WorldWideScience

Sample records for emission tomography coupled

  1. Novel Electro-Optical Coupling Technique for Magnetic Resonance-Compatible Positron Emission Tomography Detectors

    Directory of Open Access Journals (Sweden)

    Peter D. Olcott

    2009-03-01

    Full Text Available A new magnetic resonance imaging (MRI-compatible positron emission tomography (PET detector design is being developed that uses electro-optical coupling to bring the amplitude and arrival time information of high-speed PET detector scintillation pulses out of an MRI system. The electro-optical coupling technology consists of a magnetically insensitive photodetector output signal connected to a nonmagnetic vertical cavity surface emitting laser (VCSEL diode that is coupled to a multimode optical fiber. This scheme essentially acts as an optical wire with no influence on the MRI system. To test the feasibility of this approach, a lutetium-yttrium oxyorthosilicate crystal coupled to a single pixel of a solid-state photomultiplier array was placed in coincidence with a lutetium oxyorthosilicate crystal coupled to a fast photomultiplier tube with both the new nonmagnetic VCSEL coupling and the standard coaxial cable signal transmission scheme. No significant change was observed in 511 keV photopeak energy resolution and coincidence time resolution. This electro-optical coupling technology enables an MRI-compatible PET block detector to have a reduced electromagnetic footprint compared with the signal transmission schemes deployed in the current MRI/PET designs.

  2. Novel electro-optical coupling technique for magnetic resonance-compatible positron emission tomography detectors.

    Science.gov (United States)

    Olcott, Peter D; Peng, Hao; Levin, Craig S

    2009-01-01

    A new magnetic resonance imaging (MRI)-compatible positron emission tomography (PET) detector design is being developed that uses electro-optical coupling to bring the amplitude and arrival time information of high-speed PET detector scintillation pulses out of an MRI system. The electro-optical coupling technology consists of a magnetically insensitive photodetector output signal connected to a nonmagnetic vertical cavity surface emitting laser (VCSEL) diode that is coupled to a multimode optical fiber. This scheme essentially acts as an optical wire with no influence on the MRI system. To test the feasibility of this approach, a lutetium-yttrium oxyorthosilicate crystal coupled to a single pixel of a solid-state photomultiplier array was placed in coincidence with a lutetium oxyorthosilicate crystal coupled to a fast photomultiplier tube with both the new nonmagnetic VCSEL coupling and the standard coaxial cable signal transmission scheme. No significant change was observed in 511 keV photopeak energy resolution and coincidence time resolution. This electro-optical coupling technology enables an MRI-compatible PET block detector to have a reduced electromagnetic footprint compared with the signal transmission schemes deployed in the current MRI/PET designs.

  3. 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)

  4. 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

  5. Single photon emission tomography

    International Nuclear Information System (INIS)

    Buvat, Irene

    2011-09-01

    The objective of this lecture is to present the single photon emission computed tomography (SPECT) imaging technique. Content: 1 - Introduction: anatomic, functional and molecular imaging; Principle and role of functional or molecular imaging; 2 - Radiotracers: chemical and physical constraints, main emitters, radioisotopes production, emitters type and imaging techniques; 3 - Single photon emission computed tomography: gamma cameras and their components, gamma camera specifications, planar single photon imaging characteristics, gamma camera and tomography; 4 - Quantification in single photon emission tomography: attenuation, scattering, un-stationary spatial resolution, partial volume effect, movements, others; 5 - Synthesis and conclusion

  6. 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

  7. Cardiac positron emission tomography

    International Nuclear Information System (INIS)

    Eftekhari, M.; Ejmalian, G.

    2003-01-01

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

  8. Positron emission tomography

    International Nuclear Information System (INIS)

    Iio, Masahiro

    1982-01-01

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

  9. Emission computed tomography

    International Nuclear Information System (INIS)

    Budinger, T.F.; Gullberg, G.T.; Huesman, R.H.

    1979-01-01

    This chapter is devoted to the methods of computer assisted tomography for determination of the three-dimensional distribution of gamma-emitting radionuclides in the human body. The major applications of emission computed tomography are in biological research and medical diagnostic procedures. The objectives of these procedures are to make quantitative measurements of in vivo biochemical and hemodynamic functions

  10. 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.)

  11. Positron emission tomography

    International Nuclear Information System (INIS)

    Wienhard, K.; Heiss, W.D.

    1984-01-01

    The principles and selected clinical applications of positron emission tomography are described. In this technique a chemical compound is labeled with a positron emitting isotope and its biochemical pathway is traced by coincidence detection of the two annihilation photons. The application of the techniques of computed tomography allows to reconstruct the spatial distribution of the radioactivity within a subject. The 18 F-deoxyglucose method for quantitative measurement of local glucose metabolism is discussed in order to illustrate the possibilities of positron emission tomography to record physiological processes in vivo. (orig.) [de

  12. Use of a YAP:Ce matrix coupled to a position-sensitive photomultiplier for high resolution positron emission tomography

    International Nuclear Information System (INIS)

    Del Guerra, A.; Zavattini, G.; Notaristefani, F. de; Giganti, M.; Piffanelli, A.; Pani, R.; Turra, A.

    1996-01-01

    A new scintillation detector system has been designed for application in high resolution Positron Emission Tomography (PET). The detector is a bundle of small YAlO 3 :Ce (YAP) crystals closely packed (0.2 x 0.2 x 3.0 cm 3 ), coupled to a position sensitive photomultiplier tube (PSPMT). The preliminary results obtained for spatial resolution, time resolution, energy resolution and efficiency of two such detectors working in coincidence are presented. These are 1.2 mm for the FWHM spatial resolution, 2.0 ns for the FWHM time resolution and 20% for the FWHM energy resolution at 511 keV. The measured efficiency is (44 ± 3)% with a 150 keV threshold and (20 ± 2)% with a 300 keV threshold

  13. 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)

  14. Lower maximum standardized uptake value of fluorine-18 fluorodeoxyglucose positron emission tomography coupled with computed tomography imaging in pancreatic ductal adenocarcinoma patients with diabetes.

    Science.gov (United States)

    Chung, Kwang Hyun; Park, Joo Kyung; Lee, Sang Hyub; Hwang, Dae Wook; Cho, Jai Young; Yoon, Yoo-Seok; Han, Ho-Seong; Hwang, Jin-Hyeok

    2015-04-01

    The effects of diabetes mellitus (DM) on sensitivity of fluorine-18 fluorodeoxyglucose positron emission tomography coupled with computed tomography ((18)F-FDG PET/CT) for diagnosing pancreatic ductal adenocarcinomas (PDACs) is not well known. This study was aimed to evaluate the effects of DM on the validity of (18)F-FDG PET/CT in PDAC. A total of 173 patients with PDACs who underwent (18)F-FDG PET/CT were enrolled (75 in the DM group and 98 in the non-DM group). The maximum standardized uptake values (SUVsmax) were compared. The mean SUVmax was significantly lower in the DM group than in the non-DM group (4.403 vs 5.998, P = .001). The sensitivity of SUVmax (cut-off value 4.0) was significantly lower in the DM group than in the non-DM group (49.3% vs 75.5%, P < .001) and also lower in normoglycemic DM patients (n = 24) than in non-DM patients (54.2% vs 75.5%, P = .038). DM contributes to a lower SUVmax of (18)F-FDG PET/CT in patients with PDACs. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. 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)

  16. 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

  17. 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)

  18. 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

  19. Positron emission tomography

    International Nuclear Information System (INIS)

    Paans, A.M.J.

    1981-01-01

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

  20. Tomography by positrons emission

    International Nuclear Information System (INIS)

    Mosconi, Sergio L.

    1999-01-01

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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.).

  6. 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.)

  7. Emission computed tomography

    International Nuclear Information System (INIS)

    Phelps, M.E.

    1977-01-01

    Although there are many common aspects to x-ray transmission and radionuclide emission (ECT) computerized tomography, there are added difficulties and a number of particular factors which form the basis of ECT. The relationship between the physical factors, system design, methodologic approach and assumptions of ECT is discussed. The instrumentation design and application strategies in ECT at this time are diverse and in a rapid stage of development. The approaches are divided into two major categories of Single Photon Counting (SPC) employing scanner and camera concepts with radionuclides of 99 /sup m/Tc, 201 Tl, 123 I etc., and Annihilation Coincidence Detection (ACD) of positron-emitting radionuclides. Six systems in the former and ten systems in the latter category, with examples of typical studies, illustrate the different approaches

  8. Positron emission computed tomography

    International Nuclear Information System (INIS)

    Grover, M.; Schelbert, H.R.

    1985-01-01

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

  9. Positron emission tomography camera

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

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

  10. Positron emission tomography camera

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

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

  11. Positron emission tomography camera

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    A positron emission tomography camera having a plurality of detector rings positioned side-by-side or offset by one-half of the detector cross section around a patient area to detect radiation therefrom. Each detector ring or offset ring includes a plurality of photomultiplier tubes and a plurality of scintillation crystals are positioned relative to the photomultiplier tubes whereby each tube is responsive to more than one crystal. Each alternate crystal in the ring is offset by one-half or less of the thickness of the crystal such that the staggered crystals are seen by more than one photomultiplier tube. This sharing of crystals and photomultiplier tubes allows identification of the staggered crystal and the use of smaller detectors shared by larger photomultiplier tubes thereby requiring less photomultiplier tubes, creating more scanning slices, providing better data sampling, and reducing the cost of the camera. The offset detector ring geometry reduces the costs of the positron camera and improves its performance

  12. 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.

  13. Positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lindback, Stig [GEMS PET Systems AB, Uppsala (Sweden)

    1995-07-15

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

  14. Positron emission tomography

    International Nuclear Information System (INIS)

    Lindback, Stig

    1995-01-01

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

  15. Respiratory-Gated Positron Emission Tomography and Breath-Hold Computed Tomography Coupling to Reduce the Influence of Respiratory Motion: Methodology and Feasibility

    International Nuclear Information System (INIS)

    Daouk, J.; Fin, L.; Bailly, P.; Meyer, M.E.

    2009-01-01

    Background: Respiratory motion causes uptake in positron emission tomography (PET) images of chest and abdominal structures to be blurred and reduced in intensity. Purpose: To compare two respiratory-gated PET binning methods (based on frequency and amplitude analyses of the respiratory signal) and to propose a 'BH-based' method based on an additional breath-hold computed tomography (CT) acquisition. Material and Methods: Respiratory-gated PET consists in list-mode (LM) acquisition with simultaneous respiratory signal recording. A phantom study featured rectilinear movement of a 0.5-ml sphere filled with 18 F-fluorodeoxyglucose ( 18 F-FDG) solution, placed in a radioactive background (sphere-to-background contrast 6:1). Two patients were also examined. Three figures of merit were calculated: the target-to-background ratio profile (TBRP) in the axial direction through the uptake (i.e., the sphere or lesion), full-width-at-half-maximum (FWHM) values, and maximized standard uptake values (SUVmax). Results: In the phantom study, the peak TBRP was 0.9 for non-gated volume, 1.83 for BH-based volume, and varied between 1.13 and 1.73 for Freq-based volumes and between 1.34 and 1.66 for Amp-based volumes. A reference volume (REF-static) was also acquired for the phantom (in a static, 'expiratory' state), with a peak TBRP at 1.88. TBRPs were computed for patient data, with higher peak values for all gated volumes than for non-gated volumes. Conclusion: Respiratory-gated PET acquisition reduces the blurring effect and increases image contrast. However, Freq-based and Amp-based volumes are still influenced by inappropriate attenuation correction and misregistration of mobile lesions on CT images. The proposed BH-based method both reduces motion artifacts and improves PET-CT registration

  16. Positron emission tomography in oncology

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

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

  17. NMF on positron emission tomography

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  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. Emission tomography system

    International Nuclear Information System (INIS)

    Phelps, M.E.; Hoffman, E.J.; Williams, C.W.; Burgiss, S.G.

    1983-01-01

    In the present invention a positron emission tomographic system is provided in which the random photon coincidence background is determined for the lines of sight along which the positron annihiliations are located. The circuitry is arranged so that this background may be subtracted almost simultaneously from the total photon coincidence measurement, or may be stored in a temporary memory for latter subtraction. In this system, an appropriate coincidence resolution time is selected and coincidences of photons detected at 180 degree opposed detectors within the time resolution are recorded as the overall coincidence count. This total count includes a source(true events) count plus a background(random coincidences) count. The background count is determined by measuring photons detected at these same sets of photon detectors and employing the same coincidence resolution period, where the signals from one set of detectors are passed through a delay longer in time than this resolution period

  20. Positron emission tomography. Basic principles

    International Nuclear Information System (INIS)

    Rodriguez, Jose Luis; Massardo, Teresa; Gonzalez, Patricio

    2001-01-01

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

  1. Single photon emission computerized tomography

    International Nuclear Information System (INIS)

    Hooge, P. de.

    1983-01-01

    In this thesis two single-photon emission tomographic techniques are presented: (a) longitudinal tomography with a rotating slanting-hole collimator, and (b) transversal tomography with a rotating gamma camera. These methods overcome the disadvantages of conventional scintigraphy. Both detection systems and the image construction methods are explained and comparisons with conventional scintigraphy are drawn. One chapter is dedicated to the determination of system parameters like spatial resolution, contrast, detector uniformity, and size of the object, by phantom studies. In separate chapters the results are presented of detection of tumors and metastases in the liver and the liver hilus; skeletal diseases; various pathological aberrations of the brain; and myocardial perfusion. The possible use of these two ect's for other organs and body areas is discussed in the last chapter. (Auth.)

  2. Positron emission tomography takes lead

    International Nuclear Information System (INIS)

    Simms, R.

    1989-01-01

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

  3. Fundamentals of positron emission tomography

    International Nuclear Information System (INIS)

    Ostertag, H.

    1989-01-01

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

  4. Emission tomography for adrenal imaging

    International Nuclear Information System (INIS)

    Britton, K.E.; Shapiro, B.; Hawkins, L.A.

    1980-01-01

    Single photon emission tomography (SPET) of the adrenals was compared to convential gamma camera images. Depths of 19 adrenals were assessed by both the lateral skin-upper kidney pole method and by SPET. Eleven patients with adrenal disorders were also studied. An advantage of using SPET was that the analogue transverse section image showed improvement over the conventional posterior view because the liver activity was well separated from the adrenal. Furthermore, non-adrenal tissue background was virtually eliminated and adrenal depth determination facilitated. (U.K.)

  5. Single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Budinger, T.F.

    1986-01-01

    Single photon tomography dates from the early 1960's when the idea of emission transverse section tomography was presented by Kuhl and Edwards. They used a rectilinear scanner and analogue back-projection methods to detect emissions from a series of sequential positions transverse to the cephaldcaudad axis of the body. This chapter presents an explanation of emission tomography by describing longitudinal and transverse section tomography. In principle all modes of tomography can be considered under the general topic of coded apertures wherein the code ranges from translation of a pinhole collimator to rotation of a parallel hole or focused collimator array

  6. 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

  7. Improved positron emission tomography camera

    International Nuclear Information System (INIS)

    Mullani, N.A.

    1986-01-01

    A positron emission tomography camera having a plurality of rings of detectors positioned side-by-side or offset by one-half of the detector cross section around a patient area to detect radiation therefrom, and a plurality of scintillation crystals positioned relative to the photomultiplier tubes whereby each tube is responsive to more than one crystal. Each alternate crystal in the ring may be offset by one-half or less of the thickness of the crystal such that the staggered crystals are seen by more than one photomultiplier tube. This sharing of crystals and photomultiplier tubes allows identification of the staggered crystal and the use of smaller detectors shared by larger photomultiplier tubes thereby requiring less photomultiplier tubes, creating more scanning slices, providing better data sampling, and reducing the cost of the camera. (author)

  8. Positron emission tomography and migraine

    International Nuclear Information System (INIS)

    Chabriat, H.

    1992-01-01

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

  9. 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...

  10. An introduction to emission computed tomography

    International Nuclear Information System (INIS)

    Williams, E.D.

    1985-01-01

    This report includes salient features of the theory and an examination of practical considerations for someone who is using or introducing tomography, selecting equipment for it or wishing to develop a clinical application. Emphasis is on gamma camera tomography. The subject is dealt with under the following headings: emission computed and gamma camera tomography and the relationship to other medical imaging techniques, the tomographic reconstruction technique theory, rotating gamma camera tomography, attenuation correction and quantitative reconstruction, other single photon tomographic techniques, positron tomography, image display, clinical application of single photon and positron tomography, and commercial systems for SPECT. Substantial bibliography. (U.K.)

  11. Positron emission tomography with Positome, 2

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  12. Positron emission tomography in oncology

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  13. Positron emission tomography in neuropsychology.

    Science.gov (United States)

    Heiss, W D; Herholz, K; Pawlik, G; Wagner, R; Wienhard, K

    1986-01-01

    By positron emission tomography (PET) of 18F-2-fluoro-2-deoxy-D-glucose (FDG) local cerebral metabolic rate for glucose (LCMRGl) can be measured in man. Normal values in cerebral cortex and basal ganglia range from 35 to 50 mumol/100 g/min, the values in gray matter structures of the posterior fossa were 25-30 mumol/100 g/min, the lowest LCMRGl was found in the white matter (15-20 mumol/100 g/min). During sensory stimulation by various modalities functional activation increases LCMRGl in the respective special areas, while sleep decreases metabolic rate in all cortical and basal gray matter structures. In many neurological disorders CMRGl is altered in a disease-specific pattern. In dementia of the Alzheimer type CMRGl is impaired even in early stages with accentuation in the parieto-temporal cortex, while in multi-infarct dementia glucose uptake is mainly reduced in the multifocal small infarcts. In Huntington's chorea the most conspicuous changes are found in the caudate nucleus and putamen. In cases of focal lesions (e.g. ischemic infarcts) metabolic disturbances extend far beyond the site of the primary lesion and inactivation of metabolism is found in intact brain structures far away from the anatomical lesion. Additional applications of PET include determination of the metabolism of various substrates, of protein synthesis, of function and distribution of receptors, of tumor growth and of the distribution of drugs as well as the measurement of oxygen consumption, blood flow and blood volume.

  14. Positron emission tomography in epilepsy

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  15. 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

  16. Development of emission computed tomography in Japan

    International Nuclear Information System (INIS)

    Tanaka, E.

    1984-01-01

    Two positron emission computed tomography (PCT) devices developed in Japan are described. One is for head and the other for wholebody. The devices show fairly quantitative images with slight modifications of the existing algorithms because they were developed based on filtered back-projection. The PCT device seems to be better than the single photon emission computed tomography (SPECT) since it provides adequade compensation for photon attenuation in patients. (M.A.C.) [pt

  17. Dynamic emission tomography of regional cerebral blood flow

    International Nuclear Information System (INIS)

    Lassen, N.A.

    1984-01-01

    The author reviews three tomographic methods for measuring the regional cerebral blood flow: single photon transmission tomography; dual photon emission tomography; and single photon emission tomography. The latter technique is discussed in detail. (Auth.)

  18. Scintillators for positron emission tomography

    International Nuclear Information System (INIS)

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

    1995-09-01

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

  19. Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Disseminated Cryptococcosis.

    Science.gov (United States)

    Tripathy, Sarthak; Parida, Girish Kumar; Roy, Shambo Guha; Singhal, Abhinav; Mallick, Saumya Ranjan; Tripathi, Madhavi; Shamim, Shamim Ahmed

    2017-01-01

    Disseminated cryptococcosis without pulmonary involvement is a very rare phenomenon. Patterns of organ involvement in cryptococcosis resemble various other infective conditions as well as malignant conditions on fluorodeoxyglucose positron emission tomography-computed tomography. We present a case of a 43-year-old male patient who had disseminated cryptococcosis. The rarity of the case being noninvolvement of lungs and meninges and resembling more like lymphoma due to the diffuse involvement of the lymph nodes on both sides of the diaphragm.

  20. 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. ...

  1. Data analysis in emission tomography using emission-count posteriors

    International Nuclear Information System (INIS)

    Sitek, Arkadiusz

    2012-01-01

    A novel approach to the analysis of emission tomography data using the posterior probability of the number of emissions per voxel (emission count) conditioned on acquired tomographic data is explored. The posterior is derived from the prior and the Poisson likelihood of the emission-count data by marginalizing voxel activities. Based on emission-count posteriors, examples of Bayesian analysis including estimation and classification tasks in emission tomography are provided. The application of the method to computer simulations of 2D tomography is demonstrated. In particular, the minimum-mean-square-error point estimator of the emission count is demonstrated. The process of finding this estimator can be considered as a tomographic image reconstruction technique since the estimates of the number of emissions per voxel divided by voxel sensitivities and acquisition time are the estimates of the voxel activities. As an example of a classification task, a hypothesis stating that some region of interest (ROI) emitted at least or at most r-times the number of events in some other ROI is tested. The ROIs are specified by the user. The analysis described in this work provides new quantitative statistical measures that can be used in decision making in diagnostic imaging using emission tomography. (paper)

  2. Data analysis in emission tomography using emission-count posteriors

    Science.gov (United States)

    Sitek, Arkadiusz

    2012-11-01

    A novel approach to the analysis of emission tomography data using the posterior probability of the number of emissions per voxel (emission count) conditioned on acquired tomographic data is explored. The posterior is derived from the prior and the Poisson likelihood of the emission-count data by marginalizing voxel activities. Based on emission-count posteriors, examples of Bayesian analysis including estimation and classification tasks in emission tomography are provided. The application of the method to computer simulations of 2D tomography is demonstrated. In particular, the minimum-mean-square-error point estimator of the emission count is demonstrated. The process of finding this estimator can be considered as a tomographic image reconstruction technique since the estimates of the number of emissions per voxel divided by voxel sensitivities and acquisition time are the estimates of the voxel activities. As an example of a classification task, a hypothesis stating that some region of interest (ROI) emitted at least or at most r-times the number of events in some other ROI is tested. The ROIs are specified by the user. The analysis described in this work provides new quantitative statistical measures that can be used in decision making in diagnostic imaging using emission tomography.

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

    African Journals Online (AJOL)

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

  4. Measuring techniques in emission computed tomography

    International Nuclear Information System (INIS)

    Jordan, K.; Knoop, B.

    1988-01-01

    The chapter reviews the historical development of the emission computed tomography and its basic principles, proceeds to SPECT and PET, special techniques of emission tomography, and concludes with a comprehensive discussion of the mathematical fundamentals of the reconstruction and the quantitative activity determination in vivo, dealing with radon transformation and the projection slice theorem, methods of image reconstruction such as analytical and algebraic methods, limiting conditions in real systems such as limited number of measured data, noise enhancement, absorption, stray radiation, and random coincidence. (orig./HP) With 111 figs., 6 tabs [de

  5. Positron emission tomography studies of brain receptors

    International Nuclear Information System (INIS)

    Maziere, B.; Maziere, M.

    1991-01-01

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

  6. 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

  7. 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)

  8. 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

  9. 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

  10. 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

  11. 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.

  12. Positron emission tomography applied to fluidization engineering

    NARCIS (Netherlands)

    Dechsiri, C; Ghione, A; van de Wiel, F; Dehling, HG; Paans, AMJ; Hoffmann, AC

    The movement of particles in a laboratory fluidized bed has been studied using Positron Emission Tomography (PET). With this non-invasive technique both pulses of various shapes and single tracer particles were followed in 3-D. The equipment and materials used made it possible to label actual bed

  13. 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

  14. Cardiac blood pool emission tomography

    International Nuclear Information System (INIS)

    Itti, R.; Philippe, L.; Lorgeron, J.M.; Charbonnier, B.; Raynaud, P.; Brochier, M.

    1983-01-01

    After blood pool labeling using technetium-99m, a series of cardiac pictures is acquired during the rotation of a gamma-camera about the patient. Computer processing leads to reconstruction of various tomographic slices from the original planar projection. Electrocardiographic gating selects the different phases of the cardiac cycle. Individual slices through the left ventricular region are added in order to provide ''thick'' slices on which global and regional parameters of the left ventricular function can be determined. Due to the proportionality existing between count rates and labeled blood volumes, any geometrical model can be avoided. The delineation of regions of interest for count integration is made easier due to the absence of superimposition of structures; no correction for background is necessary. Tomography thus appears to be more consistent and more accurate than the classical methods using planar projections. In addition, right ventricular morphological and kinetic studies can be performed in the same conditions as for the left ventricle [fr

  15. 21 CFR 892.1200 - Emission computed tomography system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Emission computed tomography system. 892.1200... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1200 Emission computed tomography system. (a) Identification. An emission computed tomography system is a device intended to detect the...

  16. Positron emission tomography - a new approach to brain chemistry

    International Nuclear Information System (INIS)

    Jacobson, H.G.

    1988-01-01

    Positron emission tomography permits examination of the chemistry of the brain in living beings. Until recently, positron emission tomography had been considered a research tool, but it is rapidly moving into clinical practice. This report describes the uses and applications of positron emission tomography in examinations of patients with strokes, epilepsy, malignancies, dementias, and schizophrenia and in basic studies of synaptic neurotransmission

  17. Shielding design for positron emission tomography facility

    International Nuclear Information System (INIS)

    Abdallah, I.I.

    2007-01-01

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

  18. Emission computed tomography: methodology and applications

    International Nuclear Information System (INIS)

    Reivich, M.; Alavi, A.; Greenberg, J.; Fowler, J.; Christman, D.; Rosenquist, A.; Rintelmann, W.; Hand, P.; MacGregor, R.; Wolf, A.

    1980-01-01

    A technique for the determination of local cerebral glucose metabolism using positron emission computed tomography is described as an example of the development of use of this methodology for the study of these parameters in man. The method for the determination of local cerebral glucose metabolism utilizes 18 F-2-fluoro-2-deoxyglucose ([ 18 F]-FDG). In this method [ 18 F]-FDG is used as a tracer for the exchange of glucose between plasma and brain and its phosphorylation by hexokinase in the tissue. The labelled product of metabolism, [ 18 F]-FDG phosphate, is essentially trapped in the tissue over the time course of the measurement. The studies demonstrate the potential usefulness of emission computed tomography for the measurement of various biochemical and physiological parameters in man. (Auth.)

  19. Positron emission tomography tracers for imaging angiogenesis

    International Nuclear Information System (INIS)

    Haubner, Roland; Beer, Ambros J.; Wang, Hui; Chen, Xiaoyuan

    2010-01-01

    Position emission tomography imaging of angiogenesis may provide non-invasive insights into the corresponding molecular processes and may be applied for individualized treatment planning of antiangiogenic therapies. At the moment, most strategies are focusing on the development of radiolabelled proteins and antibody formats targeting VEGF and its receptor or the ED-B domain of a fibronectin isoform as well as radiolabelled matrix metalloproteinase inhibitors or α v β 3 integrin antagonists. Great efforts are being made to develop suitable tracers for different target structures. All of the major strategies focusing on the development of radiolabelled compounds for use with positron emission tomography are summarized in this review. However, because the most intensive work is concentrated on the development of radiolabelled RGD peptides for imaging α v β 3 expression, which has successfully made its way from bench to bedside, these developments are especially emphasized. (orig.)

  20. A wavelet phase filter for emission tomography

    International Nuclear Information System (INIS)

    Olsen, E.T.; Lin, B.

    1995-01-01

    The presence of a high level of noise is a characteristic in some tomographic imaging techniques such as positron emission tomography (PET). Wavelet methods can smooth out noise while preserving significant features of images. Mallat et al. proposed a wavelet based denoising scheme exploiting wavelet modulus maxima, but the scheme is sensitive to noise. In this study, the authors explore the properties of wavelet phase, with a focus on reconstruction of emission tomography images. Specifically, they show that the wavelet phase of regular Poisson noise under a Haar-type wavelet transform converges in distribution to a random variable uniformly distributed on [0, 2π). They then propose three wavelet-phase-based denoising schemes which exploit this property: edge tracking, local phase variance thresholding, and scale phase variation thresholding. Some numerical results are also presented. The numerical experiments indicate that wavelet phase techniques show promise for wavelet based denoising methods

  1. Longitudinal emission tomography of thyroid and heart

    International Nuclear Information System (INIS)

    Giessen, J.W. van.

    1986-01-01

    In this thesis three devices are discussed for longitudinal emission tomography, one of which has been developed for myocardial imaging and the other two for thyroid imaging. Longitudinal emission tomography is a technique which enables three-dimensional reconstruction of the radioactivity distribution within an organ from two-dimensional distributions on a detector surface. In Ch. 1 a general survey is given of the clinical environment in which the devices will be used. Ch. 2 discusses a well-known technique for myocardial imaging: seven-pinhole tomography. In Ch. 3 this technique is applied to imaging of the thyroid. Three different reconstruction methods have been applied to the data collected with the system (from phantoms as well as from patients) and the results have been evaluated. Ch. 4 discusses simulation studies which were carried out in order to investigate the potentialities of a time-coded aperture (TCA) system designed for thyroid tomography. In Ch. 5 a prototype is tested of the time coded aperture in a clinical environment. The last chapter presents a comparison between the (thyroid) 7P collimator and the TCA device. (Auth.)

  2. Positron emission tomography in epilepsy

    International Nuclear Information System (INIS)

    Gur, R.C.; Gur, R.E.; Sussman, N.M.; Selzer, M.E.

    1985-01-01

    Epilepsy is characterized by paroxysmal alterations in behavior and psychological functions, associated with increased neural discharge that is detectable by EEG. In between these paroxysmal events patients may appear superficially normal, but may have neurological signs and neurpsychological deficits. The neurological signs are sometimes correlated with radiologically detectable lesions, but there is little correlation between the CT abnormalities and the EEG focus, and CT abnormalities are rarely found in ''primary'' or ''idiopathic'' forms of epilepsy. Thus, seizure foci documented by ictal EEG can occur in regions that appear normal on CT. Since brain abnormalities implicated in epilepsy are more clearly reflected in measures of neural activity than in measures of anatomy, PET has particular potential for the study of epileptic pathophysiology. It provides the ability to measure local alterations in brain blood flow and metabolism, which are highly coupled with neural activity, and this makes possible the characterization of metabolic changes associated with epilepsy. Thus PET has the potential for contributing to the localization of epileptic activity as well as to the understanding of its pathophysiology

  3. Positron emission tomography in movement disorders

    International Nuclear Information System (INIS)

    Martin, W.R.W.

    1985-01-01

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

  4. Positron emission tomography in movement disorders

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W R.W.

    1985-02-01

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

  5. 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

  6. Single photon emission computerized tomography (SPECT)

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as 123 I and 99 Tc m that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

  7. Single photon emission computerized tomography (SPECT)

    Energy Technology Data Exchange (ETDEWEB)

    Ganatra, R D

    1993-12-31

    Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as {sup 123}I and {sup 99}Tc{sup m} that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

  8. 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

  9. Development of novel emission tomography system

    Science.gov (United States)

    Fu, Geng

    In recent years, small animals, such as mice and rats, have been widely used as subjects of study in biomedical research while molecular biology and imaging techniques open new opportunities to investigate disease model. With the help of medical imaging techniques, researchers can investigate underlying mechanisms inside the small animal, which are useful for both early diagnosis and treatment monitoring. Based on tracer principle single photon emission computed tomography (SPECT) has increased popularity in small animal imaging due to its higher spatial resolution and variety of single-photon emitting radionuclides. Since the image quality strongly depends on the detector properties, both scintillation and semiconductor detectors are under active investigation for high resolution X-ray and gamma ray photon detection. The desired detector properties include high intrinsic spatial resolution, high energy resolution, and high detection efficiency. In this thesis study, we have made extensive efforts to develop novel emission tomography system, and evaluate the use of both semiconductor and ultra-high resolution scintillation detectors for small animal imaging. This thesis work includes the following three areas. Firstly, we have developed a novel energy-resolved photon counting (ERPC) detector. With the benefits of high energy resolution, high spatial resolution, flexible detection area, and a wide dynamic range of 27--200keV, ERPC detector is well-suited for small animal SPECT applications. For prototype ERPC detector excellent imaging (˜350microm) and spectroscopic performance (4keV Co-57 122keV) has been demonstrated in preliminary study. Secondly, to further improve spatial resolution to hundred-micron level, an ultra-high resolution Intensified EMCCD (I-EMCCD) detector has been designed and evaluated. This detector consists of the newly developed electron multiplying CCD (EMCCD) sensor, columnar CsI(Tl) scintillator, and an electrostatic de-magnifier (DM) tube

  10. 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.

  11. 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

  12. Features and applications of positron emission tomography

    International Nuclear Information System (INIS)

    Fan Mingwu

    1997-01-01

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

  13. Contribution of positron emission tomography in neurology

    International Nuclear Information System (INIS)

    Salmon, E.; Franck, G.

    1992-01-01

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

  14. Electrocardiographic gating in positron emission computed tomography

    International Nuclear Information System (INIS)

    Hoffman, E.J.; Phelps, M.E.; Wisenberg, G.; Schelbert, H.R.; Kuhl, D.E.

    1979-01-01

    Electrocardiographic (ECG) synchronized multiple gated data acquisition was employed with positron emission computed tomography (ECT) to obtain images of myocardial blood pool and myocardium. The feasibility and requirements of multiple gated data acquisition in positron ECT were investigated for 13NH3, ( 18 F)-2-fluoro-2-D-deoxyglucose, and ( 11 C)-carboxyhemoglobin. Examples are shown in which image detail is enhanced and image interpretation is facilitated when ECG gating is employed in the data collection. Analysis of count rate data from a series of volunteers indicates that multiple, statistically adequate images can be obtained under a multiple gated data collection format without an increase in administered dose

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

    Science.gov (United States)

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

    2014-03-01

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

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

    Science.gov (United States)

    Segall, George M

    2010-12-01

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

  17. Cardiological applications of positron emission tomography

    International Nuclear Information System (INIS)

    Schelbert, H.; Czernin, J.

    1994-01-01

    Positron emission tomography (PET) expands the diagnostic possibilities of nuclear medicine techniques for the diagnosis of coronary artery disease and, especially, for the identification of myocardial viability. The presence of coronary artery disease can be detected by evaluation of myocardial blood flow at rest and during pharmacologically induced hyperemia with a sensitivity of 84 to 98% and a specificity of 78 to 100% according to recent studies. Comparative investigations in the same patients have demonstrated a significant gain in the diagnostic accuracy of PET as compared with single photon emission computed tomography (SPECT). PET has influenced even more profoundly the identification of myocardial viability. Measured against the functional outcome of regional contractile function after successful revascularization, an increase of glucose utilization relative to regional myocardial blood flow is 77 to 85% accurate in identifying reversibly injured myocardium. Conversely, PET is 78 to 92% accurate in identifying myocardium as irreversibly injured when pre-operative glucose uptake was reduced or absent. Recent studies have indicated that it is possible to predict to some extent post-revascularization improvement in left ventricular function as well as in congestive heart failure related symptoms in patients with ischemic cardiomyopathy. Furthermore, PET can identify patients with an increased risk of mortality and morbidity as a result of ischemic heart disease and, thus, stratify patients to the most appropriate and cost-effective therapeutic approach. (authors)

  18. Positron emission tomography of the lung

    International Nuclear Information System (INIS)

    Wollmer, P.

    1984-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Joerg, L.; Langsteger, W.

    2002-01-01

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

  1. Single-photon emission tomography and cerebral blood flow

    International Nuclear Information System (INIS)

    Celsis, P.; Chan, M.; Marc-Vergnes, J.P.; Sveinsdottir, E.; Goldman, T.G.; Henriksen, L.; Paulson, O.B.; Stokely, E.M.; Lassen, N.A.

    1982-01-01

    This paper illustrates the capabilities of single-photon emission tomography in imaging local cerebral blood flows in man. The results purport the conclusion that a fairly good improvement has been achieved when compared to stationary detectors and that single-photon emission tomography is a well-suited tool for studying cerebral hemodynamics, especially within the framework of clinical studies [fr

  2. Coupling two iteratives algorithms for density measurements by computerized tomography

    International Nuclear Information System (INIS)

    Silva, L.E.M.C.; Santos, C.A.C.; Borges, J.C.; Frenkel, A.D.B.; Rocha, G.M.

    1986-01-01

    This work develops a study for coupling two iteratives algotithms for density measurements by computerized tomography. Tomographies have been obtained with an automatized prototype, controled by a microcomputer, projected and assembled in the Nuclear Instrumentation Laboratory, at COPPE/UFRJ. Results show a good performance of the tomographic system, and demonstrate the validity of the method of calculus adopted. (Author) [pt

  3. Positron emission tomography of the heart

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-01-01

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

  4. Positron emission tomography in drug development

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  5. Neutron stimulated emission computed tomography: Background corrections

    International Nuclear Information System (INIS)

    Floyd, Carey E.; Sharma, Amy C.; Bender, Janelle E.; Kapadia, Anuj J.; Xia, Jessie Q.; Harrawood, Brian P.; Tourassi, Georgia D.; Lo, Joseph Y.; Kiser, Matthew R.; Crowell, Alexander S.; Pedroni, Ronald S.; Macri, Robert A.; Tajima, Shigeyuki; Howell, Calvin R.

    2007-01-01

    Neutron stimulated emission computed tomography (NSECT) is an imaging technique that provides an in-vivo tomographic spectroscopic image of the distribution of elements in a body. To achieve this, a neutron beam illuminates the body. Nuclei in the body along the path of the beam are stimulated by inelastic scattering of the neutrons in the beam and emit characteristic gamma photons whose unique energy identifies the element. The emitted gammas are collected in a spectrometer and form a projection intensity for each spectral line at the projection orientation of the neutron beam. Rotating and translating either the body or the beam will allow a tomographic projection set to be acquired. Images are reconstructed to represent the spatial distribution of elements in the body. Critical to this process is the appropriate removal of background gamma events from the spectrum. Here we demonstrate the equivalence of two background correction techniques and discuss the appropriate application of each

  6. Positron emission tomography of the heart

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  7. Applications of positron emission tomography to psychiatry

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  8. Motion correction in thoracic positron emission tomography

    CERN Document Server

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

    2015-01-01

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

  9. Positron emission tomography and basal ganglia functions

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Motohiro; Otsuka, Makoto; Taniwaki, Koukyo; Hosokawa, Shinichi; Kuwabara, Yasuo; Ichiya, Yuichi [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1990-05-01

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

  10. Positron emission tomography and basal ganglia functions

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  11. Partial Volume Effects correction in emission tomography

    International Nuclear Information System (INIS)

    Le Pogam, Adrien

    2010-01-01

    Partial Volume Effects (PVE) designates the blur commonly found in nuclear medicine images and this PhD work is dedicated to their correction with the objectives of qualitative and quantitative improvement of such images. PVE arise from the limited spatial resolution of functional imaging with either Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT). They can be defined as a signal loss in tissues of size similar to the Full Width at Half Maximum (FWHM) of the PSF of the imaging device. In addition, PVE induce activity cross contamination between adjacent structures with different tracer uptakes. This can lead to under or over estimation of the real activity of such analyzed regions. Various methodologies currently exist to compensate or even correct for PVE and they may be classified depending on their place in the processing chain: either before, during or after the image reconstruction process, as well as their dependency on co-registered anatomical images with higher spatial resolution, for instance Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). The voxel-based and post-reconstruction approach was chosen for this work to avoid regions of interest definition and dependency on proprietary reconstruction developed by each manufacturer, in order to improve the PVE correction. Two different contributions were carried out in this work: the first one is based on a multi-resolution methodology in the wavelet domain using the higher resolution details of a co-registered anatomical image associated to the functional dataset to correct. The second one is the improvement of iterative deconvolution based methodologies by using tools such as directional wavelets and curvelets extensions. These various developed approaches were applied and validated using synthetic, simulated and clinical images, for instance with neurology and oncology applications in mind. Finally, as currently available PET/CT scanners incorporate more

  12. 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)

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  14. The Positron Emission Tomography. A diagnostic technique

    International Nuclear Information System (INIS)

    Salvadori, P.

    2001-01-01

    Positron Emission Tomography (PET) is a new imaging modality, which is able to assess non-invasively the biochemical mechanisms, underlying physiological and pathophysiological processes in vivo in humans. The technique relies on the administration of radioactive tracers labeled with short-lived positron emitters, which need to be produced on site via a particle accelerator (cyclotron). Radionuclides are produced upon request and formulated into biologically active organic molecules having precise pharmacokinetics and specificity. The radiotracer can be detected by the PET scanner and represented as tomographic sections (images of body sections) showing its regional distribution and concentration. This makes it possible to address clinical questions concerning occurrence and evolution of many diseases as well as their response to therapy. The ability to image (measure) biological processes and not only anatomy enables PET to explore diseases in the very early stage, including those diseases which are not related to modifications of organ structure (e.g. psychiatric diseases, metabolic disorders, biochemical disfunction). PET plays a major role, in conjunction with the other imaging modalities, to improve diagnosis capabilities and disease mechanism understanding [it

  15. A continuation method for emission tomography

    International Nuclear Information System (INIS)

    Lee, M.; Zubal, I.G.

    1993-01-01

    One approach to improved reconstructions in emission tomography has been the incorporation of additional source information via Gibbs priors that assume a source f that is piecewise smooth. A natural Gibbs prior for expressing such constraints is an energy function E(f,l) defined on binary valued line processes l as well as f. MAP estimation leads to the difficult problem of minimizing a mixed (continuous and binary) variable objective function. Previous approaches have used Gibbs 'potential' functions, φ(f v ) and φ(f h ), defined solely on spatial derivatives, f v and f h , of the source. These φ functions implicitly incorporate line processes, but only in an approximate manner. The correct φ function, φ * , consistent with the use of line processes, leads to difficult minimization problems. In this work, the authors present a method wherein the correct φ * function is approached through a sequence of smooth φ functions. This is the essence of a continuation method in which the minimum of the energy function corresponding to one member of the φ function sequence is used as an initial condition for the minimization of the next, less approximate, stage. The continuation method is implemented using a GEM-ICM procedure. Simulation results show improvement using the continuation method relative to using φ * alone, and to conventional EM reconstructions

  16. Amorphous silicon detectors in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-12-01

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

  17. 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

  18. Amorphous silicon detectors in positron emission tomography

    International Nuclear Information System (INIS)

    Conti, M.; Perez-Mendez, V.

    1989-12-01

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

  19. 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

  20. Positron emission tomography for the assessment of myocardial viability

    International Nuclear Information System (INIS)

    Schelbert, H.R.

    1991-01-01

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

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

    NARCIS (Netherlands)

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

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

  2. Positron emission tomography of incidentally detected small pulmonary nodules

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  3. Positron emission tomography now and in the future

    International Nuclear Information System (INIS)

    Vaalburg, W.

    1987-01-01

    A survey is given of positron emission tomography used in nuclear medicine. The production of positron emitting radionuclides is discussed. The development of positron detectors is described. The application of positron emission tomography in cardiology, oncology and neurology is treated. The authors conclude that PET is a unique method to examine metabolic processes, although the method is still in its infancy. 7 refs.; 1 table

  4. Positron emission tomography and cerebral metabolism

    International Nuclear Information System (INIS)

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

    1979-01-01

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

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

    International Nuclear Information System (INIS)

    Romero, J.A.; Kim, E.E.; Tresukosol, D.; Kudelka, A.P.; Edwards, C.L.; Kavanagh, J.J.

    1995-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  7. 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...

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  9. Hybrid Single Photon Emission Computed Tomography/Computed Tomography Sulphur Colloid Scintigraphy in Focal Nodular Hyperplasia

    International Nuclear Information System (INIS)

    Bhoil, Amit; Gayana, Shankramurthy; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2013-01-01

    It is important to differentiate focal nodular hyperplasia (FNH), a benign condition of liver most commonly affecting women, from other neoplasm such as hepatic adenoma and metastasis. The functional reticuloendothelial features of FNH can be demonstrated by scintigraphy. We present a case of breast cancer in whom fluorodeoxyglucose positron emission tomography/computerized tomography (CT) showed a homogenous hyperdense lesion in liver, which on Tc99m sulfur colloid single-photon emission computed tomography/CT was found to have increased focal tracer uptake suggestive of FNH

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-04-01

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

  11. Single photon emission computed tomography and oth selected computer topics

    International Nuclear Information System (INIS)

    Frey, G.D.

    1981-01-01

    This book, the proceedings of a meeting in January 1980, contains 21 papers. Thirteen are devoted to aspects of emission tomography, four to nuclear cardiology, and five to other topics. The initial set of papers consists of reviews of the single photon emission tomography process. These include transverse axial tomography using scintillation cameras and other devices, longitudinal section tomography, and pin-hole and slant-hole systems. These reviews are generally well done, but as might be expected, lack any coherence from paper to paper. The papers on nuclear cardiology include several of Fourier analysis in nuclear cardiology and one on shunt quantification. Other clinical papers are on quantifying Tc-99m glucoheptonate uptake in the brain and on iron-59 retention studies. A general criticism of the book is the poor quality of photographic reproductions

  12. Diagnostic value of sectional images obtained by emission tomography

    International Nuclear Information System (INIS)

    Roucayrol, J.C.

    1981-01-01

    It is now possible to obtain clear images of the various planes in and around a structure with ultra-sounds (echotomography), X-rays (computerized tomography) and recently, gamma-rays from radioactive substances (emission tomography). Axial transverse tomography, which is described here, is to conventional scintigraphy what CT scan is to radiography. It provides images of any structure capable of concentrating sufficiently a radioactive substance administered intravenously. These images are perpendicular to the longitudinal axis of the body. As shown by examples in the liver, lungs and myocardium, lesions which had passed unnoticed with other exploratory techniques can now be demonstrated, and the location, shape and extension of known lesions can be more accurately assessed. Emission tomography already has its place in modern diagnostic procedures side by side with echotomography and CT scan [fr

  13. Detectors for high resolution dynamic positron emission tomography

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  14. Diagnosis of dementia with single photon emission computed tomography

    International Nuclear Information System (INIS)

    Jagust, W.J.; Budinger, T.F.; Reed, B.R.

    1987-01-01

    Single photon emission computed tomography is a practical modality for the study of physiologic cerebral activity in vivo. We utilized single photon emission computed tomography and N-isopropyl-p-iodoamphetamine iodine 123 to evaluate regional cerebral blood flow in nine patients with Alzheimer's disease (AD), five healthy elderly control subjects, and two patients with multi-infarct dementia. We found that all subjects with AD demonstrated flow deficits in temporoparietal cortex bilaterally, and that the ratio of activity in bilateral temporoparietal cortex to activity in the whole slice allowed the differentiation of all patients with AD from both the controls and from the patients with multi-infarct dementia. Furthermore, this ratio showed a strong correlation with disease severity in the AD group. Single photon emission computed tomography appears to be useful in the differential diagnosis of dementia and reflects clinical features of the disease

  15. Quantification in single photon emission computed tomography (SPECT)

    International Nuclear Information System (INIS)

    Buvat, Irene

    2005-01-01

    The objective of this lecture is to understand the possibilities and limitations of the quantitative analysis of single photon emission computed tomography (SPECT) 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 - quantification in SPECT, problems and correction methods: Attenuation, scattering, un-stationary spatial resolution, partial volume effect, movement, tomographic reconstruction, calibration; 3 - Synthesis: actual quantification accuracy; 4 - Beyond the activity concentration measurement

  16. New detector developments for high resolution positron emission tomography

    International Nuclear Information System (INIS)

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

    1998-01-01

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

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

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

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

  18. 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

  19. 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Tuberculosis: Spectrum of Manifestations.

    Science.gov (United States)

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

    2017-01-01

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

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

    International Nuclear Information System (INIS)

    Kettler, Nele

    2011-01-01

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

  1. 3D fast reconstruction in positron emission tomography

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  2. Time-of-flight positron emission tomography and associated detectors

    International Nuclear Information System (INIS)

    Vacher, J.; Allemand, R.; Campagnolo, R.

    1983-04-01

    An analysis of the timing capabilities of the detectors (scintillators and photomultipliers) in time-of-flight positron emission tomography is presented. The advantages of BaF 2 compared with CsF for the futur tomographs are evaluated [fr

  3. Cobalt-55 positron emission tomography in recurrent ischaemic stroke

    NARCIS (Netherlands)

    De Reuck, J; Santens, P; Keppens, J; De Bleecker, J; Strijckmans, K; Goethals, P; Lemahieu, [No Value; Korf, J

    The present study investigates if Cobalt-55 (Co-55) positron emission tomography (PET) allows us to distinguish and detect recent, recurrent strokes in patients who had already suffered a previous infarct in the same vascular territory. Fourteen patients with recurrent strokes underwent a Co-55 PET

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-03-01

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

  5. Positron emission tomography in drug development and drug evaluation

    NARCIS (Netherlands)

    Paans, AMJ; Vaalburg, W

    2000-01-01

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

  6. MR imaging and positron emission tomography of cortical heterotopia

    Energy Technology Data Exchange (ETDEWEB)

    Bairamian, D.; Di Chiro, G.; Theodore, W.H.; Holmes, M.D.; Dorwart, R.H.; Larson, S.M.

    1985-11-01

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

  7. MR imaging and positron emission tomography of cortical heterotopia

    International Nuclear Information System (INIS)

    Bairamian, D.; Di Chiro, G.; Theodore, W.H.; Holmes, M.D.; Dorwart, R.H.; Larson, S.M.

    1985-01-01

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

  8. Amyloid-β positron emission tomography imaging probes

    DEFF Research Database (Denmark)

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

    2013-01-01

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

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

    NARCIS (Netherlands)

    Paans, AMJ

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

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

    International Nuclear Information System (INIS)

    Steinling, M.; Samson, Y.

    1999-01-01

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

  11. High resolution and high speed positron emission tomography data acquisition

    International Nuclear Information System (INIS)

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

    1986-01-01

    High resolution positron emission tomography (PET) requires many detectors. Thus, data collection systems for PET must have high data rates, wide data paths, and large memories to histogram the events. This design uses the VMEbus to cost effectively provide these features. It provides for several modes of operation including real time sorting, list mode data storage, and replay of stored list mode data

  12. Positron emission tomography in presurgical diagnosis of partial epilepsies

    International Nuclear Information System (INIS)

    Hajek, M.; Leenders, K.L.; Wieser, H.G.

    1992-01-01

    We present results of studies in which positron emission tomography was applied to the presurgical evaluation of epileptics. Emphasis is placed on results of PET studies with various tracers in partial epilepsies and on the use of PET in age-related epileptic syndromes in children. (orig.) [de

  13. 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...

  14. 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.

  15. 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

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

    NARCIS (Netherlands)

    Disselhorst, Johannes Antonius

    2011-01-01

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

  17. New Possibilities of Positron-Emission Tomography

    Science.gov (United States)

    Volobuev, A. N.

    2018-01-01

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

  18. Attenuation correction using simultaneous emission - transmission tomography

    International Nuclear Information System (INIS)

    Ljubenov, V.; Marinkovic, P.

    1998-01-01

    In order to reduce degrading influence of attenuation on SPECT image quality, possibility for correction, based on simultaneous emission / transmission measurements, is discussed. Numerical photon transport simulations through the phantom and acquisition of of tomographic projections are performed by using Monte Carlo code MCNP-4A. Amount of contamination in transmission data due to photon Compton scattering for emission energy window is specially analyzed and appropriate spatial depending 'noise / signal' factors for three different external sources, applied with Tc-99m, are determined (author)

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

    Science.gov (United States)

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

    2014-08-01

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

  20. Hybrid Gama Emission Tomography (HGET): FY16 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Erin A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Smith, Leon E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wittman, Richard S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Campbell, Luke W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Deshmukh, Nikhil S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zalavadia, Mital A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Batie, Margo A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mozin, Vladimir V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-01

    Current International Atomic Energy Agency (IAEA) methodologies for the verification of fresh low-enriched uranium (LEU) and mixed oxide (MOX) fuel assemblies are volume-averaging methods that lack sensitivity to individual pins. Further, as fresh fuel assemblies become more and more complex (e.g., heavy gadolinium loading, high degrees of axial and radial variation in fissile concentration), the accuracy of current IAEA instruments degrades and measurement time increases. Particularly in light of the fact that no special tooling is required to remove individual pins from modern fuel assemblies, the IAEA needs new capabilities for the verification of unirradiated (i.e., fresh LEU and MOX) assemblies to ensure that fissile material has not been diverted. Passive gamma emission tomography has demonstrated potential to provide pin-level verification of spent fuel, but gamma-ray emission rates from unirradiated fuel emissions are significantly lower, precluding purely passive tomography methods. The work presented here introduces the concept of Hybrid Gamma Emission Tomography (HGET) for verification of unirradiated fuels, in which a neutron source is used to actively interrogate the fuel assembly and the resulting gamma-ray emissions are imaged using tomographic methods to provide pin-level verification of fissile material concentration.

  1. 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...

  2. 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)

  3. Single photon emission computed tomography in children with idiopathic seizures

    International Nuclear Information System (INIS)

    Hara, Masafumi; Takahashi, Mutsumasa; Kojima, Akihiro; Shimomura, Osamu; Kinoshita, Rumi; Tomiguchi, Seiji; Taku, Keiichi; Miike, Teruhisa

    1991-01-01

    Single photon emission computed tomography (SPECT) with N-isoprophyl-p [ 123 I]-iodoamphetamine (IMP), X-ray computed tomography (X-CT), and magnetic resonance imaging (MRI) were performed in 20 children with idiopathic seizures. In children with idiopathic seizures, SPECT could detect the abnormal sites at the highest rate (45%) compared with CT (10%) and MRI (12%), but the abnormal sites on SPECT correlated poorly with the foci on electroencephalograph (EEG). Idiopathic epilepsy with hypoperfusion on SPECT was refractory to treatment and was frequently associated with mental and/or developmental retardation. Perfusion defects on SPECT scans probably affect the development and maturation of the brain in children. (author)

  4. Positron emission tomography of FDG in schizophrenia

    International Nuclear Information System (INIS)

    Sargent, T. III; Kusubov, N.

    1986-01-01

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

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

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

    International Nuclear Information System (INIS)

    Guermazi, Fadhel; Hamza, F; Amouri, W.; Charfeddine, S.; Kallel, S.; Jardak, I.

    2013-01-01

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

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

    International Nuclear Information System (INIS)

    Singh, Nidhi; Kumar, Rakesh; Malhotra, Arun; Bhalla, Ashu Seith; Kumar, Uma; Sood, Rita

    2005-01-01

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

  8. Applications of X-ray Computed Tomography and Emission Computed Tomography

    International Nuclear Information System (INIS)

    Seletchi, Emilia Dana; Sutac, Victor

    2005-01-01

    Computed Tomography is a non-destructive imaging method that allows visualization of internal features within non-transparent objects such as sedimentary rocks. Filtering techniques have been applied to circumvent the artifacts and achieve high-quality images for quantitative analysis. High-resolution X-ray computed tomography (HRXCT) can be used to identify the position of the growth axis in speleothems by detecting subtle changes in calcite density between growth bands. HRXCT imagery reveals the three-dimensional variability of coral banding providing information on coral growth and climate over the past several centuries. The Nuclear Medicine imaging technique uses a radioactive tracer, several radiation detectors, and sophisticated computer technologies to understand the biochemical basis of normal and abnormal functions within the brain. The goal of Emission Computed Tomography (ECT) is to accurately determine the three-dimensional radioactivity distribution resulting from the radiopharmaceutical uptake inside the patient instead of the attenuation coefficient distribution from different tissues as obtained from X-ray Computer Tomography. ECT is a very useful tool for investigating the cognitive functions. Because of the low radiation doses associated with Positron Emission Tomography (PET), this technique has been applied in clinical research, allowing the direct study of human neurological diseases. (authors)

  9. Brain receptor single-photon emission computer tomography with 123I Datscan in Parkinson's disease

    International Nuclear Information System (INIS)

    Minchev, D.; Peshev, N.; Kostadinova, I.; Grigorova, O.; Trindev, P.; Shotekov, P.

    2005-01-01

    Clinical aspects of Parkinson's disease are not enough for the early diagnosis of the disease. Positron emission tomography and the receptor single - photon emission tomography can be used for imaging functional integrity of nigrostriatal dopaminergic structures. 24 patient (17 men and 7 women) were investigated. 20 of them are with Parkinson's disease and 4 are with essential tremor. The radiopharmaceutical - 123I-Datscan (ioflupane, bind with 123I) represent a cocaine analogue with selective affinity to dopamine transporters, located in the dopaminergic nigrostriatal terminals in the striatum. Single - photon emission computer tomography was performed with SPECT gamma camera (ADAC, SH Epic detector). The scintigraphic study was made 3 to 6 hours after intravenous injection of the radiopharmaceutical - 123I- Datscan in dose 185 MBq. 120 frames are registered with duration of each one 22 seconds and gamma camera rotation 360. After generation of transversal slices we generated two composites pictures. The first composite picture image the striatum, the second - the occipital region. Two ratios were calculated representing the uptake of the radiopharmaceutical in the left and right striatum. Qualitative and quantitative criteria were elaborated for evaluating the scintigraphic patterns. Decreased, nonhomogeneous and asymmetric uptake of the radiopharmaceutical coupled with low quantitative parameters in range from 1.44 to 2.87 represents the characteristic scintigraphic pattern for Parkinson's disease with clear clinical picture. Homogenous with high intensity and symmetric uptake of the radiopharmaceutical in the striatum coupled with his clear frontier and with quantitative parameters up to 4.40 represent the scintigraphic pattern in two patients with essential tremor. Receptor single - photon emission computer tomography with 123I - Datscan represents an accurate nuclear-medicine method for precise diagnosis of Parkinson's disease and for its differentiation from

  10. Positron Emission Tomography: Principles, Technology, and Recent Developments

    Science.gov (United States)

    Ziegler, Sibylle I.

    2005-04-01

    Positron emission tomography (PET) is a nuclear medical imaging technique for quantitative measurement of physiologic parameters in vivo (an overview of principles and applications can be found in [P.E. Valk, et al., eds. Positron Emission Tomography. Basic Science and Clinical Practice. 2003, Springer: Heidelberg]), based on the detection of small amounts of posi-tron-emitter-labelled biologic molecules. Various radiotracers are available for neuro-logical, cardiological, and oncological applications in the clinic and in research proto-cols. This overview describes the basic principles, technology, and recent develop-ments in PET, followed by a section on the development of a tomograph with ava-lanche photodiodes dedicated for small animal imaging as an example of efforts in the domain of high resolution tomographs.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    Science.gov (United States)

    Joshi, Prathamesh; Lele, Vikram; Shah, Hardik

    2013-01-01

    Xanthogranulomatous pyelonephritis (XGNP) is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction. This condition can clinically present as recurrent urinary tract infections, flank pain, hematuria, and occasionally sepsis, and weight loss. This condition is usually associated with obstructing renal calculus. We present 18-fluorodeoxyglucose positron emission tomography-computed tomography (18-FDG PET/CT) findings in an elderly male suffering from pyrexia and weight loss and suspected urinary tract infection. PET/CT findings in this case lead to diagnosis of XGNP. This diagnosis should be kept in mind while evaluating similar symptoms and PET/CT scan findings. PMID:24019680

  13. Position emission tomography with or without computed tomography in the primary staging of Hodgkin's lymphoma

    DEFF Research Database (Denmark)

    Hutchings, Martin; Loft, Annika; Hansen, Mads

    2006-01-01

    BACKGROUND AND OBJECTIVES: In order to receive the most appropriate therapy, patients with Hodgkin's lymphoma (HL) must be accurately stratified into different prognostic staging groups. Computed tomography (CT) plays a pivotal role in the conventional staging. The aim of the present study...... was to investigate the value of positron emission tomography using 2-[18F]fluoro-2-deoxy-D-glucose (FDG-PET) and combined FDG-PET/CT for the staging of HL patients, and the impact on the choice of treatment. DESIGN AND METHODS: Ninety-nine consecutive, prospectively included patients had FDG-PET and CT...

  14. Application of positron emission tomography in the heart

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This report discusses experimental and clinical applications of positron emission tomography to the heart, including measurements of blood flow to the myocardium and studies of metabolism and experimental injury. Most initial clinical studies have concentrated on ischemic heart disease, but the technique also has potential for investigation of cardiomyopathies, studying the neural control of the heart, and evaluating the effects of drugs on cardiac tissues

  15. Contribution of positron emission tomography in pleural disease.

    OpenAIRE

    Duysinx, Bernard; Corhay, Jean-Louis; Larock, Marie-Paule; Withofs, Nadia; Bury, Thierry; Hustinx, Roland; Louis, Renaud

    2010-01-01

    INTRODUCTION: Positron emission tomography (PET) now plays a clear role in oncology, especially in chest tumours. We discuss the value of metabolic imaging in characterising pleural pathology in the light of our own experience and review the literature. BACKGROUND: PET is particularly useful in characterising malignant pleural pathologies and is a factor of prognosis in mesothelioma. Metabolic imaging also provides clinical information for staging lung cancer, in researching the primary tumou...

  16. Simulated annealing image reconstruction for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sundermann, E; Lemahieu, I; Desmedt, P [Department of Electronics and Information Systems, University of Ghent, St. Pietersnieuwstraat 41, B-9000 Ghent, Belgium (Belgium)

    1994-12-31

    In Positron Emission Tomography (PET) images have to be reconstructed from moisy projection data. The noise on the PET data can be modeled by a Poison distribution. In this paper, we present the results of using the simulated annealing technique to reconstruct PET images. Various parameter settings of the simulated annealing algorithm are discussed and optimized. The reconstructed images are of good quality and high contrast, in comparison to other reconstruction techniques. (authors). 11 refs., 2 figs.

  17. Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography in Disseminated Cryptococcosis

    Science.gov (United States)

    Tripathy, Sarthak; Parida, Girish Kumar; Roy, Shambo Guha; Singhal, Abhinav; Mallick, Saumya Ranjan; Tripathi, Madhavi; Shamim, Shamim Ahmed

    2017-01-01

    Disseminated cryptococcosis without pulmonary involvement is a very rare phenomenon. Patterns of organ involvement in cryptococcosis resemble various other infective conditions as well as malignant conditions on fluorodeoxyglucose positron emission tomography–computed tomography. We present a case of a 43-year-old male patient who had disseminated cryptococcosis. The rarity of the case being noninvolvement of lungs and meninges and resembling more like lymphoma due to the diffuse involvement of the lymph nodes on both sides of the diaphragm. PMID:29142368

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

    International Nuclear Information System (INIS)

    Chepel, V.Yu.

    1993-01-01

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

  19. Measurement of brain pH with positron emission tomography

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  20. Simulated annealing image reconstruction for positron emission tomography

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  1. Measurement of liver volume by emission computed tomography

    International Nuclear Information System (INIS)

    Kan, M.K.; Hopkins, G.B.

    1979-01-01

    In 22 volunteers without clinical or laboratory evidence of liver disease, liver volume was determined using single-photon emission computed tomography (ECT). This technique provided excellent object contrast between the liver and its surroundings and permitted calculation of liver volume without geometric assumptions about the liver's configuration. Reproducibility of results was satisfactory, with a root-mean-square error of less than 6% between duplicate measurements in 15 individuals. The volume measurements were validated by the use of phantoms

  2. Method of multiplanar emission tomography and apparatus therefor

    International Nuclear Information System (INIS)

    Gottschalk, S.C.; Smith, K.A.; Wake, R.H.

    1981-01-01

    A method of emission tomography using a gamma camera and a rotating collimator having an array of a large number of slanted, small diameter holes. A planar projection corresponding to each angular orientation assumed by the collimator is recorded. From these series of planar projections, a three-dimensional simulation model is reconstructed by an iterative algorithm which approximates the emitting object. The simulated model comprises multiple separable planes

  3. A Prototype for Passive Gamma Emission Tomography

    International Nuclear Information System (INIS)

    Honkamaa, T.; Levai, F.; Berndt, R.; Schwalbach, P.; Vaccaro, S.; ); Turunen, A.

    2015-01-01

    Combined efforts of multiple stakeholders of the IAEA Support Programme task JNT 1510: ''Prototype of passive gamma emission tomograph (PGET)'', resulted in the design, manufacturing and extensive testing of an advanced verification tool for partial defect testing on light water reactor spent fuel. The PGET has now reached a proven capability of detecting a single missing or substituted pin inside a BWR and VVER-440 fuel assemblies. The task started in 2004 and it is planned to be finished this year. The PGET head consists of two banks of 104 CdTe detectors each with integrated data acquisition electronics. The CdTe detectors are embedded in tungsten collimators which can be rotated around the fuel element using an integrated stepping motor mounted on a rotating table. All components are packed inside a toroid watertight enclosure. Control, data acquisition and image reconstruction analysis is fully computerized and automated. The design of the system is transportable and suitable for safeguards verifications in spent fuel ponds anywhere. Four test campaigns have been conducted. In 2009, the first test in Ringhals NPP failed collecting data but demonstrated suitability of the PGET for field deployments. Subsequent tests on fuel with increasing complexity were all successful (Ispra, Italy (2012), Olkiluoto, Finland (2013) and Loviisa, Finland (2014)). The paper will present the PGET design, results obtained from the test campaigns and mention also drawbacks that were experienced in the project. The paper also describes further tests which would allow evaluating the capabilities and limitations of the method and the algorithm used. Currently, the main technical shortcoming is long acquisition time, due to serial control and readout of detectors. With redesigned electronics it can be expected that the system would be able to verify a VVER-440 assembly in five minutes, which meets the IAEA user requirements. (author)

  4. Fast Neutron Emission Tomography of Used Nuclear Fuel Assemblies

    Science.gov (United States)

    Hausladen, Paul; Iyengar, Anagha; Fabris, Lorenzo; Yang, Jinan; Hu, Jianwei; Blackston, Matthew

    2017-09-01

    Oak Ridge National Laboratory is developing a new capability to perform passive fast neutron emission tomography of spent nuclear fuel assemblies for the purpose of verifying their integrity for international safeguards applications. Most of the world's plutonium is contained in spent nuclear fuel, so it is desirable to detect the diversion of irradiated fuel rods from an assembly prior to its transfer to ``difficult to access'' storage, such as a dry cask or permanent repository, where re-verification is practically impossible. Nuclear fuel assemblies typically consist of an array of fuel rods that, depending on exposure in the reactor and consequent ingrowth of 244Cm, are spontaneous sources of as many as 109 neutrons s-1. Neutron emission tomography uses collimation to isolate neutron activity along ``lines of response'' through the assembly and, by combining many collimated views through the object, mathematically extracts the neutron emission from each fuel rod. This technique, by combining the use of fast neutrons -which can penetrate the entire fuel assembly -and computed tomography, is capable of detecting vacancies or substitutions of individual fuel rods. This paper will report on the physics design and component testing of the imaging system. This material is based upon work supported by the U.S. Department of Energy, Office of Defense Nuclear Nonproliferation Research and Development within the National Nuclear Security Administration, under Contract Number DE-AC05-00OR22725.

  5. Emission tomography: quantitative aspects in metabolic and physiopathologic studies

    International Nuclear Information System (INIS)

    Yerouchalmi-Soussaline, F.

    1984-11-01

    This thesis presents instrumental and data processing studies developped in emission tomography in man, using gamma and positron emitting tracers. High contrast visualisation of volume distribution of tracers in the organs, kinetic studies and measurements of radioactive concentration or of other clinical parameters necessitate a detailed analysis of all physical factors limiting the accuracy of the measure; therefore, development of adapted imaging devices and data processing techniques, together with models describing correctly the phenomena under study are to be carried out. Thus, in single photon (gamma) emission tomography an image reconstruction strategy is elaborated, based on an analytical model for the ill-posed problem including the attenuation effect. In positron emission tomography, the time-of-flight information combined with the reconstruction technique is used in the design of a first prototype imaging device which performance is presented and evaluated in a clinical environment. Moreover, a priori or a posteriori techniques correcting for Compton diffusion events, limited statistics and limited resolutions, are proposed and discussed for the improvement of regional measurement accuracy, in metabolic and physiopathologic studies [fr

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

    Science.gov (United States)

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

    2017-07-27

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

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  8. Inductively coupled plasma-atomic emission spectroscopy

    International Nuclear Information System (INIS)

    Winge, R.K.; Fassel, V.A.; Peterson, V.J.; Floyd, M.A.

    1985-01-01

    This atlas of inductively coupled plasma-atomic emission spectroscopy records the spectra of the elements in a way that would reveal the general nature of the spectra, in all their simplicity or complexity; and offers a definitive summary of the most prominent spectral lines of the elements, i.e., those most likely to be useful for the determination of trace and ultratrace concentrations; it provides reliable estimates, based on the recorded experimental spectra, of the powers of detection of the listed prominent lines; and assesses the very important problem of spectral interferences. The atlas is composed of three main sections. Part I is concerned with the historical aspects of compilations of spectral information. Part II is based on 232 wavelength scans of 70 elements. Each of the wavelength scans covers an 80 nm spectral region. These scans allow a rapid comparison of the background and spectral line intensities emitted in the ICP and provide a ready means for identification of the most prominent lines of each element and for estimation of the trace element analytical capabilities of these lines. A listing of 973 prominent lines with associated detection limits is also presented. Part III addresses the problem of spectral interferences. On this topic a detailed collection of coincidence profiles is presented for 281 of the most prominent lines, each with profiles of ten of the most prevalent concomitants superimposed. (Auth.)

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

    International Nuclear Information System (INIS)

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

    1979-01-01

    Positron emission tomography (PET) offers an entirely new approach to the study of the pathophysiology of cerebral ischemic disorders. This is so because for the first time it is possible to obtain functional tomographic images that represent cerebral perfusion and metabolism in a regional basis. We report here a study of cerebral blood flow and oxygen extraction by means of the 15 O inhalation technique in a large number of human hemispheric infarctions. PET imaging with this non-invasive technique has permitted the description of hitherto unreported focal patterns of changes in the CBF/EO2 couple that may have important pathophysiologic and prognostic implications

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

    DEFF Research Database (Denmark)

    Bouchelouche, Kirsten; Turkbey, Baris; Choyke, Peter

    2010-01-01

    , and molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI...

  11. Single photon emission computed tomography in AIDS dementia complex

    International Nuclear Information System (INIS)

    Pohl, P.; Vogl, G.; Fill, H.; Roessler, H.Z.; Zangerle, R.; Gerstenbrand, F.

    1988-01-01

    Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder

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

    Science.gov (United States)

    Wu, Chen-Xi; Zhu, Zhao-Hui

    2014-01-01

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

  13. 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

  14. 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)

  15. Positron emission tomography in a national research centre

    International Nuclear Information System (INIS)

    Weinreich, R.

    1989-01-01

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

  16. Imaging local brain function with emission computed tomography

    International Nuclear Information System (INIS)

    Kuhl, D.E.

    1984-01-01

    Positron emission tomography (PET) using 18 F-fluorodeoxyglucose (FDG) was used to map local cerebral glucose utilization in the study of local cerebral function. This information differs fundamentally from structural assessment by means of computed tomography (CT). In normal human volunteers, the FDG scan was used to determine the cerebral metabolic response to conrolled sensory stimulation and the effects of aging. Cerebral metabolic patterns are distinctive among depressed and demented elderly patients. The FDG scan appears normal in the depressed patient, studded with multiple metabolic defects in patients with multiple infarct dementia, and in the patients with Alzheimer disease, metabolism is particularly reduced in the parietal cortex, but only slightly reduced in the caudate and thalamus. The interictal FDG scan effectively detects hypometabolic brain zones that are sites of onset for seizures in patients with partial epilepsy, even though these zones usually appear normal on CT scans. The future prospects of PET are discussed

  17. 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

  18. 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].

  19. Positron emission tomography in minor ischemic stroke using oxygen-15 steady-state technique

    International Nuclear Information System (INIS)

    Pozzilli, C.; Itoh, M.; Matsuzawa, T.; Fukuda, H.; Abe, Y.; Sato, T.; Takeda, S.; Ido, T.

    1987-01-01

    A study with positron emission tomography (PET) was performed on 10 patients with ischemic stroke and mild disability. The patients underwent cerebral angiography, x-ray computed tomography (CT) scan and regional cerebral measurements of CBF, CMRO2, oxygen extraction ratio (OER), and cerebral blood volume (CBV). Only minor arterial involvement was detected by angiography. In all patients, PET images of functional defects were more extensive than the corresponding CT hypodensity, and there were statistically significant reductions in CBF, CMRO2, and CBF/CBV ratio as compared with control subjects. Half of the regions analyzed in the affected hemisphere demonstrated a disruption of the normal coupling between CBF and CMRO2 as reflected by OER values significantly higher or lower than those of the corresponding region of the contralateral hemisphere. The pathophysiological pattern of high OER combined with a reduction in CBF proportionally greater than the reduction in CMRO2 was particularly indicative of regional chronic hemodynamic compromise in these patients

  20. Contribution of positron emission tomography in pleural disease.

    Science.gov (United States)

    Duysinx, B; Corhay, J-L; Larock, M-P; Withofs, N; Bury, T; Hustinx, R; Louis, R

    2010-10-01

    Positron emission tomography (PET) now plays a clear role in oncology, especially in chest tumours. We discuss the value of metabolic imaging in characterising pleural pathology in the light of our own experience and review the literature. PET is particularly useful in characterising malignant pleural pathologies and is a factor of prognosis in mesothelioma. Metabolic imaging also provides clinical information for staging lung cancer, in researching the primary tumour in metastatic pleurisy and in monitoring chronic or recurrent pleural pathologies. PET should therefore be considered as a useful tool in the diagnosis of liquid or solid pleural pathologies. Copyright © 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  1. Positron emission tomography. Present status and Romanian perspectives

    International Nuclear Information System (INIS)

    Constantinescu, B.; Lungu, V.

    1995-01-01

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

  2. Kinetic modeling in pre-clinical positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  5. Functional imaging of the brain with positron emission tomography

    International Nuclear Information System (INIS)

    Alavi, A.; Reivich, M.; Jones, S.C.; Greenberg, J.H.; Wolf, A.P.

    1982-01-01

    An extensive review, with 191 references, of the development and diagnostic use of positron emission tomography (PET) of the brain is presented. An historical overview of functional studies of the brain reviews the use of nitrons oxide, 85 Kr and 133 Xe, [ 14 C]2-deoxyglucose, and [ 18 F]FDG. The [ 18 F]FDG technique allows the investigation of the effects of physiologic stimulation on the brain. Several studies using this technique are reported. The effects of stroke, seizure disorders, aging and dementia, and schizophrenia on cerebral metabolism as demosntrated by PET are explored

  6. 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

  7. An analysis of true- and false-positive results of vocal fold uptake in positron emission tomography-computed tomography imaging.

    Science.gov (United States)

    Seymour, N; Burkill, G; Harries, M

    2018-03-01

    Positron emission tomography-computed tomography with fluorine-18 fluorodeoxy-D-glucose has a major role in the investigation of head and neck cancers. Fluorine-18 fluorodeoxy-D-glucose is not a tumour-specific tracer and can also accumulate in benign pathology. Therefore, positron emission tomography-computed tomography scan interpretation difficulties are common in the head and neck, which can produce false-positive results. This study aimed to investigate patients detected as having abnormal vocal fold uptake on fluorine-18 fluorodeoxy-D-glucose positron emission tomography-computed tomography. Positron emission tomography-computed tomography scans were identified over a 15-month period where reports contained evidence of unilateral vocal fold uptake or vocal fold pathology. Patients' notes and laryngoscopy results were analysed. Forty-six patients were identified as having abnormal vocal fold uptake on positron emission tomography-computed tomography. Twenty-three patients underwent positron emission tomography-computed tomography and flexible laryngoscopy: 61 per cent of patients had true-positive positron emission tomography-computed tomography scans and 39 per cent had false-positive scan results. Most patients referred to ENT for abnormal findings on positron emission tomography-computed tomography scans had true-positive findings. Asymmetrical fluorine-18 fluorodeoxy-D-glucose uptake should raise suspicion of vocal fold pathology, accepting a false-positive rate of approximately 40 per cent.

  8. Efficacy of 3D-positron emission tomography/computed tomography for upper abdomen.

    Science.gov (United States)

    Murakami, Koji; Nakahara, Tadaki

    2014-04-01

    Recent advancement in computed tomography (CT) enables us to obtain high spatial resolution image and made it possible to construct extensive high-definition three-dimensional (3D) images. But a lack of contrast resolution in CT alone is still remained problem. Meanwhile, as fluorodeoxyglucose-positron emission tomography (PET) can visualize tumors in high contrast, we can create 3D images fusing the accumulation in tumors on PET/CT images. Such images can play the role of a "map of body" which makes it easy to understand the anatomical information before surgery. We also try to evaluate segmental liver function by using PET/CT fusion images. By using (11) C-methionine PET/contrast-enhanced CT, superior image quality compared to single photon emission computed tomography/CT can be obtained. CT, especially with contrast enhancement for obtaining anatomical imaging information plus PET for obtaining functional imaging information is a highly compatible combination, and adding these two types information will further increase clinical usefulness. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  9. Cone beam tomography of the heart using single-photon emission-computed tomography

    International Nuclear Information System (INIS)

    Gullberg, G.T.; Christian, P.E.; Zeng, G.L.; Datz, F.L.; Morgan, H.T.

    1991-01-01

    The authors evaluated cone beam single-photon emission-computed tomography (SPECT) of the heart. A new cone beam reconstruction algorithm was used to reconstruct data collected from short scan acquisitions (of slightly more than 180 degrees) of a detector anteriorally traversing a noncircular orbit. The less than 360 degrees acquisition was used to minimize the attenuation artifacts that result from reconstructing posterior projections of 201T1 emissions from the heart. The algorithm includes a new method for reconstructing truncated projections of background tissue activity that eliminates reconstruction ring artifacts. Phantom and patient results are presented which compare a high-resolution cone beam collimator (50-cm focal length; 6.0-mm full width at half maximum [FWHM] at 10 cm) to a low-energy general purpose (LEGP) parallel hole collimator (8.2-mm FWHM at 10 cm) which is 1.33 times more sensitive. The cone beam tomographic results are free of reconstruction artifacts and show improved spatial and contrast resolution over that obtained with the LEGP parallel hole collimator. The limited angular sampling restrictions and truncation problems associated with cone beam tomography do not deter from obtaining diagnostic information. However, even though these preliminary results are encouraging, a thorough clinical study is still needed to investigate the specificity and sensitivity of cone beam tomography

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    International Nuclear Information System (INIS)

    Morgan, P.P.

    1983-01-01

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

  12. Acute Calculous Cholecystitis Missed on Computed Tomography and Ultrasound but Diagnosed with Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    Directory of Open Access Journals (Sweden)

    Carina Mari Aparici

    2016-01-01

    Full Text Available We present a case of a 69-year-old patient who underwent ascending aortic aneurysm repair with aortic valve replacement. On postsurgical day 12, he developed leukocytosis and low-grade fevers. The chest computed tomography (CT showed a periaortic hematoma which represents a postsurgical change from aortic aneurysm repair, and a small pericardial effusion. The abdominal ultrasound showed cholelithiasis without any sign of cholecystitis. Finally, a fluorodeoxyglucose (FDG-positron emission tomography (PET/CT examination was ordered to find the cause of fever of unknown origin, and it showed increased FDG uptake in the gallbladder wall, with no uptake in the lumen. FDG-PET/CT can diagnose acute cholecystitis in patients with nonspecific clinical symptoms and laboratory results.

  13. First image from a combined positron emission tomography and field-cycled MRI system.

    Science.gov (United States)

    Bindseil, Geron A; Gilbert, Kyle M; Scholl, Timothy J; Handler, William B; Chronik, Blaine A

    2011-07-01

    Combining positron emission tomography and MRI modalities typically requires using either conventional MRI with a MR-compatible positron emission tomography system or a modified MR system with conventional positron emission tomography. A feature of field-cycled MRI is that all magnetic fields can be turned off rapidly, enabling the use of conventional positron emission tomography detectors based on photomultiplier tubes. In this demonstration, two photomultiplier tube-based positron emission tomography detectors were integrated with a field-cycled MRI system (0.3 T/4 MHz) by placing them into a 9-cm axial gap. A positron emission tomography-MRI phantom consisting of a triangular arrangement of positron-emitting point sources embedded in an onion was imaged in a repeating interleaved sequence of ∼1 sec MRI then 1 sec positron emission tomography. The first multimodality images from the combined positron emission tomography and field-cycled MRI system show no additional artifacts due to interaction between the systems and demonstrate the potential of this approach to combining positron emission tomography and MRI. Copyright © 2010 Wiley-Liss, Inc.

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Prognostic Evaluation of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Endometrial Cancer

    DEFF Research Database (Denmark)

    Vilstrup, Mie Holm; Jochumsen, Kirsten M; Hess, Søren

    2017-01-01

    .19-8.49) and 1.93 (0.80-4.68), respectively. Whole-body cTLG of greater than or equal to 176.1 g yielded a hazard ratio of 5.70 (1.94-16.78) for OS in a multivariate analysis. CONCLUSIONS: Preoperative SUVmax and cTLG showed potential as independent prognostic markers of OS in patients with primarily high...... and a preoperative F-fluorodeoxyglucose positron emission tomography/computed tomography before curatively intended treatment were included. The scans were evaluated using standard uptake values [maximum standard uptake value (SUVmax) and partial volume corrected (c) mean standardized uptake value (SUVmean...... proportional regression models were used for prognostic evaluation. RESULTS: Eighty-three patients (median age, 69.9 y; range, 26.8-91.1) with primarily high-risk endometrial cancer or suspected high The International Federation of Gynecology and Obstetrics stage were included. Mean follow-up time was 3...

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

    Directory of Open Access Journals (Sweden)

    Erdem Sürücü

    2016-10-01

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

  17. Positron emission tomography/computed tomography and radioimmunotherapy of prostate cancer

    DEFF Research Database (Denmark)

    Bouchelouche, Kirsten; Capala, Jacek; Oehr, Peter

    2009-01-01

    of a number of diagnostic and therapeutic strategies. J591, a monoclonal antibody, which targets the extracellular domain of prostate-specific membrane antigen, shows promising results. HER2 receptors may also have a potential as target for PET/CT imaging and RIT of advanced prostate cancer. SUMMARY: PET......PURPOSE OF REVIEW: Traditional morphologically based imaging modalities are now being complemented by positron emission tomography (PET)/computed tomography (CT) in prostate cancer. Metastatic prostate cancer is an attractive target for radioimmunotherapy (RIT) as no effective therapies...... are available. This review highlights the most important achievements within the last year in PET/CT and RIT of prostate cancer. RECENT FINDINGS: Conflicting results exist on the use of choline for detection of malignant disease in the prostate gland. The role of PET/CT in N-staging remains to be elucidated...

  18. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of primary pulmonary angiosarcomas

    International Nuclear Information System (INIS)

    Krishnamurthy, Arvind; Nayak, Deepika; Ramshankar, Vijayalakshmi; Majhi, Urmila

    2015-01-01

    Angiosarcoma is a malignant vascular tumor that originates from the mesenchymal cells which have undergone angioblastic differentiation. Pulmonary angiosarcomas are invariably (>90%) metastatic tumors form primaries of the skin, bone, liver, breast, or heart. Primary pulmonary angiosarcomas are exceedingly rare, with just about 20 cases being reported in the literature. We report an additional case with a brief review of the literature of a primary pulmonary angiosarcoma in a 26-year-old lady who presented with intractable hemoptysis. In addition, we highlight the potential of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography as an important diagnostic tool in the evaluation of this tumor and thus contribute to the existing sparse literature on this fascinating yet devastating disease

  19. F-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Appearance of Extramedullary Hematopoesis in a Case of Primary Myelofibrosis

    Science.gov (United States)

    Mukherjee, Anirban; Bal, Chandrasekhar; Tripathi, Madhavi; Das, Chandan Jyoti; Shamim, Shamim Ahmed

    2017-01-01

    A 44-year-old female with known primary myelofibrosis presented with shortness of breath. High Resolution Computed Tomography thorax revealed large heterogeneously enhancing extraparenchymal soft tissue density mass involving bilateral lung fields. F-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography revealed mildly FDG avid soft tissue density mass with specks of calcification involving bilateral lung fields, liver, and spleen. Subsequent histopathologic evaluation from the right lung mass was suggestive of extramedullary hematopoesis. PMID:28533647

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2012-08-01

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

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

    Science.gov (United States)

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

    2015-09-01

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

  4. Extensive tumor thrombus of hepatocellular carcinoma in the entire portal venous system detected on fluorodeoxyglucose positron emission tomography computed tomography

    International Nuclear Information System (INIS)

    Agrawal, Archi; Purandare, Nilendu; Shah, Sneha; Puranik, Ameya; Rangarajan, Venkatesh

    2013-01-01

    Detection of thrombus is usually an incidental finding on fluorodeoxyglucose positron emission tomography/computed tomography studies. Nevertheless this is an important finding in terms of disease prognostication and in planning the treatment strategy. We herein report a case of a 50-years-old male, a diagnosed case of hepatocellular carcinoma with extensive hypermetabolic thrombus involving the entire portal venous system. (author)

  5. Diagnosis of sinusoidal obstruction syndrome by positron emission tomography/computed tomography: report of two cases treated by defibrotide.

    Science.gov (United States)

    Gauthé, Mathieu; Bozec, Laurence; Bedossa, Pierre

    2014-11-01

    Sinusoidal obstruction syndrome (SOS) is a potentially fatal liver injury that mainly occurs after myeloablative chemotherapy. We report two cases of SOS investigated by 18F-fluorodeoxyglucose positron emission tomography/computed tomography and treated with defibrotide. © 2014 by the American Association for the Study of Liver Diseases.

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  7. 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.

  8. 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)

  9. Anti-3-[(18)F]FACBC positron emission tomography-computerized tomography and (111)In-capromab pendetide single photon emission computerized tomography-computerized tomography for recurrent prostate carcinoma: results of a prospective clinical trial.

    Science.gov (United States)

    Schuster, David M; Nieh, Peter T; Jani, Ashesh B; Amzat, Rianot; Bowman, F Dubois; Halkar, Raghuveer K; Master, Viraj A; Nye, Jonathon A; Odewole, Oluwaseun A; Osunkoya, Adeboye O; Savir-Baruch, Bital; Alaei-Taleghani, Pooneh; Goodman, Mark M

    2014-05-01

    We prospectively evaluated the amino acid analogue positron emission tomography radiotracer anti-3-[(18)F]FACBC compared to ProstaScint® ((111)In-capromab pendetide) single photon emission computerized tomography-computerized tomography to detect recurrent prostate carcinoma. A total of 93 patients met study inclusion criteria who underwent anti-3-[(18)F]FACBC positron emission tomography-computerized tomography plus (111)In-capromab pendetide single photon emission computerized tomography-computerized tomography for suspected recurrent prostate carcinoma within 90 days. Reference standards were applied by a multidisciplinary board. We calculated diagnostic performance for detecting disease. In the 91 of 93 patients with sufficient data for a consensus on the presence or absence of prostate/bed disease anti-3-[(18)F]FACBC had 90.2% sensitivity, 40.0% specificity, 73.6% accuracy, 75.3% positive predictive value and 66.7% negative predictive value compared to (111)In-capromab pendetide with 67.2%, 56.7%, 63.7%, 75.9% and 45.9%, respectively. In the 70 of 93 patients with a consensus on the presence or absence of extraprostatic disease anti-3-[(18)F]FACBC had 55.0% sensitivity, 96.7% specificity, 72.9% accuracy, 95.7% positive predictive value and 61.7% negative predictive value compared to (111)In-capromab pendetide with 10.0%, 86.7%, 42.9%, 50.0% and 41.9%, respectively. Of 77 index lesions used to prove positivity histological proof was obtained in 74 (96.1%). Anti-3-[(18)F]FACBC identified 14 more positive prostate bed recurrences (55 vs 41) and 18 more patients with extraprostatic involvement (22 vs 4). Anti-3-[(18)F]FACBC positron emission tomography-computerized tomography correctly up-staged 18 of 70 cases (25.7%) in which there was a consensus on the presence or absence of extraprostatic involvement. Better diagnostic performance was noted for anti-3-[(18)F]FACBC positron emission tomography-computerized tomography than for (111)In-capromab pendetide single

  10. X-ray-based attenuation correction for positron emission tomography/computed tomography scanners.

    Science.gov (United States)

    Kinahan, Paul E; Hasegawa, Bruce H; Beyer, Thomas

    2003-07-01

    A synergy of positron emission tomography (PET)/computed tomography (CT) scanners is the use of the CT data for x-ray-based attenuation correction of the PET emission data. Current methods of measuring transmission use positron sources, gamma-ray sources, or x-ray sources. Each of the types of transmission scans involves different trade-offs of noise versus bias, with positron transmission scans having the highest noise but lowest bias, whereas x-ray scans have negligible noise but the potential for increased quantitative errors. The use of x-ray-based attenuation correction, however, has other advantages, including a lack of bias introduced from post-injection transmission scanning, which is an important practical consideration for clinical scanners, as well as reduced scan times. The sensitivity of x-ray-based attenuation correction to artifacts and quantitative errors depends on the method of translating the CT image from the effective x-ray energy of approximately 70 keV to attenuation coefficients at the PET energy of 511 keV. These translation methods are usually based on segmentation and/or scaling techniques. Errors in the PET emission image arise from positional mismatches caused by patient motion or respiration differences between the PET and CT scans; incorrect calculation of attenuation coefficients for CT contrast agents or metallic implants; or keeping the patient's arms in the field of view, which leads to truncation and/or beam-hardening (or x-ray scatter) artifacts. Proper interpretation of PET emission images corrected for attenuation by using the CT image relies on an understanding of the potential artifacts. In cases where an artifact or bias is suspected, careful inspection of all three available images (CT and PET emission with and without attenuation correction) is recommended. Copyright 2003 Elsevier Inc. All rights reserved.

  11. Budget impact from the incorporation of positron emission tomography ? computed tomography for staging lung cancers

    OpenAIRE

    Biz, Aline Navega; Caetano, Ros?ngela

    2015-01-01

    OBJECTIVE To estimate the budget impact from the incorporation of positron emission tomography (PET) in mediastinal and distant staging of non-small cell lung cancer.METHODS The estimates were calculated by the epidemiological method for years 2014 to 2018. Nation-wide data were used about the incidence; data on distribution of the disease´s prevalence and on the technologies’ accuracy were from the literature; data regarding involved costs were taken from a micro-costing study and from Brazi...

  12. Positron emission tomography in human hemispheric infarction: a study with 150 continuous inhalation technique

    International Nuclear Information System (INIS)

    Castaigne, Paul; Baron, J.C.; Bousser, M.G.; Comar, D.; Kellershohn, C.; CEA, 91 - Orsay

    1979-01-01

    Non-invasive tomographic imaging of cerebral blood flow and oxygen metabolism has now become possible with the 15 O continuous inhalation technique coupled with positron emission tomography (PET). We have for the first time applied this procedure in a large scale study of human hemispheric infarction. From this study, it may be concluded that: various hitherto undescribed patterns of disturbances in the perfusion/metabolism couple that occur in cerebral infarction have been documented by PET imaging of CBF and EO 2 . The EO 2 appears as an important physiological parameter in the study of recent cerebral infarction, and specific patterns of the CBF/EO 2 relationship are now emerging that may have important pathophysiologic, prognostic and therapeutic implications. Despite some limitations, the non invasive 15 O inhalation technique has a number of major specific advantages that make it particularly suited for the study of ischemic brain disorders

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

    Science.gov (United States)

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

    2013-09-01

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

  14. Is there any role of positron emission tomography computed tomography for predicting resectability of gallbladder cancer?

    Science.gov (United States)

    Kim, Jaihwan; Ryu, Ji Kon; Kim, Chulhan; Paeng, Jin Chul; Kim, Yong-Tae

    2014-05-01

    The role of integrated (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography computed tomography (PET-CT) is uncertain in gallbladder cancer. The aim of this study was to show the role of PET-CT in gallbladder cancer patients. Fifty-three patients with gallbladder cancer underwent preoperative computed tomography (CT) and PET-CT scans. Their medical records were retrospectively reviewed. Twenty-six patients underwent resection. Based on the final outcomes, PET-CT was in good agreement (0.61 to 0.80) with resectability whereas CT was in acceptable agreement (0.41 to 0.60) with resectability. When the diagnostic accuracy of the predictions for resectability was calculated with the ROC curve, the accuracy of PET-CT was higher than that of CT in patients who underwent surgical resection (P=0.03), however, there was no difference with all patients (P=0.12). CT and PET-CT had a discrepancy in assessing curative resection in nine patients. These consisted of two false negative and four false positive CT results (11.3%) and three false negative PET-CT results (5.1%). PET-CT was in good agreement with the final outcomes compared to CT. As a complementary role of PEC-CT to CT, PET-CT tended to show better prediction about resectability than CT, especially due to unexpected distant metastasis.

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

    Science.gov (United States)

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

    2012-06-01

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

  16. Plasma Emission Profile Recreation using Soft X-Ray Tomography

    Science.gov (United States)

    Page, J. W.; Mauel, M. E.; Levesque, J. P.

    2015-11-01

    With sufficient views from multiple diode arrays, soft X-ray tomography is an invaluable plasma diagnostic because it is a non-perturbing method to reconstruct the emission within the interior of the plasma. In preparation for the installation of new SXR arrays in HBT-EP, we compute high-resolution tomographic reconstructions of discharges having kink-like structures that rotate nearly rigidly. By assuming a uniform angular mapping from the kink mode rotation, Δϕ ~ ωΔ t, a temporal sequence from a single 16-diode fan array represents as many as 16 x 100 independent views. We follow the procedure described by Wang and Granetz and use Bessel basis functions to take the inverse Radon transform. This transform is fit to our data using a least-squares method to estimate the internal SXR emissivity as a sum of polar functions. By varying different parameters of the transformation, we optimize the quality of our recreation of the emission profile and quantify how the reconstruction changes with the azimuthal order of the transform. Supported by U.S. DOE Grant DE-FG02-86ER53222.

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

    International Nuclear Information System (INIS)

    Standke, R.

    2002-01-01

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

  18. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-11-01

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

  20. Evaluation of brain tumours by positron emission tomography

    International Nuclear Information System (INIS)

    Schober, O.; Meyer, G.J.

    1992-01-01

    The clinical application of positron emission tomography (PET) for the evaluation of brain tumours has proved clinically valuable. Amino acid and FDG-glucose PET provide information on the degree of malignancy and the prognosis during the initial evaluation. After therapy, the residual tumour can be visualized and recurrence can be differentiated from necrosis. Amino acids have advantages over FDG for these clinical applications. Blood flow, oxygen extraction and metabolism and blood-brain barrier permeability are of minor relevance in clinical situations. Comparison of PET with MRI and MRS will provide new data. The quantitative information of the unique information yielded by PET will lead to a more important clinical role, as will the extrapolation of this experience to the SPECT technique. (orig.) [de

  1. Single photon emission computed tomography of the liver

    International Nuclear Information System (INIS)

    Makler, P.T. Jr.

    1988-01-01

    Single photon emission computed tomography (SPECT) of the liver has been introduced in order to improve sensitivity and localization of space-occupying lesions. There have been numerous reports on the usefulness of the technique, as well as extensive analyses of its technical drawbacks. In general, SPECT provides a more accurate estimation of defect size than does conventional planar scintigraphy for cases in which one wishes to evaluate changes in lesion size due to therapy. The presence of a superimposed parenchymal disease, however, remains a major problem, which will only be resolved by a scanning technique that specifically detects the disease process of concern (hot spot imaging) rather than displacement of normal tissue (cold spot imaging)

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-10-01

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

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

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

    International Nuclear Information System (INIS)

    Pizzichemi, M.

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  7. 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

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

    International Nuclear Information System (INIS)

    Brard, Emmanuel

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    H. Nagasawa

    1993-01-01

    Full Text Available We measured cerebral blood flow, oxygen metabolism, glucose utilization, and dopamine metabolism in the brain of a patient with corticobasal degeneration using positron emission tomography (PET. The clinical picture is distinctive, comprising features referable to both cortical and basal ganglionic dysfunction. Brain imagings of glucose and dopamine metabolism can demonstrate greater abnormalities in the cerebral cortex and in the striatum contralateral to the more affected side than those of blood flow and oxygen metabolism. This unique combination study measuring both cerebral glucose utilization and dopamine metabolism in the nigrostriatal system can provide efficient information about the dysfunctions which are correlated with individual clinical symptoms, and this study is essential to diagnosis of corticobasal degeneration.

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  11. Evaluating patients with ischemic cerebrovascular disease using positron emission tomography

    International Nuclear Information System (INIS)

    Raichle, M.E.

    1982-01-01

    Recent advances in nuclear medicine imaging techniques offer an important alternative for the evaluation of therapy for ischemic cerebrovascular disease. In particular, positron emission tomography (PET), with its capacity to provide quantitative measurements of brain blood flow, metabolism and biochemistry on a truly regional basis, now offers the opportunity to evaluate therapy in terms of specific changes in these parameters. By doing this PET permits one to study the problem on an individual patient basis with each subject serving as his own control. The author has been pursuing this approach in patients considered candidates for superficial temporal artery-middle cerebral artery anastomosis to bypass major stenotic or occlusive lesions of the internal carotid or middle cerebral artery. The results indicate that PET is of considerable value in establishing much more exactly the pathophysiology of certain forms of ischemic cerebrovascular disease and evaluating a form of therapy designed to correct the basic underlying defect. (Auth./C.F.)

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

    International Nuclear Information System (INIS)

    Alexoff, D.L.

    1991-01-01

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

  13. Determination of the attenuation map in emission tomography

    CERN Document Server

    Zaidi, H

    2002-01-01

    Reliable attenuation correction methods for quantitative emission computed tomography (ECT) require accurate delineation of the body contour and often necessitate knowledge of internal anatomical structure. Two broad classes of methods have been used to calculate the attenuation map referred to as "transmissionless" and transmission-based attenuation correction techniques. While calculated attenuation correction belonging to the first class of methods is appropriate for brain studies, more adequate methods must be performed in clinical applications where the attenuation coefficient distribution is not known a priori, and for areas of inhomogeneous attenuation such as the chest. Measured attenuation correction overcomes this problem and utilizes different approaches to determine this map including transmission scanning, segmented magnetic resonance images or appropriately scaled X-ray CT scans acquired either independently on separate or simultaneously on multimodality imaging systems. Combination of data acqu...

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

    International Nuclear Information System (INIS)

    Naagren, Kjell; Halldin, Christer; Rinne, Juha O.

    2010-01-01

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

  15. Brain abnormalities in murderers indicated by positron emission tomography.

    Science.gov (United States)

    Raine, A; Buchsbaum, M; LaCasse, L

    1997-09-15

    Murderers pleading not guilty by reason of insanity (NGRI) are thought to have brain dysfunction, but there have been no previous studies reporting direct measures of both cortical and subcortical brain functioning in this specific group. Positron emission tomography brain imaging using a continuous performance challenge task was conducted on 41 murderers pleading not guilty by reason of insanity and 41 age- and sex-matched controls. Murderers were characterized by reduced glucose metabolism in the prefrontal cortex, superior parietal gyrus, left angular gyrus, and the corpus callosum, while abnormal asymmetries of activity (left hemisphere lower than right) were also found in the amygdala, thalamus, and medial temporal lobe. These preliminary findings provide initial indications of a network of abnormal cortical and subcortical brain processes that may predispose to violence in murderers pleading NGRI.

  16. Investigation of language lateralization mechanism by Positron Emission Tomography

    International Nuclear Information System (INIS)

    Belin, Pascal

    1997-01-01

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

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

    International Nuclear Information System (INIS)

    Gould, K.L.

    1991-01-01

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

  18. F-18-fluorodeoxyglucose-positron-emission tomography in neurology

    International Nuclear Information System (INIS)

    Fazekas, F.; Payer, F.

    2002-01-01

    Positron emission tomography using F-18-fluorodeoxyglucose (F-18-FDG-PET) is an ideal tool for imaging regional cerebral metabolism as glucose is the most important source of energy for neurons. Under physiologic conditions the pattern of metabolism reflects the state of cerebral activation which can be modulated by various stimuli to investigate cerebral organization. Pathologic conditions usually cause a drop in metabolism because of neuronal inactivity or loss. They can, however, also be associated with an increased rate of glucose metabolism such as in case of active epileptic foci or malignant tumors. As a consequence F-18-FDG-PET has become a valuable functional imaging modality especially for the diagnostic clarification of non-contributory or negative morphologic imaging results. Dementia, pre-surgical evaluation of epilepsy and neurooncology are currently frequent indications for referral to F-18-FDG-PET in neurology. (author)

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

    International Nuclear Information System (INIS)

    Kato, Takashi; Fukatsu, Hiroshi; Ito, Kengo; Tadokoro, Masanori; Ota, Toyohiro; Ikeda, Mitsuru; Isomura, Takayuki; Ito, Shigeki; Nishino, Masanari; Ishigaki, Takeo

    1995-01-01

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

  20. Denoising multicriterion iterative reconstruction in emission spectral tomography

    Science.gov (United States)

    Wan, Xiong; Yin, Aihan

    2007-03-01

    In the study of optical testing, the computed tomogaphy technique has been widely adopted to reconstruct three-dimensional distributions of physical parameters of various kinds of fluid fields, such as flame, plasma, etc. In most cases, projection data are often stained by noise due to environmental disturbance, instrumental inaccuracy, and other random interruptions. To improve the reconstruction performance in noisy cases, an algorithm that combines a self-adaptive prefiltering denoising approach (SPDA) with a multicriterion iterative reconstruction (MCIR) is proposed and studied. First, the level of noise is approximately estimated with a frequency domain statistical method. Then the cutoff frequency of a Butterworth low-pass filter was established based on the evaluated noise energy. After the SPDA processing, the MCIR algorithm was adopted for limited-view optical computed tomography reconstruction. Simulated reconstruction of two test phantoms and a flame emission spectral tomography experiment were employed to evaluate the performance of SPDA-MCIR in noisy cases. Comparison with some traditional methods and experiment results showed that the SPDA-MCIR combination had obvious improvement in the case of noisy data reconstructions.

  1. Positron Emission Tomography with Three-Dimensional Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, K.

    1996-10-01

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

  2. Positron Emission Tomography with Three-Dimensional Reconstruction

    International Nuclear Information System (INIS)

    Erlandsson, K.

    1996-10-01

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

  3. Hepatic Pseudolymphoma with Fluorodeoxyglucose Uptake on Positron Emission Tomography

    Directory of Open Access Journals (Sweden)

    Kazuhiro Suzumura

    2017-12-01

    Full Text Available A 69-year-old woman with chronic hepatitis B was admitted to our hospital with a hepatic tumor. The levels of 2 tumor markers, carcinoembryonic antigen and carbohydrate antigen 19-9, were slightly elevated; however, the α-fetoprotein and protein levels induced by vitamin K antagonist II were within the normal limits. Abdominal ultrasonography showed a well-defined peripheral hypoechoic mass that was isoechoic and homogeneous on the inside. Computed tomography showed a poorly enhanced tumor of 13 mm in diameter in the 5th segment of the liver. Fluorodeoxyglucose positron emission tomography showed a slight uptake (maximum standard uptake value 3.4 by the hepatic tumor. These findings suggested cholangiocellular carcinoma, and we performed anterior segmentectomy of the liver. A histopathological examination showed a hepatic pseudolymphoma. The patient’s postoperative course was uneventful, and she remains alive without recurrence 5 months after undergoing surgery. In most cases, hepatic pseudolymphoma is preoperatively diagnosed as a malignant tumor and a definite diagnosis is made after resection. It is therefore necessary to consider hepatic pseudolymphoma as a differential diagnosis in patients with hepatic tumors.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nestle, Ursula; Hentschel, Michael; Grosu, Anca-Ligia [Departments of Radiation Oncology, University of Freiburg, Robert Koch Str. 3, 79106 Freiburg (Germany); Weber, Wolfgang [Nuclear Medicine, University of Freiburg, Robert Koch Str. 3, 79106 Freiburg (Germany)], E-mail: ursula.nestle@uniklinik-freiburg.de

    2009-01-07

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

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

    Science.gov (United States)

    Nestle, Ursula; Weber, Wolfgang; Hentschel, Michael; Grosu, Anca-Ligia

    2009-01-07

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

  6. Quality assurance and radiation safety in positron emission tomography

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  7. Initial characterization of a BGO-photodiode detector for high resolution positron emission tomography

    International Nuclear Information System (INIS)

    Derenzo, S.E.

    1983-11-01

    Spatial resolution in positron emission tomography is currently limited by the resolution of the detectors. This work presents the initial characterization of a detector design using small bismuth germanate (BGO) crystals individually coupled to silicon photodiodes (SPDs) for crystal identification, and coupled in groups to phototubes (PMTs) for coincidence timing. A 3 mm x 3 mm x 3 mm BGO crystal coupled only to an SPD can achieve a 511 keV photopeak resolution of 8.7% FWHM at -150 0 C, using a pulse peaking time of 10 μs. When two 3 mm x 3 mm x 15 mm BGO crystals are coupled individually to SPDs and also coupled to a common 14 mm diam PMT, the SPDs detect the 511 keV photopeak with a resolution of 30% FWHM at -76 0 C. In coincidence with an opposing 3 mm wide BGO crystal, the SPDs are able to identify the crystal of interaction with good signal-to-noise ratio, and the detector pair resolution is 2 mm FWHM. 32 references, 7 figures, 3 tables

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

    International Nuclear Information System (INIS)

    Buck, A.; Kamel, E.

    2002-01-01

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

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  10. Effectiveness of lead aprons in positron emission tomography

    International Nuclear Information System (INIS)

    Bezerra Fonseca, R.; Amaral, A.

    2008-01-01

    Full text: In the last two decades, Positron Emission Tomography (PET) has emerged as clinical diagnostic technique, becoming one of the fastest growing imaging tools in modern nuclear medicine. Because 511 keV annihilation photon energy is much higher than the photon with mean energy of 140 keV emitted in Single Photon Computed Tomography (SPECT), medical staff working in PET studies receive a higher dose than those working only with SPECT tracers do. As a result, special attention must be paid to keep radiation exposure as low as reasonably achievable (ALARA principle). Lead equivalent apron is the principal personal protective equipment for technologists occupationally exposed to ionizing radiation in medical procedures and may be an important component in the ALARA program. However, in practices involving PET, 0.5 mm lead equivalent aprons have been used regardless of photon's energy. In this context, this work was designed for evaluating radioprotective effectiveness of such aprons in PET procedures. For this, the operational quantities personal dose equivalent H p (0.07) and H p (10) have been assessed by using MCNP4C code in a model of individual exposure to small source of 511 keV photons, representing the situation of injection of the radiopharmaceutical, in two situations: technologists wearing and not wearing 0.5 mm lead aprons. To represent the technologist a mathematical anthropomorphic phantom was employed, and the simulated source to subject distances varied between 40 to 100 cm, in steps of 10 cm. The results showed no significant differences between the values obtained for H p (10) in the two situations, pointing out that that there is no radioprotective influence of wearing such aprons on PET practices. Compared to simulations without such device, H p (0.07) increased up about 26% when technologist is wearing radioprotective aprons, depending on the source to subject distance. On the basis of this work, 0.5 mm lead equivalent aprons should not be

  11. Emission tomography with sup(99m)Tc-pyrophosphate in the diagnosis of acute myocardial infarction

    International Nuclear Information System (INIS)

    Poeyhoenen, L.; Uusitalo, A.; Virjo, A.

    1985-01-01

    Electrocardiograms (ECG) and enzyme criteria are usually used to confirm the diagnosis of acute myocardial infarction in the case of chest pain. However, ECG is not always diagnostic. Elevated enzyme values may be due to causes other than myocardial infarction. In uncertain cases, the ECG and enzyme criteria can be supplemented by emission tomography, performed with technetium pyrophosphate that will accumulate in the site of infarction. Twenty-nine patients with suspected acute myocardial infarction were studied with emission tomography. Of these 12 had acute transmural infarction. Both enzyme tests and ECG were diagnostic in only 7 of these 12 cases, 4 had positive enzyme tests but a nondiagnostic ECG and in one case neither enzymes nor ECG were diagnostic. In 11 patients the infarcted myocardial area was detected with emission tomography. Six patients had acute nontransmural infarction. Only 2 of these had positive emission tomography. The chest pain was not due to infarction in 11 patients. All these patients had negative emission tomography. The sensitivity of emission tomography was 92% and specificity 100% in transmural acute infarction. In nontransmural infarction the specificity was only 33%. Emission tomography is a valuable diagnostic tool. It may be the decisive method when ECG and enzymes are not diagnostic. Emissin tomography also shows the localization and size of the infarcted area in the myocardium. (orig.)

  12. Attenuation correction in emission tomography using the emission data—A review

    Energy Technology Data Exchange (ETDEWEB)

    Berker, Yannick, E-mail: berker@mail.med.upenn.edu; Li, Yusheng [Department of Radiology, University of Pennsylvania, 3620 Hamilton Walk, Philadelphia, Pennsylvania 19104 (United States)

    2016-02-15

    The problem of attenuation correction (AC) for quantitative positron emission tomography (PET) had been considered solved to a large extent after the commercial availability of devices combining PET with computed tomography (CT) in 2001; single photon emission computed tomography (SPECT) has seen a similar development. However, stimulated in particular by technical advances toward clinical systems combining PET and magnetic resonance imaging (MRI), research interest in alternative approaches for PET AC has grown substantially in the last years. In this comprehensive literature review, the authors first present theoretical results with relevance to simultaneous reconstruction of attenuation and activity. The authors then look back at the early history of this research area especially in PET; since this history is closely interwoven with that of similar approaches in SPECT, these will also be covered. We then review algorithmic advances in PET, including analytic and iterative algorithms. The analytic approaches are either based on the Helgason–Ludwig data consistency conditions of the Radon transform, or generalizations of John’s partial differential equation; with respect to iterative methods, we discuss maximum likelihood reconstruction of attenuation and activity (MLAA), the maximum likelihood attenuation correction factors (MLACF) algorithm, and their offspring. The description of methods is followed by a structured account of applications for simultaneous reconstruction techniques: this discussion covers organ-specific applications, applications specific to PET/MRI, applications using supplemental transmission information, and motion-aware applications. After briefly summarizing SPECT applications, we consider recent developments using emission data other than unscattered photons. In summary, developments using time-of-flight (TOF) PET emission data for AC have shown promising advances and open a wide range of applications. These techniques may both remedy

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

    International Nuclear Information System (INIS)

    Gundacker, S.

    2014-01-01

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

  14. Spectrum of single photon emission computed tomography/computed tomography findings in patients with parathyroid adenomas.

    Science.gov (United States)

    Chakraborty, Dhritiman; Mittal, Bhagwant Rai; Harisankar, Chidambaram Natrajan Balasubramanian; Bhattacharya, Anish; Bhadada, Sanjay

    2011-01-01

    Primary hyperparathyroidism results from excessive parathyroid hormone secretion. Approximately 85% of all cases of primary hyperparathyroidism are caused by a single parathyroid adenoma; 10-15% of the cases are caused by parathyroid hyperplasia. Parathyroid carcinoma accounts for approximately 3-4% of cases of primary disease. Technetium-99m-sestamibi (MIBI), the current scintigraphic procedure of choice for preoperative parathyroid localization, can be performed in various ways. The "single-isotope, double-phase technique" is based on the fact that MIBI washes out more rapidly from the thyroid than from abnormal parathyroid tissue. However, not all parathyroid lesions retain MIBI and not all thyroid tissue washes out quickly, and subtraction imaging is helpful. Single photon emission computed tomography (SPECT) provides information for localizing parathyroid lesions, differentiating thyroid from parathyroid lesions, and detecting and localizing ectopic parathyroid lesions. Addition of CT with SPECT improves the sensitivity. This pictorial assay demonstrates various SPECT/CT patterns observed in parathyroid scintigraphy.

  15. Detecting Metastatic Bladder Cancer Using (18)F-Fluorodeoxyglucose Positron-Emission Tomography/Computed Tomography.

    Science.gov (United States)

    Öztürk, Hakan

    2015-10-01

    The purpose of this study was to retrospectively investigate the contribution of (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)F-FDG-PET/CT) to detection of metastatic bladder cancer. The present study included 79 patients (69 men and 10 women) undergoing (18)F-FDG-PET/CT upon suspicion of metastatic bladder cancer between July 2007 and April 2013. The mean age was 66.1 years with a standard deviation of 10.7 years (range, 21 to 85 years). Patients were required to fast for 6 hours prior to scanning, and whole-body PET scanning from the skull base to the upper thighs was performed approximately 1 hour after intravenous injection of 555 MBq of (18)F-FDG. Whole body CT scanning was performed in the cranio-caudal direction. FDG-PET images were reconstructed using CT data for attenuation correction. Suspicious recurrent or metastatic lesions were confirmed by histopathology or clinical follow-up. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of (18)F-FDG-PET/CT were 89%, 78%, 90%, 75%, and 86%, respectively. (18)F-FDG-PET/CT can detect metastases with high sensitivity and positive predictive values in patients with metastatic bladder carcinoma.

  16. Brain Positron Emission Tomography-Computed Tomography Gender Differences in Tinnitus Patients.

    Science.gov (United States)

    Shlamkovich, Nathan; Gavriel, Haim; Eviatar, Ephraim; Lorberboym, Mordechay; Aviram, Eliad

    2016-10-01

    Increased metabolism in the left auditory cortex has been reported in tinnitus patients. However, gender difference has not been addressed. To assess the differences in Positron emission tomography-computed tomography (PET-CT) results between the genders in tinnitus patients. Retrospective cohort. Included were patients referred to our clinic between January 2011 and August 2013 who complained of tinnitus and underwent fluorodeoxyglucose (FDG)-PET to assess brain metabolism. Univariate and multivariate nominal logistic regressions were used to evaluate the association between upper temporal gyrus (UTG; right and left) and gender. Included were 140 patients (87 males) with an average age of 52.5 yr (median = 53.1). Bilateral tinnitus was found in 85 patients (60.7%), left sided in 30 (21.4%), and right sided in 21(15%). Increased uptake in the UTG was found in 60% of the patients on either side. Males had a statistically significant increased uptake in the UTG in those with unilateral tinnitus and in the entire population. We present the largest study reported so far on tinnitus patients who have undergone FDG-PET-CT. We found a statistically significant difference between the genders in FDG uptake by the UTG. Further investigations should be undertaken to reveal the etiologies for these differences and to assess different therapeutic protocols according to gender. American Academy of Audiology

  17. Use of Positron Emission Tomography/Computed Tomography in Radiation Treatment Planning for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Kezban Berberoğlu

    2016-06-01

    Full Text Available Radiotherapy (RT plays an important role in the treatment of lung cancer. Accurate diagnosis and staging are crucial in the delivery of RT with curative intent. Target miss can be prevented by accurate determination of tumor contours during RT planning. Currently, tumor contours are determined manually by computed tomography (CT during RT planning. This method leads to differences in delineation of tumor volume between users. Given the change in RT tools and methods due to rapidly developing technology, it is now more significant to accurately delineate the tumor tissue. F18 fluorodeoxyglucose positron emission tomography/CT (F18 FDG PET/CT has been established as an accurate method in correctly staging and detecting tumor dissemination in lung cancer. Since it provides both anatomic and biologic information, F18 FDG PET decreases interuser variability in tumor delineation. For instance, tumor volumes may be decreased as atelectasis and malignant tissue can be more accurately differentiated, as well as better evaluation of benign and malignant lymph nodes given the difference in FDG uptake. Using F18 FDG PET/CT, the radiation dose can be escalated without serious adverse effects in lung cancer. In this study, we evaluated the contribution of F18 FDG PET/CT for RT planning in lung cancer.

  18. 18F-FDG positron emission tomography/computed tomography in infective endocarditis.

    Science.gov (United States)

    Salomäki, Soile Pauliina; Saraste, Antti; Kemppainen, Jukka; Bax, Jeroen J; Knuuti, Juhani; Nuutila, Pirjo; Seppänen, Marko; Roivainen, Anne; Airaksinen, Juhani; Pirilä, Laura; Oksi, Jarmo; Hohenthal, Ulla

    2017-02-01

    The diagnosis of infective endocarditis (IE), especially the diagnosis of prosthetic valve endocarditis (PVE) is challenging since echocardiographic findings are often scarce in the early phase of the disease. We studied the use of 2-[ 18 F]fluoro-2-deoxy-D-glucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) in IE. Sixteen patients with suspected PVE and 7 patients with NVE underwent visual evaluation of 18 F-FDG-PET/CT. 18 F-FDG uptake was measured also semiquantitatively as maximum standardized uptake value (SUV max ) and target-to-background ratio (TBR). The modified Duke criteria were used as a reference. There was strong, focal 18 F-FDG uptake in the area of the affected valve in all 6 cases of definite PVE, in 3 of 5 possible PVE cases, and in 2 of 5 rejected cases. In all patients with definite PVE, SUV max of the affected valve was higher than 4 and TBR higher than 1.8. In contrast to PVE, only 1 of 7 patients with NVE had uptake of 18 F-FDG by PET/CT in the valve area. Embolic infectious foci were detected in 58% of the patients with definite IE. 18 F-FDG-PET/CT appears to be a sensitive method for the detection of paravalvular infection associated with PVE. Instead, the sensitivity of PET/CT is limited in NVE.

  19. Mycosis fungoides: Positron emission tomography/computed tomography in staging and monitoring the effect of therapy

    International Nuclear Information System (INIS)

    D’Souza, Maria Mathew; D’Souza, Paschal; Sharma, Rajnish; Jaimini, Abhinav; Mondal, Anupam

    2015-01-01

    A 58-year-old woman, diagnosed as a case of mycosis fungoides (MF), underwent [18F]-fluoro-D-glucose positron emission tomography/computed tomography (FDG PET/CT) examination. The study revealed intense FDG uptake in a large ulceroproliferative right thigh lesion, indurated plaques in the chest wall and left thigh, along with multiple sites of cutaneous involvement, axillary and inguinal lymphadenopathy. The patient underwent chemotherapy with CHOP regimen, radiotherapy for the right thigh lesion, along with topical corticosteroids and emollients for the disseminated cutaneous involvement. Repeat [18F]-FDG PET/CT study performed a year later, showed near complete disease regression specifically of the ulceroproliferative lesion and indurated cutaneous plaques, no change in lymphadenopathy, and a subtle diffuse progression of the remaining cutaneous lesions. A multidisciplinary approach to the diagnosis, staging and treatment of MF has long been suggested for optimizing outcomes from management of patients with this disease. This case highlights the potential role of incorporating PET/CT as a single modality imaging technique in the staging and assessment of response to therapy

  20. Technical aspects of positron emission tomography/computed tomography in radiotherapy treatment planning.

    Science.gov (United States)

    Scripes, Paola G; Yaparpalvi, Ravindra

    2012-09-01

    The usage of functional data in radiation therapy (RT) treatment planning (RTP) process is currently the focus of significant technical, scientific, and clinical development. Positron emission tomography (PET) using ((18)F) fluorodeoxyglucose is being increasingly used in RT planning in recent years. Fluorodeoxyglucose is the most commonly used radiotracer for diagnosis, staging, recurrent disease detection, and monitoring of tumor response to therapy (Lung Cancer 2012;76:344-349; Lung Cancer 2009;64:301-307; J Nucl Med 2008;49:532-540; J Nucl Med 2007;48:58S-67S). All the efforts to improve both PET and computed tomography (CT) image quality and, consequently, lesion detectability have a common objective to increase the accuracy in functional imaging and thus of coregistration into RT planning systems. In radiotherapy, improvement in target localization permits reduction of tumor margins, consequently reducing volume of normal tissue irradiated. Furthermore, smaller treated target volumes create the possibility of dose escalation, leading to increased chances of tumor cure and control. This article focuses on the technical aspects of PET/CT image acquisition, fusion, usage, and impact on the physics of RTP. The authors review the basic elements of RTP, modern radiation delivery, and the technical parameters of coregistration of PET/CT into RT computerized planning systems. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. A novel phantom design for emission tomography enabling scatter- and attenuation-''free'' single-photon emission tomography imaging

    International Nuclear Information System (INIS)

    Larsson, S.A.; Johansson, L.; Jonsson, C.; Pagani, M.; Jacobsson, H.

    2000-01-01

    A newly designed technique for experimental single-photon emission tomography (SPET) and positron emission tomography (PET) data acquisition with minor disturbing effects from scatter and attenuation has been developed. In principle, the method is based on discrete sampling of the radioactivity distribution in 3D objects by means of equidistant 2D planes. The starting point is a set of digitised 2D sections representing the radioactivity distribution of the 3D object. Having a radioactivity-related grey scale, the 2D images are printed on paper sheets using radioactive ink. The radioactive sheets can be shaped to the outline of the object and stacked into a 3D structure with air or some arbitrary dense material in between. For this work, equidistantly spaced transverse images of a uniform cylindrical phantom and of the digitised Hoffman rCBF phantom were selected and printed out on paper sheets. The uniform radioactivity sheets were imaged on the surface of a low-energy ultra-high-resolution collimator (4 mm full-width at half-maximum) of a three-headed SPET camera. The reproducibility was 0.7% and the uniformity was 1.2%. Each rCBF sheet, containing between 8.3 and 80 MBq of 99m TcO 4 - depending on size, was first imaged on the collimator and then stacked into a 3D structure with constant 12 mm air spacing between the slices. SPET was performed with the sheets perpendicular to the central axis of the camera. The total weight of the stacked rCBF phantom in air was 63 g, giving a scatter contribution comparable to that of a point source in air. The overall attenuation losses were <20%. A second SPET study was performed with 12-mm polystyrene plates in between the radioactive sheets. With polystyrene plates, the total phantom weight was 2300 g, giving a scatter and attenuation magnitude similar to that of a patient study. With the proposed technique, it is possible to obtain ''ideal'' experimental images (essentially built up by primary photons) for comparison with

  2. Single-photon emission computed tomography/computed tomography in lung cancer and malignant lymphoma.

    Science.gov (United States)

    Schillaci, Orazio

    2006-10-01

    In nuclear oncology, despite the fast-growing diffusion of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET), single-photon emission computed tomography (SPECT) studies can still play an useful clinical role in several applications. The main limitation of SPECT imaging with tumor-seeking agents is the lack of the structural delineation of the pathologic processes they detect; this drawback sometimes renders SPECT interpretation difficult and can diminish its diagnostic accuracy. Fusion with morphological studies can overcome this limitation by giving an anatomical map to scintigraphic data. In the past, software-based fusion of independently performed SPECT and CT images proved to be time-consuming and impractical for routine use. The recent development of dual-modality integrated imaging systems that provide functional (SPECT) and anatomical (CT) images in the same scanning session, with the acquired images coregistered by means of the hardware, has opened a new era in this field. The first reports indicate that SPECT/CT is very useful in cancer imaging because it is able to provide further information of clinical value in several cases. In SPECT, studies of lung cancer and malignant lymphomas using different radiopharmaceutical, hybrid images are of value in providing the correct localization of tumor sites, with a precise detection of the involved organs, and the definition of their functional status, and in allowing the exclusion of disease in sites of physiologic tracer uptake. Therefore, in lung cancer and lymphomas, hybrid SPECT/CT can play a role in the diagnosis of the primary tumor, in the staging of the disease, in the follow-up, in the monitoring of therapy, in the detection of recurrence, and in dosimetric estimations for target radionuclide therapy.

  3. Emission Spectrum Property of Modulated Atom-Field Coupling System

    International Nuclear Information System (INIS)

    Gao Yun-Feng; Feng Jian; Li Yue-Ke

    2013-01-01

    The emission spectrum of a two-level atom interacting with a single mode radiation field in the case of periodic oscillation coupling coefficient is investigated. A general expression for the emission spectrum is derived. The numerical results for the initial field in pure number stare are calculated. It is found that the effect of the coupling coefficient modulation on the spectral structure is very obvious in the case of a low modulation frequency and larger amplitude when the initial field is vacuum, which is potentially useful for exploring a modulated light source. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  4. Retroperitoneal Endometriosis: A Possible Cause of False Positive Finding at 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

    International Nuclear Information System (INIS)

    Maffione, Anna Margherita; Panzavolta, Riccardo; Lisato, Laura Camilla; Ballotta, Maria; D'Isanto, Mariangela Zanforlini; Rubello, Domenico

    2015-01-01

    Endometriosis is a frequent and clinically relevant problem in young women. Laparoscopy is still the gold standard for the diagnosis of endometriosis, but frequently both morphologic and functional imaging techniques are involved in the diagnostic course before achieving a conclusive diagnosis. We present a case of a patient affected by infiltrating retroperitoneal endometriosis falsely interpreted as a malignant mass by contrast-enhanced magnetic resonance imaging and 18 F-fluorodeoxyglucose positron emission tomography/computed tomography

  5. Utility of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in a child with chronic granulomatous disease

    International Nuclear Information System (INIS)

    Garg, Gunjan; DaSilva, Raphaella; Bhalakia, Avni; Milstein, David M.

    2016-01-01

    We report the fluorodeoxyglucose positron emission tomography/computed tomography (FDG - PET/CT) findings in an 11-month-old boy with suspected milk protein allergy, presented to the hospital with 2-month history of fever of unknown origin and failure to thrive. It showed FDG avid lymphadenopathy above and below the diaphragm and splenic focus, which could represent diffuse inflammatory process or lymphoma. Subsequent jejunal biopsy showed non-necrotizing granulomas

  6. Head and neck: normal variations and benign findings in FDG positron emission tomography/computed tomography imaging.

    Science.gov (United States)

    Højgaard, Liselotte; Berthelsen, Anne Kiil; Loft, Annika

    2014-04-01

    Positron emission tomography (PET)/computed tomography with FDG of the head and neck region is mainly used for the diagnosis of head and neck cancer, for staging, treatment evaluation, relapse, and planning of surgery and radio therapy. This article is a practical guide of imaging techniques, including a detailed protocol for FDG PET in head and neck imaging, physiologic findings, and pitfalls in selected case stories. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. EEG, transmission computed tomography, and positron emission tomography with fluorodeoxyglucose 18F. Their use in adults with gliomas

    International Nuclear Information System (INIS)

    Newmark, M.E.; Theodore, W.H.; Sato, S.; De La Paz, R.; Patronas, N.; Brooks, R.; Jabbari, B.; Di Chiro, G.

    1983-01-01

    We evaluated the relationship between findings from EEG, transmission computed tomography (CT), and positron emission tomography in 23 adults with gliomas. The cortical metabolic rate was suppressed in patients with and without focal slowing. Focal delta activity was not related to involvement of gray or white matter. Rhythmic delta activity and focal attenuation of background amplitude on EEG, however, were correlated with involvement of the thalamus

  8. 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

  9. Promising role of single photon emission computed tomography/computed tomography in Meckel's scan

    International Nuclear Information System (INIS)

    Jain, Anurag; Chauhan, MS; Pandit, AG; Kumar, Rajeev; Sharma, Amit

    2012-01-01

    Meckel's scan is a common procedure performed in nuclear medicine. Single-photon emission computed tomography/computed tomography (SPECT/CT) in a suspected case of heterotopic location of gastric mucosa can increase the accuracy of its anatomic localization. We present two suspected cases of Meckel's diverticulum in, which SPECT/CT co-registration has helped in better localization of the pathology

  10. In Vivo Treatment Sensitivity Testing With Positron Emission Tomography/Computed Tomography After One Cycle of Chemotherapy for Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    Hutchings, Martin; Kostakoglu, Lale; Zaucha, Jan Maciej

    2014-01-01

    PURPOSE: Negative [(18)F]fluorodeoxyglucose (FDG) -positron emission tomography (PET)/computed tomography (CT) after two cycles of chemotherapy indicates a favorable prognosis in Hodgkin lymphoma (HL). We hypothesized that the negative predictive value would be even higher in patients responding....... In the absence of precise pretherapeutic predictive markers, PET1 is the best method for response-adapted strategies designed to select patients for less intensive treatment....

  11. Trails on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Leading to Diagnosis of Testicular Adrenal Rest Tumor.

    Science.gov (United States)

    Kashyap, Raghava

    2018-01-01

    Testicular adrenal rest tumors (TARTs) are secondary to hypertrophy of adrenal rest cells in the rete testis in settings of hypersecretion of androgens. We present a case of congenital adrenal hyperplasia with TART with clues to the diagnosis on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT). To the best of our knowledge, this is the first reported case on the role of 18 F-FDG PET/CT in TART.

  12. 18F-fluorodeoxyglucose positron emission tomography in uterine carcinosarcoma

    International Nuclear Information System (INIS)

    Ho, Kung-Chu; Yen, Tzu-Chen; Lai, Chyong-Huey; Wu, Tzu-I; Chang, Ting-Chang; Huang, Huei-Jean; Ng, Koon-Kwan; Lin, Gigin; Wang, Chun-Chieh; Hsueh, Swei

    2008-01-01

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

  13. Fluorodeoxyglucose positron emission tomography in pulmonary carcinoid tumors

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Everitt, C.; Leong, T.

    2006-01-01

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

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

    Science.gov (United States)

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

    2014-01-13

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

  16. 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)

  17. 18 F-fluorodeoxyglucose positron emission tomography-computed tomography for preoperative lymph node staging in patients undergoing radical cystectomy for bladder cancer: a prospective study.

    Science.gov (United States)

    Hitier-Berthault, Maryam; Ansquer, Catherine; Branchereau, Julien; Renaudin, Karine; Bodere, Françoise; Bouchot, Olivier; Rigaud, Jérôme

    2013-08-01

    The objective of our study was to analyze the diagnostic performance of (18) F-fluorodeoxyglucose positron emission tomography-computed tomography for lymph node staging in patients with bladder cancer before radical cystectomy and to compare it with that of computed tomography. A total of 52 patients operated on between 2005 and 2010 were prospectively included in this prospective, mono-institutional, open, non-randomized pilot study. Patients who had received neoadjuvant chemotherapy or radiotherapy were excluded. (18) F-fluorodeoxyglucose positron emission tomography-computed tomography in addition to computed tomography was carried out for lymph node staging of bladder cancer before radical cystectomy. Lymph node dissection during radical cystectomy was carried out. Findings from (18) F-fluorodeoxyglucose positron emission tomography-computed tomography and computed tomography were compared with the results of definitive histological examination of the lymph node dissection. The diagnostic performance of the two imaging modalities was assessed and compared. The mean number of lymph nodes removed during lymph node dissection was 16.5 ± 10.9. Lymph node metastasis was confirmed on histological examination in 22 cases (42.3%). This had been suspected in five cases (9.6%) on computed tomography and in 12 cases (23.1%) on (18) F-fluorodeoxyglucose positron emission tomography-computed tomography. Sensitivity, specificity, positive predictive value, negative predictive value, relative risk and accuracy were 9.1%, 90%, 40%, 57.4%, 0.91 and 55.7%, respectively, for computed tomography, and 36.4%, 86.7%, 66.7%, 65%, 2.72, 65.4%, respectively, for (18) F-fluorodeoxyglucose positron emission tomography-computed tomography. (18) F-fluorodeoxyglucose positron emission tomography-computed tomography is more reliable than computed tomography for preoperative lymph node staging in patients with invasive bladder carcinoma undergoing radical cystectomy. © 2012 The Japanese

  18. Contribution of positron emission tomography to physiopathological study of cerebral ischemia in man

    Energy Technology Data Exchange (ETDEWEB)

    Baron, J C; Bousser, M G; Comar, D; Rougemont, D; Lebrun-Grandie, P [Commissariat a l' Energie Atomique, Centre Hospitalier Frederic Joliot, 91 - Orsay (France); Castaigne, P [Hopital de la Salpetriere, 75 - Paris (France)

    1983-12-29

    The development of positron emission tomography now allows the local study of cerebral blood flow, oxygen consumption and glucose utilization in ischemic stroke patients. In recent cerebral infarction, a disruption of the normal couple between flow and metabolism is almost constantly observed: in the first few days cerebral blood flow is either inadequate (persistant ischemia) or over-abundant (''luxury perfusion''), whereas a late ''luxury perfusion'' is almost constant within the necrotic area between the 10th and the 40th day. Threshold values for cerebral blood flow and oxygen consumption that are ultimately associated with necrosis or tissue integrity have been determined. A metabolic depression without C.T. Scan counterpart has been observed in various brain structures remote from the infarcted area per se. Lastly, the hemodynamic and metabolic effects of superficial-temporal-middle-cerebral-artery anastomosis have been studied.

  19. Quantified measurement of brain blood volume: comparative evaluations between the single photon emission computer tomography and the positron computer tomography

    International Nuclear Information System (INIS)

    Bouvard, G.; Fernandez, Y.; Petit-Taboue, M.C.; Derlon, J.M.; Travere, J.M.; Le Poec, C.

    1991-01-01

    The quantified measurement of cerebral blood volume is interesting for the brain blood circulation studies. This measurement is often used in positron computed tomography. It's more difficult in single photon emission computed tomography: there are physical problems with the limited resolution of the detector, the Compton effect and the photon attenuation. The objectif of this study is to compare the results between these two techniques. The quantified measurement of brain blood volume is possible with the single photon emission computer tomogragry. However, there is a loss of contrast [fr

  20. Fluorinated tracers for imaging cancer with positron emission tomography

    International Nuclear Information System (INIS)

    Couturier, Olivier; Chatal, Jean-Francois; Luxen, Andre; Vuillez, Jean-Philippe; Rigo, Pierre; Hustinx, Roland

    2004-01-01

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

  1. 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

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

    International Nuclear Information System (INIS)

    Herscovitch, P.; Powers, W.J.

    1987-01-01

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

  3. 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.)

  4. European health telematics networks for positron emission tomography

    Science.gov (United States)

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

    2006-12-01

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

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

    CERN Document Server

    Powolny, François

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

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

    International Nuclear Information System (INIS)

    Sureau, F.

    2008-06-01

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

  7. Positron emission tomography scans on kanji and kana

    International Nuclear Information System (INIS)

    Sakurai, Yasuhisa

    2002-01-01

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

  8. Brain single photon emission computed tomography in neonates

    International Nuclear Information System (INIS)

    Denays, R.; Van Pachterbeke, T.; Tondeur, M.

    1989-01-01

    This study was designed to rate the clinical value of [ 123 I]iodoamphetamine (IMP) or [ 99m Tc] hexamethyl propylene amine oxyme (HM-PAO) brain single photon emission computed tomography (SPECT) in neonates, especially in those likely to develop cerebral palsy. The results showed that SPECT abnormalities were congruent in most cases with structural lesions demonstrated by ultrasonography. However, mild bilateral ventricular dilatation and bilateral subependymal porencephalic cysts diagnosed by ultrasound were not associated with an abnormal SPECT finding. In contrast, some cortical periventricular and sylvian lesions and all the parasagittal lesions well visualized in SPECT studies were not diagnosed by ultrasound scans. In neonates with subependymal and/or intraventricular hemorrhage the existence of a parenchymal abnormality was only diagnosed by SPECT. These results indicate that [ 123 I]IMP or [ 99m Tc]HM-PAO brain SPECT shows a potential clinical value as the neurodevelopmental outcome is clearly related to the site, the extent, and the number of cerebral lesions. Long-term clinical follow-up is, however, mandatory in order to define which SPECT abnormality is associated with neurologic deficit

  9. Automated identification of the lung contours in positron emission tomography

    International Nuclear Information System (INIS)

    Nery, F; Ferreira, N C; Faustino, R; Silva, J Silvestre; Caramelo, F J

    2013-01-01

    Positron Emission Tomography (PET) is a nuclear medicine imaging technique that permits to analyze, in three dimensions, the physiological processes in vivo. One of the areas where PET has demonstrated its advantages is in the staging of lung cancer, where it offers better sensitivity and specificity than other techniques such as CT. On the other hand, accurate segmentation, an important procedure for Computer Aided Diagnostics (CAD) and automated image analysis, is a challenging task given the low spatial resolution and the high noise that are intrinsic characteristics of PET images. This work presents an algorithm for the segmentation of lungs in PET images, to be used in CAD and group analysis in a large patient database. The lung boundaries are automatically extracted from a PET volume through the application of a marker-driven watershed segmentation procedure which is robust to the noise. In order to test the effectiveness of the proposed method, we compared the segmentation results in several slices using our approach with the results obtained from manual delineation. The manual delineation was performed by nuclear medicine physicians that used a software routine that we developed specifically for this task. To quantify the similarity between the contours obtained from the two methods, we used figures of merit based on region and also on contour definitions. Results show that the performance of the algorithm was similar to the performance of human physicians. Additionally, we found that the algorithm-physician agreement is similar (statistically significant) to the inter-physician agreement.

  10. Application of positron emission tomography in the lung

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  11. Application of ART to time-coded emission tomography

    International Nuclear Information System (INIS)

    Koral, K.F.; Rogers, W.L.

    1979-01-01

    Devices for single-photon emission tomography currently take projections either in a plane over a full angular range (0-360 0 ) or in a volume with a limited angular range. The planar, pseudo-random, time-coded aperture, in conjunction with an Anger camera, is a device of the limited angular range type. It employs multiple pinholes whose transmission varies as a function of time. Previously, image reconstruction was accomplished by simple back-projection of coefficients obtained by time-correlating pinhole transmission with detector-element count rate, resulting in a low-contrast image. Using the Algebraic Reconstruction Technique (ART) a method is introduced for division of the correlation coefficients into subsets allowing the three-dimensional reconstruction to be accomplished on a minicomputer. Results from simulations and experimental phantom data show that ART improves depth resolution compared to back-projection, that under-relaxation produces better images in the case of noisy data, and that the division of the correlation coefficients into subsets has no effect on quality. The images depict the expected resolution degradation in the direction normal to the detector plane due to the limited angular range of projections but yield quantitative results whose relative values are good, even though attenuation is neglected. (author)

  12. Simultaneous in vivo positron emission tomography and magnetic resonance imaging.

    Science.gov (United States)

    Catana, Ciprian; Procissi, Daniel; Wu, Yibao; Judenhofer, Martin S; Qi, Jinyi; Pichler, Bernd J; Jacobs, Russell E; Cherry, Simon R

    2008-03-11

    Positron emission tomography (PET) and magnetic resonance imaging (MRI) are widely used in vivo imaging technologies with both clinical and biomedical research applications. The strengths of MRI include high-resolution, high-contrast morphologic imaging of soft tissues; the ability to image physiologic parameters such as diffusion and changes in oxygenation level resulting from neuronal stimulation; and the measurement of metabolites using chemical shift imaging. PET images the distribution of biologically targeted radiotracers with high sensitivity, but images generally lack anatomic context and are of lower spatial resolution. Integration of these technologies permits the acquisition of temporally correlated data showing the distribution of PET radiotracers and MRI contrast agents or MR-detectable metabolites, with registration to the underlying anatomy. An MRI-compatible PET scanner has been built for biomedical research applications that allows data from both modalities to be acquired simultaneously. Experiments demonstrate no effect of the MRI system on the spatial resolution of the PET system and <10% reduction in the fraction of radioactive decay events detected by the PET scanner inside the MRI. The signal-to-noise ratio and uniformity of the MR images, with the exception of one particular pulse sequence, were little affected by the presence of the PET scanner. In vivo simultaneous PET and MRI studies were performed in mice. Proof-of-principle in vivo MR spectroscopy and functional MRI experiments were also demonstrated with the combined scanner.

  13. Quantifying the limitations of small animal positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Oxley, D.C. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom)], E-mail: dco@ns.ph.liv.ac.uk; Boston, A.J.; Boston, H.C.; Cooper, R.J.; Cresswell, J.R.; Grint, A.N.; Nolan, P.J.; Scraggs, D.P. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lazarus, I.H. [STFC Daresbury Laboratory, Warrington, WA4 4AD Cheshire (United Kingdom); Beveridge, T.E. [School of Materials and Engineering, Monash University, Melbourne (Australia)

    2009-06-01

    The application of position sensitive semiconductor detectors in medical imaging is a field of global research interest. The Monte-Carlo simulation toolkit GEANT4 [ (http://geant4.web.cern.ch/geant4/)] was employed to improve the understanding of detailed {gamma}-ray interactions within the small animal Positron Emission Tomography (PET), high-purity germanium (HPGe) imaging system, SmartPET [A.J. Boston, et al., Oral contribution, ANL, Chicago, USA, 2006]. This system has shown promising results in the field of PET [R.J. Cooper, et al., Nucl. Instr. and Meth. A (2009), accepted for publication] and Compton camera imaging [J.E. Gillam, et al., Nucl. Instr. and Meth. A 579 (2007) 76]. Images for a selection of single and multiple point, line and phantom sources were successfully reconstructed using both a filtered-back-projection (FBP) [A.R. Mather, Ph.D. Thesis, University of Liverpool, 2007] and an iterative reconstruction algorithm [A.R. Mather, Ph.D. Thesis, University of Liverpool, 2007]. Simulated data were exploited as an alternative route to a reconstructed image allowing full quantification of the image distortions introduced in each phase of the data processing. Quantifying the contribution of uncertainty in all system components from detector to reconstruction algorithm allows the areas in need of most attention on the SmartPET project and semiconductor PET to be addressed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Karbe, H; Holthoff, V; Huber, M; Herholz, K; Wienhard, K; Wagner, R; Heiss, W D [Universitaetsklinik fuer Neurologie und Max-Planck-Institut fuer neurologische Forschung, Koeln (Germany)

    1992-01-01

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

  15. Respiratory synchronization for lung tumors exploration by positon emission tomography

    International Nuclear Information System (INIS)

    Grotus, Nicolas

    2009-01-01

    Positron Emission Tomography (PET) is a medical imaging technique that requires several minutes of acquisition to get an image. PET images are thus severely affected by the respiratory motion of the patient, which introduces a blur in the images. Techniques consisting in gating the PET acquisition as a function of the patient respiration exist and reduce the respiratory blur in the PET images. However, these techniques increase the noise in the reconstructed images. The aim of this work was to propose a method for respiratory motion compensation that would not enhance the noise in the PET images, without increasing the acquisition duration nor estimating the deformation field associated with the respiratory motion. We proposed 2 original spatio-temporal (4D) reconstruction algorithms of gated PET images. These 2 methods take advantage of the temporal correlation between the images corresponding to the different breathing phases. The performances of these techniques were evaluated and compared to classic approaches using phantom data and simulated data. The results showed that the 4D reconstructions increase the signal-to-noise ratio compared to the classic reconstructions while maintaining the reduction of the respiratory blur. For a fixed acquisition duration, the 4D reconstructions can thus yield gated images that are almost free of respiratory blur and of the same quality in terms of noise level as the ones obtained without respiratory gating. The clinical feasibility of the proposed techniques was also demonstrated. (author) [fr

  16. Imaging Cellular Proliferation in Prostate Cancer with Positron Emission Tomography

    Directory of Open Access Journals (Sweden)

    Hossein Jadvar

    2015-07-01

    Full Text Available Prostate cancer remains a major public health problem worldwide. Imaging plays an important role in the assessment of disease at all its clinical phases, including staging, restaging after definitive therapy, evaluation of therapy response, and prognostication. Positron emission tomography with a number of biologically targeted radiotracers has been demonstrated to have potential diagnostic and prognostic utility in the various clinical phases of this prevalent disease. Given the remarkable biological heterogeneity of prostate cancer, one major unmet clinical need that remains is the non-invasive imaging-based characterization of prostate tumors. Accurate tumor characterization allows for image-targeted biopsy and focal therapy as well as facilitates objective assessment of therapy effect. PET in conjunction with radiotracers that track the thymidine salvage pathway of DNA synthesis may be helpful to fulfill this necessity. We review briefly the preclinical and pilot clinical experience with the two major cellular proliferation radiotracers, [18F]-3’-deoxy-3’-fluorothymidine and [18F]-2’-fluoro-5-methyl-1-beta-D-arabinofuranosyluracil in prostate cancer.

  17. Iterative concurrent reconstruction algorithms for emission computed tomography

    International Nuclear Information System (INIS)

    Brown, J.K.; Hasegawa, B.H.; Lang, T.F.

    1994-01-01

    Direct reconstruction techniques, such as those based on filtered backprojection, are typically used for emission computed tomography (ECT), even though it has been argued that iterative reconstruction methods may produce better clinical images. The major disadvantage of iterative reconstruction algorithms, and a significant reason for their lack of clinical acceptance, is their computational burden. We outline a new class of ''concurrent'' iterative reconstruction techniques for ECT in which the reconstruction process is reorganized such that a significant fraction of the computational processing occurs concurrently with the acquisition of ECT projection data. These new algorithms use the 10-30 min required for acquisition of a typical SPECT scan to iteratively process the available projection data, significantly reducing the requirements for post-acquisition processing. These algorithms are tested on SPECT projection data from a Hoffman brain phantom acquired with a 2 x 10 5 counts in 64 views each having 64 projections. The SPECT images are reconstructed as 64 x 64 tomograms, starting with six angular views. Other angular views are added to the reconstruction process sequentially, in a manner that reflects their availability for a typical acquisition protocol. The results suggest that if T s of concurrent processing are used, the reconstruction processing time required after completion of the data acquisition can be reduced by at least 1/3 T s. (Author)

  18. Carbon-11-methionine positron emission tomography imaging of chordoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong [Department of Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Department of Medical Imaging, Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, 263-8555, Chiba (Japan); Yoshikawa, Kyosan; Tamura, Katsumi; Sagou, Kenji; Kandatsu, Susumu [Clinical Diagnosis Section, National Institute of Radiological Sciences, Chiba (Japan); Tian, Mei; Suhara, Tetsuya; Suzuki, Kazutoshi; Tanada, Shuji [Department of Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Tsujii, Hirohiko [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan)

    2004-09-01

    Chordoma is a rare malignant bone tumor that arises from notochord remnants. This is the first trial to investigate the utility of {sup 11}C-methionine (MET) positron emission tomography (PET) in the imaging of chordoma before and after carbon-ion radiotherapy (CIRT). Fifteen patients with chordoma were investigated with MET-PET before and after CIRT and the findings analyzed visually and quantitatively. Tumor MET uptake was evaluated by tumor-to-nontumor ratio (T/N ratio). In 12 (80%) patients chordoma was clearly visible in the baseline MET-PET study with a mean T/N ratio of 3.3{+-}1.7. The MET uptake decreased significantly to 2.3{+-}1.4 after CIRT (P<0.05). A significant reduction in tumor MET uptake of 24% was observed after CIRT. Fourteen (93%) patients showed no local recurrence after CIRT with a median follow-up time of 20 months. This study has demonstrated that MET-PET is feasible for imaging of chordoma. MET-PET could provide important tumor metabolic information for the therapeutic monitoring of chordoma after CIRT. (orig.)

  19. Carbon-11-methionine positron emission tomography imaging of chordoma

    International Nuclear Information System (INIS)

    Zhang, Hong; Yoshikawa, Kyosan; Tamura, Katsumi; Sagou, Kenji; Kandatsu, Susumu; Tian, Mei; Suhara, Tetsuya; Suzuki, Kazutoshi; Tanada, Shuji; Tsujii, Hirohiko

    2004-01-01

    Chordoma is a rare malignant bone tumor that arises from notochord remnants. This is the first trial to investigate the utility of 11 C-methionine (MET) positron emission tomography (PET) in the imaging of chordoma before and after carbon-ion radiotherapy (CIRT). Fifteen patients with chordoma were investigated with MET-PET before and after CIRT and the findings analyzed visually and quantitatively. Tumor MET uptake was evaluated by tumor-to-nontumor ratio (T/N ratio). In 12 (80%) patients chordoma was clearly visible in the baseline MET-PET study with a mean T/N ratio of 3.3±1.7. The MET uptake decreased significantly to 2.3±1.4 after CIRT (P<0.05). A significant reduction in tumor MET uptake of 24% was observed after CIRT. Fourteen (93%) patients showed no local recurrence after CIRT with a median follow-up time of 20 months. This study has demonstrated that MET-PET is feasible for imaging of chordoma. MET-PET could provide important tumor metabolic information for the therapeutic monitoring of chordoma after CIRT. (orig.)

  20. 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

  1. European health telematics networks for positron emission tomography

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    International Nuclear Information System (INIS)

    Tang Ganghua; Wu Guangyuan

    2007-01-01

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

  3. 67Ga-emission computed tomography in bronchogenic carcinoma

    International Nuclear Information System (INIS)

    Ichiya, Yuichi; Oshiumi, Yoshihiko; Kuwabara, Yasuo; Wada, Makoto; Ayabe, Zenji; Matsuura, Keiichi

    1982-01-01

    Both conventional 67 Ga scintigraphy and 67 Ga emission computed tomography (ECT) were performed in 36 patients with bronchogenic carcinoma to evaluate clinical significance of 67 Ga-ECT as an adjunctive method. Each patient received 111 -- 185 MBq (3 -- 5 mCi) of 67 Ga-citrate intravenously. A rotation #betta# camera (Shimadzu LFOV-E) was used for ECT study, and a #betta# camera (Searle LFOV) was used for conventional scintigraphy. The detectability of 67 Ga scintigraphy with ECT in primary tumors and regional lymph node metastases was compared retrospectively with that of conventional 67 Ga scintigraphy alone. There was little improvement in detection of primary and metastatic lesions by adding 67 Ga-ECT. Only 3 primary tumors were demonstrated more distinctly by 67 Ga-ECT. However, there was no lesion which was detected only by 67 Ga-ECT. Our data indicate that inclusion of 67 Ga-ECT in the routine examination is unnecessary in cases with bronchogenic carcinoma. (author)

  4. Gallium tomoscintigraphic imaging of esophageal cancer using emission computed tomography

    International Nuclear Information System (INIS)

    Hattori, Takao; Nakagawa, Tsuyoshi; Takeda, Kan; Maeda, Hisato; Taguchi, Mitsuo

    1983-01-01

    Emission computed tomography (ECT) was clinically evaluated in 67 Ga imaging of esophageal cancer. ECT system used in this study is equipped with opposed dual large-field-of-view cameras (GCA 70A-S, Toshiba Co.). Data were acquired by rotating the two cameras 180 0 about the longitudinal axis of the patient. Total acquisition time was about 12 minutes. Multiple slices of transaxial, sagittal and coronal sections were reconstructed in a 64 x 64 matrix form using convolution algorithms. In three out of six cases studied the tumor uptake was not detected on conventional images, because the lesion was small, concentration of activity was poor or the lesion activity was overlapped with the neighbouring activities distributed to normal organs such as sternum, vertebra, liver and hilus. On ECT images, by contrast, abnormal uptake of the tumors was definitively detected in all the six cases. ECT imaging was also useful in estimating the effect of treatment by the decrease in 67 Ga concentration. We have devised a special technique to repeat ECT scan with a thin tube filled with 67 Ga solution inserted through the esophagus. By this technique, comparing paired images with and without the tube activity, exact location of the uptake against the esophagus and extraesophageal extension of the disease could be accurately evaluated in a three-dimensional field of view. ECT in gallium scanning is expected to be of great clinical value to elevate the confidence level of diagnosis in detecting, localizing and following up the diseases. (author)

  5. Proceedings of clinical SPECT [single photon emission computed tomography] symposium

    International Nuclear Information System (INIS)

    1986-09-01

    It has been five years since the last in-depth American College of Nuclear Physicians/Society of Nuclear Medicine Symposium on the subject of single photon emission computed tomography (SPECT) was held. Because this subject was nominated as the single most desired topic we have selected SPECT imaging as the basis for this year's program. The objectives of this symposium are to survey the progress of SPECT clinical applications that have taken place over the last five years and to provide practical and timely guidelines to users of SPECT so that this exciting imaging modality can be fully integrated into the evaluation of pathologic processes. The first half was devoted to a consideration of technical factors important in SPECT acquisition and the second half was devoted to those organ systems about which sufficient clinical SPECT imaging data are available. With respect to the technical aspect of the program we have selected the key areas which demand awareness and attention in order to make SPECT operational in clinical practice. These include selection of equipment, details of uniformity correction, utilization of phantoms for equipment acceptance and quality assurance, the major aspect of algorithms, an understanding of filtered back projection and appropriate choice of filters and an awareness of the most commonly generated artifacts and how to recognize them. With respect to the acquisition and interpretation of organ images, the faculty will present information on the major aspects of hepatic, brain, cardiac, skeletal, and immunologic imaging techniques. Individual papers are processed separately for the data base

  6. European health telematics networks for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-12-20

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

  7. Single-Photon Emission Computed Tomography (SPECT) in childhood epilepsy

    International Nuclear Information System (INIS)

    Gulati, Sheffali; Kalra, Veena; Bal, C.S.

    2000-01-01

    The success of epilepsy surgery is determined strongly by the precise location of the epileptogenic focus. The information from clinical electrophysiological data needs to be strengthened by functional neuroimaging techniques. Single photon emission computed tomography (SPECT) available locally has proved useful as a localising investigation. It evaluates the regional cerebral blood flow and the comparison between ictal and interictal blood flow on SPECT has proved to be a sensitive nuclear marker for the site of seizure onset. Many studies justify the utility of SPECT in localising lesions to possess greater precision than interictal scalp EEG or anatomic neuroimaging. SPECT is of definitive value in temporal lobe epilepsy. Its role in extratemporal lobe epilepsy is less clearly defined. It is useful in various other generalized and partial seizure disorders including epileptic syndromes and helps in differentiating pseudoseizures from true seizures. The need for newer radiopharmaceutical agents with specific neurochemical properties and longer shelf life are under investigation. Subtraction ictal SPECT co-registered to MRI is a promising new modality. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Shinji; Fujii, Kiyotaka; Matsushima, Toshio; Fukui, Masashi; Sadoshima, Shouzou; Kuwabara, Yasuo (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1992-03-01

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

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

    Science.gov (United States)

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

    2015-05-01

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

  10. Image-reconstruction algorithms for positron-emission tomography systems

    International Nuclear Information System (INIS)

    Cheng, S.N.C.

    1982-01-01

    The positional uncertainty in the time-of-flight measurement of a positron-emission tomography system is modelled as a Gaussian distributed random variable and the image is assumed to be piecewise constant on a rectilinear lattice. A reconstruction algorithm using maximum-likelihood estimation is derived for the situation in which time-of-flight data are sorted as the most-likely-position array. The algorithm is formulated as a linear system described by a nonseparable, block-banded, Toeplitz matrix, and a sine-transform technique is used to implement this algorithm efficiently. The reconstruction algorithms for both the most-likely-position array and the confidence-weighted array are described by similar equations, hence similar linear systems can be used to described the reconstruction algorithm for a discrete, confidence-weighted array, when the matrix and the entries in the data array are properly identified. It is found that the mean square-error depends on the ratio of the full width at half the maximum of time-of-flight measurement over the size of a pixel. When other parameters are fixed, the larger the pixel size, the smaller is the mean square-error. In the study of resolution, parameters that affect the impulse response of time-of-flight reconstruction algorithms are identified. It is found that the larger the pixel size, the larger is the standard deviation of the impulse response. This shows that small mean square-error and fine resolution are two contradictory requirements

  11. Dry coupling for whole-body small-animal photoacoustic computed tomography

    Science.gov (United States)

    Yeh, Chenghung; Li, Lei; Zhu, Liren; Xia, Jun; Li, Chiye; Chen, Wanyi; Garcia-Uribe, Alejandro; Maslov, Konstantin I.; Wang, Lihong V.

    2017-04-01

    We have enhanced photoacoustic computed tomography with dry acoustic coupling that eliminates water immersion anxiety and wrinkling of the animal and facilitates incorporating complementary modalities and procedures. The dry acoustic coupler is made of a tubular elastic membrane enclosed by a closed transparent water tank. The tubular membrane ensures water-free contact with the animal, and the closed water tank allows pressurization for animal stabilization. The dry coupler was tested using a whole-body small-animal ring-shaped photoacoustic computed tomography system. Dry coupling was found to provide image quality comparable to that of conventional water coupling.

  12. Role of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Diagnostic Evaluation of Carcinoma Urinary Bladder: Comparison with Computed Tomography

    International Nuclear Information System (INIS)

    Chakraborty, Dhritiman; Mittal, Bhagwant Rai; Kashyap, Raghava; Mete, Utham Kumar; Narang, Vikram; Das, Ashim; Bhattacharya, Anish; Khandelwal, Niranjan; Mandal, Arup K.

    2014-01-01

    Bladder carcinoma is the most frequent tumor of the urinary tract and accounts 7% of all malignancies in men and 2% of all malignancies in women. This retrospective study was carried out to assess the diagnostic utility of F18-fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the imaging evaluation of bladder carcinoma. Seventy-seven consecutive patients diagnosed to have carcinoma urinary bladder referred for F18-FDG PET/CT were included in this study. Thirty-four patients were for initial staging after transurethral biopsy and remaining 43 patients were for restaging. All patients also underwent CT scan of the abdomen and pelvis. PET/CT findings were correlated with diagnostic CT scan and histopathological findings. In 30 of the 34 patients for initial staging, both PET/CT and CT confirmed the primary lesion in the bladder. Histopathology report was available in 23 patients. Lymph nodes FDG uptake reported to be metastatic in 10/23 patients while CT detected lymph node metastasis in 12 patients. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy have been calculated to be 87.5%, 80%, 70%, 92%, 82% for PET/CT and 66%, 57%, 50%, 72%, 60% for CT respectively. PET/CT detected metastatic disease in 8 patients whereas CT detected in 4 patients. Of the 43 patients for restaging, local recurrence was detected in 24 patients on both PET/CT and CT. Histopathology report was available in 17 patients. Sensitivity, specificity, PPV, NPV and accuracy were 85%, 60%, 60%, 85%, 70% for PET/CT and 80%, 50%, 40%, 85%, 58% for CT respectively. Nineteen patients were detected to have metastatic disease by PET/CT, whereas CT detected metastases in 11 patients. F-18 FDG PET/CT is a very useful modality in pre-operative staging and monitoring after surgery, chemotherapy or radiotherapy of patients with carcinoma urinary bladder

  13. Use of Computed Tomography and Positron Emission Tomography/Computed Tomography for Staging of Local Extent in Patients With Malignant Pleural Mesothelioma

    OpenAIRE

    Frauenfelder, Thomas; Kestenholz, Peter; Hunziker, Roger; Nguyen, Thi Dan Linh; Fries, Martina; Veit-Haibach, Patrick; Husmann, Lars; Stahel, Rolf; Weder, Walter; Opitz, Isabelle

    2015-01-01

    PURPOSE The objective of this study was to determine the diagnostic value of computed tomography (CT) and positron emission tomography (PET)/CT for staging of malignant pleural mesothelioma (MPM) in patients undergoing induction chemotherapy. METHODS Sixty-two patients (median age, 61 years; female: n = 9) with proven MPM underwent CT after induction chemotherapy. Of these, 28 underwent additional PET/CT. Extrapleural pneumonectomy was performed for pathological TNM staging. Clinical TNM s...

  14. Roles of computed tomography and [18F]fluorodeoxyglucose-positron emission tomography/computed tomography in the characterization of multiple solitary solid lung nodules

    OpenAIRE

    Travaini, LL; Trifirò, G; Vigna, PD; Veronesi, G; De Pas, TM; Spaggiari, L; Paganelli, G; Bellomi, M

    2012-01-01

    The purpose of this study is to compare the performance of multidetector computed tomography (CT) and positron emission tomography/CT (PET/CT) with [18F]fluorodeoxyglucose in the diagnosis of multiple solitary lung nodules in 14 consecutive patients with suspicious lung cancer. CT and PET/CT findings were reviewed by a radiologist and nuclear medicine physician, respectively, blinded to the pathological diagnoses of lung cancer, considering nodule size, shape, and location (CT) and maximum st...

  15. Relationship of computed tomography perfusion and positron emission tomography to tumour progression in malignant glioma

    Energy Technology Data Exchange (ETDEWEB)

    Yeung, Timothy P C [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Robarts Research Institute, The University of Western Ontario, Ontario, Canada, N6A 5B7 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Yartsev, Slav [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Lee, Ting-Yim [Robarts Research Institute, The University of Western Ontario, Ontario, Canada, N6A 5B7 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Department of Medical Imaging, The University of Western Ontario, London Health Sciences Centre, Victoria Hospital, Ontario, Canada, N6A 5W9 (Australia); Lawson Health Research Institute, St. Joseph' s Health Care London, Ontario, Canada, N6A 4V2 (Canada); Wong, Eugene [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Department of Physics and Astronomy, The University of Western Ontario, Ontario, Canada, N6A 3K7 (Canada); He, Wenqing [Department of Statistical and Actuarial Sciences, The University of Western Ontario, Ontario, Canada, N6A 5B7 (Canada); Fisher, Barbara; VanderSpek, Lauren L [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Macdonald, David [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Department of Clinical Neurological Sciences, The University of Western Ontario, London Health Sciences Centre, University Hospital, Ontario, Canada, N6A 5A5 (Canada); Bauman, Glenn, E-mail: glenn.bauman@lhsc.on.ca [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada)

    2014-02-15

    Introduction: This study aimed to explore the potential for computed tomography (CT) perfusion and 18-Fluorodeoxyglucose positron emission tomography (FDG-PET) in predicting sites of future progressive tumour on a voxel-by-voxel basis after radiotherapy and chemotherapy. Methods: Ten patients underwent pre-radiotherapy magnetic resonance (MR), FDG-PET and CT perfusion near the end of radiotherapy and repeated post-radiotherapy follow-up MR scans. The relationships between these images and tumour progression were assessed using logistic regression. Cross-validation with receiver operating characteristic (ROC) analysis was used to assess the value of these images in predicting sites of tumour progression. Results: Pre-radiotherapy MR-defined gross tumour; near-end-of-radiotherapy CT-defined enhancing lesion; CT perfusion blood flow (BF), blood volume (BV) and permeability-surface area (PS) product; FDG-PET standard uptake value (SUV); and SUV:BF showed significant associations with tumour progression on follow-up MR imaging (P < 0.0001). The mean sensitivity (±standard deviation), specificity and area under the ROC curve (AUC) of PS were 0.64 ± 0.15, 0.74 ± 0.07 and 0.72 ± 0.12 respectively. This mean AUC was higher than that of the pre-radiotherapy MR-defined gross tumour and near-end-of-radiotherapy CT-defined enhancing lesion (both AUCs = 0.6 ± 0.1, P ≤ 0.03). The multivariate model using BF, BV, PS and SUV had a mean AUC of 0.8 ± 0.1, but this was not significantly higher than the PS only model. Conclusion: PS is the single best predictor of tumour progression when compared to other parameters, but voxel-based prediction based on logistic regression had modest sensitivity and specificity.

  16. Role of positron emission tomography-computed tomography in endometrial cancer

    Science.gov (United States)

    Erdemoğlu, Evrim; Çerçi, Sevim Süreyya; Erdemoğlu, Ebru; Yalçın, Yakup; Tatar, Burak

    2017-01-01

    Objective: The efficacy of preoperative 18F-fluoro-D-glucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) in endometrium cancer is controversial. We examined the efficacy of PET-CT and the association between maximum standardized uptake value (SUVmax) and prognostic factors in endometrial cancer. Materials and Methods: Thirty patients with endometrial cancer underwent preoperative 18F-FDG/PET-CT. The patients were treated with abdominal hysterectomy with bilateral salpingo-oophorectomy, and bilateral systemic pelvic lymphadenectomy was planned for all patients; paraaortic lymphadenectomy was performed in patients with intermediate and high risk. Tumor histology, grade, depth of myometrial invasion, maximum tumor diameter, lymphovascular invasion, nodal status, and ovarian/adnexal metastases were recorded. Results: The mean primary tumor diameter was reported smaller in PET-CT and the effect size of PET-CT was -0.60. The kappa value was 0.06 for myometrial invasion. Pelvic lymph node metastasis was reported in 22.2% of patients in PET-CT. However, 3.7% of patients had pelvic lymph node metastasis. The kappa value for pelvic lymph node metastasis was 0.23, and sensitivity, specificity, and positive and negative predictive values were 100%, 80.7%, 16.6%, and 100%, respectively. Paraaortic lymph node metastasis in PET-CT was suspected in 10%. However, paraaortic lymph node metastasis was found in 6.7% in histopathologic analyses. The kappa value was 0.15. The sensitivity, specificity, and positive and negative predictive values of PET-CT for detecting paraaortic lymph node metastases were 100%, 93.7%, 66.6%, and 100%, respectively. Myometrial invasion and tumor diameter were the only important prognostic factors affecting SUVmax. Conclusion: According to our results, PET-CT has a limited role and diagnostic efficacy in endometrial cancer. The indications of FDG/PET-CT in endometrium cancer should be studied further and revised. PMID:29379661

  17. Positron emission tomography combined with computed tomography for diagnosis of synchronous and metachronous tumors

    International Nuclear Information System (INIS)

    Zlatareva, D.; Garcheva, M.; Hadjiiska, V.

    2013-01-01

    Full text: Introduction: Positron emission tomography combined computed tomography (PET/CT) has proved to be the method of choice in oncology for diagnosis and staging, planning and determining the effect of treatment. Aim of the study was to determine the diagnostic capabilities of PET/CT for the detection of synchronous and metachronous tumors. Materials and Methods: The study was conducted with 18F FDG on Discovery, GE Healthcare under standard protocol. 18F FDG is dosed per kg body weight applying before a meal in blood sugar within reference values. The survey was conducted 60 min after application, in addition to visual assessment using quantitative indicators. For a period of a year (2012) 1408 patients were studied. In 11 (2 men, 9 women) of them synchronous and metachronous unsuspected tumors were found. Results: The most common as the second tumors are found processes in the head and neck, followed by lung cancer and colorectal cancer. In four of the cases operational or histological verification was made. In others cases due to refusal or advanced disease indications for systemic therapy the verification wasn't made. Diagnosis of the second tumor has changed the approach to patients as the therapeutic effect was detected at 3 patients over a period of nine months by repeated PET/CT study. Conclusion: The hybrid PET/CT, combining information about structural changes (CT) and metabolic changes (PET) plays an important role in the diagnosis of synchronous and metachronous tumors. This can significantly change the therapeutic management and prognosis of patients

  18. Positron emission tomography/computed tomography--imaging protocols, artifacts, and pitfalls.

    Science.gov (United States)

    Bockisch, Andreas; Beyer, Thomas; Antoch, Gerald; Freudenberg, Lutz S; Kühl, Hilmar; Debatin, Jörg F; Müller, Stefan P

    2004-01-01

    There has been a longstanding interest in fused images of anatomical information, such as that provided by computed tomography (CT) or magnetic resonance imaging (MRI) systems, with biological information obtainable by positron emission tomography (PET). The near-simultaneous data acquisition in a fixed combination of a PET and a CT scanner in a combined PET/CT imaging system minimizes spatial and temporal mismatches between the modalities by eliminating the need to move the patient in between exams. In addition, using the fast CT scan for PET attenuation correction, the duration of the examination is significantly reduced compared to standalone PET imaging with standard rod-transmission sources. The main source of artifacts arises from the use of the CT-data for scatter and attenuation correction of the PET images. Today, CT reconstruction algorithms cannot account for the presence of metal implants, such as dental fillings or prostheses, properly, thus resulting in streak artifacts, which are propagated into the PET image by the attenuation correction. The transformation of attenuation coefficients at X-ray energies to those at 511 keV works well for soft tissues, bone, and air, but again is insufficient for dense CT contrast agents, such as iodine or barium. Finally, mismatches, for example, due to uncoordinated respiration result in incorrect attenuation-corrected PET images. These artifacts, however, can be minimized or avoided prospectively by careful acquisition protocol considerations. In doubt, the uncorrected images almost always allow discrimination between true and artificial finding. PET/CT has to be integrated into the diagnostic workflow for harvesting the full potential of the new modality. In particular, the diagnostic power of both, the CT and the PET within the combination must not be underestimated. By combining multiple diagnostic studies within a single examination, significant logistic advantages can be expected if the combined PET

  19. Relationship of computed tomography perfusion and positron emission tomography to tumour progression in malignant glioma

    International Nuclear Information System (INIS)

    Yeung, Timothy P C; Yartsev, Slav; Lee, Ting-Yim; Wong, Eugene; He, Wenqing; Fisher, Barbara; VanderSpek, Lauren L; Macdonald, David; Bauman, Glenn

    2014-01-01

    Introduction: This study aimed to explore the potential for computed tomography (CT) perfusion and 18-Fluorodeoxyglucose positron emission tomography (FDG-PET) in predicting sites of future progressive tumour on a voxel-by-voxel basis after radiotherapy and chemotherapy. Methods: Ten patients underwent pre-radiotherapy magnetic resonance (MR), FDG-PET and CT perfusion near the end of radiotherapy and repeated post-radiotherapy follow-up MR scans. The relationships between these images and tumour progression were assessed using logistic regression. Cross-validation with receiver operating characteristic (ROC) analysis was used to assess the value of these images in predicting sites of tumour progression. Results: Pre-radiotherapy MR-defined gross tumour; near-end-of-radiotherapy CT-defined enhancing lesion; CT perfusion blood flow (BF), blood volume (BV) and permeability-surface area (PS) product; FDG-PET standard uptake value (SUV); and SUV:BF showed significant associations with tumour progression on follow-up MR imaging (P < 0.0001). The mean sensitivity (±standard deviation), specificity and area under the ROC curve (AUC) of PS were 0.64 ± 0.15, 0.74 ± 0.07 and 0.72 ± 0.12 respectively. This mean AUC was higher than that of the pre-radiotherapy MR-defined gross tumour and near-end-of-radiotherapy CT-defined enhancing lesion (both AUCs = 0.6 ± 0.1, P ≤ 0.03). The multivariate model using BF, BV, PS and SUV had a mean AUC of 0.8 ± 0.1, but this was not significantly higher than the PS only model. Conclusion: PS is the single best predictor of tumour progression when compared to other parameters, but voxel-based prediction based on logistic regression had modest sensitivity and specificity

  20. Enhancement of positron emission tomography-computed tomography image quality using the principle of stochastic resonance

    International Nuclear Information System (INIS)

    Pandey, Anil Kumar; Sharma, Sanjay Kumar; Sharma, Punit; Singh, Harmandeep; Patel, Chetan; Sarkar, Kaushik; Kumar, Rakesh; Bal, Chandra Sekhar

    2014-01-01

    Acquisition of higher counts improves visual perception of positron emission tomography-computed tomography (PET-CT) image. Larger radiopharmaceutical doses (implies more radiation dose) are administered to acquire this count in a short time period. However, diagnostic information does not increase after a certain threshold of counts. This study was conducted to develop a post processing method based on principle of “stochastic resonance” to improve visual perception of the PET-CT image having a required threshold counts. PET-CT images (JPEG file format) with low, medium, and high counts in the image were included in this study. The image was corrupted with the addition of Poisson noise. The amplitude of the Poisson noise was adjusted by dividing each pixel by a constant 1, 2, 4, 8, 16, and 32. The best amplitude of the noise that gave best images quality was selected based on high value of entropy of the output image, high value of structural similarity index and feature similarity index. Visual perception of the image was evaluated by two nuclear medicine physicians. The variation in structural and feature similarity of the image was not appreciable visually, but statistically images deteriorated as the noise amplitude increases although maintaining structural (above 70%) and feature (above 80%) similarity of input images in all cases. We obtained the best image quality at noise amplitude “4” in which 88% structural and 95% feature similarity of the input images was retained. This method of stochastic resonance can be used to improve the visual perception of the PET-CT image. This can indirectly lead to reduction of radiation dose

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  2. Measurement of blood-brain barrier permeability with positron emission tomography in patients with multiple sclerosis

    International Nuclear Information System (INIS)

    Fieschi, C.; Pozzilli, C.; Bernardi, S.; Bozzao, L.; Lenzi, G.L.; Picozzi, P.; Iannotti, F.; Conforti, P.

    1988-01-01

    The purpose of the investigation was to elucidate the role of positron emission tomography using 68 Ga-EDTA in the study of blood-brain barrier abnormalities associated with multiple sclerosis. 14 refs.; 1 figure

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

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

    DEFF Research Database (Denmark)

    Ripa, Rasmus Sejersten; Kjær, Andreas

    2015-01-01

    Noninvasive imaging of atherosclerosis could potentially move patient management towards individualized triage, treatment, and followup. The newly introduced combined positron emission tomography (PET) and magnetic resonance imaging (MRI) system could emerge as a key player in this context. Both...

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

    International Nuclear Information System (INIS)

    Baron, J.C.

    1986-05-01

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

  6. Evaluation of esophageal cancer by positron emission tomography

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  7. Computed tomography angiography and perfusion to assess coronary artery stenosis causing perfusion defects by single photon emission computed tomography

    DEFF Research Database (Denmark)

    Rochitte, Carlos E; George, Richard T; Chen, Marcus Y

    2014-01-01

    AIMS: To evaluate the diagnostic power of integrating the results of computed tomography angiography (CTA) and CT myocardial perfusion (CTP) to identify coronary artery disease (CAD) defined as a flow limiting coronary artery stenosis causing a perfusion defect by single photon emission computed...... emission computed tomography (SPECT/MPI). Sixteen centres enroled 381 patients who underwent combined CTA-CTP and SPECT/MPI prior to conventional coronary angiography. All four image modalities were analysed in blinded independent core laboratories. The prevalence of obstructive CAD defined by combined ICA...... tomography (SPECT). METHODS AND RESULTS: We conducted a multicentre study to evaluate the accuracy of integrated CTA-CTP for the identification of patients with flow-limiting CAD defined by ≥50% stenosis by invasive coronary angiography (ICA) with a corresponding perfusion deficit on stress single photon...

  8. Fluorodeoxyglucose positron emission tomography/computed tomography findings in a patient with cerebellar mutism after operation in posterior fossa

    Directory of Open Access Journals (Sweden)

    Gonca Kara Gedik

    2017-03-01

    Full Text Available Cerebellar mutism is a transient period of speechlessness that evolves after posterior fossa surgery in children. Although direct cerebellar and brain stem injury and supratentorial dysfunction have been implicated in the mediation of mutism, the pathophysiological mechanisms involved in the evolution of this kind of mutism remain unclear. Magnetic resonance imaging revealed dentatothalamocortical tract injuries and single photon emission computed tomography showed cerebellar and cerebral hypoperfusion in patients with cerebellar mutism. However, findings with 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT in this group of patients have not been documented previously. In this clinical case, we report a patient who experienced cerebellar mutism after undergoing a posterior fossa surgery. Right cerebellar and left frontal lobe hypometabolism was shown using FDG PET/CT. The FDG metabolism of both the cerebellum and the frontal lobe returned to normal levels after the resolution of the mutism symptoms.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

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

  10. 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

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

    Science.gov (United States)

    Howell, Leonard Lee; Murnane, Kevin Sean

    2011-05-01

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

  12. Proceedings of clinical SPECT (single photon emission computed tomography) symposium

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    It has been five years since the last in-depth American College of Nuclear Physicians/Society of Nuclear Medicine Symposium on the subject of single photon emission computed tomography (SPECT) was held. Because this subject was nominated as the single most desired topic we have selected SPECT imaging as the basis for this year's program. The objectives of this symposium are to survey the progress of SPECT clinical applications that have taken place over the last five years and to provide practical and timely guidelines to users of SPECT so that this exciting imaging modality can be fully integrated into the evaluation of pathologic processes. The first half was devoted to a consideration of technical factors important in SPECT acquisition and the second half was devoted to those organ systems about which sufficient clinical SPECT imaging data are available. With respect to the technical aspect of the program we have selected the key areas which demand awareness and attention in order to make SPECT operational in clinical practice. These include selection of equipment, details of uniformity correction, utilization of phantoms for equipment acceptance and quality assurance, the major aspect of algorithms, an understanding of filtered back projection and appropriate choice of filters and an awareness of the most commonly generated artifacts and how to recognize them. With respect to the acquisition and interpretation of organ images, the faculty will present information on the major aspects of hepatic, brain, cardiac, skeletal, and immunologic imaging techniques. Individual papers are processed separately for the data base. (TEM)

  13. Oxygen-15 labelled water production for positron emission tomography

    International Nuclear Information System (INIS)

    Janus, A.; Sachinidis, J.I.; Chan, J.G.; Tochon-Danguy, H.J.

    1998-01-01

    Full text: Functional imaging using positron emission tomography (PET) and 15 O-labelled compounds is both scientifically and clinically challenging. The short half-life of oxygen-15 (t 1/2 = 2 min) allows for multiple administration to a patient without exceeding acceptable levels of absorbed radiation dose and without excessive delay between administrations. The clinical usefulness of [ 15 O]-labelled water for cerebral blood flow measurements has been well established. Here we report the development and construction of a [ 15 O]water generator based on an earlier design from Hammersmith Hospital, London. The cyclotron produces a continuous flow of [ 15 O]O 2 gas by the irradiation of a natural nitrogen target (1% O 2 in N 2 ) with a 5 MeV deuteron beam, via the nuclear reaction ( 14 N(d,n) 15 O). The radioactive gas is then mixed with 5% hydrogen in nitrogen and piped to the water generator located in the scanner room. The O 2 /N 2 gas mixture is reacted over a palladium catalyst at 1500 deg C to produce [ 15 O]H 2 O vapour. The vapour passes through an exchanger where it diffuses across a semi-permeable membrane (cellulose acetate) into saline solution. At the optimum gas flow- rate of 500 mL/min, more than 95% of the radioactive oxygen is converted to radioactive water. Waste radioactive gas is piped back to the cyclotron vault to decay before release into the atmosphere. The saline solution (0.9% NaCl) is pumped continuously through the system at 6 mL/min with an infusion pump (3M AVI470). The present system has been in operation for more than a year and has been used for clinical evaluation of stroke patients and for brain activation research studies

  14. Study of brain metabolism using positron emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Heiss, W D

    1983-03-21

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

  15. Diagnosis of temporal lobe epilepsy by positron emission tomography

    International Nuclear Information System (INIS)

    Shimizu, Hiroyuki; Ishijima, Buichi; Iio, Masaaki.

    1985-01-01

    Positron emission tomography(PET) was performed in 18 temporal lobe epileptics. About 20 mCi of 11 C-glucose was perorally administered to the patients and 30 minutes later scanning was started when the transport of 11 C-glucose from blood to the brain tissue reached equilibrium. At the level of 25mm above orbitomeatal line, the slice image of the temporal lobe shows a relatively high metabolic oval ring involving the amygdala, hippocapal formation and the hippocampal gyrus medially and the T 1 , T 2 and T 3 neocortices laterally in normal subjects. The epileptic focus, when detected on PET images, was observed as a defect in this oval ring. In 15(83.3%) out of 18 cases, the location of epileptic focus was confirmed as a low metabolic defect. This diagnosis rate was higher than that of other focal epilepsy by PET study. The locations of foci were devided into three types: mesial (5 cases), lateral (4 cases) and combined (6 cases). The seizure symptoms of the patients were analyzed in terms of the correspondence to the focus types. The results showed that automatism and pseudoabsence had a close relation to the mesial and combined types and psychical, vertiginous or visual seizures correlated to the combined and lateral types. Visceral or motor seizures were induced equally by any focus types. These facts suggested that automatism and pseudoabsence were correlated with the mesial organs such as the amygdala and hippocampus and psychical, vertiginous or visual seizures had origin in lateral neocortices. Visceral or motor seizures were supposed to be the results of the spread from the temporal focus to the adjacent structures. It was concluded that PET was very useful in localization diagnosis of temporal lobe epilepsy. In surgical treatment of epilepsy, in which the knowledge of the exact extent of epileptic foci is strongly demanded, PET study will offer invaluable data to the strategy of operation and foreseeing its prognosis. (author)

  16. Application of positron emission tomography in industrial research

    International Nuclear Information System (INIS)

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

    1990-01-01

    Positron Emission computed Tomography (PET) is a relatively new imaging technique, exploiting the 511 keV annihilation radiation characteristic of positron emitters. Although exclusively used till now in the field of nuclear medicine, the application of PET for the non-invasive, in-situ visualisation of processes of industrial interest is challenging, because PET can in principle be used to obtain quantitative, 2D/3D images of the flow and distribution of fluids inside process units, whose steel walls may be up to several centimeters thick. With the aid of a NeuroECAT positron tomographer the PET technique has been utilised to image important (model) processes in the petrochemical industry, using physical labelling of the phase to be imaged. First, the displacement of a brine/surfactant phase, labelled with 66 Ga-EDTA, in a piece of reservoir rock was imaged. Secondly, the dehydration of water-in-oil emulsions was monitored dynamically by labelling the water phase with 68 Ga-EDTA. The second study in particular demonstrates that in the presence of noisy data the image reconstruction method utilised strongly influences the results obtained. With the advent of PET in nuclear medicine the availability of short-lived positron emitting nuclides like 11 C (t1/2 = 20 min), 13 N (t1/2 = 10 min) and 15 0 (t1/2 = 2 min) has increased considerably, allowing the investigation of industrially important reactions by chemical labelling. Utilising the NeuroECAT in a special mode, the catalytic oxidation of carbon monoxide could be imaged in a model tubular reactor by using 11 C-labelled CO, providing information about the kinetics of the individual reaction steps and interactions and about the degree of occupation of catalytically active sites. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Zizhong Li

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

  19. Study of optical emission spectroscopy with inductively coupled plasma torch

    International Nuclear Information System (INIS)

    Bauer, M.

    1982-01-01

    Inductively coupled plasma optical emission spectroscopy is an excellent tool for quantitative multielement trace analysis. This paper describes the performance of a computer-controlled sequential measurement system. Chemical and ionization interferences are shown to be negligible due to the characteristics of the inductively coupled plasma, spectral interferences are eliminated by using a high-resolution monochromator and computer data handling. Good accuracy is achieved for most of the interesting elements, as is shown from both an interlaboratory test and from comparison of the results of water samples from the rivers Elbe and Weser with those achieved with neutron activation and X-ray fluorescence analysis. (orig.) [de

  20. Clinical value of whole body fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of metastatic bladder cancer.

    Science.gov (United States)

    Yang, Zhongyi; Pan, Lingling; Cheng, Jingyi; Hu, Silong; Xu, Junyan; Ye, Dingwei; Zhang, Yingjian

    2012-07-01

    To investigate the value of whole-body fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography for the detection of metastatic bladder cancer. From December 2006 to August 2010, 60 bladder cancer patients (median age 60.5 years old, range 32-96) underwent whole body positron emission tomography/computed tomography positron emission tomography/computed tomography. The diagnostic accuracy was assessed by performing both organ-based and patient-based analyses. Identified lesions were further studied by biopsy or clinically followed for at least 6 months. One hundred and thirty-four suspicious lesions were identified. Among them, 4 primary cancers (2 pancreatic cancers, 1 colonic and 1 nasopharyngeal cancer) were incidentally detected, and the patients could be treated on time. For the remaining 130 lesions, positron emission tomography/computed tomography detected 118 true positive lesions (sensitivity = 95.9%). On the patient-based analysis, the overall sensitivity and specificity resulted to be 87.1% and 89.7%, respectively. There was no difference of sensitivity and specificity in patients with or without adjuvant treatment in terms of detection of metastatic sites by positron emission tomography/computed tomography. Compared with conventional imaging modality, positron emission tomography/computed tomography correctly changed the management in 15 patients (25.0%). Positron emission tomography/computed tomography has excellent sensitivity and specificity in the detection of metastatic bladder cancer and it provides additional diagnostic information compared to standard imaging techniques. © 2012 The Japanese Urological Association.

  1. Clinical value of whole body fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of metastatic bladder cancer

    International Nuclear Information System (INIS)

    Yang Zhongyi; Pan Lingling; Cheng Jingyi; Hu Silong; Xu Junyan; Zhang Yingjian; Ye Dingwei

    2012-01-01

    The objective of this study was to investigate the value of whole-body fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography for the detection of metastatic bladder cancer. From December 2006 to August 2010, 60 bladder cancer patients (median age 60.5 years old, range 32-96) underwent whole body positron emission tomography/computed tomography positron emission tomography/computed tomography. The diagnostic accuracy was assessed by performing both organ-based and patient-based analyses. Identified lesions were further studied by biopsy or clinically followed for at least 6 months. One hundred and thirty-four suspicious lesions were identified. Among them, 4 primary cancers (2 pancreatic cancers, 1 colonic and 1 nasopharyngeal cancer) were incidentally detected, and the patients could be treated on time. For the remaining 130 lesions, positron emission tomography/computed tomography detected 118 true positive lesions (sensitivity=95.9%). On the patient-based analysis, the overall sensitivity and specificity resulted to be 87.1% and 89.7%, respectively. There was no difference of sensitivity and specificity in patients with or without adjuvant treatment in terms of detection of metastatic sites by positron emission tomography/computed tomography. Compared with conventional imaging modality, positron emission tomography/computed tomography correctly changed the management in 15 patients (25.0%). Positron emission tomography/computed tomography has excellent sensitivity and specificity in the detection of metastatic bladder cancer and it provides additional diagnostic information compared to standard imaging techniques. (author)

  2. 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.

  3. 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

  4. Detection of non-aggressive stage IA lung cancer using chest computed tomography and positron emission tomography/computed tomography.

    Science.gov (United States)

    Shiono, Satoshi; Yanagawa, Naoki; Abiko, Masami; Sato, Toru

    2014-10-01

    In contrast to lung cancer with ground-glass opacity, the radiological investigation of solid lung cancer has not been well examined. The aim of this study was to explore chest computed tomography (CT) and positron emission tomography (PET)/CT findings with regard to outcomes after lung cancer surgery in order to radiologically classify clinical stage IA lung cancers by tumour aggressiveness. Three hundred and fifteen clinical stage IA patients were analysed. Four groups were defined by tumour solidity on CT and by the standardized uptake value (SUV) index on PET-CT (tumour maximum SUV/mean right liver lobe SUV). We analysed the association between radiological findings and both pathological invasiveness and postoperative outcome. Group A (n = 84) had an SUV index <1.0 and non-solid tumours, Group B (n = 24) had an SUV index <1.0 and solid tumours, Group C (n = 54) had an SUV index ≥1.0 and non-solid tumours, while Group D (n = 153) had an SUV index ≥1.0 and solid tumours. Invasive lung cancer was found in 2/84 (2.4%) patients in Group A, 1/24 (4.2%) in Group B, 13/54 (24.1%) in Group C and 58/153 (37.9%) in Group D (P < 0.01). The 5-year recurrence-free rate was 100% in Groups A and B, 90.3% in C and 65.7% in D (P < 0.01). The cancer-specific survival rate was 100% in A and B, 94.6% in C and 81.7% in D (P < 0.01). The present results suggest that preoperative PET/CT and thin-section CT findings provide important information for a selection of surgical procedures for clinical stage IA lung cancers. In clinical stage IA lung cancers displaying solid or non-solid density in thin-section findings, an SUV index <1.0 may be a better criterion for detecting non-aggressive lung cancer even in solid lung cancers. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  5. Positron Emission Tomography Computed Tomography: A Guide for the General Radiologist.

    Science.gov (United States)

    Beadsmoore, Clare; Newman, David; MacIver, Duncan; Pawaroo, Davina

    2015-11-01

    Cancer remains a leading cause of death in Canada and worldwide. Whilst advances in anatomical imaging to detect and monitor malignant disease have continued over the last few decades, limitations remain. Functional imaging, such as positron emission tomography (PET), has improved the sensitivity and specificity in detecting malignant disease. In combination with computed tomography (CT), PET is now commonly used in the oncology setting and is an integral part of many cancer patients' pathways. Although initially the CT component of the study was purely for attenuation of the PET imaging and to provide anatomical coregistration, many centers now combine the PET study with a diagnostic quality contrast enhanced CT to provide one stop staging, thus refining the patient's pathway. The commonest tracer used in everyday practice is FDG (F18-fluorodeoxyglucose). There are many more tracers in routine clinical practice and those with emerging roles, such as 11C-choline, useful in the imaging of prostate cancer; 11C-methionine, useful in imaging brain tumours; C11-acetate, used in imaging hepatocellular carcinomas; 18F-FLT, which can be used as a marker of cellular proliferation in various malignancies; and F18-DOPA and various 68Ga-somatostatin analogues, used in patients with neuroendocrine tumours. In this article we concentrate on FDG PETCT as this is the most commonly available and widely utilised tracer now used to routinely stage a number of cancers. PETCT alters the stage in approximately one-third of patients compared to anatomical imaging alone. Increasingly, PETCT is being used to assess early metabolic response to treatment. Metabolic response can be seen much earlier than a change in the size/volume of the disease which is measured by standard CT imaging. This can aid treatment decisions in both in terms of modifying therapy and in addition to providing important prognostic information. Furthermore, it is helpful in patients with distorted anatomy from surgery

  6. Budget impact from the incorporation of positron emission tomography - computed tomography for staging lung cancers.

    Science.gov (United States)

    Biz, Aline Navega; Caetano, Rosângela

    2015-01-01

    To estimate the budget impact from the incorporation of positron emission tomography (PET) in mediastinal and distant staging of non-small cell lung cancer. The estimates were calculated by the epidemiological method for years 2014 to 2018. Nation-wide data were used about the incidence; data on distribution of the disease's prevalence and on the technologies' accuracy were from the literature; data regarding involved costs were taken from a micro-costing study and from Brazilian Unified Health System (SUS) database. Two strategies for using PET were analyzed: the offer to all newly-diagnosed patients, and the restricted offer to the ones who had negative results in previous computed tomography (CT) exams. Univariate and extreme scenarios sensitivity analyses were conducted to evaluate the influence from sources of uncertainties in the parameters used. The incorporation of PET-CT in SUS would imply the need for additional resources of 158.1 BRL (98.2 USD) million for the restricted offer and 202.7 BRL (125.9 USD) million for the inclusive offer in five years, with a difference of 44.6 BRL (27.7 USD) million between the two offer strategies within that period. In absolute terms, the total budget impact from its incorporation in SUS, in five years, would be 555 BRL (345 USD) and 600 BRL (372.8 USD) million, respectively. The costs from the PET-CT procedure were the most influential parameter in the results. In the most optimistic scenario, the additional budget impact would be reduced to 86.9 BRL (54 USD) and 103.8 BRL (64.5 USD) million, considering PET-CT for negative CT and PET-CT for all, respectively. The incorporation of PET in the clinical staging of non-small cell lung cancer seems to be financially feasible considering the high budget of the Brazilian Ministry of Health. The potential reduction in the number of unnecessary surgeries may cause the available resources to be more efficiently allocated.

  7. Budget impact from the incorporation of positron emission tomography – computed tomography for staging lung cancers

    Directory of Open Access Journals (Sweden)

    Aline Navega Biz

    2015-01-01

    Full Text Available OBJECTIVE To estimate the budget impact from the incorporation of positron emission tomography (PET in mediastinal and distant staging of non-small cell lung cancer.METHODS The estimates were calculated by the epidemiological method for years 2014 to 2018. Nation-wide data were used about the incidence; data on distribution of the disease´s prevalence and on the technologies’ accuracy were from the literature; data regarding involved costs were taken from a micro-costing study and from Brazilian Unified Health System (SUS database. Two strategies for using PET were analyzed: the offer to all newly-diagnosed patients, and the restricted offer to the ones who had negative results in previous computed tomography (CT exams. Univariate and extreme scenarios sensitivity analyses were conducted to evaluate the influence from sources of uncertainties in the parameters used.RESULTS The incorporation of PET-CT in SUS would imply the need for additional resources of 158.1 BRL (98.2 USD million for the restricted offer and 202.7 BRL (125.9 USD million for the inclusive offer in five years, with a difference of 44.6 BRL (27.7 USD million between the two offer strategies within that period. In absolute terms, the total budget impact from its incorporation in SUS, in five years, would be 555 BRL (345 USD and 600 BRL (372.8 USD million, respectively. The costs from the PET-CT procedure were the most influential parameter in the results. In the most optimistic scenario, the additional budget impact would be reduced to 86.9 BRL (54 USD and 103.8 BRL (64.5 USD million, considering PET-CT for negative CT and PET-CT for all, respectively.CONCLUSIONS The incorporation of PET in the clinical staging of non-small cell lung cancer seems to be financially feasible considering the high budget of the Brazilian Ministry of Health. The potential reduction in the number of unnecessary surgeries may cause the available resources to be more efficiently allocated.

  8. Does positron emission tomography/computed tomography aid the diagnosis of prosthetic valve infective endocarditis?

    Science.gov (United States)

    Balmforth, Damian; Chacko, Jacob; Uppal, Rakesh

    2016-10-01

    A best evidence topic was constructed according to a structured protocol. The question addressed was whether (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) aids the diagnosis of prosthetic valve endocarditis (PVE)? A total of 107 publications were found using the reported search, of which 6 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The reported outcome of all studies was a final diagnosis of confirmed endocarditis on follow-up. All the six studies were non-randomized, single-centre, observational studies and thus represented level 3 evidence. The diagnostic capability of PET/CT for PVE was compared with that of the modified Duke Criteria and echocardiography, and reported in terms of sensitivity, specificity and positive and negative predictive values. All studies demonstrated an increased sensitivity for the diagnosis of PVE when PET/CT was combined with the modified Duke Criteria on admission. A higher SUVmax on PET was found to be significantly associated with a confirmed diagnosis of endocarditis and an additional diagnostic benefit of PET/CT angiography over conventional PET/non-enhanced CT is reported due to improved anatomical resolution. However, PET/CT was found to be unreliable in the early postoperative period due to its inability to distinguish between infection and residual postoperative inflammatory changes. PET/CT was also found to be poor at diagnosing cases of native valve endocarditis. We conclude that PET/CT aids in the diagnosis of PVE when combined with the modified Duke Criteria on admission by increasing the diagnostic sensitivity. The diagnostic ability of PET/CT can be potentiated by the use of PET/CTA; however, its use may be unreliable in the early postoperative period or in native valve endocarditis. © The Author 2016. Published by

  9. Simulation Study of Single Photon Emission Computed Tomography for Industrial Applications

    International Nuclear Information System (INIS)

    Roy, Tushar; Sarkar, P. S.; Sinha, Amar

    2008-01-01

    SPECT (Single Photon Emission Computed Tomography) provides for an invaluable non-invasive technique for the characterization and activity distribution of the gamma-emitting source. For many applications of radioisotopes for medical and industrial application, not only the positional information of the distribution of radioisotopes is needed but also its strength. The well-established X-ray radiography or transmission tomography techniques do not yield sufficient quantitative information about these objects. Emission tomography is one of the important methods for such characterization. Application of parallel beam, fan beam and 3D cone beam emission tomography methods have been discussed in this paper. Simulation studies to test these algorithms have been carried out to validate the technique.

  10. The contribution of single photon emission computed tomography in the clinical assessment of Alzheimer type dementia

    International Nuclear Information System (INIS)

    Boudousq, V.; Collombier, L.; Kotzki, P.O.

    1999-01-01

    Interest of brain single-photon emission computed tomography to support clinical diagnosis of Alzheimer-type dementia is now established. Numerous studies have reported a decreased perfusion in the association cortex of the parietal lobe and the posterior temporal regions. In patients with mild cognitive complaints, the presence of focal hypoperfusion may increase substantially the probability of the disease. In addition, emission tomography emerges as a helpful tool in situation in which there is diagnostic doubt. In this case, the presence of temporo-parietal perfusion deficit associated with hippocampal atrophy on MRI or X-ray computed tomography contributes to diagnostic accuracy. However, some studies suggest that emission tomography may be useful for preclinical prediction of Alzheimer's disease and to predict cognitive decline. (author)

  11. A general class of preconditioners for statistical iterative reconstruction of emission computed tomography

    International Nuclear Information System (INIS)

    Chinn, G.; Huang, S.C.

    1997-01-01

    A major drawback of statistical iterative image reconstruction for emission computed tomography is its high computational cost. The ill-posed nature of tomography leads to slow convergence for standard gradient-based iterative approaches such as the steepest descent or the conjugate gradient algorithm. In this paper new theory and methods for a class of preconditioners are developed for accelerating the convergence rate of iterative reconstruction. To demonstrate the potential of this class of preconditioners, a preconditioned conjugate gradient (PCG) iterative algorithm for weighted least squares reconstruction (WLS) was formulated for emission tomography. Using simulated positron emission tomography (PET) data of the Hoffman brain phantom, it was shown that the convergence rate of the PCG can reduce the number of iterations of the standard conjugate gradient algorithm by a factor of 2--8 times depending on the convergence criterion

  12. Recurrent proliferating trichilemmal tumor with malignant change on the f-18 fluorodeoxyglucose position emission tomography/computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Eun Ha; Kim, Eun Ha; Kim, Young Jun; Yoo, Seol Bong; Nam, Kyung Hwa [Presbyterian Medical Center, Seonam University College of Medicine, Jeonju (Korea, Republic of)

    2016-06-15

    F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography scan has been used for the diagnosis, assessment of treatment response, and follow-up of various neoplasms. Proliferating trichilemmal cyst or tumor (PTT) is a rare neoplasm, originated from the outer root sheath of a hair follicle. Because this tumor has unpredictable biological and clinical behavior, the long-term clinical follow-up is necessary to detect metastasis or recurrence. We reported a case of recurrent malignant PTT on scalp that showed increased FDG uptake.

  13. Spectrum of fluorodeoxyglucose-positron emission tomography/computed tomography and magnetic resonance imaging findings of ovarian tumors.

    Science.gov (United States)

    Kitajima, Kazuhiro; Ueno, Yoshiko; Maeda, Tetsuo; Murakami, Koji; Kaji, Yasushi; Kita, Masato; Suzuki, Kayo; Sugimura, Kazuro

    2011-11-01

    The purpose of this article is to review fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) and magnetic resonance imaging (MRI) findings in a variety of benign, malignant, and borderline malignant ovarian tumors. It is advantageous to become familiar with the wide variety of FDG-PET/CT findings of this entity. Benign ovarian tumors generally have faint uptake, whereas endometriomas, fibromas, and teratomas show mild to moderate uptake. Malignant ovarian tumors generally have intense uptake, whereas tumors with a small solid component often show minimal uptake.

  14. Positron emission tomography/computed tomography and biomarkers for early treatment response evaluation in metastatic colon cancer

    DEFF Research Database (Denmark)

    Engelmann, Bodil E.; Loft, Annika; Kjær, Andreas

    2014-01-01

    BACKGROUND: Treatment options for metastatic colon cancer (mCC) are widening. We prospectively evaluated serial 2-deoxy-2-[18F]fluoro-d-glucose positron-emission tomography/computed tomography (PET/CT) and measurements of tissue inhibitor of metalloproteinases-1 (TIMP-1), carcinoembryonic antigen...... evaluated by PET/CT before treatment, after one and four treatment series. Morphological and metabolic response was independently assessed according to Response Evaluation Criteria in Solid Tumors and European Organization for Research and Treatment of Cancer PET criteria. Plasma TIMP-1, plasma u...

  15. Contrast-enhanced 18F-fluorodeoxyglucose positron emission tomography/computed tomography in immunoglobulin G4-related retroperitoneal fibrosis

    International Nuclear Information System (INIS)

    Sharma, Punit; Chatterjee, Piyali

    2015-01-01

    Immunoglobulin G4 (IgG4)-related disease encompasses a wide variety of immune disorders previously thought be distinct. IgG4-related retroperitoneal fibrosis is one such entity. Metabolic imaging with 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) can be useful in the management of IgG4-related retroperitoneal fibrosis. We here discuss the case of 63-year-old male with IgG4-related retroperitoneal fibrosis and the role, 18 F-FDG PET/CT played in his management

  16. 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

  17. Convergence analysis of a relaxed EM algorithm with uses in emission tomography

    International Nuclear Information System (INIS)

    Iusem, A.N.

    1989-01-01

    This work describes the Position Emission tomography technique this technique consists of introducing in the organism a radioactive substance and determining its concentration in each part of the body by measuring its emission in a detectors ring. (A.C.A.S.)

  18. Silicon photomultipliers for positron emission tomography detectors with depth of interaction encoding capability

    International Nuclear Information System (INIS)

    Taghibakhsh, Farhad; Reznik, Alla; Rowlands, John A.

    2011-01-01

    Silicon photomultipliers (SiPMs) are receiving increasing attention in the field of positron emission tomography (PET) detectors. Compared to photomultiplier tubes, they offer novel detector configurations for the extraction of depth of interaction (DOI) information, or enable emerging medical imaging modalities such as simultaneous PET-magnetic resonant imaging (MRI). In this article, we used 2x2x20 mm 3 LYSO scintillator crystals coupled to SiPMs on both ends (dual-ended readout configuration) to evaluate the detector performance for DOI-PET applications. We investigated the effect of scintillator crystal surface finishing on sensitivity and resolution of DOI, as well as on energy and timing resolution. Measurements indicate DOI sensitivity and resolution of 7.1% mm -1 and 2.1±0.6 mm for saw-cut, and 1.3% mm -1 and 9.0±1.5 mm, for polished scintillator crystals, respectively. Energy resolution varies from 19% when DOI is in the center, to 15% with DOI at either end of the saw-cut crystal, while it remains constant at ∼14% for polished scintillators. Based on our results we conclude that 2x2x20 mm 3 saw-cut (without any special side wall polishing) LYSO crystals coupled to 2x2 mm 2 silicon photomultipliers are optimal for isotropic 2 mm resolution DOI-PET applications.

  19. 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

  20. Practical implementation of tetrahedral mesh reconstruction in emission tomography

    Science.gov (United States)

    Boutchko, R.; Sitek, A.; Gullberg, G. T.

    2013-05-01

    This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio

  1. Practical implementation of tetrahedral mesh reconstruction in emission tomography

    International Nuclear Information System (INIS)

    Boutchko, R; Gullberg, G T; Sitek, A

    2013-01-01

    This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio

  2. Positron Emission Tomography Imaging Using Radiolabeled Inorganic Nanomaterials

    Science.gov (United States)

    Sun, Xiaolian; Cai, Weibo; Chen, Xiaoyuan

    2015-01-01

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

  3. [Human positron emission tomography with oral 11C-vinpocetine].

    Science.gov (United States)

    Vas, Adám; Christer, Halldin; Sóvágó, Judit; Johan, Sandell; Cselényi, Zsolt; Kiss, Béla; Kárpáti, Egon; Lars, Farde; Gulyás, Balázs

    2003-11-16

    Positron emission tomography (PET) is a useful tool for the investigation of certain physiological changes and for the evaluation of the distribution, and receptor binding of drugs labelled with positron emitting isotopes. Vinpocetine (ethyl-apovincaminate) is a neuroprotective drug widely used in the prevention and treatment of cerebrovascular diseases. In the clinical practice vinpocetine is usually administered to the patients in intravenous infusion followed by long-term oral treatment. Until presently human data describing vinpocetine's kinetics and brain distribution came from ex vivo (blood, plasma, liquor) and post mortem (brain autoradiography) measurements. The authors wished to investigate the kinetics and distribution of vinpocetine in the brain and body after oral administration with PET in order to prove, that PET is useful in the non-invasive in vivo determination of these parameters. Vinpocetine was labelled with carbon-11 and the radioactivity was measured by PET in the stomach, liver, brain, colon and kidneys in healthy male volunteers. The radioactivity in the blood and urine was also determined. After oral administration, [11C]vinpocetine appeared immediately in the stomach and within minutes in the liver and the blood. In the blood the level of radioactivity continuously increased until the end of the measurement period, whereas the fraction of the unchanged mother compound decreased. Radioactivity uptake and distribution in the brain were demonstrable from the tenth minute after the oral administration of the labelled drug (average maximum uptake: 0.7% of the administered total dose). Brain distribution was heterogeneous (with preferences in the thalamus, basal ganglia and occipital cortex), similar to the distribution previously reported by the authors after intravenous administration. Vinpocetine, administered orally to human volunteers, readily entered the bloodstream from the stomach and the gastrointestinal tract and thereafter passed the

  4. The Comparison of Computed Tomography Perfusion, Contrast-Enhanced Computed Tomography and Positron-Emission Tomography/Computed Tomography for the Detection of Primary Esophageal Carcinoma.

    Science.gov (United States)

    Genc, Berhan; Kantarci, Mecit; Sade, Recep; Orsal, Ebru; Ogul, Hayri; Okur, Aylin; Aydin, Yener; Karaca, Leyla; Eroğlu, Atilla

    2016-01-01

    The purpose of this study was to investigate the efficiency of computed tomography perfusion (CTP), contrast-enhanced computed tomography (CECT) and 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron-emission tomography (PET/CT) in the diagnosis of esophageal cancer. This prospective study consisted of 33 patients with pathologically confirmed esophageal cancer, 2 of whom had an esophageal abscess. All the patients underwent CTP, CECT and PET/CT imaging and the imaging findings were evaluated. Sensitivity, specificity and positive and negative predictive values were calculated for each of the 3 imaging modalities relative to the histological diagnosis. Thirty-three tumors were visualized on CTP, 29 on CECT and 27 on PET/CT. Six tumors were stage 1, and 2 and 4 of these tumors were missed on CECT and PET/CT, respectively. Significant differences between CTP and CECT (p = 0.02), and between CTP and PET/CT (p = 0.04) were found for stage 1 tumors. Values for the sensitivity, specificity and positive and negative predictive values on CTP were 100, 100, 100 and 100%, respectively. Corresponding values on CECT were 93.94, 0, 93.94 and 0%, respectively, and those on PET/CT were 87.88, 0, 93.55 and 0%, respectively. Hence, the sensitivity, specificity and positive and negative predictive values of CTP were better than those of CECT and PET/CT. CTP had an advantage over CECT and PET/CT in detecting small lesions. CTP was valuable, especially in detecting stage 1 tumors. © 2016 S. Karger AG, Basel.

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

    Science.gov (United States)

    2011-02-03

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

  6. Diagnostic performance of fluorodeoxyglucose positron emission tomography/magnetic resonance imaging fusion images of gynecological malignant tumors. Comparison with positron emission tomography/computed tomography

    International Nuclear Information System (INIS)

    Nakajo, Kazuya; Tatsumi, Mitsuaki; Inoue, Atsuo

    2010-01-01

    We compared the diagnostic accuracy of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and PET/magnetic resonance imaging (MRI) fusion images for gynecological malignancies. A total of 31 patients with gynecological malignancies were enrolled. FDG-PET images were fused to CT, T1- and T2-weighted images (T1WI, T2WI). PET-MRI fusion was performed semiautomatically. We performed three types of evaluation to demonstrate the usefulness of PET/MRI fusion images in comparison with that of inline PET/CT as follows: depiction of the uterus and the ovarian lesions on CT or MRI mapping images (first evaluation); additional information for lesion localization with PET and mapping images (second evaluation); and the image quality of fusion on interpretation (third evaluation). For the first evaluation, the score for T2WI (4.68±0.65) was significantly higher than that for CT (3.54±1.02) or T1WI (3.71±0.97) (P<0.01). For the second evaluation, the scores for the localization of FDG accumulation showing that T2WI (2.74±0.57) provided significantly more additional information for the identification of anatomical sites of FDG accumulation than did CT (2.06±0.68) or T1WI (2.23±0.61) (P<0.01). For the third evaluation, the three-point rating scale for the patient group as a whole demonstrated that PET/T2WI (2.72±0.54) localized the lesion significantly more convincingly than PET/CT (2.23±0.50) or PET/T1WI (2.29±0.53) (P<0.01). PET/T2WI fusion images are superior for the detection and localization of gynecological malignancies. (author)

  7. Data on analysis of coronary atherosclerosis on computed tomography and 18F-sodium fluoride positron emission tomography

    Directory of Open Access Journals (Sweden)

    Toshiro Kitagawa

    2017-08-01

    Full Text Available This article contains the data showing illustrative examples of plaque classification on coronary computed tomography angiography (CCTA and measurement of 18F-sodium fluoride (18F-NaF uptake in coronary atherosclerotic lesions on positron emission tomography (PET. We divided the lesions into one of three plaque types on CCTA (calcified plaque, non-calcified plaque, partially calcified plaque. Focal 18F-NaF uptake of each lesion was quantified using maximum tissue-to-background ratio. This article also provides a representative case with a non-calcified coronary plaque detected on CCTA and identified on 18F-NaF PET/non-contrast computed tomography based on a location of a vessel branch as a landmark. These complement the data reported by Kitagawa et al. (2017 [1].

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

    Science.gov (United States)

    Kimizuka, Yoshifumi; Ishii, Makoto; Murakami, Koji; Ishioka, Kota; Yagi, Kazuma; Ishii, Ken; Watanabe, Kota; Soejima, Kenzo; Betsuyaku, Tomoko; Hasegawa, Naoki

    2013-11-14

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

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

    International Nuclear Information System (INIS)

    Kimizuka, Yoshifumi; Hasegawa, Naoki; Ishii, Makoto; Murakami, Koji; Ishioka, Kota; Yagi, Kazuma; Ishii, Ken; Watanabe, Kota; Soejima, Kenzo; Betsuyaku, Tomoko

    2013-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  11. Simultaneous emission transmission tomography using technetium-99m for both emission and transmission

    International Nuclear Information System (INIS)

    Barnden, L.R.; Ong, P.L.; Rowe, C.C.

    1997-01-01

    This phantom study investigates whether attenuation maps from transmission data degraded by increased noise from subtraction of emission counts can still provide useful attenuation correction in the regular and obese chest. Technetium-99m was used for both emission and transmission on a triple head simultaneous emission transmission tomography (Tc-Tc SETT) system. Fanbeam transmission counts were computed by subtracting emission counts estimated from the two parallel collimator heads. Radioactive decay was used to simulate organ counts from injections of 900 and 400 MBq sestamibi for regular and obese chest sizes. Line source activity was 350 MBq. Control attenuation maps were obtained with no emission activity. Noise control included catering for negative and zero transmission counts, pre-filtering and segmentation of mu maps. Pre-filtering was tried before and after subtraction and before and after setting negative pixels to zero. Mean±SD count/pixel at the heart in anterior transmission projections was typically 33±18 for the regular and 1±7 for the obese chest. For the obese chest, pre-filtering before resetting negative counts best preserved mean mu in soft tissue and lung. Tc-Tc SETT mu mean±SD for the regular chest were 0.144±0.012 and 0.058±0.004 for soft tissue and lung and for the obese chest, 0.152±0.075 and 0.059±0.017. The accuracy of the Tc-Tc SETT bullseye plots for the regular chest was the same as with control map attenuation correction and 3 times better than with no correction. For the obese chest it was as good as with control map correction only if mu map segmentation was applied. Tc-Tc SETT soft tissue and lung mu in 28 patient studies indicated that segmentation is practical for a wide range of chest sizes. Tc-Tc SETT on a triple-head system offers an accurate, inexpensive method of attenuation correction for the majority of chest sizes. (orig.)

  12. Fluorodeoxyglucose positron emission tomography scan may be helpful in the case of ductal variant prostate cancer when prostate specific membrane antigen ligand positron emission tomography scan is negative

    International Nuclear Information System (INIS)

    McEwan, Louise M.; Wong, David; Yaxley, John

    2017-01-01

    Gallium-68 prostate specific membrane antigen ligand (Ga-68 PSMA) positron emission tomography/computed tomography (PET/CT) scanning is emerging as a useful imaging modality for the staging of suspected and known recurrent or metastatic prostate cancer and in staging of newly diagnosed higher grade prostate cancer. However, we have observed at our institution that in some cases of the more aggressive ductal variant, Ga-68 PSMA uptake has sometimes been poor compared with prominent 18-fluorodeoxyglucose (F-18 FDG) avidity seen in F-18 FDG PET/CT, which would suggest that FDG PET/CT scans are important in staging of ductal pattern prostate cancer.

  13. Distinguishing tumor recurrence from irradiation sequelae with positron emission tomography in patients treated for larynx cancer

    International Nuclear Information System (INIS)

    Greven, K.M.; Williams, D.W. III; Keyes, J.W. Jr.; McGuirt, W.F.; Harkness, B.A.; Watson, N.E. Jr.; Raben, M.; Frazier, L.C.; Geisinger, K.R.; Capellari, J.O.

    1994-01-01

    Distinguishing persistent or recurrent tumor from postradiation edema, or soft tissue/cartilage necrosis in patients treated for carcinoma of the larynx can be difficult. Because recurrent tumor is often submucosal, multiple deep biopsies may be necessary before a diagnosis can be established. Positron emission tomography with 18F-2-fluro-2-deoxglucose (FDG) was studied for its ability to aid in this problem. Positron emission tomography (18FDG) scans were performed on 11 patients who were suspected of having persistent or recurrent tumor after radiation treatment for carcinoma of the larynx. Patients underwent thorough history and physical examinations, scans with computerized tomography, and pathologic evaluation when indicated. Standard uptake values were used to quantitate the FDG uptake in the larynx. The time between completion of radiation treatment and positron emission tomography examination ranged from 2 to 26 months with a median of 6 months. Ten patients underwent computed tomography (CT) of the larynx, which revealed edema of the larynx (six patients), glottic mass (four patients), and cervical nodes (one patient). Positron emission tomography scans revealed increased FDG uptake in the larynx in five patients and laryngectomy confirmed the presence of carcinoma in these patients. Five patients had positron emission tomography results consistent with normal tissue changes in the larynx, and one patient had increased FDG uptake in neck nodes. This patient underwent laryngectomy, and no cancer was found in the primary site, but nodes were pathologically positive. One patient had slightly elevated FDG uptake and negative biopsy results. The remaining patients have been followed for 11 to 14 months since their positron emission studies and their examinations have remained stable. In patients without tumor, average standard uptake values of the larynx ranged from 2.4 to 4.7, and in patients with tumor, the range was 4.9 to 10.7. 18 refs., 3 figs., 1 tab

  14. Lung Cancer in Patients With Tuberculous Fibrothorax and Empyema: Computed Tomography and 18F-Fluorodeoxyglucose Positron Emission Tomography Findings.

    Science.gov (United States)

    Xu, Hai; Koo, Hyun Jung; Lee, Han Na; Lim, Soyeoun; Lee, Jae Wook; Choi, Chang-Min; Kim, Mi Young

    The aim of this study was to describe the characteristics of lung cancers in patients with tuberculous fibrothorax or empyema. We retrospectively evaluated 138 consecutive patients with a diagnosis of lung cancer combined with fibrothorax (n = 127) or empyema (n = 11) from January 2005 to May 2015. All patients underwent computed tomography, and 105 underwent F-fluorodeoxyglucose positron emission tomography. Clinical, pathologic, and computed tomography characteristics and maximum standardized uptake values on positron emission tomography of 76 cancers ipsilateral to the fibrothorax or empyema (group 1) were compared with those of 62 contralateral cancers (group 2). The median age at diagnosis of patients was 70 years, with a male-to-female ratio of 8.9:1. The most common type was squamous cell carcinoma (41.3%) followed by adenocarcinoma (39.1%). Most were in the peripheral lung (70.3%), and half abutted the pleura. The median maximum standardized uptake value was 8.9. Tumors in group 1 were larger (median, 48.5 vs 42.8 mm, P = 0.036) and more advanced (T3 or T4) (P = 0.014) than those in group 2. Lung cancers ipsilateral to tuberculous fibrothorax or empyema presented larger and advanced T stages, and the diagnosis could be delayed. The most common type cancer was squamous cell carcinoma.

  15. 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

  16. Use of computed tomography and positron emission tomography/computed tomography for staging of local extent in patients with malignant pleural mesothelioma.

    Science.gov (United States)

    Frauenfelder, Thomas; Kestenholz, Peter; Hunziker, Roger; Nguyen, Thi Dan Linh; Fries, Martina; Veit-Haibach, Patrick; Husmann, Lars; Stahel, Rolf; Weder, Walter; Opitz, Isabelle

    2015-01-01

    The objective of this study was to determine the diagnostic value of computed tomography (CT) and positron emission tomography (PET)/CT for staging of malignant pleural mesothelioma (MPM) in patients undergoing induction chemotherapy. Sixty-two patients (median age, 61 years; female: n = 9) with proven MPM underwent CT after induction chemotherapy. Of these, 28 underwent additional PET/CT. Extrapleural pneumonectomy was performed for pathological TNM staging. Clinical TNM stage was assessed by 3 independent readers. Relative and absolute underestimation and overestimation were compared with pathological tumor stage. Sensitivity, specificity, and accuracy for differentiation between stages T2 and T3 were assessed. Interobserver agreement between the readers was analyzed (κ). Positron emission tomography/CT and CT underestimated T stage in up to 30% of the cases. Positron emission tomography/CT had a higher accuracy for tumor extent compared with CT (PET/CT: 0.92; CT: 0.84). The accuracy for nodal staging was higher for CT than for PET/CT (PET/CT: 0.78; CT: 0.87). Concerning International Mesothelioma Interest Group classification, PET/CT improved the accuracy of preoperative staging compared with CT (PET/CT: 0.91; CT: 0.82). Interobserver agreement was moderate for CT (0.48-0.62) and good for PET/CT (0.64-0.83) for T staging. For nodal staging, interobserver agreement was fair to moderate for CT and good for PET/CT (CT: 0.37-0.51; PET/CT: 0.73-0.76). Positron emission tomography/CT is more accurate and has a lower interobserver variability for clinical intrathoracic staging of MPM compared with CT. Nevertheless PET/CT underestimated tumor stage in a substantial number of cases, showing the need for a more accurate imaging technology or approach.

  17. Computed tomography and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography findings in adrenal candidiasis and histoplasmosis: two cases.

    Science.gov (United States)

    Altinmakas, Emre; Guo, Ming; Kundu, Uma R; Habra, Mouhammed Amir; Ng, Chaan

    2015-01-01

    We report the contrast-enhanced computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography findings in adrenal histoplasmosis and candidiasis. Both demonstrated bilateral hypermetabolic heterogeneous adrenal masses with limited wash-out on delayed CT. Adrenal candidiasis has not been previously reported, nor have the CT wash-out findings in either infection. The adrenal imaging findings are indistinguishable from malignancy, which is more common; but in this setting, physicians should be alert to the differential diagnosis of fungal infections, since it can be equally deadly. Published by Elsevier Inc.

  18. 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

  19. 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...

  20. Image reconstruction from projections and its application in emission computer tomography

    International Nuclear Information System (INIS)

    Kuba, Attila; Csernay, Laszlo

    1989-01-01

    Computer tomography is an imaging technique for producing cross sectional images by reconstruction from projections. Its two main branches are called transmission and emission computer tomography, TCT and ECT, resp. After an overview of the theory and practice of TCT and ECT, the first Hungarian ECT type MB 9300 SPECT consisting of a gamma camera and Ketronic Medax N computer is described, and its applications to radiological patient observations are discussed briefly. (R.P.) 28 refs.; 4 figs

  1. Defining a radiotherapy target with positron emission tomography

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  2. Molecular Imaging of Transporters with Positron Emission Tomography

    Science.gov (United States)

    Antoni, Gunnar; Sörensen, Jens; Hall, Håkan

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

  3. Positron tomography investigation in humans of the local coupling among CBF, oxygen consumption and glucose utilization

    Energy Technology Data Exchange (ETDEWEB)

    Baron, J C; Rougemont, D; Soussaline, F; Crouzel, C; Bousser, M G; Comar, D

    1983-06-01

    Positron tomography investigation of the local coupling among cerebral blood flow (CBF), oxygen consumption (CMRO/sub 2/) and glucose utilization (CMRGlc) was performed in 5 controls and 6 ischemic stroke patients, using oxygen 15 inhalation technique immediately followed by I.V. injection of /sup 18/F-Fluoro-Desoxyglucose (/sup 18/FDG). The normal couple among all 3 variables was demonstrated; but on the other hand significant disruption of either or both the CBF-CMRGlc and the CMRO/sub 2/-CMRGlc couples was found in all 6 stroke patients. Comments on these new findings were made.

  4. Myocardial blood flow quantification for evaluation of coronary artery disease by positron emission tomography, cardiac magnetic resonance imaging, and computed tomography.

    Science.gov (United States)

    Waller, Alfonso H; Blankstein, Ron; Kwong, Raymond Y; Di Carli, Marcelo F

    2014-05-01

    The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging, and computed tomography, and its emerging clinical applications.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  6. Emission computerized-tomography and determination of local brain function

    International Nuclear Information System (INIS)

    Kuhl, D.E.; Alavi, A.; Reivich, M.; Edwards, R.Q.; Fenton, C.A.; Zimmerman, R.A.

    1975-01-01

    Methods for the three dimensional reconstruction of /sup 99m/Tc brain scans are described. The diagnostic advantages of computerized tomography in the localization of brain tumors and in measurements of local cerebral blood flow are discussed. (U.S.)

  7. Single-Photon Emission Computerized Tomography (SPECT in Neuropsychiatry: A Review

    Directory of Open Access Journals (Sweden)

    B. K. Puri

    1992-01-01

    Full Text Available Cranial single-photon emission computerized tomography (SPECT or SPET can now give regional cerebral blood flow images with a resolution approaching that of positron emission tomography (PET. In this paper, the use of high resolution SPECT neuroimaging in neuropsychiatric disorders, including Alzheimer's disease, multi-infarct dementia, Pick's disease, progressive supranuclear palsy, Korsakoff's psychosis, Creutzfeld-Jakob disease, Parkinson's disease, Huntington's disease, schizophrenia, mood disorders, obsessive–compulsive disorder, HIV infection and AIDS is reviewed. Finally, further potential research and clinical uses, based on ligand studies, are outlined.

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  10. Digital signal processing applied to crystal identification in Positron Emission Tomography dedicated to small animals

    International Nuclear Information System (INIS)

    Fontaine, Rejean; Viscogliosi, Nicolas; Semmaoui, Hicham; Belanger, Francois; Lemieux, Francois; Tetrault, Marc-Andre; Michaud, Jean-Baptiste; Berard, Philippe; Cadorette, Jules; Pepin, Catherine M.; Lecomte, Roger

    2007-01-01

    The recent introduction of all-digital electronic architecture in Positron Emission Tomography (PET) scanners, enables new paradigms to be explored for extracting relevant information from the detector signals, such as energy, time and crystal identification. The LabPET TM small animal scanner, which implements free-running 45-MHz sampling directly at the output of the charge sensitive preamplifiers, provides an excellent platform to test such advanced digital algorithms. A real-time identification method, based on an Auto-Regressive Moving-Average (ARMA) scheme, was tested for discriminating between LYSO (t r ∼40 ns) and LGSO (t r ∼65 ns) scintillators in phoswich detectors, coupled to a single Avalanche Photodiode (APD). Even with a low energy threshold of 250 keV applied individually, error rates 10%, typically with conventional analog pulse shape discrimination techniques. Such digital crystal identification techniques can be readily implemented with phoswich detectors for improving spatial resolution in PET, either by increasing crystal pixellization or by mitigating parallax errors through depth-of-interaction determination. It also allows to reduce the event rate presented to the real-time coincidence engine by applying a low energy limit at the crystal granularity and rejecting more Compton photons

  11. Digital signal processing applied to crystal identification in Positron Emission Tomography dedicated to small animals

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, Rejean [Department of Electrical and Computer Engineering, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada)]. E-mail: Rejean.Fontaine@Usherbrooke.ca; Viscogliosi, Nicolas [Department of Electrical and Computer Engineering, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada); Semmaoui, Hicham [Department of Electrical and Computer Engineering, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada); Belanger, Francois [Department of Electrical and Computer Engineering, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada); Lemieux, Francois [Department of Electrical and Computer Engineering, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada); Tetrault, Marc-Andre [Department of Electrical and Computer Engineering, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada); Michaud, Jean-Baptiste [Department of Electrical and Computer Engineering, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada); Berard, Philippe [Department of Nuclear Medicine and Radiobiology, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada); Cadorette, Jules [Department of Nuclear Medicine and Radiobiology, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada); Pepin, Catherine M. [Department of Nuclear Medicine and Radiobiology, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada); Lecomte, Roger [Department of Nuclear Medicine and Radiobiology, Universite de Sherbrooke, 2500 Boul. Universite, Sherbrooke, Que., J1 K 2R1 (Canada)

    2007-02-01

    The recent introduction of all-digital electronic architecture in Positron Emission Tomography (PET) scanners, enables new paradigms to be explored for extracting relevant information from the detector signals, such as energy, time and crystal identification. The LabPET{sup TM} small animal scanner, which implements free-running 45-MHz sampling directly at the output of the charge sensitive preamplifiers, provides an excellent platform to test such advanced digital algorithms. A real-time identification method, based on an Auto-Regressive Moving-Average (ARMA) scheme, was tested for discriminating between LYSO (t{sub r}{approx}40 ns) and LGSO (t{sub r}{approx}65 ns) scintillators in phoswich detectors, coupled to a single Avalanche Photodiode (APD). Even with a low energy threshold of 250 keV applied individually, error rates<4% can be achieved, as compared to >10%, typically with conventional analog pulse shape discrimination techniques. Such digital crystal identification techniques can be readily implemented with phoswich detectors for improving spatial resolution in PET, either by increasing crystal pixellization or by mitigating parallax errors through depth-of-interaction determination. It also allows to reduce the event rate presented to the real-time coincidence engine by applying a low energy limit at the crystal granularity and rejecting more Compton photons.

  12. Ultrafast detection in particle physics and positron emission tomography using SiPMs

    Science.gov (United States)

    Dolenec, R.; Korpar, S.; Križan, P.; Pestotnik, R.

    2017-12-01

    Silicon photomultiplier (SiPM) photodetectors perform well in many particle and medical physics applications, especially where good efficiency, insensitivity to magnetic field and precise timing are required. In Cherenkov time-of-flight positron emission tomography the requirements for photodetector performance are especially high. On average only a couple of photons are available for detection and the best possible timing resolution is needed. Using SiPMs as photodetectors enables good detection efficiency, but the large sensitive area devices needed have somewhat limited time resolution for single photons. We have observed an additional degradation of the timing at very low light intensities due to delayed events in distribution of signals resulting from multiple fired micro cells. In this work we present the timing properties of AdvanSiD ASD-NUV3S-P-40 SiPM at single photon level picosecond laser illumination and a simple modification of the time-walk correction algorithm, that resulted in reduced degradation of timing resolution due to the delayed events.

  13. Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Depresseux, J C; Franck, G., Van Cauwenberge, H.

    1987-06-18

    Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple.

  14. Determination of cerebral metabolic patterns in dementia using positron emission tomography

    International Nuclear Information System (INIS)

    Kuhl, D.E.

    1986-01-01

    With the introduction of the Kety-Schmidt method whole brain measurements of blood flow and metabolism were first applied to normal aged and demented patients. Chronically demented patients were consistently found to have marked reductions in cerebral blood flow, oxygen utilization, and glucose utilization when dementia was severe, and lesser reductions when it was mild. Others found that cerebral blood flow, oxygen utilization, and glucose utilization were decreased in parallel in late stages of Alzheimer's disease (AD) and multiple infarct dementia (MID). The intraarterial /sup 133/Xe method has been used to determine abnormalities in regional cerebral blood flow that correlate with cognitive deficits in patients with organic dementia, mostly Alzheimer's cases. Positron emission tomography (PET) and the /sup 18/F fluorodeoxyglycose (FDG) method have been applied to small numbers of demented patients with advanced AD. In general, decreases were found in global cerebral glucose utilization, but especially in temporal and parietal cortex. Others, using PET and the /sup 15/O/sub 2/ steady-state method, found a coupled decline in global cerebral blood flow and oxygen utilization that was correlated with increasing severity of dementia in both AD and MID, but there was no increase in oxygen extraction ratio, and therefore no evidence to support the existence of a chronic ischemic brain process. In this chapter, the author reviews some of the recent findings at UCLA using PET and the method in the study of normal aging and dementing disorders

  15. Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

    International Nuclear Information System (INIS)

    Depresseux, J.C.; Franck, G.; Van Cauwenberge, H.

    1987-01-01

    Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple [fr

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  17. A Comparison of Endoscopic Ultrasound Guided Biopsy and Positron Emission Tomography with Integrated Computed Tomography in Lung Cancer Staging

    DEFF Research Database (Denmark)

    Larsen, Stine Schmidt; Vilmann, P; Krasnik, K

    2009-01-01

    BACKGROUND AND STUDY AIMS: Exact staging of patients with non-small-cell lung cancer (NSCLC) is important to improve selection of resectable and curable patients for surgery. Positron emission tomography with integrated computed tomography (PET/CT) and endoscopic ultrasound guided fine needle...... aspiration biopsy (EUS-FNA) are new and promising methods, but indications in lung cancer staging are controversial. Only few studies have compared the 2 methods. The aim of this study was to assess and compare the diagnostic values of PET/CT and EUS-FNA for diagnosing advanced lung cancer in patients, who...... had both procedures performed. PATIENTS AND METHODS: 27 patients considered to be potential candidates for resection of NSCLC underwent PET/CT and EUS-FNA. Diagnoses were confirmed either by open thoracotomy, mediastinoscopy or clinical follow-up. Advanced lung cancer was defined as tumour...

  18. Imaging spectrum and pitfalls of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with tuberculosis.

    Science.gov (United States)

    Ito, Kimiteru; Morooka, Miyako; Minamimoto, Ryogo; Miyata, Yoko; Okasaki, Momoko; Kubota, Kazuo

    2013-08-01

    Mycobacterium tuberculosis (TB) is one of the most prominant diseases frequently causing false positive lesions in oncologic surveys using (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), since TB granulomas are composed of activated macrophages and lymphocytes with high affinity for glucose. These pitfalls of (18)F-FDG PET/CT are important for radiologists. Being familiar with (18)F-FDG images of TB could assist in preventing unfavorable clinical results based on misdiagnoses. In addition, (18)F-FDG PET/CT has the advantage of being able to screen the whole body, and can clearly detect harboring TB lesions as high uptake foci. This article details the spectrum and pitfalls of (18)F-FDG PET/CT imaging in TB.

  19. Contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography in solid pseudopapillary neoplasm of the pancreas

    International Nuclear Information System (INIS)

    Santhosh, Sampath; Lakshmanan, Ramesh Kumar; Sonik, Bhavay; Padmavathy, Rajagopalan; Gunaseelan, Rajamani Emmanuel

    2016-01-01

    Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare pancreatic tumor with low malignant potential. It occurs characteristically more often in young women. Radiological and pathological studies have revealed that the tumor is quite different from other pancreatic tumors. Limited information is available in the literature reporting their accumulation of fluorine- 18 fluorodeoxyglucose ( 18 F-FDG) in positron emission tomography/computed tomography (PET/CT). Here, we report a case of pancreatic SPN imaged with contrast-enhanced FDG PET/CT. A percutaneous fine needle aspiration from the metabolically active lesion revealed SPN, and it was confirmed with histopathological results. Recurrence or metastasis was not found after 7 months of follow-up

  20. Benign thyroid and neck lesions mimicking malignancy with false positive findings on positron emission tomography-computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ye Ri; Kim, Shin Young; Lee, Sang Mi [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of); Lee, Deuk Young [Dept. of Surgery, Younsei Angelot Women' s Clinic, Cheonan (Korea, Republic of)

    2017-02-15

    The increasing use of positron emission tomography-computed tomography (PET/CT) has led to the frequent detection of incidental thyroid and neck lesions with increased 18F-deoxyglucose (FDG) uptake. Although lesions with increased FDG uptake are commonly assumed to be malignant, benign lesions may also exhibit increased uptake. The purpose of this pictorial essay is to demonstrate that benign thyroid and neck lesions can produce false-positive findings on PET/CT, and to identify various difficulties in interpretation. It is crucial to be aware that differentiating between benign and malignant lesions is difficult in a considerable proportion of cases, when relying only on PET/CT findings. Correlation of PET/CT findings with additional imaging modalities is essential to avoid misdiagnosis.

  1. Positron emission tomography-computed tomography standardized uptake values in clinical practice and assessing response to therapy.

    Science.gov (United States)

    Kinahan, Paul E; Fletcher, James W

    2010-12-01

    The use of standardized uptake values (SUVs) is now common place in clinical 2-deoxy-2-[(18)F] fluoro-D-glucose (FDG) position emission tomography-computed tomography oncology imaging and has a specific role in assessing patient response to cancer therapy. Ideally, the use of SUVs removes variability introduced by differences in patient size and the amount of injected FDG. However, in practice there are several sources of bias and variance that are introduced in the measurement of FDG uptake in tumors and also in the conversion of the image count data to SUVs. In this article the overall imaging process is reviewed and estimates of the magnitude of errors, where known, are given. Recommendations are provided for best practices in improving SUV accuracy. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Lynch Syndrome Associated Colon Adenocarcinoma Resembling Lymphoma on Fluoro-Deoxyglucose-Positron Emission Tomography/Computed Tomography

    International Nuclear Information System (INIS)

    Aparici, Carina Mari; Win, Aung Zaw

    2015-01-01

    The patient was a 46-year-old Asian male diagnosed with lynch syndrome associated colon adenocarcinoma in the right ascending colon. A presurgical staging 18-fluoro-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) found increased metabolic activity in the cervical, axillary, mediastinal, supraclavicular, para-aortic and mesenteric lymph nodes. This pattern of metastasis was very unusual for lynch syndrome associated colon adenocarcinoma and the involvement of those lymph nodes resembles the pattern of spread of lymphoma. He underwent right hemicolectomy and he was subsequently treated with 12 cycles of folinic acid (leucovorin), fluorouracil (5-FU), irinotecan. A restaging FDG-PET/CT at the end of the chemotherapy showed interval decrease in size and metabolic activity in the affected lymph nodes. FDG-PET/CT is a useful imaging modality in following-up the treatment response in colon adenocarcinoma

  3. 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.

  4. Synthesis of novel ligands for neuro-inflammation imaging using Positron Emission Tomography

    International Nuclear Information System (INIS)

    Cacheux, Fanny

    2016-01-01

    Neuro-inflammation plays an important role in many neuro-degenerative diseases (Alzheimer, Parkinson, Multiple sclerosis..) and recent developments in molecular imaging provide today new insights into the diagnostic and the treatment management of these diseases. Among the existing imaging techniques, the highly sensitive and quantitative nuclear modalities SPECT (single photon emission computed tomography) but especially PET (positron emission tomography) play key roles. My PhD program is devoted to the design and synthesis of novel radioligands, all dedicated to the imaging of specific targets and processes linked to neuro-inflammation. For this, PET and the short-lived positron-emitter fluorine-18 (T 1/2 : 109.8 min) remain the main focuses. The project has been divided into two sections, the first one concentrates on the development of novel ligands targeting the Translocator Protein 18 kDa (TSPO). Indeed, this target is today recognized as an early bio-marker of neuro-inflammatory processes and PK11195, an isoquinoline carboxamide labelled with carbon-11, was, in the late 80's, the first reported PET-radioligand. More recently, new compounds, all belonging to different chemical classes, have emerged and notably the pyrazolopyrimidine acetamide [ 11 C]DPA-713 and the pyridazinoindole acetamide [ 11 C]SSR180575. Within the first section of my PhD, novel derivatives of both DPA-713 and SSR180575 have been synthesized and in vitro characterized. Dedicated precursors for labelling were also developed for the most promising candidates, and radiolabelling has been performed. Some results have been presented at the 21. International Symposium on Radiopharmaceutical Sciences (Columbia, MO, USA - May 26-31, 2015).The second part of my PhD, deals with the development of ligands for alternative targets to the TSPO, like the type-2 cannabinoid receptor (CB2R) and the purinergic P2Y14/P2Y12 receptors, the latter emerging today as a hot topic for imaging opportunities

  5. (18)F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Malignancies of the Thyroid and in Head and Neck Squamous Cell Carcinoma

    DEFF Research Database (Denmark)

    Lauridsen, Jeppe Kiilerich; Rohde, Max; Thomassen, Anders

    2015-01-01

    18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is a valuable diagnostic tool in a spectrum of malignant and benign conditions, because of a high sensitivity to detect even very small lesions with increased metabolism. This review focuses on the use of FDG...

  6. Patient study of in vivo verification of beam delivery and range, using positron emission tomography and computed tomography imaging after proton therapy

    NARCIS (Netherlands)

    Parodi, Katia; Paganetti, Harald; Shih, Helen A; Michaud, Susan; Loeffler, Jay S; DeLaney, Thomas F; Liebsch, Norbert J; Munzenrider, John E; Fischman, Alan J; Knopf, Antje; Bortfeld, Thomas

    2007-01-01

    PURPOSE: To investigate the feasibility and value of positron emission tomography and computed tomography (PET/CT) for treatment verification after proton radiotherapy. METHODS AND MATERIALS: This study included 9 patients with tumors in the cranial base, spine, orbit, and eye. Total doses of 1.8-3

  7. The added value of 18F-fluorodeoxyglucose positron emission tomography computed tomography in patients with neck lymph node metastases from an unknown primary malignancy.

    Science.gov (United States)

    Prowse, S J B; Shaw, R; Ganeshan, D; Prowse, P M; Hanlon, R; Lewis-Jones, H; Wieshmann, H

    2013-08-01

    The search for a primary malignancy in patients with a metastatic cervical lymph node is challenging yet ultimately of utmost clinical importance. This study evaluated the efficacy of positron emission tomography computed tomography in detecting the occult primary, within the context of a tertiary referral centre head and neck cancer multidisciplinary team tumour board meeting. Thirty-two patients (23 men and 9 women; mean and median age, 61 years) with a metastatic cervical lymph node of unknown primary origin, after clinical examination and magnetic resonance imaging, underwent positron emission tomography computed tomography. The primary tumour detection rate was 50 per cent (16/32). Positron emission tomography computed tomography had a sensitivity of 94 per cent (16/17) and a specificity of 67 per cent (10/15). Combining these results with those of 10 earlier studies of similar patients gave an overall detection rate of 37 per cent. Positron emission tomography computed tomography has become an important imaging modality. To date, it has the highest primary tumour detection rate, for head and neck cancer patients presenting with cervical lymph node metastases from an unknown primary.

  8. Routine Bone Marrow Biopsy Has Little or No Therapeutic Consequence for Positron Emission Tomography/Computed Tomography-Staged Treatment-Naive Patients With Hodgkin Lymphoma

    DEFF Research Database (Denmark)

    El-Galaly, Tarec Christoffer; d'Amore, Francesco; Mylam, Karen Juul

    2012-01-01

    PURPOSETo investigate whether bone marrow biopsy (BMB) adds useful information to [(18)F]fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) staging in patients with Hodgkin lymphoma (HL). PATIENTS AND METHODSNewly diagnosed patients with HL undergoing a pretherapeu...

  9. Occult primary tumors of the head and neck: accuracy of thallium 201 single-photon emission computed tomography and computed tomography and/or magnetic resonance imaging

    NARCIS (Netherlands)

    van Veen, S. A.; Balm, A. J.; Valdés Olmos, R. A.; Hoefnagel, C. A.; Hilgers, F. J.; Tan, I. B.; Pameijer, F. A.

    2001-01-01

    To determine the accuracy of thallium 201 single-photon emission computed tomography (thallium SPECT) and computed tomography and/or magnetic resonance imaging (CT/MRI) in the detection of occult primary tumors of the head and neck. Study of diagnostic tests. National Cancer Institute, Amsterdam,

  10. Coexistence of atrial myxoma and lung cancer on fluorodeoxyglucose positron emission tomography/computed tomography: The impact of distinct fluorodeoxyglucose uptake pattern on differential diagnosis

    International Nuclear Information System (INIS)

    Koc, Kevser; Aras, Mustafa; Inanir, Sabahat

    2014-01-01

    The information regarding fluorodeoxyglucose (FDG) uptake in benign and malignant cardiac tumors is limited in the literature and most of the currrently available data were derived from single case reports. Herein we reported coexistence of atrial myxoma and lung cancer on FDG positron emission tomography/computed tomography with the aim of emphasizing the importance of distinct FDG uptake pattern on differential diagnosis

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

    Energy Technology Data Exchange (ETDEWEB)

    Pellat, J; Hommel, M

    1987-06-18

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

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

    International Nuclear Information System (INIS)

    Pellat, J.; Hommel, M.

    1987-01-01

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

  13. Quantitative single-photon emission tomography for cerebral flow and receptor distribution imaging

    International Nuclear Information System (INIS)

    Budinger, T.F.

    1985-01-01

    Recently there has been renewed interest in single-photon emission tomography for two major reasons. First, correction methods have been devised for attenuation compensation, nonuniform resolution, and scattered radiation. Second, new radiopharmaceuticals with 1-5% uptake in the brain provide adequate statistics for quantitative imaging of flow using properly designed single-photon tomographic instruments. The lack of commercially available instruments designed specifically to optimize sensitivity for a resolution finer than 15 mm full width at half maximum (FWHM) seems now to be the major deterrent to the widespread use of single-photon emission tomography. But it appears now that some development in this respect also might lead to a widespread renewed interest in single-photon tomography of the brain. Major activities of the past few years can be placed in three distinct categories of instrumentation and methodology

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

    International Nuclear Information System (INIS)

    Labas, R.

    2007-01-01

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

  15. MRI and {sup 18}F-fluorodeoxyglucose positron emission tomography in hemimegalencephaly

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, K.T.; Liebig, T.; Hosten, N. [Departments of Radiology and Nuclear Medicine, Virchow-Klinikum, Charite, Berlin (Germany); Amthauer, H.; Farahati, J.; Felix, R. [Departments of Radiology and Nuclear Medicine, Virchow-Klinikum, Charite, Berlin (Germany); PET-Centre Berlin, Virchow-Klinikum, Charite, Humboldt-University, Berlin (Germany); Etou, A.; Lehmann, T.N. [Department of Neurosurgery, Virchow-Klinikum, Charite, Humboldt-University, Berlin (Germany)

    2000-10-01

    We report hemimegalencephaly in a 44-year-old woman with mental retardation, epilepsy and a mild hemiparesis. In addition to typical findings on MRI, 2-deoxy-2[{sup 18}F]fluorodeoxyglucose positron-emission tomography (PET) demonstrated glucose hypometabolism of the affected hemisphere. The results of PET have been coregistered with morphological information from the MRI studies by image fusion. (orig.)

  16. Synthesis and biodistribution of [C-11]procaterol, a beta(2)-adrenoceptor agonist for positron emission tomography

    NARCIS (Netherlands)

    Visser, TJ; van der Wouden, EA; van Waarde, A; Doze, P; Elsinga, PH; Vaalburg, W

    The potent, subtype-selective radioligand (+/-)-erythro-5-(1-hydroxy-2-[C-11]isopropyl-aminobutyl)-8-hydroxy-carbostyril ([C-11]procaterol) was synthesized and evaluated for visualization of pulmonary beta(2)-adrenoceptors with positron emission tomography (PET). Procaterol was labelled by reductive

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  18. 77 FR 8262 - Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    Science.gov (United States)

    2012-02-14

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-D-0081] Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug...

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

    DEFF Research Database (Denmark)

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

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

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

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

    DEFF Research Database (Denmark)

    Danielsen, Maria; Højgaard, Liselotte; Kjær, Andreas

    2014-01-01

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

  5. 18F-fluorodeoxyglucose positron emission tomography predicts survival of patients with neuroendocrine tumors

    DEFF Research Database (Denmark)

    Binderup, Tina; Knigge, Ulrich; Loft, Annika

    2010-01-01

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

  6. Monitoring of herpes simplex virus thymidine kinase enzyme activity using positron emission tomography

    NARCIS (Netherlands)

    Hospers, GAP; Calogero, Anna; van Waarde, A; Doze, P; Vaalburg, W; Mulder, NH; de Vries, EFJ

    2000-01-01

    9-[(1-[F-18]Fluoro-3-hydroxy-2-propoxy)methyl]guanine ([F-18]FHPG) wasevaluated as a tracer for noninvasive positron emission tomography (PET) imaging of herpes simplex virus type 1 thymidine kinase (HSV-tk) gene expression. C6 rat glioma cells with and without the HSV-tk gene were incubated with

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

    NARCIS (Netherlands)

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

    2009-01-01

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

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

    Science.gov (United States)

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

    2017-08-01

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

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

    International Nuclear Information System (INIS)

    Lopez D, F.A.

    2005-01-01

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

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

    NARCIS (Netherlands)

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

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

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

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

    DEFF Research Database (Denmark)

    Roivainen, Anne; Naum, Alexandru; Nuutinen, Heikki

    2013-01-01

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

  13. Investigating Serotonergic Function Using Positron Emission Tomography: Overview and Recent Findings

    NARCIS (Netherlands)

    Veltman, D.J.; Ruhe, H.G.; Booij, J.

    2010-01-01

    Mono-aminergic neurotransmitters, in particular serotonin (5-HT), are involved in regulating a large number of psychological and physiological functions, and abnormal 5-HT transmission has been implicated in a wide variety of neuropsychiatric disorders. Positron emission tomography (PET) is a

  14. Realization of a gamma emission tomography by a servo-controlled camera and bed

    International Nuclear Information System (INIS)

    Parmentier, M.; Gunzman, D.; Bidet, R.

    1979-01-01

    A gamma-camera and a whole-body bed were connected to a minicomputer which controlled automatically their movements. By combining horizontal displacement of the bed with vertical displacement and rotation of the camera we were able to obtain the equivalent of camera rotation around the bed. This method provides an inexpensive way of realizing gamma emission tomography [fr

  15. A Monte Carlo simulation of the possible use of Positron Emission Tomography in proton radiotherapy

    International Nuclear Information System (INIS)

    Del Guerra, Alberto; Di Domenico, Giovanni; Gambaccini, Mauro; Marziani, Michele

    1994-01-01

    We have used the Monte Carlo technique to evaluate the applicability of Positron Emission Tomography to in vivo dosimetry for proton radiotherapy. A fair agreement has been found between Monte Carlo results and experimental data. The simulation shows that PET can be useful especially for in vivo Bragg's peak localization. ((orig.))

  16. Characteristics of a single photon emission tomography system with a wide field gamma camera

    International Nuclear Information System (INIS)

    Mathonnat, F.; Soussaline, F.; Todd-Pokropek, A.E.; Kellershohn, C.

    1979-01-01

    This text summarizes a work study describing the imagery possibilities of a single photon emission tomography system composed of a conventional wide field gamma camera, connected to a computer. The encouraging results achieved on the various phantoms studied suggest a significant development of this technique in clinical work in Nuclear Medicine Departments [fr

  17. The early years of single photon emission computed tomography (SPECT): an anthology of selected reminiscences

    International Nuclear Information System (INIS)

    Jaszczak, Ronald Jack

    2006-01-01

    The origin of SPECT can be found in pioneering experiments on emission tomography performed approximately 50 years ago. This historical review consists of a compilation of first person recollections from nine trailblazing scientists who shaped the early years of SPECT instrumentation during the 1960s and 1970s. (review)

  18. The early years of single photon emission computed tomography (SPECT): an anthology of selected reminiscences

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, Ronald Jack [Duke University Medical Center, Durham, NC 27710 (United States)

    2006-07-07

    The origin of SPECT can be found in pioneering experiments on emission tomography performed approximately 50 years ago. This historical review consists of a compilation of first person recollections from nine trailblazing scientists who shaped the early years of SPECT instrumentation during the 1960s and 1970s. (review)

  19. REVIEW: The early years of single photon emission computed tomography (SPECT): an anthology of selected reminiscences

    Science.gov (United States)

    Jaszczak, Ronald Jack

    2006-07-01

    The origin of SPECT can be found in pioneering experiments on emission tomography performed approximately 50 years ago. This historical review consists of a compilation of first person recollections from nine trailblazing scientists who shaped the early years of SPECT instrumentation during the 1960s and 1970s.

  20. The early years of single photon emission computed tomography (SPECT): an anthology of selected reminiscences.

    Science.gov (United States)

    Jaszczak, Ronald Jack

    2006-07-07

    The origin of SPECT can be found in pioneering experiments on emission tomography performed approximately 50 years ago. This historical review consists of a compilation of first person recollections from nine trailblazing scientists who shaped the early years of SPECT instrumentation during the 1960s and 1970s.

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  2. Dry coupling for whole-body small-animal photoacoustic computed tomography

    OpenAIRE

    Yeh, Chenghung; Li, Lei; Zhu, Liren; Xia, Jun; Li, Chiye; Chen, Wanyi; Garcia-Uribe, Alejandro; Maslov, Konstantin I.; Wang, Lihong V.

    2017-01-01

    We have enhanced photoacoustic computed tomography with dry acoustic coupling that eliminates water immersion anxiety and wrinkling of the animal and facilitates incorporating complementary modalities and procedures. The dry acoustic coupler is made of a tubular elastic membrane enclosed by a closed transparent water tank. The tubular membrane ensures water-free contact with the animal, and the closed water tank allows pressurization for animal stabilization. The dry coupler was tested using ...

  3. 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

  4. Comparing staging by positron emission tomography with contrast-enhanced computed tomography and by pathology in head and neck squamous cell carcinoma.

    Science.gov (United States)

    Qualliotine, J R; Mydlarz, W K; Chan, J Y K; Zhou, X; Wang, H; Agrawal, N

    2015-12-01

    This study aimed to evaluate the ability of positron emission tomography with contrast-enhanced computed tomography to correctly stage head and neck squamous cell carcinomas, in comparison with pathological staging. Positron emission tomography computed tomography was used to determine the tumour-node-metastasis classification and overall cancer stage in 85 head and neck squamous cell carcinoma patients who underwent pre-operative imaging using this modality and primary surgery between July 2010 and January 2013. Staging by positron emission tomography computed tomography was retrospectively compared with staging using pathological specimens. Agreement between imaging stage and pathological stage was examined by univariate and multivariate analysis both overall and for each primary tumour site. This imaging modality was 87.5 per cent sensitive and 44.8 per cent specific in identifying regional cervical metastases, and had false positive and false negative rates of 18.8 per cent and 8.2 per cent, respectively. The positive predictive and negative predictive values were 75.4 per cent and 65.0 per cent, respectively. Univariate and multivariate analyses revealed a significant agreement between positron emission tomography computed tomography and pathological node classification in older patients and for the oral cavity primary tumour site. There was significant agreement between both methods in the overall classification only for tumours classified as T3 or greater. Positron emission tomography computed tomography should be used with caution for the pre-operative staging of head and neck cancers because of its high false positive and false negative rates.

  5. DIAGNOSTIC ROLE OF FLUORINE-18 (18F) FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY COMPUTED TOMOGRAPHY IN DETECTING RECURRENT DISEASE IN PATIENTS WITH COLORECTAL CANCER AND ELEVATED CARCINOEMBRYONIC ANTIGEN.

    Science.gov (United States)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Derenzo, S.E.

    1981-08-01

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

  7. Mathematical modeling of three-dimensional images in emission tomography

    International Nuclear Information System (INIS)

    Koblik, Yu.N.; Khugaev, A. V.; Mktchyan, G.A.; Ioannou, P.; Dimovasili, E.

    2002-01-01

    The model of processing results of three-dimensional measurements in positron-emissive tomograph is proposed in this work. The algorithm of construction and visualization of phantom objects of arbitrary shape was developed and its concrete realization in view of program packet for PC was carried out

  8. A Nonparametric Bayesian Approach For Emission Tomography Reconstruction

    International Nuclear Information System (INIS)

    Barat, Eric; Dautremer, Thomas

    2007-01-01

    We introduce a PET reconstruction algorithm following a nonparametric Bayesian (NPB) approach. In contrast with Expectation Maximization (EM), the proposed technique does not rely on any space discretization. Namely, the activity distribution--normalized emission intensity of the spatial poisson process--is considered as a spatial probability density and observations are the projections of random emissions whose distribution has to be estimated. This approach is nonparametric in the sense that the quantity of interest belongs to the set of probability measures on R k (for reconstruction in k-dimensions) and it is Bayesian in the sense that we define a prior directly on this spatial measure. In this context, we propose to model the nonparametric probability density as an infinite mixture of multivariate normal distributions. As a prior for this mixture we consider a Dirichlet Process Mixture (DPM) with a Normal-Inverse Wishart (NIW) model as base distribution of the Dirichlet Process. As in EM-family reconstruction, we use a data augmentation scheme where the set of hidden variables are the emission locations for each observed line of response in the continuous object space. Thanks to the data augmentation, we propose a Markov Chain Monte Carlo (MCMC) algorithm (Gibbs sampler) which is able to generate draws from the posterior distribution of the spatial intensity. A difference with EM is that one step of the Gibbs sampler corresponds to the generation of emission locations while only the expected number of emissions per pixel/voxel is used in EM. Another key difference is that the estimated spatial intensity is a continuous function such that there is no need to compute a projection matrix. Finally, draws from the intensity posterior distribution allow the estimation of posterior functionnals like the variance or confidence intervals. Results are presented for simulated data based on a 2D brain phantom and compared to Bayesian MAP-EM

  9. Emission computer tomography on a Dodewaard mixed oxide fuel pin

    International Nuclear Information System (INIS)

    Buurveld, H.A.; Dassel, G.

    1993-12-01

    A nondestructive technique as well as a destructive PIE technique have been used to verify the results obtained with a newly 8-e computer tomography (GECT) system. Multi isotope Scanning (MIS), electron probe micro analysis (EPMA) and GECT were used on a mixed oxide (MOX) fuel rod from the Dodewaard reactor with an average burnup of 24 MWd/kg fuel. GECT shows migration of Cs to the periphery of fuel pellets and to radial cracks and pores in the fuel, whereas MIS shows Cs migration to pellet interfaces. The EPMA technique appeared not to be useful to show migration of Cs but, it shows the distribution of fission products from Pu. EPMA clearly shows the distribution of fission products from Pu, but did not reveal the Cs-migration. (orig./HP)

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

    Science.gov (United States)

    Vaquero, Juan José; Kinahan, Paul

    2017-01-01

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

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

    Science.gov (United States)

    Vaquero, Juan José; Kinahan, Paul

    2015-01-01

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

  12. Increased fluoro-deoxy-D-glucose uptake on positron emission tomography-computed tomography postbronchoalveolar lavage: a potential cause of radiologic misinterpretation.

    LENUS (Irish Health Repository)

    Leong, Sum

    2011-08-01

    Cytologic analysis of bronchoalveolar lavage (BAL) fluid is used for lung cancer diagnosis. We describe a patient with a history of rectal carcinoma who presented with a new lung mass. BAL was performed, with positron emission tomography-computed tomography the following day. There was mildly increased fluoro-deoxy-D-glucose uptake in areas of the lung parenchyma with new ground-glass opacification. This created ambiguity in staging, clarified 2 weeks later by a computed tomography showing complete resolution of the ground-glass opacity. Clinicians should be aware that BAL may cause increased pulmonary fluoro-deoxy-D-glucose uptake, making accurate radiologic interpretation problematic. We suggest that to optimize positron emission tomography-computed tomography, studies should not be performed within 24 hours of BAL.

  13. Degenerative dementia: nosological aspects and results of single photon emission computed tomography; Les demences degeneratives: aspects nosologiques et resultats de la tomographie d'emission monophotonique

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, B.; Habert, M.O. [Hopital Pitie-Salpetriere, 75 - Paris (France)

    1999-12-01

    Ten years ago, the diagnosis discussion of a dementia case for the old patient was limited to two pathologies: the Alzheimer illness and the Pick illness. During these last years, the frame of these primary degenerative dementia has fallen into pieces. The different diseases and the results got with single photon emission computed tomography are discussed. for example: fronto-temporal dementia, primary progressive aphasia, progressive apraxia, visio-spatial dysfunction, dementia at Lewy's bodies, or cortico-basal degeneration. (N.C.)

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  15. Positron emission tomography with 68Ga-EDTA in the diagnosis and localization of CSF fistulas

    International Nuclear Information System (INIS)

    Bergstrand, G.; Bergstroem, M.; Eriksson, L.; Edner, G.; Widen, L.

    1982-01-01

    Five patients with cerebrospinal fluid (CSF) rhinorrhea were investigated with computed tomography (CT) and positron emission tomography (PET) to localize the site of a CSF fistula. After intrathecal injection of 10 MBq of 68 Ga-EDTA, radioactivity was demonstrated in the basal cisterns. In three cases, the site of the fistula was visualized with PET. It is not always possible to demonstrate a CSF leakage with CT cisternography (CTC) using metrizamide, particularly in cases with minute fistulas or intermittent CSF rhinorrhea. With further experience and improved PET techniques, it may be possible to detect even very small fistulas

  16. Positron Emission Tomography Particle tracking using cluster analysis

    International Nuclear Information System (INIS)

    Gundogdu, O.

    2004-01-01

    Positron Emission Particle Tracking was successfully used in a wide range of industrial applications. This technique primarily uses a single positron emitting tracer particle. However, using multiple particles would provide more comparative information about the physical processes taking place in a system such as mixing or fluidised beds. In this paper, a unique method that enables us to track more than one particle is presented. This method is based on the midpoint of the closest distance between two trajectories or coincidence vectors. The technique presented in this paper employs a clustering method

  17. Positron Emission Tomography Particle tracking using cluster analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gundogdu, O. [University of Birmingham, School of Physics and Astronomy, Birmingham, B15 2TT (United Kingdom)]. E-mail: o.gundogdu@surrey.ac.uk

    2004-12-01

    Positron Emission Particle Tracking was successfully used in a wide range of industrial applications. This technique primarily uses a single positron emitting tracer particle. However, using multiple particles would provide more comparative information about the physical processes taking place in a system such as mixing or fluidised beds. In this paper, a unique method that enables us to track more than one particle is presented. This method is based on the midpoint of the closest distance between two trajectories or coincidence vectors. The technique presented in this paper employs a clustering method.

  18. Positron emission tomography studies of central receptors in humans

    International Nuclear Information System (INIS)

    Baron, J.C.; Maziere, B.

    1986-01-01

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

  19. Nuclear medicine and positron emission tomography: An overview

    International Nuclear Information System (INIS)

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

    1994-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  1. SPECT: Theoretical aspecte and evolution of emission computed axial tomography

    International Nuclear Information System (INIS)

    Brunol, J.; Nuta, V.

    1981-01-01

    We have detailed certain of the elements of 3-D image reconstruction from axial projections. Two of the aspects specific to nuclear medicine have been analysed namely self-absorption and statistics. In our view, the development of ECAT in the months to come must hence proceed in two essential directions: - application to dynamic cardiac imagery (multigated). Results of this type have been obtained over 8 months in the Radioisotope Service of Cochin Hospital in Paris. It must be stressed here that the number of images to be processed then becomes considerable (multiplication by the gate factor yielding more than 100 images), the more the statistics are reduced due to the fact of the temporal separation. The obtaining of good image quality requires sophisticated quadri-dimensional processing. It follows that the computing times, with all the mini-computers available in nuclear medicine, then become much too great to envisage really application in hospital routine (several hours of computing). This is the reason why we connected an array processor with the IMAC system. This very powerful system (several tens of times the power of a mini-computer) will reduce the time of such computing to less than 10 minutes. New elements can be introduced into the reconstruction algorithm (static case opposite the foregoing one). These important elements of improvement are to the detriment of space and hence of computing time. Here again, the use of an array processor appears indispensable. It is to recall that the ECAT is today a currently used method, the theoretical analyses that it has necessitated have opened the way to new effective methods of tomography by 'Slanted Hole'. (orig.) [de

  2. 18F-fluorodeoxyglucose positron emission tomography in colorectal cancer: value in primary staging and follow-up

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  3. Computer tomography, magnetic resonance imaging, and positron emission tomography or positron emission tomography/computer tomography for detection of metastatic lymph nodes in patients with ovarian cancer: A meta-analysis

    International Nuclear Information System (INIS)

    Yuan Ying; Gu Zhaoxiang; Tao Xiaofeng; Liu Shiyuan

    2012-01-01

    Objectives: To compare the diagnostic performances of computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography (PET or PET/CT) for detection of metastatic lymph nodes in patients with ovarian cancer. Methods: Relevant studies were identified with MEDLINE and EMBASE from January 1990 to July 2010. We estimated the weighted summary sensitivities, specificities, OR (odds ratio), and summary receiver operating characteristic (sROC) curves of each imaging technique and conducted pair-wise comparisons using the two-sample Z-test. Meta-regression, subgroup analysis, and funnel plots were also performed to explain the between-study heterogeneity. Results: Eighteen eligible studies were included, with a total of 882 patients. PET or PET/CT was a more accurate modality (sensitivity, 73.2%; specificity, 96.7%; OR [odds ratio], 90.32). No significant difference was detected between CT (sensitivity, 42.6%; specificity, 95.0%; OR, 19.87) and MR imaging (sensitivity, 54.7%; specificity, 88.3%; OR, 12.38). Meta-regression analyses and subgroup analyses revealed no statistical difference. Funnel plots with marked asymmetry suggested a publication bias. Conclusion: FDG-PET or FDG-PET/CT is more accurate than CT and MR imaging in the detection of lymph node metastasis in patients with ovarian cancer.

  4. Resting state rCBF mapping with single-photon emission tomography and positron emission tomography: magnitude and origin of differences

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, C.; Kimiaei, S.; Larsson, S.A. [Section of Nuclear Medicine, Department of Hospital Physics, Karolinska Hospital and Department of Medical Radiation Physics, Stockholm University, Stockholm (Sweden); Pagani, M. [Institute of Experimental Medicine, CNR, Rome (Italy); Ingvar, M. [Section of Cognitive Neurophysiology, Karolinska Hospital, Stockholm (Sweden); Thurfjell, L. [Center of Image Analysis, Uppsala University, Uppsala (Sweden); Jacobsson, H. [Department of Diagnostic Radiology, Karolinska Hospital, Stockholm (Sweden)

    1998-02-01

    Single-photon emission tomography (SPET), using technetium-99m hexamethylpropylene amine oxime, and positron emission tomography (PET), using oxygen-15 butanol were compared in six healthy male volunteers with regard to the mapping of resting state regional cerebral blood flow (rCBF). A computerized brain atlas was utilized for 3D regional analyses and comparison of 64 selected and normalized volumes of interest (VOIs). The normalized mean rCBF values in SPET, as compared to PET, were higher in most of the Brodmann areas in the frontal and parietal lobes (4.8% and 8.7% respectively). The average differences were small in the temporal (2.3%) and occipital (1.1%) lobes. PET values were clearly higher in small VOIs like the thalamus (12.3%), hippocampus (12.3%) and basal ganglia (9.9%). A resolution phantom study showed that the in-plane SPET/PET system resolution was 11.0/7.5 mm. In conclusion, SPET and PET data demonstrated a fairly good agreement despite the superior spatial resolution of PET. The differences between SPET and PET rCBF are mainly due to physiological and physical factors, the data processing, normalization and co-registration methods. In order to further improve mapping of rCBF with SPET it is imperative not only to improve the spatial resolution but also to apply accurate correction techniques for scatter, attenuation and non-linear extraction. (orig.) With 6 figs., 3 tabs., 23 refs.

  5. Resting state rCBF mapping with single-photon emission tomography and positron emission tomography: magnitude and origin of differences

    International Nuclear Information System (INIS)

    Jonsson, C.; Kimiaei, S.; Larsson, S.A.; Pagani, M.; Ingvar, M.; Thurfjell, L.; Jacobsson, H.

    1998-01-01

    Single-photon emission tomography (SPET), using technetium-99m hexamethylpropylene amine oxime, and positron emission tomography (PET), using oxygen-15 butanol were compared in six healthy male volunteers with regard to the mapping of resting state regional cerebral blood flow (rCBF). A computerized brain atlas was utilized for 3D regional analyses and comparison of 64 selected and normalized volumes of interest (VOIs). The normalized mean rCBF values in SPET, as compared to PET, were higher in most of the Brodmann areas in the frontal and parietal lobes (4.8% and 8.7% respectively). The average differences were small in the temporal (2.3%) and occipital (1.1%) lobes. PET values were clearly higher in small VOIs like the thalamus (12.3%), hippocampus (12.3%) and basal ganglia (9.9%). A resolution phantom study showed that the in-plane SPET/PET system resolution was 11.0/7.5 mm. In conclusion, SPET and PET data demonstrated a fairly good agreement despite the superior spatial resolution of PET. The differences between SPET and PET rCBF are mainly due to physiological and physical factors, the data processing, normalization and co-registration methods. In order to further improve mapping of rCBF with SPET it is imperative not only to improve the spatial resolution but also to apply accurate correction techniques for scatter, attenuation and non-linear extraction. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-01-01

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

  7. Development of radioiodinated receptor ligands for cerebral single photon emission tomography

    International Nuclear Information System (INIS)

    Knapp, F.F. Jr.; McPherson, D.W.

    1992-01-01

    In the last decade the use of radiolabeled ligands for the imaging of cerebral receptors by emission computed tomography (ECT) has seen rapid growth. The opportunity to routinely perform cerebral single photon emission tomography (SPET) with iodine-123-labeled ligands depends on the availability of receptor ligands into which iodine can be introduced without decreasing the required high target receptor specificity. The use of iodine-123-labeled receptor-specific ligands also depends on the availability of high purity iodine-123 at reasonable costs and the necessary imaging instrumentation. In this paper, the development and current stage of evaluation of various iodine-123-labeled ligands for SPET imaging of dopaminergic, serotonergic and muscarinic acetylcholinergic receptor classes are discussed

  8. {sup 11}C-Methionine positron emission tomography may monitor the activity of encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Kenji; Shiga, Tohru; Manabe, Osamu; Tamaki, Nagara [Department of Nuclear Medicine, Graduate School of Medicine, Hokkaido University, Sapporo (Japan)], E-mail: khirata@med.hokudai.ac.jp; Fujima, Noriyuki [Department of Radiology, Graduate School of Medicine, Hokkaido University, Sapporo (Japan); Usui, Reiko [Department of Nuclear Medicine, Graduate School of Medicine, Hokkaido University, Sapporo (Japan); Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo (Japan); Kuge, Yuji [Central Institute of Isotope Science, Hokkaido University, Sapporo (Japan)

    2012-12-15

    Encephalitis is generally diagnosed by clinical symptoms, cerebrospinal fluid examination, and imaging studies including CT, magnetic resonance imaging (MRI), and perfusion single photon emission tomography (SPECT). However, the role of positron emission tomography (PET) in diagnosis of encephalitis remains unclear. A 49-year-old woman presenting with coma and elevated inflammatory reaction was diagnosed as having encephalitis according to slow activity on electroencephalogram, broad cortical lesion in MR fluid attenuated inversion recovery image, and increased blood flow demonstrated by SPECT. PET revealed increased accumulation of {sup 11}C-methionine (MET) in the affected brain tissues. After the symptom had improved 2 months later, the accumulation of MET as well as the abnormal findings of MR imaging and SPECT was normalized. This case indicated that MET PET may monitor the activity of encephalitis.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-05-01

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

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    International Nuclear Information System (INIS)

    Ohmochi, Yutaka

    1994-01-01

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

  13. Use of antimatter for the in vivo investigation of the brain: positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Syrota, A. [CEA, 75 - Paris (France)

    2002-07-01

    This series of slides presents 3 imaging methods used in medicine: - the single photon emission computed tomography (SPECT), the positron emission tomography (PET), and the functional magnetic resonance imaging (FMRI). The presentation begins with a brief historical description that highlights the narrow link between progress in imaging techniques and the technological development in radiation detection and computer sciences. Another aspect is the parallel and necessary development of isotopic tracers along with imaging techniques. The clinical applications of PET and FMRI concerning either normal brain functions such as calculus or consciousness or diseases affecting the central nervous system such as Parkinson's disease or schizophrenia (trough the study of the pathways of dopamine in the brain) are presented.

  14. Single-photon emission computed tomography in the clinical evaluation of dementia

    International Nuclear Information System (INIS)

    Jagust, W.J.; Reed, B.R.; Budinger, T.F.; Colina, M.

    1987-01-01

    Physiological imaging using positron emission tomography (PET) has been a useful tool in the investigation of dementia. In particular, patterns of cerebral glucose utilization appear to differentiate various types of dementia, with Alzheimer's disease (AD) demonstrating a propensity for hypometabolism to involve the temporoparietal cortex. Single-photon emission computed tomography (SPECT) using new tracers for the measurement of regional cerebral blood flow is a technique with potentially broader clinical availability than PET and thus may provide a practical method of routinely evaluating patients. The authors studied eight patients with AD, four healthy elderly controls, and one patient with multi-infarct dementia (MID) using the tracer 123 I-N-isopropyl-p-iodoamphetamine with SPECT

  15. Derisking the Cu-Mediated 18F-Fluorination of Heterocyclic Positron Emission Tomography Radioligands.

    Science.gov (United States)

    Taylor, Nicholas J; Emer, Enrico; Preshlock, Sean; Schedler, Michael; Tredwell, Matthew; Verhoog, Stefan; Mercier, Joel; Genicot, Christophe; Gouverneur, Véronique

    2017-06-21

    Molecules labeled with fluorine-18 ( 18 F) are used in positron emission tomography to visualize, characterize and measure biological processes in the body. Despite recent advances in the incorporation of 18 F onto arenes, the development of general and efficient approaches to label radioligands necessary for drug discovery programs remains a significant task. This full account describes a derisking approach toward the radiosynthesis of heterocyclic positron emission tomography (PET) radioligands using the copper-mediated 18 F-fluorination of aryl boron reagents with 18 F-fluoride as a model reaction. This approach is based on a study examining how the presence of heterocycles commonly used in drug development affects the efficiency of 18 F-fluorination for a representative aryl boron reagent, and on the labeling of more than 50 (hetero)aryl boronic esters. This set of data allows for the application of this derisking strategy to the successful radiosynthesis of seven structurally complex pharmaceutically relevant heterocycle-containing molecules.

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

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

    International Nuclear Information System (INIS)

    Comar, D.; Baron, J.C.

    1987-01-01

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

  18. Physically corrected forward operators for induced emission tomography: a simulation study

    Science.gov (United States)

    Viganò, Nicola Roberto; Solé, Vicente Armando

    2018-03-01

    X-ray emission tomography techniques over non-radioactive materials allow one to investigate different and important aspects of the matter that are usually not addressable with the standard x-ray transmission tomography, such as density, chemical composition and crystallographic information. However, the quantitative reconstruction of these investigated properties is hindered by additional problems, including the self-attenuation of the emitted radiation. Work has been done in the past, especially concerning x-ray fluorescence tomography, but this has always focused on solving very specific problems. The novelty of this work resides in addressing the problem of induced emission tomography from a much wider perspective, introducing a unified discrete representation that can be used to modify existing algorithms to reconstruct the data of the different types of experiments. The direct outcome is a clear and easy mathematical description of the implementation details of such algorithms, despite small differences in geometry and other practical aspects, but also the possibility to express the reconstruction as a minimization problem, allowing the use of variational methods, and a more flexible modeling of the noise involved in the detection process. In addition, we look at the results of a few selected simulated data reconstructions that describe the effect of physical corrections like the self-attenuation, and the response to noise of the adapted reconstruction algorithms.

  19. Single photon emission computed tomography in lumbar degenerative spondylolisthesis

    International Nuclear Information System (INIS)

    Ito, S.; Muro, T.; Eisenstein, S.

    1998-01-01

    Analysis of single photon emission computed tomographic images and plain X-ray films of the lumbar vertebrae was performed in 15 patients with lumbar spondylosis and 15 patients with lumbar degenerative spondylolisthesis. The facet joint and osteophyte images were observed in particular, and the slipping ratio of spondylolisthetic vertebrae was determined. The slipping ratio of degenerative spondylolisthesis ranged from 11.8 % to 22.3 %. Hot uptake of 99mTc-HMDP by both L4-5 facet joints was significantly greater in the patients with degenerative spondylolisthesis than in those with lumbar spondylosis. The hot uptake by the osteophytes in lumbar spondylosis was nearly uniform among the three inferior segments, L3-4, L4-5 and L5-S, but was localized to the spondylolisthetic vertebrae, L4-5, or L5-S, in the patients with spondylolisthesis. Half of the osteophytes with hot uptake were assigned to the 3rd degree of Nathan's grading. It was suggested that stress was localized to the slipping vertebrae and their facet joints in patients with lumbar degenerative spondylolisthesis. (author)

  20. PETRIC - A positron emission tomography readout integrated circuit

    Energy Technology Data Exchange (ETDEWEB)

    Pedrali-Noy, Marzio; Gruber, Gregory; Krieger, Bradley; Mandelli, Emmanuele; Meddeler, Gerrit; Moses, William; Rosso, Valeria

    2000-11-05

    We present architecture, critical design issues and performance measurements of PETRIC, a 64-channel mixed signal front-end integrated circuit (IC) for reading out a photodiode (PD) array coupled with LSO scintillator crystals for a medical imaging application (PET). Each channel consists of a low noise charge sensitive pre-amplifier (CSA), an RC-CR pulse shaper and a winner-take-all (WTA) multiplexer that selects the channel with the largest input signal. Triggered by an external timing signal, a switch opens and a capacitor stores the peak voltage of the winner channel. The shaper rise and fall times are adjustable by means of external current inputs over a continuous range of 0.7 (mu)s to 9 (mu)s. Power consumption is 5.4 mW per channel, measured Equivalent Noise Charge (ENC) at 1 (mu)s peaking time. Zero leakage current is 33 rms electrons plus 7.3 rms electrons per pF of input capacitance. Design is fabricated in 0.5 (mu)m 3.3V CMOS technology.