-avid pleural tissue. No surgery was deferred due to FDG PET findings. In 3 patients mediastinal nodes were identified pre-surgery. Post surgical therapy assessment by FDG PET (9 patients) guided therapy by confirming disease progression or further characterising post-operative changes when CT findings were uncertain. FDG PET was able to more accurately distinguish between collapse/consolidation and recurrent disease than CT scan. Almost all post-surgical scans were performed in patients who received phototherapy. Different Mesothelioma histological subtypes could not be differentiated by SUV criteria. False positive FDG PET studies were seen in 3 patients, all of whom had post-surgical empyemas. In conclusion, FDG PET has a potential role in the management of malignant mesothelioma patients, particularly in the post

  18. Combined positron emission tomography/computed tomography (PET/CT) for clinical oncology: technical aspects and acquisition protocols

    International Nuclear Information System (INIS)

    Beyer, T.

    2004-01-01

    Combined PET/CT imaging is a non-invasive means of reviewing both, the anatomy and the molecular pathways of a patient during a quasi-simultaneous examination. Since the introduction of the prototype PET/CT in 1998 a rapid development of this imaging technology is being witnessed. The incorporation of fast PET detector technology into PET/CT designs and the routine use of the CT transmission images for attenuation correction of the PET allow for anato-metabolic whole-body examinations to be completed in less than 30 min. Thus, PET/CT imaging offers a logistical advantage to both, the patient and the clinicians since the two complementary exams - whenever clinically indicated - can be performed almost at the same time and a single integrated report can be created. Nevertheless, a number of pit-falls, primarily from the use of CT-based attenuation correction, have been identified and are being addressed through optimized acquisition protocols. It is fair to say, that PET/CT has been integrated in the diagnostic imaging arena, and in many cases has led to a close collaboration between different, yet complementary diagnostic and therapeutic medical disciplines. (orig.)

  19. 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...

  20. PET, Positron emission tomography: Presentation of a clinical case; PET, Tomografia por emision de positrones: Presentacion de un caso clinico

    Energy Technology Data Exchange (ETDEWEB)

    Sierralta C, Paulina; Jofre M, M Josefina; Gonzalez E, Patricio; Massardo V, Teresa; Humeres A, Pamela; Canessa G, Jose [Hospital Militar de Santiago, Servicio de Medicina Nuclear, Centro PET de Imagenes Moleculares, Santiago (Chile)

    2003-07-01

    A patient with a solitary pulmonary nodule is presented. She was studied with PET using F-18 FDG. The metabolic images demonstrated increased uptake in the nodule and 2 additional areas suggestive of extension, not seen in anatomic diagnostic procedures. These findings were compatible with a malignant tumour with metastasis (au)

  1. 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography-Based Radiotherapy Target Volume Definition in Non-Small-Cell Lung Cancer: Delineation by Radiation Oncologists vs. Joint Outlining With a PET Radiologist?

    International Nuclear Information System (INIS)

    Hanna, Gerard G.; Carson, Kathryn J.; Lynch, Tom; McAleese, Jonathan; Cosgrove, Vivian P.; Eakin, Ruth L.; Stewart, David P.; Zatari, Ashraf; O'Sullivan, Joe M.; Hounsell, Alan R.

    2010-01-01

    Purpose: 18 F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) has benefits in target volume (TV) definition in radiotherapy treatment planning (RTP) for non-small-cell lung cancer (NSCLC); however, an optimal protocol for TV delineation has not been determined. We investigate volumetric and positional variation in gross tumor volume (GTV) delineation using a planning PET/CT among three radiation oncologists and a PET radiologist. Methods and Materials: RTP PET/CT scans were performed on 28 NSCLC patients (Stage IA-IIIB) of which 14 patients received prior induction chemotherapy. Three radiation oncologists and one PET radiologist working with a fourth radiation oncologist independently delineated the GTV on CT alone (GTV CT ) and on fused PET/CT images (GTV PETCT ). The mean percentage volume change (PVC) between GTV CT and GTV PETCT for the radiation oncologists and the PVC between GTV CT and GTV PETCT for the PET radiologist were compared using the Wilcoxon signed-rank test. Concordance index (CI) was used to assess both positional and volume change between GTV CT and GTV PETCT in a single measurement. Results: For all patients, a significant difference in PVC from GTV CT to GTV PETCT exists between the radiation oncologist (median, 5.9%), and the PET radiologist (median, -0.4%, p = 0.001). However, no significant difference in median concordance index (comparing GTV CT and GTV FUSED for individual cases) was observed (PET radiologist = 0.73; radiation oncologists = 0.66; p = 0.088). Conclusions: Percentage volume changes from GTV CT to GTV PETCT were lower for the PET radiologist than for the radiation oncologists, suggesting a lower impact of PET/CT in TV delineation for the PET radiologist than for the oncologists. Guidelines are needed to standardize the use of PET/CT for TV delineation in RTP.

  2. 18F-fluorodeoxyglucose positron emission tomography/computed tomography-based radiotherapy target volume definition in non-small-cell lung cancer: delineation by radiation oncologists vs. joint outlining with a PET radiologist?

    Science.gov (United States)

    Hanna, Gerard G; Carson, Kathryn J; Lynch, Tom; McAleese, Jonathan; Cosgrove, Vivian P; Eakin, Ruth L; Stewart, David P; Zatari, Ashraf; O'Sullivan, Joe M; Hounsell, Alan R

    2010-11-15

    (18)F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) has benefits in target volume (TV) definition in radiotherapy treatment planning (RTP) for non-small-cell lung cancer (NSCLC); however, an optimal protocol for TV delineation has not been determined. We investigate volumetric and positional variation in gross tumor volume (GTV) delineation using a planning PET/CT among three radiation oncologists and a PET radiologist. RTP PET/CT scans were performed on 28 NSCLC patients (Stage IA-IIIB) of which 14 patients received prior induction chemotherapy. Three radiation oncologists and one PET radiologist working with a fourth radiation oncologist independently delineated the GTV on CT alone (GTV(CT)) and on fused PET/CT images (GTV(PETCT)). The mean percentage volume change (PVC) between GTV(CT) and GTV(PETCT) for the radiation oncologists and the PVC between GTV(CT) and GTV(PETCT) for the PET radiologist were compared using the Wilcoxon signed-rank test. Concordance index (CI) was used to assess both positional and volume change between GTV(CT) and GTV(PETCT) in a single measurement. For all patients, a significant difference in PVC from GTV(CT) to GTV(PETCT) exists between the radiation oncologist (median, 5.9%), and the PET radiologist (median, -0.4%, p = 0.001). However, no significant difference in median concordance index (comparing GTV(CT) and GTV(FUSED) for individual cases) was observed (PET radiologist = 0.73; radiation oncologists = 0.66; p = 0.088). Percentage volume changes from GTV(CT) to GTV(PETCT) were lower for the PET radiologist than for the radiation oncologists, suggesting a lower impact of PET/CT in TV delineation for the PET radiologist than for the oncologists. Guidelines are needed to standardize the use of PET/CT for TV delineation in RTP. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Quantification of atherosclerotic plaque activity and vascular inflammation using [18-F] fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT).

    Science.gov (United States)

    Mehta, Nehal N; Torigian, Drew A; Gelfand, Joel M; Saboury, Babak; Alavi, Abass

    2012-05-02

    Conventional non-invasive imaging modalities of atherosclerosis such as coronary artery calcium (CAC) and carotid intimal medial thickness (C-IMT) provide information about the burden of disease. However, despite multiple validation studies of CAC, and C-IMT, these modalities do not accurately assess plaque characteristics, and the composition and inflammatory state of the plaque determine its stability and, therefore, the risk of clinical events. [(18)F]-2-fluoro-2-deoxy-D-glucose (FDG) imaging using positron-emission tomography (PET)/computed tomography (CT) has been extensively studied in oncologic metabolism. Studies using animal models and immunohistochemistry in humans show that FDG-PET/CT is exquisitely sensitive for detecting macrophage activity, an important source of cellular inflammation in vessel walls. More recently, we and others have shown that FDG-PET/CT enables highly precise, novel measurements of inflammatory activity of activity of atherosclerotic plaques in large and medium-sized arteries. FDG-PET/CT studies have many advantages over other imaging modalities: 1) high contrast resolution; 2) quantification of plaque volume and metabolic activity allowing for multi-modal atherosclerotic plaque quantification; 3) dynamic, real-time, in vivo imaging; 4) minimal operator dependence. Finally, vascular inflammation detected by FDG-PET/CT has been shown to predict cardiovascular (CV) events independent of traditional risk factors and is also highly associated with overall burden of atherosclerosis. Plaque activity by FDG-PET/CT is modulated by known beneficial CV interventions such as short term (12 week) statin therapy as well as longer term therapeutic lifestyle changes (16 months). The current methodology for quantification of FDG uptake in atherosclerotic plaque involves measurement of the standardized uptake value (SUV) of an artery of interest and of the venous blood pool in order to calculate a target to background ratio (TBR), which is

  4. Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument

    Directory of Open Access Journals (Sweden)

    Raczyński Lech

    2016-03-01

    Full Text Available Nowadays, in positron emission tomography (PET systems, a time of flight (TOF information is used to improve the image reconstruction process. In TOF-PET, fast detectors are able to measure the difference in the arrival time of the two gamma rays, with the precision enabling to shorten significantly a range along the line-of-response (LOR where the annihilation occurred. In the new concept, called J-PET scanner, gamma rays are detected in plastic scintillators. In a single strip of J-PET system, time values are obtained by probing signals in the amplitude domain. Owing to compressive sensing (CS theory, information about the shape and amplitude of the signals is recovered. In this paper, we demonstrate that based on the acquired signals parameters, a better signal normalization may be provided in order to improve the TOF resolution. The procedure was tested using large sample of data registered by a dedicated detection setup enabling sampling of signals with 50-ps intervals. Experimental setup provided irradiation of a chosen position in the plastic scintillator strip with annihilation gamma quanta.

  5. Clinical investigations on the use of positron emission tomography (PET) for target volume definition in radiation therapy planning; Klinische Untersuchungen zum Einsatz der Positronen-Emissions-Tomographie (PET) in der Zielvolumendefinition bei der Bestrahlungsplanung

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Ingo G.

    2014-12-05

    The aim of the present study was to evaluate the clinical value of positron emission tomography (PET) for target volume definition in different tumor entities using different tracers and taking pretreatment of patients into account. The study collective comprised 109 patients with 112 target volumes. In 48 patients with skull base meningiomas (SBM) and 42 patients with meningiomas of other localizations (SOM) undergoing fractionated stereotactic radiation therapy the gross tumor volumes (SBM, n=48; SOM, n=39) based on magnetic resonance imaging/computed tomography (MRI/CT) and {sup 68}Ga-DOTATOC-PET were compared retrospectively. Additionally, in 19 patients with liver metastasis from colorectal cancer (LM-CRC) treated in 25 CT guided brachytherapy sessions the clinical target volumes (CTV) either based on MRI/CT or {sup 18}F-FDG-PET were compared retrospectively. The spatial agreement of the target volumes was analyzed using the Dice similarity coefficient (DSC). The association of DSC, tumor entity and pretreatment was analyzed using the general linear model (GLM). Metric parameters are given as median (25th/75th-quartile). In the complete patient sample the PET based target volume was 24.1 (10.8/51.2) ml and, thus, significantly (p<0.001) increased by 18.9% (-3.6%/62.7%) compared to the MRI/CT based target volume of 20.8 (8.6/45.0) ml. In the subgroup of LM-CRC, the PET based target volume was significantly increased by 24.4% (0%/ 71.4%; p=0.021), and in patients with SBM it was increased by 23.9%(-1.7%/65.7%; p=0.003) whereas in SOM the difference of 8.0% (-3.6%/51.7%; p=0.199) was not significant. The DSC for PET and MRI/CT based target volumes was 0.66 (0.46/0.76) in the whole study group and varied between 0.65 (0.46/0.71) in patients with SBM and 0.70 (0.40/0.79) in patients with SOM. In pre-treated patients with LM-CRC a significant lower DSC of 0.62 (0.41/0.66) was observed in comparison to 0.84 (0.70/0.96) in untreated patients (significant interaction

  6. Cerebral lesions and event-related potential P300 using positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Sakai, Yasujiro; Okamoto, Kazuma; Tanaka, Makoto; Kondoh, Susumu; Hirai, Shunsaku

    1993-01-01

    To determine what lesions are involved in prolonging event-related potential P300 latency, regional cerebral blood flow (rCBF) and metabolism were investigated by positron emission tomography (PET) in a total of 40 patients with neurologic diseases (12 with chronic cerebrovascular disorder, 9 with spino-cerebellar degeneration, 4 with Alzheimer's type dementia, 4 with amyotrophic lateral sclerosis, and 11 with miscellaneous diseases). There was inverse correlation between rCBF and P300 latency in terms of any of the whole, left, and right hemispheres: P300 latency was associated with decreased rCBF. This was more noticeable in the cerebral cortex than white matter and in the right than left hemisphere, although there was no significant difference between them. In none of the regions, however, was there significant correlation between cerebral oxygen consumption and P300 latency. When the right and left frontal, temporal, parietal and occipital cortexes, thalamus, putamen, and caudatum were examined as regions of interest, there was significantly inverse correlation between rCBF and P300 latency in all regions except for the occipital cortex. This was more noticeable on the right than the left side, although no significant difference was observed. Cerebral oxygen consumption in these lesions did not correlate with P300 latency. In the study on bilateral rCBF difference, decreased rCBF confined to the right parietal lobe, bilateral thalamus and bilateral temporal lobes was found to be associated with a significantly prolonged P300 latency. Thus, rCBF in these regions seemed to be particularly responsible for P300 latency. (N.K.)

  7. Cerebral lesions and event-related potential P300 using positron emission tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Yasujiro; Okamoto, Kazuma; Tanaka, Makoto; Kondoh, Susumu; Hirai, Shunsaku (Gunma Univ., Maebashi (Japan). School of Medicine)

    1993-06-01

    To determine what lesions are involved in prolonging event-related potential P300 latency, regional cerebral blood flow (rCBF) and metabolism were investigated by positron emission tomography (PET) in a total of 40 patients with neurologic diseases (12 with chronic cerebrovascular disorder, 9 with spino-cerebellar degeneration, 4 with Alzheimer's type dementia, 4 with amyotrophic lateral sclerosis, and 11 with miscellaneous diseases). There was inverse correlation between rCBF and P300 latency in terms of any of the whole, left, and right hemispheres: P300 latency was associated with decreased rCBF. This was more noticeable in the cerebral cortex than white matter and in the right than left hemisphere, although there was no significant difference between them. In none of the regions, however, was there significant correlation between cerebral oxygen consumption and P300 latency. When the right and left frontal, temporal, parietal and occipital cortexes, thalamus, putamen, and caudatum were examined as regions of interest, there was significantly inverse correlation between rCBF and P300 latency in all regions except for the occipital cortex. This was more noticeable on the right than the left side, although no significant difference was observed. Cerebral oxygen consumption in these lesions did not correlate with P300 latency. In the study on bilateral rCBF difference, decreased rCBF confined to the right parietal lobe, bilateral thalamus and bilateral temporal lobes was found to be associated with a significantly prolonged P300 latency. Thus, rCBF in these regions seemed to be particularly responsible for P300 latency. (N.K.).

  8. Granulomatous disease: is it a nuisance or an asset during PET/computed tomography evaluation of lung cancers?

    Science.gov (United States)

    Chundru, Surya; Wong, Ching-yee Oliver; Wu, Dafang; Balon, Helena; Palka, Jane; Chang, Chih-Yung; Gaskill, Marianne; Cheng, Cheng-Yi; Huang, Wen-Sheng; Fink-Bennett, Darlene

    2008-07-01

    To evaluate combined PET-computed tomography (CT) criteria for differentiating between granulomatous disease (GD) and malignancy (CA) in oncologic PET-CT studies. Sixty-two patients who were referred for fluoro-2-deoxyglucose (FDG) PET-CT evaluation of pulmonary lesion(s) without a history of concurrent infection were studied. PET-CT was performed 1.5 h after intravenous administration of 555 MBq 18F-FDG in the fasting state with oral contrast. Combined PET-CT criteria including (i) calcifications (Ca2+) within lymph nodes, (ii) Ca2+ in lung nodules, (iii) liver and/or spleen Ca2+, (iv) locations of lung lesion(s), (v) hilar FDG uptake, (vi) comparison of lung versus maximum mediastinal FDG uptake, (vii) lymph node uptake not in the most probable lymphatic drainage pathway from a particular lung lesion, and (viii) extra pulmonary abnormal FDG uptake were each assigned a numerical score (0-3) with progressively higher score and sum of scores toward the increasing likelihood of GD. These patients either had pathological confirmation by biopsy/resection or were followed radiographically for a period of 2 years (CA=13; GD=49). Discriminant analysis was performed on all the above criteria with this gold standard. Simple t-test and box plot analysis were also performed on the summation of the scores (from 0 in CA to 13 in GD). When all eight criteria were entered into discriminant analysis, the combined PET-CT criteria classified correctly 71% of patients with a sensitivity of 65% and specificity of 92% for GD. The most significant discriminating criterion was FDG uptake in the lung lesion(s) less than maximum mediastinal uptake (P=0.01). The sum scores in GD and CA were significantly different (4.9+/-2.4 vs. 3.2+/-1.5, respectively, P=0.014). Box plots showed a clear separation at a cut-off value of around 3.5. Results show that the set of combined PET-CT criteria are highly specific for GD, which is not necessarily a nuisance during oncologic evaluation. Knowledge of

  9. Risk Stratification of Thyroid Incidentalomas Found on PET/CT: The Value of Iodine Content on Noncontrast Computed Tomography.

    Science.gov (United States)

    Kim, Dongwoo; Hwang, Sang Hyun; Cha, Jongtae; Jo, Kwanhyeong; Lee, Narae; Yun, Mijin

    2015-11-01

    The Hounsfield unit (HU) ratio of thyroid nodules was assessed compared to the contralateral thyroid lobe on noncontrast computed tomography (CT) to stratify further the risk of malignancy in thyroid incidentalomas found on 18F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/CT (PET/CT). This retrospective analysis included 82 patients who had thyroid incidentalomas on PET/CT in 2011. On PET/CT, the maximal standardized uptake value ratios of the thyroid nodule compared to liver (T/BSUV) and the HU ratios of the thyroid nodule compared to contralateral thyroid lobe (T/BHU) were calculated. Diagnostic performances of the T/BSUV and T/BHU were compared. The area under the curve of T/BHU was higher than that of T/BSUV (0.941 vs. 0.689, p risk of malignancy was much higher (71.1%) in nodules with a T/BHU cutoff value ≤0.68, whereas it was 0% in nodules with a T/BHU of >0.68. In this study, there were 18 nodules with nondiagnostic (n = 7) or atypia of undetermined significance or follicular lesion of undetermined significance cytologies (n = 11) after fine-needle aspiration biopsy (FNAB). When the T/BHU cutoff value was applied, three (60%) of the five nodules with a T/BHU of ≤0.68 were found to be papillary carcinomas. The remaining 13 nodules with a T/BHU of >0.68 were all benign with a risk of malignancy of 0%. T/BHU is a simple and effective parameter to stratify the risk of malignancy in thyroid incidentalomas found on PET/CT. This may be of clinical relevance in those nodules with nondiagnostic or undetermined significance cytologies upon FNAB in the scheme of current clinical practice.

  10. FDG-PET in the diagnosis of neuropsychiatric Lupus erythematosus and comparison with computed tomography and magnetic resonance imaging. Einsatz der FDG-PET bei der Diagnostik des zentralnervoesen Lupus erythematodes und Vergleich mit CT und MRI

    Energy Technology Data Exchange (ETDEWEB)

    Stoppe, G [Medizinische Hochschule Hannover (Germany, F.R.). Neurologische Klinik mit Klinischer Neurophysiologie; Wildhagen, K [Medizinische Hochschule Hannover (Germany, F.R.). Abt. Immunologie und Transfusionsmedizin; Meyer, G J [Medizinische Hochschule Hannover (Germany, F.R.). Abt. Nuklearmedizin und Spezielle Biophysik; Schober, O [Muenster Univ. (Germany, F.R.). Klinik und Poliklinik fuer Nuklearmedizin

    1989-10-01

    Central nervous system involvement has been found in 30-75% of all cases of systemic lupus erythematosus (SLE). Up to now, clinical diagnosis is difficult and there are no markers for disease activity. We have compared cranial computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) using fluorodesoxyglucose (FDG) in two cases. FDG-PET is shown to be the most sensitive method demonstrating even reversible deficits and a better correlation with other neurological findings. MRI seems to be more sensitive than CT. A survey of the literature concerning imaging methods in neuropsychiatric SLE is given. The special problem of neuronal desactivation by antineuronal activity is discussed. (orig.).

  11. Effects of four instruments on coronal pre-enlargement by using cone beam computed tomography.

    Science.gov (United States)

    Sanfelice, Cintia Mussoline; da Costa, Fernanda Botega; Reis Só, Marcus Vinícius; Vier-Pelisser, Fabiana; Souza Bier, Carlos Alexandre; Grecca, Fabiana Soares

    2010-05-01

    This ex vivo study used cone beam computed tomography to evaluate the amount of dentin removal from the distal wall of the mesial canal of human mandibular first molars caused by 4 instruments used to flare the cervical third. Thirty-two mesial roots were divided into 4 groups prepared by using ProTaper, K3, Gates-Glidden, or LA Axxess. The dentin thickness of the distal cervical wall of mesial canals was measured before and after the preparation by using computed tomography and Adobe Photoshop software. There was no statistically significant difference between the study groups (P > 05). All the instruments used for cervical preparation seemed to be safe and did not damage the dentin structure of the distal wall of mesial root canals of mandibular molars. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. [Prognostic value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in extensive-stage small cell lung cancer].

    Science.gov (United States)

    Ding, C Y; Guo, Z; Li, Y Y; Li, T R

    2017-11-23

    Objective: To investigated the prognostic value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in extensive-stage small cell lung cancer (ES -SCLC). Methods: Fifty-five patients with ES-SCLC who underwent pretreatment (18)F-FDG PET-CT were retrospectively recruited in this study. The correlations of maximum standardized uptake value (SUVmax) of primary lesion, metabolic tumor volume (MTV) of primary lesion (MTVp), total lesion glycolysis (TLG) of primary lesion (TLGp), the highest SUVmax of all lesions, the sum of metabolic volume (MTV sum), the sum of total lesions glycolysis (TLGsum) and clinical factors were analyzed. Results: The SUVmax, MTVp, TLGp, the highest SUVmax, MTVsum and TLGsum of 55 patients were 11.34±7.02, 29.61 cm(3,) 207.72, 13.61±7.10, 123.57 cm(3) and 988.48, respectively. The SUVmax of primary lesion, MTVp and TLGp were correlated with tumor type and the maximal tumor length, respectively(all P CT has certain prognostic value of patients with ES-SCLC. MTVsum and TLGsum are the independent predictors of PFS, and TLGsum is also an independent predictor of OS.

  13. Positron-molecule interactions and corresponding positron attachment to molecules. As a basis for positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Tachikawa, Masanori; Kimura, Mineo; Pichl, Lukas

    2007-01-01

    Through positron and electron interactions, they annihilate emitting primarily two gamma rays with 180-degree opposite directions. Positron spectroscopy using the characteristics of these gamma rays has been employed for analyzing various properties of material as well as for positron emission tomography (PET). However, its fundamental physics of positron-electron interactions and resulting features of emitting gamma rays are not well understood. By obtaining better understanding of positron interactions, it should become possible to provide the firm bases for positron spectroscopy in finer accuracy and quality. Here, we propose a significant mechanism for positron annihilation through positron attachment process, which may help increase the quality of positron spectroscopy. (author)

  14. Detection of recurrent colorectal carcinoma with 18F-FDG positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Scott, A.M.; Berlangieri, S.U.; Zalcberg, J.; Fox, R.; Cebon, J.; McLeish, A.; Thomas, D.; Chan, G.; Tochon-Danguy, H.; Egan, G.F.; McKay, W.J.

    1998-01-01

    Full text: The appropriate surgical management of recurrent colorectal carcinoma is dependent on the accurate detection of possible primary site recurrence and distant spread of disease. The aim of this study was therefore to evaluate the clinical accuracy of 18 F-FDG PET in detecting recurrent colorectal carcinoma. Over a 12-month period we have performed 21 studies in 17 patients (12 M: 5 F, age range 52-73 y) with known or suspected recurrent colorectal carcinoma. All patients underwent PET imaging of the abdomen and pelvis, or whole body imaging, with a whole body PET scanner (Siemens 951/R) following injection of 400 MBq of 18 F-FDG. All PET studies were interpreted with full knowledge of CT findings, and results were compared to subsequent surgical findings, biopsy or follow-up by conventional imaging methods (e.g. CT scan). Of the 21 studies performed, 18 (86%) had abnormal sites of 18 F-FDG uptake; all sites were subsequently confirmed as recurrent colorectal carcinoma. PET identified a total of 30 sites of disease in the pelvis (n = 4), abdomen (n =10), liver (n = 6), thorax (n = 9) and abdominal surgical scar (n 1), and was false negative in one lung lesion. CT scan correctly identified 14 sites as recurrent tumour; 9/12 patients (pts) with equivocal changes on CT scan had recurrent disease identified by PET. In 10 pts with elevated serum CEA but negative or equivocal CT scans, PET correctly identified 8 pts with proven recurrent disease. Previously unsuspected disease was found at six sites by PET. Lesions as small as 1.2 cm proven at surgery were identified with PET. In conclusion, this study shows 18 F-FDG PET to be a promising method for accurate detection of recurrent colorectal carcinoma

  15. In vitro comparative study of manual and mechanical rotary instrumentation of root canals using computed tomography.

    Science.gov (United States)

    Limongi, Orlando; de Albuquerque, Diana Santana; Baratto Filho, Flares; Vanni, José Roberto; de Oliveira, Elias P Motcy; Barletta, Fernando Branco

    2007-01-01

    This in vitro study compared, using computed tomography (CT), the amount of dentin removed from root canal walls by manual and mechanical rotary instrumentation techniques. Forty mandibular incisors with dental crown and a single canal were selected. The teeth were randomly assigned to two groups, according to the technique used for root canal preparation: Group I - manual instrumentation with stainless steel files; Group II - mechanical instrumentation with RaCe rotary nickel-titanium instruments. In each tooth, root dentin thickness of the buccal, lingual, mesial and distal surfaces in the apical, middle and cervical thirds of the canal was measured (in mm) using a multislice CT scanner (Siemens Emotion, Duo). Data were stored in the SPSS v. 11.5 and SigmaPlot 2001 v. 7.101 softwares. After crown opening, working length was determined, root canals were instrumented and new CT scans were taken for assessment of root dentin thickness. Pre- and post-instrumentation data were compared and analyzed statistically by ANOVA and Tukey's post-hoc test for significant differences (p=0.05). Based on the findings of this study, it may be concluded that regarding dentin removal from root canal walls during instrumentation, neither of the techniques can be considered more effective than the other.

  16. The value of FDG positron emission tomography/computerised tomography (PET/CT) in pre-operative staging of colorectal cancer: a systematic review and economic evaluation.

    Science.gov (United States)

    Brush, J; Boyd, K; Chappell, F; Crawford, F; Dozier, M; Fenwick, E; Glanville, J; McIntosh, H; Renehan, A; Weller, D; Dunlop, M

    2011-09-01

    In the UK, colorectal cancer (CRC) is the third most common malignancy (behind lung and breast cancer) with 37,514 cases registered in 2006: around two-thirds (23,384) in the colon and one-third (14,130) in the rectum. Treatment of cancers of the colon can vary considerably, but surgical resection is the mainstay of treatment for curative intent. Following surgical resection, there is a comprehensive assessment of the tumour, it's invasion characteristics and spread (tumour staging). A number of imaging modalities are used in the pre-operative staging of CRCs including; computerised tomography (CT), magnetic resonance imaging, ultrasound imaging and positron emission tomography (PET). This report examines the role of CT in combination with PET scanning (PET/CT 'hybrid' scan). The research objectives are: to evaluate the diagnostic accuracy and therapeutic impact of fluorine-18-deoxyglucose (FDG) PET/CT for the pre-operative staging of primary, recurrent and metastatic cancer using systematic review methods; undertake probabilistic decision-analytic modelling (using Monte Carlo simulation); and conduct a value of information analysis to help inform whether or not there is potential worth in undertaking further research. For each aspect of the research - the systematic review, the handsearch study and the economic evaluation - a database was assembled from a comprehensive search for published and unpublished studies, which included database searches, reference lists search and contact with experts. In the systematic review prospective and retrospective patient series (diagnostic cohort) and randomised controlled trials (RCTs) were eligible for inclusion. Both consecutive series and series that are not explicitly reported as consecutive were included. Two reviewers extracted all data and applied the criteria independently and resolved disagreements by discussion. Data to populate 2 × 2 contingency tables consisting of the number of true positives, true negatives

  17. External radioactive markers for PET data-driven respiratory gating in positron emission tomography.

    Science.gov (United States)

    Büther, Florian; Ernst, Iris; Hamill, James; Eich, Hans T; Schober, Otmar; Schäfers, Michael; Schäfers, Klaus P

    2013-04-01

    Respiratory gating is an established approach to overcoming respiration-induced image artefacts in PET. Of special interest in this respect are raw PET data-driven gating methods which do not require additional hardware to acquire respiratory signals during the scan. However, these methods rely heavily on the quality of the acquired PET data (statistical properties, data contrast, etc.). We therefore combined external radioactive markers with data-driven respiratory gating in PET/CT. The feasibility and accuracy of this approach was studied for [(18)F]FDG PET/CT imaging in patients with malignant liver and lung lesions. PET data from 30 patients with abdominal or thoracic [(18)F]FDG-positive lesions (primary tumours or metastases) were included in this prospective study. The patients underwent a 10-min list-mode PET scan with a single bed position following a standard clinical whole-body [(18)F]FDG PET/CT scan. During this scan, one to three radioactive point sources (either (22)Na or (18)F, 50-100 kBq) in a dedicated holder were attached the patient's abdomen. The list mode data acquired were retrospectively analysed for respiratory signals using established data-driven gating approaches and additionally by tracking the motion of the point sources in sinogram space. Gated reconstructions were examined qualitatively, in terms of the amount of respiratory displacement and in respect of changes in local image intensity in the gated images. The presence of the external markers did not affect whole-body PET/CT image quality. Tracking of the markers led to characteristic respiratory curves in all patients. Applying these curves for gated reconstructions resulted in images in which motion was well resolved. Quantitatively, the performance of the external marker-based approach was similar to that of the best intrinsic data-driven methods. Overall, the gain in measured tumour uptake from the nongated to the gated images indicating successful removal of respiratory motion

  18. Evaluation of ambient radiation levels in positron emission tomography/computed tomography in microPET/CT laboratory

    International Nuclear Information System (INIS)

    Sarmento, Daniele Martins

    2016-01-01

    Micro PET/CT scanner is an essential tool generally used for small animal molecular imaging. Fluorine-18-labeled fluorodeoxyglucose is the most widely used radioisotope in this technique. The present study aimed to evaluate the radiation levels in a micro PET/CT research laboratory of the Radiopharmacy Center at IPEN-CNEN / SP, in order to accomplish both national standards and international recommendations. The radioprotection team has classified the laboratory as supervised area; even this laboratory does not require the adoption of specific measures for protection and safety, should be done regular re-evaluation of the conditions of occupational exposures. Workplace monitoring and individual control assessment were carried out to ensure the radiological protection of all workers directly involved in handling the scanner. Initially, there was conducted a radiometric survey, as well as measurements of the external radiation level in the workplace and its surroundings. To achieve this goal, there were placed nine thermoluminescent dosimeters of CaSO 4 :Dy in preselected locations. Monthly evaluations of the occupationally exposed individuals were carried out through the use of TL dosimeters, ported in the workers' chest. Moreover, whole body measurements were performed every six months. The study period was about two-years which started in April 2014. All tests to evaluate micro PET/CT performance were based on the standard protocol of the equipment in accordance with the standard developed by the Animal PET Standard Task Force. Present study's results demonstrated that the ambient radiation levels (ambient and effective estimated radiation dose), as well as the effective shielding equipment are both adequate. This study emphasizes that it is essential to strictly follow the principles of radioprotection in workplace, whenever researches involve radioactive unsealed sources. (author)

  19. SU-D-201-06: Random Walk Algorithm Seed Localization Parameters in Lung Positron Emission Tomography (PET) Images

    Energy Technology Data Exchange (ETDEWEB)

    Soufi, M [Shahid Beheshti University, Tehran, Tehran (Iran, Islamic Republic of); Asl, A Kamali [Shahid Beheshti University, Tehran, Iran., Tehran, Tehran (Iran, Islamic Republic of); Geramifar, P [Shariati Hospital, Tehran, Iran., Tehran, Tehran (Iran, Islamic Republic of)

    2015-06-15

    Purpose: The objective of this study was to find the best seed localization parameters in random walk algorithm application to lung tumor delineation in Positron Emission Tomography (PET) images. Methods: PET images suffer from statistical noise and therefore tumor delineation in these images is a challenging task. Random walk algorithm, a graph based image segmentation technique, has reliable image noise robustness. Also its fast computation and fast editing characteristics make it powerful for clinical purposes. We implemented the random walk algorithm using MATLAB codes. The validation and verification of the algorithm have been done by 4D-NCAT phantom with spherical lung lesions in different diameters from 20 to 90 mm (with incremental steps of 10 mm) and different tumor to background ratios of 4:1 and 8:1. STIR (Software for Tomographic Image Reconstruction) has been applied to reconstruct the phantom PET images with different pixel sizes of 2×2×2 and 4×4×4 mm{sup 3}. For seed localization, we selected pixels with different maximum Standardized Uptake Value (SUVmax) percentages, at least (70%, 80%, 90% and 100%) SUVmax for foreground seeds and up to (20% to 55%, 5% increment) SUVmax for background seeds. Also, for investigation of algorithm performance on clinical data, 19 patients with lung tumor were studied. The resulted contours from algorithm have been compared with nuclear medicine expert manual contouring as ground truth. Results: Phantom and clinical lesion segmentation have shown that the best segmentation results obtained by selecting the pixels with at least 70% SUVmax as foreground seeds and pixels up to 30% SUVmax as background seeds respectively. The mean Dice Similarity Coefficient of 94% ± 5% (83% ± 6%) and mean Hausdorff Distance of 1 (2) pixels have been obtained for phantom (clinical) study. Conclusion: The accurate results of random walk algorithm in PET image segmentation assure its application for radiation treatment planning and

  20. SU-D-201-06: Random Walk Algorithm Seed Localization Parameters in Lung Positron Emission Tomography (PET) Images

    International Nuclear Information System (INIS)

    Soufi, M; Asl, A Kamali; Geramifar, P

    2015-01-01

    Purpose: The objective of this study was to find the best seed localization parameters in random walk algorithm application to lung tumor delineation in Positron Emission Tomography (PET) images. Methods: PET images suffer from statistical noise and therefore tumor delineation in these images is a challenging task. Random walk algorithm, a graph based image segmentation technique, has reliable image noise robustness. Also its fast computation and fast editing characteristics make it powerful for clinical purposes. We implemented the random walk algorithm using MATLAB codes. The validation and verification of the algorithm have been done by 4D-NCAT phantom with spherical lung lesions in different diameters from 20 to 90 mm (with incremental steps of 10 mm) and different tumor to background ratios of 4:1 and 8:1. STIR (Software for Tomographic Image Reconstruction) has been applied to reconstruct the phantom PET images with different pixel sizes of 2×2×2 and 4×4×4 mm 3 . For seed localization, we selected pixels with different maximum Standardized Uptake Value (SUVmax) percentages, at least (70%, 80%, 90% and 100%) SUVmax for foreground seeds and up to (20% to 55%, 5% increment) SUVmax for background seeds. Also, for investigation of algorithm performance on clinical data, 19 patients with lung tumor were studied. The resulted contours from algorithm have been compared with nuclear medicine expert manual contouring as ground truth. Results: Phantom and clinical lesion segmentation have shown that the best segmentation results obtained by selecting the pixels with at least 70% SUVmax as foreground seeds and pixels up to 30% SUVmax as background seeds respectively. The mean Dice Similarity Coefficient of 94% ± 5% (83% ± 6%) and mean Hausdorff Distance of 1 (2) pixels have been obtained for phantom (clinical) study. Conclusion: The accurate results of random walk algorithm in PET image segmentation assure its application for radiation treatment planning and

  1. Brain PET scan

    Science.gov (United States)

    ... results on a PET scan. Blood sugar or insulin levels may affect the test results in people with diabetes . PET scans may be done along with a CT scan. This combination scan is called a PET/CT. Alternative Names Brain positron emission tomography; PET scan - brain References Chernecky ...

  2. Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests

    OpenAIRE

    Mustafa Demir; Türkay Toklu; Mohammad Abuqbeitah; Hüseyin Çetin; H. Sezer Sezgin; Nami Yeyin; Kerim Sönmezoğlu

    2018-01-01

    Objective: The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. Methods: According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated...

  3. Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests

    OpenAIRE

    Demir, Mustafa; Toklu, Türkay; Abuqbeitah, Mohammad; Çetin, Hüseyin; Sezgin, H. Sezer; Yeyin, Nami; Sönmezoğlu, Kerim

    2018-01-01

    Objective: The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. Methods: According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated asp...

  4. Final Report Summary: Radiation dosimetry of Cu-64-labeled radiotherapy agents using PET [Positron Emission Tomography

    International Nuclear Information System (INIS)

    Anderson, Carolyn J.; Cutler, P.D.

    2002-01-01

    This project began in 1996, and was completed in July 2001. The overall goals were to compare various methods of dosimetry of PET imaging agents, as well as develop more optimal methods. One of the major accomplishments of this grant was the human PET imaging studies of a positron-emitting radiopharmaceutical for somatostatin-receptor imaging, and subsequent dosimetry calculations resulting from this study. In addition, we collaborated with Darrell Fisher and Edmund Hui to develop a MIRD-hamster program for calculating hamster organ and tumor dosimetry in hamster models. Progress was made towards a point kernel approach to more accurately determining absorbed doses to normal organs, as well as towards co-registration of PET and MRI images. This report focuses on the progress made in the last 15 months of the grant, which in general is a summary of the progress over the 5 years the project was ongoing

  5. Co-registration of fluorescence diffuse optical tomography (fDOT) with positron emission tomography (PET) and development of multi-angle fDOT

    International Nuclear Information System (INIS)

    Tong, X.

    2012-01-01

    This thesis concerns the image processing of fluorescence diffuse optical tomography (fDOT), following two axes: fDOT image co-registration with PET (positron emission tomography) image and improvement of fDOT image reconstructions using mirrors to collect additional projections. It is presented in two parts:In the first part, an automatic method to co-register the fDOT images with PET images has been developed to correlate all the information from each modality. This co-registration method is based on automatic detection of fiducial markers (FM) present in both modalities. The particularity of this method is the use of optical surface image obtained in fDOT imaging system, which serves to identify the Z position of FM in optical images. We tested this method on a model of mice bearing tumor xenografts of MEN2A cancer cells that mimic a human medullary thyroid carcinoma, after a double injection of radiotracer [ 18 F] 2-fluoro-2-Deoxy-D-glucose (FDG) for PET imaging and optical fluorescent infrared tracer Sentidye. With the accuracy of our method, we can demonstrate that the signal of Sentidye is present both in the tumor and surrounding vessels.The fDOT reconstruction image quality is degraded along the Z axis due to a limited number of projections for reconstruction. In the second part, the work is oriented towards a new method of fDOT image reconstruction with a new multi-angle data acquisition system in placing two mirrors on each side of the animal. This work was conducted in collaboration with the CS Department of University College London (UCL), a partner of the European project FMT-XCT. TOAST software developed by this team was used as source code for the reconstruction algorithm, and was modified to adapt to the concerned problem. After several tests on the adjustment of program parameters, we applied this method on a phantom that simulating the biological tissue and on mice. The results showed an improvement in the reconstructed image of a semi

  6. Clinical value of positron emission tomography (PET) in oncology: Results of an interdisciplinary consensus conference

    International Nuclear Information System (INIS)

    Reske, S.N.; Bares, R.; Buell, U.; Guhlmann, A.; Moser, E.; Wannenmacher, M.F.

    1996-01-01

    Clinical value of PET in oncology was evaluated by a panel of recognized experts in the framework of an interdisciplinary consensus conference. On the basis of PET studies, well documented in the international literature, the value of PET for solving clinical questions was classified according to the following categories 'appropriate' (1a), 'mostly acceptable' (1b), 'helpful' (2a), 'value as yet unknown' (2b), 'useless' (3). 2-fluorodeoxyglucose (FDG) acts as the radiopharmaceutical of choice for PET in clinical oncology. PET is indicated (1a) for diagnosing relapse in high grade glioma (FDG) or low grade glioma (C-11 methionine or F-18 fluorotyrosine), differential diagnosis of solitary peripheral pulponary nodules in high risk patients and for diagnosis of pancreatic carcinoma. PET may be clinically used (1b): In 'low-grade' glioma, search for unknown primary in head and neck tumors, suspicion of relapse in nonsmall cell bronchial carcinoma (NSCBC) and colorectal carcinoma, lymphnode staging in NSCBC, pancreatic carcinoma, muscle invasive bladder carcinoma and testicular cancer. Staging of Hodgkin's disease (HD, stage I/II vs III), early therapy control in patients with a residual mass or suspicion of relapse in HD and in high grade NHL, lymph node staging and search for distant metastases in malignant melanoma (Breslow>1,5 mm), search for lymph node or distant metastases in differentiated thyroid cancer with elevated hTG and a negative radioiodide whole body scan. Many further indications are emerging, but are not yet sufficiently well documented in the literature. For most indications beside scientific studies, an individual cost benefit utility evaluation by the responsible physician is recommended. (orig./MG) [de

  7. Clinicopathological and prognostic relevance of uptake level using 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in primary breast cancer

    International Nuclear Information System (INIS)

    Ueda, Shigeto; Tsuda, Hitoshi; Asakawa, Hideki

    2008-01-01

    Using integrated 18 F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging ( 18 F-FDG PET/CT), the clinical significance of 18 F-FDG uptake was evaluated in patients with primary breast cancer. Clinicopathological correlation with the level of maximum standardized uptake values (SUV) 60 min obtained from preoperative 18 F-FDG PET/CT were examined in 152 patients with primary breast cancer. The prognostic impact of the level of SUV was explored using simulated prognosis derived from computed program Adjuvant! in 136 (89%) patients with invasive ductal carcinoma (IDC). High SUV level was significantly correlated with tumor invasive size (≤2 cm) (P 18 F-FDG would be predictive of poor prognosis in patients with primary breast cancer, and aggressive features of cancer cells in patients with early breast cancer. 18 F-FDG PET/CT could be a useful tool to pretherapeutically predict biological characteristics and baseline risk of breast cancer. (author)

  8. Heart PET scan

    Science.gov (United States)

    ... nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), ...

  9. [Diagnostic use of positron emission tomography in France: from the coincidence gamma-camera to mobile hybrid PET/CT devices].

    Science.gov (United States)

    Talbot, Jean-Noël

    2010-11-01

    Positron emission tomography (PET) is a well-established medical imaging method. PET is increasingly used for diagnostic purposes, especially in oncology. The most widely used radiopharmaceutical is FDG, a glucose analogue. Other radiopharmaceuticals have recently been registered or are in development. We outline technical improvements of PET machines during more than a decade of clinical use in France. Even though image quality has improved considerably and PET-CT hybrid machines have emerged, spending per examination has remained remarkably constant. Replacement and maintenance costs have remained in the range of 170-190 Euros per examination since 1997, whether early CDET gamma cameras or the latest time-of-flight PET/CT devices are used. This is mainly due to shorter acquisition times and more efficient use of FDG New reimbursement rates for PET/CT are needed in France in order to favor regular acquisition of state-of-the-art devices. One major development is the coupling of PET and MR imaging.

  10. Positron emission tomography (PET) study of the alterations in brain distribution of [11C]dethamphetamine in methamphetamine sensitized dog

    International Nuclear Information System (INIS)

    Mizugaki, Michinao; Nakamura, Hitoshi; Hishinuma, Takanori; Tomioka, Yoshihisa; Ishiwata, Shunji; Suzuki, Hideaki; Ido, Tatsuo; Iwata, Ren; Funaki, Yoshihito; Itoh, Masatoshi; Fujiwara, Takehiko; Yanai, Kazuhiko; Sato, Mitsumoto; Numachi, Yohtaro; Yoshida, Sumiko

    1995-01-01

    [ 11 C]Methamphetamine ([ 11 C]MAP) was synthesized by an automated on-line [ 11 C]methylation system for positron emission tomography (PET) study. We newly produced a MAP sensitized dog by repeated MAP treatment and studied the brain distribution of [ 11 C]MAP in the normal and the MAP sensitized dog. The maximal level of accumulation of [ 11 C]MAP in the sensitized dog brain was 1.4 times higher than that in the control. No difference was found in the metabolism of MAP between the two conditions. The significant increase of [ 11 C]MAP in the MAP sensitized brain indicates that subchronic MAP administration causes some functional change in uptake site of MAP

  11. Positron emission tomography (PET) study of the alterations in brain pharmacokinetics of methamphetamine in methamphetamine sensitized animals

    International Nuclear Information System (INIS)

    Nakamura, Hitoshi

    2001-01-01

    I investigated the differences in brain pharmacokinetics of [ 11 C]methamphetamine ([ 11 C]MAP) in normal and MAP sensitized animals using positron emission tomography (PET). [ 11 C]MAP was synthesized by an automated on-line [ 11 C]methylation system. I newly produced MAP sensitized dog and monkey by repeated MAP treatment. The maximal level of accumulation of [ 11 C]MAP in the sensitized dog brain was 1.4 times higher than that in the control. This result suggests the changes in the pharmacokinetic profile of MAP in the brain affect the development or expression of MAP-induced behavioral sensitization. However, the overaccumulation of [ 11 C]MAP in the sensitized monkey brain was not observed due to the influence of anesthesia. (author)

  12. Positron emission tomography (PET) study of the alterations in brain pharmacokinetics of methamphetamine in methamphetamine sensitized animals

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hitoshi [Tohoku Univ., Sendai (Japan). Hospital

    2001-08-01

    I investigated the differences in brain pharmacokinetics of [{sup 11}C]methamphetamine ([{sup 11}C]MAP) in normal and MAP sensitized animals using positron emission tomography (PET). [{sup 11}C]MAP was synthesized by an automated on-line [{sup 11}C]methylation system. I newly produced MAP sensitized dog and monkey by repeated MAP treatment. The maximal level of accumulation of [{sup 11}C]MAP in the sensitized dog brain was 1.4 times higher than that in the control. This result suggests the changes in the pharmacokinetic profile of MAP in the brain affect the development or expression of MAP-induced behavioral sensitization. However, the overaccumulation of [{sup 11}C]MAP in the sensitized monkey brain was not observed due to the influence of anesthesia. (author)

  13. On the fractal nature of dynamic positron emission tomography (PET) studies

    International Nuclear Information System (INIS)

    Dimitrakopoulou-Strauss, A.; Strauss, L.G.; Mikolajczyk, K.; Burger, C.; Lehnert, T.; Bernd, L.; Ewerbeck, V.

    2003-01-01

    Quantification of dynamic PET Studies is generally based on compartmental methods. This is a report about the implementation and assessment of a new non-compartmental method, the fractal dimension (FD), a parameter based on the box counting (BC) procedure of the chaos theory for the analysis of dynamic PET data. The evaluation included 200 malignant lesions in 159 patients with different tumour entities as well as 57 benign lesions for comparison. 101/200 malignant lesions were treated with chemotherapy, whereas 99/200 malignant lesions as well as all 57 benign lesions were untreated within the last six months prior to the PET study with F-18-Fluorodeoxyglucose (FDG). The evaluation of the FDG kinetics was performed using the BC based FD for the time-activity data. Visual assessment demonstrated generally different FDG uptake patterns in the conventional images and the parametric images of FD. FD estimates depended on the number of boxes and the maximum cut-off value used for calculation. Based on the discriminant analysis for benign and malignant lesions, FD demonstrated an accuracy of 76.65% for all patients, 67.7% for the untreated patients and 83.44% for the treated group. The use of the BC based FD is a reliable, new method for the quantification of dynamic PET studies and seems to be in particular helpful for the evaluation of treated malignant lesions. (author)

  14. Clinical blood flow measurements with O-15 water and Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Hichwa, R.D.; Watkins, G.L.; Boles Ponto, L.L.

    1993-01-01

    Traditionally PET chemists have been primarily involved in development and synthesis of radiopharmaceuticals for imaging. If greater clinical utility and research productivity are to be achieved in the PET field, then this role must be expanded to include not just the synthesis of the end product, but also the efficient and timely delivery of the radiopharmaceutical. Hence, the chemist must also consider (1) more automation of synthesis and QC procedures, (2) reduced radiopharmaceutical preparation time with emphasis towards on-line syntheses whenever feasible, (3) integrated cyclotron/chemistry operations, (4) dose delivery schemes to minimize staff exposure while maintaining purity, sterility and apyrogenicity, and (5) technologist/technician operability of all procedures. At the University of Iowa, techniques have been employed to stream-line the production synthesis, delivery, and imaging of O-15 labelled water for determination of tissue blood flow. Automated cyclotron and PET tomograph operation, as well as steady-state production of O-15 water permit a single PET technologist to conduct qualitative blood flow studies on demand for routine or emergency procedures

  15. Positron emission tomography (PET) imaging of nicotine-induced dopamine release in squirrel monkeys using [18F]Fallypride.

    Science.gov (United States)

    Naylor, Jennifer E; Hiranita, Takato; Matazel, Katelin S; Zhang, Xuan; Paule, Merle G; Goodwin, Amy K

    2017-10-01

    Nicotine, the principal psychoactive tobacco constituent, is thought to produce its reinforcing effects via actions within the mesolimbic dopamine (DA) system. The objective of the current study was to examine the effect of nicotine on DA D 2 /D 3 receptor availability in the nonhuman primate brain with the use of the radioligand [ 18 F]fallypride and positron emission tomography (PET). Ten adult male squirrel monkeys were used in the current study. Each subject underwent two PET scans, one with an injection (IV) of saline and subsequently one with an injection of nicotine (0.032mg/kg). The DA D 2 /D 3 antagonist, [ 18 F]fallypride, was delivered IV at the beginning of each scan, and nicotine or saline was delivered at 45min into the scan. Regions of interest (ROI) were drawn on specific brain regions and these were used to quantify standard uptake values (SUVs). The SUV is defined as the average concentration of radioactivity in the ROI x body weight/injected dose. Using the cerebellum as a reference region, SUV ratios (SUV ROI /SUV cerebellum ) were calculated to compare saline and nicotine effects in each ROI. Two-way repeated ANOVA revealed a significant decrease of SUV ratios in both striatal and extrastriatal regions following an injection of nicotine during the PET scans. Like other drugs of abuse, these results indicate that nicotine administration may produce DA release, as suggested by the decrease in [ 18 F]fallypride signal in striatal regions. These findings from a nonhuman primate model provide further evidence that the mesolimbic DA system is affected by the use of products that contain nicotine. Published by Elsevier B.V.

  16. Utility of 18F-fluoro-deoxyglucose emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in combination with ultrasonography for axillary staging in primary breast cancer

    International Nuclear Information System (INIS)

    Ueda, Shigeto; Ishida, Jiro; Abe, Yoshiyuki; Mochizuki, Hidetaka; Tsuda, Hitoshi; Asakawa, Hideki; Omata, Jiro; Fukatsu, Kazuhiko; Kondo, Nobuo; Kondo, Tadaharu; Hama, Yukihiro; Tamura, Katsumi

    2008-01-01

    Accurate evaluation of axillary lymph node (ALN) involvement is mandatory before treatment of primary breast cancer. The aim of this study is to compare preoperative diagnostic accuracy between positron emission tomography/computed tomography with 18 F-fluorodeoxyglucose ( 18 F-FDG PET/CT) and axillary ultrasonography (AUS) for detecting ALN metastasis in patients having operable breast cancer, and to assess the clinical management of axillary 18 F-FDG PET/CT for therapeutic indication of sentinel node biopsy (SNB) and preoperative systemic chemotherapy (PSC). One hundred eighty-three patients with primary operable breast cancer were recruited. All patients underwent 18 F-FDG PET/CT and AUS followed by SNB and/or ALN dissection (ALND). Using 18 F-FDG PET/CT, we studied both a visual assessment of 18 F-FDG uptake and standardized uptake value (SUV) for axillary staging. In a visual assessment of 18 F-FDG PET/CT, the diagnostic accuracy of ALN metastasis was 83% with 58% in sensitivity and 95% in specificity, and when cut-off point of SUV was set at 1.8, sensitivity, specificity, and accuracy were 36, 100, and 79%, respectively. On the other hand, the diagnostic accuracy of AUS was 85% with 54% in sensitivity and 99% in specificity. By the combination of 18 F-FDG PET/CT and AUS to the axilla, the sensitivity, specificity, and accuracy were 64, 94, and 85%, respectively. If either 18 F-FDG PET uptake or AUS was positive in allixa, the probability of axillary metastasis was high; 50% (6 of 12) in 18 F-FDG PET uptake only, 80% (4 of 5) in AUS positive only, and 100% (28 of 28) in dual positive. By the combination of AUS and 18 F-FDG PET/CT, candidates of SNB were more appropriately selected. The axillary 18 F-FDG uptake was correlated with the maximum size and nuclear grade of metastatic foci (p = 0.006 and p = 0.03). The diagnostic accuracy of 18 F-FDG PET/CT was shown to be nearly equal to ultrasound, and considering their limited sensitivities, the high radiation

  17. Utility of 18F-fluoro-deoxyglucose emission tomography/computed tomography fusion imaging (18F-FDG PET/CT in combination with ultrasonography for axillary staging in primary breast cancer

    Directory of Open Access Journals (Sweden)

    Tamura Katsumi

    2008-06-01

    Full Text Available Abstract Background Accurate evaluation of axillary lymph node (ALN involvement is mandatory before treatment of primary breast cancer. The aim of this study is to compare preoperative diagnostic accuracy between positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (18F-FDG PET/CT and axillary ultrasonography (AUS for detecting ALN metastasis in patients having operable breast cancer, and to assess the clinical management of axillary 18F-FDG PET/CT for therapeutic indication of sentinel node biopsy (SNB and preoperative systemic chemotherapy (PSC. Methods One hundred eighty-three patients with primary operable breast cancer were recruited. All patients underwent 18F-FDG PET/CT and AUS followed by SNB and/or ALN dissection (ALND. Using 18F-FDG PET/CT, we studied both a visual assessment of 18F-FDG uptake and standardized uptake value (SUV for axillary staging. Results In a visual assessment of 18F-FDG PET/CT, the diagnostic accuracy of ALN metastasis was 83% with 58% in sensitivity and 95% in specificity, and when cut-off point of SUV was set at 1.8, sensitivity, specificity, and accuracy were 36, 100, and 79%, respectively. On the other hand, the diagnostic accuracy of AUS was 85% with 54% in sensitivity and 99% in specificity. By the combination of 18F-FDG PET/CT and AUS to the axilla, the sensitivity, specificity, and accuracy were 64, 94, and 85%, respectively. If either 18F-FDG PET uptake or AUS was positive in allixa, the probability of axillary metastasis was high; 50% (6 of 12 in 18F-FDG PET uptake only, 80% (4 of 5 in AUS positive only, and 100% (28 of 28 in dual positive. By the combination of AUS and 18F-FDG PET/CT, candidates of SNB were more appropriately selected. The axillary 18F-FDG uptake was correlated with the maximum size and nuclear grade of metastatic foci (p = 0.006 and p = 0.03. Conclusion The diagnostic accuracy of 18F-FDG PET/CT was shown to be nearly equal to ultrasound, and considering their

  18. Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) Combined with Positron Emission Tomography-Computed Tomography (PET-CT) and Video-Electroencephalography (VEEG) Have Excellent Diagnostic Value in Preoperative Localization of Epileptic Foci in Children with Epilepsy.

    Science.gov (United States)

    Wang, Gui-Bin; Long, Wei; Li, Xiao-Dong; Xu, Guang-Yin; Lu, Ji-Xiang

    2017-01-01

    BACKGROUND To investigate the effect that dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has on surgical decision making relative to video-electroencephalography (VEEG) and positron emission tomography-computed tomography (PET-CT), and if the differences in these variables translates to differences in surgical outcomes. MATERIAL AND METHODS A total of 166 children with epilepsy undergoing preoperative DCE-MRI, VEEG, and PET-CT examinations, surgical resection of epileptic foci, and intraoperative electrocorticography (ECoG) monitoring were enrolled. All children were followed up for 12 months and grouped by Engles prognostic classification for epilepsy. Based on intraoperative ECoG as gold standard, the diagnostic values of DCE-MRI, VEEG, PET-CT, DCE-MRI combined with VEEG, DCE-MRI combined with PET-CT, and combined application of DCE-MRI, VEEG, and PET-CT in preoperative localization for epileptic foci were evaluated. RESULTS The sensitivity of DCE-MRI, VEEG, and PET-CT was 59.64%, 76.51%, and 93.98%, respectively; the accuracy of DCE-MRI, VEEG, PET-CT, DCE-MRI combined with VEEG, and DCE-MRI combined with PET-CT was 57.58%, 67.72%, 91.03%, 91.23%, and 96.49%, respectively. Localization accuracy rate of the combination of DCE-MRI, VEEG, and PET-CT was 98.25% (56/57), which was higher than that of DCE-MRI combined with VEEG and of DCE-MRI combined with PET-CT. No statistical difference was found in the accuracy rate of localization between these three combined techniques. During the 12-month follow-up, children were grouped into Engles grade I (n=106), II (n=31), III (n=21), and IV (n=8) according to postoperative conditions. CONCLUSIONS All DCE-MRI combined with VEEG, DCE-MRI combined with PET-CT, and DCE-MRI combined with VEEG and PET-CT examinations have excellent accuracy in preoperative localization of epileptic foci and present excellent postoperative efficiency, suggesting that these combined imaging methods are suitable for serving as the

  19. Water-equivalent oral contrast agents in dual-modality PET/computed tomography scanning: does a little barium make the difference?

    Science.gov (United States)

    Kinner, Sonja; Veit-Haibach, Patrick; Lauenstein, Thomas C; Bockisch, Andreas; Antoch, Gerald

    2009-03-01

    To retrospectively evaluate the performance of two water-equivalent oral contrast agents [locust bean gum (LBG)-mannitol and VoLumen] concerning their potential to distend the bowel while avoiding contrast-associated artifacts in PET/computed tomography. PET/computed tomography examinations of 30 patients with two different oral contrast agents were reviewed. Bowel distension, intraluminal density, and potential contrast-associated artifacts were assessed for stomach, jejunum, and ileum. Statistical significance was tested by Student's t-test. Distension was slightly better in the stomach with VoLumen as compared with LBG-mannitol whereas LBG-mannitol was found to slightly better distend the small bowel. This difference proved to be statistically significant for the jejunum. A statistically significant difference was detected for intraluminal density with higher densities for VoLumen. This difference, however, did not result in a higher incidence of PET artifacts with VoLumen. LBG-mannitol provides excellent bowel distension, thereby avoiding contrast-associated PET artifacts. If this solution is not available, VoLumen provides a satisfactory alternative for bowel distension without relevant PET artifacts.

  20. Brain activation during dichotic presentations of consonant-vowel and musical instrument stimuli: a 15O-PET study.

    Science.gov (United States)

    Hugdahl, K; Brønnick, K; Kyllingsbaek, S; Law, I; Gade, A; Paulson, O B

    1999-04-01

    Dichotic listening means that two different stimuli are presented at the same time, one in each ear. This technique is frequently used in experimental and clinical studies as a measure of hemispheric specialization. The primary aim of the present study was to record regional changes in the distribution of cerebral blood flow (CBF) with the 15O-PET technique to dichotically presented consonant-vowel (CV) and musical instrument stimuli, in order to test the basic assumption of differential hemispheric involvement when stimuli presented to one ear dominate over stimuli presented in the other ear. All stimuli were 380 ms in duration with a 1000 ms interstimulus interval, and were presented in blocks of either CV-syllable or musical instrument pairs. Twelve normal healthy subjects had to press a button whenever they detected a CV-syllable or a musical instrument target in a stream of CV- and musical instrument distractor stimuli. The targets appeared equally often in the right and left ear channel. The CV-syllable and musical instrument targets activated bilateral areas in the superior temporal gyri. However, there were significant interactions with regard to asymmetry of the magnitude of peak activation in the significant activation clusters. The CV-syllables resulted in greater neural activation in the left temporal lobe while the musical instruments resulted in greater neural activation in the right temporal lobe. Within-subjects correlations between magnitude of dichotic listening and CBF asymmetry were, however, non-significant. The changes in neural activation were closely mimicked by the performance data which showed a right ear superiority in response accuracy for the CV-syllables, and a left ear superiority for the musical instruments. In addition to the temporal lobe activations, there were activation tendencies in the left inferior frontal lobe, right dorsolateral prefrontal cortex, left occipital lobe, and cerebellum.

  1. HIV infection and arterial inflammation assessed by (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)

    DEFF Research Database (Denmark)

    Knudsen, Andreas; Hag, Anne Mette Fisker; Loft, Annika

    2015-01-01

    BACKGROUND: HIV-infected patients are at increased risk of myocardial infarction and arterial inflammation has been suggested as a pathophysiological explanation. We compared the uptake of 18F-fluorodeoxyglucose (FDG) by PET in four arterial regions, and factors associated with FDG uptake in well......-treated HIV-infected patients without cardiovascular disease (CVD) and healthy controls. METHODS AND RESULTS: We prospectively scanned 26 HIV-infected patients on stable antiretroviral therapy and 25 healthy volunteers with FDG PET/CT, measuring standardized uptake values (SUV) in the carotid arteries......, the ascending, descending, and abdominal aorta. We performed correlation analyses between FDG uptake and intima-media thickness (IMT), and soluble biomarkers of inflammation. We found no difference in arterial FDG uptake between the HIV-infected patients and healthy controls quantified either as mean SUVmax...

  2. Nanosurveyor 2: A Compact Instrument for Nano-Tomography at the Advanced Light Source

    Science.gov (United States)

    Celestre, Richard; Nowrouzi, Kasra; Shapiro, David A.; Denes, Peter; Joseph, John M.; Schmid, Andreas; Padmore, Howard A.

    2017-06-01

    The Advanced Light Source has developed a compact tomographic microscope based on soft x-ray ptychography for the study of nanoscale materials [1,2]. The microscope utilizes the sample manipulator mechanism from a commercial TEM coupled with laser interferometric feedback for zone plate positioning and a fast frame rate charge-coupled device detector for soft x-ray diffraction measurements. The microscope has achieved point to point (25 nm steps) scan rates of greater than 120 Hz with a positioning accuracy of better than 1 nm RMS. The instrument will enable the use of commercially available sample holders compatible with FEI transmission electron microscopes thus also allowing in-situ measurement of samples using both soft x-rays and electrons. This instrument is a refinement of a currently commissioned instrument called The Nanosurveyor, which has demonstrated resolution of better than 10 nm in two dimensions using 750 eV x-rays. Once moved to the new Coherent Scattering and Microscopy beamline it will enable spectromicroscopy and tomography of nano-materials with wavelength limited spatial resolution.

  3. Instrumentation

    International Nuclear Information System (INIS)

    Muehllehner, G.; Colsher, J.G.

    1982-01-01

    This chapter reviews the parameters which are important to positron-imaging instruments. It summarizes the options which various groups have explored in designing tomographs and the methods which have been developed to overcome some of the limitations inherent in the technique as well as in present instruments. The chapter is not presented as a defense of positron imaging versus single-photon or other imaging modality, neither does it contain a description of various existing instruments, but rather stresses their common properties and problems. Design parameters which are considered are resolution, sampling requirements, sensitivity, methods of eliminating scattered radiation, random coincidences and attenuation. The implementation of these parameters is considered, with special reference to sampling, choice of detector material, detector ring diameter and shielding and variations in point spread function. Quantitation problems discussed are normalization, and attenuation and random corrections. Present developments mentioned are noise reduction through time-of-flight-assisted tomography and signal to noise improvements through high intrinsic resolution. Extensive bibliography. (U.K.)

  4. Paul Lecoq assembles a read head made with special crystals for a PET (positron emission tomography) scanner. He is the initiator of the Crystal Clear collaboration, which aims to transfer crystals developed at CERN to applications in medical imaging.

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    Paul Lecoq assembles a read head made with special crystals for a PET (positron emission tomography) scanner. He is the initiator of the Crystal Clear collaboration, which aims to transfer crystals developed at CERN to applications in medical imaging.

  5. Computed tomography of thoracic and lumbar spine fractures that have been treated with Harrington instrumentation

    International Nuclear Information System (INIS)

    Golimbu, C.; Firooznia, H.; Rafii, M.; Engler, G.; Delman, A.

    1984-01-01

    Twenty patients with fractures of the thoracic and lumbar spine underwent computed tomography (CT) following Harrington distraction instrumentation and a spinal fusion. CT was done to search for a cause of persistent cord or nerve root compression in those patients who failed to improve and completely recover their partial neurologic deficit (14 cases). The most common abnormality was the presence of residual bone fragments originating in the burst fracture of a vertebral body displaced posteriorly, into the spinal canal. In patients with complications in the late recovery period, CT found exuberant callus indenting the canal or lack of fusion of the bone grafts placed in the anterolateral aspect of the vertebral bodies. This experience indicates that CT is the modality of choice for spinal canal evaluation in those patients who fail to have an optimal clinical course following fractures of the thoracic and lumbar spine treated with Harrington rods

  6. WholeBbody Positron-Emission-Tomography (WB-PET) in oncology

    International Nuclear Information System (INIS)

    Feine, U.; Lietzenmayer, R.; Mueller-Schauenburg, W.; Geiger, L.; Hanke, J.P.; Weisser, G.; Woehrle, H.

    1996-01-01

    The new generation of high sensitive PET-Scanners with an FOV of about 15 cm allows to recognize with high sensitivity and good spezificity malign tumors and their metastases with 18F-FDG in a Whole-Body-Scan in 35 to 50 min scan time. 357 FDG-WB-PET-Scans have been performed in Tuebingen during 1 1/2 years since January 1994 in tumor patients and have been compared and evaluated to the results of other imaging methods performed in the same time together with clinics and in follow-up. In 4 groups of tumors - Melanoma - malign Lymphoma -Breast Cancer - Thyroid Cancer - and a fifth group of 24 various types of malign tumors we found a sensitivity of 88%, a specificity of 80% and an accuracy of 90%. Foci smaller than 6-8 mm diametre - mostly lung metastases or lymphomas - and also tumors of low malignancy such as 131l-trapping Tyroid Carcinomas and Ganglioneuroblastomas have been found false negative. Flase positive we found inflammated lymph nodes, abscesses and also benign thyroid adenomas. This high sensitivity makes 18F-FDG-WB-PET an important method for tumor searching and diagnosis of tumor spreading, esp. for primary and secondary staging in the future, but also as the unique imaging method which allows determination of resting tumor vitality after therapy. Further multi-center studies will be necessary before this method can be introduced to routine, that also is limited by the high costs of the procedure. (orig.) [de

  7. (18)F-Fluorodeoxyglucose PET/Computed Tomography for Primary Brain Tumors

    DEFF Research Database (Denmark)

    Antonsen Segtnan, Eivind; Hess, Søren; Grupe, Peter

    2015-01-01

    Structural imaging with computed tomography (CT) and MR imaging is the mainstay in primary diagnosis of primary brain tumors, but these modalities depend on morphologic appearance and an intact blood-brain barrier, and important aspects of tumor biology are not addressed. Such issues may...

  8. Laboratory Scale X-ray Fluorescence Tomography: Instrument Characterization and Application in Earth and Environmental Science.

    Science.gov (United States)

    Laforce, Brecht; Vermeulen, Bram; Garrevoet, Jan; Vekemans, Bart; Van Hoorebeke, Luc; Janssen, Colin; Vincze, Laszlo

    2016-03-15

    A new laboratory scale X-ray fluorescence (XRF) imaging instrument, based on an X-ray microfocus tube equipped with a monocapillary optic, has been developed to perform XRF computed tomography experiments with both higher spatial resolution (20 μm) and a better energy resolution (130 eV @Mn-K(α)) than has been achieved up-to-now. This instrument opens a new range of possible applications for XRF-CT. Next to the analytical characterization of the setup by using well-defined model/reference samples, demonstrating its capabilities for tomographic imaging, the XRF-CT microprobe has been used to image the interior of an ecotoxicological model organism, Americamysis bahia. This had been exposed to elevated metal (Cu and Ni) concentrations. The technique allowed the visualization of the accumulation sites of copper, clearly indicating the affected organs, i.e. either the gastric system or the hepatopancreas. As another illustrative application, the scanner has been employed to investigate goethite spherules from the Cretaceous-Paleogene boundary, revealing the internal elemental distribution of these valuable distal ejecta layer particles.

  9. Positron Emission Tomography (PET Quantification of GABAA Receptors in the Brain of Fragile X Patients.

    Directory of Open Access Journals (Sweden)

    Charlotte D'Hulst

    Full Text Available Over the last several years, evidence has accumulated that the GABAA receptor is compromised in animal models for fragile X syndrome (FXS, a common hereditary form of intellectual disability. In mouse and fly models, agonists of the GABAA receptor were able to rescue specific consequences of the fragile X mutation. Here, we imaged and quantified GABAA receptors in vivo in brain of fragile X patients using Positron Emission Topography (PET and [11C]flumazenil, a known high-affinity and specific ligand for the benzodiazepine site of GABAA receptors. We measured regional GABAA receptor availability in 10 fragile X patients and 10 control subjects. We found a significant reduction of on average 10% in GABAA receptor binding potential throughout the brain in fragile X patients. In the thalamus, the brain region showing the largest difference, the GABAA receptor availability was even reduced with 17%. This is one of the first reports of a PET study of human fragile X brain and directly demonstrates that the GABAA receptor availability is reduced in fragile X patients. The study reinforces previous hypotheses that the GABAA receptor is a potential target for rational pharmacological treatment of fragile X syndrome.

  10. [Correlation of auditory-verbal skills in patients with cochlear implants and their evaluation in positone emission tomography (PET)].

    Science.gov (United States)

    Łukaszewicz, Zuzanna; Soluch, Paweł; Niemczyk, Kazimierz; Lachowska, Magdalena

    2010-06-01

    An assumption was taken that in central nervous system (CNS) in patients above 15 years of age there are possible mechanisms of neuronal changes. Those changes allow for reconstruction or formation of natural activation pattern of appropriate brain structures responsible for auditory speech processing. The aim of the study was to observe if there are any dynamic functional changes in central nervous system and their correlation to the auditory-verbal skills of the patients. Nine right-handed patients between 15 and 36 years of age were examined, 6 females and 3 males. All of them were treated with cochlear implantation and are in frequent follow-up in the Department of Otolaryngology at the Medical University of Warsaw due to profound sensorineural hearing loss. In present study the patients were examined within 24 hours after the first fitting of the speech processor of the cochlear implant, and 1 and 2 years subsequently. Combination of performed examinations consisted of: positone emission tomography of the brain, and audiological tests including speech assessment. In the group of patients 4 were postlingually deaf, and 5 were prelinqually deaf. Postlingually deaf patients achieved great improvement of hearing and speech understanding. In their first PET examination very intensive activation of visual cortex V1 and V2 (BA17 and 18) was observed. There was no significant activation in the dominant (left) hemisphere of the brain. In PET examination performed 1 and 2 years after the cochlear implantation no more V1 and V2 activation region was observed. Instead particular regions of the left hemisphere got activated. In prelingually deaf patients no significant changes in central nervous system were noticeable neither in PET nor in speech assessment, although their hearing possibilities improved. Positive correlation was observed between the level of speech understanding, linguistic skills and the activation of appropriate areas of the left hemisphere of the brain

  11. Passive Tomography for Spent Fuel Verification: Analysis Framework and Instrument Design Study

    Energy Technology Data Exchange (ETDEWEB)

    White, Timothy A.; Svard, Staffan J.; Smith, Leon E.; Mozin, Vladimir V.; Jansson, Peter; Davour, Anna; Grape, Sophie; Trellue, H.; Deshmukh, Nikhil S.; Wittman, Richard S.; Honkamaa, Tapani; Vaccaro, Stefano; Ely, James

    2015-05-18

    The potential for gamma emission tomography (GET) to detect partial defects within a spent nuclear fuel assembly is being assessed through a collaboration of Support Programs to the International Atomic Energy Agency (IAEA). In the first phase of this study, two safeguards verification objectives have been identified. The first is the independent determination of the number of active pins that are present in the assembly, in the absence of a priori information. The second objective is to provide quantitative measures of pin-by-pin properties, e.g. activity of key isotopes or pin attributes such as cooling time and relative burnup, for the detection of anomalies and/or verification of operator-declared data. The efficacy of GET to meet these two verification objectives will be evaluated across a range of fuel types, burnups, and cooling times, and with a target interrogation time of less than 60 minutes. The evaluation of GET viability for safeguards applications is founded on a modelling and analysis framework applied to existing and emerging GET instrument designs. Monte Carlo models of different fuel types are used to produce simulated tomographer responses to large populations of “virtual” fuel assemblies. Instrument response data are processed by a variety of tomographic-reconstruction and image-processing methods, and scoring metrics specific to each of the verification objectives are defined and used to evaluate the performance of the methods. This paper will provide a description of the analysis framework and evaluation metrics, example performance-prediction results, and describe the design of a “universal” GET instrument intended to support the full range of verification scenarios envisioned by the IAEA.

  12. False-positive uptake on 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) positron-emission tomography/computed tomography (PET/CT) in oncological imaging

    International Nuclear Information System (INIS)

    Culverwell, A.D.; Scarsbrook, A.F.; Chowdhury, F.U.

    2011-01-01

    With the increasing utilization of integrated positron-emission tomography/computed tomography (PET/CT) using the glucose analogue 2-[ 18 F]-fluoro-2-deoxy-D-glucose (FDG) in oncological imaging, it is important for radiologists and nuclear medicine physicians to be aware that FDG uptake is not specific for malignancy, as many different physiological variants and benign pathological conditions can also exhibit increased glucose metabolism. Such false-positive FDG uptake often arises outside the area of primary interest and may mimic malignant disease, thereby confounding accurate interpretation of PET/CT studies. With the use of illustrative clinical cases, this article will provide a systematic overview of potential interpretative pitfalls and illustrate how such unexpected findings can be appropriately evaluated.

  13. Chronic contained rupture of abdominal aortic aneurysm (CCR-AAA) with massive vertebral bone erosion: computed tomography (CT), magnetic resonance imaging (MRI) and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) findings.

    Science.gov (United States)

    Nakano, Sachiko; Okauchi, Kenzo; Tsushima, Yoshito

    2014-02-01

    A 62-year-old male presented with sudden onset of low back and right leg pain. Contrast-enhanced computed tomography demonstrated an abdominal aortic aneurysm (AAA), along with a large mass lesion causing vertebral body erosion. Magnetic resonance imaging (MRI) suggested that the mass lesion consisted of a chronic hematoma. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) demonstrated increased uptake around the mass lesion, but not around the AAA. Surgical intervention was performed, and the subsequent histological diagnosis was chronic contained rupture of AAA. The mass lesion consisted of chronic hematoma and necrosis with inflammatory cell infiltration and hemosiderin deposition. This condition mimics some neoplastic diseases, but MRI and FDG-PET findings may help establish the correct diagnosis.

  14. Chronic contained rupture of abdominal aortic aneurysm (CCR-AAA) with massive vertebral bone erosion. Computed tomography (CT), magnetic resonance imaging (MRI) and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) findings

    International Nuclear Information System (INIS)

    Nakano, Sachiko; Okauchi, Kenzo; Tsushima, Yoshito

    2014-01-01

    A 62-year-old male presented with sudden onset of low back and right leg pain. Contrast-enhanced computed tomography demonstrated an abdominal aortic aneurysm (AAA), along with a large mass lesion causing vertebral body erosion. Magnetic resonance imaging (MRI) suggested that the mass lesion consisted of a chronic hematoma. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) demonstrated increased uptake around the mass lesion, but not around the AAA. Surgical intervention was performed, and the subsequent histological diagnosis was chronic contained rupture of AAA. The mass lesion consisted of chronic hematoma and necrosis with inflammatory cell infiltration and hemosiderin deposition. This condition mimics some neoplastic diseases, but MRI and FDG-PET findings may help establish the correct diagnosis. (author)

  15. Tomography of positrons with SPECT systems

    International Nuclear Information System (INIS)

    Isoardi, Roberto A.

    1999-01-01

    The tomography for emissions of positrons (PET) demonstrate the clinical uses to provide information in the area of neurology, cardiology and principally, in oncology. This chapter describes the principles of the functioning and instrumentation, clinical applications and the state of the art

  16. Mathematical modeling of positron emission tomography (PET) data to assess radiofluoride transport in living plants following petiolar administration.

    Science.gov (United States)

    Converse, Alexander K; Ahlers, Elizabeth O; Bryan, Tom W; Hetue, Jackson D; Lake, Katherine A; Ellison, Paul A; Engle, Jonathan W; Barnhart, Todd E; Nickles, Robert J; Williams, Paul H; DeJesus, Onofre T

    2015-01-01

    Ion transport is a fundamental physiological process that can be studied non-invasively in living plants with radiotracer imaging methods. Fluoride is a known phytotoxic pollutant and understanding its transport in plants after leaf absorption is of interest to those in agricultural areas near industrial sources of airborne fluoride. Here we report the novel use of a commercial, high-resolution, animal positron emission tomography (PET) scanner to trace a bolus of [(18)F]fluoride administered via bisected petioles of Brassica oleracea, an established model species, to simulate whole plant uptake of atmospheric fluoride. This methodology allows for the first time mathematical compartmental modeling of fluoride transport in the living plant. Radiotracer kinetics in the stem were described with a single-parameter free- and trapped-compartment model and mean arrival times at different stem positions were calculated from the free-compartment time-activity curves. After initiation of administration at the bisected leaf stalk, [(18)F] radioactivity climbed for approximately 10 minutes followed by rapid washout from the stem and equilibration within leaves. Kinetic modeling of transport in the stem yielded a trapping rate of 1.5 +/- 0.3%/min (mean +/- s.d., n = 3), velocity of 2.2 +/- 1.1 cm/min, and trapping fraction of 0.8 +/- 0.5%/cm. Quantitative assessment of physiologically meaningful transport parameters of fluoride in living plants is possible using standard positron emission tomography in combination with petiolar radiotracer administration. Movement of free fluoride was observed to be consistent with bulk flow in xylem, namely a rapid and linear change in position with respect to time. Trapping, likely in the apoplast, was observed. Future applications of the methods described here include studies of transport of other ions and molecules of interest in plant physiology.

  17. Poster – 02: Positron Emission Tomography (PET) Imaging Reconstruction using higher order Scattered Photon Coincidences

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hongwei; Pistorius, Stephen [Department of Physics and Astronomy, University of Manitoba, CancerCare, Manitoba (Canada)

    2016-08-15

    PET images are affected by the presence of scattered photons. Incorrect scatter-correction may cause artifacts, particularly in 3D PET systems. Current scatter reconstruction methods do not distinguish between single and higher order scattered photons. A dual-scattered reconstruction method (GDS-MLEM) that is independent of the number of Compton scattering interactions and less sensitive to the need for high energy resolution detectors, is proposed. To avoid overcorrecting for scattered coincidences, the attenuation coefficient was calculated by integrating the differential Klein-Nishina cross-section over a restricted energy range, accounting only for scattered photons that were not detected. The optimum image can be selected by choosing an energy threshold which is the upper energy limit for the calculation of the cross-section and the lower limit for scattered photons in the reconstruction. Data was simulated using the GATE platform. 500,000 multiple scattered photon coincidences with perfect energy resolution were reconstructed using various methods. The GDS-MLEM algorithm had the highest confidence (98%) in locating the annihilation position and was capable of reconstructing the two largest hot regions. 100,000 photon coincidences, with a scatter fraction of 40%, were used to test the energy resolution dependence of different algorithms. With a 350–650 keV energy window and the restricted attenuation correction model, the GDS-MLEM algorithm was able to improve contrast recovery and reduce the noise by 7.56%–13.24% and 12.4%–24.03%, respectively. This approach is less sensitive to the energy resolution and shows promise if detector energy resolutions of 12% can be achieved.

  18. Synthesis and evaluation of translocator 18 kDa protein (TSPO) positron emission tomography (PET) radioligands with low binding sensitivity to human single nucleotide polymorphism rs6971.

    Science.gov (United States)

    Zanotti-Fregonara, Paolo; Zhang, Yi; Jenko, Kimberly J; Gladding, Robert L; Zoghbi, Sami S; Fujita, Masahiro; Sbardella, Gianluca; Castellano, Sabrina; Taliani, Sabrina; Martini, Claudia; Innis, Robert B; Da Settimo, Federico; Pike, Victor W

    2014-10-15

    The imaging of translocator 18 kDa protein (TSPO) in living human brain with radioligands by positron emission tomography (PET) has become an important means for the study of neuroinflammatory conditions occurring in several neuropsychiatric disorders. The widely used prototypical PET radioligand [(11)C](R)-PK 11195 ([(11)C](R)-1; [N-methyl-(11)C](R)-N-sec-butyl-1-(2-chlorophenyl)-N-methylisoquinoline-3-carboxamide) gives a low PET signal and is difficult to quantify, whereas later generation radioligands have binding sensitivity to a human single nucleotide polymorphism (SNP) rs6971, which imposes limitations on their utility for comparative quantitative PET studies of normal and diseased subjects. Recently, azaisosteres of 1 have been developed with improved drug-like properties, including enhanced TSPO affinity accompanied by moderated lipophilicity. Here we selected three of these new ligands (7-9) for labeling with carbon-11 and for evaluation in monkey as candidate PET radioligands for imaging brain TSPO. Each radioligand was readily prepared by (11)C-methylation of an N-desmethyl precursor and was found to give a high proportion of TSPO-specific binding in monkey brain. One of these radioligands, [(11)C]7, the direct 4-azaisostere of 1, presents many radioligand properties that are superior to those reported for [(11)C]1, including higher affinity, lower lipophilicity, and stable quantifiable PET signal. Importantly, 7 was also found to show very low sensitivity to the human SNP rs6971 in vitro. Therefore, [(11)C]7 now warrants evaluation in human subjects with PET to assess its utility for imaging TSPO in human brain, irrespective of subject genotype.

  19. Cyclotron/PET project in Uruguay

    International Nuclear Information System (INIS)

    Engler, H.

    2006-01-01

    The Positron Computed Tomography (PET) is a tri dimensional image technique which shows biochemical information. PET is used in neurology and cardiology diseases. The National Center Cyclotron PET has been found to research, development and health science applications.

  20. PET/CT (and CT) instrumentation, image reconstruction and data transfer for radiotherapy planning

    DEFF Research Database (Denmark)

    Sattler, Bernhard; Lee, John A; Lonsdale, Markus

    2010-01-01

    -invasive imaging technique, offers the visualization and quantification of pre-selected tracer metabolism. In combination with the structural information from CT, this molecular imaging technique has great potential to support and improve the outcome of the treatment-planning procedure prior to radiotherapy......, the DICOM-Standard provides objects and classes for this purpose (DICOM RT). Furthermore, the standard DICOM objects and classes for nuclear medicine (NM, PT) and computed tomography (CT) are used to communicate the actual image data created by the modalities. Care must be taken for data security...

  1. Use of PET Images in Assessment of Brain Absorbed Dose of Patients Undergoing [C-11] Raclopride Positron Emission Tomography

    International Nuclear Information System (INIS)

    Park, Jong O

    2005-08-01

    The positron emission tomography (PET) in combination with [C-11] raclopride is commonly used for early detection of the Parkinson's disease. Injection of considerable amount of radioactivity, typically 300∼500 MBq of [C-11] at a time, for the examination calls for attention to doses to tissues of the patient, particularly to the brain. Since [C-11] raclopride is not a common radiopharmaceutical, dosimetric data for internal dose evaluation are rare yet. In this study, an attempt was made to determine doses to the brain and the striatum of patients by use of the PET images obtained for the clinical purposes. Four informed patients suffering Parkinson's disease participated in this study. Time series of 18 frames, 35 slices in each frame, of PET images of the head were obtained. By transforming the pixel intensity in the assigned region of interests into radioactivity contents, the retention curves were constructed to evaluate the residence times. Absorbed doses to the target tissues were calculated by applying the S-values given in the MIRDOSE3.1 code. The resulting dose coefficients for the whole brain and the striatum were 0.0110±0.0016 mGy/MBq and 0.0664±0.0238 mGy/MBq, respectively. The brain dose coefficient is considerably higher than the corresponding values in other studies employing healthy subjects. This may be attributed to probable enhanced capture of [C-11] raclopride by the dopamine D 2 receptors in case of subjects with Parkinson's disease. The transcrianial magnetic stimulation (TMS) procedures are often used in treatment of Parkinson's disease. If the procedure stimulates secretion of dopamine, less retention of [C-11] raclopride is expected due to competition. So the similar assessments were made for the same patients after TMS treatments. Disappointingly, the ratios of residence time without TMS to that with TMS were 0.943±0.074 and 0.98±0.14 for the brain and the striatum, respectively. For the striatum, the ratios for three patients were

  2. Applications of nucleoside-based molecular probes for the in vivo assessment of tumour biochemistry using positron emission tomography (PET

    Directory of Open Access Journals (Sweden)

    Leonard I. Wiebe

    2007-05-01

    Full Text Available Positron emission tomography (PET is a non-invasive nuclear imaging technique. In PET, radiolabelled molecules decay by positron emission. The gamma rays resulting from positron annihilation are detected in coincidence and mapped to produce three dimensional images of radiotracer distribution in the body. Molecular imaging with PET refers to the use of positron-emitting biomolecules that are highly specific substrates for target enzymes, transport proteins or receptor proteins. Molecular imaging with PET produces spatial and temporal maps of the target-related processes. Molecular imaging is an important analytical tool in diagnostic medical imaging, therapy monitoring and the development of new drugs. Molecular imaging has its roots in molecular biology. Originally, molecular biology meant the biology of gene expression, but now molecular biology broadly encompasses the macromolecular biology and biochemistry of proteins, complex carbohydrates and nucleic acids. To date, molecular imaging has focused primarily on proteins, with emphasis on monoclonal antibodies and their derivative forms, small-molecule enzyme substrates and components of cell membranes, including transporters and transmembrane signalling elements. This overview provides an introduction to nucleosides, nucleotides and nucleic acids in the context of molecular imaging.A tomografia por emissão de pósitrons (TEP é uma técnica de imagem não invasiva da medicina nuclear. A TEP utiliza moléculas marcadas com emissores de radiação beta positiva (pósitrons. As radiações gama medidas que resultam do aniquilamento dos pósitrons são detectadas por um sistema de coincidência e mapeadas para produzir uma imagem tridimensional da distribuição do radiotraçador no corpo. A imagem molecular com TEP refere-se ao uso de biomoléculas marcadas com emissor de pósitron que são substratos altamente específicos para alvos como enzimas, proteínas transportadoras ou receptores prot

  3. [Principles of PET].

    Science.gov (United States)

    Beuthien-Baumann, B

    2018-05-01

    Positron emission tomography (PET) is a procedure in nuclear medicine, which is applied predominantly in oncological diagnostics. In the form of modern hybrid machines, such as PET computed tomography (PET/CT) and PET magnetic resonance imaging (PET/MRI) it has found wide acceptance and availability. The PET procedure is more than just another imaging technique, but a functional method with the capability for quantification in addition to the distribution pattern of the radiopharmaceutical, the results of which are used for therapeutic decisions. A profound knowledge of the principles of PET including the correct indications, patient preparation, and possible artifacts is mandatory for the correct interpretation of PET results.

  4. Time-of-flight positron emission tomography (T.O.F. P.E.T.)

    International Nuclear Information System (INIS)

    Allemand, R.

    1984-10-01

    A new important step has been made in the performances of the time-of-flight positron imaging for the two last years. It has been proved that a high spatial resolution can be obtained with the T.O.F. technique. It has also been shown that the overall sensitivity (taking into account the sensitivity gain and BaF2 detection characteristics) is quite close to the one of conventional methods. On the other hand, the basic advantages related to the high counting rate capability, the random coincidences rejection etc... of course remain. It is probably safe to assume that significant improvements can be expected if new technological efforts are invested. Unfortunately, P.E.T. is a complex and expensive tool which has been only used up to now in the research groups (about 50 centers in the world). The justification of new technical developments will be quite clear when this modality will be considered in the assessment of diseases and in clinical diagnostic applications

  5. Agreement of Two Different Spectral Domain Optical Coherence Tomography Instruments for Retinal Nerve Fiber Layer Measurements

    Directory of Open Access Journals (Sweden)

    Hooshang Faghihi

    2014-01-01

    Full Text Available Purpose: To determine the agreement between Spectralis and Cirrus spectral domain optical coherence tomography (SD-OCT measurements of peripapillary retinal nerve fiber layer (RNFL thickness. Methods: Suspected or confirmed cases of glaucoma who met the inclusion criteria underwent peripapillary RNFL thickness measurement using both the Spectralis and Cirrus on the same day within a few minutes. Results: Measurements were performed on 103 eyes of 103 patients with mean age of 50.4±17.7 years. Mean RNFL thickness was 89.22±15.87 versus 84.54±13.68 μm using Spectralis and Cirrus, respectively. The difference between measurements and the average of paired measurements with the two devices showed a significant linear relationship. Bland-Altman plots demonstrated that Spectralis thickness values were systematically larger than that of Cirrus. Conclusion: Spectralis OCT generates higher peripapillary RNFL thickness readings as compared to Cirrus OCT; this should be kept in mind when values obtained with different instruments are compared during follow-up.

  6. Attenuation Correction Strategies for Positron Emission Tomography/Computed Tomography and 4-Dimensional Positron Emission Tomography/Computed Tomography

    OpenAIRE

    Pan, Tinsu; Zaidi, Habib

    2013-01-01

    This article discusses attenuation correction strategies in positron emission tomography/computed tomography (PET/CT) and 4 dimensional PET/CT imaging. Average CT scan derived from averaging the high temporal resolution CT images is effective in improving the registration of the CT and the PET images and quantification of the PET data. It underscores list mode data acquisition in 4 dimensional PET and introduces 4 dimensional CT popular in thoracic treatment planning to 4 dimensional PET/CT. ...

  7. Compressive sensing of signals generated in plastic scintillators in a novel J-PET instrument

    International Nuclear Information System (INIS)

    Raczyński, L.; Moskal, P.; Kowalski, P.; Wiślicki, W.; Bednarski, T.; Białas, P.; Czerwiński, E.; Gajos, A.; Kapłon, Ł.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kozik, T.; Krzemień, W.; Kubicz, E.; Niedźwiecki, Sz.; Pałka, M.; Rudy, Z.; Rundel, O.; Salabura, P.

    2015-01-01

    The J-PET scanner, which allows for single bed imaging of the whole human body, is currently under development at the Jagiellonian University. The discussed detector offers improvement of the Time of Flight (TOF) resolution due to the use of fast plastic scintillators and dedicated electronics allowing for sampling in the voltage domain of signals with durations of few nanoseconds. In this paper we show that recovery of the whole signal, based on only a few samples, is possible. In order to do that, we incorporate the training signals into the Tikhonov regularization framework and we perform the Principal Component Analysis decomposition, which is well known for its compaction properties. The method yields a simple closed form analytical solution that does not require iterative processing. Moreover, from the Bayes theory the properties of regularized solution, especially its covariance matrix, may be easily derived. This is the key to introduce and prove the formula for calculations of the signal recovery error. In this paper we show that an average recovery error is approximately inversely proportional to the number of acquired samples

  8. Compressive sensing of signals generated in plastic scintillators in a novel J-PET instrument

    Energy Technology Data Exchange (ETDEWEB)

    Raczyński, L., E-mail: lech.raczynski@ncbj.gov.pl [Świerk Computing Centre, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Moskal, P. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-059 Cracow (Poland); Kowalski, P.; Wiślicki, W. [Świerk Computing Centre, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Bednarski, T.; Białas, P.; Czerwiński, E.; Gajos, A. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-059 Cracow (Poland); Kapłon, Ł. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-059 Cracow (Poland); Institute of Metallurgy and Materials Science of Polish Academy of Sciences, Cracow (Poland); Kochanowski, A. [Faculty of Chemistry, Jagiellonian University, 30-060 Cracow (Poland); Korcyl, G.; Kowal, J.; Kozik, T.; Krzemień, W.; Kubicz, E.; Niedźwiecki, Sz.; Pałka, M.; Rudy, Z.; Rundel, O.; Salabura, P. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-059 Cracow (Poland); and others

    2015-06-21

    The J-PET scanner, which allows for single bed imaging of the whole human body, is currently under development at the Jagiellonian University. The discussed detector offers improvement of the Time of Flight (TOF) resolution due to the use of fast plastic scintillators and dedicated electronics allowing for sampling in the voltage domain of signals with durations of few nanoseconds. In this paper we show that recovery of the whole signal, based on only a few samples, is possible. In order to do that, we incorporate the training signals into the Tikhonov regularization framework and we perform the Principal Component Analysis decomposition, which is well known for its compaction properties. The method yields a simple closed form analytical solution that does not require iterative processing. Moreover, from the Bayes theory the properties of regularized solution, especially its covariance matrix, may be easily derived. This is the key to introduce and prove the formula for calculations of the signal recovery error. In this paper we show that an average recovery error is approximately inversely proportional to the number of acquired samples.

  9. Compressive sensing of signals generated in plastic scintillators in a novel J-PET instrument

    Science.gov (United States)

    Raczyński, L.; Moskal, P.; Kowalski, P.; Wiślicki, W.; Bednarski, T.; Białas, P.; Czerwiński, E.; Gajos, A.; Kapłon, Ł.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kozik, T.; Krzemień, W.; Kubicz, E.; Niedźwiecki, Sz.; Pałka, M.; Rudy, Z.; Rundel, O.; Salabura, P.; Sharma, N. G.; Silarski, M.; Słomski, A.; Smyrski, J.; Strzelecki, A.; Wieczorek, A.; Zieliński, M.; Zoń, N.

    2015-06-01

    The J-PET scanner, which allows for single bed imaging of the whole human body, is currently under development at the Jagiellonian University. The discussed detector offers improvement of the Time of Flight (TOF) resolution due to the use of fast plastic scintillators and dedicated electronics allowing for sampling in the voltage domain of signals with durations of few nanoseconds. In this paper we show that recovery of the whole signal, based on only a few samples, is possible. In order to do that, we incorporate the training signals into the Tikhonov regularization framework and we perform the Principal Component Analysis decomposition, which is well known for its compaction properties. The method yields a simple closed form analytical solution that does not require iterative processing. Moreover, from the Bayes theory the properties of regularized solution, especially its covariance matrix, may be easily derived. This is the key to introduce and prove the formula for calculations of the signal recovery error. In this paper we show that an average recovery error is approximately inversely proportional to the number of acquired samples.

  10. Comparison of different threshold 18FDG PET with computer tomography for defining gross tumor volume in non-small cell lung carcinoma

    International Nuclear Information System (INIS)

    Chen Shaoqing; Yu Jinming; Xing Ligang; Gong Heyi; Fu Zheng; Yang Guoren

    2006-01-01

    Objective: Under different standard uptake value(SUV), to assess gross tumor volume (GTV) definition for non-small cell lung cancer (NSCLC) with 18-fluoro-deoxy-glueose positron emission tomography( 18 FDG PET) both under definite threshold (42 percent threshold) and various relative threshold (threshold SUV/maximum SUV) derived from the linear regressive function, threshold SUV=0.307 x (mean target SUV) + 0.588, with computer tomography(CT). Methods: Of 20 patients with non-small cell lung cancer, the CT GTV (GTV CT ), PET GTV with 42 percents threshold (GTV 42% ) and PET GTV with relative threshold (GTV relate ) were obtained and compared. Results: The mean GTV 42% , mean GTV relate and mean GTV CT was (13 812.5±13 841.4), (24 325.3±22 454.7) and (28350.9± 26 079.8) mm 3 , respectively, with the difference in mean GTV among these three methods significant (F =. 10, P 42% was smaller than the GTV relate and the GTV CT (P relate and GTV CT (P = 0.125 ). Conclusion: The relative threshold is more suitable to define the gross tumor volume than the definite threshold. (authors)

  11. PET in neuro-oncology

    NARCIS (Netherlands)

    Roelcke, U; Leenders, K.L.

    This article reviews possible clinical applications of positron emission tomography (PET) in brain tumor patients. PET allows quantitative assessment of brain tumor pathophysiology and biochemistry. It therefore provides different information about tumors when compared to histological or

  12. SU-E-I-86: Ultra-Low Dose Computed Tomography Attenuation Correction for Pediatric PET CT Using Adaptive Statistical Iterative Reconstruction (ASiR™)

    Energy Technology Data Exchange (ETDEWEB)

    Brady, S; Shulkin, B [St. Jude Children’s Research Hospital, Memphis, TN (United States)

    2015-06-15

    Purpose: To develop ultra-low dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultra-low doses (10–35 mAs). CT quantitation: noise, low-contrast resolution, and CT numbers for eleven tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% CTDIvol (0.39/3.64; mGy) radiation dose from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUVbw) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation organ dose, as derived from patient exam size specific dose estimate (SSDE), was converted to effective dose using the standard ICRP report 103 method. Effective dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative patient population dose reduction and noise control. Results: CT numbers were constant to within 10% from the non-dose reduced CTAC image down to 90% dose reduction. No change in SUVbw, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols reconstructed with ASiR and down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62%–86% (3.2/8.3−0.9/6.2; mSv). Noise magnitude in dose-reduced patient images increased but was not statistically different from pre dose-reduced patient images. Conclusion: Using ASiR allowed for aggressive reduction in CTAC dose with no change in PET reconstructed images while maintaining sufficient image quality for co

  13. Positron emission tomography/magnetic resonance imaging (PET/MRI: An update and initial experience at HC-FMUSP

    Directory of Open Access Journals (Sweden)

    Marcelo A. Queiroz

    Full Text Available Summary The new technology of PET/MRI is a prototype of hybrid imaging, allowing for the combination of molecular data from PET scanning and morphofunctional information derived from MRI scanning. Recent advances regarding the technical aspects of this device, especially after the development of MRI-compatible silicon photomultipliers of PET, permitted an increase in the diagnostic performance of PET/MRI translated into dose reduction and higher imaging quality. Among several clinical applications, PET/MRI gains ground initially in oncology, where MRI per se plays an essential role in the assessment of primary tumors (which is limited in the case of PET/CT, including prostate, rectal and gynecological tumors. On the other hand, the evaluation of the lungs remains an enigma although new MRI sequences are being designed to overcome this. More clinical indications of PET/MRI are seen in the fields of neurology, cardiology and inflammatory processes, and the use of PET/MRI also opens perspectives for pediatric populations as it involves very low radiation exposure. Our review aimed to highlight the current indications of PET/MRI and discuss the challenges and perspectives of PET/MRI at HC-FMUSP.

  14. Synthesis and functionalization of bifunctional chelates for 64Cu complexation for their applications by positron emission tomography (PET) imaging and radiotherapy

    International Nuclear Information System (INIS)

    Roux, Amandine

    2014-01-01

    This work aimed to develop a new family of bis-pidine-type ligands for copper(II) complexation with applications in Positron Emission Tomography (PET). Indeed, copper 64 is a radioelement whose study in PET imaging is booming. Bis-pidines have the benefit of having a rigid and pre-organized structure for complexation of a large number of transition metals. In this work we present the synthesis and optimization of new ligands whose structural and physico-chemical properties have been studied. One ligand showed very good results because it possesses all of kinetic and thermodynamic parameters which are necessary for its application to PET imaging. Different strategies of functionalization have been studied to obtain bifunctional chelates. A lysine derivative has been coupled to a maleimide function (regio-selective of cysteines), to abiotine (which displays a strong affinity for streptavidin) or to a Bodipy pattern for obtaining a bimodal probe (UV-visible and PET). Finally, we present an extension of this bis-pidine family by increasing the number of coordination functions or by synthesizing tricyclic compounds to modulate the selectivity of these molecules. (author)

  15. [1-11C]octanoate as a PET tracer for studying ischemic stroke. Evaluation in a canine model of thromboembolic stroke with positron emission tomography

    International Nuclear Information System (INIS)

    Kuge, Yuji; Kawashima, Hidefumi; Minematsu, Kazuo

    2000-01-01

    Octanoate is taken up by the brain and converted in astrocytes to glutamine through the TCA cycle after β-oxidation. Consequently, [1- 11 C]octanoate might serve as a useful positron emission tomography (PET) probe for studying cerebral oxidative metabolism and/or astroglial functions. The present study attempted to evaluate the utility of using [1- 11 C]octanoate as a PET tracer for imaging and evaluating the pathophysiology of ischemic stroke. We used a canine model of thromboembolic stroke. Five male beagle dogs were implanted with an indwelling catheter in the left internal carotid artery. A single autologous blood clot was injected into the left internal carotid artery through the catheter. The brain distribution of [1- 11 C]octanoate and cerebral blood flow (CBF) were determined 24 h after insult using a high resolution PET scanner. Post mortem brain regions unstained with 2, 3, 5-triphenyltetrazolium chloride (TTC) were defined as infarcts. In the region of an infarct, accumulation of [1- 11 C]octanoate decreased concurrently with CBF reduction. In contrast, normal accumulation of [1- 11 C]octanoate was observed in ischemic but vital regions, suggesting that an increased accumulation of [1- 11 C]octanoate relative to CBF takes place in these regions. In conclusion, [1- 11 C]octanoate accumulated in ischemic but vital regions, indicating that [1- 11 C]octanoate is a potentially useful PET tracer for imaging and evaluating the pathophysiology of ischemic stroke. (author)

  16. Test-retest variability of high resolution positron emission tomography (PET) imaging of cortical serotonin (5HT2A) receptors in older, healthy adults

    International Nuclear Information System (INIS)

    Chow, Tiffany W; Mamo, David C; Uchida, Hiroyuki; Graff-Guerrero, Ariel; Houle, Sylvain; Smith, Gwenn S; Pollock, Bruce G; Mulsant, Benoit H

    2009-01-01

    Position emission tomography (PET) imaging using [ 18 F]-setoperone to quantify cortical 5-HT 2A receptors has the potential to inform pharmacological treatments for geriatric depression and dementia. Prior reports indicate a significant normal aging effect on serotonin 5HT 2A receptor (5HT 2A R) binding potential. The purpose of this study was to assess the test-retest variability of [ 18 F]-setoperone PET with a high resolution scanner (HRRT) for measuring 5HT 2A R availability in subjects greater than 60 years old. Methods: Six healthy subjects (age range = 65–78 years) completed two [ 18 F]-setoperone PET scans on two separate occasions 5–16 weeks apart. The average difference in the binding potential (BP ND ) as measured on the two occasions in the frontal and temporal cortical regions ranged between 2 and 12%, with the lowest intraclass correlation coefficient in anterior cingulate regions. We conclude that the test-retest variability of [ 18 F]-setoperone PET in elderly subjects is comparable to that of [ 18 F]-setoperone and other 5HT 2A R radiotracers in younger subject samples

  17. 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

  18. Handheld ultrahigh speed swept source optical coherence tomography instrument using a MEMS scanning mirror.

    Science.gov (United States)

    Lu, Chen D; Kraus, Martin F; Potsaid, Benjamin; Liu, Jonathan J; Choi, Woojhon; Jayaraman, Vijaysekhar; Cable, Alex E; Hornegger, Joachim; Duker, Jay S; Fujimoto, James G

    2013-12-20

    We developed an ultrahigh speed, handheld swept source optical coherence tomography (SS-OCT) ophthalmic instrument using a 2D MEMS mirror. A vertical cavity surface-emitting laser (VCSEL) operating at 1060 nm center wavelength yielded a 350 kHz axial scan rate and 10 µm axial resolution in tissue. The long coherence length of the VCSEL enabled a 3.08 mm imaging range with minimal sensitivity roll-off in tissue. Two different designs with identical optical components were tested to evaluate handheld OCT ergonomics. An iris camera aided in alignment of the OCT beam through the pupil and a manual fixation light selected the imaging region on the retina. Volumetric and high definition scans were obtained from 5 undilated normal subjects. Volumetric OCT data was acquired by scanning the 2.4 mm diameter 2D MEMS mirror sinusoidally in the fast direction and linearly in the orthogonal slow direction. A second volumetric sinusoidal scan was obtained in the orthogonal direction and the two volumes were processed with a software algorithm to generate a merged motion-corrected volume. Motion-corrected standard 6 x 6 mm(2) and wide field 10 x 10 mm(2) volumetric OCT data were generated using two volumetric scans, each obtained in 1.4 seconds. High definition 10 mm and 6 mm B-scans were obtained by averaging and registering 25 B-scans obtained over the same position in 0.57 seconds. One of the advantages of volumetric OCT data is the generation of en face OCT images with arbitrary cross sectional B-scans registered to fundus features. This technology should enable screening applications to identify early retinal disease, before irreversible vision impairment or loss occurs. Handheld OCT technology also promises to enable applications in a wide range of settings outside of the traditional ophthalmology or optometry clinics including pediatrics, intraoperative, primary care, developing countries, and military medicine.

  19. Adenosine A1 receptors in human sleep regulation studied by electroencephalography (EEG) and positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Geissler, E.

    2007-01-01

    Sleep is an essential physiological process. However, the functions of sleep and the endogenous mechanisms involved in sleep regulation are only partially understood. Convergent lines of evidence support the hypothesis that the build-up of sleep propensity during wakefulness and its decline during sleep are associated with alterations in brain adenosine levels and adenosine receptor concentrations. The non-selective A 1 and A 2A adenosine receptor antagonist caffeine stimulates alertness and is known to attenuate changes in the waking and sleep electroencephalogram (EEG) typically observed after prolonged waking. Several findings point to an important function of the adenosine A 1 receptor (A 1 AR) in the modulation of vigilance states. The A 1 AR is densely expressed in brain regions involved in sleep regulation, and pharmacological manipulations affecting the A 1 AR were shown to influence sleep propensity and sleep depth. However, an involvement of the A 2A adenosine receptor (A 2A AR) is also assumed. The distinct functions of the A 1 and A 2A receptor subtypes in sleep-wake regulation and in mediating the effects of caffeine have not been identified so far. The selective adenosine A 1 receptor antagonist, 8-cyclopentyl-3-(3- 18 Ffluoropropyl)- 1-propylxanthine ( 18 F-CPFPX), offers the opportunity to get further insights into adenosinergic mechanisms by in vivo imaging of the A 1 AR subtype with positron emission tomography (PET). The aim of this thesis was to elucidate the role of adenosine A 1 receptors in human sleep regulation, combining 18 F-CPFPX PET brain imaging and EEG recordings, the gold standard in sleep research. It was hypothesized that sleep deprivation would induce adenosine accumulation and/or changes in A 1 AR density. Thus, the question was addressed whether these effects of prolonged wakefulness can be visualized by altered 18 F-CPFPX binding. Moreover, it was investigated whether radioligand uptake might be influenced by caffeine, since

  20. Cone-beam computed tomography analysis of curved root canals after mechanical preparation with three nickel-titanium rotary instruments

    Science.gov (United States)

    Elsherief, Samia M.; Zayet, Mohamed K.; Hamouda, Ibrahim M.

    2013-01-01

    Cone beam computed tomography is a 3-dimensional high resolution imaging method. The purpose of this study was to compare the effects of 3 different NiTi rotary instruments used to prepare curved root canals on the final shape of the curved canals and total amount of root canal transportation by using cone-beam computed tomography. A total of 81 mesial root canals from 42 extracted human mandibular molars, with a curvature ranging from 15 to 45 degrees, were selected. Canals were randomly divided into 3 groups of 27 each. After preparation with Protaper, Revo-S and Hero Shaper, the amount of transportation and centering ability that occurred were assessed by using cone beam computed tomography. Utilizing pre- and post-instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. Canals were metrically assessed for changes (surface area, changes in curvature and transportation) during canal preparation by using software SimPlant; instrument failures were also recorded. Mean total widths and outer and inner width measurements were determined on each central canal path and differences were statistically analyzed. The results showed that all instruments maintained the original canal curvature well with no significant differences between the different files (P = 0.226). During preparation there was failure of only one file (the protaper group). In conclusion, under the conditions of this study, all instruments maintained the original canal curvature well and were safe to use. Areas of uninstrumented root canal wall were left in all regions using the various systems. PMID:23885273

  1. Low-dose computed tomography scans with automatic exposure control for patients of different ages undergoing cardiac PET/CT and SPECT/CT.

    Science.gov (United States)

    Yang, Ching-Ching; Yang, Bang-Hung; Tu, Chun-Yuan; Wu, Tung-Hsin; Liu, Shu-Hsin

    2017-06-01

    This study aimed to evaluate the efficacy of automatic exposure control (AEC) in order to optimize low-dose computed tomography (CT) protocols for patients of different ages undergoing cardiac PET/CT and single-photon emission computed tomography/computed tomography (SPECT/CT). One PET/CT and one SPECT/CT were used to acquire CT images for four anthropomorphic phantoms representative of 1-year-old, 5-year-old and 10-year-old children and an adult. For the hybrid systems investigated in this study, the radiation dose and image quality of cardiac CT scans performed with AEC activated depend mainly on the selection of a predefined image quality index. Multiple linear regression methods were used to analyse image data from anthropomorphic phantom studies to investigate the effects of body size and predefined image quality index on CT radiation dose in cardiac PET/CT and SPECT/CT scans. The regression relationships have a coefficient of determination larger than 0.9, indicating a good fit to the data. According to the regression models, low-dose protocols using the AEC technique were optimized for patients of different ages. In comparison with the standard protocol with AEC activated for adult cardiac examinations used in our clinical routine practice, the optimized paediatric protocols in PET/CT allow 32.2, 63.7 and 79.2% CT dose reductions for anthropomorphic phantoms simulating 10-year-old, 5-year-old and 1-year-old children, respectively. The corresponding results for cardiac SPECT/CT are 8.4, 51.5 and 72.7%. AEC is a practical way to reduce CT radiation dose in cardiac PET/CT and SPECT/CT, but the AEC settings should be determined properly for optimal effect. Our results show that AEC does not eliminate the need for paediatric protocols and CT examinations using the AEC technique should be optimized for paediatric patients to reduce the radiation dose as low as reasonably achievable.

  2. Evaluation of apical canal shapes produced sequentially during instrumentation with stainless steel hand and Ni-Ti rotary instruments using Micro-computed tomography

    Directory of Open Access Journals (Sweden)

    Woo-Jin Lee

    2011-05-01

    Full Text Available Objectives The purpose of this study was to determine the optimal master apical file size with minimal transportation and optimal efficiency in removing infected dentin. We evaluated the transportation of the canal center and the change in untouched areas after sequential preparation with a #25 to #40 file using 3 different instruments: stainless steel K-type (SS K-file hand file, ProFile and LightSpeed using microcomputed tomography (MCT. Materials and Methods Thirty extracted human mandibular molars with separated orifices and apical foramens on mesial canals were used. Teeth were randomly divided into three groups: SS K-file, Profile, LightSpeed and the root canals were instrumented using corresponding instruments from #20 to #40. All teeth were scanned with MCT before and after instrumentation. Cross section images were used to evaluate canal transportation and untouched area at 1- , 2- , 3- , and 5- mm level from the apex. Data were statistically analyzed according to' repeated nested design'and Mann-Whitney test (p = 0.05. Results In SS K-file group, canal transportation was significantly increased over #30 instrument. In the ProFile group, canal transportation was significantly increased after preparation with the #40 instrument at the 1- and 2- mm levels. LightSpeed group showed better centering ability than ProFile group after preparation with the #40 instrument at the 1 and 2 mm levels. Conclusions SS K-file, Profile, and LightSpeed showed differences in the degree of apical transportation depending on the size of the master apical file.

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

    International Nuclear Information System (INIS)

    Masala, Salvatore; Bartolucci, Alberto D.; Mammucari, Matteo; Simonetti, Giovanni; Schillaci, Orazio; Calabria, Ferdinando

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

  5. A Case of Low-Grade Primary Cardiac Lymphoma with Pericardial Effusion Diagnosed by Combined 18F-Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography (FDG-PET/CT) Imaging and Effusion Cytology.

    Science.gov (United States)

    Fukunaga, Hisanori; Tatewaki, Yasuko; Mutoh, Tatsushi; Shimomura, Hideo; Yamamoto, Shuzo; Terao, Chiaki; Totsune, Tomoko; Nakagawa, Manabu; Taki, Yasuyuki

    2018-03-14

    BACKGROUND Primary cardiac lymphoma is rare and can be an aggressive disease, depending on the grade. A case is reported of low-grade primary cardiac lymphoma associated with a pericardial effusion. 18F-fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) imaging was useful in the diagnosis and in evaluating the disease activity in this case. CASE REPORT A 72-year-old Japanese woman visited a general practitioner, complaining of dyspnea associated with cardiac tamponade. Pericardiocentesis was performed, and Group V malignant cells were identified by cytology, suspicious for malignant lymphoma. Whole-body FDG-PET/CT scans showed no pleural effusion or lymph node metastasis supporting the diagnosis of primary cardiac lymphoma diagnosed on pericardial effusion. The laboratory investigations showed that levels of serum soluble interleukin-2 (IL-2) receptor (sIL-2R), a diagnostic and prognostic marker for malignant lymphoma, were not elevated (258 U/ml). A six-month follow-up FDG-PET/CT scan showed an increased volume of the pericardial effusion and mild but abnormal uptake diffusely in the pericardial space, and the sIL-2R was slightly elevated (860 U/ml). No abnormal FDG accumulation outside the retained pericardial effusion was noted, which was compatible with a clinical picture of low-grade primary cardiac lymphoma, and in a period of watchful waiting during the first two years later, the sIL-2R had reduced to 195 U/ml. CONCLUSIONS This is a rare case of low-grade primary cardiac lymphoma detected in a pericardial effusion, and highlights the utility of the FDG-PET/CT scan as a valuable diagnostic and follow-up modality.

  6. Evaluation of pulmonary nodules and lung cancer with one-inch crystal gamma coincidence positron emission tomography/CT versus dedicated positron emission tomography/CT

    International Nuclear Information System (INIS)

    Moodie, K.; Lau, E.; Hicks, R. J.; Cherk, M. H.; Turlakow, A.; Skinner, S.; Kelly, M. J.; Kalff, V.

    2009-01-01

    Full text: Dedicated positron emission tomography (PET)/CT scanners using BGO and related detectors (d-PET) have become standard imaging instruments in many malignancies. Hybrid gamma camera systems using Nal detectors in coincidence mode (g-PET) have been compared to d-PET but reported usefulness has been variable when gamma cameras with half-inch to three-fourth-inch thick crystals have been used without CT. Our aim was to compare g-PET with a 1-in.-thick crystal and inbuilt CT for lesion localization and attenuation correction (g-PET/CT) and d-PET/CT in patients presenting with potential and confirmed lung malignancies. One hour after 18F-fluorodeoxyglucose (FDG), patients underwent BGO d-PET/CT from jaw to proximal thigh. This was followed by one to two bed position g-PET/CT 194 + 27 min after FDG. Each study pair was independently analysed with concurrent CT. d-PET/CT was interpreted by a radiologist experienced in both PET and CT, and g-PET/CT by consensus reading of an experienced PET physician and an experienced CT radiologist, A TNM score was assigned and studies were then unblinded and compared. Fifty-seven patients underwent 58 scan pairs over 2 years. Eighty-nine percent concordance was shown between g-PET/CT and d-PET/CT for the assessment of I intrapulmonary lesions, with 100% concordance for intrapulmonary lesions I >10 mm (36 of 36). Eighty-eight per cent (51 of 58) concordance was shown between g-PET/CTand d-PET/CTforTNM staging. Coincidence imaging usingan optimized dual-head 1-in.-thick crystal gamma camera with inbuilt CT compares reasonably well with dedicated PET/CT for evaluation of indeterminate pulmonary lesions and staging of pulmonary malignancies and may be of some] value when d-PET/CT is not readily available.

  7. Cardiac positron tomography

    International Nuclear Information System (INIS)

    Geltmann, E.M.; Roberts, R.; Sobel, B.E.

    1980-01-01

    Positron emission tomography (PET) performed after the administration of the positron-emitting radionuclides carbon-11 ( 11 C), nitrogen-13 ( 13 N), oxygen-15 ( 15 O) and fluorine-18 ( 18 F) has permitted the improved noninvasive assessment of the regional myocardial metabolism of normal physiologic substrates and intermediates and their cogeners. In experimental animals, the rate of oxidation of 11 C-palmitate correlates closely with other indexes of oxygen consumption, and the extraction of 11 C-palmitate (like that of 18 F-fatty acids and 18 F-fluoredoxyglucose) ist markedly diminished in regions of myocardial ischemia. In both experimental animals and in patients, myocardial infarct site and size, determined by positron emission tomography after the intravenous injection of 11 C-palmitate, correlate closely with the electrocardiographic infarct locus and enzymatically estimated infarct size as well as with the location and extent of regional left ventricular wall motion abnormalities. PET offers promise for assessment of flow as well despite the complexities involved. PET with 13 NH 3 appears to provide one useful qualitative index, although this tracer ist actively metabolized. Because of the quantitative capabilities of positron emission tomography and the rapid progress which is being made in the development of fast scan, multi-slice, and gated instrumentation, this technique is likely to facilitate improved understanding and characterization of regional myocardial metabolism and blood flow in man under physiological and pathophysiological conditions. (orig.) [de

  8. Tomography

    International Nuclear Information System (INIS)

    1985-01-01

    Already widely accepted in medicine, tomography can also be useful in industry. The theory behind tomography and a demonstration of the technique to inspect a motorcycle carburetor is presented. To demonstrate the potential of computer assisted tomography (CAT) to accurately locate defects in three dimensions, a sectioned 5 cm gate valve with a shrink cavity made visible by the sectioning was tomographically imaged using a Co-60 source. The tomographic images revealed a larger cavity below the sectioned surface. The position of this cavity was located with an in-plane and axial precision of approximately +-1 mm. The volume of the cavity was estimated to be approximately 40 mm 3

  9. 18F-FDG whole body positron emission tomography (PET) in patients with unknown primary tumours (UPT)

    DEFF Research Database (Denmark)

    Lassen, U; Daugaard, G; Eigtved, A

    1999-01-01

    adenocarcinomas and 1 poorly differentiated carcinoma). The remaining patients had metastases located in bone (3), bone marrow (1), brain (1), pericardium (1), skin (1), pleura (1) and chest wall (1). All metastatic lesions were visible with PET. In 13 patients PET suggested the site for the primary tumour...... by the PET result. The rest received either radical radiotherapy to the head and neck region (7), palliative radiotherapy to the metastatic lesion (8), chemotherapy based on signet ring cell carcinoma in bone marrow (1) or no therapy (1). These results indicates that PET is useful in UPT preceding expensive......The management of patients with unknown primary tumours (UPT) often includes a large number of radiographical studies and invasive procedures, but the occult primary tumour is detected in less than 25%. In this prospective study we explored whether non-invasive whole body PET scans using FDG (18-F...

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

    International Nuclear Information System (INIS)

    Higashi, Tatsuya; Saga, Tsuneo; Ishimori, Takayoshi; Fujimoto, Koji; Doi, Ryuichiro; Imamura, Masayuki; Konishi, Junji

    2003-01-01

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

  11. 2-[F-18] fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in uncommon malignancies

    International Nuclear Information System (INIS)

    Nair, N.; Basu, S.

    2004-01-01

    This is a retrospective study with an aim to evaluate the clinical role of FDG-PET imaging in changing the decision making process or management strategies in patients with various uncommon malignancies or in malignancies where there is paucity of literature regarding application of PET at present. The study population consisted of a wide variety of various uncommon malignancies who were mainly referred from the neighboring Tata Memorial Hospital with few cases from the outside centers. Patients were fasting at least for 6 hours. Sixty minutes after injection of 370 MBq FDG, patients were imaged on the dedicated BGO based GE Advance PET scanner (General Electric Medical systems, Milwaukee, WI). Images were reconstructed using the attenuation weighted Ordered Subsets Expectation Maximization (OSEM) algorithm. Axial, coronal, sagittal and 3D images were visually interpreted and foci of increased tracer uptake were considered as disease involvement. The findings were compared lesion by lesion with other imaging procedures regarding staging, treatment response evaluation and residual disease evaluation. The malignancies selected for retrospective analysis, along with the number of cases are presented. 2 cases of chordoma were evaluated of which one had primary in the cervicodorsal region and came for PET evaluation post surgery and RT. PET showed metastatic foci in left axillary node, body of sacrum and right lower neck region in addition to the persistence of disease in the primary. The other was a case of petroclival chordoma came for disease evaluation post surgery. The MRI was inconclusive regarding persistence of residual disease and postoperative changes. PET scan was normal in the case. In a solitary case of operated Dermato-fibrosarcoma, PET revealed a hypermetabolic focus at one end of scar, subsequently proven as scar recurrence of the primary. 3 cases of skin adenexal tumour were evaluated, all of whom were upstaged by PET and changed the subsequent

  12. Measuring receptor occupancy with PET

    NARCIS (Netherlands)

    van Waarde, A

    Many physiological and biochemical measurements can be performed noninvasively in humans with modern imaging techniques like magnetic resonance imaging (MRI), positron emission tomography (PET) or single-photon emission computed tomography (SPECT). This review focuses on the monitoring of

  13. The system of the designing for PET detectors

    International Nuclear Information System (INIS)

    Fang Zongliang

    2006-01-01

    PET stands for Positron Emission Tomography, a new nuclear medicine imaging device. PET detector is the key of PET. This paper introduces a system of the designing for PET detector. The system can be used to design various PET detector. A PET detector BLOCK with 8 x 8 crystals has been designed and built by this system. (authors)

  14. Temporal lobe dysfunction in childhood autism: a PET study; Dysfonctionnement bitemporal dans l'autisme infantile: etude en tomographie par emission de positons

    Energy Technology Data Exchange (ETDEWEB)

    Boddaert, N; Poline, J B; Brunelle, F; Zilbovicius, M [Service Hospitalier Frederic Joliot, ER-M INSERM 0205, DSV, DRM CEA, 91 - Orsay (France); Brunelle, F [Centre Hospitalier Universitaire Necker-Enfants-Malades, Service de Radiologie Pediatrique, 75 - Paris (France); Chabane, N [Hopital Robert-Debre, Service de Pedopsychiatrie, 75 - Paris (France); Barthelemy, C; Zilbovicius, M [Centre Hospitalier Universitaire Bretonneau, INSERM Unite 316, 37 - Tours (France); Bourgeois, M [Centre Hospitalier Universitaire Necker-Enfants-Malades, Dept. de Pediatrie, 75 - Paris (France); Samson, Y [Centre Hospitalier Universitaire Pitie-Salpetriere, Service des Urgences Cerebraux Vasculaires, 75 - Paris (France)

    2002-12-01

    Childhood autism is a severe developmental disorder that impairs the acquisition of some of the most important skills in human life. Progress in understanding the neural basis of childhood autism requires clear and reliable data indicating specific neuro-anatomical or neuro-physiological abnormalities. The purpose of the present study was to research localized brain dysfunction in autistic children using functional brain imaging. Regional cerebral blood flow (rCBF) was measured with positron emission tomography (PET) in 21 primary autistic children and 10 age-matched non autistic children. A statistical parametric analysis of rCBF images revealed significant bilateral temporal hypoperfusion in the associative auditory cortex (superior temporal gyrus) and in the multimodal cortex (superior temporal sulcus) in the autistic group (p<0.001). In addition, temporal hypoperfusion was detected individually in 77% of autistic children. These findings provide robust evidence of well localized functional abnormalities in autistic children located in the superior temporal lobe. Such localized abnormalities were not detected with the low resolution PET camera (14-22). This study suggests that high resolution PET camera combined with statistical parametric mapping is useful to understand developmental disorders. (authors)

  15. Temporal lobe dysfunction in childhood autism: a PET study; Dysfonctionnement bitemporal dans l'autisme infantile: etude en tomographie par emission de positons

    Energy Technology Data Exchange (ETDEWEB)

    Boddaert, N.; Poline, J.B.; Brunelle, F.; Zilbovicius, M. [Service Hospitalier Frederic Joliot, ER-M INSERM 0205, DSV, DRM CEA, 91 - Orsay (France); Brunelle, F. [Centre Hospitalier Universitaire Necker-Enfants-Malades, Service de Radiologie Pediatrique, 75 - Paris (France); Chabane, N. [Hopital Robert-Debre, Service de Pedopsychiatrie, 75 - Paris (France); Barthelemy, C.; Zilbovicius, M. [Centre Hospitalier Universitaire Bretonneau, INSERM Unite 316, 37 - Tours (France); Bourgeois, M. [Centre Hospitalier Universitaire Necker-Enfants-Malades, Dept. de Pediatrie, 75 - Paris (France); Samson, Y. [Centre Hospitalier Universitaire Pitie-Salpetriere, Service des Urgences Cerebraux Vasculaires, 75 - Paris (France)

    2002-12-01

    Childhood autism is a severe developmental disorder that impairs the acquisition of some of the most important skills in human life. Progress in understanding the neural basis of childhood autism requires clear and reliable data indicating specific neuro-anatomical or neuro-physiological abnormalities. The purpose of the present study was to research localized brain dysfunction in autistic children using functional brain imaging. Regional cerebral blood flow (rCBF) was measured with positron emission tomography (PET) in 21 primary autistic children and 10 age-matched non autistic children. A statistical parametric analysis of rCBF images revealed significant bilateral temporal hypoperfusion in the associative auditory cortex (superior temporal gyrus) and in the multimodal cortex (superior temporal sulcus) in the autistic group (p<0.001). In addition, temporal hypoperfusion was detected individually in 77% of autistic children. These findings provide robust evidence of well localized functional abnormalities in autistic children located in the superior temporal lobe. Such localized abnormalities were not detected with the low resolution PET camera (14-22). This study suggests that high resolution PET camera combined with statistical parametric mapping is useful to understand developmental disorders. (authors)

  16. Positron emission tomography study on pancreatic somatostatin receptors in normal and diabetic rats with 68Ga-DOTA-octreotide: a potential PET tracer for beta cell mass measurement.

    Science.gov (United States)

    Sako, Takeo; Hasegawa, Koki; Nishimura, Mie; Kanayama, Yousuke; Wada, Yasuhiro; Hayashinaka, Emi; Cui, Yilong; Kataoka, Yosky; Senda, Michio; Watanabe, Yasuyoshi

    2013-12-06

    Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, and the loss or dysfunction of pancreatic beta cells has been reported before the appearance of clinical symptoms and hyperglycemia. To evaluate beta cell mass (BCM) for improving the detection and treatment of DM at earlier stages, we focused on somatostatin receptors that are highly expressed in the pancreatic beta cells, and developed a positron emission tomography (PET) probe derived from octreotide, a metabolically stable somatostatin analog. Octreotide was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a chelating agent, and labeled with (68)Gallium ((68)Ga). After intravenous injection of (68)Ga-DOTA-octreotide, a 90-min emission scan of the abdomen was performed in normal and DM model rats. The PET studies showed that (68)Ga-DOTA-octreotide radioactivity was highly accumulated in the pancreas of normal rats and that the pancreatic accumulation was significantly reduced in the rats administered with an excess amount of unlabeled octreotide or after treatment with streptozotocin, which was used for the chemical induction of DM in rats. These results were in good agreement with the ex vivo biodistribution data. These results indicated that the pancreatic accumulation of (68)Ga-DOTA-octreotide represented specific binding to the somatostatin receptors and reflected BCM. Therefore, PET imaging with (68)Ga-DOTA-octreotide could be a potential tool for evaluating BCM. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. The journey: from X-rays to PET-MRI

    International Nuclear Information System (INIS)

    Sheikh, Tariq Hussain

    2010-01-01

    Full text: Medical imaging has undergone remarkable evolution over the past century. Since the discovery of the X-rays by (Wilhelm Conrad Roentgen), static emission tomography (Hal Anger) computed tomography (Godfrey Hounsfield and Alan Cormack), and magnetic resonance imaging (Paul Lauterbur and Peter Mansfield) there have been many other important discoveries and technical developments that have culminated in our current sophisticated multi-modality imaging systems. Nobel Prizes have been given for the discoveries of radioactivity (Marie Curie, Pierre Curie, and Henri Becquerel in 1903) and the positron (Carl Anderson in 1936) and for technical developments such as the radiotracer concept (George De Hevesy in 1943). Positron emission detection systems have developed since their first use in the 1950s to the high-resolution, high-sensitivity tomographic devices that we have today. In keeping pace with these milestones in the evolution of medical imaging, positron emission tomography (PET), and more recently integrated positron emission tomography-computed tomography (PET-CT), have now emerged not only as important research tools but also as significant diagnostic imaging systems in clinical medicine. The use of multi-modality imaging systems and 'smart' specific imaging agents will achieve the key task of accurate diagnosis, treatment evaluation, surveillance, and prognosis in individual patients. PET-CT instrumentation has continued to evolve rapidly, especially over the last decade A PET scanner is combined with a CT scanner into a single machine. The PET and CT components are mounted on the same aluminium support with the CT on the front and PET at the back. Metabolic information is obtained from the PET scanner (emission of annihilation photons) and anatomic information is obtained from the CT scan (transmission of X-Rays). In addition, the CT scan can be used to provide information needed for attenuation correction. The current generation of PET-CT scanners

  18. Positron emission tomography (PET) and magnetic resonance imaging (MRI) for the assessment of axillary lymph node metastases in early breast cancer: systematic review and economic evaluation.

    Science.gov (United States)

    Cooper, K L; Meng, Y; Harnan, S; Ward, S E; Fitzgerald, P; Papaioannou, D; Wyld, L; Ingram, C; Wilkinson, I D; Lorenz, E

    2011-01-01

    Breast cancer is the most common type of cancer in women. Evaluation of axillary lymph node metastases is important for breast cancer staging and treatment planning. To evaluate the diagnostic accuracy, cost-effectiveness and effect on patient outcomes of positron emission tomography (PET), with or without computed tomography (CT), and magnetic resonance imaging (MRI) in the evaluation of axillary lymph node metastases in patients with newly diagnosed early-stage breast cancer. A systematic review of literature and an economic evaluation were carried out. Key databases (including MEDLINE, EMBASE and nine others) plus research registers and conference proceedings were searched for relevant studies up to April 2009. A decision-analytical model was developed to determine cost-effectiveness in the UK. One reviewer assessed titles and abstracts of studies identified by the search strategy, obtained the full text of relevant papers and screened them against inclusion criteria. Data from included studies were extracted by one reviewer using a standardised data extraction form and checked by a second reviewer. Discrepancies were resolved by discussion. Quality of included studies was assessed using the quality assessment of diagnostic accuracy studies (QUADAS) checklist, applied by one reviewer and checked by a second. Forty-five citations relating to 35 studies were included in the clinical effectiveness review: 26 studies of PET and nine studies of MRI. Two studies were included in the cost-effectiveness review: one of PET and one of MRI. Of the seven studies evaluating PET/CT (n = 862), the mean sensitivity was 56% [95% confidence interval (CI) 44% to 67%] and mean specificity 96% (95% CI 90% to 99%). Of the 19 studies evaluating PET only (n = 1729), the mean sensitivity was 66% (95% CI 50% to 79%) and mean specificity 93% (95% CI 89% to 96%). PET performed less well for small metastases; the mean sensitivity was 11% (95% CI 5% to 22%) for micrometastases (≤ 2 mm

  19. 18F-FDG whole body positron emission tomography (PET) in patients with unknown primary tumours (UPT)

    DEFF Research Database (Denmark)

    Lassen, U; Daugaard, G; Eigtved, A

    1999-01-01

    -fluorodeoxyglucose) are of clinical value in detection of UPT. Whole-body FDG-PET scans were performed in 20 patients following standard staging procedures according to histology. PET results were verified either histologically or by the clinical course of the disease. 11 patients had neck metastases (5 squamous cell, 5......The management of patients with unknown primary tumours (UPT) often includes a large number of radiographical studies and invasive procedures, but the occult primary tumour is detected in less than 25%. In this prospective study we explored whether non-invasive whole body PET scans using FDG (18-F...... and this was verified in 9 (45%), either histologically or by the clinical course of disease. 8 of these had primary lung cancer and 1 had carcinoma at the basis of the tongue. In most patients PET had no treatment related implications. 3 patients with non-small cell lung cancer (NSCLC) received chemotherapy prompted...

  20. Usefulness of CA125 and their kinetic parameters and positron emission tomography/computed tomography (PET/CT) with fluorodeoxyglucose ([18F] FDG) in the detection of recurrent ovarian cancer levels.

    Science.gov (United States)

    Palomar Muñoz, Azahara; Cordero García, José Manuel; Talavera Rubio, Prado; García Vicente, Ana M; González García, Beatriz; Bellón Guardia, María Emiliana; Soriano Castrejón, Ángel; Aranda Aguilar, Enrique

    2017-12-21

    To assess the usefulness of cancer antigen 125 (CA125) serum levels and kinetic values, velocity (CA125vel) and doubling time (CA125dt), as well as fluorodeoxyglucose ([ 18 F]FDG) positron emission tomography/computed tomography (PET/CT), in the detection of ovarian cancer recurrence. To assess the optimal cut-off for CA125, CA125vel and CA125dt to detect relapse with [ 18 F]FDG-PET/CT. A retrospective analysis was performed of 59 [ 18 F]FDG-PET/CT (48 patients) for suspected recurrence of ovarian cancer. Receiver operating characteristic (ROC) curves were plotted and area-under-the curve (AUC) statistics were computed for CA125, CA125vel and CA125dt. The results obtained in the group with normal and high (>35U/ml) CA125 levels were compared. Forty-four cases of recurrence were diagnosed (7 had CA125 ≤35U/ml), whereas 15 showed no disease. All of them were correctly catalogued by PET/CT. In ROC analysis, the discriminatory power of CA125 was relatively high (AUC 0.835) and the optimal cut-off point to reflect active disease was 23.9U/ml. The ROC analyses for the CA125vel and CA125dt showed an AUC of 0.849 and 0.728, respectively, with an optimal cut-off point of 1.96U/ml/month and 0.76 months, respectively. In patients with normal CA125 and recurrence of ovarian cancer, the CA125vel was significantly higher than in patients without recurrence (p=0.029). [ 18 F]FDG-PET/CT is more accurate than CA125 parameters in the detection of ovarian cancer recurrence. CA125 serum levels are essential; nevertheless, CA125 kinetic values must be considered to detect relapse. Particularly in patients with CA125 within normal values, in which a higher CA125vel is indicative of recurrence. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  1. Tomography

    International Nuclear Information System (INIS)

    Barrett, H.H.; Gordon, S.; Swindell, W.

    1980-01-01

    Apparatus is described for generating a two-dimensional back-projected image of a slice of an object in tomography. The apparatus uses optical techniques to perform the functions of filtering and back projection. Central to the technique is a cylindrical drum which rotates at a fast rate and whose rotational axis tilts at a slower rate. The novel method overcomes the problem of image blurring due to motion which occurs in many tomographic techniques. It also has the advantages of being less expensive and simpler compared to tomography using digital processing techniques which require fast computers. (UK)

  2. Assessment of atherosclerotic plaque activity in patients with sleep apnea using hybrid positron emission tomography/magnetic resonance imaging (PET/MRI): a feasibility study.

    Science.gov (United States)

    Kundel, Vaishnavi; Trivieri, Maria Giovanna; Karakatsanis, Nicolas A; Robson, Phillip M; Mani, Venkatesh; Kizer, Jorge R; Kaplan, Robert; Fayad, Zahi; Shah, Neomi

    2018-03-05

    Evidence suggests that the inflammatory state of an atherosclerotic plaque is important in predicting future risk of plaque rupture. This study aims to investigate the feasibility of measuring plaque inflammation in patients with obstructive sleep apnea (OSA) utilizing advanced vascular imaging - hybrid positron-emission tomography/magnetic resonance imaging (PET/MRI) with fluorodeoxyglucose (FDG) tracer-before and after continuous positive airway pressure (CPAP). Patients with newly diagnosed moderate to severe OSA underwent baseline PET/MRI for assessment of vascular inflammation of the carotid arteries and thoracic aorta prior to initiation of CPAP. Those adherent to CPAP returned for repeat imaging after 3-6 months of CPAP use. Atherosclerotic plaque activity, as measured by arterial wall FDG uptake, was calculated using target-to-background ratios (TBR) before and after CPAP. Five patients were recruited as part of a focused project. Mean age was 52 years (80% male), and mean apnea-hypopnea index (AHI) was 33. Three patients were objectively adherent with CPAP. In the pre-CPAP phase, all patients had focal FDG uptake in the carotid arteries and aorta. After CPAP, there was an average reduction in TBR of 5.5% (TBR mean ) and 6.2% (TBR max ) in carotid and aortic plaque inflammation, similar in magnitude to the reduction observed with statin therapy alone in non-OSA patients (previously reported by others). We demonstrate the feasibility of using hybrid PET/MRI to assess atherosclerotic plaque inflammation in patients with OSA before and after CPAP. Use of the vascular PET/MRI platform in patients with OSA may provide better insight into the role of OSA and its treatment in reducing atherosclerotic inflammation.

  3. Terahertz imaging and tomography as efficient instruments for testing polymer additive manufacturing objects.

    Science.gov (United States)

    Perraud, J B; Obaton, A F; Bou-Sleiman, J; Recur, B; Balacey, H; Darracq, F; Guillet, J P; Mounaix, P

    2016-05-01

    Additive manufacturing (AM) technology is not only used to make 3D objects but also for rapid prototyping. In industry and laboratories, quality controls for these objects are necessary though difficult to implement compared to classical methods of fabrication because the layer-by-layer printing allows for very complex object manufacturing that is unachievable with standard tools. Furthermore, AM can induce unknown or unexpected defects. Consequently, we demonstrate terahertz (THz) imaging as an innovative method for 2D inspection of polymer materials. Moreover, THz tomography may be considered as an alternative to x-ray tomography and cheaper 3D imaging for routine control. This paper proposes an experimental study of 3D polymer objects obtained by additive manufacturing techniques. This approach allows us to characterize defects and to control dimensions by volumetric measurements on 3D data reconstructed by tomography.

  4. An integrated high temperature environmental cell for atom probe tomography studies of gas-surface reactions: Instrumentation and results

    International Nuclear Information System (INIS)

    Dumpala, S.; Broderick, S.R.; Bagot, P.A.J.; Rajan, K.

    2014-01-01

    An integrated environmental cell has been designed and developed for the latest generation of Atom Probe Tomography LEAP™ instruments, allowing controlled exposure of samples to gases at high temperatures. Following treatment, samples can be transferred through the LEAP vacuum system for subsequent APT analysis, which provides detailed information on changes to chemical microstructures following the reactions with near-atomic resolution. A full description of the cell is presented, along with some sample results on the oxidation of aluminum and two platinum-group alloys, demonstrating the capability of combining exposure/characterization functionality in a single instrument. - Highlights: • Designed and built atom probe environmental cell for in situ reactions. • Investigated Al oxidation, and demonstrated improvement with new cell. • in situ APT analysis of Pt-alloys showed surface segregation of Rh and Ir

  5. Sensory analysis of pet foods.

    Science.gov (United States)

    Koppel, Kadri

    2014-08-01

    Pet food palatability depends first and foremost on the pet and is related to the pet food sensory properties such as aroma, texture and flavor. Sensory analysis of pet foods may be conducted by humans via descriptive or hedonic analysis, pets via acceptance or preference tests, and through a number of instrumental analysis methods. Sensory analysis of pet foods provides additional information on reasons behind palatable and unpalatable foods as pets lack linguistic capabilities. Furthermore, sensory analysis may be combined with other types of information such as personality and environment factors to increase understanding of acceptable pet foods. Most pet food flavor research is proprietary and, thus, there are a limited number of publications available. Funding opportunities for pet food studies would increase research and publications and this would help raise public awareness of pet food related issues. This mini-review addresses current pet food sensory analysis literature and discusses future challenges and possibilities. © 2014 Society of Chemical Industry.

  6. Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET/CT) Findings in an Unusual Case of Multiple Myeloma Presenting with a Large Extra-Axial Intracranial Mass.

    Science.gov (United States)

    Ayaz, Sevin; Ayaz, Ümit Yaşar

    2016-01-01

    We aimed to present unusual cranial FDG PET/CT findings of a 56-year-old female with multiple myeloma (MM). Plain CT images revealed a lytic lesion in the right parietal bone, filled with an oval-shaped, large, extra-axial, extradural, intracranial mass which measured 75×75×40 mm and had smooth borders. The right parietal lobe was compressed by the mass. The maximum standardized uptake value (SUV max ) of the mass lesion was 8.94 on FDG PET/CT images. Multiple lytic lesions with an increased uptake were also detected in other calvarial bones, in several vertebras and in the proximal left femur. After seven months, a control FDG PET/CT following radiotherapy and chemotherapy revealed almost complete regression of the right parietal extra-axial mass lesion. The number, size and metabolism of lytic lesions in other bones also decreased. FDG PET/CT was useful for an initial evaluation of MM lesions and was effective in monitoring the response of these lesions to therapy.

  7. Instrumentation

    International Nuclear Information System (INIS)

    Prieur, G.; Nadi, M.; Hedjiedj, A.; Weber, S.

    1995-01-01

    This second chapter on instrumentation gives little general consideration on history and classification of instrumentation, and two specific states of the art. The first one concerns NMR (block diagram of instrumentation chain with details on the magnets, gradients, probes, reception unit). The first one concerns precision instrumentation (optical fiber gyro-meter and scanning electron microscope), and its data processing tools (programmability, VXI standard and its history). The chapter ends with future trends on smart sensors and Field Emission Displays. (D.L.). Refs., figs

  8. Model PET Scan Activity

    Science.gov (United States)

    Strunk, Amber; Gazdovich, Jennifer; Redouté, Oriane; Reverte, Juan Manuel; Shelley, Samantha; Todorova, Vesela

    2018-05-01

    This paper provides a brief introduction to antimatter and how it, along with other modern physics topics, is utilized in positron emission tomography (PET) scans. It further describes a hands-on activity for students to help them gain an understanding of how PET scans assist in detecting cancer. Modern physics topics provide an exciting way to introduce students to current applications of physics.

  9. Comparative Study of Three Rotary Instruments for root canal Preparation using Computed Tomography

    International Nuclear Information System (INIS)

    Mohamed, A.M.E.

    2015-01-01

    Cleaning and shaping the root canal is a key to success in root canal treatment. This includes the removal of organic substrate from the root canal system by chemo mechanical methods, and the shaping of the root canal system into a continuously tapered preparation. This should be done while maintaining the original path of the root canal. Although instruments for root canal preparation have been progressively developed and optimized, a complete mechanical debridement of the root canal system is rarely achievable. One of the main reasons is the geometrical dis symmetry between the root canal and preparation instruments. Rotary instruments regardless of their type and form produce a preparation with a round outline if they are used in a simple linear filing motion, which in most of the cases do not coincide with the outline of the root canal. Root canal preparation in narrow, curved canals is a challenge even for experienced endodontists. Shaping of curved canals became more effective after the introduction of nickel-titanium (Ni-Ti) endodontic instruments. Despite the advantages of Ni-Ti rotary instruments, intra canal fracture is the most common procedural accident that occurs with these instruments during clinical use. It is a common experience between clinicians that Ni-Ti rotary instruments may undergo unexpected fracture without any visible warning, such as any previous permanent defect or deformation. Pro Taper Ni-Ti instruments were introduced with a unique design of variable taper within one instrument and continuously changing helical angles. Pro Taper rotary instruments are claimed to generate lower torque values during their use because of their modified nonradial landed cross-section that increases the cutting efficiency and reduces contact areas. On the other hand, the variable taper within one instrument is believed to reduce the ‘taper lock’ effect (torsional failure) in comparison with similarly tapered instruments. Nevertheless, Pro Taper

  10. PET imaging in multiple sclerosis

    NARCIS (Netherlands)

    Faria, Daniele de Paula; Copray, Sjef; Buchpiguel, Carlos; Dierckx, Rudi; de Vries, Erik

    Positron emission tomography (PET) is a non-invasive technique for quantitative imaging of biochemical and physiological processes in animals and humans. PET uses probes labeled with a radioactive isotope, called PET tracers, which can bind to or be converted by a specific biological target and thus

  11. Instrumentation

    International Nuclear Information System (INIS)

    Decreton, M.

    2000-01-01

    SCK-CEN's research and development programme on instrumentation aims at evaluating the potentials of new instrumentation technologies under the severe constraints of a nuclear application. It focuses on the tolerance of sensors to high radiation doses, including optical fibre sensors, and on the related intelligent data processing needed to cope with the nuclear constraints. Main achievements in these domains in 1999 are summarised

  12. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2001-04-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor.

  13. Instrumentation

    International Nuclear Information System (INIS)

    Decreton, M.

    2001-01-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor

  14. An introduction to the physics and instrumentation of positron emission tomography

    International Nuclear Information System (INIS)

    Bennett, G.W.

    1986-06-01

    Positron-emitting radionuclides permit the use of electronic collimation and thus achieve higher resolution and better sensitivity than can be obtained with gamma-emitting radiotracers. The evolution of PET imaging systems can be traced from the use of opposed collimated scanning detectors, which had all the limitations of traditional single photon imaging devices, to the present systems which surround the subject with a large volume of detector material. The improvements in system resolution now approach the theoretical limitation imposed by positron-range, and angular deviation. The use of coding permits the use of shared electronics for reading our multiple detectors, which promises to decrease the cost of PET imaging devices, at some penalty of degraded performance. Improvements in computer architectures and capabilities permit faster reconstruction of the multiple planes imaged by multi-slice imaging systems. Software for distortion correction and image processing are still under development, and the ability to map between different devices requires the coordination of efforts between different groups in the same institution. The development and validation of the mathematical models for tracer kinetic analyses will continue to occupy the attention of clinicians and scientists involved in these developments. The desire to make these devices simple and cheap enough to be used in routine patient care is occupying the attention of industry and pioneering users, but this goal has not yet been achieved. 17 refs., 15 figs., 3 tabs

  15. Tomography

    International Nuclear Information System (INIS)

    Allan, C.J.; Keller, N.A.; Lupton, L.R.; Taylor, T.; Tonner, P.D.

    1984-10-01

    Tomography is a non-intrusive imaging technique being developed at CRNL as an industrial tool for generating quantitative cross-sectional density maps of objects. Of most interest is tomography's ability to: distinguish features within complex geometries where other NDT techniques fail because of the complexity of the geometry; detect/locate small density changes/defects within objects, e.g. void fraction measurements within thick-walled vessels, shrink cavities in castings, etc.; provide quantitative data that can be used in analyses, e.g. of complex processes, or fracture mechanics; and provide objective quantitative data that can be used for (computer-based) quality assurance decisions, thereby reducing and in some cases eliminating the present subjectivity often encountered in NDT. The CRNL program is reviewed and examples are presented to illustrate the potential and the limitations of the technology

  16. Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests.

    Science.gov (United States)

    Demir, Mustafa; Toklu, Türkay; Abuqbeitah, Mohammad; Çetin, Hüseyin; Sezgin, H Sezer; Yeyin, Nami; Sönmezoğlu, Kerim

    2018-02-01

    The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated aspects were spatial resolution, sensitivity, scatter fraction, count rate performance, image quality, count loss and random events correction accuracy. The findings of this study demonstrated superior sensitivity (~ 4 folds) of PET scanner in PET/MR compared to PET/CT system. Image quality test exhibited higher contrast in PET/MR (~ 9%) compared with PET/CT. The scatter fraction of PET/MR was 43.4% at noise equivalent count rate (NECR) peak of 218 kcps and the corresponding activity concentration was 17.7 kBq/cc. Whereas the scatter fraction of PET/CT was found as 39.2% at NECR peak of 72 kcps and activity concentration of 24.3 kBq/cc. The percentage error of the random event correction accuracy was 3.4% and 3.1% in PET/MR and PET/CT, respectively. It was concluded that PET/MR system is about 4 times more sensitive than PET/CT, and the contrast of hot lesions in PET/MR was ~ 9% higher than PET/CT. These outcomes also emphasize the possibility to achieve excellent clinical PET images with low administered dose and/or a short acquisition time in PET/MR.

  17. Positron emission tomography with fluorine-deoxyglucose in sarcomas and non-sarcoma non-epithelial tumors; Utilidad del estudio PET con FDG en la evaluacion de sarcomas de diverso origen y de tumores no sarcoma-no epiteliales

    Energy Technology Data Exchange (ETDEWEB)

    Massardo, Teresa [Seccion Medicina Nuclear, Departamento de Medicina, Hospital Clinico Universidad de Chile, Santiago (Chile); Jofre, Maria Josefina; Sierralta, Maria Paulina; Canessa, Jose [Centro PET de imagenes moleculares, Hospital Militar de Santiago, Santiago (Chile); Castro, Gabriel; Berrocal, Isabel [Seccion Medicina Nuclear, Departamento de Medicina, Hospital Clinico Universidad de Chile, Santiago (Chile); Gallegos, Ivan [Departamento Anatomia Patologica, Hospital Clinico Universidad de Chile, Santiago (Chile)

    2012-07-01

    Background: The usefulness of positron emission tomography (PET) with fluorine-deoxyglucose (FDG) in sarcomas and non-sarcoma non-epithelial (NSNE) tumors is not clearly defined. Aim: To report a Chilean experience with NSNE tumors evaluated using PET with FDG. Material and Methods: Retrospective review of the database of a PET laboratory. Demographic data, indications and metabolic findings were compared with conventional imaging in 88 adults and children with diverse bone and soft tissue sarcomas as well as 24 gastrointestinal stromal tumors (GIST), 6 pleural malignant mesotheliomas in adults, and 9 medulloblastomas in children. Results: FDG showed good concordance with conventional imaging in NSNE tumors. It was helpful for staging, restaging, follow-up after treatment and for the detection of new not previously suspected lesions. Conclusions: PET with FDG could have a prognostic role and help in patient management, mainly in musculoskeletal and high grade or less differentiated sarcomas. In GIST, it was a good tool for immunotherapy control.

  18. The positron emission mammography/tomography breast imaging and biopsy system (PEM/PET): design, construction and phantom-based measurements

    Science.gov (United States)

    Raylman, Raymond R.; Majewski, Stan; Smith, Mark F.; Proffitt, James; Hammond, William; Srinivasan, Amarnath; McKisson, John; Popov, Vladimir; Weisenberger, Andrew; Judy, Clifford O.; Kross, Brian; Ramasubramanian, Srikanth; Banta, Larry E.; Kinahan, Paul E.; Champley, Kyle

    2008-02-01

    Tomographic breast imaging techniques can potentially improve detection and diagnosis of cancer in women with radiodense and/or fibrocystic breasts. We have developed a high-resolution positron emission mammography/tomography imaging and biopsy device (called PEM/PET) to detect and guide the biopsy of suspicious breast lesions. PET images are acquired to detect suspicious focal uptake of the radiotracer and guide biopsy of the area. Limited-angle PEM images could then be used to verify the biopsy needle position prior to tissue sampling. The PEM/PET scanner consists of two sets of rotating planar detector heads. Each detector consists of a 4 × 3 array of Hamamatsu H8500 flat panel position sensitive photomultipliers (PSPMTs) coupled to a 96 × 72 array of 2 × 2 × 15 mm3 LYSO detector elements (pitch = 2.1 mm). Image reconstruction is performed with a three-dimensional, ordered set expectation maximization (OSEM) algorithm parallelized to run on a multi-processor computer system. The reconstructed field of view (FOV) is 15 × 15 × 15 cm3. Initial phantom-based testing of the device is focusing upon its PET imaging capabilities. Specifically, spatial resolution and detection sensitivity were assessed. The results from these measurements yielded a spatial resolution at the center of the FOV of 2.01 ± 0.09 mm (radial), 2.04 ± 0.08 mm (tangential) and 1.84 ± 0.07 mm (axial). At a radius of 7 cm from the center of the scanner, the results were 2.11 ± 0.08 mm (radial), 2.16 ± 0.07 mm (tangential) and 1.87 ± 0.08 mm (axial). Maximum system detection sensitivity of the scanner is 488.9 kcps µCi-1 ml-1 (6.88%). These promising findings indicate that PEM/PET may be an effective system for the detection and diagnosis of breast cancer.

  19. The positron emission mammography/tomography breast imaging and biopsy system (PEM/PET): design, construction and phantom-based measurements

    Energy Technology Data Exchange (ETDEWEB)

    Raylman, Raymond R [Center for Advanced Imaging, Department of Radiology, West Virginia University, Morgantown, WV (United States); Majewski, Stan [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Smith, Mark F [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Proffitt, James [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Hammond, William [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Srinivasan, Amarnath [Center for Advanced Imaging, Department of Radiology, West Virginia University, Morgantown, WV (United States); McKisson, John [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Popov, Vladimir [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Weisenberger, Andrew [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Judy, Clifford O [Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV (United States); Kross, Brian [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Ramasubramanian, Srikanth [Center for Advanced Imaging, Department of Radiology, West Virginia University, Morgantown, WV (United States); Banta, Larry E [Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV (United States); Kinahan, Paul E [Department of Radiology, University of Washington, Seattle, WA (United States); Champley, Kyle [Department of Radiology, University of Washington, Seattle, WA (United States)

    2008-02-07

    Tomographic breast imaging techniques can potentially improve detection and diagnosis of cancer in women with radiodense and/or fibrocystic breasts. We have developed a high-resolution positron emission mammography/tomography imaging and biopsy device (called PEM/PET) to detect and guide the biopsy of suspicious breast lesions. PET images are acquired to detect suspicious focal uptake of the radiotracer and guide biopsy of the area. Limited-angle PEM images could then be used to verify the biopsy needle position prior to tissue sampling. The PEM/PET scanner consists of two sets of rotating planar detector heads. Each detector consists of a 4 x 3 array of Hamamatsu H8500 flat panel position sensitive photomultipliers (PSPMTs) coupled to a 96 x 72 array of 2 x 2 x 15 mm{sup 3} LYSO detector elements (pitch = 2.1 mm). Image reconstruction is performed with a three-dimensional, ordered set expectation maximization (OSEM) algorithm parallelized to run on a multi-processor computer system. The reconstructed field of view (FOV) is 15 x 15 x 15 cm{sup 3}. Initial phantom-based testing of the device is focusing upon its PET imaging capabilities. Specifically, spatial resolution and detection sensitivity were assessed. The results from these measurements yielded a spatial resolution at the center of the FOV of 2.01 {+-} 0.09 mm (radial), 2.04 {+-} 0.08 mm (tangential) and 1.84 {+-} 0.07 mm (axial). At a radius of 7 cm from the center of the scanner, the results were 2.11 {+-} 0.08 mm (radial), 2.16 {+-} 0.07 mm (tangential) and 1.87 {+-} 0.08 mm (axial). Maximum system detection sensitivity of the scanner is 488.9 kcps {mu}Ci{sup -1} ml{sup -1} (6.88%). These promising findings indicate that PEM/PET may be an effective system for the detection and diagnosis of breast cancer.

  20. Utilizing 18F-fluoroethyltyrosine (FET) positron emission tomography (PET) to define suspected nonenhancing tumor for radiation therapy planning of glioblastoma.

    Science.gov (United States)

    Hayes, Aimee R; Jayamanne, Dasantha; Hsiao, Edward; Schembri, Geoffrey P; Bailey, Dale L; Roach, Paul J; Khasraw, Mustafa; Newey, Allison; Wheeler, Helen R; Back, Michael

    2018-01-31

    The authors sought to evaluate the impact of 18F-fluoroethyltyrosine (FET) positron emission tomography (PET) on radiation therapy planning for patients diagnosed with glioblastoma (GBM) and the presence of suspected nonenhancing tumors compared with standard magnetic resonance imaging (MRI). Patients with GBM and contrast-enhanced MRI scans showing regions suspicious of nonenhancing tumor underwent postoperative FET-PET before commencing radiation therapy. Two clinical target volumes (CTVs) were created using pre- and postoperative MRI: MRI fluid-attenuated inversion recovery (FLAIR) sequences (CTV FLAIR ) and MRI contrast sequences with an expansion on the surgical cavity (CTV Sx ). FET-PET was used to create biological tumor volumes (BTVs) by encompassing FET-avid regions, forming BTV FLAIR and BTV Sx . Volumetric analyses were conducted between CTVs and respective BTVs using Wilcoxon signed-rank tests. The volume increase with addition of FET was analyzed with respect to BTV FLAIR and BTV Sx . Presence of focal gadolinium contrast enhancement within previously nonenhancing tumor or within the FET-avid region was noted on MRI scans at 1 and 3 months after radiation therapy. Twenty-six patients were identified retrospectively from our database, of whom 24 had demonstrable FET uptake. The median CTV FLAIR , CTV Sx , BTV FLAIR , and BTV Sx were 57.1 mL (range, 1.1-217.4), 83.6 mL (range, 27.2-275.8), 62.8 mL (range, 1.1-307.3), and 94.7 mL (range, 27.2-285.5), respectively. When FET-PET was used, there was a mean increase in volume of 26.8% from CTV FLAIR to BTV FLAIR and 20.6% from CTV Sx to BTV Sx . A statistically significant difference was noted on Wilcoxon signed-rank test when assessing volumetric change between CTV FLAIR and BTV FLAIR (P Wilcoxon signed-rank tests. FET-PET may help improve delineation of GBM in cases with a suspected nonenhancing component and reduce the risk of potential geographical miss. Copyright © 2018 American Society for Radiation

  1. Instrumentation

    International Nuclear Information System (INIS)

    Decreton, M.

    2002-01-01

    SCK-CEN's R and D programme on instrumentation involves the development of advanced instrumentation systems for nuclear applications as well as the assessment of the performance of these instruments in a radiation environment. Particular emphasis is on the use of optical fibres as umbilincal links of a remote handling unit for use during maintanance of a fusion reacor, studies on the radiation hardening of plasma diagnostic systems; investigations on new instrumentation for the future MYRRHA accelerator driven system; space applications related to radiation-hardened lenses; the development of new approaches for dose, temperature and strain measurements; the assessment of radiation-hardened sensors and motors for remote handling tasks and studies of dose measurement systems including the use of optical fibres. Progress and achievements in these areas for 2001 are described

  2. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    SCK-CEN's R and D programme on instrumentation involves the development of advanced instrumentation systems for nuclear applications as well as the assessment of the performance of these instruments in a radiation environment. Particular emphasis is on the use of optical fibres as umbilincal links of a remote handling unit for use during maintanance of a fusion reacor, studies on the radiation hardening of plasma diagnostic systems; investigations on new instrumentation for the future MYRRHA accelerator driven system; space applications related to radiation-hardened lenses; the development of new approaches for dose, temperature and strain measurements; the assessment of radiation-hardened sensors and motors for remote handling tasks and studies of dose measurement systems including the use of optical fibres. Progress and achievements in these areas for 2001 are described.

  3. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2000-07-01

    SCK-CEN's research and development programme on instrumentation aims at evaluating the potentials of new instrumentation technologies under the severe constraints of a nuclear application. It focuses on the tolerance of sensors to high radiation doses, including optical fibre sensors, and on the related intelligent data processing needed to cope with the nuclear constraints. Main achievements in these domains in 1999 are summarised.

  4. PET-PANC: multicentre prospective diagnostic accuracy and health economic analysis study of the impact of combined modality 18fluorine-2-fluoro-2-deoxy-d-glucose positron emission tomography with computed tomography scanning in the diagnosis and management of pancreatic cancer.

    Science.gov (United States)

    Ghaneh, Paula; Hanson, Robert; Titman, Andrew; Lancaster, Gill; Plumpton, Catrin; Lloyd-Williams, Huw; Yeo, Seow Tien; Edwards, Rhiannon Tudor; Johnson, Colin; Abu Hilal, Mohammed; Higginson, Antony P; Armstrong, Tom; Smith, Andrew; Scarsbrook, Andrew; McKay, Colin; Carter, Ross; Sutcliffe, Robert P; Bramhall, Simon; Kocher, Hemant M; Cunningham, David; Pereira, Stephen P; Davidson, Brian; Chang, David; Khan, Saboor; Zealley, Ian; Sarker, Debashis; Al Sarireh, Bilal; Charnley, Richard; Lobo, Dileep; Nicolson, Marianne; Halloran, Christopher; Raraty, Michael; Sutton, Robert; Vinjamuri, Sobhan; Evans, Jonathan; Campbell, Fiona; Deeks, Jon; Sanghera, Bal; Wong, Wai-Lup; Neoptolemos, John P

    2018-02-01

    Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission tomography (PET)/computed tomography (CT) adds precise anatomical localisation to functional data. The use of PET/CT may add further value to the diagnosis and staging of pancreatic cancer. To determine the incremental diagnostic accuracy and impact of PET/CT in addition to standard diagnostic work-up in patients with suspected pancreatic cancer. A multicentre prospective diagnostic accuracy and clinical value study of PET/CT in suspected pancreatic malignancy. Patients with suspected pancreatic malignancy. All patients to undergo PET/CT following standard diagnostic work-up. The primary outcome was the incremental diagnostic value of PET/CT in addition to standard diagnostic work-up with multidetector computed tomography (MDCT). Secondary outcomes were (1) changes in patients' diagnosis, staging and management as a result of PET/CT; (2) changes in the costs and effectiveness of patient management as a result of PET/CT; (3) the incremental diagnostic value of PET/CT in chronic pancreatitis; (4) the identification of groups of patients who would benefit most from PET/CT; and (5) the incremental diagnostic value of PET/CT in other pancreatic tumours. Between 2011 and 2013, 589 patients with suspected pancreatic cancer underwent MDCT and PET/CT, with 550 patients having complete data and in-range PET/CT. Sensitivity and specificity for the diagnosis of pancreatic cancer were 88.5% and 70.6%, respectively, for MDCT and 92.7% and 75.8%, respectively, for PET/CT. The maximum standardised uptake value (SUV max. ) for a pancreatic cancer diagnosis was 7.5. PET/CT demonstrated a significant improvement in relative sensitivity ( p  = 0.01) and specificity ( p  = 0.023) compared with MDCT. Incremental likelihood ratios demonstrated that PET/CT significantly improved diagnostic accuracy in all scenarios ( p  diagnostic benefit in the diagnosis of pancreatic cancer and

  5. Quantification in emission tomography

    International Nuclear Information System (INIS)

    Buvat, Irene

    2011-11-01

    The objective of this lecture is to understand the possibilities and limitations of the quantitative analysis of single photon emission computed tomography (SPECT) and positron emission tomography (PET) images. It is also to identify the conditions to be fulfilled to obtain reliable quantitative measurements from images. Content: 1 - Introduction: Quantification in emission tomography - definition and challenges; quantification biasing phenomena 2 - Main problems impacting quantification in PET and SPECT: problems, consequences, correction methods, results (Attenuation, scattering, partial volume effect, movement, un-stationary spatial resolution in SPECT, fortuitous coincidences in PET, standardisation in PET); 3 - Synthesis: accessible efficiency, know-how, Precautions, beyond the activity measurement

  6. Positron emission tomography (PET) study of the alterations in brain distribution of [{sup 11}C]dethamphetamine in methamphetamine sensitized dog

    Energy Technology Data Exchange (ETDEWEB)

    Mizugaki, Michinao; Nakamura, Hitoshi; Hishinuma, Takanori; Tomioka, Yoshihisa; Ishiwata, Shunji; Suzuki, Hideaki; Ido, Tatsuo; Iwata, Ren; Funaki, Yoshihito; Itoh, Masatoshi; Fujiwara, Takehiko; Yanai, Kazuhiko; Sato, Mitsumoto; Numachi, Yohtaro; Yoshida, Sumiko

    1995-08-01

    [{sup 11}C]Methamphetamine ([{sup 11}C]MAP) was synthesized by an automated on-line [{sup 11}C]methylation system for positron emission tomography (PET) study. We newly produced a MAP sensitized dog by repeated MAP treatment and studied the brain distribution of [{sup 11}C]MAP in the normal and the MAP sensitized dog. The maximal level of accumulation of [{sup 11}C]MAP in the sensitized dog brain was 1.4 times higher than that in the control. No difference was found in the metabolism of MAP between the two conditions. The significant increase of [{sup 11}C]MAP in the MAP sensitized brain indicates that subchronic MAP administration causes some functional change in uptake site of MAP.

  7. Blood to brain iron uptake in one Rhesus monkey using [Fe-52]-citrate and positron emission tomography (PET): influence of haloperidol

    Energy Technology Data Exchange (ETDEWEB)

    Leenders, K L [Paul Scherrer Inst., Villigen (Switzerland); [Neurology Dept., Univ. Hospital, Zuerich (Switzerland); Antonini, A; Schwarzbach, R; Smith-Jones, P; Reist, H [Paul Scherrer Inst., Villigen (Switzerland); Youdim, M [Pharmacology Dept., Technion, Haifa (Israel); Henn, V [Neurology Dept., Univ. Hospital, Zuerich (Switzerland)

    1994-12-31

    Iron is highly concentrated in the basal ganglia of the brain. The involvement of cerebral iron and its handling systems in neurodegenerative brain diseases like Parkinson`s disease and tardive dyskinesia is currently under close investigation. There is evidence from animal studies that neuroleptics can increase iron uptake into brain. This effect appeared to be due to alteration of blood-brain barrier transport by the neuroleptics, particularly chlorpromazine and haloperidol, but not clozapine. We have investigated one Rhesus monkey using positron emission tomography (PET) and [Fe-52]-citrate before and during haloperidol administration. After drug withdrawal during a period of 1.5 year the investigation procedure was repeated. The results show that in the investigated monkey haloperidol induces a reversible marked increase of iron transport across the blood brain barrier concomitant with a large increase in elimination rate of the tracer from the blood. (author).

  8. Blood to brain iron uptake in one Rhesus monkey using [Fe-52]-citrate and positron emission tomography (PET): influence of haloperidol

    International Nuclear Information System (INIS)

    Leenders, K.L.; Antonini, A.; Schwarzbach, R.; Smith-Jones, P.; Reist, H.; Youdim, M.; Henn, V.

    1994-01-01

    Iron is highly concentrated in the basal ganglia of the brain. The involvement of cerebral iron and its handling systems in neurodegenerative brain diseases like Parkinson's disease and tardive dyskinesia is currently under close investigation. There is evidence from animal studies that neuroleptics can increase iron uptake into brain. This effect appeared to be due to alteration of blood-brain barrier transport by the neuroleptics, particularly chlorpromazine and haloperidol, but not clozapine. We have investigated one Rhesus monkey using positron emission tomography (PET) and [Fe-52]-citrate before and during haloperidol administration. After drug withdrawal during a period of 1.5 year the investigation procedure was repeated. The results show that in the investigated monkey haloperidol induces a reversible marked increase of iron transport across the blood brain barrier concomitant with a large increase in elimination rate of the tracer from the blood. (author)

  9. Dual-time-point Imaging and Delayed-time-point Fluorodeoxyglucose-PET/Computed Tomography Imaging in Various Clinical Settings

    DEFF Research Database (Denmark)

    Houshmand, Sina; Salavati, Ali; Antonsen Segtnan, Eivind

    2016-01-01

    The techniques of dual-time-point imaging (DTPI) and delayed-time-point imaging, which are mostly being used for distinction between inflammatory and malignant diseases, has increased the specificity of fluorodeoxyglucose (FDG)-PET for diagnosis and prognosis of certain diseases. A gradually incr...

  10. A virtual sinogram method to reduce dental metallic implant artefacts in computed tomography-based attenuation correction for PET

    NARCIS (Netherlands)

    Abdoli, Mehrsima; Ay, Mohammad Reza; Ahmadian, Alireza; Zaidi, Habib

    Objective Attenuation correction of PET data requires accurate determination of the attenuation map (mu map), which represents the spatial distribution of linear attenuation coefficients of different tissues at 511 keV. The presence of high-density metallic dental filling material in head and neck

  11. Instrumentation

    International Nuclear Information System (INIS)

    Umminger, K.

    2008-01-01

    A proper measurement of the relevant single and two-phase flow parameters is the basis for the understanding of many complex thermal-hydraulic processes. Reliable instrumentation is therefore necessary for the interaction between analysis and experiment especially in the field of nuclear safety research where postulated accident scenarios have to be simulated in experimental facilities and predicted by complex computer code systems. The so-called conventional instrumentation for the measurement of e. g. pressures, temperatures, pressure differences and single phase flow velocities is still a solid basis for the investigation and interpretation of many phenomena and especially for the understanding of the overall system behavior. Measurement data from such instrumentation still serves in many cases as a database for thermal-hydraulic system codes. However some special instrumentation such as online concentration measurement for boric acid in the water phase or for non-condensibles in steam atmosphere as well as flow visualization techniques were further developed and successfully applied during the recent years. Concerning the modeling needs for advanced thermal-hydraulic codes, significant advances have been accomplished in the last few years in the local instrumentation technology for two-phase flow by the application of new sensor techniques, optical or beam methods and electronic technology. This paper will give insight into the current state of instrumentation technology for safety-related thermohydraulic experiments. Advantages and limitations of some measurement processes and systems will be indicated as well as trends and possibilities for further development. Aspects of instrumentation in operating reactors will also be mentioned.

  12. Effect of the prosthetic group on the pharmacologic properties of 18F-labeled rhodamine B, a potential myocardial perfusion agent for positron emission tomography (PET).

    Science.gov (United States)

    Bartholomä, Mark D; Gottumukkala, Vijay; Zhang, Shaohui; Baker, Amanda; Dunning, Patricia; Fahey, Frederic H; Treves, S Ted; Packard, Alan B

    2012-12-27

    We recently reported the development of the 2-[(18)F]fluoroethyl ester of rhodamine B as a potential positron emission tomography (PET) tracer for myocardial perfusion imaging. This compound, which was prepared using a [(18)F]fluoroethyl prosthetic group, has significant uptake in the myocardium in rats but also demonstrates relatively high liver uptake and is rapidly hydrolyzed in vivo in mice. We have now prepared (18)F-labeled rhodamine B using three additional prosthetic groups (propyl, diethylene glycol, and triethylene glycol) and found that the prosthetic group has a significant effect on the in vitro and in vivo properties of these compounds. Of the esters prepared to date, the diethylene glycol ester is superior in terms of in vitro stability and pharmacokinetics. These observations suggest that the prosthetic group plays a significant role in determining the pharmacological properties of (18)F-labeled compounds. They also support the value of continued investigation of (18)F-labeled rhodamines as PET radiopharmaceuticals for myocardial perfusion imaging.

  13. Blood flow and blood volume in the femoral heads of healthy adults according to age. Measurement with positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Kubo, Toshikazu; Kimori, Kokuto; Nakamura, Fuminori; Inoue, Shigehiro; Fujioka, Mikihiro; Ueshima, Keiichiro; Hirasawa, Yasusuke; Ushijima, Yo; Nishimura, Tsunehiko

    2001-01-01

    To deepen understanding of hemodynamics in the femoral head, i.e., the essential factor in clarifying pathogenesis of hip disorders, this study examined blood flow and blood volume in the femoral heads of healthy adults, and their changes with age, by using positron emission tomography (PET). In 16 healthy adult males (age: 20-78 years old, mean age: 42 years), blood flow was measured by means of the H 2 15 O dynamic study method, and blood volume was measured by means of the 15 O-labeled carbon monoxide bolus inhalation method. Blood flow was 1.68-6.47 ml/min/100 g (mean ±SD: 3.52±1.2), and blood volume was 1.67-6.03 ml/100 g (mean ±SD: 3.00±1.27). Blood flow significantly decreased (p<0.01) with age, and blood volume significantly increased (P<0.05). PET was useful in the measurement of blood flow and blood volume in the femoral heads. With age, physiological hemodynamic changes also increased in femoral heads. (author)

  14. A computationally inexpensive model for estimating dimensional measurement uncertainty due to x-ray computed tomography instrument misalignments

    Science.gov (United States)

    Ametova, Evelina; Ferrucci, Massimiliano; Chilingaryan, Suren; Dewulf, Wim

    2018-06-01

    The recent emergence of advanced manufacturing techniques such as additive manufacturing and an increased demand on the integrity of components have motivated research on the application of x-ray computed tomography (CT) for dimensional quality control. While CT has shown significant empirical potential for this purpose, there is a need for metrological research to accelerate the acceptance of CT as a measuring instrument. The accuracy in CT-based measurements is vulnerable to the instrument geometrical configuration during data acquisition, namely the relative position and orientation of x-ray source, rotation stage, and detector. Consistency between the actual instrument geometry and the corresponding parameters used in the reconstruction algorithm is critical. Currently available procedures provide users with only estimates of geometrical parameters. Quantification and propagation of uncertainty in the measured geometrical parameters must be considered to provide a complete uncertainty analysis and to establish confidence intervals for CT dimensional measurements. In this paper, we propose a computationally inexpensive model to approximate the influence of errors in CT geometrical parameters on dimensional measurement results. We use surface points extracted from a computer-aided design (CAD) model to model discrepancies in the radiographic image coordinates assigned to the projected edges between an aligned system and a system with misalignments. The efficacy of the proposed method was confirmed on simulated and experimental data in the presence of various geometrical uncertainty contributors.

  15. Evaluation of ambient radiation levels in positron emission tomography/computed tomography in microPET/CT laboratory; Avaliacao dos niveis de radiacao ambiental no laboratorio de tomografia por emissao de positrons acoplada a tomografia computadorizada, microPET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Sarmento, Daniele Martins

    2016-11-01

    Micro PET/CT scanner is an essential tool generally used for small animal molecular imaging. Fluorine-18-labeled fluorodeoxyglucose is the most widely used radioisotope in this technique. The present study aimed to evaluate the radiation levels in a micro PET/CT research laboratory of the Radiopharmacy Center at IPEN-CNEN / SP, in order to accomplish both national standards and international recommendations. The radioprotection team has classified the laboratory as supervised area; even this laboratory does not require the adoption of specific measures for protection and safety, should be done regular re-evaluation of the conditions of occupational exposures. Workplace monitoring and individual control assessment were carried out to ensure the radiological protection of all workers directly involved in handling the scanner. Initially, there was conducted a radiometric survey, as well as measurements of the external radiation level in the workplace and its surroundings. To achieve this goal, there were placed nine thermoluminescent dosimeters of CaSO{sub 4}:Dy in preselected locations. Monthly evaluations of the occupationally exposed individuals were carried out through the use of TL dosimeters, ported in the workers' chest. Moreover, whole body measurements were performed every six months. The study period was about two-years which started in April 2014. All tests to evaluate micro PET/CT performance were based on the standard protocol of the equipment in accordance with the standard developed by the Animal PET Standard Task Force. Present study's results demonstrated that the ambient radiation levels (ambient and effective estimated radiation dose), as well as the effective shielding equipment are both adequate. This study emphasizes that it is essential to strictly follow the principles of radioprotection in workplace, whenever researches involve radioactive unsealed sources. (author)

  16. Guide to clinical PET in oncology: Improving clinical management of cancer patients

    International Nuclear Information System (INIS)

    2008-10-01

    Positron emission tomography (PET) has an approximately 50 year-history. It was developed as a tool of medical science to quantitatively measure metabolic rates of bio-substances in vivo and in particular the number of receptors in neuroscience. Until the late 1990s PET was, in most cases, research oriented activity. In 2001, positron emission tomography/X ray computed tomography (PET/CT) hybrid imaging system became commercially available. An era of clinical PET then emerged, in which PET images were utilized for clinical practice in the treatment and diagnosis of cancer patients. PET imaging could recognize areas of abnormal metabolic behaviour of cancers in vivo, and the addition of CT imaging underlines the site of malignancy. More accurate and precise interpretation of cancer lesions can therefore be performed by PET/CT imaging than PET or CT imaging alone. Clinical PET, in particular with fluorine-18-fluorodeoxyglucose ( 18 F-FDG), has already proven itself to have considerable value in oncology. The indications include malignant lymphoma and melanoma, head and neck cancers, oesophageal cancer, breast cancer, lung cancer and colorectal cancer, and it is still being expanded. The roles of clinical PET could be for 1) preoperative staging of cancers, 2) differentiation between residual tumour and scarring, 3) demonstration of suspected recurrences, 4) monitoring response to therapy, 5) prognosis and 6) radiotherapy treatment planning. Clinical PET can be used to illustrate exactly which treatment should be applied for a cancer patient as well as where surgeons should operate and where radiation oncologists should target radiation therapy. An almost exponential rise in the introduction of clinical PET, as well as the installation of PET/CT has been seen throughout the world. Clinical PET is currently viewed as the most powerful diagnostic tool in its field. This IAEA-TECDOC presents an overview of clinical PET for cancer patients and a relevant source of

  17. A method for three-dimensional analysis of the root canal system, before and after mechanical instrumentation, using X-ray Micro-computed tomography

    DEFF Research Database (Denmark)

    Markvart, Merete; Bjørndal, Lars; Larsen, Per

    . Extracted molar teeth were embedded in resin and kept moisturized. Each root canal was instrumented with NiTi instruments to #40. The teeth were scanned before and after instrumentation, using a microCT40 micro-tomography (SCANCO Medical AG, Bassersdorf, Switzerland). The reconstructed slices were imported......Clinical studies have shown a connection between the reduction of micro-organisms in the root canal and the degree of apical enlargement. The aim of this study was to create a non-invasive 3D model for monitoring the apical enlargement in molar teeth before and after mechanical instrumentation...

  18. Determination of the dose equivalent Hp(0.07) in hands of occupationally exposed personnel in the practice of proton emission tomography (PET/CT)

    International Nuclear Information System (INIS)

    Lea, D.; Ruiz, N.; Esteves, L.

    2006-01-01

    In Venezuela recently it was implanted the Positron Emission Tomography technique (PET) with the perspective of implanting it at national level. Even when in our country practices it of nuclear medicine it exists from early of 70, there is not experience in the determination of the occupational doses by exposure to the external radiation in hands. By this reason, a concern exists in the workers of the centers of nuclear medicine where it is practiced the Positron Emission Tomography technique. In absence of the TLD dosimetry to measure dose in hands in our country, measurements of the dose equivalent of the workers of the PET national reference center were made, using a detector of hands type diode. It was determined the dose in hands in terms of dose equivalent Hp(0.07) in two work positions, that is: the corresponding to the transfer of the receiving vial of ( 18 F) FDG to the shield, quality control and uni doses division. The second work position corresponds the person in charge of administering, via intravenous, the ( 18 F) FDG. In this work it realizes the dose equivalent in hands Hp(0.07) measures in each one of the work positions before described by daily production. The informed doses correspond to a total average produced activity of 20.4 GBq (550 mCi). The results of the measurements in terms of dose equivalent in hands Hp(0.07) correspond to 2.1 ± 20% mSv in the work position of division and 0.4 ± 10% mSv in the position of injection of the radioactive material. At short term this foreseen until 4 productions per week, what means an annual dose equivalent Hp(0.07) in hands of 400 mSv approximately, without taking into account abnormal situations as its are spills of the ( 18 F) FDG in the work place. This work is the starting point so that the regulatory authority settles down, in Venezuela, dose restrictions in the PET practices and implant, in the centers of nuclear medicine, an optimization politics of this practice in conformity with the ALARA

  19. Instruments

    International Nuclear Information System (INIS)

    Buehrer, W.

    1996-01-01

    The present paper mediates a basic knowledge of the most commonly used experimental techniques. We discuss the principles and concepts necessary to understand what one is doing if one performs an experiment on a certain instrument. (author) 29 figs., 1 tab., refs

  20. Positron emission tomography

    International Nuclear Information System (INIS)

    Marchenkov, N.S.

    2000-01-01

    The foundations of the positron emission tomography (PET), widely used for the medical diagnostics, are considered. The brief description of the cyclotron for production of radionuclides, applied in the PET, the target devices for manufacturing the position emitters, the moduli for the radiopharmaceuticals synthesis (RPS) for the PET is presented. The necessity and concept of complete automation of the RPS for the PET are discussed [ru

  1. Assessment of disease activity of idiopathic pulmonary fibrosis (IPF) using FDG PET and high-resolution computed tomography (HRCT)

    International Nuclear Information System (INIS)

    Kim, Bom Sahn; Kang, Won Jun; Oh, So Won; Lee, Jeong Won; Kang, Ji Yeon; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul

    2007-01-01

    Idiopathic pulmonary fibrosis (lPF) is induced by an uncontrolled accumulation and an activation of fibroblasts. The activity of IPF can be assessed according to the degrees of fibrosis and ground glass opacity (GGO) on HRCT. However, it has been thought that FDG PET reflects activity of inflammatory disease. The aim of this study was to compare the HRCT score and FDG uptake in patients with IPF. Six patients with IPF (M: F=4: 2, age 66.513.8 y) who underwent both FDG PET-CT and HRCT were enrolled (interval=33.042.6 d). The activity of IPF was scored at the level of the 1 cm above the diaphragm on HRCT, which was thought to be standard level of lower lobe. The degree of fibrosis was scored from 0 to 5 (0: no fibrosis, 1: interlobular septal wall thickening, 2: 75%). GGO was quantified from 0 to 5 (0: no GGO, 1: = 5 % of the lobe, 2: 5- 75%). Total score of HRCT was defined as the summed score of fibrosis and GGO. Standardized uptake value (SUV) was measured on same plane of FDG PET-CT by manual drawing of region of interest (ROI). SUV ratio of lung to liver was used as a metabolic marker of IPF activity. SUV ratio had a positive correlation with fibrosis score of HRCT (r=0.727, p=0.027), but did not have a significant correlation with GGO score (r=0.228, p=0.556). SUV ratio had a better correlation with total score of HRCT (r=0.895 and p<0.001). We demonstrated that SUV ratio might reflect disease activity of IPF. SUV ratio had a positive correlation with fibrosis score or total score on HRCT. FDG PET could be used to assess disease activity of IPF

  2. Assessment of disease activity of idiopathic pulmonary fibrosis (IPF) using FDG PET and high-resolution computed tomography (HRCT)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bom Sahn; Kang, Won Jun; Oh, So Won; Lee, Jeong Won; Kang, Ji Yeon; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    Idiopathic pulmonary fibrosis (lPF) is induced by an uncontrolled accumulation and an activation of fibroblasts. The activity of IPF can be assessed according to the degrees of fibrosis and ground glass opacity (GGO) on HRCT. However, it has been thought that FDG PET reflects activity of inflammatory disease. The aim of this study was to compare the HRCT score and FDG uptake in patients with IPF. Six patients with IPF (M: F=4: 2, age 66.513.8 y) who underwent both FDG PET-CT and HRCT were enrolled (interval=33.042.6 d). The activity of IPF was scored at the level of the 1 cm above the diaphragm on HRCT, which was thought to be standard level of lower lobe. The degree of fibrosis was scored from 0 to 5 (0: no fibrosis, 1: interlobular septal wall thickening, 2: <25 % of the lobe, 3: 25-49 %, 4: 50-75 %, 5: >75%). GGO was quantified from 0 to 5 (0: no GGO, 1: = 5 % of the lobe, 2: 5-<25 %, 3: 25-49 %, 4: 50-75%, 5: >75%). Total score of HRCT was defined as the summed score of fibrosis and GGO. Standardized uptake value (SUV) was measured on same plane of FDG PET-CT by manual drawing of region of interest (ROI). SUV ratio of lung to liver was used as a metabolic marker of IPF activity. SUV ratio had a positive correlation with fibrosis score of HRCT (r=0.727, p=0.027), but did not have a significant correlation with GGO score (r=0.228, p=0.556). SUV ratio had a better correlation with total score of HRCT (r=0.895 and p<0.001). We demonstrated that SUV ratio might reflect disease activity of IPF. SUV ratio had a positive correlation with fibrosis score or total score on HRCT. FDG PET could be used to assess disease activity of IPF.

  3. PET and PET/CT in oncology: the key of diagnostic challenge

    International Nuclear Information System (INIS)

    Mortelmans, L.; Stroobants, S.; Spaepen, K.

    2004-01-01

    In this presentation authors present use of positron emission tomography (PET) in oncology. This lecture is divided to the following parts: (1) Assessment of treatment response; (2) Treatment monitoring by PET: clinical examples; (3) PET for early response assessment; (4) Use of PET in Radiotherapy planning

  4. Impact of Single-Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) and Positron Emission Tomography/Computed Tomography (PET/CT) in the Diagnosis of Traumatic Brain Injury (TBI): Case Report.

    Science.gov (United States)

    Molina-Vicenty, Irma L; Santiago-Sánchez, Michelaldemar; Vélez-Miró, Iván; Motta-Valencia, Keryl

    2016-09-01

    Traumatic brain injury (TBI) is defined as damage to the brain resulting from an external force. TBI, a global leading cause of death and disability, is associated with serious social, economic, and health problems. In cases of mild-to-moderate brain damage, conventional anatomical imaging modalities may or may not detect the cascade of metabolic changes that have occurred or are occurring at the intracellular level. Functional nuclear medicine imaging and neurophysiological parameters can be used to characterize brain damage, as the former provides direct visualization of brain function, even in the absence of overt behavioral manifestations or anatomical findings. We report the case of a 30-year-old Hispanic male veteran who, after 2 traumatic brain injury events, developed cognitive and neuropsychological problems with no clear etiology in the presence of negative computed tomography (CT) findings.

  5. Influence of instrument conditions on the evaporation behavior of uranium dioxide with UV laser-assisted atom probe tomography

    International Nuclear Information System (INIS)

    2015-01-01

    Atom probe tomography (APT) provides the ability to detect subnanometer chemical variations spatially with high accuracy. Due to its ability to spatially characterize chemistry in non-conducting materials, such as oxides, provides the opportunity to characterize stoichiometry, which strongly is tied to material performance. However, accuracy has been correlated with instrument run parameters. A systematic study of the effect of laser energy, temperature, and detection rate is performed on the evaporation behavior of a model oxide, uranium dioxide (UO 2 ). Modifying the detection rate and temperature did not affect its evaporation behavior as laser energy. It was discovered that three laser evaporation regimes are present in UO 2 . Very low laser energy produces a behavior similar to DC-field evaporation, moderate laser energy produces the desired laser assisted field evaporation and high laser energy produces thermal effects in the evaporation behavior. Laser energy had the greatest impact on evaporation and the optimal instrument condition for UO 2 was determined to be 50K, 10 pJ laser energy, 0.3% detection rate, and a 100 kHz repetition rate. These conditions provide the best combination of mass resolution, accurate stoichiometry, and evaporation behavior.

  6. Positron emission tomography clinical practice

    CERN Document Server

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

    2006-01-01

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

  7. Tomography

    International Nuclear Information System (INIS)

    Brown, B.H.; Barber, D.C.; Freeston, I.L.

    1983-01-01

    Tomography images of a body are constructed by placing a plurality of surface electrodes at spaced intervals on the body, causing currents to flow in the body (e.g. by applying a potential between each pair of electrodes in turn, or by induction), and measuring the potential between pairs of electrodes, calculating the potential expected in each case on the assumption that the body consists of a medium of uniform impedance, plotting the isopotentials corresponding to the calculated results to create a uniform image of the body, obtaining the ratio between the measured potential and the calculated potential in each case, and modifying the image in accordance with the respective ratios by increasing the assumed impedance along an isopotential in proportion to a ratio greater than unity or decreasing the assumed impedance in proportion to a ratio less than unity. The modified impedances along the isopotentials for each pair of electrodes are superimposed. The calculations are carried out using a computer and the plotting is carried out by a visual display unit and/or a print-out unit. (author)

  8. A Very High Spatial Resolution Detector for Small Animal PET

    International Nuclear Information System (INIS)

    Kanai Shah, M.S.

    2007-01-01

    Positron Emission Tomography (PET) is an in vivo analog of autoradiography and has the potential to become a powerful new tool in imaging biological processes in small laboratory animals. PET imaging of small animals can provide unique information that can help in advancement of human disease models as well as drug development. Clinical PET scanners used for human imaging are bulky, expensive and do not have adequate spatial resolution for small animal studies. Hence, dedicated, low cost instruments are required for conducting small animal studies with higher spatial resolution than what is currently achieved with clinical as well as dedicated small animal PET scanners. The goal of the proposed project is to investigate a new all solid-state detector design for small animal PET imaging. Exceptionally high spatial resolution, good timing resolution, and excellent energy resolution are expected from the proposed detector design. The Phase I project was aimed at demonstrating the feasibility of producing high performance solid-state detectors that provide high sensitivity, spatial resolution, and timing characteristics. Energy resolution characteristics of the new detector were also investigated. The goal of the Phase II project is to advance the promising solid-state detector technology for small animal PET and determine its full potential. Detectors modules will be built and characterized and finally, a bench-top small animal PET system will be assembled and evaluated

  9. Diffuse Optical Tomography for Brain Imaging: Continuous Wave Instrumentation and Linear Analysis Methods

    Science.gov (United States)

    Giacometti, Paolo; Diamond, Solomon G.

    Diffuse optical tomography (DOT) is a functional brain imaging technique that measures cerebral blood oxygenation and blood volume changes. This technique is particularly useful in human neuroimaging measurements because of the coupling between neural and hemodynamic activity in the brain. DOT is a multichannel imaging extension of near-infrared spectroscopy (NIRS). NIRS uses laser sources and light detectors on the scalp to obtain noninvasive hemodynamic measurements from spectroscopic analysis of the remitted light. This review explains how NIRS data analysis is performed using a combination of the modified Beer-Lambert law (MBLL) and the diffusion approximation to the radiative transport equation (RTE). Laser diodes, photodiode detectors, and optical terminals that contact the scalp are the main components in most NIRS systems. Placing multiple sources and detectors over the surface of the scalp allows for tomographic reconstructions that extend the individual measurements of NIRS into DOT. Mathematically arranging the DOT measurements into a linear system of equations that can be inverted provides a way to obtain tomographic reconstructions of hemodynamics in the brain.

  10. Intrasurgical Human Retinal Imaging With Manual Instrument Tracking Using a Microscope-Integrated Spectral-Domain Optical Coherence Tomography Device.

    Science.gov (United States)

    Hahn, Paul; Carrasco-Zevallos, Oscar; Cunefare, David; Migacz, Justin; Farsiu, Sina; Izatt, Joseph A; Toth, Cynthia A

    2015-07-01

    To characterize the first in-human intraoperative imaging using a custom prototype spectral-domain microscope-integrated optical coherence tomography (MIOCT) device during vitreoretinal surgery with instruments in the eye. Under institutional review board approval for a prospective intraoperative study, MIOCT images were obtained at surgical pauses with instruments held static in the vitreous cavity and then concurrently with surgical maneuvers. Postoperatively, MIOCT images obtained at surgical pauses were compared with images obtained with a high-resolution handheld spectral-domain OCT (HHOCT) system with objective endpoints, including acquisition of images acceptable for analysis and identification of predefined macular morphologic or pathologic features. Human MIOCT images were successfully obtained before incision and during pauses in surgical maneuvers. MIOCT imaging confirmed preoperative diagnoses, such as epiretinal membrane, full-thickness macular hole, and vitreomacular traction and demonstrated successful achievement of surgical goals. MIOCT and HHOCT images obtained at surgical pauses in two cohorts of five patients were comparable with greater than or equal to 80% correlation in 80% of patients. Real-time video-imaging concurrent with surgical manipulations enabled, for the first time using this device, visualization of dynamic instrument-retina interaction with targeted OCT tracking. MIOCT is successful for imaging at surgical pauses and for real-time image guidance with implementation of targeted OCT tracking. Even faster acquisition speeds are currently being developed with incorporation of a swept-source MIOCT engine. Further refinements and investigations will be directed toward continued integration for real-time volumetric imaging of surgical maneuvers. Ongoing development of seamless MIOCT systems will likely transform surgical visualization, approaches, and decision-making.

  11. 2D VS 3D imaging of brain tumours with 18F-Fluoromisonidazole (FMISO) and positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Pathmaraj, K.; Scott, A.M.; Egan, G.F.; Hannah, A.; Tauro, A.; Tochon-Danguy, A.; Sachinidis, J.; Berlangieri, S.U.; Fabinyi, G.; McKay, W.J.; Cher, L.

    1998-01-01

    Full text: 18 F-FMISO accumulates in hypoxic cells and can be used in the PET imaging of brain tumours containing viable but hypoxic cells. The limited activity (typically 130 MBq) of injected 18 F-FMISO yield poor statistics, requiring prolonged imaging in the conventional 2D mode of PET scanning. 3D (septa retracted) imaging allows for more counts to be collected over a shorter time period making it a more practical alternative. This study investigates the contrast resolution that can be obtained from 3D PET scans compared to the corresponding 2D scan. A patient recently diagnosed with brain tumour was injected with 18 -FMISO 2 hours prior to scanning and imaged supine on a 951/31R PET scanner with the head secured firmly in a head holder. The imaging protocol consisted of a 3 min emission rectilinear scan to position the brain in the FOV, a 10 min post-emission transmission scan, a 20 min 2D emission scan and a 5X10 min frames 3D emission scan. Both the 2D and 3D scans were reconstructed with filtered backprojection algorithm. The first 10 min frame of the 3D acquisition was reconstructed. The total true counts were 3 million and 6.06 million in the 2D image and 3D images respectively. The random events were 0.24 million and 0.96 million in the 2D and 3D images respectively. The Noise Equivalent Counts (NEC) were 2.2 million and 2.02 million for the 2D and 3D images respectively indicating that the 2D and 3D scans (in spite of the nominal true events being vastly different in the 2 scans) had similar Signal to Noise Ratio (SNR). Circular ROI's were defined in the tumour and the contralateral cortex in comparable transaxial slices of the 2D and 3D images. Contrast resolution of the tumour to the background was calculated as 1.4 and 1.38 in the 2D and 3D images respectively. Thus comparable contrast resolution is obtained in the brain with both 3D and 2D images, making 3D imaging a viable alternative to 2D imaging and greatly reducing imaging time. Optimum time

  12. Program standard of quality control for a system of Positron Emission Tomography-computed tomography (PET-CT) used in the Foundation Valle de Lili

    International Nuclear Information System (INIS)

    Nunez, Nathalia I.; Benavides, Sivor O.; Lopera, Wilson

    2013-01-01

    A standard protocol of quality control in the Fundacion Valle del Lili for the implementation of a multimodal scanner developed emission tomography BIOGRAPH mCT X-3R of SIEMENS ® covering routine testing, frequency, acceptance ranges necessary corrective and preventive measures to detect and correct any faults and proceed if the upper detection precision and accuracy ranges accepted deviations actions. In order to minimize errors in the planning and management of patient dose, thereby improving the quality of the diagnostic image with the dose of radiation is reasonably low as possible, consistent with the clinical use of the equipment used and the information requested diagnostic study

  13. Instrumentation and calibration methods for the multichannel measurement of phase and amplitude in optical tomography

    International Nuclear Information System (INIS)

    Nissilae, Ilkka; Noponen, Tommi; Kotilahti, Kalle; Katila, Toivo; Lipiaeinen, Lauri; Tarvainen, Tanja; Schweiger, Martin; Arridge, Simon

    2005-01-01

    In this article, we describe the multichannel implementation of an intensity modulated optical tomography system developed at Helsinki University of Technology. The system has two time-multiplexed wavelengths, 16 time-multiplexed source fibers and 16 parallel detection channels. The gain of the photomultiplier tubes (PMTs) is individually adjusted during the measurement sequence to increase the dynamic range of the system by 10 4 . The PMT used has a high quantum efficiency in the near infrared (8% at 800 nm), a fast settling time, and low hysteresis. The gain of the PMT is set so that the dc anode current is below 80 nA, which allows the measurement of phase independently of the intensity. The system allows measurements of amplitude at detected intensities down to 1 fW, which is sufficient for transmittance measurements of the female breast, the forearm, and the brain of early pre-term infants. The mean repeatability of phase and the logarithm of amplitude (ln A) at 100 MHz were found to be 0.08 deg. and 0.004, respectively, in a measurement of a 7 cm phantom with an imaging time of 5 s per source and source optical power of 8 mW. We describe a three-step method of calibrating the phase and amplitude measurements so that the absolute absorption and scatter in tissue may be measured. A phantom with two small cylindrical targets and a second phantom with three rods are measured and reconstructions made from the calibrated data are shown and compared with reconstructions from simulated data

  14. 2-[18 F]fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) findings of chronic expanding intrapericardial hematoma: a potential interpretive pitfall that mimics a malignant tumor

    Science.gov (United States)

    2013-01-01

    A 77-year-old man who had undergone mitral valve replacement 5 years previously presented with an intrapericardial mass. Computed tomography and magnetic resonance imaging showed that the mass lesion contained hematoma components. Positron-emission tomography (PET) with 2-[18 F] fluoro-2-deoxy-d-glucose (FDG) revealed uptake in the peripheral rim of the mass. These findings suggested the presence of hematoma associated with a malignant lesion. Surgical resection was performed, and the histological diagnosis was chronic expanding intrapericardial hematoma without neoplastic changes. Chronic expanding intrapericardial hematoma is a rare disease but should be considered when an expanding mass is found in a patient after cardiac surgery. The FDG-PET findings of chronic expanding hematomas, including FDG uptake in the peripheral rim of the mass as a result of inflammation, should be recognized as a potential interpretive pitfall that mimics a malignant tumor. PMID:23324446

  15. An Assessment of Early Response to Targeted Therapy via Molecular Imaging: A Pilot Study of 3′-deoxy-3′[(18F]-Fluorothymidine Positron Emission Tomography 18F-FLT PET/CT in Prostate Adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Kalevi Kairemo

    2017-04-01

    Full Text Available Fluorothymidine is a thymidine analog labeled with fluorine-18 fluorothymidine for positron emission tomography (18F-FLT-PET imaging. Thymidine is a nucleic acid that is used to build DNA. Fluorine-18 fluorothymidine (18F-FLT utilizes the same metabolic pathway as does thymidine but has a very low incidence of being incorporated into the DNA (<1%. 18F-FLT-PET could have a role in the evaluation of response to targeted therapy. We present here a pilot study where we investigated cellular metabolism and proliferation in patients with prostate cancer before and after targeted therapy. Seven patients with Stage IV prostate adenocarcinoma, candidates for targeted therapy inhibiting the hepatocyte growth factor/tyrosine-protein kinase Met (HGF/C-MET pathway, were included in this study. The HGF/C-MET pathway is implicated in prostate cancer progression, and an evaluation of the inhibition of this pathway could be valuable. 18F-FLT was performed at baseline and within four weeks post-therapy. Tumor response was assessed semi-quantitatively and using visual response criteria. The range of SUVmax for 18F-FLT at baseline in the prostate varied from 2.5 to 4.2. This study demonstrated that 18F-FLT with positron emission tomography/computerized tomography (18F-FLT PET/CT had only limited applications in the early response evaluation of prostate cancer. 18F-FLT PET/CT may have some utility in the assessment of response in lymph node disease. However, 18F-FLT PET/CT was not found to be useful in the evaluation of the prostate bed, metastatic skeletal disease, and liver disease.

  16. Dynamic neurotransmitter interactions measured with PET

    International Nuclear Information System (INIS)

    Schiffer, W.K.; Dewey, S.L.

    2001-01-01

    Positron emission tomography (PET) has become a valuable interdisciplinary tool for understanding physiological, biochemical and pharmacological functions at a molecular level in living humans, whether in a healthy or diseased state. The utility of tracing chemical activity through the body transcends the fields of cardiology, oncology, neurology and psychiatry. In this, PET techniques span radiochemistry and radiopharmaceutical development to instrumentation, image analysis, anatomy and modeling. PET has made substantial contributions in each of these fields by providing a,venue for mapping dynamic functions of healthy and unhealthy human anatomy. As diverse as the disciplines it bridges, PET has provided insight into an equally significant variety of psychiatric disorders. Using the unique quantitative ability of PET, researchers are now better able to non-invasively characterize normally occurring neurotransmitter interactions in the brain. With the knowledge that these interactions provide the fundamental basis for brain response, many investigators have recently focused their efforts on an examination of the communication between these chemicals in both healthy volunteers and individuals suffering from diseases classically defined as neurotransmitter specific in nature. In addition, PET can measure the biochemical dynamics of acute and sustained drug abuse. Thus, PET studies of neurotransmitter interactions enable investigators to describe a multitude of specific functional interactions in the human brain. This information can then be applied to understanding side effects that occur in response to acute and chronic drug therapy, and to designing new drugs that target multiple systems as opposed to single receptor types. Knowledge derived from PET studies can be applied to drug discovery, research and development (for review, see (Fowler et al., 1999) and (Burns et al., 1999)). Here, we will cover the most substantial contributions of PET to understanding

  17. Dynamic neurotransmitter interactions measured with PET

    Energy Technology Data Exchange (ETDEWEB)

    Schiffer, W.K.; Dewey, S.L.

    2001-04-02

    Positron emission tomography (PET) has become a valuable interdisciplinary tool for understanding physiological, biochemical and pharmacological functions at a molecular level in living humans, whether in a healthy or diseased state. The utility of tracing chemical activity through the body transcends the fields of cardiology, oncology, neurology and psychiatry. In this, PET techniques span radiochemistry and radiopharmaceutical development to instrumentation, image analysis, anatomy and modeling. PET has made substantial contributions in each of these fields by providing a,venue for mapping dynamic functions of healthy and unhealthy human anatomy. As diverse as the disciplines it bridges, PET has provided insight into an equally significant variety of psychiatric disorders. Using the unique quantitative ability of PET, researchers are now better able to non-invasively characterize normally occurring neurotransmitter interactions in the brain. With the knowledge that these interactions provide the fundamental basis for brain response, many investigators have recently focused their efforts on an examination of the communication between these chemicals in both healthy volunteers and individuals suffering from diseases classically defined as neurotransmitter specific in nature. In addition, PET can measure the biochemical dynamics of acute and sustained drug abuse. Thus, PET studies of neurotransmitter interactions enable investigators to describe a multitude of specific functional interactions in the human brain. This information can then be applied to understanding side effects that occur in response to acute and chronic drug therapy, and to designing new drugs that target multiple systems as opposed to single receptor types. Knowledge derived from PET studies can be applied to drug discovery, research and development (for review, see (Fowler et al., 1999) and (Burns et al., 1999)). Here, we will cover the most substantial contributions of PET to understanding

  18. The role of metabotropic glutamate receptor 5 in the pathogenesis of mood disorders and addiction:Combining preclinical evidence with human Positron Emission Tomography (PET studies

    Directory of Open Access Journals (Sweden)

    Sylvia eTerbeck

    2015-03-01

    Full Text Available In the present review, we deliver an overview of the involvement of metabotropic glutamate receptor 5 (mGluR5 activity and density in pathological anxiety, mood disorders and addiction. Specifically, we will describe mGluR5 studies in humans that employed Positron Emission Tomography (PET and combined the findings with preclinical animal research. This combined view of different methodological approaches — from basic neurobiological approaches to human studies — might give a more comprehensive and clinically relevant view of mGluR5 function in mental health than the view on preclinical data alone. We will also review the current research data on mGluR5 along the Research Domain Criteria (RDoC. Firstly, we found evidence of abnormal glutamate activity related to the positive and negative valence systems, which would suggest that antagonistic mGluR5 intervention has prominent anti-addictive, anti-depressive and anxiolytic effects. Secondly, there is evidence that mGluR5 plays in important role in systems for social functioning and the response to social stress. Finally, mGluR5’s important role in sleep homeostasis suggests that this glutamate receptor may play an important role in RDoC’s arousal and modulatory systems domain. Glutamate was previously mostly investigate in non-human studies, however initial human clinical PET research now also supports the hypothesis that, by mediating brain excitability, neuroplasticity and social cognition, abnormal metabotropic glutamate activity might predispose individuals to a broad range of psychiatric problems.

  19. Emission computed tomography

    International Nuclear Information System (INIS)

    Ott, R.J.

    1986-01-01

    Emission Computed Tomography is a technique used for producing single or multiple cross-sectional images of the distribution of radionuclide labelled agents in vivo. The techniques of Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) are described with particular regard to the function of the detectors used to produce images and the computer techniques used to build up images. (UK)

  20. New octreotide derivatives for in vivo targeting of somatostatin receptor-positive tumors for Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Maecke, H.R.; Smith-Jones, P.; Maina, T.; Stolz, B.; Albert, R.; Bruns, C.; Reist, H.

    1993-01-01

    Two new modifications of the somatostatin analog octreotide, designed to hold the gallium isotopes 67 Ga and 68 Ga (DFO-SMS) and 99m Tc (PnAO-SMS) have been synthesized and evaluated in vitro and in vivo in tumor bearing rats. DFO-SMS can be labeled with 67 Ga 3+ and 68 Ga 3+ with high specific activity within less than 30 minutes in a ''cold kit'' type formulation. The labeled conjugate is stable under physiologgical conditions. Moreover the binding affinity to somatostatin receptors on rat brain cortex membranes was shown to be retained. In vivo fast tumor localization was demonstrated and the pharmacokinetics proved to be favourable as the main excretion route was via the kidneys. First PET studies with [ 68 Ga]-DFO-SMS showed a rapid accumulation in the tumor and a residence half-life at the tumor site of about 6 hours. PnAO-SMS can be labeled with 99m Tc with high radiochemical purity. In vivo the radiotracer accumulates well in the tumor but due to its high lipohilicity, its main excretion route is via the hepatobiliary system. (orig.)

  1. PET: the importance of physicists for the clinical arena

    CERN Multimedia

    2005-01-01

    David Townsend giving a seminar at CERN on 9 February. The past few years have seen significant advances in the development of instrumentation for Positron Emission Tomography (PET). The recent appearance of combined PET and Computed Tomography (CT) scanners that can simultaneously image both anatomy and function is of particular importance. This was the main subject of "Advances in PET imaging: from physics to physician", a seminar presented at CERN by David Townsend on Wednesday 9 February  and organized by the TT and PH groups. David Townsend, who started his career at CERN in the 1970s, is now Professor at the Department of Medicine, University of Tennessee Medical Center (Knoxville, TN). Recipient of the 2004 Clinical Scientist of the Year Award, he is an internationally renowned researcher and PET physicist, with over 25 years of experience in the field. His 1999 image of the year, an award from the Society of Nuclear Medicine in the US, was produced using a combined state-of-the art PET and a true d...

  2. Single photon emission tomography in neurological studies: Instrumentation and clinical applications

    International Nuclear Information System (INIS)

    Nikkinen, P.

    1999-01-01

    One triple head and two single head gamma camera systems were used for single photon emission tomography (SPET) imaging of both patients and brain phantoms. Studies with an anatomical brain phantom were performed for evaluation of reconstruction and correction methods in brain perfusion SPET studies. The use of the triple head gamma camera system resulted in a significant increase in image contrast and resolution. This was mainly due to better imaging geometry and the use of a high resolution collimator. The conventional Chang attenuation correction was found suitable for the brain perfusion studies. In the brain perfusion studies region of interest (ROI) based semiquantitation methods were used. A ROI map based on anatomical areas was used in 70 elderly persons (age range 55-85 years) without neurological diseases and in patients suffering from encephalitis or having had a cardiac arrest. Semiquantitative reference values are presented. For the 14 patients with encephalitis the right-to-left side differences were calculated. Defect volume indexes were calculated for 64 patients with brain infarcts. For the 30 cardiac arrest patients the defect percentages and the anteroposterior ratios were used for semiquantitation. It is concluded that different semiquantitation methods are needed for the various patient groups. Age-related reference values will improve the interpretation of SPET data. For validation of the basal ganglia receptor studies measurements were performed using a cylindrical and an anatomical striatal phantom. In these measurements conventional and transmission imaging based non-uniform attenuation corrections were compared. A calibration curve was calculated for the determination of the specific receptor uptake ratio. In the phantom studies using the triple head camera the uptake ratio obtained from simultaneous transmission-emission protocol (STEP) acquisition and iterative reconstruction was closest to the true activity ratio. Conventional

  3. Single photon emission tomography in neurological studies: Instrumentation and clinical applications

    Science.gov (United States)

    Nikkinen, Paivi Helena

    One triple head and two single head gamma camera systems were used for single photon emission tomography (SPET) imaging of both patients and brain phantoms. Studies with an anatomical brain phantom were performed for evaluation of reconstruction and correction methods in brain perfusion SPET studies. The use of the triple head gamma camera system resulted in a significant increase in image contrast and resolution. This was mainly due to better imaging geometry and the use of a high resolution collimator. The conventional Chang attenuation correction was found suitable for the brain perfusion studies. In the brain perfusion studies region of interest (ROI) based semiquantitation methods were used. A ROI map based on anatomical areas was used in 70 elderly persons (age range 55-85 years) without neurological diseases and in patients suffering from encephalitis or having had a cardiac arrest. Semiquantitative reference values are presented. For the 14 patients with encephalitis the right-to-left side differences were calculated. Defect volume indexes were calculated for 64 patients with brain infarcts. For the 30 cardiac arrest patients the defect percentages and the anteroposterior ratios were used for semiquantitation. It is concluded that different semiquantitation methods are needed for the various patient groups. Age-related reference values will improve the interpretation of SPET data. For validation of the basal ganglia receptor studies measurements were performed using a cylindrical and an anatomical striatal phantom. In these measurements conventional and transmission imaging based non-uniform attenuation corrections were compared. A calibration curve was calculated for the determination of the specific receptor uptake ratio. In the phantom studies using the triple head camera the uptake ratio obtained from simultaneous transmission-emission protocol (STEP) acquisition and iterative reconstruction was closest to the true activity ratio. Conventional

  4. 64Cu radiolabeled nano-materials as bimodal contrast agent for optical imaging and Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Nonat, A.M.; Roux, A.; Yahia-Ammar, A.; Charbonniere, L.J.; Platas-Iglesias, C.; Camerle, F.

    2015-01-01

    Fluorescent nano-crystals made of semiconductor material, also called Quantum Dots, are ideal agents for long-term or real-time optical imaging. They have been found to outperform traditional organic fluorescent dyes in many ways (size-tunable optical properties, high quantum yields, high extinction coefficients, resistance to photo bleaching). We have developed a microwave method for the synthesis of highly luminescent water soluble CdTe x S 1-x nano-crystals (Φ= 53% at 600 nm). Their surface functionalization has been developed and controlled using a Nile-Red derivative as a fluorescent marker. The same coupling strategy will be used to incorporate 64 Cu-radiotracers for PET imaging at the surface of the Quantum Dots. A large variety of poly-aza-macrocyclic ligands, have been studied in order to optimize the in vivo stability of the 64 Cu-radiolabeled complexes and their efficiency as radiopharmaceuticals

  5. Methodological studies into the applicability of positron emission tomography (PET) in light-ion beam tumor therapy

    International Nuclear Information System (INIS)

    Pawelke, J.

    1995-06-01

    For reconstruction of measured activity distributions, a multiplicative iteration scheme was used which, however, does not fulfill the clinical requirement of availability of reconstructed activity distributions within a few minutes after measuring. This disadvantage was set off by the development of an empirical algorithm for determination of the 3D-distribution of the intersection points of all possible coincidence line pairs. This algorithm was then applied for the reconstruction of the positron emitter distributions measured during range measurement of light ions. For the simple, compact source distributions and small number of measured coincidences in this case, the method of intersecting point computation is better than the iterative method in that it is significantly faster and yields images of comparable quality. On the basis of these results, a PET system was set up for clinical applications at the irradiation system for experimental light-ion beam therapy at GSI Darmstadt. (orig./DG) [de

  6. Design and Construction of a Positron Emission Tomography (PET) Unit and Medical Applications with GEANT Detector Simulation Package

    Energy Technology Data Exchange (ETDEWEB)

    Karagoz, Muge [Bogazici Univ., Istanbul (Turkey)

    1998-01-01

    In order to investigate the possibility of the construction of a sample PET coincidence unit in our HEP laboratory, a setup with two face to face PMTs and two 2x8 Csi(Tl) scintillator matrices has been constructed. In this setup, 1-D projections of a pointlike 22 Na positron source at different angles have been measured. Using these projections a 2-D image has been formed. Monte Carlo studies of this setup have been implemented using the detector simulation tool in CERN program library, GEANT. Again with GEANT a sample human body is created to study the effects of proton therapy. Utilization of the simulation as a pretherapy tool is also investigated.

  7. Simultaneous emission and transmission scanning in positron emission tomography

    International Nuclear Information System (INIS)

    Satoh, Tomohiko; Tanaka, Kazumi; Kitamura, Keishi; Amano, Masaharu; Miura, Shuichi

    2001-01-01

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

  8. Automated radiochemical processing for clinical PET

    International Nuclear Information System (INIS)

    Padgett, H.C.; Schmidt, D.G.; Bida, G.T.; Wieland, B.W.; Pekrul, E.; Kingsbury, W.G.

    1991-01-01

    With the recent emergence of positron emission tomography (PET) as a viable clinical tool, there is a need for a convenient, cost-effective source of the positron emitter-labeled radiotracers labeled with carbon-11, nitrogen-13, oxygen-15, and fluorine-18. These short-lived radioisotopes are accelerator produced and thus, require a cyclotron and radiochemistry processing instrumentation that can be operated 3 in a clinical environment by competant technicians. The basic goal is to ensure safety and reliability while setting new standards for economy and ease of operation. The Siemens Radioisotope Delivery System (RDS 112) is a fully automated system dedicated to the production and delivery of positron-emitter labeled precursors and radiochemicals required to support a clinical PET imaging program. Thus, the entire RDS can be thought of as an automated radiochemical processing apparatus

  9. Time-Based Readout of a Silicon Photomultiplier (SiPM) for Time of Flight Positron Emission Tomography (TOF-PET)

    CERN Document Server

    Powolny, F; Brunner, S E; Hillemanns, H; Meyer, T; Garutti, E; Williams, M C S; Auffray, E; Shen, W; Goettlich, M; Jarron, P; Schultz-Coulon, H C

    2011-01-01

    Time of flight (TOF) measurements in positron emission tomography (PET) are very challenging in terms of timing performance, and should ideally achieve less than 100 ps FWHM precision. We present a time-based differential technique to read out silicon photomultipliers (SiPMs) which has less than 20 ps FWHM electronic jitter. The novel readout is a fast front end circuit (NINO) based on a first stage differential current mode amplifier with 20 Omega input resistance. Therefore the amplifier inputs are connected differentially to the SiPM's anode and cathode ports. The leading edge of the output signal provides the time information, while the trailing edge provides the energy information. Based on a Monte Carlo photon-generation model, HSPICE simulations were run with a 3 x 3 mm(2) SiPM-model, read out with a differential current amplifier. The results of these simulations are presented here and compared with experimental data obtained with a 3 x 3 x 15 mm(3) LSO crystal coupled to a SiPM. The measured time coi...

  10. Rational design of biophysical imaging protocols to measure the level of intensity of massive delocalized infections under severe HIV-induced immunodeficiency: configuration of novel radioimmunoscintigraphy modalities with single-photon emission tomography (SPECT) and positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Nazarea, A.D.

    1996-01-01

    single-photon emission tomography (SPECT) and positron emission tomography (PET) protocols. (author)

  11. Additional value of FDG-PET to contrast enhanced-computed tomography (CT) for the diagnosis of mediastinal lymph node metastasis in non-small cell lung cancer. A Japanese multicenter clinical study

    International Nuclear Information System (INIS)

    Kubota, Kazuo; Murakami, Koji; Inoue, Tomio; Itoh, Harumi; Saga, Tsuneo; Shiomi, Susumu; Hatazawa, Jun

    2011-01-01

    This study was a controlled multicenter clinical study to verify the diagnostic effects of additional fluorodeoxyglucose-positron emission tomography (FDG-PET) to contrast-enhanced CT for mediastinal lymph node metastasis in patients with operable non-small cell lung cancer (NSCLC). NSCLC patients with enlarged mediastinal lymph nodes (short diameter, 7-20 mm), confirmed using contrast-enhanced CT, were examined using FDG-PET to detect metastases prior to surgery. The primary endpoint was the accuracy for concomitantly used CT and FDG-PET showing the additional effects of FDG, compared with CT alone. The secondary endpoints were the clinical impact of FDG-PET on therapeutic decisions and adverse reaction from FDG administration. The images were interpreted by investigators at each institution. Moreover, blinded readings were performed by an image interpretation committee independent of the institutions. The gold standard was the pathological diagnosis determined by surgery or biopsy after PET, and patients in whom a pathological diagnosis was not obtained were excluded from the analysis. Among 99 subjects, the results for 81 subjects eligible for analysis showed that the accuracy improved from 69.1% (56/81) for CT alone to 75.3% (61/81) for CT + PET (p=0.404). These findings contributed to treatment decisions in 63.0% (51/81) of the cases, mainly with regard to the selection of the operative procedure. The results of the image interpretation committee showed that the accuracy improved from 64.2% (52/81) (95% confidence interval (CI) 52.8-74.6) for CT to 75.3% (61/81) (95% CI 64.5-84.2) for CT + PET. The accuracy for 106 mediastinal lymph nodes improved significantly from 62.3% (66/106) (95% CI 52.3-71.5) for CT to 79.2% (84/106) (95% CI 70.3-86.5) for CT + PET (p<0.05). We found that no serious adverse drug reactions appeared in any of the 99 patients who received FDG, except for transient mild outliers in the laboratory data for two patients. The addition of FDG-PET

  12. Electroplating targets for production of unique PET radionuclides

    International Nuclear Information System (INIS)

    Bui, V.; Sheh, Y.; Finn, R.

    1994-01-01

    The past decade has witnessed the applications of Positron Emission Tomography (PET) evolving from a purely research endeavour to a procedure which has specific clinical applications in the areas of cardiology, neurology and oncology. The growth of PET has been facilitated by developments in medical instrumentation and radiopharmaceutical chemistry efforts. Included in this latter effort has been the low energy accelerator production and processing of unique PET radionuclides appropriate for the radiolabeling of biomolecules i.e. monoclonal antibodies and pepetides. The development and application of electroplated targets of antimony and copper for the production of iodine-124 and gallium-66 respectively, utilizing the Memorial Sloan-Kettering Cancer Center cyclotron are examples of target design and development applicable to many medical accelerators

  13. Patterns of brown fat uptake of 18F-fluorodeoxyglucose in positron emission tomography/computed tomography scan

    International Nuclear Information System (INIS)

    Chakraborty, Dhritiman; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2015-01-01

    Fluorodeoxyglucose (FDG) positron emission tomography (PET) has become the common imaging modality in oncological practice. FDG uptake is seen in brown adipose tissue in a significant number of patients. Recognizing the uptake patterns is important for optimal FDG PET interpretation. The introduction of PET/computed tomography (PET/CT) revolutionized PET imaging, bringing much-needed anatomical information. Careful review and correlation of FDG PET images with anatomical imaging should be performed to characterize accurately any lesion having high FDG uptake

  14. Synergies between electromagnetic calorimetry and PET

    International Nuclear Information System (INIS)

    Moses, William W.

    2002-01-01

    The instrumentation used for the nuclear medical imaging technique of Positron Emission Tomography (PET) shares many features with the instrumentation used for electromagnetic calorimetry. Both fields can certainly benefit from technical advances in many common areas, and this paper discusses both the commonalties and the differences between the instrumentation needs for the two fields. The overall aim is to identify where synergistic development opportunities exist. While such opportunities exist in inorganic scintillators, photodetectors, amplification and readout electronics, and high-speed computing, it is important to recognize that while the requirements of the two fields are similar, they are not identical, and so it is unlikely that advances specific to one field can be transferred without modification to the other

  15. Molecular Imaging with Small Animal PET/CT

    DEFF Research Database (Denmark)

    Binderup, T.; El-Ali, H.H.; Skovgaard, D.

    2011-01-01

    is also described. In addition, the non-invasive nature of molecular imaging and the targets of these promising new tracers are attractive for other research areas as well, although these fields are much less explored. We present an example of an interesting research field with the application of small......Small animal positron emission tomography (PET) and computer tomography (CT) is an emerging field in pre-clinical imaging. High quality, state-of-the-art instruments are required for full optimization of the translational value of the small animal studies with PET and CT. However...... in this field of small animal molecular imaging with special emphasis on the targets for tissue characterization in tumor biology such as hypoxia, proliferation and cancer specific over-expression of receptors. The added value of applying CT imaging for anatomical localization and tumor volume measurements...

  16. Click synthesis of PET radiopharmaceuticals

    International Nuclear Information System (INIS)

    Xu Mei; Kuang Chunxiang

    2009-01-01

    Increasing attention has been focused on synthesis radiopharmaceuticals for positron emission tomography (PET). The recent years witnessed applications of click chemistry to PET radiopharmaceutical synthesis,because of its distinctive advantages including high speed,yield and stereospecificity under mild conditions. Synthesis of 18 F-labeled and 11 C-labeled radiopharmaceuticals and intermediates via click chemistry are reviewed. The future trend of click chemistry for the synthesis of PET radiopharmaceutical is prospected. (authors)

  17. Progress on dedicated animal PET

    International Nuclear Information System (INIS)

    Liu Wei

    2002-01-01

    Positron emission tomography, as the leading technology providing molecular imaging of biological processes, is widely used on living laboratory animals. High-resolution dedicated animal PET scanners have been developed. Although the dedicated animal PET faces obstacles and challenges, this advanced technology would play an important role in molecular biomedicine researches, such as diseases study, medicine development, and gene therapy

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

    International Nuclear Information System (INIS)

    Llacer, J.; Veklerov, E.; Nolan, D.; Grafton, S.T.; Mazziotta, J.C.; Hawkins, R.A.; Hoh, C.K.; Hoffman, E.J.

    1990-10-01

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

  19. PET-CT: current applications and new developments in the thorax.

    Science.gov (United States)

    Erasmus, Jeremy J; Mawlawi, Osama; Howard, Brandon; Patz, Edward F

    2014-02-01

    Positron emission tomography computed tomography(PET-CT) imaging has emerged as an essential clinical diagnostic tool in the evaluation of thoracic abnormalities. Currently, its primary role is for tumor imaging; it helps to differentiate benign from malignant nodules, stage tumors, determine response, and follow patients after therapy is complete. It has also been used for nononcologic diseases, but the indications are less well defined. PET is a fundamental component of the molecular imaging initiative, and as new more specific imaging probes and better instrumentation are developed, PET-CT is certain to improve diagnostic accuracy and become even more integrated into the imaging armamentarium. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  20. Volumetric analysis of hand, reciprocating and rotary instrumentation techniques in primary molars using spiral computed tomography: An in vitro comparative study.

    Science.gov (United States)

    Jeevanandan, Ganesh; Thomas, Eapen

    2018-01-01

    This present study was conducted to analyze the volumetric change in the root canal space and instrumentation time between hand files, hand files in reciprocating motion, and three rotary files in primary molars. One hundred primary mandibular molars were randomly allotted to one of the five groups. Instrumentation was done using Group I; nickel-titanium (Ni-Ti) hand file, Group II; Ni-Ti hand files in reciprocating motion, Group III; Race rotary files, Group IV; prodesign pediatric rotary files, and Group V; ProTaper rotary files. The mean volumetric changes were assessed using pre- and post-operative spiral computed tomography scans. Instrumentation time was recorded. Statistical analysis to access intergroup comparison for mean canal volume and instrumentation time was done using Bonferroni-adjusted Mann-Whitney test and Mann-Whitney test, respectively. Intergroup comparison of mean canal volume showed statistically significant difference between Groups II versus IV, Groups III versus V, and Groups IV versus V. Intergroup comparison of mean instrumentation time showed statistically significant difference among all the groups except Groups IV versus V. Among the various instrumentation techniques available, rotary instrumentation is the considered to be the better instrumentation technique for canal preparation in primary teeth.

  1. The use of median polish (MP) for the daily quality assurance of a multiplanar positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Kearfott, K.J.; Thaler, H.T.; Dukes, A.L.; Carmichael, P.G.

    1984-01-01

    Daily sensitivity data were obtained for The Cyclotron Corporation PC 4600 Neuro-PET on an almost daily basis for 3 months during installation and for 6 months during full clinical utilization. A uniform phantom was filled with a known concentration of isotope (typically 0.14 μCi/cc Ga-68), centered in the scanner port using crossed lasers and scanned. Images were reconstructed using analytic attenuation correction for a total of 4-5 million uncorrected coincidence counts/plane (random/true <2%). The entire quality assurance procedure, with analysis, was performed within 1.5 hr. The resulting sensitivities for various planes and days can be represented as a two-way table. Median polish (MP) is a statistically robust technique for looking at structured or cross-classified data to identify trends and outliers by iteratively computing medians of rows and columns in order to obtain a linear fit to the data. Outliers (both for variant planes, experiments and combinations) were immediately discernible when MP was used to analyze the sensitivity data. While the standard deviations of the residuals in the MP table ranged from 2.1% to 18.5% during machine installation, subsequent variations were smaller (0.6-4.2%), and the number of outliers was substantially reduced. In addition, MP was useful in pointing out a sudden change in machine behavior related to a high-voltage power supply problem. Systematic drifts in sensitivity and reliability of both individual planes and of the entire machine are readily revealed by MP, which is therefore very useful in monitoring performance and in directing maintenance

  2. SPECT and PET imaging in epilepsy

    International Nuclear Information System (INIS)

    Semah, F.

    2007-01-01

    Positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging are very useful for the management of patients with medically refractory partial epilepsy. Presurgical evaluation of patients with medically refractory partial epilepsy often included PET imaging using FDG. The use of SPECT in these patients adds some more information and gives the clinicians the possibility of having ictal imaging. Furthermore, PET and SPECT imaging are performed to better understand the pathophysiology of epilepsy. (authors)

  3. Comparison of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) in corticosteroid-naive patients with conduction system disease due to cardiac sarcoidosis

    Energy Technology Data Exchange (ETDEWEB)

    Ohira, Hiroshi; Birnie, David H.; Mc Ardle, Brian; Dick, Alexander; Klein, Ran; Renaud, Jennifer; DeKemp, Robert A.; Davies, Ross; Hessian, Renee; Liu, Peter; Nery, Pablo B. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); Pena, Elena; Dennie, Carole [The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada); Bernick, Jordan; Wells, George A. [University of Ottawa Heart Institute, Cardiovascular Research Methods Center, Ottawa, ON (Canada); Leung, Eugene [The Ottawa Hospital, Division of Nuclear Medicine, Department of Medicine, Ottawa, Ontario (Canada); Yoshinaga, Keiichiro [Hokkaido University School of Medicine, Department of Molecular Imaging, Hokkaido (Japan); Tsujino, Ichizo; Sato, Takahiro; Nishimura, Masaharu [Hokkaido University School of Medicine, First Department of Medicine, Hokkaido (Japan); Manabe, Osamu; Tamaki, Nagara [Hokkaido University School of Medicine, Department of Nuclear Medicine, Hokkaido (Japan); Oyama-Manabe, Noriko [Hokkaido University Hospital, Diagnostic and Interventional Radiology, Hokkaido (Japan); Ruddy, Terrence D.; Beanlands, Rob S.B. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada); The Ottawa Hospital, Division of Nuclear Medicine, Department of Medicine, Ottawa, Ontario (Canada); Chow, Benjamin J.W. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada)

    2016-02-15

    Cardiac sarcoidosis (CS) is a cause of conduction system disease (CSD). {sup 18}F-Fluorodeoxyglucose-positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) are used for detection of CS. The relative diagnostic value of these has not been well studied. The aim was to compare these imaging modalities in this population. We recruited steroid-naive patients with newly diagnosed CSD due to CS. All CS patients underwent both imaging studies within 12 weeks of each other. Patients were classified into two groups: group A with chronic mild CSD (right bundle branch block and/or axis deviation), and group B with new-onset atrioventricular block (AVB, Mobitz type II or third-degree AVB). Thirty patients were included. Positive findings on both imaging studies were seen in 72 % of patients (13/18) in group A and in 58 % of patients (7/12) in group B. The remainder (28 %) of the patients in group A were positive only on CMR. Of the patients in group B, 8 % were positive only on CMR and 33 % were positive only on FDG PET. Patients in group A were more likely to be positive only on CMR, and patients in group B were more likely to be positive only on FDG PET (p = 0.02). Patients in group B positive only on FDG PET underwent CMR earlier relative to their symptomatology than patients positive only on CMR (median 7.0, IQR 1.5 - 34.3, vs. 72.0, IQR 25.0 - 79.5 days; p = 0.03). The number of positive FDG PET and CMR studies was different in patients with CSD depending on their clinical presentation. This study demonstrated that CMR can adequately detect cardiac involvement associated with chronic mild CSD. In patients presenting with new-onset AVB and a negative CMR study, FDG PET may be useful for detecting cardiac involvement due to CS. (orig.)

  4. Positron emission tomography

    International Nuclear Information System (INIS)

    Chandrasekhar, Preethi; Himabindu, Pucha

    2000-01-01

    Positron Emission Tomography (PET) is a non-invasive nuclear imaging technique used to study different molecular pathways and anatomical structures. PET has found extensive applications in various fields of medicine viz. cardiology, oncology, psychiatry/psychology, neuro science and pulmonology. This study paper basically deals with the physics, chemistry and biology behind the PET technique. It discusses the methodology for generation of the radiotracers responsible for emission of positrons and the annihilation and detection techniques. (author)

  5. Positron emission tomography

    International Nuclear Information System (INIS)

    Dvorak, O.

    1989-01-01

    The principle is briefly described of positron emission tomography, and its benefits and constraints are listed. It is emphasized that positron emission tomography (PET) provides valuable information on metabolic changes in the organism that are otherwise only very difficult to obtain, such as brain diagnosis including relationships between mental disorders and the physiology and pathophysiology of the brain. A PET machine is to be installed in Czechoslovakia in the near future. (L.O.)

  6. PET-Probe: Evaluation of Technical Performance and Clinical Utility of a Handheld High-Energy Gamma Probe in Oncologic Surgery.

    Science.gov (United States)

    Gulec, Seza A; Daghighian, Farhad; Essner, Richard

    2016-12-01

    Positron emission tomography (PET) has become an invaluable part of patient evaluation in surgical oncology. PET is less than optimal for detecting lesions PET-positive lesions can be challenging as a result of difficulties in surgical exposure. We undertook this investigation to assess the utility of a handheld high-energy gamma probe (PET-Probe) for intraoperative identification of 18 F-deoxyglucose (FDG)-avid tumors. Forty patients underwent a diagnostic whole-body FDG-PET scan for consideration for surgical exploration and resection. Before surgery, all patients received an intravenous injection of 7 to 10 mCi of FDG. At surgery, the PET-Probe was used to determine absolute counts per second at the known tumor site(s) demonstrated by whole-body PET and at adjacent normal tissue (at least 4 cm away from tumor-bearing sites). Tumor-to-background ratios were calculated. Thirty-two patients (80%) underwent PET-Probe-guided surgery with therapeutic intent in a recurrent or metastatic disease setting. Eight patients underwent surgery for diagnostic exploration. Anatomical locations of the PET-identified lesions were neck and supraclavicular (n = 8), axilla (n = 5), groin and deep iliac (n = 4), trunk and extremity soft tissue (n = 3), abdominal and retroperitoneal (n = 19), and lung (n = 2). PET-Probe detected all PET-positive lesions. The PET-Probe was instrumental in localization of lesions in 15 patients that were not immediately apparent by surgical exploration. The PET-Probe identified all lesions demonstrated by PET scanning and, in selected cases, was useful in localizing FDG-avid disease not seen with conventional PET scanning.

  7. Improvement of depressive symptoms in patients with moderate-to-severe psoriasis treated with ustekinumab: an open label trial validated using beck depression inventory, Hamilton depression rating scale measures and 18fluorodeoxyglucose (FDG) positron emission tomography (PET).

    Science.gov (United States)

    Kim, Seong-Jang; Park, Min-Young; Pak, Kyoungjune; Han, Junhee; Kim, Gun-Wook; Kim, Hoon-Soo; Ko, Hyun-Chang; Kim, Moon-Bum; Kim, Byung-Soo

    2018-05-07

    Psoriasis is a chronic skin disease associated with psychiatric co-morbidities, especially depression. Early detection of psychological vulnerability in patients with psoriasis seems to be of great clinical importance and significantly impacts the quality of life of the patients. We sought to clarify the association between psoriasis and depressive symptoms in patients with moderate-to-severe psoriasis, and to determine the risk factors for depressive symptoms and analyze the effect of ustekinumab on the symptoms. We also aimed to evaluate the changes in glucose metabolism using 18 fluorodeoxyglucose (FDG) positron emission tomography (FDG-PET). Fifteen patients with moderate-to-severe psoriasis scheduled to be treated with ustekinumab were enrolled. At baseline and after achieving a 75% reduction in the Psoriasis Area and Severity Index (PASI) score (PASI75), all patients underwent a psychiatric interview and FDG-PET. Fifteen healthy volunteers were enrolled for comparison. Patients with moderate-to-severe psoriasis were more depressed than those in the control group were (p Inventory and Hamilton Depression Rating Scale psychiatric interviews (p < .05). However, FDG-PET of the brain showed no significant difference before and after PASI75 achievement using ustekinumab injection. Patients with moderate-to-severe psoriasis are at an increased risk for depressive symptoms, and treatment with ustekinumab may be beneficial. FDG-PET does not reflect the changes in depressive symptoms in such patients.

  8. Topography of pulmonary structure and function in man using positron emission tomography (PET) with special reference to methodology and normal physiology

    International Nuclear Information System (INIS)

    Brundin, L.H.

    1992-01-01

    Positron emission tomography (PET) allows regional quantification of specific tracer compounds to be made within a tomographic slice of the body. The present thesis which is methodological and descriptive, centers on in vivo measurements of regional lung compartments (gas, red cells, plasma and extravascular tissue) and ventilation and blood flow in normal subjects. A method of measuring regional lung hematocrit (rH) was developed and rH was found to be found to be 90% of the peripheral hematocrit in normal subjects. No significant regional variations within the lung fields were found in normal subjects or in patients with anemia or pneumonia, which enables the pulmonary whole blood volume to be regionally quantified using a single vascular tracer. This allowed a deeper examination of the interrelationship between the different lung compartments and their variation in the gravity dependent axis and during hyperinflation. Smokers were found to have higher extravascular density than non-smokers. By combining measurement of ventilation and . V A / . Q, methods were developed to 1. correct the measured . V A / . Q for incomplete equilibrium of 13 N within the alveolar space. 2. calculate regional pulmonary perfusion. By further combining these measurements with measurements of vascular and extravascular lung volumes 1. relationship between ventilation and vascular and extravascular volumes were explored and found to be consistent with the theory that ventilation is determined by the elastic properties of lung tissue and 2. relationships between blood flow and blood volume (transit times) were investigated. We conclude that blood volume plays a significant role in the matching of ventilation and perfusion and that blood flow is fairly well matched by blood volumes, thus reducing the gravitational impact on capillary transit time and hematocrit ratio which might be of rheological importance. (au)

  9. What do we measure in oncology PET?

    Energy Technology Data Exchange (ETDEWEB)

    Pak, Kyoung June; Kim, Seong Jang [Dept. of Nuclear Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan (Korea, Republic of)

    2017-09-15

    Positron emission tomography (PET) has come to the practice of oncology. It is known that {sup 18}F-fluorodeoxyglucose (FDG) PET is more sensitive for the assessment of treatment response than conventional imaging. In addition, PET has an advantage in the use of quantitative analysis of the study. Nowadays, various PET parameters are adopted in clinical settings. In addition, a wide range of factors has been known to be associated with FDG uptake. Therefore, there has been a need for standardization and harmonization of protocols and PET parameters. We will introduce PET parameters and discuss major issues in this review.

  10. Combined PET/MRI

    DEFF Research Database (Denmark)

    Bailey, D. L.; Pichler, B. J.; Gückel, B.

    2015-01-01

    This paper summarises key themes and discussions from the 4th international workshop dedicated to the advancement of the technical, scientific and clinical applications of combined positron emission tomography (PET)/magnetic resonance imaging (MRI) systems that was held in Tübingen, Germany, from...

  11. WE-G-BRF-06: Positron Emission Tomography (PET)-Guided Dynamic Lung Tumor Tracking for Cancer Radiotherapy: First Patient Simulations

    International Nuclear Information System (INIS)

    Yang, J; Loo, B; Graves, E; Yamamoto, T; Keall, P

    2014-01-01

    Purpose: PET-guided dynamic tumor tracking is a novel concept of biologically targeted image guidance for radiotherapy. A dynamic tumor tracking algorithm based on list-mode PET data has been developed and previously tested on dynamic phantom data. In this study, we investigate if dynamic tumor tracking is clinically feasible by applying the method to lung cancer patient PET data. Methods: PET-guided tumor tracking estimates the target position of a segmented volume in PET images reconstructed continuously from accumulated coincidence events correlated with external respiratory motion, simulating real-time applications, i.e., only data up to the current time point is used to estimate the target position. A target volume is segmented with a 50% threshold, consistently, of the maximum intensity in the predetermined volume of interest. Through this algorithm, the PET-estimated trajectories are quantified from four lung cancer patients who have distinct tumor location and size. The accuracy of the PET-estimated trajectories is evaluated by comparing to external respiratory motion because the ground-truth of tumor motion is not known in patients; however, previous phantom studies demonstrated sub-2mm accuracy using clinically derived 3D tumor motion. Results: The overall similarity of motion patterns between the PET-estimated trajectories and the external respiratory traces implies that the PET-guided tracking algorithm can provide an acceptable level of targeting accuracy. However, there are variations in the tracking accuracy between tumors due to the quality of the segmentation which depends on target-to-background ratio, tumor location and size. Conclusion: For the first time, a dynamic tumor tracking algorithm has been applied to lung cancer patient PET data, demonstrating clinical feasibility of real-time tumor tracking for integrated PET-linacs. The target-to-background ratio is a significant factor determining accuracy: screening during treatment planning would

  12. Estudo do metabolismo da glicose na tuberculose pulmonar ativa utilizando a tomografia por emissão de pósitrons (18F-FDG PET Evaluation of glucose metabolism in active lung tuberculosis by positron-emission tomography (18F-FDG PET

    Directory of Open Access Journals (Sweden)

    SIDNEY BOMBARDA

    2002-09-01

    Full Text Available Os métodos de imagem utilizados na avaliação da tuberculose pulmonar incluem a radiografia e a tomografia computadorizada do tórax. As imagens obtidas pelos métodos de medicina nuclear permitem estudos funcionais e metabólicos dos órgãos de interesse, através do uso de radiofármacos específicos. Alterações do metabolismo da glicose podem ser detectadas pela tomografia por emissão de pósitrons (PET utilizando-se o 18F-fluorodesoxiglicose (18F-FDG. Essas alterações estão presentes nas doenças neoplásicas, inflamatórias e infecciosas. A tuberculose é uma doença granulomatosa causada pelo Mycobacterium tuberculosis, que se utiliza de glicose como fonte de energia. Objetivo: O estudo do metabolismo da glicose na tuberculose pulmonar através da PET e sua comparação com a tomografia computadorizada de tórax. Material e métodos: Foram avaliados 20 pacientes portadores de tuberculose pulmonar. Todos foram submetidos à PET e à tomografia computadorizada de tórax, em até 30 dias após o início do tratamento. Resultados: Todos os pacientes apresentaram captação positiva do 18F-FDG na PET. Na tomografia computadorizada do tórax, todos os pacientes apresentaram sinais compatíveis com atividade de tuberculose. A sensibilidade dos dois métodos foi de 100%. Houve concordância entre os achados do 18F-FDG PET e da tomografia computadorizada (K = 0,27 e p Current methods to evaluate lung tuberculosis include chest radiography and computed tomography. Nuclear medicine imaging techniques are performed after administration of specific radiopharmaceuticals that accumulate in the organs of interest. Alterations of glucose metabolism can be observed by positron-emission tomography, using 18F-fluorodeoxyglucose (18F-FDG PET. These findings are present in the neoplasms, but also in inflammatory and infectious diseases. Tuberculosis is a granulomatous disease caused by Mycobacterium tuberculosis , that uses glucose as an energy source

  13. SPECT og PET i neurobiologien

    DEFF Research Database (Denmark)

    Paulson, O.B.; Lassen, N.A.

    1997-01-01

    PET (positron emission tomography) and SPECT (single photon emission computed tomography) are isotopic methods in which the distribution is registered of radiolabelled tracers given in such small amounts that they are without effect on the organism or the organism's disposal of them. Thus, a series...

  14. Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions

    International Nuclear Information System (INIS)

    Coelho, Marcus Vinicius Cavalcante

    1998-01-01

    In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author)

  15. Recent developments and future trends in nuclear medicine instrumentation

    International Nuclear Information System (INIS)

    Zaidi, H.

    2006-01-01

    Molecular imaging using high-resolution single-photon emission computed tomography (SPECT) and positron emission tomography (PET) has advanced elegantly and has steadily gained importance in the clinical and research arenas. Continuous efforts to integrate recent research findings for the design of different geometries and various detector technologies of SPECT and PET cameras have become the goal of both the academic community and nuclear medicine industry. As PET has recently become of more interest for clinical practice, several different design trends seem to have developed. Systems are being designed for ''low cost'' clinical applications, very high-resolution research applications (including small-animal imaging), and just about everywhere in-between. The development of dual-modality imaging systems has revolutionized the practice of nuclear medicine. The major advantage being that SPECT/PET data are intrinsically aligned to anatomical information from the X-ray computed tomography (CT), without the use of external markers or internal landmarks. On the other hand, combining PET with magnetic resonance imaging (MRI) technology is scientifically more challenging owing to the strong magnetic fields. Nevertheless, significant progress has been made resulting in the design of a prototype small animal PET scanner coupled to three multichannel photomultipliers via optical fibers, so that the PET detector can be operated within a conventional MR system. Thus, many different design paths are being pursued - which ones are likely to be the main stream of future commercial systems? It will be interesting, indeed, to see which technologies become the most popular in the future. This paper briefly summarizes state-of-the art developments in nuclear medicine instrumentation. Future prospects will also be discussed. (orig.)

  16. Positron emission tomography study on pancreatic somatostatin receptors in normal and diabetic rats with {sup 68}Ga-DOTA-octreotide: A potential PET tracer for beta cell mass measurement

    Energy Technology Data Exchange (ETDEWEB)

    Sako, Takeo [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Hasegawa, Koki; Nishimura, Mie; Kanayama, Yousuke; Wada, Yasuhiro; Hayashinaka, Emi; Cui, Yilong; Kataoka, Yosky [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Senda, Michio [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Watanabe, Yasuyoshi, E-mail: yywata@riken.jp [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan)

    2013-12-06

    Highlights: •PET images showed high uptake of {sup 68}Ga-DOTA-octreotide in the normal pancreas. •{sup 68}Ga-DOTA-octreotide specifically binds to somatostatin receptors in the pancreas. •The pancreatic uptake of {sup 68}Ga-DOTA-octreotide was decreased in the diabetic rats. •{sup 68}Ga-DOTA-octreotide could be a candidate PET probe to measure the beta cell mass. -- Abstract: Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, and the loss or dysfunction of pancreatic beta cells has been reported before the appearance of clinical symptoms and hyperglycemia. To evaluate beta cell mass (BCM) for improving the detection and treatment of DM at earlier stages, we focused on somatostatin receptors that are highly expressed in the pancreatic beta cells, and developed a positron emission tomography (PET) probe derived from octreotide, a metabolically stable somatostatin analog. Octreotide was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a chelating agent, and labeled with {sup 68}Gallium ({sup 68}Ga). After intravenous injection of {sup 68}Ga-DOTA-octreotide, a 90-min emission scan of the abdomen was performed in normal and DM model rats. The PET studies showed that {sup 68}Ga-DOTA-octreotide radioactivity was highly accumulated in the pancreas of normal rats and that the pancreatic accumulation was significantly reduced in the rats administered with an excess amount of unlabeled octreotide or after treatment with streptozotocin, which was used for the chemical induction of DM in rats. These results were in good agreement with the ex vivo biodistribution data. These results indicated that the pancreatic accumulation of {sup 68}Ga-DOTA-octreotide represented specific binding to the somatostatin receptors and reflected BCM. Therefore, PET imaging with {sup 68}Ga-DOTA-octreotide could be a potential tool for evaluating BCM.

  17. 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

  18. 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

  19. The use of 18F-Fluoro-deoxy-glucose positron emission tomography (18F-FDG PET as a non-invasive pharmacodynamic biomarker to determine the minimally pharmacologically active dose of AZD8835, a novel PI3Kα inhibitor.

    Directory of Open Access Journals (Sweden)

    Juliana Maynard

    Full Text Available The phosphatidyl inositol 3 kinase (PI3K, AKT and mammalian target of rapamycin (mTOR signal transduction pathway is frequently de-regulated and activated in human cancer and is an important therapeutic target. AZD8835 is a PI3K inhibitor, with selectivity against PI3K α and δ isoforms, which is currently in Phase 1 clinical trials. 18F-Fluoro-deoxy-glucose positron emission tomography (18F-FDG PET is a non-invasive pharmacodynamic imaging biomarker that has become an integral part of drug development. It has been used widely with PI3K inhibitors both clinically and pre-clinically because of the role of the PI3K pathway in glucose metabolism. In this study we investigated the potential of 18F-FDG PET as a non-invasive pharmacodynamic biomarker for AZD8835. We sought to understand if 18F-FDG PET could determine the minimally effective dose of AZD8835 and correlate with other pharmacodynamic biomarkers for validation of its use in clinical development. 18F-FDG PET scans were performed in nude mice in the BT474C breast xenograft model. Mice were fasted prior to imaging and static 18F-FDG PET was performed. Treatment groups received AZD8835 by oral gavage at a dose volume of 10ml/kg. Treatment groups received either 3, 6, 12.5, 25 or 50mg/kg AZD8835. Tumour growth was monitored throughout the study, and at the end of the imaging procedure, tumours were taken and a full pharmacodynamic analysis was performed.Results showed that AZD8835 reduced 18F-FDG uptake at a dose of 12.5, 25 and 50mg/kg with no significant reduction at doses of 3 and 6mg/kg. These results were consistent with other pharmacodynamics biomarkers measured and show 18F-FDG PET as a sensitive biomarker with the ability to determine the minimal effective dose of AZD8835.Our pre-clinical studies support the use of 18F-FDG PET imaging as a sensitive and non- invasive pharmacodynamic biomarker (understanding the role of PI3K signalling in glucose uptake for AZD8835 with a decrease in 18

  20. Improving PET spatial resolution and detectability for prostate cancer imaging

    International Nuclear Information System (INIS)

    Bal, H; Guerin, L; Casey, M E; Conti, M; Eriksson, L; Michel, C; Fanti, S; Pettinato, C; Adler, S; Choyke, P

    2014-01-01

    Prostate cancer, one of the most common forms of cancer among men, can benefit from recent improvements in positron emission tomography (PET) technology. In particular, better spatial resolution, lower noise and higher detectability of small lesions could be greatly beneficial for early diagnosis and could provide a strong support for guiding biopsy and surgery. In this article, the impact of improved PET instrumentation with superior spatial resolution and high sensitivity are discussed, together with the latest development in PET technology: resolution recovery and time-of-flight reconstruction. Using simulated cancer lesions, inserted in clinical PET images obtained with conventional protocols, we show that visual identification of the lesions and detectability via numerical observers can already be improved using state of the art PET reconstruction methods. This was achieved using both resolution recovery and time-of-flight reconstruction, and a high resolution image with 2 mm pixel size. Channelized Hotelling numerical observers showed an increase in the area under the LROC curve from 0.52 to 0.58. In addition, a relationship between the simulated input activity and the area under the LROC curve showed that the minimum detectable activity was reduced by more than 23%. (paper)

  1. Development of a SiPM-based PET imaging system for small animals

    International Nuclear Information System (INIS)

    Lu, Yanye; Yang, Kun; Zhou, Kedi; Zhang, Qiushi; Pang, Bo; Ren, Qiushi

    2014-01-01

    Advances in small animal positron emission tomography (PET) imaging have been accelerated by many new technologies such as the successful incorporation of silicon photomultiplier (SiPM). In this paper, we have developed a compact, lightweight PET imaging system that is based on SiPM detectors for small animals imaging, which could be integrated into a multi-modality imaging system. This PET imaging system consists of a stationary detector gantry, a motor-controlled animal bed module, electronics modules, and power supply modules. The PET detector, which was designed as a multi-slice circular ring geometry of 27 discrete block detectors, is composed of a cerium doped lutetium–yttrium oxyorthosilicate (LYSO) scintillation crystal and SiPM arrays. The system has a 60 mm transaxial field of view (FOV) and a 26 mm axial FOV. Performance tests (e.g. spatial resolution, energy resolution, and sensitivity) and phantom and animal imaging studies were performed to evaluate the imaging performance of the PET imaging system. The performance tests and animal imaging results demonstrate the feasibility of an animal PET system based on SiPM detectors and indicate that SiPM detectors can be promising photodetectors in animal PET instrumentation development

  2. Development of a SiPM-based PET imaging system for small animals

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yanye [Department of Biomedicine and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Yang, Kun, E-mail: yangkun9999@hotmail.com [Department of Control Technology and Instrumentation, College of Quality and Technical Supervision, Hebei University, Baoding, 071000 (China); Zhou, Kedi; Zhang, Qiushi; Pang, Bo [Department of Biomedicine and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Ren, Qiushi, E-mail: renqsh@coe.pku.edu.cn [Department of Biomedicine and Engineering, College of Engineering, Peking University, Beijing 100871 (China)

    2014-04-11

    Advances in small animal positron emission tomography (PET) imaging have been accelerated by many new technologies such as the successful incorporation of silicon photomultiplier (SiPM). In this paper, we have developed a compact, lightweight PET imaging system that is based on SiPM detectors for small animals imaging, which could be integrated into a multi-modality imaging system. This PET imaging system consists of a stationary detector gantry, a motor-controlled animal bed module, electronics modules, and power supply modules. The PET detector, which was designed as a multi-slice circular ring geometry of 27 discrete block detectors, is composed of a cerium doped lutetium–yttrium oxyorthosilicate (LYSO) scintillation crystal and SiPM arrays. The system has a 60 mm transaxial field of view (FOV) and a 26 mm axial FOV. Performance tests (e.g. spatial resolution, energy resolution, and sensitivity) and phantom and animal imaging studies were performed to evaluate the imaging performance of the PET imaging system. The performance tests and animal imaging results demonstrate the feasibility of an animal PET system based on SiPM detectors and indicate that SiPM detectors can be promising photodetectors in animal PET instrumentation development.

  3. Combined PET/MRI

    DEFF Research Database (Denmark)

    Bailey, D L; Pichler, B J; Gückel, B

    2018-01-01

    The 6th annual meeting to address key issues in positron emission tomography (PET)/magnetic resonance imaging (MRI) was held again in Tübingen, Germany, from March 27 to 29, 2017. Over three days of invited plenary lectures, round table discussions and dialogue board deliberations, participants c...... of response to pharmacological interventions and therapies. As such, PET/MRI is a key to advancing medicine and patient care.......The 6th annual meeting to address key issues in positron emission tomography (PET)/magnetic resonance imaging (MRI) was held again in Tübingen, Germany, from March 27 to 29, 2017. Over three days of invited plenary lectures, round table discussions and dialogue board deliberations, participants...... critically assessed the current state of PET/MRI, both clinically and as a research tool, and attempted to chart future directions. The meeting addressed the use of PET/MRI and workflows in oncology, neurosciences, infection, inflammation and chronic pain syndromes, as well as deeper discussions about how...

  4. Adenosine A{sub 1} receptors in human sleep regulation studied by electroencephalography (EEG) and positron emission tomography (PET)[Dissertation 17227

    Energy Technology Data Exchange (ETDEWEB)

    Geissler, E

    2007-07-01

    Sleep is an essential physiological process. However, the functions of sleep and the endogenous mechanisms involved in sleep regulation are only partially understood. Convergent lines of evidence support the hypothesis that the build-up of sleep propensity during wakefulness and its decline during sleep are associated with alterations in brain adenosine levels and adenosine receptor concentrations. The non-selective A{sub 1} and A{sub 2A} adenosine receptor antagonist caffeine stimulates alertness and is known to attenuate changes in the waking and sleep electroencephalogram (EEG) typically observed after prolonged waking. Several findings point to an important function of the adenosine A{sub 1} receptor (A{sub 1}AR) in the modulation of vigilance states. The A{sub 1}AR is densely expressed in brain regions involved in sleep regulation, and pharmacological manipulations affecting the A{sub 1}AR were shown to influence sleep propensity and sleep depth. However, an involvement of the A{sub 2A} adenosine receptor (A{sub 2A}AR) is also assumed. The distinct functions of the A{sub 1} and A{sub 2A} receptor subtypes in sleep-wake regulation and in mediating the effects of caffeine have not been identified so far. The selective adenosine A{sub 1} receptor antagonist, 8-cyclopentyl-3-(3-{sup 18}Ffluoropropyl)- 1-propylxanthine ({sup 18}F-CPFPX), offers the opportunity to get further insights into adenosinergic mechanisms by in vivo imaging of the A{sub 1}AR subtype with positron emission tomography (PET). The aim of this thesis was to elucidate the role of adenosine A{sub 1} receptors in human sleep regulation, combining {sup 18}F-CPFPX PET brain imaging and EEG recordings, the gold standard in sleep research. It was hypothesized that sleep deprivation would induce adenosine accumulation and/or changes in A{sub 1}AR density. Thus, the question was addressed whether these effects of prolonged wakefulness can be visualized by altered {sup 18}F-CPFPX binding. Moreover, it was

  5. Late infectious endocarditis of surgical patch closure of atrial septal defects diagnosed by 18F-fluorodeoxyglucose gated cardiac computed tomography (18F-FDG-PET/CT): a case report.

    Science.gov (United States)

    Honnorat, Estelle; Seng, Piseth; Riberi, Alberto; Habib, Gilbert; Stein, Andreas

    2016-08-24

    In contrast to percutaneous atrial septal occluder device, surgical patch closure of atrial defects was known to be no infective endocarditis risk. We herein report the first case of late endocarditis of surgical patch closure of atrial septal defects occurred at 47-year after surgery. On September 2014, a 56-year-old immunocompetent French Caucasian man was admitted into the Emergency Department for 3-week history of headache, acute decrease of psychomotor performance and fever at 40 °C. The diagnosis has been evoked during his admission for the management of a brain abscess and confirmed using 18F-fluorodeoxyglucose gated cardiac computed tomography (18F-FDG-PET/CT). Bacterial cultures of surgical deep samples of brain abscess were positive for Streptococcus intermedius and Aggregatibacter aphrophilus as identified by the matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry and confirmed with 16S rRNA gene sequencing. The patient was treated by antibiotics for 8 weeks and surgical patch closure removal. In summary, late endocarditis on surgical patch and on percutaneous atrial septal occluder device of atrial septal defects is rare. Cardiac imaging by the 18F-fluorodeoxyglucose gated cardiac computed tomography (18F-FDG-PET/CT) could improve the diagnosis and care endocarditis on surgical patch closure of atrial septal defects while transthoracic and transesophageal echocardiography remained difficult to interpret.

  6. Evaluation of Orthopedic Metal Artifact Reduction Application in Three-Dimensional Computed Tomography Reconstruction of Spinal Instrumentation: A Single Saudi Center Experience.

    Science.gov (United States)

    Ali, Amir Monir

    2018-01-01

    The aim of the study was to evaluate the commercially available orthopedic metal artifact reduction (OMAR) technique in postoperative three-dimensional computed tomography (3DCT) reconstruction studies after spinal instrumentation and to investigate its clinical application. One hundred and twenty (120) patients with spinal metallic implants were included in the study. All had 3DCT reconstruction examinations using the OMAR software after obtaining the informed consents and approval of the Institution Ethical Committee. The degree of the artifacts, the related muscular density, the clearness of intermuscular fat planes, and definition of the adjacent vertebrae were qualitatively evaluated. The diagnostic satisfaction and quality of the 3D reconstruction images were thoroughly assessed. The majority (96.7%) of 3DCT reconstruction images performed were considered satisfactory to excellent for diagnosis. Only 3.3% of the reconstructed images had rendered unacceptable diagnostic quality. OMAR can effectively reduce metallic artifacts in patients with spinal instrumentation with highly diagnostic 3DCT reconstruction images.

  7. Application of PET in breast cancer

    International Nuclear Information System (INIS)

    Noh, Dong Young

    2002-01-01

    Positron emission tomography (PET) is an imaging method that employs radionuclide and tomography techniques. Since 1995, we applied PET not only to the diagnosis of breast cancer but also to the detection of abnormalities in the augmented breast and to the detection of metastasis. Until 2001, we evaluated 242 breast cases by PET at PET center of Seoul National University Hospital. Our group has reported serially at the international journals. In the firtst report, PET showed high sensitivity for detecting breast cancer, both the primary and axillary node metastasis. A total of 27 patients underwent breast operations based on PET results at Seoul National University Hospital from 1995 to 1996. The diagnostic accuracy of PET were 97% for the primary tumor mass and 96% for axillary lymph node metastasis. In case of the breast augmented, PET also showed excellent diagnostic results for primary breast cancer and axillary lymph node metastasis where mammography and ultrasound could not diagnose properly. PET also had outstanding results in the detection of recurrent or metastatic breast cancer(sensitivity 94%, specificity 80%, accuracy 89%). In addition, our study gave some evidence that PET could be applied further to evaluate the growth rate of tumors by measuring SUV, and finally to prognosticated the disease. PET could also be applied to evaluate the response after chemotherapy to measure its metabolic rate and size. In conclsion, PET is a highly sensitive, accurate diagnostic tool for breast cancer of primary lesion in various conditions including metastasis

  8. Examination of brain function using PET and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Yasuhito; Momose, Toshinitsu; Watanabe, Toshiaki; Oku, Shinya; Nishikawa, Junichi [Tokyo Univ. (Japan). Faculty of Medicine

    1996-12-31

    The purpose of the presentation is to elucidate the unique role of PET (positron emission computed tomography) and SPECT (single photon emission computed tomography) in assessing physiological and biochemical functions of the brain.

  9. Interobserver agreement in fusion status assessment after instrumental desis of the lower lumbar spine using 64-slice multidetector computed tomography

    DEFF Research Database (Denmark)

    Laoutliev, Borislav; Havsteen, Inger; Bech, Birthe Højlund

    2012-01-01

    Persistent lower back pain after instrumental posterolateral desis may arise from incomplete fusion. We investigate the impact of experience on interobserver agreement in fusion estimation.......Persistent lower back pain after instrumental posterolateral desis may arise from incomplete fusion. We investigate the impact of experience on interobserver agreement in fusion estimation....

  10. Fluorine F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for restaging of non small cell lung cancer (NSCLC): analysis of management change and survival in 63 consecutive patients

    International Nuclear Information System (INIS)

    Hicks, R.J.; Binns, D.J.; Kalff, V.; Ware, R.E.; Hogg, A.; MacManus, M.P.; Ball, D.L.; Suter, M.E.; Matthews, J.

    2000-01-01

    Full text: Following treatment with curative intent for non small cell lung cancer (NSCLC), assessment of disease status using conventional techniques is often difficult. We evaluated management impact and prognostic value of FDG PET in 63 consecutive patients undergoing restaging of NSCLC between 11/96 and 12/98. All patients were >6 months from primary treatment with curative intent. Salvage therapy with curative intent was being contemplated in 18 patients. Conventional imaging was abnormal 61/63 patients, two others had recurrent symptoms only. Compared to conventional restaging, 33% of patients were down-staged, and 35% were upstaged by PET. PET led to more aggressive treatment than planned in 7 patients (11%), a change from planned curative to palliative treatment in 8 patients (13%) and 17 patients (27%) thought to have recurrent disease had no further investigation or treatment after negative PET studies. Cox proportional hazards analysis indicated that a positive PET scan had a hazard ratio of 2.95 (95% CI 1.038.50, p = 0.012) compared to negative PET. Extent of active disease on PET was also prognostically significant with each incremental extent category (no disease, local recurrence, limited locoregional, extensive locoregional and systemic) having an estimated 60% increase in the rate of death (95% Cl 24% to 107%, p<0.0001). Stage of disease at initial diagnosis, primary treatment used and disease extent on conventional restaging were not predictive of survival. Thus, PET provided a high impact on management for NSCLC patients with suspected recurrence and more accurate prognostic stratification than conventional staging. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  11. Evaluation of pulmonary nodules: comparison of a prototype dual crystal (LSO/NAI) dual head coincidence camera and full ring positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Joshi, U.; Raijmakers, P.G.H.M.; Lingen, A. van; Comans, E.F.I.; Pijpers, R.; Teule, G.J.J.; Hoekstra, O.S.

    2005-01-01

    Purpose: To determine the concordance of a prototype dual head coincidence camera (LSO-PS) and full ring PET (BGO-PET) using 18 F-fluorodeoxyglucose (FDG) in the evaluation of pulmonary nodules (PNs). Materials and methods: Patients referred for evaluation of ≤3 PNs (≤3 cm diameter) were prospectively studied on the same day with both BGO-PET and LSO-PS. Imaging was performed at 60 and 120 min after injection of 370 MBq FDG, respectively. Images were independently interpreted by four observers with each observer blinded to the other modality for the same patient. Lesions were scored in terms of relative intensity versus background. Non-attenuation corrected (nonAC) BGO-PET was used as the reference test. Results: Forty-seven patients with 54 PNs (mean diameter 1.7 cm, S.D. 0.7) were included. Twelve nodules were in the ≤1.0 cm - 27 in the 1.1-2.0 cm - and 15 in the 2.1-3.0 cm range. Interobserver agreement was similar for both FDG imaging modalities. Using a sensitive assessment strategy with LSO-PS (≥ faint intensity deemed positive), there was a 97% (38/39, 95%CI 87-100%) concordance with BGO-PET and one false positive case with LSO-PS. Conservative reading (moderate or intense intensity deemed positive) resulted in a 92% (36/39, 95%CI 80-97%) concordance with BGO-PET, without false positives. The only lesion missed by LSO-PS using both assessment strategies involved a nodule 1.5 cm diameter that demonstrated moderate increased FDG uptake on BGO-PET. Conclusion: Depending on the test positivity criteria, LSO-PS demonstrates a high concordance (92-97%) with nonAC BGO-PET for the characterization of pulmonary nodules

  12. Cranial neuronavigation with direct integration of 11C methionine positron emission tomography (PET) data - results of a pilot study in 32 surgical cases

    International Nuclear Information System (INIS)

    Braun, V.; Dempf, S.; Richter, H.P.; Weller, R.; Reske, S.-N.; Schanchenmayr, W.

    2002-01-01

    MRI detects small intracranial lesions, but has difficulties in differentiating between tumor, gliosis and edema. 11 C methionine-PET may help to overcome this problem. For its appropriate intra-operative use, it must be integrated into neuronavigation. We present the results of our pilot study with this method. 32 patients with 34 intracranial lesions detected by MRI underwent additional 11 C methionine-PET, because the pathophysiological behavior or the tumor delineation was unclear. All lesions were treated surgically. In 25 patients PET data could be integrated directly into cranial neuronavigation. 11 C methionine uptake was observed in 27/34 lesions, 26 of them were tumors: 14 malignant and 7 benign gliomas, 3 gliomas without further histological typing, one Ewing sarcoma and one non-Hodgkin lymphoma. Only one 11 C methionine positive lesion was non-tumorous: it was staged as post-irradiation necrosis in a patient operated on for a malignant glioma. 3/7 11 C-methionine negative lesions were classified as gliosis (n = 2) and M. Whipple (n = 1), but 4/7 were tumors: 2 astrocytomas WHO o II, 1 DNT and one astrocytoma WHO o III. The sensitivity of 11 C methionine-PET was 87 %, the specificity 75 %, the positive predictive value 96 % and the negative predictive value 43 %. In all tumorous cases with positive tracer uptake the borderline area of the tumor was better defined by C methionine-PET than by MRI. Interpretation: A positive 11 C methionine-PET is highly suspicious of a tumor, a negative one does not exclude it. 11 C methionine-PET seems to be more sensitive than MRI for differentiating between tumor and edema or gliosis. Simultaneous integration MRI and 11 C methionine-PET into cranial neuronavigation can facilitate cross total tumor removal in glioma surgery. (author)

  13. Advances in SPECT Instrumentation (Including Small Animal Scanners). Chapter 4

    International Nuclear Information System (INIS)

    Di Domenico, G.; Zavattini, G.

    2009-01-01

    Fundamental major efforts have been devoted to the development of positron emission tomography (PET) imaging modality over the last few decades. Recently, a novel surge of interest in single photon emission computed tomography (SPECT) technology has occurred, particularly after the introduction of the hybrid SPECT-CT imaging system. This has led to a flourishing of investigations in new types of detectors and collimators, and to more accurate refinement of reconstruction algorithms. Along with SPECT-CT, new, fast gamma cameras have been developed for dedicated cardiac imaging. The existing gap between PET and SPECT in sensitivity and spatial resolution is progressively decreasing, and this trend is particularly apparent in the field of small animal imaging where the most important advances have been reported in SPECT tomographs. An outline of the basic features of SPECT technology, and of recent developments in SPECT instrumentation for both clinical applications and basic biological research on animal models is described. (author)

  14. Gamma camera based Positron Emission Tomography: a study of the viability on quantification; Tomografia por emissao de positrons com sistemas PET/SPECT: um estudo da viabilidade de quantifizacao

    Energy Technology Data Exchange (ETDEWEB)

    Pozzo, Lorena

    2005-07-01

    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

  15. Root Canal Transportation and Centering Ability of Nickel-Titanium Rotary Instruments in Mandibular Premolars Assessed Using Cone-Beam Computed Tomography.

    Science.gov (United States)

    Mamede-Neto, Iussif; Borges, Alvaro Henrique; Guedes, Orlando Aguirre; de Oliveira, Durvalino; Pedro, Fábio Luis Miranda; Estrela, Carlos

    2017-01-01

    The aim of this study was to evaluate, using cone-beam computed tomography (CBCT), transportation and centralization of different nickel-titanium (NiTi) rotary instruments. One hundred and twenty eight mandibular premolars were selected and instrumented using the following brands of NiTi files: WaveOne, WaveOne Gold, Reciproc, ProTaper Next, ProTaper Gold, Mtwo, BioRaCe and RaCe. CBCT imaging was performed before and after root canal preparation to obtain measurements of mesial and distal dentin walls and calculations of root canal transportation and centralization. A normal distribution of data was confirmed by the Kolmogorov-Smirnov and Levene tests, and results were assessed using the Kruskal-Wallis test. Statistical significance was set at 5%. ProTaper Gold produced the lowest canal transportation values, and RaCe, the highest. ProTaper Gold files also showed the highest values for centering ability, whereas BioRaCe showed the lowest. No significant differences were found across the different instruments in terms of canal transportation and centering ability (P > 0.05). Based on the methodology employed, all instruments used for root canal preparation of mandibular premolars performed similarly with regard to canal transportation and centering ability.

  16. Avaliando a difusão de tecnologias médicas no sistema de saúde privado no Brasil: o caso da tomografia por emissão de pósitrons (PET Assessing the use of medical technology in the private health system in Brazil: the case of Positron Emission Tomography (PET

    Directory of Open Access Journals (Sweden)

    Ana Luiza d´Ávila Viana

    2010-11-01

    Full Text Available OBJETIVOS: analisar os determinantes da difusão da tomografia por emissão de pósitrons (PET em um conjunto selecionado de prestadores de serviços e operadoras de planos de saúde no Brasil. MÉTODOS: estudo de caso qualitativo, com coleta de dados realizada por meio de entrevistas em profundidade (N=9 com representantes de quatro prestadores de serviços de saúde privados e três operadoras de planos de saúde. RESULTADOS: as decisões para aquisição da tecnologia estudada são tomadas por dirigentes de hospitais e clínicas que adotam uma estratégia de diferenciação baseada em liderança tecnológica. Os fatores que influenciam essa decisão são: histórico de pioneirismo da instituição na incorporação de tecnologias; pressão do corpo clínico vinculado à instituição; prestígio do médico ou da área demandante; disponibilidade de recursos financeiros; acesso facilitado à tecnologia; concorrência entre os prestadores de serviços de saúde; evidências científicas; e rentabilidade do investimento. CONCLUSÕES: os atuais instrumentos de política usados para gerenciar a difusão de tecnologias médicas no sistema de saúde brasileiro exercem pouca influência nas decisões de grandes prestadores privados, cujas atividades não estão necessariamente relacionadas com as necessidades de saúde da população ou com as prioridades da política de saúde.OBJECTIVES: to analyze the determining factors underlying the extent to which positron emission tomography (PET is used in a selected medical services provider covered by private health insurance plans in Brazil. METHODS: a qualitative case study was undertaken with data collected by means of in-depth interviews (N=9 with representatives of four private health service providers and three health insurance plan operators. RESULTS: the decisions to acquire the technology under study are taken by managers of hospitals and clinics that adopt a strategy based on excellence in

  17. Kinetic modeling in PET imaging of hypoxia

    DEFF Research Database (Denmark)

    Li, Fan; Jørgensen, Jesper Tranekjær; Hansen, Anders E

    2014-01-01

    be used for non-invasive mapping of tissue oxygenation in vivo and several hypoxia specific PET tracers have been developed. Evaluation of PET data in the clinic is commonly based on visual assessment together with semiquantitative measurements e.g. standard uptake value (SUV). However, dynamic PET......Tumor hypoxia is associated with increased therapeutic resistance leading to poor treatment outcome. Therefore the ability to detect and quantify intratumoral oxygenation could play an important role in future individual personalized treatment strategies. Positron Emission Tomography (PET) can...... analysis for PET imaging of hypoxia....

  18. Preoperative PET/CT in early-stage breast cancer

    DEFF Research Database (Denmark)

    Bernsdorf, M; Berthelsen, A K; Timmermans-Wielenga, Vera

    2012-01-01

    The aim of this study was to assess the diagnostic and therapeutic impact of preoperative positron emission tomography and computed tomography (PET/CT) in the initial staging of patients with early-stage breast cancer.......The aim of this study was to assess the diagnostic and therapeutic impact of preoperative positron emission tomography and computed tomography (PET/CT) in the initial staging of patients with early-stage breast cancer....

  19. 'PET -Compton' system. Comparative evaluation with PET system using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Diaz Garcia, Angelina; Arista Romeu, Eduardo; Abreu Alfonso, Yamiel; Leyva Fabelo, Antonio; Pinnera Hernandez, Ibrahin; Bolannos Perez, Lourdes; Rubio Rodriguez, Juan A; Perez Morales, Jose M.; Arce Dubois, Pedro; Vela Morales, Oscar; Willmott Zappacosta, Carlos

    2011-01-01

    Positron Emission Tomography (PET) in small animals has actually achieved spatial resolution round about 1 mm and currently there are under study different approaches to improve this spatial resolution. One of them combines PET technology with Compton Cameras. This paper presents the idea of the so called 'PET-Compton' systems and includes comparative evaluation of spatial resolution and global efficiency in both PET and PET-Compton system by means of Monte Carlo simulations using Geant4 code. Simulation is done on a PET-Compton system consisting of LYSO-LuYAP scintillating detectors of particular small animal PET scanner named 'Clear-PET' and for Compton detectors based on CdZnTe semiconductor. A group of radionuclides that emits a positron (e + ) and γ quantum almost simultaneously and fulfills some selection criteria for their possible use in PET-Compton systems for medical and biological applications were studied under simulation conditions. (Author)

  20. Recommendations for the use of PET and PET-CT for radiotherapy planning in research projects.

    Science.gov (United States)

    Somer, E J; Pike, L C; Marsden, P K

    2012-08-01

    With the increasing use of positron emission tomography (PET) for disease staging, follow-up and therapy monitoring in a number of oncological indications there is growing interest in the use of PET and PET-CT for radiation treatment planning. In order to create a strong clinical evidence base for this, it is important to ensure that research data are clinically relevant and of a high quality. Therefore the National Cancer Research Institute PET Research Network make these recommendations to assist investigators in the development of radiotherapy clinical trials involving the use of PET and PET-CT. These recommendations provide an overview of the current literature in this rapidly evolving field, including standards for PET in clinical trials, disease staging, volume delineation, intensity modulated radiotherapy and PET-augmented planning techniques, and are targeted at a general audience. We conclude with specific recommendations for the use of PET in radiotherapy planning in research projects.

  1. Detection of Cancer with PET and PET/CT in Asymptomatic Volunteers

    International Nuclear Information System (INIS)

    Chung, Ji In; Choi, Joon Young; Lee, Kyung Han; Kim, Byung Tae; Choi, Yoon Ho; Cho, Han Byoul; Shim, Jae Yong

    2009-01-01

    We retrospectively investigated the diagnostic performance of 18 F-fluorodeoxyglucose positron emission tomography (PET) and PET/CT for cancer detection in asymptomatic health-check examinees. This study consisted of 5091 PET or PET/CT conducted as part of annual health examination at one hospital from March 1998 to February 2008. To find the incidence of cancers, medical records of the subjects were thoroughly reviewed for a follow-up period of one year. The patterns of formal readings of PET and PET/CT were analyzed to assess the sensitivity and specificity for cancer detection. The histopathology and stage of the cancers were evaluated in relation to the results of PET. Eighty-six cancers (1.7%) were diagnosed within one year after PET or PET/CT. When PET and PET/CT results were combined, the sensitivity was 48.8% and specificity was 81.1% for cancer detection. PET only had a sensitivity of 46.2% and a specificity of 81.4%, and PET/CT only had a sensitivity of 75.0% and a specificity of 78.5% respectively. There were no significant differences in cancer site, stage and histopathology between PET positive and PET negative cancers. In 19.3% of formal readings of PET and PET/CT, further evaluation to exclude malignancy or significant disease was recommended. Head and neck area and upper gastrointestinal tract were commonly recommended sites for further evaluation. PET and PET/CT showed moderate performance for detecting cancers in asymptomatic adults in this study. More experience and further investigation are needed to overcome limitations of PET and PET/CT for cancer screening

  2. The effect of a manual instrumentation technique on five types of premolar root canal geometry assessed by microcomputed tomography and three-dimensional reconstruction

    International Nuclear Information System (INIS)

    Li, Ke-Zeng; Gao, Yuan; Zhang, Ru; Hu, Tao; Guo, Bin

    2011-01-01

    Together with diagnosis and treatment planning, a good knowledge of the root canal system and its frequent variations is a necessity for successful root canal therapy. The selection of instrumentation techniques for variants in internal anatomy of teeth has significant effects on the shaping ability and cleaning effectiveness. The aim of this study was to reveal the differences made by including variations in the internal anatomy of premolars into the study protocol for investigation of a single instrumentation technique (hand ProTaper instruments) assessed by microcomputed tomography and three-dimensional reconstruction. Five single-root premolars, whose root canal systems were classified into one of five types, were scanned with micro-CT before and after preparation with a hand ProTaper instrument. Instrumentation characteristics were measured quantitatively in 3-D using a customized application framework based on MeVisLab. Numeric values were obtained for canal surface area, volume, volume changes, percentage of untouched surface, dentin wall thickness, and the thickness of dentin removed. Preparation errors were also evaluated using a color-coded reconstruction. Canal volumes and surface areas were increased after instrumentation. Prepared canals of all five types were straightened, with transportation toward the inner aspects of S-shaped or multiple curves. However, a ledge was formed at the apical third curve of the type II canal system and a wide range in the percentage of unchanged canal surfaces (27.4-83.0%) was recorded. The dentin walls were more than 0.3 mm thick except in a 1 mm zone from the apical surface and the hazardous area of the type II canal system after preparation with an F3 instrument. The 3-D color-coded images showed different morphological changes in the five types of root canal systems shaped with the same hand instrumentation technique. Premolars are among the most complex teeth for root canal treatment and instrumentation techniques

  3. The effect of a manual instrumentation technique on five types of premolar root canal geometry assessed by microcomputed tomography and three-dimensional reconstruction

    Directory of Open Access Journals (Sweden)

    Hu Tao

    2011-06-01

    Full Text Available Abstract Background Together with diagnosis and treatment planning, a good knowledge of the root canal system and its frequent variations is a necessity for successful root canal therapy. The selection of instrumentation techniques for variants in internal anatomy of teeth has significant effects on the shaping ability and cleaning effectiveness. The aim of this study was to reveal the differences made by including variations in the internal anatomy of premolars into the study protocol for investigation of a single instrumentation technique (hand ProTaper instruments assessed by microcomputed tomography and three-dimensional reconstruction. Methods Five single-root premolars, whose root canal systems were classified into one of five types, were scanned with micro-CT before and after preparation with a hand ProTaper instrument. Instrumentation characteristics were measured quantitatively in 3-D using a customized application framework based on MeVisLab. Numeric values were obtained for canal surface area, volume, volume changes, percentage of untouched surface, dentin wall thickness, and the thickness of dentin removed. Preparation errors were also evaluated using a color-coded reconstruction. Results Canal volumes and surface areas were increased after instrumentation. Prepared canals of all five types were straightened, with transportation toward the inner aspects of S-shaped or multiple curves. However, a ledge was formed at the apical third curve of the type II canal system and a wide range in the percentage of unchanged canal surfaces (27.4-83.0% was recorded. The dentin walls were more than 0.3 mm thick except in a 1 mm zone from the apical surface and the hazardous area of the type II canal system after preparation with an F3 instrument. Conclusions The 3-D color-coded images showed different morphological changes in the five types of root canal systems shaped with the same hand instrumentation technique. Premolars are among the most

  4. Additional value of PET-CT in the staging of lung cancer: comparison with CT alone, PET alone and visual correlation of PET and CT

    International Nuclear Information System (INIS)

    Wever, W. de; Marchal, G.; Bogaert, J.; Verschakelen, J.A.; Ceyssens, S.; Mortelmans, L.; Stroobants, S.

    2007-01-01

    Integrated positron emission tomography (PET) and computed tomography (CT) is a new imaging modality offering anatomic and metabolic information. The purpose was to evaluate retrospectively the accuracy of integrated PET-CT in the staging of a suggestive lung lesion, comparing this with the accuracy of CT alone, PET alone and visually correlated PET-CT. Fifty patients undergoing integrated PET-CT for staging of a suggestive lung lesion were studied. Their tumor, node, metastasis (TNM) statuses were determined with CT, PET, visually correlated PET-CT and integrated PET-CT. These TNM stages were compared with the surgical TNM status. Integrated PET-CT was the most accurate imaging technique in the assessment of the TNM status. Integrated PET-CT predicted correctly the T status, N status, M status and TNM status in, respectively, 86%, 80%, 98%, 70% versus 68%, 66%,88%, 46% with CT, 46%, 70%, 96%, 30% with PET and 72%, 68%, 96%, 54% with visually correlated PET-CT. T status and N status were overstaged, respectively, in 8% and 16% with integrated PET-CT, in 20% and 28% with CT, in 16% and 20% with PET, in 12% and 20% with visually correlated PET-CT and understaged in 6% and 4% with integrated PET-CT, versus 12% and 6% with CT, 38% and 10% with PET and 12% with visually correlated PET-CT. Integrated PET-CT improves the staging of lung cancer through a better anatomic localization and characterization of lesions and is superior to CT alone and PET alone. If this technique is not available, visual correlation of PET and CT can be a valuable alternative. (orig.)

  5. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

    Science.gov (United States)

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-01-01

    Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (protary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal. PMID:26092929

  6. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography.

    Science.gov (United States)

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-06-20

    Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal.

  7. 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...

  8. Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons

    Science.gov (United States)

    Sato, K.; Kobayashi, Y.

    2015-05-01

    Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed.

  9. Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons

    International Nuclear Information System (INIS)

    Sato, K.; Kobayashi, Y.

    2015-01-01

    Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed

  10. PET imaging of inflammation

    International Nuclear Information System (INIS)

    Buscombe, J. R.

    2014-01-01

    Inflammatory diseases are common place and often chronic. Most inflammatory cells have increased uptake of glucose which is enhanced in the presence of local cytokines. Therefore, imaging glucose metabolism by the means of 18F-fluoro-deoxy-glucose (FDG) positron emission tomography (PET) holds significant promise in imaging focal inflammation. Most of the work published involved small series of patients with either vasculitis, sarcoid or rheumatoid arthritis. It would appear that FDG PET is a simple and effective technique to identify inflammatory tissue in these conditions. There is even some work to suggest that by comparing baseline and early post therapy scans clinical outcome can be predicted. This would appear to be true with vasculitis as well as retroperitoneal fibrosis. The number of patients in each study is small but the evidence is compelling enough to recommend FDG PET imaging in the routine care of these patients.

  11. Pet in Clinical oncology

    International Nuclear Information System (INIS)

    Hunsche, A.; Grossman, G.; Santana, M.; Santana, C.; Halkar, R.; Garcia, E.

    2003-01-01

    The utility of the PET (positron emission tomography in clinical oncology has been recognized for more than two decades, locating it as a sensible technique for the diagnosis and the prognosis stratification of the oncology patients. The sensitivity and specificity of the PET in comparation to other image studies have demonstrated to be greater. For some years, there was a restriction of PET because of the high cost of the equipment and the cyclotrons. Nevertheless, the relation of cost/benefits is considered as a priority as this technique offers important clinical information. In this article the results observed when using it in diverse types of cancer, as well as the effectiveness shown in the pre-operating evaluation, the evaluation of residual disease, diagnosis of recurrences, pursuit and prognosis stratification of the patients with cancer. (The author)

  12. FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0

    DEFF Research Database (Denmark)

    Boellaard, Ronald; O'Doherty, Mike J; Weber, Wolfgang A

    2010-01-01

    The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about[18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed tomogr...

  13. FDG PET and PET/CT : EANM procedure guidelines for tumour PET imaging: version 1.0

    NARCIS (Netherlands)

    Boellaard, Ronald; O'Doherty, Mike J.; Weber, Wolfgang A.; Mottaghy, Felix M.; Lonsdale, Markus N.; Stroobants, Sigrid G.; Oyen, Wim J. G.; Kotzerke, Joerg; Hoekstra, Otto S.; Pruim, Jan; Marsden, Paul K.; Tatsch, Klaus; Hoekstra, Corneline J.; Visser, Eric P.; Arends, Bertjan; Verzijlbergen, Fred J.; Zijlstra, Josee M.; Comans, Emile F. I.; Lammertsma, Adriaan A.; Paans, Anne M.; Willemsen, Antoon T.; Beyer, Thomas; Bockisch, Andreas; Schaefer-Prokop, Cornelia; Delbeke, Dominique; Baum, Richard P.; Chiti, Arturo; Krause, Bernd J.

    The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about [18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed

  14. FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0

    NARCIS (Netherlands)

    Boellaard, Ronald; O'Doherty, Mike J.; Weber, Wolfgang A.; Mottaghy, Felix M.; Lonsdale, Markus N.; Stroobants, Sigrid G.; Oyen, Wim J. G.; Kotzerke, Joerg; Hoekstra, Otto S.; Pruim, Jan; Marsden, Paul K.; Tatsch, Klaus; Hoekstra, Corneline J.; Visser, Eric P.; Arends, Bertjan; Verzijlbergen, Fred J.; Zijlstra, Josee M.; Comans, Emile F. I.; Lammertsma, Adriaan A.; Paans, Anne M.; Willemsen, Antoon T.; Beyer, Thomas; Bockisch, Andreas; Schaefer-Prokop, Cornelia; Delbeke, Dominique; Baum, Richard P.; Chiti, Arturo; Krause, Bernd J.

    2010-01-01

    The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about[18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed

  15. FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0

    NARCIS (Netherlands)

    Boellaard, R.; O'Doherty, M.J.; Weber, W.A.; Mottaghy, F.M.; Lonsdale, M.N.; Stroobants, S.G.; Oyen, W.J.G.; Kotzerke, J.; Hoekstra, O.S.; Pruim, J.; Marsden, P.K.; Tatsch, K.; Hoekstra, C.J.; Visser, E.P.; Arends, B.; Verzijlbergen, F.J.; Zijlstra, J.M.; Comans, E.F.I.; Lammertsma, A.A.; Paans, A.M.; Willemsen, A.T.; Beyer, T.; Bockisch, A.; Schaefer-Prokop, C.; Delbeke, D.; Baum, R.P.; Chiti, A.; Krause, B.J.

    2010-01-01

    The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about [18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed

  16. Instruments for radiation measurement in life sciences (5), ''Development of imaging technology in life sciences'' III. Development of small animal PET scanners

    International Nuclear Information System (INIS)

    Yamaya, Taiga; Murayama, Hideo

    2006-01-01

    This paper summarizes the requisites for small animal PET scanners, present state of their market and of their development in National Institute of Radiological Sciences (NIRS). Relative to the apparatus clinically used, the requisites involve the high spatial resolution of 0.8-1.5 mm and high sensitivity of the equipment itself due to low dose of the tracer to be given to animals. At present, more than 20 institutions like universities, research facilities and companies are developing the PET equipment for small animals and about 10 machines are in the market. However, their resolution and sensitivity are not fully satisfactory and for their improvement, investigators are paying attention to the gamma ray measurement by depth-of-interaction (DOI) method. NIRS has been also developing the machine jPET-D4 and has proposed to manufacture jPET-RD having 4-layer DOI detectors with the absolute central sensitivity as high as 14.7%. jPET-RD is to have the spatial resolution as high as <1mm (central view) and -1.4 mm (periphery). (T.I.)

  17. 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

  18. Evaluation of the PET component of simultaneous [18F]choline PET/MRI in prostate cancer: comparison with [18F]choline PET/CT

    International Nuclear Information System (INIS)

    Wetter, Axel; Lipponer, Christine; Nensa, Felix; Altenbernd, Jens-Christian; Schlosser, Thomas; Lauenstein, Thomas; Heusch, Philipp; Ruebben, Herbert; Bockisch, Andreas; Poeppel, Thorsten; Nagarajah, James

    2014-01-01

    The aim of this study was to evaluate the positron emission tomography (PET) component of [ 18 F]choline PET/MRI and compare it with the PET component of [ 18 F]choline PET/CT in patients with histologically proven prostate cancer and suspected recurrent prostate cancer. Thirty-six patients were examined with simultaneous [ 18 F]choline PET/MRI following combined [ 18 F]choline PET/CT. Fifty-eight PET-positive lesions in PET/CT and PET/MRI were evaluated by measuring the maximum and mean standardized uptake values (SUV max and SUV mean ) using volume of interest (VOI) analysis. A scoring system was applied to determine the quality of the PET images of both PET/CT and PET/MRI. Agreement between PET/CT and PET/MRI regarding SUV max and SUV mean was tested using Pearson's product-moment correlation and Bland-Altman analysis. All PET-positive lesions that were visible on PET/CT were also detectable on PET/MRI. The quality of the PET images was comparable in both groups. Median SUV max and SUV mean of all lesions were significantly lower in PET/MRI than in PET/CT (5.2 vs 6.1, p max of PET/CT and PET/MRI (R = 0.86, p mean of PET/CT and PET/MRI (R = 0.81, p max of PET/CT vs PET/MRI and -1.12 to +2.23 between SUV mean of PET/CT vs PET/MRI. PET image quality of PET/MRI was comparable to that of PET/CT. A highly significant correlation between SUV max and SUV mean was found. Both SUV max and SUV mean were significantly lower in [ 18 F]choline PET/MRI than in [ 18 F]choline PET/CT. Differences of SUV max and SUV mean might be caused by different techniques of attenuation correction. Furthermore, differences in biodistribution and biokinetics of [ 18 F]choline between the subsequent examinations and in the respective organ systems have to be taken into account. (orig.)

  19. PET in malformations of cortical development; La tomographie d'emission de positons (TEP) dans les malformations corticales de developpement

    Energy Technology Data Exchange (ETDEWEB)

    Bouilleret, V.; O' Brien, T.J. [Department of medicine, the Royal Melbourne Hospital, Royal Parade, Parkville, 3005 Victoria (Australia); Bouilleret, V. [Unite de neurophysiologie clinique et d' epileptologie, AP-HP, CHU Bicetre, 94275 Paris (France); Bouilleret, V.; Chiron, C. [Service hospitalier Frederic-Joliot, DRM, CEA, 4, place du General-Leclerc, 91401 Orsay cedex (France); Chiron, C. [Inserm U663, AP-HP, hopital Necker, 75015 Paris (France); University Paris-Descartes, 11, rue Pierre-et-Marie-Curie, 75005 Paris (France)

    2009-01-15

    Within the group of malformations of cortical development, focal cortical dysplasia (FCD) are an increasingly recognized cause of intractable epilepsy that can be cured by surgery. The success of cortical resection for intractable epilepsy is highly dependent on the accurate pre-surgical delineation of the regions responsible for generating seizures. [{sup 18}F]-FDG PET, which images cerebral metabolism studying brain glucose uptake, is the most established functional imaging modality in the evaluation of patients with epilepsy. The aim of this article is to review [{sup 18}F]-FDG PET usefulness as a pre-surgical tool in the evaluation of medically refractory partial epilepsy. It has an established place in assisting in the localisation and definition of FCD in patients with no lesion, or only a subtle abnormality, on MRI. The role of FDG-PET in defining the extent of the surgical resection is still uncertain and needs to be the focus of future research. (authors)

  20. 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)

  1. PET/MR Imaging in Vascular Disease

    DEFF Research Database (Denmark)

    Ripa, Rasmus Sejersten; Pedersen, Sune Folke; Kjær, Andreas

    2016-01-01

    For imaging of atherosclerotic disease, lumenography using computed tomography, ultrasonography, or invasive angiography is still the backbone of evaluation. However, these methods are less effective to predict the likelihood of future thromboembolic events caused by vulnerability of plaques. PET...... through data and arguments that support increased use of PET/MR imaging in atherosclerotic imaging....

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

    International Nuclear Information System (INIS)

    Basu, Sandip

    2010-01-01

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

  3. Competitive advantage of PET/MRI

    Energy Technology Data Exchange (ETDEWEB)

    Jadvar, Hossein, E-mail: jadvar@usc.edu; Colletti, Patrick M.

    2014-01-15

    Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved.

  4. Competitive advantage of PET/MRI.

    Science.gov (United States)

    Jadvar, Hossein; Colletti, Patrick M

    2014-01-01

    Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Competitive advantage of PET/MRI

    International Nuclear Information System (INIS)

    Jadvar, Hossein; Colletti, Patrick M.

    2014-01-01

    Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved

  6. Comparison of dosimetry between PET/CT and PET alone using 11C-ITMM

    International Nuclear Information System (INIS)

    Ito, Kimiteru; Sakata, Muneyuki; Wagarsuma, Kei; Toyohara, Jun; Ishibashi, Kenji; Ishii, Kenji; Ishiwata, Kiichi; Oda, Keiichi

    2016-01-01

    We used a new tracer, N-[4-[6-(isopropylamino) pyrimidin-4-yl]-1,3-thiazol-2-yl]-4- 11 C-methoxy-N-methylbenzamide ( 11 C-ITMM), to compare radiation doses from positron emission tomography (PET)/computed tomography (CT) with previously published doses from PET alone. Twelve healthy volunteers [six males (mean age ± SD, 27.7 ± 6.7 years) and six females (31.8 ± 14.5 years)] in 12 examinations were recruited. Dose estimations from PET/CT were compared with those from PET alone. Regions of interest (ROIs) in PET/CT were delineated on the basis of low-dose CT (LD-CT) images acquired during PET/CT. Internal and external radiation doses were estimated using OLINDA/EXM 1.0 and CT-Expo software. The effective dose (ED) for 11 C-ITMM calculated from PET/CT was estimated to be 4.7 ± 0.5 μSv/MBq for the male subjects and 4.1 ± 0.7 μSv/MBq for the female subjects. The mean ED for 11 C-ITMM calculated from PET alone in a previous report was estimated to be 4.6 ± 0.3 μSv/MBq (males, n = 3). The ED values for 11 C-ITMM calculated from PET/CT in the male subjects were almost identical to those from PET alone. The absorbed doses (ADs) of the gallbladder, stomach, red bone marrow, and spleen calculated from PET/CT were significantly different from those calculated from PET alone. The EDs of 11 C-ITMM calculated from PET/CT were almost identical to those calculated from PET alone. The ADs in several organs calculated from PET/CT differed from those from PET alone. LD-CT images acquired during PET/CT may facilitate organ identification.

  7. Oral cancer diagnosed using PET/CT: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Hee; Yang, Byoung Eun; Cho, Young Min [Hallym Univ. College of Medicine, Anyang (Korea, Republic of); Kim, Seong Gon [Sam Anyang General Hospital, Anyang (Korea, Republic of)

    2006-06-15

    PET/CT is a new imaging technology that combines high-quality Position Emission Tomography (PET) and Computed Tomography (CT). This imaging provides simultaneous anatomical and metabolic information. Therefore PET/CT is useful diagnostic modality for early detection og malignant tumor, accurate at aging, decision on therapeutic plan, monitoring response to therapy and rapid detection of recurrence. We report oral and maxillofacial cancers diagnosed by using PET/CT and the usefulness of PET/CT in the evaluation of postoperative recurrence.

  8. Colorectal cancer staging: comparison of whole-body PET/CT and PET/MR.

    Science.gov (United States)

    Catalano, Onofrio A; Coutinho, Artur M; Sahani, Dushyant V; Vangel, Mark G; Gee, Michael S; Hahn, Peter F; Witzel, Thomas; Soricelli, Andrea; Salvatore, Marco; Catana, Ciprian; Mahmood, Umar; Rosen, Bruce R; Gervais, Debra

    2017-04-01

    Correct staging is imperative for colorectal cancer (CRC) since it influences both prognosis and management. Several imaging methods are used for this purpose, with variable performance. Positron emission tomography-magnetic resonance (PET/MR) is an innovative imaging technique recently employed for clinical application. The present study was undertaken to compare the staging accuracy of whole-body positron emission tomography-computed tomography (PET/CT) with whole-body PET/MR in patients with both newly diagnosed and treated colorectal cancer. Twenty-six patients, who underwent same day whole-body (WB) PET/CT and WB-PET/MR, were evaluated. PET/CT and PET/MR studies were interpreted by consensus by a radiologist and a nuclear medicine physician. Correlations with prior imaging and follow-up studies were used as the reference standard. Correct staging was compared between methods using McNemar's Chi square test. The two methods were in agreement and correct for 18/26 (69%) patients, and in agreement and incorrect for one patient (3.8%). PET/MR and PET/CT stages for the remaining 7/26 patients (27%) were discordant, with PET/MR staging being correct in all seven cases. PET/MR significantly outperformed PET/CT overall for accurate staging (P = 0.02). PET/MR outperformed PET/CT in CRC staging. PET/MR might allow accurate local and distant staging of CRC patients during both at the time of diagnosis and during follow-up.

  9. Preclinical, fluorescence and diffuse optical tomography: non-contact instrumentation, modeling and time-resolved 3D reconstruction

    International Nuclear Information System (INIS)

    Nouizi, F.

    2011-09-01

    Time-Resolved Diffuse Optical Tomography (TR-DOT) is a new non-invasive imaging technique increasingly used in the clinical and preclinical fields. It yields optical absorption and scattering maps of the explored organs, and related physiological parameters. Time-Resolved Fluorescence Diffuse Optical Tomography (TR-FDOT) is based on the detection of fluorescence photons. It provides spatio-temporal maps of fluorescent probe concentrations and life times, and allows access to metabolic and molecular imaging which is important for diagnosis and therapeutic monitoring, particularly in oncology. The main goal of this thesis was to reconstruct 3D TR-DOT/TR-FDOT images of small animals using time-resolved optical technology. Data were acquired using optical fibers fixed around the animal without contact with its surface. The work was achieved in four steps: 1)- Setting up an imaging device to record the 3D coordinates of an animal's surface; 2)- Modeling the no-contact approach to solve the forward problem; 3)- Processing of the measured signals taking into account the impulse response of the device; 4)- Implementation of a new image reconstruction method based on a selection of carefully chosen points. As a result, good-quality 3D optical images were obtained owing to reduced cross-talk between absorption and scattering. Moreover, the computation time was cut down, compared to full-time methods using whole temporal profiles. (author)

  10. Comparative Oncology: Evaluation of 2-Deoxy-2-[18F]fluoro-D-glucose (FDG Positron Emission Tomography/Computed Tomography (PET/CT for the Staging of Dogs with Malignant Tumors.

    Directory of Open Access Journals (Sweden)

    Stefanie M F Seiler

    Full Text Available 2-Deoxy-2-[18F]fluoro-D-glucose PET/CT is a well-established imaging method for staging, restaging and therapy-control in human medicine. In veterinary medicine, this imaging method could prove to be an attractive and innovative alternative to conventional imaging in order to improve staging and restaging. The aim of this study was both to evaluate the effectiveness of this image-guided method in canine patients with spontaneously occurring cancer as well as to illustrate the dog as a well-suited animal model for comparative oncology.Ten dogs with various malignant tumors were included in the study and underwent a whole body FDG PET/CT. One patient has a second PET-CT 5 months after the first study. Patients were diagnosed with histiocytic sarcoma (n = 1, malignant lymphoma (n = 2, mammary carcinoma (n = 4, sertoli cell tumor (n = 1, gastrointestinal stromal tumor (GIST (n = 1 and lung tumor (n = 1. PET/CT data were analyzed with the help of a 5-point scale in consideration of the patients' medical histories.In seven of the ten dogs, the treatment protocol and prognosis were significantly changed due to the results of FDG PET/CT. In the patients with lymphoma (n = 2 tumor extent could be defined on PET/CT because of increased FDG uptake in multiple lymph nodes. This led to the recommendation for a therapeutic polychemotherapy as a treatment. In one of the dogs with mammary carcinoma (n = 4 and in the patient with the lung tumor (n = 1, surgery was cancelled due to the discovery of multiple metastasis. Consequently no treatment was recommended.FDG PET/CT offers additional information in canine patients with malignant disease with a potential improvement of staging and restaging. The encouraging data of this clinical study highlights the possibility to further improve innovative diagnostic and staging methods with regard to comparative oncology. In the future, performing PET/CT not only for staging but also in therapy control could offer a

  11. Positron emission tomography (PET) and magnetic resonance imaging (MRI) for assessing tumour resectability in advanced epithelial ovarian, fallopian tube and/or primary peritoneal cancer

    NARCIS (Netherlands)

    Hoogendam, Jacob P.; Roze, Joline F.; van de Wetering, Fleur T.; Spijker, René; Verleye, Leen; Vlayen, Joan; Veldhuis, Wouter B.; Scholten, Rob J P M; Zweemer, RP

    2017-01-01

    This is a protocol for a Cochrane Review (Diagnostic test accuracy). The objectives are as follows: To assess the diagnostic test accuracy of PET(-CT), conventional and diffusion-weighted MRI as an replacement or an add-on to abdominal CT, for predicting tumour resectability at primary debulking

  12. Clinical usefulness of PET in the management of oral cancer. Comparison between FDG-PET and MET-PET

    International Nuclear Information System (INIS)

    Kitagawa, Yoshimasa; Saitoh, Masaaki; Nakamura, Mikiko

    2007-01-01

    Inductive chemoradiotherapy has played an important role in preserving organs and functions in patients with oral squamous cell carcinoma (SCC). To determine whether a reduced form of surgery should be performed after chemoradiotherapy, accurate evaluation of residual tumor cells is essential. We investigated the clinical value of positron emission tomography with 18 F labeled fluorodeoxyglucose (FDG-PET) in the management of oral SCCs. Forty-five patients underwent two FDG-PET studies, one prior to and one at 6 weeks after the chemoradiotherapy. Pretreatment FDG-PET was useful in predicting the response to treatment. Posttreatment FDG-PET could evaluate residual viable cells and prognosis. Organ preservation may be feasible based on PET evaluation. Hence FDG-PET is a valuable tool in the treatment of oral cancer. 11 C-Methionine (MET) is another promising tracer for PET that can be used to assess metabolic demand for amino acids in cancer cells. A MET-PET and FDG-PET study was performed during the same period to investigate diagnostic accuracy in 40 oral malignancies. Sensitivity and positive predictive value of MET-PET were 95% and 100%, respectively, and were comparable with those of FDG-PET. Further study is required to determine the diagnostic significance of MET-PET in evaluating response to chemoradiotherapy. (author)

  13. Correlation of hypoxic cell fraction with glucose metabolic rate in gliomas with 18F-Fluoromisonidazole (FMISO) and 18F- Fluorodeoxyglucose (FDG) positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Tauro, A.J.; Scott, A.M.; Hannah, A.; Pathmaraj, K.; Tochon-Danguy, H.; Sachinidis, J.I.; Chan, J.D.; Berlangieri, S.U.; Egan, G.F.; Fabinyi, G.; McKay, W.J.; Cher, L.M.; Austin and Repatriation Medical Centre, Heidelberg, VIC

    1998-01-01

    Full text: FDG-PET studies of brain tumours to measure tumour activity are well established, with regions of higher grade tumour utilising more glucose compared to lower grade tumour tissue and normal tissue. FDG uptake in tumour cells may reflect anaerobic glycolysis, but this has not been proven in- vivo. FMISO is a novel positron-emitting compound that has been shown to selectively identify hypoxic but viable tissue, which may contribute to chemoradiotherapy resistance in tumour cells. Studies correlating measurements of regional hypoxia and glucose activity within brain tumours prior to therapy may help gain further insight into the relationship between hypoxic tumour tissue and resistance to chemoradiotherapy. Three patients with newly diagnosed primary brain tumours have been prospectively studied with FMISO-PET, FDG-PET and MRI, prior to surgery. Each patient presented with a suspected primary brain glioma on MRI, which were all confirmed to be high grade glioma on subsequent histology at surgery FMISO-PET, FDG-PET and MRI images of all patients were co-registered to precisely identify the areas of metabolic activity within tumour and surrounding cortical tissue. All gliomas demonstrated areas of FMISO uptake, which corresponded to areas of maximal FDG uptake, indicating a correlation between hypoxic areas within tumour with areas of increased glucose metabolic activity. This supports the hypothesis that hypoxic areas within tumour tissue may be associated with increased FDG uptake, although whether hypoxia itself increases FDG uptake remains controversial. These correlative studies characterising areas of hypoxia and glucose activity should hopefully assist in future therapeutic manipulations to improve the outcome from treatment of primary brain tumours

  14. Recurrent renal cell carcinoma: clinical and prognostic value of FDG PET/CT

    International Nuclear Information System (INIS)

    Alongi, Pierpaolo; Picchio, Maria; Gianolli, Luigi; Zattoni, Fabio; Spallino, Marianna; Saladini, Giorgio; Evangelista, Laura

    2016-01-01

    The purpose of our study was 1) to evaluate the diagnostic performance of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT), 2) to assess the impact of FDG PET/CT on treatment decision-making, and 3) to estimate the prognostic value of FDG PET/CT in the restaging process among patients with renal cell carcinoma (RCC). From the FDG PET/CT databases of San Raffaele Hospital in Milan, Italy, and the Veneto Institute of Oncology in Padua, Italy, we selected 104 patients with a certain diagnosis of RCC after surgery, and for whom at least 24 months of post-surgical FDG PET/CT, clinical, and instrumental follow-up data was available. The sensitivity and specificity of FDG PET/CT were assessed by histology and/or other imaging as standard of reference. Progression-free survival (PFS) and overall survival (OS) were computed using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards models were used to identify predictors of outcome. FDG PET/CT resulted in a positive diagnosis in 58 patients and a negative diagnosis in 46 patients. Sensitivity and specificity were 74 % and 80 %, respectively. FDG PET/CT findings influenced therapeutic management in 45/104 cases (43 %). After a median follow-up period of 37 months (± standard deviation 12.9), 51 (49 %) patients had recurrence of disease, and 26 (25 %) had died. In analysis of OS, positive versus negative FDG PET/CT was associated with worse cumulative survival rates over a 5-year period (19 % vs. 69 %, respectively; p <0.05). Similarly, a positive FDG PET/CT correlated with a lower 3-year PFS rate. In addition, univariate and multivariate analysis revealed that a positive scan, alone or in combination with disease stage III-IV or nuclear grading 3-4, was associated with high risk of progression (multivariate analysis = hazard ratios [HRs] of 4.01, 3.7, and 2.8, respectively; all p < 0.05). FDG PET/CT is a valuable tool both in treatment decision-making and for

  15. Recurrent renal cell carcinoma: clinical and prognostic value of FDG PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Alongi, Pierpaolo; Picchio, Maria; Gianolli, Luigi [IRCCS San Raffaele Scientific Institute, Nuclear Medicine Department, Milan (Italy); Zattoni, Fabio [University of Padua, Department of Oncological and Surgical Sciences, Urology Clinic, Padua (Italy); Spallino, Marianna [University of Milano-Bicocca, Milan (Italy); Saladini, Giorgio; Evangelista, Laura [Veneto Institute of Oncology IOV - IRCCS, Padua, Italy, Radiotherapy and Nuclear Medicine Unit, Padua (Italy)

    2016-03-15

    The purpose of our study was 1) to evaluate the diagnostic performance of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT), 2) to assess the impact of FDG PET/CT on treatment decision-making, and 3) to estimate the prognostic value of FDG PET/CT in the restaging process among patients with renal cell carcinoma (RCC). From the FDG PET/CT databases of San Raffaele Hospital in Milan, Italy, and the Veneto Institute of Oncology in Padua, Italy, we selected 104 patients with a certain diagnosis of RCC after surgery, and for whom at least 24 months of post-surgical FDG PET/CT, clinical, and instrumental follow-up data was available. The sensitivity and specificity of FDG PET/CT were assessed by histology and/or other imaging as standard of reference. Progression-free survival (PFS) and overall survival (OS) were computed using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards models were used to identify predictors of outcome. FDG PET/CT resulted in a positive diagnosis in 58 patients and a negative diagnosis in 46 patients. Sensitivity and specificity were 74 % and 80 %, respectively. FDG PET/CT findings influenced therapeutic management in 45/104 cases (43 %). After a median follow-up period of 37 months (± standard deviation 12.9), 51 (49 %) patients had recurrence of disease, and 26 (25 %) had died. In analysis of OS, positive versus negative FDG PET/CT was associated with worse cumulative survival rates over a 5-year period (19 % vs. 69 %, respectively; p <0.05). Similarly, a positive FDG PET/CT correlated with a lower 3-year PFS rate. In addition, univariate and multivariate analysis revealed that a positive scan, alone or in combination with disease stage III-IV or nuclear grading 3-4, was associated with high risk of progression (multivariate analysis = hazard ratios [HRs] of 4.01, 3.7, and 2.8, respectively; all p < 0.05). FDG PET/CT is a valuable tool both in treatment decision-making and for

  16. Comparison of CE-FDG-PET/CT with CE-FDG-PET/MR in the evaluation of osseous metastases in breast cancer patients

    OpenAIRE

    Catalano, O A; Nicolai, E; Rosen, B R; Luongo, A; Catalano, M; Iannace, C; Guimaraes, A; Vangel, M G; Mahmood, U; Soricelli, A; Salvatore, M

    2015-01-01

    Background: Despite improvements in treatments, metastatic breast cancer remains difficult to cure. Bones constitute the most common site of first-time recurrence, occurring in 40?75% of cases. Therefore, evaluation for possible osseous metastases is crucial. Technetium 99 (99Tc) bone scintigraphy and fluorodexossyglucose (FDG) positron emission tomography (PET)-computed tomography (PET-CT) are the most commonly used techniques to assess osseous metastasis. PET magnetic resonance (PET-MR) ima...

  17. Using positron emission tomography (PET) response criteria in solid tumours (PERCIST) 1.0 for evaluation of 2'-deoxy-2'-[18F] fluoro-D-glucose-PET/CT scans to predict survival early during treatment of locally advanced non-small cell lung cancer (NSCLC).

    Science.gov (United States)

    Fledelius, Joan; Khalil, Azza Ahmed; Hjorthaug, Karin; Frøkiaer, Jørgen

    2016-04-01

    The demand for early-response evaluation with 2'-deoxy-2'-[18F] fluoro-D-glucose (F-18-FDG) positron emission tomography combined with whole body CT (PET/CT) is rapidly growing. This study was initiated to evaluate the applicability of the PET response criteria in solid tumours (PERCIST 1.0) for response evaluation. We performed a retrospective study of 21 patients with locally advanced non-small cell lung cancer (NSCLC), who had undergone both a baseline and a follow-up F-18-FDG-PET/CT scan during their treatments. The scans were performed at our institution in the period September 2009 and March 2011 and were analysed visually and according to PERCIST 1.0 by one board-certified nuclear medicine physician. The response was compared with overall survival (OS) and progression-free survival (PFS). The variation in key parameters affecting the F-18-FDG uptake was assessed. A kappa of 0.94 corresponding to an almost perfect agreement was found for the comparison of the visual evaluation with PERCIST. Patients with partial metabolic response and stable metabolic disease (as evaluated by PERCIST 1.0) had statistically significant longer median time to progression: 8.4 months (confidence interval (CI) 5.1-11.8 months) as compared with 2.7 months (CI 0-5.6 months) in patients classified with progression. The variation in uptake time between baseline and follow-up scans was more than the recommended 15 min in 48% of patients. PERCIST 1.0 is readily implementable and highly comparable with visual evaluation of response using early F-18-FDG-PET/CT scanning for locally advanced NSCLC patients. In spite of variations in parameters affecting F-18-FDG uptake, evaluation of F-18-FDG-PET/CT during treatment with PERCIST 1.0 is shown to separate non-responders from responders, each with statistically significant differences in both OS and PFS. © 2015 The Royal Australian and New Zealand College of Radiologists.

  18. 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...

  19. Fluorine-18-fluorodeoxyglucose positron emission tomography (PET) brain imaging patterns in patients with suspected X-linked dystonia parkinsonism (study in progress)

    International Nuclear Information System (INIS)

    Santiago, J.F.Y.; Fugoso, L.; Evidente, V.G.H.

    2004-01-01

    Objective: X-linked dystonia-parkinsonism (XDP or Lubag) is an adult-onset dystonia syndrome that afflicts mostly Filipino men from the island of Panay, Philippines.It starts focally and becomes generalized or multifocal after the first five years. Parkinsonism is commonly encountered as the initial symptom before the onset of dystonia. Patients may manifest a wide spectrum of movement disorders, including myoclonus, chorea, akathisia, ballism and myorhythmia. Diagnosis is based on the clinical presentation, and the establishment of an x-linked recessive pattern of inheritance and maternal roots from the Panay Islands. Neuroimaging in advanced cases have demonstrated caudate and putaminal atrophy. Previous studies using PET have shown selective reduction in normalized striatal glucose metabolism. The purpose of this study is to describe the FDG distribution using PET imaging in Filipino patients with suspected or confirmed Lubag in various stages of their disease in order to determine if FDG-PET can be used in the initial diagnosis and staging of the disease. Methods and results: All patients presenting to the Movement Disorders Center of St. Lukes Medical Center with dystonia and Parkinsonism symptoms with X-linked recessive inheritance pattern and maternal roots traceable to the Panay Islands were sent for a Brain FDG PET Scan. Seven male patients with various movement disorders (dysarthria, face dystonia, Parkinsonism, hemibalismus, involuntary movements and rest tremors) with duration of symptoms from 1 to 5 years underwent a PET scan. All patients had non visualized bilateral putamen, four had hypometabolic caudate nuclei, one had intense (hypermetabolic) caudate nuclei. CT scan and MRI did not show any findings which may explain the movement disorder symptoms. More patients are being collected and gene typing is planned for some patients. Conclusions: This small series of patients demonstrate that patients with the phenotypic characteristics of X

  20. ({sup 18}F)-fluorodeoxyglucose PET/CT in cervix cancer: Lymph node assessment and prognostic/predictive value of primary tumour analysis; Tomographie par emission de positons au ({sup 18}F)-fluorodesoxyglucose dans les cancers du col uterin: evaluation ganglionnaire et valeur pronostique/predictive des donnees de la tumeur primitive

    Energy Technology Data Exchange (ETDEWEB)

    Leseur, J.; Williaume, D.; Le Prise, E.; De Crevoisier, R. [Departement des radiations, centre Eugene-Marquis, rue de la Bataille-Flandres-Dunkerque, CS 44229, 35042 Rennes cedex (France); Devillers, A.; Garin, E. [Service de medecine nucleaire, centre Eugene-Marquis, rue de la Bataille-Flandres-Dunkerque, CS 44229, 35042 Rennes cedex (France); Fougerou, C. [Service de pharmacologie, CHU de Rennes, 35033 Rennes cedex 09 (France); Inserm 0203, centre d' investigations cliniques, CHU de Rennes, 35033 Rennes cedex 09 (France); Universite de Rennes 1, CS 46510, 35065 Rennes cedex (France); Bouriel, C. [Service de radiologie, centre Eugene-Marquis, rue de la Bataille-Flandres-Dunkerque, CS 44229, 35042 Rennes cedex (France); Leveque, J. [Departement de gynecologie et obstetrique, CHU Anne-de-Bretagne, 16, boulevard de Bulgarie, 35203 Rennes cedex 2 (France); Monpetit, E. [Departement des radiations, clinique Oceane, 11, rue du Docteur-Joseph-Audic, Le Tenenio, BP 50020, 56001 Vannes cedex (France); Blanchot, J. [Departement de gynecologie et obstetrique, clinique mutualiste La Sagesse, 4, place Saint-Guenole, CS 44345, 35043 Rennes cedex (France)

    2011-12-15

    Purpose. - In cervix carcinoma: (a) to evaluate the ability of ({sup 18}F)-fluorodeoxyglucose (FDG) positron emission tomography (PET) in the lymph node detection; (b) to investigate the prognostic and predictive value of the primary cervical PET parameters. Patients and methods. - Ninety patients treated for cervix carcinoma and evaluated initially by MRI and FDG PET were included. The performances of FDG-PET for lymph node detection (relatively to the lymph node dissection) have been described (sensitivity, specificity, positive predictive value and negative predictive value). PET tumour parameters analyzed were: maximum standard uptake value (SUV{sub max}), the volume and the maximum diameter. The prognostic and predictive values of these parameters were investigated. The tumour response was evaluated on surgical specimens. Results. - PET detected the cervical tumour with a sensitivity of 97% (mean values: SUV{sub max} = 15.8, volume = 27 mm{sup 3}, maximum diameter = 47). For the detection of the lymph nodes, the values of sensibility, specificity, positive predictive value and negative predictive value were: 86, 56, 69 and 78% in the pelvic, and 90, 67, 50 and 95% for the para-aortic area, respectively. The SUV{sub max} was correlated with histologic response (P = 0.04). The frequency of partial histological response was significantly higher for tumour SUV{sub max}> 10.9 (P = 0.017). The maximum PET diameter and pathologic response had an impact on disease-free survival and overall survival in multivariate analysis (P < 0.05). Conclusion. - PET has high sensitivity in detecting pelvic and para-aortic lymph nodes. Some primary cervical tumour PET parameters are useful as prognostic and predictive factors. (authors)

  1. Temporal lobe deficits in murderers: EEG findings undetected by PET.

    Science.gov (United States)

    Gatzke-Kopp, L M; Raine, A; Buchsbaum, M; LaCasse, L

    2001-01-01

    This study evaluates electroencephalography (EEG) and positron emission tomography (PET) in the same subjects. Fourteen murderers were assessed by using both PET (while they were performing the continuous performance task) and EEG during a resting state. EEG revealed significant increases in slow-wave activity in the temporal, but not frontal, lobe in murderers, in contrast to prior PET findings that showed reduced prefrontal, but not temporal, glucose metabolism. Results suggest that resting EEG shows empirical utility distinct from PET activation findings.

  2. Molecular Imaging in Breast Cancer: From Whole-Body PET/CT to Dedicated Breast PET

    Directory of Open Access Journals (Sweden)

    B. B. Koolen

    2012-01-01

    Full Text Available Positron emission tomography (PET, with or without integrated computed tomography (CT, using 18F-fluorodeoxyglucose (FDG is based on the principle of elevated glucose metabolism in malignant tumors, and its use in breast cancer patients is frequently being investigated. It has been shown useful for classification, staging, and response monitoring, both in primary and recurrent disease. However, because of the partial volume effect and limited resolution of most whole-body PET scanners, sensitivity for the visualization of small tumors is generally low. To improve the detection and quantification of primary breast tumors with FDG PET, several dedicated breast PET devices have been developed. In this nonsystematic review, we shortly summarize the value of whole-body PET/CT in breast cancer and provide an overview of currently available dedicated breast PETs.

  3. 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

  4. The Use of a Novel Approach for the Instrumentation of a Cone-beam Computed Tomography-discernible Lateral Canal in an Unusual Maxillary Incisor: Case Report.

    Science.gov (United States)

    Chaniotis, Antonis; Filippatos, Christos G

    2017-06-01

    Lateral and apical ramifications of the main root canal create potential pathways through which bacteria can spread and remain unaffected by treatment procedures. It is a challenge for the specialty to find techniques that can predictably reach, disinfect, and obturate these ramifications. Here, we report the use of a novel instrumentation approach to aid in the negotiation and management of a lateral canal discernible on cone-beam computed tomography (CBCT) in an unusual maxillary central incisor. A 23-year-old female patient was referred for evaluation and possible treatment of tooth 9. The periapical radiographic examination revealed pulp chamber obliteration, existence of a lateral lesion, and a possible complex internal root canal anatomy. The CBCT evaluation revealed the existence of a lateral lesion, a periapical lesion, an additional distopalatal canal, and a lateral canal exiting at the lateral lesion. The diagnosis of asymptomatic apical and lateral periodontitis of tooth 9 was reached. CBCT-aided access cavity preparation and scouting resulted in the successful negotiation of all canals, main and lateral. A novel instrumentation technique with precurved controlled memory files was used for the mechanical preparation of the lateral canal to a 25/04 enlargement. Obturaton of the lateral canal was achieved with a single gutta-percha cone and AH Plus Root Canal Sealer. At the 2-year follow-up, the patient was asymptomatic, and the 2-dimensional radiographic examinations revealed resolution of both the periapical and the lateral lesions. This case report describes the application of a novel instrumentation technique for the mechanical debridement of an infected lateral canal discernible on CBCT and reinforces the importance of treating the root canals as systems that possesses anatomic intricacies that need to be addressed. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Evaluation of clinial usefulness of 11C-methionine positron emission tomography (11C-MET-PET) as a tool for liver functional imaging

    International Nuclear Information System (INIS)

    Enomoto, Kazuo; Matsui, Yoshifumi; Okazumi, Shinichi

    1994-01-01

    We studied 11 C-MET-PET in 17 clinical cases, 10 patients with obstructive jaundice and 7 normal volunteers, and analyzed its efficacy for the evaluation of hepatic functional reserve in major hepatectomy candidates. Differential absorption ratio (DAR) of 11 C was compared to the hepatic protein synthesis rate (HPS), which is measured as the incorporation rate of 3 H-labeled leucine in protein fraction, using needle biopsied liver specimen obtained from each hepatic segment. In the cases of normal liver function, DAR was well correlated with HPS. Also in jaundice cases with two exceptions, low HPS segment was demonstrated as low DAR segment. Consequently, MET-PET images could clearly provide functional liver imaging. After injection of 11 C-MET, the increase in rate of radioactivity of 11 C in plasma protein fraction was higher in jaundice cases than in normal volunteers, which is in accord with the results of our former study that cholestatic liver has accelerated protein synthesis rate. In summary, since 11 C-MET-PET could demonstrate liver functional imaging, it might be a possible tool for liver function assessment in major hepatectomy candidates. (author)

  6. PET/CT in Radiation Therapy Planning

    DEFF Research Database (Denmark)

    Specht, Lena; Berthelsen, Anne Kiil

    2018-01-01

    Radiation therapy (RT) is an important component of the management of lymphoma patients. Most lymphomas are metabolically active and accumulate 18F-fluorodeoxyglucose (FDG). Positron emission tomography with computer tomography (PET/CT) imaging using FDG is used routinely in staging and treatment...

  7. Investigation progress of PET reporter gene imaging

    International Nuclear Information System (INIS)

    Chen Yumei; Huang Gang

    2006-01-01

    Molecular imaging for gene therapy and gene expression has been more and more attractive, while the use of gene therapy has been widely investigated and intense research have allowed it to the clinical setting in the last two-decade years. In vivo imaging with positron emission tomography (PET) by combination of appropriate PET reporter gene and PET reporter probe could provide qualitative and quantitative information for gene therapy. PET imaging could also obtain some valuable parameters not available by other techniques. This technology is useful to understand the process and development of gene therapy and how to apply it into clinical practice in the future. (authors)

  8. Dynamic observation by PET in epilepsy

    International Nuclear Information System (INIS)

    Shimizu, Hiroyuki; Ishijima, Buichi; Iio, Masaaki.

    1990-01-01

    Before the era when positron emission tomography (PET) has emerged, much controversy has existed concerning regional cerebral blood flow in partial epilepsy. In 1979, PET revealed that cerebral blood flow is decreased during the interictal period, but is remarkably increased in the intraictal phase. In this paper, historical process of dynamic observation in epilepsy is reviewed. Potential use and limitations of PET in the clinical setting are discussed in view of the scanning methods and the relationships between PET and electroencephalograms, magnetic resonance imaging, and surgical treatment. (N.K.) 106 refs

  9. Decay correction methods in dynamic PET studies

    International Nuclear Information System (INIS)

    Chen, K.; Reiman, E.; Lawson, M.

    1995-01-01

    In order to reconstruct positron emission tomography (PET) images in quantitative dynamic studies, the data must be corrected for radioactive decay. One of the two commonly used methods ignores physiological processes including blood flow that occur at the same time as radioactive decay; the other makes incorrect use of time-accumulated PET counts. In simulated dynamic PET studies using 11 C-acetate and 18 F-fluorodeoxyglucose (FDG), these methods are shown to result in biased estimates of the time-activity curve (TAC) and model parameters. New methods described in this article provide significantly improved parameter estimates in dynamic PET studies

  10. FDG-PET in Follicular Lymphoma Management

    Directory of Open Access Journals (Sweden)

    C. Bodet-Milin

    2012-01-01

    Full Text Available 18-Fluoro-deoxyglucose positron emission tomography/computerised tomography (FDG PET/CT is commonly used in the management of patients with lymphomas and is recommended for both initial staging and response assessment after treatment in patients with diffuse large B-cell lymphoma and Hodgkin lymphoma. Despite the FDG avidity of follicular lymphoma (FL, FDG PET/CT is not yet applied in standard clinical practice for patients with FL. However, FDG PET/CT is more accurate than conventional imaging for initial staging, often prompting significant management change, and allows noninvasive characterization to guide assessment of high-grade transformation. For restaging, FDG PET/CT assists in distinguishing between scar tissue and viable tumors in residual masses and a positive PET after induction treatment would seem to predict a shorter progression-free survival.

  11. Guidelines for 18F-FDG PET and PET-CT imaging in paediatric oncology

    DEFF Research Database (Denmark)

    Stauss, J.; Franzius, C.; Pfluger, T.

    2008-01-01

    tomography ((18)F-FDG PET) in paediatric oncology. The Oncology Committee of the European Association of Nuclear Medicine (EANM) has published excellent procedure guidelines on tumour imaging with (18)F-FDG PET (Bombardieri et al., Eur J Nucl Med Mol Imaging 30:BP115-24, 2003). These guidelines, published...

  12. The efficacy of preoperative positron emission tomography-computed tomography (PET-CT) for detection of lymph node metastasis in cervical and endometrial cancer: clinical and pathological factors influencing it.

    Science.gov (United States)

    Nogami, Yuya; Banno, Kouji; Irie, Haruko; Iida, Miho; Kisu, Iori; Masugi, Yohei; Tanaka, Kyoko; Tominaga, Eiichiro; Okuda, Shigeo; Murakami, Koji; Aoki, Daisuke

    2015-01-01

    We studied the diagnostic performance of (18)F-fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography in cervical and endometrial cancers with particular focus on lymph node metastases. Seventy patients with cervical cancer and 53 with endometrial cancer were imaged with (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography before lymphadenectomy. We evaluated the diagnostic performance of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography using the final pathological diagnoses as the golden standard. We calculated the sensitivity, specificity, positive predictive value and negative predictive value of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography. In cervical cancer, the results evaluated by cases were 33.3, 92.7, 55.6 and 83.6%, respectively. When evaluated by the area of lymph nodes, the results were 30.6, 98.9, 55.0 and 97.0%, respectively. As for endometrial cancer, the results evaluated by cases were 50.0, 93.9, 40.0 and 95.8%, and by area of lymph nodes, 45.0, 99.4, 64.3 and 98.5%, respectively. The limitation of the efficacy was found out by analyzing it by the region of the lymph node, the size of metastatic node, the historical type of tumor in cervical cancer and the prevalence of lymph node metastasis. The efficacy of positron emission tomography/computed tomography regarding the detection of lymph node metastasis in cervical and endometrial cancer is not established and has limitations associated with the region of the lymph node, the size of metastasis lesion in lymph node and the pathological type of primary tumor. The indication for the imaging and the interpretation of the results requires consideration for each case by the pretest probability based on the information obtained preoperatively. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. {sup 18}F-FDG PET and PET/CT in Burkitt's lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Karantanis, Dimitrios, E-mail: dkarantanis@nuclmed.ne [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States); Durski, Jolanta M.; Lowe, Val J.; Nathan, Mark A.; Mullan, Brian P. [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States); Georgiou, Evangelos [Medical Physics Department, Medical School, University of Athens (Greece); Johnston, Patrick B. [Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN (United States); Wiseman, Gregory A. [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States)

    2010-07-15

    Objective: To explore the value of {sup 18}F fluorodeoxy-glucose (FDG) positron emission tomography (PET) in Burkitt's lymphoma. Methods: All Burkitt's lymphoma patients referred for FDG PET or FDG PET/computed tomography (CT) exams at our institution from June 2003 to June 2006 were included. Selected patients were followed and clinical information was reviewed retrospectively. Results from FDG PET-PET/CT, as blindly reviewed by a consensus of two experienced readers, were compared with the status of the disease as determined by other laboratory, clinical and imaging exams and clinical follow-up. FDG PET-PET/CT results were classified as true positive or negative and false positive or negative. The degree of FDG uptake in the positive lesions was semiquantified as maximum standard uptake value (SUVmax). Results: Fifty-seven FDG PET-PET/CT exams were done in 15 patients. Seven exams were done for initial staging, 8 during and 14 after the completion of therapy, and 28 for disease surveillance. For nodal disease FDG PET-PET/CT was true positive in 8, true negative in 47 and false positive in 2 exams (sensitivity 100%, specificity 96%). For extranodal disease FDG PET-PET/CT was true positive in 6, true negative in 48 and false positive in 3 exams (sensitivity 100%, specificity 94%). The mean SUVmax for the positive nodal lesions was 15.7 (range 6.9-21.7, median 18.5) and for extranodal lesions was 14.2 (range 6.2-24.3, median 12.4). Conclusions: FDG PET-PET/CT is sensitive for the detection of viable disease in Burkitt's lymphoma. Affected areas demonstrated high degree of uptake that was reversible upon successful implementation of treatment.

  14. 18F-FDG PET and PET/CT in Burkitt's lymphoma

    International Nuclear Information System (INIS)

    Karantanis, Dimitrios; Durski, Jolanta M.; Lowe, Val J.; Nathan, Mark A.; Mullan, Brian P.; Georgiou, Evangelos; Johnston, Patrick B.; Wiseman, Gregory A.

    2010-01-01

    Objective: To explore the value of 18 F fluorodeoxy-glucose (FDG) positron emission tomography (PET) in Burkitt's lymphoma. Methods: All Burkitt's lymphoma patients referred for FDG PET or FDG PET/computed tomography (CT) exams at our institution from June 2003 to June 2006 were included. Selected patients were followed and clinical information was reviewed retrospectively. Results from FDG PET-PET/CT, as blindly reviewed by a consensus of two experienced readers, were compared with the status of the disease as determined by other laboratory, clinical and imaging exams and clinical follow-up. FDG PET-PET/CT results were classified as true positive or negative and false positive or negative. The degree of FDG uptake in the positive lesions was semiquantified as maximum standard uptake value (SUVmax). Results: Fifty-seven FDG PET-PET/CT exams were done in 15 patients. Seven exams were done for initial staging, 8 during and 14 after the completion of therapy, and 28 for disease surveillance. For nodal disease FDG PET-PET/CT was true positive in 8, true negative in 47 and false positive in 2 exams (sensitivity 100%, specificity 96%). For extranodal disease FDG PET-PET/CT was true positive in 6, true negative in 48 and false positive in 3 exams (sensitivity 100%, specificity 94%). The mean SUVmax for the positive nodal lesions was 15.7 (range 6.9-21.7, median 18.5) and for extranodal lesions was 14.2 (range 6.2-24.3, median 12.4). Conclusions: FDG PET-PET/CT is sensitive for the detection of viable disease in Burkitt's lymphoma. Affected areas demonstrated high degree of uptake that was reversible upon successful implementation of treatment.

  15. Feasibility of breathing-adapted PET/CT imaging for radiation therapy of Hodgkin lymphoma

    DEFF Research Database (Denmark)

    Aznar, M C; Andersen, Flemming; Berthelsen, A K

    2011-01-01

    Aim: Respiration can induce artifacts in positron emission tomography (PET)/computed tomography (CT) images leading to uncertainties in tumour volume, location and uptake quantification. Respiratory gating for PET images is now established but is not directly translatable to a radiotherapy setup....... in PET/CT images. These results suggest that advanced therapies (such as SUV-based dose painting) will likely require breathing-adapted PET images and that the relevant SUV thresholds are yet to be investigated....

  16. Feasibility of breathing-adapted PET/CT imaging for radiation therapy of Hodgkin lymphoma

    DEFF Research Database (Denmark)

    Aznar, M C; Andersen, Flemming; Berthelsen, A K

    2011-01-01

    Aim: Respiration can induce artifacts in positron emission tomography (PET)/computed tomography (CT) images leading to uncertainties in tumour volume, location and uptake quantification. Respiratory gating for PET images is now established but is not directly translatable to a radiotherapy setup....... uptake in PET/CT images. These results suggest that advanced therapies (such as SUV-based dose painting) will likely require breathing-adapted PET images and that the relevant SUV thresholds are yet to be investigated....

  17. Current status and future perspective of PET

    International Nuclear Information System (INIS)

    Lee, Myung Chul

    2002-01-01

    Positron Emission Tomography (PET) is a nuclear medicine imaging modality that consists of systemic administration to a subject of a radiopharmaceutical labeled with a positron-emitting radionuclide. Following administration, its distribution in the organ or structure under study can be assessed as a function of time and space by (1) detecting the annihilation radiation resulting from the interaction of the positrons with matter, and (2) reconstructing the distribution of the radioactivity from a series of that used in computed tomography (CT). The nuclides most generally exhibit chemical properties that render them particularly desirable in physiological studies. The radionuclides most widely used in PET are F-18, C-11, O-15 and N-13. Regarding to the number of the current PET Centers worldwide (based on ICP data), more than 300 PET Centers were in operation in 2000. The use of PET technology grew rapidly compared to that in 1992 and 1996, particularly in the USA, which demonstrates a three-fold rise in PET installations. In 2001, 194 PET Centers were operating in the USA. In 1994, two clinical and research-oriented PET Centers at Seoul National University Hospital and Samsung Medical Center, was established as the first dedicated PET and Cyclotron machines in Korea, followed by two more PET facilities at the Korea Cancer Center Hospital, Ajou Medical Center, Yonsei University Medical Center, National Cancer Center and established their PET Center. Catholic Medical School and Pusan National University Hospital have finalized a plan to install PET machine in 2002, which results in total of nine PET Centers in Korea. Considering annual trends of PET application in four major PET centers in Korea in Asan Medical Center recent six years (from 1995 to 2000), a total of 11,564 patients have been studied every year and the number of PET studies has shown steep growth year upon year. We had, 1,020 PET patients in 1995. This number increased to 1,196, 1,756, 2,379, 3

  18. Determination of the dose equivalent Hp(0.07) in hands of occupationally exposed personnel in the practice of proton emission tomography (PET/CT); Determinacion de la dosis equivalente Hp(0.07) en manos de trabajadores ocupacionalmente expuestos en la practica de Tomografia por Emision de Positrones (PET/CT)

    Energy Technology Data Exchange (ETDEWEB)

    Lea, D. [Servicio de Radiofisica Sanitaria, Unidad de Tecnologia Nuclear, Instituto Venezolano de Investigaciones Cientificas, Ministerio de Ciencia y Tecnologia, Km 11 Carretera Panamerican, Altos del Pipe, Caracas (Venezuela); Ruiz, N.; Esteves, L. [Centro Diagnostico Docente Las Mercedes, Calle Paris cruce con calle Caroni, Edif. CDD, Las Mercedes, Caracas (Venezuela)]. e-mail: dlea@ivic.ve

    2006-07-01

    In Venezuela recently it was implanted the Positron Emission Tomography technique (PET) with the perspective of implanting it at national level. Even when in our country practices it of nuclear medicine it exists from early of 70, there is not experience in the determination of the occupational doses by exposure to the external radiation in hands. By this reason, a concern exists in the workers of the centers of nuclear medicine where it is practiced the Positron Emission Tomography technique. In absence of the TLD dosimetry to measure dose in hands in our country, measurements of the dose equivalent of the workers of the PET national reference center were made, using a detector of hands type diode. It was determined the dose in hands in terms of dose equivalent Hp(0.07) in two work positions, that is: the corresponding to the transfer of the receiving vial of ({sup 18}F) FDG to the shield, quality control and uni doses division. The second work position corresponds the person in charge of administering, via intravenous, the ({sup 18}F) FDG. In this work it realizes the dose equivalent in hands Hp(0.07) measures in each one of the work positions before described by daily production. The informed doses correspond to a total average produced activity of 20.4 GBq (550 mCi). The results of the measurements in terms of dose equivalent in hands Hp(0.07) correspond to 2.1 {+-} 20% mSv in the work position of division and 0.4 {+-} 10% mSv in the position of injection of the radioactive material. At short term this foreseen until 4 productions per week, what means an annual dose equivalent Hp(0.07) in hands of 400 mSv approximately, without taking into account abnormal situations as its are spills of the ({sup 18}F) FDG in the work place. This work is the starting point so that the regulatory authority settles down, in Venezuela, dose restrictions in the PET practices and implant, in the centers of nuclear medicine, an optimization politics of this practice in conformity

  19. 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.).

  20. 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.)

  1. Positron emission tomography

    International Nuclear Information System (INIS)

    Pavuk, M.

    2003-12-01

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

  2. 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

  3. Utility of PET in gynecological cancer

    International Nuclear Information System (INIS)

    Choi, Chang Woon

    2002-01-01

    Clinical application of positron emission tomography (PET) is rapidly increasing for the detection and staging of cancer at whole-body studies performed with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG). Although many cancers can be detected by FDG-PET, there has been limited clinical experience with FDG-PET for the detection of gynecological cancers including malignancies in uterus and ovary. FDG-PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterization of indeterminate soft-tissue masses. Most gynecological cancers need to surgical management. FDG-PET can improve the selection of patients for surgical treatment and thereby reduce the morbidity and mortality associated with inappropriate surgery. FDG-PET is also useful for the early detection of recurrence and the monitoring of therapeutic effect. In this review, I discuss the clinical feasibility and imitations of this imaging modality in patients with gynecological cancers

  4. PET-COMPTON System. Comparative evaluation with PET System using Monte Carlo Simulation

    International Nuclear Information System (INIS)

    Diaz Garcia, Angelina; Arista Romeu, Eduardo; Abreu Alfonso, Yamiel; Leyva Fabelo, Antonio; Pinnera HernAndez, Ibrahin; Bolannos Perez, Lourdes; Rubio Rodriguez, Juan A.; Perez Morales, Jose M.; Arce Dubois, Pedro; Vela Morales, Oscar; Willmott Zappacosta, Carlos

    2012-01-01

    Positron Emission Tomography (PET) in small animals has actually achieved spatial resolution round about 1 mm and currently there are under study different approaches to improve this spatial resolution. One of them combines PET technology with Compton Cameras. This paper presents the idea of the so called PET-Compton systems and has included comparative evaluation of spatial resolution and global efficiency in both PET and PET-Compton system by means of Monte Carlo simulations using Geant4 code. Simulation was done on a PET-Compton system made-up of LYSO-LuYAP scintillating detectors of particular small animal PET scanner named Clear-PET and for Compton detectors based on CdZnTe semiconductor. A group of radionuclides that emits a positron (e+) and quantum almost simultaneously and fulfills some selection criteria for their possible use in PET-Compton systems for medical and biological applications were studied under simulation conditions. By means of analytical reconstruction using SSRB (Single Slide Rebinning) method were obtained superior spatial resolution in PET-Compton system for all tested radionuclides (reaching sub-millimeter values of for 22Na source). However this analysis done by simulation have shown limited global efficiency values in PET-Compton system (in the order of 10 -5 -10 -6 %) instead of values around 5*10 -1 % that have been achieved in PET system. (author)

  5. PET/CT-guided interventional procedures: rationale, justification, initial study, and research plan

    Energy Technology Data Exchange (ETDEWEB)

    Wong, K.; Rahill, J.; Cleary, K. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Petrillo, S.; Earl-Graef, D. [Dept. of Radiology, Georgetown Univ. Hospital, MedStar Health, Washington, DC (United States); Banovac, F.; Levy, E. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Dept. of Radiology, Georgetown Univ. Hospital, MedStar Health, Washington, DC (United States); Shekhar, R. [Dept. of Radiology, Univ. of Maryland Medical Center, Baltimore, MD (United States)

    2007-06-15

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

  6. GePEToS: A Geant4 Monte Carlo simulation package for positron emission tomography

    International Nuclear Information System (INIS)

    Jan, Sebastien; Collot, Johann; Gallin-Martel, Marie-Laure; Martin, Philippe; Mayet, Frederic; Tournefier, Edwige

    2003-01-01

    GePEToS is a simulation framework developed over the last few years for assessing the instrumental performance of future PET scanners. It is based on Geant4, written in Object- Oriented C++ and runs on Linux platforms. The validity of GePEToS has been tested on the well-known Siemens ECAT EXACT HR+ camera. The results of two application examples are presented: the design optimization of a liquid Xe μPET camera dedicated to small animal imaging as well as the evaluation of the effect of a strong axial magnetic field on the image resolution of a Concorde P4 μPET camera. Index Terms-Positron Emission Tomography, Monte Carlo Simulation, Geant 4. (authors)

  7. Evaluation of coronary blood flow reserve by 13N-NH3 positron emission computed tomography (PET) with dipyridamole in the treatment of hypertension with the ACE inhibitor (Cilazapril)

    International Nuclear Information System (INIS)

    Masuda, Daisuke; Nohara, Ryuji; Tamaki, Nagara

    2000-01-01

    The purpose of this study was to evaluate the effect of treatment with an angiotensin-converting enzyme (ACE) inhibitor (Cilazapril) for early hypertensive patients in terms of coronary blood flow reserve evaluated by 13 NH 3 -positron emission tomography (PET). Before and after 12 weeks of ACE inhibitor treatment, 13 NH 3 -PET with dipyridamole provocation test was performed, and definite myocardial perfusion and coronary flow reserve (CFR) were calculated. Compared to our normal subjects previously reported (2.61±0.74), average coronary flow reserve was decreased (1.70±0.64 in hypertensive patients), and improved after treatment (1.77±0.52), but not significantly. Of 12 patients, five (42%) showed improved coronary flow reserve from 1.34 to 1.99 without a significant change in the resting flow. Only one patient (8%) showed deterioration after the ACE inhibitor treatment. The coronary vascular resistance (CVR) after ACE inhibitor treatment of the patients with CFR <2.0 decreased significantly compared with those with CFR ≥2.0 (p<0.03). These results indicate that hypertensive patients at the early stage show decreased coronary flow reserve despite having normal resting flow. Treatment with an ACE inhibitor (Cilazapril) for 12 weeks improved coronary flow reserve in 42% of our patients. The CVR of the patients with CFR <2.0 showed improvement compared to those with CFR ≥2.0. This result indicates that an ACE inhibitor (e.g., Cilazapril) should be one of the choices for improving CFR if hypertensive patients in early stage show signs of ischemia or diastolic dysfunction, which may be one of the sequels of reserve restriction. (author)

  8. A Micro-computed Tomography Evaluation of the Shaping Ability of Two Nickel-titanium Instruments, HyFlex EDM and ProTaper Next.

    Science.gov (United States)

    Venino, Pier Matteo; Citterio, Claudio Luigi; Pellegatta, Alberto; Ciccarelli, Marta; Maddalone, Marcello

    2017-04-01

    The aim of this study was to evaluate and compare, by means of micro-computed tomography imaging, the shaping ability of ProTaper Next (PTN) and the novel HyFlex EDM (HFEDM) instruments. Forty teeth were randomly divided into 2 groups and prepared with PTN or HFEDM. Root canal transportation and centering ratio were evaluated in mesiodistal and buccolingual directions at 5 levels (at the midpoint of the apical, middle, and coronal thirds and at the boundaries between them). Variations in volume, surface, and cross-sectional shape were measured for the apical, middle, and coronal thirds. The null hypotheses were that no differences existed between the 2 groups. The D'Agostino-Pearson test (α = .05) was conducted to assess the normality of the data sets. The distributions were compared by using the Mann-Whitney test (α = .05). Statistically significant differences (P < .005) were recorded only for buccolingual canal transportation and centering ratio at the section between the middle and coronal thirds, where HFEDM files were superior. HFEDM and PTN files were similarly effective, and both safely prepared the root canals, respecting their original anatomies. HFEDM files performed better in terms of buccolingual canal transportation and centering ratio at the section between the middle and coronal thirds. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Appropriateness criteria of FDG PET/CT in oncology

    International Nuclear Information System (INIS)

    Agrawal, Archi; Rangarajan, Venkatesh

    2015-01-01

    18 Fluorine-2-fluoro-2-Deoxy-d-glucose ( 18 F-FDG) positron emission tomography/computerized tomography (PET/CT) is a well-established functional imaging method widely used in oncology. In this article, we have incorporated the various indications for 18 FDG PET/CT in oncology based on available evidence and current guidelines. Growing body of evidence for use of 18 FDG PET/CT in select tumors is also discussed. This article attempts to give the reader an overview of the appropriateness of using 18 F-FDG PET/CT in various malignancies

  10. FDG-PET Assessment of Other Gynecologic Cancers.

    Science.gov (United States)

    Faria, Silvana; Devine, Catherine; Viswanathan, Chitra; Javadi, Sanaz; Korivi, Brinda Rao; Bhosale, Priya R

    2018-04-01

    PET and PET/computed tomography play a role in the staging, monitoring of response to therapy, and surveillance for cervical and ovarian cancers. Currently, it is also an integral part of the assessment of patients with endometrial cancer and other gynecologic malignancies, such as vaginal and vulvar cancers and uterine sarcomas. In this article, we discuss in detail and highlight the potential role of PET and PET/computed tomography in evaluating these gynecologic malignancies using illustrative cases with relevant imaging findings. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Business administration of PET facilities. A nationwide survey for prices of PET screening and a cost analysis of three facilities

    International Nuclear Information System (INIS)

    Mitsutake, Naohiro; Fujii, Ryo; Oku, Shinya; Furui, Yuji; Yasunaga, Hideo

    2007-01-01

    The purpose of this study is to analyze the business administration of positron emission tomography (PET) facilities based on the survey of the price of PET cancer screening and cost analysis of PET examination. The questionnaire survey of the price of PET cancer screening was implemented for all PET facilities in Japan. Cost data of PET examination, including fixed costs and variable costs, were obtained from three different medical institutions. The marked price of the PET cancer screening was yen111,499 in average, and the most popular range of prices was between yen80,000 and yen90,000. Costs of PET per examination were accounted for yen110,675, yen79,158 and yen111,644 in facility A, B and C, respectively. The results suggested that facilities with two or more PET/CT per a cyclotron could only secure profits. In Japan, the boom in PET facility construction could not continue in accordance with increasing number of PET facilities. It would become more essential to analyze the appropriate distribution of PET facilities and the adequate amount of PET procedures from the perspective of efficient utilization of the PET equipments and supply of PET-related healthcare. (author)

  12. Revisiting the prognostic value of preoperative 18F-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET) in early-stage (I and II) non-small cell lung cancers (NSCLC)

    International Nuclear Information System (INIS)

    Agarwal, Mohit; Brahmanday, Govinda; Bajaj, Sunil K.; Wong, Ching-Yee Oliver; Ravikrishnan, K.P.

    2010-01-01

    The aims were to determine if the maximum standardized uptake value (SUV max ) of the primary tumor as determined by preoperative 18 F-fluoro-2-deoxyglucose ( 18 F-FDG) positron emission tomography (PET) is an independent predictor of overall survival and to assess its prognostic value after stratification according to pathological staging. A retrospective clinicopathologic review of 363 patients who had a preoperative 18 F-FDG PET done before undergoing attempted curative resection for early-stage (I and II) non-small cell lung cancer (NSCLC) was performed. Patients who had received any adjuvant or neoadjuvant chemotherapy or radiation therapy were excluded. The primary outcome measure was duration of overall survival. Receiver-operating characteristic (ROC) curves were plotted to find out the optimal cutoff values of SUV max yielding the maximal sensitivity plus specificity for predicting the overall survival. Survival curves stratified by median SUV max and optimal cutoff SUV max were estimated by the Kaplan-Meier method and statistical differences were assessed using the log-rank test. Multivariate proportional hazards (Cox) regression analyses were applied to test the SUV max 's independency of other prognostic factors for the prediction of overall survival. The median duration of follow-up was 981 days (2.7 years). The median SUV max was 5.9 for all subjects, 4.5 for stage IA, 8.4 for stage IB, and 10.9 for stage IIB. The optimal cutoff SUV max was 8.2 for all subjects. No optimal cutoff could be established for specific stages. In univariate analyses, each doubling of SUV max [i.e., each log (base 2) unit increase in SUV max ] was associated with a 1.28-fold [95% confidence interval (CI): 1.03-1.59, p = 0.029] increase in hazard of death. Univariate analyses did not show any significant difference in survival by SUV max when data were stratified according to pathological stage (p = 0.119, p = 0.818, and p = 0.882 for stages IA, IB, and IIB, respectively

  13. 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

  14. 77 FR 71802 - Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    Science.gov (United States)

    2012-12-04

    ... Positron Emission Tomography (PET) Drugs.'' The guidance is intended to assist manufacturers of PET drugs... one self-addressed adhesive label to assist that office in processing your requests. See the... ``Investigational New Drug Applications for Positron Emission Tomography (PET) Drugs.'' The guidance summarizes the...

  15. Contrast-enhanced fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography in mediastinal T-cell lymphoma with superior vena cava syndrome

    International Nuclear Information System (INIS)

    Santhosh, Sampath; Gorla, Arun Kumar Reddy; Bhattacharya, Anish; Varma, Subhash Chander; Mittal, Bhagwant Rai

    2016-01-01

    Positron emission tomography-computed tomography (PET/CT) is a routine investigation for the staging of lymphomas. Contrast-enhanced computed tomography is mandatory whenever parenchymal lesions, especially in the liver and spleen are suspected. We report a rare case of primary mediastinal T-cell lymphoma evaluated with contrast-enhanced PET/CT that showed features of superior vena cava syndrome

  16. Imaging opiate receptors by positron tomography (PET): Evaluation by displacement of 3-Acetyl-6-Deoxy-6-Beta-/sup 18/F-flouronaltrexone with active and inactive naloxone

    International Nuclear Information System (INIS)

    Larson, S.M.; Channing, M.A.; Rice, K.R.; Pert, C.B.; Eckelman, W.C.; Burke, T.R.; Bennett, J.M.; Carson, R.E.; Di Chiro, G.

    1985-01-01

    We recently reported the development of a new radiopharmaceutical for in vivo PET imaging of opiate receptors, 3-acetyl-6-deoxy-6-Beta-/sup 18/F-fluoronaltrexone: 3-acetylcyclofoxy, or /sup 18/F-ACF. These studies involved displacement of /sup 18/F-ACF from sites of uptake in the baboon sub-cortical gray matter, and provided strong proof of the opiate receptor specificity of the tracer. We now report on the anatomic localization of /sup 18/F-ACF in the sub-cortical grapy matter of baboon, and the kinetics of uptake and displacement of the tracer. /sup 18/F-ACF was prepared from the known 3-acetyl-6-alpha-naltrexol via the triflate, using /sup 18/F produced by neutron bombardment of /sup 6/Li/sub 2/CO/sub 3/. Anesthetized baboons were imaged after injection of /sup 18/F-ACF (sp.ac.=20Ci/mmol), using the NIH NEUROPET, a high resolution PET scanner. After bolus injection, the initial distribution to brain was rapid with peak uptake at 6 minutes post-injection. Clearance from opiate receptor rich regions of thalamus and basal ganglia was gradual, but after injection of active (but not after inactive), naloxone, clearance from these regions more than doubled. In non-opiate rich regions, (e.g. cerebellum), the predominant component of clearance was equally rapid with or without the active naloxone. Displacement studies of positron labelled ligands provide a powerful tool for non-invasive study of opiate receptor in living primates

  17. (18)F-FDG PET/CT in a rare case of Stewart-Treves syndrome

    DEFF Research Database (Denmark)

    Jensen, Mads Radmer; Friberg, Lars; Karlsmark, Tonny

    2011-01-01

    The aim of this article is to illustrate the possible applications of (18)F-fluorodeoxyglucose positron emission tomography/computer tomography ((18)F-FDG PET/CT) in chronic extremity lymphedema and its complications....

  18. Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

    International Nuclear Information System (INIS)

    Jung, Jin Ho; Choi, Yong; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun; Oh, Chang Hyun; Park, Hyun-wook; Kim, Kyung Min; Kim, Jong Guk

    2015-01-01

    Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

  19. Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jin Ho; Choi, Yong, E-mail: ychoi.image@gmail.com; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun [Department of Electronic Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 121-742 (Korea, Republic of); Oh, Chang Hyun; Park, Hyun-wook [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Kyung Min; Kim, Jong Guk [Korea Institute of Radiological and Medical Science, 75 Nowon-ro, Nowon-gu, Seoul 139-709 (Korea, Republic of)

    2015-05-15

    Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

  20. Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis

    International Nuclear Information System (INIS)

    Jin, H.; Yuan, L.; Li, C.; Kan, Y.; Yang, J.; Hao, R.

    2014-01-01

    The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

  1. Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis.

    Science.gov (United States)

    Jin, H; Yuan, L; Li, C; Kan, Y; Hao, R; Yang, J

    2014-03-01

    The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

  2. Usefulness of Integrated PET/MRI in Head and Neck Cancer: A Preliminary Study

    International Nuclear Information System (INIS)

    Lee, Soo Jin; Seo, Hyo Jung; Cheon, Gi Jeong; Kim, Ji Hoon; Kim, E. Edmund; Kang, Keon Wook; Paeng, Jin Chul; Chung, Junekey; Lee, Dong Soo

    2014-01-01

    The new modality of an integrated positron emission tomography/magnetic resonance imaging (PET/MRI) has recently been introduced but not validated. Our objective was to evaluate clinical performance of 18 F-fluoro-2-deoxyglucose ( 18 F-FDG) PET/MRI in patients with head and neck cancer. This retrospective study was conducted between January 2013 and February 2013. Ten patients (eight men, two women; mean age, 61.4±13.4 years) with histologically proven head and neck tumors were enrolled.Whole-body PET/MRI and regional positron emission tomography (PET) with dedicated MRI were sequentially obtained. Maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume, total lesion glycolysis and contrast enhancement were analyzed. A total of ten whole-body positron emission tomography (PET), ten regional positron emission tomography (PET), ten dedicated MRI and ten regional PET/gadolinium-enhanced T1-weighted (Gd)-MRI images were analyzed for initial staging. Two nuclear medicine physicians analyzed positron emission tomography (PET) and PET/MRI with a consensus. One radiologist analyzed dedicated MRI. The primary lesions and number of metastatic lymph nodes analyzed from each image were compared. Eight patients were diagnosed with head and neck cancer (one tongue cancer, four tonsillar cancers, one nasopharyngeal cancer and two hypopharyngeal cancers) by histological diagnosis. Two benign tumors (pleomorphic adenoma and Warthin tumor) were diagnosed with surgical operation. Whole-body positron emission tomography (PET) and regional positron emission tomography (PET) attenuated by MRI showed good image quality for the lesion detection. Whole-body positron emission tomography (PET) and regional positron emission tomography (PET) detected ten primary sites and compensated for a missed lesion on dedicated MRI. A discordant number of suspicious lymph node metastases was noted according to the different images; 22, 16, 39 and 40 in the whole-body positron

  3. Development of ''Eminence STARGATE'' PET/CT system

    International Nuclear Information System (INIS)

    Okazaki, Masato; Inoue, Yoshihiro; Amano, Masaharu

    2009-01-01

    A PET/CT system, the combination of a PET (Positron Emission Tomography) system with an X-ray CT system, has been widely used in recent years. Our newly developed ''Eminence STARGATE'' PET/CT system allows the PET gantry and the X-ray CT gantry to move independently. This advantage provides high flexibility for PET examination and X-ray CT examination and also eases a patient's psychological anxiety about closed spaces. The system has a 16-slice X-ray CT scanner. (author)

  4. PET imaging in pediatric neuroradiology: current and future applications

    International Nuclear Information System (INIS)

    Kim, Sunhee; Salamon, Noriko; Jackson, Hollie A.; Blueml, Stefan; Panigrahy, Ashok

    2010-01-01

    Molecular imaging with positron emitting tomography (PET) is widely accepted as an essential part of the diagnosis and evaluation of neoplastic and non-neoplastic disease processes. PET has expanded its role from the research domain into clinical application for oncology, cardiology and neuropsychiatry. More recently, PET is being used as a clinical molecular imaging tool in pediatric neuroimaging. PET is considered an accurate and noninvasive method to study brain activity and to understand pediatric neurological disease processes. In this review, specific examples of the clinical use of PET are given with respect to pediatric neuroimaging. The current use of co-registration of PET with MR imaging is exemplified in regard to pediatric epilepsy. The current use of PET/CT in the evaluation of head and neck lymphoma and pediatric brain tumors is also reviewed. Emerging technologies including PET/MRI and neuroreceptor imaging are discussed. (orig.)

  5. PET imaging in pediatric neuroradiology: current and future applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sunhee [Children' s Hospital of Pittsburgh of UPMC, Department of Radiology, Pittsburgh, PA (United States); Salamon, Noriko [UCLA David Geffen School of Medicine at UCLA, Department of Radiology, Ronald Reagan UCLA Medical Center, Los Angeles, CA (United States); Jackson, Hollie A.; Blueml, Stefan [Keck School of Medicine of USC, Department of Radiology, Childrens Hospital Los Angeles, Los Angeles, CA (United States); Panigrahy, Ashok [Children' s Hospital of Pittsburgh of UPMC, Department of Radiology, Pittsburgh, PA (United States); Keck School of Medicine of USC, Department of Radiology, Childrens Hospital Los Angeles, Los Angeles, CA (United States)

    2010-01-15

    Molecular imaging with positron emitting tomography (PET) is widely accepted as an essential part of the diagnosis and evaluation of neoplastic and non-neoplastic disease processes. PET has expanded its role from the research domain into clinical application for oncology, cardiology and neuropsychiatry. More recently, PET is being used as a clinical molecular imaging tool in pediatric neuroimaging. PET is considered an accurate and noninvasive method to study brain activity and to understand pediatric neurological disease processes. In this review, specific examples of the clinical use of PET are given with respect to pediatric neuroimaging. The current use of co-registration of PET with MR imaging is exemplified in regard to pediatric epilepsy. The current use of PET/CT in the evaluation of head and neck lymphoma and pediatric brain tumors is also reviewed. Emerging technologies including PET/MRI and neuroreceptor imaging are discussed. (orig.)

  6. Use of positron emission tomography in colorectal cancer

    International Nuclear Information System (INIS)

    Gonzalez E, Patricio; Jofre E, Josefina; Massardo V, Teresa; Humeres, Pamela; Canessa G, Jose; Sierralta C, Paulina

    2002-01-01

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

  7. Positron emission tomography in the evaluation of subdural hematomas

    International Nuclear Information System (INIS)

    Ericson, K.; Bergstroem, M.; Eriksson, L.

    1980-01-01

    Fifteen patients with 21 subdural effusions were investigated both with transmission computer assisted tomography (CAT) and positron emission tomography (PET). The tracer in the emission studies was 68 Ga-EDTA. Twelve lesions were visualized both with CAT and PET. Five lesions that were negative or doubtful on CAT were visualized with PET, whereas four lesions negative or doubtful on PET were demonstrated by CAT. The two methods complement each other due to the fact that they are based on different mechanisms: CAT mainly on attenuation of the fluid collection. PET on isotope accumulation, particularly in the hematoma membranes

  8. Importance of PET/CT for imaging of colorectal cancer

    International Nuclear Information System (INIS)

    Meinel, F.G.; Schramm, N.; Graser, A.; Reiser, M.F.; Rist, C.; Haug, A.R.

    2012-01-01

    Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has emerged as a very useful imaging modality in the management of colorectal carcinoma. Data from the literature regarding the role of PET/CT in the initial diagnosis, staging, radiotherapy planning, response monitoring and surveillance of colorectal carcinoma is presented. Future directions and economic aspects are discussed. Computed tomography (CT), magnetic resonance imaging (MRI) and FDG-PET for colorectal cancer and endorectal ultrasound for rectal cancer. Combined FDG-PET/CT. While other imaging modalities allow superior visualization of the extent and invasion depth of the primary tumor, PET/CT is most sensitive for the detection of distant metastases of colorectal cancer. We recommend a targeted use of PET/CT in cases of unclear M staging, prior to metastasectomy and in suspected cases of residual or recurrent colorectal carcinoma with equivocal conventional imaging. The role of PET/CT in radiotherapy planning and response monitoring needs to be determined. Currently there is no evidence to support the routine use of PET/CT for colorectal screening, staging or surveillance. To optimally exploit the synergy between morphologic and functional information, FDG-PET should generally be performed as an integrated FDG-PET/CT with a contrast-enhanced CT component in colorectal carcinoma. (orig.) [de

  9. Pet Health

    Science.gov (United States)

    ... companionship and a feeling of safety to your life. Before getting a pet, think carefully about which ... Gaining or losing a lot of weight quickly Strange behavior Being sluggish and tired Trouble getting up ...

  10. 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

  11. Development of nuclear imaging instrument and software

    International Nuclear Information System (INIS)

    Kim, Jang Hee; Chung Jae Myung; Nam, Sang Won; Chang, Hyung Uk

    1999-03-01

    In the medical diagnosis, the nuclear medical instrument using the radioactive isotope are commonly utilized. In the foreign countries, the medical application and development of the most advanced nuclear medical instrument such as Single Photon Emission Computer Tomography (SPECT) and position emission tomograph (PET), have been extensively carried out. However, in Korea, such highly expensive instruments have been all, imported, paying foreign currency. Since 1997, much efforts, the development of the radio nuclide medical instrument, the drive of the domestic production, etc. have been made to establish our own technologies and to balance the international payments under the support of the Ministry of Science and Technology. At present time, 180 nuclear imaging instruments are now in operation and 60 of them are analog camera. In analog camera, the vector X-Y monitor is need for are image display. Since the analog camera, signal can not be process in the digital form, we have difficulties to transfer and store the image data. The image displayed at the monitor must be stored in the form of polaroid or X ray film. In order to discard these disadvantages, if we developed the computer interface system, the performance analog camera will be comparable with that of the digital camera. The final objective of the research is that using the interface system developed in this research, we reconstruct the image data transmitted to the personal computer in the form of the generalized data file

  12. The establishment of the Rossendorf PET Center

    International Nuclear Information System (INIS)

    Johannsen, B.; Steinbach, J.

    1993-01-01

    The objectives of the newly established Positron Emission Tomography (PET) Center at the Institut of Bioinorganic and Radiopharmaceutical Chemistry in Rossendorf are described, referring to medical research, development of tracers and radiochemicals developments, biochemistry and future prospects of PET in Rossendorf. The layout of the center is also described considering the cyclotron and targetry, the transport system, the radiopharmaceutical laboratories and the tomograph. A schedule for project development is going. (BBR)

  13. PET tracer for imaging of neuroendocrine tumors

    DEFF Research Database (Denmark)

    2013-01-01

    There is provided a radiolabelled peptide-based compound for diagnostic imaging using positron emission tomography (PET). The compound may thus be used for diagnosis of malignant diseases. The compound is particularly useful for imaging of somatostatin overexpression in tumors, wherein the compound...... is capable of being imaged by PET when administered with a target dose in the range of 150-350 MBq, such as 150-250 MBq, preferable in the range of 191-210 MBq....

  14. Practical use and implementation of PET in children in a hospital PET centre

    DEFF Research Database (Denmark)

    Borgwardt, Lise; Larsen, Helle Jung; Pedersen, Kate

    2003-01-01

    Children are not just small adults-they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use...... and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments......, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine....

  15. Practical use and implementation of PET in children in a hospital PET centre

    International Nuclear Information System (INIS)

    Borgwardt, Lise; Larsen, Helle Jung; Pedersen, Kate; Hoejgaard, Liselotte

    2003-01-01

    Children are not just small adults - they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine. (orig.)

  16. Practical use and implementation of PET in children in a hospital PET centre

    Energy Technology Data Exchange (ETDEWEB)

    Borgwardt, Lise; Larsen, Helle Jung; Pedersen, Kate; Hoejgaard, Liselotte [Department of Clinical Physiology, Nuclear Medicine and PET, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen (Denmark)

    2003-10-01

    Children are not just small adults - they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine. (orig.)

  17. Pet Allergy Quiz

    Science.gov (United States)

    ... Treatments ▸ Allergies ▸ Pet Allergy ▸ Pet Allergy Quiz Share | Pet Allergy Quiz More than half of U.S. households ... cat family. Yet, millions of people suffer from pet allergies. Take this quiz to test your knowledge ...

  18. Nuclear medicine and oncology. Hopes and challenging issues of drugs development: the usefulness of positron emission tomography (PET). An application to targeted therapy

    International Nuclear Information System (INIS)

    Courbon, F.; Delord, J.P.

    2005-01-01

    Thanks to breakthroughs in drug design, new kinds of treatment in oncology have been developed. These new molecules target usually a precise molecular pathway proved to be involved in the development of a malignant disease. This led to the concept of targeted therapy. Therefore, the accurate selection of patients who may experience a clinical benefit of such treatments, and the way to assess the response are still challenging issues. Molecular imaging with radiolabeled compounds seemed to be a very promising tool, as for example PET with F-18 Fluorodeoxyglucose (FDG) which allows to assess and to predict the response to a tyrosine kinase inhibitors more efficiently than conventional imaging tools. FDG is only a surrogate marker of cell proliferation. New F18 radiolabeled molecules provide more specific information about tumor biology, such as receptor expression, DNA and protein synthesis, rate of hypoxia.... The common tools (clinical and radiological assessment) are no longer sufficient to predict the clinical efficacy of these new drugs. Molecular imaging should be added in the design of clinical trials in order to detect earlier pharmaco-dynamic effects, to select responding patients and to provide proofs of efficacy of these non-cytotoxic compounds. Molecular imaging databases have to be created and cross-matched to tumor sample collections, providing consequently new 'dynamic' pathological resources. This requires that all these new F18 radiolabeled molecules have to be readily available and easy to be implemented in clinical trials. (author)

  19. 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.

  20. Positron emission tomography in brain function study

    International Nuclear Information System (INIS)

    Wu Hua

    2006-01-01

    Little has been recognized about the advanced brain function. Recent years several new techniques such as event-related potentials, megnetoencephalography, functional magnetic resonance imaging and positron emission tomography (PET) have been used in the study of brain function. The methodology, application study in normal people and clinical patients of PET in brain function are reviewed. (authors)

  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. Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

    Energy Technology Data Exchange (ETDEWEB)

    Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh [Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis (United States)

    2016-12-15

    Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[{sup 18}F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases

  4. Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

    International Nuclear Information System (INIS)

    Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh

    2016-01-01

    Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-["1"8F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases, the

  5. PET-NECK: a multicentre randomised Phase III non-inferiority trial comparing a positron emission tomography-computerised tomography-guided watch-and-wait policy with planned neck dissection in the management of locally advanced (N2/N3) nodal metastases in patients with squamous cell head and neck cancer.

    Science.gov (United States)

    Mehanna, Hisham; McConkey, Chris C; Rahman, Joy K; Wong, Wai-Lup; Smith, Alison F; Nutting, Chris; Hartley, Andrew Gj; Hall, Peter; Hulme, Claire; Patel, Dharmesh K; Zeidler, Sandra Ventorin von; Robinson, Max; Sanghera, Bal; Fresco, Lydia; Dunn, Janet A

    2017-04-01

    Planned neck dissection (ND) after radical chemoradiotherapy (CRT) for locally advanced nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) remains controversial. Thirty per cent of ND specimens show histological evidence of tumour. Consequently, a significant proportion of clinicians still practise planned ND. Fludeoxyglucose positron emission tomography (PET)-computerised tomography (CT) scanning demonstrated high negative predictive values for persistent nodal disease, providing a possible alternative paradigm to ND. Evidence is sparse and drawn mainly from retrospective single-institution studies, illustrating the need for a prospective randomised controlled trial. To determine the efficacy and cost-effectiveness of PET-CT-guided surveillance, compared with planned ND, in a multicentre, prospective, randomised setting. A pragmatic randomised non-inferiority trial comparing PET-CT-guided watch-and-wait policy with the current planned ND policy in HNSCC patients with locally advanced nodal metastases and treated with radical CRT. Patients were randomised in a 1 : 1 ratio. Primary outcomes were overall survival (OS) and cost-effectiveness [incremental cost per incremental quality-adjusted life-year (QALY)]. Cost-effectiveness was assessed over the trial period using individual patient data, and over a lifetime horizon using a decision-analytic model. Secondary outcomes were recurrence in the neck, complication rates and quality of life. The recruitment of 560 patients was planned to detect non-inferior OS in the intervention arm with a 90% power and a type I error of 5%, with non-inferiority defined as having a hazard ratio (HR) of no higher than 1.50. An intention-to-treat analysis was performed by Cox's proportional hazards model. Thirty-seven head and neck cancer-treating centres (43 NHS hospitals) throughout the UK. Patients with locally advanced nodal metastases of oropharynx, hypopharynx, larynx, oral or occult HNSCC receiving

  6. Respiratory gating in cardiac PET

    DEFF Research Database (Denmark)

    Lassen, Martin Lyngby; Rasmussen, Thomas; Christensen, Thomas E

    2017-01-01

    BACKGROUND: Respiratory motion due to breathing during cardiac positron emission tomography (PET) results in spatial blurring and erroneous tracer quantification. Respiratory gating might represent a solution by dividing the PET coincidence dataset into smaller respiratory phase subsets. The aim...... of our study was to compare the resulting imaging quality by the use of a time-based respiratory gating system in two groups administered either adenosine or dipyridamole as the pharmacological stress agent. METHODS AND RESULTS: Forty-eight patients were randomized to adenosine or dipyridamole cardiac...... stress (82)RB-PET. Respiratory rates and depths were measured by a respiratory gating system in addition to registering actual respiratory rates. Patients undergoing adenosine stress showed a decrease in measured respiratory rate from initial to later scan phase measurements [12.4 (±5.7) vs 5.6 (±4...

  7. PET Metabolic Biomarkers for Cancer

    Directory of Open Access Journals (Sweden)

    Etienne Croteau

    2016-01-01

    Full Text Available The body's main fuel sources are fats, carbohydrates (glucose, proteins, and ketone bodies. It is well known that an important hallmark of cancer cells is the overconsumption of glucose. Positron emission tomography (PET imaging using the glucose analog 18 F-fluorodeoxyglucose ( 18 F-FDG has been a powerful cancer diagnostic tool for many decades. Apart from surgery, chemotherapy and radiotherapy represent the two main domains for cancer therapy, targeting tumor proliferation, cell division, and DNA replication–-all processes that require a large amount of energy. Currently, in vivo clinical imaging of metabolism is performed almost exclusively using PET radiotracers that assess oxygen consumption and mechanisms of energy substrate consumption. This paper reviews the utility of PET imaging biomarkers for the detection of cancer proliferation, vascularization, metabolism, treatment response, and follow-up after radiation therapy, chemotherapy, and chemotherapy-related side effects.

  8. Effect of ginseng pretreatment on cerebral glucose metabolism in ischaemic rats using animal positron emission tomography (PET) and [18F]-FDG

    Energy Technology Data Exchange (ETDEWEB)

    Rye, Choi Seok; Magata, Y.; Saji, H.; Tajima, K.; Kitano, H.; Konishi, J.; Yokoyama, A. [Department of Radiopharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University, Yoshida Shimoadachi-cho, Sakyo-ku, Kyoto 606-01 (Japan)

    1997-07-01

    To investigate the effect of ginseng on damaged brain activity, we evaluated the cerebral metabolic rate of glucose (CMRglc) as a functional index in post-ischaemic rats and compared the results with those obtained after the administration of a ginseng extract. CMRglc was measured using high resolution animal positron emission tomography with {sup 18}F-2-fluoro-2-deoxy-D-glucose ({sup 18}F-FDG). The rats subjected to a 30-min occlusion showed a significant reduction of k3, the rate constant for phosphorylation of {sup 18}F-FDG by hexokinase, compared with the normal value. The ginseng pretreatment prevented the reduction in k3 and CMRglc caused by ischaemia. Although further investigation is needed to elucidate the mechanism of action, ginseng may be useful for prevention and treatment of ischaemia. © 1997 John Wiley & Sons, Ltd.

  9. PET and PET-CT. State of the art and future prospects

    International Nuclear Information System (INIS)

    Fanti, Stefano; Franchi, Roberto; Battista, Giuseppe; Monetti, Nino; Canini, Romeo

    2005-01-01

    Fluoro-deoxyglucose positron emission tomography (FDG PET) enables the in vivo study of tissue metabolism, and thus is able to identify malignant tumours as hypermetabolic lesions by an increase in tracer uptake. Many papers have demonstrated both the relevant impact of FDG PET on staging of many cancers and the superior accuracy of the technique compared with conventional diagnostic methods for pre-treatment evaluation, therapy response evaluation and relapse identification. In particular PET was found useful in identifying lymph nodal and metastatic spread. thus altering patient management in more than 30% of cases. PET images, however, provide limited anatomical data, which in regions such as the head and neck, mediastinum and pelvic cavity is a significant drawback. The exact localization of lesions may also be difficult in some cases, on the basis of PET images alone. The introduction of combined PET-computed tomography (PET-CT) scanners enables the almost simultaneous acquisition of transmission and emission images, thus obtaining optimal fusion images in a very short time. PET-CT fusion images enable lesions to be located, reducing false positive studies and increasing accuracy; the overall duration of examination may also be reduced. On the basis of both literature data and our experience we established the clinical indications when PET-CT may be particularly useful, in comparison with PET alone. It should also be underlined that the use of PET-CT is almost mandatory for new traces such as C-choline and C-methionine; these new tracers may be applied for studying tumours not assessable with FDG, such as prostate cancer. In conclusion PET-CT is at present the most advanced method for metabolic imaging, and is capable of precisely localizing and assessing tumours; fusion images reduce false positive and inconclusive studies, thus increasing diagnostic accuracy [it

  10. SPECT og PET i neurobiologien

    DEFF Research Database (Denmark)

    Paulson, O.B.; Lassen, N.A.

    1997-01-01

    PET (positron emission tomography) and SPECT (single photon emission computed tomography) are isotopic methods in which the distribution is registered of radiolabelled tracers given in such small amounts that they are without effect on the organism or the organism's disposal of them. Thus, a series...... of important biological processes in the intact organism can be studied. The methods have been used in many disciplines but in particular for neurobiological research on the brain--e.g., the brain's regional blood circulation and mapping of the brain's functional structure. The methods have also been used...

  11. Kinetic modeling in PET imaging of hypoxia

    Science.gov (United States)

    Li, Fan; Joergensen, Jesper T; Hansen, Anders E; Kjaer, Andreas

    2014-01-01

    Tumor hypoxia is associated with increased therapeutic resistance leading to poor treatment outcome. Therefore the ability to detect and quantify intratumoral oxygenation could play an important role in future individual personalized treatment strategies. Positron Emission Tomography (PET) can be used for non-invasive mapping of tissue oxygenation in vivo and several hypoxia specific PET tracers have been developed. Evaluation of PET data in the clinic is commonly based on visual assessment together with semiquantitative measurements e.g. standard uptake value (SUV). However, dynamic PET contains additional valuable information on the temporal changes in tracer distribution. Kinetic modeling can be used to extract relevant pharmacokinetic parameters of tracer behavior in vivo that reflects relevant physiological processes. In this paper, we review the potential contribution of kinetic analysis for PET imaging of hypoxia. PMID:25250200

  12. Diagnostic accuracy of 18F-FDG-PET and PET/CT in patients with Ewing sarcoma family tumours: a systematic review and a meta-analysis

    International Nuclear Information System (INIS)

    Treglia, Giorgio; Salsano, Marco; Stefanelli, Antonella; Mattoli, Maria Vittoria; Giordano, Alessandro; Bonomo, Lorenzo

    2012-01-01

    To systematically review and meta-analyse literature data on the diagnostic performance of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) in patients with Ewing sarcoma family tumours (ESFT). PubMed/MEDLINE, Embase and Scopus databases were searched for articles that evaluated FDG-PET and PET/CT in patients with ESFT from inception to 31 May 2011. Studies that fulfilled the three following criteria were included in the systematic review: FDG-PET or PET/CT performed in patients with ESFT; articles about the diagnostic accuracy of FDG-PET and PET/CT; sample size of at least 10 patients with ESFT were included. Studies in which there were sufficient data to reassess sensitivity and specificity of FDG-PET or PET/CT in ESFT were included in the meta-analysis, excluding duplicate publications. Finally, pooled sensitivity, pooled specificity and area under the receiver operating characteristic (ROC) curve of FDG-PET or PET/CT in ESFT were calculated. We found 13 studies comprising a total of 342 patients with ESFT. The main findings of the studies included are presented. The meta-analysis of five selected studies provided these results about FDG-PET and PET/CT in ESFT: pooled sensitivity: 96% (95% confidence interval [CI] 91-99%); pooled specificity: 92% (95% CI 87-96%); area under the ROC curve: 0.97. With regard to the staging and restaging of patients with ESFT, the sensitivity, specificity and accuracy of FDG-PET and PET/CT are high; the combination of FDG-PET or PET/CT with conventional imaging is a valuable tool for the staging and restaging of ESFT and has a relevant impact on the treatment strategy plan. (orig.)

  13. Diagnostic accuracy of {sup 18}F-FDG-PET and PET/CT in patients with Ewing sarcoma family tumours: a systematic review and a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Treglia, Giorgio [Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Institute of Nuclear Medicine, Positron Emission Tomography Centre, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Salsano, Marco; Stefanelli, Antonella; Mattoli, Maria Vittoria; Giordano, Alessandro [Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Bonomo, Lorenzo [Institute of Radiology, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy)

    2012-03-15

    To systematically review and meta-analyse literature data on the diagnostic performance of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) in patients with Ewing sarcoma family tumours (ESFT). PubMed/MEDLINE, Embase and Scopus databases were searched for articles that evaluated FDG-PET and PET/CT in patients with ESFT from inception to 31 May 2011. Studies that fulfilled the three following criteria were included in the systematic review: FDG-PET or PET/CT performed in patients with ESFT; articles about the diagnostic accuracy of FDG-PET and PET/CT; sample size of at least 10 patients with ESFT were included. Studies in which there were sufficient data to reassess sensitivity and specificity of FDG-PET or PET/CT in ESFT were included in the meta-analysis, excluding duplicate publications. Finally, pooled sensitivity, pooled specificity and area under the receiver operating characteristic (ROC) curve of FDG-PET or PET/CT in ESFT were calculated. We found 13 studies comprising a total of 342 patients with ESFT. The main findings of the studies included are presented. The meta-analysis of five selected studies provided these results about FDG-PET and PET/CT in ESFT: pooled sensitivity: 96% (95% confidence interval [CI] 91-99%); pooled specificity: 92% (95% CI 87-96%); area under the ROC curve: 0.97. With regard to the staging and restaging of patients with ESFT, the sensitivity, specificity and accuracy of FDG-PET and PET/CT are high; the combination of FDG-PET or PET/CT with conventional imaging is a valuable tool for the staging and restaging of ESFT and has a relevant impact on the treatment strategy plan. (orig.)

  14. Diagnosis of non-osseous spinal metastatic disease: the role of PET/CT and PET/MRI.

    Science.gov (United States)

    Batouli, Ali; Braun, John; Singh, Kamal; Gholamrezanezhad, Ali; Casagranda, Bethany U; Alavi, Abass

    2018-06-01

    The spine is the third most common site for distant metastasis in cancer patients with approximately 70% of patients with metastatic cancer having spinal involvement. Positron emission tomography (PET), combined with computed tomography (CT) or magnetic resonance imaging (MRI), has been deeply integrated in modern clinical oncology as a pivotal component of the diagnostic work-up of patients with cancer. PET is able to diagnose several neoplastic processes before any detecta