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Sample records for 15o positron emission

  1. Comparison of cerebral blood flow measurement with [15O]-water positron emission tomography and arterial spin labeling magnetic resonance imaging: A systematic review.

    Fan, Audrey P; Jahanian, Hesamoddin; Holdsworth, Samantha J; Zaharchuk, Greg

    2016-05-01

    Noninvasive imaging of cerebral blood flow provides critical information to understand normal brain physiology as well as to identify and manage patients with neurological disorders. To date, the reference standard for cerebral blood flow measurements is considered to be positron emission tomography using injection of the [(15)O]-water radiotracer. Although [(15)O]-water has been used to study brain perfusion under normal and pathological conditions, it is not widely used in clinical settings due to the need for an on-site cyclotron, the invasive nature of arterial blood sampling, and experimental complexity. As an alternative, arterial spin labeling is a promising magnetic resonance imaging technique that magnetically labels arterial blood as it flows into the brain to map cerebral blood flow. As arterial spin labeling becomes more widely adopted in research and clinical settings, efforts have sought to standardize the method and validate its cerebral blood flow values against positron emission tomography-based cerebral blood flow measurements. The purpose of this work is to critically review studies that performed both [(15)O]-water positron emission tomography and arterial spin labeling to measure brain perfusion, with the aim of better understanding the accuracy and reproducibility of arterial spin labeling relative to the positron emission tomography reference standard.

  2. Comparison of global cerebral blood flow measured by phase-contrast mapping MRI with (15) O-H2 O positron emission tomography

    Vestergaard, Mark Bitsch; Lindberg, Ulrich; Aachmann-Andersen, Niels Jacob;

    2017-01-01

    PURPOSE: To compare mean global cerebral blood flow (CBF) measured by phase-contrast mapping magnetic resonance imaging (PCM MRI) and by (15) O-H2 O positron emission tomography (PET) in healthy subjects. PCM MRI is increasingly being used to measure mean global CBF, but has not been validated...... of the arterial input function. Flow was measured in the internal carotid and vertebral arteries by a noncardiac triggered PCM MRI sequence at 3T. The measured flow was normalized to total brain weight determined from a volume-segmented 3D T1 -weighted anatomical MR-scan. RESULTS: Mean CBF was 34.9 ± 3.4 mL/100 g...... in vivo against an accepted reference technique. MATERIALS AND METHODS: Same-day measurements of CBF by (15) O-H2 O PET and subsequently by PCM MRI were performed on 22 healthy young male volunteers. Global CBF by PET was determined by applying a one-tissue compartment model with measurement...

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

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

    2012-06-15

    Quantification of myocardial blood flow (MBF) with generator-produced {sup 82}Rb is an attractive alternative for centres without an on-site cyclotron. Our aim was to validate {sup 82}Rb-measured MBF in relation to that measured using {sup 15}O-water, as a tracer 100% of which can be extracted from the circulation even at high flow rates, in healthy control subject and patients with mild coronary artery disease (CAD). MBF was measured at rest and during adenosine-induced hyperaemia with {sup 82}Rb and {sup 15}O-water PET in 33 participants (22 control subjects, aged 30 {+-} 13 years; 11 CAD patients without transmural infarction, aged 60 {+-} 13 years). A one-tissue compartment {sup 82}Rb model with ventricular spillover correction was used. The {sup 82}Rb flow-dependent extraction rate was derived from {sup 15}O-water measurements in a subset of 11 control subjects. Myocardial flow reserve (MFR) was defined as the hyperaemic/rest MBF. Pearson's correlation r, Bland-Altman 95% limits of agreement (LoA), and Lin's concordance correlation {rho} {sub c} (measuring both precision and accuracy) were used. Over the entire MBF range (0.66-4.7 ml/min/g), concordance was excellent for MBF (r = 0.90, [{sup 82}Rb-{sup 15}O-water] mean difference {+-} SD = 0.04 {+-} 0.66 ml/min/g, LoA = -1.26 to 1.33 ml/min/g, {rho} {sub c} = 0.88) and MFR (range 1.79-5.81, r = 0.83, mean difference = 0.14 {+-} 0.58, LoA = -0.99 to 1.28, {rho} {sub c} = 0.82). Hyperaemic MBF was reduced in CAD patients compared with the subset of 11 control subjects (2.53 {+-} 0.74 vs. 3.62 {+-} 0.68 ml/min/g, p = 0.002, for {sup 15}O-water; 2.53 {+-} 1.01 vs. 3.82 {+-} 1.21 ml/min/g, p = 0.013, for {sup 82}Rb) and this was paralleled by a lower MFR (2.65 {+-} 0.62 vs. 3.79 {+-} 0.98, p = 0.004, for {sup 15}O-water; 2.85 {+-} 0.91 vs. 3.88 {+-} 0.91, p = 0.012, for {sup 82}Rb). Myocardial perfusion was homogeneous in 1,114 of 1,122 segments (99.3%) and there were no differences in MBF among the

  4. Positron emission tomography

    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. Changes of cognition and regional cerebral activity during acute hypoglycemia in normal subjects: A H2 15O positron emission tomographic study

    Bie Olsen, Lise Grimmeshave; Bie-Olsen, Lise G; Kjaer, Troels W;

    2009-01-01

    temporal gyrus. Visual impairment during hypoglycemia was associated with deactivation in the ventral visual stream. The anterior cingulate gyrus was activated during hypoglycemia in a load-dependent manner. Areas on the frontal convexity were differentially activated in response to the cognitive load...... during hypoglycemia. Our findings suggest that hypoglycemia induces changes in sensory processing in a cognition-independent manner, whereas activation of areas of higher order functions is influenced by cognitive load as well as hypoglycemia.......Blurred vision and cognitive difficulties are prominent symptoms during acute insulin-induced hypoglycemia. Our hypothesis was that changes in cerebral activity reflect these symptoms. Positron emission tomography (PET) with oxygen-15-labelled water was used to measure relative changes in regional...

  6. Assessment of the perfusion of glioblastomas before and during radiotherapy: longitudinal comparison between H{sub 2}-{sup 15}O positron emission tomography and perfusion MRI; Evaluation de la perfusion des glioblastomes en avant et pendant la radiotherapie: comparaison longitudinale entre la tomographie par emission de positons H2 15O et l'IRM de perfusion

    Laprie, A.; Ken, S.; Moyal Cohen-Jonathan, E. [Departement de radiotherapie, institut Claudius-Regaud, 31 - Toulouse (France); Laprie, A.; Ken, S.; Lotterie, J.A.; Franceries, X.; Celsis, P.; Payoux, P.; Berry, I. [Inserm imagerie cerebrale et handicaps neurologiques UMR 825, 31 - Toulouse (France); Lotterie, J.A.; Berry, I. [Departement de biophysique, centre hospitalier universitaire de Rangueil, 31 - Toulouse (France); Barcelo, C. [Departement de radiologie, centre hospitalier universitaire de Purpan, 31 - Toulouse (France)

    2010-10-15

    The authors report the comparison of different perfusion imagery modalities for patients suffering form glioblastomas and included in a phase-1 clinic trial comprising conformational radiotherapy concomitant with the use of a farnesyl-transferase inhibitor (tipifarnib). With these different techniques, perfusion MRI and perfusion positron emission tomography, the authors made respectively a qualitative and quantitative assessment of the tumour vascularisation. Short communication

  7. Positron emission tomography

    Muehllehner, Gerd; Karp, Joel S [Department of Radiology, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104 (United States)

    2006-07-07

    The developments in positron emission tomography (PET) are reviewed with an emphasis on instrumentation for clinical PET imaging. After a brief summary of positron imaging before the advent of computed tomography, various improvements are highlighted including the move from PET scanners with septa to fully 3D scanners, changes in the preferred scintillators, efforts to improve the energy discrimination, and improvements in attenuation correction. Time-of-flight PET imaging is given special attention due to the recent revival of this technique, which promises significant improvement. Besides technical instrumentation efforts, other factors which influenced the acceptance of clinical PET are also discussed. (review)

  8. Database of normal human cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen measured by positron emission tomography with {sup 15}O-labelled carbon dioxide or water, carbon monoxide and oxygen: a multicentre study in Japan

    Ito, Hiroshi [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, 980-8575, Aoba-Ku, Sendai (Japan); Kanno, Iwao [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Kato, Chietsugu [Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Sasaki, Toshiaki [Cyclotoron Research Center, Iwate Medical University, Morioka (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo (Japan); Ouchi, Yasuomi [Positron Medical Center, Hamamatsu Medical Center, Hamakita (Japan); Iida, Akihiko [Nagoya City Rehabilitation Center, Nagoya (Japan); Okazawa, Hidehiko [PET Unit, Research Institute, Shiga Medical Center, Moriyama (Japan); Hayashida, Kohei [Department of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Tsuyuguchi, Naohiro [Department of Neurosurgery, Osaka City University Medical School, Osaka (Japan); Ishii, Kazunari [Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Kuwabara, Yasuo [Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka (Japan); Senda, Michio [Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe (Japan)

    2004-05-01

    Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET) with oxygen-15 labelled carbon dioxide (C{sup 15}O{sub 2}) or {sup 15}O-labelled water (H{sub 2}{sup 15}O), {sup 15}O-labelled carbon monoxide (C{sup 15}O) and {sup 15}O-labelled oxygen ({sup 15}O{sub 2}) is useful for diagnosis and treatment planning in cases of cerebrovascular disease. The measured values theoretically depend on various factors, which may differ between PET centres. This study explored the applicability of a database of {sup 15}O-PET by examining between-centre and within-centre variation in values. Eleven PET centres participated in this multicentre study; seven used the steady-state inhalation method, one used build-up inhalation and three used bolus administration of C{sup 15}O{sub 2} (or H{sub 2}{sup 15}O) and {sup 15}O{sub 2}. All used C{sup 15}O for measurement of CBV. Subjects comprised 70 healthy volunteers (43 men and 27 women; mean age 51.8{+-}15.1 years). Overall mean{+-}SD values for cerebral cortical regions were: CBF=44.4{+-}6.5 ml 100 ml{sup -1} min{sup -1}; CBV=3.8{+-}0.7 ml 100 ml{sup -1}; OEF=0.44{+-}0.06; CMRO{sub 2}=3.3{+-}0.5 ml 100 ml{sup -1} min{sup -1}. Significant between-centre variation was observed in CBV, OEF and CMRO{sub 2} by one-way analysis of variance. However, the overall inter-individual variation in CBF, CBV, OEF and CMRO{sub 2} was acceptably small. Building a database of normal cerebral haemodynamics obtained by the{sup 15}O-PET methods may be practicable. (orig.)

  9. Positron Emission Tomography (PET)

    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.

  10. Positron Emission Tomography (PET)

    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.

  11. Positron emission mammography imaging

    Moses, William W.

    2003-10-02

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

  12. Positron Emission Mammography imaging

    Moses, William W.

    2004-06-01

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

  13. NMF on positron emission tomography

    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...

  14. A stereotaxic method of anatomical localization by means of H{sub 2}{sup 15}O positron emission tomography applicable to the brain activation study in cats. Registration of images of cerebral blood flow to brain atlas

    Sakiyama, Yojiro; Toyama, Hinako; Oda, Keiichi; Ishii, Shin-ichi; Ishiwata, Kiichi; Ishii, Kenji; Suzuki, Atsuko; Nakayama, Hitomi; Senda, Michio [Tokyo Metropolitan Inst. of Gerontology (Japan)

    1997-11-01

    In the neuronal activation study of normal animals, precise anatomical correlation, preferentially to a detailed brain atlas, is required for the activation foci co-registration. To obtain precise regional correlation between H{sub 2}{sup 15}O-PET images and the brain atlas, a method of stereotaxic image reorientation was applied to an activation study with vibrotactile stimulation. Cats anesthetized with halothane underwent repeated measurements of regional cerebral blood flow (rCBF) in the resting condition and during vibration of the right forepaw. The image set was adjusted three-dimensionally to the atlas. The postmortem brain was sectioned according to the atlas planes. The activated areas were determined by the stimulus-minus-resting subtraction images, and the areas were projected to the atlas. The PET images of the cat brain were compatible both to the postmortem brain slices and to the brain atlas. The activation foci obtained from the subtraction images corresponded to the area around the coronal sulcus, which is electrophysiologically known as the primary sensory area as described in the atlas. There were precise regional correlations between the PET image and anatomy in a PET activation study of the cat by means of stereotaxic image reorientation. (author)

  15. Positron Emission Mammotomography with Dual Planar Detectors

    Mark Smith; Raymond Raylman; Stanislaw Majewski

    2003-06-29

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

  16. Positron emission tomography basic sciences

    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...

  17. Radiopharmaceutical chemistry for positron emission tomography

    Elsinga, PH

    2002-01-01

    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 F-18-fluorination

  18. Advanced Instrumentation for Positron Emission Tomography [PET

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

    1985-04-01

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

  19. Is positron emission tomography useful in stroke?

    DeReuck, J; Leys, D; DeKeyser, J

    1997-01-01

    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

  20. 89Zr radiochemistry for positron emission tomography.

    Severin, Gregory W; Engle, Jonathan W; Barnhart, Todd E; Nickles, R Jerry

    2011-09-01

    The positron emitting isotope (89)Zr is an ideal radionuclide for use in positron emission tomography (PET) imaging with monoclonal antibodies (mAbs). This article reviews the cyclotron physics of (89)Zr production, and the chemical separation methods for isolating it from yttrium target material. (89)Zr coordination with the bifunctional chelate desferrioxamine B is discussed, along with the common procedures for attaching the chelate to mAbs. The review is intended to detail the procedure for creating (89)Zr labeled mAbs, going from cyclotron to PET.

  1. Positron emission tomography/magnetic resonance hybrid scanner imaging of cerebral blood flow using 15O-water positron emission tomography and arterial spin labeling magnetic resonance imaging in newborn piglets

    Andersen, Julie B; Henning, William S; Lindberg, Ulrich;

    2015-01-01

    Abnormality in cerebral blood flow (CBF) distribution can lead to hypoxic-ischemic cerebral damage in newborn infants. The aim of the study was to investigate minimally invasive approaches to measure CBF by comparing simultaneous (15)O-water positron emission tomography (PET) and single TI pulsed...

  2. Positron Emission Tomography: Its 65 years

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

    2016-04-01

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

  3. Emission and transmission noise propagation in positron emission computed tomography

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

    1979-06-01

    Errors in positron emission computed tomograms are the result of noise propagated from three sources: (1) the statistical fluctuation in the positron coincidence events; (2) the statistical fluctuation in the incident transmission beam; and (3) the statistical fluctuation in the transmitted beam. The data for the transmission study in (2) and (3) are used to compensate for internal absorption of the distributed positron source. For the reconstruction of a circular phantom using the convolution algorithm, the percent root-mean-square uncertainty (%RMS) is related to the total measured positron events C and the incident photon flux per cm I/sub 0/. Our derivation of the %RMS uncertainty based on the propagation of errors yields a simple expression: %RMS = ..sqrt..K/sub 1//C + K/sub 2//I/sub 0/. The constants K/sub 1/ = 4.52 x 10/sup 8/ and K/sub 2/ = 1.48 x 10/sup 8/ were determined for a 20 cm diameter disc based on computer simulation. The projection data were analytically calculated with an attenuation coefficient ..mu.. = 0.0958 cm/sup -1/ for 140 angles between 0 and ..pi... Poisson noise was added to the positron coincidence events, the incident transmission events I/sub 0/, and the transmitted events. These results indicate that for a total number of incident transmission photons per cm of 2.0 x 10/sup 5/, the contrast resolution for a fixed spatial resolution is limited to 27% even with an infinite number of emission events. For a total of 10/sup 6/ emission events the contrast resolution is 34%.

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

    Mohsen Mashayekhi

    2015-05-01

    Full Text Available Introduction Range and diffusion of positron-emitting radiopharmaceuticals are important parameters for image resolution in positron emission tomography (PET. In this study, GEANT4 toolkit was applied to study positron diffusion in soft tissues with and without a magnetic field for six commonly used isotopes in PET imaging including 11C, 13N, 15O, 18F, 68Ga, and 82Rb. Materials and Methods GEANT4 toolkit was used to simulate the transport and interactions of positrons. Calculations were performed for the soft tissue phantom (8 mm ×8 mm × 8 mm. Positrons were emitted isotropically from the center of the phantom. By the application of a magnetic field perpendicular to the path of positrons, lateral scattering of positrons could be prevented due to Lorentz force. When the positron energy was below the cut-off threshold (0.001 MeV, the simulation was terminated. Results The findings showed that the presence of a magnetic field increased the rate of positron annihilation. At magnetic field strengths of 3, 7, and 10 Tesla, 18F with the lowest decay energy showed improvements in the ratio of full width at half maximum (FWHM resolution to the peak of curve by 3.64%, 3.89%, and 5.96%, respectively. In addition, at magnetic field strengths of 3, 7 and 10 Tesla, 82Rb with the highest decay energy showed improvements in resolution by 33%, 85%, and 99%, respectively. Conclusion Application of a magnetic field perpendicular to the positron diffusion plane prevented the scattering of positrons, and consequently, improved the intrinsic spatial resolution of PET imaging, caused by positron range effects.

  5. Positron Emission Tomography of the Heart

    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.

  6. Motion correction in thoracic positron emission tomography

    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...

  7. Positron emission tomography of the heart

    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.

  8. Positron emission tomography and radiation oncology

    Fullerton, PhD, Gary D.; Fox, MD, Peter; Phillips, MD, William T.

    2001-10-01

    Medical physics research is providing new avenues for addressing the fundamental problem of radiation therapy-how to provide a tumor-killing dose while reducing the dose to a non-lethal level for critical organs in adjacent portions of the patient anatomy. This talk reviews the revolutionary impact of Positron Emission Tomography on the practice of radiation oncology. The concepts of PET imaging and the development of "tumor" imaging methods using 18F-DG flouro-deoxyglucose are presented to provide the foundation for contemporary research and application to therapy. PET imaging influences radiation therapy decisions in multiple ways. Imaging of occult but viable tumor metastases eliminates misguided therapy attempts. The ability to distinguish viable tumor from scar tissue and necroses allows reduction of treatment portals and more selective treatments. Much research remains before the clinical benefits of these advances are fully realized.

  9. Fundamental limits of positron emission mammography

    Moses, William W.; Qi, Jinyi

    2001-06-01

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

  10. Instrumentation optimization for positron emission mammography

    Moses, William W.; Qi, Jinyi

    2003-06-05

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

  11. Recent Developments in Positron Emission Tomography (PET) Instrumentation

    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.

  12. Positron emission tomography in drug development and drug evaluation

    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 usin

  13. Amyloid positron emission tomography and cognitive reserve

    Matteo Bauckneht; Agnese Picco; Flavio Nobili; Silvia Morbelli

    2015-01-01

    Alzheimer’s disease(AD) is characterized by a nonlinear progressive course and several aspects influence the relationship between cerebral amount of AD pathology and the clinical expression of the disease. Brain cognitive reserve(CR) refers to the hypothesized capacity of an adult brain to cope with brain damage in order to minimize symptomatology. CR phenomenon contributed to explain the disjunction between the degree of neurodegeneration and the clinical phenotype of AD. The possibility to track brain amyloidosis(Aβ) in vivo has huge relevance for AD diagnosis and new therapeutic approaches. The clinical repercussions of positron emission tomography(PET)-assessed Aβ load are certainly mediated by CR thus potentially hampering the prognostic meaning of amyloid PET in selected groups of patients. Similarly, amyloid PET and cerebrospinal fluid amyloidosis biomarkers have recently provided new evidence for CR. The present review discusses the concept of CR in the framework of available neuroimaging studies and specifically deals with the reciprocal influences between amyloid PET and CR in AD patients and with the potential consequent interventional strategies for AD.

  14. Microfluidics for Positron Emission Tomography Probe Development

    Ming-Wei Wang

    2010-07-01

    Full Text Available Owing to increased needs for positron emission tomography (PET, high demands for a wide variety of radiolabeled compounds will have to be met by exploiting novel radiochemistry and engineering technologies to improve the production and development of PET probes. The application of microfluidic reactors to perform radiosyntheses is currently attracting a great deal of interest because of their potential to deliver many advantages over conventional labeling systems. Microfluidics-based radiochemistry can lead to the use of smaller quantities of precursors, accelerated reaction rates, and easier purification processes with greater yield and higher specific activity of desired probes. Several proof-of-principle examples along with the basics of device architecture and operation and the potential limitations of each design are discussed. Along with the concept of radioisotope distribution from centralized cyclotron facilities to individual imaging centers and laboratories (“decentralized model”, an easy-to-use, stand-alone, flexible, fully automated, radiochemical microfluidic platform can provide simpler and more cost-effective procedures for molecular imaging using PET.

  15. Data acquisition with a positron emission tomograph

    Freifelder, R.; Karp, J.S. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1997-12-31

    Positron Emission Tomography (PET) is a clinical imaging modality used in Nuclear Medicine. PET measures functionality rather than anatomical features and is therefore invaluable in the treatment of diseases which are characterized by functional changes in organs rather than anatomical changes. Typical diseases for which PET is used are cancer, epilepsy, and heart disease. While the scanners are not very complex, the performance demands on the devices are high. Excellent spatial resolution, 4-5 mm, and high sensitivity are key to maintaining high image quality. Compensation or suppression of scattered radiation is also necessary for good image quality. The ability to acquire data under high counting rates is also necessary in order to minimize the injected dose to the patient, minimize the patient`s time in the scanner, and finally to minimize blurring due to patient motion. We have adapted various techniques in our data acquisition system which will be reported on in this talk. These include pulse clipping using lumped delay lines, flash ADCs with short sampling time, the use of a local positioning algorithm to limit the number of data words being used in subsequent second level software triggers and calculations, and finally the use of high speed dedicated calculator boards for on-line rebinning and reduction of the data. Modifications to the system to allow for transmission scanning will also be discussed.

  16. Positron Emission Mammography with Multiple Angle Acquisition

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

    2002-11-01

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

  17. Positron Emission Mammography with Multiple Angle Acquisition

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

    2002-11-01

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

  18. High power laser production of short-lived isotopes for positron emission tomography

    Ledingham, K W D [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); McKenna, P [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); McCanny, T [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Shimizu, S [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Yang, J M [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Robson, L [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Zweit, J [CR-UK/UMIST Radiochemical Targeting and Imaging, Paterson Institute for Cancer Research, Christie Hospital, Manchester M20 4BX (United Kingdom); Gillies, J M [CR-UK/UMIST Radiochemical Targeting and Imaging, Paterson Institute for Cancer Research, Christie Hospital, Manchester M20 4BX (United Kingdom); Bailey, J [CR-UK/UMIST Radiochemical Targeting and Imaging, Paterson Institute for Cancer Research, Christie Hospital, Manchester M20 4BX (United Kingdom); Chimon, G N [CR-UK/UMIST Radiochemical Targeting and Imaging, Paterson Institute for Cancer Research, Christie Hospital, Manchester M20 4BX (United Kingdom); Clarke, R J [Central Laser Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX110QX (United Kingdom); Neely, D [Central Laser Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX110QX (United Kingdom); Norreys, P A [Central Laser Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX110QX (United Kingdom); Collier, J L [Central Laser Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX110QX (United Kingdom); Singhal, R P [Department of Physics and Astronomy, University of Glasgow G12 8QQ (United Kingdom); Wei, M S [Blackett Laboratory, Imperial College of Science, Technology and Medicine, London SW7 2BZ (United Kingdom)] [and others

    2004-08-21

    Positron emission tomography (PET) is a powerful diagnostic/imaging technique requiring the production of the short-lived positron emitting isotopes {sup 11}C, {sup 13}N, {sup 15}O and {sup 18}F by proton irradiation of natural/enriched targets using cyclotrons. The development of PET has been hampered due to the size and shielding requirements of nuclear installations. Recent results show that when an intense laser beam interacts with solid targets, megaelectronvolt (MeV) protons capable of producing PET isotopes are generated. This report describes how to generate intense PET sources of {sup 11}C and {sup 18}F using a petawatt laser beam. The work describing the laser production of {sup 18}F through a (p,n) {sup 18}O reaction, and the subsequent synthesis of 2-[{sup 18}F] is reported for the first time. The potential for developing compact laser technology for this purpose is discussed.

  19. Positron emission tomography : measurement of transgene expression

    de Vries, EFJ; Vaalburg, W

    2002-01-01

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

  20. 64Cu loaded liposomes as positron emission tomography imaging agents

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

    2011-01-01

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

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

    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

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

    Paans, AMJ

    1997-01-01

    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 no

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

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

    2002-01-01

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

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

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

    1997-10-01

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

  5. Positron emission particle tracking-Application and labelling techniques

    David J.Parker; Xianfeng Fan

    2008-01-01

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

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

    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...... subjects using three different MRI techniques: arterial spin labeling (ASL), dynamic contrast enhanced T1 weighted perfusion MRI (DCE) and phase contrast mapping (PCM). All MRI measurements were performed within the same session. In 10 of the subjects repeated CBF measurements by (15) O labeled water PET......L/100 g/min, 16.2% and 4.8%, for DCE 43.0 mL/100 g/min, 20.0%, 15.1% and for PET 41.9 mL/100 g/min, 16.5% and 11.9%, respectively. Only for DCE and PCM a significant positive correlation between measurements was demonstrated. CONCLUSION: These findings confirm large between subject variability in CBF...

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

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

    2012-07-15

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

  8. A novel clustering approach to positron emission particle tracking

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

    2016-03-01

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

  9. ENVISION, developing Positron Emission Tomography for particle therapy

    2013-01-01

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

  10. Current and future technological trends in positron emission tomography.

    Karp, J S; Freifelder, R

    1992-04-01

    Current trends in positron emission tomography (PET) instrumentation are examined, with an emphasis on providing information suitable to the prospective PET user. Basic principles underlying PET are explained and information on performance measurements, techniques, and quantitation are given in order to allow the user to compare and contrast different types of PET scanners. These scanner designs are described. Specific examples are given and the combination of PET with other modalities is discussed.

  11. Positron Emission Particle Tracking (PEPT) for Fluid Flow Measurements

    Langford, Seth, E-mail: utne@utk.edu [Department of Nuclear Engineering, University of Tennessee-Knoxville, 315 Pasqua Nuclear Engineering, Knoxville, TN 37996 (United States); Wiggins, Cody, E-mail: cwiggin2@vols.utk.edu [University of Tennessee-Knoxville, Department of Physics and Astronomy, 401 Nielsen Physics Building, Knoxville, TN 37996 (United States); Tenpenny, Daniel; Ruggles, Arthur [Department of Nuclear Engineering, University of Tennessee-Knoxville, 315 Pasqua Nuclear Engineering, Knoxville, TN 37996 (United States)

    2016-06-15

    Highlights: • A new method for tracking multiple particles using positron emission particle tracking (PEPT) is introduced. • PEPT measurement of flow in a rectangular channel is tested against PIV and PTV. • Further work is identified to improve performance of PEPT for flow measurement. - Abstract: Positron emission particle tracking (PEPT) is used to study the behavior of flow in a rectangular test section. A multiple-particle tracking technique (multi-PEPT) is proposed and tested using a once-through flow system and a preclinical positron emission tomography (PET) scanner. This measurement is then compared to particle image velocimetry (PIV) and high-speed particle tracking velocimetry (PTV) studies of the same test section. Uncertainties in the established flow measurement methods used to validate the PEPT performance are quantified. Mean flow velocity are compared as measured by the three methods. Minor variations are exposed in the data comparisons, and uncertainty exists due to the statistical nature of our PEPT method. Nonetheless, multi-PEPT is shown to be capable as a means of examining characteristics of a complex flow regime.

  12. Investigation of granular impact using positron emission particle tracking

    Marston, Jeremy O.

    2015-04-01

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

  13. [Methods and clinical applications of positron emission tomography in endocrinology].

    De Landsheere, C; Lamotte, D

    1990-01-01

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

  14. Oncological applications of positron emission tomography with fluorine-18 fluorodeoxyglucose

    Rigo, P. [Division of Nuclear Medicine, University Hospital, Sart Tilman, Liege (Belgium); Paulus, P. [Division of Nuclear Medicine, University Hospital, Sart Tilman, Liege (Belgium); Kaschten, B.J. [Cyclotron Research Centre, University of Liege and Division of Neurosurgery, University Hospital, Sart Tilman, Liege (Belgium); Hustinx, R. [Division of Nuclear Medicine, University Hospital, Sart Tilman, Liege (Belgium); Bury, T. [Division of Pneumology, University Hospital, Sart Tilman, Liege (Belgium); Jerusalem, G. [Division of Onco-Hematology, University Hospital, Sart Tilman, Liege (Belgium); Benoit, T. [Division of Nuclear Medicine, University Hospital, Sart Tilman, Liege (Belgium); Foidart-Willems, J. [Division of Nuclear Medicine, University Hospital, Sart Tilman, Liege (Belgium)

    1996-12-01

    Positron emission tomography (PET) is now primarily used in oncological indication owing to the successful application of fluorine-18 fluorodeoxyglucose (FDG) in an increasing number of clinical indications at different stages of diagnosis, and for staging and follow-up. This review first considers the biological characteristics of FDG and then discusses methodological considerations regarding its use. Clinical indications are considered, and the results achieved in respect of various organs and tumour types are reviewed in depth. The review concludes with a brief consideration of the ways in which clinical PET might be improved. (orig.). With 6 figs., 8 tabs.

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

    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......-L-(beta-11C tryptophan) (5HTP) quantifies the activity of amino acid decarboxylase in the conversion to 5HT. On the other hand, alpha-methyl-tryptophan (AMT) measures the conversion to the corresponding 5-hydroxytryptophan analogue. The irreversible binding of the PET probe 5HTP in the monkey brain was lower...

  16. RPC: from High Energy Physics to Positron Emission Tomography

    Belli, G; Vecchi, C De; Giroletti, E; Musitelli, G; Nardo, R; Necchi, M M; Pagano, D; Ratti, S P; Riccardi, C; Sani, G; Torre, P; Vitulo, P; Viviani, C [Dipartimento di Fisica Nucleare e Teorica - Universita di Pavia and Istituto Nazionale di Fisica Nucleare - Sezione di Pavia - via A. Bassi, 6 Pavia - (Italy)

    2006-05-15

    A low cost gas-based charged particle detector, the Resistive Plate Counter (RPC) intensively used in fixed target and collider high energy experiments, is proposed as basic detector for Positron Emission Tomography. The performance of RPCs in terms of intrinsic space and time resolution and electronic pulse height response, makes it possible to transform standard RPCs into photon detectors and therefore to compensate for the photon sensitivity of scintillating crystals, when the efficiency of the complex crystal + photomultiplier is turned into standard quantum efficiency (q.e). Prototype multigap glass RPCs were developed which optimize {gamma} detection efficiency and thus might substitute the traditional scintillators setups.

  17. [Positron emission tomography: diagnostic imaging on a molecular level].

    Allemann, K; Wyss, M; Wergin, M; Bley, C Rohrer; Ametamay, S; Bruehlmeier, M; Kaser-Hotz, B

    2004-08-01

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

  18. Kinetic modeling in pre-clinical positron emission tomography

    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.

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

    Gillard, W

    2008-01-15

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

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

    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].

  1. The next generation of positron emission tomography radiopharmaceuticals in oncology.

    Rice, Samuel L; Roney, Celeste A; Daumar, Pierre; Lewis, Jason S

    2011-07-01

    Although (18)F-fluorodeoxyglucose ((18)F-FDG) is still the most widely used positron emission tomography (PET) radiotracer, there are a few well-known limitations to its use. The last decade has seen the development of new PET probes for in vivo visualization of specific molecular targets, along with important technical advances in the production of positron-emitting radionuclides and their related labeling methods. As such, a broad range of new PET tracers are in preclinical development or have recently entered clinical trials. The topics covered in this review include labeling methods, biological targets, and the most recent preclinical or clinical data of some of the next generation of PET radiopharmaceuticals. This review, which is by no means exhaustive, has been separated into sections related to the PET radionuclide used for radiolabeling: fluorine-18, for the labeling of agents such as FACBC, FDHT, choline, and Galacto-RGD; carbon-11, for the labeling of choline; gallium-68, for the labeling of peptides such as DOTATOC and bombesin analogs; and the long-lived radionuclides iodine-124 and zirconium-89 for the labeling of monoclonal antibodies cG250, and J591 and trastuzumab, respectively.

  2. Positron Emission Tomography Application to Drug Development and Research

    Salvadori, Piero A.

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

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

    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. A Case of Corticobasal Degeneration Studied with Positron Emission Tomography

    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.

  5. Positron emission tomography in CNS drug discovery and drug monitoring.

    Piel, Markus; Vernaleken, Ingo; Rösch, Frank

    2014-11-26

    Molecular imaging methods such as positron emission tomography (PET) are increasingly involved in the development of new drugs. Using radioactive tracers as imaging probes, PET allows the determination of the pharmacokinetic and pharmacodynamic properties of a drug candidate, via recording target engagement, the pattern of distribution, and metabolism. Because of the noninvasive nature and quantitative end point obtainable by molecular imaging, it seems inherently suited for the examination of a pharmaceutical's behavior in the brain. Molecular imaging, most especially PET, can therefore be a valuable tool in CNS drug research. In this Perspective, we present the basic principles of PET, the importance of appropriate tracer selection, the impact of improved radiopharmaceutical chemistry in radiotracer development, and the different roles that PET can fulfill in CNS drug research.

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

    Pizzichemi, M.

    2016-08-01

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

  7. Data acquisition electronics for positron emission mammography (PEM) detectors

    Martinez, J.D. [Digital Systems Design Group, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)]. E-mail: jormarp1@doctor.upv.es; Sebastia, A. [Digital Systems Design Group, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Cerda, J. [Digital Systems Design Group, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Esteve, R. [Digital Systems Design Group, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Mora, F.J. [Digital Systems Design Group, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Toledo, J.F. [Digital Systems Design Group, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Benlloch, J.M. [Nuclear Medical Physics Group, Instituto de Fisica Corpuscular (CSIC-UV), Poligono de la Coma s/n, 46980 Paterna, Valencia (Spain); Gimenez, N. [Nuclear Medical Physics Group, Instituto de Fisica Corpuscular (CSIC-UV), Poligono de la Coma s/n, 46980 Paterna, Valencia (Spain); Gimenez, M. [Nuclear Medical Physics Group, Instituto de Fisica Corpuscular (CSIC-UV), Poligono de la Coma s/n, 46980 Paterna, Valencia (Spain); Lerche, Ch. W. [Nuclear Medical Physics Group, Instituto de Fisica Corpuscular (CSIC-UV), Poligono de la Coma s/n, 46980 Paterna, Valencia (Spain); Pavon, N. [Nuclear Medical Physics Group, Instituto de Fisica Corpuscular (CSIC-UV), Poligono de la Coma s/n, 46980 Paterna, Valencia (Spain); Sanchez, F. [Nuclear Medical Physics Group, Instituto de Fisica Corpuscular (CSIC-UV), Poligono de la Coma s/n, 46980 Paterna, Valencia (Spain)

    2005-01-21

    Positron emission mammography (PEM) is an innovative technique to increase sensitivity and overcome the main drawbacks of conventional X-ray screening. However, dedicated PET imaging systems demand specific hardware solutions for data acquisition and processing that can take advantage of the reduction in the number of channels. Data acquisition issues can affect PEM scanners performance and they should be exhaustively addressed in order to exploit the increment in the event count rate. This is crucial in order to reduce both the scanning time and the total injected dose. This paper presents the electronics for our PEM camera prototype that enables us to achieve very high-count rates and perform comprehensive online processing. Results about acquisition in our detector for a typical clinical setup are studied using Monte Carlo simulation of hot lesion phantoms.

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

    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.

  9. Lesion detection and quantitation of positron emission mammography

    Qi, Jinyi; Huesman, Ronald H.

    2001-12-01

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

  10. Positron emission tomography of incidentally detected small pulmonary nodules

    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...... (approx. 3.3% of the entire study population). The prevalence of malignancy in this group was 50%. The accuracy of PET was high, in spite of the fact that seven patients had nodules smaller than 15 mm and two patients had bronchoalveolar cell carcinoma. This small prospective study indicates...... that subsequent assessment with FDG PET of small pulmonary nodules incidentally detected by CT has the potential to minimize the numbers of invasive procedures performed in individuals with a benign pulmonary lesion. FDG PET also increases the possibility of an early diagnosis as compared to the strategy...

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

    Savi, A. [INB CNR, Inst. H.S. Raffaele, Univ. of Milan (Italy); Gilardi, M.C. [INB CNR, Inst. H.S. Raffaele, Univ. of Milan (Italy); Rizzo, G. [INB CNR, Inst. H.S. Raffaele, Univ. of Milan (Italy); Pepi, M. [Centro Cardiologico, Fondazione I. Monzino, Milan (Italy); Landoni, C. [INB CNR, Inst. H.S. Raffaele, Univ. of Milan (Italy); Rossetti, C. [INB CNR, Inst. H.S. Raffaele, Univ. of Milan (Italy); Lucignani, G. [INB CNR, Inst. H.S. Raffaele, Univ. of Milan (Italy); Bartorelli, A. [Centro Cardiologico, Fondazione I. Monzino, Milan (Italy); Fazio, F. [INB CNR, Inst. H.S. Raffaele, Univ. of Milan (Italy)

    1995-03-01

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

  12. Absolute cerebral blood flow and blood volume measured by magnetic resonance imaging bolus tracking: comparison with positron emission tomography values

    Østergaard, Leif; Smith, D F; Vestergaard-Poulsen, Peter;

    1998-01-01

    The authors determined cerebral blood flow (CBF) with magnetic resonance imaging (MRI) of contrast agent bolus passage and compared the results with those obtained by O-15 labeled water (H215O) and positron emission tomography (PET). Six pigs were examined by MRI and PET under normo......- and hypercapnic conditions. After dose normalization and introduction of an empirical constant phi Gd, absolute regional CBF was calculated from MRI. The spatial resolution and the signal-to-noise ratio of CBF measurements by MRI were better than by the H215O-PET protocol. Magnetic resonance imaging cerebral...... blood volume (CBV) estimates obtained using this normalization constant correlated well with values obtained by O-15 labeled carbonmonooxide (C15O) PET. However, PET CBV values were approximately 2.5 times larger than absolute MRI CBV values, supporting the hypothesized sensitivity of MRI to small...

  13. Positron Emission Tomography with Three-Dimensional Reconstruction

    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.

  14. Positron Emission Tomography Detector Development for Plant Biology

    Weisenberger, A G; McKisson, J; Stolin, A; Zorn, C; Howell, C R; Crowell, A S; Reid, C D; Majewski, S

    2010-01-01

    There are opportunities for the development of new tools to advance plant biology research through the use of radionuclides. Thomas Jefferson National Accelerator Facility, Duke University, West Virginia University and the University of Maryland are collaborating on the development of radionuclide imaging technologies to facilitate plant biology research. Biological research into optimizing plant productivity under various environmental constraints, biofuel and carbon sequestration research are areas that could potentially benefit from new imaging technologies. Using 11CO2 tracers, the investigators at Triangle University Nuclear Laboratory / Duke University Phytotron are currently researching the dynamical responses of plants to environmental changes forecasted from increasing greenhouse trace gases involved in global change. The biological research primary focus is to investigate the impact of elevated atmospheric CO2 and nutrients limitation on carbon and nitrogen dynamics in plants. We report here on preliminary results of 11CO2 plant imaging experiments involving barley plants using Jefferson Lab dual planar positron emission tomography detectors to image 11CO2 in live barley plants. New detector designs will be developed based on the preliminary studies reported here and further planned.

  15. Usefulness of Positron Emission Tomographic Studies for Gliomas

    MIYAKE, Keisuke; OGAWA, Daisuke; OKADA, Masaki; HATAKEYAMA, Tetsuhiro; TAMIYA, Takashi

    2016-01-01

    Non-invasive positron emission tomography (PET) enables the measurement of metabolic and molecular processes with high sensitivity. PET plays a significant role in the diagnosis, prognosis, and treatment of brain tumors and predominantly detects brain tumors by detecting their metabolic alterations, including energy metabolism, amino acids, nucleic acids, and hypoxia. Glucose metabolic tracers are related to tumor cell energy and exhibit good sensitivity but poor specificity for malignant tumors. Amino acid metabolic tracers provide a better delineation of tumors and cellular proliferation. Nucleic acid metabolic tracers have a high sensitivity for malignant tumors and cellular proliferation. Hypoxic metabolism tracers are useful for detecting resistance to radiotherapy and chemotherapy. Therefore, PET imaging techniques are useful for detecting biopsy-targeting points, deciding on tumor resection, radiotherapy planning, monitoring therapy, and distinguishing brain tumor recurrence or progression from post-radiotherapy effects. However, it is not possible to use only one PET tracer to make all clinical decisions because each tracer has both advantages and disadvantages. This study focuses on the different kinds of PET tracers and summarizes their recent applications in patients with gliomas. Combinational uses of PET tracers are expected to contribute to differential diagnosis, prognosis, treatment targeting, and monitoring therapy. PMID:27250577

  16. Epithelioid sarcoma with muscle metastasis detected by positron emission tomography

    Oya Masafumi

    2008-08-01

    Full Text Available Abstract Background Epithelioid sarcoma is an uncommon high-grade sarcoma, mostly involving the extremities. Case presentation A 33-year-old man was referred to our institute with a diagnosis of Volkmann's contracture with the symptom of flexion contracture of the fingers associated with swelling in his left forearm. Magnetic resonance imaging (MRI showed abnormal signal intensity, comprising iso-signal intensity on T1- and high-signal intensity on T2-weighted images surrounding the flexor tendons in the forearm. Diagnosis of epithelioid sarcoma was made by open biopsy, and amputation at the upper arm was then undertaken. [18F]-2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET detected multiple lesions with an increased uptake in the right neck, the bilateral upper arms and the right thigh, as well as in the left axillary lymph nodes, with maximum standardized uptake value (SUVmax ranging from 2.0 to 5.5 g/ml. Magnetic resonance imaging confirmed that there was a lesion within the right thigh muscle which was suggestive of metastasis, even though the lesion was occult clinically. Conclusion Increased uptake on FDG-PET might be representative of epithelioid sarcoma, and for this reason FDG-PET may be useful for detecting metastasis. Muscle metastasis is not well documented in epithelioid sarcoma. Accordingly, the frequency of muscle metastasis, including occult metastasis, needs to be further analyzed.

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

    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...

  18. European health telematics networks for positron emission tomography

    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.

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

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

    2003-02-01

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

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

    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.

  1. Markerless motion tracking of awake animals in positron emission tomography.

    Kyme, Andre; Se, Stephen; Meikle, Steven; Angelis, Georgios; Ryder, Will; Popovic, Kata; Yatigammana, Dylan; Fulton, Roger

    2014-11-01

    Noninvasive functional imaging of awake, unrestrained small animals using motion-compensation removes the need for anesthetics and enables an animal's behavioral response to stimuli or administered drugs to be studied concurrently with imaging. While the feasibility of motion-compensated radiotracer imaging of awake rodents using marker-based optical motion tracking has been shown, markerless motion tracking would avoid the risk of marker detachment, streamline the experimental workflow, and potentially provide more accurate pose estimates over a greater range of motion. We have developed a stereoscopic tracking system which relies on native features on the head to estimate motion. Features are detected and matched across multiple camera views to accumulate a database of head landmarks and pose is estimated based on 3D-2D registration of the landmarks to features in each image. Pose estimates of a taxidermal rat head phantom undergoing realistic rat head motion via robot control had a root mean square error of 0.15 and 1.8 mm using markerless and marker-based motion tracking, respectively. Markerless motion tracking also led to an appreciable reduction in motion artifacts in motion-compensated positron emission tomography imaging of a live, unanesthetized rat. The results suggest that further improvements in live subjects are likely if nonrigid features are discriminated robustly and excluded from the pose estimation process.

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

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

    2009-10-24

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

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

    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 ...

  4. 77 FR 71802 - Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    2012-12-04

    ... HUMAN SERVICES Food and Drug Administration Guidance on Investigational New Drug Applications for... ``Investigational New Drug Applications for Positron Emission Tomography (PET) Drugs.'' The guidance is intended to assist manufacturers of PET drugs in submitting investigational new drug applications (INDs)....

  5. 76 FR 47593 - Guidance for Small Business Entities on Current Good Manufacturing Practice for Positron Emission...

    2011-08-05

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

  6. Physiologic positron emission tomography/CT imaging of an integrated orbital implant.

    Graue, Gerardo F; Finger, Paul T

    2012-01-01

    A 46-year-old woman with a T4N0M0 choroidal melanoma was staged for metastatic disease with whole-body positron emission tomography/CT imaging. She underwent enucleation of the right eye and placement of a 20-mm MEDPOR spherical implant. Four months after surgery, follow-up positron emission tomography/CT imaging revealed physiologic metabolic activity in the MEDPOR implant with no evidence of orbital melanoma or chronic inflammation.

  7. Mapping {sup 15}O Production Rate for Proton Therapy Verification

    Grogg, Kira; Alpert, Nathaniel M.; Zhu, Xuping [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Min, Chul Hee [Department of Radiological Science, College of Health Science, Yonsei University, Wonju, Kangwon (Korea, Republic of); Testa, Mauro; Winey, Brian [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Normandin, Marc D. [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Shih, Helen A.; Paganetti, Harald; Bortfeld, Thomas [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); El Fakhri, Georges, E-mail: elfakhri@pet.mgh.harvard.edu [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2015-06-01

    Purpose: This work was a proof-of-principle study for the evaluation of oxygen-15 ({sup 15}O) production as an imaging target through the use of positron emission tomography (PET), to improve verification of proton treatment plans and to study the effects of perfusion. Methods and Materials: Dynamic PET measurements of irradiation-produced isotopes were made for a phantom and rabbit thigh muscles. The rabbit muscle was irradiated and imaged under both live and dead conditions. A differential equation was fitted to phantom and in vivo data, yielding estimates of {sup 15}O production and clearance rates, which were compared to live versus dead rates for the rabbit and to Monte Carlo predictions. Results: PET clearance rates agreed with decay constants of the dominant radionuclide species in 3 different phantom materials. In 2 oxygen-rich materials, the ratio of {sup 15}O production rates agreed with the expected ratio. In the dead rabbit thighs, the dynamic PET concentration histories were accurately described using {sup 15}O decay constant, whereas the live thigh activity decayed faster. Most importantly, the {sup 15}O production rates agreed within 2% (P>.5) between conditions. Conclusions: We developed a new method for quantitative measurement of {sup 15}O production and clearance rates in the period immediately following proton therapy. Measurements in the phantom and rabbits were well described in terms of {sup 15}O production and clearance rates, plus a correction for other isotopes. These proof-of-principle results support the feasibility of detailed verification of proton therapy treatment delivery. In addition, {sup 15}O clearance rates may be useful in monitoring permeability changes due to therapy.

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

    Zizhong Li

    Full Text Available BACKGROUND AND PURPOSE: 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. EXPERIMENTAL APPROACH: 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. KEY RESULTS: 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. CONCLUSION AND IMPLICATIONS: 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.

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

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

    1995-07-01

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

  10. Noninvasive imaging of islet grafts using positron-emission tomography

    Lu, Yuxin; Dang, Hoa; Middleton, Blake; Zhang, Zesong; Washburn, Lorraine; Stout, David B.; Campbell-Thompson, Martha; Atkinson, Mark A.; Phelps, Michael; Gambhir, Sanjiv Sam; Tian, Jide; Kaufman, Daniel L.

    2006-07-01

    Islet transplantation offers a potential therapy to restore glucose homeostasis in type 1 diabetes patients. However, islet transplantation is not routinely successful because most islet recipients gradually lose graft function. Furthermore, serological markers of islet function are insensitive to islet loss until the latter stages of islet graft rejection. A noninvasive method of monitoring islet grafts would aid in the assessment of islet graft survival and the evaluation of interventions designed to prolong graft survival. Here, we show that recombinant adenovirus can engineer isolated islets to express a positron-emission tomography (PET) reporter gene and that these islets can be repeatedly imaged by using microPET after transplantation into mice. The magnitude of signal from engineered islets implanted into the axillary cavity was directly related to the implanted islet mass. PET signals attenuated over the following weeks because of the transient nature of adenovirus-mediated gene expression. Because the liver is the preferred site for islet implantation in humans, we also tested whether islets could be imaged after transfusion into the mouse liver. Control studies revealed that both intrahepatic islet transplantation and hyperglycemia altered the biodistribution kinetics of the PET probe systemically. Although transplanted islets were dispersed throughout the liver, clear signals from the liver region of mice receiving PET reporter-expressing islets were detectable for several weeks. Viral transduction, PET reporter expression, and repeated microPET imaging had no apparent deleterious effects on islet function after implantation. These studies lay a foundation for noninvasive quantitative assessments of islet graft survival using PET. diabetes | transplantation

  11. The accuracy of positron emission tomography in the detection of posttransplant lymphoproliferative disorder.

    Dierickx, Daan; Tousseyn, Thomas; Requilé, Annelies; Verscuren, Raf; Sagaert, Xavier; Morscio, Julie; Wlodarska, Iwona; Herreman, An; Kuypers, Dirk; Van Cleemput, Johan; Nevens, Frederik; Dupont, Lieven; Uyttebroeck, Anne; Pirenne, Jacques; De Wolf-Peeters, Christiane; Verhoef, Gregor; Brepoels, Lieselot; Gheysens, Olivier

    2013-05-01

    We investigated sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-fluorodeoxyglucose-positron emission tomography in 170 cases with suspected or biopsy-proven posttransplant lymphoproliferative disorder. All solid organ and hematopoietic stem cell transplant recipients who underwent an 18F-fluorodeoxyglucose-positron emission tomography scan between 2003 and 2010 in our center for the indication posttransplant lymphoproliferative disorder, were retrospectively reviewed and results were compared with tissue biopsy whenever possible. One hundred and seventy positron emission tomography scans in 150 patients were eligible for evaluation. In 45 cases, the patient had a biopsy-confirmed posttransplant lymphoproliferative disorder before positron emission tomography scanning and positron emission tomography was performed for staging purposes. In the remaining 125 cases, positron emission tomography was performed to differentiate between posttransplant lymphoproliferative disorder and other diseases. 18F-fluorodeoxyglucose-uptake was quantitatively expressed by calculation of maximum and mean standardized uptake value in the most intense lesion or, in the absence of attenuation corrected positron emission tomography scans, by comparing uptake in target lesion to liver and mediastinal uptake. We found an overall sensitivity of 89%, specificity of 89%, positive predictive value of 91% and negative predictive value of 87% for posttransplant lymphoproliferative disorder detection by 18F-fluorodeoxyglucose-positron emission tomography. In a subanalysis of the 125 scans performed for differentiating posttransplant lymphoproliferative disorder from other diseases, sensitivity, specificity, positive predictive value and negative predictive value were 90%, 89%, 85% and 93%, respectively. 18F-fluorodeoxyglucose-uptake in posttransplant lymphoproliferative disorder was generally high with a median mean and maximum standardized uptake

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

    Fokas, A S; Marinakis, V

    2004-01-01

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

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

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

    2011-07-01

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

  14. Molecular Imaging of Transporters with Positron Emission Tomography

    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

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

    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.

  16. Plastic scintillators for positron emission tomography obtained by the bulk polymerization method

    Kapłon, Łukasz; Molenda, Marcin; Moskal, Paweł; Wieczorek, Anna; Bednarski, Tomasz; Białas, Piotr; Czerwiński, Eryk; Korcyl, Grzegorz; Kowal, Jakub; Kowalski, Paweł; Kozik, Tomasz; Krzemień, Wojciech; Niedźwiecki, Szymon; Pałka, Marek; Pawlik, Monika; Raczyński, Lech; Rudy, Zbigniew; Salabura, Piotr; Gupta-Sharma, Neha; Silarski, Michał; Słomski, Artur; Smyrski, Jerzy; Strzelecki, Adam; Wiślicki, Wojciech; Zieliński, Marcin; Zoń, Natalia

    2015-01-01

    This paper describes three methods regarding the production of plastic scintillators. One method appears to be suitable for the manufacturing of plastic scintillator, revealing properties which fulfill the requirements of novel positron emission tomography scanners based on plastic scintillators. The key parameters of the manufacturing process are determined and discussed.

  17. 77 FR 8262 - Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    2012-02-14

    ... HUMAN SERVICES Food and Drug Administration 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 Administration (FDA) is announcing the availability of a draft...

  18. Diagnosis of heterotopic bone marrow in the mediastinum using /sup 52/Fe and positron emission tomography

    Borgies, P. (Cliniques Universitaires Saint-Luc, Brussels (Belgium). Dept. of Hematology; Cliniques Universitaires Saint-Luc, Brussels (Belgium). Dept. of Nuclear Medicine); Ferrant, A. (Louvain Univ., Louvain-la-Neuve (Belgium). Lab. of Positron Emission Tomography); Leners, N.; Michaux, J.L.; Bol, A.; Michel, C.; Cogneau, M.; Sokal, G.

    1989-11-01

    A patient with hereditary spherocytosis was admitted with mediastinal masses on the chest X-ray. /sup 52/Fe and positron emission tomography (PET) showed uptake of /sup 52/Fe in the masses and established the diagnosis of thoracic extra medullary hematopoiesis. (orig.).

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

    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...

  20. Positron emission tomography for serial imaging of the contused adult rat spinal cord.

    Nandoe, R.D.S.; Yu, J.; Seidel, J.; Rahiem, S.T.; Hurtado, A.; Tsui, B.M.; Grotenhuis, J.A.; Pomper, M.G.; Oudega, M.

    2010-01-01

    We investigated whether small-animal positron emission tomography (PET) could be used in combination with computed tomography (CT) imaging techniques for longitudinal monitoring of the injured spinal cord. In adult female Sprague-Dawley rats (n = 6), the ninth thoracic (T9) spinal cord segment was e

  1. Cobalt-55 positron emission tomography of ipsilateral thalamic and crossed cerebellar hypometabolism after supratentorial ischaemic stroke

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

    1999-01-01

    Cobalt-55 (Co-55) is a positron emission tomography (PET) tracer used to demonstrate brain damage, possibly associated to calcium-mediated processes. The degree of Co-55 accumulation correlates with the severity of ischaemia in stroke patients. It is still a matter of debate whether ipsilateral thal

  2. Positron emission tomography in presurgical diagnosis of partial epilepsies. Praeoperative Lokalisationsdiagnostik bei fokaler Epilepsie durch PET

    Hajek, M.; Leenders, K.L. (Universitaetsspital Zurich (Switzerland). Neurologische Klinik Paul Scherrer Institut, Villigen (Switzerland)); Wieser, H.G. (Universitaetsspital Zurich (Switzerland). Neurologische Klinik)

    1992-06-01

    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.).

  3. Positron emission tomography (PET) methodology for small animals and its application in radiopharmaceutical preclinical investigation

    Hume, Susan P.; Jones, Terry

    1998-11-01

    The use and usefulness of positron emission tomography (PET) to quantify the specific and selective in vivo binding of radioligands in small laboratory animals is briefly reviewed up to the end of 1996. Emphasis is placed on practical experience with a dedicated, small diameter, tomograph (built in collaboration with CTI, Knoxville, TN), implementing conventional PET methodology.

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

    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. Met

  5. Detection of unknown primary head and neck tumors by positron emission tomography

    Braams, JW; Pruim, J; Kole, AC; Nikkels, PGJ; Vaalburg, W; Vermey, A; Roodenburg, JLN

    1997-01-01

    The purpose of this study was to investigate the potential of using positron emission tomography (PET) with F-18-labeled fluoro-2-deoxy-D-glucose (FDG) to detect unknown primary tumors of cervical metastases. Thirteen patients with various histologic types of cervical metastases of unknown primary o

  6. Positron emission tomography/computed tomography for optimized colon cancer staging and follow up

    Engelmann, Bodil Elisabeth; Loft, Annika; Kjær, Andreas;

    2014-01-01

    OBJECTIVES: Optimal management of colon cancer (CC) requires detailed assessment of extent of disease. This study prospectively investigates the diagnostic accuracy of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (PET/CT) for staging and detection of recurrence...

  7. Predictive value of early F-18-fluoro-deoxyglucose positron emission tomography in chemosensitive relapsed lymphoma

    Schot, B; van Imhoff, G; Pruim, J; Sluiter, W; Vaalburg, W; Vellenga, E

    2003-01-01

    F-18-fluoro-deoxyglucose (FDG) positron emission tomography (PET) might be a better tool than computerized tomography (CT) in predicting long-term treatment outcome in patients with relapsed chemosensitive lymphoma who are candidates for autologous stem cell transplantation (ASCT). We studied patien

  8. High-density avalanche chambers for positron emission tomography

    Manfrass, P.; Enghardt, W.; Fromm, W.D.; Wohlfarth, D.; Hohmuth, K.

    1988-12-15

    A positron tomograph for radiopharmaceutical and medical research is under construction. In its final stage it will cover six high-density avalanche chambers (HIDAC) in a hexagonal arrangement. Each detector with a sensitive area of 50x28 cm/sup 2/ will consist of a stack of four pairs of multihole photon-to-electron converters with a multiwire proportional counter (MWPC) in between. An experimental investigation of detector properties as time and spatial resolutions as well as detector efficiency in dependence to converter structure, electric field strength and counting gas mixture preceded the final design of these detectors. Results of these studies are outlined. Furthermore, longitudinal tomograms taken with a stationary test camera are presented.

  9. Non-invasive studies of multiphase flow in process equipment. Positron emission particle tracking technique

    Balakin, B. V.; Adamsen, T. C. H.; Chang, Y.-F.; Kosinski, P.; Hoffmann, A. C.

    2017-01-01

    Positron emission particle tracking (PEPT) is a novel experimental technique for non-invasive inspection of industrial fluid/particle flows. The method is based on the dynamic positioning of a positron-emitting, flowing object (particle) performed through the sensing of annihilation events and subsequent numerical treatment to determine the particle position. The present paper shows an integrated overview of PEPT studies which were carried out using a new PET scanner in the Bergen University Hospital to study multiphase flows in different geometric configurations.

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

    Lee, Dongwon [Los Alamos National Laboratory; Cowee, Misa [Los Alamos National Laboratory; Fenimore, Ed [Los Alamos National Laboratory; Galassi, Mark [Los Alamos National Laboratory; Looker, Quinn [Los Alamos National Laboratory; Mcneil, Wendy V [Los Alamos National Laboratory; Stonehill, Laura [Los Alamos National Laboratory; Wallace, Mark [Los Alamos National Laboratory

    2009-01-01

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

  11. No effects of short-term GSM mobile phone radiation on cerebral blood flow measured using positron emission tomography.

    Kwon, Myoung Soo; Vorobyev, Victor; Kännälä, Sami; Laine, Matti; Rinne, Juha O; Toivonen, Tommi; Johansson, Jarkko; Teräs, Mika; Joutsa, Juho; Tuominen, Lauri; Lindholm, Harri; Alanko, Tommi; Hämäläinen, Heikki

    2012-04-01

    The present study investigated the effects of 902.4 MHz global system for mobile communications (GSM) mobile phone radiation on cerebral blood flow using positron emission tomography (PET) with the (15) O-water tracer. Fifteen young, healthy, right-handed male subjects were exposed to phone radiation from three different locations (left ear, right ear, forehead) and to sham exposure to test for possible exposure effects on brain regions close to the exposure source. Whole-brain [¹⁵O]H₂O-PET images were acquired 12 times, 3 for each condition, in a counterbalanced order. Subjects were exposed for 5 min in each scan while performing a simple visual vigilance task. Temperature was also measured in the head region (forehead, eyes, cheeks, ear canals) during exposure. The exposure induced a slight temperature rise in the ear canals but did not affect brain hemodynamics and task performance. The results provided no evidence for acute effects of short-term mobile phone radiation on cerebral blood flow.

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

    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.

  13. Positron-Cyclotron Maser for the Core Emissions from Pulsars

    Ma, C; Wang, D; Wu, X; Ma, Chun-yu; Mao, Ding-yi; Wang, De-yu; Wu, Xin-ji

    1997-01-01

    We use the cyclotron-maser theory to explain the core emission from the magnetosphere of pulsars. As a kind of direct and efficient maser type of emission, it can give rise to escaping radiation with extremely high brightness temperature and narrow angle with respect to the magnetic axis. We find that the growth rates and real frequencies of the O-mode electromagnetic wave propagating parallel to the magnetic fields depend on the ratio of the plasma frequency $\\omega_p$ and the gyrofrequency $\\omega_b$ rather than the plasma frequency alone, as described by other models. The emission takes place in the region where the magnitude of $\\omega_p/\\omega_b$ is $10^{-2}$. The corresponding altitude is about a few decades of neutron star radius, where the magnetic field strength is about $10^6-10^8 G$. The qualitative spectrum and the lower frequency cut-off of the radio emission is obtained by this model.

  14. Stimulus rate dependence of regional cerebral blood flow in human striate cortex, demonstrated by positron emission tomography

    Fox, P.T.; Raichle, M.E.

    1984-05-01

    The purpose of this investigation was to determine the relationship between the repetition rate of a simple sensory stimulus and regional cerebral blood flow (rCBF) in the human brain. Positron emission tomography (PET), using intravenously administered H/sub 2/(/sup 15/)O as the diffusible blood-flow tracer, was employed for all CBF measurements. The use of H/sub 2/(/sup 15/)O with PET allowed eight CBF measurements to be made in rapid sequence under multiple stimulation conditions without removing the subject from the tomograph. Nine normal volunteers each underwent a series of eight H2(/sup 15/)O PET measurements of CBF. Initial and final scans were made during visual deprivation. The six intervening scans were made during visual activation with patterned-flash stimuli given in random order at 1.0-, 3.9-, 7.8-, 15.5-, 33.1-, and 61-Hz repetition rates. The region of greatest rCBF increase was determined. Within this region the rCBF was determined for every test condition and then expressed as the percentage change from the value of the initial unstimulated scan (rCBF% delta). In every subject, striate cortex rCBF% delta varied systematically with stimulus rate. Between 0 and 7.8 Hz, rCBF% delta was a linear function of stimulus repetition rate. The rCBF response peaked at 7.8 Hz and then declined. The rCBF% delta during visual stimulation was significantly greater than that during visual deprivation for every stimulus rate except 1.0 Hz. The anatomical localization of the region of peak rCBF response was determined for every subject to be the mesial occipital lobes along the calcarine fissure, primary visual cortex. Stimulus rate is a significant determinant of rCBF response in the visual cortex. Investigators of brain responses to selective activation procedures should be aware of the potential effects of stimulus rate on rCBF and other measurements of cerebral metabolism.

  15. Alterations in CNS Activity Induced by Botulinum Toxin Treatment in Spasmodic Dysphonia: An H[subscript 2][superscript 15]O PET Study

    Ali, S. Omar; Thomassen, Michael; Schulz, Geralyn M.; Hosey, Lara A.; Varga, Mary; Ludlow, Christy L.; Braun, Allen R.

    2006-01-01

    Speech-related changes in regional cerebral blood flow (rCBF) were measured using H[subscript 2][superscript 15]O positron-emission tomography in 9 adults with adductor spasmodic dysphonia (ADSD) before and after botulinum toxin (BTX) injection and 10 age- and gender-matched volunteers without neurological disorders. Scans were acquired at rest…

  16. Single-photon emission computed tomography and positron-emission tomography assays for tissue oxygenation.

    Chapman, J D; Schneider, R F; Urbain, J L; Hanks, G E

    2001-01-01

    Radiotherapy prescription can now be customized to target the major mechanism(s) of resistance of individual tumors. In that regard, functional imaging techniques should be exploited to identify the dominant mechanism(s). Tumor biology research has identified several mechanisms of tumor resistance that may be unique to radiation treatments. These fall into 3 broad areas associated with (1) tumor hypoxic fraction, (2) tumor growth rate, (3) and the intrinsic radiosensitivity of tumor clonogens. Imaging research has markers in various stages of development for quantifying relevant information about each of these mechanisms, and those that measure tumor oxygenation and predict for radioresistance are the most advanced. Positron-emission tomography (PET) measurement of oxygen 15 has yielded important information, particularly about brain tissue perfusion, metabolism, and function. Indirect markers of tumor hypoxia have exploited the covalent binding of bioreductive intermediates of azomycin-containing compounds whose uptakes are inversely proportional to intracellular oxygen concentrations. Pilot clinical studies with single-photon emission computed tomography (SPECT) and PET detection of radiolabeled markers to tumor hypoxia have been reported. Recently, other studies have attempted to exploit the reduction properties of both technetium and copper chelates for the selective deposition of radioactive metals in hypoxic tissues. A growing number of potentially useful isotopes are now available for labeling several novel chemicals that could have the appropriate specificity and sensitivity. Preclinical studies with "microSPECT" and "microPET" will be important to define the optimal radiodiagnostic(s) for measuring tissue oxygenation and for determining the time after their administration for optimal hypoxic signal acquisition. Radiolabeled markers of growth kinetics and intrinsic radiosensitivity of cells in solid tumors are also being developed. We conclude that

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

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

    2001-01-01

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

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

    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.

  19. Positron emission tomography scanning is coming to a hospital near you soon!

    Bashir, Humayun; Shabo, Gregory; Nunan, T O

    2008-04-01

    Positron emission tomography (PET) is still generally not available in the UK; however, there are plans to introduce a national service in England from April 2008. Plans are also at an advanced stage in Scotland and Wales. The main uses of PET are in preoperative staging of lung cancer, detection of recurrent colorectal cancer, and management of patients with lymphoma. Although these provide the bulk of the referral base, PET is also of use in specific situations in patients with less common cancers, such as head and neck cancer, gynaecological cancer, and melanoma. In its more common uses, PET has been shown to be cost effective. Positron emission tomography will play an increasing role in the evaluation of response to treatment to enable early separation of patients who are responding well to chemotherapy from those who are not responding and need to be transferred to another therapy.

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

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

    2011-01-01

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

  1. Usefulness of myocardial positron emission tomography/nuclear imaging in Takotsubo cardiomyopathy

    Marzia; Testa; Mauro; Feola

    2014-01-01

    AIM:To analyse and summarize all the articles related to positron emission tomography and Takotsubo cardiomyopathy(TTC).METHODS:We performed a systematic review of the existing literature on positron emission tomography/nuclear imaging and Takotsubo cardiomyopathy using PUBMED database.We combined search terms such as"takotsubo","takotsubo syndrome","myocardial positron emission tomography","positron emission tomography".All case reports were excluded.The list included only four articles which were reviewed by two independent investigators.It was not possible to undertake a formal meta-analysis because of the heterogeneity of the studies;therefore,we made a narrative synthesis of the collected data.RESULTS:Nuclear medicine techniques can be useful employed in the differential diagnosis of TTC from an acute coronary syndrome(ACS).In fact,transient left ventricular(LV)apical ballooning is a syndrome frequently misdiagnosed as an ACS and can mimic symptoms of myocardial infarction with ST-T segments changes on electrocardiography(ECG),a limited re-lease of myocardial enzyme,mainly reported after sudden emotional or physical stress,and an akinesis or dyskinesis of the left ventricle apex which are completely reversible in a few weeks.In the studies included in this review,nuclear medicine techniques have demonstrated a discrepancy between normal perfusion and a reduced glucose utilization in TTC,commonly known as"inverse flow metabolism mismatch".This suggests that apical ballooning represents a transient metabolic disorder on the cellular level,rather than a structural contractile disease of the myocardium,due to a transient decrease of glucose metabolism that might be related to a coronary microcirculation impairment followed by prolonged myocardial stunning.CONCLUSION:Nuclear medicine techniques can be usefully used for the diagnosis of TTC and can increase our knowledge of the pathophysiological mechanisms of TTC.

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

    CHAI Pei; SHAN BaoCi

    2009-01-01

    A method has been developed to establish the crystal position look-up table for positron emission tomography with block detectors.It is based on the principle that the counts in crystal position histogram obey the Gaussian mixture model(GMM).This method has taken full consideration of the characteristics of the GMM and the detector itself.The experimental results have proved that it is simple,reliable,and universal.

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

    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 s...... study investigates the positive (PPV) and negative predictive value (NPV) of PET-CT in stage I disease and the clinical impact of the scan results in all disease stages....

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

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

    1982-04-01

    Primary considerations for the design of positron emission tomographs for medical studies in humans are the need for high imaging sensitivity, whole organ coverage, good spatial resolution, high maximum data rates, adequate spatial sampling with minimum mechanical motion, shielding against out of plane activity, pulse height discrimination against scattered photons, and timing discrimination against accidental coincidences. We discuss the choice of detectors, sampling motion, shielding, and electronics to meet these objectives.

  5. Imaging Chronic Pain and Inflammation : Positron Emission Tomography Studies of Whiplash Associated Disorder

    2008-01-01

    This thesis is on chronic neck pain after a rear impact car injury, so called whiplash associated disorder (WAD). Three empirical studies using positron emission tomography (PET) with different radioligands have been performed. The first study evaluated resting state regional cerebral blood flow (rCBF) in WAD patients and in healthy, pain-free controls, by use of oxygen-15 labeled water. Patients had heightened resting rCBF bilaterally in the posterior parahippocampal and the posterior cingul...

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

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

    1982-04-01

    Primary considerations for the design of positron emission tomographs for medical studies in humans are the need for high imaging sensitivity, whole organ coverage, good spatial resolution, high maximum data rates, adequate spatial sampling with minimum mechanical motion, shielding against out of plane activity, pulse height discrimination against scattered photons, and timing discrimination against accidental coincidences. We discuss the choice of detectors, sampling motion, shielding, and electronics to meet these objectives.

  7. Fluorodeoxyglucose positron emission tomography in the evaluation of germ cell tumours at relapse

    Hain, S F; O’Doherty, M J; Timothy, A R; Leslie, M D; Harper, P. G.; Huddart, R A

    2000-01-01

    Differentiation of active disease from fibrosis/mature teratoma in patients with residual masses or identifying of sites of recurrence in patients with raised markers following treatment of their testicular cancer remains a problem.18F-fluorodeoxyglucose positron emission tomography (FDG-PET) has the potential to identify active disease and thereby influence further management in these patients. We performed a retrospective study of the use of FDG-PET in detecting residual/recurrent testicula...

  8. Tomography by positrons emission: integral unit to the service of Mexico; Tomografia por emision de positrones: unidad integral al servicio de Mexico

    Lopez D, F.A. [Unidad PET-Ciclotron, Facultad de Medicina, UNAM (Mexico)]. e-mail: fred-alonso@correo.unam.mx

    2005-07-01

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

  9. Targeted positron emission tomography imaging of CXCR4 expression in patients with acute myeloid leukemia.

    Herhaus, Peter; Habringer, Stefan; Philipp-Abbrederis, Kathrin; Vag, Tibor; Gerngross, Carlos; Schottelius, Margret; Slotta-Huspenina, Julia; Steiger, Katja; Altmann, Torben; Weißer, Tanja; Steidle, Sabine; Schick, Markus; Jacobs, Laura; Slawska, Jolanta; Müller-Thomas, Catharina; Verbeek, Mareike; Subklewe, Marion; Peschel, Christian; Wester, Hans-Jürgen; Schwaiger, Markus; Götze, Katharina; Keller, Ulrich

    2016-08-01

    Acute myeloid leukemia originates from leukemia-initiating cells that reside in the protective bone marrow niche. CXCR4/CXCL12 interaction is crucially involved in recruitment and retention of leukemia-initiating cells within this niche. Various drugs targeting this pathway have entered clinical trials. To evaluate CXCR4 imaging in acute myeloid leukemia, we first tested CXCR4 expression in patient-derived primary blasts. Flow cytometry revealed that high blast counts in patients with acute myeloid leukemia correlate with high CXCR4 expression. The wide range of CXCR4 surface expression in patients was reflected in cell lines of acute myeloid leukemia. Next, we evaluated the CXCR4-specific peptide Pentixafor by positron emission tomography imaging in mice harboring CXCR4 positive and CXCR4 negative leukemia xenografts, and in 10 patients with active disease. [(68)Ga]Pentixafor-positron emission tomography showed specific measurable disease in murine CXCR4 positive xenografts, but not when CXCR4 was knocked out with CRISPR/Cas9 gene editing. Five of 10 patients showed tracer uptake correlating well with leukemia infiltration assessed by magnetic resonance imaging. The mean maximal standard uptake value was significantly higher in visually CXCR4 positive patients compared to CXCR4 negative patients. In summary, in vivo molecular CXCR4 imaging by means of positron emission tomography is feasible in acute myeloid leukemia. These data provide a framework for future diagnostic and theranostic approaches targeting the CXCR4/CXCL12-defined leukemia-initiating cell niche.

  10. Combined use of positron emission tomography and volume doubling time in lung cancer screening with low-dose CT scanning

    Ashraf, H; Dirksen, A; Jakobsen, Annika Loft

    2011-01-01

    In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules.......In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules....

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

    Wuest, F

    2005-12-01

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

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

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

    1989-09-01

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

  13. Respiratory motion in positron emission tomography for oncology applications: Problems and solutions

    Visvikis, D. [INSERM U650, LaTIM, University Hospital Medical School, F-29609, Brest (France)]. E-mail: Visvikis.Dimitris@univ-brest.fr; Lamare, F. [INSERM U650, LaTIM, University Hospital Medical School, F-29609, Brest (France); Bruyant, P. [INSERM U650, LaTIM, University Hospital Medical School, F-29609, Brest (France); Boussion, N. [INSERM U650, LaTIM, University Hospital Medical School, F-29609, Brest (France); Cheze Le Rest, C. [INSERM U650, LaTIM, University Hospital Medical School, F-29609, Brest (France)

    2006-12-20

    The effect of physiological motion in emission tomography is a reduction in overall image contrast and loss of sensitivity. In particular, respiratory motion affects imaging in the thoracic and the upper abdomen area, leading to a reduction in lesion detection as a result of the associated blurring. Furthermore, respiratory motion leads to a compromise in quantitative accuracy in terms of functional volume determination and activity concentration recovery for oncology imaging. This paper presents a review of the current state of the art in the implementation of respiratory motion compensation techniques in positron emission tomography (PET) imaging for oncology applications.

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

    Jicha M.

    2013-04-01

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

  15. Geneva University - The AX-PET experiment : A demonstrator for an axial Positron Emission Tomography

    Université de Genève

    2012-01-01

    Geneva University École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92   Wednesday 14 March 2012 SEMINAIRE DE PHYSIQUE CORPUSCULAIRE 11.15 a.m. - Science II, Auditoire 1S081, 30, quai Ernest-Ansermet, 1211 Genève 4 The AX-PET experiment : A demonstrator for an axial Positron Emission Tomography Dr Chiara CASELLA   ETH Zurich   PET (Positron Emission Tomography) is a tool for in-vivo functional imaging, successfully used since the earliest days of nuclear medicine. It is based on the detection of the two coincident 511 keV photons from the annihilation of a positron, emitted from a radiotracer injected into the body. Tomographic analysis of the coincidence data allows for a 3D reconstructed image of the source distribution. The AX-PET experiment proposes a novel geometrical approach for a PET scanner, in which l...

  16. Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons.

    Sato, K; Kobayashi, Y

    2015-05-01

    Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed.

  17. Cosmic Ray Electrons, Positrons and the Synchrotron emission of the Galaxy: consistent analysis and implications

    Di Bernardo, Giuseppe; Gaggero, Daniele; Grasso, Dario; Maccione, Luca

    2012-01-01

    A multichannel analysis of cosmic ray electron and positron spectra and of the diffuse synchrotron emission of the Galaxy is performed by using the DRAGON code. This study is aimed at probing the interstellar electron source spectrum down to E ~ 1 GeV and at constraining several propagation parameters. We find that above 4 GeV the electron source spectrum is compatible with a power-law of index -2.5. Below 4 GeV instead it must be significantly suppressed and the total lepton spectrum is dominated by secondary particles. The positron spectrum and fraction measured below a few GeV are consistently reproduced only within low reacceleration models. We also constrain the scale-height zt of the cosmic-ray distribution using three independent (and, in two cases, original) arguments, showing that values of z_t < 2 kpc are excluded. This result may have strong implications for particle dark matter searches.

  18. Positron emission tomography imaging of the glucagon-like peptide-1 receptor in healthy and streptozotocin-induced diabetic pigs

    Nalin, Lovisa; Andreasson, Susanne; Wikstrand, Anna; Ryden, Anneli; Nyman, Goerel; Jensen-Waern, Marianne [Swedish University of Agricultural Sciences, Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Science, Uppsala (Sweden); Selvaraju, Ram K.; Eriksson, Olof [Uppsala University, Department of Medicinal Chemistry, Preclinical PET Platform, Uppsala (Sweden); Velikyan, Irina [Uppsala University, Department of Medicinal Chemistry, Preclinical PET Platform, Uppsala (Sweden); Uppsala University, Department of Radiology, Oncology and Radiation Sciences, Uppsala (Sweden); Uppsala University Hospital, PET Centre, Centre for Medical Imaging, Uppsala (Sweden); Berglund, Marie [Uppsala University, Department of Medicinal Chemistry, Preclinical PET Platform, Uppsala (Sweden); Uppsala University, Department of Radiology, Oncology and Radiation Sciences, Uppsala (Sweden); Lubberink, Mark [Uppsala University, Department of Radiology, Oncology and Radiation Sciences, Uppsala (Sweden); Kandeel, Fouad [Beckman Research Institute of the City of Hope, Duarte, CA (United States); Korsgren, Olle [Uppsala University, Department of Immunology, Genetics and Pathology, Uppsala (Sweden)

    2014-09-15

    The glucagon-like peptide-1 receptor (GLP-1R) has been proposed as a target for molecular imaging of beta cells. The feasibility of non-invasive imaging and quantification of GLP-1R in pancreas using the positron emission tomography (PET) tracer [{sup 68}Ga]Ga-DO3A-VS-Cys{sup 40}-Exendin-4 in non-diabetic and streptozotocin (STZ)-induced diabetic pigs treated with insulin was investigated. Non-diabetic (n = 4) and STZ-induced diabetic pigs (n = 3) from the same litter were examined. Development of diabetes was confirmed by blood glucose values, clinical examinations and insulin staining of pancreatic sections post mortem. Tissue perfusion in the pancreas and kidneys was evaluated by [{sup 15}O]water PET/computed tomography (CT) scans. The in vivo receptor specificity of [{sup 68}Ga]Ga-DO3A-VS-Cys{sup 40}-Exendin-4 was assessed by administration of either tracer alone or by competition with 3-6.5 μg/kg of Exendin-4. Volume of distribution and occupancy in the pancreas were quantified with a single tissue compartment model. [{sup 15}O]water PET/CT examinations showed reduced perfusion in the pancreas and kidneys in diabetic pigs. [{sup 68}Ga]Ga-DO3A-VS-Cys{sup 40}-Exendin-4 uptake in the pancreas of both non-diabetic and diabetic pigs was almost completely abolished by co-injection of unlabeled Exendin-4 peptide. [{sup 68}Ga]Ga-DO3A-VS-Cys{sup 40}-Exendin-4 uptake did not differ between non-diabetic and diabetic pigs. In all animals, administration of the tracer resulted in an immediate increase in the heart rate (HR). Pancreatic uptake of [{sup 68}Ga]Ga-DO3A-VS-Cys{sup 40}-Exendin-4 was not reduced by destruction of beta cells in STZ-induced diabetic pigs. (orig.)

  19. Kinetic Analysis of Dynamic Positron Emission Tomography Data using Open-Source Image Processing and Statistical Inference Tools.

    Hawe, David; Hernández Fernández, Francisco R; O'Suilleabháin, Liam; Huang, Jian; Wolsztynski, Eric; O'Sullivan, Finbarr

    2012-05-01

    In dynamic mode, positron emission tomography (PET) can be used to track the evolution of injected radio-labelled molecules in living tissue. This is a powerful diagnostic imaging technique that provides a unique opportunity to probe the status of healthy and pathological tissue by examining how it processes substrates. The spatial aspect of PET is well established in the computational statistics literature. This article focuses on its temporal aspect. The interpretation of PET time-course data is complicated because the measured signal is a combination of vascular delivery and tissue retention effects. If the arterial time-course is known, the tissue time-course can typically be expressed in terms of a linear convolution between the arterial time-course and the tissue residue. In statistical terms, the residue function is essentially a survival function - a familiar life-time data construct. Kinetic analysis of PET data is concerned with estimation of the residue and associated functionals such as flow, flux, volume of distribution and transit time summaries. This review emphasises a nonparametric approach to the estimation of the residue based on a piecewise linear form. Rapid implementation of this by quadratic programming is described. The approach provides a reference for statistical assessment of widely used one- and two-compartmental model forms. We illustrate the method with data from two of the most well-established PET radiotracers, (15)O-H(2)O and (18)F-fluorodeoxyglucose, used for assessment of blood perfusion and glucose metabolism respectively. The presentation illustrates the use of two open-source tools, AMIDE and R, for PET scan manipulation and model inference.

  20. [Study of regional cerebral glucose metabolism, in man, while awake or asleep, by positron emission tomography].

    Franck, G; Salmon, E; Poirrier, R; Sadzot, B; Franco, G

    1987-03-01

    Measurements of regional cerebral glucose uptake by the 18F-fluorodeoxyglucose technique (18FDG) and positron emission tomography (PET) along with polygraph recordings were made serially during relaxed wakefulness and different stages of nocturnal sleep in two right-handed normal volunteers. During stage III-IV sleep, values declined diffusely in both hemispheric regions (-31%), thalamus (-33%), cerebellum (-33%) and brain stem (-25%). During paradoxical sleep regional values increased diffusely compared with slow wave sleep. Compared to wakefulness, regional metabolic values seemed to increase but the results were more variable from one volunteer to the other. These preliminary data indicate important regional alterations in cerebral metabolism between sleep states.

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

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

    2016-09-15

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

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

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

    1984-09-01

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

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

    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......) and the brain stem. A direct comparison between wind-up pain and pressure pain revealed that both activated a largely overlapping network. Since no de novo brain areas were activated by wind-up pain, our data suggest that the processes specific to wind-up pain do not occur at the cerebral level....

  4. Synthesis of analogues of (-)-cytisine for in vivo studies of nicotinic receptors using positron emission tomography.

    Marrière, E; Rouden, J; Tadino, V; Lasne, M C

    2000-04-20

    [formula: see text] 9-Substituted analogues of (-)-cytisine were synthesized in high yields via palladium-mediated couplings of either 9-(-)-bromocytisine and organostannanes or 9-(-)-trimethylstannylcytisine and fluorobromobenzene. The protection of the amine with a nitroso group and the use of PdCl2(PPh3)2 to carry out the Stille reaction allowed the rapid synthesis of 9-(4'-[18F]fluorophenyl)cytisine (18F: t1/2 = 109.7 min), a new promising radioligand (radiochemical yield: 10% from [18F]KF, 150 min, four steps) for positron emission tomography studies of alpha 4 beta 2 nicotinic receptors.

  5. Fluorodeoxyglucose positron emission tomography (FDG-PET) for monitoring lymphadenopathy in the autoimmune lymphoproliferative syndrome (ALPS).

    Rao, V Koneti; Carrasquillo, Jorge A; Dale, Janet K; Bacharach, Stephen L; Whatley, Millie; Dugan, Faith; Tretler, Jean; Fleisher, Thomas; Puck, Jennifer M; Wilson, Wyndham; Jaffe, Elaine S; Avila, Nilo; Chen, Clara C; Straus, Stephen E

    2006-02-01

    Autoimmune lymphoproliferative syndrome (ALPS) is associated with mutations that impair the activity of lymphocyte apoptosis proteins, leading to chronic lymphadenopathy, hepatosplenomegaly, autoimmunity, and an increased risk of lymphoma. We investigated the utility of fluorodeoxyglucose positron emission tomography (FDG-PET) in discriminating benign from malignant lymphadenopathy in ALPS. We report that FDG avidity of benign lymph nodes in ALPS can be high and, hence, by itself does not imply presence of lymphoma; but FDG-PET can help guide the decision for selecting which of many enlarged nodes in ALPS patients to biopsy when lymphoma is suspected.

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

    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......Lung cancer is the cause of 32% of all male cancer deaths and 25% of all female cancer deaths. Because the prognosis depends on early diagnosis and staging, continuous evaluation of the diagnostic tools available is important. The aim of this study was to assess the diagnostic value of dedicated...

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

    Wiggins, Cody; Santos, Roque; Ruggles, Arthur

    2017-01-01

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

  8. Neuro-imaging and positron emission tomography of congenital homonymous hemianopsia.

    Bosley, T M; Kiyosawa, M; Moster, M; Harbour, R; Zimmerman, R; Savino, P J; Sergott, R C; Alavi, A; Reivich, M

    1991-04-15

    Congenital homonymous hemianopsia is an uncommon asymptomatic visual field defect discovered typically in young adult life that is caused by a diverse group of insults to the retrochiasmal afferent visual system occurring prenatally, at birth, or during early childhood. We treated eight patients with congenital homonymous hemianopsia; seven with damage involving the optic radiations and one with an abnormality of the optic tract. We performed positron emission tomography using 18F-fluoro-2-deoxyglucose on two patients with dense homonymous hemianopsias, lesions of the contralateral optic radiations, and largely intact occipital cortex. These studies showed minimal abnormalities in resting visual cortex glucose metabolism of the affected visual cortex.

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

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

    1985-01-01

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

  10. Benign breast lesions detected by positron emission tomography-computed tomography

    Benveniste, Ana P., E-mail: apbenveniste@mdanderson.org [Department of Diagnostic Radiology,The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Yang, Wei, E-mail: wyang@mdanderson.org [Department of Diagnostic Radiology,The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Benveniste, Marcelo F., E-mail: mfbenveniste@mdanderson.org [Department of Diagnostic Radiology,The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Mawlawi, Osama R., E-mail: omawlawi@mdanderson.org [Department of imaging physics, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Marom, Edith M., E-mail: emarom@mdanderson.org [Department of Diagnostic Radiology,The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    {sup 18}F-fluorodeoxyglucose positron emission computed tomography (FDG PET-CT) is widely used in the initial staging and response evaluation of patients with malignancy. This review describes a spectrum of benign breast findings incidentally detected by FDG PET-CT at staging that may be misinterpreted as malignancy. We describe the pattern of distribution and intensity of FDG uptake in a spectrum of benign breast diseases with their corresponding typical morphological imaging characteristics to help the nuclear medicine physician and/or general radiologist identify benign lesions, avoiding unnecessary breast imaging work-up and biopsies.

  11. Sensitivity estimation in time-of-flight list-mode positron emission tomography

    Herraiz, J. L. [Madrid-MIT M+Visión Consortium, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 and Grupo de Física Nuclear, Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, CEI Moncloa, Madrid 28040 (Spain); Sitek, A., E-mail: sarkadiu@gmail.com [Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)

    2015-11-15

    Purpose: An accurate quantification of the images in positron emission tomography (PET) requires knowing the actual sensitivity at each voxel, which represents the probability that a positron emitted in that voxel is finally detected as a coincidence of two gamma rays in a pair of detectors in the PET scanner. This sensitivity depends on the characteristics of the acquisition, as it is affected by the attenuation of the annihilation gamma rays in the body, and possible variations of the sensitivity of the scanner detectors. In this work, the authors propose a new approach to handle time-of-flight (TOF) list-mode PET data, which allows performing either or both, a self-attenuation correction, and self-normalization correction based on emission data only. Methods: The authors derive the theory using a fully Bayesian statistical model of complete data. The authors perform an initial evaluation of algorithms derived from that theory and proposed in this work using numerical 2D list-mode simulations with different TOF resolutions and total number of detected coincidences. Effects of randoms and scatter are not simulated. Results: The authors found that proposed algorithms successfully correct for unknown attenuation and scanner normalization for simulated 2D list-mode TOF-PET data. Conclusions: A new method is presented that can be used for corrections for attenuation and normalization (sensitivity) using TOF list-mode data.

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

    Junsuke Nakase

    Full Text Available PURPOSE: This study investigated the effect of the FIFA 11+ warm-up program on whole body muscle activity using positron emission tomography. METHODS: Ten healthy male volunteers were divided into a control group and a group that performed injury prevention exercises (The 11+. The subjects of the control group were placed in a sitting position for 20 min and 37 MBq of (18F-fluorodeoxyglucose (FDG was injected intravenously. The subjects then remained seated for 45 min. The subjects of the exercise group performed part 2 of the 11+for 20 min, after which FDG was injected. They then performed part 2 of the 11+for 20 min, and rested for 25 min in a sitting position. Positron emission tomography-computed tomography images were obtained 50 min after FDG injection in each group. Regions of interest were defined within 30 muscles. The standardized uptake value was calculated to examine the FDG uptake of muscle tissue per unit volume. RESULTS: FDG accumulation within the abdominal rectus, gluteus medius and minimus were significantly higher in the exercise group than in the control group (P<0.05. CONCLUSION: The hip abductor muscles and abdominal rectus were active during part 2 of the FIFA 11+ program.

  13. Pixelated CdTe detectors to overcome intrinsic limitations of crystal based positron emission mammographs

    De Lorenzo, G.; Chmeissani, M.; Uzun, D.; Kolstein, M.; Ozsahin, I.; Mikhaylova, E.; Arce, P.; Cañadas, M.; Ariño, G.; Calderón, Y.

    2013-01-01

    A positron emission mammograph (PEM) is an organ dedicated positron emission tomography (PET) scanner for breast cancer detection. State-of-the-art PEMs employing scintillating crystals as detection medium can provide metabolic images of the breast with significantly higher sensitivity and specificity with respect to standard whole body PET scanners. Over the past few years, crystal PEMs have dramatically increased their importance in the diagnosis and treatment of early stage breast cancer. Nevertheless, designs based on scintillators are characterized by an intrinsic deficiency of the depth of interaction (DOI) information from relatively thick crystals constraining the size of the smallest detectable tumor. This work shows how to overcome such intrinsic limitation by substituting scintillating crystals with pixelated CdTe detectors. The proposed novel design is developed within the Voxel Imaging PET (VIP) Pathfinder project and evaluated via Monte Carlo simulation. The volumetric spatial resolution of the VIP-PEM is expected to be up to 6 times better than standard commercial devices with a point spread function of 1 mm full width at half maximum (FWHM) in all directions. Pixelated CdTe detectors can also provide an energy resolution as low as 1.5% FWHM at 511 keV for a virtually pure signal with negligible contribution from scattered events.

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

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

    1989-09-01

    One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging. 6 refs., 21 figs.

  15. Diagnostic accuracy of 18F-Fluorodeoxyglucose positron emission tomography in the follow-up of papillary or follicular thyroid cancer.

    Hooft, L.; Hoekstra, O.S.; Devillé, W.; Lips, W.; Teule, J.J.; Boers, M.; Tulder, M.W. van

    2001-01-01

    Positron emission tomography with 18F-fluorodeoxyglucose is a relatively new nuclear imaging technique in oncology. We conducted a systematic review to determine the diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography in patients suspected of recurrent papillary or follicular

  16. In vivo evaluation of [11C]preladenant positron emission tomography for quantification of adenosine A2A receptors in the rat brain

    Zhou, Xiaoyun; Khanapur, Shivashankar; de Jong, Johan R; Willemsen, Antoon T.M.; Dierckx, Rudi Ajo; Elsinga, Philip H; de Vries, Erik Fj

    2016-01-01

    [(11)C]Preladenant was developed as a novel adenosine A2A receptor positron emission tomography radioligand. The present study aims to evaluate the suitability of [(11)C]preladenant positron emission tomography for the quantification of striatal A2A receptor density and the assessment of striatal A2

  17. Cosmic ray electrons, positrons and the synchrotron emission of the Galaxy: consistent analysis and implications

    Bernardo, Giuseppe Di [Department of Physics, University of Gothenburg, SE 412 96 Gothenburg (Sweden); Evoli, Carmelo [II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Gaggero, Daniele [SISSA, Via Bonomea 265, 34136 Trieste (Italy); Grasso, Dario [Dipartimento di Fisica, Università di Siena, Via Roma 56, I-56100 Siena (Italy); Maccione, Luca, E-mail: giuseppe.dibernardo@physics.gu.se, E-mail: carmelo.evoli@desy.de, E-mail: dgaggero@sissa.it, E-mail: dario.grasso@pi.infn.it, E-mail: luca.maccione@lmu.de [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany)

    2013-03-01

    A multichannel analysis of cosmic ray electron and positron spectra and of the diffuse synchrotron emission of the Galaxy is performed by using the DRAGON code. This study is aimed at probing the interstellar electron source spectrum down to E ∼< 1GeV and at constraining several propagation parameters. We find that above 4GeV the e{sup −} source spectrum is compatible with a power-law of index ∼ 2.5. Below 4GeV instead it must be significantly suppressed and the total lepton spectrum is dominated by secondary particles. The positron spectrum and fraction measured below a few GeV are consistently reproduced only within low reacceleration models. We also constrain the scale-height z{sub t} of the cosmic-ray distribution using three independent (and, in two cases, original) arguments, showing that values of z{sub t} ∼< 2kpc are excluded. This result may have strong implications for particle dark matter searches.

  18. Pretargeted Positron Emission Tomography Imaging That Employs Supramolecular Nanoparticles with in Vivo Bioorthogonal Chemistry.

    Hou, Shuang; Choi, Jin-Sil; Garcia, Mitch Andre; Xing, Yan; Chen, Kuan-Ju; Chen, Yi-Ming; Jiang, Ziyue K; Ro, Tracy; Wu, Lily; Stout, David B; Tomlinson, James S; Wang, Hao; Chen, Kai; Tseng, Hsian-Rong; Lin, Wei-Yu

    2016-01-26

    A pretargeted oncologic positron emission tomography (PET) imaging that leverages the power of supramolecular nanoparticles with in vivo bioorthogonal chemistry was demonstrated for the clinically relevant problem of tumor imaging. The advantages of this approach are that (i) the pharmacokinetics (PKs) of tumor-targeting and imaging agents can be independently altered via chemical alteration to achieve the desired in vivo performance and (ii) the interplay between the two PKs and other controllable variables confers a second layer of control toward improved PET imaging. In brief, we utilized supramolecular chemistry to synthesize tumor-targeting nanoparticles containing transcyclooctene (TCO, a bioorthogonal reactive motif), called TCO⊂SNPs. After the intravenous injection and subsequent concentration of the TCO⊂SNPs in the tumors of living mice, a small molecule containing both the complementary bioorthogonal motif (tetrazine, Tz) and a positron-emitting radioisotope ((64)Cu) was injected to react selectively and irreversibly to TCO. High-contrast PET imaging of the tumor mass was accomplished after the rapid clearance of the unreacted (64)Cu-Tz probe. Our nanoparticle approach encompasses a wider gamut of tumor types due to the use of EPR effects, which is a universal phenomenon for most solid tumors.

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

    Mohsen Mashayekhi

    2015-05-01

    Application of a magnetic field perpendicular to the positron diffusion plane prevented the scattering of positrons, and consequently, improved the intrinsic spatial resolution of PET imaging, caused by positron range effects.

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

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

    2014-01-01

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

  1. Risk of malignancy in thyroid incidentalomas detected by (18)f-fluorodeoxyglucose positron emission tomography

    Soelberg, Kerstin; Bonnema, Steen Joop; Brix, Thomas Heiberg

    2012-01-01

    Background: The expanding use of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) has led to the identification of increasing numbers of patients with an incidentaloma in the thyroid gland. We aimed to review the proportion of incidental thyroid cancers found by (18)F-FDG PET...... or PET/computed tomography imaging. Methods: Studies evaluating thyroid carcinomas discovered incidentally in patients or healthy volunteers by (18)F-FDG PET were systematically searched in the PubMed database from 2000 to 2011. The main exclusion criteria were known thyroid disease, lack of assigned...... diagnoses, investigation of diffuse uptake only, or investigation of patients with head and neck cancer, or cancer in the upper part of the thorax. Results: Twenty-two studies met our criteria comprising a total of 125,754 subjects. Of these, 1994 (1.6%) had unexpected focal hypermetabolic activity, while...

  2. Refraction-compensated motion tracking of unrestrained small animals in positron emission tomography.

    Kyme, Andre; Meikle, Steven; Baldock, Clive; Fulton, Roger

    2012-08-01

    Motion-compensated radiotracer imaging of fully conscious rodents represents an important paradigm shift for preclinical investigations. In such studies, if motion tracking is performed through a transparent enclosure containing the awake animal, light refraction at the interface will introduce errors in stereo pose estimation. We have performed a thorough investigation of how this impacts the accuracy of pose estimates and the resulting motion correction, and developed an efficient method to predict and correct for refraction-based error. The refraction model underlying this study was validated using a state-of-the-art motion tracking system. Refraction-based error was shown to be dependent on tracking marker size, working distance, and interface thickness and tilt. Correcting for refraction error improved the spatial resolution and quantitative accuracy of motion-corrected positron emission tomography images. Since the methods are general, they may also be useful in other contexts where data are corrupted by refraction effects.

  3. Design And Development Of A Mammary And Axillary Region Positron Emission Tomography System (maxpet)

    Doshi, N K

    2000-01-01

    Breast cancer is the second leading cause of cancer death in women. Currently, mammography and physical breast examination, both non-invasive techniques, provide the two most effective methods available for screening potential breast cancer patients. During the management of patients, however, several invasive techniques such as axillary lymph node dissection, core biopsies and lumpectomies, are utilized to determine the stage or malignancy of the disease with significant cost and morbidity associated with them. Positron Emission Tomography (PET), using [F-18] fluorodeoxyglucose (FDG) tracer is a sensitive and non-invasive imaging modality that may be a cost-effective alternative to certain invasive procedures. In this project we have developed a low cost, high performance, dedicated PET camera (maxPET) for mammary and axillary region imaging. The system consists of two 15x15 cm2 planar scintillation detector arrays composed of modular detectors operating in coincidence. The modular detectors are comprised of...

  4. 18F-fluorodeoxyglucose positron emission tomography predicts survival of patients with neuroendocrine tumors

    Binderup, Tina; Knigge, Ulrich; Jakobsen, Annika Loft;

    2010-01-01

    -eight prospectively enrolled patients with NE tumors underwent FDG-PET imaging. FDG uptake was quantified by maximal standardized uptake value (SUVmax). The prognostic value of FDG uptake, proliferation index, chromogranin A, and liver metastases were assessed. RESULTS: During the 1-year follow-up, 14 patients died......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...... was the only predictor of progression-free survival (HR, 8.4; P value of FDG-PET for NE tumors, which exceeds the prognostic value of traditional markers such as Ki67, chromogranin A, and liver metastases. FDG-PET may obtain an important role for NE...

  5. Positron Emission Tomography and Magnetic Resonance Imaging of the Brain in Fabry Disease

    Korsholm, Kirsten; Feldt-Rasmussen, Ulla; Granqvist, Henrik;

    2015-01-01

    risk of cerebrovascular disease at a young age in addition to heart and kidney failure. OBJECTIVE: The objective of this study was to assess brain function and structure in the Danish cohort of patients with Fabry disease in a prospective way using 18-fluoro-deoxyglucose (F-18 FDG) positron emission....... CONCLUSION: Our data indicated that, in patients with Fabry disease, MRI is the preferable clinical modality--if applicable--when monitoring cerebral status, as no additional major brain-pathology was detected with FDG-PET.......BACKGROUND: Fabry disease is a rare metabolic glycosphingolipid storage disease caused by deficiency of the lysosomal enzyme α-galactosidase A--leading to cellular accumulation of globotriasylceramide in different organs, vessels, tissues, and nerves. The disease is associated with an increased...

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

    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......). Based on the histology of the tumor biopsy, 14 patients had hepatocellular carcinoma (HCC), 9 patients had focal nodular hyperplasia (FNH), and 10 patients had other types of hepatic tumors. Tumor uptake was evaluated by calculating the maximum and mean standardized uptake value and tumor-to-liver ratio....... RESULTS: Altogether, 120 hepatic lesions (59 HCC, 18 FNH, 30 metastases of different primaries, 9 adenomas, and 4 regenerating nodules of liver cirrhosis) were detected by MRI. The overall tumor detection rate was slightly higher for [11C]MTO (39%) than for [11C]ACE (33%). [11C]ACE was more sensitive...

  7. EndoTOFPET-US a Novel Multimodal Tool for Endoscopy and Positron Emission Tomography

    Garutti, Erika

    2013-01-01

    The EndoTOFPET-US project aims to jointly exploit Time-Of-Flight Positron Emission Tomography (TOFPET) and ultrasound endoscopy with a multi-modal instrument for the development of new biomarkers for pancreas and prostate oncology. The paper outlines the functionality of the proposed instrument and the challenges for its realization. The high level of miniaturization and integration poses strong demands to the fields of scintillating crystallography, ultra-fast photon detection, highly integrated electronics and system integration. Solutions are presented to obtain a coincidence time resolution better than 200 ps and a spatial resolution of ~1 mm with an asymmetric TOFPET detector. A tracking system with better than 1 mm spatial resolution precision enables the online alignment of the system. The detector design, the production and test status of the single detector

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

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

    1990-03-01

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

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

    Matthews, Robert; Choi, Minsig

    2016-09-09

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

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

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

    2010-01-12

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

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

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

    2010-01-01

    Prostate cancer is a common cancer in men and continues to be a major health problem. Imaging plays an essential role in the clinical management of patients. An important goal for prostate cancer imaging is more accurate disease characterization through the synthesis of anatomic, functional......, and molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI...... allows functional assessment with techniques such as diffusion-weighted MRI, MR spectroscopy, and dynamic contrast-enhanced MRI. The most common PET radiotracer, (18)F-fluorodeoxyglucose, is not very useful in prostate cancer. However, in recent years other PET tracers have improved the accuracy of PET...

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

    Kim, J; Eberl, S; Feng, D

    2004-01-01

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

  13. Initial characterization of a position-sensitive photodiode/BGO detector for PET (positron emission tomography)

    Derenzo, S.E.; Moses, W.W.; Jackson, H.G.; Turko, B.T.; Cahoon, J.L.; Geyer, A.B.; Vuletich, T.

    1988-11-01

    We present initial results of a position-sensitive photodiode/BGO detector for high resolution, multi-layer positron emission tomography (PET). Position sensitivity is achieved by dividing the 3 mm /times/ 20 mm rectangular photosensitive area along the diagonal to form two triangular segments. Each segment was individually connected to a low-noise amplifier. The photodiodes and crystals were cooled to /minus/100/degree/C to reduce dark current and increase the BGO signal. With an amplifier peaking time of 17 ..mu..sec, the sum of the signals (511 keV photopeak) was 3200 electrons with a full width at half maximum (fwhm) of 750 electrons. The ratio of one signal to the sum determined the depth of interaction with a resolution of 11 mm fwhm. 27 refs., 7 figs.

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

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

    2012-01-01

    Sigma-1 receptor (S1R) radioligands have the potential to detect and monitor various neurological diseases. Herein we report the synthesis, radiofluorination and evaluation of a new S1R ligand 6-(3-fluoropropyl)-3-(2-(azepan-1-yl)ethyl)benzo[d]thiazol-2(3H)-one ([(18)F]FTC-146, [(18)F]13). [(18)F......]13 was synthesized by nucleophilic fluorination, affording a product with >99% radiochemical purity (RCP) and specific activity (SA) of 2.6 ± 1.2 Ci/µmol (n = 13) at end of synthesis (EOS). Positron emission tomography (PET) and ex vivo autoradiography studies of [(18)F]13 in mice showed high uptake...

  15. Hypoxia imaging using Positron Emission Tomography in non-small cell lung cancer: implications for radiotherapy.

    Bollineni, Vikram Rao; Wiegman, Erwin M; Pruim, Jan; Groen, Harry J M; Langendijk, Johannes A

    2012-12-01

    Tumour hypoxia is an important contributor to radioresistance. Thus, increasing the radiation dose to hypoxic areas may result in improved locoregional tumour control. However, this strategy requires accurate detection of the hypoxic sub-volume using PET imaging. Secondly, hypoxia imaging may also provide prognostic information and may be of help to monitor treatment response. Therefore, a systematic review of the scientific literature was carried out on the use of Positron Emission Tomography (PET) to image Tumour hypoxia in non-small cell lung cancer (NSCLC). More specifically, the purpose of this review was (1) to summarize the different hypoxia tracers used, (2) to investigate whether Tumour hypoxia can be detected in NSCLC and finally (3) whether the presence of hypoxia can be used to predict outcome.

  16. Imaging amyloid in Parkinson's disease dementia and dementia with Lewy bodies with positron emission tomography.

    Brooks, David J

    2009-01-01

    Although Parkinson's disease with later dementia (PDD) and dementia with Lewy bodies (DLB) are pathologically characterized by the presence of intraneuronal Lewy inclusion bodies, amyloid deposition is also associated to varying degrees with both these disorders. Fibrillar amyloid load can now be quantitated in vivo with positron emission tomography (PET) using imaging biomarkers. Here the reported findings of 11C-PIB PET studies concerning the amyloid load associated with PD and its influence on dementia are reviewed. It is concluded that the presence of amyloid acts to accelerate the dementia process in Lewy body disorders, though has little influence on its nature. Anti-amyloid strategies could be a relevant approach for slowing dementia in a number of DLB and PDD cases.

  17. A positron emission particle tracking investigation of the flow regimes in tumbling mills

    Govender, I.; Pathmathas, T.

    2017-01-01

    Using positron emission particle tracking (PEPT) data we recover key granular rheology ingredients (velocity, shear rate, volume concentration, bed depth) for developing, testing and calibrating granular flow models. In this regard, 5 mm glass beads were rotated within a 476 mm diameter mill fitted with angled lifter bars along the inner azimuthal walls and operated in batch mode across a range of drum rotation speeds that span cascading and cataracting Froude regimes. After averaging the PEPT outputs into representative volume elements, subsequent continuum analysis of the flowing layer revealed a rich coexistence of flow regimes: a quasi-static layer dominated by frictional interactions, a dense, liquid-like layer that is stressed by frictional and collisional interactions, and an inertial layer that interacts mainly through collisions. Combining the inertial number with an empirically formulated dilatancy law and the measured granular rheological ingredients then facilitated the recovery of the total depth-dependent pressure of the free surface layer.

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

    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

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

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

    2016-01-01

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

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

    Ripa, Rasmus Sejersten; Kjær, Andreas

    2015-01-01

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

  1. Facile synthesis of ( sup 11 C)buprenorphine for positron emission tomographic studies of opioid receptors

    Lever, J.R.; Dannals, R.F.; Wagner, H.N. Jr. (Johns Hopkins Univ., Baltimore, MD (USA). School of Hygiene and Public Health Johns Hopkins Univ., Baltimore, MD (USA). Dept. of Radiology); Mazza, S.M. (Johns Hopkins Univ., Baltimore, MD (USA). School of Hygiene and Public Health); Ravert, H.T.; Wilson, A.A. (Johns Hopkins Univ., Baltimore, MD (USA). Dept. of Radiology)

    1990-01-01

    We have developed a simple and rapid method for the production of buprenorphine (BPN), a potent opioid partial agonist, labelled with carbon-11 at the 6-methoxy position. The procedure uses a precursor synthesized in high yield (89%) from BPN in two steps and employs ({sup 11}C)iodomethane as the radiolabelling reagent. ({sup 11}C)BPN of 97% radiochemical purity can be prepared in high specific activity (41 GBq/{mu}mol; 1120 mCi/{mu}mol) in a radiochemical yield of 10% at end-of-synthesis (not decay corrected). The ({sup 11}C)BPN is available for use in studies of cerebral opioid receptors by positron emission tomography within 24 min from end-of-bombardment, including radiosynthesis, purification, formulation for i.v. injection and determination of specific activity. (author).

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

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

    2002-11-01

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

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

    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.

  4. Serotonin transporter in attention-deficit hyperactivity disorder--preliminary results from a positron emission tomography study.

    Karlsson, Linnea; Tuominen, Lauri; Huotarinen, Antti; Leppämäki, Sami; Sihvola, Elina; Helin, Semi; Sipilä, Maria; Tani, Pekka; Hirvonen, Jussi; Hietala, Jarmo; Karlsson, Hasse

    2013-05-30

    The serotonin transporter (SERT) in attention-deficit hyperactivity disorder (ADHD) patients has not been explored by earlier positron emission tomography (PET) studies. We measured SERT availability in female ADHD patients (n=8) and healthy controls (n=14) with PET and [11C]MADAM as a tracer. No significant group differences in [11C]MADAM binding potential were noted.

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

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

    2001-01-01

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

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

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

    2011-01-01

    Preserved myocardial oxygen consumption estimated by carbon 11-acetate and positron emission tomography (PET) in myocardial regions with chronic but reversibly depressed contractile function in patients with ischemic heart disease have been suggested to be caused by repeated short episodes of acu...

  7. F-18 Fluorodeoxy Glucose Positron Emission Tomography/Computed Tomography Findings in a Rare Case of Penile Leiomyosarcoma

    Kuruva Manohar

    2011-01-01

    Full Text Available Penile cancer is a rare entity accounting for only 0.4% all male malignancies. Penile leiomyosarcomas are even rarer with only around 35 cases reported in literature. We report a rare case of penile leiomyosarcoma illustrating F-18 Fluorodeoxy glucose (FDG positron emission tomography/computed tomography (PET/CT features and histopathology correlation.

  8. The prognostic value of positron emission tomography in non-small cell lung cancer : Analysis of 266 cases

    Kramer, H.; Post, W.J.; Pruim, J.; Groen, H.J.M.

    2006-01-01

    Positron emission tomography (PET) is more accurate than computed tomography (CT) in the staging of non-small cell lung cancer (NSCLC). We analyzed the prognostic value of PET for survival in NSCLC patients. Methods: Consecutive patients with proven NSCLC with PET for staging were selected. Staging

  9. Better yield of (18)fluorodeoxyglucose-positron emission tomography in patients with metastatic differentiated thyroid carcinoma during thyrotropin stimulation

    van Tol, KM; Jager, PL; Piers, DA; Pruim, J; de Vries, EGE; Dullaart, RPF; Links, TP

    2002-01-01

    To determine whether (18)fluorodeoxyglucose-positron emission tomography (FDG-PET) for the detection of recurrences or metastases of differentiated thyroid carcinoma should be performed during thyrotropin (TSH) suppression or TSH stimulation, eight patients were studied sequentially. After the secon

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

    Gewirtz, Henry; Dilsizian, Vasken

    2016-05-31

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

  11. Predicting Outcome in Patients with Rhabdomyosarcoma: Role of [{sup 18}F]Fluorodeoxyglucose Positron Emission Tomography

    Casey, Dana L. [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Wexler, Leonard H. [Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Fox, Josef J. [Department of Nuclear Medicine, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Dharmarajan, Kavita V. [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York (United States); Schoder, Heiko [Department of Nuclear Medicine, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Price, Alison N. [Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Department of Surgery, Temple University School of Medicine, Philadelphia, Pennsylvania (United States); Wolden, Suzanne L., E-mail: woldens@mskcc.org [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States)

    2014-12-01

    Purpose: To evaluate whether [{sup 18}F]fluorodeoxyglucose positron emission tomography (FDG-PET) response of the primary tumor after induction chemotherapy predicts outcomes in rhabdomyosarcoma (RMS). Methods and Materials: After excluding those with initial tumor resection, 107 patients who underwent FDG-PET after induction chemotherapy at Memorial Sloan Kettering Cancer Center from 2002 to 2013 were reviewed. Local control (LC), progression-free survival (PFS), and overall survival (OS) were calculated according to FDG-PET response and maximum standardized uptake value (SUV) at baseline (PET1/SUV1), after induction chemotherapy (PET2/SUV2), and after local therapy (PET3/SUV3). Receiver operator characteristic curves were used to determine the optimal cutoff for dichotomization of SUV1 and SUV2 values. Results: The SUV1 (<9.5 vs ≥9.5) was predictive of PFS (P=.02) and OS (P=.02), but not LC. After 12 weeks (median) of induction chemotherapy, 45 patients had negative PET2 scans and 62 had positive scans: 3-year PFS was 72% versus 44%, respectively (P=.01). The SUV2 (<1.5 vs ≥1.5) was similarly predictive of PFS (P=.005) and was associated with LC (P=.02) and OS (P=.03). A positive PET3 scan was predictive of worse PFS (P=.0009), LC (P=.05), and OS (P=.03). Conclusions: [{sup 18}F]fluorodeoxyglucose positron emission tomography is an early indicator of outcomes in patients with RMS. Future prospective trials may incorporate FDG-PET response data for risk-adapted therapy and early assessment of new treatment regimens.

  12. Effective dose to staff members in a positron emission tomography/CT facility using zirconium-89

    2013-01-01

    Objective: Positron emission tomography (PET) using zirconium-89 (89Zr) is complicated by its complex decay scheme. In this study, we quantified the effective dose from 89Zr and compared it with fluorine-18 fludeoxyglucose (18F-FDG). Methods: Effective dose distribution in a PET/CT facility in Riyadh was calculated by Monte Carlo simulations using MCNPX. The positron bremsstrahlung, the annihilation photons, the delayed gammas from 89Zr and those emissions from 18F-FDG were modelled in the simulations but low-energy characteristic X-rays were ignored. Results: On the basis of injected activity, the dose from 89Zr was higher than that of 18F-FDG. However, the dose per scan from 89Zr became less than that from 18F-FDG near the patient, owing to the difference in injected activities. In the corridor and control rooms, the 89Zr dose was much higher than 18F-FDG, owing to the difference in attenuation by the shielding materials. Conclusion: The presence of the high-energy photons from 89Zr-labelled immuno-PET radiopharmaceuticals causes a significantly higher effective dose than 18F-FDG to the staff outside the patient room. Conversely, despite the low administered activity of 89Zr, it gives rise to a comparable or even lower dose than 18F-FDG to the staff near the patient. This interesting result raises apparently contradictory implications in the radiation protection considerations of a PET/CT facility. Advances in knowledge: To the best of our knowledge, radiation exposure to staff and public in the PET/CT unit using 89Zr has not been investigated. The ultimate output of this study will lead to the optimal design of the facility for routine use of 89Zr. PMID:23934963

  13. Positron emission tomography in pebble beds. Part 1: Liquid particle deposition

    Barth, T., E-mail: t.barth@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (IFD), Bautzner Landstraße 400, 01328 Dresden (Germany); Ludwig, M. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (IFD), Bautzner Landstraße 400, 01328 Dresden (Germany); Kulenkampff, J.; Gründig, M. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology (IRE), Permoserstraße 15, 04318 Leipzig (Germany); Franke, K. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology (IRE), Permoserstraße 15, 04318 Leipzig (Germany); Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmacy (IRP), Permoserstraße 15, 04318 Leipzig (Germany); Lippmann-Pipke, J. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology (IRE), Permoserstraße 15, 04318 Leipzig (Germany); Hampel, U. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (IFD), Bautzner Landstraße 400, 01328 Dresden (Germany); Helmholtz-Zentrum Dresden-Rossendorf, AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering, Technische Universität Dresden, 01062 Dresden (Germany)

    2014-02-15

    Highlights: • Particle deposition in a pebble bed was recorded by positron emission tomography. • The particles were radioactively labelled and their spatial distribution was recorded. • Particle deposition was mainly driven by particle inertia and turbulent dispersion. • Particle deposits form hot spots on the upstream face of the single pebbles. - Abstract: Accidental scenarios such as the depressurisation of the primary circuit of high temperature gas cooled pebble bed reactors may lead to the release of fission products via the discharge of radioactive graphite dust. For a detailed source term assessment in such accident scenarios knowledge of the flow mechanics of dust transport in complex coolant circuit components, like pebble beds, recuperator structures and pipe systems is necessary. In this article an experimental study of aerosol deposition in a pebble bed is described. We investigated the deposition of radiolabelled liquid aerosol particles in a scaled pebble bed in an air-driven small-scale aerosol flow test facility under isothermal ambient conditions. The aerosol particles were generated by means of a condensational aerosol generator with potassium-fluoride (KF) condensation nuclei. Particle concentration measurements upstream and downstream of the pebble bed were performed by isokinetic sampling and particle counting. The results agree with typical deposition curves for turbulent and inertia driven particle deposition. Furthermore, positron emission tomography (PET) was performed to visualize and measure particle deposition distributions in the pebble bed. Results of a selected deposition experiment with moderately large particles (d{sub aero} = 3.5 μm, Re{sup ′}{sub pb}=2200) show that the deposited particles are located in the vicinity of the upstream stagnation points of the pebbles. These findings support the thesis that inertia driven particle deposition is predominating.

  14. A Conway-Maxwell-Poisson (CMP) model to address data dispersion on positron emission tomography.

    Santarelli, Maria Filomena; Della Latta, Daniele; Scipioni, Michele; Positano, Vincenzo; Landini, Luigi

    2016-10-01

    Positron emission tomography (PET) in medicine exploits the properties of positron-emitting unstable nuclei. The pairs of γ- rays emitted after annihilation are revealed by coincidence detectors and stored as projections in a sinogram. It is well known that radioactive decay follows a Poisson distribution; however, deviation from Poisson statistics occurs on PET projection data prior to reconstruction due to physical effects, measurement errors, correction of deadtime, scatter, and random coincidences. A model that describes the statistical behavior of measured and corrected PET data can aid in understanding the statistical nature of the data: it is a prerequisite to develop efficient reconstruction and processing methods and to reduce noise. The deviation from Poisson statistics in PET data could be described by the Conway-Maxwell-Poisson (CMP) distribution model, which is characterized by the centring parameter λ and the dispersion parameter ν, the latter quantifying the deviation from a Poisson distribution model. In particular, the parameter ν allows quantifying over-dispersion (νdispersion (ν>1) of data. A simple and efficient method for λ and ν parameters estimation is introduced and assessed using Monte Carlo simulation for a wide range of activity values. The application of the method to simulated and experimental PET phantom data demonstrated that the CMP distribution parameters could detect deviation from the Poisson distribution both in raw and corrected PET data. It may be usefully implemented in image reconstruction algorithms and quantitative PET data analysis, especially in low counting emission data, as in dynamic PET data, where the method demonstrated the best accuracy.

  15. 18F-AV-1451 positron emission tomography in Alzheimer's disease and progressive supranuclear palsy.

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

    2017-01-24

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

  16. Development of a dedicated positron emission tomography system for the detection and biopsy of breast cancer

    Raylman, Raymond R.; Majewski, Stan; Kross, Brian; Popov, Vladimir; Proffitt, James; Smith, Mark F.; Weisenberger, Andrew G.; Wojcik, Randy

    2006-12-01

    Dedicated positron emission mammography breast imaging systems have shown great promise for the detection of small, radiotracer-avid lesions. Our group (a collaboration consisting of West Virginia University, Jefferson Lab and the University of Washington) is extending this work by developing a positron emission mammography-tomography (PEM-PET) system for imaging and biopsy of breast lesions. The system will have four planar detector heads that will rotate about the breast to acquire multi-view data suitable for tomographic reconstruction. Each detector head will consist of a 96×72 array of 2×2×15 mm 3 LYSO detector elements (pitch=2.1 mm) mounted on a 3×4 array of 5×5 cm 2 flat panel position-sensitive photomultiplier tubes. PEM-PET is expected to have approximately two-millimeter resolution and possess the ability to guide the needle biopsy of suspicious lesions seen on the PET images. Initial tests of the scintillator arrays yielded excellent results. Pixel maps for all four scintillator arrays demonstrated that separation of the LYSO elements was very good; all of the LYSO array elements were observed, even in areas between individual PSPMTs. System energy resolution was measured to be 25% FWHM at 511 keV. Future work includes the use of field programmable gate arrays (FPGAs) to replace the current VME-based data acquisition system, a PSPMT gain normalization procedure to help improve response uniformity and energy resolution, and the addition of an x-ray source and detector to produce multi-modality PEM-PET-CT images of the breast.

  17. Implementation of sum-peak method for standardization of positron emission radionuclides; Implementacao do metodo pico-soma para padronizacao de radionuclideos emissores de positrons

    Fragoso, Maria da Conceicao de Farias; Oliveira, Mercia Liane de; Lima, Fernando Roberto de Andrade, E-mail: mcfragoso@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2015-07-01

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

  18. Basal and hyperaemic myocardial blood flow in regionally denervated canine hearts: an in vivo study with positron emission tomography

    Rimoldi, Ornella E.; Camici, Paolo G. [Hammersmith Hospital, MRC Clinical Sciences Centre, London (United Kingdom); Imperial College, National Heart and Lung Institute, London (United Kingdom); Drake-Holland, Angela J. [Robert Gordon University, School of Pharmacy, Aberdeen (United Kingdom); Noble, Mark I.M. [University of Aberdeen, Department of Cardiology, Aberdeen (United Kingdom)

    2007-02-15

    Positron emission tomography (PET) studies in patients with diabetic autonomic neuropathy (DAN) have demonstrated the impact of this disease on cardiac sympathetic innervation and myocardial blood flow (MBF). To investigate the effects of selective partial sympathetic denervation of the left ventricle (LV) on baseline and hyperaemic MBF, we measured myocardial presynaptic catecholamine re-uptake (uptake-1), {beta}-adrenoceptor ({beta}-AR) density and MBF non-invasively by means of PET in a canine model of regional sympathetic denervation. In 11 anaesthetised dogs, the sympathetic nerves of the free wall and septum of the LV were removed by means of dissection and phenol painting. Three weeks later, the animals were studied with PET. MBF was measured at baseline and following i.v. adenosine (140 {mu}g kg{sup -1} min{sup -1}) and dobutamine (20 {mu}g kg{sup -1} min{sup -1}) using{sup 15}O-labelled water. Sympathetic denervation was confirmed by an 80{+-}12% decrease in the volume of distribution (V{sub d}) of [{sup 11}C]hydroxyephedrine (HED) compared with innervated regions. Myocardial {beta}-AR density was measured using [{sup 11}C]CGP12177. Innervated and denervated regions showed no differences in MBF at baseline and during adenosine or dobutamine. [{sup 11}C]HED V{sub d}was inversely correlated with MBF in both regions at baseline, and the correlation was lost during hyperaemia in denervated regions. However, for any given value of MBF, [{sup 11}C]HED V{sub d}was significantly lower in the denervated regions. {beta}-AR density was comparable in denervated and innervated regions (17.9{+-}4.2 vs 18.4{+-}3.3 pmol g{sup -1};p=NS). In this experimental model, selective, regional sympathetic denervation of the LV, which results in a profound reduction in [{sup 11}C]HED V{sub d}, did not affect baseline or hyperaemic MBF. In addition, we demonstrated that, under baseline conditions, there was a significant inverse correlation between [{sup 11}C]HED V{sub d}and MBF in

  19. Accuracy and precision of pseudo-continuous arterial spin labeling perfusion during baseline and hypercapnia: a head-to-head comparison with ¹⁵O H₂O positron emission tomography.

    Heijtel, D F R; Mutsaerts, H J M M; Bakker, E; Schober, P; Stevens, M F; Petersen, E T; van Berckel, B N M; Majoie, C B L M; Booij, J; van Osch, M J P; Vanbavel, E; Boellaard, R; Lammertsma, A A; Nederveen, A J

    2014-05-15

    Measurements of the cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) provide useful information about cerebrovascular condition and regional metabolism. Pseudo-continuous arterial spin labeling (pCASL) is a promising non-invasive MRI technique to quantitatively measure the CBF, whereas additional hypercapnic pCASL measurements are currently showing great promise to quantitatively assess the CVR. However, the introduction of pCASL at a larger scale awaits further evaluation of the exact accuracy and precision compared to the gold standard. (15)O H₂O positron emission tomography (PET) is currently regarded as the most accurate and precise method to quantitatively measure both CBF and CVR, though it is one of the more invasive methods as well. In this study we therefore assessed the accuracy and precision of quantitative pCASL-based CBF and CVR measurements by performing a head-to-head comparison with (15)O H₂O PET, based on quantitative CBF measurements during baseline and hypercapnia. We demonstrate that pCASL CBF imaging is accurate during both baseline and hypercapnia with respect to (15)O H₂O PET with a comparable precision. These results pave the way for quantitative usage of pCASL MRI in both clinical and research settings.

  20. Study of the {sup 18}F(p,{alpha}){sup 15}O reaction by transfer reaction for application to {gamma}-ray emission from Novae; Etude de la reaction {sup 18}F(p,{alpha}){sup 15}O par reaction de transfert pour application a l'emission {gamma} des Novae

    Sereville, N. de

    2003-12-15

    The gamma emission from novae at/or below 511 keV is due to the annihilation of the positrons produced in the beta + decay of F{sup 18}. The interpretation of this emission through observations made by the Integral satellite for instance, requires a good knowledge of F{sup 18} nucleosynthesis. The reaction rate of the F{sup 18}(p,{alpha})O{sup 15} is the least known because of 2 resonances corresponding to the levels 6.419 and 6.449 MeV of Ne{sup 19} whose proton widths are completely unknown. We have determined these proton widths via the study of one-nucleon transfer reaction D(F{sup 18},p{alpha})N{sup 15} populating equivalent levels in F{sup 19}. We have used a 14 MeV F{sup 18} radioactive beam on a CD{sub 2} target for inverse kinematics studies and the multi-track silicon detector LEDA. A DWBA (Distorted Wave Bound Approximation) has enabled us to determine the proton width of both resonances and has showed that they have an impact in the calculation of the reaction rate. A thorough study of the remaining uncertainties of the reaction rate has been undertaken, particularly for those concerning interferences between these resonances and a higher resonance of Ne{sup 19}. The reaction rate that we have obtained is very similar to the previous rate used but now it rests on a more solid basis.

  1. Study of the production yields of {sup 18}F, {sup 11}C, {sup 13}N and {sup 15}O positron emitters from plasma-laser proton sources at ELI-Beamlines for labeling of PET radiopharmaceuticals

    Amato, Ernesto [Section of Radiological Sciences, Department of Biomedical and Dental Sciences and of Morphologic and Functional Imaging, University of Messina (Italy); Italiano, Antonio, E-mail: italianoa@unime.it [Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Messina (Italy); Margarone, Daniele [Institute of Physics ASCR, v.v.i. (FZU), ELI-Beamlines Project, 182 21 Prague (Czech Republic); Pagano, Benedetta [Nuclear Medicine Unit, University Hospital “G. Martino”, Messina (Italy); Baldari, Sergio [Section of Radiological Sciences, Department of Biomedical and Dental Sciences and of Morphologic and Functional Imaging, University of Messina (Italy); Nuclear Medicine Unit, University Hospital “G. Martino”, Messina (Italy); Korn, Georg [Institute of Physics ASCR, v.v.i. (FZU), ELI-Beamlines Project, 182 21 Prague (Czech Republic)

    2016-03-01

    The development of novel compact PET radionuclide production systems is of great interest to promote the diffusion of PET diagnostics, especially in view of the continuous development of microfluidics labeling approaches. We studied the feasibility to produce clinically-relevant amounts of PET isotopes by means of laser-accelerated proton sources such that expected at the ELI-Beamlines facility. {sup 18}F, {sup 11}C, {sup 13}N and {sup 15}O production yields were calculated through the TALYS software, by taking into account the broad proton spectra expected. With the hypothesized proton fluencies, clinically-relevant amounts of radionuclides can be obtained, suitable to prepare single doses of {sup 18}F-, {sup 11}C- and {sup 13}N-labeled radiopharmaceuticals exploiting fast and efficient microfluidic labeling systems.

  2. Sub-millimeter nuclear medical imaging with reduced dose application in positron emission tomography using beta-gamma coincidences

    Lang, C; Parodi, K; Thirolf, P G

    2013-01-01

    Positron emission tomography (PET) permits a functional understanding of the underlying causes of many diseases. Modern whole-body PET systems reach a spatial resolution of 2-6 mm (FWHM). A limitation of this technique occurs from the thermalization and diffusion of the positron before its annihilation, typically within the mm range. We present a nuclear medical imaging technique, able to reach sub-millimeter spatial resolution in 3 dimensions with a reduced effective dose application compared to conventional PET. This 'gamma-PET' technique draws on specific medical isotopes, simultaneously emitting an additional photon accompanying the beta^+ decay. Exploiting the triple coincidence between the positron annihilation and the third photon, it is possible to separate the reconstructed 'true' events from background. In order to characterize the potential of this technique, MC simulations and image reconstructions have been performed. The achievable spatial resolution has been found to reach ca. 0.4 mm (FWHM) in ...

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

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

    2015-12-15

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

  4. Determination of spatial resolution of positron emission tomograph of clear PET-XPAD3/CT system

    Olaya D, H.; Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, 150003 Tunja, Boyaca (Colombia); Morel, C. [Centre de Physique des Particules de Marseille, ImXgam Group, 13009 Marseille (France); Castro, H. F. [Universidad Nacional de Colombia, Physics Department, Carrera 45 No. 26-85, Bogota (Colombia)

    2016-10-15

    Based on the National Electrical Manufacturers Association (Nema), using the Amine software to construction of sinograms and using a radioactive source {sup 22}Na that emitting positrons were made calculations for determine spatial resolution of ring array system of phoswich detectors of positron emission tomograph included in the Clear PET-XPAD3/CT prototype for small animals made in the laboratories of CCPM and whose project is led by the research group ImXgam. The radioactive source {sup 22}Na approximately 9 MBq of activity, with spherical shape and diameter of 0.57 mm immersed in a plexiglas disc was located at the geometric center of tomographic system with a Field of View (Fov) of 35 mm in the axial and transverse directions. Displacements of radioactive source were performed on the three cartesian axes and was rebuilt a sinogram for each axis. The shape of sinogram allow describe the correct position and the maximum efficiency of each detector. Subsequently, was carried out a scanning in each one of three spatial axes taking an enough distance covering the dimensions of radioactive source, were recorded data for each one of phoswich detector crystals which are aligned in the axis of movement. The process was repeated for other axes and then was offsetting the radioactive source with respect to the Fov and were calculated FWHM (Full Width at Half Maximum) and FWTM (Full Width at Tenth Maximum) values and performing statistics of these values with parabolic fitting, the latter setting allows to obtain parameters of spatial resolution of system. (Author)

  5. Optimised motion tracking for positron emission tomography studies of brain function in awake rats.

    Andre Z Kyme

    Full Text Available Positron emission tomography (PET is a non-invasive molecular imaging technique using positron-emitting radioisotopes to study functional processes within the body. High resolution PET scanners designed for imaging rodents and non-human primates are now commonplace in preclinical research. Brain imaging in this context, with motion compensation, can potentially enhance the usefulness of PET by avoiding confounds due to anaesthetic drugs and enabling freely moving animals to be imaged during normal and evoked behaviours. Due to the frequent and rapid motion exhibited by alert, awake animals, optimal motion correction requires frequently sampled pose information and precise synchronisation of these data with events in the PET coincidence data stream. Motion measurements should also be as accurate as possible to avoid degrading the excellent spatial resolution provided by state-of-the-art scanners. Here we describe and validate methods for optimised motion tracking suited to the correction of motion in awake rats. A hardware based synchronisation approach is used to achieve temporal alignment of tracker and scanner data to within 10 ms. We explored the impact of motion tracker synchronisation error, pose sampling rate, rate of motion, and marker size on motion correction accuracy. With accurate synchronisation (20 Hz, and a small head marker suitable for awake animal studies, excellent motion correction results were obtained in phantom studies with a variety of continuous motion patterns, including realistic rat motion (<5% bias in mean concentration. Feasibility of the approach was also demonstrated in an awake rat study. We conclude that motion tracking parameters needed for effective motion correction in preclinical brain imaging of awake rats are achievable in the laboratory setting. This could broaden the scope of animal experiments currently possible with PET.

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

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

    2012-04-01

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

  7. An automatic classification technique for attenuation correction in positron emission tomography

    Bettinardi, V.; Pagani, E.; Gilardi, M.C.; Landoni, C.; Riddell, C.; Rizzo, G.; Castiglioni, I.; Belluzzo, D.; Lucignani, G.; Fazio, F. [INB-CNR, Scientific Inst. H San Raffaele, Univ. of Milan (Italy); Schubert, S. [GE Medical System, Milwaukee, WI (United States)

    1999-05-01

    In this paper a clustering technique is proposed for attenuation correction (AC) in positron emission tomography (PET). The method is unsupervised and adaptive with respect to counting statistics in the transmission (TR) images. The technique allows the classification of pre- or post-injection TR images into main tissue components in terms of attenuation coefficients. The classified TR images are then forward projected to generate new TR sinograms to be used for AC in the reconstruction of the corresponding emission (EM) data. The technique has been tested on phantoms and clinical data of brain, heart and whole-body PET studies. The method allows: (a) reduction of noise propagation from TR into EM images, (b) reduction of TR scanning to a few minutes (3 min) with maintenance of the quantitative accuracy (within 6%) of longer acquisition scans (15-20 min), (c) reduction of the radiation dose to the patient, (d) performance of quantitative whole-body studies. (orig.) With 8 figs., 4 tabs., 25 refs.

  8. Dependence of simulated positron emitter yields in ion beam cancer therapy on modeling nuclear fragmentation.

    Lühr, Armin; Priegnitz, Marlen; Fiedler, Fine; Sobolevsky, Nikolai; Bassler, Niels

    2014-01-01

    In ion beam cancer therapy, range verification in patients using positron emission tomography (PET) requires the comparison of measured with simulated positron emitter yields. We found that (1) changes in modeling nuclear interactions strongly affected the positron emitter yields and that (2) Monte Carlo simulations with SHIELD-HIT10Areasonably matched the most abundant PET isotopes (11)C and (15)O. We observed an ion-energy (i.e., depth) dependence of the agreement between SHIELD-HIT10Aand measurement. Improved modeling requires more accurate measurements of cross-section values.

  9. Fluorodeoxyglucose-positron emission tomography in carcinoma nasopharynx: Can we predict outcomes and tailor therapy based on postradiotherapy fluorodeoxyglucose-positron emission tomography?

    Sarbani Ghosh Laskar

    2016-01-01

    Full Text Available Background: Positron emission tomography-computed tomography (PET-CT is an emerging modality for staging and response evaluation in carcinoma nasopharynx. This study was conducted to evaluate the impact of PET-CT in assessing response and outcomes in carcinoma nasopharynx. Materials and Methods: Forty-five patients of nonmetastatic carcinoma nasopharynx who underwent PET-CT for response evaluation at 10-12 weeks posttherapy between 2004 and 2009 were evaluated. Patients were classified as responders (Group A if there was a complete response on PET-CT or as nonresponders (Group B if there was any uptake above the background activity. Data regarding demographics, treatment, and outcomes were collected from their records and compared across the Groups A and B. Results: The median age was 41 years. 42 out of 45 (93.3% patients had WHO Grade 2B disease (undifferentiated squamous carcinoma. 24.4%, 31.1%, 15.6, and 28.8% patients were in American Joint Committee on Cancer Stage IIb, III, Iva, and IVb. All patients were treated with neoadjuvant chemotherapy followed by concomitant chemoradiotherapy. Forty-five patients, 28 (62.2% were classified as responders, whereas 17 (37.8% were classified as nonresponders. There was no significant difference in the age, sex, WHO grade, and stage distribution between the groups. Compliance to treatment was comparable across both groups. The median follow-up was 25.3 months (759 days. The disease-free survival (DFS of the group was 57.3% at 3 years. The DFS at 3 years was 87.3% and 19.7% for Group A and B, respectively (log-rank test, P < 0.001. Univariate and multivariate analysis revealed Groups to be the only significant factor predicting DFS (P value 0.002 and < 0.001, respectively. In Group B, the most common site of disease failure was distant (9, 53%. Conclusion: PET-CT can be used to evaluate response and as a tool to identify patients at higher risk of distant failure. Further, this could be exploited to

  10. CO2BOLD assessment of moyamoya syndrome: Validation with single photon emission computed tomography and positron emission tomography imaging

    Pellaton, Alain; Bijlenga, Philippe; Bouchez, Laurie; Cuvinciuc, Victor; Barnaure, Isabelle; Garibotto, Valentina; Lövblad, Karl-Olof; Haller, Sven

    2016-01-01

    AIM To compare the assessment of cerebrovascular reserve (CVR) using CO2BOLD magnetic resonance imaging (MRI) vs positron emission tomography (PET) and single photon emission computed tomography (SPECT) as reference standard. METHODS Ten consecutive patients (8 women, mean age of 41 ± 26 years) with moyamoya syndrome underwent 14 pre-surgical evaluations for external-internal carotid artery bypass surgery. CVR was assessed using CO2BOLD and PET (4)/SPECT (11) with a maximum interval of 36 d, and evaluated by two experienced neuroradiologists. RESULTS The inter-rater agreement was 0.81 for SPECT (excellent), 0.43 for PET (fair) and 0.7 for CO2BOLD (good). In 9/14 cases, there was a correspondence between CO2BOLD and PET/SPECT. In 4/14 cases, CVR was over-estimated in CO2BOLD, while in 1/14 case, CVR was underestimated in CO2BOLD. The sensitivity of CO2BOLD was 86% and a specificity of 43%. CONCLUSION CO2BOLD can be used for pre-surgical assessment of CVR in patients with moyamoya syndrome and combines the advantages of absent irradiation, high availability of MRI and assessment of brain parenchyma, cerebral vessels and surrogate CVR in one stop. PMID:27928470

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

    Dooraghi, Alex Abreu

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

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

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

    2016-05-01

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

  13. Modeling clustered activity increase in amyloid-beta positron emission tomographic images with statistical descriptors

    Shokouhi S

    2015-04-01

    Full Text Available Sepideh Shokouhi,1 Baxter P Rogers,1 Hakmook Kang,2 Zhaohua Ding,1 Daniel O Claassen,3 John W Mckay,1 William R Riddle1On behalf of the Alzheimer’s Disease Neuroimaging Initiative1Department of Radiology and Radiological Sciences, Vanderbilt University Institute of Imaging Science, 2Department of Biostatistics, 3Department of Neurology, Vanderbilt University, Nashville, TN, USABackground: Amyloid-beta (Aβ imaging with positron emission tomography (PET holds promise for detecting the presence of Aβ plaques in the cortical gray matter. Many image analyses focus on regional average measurements of tracer activity distribution; however, considerable additional information is available in the images. Metrics that describe the statistical properties of images, such as the two-point correlation function (S2, have found wide applications in astronomy and materials science. S2 provides a detailed characterization of spatial patterns in images typically referred to as clustering or flocculence. The objective of this study was to translate the two-point correlation method into Aβ-PET of the human brain using 11C-Pittsburgh compound B (11C-PiB to characterize longitudinal changes in the tracer distribution that may reflect changes in Aβ plaque accumulation.Methods: We modified the conventional S2 metric, which is primarily used for binary images and formulated a weighted two-point correlation function (wS2 to describe nonbinary, real-valued PET images with a single statistical function. Using serial 11C-PiB scans, we calculated wS2 functions from two-dimensional PET images of different cortical regions as well as three-dimensional data from the whole brain. The area under the wS2 functions was calculated and compared with the mean/median of the standardized uptake value ratio (SUVR. For three-dimensional data, we compared the area under the wS2 curves with the subjects’ cerebrospinal fluid measures.Results: Overall, the longitudinal changes in wS2

  14. A novel image reconstruction methodology based on inverse Monte Carlo analysis for positron emission tomography

    Kudrolli, Haris A.

    2001-04-01

    A three dimensional (3D) reconstruction procedure for Positron Emission Tomography (PET) based on inverse Monte Carlo analysis is presented. PET is a medical imaging modality which employs a positron emitting radio-tracer to give functional images of an organ's metabolic activity. This makes PET an invaluable tool in the detection of cancer and for in-vivo biochemical measurements. There are a number of analytical and iterative algorithms for image reconstruction of PET data. Analytical algorithms are computationally fast, but the assumptions intrinsic in the line integral model limit their accuracy. Iterative algorithms can apply accurate models for reconstruction and give improvements in image quality, but at an increased computational cost. These algorithms require the explicit calculation of the system response matrix, which may not be easy to calculate. This matrix gives the probability that a photon emitted from a certain source element will be detected in a particular detector line of response. The ``Three Dimensional Stochastic Sampling'' (SS3D) procedure implements iterative algorithms in a manner that does not require the explicit calculation of the system response matrix. It uses Monte Carlo techniques to simulate the process of photon emission from a source distribution and interaction with the detector. This technique has the advantage of being able to model complex detector systems and also take into account the physics of gamma ray interaction within the source and detector systems, which leads to an accurate image estimate. A series of simulation studies was conducted to validate the method using the Maximum Likelihood - Expectation Maximization (ML-EM) algorithm. The accuracy of the reconstructed images was improved by using an algorithm that required a priori knowledge of the source distribution. Means to reduce the computational time for reconstruction were explored by using parallel processors and algorithms that had faster convergence rates

  15. Cerebral hypometabolism in progressive supranuclear palsy studied with positron emission tomography

    Foster, N.L.; Gilman, S.; Berent, S.; Morin, E.M.; Brown, M.B.; Koeppe, R.A.

    1988-09-01

    Progressive supranuclear palsy (PSP) is characterized by supranuclear palsy of gaze, axial dystonia, bradykinesia, rigidity, and a progressive dementia. Pathological changes in this disorder are generally restricted to subcortical structures, yet the type and range of cognitive deficits suggest the involvement of many cerebral regions. We examined the extent of functional impairment to cerebral cortical and subcortical structures as measured by the level of glucose metabolic activity at rest. Fourteen patients with PSP were compared to 21 normal volunteers of similar age using 18F-2-fluoro-2-deoxy-D-glucose and positron emission tomography. Glucose metabolism was reduced in the caudate nucleus, putamen, thalamus, pons, and cerebral cortex, but not in the cerebellum in the patients with PSP as compared to the normal subjects. Analysis of individual brain regions revealed significant declines in cerebral glucose utilization in most regions throughout the cerebral cortex, particularly those in the superior half of the frontal lobe. Declines in the most affected regions of cerebral cortex were greater than those in any single subcortical structure. Although using conventional neuropathological techniques the cerebral cortex appears to be unaffected in PSP, significant and pervasive functional impairments in both cortical and subcortical structures are present. These observations help to account for the constellation of cognitive symptoms in individual patients with PSP and the difficulty encountered in identifying a characteristic psychometric profile for this group of patients.

  16. Radiolabelled molecules for imaging the translocator protein (18 kDa) using positron emission tomography

    Dolle, F.; Luus, C.; Reynolds, A.; Kassiou, M. [CEA, Institut d' Imagerie BioMedicale, Service Hospitalier Frederic Joliot, Orsay (France)

    2009-07-01

    The translocator protein (18 kDa) (TSPO), formerly known as the peripheral benzodiazepine receptor (PBR), was originally identified as an alternate binding site for the central benzodiazepine receptor (CBR) ligand, diazepam, in the periphery, but has now been distinguished as a novel site. The TSPO is ubiquitously expressed in peripheral tissues but only minimally in the healthy brain and increased levels of TSPO expression have been noted in neuro inflammatory conditions such as Alzheimer's disease, Parkinson's disease and stroke. This increase in TSPO expression has been reported to coincide with the process of micro-glial activation, whereby the brain's intrinsic immune system becomes active. Therefore, by using recently developed high affinity, selective TSPO ligands in conjunction with functional imaging modalities such as positron emission tomography (PET), it becomes possible to study the process of micro-glial activation in the living brain. A number of high affinity ligands, the majority of which are C, N-substituted acetamide derivatives, have been successfully radiolabelled and used in in vivo studies of the TSPO and the process of micro-glial activation. This review highlights recent achievements (up to December 2008) in the field of functional imaging of the TSPO as well as the radio-syntheses involved in such studies. (authors)

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

    Charlotte D'Hulst

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

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

    Gerlinde Egerer

    2009-07-01

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

  19. Positron emission tomography / computerized tomography evaluation of primary Hodgkin's disease of liver.

    Gota, V S; Purandare, N C; Gujral, S; Shah, S; Nair, R; Rangarajan, V

    2009-01-01

    Occurrence of primary Hodgkin's lymphoma (PHL) of the liver is extremely rare. We report on a case of a 60-year-old male who presented with liver mass and B-symptomatology. Hepatoma or hepatic metastasis from a gastrointestinal primary was initially suspected. Tumor markers like AFP, CEA, Total PSA, and CA-19.9 were within normal limits. Positron Emission Tomography / Computerized Tomography (PET/CT) revealed a large hepatic lesion and a nodal mass in the porta hepatis. A liver biopsy was consistent with Hodgkin's lymphoma. There was complete regression of the hepatic lesion and evidence of shrinkage of the nodal mass following four cycles of chemotherapy. 18F Fluro -de-oxy Glucose (FDG) PET / CT in this case helped in establishing a primary hepatic lymphoma by demonstrating the absence of pathologically hypermetabolic foci in any other nodes or organs. PET / CT scan is a useful adjunct to conventional imaging and histopathology, not only to establish the initial diagnosis, but also to monitor treatment response in PHL.

  20. Low background high efficiency radiocesium detection system based on positron emission tomography technology

    Yamamoto, Seiichi; Ogata, Yoshimune [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673 (Japan)

    2013-09-15

    After the 2011 nuclear power plant accident at Fukushima, radiocesium contamination in food became a serious concern in Japan. However, low background and high efficiency radiocesium detectors are expensive and huge, including semiconductor germanium detectors. To solve this problem, we developed a radiocesium detector by employing positron emission tomography (PET) technology. Because {sup 134}Cs emits two gamma photons (795 and 605 keV) within 5 ps, they can selectively be measured with coincidence. Such major environmental gamma photons as {sup 40}K (1.46 MeV) are single photon emitters and a coincidence measurement reduces the detection limit of radiocesium detectors. We arranged eight sets of Bi{sub 4}Ge{sub 3}O{sub 12} (BGO) scintillation detectors in double rings (four for each ring) and measured the coincidence between these detectors using PET data acquisition system. A 50 × 50 × 30 mm BGO was optically coupled to a 2 in. square photomultiplier tube (PMT). By measuring the coincidence, we eliminated most single gamma photons from the energy distribution and only detected those from {sup 134}Cs at an average efficiency of 12%. The minimum detectable concentration of the system for the 100 s acquisition time is less than half of the food monitor requirements in Japan (25 Bq/kg). These results show that the developed radiocesium detector based on PET technology is promising to detect low level radiocesium.

  1. Modelling Random Coincidences in Positron Emission Tomography by Using Singles and Prompts: A Comparison Study

    2016-01-01

    Random coincidences degrade the image in Positron Emission Tomography, PET. To compensate for their degradation effects, the rate of random coincidences should be estimated. Under certain circumstances, current estimation methods fail to provide accurate results. We propose a novel method, “Singles–Prompts” (SP), that includes the information conveyed by prompt coincidences and models the pile–up. The SP method has the same structure than the well-known “Singles Rate” (SR) approach. Hence, SP can straightforwardly replace SR. In this work, the SP method has been extensively assessed and compared to two conventional methods, SR and the delayed window (DW) method, in a preclinical PET scenario using Monte–Carlo simulations. SP offers accurate estimates for the randoms rates, while SR and DW tend to overestimate the rates (∼10%, and 5%, respectively). With pile-up, the SP method is more robust than SR (but less than DW). At the image level, the contrast is overestimated in SR-corrected images, +16%, while SP produces the correct value. Spill–over is slightly reduced using SP instead of SR. The DW images values are similar to those of SP except for low-statistic scenarios, where DW behaves as if randoms were not compensated for. In particular, the contrast is reduced, −16%. In general, the better estimations of SP translate into better image quality. PMID:27603143

  2. Photo-detectors for time of flight positron emission tomography (ToF-PET).

    Spanoudaki, Virginia Ch; Levin, Craig S

    2010-01-01

    We present the most recent advances in photo-detector design employed in time of flight positron emission tomography (ToF-PET). PET is a molecular imaging modality that collects pairs of coincident (temporally correlated) annihilation photons emitted from the patient body. The annihilation photon detector typically comprises a scintillation crystal coupled to a fast photo-detector. ToF information provides better localization of the annihilation event along the line formed by each detector pair, resulting in an overall improvement in signal to noise ratio (SNR) of the reconstructed image. Apart from the demand for high luminosity and fast decay time of the scintillation crystal, proper design and selection of the photo-detector and methods for arrival time pick-off are a prerequisite for achieving excellent time resolution required for ToF-PET. We review the two types of photo-detectors used in ToF-PET: photomultiplier tubes (PMTs) and silicon photo-multipliers (SiPMs) with a special focus on SiPMs.

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

    Craig S. Levin

    2010-11-01

    Full Text Available We present the most recent advances in photo-detector design employed in time of flight positron emission tomography (ToF-PET. PET is a molecular imaging modality that collects pairs of coincident (temporally correlated annihilation photons emitted from the patient body. The annihilation photon detector typically comprises a scintillation crystal coupled to a fast photo-detector. ToF information provides better localization of the annihilation event along the line formed by each detector pair, resulting in an overall improvement in signal to noise ratio (SNR of the reconstructed image. Apart from the demand for high luminosity and fast decay time of the scintillation crystal, proper design and selection of the photo-detector and methods for arrival time pick-off are a prerequisite for achieving excellent time resolution required for ToF-PET. We review the two types of photo-detectors used in ToF-PET: photomultiplier tubes (PMTs and silicon photo-multipliers (SiPMs with a special focus on SiPMs.

  4. A new mechanism of ionizing radiation detection for positron emission tomography: modulation of optical properties

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2016-10-01

    Using conventional scintillation detection, the fundamental limit in positron emission tomography (PET) annihilation photon pair coincidence time resolution is strongly dependent on the inherent temporal variances generated during the scintillation process, yielding an intrinsic physical limit of around 100 ps. On the other hand, modulation mechanisms of a material's optical properties as exploited in the optical telecommunications industry can be orders of magnitude faster. In this paper we borrow from the concept of optics pump-probe measurement to study whether ionizing radiation can also produce fast modulations of optical properties, which can be utilized as a novel method for radiation detection. We show that a refractive index modulation of approximately 5x10-6 is induced by interactions in a cadmium telluride (CdTe) crystal from a 511 keV photon source. Furthermore, using additional radionuclide sources, we show that the amplitude of the optical modulation signal varies linearly with both the radiation source flux rate and average photon energy.

  5. Dynamic positron emission tomography image restoration via a kinetics-induced bilateral filter.

    Zhaoying Bian

    Full Text Available Dynamic positron emission tomography (PET imaging is a powerful tool that provides useful quantitative information on physiological and biochemical processes. However, low signal-to-noise ratio in short dynamic frames makes accurate kinetic parameter estimation from noisy voxel-wise time activity curves (TAC a challenging task. To address this problem, several spatial filters have been investigated to reduce the noise of each frame with noticeable gains. These filters include the Gaussian filter, bilateral filter, and wavelet-based filter. These filters usually consider only the local properties of each frame without exploring potential kinetic information from entire frames. Thus, in this work, to improve PET parametric imaging accuracy, we present a kinetics-induced bilateral filter (KIBF to reduce the noise of dynamic image frames by incorporating the similarity between the voxel-wise TACs using the framework of bilateral filter. The aim of the proposed KIBF algorithm is to reduce the noise in homogeneous areas while preserving the distinct kinetics of regions of interest. Experimental results on digital brain phantom and in vivo rat study with typical (18F-FDG kinetics have shown that the present KIBF algorithm can achieve notable gains over other existing algorithms in terms of quantitative accuracy measures and visual inspection.

  6. The role of positron emission tomography in the detection of pancreatic disease

    Syrota, A.; Duquesnoy, N.; Paraf, A.; Kellershohn, C.

    1982-04-01

    Positron emission tomography (PET) was used to assess possible pancreatic disease in 100 patients. Following injection of 10-15 mCi (370-740 MBq) of /sup 11/C-L-methionine, 4-12 transverse sections 2 cm thick were obtained. In 85 patients with a definite diagnosis (45 normal, 9 acute pancreatitis, 18 chronic pancreatitis, and 13 cancer), PET showed a sensitivity of 85.0%, a specificity of 97.8%, and an accuracy of 91.8%, higher than with transmission computed tomography (CT) or ultrasonography, despite relatively low spatial resolution; this can be explained by the fact that exocrine pancreatic function was altered prior to morphological change. In 22 normal subjects, 0.011 +/- 0.003% (mean +/- S.D.) of injected /sup 11/C was found in 1 ml of liver tissue and 0.015 +/- 0.005% in 1 ml of pancreatic tissue; the pancreas-to-liver concentration ratio was 1.3 +/- 0.4. Hepatic /sup 11/C concentration was identical in the four groups of patients. Pancreatic uptake of /sup 11/C-L-methionine was significantly lower in patients with chronic pancreatitis (n = 13) and pancreatic carcinoma (n = 10) (p <0.001); however, it was not possible to distinguish cancer from chronic pancreatitis because the same functional alteration occurred in both.

  7. The role of positron emission tomography in the detection of pancreatic disease

    Syrota, A.; Duquesnoy, N.; Paraf, A.; Kellershohn, C.

    1982-04-01

    Positron emission tomography (PET) was used to assess possible pancreatic disease in 100 patients. Following injection of 10-15 mCi (370-740 MBq) of 11C-L-methionine, 4-12 transverse sections 2 cm thick were obtained. In 85 patients with a definite diagnosis (45 normal, 9 acute pancreatitis, 18 chronic pancreatitis, and 13 cancer), PET showed a sensitivity of 85.0%, a specificity of 97.8%, and an accuracy of 91.8%, higher than with transmission computed tomography (CT) or ultrasonography, despite relatively low spatial resolution; this can be explained by the fact that exocrine pancreatic function was altered prior to morphological change. In 22 normal subjects, 0.011 +/- 0.003% (mean +/- S.D). of injected 11C was found in 1 ml of liver tissue and 0.015 +/- 0.005% in 1 ml of pancreatic tissue; the pancreas-to-liver concentration ratio was 1.3 +/- 0.4. Hepatic 11C concentration was identical in the four groups of patients. Pancreatic uptake of 11C-L-methionine was significantly lower in patients with chronic pancreatitis (n . 13) and pancreatic carcinoma (n . 10) (p less than 0.001); however, it was not possible to distinguish cancer from chronic pancreatitis because the same functional alteration occurred in both.

  8. Small-Animal Imaging Using Clinical Positron Emission Tomography/Computed Tomography and Super-Resolution

    Frank P. DiFilippo

    2012-05-01

    Full Text Available Considering the high cost of dedicated small-animal positron emission tomography/computed tomography (PET/CT, an acceptable alternative in many situations might be clinical PET/CT. However, spatial resolution and image quality are of concern. The utility of clinical PET/CT for small-animal research and image quality improvements from super-resolution (spatial subsampling were investigated. National Electrical Manufacturers Association (NEMA NU 4 phantom and mouse data were acquired with a clinical PET/CT scanner, as both conventional static and stepped scans. Static scans were reconstructed with and without point spread function (PSF modeling. Stepped images were postprocessed with iterative deconvolution to produce super-resolution images. Image quality was markedly improved using the super-resolution technique, avoiding certain artifacts produced by PSF modeling. The 2 mm rod of the NU 4 phantom was visualized with high contrast, and the major structures of the mouse were well resolved. Although not a perfect substitute for a state-of-the-art small-animal PET/CT scanner, a clinical PET/CT scanner with super-resolution produces acceptable small-animal image quality for many preclinical research studies.

  9. Monitoring of patients treated with particle therapy using positron-emission-tomography (PET: the MIRANDA study

    Combs Stephanie E

    2012-04-01

    Full Text Available Abstract Background The purpose of this clinical study is to investigate the clinical feasibility and effectiveness of offline Positron-Emission-Tomography (PET quality assurance for promoting the accuracy of proton and carbon ion beam therapy. Methods/Design A total of 240 patients will be recruited, evenly sampled among different analysis groups including tumors of the brain, skull base, head and neck region, upper gastrointestinal tract including the liver, lower gastrointestinal tract, prostate and pelvic region. From the comparison of the measured activity with the planned dose and its corresponding simulated activity distribution, conclusions on the delivered treatment will be inferred and, in case of significant deviations, correction strategies will be elaborated. Discussion The investigated patients are expected to benefit from this study, since in case of detected deviations between planned and actual treatment delivery a proper intervention (e.g., correction could be performed in a subsequent irradiation fraction. In this way, an overall better treatment could be achieved than without any in-vivo verification. Moreover, site-specific patient-population information on the precision of the ion range at HIT might enable improvement of the CT-range calibration curve as well as safe reduction of the treatment margins to promote enhanced treatment plan conformality and dose escalation for full clinical exploitation of the promises of ion beam therapy. Trial Registration NCT01528670

  10. The value of positron emission tomography in patients with non-small cell lung cancer

    Kee, Frank [Centre for Public Health, Queen' s University Belfast, Mulhouse Building, Royal Victoria Hospital Site, Grosvenor Road, Belfast BT12 6BJ, Northern Ireland (United Kingdom)], E-mail: f.kee@qub.ac.uk; Erridge, Sara [Edinburgh Cancer Centre, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XU, Scotland (United Kingdom); Bradbury, Ian [Frontier Science (Scotland) Ltd., Grampian View, Kincraig, Inverness-shire PH21 1NA, Scotland (United Kingdom); Cairns, Karen [School of Maths and Physics, Queen' s University Belfast, David Bates Building, University Road, Belfast BT7 1NN, Northern Ireland (United Kingdom)

    2010-01-15

    Background: Pre-operative assessment of non-small cell lung cancer (NSCLC) is a major application of positron emission tomography (FDG-PET). Despite substantial evidence of diagnostic accuracy, relatively little attention has been paid to its effects on patient outcomes. This paper addresses this by extending an existing decision model to include patient-elicited utilities. Patients and methods: A decision-tree model of the effect of FDG-PET on pre-operative staging was converted to a Markov model. Utilities for futile and appropriate thoracotomy were elicited from 75 patients undergoing staging investigation for NSCLC. The decision model was then used to estimate the expected value of perfect information (EVPI) associated with three sources of uncertainty-the accuracy of PET, the accuracy of CT and the patient related utility of a futile thoracotomy. Results: The model confirmed the apparent cost-effectiveness of FDG-PET and indicated that the EVPI associated with the utility of futile thoracotomy considerably exceeds that associated with measures of accuracy. Conclusion: The study highlights the importance of patient related utilities in assessing the cost-effectiveness of diagnostic technologies. In the specific case of PET for pre-operative staging of NSCLC, future research effort should focus on such elicitation, rather than further refinement of accuracy estimates.

  11. Virtual positron emission tomography/computed tomography-bronchoscopy: possibilities, advantages and limitations of clinical application

    Seemann, Marcus D. [University of Magdeburg, Department of Radiology and Nuclear Medicine, Magdeburg (Germany); Schaefer, Juergen F. [Eberhard-Karls University, Department of Diagnostic Radiology, Tuebingen (Germany); Englmeier, Karl-Hans [Institute of Medical Informatics, GSF-National Research Center for Environment and Health, Neuherberg (Germany)

    2007-03-15

    The aim of this study was to demonstrate the possibilities, advantages and limitations of virtual bronchoscopy using data sets from positron emission tomography (PET) and computed tomography (CT). Twelve consecutive patients with lung cancer underwent PET/CT. PET was performed with F-18-labelled 2-[fluorine-18]-fluoro-2-deoxy-D-glucose ({sup 18}F-FDG). The tracheobronchial system was segmented with a volume-growing algorithm, using the CT data sets, and visualized with a shaded-surface rendering method. The primary tumours and the lymph node metastases were segmented for virtual CT-bronchoscopy using the CT data set and for virtual PET/CT-bronchoscopy using the PET/CT data set. Virtual CT-bronchoscopy using the low-dose or diagnostic CT facilitates the detection of anatomical/morphological structure changes of the tracheobronchial system. Virtual PET/CT-bronchoscopy was superior to virtual CT-bronchoscopy in the detection of lymph node metastases (P=0.001), because it uses the CT information and the molecular/metabolic information from PET. Virtual PET/CT-bronchoscopy with a transparent colour-coded shaded-surface rendering model is expected to improve the diagnostic accuracy of identification and characterization of malignancies, assessment of tumour staging, differentiation of viable tumour tissue from atelectases and scars, verification of infections, evaluation of therapeutic response and detection of an early stage of recurrence that is not detectable or is misjudged in comparison with virtual CT-bronchoscopy. (orig.)

  12. INSIDE in-beam positron emission tomography system for particle range monitoring in hadrontherapy.

    Bisogni, Maria Giuseppina; Attili, Andrea; Battistoni, Giuseppe; Belcari, Nicola; Camarlinghi, Niccolo'; Cerello, Piergiorgio; Coli, Silvia; Del Guerra, Alberto; Ferrari, Alfredo; Ferrero, Veronica; Fiorina, Elisa; Giraudo, Giuseppe; Kostara, Eleftheria; Morrocchi, Matteo; Pennazio, Francesco; Peroni, Cristiana; Piliero, Maria Antonietta; Pirrone, Giovanni; Rivetti, Angelo; Rolo, Manuel D; Rosso, Valeria; Sala, Paola; Sportelli, Giancarlo; Wheadon, Richard

    2017-01-01

    The quality assurance of particle therapy treatment is a fundamental issue that can be addressed by developing reliable monitoring techniques and indicators of the treatment plan correctness. Among the available imaging techniques, positron emission tomography (PET) has long been investigated and then clinically applied to proton and carbon beams. In 2013, the Innovative Solutions for Dosimetry in Hadrontherapy (INSIDE) collaboration proposed an innovative bimodal imaging concept that combines an in-beam PET scanner with a tracking system for charged particle imaging. This paper presents the general architecture of the INSIDE project but focuses on the in-beam PET scanner that has been designed to reconstruct the particles range with millimetric resolution within a fraction of the dose delivered in a treatment of head and neck tumors. The in-beam PET scanner has been recently installed at the Italian National Center of Oncologic Hadrontherapy (CNAO) in Pavia, Italy, and the commissioning phase has just started. The results of the first beam test with clinical proton beams on phantoms clearly show the capability of the in-beam PET to operate during the irradiation delivery and to reconstruct on-line the beam-induced activity map. The accuracy in the activity distal fall-off determination is millimetric for therapeutic doses.

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

    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.

  14. Neural correlates of sensorimotor gating: A metabolic positron emission tomography study in awake rats

    Cathrin eRohleder

    2014-05-01

    Full Text Available Impaired sensorimotor gating occurs in neuropsychiatric disorders such as schizophrenia and can be measured using the prepulse inhibition (PPI paradigm of the acoustic startle response. This assay is frequently used to validate animal models of neuropsychiatric disorders and to explore the therapeutic potential of new drugs. The underlying neural network of PPI has been extensively studied with invasive methods and genetic modifications. However, its relevance for healthy untreated animals and the functional interplay between startle- and PPI-related areas during a PPI session is so far unknown. Therefore, we studied awake rats in a PPI paradigm, startle control and background noise control, combined with behavioral [18F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET. Subtractive analyses between conditions were used to identify brain regions involved in startle and PPI processing in well-hearing Black hooded rats. For correlative analysis with regard to the amount of PPI we also included hearing-impaired Lister hooded rats that startled more often, because their hearing threshold was just below the lowest prepulses. Metabolic imaging showed that the brain areas proposed for startle and PPI mediation are active during PPI paradigms in healthy untreated rats. More importantly, we show for the first time that the whole PPI modulation network is active during passive PPI sessions, where no selective attention to prepulse or startle stimulus is required. We conclude that this reflects ongoing monitoring of stimulus significance and constant adjustment of sensorimotor gating.

  15. Application of 18F-fluorodeoxyglucose Positron Emission Tomography in Diagnosis of Malignant Diseases

    Xiao-hong Ning; Qiu-li Meng; Yu-zhou Wang; Chun-mei Bai

    2009-01-01

    To testify the efficacy of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomo-graphy (PET) in the diagnosis of cancer.Methods A total of 170 patients with diagnosed cancer or suspicious cancer were enrolled in this study, and underwent 18F-FDG PET. The standard uptake value (SUV) and diameter for each abnormal region in PET images were analyzed. All data were analyzed by SPSS 11.5.Results PET scan identified a primary cancer in 45.8% (11/24) patients. The sensitivity and specificity of PET scan in differentiating malignant lesions from benign ones were 78.8% (52/66) and 77.1% (27/35) respectively. Twenty-nine out of 68 (42.6%) lesions were detected earlier by PET than by computed tomography. The SUV of primary cancer was significantly higher than that of metastatic lymph nodes (5.84±3.12 vs. 3.14±2.24, P<0.O01). And SUV of primary lung cancer was also significantly higher than that of metastatic lung cancer (6.30±3.01 vs. 2.86±2.37, P<0.01).Conclusion 18F-FDG PET plays a very important role in cancer diagnosis.

  16. Preclinical positron emission tomography scanner based on a monolithic annulus of scintillator: initial design study.

    Stolin, Alexander V; Martone, Peter F; Jaliparthi, Gangadhar; Raylman, Raymond R

    2017-01-01

    Positron emission tomography (PET) scanners designed for imaging of small animals have transformed translational research by reducing the necessity to invasively monitor physiology and disease progression. Virtually all of these scanners are based on the use of pixelated detector modules arranged in rings. This design, while generally successful, has some limitations. Specifically, use of discrete detector modules to construct PET scanners reduces detection sensitivity and can introduce artifacts in reconstructed images, requiring the use of correction methods. To address these challenges, and facilitate measurement of photon depth-of-interaction in the detector, we investigated a small animal PET scanner (called AnnPET) based on a monolithic annulus of scintillator. The scanner was created by placing 12 flat facets around the outer surface of the scintillator to accommodate placement of silicon photomultiplier arrays. Its performance characteristics were explored using Monte Carlo simulations and sections of the NEMA NU4-2008 protocol. Results from this study revealed that AnnPET's reconstructed spatial resolution is predicted to be [Formula: see text] full width at half maximum in the radial, tangential, and axial directions. Peak detection sensitivity is predicted to be 10.1%. Images of simulated phantoms (mini-hot rod and mouse whole body) yielded promising results, indicating the potential of this system for enhancing PET imaging of small animals.

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

    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.

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

    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.

  19. Effect of Harderian adenectomy on the statistical analyses of mouse brain imaging using positron emission tomography.

    Kim, Minsoo; Woo, Sang-Keun; Yu, Jung Woo; Lee, Yong Jin; Kim, Kyeong Min; Kang, Joo Hyun; Eom, Kidong; Nahm, Sang-Soep

    2014-01-01

    Positron emission tomography (PET) using 2-deoxy-2-[(18)F] fluoro-D-glucose (FDG) as a radioactive tracer is a useful technique for in vivo brain imaging. However, the anatomical and physiological features of the Harderian gland limit the use of FDG-PET imaging in the mouse brain. The gland shows strong FDG uptake, which in turn results in distorted PET images of the frontal brain region. The purpose of this study was to determine if a simple surgical procedure to remove the Harderian gland prior to PET imaging of mouse brains could reduce or eliminate FDG uptake. Measurement of FDG uptake in unilaterally adenectomized mice showed that the radioactive signal emitted from the intact Harderian gland distorts frontal brain region images. Spatial parametric measurement analysis demonstrated that the presence of the Harderian gland could prevent accurate assessment of brain PET imaging. Bilateral Harderian adenectomy efficiently eliminated unwanted radioactive signal spillover into the frontal brain region beginning on postoperative Day 10. Harderian adenectomy did not cause any post-operative complications during the experimental period. These findings demonstrate the benefits of performing a Harderian adenectomy prior to PET imaging of mouse brains.

  20. Molecular imaging of neuroinflammation in preclinical rodent models using positron emission tomography.

    Gargiulo, Sara; Coda, Anna R; Panico, Mariarosaria; Gramanzini, Matteo; Moresco, Rosa M; Chalon, Sylvie; Pappatà, Sabina

    2017-03-01

    Neuroinflammation (NI) is an adaptive response to different noxious stimuli, involving microglia, astrocytes and peripheral immune cells. NI is a hallmark of several acute and chronic diseases of central nervous system (CNS) and contributes to both damage and repair of CNS tissue. Interventional or genetically modified rodent models mimicking human neuropathologies may provide valuable insights on basic mechanisms of NI, but also for improving the development of new diagnostic and therapeutic strategies. Preclinical positron emission tomography (PET) allows to investigate noninvasively the inflammatory response in CNS of rodent models at a molecular level, validating innovative probes for early diagnosis, and characterizing the time course of neuroinflammatory changes and their relationship with disease progression, as well as the effects of experimental treatments with high translational potential. In particular, recent efforts of preclinical PET field are intended to develop specific and selective radiotracers that target the activation of innate immune system in CNS. Here, we have reviewed the state of art for PET in relevant rodent models of acute and chronic neuropathologies associated with NI, with particular regard on imaging of activated microglia and astrocytes.

  1. Positron emission tomography/computer tomography in guidance of extrahepatic hepatocellular carcinoma metastasis management

    2007-01-01

    Hepatocellular carcinoma (HCC) is one of the most common primary cancers in the world. Surgery is the gold standard for treatment of patients with HCC. Recurrence and metastasis are the major obstacles to further improve the prognosis of HCC. Most recurrences are intrahepatic. However, 30% of the recurrences are extrahepatic. The role of resection in intrahepatic recurrences is widely accepted. The role of resection in extrahepatic HCC recurrence and metastasis is not well established. 18F fluorodeoxyglucose (18F-FDG) positron emission tomography/computer tomography (PET/CT) is useful in detecting distant metastasis from a variety of malignancies and shows superior accuracy to conventional imaging modalities in identification of intrahepatic and extrahepatic metastasis. We present one patient with one new isolated omental lymph node metastasis, who had a history of huge HCC resected six years ago. The metastatic focus was identified with 18 F-FDG PET/CT and resected. The follow-up revealed good prognosis with a long-term survival potential after resection of the omental lymphatic metastasis.

  2. Metabolizer in vivo of fullerenes and metallofullerenes by positron emission tomography

    Li, Juan; Yang, Wenjiang; Cui, Rongli; Wang, Dongliang; Chang, Yanan; Gu, Weihong; Yin, Wenyan; Bai, Xue; Chen, Kui; Xia, Lin; Geng, Huan; Xing, Gengmei

    2016-04-01

    Fullerenes (C60) and metallofullerenes (Gd@C82) have similar chemical structure, but the bio-effects of both fullerene-based materials are distinct in vivo. Tracking organic carbon-based materials such as C60 and Gd@C82 is difficult in vivo due to the high content of carbon element in the living tissues themselves. In this study, the biodistribution and metabolism of fullerenes (C60 and Gd@C82) radiolabeled with 64Cu were observed by positron emission tomography (PET). 64Cu-C60 and 64Cu-Gd@C82 were prepared using 1, 4, 7, 10-tetrakis (carbamoylmethyl)-1, 4, 7, 10-tetra-azacyclodo-decanes grafted on carbon cages as a chelator for 64Cu, and were obtained rapidly with high radiochemical yield (≥90%). The new radio-conjugates were evaluated in vivo in the normal mouse model and tissue distribution by small animal PET/CT imaging and histology was carried out. The PET imaging, the biodistribution and the excretion of C60 and Gd@C82 indicated that C60 samples have higher blood retention and lower renal clearance than the Gd@C82 samples in vivo and suggested that the differences in metabolism and distribution in vivo were caused by the structural differences of the groups on the fullerene cages though there is chemical similarity between C60 and Gd@C82.

  3. Positron Emission Tomography Reveals Abnormal Topological Organization in Functional Brain Network in Diabetic Patients

    Qiu eXiangzhe

    2016-05-01

    Full Text Available Recent studies have demonstrated alterations in the topological organization of structural brain networks in diabetes mellitus (DM. However, the DM-related changes in the topological properties in functional brain networks are almost unexplored so far. We therefore used fluoro-D-glucose positron emission tomography (FDG-PET data to construct functional brain networks of 73 DM patients and 91 sex- and age-matched normal controls (NCs, followed by a graph theoretical analysis. We found that both DM patients and NCs had a small-world topology in functional brain network. In comparison to the NC group, the DM group was found to have significantly lower small-world index, lower normalized clustering coefficients and higher normalized shortest path length. Moreover, for diabetic patients, the nodal centrality was significantly reduced in the right rectus, the right cuneus, the left middle occipital gyrus, and the left postcentral gyrus, and it was significantly increased in the orbitofrontal region of the left middle frontal gyrus, the left olfactory region, and the right paracentral lobule. Our results demonstrated that the diabetic brain was associated with disrupted topological organization in the functional PET network, thus providing the functional evidence for the abnormalities of brain networks in DM.

  4. Development of analog solid-state photo-detectors for Positron Emission Tomography

    Bisogni, Maria Giuseppina, E-mail: giuseppina.bisogni@pi.infn.it; Morrocchi, Matteo

    2016-02-11

    Solid-state photo-detectors are one of the main innovations of past century in the field of sensors. First produced in the early forties with the invention of the p–n junction in silicon and the study of its optical properties, photo-detectors received a major boost in the sixties when the p-i-n (PIN) photodiode was developed and successfully used in several applications. The development of devices with internal gain, avalanche photodiodes (APD) first and then Geiger-mode avalanche photodiodes, named single photon avalanche diode (SPAD), leads to a substantial improvement in sensitivity and allowed single photon detection. Later on, thousands of SPADs have been assembled in arrays of few millimeters squared (named SiPM, silicon photo-multiplier) with single photon resolution. The high internal gain of SiPMs, together with other features peculiar of the silicon technology like compactness, speed and compatibility with magnetic fields, promoted SiPMs as the principal photo-detector competitor of photomultipliers in many applications from radiation detection to medical imaging. This paper provides a review of the properties of analog solid-state photo-detectors. Particular emphasis is given to latest advances on Positron Emission Tomography instrumentation boosted by the adoption of the silicon photo-detectors as an alternative to photomultiplier tubes (PMTs). Special attention is dedicated to the SiPMs, which are playing a key role in the development of innovative scanners.

  5. Optimized separation procedure for production of no-carrier-added radiomanganese for positron emission tomography

    Buchholz, Martin; Spahn, Ingo; Coenen, Heinz H. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Neurowissenschaften und Medizin (INM), Nuklearchemie (INM-5)

    2015-07-01

    The {sup nat}Cr(p,xn)-process is a very efficient route for production of {sup 52g}Mn(T{sub 1/2} = 5.59 d). Based on measurements of distribution coefficients with different media and ion-exchange resins, an optimized chromatographic separation of radiomanganese from {sup nat}Cr with the resin Amberlite CG400 was developed. With this system {sup nat}Cr is eluted first with an acetic acid/methanol 1:1 mixture at room temperature and {sup 52g}Mn thereafter with 3 M HCl at 50 C. Within a separation time of 4 h the method yielded 99.5% of the n.c.a. {sup 52g}Mn in 2-3 mL of 3 M HCl. An ICP-MS analysis revealed a chromium impurity of 0.07 mg (0.014%) in the n.c.a. {sup 52g}Mn solution, making this separation method suitable for the production of {sup 52g}Mn for medical applications like positron emission tomography (PET).

  6. A behavioral and micro positron emission tomography imaging study in a rat model of hypothyroidism.

    Yu, Jing; Tang, Yi-Yuang; Feng, Hong-Bo; Cheng, Xiao-Xin

    2014-09-01

    Hypothyroidism leads to somatic, neuropsychological, and psychiatric changes that are similar to depression. The mechanisms underlying the behavioral abnormalities in adult onset hypothyroidism remain ambiguous. Hypothyroidism was induced in adult male Wistar rats by the maintenance of 0.05% propylthiouracil (PTU) in drinking water for 5 weeks (hypothyroid group; HP group); control rats (CON group) received an equivalent amount of water. The open field and sucrose preference tests were employed, and the link between behavioral changes and brain glucose metabolism was evaluated using micro positron emission tomography imaging. The open field test revealed slightly decreased locomotor activity and significantly reduced rearing and defecation in the hypothyroid group. Hypothyroid rats were also characterized by decreased body weight, sucrose preference, and relative sucrose intake compared to control rats. Hypothyroidism induced reduced brain glucose metabolism in the bilateral motor cortex, the caudate putamen, the cortex cingulate, the nucleus accumbens, and the frontal association cortex. A decreased sucrose preference was positively correlated with metabolic glucose changes in the caudate putamen and the nucleus accumbens. The results indicate that the activity pattern in adult onset hypothyroidism is different from the activity pattern when hypothyroidism is induced in the developmental period of the central nervous system. Decreased sucrose preference in hypothyroid rats may be attributed to anhedonia. Furthermore, these findings suggest there may be a common mechanism underlying adult onset hypothyroidism and depression.

  7. Kinetic analysis of [11C]vorozole binding in the human brain with positron emission tomography.

    Logan, Jean; Kim, Sung Won; Pareto, Deborah; Telang, Frank; Wang, Gene-Jack; Fowler, Joanna S; Biegon, Anat

    2014-01-01

    Using positron emission tomography, we investigated the kinetics of [11C]vorozole ([11C]VOR), a radiotracer for the enzyme aromatase that catalyzes the last step in estrogen biosynthesis. Six subjects were scanned under baseline conditions followed by retest 2 weeks later. The retest was followed by a blocking study with 2.5 mg of the aromatase inhibitor letrozole. The binding potential (BP(A)ND) was estimated from a Lassen plot using the total tissue distribution volume (VT) for baseline and blocked. for the thalamus was found to be 15 times higher than that for the cerebellum. From the letrozole studies, we found that [11C]VOR exhibits a slow binding compartment (small k4) that has a nonspecific and a blockable component. Because of the sensitivity of VT to variations in k4, a common value was used for the four highest binding regions. We also considered the tissue uptake to plasma ratio for 60 to 90 minutes as an outcome measure. Using the ratio method, the difference between the highest and lowest was 2.4 compared to 3.5 for the VT. The ratio method underestimates the high regions but is less variable and may be more suitable for patient studies. Because of its kinetics and distribution, this tracer is not a candidate for a bolus infusion or reference tissue methods.

  8. Positron emission tomography molecular imaging of dopaminergic system in drug addiction.

    Hou, Haifeng; Tian, Mei; Zhang, Hong

    2012-05-01

    Dopamine (DA) is involved in drug reinforcement, but its role in drug addiction remains unclear. Positron emission tomography (PET) is the first technology used for the direct measurement of components of the dopaminergic system in the living human brain. In this article, we reviewed the major findings of PET imaging studies on the involvement of DA in drug addiction, especially in heroin addiction. Furthermore, we summarized PET radiotracers that have been used to study the role of DA in drug addiction. To investigate presynaptic function in drug addiction, PET tracers have been developed to measure DA synthesis and transport. For the investigation of postsynaptic function, several radioligands targeting dopamine one (D1) receptor and dopamine two (D2) receptor are extensively used in PET imaging studies. Moreover, we also summarized the PET imaging findings of heroin addiction studies, including heroin-induced DA increases and the reinforcement, role of DA in the long-term effects of heroin abuse, DA and vulnerability to heroin abuse and the treatment implications. PET imaging studies have corroborated the role of DA in drug addiction and increase our understanding the mechanism of drug addiction.

  9. Pharmacological constraints associated with positron emission tomographic scanning of small laboratory animals

    Hume, S.P.; Gunn, R.N.; Jones, T. [PET Methodology Group, MRC Cyclotron Unit, Hammersmith Hospital, London, W12 0NN (United Kingdom)

    1998-02-01

    With the stated aim of scanning small regions of interest in mice, several high-resolution positron emission tomographic (PET) systems are presently under development. Some, however, have low sensitivity and require high doses of radioactivity to achieve count statistics adequate to reconstruct small volumes. Using in vivo dissociation constants for three carbon-11 labelled ligands previously measured in rat brain, the present paper utilises simple saturation kinetics to estimate the limits on radioactivity and specific activity, to minimise the degree of receptor occupancy and achieve maximal specific binding of the radioligand. The extent of the problem is exemplified by considering a high-affinity ligand (dissociation constant in vitro {proportional_to}0.1 nM; in vivo {proportional_to}5 nmol/kg i.v. injected dose), where routinely produced levels of specific activity ({proportional_to}100 MBq/nmol) would limit the activity injected into mice to {proportional_to}0.1 MBq for a 1% receptor occupancy. If, as is feasible, the new generation of high resolution PET systems requires an injected activity >10 MBq, then a >100-fold increase in specific activity would be needed for tracer kinetics to hold. The paper highlights the need to consider realistically achievable goals if high-resolution PET is to be accepted as a viable methodology to acquire pharmacologically and physiologically accurate ligand-receptor binding data in mice. (orig.) With 2 figs., 14 refs.

  10. A promising new mechanism of ionizing radiation detection for positron emission tomography: modulation of optical properties

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2016-11-01

    Using conventional scintillation detection, the fundamental limit in positron emission tomography (PET) time resolution is strongly dependent on the inherent temporal variances generated during the scintillation process, yielding an intrinsic physical limit for the coincidence time resolution of around 100 ps. On the other hand, modulation mechanisms of the optical properties of a material exploited in the optical telecommunications industry can be orders of magnitude faster. In this paper we borrow from the concept of optics pump-probe measurement to for the first time study whether ionizing radiation can produce modulations of optical properties, which can be utilized as a novel method for radiation detection. We show that a refractive index modulation of approximately 5× {{10}-6} is induced by interactions in a cadmium telluride (CdTe) crystal from a 511 keV photon source. Furthermore, using additional radionuclide sources, we show that the amplitude of the optical modulation signal varies linearly with both the detected event rate and average photon energy of the radiation source.

  11. PETALO, a new concept for a Positron Emission TOF Apparatus based on Liquid xenOn

    Benlloch-Rodriguez, J M

    2016-01-01

    This master thesis presents a new type of Positron Emission TOF Apparatus using Liquid xenOn (PETALO). The detector is based in the Liquid Xenon Scintillating Cell (LXSC). The cell is a box filled with liquid xenon (LXe) whose transverse dimensions are chosen to optimize packing and with a thickness optimized to contain a large fraction of the incoming photons. The entry and exit faces of the box (relative to the incoming gammas direction) are instrumented with large silicon photomultipliers (SiPMs), coated with a wavelength shifter, tetraphenyl butadiene (TPB). The non-instrumented faces are covered by reflecting Teflon coated with TPB. In this thesis we show that the LXSC can display an energy resolution of 5% FWHM, much better than that of conventional solid scintillators such as LSO/LYSO. The LXSC can measure the interaction point of the incoming photon with a resolution in the three coordinates of 1 mm. The very fast scintillation time of LXe (2 ns) and the availability of suitable sensors and electronic...

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

    Amarnath eChallapalli

    2016-02-01

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

  13. Speech disorders in olivopontocerebellar atrophy correlate with positron emission tomography findings

    Kluin, K.J.; Gilman, S.; Markel, D.S.; Koeppe, R.A.; Rosenthal, G.; Junck, L.

    1988-06-01

    We compared the severity of ataxic and spastic dysarthria with local cerebral metabolic rates for glucose (lCMRGlc) in 30 patients with olivopontocerebellar atrophy (OPCA). Perceptual analysis was used to examine the speech disorders, and rating scales were devised to quantitate the degree of ataxia and spasticity in the speech of each patient. lCMRGlc was measured with /sup 18/F-2-fluoro-2-deoxy-D-glucose and positron emission tomography (PET). PET studies revealed marked hypometabolism in the cerebellar hemispheres, cerebellar vermis, and brainstem of OPCA patients compared with 30 control subjects. With data normalized to the cerebral cortex, a significant inverse correlation was found between the severity of ataxia in speech and the lCMRGlc within the cerebellar vermis, cerebellar hemispheres, and brainstem, but not within the thalamus. No significant correlation was found between the severity of spasticity in speech and lCMRGlc in any of these structures. The findings support the view that the severity of ataxia in speech in OPCA is related to the functional activity of the cerebellum and its connections in the brainstem.

  14. Experience with carbon-11 choline positron emission tomography in prostate carcinoma

    Kotzerke, J.; Neumaier, B.; Guhlmann, A.; Reske, S.N. [Ulm Univ. (Germany). Dept. of Nuclear Medicine; Prang, J.; Volkmer, B.; Kleinschmidt, K.; Hautmann, R. [Dept. of Urology, Univ. of Ulm (Germany)

    2000-09-01

    We investigated the potential of carbon-11 choline positron emission tomography (PET) for the detection of lymph node and bone metastases in prostate cancer. A total of 23 patients were studied (known metastases: 8; suspicion of metastases: 3; primary staging: 12). Whole-body PET imaging was performed 5 min after injection of the tracer and completed within 1 h. Focally increased tracer uptake in bone or abdominal lymph node regions was interpreted as representing tumour involvement. All known bone and lymph node metastases could be recognized by [{sup 11}C]choline PET. One out of ten negative scans for primary staging was false-negative (lymph node <1 cm) and one out of two positive scans was false-positive with regard to lymph node involvement (focal bowel activity). It is concluded that [{sup 11}C]choline PET is a promising new tool for the primary staging of prostate cancer, with lymph node and bone metastases demonstrating high tracer uptake. Therapeutic management could be influenced by these results in that the technique may permit avoidance of surgical lymph node exploration. (orig.)

  15. Assessment of myocardial metabolism by positron emission tomography; Stoffwechseluntersuchungen des Herzens mit der Positronenemissionstomographie

    Bengel, F.M.; Schwaiger, M. [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik und Poliklinik

    1999-06-01

    In combination with a variety of tracers, positron emission tomography does provide noninvasive quantitative information not only about myocardial utilisation of substrates such as glucose or free fatty acids, but also about overall oxidative metabolism. PET studies of myocardial metabolism have substantially contributed to an improved understanding of regulatory mechanism as well as interaction between different substrates under normal conditions as well as under pathologic conditions such as ischemia, heart failure or diabetes mellitus, and will continue to do so in the future. (orig.) [German] Fuer die Positronenemissionstomographie stehen verschiedene Tracer zur Verfuegung, die am menschlichen Herzen nichtinvasive Quantifizierung der Utilisation von Substraten wie Glukose oder freien Fettsaeuren, aber auch des gesamten sauerstoffabhaengigen Metabolismus ermoeglichen. Stoffwechseluntersuchungen des Herzens mit der PET haben zu einem genaueren Verstaendnis von Regulationsmechanismen und Interaktionen zwischen verschiedenen Substraten sowohl im Normalzustand als auch unter pathologischen Bedingungen wie etwa bei ischaemischen Syndromen, Herzinsuffizienz oder Diabetis mellitus beigetragen. Insbesondere durch Untersuchungen von metabolischen Auswirkungen verschiedener Therapieansaetze bei Herzerkrankungen und zur Vorhersage der Effektivitaet solcher therapeutischer Strategien kann die PET auch in Zukunft einen Beitrag zur Weiterentwicklung der Kardiologie leisten. (orig.)

  16. 18F-fluorodeoxyglucose positron emission tomography might be useful for diagnosis of hepatic amyloidosis

    Tawada A

    2014-06-01

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

  17. Incidental finding of a left over guide wire on a positron emission tomography

    Yap, Kok Hooi; Lee, Phong Teck; Buch, Mamta; Rammohan, Kandadai Seshadri

    2012-12-15

    The Seldinger technique is commonly used cannulate vessels for radiographical procedures. Loss of a guide wire into the circulation is a rare and preventable complication. It is often noticed by chance during routine radiographs. However, there is a lack of reported cases of incidental fin dings of leftover guide wire on a PET scan. An intravascular foreign body should be retrieved as soon as the diagnosis is made, to prevent complications such as embolisation or vascular damage by fractured wires. Interventional radiology is the method of choice for retrieval. We report a rare case of the coincidental finding of a lost guide wire on a PET scan. A 37 year old man presented with psychotic episodes, thigh weakness, weight gain, increased appetite and leg cramps. He was subsequently diagnosed with cushing syndrome secondary to ectopic adrenocorticotropic secretion from a right lung tumour. He subsequently underwent a staging positron emission tomography (PET) scan. The lung tumour had no uptake on PET bit had increased activity uptake on octreotide scanning. These appearances were suggestive of with carcinoid tumour. The PET scan also revealed an incidental finding of a leftover guide wire used during peripheral inserted central catheter (PICC) recently. The wire extended from right atrium to inferior vena cava. It also showed a high uptake in the adrenal glands, indicating hyperplasia, which was most likely due to adrenocorticotropic hormone stimulation. He underwent a percutaneous wire retrieval via the right femoral vein in a cardiac catheterisation laboratory and was transferred to a thoracic surgical unit for lung tumor resection.

  18. Iterative reconstruction using a Monte Carlo based system transfer matrix for dedicated breast positron emission tomography.

    Saha, Krishnendu; Straus, Kenneth J; Chen, Yu; Glick, Stephen J

    2014-08-28

    To maximize sensitivity, it is desirable that ring Positron Emission Tomography (PET) systems dedicated for imaging the breast have a small bore. Unfortunately, due to parallax error this causes substantial degradation in spatial resolution for objects near the periphery of the breast. In this work, a framework for computing and incorporating an accurate system matrix into iterative reconstruction is presented in an effort to reduce spatial resolution degradation towards the periphery of the breast. The GATE Monte Carlo Simulation software was utilized to accurately model the system matrix for a breast PET system. A strategy for increasing the count statistics in the system matrix computation and for reducing the system element storage space was used by calculating only a subset of matrix elements and then estimating the rest of the elements by using the geometric symmetry of the cylindrical scanner. To implement this strategy, polar voxel basis functions were used to represent the object, resulting in a block-circulant system matrix. Simulation studies using a breast PET scanner model with ring geometry demonstrated improved contrast at 45% reduced noise level and 1.5 to 3 times resolution performance improvement when compared to MLEM reconstruction using a simple line-integral model. The GATE based system matrix reconstruction technique promises to improve resolution and noise performance and reduce image distortion at FOV periphery compared to line-integral based system matrix reconstruction.

  19. Quality assurance set-up for a new positron emission tomography detector

    Cortinovis, Daniele; Xu, Chen; Zvolsky, Milan [DESY, Hamburg (Germany); Hamburg Univ. (Germany); Garutti, Erika [Hamburg Univ. (Germany); Silenzi, Alessandro [DESY, Hamburg (Germany)

    2013-07-01

    The PicoSEC-MCNet Project (PICOsecond Siliconphotomultiplier-Electronics- and Crystal research-Marie-Curie-Network) aims to develop a new class of ultra-fast photon detectors for High Energy Physics (HEP) and Positron Emission Tomography (PET). This actual technology development is covered in the EndoTOFPET-US project. A new Time Of Flight PET detector will improve the diagnosis capability of pancreatic and prostate tumors with unprecedented spatial resolution. The detector consists of two parts: a PET head mounted on an ultrasound probe and an external plate. Photons are detected by scintillating crystals individually readout by silicon photomultipliers (SiPMs). Their fast response allows to meet the critical requirement of at least 200 ps (FWHM) coincidence time resolution, essential for a spatial resolution of 3 cm along the Line Of Response (LOR) and efficient background rejection. DESY together with Hamburg University are responsible for the quality assurance and the commissioning of the whole system, and the necessary infrastructure is being set up. Within this task, the light yield uniformity for the combined scintillator-SiPM system of the external plate must be measured. This talk will introduce and describe the set-up which will allows a fast, automatic and high precision measurement of the light yield for the 4096 combined scintillator-SiPMs of the external plate.

  20. Evaluation of Glucose Uptake in Normal and Cancer Cell Lines by Positron Emission Tomography.

    Maddalena, Francesca; Lettini, Giacomo; Gallicchio, Rosj; Sisinni, Lorenza; Simeon, Vittorio; Nardelli, Anna; Venetucci, Angela Assunta; Storto, Giovanni; Landriscina, Matteo

    2015-01-01

    To date, there is no definitive demonstration of the utility of positron emission tomography (PET) in studying glucose metabolism in cultured cell lines. Thus, this study was designed to compare PET to more standardized methods for the quantitative assessment of glucose uptake in nontransformed and transformed living cells and to validate PET for metabolic studies in vitro. Human colon and breast carcinoma cell lines and mouse embryo fibroblasts were evaluated for [(18)F]fluorodeoxyglucose ([(18)F]FDG) uptake by PET and autoradiography and 2-deoxyglucose (2-DG) incorporation by colorimetric assay and analyzed for the radiotoxic effects of [(18)F]FDG and the expression levels of glucose transporters. Indeed, [(18)F]FDG incorporation on PET was comparable to [(18)F]FDG uptake by autoradiography and 2-DG incorporation by colorimetric assay, although radiotracer-based methods exhibited more pronounced differences between individual cell lines. As expected, these data correlated with glucose transporters 1 to 4 and hexokinase II expression in tumor cell lines and mouse fibroblasts. Notably, [(18)F]FDG incorporation resulted in low apoptotic rates, with fibroblasts being slightly more sensitive to radiotracer-induced cell death. The quantitative analysis of [(18)F]FDG uptake in living cells by PET represents a valuable and reproducible method to study tumor cell metabolism in vitro, being representative of the differences in the molecular profile of normal and tumor cell lines.

  1. Utility of positron emission tomography-magnetic resonance imaging in musculoskeletal imaging

    Ammar A Chaudhry; Maryam Gul; Elaine Gould; Mathew Teng; Kevin Baker; Robert Matthews

    2016-01-01

    Differentiation between neoplastic and nonneoplastic conditions magnetic resonance imaging(MRI) has established itself as one of the key clinical tools in evaluation of musculoskeletal pathology. However, MRI still has several key limitations which require supplemental information from additional modalities to complete evaluation of various disorders. This has led to the development hybrid positron emission tomography(PET)-MRI which is rapidly evolving to address key clinical questions by using the morphological strengths of MRI and functional information of PET imaging. In this article, we aim to review physical principles and techniques of PET-MRI and discuss clinical utility of functional information obtained from PET imaging and structural information obtained from MRI imaging for the evaluation of musculoskeletal pathology. More specifically, this review highlights the role of PET-MRI in musculoskeletal oncology including initial diagnosis and staging, treatment planning and posttreatment follow-up. Also we will review utility of PET-MRI in evaluating musculoskeletal infections(especially in the immunocompromised and diabetics) and inflammatory condition. Additionally, common pitfalls of PET-MRI will be addressed.

  2. Positron emission mammography with tomographic acquisition using dual planar detectors: initial evaluations

    Mark F Smith; Raymond R Raylman; Stan Majewski; Andrew G Weisenberger

    2004-05-01

    Positron emission mammography (PEM) with tomographic acquisition using dual planar detectors rotating about the breast can obtain complete angular sampling and has the potential to improve activity estimation compared with PEM using stationary detectors. PEM tomography (PEMT) was compared with stationary PEM for point source and compressed breast phantom studies performed with a compact dual detector system. The acquisition geometries were appropriate for the target application of PEM guidance of stereotactic core biopsy. Images were reconstructed with a three-dimensional iterative maximum likelihood expectation maximization algorithm. PEMT eliminated blurring normal to the detectors seen with stationary PEM. Depth of interaction effects distorted the shape of the point spread functions for PEMT as the angular range from normal incidence of lines of response used in image reconstruction increased. Streak artifacts in PEMT for large detector rotation increments led to the development of an expression for the maximum rotation increment that maintains complete angular sampling. Studies with a compressed breast phantom were used to investigate contrast and signal-to-noise ratio (SNR) trade-offs for different sized spherical tumor models. PEMT and PEM both had advantages depending on lesion size and detector separation. The most appropriate acquisition method for specific detection or quantitation tasks requires additional investigation.

  3. FPGA-Based Front-End Electronics for Positron Emission Tomography.

    Haselman, Michael; Dewitt, Don; McDougald, Wendy; Lewellen, Thomas K; Miyaoka, Robert; Hauck, Scott

    2009-02-22

    Modern Field Programmable Gate Arrays (FPGAs) are capable of performing complex discrete signal processing algorithms with clock rates above 100MHz. This combined with FPGA's low expense, ease of use, and selected dedicated hardware make them an ideal technology for a data acquisition system for positron emission tomography (PET) scanners. Our laboratory is producing a high-resolution, small-animal PET scanner that utilizes FPGAs as the core of the front-end electronics. For this next generation scanner, functions that are typically performed in dedicated circuits, or offline, are being migrated to the FPGA. This will not only simplify the electronics, but the features of modern FPGAs can be utilizes to add significant signal processing power to produce higher resolution images. In this paper two such processes, sub-clock rate pulse timing and event localization, will be discussed in detail. We show that timing performed in the FPGA can achieve a resolution that is suitable for small-animal scanners, and will outperform the analog version given a low enough sampling period for the ADC. We will also show that the position of events in the scanner can be determined in real time using a statistical positioning based algorithm.

  4. Eyeblink conditioning in unmedicated schizophrenia patients: a positron emission tomography study.

    Parker, Krystal L; Andreasen, Nancy C; Liu, Dawei; Freeman, John H; O'Leary, Daniel S

    2013-12-30

    Previous studies suggest that patients with schizophrenia exhibit dysfunctions in a widely distributed circuit-the cortico-cerebellar-thalamic-cortical circuit, or CCTCC-and that this may explain the multiple cognitive deficits observed in the disorder. This study uses positron emission tomography (PET) with O(15) H₂O to measure regional cerebral blood flow (rCBF) in response to a classic test of cerebellar function, the associative learning that occurs during eyeblink conditioning, in a sample of 20 unmedicated schizophrenia patients and 20 closely matched healthy controls. The PET paradigm examined three phases of acquisition and extinction (early, middle and late). The patients displayed impaired behavioral performance during both acquisition and extinction. The imaging data indicate that, compared to the control subjects, the patients displayed decreases in rCBF in all three components of the CCTCC during both acquisition and extinction. Specifically, patients had less rCBF in the middle and medial frontal lobes, anterior cerebellar lobules I/V and VI, as well as the thalamus during acquisition and although similar areas were found in the frontal lobe, ipsilateral cerebellar lobule IX showed consistently less activity in patients during extinction. Thus this study provides additional support for the hypothesis that patients with schizophrenia have a cognitive dysmetria--an inability to smoothly coordinate many different types of mental activity--that affects even a very basic cognitive task that taps into associative learning.

  5. A fast rebinning algorithm for 3D positron emission tomography using John's equation

    Defrise, Michel; Liu, Xuan

    1999-08-01

    Volume imaging in positron emission tomography (PET) requires the inversion of the three-dimensional (3D) x-ray transform. The usual solution to this problem is based on 3D filtered-backprojection (FBP), but is slow. Alternative methods have been proposed which factor the 3D data into independent 2D data sets corresponding to the 2D Radon transforms of a stack of parallel slices. Each slice is then reconstructed using 2D FBP. These so-called rebinning methods are numerically efficient but are approximate. In this paper a new exact rebinning method is derived by exploiting the fact that the 3D x-ray transform of a function is the solution to the second-order partial differential equation first studied by John. The method is proposed for two sampling schemes, one corresponding to a pair of infinite plane detectors and another one corresponding to a cylindrical multi-ring PET scanner. The new FORE-J algorithm has been implemented for this latter geometry and was compared with the approximate Fourier rebinning algorithm FORE and with another exact rebinning algorithm, FOREX. Results with simulated data demonstrate a significant improvement in accuracy compared to FORE, while the reconstruction time is doubled. Compared to FOREX, the FORE-J algorithm is slightly less accurate but more than three times faster.

  6. Function of the shoulder muscles during arm elevation: an assessment using positron emission tomography

    Omi, Rei; Sano, Hirotaka; Ohnuma, Masahiro; Kishimoto, Koshi N; Watanuki, Shoichi; Tashiro, Manabu; Itoi, Eiji

    2010-01-01

    Although 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography (PET) has been used for the assessment of skeletal muscle activities, its application to the shoulder muscles is only sparse. The purpose of this study was to investigate the activities of the shoulder muscles during arm elevation using PET. Six healthy volunteers performed an arm elevation exercise before and after FDG injection. The exercise consisted of 200 repetitions of arm elevation in the scapular plane with a 0.25-kg weight fixed to the wrist on both arms. PET examination was performed 50 min after FDG injection. For control data, PET scan was repeated for each subject on a separate day without any exercise. The volume of interest was established for each shoulder muscle. The subscapularis was divided into three portions (superior, middle, and inferior). The standardized uptake value (SUV) was calculated in each muscle to quantify its activity. The SUVs increased significantly after exercise in the deltoid, supraspinatus, and the superior portion of subscapularis. Among three divided portions of the subscapularis, the SUV of the superior one-third was significantly greater than the rest of the muscle after exercise. Our current study clearly indicated that there were two functionally different portions in the subscapularis muscle and the superior one-third played an important role during arm elevation in the scapular plane. PMID:20298439

  7. Significance of incidental focal uptake in prostate on 18-fluoro-2-deoxyglucose positron emission tomography CT images

    Han, E J; H O, J; Choi, W H; Yoo, I R; Chung, S K

    2010-01-01

    To evaluate the clinical significance of incidental focal prostate fluorodeoxyglucose (FDG) uptake, we reviewed 18-F-FDG positron emission tomography (PET)/CT scans from 2003 to 2007 and selected cases with focal FDG uptake in prostate. Cases of known prostate cancer were excluded. The maximum standardised uptake value (SUVmax), site (central or peripheral) and pattern (discrete or ill-defined) of FDG uptake, calcification (present or absent) and prostate volume (

  8. Kinetic Analysis of Dynamic Positron Emission Tomography Data using Open-Source Image Processing and Statistical Inference Tools

    Hawe, David; Hernández Fernández, Francisco R.; O’Suilleabháin, Liam; Huang, Jian; Wolsztynski, Eric; O’Sullivan, Finbarr

    2012-01-01

    In dynamic mode, positron emission tomography (PET) can be used to track the evolution of injected radio-labelled molecules in living tissue. This is a powerful diagnostic imaging technique that provides a unique opportunity to probe the status of healthy and pathological tissue by examining how it processes substrates. The spatial aspect of PET is well established in the computational statistics literature. This article focuses on its temporal aspect. The interpretation of PET time-course da...

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

    纪勇

    2013-01-01

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

  10. Lhermitte-Duclos disease presenting with positron emission tomography-magnetic resonance fusion imaging: a case report

    Calabria Ferdinando

    2012-03-01

    Full Text Available Abstract Introduction Lhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum is an extremely rare tumor. It is a slowly enlarging mass within the cerebellar cortex. The majority of cases are diagnosed in the third or fourth decade of life. Case presentation We report the case of a 37-year-old Caucasian woman who underwent positron emission tomography-computed tomography with fluorine-18-fluorodeoxyglucose for evaluation of a solitary lung node. No pathological uptake was detected in the solitary lung node but the positron emission tomography-computed tomography of her brain showed intense tracer uptake, suggestive of a malignant neoplasm, in a mass in her left cerebellar lobe. Our patient had experienced two years of occipital headache and movement disorder. Subsequently, magnetic resonance imaging was performed with contrast agent administration, showing a large subtentorial mass in her left cerebellar hemisphere, with compression and dislocation of the fourth ventricle. Metabolic data provided by positron emission tomography and morphological magnetic resonance imaging views were fused in post-processing, allowing a diagnosis of dysplastic gangliocytoma with increased glucose metabolism. Total resection of the tumor was performed and histological examination confirmed the diagnosis of Lhermitte-Duclos disease. Conclusions Our case indicates that increased uptake of fluorine-18-fluorodeoxyglucose may be misinterpreted as a neoplastic process in the evaluation of patients with Lhermitte-Duclos disease, but supports the usefulness of integrated positron emission tomography-magnetic resonance imaging in the exact pathophysiologic explanation of this disease and in making the correct diagnosis. However, an accurate physical examination and exact knowledge of clinical data is of the utmost importance.

  11. Particle physics methodologies applied to time-of-flight positron emission tomography with silicon-photomultipliers and inorganic scintillators

    Leming, Edward J

    2015-01-01

    Positron emission tomography, or PET, is a medical imaging technique which has been used in clinical environments for over two decades. With the advent of fast timing detectors and scintillating crystals, it is possible to envisage improvements to the technique\\ud with the inclusion of time-of-flight capabilities. In this context, silicon photomultipliers coupled to fast inorganic LYSO crystals are investigated as a possible technology choice. As part of the ENVISION collaboration a range of ...

  12. Heterogeneity of Monosymptomatic Resting Tremor in a Prospective Study: Clinical Features, Electrophysiological Test, and Dopamine Transporter Positron Emission Tomography

    Hua-Guang Zheng; Rong Zhang; Xin Li; Fang-Fei Li; Ya-Chen Wang; Xue-Mei Wang; Ling-Long Lu; Tao Feng

    2015-01-01

    Background: The relationship between monosymptomatic resting tremor (mRT) and Parkinson′s disease (PD) remains controversial. In this study, we aimed to assess the function of presynaptic dopaminergic neurons in patients with mRT by dopamine transporter positron emission tomography (DAT-PET) and to evaluate the utility of clinical features or electrophysiological studies in differential diagnosis. Methods: Thirty-three consecutive patients with mRT were enrolled prospectively. The Unified...

  13. Lymphocytic Thyroiditis Presenting as a Focal Uptake on 18F-Fluorodeoxyglucose Positron Emission Tomography: A Case Report

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

    2011-12-15

    Diffuse increased uptake on 18F-Fluorodeoxyglucose Positron Emission Tomography (18F FDG PET) is a well-known finding of the lymphocytic thyroiditis. Nevertheless, a pathologic confirmation is needed in cases of a focal 18F FDG uptake in the thyroid gland. This article reports a rare case of a focal 18F FDG uptake lesion by PET, which was revealed pathologically to be lymphocytic thyroiditis

  14. [18F]Fluorodeoxyglucose-positron emission tomography screening for lung cancer: a systematic review and meta-analysis

    Chien, Chun-Ru; Liang, Ji-An; Chen, Jin-Hua; Wang, Hsiao-Nin; Lin, Cheng-Chieh; Chen, Chih-Yi; Wang, Pin-Hui; Kao, Chia-Hung; Yeh, Jun-Jun

    2013-01-01

    Abstract Rationale and objectives: Although low-dose computed tomography (CT) is a recommended modality for lung cancer screening in high-risk populations, the role of other modalities, such as [18F]fluorodeoxyglucose-positron emission tomography (PET), is unclear. We conducted a systematic review to describe the role of PET in lung cancer screening. Materials and methods: A systematic review was conducted by reviewing primary studies focusing on PET screening for lung cancer until July 2012....

  15. Comparison of diffuse optical tomography of human breast with whole-body and breast-only positron emission tomography

    Konecky, Soren D.; Choe, Regine; Corlu, Alper; Lee, Kijoon; Wiener, Rony; Srinivas, Shyam M.; Saffer, Janet R.; FREIFELDER, RICHARD; Karp, Joel S.; Hajjioui, Nassim; Azar, Fred; Yodh, Arjun G.

    2008-01-01

    We acquire and compare three-dimensional tomographic breast images of three females with suspicious masses using diffuse optical tomography (DOT) and positron emission tomography (PET). Co-registration of DOT and PET images was facilitated by a mutual information maximization algorithm. We also compared DOT and whole-body PET images of 14 patients with breast abnormalities. Positive correlations were found between total hemoglobin concentration and tissue scattering measured by DOT, and fluor...

  16. Quantification of myocardial perfusion using cardiac magnetic resonance imaging correlates significantly to rubidium-82 positron emission tomography in patients with severe coronary artery disease

    Qayyum, Abbas A; Hasbak, Philip; Larsson, Henrik B W

    2014-01-01

    INTRODUCTION: Aim was to compare absolute myocardial perfusion using cardiac magnetic resonance imaging (CMRI) based on Tikhonov's procedure of deconvolution and rubidium-82 positron emission tomography (Rb-82 PET). MATERIALS AND METHODS: Fourteen patients with coronary artery stenosis underwent ...

  17. Traditional versus up-front [F-18] fluorodeoxyglucose-positron emission tomography staging of non-small-cell lung cancer : A Dutch cooperative randomized study

    Herder, GJM; Kramer, H; Hoekstra, OS; Smit, EF; Pruim, J; van Tinteren, H; Comans, EF; Verboom, P; Uyl-De Groot, CA; Welling, A; Paul, MA; Boers, M; Postmus, PE; Teule, GJ; Groen, HJM

    2006-01-01

    Purpose We investigated whether application of positron emission tomography (PET) immediately after first presentation might simplify staging while maintaining accuracy, as compared with traditional strategy in routine clinical setting. Methods At first presentation, patients with a provisional diag

  18. Is \\gamma-ray emission from novae affected by interference effects in the 18F(p,\\alpha)15O reaction?

    Laird, A M; Murphy, A St J; Wimmer, K; Chen, A A; Deibel, C M; Faestermann, T; Fox, S P; Fulton, B R; Hertenberger, R; Irvine, D; José, J; Longland, R; Mountford, D; Sambrook, B; Seiler, D; Wirth, H -F

    2012-01-01

    The 18F(p,\\alpha)15O reaction rate is crucial for constraining model predictions of the \\gamma-ray observable radioisotope 18F produced in novae. The determination of this rate is challenging due to particular features of the level scheme of the compound nucleus, 19Ne, which result in interference effects potentially playing a significant role. The dominant uncertainty in this rate arises from interference between J\\pi=3/2+ states near the proton threshold (Sp = 6.411 MeV) and a broad J\\pi=3/2+ state at 665 keV above threshold. This unknown interference term results in up to a factor of 40 uncertainty in the astrophysical S-factor at nova temperatures. Here we report a new measurement of states in this energy region using the 19F(3He,t)19Ne reaction. In stark contrast with previous assumptions we find at least 3 resonances between the proton threshold and Ecm=50 keV, all with different angular distributions. None of these are consistent with J\\pi= 3/2+ angular distributions. We find that the main uncertainty ...

  19. Methods and applications of positron-based medical imaging

    Herzog, H. [Institute of Medicine, Forschungszentrum Juelich, D-52425 Juelich (Germany)]. E-mail: h.herzog@fz-juelich.de

    2007-02-15

    Positron emission tomography (PET) is a diagnostic imaging method to examine metabolic functions and their disorders. Dedicated ring systems of scintillation detectors measure the 511 keV {gamma}-radiation produced in the course of the positron emission from radiolabelled metabolically active molecules. A great number of radiopharmaceuticals labelled with {sup 11}C, {sup 13}N, {sup 15}O, or {sup 18}F positron emitters have been applied both for research and clinical purposes in neurology, cardiology and oncology. The recent success of PET with rapidly increasing installations is mainly based on the use of [{sup 18}F]fluorodeoxyglucose (FDG) in oncology where it is most useful to localize primary tumours and their metastases.

  20. Hyperventilation-induced reduction in cerebral blood flow: Assessment by positron emission tomography

    Bednarczyk, E.M.; Rutherford, W.F.; Leisure, G.P.; Munger, M.A.; Panacek, E.A.; Miraldi, F.D.; Green, J.A. (Case Western Reserve Univ. School of Medicine, Cleveland, OH (USA))

    1990-05-01

    The use of positron emission tomography (PET) has been well documented as a relatively noninvasive method of measuring cerebral blood flow (CBF), both globally and regionally. The utility of readily detecting alterations in CBF is apparent, particularly when applied to the evaluation of therapeutic interventions thought to influence CBF. We report the effects of hypocapnia, an experimental condition of known cerebral vasoconstriction, in ten normal volunteers. Subjects had brain blood flow evaluated utilizing H215O as the positron emitter before and after approximately five minutes of hyperventilation. Baseline CBF was measured as a mean +/- SD of 61.2 +/- 16.3 mL/min/100 g of tissue. Mean baseline arterial blood gas values were PaO2 107.4 +/- 14 mm Hg, PaCO2 37.7 +/- 0.89 mm Hg, and pH 7.39 (calculated from mean (H+)). Post hyperventilation, global CBF was measured as 31.1 +/- 10.8 mL/min/100 g. Mean arterial blood gas values were PaO2 141.7 +/- 21 mm Hg, PaCO2 19.7 +/- 5 mm Hg, and pH 7.63 (calculated from mean (H+)). CBF decreased by a mean of 49.5 +/- 11 percent. Data analysis using the Student's t-test showed a significant change over baseline in PaCO2 (p less than 0.001) and CBF (p less than 0.001), in the hyperventilated state. Correlations were noted between the decrease in CBF and change in PaCO2 (r = 0.81) as well as between hyperventilation PaCO2 and the change in CBF (r = 0.97). We conclude that, as measured by PET, CBF decreases significantly during a state of artificial hyperventilation to a degree consistent with results seen using other methods. PET appears to be a valuable tool in the assessment of interventions that could influence CBF.

  1. Fundamental studies of myocardial defect size quantification using positron emission tomography and single photon emission computed tomography

    Yoneyama, Tatsuya [Kanazawa Univ. (Japan). School of Medicine

    2001-04-01

    In Flurine-18 fluorodeoxyglucose ({sup 18}F-FDG) positron emission tomography (PET) acquisition, a transmission scan is usually performed before the PET tracer injection (cold transmission method), followed by a subsequent emission scan. However, this procedure is time consuming. An alternative approach, in which the transmission scan is performed after the emission scan (hot transmission method), would significantly reduce the time required for data acquisition. Recently, three-dimensional PET acquisition (3D PET) has become available. The counting sensitivity is much higher in 3D PET than in conventional two-dimensional PET (2D PET), resulting in a shorter acquisition time and reduced radiation exposure for the patient. On the other hand, {sup 18}F-FDG imaging using single photon emission computed tomography (SPECT), a more widely available method than PET, has emerged as an alternative to PET. The purpose of this study was to investigate the accuracy of measurement of myocardial defect sizes by these new techniques, using a chest phantom. Acquisitions were performed using an elliptical cylinder chest phantom. Plastic inserts, ranging in size from 2-60% of the myocardium (n=12), were used as simulated models of transmural myocardial infarction. Fluorine-18 was given into each part of the phantom. PET imaging with cold and hot transmission methods, 3D PET, and SPECT imaging were performed with different acquisition times and different radioisotope concentrations. All PET and SPECT data were analyzed using a semiquantitative polar map approach. Defect sizes were quantified using various cutoff thresholds, and were expressed as a percentage of the left ventricular myocardium. The PET and SPECT measurements were compared with the true defect sizes. Among the various cutoff levels tested, the mean absolute difference between the measured and true defect sizes was minimal at 50% of peak activity for both PET and SPECT. The PET measurements with the hot transmission

  2. 18F-AV-1451 positron emission tomography in Alzheimer’s disease and progressive supranuclear palsy

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

    2017-01-01

    Abstract The ability to assess the distribution and extent of tau pathology in Alzheimer’s disease and progressive supranuclear palsy in vivo would help to develop biomarkers for these tauopathies and clinical trials of disease-modifying therapies. New radioligands for positron emission tomography have generated considerable interest, and controversy, in their potential as tau biomarkers. We assessed the radiotracer 18F-AV-1451 with positron emission tomography imaging to compare the distribution and intensity of tau pathology in 15 patients with Alzheimer’s pathology (including amyloid-positive mild cognitive impairment), 19 patients with progressive supranuclear palsy, and 13 age- and sex-matched controls. Regional analysis of variance and a support vector machine were used to compare and discriminate the clinical groups, respectively. We also examined the 18F-AV-1451 autoradiographic binding in post-mortem tissue from patients with Alzheimer’s disease, progressive supranuclear palsy, and a control case to assess the 18F-AV-1451 binding specificity to Alzheimer’s and non-Alzheimer’s tau pathology. There was increased 18F-AV-1451 binding in multiple regions in living patients with Alzheimer’s disease and progressive supranuclear palsy relative to controls [main effect of group, F(2,41) = 17.5, P 2.2, P’s 2.7, P’s < 0.02). The support vector machine assigned patients’ diagnoses with 94% accuracy. The post-mortem autoradiographic data showed that 18F-AV-1451 strongly bound to Alzheimer-related tau pathology, but less specifically in progressive supranuclear palsy. 18F-AV-1451 binding to the basal ganglia was strong in all groups in vivo. Postmortem histochemical staining showed absence of neuromelanin-containing cells in the basal ganglia, indicating that off-target binding to neuromelanin is an insufficient explanation of 18F-AV-1451 positron emission tomography data in vivo, at least in the basal ganglia. Overall, we confirm the potential of 18F

  3. Prognostic value of 18-fluorodeoxyglucose positron emission tomography-computed tomography in resectable colorectal cancer

    Jang Eun Lee; Sang Woo Kim; Jin Su Kim; Kyu Yong Choi; Won Kyung Kang; Seong Taek Oh; Ie Ryung Yoo

    2012-01-01

    AIM:To assess the prognostic value of preoperative 18 fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) in patients with resectable colorectal cancer.METHODS:One hundred sixty-three patients with resectable colorectal cancer who underwent FDG-PET/CT before surgery were included.Patient data including pathologic stage at presentation,histology,treatment,disease-free survival and the maximum standardized uptake value (SUVmax) of the primary tumor on FDGPET/CT were retrospectively analyzed.Median follow up duration was 756 (range,419-1355).The primary end point was disease-free survival.RESULTS:Twenty-five of 163 patients (15.3%) had recurrences.The median SUVmax values of the recurrence and no-recurrence groups were 8.9 (range,5-24) and 8.2 (range,0-23,P =0.998).Receiver operating characteristic (ROC) curve analysis showed no significant association between SUVmax and recurrence (area under the curve =0.5,P =0.998,95%CI:0.389-0.611).Because a statistically significant value was not found,SUVmax was dichotomized at its median of 8.6.The disease-free survival curve was analyzed using the median SUVmax (8.6) as the cut off.Univariate and multivariate analysis did not provide evidence that disease-free survival rates for the subgroups defined by the median SUVmax were significantly different (P =0.52,P =0.25).CONCLUSION:Our study suggests that the high FDG uptake of primary mass in resectable colorectal cancer doesn't have a significant relationship with tumor recurrence and disease-free survival.

  4. Positron emission tomography (PET) study of patients with pituitary adenoma using labeled amino acid

    Mineura, Katsuyoshi; Sasajima, Toshio; Sakamoto, Tetsuya; Kowada, Masayoshi (Akita Univ. (Japan). Hospital); Shishido, Fumio; Uemura, Kazuo

    1989-12-01

    Four cases with pituitary adenomas were studied using {sup 11}C-L-methionine (C-11 Met) positron-emission tomography (PET). The C-11 Met was intravenously administered at a dose of 0.6 mCi/kg. The uptake of the tracer for tumors was calculated on the PET images 45 min after the injection; the uptake index was represented as a percentage of the total count in the arterial blood over a period of 45 min. In all cases, the C-11 Met accumulated intensely in the tumor regions; the PET images clearly delineated the extent of the tumor. The C-11 Met uptake index for pituitary adenomas varied widely from 3.94 x 10{sup -2}% to 15.36 x 10{sup -2}%, with a mean of 7.87 x 10{sup -2}%. These indices for the tumors increased markedly in comparison with that of the contralateral left temporal gray matter as a nontumor region (1.89 x 10{sup -2}% to 2.43 x 10{sup -2}% with a mean of 2.06 x 10{sup -2}%). In a case of prolactinoma, repeated PET following bromocriptine treatment showed a decrease in the C-11 Met uptake index; this decrease reflected changes in the serum prolactin value. In another case with ACTH-producing adenoma, the T/NT (tumor/nontumor) ratio fell from 3.44 to 2.40; however, the C-11 Met index remained unchanged. C-11 Met PET images facilitate determining the extent of pituitary adenomas and the monitoring of tumor response to treatment. Further application may give useful knowledge on the amino-acid metabolism of the tumor. (author).

  5. Evaluation of Positron Emission Tomographic Tracers for Imaging of Papillomavirus-Induced Tumors in Rabbits

    Sonja Probst

    2014-01-01

    Full Text Available In this study, simultaneous positron emission tomography (PET/magnetic resonance (MR imaging was employed to evaluate the feasibility of the PET tracers 2-deoxy-2-18F-fluoro-D-glucose (18F-FDG, 11C-choline, and 18F-fluorothymidine (18F-FLT to detect papillomavirus-induced tumors in an established rabbit model system. The combined PET/MR allowed the analysis of tracer uptake of the tumors using the morphologic information acquired by MR. New Zealand White rabbits were infected with cottontail rabbit papillomavirus genomes and were imaged for up to 10 months with a simultaneous PET/MR system during the course of infection. The uptake characteristics of the PET tracers 11C-choline and 18F-FLT of tumors and reference tissues were examined relative to the clinical standard, 18F-FDG. Tracer biodistribution of various organs was measured by gamma-counting after the last PET scan and compared to the in vivo PET/MR 18F-FDG uptake. Increased tracer uptake was found 2 months postinfection in primary tumors with 18F-FDG and 11C-choline, whereas 18F-FLT failed to detect the tumors at all measured time points. Our data show that the PET tracer 18F-FDG is superior for imaging papillomavirus-induced tumors in rabbits compared to 11C-choline and 18F-FLT. However, 11C-choline imaging, which has previously been applied to detect various tumor entities in patients, appears to be an alternative to 18F-FDG.

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

    Shozo Yamashita

    2015-07-01

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

  7. Importance of Defect Detectability in Positron Emission Tomography Imaging of Abdominal Lesions

    Yamashita, Shozo; Yokoyama, Kunihiko; Onoguchi, Masahisa; Yamamoto, Haruki; Nakaichi, Tetsu; Tsuji, Shiro; Nakajima, Kenichi

    2015-01-01

    Objective(s): This study was designed to assess defect detectability in positron emission tomography (PET) imaging of abdominal lesions. Methods: A National Electrical Manufactures Association International Electrotechnical Commission phantom was used. The simulated abdominal lesion was scanned for 10 min using dynamic list-mode acquisition method. Images, acquired with scan duration of 1-10 min, were reconstructed using VUE point HD and a 4.7 mm full-width at half-maximum (FWHM) Gaussian filter. Iteration-subset combinations of 2-16 and 2-32 were used. Visual and physical analyses were performed using the acquired images. To sequentially evaluate defect detectability in clinical settings, we examined two middle-aged male subjects. One had a liver cyst (approximately 10 mm in diameter) and the other suffered from pancreatic cancer with an inner defect region (approximately 9 mm in diameter). Results: In the phantom study, at least 6 and 3 min acquisition durations were required to visualize 10 and 13 mm defect spheres, respectively. On the other hand, spheres with diameters ≥17 mm could be detected even if the acquisition duration was only 1 min. The visual scores were significantly correlated with background (BG) variability. In clinical settings, the liver cyst could be slightly visualized with an acquisition duration of 6 min, although image quality was suboptimal. For pancreatic cancer, the acquisition duration of 3 min was insufficient to clearly describe the defect region. Conclusion: The improvement of BG variability is the most important factor for enhancing lesion detection. Our clinical scan duration (3 min/bed) may not be suitable for the detection of small lesions or accurate tumor delineation since an acquisition duration of at least 6 min is required to visualize 10 mm lesions, regardless of reconstruction parameters. Improvements in defect detectability are important for radiation treatment planning and accurate PET-based diagnosis. PMID:27408887

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

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

    2002-10-01

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

  9. Localized fetomaternal hyperglycemia: spatial and kinetic definition by positron emission tomography.

    Jianrong Yao

    Full Text Available BACKGROUND: Complex but common maternal diseases such as diabetes and obesity contribute to adverse fetal outcomes. Understanding of the mechanisms involved is hampered by difficulty in isolating individual elements of complex maternal states in vivo. We approached this problem in the context of maternal diabetes and sought an approach to expose the developing fetus in vivo to isolated hyperglycemia in the pregnant rat. METHODOLOGY AND PRINCIPAL FINDINGS: We hypothesized that glucose infused into the arterial supply of one uterine horn would more highly expose fetuses in the ipsilateral versus contralateral uterine horn. To test this, the glucose tracer [18F]fluorodeoxyglucose (FDG was infused via the left uterine artery. Regional glucose uptake into maternal tissues and fetuses was quantified using positron emission tomography (PET. Upon infusion, FDG accumulation began in the left-sided placentae, subsequently spreading to the fetuses. Over two hours after completion of the infusion, FDG accumulation was significantly greater in left compared to right uterine horn fetuses, favoring the left by 1.9+/-0.1 and 2.8+/-0.3 fold under fasted and hyperinsulinemic conditions (p<10(-11 n=32-35 and p<10(-12 n=27-45 respectively. By contrast, centrally administered [3H]-2-deoxyglucose accumulated equally between the fetuses of the two uterine horns. Induction of significant hyperglycemia (10(3 mg/dL localized to the left uterine artery was sustained for at least 48 hours while maternal euglycemia was maintained. CONCLUSIONS AND SIGNIFICANCE: This approach exposes selected fetuses to localized hyperglycemia in vivo, minimizing exposure of the mother and thus secondary effects. Additionally, a set of less exposed internal control fetuses are maintained for comparison, allowing direct study of the in vivo fetal effects of isolated hyperglycemia. Broadly, this approach can be extended to study a variety of maternal-sided perturbations suspected to directly

  10. The Silicon Photomultiplier for application to high-resolution Positron Emission Tomography

    Herbert, D. J.; Moehrs, S.; D'Ascenzo, N.; Belcari, N.; Del Guerra, A.; Morsani, F.; Saveliev, V.

    2007-04-01

    Positron Emission Tomography (PET) for small animal studies requires high-resolution gamma cameras with high sensitivity. Traditionally, inorganic scintillators are used and, in recent times, coupled to position sensitive PMTs to achieve a higher resolution. Such PSPMTs are costly, operated at high voltage and have a relatively low packing fraction. However, their advantage, compared to current solid state photodetectors, is their high signal-to-noise ratio. The Silicon Photomultiplier (SiPM) is a silicon diode detector that shows great promise as a photodetector for scintillators and hence application in nuclear medicine imaging applications. The microcell MRS (Metal-Resistor-Semiconductor) structure of the SiPM leads to a self-quenching, Geiger-mode avalanche photodiode (GAPD), that produces a large gain (5×105) at low bias voltage (50 V) and proportional output for moderate photon flux. Such a compact silicon detector, with a performance similar to a PMT, is obviously well disposed to being developed into a close-packed array in order to have a position-sensitive detection surface. We propose a miniature, high-resolution camera for a small-animal PET imaging system that is based on such an array of SiPM. The design is based upon the classic Anger camera principle; each detector module consists of a continuous slab of scintillator, viewed by a matrix of SiPM. A detector head of 4×4 cm2 in area is proposed, constructed from three such modules of the continuous camera described above. The stacked layers would give the system intrinsic depth of interaction (DOI) information. A summary of measured SiPM performance and results of a simulation of the proposed camera, using the Monte Carlo package GEANT4, are presented. It is shown that using three layers of 5 mm thick LSO, gives an efficiency of 68% with maximum count rates in the front layers. Intrinsic spatial resolution of system.

  11. Radiation detector developments in medical applications: inorganic scintillators in positron emission tomography.

    van Eijk, Carel W E

    2008-01-01

    In recent years, a number of new gamma-ray scintillators are commercially available. These scintillators are either derived from known scintillators, e.g. Lu1-xYxAlO3: Ce (LuYAP) from LuAlO3:Ce and Lu(2(1-x))Y2xSiO5:Ce (LYSO) from Lu2SiO5:Ce or are the result of new discoveries, e.g. LaCl3:Ce and LaBr3:Ce. The first two materials are primarily of interest because of the relatively high detection efficiency and fast response; LYSO has found application in time-of-flight (TOF) positron-emission tomography (TOF PET) and the LuYAP-LYSO combination is used in small-animal PET. The halide scintillators have an excellent energy resolution of approximately 3% at 662 keV and they have a relatively high light yield. LaBr3:Ce is being studied for application in TOF PET. At the same time, the search for and research on new scintillator materials are going on. For example, LuI3:Ce is a new material with a very high light yield (approximately 90,000 photons MeV(-1)). Other examples of new materials are (C6H13NH3)2PbI4 and (C3H7NH3)2PbBr4, organic-inorganic hybrid compounds, of which the former has a very fast sub-nanosecond response. The new scintillators show great promise for new developments in medical applications, in particular, for PET systems.

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

    Ji Eun Lee; Jae Young Jang; Soung Won Jeong; Sae Hwan Lee; Sang Gyune Kim; Sang-Woo Cha; Young Seok Kim

    2012-01-01

    AIM:To evaluated the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan in diagnosis of hepatocellular carcinoma (HCC) and extrahepatic metastases.METHODS:A total of 138 patients with HCC who had both conventional imaging modalities and 18F-FDG PET/CT scan done between November 2006 and March 2011 were enrolled.Diagnostic value of each imaging modality for detection of extrahepatic metastases was evaluated.Clinical factors and tumor characteristics including PET imaging were analyzed as indicative factors for metastases by univariate and multivariate methods.RESULTS:The accuracy of chest CT was significantly superior compared with the accuracy of PET imaging for detecting lung metastases.The detection rate of metastatic pulmonary nodule ≥ 1 cm was 12/13(92.3%),when < 1 cm was 2/10 (20%) in PET imaging.The accuracy of PET imaging was significantly superior compared with the accuracy of bone scan for detecting bone metastases.In multivariate analysis,increased tumor size (≥ 5 cm) (P =0.042) and increased average standardized uptake value (SUV)uptake (P =0.028) were predictive factors for extrahepatic metastases.Isometabolic HCC in PET imaging was inversely correlated in multivariate analysis (P =0.035).According to the receiver operating characteristic curve,the optimal cutoff of average SUV to predict extrahepatic metastases was 3.4.CONCLUSION:18F-FDG PET/CT scan is invaluable for detection of lung metastases larger than 1 cm and bone metastases.Primary HCC having larger than 5 cm and increased average SUV uptake more than 3.4should be considered for extrahepatic metastases.

  13. PETPVC: a toolbox for performing partial volume correction techniques in positron emission tomography

    Thomas, Benjamin A.; Cuplov, Vesna; Bousse, Alexandre; Mendes, Adriana; Thielemans, Kris; Hutton, Brian F.; Erlandsson, Kjell

    2016-11-01

    Positron emission tomography (PET) images are degraded by a phenomenon known as the partial volume effect (PVE). Approaches have been developed to reduce PVEs, typically through the utilisation of structural information provided by other imaging modalities such as MRI or CT. These methods, known as partial volume correction (PVC) techniques, reduce PVEs by compensating for the effects of the scanner resolution, thereby improving the quantitative accuracy. The PETPVC toolbox described in this paper comprises a suite of methods, both classic and more recent approaches, for the purposes of applying PVC to PET data. Eight core PVC techniques are available. These core methods can be combined to create a total of 22 different PVC techniques. Simulated brain PET data are used to demonstrate the utility of toolbox in idealised conditions, the effects of applying PVC with mismatched point-spread function (PSF) estimates and the potential of novel hybrid PVC methods to improve the quantification of lesions. All anatomy-based PVC techniques achieve complete recovery of the PET signal in cortical grey matter (GM) when performed in idealised conditions. Applying deconvolution-based approaches results in incomplete recovery due to premature termination of the iterative process. PVC techniques are sensitive to PSF mismatch, causing a bias of up to 16.7% in GM recovery when over-estimating the PSF by 3 mm. The recovery of both GM and a simulated lesion was improved by combining two PVC techniques together. The PETPVC toolbox has been written in C++, supports Windows, Mac and Linux operating systems, is open-source and publicly available.

  14. Utility of positron emission tomography for tumour surveillance in children with neurofibromatosis type 1

    Moharir, Mahendranath [Hospital for Sick Children, Division of Neurology, Ontario (Canada); London, Kevin [Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney (Australia); Howman-Giles, Robert [University of Sydney, Discipline of Imaging, Faculty of Medicine, Sydney (Australia); North, Kathryn [Children' s Hospital at Westmead, Institute for Neuroscience and Muscle Research, Sydney, NSW (Australia)

    2010-07-15

    There is little consensus regarding optimal surveillance of optic pathway glioma (OPG) and plexiform neurofibroma (PNF) in childhood neurofibromatosis type 1 (NF1). {sup 18}F-2-Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography and computed tomography (PET/CT) is employed in the surveillance of adult PNFs; but its utility has neither been specifically studied in children with PNFs nor in children with OPG. Review of PET/CT studies was performed in NF1 children with OPG or PNF. FDG-avidity of tumours was semi-quantitatively analysed and graded by calculating the maximum standardised uptake value (SUV{sub max}) [grade 1: <3 (low), grade 2: >3-<4 (intermediate), grade 3: >4 (intense)]. Eighteen children (ten girls; median age: 8.5-years) had PET/CT. Nineteen OPGs were imaged. The SUV{sub max} could be measured in 16. Ten were grade 1 and three each were grade 2 and grade 3. FDG-avidity reduced from grade 3 to grade 1 in two symptomatic OPGs following chemotherapy and this was associated with clinical improvement. PET/CT diagnosed symptomatic OPGs with a sensitivity of 0.625 [95% confidence interval (CI): 0.259-0.897] and specificity of 0.875 (95% CI: 0.466-0.993). Sixteen PNFs were imaged. Twelve were grade 1 and two each were grade 2 and grade 3. The two grade 3 PNFs were confirmed malignant peripheral nerve sheath tumours. PET/CT diagnosed malignant transformation with a sensitivity of 1.0 (95% CI: 0.197-1.0) and specificity of 0.857 (95% CI: 0.561-0.974). PET/CT may contribute useful information to the surveillance of OPG in childhood NF1 - particularly to identify progressive, symptomatic tumours. As in adults, PET/CT is useful for the detection of malignant transformation in PNFs in children with NF1. (orig.)

  15. Pitfalls in Positron Emission Tomography/Computed Tomography Imaging: Causes and Their Classifications

    Tian-ran Li; Jia-he Tian; Hui Wang; Zi-qian Chen; Chun-lei Zhao

    2009-01-01

    Objective To describe the pitfalls in positron emission tomography/computed tomography (PET/CT) imaging and classify them according to the principles of their generation. Methods We summarized retrospectively the 18F-fluorodeoxyglucose (FDP) PET/CT imaging pitfalls through reviewing the PET/CT images of 872 patients. The pitfalls were divided into artifacts and infrequent physiological uptake, and the artifacts were further classified according to their causes. Meanwhile, we calculated the incidences of various pitfalls. Whether the PET/CT pitfalls influenced the diagnostic decision was analyzed. The appearances of pitfalls in PET were also described. Results Pitfalls could be found in PET/CT images of 684 (78.4%) patients. Artifacts were found in 664 (76.15%) patients, and could be classified into self-factor artifacts and equipment- or technology- related artifacts. Among self-factor artifacts, respiratory motion (57.5%), postprandial or hyperglycemia artifacts (2.41%), and metal or high density matter artifacts (1.38%) were frequent. As for equipment- or technology-related factors, injection point outleakage or radiotracer contamination (13.88%) and truncation artifacts (1.83%) were most common ones. Infrequent physiological FDG uptakes, including fatty uptake, endometrial uptake, and bilateral breast feeding period uptake, were found in 20 (2.29%) patients. Among all pitfalls, the artifacts in 92 (13.4%) patients and infrequent physiological uptakes in 6 (0.88%) patients affected the diagnostic results. Artifact images in PET could be described as hot or cold area and the images of infrequent physiological uptake were always shown as hot area. Conclusions The incidence of pitfall in PET/CT imaging was high and the causes of pitfalls are various. Among all causes that artifacts generated, respiratory motion is the most common. Some pitfalls may disturb clinical physicians' decision, so it is important to recognize artifacts and physiological uptake, and

  16. Brain glucose utilization in systemic lupus erythematosus with neuropsychiatric symptoms: a controlled positron emission tomography study

    Otte, A. [Institute of Nuclear Medicine, University Hospital, Basel (Switzerland)]|[Department of Nuclear Medicine, University Hospital Freiburg (Germany); Weiner, S.M. [Department of Rheumatology and Immunology, University Hospital Freiburg (Germany); Peter, H.H. [Department of Rheumatology and Immunology, University Hospital Freiburg (Germany); Mueller-Brand, J. [Institute of Nuclear Medicine, University Hospital, Basel (Switzerland); Goetze, M. [Institute of Nuclear Medicine, University Hospital, Basel (Switzerland); Moser, E. [Department of Nuclear Medicine, University Hospital Freiburg (Germany); Gutfleisch, J. [Department of Rheumatology and Immunology, University Hospital Freiburg (Germany); Hoegerle, S. [Department of Nuclear Medicine, University Hospital Freiburg (Germany); Juengling, F.D. [Department of Nuclear Medicine, University Hospital Freiburg (Germany); Nitzsche, E.U. [Department of Nuclear Medicine, University Hospital Freiburg (Germany)

    1997-07-01

    In contrast to morphological imaging [such as magnetic resonance imaging (MRI) or computed tomography], functional imaging may be of advantage in the detection of brain abnormalities in cases of neuropsychiatric systemic lupus erythematosus (SLE). Therefore, we studied 13 patients (aged 40{+-}14 years, 11 female, 2 male) with neuropsychiatric SLE who met four of the American Rheumatism Association criteria for the classification of SLE. Ten clinically and neurologically healthy volunteers served as controls (aged 40{+-}12 years, 5 female, 5 male). Both groups were investigated using fluorine-18-labelled fluorodeoxyglucose brain positron emission tomography (PET) and cranial MRI. The normal controls and 11 of the 13 patients showed normal MRI scans. However, PET scan was abnormal in all 13 SLE patients. Significant group-to-group differences in the glucose metabolic index (GMI=region of interest uptake/global uptake at the level of the basal ganglia and thalamus) were found in the parieto-occipital region on both sides: the GMI of the parieto-occipital region on the right side was 0.922{+-}0.045 in patients and 1.066{+-}0.081 in controls (P<0.0001, Mann Whitney U test), while on the left side it was 0.892{+-}0.060 in patients and 1.034{+-}0.051 in controls (P=0.0002). Parieto-occipital hypometabolism is a conspicuous finding in mainly MRI-negative neuropsychiatric SLE. As the parieto-occipital region is located at the boundary of blood supply of all three major arteries, it could be the most vulnerable zone of the cerebrum and may be affected at an early stage of the cerebrovascular disease. (orig.). With 1 fig., 1 tab.

  17. Molecular imaging of atherosclerotic lesions by positron emission tomography - can it meet the expectations?

    Brammen, Lindsay; Steiner, Sabine; Berent, Robert; Sinzinger, Helmut

    2016-01-01

    Early non-invasive imaging of atherosclerosis and in particular the detection of lesions at risk with high specificity could significantly affect cardiovascular morbidity and mortality. Conventional nuclear medicine approaches, in particular using autologous radiolabeled lipoproteins, can be related to histopathological findings; however, they fail to identify lesions at risk. Positron emission tomography (PET) tracers with much better physical properties have been examined, the most detailed information being available for F-18-deoxyglucose (FDG) and F-18-sodium fluoride (NaF). These two approaches are sensitive to different biochemical mechanisms, i.e. inflammation and microcalcification. Initial enthusiasm, in particular for F-18-FDG, has disappeared, although for F-18-NaF there is some hope, but this is not a breakthrough. No tracer is available so far that is able to identify a specific characteristic of a lesion prone to rupture. Other PET tracers in the pipeline have been examined, mainly in experimental models and only a few in patients, but they failed to contribute significantly to early lesion discovery and do not support great expectations. The key question is: Do we understand what we see? Moreover, methodological problems, a lack of standardization of imaging protocols and aspects of quantification provide a wide range for potential future improvements. While monitoring a therapeutic intervention seems to be possible for both F-18-FDG and F-18-NaF, highly specific early identification of lesions at risk by PET imaging is still far away. As of today, PET is not ready for routine clinical judgment of atherosclerotic lesions at risk to rupture. Even if all these problems can be solved, radiation exposure will still remain a concern, in particular for repeated studies.

  18. Detection of occult disease in breast cancer using fluorodeoxyglucose camera-based positron emission tomography.

    Pecking, A P; Mechelany-Corone, C; Bertrand-Kermorgant, F; Alberini, J L; Floiras, J L; Goupil, A; Pichon, M F

    2001-10-01

    An isolated increase of blood tumor marker CA 15.3 in breast cancer is considered a sensitive indicator for occult metastatic disease but by itself is not sufficient for initiating therapeutic intervention. We investigated the potential of camera-based positron emission tomography (PET) imaging using [18F]-fluorodeoxyglucose (FDG) to detect clinically occult recurrences in 132 female patients (age, 35-69 years) treated for breast cancer, all presenting with an isolated increase in blood tumor marker CA 15.3 without any other evidence of metastatic disease. FDG results were correlated to pathology results or to a sequentially guided conventional imaging method. One hundred nineteen patients were eligible for correlations. Positive FDG scans were obtained for 106 patients, including 89 with a single lesion and 17 with 2 or more lesion. There were 92 true-positive and 14 false-positive cases, 10 of which became true positive within 1 year. Among the 13 negative cases, 7 were false negative and 6 were true negative. Camera-based PET using FDG has successfully identified clinically occult disease with an overall sensitivity of 93.6% and a positive predictive value of 96.2%. The smallest detected size was 6 mm for a lymph node metastasis (tumor to nontumor ratio, 4:2). FDG camera-based PET localized tumors in 85.7% of cases suspected for clinically occult metastatic disease on the basis of a significant increase in blood tumor marker. A positive FDG scan associated with an elevated CA 15.3 level is most consistent with metastatic relapse of breast cancer.

  19. Use of fluorine-18 fluorodeoxyglucose positron emission tomography in the detection of thymoma: a preliminary report

    Liu Renshyan [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China)]|[National Def. Medical Center, Taipei (Taiwan, Province of China); Yeh Shinhwa [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Huang Minhsiung [Div. of Thoracic Surgery, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Wang Liangshun [Div. of Thoracic Surgery, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Chu Leeshing [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China)]|[National Def. Medical Center, Taipei (Taiwan, Province of China); Chang Chenpei [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Chu Yumkung [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Wu Lingchi [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China)

    1995-12-01

    This study aimed to analyse the uptake patterns of fluorine-18 fluorodeoxyglucose (FDG) in thymomas of different stages. FDG positron emission tomography (PET) scan was performed in 12 patients suspected of having thymoma and in nine controls. Qualitative visual interpretation was used to detect the foci with FDG uptake higher than that of normal mediastinum. Tumour/lung ratio (TLR) was calculated from the counts of ROIs over the mass and over comparable normal lung tissue in thymoma patients. Mediastinum/lung ratio (MLR) was calculated from the counts of ROIs over the anterior mediastinum and lung in controls. The PET scan patterns of distribution of foci with FDG uptake and TLRs were correlated with the computed tomography (CT) of magnetic resonance imaging (MRI) findings, and staging of the thymomas. Thymectomy was performed in ten patients and thoracoscopy was done in two patients. The results revealed ten thymomas (two stage I tumours, two stage II, four stage III and two stage IV, according to the Masaoka classification), and two cases of thymic hyperplasia associated with myasthenia gravis. Myasthenia gravis was also noted in four thymoma patients. FDG studies showed (a) diffuse uptake in the widened anterior mediastinum in patients with thymic hyperplasia, (b) confined focal FDG uptake in the non-invasive or less invasive, stage I and II thymomas, and (c) multiple discrete foci of FDG uptake in the mediastinum and thoraci structures in stage III and IV advanced invasive thymomas. The thymomas had the highest TLRs, followed by the TLRs of thymic hyperplasia and the MLRs of control subjects. No significant difference was found between thymomas in different stages or between thymomas with and thymomas without myasthenia gravis. In comparison with CT and/or MRI, FDG/PET detected more lesions in patients with invasive thymomas and downgraded the staging of thymoma in four patients. (orig./MG)

  20. Cerebral blood flow and metabolism for Broca's aphasia using positron emission tomography

    Kato, Toshiaki

    1987-12-01

    A total of 11 patients with Broca's aphasia (BA) underwent positron emission tomography (PET) with the purpose of investigating the responsible region and the symptomatic flow and metabolism thresholds for BA. Computed tomography (CT) was concurrently performed. In the group of 3 patients undergoing PET with C-11 glucose, both PET and CT provided abnormal findings in the region that is thought to be responsible for BA (Broca's area), including the cortex and subcortex in the anterior region to Sylvian fissure. The Broca's area in the remaining one was shown as low C-11 accumulation area on PET and as isodensity on CT. The second group, consisting of 8 BA patients and 30 control patients without BA, underwent PET using O-15 steady method. PET showed reduction of regional cerebral blood flow (rCBF) and oxygen metabolic rate (rCMRO/sub 2/) in the Broca's area in all BA patients. Computed tomography showed abnormal low density in the Broca's area in 3 patients, and abnormal findings in the basal ganglionic region and subcortex without evidence for abnormal low density in the Broca's area in the other 5 patients. Comparison of rCBF and rCMRO/sub 2/ in BA patients with those in control patients may show the symptomatic thresholds to be 20 - 27 ml100 gmin for rCBF and 2.0 ml100 gmin for rCMRO/sub 2/. (Namekawa, K.).

  1. Whole-body energy mapping under physical exercise using positron emission tomography.

    Iemitsu, M; Itoh, M; Fujimoto, T; Tashiro, M; Nagatomi, R; Ohmori, H; Ishii, K

    2000-12-01

    We attempted to visualize dynamic adjustment of glucose utilization in humans in the whole-body organs during physical exercise by using three-dimensional positron emission tomography (3D-PET) and [18F]-2-fluoro-deoxy-glucose (FDG). Twelve healthy male volunteers collaborated on the study; six subjects were assigned to the resting control group (C) and the other six to the running group (E). Group E subjects performed running on a flat road for 35 min. After 15 min of running, subjects injected FDG and kept on running thereafter for another 20 min. Group C subjects sat on a comfortable chair in a quiet room for 35 min after the injection of FDG. After scanning by PET, the regions of interest (ROIs) were manually set on brain, heart, thorax, abdomen, lower extremities, and the rest of the body on the corresponding transaxial images. The uptake of FDG in each region was evaluated as the % fraction of FDG accumulation relative to the total amount of whole-body accumulation. The results revealed increase of FDG uptake after running in the lower leg muscles from 24.6 +/- 9.5% to 43.1 +/- 4.7% and in the heart from 2.3 +/- 0.4% to 2.8 +/- 0.6%. The differences were significant (P body. FDG uptake in the abdominal region reduced from 37.3 +/- 7.2% to 19.7 +/- 4.9%. However, FDG uptake in the brain remained stable, i.e., 11.9 +/- 2.8% at rest and 10.3 +/- 2.5% after exercise. Thus, 3D-PET is a tool to visualize the dynamic adjustment of energy consumption during physical exercise in humans.

  2. Imaging glucose metabolism in perfluorocarbon-perfused hepatocyte bioreactors using positron emission tomography.

    Nieuwoudt, Martin; Wiggett, Scholtz; Malfeld, Susan; van der Merwe, Schalk W

    2009-01-01

    In vitro hepatocyte bioreactor functionality depends particularly on maintaining appropriate oxygen levels and exposure to nonparenchymal cells. An attractive solution without immunological consequences to the patient is incorporating a perfluorocarbon oxygen carrier in the circulating medium and co-culturing hepatocytes with stellate cells. Since bioreactors are normally sealed sterile units, demonstrating metabolic functionality is hindered by limited access to the cells after their aggregation in the matrix. A novel possibility is to use positron emission tomography (PET) to image cellular radioactive glucose uptake under O(2)-limited conditions. In this study, primary cell isolation procedures were carried out on eight pigs. Pairs of cell-seeded and cell-free (control) bioreactors with and without perfluorocarbon were cultured under identical conditions and were oxygenated using hypoxic (5% O(2)) and ambient (20% O(2)) gas mixes. Sixteen PET scans were conducted 24 h after cell isolation, the same timescale as that involved in treating a liver failure patient with a primary-cell bioreactor. In all cases, cell-seeded bioreactors without perfluorocarbon were more radioactive, i.e., were more glycolytic, than those with perfluorocarbon. This difference was significant in the hypoxic pair of bioreactors but not in the ambient pair of bioreactors. Additionally, in the same hypoxic bioreactors, circulating extracellular steady-state glucose levels were significantly lower and lactate levels were higher than those in the ambient bioreactors. Similar findings have been made in other in vitro hepatocyte studies investigating the effects of perfluorocarbons. PET is attractive for studying in situ O(2)-dependent bioreactor metabolism because of its visual and numerically quantifiable outputs. Longer-term metabolic studies (e.g., 5-10 days) investigating the effect of perfluorocarbon on bioreactor longevity will complement these findings in the future.

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

    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.

  4. Motion management in positron emission tomography/computed tomography for radiation treatment planning.

    Bettinardi, Valentino; Picchio, Maria; Di Muzio, Nadia; Gilardi, Maria Carla

    2012-09-01

    Hybrid positron emission tomography (PET)/computed tomography (CT) scanners combine, in a unique gantry, 2 of the most important diagnostic imaging systems, a CT and a PET tomograph, enabling anatomical (CT) and functional (PET) studies to be performed in a single study session. Furthermore, as the 2 scanners use the same spatial coordinate system, the reconstructed CT and PET images are spatially co-registered, allowing an accurate localization of the functional signal over the corresponding anatomical structure. This peculiarity of the hybrid PET/CT system results in improved tumor characterization for oncological applications, and more recently, it was found to be also useful for target volume definition (TVD) and treatment planning in radiotherapy (RT) applications. In fact, the use of combined PET/CT information has been shown to improve the RT treatment plan when compared with that obtained by a CT alone. A limiting factor to the accuracy of TVD by PET/CT is organ and tumor motion, which is mainly due to patient respiration. In fact, respiratory motion has a degrading effect on PET/CT image quality, and this is also critical for TVD, as it can lead to possible tumor missing or undertreatment. Thus, the management of respiratory motion is becoming an increasingly essential component in RT treatment planning; indeed, it has been recognized that the use of personalized motion information can improve TVD and, consequently, permit increased tumor dosage while sparing surrounding healthy tissues and organs at risk. This review describes the methods used for motion management in PET/CT for radiation treatment planning. The article covers the following: (1) problems caused by organ and lesion motion owing to respiration, and the artifacts generated on CT, PET, and PET/CT images; (2) data acquisition and processing techniques used to manage respiratory motion in PET/CT studies; and (3) the use of personalized motion information for TVD and radiation treatment planning.

  5. Clinical utility of 11C-flumazenil positron emission tomography in intractable temporal lobe epilepsy

    Padma M

    2004-10-01

    Full Text Available BACKGROUND: 11C-flumazenil (FMZ positron emission tomography (PET is a new entrant into the armamentarium for pre-surgical evaluation of patients with intractable temporal lobe epilepsy (TLE. AIMS: To analyze the clinical utility of FMZ PET to detect lesional and remote cortical areas of abnormal benzodiazepine receptor binding in relation to magnetic resonance imaging (MRI, 2-Deoxy-2 [18F] fluoro-D-glucose, (18F FDG PET, electrophysiological findings and semiology of epilepsy in patients with intractable TLE. MATERIALS AND METHODS: Patients underwent a high resolution MRI, prolonged Video-EEG monitoring before 18F FDG and 11C FMZ PET studies. Regional cortical FMZ PET abnormalities were defined on co-registered PET images using an objective method based on definition of areas of abnormal asymmetry (asymmetry index {AI}>10%. SETTINGS AND DESIGN: Prospective. STATISTICAL ANALYSIS: Student′s "t" test. RESULTS: Twenty patients (Mean age: 35.2 years [20-51]; M:F=12:8 completed the study. Mean age at seizure onset was 10.3 years (birth-38 years; mean duration, 23.9 years (6-50 years. Concordance with the MRI lesion was seen in 10 patients (nine with hippocampal sclerosis and one with tuberous sclerosis. In the other 10, with either normal or ambiguous MRI findings, FMZ and FDG uptake were abnormal in all, concordant with the electrophysiological localization of the epileptic foci. Remote FMZ PET abnormalities (n=18 were associated with early age of seizure onset (P=0.005 and long duration of epilepsy (P=0.01. CONCLUSIONS: FMZ-binding asymmetry is a sensitive method to detect regions of epileptic foci in patients with intractable TLE.

  6. Positron emission tomography thyroid incidentaloma: Is it different in Indian subcontinent?

    R Vaish

    2016-01-01

    Full Text Available Background: Positron emission tomography (PET forms an integral part in work-up and follow-up of various malignancies. With the increased use of PET in oncology, finding of an incidental focal thyroid uptake (incidentaloma is not unusual and presents a diagnostic challenge. Aim: The aim of the following study is to evaluate the frequency and radio-pathologic correlation of focal 18-fluoro deoxyglucose uptake (FDG on PET within the thyroid from a large series. Materials and Methods: Retrospective review of 37,000 consecutive patients who underwent FDG-PET at tertiary cancer center in India. Radiological, pathological, PET scan and follow-up details were evaluated. Statistical analyzes were carried out using Mann Whitney test and Pearson correlation. Results: Abnormal thyroid uptake was seen in 78 (0.2% patients. Nearly 61 (0.16% scans had focal and 17 (0.04% had diffuse FDG uptake. A total of 57 patients with focal uptake were available for further evaluation. No further evaluation was done in 24 (42.1% patients who had advanced index malignancy. Of the remaining 33 patients 26 were benign and seven were a cause for concern (four primary thyroid cancers, one follicular neoplasm with hurthle cell change and two metastatic cancers. There was no significant correlation in Standardized uptake value (SUV max of benign and malignant lesion (P = 0.5 on Mann Whitney or size (r = 0.087 Pearson correlation co-efficient P= 0.667. Conclusion: Incidence of PET incidentaloma is low in this large cohort of Indian patients. Nearly 27% of focal incidentaloma were malignant. There was no correlation between the SUVmax, size and malignancy.

  7. Fluorodeoxyglucose positron emission tomography in the initial staging of germ cell tumours

    Hain, S.F.; O' Doherty, M.J. [Clinical PET Centre, Guy' s and St Thomas' Hospitals, London (United Kingdom); Timothy, A.R.; Leslie, M.D.; Partridge, S.E. [Dept. of Clinical Oncology, Guy' s and St Thomas' Hospitals, London (United Kingdom); Huddart, R.A. [Dept. of Radiotherapy and Oncology, Royal Marsden, Surrey (United Kingdom)

    2000-05-01

    Testicular cancer is a rare tumour with the potential for cure at diagnosis. It is important, however, to identify those patients with metastases at presentation so as to ensure that the optimum treatment strategy is employed. Many criteria have been used to try to place patients into high- or low-risk groups, with variable success. Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has the potential to identify active disease and thereby influence further management. Here we report on a retrospective study of the use of FDG-PET in the detection of metastatic testicular carcinoma at diagnosis. Thirty-one patients [13 with seminoma and 18 with non-seminomatous germ cell tumours (13 teratomas, 5 mixed)] were staged by FDG-PET scanning. The imaging was performed using a Siemens ECAT 951 scanner. All results were assessed on the basis of histology or clinical follow-up. FDG-PET scan identified metastatic disease in ten and was negative in 16; there were no false-positives and five false-negatives. There were six patients in whom FDG-PET was negative and computed tomography was regarded as suspicious but follow-up was inconclusive. The positive predictive value was 100%. The negative predictive value was 76% or 91%, depending on whether the aforementioned six cases were regarded as true-negatives or false-negatives. It may be concluded that FDG-PET is capable of detecting metastatic disease at diagnosis that is not identified by other imaging techniques. These preliminary results are sufficient to suggest that a large prospective study should be performed to evaluate the role of FDG-PET in primary staging of disease. (orig.)

  8. A quantitative model for the in vivo assessment of drug binding sites with positron emission tomography

    Mintun, M.A.; Raichle, M.E.; Kilbourn, M.R.; Wooten, G.F.; Welch, M.J.

    1984-03-01

    We propose an in vivo method for use with positron emission tomography (PET) that results in a quantitative characterization of neuroleptic binding sites using radiolabeled spiperone. The data are analyzed using a mathematical model that describes transport, nonspecific binding, and specific binding in the brain. The model demonstrates that the receptor quantities Bmax (i.e., the number of binding sites) and KD-1 (i.e., the binding affinity) are not separably ascertainable with tracer methodology in human subjects. We have, therefore, introduced a new term, the binding potential, equivalent to the product BmaxKD-1, which reflects the capacity of a given tissue, or region of a tissue, for ligand-binding site interaction. The procedure for obtaining these measurements is illustrated with data from sequential PET scans of baboons after intravenous injection of carrier-added (18F)spiperone. From these data we estimate the brain tissue nonspecific binding of spiperone to be in the range of 94.2 to 95.3%, and the regional brain spiperone permeability (measured as the permeability-surface area product) to be in the range of 0.025 to 0.036 cm3/(s X ml). The binding potential of the striatum ranged from 17.4 to 21.6; these in vivo estimates compare favorably to in vitro values in the literature. To our knowledge this represents the first direct evidence that PET can be used to characterize quantitatively, locally and in vivo, drug binding sites in brain. The ability to make such measurements with PET should permit the detailed investigation of diseases thought to result from disorders of receptor function.

  9. Role of (18F) 2-fluoro-2-deoxyglucose positron emission tomography in upper gastrointestinal malignancies

    Elizabeth C Smyth; Manish A Shah

    2011-01-01

    The role of whole-body FDG [(18F) 2-fluoro-2-deoxyglucose] positron emission tomography (PET) scanning as an imaging modality in the management of patients with malignancy has evolved enormously over the past two decades. FDG-PET has demonstrated significant efficacy in the staging, prognostication and detection of occult metastatic disease in malignancies of the gastrointestinal tract, in addition to assessment of the response to cytotoxic chemotherapy in a more timely manner than has traditionally been possible by more conventional imaging tools. The sensitivity and specificity of FDG-PET for the detection and staging of malignancy depend not only on the site and size of the primary tumor and metastases, but also on histological cell type, reflecting underlying disparities in glucose metabolism. The metabolic response to neo-adjuvant chemotherapy or to chemo-radiotherapy in cancers of the gastro-esophageal junction or stomach has been demonstrated in several prospective studies to correlate significantly with both the histological tumor response to treatment and with consequent improvements in overall survival. This may offer a future paradigm of personalized treatment based on the PET response to chemotherapy. FDG-PET has been less successful in efforts to screen for and detect recurrent upper gastrointestinal malignancies, and in the detection of low volume metastatic peritoneal disease. Efforts to improve the accuracy of PET include the use of novel radiotracers such as (18F) FLT (3-deoxy-3-fluorothymidine) or 11C-choline, or fusion PET-CT with concurrent high-resolution computed tomography. This review focuses on the role of FDG-PET scanning in staging and response assessment in malignancies of the upper gastrointestinal tract, specifically gastric, esophageal and pancreas carcinoma.

  10. Positron emission tomography reporter genes and reporter probes: gene and cell therapy applications.

    Yaghoubi, Shahriar S; Campbell, Dean O; Radu, Caius G; Czernin, Johannes

    2012-01-01

    Positron emission tomography (PET) imaging reporter genes (IRGs) and PET reporter probes (PRPs) are amongst the most valuable tools for gene and cell therapy. PET IRGs/PRPs can be used to non-invasively monitor all aspects of the kinetics of therapeutic transgenes and cells in all types of living mammals. This technology is generalizable and can allow long-term kinetics monitoring. In gene therapy, PET IRGs/PRPs can be used for whole-body imaging of therapeutic transgene expression, monitoring variations in the magnitude of transgene expression over time. In cell or cellular gene therapy, PET IRGs/PRPs can be used for whole-body monitoring of therapeutic cell locations, quantity at all locations, survival and proliferation over time and also possibly changes in characteristics or function over time. In this review, we have classified PET IRGs/PRPs into two groups based on the source from which they were derived: human or non-human. This classification addresses the important concern of potential immunogenicity in humans, which is important for expansion of PET IRG imaging in clinical trials. We have then discussed the application of this technology in gene/cell therapy and described its use in these fields, including a summary of using PET IRGs/PRPs in gene and cell therapy clinical trials. This review concludes with a discussion of the future direction of PET IRGs/PRPs and recommends cell and gene therapists collaborate with molecular imaging experts early in their investigations to choose a PET IRG/PRP system suitable for progression into clinical trials.

  11. Positron Emission Tomography Reporter Genes and Reporter Probes: Gene and Cell Therapy Applications

    Shahriar S. Yaghoubi, Dean O. Campbell, Caius G. Radu, Johannes Czernin

    2012-01-01

    Full Text Available Positron emission tomography (PET imaging reporter genes (IRGs and PET reporter probes (PRPs are amongst the most valuable tools for gene and cell therapy. PET IRGs/PRPs can be used to non-invasively monitor all aspects of the kinetics of therapeutic transgenes and cells in all types of living mammals. This technology is generalizable and can allow long-term kinetics monitoring. In gene therapy, PET IRGs/PRPs can be used for whole-body imaging of therapeutic transgene expression, monitoring variations in the magnitude of transgene expression over time. In cell or cellular gene therapy, PET IRGs/PRPs can be used for whole-body monitoring of therapeutic cell locations, quantity at all locations, survival and proliferation over time and also possibly changes in characteristics or function over time. In this review, we have classified PET IRGs/PRPs into two groups based on the source from which they were derived: human or non-human. This classification addresses the important concern of potential immunogenicity in humans, which is important for expansion of PET IRG imaging in clinical trials. We have then discussed the application of this technology in gene/cell therapy and described its use in these fields, including a summary of using PET IRGs/PRPs in gene and cell therapy clinical trials. This review concludes with a discussion of the future direction of PET IRGs/PRPs and recommends cell and gene therapists collaborate with molecular imaging experts early in their investigations to choose a PET IRG/PRP system suitable for progression into clinical trials.

  12. Development of an angled Si-PM-based detector unit for positron emission mammography (PEM) system

    Nakanishi, Kouhei; Yamamoto, Seiichi

    2016-11-01

    Positron emission mammography (PEM) systems have higher sensitivity than clinical whole body PET systems because they have a smaller ring diameter. However, the spatial resolution of PEM systems is not high enough to detect early stage breast cancer. To solve this problem, we developed a silicon photomultiplier (Si-PM) based detector unit for the development of a PEM system. Since a Si-PM's channel is small, Si-PM can resolve small scintillator pixels to improve the spatial resolution. Also Si-PM based detectors have inherently high timing resolution and are able to reduce the random coincidence events by reducing the time window. We used 1.5×1.9×15 mm LGSO scintillation pixels and arranged them in an 8×24 matrix to form scintillator blocks. Four scintillator blocks were optically coupled to Si-PM arrays with an angled light guide to form a detector unit. Since the light guide has angles of 5.625°, we can arrange 64 scintillator blocks in a nearly circular shape (a regular 64-sided polygon) using 16 detector units. We clearly resolved the pixels of the scintillator blocks in a 2-dimensional position histogram where the averages of the peak-to-valley ratios (P/Vs) were 3.7±0.3 and 5.7±0.8 in the transverse and axial directions, respectively. The average energy resolution was 14.2±2.1% full-width at half-maximum (FWHM). By including the temperature dependent gain control electronics, the photo-peak channel shifts were controlled within ±1.5% with the temperature from 23 °C to 28 °C. With these results, in addition to the potential high timing performance of Si-PM based detectors, our developed detector unit is promising for the development of a high-resolution PEM system.

  13. A method for comparing intra-tumoural radioactivity uptake heterogeneity in preclinical positron emission tomography studies

    Grafström, Jonas; Ahlzén, Hanna-Stina [Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm (Sweden); Stone-Elander, Sharon [Department of Clinical Neuroscience, Karolinska Institutet, SE-17176 Stockholm (Sweden); PET Radiochemistry, Neuroradiology Department, Karolinska University Hospital, SE-17176 Stockholm (Sweden)

    2015-09-08

    Non-uniformity influences the interpretation of nuclear medicine based images and consequently their use in treatment planning and monitoring. However, no standardised method for evaluating and ranking heterogeneity exists. Here, we have developed a general algorithm that provides a ranking and a visualisation of the heterogeneity in small animal positron emission tomography (PET) images. The code of the algorithm was written using the Matrix Laboratory software (MATLAB). Parameters known to influence the heterogeneity (distances between deviating peaks, gradients and size compensations) were incorporated into the algorithm. All data matrices were mathematically constructed in the same format with the aim of maintaining overview and control. Histograms visualising the spread and frequency of contributions to the heterogeneity were also generated. The construction of the algorithm was tested using mathematically generated matrices and by varying post-processing parameters. It was subsequently applied in comparisons of radiotracer uptake in preclinical images in human head and neck carcinoma and endothelial and ovarian carcinoma xenografts. Using the developed algorithm, entire tissue volumes could be assessed and gradients could be handled in an indirect manner. Similar-sized volumes could be compared without modifying the algorithm. Analyses of the distribution of different tracers gave results that were generally in accordance with single plane preclinical images, indicating that it could appropriately handle comparisons of targeting vs. non-targeting tracers and also for different target levels. Altering the reconstruction algorithm, pixel size, tumour ROI volumes and lower cut-off limits affected the calculated heterogeneity factors in expected directions but did not reverse conclusions about which tumour was more or less heterogeneous. The algorithm constructed is an objective and potentially user-friendly tool for one-to-one comparisons of heterogeneity in

  14. Development of radiotracers for imaging NR2B subtype NMDA receptors with positron emission tomography; Developpement de radiotraceurs pour la visualisation des recepteurs NMDA de sous-type NR2B par tomographie par emission de positons

    Labas, R

    2007-07-01

    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 ({sup 11}C or {sup 18}F)

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

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

    2012-07-01

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

  16. Brain docosahexaenoic acid [DHA] incorporation and blood flow are increased in chronic alcoholics: a positron emission tomography study corrected for cerebral atrophy.

    John C Umhau

    Full Text Available OBJECTIVE: Chronic alcohol dependence has been associated with disturbed behavior, cerebral atrophy and a low plasma concentration of docosahexaenoic acid (DHA, 22∶6n-3, particularly if liver disease is present. In animal models, excessive alcohol consumption is reported to reduce brain DHA concentration, suggesting disturbed brain DHA metabolism. We hypothesized that brain DHA metabolism also is abnormal in chronic alcoholics. METHODS: We compared 15 non-smoking chronic alcoholics, studied within 7 days of their last drink, with 22 non-smoking healthy controls. Using published neuroimaging methods with positron emission tomography (PET, we measured regional coefficients (K* and rates (J(in of DHA incorporation from plasma into the brain of each group using [1-(11C]DHA, and regional cerebral blood flow (rCBF using [(15O]water. Data were partial volume error corrected for brain atrophy. Plasma unesterified DHA concentration also was quantified. RESULTS: Mean K* for DHA was significantly and widely elevated by 10-20%, and rCBF was elevated by 7%-34%, in alcoholics compared with controls. Unesterified plasma DHA did not differ significantly between groups nor did whole brain J(in, the product of K* and unesterified plasma DHA concentration. DISCUSSION: Significantly higher values of K* for DHA in alcoholics indicate increased brain avidity for DHA, thus a brain DHA metabolic deficit vis-à-vis plasma DHA availability. Higher rCBF in alcoholics suggests increased energy consumption. These changes may reflect a hypermetabolic state related to early alcohol withdrawal, or a general brain metabolic change in chronic alcoholics.

  17. Differential brain processing of audiovisual sexual stimuli in men: comparative positron emission tomography study of the initiation and maintenance of penile erection during sexual arousal.

    Miyagawa, Yasushi; Tsujimura, Akira; Fujita, Kazutoshi; Matsuoka, Yasuhiro; Takahashi, Tohru; Takao, Tetsuya; Takada, Shingo; Matsumiya, Kiyomi; Osaki, Yasuhiro; Takasawa, Masashi; Oku, Naohiko; Hatazawa, Jun; Kaneko, Shigeo; Okuyama, Akihiko

    2007-07-01

    The human male psychosexual cycle consists of four phases: excitation, plateau, orgasm, and resolution. Identification of the specific neural substrates of each phase may provide information regarding the brain's pathophysiology of sexual dysfunction. We previously analyzed regional cerebral blood flow (rCBF) with H(2)15O-positron emission tomography (PET) during the excitation phase (initiation of penile erection) induced by audiovisual sexual stimuli (AVSS) and identified activation of the cerebellar vermis, the bilateral extrastriate cortex, and right orbitofrontal cortex, suggesting a role of cognition/emotion in the excitement phase. In the present study, we analyzed rCBF of the same six healthy volunteers during the plateau phase (maintenance of penile erection) induced by AVSS and compared the results with those of the excitation phase. Penile rigidity was monitored in real time with RigiScan Plus during PET scanning. Images were analyzed by statistical parametric mapping (SPM) software, and rCBF in the amygdala, hypothalamus, anterior cingulate, and insula was measured. During the plateau phase, primary subcortical activation was noted in the right ventral putamen, indicating motivational factors in the sexual response via the limbic reward circuit. A significant increase in rCBF in the left hypothalamus was also observed during the plateau phase. The right anterior cingulate and left insula were specifically activated during the excitation phase but not during the plateau phase. These results indicate a significant role of the ventral putamen and the hypothalamus in the plateau phase and confirm that paralimbic and limbic components of the human brain differentially coordinate the sexual response in a psychosexual phase-dependent manner.

  18. Correlation of PUV and SUV in the extremities while using PEM as a high-resolution positron emission scanner

    Rahim, Sania [The University of Texas MD Anderson Cancer Center, Division of Diagnostic Imaging, Houston, TX (United States); MD Anderson Cancer Center, Houston, TX (United States); Mawlawi, Osama; Taylor, Shree; Millican, Richelle; Swanston, Nancy M.; Rohren, Eric M. [The University of Texas MD Anderson Cancer Center, Division of Diagnostic Imaging, Houston, TX (United States); Fox, Patricia [The University of Texas MD Anderson Cancer Center, Division of Biostatistics, Houston, TX (United States); Brown, J.E. [Yale University Hospital, Department of Radiology, New Haven, CT (United States)

    2014-04-15

    Owing to its unique configuration of two adjustable plate detectors positron emission mammography, or PEM, could theoretically also function as a high-resolution positron emission scanner for the extremities or neck. PEM quantitates its activity via a ''PEM uptake value,'' or PUV, and although its relationship to the standardized uptake value, or SUV, has been demonstrated in the breasts, to our knowledge there are no studies validating PUV in other sites such as the extremities. This was a retrospective chart review of two separate protocols of a total of 15 patients. The patients all had hypermetabolic lesions in the extremities or neck on imaging with PET/CT and were sent after their PET/CT to PEM for further imaging. Owing to the sequential nature of these examinations no additional radiotracer was administered. Spearman's rank order correlation was calculated between the PUVmax obtained from PEM images, and the SUVmax for all. Spearman's rank order correlation for all sites was 0.42, which is not significantly different from 0 (p = 0.13). When neck lesions were excluded from the group, there was a strong and statistically significant correlation between PUVmax and SUVmax, with Spearman's rank correlation of 0.73, and significantly different from 0 (p = 0.0068). The correlation of PUV and SUV in the extremities indicates the potential use of PEM as a semiquantitative, high-resolution positron emission scanner and warrants further investigation, especially in the realms of disease processes that often present in the extremities, such as melanoma, osteomyelitis, and arthritis, as well as playing a role in the imaging of patients with metallic hardware post-limb salvage surgery. (orig.)

  19. High resolution gamma detector for small-animal positron emission tomography

    Ling, Tao

    In this study, the performance of continuous miniature crystal element (cMiCE) detectors with LYSO crystals of different thickness were investigated. Potential designs of a cMiCE small animal positron emission tomography scanner were also evaluated by an analytical simulation approach. The cMiCE detector was proposed as a high sensitivity, low cost alternative to the prevailing discrete crystal detectors. A statistics based positioning (SBP) algorithm was developed to solve the scintillation position estimation problem and proved to be successful on a cMiCE detector with a 4 mm thick crystal. By assuming a Gaussian distribution, the distributions of the photomultiplier signals could be characterized by mean and variance, which are functions of scintillation position. After calibrating the detector on a grid of locations, a 2D table of the mean and variance can be built. The SBP algorithm searches the tables to find the location that maximizes the likelihood between the mean and variance of known positions and the incoming scintillation event. In this work, the performance of the SBP algorithm on cMiCE detectors with thicker crystals (6 and 8 mm) was studied. The stopping power of a cMiCE detector is 40% and 49% for 6 and 8 mm thick crystals respectively. The intrinsic spatial resolution is 1.2 mm and 1.4 mm FWHM for the center and corner sections of a 6 mm thick crystal detector, and 1.3 mm and 1.6 mm for center and corner of an 8 mm thick crystal detector. These results demonstrate that the cMiCE detector is a promising candidate for high resolution, high sensitivity PET applications. A maximum-likelihood (ML) clustering method was developed to empirically separate the experimental data set into two to four subgroups according to the depth-of-interaction of the detected photons. This method enabled us to build 2-DOI lookup tables (LUT) (mean and variance lookup tables for front group and back group). Using the 2-DOI SBP LUTs, the scintillation position and DOI

  20. Assessment of endothelial function and myocardial flow reserve using {sup 15}O-water PET without attenuation correction

    Tuffier, Stephane; Joubert, Michael; Bailliez, Alban [EA 4650, Normandie Universite, Caen (France); Legallois, Damien [EA 4650, Normandie Universite, Caen (France); Caen University Hospital, Department of Cardiology, Caen (France); Belin, Annette [Caen University Hospital, Department of Cardiac Surgery, Caen (France); Redonnet, Michel [Rouen University Hospital, Department of Cardiac Surgery, Rouen (France); Agostini, Denis [EA 4650, Normandie Universite, Caen (France); Caen University Hospital, Department of Nuclear Medicine, Caen (France); Manrique, Alain [EA 4650, Normandie Universite, Caen (France); Caen University Hospital, Department of Nuclear Medicine, Caen (France); Cyceron PET Centre, Caen (France)

    2016-02-15

    Myocardial blood flow (MBF) measurement using positron emission tomography (PET) from the washout rate of {sup 15}O-water is theoretically independent of tissue attenuation. The aim of this study was to evaluate the impact of not using attenuation correction in the assessment of coronary endothelial function and myocardial flow reserve (MFR) using {sup 15}O-water PET. We retrospectively processed 70 consecutive {sup 15}O-water PET examinations obtained at rest and during cold pressor testing (CPT) in patients with dilated cardiomyopathy (n = 58), or at rest and during adenosine infusion in heart transplant recipients (n = 12). Data were reconstructed with attenuation correction (AC) and without attenuation correction (NAC) using filtered backprojection, and MBF was quantified using a single compartmental model. The agreement between AC and NAC data was assessed using Lin's concordance correlation coefficient followed by Bland-Altman plot analysis. Regarding endothelial function, NAC PET showed poor reproducibility and poor agreement with AC PET data. Conversely, NAC PET demonstrated high reproducibility and a strong agreement with AC PET for the assessment of MFR. Non-attenuation-corrected {sup 15}O-water PET provided an accurate measurement of MFR compared to attenuation-corrected PET. However, non-attenuation-corrected PET data were less effective for the assessment of endothelial function using CPT in this population. (orig.)

  1. Radiolabeling human peripheral blood stem cells for positron emission tomography (PET imaging in young rhesus monkeys.

    Alice F Tarantal

    Full Text Available These studies focused on a new radiolabeling technique with copper ((64Cu and zirconium ((89Zr for positron emission tomography (PET imaging using a CD45 antibody. Synthesis of (64Cu-CD45 and (89Zr-CD45 immunoconjugates was performed and the evaluation of the potential toxicity of radiolabeling human peripheral blood stem cells (hPBSC was assessed in vitro (viability, population doubling times, colony forming units. hPBSC viability was maintained as the dose of (64Cu-TETA-CD45 increased from 0 (92% to 160 µCi/mL (76%, p>0.05. Radiolabeling efficiency was not significantly increased with concentrations of (64Cu-TETA-CD45 >20 µCi/mL (p>0.50. Toxicity affecting both growth and colony formation was observed with hPBSC radiolabeled with ≥40 µCi/mL (p0.05, and a trend towards increased radiolabeling efficiency was noted as the dose of (89Zr-Df-CD45 increased, with a greater level of radiolabeling with 160 µCi/mL compared to 0-40 µCi/mL (p<0.05. A greater than 2,000 fold-increase in the level of (89Zr-Df-CD45 labeling efficiency was observed when compared to (64Cu-TETA-CD45. Similar to (64Cu-TETA-CD45, toxicity was noted when hPBSC were radiolabeled with ≥40 µCi/mL (p<0.05 (growth, colony formation. Taken together, 20 µCi/mL resulted in the highest level of radiolabeling efficiency without altering cell function. Young rhesus monkeys that had been transplanted prenatally with 25×10(6 hPBSC expressing firefly luciferase were assessed with bioluminescence imaging (BLI, then 0.3 mCi of (89Zr-Df-CD45, which showed the best radiolabeling efficiency, was injected intravenously for PET imaging. Results suggest that (89Zr-Df-CD45 was able to identify engrafted hPBSC in the same locations identified by BLI, although the background was high.

  2. Ventilation/Perfusion Positron Emission Tomography—Based Assessment of Radiation Injury to Lung

    Siva, Shankar, E-mail: shankar.siva@petermac.org [Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville (Australia); Hardcastle, Nicholas [Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne (Australia); Centre for Medical Radiation Physics, University of Wollongong, Wollongong (Australia); Kron, Tomas [Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne (Australia); Bressel, Mathias [Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, East Melbourne (Australia); Callahan, Jason [Centre for Molecular Imaging, Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne (Australia); MacManus, Michael P.; Shaw, Mark; Plumridge, Nikki [Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Hicks, Rodney J. [Centre for Molecular Imaging, Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Medicine, University of Melbourne, Parkville (Australia); Steinfort, Daniel [Department of Medicine, University of Melbourne, Parkville (Australia); Department of Cancer Medicine, Peter MacCallum Cancer Centre, East Melbourne (Australia); Ball, David L. [Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Hofman, Michael S. [Centre for Molecular Imaging, Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Medicine, University of Melbourne, Parkville (Australia)

    2015-10-01

    Purpose: To investigate {sup 68}Ga-ventilation/perfusion (V/Q) positron emission tomography (PET)/computed tomography (CT) as a novel imaging modality for assessment of perfusion, ventilation, and lung density changes in the context of radiation therapy (RT). Methods and Materials: In a prospective clinical trial, 20 patients underwent 4-dimensional (4D)-V/Q PET/CT before, midway through, and 3 months after definitive lung RT. Eligible patients were prescribed 60 Gy in 30 fractions with or without concurrent chemotherapy. Functional images were registered to the RT planning 4D-CT, and isodose volumes were averaged into 10-Gy bins. Within each dose bin, relative loss in standardized uptake value (SUV) was recorded for ventilation and perfusion, and loss in air-filled fraction was recorded to assess RT-induced lung fibrosis. A dose-effect relationship was described using both linear and 2-parameter logistic fit models, and goodness of fit was assessed with Akaike Information Criterion (AIC). Results: A total of 179 imaging datasets were available for analysis (1 scan was unrecoverable). An almost perfectly linear negative dose-response relationship was observed for perfusion and air-filled fraction (r{sup 2}=0.99, P<.01), with ventilation strongly negatively linear (r{sup 2}=0.95, P<.01). Logistic models did not provide a better fit as evaluated by AIC. Perfusion, ventilation, and the air-filled fraction decreased 0.75 ± 0.03%, 0.71 ± 0.06%, and 0.49 ± 0.02%/Gy, respectively. Within high-dose regions, higher baseline perfusion SUV was associated with greater rate of loss. At 50 Gy and 60 Gy, the rate of loss was 1.35% (P=.07) and 1.73% (P=.05) per SUV, respectively. Of 8/20 patients with peritumoral reperfusion/reventilation during treatment, 7/8 did not sustain this effect after treatment. Conclusions: Radiation-induced regional lung functional deficits occur in a dose-dependent manner and can be estimated by simple linear models with 4D-V/Q PET

  3. Multimodality Imaging Probe for Positron Emission Tomography and Fluorescence Imaging Studies

    Suresh K. Pandey

    2014-05-01

    Full Text Available Our goal is to develop multimodality imaging agents for use in cell tracking studies by positron emission tomography (PET and optical imaging (OI. For this purpose, bovine serum albumin (BSA was complexed with biotin (histologic studies, 5(6- carboxyfluorescein, succinimidyl ester (FAM SE (OI studies, and diethylenetriamine pentaacetic acid (DTPA for chelating gallium 68 (PET studies. For synthesis of BSA-biotin-FAM-DTPA, BSA was coupled to (+-biotin N-hydroxysuccinimide ester (biotin-NHSI. BSA- biotin was treated with DTPA-anhydride and biotin-BSA-DTPA was reacted with FAM. The biotin-BSA-DTPA-FAM was reacted with gallium chloride 3 to 5 mCi eluted from the generator using 0.1 N HCl and was passed through basic resin (AG 11 A8 and 150 mCi (100 μL, pH 7–8 was incubated with 0.1 mg of FAM conjugate (100 μL at room temperature for 15 minutes to give 66Ga-BSA-biotin-DTPA-FAM. A shaved C57 black mouse was injected with FAM conjugate (50 μL at one flank and FAM-68Ga (50 μL, 30 mCi at the other. Immediately after injection, the mouse was placed in a fluorescence imaging system (Kodak In-Vivo F, Bruker Biospin Co., Woodbridge, CT and imaged (Λex: 465 nm, Λem: 535 nm, time: 8 seconds, Xenon Light Source, Kodak. The same mouse was then placed under an Inveon microPET scanner (Siemens Medical Solutions, Knoxville, TN injected (intravenously with 25 μCi of 18F and after a half-hour (to allow sufficient bone uptake was imaged for 30 minutes. Molecular weight determined using matrix-associated laser desorption ionization (MALDI for the BSA sample was 66,485 Da and for biotin-BSA was 67,116 Da, indicating two biotin moieties per BSA molecule; for biotin-BSA-DTPA was 81,584 Da, indicating an average of 30 DTPA moieties per BSA molecule; and for FAM conjugate was 82,383 Da, indicating an average of 1.7 fluorescent moieties per BSA molecule. Fluorescence imaging clearly showed localization of FAM conjugate and FAM-68Ga at respective flanks of the mouse

  4. 18F-fluorodeoxyglucose positron emission tomography, aging, and apolipoprotein E genotype in cognitively normal persons.

    Knopman, David S; Jack, Clifford R; Wiste, Heather J; Lundt, Emily S; Weigand, Stephen D; Vemuri, Prashanthi; Lowe, Val J; Kantarci, Kejal; Gunter, Jeffrey L; Senjem, Matthew L; Mielke, Michelle M; Roberts, Rosebud O; Boeve, Bradley F; Petersen, Ronald C

    2014-09-01

    Our objective was to examine associations between glucose metabolism, as measured by (18)F-fluorodeoxyglucose positron emission tomography (FDG PET), and age and to evaluate the impact of carriage of an apolipoprotein E (APOE) ε4 allele on glucose metabolism and on the associations between glucose metabolism and age. We studied 806 cognitively normal (CN) and 70 amyloid-imaging-positive cognitively impaired participants (35 with mild cognitive impairment and 35 with Alzheimer's disease [AD] dementia) from the Mayo Clinic Study of Aging, Mayo Alzheimer's Disease Research Center and an ancillary study who had undergone structural MRI, FDG PET, and (11)C-Pittsburgh compound B (PiB) PET. Using partial volume corrected and uncorrected FDG PET glucose uptake ratios, we evaluated associations of regional FDG ratios with age and carriage of an APOE ε4 allele in CN participants between the ages of 30 and 95 years, and compared those findings with the cognitively impaired participants. In region-of-interest (ROI) analyses, we found modest but statistically significant declines in FDG ratio in most cortical and subcortical regions as a function of age. We also found a main effect of APOE ε4 genotype on FDG ratio, with greater uptake in ε4 noncarriers compared with carriers but only in the posterior cingulate and/or precuneus, lateral parietal, and AD-signature meta-ROI. The latter consisted of voxels from posterior cingulate and/or precuneus, lateral parietal, and inferior temporal. In age- and sex-matched CN participants the magnitude of the difference in partial volume corrected FDG ratio in the AD-signature meta-ROI for APOE ε4 carriers compared with noncarriers was about 4 times smaller than the magnitude of the difference between age- and sex-matched elderly APOE ε4 carrier CN compared with AD dementia participants. In an analysis in participants older than 70 years (31.3% of whom had elevated PiB), there was no interaction between PiB status and APOE ε4 genotype

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

    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.

  6. [18F]2-fluoro-2-deoxyglucose positron emission tomography/computed tomography in predicting radiation pneumonitis

    SONG Hao; YU Jin-ming; Feng-ming Kong; LU Jie; BAI Tong; MA Li; FU Zheng

    2009-01-01

    Background Prevention is presently the only available method to limit radiation-induced lung morbidity. A good predictor is the key point of prevention. This study aimed to investigate if [18F]2-fluoro-2-deoxyglucose (FDG) uptake changes in the lung after radiotherapy could be used as a new predictor for acute radiation pneumonitis (RP). Methods Forty-one patients with lung cancer underwent FDG positron emission tomography/computed tomography (FDG-PET/CT) imaging before and after radiotherapy. The mean standardized uptake value (SUV) was measured for the isodose regions of 0-9 Gy, 10-19 Gy, 20-29 Gy, 30-39 Gy, 40-49 Gy. The mean SUV of these regions after radiotherapy was compared with baseline. The mean SUV in patients who developed RP was also compared with that in those who did not. The statistical difference was determined by matched pair t test. The Radiation Therapy Oncology Group (RTOG)criteria were used for diagnosis and grading of RP.Results With a median follow-up of 12 months, 11 (26.8%) of the 41 patients developed grade 2 and above acute RP.The mean SUV of regions (10-19 Gy, 20-29 Gy, 30-39 Gy, 40-49 Gy) increased after radiation therapy in all 41 patients.The mean SUVs after radiation therapy were 0.54, 0.68, 1.31, 1.74 and 2.27 for 0-9 Gy, 10-19 Gy, 20-29 Gy, 30-39 Gy and 40-49 Gy, respectively. Before the radiation therapy, the mean SUV in each region was 0.53, 0.52, 0.52, 0.53 and 0.54, respectively. These patients had significantly higher FDG activities in regions receiving 10 Gy or more (P <0.001).Compared with their counterparts, the elevation of SUV was significantly greater in those patients who developed acute RP subsequently.Conclusion The mean SUV of the lung tissue may be a useful predictor for the acute RR FDG-PET/CT may play a new role in the study of the radiation damage of the lung.

  7. Lymphomatous involvement of gastrointestinal tract: Evaluation by positron emission tomography with 18F-fluorodeoxyglucose

    Sith Phongkitkarun; Vithya Varavithya; Toshiki Kazama; Silvana C Faria; Martha V Mar; Donald A Podoloff; Homer A Macapinlac

    2005-01-01

    AIM: To demonstrate the 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) findings in patients with non-Hodgkin's lymphoma (NHL) involving the gastrointestinal (GI) tract and the clinical utility of modality despite of the known normal uptake of FDG in the GI tract.METHODS: Thirty-three patients with biopsy-proven gastrointestinal NHL who had undergone FDG-PET scan were included. All the patients were injected with 10-15 mCi FDG and scanned approximately 60 min later with a CTI/Siemens HR (+) PET scanner. PET scans were reviewed and the maximum standard uptake value (SUVmax) of the lesions was measured before and after the treatment,if data were available and compared with histologic diagnoses.RESULTS: Twenty-five patients had a high-grade lymphoma and eight had a low-grade lymphoma. The stomach was the most common site of the involvement (20 patients). In high-grade lymphoma, PET showed focal nodular or diffuse hypermetabolic activity. The average SUVmax±SD was 11.58±5.83. After the therapy,the patients whose biopsies showed no evidence of lymphoma had a lower uptake without focal lesions.The SUVmax±SD decreased from 11.58±5.83 to 2.21±0.78. In patients whose post-treatment biopsies showed lymphoma, the SUVmax±SD was 9.42±6.27. Low-grade follicular lymphomas of the colon and stomach showed diffuse hypermetabolic activity in the bowel wall (SUVmax 8.2 and 10.3, respectively). The SUVmax was 2.02-3.8 (mean 3.02) in the stomach lesions of patients with MALT lymphoma.CONCLUSION: 18F-FDG PET contributes to the diagnosis of high-grade gastrointestinal non-Hodgkin's lymphoma,even when there is the normal background FDG activity. Furthermore, the SUV plays a role in evaluating treatment response. Low-grade NHL demonstrates FDG uptake but at a lesser intensity than seen in high-grade NHL.

  8. Image reconstruction for a Positron Emission Tomograph optimized for breast cancer imaging

    Virador, Patrick R.G.

    2000-04-01

    The author performs image reconstruction for a novel Positron Emission Tomography camera that is optimized for breast cancer imaging. This work addresses for the first time, the problem of fully-3D, tomographic reconstruction using a septa-less, stationary, (i.e. no rotation or linear motion), and rectangular camera whose Field of View (FOV) encompasses the entire volume enclosed by detector modules capable of measuring Depth of Interaction (DOI) information. The camera is rectangular in shape in order to accommodate breasts of varying sizes while allowing for soft compression of the breast during the scan. This non-standard geometry of the camera exacerbates two problems: (a) radial elongation due to crystal penetration and (b) reconstructing images from irregularly sampled data. Packing considerations also give rise to regions in projection space that are not sampled which lead to missing information. The author presents new Fourier Methods based image reconstruction algorithms that incorporate DOI information and accommodate the irregular sampling of the camera in a consistent manner by defining lines of responses (LORs) between the measured interaction points instead of rebinning the events into predefined crystal face LORs which is the only other method to handle DOI information proposed thus far. The new procedures maximize the use of the increased sampling provided by the DOI while minimizing interpolation in the data. The new algorithms use fixed-width evenly spaced radial bins in order to take advantage of the speed of the Fast Fourier Transform (FFT), which necessitates the use of irregular angular sampling in order to minimize the number of unnormalizable Zero-Efficiency Bins (ZEBs). In order to address the persisting ZEBs and the issue of missing information originating from packing considerations, the algorithms (a) perform nearest neighbor smoothing in 2D in the radial bins (b) employ a semi-iterative procedure in order to estimate the unsampled data

  9. Spatiotemporal Stability of Cu-ATSM and FLT Positron Emission Tomography Distributions During Radiation Therapy

    Bradshaw, Tyler J.; Yip, Stephen; Jallow, Ngoneh [Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin (United States); Forrest, Lisa J. [Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin (United States); Jeraj, Robert, E-mail: rjeraj@wisc.edu [Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin (United States); Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin (United States)

    2014-06-01

    Purpose: In dose painting, in which functional imaging is used to define biological targets for radiation therapy dose escalation, changes in spatial distributions of biological properties during treatment can compromise the quality of therapy. The goal of this study was to assess the spatiotemporal stability of 2 potential dose painting targets—hypoxia and proliferation—in canine tumors during radiation therapy. Methods and Materials: Twenty-two canine patients with sinonasal tumors (14 carcinoma and 8 sarcoma) were imaged before hypofractionated radiation therapy with copper(II)-diacetyl-bis(N4-methylthiosemicarbazone) (Cu-ATSM) positron emission tomography/computed tomography (PET/CT) for hypoxia and 3′-deoxy-3′-{sup 18}F-fluorothymidine (FLT) PET/CT for proliferation. The FLT scans were repeated after 2 fractions and the Cu-ATSM scans after 3 fractions. Midtreatment PET/CT images were deformably registered to pretreatment PET/CT images. Voxel-based Spearman correlation coefficients quantified the spatial stability of Cu-ATSM and FLT uptake distributions between pretreatment and midtreatment scans. Paired t tests determined significant differences between the patients' respective Cu-ATSM and FLT correlations coefficients. Standardized uptake value measures were also compared between pretreatment and midtreatment scans by use of paired t tests. Results: Spatial distributions of Cu-ATSM and FLT uptake were stable through midtreatment for both sarcomas and carcinomas: the population mean ± standard deviation in Spearman correlation coefficient was 0.88 ± 0.07 for Cu-ATSM and 0.79 ± 0.13 for FLT. The patients' Cu-ATSM correlation coefficients were significantly higher than their respective FLT correlation coefficients (P=.001). Changes in Cu-ATSM SUV measures from pretreatment to midtreatment were histology dependent: carcinomas experienced significant decreases in Cu-ATSM uptake (P<.05), whereas sarcomas did not (P>.20). Both histologies

  10. A Gaussian mixture model for definition of lung tumor volumes in positron emission tomography.

    Aristophanous, Michalis; Penney, Bill C; Martel, Mary K; Pelizzari, Charles A

    2007-11-01

    The increased interest in 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in radiation treatment planning in the past five years necessitated the independent and accurate segmentation of gross tumor volume (GTV) from FDG-PET scans. In some studies the radiation oncologist contours the GTV based on a computed tomography scan, while incorporating pertinent data from the PET images. Alternatively, a simple threshold, typically 40% of the maximum intensity, has been employed to differentiate tumor from normal tissue, while other researchers have developed algorithms to aid the PET based GTV definition. None of these methods, however, results in reliable PET tumor segmentation that can be used for more sophisticated treatment plans. For this reason, we developed a Gaussian mixture model (GMM) based segmentation technique on selected PET tumor regions from non-small cell lung cancer patients. The purpose of this study was to investigate the feasibility of using a GMM-based tumor volume definition in a robust, reliable and reproducible way. A GMM relies on the idea that any distribution, in our case a distribution of image intensities, can be expressed as a mixture of Gaussian densities representing different classes. According to our implementation, each class belongs to one of three regions in the image; the background (B), the uncertain (U) and the target (T), and from these regions we can obtain the tumor volume. User interaction in the implementation is required, but is limited to the initialization of the model parameters and the selection of an "analysis region" to which the modeling is restricted. The segmentation was developed on three and tested on another four clinical cases to ensure robustness against differences observed in the clinic. It also compared favorably with thresholding at 40% of the maximum intensity and a threshold determination function based on tumor to background image intensities proposed in a recent paper. The parts of the

  11. Development of a prototype Open-close positron emission tomography system

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Okumura, Satoshi; Komori, Masataka; Ogata, Yoshimune; Kato, Katsuhiko [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya (Japan); Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya (Japan); Hatazawa, Jun [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka (Japan); Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka (Japan)

    2015-08-15

    We developed a prototype positron emission tomography (PET) system based on a new concept called Open-close PET, which has two modes: open and close-modes. In the open-mode, the detector ring is separated into two halved rings and subject is imaged with the open space and projection image is formed. In the close-mode, the detector ring is closed to be a regular circular ring, and the subject can be imaged without an open space, and so reconstructed images can be made without artifacts. The block detector of the Open-close PET system consists of two scintillator blocks that use two types of gadolinium orthosilicate (GSO) scintillators with different decay times, angled optical fiber-based image guides, and a flat panel photomultiplier tube. The GSO pixel size was 1.6 × 2.4 × 7 mm and 8 mm for fast (35 ns) and slow (60 ns) GSOs, respectively. These GSOs were arranged into an 11 × 15 matrix and optically coupled in the depth direction to form a depth-of-interaction detector. The angled optical fiber-based image guides were used to arrange the two scintillator blocks at 22.5° so that they can be arranged in a hexadecagonal shape with eight block detectors to simplify the reconstruction algorithm. The detector ring was divided into two halves to realize the open-mode and set on a mechanical stand with which the distance between the two parts can be manually changed. The spatial resolution in the close-mode was 2.4-mm FWHM, and the sensitivity was 1.7% at the center of the field-of-view. In both the close- and open-modes, we made sagittal (y-z plane) projection images between the two halved detector rings. We obtained reconstructed and projection images of {sup 18}F-NaF rat studies and proton-irradiated phantom images. These results indicate that our developed Open-close PET is useful for some applications such as proton therapy as well as other applications such as molecular imaging.

  12. Molecular Imaging Probes for Positron Emission Tomography and Optical Imaging of Sentinel Lymph Node and Tumor

    Qin, Zhengtao

    Molecular imaging is visualizations and measurements of in vivo biological processes at the molecular or cellular level using specific imaging probes. As an emerging technology, biocompatible macromolecular or nanoparticle based targeted imaging probes have gained increasing popularities. Those complexes consist of a carrier, an imaging reporter, and a targeting ligand. The active targeting ability dramatically increases the specificity. And the multivalency effect may further reduce the dose while providing a decent signal. In this thesis, sentinel lymph node (SLN) mapping and cancer imaging are two research topics. The focus is to develop molecular imaging probes with high specificity and sensitivity, for Positron Emission Tomography (PET) and optical imaging. The objective of this thesis is to explore dextran radiopharmaceuticals and porous silicon nanoparticles based molecular imaging agents. Dextran polymers are excellent carriers to deliver imaging reporters or therapeutic agents due to its well established safety profile and oligosaccharide conjugation chemistry. There is also a wide selection of dextran polymers with different lengths. On the other hand, Silicon nanoparticles represent another class of biodegradable materials for imaging and drug delivery. The success in fluorescence lifetime imaging and enhancements of the immune activation potency was briefly discussed. Chapter 1 begins with an overview on current molecular imaging techniques and imaging probes. Chapter 2 presents a near-IR dye conjugated probe, IRDye 800CW-tilmanocept. Fluorophore density was optimized to generate the maximum brightness. It was labeled with 68Ga and 99mTc and in vivo SLN mapping was successfully performed in different animals, such as mice, rabbits, dogs and pigs. With 99mTc labeled IRDye 800CW-tilmanocept, chapter 3 introduces a two-day imaging protocol with a hand-held imager. Chapter 4 proposed a method to dual radiolabel the IRDye 800CW-tilmanocept with both 68Ga and

  13. Development of a prototype Open-close positron emission tomography system

    Yamamoto, Seiichi; Okumura, Satoshi; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Toshito, Toshiyuki; Komori, Masataka; Ogata, Yoshimune; Kato, Katsuhiko; Hatazawa, Jun

    2015-08-01

    We developed a prototype positron emission tomography (PET) system based on a new concept called Open-close PET, which has two modes: open and close-modes. In the open-mode, the detector ring is separated into two halved rings and subject is imaged with the open space and projection image is formed. In the close-mode, the detector ring is closed to be a regular circular ring, and the subject can be imaged without an open space, and so reconstructed images can be made without artifacts. The block detector of the Open-close PET system consists of two scintillator blocks that use two types of gadolinium orthosilicate (GSO) scintillators with different decay times, angled optical fiber-based image guides, and a flat panel photomultiplier tube. The GSO pixel size was 1.6 × 2.4 × 7 mm and 8 mm for fast (35 ns) and slow (60 ns) GSOs, respectively. These GSOs were arranged into an 11 × 15 matrix and optically coupled in the depth direction to form a depth-of-interaction detector. The angled optical fiber-based image guides were used to arrange the two scintillator blocks at 22.5° so that they can be arranged in a hexadecagonal shape with eight block detectors to simplify the reconstruction algorithm. The detector ring was divided into two halves to realize the open-mode and set on a mechanical stand with which the distance between the two parts can be manually changed. The spatial resolution in the close-mode was 2.4-mm FWHM, and the sensitivity was 1.7% at the center of the field-of-view. In both the close- and open-modes, we made sagittal (y-z plane) projection images between the two halved detector rings. We obtained reconstructed and projection images of 18F-NaF rat studies and proton-irradiated phantom images. These results indicate that our developed Open-close PET is useful for some applications such as proton therapy as well as other applications such as molecular imaging.

  14. [11C]-(R)-PK11195 positron emission tomography in patients with complex regional pain syndrome

    Jeon, So Yeon; Seo, Seongho; Lee, Jae Sung; Choi, Soo-Hee; Lee, Do-Hyeong; Jung, Ye-Ha; Song, Man-Kyu; Lee, Kyung-Jun; Kim, Yong Chul; Kwon, Hyun Woo; Im, Hyung-Jun; Lee, Dong Soo; Cheon, Gi Jeong; Kang, Do-Hyung

    2017-01-01

    Abstract Complex regional pain syndrome (CRPS) is characterized by severe and chronic pain, but the pathophysiology of this disease are not clearly understood. The primary aim of our case–control study was to explore neuroinflammation in patients with CRPS using positron emission tomography (PET), with an 18-kDa translocator protein specific radioligand [11C]-(R)-PK11195. [11C]-(R)-PK11195 PET scans were acquired for 11 patients with CRPS (30–55 years) and 12 control subjects (30–52 years). Parametric image of distribution volume ratio (DVR) for each participant was generated by applying a relative equilibrium-based graphical analysis. The DVR of [11C]-(R)-PK11195 in the caudate nucleus (t(21) = −3.209, P = 0.004), putamen (t(21) = −2.492, P = 0.022), nucleus accumbens (t(21) = −2.218, P = 0.040), and thalamus (t(21) = −2.395, P = 0.026) were significantly higher in CRPS patients than in healthy controls. Those of globus pallidus (t(21) = −2.045, P = 0.054) tended to be higher in CRPS patients than in healthy controls. In patients with CRPS, there was a positive correlation between the DVR of [11C]-(R)-PK11195 in the caudate nucleus and the pain score, the visual analog scale (r = 0.661, P = 0.026, R2 = 0.408) and affective subscales of McGill Pain Questionnaire (r = 0.604, P = 0.049, R2 = 0.364). We demonstrated that neuroinflammation of CRPS patients in basal ganglia. Our results suggest that microglial pathology can be an important pathophysiology of CRPS. Association between the level of caudate nucleus and pain severity indicated that neuroinflammation in this region might play a key role. These results may be essential for developing effective medical treatments. PMID:28072713

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

    Bowen, Stephen R., E-mail: srbowen@wisc.edu [University of Wisconsin School of Medicine and Public Health, Department of Medical Physics, Madison, WI 53706 (United States); Kogel, Albert J. van der [University Medical Centre St. Radboud, Nijmegen (Netherlands); Nordsmark, Marianne [Aarhus University Hospital, Department of Experimental Clinical Oncology, Aarhus (Denmark); Bentzen, Soren M. [University of Wisconsin School of Medicine and Public Health, Department of Medical Physics, Madison, WI 53706 (United States); University of Wisconsin School of Medicine and Public Health, Department of Human Oncology, Clinical Sciences Center, Madison, WI 53792 (United States); Jeraj, Robert [University of Wisconsin School of Medicine and Public Health, Department of Medical Physics, Madison, WI 53706 (United States); University of Wisconsin School of Medicine and Public Health, Department of Human Oncology, Clinical Sciences Center, Madison, WI 53792 (United States); Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)

    2011-08-15

    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, [{sup 61}Cu]Cu-ATSM and [{sup 18}F]FMISO, were characterized via computational modeling to address these challenges. Materials and Methods: An electrochemical formalism describing bioreductive retention mechanisms of these tracers under steady-state conditions was adopted to relate time-averaged activity concentration to tissue partial oxygen tension (PO{sub 2}), a common metric of hypoxia. Chemical equilibrium constants of product concentration to reactant concentration ratios were determined from free energy changes and reduction potentials of pertinent reactions reported in the literature. Resulting transformation functions between tracer uptake and PO{sub 2} were compared against measured values in preclinical models. Additionally, calculated PO{sub 2} distributions from imaged Cu-ATSM tracer activity concentrations of 12 head and neck squamous cell carcinoma (HNSCC) patients were validated against microelectrode PO{sub 2} measurements in 69 HNSCC patients. Results: Both Cu-ASTM- and FMISO-modeled PO{sub 2} transformation functions were in agreement with preclinical measured values within single-deviation confidence intervals. High correlation (r{sup 2}=0.94, P<.05) was achieved between modeled PO{sub 2} distributions and measured distributions in the patient populations. On average, microelectrode hypoxia thresholds (2.5 and 5.0 mmHg) corresponded to higher Cu-ATSM uptake [2.5 and 2.0 standardized uptake value (SUV)] and lower FMISO uptake (2.0 and 1.4 SUV). Uncertainties in the models were dominated by variations in the estimated specific activity and intracellular acidity. Conclusions: Results indicated that the high dynamic range of Cu-ATSM uptake was representative of a narrow range of low oxygen tension whose values were dependent on

  16. Study of the silicon photomultipliers and their applications in positron emission tomography

    Xu, Chen

    2014-05-15

    This thesis deals with silicon photomultipliers (SiPM) used in scintillation detectors and their applications in positron emission tomography (PET). The study of the SiPM is mainly focused on the application to the proposed EndoTOFPET-US detector, which is a multi-modality PET detector facilitating the development of new biomarkers for pancreas and prostate cancers. A Monte Carlo simulation tool is developed for the optimization of the detector's single channel design. In order to obtain a 200 ps system coincidence time resolution and maximize the detector sensitivity, the requirements for the crystal geometry, light yield and SiPM photon detection efficiency are specified based on the simulation study. In addition, the nonlinear response of the SiPM can be corrected by the simulation tool and the energy resolution of the detector is extracted. A series of measurements are established to characterize SiPMs in a fast and reliable way with high precision. The static characterization measures the value of different components in the derived electrical model of the SiPM, whereas the dynamic characterization extracts parameters that is crucial for the operation of the SiPM. Several SiPM samples are tested and their characteristics are compared. The developed setup and the precision of the measurement fulfill the requirements of the quality assurance test for the commissioning of the EndoTOFPET-US detector. The test foresees large quantities of SiPMs to be characterized. In addition, the developed measuring procedure has contributed to the study of X-ray induced surface damage of a SiPM from Hamamatsu. Characteristics of the device are measured before and after irradiating the SiPM with different X-ray doses, the results are compared and discussed. A comparative study of a digital and an analog SiPM in gamma spectroscopy with the inorganic scintillator is presented. The characteristics of a prototype digital SiPM that is developed for the EndoTOFPETUS detector is

  17. Role of 18F-fluorodeoxyglucose positron emission tomography imaging in surgery for pancreatic cancer

    Hisao Wakabayashi; Yoshihiro Nishiyama; Tsuyoshi Otani; Takanori Sano; Shinichi Yachida; Keiichi Okano; Kunihiko Izuishi; Yasuyuki Suzuki

    2008-01-01

    AIM:To evaluate the role of positron emission tomo- graphy using 18F-fluorodeoxyglucose (FDG-PET) in the surgical management of patients with pancreatic cancer,including the diagnosis, staging, and selection of patients for the subsequent surgical treatment.METHODS: This study involved 53 patients with proven primary pancreatic cancer. The sensitivity of diagnosing the primary cancer was examined for FDG-PET, CT,cytological examination of the bile or pancreatic juice,and the serum levels of carcinoembrionic antigens (CEA) and carbohydrate antigen 19-9 (CA19-9). Next, the accuracy of staging was compared between FDG-PET and CT. Finally, FDG-PET was analyzed semiquantitatively using the standard uptake value (SUV). The impact of the SUV on patient management was evaluated by examining the correlations between the SUV and the histological findings of cancer.RESULTS: The sensitivity of FDG-PET, CT, cytological examination of the bile or pancreatic juice, and the serum levels of CEA and CA19-9 were 92.5%, 88.7%, 46.4%, 37.7% and 69.8%, respectively. In staging, FDG-PET was superior to CT only in diagnosing distant disease (bone metastasis). For local staging, the sensitivity of CT was better than that of FDG-PET. The SUV did not correlate with the pTNM stage, grades, invasions to the vessels and nerve, or with the size of the tumor. However, there was a statistically significant difference (4.6±2.9 vs 7.8±4.5, P = 0.024) in the SUV between patients with respectable and unresectable disease. CONCLUSION: FDG-PET is thus considered to be useful in the diagnosis of pancreatic cancer. However, regarding the staging of the disease, FDG-PET is not considered to be a sufficiently accurate diagnostic modality. Although the SUV does not correlate with the patho-histological prognostic factors, it may be useful in selecting patients who should undergo subsequent surgical treatment.

  18. In-vivo detection of the erythropoietin receptor in tumours using positron emission tomography

    Fuge, Felix; Doleschel, Dennis; Rix, Anne; Gremse, Felix; Lederle, Wiltrud; Kiessling, Fabian [RWTH Aachen University, Department for Experimental Molecular Imaging (ExMI), Medical Faculty, Aachen (Germany); Wessner, Axel [Roche Diagnostics GmbH, R and D RPD Protein Chemistry, Penzberg (Germany); Winz, Oliver; Mottaghy, Felix [University Clinic RWTH Aachen, Clinic for Nuclear Medicine, Aachen (Germany)

    2014-09-09

    Recombinant human erythropoietin (rhuEpo) is used clinically to treat anaemia. However, rhuEpo-treated cancer patients show decreased survival rates and erythropoietin receptor (EpoR) expression has been found in patient tumour tissue. Thus, rhuEpo application might promote EpoR{sup +} tumour progression. We therefore developed the positron emission tomography (PET)-probe {sup 68}Ga-DOTA-rhuEpo and evaluated its performance in EpoR{sup +} A549 non-small-cell lung cancer (NSCLC) xenografts. {sup 68}Ga-DOTA-rhuEpo was generated by coupling DOTA-hydrazide to carbohydrate side-chains of rhuEpo. Biodistribution was determined in tumour-bearing mice 0.5, 3, 6, and 9 h after probe injection. Competition experiments were performed by co-injecting {sup 68}Ga-DOTA-rhuEpo and rhuEpo in five-fold excess. Probe specificity was further evaluated histologically using Epo-Cy5.5 stainings. The blood half-life of {sup 68}Ga-DOTA-rhuEpo was 2.6 h and the unbound fraction was cleared by the liver and kidney. After 6 h, the highest tumour to muscle ratio was reached. The highest {sup 68}Ga-DOTA-rhuEpo accumulation was found in liver (10.06 ± 6.26%ID/ml), followed by bone marrow (1.87 ± 0.53%ID/ml), kidney (1.58 ± 0.39 %ID/ml), and tumour (0.99 ± 0.16%ID/ml). EpoR presence in these organs was histologically confirmed. Competition experiments showed significantly (p < 0.05) lower PET-signals in tumour and bone marrow at 3 and 6 h. {sup 68}Ga-DOTA-rhuEpo shows favourable pharmacokinetic properties and detects EpoR specifically. Therefore, it might become a valuable radiotracer to monitor EpoR status in tumours and support decision-making in anaemia therapy. (orig.)

  19. Positron emission tomography imaging of CD105 expression during tumor angiogenesis

    Hong, Hao [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Yang, Yunan [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Third Military Medical University, Department of Ultrasound, Xinqiao Hospital, Chongqing (China); Zhang, Yin; Engle, Jonathan W.; Barnhart, Todd E.; Nickles, Robert J. [University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); Leigh, Bryan R. [TRACON Pharmaceuticals, Inc., San Diego, CA (United States); Cai, Weibo [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin Carbone Cancer Center, Madison, WI (United States); University of Wisconsin - Madison, Departments of Radiology and Medical Physics, School of Medicine and Public Health, Madison, WI (United States)

    2011-07-15

    Overexpression of CD105 (endoglin) correlates with poor prognosis in many solid tumor types. Tumor microvessel density (MVD) assessed by CD105 staining is the current gold standard for evaluating tumor angiogenesis in the clinic. The goal of this study was to develop a positron emission tomography (PET) tracer for imaging CD105 expression. TRC105, a chimeric anti-CD105 monoclonal antibody, was conjugated to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and labeled with {sup 64}Cu. FACS analysis and microscopy studies were performed to compare the CD105 binding affinity of TRC105 and DOTA-TRC105. PET imaging, biodistribution, blocking, and ex vivo histology studies were performed on 4T1 murine breast tumor-bearing mice to evaluate the ability of {sup 64}Cu-DOTA-TRC105 to target tumor angiogenesis. Another chimeric antibody, cetuximab, was used as an isotype-matched control. FACS analysis of human umbilical vein endothelial cells (HUVECs) revealed no difference in CD105 binding affinity between TRC105 and DOTA-TRC105, which was further validated by fluorescence microscopy. {sup 64}Cu labeling was achieved with high yield and specific activity. Serial PET imaging revealed that the 4T1 tumor uptake of the tracer was 8.0 {+-} 0.5, 10.4 {+-} 2.8, and 9.7 {+-} 1.8%ID/g at 4, 24, and 48 h post-injection, respectively (n = 3), higher than most organs at late time points which provided excellent tumor contrast. Biodistribution data as measured by gamma counting were consistent with the PET findings. Blocking experiments, control studies with {sup 64}Cu-DOTA-cetuximab, as well as ex vivo histology all confirmed the in vivo target specificity of {sup 64}Cu-DOTA-TRC105. This is the first successful PET imaging study of CD105 expression. Fast, prominent, persistent, and CD105-specific uptake of the tracer in the 4T1 tumor was observed. Further studies are warranted and currently underway. (orig.)

  20. Development of Traceable Phantoms for Improved Image Quantification in Positron Emission Tomography

    Zimmerman, Brian

    2014-03-01

    Clinical trials for new drugs increasingly rely on imaging data to monitor patient response to the therapy being studied. In the case of radiopharmaceutical applications, imaging data are also used to estimate organ and tumor doses in order to arrive at the optimal dosage for safe and effective treatment. Positron Emission Tomography (PET) is one of the most commonly used imaging modalities for these types of applications. In large, multicenter trials it is crucial to minimize as much as possible the variability that arises due to use of different types of scanners and other instrumentation so that the biological response can be more readily evaluated. This can be achieved by ensuring that all the instruments are calibrated to a common standard and that their performance is continuously monitored throughout the trial. Maintaining links to a single standard also enables the comparability of data acquired on a heterogeneous collection of instruments in different clinical settings. As the standards laboratory for the United States, the National Institute of Standards and Technology (NIST) has been developing a suite of phantoms having traceable activity content to enable scanner calibration and performance testing. The configurations range from small solid cylindrical sources having volumes from 1 mL to 23 mL to large cylinders having a total volume of 9 L. The phantoms are constructed with 68Ge as a long-lived substitute for the more clinically useful radionuclide 18F. The contained activity values are traceable to the national standard for 68Ge and are also linked to the standard for 18F through a careful series of comparisons. The techniques that have been developed are being applied to a variety of new phantom configurations using different radionuclides. Image-based additive manufacturing techniques are also being investigated to create fillable phantoms having irregular shapes which can better mimic actual organs and tumors while still maintaining traceability

  1. Transfer of learning with an application to the physics of positron emission tomography

    Aryal, Bijaya

    2007-12-01

    A series of teaching activities using physical models was developed to present some portions of physics of Positron Emission Tomography (PET) and investigate students' understanding and transfer of learning in physics to a medical technology. A teaching interview protocol consistent with a qualitative research methodology was developed and administered to the students enrolled in an algebra-based introductory level physics course. 16 students participated in individual interviews and another 21 students participated in the group sessions. The major objectives of the teaching interviews were to investigate students' transfer of physics learning from their prior experiences to the provided physical models, from one model to the other and from the models to the PET problems. The study adapted phenomenological research methodology in analyzing students' use of cognitive resources and cognitive strategies during knowledge construction and reconstruction. A resource based transfer model framed under the cognitive theory of learning and consistent with contemporary views of transfer was used to describe the transfer of physics learning. Results of the study indicated both appropriate and inappropriate use of the students' prior conceptual resources in novel contexts. Scaffolding and questioning were found to be effective in activating appropriate and suppressing the inappropriate resources. The physical models used as analogies were found useful in transferring physics learning to understand image construction in PET. Positive transfer was possible when the models were introduced in an appropriate sequence. The results of the study indicate the occurrence of three types of non-scaffolded transfer---spontaneous, semi spontaneous and non-spontaneous. The research found connections between sequencing of hints and phrasing of information in activating students' different conceptual resources. A qualitative investigation based on Vygotsky's Zone of Proximal Development (ZPD

  2. Image reconstruction for a Positron Emission Tomograph optimized for breast cancer imaging

    Virador, Patrick R.G. [Univ. of California, Berkeley, CA (United States)

    2000-04-01

    The author performs image reconstruction for a novel Positron Emission Tomography camera that is optimized for breast cancer imaging. This work addresses for the first time, the problem of fully-3D, tomographic reconstruction using a septa-less, stationary, (i.e. no rotation or linear motion), and rectangular camera whose Field of View (FOV) encompasses the entire volume enclosed by detector modules capable of measuring Depth of Interaction (DOI) information. The camera is rectangular in shape in order to accommodate breasts of varying sizes while allowing for soft compression of the breast during the scan. This non-standard geometry of the camera exacerbates two problems: (a) radial elongation due to crystal penetration and (b) reconstructing images from irregularly sampled data. Packing considerations also give rise to regions in projection space that are not sampled which lead to missing information. The author presents new Fourier Methods based image reconstruction algorithms that incorporate DOI information and accommodate the irregular sampling of the camera in a consistent manner by defining lines of responses (LORs) between the measured interaction points instead of rebinning the events into predefined crystal face LORs which is the only other method to handle DOI information proposed thus far. The new procedures maximize the use of the increased sampling provided by the DOI while minimizing interpolation in the data. The new algorithms use fixed-width evenly spaced radial bins in order to take advantage of the speed of the Fast Fourier Transform (FFT), which necessitates the use of irregular angular sampling in order to minimize the number of unnormalizable Zero-Efficiency Bins (ZEBs). In order to address the persisting ZEBs and the issue of missing information originating from packing considerations, the algorithms (a) perform nearest neighbor smoothing in 2D in the radial bins (b) employ a semi-iterative procedure in order to estimate the unsampled data

  3. 18F-fluorodeoxyglucose positron emission tomography in the diagnosis of small pancreatic cancer

    Keiichi Okano; Keitaro Kakinoki; Shintaro Akamoto; Masanobu Hagiike; Hisashi Usuki; Yuka Yamamoto; Yoshihiro Nishiyama; Yasuyuki Suzuki

    2011-01-01

    AIM: To investigate the role of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the diagnosis of small pancreatic cancer.METHODS: This study involved 31 patients with proven invasive ductal cancer of the pancreas. The patients were divided into 3 groups according to the maximum diameter of the tumor: TS1 (maximum tumor size ≤ 2.0 cm),TS2 (> 2.0 cm and ≤ 4.0 cm) or TS3-4 (> 4.0 cm). The relationships between the TS and various diagnostic tools, including FDG-PET with dual time point evaluation,were analyzed.RESULTS: The tumors ranged from 1.3 to 11.0 cm in diameter. Thirty of the 31 patients (97%) had a positive FDG-PET study. There were 5 patients classified as TS1,15 as TS2 and 11 as TS3-4. The sensitivity of FDG-PET,computed tomography (CT) and magnetic resonance imaging (MRI) were 100%, 40%, 0% in TS1, 93%,93%, 89% in TS2 and 100%, 100%, 100% in TS3-4.The sensitivity of FDG-PET was significantly higher in comparison to CT and MRI in patients with TS1 (P <0.032). The mean standardized uptake values (SUVs)did not show a significant difference in relation to the TS (TS1: 5.8 ± 4.5, TS2: 5.7 ± 2.2, TS3-4: 8.2 ± 3.9),respectively. All the TS1 tumors (from 13 to 20 mm)showed higher SUVs in FDG-PET with dual time point evaluation in the delayed phase compared with the early phase, which suggested the lesions were malignant.CONCLUSION: These results indicate that FDG-PET with dual time point evaluation is a useful modality for the detection of small pancreatic cancers with a diameter of less than 20 mm.

  4. The relationship between cerebrospinal fluid markers of Alzheimer pathology and positron emission tomography tau imaging.

    Gordon, Brian A; Friedrichsen, Karl; Brier, Matthew; Blazey, Tyler; Su, Yi; Christensen, Jon; Aldea, Patricia; McConathy, Jonathan; Holtzman, David M; Cairns, Nigel J; Morris, John C; Fagan, Anne M; Ances, Beau M; Benzinger, Tammie L S

    2016-08-01

    The two primary molecular pathologies in Alzheimer's disease are amyloid-β plaques and tau-immunoreactive neurofibrillary tangles. Investigations into these pathologies have been restricted to cerebrospinal fluid assays, and positron emission tomography tracers that can image amyloid-β plaques. Tau tracers have recently been introduced into the field, although the utility of the tracer and its relationship to other Alzheimer biomarkers are still unknown. Here we examined tau deposition in 41 cognitively normal and 11 cognitively impaired older adults using the radioactive tau ligand (18)F-AV-1451 (previously known as T807) who also underwent a lumbar puncture to assess cerebrospinal fluid levels of total tau (t-tau), phosphorylated tau181 (p-tau181) and amyloid-β42 Voxel-wise statistical analyses examined spatial patterns of tau deposition associated with cognitive impairment. We then related the amount of tau tracer uptake to levels of cerebrospinal fluid biomarkers. All analyses controlled for age and gender and, when appropriate, the time between imaging and lumbar puncture assessments. Symptomatic individuals (Clinical Dementia Rating > 0) demonstrated markedly increased levels of tau tracer uptake. This elevation was most prominent in the temporal lobe and temporoparietal junction, but extended more broadly into parietal and frontal cortices. In the entire cohort, there were significant relationships among all cerebrospinal fluid biomarkers and tracer uptake, notably for tau-related cerebrospinal fluid markers. After controlling for levels of amyloid-β42, the correlations with tau uptake were r = 0.490 (P < 0.001) for t-tau and r = 0.492 (P < 0.001) for p-tau181 Within the cognitively normal cohort, levels of amyloid-β42, but not t-tau or p-tau181, were associated with elevated tracer binding that was confined primarily to the medial temporal lobe and adjacent neocortical regions. AV-1451 tau binding in the medial temporal, parietal, and frontal cortices

  5. Role of F18 fluorodeoxyglucose positron-emission tomography/computed tomography in the management of Askin's tumor.

    Santhosh, Sampath; Kashyap, Raghava; Bhattacharya, Anish; Kumar Jindal, Surinder; Rai Mittal, Bhagwant

    2013-07-01

    A primitive neuroectodermal tumor (PNET) of the thoraco-abdominal region is one of a group of small round cell tumors usually found in children and young adults, originally described by Askin et al. Most cases arise in the soft-tissues of the thorax, but may rarely occur within the lung with the symptoms of chest wall pain, pleural effusion and dyspnea. The authors present two cases demonstrating the utility of F18 fluorodeoxyglucose positron-emission tomography/computed tomography in the staging and prognosis of PNET of the chest wall.

  6. Novel amphiphilic probes for [18F]-radiolabeling preformed liposomes and determination of liposomal trafficking by positron emission tomography.

    Urakami, Takeo; Akai, Shuji; Katayama, Yurie; Harada, Norihiro; Tsukada, Hideo; Oku, Naoto

    2007-12-27

    Positron-emission tomography (PET) is a noninvasive real-time functional imaging system and is expected to be useful for the development of new drug candidates in clinical trials. For its application with preformulated liposomes, we devised an optimized [18F]-compound and developed a direct liposome modification method that we termed the "solid-phase transition method". We were successful in using 1-[18F]fluoro-3,6-dioxatetracosane ([18F]7a) for in vivo trafficking of liposomes. This method might be a useful tool in preclinical and clinical studies of lipidic particle-related drugs.

  7. Normal Positron Emission Tomography-Computerized Tomogram in a Patient with Apparent Mesenteric Panniculitis: Biopsy Is Still the Answer

    Eli D. Ehrenpreis

    2009-04-01

    Full Text Available Mesenteric panniculitis (also known as sclerosing mesenteritis is a chronic inflammatory disease of the mesenteric connective tissue. It is known to have a wide spectrum of clinical and radiological presentations. In general, biopsy is recommended for diagnosis; however, a recent study proposed that a negative positron emission tomography- computerized tomography (PET-CT scan is accurate in differentiating benign and neoplastic mesenteric processes [Br J Radiol 2006;79:37–43]. The following case report questions the accuracy of PET-CT in this setting and confirms the requirement for biopsy to rule out the presence of mesenteric lymphoma.

  8. Comparison of diffuse optical tomography of human breast with whole-body and breast-only positron emission tomography.

    Konecky, Soren D; Choe, Regine; Corlu, Alper; Lee, Kijoon; Wiener, Rony; Srinivas, Shyam M; Saffer, Janet R; Freifelder, Richard; Karp, Joel S; Hajjioui, Nassim; Azar, Fred; Yodh, Arjun G

    2008-02-01

    We acquire and compare three-dimensional tomographic breast images of three females with suspicious masses using diffuse optical tomography (DOT) and positron emission tomography (PET). Co-registration of DOT and PET images was facilitated by a mutual information maximization algorithm. We also compared DOT and whole-body PET images of 14 patients with breast abnormalities. Positive correlations were found between total hemoglobin concentration and tissue scattering measured by DOT, and fluorodeoxyglucose (18F-FDG) uptake. In light of these observations, we suggest potential benefits of combining both PET and DOT for characterization of breast lesions.

  9. Possibilities of positron emission tomography in the diagnosis of primary and recurrent ovarian cancer: a review of literature

    L. A. Ashrafyan

    2012-01-01

    Full Text Available Positron emission tomography (PET is a current radionuclide imaging technique that can supplement a diagnostic process with information on physiological and metabolic disorders in the foci of injury and specify the characteristics of a tumor process. The paper analyzes publications on the use of PET with 18F-fluorodeoxyglucose in different clinical situations in the presence of ovarian cancer for both the identification of early-stage disease, the differential diagnosis of ovarian masses and the timely detection of recurrences, follow-up during and after combination treatment. The authors’ opinions that the technique is restricted, which yields false-positive and false-negative results, are given.

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

    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...

  11. Positron emission tomography assessment of effects of benzodiazepines on regional glucose metabolic rate in patients with anxiety disorder

    Buchsbaum, M.S.; Wu, J.; Haier, R.; Hazlett, E.; Ball, R.; Katz, M.; Sokolski, K.; Lagunas-Solar, M.; Langer, D.

    1987-06-22

    Patients with generalized anxiety disorder (n = 18) entered a 21-day, double-blind, placebo-controlled random assignment trial of clorazepate. Positron emission tomography with YF-deoxyglucose was carried out before and after treatment. Decreases in glucose metabolic rate in visual cortex and relative increases in the basal ganglia and thalamus were found. A correlation between regional changes in metabolic rate and regional benzodiazepine receptor binding density from other human autopsy studies was observed; brain regions highest in receptor density showed the greatest decrease in rate.

  12. Adequacy of compartmental model for positron emission tomography examinations; Adequacao de modelo compartimental para exames de tomografia por emissao de positrons

    Silva, Joao Eduardo Maeda Moreira da; Furuie, Sergio Shiguemi [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia de Telecomunicacoes e Controle. Lab. de Engenharia Biomedica

    2011-12-15

    The objective of this work is the determination of the most adequate compartmental model for the study of physiological dynamics based on positron emission tomography exams. We propose the use of Akaike's information criterion for the optimal model selection, and Levenberg-Marquardt algorithm with sensitivity equations for the task of estimating the characteristic parameters of the differential equations describing the models. We have considered three compartmental structures represented, respectively, by two compartments and two characteristic constants, three compartments and four characteristic constants and four compartments and six characteristics constants. The data considered in this work were synthesized taking into account key features of a real tomography exam, such as type and level of noise and morphology of the input function of the system. Applying the proposed methodology with three noise levels (low, medium and high), we obtained agreement of the best model with strong and considerable degrees (with Kappa indexes equal to 0.95, 0.93 and 0.63, respectively). It was observed that, with high noise level and more complex models (four compartments), the classification is deteriorated due to lack of data for the decision. Programs have been developed and a graphical interface that can be used in research, development, simulation and parameter identification of compartmental models, supporting analysis of clinical diagnostics and scientific practices. (author)

  13. Micro tomography prototype by positron emission. Spatial resolution and metabolic studies;Prototipo de microtomografo por emision de positrones. Resolucion espacial y estudios metabolicos

    Alva S, H.; Murrieta, T.; Ruiz T, C.; Brandan, M. E.; Martinez D, A.; Rodriguez V, M., E-mail: halva@fisica.unam.m [UNAM, Instituto de Fisica, Circuito de la Investigacion Cientifica s/n, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2010-07-01

    During the past 4 years, the Medical Physics and Dosimetry Group at the Physics Institute, UNAM, has developed a positron emission tomography prototype for small-animal imaging (micro PET). The system is composed of pix elated, cerium-doped lutetium yttrium oxy orthosilicate scintillation crystal arrays coupled to position-sensitive photomultiplier tubes. Detector electronic signals are processed by nuclear instrumentation modules and are digitized by a multichannel data acquisition board. The tomographic reconstruction is performed by filtered backprojection from a set of distortion- and nonuniformity- corrected projections taken at different angles. In this work, the reconstructed spatial resolution was evaluated from the line spread function with a mean value of 2.36 +- 0.44 mm. In addition, the first metabolic studies of 30 g, healthy mice, injected with {sup 1}8{sup F} labeled fluorodeoxyglucose and sodium fluoride are reported. They display normal glucose uptake and skeletal structure, respectively. The micro PET can be a useful tool for radiation detector physics research and its applications in nuclear medicine. (Author)

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

    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

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

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

    2001-01-01

    pigs were given positron-labelled ammonia, (13)NH(3), into the portal vein and into the vena cava as successive 2-min infusions followed by 22-min dynamic liver scanning. Vena cava infusion data were used to account for recirculation of tracer and metabolites following the portal vein infusion...

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

    Kuhl, D.E.

    1993-01-01

    This progress report describes accomplishments of four programs. The four programs are entitled (1) Faster,simpler processing of positron-computing precursors: New physicochemical approaches, (2) Novel solid phase reagents and methods to improve radiosynthesis and isotope production, (3) Quantitative evaluation of the extraction of information from PET images, and (4) Optimization of tracer kinetic methods for radioligand studies in PET.

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

    Caldarella C

    2013-06-01

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

  18. SU-E-T-230: Measurement of Proton-Activated Positron Emission with PRESAGE 3-D Dosimeters

    Carroll, M; Mawlawi, O; Ibbott, G [University of Texas MD Anderson Cancer Center, Houston, TX (United States); Adamovics, J [John Adamovics, Skillman, NJ (United States)

    2014-06-01

    Purpose: Measurement of positron emission following proton beam irradiation of a target has been studied as a method of in-vivo dosimetry. Relative dosimetry studies between a phantom and treatment plan are susceptible to range uncertainties from material heterogeneities and setup error. By using the radiochromic polyurethane dosimeter PRESAGE, we can correlate the proton dose distribution to the PET activity measurement within a single detector. The PRESAGE formulation used was developed for high-LET proton radiotherapy, has similar density and RLSP to tissue, and consists of a greater carbon component, which gives it a higher positron signal than many other 3D detectors. Methods: Three cylindrical PRESAGE dosimeters were irradiated semi-uniformly to 500 cGy with 180- MeV protons. The beam was directed along the dosimeter axis and delivered a 2-cm SOBP at the center of the dosimeter. The dosimeters were rushed to a nearby PET/CT where imaging began within 15 minutes, less than a single half-life of 11C. A 3-hr measurement captured the full activation decay. Afterwards, the dose profiles were measured by optical-CT. A direct comparison between the measured dose and the positron emission was performed using CERR software. Results: The correlations between dose distributions and PET activity were consistent with previous studies in that the proximal region of the SOBP displayed the highest activity. The spatial distributions between the dose and activity were similar. Along the central axis of the beam, we found a shift in the distal 80% of 1 cm. The lateral profile showed good agreement between dose and activity. PET imaging times between 30-min and 3-hrs showed <5% discrepancy. Conclusion: PRESAGE dosimeters offer a strong and unique potential to accurately correlate dosimetric and PET activation information. Implementation in an anthropomorphic phantom could be used to study representative treatment plans. NIH grant 5R01CA100835.

  19. The predictive role of interim positron emission tomography for Hodgkin lymphoma treatment outcome is confirmed using the interpretation criteria of the Deauville five-point scale

    Gallamini, Andrea; Barrington, Sally F; Biggi, Alberto

    2014-01-01

    A retrospective, international, multicenter study was undertaken to assess: (i) the prognostic role of 'interim' positron emission tomography performed during treatment with doxorubicin, bleomycin, vinblastine and dacarbazine in patients with Hodgkin lymphoma; and (ii) the reproducibility...... of the Deauville five-point scale for the interpretation of interim positron emission tomography scan. Two hundred and sixty patients with newly diagnosed Hodgkin lymphoma were enrolled. Fifty-three patients with early unfavorable and 207 with advanced-stage disease were treated with doxorubicin, bleomycin......, vinblastine and dacarbazine ± involved-field or consolidation radiotherapy. Positron emission tomography scan was performed at baseline and after two cycles of chemotherapy. Treatment was not changed according to the results of the interim scan. An international panel of six expert reviewers independently...

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

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

    2007-01-01

    A general hindrance to progress in adoptive cellular therapy is the lack of detailed knowledge of the fate of transferred cells in the body of the recipient. In this study, we present a novel technique for tracking of 124I-labeled cells in situ, which combines the high spatial resolution of magne......A general hindrance to progress in adoptive cellular therapy is the lack of detailed knowledge of the fate of transferred cells in the body of the recipient. In this study, we present a novel technique for tracking of 124I-labeled cells in situ, which combines the high spatial resolution...... of magnetic resonance imaging with the high sensitivity and spatial accuracy of positron emission tomography. We have used this technique, together with determination of tissue radioactivity, flow cytometry, and microscopy, to characterize and quantitate the specific accumulation of transferred CD8+ T cells...... was determined by flow cytometry each day for 8 consecutive days after adoptive transfer. From low levels 1 day after injection, their number gradually increased until day 5 when an average of 3.3x10(6) SIINFEKL-specific cells per gram tumor tissue was found. By applying the combined positron emission tomography/magnetic...

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

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

    1990-01-01

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

  2. The positrons emission tomography in cardiology on expecting for the rubidium 82; La tomographie par emission de positons en cardiologie en attendant le rubidium-82

    Agostini, D. [Societe Francaise de Cardiologie Nucleaire et IRM, 75 - Paris (France)

    2005-11-15

    The positron emission tomography in cardiology has an important place in France. A new tracer, the rubidium 82 can be used for the detection of myocardium ischemia among the patients where the SPECT was ineffective or not very useful, it will be necessary to propose a permit to market the tracer in the two next years.Recently, the Food drug administration in Usa has allowed the repayment of the rubidium 82 for the myocardium detection as normal or abnormal in the post myocardium infarction. (N.C.)

  3. Positron emission particle tracking - a technique for studying flow within engineering equipment

    Parker, D.J.; Hawkesworth, M.R.; McNeil, P. (School of Physics and Space Research, Birmingham (United Kingdom)); Broadbent, C.J. (School of Chemical Engineering, Birmingham (United Kingdom)); Fowles, P. (School of Chemistry, Univ. Birmingham (United Kingdom))

    1993-03-10

    The use of the Birmingham positron camera for tracking positron-emitting particles within engineering structures has been investigated, using particles containing typically 4 MBq (100 [mu]Ci) [sup 18]F or [sup 22]Na. An algorithm for discarding [gamma]-ray trajectories corrupted by scattering, etc., and using the remaining trajectories to compute the particle's location in three dimensions has been developed, and its performance explained. A slowly moving particle can be located to within 1 mm several times per second, while a particle moving at 1 ms[sup -1] can be located to within 5 mm 50 times per second, through a considerable thickness of surrounding material. An example of results obtained from tracking a particle in a rotating drum of powder illustrates the potential value of the technique. (orig.).

  4. Photon emission by ultra-relativistic positrons in crystalline undulators: the high-energy regime

    Krause, W; Solov'yov, A V; Greiner, W

    2015-01-01

    This paper discusses the undulator radiation emitted by high-energy positrons during planar channeling in periodically bent crystals. We demonstrate that the construction of the undulator for positrons with energies of 10 GeV and above is only possible if one takes into account the radiative energy losses. The frequency of the undulator radiation depends on the energy of the particle. Thus the decrease of the particle's energy during the passage of the crystal should result in the destruction of the undulator radiation regime. However, we demonstrate that it is possible to avoid the destructive influence of the radiative losses on the frequency of the undulator radiation by the appropriate variation of the shape of the crystal channels. We also discuss a method by which, to our mind, it would be possible to prepare the crystal with the desired properties of its channels.

  5. The potential of positron emission tomography for intratreatment dynamic lung tumor tracking: A phantom study

    Yang, Jaewon [Department of Electrical Engineering, Stanford University, Stanford, California 94305 and Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Yamamoto, Tokihiro [Department of Radiation Oncology, University of California Davis, Sacramento, California 95817 (United States); Mazin, Samuel R. [RefleXion Medical, Inc., Burlingame, California 94010 (United States); Graves, Edward E. [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Keall, Paul J., E-mail: paul.keall@sydney.edu.au [Radiation Physics Laboratory, University of Sydney, Sydney, NSW 2006 (Australia)

    2014-02-15

    Purpose: This study aims to evaluate the potential and feasibility of positron emission tomography for dynamic lung tumor tracking during radiation treatment. The authors propose a center of mass (CoM) tumor tracking algorithm using gated-PET images combined with a respiratory monitor and investigate the geometric accuracy of the proposed algorithm. Methods: The proposed PET dynamic lung tumor tracking algorithm estimated the target position information through the CoM of the segmented target volume on gated PET images reconstructed from accumulated coincidence events. The information was continuously updated throughout a scan based on the assumption that real-time processing was supported (actual processing time at each frame ≈10 s). External respiratory motion and list-mode PET data were acquired from a phantom programmed to move with measured respiratory traces (external respiratory motion and internal target motion) from human subjects, for which the ground truth target position was known as a function of time. The phantom was cylindrical with six hollow sphere targets (10, 13, 17, 22, 28, and 37 mm in diameter). The measured respiratory traces consisted of two sets: (1) 1D-measured motion from ten healthy volunteers and (2) 3D-measured motion from four lung cancer patients. The authors evaluated the geometric accuracy of the proposed algorithm by quantifying estimation errors (Euclidean distance) between the actual motion of targets (1D-motion and 3D-motion traces) and CoM trajectories estimated by the proposed algorithm as a function of time. Results: The time-averaged error of 1D-motion traces over all trajectories of all targets was 1.6 mm. The error trajectories decreased with time as coincidence events were accumulated. The overall error trajectory of 1D-motion traces converged to within 2 mm in approximately 90 s. As expected, more accurate results were obtained for larger targets. For example, for the 37 mm target, the average error over all 1D

  6. Fast 3D-EM reconstruction using Planograms for stationary planar positron emission mammography camera.

    Motta, A; Guerra, A Del; Belcari, N; Moehrs, S; Panetta, D; Righi, S; Valentini, D

    2005-12-01

    At the University of Pisa we are building a PEM prototype, the YAP-PEM camera, consisting of two opposite 6 x 6 x 3 cm3 detector heads of 30 x 30 YAP:Ce finger crystals, 2 x 2 x 30 mm3 each. The camera will be equipped with breast compressors. The acquisition will be stationary. Compared with a whole body PET scanner, a planar Positron Emission Mammography (PEM) camera allows a better, easier and more flexible positioning around the breast in the vicinity of the tumor: this increases the sensitivity and solid angle coverage, and reduces cost. To avoid software rejection of data during the reconstruction, resulting in a reduced sensitivity, we adopted a 3D-EM reconstruction which uses all of the collected Lines Of Response (LORs). This skips the PSF distortion given by data rebinning procedures and/or Fourier methods. The traditional 3D-EM reconstruction requires several times the computation of the LOR-voxel correlation matrix, or probability matrix {p(ij)}; therefore is highly time-consuming. We use the sparse and symmetry properties of the matrix {p(ij)} to perform fast 3D-EM reconstruction. Geometrically, a 3D grid of cubic voxels (FOV) is crossed by several divergent 3D line sets (LORs). The symmetries occur when tracing different LORs produces the same p(ij) value. Parallel LORs of different sets cross the FOV in the same way, and the repetition of p(ij) values depends on the ratio between the tube and voxel sizes. By optimizing this ratio, the occurrence of symmetries is increased. We identify a nucleus of symmetry of LORs: for each set of symmetrical LORs we choose just one LOR to be put in the nucleus, while the others lie outside. All of the possible p(ij) values are obtainable by tracking only the LORs of this nucleus. The coordinates of the voxels of all of the other LORs are given by means of simple translation rules. Before making the reconstruction, we trace the LORs of the nucleus to find the intersecting voxels, whose p(ij) values are computed and

  7. Measured dose rate constant from oncology patients administered 18F for positron emission tomography

    Quinn, Brian; Holahan, Brian; Aime, Jean; Humm, John; St Germain, Jean; Dauer, Lawrence T. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States) and Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States) and Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065 (United States)

    2012-10-15

    Purpose: Patient exposure rate measurements verify published patient dose rate data and characterize dose rates near 2-18-fluorodeoxyglucose ({sup 18}F-FDG) patients. A specific dose rate constant based on patient exposure rate measurements is a convenient quantity that can be applied to the desired distance, injection activity, and time postinjection to obtain an accurate calculation of cumulative external radiation dose. This study reports exposure rates measured at various locations near positron emission tomography (PET) {sup 18}F-FDG patients prior to PET scanning. These measurements are normalized for the amount of administered activity, measurement distance, and time postinjection and are compared with other published data. Methods: Exposure rates were measured using a calibrated ionization chamber at various body locations from 152 adult oncology patients postvoid after a mean uptake time of 76 min following injection with a mean activity of 490 MBq {sup 18}F-FDG. Data were obtained at nine measurement locations for each patient: three near the head, four near the chest, and two near the feet. Results: On contact with, 30 cm superior to and 30 cm lateral to the head, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.482 (0.511), 0.135 (0.155), and 0.193 (0.223) {mu}Sv/MBq h, respectively. On contact with, 30 cm anterior to, 30 cm lateral to and 1 m anterior to the chest, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.623 (0.709), 0.254 (0.283), 0.190 (0.218), and 0.067 (0.081) {mu}Sv/MBq h respectively. 30 cm inferior and 30 cm lateral to the feet, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.024 (0.022) and 0.039 (0.044) {mu}Sv/MBq h, respectively. Conclusions: The measurements for this study support the use of 0.092 {mu}Sv m{sup 2}/MBq h as a reasonable representation of the dose rate anterior from the chest of

  8. Three-dimensional performance of a small-diameter positron emission tomograph

    Bloomfield, P.M.; Myers, R.; Hume, S.P.; Spinks, T.J.; Lammertsma, A.A.; Jones, T. [PET Methodology Group, Cyclotron Unit, MRC Clinical Sciences Centre, Hammersmith Hospital, London (United Kingdom)

    1997-02-01

    Recently, the initial 2D physical characterization of a small-diameter positron emission tomograph, designed specifically for scanning of small laboratory animals, was reported. The physical characteristics of the tomograph operating in 3D mode have now been measured and compared to those obtained in 2D mode. In 3D, the transaxial resolution was measured as 2.4{+-}0.1 mm full width at half maximum (FWHM) and 6.7{+-}1.1 mm full width t tenth maximum (FWTM) at the centre of the transaxial field of view (FOV). these values degraded to 4.5{+-}0.3 mm (tangential) and 6.6{+-}0.3 mm radial) FWHM and 10.6{+-}1.6 mm (tangential) and 11.2{+-}2.1 mm (radial) WTM, respectively, at a radial distance of 40 mm from the centre of the transaxial FOV. The axial resolution was measured as 4.6{+-}0.1 mm FWHM and 5.0{+-}0.5 mm FWTM at the centre of the transaxial FOV, increasing to .0{+-}0.1 mm FWHM and 18.8{+-}3.7 mm FWTM at a radial distance of 40 mm from the centre of the transaxial FOV. These resolutions are similar to those obtained for the tomograph operating in 2D mode. The sensitivity of the tomograph operating in 3D was 4.31x10{sup 4} counts s{sup -1} MBq{sup -1} at 250-850 keV compared to 0.995x10{sup 4} counts s{sup -1} MBq{sup -1} in 2D at the same energy thresholds. In this energy window the noise equivalent count rate peaked at .1x10{sup 4} counts s{sup -1}, compared to 1.03x10{sup 4} counts s{sup -1} in 2D. A scatter reaction of 30.2% at 250-850 keV was measured for a {sup 18}F line source centred n a 60 mm diameter water filled phantom in 3D, compared to 31.0% in 2D for the same scanning geometry and energy thresholds. A comparison was made between 2D and 3D kinetic analyses for a group of five anesthetized rats canned using [{sup 11}C] SCH 23390, a marker of dopamine D{sub 1} receptors. The integrity of the results was maintained between 2D and 3D data sets, though n 3D there was a significant reduction in the standard error of the fitted parameter. The results

  9. Depressed cerebral oxygen metabolism in patients with chronic renal failure. A positron emission tomography study

    Hirakata, Hideki; Kanai, Hidetoshi; Nakane, Hiroshi; Fujii, Ken-ichiro; Hirakata, Eriko; Ibayashi, Setsuro; Kuwabara, Yasuo; Deenitchna, S.S.; Fujishima, Masatoshi [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences

    2001-07-01

    In order to elucidate brain oxygen metabolism in uremic patients, the regional cerebral blood flow (rCBF), oxygen extraction (rOEF) and oxygen metabolism (rCMRO{sub 2}) were measured by positron emission tomography (PET) in both 10 hemodialysis patients (HD: male [m]/female [f]=2/8, age of 49{+-}3 [SEM] years old, HD duration of 113{+-}26 months) and 13 pre-dialysis renal failure patients (CRF: m/f=10/3, age of 61{+-}2 years old, serum creatinine (SCr) of 6.3{+-}1.0 mg/dl). Data were compared with 20 non-uremic subjects (Control: m/f=7/13, age of 62{+-}2 years old, SCr of 0.9{+-}0.1 mg/dl). They had no neurological abnormalities, congestive heart failure, history of cerebrovascular accident, diabetes mellitus, or symptomatic brain lesion on magnetic resonance imaging. The age of HD was significantly younger than the other groups (p<0.02) and the hemoglobin (Hb) levels in both HD (10.5{+-}0.5 g/dl) and CRF (9.8{+-}0.9) were significantly lower than that in Control (13.3{+-}0.3) (p<0.02). In the hemisphere, rCMRO{sub 2} in both HD (1.82{+-}0.10 ml/min/100 g) and CRF (1.95{+-}0.09) showed significantly lower values as compared to Control (2.23{+-}0.05) (p<0.01, respectively). Hemispheric rCBF in HD (35.6{+-}2.1 ml/100 g/min) and in CRF (36.1{+-}2.1) were not different from that in Control (31.8{+-}1.4). Hemispheric rOEF in CRF (45.7{+-}1.6%) was significantly higher than that in Control (40.5{+-}1.2%) (p<0.02), but that in HD (43.7{+-}1.9%) did not increase significantly. These tendencies were similar in all regions of interest, especially in the cerebral cortices, but not in the cerebellum. All PET parameters in the frontal cortices tended to show the lowest value in renal failure patients. For all HD patients, rCBF in both the frontal cortex and the white matter correlated inversely with HD duration (frontal cortex: r=-0.649, p<0.05; white matter: r=-0.706, p<0.02). Based on these data, it is concluded that brain oxygen metabolism is depressed in renal failure

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

    Warburton, E

    1998-07-01

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

  11. {sup 18}F-Fluoromisonidazole positron emission tomography may differentiate glioblastoma multiforme from less malignant gliomas

    Hirata, Kenji; Shiga, Tohru; Tamaki, Nagara [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo, Hokkaido (Japan); Terasaka, Shunsuke; Kobayashi, Hiroyuki; Yamaguchi, Shigeru; Houkin, Kiyohiro [Graduate School of Medicine, Hokkaido University, Department of Neurosurgery, Sapporo (Japan); Hattori, Naoya [Graduate School of Medicine, Hokkaido University, Department of Molecular Imaging, Sapporo (Japan); Magota, Keiichi [Hokkaido University Hospital, Department of Radiology, Sapporo (Japan); Tanaka, Shinya [Graduate School of Medicine, Hokkaido University, Department of Cancer Pathology, Sapporo (Japan); Kuge, Yuji [Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan)

    2012-05-15

    Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor and its prognosis is significantly poorer than those of less malignant gliomas. Pathologically, necrosis is one of the most important characteristics that differentiate GBM from lower grade gliomas; therefore, we hypothesized that {sup 18}F fluoromisonidazole (FMISO), a radiotracer for hypoxia imaging, accumulates in GBM but not in lower grade gliomas. We aimed to evaluate the diagnostic value of FMISO positron emission tomography (PET) for the differential diagnosis of GBM from lower grade gliomas. This prospective study included 23 patients with pathologically confirmed gliomas. All of the patients underwent FMISO PET and {sup 18}F-fluorodeoxyglucose (FDG) PET within a week. FMISO images were acquired 4 h after intravenous administration of 400 MBq of FMISO. Tracer uptake in the tumor was visually assessed. Lesion to normal tissue ratios and FMISO uptake volume were calculated. Of the 23 glioma patients, 14 were diagnosed as having GBM (grade IV glioma in the 2007 WHO classification), and the others were diagnosed as having non-GBM (5 grade III and 4 grade II). In visual assessment, all GBM patients showed FMISO uptake in the tumor greater than that in the surrounding brain tissues, whereas all the non-GBM patients showed FMISO uptake in the tumor equal to that in the surrounding brain tissues (p {<=} 0.001). One GBM patient was excluded from FDG PET study because of hyperglycemia. All GBM patients and three of the nine (33%) non-GBM patients showed FDG uptake greater than or equal to that in the gray matter. The sensitivity and specificity for diagnosing GBM were 100 and 100% for FMISO, and 100 and 66% for FDG, respectively. The lesion to cerebellum ratio of FMISO uptake was higher in GBM patients (2.74 {+-} 0.60, range 1.71-3.81) than in non-GBM patients (1.22 {+-} 0.06, range 1.09-1.29, p {<=} 0.001) with no overlap between the groups. The lesion to gray matter ratio of FDG was also

  12. (/sup 11/C)clorgyline and (/sup 11/C)-L-deprenyl and their use in measuring functional monoamine oxidase activity in the brain using positron emission tomography

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

    1986-04-17

    This invention involves a new strategy for imaging the activity of the enzyme monoamine oxidase in the living body by using /sup 11/C-labeled enzyme inhibitors which bind irreversibly to an enzyme as a result of catalysis. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

  13. The fast method of Cu-porphyrin complex synthesis for potential use in positron emission tomography imaging

    Kilian, Krzysztof; Pęgier, Maria; Pyrzyńska, Krystyna

    2016-04-01

    Porphyrin based photosensitizers are useful agents for photodynamic therapy and fluorescence imaging of cancer. Additionally, porphyrins are excellent metal chelators, forming stable metalo-complexes and 64Cu isotope can serve as a positron emitter (t1/2 = 12.7 h). The other advantage of 64Cu is its decay characteristics that facilitates the use of 64Cu-porphyrin complex as a therapeutic agent. Thus, 64Cu chelation with porphyrin photosensitizer may become a simple and versatile labeling strategy for clinical positron emission tomography. The present study reports a convenient method for the synthesis of Cu complex with tetrakis(4-carboxyphenyl)porphyrin (TCPP). The experimental conditions for labeling, such as the metal-to-ligand molar ratio, pH and time of reaction were optimized to achieve a high complexation efficiency in a short period of time as possible. In order to accelerate the metallation, the use of substitution reactions of cadmium or lead porphyrin and the presence of reducing agent, such as ascorbic acid, hydroxylamine and flavonoid - morin, were evaluated. The optimum conditions for the synthesis of the copper complex were borate buffer at pH 9 with the addition of 10-fold molar excess, with respect to Cu2 + ions and TCPP and ascorbic acid which resulted in reduction of the reaction time from 30 min to below 1 min.

  14. The fast method of Cu-porphyrin complex synthesis for potential use in positron emission tomography imaging.

    Kilian, Krzysztof; Pęgier, Maria; Pyrzyńska, Krystyna

    2016-04-15

    Porphyrin based photosensitizers are useful agents for photodynamic therapy and fluorescence imaging of cancer. Additionally, porphyrins are excellent metal chelators, forming stable metalo-complexes and (64)Cu isotope can serve as a positron emitter (t1/2=12.7h). The other advantage of (64)Cu is its decay characteristics that facilitates the use of (64)Cu-porphyrin complex as a therapeutic agent. Thus, (64)Cu chelation with porphyrin photosensitizer may become a simple and versatile labeling strategy for clinical positron emission tomography. The present study reports a convenient method for the synthesis of Cu complex with tetrakis(4-carboxyphenyl)porphyrin (TCPP). The experimental conditions for labeling, such as the metal-to-ligand molar ratio, pH and time of reaction were optimized to achieve a high complexation efficiency in a short period of time as possible. In order to accelerate the metallation, the use of substitution reactions of cadmium or lead porphyrin and the presence of reducing agent, such as ascorbic acid, hydroxylamine and flavonoid - morin, were evaluated. The optimum conditions for the synthesis of the copper complex were borate buffer at pH9 with the addition of 10-fold molar excess, with respect to Cu(2+) ions and TCPP and ascorbic acid which resulted in reduction of the reaction time from 30 min to below 1 min.

  15. CA19-9 as a Potential Target for Radiolabeled Antibody-Based Positron Emission Tomography of Pancreas Cancer

    Mark D. Girgis

    2011-01-01

    Full Text Available Introduction. Sensitive and specific imaging of pancreas cancer are necessary for accurate diagnosis, staging, and treatment. The vast majority of pancreas cancers express the carbohydrate tumor antigen CA19-9. The goal of this study was to determine the potential to target CA19-9 with a radiolabeled anti-CA19-9 antibody for imaging pancreas cancer. Methods. CA19-9 was quantified using flow cytometry on human pancreas cancer cell lines. An intact murine anti-CA19-9 monoclonal antibody was labeled with a positron emitting radionuclide (Iodine-124 and injected into mice harboring antigen positive and negative xenografts. MicroPET/CT were performed at successive time intervals (72 hours, 96 hours, 120 hours after injection. Radioactivity was measured in blood and tumor to provide objective confirmation of the images. Results. Antigen expression by flow cytometry revealed approximately 1.3×106 CA19-9 antigens for the positive cell line and no expression in the negative cell line. Pancreas xenograft imaging with Iodine-124-labeled anti-CA19-9 mAb demonstrated an average tumor to blood ratio of 5 and positive to negative tumor ratio of 20. Conclusion. We show in vivo targeting of our antigen positive xenograft with a radiolabeled anti-CA19-9 antibody. These data demonstrate the potential to achieve anti-CA19-9 antibody based positron emission tomography of pancreas cancer.

  16. Validity of using a 3-dimensional PET scanner during inhalation of 15O-labeled oxygen for quantitative assessment of regional metabolic rate of oxygen in man.

    Hori, Yuki; Hirano, Yoshiyuki; Koshino, Kazuhiro; Moriguchi, Tetsuaki; Iguchi, Satoshi; Yamamoto, Akihide; Enmi, Junichiro; Kawashima, Hidekazu; Zeniya, Tsutomu; Morita, Naomi; Nakagawara, Jyoji; Casey, Michael E; Iida, Hidehiro

    2014-09-21

    Use of 15O labeled oxygen (15O2) and positron emission tomography (PET) allows quantitative assessment of the regional metabolic rate of oxygen (CMRO2) in vivo, which is essential to understanding the pathological status of patients with cerebral vascular and neurological disorders. The method has, however, been challenging, when a 3D PET scanner is employed, largely attributed to the presence of gaseous radioactivity in the trachea and the inhalation system, which results in a large amount of scatter and random events in the PET assessment. The present study was intended to evaluate the adequacy of using a recently available commercial 3D PET scanner in the assessment of regional cerebral radioactivity distribution during an inhalation of 15O2. Systematic experiments were carried out on a brain phantom. Experiments were also performed on a healthy volunteer following a recently developed protocol for simultaneous assessment of CMRO2 and cerebral blood flow, which involves sequential administration of 15O2 and C15O2. A particular intention was to evaluate the adequacy of the scatter-correction procedures. The phantom experiment demonstrated that errors were within 3% at the practically maximum radioactivity in the face mask, with the greatest radioactivity in the lung. The volunteer experiment demonstrated that the counting rate was at peak during the 15O gas inhalation period, within a verified range. Tomographic images represented good quality over the entire FOV, including the lower part of the cerebral structures and the carotid artery regions. The scatter-correction procedures appeared to be important, particularly in the process to compensate for the scatter originating outside the FOV. Reconstructed images dramatically changed if the correction was carried out using inappropriate procedures. This study demonstrated that accurate reconstruction could be obtained when the scatter compensation was appropriately carried out. This study also suggested the

  17. Diagnostic role of 18F-fluorodeoxyglucose positron emission tomography for follicular lymphoma with gastrointestinal involvement

    Masaya Iwamuro; Hiroyuki Okada; Katsuyoshi Takata; Katsuji Shinagawa; Shigeatsu Fujiki; Junji Shiode; Atsushi Imagawa

    2012-01-01

    AIM:To investigate the capacity for 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)to evaluate patients with gastrointestinal lesions of follicular lymphoma.@@METHODS:This retrospective case series consisted of 41 patients with follicular lymphoma and gastrointestinal involvement who underwent 18F-FDG-PET and endoscopic evaluations at ten different institutions between November 1996 and October 2011.Data for endoscopic,radiological,and biological examinations performed were retrospectively reviewed from clinical records.A semi-quantitative analysis of 18F-FDG uptake was performed for each involved area by calculating the maximum standardized uptake value (SUVmax).Based on the positivity of 18F-FDG uptake in the gastrointestinal lesions analyzed,patients were subdivided into two groups.To identify potential predictive factors for 18F-FDG positivity,these two groups were compared with respect to gender,age at diagnosis of lymphoma,histopathological grade,pattern of follicular dendritic cells,mitotic rate,clinical stage,soluble interleukin-2 receptor levels detected by 18F-FDG-PET,lactate dehydrogenase (LDH) levels,hemoglobin levelsbone marrow involvement,detectability of gastrointestinal lesions by computed tomography (CT) scanningand follicular lymphoma international prognostic index (FLIPI) risk.@@RESULTS:Involvement of follicular lymphoma in the stomach,duodenum,jejunum,ileum,cecum,colon,and rectum was identified in 1,34,6,3,2,3,and 6patients,respectively.No patient had esophageal involvement.In total,19/41 (46.3%) patients exhibited true-positive 18F-FDG uptake in the lesions present in their gastrointestinal tract.In contrast,false-negative 18F-FDG uptake was detected in 24 patients (58.5%),while false-positive 18F-FDG uptake was detected in 5 patients (12.2%).In the former case,2/19 patients had both 18F-FDG-positive lesions and 18F-FDG-negative lesions in the gastrointestinal tract.In patients with 18F-FDG avidity,the SUVmax value of

  18. Sensitive determination of specific radioactivity of positron emission tomography radiopharmaceuticals by radio high-performance liquid chromatography with fluorescence detection

    Nakao, Ryuji [Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan)], E-mail: nakaor@nirs.go.jp; Furutsuka, Kenji [Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Sumitomo Accelerator Service, Tokyo 141-8686 (Japan); Yamaguchi, Masatoshi [Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180 (Japan); Suzuki, Kazutoshi [Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan)

    2008-10-15

    A sensitive quality control method is often required in positron emission tomography (PET) radiopharmaceutical analysis due to the high specific radioactivity of synthetic products. The applicability of a radio high-performance liquid chromatography (HPLC) method with fluorescence detection was evaluated for a wide variety of PET radiopharmaceuticals. In 29 different radiopharmaceuticals studied, 20 compounds exhibited native fluorescence. These properties enabled sensitive determination of their chemical masses by direct fluorimetric detection after separation by HPLC. For some substances, detection limits were below nanograms per milliliter level, at least 40 times better than current UV absorbance detection. Sufficient reproducibility and linearity were obtained for the analysis of pharmaceutical fluid. Post-column fluorimetric derivatization was also established for the quantitative determination of FDG and ClDG in [{sup 18}F]FDG samples. These methods could be applied successfully to the analysis of PET radiopharmaceuticals with ultra-high specific radioactivity.

  19. Novel Radioligands for Cyclic Nucleotide Phosphodiesterase Imaging with Positron Emission Tomography: An Update on Developments Since 2012

    Susann Schröder

    2016-05-01

    Full Text Available Cyclic nucleotide phosphodiesterases (PDEs are a class of intracellular enzymes that inactivate the secondary messenger molecules, cyclic adenosine monophosphate (cAMP and cyclic guanosine monophosphate (cGMP. Thus, PDEs regulate the signaling cascades mediated by these cyclic nucleotides and affect fundamental intracellular processes. Pharmacological inhibition of PDE activity is a promising strategy for treatment of several diseases. However, the role of the different PDEs in related pathologies is not completely clarified yet. PDE-specific radioligands enable non-invasive visualization and quantification of these enzymes by positron emission tomography (PET in vivo and provide an important translational tool for elucidation of the relationship between altered expression of PDEs and pathophysiological effects as well as (pre-clinical evaluation of novel PDE inhibitors developed as therapeutics. Herein we present an overview of novel PDE radioligands for PET published since 2012.

  20. A Mouse Positron Emission Tomography Study of the Biodistribution of Gold Nanoparticles with Different Surface Coatings Using Embedded Copper-64

    Frellsen, Anders Floor; Hansen, Anders Elias; Jølck, Rasmus Irming

    2016-01-01

    By taking advantage of the ability of (64)Cu to bind non-specifically to gold surfaces, we have developed a new methodology to embed this radionuclide inside gold nanoparticles (AuNPs). (64)Cu enables the in vivo imaging of AuNPs by positron emission tomography (PET). AuNPs have a multitude of uses...... within health technology and are useful tools for general nanoparticle research. (64)Cu-AuNPs were prepared by incubating AuNP seeds with (64)Cu(2+), followed by the entrapment of the radionuclide by grafting a second layer of gold on the surface. This resulted in radiolabeling efficiencies of 53 ± 6......%. The radiolabel showed excellent stability when challenging with EDTA for two days (>95% radioactivity retention) and showed no loss of (64)Cu when incubated with 50% mouse serum for two days. The methodology was chelator-free, and circumvents traditional concerns over chelator instability and altered Au...

  1. Diagnostic efficacy of bone scintigraphy, magnetic resonance imaging, and positron emission tomography in bone metastases of myxoid liposarcoma.

    Conill, Carlos; Setoain, Xavier; Colomo, Luis; Palacín, Antonio; Combalia-Aleu, Andreu; Pomés, Jaime; Marruecos, Jordi; Vargas, Mauricio; Maurel, Joan

    2008-03-01

    Myxoid liposarcomas (MLS) have a tendency to metastasize to unusual sites. We report an unusual case of bone metastases not detected by bone scan and neither by fluorodeoxyglucose positron emission tomography (PET-FDG) and successfully identified with magnetic resonance imaging (MRI) in a patient with metachronic MLS. Histopathological examination of the primary tumor evidenced a tumor with unfavorable prognostic markers, and the biopsy of an iliac bone lesion confirmed the diagnosis of metastatic disease. On histological grounds, the tumor showed features of a more differentiated neoplasm without foci of round cells or necrosis in the latter. MRI allowed the identification of disseminated disease compared to computed tomography (CT) and PET scans. Thus, because of the heterogeneous histological features of MLS and the biological behavior of the disease, a combined approach of FDGPET-CT and MRI, may allow a more accurate staging of soft tissue sarcomas.

  2. A comparison of positron emission particle tracking (PEPT) methods for analysis of a tube-in-shell heat exchanger

    Wiggins, Cody; Patel, Nitant; Ruggles, Arthur

    2016-03-01

    A positron emission particle tracking (PEPT) study of a stainless steel tube-in-shell heat exchanger is performed. Studies are performed using two different energy window settings. A new multiple particle tracking technique is introduced and used in this analysis. Results are compared to those obtained with previously established multiple particle tracking technique. Both techniques are found to be capable of flow imaging through opaque surfaces. No significant difference is observed between energy window settings using either method. Results from both methods are found to be qualitatively similar; however, it is observed that the new method exhibits consistently lower measurement uncertainty across the field of view of the scanner and is robust against the adverse effects of stationary particles in the flow field.

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

    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.

  4. Magnetic resonance imaging-guided attenuation and scatter corrections in three-dimensional brain positron emission tomography

    Zaidi, H; Slosman, D O

    2003-01-01

    Reliable attenuation correction represents an essential component of the long chain of modules required for the reconstruction of artifact-free, quantitative brain positron emission tomography (PET) images. In this work we demonstrate the proof of principle of segmented magnetic resonance imaging (MRI)-guided attenuation and scatter corrections in 3D brain PET. We have developed a method for attenuation correction based on registered T1-weighted MRI, eliminating the need of an additional transmission (TX) scan. The MR images were realigned to preliminary reconstructions of PET data using an automatic algorithm and then segmented by means of a fuzzy clustering technique which identifies tissues of significantly different density and composition. The voxels belonging to different regions were classified into air, skull, brain tissue and nasal sinuses. These voxels were then assigned theoretical tissue-dependent attenuation coefficients as reported in the ICRU 44 report followed by Gaussian smoothing and additio...

  5. [18F]Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/Computed Tomography (CT) in Suspected Recurrent Breast Cancer

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

    2016-01-01

    PURPOSE: To prospectively investigate the diagnostic accuracy of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) with dual-time-point imaging, contrast-enhanced CT (ceCT), and bone scintigraphy (BS) in patients with suspected breast cancer recurrence....... PATIENTS AND METHODS: One hundred women with suspected recurrence of breast cancer underwent 1-hour and 3-hour FDG-PET/CT, ceCT, and BS within approximately 10 days. The study was powered to estimate the precision of the individual imaging tests. Images were visually interpreted using a four...... the receiver operating curve and higher sensitivity, specificity, and superior likelihood ratios. CONCLUSION: FDG-PET/CT was accurate in diagnosing recurrence in breast cancer patients. It allowed for distant recurrence to be correctly ruled out and resulted in only a small number of false-positive cases...

  6. Design of brain imaging agents for positron emission tomography: do large bioconjugates provide an opportunity for in vivo brain imaging?

    Schirrmacher, Ralf; Bernard-Gauthier, Vadim; Reader, Andrew; Soucy, Jean-Paul; Schirrmacher, Esther; Wängler, Björn; Wängler, Carmen

    2013-09-01

    The development of brain imaging agents for positron emission tomography and other in vivo imaging modalities mostly relies on small compounds of low MW as a result of the restricted transport of larger molecules, such as peptides and proteins, across the blood-brain barrier. Besides passive transport, only a few active carrier mechanisms, such as glucose transporters and amino acid transporters, have so far been exploited to mediate the accumulation of imaging probes in the brain. An important question for the future is whether some of the abundant active carrier systems located at the blood-brain barrier can be used to shuttle potential, but non-crossing, imaging agents into the brain. What are the biological and chemical constrictions toward such bioconjugates and is it worthwhile to persue such a delivery strategy?

  7. Optimization of [(11)C]raclopride positron emission tomographic rat studies: comparison of methods for image quantification.

    Torrent, Elia; Farré, Magí; Abasolo, Ibane; Millan, Olga; Llop, Jordi; Gispert, Juan Domingo; Ruiz, Alba; Pareto, Deborah

    2013-06-01

    The goal of this study was to compare different quantification approaches and reconstruction methods to estimate the binding potential in [11C]raclopride studies in rats. The final aim was to determine if the results obtained with short-acquisition scanning were comparable to the results obtained with long-acquistion (conventional) scanning. We analyzed two rat data sets: a baseline versus a pretreatment study (with cold raclopride) and a young versus an old animal group comparison. The study results support the contention that optimization of [11C]raclopride positron emission tomographic studies in rats by shortening the acquisition time is feasible. In addition, filtered backprojection is recommended as a reconstruction algorithm, although iterative methods may be more sensitive to detect within-group differences.

  8. Exploiting the Metal-Chelating Properties of the Drug Cargo for In Vivo Positron Emission Tomography Imaging of Liposomal Nanomedicines

    Edmonds, Scott; Volpe, Alessia; Shmeeda, Hilary;

    2016-01-01

    The clinical value of current and future nanomedicines can be improved by introducing patient selection strategies based on noninvasive sensitive whole-body imaging techniques such as positron emission tomography (PET). Thus, a broad method to radiolabel and track preformed nanomedicines...... such as liposomal drugs with PET radionuclides will have a wide impact in nanomedicine. Here, we introduce a simple and efficient PET radiolabeling method that exploits the metal-chelating properties of certain drugs (e.g., bisphosphonates such as alendronate and anthracyclines such as doxorubicin) and widely used...... ionophores to achieve excellent radiolabeling yields, purities, and stabilities with 89Zr, 52Mn, and 64Cu, and without the requirement of modification of the nanomedicine components. In a model of metastatic breast cancer, we demonstrate that this technique allows quantification of the biodistribution...

  9. The emerging role of whole-body 18F-fluorodeoxyglucose positron emission tomography in patients with sarcoidosis

    Silvia Taralli

    2012-01-01

    Full Text Available IntroductionThe purpose of this article is to examine the emerging role of whole-body positron emission tomography (PET with 18F-fluorodeoxyglucose (FDG in patients with sarcoidosis.Materials and methodsWe reviewed the literature on the use of FDG-PET in patients with sarcoidosis to identify how this technique is being applied in clinical practice.Results and discussionOur review shows that: 1 sarcoidosis is commonly associated with increased FDG uptake. Therefore, positive findings should be interpreted with caution when FDG-PET is being used to distinguish benign from malignant abnormalities; 2 FDG-PET seems to be a very useful molecular imaging method for staging sarcoidosis, identification of occult sites of involvement, guiding biopsy procedures, and monitoring patients’ responses to treatment; and 3 in patients with sarcoidosis, the diagnostic accuracy of FDG-PET is superior to that of 67Ga scintigraphy.

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

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

    1984-10-01

    It is well established that Creutzfeldt-Jakob disease (CJD) is caused by a slow infectious agent similar to the scrapie prion. However, the pathogenesis of this infection is poorly understood. Positron emission tomography (PET) was performed on a 54-year-old man with autopsy confirmed CJD using (18F)-2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. Temporal lobe hypometabolism with hemispheric asymmetry was observed. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer disease (AD). The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the possibility that AD may be caused by a slow infectious prion.

  11. Are we ready for positron emission tomography/computed tomography-based target volume definition in lymphoma radiation therapy?

    Yeoh, Kheng-Wei; Mikhaeel, N George

    2013-01-01

    Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) has become indispensable for the clinical management of lymphomas. With consistent evidence that it is more accurate than anatomic imaging in the staging and response assessment of many lymphoma subtypes, its utility continues to increase. There have therefore been efforts to incorporate PET/CT data into radiation therapy decision making and in the planning process. Further, there have also been studies investigating target volume definition for radiation therapy using PET/CT data. This article will critically review the literature and ongoing studies on the above topics, examining the value and methods of adding PET/CT data to the radiation therapy treatment algorithm. We will also discuss the various challenges and the areas where more evidence is required.

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

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

    2001-08-01

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

  13. Preclinical studies on [{sup 11}C]MPDX for mapping adenosine A{sub 1} receptors by positron emission tomography

    Ishiwata, Kiichi; Kimura, Yuichi; Oda, Keiichi; Kawamura, Kazunori; Ishii, Kenji; Senda, Michio [Tokyo Metropolitan Inst. of Gerontology (Japan). Positron Medical Center; Nariai, Tadashi; Wakabayashi, Shinichi [Tokyo Medical and Dental Univ. (Japan). School of Medicine; Shimada, Junichi [Kyowa Hakko Kogyo Co. Ltd., Tokyo (Japan). Pharmaceutical Research Inst.

    2002-09-01

    In previous in vivo studies with mice, rats and cats, we have demonstrated that [{sup 11}C]MPDX ([1-methyl-{sup 11}C]8-dicyclopropylmethyl-1-methyl-3-propylxanthine) is a potential radioligand for mapping adenosine A{sub 1} receptors of the brain by positron emission tomography (PET). In the present study, we performed a preclinical study. The radiation absorbed-dose by [{sup 11}C]MPDX in humans estimated from the tissue distribution in mice was low enough for clinical use, and the acute toxicity and mutagenicity of MPDX were not found. The monkey brain was clearly visualized by PET with [{sup 11}C]MPDX. We have concluded that [{sup 11}C]MPDX is suitable for mapping adenosine A{sub 1} receptors in the human brain by PET. (author)

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

    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.

  15. [18F]Fluorodeoxyglucose Positron Emission Tomography Reveals a Complete Remission of Refractory Metastatic Melanoma after Therapy with Ipilimumab

    Yordanova, Anna; Schlenkhoff, Carl; Palmedo, Holger; Essler, Markus; Ahmadzadehfar, Hojjat

    2017-01-01

    Ipilimumab (YERVOY) is a monoclonal CTLA-4-antibody with anti-tumor-immunogenic effect and is used to treat malignant melanoma. In this case study, we present [18F]Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) images of a 37-year-old woman with metastatic melanoma, who was previously treated with interferon-alpha therapy and dacarbazine and still progressed. After four cycles of ipilimumab, there was a complete remission of the disease with no evidence of vital, FDG-positive tumor tissue. The follow-up for a total of 1 year confirmed the therapeutic success. This report demonstrates that FDG-PET/CT is a reliable imaging method for response monitoring in metastatic melanoma treated with ipilimumab.

  16. One-step synthesis of 4-[(18) F]fluorobenzyltriphenylphosphonium cation for imaging with positron emission tomography.

    Zhang, Zhengxing; Zhang, Chengcheng; Lau, Joseph; Colpo, Nadine; Bénard, François; Lin, Kuo-Shyan

    2016-09-01

    4-[(18) F]Fluorobenzyltriphenylphosphonium cation ((18) F-FBnTP) is a promising negative membrane potential targeting positron emission tomography tracer. However, the reported multistep radiolabeling approach for the synthesis of (18) F-FBnTP poses a challenge for routine clinical applications. In this study, we demonstrated that (18) F-FBnTP can be prepared in good conversion yields (~60%, nondecay corrected) in just one step via a copper-mediated (18) F-fluorination reaction using a pinacolyl arylboronate precursor. In addition, our data suggest that (18) F-labeled (phosphonium) cations can be efficiently prepared via a copper-mediated (18) F-fluoronation by using triflate as the counterion.

  17. Importance of fluorodeoxyglucose-positron emission tomography (FDG-PET) and endoscopic ultrasonography parameters in predicting survival following surgery for esophageal cancer

    Omloo, J. M. T.; Sloof, G. W.; Boellaard, R.; Hoekstra, O. S.; Jager, P. L.; van Dullemen, H. M.; Fockens, P.; Plukker, J. T. M.; van Lanschot, J. J. B.

    2008-01-01

    Background and study aims: To assess the prognostic importance of standardized uptake value (SUV) for 18F-fluorodeoxyglucose (FDG) at positron emission tomography (PET) and of EUS parameters, in esophageal cancer patients primarily treated by surgery. Patients and methods: Between October 2002 and A

  18. Positron Emission Tomography studies with [C-11]PBR28 in the Healthy Rodent Brain : Validating SUV as an Outcome Measure of Neuroinflammation

    Toth, Miklos; Doorduin, Janine; Haggkvist, Jenny; Varrone, Andrea; Amini, Nahid; Halldin, Christer; Gulyas, Balazs

    2015-01-01

    Molecular imaging of the 18 kD Translocator protein (TSPO) with positron emission tomography (PET) is of great value for studying neuroinflammation in rodents longitudinally. Quantification of the TSPO in rodents is, however, quite challenging. There is no suitable reference region and the use of pl

  19. Coronary and peripheral endothelial function in HIV patients studied with positron emission tomography and flow-mediated dilation: relation to hypercholesterolemia

    Lebech, Anne-Mette; Kristoffersen, Ulrik; Wiinberg, Niels;

    2008-01-01

    BACKGROUND: The mechanisms underlying increased cardiovascular risk in HIV patients in antiretroviral therapy (ART) are not known. Our aim was to study the endothelial function of the coronary arteries by cardiac perfusion positron emission tomography (PET), in HIV patients with normal or high...... inhibitors (PI) compared to those not receiving PI (p cardiovascular risk, no sign of endothelial dysfunction was found not even...

  20. 18F-fluoro-deoxy-glucose-positron emission tomography/computed tomography in diagnosis of head and neck squamous cell carcinoma

    Rohde, Max; Dyrvig, Anne-Kirstine; Johansen, Jørgen;

    2014-01-01

    18F-fluoro-deoxy-glucose-positron emission tomography/computed tomography-scan (PET/CT) is used increasingly for detection of cancer. Precise diagnostic assessment of tumour extension in head and neck squamous cell carcinoma (HNSCC) is of critical importance for ensuring that patients receive...

  1. Contrast-enhanced fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography in mediastinal T-cell lymphoma with superior vena cava syndrome.

    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.

  2. Clinical Relevance of Incidental Prostatic Lesions on FDG-Positron Emission Tomography/Computerized Tomography-Should Patients Receive Further Evaluation?

    Reesink, Daan J; Fransen van de Putte, Elisabeth E; Vegt, Erik; De Jong, Jeroen; van Werkhoven, Erik; Mertens, Laura S; Bex, Axel; van der Poel, Henk G; van Rhijn, Bas W G; Horenblas, Simon; Meijer, Richard P

    2016-01-01

    PURPOSE: FDG ((18)F-fluoro-2-deoxy-D-glucose)-PET/CT (positron emission tomography)/(computerized tomography) is a widely used diagnostic tool for whole body imaging. Incidental prostatic uptake is often found on FDG-PET/CT. The objective of this study was to determine the clinical relevance of inci

  3. Species differences in blood-brain barrier transport of three positron emission tomography radioligands with emphasis on P-glycoprotein transport

    Syvänen, Stina; Lindhe, Orjan; Palner, Mikael;

    2009-01-01

    Species differences occur in the brain concentrations of drugs, but the reasons for these differences are not yet apparent. This study was designed to compare brain uptake of three radiolabeled P-glycoprotein (P-gp) substrates across species using positron emission tomography. Brain concentration...

  4. FDG-positron emission tomography/computed tomography and standardized uptake value in the primary diagnosis and staging of hilar cholangiocarcinoma

    A.T. Ruys; R.J. Bennink; H.L. van Westreenen; M.R. Engelbrecht; O.R. Busch; D.J. Gouma; T.M. van Gulik

    2011-01-01

    Background: The diagnosis and staging of hilar cholangiocarcinoma (HCCA) remain challenging despite recent advances in imaging. Little is known about the use of positron emission tomography/computed tomography (PET/CT) in HCCA. Objectives: This study aimed to evaluate the additional value of FDG-PET

  5. Species differences in blood-brain barrier transport of three positron emission tomography radioligands with emphasis on P-glycoprotein transport

    Syvanen, S.; Lindhe, O.; Palner, M.;

    2009-01-01

    Species differences occur in the brain concentrations of drugs, but the reasons for these differences are not yet apparent. This study was designed to compare brain uptake of three radiolabeled P-glycoprotein (P-gp) substrates across species using positron emission tomography. Brain concentrations...

  6. Comparison of five segmentation tools for 18F-fluoro-deoxy-glucose-positron emission tomography-based target volume definition in head and neck cancer.

    Schinagl, D.A.X.; Vogel, W.V.; Hoffmann, A.L.; Dalen, J.A. van; Oyen, W.J.G.; Kaanders, J.H.A.M.

    2007-01-01

    PURPOSE: Target-volume delineation for radiation treatment to the head and neck area traditionally is based on physical examination, computed tomography (CT), and magnetic resonance imaging. Additional molecular imaging with (18)F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) may imp

  7. Omitting radiotherapy in early positron emission tomography-negative stage I/II Hodgkin lymphoma is associated with an increased risk of early relapse

    Raemaekers, John M M; André, Marc P E; Federico, Massimo

    2014-01-01

    PURPOSE: Combined-modality treatment is standard treatment for patients with clinical stage I/II Hodgkin lymphoma (HL). We hypothesized that an early positron emission tomography (PET) scan could be used to adapt treatment. Therefore, we started the randomized EORTC/LYSA/FIL Intergroup H10 trial ...

  8. Use of high-resolution computed tomography and positron emission tomography/computed tomography in the management of stage IA adenocarcinoma.

    Miyata, Yoshihiro; Tsutani, Yasuhiro; Okada, Morihito

    2012-01-01

    Preoperative determination of malignant behavior is critical in choosing suitable therapeutic strategies such as sublobar resection for patients with small lung cancers. The aim of present review was to evaluate high-resolution computed tomography and fluorodeoxyglucose-positron emission tomography/computed tomography as tools for management of clinical stage IA adenocarcinoma.

  9. Evaluation of 4-[18F]fluorobenzoyl-FALGEA-NH2 as a positron emission tomography tracer for epidermal growth factor receptor mutation variant III imaging in cancer

    Denholt, Charlotte Lund; Binderup, Tina; Stockhausen, Marie-Thérése;

    2011-01-01

    This study describes the radiosynthesis, in vitro and in vivo evaluation of the novel small peptide radioligand, 4-[(18)F]fluorobenzoyl-Phe-Ala-Leu-Gly-Glu-Ala-NH(2,) ([(18)F]FBA-FALGEA-NH(2)) as a positron emission tomography (PET) tracer for imaging of the cancer specific epidermal growth factor...

  10. Reduction in coronary and peripheral vasomotor function in patients with HIV after initiation of antiretroviral therapy: a longitudinal study with positron emission tomography and flow-mediated dilation

    Kristoffersen, Ulrik Sloth; Wiinberg, Niels; Petersen, Claus Leth;

    2010-01-01

    The mechanisms underlying the increased cardiovascular risk in patients with HIV on antiretroviral therapy (ART) are not known. Our aim was to study the endothelial function of the coronary arteries by cardiac perfusion positron emission tomography (PET) in patients with HIV initiating ART...

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

    Posma, JL; Blanksma, PK; vanderWall, EE

    1996-01-01

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

  12. Spatio-temporal correlation between topographic ERP mapping and positron emission tomography

    Nagata, Ken [Research Inst. for Brain and Blood Vessels, Akita (Japan); Yaguchi, Kiyoshi

    2001-01-01

    Simultaneous measurement of PET excellent for spatial resolution and event-related potential (ERP) for temporal resolution was performed during the visual recognition task. Subjects were 12 normal adult males having given the informed consent. MRI was done for the morphological indicator of the PET results. PET was conducted by Shimadzu HEADTOME V after bolus injection of {sup 15}O-water to measure the cerebral blood flow (CBF). Electroencephalography was recorded simultaneously. The recognition task with the word, figure and human face was given during the measurements. At recognition of a famous person's face, ERP exhibited the negative peak around the occipital region after the latent time of 164 msec and PET exhibited the increased CBF in the gyruses of parahippocampus and fusiform, thus suggesting the correlation between electro-physiological activity and CBF change. (K.H.)

  13. Mapping of brain function with positron emission tomography for pathophysiological analysis of neurological disorders

    Nariai, Tadashi [Tokyo Medical and Dental Univ. (Japan). Graduate School

    2001-02-01

    The role of PET is discussed mainly through author's clinical experience in patients with brain lesions from the view of mapping of brain function. Procedure for PET concept in clinical practice is summarized. PET using tracers like [{sup 15}O]water and [{sup 18}F]fluorodeoxyglucose for mapping of the function has been used in combination with MRI, MEG (magnetoencephalography), SPECT and other imaging means for morphological identification. Actual those images before and after surgery are presented in cases of epilepsy, moyamoya disease, stegnosis of cervical artery, arteriovenous malformation and oligodendroglioma. Images of [{sup 11}C]flumazenil in epilepsies are also presented to show the neurological dysfunctions. PET evaluation of neurological functions is concluded to become more important in parallel with the advancement of therapeutics. (K.H.)

  14. The predictive role of interim positron emission tomography for Hodgkin lymphoma treatment outcome is confirmed using the interpretation criteria of the Deauville five-point scale.

    Gallamini, Andrea; Barrington, Sally F; Biggi, Alberto; Chauvie, Stephane; Kostakoglu, Lale; Gregianin, Michele; Meignan, Michel; Mikhaeel, George N; Loft, Annika; Zaucha, Jan M; Seymour, John F; Hofman, Michael S; Rigacci, Luigi; Pulsoni, Alessandro; Coleman, Morton; Dann, Eldad J; Trentin, Livio; Casasnovas, Olivier; Rusconi, Chiara; Brice, Pauline; Bolis, Silvia; Viviani, Simonetta; Salvi, Flavia; Luminari, Stefano; Hutchings, Martin

    2014-06-01

    A retrospective, international, multicenter study was undertaken to assess: (i) the prognostic role of 'interim' positron emission tomography performed during treatment with doxorubicin, bleomycin, vinblastine and dacarbazine in patients with Hodgkin lymphoma; and (ii) the reproducibility of the Deauville five-point scale for the interpretation of interim positron emission tomography scan. Two hundred and sixty patients with newly diagnosed Hodgkin lymphoma were enrolled. Fifty-three patients with early unfavorable and 207 with advanced-stage disease were treated with doxorubicin, bleomycin, vinblastine and dacarbazine ± involved-field or consolidation radiotherapy. Positron emission tomography scan was performed at baseline and after two cycles of chemotherapy. Treatment was not changed according to the results of the interim scan. An international panel of six expert reviewers independently reported the scans using the Deauville five-point scale, blinded to treatment outcome. Forty-five scans were scored as positive (17.3%) and 215 (82.7%) as negative. After a median follow up of 37.0 (2-110) months, 252 patients are alive and eight have died. The 3-year progression-free survival rate was 83% for the whole study population, 28% for patients with interim positive scans and 95% for patients with interim negative scans (Pinterim positron emission tomography scans for predicting treatment outcome were 0.73, 0.94, 0.94 and 0.73, respectively. Binary concordance amongst reviewers was good (Cohen's kappa 0.69-0.84). In conclusion, the prognostic role and validity of the Deauville five-point scale for interpretation of interim positron emission tomography scans have been confirmed by the present study.

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

    Leonard I. Wiebe

    2007-05-01

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

  16. Quantification of [{sup 11}C]GB67 binding to cardiac {alpha}{sub 1}-adrenoceptors with positron emission tomography: validation in pigs

    Park-Holohan, So-Jin; Turton, David R.; Hume, Susan P. [Hammersmith Hospital, Hammersmith Imanet Ltd., GE HealthCare, Cyclotron Building, London (United Kingdom); Asselin, Marie-Claude [Hammersmith Hospital, Hammersmith Imanet Ltd., GE HealthCare, Cyclotron Building, London (United Kingdom); The University of Manchester, Wolfson Molecular Imaging Centre, Manchester (United Kingdom); Williams, Sharron L.; Camici, Paolo G. [Hammersmith Hospital, MRC Clinical Sciences Centre, Cyclotron Building, London (United Kingdom); Rimoldi, Ornella E. [Hammersmith Hospital, MRC Clinical Sciences Centre, Cyclotron Building, London (United Kingdom); New York Medical College, Cardiovascular Research Institute Department of Medicine, Valhalla, NY (United States)

    2008-09-15

    An increase in human cardiac {alpha}{sub 1}-adrenoceptor ({alpha}{sub 1}-AR) density is associated with various diseases such as myocardial ischemia, congestive heart failure, hypertrophic cardiomyopathy and hypertension. Positron emission tomography (PET) with an appropriate radioligand offers the possibility of imaging receptor function in the normal and diseased heart. [{sup 11}C]GB67, an analogue of prazosin, has been shown in rats to have potential as a PET ligand with high selectivity to {alpha}{sub 1}-AR. However, {alpha}{sub 1}-AR density is up to ten times higher in rat heart compared to that in man. The aim of the present preclinical study was to extend the previous evaluation to a large mammal heart, where the {alpha}{sub 1}-AR density is comparable to man, and to validate a method for quantification before PET studies in man. Seven [{sup 11}C]GB67 PET studies, with weight-adjusted target dose of either 5.29 MBq kg{sup -1} (pilot, test-retest and baseline-predose studies) or 8.22 MBq kg{sup -1} (baseline-displacement studies), were performed in four anaesthetised pigs (39.5 {+-} 3.9 kg). Total myocardial volume of distribution (V{sub T}) was estimated under different pharmacological conditions using compartmental analysis with a radiolabelled metabolite-corrected arterial plasma input function. A maximum possible blocking dose of 0.12 {mu}mol kg{sup -1} of unlabeled GB67 was given 20 min before [{sup 11}C]GB67 administration in the predose study and 45 min after administration of [{sup 11}C]GB67 in the displacement study. In addition, [{sup 15}O]CO (3,000 MBq) and [{sup 15}O]H{sub 2}O, with weight adjusted target dose of 10.57 MBq kg{sup -1}, were also administered for estimation of blood volume recovery (RC) of the left ventricular cavity and myocardial perfusion (MBF), respectively. [{sup 11}C]GB67 V{sub T} values (in ml cm{sup -3}) were estimated to be 24.2 {+-} 5.5 (range, 17.3-31.3), 10.1 (predose) and 11.6 (displacement). MBF did not differ within

  17. Development and Operation of a High Resolution Positron Emission Tomography System to Perform Metabolic Studies on Small Animals.

    Hogan, Matthew John

    A positron emission tomography system designed to perform high resolution imaging of small volumes has been characterized. Two large area planar detectors, used to detect the annihilation gamma rays, formed a large aperture stationary positron camera. The detectors were multiwire proportional chambers coupled to high density lead stack converters. Detector efficiency was 8%. The coincidence resolving time was 500 nsec. The maximum system sensitivity was 60 cps/(mu)Ci for a solid angle of acceptance of 0.74(pi) St. The maximum useful coincidence count rate was 1500 cps and was limited by electronic dead time. Image reconstruction was done by performing a 3-dimensional deconvolution using Fourier transform methods. Noise propagation during reconstruction was minimized by choosing a 'minimum norm' reconstructed image. In the stationary detector system (with a limited angle of acceptance for coincident events) statistical uncertainty in the data limited reconstruction in the direction normal to the detector surfaces. Data from a rotated phantom showed that detector rotation will correct this problem. Resolution was 4 mm in planes parallel to the detectors and (TURN)15 mm in the normal direction. Compton scattering of gamma rays within a source distribution was investigated using both simulated and measured data. Attenuation due to scatter was as high as 60%. For small volume imaging the Compton background was identified and an approximate correction was performed. A semiquantitative blood flow measurement to bone in the leg of a cat using the ('18)F('-) ion was performed. The results were comparable to investigations using more conventional techniques. Qualitative scans using ('18)F labelled deoxy -D-glucose to assess brain glucose metabolism in a rhesus monkey were also performed.

  18. Positron emission tomography in digestive neuroendocrine tumors: choice of the tracer; Apport de la tomographie par emission de positons dans les tumeurs endocrines digestives: choix du traceur

    Taieb, D.; Tessonnier, L.; Mundler, O. [Centre Hospitalo-Universitaire de La Timone, Service Central de Biophysique et de Medecine Nucleaire, 13 - Marseille (France)

    2009-11-15

    Digestive endocrine tumors represent a heterogeneous group of neoplasm sharing common characteristics such as their high density of peptide receptors, their ability to take up amino acids and de-carboxylate them into biogenic amines and their low glycolytic activity. These features are used for nuclear imaging targeting. To date, somatostatin receptor scintigraphy is considered the 'gold standard' imaging procedure of well-differentiated tumors. Despite the significant contribution of SPECT/CT, the use of positron emission tomography imaging (PET) is growing rapidly. Three PET imaging modalities are currently available: {sup 68}Ga-labeled somatostatin analogs PET, {sup 18}F-dihydroxy-phenylalanine PET ({sup 18}F-DOPA) and {sup 18}F-deoxyglucose PET ({sup 18}F-F.D.G.). This article focuses on the current targets of molecular imaging and highlights the potential clinical applications of new targets. (authors)

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

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

    2008-10-15

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

  20. (/sup 11/C)methionine pancreatic scanning with positron emission computed tomography

    Syrota, A.; Comar, D.; Cerf, M.; Plummer, D.; Maziere, M.; Kellershohn, C.

    1979-07-01

    By the use of (/sup 11/C)methionine and positron computed tomography (PCT), images of the pancreas were obtained in 32 patients. The injection of between 10 and 20 mCi of this product enables four to six transverse sections to be obtained. Seventeen of the patients studied had no exocrine pancreatic disease, and in all these cases the pancreas was clearly visible. In four cases of pancreatic carcinoma and one of retroperitoneal tumor, there were abnormalities visible. In five cases of chronic pancreatitis, no pancreatic uptake was observed. In a sixth case, concentration was visible, but only in the head of the pancreas. One case of acute pancreatitis, which showed no concentration during the acute phase, returned to normal after recovery. When visible, the pancreas was easily located and distinguishable from the intestinal image, except in two cases that were uninterpretable for technical reasons. No false positive or negative was observed, but a differential diagnosis between cancer and pancreatitis was impossible.

  1. Evaluation of focal thyroid lesions incidentally detected in fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography images

    O Yaylali

    2014-01-01

    Full Text Available Background and Purpose: Increased uptake in the thyroid gland (TG is often identified as an incidental finding on the whole body fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT in non-thyroid cancer patients. Currently, there is no consensus on the appropriate approach for the management of these cases. Thyroid ultrasound, scintigraphy and fine-needle aspiration biopsy (FNAB are suggested to exclude malignant thyroid lesions. Our aim is to determine the importance of increased F-18-FDG uptake in the TG on positron emission tomography/computed tomography (PET/CT scans in patients who are being screened for various forms of non-thyroid cancer. Materials and Methods: We evaluated 2000 cases undergoing whole body PET/CT scanning between April 2011 and October 2012. The age, sex, type of primary cancer, maximum standardized uptake value (SUV max , size of the thyroid nodules and cervical lymph nodes (CLNs on 18 F-FDG PET/CT images and if available, the biopsy results were evaluated. Results: In total, 57 patients (23 men, 34 women, mean age ± standard deviation (SD, 60.89 ± 14 years showed an increased fluorine-18-fluorodeoxyglucose ( 18 F-FDG uptake by the TG (average SUV max : 4.07 ± 3.7. The CLNs were detected in 19/57 patients (33%. Only 20 cases (35% received FNAB. The final histopathological diagnosis was papillary thyroid carcinoma in seven patients (mean SUV max ± SD: 6.0 ± 5.43 and benign thyroid disease in seven patients (mean SUV max ± SD: 2.36 ± 0.63. The FNAB results were undetermined for six patients. Conclusion: Focal high 18 F-FDG uptake in the TG may be associated with an increased risk of malignancy, but the clinical significance is unclear. More data are needed to elucidate the role of the SUV in the differentiation of benign and malign thyroid lesions. If a focal increase in 18 F-FDG uptake in the TG on PET/CT is present, a prompt histopathological evaluation should be

  2. Recent development of positron annihilation methods

    Doyama, M

    2002-01-01

    When positron comes into solid or liquid, it moves in the matter and emitted two gamma rays at the opposite direction, by pair annihilation with electron. Each gamma ray is about 511 keV. The experiments of positron annihilation has been developed by three methods such as angular correlation between two gamma rays, energy analysis of emission gamma ray and positron lifetime. The angular correlation between two gamma rays is determined by gamma ray position detector.The energy analysis was measured by S-W analysis and Coincidence Doppler Broadening (CDB) method. Positron lifetime are determined by gamma-gamma lifetime measurement method, beta sup + -gamma lifetime measurement method and other method using waveform of photomultiplier, and determination of time and frequency of gamma-ray. Positron beam is applied to positron scattering, positron diffraction, low energy positron diffraction (LEPD), PELS, LEPSD, PAES, positron re-emission imaging microscope (PRIM) and positron channeling. The example of CDB method...

  3. Early detection of response to imatinib therapy for gastrointestinal stromal tumor by using 18F-FDG-positron emission tomography and computed tomography imaging

    Sabri Zincirkeser; Alper Sevinc; M Emin Kalender; Celalettin Camci

    2007-01-01

    A 41-year old female with metastatic gastrointestinal stromal tumor was referred to 18F-FDG-positron emission tomography and computed tomography (PET/CT) scan before and after one-month treatment with imatinib(Glivec(R), Gleevec(R), Novartis, Basel, Switzerland), a tyrosine kinase inhibitor (400 mg/d). Metabolic response was evaluated before and after one month of therapy. The decrease of the maximum standardised uptake value (SUV)was 79% (from 9.8 to 2.1). Positron emission tomography demonstrated complete metabolic response after one-month of imatinib treatment. Additionally, the previous lesion was compared with the coronal computerized tomographic image. There was no difference in the size of the tumor before and after therapy according to CT images. However, metabolic activity was inhibited.18F-FDG-PET is a valuable method for the detection of response to one-month imatinib treatment in patients with gastrointestinal stromal tumors.

  4. Increased fluoro-deoxy-D-glucose uptake on positron emission tomography-computed tomography postbronchoalveolar lavage: a potential cause of radiologic misinterpretation.

    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.

  5. Prospects for Detection of Synchrotron Emission from Secondary Electrons and Positrons in Starless Cores: Application to G0.216+0.016

    Jones, D I

    2014-01-01

    We investigate the diffusion of cosmic rays into molecular cloud complexes. Using the cosmic-ray diffusion formalism of Protheroe, et al. (2008), we examine how cosmic rays diffuse into clouds exhibiting different density structures, including a smoothed step-function, as well as Gaussian and inverse-$r$ density distributions, which are well known to trace the structure of star-forming regions. These density distributions were modelled as an approximation to the Galactic centre cloud G0.216+0.016, a recently-discovered massive dust clump that exhibits limited signs of massive star formation and thus may be the best region in the Galaxy to observe synchrotron emission from secondary electrons and positrons. Examination of the resulting synchrotron emission, produced by the interaction of cosmic ray protons interacting with ambient molecular matter producing secondary electrons and positrons reveals that, due to projection effects, limb-brightened morphology results in all cases. However, we find that the Gauss...

  6. Emission of Low-Energy Photons by Electrons at Electron-Positron and Electron-Ion Colliders with Dense Bunches

    Jentschura, U D; Serbo, V G; 10.1103/PhysRevSTAB.12.011003

    2009-01-01

    Usually, the emission of low-energy photons in electron-positron (or electron-ion) bunch collisions is calculated with the same approach as for synchrotron radiation (beamstrahlung). However, for soft photons (E_gamma < E_c where E_c is a critical photon energy), when the coherence length of the radiation becomes comparable to the bunch length, the beamstrahlung approximation becomes invalid. In this paper, we present results of our calculation for this region based on approximation of classical currents. We consider several colliders with dense bunches. The number of low-energy photons dN_gamma emitted by N_e electrons per bunch crossing in the energy interval dE_gamma is dN_gamma = alpha g N_e dE_gamma/E_gamma, where alpha is the fine-structure constant, and the function g, which depends on the bunch parameters, typically is of order unity for modern colliders. In particular, for the ILC, we find that E_c = 83 keV and g=5.5 at a vanishing beam axis displacement, and g=0.88, E_c=0.24 keV for KEKB. We also...

  7. A positron emission tomography study of the neural basis of informational and energetic masking effects in speech perception

    Scott, Sophie K.; Rosen, Stuart; Wickham, Lindsay; Wise, Richard J. S.

    2004-02-01

    Positron emission tomography (PET) was used to investigate the neural basis of the comprehension of speech in unmodulated noise (``energetic'' masking, dominated by effects at the auditory periphery), and when presented with another speaker (``informational'' masking, dominated by more central effects). Each type of signal was presented at four different signal-to-noise ratios (SNRs) (+3, 0, -3, -6 dB for the speech-in-speech, +6, +3, 0, -3 dB for the speech-in-noise), with listeners instructed to listen for meaning to the target speaker. Consistent with behavioral studies, there was SNR-dependent activation associated with the comprehension of speech in noise, with no SNR-dependent activity for the comprehension of speech-in-speech (at low or negative SNRs). There was, in addition, activation in bilateral superior temporal gyri which was associated with the informational masking condition. The extent to which this activation of classical ``speech'' areas of the temporal lobes might delineate the neural basis of the informational masking is considered, as is the relationship of these findings to the interfering effects of unattended speech and sound on more explicit working memory tasks. This study is a novel demonstration of candidate neural systems involved in the perception of speech in noisy environments, and of the processing of multiple speakers in the dorso-lateral temporal lobes.

  8. [(18)F]-Fluoro-Deoxy-Glucose Positron Emission Tomography Scan Should Be Obtained Early in Cases of Autoimmune Encephalitis.

    Newey, C R; Sarwal, A; Hantus, S

    2016-01-01

    Introduction. Autoimmune encephalitis (AE) is a clinically challenging diagnosis with nonspecific neurological symptoms. Prompt diagnosis is important and often relies on neuroimaging. We present a case series of AE highlighting the importance of an early [(18)F]-fluoro-deoxy-glucose positron emission tomography (FDG-PET) scan. Methods. Retrospective review of seven consecutive cases of autoimmune encephalitis. Results. All patients had both magnetic resonance imaging (MRI) and FDG-PET scans. Initial clinical presentations included altered mental status and/or new onset seizures. Six cases had serum voltage-gated potassium channel (VGKC) antibody and one had serum N-methyl-D-aspartate (NMDA) antibody. MRI of brain showed mesial temporal lobe hyperintensity in five cases of VGKC. The other two patients with VGKC or NMDA AE had restiform body hyperintensity on MRI brain or a normal MRI, respectively. Mesial temporal lobe hypermetabolism was noted in three cases on FDG-PET, despite initial unremarkable MRI. Malignancy workup was negative in all patients. Conclusion. A high index of suspicion for AE should be maintained in patients presenting with cognitive symptoms, seizures, and limbic changes on neuroimaging. In cases with normal initial brain MRI, FDG-PET can be positive. Additionally, extralimbic hyperintensity on MRI may also be observed.

  9. [18F]-Fluoro-Deoxy-Glucose Positron Emission Tomography Scan Should Be Obtained Early in Cases of Autoimmune Encephalitis

    C. R. Newey

    2016-01-01

    Full Text Available Introduction. Autoimmune encephalitis (AE is a clinically challenging diagnosis with nonspecific neurological symptoms. Prompt diagnosis is important and often relies on neuroimaging. We present a case series of AE highlighting the importance of an early [18F]-fluoro-deoxy-glucose positron emission tomography (FDG-PET scan. Methods. Retrospective review of seven consecutive cases of autoimmune encephalitis. Results. All patients had both magnetic resonance imaging (MRI and FDG-PET scans. Initial clinical presentations included altered mental status and/or new onset seizures. Six cases had serum voltage-gated potassium channel (VGKC antibody and one had serum N-methyl-D-aspartate (NMDA antibody. MRI of brain showed mesial temporal lobe hyperintensity in five cases of VGKC. The other two patients with VGKC or NMDA AE had restiform body hyperintensity on MRI brain or a normal MRI, respectively. Mesial temporal lobe hypermetabolism was noted in three cases on FDG-PET, despite initial unremarkable MRI. Malignancy workup was negative in all patients. Conclusion. A high index of suspicion for AE should be maintained in patients presenting with cognitive symptoms, seizures, and limbic changes on neuroimaging. In cases with normal initial brain MRI, FDG-PET can be positive. Additionally, extralimbic hyperintensity on MRI may also be observed.

  10. [18F]-Fluoro-Deoxy-Glucose Positron Emission Tomography Scan Should Be Obtained Early in Cases of Autoimmune Encephalitis

    Sarwal, A.; Hantus, S.

    2016-01-01

    Introduction. Autoimmune encephalitis (AE) is a clinically challenging diagnosis with nonspecific neurological symptoms. Prompt diagnosis is important and often relies on neuroimaging. We present a case series of AE highlighting the importance of an early [18F]-fluoro-deoxy-glucose positron emission tomography (FDG-PET) scan. Methods. Retrospective review of seven consecutive cases of autoimmune encephalitis. Results. All patients had both magnetic resonance imaging (MRI) and FDG-PET scans. Initial clinical presentations included altered mental status and/or new onset seizures. Six cases had serum voltage-gated potassium channel (VGKC) antibody and one had serum N-methyl-D-aspartate (NMDA) antibody. MRI of brain showed mesial temporal lobe hyperintensity in five cases of VGKC. The other two patients with VGKC or NMDA AE had restiform body hyperintensity on MRI brain or a normal MRI, respectively. Mesial temporal lobe hypermetabolism was noted in three cases on FDG-PET, despite initial unremarkable MRI. Malignancy workup was negative in all patients. Conclusion. A high index of suspicion for AE should be maintained in patients presenting with cognitive symptoms, seizures, and limbic changes on neuroimaging. In cases with normal initial brain MRI, FDG-PET can be positive. Additionally, extralimbic hyperintensity on MRI may also be observed. PMID:27559482

  11. Positron emission tomography changes management and prognostic stratification in patients with oesophageal cancer: results of a multicentre prospective study

    Chatterton, B.E. [Royal Adelaide Hospital, Department of Nuclear Medicine and PET, Adelaide, SA (Australia); Ho Shon, I. [Liverpool Hospital, Department of Nuclear Medicine and PET, Sydney (Australia); Baldey, A. [MIA at Monash Medical Centre, Melbourne (Australia); Lenzo, N.; Patrikeos, A. [Sir Charles Gairdner Hospital, WA PET/Cyclotron Service, Perth (Australia); Kelley, B.; Wong, D. [The Wesley Hospital, Southern X-Ray Clinics, Brisbane (Australia); Ramshaw, J.E. [Australian and New Zealand Association of Physicians in Nuclear Medicine, Melbourne (Australia); Scott, A.M. [Austin Hospital, Centre for PET, and Ludwig Institute for Cancer Research, Melbourne (Australia)

    2009-03-15

    The aims of this study were (1) to determine the incremental information provided by {sup 18}F-FDG positron emission tomography (PET) in staging patients with oesophageal cancer, and (2) to determine the impact of PET staging on post-PET clinical management of oesophageal cancer, and on prognosis. In a multicentre, single-arm open study, patients with proved oesophageal cancer without definite distant metastases and regarded as suitable for potentially curative treatment were examined by PET. Clinicians were requested to supply a management plan before and another plan after being supplied with the PET scan results. Patients were followed for at least 1 year for outcome analysis. A total of 129 patients (104 men, mean age 67 y) were recruited. PET detected additional sites of disease in 53 patients (41%). Significant changes in management (high or medium impact) were observed in 38% of patients, primarily as a result of identifying additional sites of disease and/or confirming previously equivocal regional and distant metastases. Progression-free survival was significantly shorter in patients found to have additional lesions on PET (p < 0.05), but was not related to SUV{sub max}. These findings demonstrate the significant impact of PET on the clinical management of patients with newly diagnosed oesophageal carcinoma, and on prognostic stratification of these patients. (orig.)

  12. Kikuchi-Fujimoto disease mimicking tuberculous lymphadenitis or lymphoma on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

    Abdul Rahim N

    2016-07-01

    Full Text Available Noraini Abdul Rahim,1 Abdul Jalil Nordin,2 Chiara Rusconi,3 Cristina Gabutti,3 Erika Ravelli,4 Claudio Rossetti5 1Diagnostic Imaging Department, Serdang Hospital, Selangor, 2Centre for Diagnostic Nuclear Imaging, University Putra Malaysia, Serdang, Malaysia; 3Department of Haematology, Ospedale Niguarda, Milan, 4Unit of Haematology, Valduce Hospital, Como, 5Department of Advance Technology (Nuclear Medicine, Ospedale Niguarda, Milan, Italy Abstract: Kikuchi-Fujimoto disease, also known as histiocytic lymphadenitis is a rare and benign disease characterized by regional cervical lymphadenopathy with fever of unknown origin, affecting mainly young women. We describe a case of a young Asian female who was initially misdiagnosed as having tuberculous lymphadenitis because of multiple lymphadenopathies with 18-fluorodeoxyglucose uptake on positron emission tomography/computed tomography. Final histologic diagnosis of Kikuchi-Fujimoto disease was made after excisional biopsy of the affected lymph node. The cervical lymphadenopathy has reduced in size and lung lesions disappeared after 2 months without specific treatment. Keywords: cervical lymphadenopathy, Kikuchi disease, PET/CT features

  13. Ectopic Cervical Thymoma:A Case Report with 18F-fluorodeoxyglucose Positron Emission Tomography Findings

    Shien,Kazuhiko

    2012-08-01

    Full Text Available Ectopic thymoma is considered to arise from ectopic thymus tissue deposited as a result of the abnormal mislocalization of thymus tissue during the embryonic stage. An 86-year-old man visited our hospital with chief complaints of hoarseness and a mass in his anterior neck. A preoperative needle biopsy of the mass did not yield a definitive diagnosis. A positron emission tomography (PET study revealed heterogeneous accumulation of 18F-fluorodeoxyglucose (FDG in the tumor. The tumor, affecting the left sternocleidomastoid muscle, the recurrent laryngeal nerve, the internal carotid vein, and the brachiocephalic vein, was resected using a combination of a collar incision in the neck and a median incision in the sternum. Immunohistochemically, the tumor was diagnosed as an ectopic thymoma of the neck. To date, only a few cases of ectopic thymoma presenting with FDG accumulation have been reported. Our experience indicates that ectopic thymoma should be kept in mind during the differential diagnosis of neck tumors with FDG accumulation appearing on PET images.

  14. Synthesis and evaluation of fluorinated derivatives of fentanyl as candidates for opiate receptor studies using positron emission tomography

    Dahren Hwang; Feliu, A.L.; Wolf, A.P.; MacGregor, R.R.; Fowler, J.S.; Arnett, C.D.

    1986-03-01

    Three fluorinated derivatives of fentanyl, fluorofentanyl (3), keto-fluorofentanyl (5), and fluorofentanol (6), were synthesized and their abilities to compete with /sup 3/diprenorphine for binding sites in guinea pig brain membranes were determined. The relative potencies were fentanyl > 3 approx.= 6 >> 5. On the basis of its apparent affinity for opiate receptors and its relative ease of synthesis, 6 was selected for further study. Fentanyl was slightly better than 6 in its ability to compete with (/sup 3/H)naltrexone for binding sites in rat brain membranes. Both fentayl and 6 exhibited a similar high ''sodium ratio'' (quotient of the IC/sub 50/'s against (/sup 3/H)naltrexone in the presence and absence of sodium chloride) generally characteristic of opiate agonists. The analgesic potencies of fentanyl and 6 were determined in rats by measuring suppression of locomotion and vocalization responses to footshock. 6 appeared slightly less potent than fentanyl, but produced a similar analgesia and catalepsy which was entirely blocked by pretreatment of rats with naloxone, an opiate antagonist. A rapid synthesis of (/sup 18/F)-6 was developed and the tissue distribution of (/sup 18/F)-6 in mice was determined 5, 60, and 120 minutes after intravenous injection. The use of this general route to /sup 18/F-labeled derivatives of fentanyl for studies of the opiate receptor using positron emission tomography is planned.

  15. Dynamic 18F-fluorodeoxyglucose positron emission tomography/CT in hibernoma: enhanced tracer uptake mimicking liposarcoma

    Christos; Sachpekidis; Safwan; Roumia; Matthias; Schwarzbach; Antonia; Dimitrakopoulou-Strauss

    2013-01-01

    We report on two cases of patients with fat-equivalent masses in computed tomography(CT),referred to our department for dynamic positron emission tomography/CT(dPET/CT)with18F-fluorodeoxyglucose(18FFDG)in order to investigate their dignity.Both qualitative and quantitative information,as derived from dPET/CTs,couldn’t exclude a high-grade liposarcoma:Visual evaluation,revealed a large hypermetabolic focus of intense18F-FDG uptake in each patient(average SUVs 8.3 and 11.3).Regression-based parametric imaging demonstrated an enhanced distribution volume,which correlates to perfusion,and a high phosphorylation rate that correlates to cell viability.Kinetic analysis,based on a two-tissue compartment model demonstrated an enhanced FDG transport k1and an enhanced phosphorylation rate k3.A non-compartmental approach based on fractal dimension revealed also enhanced values.However,final diagnosis was based on biopsy,which revealed hibernoma,a benign brown fat tumor.Brown adipose contains increased numbers of mitochondria and a high-rate of glucose metabolism.Therefore,they have increased FDG uptake.The evaluation of lipomatous lesions on CT,with high FDG uptake,should include the possibility of hibernoma as a differential diagnosis.

  16. Determination of Fatty Acid Metabolism with Dynamic [11C]Palmitate Positron Emission Tomography of Mouse Heart In Vivo

    Yinlin Li

    2015-09-01

    Full Text Available The goal of this study was to establish a quantitative method for measuring fatty acid (FA metabolism with partial volume (PV and spill-over (SP corrections using dynamic [11C]palmitate positron emission tomographic (PET images of mouse heart in vivo. Twenty-minute dynamic [11C]palmitate PET scans of four 18- to 20-week-old male C57BL/6 mice under isoflurane anesthesia were performed using a Focus F-120 PET scanner. A model-corrected blood input function, by which the input function with SP and PV corrections and the metabolic rate constants (k1–k5 are simultaneously estimated from the dynamic [11C]palmitate PET images of mouse hearts in a four-compartment tracer kinetic model, was used to determine rates of myocardial fatty acid oxidation (MFAO, myocardial FA esterification, myocardial FA use, and myocardial FA uptake. The MFAO thus measured in C57BL/6 mice was 375.03 ± 43.83 nmol/min/g. This compares well to the MFAO measured in perfused working C57BL/6 mouse hearts ex vivo of about 350 nmol/g/min and 400 nmol/min/g. FA metabolism was measured for the first time in mouse heart in vivo using dynamic [11C]palmitate PET in a four-compartment tracer kinetic model. MFAO obtained with this model was validated by results previously obtained with mouse hearts ex vivo.

  17. Optimized and Automated Radiosynthesis of [18F]DHMT for Translational Imaging of Reactive Oxygen Species with Positron Emission Tomography

    Wenjie Zhang

    2016-12-01

    Full Text Available Reactive oxygen species (ROS play important roles in cell signaling and homeostasis. However, an abnormally high level of ROS is toxic, and is implicated in a number of diseases. Positron emission tomography (PET imaging of ROS can assist in the detection of these diseases. For the purpose of clinical translation of [18F]6-(4-((1-(2-fluoroethyl-1H-1,2,3-triazol-4-ylmethoxyphenyl-5-methyl-5,6-dihydrophenanthridine-3,8-diamine ([18F]DHMT, a promising ROS PET radiotracer, we first manually optimized the large-scale radiosynthesis conditions and then implemented them in an automated synthesis module. Our manual synthesis procedure afforded [18F]DHMT in 120 min with overall radiochemical yield (RCY of 31.6% ± 9.3% (n = 2, decay-uncorrected and specific activity of 426 ± 272 GBq/µmol (n = 2. Fully automated radiosynthesis of [18F]DHMT was achieved within 77 min with overall isolated RCY of 6.9% ± 2.8% (n = 7, decay-uncorrected and specific activity of 155 ± 153 GBq/µmol (n = 7 at the end of synthesis. This study is the first demonstration of producing 2-[18F]fluoroethyl azide by an automated module, which can be used for a variety of PET tracers through click chemistry. It is also the first time that [18F]DHMT was successfully tested for PET imaging in a healthy beagle dog.

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

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

    2016-02-15

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

  19. Development of a New Positron Emission Tomography Tracer for Targeting Tumor Angiogenesis: Synthesis, Small Animal Imaging, and Radiation Dosimetry

    David S. Lalush

    2013-05-01

    Full Text Available Angiogenesis plays a key role in cancer progression and correlates with disease aggressiveness and poor clinical outcomes. Affinity ligands discovered by screening phage display random peptide libraries can be engineered to molecularly target tumor blood vessels for noninvasive imaging and early detection of tumor aggressiveness. In this study, we tested the ability of a phage-display-selected peptide sequence recognizing specifically bone marrow- derived pro-angiogenic tumor-homing cells, the QFP-peptide, radiolabeled with 64Cu radioisotope to selectively image tumor vasculature in vivo by positron emission tomography (PET. To prepare the targeted PET tracer we modified QFP-phage with the DOTA chelator and radiolabeled the purified QFP-phage-DOTA intermediate with 64Cu to obtain QFP-targeted radioconjugate with high radiopharmaceutical yield and specific activity. We evaluated the new PET tracer in vivo in a subcutaneous (s.c. Lewis lung carcinoma (LLC mouse model and conducted tissue distribution, small animal PET/CT imaging study, autoradiography, histology, fluorescence imaging, and dosimetry assessments. The results from this study show that, in the context of the s.c. LLC immunocompetent mouse model, the QFP-tracer can target tumor blood vessels selectively. However, further optimization of the biodistribution and dosimetry profile of the tracer is necessary to ensure efficient radiopharmaceutical applications enabled by the biological specificity of the QFP-peptide.

  20. Sub-100 ps coincidence time resolution for positron emission tomography with LSO:Ce codoped with Ca

    Nemallapudi, Mythra Varun; Lecoq, Paul; Auffray, Etiennette; Ferri, Alessandro; Gola, Alberto; Piemonte, Claudio

    2015-01-01

    The coincidence time resolution (CTR) becomes a key parameter of 511keV gamma detection in time of flight positron emission tomography (TOF-PET). This is because additional information obtained through timing leads to a better noise suppression and therefore a better signal to noise ratio in the reconstructed image. In this paper we present the results of CTR measurements on two different SiPM technologies from FBK coupled to LSO:Ce codoped 0.4%Ca crystals. We compare the measurements performed at two separate test setups, i.e. at CERN and at FBK, showing that the obtained results agree within a few percent. We achieve a best CTR value of 85  ±  4 ps FWHM for 2  ×  2  ×  3 mm3 LSO:Ce codoped 0.4%Ca crystals, thus breaking the 100 ps barrier with scintillators similar to LSO:Ce or LYSO:Ce. We also demonstrate that a CTR of 140  ±  5 ps can be achieved for longer 2  ×  2  ×  20 mm3 crystals, which can readily be implemented in the current generation PET syst...

  1. Positron emission tomography in cerebrovascular disease: The relationship between regional cerebral blood flow, blood volume and oxygen metabolism

    Herold, S.

    1985-03-01

    Positron emission tomography in cerebrovascular disease has demonstrated the importance of the relationship between regional cerebral blood flow and the cerebral metabolic activity. In acute stroke it has been found that within the first hours after the onset of symptoms cerebral blood flow in the affected area is more depressed than cerebral oxygen utilisation. This relative preservation of oxygen utilisation results from an increase in the oxygen extraction ratio far above its normal value. However, the oxygen extraction fraction subsequently falls in the following days indicating the transition from a situation of possibly reversible ischaemia to irreversible infarction. In patients with carotid occlusive disease an increase in the oxygen extraction ratio has been observed only in very few cases. It has been shown, however, that at an earlier stage the relationship between CBF and CBV (as CBF/CBV-ratio) provides a sensitive measure of diminished perfusion pressure which could be helpful for the selection of patients for EC-IC bypass surgery. In patients with sickle cell anaemia it has been found that oxygen delivery to the brain is maintained by an increase in cerebral blood flow, whereas the oxygen extraction ratio is not increased despite the presence of a low oxygen affinity haemoglobin. Preliminary observations in classical migraine suggest an ischaemic situation during the attack.

  2. Synthesis of sup 11 C-labeled imipramine and its biodistribution in mice; A potential tracer for positron emission tomography

    Nakamura, Hitoshi; Edo, Kiyoto; Hishinuma, Takanori; Mizugaki, Michinao (Tohoku University Hospital, Sendai (Japan). Department of Pharmaceutical Sciences); Takahashi, Toshihiro; Ido, Tatsuo

    1989-12-01

    A tricyclic antidepressant, {sup 11}C-labeled imipramine was synthesized by N-methylation of desipramine with {sup 11}CH{sub 3}I to assist in the imaging of the human imipramine receptor by positron emission tomography. The radiochemical yield after purification of {sup 11}C-imipramine by high performance liquid chromatography was 28-63% at a specific activity of 26-53 Ci/mmol. The time required for synthesis, including purification was 30 min from the end of {sup 11}CH{sub 3}I trapping. The organ distribution of {sup 11}C-imipramine was investigated in mice at various times after i.v. injection. The main accumulation of radioactivity was in the kidney, followed by the lung and the heart. In the brain, the radioactivity levels in the hypothalamus and striatum were the highest and remained constant, differentiating them from other portions of the brain. Furthermore, the result of a binding assay with {sup 3}H-labeled imipramine suggested that the regional distribution of {sup 11}C-imipramine in the same mouse brain correlated to that of the high affinity imipramine binding site. (author).

  3. Using Positron Emission Tomography with [18F]FDG to Predict Tumor Behavior in Experimental Colorectal Cancer

    Bryan M. Burt

    2001-01-01

    Full Text Available This study investigates the relationship between FDG uptake as determined by positron emission tomography (PET imaging and rates of tumor growth, cellular GLUT1 transporter density, and the activities of hexokinase and glucose-6-phosphatase in a solid tumor implant model. Five different human colorectal xenografts of different growth properties were implanted in athymic rats and evaluated by dynamic 18F-FDG-PET. The phosphorylating and dephosphorylating activities of the key glycolytic enzymes, hexokinase and glucose-6-phosphatase, were measured in these tumor types by spectrophotometric assays and the expression of GLUT1 glucose transporter protein was determined by immunohistochemistry. Correlations among FDG accumulation, hexokinase activity, and tumor doubling time are reported in these colon xenografts. The results indicate that the activity of tumor hexokinase may be a marker of tumor growth rate that can be determined by 18F-FDG-PET imaging. PET scanning may not only be a useful tool for staging patients for extent of disease, but may provide important prognostic information concerning the proliferative rates of malignancies.

  4. 2-deoxy-2-(18F)fluoro-D-glucose positron emission tomography/computed tomography imaging in paediatric oncology

    John; Freebody; Eva; A; Wegner; Monica; A; Rossleigh

    2014-01-01

    Positron emission tomography(PET) is a minimally in-vasive technique which has been well validated for the diagnosis, staging, monitoring of response to therapy, and disease surveillance of adult oncology patients. Tra-ditionally the value of PET and PET/computed tomogra-phy(CT) hybrid imaging has been less clearly defined for paediatric oncology. However recent evidence has emerged regarding the diagnostic utility of these mo-dalities, and they are becoming increasingly important tools in the evaluation and monitoring of children with known or suspected malignant disease. Important indi-cations for 2-deoxy-2-(18F)fluoro-D-glucose(FDG) PET in paediatric oncology include lymphoma, brain tumours, sarcoma, neuroblastoma, Langerhans cell histiocytosis, urogenital tumours and neurofibromatosis type Ⅰ. This article aims to review current evidence for the use of FDG PET and PET/CT in these indications. Attention will also be given to technical and logistical issues, the description of common imaging pitfalls, and dosimetric concerns as they relate to paediatric oncology.

  5. Application of positron emission tomography/computed tomography in radiation treatment planning for head and neck cancers

    Musaddiq; J; Awan; Farzan; Siddiqui; David; Schwartz; Jiankui; Yuan; Mitchell; Machtay; Min; Yao

    2015-01-01

    18-fluorodeoxygluocose positron emission tomography/computed tomography(18FDG-PET/CT) provides significant information in multiple settings in the management of head and neck cancers(HNC). This article seeks to define the additional benefit of PET/CT as related to radiation treatment planning for squamous cell carcinomas(SCCs) of the head and neck through a review of relevant literature. By helping further define both primary and nodal volumes, radiation treatment planning can be improved using PET/CT. Special attention is paid to the independent benefit of PET/CT in targeting mucosal primaries as well as in detecting nodal metastases. The utility of PET/CT is also explored for treatment planning in the setting of SCC of unknown primary as PET/CT may help define a mucosal target volume by guiding biopsies for examination under anesthesia thus changing the treatment paradigm and limiting the extent of therapy. Implications of the use of PET/CT for proper target delineation in patients with artifact from dental procedures are discussed and the impact of dental artifact on CT-based PET attenuation correction is assessed. Finally, comment is made upon the role of PET/CT in the high-risk post-operative setting, particularly in the context of radiation dose escalation. Real case examples are used in these settings to elucidate the practical benefits of PET/CT as related to radiation treatment planning in HNCs.

  6. (11)C- and (18)F-Labeled Radioligands for P-Glycoprotein Imaging by Positron Emission Tomography.

    Cantore, Mariangela; Benadiba, Marcel; Elsinga, Philip H; Kwizera, Chantal; Dierckx, Rudi A J O; Colabufo, Nicola Antonio; Luurtsema, Gert

    2016-01-01

    P-Glycoprotein (P-gp) is an efflux transporter widely expressed at the human blood-brain barrier. It is involved in xenobiotics efflux and in onset and progression of neurodegenerative disorders. For these reasons, there is great interest in the assessment of P-gp expression and function by noninvasive techniques such as positron emission tomography (PET). Three radiolabeled aryloxazole derivatives: 2-[2-(2-methyl-((11)C)-5-methoxyphenyl)oxazol-4-ylmethyl]-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline ([(11)C]-5); 2-[2-(2-fluoromethyl-((18)F)-5-methoxyphenyl)oxazol-4-ylmethyl]-6,7-dimethoxy-1,2,3,4-tetra-hydroisoquinoline ([(18)F]-6); and 2-[2-(2-fluoroethyl-((18)F)-5-methoxyphenyl)oxazol-4-ylmethyl]-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline ([(18)F]-7), were tested in several in vitro biological assays to assess the effect of the aryl substituent in terms of potency and mechanism of action toward P-gp. Methyl derivative [(11)C]-5 is a potent P-gp substrate, whereas the corresponding fluoroethyl derivative [(18)F]-7 is a P-gp inhibitor. Fluoromethyl compound [(18)F]-6 is classified as a non-transported P-gp substrate, because its efflux increases after cyclosporine A modulation. These studies revealed a promising substrate and inhibitor, [(11)C]-5 and [(18)F]-7, respectively, for in vivo imaging of P-gp by using PET.

  7. Semi-supervised manifold learning with affinity regularization for Alzheimer's disease identification using positron emission tomography imaging.

    Lu, Shen; Xia, Yong; Cai, Tom Weidong; Feng, David Dagan

    2015-01-01

    Dementia, Alzheimer's disease (AD) in particular is a global problem and big threat to the aging population. An image based computer-aided dementia diagnosis method is needed to providing doctors help during medical image examination. Many machine learning based dementia classification methods using medical imaging have been proposed and most of them achieve accurate results. However, most of these methods make use of supervised learning requiring fully labeled image dataset, which usually is not practical in real clinical environment. Using large amount of unlabeled images can improve the dementia classification performance. In this study we propose a new semi-supervised dementia classification method based on random manifold learning with affinity regularization. Three groups of spatial features are extracted from positron emission tomography (PET) images to construct an unsupervised random forest which is then used to regularize the manifold learning objective function. The proposed method, stat-of-the-art Laplacian support vector machine (LapSVM) and supervised SVM are applied to classify AD and normal controls (NC). The experiment results show that learning with unlabeled images indeed improves the classification performance. And our method outperforms LapSVM on the same dataset.

  8. Effect of the duration of fasting on myocardial fluorine-18-fluorodeoxyglucose positron emission tomography images in normal males

    Yamanouchi, Masato; Yoshida, Katsuya; Niwayama, Hiroyuki [Chiba Univ. (Japan). School of Medicine] [and others

    1996-06-01

    To evaluate the effect of the duration of fasting on myocardial fluorine-18-fluorodeoxyglucose (FDG) uptake and distribution, 16 FDG-positron emission tomography (PET) studies were performed in 7 normal volunteers under three different conditions: glucose loading, 6 h fasting and overnight fasting. In the glucose-loaded condition, all subjects had good image quality, and myocardial metabolic rates of glucose (MRGlc) were significantly higher than those in the other two conditions. In the 6 h and overnight fasting conditions, image qualities varied according to MRGlc. Although there were visually distinct regional differences with MRGlc ranging from 0.05 to 0.15 {mu}mol/min per g, these differences were not impressive by a quantitative analysis. The ranges of MRGlc in these two fasted conditions overlapped each other. There was a significant negative linear correlation between MRGlc and serum free fatty acid levels Thus, MRGlc and image quality in fasted normal subjects varied with the extent of the fed-to-starved transition under clinical fasting conditions (6 h to overnight), and this transition does not depend solely on the duration of fasting. These findings may explain the heterogeneity in FDG studies under fasting conditions. (author)

  9. Analytical Study of the Effect of the System Geometry on Photon Sensitivity and Depth of Interaction of Positron Emission Mammography

    Pablo Aguiar

    2012-01-01

    Full Text Available Positron emission mammography (PEM cameras are novel-dedicated PET systems optimized to image the breast. For these cameras it is essential to achieve an optimum trade-off between sensitivity and spatial resolution and therefore the main challenge for the novel cameras is to improve the sensitivity without degrading the spatial resolution. We carry out an analytical study of the effect of the different detector geometries on the photon sensitivity and the angle of incidence of the detected photons which is related to the DOI effect and therefore to the intrinsic spatial resolution. To this end, dual head detectors were compared to box and different polygon-detector configurations. Our results showed that higher sensitivity and uniformity were found for box and polygon-detector configurations compared to dual-head cameras. Thus, the optimal configuration in terms of sensitivity is a PEM scanner based on a polygon of twelve (dodecagon or more detectors. We have shown that this configuration is clearly superior to dual-head detectors and slightly higher than box, octagon, and hexagon detectors. Nevertheless, DOI effects are increased for this configuration compared to dual head and box scanners and therefore an accurate compensation for this effect is required.

  10. Fluorine-18 labeled rare-earth nanoparticles for positron emission tomography (PET) imaging of sentinel lymph node.

    Sun, Yun; Yu, Mengxiao; Liang, Sheng; Zhang, Yingjian; Li, Chenguang; Mou, Tiantian; Yang, Wenjiang; Zhang, Xianzhong; Li, Biao; Huang, Chunhui; Li, Fuyou

    2011-04-01

    Rare-earth-based nanoparticles have attracted increasing attention for their unique optical and magnetic properties. However, their application in bioimaging has been limited to photoluminescence bioimaging and magnetic resonance imaging. To facilitate their use in other bioimaging techniques, we developed a simple, rapid, efficient and general synthesis strategy for (18)F-labeled rare-earth nanoparticles through a facile inorganic reaction between rare-earth cations and fluoride ions. The (18)F-labeling process based on rare-earth elements was achieved efficiently in water at room temperature with an (18)F-labeling yield of >90% and completed within 5 min, with only simple purification by aqueous washing and centrifugation, and without the use of organic agents. The effectiveness of (18)F-labeled rare-earth nanoparticles was further evaluated by positron emission tomography (PET) imaging of their in vivo distribution and application in lymph monitoring. In addition, this strategy is proposed for the creation of a dual-model bioimaging technique, combining upconversion luminescence bioimaging and PET imaging.

  11. [¹³N]Ammonia positron emission tomographic/computed tomographic imaging targeting glutamine synthetase expression in prostate cancer.

    Shi, Xinchong; Zhang, Xiangsong; Yi, Chang; Liu, Yubo; He, Qiao

    2014-01-01

    The purpose of this study was to investigate the expression of glutamine synthetase (GS) in prostate cancer (PCa) and the utility of [¹³N]ammonia positron emission tomography/computed tomography (PET/CT) in the imaging of PCa. The uptake ratio of [¹³N]ammonia and the expression of GS in PC3 and DU145 cells was measured. Thirty-four patients with suspected PCa underwent [¹³N]ammonia PET/CT imaging, and immunohistochemistry staining of GS was performed. The uptake of [¹³N]ammonia in PC3 and DU145 cells elevated along with the decrease in glutamine in medium. The expression of GS messenger ribonucleic acid and protein also increased when glutamine was deprived. In biopsy samples, the GS expression scores were significantly higher in PCa tissue than in benign tissues (p glutamine. GS is the main reason for the uptake of [¹³N]ammonia, and [¹³N]ammonia is a useful tracer for PCa imaging.

  12. Novel method for hit-position reconstruction using voltage signals in plastic scintillators and its application to Positron Emission Tomography

    Raczynski, L; Kowalski, P; Wislicki, W; Bednarski, T; Bialas, P; Czerwinski, E; Kaplon, L; Kochanowski, A; Korcyl, G; Kowal, J; Kozik, T; Krzemien, W; Kubicz, E; Molenda, M; Moskal, I; Niedzwiecki, Sz; Palka, M; Pawlik-Niedzwiecka, M; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Slomski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Zielinski, M; Zon, N

    2014-01-01

    Currently inorganic scintillator detectors are used in all commercial Time of Flight Positron Emission Tomograph (TOF-PET) devices. The J-PET collaboration investigates a possibility of construction of a PET scanner from plastic scintillators which would allow for single bed imaging of the whole human body. This paper describes a novel method of hit-position reconstruction based on sampled signals and an example of an application of the method for a single module with a 30 cm long plastic strip, read out on both ends by Hamamatsu R4998 photomultipliers. The sampling scheme to generate a vector with samples of a PET event waveform with respect to four user-defined amplitudes is introduced. The experimental setup provides irradiation of a chosen position in the plastic scintillator strip with an annihilation gamma quanta of energy 511~keV. The statistical test for a multivariate normal (MVN) distribution of measured vectors at a given position is developed, and it is shown that signals sampled at four threshold...

  13. Impaired myocardial blood flow reserve in subjects with metabolic syndrome analyzed using positron emission tomography and N-13 labeled ammonia

    Teragawa, Hiroki; Kihara, Yasuki [Hiroshima University Graduate School of Biomedical Sciences, Department of Cardiovascular Medicine, Hiroshima (Japan); Morita, Koichi; Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); Shishido, Hiroki; Otsuka, Nobuaki; Hirokawa, Yutaka [Hiroshima Heiwa Clinic, Hiroshima (Japan); Chayama, Kazuaki [Hiroshima University Graduate School of Biomedical Sciences, Department of Molecular Science and Medicine, Hiroshima (Japan)

    2010-02-15

    Coronary vasomotor response might be impaired in metabolic syndrome (MS); however, the precise abnormality has not been elucidated. The aim of this study was to assess coronary-vasomotor response in MS subjects using N-13 labeled ammonia and positron emission tomography. Myocardial blood flow (MBF) was measured at rest and during adenosine infusion in MS subjects (n = 13, MS group) with no definite evidence of heart disease and in subjects without MS (n = 14, non-MS group). Coronary vascular resistance (CVR) was calculated by dividing the mean aortic blood pressure by MBF. Myocardial blood flow reserve (MFR) was calculated as the ratio of the MBF during adenosine infusion to that during rest. Blood chemical parameters were measured to evaluate their relationship with MFR. During adenosine infusion, MBF was lower (p = 0.0085) and CVR higher (p = 0.0128) in the MS group than in the non-MS group and MFR was significantly lower in the MS group than in the non-MS group (2.13 {+-} 0.99 vs. 3.38 {+-} 0.95, p = 0.0027). Multivariate analysis demonstrated that the homeostasis model assessment-insulin resistance (p < 0.05) and the presence of hypertension (p < 0.05) were independent determinants of MFR. The results indicate that MFR was impaired in MS subjects, suggesting that an abnormal coronary microvascular response occurred in these subjects. This abnormality may have been partially due to insulin resistance and hypertension. (orig.)

  14. The effect of diazepam sedation on cerebral glucose metabolism in Alzheimer's disease as measured using positron emission tomography.

    Foster, N L; VanDerSpek, A F; Aldrich, M S; Berent, S; Hichwa, R H; Sackellares, J C; Gilman, S; Agranoff, B W

    1987-08-01

    The effect of sedation induced by intravenous diazepam on cerebral glucose metabolic activity was examined with [18F]2-fluoro-2-deoxy-D-glucose (FDG) and positron emission tomography (PET) in five patients with probable Alzheimer's disease. Each subject was studied on 2 separate days: on one occasion at rest with eyes patched and ears open, and on the second when sedated with intravenous diazepam titrated to maintain stage II sleep by clinical and EEG criteria. Similar patterns of glucose uptake were observed in both the presence and the absence of sedation, but overall glucose utilization was depressed an average of 20% and was closely correlated with the amount of diazepam administered prior to the injection of FDG. The predominant temporoparietal hypometabolism and relative sparing of frontal metabolism observed in this disease are therefore not explained by differences in anxiety or activity level in this patient group. Utilization of diazepam sedation for PET study appears to be safe and may permit the study of patients otherwise unable to cooperate with FDG-PET procedures.

  15. Effects of co-dergocrine mesylate (Hydergine) in multi-infarct dementia as evaluated by positron emission tomography

    Nagasawa, Haruo; Kogure, Kyuya; Kawashima, Koichiro (Tohoku Univ., Sendai (Japan). School of Medicine); Ido, Tatsuo; Itoh, Masatoshi; Hatazawa, Jun

    1990-11-01

    Three female patients aged from 74 to 79 with multi-infarct dementia were studied using positron emission tomography (PET) to assess the effect of co-dergocrine mesylate (Hydergine) on cerebral glucose metabolism. The cerebral glucose utilization (CMRGlc) of each patient was evaluated by PET scan using 2-deoxy-({sup 18}F)-2-fluoro-D-glucose (FDG). Following the first PET study, 0.04 mg/kg of co-dergocrine mesylate was injected intravenously with 250 ml saline solution, and then the second PET study was performed. The CMRGlc was determined from the images of the PET scan and the radioactivity of {sup 18}F in the plasma. After the administration of co-dergocrine mesylate, the value of CMRGlc increased significantly in the cerebral cortex (p<0.01 and p<0.05) and basal ganglia (p<0.05) compared with values before the administration, but no significant increase was found in the centrum semiovale. These results suggest that co-dergocrine mesylate stimulates glucose metabolism of neurons in the human brain. (author).

  16. Clinico-radiological correlation of Wilson's disease by magnetic resonance imaging, computed tomography and positron emission tomography

    Ikeda, Ken; Sakata, Chigusa; Nemoto, Hiroshi; Yokoi, Fuji; Sunohara, Nobuhiko (National Center of Neurology and Psychiatry, Kodaira, Tokyo (Japan)); Iio, Masaaki

    1991-02-01

    Five patients with Wilson's disease received repeated magnetic resonance imaging (MRI) and computed tomography (CT) examinations at intervals from 6 to 29 months. Four patients, except for asymptomatic one, also underwent positron emission tomography (PET). The significance and limitations of these imaging modalities were examined in the light of their correlation with clinical manifestations and their therapeutic evaluation. The following focal regions, detected on MRI, had a strong positive correlation with clinical manifestations: the lenticular nuclei for dystonia, the brain stem for abnormality of smooth persuit eye movements, and the caudate and lenticular nuclei for severe dysarthria/dysphagia. Follow-up MRI for 3 patients showed an improvement of findings in the lenticular nuclei, lateral part of the putamen, and brain stem, that was in accordance with improved clinical or neurologic manifestations, such as dystonia and cerebellar symptoms. Severe abnormality in the caudate nucleus was associated with poor prognosis. Repeated CT failed to show serial changes in any of the patients. Regional blood flow and oxygen metabolic rate, obtained by PET examinations, were slightly decreased in the thalamus that had normal findings on both MRI and CT, as well as in the cerebral cortex and basal ganglia. PET was, however, inferior to MRI in detecting fine foci within the basal ganglia. In conclusion, there was a good correlation between MRI findings, particularly foci of the caudate and lenticular nuclei, and clinical manifestations. Repeated MRI examinations were the most useful approach to the evaluation of therapeutic effects and prognosis. (N.K.).

  17. Precision-controlled elution of a 82Sr/82Rb generator for cardiac perfusion imaging with positron emission tomography

    Klein, R.; Adler, A.; Beanlands, R. S.; de Kemp, R. A.

    2007-02-01

    A rubidium-82 (82Rb) elution system is described for use with positron emission tomography. Due to the short half-life of 82Rb (76 s), the system physics must be modelled precisely to account for transport delay and the associated activity decay and dispersion. Saline flow is switched between a 82Sr/82Rb generator and a bypass line to achieve a constant-activity elution of 82Rb. Pulse width modulation (PWM) of a solenoid valve is compared to simple threshold control as a means to simulate a proportional valve. A predictive-corrective control (PCC) algorithm is developed which produces a constant-activity elution within the constraints of long feedback delay and short elution time. The system model parameters are adjusted through a self-tuning algorithm to minimize error versus the requested time-activity profile. The system is self-calibrating with 2.5% repeatability, independent of generator activity and elution flow rate. Accurate 30 s constant-activity elutions of 10-70% of the total generator activity are achieved using both control methods. The combined PWM-PCC method provides significant improvement in precision and accuracy of the requested elution profiles. The 82Rb elution system produces accurate and reproducible constant-activity elution profiles of 82Rb activity, independent of parent 82Sr activity in the generator. More reproducible elution profiles may improve the quality of clinical and research PET perfusion studies using 82Rb.

  18. Cardiac phantom measurement validating the methodology for a cardiac multi-centre trial with positron emission tomography.

    Nuyts, Johan; Mortelmans, Luc; Van de Werf, Frans; Djian, Jacques; Sambuceti, Gianmario; Schwaiger, Marcus; Touboul, Paul; Maes, Alex

    2002-12-01

    In an ongoing international multi-centre trial, positron emission tomography (PET) is being used to evaluate the effect of a new P-selectin antagonist on the infarct size in patients with acute myocardial infarction, treated with thrombolysis. Although it is possible to correct for site-dependent factors, it is desirable to reduce these factors to a minimum. Therefore, acquisition and reconstruction protocols have been defined that can be closely followed by all participating centres. The resulting reconstructed images are transferred to the core centre for central processing with semi-automatic software. This paper reports on the multi-centre phantom experiment that was carried out to assess the inter-centre reproducibility of defect size determination with this protocol. Also, the spatial resolution of the short axis slices was examined. In addition, the analysis procedure was applied to normal PET studies to evaluate the specificity of perfusion defect detection. The transmural cold defect in the phantom occupied 14.8% of the left ventricular area. The automated analysis was applied to the phantom measurements from the 14 participating PET cameras. It yielded an accurate estimate of 15.1% with a standard deviation of 0.6%, indicating excellent reproducibility. The spatial resolution in the short axis slices was similar for all PET systems: 9.6+/-0.8 mm. The same procedure produced a defect size of zero in the studies of normal volunteers. This study indicates that cardiac studies from multiple PET systems can be pooled for statistical analysis.

  19. Cardiac phantom measurement validating the methodology for a cardiac multi-centre trial with positron emission tomography

    Nuyts, Johan; Mortelmans, Luc; Maes, Alex [Nuclear Medicine, UZ Gasthuisberg, K.U. Leuven, Herestraat 49, 3000 Leuven (Belgium); Van de Werf, Frans [Cardiology, UZ Gasthuisberg, K.U. Leuven, Leuven (Belgium); Djian, Jacques [Wyeth Research, Paris la Defense Cedex (France); Sambuceti, Gianmario [Instituto di Fisiologia Clinica CNR, Pisa (Italy); Schwaiger, Marcus [Nuklearmedizinische Klinik und Poliklinik, TU Muenchen, Muenchen (Germany); Touboul, Paul [Hopital Cardio-Vasculaire et Pneumologique, Lyon (France)

    2002-12-01

    In an ongoing international multi-centre trial, positron emission tomography (PET) is being used to evaluate the effect of a new P-selectin antagonist on the infarct size in patients with acute myocardial infarction, treated with thrombolysis. Although it is possible to correct for site-dependent factors, it is desirable to reduce these factors to a minimum. Therefore, acquisition and reconstruction protocols have been defined that can be closely followed by all participating centres. The resulting reconstructed images are transferred to the core centre for central processing with semi-automatic software. This paper reports on the multi-centre phantom experiment that was carried out to assess the inter-centre reproducibility of defect size determination with this protocol. Also, the spatial resolution of the short axis slices was examined. In addition, the analysis procedure was applied to normal PET studies to evaluate the specificity of perfusion defect detection. The transmural cold defect in the phantom occupied 14.8% of the left ventricular area. The automated analysis was applied to the phantom measurements from the 14 participating PET cameras. It yielded an accurate estimate of 15.1% with a standard deviation of 0.6%, indicating excellent reproducibility. The spatial resolution in the short axis slices was similar for all PET systems: 9.6{+-}0.8 mm. The same procedure produced a defect size of zero in the studies of normal volunteers. This study indicates that cardiac studies from multiple PET systems can be pooled for statistical analysis. (orig.)

  20. Detection of amyloid in Alzheimer's disease with positron emission tomography using [{sup 11}C]AZD2184

    Nyberg, Svante; Cselenyi, Zsolt; Julin, Per; Olsson, Hans; Svensson, Samuel [AstraZeneca R and D, Neuroscience Therapy Area, Soedertaelje (Sweden); Eriksdotter Joenhagen, Maria; Freund-Levi, Yvonne [Karolinska University Hospital Huddinge, NVS Department, Karolinska Institute, Huddinge (Sweden); Halldin, Christer; Andersson, Jan; Varnaes, Katarina [Karolinska Institutet, Karolinska University Hospital, PET Centre, Department of Clinical Neuroscience, Stockholm (Sweden); Farde, Lars [AstraZeneca R and D, Neuroscience Therapy Area, Soedertaelje (Sweden); Karolinska Institutet, Karolinska University Hospital, PET Centre, Department of Clinical Neuroscience, Stockholm (Sweden)

    2009-11-15

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

  1. [18F]-FDG positron emission tomography--an established clinical tool opening a new window into exercise physiology.

    Rudroff, Thorsten; Kindred, John H; Kalliokoski, Kari K

    2015-05-15

    Positron emission tomography (PET) with [(18)F]-fluorodeoxyglucose (FDG) is an established clinical tool primarily used to diagnose and evaluate disease status in patients with cancer. PET imaging using FDG can be a highly valuable tool to investigate normal human physiology by providing a noninvasive, quantitative measure of glucose uptake into various cell types. Over the past years it has also been increasingly used in exercise physiology studies to identify changes in glucose uptake, metabolism, and muscle activity during different exercise modalities. Metabolically active cells transport FDG, an (18)fluorine-labeled glucose analog tracer, from the blood into the cells where it is then phosphorylated but not further metabolized. This metabolic trapping process forms the basis of this method's use during exercise. The tracer is given to a participant during an exercise task, and the actual PET imaging is performed immediately after the exercise. Provided the uptake period is of sufficient duration, and the imaging is performed shortly after the exercise; the captured image strongly reflects the metabolic activity of the cells used during the task. When combined with repeated blood sampling to determine tracer blood concentration over time, also known as the input function, glucose uptake rate of the tissues can be quantitatively calculated. This synthesis provides an accounting of studies using FDG-PET to measure acute exercise-induced skeletal muscle activity, describes the advantages and limitations of this imaging technique, and discusses its applications to the field of exercise physiology.

  2. Positron emission tomography studies in eating disorders: multireceptor brain imaging, correlates with behavior and implications for pharmacotherapy

    Frank, Guido K. [Department of Child and Adolescent Psychiatry, Center for Eating Disorders Research, School of Medicine, University of California San Diego, San Diego, CA 92123 (United States); Kaye, Walter H. [Department of Psychiatry, Western Psychiatric Institute and Clinic, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213 (United States)

    2005-10-01

    Modern imaging techniques that visualize disease-specific organ neurotransmitter or protein receptor sites are increasingly able to define pathological processes on a molecular level. One of those imaging modalities, positron emission tomography (PET), for the assessment of brain neuroreceptor binding has revolutionized the in vivo assessment of biologic markers that may be related to human behavior. Such studies may help identify chemical targets that may be directly related to psychiatric pathology and, thus, opportunities for pharmacological intervention. In this review, we describe results from PET studies in eating disorders (EDs). Eating disorders are frequently debilitating illnesses that are quite homogeneous in their presentation. Those studies that identified particular serotonin and dopamine receptor alterations can distinguish recovered ED subjects from controls as well as ED subgroups. Furthermore, correlations of receptor binding with behavioral constructs, such as harm avoidance or novelty seeking, could be found. These recognized receptors may now help us to move away from rather nonspecific treatment approaches in psychiatric research and clinic to the possibility of more syndrome- and symptom-specific treatment approaches.

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

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

    1984-01-01

    It is well established that Creutzfeldt-Jakob Disease (CJD) is caused by a slow infectious agent similar to the scrapie prion. However, the pathogenesis of this infection is poorly understood. Positron emission tomography (PET) was performed on a 54 year old male subject with autopsy confirmed CJD using (F-18)2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. An x-ray computed tomographic study of the brain performed 4 days prior to PET was normal. In the PET study the frontal to temporal cortex difference of activity densities was 30% on the left and 12% on the right, reflecting temporal hypometabolism. The left-right temporal cortex difference of activity density was 25%, documenting marked hemispheric asymmetry. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer's Disease (AD) and are distinctly different from PET-FDG finding in patients with other dementing illnesses or in healthy aged subjects. Recent work has demonstrated extensive biological similarities between CJD, scrapie and AD. The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the hypothesis that AD is caused by a slow infectious (prion-like) pathogen.

  4. 18-F fluorodeoxyglucose uptake in positron emission tomography as a pathological grade predictor for renal clear cell carcinomas

    Noda, Yoshifumi; Goshima, Satoshi; Kondo, Hiroshi; Watanabe, Haruo; Kawada, Hiroshi; Kawai, Nobuyuki; Tanahashi, Yukichi [Gifu University Hospital, Department of Radiology, Gifu (Japan); Kanematsu, Masayuki [Gifu University Hospital, Department of Radiology, Gifu (Japan); Gifu University Hospital, Department of Radiology Services, Gifu (Japan); Suzui, Natsuko [Gifu University Hospital, Department of Pathology, Gifu (Japan); Hirose, Yoshinobu [Osaka Medical College, Department of Pathology, Osaka (Japan); Matsunaga, Kengo [Kizawa Memorial Hospital, Department of Pathology, Minokamo (Japan); Nishibori, Hironori [Kizawa Memorial Hospital, Department of Radiology, Minokamo (Japan); Bae, Kyongtae T. [University of Pittsburgh Medical Center, Department of Radiology, Pittsburgh, PA (United States)

    2015-10-15

    To evaluate the usefulness of Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18-F FDG-PET/CT) in the prediction of Fuhrman pathological grades of renal clear cell carcinoma (cRCC). This retrospective study was approved by our institutional review board, and written informed consent was waived. Thirty-one patients with pathologically proven cRCC underwent 18-F FDG-PET/CT for tumour staging. Maximum standardized uptake value of cRCC (tumour SUV{sub max}) and mean SUV of the liver and spleen (liver and spleen SUV{sub mean}) were measured by two independent observers. Tumour SUV{sub max}, tumour-to-liver SUV ratio, and tumour-to-spleen SUV ratio were correlated with the pathological grades. Logistic analysis demonstrated that only the tumour-to-liver SUV ratio was a significant parameter for differentiating high-grade (Fuhrman grades 3 and 4) tumours from low-grade (Fuhrman grades 1 and 2) tumours (P = 0.007 and 0.010 for observers 1 and 2, respectively). Sensitivity, specificity, and positive and negative predictive values for detecting tumours of Fuhrman grades 3 and 4 were 64, 100, 100, and 77 %, respectively, for observer 1, and 79, 88, 85, and 83 %, respectively, for observer 2. The tumour-to-liver SUV ratio with 18-F FDG-PET/CT appeared to be a valuable imaging biomarker in the prediction of high-grade cRCC. (orig.)

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

    HMT Thomas

    2014-01-01

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

  6. Usefulness of Whole-Body Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography in Patients with Neurofibromatosis Type 1: A Systematic Review

    Giorgio Treglia

    2012-01-01

    Full Text Available Aim. To systematically review the role of positron emission tomography (PET with fluorine-18-fluorodeoxyglucose (FDG in patients with neurofibromatosis type 1 (NF1. Methods. A comprehensive literature search of published studies regarding FDG-PET and PET/CT in patients with NF1 was performed. No beginning date limit and language restriction were used; the search was updated until December 2011. Only those studies or subsets in studies including whole-body FDG-PET or PET/CT scans performed in patients with NF1 were included. Results. We identified 12 studies including 352 NF1 patients. Qualitative evaluation was performed in about half of the studies and semiquantitative analysis, mainly based on different values of SUV cutoff, in the others. Most of the studies evaluated the role of FDG-PET for differentiating benign from malignant peripheral nerve sheath tumors (MPNSTs. Malignant lesions were detected with a sensitivity ranging between 100% and 89%, but with lower specificity, ranging between 100% and 72%. Moreover, FDG-PET seems to be an important imaging modality for predicting the progression to MPNST and the outcome in patients with MPNST. Two studies evaluated the role of FDG-PET in pediatric patients with NF1. Conclusions. FDG-PET and PET/CT are useful methods to identify malignant change in neurogenic tumors in NF1 and to discriminate malignant from benign neurogenic lesions.

  7. Gaussian Mixture Models and Model Selection for [18F] Fluorodeoxyglucose Positron Emission Tomography Classification in Alzheimer's Disease.

    Rui Li

    Full Text Available We present a method to discover discriminative brain metabolism patterns in [18F] fluorodeoxyglucose positron emission tomography (PET scans, facilitating the clinical diagnosis of Alzheimer's disease. In the work, the term "pattern" stands for a certain brain region that characterizes a target group of patients and can be used for a classification as well as interpretation purposes. Thus, it can be understood as a so-called "region of interest (ROI". In the literature, an ROI is often found by a given brain atlas that defines a number of brain regions, which corresponds to an anatomical approach. The present work introduces a semi-data-driven approach that is based on learning the characteristics of the given data, given some prior anatomical knowledge. A Gaussian Mixture Model (GMM and model selection are combined to return a clustering of voxels that may serve for the definition of ROIs. Experiments on both an in-house dataset and data of the Alzheimer's Disease Neuroimaging Initiative (ADNI suggest that the proposed approach arrives at a better diagnosis than a merely anatomical approach or conventional statistical hypothesis testing.

  8. Longitudinal Assessment of Tau Pathology in Patients with Alzheimer's Disease Using [18F]THK-5117 Positron Emission Tomography.

    Aiko Ishiki

    Full Text Available The formation of neurofibrillary tangles is believed to contribute to the neurodegeneration observed in Alzheimer's disease (AD. Postmortem studies have shown strong associations between the neurofibrillary pathology and both neuronal loss and the severity of cognitive impairment. However, the temporal changes in the neurofibrillary pathology and its association with the progression of the disease are not well understood. Tau positron emission tomography (PET imaging is expected to be useful for the longitudinal assessment of neurofibrillary pathology in the living brain. Here, we performed a longitudinal PET study using the tau-selective PET tracer [18F]THK-5117 in patients with AD and in healthy control subjects. Annual changes in [18F]THK-5117 binding were significantly elevated in the middle and inferior temporal gyri and in the fusiform gyrus of patients with AD. Compared to patients with mild AD, patients with moderate AD showed greater changes in the tau load that were more widely distributed across the cortical regions. Furthermore, a significant correlation was observed between the annual changes in cognitive decline and regional [18F]THK-5117 binding. These results suggest that the cognitive decline observed in patients with AD is attributable to the progression of neurofibrillary pathology. Longitudinal assessment of tau pathology will contribute to the assessment of disease progression and treatment efficacy.

  9. Longitudinal Assessment of Tau Pathology in Patients with Alzheimer's Disease Using [18F]THK-5117 Positron Emission Tomography.

    Ishiki, Aiko; Okamura, Nobuyuki; Furukawa, Katsutoshi; Furumoto, Shozo; Harada, Ryuichi; Tomita, Naoki; Hiraoka, Kotaro; Watanuki, Shoichi; Ishikawa, Yoichi; Tago, Tetsuro; Funaki, Yoshihito; Iwata, Ren; Tashiro, Manabu; Yanai, Kazuhiko; Kudo, Yukitsuka; Arai, Hiroyuki

    2015-01-01

    The formation of neurofibrillary tangles is believed to contribute to the neurodegeneration observed in Alzheimer's disease (AD). Postmortem studies have shown strong associations between the neurofibrillary pathology and both neuronal loss and the severity of cognitive impairment. However, the temporal changes in the neurofibrillary pathology and its association with the progression of the disease are not well understood. Tau positron emission tomography (PET) imaging is expected to be useful for the longitudinal assessment of neurofibrillary pathology in the living brain. Here, we performed a longitudinal PET study using the tau-selective PET tracer [18F]THK-5117 in patients with AD and in healthy control subjects. Annual changes in [18F]THK-5117 binding were significantly elevated in the middle and inferior temporal gyri and in the fusiform gyrus of patients with AD. Compared to patients with mild AD, patients with moderate AD showed greater changes in the tau load that were more widely distributed across the cortical regions. Furthermore, a significant correlation was observed between the annual changes in cognitive decline and regional [18F]THK-5117 binding. These results suggest that the cognitive decline observed in patients with AD is attributable to the progression of neurofibrillary pathology. Longitudinal assessment of tau pathology will contribute to the assessment of disease progression and treatment efficacy.

  10. Detectability of liver metastases in malignant melanoma: prospective comparison of magnetic resonance imaging and positron emission tomography

    Ghanem, Nadir [Departments of Diagnostic Radiology, University Hospital Freiburg, Freiburg 79106 (Germany)]. E-mail: gha@mrs1.ukl.uni-freiburg.de; Altehoefer, Carsten [Departments of Diagnostic Radiology, University Hospital Freiburg, Freiburg 79106 (Germany); Hoegerle, Stefan [Departments of Nuclear Medicine, University Hospital Freiburg, Freiburg (Germany); Nitzsche, Egbert [Departments of Nuclear Medicine, University Hospital Freiburg, Freiburg (Germany); Lohrmann, Christian [Departments of Diagnostic Radiology, University Hospital Freiburg, Freiburg 79106 (Germany); Schaefer, Oliver [Departments of Diagnostic Radiology, University Hospital Freiburg, Freiburg 79106 (Germany); Kotter, Elmar [Departments of Diagnostic Radiology, University Hospital Freiburg, Freiburg 79106 (Germany); Langer, Mathias [Departments of Diagnostic Radiology, University Hospital Freiburg, Freiburg 79106 (Germany)

    2005-05-01

    Purpose: We evaluated the diagnostic accuracy of magnetic resonance imaging (MRI) and positron emission tomography (PET) for detection of liver metastases in malignant melanoma. Material and methods: Thirty-five patients with 39 combined unenhanced MRI and fluorine-18 deoxyglucose (F-18 FDG) PET scans were prospectively studied. In discordant imaging findings final diagnosis was proven by clinical follow-up >6 months and demonstration of progressive liver metastases by at least one imaging method. Sensitivities and specificities were compared and the influence of lesion size and melanin content on diagnostic accuracy was determined. Results: MRI and PET were concordantly negative for presence and number of liver metastases in 28 patients and positive in four patients. PET and MRI were false positive in one patient each. In one patient MRI showed a single metastases not seen by PET and in one patient MRI demonstrated more metastases at the first examination. In follow-up investigations MRI revealed more metastases than PET in both patients. The sensitivities for lesion detection were 47% (16/34) for PET and 100% for MRI. Lesion detectability by PET was related to lesion size (P < 0.0001) but not to melanin content. Conclusion: MRI is more sensitive in the detection of liver metastases in patients with malignant melanoma. Small lesions are easily missed by PET, while melanin content does not influence detectability by PET.

  11. Insufficiency of Positron Emission Tomography and Magnetic Resonance Spectroscopy in the Diagnosis of Intravascular Lymphoma of the Central Nervous System

    Nobuyuki Kawai

    2012-07-01

    Full Text Available Intravascular large B-cell lymphoma (IVL is a rare type of extranodal lymphoma with an aggressive clinical course characterized by the proliferation of lymphoma cells within the lumen of small vessels. Diagnosis is often difficult because of marked variability in clinical presentation and nonspecific laboratory and radiological findings, especially when central nervous system (CNS symptoms are the only manifestation. Modern metabolic imaging techniques such as positron emission tomography (PET and 1H-magnetic resonance spectroscopy (MRS have been reported to be useful in the diagnosis of conventional primary CNS lymphoma. We report the case of a 69-year-old man who presented with a progressive leukoencephalopathic syndrome. The patient was examined by 18F-fluorodeoxyglucose and 11C-methionine PET and MRS, but none of these examinations were able to show the presence of a tumor in the lesions or to clarify the tumor characteristics. Brain biopsy was the only way to obtain a definite diagnosis of IVL. The patient was treated intensively with standard immunochemotherapy but died 6 months after the diagnosis. Here, we discuss the insufficiency of modern metabolic imaging techniques, including PET and MRS, and recommend a rapid decision of brain biopsy in the diagnosis of IVL only involving the CNS.

  12. Different subregional metabolism patterns in patients with cerebellar ataxia by 18F-fluorodeoxyglucose positron emission tomography

    Kim, Jae Seung; Oh, Jungsu S.; Lee, Chong Sik; Chung, Sun Ju

    2017-01-01

    We evaluated cerebellar subregional metabolic alterations in patients with cerebellar ataxia, a representative disease involving the spinocerebellum. We retrospectively analyzed 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) images in 44 patients with multiple system atrophy of the cerebellar type (MSA-C), 9 patients with spinocerebellar ataxia (SCA) type 2, and 14 patients with SCA type 6 and compared with 15 patients with crossed cerebellar diaschisis (CCD) and 89 normal controls. Cerebellar subregional metabolism was assessed using 13 cerebellar subregions (bilateral anterior lobes [ANT], superior/mid/inferior posterior lobes [SUPP/MIDP/INFP], dentate nucleus [DN], anterior vermis [ANTV], and superior/inferior posterior vermis [SUPV/INFV]) to determine FDG uptake ratios. MSA-C and SCA type 2 showed severely decreased metabolic ratios in all cerebellar subregions compared to normal controls (ANT, 0.58 ± 0.08 and 0.50 ± 0.06 vs. 0.82 ± 0.07, respectively, p MSA-C. Asymmetric indices were higher in CCD and MSA-C than in normal controls (p MSA-C exhibited more asymmetric hypometabolism in the posterior lobe. PMID:28319124

  13. Tumor-Specific Targeting With Modified Sindbis Viral Vectors: Evaluation with Optical Imaging and Positron Emission Tomography In Vivo

    Stelter, Lars; Tseng, Jen-Chieh; Torosjan, Armen; Levin, Brandi; Longo, Valerie A.; Pillarsetty, Nagavarakishore; Zanzonico, Pat; Meruelo, Daniel; Daniel, Steven M.

    2015-01-01

    Purpose Sindbis virus (SINV) infect tumor cells specifically and systemically throughout the body. Sindbis vectors are capable of expressing high levels of transduced suicide genes and thus efficiently produce enzymes for prodrug conversion in infected tumor cells. The ability to monitor suicide gene expression levels and viral load in patients, after administration of the vectors, would significantly enhance this tumor-specific therapeutic option. Procedures The tumor specificity of SINV is mediated by the 67-kDa laminin receptor (LR). We probed different cancer cell lines for their LR expression and, to determine the specific role of LR-expression in the infection cycle, used different molecular imaging strategies, such as bioluminescence, fluorescence molecular tomography, and positron emission tomography, to evaluate SINV-mediated infection in vitro and in vivo. Results All cancer cell lines showed a marked expression of LR. The infection rates of the SINV particles, however, differed significantly among the cell lines. Conclusion We used novel molecular imaging techniques to visualize vector delivery to different neoplatic cells. SINV infection rates proofed to be not solely dependent on cellular LR expression. Further studies need to evaluate the herein discussed ways of cellular infection and viral replication. PMID:22847302

  14. Development of a resonant-type microwave reactor and its application to the synthesis of positron emission tomography radiopharmaceuticals.

    Kimura, Hiroyuki; Yagi, Yusuke; Ohneda, Noriyuki; Odajima, Hiro; Ono, Masahiro; Saji, Hideo

    2014-10-01

    Microwave technology has been successfully applied to enhance the effectiveness of radiolabeling reactions. The use of a microwave as a source of heat energy can allow chemical reactions to proceed over much shorter reaction times and in higher yields than they would do under conventional thermal conditions. A microwave reactor developed by Resonance Instrument Inc. (Model 520/521) and CEM (PETWave) has been used exclusively for the synthesis of radiolabeled agents for positron emission tomography by numerous groups throughout the world. In this study, we have developed a novel resonant-type microwave reactor powered by a solid-state device and confirmed that this system can focus microwave power on a small amount of reaction solution. Furthermore, we have demonstrated the rapid and facile radiosynthesis of 16α-[(18)F]fluoroestradiol, 4-[(18)F]fluoro-N-[2-(1-methoxyphenyl)-1-piperazinyl]ethyl-N-2-pyridinylbenzamide, and N-succinimidyl 4-[(18)F]fluorobenzoate using our newly developed microwave reactor.

  15. Studies on functional roles of the histaminergic neuron system by using pharmacological agents, knockout mice and positron emission tomography

    Watanabe, Takehiko; Yanai, Kazuhiko [Tohoku Univ., Sendai (Japan). Graduate School of Medicine

    2001-12-01

    Since one of us, Takehiko Watanabe (TW), elucidated the location and distribution of the histaminergic neuron system in the brain with antibody raised against L-histidine decarboxylase (a histamine-forming enzyme, HDC) as a marker in 1984 and came to Tohoku University School of Medicine in Sendai, we have been collaborating on the functions of this neuron system by using pharmacological agents, knockout mice of the histamine-related genes, and, in some cases, positron emission tomography (PET). Many of our graduate students and colleagues have been actively involved in histamine research since 1985. Our extensive studies have clarified some of the functions of histamine neurons using methods from molecular techniques to non-invasive human PET imaging. Histamine neurons are involved in many brain functions, such as spontaneous locomotion, arousal in wake-sleep cycle, appetite control, seizures, learning and memory, aggressive behavior and emotion. Particularly, the histaminergic neuron system is one of the most important neuron systems to maintain and stimulate wakefulness. Histamine also functions as a biprotection system against various noxious and unfavorable stimuli (for examples, convulsion, nociception, drug sensitization, ischemic lesions, and stress). Although activators of histamine neurons have not been clinically available until now, we would like to point out that the activation of the histaminergic neuron system is important to maintain mental health. Here, we summarize the newly-discovered functions of histamine neurons mainly on the basis of results from our research groups. (author)

  16. (18)F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Malignancies of the Thyroid and in Head and Neck Squamous Cell Carcinoma

    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-PET......-PET/CT in malignancies of the thyroid gland and in head and neck squamous cell carcinoma....

  17. Pancreatic tuberculosis: Evaluation of therapeutic response using F-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography.

    Santhosh, Sampath; Bhattacharya, Anish; Rana, Surinder Singh; Bhasin, Deepak Kumar; Srinivasan, Radhika; Mittal, Bhagwant Rai

    2014-10-01

    F-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG PET/CT) is a functional imaging technique that monitors glucose metabolism in tissues. Pulmonary tuberculosis (TB) has been reported to show intense uptake of FDG, with a decrease in metabolism of the tuberculous lesions after successful anti-tubercular treatment (ATT). The authors present a patient with pancreatic TB and demonstrate the usefulness of FDG PET/CT in monitoring the response to ATT.

  18. Noninvasive evaluation of active pan-ulcerative colitis with multiple strictures using Fluorine-18-Fluorodeoxyglucose positron emission tomography/computed tomography.

    Santhosh, Sampath; Bhattacharya, Anish; Rana, Surinder Singh; Bhasin, Deepak Kumar; Gupta, Rajesh; Mittal, Bhagwant Rai

    2016-01-01

    Ulcerative colitis (UC) is an inflammatory bowel disease characterized by waxing and waning inflammation that changes in severity and extent and may progress to neoplasia, especially in the presence of strictures. When patients have nonnegotiable strictures or severe inflammation with ulcers, colonoscopy is difficult and carries the risk of perforation. The authors present a patient with pan-UC with multiple strictures, in whom fluorodeoxyglucose positron emission tomography/computed tomography was used to noninvasively evaluate the extent and severity of the disease.

  19. Review of cardiovascular imaging in the journal of nuclear cardiology in 2015. Part 1 of 2: Plaque imaging, positron emission tomography, computed tomography, and magnetic resonance.

    AlJaroudi, Wael A; Hage, Fadi G

    2016-02-01

    In 2015, many original articles pertaining to cardiovascular imaging with impressive quality were published in the Journal of Nuclear Cardiology. In a set of 2 articles, we provide an overview of these contributions to facilitate for the interested reader a quick review of the advancements that occurred in the field over this year. In this first article, we focus on arterial plaque imaging, cardiac positron emission tomography, computed tomography, and magnetic resonance imaging.

  20. 18F-fluorodeoxyglucose positron emission tomography-computed tomography finding of left gonadal vein thrombosis in a case of renal cell carcinoma.

    Narayan, Ravishwar; Ravishankar, Uma; Natarajan, Savita; Vohra, Sandeep

    2016-01-01

    Tumor thrombus from renal cell carcinoma is commonly reported in renal vein and inferior vena cava with a few reports of gonadal vein involvement. Here, we report a case of an elderly female who underwent fluorodeoxyglucose (FDG) positron emission tomography-computed tomography scan for initial staging of left renal cell carcinoma. Along with an FDG avid left renal mass lesion, scan also revealed FDG avid tumor thrombus in the entire length of the left gonadal vein.

  1. Noninvasive Visualization of the Activated alphavbeta3 Integrin in Cancer Patients by Positron Emission Tomography and [18F]Galacto-RGD

    Haubner Roland; Weber Wolfgang A; Beer Ambros J; Vabuliene Eugenija; Reim Daniel; Sarbia Mario; Becker Karl-Friedrich; Goebel Michael; Hein Rüdiger; Wester Hans-Jürgen; Kessler Horst; Schwaiger Markus

    2005-01-01

    Background The integrin alphavbeta3 plays an important role in angiogenesis and tumor cell metastasis, and is currently being evaluated as a target for new therapeutic approaches. Several techniques are being studied to enable noninvasive determination of alphavbeta3 expression. We developed [18F]Galacto-RGD, a 18F-labeled glycosylated alphavbeta3 antagonist, allowing monitoring of alphavbeta3 expression with positron emission tomography (PET). Methods and Findings Here we show by quantita...

  2. [18F]FDG and [18F]FLT positron emission tomography imaging following treatment with belinostat in human ovary cancer xenografts in mice

    Jensen, Mette Munk; Erichsen, Kamille Dumong; Johnbeck, Camilla Bardram;

    2013-01-01

    Belinostat is a histone deacetylase inhibitor with anti-tumor effect in several pre-clinical tumor models and clinical trials. The aim of the study was to evaluate changes in cell proliferation and glucose uptake by use of 3'-deoxy-3'-[(18)F]fluorothymidine ([18F]FLT) and 2-deoxy-2-[(18)F]fluoro-......]fluoro-D-glucose ([18F]FDG) positron emission tomography (PET) following treatment with belinostat in ovarian cancer in vivo models....

  3. Ro 15-1788-C/sup 11/ and flunitrazepam-C/sup 11/; two coordinates for the study of benzodiazepines binding sites by positron emission tomography

    Maziere, M.; Prenant, C.; Sastre, J.; Crouzel, M.; Comar, D. (C.E.A., Orsay (France)); Hantraye, P.; Kaisima, M.; Guibert, B.; Naquet, R. (C.N.R.S., Gif-sur-Yvette (France))

    1983-05-16

    In vivo binding of a benzodiazepine (flunitrazepam-C/sup 11/) and a benzodiazepine antagonist (Ro 15-1788-C/sup 11/) were studied with positron emission tomography. Advantages and disadvantages of each drug for studying specific in vivo binding sites are presented. The results obtained indicate that Ro 15-1788-C/sup 11/ is a better in vivo radiocoordinat than flunitrazepam-C/sup 11/.

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

    Maximilien Brice

    2004-01-01

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

  5. Positron emission tomography using F-18-fluoro-deoxyglucose and euglycaemic hyperinsulinaemic glucose clamp : optimal criteria for the prediction of recovery of post-ischaemic left ventricular dysfunction - Results from the European Community Concerted Action Multicenter study on use of F-18-fluoro-deoxyglucose Positron Emission Tomography for the Detection of Myocardial Viability

    Gerber, BL; Ordoubadi, FF; Wijns, W; Vanoverschelde, JLJ; Knuuti, MJ; Janier, M; Melon, P; Blanksma, PK; Bol, A; Bax, JJ; Melin, JA; Camici, PG

    2001-01-01

    Aims To assess the accuracy of positron emission tomography to predict recovery of global cardiac function after revascularization in patients with coronary artery disease. Methods and Results One hundred and seventy-eight patients (157 male, 58 +/- 10 years) with coronary artery disease and left ve

  6. Concept and simulation study of a novel localization method for robotic endoscopic capsules using multiple positron emission markers

    Than, Trung Duc, E-mail: dtt581@uowmail.edu.au; Alici, Gursel, E-mail: gursel@uow.edu.au; Zhou, Hao, E-mail: hz467@uowmail.edu.au; Li, Weihua, E-mail: weihuali@uow.edu.au [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Harvey, Steven, E-mail: steven.harvey@sesiahs.health.nsw.gov.au [Department of Nuclear Medicine, Wollongong Hospital, New South Wales 2500 (Australia)

    2014-07-15

    Purpose: Over the last decade, wireless capsule endoscope has been the tool of choice for noninvasive inspection of the gastrointestinal tract, especially in the small intestine. However, the latest clinical products have not been equipped with a sufficiently accurate localization system which makes it difficult to determine the location of intestinal abnormalities, and to apply follow-up interventions such as biopsy or drug delivery. In this paper, the authors present a novel localization method based on tracking three positron emission markers embedded inside an endoscopic capsule. Methods: Three spherical {sup 22}Na markers with diameters of less than 1 mm are embedded in the cover of the capsule. Gamma ray detectors are arranged around a patient body to detect coincidence gamma rays emitted from the three markers. The position of each marker can then be estimated using the collected data by the authors’ tracking algorithm which consists of four consecutive steps: a method to remove corrupted data, an initialization method, a clustering method based on the Fuzzy C-means clustering algorithm, and a failure prediction method. Results: The tracking algorithm has been implemented inMATLAB utilizing simulation data generated from the Geant4 Application for Emission Tomography toolkit. The results show that this localization method can achieve real-time tracking with an average position error of less than 0.4 mm and an average orientation error of less than 2°. Conclusions: The authors conclude that this study has proven the feasibility and potential of the proposed technique in effectively determining the position and orientation of a robotic endoscopic capsule.

  7. Comparison of fluorine-18 fluorodeoxyglucose positron emission tomography and technetium-99m methoxyisobutylisonitrile scintimammography in the detection of breast tumours

    Palmedo, H.; Bender, H.; Gruenwald, F.; Zamora, P.; Biersack, H.J. [Department of Nuclear Medicine, University of Bonn (Germany); Mallmann, P.; Krebs, D. [Department of Gynecology and Obstetrics, University of Bonn (Germany)

    1997-09-01

    The aim of this study was to compare, in breast cancer patients, the diagnostic accuracy of positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) and scintimammography (SMM) using technetium-99m methoxyisobutylisonitrile (MIBI). A total of 20 patients (40 breasts with 22 lesions) were evaluated serially with MIBI and, on the following day, with FDG. For SMM, planar and single-photon emission tomography imaging in the prone position was performed starting at 10 min following the injection of MIBI (740 MBq). For PET, scans were acquired 45-60 min after the injection of FDG (370 MBq) and attentuation correction was performed following transmission scans. Results from SMM and PET were subsequently compared with the histopathology results. True-positive results were obtained in 12/13 primary breast cancers (mean diameter=29 mm, range 8-53 mm) with both FDG and MIBI. False-negative results were obtained in two local recurrences (diameter <9 mm) with both FDG and MIBI. In benign disease, FDG and MIBI did not localize three fibrocystic lesions, two fibroadenomas and one inflammatory lesion (true-negative), but both localized one fibroadenoma (false-positive). Collectively, the results demonstrate a sensitivity of 92%, and a specificity of 86%, for primary breast cancer regardless of whether FDG or MIBI was used. In contrast to MIBI scintigraphy, FDG PET scored the axillae correctly as either positive (metastatic disease) or negative (no axillary disease) in all 12 patients. The tumour/non-tumour ratio for MIBI was 1.97 (range 1.43-3.1). The mean standard uptake value (SUV) for FDG uptake was 2.57 (range 0.3-6.2). The diagnostic accuracy of SMM was equivalent to that of FDG PET for the detection of primary breast cancer. For the detection of in situ lymph node metastases of the axilla, FDG seems to be more sensitive than {sup 99m}Tc-MIBI. (orig.). With 4 figs., 2 tabs.

  8. Positron emission tomography and [{sup 18}F]BPA: A perspective application to assess tumour extraction of boron in BNCT

    Menichetti, L. [Department of PET and Radiopharmaceutical Chemistry, C.N.R. Institute of Clinical Physiology, Pisa (Italy)], E-mail: luca.menichetti@ifc.cnr.it; Cionini, L. [Unit of Radiotherapy, AOUP-University Hospital, Pisa (Italy); Sauerwein, W.A. [Department of Radiation Oncology, University Duisburg-Essen, University Hospital Essen (Germany); Altieri, S. [University of Pavia, Department of Nuclear Physics, Pavia (Italy); Solin, O.; Minn, H. [Turku PET Centre, University of Turku (Finland); Salvadori, P.A. [Department of PET and Radiopharmaceutical Chemistry, C.N.R. Institute of Clinical Physiology, Pisa (Italy)

    2009-07-15

    Positron emission tomography (PET) has become a key imaging tool in clinical practice and biomedical research to quantify and study biochemical processes in vivo. Physiologically active compounds are tagged with positron emitters (e.g. {sup 18}F, {sup 11}C, {sup 124}I) while maintaining their biological properties, and are administered intravenously in tracer amounts (10{sup -9}-10{sup -12} M quantities). The recent physical integration of PET and computed tomography (CT) in hybrid PET/CT scanners allows a combined anatomical and functional imaging: nowadays PET molecular imaging is emerging as powerful pharmacological tool in oncology, neurology and for treatment planning as guidance for radiation therapy. The in vivo pharmacokinetics of boron carrier for BNCT and the quantification of {sup 10}B in living tissue were performed by PET in the late nineties using compartmental models based on PET data. Nowadays PET and PET/CT have been used to address the issue of pharmacokinetic, metabolism and accumulation of BPA in target tissue. The added value of the use of L-[{sup 18}F]FBPA and PET/CT in BNCT is to provide key data on the tumour extraction of {sup 10}B-BPA versus normal tissue and to predict the efficacy of the treatment based on a single-study patient analysis. Due to the complexity of a binary treatment like BNCT, the role of PET/CT is currently to design new criteria for patient enrolment in treatment protocols: the L-[{sup 18}F]BPA/PET methodology could be considered as an important tool in newly designed clinical trials to better estimate the concentration ratio of BPA in the tumour as compared to neighbouring normal tissues. Based on these values for individual patients the decision could be made whether BNCT treatment could be advantageous due to a selective accumulation of BPA in an individual tumour. This approach, applicable in different tumour entities like melanoma, glioblastoma and head and neck malignancies, make this methodology as reliable

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

    Petersen, Anncatrine L; Binderup, Tina; Jølck, Rasmus I; Rasmussen, Palle; Henriksen, Jonas R; Pfeifer, Andreas K; Kjær, Andreas; Andresen, Thomas L

    2012-06-10

    Targeted therapeutic and diagnostic nanocarriers functionalized with antibodies, peptides or other targeting ligands that recognize over-expressed receptors or antigens on tumor cells have potential in the diagnosis and therapy of cancer. Somatostatin receptors (SSTRs) are over-expressed in a variety of cancers, particularly neuroendocrine tumors (NETs) and can be targeted with somatostatin peptide analogs such as octreotate (TATE). In the present study we investigate liposomes that target SSTR in a NET xenograft mouse model (NCI-H727) by use of TATE. TATE was covalently attached to the distal end of DSPE-PEG(2000) on PEGylated liposomes with an encapsulated positron emitter (64)Cu that can be utilized for positron emission tomography (PET) imaging. The biodistribution and pharmacokinetics of the (64)Cu-loaded PEGylated liposomes with and without TATE was investigated and their ability to image NETs was evaluated using PET. Additionally, the liposome accumulation and imaging capability was compared with free radiolabelled TATE peptide administered as (64)Cu-DOTA-TATE. The presence of TATE on the liposomes resulted in a significantly faster initial blood clearance in comparison to control-liposomes without TATE. PEGylated liposomes with or without TATE accumulated at significantly higher quantities in NETs (5.1±0.3 and 5.8±0.2 %ID/g, respectively) than the free peptide (64)Cu-DOTA-TATE (1.4±0.3 %ID/g) 24 h post-injection. Importantly, (64)Cu-loaded PEGylated liposomes with TATE showed significantly higher tumor-to-muscle (T/M) ratio (12.7±1.0) than the control-liposomes without TATE (8.9±0.9) and the (64)Cu-DOTA-TATE free peptide (7.2±0.3). The higher T/M ratio of the PEGylated liposomes with TATE suggests some advantage of active targeting of NETs, although no absolute benefit in tumor accumulation over the non-targeted liposomes was observed. Collectively, these data showed that (64)Cu-loaded PEGylated liposomes with TATE conjugated to the surface could be

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

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

    2013-01-01

    emission tomography (PET) with (11)C-Pittsburgh compound B (PiB) and 18F-fluoro-2-deoxy-d-glucose (FDG). These included 19 NL with a maternal history (MH), 12 NL with a paternal history (PH), and 16 NL with negative family history of AD (NH). Automated regions of interest, statistical parametric mapping......, voxel-wise intermodality correlations, and logistic regressions were used to examine cerebral-to-cerebellar PiB and FDG standardized uptake value ratios across groups. The MH group showed higher PiB retention and lower metabolism in AD regions compared with NH and PH, which were negatively correlated...

  11. 18F-FLT Positron Emission Tomography/Computed Tomography Imaging in Pancreatic Cancer: Determination of Tumor Proliferative Activity and Comparison with Glycolytic Activity as Measured by 18F-FDG Positron Emission Tomography/Computed Tomography Imaging

    Senait Aknaw Debebe

    2016-02-01

    Full Text Available Objective: This phase-I imaging study examined the imaging characteristic of 3’-deoxy-3’-(18F-fluorothymidine (18F-FLT positron emission tomography (PET in patients with pancreatic cancer and comparisons were made with (18F-fluorodeoxyglucose (18F-FDG. The ultimate aim was to develop a molecular imaging tool that could better define the biologic characteristics of pancreas cancer, and to identify the patients who could potentially benefit from surgical resection who were deemed inoperable by conventional means of staging. Methods: Six patients with newly diagnosed pancreatic cancer underwent a combined FLT and FDG computed tomography (CT PET/CT imaging protocol. The FLT PET/CT scan was performed within 1 week of FDG PET/CT imaging. Tumor uptake of a tracer was determined and compared using various techniques; statistical thresholding (z score=2.5, and fixed standardized uptake value (SUV thresholds of 1.4 and 2.5, and applying a threshold of 40% of maximum SUV (SUVmax and mean SUV (SUVmean. The correlation of functional tumor volumes (FTV between 18F-FDG and 18F-FLT was assessed using linear regression analysis. Results: It was found that there is a correlation in FTV due to metabolic and proliferation activity when using a threshold of SUV 2.5 for FDG and 1.4 for FLT (r=0.698, p=ns, but a better correlation was obtained when using SUV of 2.5 for both tracers (r=0.698, p=ns. The z score thresholding (z=2.5 method showed lower correlation between the FTVs (r=0.698, p=ns of FDG and FLT PET. Conclusion: Different tumor segmentation techniques yielded varying degrees of correlation in FTV between FLT and FDGPET images. FLT imaging may have a different meaning in determining tumor biology and prognosis.

  12. Detection of neuronal damage in degenerative brain disease with cobalt-55 and positron emission tomography

    Jansen, H.M.L.; Pruim, J.; Paans, A.M.J. [Univ. Hospital Groningen (Netherlands)] [and others

    1994-05-01

    We suggest Cobalt-55 (Co) as a Calcium (Ca)-marker to visualize Ca transport across the neuronal membrane. Elevation of intracellular Ca is closely linked with the process of neuronal cell-decay. Co-uptake is correlated with Ca-accumulation through divalent cation-permeable kainate (KA)-activated receptor-operated channels in the neuronal membrane. This hypothesis was studied with position emission tomography (PET) both in patients with a ischemic cerebro-vascular accident (CVA) and in patients with relapsing progressive multiple sclerosis (MS). Co-PET studies were performed in a dynamic mode (6 frames of 10 minutes) 20-25 hours after iv.-administration of 1-2 mCi Co. Regional specific accumulation irrespective of blood brain barrier (BBB) integrity in the (clinically appropriate) affected cerebral region could be demonstrated in CVA-patients, thus suggesting neuronal decay in (the early phase of) infarction. In MS, inhomogeneous cerebral distribution of Co was detected, in contrast to healthy volunteers. This suggests focal accumulation of Co in multiple spots of neuronal decay, possibly related to MS-lesions on MRI. In conclusion, Co-PET may prove to be a valuable tool for the early detection of neuronal decay not only in CVA and MS, but in other brain-pathology as well. The usefulness of Co-PET in imaging brain-tumors and myocardial ischemia has already been established.

  13. List-mode image reconstruction for positron emission tomography using tetrahedral voxels

    Gillam, John E.; Angelis, Georgios I.; Meikle, Steven R.

    2016-09-01

    Image space decomposition based on tetrahedral voxels are interesting candidates for use in emission tomography. Tetrahedral voxels provide many of the advantages of point clouds with irregular spacing, such as being intrinsically multi-resolution, yet they also serve as a volumetric partition of the image space and so are comparable to more standard cubic voxels. Additionally, non-rigid displacement fields can be applied to the tetrahedral mesh in a straight-forward manner. So far studies incorporating tetrahedral decomposition of the image space have concentrated on pre-calculated, node-based, system matrix elements which reduces the flexibility of the tetrahedral approach and the capacity to accurately define regions of interest. Here, a list-mode on-the-fly calculation of the system matrix elements is described using a tetrahedral decomposition of the image space and volumetric elements—voxels. The algorithm is demonstrated in the context of awake animal PET which may require both rigid and non-rigid motion compensation, as well as quantification within small regions of the brain. This approach allows accurate, event based, motion compensation including non-rigid deformations.

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

    Kuhl, D.E.

    1992-01-01

    The general goals of the physics and kinetic modeling projects are to: (1) improve the quantitative information extractable from PET images, and (2) develop, implement and optimize tracer kinetic models for new PET neurotransmitter/receptor ligands aided by computer simulations. Work towards improving PET quantification has included projects evaluating: (1) iterative reconstruction algorithms using supplemental boundary information, (2) automated registration of dynamic PET emission and transmission data using sinogram edge detection, and (3) automated registration of multiple subjects to a common coordinate system, including the use of non-linear warping methods. Simulation routines have been developed providing more accurate representation of data generated from neurotransmitter/receptor studies. Routines consider data generated from complex compartmental models, high or low specific activity administrations, non-specific binding, pre- or post-injection of cold or competing ligands, temporal resolution of the data, and radiolabeled metabolites. Computer simulations and human PET studies have been performed to optimize kinetic models for four new neurotransmitter/receptor ligands, ({sup 11}C)TRB (muscarinic), ({sup 11}C)flumazenil (benzodiazepine), ({sup 18}F)GBR12909, (dopamine), and ({sup 11}C)NMPB (muscarinic).

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

    Kuhl, D.E.

    1992-07-01

    The general goals of the physics and kinetic modeling projects are to: (1) improve the quantitative information extractable from PET images, and (2) develop, implement and optimize tracer kinetic models for new PET neurotransmitter/receptor ligands aided by computer simulations. Work towards improving PET quantification has included projects evaluating: (1) iterative reconstruction algorithms using supplemental boundary information, (2) automated registration of dynamic PET emission and transmission data using sinogram edge detection, and (3) automated registration of multiple subjects to a common coordinate system, including the use of non-linear warping methods. Simulation routines have been developed providing more accurate representation of data generated from neurotransmitter/receptor studies. Routines consider data generated from complex compartmental models, high or low specific activity administrations, non-specific binding, pre- or post-injection of cold or competing ligands, temporal resolution of the data, and radiolabeled metabolites. Computer simulations and human PET studies have been performed to optimize kinetic models for four new neurotransmitter/receptor ligands, [{sup 11}C]TRB (muscarinic), [{sup 11}C]flumazenil (benzodiazepine), [{sup 18}F]GBR12909, (dopamine), and [{sup 11}C]NMPB (muscarinic).

  16. Modelisation de photodetecteurs a base de matrices de diodes avalanche monophotoniques pour tomographie d'emission par positrons

    Corbeil Therrien, Audrey

    La tomographie d'emission par positrons (TEP) est un outil precieux en recherche preclinique et pour le diagnostic medical. Cette technique permet d'obtenir une image quantitative de fonctions metaboliques specifiques par la detection de photons d'annihilation. La detection des ces photons se fait a l'aide de deux composantes. D'abord, un scintillateur convertit l'energie du photon 511 keV en photons du spectre visible. Ensuite, un photodetecteur convertit l'energie lumineuse en signal electrique. Recemment, les photodiodes avalanche monophotoniques (PAMP) disposees en matrice suscitent beaucoup d'interet pour la TEP. Ces matrices forment des detecteurs sensibles, robustes, compacts et avec une resolution en temps hors pair. Ces qualites en font un photodetecteur prometteur pour la TEP, mais il faut optimiser les parametres de la matrice et de l'electronique de lecture afin d'atteindre les performances optimales pour la TEP. L'optimisation de la matrice devient rapidement une operation difficile, car les differents parametres interagissent de maniere complexe avec les processus d'avalanche et de generation de bruit. Enfin, l'electronique de lecture pour les matrices de PAMP demeure encore rudimentaire et il serait profitable d'analyser differentes strategies de lecture. Pour repondre a cette question, la solution la plus economique est d'utiliser un simulateur pour converger vers la configuration donnant les meilleures performances. Les travaux de ce memoire presentent le developpement d'un tel simulateur. Celui-ci modelise le comportement d'une matrice de PAMP en se basant sur les equations de physique des semiconducteurs et des modeles probabilistes. Il inclut les trois principales sources de bruit, soit le bruit thermique, les declenchements intempestifs correles et la diaphonie optique. Le simulateur permet aussi de tester et de comparer de nouvelles approches pour l'electronique de lecture plus adaptees a ce type de detecteur. Au final, le simulateur vise a

  17. Positron emission tomographic monitoring of dual phosphatidylinositol-3-kinase and mTOR inhibition in anaplastic large cell lymphoma

    Graf N

    2014-05-01

    Full Text Available Nicolas Graf,1 Zhoulei Li,2 Ken Herrmann,2,4 Daniel Weh,2 Michaela Aichler,3 Jolanta Slawska,2 Axel Walch,3 Christian Peschel,1 Markus Schwaiger,2 Andreas K Buck,2,4 Tobias Dechow,1,* Ulrich Keller1,* 1III Medical Department, 2Department of Nuclear Medicine, Technische Universität München, Munich, Germany; 3Research Unit Analytical Pathology, Helmholtz Zentrum München, Munich, Germany; 4Department of Nuclear Medicine, Universitätsklinikum Würzburg, Würzburg, Germany *These authors contributed equally to this work Background: Dual phosphatidylinositol-3-kinase (PI3K/mammalian target of rapamycin (mTOR inhibition offers an attractive therapeutic strategy in anaplastic large cell lymphoma depending on oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK signaling. We tested the efficacy of a novel dual PI3K/mTOR inhibitor, NVP-BGT226 (BGT226, in two anaplastic large cell lymphoma cell lines in vitro and in vivo and performed an early response evaluation with positron emission tomography (PET imaging using the standard tracer, 2-deoxy-2-[18F]fluoro-D-glucose (FDG and the thymidine analog, 3'-deoxy-3'-[18F]fluorothymidine (FLT. Methods: The biological effects of BGT226 were determined in vitro in the NPM-ALK positive cell lines SU-DHL-1 and Karpas299 by 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, propidium iodide staining, and biochemical analysis of PI3K and mTOR downstream signaling. FDG-PET and FLT-PET were performed in immunodeficient mice bearing either SU-DHL-1 or Karpas299 xenografts at baseline and 7 days after initiation of treatment with BGT226. Lymphomas were removed for immunohistochemical analysis of proliferation and apoptosis to correlate PET findings with in vivo treatment effects. Results: SU-DHL-1 cells showed sensitivity to BGT226 in vitro, with cell cycle arrest in G0/G1 phase and an IC50 in the low nanomolar range, in contrast with Karpas299 cells, which were mainly resistant to BGT226. In

  18. Motion compensation using origin ensembles in awake small animal positron emission tomography

    Gillam, John E.; Angelis, Georgios I.; Kyme, Andre Z.; Meikle, Steven R.

    2017-02-01

    In emission tomographic imaging, the stochastic origin ensembles algorithm provides unique information regarding the detected counts given the measured data. Precision in both voxel and region-wise parameters may be determined for a single data set based on the posterior distribution of the count density allowing uncertainty estimates to be allocated to quantitative measures. Uncertainty estimates are of particular importance in awake animal neurological and behavioral studies for which head motion, unique for each acquired data set, perturbs the measured data. Motion compensation can be conducted when rigid head pose is measured during the scan. However, errors in pose measurements used for compensation can degrade the data and hence quantitative outcomes. In this investigation motion compensation and detector resolution models were incorporated into the basic origin ensembles algorithm and an efficient approach to computation was developed. The approach was validated against maximum liklihood—expectation maximisation and tested using simulated data. The resultant algorithm was then used to analyse quantitative uncertainty in regional activity estimates arising from changes in pose measurement precision. Finally, the posterior covariance acquired from a single data set was used to describe correlations between regions of interest providing information about pose measurement precision that may be useful in system analysis and design. The investigation demonstrates the use of origin ensembles as a powerful framework for evaluating statistical uncertainty of voxel and regional estimates. While in this investigation rigid motion was considered in the context of awake animal PET, the extension to arbitrary motion may provide clinical utility where respiratory or cardiac motion perturb the measured data.

  19. A procedure for wall detection in [{sup 18}F]FDG positron emission tomography heart studies

    Landoni, C. [INB CNR, Dept. of Nuclear Medicine, Milan Univ., Inst. H San Raffaele (Italy); Bettinardi, V. [INB CNR, Dept. of Nuclear Medicine, Milan Univ., Inst. H San Raffaele (Italy); Lucignani, G. [INB CNR, Dept. of Nuclear Medicine, Milan Univ., Inst. H San Raffaele (Italy); Gilardi, M.C. [INB CNR, Dept. of Nuclear Medicine, Milan Univ., Inst. H San Raffaele (Italy); Striano, G. [INB CNR, Dept. of Nuclear Medicine, Milan Univ., Inst. H San Raffaele (Italy); Fazio, F. [INB CNR, Dept. of Nuclear Medicine, Milan Univ., Inst. H San Raffaele (Italy)

    1996-01-01

    We implemented a data processing technique to improve the accuracy of the localization of ROIs on the MW and LV in fluorine-18 labelled deoxyglucose ([{sup 18}F]FDG) PET heart studies. This technique combines transmission data, acquired before tracer administration and used for attenuation correction, and dynamic emission data (DY), acquired to obtain myocardial time-activity curves and used to calculate regional myocardial glucose utilization, to generate a new set of `transmission` images (TRDY) with enhanced contrast between MW and LV. These new transmission images identify the extravascular myocardial tissue and can be used for ROI placement. Validation of the method was performed in 25 patients, studied after an oral glucose load, by drawing irregular ROIs on three transaxial slices outlining the septum and anteriorapical and lateral was on the last frame of the DY im