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Sample records for particulate pet perfusion

  1. Simultaneous cardiac output and regional myocardial perfusion determination with PET and nitrogen 13 ammonia

    DEFF Research Database (Denmark)

    Hove, Jens D; Kofoed, Klaus F; Wu, Hsiao M

    2003-01-01

    The purpose of this study was to evaluate the possibility of measuring cardiac output during positron emission tomography (PET) examination of myocardial perfusion with nitrogen 13 ammonia.......The purpose of this study was to evaluate the possibility of measuring cardiac output during positron emission tomography (PET) examination of myocardial perfusion with nitrogen 13 ammonia....

  2. Perfusion imaging using rubidium-82 ((82)Rb) PET in rats with myocardial infarction

    DEFF Research Database (Denmark)

    Clemmensen, Andreas Ettrup; Ghotbi, Adam Ali; Bodholdt, Rasmus Poul

    2017-01-01

    Assessing myocardial perfusion using 82Rb-PET is emerging as a valuable clinical tool.1,2 The rapid decay (T½ = 76 s) allows for absolute quantification of both rest and stress perfusion within 30 minutes. In addition to evaluation of epicardial disease with perfusion defects, also evaluation...... of balanced coronary and small vessel disease is possible. For further evaluation of how 82Rb-PET can be used clinically, pre-clinical application of the method would be valuable. However, so far no data on the use of 82Rb-PET in small animals have been published nor has the use of 82Rb-PET, to the best...

  3. Blood perfusion in osteomyelitis studied with [15O]water PET in a juvenile porcine model

    DEFF Research Database (Denmark)

    Jødal, Lars; Nielsen, Ole L; Afzelius, Pia

    2017-01-01

    and not quantitative. Quantitative assessment of perfusion could aid in the selection of therapy. A non-invasive, quantitative way to study perfusion is dynamic [15O]water positron emission tomography (PET). We aim to demonstrate that the method can be used for measuring perfusion in OM lesions and hypothesize...... that perfusion will be less elevated in OM lesions than in soft tissue (ST) infection. The study comprised 11 juvenile pigs with haematogenous osteomyelitis induced by injection of Staphylococcus aureus into the right femoral artery 1 week before scanning (in one pig, 2 weeks). The pigs were dynamically PET...

  4. Ventilation-perfusion-lungscintigraphy using PET and {sup 68}Ga-labeled radiopharmaceuticals; Ventilations-Perfusions-Lungenszintigraphie mit der PET und {sup 68}Ga-markierten Radiopharmaka

    Energy Technology Data Exchange (ETDEWEB)

    Kotzerke, J. [Technische Univ. Dresden (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Technische Univ. Dresden (Germany). OncoRay - Zentrum fuer Innovationskompetenz Strahlenforschung in der Onkologie; Forschungszentrum Dresden-Rossendorf e.V. (FZR) (Germany). PET-Zentrum; Andreeff, M.; Wunderlich, G.; Zoephel, K. [Technische Univ. Dresden (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Wiggermann, P. [Technische Univ. Dresden (Germany). Inst. und Poliklinik fuer Diagnostische Radiologie

    2010-07-01

    Aim: Imaging of lung perfusion with positron emission tomography (PET) is already possible with {sup 68}Ga labeled denaturized albumin. The purpose of our study was to produce and test a {sup 68}Ga labeled aerosol (Galligas {sup registered}) for ventilation and {sup 68}Ga labeled albumin particles (microspheres) for perfusion imaging with PET. Patients, methods: Galligas was produced by simmering and burning generator eluted {sup 68}Ga solution (100 MBq/0.1ml) in an ordinary technegas generator. Fifteen patients with suspicion on pulmonary embolism underwent PET/CT (Biograph 16) after inhalation of Galligas and application of {sup 68}Ga labeled microspheres. A low dose CT was acquired for attenuation correction (AC). Images were reconstructed with and without AC. The inhaled activity was calculated compared to the activity injected. Results: Inhaled radioaerosol Galligas demonstrated typical distribution as known from {sup 99m}Tc-labeled technegas with homogeneous distribution in lung without hilar deposits. Attenuation corrected images resulted in artefacts in the lung base. Therefore, non-corrected images were used for making the results. Three out of fifteen patients showed a deficient perfusion whereas ventilation was normal corresponding to pulmonary embolism. Conclusion: Lung scintigraphy with PET is feasible. Galligas is simple to produce (analogously to technegas). {sup 68}Ga labeled microspheres are available. The method is applicable to daily routine and rendered clinically relevant informations. (orig.)

  5. Clinical use of quantitative cardiac perfusion PET : rationale, modalities and possible indications. Position paper of the Cardiovascular Committee of the European Association of Nuclear Medicine (EANM)

    NARCIS (Netherlands)

    Sciagra, Roberto; Passeri, Alessandro; Bucerius, Jan; Verberne, Hein J.; Slart, Riemer H. J. A.; Lindner, Oliver; Gimelli, Alessia; Hyafil, Fabien; Agostini, Denis; Uebleis, Christopher; Hacker, Marcus

    Until recently, PET was regarded as a luxurious way of performing myocardial perfusion scintigraphy, with excellent image quality and diagnostic capabilities that hardly justified the additional cost and procedural effort. Quantitative perfusion PET was considered a major improvement over standard

  6. Clinical use of quantitative cardiac perfusion PET: rationale, modalities and possible indications. Position paper of the Cardiovascular Committee of the European Association of Nuclear Medicine (EANM)

    NARCIS (Netherlands)

    Sciagrà, Roberto; Passeri, Alessandro; Bucerius, Jan; Verberne, Hein J.; Slart, Riemer H. J. A.; Lindner, Oliver; Gimelli, Alessia; Hyafil, Fabien; Agostini, Denis; Übleis, Christopher; Hacker, Marcus

    2016-01-01

    Until recently, PET was regarded as a luxurious way of performing myocardial perfusion scintigraphy, with excellent image quality and diagnostic capabilities that hardly justified the additional cost and procedural effort. Quantitative perfusion PET was considered a major improvement over standard

  7. MR perfusion/diffusion-weighted imaging of acute ischemia in an animal model with PET correlation

    International Nuclear Information System (INIS)

    Pickens, D.R.; Dawson, R.C.; Votaw, J.R.; Lorenz, C.H.; Holburn, G.E.; Price, R.R.

    1990-01-01

    This paper evaluates acute cerebral ischemia in an animal model with MR perfusion/diffusion-sensitive pulse sequences and to compare the results with PET regional cerebral blood flow (rCBF) measurements. An embolizing agent was injected into the proximal middle cerebral artery (MCA) of a dog, and this was followed by DSA. Next, the animal was imaged in a 1.5-T MR system with perfusion/diffusion-sensitive spin-echo pulse sequence. Then, PET imaging was performed with H 2 O 15 at corresponding levels of the brain

  8. PET imaging of cerebral perfusion and oxygen metabolism in stroke

    Energy Technology Data Exchange (ETDEWEB)

    Pointon, O.; Yasaka, M.; Berlangieri, S.U.; Newton, M.R.; Thomas, D.L.; Chan, C.G.; Egan, G.F.; Tochon-Danguy, H.J.; O``Keefe, G.; Donnan, G.A.; McKay, W.J. [Austin Hospital, Melbourne, VIC (Australia). Centre for PET and Depts of Nuclear Medicine and Neurology

    1998-03-01

    Full text: Stroke remains a devastating clinical event with few therapeutic options. In patients with acute stroke, we studied the cerebral perfusion and metabolic patterns with {sup 15}O-CO{sub 2} or H{sub 2}O and {sup 15}O-O{sub 2} positron emission tomography and correlated these findings to the clinical background. Forty three patients underwent 45 studies 0-23 days post-stroke (mean 7 days). Fifteen patients showed luxury perfusion (Group A), 10 had matched low perfusion and metabolism (B) and 3 showed mixed pattern including an area of misery perfusion (C). Seventeen showed no relevant abnormality (D) and there were no examples of isolated misery perfusion. Twelve of the 15 in Group A had either haemorrhagic transformation on CT, re-opening on angiography, or a cardioembolic mechanism. In contrast only 5/10 in Group B, 0/3 in Group C and 2/17 in Group D had these features. Although 7/10 in group B had moderate or large size infarcts on CT the incidence of haemorrhagic transformation was low (2/10) and significant carotid stenoses were more common in those studied (5/8) compared with the other groups. Misery perfusion was not seen beyond five days. Thus, luxury perfusion seems to be related to a cardio-embolic mechanism or reperfusion. Matched low perfusion and metabolism was associated with a low rate of haemorrhagic transformation despite a high incidence of moderate to large size infarcts. Misery perfusion is an early phenomenon in the evolution of ischaemic stroke.

  9. Evaluating the accuracy of perfusion/metabolism (SPET/PET) ratio in seizure localization

    Energy Technology Data Exchange (ETDEWEB)

    Buch, K.; Zubal, I.G. [Yale School of Medicine, Department of Diagnostic Radiology, New Haven, CT (United States); Blumenfeld, H.; Spencer, S.; Novotny, E. [Yale School of Medicine, Department of Neurology, P.O. Box 208018, New Haven, CT (United States)

    2008-03-15

    The uncoupling between brain perfusion and metabolism was evaluated as a potential tool for seizure localization by creating an interictal SPET divided by interictal PET functional ratio-image and by evaluating its sensitivity and specificity to areas subsequently surgically resected. The uncoupling between brain perfusion and metabolism was evaluated through the creation of a functional SPET/PET ratio-image relying on interictal single-photon emission computed tomography (SPET) and positron emission tomography (PET) scans in epilepsy patients. The uncoupling of these two physiological brain functions has been demonstrated to be a characteristic of epileptogenic tissue in temporal lobe epilepsy and could potentially serve as a diagnostic measure for localization of seizure onset areas in the brain. The accuracy of hemispheric localization, sensitivity, and specificity of perfusion to metabolism ratio-images were evaluated as compared to standard methods of PET reading. Interictal HMPAO-SPET and FDG-PET scans were obtained from 21 patients who then went on to remain seizure free for a minimum of 1 year post surgical resection. Using Statistical Parametric Mapping (SPM2), the SPET and PET scans were spatially registered and spatially normalized to a standard template (geometric warping). A functional image was created by calculating the ratio of perfusion to metabolism. Discrete areas of uncoupling in the ratio-images were selected, quantified, and compared to visually interpreted PET readings as well as the actual site of subsequent surgical resection. Localization was determined by comparing the hemispheric location of these areas to sites of surgical resection. Sensitivity and specificity of ratio-images and PET readings were calculated by dividing the brains into four sections per hemisphere. When compared to known sites of successful surgical resection, the pre-surgical visually interpreted PET readings had a correct hemispheric localization in 69.6% of cases

  10. Multimodal correlation of dynamic [18F]-AV-1451 perfusion PET and neuronal hypometabolism in [18F]-FDG PET.

    Science.gov (United States)

    Hammes, Jochen; Leuwer, Isabel; Bischof, Gérard N; Drzezga, Alexander; van Eimeren, Thilo

    2017-12-01

    Cerebral glucose metabolism measured with [18F]-FDG PET is a well established marker of neuronal dysfunction in neurodegeneration. The tau-protein tracer [18F]-AV-1451 PET is currently under evaluation and shows promising results. Here, we assess the feasibility of early perfusion imaging with AV-1451 as a substite for FDG PET in assessing neuronal injury. Twenty patients with suspected neurodegeneration underwent FDG and early phase AV-1451 PET imaging. Ten one-minute timeframes were acquired after application of 200 MBq AV-1451. FDG images were acquired on a different date according to clinical protocol. Early AV-1451 timeframes were coregistered to individual FDG-scans and spatially normalized. Voxel-wise intermodal correlations were calculated on within-subject level for every possible time window. The window with highest pooled correlation was considered optimal. Z-transformed deviation maps (ZMs) were created from both FDG and early AV-1451 images, comparing against FDG images of healthy controls. Regional patterns and extent of perfusion deficits were highly comparable to metabolic deficits. Best results were observed in a time window from 60 to 360 s (r = 0.86). Correlation strength ranged from r = 0.96 (subcortical gray matter) to 0.83 (frontal lobe) in regional analysis. ZMs of early AV-1451 and FDG images were highly similar. Perfusion imaging with AV-1451 is a valid biomarker for assessment of neuronal dysfunction in neurodegenerative diseases. Radiation exposure and complexity of the diagnostic workup could be reduced significantly by routine acquisition of early AV-1451 images, sparing additional FDG PET.

  11. Multimodal correlation of dynamic [18F]-AV-1451 perfusion PET and neuronal hypometabolism in [18F]-FDG PET

    International Nuclear Information System (INIS)

    Hammes, Jochen; Leuwer, Isabel; Bischof, Gerard N.; Drzezga, Alexander; Eimeren, Thilo van

    2017-01-01

    Cerebral glucose metabolism measured with [18F]-FDG PET is a well established marker of neuronal dysfunction in neurodegeneration. The tau-protein tracer [18F]-AV-1451 PET is currently under evaluation and shows promising results. Here, we assess the feasibility of early perfusion imaging with AV-1451 as a substite for FDG PET in assessing neuronal injury. Twenty patients with suspected neurodegeneration underwent FDG and early phase AV-1451 PET imaging. Ten one-minute timeframes were acquired after application of 200 MBq AV-1451. FDG images were acquired on a different date according to clinical protocol. Early AV-1451 timeframes were coregistered to individual FDG-scans and spatially normalized. Voxel-wise intermodal correlations were calculated on within-subject level for every possible time window. The window with highest pooled correlation was considered optimal. Z-transformed deviation maps (ZMs) were created from both FDG and early AV-1451 images, comparing against FDG images of healthy controls. Regional patterns and extent of perfusion deficits were highly comparable to metabolic deficits. Best results were observed in a time window from 60 to 360 s (r = 0.86). Correlation strength ranged from r = 0.96 (subcortical gray matter) to 0.83 (frontal lobe) in regional analysis. ZMs of early AV-1451 and FDG images were highly similar. Perfusion imaging with AV-1451 is a valid biomarker for assessment of neuronal dysfunction in neurodegenerative diseases. Radiation exposure and complexity of the diagnostic workup could be reduced significantly by routine acquisition of early AV-1451 images, sparing additional FDG PET. (orig.)

  12. Radiation dose to radiosensitive organs in PET/CT myocardial perfusion examination using versatile optical fibre

    Science.gov (United States)

    Salasiah, M.; Nordin, A. J.; Fathinul Fikri, A. S.; Hishar, H.; Tamchek, N.; Taiman, K.; Ahmad Bazli, A. K.; Abdul-Rashid, H. A.; Mahdiraji, G. A.; Mizanur, R.; Noor, Noramaliza M.

    2013-05-01

    Cardiac positron emission tomography (PET) provides a precise method in order to diagnose obstructive coronary artery disease (CAD), compared to single photon emission tomography (SPECT). PET is suitable for obese and patients who underwent pharmacologic stress procedures. It has the ability to evaluate multivessel coronary artery disease by recording changes in left ventricular function from rest to peak stress and quantifying myocardial perfusion (in mL/min/g of tissue). However, the radiation dose to the radiosensitive organs has become crucial issues in the Positron Emission Tomography/Computed Tomography(PET/CT) scanning procedure. The objective of this study was to estimate radiation dose to radiosensitive organs of patients who underwent PET/CT myocardial perfusion examination at Centre for Diagnostic Nuclear Imaging, Universiti Putra Malaysia in one month period using versatile optical fibres (Ge-B-doped Flat Fibre) and LiF (TLD-100 chips). All stress and rest paired myocardial perfusion PET/CT scans will be performed with the use of Rubidium-82 (82Rb). The optic fibres were loaded into plastic capsules and attached to patient's eyes, thyroid and breasts prior to the infusion of 82Rb, to accommodate the ten cases for the rest and stress PET scans. The results were compared with established thermoluminescence material, TLD-100 chips. The result shows that radiation dose given by TLD-100 and Germanium-Boron-doped Flat Fiber (Ge-B-doped Flat Fiber) for these five organs were comparable to each other where the p>0.05. For CT scans,thyroid received the highest dose compared to other organs. Meanwhile, for PET scans, breasts received the highest dose.

  13. Quantitative myocardial perfusion by O-15-water PET

    DEFF Research Database (Denmark)

    Thomassen, Anders; Petersen, Henrik; Johansen, Allan

    2015-01-01

    AIMS: Reporting of quantitative myocardial blood flow (MBF) is typically performed in standard coronary territories. However, coronary anatomy and myocardial vascular territories vary among individuals, and a coronary artery may erroneously be deemed stenosed or not if territorial demarcation...... disease (CAD). METHODS AND RESULTS: Forty-four patients with suspected CAD were included prospectively and underwent coronary CT-angiography and quantitative MBF assessment with O-15-water PET followed by invasive, quantitative coronary angiography, which served as reference. MBF was calculated...

  14. Enhancement of dynamic myocardial perfusion PET images based on low-rank plus sparse decomposition.

    Science.gov (United States)

    Lu, Lijun; Ma, Xiaomian; Mohy-Ud-Din, Hassan; Ma, Jianhua; Feng, Qianjin; Rahmim, Arman; Chen, Wufan

    2018-02-01

    The absolute quantification of dynamic myocardial perfusion (MP) PET imaging is challenged by the limited spatial resolution of individual frame images due to division of the data into shorter frames. This study aims to develop a method for restoration and enhancement of dynamic PET images. We propose that the image restoration model should be based on multiple constraints rather than a single constraint, given the fact that the image characteristic is hardly described by a single constraint alone. At the same time, it may be possible, but not optimal, to regularize the image with multiple constraints simultaneously. Fortunately, MP PET images can be decomposed into a superposition of background vs. dynamic components via low-rank plus sparse (L + S) decomposition. Thus, we propose an L + S decomposition based MP PET image restoration model and express it as a convex optimization problem. An iterative soft thresholding algorithm was developed to solve the problem. Using realistic dynamic 82 Rb MP PET scan data, we optimized and compared its performance with other restoration methods. The proposed method resulted in substantial visual as well as quantitative accuracy improvements in terms of noise versus bias performance, as demonstrated in extensive 82 Rb MP PET simulations. In particular, the myocardium defect in the MP PET images had improved visual as well as contrast versus noise tradeoff. The proposed algorithm was also applied on an 8-min clinical cardiac 82 Rb MP PET study performed on the GE Discovery PET/CT, and demonstrated improved quantitative accuracy (CNR and SNR) compared to other algorithms. The proposed method is effective for restoration and enhancement of dynamic PET images. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Residual Activity Correction in Quantitative Myocardial Perfusion N-13-Ammonia PET Imaging : A Study in Post-MI Patients

    NARCIS (Netherlands)

    Markousis-Mavrogenis, George; Juarez-Orozco, Luis Eduardo; Alexanderson, Erick

    2017-01-01

    Background/Introduction/Aim: Positron emission tomography (PET) is the gold standard for the quantification of myocardial blood flow (MBF). A standard PET scan is acquired in two phases (rest and pharmacological stress). N-13-ammonia is a perfusion radiotracer that may show residual activity, which

  16. Assessment of Cu-ETS as a PET radiopharmaceutical for evaluation of regional renal perfusion

    International Nuclear Information System (INIS)

    Green, Mark A.; Mathias, Carla J.; Willis, Lynn R.; Handa, Rajash K.; Lacy, Jeffrey L.; Miller, Michael A.; Hutchins, Gary D.

    2007-01-01

    The copper(II) complex of ethylglyoxal bis(thiosemicarbazone) (Cu-ETS) was evaluated as a positron emission tomography (PET) radiopharmaceutical for assessment of regional renal perfusion. Methods: The concordance of renal flow estimates obtained with 11- and 15-μm microspheres was confirmed in four immature farm pigs using co-injected 46 Sc- and 57 Co-microspheres administered into the left ventricle. With the use of both immature farm pigs (n=3) and mature Goettingen minipigs (n=6), regional renal radiocopper uptake following intravenous [ 64 Cu]Cu-ETS administration was compared to microsphere measurements of renal perfusion. The distribution and kinetics of [ 64 Cu]Cu-ETS were further studied by PET imaging of the kidneys. The rate of [ 64 Cu]Cu-ETS decomposition by blood was evaluated in vitro, employing octanol extraction to recover intact [ 64 Cu]Cu-ETS. Results: The co-injected 11- and 15-μm microspheres provided similar estimates of renal flow. A linear relationship was observed between the renal uptake of intravenous [ 64 Cu]Cu-ETS and regional renal perfusion measured using microspheres. [ 64 Cu]Cu-ETS provided high-quality PET kidney images demonstrating the expected count gradient from high-flow outer cortex to low-flow medulla. When incubated with pig blood in vitro at 37 o C, the [ 64 Cu]Cu-ETS radiopharmaceutical was observed to decompose with a half-time of 2.8 min. Conclusion: Cu-ETS appears suitable for use as a PET radiopharmaceutical for evaluation of regional renal perfusion, affording renal uptake of radiocopper that varies linearly with microsphere perfusion measurements. Quantification of renal perfusion (in ml min -1 g -1 ) with [ 60,61,62,64 Cu]Cu-ETS will require correcting the arterial input function for the fraction of blood radiocopper remaining present as the intact Cu-ETS radiopharmaceutical, since the Cu-ETS chelate has limited chemical stability in blood. Rapid octanol extraction of blood samples appears suitable as an approach

  17. Assessment of Cu-ETS as a PET radiopharmaceutical for evaluation of regional renal perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Green, Mark A. [Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907 (United States)]. E-mail: magreen@purdue.edu; Mathias, Carla J. [Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907 (United States); Willis, Lynn R. [Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Handa, Rajash K. [Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Lacy, Jeffrey L. [Proportional Technologies, Inc., Houston, TX 77054 (United States); Miller, Michael A. [Department of Radiology and the Indiana Center of Excellence in Biomedical Imaging, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Hutchins, Gary D. [Department of Radiology and the Indiana Center of Excellence in Biomedical Imaging, Indiana University School of Medicine, Indianapolis, IN 46202 (United States)

    2007-04-15

    The copper(II) complex of ethylglyoxal bis(thiosemicarbazone) (Cu-ETS) was evaluated as a positron emission tomography (PET) radiopharmaceutical for assessment of regional renal perfusion. Methods: The concordance of renal flow estimates obtained with 11- and 15-{mu}m microspheres was confirmed in four immature farm pigs using co-injected {sup 46}Sc- and {sup 57}Co-microspheres administered into the left ventricle. With the use of both immature farm pigs (n=3) and mature Goettingen minipigs (n=6), regional renal radiocopper uptake following intravenous [{sup 64}Cu]Cu-ETS administration was compared to microsphere measurements of renal perfusion. The distribution and kinetics of [{sup 64}Cu]Cu-ETS were further studied by PET imaging of the kidneys. The rate of [{sup 64}Cu]Cu-ETS decomposition by blood was evaluated in vitro, employing octanol extraction to recover intact [{sup 64}Cu]Cu-ETS. Results: The co-injected 11- and 15-{mu}m microspheres provided similar estimates of renal flow. A linear relationship was observed between the renal uptake of intravenous [{sup 64}Cu]Cu-ETS and regional renal perfusion measured using microspheres. [{sup 64}Cu]Cu-ETS provided high-quality PET kidney images demonstrating the expected count gradient from high-flow outer cortex to low-flow medulla. When incubated with pig blood in vitro at 37{sup o}C, the [{sup 64}Cu]Cu-ETS radiopharmaceutical was observed to decompose with a half-time of 2.8 min. Conclusion: Cu-ETS appears suitable for use as a PET radiopharmaceutical for evaluation of regional renal perfusion, affording renal uptake of radiocopper that varies linearly with microsphere perfusion measurements. Quantification of renal perfusion (in ml min{sup -1} g{sup -1}) with [{sup 60,61,62,64}Cu]Cu-ETS will require correcting the arterial input function for the fraction of blood radiocopper remaining present as the intact Cu-ETS radiopharmaceutical, since the Cu-ETS chelate has limited chemical stability in blood. Rapid octanol

  18. Noninvasive assessment of coronary collaterals in man by PET perfusion imaging

    International Nuclear Information System (INIS)

    Demer, L.L.; Gould, K.L.; Goldstein, R.A.; Kirkeeide, R.L.

    1990-01-01

    At present, coronary collateralization cannot be identified or assessed noninvasively in patients. In animal studies, coronary collaterals are associated with coronary steal, defined as a regional fall in perfusion during coronary arteriolar vasodilation. To determine the effect of coronary arteriolar vasodilation on collateral bed perfusion in man, myocardial perfusion imaging was performed before and after pharmacologic coronary vasodilation in patients with coronary artery disease (CAD). Regional myocardial activity of 82 Rb or 13 N ammonia was measured by positron emission tomography (PET) at rest and with intravenous dipyridamole/handgrip stress in 28 patients with angiographic collaterals and in 25 control patients with similar CAD severity by quantitative arteriography. Regional myocardial activity decreased after dipyridamole, indicating coronary steal, in 25 of 28 patients with angiographic collaterals and in only 4 of 25 control patients without angiographic collaterals. These findings suggest that developed collaterals are associated with myocardial steal in patients with CAD, allowing potential use of PET for non-invasive identification of coronary collateralization

  19. Brain perfusion SPECT and FDG PET findings in a patient with ballism associated with hyperthyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sang Kyun; Kim, Sang Jin [Pusan Paik Hospital, Pusan (Korea, Republic of)

    2007-07-01

    Ballism is a very rare presentation in association with hyperthyroidism. We describe a 22-year-old lady with episodes of recurrent ballism and hyperthyroidism. A 22-year-old lady was admitted to Neurology department because of sudden development of vigorous involuntary movement and dysarthria. She was diagnosed as hyperthyroidism at the age 12 and treated irregularly. She arrived at the emergency room because of sudden onset of involuntary movement. Computed tomography (CT) scan and Magnetic Resonance Imaging (MRI) of brain was normal. Serum levels of thyroid hormone were increased (Free T4 3.15 ng/dl; normal range 0.93-1.71 ng/dl), whereas thyroid-stimulating hormone (TSH) was undetectable. The thyroid gland was diffusely enlarged and exophthalmos was found. She had been given antithyroid medication from local clinic but medicated irregularly. Technetium thyroid scan reveals diffusely enlarged thyroid with increased radioactivity. Radioiodine uptake in 24 hours was 71 %. Brain perfusion SPECT using Tc-99m ECD reveals asymmetrical perfusion pattern in basal ganglia. Brain PET using F-18 FDG reveals increased metabolism at both caudate nucleus and putamen. She was treated with radioiodine and involuntary movement was improved. There is only few report on ballism associated with hyperthyroidism and no report on functional brain imaging. Brain perfusion SPECT and FDG PET may give useful information about functional status of brain in patients with ballism associated with hyperthyroidism in case of normal anatomical finding on CT/MRI.

  20. Brain perfusion SPECT and FDG PET findings in a patient with ballism associated with hyperthyroidism

    International Nuclear Information System (INIS)

    Bae, Sang Kyun; Kim, Sang Jin

    2007-01-01

    Ballism is a very rare presentation in association with hyperthyroidism. We describe a 22-year-old lady with episodes of recurrent ballism and hyperthyroidism. A 22-year-old lady was admitted to Neurology department because of sudden development of vigorous involuntary movement and dysarthria. She was diagnosed as hyperthyroidism at the age 12 and treated irregularly. She arrived at the emergency room because of sudden onset of involuntary movement. Computed tomography (CT) scan and Magnetic Resonance Imaging (MRI) of brain was normal. Serum levels of thyroid hormone were increased (Free T4 3.15 ng/dl; normal range 0.93-1.71 ng/dl), whereas thyroid-stimulating hormone (TSH) was undetectable. The thyroid gland was diffusely enlarged and exophthalmos was found. She had been given antithyroid medication from local clinic but medicated irregularly. Technetium thyroid scan reveals diffusely enlarged thyroid with increased radioactivity. Radioiodine uptake in 24 hours was 71 %. Brain perfusion SPECT using Tc-99m ECD reveals asymmetrical perfusion pattern in basal ganglia. Brain PET using F-18 FDG reveals increased metabolism at both caudate nucleus and putamen. She was treated with radioiodine and involuntary movement was improved. There is only few report on ballism associated with hyperthyroidism and no report on functional brain imaging. Brain perfusion SPECT and FDG PET may give useful information about functional status of brain in patients with ballism associated with hyperthyroidism in case of normal anatomical finding on CT/MRI

  1. Biodistribution and stability studies of [18F]Fluoroethylrhodamine B, a potential PET myocardial perfusion agent

    International Nuclear Information System (INIS)

    Gottumukkala, Vijay; Heinrich, Tobias K.; Baker, Amanda; Dunning, Patricia; Fahey, Frederic H.; Treves, S. Ted; Packard, Alan B.

    2010-01-01

    Introduction: Fluorine-18-labeled rhodamine B was developed as a potential positron emission tomography (PET) tracer for the evaluation of myocardial perfusion, but preliminary studies in mice showed no accumulation in the heart suggesting that it was rapidly hydrolyzed in vivo in mice. A study was therefore undertaken to further evaluate this hypothesis. Methods: [ 18 F]Fluoroethylrhodamine B was equilibrated for 2 h at 37 deg. C in human, rat and mouse serum and in phosphate-buffered saline. Samples were removed periodically and assayed by high-performance liquid chromatography. Based on the results of the stability study, microPET imaging and a biodistribution study were carried out in rats. Results: In vitro stability studies demonstrated that [ 18 F]fluoroethylrhodamine B much more stable in rat and human sera than in mouse serum. After 2 h, the compound was >80% intact in rat serum but 18 F-labeled rhodamines should accumulate in the heart. Conclusions: [ 18 F]Fluoroethylrhodamine B is more stable in rat and human sera than it is in mouse serum. This improved stability is demonstrated by the high uptake of the tracer in the rat heart in comparison to the absence of visible uptake in the mouse heart. These observations suggest that 18 F-labeled rhodamines are promising candidates for more extensive evaluation as PET tracers for the evaluation of myocardial perfusion.

  2. Optimization of Rb-82 PET acquisition and reconstruction protocols for myocardial perfusion defect detection

    Science.gov (United States)

    Tang, Jing; Rahmim, Arman; Lautamäki, Riikka; Lodge, Martin A.; Bengel, Frank M.; Tsui, Benjamin M. W.

    2009-05-01

    The purpose of this study is to optimize the dynamic Rb-82 cardiac PET acquisition and reconstruction protocols for maximum myocardial perfusion defect detection using realistic simulation data and task-based evaluation. Time activity curves (TACs) of different organs under both rest and stress conditions were extracted from dynamic Rb-82 PET images of five normal patients. Combined SimSET-GATE Monte Carlo simulation was used to generate nearly noise-free cardiac PET data from a time series of 3D NCAT phantoms with organ activities modeling different pre-scan delay times (PDTs) and total acquisition times (TATs). Poisson noise was added to the nearly noise-free projections and the OS-EM algorithm was applied to generate noisy reconstructed images. The channelized Hotelling observer (CHO) with 32× 32 spatial templates corresponding to four octave-wide frequency channels was used to evaluate the images. The area under the ROC curve (AUC) was calculated from the CHO rating data as an index for image quality in terms of myocardial perfusion defect detection. The 0.5 cycle cm-1 Butterworth post-filtering on OS-EM (with 21 subsets) reconstructed images generates the highest AUC values while those from iteration numbers 1 to 4 do not show different AUC values. The optimized PDTs for both rest and stress conditions are found to be close to the cross points of the left ventricular chamber and myocardium TACs, which may promote an individualized PDT for patient data processing and image reconstruction. Shortening the TATs for <~3 min from the clinically employed acquisition time does not affect the myocardial perfusion defect detection significantly for both rest and stress studies.

  3. Quantitative myocardial perfusion PET parametric imaging at the voxel-level

    International Nuclear Information System (INIS)

    Mohy-ud-Din, Hassan; Rahmim, Arman; Lodge, Martin A

    2015-01-01

    Quantitative myocardial perfusion (MP) PET has the potential to enhance detection of early stages of atherosclerosis or microvascular dysfunction, characterization of flow-limiting effects of coronary artery disease (CAD), and identification of balanced reduction of flow due to multivessel stenosis. We aim to enable quantitative MP-PET at the individual voxel level, which has the potential to allow enhanced visualization and quantification of myocardial blood flow (MBF) and flow reserve (MFR) as computed from uptake parametric images. This framework is especially challenging for the 82 Rb radiotracer. The short half-life enables fast serial imaging and high patient throughput; yet, the acquired dynamic PET images suffer from high noise-levels introducing large variability in uptake parametric images and, therefore, in the estimates of MBF and MFR. Robust estimation requires substantial post-smoothing of noisy data, degrading valuable functional information of physiological and pathological importance. We present a feasible and robust approach to generate parametric images at the voxel-level that substantially reduces noise without significant loss of spatial resolution. The proposed methodology, denoted physiological clustering, makes use of the functional similarity of voxels to penalize deviation of voxel kinetics from physiological partners. The results were validated using extensive simulations (with transmural and non-transmural perfusion defects) and clinical studies. Compared to post-smoothing, physiological clustering depicted enhanced quantitative noise versus bias performance as well as superior recovery of perfusion defects (as quantified by CNR) with minimal increase in bias. Overall, parametric images obtained from the proposed methodology were robust in the presence of high-noise levels as manifested in the voxel time-activity-curves. (paper)

  4. Diagnostic value of rest and stress gated 82Rb PET myocardial perfusion imaging using quantitative software

    International Nuclear Information System (INIS)

    Shi Hongcheng; Gu Yusen; Liu Wenguan; Zhu Weimin; Halkar, R.K.; Santana, C.A.; Feng Yusheng

    2008-01-01

    Objective: Gated myocardial perfusion imaging (MPI) is regularly performed using SPECT. More recently, gated 82 Rb MPI has been used to assess left ventricular myocardial perfusion and function with new generation PET scanners. The objective of this study was to evaluate the value of rest and stress gated 82 Rb PET myocardial perfusion imaging and to determine whether the quantitative technique in- creased the confidence level of the interpreters. Methods: Thirty-two patients underwent rest and adenosine stress gated 82 Pb PET MPI. Emory Cardiac Toolbox quantitative software was used for processing and inter-predation. Left ventricular ejection fraction (LVEF), end-diastolic, end-systolic and transient ischemia dilation ratio were automatically generated. Three interpreters (nuclear medicine doctors) independently reviewed the studies. Visual scoring (1-5 scales: excellent, good, unsure, poor, uninterpretable) was used to assess the overall quality of the gated images and the added confidence level of interpretation. Visual assessment of the LVEF was compared to the automatically generated LVEF. Comparison between the visual assessment and software generated was graded on a 1- 5 scales (helpful, probably helpful, unsure, probably not helpful, definitely not helpful). The analysed items were divided into two groups (favorable group and negative group). The percentage and 95% confidence intervals of each group were calculated. Results: A total of 192 gated studies were evaluated (64 gated x 3 interpreters ). The overall quality of the gated images was good [excellent 40.1% (77/192), good 43.2% (83/192), unsure 3.1% (6/192), poor 13.6% (26/192), uninterpretable 0]. The 95% confidence intervals of good and excellent quality range from 78.1% to 88.6%. The interpreter's agreed with the automated LVEF on 85.4% of the gated images [agree 76.6% (147/192), probably agree 8.8% (17/192), unsure 3.1% (6/192), probably disagree 8.8% (17/192), disagree 2.6% (5/192)]. And its 95

  5. Automatic delineation of functional lung volumes with 68Ga-ventilation/perfusion PET/CT.

    Science.gov (United States)

    Le Roux, Pierre-Yves; Siva, Shankar; Callahan, Jason; Claudic, Yannis; Bourhis, David; Steinfort, Daniel P; Hicks, Rodney J; Hofman, Michael S

    2017-10-10

    Functional volumes computed from 68 Ga-ventilation/perfusion (V/Q) PET/CT, which we have shown to correlate with pulmonary function test parameters (PFTs), have potential diagnostic utility in a variety of clinical applications, including radiotherapy planning. An automatic segmentation method would facilitate delineation of such volumes. The aim of this study was to develop an automated threshold-based approach to delineate functional volumes that best correlates with manual delineation. Thirty lung cancer patients undergoing both V/Q PET/CT and PFTs were analyzed. Images were acquired following inhalation of Galligas and, subsequently, intravenous administration of 68 Ga-macroaggreted-albumin (MAA). Using visually defined manual contours as the reference standard, various cutoff values, expressed as a percentage of the maximal pixel value, were applied. The average volume difference and Dice similarity coefficient (DSC) were calculated, measuring the similarity of the automatic segmentation and the reference standard. Pearson's correlation was also calculated to compare automated volumes with manual volumes, and automated volumes optimized to PFT indices. For ventilation volumes, mean volume difference was lowest (- 0.4%) using a 15%max threshold with Pearson's coefficient of 0.71. Applying this cutoff, median DSC was 0.93 (0.87-0.95). Nevertheless, limits of agreement in volume differences were large (- 31.0 and 30.2%) with differences ranging from - 40.4 to + 33.0%. For perfusion volumes, mean volume difference was lowest and Pearson's coefficient was highest using a 15%max threshold (3.3% and 0.81, respectively). Applying this cutoff, median DSC was 0.93 (0.88-0.93). Nevertheless, limits of agreement were again large (- 21.1 and 27.8%) with volume differences ranging from - 18.6 to + 35.5%. Using the 15%max threshold, moderate correlation was demonstrated with FEV1/FVC (r = 0.48 and r = 0.46 for ventilation and perfusion images, respectively

  6. Radiation exposure for medical staff performing quantitative coronary perfusion PET with 13N-ammonia

    DEFF Research Database (Denmark)

    Kristoffersen, Ulrik Sloth; Borgwardt, Henrik Gutte; Skovgaard, Dorthe Charlotte

    2009-01-01

    with dipyridamole) and eight examinations consisted of three PET scans (additionally a scan after cold pressor testing). The two nuclear technologists and the physician attending the examinations were equipped with an electronic dosemeter over the chest and thermoluminescent dosimetry chips on the right index...... finger and wrist. RESULTS: The highest mean equivalent dose per examination for a staff member was 453 microSv (417-490 microSv) to the right index finger, 138 microSv (127-149 microSv) to the right wrist and 13 +/- 0.8 microSv to the chest. CONCLUSIONS: Myocardial perfusion PET with (13)N......-ammonia exposes the staff to radiation doses that are comparable to doses from (18)F-fluoro-deoxy-glucose scans and the annual doses are well within the recommended upper limits for radiation workers....

  7. Quantitative myocardial perfusion PET combined with coronary anatomy derived from CT angiography. Validation of a new fusion and visualisation software

    International Nuclear Information System (INIS)

    Fricke, Harald; Weise, Reiner; Burchert, Wolfgang; Fricke, Eva; Elsner, Andreas; Bolte, Matthias; Domik, Gitta; Hoff, Joerg van den

    2009-01-01

    Aim: Dynamic perfusion PET offers a clinical relevant advantage over myocardial perfusion scintigraphy due to its ability to measure myocardial blood flow quantitatively. This leads to an improved detection of multivessel disease and the possibility to assess not only the culprit lesion but lower grade stenoses as well. For appropriate revascularization, perfusion defects must be matched to coronary lesions. It has been shown that image fusion of morphological and functional images is superior to side-by-side analysis. Still, software for quantitative perfusion PET combined with CT angiography is rare. In this paper we present a new software tool for image fusion and visualization of quantitative perfusion PET and coronary morphology derived from CT angiography. Methods: In our software, a PET uptake image is used for manual co-registration. Co-registration results are then applied to the functional data derived from compartment modelling. To evaluate the reproducibility of the manual co-registration, we calculated the deviation between a series of manual co-registrations performed on nine pairs of unregistered PET and CT datasets by five trained participants. Two dimensional transfer functions were used to highlight the coronary arteries from the CT study in the combined data sets. Results: The average Euclidian distances for three references points were between 3.7 and 4.1 mm. The maximum distance was 10.6 mm. By the use of the two dimensional transfer functions, coronary anatomy could be easily visualised either by user-interaction or automatically by use of neuronal networks. Conclusions: With this approach it is possible to combine quantitative perfusion PET with coronary anatomy derived from CT angiography. Our first experiences indicate that manual image fusion with our tool is reproducible and that visualisation of the combined datasets is achieved within short time. (orig.)

  8. PET imaging of cerebral perfusion and oxygen consumption in acute ischemic stroke: Relation to outcome

    International Nuclear Information System (INIS)

    Marchal, G.; Serrati, C.; Rioux, P.; Petit-Taboue, M.C.; Viader, F.; Sayette, V. de la; Doze, F. le; Lonchon, P; Derlon, J.M.; Orgogozo, J.M.; Baron, J.C.

    1993-01-01

    The authors used positron emission tomography (PET) to assess the relation between combined imaging of cerebral blood flow and oxygen consumption 5-18 h after first middle cerebral artery (MCA) stroke and neurological outcome at 2 months. All 18 patients could be classified into three visually defined PET patterns of perfusion and oxygen consumption changes. Pattern 1 suggested extensive irreversible damage and was consistently associated with poor outcome. Pattern 2 suggested continuing ischemia and was associated with variable outcome. Pattern 3 with hyperperfusion and little or no metabolic alteration, was associated with excellent recovery, which suggests that early reperfusion is beneficial. This relation between PET and outcome was highly significant. The results suggest that within 5-18 h of stroke onset, PET is a good predictor of outcome in patterns 1 and 3, for which therapy seems limited. The absence of predictive value for pattern 2 suggests that it is due to a reversible ischemic state that is possibly amenable to therapy. These findings may have important implications for acute MCA stroke management and for patients' selection for therapeutic trials

  9. Simplified quantitative determination of cerebral perfusion reserve with H215O PET and acetazolamide

    International Nuclear Information System (INIS)

    Arigoni, M.; Kneifel, S.; Burger, C.; Buck, A.; Fandino, J.; Khan, N.

    2000-01-01

    The measurement of regional cerebral blood from (rCBF) and perfusion reserve (PR) with H 2 15 O positron emission tomography (PET) and acetazolamide challenge is of importance in evaluating patients with cerebrovascular disease and is thought to be useful in selecting patients for possible vascular surgery. Full quantitative assessment of rCBF with PET requires arterial blood sampling, which is inconvenient in a clinical setting. In this work, we present a simple non-invasive method with which to quantitatively evaluate PR in one PET session lasting no more than 30 min. In ten patients with cerebrovascular disease, rCBF was measured with H 2 15 O PET under the baseline condition and after administration of 1 g acetazolamide using a standard technique involving arterial blood sampling. The activity accumulated over 60 s was normalized to injected activity per kilogram body weight (nAA) and compared with rCBF in eight different brain regions. A high linear correlation was found for PR based on nAA (PR nAA ) and rCBF (PR rCBF ) (PR nAA =0.843 PR rCBF + 0.092, r=0.83, Pearson's correlation coefficient). Bland-Altman analyses further confirmed that PR nAA reflects PR in a quantitative manner. These results demonstrate that the method based on normalized counts allows the quantitative assessment of PR without blood sampling. (orig.)

  10. Diagnostic and clinical benefit of combined coronary calcium and perfusion assessment in patients undergoing PET/CT myocardial perfusion stress imaging.

    Science.gov (United States)

    Bybee, Kevin A; Lee, John; Markiewicz, Richard; Longmore, Ryan; McGhie, A Iain; O'Keefe, James H; Hsu, Bai-Ling; Kennedy, Kevin; Thompson, Randall C; Bateman, Timothy M

    2010-04-01

    A limitation of stress myocardial perfusion imaging (MPI) is the inability to detect non-obstructive coronary artery disease (CAD). One advantage of MPI with a hybrid CT device is the ability to obtain same-setting measurement of the coronary artery calcium score (CACS). Utilizing our single-center nuclear database, we identified 760 consecutive patients with: (1) no CAD history; (2) a normal clinically indicated Rb-82 PET/CT stress perfusion study; and (3) a same-setting CAC scan. 487 of 760 patients (64.1%) had subclinical CAD based on an abnormal CACS. Of those with CAC, the CACS was > or =100, > or =400, and > or =1000 in 47.0%, 22.4%, and 8.4% of patients, respectively. Less than half of the patients with CAC were receiving aspirin or statin medications prior to PET/CT imaging. Patients with CAC were more likely to be initiated or optimized on proven medical therapy for CAD immediately following PET/CT MPI compared to those without CAC. Subclinical CAD is common in patients without known CAD and normal myocardial perfusion assessed by hybrid PET/CT imaging. Identification of CAC influences subsequent physician prescribing patterns such that those with CAC are more likely to be treated with proven medical therapy for the treatment of CAD.

  11. Global low perfusion and latent ischemic lesions desclosed by PET and MRI in polycythermia hypertonica

    International Nuclear Information System (INIS)

    Harada, Kiyoshi; Kameyama, Masakuni; Akiguchi, Ichiro; Fukuyama, Hidenao; Nabatame, Hidehiko

    1987-01-01

    Polycythemia hypertonica was first reported by Geisboeck in 1905 (Geisboeck's syndrome), which has been well known to accompany a high risk for cerebrovascular disorders, and relatively poor prognosis. We performed PET and MRI study on two patients with Geisboeck's syndrome. In both cases, PET study revealed that there were no focal abnormalities in cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2), but global CBF and CMRO2 decreased to low levels. On MRI study, we also found multiple small ischemic lesions in the deep structures in the cerebral hemisphere as well as brain stem, which were considered to be coincided with the perfusion territories of perforating arteries. Many of the lesions revealed by MRI were not apparent on X-ray CT scan, and were asymptomatic clinically. We consider that global low perfusion and many small latent ischemic lesions are characteristic for Geisboeck's syndrome. Therefore, it is necessary to control high hematocrit values and hypertension from an early stage of the patients with Geisboeck's syndrome. (author)

  12. Global low perfusion and latent ischemic lesions desclosed by PET and MRI in polycythemia hypertonica

    Energy Technology Data Exchange (ETDEWEB)

    Harada, K.; Kameyama, M.; Akiguchi, I.; Fukuyama, H.; Nabatame, H.

    1987-04-01

    Polycythemia hypertonica, first reported by Geisboeck in 1905 (Geisboeck's syndrome), has been known for an accompanying high risk of cerebrovascular disorders and relatively poor prognosis. We performed PET and MRI study on two patients with Geisboeck's syndrome. In both cases, PET study revealed that there were no focal abnormalities in cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO/sub 2/), but global CBF and CMRO/sub 2/ decreased to low levels. On MRI study, we also found multiple small ischemic lesions in the deep structures in the cerebral hemisphere as well as brain stem, which were considered to be coincided with the perfusion territories of perforating arteries. Many of the lesions revealed by MRI were not apparent on X-ray CT scan, and were asymptomatic clinically. We consider that global low perfusion and many small latent ischemic lesions are characteristic of Geisboeck's syndrome. Therefore, it is necessary to control high hematocrit values and hypertension from an early stage of the patients with Geisboeck's syndrome.

  13. Direct parametric reconstruction in dynamic PET myocardial perfusion imaging: in vivo studies

    Science.gov (United States)

    Petibon, Yoann; Rakvongthai, Yothin; El Fakhri, Georges; Ouyang, Jinsong

    2017-05-01

    Dynamic PET myocardial perfusion imaging (MPI) used in conjunction with tracer kinetic modeling enables the quantification of absolute myocardial blood flow (MBF). However, MBF maps computed using the traditional indirect method (i.e. post-reconstruction voxel-wise fitting of kinetic model to PET time-activity-curves-TACs) suffer from poor signal-to-noise ratio (SNR). Direct reconstruction of kinetic parameters from raw PET projection data has been shown to offer parametric images with higher SNR compared to the indirect method. The aim of this study was to extend and evaluate the performance of a direct parametric reconstruction method using in vivo dynamic PET MPI data for the purpose of quantifying MBF. Dynamic PET MPI studies were performed on two healthy pigs using a Siemens Biograph mMR scanner. List-mode PET data for each animal were acquired following a bolus injection of ~7-8 mCi of 18F-flurpiridaz, a myocardial perfusion agent. Fully-3D dynamic PET sinograms were obtained by sorting the coincidence events into 16 temporal frames covering ~5 min after radiotracer administration. Additionally, eight independent noise realizations of both scans—each containing 1/8th of the total number of events—were generated from the original list-mode data. Dynamic sinograms were then used to compute parametric maps using the conventional indirect method and the proposed direct method. For both methods, a one-tissue compartment model accounting for spillover from the left and right ventricle blood-pools was used to describe the kinetics of 18F-flurpiridaz. An image-derived arterial input function obtained from a TAC taken in the left ventricle cavity was used for tracer kinetic analysis. For the indirect method, frame-by-frame images were estimated using two fully-3D reconstruction techniques: the standard ordered subset expectation maximization (OSEM) reconstruction algorithm on one side, and the one-step late maximum a posteriori (OSL-MAP) algorithm on the other

  14. Direct parametric reconstruction in dynamic PET myocardial perfusion imaging: in-vivo studies

    Science.gov (United States)

    Petibon, Yoann; Rakvongthai, Yothin; Fakhri, Georges El; Ouyang, Jinsong

    2017-01-01

    Dynamic PET myocardial perfusion imaging (MPI) used in conjunction with tracer kinetic modeling enables the quantification of absolute myocardial blood flow (MBF). However, MBF maps computed using the traditional indirect method (i.e. post-reconstruction voxel-wise fitting of kinetic model to PET time-activity-curves -TACs) suffer from poor signal-to-noise ratio (SNR). Direct reconstruction of kinetic parameters from raw PET projection data has been shown to offer parametric images with higher SNR compared to the indirect method. The aim of this study was to extend and evaluate the performance of a direct parametric reconstruction method using in-vivo dynamic PET MPI data for the purpose of quantifying MBF. Dynamic PET MPI studies were performed on two healthy pigs using a Siemens Biograph mMR scanner. List-mode PET data for each animal were acquired following a bolus injection of ~7-8 mCi of 18F-flurpiridaz, a myocardial perfusion agent. Fully-3D dynamic PET sinograms were obtained by sorting the coincidence events into 16 temporal frames covering ~5 min after radiotracer administration. Additionally, eight independent noise realizations of both scans - each containing 1/8th of the total number of events - were generated from the original list-mode data. Dynamic sinograms were then used to compute parametric maps using the conventional indirect method and the proposed direct method. For both methods, a one-tissue compartment model accounting for spillover from the left and right ventricle blood-pools was used to describe the kinetics of 18F-flurpiridaz. An image-derived arterial input function obtained from a TAC taken in the left ventricle cavity was used for tracer kinetic analysis. For the indirect method, frame-by-frame images were estimated using two fully-3D reconstruction techniques: the standard Ordered Subset Expectation Maximization (OSEM) reconstruction algorithm on one side, and the One-Step Late Maximum a Posteriori (OSL-MAP) algorithm on the other

  15. Synthesis of fluorine-18 labeled rhodamine B: A potential PET myocardial perfusion imaging agent

    International Nuclear Information System (INIS)

    Heinrich, Tobias K.; Gottumukkala, Vijay; Snay, Erin; Dunning, Patricia; Fahey, Frederic H.; Ted Treves, S.; Packard, Alan B.

    2010-01-01

    There is considerable interest in developing an 18 F-labeled PET myocardial perfusion agent. Rhodamine dyes share several properties with 99m Tc-MIBI, the most commonly used single-photon myocardial perfusion agent, suggesting that an 18 F-labeled rhodamine dye might prove useful for this application. In addition to being lipophilic cations, like 99m Tc-MIBI, rhodamine dyes are known to accumulate in the myocardium and are substrates for Pgp, the protein implicated in MDR1 multidrug resistance. As the first step in determining whether 18 F-labeled rhodamines might be useful as myocardial perfusion agents for PET, our objective was to develop synthetic methods for preparing the 18 F-labeled compounds so that they could be evaluated in vivo. Rhodamine B was chosen as the prototype compound for development of the synthesis because the ethyl substituents on the amine moieties of rhodamine B protect them from side reactions, thus eliminating the need to include (and subsequently remove) protecting groups. The 2'-[ 18 F]fluoroethyl ester of rhodamine B was synthesized by heating rhodamine B lactone with [ 18 F]fluoroethyltosylate in acetonitrile at 165 deg. C for 30 min using [ 18 F]fluoroethyl tosylate, which was prepared by the reaction of ethyleneglycol ditosylate with Kryptofix 2.2.2, K 2 CO 3 , and [ 18 F]NaF in acetonitrile for 10 min at 90 deg. C. The product was purified by semi-preparative HPLC to produce the 2'-[ 18 F]fluoroethylester in >97% radiochemical purity with a specific activity of 1.3 GBq/μmol, an isolated decay corrected yield of 35%, and a total synthesis time of 90 min.

  16. Synthesis of fluorine-18 labeled rhodamine B: A potential PET myocardial perfusion imaging agent

    Science.gov (United States)

    Heinrich, Tobias K.; Gottumukkala, Vijay; Snay, Erin; Dunning, Patricia; Fahey, Frederic H; Treves, S. Ted; Packard, Alan B.

    2009-01-01

    There is considerable interest in developing an 18F-labeled PET myocardial perfusion agent. Rhodamine dyes share several properties with 99mTc-MIBI, the most commonly used single-photon myocardial perfusion agent, suggesting that an 18F-labeled rhodamine dye might prove useful for this application. In addition to being lipophilic cations, like 99mTc-MIBI, rhodamine dyes are known to accumulate in the myocardium and are substrates for Pgp, the protein implicated in MDR1 multidrug resistance. As the first step in determining whether 18F-labeled rhodamines might be useful as myocardial perfusion agents for PET, our objective was to develop synthetic methods for preparing the 18F-labeled compounds so that they could be evaluated in vivo. Rhodamine B was chosen as the prototype compound for development of the synthesis because the ethyl substituents on the amine moieties of rhodamine B protect them from side reactions, thus eliminating the need to include (and subsequently remove) protecting groups. The 2′-[18F]fluoroethyl ester of rhodamine B was synthesized by heating rhodamine B lactone with [18F]fluoroethyltosylate in acetonitrile at 165°C for 30 min.using [18F]fluoroethyl tosylate, which was prepared by the reaction of ethyleneglycol ditosylate with Kryptofix 2.2.2, K2CO3, and [18F]NaF in acetonitrile for 10 min. at 90°C. The product was purified by semi-preparative HPLC to produce the 2′-[18F]-fluoroethylester in >97% radiochemical purity with a specific activity of 1.3 GBq/μmol, an isolated decay corrected yield of 35%, and a total synthesis time of 90 min. PMID:19783150

  17. Synthesis of fluorine-18 labeled rhodamine B: A potential PET myocardial perfusion imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, Tobias K.; Gottumukkala, Vijay [Division of Nuclear Medicine, Department of Radiology, Children' s Hospital Boston, 300 Longwood Ave., Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Snay, Erin; Dunning, Patricia [Division of Nuclear Medicine, Department of Radiology, Children' s Hospital Boston, 300 Longwood Ave., Boston, MA 02115 (United States); Fahey, Frederic H.; Ted Treves, S. [Division of Nuclear Medicine, Department of Radiology, Children' s Hospital Boston, 300 Longwood Ave., Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Packard, Alan B. [Division of Nuclear Medicine, Department of Radiology, Children' s Hospital Boston, 300 Longwood Ave., Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States)], E-mail: alan.packard@childrens.harvard.edu

    2010-01-15

    There is considerable interest in developing an {sup 18}F-labeled PET myocardial perfusion agent. Rhodamine dyes share several properties with {sup 99m}Tc-MIBI, the most commonly used single-photon myocardial perfusion agent, suggesting that an {sup 18}F-labeled rhodamine dye might prove useful for this application. In addition to being lipophilic cations, like {sup 99m}Tc-MIBI, rhodamine dyes are known to accumulate in the myocardium and are substrates for Pgp, the protein implicated in MDR1 multidrug resistance. As the first step in determining whether {sup 18}F-labeled rhodamines might be useful as myocardial perfusion agents for PET, our objective was to develop synthetic methods for preparing the {sup 18}F-labeled compounds so that they could be evaluated in vivo. Rhodamine B was chosen as the prototype compound for development of the synthesis because the ethyl substituents on the amine moieties of rhodamine B protect them from side reactions, thus eliminating the need to include (and subsequently remove) protecting groups. The 2'-[{sup 18}F]fluoroethyl ester of rhodamine B was synthesized by heating rhodamine B lactone with [{sup 18}F]fluoroethyltosylate in acetonitrile at 165 deg. C for 30 min using [{sup 18}F]fluoroethyl tosylate, which was prepared by the reaction of ethyleneglycol ditosylate with Kryptofix 2.2.2, K{sub 2}CO{sub 3}, and [{sup 18}F]NaF in acetonitrile for 10 min at 90 deg. C. The product was purified by semi-preparative HPLC to produce the 2'-[{sup 18}F]fluoroethylester in >97% radiochemical purity with a specific activity of 1.3 GBq/{mu}mol, an isolated decay corrected yield of 35%, and a total synthesis time of 90 min.

  18. Deleterious Effects of Intra-arterial Administration of Particulate Steroids on Microvascular Perfusion in a Mouse Model.

    Science.gov (United States)

    Laemmel, Elisabeth; Segal, Nicolas; Mirshahi, Massoud; Azzazene, Dalel; Le Marchand, Sylvie; Wybier, Marc; Vicaut, Eric; Laredo, Jean-Denis

    2016-06-01

    Purpose To determine the in vivo effects of several particulate steroids on microvascular perfusion by using intravital microscopy in a mice model and to investigate the in vitro interactions between these particulate steroids and red blood cells (RBCs). Materials and Methods The study was conducted in agreement with the guidelines of the National Committee of Ethic Reflection on Animal Experimentation. By using intravital microscopy of mouse cremaster muscle, the in vivo effects of several particulate steroids on microvascular perfusion were assessed. Four to five mice were allocated to each of the following treatment groups: saline solution, dexamethasone sodium phosphate, a nonparticulate steroid, and the particulate steroids cortivazol, methylprednisolone, triamcinolone, and prednisolone. By using in vitro blood microcinematography and electron microscopy, the interactions between these steroids and human RBCs were studied. All results were analyzed by using nonparametric tests. Results With prednisolone, methylprednisolone, or triamcinolone, blood flow was rapidly and completely stopped in all the arterioles and venules (median RBC velocity in first-order arterioles, 5 minutes after administration was zero for these three groups) compared with a limited effect in mice treated with saline, dexamethasone, and cortivazol (20.3, 21.3, and 27.5 mm/sec, respectively; P effect was associated with a large decrease in the functional capillary density (4.21, 0, and 0 capillaries per millimeter for methylprednisolone, triamcinolone, or prednisolone, respectively, vs 21.0, 21.4, and 19.1 capillaries per millimeter in mice treated with saline, dexamethasone, and cortivazol, respectively; P steroids. Conclusion Several particulate steroids have an immediate and massive effect on microvascular perfusion because of formation of RBC aggregates associated with the transformation of RBCs into spiculated RBCs. (©) RSNA, 2016 Online supplemental material is available for this

  19. Correlation between semiquantitative myocardial perfusion score and absolute myocardial flow in 13N-ammonia PET

    International Nuclear Information System (INIS)

    Lee, Byeong Il; Kim, Jung Young; Min, Jung Joon; Song, Ho Chun; Bom, Hee Seung; Kim, Kye Hun; Kim, Su Jin; Lee, Jae Sung

    2007-01-01

    13 N-ammonia is a well known radiopharmaceutical for the measurement of a myocardial blood flow (MBF) non-invasively using PET-CT. In this study, we investigated a correlation between MBF obtained from dynamic imaging and myocardial perfusion score (MPS) obtained from static imaging for usefulness of cardiac PET study. Twelve patients (11 males, 1 female, 57.9 ± 8.6 years old) with suspicious coronary artery disease underwent PET-CT scan. Dynamic scans (6 min: 5 sec X 12, 10 sec X 6, 20 sec X 3, and 30 sec X 6) were initiated simultaneously with bolus injection of 11 MBq/kg 13 N-ammonia to acquire rest and stress image. Gating image was acquired during 13 minutes continuously. Nine-segment model (4 basal walls, 4 mid walls, and apex) was used for a measurement of MBF. Time activity curve of input function and myocardium was extracted from ROI methods in 9 regions for quantification. The MPS were evaluated using quantitative analysis software. To compare between 20-segment model and 9-segment model, 6 basal segments were excluded and averaged segmental scores were used. There are weak correlation between MBF (rest, 0.18-2.38 ml/min/g; stress, 0.40-4.95 ml/min/g) and MPS (rest 22-91%, stress, 14-90%), however the correlation coefficient between corrected MBF and MPS in rest state was higher than stress state (rest r=0.59; stress r=0.80). As a thickening increased, correlation between MBF and MPS also showed good correlation at each segments. Corrected and translated MPS as its characteristics using 13 N-ammonia showed good correlation with absolute MBF measured by dynamic image in this study. Therefore, we showed MPS is one of good indices which reflect MBF. We anticipate PET-CT could be used as useful tool for evaluation of myocardial function in nuclear cardiac study

  20. Accuracy of F-DOPA PET and perfusion-MRI for differentiating radionecrotic from progressive brain metastases after radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Cicone, Francesco; Papa, Annalisa; Scopinaro, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; ' ' Sapienza' ' Univ., Rome (Italy). Dept. of Surgical and Medicine Sciences and Translational Medicine; Minniti, Giuseppe; Scaringi, Claudia; Maurizi Enrici, Riccardo [' ' Sapienza' ' Univ., Rome (Italy). Dept. of Surgical and Medicine Sciences and Translational Medicine; Sant' Andrea Hospital, Rome (Italy). Unit of Radiotherapy; Romano, Andrea; Tavanti, Francesca; Bozzao, Alessandro [Sant' Andrea Hospital, Rome (Italy). Unit of Neuroradiology; Rome Univ. (Italy). Dept. of Neurosciences, Mental Health and Sensory Organs (Ne.S.M.O.S.)

    2015-01-15

    We assessed the performance of 6-[{sup 18}F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET for differentiating radionecrosis (RN) from tumour progression (PD) in a population of patients with brain metastases, treated with stereotactic radiosurgery. The accuracy of F-DOPA PET was compared with that of perfusion-weighted magnetic resonance (perfusion-MR). In 42 patients with a total of 50 brain metastases from various primaries F-DOPA PET/CT was performed because of suspected radiological progression at the site of previously irradiated brain metastasis. Several semiquantitative PET parameters were recorded, and their diagnostic accuracy was compared by receiver operating characteristic curve analyses. The diagnosis was established by either surgery or follow-up. A comparison was made between F-DOPA PET and perfusion-MR sequences acquired no more than 3 weeks apart. Definitive outcome was available in 46 of the 50 lesions (20 PD, 26 RN). Of the 46 lesions, 11 were surgically excised while in the remaining 35 lesions the diagnosis was established by radiological and clinical criteria. The best diagnostic performance was obtained using the semiquantitative PET parameter maximum lesion to maximum background uptake ratio (SUVL{sub max}/Bkgr{sub max}). With a cut-off value of 1.59, a sensitivity of 90 % and a specificity of 92.3 % were achieved in differentiating RN from PD lesions (accuracy 91.3 %). Relative cerebral blood volume (rCBV) derived from perfusion-MR was available for comparison in 37 of the 46 metastases. Overall accuracy of rCBV was lower than that of all semiquantitative PET parameters under study. The best differentiating rCBV cut-off value was 2.14; this yielded a sensitivity of 86.7 % and a specificity of 68.2 % (accuracy 75.6 %). F-DOPA PET is a highly accurate tool for differentiating RN from PD brain metastases after stereotactic radiosurgery. In this specific setting, F-DOPA PET seems to perform better than perfusion-MR. (orig.)

  1. Motion detection and correction for dynamic 15O-water myocardial perfusion PET studies

    International Nuclear Information System (INIS)

    Naum, Alexandru; Laaksonen, Marko S.; Oikonen, Vesa; Teraes, Mika; Jaervisalo, Mikko J.; Knuuti, Juhani; Tuunanen, Helena; Nuutila, Pirjo; Kemppainen, Jukka

    2005-01-01

    Patient motion during dynamic PET studies is a well-documented source of errors. The purpose of this study was to investigate the incidence of frame-to-frame motion in dynamic 15 O-water myocardial perfusion PET studies, to test the efficacy of motion correction methods and to study whether implementation of motion correction would have an impact on the perfusion results. We developed a motion detection procedure using external radioactive skin markers and frame-to-frame alignment. To evaluate motion, marker coordinates inside the field of view were determined in each frame for each study. The highest number of frames with identical spatial coordinates during the study were defined as ''non-moved''. Movement was considered present if even one marker changed position, by one pixel/frame compared with reference, in one axis, and such frames were defined as ''moved''. We tested manual, in-house-developed motion correction software and an automatic motion correction using a rigid body point model implemented in MIPAV (Medical Image Processing, Analysis and Visualisation) software. After motion correction, remaining motion was re-analysed. Myocardial blood flow (MBF) values were calculated for both non-corrected and motion-corrected datasets. At rest, patient motion was found in 18% of the frames, but during pharmacological stress the fraction increased to 45% and during physical exercise it rose to 80%. Both motion correction algorithms significantly decreased (p<0.006) the number of moved frames and the amplitude of motion (p<0.04). Motion correction significantly increased MBF results during bicycle exercise (p<0.02). At rest or during adenosine infusion, the motion correction had no significant effects on MBF values. Significant motion is a common phenomenon in dynamic cardiac studies during adenosine infusion but especially during exercise. Applying motion correction for the data acquired during exercise clearly changed the MBF results, indicating that motion

  2. Diffusion and perfusion correlates of the {sup 18}F-MISO PET lesion in acute stroke: pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Alawneh, Josef A.; Marrapu, S.T.; Jensen-Kondering, Ulf; Morris, Rhiannon S.; Jones, P.S. [University of Cambridge, Stroke Research Group, Department of Clinical Neurosciences, Cambridge (United Kingdom); Moustafa, Ramez R. [University of Cambridge, Stroke Research Group, Department of Clinical Neurosciences, Cambridge (United Kingdom); Ain Shams University, Department of Neurology, Cairo (Egypt); Aigbirhio, Franklin I.; Fryer, Tim D.; Carpenter, T.A. [University of Cambridge, Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, Cambridge (United Kingdom); Warburton, Elizabeth A. [University of Cambridge, Stroke Research Group, Department of Clinical Neurosciences, Cambridge (United Kingdom); Stroke Unit, Addenbrooke' s Hospital, Cambridge (United Kingdom); Baron, Jean-Claude [University of Cambridge, Stroke Research Group, Department of Clinical Neurosciences, Cambridge (United Kingdom); Universite Paris Descartes, INSERM U894, Centre Hospitalier Sainte-Anne, Paris (France)

    2014-04-15

    Mapping the ischaemic penumbra in acute stroke is of considerable clinical interest. For this purpose, mapping tissue hypoxia with {sup 18}F-misonidazole (FMISO) PET is attractive, and is straightforward compared to {sup 15}O PET. Given the current emphasis on penumbra imaging using diffusion/perfusion MR or CT perfusion, investigating the relationships between FMISO uptake and abnormalities with these modalities is important. According to a prospective design, three patients (age 54-81 years; admission NIH stroke scale scores 16-22) with an anterior circulation stroke and extensive penumbra on CT- or MR-based perfusion imaging successfully completed FMISO PET, diffusion-weighted imaging and MR angiography 6-26 h after stroke onset, and follow-up FLAIR to map the final infarction. All had persistent proximal occlusion and a poor outcome despite thrombolysis. Significant FMISO trapping was defined voxel-wise relative to ten age-matched controls and mapped onto coregistered maps of the penumbra and irreversibly damaged ischaemic core. FMISO trapping was present in all patients (volume range 18-119 ml) and overlapped mainly with the penumbra but also with the core in each patient. There was a significant (p ≤ 0.001) correlation in the expected direction between FMISO uptake and perfusion, with a sharp FMISO uptake bend around the expected penumbra threshold. FMISO uptake had the expected overlap with the penumbra and relationship with local perfusion. However, consistent with recent animal data, our study suggests FMISO trapping may not be specific to the penumbra. If confirmed in larger samples, this preliminary finding would have potential implications for the clinical application of FMISO PET in acute ischaemic stroke. (orig.)

  3. SPM analysis of brain perfusion SPECT and F-18 FDG PET in the Korean autosomal dominant nocturnal frontal lobe epilepsy family

    International Nuclear Information System (INIS)

    Won, Kyoung Sook; Zeon, Seok Kil

    2004-01-01

    This study attempted to investigate the specific pattern of brain perfusion and glucose metabolism in the Korean autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) family. Using Tc-99m ECD brain perfusion SPECT. we assessed brain perfusion in 6 patients at interictal period and 5 patients at ictal period. Interictal F-18 FDG PET was performed on 6 affected family members. The scans were statistically analyzed by using statistical parametric mapping (SPM99). The data of the affected family members were compared to those of the control subjects. Interictal F-18 FDG PET SPM group analysis showed decreased glucose metabolism over the left middle and superior frontal gyri and the left central regions including the anterior parietal lobe. There was a less pronounced decrease in glucose uptake in the right anterior superior frontal gyrus. Interictal brain perfusion SPECT SPM group analysis showed similar pattern of decreased perfusion compared to those of interictal F-18 FDG PET. Ictal brain perfusion SPECT SPM group analysis revealed increased perfusion over the left pre-and postcentral gyri and less pronounced increased perfusion in the right postcentral gyrus. lnterictal F -18 PET and brain perfusion SPECT SPM group analysis suggest that major abnormalities of ADNFLE family are in the left frontal lobe. These findings may be helpful to elucidate the pathophysiological mechanism of this rare disease entity

  4. SPM analysis of brain perfusion SPECT and F-18 FDG PET in the Korean autosomal dominant nocturnal frontal lobe epilepsy family

    Energy Technology Data Exchange (ETDEWEB)

    Won, Kyoung Sook; Zeon, Seok Kil [Keimyung University Dongsan Medical Center, Daegu (Korea, Republic of)

    2004-07-01

    This study attempted to investigate the specific pattern of brain perfusion and glucose metabolism in the Korean autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) family. Using Tc-99m ECD brain perfusion SPECT. we assessed brain perfusion in 6 patients at interictal period and 5 patients at ictal period. Interictal F-18 FDG PET was performed on 6 affected family members. The scans were statistically analyzed by using statistical parametric mapping (SPM99). The data of the affected family members were compared to those of the control subjects. Interictal F-18 FDG PET SPM group analysis showed decreased glucose metabolism over the left middle and superior frontal gyri and the left central regions including the anterior parietal lobe. There was a less pronounced decrease in glucose uptake in the right anterior superior frontal gyrus. Interictal brain perfusion SPECT SPM group analysis showed similar pattern of decreased perfusion compared to those of interictal F-18 FDG PET. Ictal brain perfusion SPECT SPM group analysis revealed increased perfusion over the left pre-and postcentral gyri and less pronounced increased perfusion in the right postcentral gyrus. lnterictal F -18 PET and brain perfusion SPECT SPM group analysis suggest that major abnormalities of ADNFLE family are in the left frontal lobe. These findings may be helpful to elucidate the pathophysiological mechanism of this rare disease entity.

  5. Multimodality functional imaging of spontaneous canine tumors using 64CU-ATSM and 18FDG PET/CT and dynamic contrast enhanced perfusion CT

    DEFF Research Database (Denmark)

    Hansen, Anders E; Kristensen, Annemarie T; Law, Ian

    2012-01-01

    To compare the distribution and uptake of the hypoxia tracer (64)Cu-diacetyl-bis(N(4)-methylthiosemicarbazone) ((64)Cu-ATSM) PET/CT, FDG PET/CT and dynamic contrast enhanced perfusion CT (DCE-pCT) in spontaneous canine tumors. In addition (64)Cu-ATSM distribution over time was evaluated.......To compare the distribution and uptake of the hypoxia tracer (64)Cu-diacetyl-bis(N(4)-methylthiosemicarbazone) ((64)Cu-ATSM) PET/CT, FDG PET/CT and dynamic contrast enhanced perfusion CT (DCE-pCT) in spontaneous canine tumors. In addition (64)Cu-ATSM distribution over time was evaluated....

  6. Myocardial perfusion of infarcted and normal myocardium in propofol-anesthetized minipigs using 82Rubidium PET

    DEFF Research Database (Denmark)

    Rasmussen, Thomas; Larsen, Bjarke Follin; Kastrup, Jens

    2016-01-01

    Cardiac Rubidium-82 (82Rb) positron-emission-tomography (PET) is a good method for quantification of myocardial blood flow in man. Quantification of myocardial blood flow in animals to evaluate new treatment strategies or to understand underlying disease is also of great interest but raises some...... challenges. Animals, which have been anesthetized during PET acquisition, might react differently to used stress medications, and therefore difficulties might exist while evaluating the resulting PET images using standard software packages from commercial vendors optimized for human hearts. Furthermore...... propofol, used for anesthesia, can influence myocardial perfusion and coronary flow reserve due to its vasorelaxant effect, and interactions might exist between propofol and used stress agents, potentially affecting the result of the examination. We present cardiac 82Rb-PET studies performed in propofol...

  7. Multimodal correlation of dynamic [{sup 18}F]-AV-1451 perfusion PET and neuronal hypometabolism in [{sup 18}F]-FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Hammes, Jochen; Leuwer, Isabel [University Hospital Cologne, Multimodal Neuroimaging Group, Department of Nuclear Medicine, Cologne (Germany); Bischof, Gerard N. [University Hospital Cologne, Multimodal Neuroimaging Group, Department of Nuclear Medicine, Cologne (Germany); INM-3, Research Center Juelich, Juelich (Germany); Drzezga, Alexander [University Hospital Cologne, Multimodal Neuroimaging Group, Department of Nuclear Medicine, Cologne (Germany); German Center for Neurodegeneration (DZNE), Berlin (Germany); Eimeren, Thilo van [University Hospital Cologne, Multimodal Neuroimaging Group, Department of Nuclear Medicine, Cologne (Germany); INM-3, Research Center Juelich, Juelich (Germany); German Center for Neurodegeneration (DZNE), Berlin (Germany)

    2017-12-15

    Cerebral glucose metabolism measured with [18F]-FDG PET is a well established marker of neuronal dysfunction in neurodegeneration. The tau-protein tracer [18F]-AV-1451 PET is currently under evaluation and shows promising results. Here, we assess the feasibility of early perfusion imaging with AV-1451 as a substite for FDG PET in assessing neuronal injury. Twenty patients with suspected neurodegeneration underwent FDG and early phase AV-1451 PET imaging. Ten one-minute timeframes were acquired after application of 200 MBq AV-1451. FDG images were acquired on a different date according to clinical protocol. Early AV-1451 timeframes were coregistered to individual FDG-scans and spatially normalized. Voxel-wise intermodal correlations were calculated on within-subject level for every possible time window. The window with highest pooled correlation was considered optimal. Z-transformed deviation maps (ZMs) were created from both FDG and early AV-1451 images, comparing against FDG images of healthy controls. Regional patterns and extent of perfusion deficits were highly comparable to metabolic deficits. Best results were observed in a time window from 60 to 360 s (r = 0.86). Correlation strength ranged from r = 0.96 (subcortical gray matter) to 0.83 (frontal lobe) in regional analysis. ZMs of early AV-1451 and FDG images were highly similar. Perfusion imaging with AV-1451 is a valid biomarker for assessment of neuronal dysfunction in neurodegenerative diseases. Radiation exposure and complexity of the diagnostic workup could be reduced significantly by routine acquisition of early AV-1451 images, sparing additional FDG PET. (orig.)

  8. Clinical use of quantitative cardiac perfusion PET: rationale, modalities and possible indications. Position paper of the Cardiovascular Committee of the European Association of Nuclear Medicine (EANM)

    International Nuclear Information System (INIS)

    Sciagra, Roberto; Passeri, Alessandro; Bucerius, Jan; Verberne, Hein J.; Slart, Riemer H.J.A.; Lindner, Oliver; Gimelli, Alessia; Hyafil, Fabien; Agostini, Denis; Uebleis, Christopher; Hacker, Marcus

    2016-01-01

    Until recently, PET was regarded as a luxurious way of performing myocardial perfusion scintigraphy, with excellent image quality and diagnostic capabilities that hardly justified the additional cost and procedural effort. Quantitative perfusion PET was considered a major improvement over standard qualitative imaging, because it allows the measurement of parameters not otherwise available, but for many years its use was confined to academic and research settings. In recent years, however, several factors have contributed to the renewal of interest in quantitative perfusion PET, which has become a much more readily accessible technique due to progress in hardware and the availability of dedicated and user-friendly platforms and programs. In spite of this evolution and of the growing evidence that quantitative perfusion PET can play a role in the clinical setting, there are not yet clear indications for its clinical use. Therefore, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, decided to examine the current literature on quantitative perfusion PET to (1) evaluate the rationale for its clinical use, (2) identify the main methodological requirements, (3) identify the remaining technical difficulties, (4) define the most reliable interpretation criteria, and finally (5) tentatively delineate currently acceptable and possibly appropriate clinical indications. The present position paper must be considered as a starting point aiming to promote a wider use of quantitative perfusion PET and to encourage the conception and execution of the studies needed to definitely establish its role in clinical practice. (orig.)

  9. 13N-Ammonia pet-derived ventricular synchrony correlates with myocardial perfusion reserve better than left ventricular ejection fraction : A study in infarcted patients

    NARCIS (Netherlands)

    Juarez-Orozco, Luis Eduardo; Slart, Riemer; Tio, Rene A.; Inarra-Talboy, Fernando; Monroy, Andrea; Ayala-German, AnaGabriela; Dierckx, Rudi A.; Rosas, Erick Alexanderson

    2016-01-01

    Background: PET myocardial perfusion allows myocardial perfusion reserve (MPR) quantification as well as left ventricular ejection fraction (LVEF) and synchrony estimation through phase analysis. There is a relationship between MPR and LVEF and both have proven prognostic value in coronary artery

  10. Role of FDG-PET/MRI, FDG-PET/CT, and Dynamic Susceptibility Contrast Perfusion MRI in Differentiating Radiation Necrosis from Tumor Recurrence in Glioblastomas.

    Science.gov (United States)

    Hojjati, Mojgan; Badve, Chaitra; Garg, Vasant; Tatsuoka, Curtis; Rogers, Lisa; Sloan, Andrew; Faulhaber, Peter; Ros, Pablo R; Wolansky, Leo J

    2018-01-01

    To compare the utility of quantitative PET/MRI, dynamic susceptibility contrast (DSC) perfusion MRI (pMRI), and PET/CT in differentiating radiation necrosis (RN) from tumor recurrence (TR) in patients with treated glioblastoma multiforme (GBM). The study included 24 patients with GBM treated with surgery, radiotherapy, and temozolomide who presented with progression on imaging follow-up. All patients underwent PET/MRI and pMRI during a single examination. Additionally, 19 of 24 patients underwent PET/CT on the same day. Diagnosis was established by pathology in 17 of 24 and by clinical/radiologic consensus in 7 of 24. For the quantitative PET/MRI and PET/CT analysis, a region of interest (ROI) was drawn around each lesion and within the contralateral white matter. Lesion to contralateral white matter ratios for relative maximum, mean, and median were calculated. For pMRI, lesion ROI was drawn on the cerebral blood volume (CBV) maps and histogram metrics were calculated. Diagnostic performance for each metric was assessed using receiver operating characteristic curve analysis and area under curve (AUC) was calculated. In 24 patients, 28 lesions were identified. For PET/MRI, relative mean ≥ 1.31 resulted in AUC of .94 with both sensitivity and negative predictive values (NPVs) of 100%. For pMRI, CBV max ≥3.32 yielded an AUC of .94 with both sensitivity and NPV measuring 100%. The joint model utilizing r-mean (PET/MRI) and CBV mode (pMRI) resulted in AUC of 1.0. Our study demonstrates that quantitative PET/MRI parameters in combination with DSC pMRI provide the best diagnostic utility in distinguishing RN from TR in treated GBMs. © 2017 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

  11. Comparison of 18F-FET PET and perfusion-weighted MRI for glioma grading. A hybrid PET/MR study

    International Nuclear Information System (INIS)

    Verger, Antoine; Filss, Christian P.; Lohmann, Philipp; Stoffels, Gabriele; Rota Kops, Elena; Sabel, Michael; Wittsack, Hans J.; Galldiks, Norbert; Fink, Gereon R.; Shah, Nadim J.; Langen, Karl-Josef

    2017-01-01

    Both perfusion-weighted MR imaging (PWI) and O-(2- 18 F-fluoroethyl)-L-tyrosine PET ( 18 F-FET) provide grading information in cerebral gliomas. The aim of this study was to compare the diagnostic value of 18 F-FET PET and PWI for tumor grading in a series of patients with newly diagnosed, untreated gliomas using an integrated PET/MR scanner. Seventy-two patients with untreated gliomas [22 low-grade gliomas (LGG), and 50 high-grade gliomas (HGG)] were investigated with 18 F-FET PET and PWI using a hybrid PET/MR scanner. After visual inspection of PET and PWI maps (rCBV, rCBF, MTT), volumes of interest (VOIs) with a diameter of 16 mm were centered upon the maximum of abnormality in the tumor area in each modality and the contralateral unaffected hemisphere. Mean and maximum tumor-to-brain ratios (TBR mean , TBR max ) were calculated. In addition, Time-to-Peak (TTP) and slopes of time-activity curves were calculated for 18 F-FET PET. Diagnostic accuracies of 18 F-FET PET and PWI for differentiating low-grade glioma (LGG) from high-grade glioma (HGG) were evaluated by receiver operating characteristic analyses (area under the curve; AUC). The diagnostic accuracy of 18 F-FET PET and PWI to discriminate LGG from HGG was similar with highest AUC values for TBR mean and TBR max of 18 F-FET PET uptake (0.80, 0.83) and for TBR mean and TBR max of rCBV (0.80, 0.81). In case of increased signal in the tumor area with both methods (n = 32), local hot-spots were incongruent in 25 patients (78%) with a mean distance of 10.6 ± 9.5 mm. Dynamic FET PET and combination of different parameters did not further improve diagnostic accuracy. Both 18 F-FET PET and PWI discriminate LGG from HGG with similar diagnostic performance. Regional abnormalities in the tumor area are usually not congruent indicating that tumor grading by 18 F-FET PET and PWI is based on different pathophysiological phenomena. (orig.)

  12. Comparison of {sup 18}F-FET PET and perfusion-weighted MRI for glioma grading. A hybrid PET/MR study

    Energy Technology Data Exchange (ETDEWEB)

    Verger, Antoine [Forschungszentrum Juelich, Institute of Neuroscience and Medicine (INM-3, -4), Juelich (Germany); Lorraine University, Department of Nuclear Medicine and Nancyclotep Imaging Platform, CHRU Nancy, Nancy (France); Lorraine University, IADI, INSERM, UMR 947, Nancy (France); Filss, Christian P. [Forschungszentrum Juelich, Institute of Neuroscience and Medicine (INM-3, -4), Juelich (Germany); RWTH Aachen University Hospital, Department of Nuclear Medicine, Aachen (Germany); Lohmann, Philipp; Stoffels, Gabriele; Rota Kops, Elena [Forschungszentrum Juelich, Institute of Neuroscience and Medicine (INM-3, -4), Juelich (Germany); Sabel, Michael [University of Duesseldorf, Department of Neurosurgery, Duesseldorf (Germany); Wittsack, Hans J. [University Duesseldorf, Department of Diagnostic and Interventional Radiology, Medical Faculty, Duesseldorf (Germany); Galldiks, Norbert; Fink, Gereon R. [Forschungszentrum Juelich, Institute of Neuroscience and Medicine (INM-3, -4), Juelich (Germany); University of Cologne, Department of Neurology, Cologne (Germany); University of Cologne and Bonn, Center of Integrated Oncology (CIO), Bonn (Germany); Shah, Nadim J. [Forschungszentrum Juelich, Institute of Neuroscience and Medicine (INM-3, -4), Juelich (Germany); RWTH Aachen University Hospital, Department of Neurology, Aachen (Germany); Juelich-Aachen Research Alliance (JARA), Section JARA-Brain, Juelich (Germany); Langen, Karl-Josef [Forschungszentrum Juelich, Institute of Neuroscience and Medicine (INM-3, -4), Juelich (Germany); RWTH Aachen University Hospital, Department of Nuclear Medicine, Aachen (Germany); Juelich-Aachen Research Alliance (JARA), Section JARA-Brain, Juelich (Germany)

    2017-12-15

    Both perfusion-weighted MR imaging (PWI) and O-(2-{sup 18}F-fluoroethyl)-L-tyrosine PET ({sup 18}F-FET) provide grading information in cerebral gliomas. The aim of this study was to compare the diagnostic value of {sup 18}F-FET PET and PWI for tumor grading in a series of patients with newly diagnosed, untreated gliomas using an integrated PET/MR scanner. Seventy-two patients with untreated gliomas [22 low-grade gliomas (LGG), and 50 high-grade gliomas (HGG)] were investigated with {sup 18}F-FET PET and PWI using a hybrid PET/MR scanner. After visual inspection of PET and PWI maps (rCBV, rCBF, MTT), volumes of interest (VOIs) with a diameter of 16 mm were centered upon the maximum of abnormality in the tumor area in each modality and the contralateral unaffected hemisphere. Mean and maximum tumor-to-brain ratios (TBR{sub mean}, TBR{sub max}) were calculated. In addition, Time-to-Peak (TTP) and slopes of time-activity curves were calculated for {sup 18}F-FET PET. Diagnostic accuracies of {sup 18}F-FET PET and PWI for differentiating low-grade glioma (LGG) from high-grade glioma (HGG) were evaluated by receiver operating characteristic analyses (area under the curve; AUC). The diagnostic accuracy of {sup 18}F-FET PET and PWI to discriminate LGG from HGG was similar with highest AUC values for TBR{sub mean} and TBR{sub max} of {sup 18}F-FET PET uptake (0.80, 0.83) and for TBR{sub mean} and TBR{sub max} of rCBV (0.80, 0.81). In case of increased signal in the tumor area with both methods (n = 32), local hot-spots were incongruent in 25 patients (78%) with a mean distance of 10.6 ± 9.5 mm. Dynamic FET PET and combination of different parameters did not further improve diagnostic accuracy. Both {sup 18}F-FET PET and PWI discriminate LGG from HGG with similar diagnostic performance. Regional abnormalities in the tumor area are usually not congruent indicating that tumor grading by {sup 18}F-FET PET and PWI is based on different pathophysiological phenomena. (orig.)

  13. Myocardial perfusion quantification using simultaneously acquired 13 NH3 -ammonia PET and dynamic contrast-enhanced MRI in patients at rest and stress.

    Science.gov (United States)

    Kunze, Karl P; Nekolla, Stephan G; Rischpler, Christoph; Zhang, Shelley HuaLei; Hayes, Carmel; Langwieser, Nicolas; Ibrahim, Tareq; Laugwitz, Karl-Ludwig; Schwaiger, Markus

    2018-04-19

    Systematic differences with respect to myocardial perfusion quantification exist between DCE-MRI and PET. Using the potential of integrated PET/MRI, this study was conceived to compare perfusion quantification on the basis of simultaneously acquired 13 NH 3 -ammonia PET and DCE-MRI data in patients at rest and stress. Twenty-nine patients were examined on a 3T PET/MRI scanner. DCE-MRI was implemented in dual-sequence design and additional T 1 mapping for signal normalization. Four different deconvolution methods including a modified version of the Fermi technique were compared against 13 NH 3 -ammonia results. Cohort-average flow comparison yielded higher resting flows for DCE-MRI than for PET and, therefore, significantly lower DCE-MRI perfusion ratios under the common assumption of equal arterial and tissue hematocrit. Absolute flow values were strongly correlated in both slice-average (R 2  = 0.82) and regional (R 2  = 0.7) evaluations. Different DCE-MRI deconvolution methods yielded similar flow result with exception of an unconstrained Fermi method exhibiting outliers at high flows when compared with PET. Thresholds for Ischemia classification may not be directly tradable between PET and MRI flow values. Differences in perfusion ratios between PET and DCE-MRI may be lifted by using stress/rest-specific hematocrit conversion. Proper physiological constraints are advised in model-constrained deconvolution. © 2018 International Society for Magnetic Resonance in Medicine.

  14. Comparison of the Peripheral Reactive Hyperemia Index with Myocardial Perfusion Reserve byRb PET/CT in HIV-Infected Patients

    DEFF Research Database (Denmark)

    Ørbæk, Mathilde; Hasbak, Philip; Sejersten Ripa, Rasmus

    2017-01-01

    (CAD) seems to be higher in HIV-infected patients and an accurate risk prediction of CAD is of high importance for optimal long term treatment. In this study, we assessed the correlation of the endoPAT, which is an office-based CVD screening tool with the myocardial perfusion reserve by82-rubidium PET...... undergone measurement of the myocardial perfusion reserve by82-rubidium PET/CT for study purposes. We found an inverse correlation between the reactive hyperemia index and the myocardial perfusion reserve which most likely indicates different vascular physiology. This study did not find evidence to suggest...

  15. Correlation of 68Ga Ventilation-Perfusion PET/CT with Pulmonary Function Test Indices for Assessing Lung Function.

    Science.gov (United States)

    Le Roux, Pierre-Yves; Siva, Shankar; Steinfort, Daniel P; Callahan, Jason; Eu, Peter; Irving, Lou B; Hicks, Rodney J; Hofman, Michael S

    2015-11-01

    Pulmonary function tests (PFTs) are routinely used to assess lung function, but they do not provide information about regional pulmonary dysfunction. We aimed to assess correlation of quantitative ventilation-perfusion (V/Q) PET/CT with PFT indices. Thirty patients underwent V/Q PET/CT and PFT. Respiration-gated images were acquired after inhalation of (68)Ga-carbon nanoparticles and administration of (68)Ga-macroaggregated albumin. Functional volumes were calculated by dividing the volume of normal ventilated and perfused (%NVQ), unmatched and matched defects by the total lung volume. These functional volumes were correlated with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, and diffusing capacity for carbon monoxide (DLCO). All functional volumes were significantly different in patients with chronic obstructive pulmonary disease (P volume of unmatched defects (r = -0.55). Considering %NVQ only, a cutoff value of 90% correctly categorized 28 of 30 patients with or without significant pulmonary function impairment. Our study demonstrates strong correlations between V/Q PET/CT functional volumes and PFT parameters. Because V/Q PET/CT is able to assess regional lung function, these data support the feasibility of its use in radiation therapy and preoperative planning and assessing pulmonary dysfunction in a variety of respiratory diseases. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  16. Detection and severity classification of extracardiac interference in {sup 82}Rb PET myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Orton, Elizabeth J., E-mail: eorton@physics.carleton.ca; Kemp, Robert A. de; Glenn Wells, R. [Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7 (Canada); Department of Physics, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada); Al Harbi, Ibraheem [Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7 (Canada); Department of Medicine (Cardiology), King Fahad Hospital, Medina 42351 (Saudi Arabia); Klein, Ran [Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7 (Canada); Department of Biomedical Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada); Beanlands, Rob S. B. [Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7 (Canada)

    2014-10-15

    Purpose: Myocardial perfusion imaging (MPI) is used for diagnosis and prognosis of coronary artery disease. When MPI studies are performed with positron emission tomography (PET) and the radioactive tracer rubidium-82 chloride ({sup 82}Rb), a small but non-negligible fraction of studies (∼10%) suffer from extracardiac interference: high levels of tracer uptake in structures adjacent to the heart which mask the true cardiac tracer uptake. At present, there are no clinically available options for automated detection or correction of this problem. This work presents an algorithm that detects and classifies the severity of extracardiac interference in {sup 82}Rb PET MPI images and reports the accuracy and failure rate of the method. Methods: A set of 200 {sup 82}Rb PET MPI images were reviewed by a trained nuclear cardiologist and interference severity reported on a four-class scale, from absent to severe. An automated algorithm was developed that compares uptake at the external border of the myocardium to three thresholds, separating the four interference severity classes. A minimum area of interference was required, and the search region was limited to that facing the stomach wall and spleen. Maximizing concordance (Cohen’s Kappa) and minimizing failure rate for the set of 200 clinician-read images were used to find the optimal population-based constants defining search limit and minimum area parameters and the thresholds for the algorithm. Tenfold stratified cross-validation was used to find optimal thresholds and report accuracy measures (sensitivity, specificity, and Kappa). Results: The algorithm was capable of detecting interference with a mean [95% confidence interval] sensitivity/specificity/Kappa of 0.97 [0.94, 1.00]/0.82 [0.66, 0.98]/0.79 [0.65, 0.92], and a failure rate of 1.0% ± 0.2%. The four-class overall Kappa was 0.72 [0.64, 0.81]. Separation of mild versus moderate-or-greater interference was performed with good accuracy (sensitivity

  17. PET scan perfusion imaging in the Prader-Willi syndrome: new insights into the psychiatric and social disturbances

    International Nuclear Information System (INIS)

    Mantoulan, C.; Payoux, P.; Mantoulan, C.; Diene, G.; Glattard, M.; Molinas, C.; Tauber, M.; Payoux, P.; Sevely, A.; Glattard, M.; Roge, B.; Molinas, C.; Tauber, M.; Zilbovicius, M.; Celsis, P.; Celsis, P.

    2011-01-01

    The Prader-Willi syndrome (PWS), a rare multisystem genetic disease, leads to severe disabilities, such as morbid obesity, endocrine dysfunctions, psychiatric disorders, and social disturbances. We explored the whole brain of patients with PWS to detect abnormalities that might explain the behavioral and social disturbances, as well as the psychiatric disorders of these patients. Nine patients with PWS (six males, three females; mean age 16.4 years) underwent a positron emission tomography (PET) scan with H(2)(15)O as a tracer to measure regional cerebral blood flow (rCBF). The images were compared with those acquired from nine controls (six males, three females; mean age 21.2 years). A morphologic magnetic resonance imaging (MRI) was also performed in PWS patients, and their cognitive and behavioral skills were assessed with Wechsler Intelligence Scale for Children III and the Child Behavior Check List (CBCL). The MRI images showed no evident anatomic abnormalities, whereas PET scans revealed hypo-perfused brain regions in PWS patients compared with controls, particularly in the anterior cingulum and superior temporal regions. We observed a significant relationship (P≤0.05) between rCBF in the hypo-perfused regions and CBCL scores. The functional consequences of these perfusion abnormalities in specific brain regions might explain the behavioral and social problems observed in these individuals. (authors)

  18. Quantitative perfusion parameters in a cohort of patients with no known ischemic heart disease and normal myocardial perfusion imaging studied by 82Rb-PET

    DEFF Research Database (Denmark)

    Hoff, Camilla; Balche, Abdallah; Majgaard, J

    Purpose 82Rb perfusion PET allows for visual as well as quantitative interpretation of myocardial function. Whereas visual interpretation relies on intra-individual redistribution of the tracer between rest and stress studies, quantitative interpretation of absolute flow values requires robust.......86 mL/g/min. Global coronary flow reserve (CFR) was 2.81 (±SD 0.71). EF at rest was 65.3% (±SD 10) and during stress 69% (±SD 12.3), yielding an EF reserve of 4.5%. TPD at rest and stress was 6% (±SD 4). Conclusion Based on a representative population of patients in which coronary artery disease...

  19. Correlation of Perfusion MRI and 18F-FDG PET Imaging Biomarkers for Monitoring Regorafenib Therapy in Experimental Colon Carcinomas with Immunohistochemical Validation

    Science.gov (United States)

    Eschbach, Ralf S.; Fendler, Wolfgang P.; Kazmierczak, Philipp M.; Hacker, Marcus; Rominger, Axel; Carlsen, Janette; Hirner-Eppeneder, Heidrun; Schuster, Jessica; Moser, Matthias; Havla, Lukas; Schneider, Moritz J.; Ingrisch, Michael; Spaeth, Lukas; Reiser, Maximilian F.; Nikolaou, Konstantin; Cyran, Clemens C.

    2015-01-01

    Objectives To investigate a multimodal, multiparametric perfusion MRI / 18F-fluoro-deoxyglucose-(18F-FDG)-PET imaging protocol for monitoring regorafenib therapy effects on experimental colorectal adenocarcinomas in rats with immunohistochemical validation. Materials and Methods Human colorectal adenocarcinoma xenografts (HT-29) were implanted subcutaneously in n = 17 (n = 10 therapy group; n = 7 control group) female athymic nude rats (Hsd:RH-Foxn1rnu). Animals were imaged at baseline and after a one-week daily treatment protocol with regorafenib (10 mg/kg bodyweight) using a multimodal, multiparametric perfusion MRI/18F-FDG-PET imaging protocol. In perfusion MRI, quantitative parameters of plasma flow (PF, mL/100 mL/min), plasma volume (PV, %) and endothelial permeability-surface area product (PS, mL/100 mL/min) were calculated. In 18F-FDG-PET, tumor-to-background-ratio (TTB) was calculated. Perfusion MRI parameters were correlated with TTB and immunohistochemical assessments of tumor microvascular density (CD-31) and cell proliferation (Ki-67). Results Regorafenib significantly (pregorafenib therapy effects on experimental colorectal adenocarcinomas in vivo with significant correlations between perfusion MRI parameters and 18F-FDG-PET validated by immunohistochemistry. PMID:25668193

  20. Assessment of input function distortions on kinetic model parameters in simulated dynamic 82Rb PET perfusion studies

    International Nuclear Information System (INIS)

    Meyer, Carsten; Peligrad, Dragos-Nicolae; Weibrecht, Martin

    2007-01-01

    Cardiac 82 rubidium dynamic PET studies allow quantifying absolute myocardial perfusion by using tracer kinetic modeling. Here, the accurate measurement of the input function, i.e. the tracer concentration in blood plasma, is a major challenge. This measurement is deteriorated by inappropriate temporal sampling, spillover, etc. Such effects may influence the measured input peak value and the measured blood pool clearance. The aim of our study is to evaluate the effect of input function distortions on the myocardial perfusion as estimated by the model. To this end, we simulate noise-free myocardium time activity curves (TACs) with a two-compartment kinetic model. The input function to the model is a generic analytical function. Distortions of this function have been introduced by varying its parameters. Using the distorted input function, the compartment model has been fitted to the simulated myocardium TAC. This analysis has been performed for various sets of model parameters covering a physiologically relevant range. The evaluation shows that ±10% error in the input peak value can easily lead to ±10-25% error in the model parameter K 1 , which relates to myocardial perfusion. Variations in the input function tail are generally less relevant. We conclude that an accurate estimation especially of the plasma input peak is crucial for a reliable kinetic analysis and blood flow estimation

  1. High-resolution pulmonary ventilation and perfusion PET/CT allows for functionally adapted intensity modulated radiotherapy in lung cancer

    International Nuclear Information System (INIS)

    Siva, Shankar; Thomas, Roshini; Callahan, Jason; Hardcastle, Nicholas; Pham, Daniel; Kron, Tomas; Hicks, Rodney J.; MacManus, Michael P.; Ball, David L.; Hofman, Michael S.

    2015-01-01

    Background and purpose: To assess the utility of functional lung avoidance using IMRT informed by four-dimensional (4D) ventilation/perfusion (V/Q) PET/CT. Materials and methods: In a prospective clinical trial, patients with non-small cell lung cancer (NSCLC) underwent 4D-V/Q PET/CT scanning before 60 Gy of definitive chemoradiation. Both “highly perfused” (HPLung) and “highly ventilated” (HVLung) lung volumes were delineated using a 70th centile SUV threshold, and a “ventilated lung volume” (VLung) was created using a 50th centile SUV threshold. For each patient four IMRT plans were created, optimised to the anatomical lung, HPLung, HVLung and VLung volumes, respectively. Improvements in functional dose volumetrics when optimising to functional volumes were assessed using mean lung dose (MLD), V5, V10, V20, V30, V40, V50 and V60 parameters. Results: The study cohort consisted of 20 patients with 80 IMRT plans. Plans optimised to HPLung resulted in a significant reduction of functional MLD by a mean of 13.0% (1.7 Gy), p = 0.02. Functional V5, V10 and V20 were improved by 13.2%, 7.3% and 3.8% respectively (p-values < 0.04). There was no significant sparing of dose to functional lung when adapting to VLung or HVLung. Plan quality was highly consistent with a mean PTV D95 and D5 ranging from 60.8 Gy to 61.0 Gy and 63.4 Gy to 64.5 Gy, respectively, and mean conformity and heterogeneity index ranging from 1.11 to 1.17 and 0.94 to 0.95, respectively. Conclusion: IMRT plans adapted to perfused but not ventilated lung on 4D-V/Q PET/CT allowed for reduced dose to functional lung whilst maintaining consistent plan quality

  2. ¹⁸F-FDG PET metabolic parameters and MRI perfusion and diffusion parameters in hepatocellular carcinoma: a preliminary study.

    Directory of Open Access Journals (Sweden)

    Sung Jun Ahn

    Full Text Available OBJECTIVES: Glucose metabolism, perfusion, and water diffusion may have a relationship or affect each other in the same tumor. The understanding of their relationship could expand the knowledge of tumor characteristics and contribute to the field of oncologic imaging. The purpose of this study was to evaluate the relationships between metabolism, vasculature and cellularity of advanced hepatocellular carcinoma (HCC, using multimodality imaging such as ¹⁸F-FDG positron emission tomography (PET, dynamic contrast enhanced (DCE-MRI, and diffusion weighted imaging(DWI. MATERIALS AND METHODS: Twenty-one patients with advanced HCC underwent ¹⁸F-FDG PET, DCE-MRI, and DWI before treatment. Maximum standard uptake values (SUV(max from ¹⁸F-FDG-PET, variables of the volume transfer constant (K(trans from DCE-MRI and apparent diffusion coefficient (ADC from DWI were obtained for the tumor and their relationships were examined by Spearman's correlation analysis. The influence of portal vein thrombosis on SUV(max and variables of K(trans and ADC was evaluated by Mann-Whitney test. RESULTS: SUV(max showed significant negative correlation with K(trans(max (ρ = -0.622, p = 0.002. However, variables of ADC showed no relationship with variables of K(trans or SUV(max (p>0.05. Whether portal vein thrombosis was present or not did not influence the SUV max and variables of ADC and K(trans (p>0.05. CONCLUSION: In this study, SUV was shown to be correlated with K(trans in advanced HCCs; the higher the glucose metabolism a tumor had, the lower the perfusion it had, which might help in guiding target therapy.

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

    International Nuclear Information System (INIS)

    Campisi, Roxana; Aramayo, Natalia; Osorio, Amilcar

    2010-01-01

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

  4. Regional cerebral perfusion measurements: a comparative study of xenon-enhanced CT and C15O2 build-up using dynamic PET

    International Nuclear Information System (INIS)

    St Lawrence, K.S.; Bews, J.; Dunscombe, P.B.

    1992-01-01

    Regional cerebral perfusion can be determined by monitoring the uptake of a diffusable tracer concurrently in cerebral tissue and arterial blood. Two techniques based on this methodology are xenon-enhanced computed tomography (Xe CT) and C 15 O 2 build-up using dynamic positron emission tomography (C 15 O 2 PET). Serial images are used by both Xe CT and C 15 O 2 PET to characterize the uptake of the tracer in cerebral tissue. The noise present in these images will reduce the precision of the perfusion measurements obtained by either technique. Using Monte Carlo type computer simulations, the precision of the two techniques as a function of image noise has been examined. On the basis of their results, they conclude that the precision of the Xe CT technique is comparable to the precision of C 15 O 2 PET when realistic clinical protocols are employed for both. (author)

  5. 13N-ammonia myocardial perfusion imaging with a PET/CT scanner: impact on clinical decision making and cost-effectiveness

    International Nuclear Information System (INIS)

    Siegrist, Patrick T.; Husmann, Lars; Knabenhans, Martina; Gaemperli, Oliver; Valenta, Ines; Hoefflinghaus, Tobias; Scheffel, Hans; Stolzmann, Paul; Alkadhi, Hatem; Kaufmann, Philipp A.

    2008-01-01

    The purpose of the study is to determine the impact of 13 N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI) on clinical decision making and its cost-effectiveness. One hundred consecutive patients (28 women, 72 men; mean age 60.9 ± 12.0 years; range 24-85 years) underwent 13 N-ammonia PET scanning (and computed tomography, used only for attenuation correction) to assess myocardial perfusion in patients with known (n = 79) or suspected (n = 8) coronary artery disease (CAD), or for suspected small-vessel disease (SVD; n = 13). Before PET, the referring physician was asked to determine patient treatment if PET would not be available. Four weeks later, PET patient management was reassessed for each patient individually. Before PET management strategies would have been: diagnostic angiography (62 of 100 patients), diagnostic angiography and percutaneous coronary intervention (PCI; 6 of 100), coronary artery bypass grafting (CABG; 3 of 100), transplantation (1 of 100), or conservative medical treatment (28 of 100). After PET scanning, treatment strategies were altered in 78 patients leading to: diagnostic angiography (0 of 100), PCI (20 of 100), CABG (3 of 100), transplantation (1 of 100), or conservative medical treatment (76 of 100). Patient management followed the recommendations of PET findings in 97% of the cases. Cost-effectiveness analysis revealed lower costs of EUR206/patient as a result of PET scanning. In a population with a high prevalence of known CAD, PET is cost-effective and has an important impact on patient management. (orig.)

  6. Determinants of the response of left ventricular ejection fraction to vasodilator stress in electrocardiographically gated {sup 82}rubidium myocardial perfusion PET

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Tracy L.Y.; Merrill, Jennifer; Bengel, Frank M. [Johns Hopkins University, Department of Radiology and Radiological Sciences, Division of Nuclear Medicine, Baltimore, MD (United States); Volokh, Lana [GE Healthcare, Haifa (Israel)

    2008-02-15

    Myocardial perfusion imaging with {sup 82}Rb PET allows for ECG-gated studies to be obtained early after radiotracer injection, capturing ventricular function close to peak pharmacologic action of dipyridamole. This is different from gated SPECT and may potentially provide additional diagnostic information. We sought to identify potential correlates of the PET-derived ejection fraction response to vasodilator stress. One hundred ten consecutive patients undergoing {sup 82}Rb PET myocardial perfusion imaging during evaluation for coronary artery disease were included. Using a GE Discovery STRx PET-CT scanner, ECG-gated images (eight bins) were obtained at rest and 4 min after dipyridamole infusion, 90 s after infusion of 1,480-2,220 MBq of {sup 82}Rb. Summed rest, stress, and difference scores (SRS, SSS, and SDS) were determined using a five-point scoring system and 20-segment model. Ejection fraction was calculated using automated QGS software. Significant reversibility (SDS {>=} 4) was found in 23 patients (21%). Mean LVEF in all patients was 47 {+-} 13% at rest and 53 {+-} 13% during dipyridamole. LVEF increased in 89 patients, and decreased in 17 patients during vasodilation. The change in LVEF was inversely correlated with SDS (r = -0.26; p = 0.007). Additionally, it was inversely correlated with resting LVEF (r = -0.20; p = 0.03) and SSS (r = -0.25; p = 0.009). No significant correlations were observed with SRS, heart rate, blood pressure, age, hypertension, hypercholesterolemia, or pretest likelihood of disease. At multivariate regression analysis, SDS was an independent predictor of the change in LVEF. Gated {sup 82}Rb PET during pharmacologic stress allows for assessment of the functional response to vasodilation. The magnitude of LVEF increase is determined by stress perfusion/reversible perfusion defects. Functional response to hyperemia may thus be incorporated in future evaluations of diagnostic and prognostic algorithms based on {sup 82}Rb PET. (orig.)

  7. The preliminary study of the blood perfusion and ammonia metabolism of pituitary using dynamic 13N-NH3 PET imaging

    International Nuclear Information System (INIS)

    Zhang Xiangsong; Tang Anwu; Qiao Suixian; Chen Liguang; Luo Yaowu; Liu Bin; Xu Weiping

    2002-01-01

    Objective: To preliminarily study the blood perfusion and ammonia metabolism of pituitary using dynamic 13 N-NH 3 PET imaging. Methods: 13 N-NH 3 PET imaging was performed on 21 subjects without pituitary diseases, 6 of them underwent dynamic PET imaging, and 8 of them underwent brain MRI in addition to PET. PET images were registered with MRI. Results: The pituitary could be clearly seen in 13 N-NH 3 PET images, and being confirmed by PET/MRI image fusion. The size of pituitary was (1.07 +- 0.17) cm x (1.09 +- 0.15) cm x (1.14 +- 0.17) cm, the standard uptake value (SUV) was 3.84 +- 1.75, and the radioactivity ratio of pituitary to thalamus was 1.35 +- 0.63. Pituitary image was seen at 10 s after the internal carotid was seen in dynamic 13 N-NH 3 PET imaging. 13 N-NH 3 was retained in pituitary, and was hardly cleaned out within 20 min. The radioactivity ratio of pituitary to internal carotid was 0.75 +- 0.13 when the radioactivity of internal carotid was at its highest level. Conclusions: The blood flow and ammonia metabolism of pituitary can be observed with dynamic 13 N-NH 3 PET imaging. Ammonia is highly extracted by pituitary, and metabolized in pituitary cells

  8. Correlation of perfusion MRI and 18F-FDG PET imaging biomarkers for monitoring regorafenib therapy in experimental colon carcinomas with immunohistochemical validation.

    Directory of Open Access Journals (Sweden)

    Ralf S Eschbach

    Full Text Available To investigate a multimodal, multiparametric perfusion MRI / 18F-fluoro-deoxyglucose-(18F-FDG-PET imaging protocol for monitoring regorafenib therapy effects on experimental colorectal adenocarcinomas in rats with immunohistochemical validation.Human colorectal adenocarcinoma xenografts (HT-29 were implanted subcutaneously in n = 17 (n = 10 therapy group; n = 7 control group female athymic nude rats (Hsd:RH-Foxn1rnu. Animals were imaged at baseline and after a one-week daily treatment protocol with regorafenib (10 mg/kg bodyweight using a multimodal, multiparametric perfusion MRI/18F-FDG-PET imaging protocol. In perfusion MRI, quantitative parameters of plasma flow (PF, mL/100 mL/min, plasma volume (PV, % and endothelial permeability-surface area product (PS, mL/100 mL/min were calculated. In 18F-FDG-PET, tumor-to-background-ratio (TTB was calculated. Perfusion MRI parameters were correlated with TTB and immunohistochemical assessments of tumor microvascular density (CD-31 and cell proliferation (Ki-67.Regorafenib significantly (p<0.01 suppressed PF (81.1±7.5 to 50.6±16.0 mL/100mL/min, PV (12.1±3.6 to 7.5±1.6% and PS (13.6±3.2 to 7.9±2.3 mL/100mL/min as well as TTB (3.4±0.6 to 1.9±1.1 between baseline and day 7. Immunohistochemistry revealed significantly (p<0.03 lower tumor microvascular density (CD-31, 7.0±2.4 vs. 16.1±5.9 and tumor cell proliferation (Ki-67, 434.0 ± 62.9 vs. 663.0 ± 98.3 in the therapy group. Perfusion MRI parameters ΔPF, ΔPV and ΔPS showed strong and significant (r = 0.67-0.78; p<0.01 correlations to the PET parameter ΔTTB and significant correlations (r = 0.57-0.67; p<0.03 to immunohistochemical Ki-67 as well as to CD-31-stainings (r = 0.49-0.55; p<0.05.A multimodal, multiparametric perfusion MRI/PET imaging protocol allowed for non-invasive monitoring of regorafenib therapy effects on experimental colorectal adenocarcinomas in vivo with significant correlations between perfusion MRI parameters and 18F-FDG-PET

  9. Quantification of myocardial blood flow with dynamic perfusion 3.0 Tesla MRI: Validation with (15) O-water PET.

    Science.gov (United States)

    Tomiyama, Yuuki; Manabe, Osamu; Oyama-Manabe, Noriko; Naya, Masanao; Sugimori, Hiroyuki; Hirata, Kenji; Mori, Yuki; Tsutsui, Hiroyuki; Kudo, Kohsuke; Tamaki, Nagara; Katoh, Chietsugu

    2015-09-01

    To develop and validate a method for quantifying myocardial blood flow (MBF) using dynamic perfusion magnetic resonance imaging (MBFMRI ) at 3.0 Tesla (T) and compare the findings with those of (15) O-water positron emission tomography (MBFPET ). Twenty healthy male volunteers underwent magnetic resonance imaging (MRI) and (15) O-water positron emission tomography (PET) at rest and during adenosine triphosphate infusion. The single-tissue compartment model was used to estimate the inflow rate constant (K1). We estimated the extraction fraction of Gd-DTPA using K1 and MBF values obtained from (15) O-water PET for the first 10 subjects. For validation, we calculated MBFMRI values for the remaining 10 subjects and compared them with the MBFPET values. In addition, we compared MBFMRI values of 10 patients with coronary artery disease with those of healthy subjects. The mean resting and stress MBFMRI values were 0.76 ± 0.10 and 3.04 ± 0.82 mL/min/g, respectively, and showed excellent correlation with the mean MBFPET values (r = 0.96, P < 0.01). The mean stress MBFMRI value was significantly lower for the patients (1.92 ± 0.37) than for the healthy subjects (P < 0.001). The use of dynamic perfusion MRI at 3T is useful for estimating MBF and can be applied for patients with coronary artery disease. © 2014 Wiley Periodicals, Inc.

  10. Novel synthesis and initial preclinical evaluation of (18)F-[FDG] labeled rhodamine: a potential PET myocardial perfusion imaging agent.

    Science.gov (United States)

    AlJammaz, Ibrahim; Al-Otaibi, Basim; AlHindas, Hussein; Okarvi, Subhani M

    2015-10-01

    Myocardial perfusion imaging is one of the most commonly performed investigations in nuclear medicine studies. Due to the clinical importance of [(18)F]-fluoro-2-deoxy-D-glucose ([(18)F]-FDG) and its availability in almost every PET center, a new radiofluorinated [(18)F]-FDG-rhodamine conjugate was synthesized using [(18)F]-FDG as a prosthetic group. In a convenient and simple one-step radiosynthesis, [(18)F]-FDG-rhodamine conjugate was prepared in quantitative radiochemical yields, with total synthesis time of nearly 20 min and radiochemical purity of greater than 98%, without the need for HPLC purification, which make these approaches amenable for automation. Biodistribution studies in normal rats at 60 min post-injection demonstrated a high uptake in the heart (>11% ID/g) and favorable pharmacokinetics. Additionally, [(18)F]-FDG-rhodamine showed an extraction value of 27.63%±5.12% in rat hearts. These results demonstrate that [(18)F]-FDG-rhodamine conjugate may be useful as an imaging agent for the positron emission tomography evaluation of myocardial perfusion. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Utility of adenosine PET (perfusion/metabolic) imaging in patients with acute myocardial infarction following thrombolytic therapy

    International Nuclear Information System (INIS)

    Gupta, N.C.; Esterbrooks, D.M.; Shiue, C.; Mohiuddin, S.; Hilleman, D.; Frick, M.P.

    1990-01-01

    This paper evaluates the diagnostic role of adenosine (AI) proton emission tomography (PET) in patients with acute myocardial infarction (AMI) and thrombolytic therapy using adenosine as a coronary vasodilator. The authors performed rest/stress myocardial perfusion and metabolic image studies (using N-13 NH 3 and F-18 FDG) in 14 patients within 1 week after thrombolytic therapy for an AMI. AI (140 μg/kg/min for 6 minutes) used a pharmacologic stressor resulted only in transient and well-tolerated side effects. Sensitivities and specificities of the rest/stress perfusion imaging and coronary angiographic results (performed within 1 week) are as follows: LAD, 87.5% and 83.3%; LCX, 100% and 100%; RCA, 100% and 83.3%; and overall, 94.4% and 91.3%. Resting NH 3 /FDG mismatch (hypoperfused viable myocardium) was seen in 2/14 patients in infarct-related (IR) and 3/14 patients in non-IR stenoses

  12. Sex differences in absolute myocardial perfusion. Non-invasive H2(15)O-PET in young healthy adults.

    Science.gov (United States)

    Range, Felix T; Kies, Peter; Schäfers, Klaus P; Breithardt, Günter; Schober, Otmar; Wichter, Thomas; Schäfers, Michael A

    2016-09-26

    To investigate sex differences in myocardial perfusion especially in healthy individuals since former studies are rare and findings are controversial. Participants, methods: 26 subjects were enrolled: 16 healthy women (age: 34 ±7 years) were compared with 10 healthy men (age: 34 ± 3 years; p = ns). Myocardial blood flow (MBF) and coronary vascular resistance (CVR) were quantified at rest, during adenosine infusion and cold-pressor-testing, using positron emission tomography and radioactive-labelled water (H2(15)O-PET). Women showed higher MBF than men at rest (1.10 ± 0.18 vs. 0.85 ± 0.20 ml/min/ml; p = 0.003) and cold-stress (1.39 ± 0.38 vs. 1.06 ± 0.28 ml/min/ml; p = 0.026). Corrected for rate-pressure-product, baseline findings maintained significance (1.41 ± 0.33 vs. 1.16 ± 0.19 ml/min/ml; p = 0.024). CVR was lower in women at baseline (81 ± 14 vs. 107 ± 22 mmHg*ml(-1)*min*ml; p = 0.006) and during cold-pressor-testing (71 ± 17 vs. 91 ± 20 mmHg*ml(-1)*min*ml; p = 0.013). Under adenosine neither maximal MBF (4.06 ± 1.0 vs. 3.91 ± 0.88 ml/min/ml; p = ns) nor coronary flow reserve (3.07 ± 1.12 vs. 3.44 ± 0.92; p = ns) nor CVR (24 ± 8 vs. 24 ± 6 mmHg*ml(-1)*min*ml; p = ns) showed sex-related differences. Women show higher myocardial perfusion and lower coronary vascular resistance than men in physiologic states. Maximum perfusion and vasodilation under adenosine are not sex-specific.

  13. High-resolution imaging of pulmonary ventilation and perfusion with 68Ga-VQ respiratory gated (4-D) PET/CT

    International Nuclear Information System (INIS)

    Callahan, Jason; Hofman, Michael S.; Siva, Shankar; Kron, Tomas; Schneider, Michal E.; Binns, David; Eu, Peter; Hicks, Rodney J.

    2014-01-01

    Our group has previously reported on the use of 68 Ga-ventilation/perfusion (VQ) PET/CT scanning for the diagnosis of pulmonary embolism. We describe here the acquisition methodology for 68 Ga-VQ respiratory gated (4-D) PET/CT and the effects of respiratory motion on image coregistration in VQ scanning. A prospective study was performed in 15 patients with non-small-cell lung cancer. 4-D PET and 4-D CT images were acquired using an infrared marker on the patient's abdomen as a surrogate for breathing motion following inhalation of Galligas and intravenous administration of 68 Ga-macroaggregated albumin. Images were reconstructed with phase-matched attenuation correction. The lungs were contoured on CT and PET VQ images during free-breathing (FB) and at maximum inspiration (Insp) and expiration (Exp). The similarity between PET and CT volumes was measured using the Dice coefficient (DC) comparing the following groups; (1) FB-PET/CT, (2) InspPET/InspCT, (3) ExpPET/Exp CT, and (4) FB-PET/AveCT. A repeated measures one-way ANOVA with multiple comparison Tukey tests were performed to evaluate any difference between the groups. Diaphragmatic motion in the superior-inferior direction on the 4-D CT scan was also measured. 4-D VQ scanning was successful in all patients without additional acquisition time compared to the nongated technique. The highest volume overlap was between ExpPET and ExpCT and between FB-PET and AveCT with a DC of 0.82 and 0.80 for ventilation and perfusion, respectively. This was significantly better than the DC comparing the other groups (0.78-0.79, p 68 Ga-VQ 4-D PET/CT is feasible and the blurring caused by respiratory motion is well corrected with 4-D acquisition, which principally reduces artefact at the lung bases. The images with the highest spatial overlap were the combined expiration phase or FB PET and average CT. With higher resolution than SPECT/CT, the PET/CT technique has a broad range of potential clinical applications including

  14. Characterization of glial tumors in PET/CT 18F-dopa and in perfusion MRI

    International Nuclear Information System (INIS)

    Nioche, Christophe

    2011-01-01

    MRI provides morphological information about a tumour, as well as information regarding its micro-vascularisation of the tumour. In PET/CT, accumulation of 18 F-Dopa in tumour cells results from the metabolic activity greater than that of healthy tissues.We studied 28 gliomas for which we analysed data from MRI and PET/CT. A registration method has been developed to combine information from both PET and MRI and to extract volumes of interest consistent with the information included in the two modalities. In these volumes, the tumour compartment and normal tissue compartment were identified using a Gaussian mixture model. Parameters from PET or MRI data were then calculated in these compartments. ROC analyses combined with linear discriminant analyses were used to assess whether joint observation of standardized uptake value (SUVmax) and relative Cerebral Blood Volume (rCBV) or of relative rk1 and rCBV could distinguish between low grade and high grade tumours. We found that using this joint analysis, 82% of high-grade tumors and 70% of low grade tumors were correctly classified (AUC of 0.88 for [SUVmax, rCBV] and of 0.92 for [rk1, rCBV]). Considering the combined information from [SUVmax, rCBV], the sensitivity for detecting high-grade tumors was 95% with a specificity of 60%. The negative predictive value was 52% for a positive predictive value of 95%. Similarly, considering the combined information from [rk1, rCBV], we also obtain a specificity of 60% associated with a 95% sensitivity for detecting high-grade tumors, with a negative predictive value of 60% and positive predictive value of 95%. Our work shows that joint analysis of information from microvascular and metabolic is possible by combining PET and MR imaging data. However, we found that, in our patient population, the microvascular information obtained through MR did not achieve better discrimination than the metabolic information derived from PET only. (author)

  15. Story of rubidium-82 and advantages for myocardial perfusion PET imaging

    Directory of Open Access Journals (Sweden)

    Jean-Francois eChatal

    2015-09-01

    Full Text Available Rubidium-82 has a long story, starting in 1954. After preclinical studies in dogs showing that myocardial uptake of this radionuclide was directly proportional to myocardial blood flow, clinical studies were performed in the 80s leading to an approval in the USA in 1989. From that time thousands of patients have been tested and their results have been reported in 3 meta-analyses. Pooled patient-based sensitivity and specificity were respectively 0.91 and 0.90. By comparison with 99mTc-SPECT, 82Rb-PET had a much better diagnostic accuracy, especially in obese patients with BMI (Body Mass Index ≥30 kg/m2 (85% versus 67% with SPECT and in women with large breasts. A great advantage of 82Rb-PET is its capacity to accurately quantify myocardial blood flow. Quite importantly it has been recently shown that coronary flow reserve is associated with adverse cardiovascular events independently of luminal angiographic severity. Moreover coronary flow reserve is a functional parameter particularly useful in the estimate of microvascular dysfunction such as in diabetes mellitus. Due to the very short half-life of rubidium-82, the effective dose calculated for a rest/stress test is roughly equivalent to the annual natural exposure and even less when stress-only is performed with a low activity compatible with a good image quality with the last generation 3D PET scanners.There is still some debate on the relative advantages of 82Rb-PET with regard to 99mTc-SPECT. For the last ten years, great technological advances substantially improved performances of SPECT with its accuracy getting closer to this of 82Rb/PET. Currently the main advantages of PET are its capacity to accurately quantify myocardial blood flow and to deliver a low radiation exposure.

  16. Multimodality functional imaging of spontaneous canine tumors using 64Cu-ATSM and 18FDG PET/CT and dynamic contrast enhanced perfusion CT

    International Nuclear Information System (INIS)

    Hansen, Anders E.; Kristensen, Annemarie T.; Law, Ian; McEvoy, Fintan J.; Kjær, Andreas; Engelholm, Svend A.

    2012-01-01

    Purpose: To compare the distribution and uptake of the hypoxia tracer 64 Cu-diacetyl-bis(N 4 -methylthiosemicarbazone) ( 64 Cu-ATSM) PET/CT, FDG PET/CT and dynamic contrast enhanced perfusion CT (DCE-pCT) in spontaneous canine tumors. In addition 64 Cu-ATSM distribution over time was evaluated. Methods and materials: Nine spontaneous cancer-bearing dogs were prospectively enrolled. FDG (1 h pi.) and 64 Cu-ATSM (3 and 24 h pi.) PET/CT were performed over three consecutive days. DCE-pCT was performed on day 2. Tumor uptake of FDG and 64 Cu-ATSM was assessed semi-quantitatively and the distribution of FDG, 64 Cu-ATSM and CT perfusion parameters correlated. Results: 64 Cu-ATSM distribution on scans performed 24 h apart displayed moderate to strong correlation; however, temporal changes were observed. The spatial distribution pattern of 64 Cu-ATSM between scans was moderately to strongly positively correlated to FDG, whereas the correlation of CT perfusion parameters to FDG and to 64 Cu-ATSM yielded more varying results. Conclusions: 64 Cu-ATSM uptake was positively correlated to FDG. 64 Cu-ATSM was found to be relatively stable between PET scans performed at different time points, important temporal changes were however observed in hypo-perfused regions. These findings potentially indicate that prolonged uptake periods for 64 Cu-ATSM imaging may be needed. Although a moderate to strong correlation between 64 Cu-ATSM and FDG PET/CT is observed, the two tracers provide different biological information with an overlapping spatial distribution.

  17. Perfusion CT compared to H{sub 2}{sup 15}O/O{sup 15}O PET in patients with chronic cervical carotid artery occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, Amita; Chien, Jeffrey D.; Dillon, William P.; Wintermark, Max [University of California, San Francisco, Department of Radiology, Neuroradiology Section, San Francisco, CA (United States); Smith, Wade S. [University of California, Department of Neurology, San Francisco, CA (United States); Powers, William J. [University of North Carolina, Department of Neurology, Chapel Hill, NC (United States); Cianfoni, Alessandro [Catholic University of Sacred Heart, Department of Bioimages and Radiological Sciences, Rome (Italy); Videen, Tom [Washington University School of Medicine, Departments of Neurology and Radiology, St. Louis, MO (United States); Lawton, Michael T. [University of California, San Francisco, CA (United States). Department of Neurosurgery; Finley, Bruce [Northern California PET Imaging Center, Sacramento, CA (United States)

    2008-09-15

    The purpose of this study was to compare the results of perfusion computed tomography (PCT) with those of {sup 15}O{sub 2}/H{sub 2}{sup 15}O positron emission tomography (PET) in a subset of Carotid Occlusion Surgery Study (COSS) patients. Six patients enrolled in the COSS underwent a standard-of-care PCT in addition to the {sup 15}O{sub 2}/H{sub 2}{sup 15}O PET study used for selection for extracranial-intracranial bypass surgery. PCT and PET studies were coregistered and then processed separately by different radiologists. Relative measurement of cerebral blood flow (CBF) and oxygen extraction fraction (OEF) were calculated from PET. PCT datasets were processed using different arterial input functions (AIF). Relative PCT and PET CBF values from matching regions of interest were compared using linear regression model to determine the most appropriate arterial input function for PCT. Also, PCT measurements using the most accurate AIF were evaluated for linear regression with respect to relative PET OEF values. The most accurate PCT relative CBF maps with respect to the gold standard PET CBF were obtained when CBF values for each arterial territory are calculated using a dedicated AIF for each territory (R{sup 2}=0.796, p<0.001). PCT mean transit time (MTT) is the parameter that showed the best correlation with the count-based PET OEF ratios (R{sup 2}=0.590, p<0.001). PCT relative CBF compares favorably to PET relative CBF in patients with chronic carotid occlusion when processed using a dedicated AIF for each territory. The PCT MTT parameter correlated best with PET relative OEF. (orig.)

  18. Static Myocardial Perfusion Imaging using denoised dynamic Rb-82 PET/CT scans

    DEFF Research Database (Denmark)

    Petersen, Maiken N.M.; Hoff, Camilla; Harms, Hans

    (R2=0.89), TPD (stress, R2=0.99; rest, R2=0.97) and Extent (stress, R2=0.99; rest, R2=0.96) were likewise excellent. For Hotelling 3D, correlations were slightly lower than for HYPR-LR: relative perfusion (rest, y=1.016x-0.131, R2=0.95; stress, y=0.982x+3.165, R2=0.87), SSS (R2=0.90), SRS (R2...

  19. Combined evaluation of regional coronary artery calcium and myocardial perfusion by {sup 82}Rb PET/CT in the identification of obstructive coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Zampella, Emilia; Assante, Roberta; Nappi, Carmela; Mainolfi, Ciro Gabriele; Green, Roberta; Cantoni, Valeria; Klain, Michele; Cuocolo, Alberto [University Federico II, Department of Advanced Biomedical Sciences, Naples (Italy); Acampa, Wanda [University Federico II, Department of Advanced Biomedical Sciences, Naples (Italy); National Council of Research, Institute of Biostructure and Bioimaging, Naples (Italy); Gaudieri, Valeria; Panico, Mariarosaria [National Council of Research, Institute of Biostructure and Bioimaging, Naples (Italy); Petretta, Mario [University Federico II, Department of Translational Medical Sciences, Naples (Italy); Slomka, Piotr J. [Cedars-Sinai Medical Center, Department of Medicine, Los Angeles, CA (United States); UCLA, David Geffen School of Medicine, Los Angeles, CA (United States)

    2018-04-15

    Cardiac imaging with PET/CT allows measurement of coronary artery calcium (CAC), myocardial perfusion and coronary vascular function. We investigated whether the combined assessment of regional CAC score, ischemic total perfusion deficit (ITPD) and quantitative coronary vascular function would further improve the diagnostic accuracy of PET/CT in predicting obstructive coronary artery disease (CAD). We analyzed 113 patients with suspected CAD referred to {sup 82}Rb PET/CT myocardial perfusion imaging with available coronary angiographic data. Obstructive CAD was defined as ≥75% stenosis. The receiver operating characteristic area under curve (AUC) was applied to evaluate the ability of CAC score, ITPD, hyperemic myocardial blood flow (MBF) and coronary flow reserve (CFR) to identify CAD. Vessels with obstructive CAD (71 vessels) had higher ITPD (4.6 ± 6.2 vs. 0.6 ± 1.3) and lower hyperemic MBF (1.01 ± 0.5 vs. 1.75 ± 0.6 ml/min/g) and CFR (1.56 ± 0.6 vs. 2.38 ± 0.7; all p < 0.001) than those without. In prediction of per-vessel CAD, the AUCs for the models including CAC/ITPD/hyperemic MBF (0.869) and CAC/ITPD/CFR (0.875) were higher (both p < 0.01) than for the model including CAC/ITPD (0.790). Compared with CAC/ITPD, continuous net reclassification improvement was 0.69 (95% bootstrap confidence interval, CI, 0.365-1.088) for the CAC/ITPD/hyperemic MBF model and 0.99 (95% bootstrap CI 0.64-1.26) for the CAC/ITPD/CFR model. Hyperemic MBF and CFR provide incremental information about the presence of CAD over CAC score and perfusion imaging parameters. The combined use of CAC, myocardial perfusion imaging and quantitative coronary vascular function in may help predict more accurately the presence of obstructive CAD. (orig.)

  20. Quantitative cerebral H215O perfusion PET without arterial blood sampling, a method based on washout rate

    International Nuclear Information System (INIS)

    Treyer, Valerie; Jobin, Mathieu; Burger, Cyrill; Buck, Alfred; Teneggi, Vincenzo

    2003-01-01

    The quantitative determination of regional cerebral blood flow (rCBF) is important in certain clinical and research applications. The disadvantage of most quantitative methods using H 2 15 O positron emission tomography (PET) is the need for arterial blood sampling. In this study a new non-invasive method for rCBF quantification was evaluated. The method is based on the washout rate of H 2 15 O following intravenous injection. All results were obtained with Alpert's method, which yields maps of the washin parameter K 1 (rCBF K1 ) and the washout parameter k 2 (rCBF k2 ). Maps of rCBF K1 were computed with measured arterial input curves. Maps of rCBF k2* were calculated with a standard input curve which was the mean of eight individual input curves. The mean of grey matter rCBF k2* (CBF k2* ) was then compared with the mean of rCBF K1 (CBF K1 ) in ten healthy volunteer smokers who underwent two PET sessions on day 1 and day 3. Each session consisted of three serial H 2 15 O scans. Reproducibility was analysed using the rCBF difference scan 3-scan 2 in each session. The perfusion reserve (PR = rCBF acetazolamide -rCBF baseline ) following acetazolamide challenge was calculated with rCBF k2* (PR k2* ) and rCBF K1 (PR K1 ) in ten patients with cerebrovascular disease. The difference CBF k2* -CBF K1 was 5.90±8.12 ml/min/100 ml (mean±SD, n=55). The SD of the scan 3-scan 1 difference was 6.1% for rCBF k2* and rCBF K1 , demonstrating a high reproducibility. Perfusion reserve values determined with rCBF K1 and rCBF k2* were in high agreement (difference PR k2* -PR K1 =-6.5±10.4%, PR expressed in percentage increase from baseline). In conclusion, a new non-invasive method for the quantitative determination of rCBF is presented. The method is in good agreement with Alpert's original method and the reproducibility is high. It does not require arterial blood sampling, yields quantitative voxel-by-voxel maps of rCBF, and is computationally efficient and easy to implement

  1. Assessment of intratumor hypoxia by integrated 18F-FDG PET / perfusion CT in a liver tumor model.

    Directory of Open Access Journals (Sweden)

    Yong Wang

    Full Text Available Hypoxia in solid tumors occurs when metabolic demands in tumor cells surpass the delivery of oxygenated blood. We hypothesize that the 18F-fluorodeoxyglucose (18F-FDG metabolism and tumor blood flow mismatch would correlate with tumor hypoxia.Liver perfusion computed tomography (CT and 18F-FDG positron emission tomography (PET imaging were performed in twelve rabbit livers implanted with VX2 carcinoma. Under CT guidance, a fiber optic probe was inserted into the tumor to measure the partial pressure of oxygen (pO2. Tumor blood flow (BF and standardized uptake value (SUV were measured to calculate flow-metabolism ratio (FMR. Tumor hypoxia was further identified using pimonidazole immunohistochemical staining. Pearson correlation analysis was performed to determine the correlation between the imaging parameters and pO2 and pimonidazole staining.Weak correlations were found between blood volume (BV and pO2 level (r = 0.425, P = 0.004, SUV and pO2 (r = -0.394, P = 0.007, FMR and pimonidazole staining score (r = -0.388, P = 0.031. However, there was stronger correlation between tumor FMR and pO2 level (r = 0.557, P < 0.001.FMR correlated with tumor oxygenation and pimonidazole staining suggesting it may be a potential hypoxic imaging marker in liver tumor.

  2. Feasibility of perfusion CT technique integrated into conventional {sup 18}FDG/PET-CT studies in lung cancer patients: clinical staging and functional information in a single study

    Energy Technology Data Exchange (ETDEWEB)

    Ippolito, Davide; Capraro, Cristina; Sironi, Sandro [University of Milano-Bicocca, School of Medicine, Milan (Italy); University of Milano-Bicocca, Department of Diagnostic Radiology, H.S. Gerardo Monza, Via Pergolesi 11, Monza, Milan (Italy); Guerra, Luca [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine and PET Unit - Molecular Bioimaging Centre, Monza (Italy); De Ponti, Elena [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Medical Physics, Monza (Italy); Messa, Cristina [University of Milano-Bicocca, School of Medicine, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine and PET Unit - Molecular Bioimaging Centre, Monza (Italy); Tecnomed Foundation, University of Milano-Bicocca, Institute for Bioimaging and Molecular Physiology, National Research Council, Milan (Italy)

    2013-02-15

    To assess the additional functional vascular information and the relationship between perfusion measurements and glucose metabolism (SUVmax) obtained by including a perfusion CT study in a whole-body contrast-enhanced PET/CT protocol in primary lung cancer lesions. Enrolled in this prospective study were 34 consecutive patients with a biopsy-proven diagnosis of lung cancer who were referred for contrast-enhanced PET/CT staging. This prospective study was approved by our institutional review board, and informed consent was obtained from all patients. Perfusion CT was performed with the following parameters: 80 kV, 200 mAs, 30 scans during intravenous injection of 50 ml contrast agent, flow rate 5 ml/s. Another bolus of contrast medium (3.5 ml/s, 80 ml, 60-s delay) was administered to ensure a full diagnostic contrast-enhanced CT scan for clinical staging. The perfusion CT data were used to calculate a range of tumour vascularity parameters (blood flow, blood volume and mean transit time), and tumour FDG uptake (SUVmax) was used as a metabolic indicator. Quantitative and functional parameters were compared and in relation to location, histology and tumour size. The nonparametric Kruskal-Wallis rank sum test was used for statistical analysis. A cut-off value of 3 cm was used according to the TNM classification to discriminate between T1 and T2 tumours (i.e. T1b vs. T2a). There were significant perfusion differences (lower blood volumes and higher mean transit time) between tumours with diameter >30 mm and tumours with diameter <30 mm (p < 0.05; blood volume 5.6 vs. 7.1 ml/100 g, mean transit time 8.6 vs. 3.9 s, respectively). Also there was a trend for blood flow to be lower in larger lesions (p < 0.053; blood flow 153.1 vs. 98.3 ml/100 g tissue/min). Significant inverse correlations (linear regression) were found between blood volume and SUVmax in tumours with diameter >30 mm in diameter. Perfusion CT combined with PET/CT is feasible technique that may provide

  3. Low-dose dobutamine stress gated SPET for identification of viable myocardium: comparison with stress-rest perfusion SPET and PET

    International Nuclear Information System (INIS)

    Yoshinaga, Keiichiro; Tamaki, Nagara; Katoh, Chietsugu; Kuge, Yuji; Noriyasu, Kazuyuki; Yamada, Satoshi; Ito, Yoshinori; Kohya, Tetsuro; Kitabatake, Akira; Kawai, Yuko

    2002-01-01

    The detection of viable myocardium is important for the prediction of functional recovery after revascularisation. However, a fixed perfusion defect often includes viable myocardium, and perfusion imaging then underestimates myocardial viability. We previously reported that low-dose dobutamine stress gated single-photon emission tomography (SPET) provides similar findings to dobutamine stress echocardiography in the assessment of myocardial viability. The present study investigated whether low-dose dobutamine stress gated SPET is of additional value as compared with stress-rest technetium-99m tetrofosmin SPET for the detection of myocardial viability. Standard stress-rest perfusion SPET, low-dose dobutamine stress gated SPET and fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) were studied in 23 patients (mean age 67±7.6 years) with previous myocardial infarction. Twenty-one of them were successfully studied with each technique. FDG PET viability (FDG uptake ≥50%) was employed as the gold standard. One-day stress-rest 99m Tc-tetrofosmin myocardial SPET was performed. After the resting study, gated SPET was acquired following infusion of 7.5 μg kg -1 min -1 of dobutamine. Left ventricular wall motion in 16 segments was assessed by cine mode display using a four-point scale. Myocardial viability was considered present when there was improvement by one point. Of a total of 336 segments analysed, 53 had persistent defects on stress-rest perfusion SPET. FDG viability was seen in 16 of 17 dobutamine-responsive segments, but in only 11 of 36 dobutamine non-responsive segments (P<0.01). Thus, in the segments with persistent defects, viability findings on low-dose dobutamine stress gated SPET were concordant with those on FDG PET in 77% of segments (kappa value =0.55). For the detection of FDG-viable myocardium, the combination of stress-rest perfusion SPET and low-dose dobutamine stress gated SPET achieved a better sensitivity than stress

  4. Synthesis of [18F] labeled tetraphenylphosphonium derivatives as a novel myocardial perfusion agent for PET

    International Nuclear Information System (INIS)

    Kim, Dong Yeon; Bom, Hee Seung; Min, Jung Joon; Yu, Kook Hyun

    2007-01-01

    Lipophilic cations including phosphonium salts penetrate the hydrophobic barriers of the plasma and mitochondrial membranes and accumulate in mitochondria in response to the negative inner transmembrane potentials. The development of radiolabeled phosphonium cations as a noninvasive imaging agent may serve as a new molecular 'voltage sensor' probe to investigate the role of mitochondria in the pathophysiology and diagnosis of cancer. Besides, the tetraphenylphosphonium (TPP) salts has been known to be accumulated in cancer cells as well as in cardiomyocytes especially, [18F]labeled tetraphenylphosphonium derivativesare thought to have a potential to be utilized as a novel myocardial or cancer imaging agent for PET. We have synthesized a reference compound fluoroalkyl triphenylphosphonium (n=5, 6, 7, 8) and a labeled compound, [18F]fluoroalkyl triphenylphosphonium (n=5, 6, 7, 8), which via two step nucleophilic substitution of no-carrier-added F-18 fluoride with the precurso in the presence of Kryptofix-2.2.2 and K2CO3. The reference compound fluoroalkyl triphenylphosphonium (n=5, 6, 7, 8) were synthesized in 79∼82% yield and the labeled compound were synthesized in 20∼25% yield respectively. The tetraphenylphosphonium (TPP) salts exhibited accumulation in cancer as well as heart. Therefore, [18F] radiolabeled tetraphenylphosphonium derivatives are thought to have a potential being utilized as a novel PET molecular probe for imaging cancer and myocardium. Thus, the development of [18F] radiolabeled tetraphenylphosphonium derivatives as a noninvasive imaging agent may serve as a new molecular voltage sensor probe to investigate the role of mitochondria in the diagnosis and treatment of ischemic heart disease and cancer

  5. Corrections of arterial input function for dynamic H215O PET to assess perfusion of pelvic tumours: arterial blood sampling versus image extraction

    International Nuclear Information System (INIS)

    Luedemann, L; Sreenivasa, G; Michel, R; Rosner, C; Plotkin, M; Felix, R; Wust, P; Amthauer, H

    2006-01-01

    Assessment of perfusion with 15 O-labelled water (H 2 15 O) requires measurement of the arterial input function (AIF). The arterial time activity curve (TAC) measured using the peripheral sampling scheme requires corrections for delay and dispersion. In this study, parametrizations with and without arterial spillover correction for fitting of the tissue curve are evaluated. Additionally, a completely noninvasive method for generation of the AIF from a dynamic positron emission tomography (PET) acquisition is applied to assess perfusion of pelvic tumours. This method uses a volume of interest (VOI) to extract the TAC from the femoral artery. The VOI TAC is corrected for spillover using a separate tissue TAC and for recovery by determining the recovery coefficient on a coregistered CT data set. The techniques were applied in five patients with pelvic tumours who underwent a total of 11 examinations. Delay and dispersion correction of the blood TAC without arterial spillover correction yielded in seven examinations solutions inconsistent with physiology. Correction of arterial spillover increased the fitting accuracy and yielded consistent results in all patients. Generation of an AIF from PET image data was investigated as an alternative to arterial blood sampling and was shown to have an intrinsic potential to determine the AIF noninvasively and reproducibly. The AIF extracted from a VOI in a dynamic PET scan was similar in shape to the blood AIF but yielded significantly higher tissue perfusion values (mean of 104.0 ± 52.0%) and lower partition coefficients (-31.6 ± 24.2%). The perfusion values and partition coefficients determined with the VOI technique have to be corrected in order to compare the results with those of studies using a blood AIF

  6. Pre and post operative evaluation of the perfusion reserve by acetazolamide 99mTc-HMPAO SPECT in patients with chronic occlusive cerebral arteries. A comparative study with PET

    International Nuclear Information System (INIS)

    Kuwabara, Yasuo; Ichiya, Yuichi; Sasaki, Masayuki; Akashi, Yuko; Yoshida, Tsuyoshi; Fukumura, Toshimitsu; Masuda, Kouji; Fujii, Kiyotaka; Fukui, Masashi

    1994-01-01

    We studied the pre and post-operative perfusion reserve using Diamox 99m Tc-HMPAO SPECT in 7 patients with chronic occlusive cerebral arteries and then compared the results with PET. STAMCA anastomosis was performed on 5 patients, while a carotid endarterectomy was done on 2 patients. The cerebral blood flow, the vascular response to CO 2 or Diamox, the oxygen extraction fraction and transit time (CBV/CBF) were measured by PET. In the pre-operative state, the visual evaluations for hypoperfusion area at rest agreed in 5 out of 7 patients in HMPAO SPECT and PET studies. In the remaining 2 patients, hypoperfusion areas were only detected in the PET study. The pre-operative evaluation of perfusion reserve agreed in 2 patients. In the remaining 5 patients, 3 patients showed definite positive (++) in PET and positive (+) in HMPAO SPECT, and one patient showed positive (+) in PET and negative (-) in HMPAO SPECT. The post-operative change of hypoperfusion areas well agreed in HMPAO SPECT and PET studies. However, the change of perfusion reserve was underestimated in HMPAO SPECT compared with PET. In the semiquantitative and quantitative analyses, the count rate ratios (affected/unaffected side) in HMPAO SPECT were apparently higher than those of CBF in PET. The postoperative change of the count rate ratios in HMPAO SPECT were smaller than those of CBF in PET. There was no significant correlation between the change in the ratio of the HMPAO SPECT after the administration of Diamox and the oxygen extraction fraction, and it was thus thought to be impossible to predict the areas with an increased oxygen extraction fraction. Thus, Diamox HMPAO SPECT may underestimate the areas of hypoperfusion or decrease in perfusion reserve when compared with PET. We should consider these limitations in the evaluation of pre and post operative cerebral hemodynamics. (author)

  7. Comparison of the Peripheral Reactive Hyperemia Index with Myocardial Perfusion Reserve by 82Rb PET/CT in HIV-Infected Patients

    Directory of Open Access Journals (Sweden)

    Mathilde Ørbæk

    2017-05-01

    Full Text Available After the introduction of antiretroviral therapy (ART the life expectancy of patients infected with human immunodeficiency virus (HIV is now approaching that of the general population and the importance of non-AIDS co-morbidities is increasing. Specifically, the risk of coronary artery disease (CAD seems to be higher in HIV-infected patients and an accurate risk prediction of CAD is of high importance for optimal long term treatment. In this study, we assessed the correlation of the endoPAT, which is an office-based CVD screening tool with the myocardial perfusion reserve by 82-rubidium PET/CT. We measured the reactive hyperemia index, which is a measure of the endothelial responsiveness, by the use of an endoPAT device (Itamar Medical, Caesarea, Israel in 48 ART treated HIV-infected patients with high CD 4 cell counts and viral suppression (HIV-RNA < 20 copies/mL, who had previously undergone measurement of the myocardial perfusion reserve by 82-rubidium PET/CT for study purposes. We found an inverse correlation between the reactive hyperemia index and the myocardial perfusion reserve which most likely indicates different vascular physiology. This study did not find evidence to suggest the immediate implementation of the reactive hyperemia index as a screening tool for early coronary artery disease in well-treated HIV-infected patients pending further validation in larger prospective studies.

  8. High-resolution imaging of pulmonary ventilation and perfusion with {sup 68}Ga-VQ respiratory gated (4-D) PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Callahan, Jason [Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Hofman, Michael S. [The University of Melbourne, Department of Medicine, Peter MacCallum Cancer Centre, Centre for Molecular Imaging, East Melbourne, VIC (Australia); Siva, Shankar [The University of Melbourne, Peter MacCallum Cancer Centre, Department of Radiation Oncology, East Melbourne, VIC (Australia); The University of Melbourne, Sir Peter MacCallum Department of Oncology, East Melbourne, VIC (Australia); Kron, Tomas [The University of Melbourne, Sir Peter MacCallum Department of Oncology, East Melbourne, VIC (Australia); The University of Melbourne, Peter MacCallum Cancer Centre, Department of Physical Sciences, East Melbourne, VIC (Australia); Schneider, Michal E. [Monash University, Department of Medical Imaging and Radiation Science, Clayton, VIC (Australia); Binns, David; Eu, Peter [Peter MacCallum Cancer Centre, Centre for Cancer Imaging, East Melbourne, VIC (Australia); Hicks, Rodney J. [The University of Melbourne, Sir Peter MacCallum Department of Oncology, Peter MacCallum Cancer Centre, Centre for Molecular Imaging, East Melbourne, VIC (Australia)

    2014-02-15

    Our group has previously reported on the use of {sup 68}Ga-ventilation/perfusion (VQ) PET/CT scanning for the diagnosis of pulmonary embolism. We describe here the acquisition methodology for {sup 68}Ga-VQ respiratory gated (4-D) PET/CT and the effects of respiratory motion on image coregistration in VQ scanning. A prospective study was performed in 15 patients with non-small-cell lung cancer. 4-D PET and 4-D CT images were acquired using an infrared marker on the patient's abdomen as a surrogate for breathing motion following inhalation of Galligas and intravenous administration of {sup 68}Ga-macroaggregated albumin. Images were reconstructed with phase-matched attenuation correction. The lungs were contoured on CT and PET VQ images during free-breathing (FB) and at maximum inspiration (Insp) and expiration (Exp). The similarity between PET and CT volumes was measured using the Dice coefficient (DC) comparing the following groups; (1) FB-PET/CT, (2) InspPET/InspCT, (3) ExpPET/Exp CT, and (4) FB-PET/AveCT. A repeated measures one-way ANOVA with multiple comparison Tukey tests were performed to evaluate any difference between the groups. Diaphragmatic motion in the superior-inferior direction on the 4-D CT scan was also measured. 4-D VQ scanning was successful in all patients without additional acquisition time compared to the nongated technique. The highest volume overlap was between ExpPET and ExpCT and between FB-PET and AveCT with a DC of 0.82 and 0.80 for ventilation and perfusion, respectively. This was significantly better than the DC comparing the other groups (0.78-0.79, p < 0.05). These values agreed with a visual inspection of the images with improved image coregistration around the lung bases. The diaphragmatic motion during the 4-D CT scan was highly variable with a range of 0.4-3.4 cm (SD 0.81 cm) in the right lung and 0-2.8 cm (SD 0.83 cm) in the left lung. Right-sided diaphragmatic nerve palsy was observed in 3 of 15 patients. {sup 68}Ga-VQ 4-D

  9. Accuracy and Utility of Deformable Image Registration in 68Ga 4D PET/CT Assessment of Pulmonary Perfusion Changes During and After Lung Radiation Therapy

    International Nuclear Information System (INIS)

    Hardcastle, Nicholas; Hofman, Michael S.; Hicks, Rodney J.; Callahan, Jason; Kron, Tomas; MacManus, Michael P.; Ball, David L.; Jackson, Price; Siva, Shankar

    2015-01-01

    Purpose: Measuring changes in lung perfusion resulting from radiation therapy dose requires registration of the functional imaging to the radiation therapy treatment planning scan. This study investigates registration accuracy and utility for positron emission tomography (PET)/computed tomography (CT) perfusion imaging in radiation therapy for non–small cell lung cancer. Methods: 68 Ga 4-dimensional PET/CT ventilation-perfusion imaging was performed before, during, and after radiation therapy for 5 patients. Rigid registration and deformable image registration (DIR) using B-splines and Demons algorithms was performed with the CT data to obtain a deformation map between the functional images and planning CT. Contour propagation accuracy and correspondence of anatomic features were used to assess registration accuracy. Wilcoxon signed-rank test was used to determine statistical significance. Changes in lung perfusion resulting from radiation therapy dose were calculated for each registration method for each patient and averaged over all patients. Results: With B-splines/Demons DIR, median distance to agreement between lung contours reduced modestly by 0.9/1.1 mm, 1.3/1.6 mm, and 1.3/1.6 mm for pretreatment, midtreatment, and posttreatment (P<.01 for all), and median Dice score between lung contours improved by 0.04/0.04, 0.05/0.05, and 0.05/0.05 for pretreatment, midtreatment, and posttreatment (P<.001 for all). Distance between anatomic features reduced with DIR by median 2.5 mm and 2.8 for pretreatment and midtreatment time points, respectively (P=.001) and 1.4 mm for posttreatment (P>.2). Poorer posttreatment results were likely caused by posttreatment pneumonitis and tumor regression. Up to 80% standardized uptake value loss in perfusion scans was observed. There was limited change in the loss in lung perfusion between registration methods; however, Demons resulted in larger interpatient variation compared with rigid and B-splines registration. Conclusions

  10. Accuracy and Utility of Deformable Image Registration in {sup 68}Ga 4D PET/CT Assessment of Pulmonary Perfusion Changes During and After Lung Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hardcastle, Nicholas, E-mail: nick.hardcastle@gmail.com [Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne (Australia); Centre for Medical Radiation Physics, University of Wollongong, Wollongong (Australia); Hofman, Michael S. [Molecular Imaging, Centre for Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne (Australia); Hicks, Rodney J. [Molecular Imaging, Centre for Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne (Australia); Department of Medicine, University of Melbourne, Melbourne (Australia); Callahan, Jason [Molecular Imaging, Centre for Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne (Australia); Kron, Tomas [Department of Medical Imaging and Radiation Sciences, Monash University, Clayton (Australia); The Sir Peter MacCallum Department of Oncology, Melbourne University, Victoria (Australia); MacManus, Michael P.; Ball, David L. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne (Australia); The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne (Australia); Jackson, Price [Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne (Australia); Siva, Shankar [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne (Australia)

    2015-09-01

    Purpose: Measuring changes in lung perfusion resulting from radiation therapy dose requires registration of the functional imaging to the radiation therapy treatment planning scan. This study investigates registration accuracy and utility for positron emission tomography (PET)/computed tomography (CT) perfusion imaging in radiation therapy for non–small cell lung cancer. Methods: {sup 68}Ga 4-dimensional PET/CT ventilation-perfusion imaging was performed before, during, and after radiation therapy for 5 patients. Rigid registration and deformable image registration (DIR) using B-splines and Demons algorithms was performed with the CT data to obtain a deformation map between the functional images and planning CT. Contour propagation accuracy and correspondence of anatomic features were used to assess registration accuracy. Wilcoxon signed-rank test was used to determine statistical significance. Changes in lung perfusion resulting from radiation therapy dose were calculated for each registration method for each patient and averaged over all patients. Results: With B-splines/Demons DIR, median distance to agreement between lung contours reduced modestly by 0.9/1.1 mm, 1.3/1.6 mm, and 1.3/1.6 mm for pretreatment, midtreatment, and posttreatment (P<.01 for all), and median Dice score between lung contours improved by 0.04/0.04, 0.05/0.05, and 0.05/0.05 for pretreatment, midtreatment, and posttreatment (P<.001 for all). Distance between anatomic features reduced with DIR by median 2.5 mm and 2.8 for pretreatment and midtreatment time points, respectively (P=.001) and 1.4 mm for posttreatment (P>.2). Poorer posttreatment results were likely caused by posttreatment pneumonitis and tumor regression. Up to 80% standardized uptake value loss in perfusion scans was observed. There was limited change in the loss in lung perfusion between registration methods; however, Demons resulted in larger interpatient variation compared with rigid and B-splines registration

  11. Correlation between [{sup 18}F]FDG PET/CT and volume perfusion CT in primary tumours and mediastinal lymph nodes of non-small-cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sauter, Alexander W.; Spira, Daniel; Schulze, Maximilian; Pfannenberg, Christina; Claussen, Claus D.; Horger, Marius S. [Eberhard Karls University, Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Hetzel, Juergen [Eberhard Karls University, Department of Oncology, Hematology, Immunology, Rheumatology and Pulmonology, Tuebingen (Germany); Reimold, Matthias [Eberhard Karls University, Nuclear Medicine, Department of Radiology, Tuebingen (Germany); Klotz, Ernst [Siemens Healthcare, Computed Tomography, Forchheim (Germany)

    2013-05-15

    The aim of this study was to investigate correlations between glucose metabolism as determined by [{sup 18}F]FDG PET/CT and tumour perfusion as quantified by volume perfusion CT in primary tumours and mediastinal lymph nodes (MLN) of patients with non-small-cell lung cancer (NSCLC). Enrolled in the study were 17 patients with NSCLC. [{sup 18}F]FDG uptake was quantified in terms of SUV{sub max} and SUV{sub avg}. Blood flow (BF), blood volume (BV) and flow extraction product (K{sup trans}) were determined as perfusion parameters. The correlations between the perfusion parameters and [{sup 18}F]FDG uptake values were subsequently evaluated. For the primary tumours, no correlations were found between perfusion parameters and [{sup 18}F]FDG uptake. In MLN, there were negative correlations between BF and SUV{sub avg} (r = -0.383), BV and SUV{sub avg} (r = -0.406), and BV and SUV{sub max} (r = -0.377), but not between BF and SUV{sub max}, K{sup trans} and SUV{sub avg}, or K{sup trans} and SUV{sub max}. Additionally, in MLN with SUV{sub max} >2.5 there were negative correlations between BF and SUV{sub avg} (r = -0.510), BV and SUV{sub avg} (r = -0.390), BF and SUV{sub max} (r = -0.536), as well as BV and SUV{sub max} (r = -0.346). Perfusion and glucose metabolism seemed to be uncoupled in large primary tumours, but an inverse correlation was observed in MLN. This information may help improve therapy planning and response evaluation. (orig.)

  12. Dynamic contrast-enhanced perfusion area-detector CT assessed with various mathematical models: Its capability for therapeutic outcome prediction for non-small cell lung cancer patients with chemoradiotherapy as compared with that of FDG-PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe (Japan); Fujisawa, Yasuko [Toshiba Medical Systems Corporation, Otawara (Japan); Koyama, Hisanobu; Kishida, Yuji; Seki, Shinichiro [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Sugihara, Naoki [Toshiba Medical Systems Corporation, Otawara (Japan); Yoshikawa, Takeshi [Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe (Japan)

    2017-01-15

    Purpose: To directly compare the capability of dynamic first-pass contrast-enhanced (CE-) perfusion area-detector CT (ADCT) and PET/CT for early prediction of treatment response, disease progression and overall survival of non-small cell carcinoma (NSCLC) patients treated with chemoradiotherapy. Materials and methods: Fifty-three consecutive Stage IIIB NSCLC patients who had undergone PET/CT, dynamic first-pass CE-perfusion ADCT, chemoradiotherapy, and follow-up examination were enrolled in this study. They were divided into two groups: 1) complete or partial response (CR + PR) and 2) stable or progressive disease (SD + PD). Pulmonary arterial and systemic arterial perfusions and total perfusion were assessed at targeted lesions with the dual-input maximum slope method, permeability surface and distribution volume with the Patlak plot method, tumor perfusion with the single-input maximum slope method, and SUV{sub max}, and results were averaged to determine final values for each patient. Next, step-wise regression analysis was used to determine which indices were the most useful for predicting therapeutic effect. Finally, overall survival of responders and non-responders assessed by using the indices that had a significant effect on prediction of therapeutic outcome was statistically compared. Results: The step-wise regression test showed that therapeutic effect (r{sup 2} = 0.63, p = 0.01) was significantly affected by the following three factors in order of magnitude of impact: systemic arterial perfusion, total perfusion, and SUV{sub max}. Mean overall survival showed a significant difference for total perfusion (p = 0.003) and systemic arterial perfusion (p = 0.04). Conclusion: Dynamic first-pass CE-perfusion ADCT as well as PET/CT are useful for treatment response prediction in NSCLC patients treated with chemoradiotherapy.

  13. Dynamic contrast-enhanced perfusion area-detector CT assessed with various mathematical models: Its capability for therapeutic outcome prediction for non-small cell lung cancer patients with chemoradiotherapy as compared with that of FDG-PET/CT

    International Nuclear Information System (INIS)

    Ohno, Yoshiharu; Fujisawa, Yasuko; Koyama, Hisanobu; Kishida, Yuji; Seki, Shinichiro; Sugihara, Naoki; Yoshikawa, Takeshi

    2017-01-01

    Purpose: To directly compare the capability of dynamic first-pass contrast-enhanced (CE-) perfusion area-detector CT (ADCT) and PET/CT for early prediction of treatment response, disease progression and overall survival of non-small cell carcinoma (NSCLC) patients treated with chemoradiotherapy. Materials and methods: Fifty-three consecutive Stage IIIB NSCLC patients who had undergone PET/CT, dynamic first-pass CE-perfusion ADCT, chemoradiotherapy, and follow-up examination were enrolled in this study. They were divided into two groups: 1) complete or partial response (CR + PR) and 2) stable or progressive disease (SD + PD). Pulmonary arterial and systemic arterial perfusions and total perfusion were assessed at targeted lesions with the dual-input maximum slope method, permeability surface and distribution volume with the Patlak plot method, tumor perfusion with the single-input maximum slope method, and SUV max , and results were averaged to determine final values for each patient. Next, step-wise regression analysis was used to determine which indices were the most useful for predicting therapeutic effect. Finally, overall survival of responders and non-responders assessed by using the indices that had a significant effect on prediction of therapeutic outcome was statistically compared. Results: The step-wise regression test showed that therapeutic effect (r 2 = 0.63, p = 0.01) was significantly affected by the following three factors in order of magnitude of impact: systemic arterial perfusion, total perfusion, and SUV max . Mean overall survival showed a significant difference for total perfusion (p = 0.003) and systemic arterial perfusion (p = 0.04). Conclusion: Dynamic first-pass CE-perfusion ADCT as well as PET/CT are useful for treatment response prediction in NSCLC patients treated with chemoradiotherapy.

  14. Dynamic contrast-enhanced perfusion area-detector CT assessed with various mathematical models: Its capability for therapeutic outcome prediction for non-small cell lung cancer patients with chemoradiotherapy as compared with that of FDG-PET/CT.

    Science.gov (United States)

    Ohno, Yoshiharu; Fujisawa, Yasuko; Koyama, Hisanobu; Kishida, Yuji; Seki, Shinichiro; Sugihara, Naoki; Yoshikawa, Takeshi

    2017-01-01

    To directly compare the capability of dynamic first-pass contrast-enhanced (CE-) perfusion area-detector CT (ADCT) and PET/CT for early prediction of treatment response, disease progression and overall survival of non-small cell carcinoma (NSCLC) patients treated with chemoradiotherapy. Fifty-three consecutive Stage IIIB NSCLC patients who had undergone PET/CT, dynamic first-pass CE-perfusion ADCT, chemoradiotherapy, and follow-up examination were enrolled in this study. They were divided into two groups: 1) complete or partial response (CR+PR) and 2) stable or progressive disease (SD+PD). Pulmonary arterial and systemic arterial perfusions and total perfusion were assessed at targeted lesions with the dual-input maximum slope method, permeability surface and distribution volume with the Patlak plot method, tumor perfusion with the single-input maximum slope method, and SUV max , and results were averaged to determine final values for each patient. Next, step-wise regression analysis was used to determine which indices were the most useful for predicting therapeutic effect. Finally, overall survival of responders and non-responders assessed by using the indices that had a significant effect on prediction of therapeutic outcome was statistically compared. The step-wise regression test showed that therapeutic effect (r 2 =0.63, p=0.01) was significantly affected by the following three factors in order of magnitude of impact: systemic arterial perfusion, total perfusion, and SUV max . Mean overall survival showed a significant difference for total perfusion (p=0.003) and systemic arterial perfusion (p=0.04). Dynamic first-pass CE-perfusion ADCT as well as PET/CT are useful for treatment response prediction in NSCLC patients treated with chemoradiotherapy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Solitary pulmonary nodules: Comparison of dynamic first-pass contrast-enhanced perfusion area-detector CT, dynamic first-pass contrast-enhanced MR imaging, and FDG PET/CT.

    Science.gov (United States)

    Ohno, Yoshiharu; Nishio, Mizuho; Koyama, Hisanobu; Seki, Shinichiro; Tsubakimoto, Maho; Fujisawa, Yasuko; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Sugimura, Kazuro

    2015-02-01

    To prospectively compare the capabilities of dynamic perfusion area-detector computed tomography (CT), dynamic magnetic resonance (MR) imaging, and positron emission tomography (PET) combined with CT (PET/CT) with use of fluorine 18 fluorodeoxyglucose (FDG) for the diagnosis of solitary pulmonary nodules. The institutional review board approved this study, and written informed consent was obtained from each subject. A total of 198 consecutive patients with 218 nodules prospectively underwent dynamic perfusion area-detector CT, dynamic MR imaging, FDG PET/CT, and microbacterial and/or pathologic examinations. Nodules were classified into three groups: malignant nodules (n = 133) and benign nodules with low (n = 53) or high (n = 32) biologic activity. Total perfusion was determined with dual-input maximum slope models at area-detector CT, maximum and slope of enhancement ratio at MR imaging, and maximum standardized uptake value (SUVmax) at PET/CT. Next, all indexes for malignant and benign nodules were compared with the Tukey honest significant difference test. Then, receiver operating characteristic analysis was performed for each index. Finally, sensitivity, specificity, and accuracy were compared with the McNemar test. All indexes showed significant differences between malignant nodules and benign nodules with low biologic activity (P Dynamic perfusion area-detector CT is more specific and accurate than dynamic MR imaging and FDG PET/CT in the diagnosis of solitary pulmonary nodules in routine clinical practice. © RSNA, 2014.

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

    Science.gov (United States)

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

    2012-12-27

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

  17. The Effect of the Prosthetic Group on the Pharmacologic Properties of 18F-labeled Rhodamine B, a Potential Myocardial Perfusion Agent for PET

    Science.gov (United States)

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

    2013-01-01

    We recently reported the development of the 2-[18F]fluoroethyl ester of rhodamine B as a potential positron emission tomography (PET) tracer for myocardial perfusion imaging. This compound, which was prepared using a [18F]fluoroethyl prosthetic group, has significant uptake in the myocardium in rats, but also demonstrates relatively high liver uptake and is rapidly hydrolyzed in vivo in mice. We have now prepared 18F-labeled rhodamine B using three additional prosthetic groups (propyl, diethylene glycol, and triethylene glycol) and found that the prosthetic group has a significant effect on the in vitro and in vivo properties of these compounds. Of the esters prepared to date, the diethylene glycol ester is superior in terms of in vitro stability and pharmacokinetics. These observations suggest that the prosthetic group plays a significant role in determining the pharmacological properties of 18F-labeled compounds. They also support the value of continued investigation of 18F-labeled rhodamines as PET radiopharmaceuticals for myocardial perfusion imaging. PMID:23210516

  18. PET

    DEFF Research Database (Denmark)

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

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

  19. Dynamic Contrast-Enhanced Perfusion Area-Detector CT: Preliminary Comparison of Diagnostic Performance for N Stage Assessment With FDG PET/CT in Non-Small Cell Lung Cancer.

    Science.gov (United States)

    Ohno, Yoshiharu; Fujisawa, Yasuko; Sugihara, Naoki; Kishida, Yuji; Seki, Shinichiro; Koyama, Hisanobu; Yoshikawa, Takeshi

    2017-11-01

    The objective of our study was to directly compare the capability of dynamic first-pass contrast-enhanced (CE) perfusion area-detector CT (ADCT) and FDG PET/CT for differentiation of metastatic from nonmetastatic lymph nodes and assessment of N stage in patients with non-small cell lung carcinoma (NSCLC). Seventy-seven consecutive patients, 45 men (mean age ± SD, 70.4 ± 5.9 years) and 32 women (71.2 ± 7.7 years), underwent dynamic first-pass CE-perfusion ADCT at two or three different positions for covering the entire thorax, FDG PET/CT, surgical treatment, and pathologic examination. From all ADCT data for each of the subjects, a whole-chest perfusion map was computationally generated using the dual- and single-input maximum slope and Patlak plot methods. For quantitative N stage assessment, perfusion parameters and the maximum standardized uptake value (SUV max ) for each lymph node were determined by measuring the relevant ROI. ROC curve analyses were performed for comparing the diagnostic capability of each of the methods on a per-node basis. N stages evaluated by each of the indexes were then statistically compared with the final pathologic diagnosis by means of chi-square and kappa statistics. The area under the ROC curve (A z ) values of systemic arterial perfusion (A z = 0.89), permeability surface (A z = 0.78), and SUV max (A z = 0.85) were significantly larger than the A z values of total perfusion (A z = 0.70, p Dynamic first-pass CE-perfusion ADCT is as useful as FDG PET/CT for the differentiation of metastatic from nonmetastatic lymph nodes and assessment of N stage in patients with NSCLC.

  20. Grading and outcome prediction of pediatric diffuse astrocytic tumors with diffusion and arterial spin labeling perfusion MRI in comparison with 18F-DOPA PET

    Energy Technology Data Exchange (ETDEWEB)

    Morana, Giovanni; Tortora, Domenico; Severino, Mariasavina; Rossi, Andrea [Istituto Giannina Gaslini, Neuroradiology Unit, Genoa (Italy); Piccardo, Arnoldo; Cabria, Manlio [Ente Ospedaliero Ospedali Galliera, Nuclear Medicine Unit, Genoa (Italy); Puntoni, Matteo [Ente Ospedaliero Ospedali Galliera, Clinical Trial Unit, Scientific Directorate, Genoa (Italy); Nozza, Paolo [Istituto Giannina Gaslini, Pathology Unit, Genoa (Italy); Ravegnani, Marcello; Consales, Alessandro; Mascelli, Samantha; Raso, Alessandro [Istituto Giannina Gaslini, Neurosurgery Unit, Genoa (Italy); Verrico, Antonio; Milanaccio, Claudia [Istituto Giannina Gaslini, Neuro-oncology Unit, Genoa (Italy)

    2017-11-15

    The aim of this study was to investigate MRI-derived diffusion weighted imaging (DWI) and arterial spin labeling (ASL) perfusion imaging in comparison with {sup 18}F-dihydroxyphenylalanine (DOPA) PET with respect to diagnostic performance in tumor grading and outcome prediction in pediatric patients with diffuse astrocytic tumors (DAT). We retrospectively analyzed 26 children with histologically proven treatment naive low and high grade DAT who underwent ASL and DWI performed within 2 weeks of {sup 18}F-DOPA PET. Relative ASL-derived cerebral blood flow max (rCBF max) and DWI-derived minimum apparent diffusion coefficient (rADC min) were compared with {sup 18}F-DOPA uptake tumor/normal tissue (T/N) and tumor/striatum (T/S) ratios, and correlated with World Health Organization (WHO) tumor grade and progression-free survival (PFS). Statistics included Pearson's chi-square and Mann-Whitney U tests, Spearman's rank correlation, receiver operating characteristic (ROC) analysis, discriminant function analysis (DFA), Kaplan-Meier survival curve, and Cox analysis. A significant correlation was demonstrated between rCBF max, rADC min, and {sup 18}F-DOPA PET data (p < 0.001). Significant differences in terms of rCBF max, rADC min, and {sup 18}F-DOPA uptake were found between low- and high-grade DAT (p ≤ 0.001). ROC analysis and DFA demonstrated that T/S and T/N values were the best parameters for predicting tumor progression (AUC 0.93, p < 0.001). On univariate analysis, all diagnostic tools correlated with PFS (p ≤ 0.001); however, on multivariate analysis, only {sup 18}F-DOPA uptake remained significantly associated with outcome (p ≤ 0.03), while a trend emerged for rCBF max (p = 0.09) and rADC min (p = 0.08). The combination of MRI and PET data increased the predictive power for prognosticating tumor progression (AUC 0.97, p < 0.001). DWI, ASL and {sup 18}F-DOPA PET provide useful complementary information for pediatric DAT grading. {sup 18}F-DOPA uptake

  1. Usefulness of abdominal belt for restricting respiratory cardiac motion and improving image quality in myocardial perfusion PET.

    Science.gov (United States)

    Ichikawa, Yasutaka; Tomita, Yoya; Ishida, Masaki; Kobayashi, Shigeki; Takeda, Kan; Sakuma, Hajime

    2018-04-01

    The current study evaluated the usefulness of a belt technique for restricting respiratory motion of the heart and for improving image quality of 13 N-ammonia myocardial PET/CT, and it assessed the tolerability of the belt technique in the clinical setting. Myocardial 13 N-ammonia PET/CT scanning was performed in 8 volunteers on Discovery PET/CT 690 with an optical respiratory motion tracking system. Emission scans were performed with and without an abdominal belt. The amplitude of left ventricular (LV) respiratory motion was measured on respiratory-gated PET images. The degree of erroneous decreases in regional myocardial uptake was visually assessed on ungated PET images using a 5-point scale (0 = normal, 1/2/3 = mild/moderate/severe decrease, 4 = defect). The tolerability of the belt technique was evaluated in 53 patients. All subjects tolerated the belt procedure. The amplitude of the LV respiratory motion decreased significantly with the belt (8.1 ± 7.1 vs 12.1 ± 6.1 mm, P = .0078). The belt significantly improved the image quality scores in the anterior (0.29 ± 0.81 vs 0.71 ± 1.04, P = .015) and inferior (0.33 ± 0.92 vs 1.04 ± 1.04, P PET/CT, and it is well tolerated by patients.

  2. Detection of misery perfusion in the cerebral hemisphere with chronic unilateral major cerebral artery steno-occlusive disease using crossed cerebellar hypoperfusion: comparison of brain SPECT and PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Yoshiyasu; Ogasawara, Kuniaki; Saito, Hideo; Takahashi, Yoshihiro; Ogasawara, Yasushi; Kobayashi, Masakazu; Ogawa, Akira [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Terasaki, Kazunori [Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Yoshida, Kenji; Beppu, Takaaki; Kubo, Yoshitaka; Fujiwara, Shunrou [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Tsushima, Eiki [Hirosaki University, Graduate School of Health Sciences, Hirosaki (Japan)

    2013-10-15

    In patients with unilateral internal carotid or middle cerebral artery (ICA or MCA) occlusive disease, the degree of crossed cerebellar hypoperfusion that is evident within a few months after the onset of stroke may reflect cerebral metabolic rate of oxygen in the affected cerebral hemisphere relative to that in the contralateral cerebral hemisphere. The aim of the present study was to determine whether the ratio of blood flow asymmetry in the cerebellar hemisphere to blood flow asymmetry in the cerebral hemisphere on positron emission tomography (PET) and single photon emission computed tomography (SPECT) correlates with oxygen extraction fraction (OEF) asymmetry in the cerebral hemisphere on PET in patients with chronic unilateral ICA or MCA occlusive disease and whether this blood flow ratio on SPECT detects misery perfusion in the affected cerebral hemisphere in such patients. Brain blood flow and OEF were assessed using {sup 15}O-PET and N-isopropyl-p-[{sup 123}I]iodoamphetamine ({sup 123}I-IMP) SPECT, respectively. All images were anatomically standardized using SPM2. A region of interest (ROI) was automatically placed in the bilateral MCA territories and in the bilateral cerebellar hemispheres using a three-dimensional stereotaxic ROI template, and affected-to-contralateral asymmetry in the MCA territory or contralateral-to-affected asymmetry in the cerebellar hemisphere was calculated. Sixty-three patients with reduced blood flow in the affected cerebral hemisphere on {sup 123}I-IMP SPECT were enrolled in this study. A significant correlation was observed between MCA ROI asymmetry of PET OEF and the ratio of cerebellar hemisphere asymmetry of blood flow to MCA ROI asymmetry of blood flow on PET (r = 0.381, p = 0.0019) or SPECT (r = 0.459, p = 0.0001). The correlation coefficient was higher when reanalyzed in a subgroup of 43 patients undergoing a PET study within 3 months after the last ischemic event (r = 0.541, p = 0.0001 for PET; r = 0.609, p < 0

  3. Tumor metabolism and perfusion ratio assessed by 18F-FDG PET/CT and DCE-MRI in breast cancer patients: Correlation with tumor subtype and histologic prognostic factors

    Energy Technology Data Exchange (ETDEWEB)

    An, Young-Sil [Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine (Korea, Republic of); Kang, Doo Kyoung [Department of Radiology, Ajou University School of Medicine (Korea, Republic of); Jung, Yong Sik; Han, Sehwan [Department of Surgery, Ajou University School of Medicine (Korea, Republic of); Kim, Tae Hee, E-mail: medhand@ajou.ac.kr [Department of Radiology, Ajou University School of Medicine (Korea, Republic of)

    2015-07-15

    Highlights: • In non-triple negative breast cancer, metabolic parameter (SUVmax) was significantly correlated with perfusion parameters (Kep and Ve). • In triple negative cancers, any perfusion parameters did not correlated with metabolic parameters. • Higher SUVmax, higher SUVmax/Ktrans, higher MTV50/Ktrans, higher TLG50/Ktrans, higher TLG50/Ve ratios were significantly correlated with TNBC. • In triple negative breast cancer, perfusion and metabolic parameters are not significantly correlated. • Triple negative breast cancer showed higher metabolic–perfusion ratios compared to non-triple negative breast cancer. - Abstract: Objective: Our purpose was to evaluate whether breast cancer with high metabolic–perfusion ratio would be associated with poor histopathologic prognostic factors and whether triple negative breast cancer (TNBC) would show high metabolic–perfusion ratio compared to non-triple negative breast cancer (non-TNBC). Methods: From March 2011 to November 2011, 67 females with invasive ductal carcinoma of breast who underwent both MRI and 18F-FDG PET/CT were included. Perfusion parameters including Ktrans, Kep and Ve were acquired from Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Metabolic parameters including the standardized uptake value (SUV) and volumetric metabolic parameters including metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were obtained from F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). Results: In non-TNBC, SUVmax was significantly correlated with Kep (ρ = 0.298, p = 0.036) and Ve (ρ = −0.286, p = 0.044). In TNBC, there was no significant correlation between all perfusion and metabolic parameters. Compared to non-TNBC, higher SUVmax (10.2 vs 5.3, p < 0.001), higher SUVmax/Ktrans (56.02 vs 20.3, p < 0.001), higher MTV50/Ktrans (7.8 vs 16.54, p < 0.001), higher TLG50/Ktrans (36.49 vs 12.3, p < 0.001), higher TLG50/Ve (91.34 vs 27.1 p = 0.022) were

  4. Imaging characteristic of dual-phase 18F-florbetapir (AV-45/Amyvid) PET for the concomitant detection of perfusion deficits and beta-amyloid deposition in Alzheimer's disease and mild cognitive impairment

    International Nuclear Information System (INIS)

    Lin, Kun-Ju; Hsiao, Ing-Tsung; Hsieh, Chia-Ju; Wey, Shiaw-Pyng; Yen, Tzu-Chen; Hsu, Jung-Lung; Huang, Chin-Chang; Huang, Kuo-Lun

    2016-01-01

    We investigated dual-phase 18 F-florbetapir (AV-45/Amyvid) PET imaging for the concomitant detection of brain perfusion deficits and beta-amyloid deposition in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (MCI), and in cognitively healthy controls (HCs). A total of 82 subjects (24 AD patients, 44 MCI patients and 14 HCs) underwent both dual-phase 18 F-AV-45 PET and MRI imaging. Dual-phase dynamic PET imaging consisted of (1) five 1-min scans obtained 1 - 6 min after tracer injection (perfusion 18 F-AV-45 imaging, pAV-45), and (2) ten 1-min scans obtained 50 - 60 min after tracer injection (amyloid 18 F-AV-45 imaging). Amyloid-negative MCI/AD patients were excluded. Volume of interest analysis and statistical parametric mapping of pAV-45 and 18 F-AV-45 images were performed to investigate the perfusion deficits and the beta-amyloid burden in the three study groups. The associations between Mini-Mental State Examination (MMSE) scores and global perfusion deficits and amyloid deposition were investigated with linear and segmental linear correlation analyses. HCs generally had normal pAV-45 findings, whereas perfusion deficits were evident in the hippocampus, and temporal, parietal and middle frontal cortices in both MCI and AD patients. The motor-sensory cortex was relatively preserved. MMSE scores in the entire study cohort were significantly associated with the degree of perfusion impairment as assessed by pAV-45 imaging (r = 0.5156, P < 0.0001). 18 F-AV-45 uptake was significantly higher in AD patients than in the two other study groups. However, the correlation between MMSE scores and 18 F-AV-45 uptake in MCI patients was more of a binary phenomenon and began in MCI patients with MMSE score 23.14 when 18 F-AV-45 uptake was higher and MMSE score lower than in patients with early MCI. Amyloid deposition started in the precuneus and the frontal and temporal regions in early MCI, ultimately reaching the maximum burden in advanced

  5. Imaging characteristic of dual-phase {sup 18}F-florbetapir (AV-45/Amyvid) PET for the concomitant detection of perfusion deficits and beta-amyloid deposition in Alzheimer's disease and mild cognitive impairment

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Kun-Ju; Hsiao, Ing-Tsung; Hsieh, Chia-Ju; Wey, Shiaw-Pyng; Yen, Tzu-Chen [Linkou Chang Gung Memorial Hospital and University, Department of Nuclear Medicine and Molecular Imaging Center, Taoyuan (China); Chang Gung University, Department of Medical Imaging and Radiological Sciences and Healthy Aging Research Center, Taoyuan (China); Hsu, Jung-Lung [Linkou Chang Gung Memorial Hospital, Section of Dementia and Cognitive Impairment, Department of Neurology, Taoyuan (China); Taipei Medical University, Graduate Institute of Humanities in Medicine, Taipei (China); Huang, Chin-Chang; Huang, Kuo-Lun [Linkou Chang Gung Memorial Hospital and University, Department of Neurology, Taoyuan (China)

    2016-07-15

    We investigated dual-phase {sup 18}F-florbetapir (AV-45/Amyvid) PET imaging for the concomitant detection of brain perfusion deficits and beta-amyloid deposition in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (MCI), and in cognitively healthy controls (HCs). A total of 82 subjects (24 AD patients, 44 MCI patients and 14 HCs) underwent both dual-phase {sup 18}F-AV-45 PET and MRI imaging. Dual-phase dynamic PET imaging consisted of (1) five 1-min scans obtained 1 - 6 min after tracer injection (perfusion {sup 18}F-AV-45 imaging, pAV-45), and (2) ten 1-min scans obtained 50 - 60 min after tracer injection (amyloid {sup 18}F-AV-45 imaging). Amyloid-negative MCI/AD patients were excluded. Volume of interest analysis and statistical parametric mapping of pAV-45 and {sup 18}F-AV-45 images were performed to investigate the perfusion deficits and the beta-amyloid burden in the three study groups. The associations between Mini-Mental State Examination (MMSE) scores and global perfusion deficits and amyloid deposition were investigated with linear and segmental linear correlation analyses. HCs generally had normal pAV-45 findings, whereas perfusion deficits were evident in the hippocampus, and temporal, parietal and middle frontal cortices in both MCI and AD patients. The motor-sensory cortex was relatively preserved. MMSE scores in the entire study cohort were significantly associated with the degree of perfusion impairment as assessed by pAV-45 imaging (r = 0.5156, P < 0.0001). {sup 18}F-AV-45 uptake was significantly higher in AD patients than in the two other study groups. However, the correlation between MMSE scores and {sup 18}F-AV-45 uptake in MCI patients was more of a binary phenomenon and began in MCI patients with MMSE score 23.14 when {sup 18}F-AV-45 uptake was higher and MMSE score lower than in patients with early MCI. Amyloid deposition started in the precuneus and the frontal and temporal regions in early MCI, ultimately

  6. Evaluation of endothelium-dependent myocardial perfusion reserve in healthy smokers; cold pressor test using H215O PET

    International Nuclear Information System (INIS)

    Hwang, Kyung Hoon; Lee, Dong Soo; Lee, Byeong Il; Lee, Jae Sung; Lee, Ho Young; Chung, June Key; Lee, Myung Chul

    2004-01-01

    Much evidence suggests long-term cigarette smoking alters coronary vascular endothelial response. In this study, we applied nonnegative matrix factorization (NMF), an unsupervised learning algorithm, to CO-less H 2 15 O-PET to investigate coronary endothelial dysfunction caused by smoking noninvasively. This study enrolled eighteen young male volunteers consisting of 9 smokers (23.8±1.1 yr; 6.6±2.5 pack-years) and 9 nonsmokers (23.8±2.9 yr). They do not have any cardiovascular risk factor or disease history. Myocardial H 2 15 O-PET was performed at rest, during cold (5.deg.C) pressor stimulation and during adenosine infusion. Left ventricular blood pool and myocardium were segmented on dynamic PET data by NMF method. Myocardial blood flow (MBF) was calculated from input and tissue functions by a single compartmental model with correction of partial volume and spillover effects. There were no significant difference in resting MBF between the two groups (Smokers: 1.43 0.41ml/g/min and non-smokers: 1.37±0.41 ml/g/min; p = NS). during cold pressor stimulation, MBF in smokers was significantly lower than that in non-smokers (1.25±0.34 ml/g/min vs 1.59±0.29 ml/g/min ; p = 0.019). The difference in the ratio of cold pressor MBF to resting MBF between the two groups was also significant (p=0.024; 90±24% in smokers and 122±28% in non-smokers.). During adenosine infusion, however, hyperemic MBF did not differ significantly between smokers and non-smokers (5.81±1.99 ml/g/min vs 5.11±1.31 ml/g/min ; p=NS). In smokers, MBF during cold pressor stimulation was significantly lower compared with nonsmokers, reflecting smoking-induced endothelial dysfunction. However, there was no significant difference in MBF during adenosine-induced hyperemia between the two groups

  7. Volumetric assessment of recurrent or progressive gliomas: comparison between F-DOPA PET and perfusion-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Cicone, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Filss, Christian P.; Langen, Karl-Josef [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; RWTH Aachen Univ. Hospital (Germany). Dept. of Nuclear Medicine; Minniti, Giuseppe; Scaringi, Claudia [Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Sant' Andrea Hospital, Rome (Italy). Unit of Radiotherapy; Rossi-Espagnet, Camilla; Bozzao, Alessandro [Sant' Andrea Hospital, Rome (Italy). Unit of Neuroradiology; Rome Sapienza Univ. (Italy). Dept. of Neurosciences, Mental Health and Sensory Organs (Ne.S.M.O.S.); Papa, Annalisa; Scopinaro, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Galldiks, Norbert [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Cologne Univ. (Germany). Dept. of Neurology; Shah, N. Jon [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine

    2015-05-01

    To compare the diagnostic information obtained with 6-[{sup 18}F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET and relative cerebral blood volume (rCBV) maps in recurrent or progressive glioma. All patients with recurrent or progressive glioma referred for F-DOPA imaging at our institution between May 2010 and May 2014 were retrospectively included, provided that macroscopic disease was visible on conventional MRI images and that rCBV maps were available for comparison. The final analysis included 50 paired studies (44 patients). After image registration, automatic tumour segmentation of both sets of images was performed using the average signal in a large reference VOI including grey and white matter multiplied by 1.6. Tumour volumes identified by both modalities were compared and their spatial congruence calculated. The distances between F-DOPA uptake and rCBV hot spots, tumour-to-brain ratios (TBRs) and normalized histograms were also computed. On visual inspection, 49 of the 50 F-DOPA and 45 of the 50 rCBV studies were classified as positive. The tumour volume delineated using F-DOPA (F-DOPA{sub vol} {sub 1.6}) greatly exceeded that of rCBV maps (rCBV{sub vol} {sub 1.6}). The median F-DOPA{sub vol} {sub 1.6} and rCBV{sub vol} {sub 1.6} were 11.44 ml (range 0 - 220.95 ml) and 1.04 ml (range 0 - 26.30 ml), respectively (p < 0.00001). Overall, the median overlapping volume was 0.27 ml, resulting in a spatial congruence of 1.38 % (range 0 - 39.22 %). The mean hot spot distance was 27.17 mm (±16.92 mm). F-DOPA uptake TBR was significantly higher than rCBV TBR (1.76 ± 0.60 vs. 1.15 ± 0.52, respectively; p < 0.0001). The histogram analysis showed that F-DOPA provided better separation of tumour from background. In 6 of the 50 studies (12 %), however, physiological uptake in the striatum interfered with tumour delineation. The information provided by F-DOPA PET and rCBV maps are substantially different. Image interpretation is easier and a larger tumour extent

  8. Comparison of the myocardial blood flow response to regadenoson and dipyridamole: a quantitative analysis in patients referred for clinical {sup 82}Rb myocardial perfusion PET

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Behnaz; Fukushima, Kenji; Bravo, Paco; Merrill, Jennifer [Johns Hopkins University, Division of Nuclear Medicine, Russell H Morgan Department of Radiology, Baltimore, MD (United States); Bengel, Frank M. [Johns Hopkins University, Division of Nuclear Medicine, Russell H Morgan Department of Radiology, Baltimore, MD (United States); Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany)

    2011-10-15

    Regadenoson is a novel selective A{sub 2A} adenosine receptor agonist, which is administered as an intravenous bolus at a fixed dose. It is currently not clear if the absolute flow increase in response to this fixed dose is a function of distribution volume in individual patients or if it is generally comparable to the previous standard agents dipyridamole or adenosine, which are dosed based on weight. We used quantitative analysis of clinical {sup 82}Rb PET/CT studies to obtain further insights. A total of 104 subjects with normal clinical rest/stress {sup 82}Rb perfusion PET/CT were included in a retrospective analysis. To rule out confounding factors, none had evidence of prior cardiac disease, ischaemia or infarction, cardiomyopathy, diabetes with insulin use, calcium score >400, renal disease or other significant systemic disease. A group of 52 patients stressed with regadenoson were compared with a group of 52 patients stressed with dipyridamole before regadenoson became available. The groups were matched for clinical characteristics, risk factors and baseline haemodynamics. Myocardial blood flow (MBF) and myocardial flow reserve (MFR) were quantified using a previously validated retention model, after resampling of dynamic studies from list-mode {sup 82}Rb datasets. At rest, heart rate, blood pressure and MBF were comparable between the groups. Regadenoson resulted in a significantly higher heart rate (34 {+-} 14 vs. 23 {+-} 10 beats per minute increase from baseline; p < 0.01) and rate-pressure product. Patients in the regadenoson group reported less severe symptoms and required less aminophylline. Stress MBF and MFR were not different between the groups (2.2 {+-} 0.6 vs. 2.1 {+-} 0.6 ml/min/g, p = 0.39, and 2.9 {+-} 0.8 vs. 2.8 {+-} 0.7, p = 0.31, respectively). In the regadenoson group, there was no correlation between stress flow or MFR and body weight or BMI. Despite its administration at a fixed dose, regadenoson results in an absolute increase in MBF

  9. Comparison of the myocardial blood flow response to regadenoson and dipyridamole: a quantitative analysis in patients referred for clinical 82Rb myocardial perfusion PET

    International Nuclear Information System (INIS)

    Goudarzi, Behnaz; Fukushima, Kenji; Bravo, Paco; Merrill, Jennifer; Bengel, Frank M.

    2011-01-01

    Regadenoson is a novel selective A 2A adenosine receptor agonist, which is administered as an intravenous bolus at a fixed dose. It is currently not clear if the absolute flow increase in response to this fixed dose is a function of distribution volume in individual patients or if it is generally comparable to the previous standard agents dipyridamole or adenosine, which are dosed based on weight. We used quantitative analysis of clinical 82 Rb PET/CT studies to obtain further insights. A total of 104 subjects with normal clinical rest/stress 82 Rb perfusion PET/CT were included in a retrospective analysis. To rule out confounding factors, none had evidence of prior cardiac disease, ischaemia or infarction, cardiomyopathy, diabetes with insulin use, calcium score >400, renal disease or other significant systemic disease. A group of 52 patients stressed with regadenoson were compared with a group of 52 patients stressed with dipyridamole before regadenoson became available. The groups were matched for clinical characteristics, risk factors and baseline haemodynamics. Myocardial blood flow (MBF) and myocardial flow reserve (MFR) were quantified using a previously validated retention model, after resampling of dynamic studies from list-mode 82 Rb datasets. At rest, heart rate, blood pressure and MBF were comparable between the groups. Regadenoson resulted in a significantly higher heart rate (34 ± 14 vs. 23 ± 10 beats per minute increase from baseline; p < 0.01) and rate-pressure product. Patients in the regadenoson group reported less severe symptoms and required less aminophylline. Stress MBF and MFR were not different between the groups (2.2 ± 0.6 vs. 2.1 ± 0.6 ml/min/g, p = 0.39, and 2.9 ± 0.8 vs. 2.8 ± 0.7, p = 0.31, respectively). In the regadenoson group, there was no correlation between stress flow or MFR and body weight or BMI. Despite its administration at a fixed dose, regadenoson results in an absolute increase in MBF which is comparable to that

  10. Left ventricular function in response to dipyridamole stress: head-to-head comparison between {sup 82}Rubidium PET and {sup 99m}Tc-sestamibi SPECT ECG-gated myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Giorgi, Maria Clementina; Meneghetti, Jose Claudio; Soares, Jose; Izaki, Marisa; Falcao, Andrea; Imada, Rodrigo; Chalela, William; Oliveira, Marco Antonio de; Nomura, Cesar [Department of Radiology and Nuclear Medicine and Molecular Imaging Service - Heart Institute of the University of Sao Paulo Medical School, Sao Paulo (Brazil); Verberne, Hein J. [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, P.O. Box 22700, Amsterdam (Netherlands)

    2017-05-15

    Myocardial perfusion imaging (MPI) with {sup 99m}Tc-sestamibi (sestamibi) SPECT and rubidium-82 ({sup 82}Rb) PET both allow for combined assessment of perfusion and left ventricular (LV) function. We sought to compare parameters of LV function obtained with both methods using a single dipyridamole stress dose. A group of 221 consecutive patients (65.2 ± 10.4 years, 52.9% male) underwent consecutive sestamibi and {sup 82}Rb MPI after a single dipyridamole stress dose. Sestamibi and {sup 82}Rb summed rest (SRS), stress (SSS) and difference (SDS) scores, and LV end-diastolic (EDV) and end-systolic (ESV) volumes and left ventricular ejection fraction (LVEF) were compared. Bland-Altman analysis showed that with increasing ESV and EDV the difference between the two perfusion tracers increased both at rest and post-stress. The mean difference in EDV and ESV between the two perfusion tracers at rest could both be independently explained by the {sup 82}Rb SDS and the sestamibi SRS. The combined models explained approximately 30% of the variation in these volumes between the two perfusion tracers (R{sup 2} = 0.261, p = 0.005; R{sup 2} = 0.296, p < 0.001, for EDV and ESV respectively). However, the mean difference in LVEF between sestamibi and {sup 82}Rb showed no significant trend post-stress (R{sup 2} = 0.001, p = 0.70) and only a modest linear increase with increasing LVEF values at rest (R{sup 2} = 0.032, p = 0.009). Differences in left ventricular volumes between sestamibi and {sup 82}Rb MPI increase with increasing volumes. However, these differences did only marginally affect LVEF between sestamibi and {sup 82}Rb. In clinical practice these results should be taken into account when comparing functional derived parameters between sestamibi and {sup 82}Rb MPI. (orig.)

  11. Quantification of MRI measured myocardial perfusion reserve in healthy humans: A comparison with positron emission tomography

    DEFF Research Database (Denmark)

    Fritz-Hansen, T.; Hove, J.D.; Kofoed, K.F.

    2008-01-01

    Purpose: To validate a noninvasive quantitative MRI technique, the K-i perfusion method, for myocardial perfusion in humans using N-13-ammonia PET as a reference method. Materials and Methods: Ten healthy males (64 +/- 8 years) were examined with combined PET and MRI perfusion imaging at rest and...

  12. Brain perfusion: computed tomography applications

    International Nuclear Information System (INIS)

    Miles, K.A.

    2004-01-01

    Within recent years, the broad introduction of fast multi-detector computed tomography (CT) systems and the availability of commercial software for perfusion analysis have made cerebral perfusion imaging with CT a practical technique for the clinical environment. The technique is widely available at low cost, accurate and easy to perform. Perfusion CT is particularly applicable to those clinical circumstances where patients already undergo CT for other reasons, including stroke, head injury, subarachnoid haemorrhage and radiotherapy planning. Future technical developments in multi-slice CT systems may diminish the current limitations of limited spatial coverage and radiation burden. CT perfusion imaging on combined PET-CT systems offers new opportunities to improve the evaluation of patients with cerebral ischaemia or tumours by demonstrating the relationship between cerebral blood flow and metabolism. Yet CT is often not perceived as a technique for imaging cerebral perfusion. This article reviews the use of CT for imaging cerebral perfusion, highlighting its advantages and disadvantages and draws comparisons between perfusion CT and magnetic resonance imaging. (orig.)

  13. Renal perfusion scintiscan

    Science.gov (United States)

    ... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

  14. Prognostic relevance of {sup 18}F-FDG PET uptake in patients with locally advanced, extremity soft tissue sarcomas undergoing neoadjuvant isolated limb perfusion with TNF-α and melphalan

    Energy Technology Data Exchange (ETDEWEB)

    Andreou, Dimosthenis [Muenster University Hospital, Department of General Orthopedics and Tumor Orthopedics, Muenster (Germany); HELIOS Klinikum Berlin-Buch, Department of Orthopedic Oncology, Sarcoma Center Berlin-Brandenburg, Berlin (Germany); Boldt, Henrike [HELIOS Klinikum Berlin-Buch, Department of Nuclear Medicine, Berlin (Germany); Pink, Daniel [HELIOS Klinikum Bad Saarow, Department of Hematology, Oncology and Palliative Care, Sarcoma Center Berlin-Brandenburg, Bad Saarow (Germany); Jobke, Bjoern [HELIOS Klinikum Berlin-Buch, Department of Radiology, Berlin (Germany); Werner, Mathias [HELIOS Klinikum Emil von Behring, Department of Pathology, Sarcoma Center Berlin-Brandenburg, Berlin (Germany); Schuler, Markus [University Hospital Carl Gustav Carus Dresden, Department of Internal Medicine I, Dresden (Germany); Reichardt, Peter [HELIOS Klinikum Berlin-Buch, Department of Interdisciplinary Oncology, Sarcoma Center Berlin-Brandenburg, Berlin (Germany); Tunn, Per-Ulf [HELIOS Klinikum Berlin-Buch, Department of Orthopedic Oncology, Sarcoma Center Berlin-Brandenburg, Berlin (Germany)

    2014-06-15

    The objective of this study was to determine whether {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET) can adequately assess the risk of systemic disease progression in patients with primary, localized, high-grade soft tissue sarcomas of the extremities undergoing neoadjuvant isolated limb perfusion (ILP) with tumour necrosis factor and melphalan. This was a retrospective analysis of the files of 35 patients who underwent a PET or PET/CT scan prior to and after ILP followed by surgical resection with curative intent between 2006 and 2012. SUV{sub max1} was defined as the maximum standardized uptake value (SUV) at diagnosis, SUV{sub max2} as the maximum SUV after ILP and ΔSUV{sub max} as the percentage difference between SUV{sub max1} and SUV{sub max2}. The median follow-up was 40 months for all patients. The median SUV{sub max1} amounted to 7.6, while the median SUV{sub max2} was 4.7. The median ΔSUV{sub max} was -44 %. Overall survival (OS) probability at 2 and 5 years amounted to 78 and 70 %, respectively, while metastasis-free survival (MFS) probability at 2 and 5 years was 67 and 64 %, respectively. Receiver-operating characteristic (ROC) curve analysis showed that both SUV{sub max2} and ΔSUV{sub max} could predict systemic disease progression, while SUV{sub max1} could not adequately identify patients who went on to develop metastatic disease. The optimal cut-off value was 6.9 for SUV{sub max2} and -31 % for ΔSUV{sub max}. Patients with an SUV{sub max2} <6.9 had a 2-year MFS of 80 %, compared to 31 % for patients with an SUV{sub max2} ≥ 6.9 (p < 0.001). Patients with a ΔSUV{sub max} < -31 %, i.e. patients with a higher metabolic response, had an MFS of 76 % at 2 years, compared to 42 % for patients with a ΔSUV{sub max} ≥ -31 % (p = 0.050). SUV{sub max} after ILP for primary, locally advanced, non-metastatic high-grade soft tissue sarcomas of the extremities appears to be significantly correlated with prognosis. Whether patients

  15. Evaluation of endothelium-dependent myocardial perfusion reserve in healthy smokers; cold pressor test using H{sub 2}{sup 15}O PET

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyung Hoon [School of Medicine, Gachon Univ., Incheon (Korea, Republic of); Lee, Dong Soo; Lee, Byeong Il; Lee, Jae Sung; Lee, Ho Young; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2004-02-01

    Much evidence suggests long-term cigarette smoking alters coronary vascular endothelial response. In this study, we applied nonnegative matrix factorization (NMF), an unsupervised learning algorithm, to CO-less H{sub 2}{sup 15}O-PET to investigate coronary endothelial dysfunction caused by smoking noninvasively. This study enrolled eighteen young male volunteers consisting of 9 smokers (23.8{+-}1.1 yr; 6.6{+-}2.5 pack-years) and 9 nonsmokers (23.8{+-}2.9 yr). They do not have any cardiovascular risk factor or disease history. Myocardial H{sub 2}{sup 15}O-PET was performed at rest, during cold (5.deg.C) pressor stimulation and during adenosine infusion. Left ventricular blood pool and myocardium were segmented on dynamic PET data by NMF method. Myocardial blood flow (MBF) was calculated from input and tissue functions by a single compartmental model with correction of partial volume and spillover effects. There were no significant difference in resting MBF between the two groups (Smokers: 1.43 0.41ml/g/min and non-smokers: 1.37{+-}0.41 ml/g/min; p = NS). during cold pressor stimulation, MBF in smokers was significantly lower than that in non-smokers (1.25{+-}0.34 ml/g/min vs 1.59{+-}0.29 ml/g/min ; p = 0.019). The difference in the ratio of cold pressor MBF to resting MBF between the two groups was also significant (p=0.024; 90{+-}24% in smokers and 122{+-}28% in non-smokers.). During adenosine infusion, however, hyperemic MBF did not differ significantly between smokers and non-smokers (5.81{+-}1.99 ml/g/min vs 5.11{+-}1.31 ml/g/min ; p=NS). In smokers, MBF during cold pressor stimulation was significantly lower compared with nonsmokers, reflecting smoking-induced endothelial dysfunction. However, there was no significant difference in MBF during adenosine-induced hyperemia between the two groups.

  16. Semi-quantitative myocardial perfusion measured by computed tomography in patients with refractory angina

    DEFF Research Database (Denmark)

    Qayyum, Abbas Ali; Kühl, Jørgen Tobias; Kjaer, Andreas

    2017-01-01

    INTRODUCTION: Computed tomography (CT) is a novel method for assessment of myocardial perfusion and has not yet been compared to rubidium-82 positron emission tomography (PET). We aimed to compare CT measured semi-quantitative myocardial perfusion with absolute quantified myocardial perfusion usi...

  17. A Comparative pO2 Probe and [18F]-Fluoro-Azomycinarabino-Furanoside ([18F]FAZA) PET Study Reveals Anesthesia-Induced Impairment of Oxygenation and Perfusion in Tumor and Muscle.

    Science.gov (United States)

    Mahling, Moritz; Fuchs, Kerstin; Thaiss, Wolfgang M; Maier, Florian C; Feger, Martina; Bukala, Daniel; Harant, Maren; Eichner, Martin; Reutershan, Jörg; Lang, Florian; Reischl, Gerald; Pichler, Bernd J; Kneilling, Manfred

    2015-01-01

    CT26 colon carcinoma-bearing mice were anesthetized with isoflurane (IF) or ketamine/xylazine (KX) while breathing air or oxygen (O2). We performed 10 min static PET scans 1 h, 2 h and 3 h after [18F]FAZA injection and calculated the [18F]FAZA-uptake and tumor-to-muscle ratios (T/M). In another experimental group, we placed a pO2 probe in the tumor as well as in the gastrocnemius muscle to measure the pO2 and perfusion. Ketamine/xylazine-anesthetized mice yielded up to 3.5-fold higher T/M-ratios compared to their isoflurane-anesthetized littermates 1 h, 2 h and 3 h after [18F]FAZA injection regardless of whether the mice breathed air or oxygen (3 h, KX-air: 7.1 vs. IF-air: 1.8, p = 0.0001, KX-O2: 4.4 vs. IF-O2: 1.4, p pO2 probe measurements yielded enhanced intra-tumoral pO2 values in air- and oxygen-breathing ketamine/xylazine-anesthetized mice compared to isoflurane-anesthetized mice (KX-air: 1.01 mmHg, IF-air: 0.45 mmHg; KX-O2 9.73 mmHg, IF-O2: 6.25 mmHg). Muscle oxygenation was significantly higher in air-breathing isoflurane-anesthetized (56.9 mmHg) than in ketamine/xylazine-anesthetized mice (33.8 mmHg, p = 0.0003). [18F]FAZA tumor uptake was highest in ketamine/xylazine-anesthetized mice regardless of whether the mice breathed air or oxygen. The generally lower [18F]FAZA whole-body uptake in isoflurane-anesthetized mice could be due to the higher muscle pO2-values in these mice compared to ketamine/xylazine-anesthetized mice. When performing preclinical in vivo hypoxia PET studies, oxygen should be avoided, and ketamine/xylazine-anesthesia might alleviate the identification of tumor hypoxia areals.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-03-01

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

  19. Myocardial perfusion in type 2 diabetes with left ventricular hypertrophy

    DEFF Research Database (Denmark)

    Hesse, Birger; Meyer, Christian; Nielsen, Flemming S

    2004-01-01

    The purpose of this study was to assess whether acute angiotensin-converting enzyme (ACE) inhibition would improve myocardial perfusion and perfusion reserve in a subpopulation of normotensive patients with diabetes and left ventricular hypertrophy (LVH), both independent risk factors of coronary...... disease. Using positron emission tomography (PET), we investigated the response of regional myocardial perfusion to acute ACE inhibition with i.v. infusion of perindoprilat (vs saline infusion as control, minimum interval 3 days) in 12 diabetic patients with LVH. Myocardial perfusion was quantified...... with controls, maximal perfusion was reduced in patients (1.8+/-0.6 vs 2.5+/-1.0 ml min(-1) g(-1); P2.7+/-1.0 vs 3.6+/-1.3; P=0.059). During perindoprilat infusion, myocardial perfusion reserve in patients increased to 3.9+/-0.9 ( P

  20. Quantitative simultaneous PET-MR imaging

    Science.gov (United States)

    Ouyang, Jinsong; Petibon, Yoann; Huang, Chuan; Reese, Timothy G.; Kolnick, Aleksandra L.; El Fakhri, Georges

    2014-06-01

    Whole-body PET is currently limited by the degradation due to patient motion. Respiratory motion degrades imaging studies of the abdomen. Similarly, both respiratory and cardiac motions significantly hamper the assessment of myocardial ischemia and/or metabolism in perfusion and viability cardiac PET studies. Based on simultaneous PET-MR, we have developed robust and accurate MRI methods allowing the tracking and measurement of both respiratory and cardiac motions during abdominal or cardiac studies. Our list-mode iterative PET reconstruction framework incorporates the measured motion fields into PET emission system matrix as well as the time-dependent PET attenuation map and the position dependent point spread function. Our method significantly enhances the PET image quality as compared to conventional methods.

  1. Correlative assessment of cerebral blood flow obtained with perfusion CT and positron emission tomography in symptomatic stenotic carotid disease

    Energy Technology Data Exchange (ETDEWEB)

    Bisdas, Sotirios [JWG University Hospital, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Nemitz, Ole; Becker, Hartmut; Donnerstag, Frank [Hannover Medical School, Department of Neuroradiology, Hannover (Germany); Berding, Georg [Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany); Weissenborn, Karin; Ahl, Bjoern [Hannover Medical School, Department of Neurology, Hannover (Germany)

    2006-10-15

    Twelve patients with ICA stenosis underwent dynamic perfusion computed tomography (CT) and positron emission tomography (PET) studies at rest and after acetazolamide challenge. Cerebral blood flow (CBF) maps on perfusion CT resulted from a deconvolution of parenchymal time-concentration curves by an arterial input function (AIF) in the anterior cerebral artery as well as in both anterior choroidal arteries. CBF was measured by [{sup 15}O]H{sub 2}O PET using multilinear least-squares minimization procedure based on the one-compartment model. In corresponding transaxial PET scans, CBF values were extracted using standardized ROIs. The baseline perfusion CT-CBF values were lower in perfusion CT than in PET (P>0.05). CBF values obtained by perfusion CT were significantly correlated with those measured by PET before (P<0.05) and after (P<0.01) acetazolamide challenge. Nevertheless, the cerebrovascular reserve capacity was overestimated (P=0.05) using perfusion CT measurements. The AIF selection relative to the side of carotid stenosis did not significantly affect calculated perfusion CT-CBF values. In conclusion, the perfusion CT-CBF measurements correlate significantly with the PET-CBF measurements in chronic carotid stenotic disease and contribute useful information to the evaluation of the altered cerebral hemodynamics. (orig.)

  2. Correlative assessment of cerebral blood flow obtained with perfusion CT and positron emission tomography in symptomatic stenotic carotid disease

    International Nuclear Information System (INIS)

    Bisdas, Sotirios; Nemitz, Ole; Becker, Hartmut; Donnerstag, Frank; Berding, Georg; Weissenborn, Karin; Ahl, Bjoern

    2006-01-01

    Twelve patients with ICA stenosis underwent dynamic perfusion computed tomography (CT) and positron emission tomography (PET) studies at rest and after acetazolamide challenge. Cerebral blood flow (CBF) maps on perfusion CT resulted from a deconvolution of parenchymal time-concentration curves by an arterial input function (AIF) in the anterior cerebral artery as well as in both anterior choroidal arteries. CBF was measured by [ 15 O]H 2 O PET using multilinear least-squares minimization procedure based on the one-compartment model. In corresponding transaxial PET scans, CBF values were extracted using standardized ROIs. The baseline perfusion CT-CBF values were lower in perfusion CT than in PET (P>0.05). CBF values obtained by perfusion CT were significantly correlated with those measured by PET before (P<0.05) and after (P<0.01) acetazolamide challenge. Nevertheless, the cerebrovascular reserve capacity was overestimated (P=0.05) using perfusion CT measurements. The AIF selection relative to the side of carotid stenosis did not significantly affect calculated perfusion CT-CBF values. In conclusion, the perfusion CT-CBF measurements correlate significantly with the PET-CBF measurements in chronic carotid stenotic disease and contribute useful information to the evaluation of the altered cerebral hemodynamics. (orig.)

  3. Tumor Metabolism and Perfusion in Head and Neck Squamous Cell Carcinoma: Pretreatment Multimodality Imaging With 1H Magnetic Resonance Spectroscopy, Dynamic Contrast-Enhanced MRI, and [18F]FDG-PET

    International Nuclear Information System (INIS)

    Jansen, Jacobus F.A.; Schöder, Heiko; Lee, Nancy Y.; Stambuk, Hilda E.; Wang Ya; Fury, Matthew G.; Patel, Senehal G.; Pfister, David G.; Shah, Jatin P.; Koutcher, Jason A.; Shukla-Dave, Amita

    2012-01-01

    Purpose: To correlate proton magnetic resonance spectroscopy ( 1 H-MRS), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and 18 F-labeled fluorodeoxyglucose positron emission tomography ([ 18 F]FDG PET) of nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) for assessment of tumor biology. Additionally, pretreatment multimodality imaging was evaluated for its efficacy in predicting short-term response to treatment. Methods and Materials: Metastatic neck nodes were imaged with 1 H-MRS, DCE-MRI, and [ 18 F]FDG PET in 16 patients with newly diagnosed HNSCC, before treatment. Short-term patient radiological response was evaluated at 3 to 4 months. Correlations among 1 H-MRS (choline concentration relative to water [Cho/W]), DCE-MRI (volume transfer constant [K trans ]; volume fraction of the extravascular extracellular space [v e ]; and redistribution rate constant [k ep ]), and [ 18 F]FDG PET (standard uptake value [SUV] and total lesion glycolysis [TLG]) were calculated using nonparametric Spearman rank correlation. To predict short-term responses, logistic regression analysis was performed. Results: A significant positive correlation was found between Cho/W and TLG (ρ = 0.599; p = 0.031). Cho/W correlated negatively with heterogeneity measures of standard deviation std(v e ) (ρ = −0.691; p = 0.004) and std(k ep ) (ρ = −0.704; p = 0.003). Maximum SUV (SUVmax) values correlated strongly with MRI tumor volume (ρ = 0.643; p = 0.007). Logistic regression indicated that std(K trans ) and SUVmean were significant predictors of short-term response (p 1 H-MRS, DCE-MRI, and [ 18 F]FDG PET is feasible in HNSCC patients with nodal metastases. Additionally, combined DCE-MRI and [ 18 F]FDG PET parameters were predictive of short-term response to treatment.

  4. Quantitative myocardial blood flow with Rubidium-82 PET

    DEFF Research Database (Denmark)

    Hagemann, Christoffer E; Ghotbi, Adam A; Kjær, Andreas

    2015-01-01

    Positron emission tomography (PET) allows assessment of myocardial blood flow in absolute terms (ml/min/g). Quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR) extend the scope of conventional semi-quantitative myocardial perfusion imaging (MPI): e.g. in 1) identificat......Positron emission tomography (PET) allows assessment of myocardial blood flow in absolute terms (ml/min/g). Quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR) extend the scope of conventional semi-quantitative myocardial perfusion imaging (MPI): e.g. in 1...... global MFR and major adverse cardiovascular events (MACE), and together with new diagnostic possibilities from measuring the longitudinal myocardial perfusion gradient, cardiac (82)Rb PET faces a promising clinical future. This article reviews current evidence on quantitative (82)Rb PET's ability...

  5. The role of PET quantification in cardiovascular imaging.

    Science.gov (United States)

    Slomka, Piotr; Berman, Daniel S; Alexanderson, Erick; Germano, Guido

    2014-08-01

    Positron Emission Tomography (PET) has several clinical and research applications in cardiovascular imaging. Myocardial perfusion imaging with PET allows accurate global and regional measurements of myocardial perfusion, myocardial blood flow and function at stress and rest in one exam. Simultaneous assessment of function and perfusion by PET with quantitative software is currently the routine practice. Combination of ejection fraction reserve with perfusion information may improve the identification of severe disease. The myocardial viability can be estimated by quantitative comparison of fluorodeoxyglucose ( 18 FDG) and rest perfusion imaging. The myocardial blood flow and coronary flow reserve measurements are becoming routinely included in the clinical assessment due to enhanced dynamic imaging capabilities of the latest PET/CT scanners. Absolute flow measurements allow evaluation of the coronary microvascular dysfunction and provide additional prognostic and diagnostic information for coronary disease. Standard quantitative approaches to compute myocardial blood flow from kinetic PET data in automated and rapid fashion have been developed for 13 N-ammonia, 15 O-water and 82 Rb radiotracers. The agreement between software methods available for such analysis is excellent. Relative quantification of 82 Rb PET myocardial perfusion, based on comparisons to normal databases, demonstrates high performance for the detection of obstructive coronary disease. New tracers, such as 18 F-flurpiridaz may allow further improvements in the disease detection. Computerized analysis of perfusion at stress and rest reduces the variability of the assessment as compared to visual analysis. PET quantification can be enhanced by precise coregistration with CT angiography. In emerging clinical applications, the potential to identify vulnerable plaques by quantification of atherosclerotic plaque uptake of 18 FDG and 18 F-sodium fluoride tracers in carotids, aorta and coronary arteries

  6. SPECT and PET imaging in epilepsia

    International Nuclear Information System (INIS)

    Landvogt, C.

    2007-01-01

    In preoperative localisation of epileptogenic foci, nuclear medicine diagnostics plays a crucial role. FDG-PET is used as first line diagnostics. In case of inconsistent MRI, EEG and FDG-PET findings, 11 C-Flumazenil-PET or ictal and interictal perfusion-SPECT should be performed. Other than FDG, Flumazenil can help to identify the extend of the region, which should be resected. To enhance sensitivity and specificity, further data analysis using voxelbased statistical analyses or SISCOM (substraction ictal SPECT coregistered MRI) should be performed

  7. Lung PET scan

    Science.gov (United States)

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

  8. PET in cerebrovascular disease; PET bei zerebrovaskulaeren Erkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Herholz, K. [Neurologische Universitaetsklinik der Univ. Koeln (Germany)]|[Max-Planck-Institut fuer Neurologische Forschung, Koeln (Germany)

    1997-03-01

    Tissue viability is of particular interest in acute cerebral ischemia because it may be preserved if reperfusion can be achieved rapidly, e.g. by acute thrombolysis. Measurements of regional cerebral blood flow (CBF) and oxygen consumption by PET can assess tissue viability, and they have substantially increased our knowledge of th pathophysiology of ischemic stroke and the associated penumbra. Widerspread clinical application in acute stroke, however, is unlikely because of the large logistic and personnel resources required. In chronic cerebrovascular disease, measurement of regional CBF and glucose metabolism, which is usually coupled, provide detailed insights in disturbance of cortical function, e.g. due to deafferentiation, and contribute to differentiation of dementia types. Chronic misery perfusion, i.e. reduced perfusion that does not match the metabolic demand of the tissue, can be demonstrated by PET. It may be found in some patients with high-grade arterial stenoses. Less severe impairment of brain perfusion can be demonstrated by measurement of the cerebrovascular reserve capacity. The most frequent clinical situations can be assessed by less demanding procedures, e.g. by SPECT. In conclusion, PET has its role in cerebrovascular disease primarily within scientific studies, where high resolution and absolute quantitation of physiological variables are essential. (orig.). 65 refs. [Deutsch] Beim akuten ischaemischen Insult ist die Vitalitaet des Gewebes von besonderem Interesse, da sie durch rasche Reperfusion, z.B. durch Thrombolyse, erhalten bleiben kann. Messungen der zerebralen Durchblutung und des Sauerstoffumsatzes mittels PET geben darueber wesentliche Aufschluesse, und sie sind wichtig fuer das Verstaendnis der Pathophysiologie ischaemischer Infarkte und der Penumbra mit kritischer Perfusion beim Menschen. Ihre breitere Anwendung in der klinischen Patientenversorgung kommt allerdings wegen des hohen Aufwandes derzeit kaum in Betracht. Bei

  9. Perfusion dyssynchrony analysis

    NARCIS (Netherlands)

    Chiribiri, A.; Villa, A.D.M.; Sammut, E.; Breeuwer, M.; Nagel, E.

    2015-01-01

    AIMS: We sought to describe perfusion dyssynchrony analysis specifically to exploit the high temporal resolution of stress perfusion CMR. This novel approach detects differences in the temporal distribution of the wash-in of contrast agent across the left ventricular wall. METHODS AND RESULTS:

  10. Anatomy and function: PET-CT.

    Science.gov (United States)

    Kajander, Sami; Saraste, Antti; Ukkonen, Heikki; Knuuti, Juhani

    2010-05-01

    CT coronary angiography and perfusion PET form an attractive combination to study coronary artery lesions and their consequences in patients with coronary artery disease. Whereas CT provides non-invasive assessment of coronary lumen and wall, PET perfusion is a reliable method for the evaluation of myocardial flow. CT, although very capable of ruling out significant coronary artery disease, is less than satisfactory in assessing the actual significance of the detected lesions. PET imaging, despite its excellent sensitivity, fails to describe the exact anatomy of the epicardial vessels. By fusing image data from these two modalities, lesions can be accurately correlated with their physiological or anatomical counterparts. Hybrid PET-CT devices, now in wide clinical use, allow such fusion in a one-stop-shop study. Although still seeking its place in clinical scenarios, growing evidence suggests that hybrid PET-CT imaging of coronary anatomy and myocardial perfusion can accurately - and non-invasively - assess the existence and degree of coronary artery disease.

  11. Laser doppler perfusion imaging

    International Nuclear Information System (INIS)

    Waardell, K.

    1992-01-01

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 μm. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs

  12. PET/CT cardiology: an area whose boundaries are still out of sight

    Energy Technology Data Exchange (ETDEWEB)

    Lucignani, Giovanni [University of Milan and Unit of Molecular Imaging, Institute of Radiological Sciences, Division of Radiation Therapy, European Institute of Oncology, Milan (Italy)

    2006-05-15

    Positron emission tomography (PET) and X-ray computed tomography (CT) performed with PET/CT cameras allow us to obtain concurrently information on the presence and degree of alterations of myocardial perfusion and metabolism and on coronary arteries calcification. Furthermore, by gated myocardial perfusion studies, PET may provide crucial information on regional coronary blood flow reserve and endothelial dysfunction. A number of recent papers provide some insight on the potential of PET/CT in cardiology and in the assessment of various cardiovascular diseases including various types of vasculitis and metabolic diseases.

  13. Quantitative PET of liver functions.

    Science.gov (United States)

    Keiding, Susanne; Sørensen, Michael; Frisch, Kim; Gormsen, Lars C; Munk, Ole Lajord

    2018-01-01

    Improved understanding of liver physiology and pathophysiology is urgently needed to assist the choice of new and upcoming therapeutic modalities for patients with liver diseases. In this review, we focus on functional PET of the liver: 1) Dynamic PET with 2-deoxy-2-[ 18 F]fluoro- D -galactose ( 18 F-FDGal) provides quantitative images of the hepatic metabolic clearance K met (mL blood/min/mL liver tissue) of regional and whole-liver hepatic metabolic function. Standard-uptake-value ( SUV ) from a static liver 18 F-FDGal PET/CT scan can replace K met and is currently used clinically. 2) Dynamic liver PET/CT in humans with 11 C-palmitate and with the conjugated bile acid tracer [ N -methyl- 11 C]cholylsarcosine ( 11 C-CSar) can distinguish between individual intrahepatic transport steps in hepatic lipid metabolism and in hepatic transport of bile acid from blood to bile, respectively, showing diagnostic potential for individual patients. 3) Standard compartment analysis of dynamic PET data can lead to physiological inconsistencies, such as a unidirectional hepatic clearance of tracer from blood ( K 1 ; mL blood/min/mL liver tissue) greater than the hepatic blood perfusion. We developed a new microvascular compartment model with more physiology, by including tracer uptake into the hepatocytes from the blood flowing through the sinusoids, backflux from hepatocytes into the sinusoidal blood, and re-uptake along the sinusoidal path. Dynamic PET data include information on liver physiology which cannot be extracted using a standard compartment model. In conclusion , SUV of non-invasive static PET with 18 F-FDGal provides a clinically useful measurement of regional and whole-liver hepatic metabolic function. Secondly, assessment of individual intrahepatic transport steps is a notable feature of dynamic liver PET.

  14. Quantitative PET of liver functions

    Science.gov (United States)

    Keiding, Susanne; Sørensen, Michael; Frisch, Kim; Gormsen, Lars C; Munk, Ole Lajord

    2018-01-01

    Improved understanding of liver physiology and pathophysiology is urgently needed to assist the choice of new and upcoming therapeutic modalities for patients with liver diseases. In this review, we focus on functional PET of the liver: 1) Dynamic PET with 2-deoxy-2-[18F]fluoro-D-galactose (18F-FDGal) provides quantitative images of the hepatic metabolic clearance K met (mL blood/min/mL liver tissue) of regional and whole-liver hepatic metabolic function. Standard-uptake-value (SUV) from a static liver 18F-FDGal PET/CT scan can replace K met and is currently used clinically. 2) Dynamic liver PET/CT in humans with 11C-palmitate and with the conjugated bile acid tracer [N-methyl-11C]cholylsarcosine (11C-CSar) can distinguish between individual intrahepatic transport steps in hepatic lipid metabolism and in hepatic transport of bile acid from blood to bile, respectively, showing diagnostic potential for individual patients. 3) Standard compartment analysis of dynamic PET data can lead to physiological inconsistencies, such as a unidirectional hepatic clearance of tracer from blood (K 1; mL blood/min/mL liver tissue) greater than the hepatic blood perfusion. We developed a new microvascular compartment model with more physiology, by including tracer uptake into the hepatocytes from the blood flowing through the sinusoids, backflux from hepatocytes into the sinusoidal blood, and re-uptake along the sinusoidal path. Dynamic PET data include information on liver physiology which cannot be extracted using a standard compartment model. In conclusion, SUV of non-invasive static PET with 18F-FDGal provides a clinically useful measurement of regional and whole-liver hepatic metabolic function. Secondly, assessment of individual intrahepatic transport steps is a notable feature of dynamic liver PET. PMID:29755841

  15. SPECT and PET imaging in epilepsia; SPECT und PET in der Diagnostik von Epilepsien

    Energy Technology Data Exchange (ETDEWEB)

    Landvogt, C. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    2007-09-15

    In preoperative localisation of epileptogenic foci, nuclear medicine diagnostics plays a crucial role. FDG-PET is used as first line diagnostics. In case of inconsistent MRI, EEG and FDG-PET findings, {sup 11}C-Flumazenil-PET or ictal and interictal perfusion-SPECT should be performed. Other than FDG, Flumazenil can help to identify the extend of the region, which should be resected. To enhance sensitivity and specificity, further data analysis using voxelbased statistical analyses or SISCOM (substraction ictal SPECT coregistered MRI) should be performed.

  16. Pulmonary perfusion ''without ventilation''

    International Nuclear Information System (INIS)

    Chapman, C.N.; Sziklas, J.J.; Spencer, R.P.; Rosenberg, R.J.

    1983-01-01

    An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a ''reversed ventilation/perfusion mismatch.''

  17. Automatic delineation of brain regions on MRI and PET images from the pig

    DEFF Research Database (Denmark)

    Villadsen, Jonas; Hansen, Hanne D; Jørgensen, Louise M

    2018-01-01

    : Manual inter-modality spatial normalization to a MRI atlas is operator-dependent, time-consuming, and can be inaccurate with lack of cortical radiotracer binding or skull uptake. NEW METHOD: A parcellated PET template that allows for automatic spatial normalization to PET images of any radiotracer....... RESULTS: MRI and [11C]Cimbi-36 PET scans obtained in sixteen pigs made the basis for the atlas. The high resolution MRI scans allowed for creation of an accurately averaged MRI template. By aligning the within-subject PET scans to their MRI counterparts, an averaged PET template was created in the same...... the MRI template with individual MRI images and 0.92±0.26mm using the PET template with individual [11C]Cimbi-36 PET images. We tested the automatic procedure by assessing eleven PET radiotracers with different kinetics and spatial distributions by using perfusion-weighted images of early PET time frames...

  18. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    Science.gov (United States)

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions.

  19. Pharmacological studies of the lung with PET

    International Nuclear Information System (INIS)

    Syrota, A.

    1986-10-01

    Positron emission tomography (PET), known to be used for lung ventilation and perfusion studies, can also be used in pharmacology to obtain information that is otherwise not available. The lung takes up biologically active substances which can be inactivated or activated, and synthesises and releases others. Such information in man has been obtained from samples of human lungs, or from in vivo first-pass studies, invasive or not, as well as from in vivo kinetic studies using external detection methods with scintillation cameras. PET provides now quantitative regional data in the human lung

  20. Quantitative assessment of the physical potential of proton beam range verification with PET/CT

    NARCIS (Netherlands)

    Knopf, A; Parodi, K.; Paganetti, Harald; Lo Cascio, E; Bonab, A; Bortfeld, Thomas

    2008-01-01

    A recent clinical pilot study demonstrated the feasibility of offline PET/CT range verification for proton therapy treatments. In vivo PET measurements are challenged by blood perfusion, variations of tissue compositions, patient motion and image co-registration uncertainties. Besides these

  1. POSTEROLATERAL DEFECT OF THE NORMAL HUMAN HEART INVESTIGATED WITH NITROGEN-13-AMMONIA AND DYNAMIC PET

    NARCIS (Netherlands)

    DEJONG, RM; BLANKSMA, PK; WILLEMSEN, ATM; ANTHONIO, RL; MEEDER, JG; PRUIM, J; VAALBURG, W; LIE, KI

    The posterolateral defect is a common artifact seen when static N-13-ammonia imaging with PET is used to assess myocardial perfusion. The aim of this study was to compare dynamic and static N-13-ammonia PET and to obtain more insight into the cause of the posterolateral defect. Methods: Dynamic

  2. Basal hyperaemia is the primary abnormality of perfusion in Takotsubo cardiomyopathy

    DEFF Research Database (Denmark)

    Christensen, Thomas Emil; Ahtarovski, Kiril Aleksov; Bang, Lia Evi

    2015-01-01

    AIMS: Takotsubo cardiomyopathy (TTC) is characterized by acute completely reversible regional left ventricle (LV) akinesia and decreased tracer uptake in the akinetic region on semi-quantitative perfusion imaging. The latter may be due to normoperfusion of the akinetic mid/apical area and basal...... hyperperfusion. Our aim was to examine abnormalities of perfusion in TTC, and we hypothesized that basal hyperperfusion is the primary perfusion abnormality in the acute state. METHOD AND RESULTS: Twenty-five patients were diagnosed with TTC due to (i) acute onset of symptoms, (ii) typical apical ballooning......-on follow-up. Patients initially had severe heart failure, mid/apical oedema but no infarction, and a rise in cardiac biomarkers. On initial perfusion PET imaging, eight patients appeared to have normal, whereas 17 patients had impaired LV perfusion. In the latter, flow in the basal region was increased...

  3. Pet Health

    Science.gov (United States)

    ... companionship and a feeling of safety to your life. Before getting a pet, think carefully about which ... Gaining or losing a lot of weight quickly Strange behavior Being sluggish and tired Trouble getting up ...

  4. Reverse ventilation--perfusion mismatch

    International Nuclear Information System (INIS)

    Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

    1984-01-01

    Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients

  5. Pet Allergy Quiz

    Science.gov (United States)

    ... Treatments ▸ Allergies ▸ Pet Allergy ▸ Pet Allergy Quiz Share | Pet Allergy Quiz More than half of U.S. households ... cat family. Yet, millions of people suffer from pet allergies. Take this quiz to test your knowledge ...

  6. Analysis of local perfusion rate (LPR) and local glucose transport rate (LGTR) in brain and heart in man by means of C-11-methyl-D-glucose (CMG) and dynamic positron emission tomography (dPET)

    International Nuclear Information System (INIS)

    Vyska, K.; Freundlieb, C.; Hoeck, A.; Becker, V.; Schmidt, A.; Feinendegen, L.E.; Kloster, G.; Stoecklin, G.; Heiss, W.D.

    1982-01-01

    A method has been developed to measure simultaneously the LPR and LGTR. CMG is used as an indicator. The transaxial distribution of activity in organism is registered with dPET. On the basis of a mathematical model, the LPR and LGTR can be calculated in terms of parameters of the time activity curves registered over different brain or heart regions and over the sup. long. sinus (brain) or the ventricular cavity (heart) (blood activity). The method was used in 10 normal subjects and 20 patients with ischemic brain or heart disease. The values of LGTR range from 0.43 to 0.6 μmol/min g in normal cortex and from 0.09 to 0.12 μmol/min g in normal white matter. The LPR was 0.9-098 ml/min g for the cortex and 0.3-0.4 ml/min g for the white matter. In patients with stroke the ischemic defects appeared to be larger in CMG scans than in CT. The results obtained in a patient with left homonymous hemianopia, caused by infarctions in the distribution area of RMCA, and in a patient with TIA, demonstrate that the inactivation of morphologically intact, cerebral cortex, observed in stroke patients, may be caused by undercutting of cortical fiber tracts as well as by the impairment of the glucose transport systems in the inactivated area. In myocardial studies the LPR in normal left myocardium was 0.68 ml/min g (subendocardium 0.74 ml/min g; subepicardiuim 0.65 ml/min g). In patients with old myocardial infarction, the infarcted areas could be easily recognized as accumulation defects. The results obtained in a patient with narrowing of the RCA indicate that repeated exposure of myocardial tissue to transient ischemia produces an irreversible damage of the glucose transport system. We conclude from the data that for diagnostic evaluation of ultimate brain or heart damage simultaneous quantitative assessment of both LPR and LGTR is of basic importance. (Author)

  7. Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Welch, M.J.

    1990-01-01

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

  8. Positron Emission Tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Welch, M.J.

    1990-01-01

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

  9. Positron Emission Tomography (PET)

    Science.gov (United States)

    Welch, M. J.

    1990-01-01

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

  10. Hepatic artery perfusion imaging

    International Nuclear Information System (INIS)

    Thrall, J.H.; Gyves, J.W.; Ziessman, H.A.; Ensminger, W.D.

    1985-01-01

    Organ and region-selective intra-arterial chemotherapy have been used for more than two decades to treat malignant neoplasms in the extremities, head and neck region, pelvis, liver, and other areas. Substantial evidence of improved response to regional chemotherapy now exists, but there are stringent requirements for successful application of the regional technique. First, the chemotherapeutic agent employed must have appropriate pharmacokinetic and pharmacodynamic properties. Second, the drug must be reliably delivered to the tumor-bearing area. This typically requires an arteriographic assessment of the vascular supply of the tumor, followed by placement of a therapeutic catheter and confirmation that the ''watershed'' perfusion distribution from the catheter truly encompasses the tumor. Optimal catheter placement also minimizes perfusion of nontarget organs. Radionuclide perfusion imaging with technetium 99m-labeled particles, either microspheres or macroaggregates of albumin, has become the method of choice for making these assessments. Catheter placement itself is considered by many to represent a type of ''therapeutic'' intervention. However, once the catheter is in the hepatic artery the radionuclide perfusion technique can be used to assess adjunctive pharmacologic maneuvers designed to further exploit the regional approach to chemotherapy. This chapter presents the technetium Tc 99m macroaggregated albumin method for assessing catheter placement and the pharmacokinetic rationale for regional chemotherapy, and discusses two promising avenues for further intervention

  11. Extremity perfusion for sarcoma

    NARCIS (Netherlands)

    Hoekstra, Harald Joan

    2008-01-01

    For more than 50 years, the technique of extremity perfusion has been explored in the limb salvage treatment of local, recurrent, and multifocal sarcomas. The "discovery" of tumor necrosis factor-or. in combination with melphalan was a real breakthrough in the treatment of primarily irresectable

  12. Isolated limb perfusion.

    Science.gov (United States)

    Gillespie, Rosalyn; Chantier, Nariane

    1994-12-08

    Growing concern over the rising incidence of malignant melanoma has brought about a need for information on this disorder and the treatment available. Isolated limb perfusion is a relatively new technique used in only a few hospitals. An increased knowledge base will lead to a better understanding of the nursing care required and to a more in-depth care plan.

  13. Cardiac 82rubidium PET/CT: initial European experience

    International Nuclear Information System (INIS)

    Groves, Ashley M.; Dickson, John C.; Kayani, Irfan; Endozo, Raymondo; Blanchard, Patty; Shastry, Manu; Prvulovich, Elizabeth; Waddington, Wendy A.; Ben-Haim, Simona; Bomanji, Jamshed B.; Ell, Peter J.; Speechly-Dick, Marie-Elsya; McEwan, Jean R.

    2007-01-01

    Myocardial perfusion with PET/CT has advantages over conventional SPECT. We describe our initial European experience using 82 Rubidium-PET/CT, as part of a clinical myocardial perfusion service. We studied the first 100 patients (64 male; 36 female, mean age = 60: SD +/-12.5y, mean body mass index = 30: SD +/-6.9kg/m 2 ) who underwent 82 Rubidium cardiac PET/CT in our institution. Thirty patients had recently undergone coronary angiography. Patients underwent imaging during adenosine infusion and at rest. Images were acquired over 5 minutes using a GE-PET/CT instrument. Image quality was described as good, adequate or inadequate. Images were reported patient-by-patient by a minimum of five nuclear medicine physicians. A segment-by-segment analysis (17-segment model) was also performed. Image quality was good in 77%, adequate 23% and inadequate 0%. There was no statistical difference in image quality between obese and non-obese patients (Fisher's exact test, p = 0.2864). 59% had normal perfusion studies, 29% had inducible ischaemia, 12% had myocardial infarction (11% with super added ischaemia). There was reduced 82 Rubidium uptake in 132/1700 segments during stress. There was reduced 82 Rubidium uptake at rest in 42/1700 segments. The 82 Rubidium PET/CT findings were consistent with the angiographic findings in 28/30 cases. We show that, even from initial use of 82 Rubidium, it is possible to perform myocardial perfusion studies quickly with good image quality, even in the obese. The PET findings correlated well in the third of the cases where angiography was available. As such, 82 Rubidium cardiac PET/CT is likely to be an exciting addition to the European nuclear physician/ cardiologist's radionuclide imaging arsenal. (orig.)

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    data was compared with Spearman's rho and Bland-Altman analysis. RESULTS: CMRI results were strongly and significantly correlated with PET results for the absolute global myocardial perfusion differences (r=0.805, p=0.001) and for global myocardial perfusion reserve (MPR) (r=0.886, p... territorial level, CMRI results were also significantly correlated with absolute PET myocardial perfusion differences (r=0.737, pr=0.818, pr=0.787, p=0.......001; left anterior descending artery (LAD): r=0.796, p=0.001; left circumflex artery (LCX): r=0.880, pr=0.895, pr=0.886, pr=0.886, p

  15. Association between left ventricular perfusion defects and myocardial deformation indexes in heart transplantation recipients.

    Science.gov (United States)

    D'Andrea, Antonello; De Rimini, Maria Luisa; America, Raffaella; Cirillo, Chiara; Riegler, Lucia; Limongelli, Giuseppe; D'Alto, Michele; Salerno, Gemma; Maiello, Ciro; Muto, Pietro; Russo, Maria Giovanna; Calabrò, Raffaele; Bossone, Eduardo; Pacileo, Giuseppe

    2017-10-01

    The aim of the study was to analyze possible correlations between strain echocardiography (STE) and PET myocardial perfusion in a population of heart transplantation (HTx) recipients showing preserved left ventricular (LV) ejection fraction. By STE, LV global longitudinal strain (LV GLS) was lower in HTx. PET showed no transient or chronic ischemia in 83 of 115 HTx (73%). Fixed perfusion defects were observed in 17% of HTx and reversible ischemia in 10%. Significant coronary stenosis was observed only in 10 cases. GLS was independently associated with age at HTx and fixed perfusion defects (HR 0.41; P<.001). Such relationships underline STE ability to early identify HTx pts with subclinical myocardial dysfunction during long-term follow-up. © 2017, Wiley Periodicals, Inc.

  16. Bringing physiology into PET of the liver.

    Science.gov (United States)

    Keiding, Susanne

    2012-03-01

    Several physiologic features make interpretation of PET studies of liver physiology an exciting challenge. As with other organs, hepatic tracer kinetics using PET is quantified by dynamic recording of the liver after the administration of a radioactive tracer, with measurements of time-activity curves in the blood supply. However, the liver receives blood from both the portal vein and the hepatic artery, with the peak of the portal vein time-activity curve being delayed and dispersed compared with that of the hepatic artery. The use of a flow-weighted dual-input time-activity curve is of importance for the estimation of hepatic blood perfusion through initial dynamic PET recording. The portal vein is inaccessible in humans, and methods of estimating the dual-input time-activity curve without portal vein measurements are being developed. Such methods are used to estimate regional hepatic blood perfusion, for example, by means of the initial part of a dynamic (18)F-FDG PET/CT recording. Later, steady-state hepatic metabolism can be assessed using only the arterial input, provided that neither the tracer nor its metabolites are irreversibly trapped in the prehepatic splanchnic area within the acquisition period. This is used in studies of regulation of hepatic metabolism of, for example, (18)F-FDG and (11)C-palmitate.

  17. Myocardial perfusion imaging: Lessons learned and work to be done-update.

    Science.gov (United States)

    Iskandrian, Ami E; Dilsizian, Vasken; Garcia, Ernest V; Beanlands, Rob S; Cerqueira, Manuel; Soman, Prem; Berman, Daniel S; Cuocolo, Alberto; Einstein, Andrew J; Morgan, Charity J; Hage, Fadi G; Schelbert, Heinrich R; Bax, Jeroen J; Wu, Joseph C; Shaw, Leslee J; Sadeghi, Mehran M; Tamaki, Nagara; Kaufmann, Philipp A; Gropler, Robert; Dorbala, Sharmila; Van Decker, William

    2018-02-01

    As the second term of our commitment to Journal begins, we, the editors, would like to reflect on a few topics that have relevance today. These include prognostication and paradigm shifts; Serial testing: How to handle data? Is the change in perfusion predictive of outcome and which one? Ischemia-guided therapy: fractional flow reserve vs perfusion vs myocardial blood flow; positron emission tomography (PET) imaging using Rubidium-82 vs N-13 ammonia vs F-18 Flurpiridaz; How to differentiate microvascular disease from 3-vessel disease by PET? The imaging scene outside the United States, what are the differences and similarities? Radiation exposure; Special issues with the new cameras? Is attenuation correction needed? Are there normal databases and are these specific to each camera system? And finally, hybrid imaging with single-photon emission tomography or PET combined with computed tomography angiography or coronary calcium score. We hope these topics are of interest to our readers.

  18. Perfusion based cell culture chips

    DEFF Research Database (Denmark)

    Heiskanen, Arto; Emnéus, Jenny; Dufva, Martin

    2010-01-01

    Performing cell culture in miniaturized perfusion chambers gives possibilities to experiment with cells under near in vivo like conditions. In contrast to traditional batch cultures, miniaturized perfusion systems provide precise control of medium composition, long term unattended cultures...... and tissue like structuring of the cultures. However, as this chapter illustrates, many issues remain to be identified regarding perfusion cell culture such as design, material choice and how to use these systems before they will be widespread amongst biomedical researchers....

  19. Potential for PET scanning as an aid to heat transfer modeling

    International Nuclear Information System (INIS)

    Samulski, T.V.; Harris, C.; Winget, J.M.; Dewhirst, M.W.

    1987-01-01

    Positron Emission Tomography (PET) using /sup 68/Ga labelled microspheres (15μ diam.) for quantitative imaging of perfusion is being investigated for its potential to aid in verification of parameter estimation techniques. Such techniques have been used in bioheat transfer modeling where direct measurement of perfusion has not been possible. Perfusion is needed, to utilize bioheat transfer to predict temperatures between measured points during hyperthermia therapy. A preliminary study showing that PET could be used for verification of parameter estimation was done by heating a melanoma in a dog in which multiple thermometry catheters were placed in a central plane. Microspheres were injected at the end of a one hour heat treatment session before power down. CT and PET images of the same plane were aligned so that relative counts/pixel in 2 cm regions of interest of the PET image were measured along several catheter tracks. In all tracks measured an inverse correlation was shown between relative perfusion and temperature along the catheter during thermal steady state. These data strongly imply that PET scans obtained in the manner described bear relevance to bioheat transfer and for verification of perfusion in heated tissues as estimated by heat transfer modeling

  20. Multiparametric evaluation by simultaneous PET-MRI examination in patients with histologically proven laryngeal cancer.

    Science.gov (United States)

    Cavaliere, Carlo; Romeo, Valeria; Aiello, Marco; Mesolella, Massimo; Iorio, Brigida; Barbuto, Luigi; Cantone, Elena; Nicolai, Emanuele; Covello, Mario

    2017-03-01

    To evaluate the relationship between metabolic 18Fluoro-Deoxyglucose-Positron Emission Tomography (18FDG/PET) and morpho-functional parameters derived by Magnetic Resonance Imaging (MRI) in patients with histologically proven laryngeal cancer. To assess the clinical impact of PET/MRI examination on patient's staging and treatment planning. 16 patients with histologically proven laryngeal cancer were enrolled and underwent whole body PET/CT followed by a dedicated PET/MRI of the head/neck region. Data were separately evaluated by two blinded groups: metabolic (SUV and MTV), diffusion (ADC) and perfusion (K trans , V e , k ep and iAUC) maps were obtained by positioning regions of interest (ROIs). Tumoral local extension assessed on PET/MRI was compared to endoscopic findings. A good inter-observer agreement was found in anatomical location and local extension of PET/MRI lesions (Cohen's kappa 0.9). PET/CT SUV measures highly correlate with ones derived by PET/MRI (e.g., p=0.96 for measures on VOI). Significant correlations among metabolic, diffusion and perfusion parameters have been detected. PET/MRI had a relevant clinical impact, confirming endoscopic findings (6 cases), helping treatment planning (9 cases), and modifying endoscopic primary staging (1 case). PET/MRI is useful for primary staging of laryngeal cancer, allowing simultaneous collection of metabolic and functional data and conditioning the therapeutic strategies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. An update on technical and methodological aspects for cardiac PET applications

    International Nuclear Information System (INIS)

    PRESOTTO, Luca; BUSNARDO, Elena; GIANOLLI, Luigi; BETTINARDI, Valentino

    2016-01-01

    Positron emission tomography (PET) is indicated for a large number of cardiac diseases: perfusion and viability studies are commonly used to evaluate coronary artery disease; PET can also be used to assess sarcoidosis and endocarditis, as well as to investigate amyloidosis. Furthermore, a hot topic for research is plaque characterization. Most of these studies are technically very challenging. High count rates and short acquisition times characterize perfusion scans while very small targets have to be imaged in inflammation/infection and plaques examinations. Furthermore, cardiac PET suffers from respiratory and cardiac motion blur. Each type of studies has specific requirements from the technical and methodological point of view, thus PET systems with overall high performances are required. Furthermore, in the era of hybrid PET/computed tomography (CT) and PET/Magnetic Resonance Imaging (MRI) systems, the combination of complementary functional and anatomical information can be used to improve diagnosis and prognosis. Moreover, PET images can be qualitatively and quantitatively improved exploiting information from the other modality, using advanced algorithms. In this review we will report the latest technological and methodological innovations for PET cardiac applications, with particular reference to the state of the art of the hybrid PET/CT and PET/MRI. We will also report the most recent advancements in software, from reconstruction algorithms to image processing and analysis programs.

  2. Gammagraphy of cerebral perfusion

    International Nuclear Information System (INIS)

    Vazquez, Silvia

    2003-01-01

    Important aspects of the gammagraphy of cerebral perfusion and the diverse clinical applications in the neurological diseases are comment in this article. We focus in the usefulness of the photon emission cerebral tomography (SPECT) and its capacity to cross the hemato encephalic barrier through the use of radiopharmacons like 99 mTc-H M-PAO and 99mTc-EDC, thus managing to offer functional data on the captantes neurons of the radiopharmacon. The clinical applications of SPECT are studied; cerebrovascular disease, transient ischemic attacks, dementias, Alzheimer disease, as well as other neurological diseases are referred. (The author)

  3. Correlation of intra-tumor 18F-FDG uptake heterogeneity indices with perfusion CT derived parameters in colorectal cancer.

    Science.gov (United States)

    Tixier, Florent; Groves, Ashley M; Goh, Vicky; Hatt, Mathieu; Ingrand, Pierre; Le Rest, Catherine Cheze; Visvikis, Dimitris

    2014-01-01

    Thirty patients with proven colorectal cancer prospectively underwent integrated 18F-FDG PET/DCE-CT to assess the metabolic-flow phenotype. Both CT blood flow parametric maps and PET images were analyzed. Correlations between PET heterogeneity and perfusion CT were assessed by Spearman's rank correlation analysis. Blood flow visualization provided by DCE-CT images was significantly correlated with 18F-FDG PET metabolically active tumor volume as well as with uptake heterogeneity for patients with stage III/IV tumors (|ρ|:0.66 to 0.78; p-valueheterogeneity of 18F-FDG PET accumulation reflects to some extent tracer distribution and consequently indicates that 18F-FDG PET intra-tumor heterogeneity may be associated with physiological processes such as tumor vascularization.

  4. Healthy Pets and People

    Science.gov (United States)

    ... prevent the spread of germs between pets and people. Keep pets and their supplies out of the kitchen, and ... a local wildlife rehabilitation facility. More Information Healthy Pets Healthy People Clean Hands Save Lives! Stay Healthy at Animal ...

  5. Simultaneous acquisition of dynamic PET-MRI: arterial input function using DSC-MRI and [18F]-FET

    Energy Technology Data Exchange (ETDEWEB)

    Caldeira, Liliana; Yun, Seong Dae; Silva, Nuno da; Filss, Christian; Scheins, Juergen; Telmann, Lutz; Herzog, Hans; Shah, Jon [Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich GmbH (Germany)

    2015-05-18

    This work focuses on the study of simultaneous dynamic MR-PET acquisition in brain tumour patients. MR-based perfusion-weighted imaging (PWI) and PET [18F]-FET are dynamic methods, which allow to evaluate tumour metabolism in a quantitative way. In both methods, arterial input function (AIF) is necessary for quantification. However, the AIF estimation is a challenging task. In this work, we explore the possibilities to combine dynamic MR and PET AIF.

  6. Simultaneous acquisition of dynamic PET-MRI: arterial input function using DSC-MRI and [18F]-FET

    International Nuclear Information System (INIS)

    Caldeira, Liliana; Yun, Seong Dae; Silva, Nuno da; Filss, Christian; Scheins, Juergen; Telmann, Lutz; Herzog, Hans; Shah, Jon

    2015-01-01

    This work focuses on the study of simultaneous dynamic MR-PET acquisition in brain tumour patients. MR-based perfusion-weighted imaging (PWI) and PET [18F]-FET are dynamic methods, which allow to evaluate tumour metabolism in a quantitative way. In both methods, arterial input function (AIF) is necessary for quantification. However, the AIF estimation is a challenging task. In this work, we explore the possibilities to combine dynamic MR and PET AIF.

  7. Commercial software upgrades may significantly alter Perfusion CT parameter values in colorectal cancer

    International Nuclear Information System (INIS)

    Goh, Vicky; Shastry, Manu; Endozo, Raymondo; Groves, Ashley M.; Engledow, Alec; Peck, Jacqui; Reston, Jonathan; Wellsted, David M.; Rodriguez-Justo, Manuel; Taylor, Stuart A.; Halligan, Steve

    2011-01-01

    To determine how commercial software platform upgrades impact on derived parameters for colorectal cancer. Following ethical approval, 30 patients with suspected colorectal cancer underwent Perfusion CT using integrated 64 detector PET/CT before surgery. Analysis was performed using software based on modified distributed parameter analysis (Perfusion software version 4; Perfusion 4.0), then repeated using the previous version (Perfusion software version 3; Perfusion 3.0). Tumour blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were determined for identical regions-of-interest. Slice-by-slice and 'whole tumour' variance was assessed by Bland-Altman analysis. Mean BF, BV and PS was 20.4%, 59.5%, and 106% higher, and MTT 14.3% shorter for Perfusion 4.0 than Perfusion 3.0. The mean difference (95% limits of agreement) were +13.5 (-44.9 to 72.0), +2.61 (-0.06 to 5.28), -1.23 (-6.83 to 4.36), and +14.2 (-4.43 to 32.8) for BF, BV, MTT and PS respectively. Within subject coefficient of variation was 36.6%, 38.0%, 27.4% and 60.6% for BF, BV, MTT and PS respectively indicating moderate to poor agreement. Software version upgrades of the same software platform may result in significantly different parameter values, requiring adjustments for cross-version comparison. (orig.)

  8. Airborne particulate discriminator

    Science.gov (United States)

    Creek, Kathryn Louise [San Diego, CA; Castro, Alonso [Santa Fe, NM; Gray, Perry Clayton [Los Alamos, NM

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

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

    International Nuclear Information System (INIS)

    Qayyum, Abbas A.; Hasbak, Philip; Larsson, Henrik B.W.; Christensen, Thomas E.; Ghotbi, Adam A.; Mathiasen, Anders B.

    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 rest and adenosine stress imaging by 1.5-Tesla MR Scanner and a mCT/PET 64-slice Scanner. CMRI were analyzed based on Tikhonov's procedure of deconvolution without specifying an explicit compartment model using our own software. PET images were analyzed using standard clinical software. CMRI and PET data was compared with Spearman's rho and Bland–Altman analysis. Results: CMRI results were strongly and significantly correlated with PET results for the absolute global myocardial perfusion differences (r = 0.805, p = 0.001) and for global myocardial perfusion reserve (MPR) (r = 0.886, p < 0.001). At vessel territorial level, CMRI results were also significantly correlated with absolute PET myocardial perfusion differences (r = 0.737, p < 0.001) and MPR (r = 0.818, p < 0.001). Each vessel territory had similar strong correlation for absolute myocardial perfusion differences (right coronary artery (RCA): r = 0.787, p = 0.001; left anterior descending artery (LAD): r = 0.796, p = 0.001; left circumflex artery (LCX): r = 0.880, p < 0.001) and for MPR (RCA: r = 0.895, p < 0.001; LAD: r = 0.886, p < 0.001; LCX: r = 0.886, p < 0.001). Conclusion: On a global and vessel territorial basis, CMRI-measured absolute myocardial perfusion differences and MPR were strongly and significantly correlated with the Rb-82 PET findings

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

    Energy Technology Data Exchange (ETDEWEB)

    Qayyum, Abbas A., E-mail: abbas.ali.qayyum@regionh.dk [Department of Cardiology and Cardiac Catheterization Laboratory 2014, The Heart Centre, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Blegdamsvej 9, 2100 Copenhagen (Denmark); Hasbak, Philip, E-mail: philip.hasbak@regionh.dk [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Blegdamsvej 9, 2100 Copenhagen (Denmark); Larsson, Henrik B.W., E-mail: henrik.larsson@regionh.dk [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Blegdamsvej 9, 2100 Copenhagen (Denmark); Functional Imaging Unit, Diagnostic Department, Glostrup Hospital, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Ndr. Ringvej 57, 2600 Copenhagen (Denmark); Christensen, Thomas E., E-mail: thomas.emil.christensen@regionh.dk [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Blegdamsvej 9, 2100 Copenhagen (Denmark); Ghotbi, Adam A., E-mail: adam.ali.ghotbi@regionh.dk [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Blegdamsvej 9, 2100 Copenhagen (Denmark); Mathiasen, Anders B., E-mail: anders.b.mathiasen@gmail.com [Department of Cardiology and Cardiac Catheterization Laboratory 2014, The Heart Centre, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Blegdamsvej 9, 2100 Copenhagen (Denmark); and others

    2014-07-15

    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 rest and adenosine stress imaging by 1.5-Tesla MR Scanner and a mCT/PET 64-slice Scanner. CMRI were analyzed based on Tikhonov's procedure of deconvolution without specifying an explicit compartment model using our own software. PET images were analyzed using standard clinical software. CMRI and PET data was compared with Spearman's rho and Bland–Altman analysis. Results: CMRI results were strongly and significantly correlated with PET results for the absolute global myocardial perfusion differences (r = 0.805, p = 0.001) and for global myocardial perfusion reserve (MPR) (r = 0.886, p < 0.001). At vessel territorial level, CMRI results were also significantly correlated with absolute PET myocardial perfusion differences (r = 0.737, p < 0.001) and MPR (r = 0.818, p < 0.001). Each vessel territory had similar strong correlation for absolute myocardial perfusion differences (right coronary artery (RCA): r = 0.787, p = 0.001; left anterior descending artery (LAD): r = 0.796, p = 0.001; left circumflex artery (LCX): r = 0.880, p < 0.001) and for MPR (RCA: r = 0.895, p < 0.001; LAD: r = 0.886, p < 0.001; LCX: r = 0.886, p < 0.001). Conclusion: On a global and vessel territorial basis, CMRI-measured absolute myocardial perfusion differences and MPR were strongly and significantly correlated with the Rb-82 PET findings.

  11. Pet Problems at Home: Pet Problems in the Community.

    Science.gov (United States)

    Soltow, Willow

    1984-01-01

    Discusses problems of pets in the community, examining the community's role related to disruptive pets and pet overpopulation. Also discusses pet problems at home, offering advice on selecting a pet, meeting a pet's needs, and disciplining pets. Includes a list of books, films/filmstrips, teaching materials, and various instructional strategies.…

  12. Clinical Application of 18F-FDG PET in Epilepsy

    International Nuclear Information System (INIS)

    Kim, Yu Kyeong

    2008-01-01

    FDG PET has been used as a diagnostic tool for localization of seizure focus for last 2-3 decades. In this article, the clinical usefulness of FDG PET in the management of patients with epilepsy has been reviewed, which provided the evidences to justify the medicare reimbursement for FDG PET in management of patients with epilepsy. Literature review demonstrated that FDG PET provides an important information in localization of seizure focus and determination whether a patients is a surgical candidate or not. FDG PET has been reported to have high diagnostic performance in localization of seizure focus in neocortical epilepsy as well as temporal lobe epilepsy regardless of the presence of structural lesion on MRI. Particularly, FDG PET can provide the additional information when the results from standard diagnositic modality such as interictal or video-monitored EEG, and MRI are inconclusive or discordant, and make to avoid invasive study. Furthermore, the presence of hypometabolism and extent of metabolic extent has been reported as an important predictor for seizure free outcome. However, studies suggested that more accurate localization and better surgical outcome could be expected with multimodal approach by combination of EEG, MRI, and functional studies using FDG PET or perfusion SPECT rather than using a single diagnostic modality in management of patients with epilepsy. Complementary use of FDG PET in management of epilepsy is worth for good surgical outcome in epilepsy patients

  13. Perfusion CT in acute stroke

    International Nuclear Information System (INIS)

    Eckert, Bernd; Roether, Joachim; Fiehler, Jens; Thomalla, Goetz

    2015-01-01

    Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

  14. Placental perfusion - a human alternative

    DEFF Research Database (Denmark)

    Mose, Tina; Knudsen, Lisbeth E

    2006-01-01

    Foetal exposures to environmental and medicinal products have impact on the growth of the foetus (e.g. cigarette smoke) and development of organs (e.g. methylmercury and Thalidomide). Perfusion studies of the human term placenta enable investigation of placental transport of chemical substances...... between the mother and foetus. Dual perfusion of a single cotyledon in the human placenta can contribute to a better understanding of the placental barrier, transport rate and mechanisms of different substances and placental metabolism. The perfusion system has recently been established in Copenhagen...

  15. Multiparametric evaluation by simultaneous PET-MRI examination in patients with histologically proven laryngeal cancer

    International Nuclear Information System (INIS)

    Cavaliere, Carlo; Romeo, Valeria; Aiello, Marco; Mesolella, Massimo; Iorio, Brigida; Barbuto, Luigi; Cantone, Elena; Nicolai, Emanuele; Covello, Mario

    2017-01-01

    Highlights: • PET/MRI is feasible and useful for primary staging of laryngeal cancer. • PET/MRI simultaneously provides morphological, metabolic and functional parameters of tumoral laryngeal lesions. • PET/MRI allows an appropriate tumoral staging in terms of lesion extension with significant impact on therapeutic strategies. - Abstract: Objectives: To evaluate the relationship between metabolic 18Fluoro-Deoxyglucose-Positron Emission Tomography (18FDG/PET) and morpho-functional parameters derived by Magnetic Resonance Imaging (MRI) in patients with histologically proven laryngeal cancer. To assess the clinical impact of PET/MRI examination on patient’s staging and treatment planning. Methods: 16 patients with histologically proven laryngeal cancer were enrolled and underwent whole body PET/CT followed by a dedicated PET/MRI of the head/neck region. Data were separately evaluated by two blinded groups: metabolic (SUV and MTV), diffusion (ADC) and perfusion (K trans , V e , k ep and iAUC) maps were obtained by positioning regions of interest (ROIs). Tumoral local extension assessed on PET/MRI was compared to endoscopic findings. Results: A good inter-observer agreement was found in anatomical location and local extension of PET/MRI lesions (Cohen’s kappa 0.9). PET/CT SUV measures highly correlate with ones derived by PET/MRI (e.g., p = 0.96 for measures on VOI). Significant correlations among metabolic, diffusion and perfusion parameters have been detected. PET/MRI had a relevant clinical impact, confirming endoscopic findings (6 cases), helping treatment planning (9 cases), and modifying endoscopic primary staging (1 case). Conclusions: PET/MRI is useful for primary staging of laryngeal cancer, allowing simultaneous collection of metabolic and functional data and conditioning the therapeutic strategies.

  16. Multiparametric evaluation by simultaneous PET-MRI examination in patients with histologically proven laryngeal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cavaliere, Carlo [IRCCS SDN, Via E. Gianturco, 113-80143, Naples (Italy); Romeo, Valeria, E-mail: valeria.romeo@unina.it [Department of Advanced Biomedical Sciences, Federico II University, Naples (Italy); Aiello, Marco [IRCCS SDN, Via E. Gianturco, 113-80143, Naples (Italy); Mesolella, Massimo; Iorio, Brigida [Department of Neuroscience, Reproductive and Odontostomatologic Science, ENT Section, Federico II University, Naples (Italy); Barbuto, Luigi [Department of Advanced Biomedical Sciences, Federico II University, Naples (Italy); Cantone, Elena [Department of Neuroscience, Reproductive and Odontostomatologic Science, ENT Section, Federico II University, Naples (Italy); Nicolai, Emanuele; Covello, Mario [IRCCS SDN, Via E. Gianturco, 113-80143, Naples (Italy)

    2017-03-15

    Highlights: • PET/MRI is feasible and useful for primary staging of laryngeal cancer. • PET/MRI simultaneously provides morphological, metabolic and functional parameters of tumoral laryngeal lesions. • PET/MRI allows an appropriate tumoral staging in terms of lesion extension with significant impact on therapeutic strategies. - Abstract: Objectives: To evaluate the relationship between metabolic 18Fluoro-Deoxyglucose-Positron Emission Tomography (18FDG/PET) and morpho-functional parameters derived by Magnetic Resonance Imaging (MRI) in patients with histologically proven laryngeal cancer. To assess the clinical impact of PET/MRI examination on patient’s staging and treatment planning. Methods: 16 patients with histologically proven laryngeal cancer were enrolled and underwent whole body PET/CT followed by a dedicated PET/MRI of the head/neck region. Data were separately evaluated by two blinded groups: metabolic (SUV and MTV), diffusion (ADC) and perfusion (K{sub trans}, V{sub e}, k{sub ep} and iAUC) maps were obtained by positioning regions of interest (ROIs). Tumoral local extension assessed on PET/MRI was compared to endoscopic findings. Results: A good inter-observer agreement was found in anatomical location and local extension of PET/MRI lesions (Cohen’s kappa 0.9). PET/CT SUV measures highly correlate with ones derived by PET/MRI (e.g., p = 0.96 for measures on VOI). Significant correlations among metabolic, diffusion and perfusion parameters have been detected. PET/MRI had a relevant clinical impact, confirming endoscopic findings (6 cases), helping treatment planning (9 cases), and modifying endoscopic primary staging (1 case). Conclusions: PET/MRI is useful for primary staging of laryngeal cancer, allowing simultaneous collection of metabolic and functional data and conditioning the therapeutic strategies.

  17. Nuclear magnetic resonance of perfused tissue

    International Nuclear Information System (INIS)

    Harpen, M.D.; Allison, R.C.

    1986-01-01

    The effect of perfusion on the NMR signal observed in NMR imaging is studied in a phantom and in two isolated perfused canine lungs. It is observed that perfusion in tissue has little effect on longitudinal relaxation times. Transverse relaxation rates are observed to correlate linearly with rates of perfusion, in accordance with a model presented. (author)

  18. Brain PET scan

    Science.gov (United States)

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

  19. Quantitative lung perfusion evaluation using Fourier decomposition perfusion MRI.

    Science.gov (United States)

    Kjørstad, Åsmund; Corteville, Dominique M R; Fischer, Andre; Henzler, Thomas; Schmid-Bindert, Gerald; Zöllner, Frank G; Schad, Lothar R

    2014-08-01

    To quantitatively evaluate lung perfusion using Fourier decomposition perfusion MRI. The Fourier decomposition (FD) method is a noninvasive method for assessing ventilation- and perfusion-related information in the lungs, where the perfusion maps in particular have shown promise for clinical use. However, the perfusion maps are nonquantitative and dimensionless, making follow-ups and direct comparisons between patients difficult. We present an approach to obtain physically meaningful and quantifiable perfusion maps using the FD method. The standard FD perfusion images are quantified by comparing the partially blood-filled pixels in the lung parenchyma with the fully blood-filled pixels in the aorta. The percentage of blood in a pixel is then combined with the temporal information, yielding quantitative blood flow values. The values of 10 healthy volunteers are compared with SEEPAGE measurements which have shown high consistency with dynamic contrast enhanced-MRI. All pulmonary blood flow (PBF) values are within the expected range. The two methods are in good agreement (mean difference = 0.2 mL/min/100 mL, mean absolute difference = 11 mL/min/100 mL, mean PBF-FD = 150 mL/min/100 mL, mean PBF-SEEPAGE = 151 mL/min/100 mL). The Bland-Altman plot shows a good spread of values, indicating no systematic bias between the methods. Quantitative lung perfusion can be obtained using the Fourier Decomposition method combined with a small amount of postprocessing. Copyright © 2013 Wiley Periodicals, Inc.

  20. Quantitative Myocardial Perfusion with Dynamic Contrast-Enhanced Imaging in MRI and CT: Theoretical Models and Current Implementation

    Directory of Open Access Journals (Sweden)

    G. J. Pelgrim

    2016-01-01

    Full Text Available Technological advances in magnetic resonance imaging (MRI and computed tomography (CT, including higher spatial and temporal resolution, have made the prospect of performing absolute myocardial perfusion quantification possible, previously only achievable with positron emission tomography (PET. This could facilitate integration of myocardial perfusion biomarkers into the current workup for coronary artery disease (CAD, as MRI and CT systems are more widely available than PET scanners. Cardiac PET scanning remains expensive and is restricted by the requirement of a nearby cyclotron. Clinical evidence is needed to demonstrate that MRI and CT have similar accuracy for myocardial perfusion quantification as PET. However, lack of standardization of acquisition protocols and tracer kinetic model selection complicates comparison between different studies and modalities. The aim of this overview is to provide insight into the different tracer kinetic models for quantitative myocardial perfusion analysis and to address typical implementation issues in MRI and CT. We compare different models based on their theoretical derivations and present the respective consequences for MRI and CT acquisition parameters, highlighting the interplay between tracer kinetic modeling and acquisition settings.

  1. Hepatic perfusion during hepatic artery infusion chemotherapy: Evaluation with perfusion CT and perfusion scintigraphy

    International Nuclear Information System (INIS)

    Miller, D.L.; Carrasquillo, J.A.; Lutz, R.J.; Chang, A.E.

    1989-01-01

    The standard method for the evaluation of hepatic perfusion during hepatic artery infusion (HAI) chemotherapy is planar hepatic artery perfusion scintigraphy (HAPS). Planar HAPS was performed with 2 mCi of [99mTc] macroaggregated albumin infused at 1 ml/min and compared with single photon emission CT (SPECT) HAPS and with a new study, CT performed during the slow injection of contrast material through the HAI catheter (HAI-CT). Thirteen patients underwent 16 HAI-CT studies, 14 planar HAPS studies, and 9 SPECT HAPS studies. In 13 of 14 studies (93%) HAI-CT and planar HAPS were in complete agreement as to the perfusion pattern of intrahepatic metastases and normal liver. In nine studies where all modalities were performed, the findings identified by HAI-CT and planar HAPS agreed in all cases, whereas the results of two SPECT scans disagreed with the other studies. With respect to perfusion of individual metastases, 14 of 14 HAI-CT studies, 12 of 13 planar HAPS studies, and 9 of 9 SPECT HAPS studies correctly demonstrated the perfusion status of individual lesions as indicated by the pattern of changes in tumor size determined on CT obtained before and after the perfusion studies. Hepatic artery infusion CT was superior for delineation of individual metastases, particularly small lesions, and for the evaluation of nonperfused portions of the liver. Planar HAPS detected extrahepatic perfusion in four patients, and this was not detected by HAI-CT. We conclude that HAI-CT and scintigraphy are complementary techniques. Hepatic artery infusion CT has advantages for the evaluation of intrahepatic perfusion, and planar HAPS is superior to HAI-CT for the detection of extrahepatic perfusion

  2. Quantitative myocardial blood flow imaging with integrated time-of-flight PET-MR.

    Science.gov (United States)

    Kero, Tanja; Nordström, Jonny; Harms, Hendrik J; Sörensen, Jens; Ahlström, Håkan; Lubberink, Mark

    2017-12-01

    The use of integrated PET-MR offers new opportunities for comprehensive assessment of cardiac morphology and function. However, little is known on the quantitative accuracy of cardiac PET imaging with integrated time-of-flight PET-MR. The aim of the present work was to validate the GE Signa PET-MR scanner for quantitative cardiac PET perfusion imaging. Eleven patients (nine male; mean age 59 years; range 46-74 years) with known or suspected coronary artery disease underwent 15 O-water PET scans at rest and during adenosine-induced hyperaemia on a GE Discovery ST PET-CT and a GE Signa PET-MR scanner. PET-MR images were reconstructed using settings recommended by the manufacturer, including time-of-flight (TOF). Data were analysed semi-automatically using Cardiac VUer software, resulting in both parametric myocardial blood flow (MBF) images and segment-based MBF values. Correlation and agreement between PET-CT-based and PET-MR-based MBF values for all three coronary artery territories were assessed using regression analysis and intra-class correlation coefficients (ICC). In addition to the cardiac PET-MR reconstruction protocol as recommended by the manufacturer, comparisons were made using a PET-CT resolution-matched reconstruction protocol both without and with TOF to assess the effect of time-of-flight and reconstruction parameters on quantitative MBF values. Stress MBF data from one patient was excluded due to movement during the PET-CT scanning. Mean MBF values at rest and stress were (0.92 ± 0.12) and (2.74 ± 1.37) mL/g/min for PET-CT and (0.90 ± 0.23) and (2.65 ± 1.15) mL/g/min for PET-MR (p = 0.33 and p = 0.74). ICC between PET-CT-based and PET-MR-based regional MBF was 0.98. Image quality was improved with PET-MR as compared to PET-CT. ICC between PET-MR-based regional MBF with and without TOF and using different filter and reconstruction settings was 1.00. PET-MR-based MBF values correlated well with PET-CT-based MBF values and

  3. Generator-produced rubidium-82 positron emission tomography myocardial perfusion imaging. From basic aspects to clinical applications

    International Nuclear Information System (INIS)

    Yoshinaga, Keiichiro; Klein, R.; Tamaki, Nagara

    2010-01-01

    Cardiovascular disease is the leading cause of death in modern industrialized countries with an aging population. This fact has fueled the need for innovative diagnostic testing intended to improve coronary artery disease (CAD) patient care. Detection of myocardial ischemia using myocardial perfusion imaging (MPI) plays an important role for CAD diagnosis and the prediction of future risk of cardiovascular events. Positron emission tomography (PET) MPI has high diagnostic accuracy and can estimate regional myocardial blood flow (MBF) in patients with CAD. Rubidium-82 ( 82 Rb) is a generator-produced PET myocardial perfusion tracer and has been widely used in North America in clinical practice. 82 Rb PET has recently become available in some cardiovascular centers in Europe and Japan. Clinical trials are expected in both regions. 82 Rb PET has high diagnostic accuracy and recent data have shown its prognostic value. Thus, 82 Rb PET would greatly contribute to CAD patients' care. 82 Rb PET can also be used to quantify MBF. This review describes the current status of 82 Rb MPI from basic principles to clinical implications. This paper also highlights the recent development of MBF quantification using 82 Rb PET. (author)

  4. Combined functional CT/FDG-PET: demonstrates reduced hepatic phosphorylation of glucose in advanced colorectal cancer

    International Nuclear Information System (INIS)

    Miles, K.A.; Keith, C.J.; Griffiths, M.R.; Fuentes, M.; Bunce, I.

    2002-01-01

    Full text: This study describes a technique to quantify hepatic glucose phosphorylation using combined data from functional CT and FDG-PET and assesses the differences in phosphorylation between patients with either early or advanced colorectal cancer. Functional CT and FDG-PET were utilised to obtain measurements of perfusion and glucose uptake respectively within the livers of a series of 35 patients with colorectal cancer. Patients with PET evidence of extrahepatic tumour were considered to have advanced disease. The net influx constant (Ki) for FDG was determined from the liver SUV. CT measurements of hepatic perfusion were incorporated into FDG kinetic analysis to determine hepatic glucose phosphorylation fraction. SUV and Ki were significantly lower in the 12 patients with advanced disease (p=0.015 and p=0.013 respectively) whereas portal and total hepatic perfusion were increased (p=0.013 and p=0.008 respectively). Combining the PET and CT data yielded phosphorylation fractions of 1.14% and 0.74% for early and advanced disease respectively (p=0.002). Hepatic glucose phosphorylation can be determined by combining functional CT measurements of perfusion with PET measurements of FDG and is significantly reduced in patients with more advanced malignancy. Reduced hepatic glucose phosphorylation may be an important mechanism in the development of cancer cachexia. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  5. Combined functional CT/FDG-PET: demonstrates reduced hepatic phosphorylation of glucose in advanced colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Miles, K A [Southernex Imaging Group, QLD (Australia); Queensland University of Technology, QLD (Australia); Keith, C J [Southernex Imaging Group, QLD (Australia); Wesley Research Institute, QLD (Australia); Griffiths, M R [Queensland University of Technology, QLD (Australia); Fuentes, M [Southernex Imaging Group, QLD (Australia); Bunce, I [Wesley Research Institute, QLD (Australia)

    2002-07-01

    Full text: This study describes a technique to quantify hepatic glucose phosphorylation using combined data from functional CT and FDG-PET and assesses the differences in phosphorylation between patients with either early or advanced colorectal cancer. Functional CT and FDG-PET were utilised to obtain measurements of perfusion and glucose uptake respectively within the livers of a series of 35 patients with colorectal cancer. Patients with PET evidence of extrahepatic tumour were considered to have advanced disease. The net influx constant (Ki) for FDG was determined from the liver SUV. CT measurements of hepatic perfusion were incorporated into FDG kinetic analysis to determine hepatic glucose phosphorylation fraction. SUV and Ki were significantly lower in the 12 patients with advanced disease (p=0.015 and p=0.013 respectively) whereas portal and total hepatic perfusion were increased (p=0.013 and p=0.008 respectively). Combining the PET and CT data yielded phosphorylation fractions of 1.14% and 0.74% for early and advanced disease respectively (p=0.002). Hepatic glucose phosphorylation can be determined by combining functional CT measurements of perfusion with PET measurements of FDG and is significantly reduced in patients with more advanced malignancy. Reduced hepatic glucose phosphorylation may be an important mechanism in the development of cancer cachexia. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc.

  6. Comparison between CT perfusion and Tc-99m ECD SPECT in the assessment of cerebrovascular reserve: a case study

    International Nuclear Information System (INIS)

    Crouch, J.; Wood, C.; Campbell, A.; McCarthy, M.; Dunne, M.; Bynevelt, M.; Lenzo, N.

    2003-01-01

    Full text: Brain perfusion is sensitively assessed by cerebral SPECT imaging utilising perfusion agents such as Tc-99m HMPAO and Tc-99m ethyl cysteinate dimer (ECD). Positron emission tomography can accurately assess and quantify brain perfusion and MRI can also be used for perfusion assessment. Both MRI and PET however are currently limited by cost and availability. A new technique utilising CT with contrast has been developed to assess and quantitate cerebral perfusion. The technique utilises arterial input information and deconvolution analysis to develop quantifiable measures of perfusion and contrast transit. The technique has been validated for acute stroke assessment and is being assessed for other possible applications. We present a case study comparison of this technique with cerebral SPECT perfusion using Tc-99m ECD in the assessment of cerebrovasular reserve. In each case, the CT and SPECT studies were performed pre- and post-acetazolamide and the SPECT study was statistically compared with a normal database utilising an automated brain perfusion statistical analysis package (NeurostatT). We discuss the correlation found between techniques, their strengths, weaknesses and possible future roles. Copyright (2003) The Australian and New Zealand Society of Nuclear Medicine Inc

  7. Hydrostatic determinants of cerebral perfusion

    International Nuclear Information System (INIS)

    Wagner, E.M.; Traystman, R.J.

    1986-01-01

    We examined the cerebral blood flow response to alterations in perfusion pressure mediated through decreases in mean arterial pressure, increases in cerebrospinal fluid (CSF) pressure, and increases in jugular venous (JV) pressure in 42 pentobarbital anesthetized dogs. Each of these three pressures was independently controlled. Cerebral perfusion pressure was defined as mean arterial pressure minus JV or CSF pressure, depending on which was greater. Mean hemispheric blood flow was measured with the radiolabeled microsphere technique. Despite 30-mm Hg reductions in mean arterial pressure or increases in CSF or JV pressure, CBF did not change as long as the perfusion pressure remained greater than approximately 60 mm Hg. However, whenever perfusion pressure was reduced to an average of 48 mm Hg, cerebral blood flow decreased 27% to 33%. These results demonstrate the capacity of the cerebral vascular bed to respond similarly to changes in the perfusion pressure gradient obtained by decreasing mean arterial pressure, increasing JV pressure or increasing CSF pressure, and thereby support the above definition of cerebral perfusion pressure

  8. PET reconstruction

    International Nuclear Information System (INIS)

    O'Sullivan, F.; Pawitan, Y.; Harrison, R.L.; Lewellen, T.K.

    1990-01-01

    In statistical terms, filtered backprojection can be viewed as smoothed Least Squares (LS). In this paper, the authors report on improvement in LS resolution by: incorporating locally adaptive smoothers, imposing positivity and using statistical methods for optimal selection of the resolution parameter. The resulting algorithm has high computational efficiency relative to more elaborate Maximum Likelihood (ML) type techniques (i.e. EM with sieves). Practical aspects of the procedure are discussed in the context of PET and illustrations with computer simulated and real tomograph data are presented. The relative recovery coefficients for a 9mm sphere in a computer simulated hot-spot phantom range from .3 to .6 when the number of counts ranges from 10,000 to 640,000 respectively. The authors will also present results illustrating the relative efficacy of ML and LS reconstruction techniques

  9. Fractal analysis in radiological and nuclear medicine perfusion imaging: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Michallek, Florian; Dewey, Marc [Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Charite - Universitaetsmedizin Berlin, Medical School, Department of Radiology, Berlin (Germany)

    2014-01-15

    To provide an overview of recent research in fractal analysis of tissue perfusion imaging, using standard radiological and nuclear medicine imaging techniques including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) and to discuss implications for different fields of application. A systematic review of fractal analysis for tissue perfusion imaging was performed by searching the databases MEDLINE (via PubMed), EMBASE (via Ovid) and ISI Web of Science. Thirty-seven eligible studies were identified. Fractal analysis was performed on perfusion imaging of tumours, lung, myocardium, kidney, skeletal muscle and cerebral diseases. Clinically, different aspects of tumour perfusion and cerebral diseases were successfully evaluated including detection and classification. In physiological settings, it was shown that perfusion under different conditions and in various organs can be properly described using fractal analysis. Fractal analysis is a suitable method for quantifying heterogeneity from radiological and nuclear medicine perfusion images under a variety of conditions and in different organs. Further research is required to exploit physiologically proven fractal behaviour in the clinical setting. (orig.)

  10. Fractal analysis in radiological and nuclear medicine perfusion imaging: a systematic review

    International Nuclear Information System (INIS)

    Michallek, Florian; Dewey, Marc

    2014-01-01

    To provide an overview of recent research in fractal analysis of tissue perfusion imaging, using standard radiological and nuclear medicine imaging techniques including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) and to discuss implications for different fields of application. A systematic review of fractal analysis for tissue perfusion imaging was performed by searching the databases MEDLINE (via PubMed), EMBASE (via Ovid) and ISI Web of Science. Thirty-seven eligible studies were identified. Fractal analysis was performed on perfusion imaging of tumours, lung, myocardium, kidney, skeletal muscle and cerebral diseases. Clinically, different aspects of tumour perfusion and cerebral diseases were successfully evaluated including detection and classification. In physiological settings, it was shown that perfusion under different conditions and in various organs can be properly described using fractal analysis. Fractal analysis is a suitable method for quantifying heterogeneity from radiological and nuclear medicine perfusion images under a variety of conditions and in different organs. Further research is required to exploit physiologically proven fractal behaviour in the clinical setting. (orig.)

  11. Imaging and PET - PET/CT imaging

    International Nuclear Information System (INIS)

    Von Schulthess, G.K.; Hany, Th.F.

    2008-01-01

    PET/CT has grown because the lack of anatomic landmarks in PET makes 'hardware-fusion' to anatomic cross-sectional data extremely useful. Addition of CT to PET improves specificity, but also sensitivity, and adding PET to CT adds sensitivity and specificity in tumor imaging. The synergistic advantage of adding CT is that the attenuation correction needed for PET data can also be derived from the CT data. This makes PET-CT 25-30% faster than PET alone, leading to higher patient throughput and a more comfortable examination for patients typically lasting 20 minutes or less. FDG-PET-CT appears to provide relevant information in the staging and therapy monitoring of many tumors, such as lung carcinoma, colorectal cancer, lymphoma, gynaecological cancers, melanoma and many others, with the notable exception of prostatic cancer. for this cancer, choline derivatives may possibly become useful radiopharmaceuticals. The published literature on the applications of FDG-PET-CT in oncology is still limited but several designed studies have demonstrated the benefits of PET-CT. (authors)

  12. Cerebral perfusion gammagraphy in neurology and neurosurgery

    International Nuclear Information System (INIS)

    Cardenas, Rene; Duran de Cardenas, Rosalia

    1998-01-01

    This paper describes six methods for measuring rCBF: 1) PET through 77 Kr, 15 O-water, 18 F-antipirine, 18 F-methane and 11 C-alcohols, 2) Wash measure of 133 Xe through SPECT or multidetectors, 3) CT contrasted through xenon, 4) planar gammagraphy or SPECT through 123 I-IMP or 123 I-HIPDM, 5) planar gammagraphy or radioisotopic tomography (SPECT) through 201 Tl-dietiltiocarbamate, and 6) planar gammagraphy or SPECT through 99m Tc lipofilics complex, 99m Tc-HMPAO and 99m Tc-ECD. They have been used for rCBF, , 133 Xe, 123 I-IMP 99m Tc-HMPAO studies, the two last ones are been used at the moment, the film performance is around 0.7 to 1.1 cm. The most useful radioisotopic techniques for gammagraphic study of cerebral perfusion have used HMPAO and 131 I-IMP labelled with 99m Tc

  13. Trends in PET imaging

    International Nuclear Information System (INIS)

    Moses, William W.

    2000-01-01

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

  14. Dynamic MR cardiac perfusion studies in patients with acquired heart diseases

    International Nuclear Information System (INIS)

    Finelli, D.A.; Adler, L.P.; Paschal, C.B.; Haacke, E.M.

    1990-01-01

    The combination of ultrafast scanning techniques with contrast administration has opened new venues for MR imaging relating to the physiology of organ perfusion. Regional cardiac perfusion determinations lend important additional information to the morphologic and functional data provided by conventional cardiac MR imaging. The authors of this paper studied 10 patients with acquired heart diseases, including ischemic heart disease, cardiomyopathy, ventricular hypertrophy, and cardiac tumor, using conventional spin-echo imaging, cine gradient-echo imaging, and dynamic Gd-DTPA--enhanced perfusion imaging with an ultrafast, inversion-recovery, Turbo-fast low-angle shot sequence. This technique enables analysis of the first pass and early biodistribution phases following contrast administration, information that has been correlated with cardiac catheterization, single photo emission CT (SPECT), and administration emission tomographic (PET) data

  15. PET / MRI vs. PET / CT. Indications Oncology

    International Nuclear Information System (INIS)

    Oliva González, Juan P.

    2016-01-01

    Hybrid techniques in Nuclear Medicine is currently a field in full development for diagnosis and treatment of various medical conditions. With the recent advent of PET / MRI much it speculated about whether or not it is superior to PET / CT especially in oncology. The Conference seeks to clarify this situation by dealing issues such as: State of the art technology PET / MRI; Indications Oncology; Some clinical cases. It concludes by explaining the oncological indications of both the real and current situation of the PET / MRI. (author)

  16. Biological characterization of F-18-labeled rhodamine B, a potential positron emission tomography perfusion tracer.

    Science.gov (United States)

    Bartholomä, Mark D; He, Huamei; Pacak, Christina A; Dunning, Patricia; Fahey, Frederic H; McGowan, Francis X; Cowan, Douglas B; Treves, S Ted; Packard, Alan B

    2013-11-01

    Myocardial infarction is the leading cause of death in western countries, and positron emission tomography (PET) plays an increasing role in the diagnosis and treatment planning for this disease. However, the absence of an (18)F-labeled PET myocardial perfusion tracer hampers the widespread use of PET in myocardial perfusion imaging (MPI). We recently reported a potential MPI agent based on (18)F-labeled rhodamine B. The goal of this study was to more completely define the biological properties of (18)F-labeled rhodamine B with respect to uptake and localization in an animal model of myocardial infarction and to evaluate the uptake (18)F-labeled rhodamine B by cardiomyocytes. A total of 12 female Sprague Dawley rats with a permanent ligation of the left anterior descending artery (LAD) were studied with small-animal PET. The animals were injected with 100-150 μCi of (18)F-labeled rhodamine B diethylene glycol ester ([(18)F]RhoBDEGF) and imaged two days before ligation. The animals were imaged again two to ten days post-ligation. After the post-surgery scans, the animals were euthanized and the hearts were sectioned into 1mm slices and myocardial infarct size was determined by phosphorimaging and 2,3,5-triphenyltetrazolium chloride staining (TTC). In addition, the uptake of [(18)F]RhoBDEGF in isolated rat neonatal cardiomyocytes was determined by fluorescence microscopy. Small-animal PET showed intense and uniform uptake of [(18)F]RhoBDEGF throughout the myocardium in healthy rats. After LAD ligation, well defined perfusion defects were observed in the PET images. The defect size was highly correlated with the infarct size as determined ex vivo by phosphorimaging and TTC staining. In vitro, [(18)F]RhoBDEGF was rapidly internalized into rat cardiomyocytes with ~40 % of the initial activity internalized within the 60 min incubation time. Fluorescence microscopy clearly demonstrated localization of [(18)F]RhoBDEGF in the mitochondria of rat cardiomyocytes. Fluorine-18

  17. Biological characterization of F-18-labeled rhodamine B, a potential positron emission tomography perfusion tracer

    International Nuclear Information System (INIS)

    Bartholomä, Mark D.; He, Huamei; Pacak, Christina A.; Dunning, Patricia; Fahey, Frederic H.; McGowan, Francis X.; Cowan, Douglas B.; Treves, S. Ted; Packard, Alan B.

    2013-01-01

    Introduction: Myocardial infarction is the leading cause of death in western countries, and positron emission tomography (PET) plays an increasing role in the diagnosis and treatment planning for this disease. However, the absence of an 18 F-labeled PET myocardial perfusion tracer hampers the widespread use of PET in myocardial perfusion imaging (MPI). We recently reported a potential MPI agent based on 18 F-labeled rhodamine B. The goal of this study was to more completely define the biological properties of 18 F-labeled rhodamine B with respect to uptake and localization in an animal model of myocardial infarction and to evaluate the uptake 18 F-labeled rhodamine B by cardiomyocytes. Methods: A total of 12 female Sprague Dawley rats with a permanent ligation of the left anterior descending artery (LAD) were studied with small-animal PET. The animals were injected with 100–150 μCi of 18 F-labeled rhodamine B diethylene glycol ester ([ 18 F]RhoBDEGF) and imaged two days before ligation. The animals were imaged again two to ten days post-ligation. After the post-surgery scans, the animals were euthanized and the hearts were sectioned into 1 mm slices and myocardial infarct size was determined by phosphorimaging and 2,3,5-triphenyltetrazolium chloride staining (TTC). In addition, the uptake of [ 18 F]RhoBDEGF in isolated rat neonatal cardiomyocytes was determined by fluorescence microscopy. Results: Small-animal PET showed intense and uniform uptake of [ 18 F]RhoBDEGF throughout the myocardium in healthy rats. After LAD ligation, well defined perfusion defects were observed in the PET images. The defect size was highly correlated with the infarct size as determined ex vivo by phosphorimaging and TTC staining. In vitro, [ 18 F]RhoBDEGF was rapidly internalized into rat cardiomyocytes with ∼ 40 % of the initial activity internalized within the 60 min incubation time. Fluorescence microscopy clearly demonstrated localization of [ 18 F]RhoBDEGF in the mitochondria

  18. Characterization of particulate amines

    International Nuclear Information System (INIS)

    Gundel, L.A.; Chang, S.G.; Clemenson, M.S.; Markowitz, S.S.; Novakov, T.

    1979-01-01

    The reduced nitrogen compounds associated with ambient particulate matter are chemically characterized by means of ESCA and proton activation analysis. Ambient particulate samples collected on silver filters in Berkeley, California were washed with water and organic solvents, and ESCA and proton activation analysis were performed in order to determine the composition of various nitrogen compounds and the total nitrogen content. It is found that 85% of the amines originally present in ambient particulate matter can be removed by water extraction, whereas the ammonium and nitrate are completely removed. An observed increase in ammonium ion in the extract, compared with its concentration in the original sample, coupled with the commensurate decrease in amine concentration, is attributed to the hydrolysis of amide groups, which may cause analytical methods based on extraction to yield erroneous results

  19. Microwave regenerated particulate trap

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, A.C. Jr.; Yonushonis, T.M. [Cummins Engine Co., Inc., Columbus, IN (United States); Haberkamp, W.C.; Mako, F.; Len, L.K,; Silberglitt, R.; Ahmed, I. [FM Technologies, Inc., Fairfax, VA (United States)

    1997-12-31

    It has been demonstrated that a fibrous particulate filter can extract particulate matter from the diesel exhaust. However, additional engineering efforts remains to achieve the design target of 90%. It has also be shown that with minor modifications magnetrons produced for home ovens can endure a simulated diesel operating environment. Much work remains to develop a robust product ready to complete extensive engine testing and evaluation. These efforts include: (1) additional environmental testing of magnetrons; (2) vibration testing of the filter in the housing; (3) evaluating alternative methods/designs to seal the center bore; and (4) determining the optimum coating thickness that provides sufficient structural integrity while maintaining rapid heating rates.

  20. Pets and Parasites

    Science.gov (United States)

    ... good news is that this rarely happens. Most pet-to-people diseases can be avoided by following a few ... your doctor Can a parasite cause death in people and pets? Can human disease from a parasite be treated ...

  1. Heart PET scan

    Science.gov (United States)

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

  2. [Principles of PET].

    Science.gov (United States)

    Beuthien-Baumann, B

    2018-05-01

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

  3. Dynamic CT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

    2016-01-01

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  4. Dynamic CT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

    2016-10-15

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  5. Lung perfusion scintigraphy by SPECT

    International Nuclear Information System (INIS)

    Hirayama, Takanobu

    1990-01-01

    The initial study reports the characteristic performance using lung segmental phantom filled in Tc-99m pertechnetate. To evaluate the segmental defect in lung perfusion scintigraphy, we applied Bull's-eye analysis in addition to planar image set. Bull's-eye analysis especially facilitated the interpretation in both middle and lower lobes. Subsequently, to evolute the clinical application of Bull's-eye analysis, pulmonary scintigraphy was performed on 10 normal subjects and 60 patients with several pulmonary diseases. Of interest, Bull's-eye analysis, however, encouraged the interpretation in both lower lobes. To calculate the extention and severity of perfusion defect, the present study describes Bull's-eye analysis. Quantitative scoring showed higher in patients with lung cancer than those with pulmonary tuberculosis. The present study focus that Bull's-eye analysis can be useful for evaluating perfusion in patients with a couple of pulmonary diseases. (author)

  6. Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension : Insights from a multicenter registry

    NARCIS (Netherlands)

    Vliegenthart, Rozemarijn; De Cecco, Carlo N.; Wichmann, Julian L.; Meinel, Felix G.; Pelgrim, Gert Jan; Tesche, Christian; Ebersberger, Ullrich; Pugliese, Francesca; Bamberg, Fabian; Choe, Yeon Hyeon; Wang, Yining; Schoepf, U. Joseph

    2016-01-01

    Background: To identify patients with early signs of myocardial perfusion reduction, a reference base for perfusion measures is needed. Objective: To analyze perfusion parameters derived from dynamic computed tomography perfusion imaging (CTPI) in patients with suspected coronary artery disease

  7. Visual Assessment of Brain Perfusion MRI Scans in Dementia: A Pilot Study.

    Science.gov (United States)

    Fällmar, David; Lilja, Johan; Velickaite, Vilma; Danfors, Torsten; Lubberink, Mark; Ahlgren, André; van Osch, Matthias J P; Kilander, Lena; Larsson, Elna-Marie

    2016-05-01

    Functional imaging is becoming increasingly important for the detection of neurodegenerative disorders. Perfusion MRI with arterial spin labeling (ASL) has been reported to provide promising diagnostic possibilities but is not yet widely used in routine clinical work. The aim of this study was to compare, in a clinical setting, the visual assessment of subtracted ASL CBF maps with and without additional smoothing, to FDG-PET data. Ten patients with a clinical diagnosis of dementia and 11 age-matched cognitively healthy controls were examined with pseudo-continuous ASL (pCASL) and 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET). Three diagnostic physicians visually assessed the pCASL maps after subtraction only, and after postprocessing using Gaussian smoothing and GLM-based beta estimate functions. The assessment scores were compared to FDG PET values. Furthermore, the ability to discriminate patients from healthy elderly controls was assessed. Smoothing improved the correlation between visually assessed regional ASL perfusion scores and the FDG PET SUV-r values from the corresponding regions. However, subtracted pCASL maps discriminated patients from healthy controls better than smoothed maps. Smoothing increased the number of false-positive patient identifications. Application of beta estimate functions had only a marginal effect. Spatial smoothing of ASL images increased false positive results in the discrimination of hypoperfusion conditions from healthy elderly. It also decreased interreader agreement. However, regional characterization and subjective perception of image quality was improved. Copyright © 2015 by the American Society of Neuroimaging.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    International Nuclear Information System (INIS)

    Siva, Shankar; Hardcastle, Nicholas; Kron, Tomas; Bressel, Mathias; Callahan, Jason; MacManus, Michael P.; Shaw, Mark; Plumridge, Nikki; Hicks, Rodney J.; Steinfort, Daniel; Ball, David L.; Hofman, Michael S.

    2015-01-01

    Purpose: To investigate 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 2 =0.99, P<.01), with ventilation strongly negatively linear (r 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/CT imaging. These

  10. Automatic assessment of cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Stegmann, Mikkel Bille; Larsson, Henrik B.W.

    2004-01-01

    In this paper, a method based on Active Appearance Models (AAM) is applied for automatic registration of myocardial perfusion MRI. A semi-quantitative perfusion assessment of the registered image sequences is presented. This includes the formation of perfusion maps for three parameters; maximum up...

  11. Transient influence of end-tidal carbon dioxide tension on the postural restraint in cerebral perfusion

    DEFF Research Database (Denmark)

    Immink, R.V.; Truijen, J.; Secher, Niels H.

    2009-01-01

    In the upright position, cerebral blood flow is reduced, maybe because arterial carbon dioxide partial pressure (Pa(CO(2))) decreases. We evaluated the time-dependent influence of a reduction in Pa(CO(2)), as indicated by the end-tidal Pco(2) tension (Pet(CO(2))), on cerebral perfusion during head......-up tilt. Mean arterial pressure, cardiac output, middle cerebral artery mean flow velocity (MCA V(mean)), and dynamic cerebral autoregulation at supine rest and 70 degrees head-up tilt were determined during free breathing and with Pet(CO(2)) clamped to the supine level. The postural changes in central...... hemodynamic variables were equivalent, and the cerebrovascular autoregulatory capacity was not significantly affected by tilt or by clamping Pet(CO(2)). In the first minute of tilt, the decline in MCA V(mean) (10 +/- 4 vs. 3 +/- 4 cm/s; mean +/- SE; P

  12. SPECT and PET in cerebrovascular diseases. SPECT und PET bei cerebrovaskulaeren Erkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, W.H. (Herzzentrum Nordrhein-Westfalen, Bad Oeynhausen (Germany). Inst. fuer Nuklearmedizin)

    1993-02-01

    Investigations using recently emerged perfusion tracers for SPECT, Tc-99m-HMPAO in particular, and studies of local glucose metabolism and oxygen utilisation with PET have deepened our knowledge of the pathophysiology in development and in the sequel of stroke. Studies of local cerebral blood flow and cerebrovascular reserve capacity are indicated in case of neurological symptoms suspected to be caused by transient ischemic attacks or in case of significant narrowing of the cerebral arteries. PET investigations of local metabolism (at the present state) are indicated in patients with incompleted stroke or with infarction and extended ischemic border zone. The differential diagnosis between multi-infarct-dementia and primarily neurodegenerative dementias is facilitated, in some individuals, by the characteristic topography of reduced flow. (orig./MG).

  13. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    ... to stop eating (fast), be on a special diet, or take any medicines before the test. A chest x-ray is usually done before or after a ventilation and perfusion scan. You wear a hospital gown or comfortable clothing that does not have ...

  14. Strategies to reduce radiation dose in cardiac PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tung Hsin; Wu, Nien-Yun [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan (China); Wang, Shyh-Jen [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan (China); Wu, Jay [Institute of Radiological science, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Mok, Greta S.P. [Department of Electrical and Electronics Engineering, Faculty of Science and Technology, University of Macau, Macau (China); Yang, Ching-Ching, E-mail: g39220003@yahoo.com.tw [Department of Radiological Technology, Tzu Chi College of Technology, 880, Sec.2, Chien-kuo Rd. Hualien 970, Taiwan (China); Huang, Tzung-Chi, E-mail: tzungchi.huang@mail.cmu.edu.tw [Department of Biomedical Imaging and Radiological Science, China Medical University, No.91 Hsueh-Shih Road, Taichung 40402, Taiwan (China)

    2011-08-21

    Background: Our aim was to investigate CT dose reduction strategies on a hybrid PET/CT scanner for cardiac applications. Materials: Image quality and dose estimation of different CT scanning protocols for CT coronary angiography (CTCA), and CT-based attenuation correction for PET imaging were investigated. Fifteen patients underwent CTCA, perfusion PET imaging at rest and under stress, and FDG PET for myocardial viability. These patients were divided into three groups based on the CTCA technique performed: retrospectively gated helical (RGH), ECG tube current modulation (ETCM), and prospective gated axial (PGA) acquisitions. All emission images were corrected for photon attenuation using CT images obtained by default setting and an ultra-low dose CT (ULDCT) scan. Results: Radiation dose in RGH technique was 22.2{+-}4.0 mSv. It was reduced to 10.95{+-}0.82 and 4.13{+-}0.31 mSv using ETCM and PGA techniques, respectively. Radiation dose in CT transmission scan was reduced by 96.5% (from 4.53{+-}0.5 to 0.16{+-}0.01 mSv) when applying ULDCT as compared to the default CT. No significant difference in terms of image quality was found among various protocols. Conclusion: The proposed CT scanning strategies, i.e. ETCM or PGA for CTCA and ULDCT for PET attenuation correction, could reduce radiation dose up to 47% without degrading imaging quality in an integrated cardiac PET/CT coronary artery examination.

  15. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    Energy Technology Data Exchange (ETDEWEB)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K. [Department of Radiological Sciences, Guy' s, King' s and St. Thomas' School of Medicine, London (United Kingdom)

    1999-10-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  16. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    International Nuclear Information System (INIS)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K.

    1999-01-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  17. Contralateral thalamic hypoperfusion on brain perfusion SPECT

    International Nuclear Information System (INIS)

    Lee, Seok Mo; Bae, Sang Kyun; Yoo, Kyung Moo; Yum, Ha Yong

    2000-01-01

    Brain perfusion single photon emission computed tomography (SPECT) is useful for the localization of cerebrovascular lesion and sometimes reveals more definite lesion than radiologic imaging modality such as CT or MRI does. The purpose of this study was to evaluate the diagnostic usefulness of brain perfusion SPECT in patients with hemisensory impairment. Thirteen consecutive patients (M:F= 8:5, mean age = 48) who has hemisensory impairment were included. Brain perfusion SPECT was performed after intravenous injection of 1110 MBq of Tc-99m ECD. The images were obtained using a dual-head gamma camera with ultra-high resolution collimator. Semiquantitative analysis was performed after placing multiple ROIs on cerebral cortex, basal ganglia, thalamus and cerebellum. There were 10 patients with left hemisensory impairment and 3 patients with right-sided symptom. Only 2 patients revealed abnormal signal change in the thalamus on MRI. But brain perfusion SPECT showed decreased perfusion in the thalamus in 9 patients. Six patients among 10 patients with left hemisensory impairment revealed decreased perfusion in the contralateral thalamus on brain SPECT. The other 4 patients revealed no abnormality. Two patients among 3 patients with right hemisensory impairment also showed decreased perfusion in the contralateral thalamus on brain SPECT. One patients with right hemisensory impairment showed ipsilateral perfusion decrease. Two patients who had follow-up brain perfusion SEPCT after treatment revealed normalization of perfusion in the thalamus. Brain perfusion SPECT might be a useful tool in diagnosing patients with hemisensory impairment

  18. Magnetic resonance perfusion imaging without contrast media

    International Nuclear Information System (INIS)

    Martirosian, Petros; Graf, Hansjoerg; Schick, Fritz; Boss, Andreas; Schraml, Christina; Schwenzer, Nina F.; Claussen, Claus D.

    2010-01-01

    Principles of magnetic resonance imaging techniques providing perfusion-related contrast weighting without administration of contrast media are reported and analysed systematically. Especially common approaches to arterial spin labelling (ASL) perfusion imaging allowing quantitative assessment of specific perfusion rates are described in detail. The potential of ASL for perfusion imaging was tested in several types of tissue. After a systematic comparison of technical aspects of continuous and pulsed ASL techniques the standard kinetic model and tissue properties of influence to quantitative measurements of perfusion are reported. For the applications demonstrated in this paper a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion preparation approach followed by true fast imaging with steady precession (true FISP) data recording was developed and implemented on whole-body scanners operating at 0.2, 1.5 and 3 T for quantitative perfusion measurement in various types of tissue. ASL imaging provides a non-invasive tool for assessment of tissue perfusion rates in vivo. Images recorded from kidney, lung, brain, salivary gland and thyroid gland provide a spatial resolution of a few millimetres and sufficient signal to noise ratio in perfusion maps after 2-5 min of examination time. Newly developed ASL techniques provide especially high image quality and quantitative perfusion maps in tissues with relatively high perfusion rates (as also present in many tumours). Averaging of acquisitions and image subtraction procedures are mandatory, leading to the necessity of synchronization of data recording to breathing in abdominal and thoracic organs. (orig.)

  19. Selecting Safe Pets (For Parents)

    Science.gov (United States)

    ... supplies (pet bowls, pet bed, leash, etc.) as gifts, then selecting the pet as a family. That way, everyone has time to really think about whether your family is ready for a pet. Key Questions Before adopting or purchasing any pet, talk to all family members, discuss ...

  20. Automatic delineation of brain regions on MRI and PET images from the pig.

    Science.gov (United States)

    Villadsen, Jonas; Hansen, Hanne D; Jørgensen, Louise M; Keller, Sune H; Andersen, Flemming L; Petersen, Ida N; Knudsen, Gitte M; Svarer, Claus

    2018-01-15

    The increasing use of the pig as a research model in neuroimaging requires standardized processing tools. For example, extraction of regional dynamic time series from brain PET images requires parcellation procedures that benefit from being automated. Manual inter-modality spatial normalization to a MRI atlas is operator-dependent, time-consuming, and can be inaccurate with lack of cortical radiotracer binding or skull uptake. A parcellated PET template that allows for automatic spatial normalization to PET images of any radiotracer. MRI and [ 11 C]Cimbi-36 PET scans obtained in sixteen pigs made the basis for the atlas. The high resolution MRI scans allowed for creation of an accurately averaged MRI template. By aligning the within-subject PET scans to their MRI counterparts, an averaged PET template was created in the same space. We developed an automatic procedure for spatial normalization of the averaged PET template to new PET images and hereby facilitated transfer of the atlas regional parcellation. Evaluation of the automatic spatial normalization procedure found the median voxel displacement to be 0.22±0.08mm using the MRI template with individual MRI images and 0.92±0.26mm using the PET template with individual [ 11 C]Cimbi-36 PET images. We tested the automatic procedure by assessing eleven PET radiotracers with different kinetics and spatial distributions by using perfusion-weighted images of early PET time frames. We here present an automatic procedure for accurate and reproducible spatial normalization and parcellation of pig PET images of any radiotracer with reasonable blood-brain barrier penetration. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Correlation between arterial spin labeling MRI and dynamic FDG on PET-MR in Alzheimer’s disease and non-Alzhiemer’s disease patients

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, David; Goubran, Maged; Wilson, Eugene; Xu, Guofan; Tripathi, Pragya; Holley, Dawn; Chao, Steven; Wintermark, Max; Quon, Andrew; Zeineh, Michael; Vasanawala, Minal; Zaharchuk, Greg [Stanford University, California (United States)

    2015-05-18

    Regional hypoperfusion on Arterial Spin Labeling (ASL) MRI and corresponding regions of hypometabolism on FDG PET have been reported in Alzheimer’s Disease (AD). To our knowledge these correlations have not been studied under simultaneous acquisition. The purpose of this study is to investigate the correlation of ASL with FDG PET under simultaneous acquisition on PET-MR and to explore this correlation as a possible biomarker for AD. Dynamic FDG and ASL imaging was performed using a simultaneous TOF-enabled PET-MR scanner in 7 subjects without AD and 3 subjects with AD. Average age was 68±5 years. Automated atlas-based segmentation was performed using T2 MRI using the Talairach atlas. Quantitative analysis of ASL and FDG (delayed 45-75 minute scan) was performed in five regions using the pons as a reference region for both perfusion and metabolism. Statistical analyses included Spearman’s correlation and student’s t-test. Significant correlation of relative perfusion and metabolism was found in two of the five brain regions including the putamen (p = 0.018) and the hippocampus (p = 0.031). In addition, there was significant difference between the relative perfusion and metabolism of the thalamus (p = 0.04). No difference was seen between the AD and non-AD groups. Simultaneous PET-MR demonstrates a positive correlation of perfusion of ASL with metabolism on FDG PET in the hippocampus and putamen. The putamen correlation has previously been reported in the literature on a non-simultaneous ASL and FDG imaging. The thalamus was noted to have a difference in the relative perfusion and metabolism representing a perfusion-metabolism mismatch. Future studies should explore the correlation in additional brain regions and the meaning of perfusion-metabolism mismatches as potential imaging biomarkers for patients with and without AD.

  2. Pet-Related Infections.

    Science.gov (United States)

    Day, Michael J

    2016-11-15

    Physicians and veterinarians have many opportunities to partner in promoting the well-being of people and their pets, especially by addressing zoonotic diseases that may be transmitted between a pet and a human family member. Common cutaneous pet-acquired zoonoses are dermatophytosis (ringworm) and sarcoptic mange (scabies), which are both readily treated. Toxoplasmosis can be acquired from exposure to cat feces, but appropriate hygienic measures can minimize the risk to pregnant women. Persons who work with animals are at increased risk of acquiring bartonellosis (e.g., cat-scratch disease); control of cat fleas is essential to minimize the risk of these infections. People and their pets share a range of tick-borne diseases, and exposure risk can be minimized with use of tick repellent, prompt tick removal, and appropriate tick control measures for pets. Pets such as reptiles, amphibians, and backyard poultry pose a risk of transmitting Salmonella species and are becoming more popular. Personal hygiene after interacting with these pets is crucial to prevent Salmonella infections. Leptospirosis is more often acquired from wildlife than infected dogs, but at-risk dogs can be protected with vaccination. The clinical history in the primary care office should routinely include questions about pets and occupational or other exposure to pet animals. Control and prevention of zoonoses are best achieved by enhancing communication between physicians and veterinarians to ensure patients know the risks of and how to prevent zoonoses in themselves, their pets, and other people.

  3. Imaging of the myocardium using {sup 18}F-FDG-PET/MRI

    Energy Technology Data Exchange (ETDEWEB)

    Ferda, Jiří, E-mail: ferda@fnplzen.cz [Clinic of the Imaging Methods, University Hospital Plzen, Alej Svobody 80, 304 60 Plzeň (Czech Republic); Hromádka, Milan, E-mail: hromadkam@fnplzen.cz [Department of Cardiology, University Hospital Plzen, Alej Svobody 80, 304 60 Plzeň (Czech Republic); Baxa, Jan, E-mail: baxaj@fnplzen.cz [Clinic of the Imaging Methods, University Hospital Plzen, Alej Svobody 80, 304 60 Plzeň (Czech Republic)

    2016-10-15

    Highlights: • The natural combination of the metabolic and structural information is the most important strenghtof myocardial PET/MRI. • Metabolic conversion to glycolysis is needed in the assesment ov the viable myocardium. • Metabolic conversion to the fatty acid metabolism is the crucial in the assesment of the ischemic memory and myocardial inflammation. - Abstract: The introduction of the integrated hybrid PET/MRI equipment creates the possibility to perform PET and MRI simultaneously. Depending on the clinical question, the metabolic conversion to glycolytic activity or beta-oxidation is performed before the application of FDG. Since FDG aids to evaluate the energetic metabolism of the myocytes and myocardial MRI reaches the imaging capabilities of perfusion and tissue characterization in the daily routine, FDG-PET/MRI looks to be a promising method of PET/MRI exploitation in cardiac imaging. When myocardial FDG uptake should be evaluated in association with the perfusion distribution, the cross-evaluation of FDG accumulation distribution and perfusion distribution pattern is necessary. The different scenarios may be used in the assessment of myocardium, the conversion to glycolytic activity is used in the imaging of the viable myocardium, but the glycolytic activity suppression might be used in the indications of the identification of injured myocardium by ischemia or inflammation. FDG-PET/MRI might aid to answer the clinical tasks according to the structure, current function and possibilities to improve the function in ischemic heart disease or to display the extent or activity of myocardial inflammation in sarcoidosis. The tight coupling between metabolism, perfusion and contractile function offers an opportunity for the simultaneous assessment of cardiac performance using one imaging modality.

  4. Comparisons of 13NH3, 18FDG PET and MRS in the presurgical evaluation of intractable epilepsy

    International Nuclear Information System (INIS)

    Cai Li; Gao Shuo; Li Dacheng; Li Zugui

    2004-01-01

    Purpose: Surgery offers a high chance of seizure-free outcome in patients with intractable epilepsy. Other than EEG, several functional and morphologic imaging Methods are used to define the spatial seizure origin. Blood flow perfusion and metabolic abnormalities in those patients are well described respectively. Proton MR spectroscopy (MRS) is still in the early stages in the evaluation of epilepsy. Comparisons with 13NH3 perfusion, 18FDG metabolic PET imaging and MRS in the same patients have rarely been documented. The present study was undertaken to compare the merits of 13NH3 PET, 18FDG PET, magnetic resonance imaging (MRI) and MRS for the lateralization of seizure foci. Methods: Preoperative long-term-EEG, Video-EEG, 13NH3 perfusion PET, 18FDG metabolic PET, MRI, MRS and neuropsychological assessment were performed in 15 patients with intractable epilepsy within 2 weeks(mean age=24.8 years, range 4 to 44 years; mean epilepsy duration=11 years, range 2 to 36 years), who received electrocorticography (ECoG). Antiepileptic drug (AED) was stopped taking at least 2 days before PET scanning. 13NH3 and FDG PET was performed in one day and analyzed with a region of interest template. An absolute asymmetry index, |AI|, greater than 0.15 was considered abnormal. 13 subjects were underwent MRS obtained from the hippocampus bilaterally, who had a presumptive temporal seizure focus based on seizure semiology, video-EEG and MRI. Metabolite ratio of NAA/Cho+Cr was calculated from the relative peak height measurements. An NAA/Cho+Cr ratio of 0.72 or less was regarded as abnormal. All the examination Results were compared with EcoG to evaluate their values of seizure foci lateraliaztion. Results: 1. The results were divided into ictal (n=4) and interictal (n= 11) groups. In the ictal group, the sensitivity of 13NH3 PET and 18FDG PET were both 100%(4/4), and 13NH3 PET showed bilateral hippocampus hyperfusion foci in one case. In the interictal group, 13NH3 PET correctly

  5. Assessment of foot perfusion in patients with a diabetic foot ulcer.

    Science.gov (United States)

    Forsythe, Rachael O; Hinchliffe, Robert J

    2016-01-01

    Assessment of foot perfusion is a vital step in the management of patients with diabetic foot ulceration, in order to understand the risk of amputation and likelihood of wound healing. Underlying peripheral artery disease is a common finding in patients with foot ulceration and is associated with poor outcomes. Assessment of foot perfusion should therefore focus on identifying the presence of peripheral artery disease and to subsequently estimate the effect this may have on wound healing. Assessment of perfusion can be difficult because of the often complex, diffuse and distal nature of peripheral artery disease in patients with diabetes, as well as poor collateralisation and heavy vascular calcification. Conventional methods of assessing tissue perfusion in the peripheral circulation may be unreliable in patients with diabetes, and it may therefore be difficult to determine the extent to which poor perfusion contributes to foot ulceration. Anatomical data obtained on cross-sectional imaging is important but must be combined with measurements of tissue perfusion (such as transcutaneous oxygen tension) in order to understand the global and regional perfusion deficit present in a patient with diabetic foot ulceration. Ankle-brachial pressure index is routinely used to screen for peripheral artery disease, but its use in patients with diabetes is limited in the presence of neuropathy and medial arterial calcification. Toe pressure index may be more useful because of the relative sparing of pedal arteries from medial calcification but may not always be possible in patients with ulceration. Fluorescence angiography is a non-invasive technique that can provide rapid quantitative information about regional tissue perfusion; capillaroscopy, iontophoresis and hyperspectral imaging may also be useful in assessing physiological perfusion but are not widely available. There may be a future role for specialized perfusion imaging of these patients, including magnetic resonance

  6. Comparison of Clinical Usefulness between N-13 Ammonia PET/CT and Tc-99m Sestamibi SPECT in Coronary Artery Disease

    International Nuclear Information System (INIS)

    Kong, Eun Jung; Cho, Ihn Ho; Chun, Kyung Ah; Won, Kyu Chang; Lee, Hyung Woo; Park, Jeong Sun; Shin, Dong Gu; Kim, Young Jo; Shim, Bong Seop

    2008-01-01

    N-13 ammonia uptake and retention in the myocardium is related to perfusion and metabolism. There are several potential advantages of N-13 ammonia positron emission tomography (PET) to detect myocardial ischemia, such as higher spatial resolution, greater counting efficiencies, and robust attenuation correction. But there are few reports comparing Tc-99m myocardial perfusion single photon emission tomography (MPS) and N-13 ammonia PET. We thus compared adenosine stress N-13 ammonia PET/CT and Tc-99m sestamibi MPS in patients with suspected coronary artery stenosis. Seventeen patients (male 13 : 63±11 years old) underwent adenosine stress N-13 ammonia PET/CT (Discovery ST, GE), Tc-99m sestamibi MPS (dual head gamma camera, Hawkeye, GE) and coronary angiography within 1 week. N-13 ammonia PET/CT and Tc-99m sestamibi MPS images were assessed with a 20-segment model by visual interpretation and quantitative analysis using automatic quantitative software (Myovation, GE). Both sensitivities and specificities of detecting an individual coronary artery stenosis were higher for N-13 ammonia PET/CT than Tc-99m sestamibi MPS (PET/CT: 91%/ 89% vs MPS: 65%/ 82%). N-13 ammonia PET/CT showed reversibility in 52% of segments that were considered non-reversible by Tc-99m sestamibi MPS. In the 110 myocardial segments supplied by the stenotic coronary artery, N-13 ammonia PET/CT showed higher count densities than Tc-99m MPS on rest study (p < 0.01), and the difference of count density between the stress and the rest studies was also larger on N-13 ammonia PET/CT. Adenosine stress N-13 ammonia PET/CT had higher diagnostic sensitivity and specificity, more reversibility of perfusion defects and greater stress/rest uptake differences than Tc-99m sestamibi MPS. Accordingly, N-13 ammonia PET/CT might offer better assessment of myocardial ischemia and viability

  7. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

    Immink, R V; Pott, F C; Secher, N H

    2014-01-01

    dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2...... the contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced...... cardiac output brain perfusion becomes jeopardized. Whether, in patients with cardiovascular disease and/or defect, cerebral blood flow cerebral control HV-induced hypocapnia elicits cerebral hypoperfusion, leading to TLOC, remains to be established....

  8. Myocardial perfusion modeling using MRI

    DEFF Research Database (Denmark)

    Larsson, H B; Fritz-Hansen, T; Rostrup, Egill

    1996-01-01

    In the present study, it is shown that it is possible to quantify myocardial perfusion using magnetic resonance imaging in combination with gadolinium diethylenetriaminopentaacetic acid (Gd-DTPA). Previously, a simple model and method for measuring myocardial perfusion using an inversion recovery...... turbo-FLASH (fast low-angle shot) sequence and Gd-DTPA has been presented. Here, an extension of the model is presented taking into account fast and slow water exchange between the compartments, enabling the calculation of the unidirectional influx constant (Ki) for Gd-DTPA, the distribution volume...... of Gd-DTPA (lambda), the vascular blood volume (Vb), and the time delay through the coronary arteries (delta T). The model was evaluated by computer simulation and used on experimental results from seven healthy subjects. The results in the healthy volunteers for a region of interest placed...

  9. Perfusion study in the pulmonary hilar region by SPECT

    International Nuclear Information System (INIS)

    Satoh, Katashi; Tanabe, Masatada; Kawase, Yoshiro

    1990-01-01

    Alveoli in the hilar region comprise the peripheral area containing daughter branches from subsegmental or one more divisional peripheral bronchi. Pulmonary perfusion in hilar region was examined by SPECT (single photon emission CT) in ten normal volunteers. ROI (region of interest) in the axial images were set in the hilar region, the upper, middle and lower lung fields with 10.8 mm thickness. Counts/one pixel (C/P) were calculated in these ROI. There was a tendency of C/P increase from upper to lower lung field. And there were no significant differences in C/P increase between hilar region and other axial fields. In the chronic obstructive pulmonary diseases, however, ventilation studies in the previous reports using Xe dynamic CT or PET (positron emission tomography) showed differences between outer region and hilar region. This method will be expected to evaluate the pulmonary perfusion not only in the whole lung but in different lung areas, including the hilar region in the chronic obstructive pulmonary diseases. (author)

  10. Pets and the immunocompromised person

    Science.gov (United States)

    ... marrow transplant patients and pets; Chemotherapy patients and pets ... Centers for Disease Control and Prevention website. Healthy pets healthy people. www.cdc.gov/healthypets . Updated July 19, 2016. ...

  11. Sensory analysis of pet foods.

    Science.gov (United States)

    Koppel, Kadri

    2014-08-01

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

  12. Les Particules élémentaires: Self–portrait

    Directory of Open Access Journals (Sweden)

    Gerald Prince

    2012-01-01

    Full Text Available Perhaps no French novel in the past fifteen years has received more critical attention than Michel Houellebecq’s Les Particules élémentaires and perhaps none has evoked stronger reactions with regard to the (literary values it espouses and represents. This (self-portrait, like any portrait, accents certain features more than others. It concentrates on refuting charges of nihilism, reactionaryism, sexism, and racism; it stresses Houellebecq’s novel’s attention to form and its thematic clarity as well as its determination to say something rather than nothing; and, through a consideration of its references to various media, arts, and texts, of its pet peeves and true delights, it specifies the nature and ambition of Les Particules élémentaires , the kind of text it is or aspires to be.

  13. Assessment of PET & ASL metabolism in the hippocampal subfields of MCI and AD using simultaneous PET-MR

    Energy Technology Data Exchange (ETDEWEB)

    Goubran, Maged; Douglas, David; Chao, Steven; Quon, Andrew; Tripathi, Pragya; Holley, Dawn; Vasanawala, Minal; Zaharchuk, Greg; Zeineh, Michael [Stanford University (United States)

    2015-05-18

    Alzheimer’s disease (AD) has been reported to show decreased metabolic activity in the hippocampus using FDG PET-MR. Histological data suggests that the hippocampal subfields are selectively affected in AD. Given the simultaneous imaging nature of integrated PET-MR scanners and the multimodal capabilities of PET-MR, our purpose here is to assess FDG activity, as well as ASL perfusion in the subfields of MCI and AD patients. 10 consecutive subjects were recruited for this study 3 MCI, 3 AD patients and 4 age-matched controls. The scanning was performed on a simultaneous 3T PET/MR scanner. To delineate the hippocampal subfields, automatic segmentation of hippocampal subfields (ASHS) was employed. Static FDG-PET series were reconstructed for analysis at 45-75 min for all subjects. All imaging sequences were automatically registered to the oblique coronal T2-weighted images (segmentation space). PET standardized uptake values (SUV) in the hippocampal subfields were normalized by the pons. FDG PET metabolism was reduced significantly in AD, as well as MCI patients as compared to controls, with the highest effect demonstrated in the CA3/DG and CA1/2 (p = 0.047, subfields. Patients (MCI and AD combined) had decreased metabolism as compared to controls in CA1/2 and significantly smaller volumes the Subiculum. When assessing CBF across groups, a significant decrease in CBF was found in the Subiculum. Our preliminary results demonstrate that PET-MRI may potentially be a sensitive biomarker and tool for early diagnosis of AD. They also confirm the importance of assessing metabolic and structural changes of neurodegenerative diseases at the subfield level.

  14. Dosimetry in myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C. [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2011-07-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  15. Dosimetry in myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C.

    2011-01-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  16. Perfusion abnormalities in congenital and neoplastic pulmonary disease: comparison of MR perfusion and multislice CT imaging

    International Nuclear Information System (INIS)

    Boll, Daniel T.; Lewin, Jonathan S.; Young, Philip; Gilkeson, Robert C.; Siwik, Ernest S.

    2005-01-01

    The aim of this work was to assess magnetic resonance (MR) perfusion patterns of chronic, nonembolic pulmonary diseases of congenital and neoplastic origin and to compare the findings with results obtained with pulmonary, contrast-enhanced multislice computed tomography (CT) imaging to prove that congenital and neoplastic pulmonary conditions require MR imaging over the pulmonary perfusion cycle to successfully and directly detect changes in lung perfusion patterns. Twenty-five patients underwent concurrent CT and MR evaluation of chronic pulmonary diseases of congenital (n=15) or neoplastic (n=10) origin. Analysis of MR perfusion and contrast-enhanced CT datasets was realized by defining pulmonary and vascular regions of interest in corresponding positions. MR perfusion calculated time-to-peak enhancement, maximal enhancement and the area under the perfusion curve. CT datasets provided pulmonary signal-to-noise ratio measurements. Vessel centerlines of bronchial arteries were determined. Underlying perfusion type, such as pulmonary arterial or systemic arterial supply, as well as regions with significant variations in perfusion were determined statistically. Analysis of the pulmonary perfusion pattern detected pulmonary arterial supply in 19 patients; six patients showed systemic arterial supply. In pulmonary arterial perfusion, MR and multislice CT imaging consistently detected the perfusion type and regions with altered perfusion patterns. In bronchial arterial supply, MR perfusion and CT imaging showed significant perfusion differences. Patients with bronchial arterial supply had bronchial arteries ranging from 2.0 to 3.6 mm compared with submillimeter diameters in pulmonary arterial perfusion. Dynamic MR imaging of congenital and neoplastic pulmonary conditions allowed characterization of the pulmonary perfusion type. CT imaging suggested the presence of systemic arterial perfusion by visualizing hypertrophied bronchial arteries. (orig.)

  17. Clinical PET application

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Moo; Hong, Song W.; Choi, Chang W.; Yang, Seong Dae [Korea Cancer Center Hospital, Seoul (Korea)

    1997-12-01

    PET gives various methabolic images, and is very important, new diagnostic modality in clinical oncology. In Korea Cancer Center Hospital, PET is installed as a research tool of long-mid-term atomic research project. For the efficient use of PET for clinical and research projects, income from the patients should be managed to get the raw material, equipment, manpower, and also for the clinical PET research. 1. Support the clinical application of PET in oncology. 2. Budgetary management of income, costs for raw material, equipment, manpower, and the clinical PET research project. In this year, 250 cases of PET images were obtained, which resulted total income of 180,000,000 won. 50,000,000 won was deposited for the 1998 PET clinical research. Second year PET clinical research should be managed under unified project. Increased demand for {sup 18}FDG in and outside KCCH need more than 2 times production of {sup 18}FDG in a day purchase of HPLC pump and {sup 68}Ga pin source which was delayed due to economic crisis, should be done early in 1998. (author). 2 figs., 3 tabs.

  18. Imaging with PET system

    International Nuclear Information System (INIS)

    Das, B.K.; Noreen Norfaraheen Lee Abdullah

    2012-01-01

    PET deals with biochemistry and metabolic changes that occur at molecular level. Hence, PET differs fundamentally from other imaging modalities. CT imaging is based on tissue density, whereas MRI conveys anatomic information based on proton density and proton relaxation dynamics. CT and MRI are useful in clinical diagnosis only when disease process has caused significant anatomic alterations. However, in most disease conditions chemical changes precede anatomic changes, that can be detected by PET technology. Thus, PET can provide earliest and unique information about ongoing disease process long before anatomic or structural changes take place. There is no other modality available at present that can replace PET technology. Although PET produces cross-sectional images like that obtained in MRI or CT, they represent circulation, function and metabolism, and not anatomic structure. PET is extremely sensitive measuring quantitatively concentration of tracers in nano to pico-molar range. Thus, PET enables merger of biochemistry and biology in medicine giving birth to molecular medicine that focuses on identifying the molecular errors of disease leading to developing molecular corrections including gene therapy. Molecular imaging with PET has been playing a role in examining the biological nature of a disease condition and its characterization to guide selection and evaluation of treatment. (author)

  19. Studies on glucose metabolism and blood perfusion in childhood partial seizure by positron emission CT

    International Nuclear Information System (INIS)

    Michihiro, Narumi

    1986-01-01

    To investigate the glucose metabolism and blood perfusion of the interictal epileptic focus, 15 positron emission tomography (PET) measurements were performed in 14 children with partial seizures (2 with simple partial seizures, 2 with complex partial seizures, and 10 with partial seizures evolving to secondary generalized seizures), comprising 7 males and 7 females aged 1 to 12 years old at the onset of the epileptic seizures. The intervals between the seizure onset and PET examinations were 1 month to 7 years (mean 3 1/4 years). Radiopharmaceuticals such as 11 C-glucose, 11 CO 2 and 11 CO were used as indicators of local cerebral glucose metabolism, blood perfusion and blood flow, respectively. Apart from 2 cases, none of the patients showed abnormal x-ray computed tomographic scans (X-CT). The abnormal X-CT findings included cortical atrophy of the cerebrum apart from the epiletic focus in one case and cavum vergae in the other. Hypometabolism and hypoperfusion at the epileptic focus were observed in 10 patients undergoing single examinations who had suffered from epileptic seizures for more than 1 year. Out of 4 patients who had suffered from epileptic seizures for 1 year or less, one revealed a zone of hypometabolism and hypoperfusion in the epileptic focus and expanded region larger than that of the epileptic focus on the electroencephalogram. Two other patients revealed a zone of hypometabolism and hypoperfusion in an area contralateral to the epileptic focus. In the remaining one patient, PET examinations were performed twice. The initial PET pictures one year after seizure onset revealed a zone of hypermetabolism and hyperperfusion in the cerebellum ipsilateral to the epileptic focus, and the second PET at 6 months after the initial examination revealed hypometabolism and hypoperfusion in the focus, similarly to the 10 cases mentioned above. (J.P.N.)

  20. Airborne Particulate Threat Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  1. Resting functional imaging tools (MRS, SPECT, PET and PCT).

    Science.gov (United States)

    Van Der Naalt, J

    2015-01-01

    Functional imaging includes imaging techniques that provide information about the metabolic and hemodynamic status of the brain. Most commonly applied functional imaging techniques in patients with traumatic brain injury (TBI) include magnetic resonance spectroscopy (MRS), single photon emission computed tomography (SPECT), positron emission tomography (PET) and perfusion CT (PCT). These imaging modalities are used to determine the extent of injury, to provide information for the prediction of outcome, and to assess evidence of cerebral ischemia. In TBI, secondary brain damage mainly comprises ischemia and is present in more than 80% of fatal cases with traumatic brain injury (Graham et al., 1989; Bouma et al., 1991; Coles et al., 2004). In particular, while SPECT measures cerebral perfusion and MRS determines metabolism, PET is able to assess both perfusion and cerebral metabolism. This chapter will describe the application of these techniques in traumatic brain injury separately for the major groups of severity comprising the mild and moderate to severe group. The application in TBI and potential difficulties of each technique is described. The use of imaging techniques in children will be separately outlined. © 2015 Elsevier B.V. All rights reserved.

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

    OpenAIRE

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

    2018-01-01

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

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

    OpenAIRE

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

    2018-01-01

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

  4. Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD

    DEFF Research Database (Denmark)

    Buggeskov, Katrine B; Sundskard, Martin M; Jonassen, Thomas

    2016-01-01

    INTRODUCTION: Absence of pulmonary perfusion during cardiopulmonary bypass (CPB) may be associated with reduced postoperative oxygenation. Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease (COPD) undergoing cardiac surgery. METHODS: 90...... perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing cardiac surgery. Pulmonary artery perfusion with hypothermic HTK solution does not seem to improve postoperative oxygenation. TRIAL REGISTRATION NUMBER...

  5. Normal anatomy of lung perfusion SPECT scintigraphy

    International Nuclear Information System (INIS)

    Moskowitz, G.W.; Levy, L.M.

    1987-01-01

    Ten patients studies for possible pulmonary embolic disease had normal lung perfusion planar and SPECT scintigraphy. A computer program was developed to superimpose the CT scans on corresponding SPECT images. Superimposition of CT scans on corresponding SPECT transaxial cross-sectional images, when available, provides the needed definition and relationships of adjacent organs. SPECT transaxial sections provide clear anatomic definition of perfusion defects without foreground and background lung tissue superimposed. The location, shape, and size of the perfusion defects can be readily assessed by SPECT. An algorithm was developed for the differentiation of abnormal pulmonary perfusion patterns from normal structures on variation

  6. Value of dynamic susceptibility contrast perfusion MRI in the acute phase of transient global amnesia.

    Directory of Open Access Journals (Sweden)

    Alex Förster

    Full Text Available Transient global amnesia (TGA is a transitory, short-lasting neurological disorder characterized by a sudden onset of antero- and retrograde amnesia. Perfusion abnormalities in TGA have been evaluated mainly by use of positron emission tomography (PET or single-photon emission computed tomography (SPECT. In the present study we explore the value of dynamic susceptibility contrast perfusion-weighted MRI (PWI in TGA in the acute phase.From a MRI report database we identified TGA patients who underwent MRI including PWI in the acute phase and compared these to control subjects. Quantitative perfusion maps (cerebral blood flow (CBF and volume (CBV were generated and analyzed by use of Signal Processing In NMR-Software (SPIN. CBF and CBV values in subcortical brain regions were assessed by use of VOI created in FIRST, a model-based segmentation tool in the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB Software Library (FSL.Five TGA patients were included (2 men, 3 women. On PWI, no relevant perfusion alterations were found by visual inspection in TGA patients. Group comparisons for possible differences between TGA patients and control subjects showed significant lower rCBF values bilaterally in the hippocampus, in the left thalamus and globus pallidus as well as bilaterally in the putamen and the left caudate nucleus. Correspondingly, significant lower rCBV values were observed bilaterally in the hippocampus and the putamen as well as in the left caudate nucleus. Group comparisons for possible side differences in rCBF and rCBV values in TGA patients revealed a significant lower rCBV value in the left caudate nucleus.Mere visual inspection of PWI is not sufficient for the assessment of perfusion changes in TGA in the acute phase. Group comparisons with healthy control subjects might be useful to detect subtle perfusion changes on PWI in TGA patients. However, this should be confirmed in larger data sets and serial PWI

  7. Birds Kept as Pets

    Science.gov (United States)

    ... your pet’s health Visit a veterinarian who has experience with pet birds for routine check-ups to keep your bird healthy and prevent infectious diseases. If your bird becomes sick or dies within a month after purchase or adoption: Contact your veterinarian. Inform the pet ...

  8. Model PET Scan Activity

    Science.gov (United States)

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

    2018-05-01

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

  9. Clinical Application of {sup 18}F-FDG PET in Epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Kyeong [Seoul National University College of Medicine, Seoul National University Bundang Hospital, Sungnam (Korea, Republic of)

    2008-12-15

    FDG PET has been used as a diagnostic tool for localization of seizure focus for last 2-3 decades. In this article, the clinical usefulness of FDG PET in the management of patients with epilepsy has been reviewed, which provided the evidences to justify the medicare reimbursement for FDG PET in management of patients with epilepsy. Literature review demonstrated that FDG PET provides an important information in localization of seizure focus and determination whether a patients is a surgical candidate or not. FDG PET has been reported to have high diagnostic performance in localization of seizure focus in neocortical epilepsy as well as temporal lobe epilepsy regardless of the presence of structural lesion on MRI. Particularly, FDG PET can provide the additional information when the results from standard diagnositic modality such as interictal or video-monitored EEG, and MRI are inconclusive or discordant, and make to avoid invasive study. Furthermore, the presence of hypometabolism and extent of metabolic extent has been reported as an important predictor for seizure free outcome. However, studies suggested that more accurate localization and better surgical outcome could be expected with multimodal approach by combination of EEG, MRI, and functional studies using FDG PET or perfusion SPECT rather than using a single diagnostic modality in management of patients with epilepsy. Complementary use of FDG PET in management of epilepsy is worth for good surgical outcome in epilepsy patients.

  10. Usage of Recycled Pet

    Directory of Open Access Journals (Sweden)

    A. Ebru Tayyar

    2010-01-01

    Full Text Available The increasing industrialization, urbanization and the technological development have caused to increase depletion of the natural resources and environmental pollution's problem. Especially, for the countries which have not enough space recycling of the waste eliminating waste on regular basis or decreasing the amount and volume of waste have provided the important advantages. There are lots of studies and projects to develop both protect resources and prevent environmental pollution. PET bottles are commonly used in beverage industry and can be reused after physical and chemical recycling processes. Usage areas of recycled PET have been developed rapidly. Although recycled PET is used in plastic industry, composite industry also provides usage alternatives of recycled PET. Textile is a suitable sector for recycling of some plastics made of polymers too. In this study, the recycling technologies and applications of waste PET bottles have been investigated and scientific works in this area have been summarized.

  11. Oncology PET imaging

    International Nuclear Information System (INIS)

    Inubushi, Masayuki

    2014-01-01

    At the beginning of this article, likening medical images to 'Where is Waldo?' I indicate the concept of diagnostic process of PET/CT imaging, so that medical physics specialists could understand the role of each imaging modality and infer our distress for image diagnosis. Then, I state the present situation of PET imaging and the basics (e.g. health insurance coverage, clinical significance, principle, protocol, and pitfall) of oncology FDG-PET imaging which accounts for more than 99% of all clinical PET examinations in Japan. Finally, I would like to give a wishful prospect of oncology PET that will expand to be more cancer-specific in order to assess therapeutic effects of emerging molecular targeted drugs targeting the 'hallmarks of cancer'. (author)

  12. PET and SPECT investigations in Alzheimer's disease

    International Nuclear Information System (INIS)

    Asenbaum, S.

    2003-01-01

    Nuclear medicine offers a wide range of possibilities to investigate dementia. Various SPECT and PET tracers will be introduced in this article first. Different questions concerning evaluation of dementia are discussed taking Alzheimer's disease (AD) as an example. It is important to perform nuclear medicine investigations on high technical level, using standardized methods as statistical parametric mapping (SPM) for evaluation. If neuroprotective therapies are available, an early diagnosis, the determination of risk factors and longitudinal investigations will be the focus of interest and the main goal of nuclear medicine. Apart from measuring cerebral perfusion and glucose metabolism the development of new ligands, concerning the cholinergic system and the visualization of amyloid plaques, is of great importance. (orig.) [de

  13. Comparison of dual-biomarker PIB-PET and dual-tracer PET in AD diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Liping; Zhang, Jinming; Xu, Baixuan; Tian, Jiahe [General Hospital of the Chinese People' s Liberation Army, Department of Nuclear Medicine, Beijing (China); Liu, Linwen; Fan, Yong [Institute of Automation, Chinese Academy of Sciences, National Laboratory of Pattern Recognition, Beijing (China)

    2014-11-15

    To identify the optimal time window for capturing perfusion information from early {sup 11}C-PIB imaging frames (perfusion PIB, {sup 11}C-pPIB) and to compare the performance of {sup 18}F-FDG PET and ''dual biomarker'' {sup 11}C-PIB PET [{sup 11}C-pPIB and amyloid PIB ({sup 11}C-aPIB)] for classification of AD, MCI and CN subjects. Forty subjects (14 CN, 12 MCI and 14 AD patients) underwent {sup 18}F-FDG and {sup 11}C-PIB PET studies. Pearson correlation between the {sup 18}F-FDG image and sum of early {sup 11}C-PIB frames was maximised to identify the optimal time window for {sup 11}C-pPIB. The classification power of imaging parameters was evaluated with a leave-one-out validation. A 7-min time window yielded the highest correlation between {sup 18}F-FDG and {sup 11}C-pPIB. {sup 11}C-pPIB and {sup 18}F-FDG images shared a similar radioactive distribution pattern. {sup 18}F-FDG performed better than {sup 11}C-pPIB for the classification of both AD vs. CN and MCI vs. CN. {sup 11}C-pPIB + {sup 11}C-aPIB and {sup 18}F-FDG + {sup 11}C-aPIB yielded the highest classification accuracy for the classification of AD vs. CN, and {sup 18}F-FDG + {sup 11}C-aPIB had the best classification performance for the classification of MCI vs. CN. C-pPIB could serve as a useful biomarker of rCBF for measuring neural activity and improve the diagnostic power of PET for AD in conjunction with {sup 11}C-aPIB. {sup 18}F-FDG and {sup 11}C-PIB dual-tracer PET examination could better detect MCI. (orig.)

  14. Demonstration of cerebral abnormalities in cocaine abusers with SPECT perfusion brain scans

    International Nuclear Information System (INIS)

    Nagel, J.S.; Tumeh, S.S.; English, R.J.; Moore, M.; Lee, V.W.; Holman, L.B.

    1989-01-01

    This paper reports I-123 isopropyl iodoamphetamine (IMP) single-photon emission CT (SPECT) brain scans performed on cocaine users to investigate the effects of cocaine on the cerebral perfusion in a manner similar to previous CT, angiographic and positron-emission tomographic (PET) studies. Ten asymptomatic or mildly symptomatic cocaine users, two users with major neurovascular complications, and five normal subjects were studied with IMP SPECT. Rotating-brain images of the cerebral IMP uptake were displayed by using a distance-weighted surface-projection technique and were visually analyzed for focal cortical perfusion deficits. Eleven cocaine users had multiple scattered cortical IMP defects. Frontal lobe defects were most prominent. One user had confluent defects resembling swiss cheese. Concurrent CT scans available in nine patients were negative in seven and showed infarcts in two. No similar focal findings were visible in normals

  15. Simultaneous PET/MRI: Impact on cancer management-A comprehensive review of cases

    Directory of Open Access Journals (Sweden)

    Amarnath Jena

    2014-01-01

    Full Text Available The metabolic mapping of malignancy in whole body in a single examination by PET/CT has gained widespread acceptance where the CT provides an anatomical correlate for the PET. MRI offers advantage over CT in providing better anatomical information owing to its high soft tissue resolution especially in brain, liver, neck, pelvis and bone marrow. Simultaneous PET/MRI is a new multimodal imaging modality that is expected to improve the diagnostic performance of imaging wherein better anatomical and metabolic information can be acquired at the same time and space during a single examination time. Also, MR attributes like diffusion, perfusion and spectroscopy may further add to its diagnostic potential. In this article, we present our initial experience in illustrated cases done with simultaneous PET/MRI and outline its potential for several clinical applications in oncology.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-02-15

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  18. Bayesian Penalized Likelihood Image Reconstruction (Q.Clear) in 82Rb Cardiac PET: Impact of Count Statistics

    DEFF Research Database (Denmark)

    Christensen, Nana Louise; Tolbod, Lars Poulsen

    PET scans. 3) Static and dynamic images from a set of 7 patients (BSA: 1.6-2.2 m2) referred for 82Rb cardiac PET was analyzed using a range of beta factors. Results were compared to the institution’s standard clinical practice reconstruction protocol. All scans were performed on GE DMI Digital......Aim: Q.Clear reconstruction is expected to improve detection of perfusion defects in cardiac PET due to the high degree of image convergence and effective noise suppression. However, 82Rb (T½=76s) possess a special problem, since count statistics vary significantly not only between patients...... statistics using a cardiac PET phantom as well as a selection of clinical patients referred for 82Rb cardiac PET. Methods: The study consistent of 3 parts: 1) A thorax-cardiac phantom was scanned for 10 minutes after injection of 1110 MBq 82Rb. Frames at 3 different times after infusion were reconstructed...

  19. Quality assessment of a placental perfusion protocol

    DEFF Research Database (Denmark)

    Mathiesen, Line; Mose, Tina; Mørck, Thit Juul

    2010-01-01

    mlh(-1) from the fetal reservoir) when adding 2 (n=7) and 20mg (n=9) FITC-dextran/100ml fetal perfusion media. Success rate of the Copenhagen placental perfusions is provided in this study, including considerations and quality control parameters. Three checkpoints suggested to determine success rate...

  20. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Yong; Lee, Ki Hyeong; Yoon, Byung Woo; Lee, Sang Bok; Jeon, Beom S. [Samsung Medical Center, Seoul (Korea, Republic of); Lee, Kyung Han; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1996-03-15

    Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p<0.05). There was no correlation between the severity of the motor abnormality and any of the regional cerebral perfusion indices (p>0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

  1. Computed Tomography (CT) Perfusion in Abdominal Cancer

    DEFF Research Database (Denmark)

    Hansen, Martin Lundsgaard; Norling, Rikke; Lauridsen, Carsten

    2013-01-01

    Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed...

  2. Clinical application of cerebral dynamic perfusion studies

    International Nuclear Information System (INIS)

    DeLand, F.H.

    1975-01-01

    Radionuclide cerebral perfusion studies are assuming a far greater importance in the detection and differential diagnosis of cerebral lesions. Perfusion studies not only contribute to the differential diagnosis of lesions but in certain cases are the preferred methods by which more accurate clinical interpretations can be made. The characteristic blood flow of arterio-venous malformations readily differentiates this lesion from neoplasms. The decreased perfusion or absent perfusion observed in cerebral infarctions is diagnostic without concurrent evidence from static images. Changes in rates and direction of blood flow contribute fundamental information to the status of stenosis and vascular occlusion and, in addition, offer valuable information on the competency and routes of collateral circulation. The degree of cerebral perfusion after cerebral vascular accidents appears to be directly related to patient recovery, particularly muscular function. Cerebral perfusion adds a new parameter in the diagnosis of subdural haematomas and concussion and in the differentiation of obscuring radioactivity from superficial trauma. Although pictorial displays of perfusion blood flow will offer information in most cerebral vascular problems, the addition of computer analysis better defines temporal relationships of regional blood flow, quantitative changes in flow and the detection of the more subtle increases or decreases in cerebral blood flow. The status of radionuclide cerebral perfusion studies has taken on an importance making it the primary modality for the diagnosis of cerebral lesions. (author)

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

    Science.gov (United States)

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

    2018-02-01

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

  4. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

  5. Kinetic analysis of dynamic 18F-fluoromisonidazole PET correlates with radiation treatment outcome in head-and-neck cancer

    Directory of Open Access Journals (Sweden)

    Paulsen Frank

    2005-12-01

    Full Text Available Abstract Background Hypoxia compromises local control in patients with head-and-neck cancer (HNC. In order to determine the value of [18F]-fluoromisonidazole (Fmiso with regard to tumor hypoxia, a patient study with dynamic Fmiso PET was performed. For a better understanding of tracer uptake and distribution, a kinetic model was developed to analyze dynamic Fmiso PET data. Methods For 15 HNC patients, dynamic Fmiso PET examinations were performed prior to radiotherapy (RT treatment. The data was analyzed using a two compartment model, which allows the determination of characteristic hypoxia and perfusion values. For different parameters, such as patient age, tumor size and standardized uptake value, the correlation to treatment outcome was tested using the Wilcoxon-Mann-Whitney U-test. Statistical tests were also performed for hypoxia and perfusion parameters determined by the kinetic model and for two different metrics based on these parameters. Results The kinetic Fmiso analysis extracts local hypoxia and perfusion characteristics of a tumor tissue. These parameters are independent quantities. In this study, different types of characteristic hypoxia-perfusion patterns in tumors could be identified. The clinical verification of the results, obtained on the basis of the kinetic analysis, showed a high correlation of hypoxia-perfusion patterns and RT treatment outcome (p = 0.001 for this initial patient group. Conclusion The presented study established, that Fmiso PET scans may benefit from dynamic acquisition and analysis by a kinetic model. The pattern of distribution of perfusion and hypoxia in the tissue is correlated to local control in HNC.

  6. Regional association of pCASL-MRI with FDG-PET and PiB-PET in people at risk for autosomal dominant Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Lirong Yan

    2018-01-01

    Full Text Available Autosomal dominant Alzheimer's disease (ADAD is a small subset of Alzheimer's disease that is genetically determined with 100% penetrance. It provides a valuable window into studying the course of pathologic processes that leads to dementia. Arterial spin labeling (ASL MRI is a potential AD imaging marker that non-invasively measures cerebral perfusion. In this study, we investigated the relationship of cerebral blood flow measured by pseudo-continuous ASL (pCASL MRI with measures of cerebral metabolism (FDG PET and amyloid deposition (Pittsburgh Compound B (PiB PET. Thirty-one participants at risk for ADAD (age 39±13 years, 19 females were recruited into this study, and 21 of them received both MRI and FDG and PiB PET scans. Considerable variability was observed in regional correlations between ASL-CBF and FDG across subjects. Both regional hypo-perfusion and hypo-metabolism were associated with amyloid deposition. Cross-sectional analyses of each biomarker as a function of the estimated years to expected dementia diagnosis indicated an inverse relationship of both perfusion and glucose metabolism with amyloid deposition during AD development. These findings indicate that neurovascular dysfunction is associated with amyloid pathology, and also indicate that ASL CBF may serve as a sensitive early biomarker for AD. The direct comparison among the three biomarkers provides complementary information for understanding the pathophysiological process of AD.

  7. Brain Perfusion Changes in Intracerebral Hemorrhage

    International Nuclear Information System (INIS)

    Mititelu, R.; Mazilu, C.; Ghita, S.; Rimbu, A.; Marinescu, G.; Codorean, I.; Bajenaru, O.

    2006-01-01

    Full text: Purpose: Despite the latest advances in medical treatment and neuro critical care, patients suffering spontaneous intracerebral hemorrhage (SICH) still have a very poor prognosis, with a greater mortality and larger neurological deficits at the survivors than for ischemic stroke. Many authors have shown that there are many mechanisms involved in the pathology of SICH: edema, ischemia, inflammation, apoptosis. All of these factors are affecting brain tissue surrounding hematoma and are responsible of the progressive neurological deterioration; most of these damages are not revealed by anatomical imaging techniques. The aim of our study was to asses the role of brain perfusion SPECT in demonstrating perfusion changes in SICH patients. Method: 17 SICH pts were studied. All pts underwent same day CT and brain SPECT with 99mTcHMPAO, 24h-5d from onset of stroke. Results: 14/17 pts showed a larger perfusion defect than expected after CT. In 2 pts hematoma diameter was comparable on CT and SPECT; 1pt had quasinormal aspect of SPECT study. In pts with larger defects, SPECT revealed a large cold spot with similar size compared with CT, and a surrounding hypo perfused area. 6/17 pts revealed cortical hyper perfusion adjacent to hypo perfused area and corresponding to a normal-appearing brain tissue on CT. In 3 pts we found crossed cerebellar diaskisis.In 2 pts we found cortical hypo perfused area in the contralateral cortex, with normal appearing brain tissue on CT. Conclusions: Brain perfusion SPECT revealed different types of perfusion changes in the brain tissue surrounding hematoma. These areas contain viable brain tissue that may be a target for future ne uroprotective strategies. Further studies are definitely required to demonstrate prognostic significance of these changes, but we can conclude that brain perfusion SPECT can play an important role in SICH, by early demonstrating functional changes responsible of clinical deterioration, thus allowing prompt

  8. Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Rollo, F.D.; Hines, H.

    2001-01-01

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

  9. ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Ye Zhuang; Stanley J. Miller; Michelle R. Olderbak; Rich Gebert

    2001-12-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hr parametric tests and 100-hr proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency. Since all of the developmental goals of Phase I were met, the approach was scaled up in Phase II to a size of 255 m{sup 3}/min (9000 acfm) (equivalent in size to 2.5 MW) and was installed on a slipstream at the Big Stone Power Plant. For Phase II, the AHPC at Big Stone Power Plant was operated continuously from late July 1999 until mid-December 1999. The Phase II results were highly successful in that ultrahigh particle collection efficiency was achieved, pressure drop was well controlled, and system operability was excellent. For Phase III, the AHPC was modified into a more compact configuration, and components were installed that were closer to what would be used in a full-scale commercial design. The modified AHPC was operated from April to July 2000. While operational results were acceptable during this time, inspection of bags in the summer of 2000 revealed some membrane damage to the fabric that appeared to be

  10. PET studies in epilepsy

    Science.gov (United States)

    Sarikaya, Ismet

    2015-01-01

    Various PET studies, such as measurements of glucose, serotonin and oxygen metabolism, cerebral blood flow and receptor bindings are availabe for epilepsy. 18Fluoro-2-deoxyglucose (18F-FDG) PET imaging of brain glucose metabolism is a well established and widely available technique. Studies have demonstrated that the sensitivity of interictal FDG-PET is higher than interictal SPECT and similar to ictal SPECT for the lateralization and localization of epileptogenic foci in presurgical patients refractory to medical treatments who have noncontributory EEG and MRI. In addition to localizing epileptogenic focus, FDG-PET provide additional important information on the functional status of the rest of the brain. The main limitation of interictal FDG-PET is that it cannot precisely define the surgical margin as the area of hypometabolism usually extends beyond the epileptogenic zone. Various neurotransmitters (GABA, glutamate, opiates, serotonin, dopamine, acethylcholine, and adenosine) and receptor subtypes are involved in epilepsy. PET receptor imaging studies performed in limited centers help to understand the role of neurotransmitters in epileptogenesis, identify epileptic foci and investigate new treatment approaches. PET receptor imaging studies have demonstrated reduced 11C-flumazenil (GABAA-cBDZ) and 18F-MPPF (5-HT1A serotonin) and increased 11C-cerfentanil (mu opiate) and 11C-MeNTI (delta opiate) bindings in the area of seizure. 11C-flumazenil has been reported to be more sensitive than FDG-PET for identifying epileptic foci. The area of abnormality on GABAAcBDZ and opiate receptor images is usually smaller and more circumscribed than the area of hypometabolism on FDG images. Studies have demonstrated that 11C-alpha-methyl-L-tryptophan PET (to study synthesis of serotonin) can detect the epileptic focus within malformations of cortical development and helps in differentiating epileptogenic from non-epileptogenic tubers in patients with tuberous sclerosis complex

  11. Potential Applications of PET/MR Imaging in Cardiology.

    Science.gov (United States)

    Ratib, Osman; Nkoulou, René

    2014-06-01

    Recent advances in hybrid PET/MR imaging have opened new perspectives for cardiovascular applications. Although cardiac MR imaging has gained wider adoption for routine clinical applications, PET images remain the reference in many applications for which objective analysis of metabolic and physiologic parameters is needed. In particular, in cardiovascular diseases-more specifically, coronary artery disease-the use of quantitative and measurable parameters in a reproducible way is essential for the management of therapeutic decisions and patient follow-up. Functional MR images and dynamic assessment of myocardial perfusion from transit of intravascular contrast medium can provide useful criteria for identifying areas of decreased myocardial perfusion or for assessing tissue viability from late contrast enhancement of scar tissue. PET images, however, will provide more quantitative data on true tissue perfusion and metabolism. Quantitative myocardial flow can also lead to accurate assessment of coronary flow reserve. The combination of both modalities will therefore provide complementary data that can be expected to improve the accuracy and reproducibility of diagnostic procedures. But the true potential of hybrid PET/MR imaging may reside in applications beyond the domain of coronary artery disease. The combination of both modalities in assessment of other cardiac diseases such as inflammation and of other systemic diseases can also be envisioned. It is also predicted that the 2 modalities combined could help characterize atherosclerotic plaques and differentiate plaques with a high risk of rupture from stable plaques. In the future, the development of new tracers will also open new perspectives in evaluating myocardial remodeling and in assessing the kinetics of stem cell therapy in myocardial infarction. New tracers will also provide new means for evaluating alterations in cardiac innervation, angiogenesis, and even the assessment of reporter gene technologies

  12. PET and Recycling

    OpenAIRE

    Funda Sevencan; Songul A. Vaizoglu

    2007-01-01

    This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET) is the most commonly used plastics. PET is used to protect food, drinking water,...

  13. Vasoactive mediators and splanchnic perfusion.

    Science.gov (United States)

    Reilly, P M; Bulkley, G B

    1993-02-01

    To provide an overview of the splanchnic hemodynamic response to circulatory shock. Previous studies performed in our own laboratory, as well as a computer-assisted search of the English language literature (MEDLINE, 1966 to 1991), followed by a selective review of pertinent articles. Studies were selected that demonstrated relevance to the splanchnic hemodynamic response to circulatory shock, either by investigating the pathophysiology or documenting the sequelae. Article selection included clinical studies as well as studies in appropriate animal models. Pertinent data were abstracted from the cited articles. The splanchnic hemodynamic response to circulatory shock is characterized by a selective vasoconstriction of the mesenteric vasculature mediated largely by the renin-angiotensin axis. This vasospasm, while providing a natural selective advantage to the organism in mild-to-moderate shock (preserving relative perfusion of the heart, kidneys, and brain), may, in more severe shock, cause consequent loss of the gut epithelial barrier, or even hemorrhagic gastritis, ischemic colitis, or ischemic hepatitis. From a physiologic standpoint, nonpulsatile cardiopulmonary bypass, a controlled form of circulatory shock, has been found experimentally to significantly increase circulating levels of angiotensin II, the hormone responsible for this selective splanchnic vasoconstriction. While angiotensin II has been viewed primarily as the mediator responsible for the increased total vascular resistance seen during (and after) cardiopulmonary bypass, it may also cause the disproportionate decrease in mesenteric perfusion, as measured in human subjects by intraluminal gastric tonometry and galactose clearance by the liver, as well as the consequent development of the multiple organ failure syndrome seen in 1% to 5% of patients after cardiac surgery.

  14. Electrically heated particulate filter restart strategy

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2011-07-12

    A control system that controls regeneration of a particulate filter is provided. The system generally includes a propagation module that estimates a propagation status of combustion of particulate matter in the particulate filter. A regeneration module controls current to the particulate filter to re-initiate regeneration based on the propagation status.

  15. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    International Nuclear Information System (INIS)

    Lee, Won Yong; Lee, Ki Hyeong; Yoon, Byung Woo; Lee, Sang Bok; Jeon, Beom S.; Lee, Kyung Han; Lee, Myung Chul

    1996-01-01

    Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p 0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

  16. Computerized analysis of brain perfusion parameter images

    International Nuclear Information System (INIS)

    Turowski, B.; Haenggi, D.; Wittsack, H.J.; Beck, A.; Aurich, V.

    2007-01-01

    Purpose: The development of a computerized method which allows a direct quantitative comparison of perfusion parameters. The display should allow a clear direct comparison of brain perfusion parameters in different vascular territories and over the course of time. The analysis is intended to be the basis for further evaluation of cerebral vasospasm after subarachnoid hemorrhage (SAH). The method should permit early diagnosis of cerebral vasospasm. Materials and Methods: The Angiotux 2D-ECCET software was developed with a close cooperation between computer scientists and clinicians. Starting from parameter images of brain perfusion, the cortex was marked, segmented and assigned to definite vascular territories. The underlying values were averages for each segment and were displayed in a graph. If a follow-up was available, the mean values of the perfusion parameters were displayed in relation to time. The method was developed under consideration of CT perfusion values but is applicable for other methods of perfusion imaging. Results: Computerized analysis of brain perfusion parameter images allows an immediate comparison of these parameters and follow-up of mean values in a clear and concise manner. Values are related to definite vascular territories. The tabular output facilitates further statistic evaluations. The computerized analysis is precisely reproducible, i. e., repetitions result in exactly the same output. (orig.)

  17. An experimental phantom study of the effect of gadolinium-based MR contrast agents on PET attenuation coefficients and PET quantification in PET-MR imaging: application to cardiac studies.

    Science.gov (United States)

    O' Doherty, Jim; Schleyer, Paul

    2017-12-01

    Simultaneous cardiac perfusion studies are an increasing trend in PET-MR imaging. During dynamic PET imaging, the introduction of gadolinium-based MR contrast agents (GBCA) at high concentrations during a dual injection of GBCA and PET radiotracer may cause increased attenuation effects of the PET signal, and thus errors in quantification of PET images. We thus aimed to calculate the change in linear attenuation coefficient (LAC) of a mixture of PET radiotracer and increasing concentrations of GBCA in solution and furthermore, to investigate if this change in LAC produced a measurable effect on the image-based PET activity concentration when attenuation corrected by three different AC strategies. We performed simultaneous PET-MR imaging of a phantom in a static scenario using a fixed activity of 40 MBq [18 F]-NaF, water, and an increasing GBCA concentration from 0 to 66 mM (based on an assumed maximum possible concentration of GBCA in the left ventricle in a clinical study). This simulated a range of clinical concentrations of GBCA. We investigated two methods to calculate the LAC of the solution mixture at 511 keV: (1) a mathematical mixture rule and (2) CT imaging of each concentration step and subsequent conversion to LAC at 511 keV. This comparison showed that the ranges of LAC produced by both methods are equivalent with an increase in LAC of the mixed solution of approximately 2% over the range of 0-66 mM. We then employed three different attenuation correction methods to the PET data: (1) each PET scan at a specific millimolar concentration of GBCA corrected by its corresponding CT scan, (2) each PET scan corrected by a CT scan with no GBCA present (i.e., at 0 mM GBCA), and (3) a manually generated attenuation map, whereby all CT voxels in the phantom at 0 mM were replaced by LAC = 0.1 cm -1 . All attenuation correction methods (1-3) were accurate to the true measured activity concentration within 5%, and there were no trends in image

  18. Dynamic contrast enhanced MRI for perfusion quantification

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke

    2002-01-01

    Magnetic resonance imaging, during bolus passage of a paramagnetic contrast agent, is used world-wide to obtain parameters that reflect the pathological state of tissue. Abnormal perfusion occurs in diseases such as stoke and tumour. Consequently, perfusion quantication could have signi cant...... clinical value both in diagnosis and treatment of such pathologies. One approach for perfusion quanti cation involves using the contrast mechanism that a ects the transverse relaxation rates of the magnetization, R2 or R 2 , since this provides the most pronounced effect. However, the linearity between...

  19. Simultaneous PET/MR head–neck cancer imaging: Preliminary clinical experience and multiparametric evaluation

    International Nuclear Information System (INIS)

    Covello, M.; Cavaliere, C.; Aiello, M.; Cianelli, M.S.; Mesolella, M.; Iorio, B.; Rossi, A.; Nicolai, E.

    2015-01-01

    Highlights: • Simultaneous PET/MRI is a suitable tool for head/neck T-staging. • No significant differences have been found for PET measures get by both PET/CT and PET/MRI. • SUV 2D and 3D measures in HN lesion offer comparable estimations. • Multiparametric evaluation allows a complete characterization of HN lesions. - Abstract: Purpose: To evaluate the role of simultaneous hybrid PET/MR imaging and to correlate metabolic PET data with morpho-functional parameters derived by MRI in patients with head–neck cancer. Methods: Forty-four patients, with histologically confirmed head and neck malignancy (22 primary tumors and 22 follow-up) were studied. Patients initially received a clinical exam and endoscopy with direct biopsy. Next patients underwent whole body PET/CT followed by PET/MR of the head/neck region. PET and MRI studies were separately evaluated by two blinded groups (both included one radiologist and one nuclear physician) in order to define the presence or absence of lesions/recurrences. Regions of interest (ROIs) analysis was conducted on the primary lesion at the level of maximum size on metabolic (SUV and MTV), diffusion (ADC) and perfusion (K trans , V e , k ep and iAUC) parameters. Results: PET/MR examinations were successfully performed on all 44 patients. Agreement between the two blinded groups was found in anatomic allocation of lesions by PET/MR (Primary tumors: Cohen's kappa 0.93; Follow-up: Cohen's kappa 0.89). There was a significant correlation between CT-SUV measures and MR (e.g., CT-SUV VOI vs. MR-SUV VOI: ρ = 0.97, p < 0.001 for the entire sample). There was also significant positive correlations between the ROI area, SUV measures, and the metabolic parameters (SUV and MTV) obtained during both PET/CT and PET/MR. A significant negative correlation was observed between ADC and K trans values in the primary tumors. In addition, a significant negative correlation existed between MR SUV and ADC in recurrent tumors

  20. Quantitative assessment of the physical potential of proton beam range verification with PET/CT

    Science.gov (United States)

    Knopf, A.; Parodi, K.; Paganetti, H.; Cascio, E.; Bonab, A.; Bortfeld, T.

    2008-08-01

    A recent clinical pilot study demonstrated the feasibility of offline PET/CT range verification for proton therapy treatments. In vivo PET measurements are challenged by blood perfusion, variations of tissue compositions, patient motion and image co-registration uncertainties. Besides these biological and treatment specific factors, the accuracy of the method is constrained by the underlying physical processes. This phantom study distinguishes physical factors from other factors, assessing the reproducibility, consistency and sensitivity of the PET/CT range verification method. A spread-out Bragg-peak (SOBP) proton field was delivered to a phantom consisting of poly-methyl methacrylate (PMMA), lung and bone equivalent material slabs. PET data were acquired in listmode at a commercial PET/CT scanner available within 10 min walking distance from the proton therapy unit. The measured PET activity distributions were compared to simulations of the PET signal based on Geant4 and FLUKA Monte Carlo (MC) codes. To test the reproducibility of the measured PET signal, data from two independent measurements at the same geometrical position in the phantom were compared. Furthermore, activation depth profiles within identical material arrangements but at different positions within the irradiation field were compared to test the consistency of the measured PET signal. Finally, activation depth profiles through air/lung, air/bone and lung/bone interfaces parallel as well as at 6° to the beam direction were studied to investigate the sensitivity of the PET/CT range verification method. The reproducibility and the consistency of the measured PET signal were found to be of the same order of magnitude. They determine the physical accuracy of the PET measurement to be about 1 mm. However, range discrepancies up to 2.6 mm between two measurements and range variations up to 2.6 mm within one measurement were found at the beam edge and at the edge of the field of view (FOV) of the PET

  1. Quantitative assessment of the physical potential of proton beam range verification with PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Knopf, A; Paganetti, H; Cascio, E; Bortfeld, T [Department of Radiation Oncology, MGH and Harvard Medical School, Boston, MA 02114 (United States); Parodi, K [Heidelberg Ion Therapy Center, Heidelberg (Germany); Bonab, A [Department of Radiology, MGH and Harvard Medical School, Boston, MA 02114 (United States)

    2008-08-07

    A recent clinical pilot study demonstrated the feasibility of offline PET/CT range verification for proton therapy treatments. In vivo PET measurements are challenged by blood perfusion, variations of tissue compositions, patient motion and image co-registration uncertainties. Besides these biological and treatment specific factors, the accuracy of the method is constrained by the underlying physical processes. This phantom study distinguishes physical factors from other factors, assessing the reproducibility, consistency and sensitivity of the PET/CT range verification method. A spread-out Bragg-peak (SOBP) proton field was delivered to a phantom consisting of poly-methyl methacrylate (PMMA), lung and bone equivalent material slabs. PET data were acquired in listmode at a commercial PET/CT scanner available within 10 min walking distance from the proton therapy unit. The measured PET activity distributions were compared to simulations of the PET signal based on Geant4 and FLUKA Monte Carlo (MC) codes. To test the reproducibility of the measured PET signal, data from two independent measurements at the same geometrical position in the phantom were compared. Furthermore, activation depth profiles within identical material arrangements but at different positions within the irradiation field were compared to test the consistency of the measured PET signal. Finally, activation depth profiles through air/lung, air/bone and lung/bone interfaces parallel as well as at 6{sup 0} to the beam direction were studied to investigate the sensitivity of the PET/CT range verification method. The reproducibility and the consistency of the measured PET signal were found to be of the same order of magnitude. They determine the physical accuracy of the PET measurement to be about 1 mm. However, range discrepancies up to 2.6 mm between two measurements and range variations up to 2.6 mm within one measurement were found at the beam edge and at the edge of the field of view (FOV) of the

  2. Quantitative assessment of the physical potential of proton beam range verification with PET/CT.

    Science.gov (United States)

    Knopf, A; Parodi, K; Paganetti, H; Cascio, E; Bonab, A; Bortfeld, T

    2008-08-07

    A recent clinical pilot study demonstrated the feasibility of offline PET/CT range verification for proton therapy treatments. In vivo PET measurements are challenged by blood perfusion, variations of tissue compositions, patient motion and image co-registration uncertainties. Besides these biological and treatment specific factors, the accuracy of the method is constrained by the underlying physical processes. This phantom study distinguishes physical factors from other factors, assessing the reproducibility, consistency and sensitivity of the PET/CT range verification method. A spread-out Bragg-peak (SOBP) proton field was delivered to a phantom consisting of poly-methyl methacrylate (PMMA), lung and bone equivalent material slabs. PET data were acquired in listmode at a commercial PET/CT scanner available within 10 min walking distance from the proton therapy unit. The measured PET activity distributions were compared to simulations of the PET signal based on Geant4 and FLUKA Monte Carlo (MC) codes. To test the reproducibility of the measured PET signal, data from two independent measurements at the same geometrical position in the phantom were compared. Furthermore, activation depth profiles within identical material arrangements but at different positions within the irradiation field were compared to test the consistency of the measured PET signal. Finally, activation depth profiles through air/lung, air/bone and lung/bone interfaces parallel as well as at 6 degrees to the beam direction were studied to investigate the sensitivity of the PET/CT range verification method. The reproducibility and the consistency of the measured PET signal were found to be of the same order of magnitude. They determine the physical accuracy of the PET measurement to be about 1 mm. However, range discrepancies up to 2.6 mm between two measurements and range variations up to 2.6 mm within one measurement were found at the beam edge and at the edge of the field of view (FOV) of the

  3. Brain PET and functional MRI: why simultaneously using hybrid PET/MR systems?

    Science.gov (United States)

    Cecchin, Diego; Palombit, Alessandro; Castellaro, Marco; Silvestri, Erica; Bui, Franco; Barthel, Henryk; Sabri, Osama; Corbetta, Maurizio; Bertoldo, Alessandra

    2017-12-01

    In the last 20 years growing attention has been devoted to multimodal imaging. The recent literature is rich of clinical and research studies that have been performed using different imaging modalities on both separate and integrated positron emission tomography (PET) and magnetic resonance (MR) scanners. However, today, hybrid PET/MR systems measure signals related to brain structure, metabolism, neurochemistry, perfusion, and neuronal activity simultaneously, i.e. in the same physiological conditions. A frequently raised question at meeting and symposia is: "Do we really need a hybrid PET/MR system? Are there any advantages over acquiring sequential and separate PET and MR scans?" The present paper is an attempt to answer these questions specifically in relation to PET combined with functional magnetic resonance imaging (fMRI) and arterial spin labeling. We searched (last update: June 2017) the databases PubMed, PMC, Google Scholar and Medline. We also included additional studies if they were cited in the selected articles. No language restriction was applied to the search, but the reviewed articles were all in English. Among all the retrieved articles, we selected only those performed using a hybrid PET/MR system. We found a total of 17 papers that were selected and discussed in three main groups according to the main radiopharmaceutical used: 18F-fluorodeoxyglucose (18F-FDG) (N.=8), 15O-water (15O-H2O) (N.=3) and neuroreceptors (N.=6). Concerning studies using 18F-FDG, simultaneous PET/fMRI revealed that global aspects of functional organization (e.g. graph properties of functional connections) are partially associated with energy consumption. There are remarkable spatial and functional similarities across modalities, but also discrepant findings. More work is needed on this point. There are only a handful of papers comparing blood flow measurements with PET 15O-H2O and MR arterial spin label (ASL) measures, and they show significant regional CBF differences

  4. Electrical diesel particulate filter (DPF) regeneration

    Science.gov (United States)

    Gonze, Eugene V; Ament, Frank

    2013-12-31

    An exhaust system that processes exhaust generated by an engine includes a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates from the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates within the exhaust as it passes therethrough. Heat generated by combustion of the particulates induces combustion of particulates within the DPF.

  5. Cardiac PET/CT for the diagnosis and prognostic evaluation of coronary artery disease

    International Nuclear Information System (INIS)

    Geronazzo, R.J.; Romero, R.L.; Campisi, R.

    2014-01-01

    Coronary artery disease is considered by de World Health Organization (WHO) to be pandemic. Eighty percent of the deaths occurs secondary to coronary artery disease, stroke and diabetes, thus they can be prevented. All of them are related to the same risk factors. Ischemic heart disease is the mayor cause of death in Argentina in the elderly population. Primary prevention strategies are essential in the health system. Hence, image complementary methods are very important to accomplish risk stratification, secondary prevention and pre-surgical evaluation. Nuclear cardiology has occupied this place through myocardial perfusion studies with radiopharmaceuticals, using SPECT (Single photon emission computed tomography) that have improved the level of sensitivity and specificity with ECG gated. Furthermore, positron emission tomography (PET) can evaluate relative myocardial perfusion, quantify absolute myocardial blood flow and coronary flow reserve. With its capacity to quantify rest-peak stress left ventricular systolic function we can underscore for example “balance ischemia”. By using hybrid PET/CT, also we can get information of coronary artery calcium scoring and coronary angiography. Currently, with the available softwares, we can acquire images in List mode. It means, from a single acquisition, it allows multiple image reconstructions, along with the associated electrocardiographic phase. PET/CT uses radiopharmaceuticals with short physical half life, and in conjunction with the possibility of acquiring in 3D mode, the perfusion studies can be done in a short time and offers lower radiation exposure to the patient. The new softwares for routine correction of misalignments between transmission and emission images have helped to reduce the frequency of artifacts and improve diagnostic accuracy. Hybrid PET/CT technology allows functional evaluation of myocardial perfusion combined with anatomic characterization of the epicardial coronary arteries, thereby

  6. New cardiac cameras: single-photon emission CT and PET.

    Science.gov (United States)

    Slomka, Piotr J; Berman, Daniel S; Germano, Guido

    2014-07-01

    Nuclear cardiology instrumentation has evolved significantly in the recent years. Concerns about radiation dose and long acquisition times have propelled developments of dedicated high-efficiency cardiac SPECT scanners. Novel collimator designs, such as multipinhole or locally focusing collimators arranged in geometries that are optimized for cardiac imaging, have been implemented to enhance photon-detection sensitivity. Some of these new SPECT scanners use solid-state photon detectors instead of photomultipliers to improve image quality and to reduce the scanner footprint. These new SPECT devices allow dramatic up to 7-fold reduction in acquisition times or similar reduction in radiation dose. In addition, new hardware for photon attenuation correction allowing ultralow radiation doses has been offered by some vendors. To mitigate photon attenuation artifacts for the new SPECT scanners not equipped with attenuation correction hardware, 2-position (upright-supine or prone-supine) imaging has been proposed. PET hardware developments have been primarily driven by the requirements of oncologic imaging, but cardiac imaging can benefit from improved PET image quality and improved sensitivity of 3D systems. The time-of-flight reconstruction combined with resolution recovery techniques is now implemented by all major PET vendors. These new methods improve image contrast and image resolution and reduce image noise. High-sensitivity 3D PET without interplane septa allows reduced radiation dose for cardiac perfusion imaging. Simultaneous PET/MR hybrid system has been developed. Solid-state PET detectors with avalanche photodiodes or digital silicon photomultipliers have been introduced, and they offer improved imaging characteristics and reduced sensitivity to electromagnetic MR fields. Higher maximum count rate of the new PET detectors allows routine first-pass Rb-82 imaging, with 3D PET acquisition enabling clinical utilization of dynamic imaging with myocardial flow

  7. Perfusion-induced changes in cardiac contractility depend on capillary perfusion.

    Science.gov (United States)

    Dijkman, M A; Heslinga, J W; Sipkema, P; Westerhof, N

    1998-02-01

    The perfusion-induced increase in cardiac contractility (Gregg phenomenon) is especially found in heart preparations that lack adequate coronary autoregulation and thus protection of changes in capillary pressure. We determined in the isolated perfused papillary muscle of the rat whether cardiac muscle contractility is related to capillary perfusion. Oxygen availability of this muscle is independent of internal perfusion, and perfusion may be varied or even stopped without loss of function. Muscles contracted isometrically at 27 degrees C (n = 7). During the control state stepwise increases in perfusion pressure resulted in all muscles in a significant increase in active tension. Muscle diameter always increased with increased perfusion pressure, but muscle segment length was unaffected. Capillary perfusion was then obstructed by plastic microspheres (15 microns). Flow, at a perfusion pressure of 66.6 +/- 26.2 cmH2O, reduced from 17.6 +/- 5.4 microliters/min in the control state to 3.2 +/- 1.3 microliters/min after microspheres. Active tension developed by the muscle in the unperfused condition before microspheres and after microspheres did not differ significantly (-12.8 +/- 29.4% change). After microspheres similar perfusion pressure steps as in control never resulted in an increase in active tension. Even at the two highest perfusion pressures (89.1 +/- 28.4 and 106.5 +/- 31.7 cmH2O) that were applied a significant decrease in active tension was found. We conclude that the Gregg phenomenon is related to capillary perfusion.

  8. Diagnostic value of 18F-FDG PET and 11C-PIB PET on early stage posterior cortical atrophy

    Directory of Open Access Journals (Sweden)

    Shuai LIU

    2015-08-01

    Full Text Available Background  Posterior cortical atrophy (PCA is a kind of progressive neurodegenerative disease with cortical visual impairment as the first symptom. Because of rare clinical incidence, early onset age, special clinical symptoms and unobvious MRI abnormality, the definitive diagnosis of PCA is difficult. This study used 18F-fluoro-2-deoxy-D-glucose (18F-FDG PET and 11C-Pittsburgh compound B (11C-PIB PET for PCA patients with unobvious MRI abnormality, so as to discuss the value of PET in the early diagnosis of PCA.  Methods  Five patients diagnosed as PCA in our hospital between April 2012 and March 2015 were enrolled in this study. Cognitive function was measured by Mini-Mental State Examination (MMSE, Montreal Cognitive Assessment (MoCA, Activities of Daily Living (ADL and Clock Drawing Test (CDT. Brain MRI, 18F-FDG PET and 11C-PIB PET were performed to analyze glucose metabolism and perfusion of posterior cortex.  Results Neuropsychological tests revealed that the ability of writing, calculating, visuospatial and executive function of all these patients were impaired. Color vision tests showed abnormal results. MRI showed that the posterior atrophy (PA scores were 0-2 (average 1 on the left side and 0-1 (average 0.80 on the right side. The medial temporal atrophy (MTA scores were 1-3 (average 1.80 on the left side and 1-4 (average 2 on the right side. The ventricular enlargement (VE scores were 1-2 (average 1.80 on the left side and 1-2 (average 1.60 on the right side. 18F-FDG PET showed glucose metabolism decreased obviously on bilateral temporo-parieto-occipital cortex, precuneus and cingulate gyrus, and slightly on frontal lobes and subcortical structure. 11C-PIB PET showed radioactive 11C-PIB deposition on bilateral frontal, temporal, parietal and occipital cortex, and the outline of cerebellar cortex was clear.  Conclusions  For PCA patients whose parietal and occipital cortical atrophy is not obvious on MRI, 18F-FDG PET

  9. Myocardial perfusion scintigraphy - possibilities of diagnosing CAD

    International Nuclear Information System (INIS)

    Tsonevska, A.

    1998-01-01

    A reviewing the diagnostic methods used in the intricate process of evaluating CAD patients in a attempt to establish the role played by radionuclide methods in the diagnostic strategy is done. The perfusion cardiotropic radiopharmaceuticals used and the various methods of evaluating myocardial are discussed. Although 210 Tl-chloride is the most widely used myocardial perfusion agent, recently 99m Tc-MIBI is proposed as an alternative because of its advantages. Myocardial perfusion assessment is done by various techniques depending on the specific aim, each of them having its proper advantages and shortcomings. The inference is reached that regardless of the routine practical implementation of myocardial perfusion scintigraphy and comprehensive studies along this line in course, there are problems still not well enough clarified awaiting solution

  10. Regional myocardial perfusion of cardioplegic solutions

    International Nuclear Information System (INIS)

    Eugene, J.; Lyons, K.P.; Ott, R.A.; Gelezunas, V.L.; Chang, C.W.; Kowall, M.G.; Haiduc, N.J.

    1987-01-01

    We compared the regional myocardial perfusion of blood cardioplegic solution (BCP) and crystalloid cardioplegic solution (CCP) in 14 mongrel dogs. Cardiopulmonary bypass was established at 28 degrees C, and a hydraulic occluder was placed around the proximal left anterior descending (LAD) coronary artery. In group 1 (N = 7) collateral coronary arteries were ligated; in group 2 (N = 7) collateral coronary arteries were left in situ. After the aorta was clamped, BCP and CCP were alternately perfused at 200 ml/min. The occluder was inflated to produce moderate, severe, and critical LAD stenosis, and regional perfusion was measured by xenon-133 washout with the Silicon Avalanche Radiation Detector. BCP infusion produced a consistently higher aortic pressure, but CCP flow was better than BCP flow under all conditions, particularly without coronary collaterals. Regional myocardial perfusion of CCP is superior to BCP

  11. MRI of pulmonary perfusion; MRT der Lungenperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany); Risse, F.; Semmler, W. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Medizinische Physik in der Radiologie, Heidelberg (Germany); Schoenberg, S.O.; Reiser, M.F. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Kauczor, H.-U. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany)

    2006-04-15

    Lung perfusion is a crucial prerequisite for effective gas exchange. Quantification of pulmonary perfusion is important for diagnostic considerations and treatment planning in various diseases of the lungs. Besides disorders of pulmonary vessels such as acute pulmonary embolism and pulmonary hypertension, these also include diseases of the respiratory tract and lung tissue as well as pulmonary tumors. This contribution presents the possibilities and technical requirements of MRI for diagnostic work-up of pulmonary perfusion. (orig.) [German] Die Perfusion der Lunge ist eine entscheidende Voraussetzung fuer einen effektiven Gasaustausch. Die Bestimmung der Lungenperfusion ist bei verschiedenen Erkrankungen der Lunge fuer Diagnostik und Therapieplanung bedeutsam. Hierzu zaehlen neben Erkrankungen der Lungengefaesse wie akute Lungenembolie und pulmonale Hypertension ebenso Erkrankungen der Atemwege, des Lungengeruests und Lungentumoren. In diesem Beitrag werden die Moeglichkeiten und technischen Voraussetzungen der MRT zur Diagnostik der Lungenperfusion dargestellt. (orig.)

  12. Quantitation of the critically ischemic zone at risk during acute coronary occlusion using PET

    International Nuclear Information System (INIS)

    Merhige, M.; Garza, D.; Sease, D.; Rowe, R.W.; Tewson, T.; Emran, A.; Bolomey, L.; Gould, K.L.

    1991-01-01

    Critical myocardial ischemia has been defined experimentally during acute coronary occlusion as flow reduction of 50% or more since cellular ATP depletion begins to occur beyond this flow reduction threshold, placing tissue at risk of cellular injury. To test the hypothesis that critically ischemic fractional left ventricular mass can be measured noninvasively with PET, nine dogs were imaged in a multi-slice positron camera using the perfusion tracer 13N-ammonia, while radiolabeled microspheres were injected into the left atrium during acute coronary occlusion. Images were processed using a 50% threshold and the size of the resulting perfusion defect was expressed as a fraction of total left ventricular image volume. The critically ischemic left ventricular fraction determined in vitro from the microsphere perfusion data, ranged from 5% to 30% of the total left ventricular weight and correlated closely with that determined noninvasively by PET with r = 0.94 (y = 1.05X - 2.0%). The authors conclude that the fraction of left ventricular myocardium rendered critically ischemic during acute coronary occlusion can be measured accurately and noninvasively in vivo using perfusion imaging with positron emission tomography

  13. Epithelial and Mesenchymal Tumor Compartments Exhibit In Vivo Complementary Patterns of Vascular Perfusion and Glucose Metabolism

    Directory of Open Access Journals (Sweden)

    Mirco Galiè

    2007-11-01

    Full Text Available Glucose transport and consumption are increased in tumors, and this is considered a diagnostic index of malignancy. However, there is recent evidence that carcinoma-associated stromal cells are capable of aerobic metabolism with low glucose consumption, at least partly because of their efficient vascular supply. In the present study, using dynamic contrast-enhanced magnetic resonance imaging and [F-18]fluorodeoxyglucose (FDG positron emission tomography (PET, we mapped in vivo the vascular supply and glucose metabolism in syngeneic experimental models of carcinoma and mesenchymal tumor. We found that in both tumor histotypes, regions with high vascular perfusion exhibited a significantly lower FDG uptake. This reciprocity was more conspicuous in carcinomas than in mesenchymal tumors, and regions with a high-vascular/low-FDG uptake pattern roughly overlapped with a stromal capsule and intratumoral large connectival septa. Accordingly, mesenchymal tumors exhibited a higher vascular perfusion and a lower FDG uptake than carcinomas. Thus, we provide in vivo evidence of vascular/metabolic reciprocity between epithelial and mesenchymal histotypes in tumors, suggesting a new intriguing aspect of epithelial-stromal interaction. Our results suggests that FDG-PET-based clinical analysis can underestimate the malignity or tumor extension of carcinomas exhibiting any trait of “mesenchymalization” such as desmoplasia or epithelial-mesenchymal transition.

  14. Vicarious audiovisual learning in perfusion education.

    Science.gov (United States)

    Rath, Thomas E; Holt, David W

    2010-12-01

    Perfusion technology is a mechanical and visual science traditionally taught with didactic instruction combined with clinical experience. It is difficult to provide perfusion students the opportunity to experience difficult clinical situations, set up complex perfusion equipment, or observe corrective measures taken during catastrophic events because of patient safety concerns. Although high fidelity simulators offer exciting opportunities for future perfusion training, we explore the use of a less costly low fidelity form of simulation instruction, vicarious audiovisual learning. Two low fidelity modes of instruction; description with text and a vicarious, first person audiovisual production depicting the same content were compared. Students (n = 37) sampled from five North American perfusion schools were prospectively randomized to one of two online learning modules, text or video.These modules described the setup and operation of the MAQUET ROTAFLOW stand-alone centrifugal console and pump. Using a 10 question multiple-choice test, students were assessed immediately after viewing the module (test #1) and then again 2 weeks later (test #2) to determine cognition and recall of the module content. In addition, students completed a questionnaire assessing the learning preferences of today's perfusion student. Mean test scores from test #1 for video learners (n = 18) were significantly higher (88.89%) than for text learners (n = 19) (74.74%), (p audiovisual learning modules may be an efficacious, low cost means of delivering perfusion training on subjects such as equipment setup and operation. Video learning appears to improve cognition and retention of learned content and may play an important role in how we teach perfusion in the future, as simulation technology becomes more prevalent.

  15. Improved exercise myocardial perfusion during lidoflazine therapy

    International Nuclear Information System (INIS)

    Shapiro, W.; Narahara, K.A.; Park, J.

    1983-01-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a study of 6 patients with severe classic angina pectoris, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise

  16. Measurement of myocardial perfusion using magnetic resonance

    DEFF Research Database (Denmark)

    Fritz-Hansen, T.; Jensen, L.T.; Larsson, H.B.

    2008-01-01

    Cardiac magnetic resonance imaging (MRI) has evolved rapidly. Recent developments have made non-invasive quantitative myocardial perfusion measurements possible. MRI is particularly attractive due to its high spatial resolution and because it does not involve ionising radiation. This paper reviews...... myocardial perfusion imaging with MR contrast agents: methods, validation and experiences from clinical studies. Unresolved issues still restrict the use of these techniques to research although clinical applications are within reach Udgivelsesdato: 2008/12/8...

  17. Ventilation-perfused studies using SPECT

    International Nuclear Information System (INIS)

    Zwijnenburg, A.

    1989-01-01

    A method for the quantitative analysis of ventilation-perfusion SPECT studies is decribed and an effort is made to evaluate its usefullness. The technical details of the emthod are described. In the the transaxial reconstructions of the tomographic studies the contour of the lungs is detected and regional values of lung volume, ventilation, perfusion and ventilation-perfusion ratios are calculated. The method is operator independent. The lung volume calculations from the SPECT studies are validated by comparing them with lung volume measurements using the helium dilution technique. A good correlation (r=0.91) was found between the two volumes. SPECT volume was greater than the volume measured with helium dilution, which was attributed to non-gas-containing structures in the. lungs. The use of ventilation-perfusion ratio SPECT is described to evaluate the effect of ionizing radiation on the lungs in patients treated with mantle field irradiation for Hodgkin's disease. Perfusion changes appear as early as 2 months after the start of irradiation. Ventilation changes appear later and relatively minor. No changes are seen outside the radiation portals. The ventilation-perfusion inequality in pulmonary sarcoidosis is treated. It is suggested that the decrease D LCO in these patients may be partly due to an even distribution of ventilation perfusion ratios. An effort is made to establish the properties of a new tracer used for the assessment of the metabolic function of the pulmonary endothelium. The lung uptake of I-123 IMP mimics the distribution of a perfusion tracer and it is suggested that this tracer may be useful for the early detection of pulmonary vascular damage, even when blood flow is still intact. Some aspects of the use of Kr-81m as a ventilation tracer are discussed as well as the effect of noise on Kr-81m SPECT reconstructions. (author). 146 refs.; 39 figs.; 8 tabs

  18. Medical application of PET technology

    International Nuclear Information System (INIS)

    Lim, Sang Moo; Choi, C. W.; An, S. H.; Woo, K. S.; Chung, W. S.; Yang, S. D.; Jun, G. S. and others

    1999-04-01

    We performed following studies using PET technology: 1. Clinical usefulness of [ 18 F]FDG whole body PET in malignant disease 2. Clinical usefulness of quantitative evaluation of F-18-FDG 3. Pilot study of C-11 methionine PET in brain tumor 4. PET study in patients with Parkinson's disease 5. A study on the clinical myocardial PET image. PET gives various metabolic information for the living human body, and is very important, new diagnostic modality. The PET study will give us the information of cancer patients such as early detection of cancer, staging, recurrence detection and characterization of cancer. The quantitative analysis using PET could be applied to evaluate the pathophysiology of various diseases and develop new drugs and develop new radiopharmaceuticals

  19. PET in neuro-oncology

    NARCIS (Netherlands)

    Roelcke, U; Leenders, K.L.

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

  20. Take Care with Pet Reptiles

    Science.gov (United States)

    ... young children. [775 KB] Animals and Health Healthy Pets Healthy People : CDC website with helpful resources and information on health benefits of pets and disease risks Safe Handling Tips for Reptiles ...

  1. Medical application of PET technology

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Moo; Choi, C. W.; An, S. H.; Woo, K. S.; Chung, W. S.; Yang, S. D.; Jun, G. S. and others

    1999-04-01

    We performed following studies using PET technology: 1. Clinical usefulness of [{sup 18}F]FDG whole body PET in malignant disease 2. Clinical usefulness of quantitative evaluation of F-18-FDG 3. Pilot study of C-11 methionine PET in brain tumor 4. PET study in patients with Parkinson's disease 5. A study on the clinical myocardial PET image. PET gives various metabolic information for the living human body, and is very important, new diagnostic modality. The PET study will give us the information of cancer patients such as early detection of cancer, staging, recurrence detection and characterization of cancer. The quantitative analysis using PET could be applied to evaluate the pathophysiology of various diseases and develop new drugs and develop new radiopharmaceuticals.

  2. PET applications in pediatrics

    Energy Technology Data Exchange (ETDEWEB)

    Shulkin, B. L. [Ann Arbor, Univ. of Michigan Medical Center (United States). Pediatric Nuclear Medicine Section

    1997-12-01

    This article summarizes the major PET studies which have been performed in pediatric patients to elucidate and characterize diseases and normal development. Issues special for the application of the technique in children, such as dosimetry, patient preparation, and image acquisition are discussed. Studies of central nervous system (CNS) development and pathology, including epilepsy, intraventricular hemorrhage, neonatal asphyxia, tumors, and effects on the CNS from treatment of other tumors are reviewed. These have contributed information fundamental to their understanding of CNS development and pathology. PET investigations into the pathophysiology of congenital heart disease have begun and hold great promise to aid their understanding of these conditions. The second major area in which PET has been applied is the study of non CNS neoplasms. Neuroblastoma has been investigated with tracers which explore basic biochemical features which characterize this tumor, as well as with tracers which explore biochemical events relatively specific for this malignancy. Other common and uncommon tumors of childhood are discussed. The PET technique has been shown useful for answering questions of clinical relevance for the management of these uncommon neoplasms. PET is likely to continue to aid their understanding of many pediatric diseases and may gain more widespread clinical acceptance as the technology continues to disseminate rapidly.

  3. Combined PET/MRI

    DEFF Research Database (Denmark)

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

    2018-01-01

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

  4. Quantitative perfusion imaging in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Zoellner, F.G.; Gaa, T.; Zimmer, F.; Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M.

    2016-01-01

    Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [de

  5. Insulin degradation products from perfused rat kidney

    International Nuclear Information System (INIS)

    Duckworth, W.C.; Hamel, F.G.; Liepnieks, J.; Peavy, D.; Frank, B.; Rabkin, R.

    1989-01-01

    The kidney is a major site for insulin metabolism, but the enzymes involved and the products generated have not been established. To examine the products, we have perfused rat kidneys with insulin specifically iodinated on either the A14 or the B26 tyrosine. Labeled material from both the perfusate and kidney extract was examined by Sephadex G50 and high-performance liquid chromatography (HPLC). In perfusate from a filtering kidney, 22% of the insulin-sized material was not intact insulin on HPLC. With the nonfiltering kidney, 10.6% was not intact insulin. Labeled material from HPLC was sulfitolyzed and reinjected on HPLC. By use of 125 I-iodo(A14)-insulin, almost all the degradation products contained an intact A-chain. By use of 125 I-iodo(B26)-insulin, several different B-chain-cleaved products were obtained. The material extracted from the perfused kidney was different from perfusate products but similar to intracellular products from hepatocytes, suggesting that cellular metabolism by kidney and liver are similar. The major intracellular product had characteristics consistent with a cleavage between the B16 and B17 amino acids. This product and several of the perfusate products are also produced by insulin protease suggesting that this enzyme is involved in the degradation of insulin by kidney

  6. CT perfusion study of neck lymph nodes

    International Nuclear Information System (INIS)

    Zhong Jin; Liu Jun; Hua Rui; Qiao Hui; Gong Yi

    2011-01-01

    Objective: To study the CT perfusion features of various lymph nodes in the neck. Methods: Dynamic perfusion CT scanning was performed in 83 neck lymph nodes proved by pathology, including tuberculosis lymph nodes, lymphoma and metastatic lymph nodes. The shapes, blood flow modes, and perfusion parameters of these lymph nodes were compared among 3 groups. Statistical analysis of L/T and CT perfusion parameters was performed by one-way ANOVA and LSD test. Results: The values of MTT of tuberculosis lymph nodes, lymphoma and metastatic lymph nodes were (28.13±5.08), (31.08±5.82), and (11.24±5.31) s, respectively. The MTT of metastatic lymph nodes was statistically lower than that of tuberculosis lymph nodes and lymphoma (P -1 · 100 g -1 , respectively. The values of BV were (24.68±2.84), (25.30±3.16), and (25.15± 8.81) ml·100 g -1 respectively. The values of TTP were (40.90±8.85), (40.67±6.45), and (40.98±6.62) s, respectively. There were no significant differences in L/T, BF, BV and TTP among tuberculosis lymph nodes, lymphoma and metastatic lymph nodes (P>0.05). Conclusion: CT perfusion, especially combination functional imaging with perfusion images may be helpful in judging the nature of neck lymph nodes. (authors)

  7. AdVEGF-B186 and AdVEGF-DΔNΔC induce angiogenesis and increase perfusion in porcine myocardium.

    Science.gov (United States)

    Nurro, Jussi; Halonen, Paavo J; Kuivanen, Antti; Tarkia, Miikka; Saraste, Antti; Honkonen, Krista; Lähteenvuo, Johanna; Rissanen, Tuomas T; Knuuti, Juhani; Ylä-Herttuala, Seppo

    2016-11-01

    Coronary heart disease remains a significant clinical problem, and new therapies are needed especially for patients with refractory angina for whom the current therapies do not provide sufficient relief. The aim of this study was to find out if angiogenic gene therapy using new members of the vascular endothelial growth factor (VEGF) family, VEGF-B 186 and VEGF-D ΔNΔC , increase myocardial perfusion as measured by the positron emission tomography (PET) 15 O-imaging, and whether there would be coronary steal effect to the contralateral side. Furthermore, safety of intramyocardial angiogenic adenoviral gene transfer was evaluated. Intramyocardial adenoviral (Ad) VEGF-B 186 or AdVEGF-D ΔNΔC gene transfers were given endovascularly into the porcine posterolateral wall of the left ventricle (n=34). Six days later, PET 15 O-imaging for myocardial perfusion and coronary angiography were performed. AdVEGF-B 186 and AdVEGF-D ΔNΔC induced angiogenesis and increased total microvascular area 1.8-fold (95% CI 0.2 to 3.5) and 2.8-fold (95% CI 1.4 to 4.3), respectively. At rest, perfusion was maintained at normal levels, but at stress, relative perfusion was increased 1.4-fold (95% CI 1.1 to 1.7) for AdVEGF-B 186 and 1.3-fold (95% CI 1.0 to 1.7) for AdVEGF-D ΔNΔC , without causing coronary steal effect in the control area. The therapy was well tolerated and did not lead to any significant changes in laboratory safety parameters. Both AdVEGF-B 186 and AdVEGF-D ΔNΔC gene transfers induced efficient angiogenesis in the myocardium resulting in an increased myocardial perfusion measured by PET. Importantly, local perfusion increase did not induce any coronary steal effect. As such, both treatments seem suitable new candidates for the induction of therapeutic angiogenesis for the treatment of refractory angina. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. PET imaging in multiple sclerosis

    NARCIS (Netherlands)

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

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

  9. PET imaging of inflammation

    International Nuclear Information System (INIS)

    Buscombe, J. R.

    2014-01-01

    Inflammatory diseases are common place and often chronic. Most inflammatory cells have increased uptake of glucose which is enhanced in the presence of local cytokines. Therefore, imaging glucose metabolism by the means of 18F-fluoro-deoxy-glucose (FDG) positron emission tomography (PET) holds significant promise in imaging focal inflammation. Most of the work published involved small series of patients with either vasculitis, sarcoid or rheumatoid arthritis. It would appear that FDG PET is a simple and effective technique to identify inflammatory tissue in these conditions. There is even some work to suggest that by comparing baseline and early post therapy scans clinical outcome can be predicted. This would appear to be true with vasculitis as well as retroperitoneal fibrosis. The number of patients in each study is small but the evidence is compelling enough to recommend FDG PET imaging in the routine care of these patients.

  10. Pet in Clinical oncology

    International Nuclear Information System (INIS)

    Hunsche, A.; Grossman, G.; Santana, M.; Santana, C.; Halkar, R.; Garcia, E.

    2003-01-01

    The utility of the PET (positron emission tomography in clinical oncology has been recognized for more than two decades, locating it as a sensible technique for the diagnosis and the prognosis stratification of the oncology patients. The sensitivity and specificity of the PET in comparation to other image studies have demonstrated to be greater. For some years, there was a restriction of PET because of the high cost of the equipment and the cyclotrons. Nevertheless, the relation of cost/benefits is considered as a priority as this technique offers important clinical information. In this article the results observed when using it in diverse types of cancer, as well as the effectiveness shown in the pre-operating evaluation, the evaluation of residual disease, diagnosis of recurrences, pursuit and prognosis stratification of the patients with cancer. (The author)

  11. Metabolic imaging using PET

    International Nuclear Information System (INIS)

    Kudo, Takashi

    2007-01-01

    There is growing evidence that myocardial metabolism plays a key role not only in ischaemic heart disease but also in a variety of diseases which involve myocardium globally, such as heart failure and diabetes mellitus. Understanding myocardial metabolism in such diseases helps to elucidate the pathophysiology and assists in making therapeutic decisions. As well as providing information on regional changes, PET can deliver quantitative information about both regional and global changes in metabolism. This capability of quantitative measurement is one of the major advantages of PET along with physiological positron tracers, especially relevant in evaluating diseases which involve the whole myocardium. This review discusses major PET tracers for metabolic imaging and their clinical applications and contributions to research regarding ischaemic heart disease and other diseases such as heart failure and diabetic heart disease. Future applications of positron metabolic tracers for the detection of vulnerable plaque are also highlighted briefly. (orig.)

  12. Relationship between collateral circulation and myocardial viability of 18F-FDG PET/CT subtended by chronic total occluded coronary arteries.

    Science.gov (United States)

    Dong, Wei; Li, Jianan; Mi, Hongzhi; Song, Xiantao; Jiao, Jian; Li, Quan

    2018-04-01

    To analyze the relationship between the collateral flow of coronary chronic total occlusion (CTO) and myocardial viability detected by 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging. A prospective analysis of 104 patients diagnosed by coronary angiography. All patients underwent resting myocardial perfusion imaging and PET/CT within 1 week. The collateral circulation was graded with Rentrop classification as no or poor collateral circulation in 16 CTO vessels, moderate collateral circulation in 34 CTO vessels, and good collateral circulation in 69 CTO vessels. Myocardial viability was determined with myocardial perfusion imaging and PET. The patterns were interpreted as mismatch, match and normal perfusion and 18 F-FDG uptake. There was no significant correlation between the severity and extent of perfusion defect, myocardial viability and collateral circulation grade. The myocardial viability was normal in mild and moderate hypokinetic regions and decreased in severe hypokinetic and akinesis-dyskinesis regions. The presence of collateral circulation was a sensitive (89%) but not a specific (31%) sign of myocardial viability. In patients with CTO, collateral circulation does not seem to be an effective way for predicting myocardial viability. Further analysis of PET patterns of viable myocardium is needed to guide further revascularization and predict functional improvement and survival benefit.

  13. Novel PET sensors

    International Nuclear Information System (INIS)

    Cooper, C.R.

    2001-03-01

    This thesis describes the design, synthesis and evaluation of novel molecular sensors that utilize the phenomena of Photoinduced Electron Transfer (PET). PET design can be incorporated into molecules to allow them to selectively bind certain guest molecules. PET works by the modulation of electron potentials within a molecule. Binding events between a host and guest can, if designed suitably, change these potentials enough to cause a transfer of electronic charge within the molecular sensor. This event can be accurately and sensitively monitored by the use of ultra violet or fluorescence spectroscopy. A sensor molecule can be constructed by matching the guest to a suitable receptor site and incorporating this into a molecule containing a fluorophore with the correct electron potential characteristics. By using existing synthetic routes as well as exploiting new pathways these sensor molecules C n be constructed to contain a fluorophore separated from a guest receptor(s) by suitable spacers units. When put together these facets go to creating molecules that by design are sensitive and selective for certain guest molecules or functional groups. This methodology allows the synthetic chemist to rationally design and synthesise PET sensors, tailored to the needs of the guest. In this thesis the synthesis and evaluation of a novel PET sensors for D-glucosamine, disaccharides and fluoride is presented. It is believed that the novel sensors using the PET phenomenon presented in this thesis are a worthwhile extension of previous works undertaken by other groups around the world and shows new pathways to increasingly complex and sophisticated sensor molecular design. (author)

  14. Noninvasive quantification of regional myocardial perfusion with rubidium-82 and positron emission tomography. Exploration of a mathematical model

    International Nuclear Information System (INIS)

    Herrero, P.; Markham, J.; Shelton, M.E.; Weinheimer, C.J.; Bergmann, S.R.

    1990-01-01

    Positron emission tomography (PET) centers without cyclotrons use generator-produced rubidium-82 (82Rb) for assessment of myocardial perfusion. The aim of the present study was to determine whether myocardial blood flow could be assessed quantitatively with 82Rb and PET. Because the myocardial extraction fraction of 82Rb varies inversely and nonlinearly with flow and cannot be measured conveniently with PET, we used an experimentally derived mathematical function defining the relation between single-pass extraction fraction of 82Rb and flow to obviate the necessity of measuring the extraction fraction directly. Myocardial blood flow in absolute terms (ml/g/min) was estimated from dynamic PET scans after intravenous administration of 82Rb in intact dogs and compared with flows measured with radiolabeled microspheres. In 36 comparisons in 13 dogs studied at rest, or after coronary occlusion, reperfusion, or after coronary hyperemia induced with intravenous dipyridamole, over the flow range from 0.2 to 2.0 ml/g/min, estimates of perfusion with rubidium correlated well with flows measured concomitantly with microspheres, although there was a slight underestimation of flow with rubidium (flow by 82Rb = 0.92 x flow by microspheres-0.021, r = 0.83). In general, estimates of flow in ischemic regions were less reliable than estimates for regions with normal flow. Thus, although the relation between myocardial extraction and retention of 82Rb and flow can vary under a variety of physiological and pathophysiological conditions, this study demonstrates the ability to obtain quantitative estimates of myocardial blood flow with 82Rb and PET under carefully defined conditions without measuring the extraction fraction directly

  15. Particulate carbon in the atmosphere

    International Nuclear Information System (INIS)

    Surakka, J.

    1992-01-01

    Carbonaceous aerosols are emitted to the atmosphere in combustion processes. Carbon particles are very small and have a long residence time in the air. Black Carbon, a type of carbon aerosol, is a good label when transport of combustion emissions in the atmosphere is studied. It is also useful tool in air quality studies. Carbon particles absorb light 6.5 to 8 times stronger than any other particulate matter in the air. Their effect on decreasing visibility is about 50 %. Weather disturbances are also caused by carbon emissions e.g. in Kuwait. Carbon particles have big absorption surface and capacity to catalyze different heterogenous reactions in air. Due to their special chemical and physical properties particulate carbon is a significant air pollution specie, especially in urban air. Average particulate carbon concentration of 5.7 μg/m 2 have been measured in winter months in Helsinki

  16. PET and endocrine tumors

    International Nuclear Information System (INIS)

    Rigo, P.; Belhocine, T.; Hustinx, R.; Foidart-Willems, J.

    2000-01-01

    The authors review the main indications of PET examination, and specifically of 18 FDG, in the assessment of endocrine tumors: of the thyroid, of the parathyroid, of the adrenal and of the pituitary glands. Neuroendocrine tumors, gastro-entero-pancreatic or carcinoid tumors are also under the scope. Usually, the most differentiated tumors show only poor uptake of the FDG as they have a weak metabolic and proliferative activity. In the assessment of endocrine tumors, FDG-PET should be used only after most specific nuclear examinations been performed. (author)

  17. Prognostic value of stress myocardial perfusion positron emission tomography: results from a multicenter observational registry.

    Science.gov (United States)

    Dorbala, Sharmila; Di Carli, Marcelo F; Beanlands, Rob S; Merhige, Michael E; Williams, Brent A; Veledar, Emir; Chow, Benjamin J W; Min, James K; Pencina, Michael J; Berman, Daniel S; Shaw, Leslee J

    2013-01-15

    The primary objective of this multicenter registry was to study the prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) and the improved classification of risk in a large cohort of patients with suspected or known coronary artery disease (CAD). Limited prognostic data are available for MPI with PET. A total of 7,061 patients from 4 centers underwent a clinically indicated rest/stress rubidium-82 PET MPI, with a median follow-up of 2.2 years. The primary outcome of this study was cardiac death (n = 169), and the secondary outcome was all-cause death (n = 570). Net reclassification improvement (NRI) and integrated discrimination analyses were performed. Risk-adjusted hazard of cardiac death increased with each 10% myocardium abnormal with mildly, moderately, or severely abnormal stress PET (hazard ratio [HR]: 2.3 [95% CI: 1.4 to 3.8; p = 0.001], HR: 4.2 [95% CI: 2.3 to 7.5; p statistic 0.805 [95% CI: 0.772 to 0.838] to 0.839 [95% CI: 0.809 to 0.869]) and risk reclassification for cardiac death (NRI 0.116 [95% CI: 0.021 to 0.210]), with smaller improvements in risk assessment for all-cause death. In patients with known or suspected CAD, the extent and severity of ischemia and scar on PET MPI provided powerful and incremental risk estimates of cardiac death and all-cause death compared with traditional coronary risk factors. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  18. Regional cortical hyper perfusion on perfusion CT during postical motor deficit: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Hye Jin [Dept. of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2013-08-15

    Postictal neurologic deficit is a well-known complication mimicking the manifestation of a stroke. We present a case of a patient with clinical evidence of Todd's paralysis correlating with reversible postictal parenchymal changes on perfusion CT and magnetic resonance (MR) imaging. In this case, perfusion CT and MR imaging were helpful in the differential diagnosis of stroke-mimicking conditions.

  19. The Groningen hypothermic liver perfusion pump : Functional evaluation of a new machine perfusion system

    NARCIS (Netherlands)

    van der Plaats, A.; Maathuis, M. H. J.; Hart, N. A. 't; Bellekom, A. A.; Hofker, H. S.; van der Houwen, E. B.; Verkerke, G. J.; Leuvenink, H. G. D.; Verdonck, P.; Ploeg, R. J.; Rakhorst, G.

    2006-01-01

    To improve preservation of donor livers, we have developed a portable hypothermic machine perfusion (HMP) system as an alternative for static cold storage. A prototype of the system was built and evaluated on functionality. Evaluation criteria included 24 h of adequate pressure controlled perfusion,

  20. Understanding particulate coating microstructure development

    Science.gov (United States)

    Roberts, Christine Cardinal

    How a dispersion of particulates suspended in a solvent dries into a solid coating often is more important to the final coating quality than even its composition. Essential properties like porosity, strength, gloss, particulate order, and concentration gradients are all determined by the way the particles come together as the coating dries. Cryogenic scanning electron microscopy (cryoSEM) is one of the most effective methods to directly visualize a drying coating during film formation. Using this method, the coating is frozen, arresting particulate motion and solidifying the sample so that it be imaged in an SEM. In this thesis, the microstructure development of particulate coatings was explored with several case studies. First, the effect of drying conditions was determined on the collapse of hollow latex particles, which are inexpensive whiteners for paint. Using cryoSEM, it was found that collapse occurs during the last stages of drying and is most likely to occur at high drying temperatures, humidity, and with low binder concentration. From these results, a theoretical model was proposed for the collapse of a hollow latex particle. CryoSEM was also used to verify a theoretical model for the particulate concentration gradients that may develop in a coating during drying for various evaporation, sedimentation and particulate diffusion rates. This work created a simple drying map that will allow others to predict the character of a drying coating based on easily calculable parameters. Finally, the effect of temperature on the coalescence and cracking of latex coatings was explored. A new drying regime for latex coatings was identified, where partial coalescence of particles does not prevent cracking. Silica was shown to be an environmentally friendly additive for preventing crack formation in this regime.

  1. Cerebral Blood Flow Measurement Using fMRI and PET: A Cross-Validation Study

    Directory of Open Access Journals (Sweden)

    Jean J. Chen

    2008-01-01

    Full Text Available An important aspect of functional magnetic resonance imaging (fMRI is the study of brain hemodynamics, and MR arterial spin labeling (ASL perfusion imaging has gained wide acceptance as a robust and noninvasive technique. However, the cerebral blood flow (CBF measurements obtained with ASL fMRI have not been fully validated, particularly during global CBF modulations. We present a comparison of cerebral blood flow changes (ΔCBF measured using a flow-sensitive alternating inversion recovery (FAIR ASL perfusion method to those obtained using H2O15 PET, which is the current gold standard for in vivo imaging of CBF. To study regional and global CBF changes, a group of 10 healthy volunteers were imaged under identical experimental conditions during presentation of 5 levels of visual stimulation and one level of hypercapnia. The CBF changes were compared using 3 types of region-of-interest (ROI masks. FAIR measurements of CBF changes were found to be slightly lower than those measured with PET (average ΔCBF of 21.5±8.2% for FAIR versus 28.2±12.8% for PET at maximum stimulation intensity. Nonetheless, there was a strong correlation between measurements of the two modalities. Finally, a t-test comparison of the slopes of the linear fits of PET versus ASL ΔCBF for all 3 ROI types indicated no significant difference from unity (P>.05.

  2. Effects of Steroid Hormones on Sex Differences in Cerebral Perfusion.

    Directory of Open Access Journals (Sweden)

    Carmen Ghisleni

    Full Text Available Sex differences in the brain appear to play an important role in the prevalence and progression of various neuropsychiatric disorders, but to date little is known about the cerebral mechanisms underlying these differences. One widely reported finding is that women demonstrate higher cerebral perfusion than men, but the underlying cause of this difference in perfusion is not known. This study investigated the putative role of steroid hormones such as oestradiol, testosterone, and dehydroepiandrosterone sulphate (DHEAS as underlying factors influencing cerebral perfusion. We acquired arterial spin labelling perfusion images of 36 healthy adult subjects (16 men, 20 women. Analyses on average whole brain perfusion levels included a multiple regression analysis to test for the relative impact of each hormone on the global perfusion. Additionally, voxel-based analyses were performed to investigate the sex difference in regional perfusion as well as the correlations between local perfusion and serum oestradiol, testosterone, and DHEAS concentrations. Our results replicated the known sex difference in perfusion, with women showing significantly higher global and regional perfusion. For the global perfusion, DHEAS was the only significant predictor amongst the steroid hormones, showing a strong negative correlation with cerebral perfusion. The voxel-based analyses revealed modest sex-dependent correlations between local perfusion and testosterone, in addition to a strong modulatory effect of DHEAS in cortical, subcortical, and cerebellar regions. We conclude that DHEAS in particular may play an important role as an underlying factor driving the difference in cerebral perfusion between men and women.

  3. How FDG-PET helps making decision for surgery in various difficult subgroups of temporal lobe epilepsy?

    Energy Technology Data Exchange (ETDEWEB)

    Tepmongkol, S [Division of Nuclear Medicine, Department of Radiology and Division of Neurology, Department of Internal Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok (Thailand); Locharernkul, C [Division of Neurology, Department of Internal Medicine, Faculty of Medicine, Chulalongkorn University and Chulalongkorn Comprehensive Epilepsy Program under the patronage of Professor Doctor HRH Princess Chulabhorn, Bangkok (Thailand); Chaiwatanarat, T; Kingpetch, K; Sirisalipoch, S [Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok (Thailand); Limotai, C; Loplumlert, J [Chulalongkorn Comprehensive Epilepsy Program under the patronage of Professor Doctor HRH Princess Chulabhorn, Bangkok (Thailand)

    2007-07-01

    Concordant pre-surgical data are the important predictors of good surgical outcome in patients with localization-related epilepsy. Medically intractable temporal lobe epilepsy with hippocampal sclerosis (HS) and concordant pre-surgical data is straightforward and may not need functional imaging. However, in other instances for example, HS with discordant data (HSD), bilateral HS with discordant data (BHSD), temporal lobe epilepsy with dual pathology (DP), non-lesional temporal lobe epilepsy (NL) are the difficult subgroups. In these groups, functional imaging eg. brain perfusion SPECT or brain PET may play a major role for surgical decision making. To our knowledge, there was no previous data in using FDG-PET in different subgroups as mentioned. Only some previous studies in single subgroup without analyzing impact of PET findings on decision-making have been reported. We thus aim to evaluate the usefulness of FDG-PET in these 4 subgroups.

  4. Perfusion MRI in CNS disease: current concepts

    International Nuclear Information System (INIS)

    Essig, M.; Giesel, F.; Le-Huu, M.; Stieltjes, B.; Tengg, H. von; Weber, M.-A.

    2004-01-01

    Today there are several indications for cerebral perfusion MRI. The major indications routinely used in increasing numbers of imaging centers include cerebrovascular disease, tumor imaging and recently psychiatric disorders. Perfusion MRI is based on the injection of a gadolinium chelate and the rapid acquisition of images as the bolus of contrast agent passes through the blood vessels in the brain. The contrast agent causes a signal change; this signal change over time can be analysed to measure cerebral hemodynamics. The quality of brain perfusion studies is very dependent on the contrast agent used: a robust and strong signal decrease with a compact bolus is needed. MultiHance (gadobenate dimeglumine, Gd-BOPTA) is the first of a new class of paramagnetic MR contrast agents with a weak affinity for serum proteins. Due to the interaction of Gd-BOPTA with serum albumin, MultiHance presents with significantly higher T1- and T2-relaxivities enabling a sharper bolus profile. This article reviews the indications of perfusion MRI and the performance of MultiHance in MR perfusion of different diseases. Previous studies using perfusion MRI for a variety of purposes required the use of double dose of contrast agent to achieve a sufficiently large signal drop to enable the acquisition of a clear input function and the calculation of perfusion rCBV and rCBF maps of adequate quality. Recent studies with Multi-Hance suggest that only a single dose of this agent is needed to cause a signal drop of about 30% which is sufficient to allow the calculation of high quality rCBV and rCBF maps. (orig.)

  5. PET/MR in oncology

    DEFF Research Database (Denmark)

    Balyasnikova, Svetlana; Löfgren, Johan; de Nijs, Robin

    2012-01-01

    of the challenges inherent in this new technology, but focus on potential applications for simultaneous PET/MR in the field of oncology. Methods and tracers for use with the PET technology will be familiar to most readers of this journal; thus this paper aims to provide a short and basic introduction to a number...... be applied together with PET increasing the amount of information about the tissues of interest. The potential clinical benefit of applying PET/MR in staging, radiotherapy planning and treatment evaluation in oncology, as well as the research perspectives for the use of PET/MR in the development of new...

  6. Simultaneous PET and MR imaging

    International Nuclear Information System (INIS)

    Yiping Shao; Cherry, Simon R.; Meadors, Ken; Siegel, Stefan; Silverman, Robert W.; Farahani, Keyvan; Marsden, Paul K.

    1997-01-01

    We have developed a prototype PET detector which is compatible with a clinical MRI system to provide simultaneous PET and MR imaging. This single-slice PET system consists of 48 2x2x10mm 3 LSO crystals in a 38 mm diameter ring configuration that can be placed inside the receiver coil of the MRI system, coupled to three multi-channel photomultipliers housed outside the main magnetic field via 4 m long and 2 mm diameter optical fibres. The PET system exhibits 2 mm spatial resolution, 41% energy resolution at 511 keV and 20 ns timing resolution. Simultaneous PET and MR phantom images were successfully acquired. (author)

  7. [An automatic system controlled by microcontroller for carotid sinus perfusion].

    Science.gov (United States)

    Yi, X L; Wang, M Y; Fan, Z Z; He, R R

    2001-08-01

    To establish a new method for controlling automatically the carotid perfusion pressure. A cheap practical automatic perfusion unit based on AT89C2051 micro controller was designed. The unit, LDB-M perfusion pump and the carotid sinus of an animal constituted an automatic perfusion system. This system was able to provide ramp and stepwise updown perfusion pattern and has been used in the research of baroreflex. It can insure the precision and reproducibility of perfusion pressure curve, and improve the technical level in corresponding medical field.

  8. CDC WONDER: Daily Fine Particulate Matter

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Daily Fine Particulate Matter data available on CDC WONDER are geographically aggregated daily measures of fine particulate matter in the outdoor air, spanning...

  9. PET and PET/CT in malignant melanoma; PET y PET/CT en melanoma maligno

    Energy Technology Data Exchange (ETDEWEB)

    Garcia O, J R [Nuclear Medicine and Molecular Imaging PET/CT, Centro Medico ABC, Mexico D.F. (Mexico)

    2007-07-01

    The advantages that it has the PET/CT are: 1. It diminishes mainly positive false lesions. It identifies physiologic accumulate places. 2. It diminishes in smaller grade false negative. Small injuries. Injuries with low grade concentration. Injure on intense activity areas. 3. Precise anatomical localization of accumulate places. 4. Reduction of the acquisition time. (Author)

  10. Combined PET/MRI

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  11. I Love Petting Zoos!

    Centers for Disease Control (CDC) Podcasts

    2010-03-23

    This Kidtastics podcast helps children learn about how to stay safe and healthy when visiting petting zoos and other animal exhibits.  Created: 3/23/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/23/2010.

  12. PET's indsats under lup

    DEFF Research Database (Denmark)

    Hansen, Peer Henrik

    2006-01-01

    En undersøgelseskommission nedsat i 1999. Fem medlemmer skal undersøge PET's efterretningsvirksomhed i forhold til politiske partier, faglige konflikter og politisk ideologiske bevægelser i Danmark under den kolde krig. Kommissionens rapport forventes færdig næste år. Udgivelsesdato: 2. juli 2006...

  13. Choosing a Pet

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    THE capital boasts countless markets of all kinds,but some of its insect,bird and pet markets immortalize Beijing culture and folkloric traditions.Don’t miss it! The Huasheng Tianqiao Market,south of the famous Panjiayuan Antique Market, was moved a few years ago and rebuilt in the

  14. PET CT and lymphomas

    International Nuclear Information System (INIS)

    Castro, R.

    2012-01-01

    This presentation is about Tc and lymphomas. Classification and clinical cases of various cancer such as gastro duodenal or ulcer, mama, medullary, lymph and neck, leukemia, nodular sclerosis. Metabolic information, anatomical nature of lymphoma and its clinical presentation determine the extent that PET should be used in the patient.

  15. Myocardial perfusion imaging with dual energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); De Cecco, Carlo N. [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncology and Pathology, University of Rome “Sapienza”, Rome (Italy); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Spandorfer, Adam; Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States)

    2016-10-15

    Highlights: • Stress dual-energy sCTMPI offers the possibility to directly detect the presence of myocardial perfusion defects. • Stress dual-energy sCTMPI allows differentiating between reversible and fixed myocardial perfusion defects. • The combination of coronary CT angiography and dual-energy sCTMPI can improve the ability of CT to detect hemodynamically relevant coronary artery disease. - Abstract: Dual-energy CT (DECT) enables simultaneous use of two different tube voltages, thus different x-ray absorption characteristics are acquired in the same anatomic location with two different X-ray spectra. The various DECT techniques allow material decomposition and mapping of the iodine distribution within the myocardium. Static dual-energy myocardial perfusion imaging (sCTMPI) using pharmacological stress agents demonstrate myocardial ischemia by single snapshot images of myocardial iodine distribution. sCTMPI gives incremental values to coronary artery stenosis detected on coronary CT angiography (CCTA) by showing consequent reversible or fixed myocardial perfusion defects. The comprehensive acquisition of CCTA and sCTMPI offers extensive morphological and functional evaluation of coronary artery disease. Recent studies have revealed that dual-energy sCTMPI shows promising diagnostic accuracy for the detection of hemodynamically significant coronary artery disease compared to single-photon emission computed tomography, invasive coronary angiography, and cardiac MRI. The aim of this review is to present currently available DECT techniques for static myocardial perfusion imaging and recent clinical applications and ongoing investigations.

  16. Standardized perfusion value of the esophageal carcinoma and its correlation with quantitative CT perfusion parameter values

    Energy Technology Data Exchange (ETDEWEB)

    Djuric-Stefanovic, A., E-mail: avstefan@eunet.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Saranovic, Dj., E-mail: crvzve4@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Sobic-Saranovic, D., E-mail: dsobic2@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia); Masulovic, D., E-mail: draganmasulovic@yahoo.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Artiko, V., E-mail: veraart@beotel.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia)

    2015-03-15

    Purpose: Standardized perfusion value (SPV) is a universal indicator of tissue perfusion, normalized to the whole-body perfusion, which was proposed to simplify, unify and allow the interchangeability among the perfusion measurements and comparison between the tumor perfusion and metabolism. The aims of our study were to assess the standardized perfusion value (SPV) of the esophageal carcinoma, and its correlation with quantitative CT perfusion measurements: blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) of the same tumor volume samples, which were obtained by deconvolution-based CT perfusion analysis. Methods: Forty CT perfusion studies of the esophageal cancer were analyzed, using the commercial deconvolution-based CT perfusion software (Perfusion 3.0, GE Healthcare). The SPV of the esophageal tumor and neighboring skeletal muscle were correlated with the corresponding mean tumor and muscle quantitative CT perfusion parameter values, using Spearman's rank correlation coefficient (r{sub S}). Results: Median SPV of the esophageal carcinoma (7.1; range: 2.8–13.4) significantly differed from the SPV of the skeletal muscle (median: 1.0; range: 0.4–2.4), (Z = −5.511, p < 0.001). The cut-off value of the SPV of 2.5 enabled discrimination of esophageal cancer from the skeletal muscle with sensitivity and specificity of 100%. SPV of the esophageal carcinoma significantly correlated with corresponding tumor BF (r{sub S} = 0.484, p = 0.002), BV (r{sub S} = 0.637, p < 0.001) and PS (r{sub S} = 0.432, p = 0.005), and SPV of the skeletal muscle significantly correlated with corresponding muscle BF (r{sub S} = 0.573, p < 0.001), BV (r{sub S} = 0.849, p < 0.001) and PS (r{sub S} = 0.761, p < 0.001). Conclusions: We presented a database of the SPV for the esophageal cancer and proved that SPV of the esophageal neoplasm significantly differs from the SPV of the skeletal muscle, which represented a sample of healthy

  17. Particulate Matter: a closer look

    NARCIS (Netherlands)

    Buijsman E; Beck JP; Bree L van; Cassee FR; Koelemeijer RBA; Matthijsen J; Thomas R; Wieringa K; LED; MGO

    2005-01-01

    The summary in booklet form 'Fijn stof nader bekeken' (Particulate Matter: a closer look) , published in Dutch by the Netherlands Environmental Assessment Agency (MNP) and the Environment and Safety Division of the National Institute for Public Health and the Environment (RIVM), has been designed to

  18. Transport phenomena in particulate systems

    CERN Document Server

    Freire, José Teixeira; Ferreira, Maria do Carmo

    2012-01-01

    This volume spans 10 chapters covering different aspects of transport phenomena including fixed and fluidized systems, spouted beds, electrochemical and wastewater treatment reactors. This e-book will be valuable for students, engineers and researchers aiming to keep updated on the latest developments on particulate systems.

  19. Global Particulate Matter Source Apportionment

    Science.gov (United States)

    Lamancusa, C.; Wagstrom, K.

    2017-12-01

    As our global society develops and grows it is necessary to better understand the impacts and nuances of atmospheric chemistry, in particular those associated with atmospheric particulate matter. We have developed a source apportionment scheme for the GEOS-Chem global atmospheric chemical transport model. While these approaches have existed for several years in regional chemical transport models, the Global Particulate Matter Source Apportionment Technology (GPSAT) represents the first incorporation into a global chemical transport model. GPSAT runs in parallel to a standard GEOS-Chem run. GPSAT uses the fact that all molecules of a given species have the same probability of undergoing any given process as a core principle. This allows GPSAT to track many different species using only the flux information provided by GEOS-Chem's many processes. GPSAT accounts for the change in source specific concentrations as a result of aqueous and gas-phase chemistry, horizontal and vertical transport, condensation and evaporation on particulate matter, emissions, and wet and dry deposition. By using fluxes, GPSAT minimizes computational cost by circumventing the computationally costly chemistry and transport solvers. GPSAT will allow researchers to address many pertinent research questions about global particulate matter including the global impact of emissions from different source regions and the climate impacts from different source types and regions. For this first application of GPSAT, we investigate the contribution of the twenty largest urban areas worldwide to global particulate matter concentrations. The species investigated include: ammonium, nitrates, sulfates, and the secondary organic aerosols formed by the oxidation of benzene, isoprene, and terpenes. While GPSAT is not yet publically available, we will incorporate it into a future standard release of GEOS-Chem so that all GEOS-Chem users will have access to this new tool.

  20. Dynamic perfusion patterns in temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Dupont, Patrick; Paesschen, Wim van; Zaknun, John J.; Maes, Alex; Tepmongkol, Supatporn; Locharernkul, Chaichon; Vasquez, Silvia; Carpintiero, Silvina; Bal, C.S.; Dondi, Maurizio

    2009-01-01

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  1. Dynamic perfusion patterns in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, Patrick; Paesschen, Wim van [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); Zaknun, John J. [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); University Hospital of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Maes, Alex [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); AZ Groeninge, Nuclear Medicine, Kortrijk (Belgium); Tepmongkol, Supatporn; Locharernkul, Chaichon [Chulalongkorn University, Nuclear Medicine and Neurology, Bangkok (Thailand); Vasquez, Silvia; Carpintiero, Silvina [Fleni Instituto de Investigaciones Neurologicas, Nuclear Medicine, Buenos Aires (Argentina); Bal, C.S. [All India Institute of Medical Sciences, Nuclear Medicine, New Delhi (India); Dondi, Maurizio [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); Ospedale Maggiore, Nuclear Medicine, Bologna (Italy)

    2009-05-15

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  2. Cardiac tissue engineering using perfusion bioreactor systems

    Science.gov (United States)

    Radisic, Milica; Marsano, Anna; Maidhof, Robert; Wang, Yadong; Vunjak-Novakovic, Gordana

    2009-01-01

    This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is ‘biomimetic’ in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2–4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and high-fidelity models for biological research. PMID:18388955

  3. New SPECT and PET Radiopharmaceuticals for Imaging Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Oyebola O. Sogbein

    2014-01-01

    Full Text Available Nuclear cardiology has experienced exponential growth within the past four decades with converging capacity to diagnose and influence management of a variety of cardiovascular diseases. Single photon emission computed tomography (SPECT myocardial perfusion imaging (MPI with technetium-99m radiotracers or thallium-201 has dominated the field; however new hardware and software designs that optimize image quality with reduced radiation exposure are fuelling a resurgence of interest at the preclinical and clinical levels to expand beyond MPI. Other imaging modalities including positron emission tomography (PET and magnetic resonance imaging (MRI continue to emerge as powerful players with an expanded capacity to diagnose a variety of cardiac conditions. At the forefront of this resurgence is the development of novel target vectors based on an enhanced understanding of the underlying pathophysiological process in the subcellular domain. Molecular imaging with novel radiopharmaceuticals engineered to target a specific subcellular process has the capacity to improve diagnostic accuracy and deliver enhanced prognostic information to alter management. This paper, while not comprehensive, will review the recent advancements in radiotracer development for SPECT and PET MPI, autonomic dysfunction, apoptosis, atherosclerotic plaques, metabolism, and viability. The relevant radiochemistry and preclinical and clinical development in addition to molecular imaging with emerging modalities such as cardiac MRI and PET-MR will be discussed.

  4. Optimization of perfusion studies using Atropine

    International Nuclear Information System (INIS)

    Alvarado, A.N.; Valle, V.M.; Montoya, M.J.; Eskenazi, E.S.; Montiel, M.L.; Cueto, C.C.

    2002-01-01

    The studies of myocardial perfusion require an adequate stress; exercise or pharmacological. Every day, more pharmacological studies are performed, specially in some group of patients (women, AMI, etc). There some drugs that are used for this purpose, as adenosine and dobutamine. However, their cost and the lack of availability and infrastructure in our country do not allow there routinely use. We performed dipyridamol as a pharmacological stress, however in some patients there is a doubt regarding if the pharmacological effect was adequate. Atropine is a drug that is frequently used for different purpose and it is well know its tachycardic response. We present and alternative technique, using dipyridamol-atropine as a protocol of stress perfusion study. Our goal was to correlate the standard dipyridamol -thallium perfusion study and the dipyridamol -atropine-perfusion in patients with chronic coronary disease. We evaluated 6 patients (5 males) with stable angina and chronic coronary disease. A standard dipyridamol-thallium study was performed in all of them. Dipyridamole was administered intravenously at a rate of 0.14 mg/kg/min over 6 min for a total of 0.84 mg/kg body weight. Blood pressure, heart rate, EKG and symptoms were monitored before, during and after the pharmacological infusion. Two minutes after the infusion was completed, the radiotracer was injected intravenously. In the next 6 months, without any modification of the clinical situation (symptoms and therapy) a new dipyridamol study was performed, using 1 mg of atropine after the administration of dipyridamol. There were no differences in the collateral effects and we observed and average increase of 30% in the heart rate in relation with the study using dipyridamol alone. The addition of atropine to the standard dipyridamol perfusion study is safe, cheaper and improved the detection of perfusion defects in patients with coronary artery disease

  5. Cerebral perfusion imaging in HIV positive patients

    International Nuclear Information System (INIS)

    Kundley, Kshama; Chowdhury, D.; Lele, V.R.; Lele, R.D.

    1998-01-01

    Full text: Twelve human immunodeficiency virus (HIV) positive patients were studied by SPECT cerebral perfusion imaging 1 hour post injection of 15 mCi of 99m Tc-ECD under ideal conditions with a triple head gamma camera (Prism 3000 X P LEUHR), fanbeam collimators followed by Folstein Mini Mental Status Examination (FMMSE) and AIDS dementia complex (ADC) staging on the same day. All 12 patients were male, in the age range of 23-45 y (mean 31 y). The infected status was diagnosed by ELISA (10 patients) or Western blot (5 patients). The interval between diagnosis and imaging ranged from 1 month - 35 months (mean 15.3 months). Two patients were alcoholic and 2 were smokers. None of them had CNS disorder clinically. ADC staging and FMMSE could be performed in 4 patients. Two patients were normal (stage 0) and 2 were subclinical (stage 0.5) on ADC staging. FMMSE revealed normal or near normal status (mean score 35; maximum score 36). Cerebral perfusion images were interpreted simultaneously by 3 observers blind towards history and examination using semi-quantitative and quantitative methods by consensus. It revealed multiple areas of hypoperfusion, viz. temporal (11 patients (91 %), parietal 10 patients (83%), frontal 9 patients (75%, pre and post central gyrus 7 patients (58%), occipital 6 patients (50%) cingulate gyrus and cerebellum 5 patients (41%) and thalamic in 2 patients (16%). Hyper perfusion in caudate nuclei was noted in 10 patients (83%). The study reveals presence of multiple perfusion abnormalities on cerebral perfusion imaging in HIV positive patients who have normal/near normal mental status suggesting precedence of perfusion abnormality over clinically apparent mental deficit

  6. Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

    International Nuclear Information System (INIS)

    Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae

    2005-01-01

    Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 ± 8.5%, range:3 ∼ 35%) and mild to moderate severity (-71 ± 42.7%, range:-217 ∼ -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome

  7. Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae [Donga University College of Medicine, Busan (Korea, Republic of)

    2005-02-15

    Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 {+-} 8.5%, range:3 {approx} 35%) and mild to moderate severity (-71 {+-} 42.7%, range:-217 {approx} -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome.

  8. Meta-Analysis of Stress Myocardial Perfusion Imaging

    Science.gov (United States)

    2017-06-06

    Coronary Disease; Echocardiography; Fractional Flow Reserve, Myocardial; Hemodynamics; Humans; Magnetic Resonance Imaging; Myocardial Perfusion Imaging; Perfusion; Predictive Value of Tests; Single Photon Emission Computed Tomography; Positron Emission Tomography; Multidetector Computed Tomography; Echocardiography, Stress; Coronary Angiography

  9. Improved visualization of delayed perfusion in lung MRI

    International Nuclear Information System (INIS)

    Risse, Frank; Eichinger, Monika; Kauczor, Hans-Ulrich; Semmler, Wolfhard; Puderbach, Michael

    2011-01-01

    Introduction: The investigation of pulmonary perfusion by three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was proposed recently. Subtraction images are generated for clinical evaluation, but temporal information is lost and perfusion defects might therefore be masked in this process. The aim of this study is to demonstrate a simple analysis strategy and classification for 3D-DCE-MRI perfusion datasets in the lung without omitting the temporal information. Materials and methods: Pulmonary perfusion measurements were performed in patients with different lung diseases using a 1.5 T MR-scanner with a time-resolved 3D-GRE pulse sequence. 25 3D-volumes were acquired after iv-injection of 0.1 mmol/kg KG Gadolinium-DTPA. Three parameters were determined for each pixel: (1) peak enhancement S n,max normalized to the arterial input function to detect regions of reduced perfusion; (2) time between arterial peak enhancement in the large pulmonary artery and tissue peak enhancement τ to visualize regions with delayed bolus onset; and (3) ratio R = S n,max /τ was calculated to visualize impaired perfusion, irrespectively of whether related to reduced or delayed perfusion. Results: A manual selection of peak perfusion images is not required. Five different types of perfusion can be found: (1) normal perfusion; (2) delayed non-reduced perfusion; (3) reduced non-delayed perfusion; (4) reduced and delayed perfusion; and (5) no perfusion. Types II and IV could not be seen in subtraction images since the temporal information is necessary for this purpose. Conclusions: The analysis strategy in this study allows for a simple and observer-independent visualization and classification of impaired perfusion in dynamic contrast-enhanced pulmonary perfusion MRI by using the temporal information of the datasets.

  10. PET or PET-CT with cancer screening

    International Nuclear Information System (INIS)

    Wang Taisong; Zhao Jinhua; Song Jianhua

    2007-01-01

    At present, cancer screening remains a lot of debate in contemporary medical practice. Many constitutes have done a lot of experiments in cancer screening. The same version is that recommendations and decisions regarding cancer screening should be based on reliable data, not self- approbation. Now, some institutes advocate 18 F-FDG PET or 18 F-FDG PET-CT for cancer screening, here, discussed status quo, potential financial, radiation safety and statistical data in 18 F-FDG PET or 18 F-FDG PET- CT cancer screening. (authors)

  11. {sup 18}FDG PET and acetazolamide-enhanced {sup 99m}Tc-HMPAO SPET in systemic lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Gruenwald, F. [Bonn Univ. (Germany). Inst. fuer Klinische und Experimentelle Nuklearmedizin; Schomburg, A. [Bonn Univ. (Germany). Inst. fuer Klinische und Experimentelle Nuklearmedizin; Badali, A. [Dept. of Dermatology, Univ. of Bonn (Germany); Ruhlmann, J. [Bonn Univ. (Germany). Inst. fuer Klinische und Experimentelle Nuklearmedizin; Pavics, L. [Bonn Univ. (Germany). Inst. fuer Klinische und Experimentelle Nuklearmedizin; Biersack, H.J. [Bonn Univ. (Germany). Inst. fuer Klinische und Experimentelle Nuklearmedizin

    1995-09-01

    In this report, we present the case of a 70-year-old female patient, suffering from SLE without symptoms of CNS involvement. In addition to a SPET study using technetium-99m hexamethylpropylene amine oxime ({sup 99m}Tc-HMPAO) and a PET scan with fluorine-18 deoxyglucose ({sup 18}FDG), a SPET study after acetazolamide injection was performed in order to assess the cerebral perfusion reserve. While the PET scan showed no major abnormalities, and the baseline SPET study revealed only minor changes, the acetazolamide-enhanced SPET study revealed a marked reduction of the cortical perfusion reserve, particularly in both frontal lobes. It is concluded that ``preclinical`` CNS involvement, mainly caused by pathological mechanisms involving the cerebral blood vessels, can be considered to exist in this patient with SLE. (orig.). With 2 figs.

  12. Pharmacological experiment of 13N-ammonia as PET imaging agent

    International Nuclear Information System (INIS)

    Wang Mingfang; Tang Ganghua; Gao Xiao; Li Zhi; Wu Hubing; Huang Zuhan; Jiang Hong; Zhong Jinmei; Wang Quanshi

    2002-01-01

    Objective: To study the pharmacological characteristics of 13 N-ammonia, the clinical PET imaging methods of 13 N-ammonia, and its application in myocardial blood flow perfusion. Methods: The uptakes of 13 N-ammonia in the myocardium and other organs in dogs were measured by whole body scanning and chest dynamic PET scanning. The regional myocardial blood flow (rMBF) in healthy volunteers was also measured by the dynamic and static PET imaging following intravenous bolus administration of 13 N-ammonia. Results: The heart and lungs were the first-pass organs that was found out by PET imaging with 13 N-ammonia in dogs and human volunteers, the highest uptake of 13 N-ammonia in the myocardium was also observed. At 30 s after injection the radioactivity in the blood pool of left and right ventricles reached its peak, at 1 min it began to drop, and at 4-20 min after injection the lower radioactivity was kept on. Regional analysis of PET imaging showed that the myocardial uptake of 13 N-ammonia began at 10 s after injection, and the uptake in the septum wall was higher than that in the lateral wall; but in the septum wall was slightly higher than in the lateral wall at 2 min after injection. The radioactivity in the liver and lungs reached its peak at 30 s and was sharply declined hereafter. The uptake of 13 N-ammonia in the liver and lungs remained at the lower levels and the heart-to-blood, heart-to-liver and heart-to-lung ratios were above 2.0 after 5 min. Whole-body PET scanning for dogs showed that 13 N-ammonia was distributed primarily in the organs with rich blood flow and its clearance was observed in the kidney. The images of regional myocardial blood flow (rMBF) acquired from the dynamic or static PET imaging following intravenous bolus administration of 13 N-ammonia were of no difference. Conclusions: The analysis of distribution of 13 N-ammonia indicates that the heart-to-blood, heart-to-liver and heat-to-lung ratios were high and the PET images were clear

  13. Evaluation of dynamic contrast-enhanced T1-weighted perfusion MRI in the differentiation of tumor recurrence from radiation necrosis

    DEFF Research Database (Denmark)

    Larsen, Anne Vibeke Andrée; Simonsen, Helle J; Law, Ian

    2013-01-01

    INTRODUCTION: To investigate if perfusion measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can be used to differentiate radiation necrosis from tumor recurrence in patients with high-grade glioma. METHODS: The study was approved by the institutional review board...... to measure cerebral blood volume (CBV), blood-brain barrier (BBB) permeability and cerebral blood flow (CBF). Subjects also underwent FDG-PET and lesions were classified as either metabolically active or inactive. Follow-up clinical MRI and lesion histology in case of additional tissue resection was used...... to determine whether lesions were regressing or progressing. RESULTS: Fourteen enhancing lesions could be classified as progressing (11) or regressing (three). An empirical threshold of 2.0 ml/100 g for CBV allowed detection of regressing lesions with a sensitivity of 100 % and specificity of 100 %. FDG-PET...

  14. Increased sinusoidal volume and solute extraction during retrograde liver perfusion

    International Nuclear Information System (INIS)

    Bass, N.M.; Manning, J.A.; Weisiger, R.A.

    1989-01-01

    Retrograde isolated liver perfusion has been used to probe acinar functional heterogeneity, but the hemodynamic effects of backward flow have not been characterized. In this study, extraction of a long-chain fatty acid derivative, 12-N-methyl-7-nitrobenzo-2-oxa-1,3-diazol-amino stearate (12-NBDS), was greater during retrograde than during anterograde perfusion of isolated rat liver. To determine whether hemodynamic differences between anterograde and retrograde perfused livers could account for this finding, the hepatic extracellular space was measured for both directions of flow by means of [ 14 C]sucrose washout during perfusion as well as by direct measurement of [ 14 C]sucrose entrapped during perfusion. A three- to fourfold enlargement of the total hepatic extracellular space was found during retrograde perfusion by both approaches. Examination of perfusion-fixed livers by light microscopy and morphometry revealed that marked distension of the sinusoids occurred during retrograde perfusion and that this accounts for the observed increase in the [ 14 C]sucrose space. These findings support the hypothesis that maximum resistance to perfusate flow in the isolated perfused rat liver is located at the presinusoidal level. In addition, increased transit time of perfusate through the liver and greater sinusoidal surface area resulting from sinusoidal distension may account for the higher extraction of 12-NBDS and possibly other compounds by retrograde perfused liver

  15. Automatic Detection of Myocardial Boundaries in MR Cardio Perfusion Images

    NARCIS (Netherlands)

    Spreeuwers, Luuk; Breeuwer, Marcel

    2001-01-01

    Cardiovascular diseases often result in reduced blood perfusion of the myocardium (MC). Recent advances in MR allow fast recordingof contrast enhanced myocardial perfusion scans. For perfusion analysis the myocardial boundaries must be traced. Currently this is done manually. In this paper a method

  16. Read the Label First: Protect Your Pets

    Science.gov (United States)

    Learn about the importance of reading pet products labels before purchasing and using any product to insure the safety of your pets. Find tips for ways to reduce the changes of pets accessing potentially dangerous products.

  17. Cyclotron/PET project in Uruguay

    International Nuclear Information System (INIS)

    Engler, H.

    2006-01-01

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

  18. PET studies in dementia

    International Nuclear Information System (INIS)

    Herholz, K.

    2003-01-01

    Measurement of local cerebral glucose metabolism (lCMRGlc) by positron emission tomography (PET) and 18 F-2-fluoro-2-deoxy-D-glucose (FDG) has become a standard technique during the past 20 years and is now available at many university hospitals in all highly developed countries. Many studies have documented a close relation between lCMRGlc and localized cognitive functions, such as language and visuoconstructive abilities. Alzheimer's disease (AD) is characterized by regional impairment of cerebral glucose metabolism in neocortical association areas (posterior cingulate, temporoparietal and frontal multimodal association cortex), whereas primary visual and sensorimotor cortex, basal ganglia, and cerebellum are relatively well preserved. In a multicenter study comprising 10 PET centers (Network for Efficiency and Standardization of Dementia Diagnosis, NEST-DD) that employed an automated voxel-based analysis of FDG PET images, the distinction between controls and AD patients was 93% sensitive and 93% specific, and even in very mild dementia (at Mini Mental Status Examination (MMSE) 24 or higher) sensitivity was still 84% at 93% specificity. Significantly abnormal metabolism in mild cognitive deficit (MCI) indicates a high risk to develop dementia within the next two years. Reduced neocortical glucose metabolism can probably be detected with FDG PET in AD on average one year before onset of subjective cognitive impairment. In addition to glucose metabolism, specific tracers for dopamine synthesis ( 18 F-F-DOPA) and for ( 11 C-MP4A) are of interest for differentiation among dementia subtypes. Cortical acetylcholine esterase activity (AChE) activity is significantly lower in patients with AD or with dementia with Lewy bodies (DLB) than in age-matched normal controls. In LBD there is also impairment of dopamine synthesis, similar to Parkinson disease. (author) 115 refs

  19. PET studies in dementia

    Energy Technology Data Exchange (ETDEWEB)

    Herholz, K. [Neurologische Universitaetsklinik and Max-Planck-Inst. fuer neurologische Forschung, Koeln (Germany)

    2003-04-01

    Measurement of local cerebral glucose metabolism (lCMRGlc) by positron emission tomography (PET) and {sup 18}F-2-fluoro-2-deoxy-D-glucose (FDG) has become a standard technique during the past 20 years and is now available at many university hospitals in all highly developed countries. Many studies have documented a close relation between lCMRGlc and localized cognitive functions, such as language and visuoconstructive abilities. Alzheimer's disease (AD) is characterized by regional impairment of cerebral glucose metabolism in neocortical association areas (posterior cingulate, temporoparietal and frontal multimodal association cortex), whereas primary visual and sensorimotor cortex, basal ganglia, and cerebellum are relatively well preserved. In a multicenter study comprising 10 PET centers (Network for Efficiency and Standardization of Dementia Diagnosis, NEST-DD) that employed an automated voxel-based analysis of FDG PET images, the distinction between controls and AD patients was 93% sensitive and 93% specific, and even in very mild dementia (at Mini Mental Status Examination (MMSE) 24 or higher) sensitivity was still 84% at 93% specificity. Significantly abnormal metabolism in mild cognitive deficit (MCI) indicates a high risk to develop dementia within the next two years. Reduced neocortical glucose metabolism can probably be detected with FDG PET in AD on average one year before onset of subjective cognitive impairment. In addition to glucose metabolism, specific tracers for dopamine synthesis ({sup 18}F-F-DOPA) and for ({sup 11}C-MP4A) are of interest for differentiation among dementia subtypes. Cortical acetylcholine esterase activity (AChE) activity is significantly lower in patients with AD or with dementia with Lewy bodies (DLB) than in age-matched normal controls. In LBD there is also impairment of dopamine synthesis, similar to Parkinson disease. (author) 115 refs.

  20. Pet Overpopulation: An Economic Analysis

    OpenAIRE

    Stephen Coate; Brian Knight

    2009-01-01

    This paper considers the problem of pet overpopulation. It develops a tractable dynamic model whose positive predictions square well with key features of the current U.S. market for pets. The model is used to understand, from a welfare economic perspective, the sense in which there is \\overpopulation" of pets and the underlying causes of the problem. The paper also employs the model to consider what policies might be implemented to deal with the problem. A calibrated example is developed to i...

  1. Click synthesis of PET radiopharmaceuticals

    International Nuclear Information System (INIS)

    Xu Mei; Kuang Chunxiang

    2009-01-01

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

  2. Protective coatings for commercial particulates

    DEFF Research Database (Denmark)

    Kindl, B.; Teng, Y.H.; Liu, Y.L.

    1994-01-01

    SiC/Al composites are in large-scale production with Al-Si alloy matrices. The same composites with pure Al or low Si matrices need diffusion barriers on the SiC reinforcement to control the interfacial reaction. The present paper describes various approaches taken to obtain protective coatings...... of alumina and zirconia on SiC particulates by sol-gel techniques. Aqueous and organic precursors have been used. The extent of the reaction, i.e., the Si and Al4C3 content in the matrix, was determined by differential thermal analysis and X-ray diffraction. The reaction rates of some coated particulates...... in liquid Al are decreased by as much as one order of magnitude during the first 15 min of immersion. Pretreatments of the SiC surface, the composition and thickness of the coating interphase and heat treatments of the coated materials have been studied, and are discussed in relation to their effect...

  3. PET and Recycling

    Directory of Open Access Journals (Sweden)

    Funda Sevencan

    2007-08-01

    Full Text Available This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET is the most commonly used plastics. PET is used to protect food, drinking water, fruit juice, alcoholic beverage, and food packing films. By the increasing interest on the environmental effects of plastic wastes, concerns on the recyclable packing materials also grew up. Also the daily use of recyclable containers consisting PET have increased. There are five steps for recycling of plastics. These steps are; using large amounts of plastics, collecting them in a big center, classifying and sorting the plastics, reproducing the polymers and obtaining new products with melted plastics. Providing a healthy recycling of plastics, the consumers should have knowledge and responsibility. The consumer should know what he/she has to do before putting the plastics in the recycling containers. Recycling containers and bags should be placed near the sources of plastic wastes. Consequently, the plastic wastes and environmental problems they cause will be on the agenda in future. [TAF Prev Med Bull. 2007; 6(4: 307-312

  4. PET and Recycling

    Directory of Open Access Journals (Sweden)

    Funda Sevencan

    2007-08-01

    Full Text Available This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET is the most commonly used plastics. PET is used to protect food, drinking water, fruit juice, alcoholic beverage, and food packing films. By the increasing interest on the environmental effects of plastic wastes, concerns on the recyclable packing materials also grew up. Also the daily use of recyclable containers consisting PET have increased. There are five steps for recycling of plastics. These steps are; using large amounts of plastics, collecting them in a big center, classifying and sorting the plastics, reproducing the polymers and obtaining new products with melted plastics. Providing a healthy recycling of plastics, the consumers should have knowledge and responsibility. The consumer should know what he/she has to do before putting the plastics in the recycling containers. Recycling containers and bags should be placed near the sources of plastic wastes. Consequently, the plastic wastes and environmental problems they cause will be on the agenda in future. [TAF Prev Med Bull 2007; 6(4.000: 307-312

  5. Study of lung perfusion in colagenosis

    International Nuclear Information System (INIS)

    Macedo de Carvalho, A.C.; Calegaro, J.U.M.

    1982-01-01

    The lung involvement in the various types of colagenosis has been widely described in the literature. However, the study of lung perfusion utilizing radionuclides has been only mentioned in a few papers. With the intention of ascertaining the importance of the lung perfusion scanning in colagenosis, ten cases were studied, seven of which were females and three males, with the following pathologies: 4 rheumatoid arthritis, 4 systemic lupus eritematosous, 1 scleroderma and 1 scleroderma plus dermatomyositis. The ages of the patients varied from 20 to 73 years, and the duration of the disease from 1 month to 39 years. The lung scanning showed perfusion defects in 100% of the cases, not related with the type of colagenosis, duration of the disease, sex or age. On the other hand, the X rays study showed alterations in only 2 patients (20% of the cases). The ventilatory and respiratory functions were tested on 7 patients showing alteration (mixed pattern with predominance of the restrictive factor) in only one (14.3%), while the other patients were normal (85.7%). The importance of the lung perfusion scanning study in all patients with collagen vascular diseases is emphasized. (author) [es

  6. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas ov...

  7. Study of lung perfusion in colagenosis

    Energy Technology Data Exchange (ETDEWEB)

    Macedo de Carvalho, A C; Calegaro, J U.M. [Fundacao Hospitalar do Distrito Federal, Distrito Federal (Brazil). Unidade de Medicina Nuclear

    1982-07-01

    The lung involvement in the various types of colagenosis has been widely described in the literature. However, the study of lung perfusion utilizing radionuclides has been only mentioned in a few papers. With the intention of ascertaining the importance of the lung perfusion scanning in colagenosis, ten cases were studied, seven of which were females and three males, with the following pathologies: 4 rheumatoid arthritis, 4 systemic lupus eritematosous, 1 scleroderma and 1 scleroderma plus dermatomyositis. The ages of the patients varied from 20 to 73 years, and the duration of the disease from 1 month to 39 years. The lung scanning showed perfusion defects in 100% of the cases, not related with the type of colagenosis, duration of the disease, sex or age. On the other hand, the X rays study showed alterations in only 2 patients (20% of the cases). The ventilatory and respiratory functions were tested on 7 patients showing alteration (mixed pattern with predominance of the restrictive factor) in only one (14.3%), while the other patients were normal (85.7%). The importance of the lung perfusion scanning study in all patients with collagen vascular diseases is emphasized.

  8. Acid perfusion test in gastroesophageal reflux disease

    Energy Technology Data Exchange (ETDEWEB)

    Kaul, B.; Petersen, H.; Grette, K.; Myrvold, H.E.

    1986-01-01

    An acid perfusion test, isotope scanning, endoscopy, and esophageal biopsy were performed in 101 patients with symptoms strongly suggestive of gastroesophageal reflux (GER) disease. A positive acid perfusion test within 30 min (APT) and within 5 min (TAPT) was found in 70.2% and 37.6% of the patients, respectively. A positive APT was found significantly more often in patients with than without endoscopic esophagitis, whereas a positive TAPT was found significantly more often in patients with severe symptoms than in patients with moderate symptoms, and in a significantly higher proportion of patients with than without GER by scintigraphy. Neither the APT nor the TAPT showed any dependency on the presence of histologic esophagitis. Most (97%) patients with a negative acid perfusion test, in addition to typical symptoms, also presented with scintigraphic, endoscopic, or histologic evidence of GER disease. Although it shows that the acid perfusion test, particularly when early positive, may serve as a weak predictor of the severity of GER disease, the present study gives little support to the test's clinical usefulness.

  9. Nuclear cardiology: Myocardial perfusion and function

    International Nuclear Information System (INIS)

    Seldin, D.W.

    1991-01-01

    Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than originally thought, and various strategies have been proposed to clarify the meaning of persistent defects. Pharmacologic intervention with dipyridamole and adenosine has become available as an alternative to exercise, and comparisons with exercise imaging and catheterization results have been described. Thallium itself is no longer the sole single-photon perfusion radiopharmaceutical; two new technetium agents are now widely available. In addition to perfusion studies, advances in the study of ventricular function have been made, including reports of studies performed in conjunction with technetium perfusion studies, new insights into cardiac physiology, and the prognostic and case-management information that function studies provide. Finally, work has continued with monoclonal antibodies for the identification of areas of myocyte necrosis. 41 references

  10. Perfusion Quantification Using Gaussian Process Deconvolution

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke; Have, Anna Szynkowiak; Rasmussen, Carl Edward

    2002-01-01

    The quantification of perfusion using dynamic susceptibility contrast MRI (DSC-MRI) requires deconvolution to obtain the residual impulse response function (IRF). In this work, a method using the Gaussian process for deconvolution (GPD) is proposed. The fact that the IRF is smooth is incorporated...

  11. Extended suicide with a pet.

    Science.gov (United States)

    Cooke, Brian K

    2013-01-01

    The combination of the killing of a pet and a suicide is a perplexing scenario that is largely unexplored in the literature. Many forensic psychiatrists and psychologists may be unaccustomed to considering the significance of the killing of a pet. The subject is important, however, because many people regard their pets as members of their family. A case is presented of a woman who killed her pet dog and herself by carbon monoxide poisoning. The purpose of this article is to provide an initial exploration of the topic of extended suicide with a pet. Forensic mental health evaluations may have a role in understanding the etiology of this event and in opining as to the culpability of individuals who attempt to or successfully kill a pet and then commit suicide. Because the scientific literature is lacking, there is a need to understand this act from a variety of perspectives. First, a social and anthropological perspective will be presented that summarizes the history of the practice of killing of one's pet, with a focus on the ancient Egyptians. A clinical context will examine what relationship animals have to mental illness. A vast body of existing scientific data showing the relevance of human attachment to pets suggests that conclusions from the phenomena of homicide-suicide and filicide-suicide are applicable to extended suicide with a pet. Finally, recommendations will be proposed for both clinical and forensic psychiatrists faced with similar cases.

  12. PET/CT and radiotherapy

    International Nuclear Information System (INIS)

    Messa, C.; CNR, Milano; S. Gerardo Hospital, Monza; Di Muzio, N.; Picchio, M.; Bettinardi, V.; Gilardi, M.C.; CNR, Milano; San Raffaele Scientific Institute, Milano; Fazio, F.; CNR, Milano; San Raffaele Scientific Institute, Milano; San Raffaele Scientific Institute, Milano

    2006-01-01

    This article reviews the state of the art of PET/CT applications in radiotherapy, specifically its use in disease staging, patient selection, treatment planning and treatment evaluation. Diseases for which radiotherapy with radical intent is indicated will be considered, as well as those in which PET/CT may actually change the course of disease. The methodological and technological aspects of PET/CT in radiotherapy are discussed, focusing on the problem of target volume definition with CT and PET functional imaging and the problem of tumor motion with respect to imaging and dose delivery

  13. Volume perfusion CT imaging of cerebral vasospasm: diagnostic performance of different perfusion maps

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Afat, Saif; Nikoubashman, Omid; Mueller, Marguerite; Wiesmann, Martin; Brockmann, Carolin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Schubert, Gerrit Alexander [RWTH Aachen University, Department of Neurosurgery, Aachen (Germany); Bier, Georg [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Brockmann, Marc A. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University Hospital Mainz, Department of Neuroradiology, Mainz (Germany)

    2016-08-15

    In this study, we aimed to evaluate the diagnostic performance of different volume perfusion CT (VPCT) maps regarding the detection of cerebral vasospasm compared to angiographic findings. Forty-one datasets of 26 patients (57.5 ± 10.8 years, 18 F) with subarachnoid hemorrhage and suspected cerebral vasospasm, who underwent VPCT and angiography within 6 h, were included. Two neuroradiologists independently evaluated the presence and severity of vasospasm on perfusion maps on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting <50 %, 2 - vasospasm affecting >50 % of vascular territory). A third neuroradiologist independently assessed angiography for the presence and severity of vasospasm on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting < 50 %, 2 - vasospasm affecting > 50 % of vessel diameter). Perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to drain (TTD) were evaluated regarding diagnostic accuracy for cerebral vasospasm with angiography as reference standard. Correlation analysis of vasospasm severity on perfusion maps and angiographic images was performed. Furthermore, inter-reader agreement was assessed regarding findings on perfusion maps. Diagnostic accuracy for TTD and MTT was significantly higher than for all other perfusion maps (TTD, AUC = 0.832; MTT, AUC = 0.791; p < 0.001). TTD revealed higher sensitivity than MTT (p = 0.007). The severity of vasospasm on TTD maps showed significantly higher correlation levels with angiography than all other perfusion maps (p ≤ 0.048). Inter-reader agreement was (almost) perfect for all perfusion maps (kappa ≥ 0.927). The results of this study indicate that TTD maps have the highest sensitivity for the detection of cerebral vasospasm and highest correlation with angiography regarding the severity of vasospasm. (orig.)

  14. Detectable perfusion changes in MAG3 studies

    International Nuclear Information System (INIS)

    Shuter, B.; Bernar, A.; Roach, P.

    1998-01-01

    Full text: The use of 120 MBq 99m Tc-MAG 3 instead of 600 MBq 99m Tc-DTPA in renal imaging has degraded the images obtained during the perfusion phase. An increase of the minimum detectable change (MDC) in blood flow (BF) would also be expected. In transplant patients, renal BF is an important factor in patient management and the MDC should be small to allow early detection of reduced perfusion. We determined the mean and coefficient of variation (CoV: standard deviation/mean) of three renal perfusion indices as a function of counts in the time-activity curves (TACs). Transplant patients were given a dose of about 300 MBq of 99m Tc-MAG3 and images acquired at 8 fps for 60s. TACs made up from 8, 4, 2 or I images per second allowed calculation of renal perfusion indices as if doses of 300, 150, 75 and 38 MBq had been administered. Perfusion indices based on area under the TACs up to the arterial peak (API), the maximum slopes of the TACs (SPI) and the maximum slope of renal TAC and height of arterial TAC (BPI) were calculated by our routine renal software package. As the administered dose decreased, the CoV rose for all indices, least for BPI and most for API. BPI CoV increased from ∼10% at 300 MBq to 20% at 75 MBq, but API CoV rose from 6% to 46%. Mean BPI was stable over the dose range, but mean API showed a systematic increase of about 50% over the 300 MBq result. We conclude that at 120 MBq the MDC (expressed as 2*CoV) in BF is 30-60%, whereas at 600 MBq it may be as low as 10%, allowing earlier confident detection of a change in BF. The BPI was the preferred perfusion index as its mean value changed little and it had the least CoV at lower activities. The data also imply that relative kidney perfusion in the one individual will be much less accurate with 120 MBq of MAG 3

  15. Perfusion vector - a new method to quantify myocardial perfusion scintigraphy images: a simulation study with validation in patients

    DEFF Research Database (Denmark)

    Minarik, David; Senneby, Martin; Wollmer, Per

    2015-01-01

    Background The interpretation of myocardial perfusion scintigraphy (MPS) largely relies on visual assessment by the physician of the localization and extent of a perfusion defect. The aim of this study was to introduce the concept of the perfusion vector as a new objective quantitative method...

  16. Myocardial perfusion imaging by digital subtraction angiography

    International Nuclear Information System (INIS)

    Kadowaki, Hiroyuki; Ishikawa, Kinji; Ogai, Toshihiro; Katori, Ryo

    1986-01-01

    Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; 1) at the R wave of the electrocardiogram, 2) 100 msec before the R wave, and 3) 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery. In all patients with anterior myocardial infarction, low perfusion was observed at the infarcted portion compared to the non-infarcted myocardium. In patients with inferior myocardial infarction, this low perfusion area was not observed because right coronary angiography was not subjected to DSA in this study. (J.P.N.)

  17. Basic consideration of diffusion/perfusion imaging

    International Nuclear Information System (INIS)

    Tamagawa, Yoichi; Kimura, Hirohiko; Matsuda, Tsuyoshi; Kawamura, Yasutaka; Nakatsugawa, Shigekazu; Ishii, Yasushi; Sakuma, Hajime; Tsukamoto, Tetsuji.

    1990-01-01

    In magnetic resonance imaging (MRI), microscopic motion of biological system such as molecular diffusion of water and microcirculation of blood in the capillary network (perfusion) has been proposed to cause signal attenuation as an intravoxel incoherent motion (IVIM). Quantitative imaging of the IVIM phenomenon was attempted to generate from a set of spin-echo (SE) sequences with or without sensitization by motion probing gradient (MPG). The IVIM imaging is characterized by a parameter, apparent diffusion coefficient (ADC), which is an integration of both the diffusion and the perfusion factor on voxel-by-voxel basis. Hard ware was adjusted to avoid image artifact mainly produced by eddy current. Feasibility of the method was tested using bottle phantom filled with water at different temperature and acetone, and the calculated ADC values of these media corresponded well with accepted values of diffusion. The method was then applied to biological system to investigate mutual participation of diffusion/perfusion on the ADC value. The result of tumor model born on nude mouse suggested considerable participation of perfusion factor which immediately disappeared after sacrificing the animal. Meanwhile, lower value of sacrificed tissue without microcirculation was suggested to have some restriction of diffusion factor by biological tissue. To substantiate the restriction effect on the diffusion, a series of observation have made on a fiber phantom, stalk of celory with botanical fibers and human brain with nerve fibers, in applying unidirectional MPG along the course of these banch of fiber system. The directional restriction effect of diffusion along the course of fiber (diffusion anisotrophy) was clearly visualized as directional change of ADC value. The present method for tissue characterization by diffusion/perfusion on microscopic level will provide a new insight for evaluation of functional derangement in human brain and other organs. (author)

  18. Ventilation-perfusion distribution in normal subjects.

    Science.gov (United States)

    Beck, Kenneth C; Johnson, Bruce D; Olson, Thomas P; Wilson, Theodore A

    2012-09-01

    Functional values of LogSD of the ventilation distribution (σ(V)) have been reported previously, but functional values of LogSD of the perfusion distribution (σ(q)) and the coefficient of correlation between ventilation and perfusion (ρ) have not been measured in humans. Here, we report values for σ(V), σ(q), and ρ obtained from wash-in data for three gases, helium and two soluble gases, acetylene and dimethyl ether. Normal subjects inspired gas containing the test gases, and the concentrations of the gases at end-expiration during the first 10 breaths were measured with the subjects at rest and at increasing levels of exercise. The regional distribution of ventilation and perfusion was described by a bivariate log-normal distribution with parameters σ(V), σ(q), and ρ, and these parameters were evaluated by matching the values of expired gas concentrations calculated for this distribution to the measured values. Values of cardiac output and LogSD ventilation/perfusion (Va/Q) were obtained. At rest, σ(q) is high (1.08 ± 0.12). With the onset of ventilation, σ(q) decreases to 0.85 ± 0.09 but remains higher than σ(V) (0.43 ± 0.09) at all exercise levels. Rho increases to 0.87 ± 0.07, and the value of LogSD Va/Q for light and moderate exercise is primarily the result of the difference between the magnitudes of σ(q) and σ(V). With known values for the parameters, the bivariate distribution describes the comprehensive distribution of ventilation and perfusion that underlies the distribution of the Va/Q ratio.

  19. Ventilation and perfusion display in a single image

    International Nuclear Information System (INIS)

    Lima, J.J.P. de; Botelho, M.F.R.; Pereira, A.M.S.; Rafael, J.A.S.; Pinto, A.J.; Marques, M.A.T.; Pereira, M.C.; Baganha, M.F.; Godinho, F.

    1991-01-01

    A new method of ventilation and perfusion display onto a single image is presented. From the data on regions of interest of the lungs, three-dimensional histograms are created, containing as parameters X and Y for the position of the pixels, Z for the perfusion and colour for local ventilation. The perfusion value is supplied by sets of curves having Z proportional to the local perfusion count rate. Ventilation modulates colour. Four perspective views of the histogram are simultaneously displayed to allow visualization of the entire organ. Information about the normal ranges for both ventilation and perfusion is also provided in the histograms. (orig.)

  20. Characteristics of Brain Perfusion in Patients of Parkinson's Disease

    International Nuclear Information System (INIS)

    Jeong, Young Jin; Park, Min Jung; Kim, Jae Woo; Kang, Young Kang

    2008-01-01

    It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. Two hundred nineteen patients (M: 70, F: 149, mean age: 62.9±6.9 y/o) who were diagnosed as PD without dementia clinically and 55 patients (M: 15, F: 40, mean age: 61.4±9.2 y/o) as normal controls who had no past illness history were performed 99m Tc-HMPAO brain perfusion SPECT and neuropsychological test. At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood

  1. A microvascular compartment model validated using 11C-methylglucose liver PET in pigs

    Science.gov (United States)

    Munk, Ole L.; Keiding, Susanne; Baker, Charles; Bass, Ludvik

    2018-01-01

    The standard compartment model (CM) is widely used to analyse dynamic PET data. The CM is fitted to time-activity curves to estimate rate constants that describe the transport of a tracer between well-mixed compartments. The aim of this study was to develop and validate a more realistic microvascular compartment model (MCM) that includes capillary tracer concentration gradients, backflux from cells into the perfused capillaries and multiple re-uptakes during the passage through a capillary. The MCM incorporates only parameters with clear physiological meaning, it is easy to implement, and it does not require numerical solution. We compared the MCM and CM for the analysis of 3 min dynamic PET data of pig livers (N  =  5) following injection of 11C-methylglucose. During PET scans, the tracer concentrations in blood were measured in the abdominal aorta, portal vein and liver vein by manual sampling. We found that the MCM outperformed the CM and that dynamic PET data include information which cannot be extracted using standard CM. The MCM fitted dynamic PET data better than the CM (Akaike values were 46  ±  4 for best MCM fits, and 82  ±  8 for best CM fits; mean  ±  standard deviation) and extracted physiologically reasonable parameter estimates such as blood perfusion that were in agreement with independent measurements. The difference between model-independent perfusion estimates and the best MCM perfusion estimates was  -0.01  ±  0.05 ml/ml/min, whereas the difference was 0.30  ±  0.13 ml/ml/min using the CM. In addition, the MCM predicted the time course of concentrations in the liver vein, a prediction fundamentally unobtainable using the CM as it does not return tracer backflux from cells to capillary blood. The results demonstrate the benefit of using models that include more physiology and that models including concentration gradients should be preferred when analysing the blood-cell exchange of

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

    DEFF Research Database (Denmark)

    Gerke, Oke; Hermansson, Ronnie; Hess, Søren

    2015-01-01

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

  3. Ultra-low Dose CT for Attenuation Correction of 82Rb Cardiac PET

    DEFF Research Database (Denmark)

    Sørensen, Maria Balshøj; Bouchelouche, Kirsten; Tolbod, Lars Poulsen

    Aim: Myocardial perfusion imaging (MPI) using cardiac PET with tracers like 82Rb and 15O-water is substantially lower in radiation dose than classic MIBI-based SPECT. However, for cardiac PET, the dose contribution of CT for attenuation correction (CTAC) is typically 20-30% of the total dose....... To reduce the total radiation dose of cardiac PET further, we set out to examine if the use of ultra-low dose CTAC (UL-CTAC) would affect the accuracy of the quantitative parameters related to MPI. Furthermore, we examined whether the low quality of the UL-CTAC would affect the technologist’s ability...... to perform manual adjustment for misalignment between PET and CTAC. The CT reconstruction algorithm Q.AC was used to improve quality and consistency of the CTAC. Method: 23 consecutive clinical patients (BMI: 26.9 [range: 15.4-38.8]) referred for 82Rb PET rest and stress imaging were included in the study...

  4. Low-dose myocardial blood flow imaging using 82Rb-PET (RUBILOW 2.0)

    DEFF Research Database (Denmark)

    Hoff, Camilla Molich; Tolbod, Lars Poulsen; Harms, Hans

    2017-01-01

    Aim: Relative and absolute measures of myocardial blood flow (MBF) can be derived from a 82Rb PET/CT scan using list mode data to extract static, gated and dynamic PET series. High doses of 82Rb are used to maximize image quality in especially static images. High doses require large eluate volumes......, may degrade scanner dead time performance at first pass and decreases generator lifetime. Lower doses will expand the availability of 82Rb PET/CT and lower doses to personnel and patients. The aim of the current study was to examine MBF with a low dose (LD) 82Rb protocol compared to the institution......’s standard (STD) protocol. Methods: Twenty-one patients referred to 82Rb PET were included in the study. Patients were examined during rest and stress with repeated LD (740 MBq) and STD dose (1110 MBq) Rb-PET during the same imaging session. Regional and global rest and stress MBF values, total perfusion...

  5. Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

    Energy Technology Data Exchange (ETDEWEB)

    Dowdle, S.C.; Human, D.G.; Mann, M.D. (Univ. of Cape Town (South Africa))

    1990-08-01

    Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis.

  6. Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

    International Nuclear Information System (INIS)

    Dowdle, S.C.; Human, D.G.; Mann, M.D.

    1990-01-01

    Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis

  7. TU-G-BRA-08: BEST IN PHYSICS (JOINT IMAGING-THERAPY): Hybrid PET-MRI Imaging of Acute Radiation Induced Cardiac Toxicity

    International Nuclear Information System (INIS)

    El-Sherif, O; Xhaferllari, I; Gaede, S; Sykes, J; Butler, J; Wisenberg, G; Prato, F

    2015-01-01

    Purpose: To identify the presence of low-dose radiation induced cardiac toxicity in a canine model using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI). Methods: Research ethics board approval was obtained for a longitudinal imaging study of 5 canines after cardiac irradiation. Animals were imaged at baseline, 1 week post cardiac irradiation, and 1 month post cardiac irradiation using a hybrid PET- MRI system (Biograph mMR, Siemens Healthcare). The imaging protocol was designed to assess acute changes in myocardial perfusion and inflammation. Myocardial perfusion imaging was performed using N13-ammonia tracer followed by a dynamic PET acquisition scan. A compartmental tracer kinetic model was used for absolute perfusion quantification. Myocardial inflammation imaging was performed using F18-fluorodeoxyglucose (FDG) tracer. The standard uptake value (SUV) over a region encompassing the whole heart was used to compare FDG scans. All animals received a simulation CT scan (GE Medical Systems) for radiation treatment planning. Radiation treatment plans were created using the Pinncale3 treatment planning system (Philips Radiation Oncology Systems) and designed to resemble the typical cardiac exposure during left-sided breast cancer radiotherapy. Cardiac irradiations were performed in a single fraction using a TrueBeam linear accelerator (Varian Medical Systems). Results: The delivered dose (mean ± standard deviation) to heart was 1.8±0.2 Gy. Reductions in myocardial stress perfusion relative to baseline were observed in 2 of the 5 animals 1 month post radiation. A global inflammatory response 1 month post radiation was observed in 4 of the 5 animals. The calculated SUV at 1 month post radiation was significantly higher (p=0.05) than the baseline SUV. Conclusion: Low doses of cardiac irradiation (< 2 Gy) may lead to myocardial perfusion defects and a global inflammatory response that can be detectable as early as 1 month post irradiation

  8. TU-G-BRA-08: BEST IN PHYSICS (JOINT IMAGING-THERAPY): Hybrid PET-MRI Imaging of Acute Radiation Induced Cardiac Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    El-Sherif, O; Xhaferllari, I; Gaede, S [Western Univeristy, London, ON (United Kingdom); London Regional Cancer Program, London, ON (United Kingdom); Sykes, J; Butler, J [Lawson Health Research Institute, London, ON (United Kingdom); Wisenberg, G; Prato, F [Western Univeristy, London, ON (United Kingdom); Lawson Health Research Institute, London, ON (United Kingdom)

    2015-06-15

    Purpose: To identify the presence of low-dose radiation induced cardiac toxicity in a canine model using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI). Methods: Research ethics board approval was obtained for a longitudinal imaging study of 5 canines after cardiac irradiation. Animals were imaged at baseline, 1 week post cardiac irradiation, and 1 month post cardiac irradiation using a hybrid PET- MRI system (Biograph mMR, Siemens Healthcare). The imaging protocol was designed to assess acute changes in myocardial perfusion and inflammation. Myocardial perfusion imaging was performed using N13-ammonia tracer followed by a dynamic PET acquisition scan. A compartmental tracer kinetic model was used for absolute perfusion quantification. Myocardial inflammation imaging was performed using F18-fluorodeoxyglucose (FDG) tracer. The standard uptake value (SUV) over a region encompassing the whole heart was used to compare FDG scans. All animals received a simulation CT scan (GE Medical Systems) for radiation treatment planning. Radiation treatment plans were created using the Pinncale3 treatment planning system (Philips Radiation Oncology Systems) and designed to resemble the typical cardiac exposure during left-sided breast cancer radiotherapy. Cardiac irradiations were performed in a single fraction using a TrueBeam linear accelerator (Varian Medical Systems). Results: The delivered dose (mean ± standard deviation) to heart was 1.8±0.2 Gy. Reductions in myocardial stress perfusion relative to baseline were observed in 2 of the 5 animals 1 month post radiation. A global inflammatory response 1 month post radiation was observed in 4 of the 5 animals. The calculated SUV at 1 month post radiation was significantly higher (p=0.05) than the baseline SUV. Conclusion: Low doses of cardiac irradiation (< 2 Gy) may lead to myocardial perfusion defects and a global inflammatory response that can be detectable as early as 1 month post irradiation

  9. Progress on dedicated animal PET

    International Nuclear Information System (INIS)

    Liu Wei

    2002-01-01

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

  10. Small Molecule PET-Radiopharmaceuticals

    NARCIS (Netherlands)

    Elsinga, Philip H.; Dierckx, Rudi A. J. O.

    This review describes several aspects required for the development of small molecule PET-tracers. Design and selection criteria are important to consider before starting to develop novel PET-tracers. Principles and latest trends in C-11 and F-18-radiochemistry are summarized. In addition an update

  11. Welfare assessment in pet rabbits

    NARCIS (Netherlands)

    Schepers, F.; Koene, P.; Beerda, B.

    2009-01-01

    One million pet rabbits are kept in The Netherlands, but there are no data available on their behaviour and welfare. This study seeks to assess the welfare of pet rabbits in Dutch households and is a first step in the development of a welfare assessment system. In an internet survey, housing

  12. Selected PET radiomic features remain the same.

    Science.gov (United States)

    Tsujikawa, Tetsuya; Tsuyoshi, Hideaki; Kanno, Masafumi; Yamada, Shizuka; Kobayashi, Masato; Narita, Norihiko; Kimura, Hirohiko; Fujieda, Shigeharu; Yoshida, Yoshio; Okazawa, Hidehiko

    2018-04-17

    We investigated whether PET radiomic features are affected by differences in the scanner, scan protocol, and lesion location using 18 F-FDG PET/CT and PET/MR scans. SUV, TMR, skewness, kurtosis, entropy, and homogeneity strongly correlated between PET/CT and PET/MR images. SUVs were significantly higher on PET/MR 0-2 min and PET/MR 0-10 min than on PET/CT in gynecological cancer ( p = 0.008 and 0.008, respectively), whereas no significant difference was observed between PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min images in oral cavity/oropharyngeal cancer. TMRs on PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min increased in this order in gynecological cancer and oral cavity/oropharyngeal cancer. In contrast to conventional and histogram indices, 4 textural features (entropy, homogeneity, SRE, and LRE) were not significantly different between PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min images. 18 F-FDG PET radiomic features strongly correlated between PET/CT and PET/MR images. Dixon-based attenuation correction on PET/MR images underestimated tumor tracer uptake more significantly in oral cavity/oropharyngeal cancer than in gynecological cancer. 18 F-FDG PET textural features were affected less by differences in the scanner and scan protocol than conventional and histogram features, possibly due to the resampling process using a medium bin width. Eight patients with gynecological cancer and 7 with oral cavity/oropharyngeal cancer underwent a whole-body 18 F-FDG PET/CT scan and regional PET/MR scan in one day. PET/MR scans were performed for 10 minutes in the list mode, and PET/CT and 0-2 min and 0-10 min PET/MR images were reconstructed. The standardized uptake value (SUV), tumor-to-muscle SUV ratio (TMR), skewness, kurtosis, entropy, homogeneity, short-run emphasis (SRE), and long-run emphasis (LRE) were compared between PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min images.

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

    Science.gov (United States)

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

    2016-01-01

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

  14. Neurotransmission imaging by PET

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Akihiro; Suhara, Tetsuya [National Inst. of Radiological Sciences, Chiba (Japan)

    2001-08-01

    PET studies on neurotransmission in psychological disorders to evaluate abnormal neurotransmission and therapeutic effects are thoroughly reviewed by type of major neurotransmitters. Studies on dopaminergic neurotransmission have focused on the function of dopamine D{sub 2} receptors, receptor subtypes, such as the D{sub 1} receptor, and ligands, such as transporters. PET studies of dopamine D{sub 2} receptor, which began in the early 1980s, have predominantly been performed in schizophrenia, and most have failed to detect any statistically significant differences between schizophrenia patients and controls. The studies in the early 1980s were performed by using [{sup 11}C]N-methyl-spiperone (NMSP) and [{sup 11}C]raclopride, ligands for striatal dopamine D{sub 2} receptors. [{sup 11}C]FLB457, which has much higher affinity for D{sub 2} receptors than raclopride, began to be used in the 1990s. Dopamine D{sub 2} occupancy after drug ingestion has also been investigated to clarify the mechanisms and effects of antipsychotic drugs, and there have also been studies on the effect of aging and personality traits on dopamine D{sub 2} receptor levels in healthy subjects. In studies on dopamine receptor subtypes other than D{sub 2}, dopamine D{sub 1} receptors have been studied in connection with assessments of cognitive functions. Most studies on dopamine transporters have been related to drug dependence. Serotonin 5-HT{sub 2A} receptors have been studied with [{sup 11}C]NMSP in schizophrenia patients, while studies of another serotonin receptor subtype, 5-HT{sub 1A} receptors, have been mainly conducted in patients with depression. [{sup 11}C]NMSP PET showed no difference between schizophrenia patients who had not undergone phamacotherapy and normal subjects. Because serotonin selective reuptake inhibitors (SSRIs) affect serotonin transporters, and abnormalities in serotonin transporters detected in mood disorders, PET ligands for serotonin transporters have increasingly

  15. Neurotransmission imaging by PET

    International Nuclear Information System (INIS)

    Takano, Akihiro; Suhara, Tetsuya

    2001-01-01

    PET studies on neurotransmission in psychological disorders to evaluate abnormal neurotransmission and therapeutic effects are thoroughly reviewed by type of major neurotransmitters. Studies on dopaminergic neurotransmission have focused on the function of dopamine D 2 receptors, receptor subtypes, such as the D 1 receptor, and ligands, such as transporters. PET studies of dopamine D 2 receptor, which began in the early 1980s, have predominantly been performed in schizophrenia, and most have failed to detect any statistically significant differences between schizophrenia patients and controls. The studies in the early 1980s were performed by using [ 11 C]N-methyl-spiperone (NMSP) and [ 11 C]raclopride, ligands for striatal dopamine D 2 receptors. [ 11 C]FLB457, which has much higher affinity for D 2 receptors than raclopride, began to be used in the 1990s. Dopamine D 2 occupancy after drug ingestion has also been investigated to clarify the mechanisms and effects of antipsychotic drugs, and there have also been studies on the effect of aging and personality traits on dopamine D 2 receptor levels in healthy subjects. In studies on dopamine receptor subtypes other than D 2 , dopamine D 1 receptors have been studied in connection with assessments of cognitive functions. Most studies on dopamine transporters have been related to drug dependence. Serotonin 5-HT 2A receptors have been studied with [ 11 C]NMSP in schizophrenia patients, while studies of another serotonin receptor subtype, 5-HT 1A receptors, have been mainly conducted in patients with depression. [ 11 C]NMSP PET showed no difference between schizophrenia patients who had not undergone phamacotherapy and normal subjects. Because serotonin selective reuptake inhibitors (SSRIs) affect serotonin transporters, and abnormalities in serotonin transporters detected in mood disorders, PET ligands for serotonin transporters have increasingly been developed, and serotonin transporters have recently begun to be

  16. Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

    Energy Technology Data Exchange (ETDEWEB)

    Tutcu, Semra [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey); Serter, Selim, E-mail: serterselim@gmail.co [Department of Radiology, Celal Bayar University, School of Medicine, Manisa (Turkey); Kaya, Yavuz; Kara, Eray [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey); Nese, Nalan [Department of Pathology, Celal Bayar University, School of Medicine, Manisa (Turkey); Pekindil, Goekhan [Department of Radiology, Celal Bayar University, School of Medicine, Manisa (Turkey); Coskun, Teoman [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey)

    2010-08-15

    Purpose: It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT. Materials and methods: Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses. Results: In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance. Conclusion: The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.

  17. Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

    International Nuclear Information System (INIS)

    Tutcu, Semra; Serter, Selim; Kaya, Yavuz; Kara, Eray; Nese, Nalan; Pekindil, Goekhan; Coskun, Teoman

    2010-01-01

    Purpose: It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT. Materials and methods: Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses. Results: In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance. Conclusion: The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.

  18. A capillary-based perfusion phantom for simulation of brain perfusion for MRI

    International Nuclear Information System (INIS)

    Maciak, A.; Kronfeld, A.; Mueller-Forell, W.; Wille, C.; Kempski, O.; Stoeter, P.

    2010-01-01

    Purpose: The measurement of the CBF is a non-standardized procedure and there are no reliable gold standards. This abstract shows a capillary-based perfusion-phantom for CE-DSC-MRI. It has equivalent flow properties to those within the tissue capillary system of the human brain and allows the validation of the Siemens Perfusion (MR) software. Materials and Methods: The perfusion phantom consists of a dialyzer for the simulation of the capillary system, a feeding tube for simulation of the AIF and a pulsatile pump for simulation of the heart. Using this perfusion phantom, the exact determination of the gold standard CBF due to the well-known geometry of the phantom is easy. It was validated based on different perfusion measurements. These measurements were investigated with standard software (Siemens Perfusion MR). The software determined the CBF within the capillary system. Based on this CBF, a comparison to the gold standard was made with several different flow speeds. After AIF selection, a total of 726 CBF data points were automatically extracted by the software. Results: This results in a comparison of the gold standard CBF to these 726 CBF values. Therefore, a reproducible and reliable deviation estimation between gold standard CBF and measured CBF using the software was computed. It can be shown that the deviation between gold standard and software-based evaluation ranges between 1 and 31 %. Conclusion: There is no significance for any correlation between flow speed and amount of deviation. The mean measured CBF is 11.4 % higher than the gold standard CBF (p-value < 0.001). Using this kind of perfusion-phantom, the validation of different software systems allows reliable conclusions about their quality. (orig.)

  19. Can preoperative myocardial perfusion scintigraphy predict changes in left ventricular perfusion and function after coronary artery bypass graft surgery?

    DEFF Research Database (Denmark)

    Eckardt, Rozy; Kjeldsen, Bo Juel; Johansen, Allan

    2012-01-01

    OBJECTIVESWe wanted to evaluate whether preoperative myocardial perfusion scintigraphy (MPS) could predict changes in cardiac symptoms and postoperative myocardial perfusion and left ventricular function after coronary artery bypass grafting (CABG).METHODSNinety-two patients with stable angina...... in 26%. Left ventricular ejection fraction (LVEF), which was normal before operation in 45%, improved in 40% of all patients. The increase in LVEF was not related to the preoperative pattern of perfusion defects. Of 30 patients with normalized perfusion after CABG, 29 (97%) had reversible defects...... that reversible or partly reversible perfusion defects at a preoperative MPS have a high chance of normalized myocardial perfusion assessed by MPS 6 months after operation. Normal perfusion is obtained almost exclusively in territories with reversible ischaemia. Symptoms improved in nearly all patients and LVEF...

  20. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

    2015-07-15

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  1. Study of the correlation of IVIM parameter maps with FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Delso, Gaspar, E-mail: gaspar.delso@usz.ch [GE Healthcare, Waukesha, WI (United States); Lee, Sangwoo [GE Healthcare, Waukesha, WI (United States); Porto, Miguel; Hüllner, Martin; Veit-Haibach, Patrick [Department of Medical Imaging, University Hospital, Zurich (Switzerland)

    2014-01-11

    Intravoxel incoherent motion (IVIM) is a magnetic resonance technique to quantify the influence of microscopic perfusion-related motion and differentiate it from pure molecular diffusion. IVIM has the potential to provide valuable clinical information about microcirculation in the capillary network of healthy tissues as well as malignant tumors. Our goal was to study the correlation of IVIM parameter maps with concurrent FDG-PET data, in view of their potential use in clinical PET/MR protocols. Methods: Data were acquired from ten oncology patients using a tri-modality setup and fitted with a bi-exponential model. The fitting was first solved in the least squares sense and then again using iteratively reweighted least squares. The resulting parameter maps were compared with PET FDG data by an experienced radiologist. Results: Among the pathologies encountered in our patient population were lesions of the liver, spleen, kidney, abdominal wall, prostate and cervix. The qualitative comparison with PET confirmed that IVIM maps provide complementary information about functional inhomogeneity within the tumor. Visual inspection by experienced radiologists showed improved reading of tumor heterogeneity in six of our ten patients when considering FDG uptake together with perfusion fraction maps. The use of a large set of b values was instrumental for data validation and outlier rejection. Robust fitting was shown to increase the accuracy of the fit in 70% of the voxels, leading to average changes of IVIM parametric maps: perfusion fraction f∈[3.9×10{sup –3}, 4.7×10{sup −2}], diffusion coefficient D ∈[−1.2×10{sup −4}, −3.0×10{sup −6}] and pseudo-diffusion coefficient D{sup *}∈[−1.6×10{sup −1}, −9.2×10{sup −3}]. Conclusions: The results suggest that IVIM imaging could be successfully integrated in clinical PET/MR protocols. Clinical validation shows the complementarity of obtained parameter maps with concurrent FDG PET data. Ongoing work is

  2. PIXE analysis of vehicle exhaust particulate

    International Nuclear Information System (INIS)

    Shi Xianfeng; Yao Huiying; Liu Bo; Sun Minde; Xu Huawei; Mi Yong; Shen Hao

    2001-01-01

    PIXE technique on the analysis of vehicle exhaust particulate is introduced. The clement composition and concentration of particulate are obtained. Some elements which are related to environmental pollution such as sulfur lead, silicon and manganese, were analyzed and discussed in detail by PIXE technique Nowadays although unleaded gasoline is widely used, the lead concentration is still very high in exhaust particulate. The concentrations of silicon and manganese in exhaust particulate from different model vehicles are also quite high from measurements. It shows that an evidence for exhaust pollution control could be provided from this work

  3. Quantitative aspects of myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Vogel, R.A.

    1980-01-01

    Myocardial perfusion measurements have traditionally been performed in a quantitative fashion using application of the Sapirstein, Fick, Kety-Schmidt, or compartmental analysis principles. Although global myocardial blood flow measurements have not proven clinically useful, regional determinations have substantially advanced our understanding of and ability to detect myocardial ischemia. With the introduction of thallium-201, such studies have become widely available, although these have generally undergone qualitative evaluation. Using computer-digitized data, several methods for the quantification of myocardial perfusion images have been introduced. These include orthogonal and polar coordinate systems and anatomically oriented region of interest segmentation. Statistical ranges of normal and time-activity analyses have been applied to these data, resulting in objective and reproducible means of data evaluation

  4. Nursing implications for Hepatic arterial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Ellender, R.

    1999-01-01

    Nurses working in Nuclear Medicine assist in Hepatic Artery Catheter (HAC) perfusion studies. This scan is not widely performed in Australia, the St George hospital for example performs approximately five per year. The purpose of this article is firstly to review the indications and rationale of HAC patency studies. Secondly, this article will stress the clinical implications for the Nuclear Medicine Nurse during this study. Emphasis will be placed on the importance of patient education during the procedure. A brief overview of hepatic anatomy and the radiopharmaceuticals administered during the scan is discussed. Finally, a step by step protocol is presented to show how the perfusion/ shunt study is performed. Copyright (1999) The Australian and New Zealand Society of Nuclear Medicine Inc

  5. Perfusion lung scintigraphy in primary pulmonary hypertension

    International Nuclear Information System (INIS)

    Ogawa, Y.; Hayashida, K.; Uehara, T.; Shimonagata, T.; Nishimura, T.; Osaka Univ., Suita

    1993-01-01

    15 cases of primary pulmonary hypertension were classified into two groups by patterns of perfusion lung scintigraphy. Perfusion scintigrams showed multiple, small, ill-defined defects (mottled + ve) pattern in eight cases, and the remaining seven cases had a normal (mottled - ve) pattern. The mean pulmonary arterial pressure in patients with a mottled pattern (54 ± 10 mmHg) was higher than in those with a normal pattern (42 ± 9 mmHg, p < 0.05). There were no significant differences between the two groups in right ventricular ejection fraction, partial pressures of oxygen in the arterial blood or alveolo-arterial oxygen difference. All the patients with a mottled pattern died within 2 years following the lung scintigraphy. There was a significant difference in the survival curves between the two groups. (author)

  6. Perfusion lung scintigraphy in primary pulmonary hypertension

    International Nuclear Information System (INIS)

    Ogawa, Yoji; Nishimura, Tsunehiko; Kumita, Shin-ichirou; Hayashida, Kohei; Uehara, Toshiisa; Shimonagata, Tsuyoshi; Ohno, Akira

    1991-01-01

    Fifteen cases with primary pulmonary hypertension (PPH) were classified into two groups by using the perfusion lung scan pattern. Eight cases had multiple, small, ill-defined defects (mottled pattern), and remaining seven cases had no mottled pattern. These two groups were compared with mean pulmonary arterial pressure (mean PAP), right ventricular ejection fraction (RVEF), blood gas at room air (PaO 2 ), and alveolar-arterial O 2 difference (A-aDo 2 ). The cases with mottled pattern showed a significant increase in mean PAP. There were no significant differences in RVEF, PaO 2 , and A-aDo 2 , between the groups. The survival rate of the patients with mottled pattern was significantly lower than that without mottled pattern (p<0.05). We concluded that perfusion lung scan is very useful for evaluation of the prognosis in primary pulmonary hypertension. (author)

  7. Cerebral perfution studies; Estudios de Perfusion Cerebral

    Energy Technology Data Exchange (ETDEWEB)

    Mut, Fernando [Universidad de la Republica, Montevideo (Uruguay). Centro de Medicina Nuclear

    1994-12-31

    For detecting in precocious form a coronary disease is necessary to aply a diagnostic techniques. The main considerations to be indicated in the present work are: physiological considerations, myocardial perfusion studies with radiotracers such as Talio 201, 99mTc, MIBI, 99mTc-Teboroxima, 99mTc-Fosfinas, instrumentation for obtain good images, proceedings protocols, studies interpretation, standards, SPECT, anomalies standards, coronary diseases.

  8. Myocardial perfusion imaging in hyperthrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Moorin, B.

    1998-01-01

    Full text: Patients with Hyperthrophic Cardiomyopathy (HCM) frequently suffer from syncope and cardiac arrest which may lead to sudden death. This is most often caused by ventricular arrhythmia's in adults, however in young patients the mechanisms are thought to be different. Ischaemia may play a significant role even in young asymptomatic HCM patients. The mechanisms of ischaemic development in HCM differ from those in the 'normal' myocardium (Due to intramural small vessel abnormalities and abnormal myocellular architecture). In HCM the coronary microcirculation is most often affected and massive hypertrophy means more energy is required to promote contraction thus increasing oxygen demand and compounding the effects of any ischaemic changes. A case of a 12 year old HCM patient is presented who has symptoms of syncope associated with exercise whose mother died suddenly of cardiac arrest developed from HCM. A myocardial perfusion rest/stress study was undertaken to detect any underlying myocardial ischaemia. Myocardial perfusion scintigraphy demonstrates any reduction in the microcirculation in addition to that present in the macrocirculation, unlike angiography which will only detect the latter. In this case the scan clearly showed evidence of ischaemia in the lateral wall and this may be an explanation for her episodes of syncope. We suggest an algorithm or the routine work-up of young patients with HCM which makes aggressive use of myocardial perfusion imaging to detect ischaemic changes. This may identify patients who are at higher risk and will assist with treatment decisions. We feel myocardial perfusion scintigraphy is a sensitive non-invasive accurate method of detecting microcirculatory ischaemia and is thus invaluable in HCM patients

  9. Regional cerebral perfusion in cardiovascular reflex syncope

    International Nuclear Information System (INIS)

    Toeyry, J.P.; Kuikka, J.T.; Laensimies, E.A.

    1997-01-01

    Little is known about the regional cerebral perfusion in subjects with presyncope or syncope, and the impact that autonomic nervous dysfunction has on it. Seven subjects with cardiovascular vasodepressor reflex syncope were studied. A baseline test was performed with the patients standing in the 70 upright position, while the passive head-up tilt table test with and without isoprenaline infusion was employed for provocation. Regional cerebral perfusion was assessed by means of single-photon emission tomography with technetium-99m labelled V-oxo-1,2-N,N 1 -ethylenedylbis-l-cysteine diethylester (baseline, and during blood pressure decline in the provocation test) and the autonomic nervous function by means of spectral analysis of heart rate variability (baseline, and before blood pressure decline in the provocation test). Every subject showed an abrupt decline in blood pressure in the provocation test (five with presyncope and two with syncope). The systolic and diastolic blood pressures decreased significantly (P<0.001) between the baseline and the provocation study time points (radiopharmaceutical injection and lowest systolic blood pressure). Mean cerebral perfusion as average count densities decreased upon provocation as compared with baseline (190±63 vs 307±90 counts/voxel, respectively, P=0.013). Hypoperfusion was most pronounced in the frontal lobe. These results suggest that cerebral perfusion decreases markedly during presyncope or syncope with systemic blood pressure decline in subjects with cardiovascular vasodepressor syncope. Furthermore, the autonomic nervous function remains unchanged before the systemic blood pressure decline. (orig.). With 3 figs., 2 tabs

  10. Myocardial perfusion studies in coronary diseases

    International Nuclear Information System (INIS)

    Mut, Fernando

    1994-01-01

    For detecting in precocious form a coronary disease is necessary to apply a diagnostic techniques. The main considerations to be indicated in the present work are: physiological considerations, myocardial perfusion studies with radiotracers such as Talio 201, 99mTc, MIBI, 99mTc-Teboroxima, 99mTc-Fosfinas, instrumentation for obtain good images,proceedings protocols, studies interpretation, standards, SPECT, anomalies standards, coronary diseases

  11. Gamma camera based FDG PET in oncology

    International Nuclear Information System (INIS)

    Park, C. H.

    2002-01-01

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

  12. Non-contrast MRI perfusion angiosome in diabetic feet

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jie [Cardiovascular Imaging Lab, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Hastings, Mary K.; Mueller, Michael J. [Washington University School of Medicine, The Program in Physical Therapy, St. Louis, MO (United States); Muccigross, David; Hildebolt, Charles F. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Fan, Zhaoyang [Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Los Angeles, CA (United States); Gao, Fabao [West China Hospital, Sichuan University, Department of Radiology, Chengdu (China); Curci, John [Washington University School of Medicine, The Department of Surgery, St. Louis, MO (United States)

    2015-01-15

    The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

  13. Non-contrast MRI perfusion angiosome in diabetic feet

    International Nuclear Information System (INIS)

    Zheng, Jie; Hastings, Mary K.; Mueller, Michael J.; Muccigross, David; Hildebolt, Charles F.; Fan, Zhaoyang; Gao, Fabao; Curci, John

    2015-01-01

    The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

  14. Comparison of different references for brain perfusion SPECT quantification in clinical routine

    International Nuclear Information System (INIS)

    Olivera J, P.; Acton, P.; Costa, D.

    1997-01-01

    Full text: We used 40 brain perfusion SPECT studies from the INM, UCL database to investigate the performance of several references (denominators) in the calculation of perfusion ratios with single photon emission tomography (S PET) within a routine clinical service. According to clinical diagnosis and previous SPECT findings 4 groups were identified composed of: 10 controls (C, 23 to 84 y old); 10 myalgic-encephalomyelitis / chronic fatigue syndrome (ME/CFS, 22 to 61 y old); 10 major depression (MD, 24 to 68 y old); and 10 temporal lobe epilepsy (TLE, 19 to 39 y old). Routine protocols for processing were used and the analysis was blind to group classification. Brain perfusion ratios were calculated using 7 different references: hemi cerebellum with higher counts (Cer), total counts in a 4 pixel slice through the basal ganglia slice (BG), average counts per pixel in the visual cortex (VC), average counts per pixel in the white matter (WM), total acquired counts (TAC), total reconstructed counts (TRC) and maximum counts per pixel in the entire study (MAXX). Unpaired test to compare different diagnostic groups, coefficient of variation (CV) to assess the reliability to each references followed by ANOVA were the statistical test used. The lowest mean CV's were found with VC (4.8%) and TRC (5.1%), with all the others significantly higher (p<0.0001). The range of CV's for Cer was the lowest (3.7% to 5.9%). Consistent differentiation between diagnostic groups and controls was only obtained with Cer. In conclusion, it appears that for clinical routine services Cer is the most reliable reference, exception made for all diseases affecting the cerebellum. In these cases TRC or VC should be preferred. (authors)

  15. Combining functional CT and FDG PET allows the calculation of FDG extraction fraction and hepatic glucose phosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, M R [Centre for Medical and Health Physics, Queensland University of Technology (Australia); Wesley Research Institute, QLD (Australia); Miles, K A [Centre for Medical and Health Physics, Queensland University of Technology (Australia); Wesley Research Institute, QLD (Australia); Southern X-ray Clinics, Brisbane [Australia; Keith, C J [Wesley Research Institute, QLD (Australia)

    2002-09-01

    Perfusion data from Functional CT and FDG-PET data may be combined to provide additional information about the uptake of FDG. We have developed methods to calculate FDG extraction fraction in tissues and to quantify hepatic glucose phosphorylation in the liver. Extraction fraction: Functional CT and FDG-PET studies were used to obtain measurements of perfusion and glucose uptake respectively within ten pulmonary nodules. The net influx constant (Ki) was determined from SUV measurements for each lung mass Extraction fraction (E) for each mass lesion was determined from: E=Ki/(Px[1-Hct]). A pixel by pixel calculation allowed generation of extraction fraction maps. The extraction fraction measurements ranged (median) from 0.6% to 4.81% (2.7%). The values for a benign nodule and an organising pneumonia were 0.6% and 0.71% respectively. Extraction fraction measurements for the malignant nodules ranged from 2.01% to 4.81%. A clearer separation of benign and malignant lesions is seen with E values rather than with SUV. Hepatic Glucose Phosphorylation: Functional CT and FDG-PET were utilised to obtain measurements of perfusion and glucose uptake respectively within the livers of a series of 35 patients with colorectal cancer. Hepatic perfusion and the net influx constant were incorporated into FDG kinetic analysis to determine hepatic glucose phosphorylation fraction. SUV and Ki were significantly lower in the 12 patients with advanced disease (p=0.015 and p=0.013 respectively) whereas portal and total hepatic perfusion were increased (p=0.013 and p=0.008 respectively). Combining the PET and CT data yielded phosphorylation fractions of 1.14% and 0.74% for early and advanced disease respectively (p=0.002). By combining functional CT measurements of blood flow with PET measurements of FDG uptake, it is possible to calculate the extraction fraction of FDG and Hepatic glucose phosphorylation. The use of the extraction fraction has improved the distinction between malignant and

  16. Combining functional CT and FDG PET allows the calculation of FDG extraction fraction and hepatic glucose phosphorylation

    International Nuclear Information System (INIS)

    Griffiths, M.R.; Miles, K.A.; Keith, C.J.

    2002-01-01

    Perfusion data from Functional CT and FDG-PET data may be combined to provide additional information about the uptake of FDG. We have developed methods to calculate FDG extraction fraction in tissues and to quantify hepatic glucose phosphorylation in the liver. Extraction fraction: Functional CT and FDG-PET studies were used to obtain measurements of perfusion and glucose uptake respectively within ten pulmonary nodules. The net influx constant (Ki) was determined from SUV measurements for each lung mass Extraction fraction (E) for each mass lesion was determined from: E=Ki/(Px[1-Hct]). A pixel by pixel calculation allowed generation of extraction fraction maps. The extraction fraction measurements ranged (median) from 0.6% to 4.81% (2.7%). The values for a benign nodule and an organising pneumonia were 0.6% and 0.71% respectively. Extraction fraction measurements for the malignant nodules ranged from 2.01% to 4.81%. A clearer separation of benign and malignant lesions is seen with E values rather than with SUV. Hepatic Glucose Phosphorylation: Functional CT and FDG-PET were utilised to obtain measurements of perfusion and glucose uptake respectively within the livers of a series of 35 patients with colorectal cancer. Hepatic perfusion and the net influx constant were incorporated into FDG kinetic analysis to determine hepatic glucose phosphorylation fraction. SUV and Ki were significantly lower in the 12 patients with advanced disease (p=0.015 and p=0.013 respectively) whereas portal and total hepatic perfusion were increased (p=0.013 and p=0.008 respectively). Combining the PET and CT data yielded phosphorylation fractions of 1.14% and 0.74% for early and advanced disease respectively (p=0.002). By combining functional CT measurements of blood flow with PET measurements of FDG uptake, it is possible to calculate the extraction fraction of FDG and Hepatic glucose phosphorylation. The use of the extraction fraction has improved the distinction between malignant and

  17. Phosphorus NMR of isolated perfused morris hepatomas

    International Nuclear Information System (INIS)

    Graham, R.A.; Meyer, R.A.; Brown, T.R.; Sauer, L.A.

    1986-01-01

    The authors are developing techniques for the study of perfused solid tumors by NMR. Tissue-isolated solid hepatomas were grown to 1-2 cm diameter as described previously. The arterial supply was isolated and the tumors perfused (0.5 - 1.0 ml/min) in vitro at 25 C with a 15% suspension of red blood cells in Krebs-Henseliet solution. 31 P-NMR spectra were acquired at 162 MHz in a specially-designed NMR probe using a solenoidal coil. Intracellular pH (monitored from the chemical shift of inorganic phosphate) and ATP levels were stable for up to 6 hrs during perfusion. During 30 min of global ischemia, ATP decreased by 75% and pH fell from 7.0 to 6.7. These changes were reversed by 1 hr reperfusion. In addition to ATP and phosphate, the spectra included a large resonance due to phosphomonoesters, as well as peaks consistent with glycerylphosphocholine, glyceryl-phosphoethanolamine, phosphocreatine, NAD, and UDPG. However, the most novel feature of the spectra was the presence of an unidentified peak in the phosphonate region (+ 16.9 ppm). The peak was not present in spectra of muscle, liver, brain, kidney, or fat tissues excised from the same animals. They are presently attempting to identify the compound that gives rise to this peak and to establish its metabolic origin

  18. Can perfusion SPECT aid CTPA interpretation?

    International Nuclear Information System (INIS)

    Gradinscak, D. J.; Roach, P.; Bailey, E.; Kueh, S.

    2009-01-01

    Full text:Objective: To determine whether fusion of perfusion SPECT and CTPA improves the diagnostic accuracy of CTPA. Methods: 35 patients with suspected PE who underwent both CTPA and SPECT V/Q within 48 hours were included. Of these, the majority (n=30) had PE as determined by the V/Q SPECT scan and the others (n=5) were negative for PE. The clinical reports of CTPA were reviewed and pulmonary emboli tabulated based on anatomical location. A second radiologist, blinded to the results of the clinical read and the V/Q SPECT scan, reviewed the CTPA with and without perfusion SPECT fusion for assistance. Results: A total 57 PE were reported on the clinical reports and 60 PE identified on the blinded read. Fused CTPA/perfursion SPECT images identified a further 5 PE not identified on the clinical read (8% increase) and 2 PE not identified on the blinded read (3% increase). The additional emboli detected resulted in a change in final diagnosis from PE negative to PE positive in 2 patients (6%) compared with the clinical read and 1 patient (3%) compared with the blinded read without SPECT fusion. Conclusion: Fused CTPA-SPECT perfusion improves the sensitivity of CTPA for the detection of PE in a small number of patients. Fused data may help guide the radiologist to identify sites of PE on CTPA.

  19. Cerebral perfusion in homogeneity in normal volunteers

    International Nuclear Information System (INIS)

    Gruenwald, S.M.; Larcos, G.

    1998-01-01

    Full text: In the interpretation of cerebral perfusion scans, it is important to know the normal variation in perfusion which may occur between the cerebral hemispheres. For this reason 24 normal volunteers with no neurological or psychiatric history, and who were on no medications, had 99m Tc-HMPAO brain SPECT studies using a single headed gamma camera computer system. Oblique, coronal and sagittal images were reviewed separately by two experienced observers and any differences were resolved by consensus. Semi-quantitation was performed by summing two adjacent oblique slices and drawing right and left mirror image ROIs corresponding to the mid section level of anterior and posterior frontal lobes, anterior and posterior parietal lobes, temporal lobes and cerebellum. From the mean counts per pixel, right: left ROI ratios and ROI: cerebellar ratios were calculated. On qualitative review 6/24 subjects had mild asymmetry in tracer distribution between right and left cerebral lobes. Semi-quantitation revealed a 5-10% difference in counts between right and left ROIs in 12/24 subjects and an additional three subjects had 10-20% difference in counts between right and left temporal lobes. This study demonstrates the presence of mild asymmetry of cerebral perfusion in a significant minority of normal subjects

  20. Neuropsychiatry: PET and SPECT

    International Nuclear Information System (INIS)

    Quintana F, Juan Carlos

    2002-01-01

    Functional brain imaging with PET and SPECT have a definitive and well established role in the investigation of a variety of conditions such as dementia, epilepsy and drug addiction. With these methods it is possible to detect early rCBF (regional Cerebral Blood Flow) changes seen in dementia (even before clinical symptoms) and differentiate Alzheimer's disease from other dementias by means of the rCBF pattern change. 18-F-FDG PET imaging is a useful tool in partial epilepsy because both rCBF and brain metabolism are compromised at the epileptogenic focus. During the seizure, rCBF dramatically increases locally. Using SPECT it is possible to locate such foci with 97% accuracy. In drug addiction, particularly with cocaine, functional imaging has proven to be very sensitive to detect brain flow and metabolism derangement early in the course of this condition. These findings are important in many ways: prognostic value, they are used as a powerful reinforcement tool and to monitor functional recovery with rehabilitation. There are many other conditions in which functional brain imaging is of importance such as acute stroke treatment assessment, trauma rehabilitation and in psychiatric and abnormal movement diseases specially with the development of receptor imaging (au)

  1. FDG PET imaging dementia

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Byeong Cheol [Kyungpook National University Medical School and Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2007-04-15

    Dementia is a major burden for many countries including South Korea, where life expectancy is continuously growing and the proportion of aged people is rapidly growing. Neurodegenerative disorders, such as, Alzheimer disease, dementia with Lewy bodies, frontotemporal dementia. Parkinson disease, progressive supranuclear palsy, corticobasal degeneration, Huntington disease, can cause dementia, and cerebrovascular disease also can cause dementia. Depression or hypothyroidism also can cause cognitive deficits, but they are reversible by management of underlying cause unlike the forementioned dementias. Therefore these are called pseudodementia. We are entering an era of dementia care that will be based upon the identification of potentially modifiable risk factors and early disease markers, and the application of new drugs postpone progression of dementias or target specific proteins that cause dementia. Efficient pharmacologic treatment of dementia needs not only to distinguish underlying causes of dementia but also to be installed as soon as possible. Therefore, differential diagnosis and early diagnosis of dementia are utmost importance. F-18 FDG PET is useful for clarifying dementing diseases and is also useful for early detection of the disease. Purpose of this article is to review the current value of FDG PET for dementing diseases including differential diagnosis of dementia and prediction of evolving dementia.

  2. FDG PET imaging dementia

    International Nuclear Information System (INIS)

    Ahn, Byeong Cheol

    2007-01-01

    Dementia is a major burden for many countries including South Korea, where life expectancy is continuously growing and the proportion of aged people is rapidly growing. Neurodegenerative disorders, such as, Alzheimer disease, dementia with Lewy bodies, frontotemporal dementia. Parkinson disease, progressive supranuclear palsy, corticobasal degeneration, Huntington disease, can cause dementia, and cerebrovascular disease also can cause dementia. Depression or hypothyroidism also can cause cognitive deficits, but they are reversible by management of underlying cause unlike the forementioned dementias. Therefore these are called pseudodementia. We are entering an era of dementia care that will be based upon the identification of potentially modifiable risk factors and early disease markers, and the application of new drugs postpone progression of dementias or target specific proteins that cause dementia. Efficient pharmacologic treatment of dementia needs not only to distinguish underlying causes of dementia but also to be installed as soon as possible. Therefore, differential diagnosis and early diagnosis of dementia are utmost importance. F-18 FDG PET is useful for clarifying dementing diseases and is also useful for early detection of the disease. Purpose of this article is to review the current value of FDG PET for dementing diseases including differential diagnosis of dementia and prediction of evolving dementia

  3. Acute myocardial infarction associated with intravenous dipyridamole for rubidium-82 PET imaging

    International Nuclear Information System (INIS)

    Marwick, T.H.; Hollman, J.

    1990-01-01

    This report describes the occurrence of chest pain and electrocardiographic features of acute myocardial infarction following intravenous dipyridamole-handgrip stress. Myocardial perfusion imaging (Rb-82 PET) demonstrated a stress-induced perfusion defect. Following failure to respond to medical therapy, urgent cardiac catheterization demonstrated total occlusion of the left anterior descending coronary artery. The vessel was revascularized, with limitation of myocardial damage evidenced by failure to develop anterior Q waves and only modest elevation of cardiac enzyme levels. Complications of intravenous dipyridamole stress are rare, this case constituting the first major problem in over 500 such procedures at this institution. However, this experience demonstrates the importance of vigilant observation during the performance of this technique

  4. Airborne particulate matter in spacecraft

    Science.gov (United States)

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  5. Dans le tourbillon des particules

    CERN Document Server

    Zito, Marco

    2015-01-01

    Accélérateurs géants, détecteurs complexes, particules énigmatiques... La physique subatomique peut sembler bien intimidante pour le novice. Et pourtant, qui n a jamais entendu parler du boson de Higgs et du CERN, le laboratoire européen où il a été découvert en 2012 ? Nul besoin d être un spécialiste pour comprendre de quoi il s agit. Aujourd hui, une théorie extraordinairement élégante, le Modèle Standard, décrit tous les résultats des expériences dans le domaine. Trente-sept particules élémentaires et quatre forces fondamentales : c est tout ce dont nous avons besoin pour expliquer la matière et l Univers ! Ce livre, destiné à un large public, raconte sans équations le long parcours qui a abouti au Modèle Standard. Ce parcours, parfois sinueux, a été entamé lorsque les Grecs anciens, et peut-être d autres avant eux, ont imaginé que la matière est composée de petites « billes ». Il faudra attendre plusieurs siècles pour qu on réalise que la matière, à l échelle micros...

  6. Pet ownership and physical health.

    Science.gov (United States)

    Matchock, Robert L

    2015-09-01

    Pet ownership and brief human-animal interactions can serve as a form of social support and convey a host of beneficial psychological and physiological health benefits. This article critically examines recent relevant literature on the pet-health connection. Cross-sectional studies indicate correlations between pet ownership and numerous aspects of positive health outcomes, including improvements on cardiovascular measures and decreases in loneliness. Quasi-experimental studies and better controlled experimental studies corroborate these associations and suggest that owning and/or interacting with a pet may be causally related to some positive health outcomes. The value of pet ownership and animal-assisted therapy (AAT), as a nonpharmacological treatment modality, augmentation to traditional treatment, and healthy preventive behavior (in the case of pet ownership), is starting to be realized. However, more investigations that employ randomized controlled trials with larger sample sizes and investigations that more closely examine the underlying mechanism of the pet-health effect, such as oxytocin, are needed.

  7. Towards robust deconvolution of low-dose perfusion CT: Sparse perfusion deconvolution using online dictionary learning

    Science.gov (United States)

    Fang, Ruogu; Chen, Tsuhan; Sanelli, Pina C.

    2014-01-01

    Computed tomography perfusion (CTP) is an important functional imaging modality in the evaluation of cerebrovascular diseases, particularly in acute stroke and vasospasm. However, the post-processed parametric maps of blood flow tend to be noisy, especially in low-dose CTP, due to the noisy contrast enhancement profile and the oscillatory nature of the results generated by the current computational methods. In this paper, we propose a robust sparse perfusion deconvolution method (SPD) to estimate cerebral blood flow in CTP performed at low radiation dose. We first build a dictionary from high-dose perfusion maps using online dictionary learning and then perform deconvolution-based hemodynamic parameters estimation on the low-dose CTP data. Our method is validated on clinical data of patients with normal and pathological CBF maps. The results show that we achieve superior performance than existing methods, and potentially improve the differentiation between normal and ischemic tissue in the brain. PMID:23542422

  8. Pulmonary artery perfusion versus no perfusion during cardiopulmonary bypass for open heart surgery in adults

    DEFF Research Database (Denmark)

    Buggeskov, Katrine B; Grønlykke, Lars; Risom, Emilie C

    2018-01-01

    BACKGROUND: Available evidence has been inconclusive on whether pulmonary artery perfusion during cardiopulmonary bypass (CPB) is associated with decreased or increased mortality, pulmonary events, and serious adverse events (SAEs) after open heart surgery. To our knowledge, no previous systematic...... handsearched retrieved study reports and scanned citations of included studies and relevant reviews to ensure that no relevant trials were missed. We searched for ongoing trials and unpublished trials in the World Health Organization International Clinical Trials Registry Platform (ICTRP) and at clinicaltrials......). We used GRADE principles to assess the quality of evidence. MAIN RESULTS: We included in this review four RCTs (210 participants) reporting relevant outcomes. Investigators randomly assigned participants to pulmonary artery perfusion with blood versus no perfusion during CPB. Only one trial included...

  9. Demonstration of decreased posterior cingulate perfusion in mild Alzheimer's disease by means of H215O positron emission tomography

    International Nuclear Information System (INIS)

    Ishii, Kazunari; Sasaki, Masahiro; Yamaji, Shigeru; Sakamoto, Setsu; Kitagaki, Hajime; Mori, Etsuro

    1997-01-01

    Although decreased posterior cingulate metabolism in Alzheimer's disease (AD) has been previously reported, there have been no reports on posterior cingulate perfusion. In this study we evaluated posterior cingulate perfusion as a relative value using statistical parametric maps (SPMs) and as an absolute value using conventional region of interest (ROI) settings. Twenty-eight subjects, including 14 patients with mild AD (mean age: 66.4±12.1 years) and 14 normal controls (65.9±7.3 years) were studied. Regional cerebral blood flow (CBF) was measured with H 2 15 O and positron emission tomography (PET). In the SPM analysis, the left posterior cingulate and left parietotemporal CBFs were significantly decreased in the patients with mild AD (P<0.001). At a lower statistical threshold (P<0.05), the right posterior cingulate and right parietotemporal CBFs were also significantly decreased in the AD patients. In the ROI studies, the left parietal and posterior cingulate CBFs in the patients with mild AD were significantly lower than those of the normal controls by analysis of variance and post-hoc Scheffe's test (P<0.001). We conclude that posterior cingulate perfusion is decreased in mild AD, reflecting the pathological changes and metabolic reduction in the posterior cingulate gyrus that have previously been reported to occur in mild AD. (orig.). With 1 fig., 2 tabs

  10. Hepatic arterial perfusion increases in the early stage of severe acute pancreatitis patients: Evaluation by perfusion computed tomography

    International Nuclear Information System (INIS)

    Koyasu, Sho; Isoda, Hiroyoshi; Tsuji, Yoshihisa; Yamamoto, Hiroshi; Matsueda, Kazuhiro; Watanabe, Yuji; Chiba, Tsutomu; Togashi, Kaori

    2012-01-01

    Purpose: Although hepatic perfusion abnormalities have been reported in patients with acute pancreatitis, hepatic perfusion with severe acute pancreatitis (SAP) has not been quantitatively evaluated in humans. Therefore, we investigated hepatic perfusion in patients with SAP using perfusion CT. Materials and methods: Hepatic perfusion CT was performed in 67 patients with SAP within 3 days after symptom onset. The patients were diagnosed as having SAP according to the Atlanta criteria. Fifteen cases were established as a control group. Perfusion CT was obtained for 54 s beginning with a bolus injection of 40 ml of contrast agent (600–630 mgI/kg) at a flow rate of 4 ml/s. Perfusion data were analyzed by the dual-input maximum slope method to obtain hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP). Finally, we compared HAP and HPP in SAP patients with those in the control group, respectively. Results: Average HAP was significantly higher in SAP patients than in the control group (75.1 ± 38.0 vs. 38.2 ± 9.0 ml/min/100 ml; p < 0.001). There was no significant difference in average HPP between SAP patients and the control group (206.7 ± 54.9 vs. 204.4 ± 38.5 ml/min/100 ml; p = 0.92). Conclusion: Using quantitative analysis on perfusion CT, we first demonstrated an increase of HAP in the right hepatic lobe in SAP patients.

  11. New developments in PET detector technology

    International Nuclear Information System (INIS)

    Niu Lingxin; Zhao Shujun; Zhang Bin; Liu Haojia

    2010-01-01

    The researches on PET detector are always active and innovative area. The research direction of PET detector includes improving performances of scintillator-based detectors, investigating new detectors suitable for multi-modality imaging (e.g. PET/CT and PET/MRI), meeting requirements of TOF and DOI technologies and boosting the development of the technologies. In this paper, new developments in PET detector technology about scintillation crystal, photodetector and semiconductor detector is introduced. (authors)

  12. Biologic targets identified from dynamic 18FDG-PET and implications for image-guided therapy

    International Nuclear Information System (INIS)

    Rusten, Espen; Malinen, Eirik; Roedal, Jan; Bruland, Oeyvind S.

    2013-01-01

    Purpose: The outcome of biologic image-guided radiotherapy depends on the definition of the biologic target. The purpose of the current work was to extract hyper perfused and hypermetabolic regions from dynamic positron emission tomography (D-PET) images, to dose escalate either region and to discuss implications of such image guided strategies. Methods: Eleven patients with soft tissue sarcomas were investigated with D-PET. The images were analyzed using a two-compartment model producing parametric maps of perfusion and metabolic rate. The two image series were segmented and exported to a treatment planning system, and biological target volumes BTV per and BTV met (perfusion and metabolism, respectively) were generated. Dice's similarity coefficient was used to compare the two biologic targets. Intensity-modulated radiation therapy (IMRT) plans were generated for a dose painting by contours regime, where planning target volume (PTV) was planned to 60 Gy and BTV to 70 Gy. Thus, two separate plans were created for each patient with dose escalation of either BTV per or BTV met . Results: BTV per was somewhat smaller than BTV met (209 ±170 cm 3 against 243 ±143 cm 3 , respectively; population-based mean and s.d.). Dice's coefficient depended on the applied margin, and was 0.72 ±0.10 for a margin of 10 mm. Boosting BTV per resulted in mean dose of 69 ±1.0 Gy to this region, while BTV met received 67 ±3.2 Gy. Boosting BTV met gave smaller dose differences between the respective non-boost DVHs (such as D 98 ). Conclusions: Dose escalation of one of the BTVs results in a partial dose escalation of the other BTV as well. If tumor aggressiveness is equally pronounced in hyper perfused and hypermetabolic regions, this should be taken into account in the treatment planning

  13. Developing a Benchmarking Process in Perfusion: A Report of the Perfusion Downunder Collaboration

    Science.gov (United States)

    Baker, Robert A.; Newland, Richard F.; Fenton, Carmel; McDonald, Michael; Willcox, Timothy W.; Merry, Alan F.

    2012-01-01

    Abstract: Improving and understanding clinical practice is an appropriate goal for the perfusion community. The Perfusion Downunder Collaboration has established a multi-center perfusion focused database aimed at achieving these goals through the development of quantitative quality indicators for clinical improvement through benchmarking. Data were collected using the Perfusion Downunder Collaboration database from procedures performed in eight Australian and New Zealand cardiac centers between March 2007 and February 2011. At the Perfusion Downunder Meeting in 2010, it was agreed by consensus, to report quality indicators (QI) for glucose level, arterial outlet temperature, and pCO2 management during cardiopulmonary bypass. The values chosen for each QI were: blood glucose ≥4 mmol/L and ≤10 mmol/L; arterial outlet temperature ≤37°C; and arterial blood gas pCO2 ≥ 35 and ≤45 mmHg. The QI data were used to derive benchmarks using the Achievable Benchmark of Care (ABC™) methodology to identify the incidence of QIs at the best performing centers. Five thousand four hundred and sixty-five procedures were evaluated to derive QI and benchmark data. The incidence of the blood glucose QI ranged from 37–96% of procedures, with a benchmark value of 90%. The arterial outlet temperature QI occurred in 16–98% of procedures with the benchmark of 94%; while the arterial pCO2 QI occurred in 21–91%, with the benchmark value of 80%. We have derived QIs and benchmark calculations for the management of several key aspects of cardiopulmonary bypass to provide a platform for improving the quality of perfusion practice. PMID:22730861

  14. Magnetic Resonance Imaging of Ventilation and Perfusion in the Lung

    Science.gov (United States)

    Prisk, Gordon Kim (Inventor); Hopkins, Susan Roberta (Inventor); Buxton, Richard Bruce (Inventor); Pereira De Sa, Rui Carlos (Inventor); Theilmann, Rebecca Jean (Inventor); Cronin, Matthew Vincent (Inventor)

    2017-01-01

    Methods, devices, and systems are disclosed for implementing a fully quantitative non-injectable contrast proton MRI technique to measure spatial ventilation-perfusion (VA/Q) matching and spatial distribution of ventilation and perfusion. In one aspect, a method using MRI to characterize ventilation and perfusion in a lung includes acquiring an MR image of the lung having MR data in a voxel and obtaining a breathing frequency parameter, determining a water density value, a specific ventilation value, and a perfusion value in at least one voxel of the MR image based on the MR data and using the water density value to determine an air content value, and determining a ventilation-perfusion ratio value that is the product of the specific ventilation value, the air content value, the inverse of the perfusion value, and the breathing frequency.

  15. Reversible ventilation and perfusion abnormalities in unilateral obstructed lung

    International Nuclear Information System (INIS)

    Ward, H.E.; Jones, R.L.; King, E.G.; Sproule, B.J.; Fortune, R.L.

    1982-01-01

    An intraluminal carcinoid tumor obstructing the left mainstem bronchus produced hypoxemia through alteration in ventilation/perfusion matching. Studies of regional lung function using 133-xenon (/sup 133/Xe) and a multiprobe computerized instrumentation system documented a reduction of perfusion to 22 percent and ventilation to 6 percent of the total. There was negligible washout of intravenously injected /sup 133/Xe from the left lung consistent with air trapping. Four days after left mainstem bronchial sleeve resection, perfusion, ventilation and washout of injected xenon had significantly improved and by four months postresection, all measurements were virtually normal, although complete restoration of perfusion in relation to ventilation was delayed. Regional lung function studied with a multiprobe system in this patient provided a clinical model for the study of ventilation and perfusion inter-relationships in large airway obstruction and demonstrated that a prolonged time may be required for return of perfusion to normal

  16. Kuwaiti oil fires—Particulate monitoring

    Science.gov (United States)

    Husain, Tahir; Amin, Mohamed B.

    The total suspended particulate (TSP) matters using a high-volume sampler and inhalable particulate matters using PM-10 samplers were collected at various locations in the Eastern Province of Saudi Arabia during and after the Kuwaiti oil fires. The collected samples were analysed for toxic metals and oil hydrocarbon concentrations including some carcinogenic organic compounds in addition to gravimetric analysis. The concentration values of particulate matters were determined on a daily basis at Dhahran. Abqaiq, Rahima, Tanajib and Jubail locations. The analyses of the filters show a high concentration of the inhalable particulate at various locations, especially when north or northwest winds were blowing. It was found that the inhalable particulate concentration exceeded the Meteorology and Environmental Protection Administration (MEPA) permissible limit of 340 μg m- 3 at most of these locations during May-October 1991. A trend between the total suspended particulate and inhalable particulate measured concurrently at the same locations was observed and a regression equation was developed to correlate PM-10 data with the total suspended particulate data.

  17. Air Quality Criteria for Particulate Matter.

    Science.gov (United States)

    National Air Pollution Control Administration (DHEW), Washington, DC.

    To assist states in developing air quality standards, this book offers a review of literature related to atmospheric particulates and the development of criteria for air quality. It not only summarizes the current scientific knowledge of particulate air pollution, but points up the major deficiencies in that knowledge and the need for further…

  18. Externality costs by emission. E. Particulates

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Fossil-fuel-fired electricity generating systems, particularly coal and oil-fired facilities, are significant emitters of particulate matter. The major components of particulate emissions from a power plant include ash, which is made up of heavy metals, radioactive isotopes and hydrocarbons, and sulfates (SO 4 ) and nitrates (NO 3 ), which are formed by reaction of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ) in the atmosphere. The smallest ash particulates (including sulfates and nitrates) cause human respiratory effects and impaired visibility. Other effects may include materials damage due to soiling and possibly corrosion, damage to domestic and wild flora through deposition of particulates on foliage, and possible health effects on domestic animals and wild fauna. Several studies focus on the direct effects of high ambient levels of small particulates. This chapter reviews the available literature on the effects of particulate emissions on humans and their environment, and attempts to assign a cost figure to the environmental effects and human health impairments associated with particulate matter emissions. Specifically, this report focuses on the effects of particulates related to human health, visibility, flora, fauna and materials

  19. Particulate carbohydrates in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Nandakumar, K.; Venkat, K.

    Particulate matter collected from 77 water samples over a 3000 m water column was analyzed for particulate carbohydrates (PCHO). PCHO in the surface waters ranged from 43 to 143 mu g.l-1, and below 250 m it was 16.PCHO showed large variations at all...

  20. Computed tomography myocardial perfusion vs {sup 15}O-water positron emission tomography and fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Michelle C.; Dweck, Marc R.; Golay, Saroj K. [University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Edinburgh (United Kingdom); Mirsadraee, Saeed; Weir, Nicholas W.; Fletcher, Alison; Lucatelli, Christophe; Reid, John H. [University of Edinburgh, Clinical Research Imaging Centre, Edinburgh (United Kingdom); MacGillivray, Tom; Van Beek, Edwin J.R.; Newby, David E. [University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Edinburgh (United Kingdom); University of Edinburgh, Clinical Research Imaging Centre, Edinburgh (United Kingdom); Cruden, Nicholas L.; Henriksen, Peter A.; Uren, Neal [Edinburgh Heart Centre, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom); McKillop, Graham; Patel, Dilip [Department of Radiology, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom); Lima, Joao A.C. [Johns Hopkins Hospital, Departments of Medicine and Radiology, Baltimore, MD (United States)

    2017-03-15

    Computed tomography (CT) can perform comprehensive cardiac imaging. We compared CT coronary angiography (CTCA) and CT myocardial perfusion (CTP) with {sup 15}O-water positron emission tomography (PET) and invasive coronary angiography (ICA) with fractional flow reserve (FFR). 51 patients (63 (61-65) years, 80 % male) with known/suspected coronary artery disease (CAD) underwent 320-multidetector CTCA followed by ''snapshot'' adenosine stress CTP. Of these 22 underwent PET and 47 ICA/FFR. Obstructive CAD was defined as CTCA stenosis >50 % and CTP hypoperfusion, ICA stenosis >70 % or FFR <0.80. PET hyperaemic myocardial blood flow (MBF) was lower in obstructive than non-obstructive territories defined by ICA/FFR (1.76 (1.32-2.20) vs 3.11 (2.44-3.79) mL/(g/min), P < 0.001) and CTCA/CTP (1.76 (1.32-2.20) vs 3.12 (2.44-3.79) mL/(g/min), P < 0.001). Baseline and hyperaemic CT attenuation density was lower in obstructive than non-obstructive territories (73 (71-76) vs 86 (84-88) HU, P < 0.001 and 101 (96-106) vs 111 (107-114) HU, P 0.001). PET hyperaemic MBF corrected for rate pressure product correlated with CT attenuation density (r = 0.579, P < 0.001). There was excellent per-patient sensitivity (96 %), specificity (85 %), negative predictive value (90 %) and positive predictive value (94 %) for CTCA/CTP vs ICA/FFR. CT myocardial attenuation density correlates with {sup 15}O-water PET MBF. CTCA and CTP can accurately identify obstructive CAD. (orig.)

  1. PET and PET/CT in tumour of undetermined origin

    International Nuclear Information System (INIS)

    Garcia O, J.R.

    2007-01-01

    In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. After standard evaluation. Before advanced protocol. 5. PET/CT study increases the % of primary detection, although in a non significant way vs. PET. 6. They are required more studies to value their utility to a more objective manner. (Author)

  2. Quantification of myocardial blood flow using dynamic 320-row multi-detector CT as compared with 15O-H2O PET

    International Nuclear Information System (INIS)

    Kikuchi, Yasuka; Oyama-Manabe, Noriko; Kudo, Kohsuke; Naya, Masanao; Manabe, Osamu; Tomiyama, Yuuki; Tamaki, Nagara; Sasaki, Tsukasa; Katoh, Chietsugu; Shirato, Hiroki

    2014-01-01

    This study introduces a method to calculate myocardium blood flow (MBF) and coronary flow reserve (CFR) using the relatively low-dose dynamic 320-row multi-detector computed tomography (MDCT), validates the method against 15 O-H 2 O positron-emission tomography (PET) and assesses the CFRs of coronary artery disease (CAD) patients. Thirty-two subjects underwent both dynamic CT perfusion (CTP) and PET perfusion imaging at rest and during pharmacological stress. In 12 normal subjects (pilot group), the calculation method for MBF and CFR was established. In the other 13 normal subjects (validation group), MBF and CFR obtained by dynamic CTP and PET were compared. Finally, the CFRs obtained by dynamic CTP and PET were compared between the validation group and CAD patients (n = 7). Correlation between MBF of MDCT and PET was strong (r = 0.95, P CT in the CAD group (2.3 ± 0.8) was significantly lower than that in the validation group (5.2 ± 1.8) (P = 0.0011). We established a method for measuring MBF and CFR with the relatively low-dose dynamic MDCT. Lower CFR was well demonstrated in CAD patients by dynamic CTP. (orig.)

  3. Whole-brain dynamic CT angiography and perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Orrison, W.W. [CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Department of Medical Education, University of Nevada School of Medicine, Reno, NV (United States); Snyder, K.V.; Hopkins, L.N. [Department of Neurosurgery, Millard Fillmore Gates Circle Hospital, Buffalo, NY (United States); Roach, C.J. [School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); Ringdahl, E.N. [Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV (United States); Nazir, R. [Shifa International Hospital, Islamabad (Pakistan); Hanson, E.H., E-mail: eric.hanson@amigenics.co [College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States)

    2011-06-15

    The availability of whole brain computed tomography (CT) perfusion has expanded the opportunities for analysing the haemodynamic parameters associated with varied neurological conditions. Examples demonstrating the clinical utility of whole-brain CT perfusion imaging in selected acute and chronic ischaemic arterial neurovascular conditions are presented. Whole-brain CT perfusion enables the detection and focused haemodynamic analyses of acute and chronic arterial conditions in the central nervous system without the limitation of partial anatomical coverage of the brain.

  4. Simultaneous Multiagent Hyperpolarized 13C Perfusion Imaging

    DEFF Research Database (Denmark)

    von Morze, Cornelius; Bok, Robert A.; Reed, Galen D.

    2014-01-01

    in simulations. "Tripolarized" perfusion MRI methods were applied to initial preclinical studies with differential conditions of vascular permeability, in normal mouse tissues and advanced transgenic mouse prostate tumors. Results: Dynamic imaging revealed clear differences among the individual tracer...... distributions. Computed permeability maps demonstrated differential permeability of brain tissue among the tracers, and tumor perfusion and permeability were both elevated over values expected for normal tissues. Conclusion: Tripolarized perfusion MRI provides new molecular imaging measures for specifically...

  5. PET/TAC in Oncology; PET/TAC en Oncologia

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez V, A M [Especialista en Medicina Nuclear, Profa. Depto. Radiologia de la Facultad de Medicina, Universidad Complutense de Madrid, Madrid (Spain)

    2007-07-01

    From this presentation of PET-TAC in oncology the following advantages on the conventional PET are obtained: 1. More short study and stadium in one session. 2. It adds the information of both techniques. 3. Better localization of leisure: affected organ, stadium change (neck, mediastinum, abdomen). 4. Reduction of false positive (muscle, brown fat, atelectasis, pneumonias, intestine, urinary vials, etc.). 5. Reduction of negative false. 6. Reduction of not conclusive. 7. More understandable for other specialists. 8. Biopsies guide. 9. Planning radiotherapy.

  6. Advanced Fine Particulate Characterization Methods

    Energy Technology Data Exchange (ETDEWEB)

    Steven Benson; Lingbu Kong; Alexander Azenkeng; Jason Laumb; Robert Jensen; Edwin Olson; Jill MacKenzie; A.M. Rokanuzzaman

    2007-01-31

    The characterization and control of emissions from combustion sources are of significant importance in improving local and regional air quality. Such emissions include fine particulate matter, organic carbon compounds, and NO{sub x} and SO{sub 2} gases, along with mercury and other toxic metals. This project involved four activities including Further Development of Analytical Techniques for PM{sub 10} and PM{sub 2.5} Characterization and Source Apportionment and Management, Organic Carbonaceous Particulate and Metal Speciation for Source Apportionment Studies, Quantum Modeling, and High-Potassium Carbon Production with Biomass-Coal Blending. The key accomplishments included the development of improved automated methods to characterize the inorganic and organic components particulate matter. The methods involved the use of scanning electron microscopy and x-ray microanalysis for the inorganic fraction and a combination of extractive methods combined with near-edge x-ray absorption fine structure to characterize the organic fraction. These methods have direction application for source apportionment studies of PM because they provide detailed inorganic analysis along with total organic and elemental carbon (OC/EC) quantification. Quantum modeling using density functional theory (DFT) calculations was used to further elucidate a recently developed mechanistic model for mercury speciation in coal combustion systems and interactions on activated carbon. Reaction energies, enthalpies, free energies and binding energies of Hg species to the prototype molecules were derived from the data obtained in these calculations. Bimolecular rate constants for the various elementary steps in the mechanism have been estimated using the hard-sphere collision theory approximation, and the results seem to indicate that extremely fast kinetics could be involved in these surface reactions. Activated carbon was produced from a blend of lignite coal from the Center Mine in North Dakota and

  7. The continual innovation of commercial PET/CT solutions in nuclear cardiology: Siemens Healthineers.

    Science.gov (United States)

    Bendriem, Bernard; Reed, Jessie; McCullough, Kathryn; Khan, Mohammad Raza; Smith, Anne M; Thomas, Damita; Long, Misty

    2018-04-10

    Cardiac PET/CT is an evolving, non-invasive imaging modality that impacts patient management in many clinical scenarios. Beyond offering the capability to assess myocardial perfusion, inflammatory cardiac pathologies, and myocardial viability, cardiac PET/CT also allows for the non-invasive quantitative assessment of myocardial blood flow (MBF) and myocardial flow reserve (MFR). Recognizing the need for an enhanced comprehension of coronary physiology, Siemens Healthineers implemented a sophisticated solution for the calculation of MBF and MFR in 2009. As a result, each aspect of their innovative scanner and image-processing technology seamlessly integrates into an efficient, easy-to-use workflow for everyday clinical use that maximizes the number of patients who potentially benefit from this imaging modality.

  8. Preclinical evaluation and quantification of [(18)F]MK-9470 as a radioligand for PET imaging of the type 1 cannabinoid receptor in rat brain

    OpenAIRE

    Casteels, Cindy; Koole, Michel; Celen, Sofie; Bormans, Guy; Van Laere, Koen

    2012-01-01

    PURPOSE: [(18)F]MK-9470 is an inverse agonist for the type 1 cannabinoid (CB1) receptor allowing its use in PET imaging. We characterized the kinetics of [(18)F]MK-9470 and evaluated its ability to quantify CB1 receptor availability in the rat brain. METHODS: Dynamic small-animal PET scans with [(18)F]MK-9470 were performed in Wistar rats on a FOCUS-220 system for up to 10 h. Both plasma and perfused brain homogenates were analysed using HPLC to quantify radiometabolites. Displacement and blo...

  9. Effect of Defocused CO2 Laser on Equine Tissue Perfusion

    Directory of Open Access Journals (Sweden)

    Bergh A

    2006-03-01

    Full Text Available Treatment with defocused CO2 laser can have a therapeutic effect on equine injuries, but the mechanisms involved are unclear. A recent study has shown that laser causes an increase in equine superficial tissue temperature, which may result in an increase in blood perfusion and a stimulating effect on tissue regeneration. However, no studies have described the effects on equine tissue perfusion. The aim of the present study was to investigate the effect of defocused CO2 laser on blood perfusion and to correlate it with temperature in skin and underlying muscle in anaesthetized horses. Differences between clipped and unclipped haircoat were also assessed. Eight horses and two controls received CO2 laser treatment (91 J/cm2 in a randomised order, on a clipped and unclipped area of the hamstring muscles, respectively. The significant increase in clipped skin perfusion and temperature was on average 146.3 ± 33.4 perfusion units (334% and 5.5 ± 1.5°C, respectively. The significant increase in perfusion and temperature in unclipped skin were 80.6 ± 20.4 perfusion units (264% and 4.8 ± 1.4°C. No significant changes were seen in muscle perfusion or temperature. In conclusion, treatment with defocused CO2 laser causes a significant increase in skin perfusion, which is correlated to an increase in skin temperature.

  10. Perfusion lung scanning: differentiation of primary from thromboembolic pulmonary hypertension

    International Nuclear Information System (INIS)

    Lisbona, R.; Kreisman, H.; Novales-Diaz, J.; Derbekyan, V.

    1985-01-01

    Of eight patients with pulmonary arterial hypertension, final diagnosis established by autopsy or angiography, four had primary hypertension and four hypertension from thromboembolism. The perfusion lung scan was distinctly different in the two groups. The lung scan in primary pulmonary hypertension was associated with nonsegmental, patchy defects of perfusion, while in thromboembolic hypertensives it was characterized by segmental and/or lobar defects of perfusion with or without subsegmental defects. The perfusion lung scan is a valuable, noninvasive study in the evaluation of the patient with pulmonary hypertension of undetermined cause and in the exclusion of occult large-vessel pulmonary thromboembolism

  11. Measurement of extracellular volume and transit time heterogeneity using contrast-enhanced myocardial perfusion MRI in patients after acute myocardial infarction.

    Science.gov (United States)

    Kunze, Karl P; Rischpler, Christoph; Hayes, Carmel; Ibrahim, Tareq; Laugwitz, Karl-Ludwig; Haase, Axel; Schwaiger, Markus; Nekolla, Stephan G

    2017-06-01

    To assess the ability of dynamic contrast-enhanced myocardial perfusion MRI to measure extracellular volume (ECV) and to investigate the possibility of estimating capillary transit time heterogeneity (CTH) in patients after myocardial infarction and successful revascularization. Twenty-four perfusion data sets were acquired on a 3 Tesla positron emission tomography (PET)/MRI scanner. Three perfusion models of different complexity were implemented in a hierarchical fashion with an Akaike information criterion being used to determine the number of fit parameters supported by the data. Results were compared sector-wise to ECV from an equilibrium T 1 mapping method (modified look-locker inversion recovery (MOLLI)). ECV derived from the perfusion analysis correlated well with equilibrium measurements (R² = 0.76). Estimation of CTH was supported in 16% of sectors (mostly remote). Inclusion of a nonzero CTH parameter usually led to lower estimates of first-pass extraction and slightly higher estimates of blood volume and flow. Estimation of the capillary permeability-surface area product was feasible in 81% of sectors. Transit time heterogeneity has a measurable effect on the kinetic analysis of myocardial perfusion MRI data, and Gd-DTPA extravasation in the myocardium is usually not flow-limited in infarct-related pathology. Measurement of myocardial ECV using perfusion imaging could provide a scan-time efficient alternative to methods based on T 1 mapping. Magn Reson Med 77:2320-2330, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  12. Low dose dynamic CT myocardial perfusion imaging using a statistical iterative reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Yinghua [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Chen, Guang-Hong [Department of Medical Physics and Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Hacker, Timothy A.; Raval, Amish N. [Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Van Lysel, Michael S.; Speidel, Michael A., E-mail: speidel@wisc.edu [Department of Medical Physics and Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2014-07-15

    Purpose: Dynamic CT myocardial perfusion imaging has the potential to provide both functional and anatomical information regarding coronary artery stenosis. However, radiation dose can be potentially high due to repeated scanning of the same region. The purpose of this study is to investigate the use of statistical iterative reconstruction to improve parametric maps of myocardial perfusion derived from a low tube current dynamic CT acquisition. Methods: Four pigs underwent high (500 mA) and low (25 mA) dose dynamic CT myocardial perfusion scans with and without coronary occlusion. To delineate the affected myocardial territory, an N-13 ammonia PET perfusion scan was performed for each animal in each occlusion state. Filtered backprojection (FBP) reconstruction was first applied to all CT data sets. Then, a statistical iterative reconstruction (SIR) method was applied to data sets acquired at low dose. Image voxel noise was matched between the low dose SIR and high dose FBP reconstructions. CT perfusion maps were compared among the low dose FBP, low dose SIR and high dose FBP reconstructions. Numerical simulations of a dynamic CT scan at high and low dose (20:1 ratio) were performed to quantitatively evaluate SIR and FBP performance in terms of flow map accuracy, precision, dose efficiency, and spatial resolution. Results: Forin vivo studies, the 500 mA FBP maps gave −88.4%, −96.0%, −76.7%, and −65.8% flow change in the occluded anterior region compared to the open-coronary scans (four animals). The percent changes in the 25 mA SIR maps were in good agreement, measuring −94.7%, −81.6%, −84.0%, and −72.2%. The 25 mA FBP maps gave unreliable flow measurements due to streaks caused by photon starvation (percent changes of +137.4%, +71.0%, −11.8%, and −3.5%). Agreement between 25 mA SIR and 500 mA FBP global flow was −9.7%, 8.8%, −3.1%, and 26.4%. The average variability of flow measurements in a nonoccluded region was 16.3%, 24.1%, and 937

  13. Low dose dynamic CT myocardial perfusion imaging using a statistical iterative reconstruction method

    International Nuclear Information System (INIS)

    Tao, Yinghua; Chen, Guang-Hong; Hacker, Timothy A.; Raval, Amish N.; Van Lysel, Michael S.; Speidel, Michael A.

    2014-01-01

    Purpose: Dynamic CT myocardial perfusion imaging has the potential to provide both functional and anatomical information regarding coronary artery stenosis. However, radiation dose can be potentially high due to repeated scanning of the same region. The purpose of this study is to investigate the use of statistical iterative reconstruction to improve parametric maps of myocardial perfusion derived from a low tube current dynamic CT acquisition. Methods: Four pigs underwent high (500 mA) and low (25 mA) dose dynamic CT myocardial perfusion scans with and without coronary occlusion. To delineate the affected myocardial territory, an N-13 ammonia PET perfusion scan was performed for each animal in each occlusion state. Filtered backprojection (FBP) reconstruction was first applied to all CT data sets. Then, a statistical iterative reconstruction (SIR) method was applied to data sets acquired at low dose. Image voxel noise was matched between the low dose SIR and high dose FBP reconstructions. CT perfusion maps were compared among the low dose FBP, low dose SIR and high dose FBP reconstructions. Numerical simulations of a dynamic CT scan at high and low dose (20:1 ratio) were performed to quantitatively evaluate SIR and FBP performance in terms of flow map accuracy, precision, dose efficiency, and spatial resolution. Results: Forin vivo studies, the 500 mA FBP maps gave −88.4%, −96.0%, −76.7%, and −65.8% flow change in the occluded anterior region compared to the open-coronary scans (four animals). The percent changes in the 25 mA SIR maps were in good agreement, measuring −94.7%, −81.6%, −84.0%, and −72.2%. The 25 mA FBP maps gave unreliable flow measurements due to streaks caused by photon starvation (percent changes of +137.4%, +71.0%, −11.8%, and −3.5%). Agreement between 25 mA SIR and 500 mA FBP global flow was −9.7%, 8.8%, −3.1%, and 26.4%. The average variability of flow measurements in a nonoccluded region was 16.3%, 24.1%, and 937

  14. Particulate filtration in nuclear facilities

    International Nuclear Information System (INIS)

    1991-01-01

    The removal of particulate radioactive material from exhaust air or gases is an essential feature of virtually all nuclear facilities. Recent IAEA publications have covered the broad designs of off-gas and air cleaning systems for the range of nuclear power plants and other facilities. This report is a complementary guidebook that examines in detail the latest developments in the design, operation, maintenance and testing of fibrous air filters. The original draft of the report was prepared by three consultants, M.W. First, of the School of Public Health, Harvard University, United States of America, K.S. Robinson, from the UKAEA Harwell Laboratory, United Kingdom, and H.G. Dillmann, of the Kernforschungzentrum, Karlsruhe, Germany. The Technical Committee Meeting (TCM), at which the report was reviewed and much additional information contributed, was attended by 11 experts and was held in Vienna, from 30 May to 3 June 1988. 64 refs, 41 figs, 10 tabs

  15. Radiant zone heated particulate filter

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  16. PET and PET/CT in tumour of undetermined origin; PET y PET/CT en tumor de origen indeterminado

    Energy Technology Data Exchange (ETDEWEB)

    Garcia O, J R [Nuclear Medicine and Molecular Imaging, PET/CT, Centro Medico ABC, Mexico D.F. (Mexico)

    2007-07-01

    In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. A