WorldWideScience

Sample records for animal pet imaging

  1. Technology challenges in small animal PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lecomte, Roger E-mail: roger.lecomte@usherbrooke.ca

    2004-07-11

    Positron Emission Tomography (PET) is a non-invasive nuclear imaging modality allowing biochemical processes to be investigated in vivo with sensitivity in the picomolar range. For this reason, PET has the potential to play a major role in the emerging field of molecular imaging by enabling the study of molecular pathways and genetic processes in living animals non-invasively. The challenge is to obtain a spatial resolution that is appropriate for rat and mouse imaging, the preferred animal models for research in biology, while achieving a sensitivity adequate for real-time measurement of rapid dynamic processes in vivo without violating tracer kinetic principles. An overview of the current state of development of dedicated small animal PET scanners is given, and selected applications are reported and discussed with respect to performance and significance to research in biology.

  2. Molecular Imaging with Small Animal PET/CT

    DEFF Research Database (Denmark)

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

    2011-01-01

    Small animal positron emission tomography (PET) and computer tomography (CT) is an emerging field in pre-clinical imaging. High quality, state-of-the-art instruments are required for full optimization of the translational value of the small animal studies with PET and CT. However, with this achie...... small animal PET/CT for studies of muscle and tendon in exercise models. © 2011 Bentham Science Publishers Ltd.......Small animal positron emission tomography (PET) and computer tomography (CT) is an emerging field in pre-clinical imaging. High quality, state-of-the-art instruments are required for full optimization of the translational value of the small animal studies with PET and CT. However, with this...... this field of small animal molecular imaging with special emphasis on the targets for tissue characterization in tumor biology such as hypoxia, proliferation and cancer specific over-expression of receptors. The added value of applying CT imaging for anatomical localization and tumor volume...

  3. Monte Carlo simulations in small animal PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Susana [Universidade de Lisboa, Faculdade de Ciencias, Instituto de Biofisica e Engenharia Biomedica, Lisbon (Portugal)], E-mail: susana.silva@fc.ul.pt; Jan, Sebastien [Service Hospitalier Frederic Joliot, CEA/DSV/DRM, Orsay (France); Almeida, Pedro [Universidade de Lisboa, Faculdade de Ciencias, Instituto de Biofisica e Engenharia Biomedica, Lisbon (Portugal)

    2007-10-01

    This work is based on the use of an implemented Positron Emission Tomography (PET) simulation system dedicated for small animal PET imaging. Geant4 Application for Tomographic Emission (GATE), a Monte Carlo simulation platform based on the Geant4 libraries, is well suited for modeling the microPET FOCUS system and to implement realistic phantoms, such as the MOBY phantom, and data maps from real examinations. The use of a microPET FOCUS simulation model with GATE has been validated for spatial resolution, counting rates performances, imaging contrast recovery and quantitative analysis. Results from realistic studies of the mouse body using {sup -}F and [{sup 18}F]FDG imaging protocols are presented. These simulations include the injection of realistic doses into the animal and realistic time framing. The results have shown that it is possible to simulate small animal PET acquisitions under realistic conditions, and are expected to be useful to improve the quantitative analysis in PET mouse body studies.

  4. Monte Carlo simulations in small animal PET imaging

    International Nuclear Information System (INIS)

    This work is based on the use of an implemented Positron Emission Tomography (PET) simulation system dedicated for small animal PET imaging. Geant4 Application for Tomographic Emission (GATE), a Monte Carlo simulation platform based on the Geant4 libraries, is well suited for modeling the microPET FOCUS system and to implement realistic phantoms, such as the MOBY phantom, and data maps from real examinations. The use of a microPET FOCUS simulation model with GATE has been validated for spatial resolution, counting rates performances, imaging contrast recovery and quantitative analysis. Results from realistic studies of the mouse body using -F and [18F]FDG imaging protocols are presented. These simulations include the injection of realistic doses into the animal and realistic time framing. The results have shown that it is possible to simulate small animal PET acquisitions under realistic conditions, and are expected to be useful to improve the quantitative analysis in PET mouse body studies

  5. Importance of Attenuation Correction (AC for Small Animal PET Imaging

    Directory of Open Access Journals (Sweden)

    Henrik H. El Ali

    2012-10-01

    Full Text Available The purpose of this study was to investigate whether a correction for annihilation photon attenuation in small objects such as mice is necessary. The attenuation recovery for specific organs and subcutaneous tumors was investigated. A comparison between different attenuation correction methods was performed. Methods: Ten NMRI nude mice with subcutaneous implantation of human breast cancer cells (MCF-7 were scanned consecutively in small animal PET and CT scanners (MicroPETTM Focus 120 and ImTek’s MicroCATTM II. CT-based AC, PET-based AC and uniform AC methods were compared. Results: The activity concentration in the same organ with and without AC revealed an overall attenuation recovery of 9–21% for MAP reconstructed images, i.e., SUV without AC could underestimate the true activity at this level. For subcutaneous tumors, the attenuation was 13 ± 4% (9–17%, for kidneys 20 ± 1% (19–21%, and for bladder 18 ± 3% (15–21%. The FBP reconstructed images showed almost the same attenuation levels as the MAP reconstructed images for all organs. Conclusions: The annihilation photons are suffering attenuation even in small subjects. Both PET-based and CT-based are adequate as AC methods. The amplitude of the AC recovery could be overestimated using the uniform map. Therefore, application of a global attenuation factor on PET data might not be accurate for attenuation correction.

  6. Small Animal [{sup 18}F]FDG PET Imaging for Tumor Model Study

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Sang Keun; Kim, Kyeong Min; Cheon, Gi Jeong [Radiological and Medical Sciences Research Institute, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2008-02-15

    PET allows non-invasive, quantitative and repetitive imaging of biological function in living animals. Small animal PET imaging with [{sup 18}F]FDG has been successfully applied to investigation of metabolism, receptor, ligand interactions, gene expression, adoptive cell therapy and somatic gene therapy. Experimental condition of animal handling impacts on the biodistribution of [{sup 18}F]FDG in small animal study. The small animal PET and CT images were registered using the hardware fiducial markers and small animal contour point. Tumor imaging in small animal with small animal [{sup 18}F]FDG PET should be considered fasting, warming, and isoflurane anesthesia level. Registered imaging with small animal PET and CT image could be useful for the detection of tumor. Small animal experimental condition of animal handling and registration method will be of most importance for small lesion detection of metastases tumor model.

  7. Performance Evaluation of microPET: A High-Resolution Lutetium Oxyorthosilicate PET Scanner for Animal Imaging

    OpenAIRE

    Chatziioannou, Arion F.; Cherry, Simon R.; Shao, Yiping; Silverman, Robert W.; Meadors, Ken; Farquhar, Thomas H.; Pedarsani, Marjan; Phelps, Michael E.

    1999-01-01

    A new dedicated PET scanner, microPET, was designed and developed at the University of California, Los Angeles, for imaging small laboratory animals. The goal was to provide a compact system with superior spatial resolution at a fraction of the cost of a clinical PET scanner.

  8. Optimising rigid motion compensation for small animal brain PET imaging

    Science.gov (United States)

    Spangler-Bickell, Matthew G.; Zhou, Lin; Kyme, Andre Z.; De Laat, Bart; Fulton, Roger R.; Nuyts, Johan

    2016-10-01

    Motion compensation (MC) in PET brain imaging of awake small animals is attracting increased attention in preclinical studies since it avoids the confounding effects of anaesthesia and enables behavioural tests during the scan. A popular MC technique is to use multiple external cameras to track the motion of the animal’s head, which is assumed to be represented by the motion of a marker attached to its forehead. In this study we have explored several methods to improve the experimental setup and the reconstruction procedures of this method: optimising the camera-marker separation; improving the temporal synchronisation between the motion tracker measurements and the list-mode stream; post-acquisition smoothing and interpolation of the motion data; and list-mode reconstruction with appropriately selected subsets. These techniques have been tested and verified on measurements of a moving resolution phantom and brain scans of an awake rat. The proposed techniques improved the reconstructed spatial resolution of the phantom by 27% and of the rat brain by 14%. We suggest a set of optimal parameter values to use for awake animal PET studies and discuss the relative significance of each parameter choice.

  9. Multimodal imaging of orthotopic hepatocellular carcinoma using small animal PET, bioluminescence and contrast enhanced CT imaging

    International Nuclear Information System (INIS)

    Molecular imaging with small-animal PET and bioluminescence imaging has been used as an important tool in cancer research. One of the disadvantages of these imaging modalities is the lack of anatomic information. To obtain fusion images with both molecular and anatomical information, small-animal PET and bioluminescence images fused with contrast enhance CT image in orthotopic hepatocellular carcinoma (HCC) model. We retrovially transfected dual gene (HSV1-tk and firefly luciferase) to morris hepatoma cells. The expression of HSV1-tk and luciferase was checked by optical imager and in vitro radiolabeled FIAU uptake, respectively and also checked by RT-PCR analysis. MCA-TL cells (5X105/ 0.05 ml) mixed with matrigel (1: 10) injected into left lobe of liver in nude mice. 124I-FIAU-PET, bioluminescence and contrast enhanced CT images were obtained in the orthotopic HCC model and digital whole body autoradiography (DWBA) was performed. Small animal PET image was obtained at 2 h post injection of 124I-FIAU and contrast enhanced CT image was obtained at 3 h post injection of Fenestra LC (0.3 ml). MCA-TL cells showed more specific 124I-FIAU uptake and higher luminescent activity than parental cells. The orthotopic HCC was detected by 124I-FIAU PET, contrast enhanced CT, and BLI and confirmed by DWBA. Registered image in orthotopic HCC t models showed a good correlation of images from both PET and CT. Contrast enhanced CT image delineated margin of HCC. Multimodal imaging with 124I-FIAU PET, bioluminescence and contrast enhanced CT allows a precise and improved detection of tumor in orthotopic hepatocellular carcinoma model. Multimodal imaging is potentially useful for monitoring progression of hepatic metastasis and for the evaluation of cancer treatments

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-04-11

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

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

    International Nuclear Information System (INIS)

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

  12. The motivations and methodology for high-throughput PET imaging of small animals in cancer research

    OpenAIRE

    Aide, Nicolas; Visser, Eric P.; Lheureux, Stéphanie; Heutte, Natacha; Szanda, Istvan; Hicks, Rodney J.

    2012-01-01

    Over the last decade, small-animal PET imaging has become a vital platform technology in cancer research. With the development of molecularly targeted therapies and drug combinations requiring evaluation of different schedules, the number of animals to be imaged within a PET experiment has increased. This paper describes experimental design requirements to reach statistical significance, based on the expected change in tracer uptake in treated animals as compared to the control group, the num...

  13. Evaluation of the respiratory motion effect in small animal PET images with GATE Monte Carlo simulations

    OpenAIRE

    Branco, Susana; Almeida, Pedro; Jan, Sébastien

    2011-01-01

    The rapid growth in genetics and molecular biology combined with the development of techniques for genetically engineering small animals has led to increased interest in in vivo small animal imaging. Small animal imaging has been applied frequently to the imaging of small animals (mice and rats), which are ubiquitous in modeling human diseases and testing treatments. The use of PET in small animals allows the use of subjects as their own control, reducing the interanimal variability....

  14. The motivations and methodology for high-throughput PET imaging of small animals in cancer research

    International Nuclear Information System (INIS)

    Over the last decade, small-animal PET imaging has become a vital platform technology in cancer research. With the development of molecularly targeted therapies and drug combinations requiring evaluation of different schedules, the number of animals to be imaged within a PET experiment has increased. This paper describes experimental design requirements to reach statistical significance, based on the expected change in tracer uptake in treated animals as compared to the control group, the number of groups that will be imaged, and the expected intra-animal variability for a given tracer. We also review how high-throughput studies can be performed in dedicated small-animal PET, high-resolution clinical PET systems and planar positron imaging systems by imaging more than one animal simultaneously. Customized beds designed to image more than one animal in large-bore small-animal PET scanners are described. Physics issues related to the presence of several rodents within the field of view (i.e. deterioration of spatial resolution and sensitivity as the radial and the axial offsets increase, respectively, as well as a larger effect of attenuation and the number of scatter events), which can be assessed by using the NEMA NU 4 image quality phantom, are detailed. (orig.)

  15. The motivations and methodology for high-throughput PET imaging of small animals in cancer research

    Energy Technology Data Exchange (ETDEWEB)

    Aide, Nicolas [Francois Baclesse Cancer Centre, Nuclear Medicine Department, Caen Cedex (France); Caen University, BioTICLA team, EA 4656, IFR 146, Caen (France); Visser, Eric P. [Radboud University Nijmegen Medical Center, Nuclear Medicine Department, Nijmegen (Netherlands); Lheureux, Stephanie [Caen University, BioTICLA team, EA 4656, IFR 146, Caen (France); Francois Baclesse Cancer Centre, Clinical Research Unit, Caen (France); Heutte, Natacha [Francois Baclesse Cancer Centre, Clinical Research Unit, Caen (France); Szanda, Istvan [King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Hicks, Rodney J. [Peter MacCallum Cancer Centre, Centre for Molecular Imaging, East Melbourne (Australia)

    2012-09-15

    Over the last decade, small-animal PET imaging has become a vital platform technology in cancer research. With the development of molecularly targeted therapies and drug combinations requiring evaluation of different schedules, the number of animals to be imaged within a PET experiment has increased. This paper describes experimental design requirements to reach statistical significance, based on the expected change in tracer uptake in treated animals as compared to the control group, the number of groups that will be imaged, and the expected intra-animal variability for a given tracer. We also review how high-throughput studies can be performed in dedicated small-animal PET, high-resolution clinical PET systems and planar positron imaging systems by imaging more than one animal simultaneously. Customized beds designed to image more than one animal in large-bore small-animal PET scanners are described. Physics issues related to the presence of several rodents within the field of view (i.e. deterioration of spatial resolution and sensitivity as the radial and the axial offsets increase, respectively, as well as a larger effect of attenuation and the number of scatter events), which can be assessed by using the NEMA NU 4 image quality phantom, are detailed. (orig.)

  16. Scatter Characterization and Correction for Simultaneous Multiple Small-Animal PET Imaging

    NARCIS (Netherlands)

    Prasad, Rameshwar; Zaidi, Habib

    2014-01-01

    The rapid growth and usage of small-animal positron emission tomography (PET) in molecular imaging research has led to increased demand on PET scanner's time. One potential solution to increase throughput is to scan multiple rodents simultaneously. However, this is achieved at the expense of deterio

  17. A combined micro-PET/CT scanner for small animal imaging

    International Nuclear Information System (INIS)

    A micro-PET/CT system was developed by combination of an in-house micro-CT and a microPET[reg] R4 scanner. The cone-beam micro-CT consists of a rotational gantry that fits an X-ray tube, a CCD-based X-ray detector, and motor-driven linear stages. The gantry was designed to be coaxial with the scanner of microPET'' (registered) R4. It can be moved for the convenience of mounting the Ge-68 point-source holder for PET's calibration. The image volumes obtained from two modalities is registered by a pre-determined, inherent spatial transformation function. This hardware-approach fusion, which provides accurate and no labor-intensive alignment, is suitable for mass scanning. The micro-PET/CT system has been operated successfully. Merging the anatomical and functional images benefit studies of the small animal imaging

  18. Feasibility study of small animal imaging using clinical PET/CT scanner

    Science.gov (United States)

    Hsu, Wen-Lin; Chen, Chia-Lin; Wang, Ze-Jing; Wu, Tung-Hsin; Liu, Dai-Wei; Lee, Jason J. S.

    2007-02-01

    The feasibility of small animal imaging using a clinical positron emission tomography/computed tomography (PET/CT) scanner with [F-18]-fluoro-2-deoxy- D-glucose (FDG) was evaluated. Two protocols in PET/CT system, single-mouse high-resolution mode (SHR) and multi-mouse high throughput mode (MHT) protocol were employed to investigate the ability of the scanner and also explored the performance differences between microPET and clinical PET/CT. In this study, we have found that even the clinical PET/CT scanner could not compete with the microPET scanner, especially in spatial resolution; the high-resolution CT image could advance the anatomical information to sub-millimeter level. Besides, CT-based attenuation correction can improve the image uniformity characteristics and quantification accuracy, and the large bore of a human whole-body scanner broadens the possibility of high throughput studies. Considering all the benefits, clinical PET/CT imaging might be a potential alternative for small animal study.

  19. 小动物PET及PET-CT及其在分子影像学中的应用%Small animal PET and PET-CT its application in molecular imaging

    Institute of Scientific and Technical Information of China (English)

    李天然; 田嘉禾

    2008-01-01

    The review article introduce molecular imaging equipment small animal PET and PET-CT's philosophy and technique feature.small animal PET and PET-CT apply many new techniques and images resolution has obviously raising.as same time,small animal PET and small animal CT may come true image fusion.small animal PET and PET-CT permit us to engage molecular level imaging in vivo without invading.so small animal PET and PET-CT are good tool in medical molecular imaging.%阐述小动物PET及PET-CT技术特点及在分子影像学中的应用.小动物PET及PET-CT采用多项新技术,分辨率明显提高,结合小动物CT实现了图像融合.小动物PET及PET-CT实现了在活体上非侵人性分子水平显像,是研究分子影像的尖端设备.

  20. Importance of Attenuation Correction (AC) for Small Animal PET Imaging

    DEFF Research Database (Denmark)

    El Ali, Henrik H.; Bodholdt, Rasmus Poul; Jørgensen, Jesper Tranekjær;

    2012-01-01

    concentration in the same organ with and without AC revealed an overall attenuation recovery of 9–21% for MAP reconstructed images, i.e., SUV without AC could underestimate the true activity at this level. For subcutaneous tumors, the attenuation was 13 ± 4% (9–17%), for kidneys 20 ± 1% (19...

  1. Evaluation of attenuation and scatter correction requirements in small animal PET and SPECT imaging

    Science.gov (United States)

    Konik, Arda Bekir

    Positron emission tomography (PET) and single photon emission tomography (SPECT) are two nuclear emission-imaging modalities that rely on the detection of high-energy photons emitted from radiotracers administered to the subject. The majority of these photons are attenuated (absorbed or scattered) in the body, resulting in count losses or deviations from true detection, which in turn degrades the accuracy of images. In clinical emission tomography, sophisticated correction methods are often required employing additional x-ray CT or radionuclide transmission scans. Having proven their potential in both clinical and research areas, both PET and SPECT are being adapted for small animal imaging. However, despite the growing interest in small animal emission tomography, little scientific information exists about the accuracy of these correction methods on smaller size objects, and what level of correction is required. The purpose of this work is to determine the role of attenuation and scatter corrections as a function of object size through simulations. The simulations were performed using Interactive Data Language (IDL) and a Monte Carlo based package, Geant4 application for emission tomography (GATE). In IDL simulations, PET and SPECT data acquisition were modeled in the presence of attenuation. A mathematical emission and attenuation phantom approximating a thorax slice and slices from real PET/CT data were scaled to 5 different sizes (i.e., human, dog, rabbit, rat and mouse). The simulated emission data collected from these objects were reconstructed. The reconstructed images, with and without attenuation correction, were compared to the ideal (i.e., non-attenuated) reconstruction. Next, using GATE, scatter fraction values (the ratio of the scatter counts to the total counts) of PET and SPECT scanners were measured for various sizes of NEMA (cylindrical phantoms representing small animals and human), MOBY (realistic mouse/rat model) and XCAT (realistic human model

  2. Kinetic parametric estimation in animal PET molecular imaging based on artificial immune network

    International Nuclear Information System (INIS)

    Objective: To develop an accurate,reliable method without the need of initialization in animal PET modeling for estimation of the tracer kinetic parameters based on the artificial immune network. Methods: The hepatic and left ventricular time activity curves (TACs) were obtained by drawing ROIs of liver tissue and left ventricle on dynamic 18F-FDG PET imaging of small mice. Meanwhile, the blood TAC was analyzed by sampling the tail vein blood at different time points after injection. The artificial immune network for parametric optimization of pharmacokinetics (PKAIN) was adapted to estimate the model parameters and the metabolic rate of glucose (Ki) was calculated. Results: TACs of liver,left ventricle and tail vein blood were obtained.Based on the artificial immune network, Ki in 3 mice was estimated as 0.0024, 0.0417 and 0.0047, respectively. The average weighted residual sum of squares of the output model generated by PKAIN was less than 0.0745 with a maximum standard deviation of 0.0084, which indicated that the proposed PKAIN method can provide accurate and reliable parametric estimation. Conclusion: The PKAIN method could provide accurate and reliable tracer kinetic modeling in animal PET imaging without the need of initialization of model parameters. (authors)

  3. A 3D HIDAC-PET camera with sub-millimeter resolution for imaging small animals

    International Nuclear Information System (INIS)

    A HIDAC-PET camera consisting essentially of 5 million 0.5 mm gas avalanching detectors has been constructed for small-animal imaging. The particular HIDAC advantage--a high 3D spatial resolution--has been improved to 0.95 mm fwhm and to 0.7 mm fwhm when reconstructing with 3D-OSEM methods incorporating resolution recovery. A depth-of-interaction resolution of 2.5 mm is implicit, due to the laminar construction. Scatter-corrected sensitivity, at 8.9 cps/kBq (i.e. 0.9%) from a central point source, or 7.2 cps/kBq (543 cps/kBq/cm3) from a distributed (40 mm diameter, 60 mm long) source is now much higher than previous, and other, work. A field-of-view of 100 mm (adjustable to 200 mm) diameter by 210 mm axially permits whole-body imaging of small animals, containing typically 4MBqs of activity, at 40 kcps of which 16% are random coincidences, with a typical scatter fraction of 44%. Throughout the field-of-view there are no positional distortions and relative quantitation is uniform to ± 3.5%, but some variation of spatial resolution is found. The performance demonstrates that HIDAC technology is quite appropriate for small-animal PET cameras

  4. Application of a semi-automatic ROI setting system for brain PET images to animal PET studies

    International Nuclear Information System (INIS)

    ProASSIST, a semi-automatic ROI (region of interest) setting system for human brain PET images, has been modified for use with the canine brain, and the performance of the obtained system was evaluated by comparing the operational simplicity for ROI setting and the consistency of ROI values obtained with those by a conventional manual procedure. Namely, we created segment maps for the canine brain by making reference to the coronal section atlas of the canine brain by Lim et al., and incorporated them into the ProASSIST system. For the performance test, CBF (cerebral blood flow) and CMRglc (cerebral metabolic rate in glucose) images in dogs with or without focal cerebral ischemia were used. In ProASSIST, brain contours were defined semiautomatically. In the ROI analysis of the test image, manual modification of the contour was necessary in half cases examined (8/16). However, the operation was rather simple so that the operation time per one brain section was significantly shorter than that in the manual operation. The ROI values determined by the system were comparable with those by the manual procedure, confirming the applicability of the system to these animal studies. The use of the system like the present one would also merit the more objective data acquisition for the quantitative ROI analysis, because no manual procedure except for some specifications of the anatomical features is required for ROI setting. (author)

  5. An investigation of the challenges in reconstructing PET images of a freely moving animal

    International Nuclear Information System (INIS)

    Imaging the brain of a freely moving small animal using positron emission tomography (PET) while simultaneously observing its behaviour is an important goal for neuroscience. While we have successfully demonstrated the use of line-of-response (LOR) rebinning to correct the head motion of confined animals, a large proportion of events may need to be discarded because they either 'miss' the detector array after transformation or fall out of the acceptance range of a sinogram. The proportion of events that would have been measured had motion not occurred, so-called 'lost events', is expected to be even larger for freely moving animals. Moreover, the data acquisition in the case of a freely moving animal is further complicated by a complex attenuation field. The aims of this study were (a) to characterise the severity of 'lost events' problem for the freely moving animal scenario, and (b) to investigate the relative impact of attenuation correction errors on quantitative accuracy of reconstructed images. A phantom study was performed to simulate the uncorrelated motion of a target and non-target source volume. A small animal PET scanner was used to acquire list-mode data for different sets of phantom positions. The list-mode data were processed using the standard LOR rebinning approach, and multiple frame variants of this designed to reduce discarded events. We found that LOR rebinning caused up to 86 % 'lost events', and artifacts that we attribute to incomplete projections, when applied to a freely moving target. This fraction was reduced by up to 18 % using the variant approaches, resulting in slightly reduced image artifacts. The effect of the non-target compartment on attenuation correction of the target volume was surprisingly small. However, for certain poses where the target and non-target volumes are aligned transaxially in the field-of-view, the attenuation problem becomes more complex and sophisticated correction methods will be required. We conclude that

  6. Improved automated synthesis and preliminary animal PET/CT imaging of 11C-acetate

    International Nuclear Information System (INIS)

    To study a simple and rapid automated synthetic technology of 11C-acetate (11C- AC), automated synthesis of 11C-AC was performed by carboxylation of MeMgBr/tetrahydrofuran (THF) on a polyethylene loop with 11C-CO2, followed by hydrolysis and purification on solid-phase extraction cartridges using a 11C-Choline/Methionine synthesizer made in China. A high and reproducible radiochemical yield of above 40% (decay corrected) was obtained within the whole synthesis time about 8 min from 11C-CO2. The radiochemical purity of 11C-AC was over 95%. The novel, simple and rapid on-column hydrolysis-purification procedure should adaptable to the fully automated synthesis of 11C-AC at several commercial synthesis module. 11C-AC injection produced by the automated procedure is safe and effective, and can be used for PET imaging of animals and humans. (authors)

  7. Coincidence measurements on detectors for microPET II: A 1 mm3 resolution PET scanner for small animal imaging

    CERN Document Server

    Chatziioannou, A; Shao, Y; Doshi, N K; Silverman, B; Meadors, K; Cherry, SR

    2000-01-01

    We are currently developing a small animal PET scanner with a design goal of 1 mm3 image resolution. We have built three pairs of detectors and tested performance in terms of crystal identification, spatial, energy and timing resolution. The detectors consisted of 12 multiplied by 12 arrays of 1 multiplied by 1 multiplied by 10mm LSO crystals (1.15 mm pitch) coupled to Hamamatsu H7546 64 channel PMTs via 5cm long coherent glass fiber bundles. Optical fiber connection is necessary to allow high packing fraction in a ring geometry scanner. Fiber bundles with and without extramural absorber (EMA) were tested. The results demonstrated an intrinsic spatial resolution of 1.12 mm (direct coupled LSO array), 1.23 mm (bundle without EMA) and 1.27 mm (bundle with EMA) using a similar to 500 micron diameter Na-22 source. Using a 330 micron line source filled with F-18, intrinsic resolution for the EMA bundle improved to 1.05 mm. The respective timing and energy resolution values were 1.96 ns, 21% (direct coupled), 2.20 ...

  8. Performance evaluation of a compact PET/SPECT/CT tri-modality system for small animal imaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Qingyang [Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084 (China); Wang, Shi [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084 (China); Ma, Tianyu, E-mail: maty@tsinghua.edu.cn [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084 (China); Wu, Jing; Liu, Hui; Xu, Tianpeng; Xia, Yan; Fan, Peng; Lyu, Zhenlei; Liu, Yaqiang [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084 (China)

    2015-06-21

    PET, SPECT and CT imaging techniques are widely used in preclinical small animal imaging applications. In this paper, we present a compact small animal PET/SPECT/CT tri-modality system. A dual-functional, shared detector design is implemented which enables PET and SPECT imaging with a same LYSO ring detector. A multi-pinhole collimator is mounted on the system and inserted into the detector ring in SPECT imaging mode. A cone-beam CT consisting of a micro focus X-ray tube and a CMOS detector is implemented. The detailed design and the performance evaluations are reported in this paper. In PET imaging mode, the measured NEMA based spatial resolution is 2.12 mm (FWHM), and the sensitivity at the central field of view (CFOV) is 3.2%. The FOV size is 50 mm (∅)×100 mm (L). The SPECT has a spatial resolution of 1.32 mm (FWHM) and an average sensitivity of 0.031% at the center axial, and a 30 mm (∅)×90 mm (L) FOV. The CT spatial resolution is 8.32 lp/mm @10%MTF, and the contrast discrimination function value is 2.06% with 1.5 mm size cubic box object. In conclusion, a compact, tri-modality PET/SPECT/CT system was successfully built with low cost and high performance.

  9. Performance evaluation of a compact PET/SPECT/CT tri-modality system for small animal imaging applications

    International Nuclear Information System (INIS)

    PET, SPECT and CT imaging techniques are widely used in preclinical small animal imaging applications. In this paper, we present a compact small animal PET/SPECT/CT tri-modality system. A dual-functional, shared detector design is implemented which enables PET and SPECT imaging with a same LYSO ring detector. A multi-pinhole collimator is mounted on the system and inserted into the detector ring in SPECT imaging mode. A cone-beam CT consisting of a micro focus X-ray tube and a CMOS detector is implemented. The detailed design and the performance evaluations are reported in this paper. In PET imaging mode, the measured NEMA based spatial resolution is 2.12 mm (FWHM), and the sensitivity at the central field of view (CFOV) is 3.2%. The FOV size is 50 mm (∅)×100 mm (L). The SPECT has a spatial resolution of 1.32 mm (FWHM) and an average sensitivity of 0.031% at the center axial, and a 30 mm (∅)×90 mm (L) FOV. The CT spatial resolution is 8.32 lp/mm @10%MTF, and the contrast discrimination function value is 2.06% with 1.5 mm size cubic box object. In conclusion, a compact, tri-modality PET/SPECT/CT system was successfully built with low cost and high performance

  10. Using the NEMA NU 4 PET image quality phantom in multipinhole small-animal SPECT

    NARCIS (Netherlands)

    Harteveld, A.A.; Meeuwis, A.P.W.; Disselhorst, J.A.; Slump, C.H.; Oyen, W.J.G.; Boerman, O.C.; Visser, E.P.

    2011-01-01

    Several commercial small-animal SPECT scanners using multipinhole collimation are presently available. However, generally accepted standards to characterize the performance of these scanners do not exist. Whereas for small-animal PET, the National Electrical Manufacturers Association (NEMA) NU 4 sta

  11. Non-Invasive imaging of small-animal tumors: high-frequency ultrasound vs. MicroPET.

    Science.gov (United States)

    Liao, Ai-Ho; Li, Chen-Han; Cheng, Weng-Fang; Li, Pai-Chi

    2005-01-01

    Tumor volume measurement on small animals is important but currently invasive. We employ ultrasonic micro-imaging (UMI) in this study and demonstrate its feasibility. In addition, we use small animal positron emission tomography (microPET) as a preliminary effort to develop multi-modality small animal imaging techniques. The tumor growth curve from UMI is also compared to radioactivity from microPET. Both UMI and [18F] FDG microPET imaging were performed on C57BL/6J black mice bearing WF-3 ovary cancer cells at various stages from the second week till up to the eighth week. Segmentation and 3D reconstruction were also done. The growth curve was obtained in vivo noninvasively by UMI. The cell doubling time was 7.46 days according to UMI. This result was compared with vernier caliper measurement and radioactivity counting by microPET. In microPET, we obtained the time-activity curves from the tumor and the tumor-surrounding tissue. The tumor-to-normal-tissues ratios reached maximum at the fifth week after tumor cell implantation. PMID:17281549

  12. Anesthesia condition for {sup 18}F-FDG imaging of lung metastasis tumors using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Sang-Keun; Lee, Tae Sup; Kim, Kyeong Min; Kim, June-Youp; Jung, Jae Ho; Kang, Joo Hyun [Division of Nuclear Medicine and RI Application, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of); Cheon, Gi Jeong [Division of Nuclear Medicine and RI Application, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of); Department of Nuclear Medicine, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of)], E-mail: larry@kcch.re.kr; Choi, Chang Woon; Lim, Sang Moo [Division of Nuclear Medicine and RI Application, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of); Department of Nuclear Medicine, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of)

    2008-01-15

    Small animal positron emission tomography (PET) with {sup 18}F-FDG has been increasingly used for tumor imaging in the murine model. The aim of this study was to establish the anesthesia condition for imaging of lung metastasis tumor using small animal {sup 18}F-FDG PET. Methods: To determine the impact of anesthesia on {sup 18}F-FDG distribution in normal mice, five groups were studied under the following conditions: no anesthesia, ketamine and xylazine (Ke/Xy), 0.5% isoflurane (Iso 0.5), 1% isoflurane (Iso 1) and 2% isoflurane (Iso 2). The ex vivo counting, standard uptake value (SUV) image and glucose SUV of {sup 18}F-FDG in various tissues were evaluated. The {sup 18}F-FDG images in the lung metastasis tumor model were obtained under no anesthesia, Ke/Xy and Iso 0.5, and registered with CT image to clarify the tumor region. Results: Blood glucose concentration and muscle uptake of {sup 18}F-FDG in the Ke/Xy group markedly increased more than in the other groups. The Iso 2 group increased {sup 18}F-FDG uptake in heart compared with the other groups. The Iso 0.5 anesthesized group showed the lowest {sup 18}F-FDG uptake in heart and chest wall. The small size of lung metastasis tumor (2 mm) was clearly visualized by {sup 18}F-FDG image with the Iso 0.5 anesthesia. Conclusion: Small animal {sup 18}F-FDG PET imaging with Iso 0.5 anesthesia was appropriate for the detection of lung metastasis tumor. To acquire {sup 18}F-FDG PET images with small animal PET, the type and level of anesthetic should be carefully considered to be suitable for the visualization of target tissue in the experimental model.

  13. MicroPET II: design, development and initial performance of an improved microPET scanner for small-animal imaging

    OpenAIRE

    Tai, Y. C.; Chatziioannou, A. F.; Yang, Y. F.; Silverman, R W; Meadors, K; Siegel, S.; Newport, D F; Stickel, J R; Cherry, Simon R.

    2003-01-01

    MicroPET II is a second-generation animal PET scanner designed for high-resolution imaging of small laboratory rodents. The system consists of 90 scintillation detector modules arranged in three contiguous axial rings with a ring diameter of 16.0 cm and an axial length of 4.9 cm. Each detector module consists of a 14 x 14 array of lutetium oxyorthosilicate (LSO) crystals coupled to a multi-channel photomultiplier tube (MC-PMT) through a coherent optical fibre bundle. Each LSO crystal element ...

  14. Imaging of lung metastasis tumor mouse model using [{sup 18}F]FDG small animal PET and CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, June Youp; Woo, Sang Keun; Lee, Tae Sup [Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul (Korea, Republic of)] (and others)

    2007-02-15

    The purpose of this study is to image metastaic lung melanoma model with optimal pre-conditions for animal handling by using [{sup 18}F]FDG small animal PET and clinical CT. The pre-conditions for lung region tumor imaging were 16-22 h fasting and warming temperature at 30 .deg. C. Small animal PET image was obtained at 60 min postinjection of 7.4 MBq [{sup 18}F]FDG and compared pattern of [{sup 18}F]FDG uptake and glucose standard uptake value (SUVG) of lung region between Ketamine/Xylazine (Ke/Xy) and Isoflurane (Iso) anesthetized group in normal mice. Metastasis tumor mouse model to lung was established by intravenous injection of B16-F10 cells in C57BL/6 mice. In lung metastasis tumor model, [{sup 18}F]FDG image was obtained and fused with anatomical clinical CT image. Average blood glucose concentration in normal mice were 128.0 {+-} 22.87 and 86.0 {+-} 21.65 mg/dL in Ke/Xy group and Iso group, respectively. Ke/Xy group showed 1.5 fold higher blood glucose concentration than Iso group. Lung to Background ratio (L/B) in SUVG image was 8.6 {+-} 0.48 and 12.1 {+-}0.63 in Ke/Xy group and Iso group, respectively. In tumor detection in lung region, [{sup 18}F]FDG image of Iso group was better than that of Ke/Xy group, because of high L/B ratio. Metastatic tumor location in [{sup 18}F]FDG small animal PET image was confirmed by fusion image using clinical CT. Tumor imaging in small animal lung region with [{sup 18}F]FDG small animal PET should be considered pre-conditions which fasting, warming and an anesthesia during [{sup 18}F]FDG uptake. Fused imaging with small animal PET and CT image could be useful for the detection of metastatic tumor in lung region.

  15. A microPET/CT system for invivo small animal imaging

    Science.gov (United States)

    Liang, H.; Yang, Y.; Yang, K.; Wu, Y.; Boone, J. M.; Cherry, S. R.

    2007-07-01

    A microCT scanner was designed, fabricated and integrated with a previously reported microPET II scanner (Tai et al 2003 Phys. Med. Biol. 48 1519, Yang et al 2004 Phys. Med. Biol. 49 2527), forming a dual modality system for in vivo anatomic and molecular imaging of the mouse. The system was designed to achieve high-spatial-resolution and high-sensitivity PET images with adequate CT image quality for anatomic localization and attenuation correction with low x-ray dose. The system also has relatively high throughput for screening, and a flexible gantry and user interface. X-rays were produced by a 50 kVp, 1.5 mA fixed tungsten anode tube, with a focal spot size of 70 µm. The detector was a 5 × 5 cm2 photodiode detector incorporating 48 µm pixels on a CMOS array and a fast gadolinium oxysulfide (GOS) intensifying screen. The microCT system has a flexible C-arm gantry design with adjustable detector positioning, which acquires CT projection images around the common microPET/CT bed. The design and the initial characterization of the microCT system is described, and images of the first mouse scans with microPET/CT scanning protocols are shown.

  16. A microPET/CT system for invivo small animal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Liang, H [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States); Yang, Y [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States); Yang, K [Department of Radiology, UC Davis Medical Center, 4701 X Street, X-ray Imaging Laboratory, Sacramento, CA 95817 (United States); Wu, Y [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States); Boone, J M [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States); Cherry, S R [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States)

    2007-07-07

    A microCT scanner was designed, fabricated and integrated with a previously reported microPET II scanner (Tai et al 2003 Phys. Med. Biol. 48 1519, Yang et al 2004 Phys. Med. Biol. 49 2527), forming a dual modality system for in vivo anatomic and molecular imaging of the mouse. The system was designed to achieve high-spatial-resolution and high-sensitivity PET images with adequate CT image quality for anatomic localization and attenuation correction with low x-ray dose. The system also has relatively high throughput for screening, and a flexible gantry and user interface. X-rays were produced by a 50 kVp, 1.5 mA fixed tungsten anode tube, with a focal spot size of 70 {mu}m. The detector was a 5 x 5 cm{sup 2} photodiode detector incorporating 48 {mu}m pixels on a CMOS array and a fast gadolinium oxysulfide (GOS) intensifying screen. The microCT system has a flexible C-arm gantry design with adjustable detector positioning, which acquires CT projection images around the common microPET/CT bed. The design and the initial characterization of the microCT system is described, and images of the first mouse scans with microPET/CT scanning protocols are shown.

  17. Attenuation correction for small animal PET tomographs

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Patrick L [David Geffen School of Medicine at UCLA, Crump Institute for Molecular Imaging, University of California, 700 Westwood Plaza, Los Angeles, CA 90095 (United States); Rannou, Fernando R [Departamento de Ingenieria Informatica, Universidad de Santiago de Chile (USACH), Av. Ecuador 3659, Santiago (Chile); Chatziioannou, Arion F [David Geffen School of Medicine at UCLA, Crump Institute for Molecular Imaging, University of California, 700 Westwood Plaza, Los Angeles, CA 90095 (United States)

    2005-04-21

    Attenuation correction is one of the important corrections required for quantitative positron emission tomography (PET). This work will compare the quantitative accuracy of attenuation correction using a simple global scale factor with traditional transmission-based methods acquired either with a small animal PET or a small animal x-ray computed tomography (CT) scanner. Two phantoms (one mouse-sized and one rat-sized) and two animal subjects (one mouse and one rat) were scanned in CTI Concorde Microsystem's microPET (registered) Focus{sup TM} for emission and transmission data and in ImTek's MicroCAT{sup TM} II for transmission data. PET emission image values were calibrated against a scintillation well counter. Results indicate that the scale factor method of attenuation correction places the average measured activity concentration about the expected value, without correcting for the cupping artefact from attenuation. Noise analysis in the phantom studies with the PET-based method shows that noise in the transmission data increases the noise in the corrected emission data. The CT-based method was accurate and delivered low-noise images suitable for both PET data correction and PET tracer localization.

  18. Assessment of glucose metabolism from the projections using the wavelet technique in small animal pet imaging.

    Science.gov (United States)

    Arhjoul, Lahcen; Bentourkia, M'hamed

    2007-04-01

    The dynamic positron emission tomography (PET) images are usually modeled to extract the physiological parameters. However, to avoid reconstruction of the dynamic sequence of images with subjective data filtering, it is advantageous to apply the kinetic modeling in the projection space and to reconstruct single parametric image slices. Using the advantage of the wavelets to compress the data and to filter the noise in the sinogram, we applied the graphical analysis method (Patlak) to generate a single parametric sinogram (WAV-SINO) from PET data acquired in seven normal rats measured with fluorodeoxyglucose (FDG) in the heart. The same data set was analysed with the graphical method in the spatial domain from the sinograms (USUAL-SINO), and also from images reconstructed with non-filtered backprojection (USUAL-nFBP) and filtered backprojection (USUAL-FBP). The myocardial metabolic rates for glucose (MMRG) obtained with USUAL-nFBP, USUAL-FBP, USUAL-SINO and WAV-SINO were found to be, respectively, 7.54, 6.75, 6.52 and 6.98micromol/100g/min. While the variance with respect to USUAL-FBP was about 142% for USUAL-nFBP, 99.6% for USUAL-SINO and 101.9% for WAV-SINO, the spatial resolution as assessed from the profiles through the myocardial walls of the reconstructed images was 112% for USUAL-FBP and 105% for WAV-SINO relative to the high resolution USUAL-nFBP. The WAV-SINO parametric images showed slightly better visual quality than those obtained from the spatial domain. Finally, the wavelet filtering technique allowed to reduce the computing time, the storage space and particularly the variance in the MMRG parametric images while preserving the spatial resolution.

  19. Establishment study of the in vivo imaging analysis with small animal imaging modalities (micro-PET and micro-SPECT/CT) for bio-drug development

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Beomsu; Park, Sanghyeon; Park, Jeonghoon; Jo, Sungkee; Jung, Uhee; Kim, Seolwha; Lee, Yunjong; Choi, Daeseong

    2011-01-15

    In this study, we established the image acquisition and analysis procedures of micro-PET, SPECT/CT using the experimental animal (mouse) for the development of imaging assessment method for the bio-drug. We examined the micro-SPECT/CT, PET imaging study using the Siemens Inveon micro-multimodality system (SPECT/CT) and micro-PET with {sup 99m}Tc-MDP, DMSA, and {sup 18}F-FDG. SPECT imaging studies using 3 types of pinhole collimators. 5-MWB collimator was used for SPECT image study. To study whole-body distribution, {sup 99m}Tc-MDP SPECT image study was performed. We obtained the fine distribution image. And the CT images was obtained to provide the anatomical information. And then these two types images are fused. To study specific organ uptake, we examined {sup 99}mTc-DMSA SPECT/CT imaging study. We also performed the PET image study using U87MG tumor bearing mice and {sup 18}F-FDG. The overnight fasting, warming and anesthesia with 2% isoflurane pretreatment enhance the tumor image through reducing the background uptake including brown fat, harderian gland and skeletal muscles. Also we got the governmental approval for use of x-ray generator for CT and radioisotopes as sealed and open source. We prepared the draft of process procedure for the experimental animal imaging facility. These research results can be utilized as a basic image study protocols and data for the image assessment of drugs including biological drug.

  20. Design considerations for a C-shaped PET system, dedicated to small animal brain imaging, using GATE Monte Carlo simulations

    Science.gov (United States)

    Efthimiou, N.; Papadimitroulas, P.; Kostou, T.; Loudos, G.

    2015-09-01

    Commercial clinical and preclinical PET scanners rely on the full cylindrical geometry for whole body scans as well as for dedicated organs. In this study we propose the construction of a low cost dual-head C-shaped PET system dedicated for small animal brain imaging. Monte Carlo simulation studies were performed using GATE toolkit to evaluate the optimum design in terms of sensitivity, distortions in the FOV and spatial resolution. The PET model is based on SiPMs and BGO pixelated arrays. Four different configurations with C- angle 0°, 15°, 30° and 45° within the modules, were considered. Geometrical phantoms were used for the evaluation process. STIR software, extended by an efficient multi-threaded ray tracing technique, was used for the image reconstruction. The algorithm automatically adjusts the size of the FOV according to the shape of the detector's geometry. The results showed improvement in sensitivity of ∼15% in case of 45° C-angle compared to the 0° case. The spatial resolution was found 2 mm for 45° C-angle.

  1. Small animal PET imaging of HSV1-tk gene expression with 124IVDU in liver by the hydrodynamic injection

    International Nuclear Information System (INIS)

    The liver is an important target organ for gene transfer due to its capacity for synthesizing serum protein and its involvement in numerous genetic diseases. High level of foreign gene expression in liver can be achieved by a large-volume and high-speed intravenous injection of naked plasmid DNA (pDNA), so called hydrodynamic injection. This study is aimed to evaluate liver specific-gene expression of herpes simplex virus type 1 thymidine kinase(HSV1-tk) by hydrodynamic injection and image HSV1-tk expression using 124IVDU-PET. We constructed herpes simplex virus type 1 thymidine kinase (HSV1-tk)-expressing pDNA (pHSV1-tk) modified from pEGFP-N1. Hydrodynamic injection was performed using 40 μg of plasmid (pEGFP/N1 or pHSV1-tk) in 2 ml of 0.85% saline solution for 20∼22g mice in 5 seconds intravenously. At 1 d post-hydrodynamic injection, biodistribution study was performed at 2 h post-injection of radiolabeled IVDU, fluorescence image was obtained using optical imager and small animal PET image was acquired with 124IVDU at 2 h post-injection. After PET imaging, digital whole body autoradiography (DWBA) was performed. Expression of HSV1-tk and EGFP was confirmed by RT-PCR in each liver tissue. In liver of pHSV1-tk and pEGFP/N1 injection groups, 123IVDU uptake was 5.65%ID/g and 0.98%ID/g, respectively. 123IVDU uptake in liver of pHSV1-tk injection group showed 5.7-fold higher than that of pEGFP/N1 injection group (p124IVDU uptake was selectively localized in liver of pHSV1-tk injection group and also checked in DWBA, but showed minimal uptake in liver of pEGFP/N1 injection mice. Hydrodynamic injection was effective to liver-specific delivery of plasmid DNA. Small animal PET image of 124IVDU could be used in the evaluation of noninvasive reporter gene imaging in liver

  2. Contrast-enhanced small-animal PET/CT in cancer research: strong improvement of diagnostic accuracy without significant alteration of quantitative accuracy and NEMA NU 4–2008 image quality parameters

    OpenAIRE

    Lasnon, Charline; Quak, Elske; Briand, Mélanie; Gu, Zheng; Louis, Marie-Hélène; Aide, Nicolas

    2013-01-01

    Background The use of iodinated contrast media in small-animal positron emission tomography (PET)/computed tomography (CT) could improve anatomic referencing and tumor delineation but may introduce inaccuracies in the attenuation correction of the PET images. This study evaluated the diagnostic performance and accuracy of quantitative values in contrast-enhanced small-animal PET/CT (CEPET/CT) as compared to unenhanced small animal PET/CT (UEPET/CT). Methods Firstly, a NEMA NU 4–2008 phantom (...

  3. The Combination of In vivo 124I-PET and CT Small Animal Imaging for Evaluation of Thyroid Physiology and Dosimetry

    Directory of Open Access Journals (Sweden)

    Henrik H. El-Ali

    2012-06-01

    Full Text Available Objective: A thyroid rat model combining functional and anatomical information would be of great benefit for better modeling of thyroid physiology and for absorbed dose calculations. Our aim was to show that 124I-PET and CT small animal imaging are useful as a combined model for studying thyroid physiology and dose calculation. Methods: Seven rats were subjects for multiple thyroid 124I-imaging and CT-scans. S-values [mGy/MBqs] for different thyroid sizes were simulated. A phantom with spheres was designed for validation of performances of the small animal PET and CT imaging systems. Results: Small animal image-based measurements of the activity amount and the volumes of the spheres with a priori known volumes showed a good agreement with their corresponding actual volumes. The CT scans of the rats showed thyroid volumes from 34–70 mL. Conclusions: The wide span in volumes of thyroid glands indicates the importance of using an accurate volume-measuring technique such as the small animal CT. The small animal PET system was on the other hand able to accurately estimate the activity concentration in the thyroid volumes. We conclude that the combination of the PET and CT image information is essential for quantitative thyroid imaging and accurate thyroid absorbed dose calculation.

  4. Initial results from a PET/planar small animal imaging system

    OpenAIRE

    Siegel, Stefan; Vaquero, Juan José; Aloj, L; Seidel, Jürgen; Jagoda, E.; Gandler, William R.; Eckelman, W. C.; Green, Michael V.

    1999-01-01

    A pair of stationary, opposed scintillation detectors in time coincidence is being used to create planar projection or tomographic images of small animals injected with positronemitting radiotracers. The detectors are comprised of arrays of individual crystals of bismuth germanate coupled to position-sensitive photomultiplier tubes. The system uses FERA (LeCroy Research Systems) charge-sensitive ADCs and a low cost digital YO board as a E R A bus-to-host bridge. In pro...

  5. Small-animal PET imaging of the type 1 and type 2 cannabinoid receptors in a photothrombotic stroke model

    International Nuclear Information System (INIS)

    Recent ex vivo and pharmacological evidence suggests involvement of the endocannabinoid system in the pathophysiology of stroke, but conflicting roles for type 1 and 2 cannabinoid receptors (CB1 and CB2) have been suggested. The purpose of this study was to evaluate CB1 and CB2 receptor binding over time in vivo in a rat photothrombotic stroke model using PET. CB1 and CB2 microPET imaging was performed at regular time-points up to 2 weeks after stroke using [18F]MK-9470 and [11C]NE40. Stroke size was measured using MRI at 9.4 T. Ex vivo validation was performed via immunostaining for CB1 and CB2. Immunofluorescent double stainings were also performed with markers for astrocytes (GFAP) and macrophages/microglia (CD68). [18F]MK-9470 PET showed a strong increase in CB1 binding 24 h and 72 h after stroke in the cortex surrounding the lesion, extending to the insular cortex 24 h after surgery. These alterations were consistently confirmed by CB1 immunohistochemical staining. [11C]NE40 did not show any significant differences between stroke and sham-operated animals, although staining for CB2 revealed minor immunoreactivity at 1 and 2 weeks after stroke in this model. Both CB1+ and CB2+ cells showed minor immunoreactivity for CD68. Time-dependent and regionally strongly increased CB1, but not CB2, binding are early consequences of photothrombotic stroke. Pharmacological interventions should primarily aim at CB1 signalling as the role of CB2 seems minor in the acute and subacute phases of stroke. (orig.)

  6. Small-animal PET imaging of the type 1 and type 2 cannabinoid receptors in a photothrombotic stroke model

    Energy Technology Data Exchange (ETDEWEB)

    Vandeputte, Caroline; Casteels, Cindy; Koole, Michel; Gerits, Anneleen [KU Leuven, Division of Nuclear Medicine, Leuven (Belgium); KU Leuven, Molecular Small Animal Imaging Center, MoSAIC, Leuven (Belgium); Struys, Tom [Hasselt University, Laboratory of Histology, Biomedical Research Institute, Hasselt (Belgium); KU Leuven, Biomedical NMR Unit, Leuven (Belgium); Veghel, Daisy van; Evens, Nele; Bormans, Guy [KU Leuven, Molecular Small Animal Imaging Center, MoSAIC, Leuven (Belgium); KU Leuven, Laboratory of Radiopharmacy, Leuven (Belgium); Dresselaers, Tom; Himmelreich, Uwe [KU Leuven, Molecular Small Animal Imaging Center, MoSAIC, Leuven (Belgium); KU Leuven, Biomedical NMR Unit, Leuven (Belgium); Lambrichts, Ivo [Hasselt University, Laboratory of Histology, Biomedical Research Institute, Hasselt (Belgium); Laere, Koen van [KU Leuven, Division of Nuclear Medicine, Leuven (Belgium); KU Leuven, Molecular Small Animal Imaging Center, MoSAIC, Leuven (Belgium); UZ Leuven, Division of Nuclear Medicine, Leuven (Belgium)

    2012-11-15

    Recent ex vivo and pharmacological evidence suggests involvement of the endocannabinoid system in the pathophysiology of stroke, but conflicting roles for type 1 and 2 cannabinoid receptors (CB{sub 1} and CB{sub 2}) have been suggested. The purpose of this study was to evaluate CB{sub 1} and CB{sub 2} receptor binding over time in vivo in a rat photothrombotic stroke model using PET. CB{sub 1} and CB{sub 2} microPET imaging was performed at regular time-points up to 2 weeks after stroke using [{sup 18}F]MK-9470 and [{sup 11}C]NE40. Stroke size was measured using MRI at 9.4 T. Ex vivo validation was performed via immunostaining for CB{sub 1} and CB{sub 2}. Immunofluorescent double stainings were also performed with markers for astrocytes (GFAP) and macrophages/microglia (CD68). [{sup 18}F]MK-9470 PET showed a strong increase in CB{sub 1} binding 24 h and 72 h after stroke in the cortex surrounding the lesion, extending to the insular cortex 24 h after surgery. These alterations were consistently confirmed by CB{sub 1} immunohistochemical staining. [{sup 11}C]NE40 did not show any significant differences between stroke and sham-operated animals, although staining for CB{sub 2} revealed minor immunoreactivity at 1 and 2 weeks after stroke in this model. Both CB{sub 1} {sup +} and CB{sub 2} {sup +} cells showed minor immunoreactivity for CD68. Time-dependent and regionally strongly increased CB{sub 1}, but not CB{sub 2}, binding are early consequences of photothrombotic stroke. Pharmacological interventions should primarily aim at CB{sub 1} signalling as the role of CB{sub 2} seems minor in the acute and subacute phases of stroke. (orig.)

  7. The Combination of In vivo (124)I-PET and CT Small Animal Imaging for Evaluation of Thyroid Physiology and Dosimetry

    DEFF Research Database (Denmark)

    El-Ali, Henrik H; Eckerwall, Martin; Skovgaard, Dorthe;

    2012-01-01

    OBJECTIVE: A thyroid rat model combining functional and anatomical information would be of great benefit for better modeling of thyroid physiology and for absorbed dose calculations. Our aim was to show that (124)I-PET and CT small animal imaging are useful as a combined model for studying thyroid...... physiology and dose calculation. METHODS: Seven rats were subjects for multiple thyroid (124)I-imaging and CT-scans. S-values [mGy/MBqs] for different thyroid sizes were simulated. A phantom with spheres was designed for validation of performances of the small animal PET and CT imaging systems. RESULTS......: Small animal image-based measurements of the activity amount and the volumes of the spheres with a priori known volumes showed a good agreement with their corresponding actual volumes. The CT scans of the rats showed thyroid volumes from 34-70 mL. CONCLUSIONS: The wide span in volumes of thyroid glands...

  8. I-124 labeled recombinant human annexin V produced by E. coli for apoptosis image using small animal PET

    International Nuclear Information System (INIS)

    Annexin V labeled with radioisotope and optical probe has been used to detect apoptosis. To evaluate annexin V as a multimodal apoptosis imaging agent, large-scale preparation of Annexin V (AV) is preliminary. The aim of this study is to produce and purify recombinant human Annexin V (rh-AV) in E. coli system and radiolabeled rh-AV evaluate in vitro and in vivo apoptosis model system. Annexin V cDNA was obtained from human placenta and rh-AV cloning vector used fusion E. coli vector. Expression vector was based on the E. coli pET system. Induction of rh-AV was used Isopropyl--D-thiogalactoside (IPTG) and purification was used TALON metal affinity resin and T7 - Taq. Purification yield confirmed through SDS-PAGE. In camptothecin (0, 50, 100 uM) induced Jurkat T cell apoptosis model, AV-PI flow cytometry analysis and in vitro binding assay of I-124 labeled rh - AV were performed and compared. Small animal PET images of I-124 labeled rh-AV were obtained in Fas-mediated hepatic apoptosis model. Optimum expression condition was at 37, 250 rpm, 8 hr in 2X YT media including 1mM IPTG, Through two step purification process, rh-AV confirmed about 35 Kd single band by SDS-PAGE. As camptothecin concentration increasing, annexin V-FITC positive % increased in flow cytometry analysis and uptake of I-124 labeled rh-AV also increased. Annexin V-FITC positive % was correlated with and uptake of I-124 labeled rh-AV (R2=0.99). In Fas-mediated hepatic apoptosis model, I-124 labeled rh-AV was selectively localized in liver region in PET image. Recombinant Human annexin V was produced by E. coli system and purified using two step affinity chromatography. Radiolabeled rh-AV was useful for the evaluation of apoptosis in vitro and in vivo model. Recombinant human annexin V could be used as apoptosis imaging agent with various radiolabel and optical probe

  9. I-124 labeled recombinant human annexin V produced by E. coli for apoptosis image using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J. H.; Lee, I. S.; Woo, S. K.; Woo, G. S.; Chung, W. S.; Kang, J. H.; Cheon, G. J.; Choi, C. W.; Urn, S. M. [Korea Institute of Radiological and Medical Sciences, Daejeon (Korea, Republic of)

    2007-07-01

    Annexin V labeled with radioisotope and optical probe has been used to detect apoptosis. To evaluate annexin V as a multimodal apoptosis imaging agent, large-scale preparation of Annexin V (AV) is preliminary. The aim of this study is to produce and purify recombinant human Annexin V (rh-AV) in E. coli system and radiolabeled rh-AV evaluate in vitro and in vivo apoptosis model system. Annexin V cDNA was obtained from human placenta and rh-AV cloning vector used fusion E. coli vector. Expression vector was based on the E. coli pET system. Induction of rh-AV was used Isopropyl--D-thiogalactoside (IPTG) and purification was used TALON metal affinity resin and T7 - Taq. Purification yield confirmed through SDS-PAGE. In camptothecin (0, 50, 100 uM) induced Jurkat T cell apoptosis model, AV-PI flow cytometry analysis and in vitro binding assay of I-124 labeled rh - AV were performed and compared. Small animal PET images of I-124 labeled rh-AV were obtained in Fas-mediated hepatic apoptosis model. Optimum expression condition was at 37, 250 rpm, 8 hr in 2X YT media including 1mM IPTG, Through two step purification process, rh-AV confirmed about 35 Kd single band by SDS-PAGE. As camptothecin concentration increasing, annexin V-FITC positive % increased in flow cytometry analysis and uptake of I-124 labeled rh-AV also increased. Annexin V-FITC positive % was correlated with and uptake of I-124 labeled rh-AV (R{sup 2}=0.99). In Fas-mediated hepatic apoptosis model, I-124 labeled rh-AV was selectively localized in liver region in PET image. Recombinant Human annexin V was produced by E. coli system and purified using two step affinity chromatography. Radiolabeled rh-AV was useful for the evaluation of apoptosis in vitro and in vivo model. Recombinant human annexin V could be used as apoptosis imaging agent with various radiolabel and optical probe.

  10. Non-invasive imaging of acute renal allograft rejection in rats using small animal F-FDG-PET.

    Directory of Open Access Journals (Sweden)

    Stefan Reuter

    Full Text Available BACKGROUND: At present, renal grafts are the most common solid organ transplants world-wide. Given the importance of renal transplantation and the limitation of available donor kidneys, detailed analysis of factors that affect transplant survival are important. Despite the introduction of new and effective immunosuppressive drugs, acute cellular graft rejection (AR is still a major risk for graft survival. Nowadays, AR can only be definitively by renal biopsy. However, biopsies carry a risk of renal transplant injury and loss. Most important, they can not be performed in patients taking anticoagulant drugs. METHODOLOGY/PRINCIPAL FINDINGS: We present a non-invasive, entirely image-based method to assess AR in an allogeneic rat renal transplantation model using small animal positron emission tomography (PET and (18F-fluorodeoxyglucose (FDG. 3 h after i.v. injection of 30 MBq FDG into adult uni-nephrectomized, allogeneically transplanted rats, tissue radioactivity of renal parenchyma was assessed in vivo by a small animal PET-scanner (post operative day (POD 1,2,4, and 7 and post mortem dissection. The mean radioactivity (cps/mm(3 tissue as well as the percent injected dose (%ID was compared between graft and native reference kidney. Results were confirmed by histological and autoradiographic analysis. Healthy rats, rats with acute CSA nephrotoxicity, with acute tubular necrosis, and syngeneically transplanted rats served as controls. FDG-uptake was significantly elevated only in allogeneic grafts from POD 1 on when compared to the native kidney (%ID graft POD 1: 0.54+/-0.06; POD 2: 0.58+/-0.12; POD 4: 0.81+/-0.06; POD 7: 0.77+/-0.1; CTR: 0.22+/-0.01, n = 3-28. Renal FDG-uptake in vivo correlated with the results obtained by micro-autoradiography and the degree of inflammatory infiltrates observed in histology. CONCLUSIONS/SIGNIFICANCE: We propose that graft FDG-PET imaging is a new option to non-invasively, specifically, early detect, and follow

  11. Studies oriented to optimize the image quality of the small animal PET: Clear PET, modifying some of the parameters of the reconstruction algorithm IMF-OSEM 3D on the data acquisition simulated with GAMOS

    International Nuclear Information System (INIS)

    This report presents studies oriented to optimize the image quality of the small animal PET: Clear- PET. Certain figures of merit (FOM) were used to assess a quantitative value of the contrast and delectability of lesions. The optimization was carried out modifying some of the parameters in the reconstruction software of the scanner, imaging a mini-Derenzo phantom and a cylinder phantom with background activity and two hot spheres. Specifically, it was evaluated the incidence of the inter-update Metz filter (IMF) inside the iterative reconstruction algorithm 3D OSEM. The data acquisition was simulated using the GAMOS framework (Monte Carlo simulation). Integrating GAMOS output with the reconstruction software of the scanner was an additional novelty of this work, to achieve this, data sets were written with the list-mode format (LMF) of ClearPET. In order to verify the optimum values obtained, we foresee to make real acquisitions in the ClearPET of CIEMAT. (Author) 17 refs

  12. Demonstration of an Axial PET concept for brain and small animal imaging

    CERN Document Server

    Beltrame, P; Clinthorne, N; Meddi, F; Kagan, H; Braem, A; Pauss, F; Djambazov, L; Lustermann, W; Weilhammer, P; Nessi-Tedaldi, F; Dissertori, G; Renker, D; Schneider, T; Schinzel, D; De Leo, R; Bolle, E; Fanti, V; Rafecas, M; Rudge, A; Stapnes, S; Casella, C; Chesi, E; Seguinot, J; Solevi, P; Joram, C; Oliver, J F

    2011-01-01

    Standard Positron Emission Tomography (PET) cameras need to reach a compromise between spatial resolution and sensitivity. To overcome this limitation we developed a novel concept of PET. Our AX-PET demonstrator is made of LYSO crystals aligned along the z coordinate (patient's axis) and WLS strips orthogonally placed with respect to the crystals. This concept offers full 3D localization of the photon interaction inside the camera. Thus the spatial resolution and the sensitivity can be simultaneously improved and the reconstruction of Compton interactions inside the detector is also possible. Moreover, by means of G-APDs for reading out the photons, both from LYSO and WLS, the detector is insensitive to magnetic fields and it is then suitable to be used in a combined PET/MRI apparatus. A complete Monte Carlo simulation and dedicated reconstruction software have been developed. The two final modules, each composed of 48 crystals and 156 WLS strips, have been built and fully characterized in a dedicated test se...

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

    International Nuclear Information System (INIS)

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

  14. A new animal model for the imaging of melanoma: correlation of FDG PET with clinical outcome, macroscopic aspect and histological classification in Melanoblastoma-bearing Libechov Minipigs

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the Melanoblastoma-bearing Libechov Minipigs (MeLiM) as an animal model of melanoma for in vivo imaging. Serial whole-body 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography (FDG PET) scans were conducted on five MeLiM. In order to explore different clinical stages of the tumoural lesions, each animal was scanned two to four times, at intervals of 30-155 days. PET images were analysed by a semiquantitative method based on the tumour to muscle metabolic ratio. Histology was performed on biopsies taken between or after the scans and the histological grading of the tumours was compared with the FDG uptake. The overall sensitivity of FDG PET for the detection of cutaneous melanoma was 75%; 62.5% of involved lymph nodes were positive. Sensitivity was better for tumours with vertical growth than for flat lesions. FDG PET did not detect tumours with epidermal involvement only, nor did it detect small metastatic foci. The metabolic ratio was correlated with the evolution of the melanoma. FDG PET is effective in the staging of cutaneous melanoma and the follow-up of tumoural extension and regression in Melanoblastoma-bearing Libechov Minipigs. The results obtained in this animal model correlate well with those described in human melanoma. Accordingly, this model may be useful in testing new tracers specific for melanoma and in helping to detect molecules expressed early during tumoural regression. (orig.)

  15. Small-Animal PET Imaging of Tau Pathology with 18F-THK5117 in 2 Transgenic Mouse Models.

    Science.gov (United States)

    Brendel, Matthias; Jaworska, Anna; Probst, Federico; Overhoff, Felix; Korzhova, Viktoria; Lindner, Simon; Carlsen, Janette; Bartenstein, Peter; Harada, Ryuichi; Kudo, Yukitsuka; Haass, Christian; Van Leuven, Fred; Okamura, Nobuyuki; Herms, Jochen; Rominger, Axel

    2016-05-01

    Abnormal accumulation of tau aggregates in the brain is one of the hallmarks of Alzheimer disease neuropathology. We visualized tau deposition in vivo with the previously developed 2-arylquinoline derivative (18)F-THK5117 using small-animal PET in conjunction with autoradiography and immunohistochemistry gold standard assessment in 2 transgenic mouse models expressing hyperphosphorylated tau. Small-animal PET recordings were obtained in groups of P301S (n = 11) and biGT mice (n = 16) of different ages, with age-matched wild-type (WT) serving as controls. After intravenous administration of 16 ± 2 MBq of (18)F-THK5117, a dynamic 90-min emission recording was initiated for P301S mice and during 20-50 min after injection for biGT mice, followed by a 15-min transmission scan. After coregistration to the MRI atlas and scaling to the cerebellum, we performed volume-of-interest-based analysis (SUV ratio [SUVR]) and statistical parametric mapping. Small-animal PET results were compared with autoradiography ex vivo and in vitro and further validated with AT8 staining for neurofibrillary tangles. SUVRs calculated from static recordings during the interval of 20-50 min after tracer injection correlated highly with estimates of binding potential based on the entire dynamic emission recordings (R = 0.85). SUVR increases were detected in the brain stem of aged P301S mice (+11%; P parametric mapping analysis. Saturable binding of the tracer was verified by autoradiographic blocking studies. In the first dedicated small-animal PET study in 2 different transgenic tauopathy mouse models using the tau tracer (18)F-THK5117, the temporal and spatial progression could be visualized in good correlation with gold standard assessments of tau accumulation. The serial small-animal PET method could afford the means for preclinical testing of novel therapeutic approaches by accommodating interanimal variability at baseline, while detection thresholds in young animals have to be considered.

  16. Small-Animal PET Imaging of Tau Pathology with 18F-THK5117 in 2 Transgenic Mouse Models.

    Science.gov (United States)

    Brendel, Matthias; Jaworska, Anna; Probst, Federico; Overhoff, Felix; Korzhova, Viktoria; Lindner, Simon; Carlsen, Janette; Bartenstein, Peter; Harada, Ryuichi; Kudo, Yukitsuka; Haass, Christian; Van Leuven, Fred; Okamura, Nobuyuki; Herms, Jochen; Rominger, Axel

    2016-05-01

    Abnormal accumulation of tau aggregates in the brain is one of the hallmarks of Alzheimer disease neuropathology. We visualized tau deposition in vivo with the previously developed 2-arylquinoline derivative (18)F-THK5117 using small-animal PET in conjunction with autoradiography and immunohistochemistry gold standard assessment in 2 transgenic mouse models expressing hyperphosphorylated tau. Small-animal PET recordings were obtained in groups of P301S (n = 11) and biGT mice (n = 16) of different ages, with age-matched wild-type (WT) serving as controls. After intravenous administration of 16 ± 2 MBq of (18)F-THK5117, a dynamic 90-min emission recording was initiated for P301S mice and during 20-50 min after injection for biGT mice, followed by a 15-min transmission scan. After coregistration to the MRI atlas and scaling to the cerebellum, we performed volume-of-interest-based analysis (SUV ratio [SUVR]) and statistical parametric mapping. Small-animal PET results were compared with autoradiography ex vivo and in vitro and further validated with AT8 staining for neurofibrillary tangles. SUVRs calculated from static recordings during the interval of 20-50 min after tracer injection correlated highly with estimates of binding potential based on the entire dynamic emission recordings (R = 0.85). SUVR increases were detected in the brain stem of aged P301S mice (+11%; P parametric mapping analysis. Saturable binding of the tracer was verified by autoradiographic blocking studies. In the first dedicated small-animal PET study in 2 different transgenic tauopathy mouse models using the tau tracer (18)F-THK5117, the temporal and spatial progression could be visualized in good correlation with gold standard assessments of tau accumulation. The serial small-animal PET method could afford the means for preclinical testing of novel therapeutic approaches by accommodating interanimal variability at baseline, while detection thresholds in young animals have to be considered

  17. Characteristics of a multichannel low-noise front-end ASIC for CZT-based small animal PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gao, W., E-mail: gaowu@nwpu.edu.cn [Institute of Microelectronics, School of Computer S and T, Northwestern Polytechnical University, Xi’an (China); Liu, H., E-mail: newhui.cn@gmail.com [Institute of Microelectronics, School of Computer S and T, Northwestern Polytechnical University, Xi’an (China); Gan, B., E-mail: shadow524@163.com [Institute of Microelectronics, School of Computer S and T, Northwestern Polytechnical University, Xi’an (China); Hu, Y., E-mail: Yann.Hu@ires.in2p3.fr [Institut Pluridisciplinaire Hubert Curien, IN2P3/CNRS/UDS, Strasbourg (France)

    2014-05-01

    In this paper, we present the design and characteristics of a novel low-noise front-end readout application-specific integrated circuit dedicated to CdZnTe (CZT) detectors for a small animal PET imaging system. A low-noise readout method based on the charge integration and the delayed peak detection is proposed. An eight-channel front-end readout prototype chip is designed and implemented in a 0.35 μm CMOS process. The die size is 2.3 mm ×2.3 mm. The prototype chip is tested in different methods including electronic test, energy spectrum test and irradiation test. The input range of the ASIC is from 2000e{sup −} to 180,000e{sup −}, reflecting the energy of the gamma ray from 11.2 keV to 1 MeV. The gain of the readout channel is 65 mV/fC at the shaping time of 1 μs. The best test result of the equivalent noise charge (ENC) is 58.9 e{sup −} at zero farad plus 5.4 e{sup −} per picofarad. The nonlinearity and the crosstalk are less than 3% and less than 2%, respectively, at the room temperature. The static power dissipation is about 3 mW/channel.

  18. Comparison of 3D Maximum A Posteriori and Filtered Backprojection algorithms for high resolution animal imaging in microPET

    Energy Technology Data Exchange (ETDEWEB)

    Chatziioannou, A.; Qi, J.; Moore, A.; Annala, A.; Nguyen, K.; Leahy, R.M.; Cherry, S.R.

    2000-01-01

    We have evaluated the performance of two three dimensional reconstruction algorithms with data acquired from microPET, a high resolution tomograph dedicated to small animal imaging. The first was a linear filtered-backprojection algorithm (FBP) with reprojection of the missing data and the second was a statistical maximum-aposteriori probability algorithm (MAP). The two algorithms were evaluated in terms of their resolution performance, both in phantoms and in vivo. Sixty independent realizations of a phantom simulating the brain of a baby monkey were acquired, each containing 3 million counts. Each of these realizations was reconstructed independently with both algorithms. The ensemble of the sixty reconstructed realizations was used to estimate the standard deviation as a measure of the noise for each reconstruction algorithm. More detail was recovered in the MAP reconstruction without an increase in noise relative to FBP. Studies in a simple cylindrical compartment phantom demonstrated improved recovery of known activity ratios with MAP. Finally in vivo studies also demonstrated a clear improvement in spatial resolution using the MAP algorithm. The quantitative accuracy of the MAP reconstruction was also evaluated by comparison with autoradiography and direct well counting of tissue samples and was shown to be superior.

  19. Characteristics of a multichannel low-noise front-end ASIC for CZT-based small animal PET imaging

    Science.gov (United States)

    Gao, W.; Liu, H.; Gan, B.; Hu, Y.

    2014-05-01

    In this paper, we present the design and characteristics of a novel low-noise front-end readout application-specific integrated circuit dedicated to CdZnTe (CZT) detectors for a small animal PET imaging system. A low-noise readout method based on the charge integration and the delayed peak detection is proposed. An eight-channel front-end readout prototype chip is designed and implemented in a 0.35 μm CMOS process. The die size is 2.3 mm ×2.3 mm. The prototype chip is tested in different methods including electronic test, energy spectrum test and irradiation test. The input range of the ASIC is from 2000e- to 180,000e-, reflecting the energy of the gamma ray from 11.2 keV to 1 MeV. The gain of the readout channel is 65 mV/fC at the shaping time of 1 μs. The best test result of the equivalent noise charge (ENC) is 58.9 e- at zero farad plus 5.4 e- per picofarad. The nonlinearity and the crosstalk are less than 3% and less than 2%, respectively, at the room temperature. The static power dissipation is about 3 mW/channel.

  20. Characteristics of a multichannel low-noise front-end ASIC for CZT-based small animal PET imaging

    International Nuclear Information System (INIS)

    In this paper, we present the design and characteristics of a novel low-noise front-end readout application-specific integrated circuit dedicated to CdZnTe (CZT) detectors for a small animal PET imaging system. A low-noise readout method based on the charge integration and the delayed peak detection is proposed. An eight-channel front-end readout prototype chip is designed and implemented in a 0.35 μm CMOS process. The die size is 2.3 mm ×2.3 mm. The prototype chip is tested in different methods including electronic test, energy spectrum test and irradiation test. The input range of the ASIC is from 2000e− to 180,000e−, reflecting the energy of the gamma ray from 11.2 keV to 1 MeV. The gain of the readout channel is 65 mV/fC at the shaping time of 1 μs. The best test result of the equivalent noise charge (ENC) is 58.9 e− at zero farad plus 5.4 e− per picofarad. The nonlinearity and the crosstalk are less than 3% and less than 2%, respectively, at the room temperature. The static power dissipation is about 3 mW/channel

  1. Comparison of 3D Maximum A Posteriori and Filtered Backprojection algorithms for high resolution animal imaging in microPET

    International Nuclear Information System (INIS)

    We have evaluated the performance of two three dimensional reconstruction algorithms with data acquired from microPET, a high resolution tomograph dedicated to small animal imaging. The first was a linear filtered-backprojection algorithm (FBP) with reprojection of the missing data and the second was a statistical maximum-aposteriori probability algorithm (MAP). The two algorithms were evaluated in terms of their resolution performance, both in phantoms and in vivo. Sixty independent realizations of a phantom simulating the brain of a baby monkey were acquired, each containing 3 million counts. Each of these realizations was reconstructed independently with both algorithms. The ensemble of the sixty reconstructed realizations was used to estimate the standard deviation as a measure of the noise for each reconstruction algorithm. More detail was recovered in the MAP reconstruction without an increase in noise relative to FBP. Studies in a simple cylindrical compartment phantom demonstrated improved recovery of known activity ratios with MAP. Finally in vivo studies also demonstrated a clear improvement in spatial resolution using the MAP algorithm. The quantitative accuracy of the MAP reconstruction was also evaluated by comparison with autoradiography and direct well counting of tissue samples and was shown to be superior

  2. Simultaneous PET and MR imaging

    International Nuclear Information System (INIS)

    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 2x2x10mm3 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)

  3. PET and SPECT imaging in veterinary medicine.

    Science.gov (United States)

    LeBlanc, Amy K; Peremans, Kathelijne

    2014-01-01

    Veterinarians have gained increasing access to positron emission tomography (PET and PET/CT) imaging facilities, allowing them to use this powerful molecular imaging technique for clinical and research applications. SPECT is currently being used more in Europe than in the United States and has been shown to be useful in veterinary oncology and in the evaluation of orthopedic diseases. SPECT brain perfusion and receptor imaging is used to investigate behavioral disorders in animals that have interesting similarities to human psychiatric disorders. This article provides an overview of the potential applications of PET and SPECT. The use of commercially available and investigational PET radiopharmaceuticals in the management of veterinary disease has been discussed. To date, most of the work in this field has utilized the commercially available PET tracer, (18)F-fluorodeoxyglucose for oncologic imaging. Normal biodistribution studies in several companion animal species (cats, dogs, and birds) have been published to assist in lesion detection and interpretation for veterinary radiologists and clinicians. Studies evaluating other (18)F-labeled tracers for research applications are underway at several institutions and companion animal models of human diseases are being increasingly recognized for their value in biomarker and therapy development. Although PET and SPECT technologies are in their infancy for clinical veterinary medicine, increasing access to and interest in these applications and other molecular imaging techniques has led to a greater knowledge and collective body of expertise for veterinarians worldwide. Initiation and fostering of physician-veterinarian collaborations are key components to the forward movement of this field.

  4. The influence of the image reconstruction in relative quantification in SPECT/PET/CT animal; A influencia da reconstrucao da imagem na quantificacao relativa em SPECT/PET/CT animal

    Energy Technology Data Exchange (ETDEWEB)

    Soriano, Sarah; Sa, Lidia Vasconcellos de, E-mail: sarahsoriano@bolsista.ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ),Rio de Janeiro, RJ (Brazil); Souza, Sergio; Barboza, Thiago [Hospital Universitario Clementino Fraga Filho (HUCFF/UFRJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    The objective of this study is to evaluate the spatial resolution of the equipment SPECT/PET/CT animal to different reconstruction methods and the influence of this parameter in the mouse dosimetry C57BL6, aimed at development of new radiopharmaceuticals for use in humans. CT and SPECT images were obtained from a simulator composed of four spheres of different diameters (d), which simulate captating lesions by the equipment FLEX ™ Triumph ™ Pre-Clinical Imaging System used for preclinical studies in the Hospital Universitario (HU/UFRJ). In order to simulate a real study, the total volume of the simulator (body) was filled with a solution of {sup 99m}Tc diluted in water and the spheres were filled with concentrations four time higher than the body of the simulator. From the gross SPECT images it was used filtered backprojection method (FBP) with application of different filters: Hamming, Hann and Ramp, ranging the cutoff frequencies. The resolution of the equipment found in the study was 9.3 to 9.4 mm, very below the value provided by the manufacturer of 1.6mm. Thus, the protocol for mice can be optimized as being the FBP reconstruction method of Hamming filter, cutoff of 0.5 to yield a resolution from 9.3 to 9.4mm. This value indicates that captating regions of diameter below 9.3 mm are not properly quantified.

  5. Assessment of myocardial metabolic rate of glucose by means of Bayesian ICA and Markov Chain Monte Carlo methods in small animal PET imaging

    Science.gov (United States)

    Berradja, Khadidja; Boughanmi, Nabil

    2016-09-01

    In dynamic cardiac PET FDG studies the assessment of myocardial metabolic rate of glucose (MMRG) requires the knowledge of the blood input function (IF). IF can be obtained by manual or automatic blood sampling and cross calibrated with PET. These procedures are cumbersome, invasive and generate uncertainties. The IF is contaminated by spillover of radioactivity from the adjacent myocardium and this could cause important error in the estimated MMRG. In this study, we show that the IF can be extracted from the images in a rat heart study with 18F-fluorodeoxyglucose (18F-FDG) by means of Independent Component Analysis (ICA) based on Bayesian theory and Markov Chain Monte Carlo (MCMC) sampling method (BICA). Images of the heart from rats were acquired with the Sherbrooke small animal PET scanner. A region of interest (ROI) was drawn around the rat image and decomposed into blood and tissue using BICA. The Statistical study showed that there is a significant difference (p < 0.05) between MMRG obtained with IF extracted by BICA with respect to IF extracted from measured images corrupted with spillover.

  6. Can hypoxia-PET map hypoxic cell density heterogeneity accurately in an animal tumor model at a clinically obtainable image contrast?

    International Nuclear Information System (INIS)

    Background: PET allows non-invasive mapping of tumor hypoxia, but the combination of low resolution, slow tracer adduct-formation and slow clearance of unbound tracer remains problematic. Using a murine tumor with a hypoxic fraction within the clinical range and a tracer post-injection sampling time that results in clinically obtainable tumor-to-reference tissue activity ratios, we have analyzed to what extent inherent limitations actually compromise the validity of PET-generated hypoxia maps. Materials and methods: Mice bearing SCCVII tumors were injected with the PET hypoxia-marker fluoroazomycin arabinoside (FAZA), and the immunologically detectable hypoxia marker, pimonidazole. Tumors and reference tissue (muscle, blood) were harvested 0.5, 2 and 4 h after FAZA administration. Tumors were analyzed for global (well counter) and regional (autoradiography) tracer distribution and compared to pimonidazole as visualized using immunofluorescence microscopy. Results: Hypoxic fraction as measured by pimonidazole staining ranged from 0.09 to 0.32. FAZA tumor to reference tissue ratios were close to unity 0.5 h post-injection but reached values of 2 and 6 when tracer distribution time was prolonged to 2 and 4 h, respectively. A fine-scale pixel-by-pixel comparison of autoradiograms and immunofluorescence images revealed a clear spatial link between FAZA and pimonidazole-adduct signal intensities at 2 h and later. Furthermore, when using a pixel size that mimics the resolution in PET, an excellent correlation between pixel FAZA mean intensity and density of hypoxic cells was observed already at 2 h post-injection. Conclusions: Despite inherent weaknesses, PET-hypoxia imaging is able to generate quantitative tumor maps that accurately reflect the underlying microscopic reality (i.e., hypoxic cell density) in an animal model with a clinical realistic image contrast.

  7. PET radiopharmaceuticals for neuroreceptor imaging

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Routine clinical PET radiopharmaceuticals for the noninvasive imaging of brain receptors, transporters,and enzymes are commonly labeled with positron emitting nuclides such as carbon-11 or fluorine-18. Certain minimal conditions need to be fulfilled for these PET ligands to be used as imaging agents in vivo. Some of these prerequisites are discussed and examples of the most useful clinical PET radiopharmaceuticals that have found application in the central nervous system are reviewed.

  8. Noninvasive image derived heart input function for CMRglc measurements in small animal slow infusion FDG PET studies.

    Science.gov (United States)

    Xiong, Guoming; Paul, Cumming; Todica, Andrei; Hacker, Marcus; Bartenstein, Peter; Böning, Guido

    2012-12-01

    Absolute quantitation of the cerebral metabolic rate for glucose (CMRglc) can be obtained in positron emission tomography (PET) studies when serial measurements of the arterial [(18)F]-fluoro-deoxyglucose (FDG) input are available. Since this is not always practical in PET studies of rodents, there has been considerable interest in defining an image-derived input function (IDIF) by placing a volume of interest (VOI) within the left ventricle of the heart. However, spill-in arising from trapping of FDG in the myocardium often leads to progressive contamination of the IDIF, which propagates to underestimation of the magnitude of CMRglc. We therefore developed a novel, non-invasive method for correcting the IDIF without scaling to a blood sample. To this end, we first obtained serial arterial samples and dynamic FDG-PET data of the head and heart in a group of eight anaesthetized rats. We fitted a bi-exponential function to the serial measurements of the IDIF, and then used the linear graphical Gjedde-Patlak method to describe the accumulation in myocardium. We next estimated the magnitude of myocardial spill-in reaching the left ventricle VOI by assuming a Gaussian point-spread function, and corrected the measured IDIF for this estimated spill-in. Finally, we calculated parametric maps of CMRglc using the corrected IDIF, and for the sake of comparison, relative to serial blood sampling from the femoral artery. The uncorrected IDIF resulted in 20% underestimation of the magnitude of CMRglc relative to the gold standard arterial input method. However, there was no bias with the corrected IDIF, which was robust to the variable extent of myocardial tracer uptake, such that there was a very high correlation between individual CMRglc measurements using the corrected IDIF with gold-standard arterial input results. Based on simulation, we furthermore find that electrocardiogram-gating, i.e. ECG-gating is not necessary for IDIF quantitation using our approach. PMID:23160517

  9. PET and PET/CT for imaging of prostate cancer

    International Nuclear Information System (INIS)

    This review article provides an overview of the current literature data regarding the value of PET and PET/CT for imaging of prostate cancer. Most widely used PET tracers for prostate cancer imaging are 11C-acetate and 11C- or 18F-labeled choline. Available literature data on the performance of PET and PET/CT in the detection of the primary malignancy as well as local or distant metastases are presented and discussed. In addition, our own preliminary results regarding the diagnostic efficacy of 11C-choline PET and PET/CT in 43 patients with suspected prostate cancer are provided. The prevalence of prostate cancer in this patient sample was 55.8%. PET and PET/CT showed a sensitivity of 88% with a specificity of 63% in the detection of the primary prostate cancer. The sensitivity in the detection of metastatic spread was 77% and no false-positives were found. The possible value and limitations of combined PET/CT systems when compared to stand alone PET scanners are discussed. PET and PET/CT is at present the single imaging modality providing functional information not only regarding the primary malignancy but also its metastases. This unique feature distinguishes PET from MRI complemented with magnetic resonance spectroscopy - a competing procedure. Our own results as well as the still limited literature data suggest, that PET and PET/CT may prove to be useful methods for imaging of prostate cancer. (orig.)

  10. Cold wall effect eliminating method to determine the contrast recovery coefficient for small animal PET scanners using the NEMA NU-4 image quality phantom

    Science.gov (United States)

    Lajtos, Imre; Czernin, Johannes; Dahlbom, Magnus; Daver, Freddie; Emri, Miklos; Farshchi-Heydari, Salman; Forgacs, Attila; Hoh, Carl K.; Joszai, Istvan; Krizsan, Aron K.; Lantos, Judit; Major, Peter; Molnar, Jozsef; Opposits, Gabor; Tron, Lajos; Vera, David R.; Balkay, Laszlo

    2014-06-01

    The contrast recovery coefficients (CRC) were evaluated for five different small animal PET scanners: GE Explore Vista, Genisys4, MiniPET-2, nanoScan PC and Siemens Inveon. The NEMA NU-4 2008 performance test with the suggested image quality phantom (NU4IQ) does not allow the determination of the CRC values for the hot regions in the phantom. This drawback of NU4IQ phantom motivated us to develop a new method for this purpose. The method includes special acquisition and reconstruction protocols using the original phantom, and results in an artificially merged image enabling the evaluation of CRC values. An advantageous feature of this method is that it stops the cold wall effect from distorting the CRC calculation. Our suggested protocol results in a set of CRC values contributing to the characterization of small animal PET scanners. GATE simulations were also performed to validate the new method and verify the evaluated CRC values. We also demonstrated that the numerical values of this parameter depend on the actual object contrast of the hot region(s) and this mainly comes from the spillover effect. This effect was also studied while analysing the background activity level around the hot rods. We revealed that the calculated background mean values depended on the target contrast in a scanner specific manner. Performing the artificially merged imaging procedure and additional simulations using the micro hollow sphere (MHS) phantom geometry, we also proved that the inactive wall around the hot spheres can have a remarkable impact on the calculated CRC. In conclusion, we have shown that the proposed artificial merging procedure and the commonly used NU4IQ phantom prescribed by the NEMA NU-4 can easily deliver reliable CRC data otherwise unavailable for the NU4IQ phantom in the conventional protocol or the MHS phantom.

  11. Cold wall effect eliminating method to determine the contrast recovery coefficient for small animal PET scanners using the NEMA NU-4 image quality phantom

    International Nuclear Information System (INIS)

    The contrast recovery coefficients (CRC) were evaluated for five different small animal PET scanners: GE Explore Vista, Genisys4, MiniPET-2, nanoScan PC and Siemens Inveon. The NEMA NU-4 2008 performance test with the suggested image quality phantom (NU4IQ) does not allow the determination of the CRC values for the hot regions in the phantom. This drawback of NU4IQ phantom motivated us to develop a new method for this purpose. The method includes special acquisition and reconstruction protocols using the original phantom, and results in an artificially merged image enabling the evaluation of CRC values. An advantageous feature of this method is that it stops the cold wall effect from distorting the CRC calculation. Our suggested protocol results in a set of CRC values contributing to the characterization of small animal PET scanners. GATE simulations were also performed to validate the new method and verify the evaluated CRC values. We also demonstrated that the numerical values of this parameter depend on the actual object contrast of the hot region(s) and this mainly comes from the spillover effect. This effect was also studied while analysing the background activity level around the hot rods. We revealed that the calculated background mean values depended on the target contrast in a scanner specific manner. Performing the artificially merged imaging procedure and additional simulations using the micro hollow sphere (MHS) phantom geometry, we also proved that the inactive wall around the hot spheres can have a remarkable impact on the calculated CRC. In conclusion, we have shown that the proposed artificial merging procedure and the commonly used NU4IQ phantom prescribed by the NEMA NU-4 can easily deliver reliable CRC data otherwise unavailable for the NU4IQ phantom in the conventional protocol or the MHS phantom. (paper)

  12. Animal biodistribution,safety and validation study of dopamine transporter PET imaging agent 18F-FECNT

    Institute of Scientific and Technical Information of China (English)

    WANG Songpei; CHEN Zhengping; LI Xiaomin; TANG Jie; LILT Chunyi; ZOU Meifen; PAN Donghui; LU Chunxiong; XU Yuping; XU Xijie; ZHOU Xingqin; JIN Jian

    2009-01-01

    This work was to investigate the pharmacologic characteristics of 18F-FECNT (2β-carbomethoxy-3β-(4-chlorophenyl)-8-(2-[18F]fluorcethyl)nortropane) as a dopamine transporter (DAT) PET imaging agent.Its partition coefficients were determined in n-octanol and phosphate buffer (PB) (pH 7.0 and pH 7.4).6-Hydroxydopamine (6-OHDA) left-sided lesioned Parkinsonian rats were established and validated by rotational behavior tests.Biodistribution in vivo in mice,autoradiography in normal and hemi-Parkinsonian rat brains,and toxicity test were performed.The results showed that partition coefficients were 34.14 (pH 7.0) and 56.41 (pH 7.4),respectively.Biodistribution exhibited rapid uptake and favorable retention in the mice brains.The major radioactivity was metabolized by the hepatic system.The autoradiography showed that 18F-FECNT was highly concentrated in striaturn,and that the left and the tight striatal uptake were symmetrical in normal SD rat brains.In left-sided lesioned PD rat brains,the striatal uptake of 18F-FECNT bilaterally decreased in comparison with normal rats.No significant uptake was visible in the 6-OHDA lesioned-sided striatal areas.The results demonstrated that 18F-FECNT binds to DAT was specific.Toxicity trial displayed that the acceptable dose per kilogram to mice was 625 times greater than that to human.These indicate that 18F-FECNT is a potentially safe and useful DAT PET imaging agent in the brain.

  13. Towards very high resolution RPC-PET for small animals

    International Nuclear Information System (INIS)

    We present imaging results of needle-like and planar 22Na sources obtained with a prototype of a high-acceptance small-animal positron emission tomograph based on resistive plate chambers (RPC-PET). The maximum-likelihood expectation-maximization (MLEM) reconstruction of the acquired data yielded an excellent and stable resolution of 0.4 mm FWHM

  14. Emotional Support Animals, Service Animals, and Pets on Campus

    Science.gov (United States)

    Von Bergen, C. W.

    2015-01-01

    For decades, universities have been accommodating physically disabled students who require guide dogs and other types of service animals. Within the past several years, however, mentally disabled students have increasingly petitioned colleges with no-pet policies to permit them to bring their animals on campus because they need a companion or…

  15. Exercises in PET Image Reconstruction

    Science.gov (United States)

    Nix, Oliver

    These exercises are complementary to the theoretical lectures about positron emission tomography (PET) image reconstruction. They aim at providing some hands on experience in PET image reconstruction and focus on demonstrating the different data preprocessing steps and reconstruction algorithms needed to obtain high quality PET images. Normalisation, geometric-, attenuation- and scatter correction are introduced. To explain the necessity of those some basics about PET scanner hardware, data acquisition and organisation are reviewed. During the course the students use a software application based on the STIR (software for tomographic image reconstruction) library 1,2 which allows them to dynamically select or deselect corrections and reconstruction methods as well as to modify their most important parameters. Following the guided tutorial, the students get an impression on the effect the individual data precorrections have on image quality and what happens if they are forgotten. Several data sets in sinogram format are provided, such as line source data, Jaszczak phantom data sets with high and low statistics and NEMA whole body phantom data. The two most frequently used reconstruction algorithms in PET image reconstruction, filtered back projection (FBP) and the iterative OSEM (ordered subset expectation maximation) approach are used to reconstruct images. The exercise should help the students gaining an understanding what the reasons for inferior image quality and artefacts are and how to improve quality by a clever choice of reconstruction parameters.

  16. MR-based Motion Correction for PET Imaging

    Science.gov (United States)

    Ouyang, Jinsong; Li, Quanzheng; Fakhri, Georges El

    2012-01-01

    PET image quality is limited by patient motion. Emission data are blurred due to cardiac and/or respiratory motion. Although spatial resolution is 4 mm for standard clinical whole-body PET scanners, the effective resolution can be a low as 1 cm due to motion. Additionally, the deformation of attenuation medium causes image artifacts. Previously, gating is used to “freeze” the motion, but leads to significantly increased noise level. Simultaneous PET-MR modality offers a new way to perform PET motion correction. MR can be used to measure 3D motion fields, which can then be incorporated into the iterative PET reconstruction to obtain motion corrected PET images. In this report, we present MR imaging techniques to acquire dynamic images, a non-rigid image registration algorithm to extract motion fields from acquired MR images, and a PET reconstruction algorithm with motion correction. We also present results from both phantom and in-vivo animal PET-MR studies. We demonstrate that MR-based PET motion correction using simultaneous PET-MR improves image quality and lesion detectability compared to gating and to no motion correction. PMID:23178089

  17. Design of a small animal MR compatible PET scanner

    International Nuclear Information System (INIS)

    Using a combination of Monte-Carlo simulations and experimental measurements, the authors have designed a small animal MR compatible PET (McPET) scanner for simultaneous PET and MR imaging of mice and rats in vivo. The scanner consists of one ring of 480 LSO crystals arranged in 3 layers with 160 crystals per layer. The crystal dimensions are 2 x 3 x 7.5 mm3. This was based on a target resolution of 2.5 mm and simulations showing that a depth of 7.5 mm avoided significant depth of interaction effects across the desired field of view. The system diameter of 11.2 cm is large enough to accommodate the animal positioned inside a stereotactic frame. Each crystal will be coupled through 2 mm diameter optical fibers to multi-channel PMT's which reside outside the main magnetic field. Through 50 cm of optical fiber, a photopeak is clearly seen and the measured energy resolution is 25%. Prototype optical fiber connectors have been tested to increase the flexibility of the system and result in a light loss of only 6%. The proposed system will have adequate resolution and sensitivity for a number of applications in small animals and will be the first practical device for simultaneous in vivo imaging with PET and MR

  18. Quantitative evaluation of PET image using event information bootstrap

    Science.gov (United States)

    Song, Hankyeol; Kwak, Shin Hye; Kim, Kyeong Min; Kang, Joo Hyun; Chung, Yong Hyun; Woo, Sang-Keun

    2016-04-01

    The purpose of this study was to enhance the effect in the PET image quality according to event bootstrap of small animal PET data. In order to investigate the time difference condition, realigned sinograms were generated from randomly sampled data set using bootstrap. List-mode data was obtained from small animal PET scanner for Ge-68 30 sec, Y-90 20 min and Y-90 60 min. PET image was reconstructed by Ordered Subset Expectation Maximization(OSEM) 2D with the list-mode format. Image analysis was investigated by Signal to Noise Ratio(SNR) of Ge-68 and Y-90 image. Non-parametric resampled PET image SNR percent change for the Ge-68 30 sec, Y-90 60 min, and Y-90 20 min was 1.69 %, 7.03 %, and 4.78 %, respectively. SNR percent change of non-parametric resampled PET image with time difference condition was 1.08 % for the Ge-68 30 sec, 6.74 % for the Y-90 60 min and 10.94 % for the Y-90 29 min. The result indicated that the bootstrap with time difference condition had a potential to improve a noisy Y-90 PET image quality. This method should be expected to reduce Y-90 PET measurement time and to enhance its accuracy.

  19. Diagnostic imaging of exotic pets

    International Nuclear Information System (INIS)

    Radiographic, ultrasonographic, and computed tomographic (CT) imaging are important diagnostic modalities in exotic pets. The use of appropriate radiographic equipment, film-screen combinations, and radiographic projections enhances the information obtained from radiographs. Both normal findings and common radiographic abnormalities are discussed. The use of ultrasonography and CT scanning for exotic small mammals and reptiles is described

  20. 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

  1. PET/MR Imaging in Heart Disease.

    Science.gov (United States)

    Rischpler, Christoph; Nekolla, Stephan G

    2016-10-01

    Hybrid PET/MR imaging is a complex imaging modality that has raised high expectations not only for oncological and neurologic imaging applications, but also for cardiac imaging applications. Initially, physicians and physicists had to become accustomed to technical challenges including attenuation correction, gating, and more complex workflow and more elaborate image analysis as compared with PET/CT or standalone MR imaging. PET/MR imaging seems to be particularly valuable to assess inflammatory myocardial diseases (such as sarcoidosis), to cross-validate PET versus MR imaging data (eg, myocardial perfusion imaging), and to help validate novel biomarkers of various disease states (eg, postinfarction inflammation). PMID:27593250

  2. FDG PET imaging dementia

    International Nuclear Information System (INIS)

    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. 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.

  4. Attenuation correction for the NIH ATLAS small animal PET scanner

    CERN Document Server

    Yao, Rutao; Liow, JeihSan; Seidel, Jurgen

    2003-01-01

    We evaluated two methods of attenuation correction for the NIH ATLAS small animal PET scanner: 1) a CT-based method that derives 511 keV attenuation coefficients (mu) by extrapolation from spatially registered CT images; and 2) an analytic method based on the body outline of emission images and an empirical mu. A specially fabricated attenuation calibration phantom with cylindrical inserts that mimic different body tissues was used to derive the relationship to convert CT values to (I for PET. The methods were applied to three test data sets: 1) a uniform cylinder phantom, 2) the attenuation calibration phantom, and 3) a mouse injected with left bracket **1**8F right bracket FDG. The CT-based attenuation correction factors were larger in non-uniform regions of the imaging subject, e.g. mouse head, than the analytic method. The two methods had similar correction factors for regions with uniform density and detectable emission source distributions.

  5. A new generation of PET scanners for small animal studies

    International Nuclear Information System (INIS)

    Complete text of publication follows. Research on small animal PET scanners has been a hot topic in recent years. These devices are used in the preclinical phases of drug tests and during the development of new radiopharmaceuticals. They also provide a cost efficient way to test new materials, new design concepts and new technologies that later can be used to build more efficient human medical imaging devices. The development of a PET scanner requires expertise on different fields, therefore a consortium was formed that brought together Hungarian academic and industrial partners: the Nuclear Research Institute (which has experience in the development of nuclear detectors and data acquisition systems), the PET Center of the University of Debrecen (which has clinical experience in the application of nuclear imaging devices and background in image processing software), Mediso Ltd. (which has been developing, manufacturing, selling and servicing medical imaging devices since 1990) and other academic partners. This consortium has been working together since 2003: the knowledge base acquired during the development of our small animal PET scanners (miniPET-I and miniPET-II) is now being utilized to build a commercial multimodal human PET scanner. The operation of a PET scanner is based on the simultaneous detection ('coincidence') of two gamma photons originating from a positron annihilation. In traditional PET scanners coincidence is detected by a central unit during the measurement. In our system there is no such central module: all detected single gamma events are recorded (list mode data acquisition), and the list of events are processed using a computer cluster (built from PCs). The usage of independent detector modules and commercial components reduce both development and maintenance costs. Also, this mode of data acquisition is more suitable for development purposes, since once the data is collected and stored it can be used many times to test different signal

  6. Early Detection of Tumor Response by FLT/MicroPET Imaging in a C26 Murine Colon Carcinoma Solid Tumor Animal Model

    Directory of Open Access Journals (Sweden)

    Wan-Chi Lee

    2011-01-01

    Full Text Available Fluorine-18 fluorodeoxyglucose (18F-FDG positron emission tomography (PET imaging demonstrated the change of glucose consumption of tumor cells, but problems with specificity and difficulties in early detection of tumor response to chemotherapy have led to the development of new PET tracers. Fluorine-18-fluorothymidine (18F-FLT images cellular proliferation by entering the salvage pathway of DNA synthesis. In this study, we evaluate the early response of colon carcinoma to the chemotherapeutic drug, lipo-Dox, in C26 murine colorectal carcinoma-bearing mice by 18F-FDG and 18F-FLT. The male BALB/c mice were bilaterally inoculated with 1×105 and 1×106 C26 tumor cells per flank. Mice were intravenously treated with 10 mg/kg lipo-Dox at day 8 after 18F-FDG and 18F-FLT imaging. The biodistribution of 18F-FDG and 18F-FLT were followed by the microPET imaging at day 9. For the quantitative measurement of microPET imaging at day 9, 18F-FLT was superior to 18F-FDG for early detection of tumor response to Lipo-DOX at various tumor sizes (<0.05. The data of biodistribution showed similar results with those from the quantification of SUV (standard uptake value by microPET imaging. The study indicates that 18F-FLT/microPET is a useful imaging modality for early detection of chemotherapy in the colorectal mouse model.

  7. Preparation of ⁶⁸Ga-labelled DOTA-peptides using a manual labelling approach for small-animal PET imaging.

    Science.gov (United States)

    Romero, Eduardo; Martínez, Alfonso; Oteo, Marta; García, Angel; Morcillo, Miguel Angel

    2016-01-01

    (68)Ga-DOTA-peptides are a promising PET radiotracers used in the detection of different tumours types due to their ability for binding specifically receptors overexpressed in these. Furthermore, (68)Ga can be produced by a (68)Ge/(68)Ga generator on site which is a very good alternative to cyclotron-based PET isotopes. Here, we describe a manual labelling approach for the synthesis of (68)Ga-labelled DOTA-peptides based on concentration and purification of the commercial (68)Ga/(68)Ga generator eluate using an anion exchange-cartridge. (68)Ga-DOTA-TATE was used to image a pheochromocytoma xenograft mouse model by a microPET/CT scanner. The method described provides satisfactory results, allowing the subsequent (68)Ga use to label DOTA-peptides. The simplicity of the method along with its implementation reduced cost, makes it useful in preclinical PET studies.

  8. Proton Therapy Verification with PET Imaging

    OpenAIRE

    Zhu, Xuping; Fakhri, Georges El

    2013-01-01

    Proton therapy is very sensitive to uncertainties introduced during treatment planning and dose delivery. PET imaging of proton induced positron emitter distributions is the only practical approach for in vivo, in situ verification of proton therapy. This article reviews the current status of proton therapy verification with PET imaging. The different data detecting systems (in-beam, in-room and off-line PET), calculation methods for the prediction of proton induced PET activity distributions...

  9. Construction and tests of demonstrator modules for a 3-D axial PET system for brain or small animal imaging

    CERN Document Server

    Chesi, E; Clinthorne, N; Pauss, P; Meddi, F; Beltrame, P; Kagan, H; Braem, A; Casella, C; Djambazov, G; Smith, S; Johnson, I; Lustermann, W; Weilhammer, P; Nessi-Tedaldi, F; Dissertori, G; Renker, D; Schneider, T; Schinzel, D; Honscheid, K; De Leo, R; Bolle, E; Fanti, V; Rafecas, M; Cochran, E; Rudge, A; Stapnes, S; Huh, S; Seguinot, J; Solevi, P; Joram, C; Oliver, J F

    2011-01-01

    The design and construction of a PET camera module with high sensitivity, full 3-D spatial reconstruction and very good energy resolution is presented. The basic principle consists of an axial arrangement of long scintillation crystals around the Field Of View (FOV), providing a measurement of the transverse coordinates of the interacting 511 keV gamma ray. On top of each layer of crystals, an array of Wave-Length Shifter (WLS) strips, which collect the light leaving the crystals sideways, is positioned orthogonal to the crystal direction. The signals in the WLS strips allow a precise measurement of the z (axial) co-ordinate of the 511 keV gamma-ray gamma impact. The construction of two modules used for demonstration of the concept is described. First preliminary results on spatial and energy resolution from one full module will be shown. (C) 2010 Elsevier B.V. All rights reserved.

  10. Construction and tests of demonstrator modules for a 3-D axial PET system for brain or small animal imaging

    International Nuclear Information System (INIS)

    The design and construction of a PET camera module with high sensitivity, full 3-D spatial reconstruction and very good energy resolution is presented. The basic principle consists of an axial arrangement of long scintillation crystals around the Field Of View (FOV), providing a measurement of the transverse coordinates of the interacting 511 keV gamma ray. On top of each layer of crystals, an array of Wave-Length Shifter (WLS) strips, which collect the light leaving the crystals sideways, is positioned orthogonal to the crystal direction. The signals in the WLS strips allow a precise measurement of the z (axial) co-ordinate of the 511 keV γ-ray gamma impact. The construction of two modules used for demonstration of the concept is described. First preliminary results on spatial and energy resolution from one full module will be shown.

  11. The Power of Pets: How Animals Affect Family Relationships

    OpenAIRE

    Geller, Krista Scott

    2002-01-01

    THE POWER OF PETS: HOW ANIMALS AFFECT FAMILY RELATIONSHIPS By Krista Scott Geller Katherine R. Allen, Committee Chair Department of Human Development Virginia polytechnic Institute and State University (ABSTRACT) This study was designed to explore the importance a pet can have on someoneâ s life, including ways a pet affects the relationships an individual has with other family members. This study assessed how pets can be influential in peopleâ s lives, espe...

  12. Molecular Imaging Challenges With PET

    CERN Document Server

    Lecoq, P

    2010-01-01

    The future trends in molecular imaging and associated challenges for in-vivo functional imaging are illustrated on the basis of a few examples, such as atherosclerosis vulnerable plaques imaging or stem cells tracking. A set of parameters are derived to define the specifications of a new generation of in-vivo imaging devices in terms of sensitivity, spatial resolution and signal-to-noise ratio. The limitations of strategies used in present PET scanners are discussed and new approaches are proposed taking advantage of recent progress on materials, photodetectors and readout electronics. A special focus is put on metamaterials, as a new approach to bring more functionality to detection devices. It is shown that the route is now open towards a fully digital detector head with very high photon counting capability over a large energy range, excellent timing precision and possibility of imaging the energy deposition process.

  13. Small-animal PET imaging of amyloid-beta plaques with [11C]PiB and its multi-modal validation in an APP/PS1 mouse model of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    André Manook

    Full Text Available In vivo imaging and quantification of amyloid-β plaque (Aβ burden in small-animal models of Alzheimer's disease (AD is a valuable tool for translational research such as developing specific imaging markers and monitoring new therapy approaches. Methodological constraints such as image resolution of positron emission tomography (PET and lack of suitable AD models have limited the feasibility of PET in mice. In this study, we evaluated a feasible protocol for PET imaging of Aβ in mouse brain with [(11C]PiB and specific activities commonly used in human studies. In vivo mouse brain MRI for anatomical reference was acquired with a clinical 1.5 T system. A recently characterized APP/PS1 mouse was employed to measure Aβ at different disease stages in homozygous and hemizygous animals. We performed multi-modal cross-validations for the PET results with ex vivo and in vitro methodologies, including regional brain biodistribution, multi-label digital autoradiography, protein quantification with ELISA, fluorescence microscopy, semi-automated histological quantification and radioligand binding assays. Specific [(11C]PiB uptake in individual brain regions with Aβ deposition was demonstrated and validated in all animals of the study cohort including homozygous AD animals as young as nine months. Corresponding to the extent of Aβ pathology, old homozygous AD animals (21 months showed the highest uptake followed by old hemizygous (23 months and young homozygous mice (9 months. In all AD age groups the cerebellum was shown to be suitable as an intracerebral reference region. PET results were cross-validated and consistent with all applied ex vivo and in vitro methodologies. The results confirm that the experimental setup for non-invasive [(11C]PiB imaging of Aβ in the APP/PS1 mice provides a feasible, reproducible and robust protocol for small-animalimaging. It allows longitudinal imaging studies with follow-up periods of approximately one and a

  14. Studies oriented to optimize the image quality of the small animal PET: Clear PET, modifying some of the parameters of the reconstruction algorithm IMF-OSEM 3D on the data acquisition simulated with GAMOS; Estudios para la optimizaciOn de la calidad de imagen en el escaner ClearPET, modifi cando parametros del algoritmo IMF-OSEM 3D sobre adquisiciones simuladas con GAMOS

    Energy Technology Data Exchange (ETDEWEB)

    Canadas, M.; Mendoza, J.; Embid, M.

    2007-09-27

    This report presents studies oriented to optimize the image quality of the small animal PET: Clear- PET. Certain figures of merit (FOM) were used to assess a quantitative value of the contrast and delectability of lesions. The optimization was carried out modifying some of the parameters in the reconstruction software of the scanner, imaging a mini-Derenzo phantom and a cylinder phantom with background activity and two hot spheres. Specifically, it was evaluated the incidence of the inter-update Metz filter (IMF) inside the iterative reconstruction algorithm 3D OSEM. The data acquisition was simulated using the GAMOS framework (Monte Carlo simulation). Integrating GAMOS output with the reconstruction software of the scanner was an additional novelty of this work, to achieve this, data sets were written with the list-mode format (LMF) of ClearPET. In order to verify the optimum values obtained, we foresee to make real acquisitions in the ClearPET of CIEMAT. (Author) 17 refs.

  15. Radiosynthesis and evaluation of [{sup 61}Cu]-9,10-phenanthrenequinone thiosemicarbazone in fibrosarcoma-bearing animals for PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Jalilian, A.R.; Akhlaghi, M.; Kamali-Dehghan, M.; Shafaii, K.; Moradkhani, S. [Agricultural, Medical and Industrial Research School (AMIRS-NSTRI), Karaj (Iran); Emami, A. [Islamic Azad University, Tehran (Iran). Pharmaceutical Sciences Branch

    2010-07-01

    [{sup 61}Cu]-9,10-Phenanthrenequinone thiosemicarbazone ({sup 61}Cu-PQTS), a radiolabeled anticancer compound was prepared for malignant tissue imaging studies. Copper-61 was produced via the {sup nat}Zn(p, x){sup 61}Cu nuclear reaction in a 30 MeV cyclotron (150 {mu}A irradiation for 76 min, radionuclidic purity >95%). {sup 61}Cu-PQTS was prepared from in-house synthesized PQTS. Quality control was performed using ITLC. The biodistribution of the tracer was compared to the biodistribution of cationic copper-61 in healthy controls. {sup 61}Cu-PQTS was then administered to fibrosarcoma-bearing mice for biodistribution and co-incidence imaging studies. {sup 61}Cu-PQTS demonstrated significant tumor uptake of 2.1% ID/g and the tumor was clearly visualized in a fibrosarcoma model. (orig.)

  16. Radiosynthesis and evaluation of [61Cu]-9,10-phenanthrenequinone thiosemicarbazone in fibrosarcoma-bearing animals for PET imaging

    International Nuclear Information System (INIS)

    [61Cu]-9,10-Phenanthrenequinone thiosemicarbazone (61Cu-PQTS), a radiolabeled anticancer compound was prepared for malignant tissue imaging studies. Copper-61 was produced via the natZn(p, x)61Cu nuclear reaction in a 30 MeV cyclotron (150 μA irradiation for 76 min, radionuclidic purity >95%). 61Cu-PQTS was prepared from in-house synthesized PQTS. Quality control was performed using ITLC. The biodistribution of the tracer was compared to the biodistribution of cationic copper-61 in healthy controls. 61Cu-PQTS was then administered to fibrosarcoma-bearing mice for biodistribution and co-incidence imaging studies. 61Cu-PQTS demonstrated significant tumor uptake of 2.1% ID/g and the tumor was clearly visualized in a fibrosarcoma model. (orig.)

  17. Animal Models for imaging

    OpenAIRE

    Croft, Barbara Y.

    2002-01-01

    Animal models can be used in the study of disease. This chapter discusses imaging animal models to elucidate the process of human disease. The mouse is used as the primary model. Though this choice simplifies many research choices, it necessitates compromises for in vivo imaging. In the future, we can expect improvements in both animal models and imaging techniques.

  18. Characterization of the Ferrara animal PET scanner

    CERN Document Server

    Di Domenico, G; Damiani, C; Del Guerra, A; Gilardi, M C; Motta, A; Zavattini, G

    2002-01-01

    A dedicated small animal PET scanner, YAPPET, was designed and built at Ferrara University. Each detector consists of a 20x20 matrix of 2x2x30 mm sup 3 YAP:Ce finger-like crystals glued together and directly coupled to a Hamamatsu position sensitive photomultiplier. The scanner is made from four detectors positioned on a rotating gantry at a distance of 7.5 cm from the center and the field of view (FOV) is 4 cm both in the transaxial direction and in the axial direction. The system operates in 3D acquisition mode. The performance parameters of YAPPET scanner such as spatial, energy and time resolution, as well as its sensitivity and counting rate have been determined. The average spatial resolution over the whole FOV is 1.8 mm at FWHM and 4.2 mm at FWTM. The sensitivity at the center is 640 cps/mu Ci.

  19. A generalized method of converting CT image to PET linear attenuation coefficient distribution in PET/CT imaging

    International Nuclear Information System (INIS)

    The accuracy of attenuation correction in positron emission tomography scanners depends mainly on deriving the reliable 511-keV linear attenuation coefficient distribution in the scanned objects. In the PET/CT system, the linear attenuation distribution is usually obtained from the intensities of the CT image. However, the intensities of the CT image relate to the attenuation of photons in an energy range of 40 keV–140 keV. Before implementing PET attenuation correction, the intensities of CT images must be transformed into the PET 511-keV linear attenuation coefficients. However, the CT scan parameters can affect the effective energy of CT X-ray photons and thus affect the intensities of the CT image. Therefore, for PET/CT attenuation correction, it is crucial to determine the conversion curve with a given set of CT scan parameters and convert the CT image into a PET linear attenuation coefficient distribution. A generalized method is proposed for converting a CT image into a PET linear attenuation coefficient distribution. Instead of some parameter-dependent phantom calibration experiments, the conversion curve is calculated directly by employing the consistency conditions to yield the most consistent attenuation map with the measured PET data. The method is evaluated with phantom experiments and small animal experiments. In phantom studies, the estimated conversion curve fits the true attenuation coefficients accurately, and accurate PET attenuation maps are obtained by the estimated conversion curves and provide nearly the same correction results as the true attenuation map. In small animal studies, a more complicated attenuation distribution of the mouse is obtained successfully to remove the attenuation artifact and improve the PET image contrast efficiently. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  20. A generalized method of converting CT image to PET linear attenuation coefficient distribution in PET/CT imaging

    Science.gov (United States)

    Wang, Lu; Wu, Li-Wei; Wei, Le; Gao, Juan; Sun, Cui-Li; Chai, Pei; Li, Dao-Wu

    2014-02-01

    The accuracy of attenuation correction in positron emission tomography scanners depends mainly on deriving the reliable 511-keV linear attenuation coefficient distribution in the scanned objects. In the PET/CT system, the linear attenuation distribution is usually obtained from the intensities of the CT image. However, the intensities of the CT image relate to the attenuation of photons in an energy range of 40 keV-140 keV. Before implementing PET attenuation correction, the intensities of CT images must be transformed into the PET 511-keV linear attenuation coefficients. However, the CT scan parameters can affect the effective energy of CT X-ray photons and thus affect the intensities of the CT image. Therefore, for PET/CT attenuation correction, it is crucial to determine the conversion curve with a given set of CT scan parameters and convert the CT image into a PET linear attenuation coefficient distribution. A generalized method is proposed for converting a CT image into a PET linear attenuation coefficient distribution. Instead of some parameter-dependent phantom calibration experiments, the conversion curve is calculated directly by employing the consistency conditions to yield the most consistent attenuation map with the measured PET data. The method is evaluated with phantom experiments and small animal experiments. In phantom studies, the estimated conversion curve fits the true attenuation coefficients accurately, and accurate PET attenuation maps are obtained by the estimated conversion curves and provide nearly the same correction results as the true attenuation map. In small animal studies, a more complicated attenuation distribution of the mouse is obtained successfully to remove the attenuation artifact and improve the PET image contrast efficiently.

  1. Questions and Answers about Ebola, Pets, and Other Animals

    Science.gov (United States)

    ... Questions and Answers about Ebola, Pets, and Other Animals Language: English Español Français Recommend on Facebook Tweet Share Compartir How are animals involved in Ebola outbreaks? Because the natural reservoir ...

  2. Principles of PET/MR Imaging.

    Science.gov (United States)

    Disselhorst, Jonathan A; Bezrukov, Ilja; Kolb, Armin; Parl, Christoph; Pichler, Bernd J

    2014-05-12

    Hybrid PET/MR systems have rapidly progressed from the prototype stage to systems that are increasingly being used in the clinics. This review provides an overview of developments in hybrid PET/MR systems and summarizes the current state of the art in PET/MR instrumentation, correction techniques, and data analysis. The strong magnetic field requires considerable changes in the manner by which PET images are acquired and has led, among others, to the development of new PET detectors, such as silicon photomultipliers. During more than a decade of active PET/MR development, several system designs have been described. The technical background of combined PET/MR systems is explained and related challenges are discussed. The necessity for PET attenuation correction required new methods based on MR data. Therefore, an overview of recent developments in this field is provided. Furthermore, MR-based motion correction techniques for PET are discussed, as integrated PET/MR systems provide a platform for measuring motion with high temporal resolution without additional instrumentation. The MR component in PET/MR systems can provide functional information about disease processes or brain function alongside anatomic images. Against this background, we point out new opportunities for data analysis in this new field of multimodal molecular imaging. PMID:24819419

  3. PET/CT Imaging in Mouse Models of Myocardial Ischemia

    Directory of Open Access Journals (Sweden)

    Sara Gargiulo

    2012-01-01

    Full Text Available Different species have been used to reproduce myocardial infarction models but in the last years mice became the animals of choice for the analysis of several diseases, due to their short life cycle and the possibility of genetic manipulation. Many techniques are currently used for cardiovascular imaging in mice, including X-ray computed tomography (CT, high-resolution ultrasound, magnetic resonance imaging, and nuclear medicine procedures. Cardiac positron emission tomography (PET allows to examine noninvasively, on a molecular level and with high sensitivity, regional changes in myocardial perfusion, metabolism, apoptosis, inflammation, and gene expression or to measure changes in anatomical and functional parameters in heart diseases. Currently hybrid PET/CT scanners for small laboratory animals are available, where CT adds high-resolution anatomical information. This paper reviews mouse models of myocardial infarction and discusses the applications of dedicated PET/CT systems technology, including animal preparation, anesthesia, radiotracers, and images postprocessing.

  4. Proton Therapy Verification with PET Imaging

    Science.gov (United States)

    Zhu, Xuping; Fakhri, Georges El

    2013-01-01

    Proton therapy is very sensitive to uncertainties introduced during treatment planning and dose delivery. PET imaging of proton induced positron emitter distributions is the only practical approach for in vivo, in situ verification of proton therapy. This article reviews the current status of proton therapy verification with PET imaging. The different data detecting systems (in-beam, in-room and off-line PET), calculation methods for the prediction of proton induced PET activity distributions, and approaches for data evaluation are discussed. PMID:24312147

  5. PET imaging using parkinsonian primate model

    International Nuclear Information System (INIS)

    Many animal models have been for studying neutrodegenerative diseases in humans. Among them, Parkinson's disease (PD) model in primates treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is expected to be valid and useful in the field of regenerative medicine. MPTP-treated monkeys demonstrate parkinsonian syndrome, such as tremor, dyskinesia, rigidity, immobility, caused by the degeneration of dopamine neurons at the nigrostriatal pathway. In this model, investigation of cognitive impairment that is one of the important aspects of PD could be possible. We evaluated the degeneration process of nigrostriatal dopamine neurons with positron emission tomography (PET) using unanesthetized MPTP-treated two cynomolgus monkeys (Macaca fascicularis). The tracers used were [11C]PE2I, [11C]DOPA, [11C]raclopride for monitoring dopamine transporter (DAT) densities, dopamine (DA) turnover, dopamine D2-receptor (D2R) densities, respectively. The gross behavioral observation was also performed referring to the criteria of the PD symptoms. The motor dysfunction was not clearly observed up to the cumulative doses of 3 mg/kg MPTP. This period was called 'asymptomatic period'. As a result of PET scans in the asymptomatic period, DAT densities and DA turnover had already decreased greatly, but D2R densities had not changed clearly. These findings suggest that PET imaging can delineate the dopaminergic dysfunction in vivo even in the asymptomatic period. In human study of PD, it is reported that parkinsonism is shown after great loss of dopaminergic neutrons as well as pre-synaptic dysfunction. MPTP-treated monkeys demonstrate the parkinsonian syndrome with the similar mechanism as human PD. It can be expected that PET study with MPTP-monkeys would provide important clues relevant to the underlying cause of PD and be useful for preclinical study of regenerative medicine in this disease. (author)

  6. PET-CT imaging in pediatric oncology

    OpenAIRE

    McCarville, M. Beth

    2009-01-01

    Abstract Positron emission tomography (PET)-computed tomography (CT) is emerging as a valuable tool for assessing a wide variety of pediatric malignancies, including lymphomas, soft-tissue tumors, and bone sarcomas. PET-CT may provide information that is not apparent on conventional imaging performed to stage these diseases and monitor their response to treatment. The use of PET-CT in children requires an awareness of the technical and logistical issues unique to this patient population. In a...

  7. PET imaging of adoptive progenitor cell therapies.

    Energy Technology Data Exchange (ETDEWEB)

    Gelovani, Juri G.

    2008-05-13

    Objectives. The overall objective of this application is to develop novel technologies for non-invasive imaging of adoptive stem cell-based therapies with positron emission tomography (PET) that would be applicable to human patients. To achieve this objective, stem cells will be genetically labeled with a PET-reporter gene and repetitively imaged to assess their distribution, migration, differentiation, and persistence using a radiolabeled reporter probe. This new imaging technology will be tested in adoptive progenitor cell-based therapy models in animals, including: delivery pro-apoptotic genes to tumors, and T-cell reconstitution for immunostimulatory therapy during allogeneic bone marrow progenitor cell transplantation. Technical and Scientific Merits. Non-invasive whole body imaging would significantly aid in the development and clinical implementation of various adoptive progenitor cell-based therapies by providing the means for non-invasive monitoring of the fate of injected progenitor cells over a long period of observation. The proposed imaging approaches could help to address several questions related to stem cell migration and homing, their long-term viability, and their subsequent differentiation. The ability to image these processes non-invasively in 3D and repetitively over a long period of time is very important and will help the development and clinical application of various strategies to control and direct stem cell migration and differentiation. Approach to accomplish the work. Stem cells will be genetically with a reporter gene which will allow for repetitive non-invasive “tracking” of the migration and localization of genetically labeled stem cells and their progeny. This is a radically new approach that is being developed for future human applications and should allow for a long term (many years) repetitive imaging of the fate of tissues that develop from the transplanted stem cells. Why the approach is appropriate. The novel approach to

  8. PET imaging of adoptive progenitor cell therapies

    International Nuclear Information System (INIS)

    The overall objective of this application is to develop novel technologies for non-invasive imaging of adoptive stem cell-based therapies with positron emission tomography (PET) that would be applicable to human patients. To achieve this objective, stem cells will be genetically labeled with a PET-reporter gene and repetitively imaged to assess their distribution, migration, differentiation, and persistence using a radiolabeled reporter probe. This new imaging technology will be tested in adoptive progenitor cell-based therapy models in animals, including: delivery pro-apoptotic genes to tumors, and T-cell reconstitution for immunostimulatory therapy during allogeneic bone marrow progenitor cell transplantation. Technical and Scientific Merits. Non-invasive whole body imaging would significantly aid in the development and clinical implementation of various adoptive progenitor cell-based therapies by providing the means for non-invasive monitoring of the fate of injected progenitor cells over a long period of observation. The proposed imaging approaches could help to address several questions related to stem cell migration and homing, their long-term viability, and their subsequent differentiation. The ability to image these processes non-invasively in 3D and repetitively over a long period of time is very important and will help the development and clinical application of various strategies to control and direct stem cell migration and differentiation. Approach to accomplish the work. Stem cells will be genetically with a reporter gene which will allow for repetitive non-invasive 'tracking' of the migration and localization of genetically labeled stem cells and their progeny. This is a radically new approach that is being developed for future human applications and should allow for a long term (many years) repetitive imaging of the fate of tissues that develop from the transplanted stem cells. Why the approach is appropriate. The novel approach to stem cell imaging

  9. Ready for prime time? Dual tracer PET and SPECT imaging

    Science.gov (United States)

    Fakhri, Georges El

    2012-01-01

    Dual isotope single photon emission computed tomography (SPECT) and dual tracer positron emission tomography (PET) imaging have great potential in clinical and molecular applications in the pediatric as well as the adult populations in many areas of brain, cardiac, and oncologic imaging as it allows the exploration of different physiological and molecular functions (e.g., perfusion, neurotransmission, metabolism, apoptosis, angiogenesis) under the same physiological and physical conditions. This is crucial when the physiological functions studied depend on each other (e.g., perfusion and metabolism) hence requiring simultaneous assessment under identical conditions, and can reduce greatly the quantitation errors associated with physical factors that can change between acquisitions (e.g., human subject or animal motion, change in the attenuation map as a function of time) as is detailed in this editorial. The clinical potential of simultaneous dual isotope SPECT, dual tracer PET and dual SPECT/PET imaging are explored and summarized. In this issue of AJNMMI (http://www.ajnmmi.us), Chapman et al. explore the feasibility of simultaneous and sequential SPECT/PET imaging and conclude that down-scatter and crosstalk from 511 keV photons preclude obtaining useful SPECT information in the presence of PET radiotracers. They report on an alternative strategy that consists of performing sequential SPECT and PET studies in hybrid microPET/SPECT/CT scanners, now widely available for molecular imaging. They validate their approach in a phantom consisting of a 96-well plate with variable 99mTc and 18F concentrations and illustrate the utility of such approaches in two sequential SPECT-PET/CT studies that include 99mTc-MAA/18F-NaF and 99mTc-Pentetate/18F-NaF. These approaches will need to be proven reproducible, accurate and robust to variations in the experimental conditions before they can be accepted by the molecular imaging community and be implemented in routine molecular

  10. Quantitative Techniques in PET-CT Imaging

    NARCIS (Netherlands)

    Basu, Sandip; Zaidi, Habib; Holm, Soren; Alavi, Abass

    2011-01-01

    The appearance of hybrid PET/CT scanners has made quantitative whole body scanning of radioactive tracers feasible. This paper deals with the novel concepts for assessing global organ function and disease activity based on combined functional (PET) and structural (CT or MR) imaging techniques, their

  11. A Review of Cancer Chemotherapy for Pet Animals

    OpenAIRE

    Norris, A. M.; Withrow, S.J.

    1984-01-01

    A review of the principles of cancer chemotherapy for pet animals is presented. The various pharmacological classes of antineoplastic drugs are described with specific references to those drugs that have been widely used in veterinary medicine.

  12. FDG-PET imaging in hematological malignancies.

    Science.gov (United States)

    Valls, L; Badve, C; Avril, S; Herrmann, K; Faulhaber, P; O'Donnell, J; Avril, N

    2016-07-01

    The majority of aggressive lymphomas is characterized by an up regulated glycolytic activity, which enables the visualization by F-18 FDG-PET/CT. One-stop hybrid FDG-PET/CT combines the functional and morphologic information, outperforming both, CT and FDG-PET as separate imaging modalities. This has resulted in several recommendations using FDG-PET/CT for staging, restaging, monitoring during therapy, and assessment of treatment response as well as identification of malignant transformation. FDG-PET/CT may obviate the need for a bone marrow biopsy in patients with Hodgkin's lymphoma and diffuse large B cell lymphoma. FDG-PET/CT response assessment is recommended for FDG-avid lymphomas, whereas CT-based response evaluation remains important in lymphomas with low or variable FDG avidity. The treatment induced change in metabolic activity allows for assessment of response after completion of therapy as well as prediction of outcome early during therapy. The five-point scale Deauville Criteria allows the assessment of treatment response based on visual FDG-PET analysis. Although the use of FDG-PET/CT for prediction of therapeutic response is promising it should only be conducted in the context of clinical trials. Surveillance FDG-PET/CT after complete remission is discouraged due to the relative high number of false-positive findings, which in turn may result in further unnecessary investigations. Future directions include the use of new PET tracers such as F-18 fluorothymidine (FLT), a surrogate biomarker of cellular proliferation and Ga-68 CXCR4, a chemokine receptor imaging biomarker as well as innovative digital PET/CT and PET/MRI techniques. PMID:27090170

  13. 15 CFR 265.43 - Pets and other animals.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Pets and other animals. 265.43 Section... animals. Except in connection with the conduct of official business on the site or with the approval of... person shall bring upon the site any cat, dog, or other animal, provided, however, that blind persons...

  14. 9.4–14.1 T small-animal PET-MR imaging: Feasibility analysis of LYSO APD readout via long signal lines

    Energy Technology Data Exchange (ETDEWEB)

    Neves, J.A., E-mail: janeves@lip.pt [LIP - Laboratory of Instrumentation and Experimental Particle Physics, Lisbon (Portugal); IST-UTL - Instituto Superior Técnico, Technical University of Lisbon, Lisbon (Portugal); Laboratory of Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne (Switzerland); Bugalho, R. [LIP - Laboratory of Instrumentation and Experimental Particle Physics, Lisbon (Portugal); IST-UTL - Instituto Superior Técnico, Technical University of Lisbon, Lisbon (Portugal); Gruetter, R. [Laboratory of Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne (Switzerland); Department of Radiology, University of Lausanne, Lausanne (Switzerland); Department of Radiology, University of Geneva, Geneva (Switzerland); Magill, A.W. [Laboratory of Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne (Switzerland); Department of Radiology, University of Lausanne, Lausanne (Switzerland); Ortigão, C.; Silva, J.C.; Silva, R. [LIP - Laboratory of Instrumentation and Experimental Particle Physics, Lisbon (Portugal); Varela, J. [LIP - Laboratory of Instrumentation and Experimental Particle Physics, Lisbon (Portugal); IST-UTL - Instituto Superior Técnico, Technical University of Lisbon, Lisbon (Portugal); CERN - European Organization for Nuclear Research, Geneva (Switzerland)

    2013-02-21

    In the present work we intend to assess the readout feasibility of Avalanche Photodiode (APD) detectors via long signal lines for the development of a combined small-animal PET-MR prototype based on the ClearPEM technology. The detection performance of a LYSO-APD module was evaluated reading out the APD charge signals to the front-end ASIC via an 80 mm length flexible flat-cable (FFC). Experimental results showed a time resolution of 5.06 ns for the detector module in double-readout mode, with a nonsignificant degradation of 8.4% with the introduction of the FFC. The energy resolution of the system was not degradated by the FFC.

  15. Performance Evaluation of a Small-Animal PET/CT System

    OpenAIRE

    Dahle, Tordis Johnsen

    2014-01-01

    This master project is the first vendor-independent performance evaluation of the new nanoScan PET/CT system at the University of Bergen. A comprehensive performance evaluation of a novel scanner is very important, particularly when quantitative assessments of images are required. The nanoScan PET/CT system is a fully integrated small-animal PET/CT system. An abbreviated performance evaluation of the CT subsystem was done, which included a Hounsfield quality check, a comparison of reconstr...

  16. NEMA NU 4-2008 Comparison of Preclinical PET Imaging Systems

    Science.gov (United States)

    Goertzen, Andrew L.; Bao, Qinan; Bergeron, Mélanie; Blankemeyer, Eric; Blinder, Stephan; Cañadas, Mario; Chatziioannou, Arion F.; Dinelle, Katherine; Elhami, Esmat; Jans, Hans-Sonke; Lage, Eduardo; Lecomte, Roger; Sossi, Vesna; Surti, Suleman; Tai, Yuan-Chuan; Vaquero, Juan José; Vicente, Esther; Williams, Darin A.; Laforest, Richard

    2014-01-01

    The National Electrical Manufacturers Association (NEMA) standard NU 4-2008 for performance measurements of small-animal tomographs was recently published. Before this standard, there were no standard testing procedures for preclinical PET systems, and manufacturers could not provide clear specifications similar to those available for clinical systems under NEMA NU 2-1994 and 2-2001. Consequently, performance evaluation papers used methods that were modified ad hoc from the clinical PET NEMA standard, thus making comparisons between systems difficult. Methods We acquired NEMA NU 4-2008 performance data for a collection of commercial animal PET systems manufactured since 2000: micro- PET P4, microPET R4, microPET Focus 120, microPET Focus 220, Inveon, ClearPET, Mosaic HP, Argus (formerly eXplore Vista), VrPET, LabPET 8, and LabPET 12. The data included spatial resolution, counting-rate performance, scatter fraction, sensitivity, and image quality and were acquired using settings for routine PET. Results The data showed a steady improvement in system performance for newer systems as compared with first-generation systems, with notable improvements in spatial resolution and sensitivity. Conclusion Variation in system design makes direct comparisons between systems from different vendors difficult. When considering the results from NEMA testing, one must also consider the suitability of the PET system for the specific imaging task at hand. PMID:22699999

  17. Small Animal Retinal Imaging

    Science.gov (United States)

    Choi, WooJhon; Drexler, Wolfgang; Fujimoto, James G.

    Developing and validating new techniques and methods for small animal imaging is an important research area because there are many small animal models of retinal diseases such as diabetic retinopathy, age-related macular degeneration, and glaucoma [1-6]. Because the retina is a multilayered structure with distinct abnormalities occurring in different intraretinal layers at different stages of disease progression, there is a need for imaging techniques that enable visualization of these layers individually at different time points. Although postmortem histology and ultrastructural analysis can be performed for investigating microscopic changes in the retina in small animal models, this requires sacrificing animals, which makes repeated assessment of the same animal at different time points impossible and increases the number of animals required. Furthermore, some retinal processes such as neurovascular coupling cannot be fully characterized postmortem.

  18. Whole animal imaging

    OpenAIRE

    Sandhu, Gurpreet Singh; Solorio, Luis; Broome, Ann-Marie; Salem, Nicolas; Kolthammer, Jeff; Shah, Tejas; Flask, Chris; Duerk, Jeffrey L.

    2010-01-01

    Translational research plays a vital role in understanding the underlying pathophysiology of human diseases, and hence development of new diagnostic and therapeutic options for their management. After creating an animal disease model, pathophysiologic changes and effects of a therapeutic intervention on them are often evaluated on the animals using immunohistologic or imaging techniques. In contrast to the immunohistologic techniques, the imaging techniques are noninvasive and hence can be us...

  19. In vivo imaging and characterization of [18F]DPA-714, a potential new TSPO ligand, in mouse brain and peripheral tissues using small-animal PET

    International Nuclear Information System (INIS)

    Introduction: The translocator protein 18 kDa (TSPO), a biochemical marker of neuroinflammation, is highly expressed in the brain activated microglia and it is also expressed by peripheral inflammatory cells and normal peripheral tissues. Thus, development of radioligands for the TSPO may contribute to further understanding the in vivo TSPO function in central and peripheral inflammatory processes and other pathologies. Here, we report the biodistribution, the specific binding and the radiometabolites of [18F]DPA-714, a promising fluorinated PET radiotracer, in normal mice using a microPET/CT scanner. Methods: The in vivo biodistribution and kinetics of [18F]DPA-714 were measured in mice brain and peripheral tissues. Specific binding to TSPO sites was assessed using pharmacological competitive studies by means of saturation experiments performed by i.v. injection of 1 mg/kg of unlabeled DPA-714 or 3 mg/kg of unlabeled PK11195. A region of interest analysis was performed to generate time-activity curves in the brain, heart, lung, kidney, spleen and liver. Metabolites assay was performed in the plasma and peripheral organs by radio-HPLC. Results: [18F]DPA-714 reached high concentration in lung, heart, kidney and spleen, tissues well known to be rich in TSPO sites. [18F]DPA-714 kinetics were faster in the lung and slower in the kidney. Pre-injection of unlabeled DPA-714 or PK11195 inhibited about 80% of [18F]DPA-714 uptake in the lung and heart (p < 0.0005). The percentage of inhibition in the kidney was lower and achieved at later times only with DPA-714 (p < 0.05) but not with PK11195. Sixty minutes after radiotracer injection only unmetabolized radioligand was found in the brain, lung, heart and spleen. Conclusion: These results suggest that [18F]DPA-714 is a suitable PET ligand for imaging in mice brain and peripheral tissues since it binds with high specificity TSPO binding sites and it is almost unchanged at 60 minutes after radiotracer injection in the brain

  20. Imaging quality of (44)Sc in comparison with five other PET radionuclides using Derenzo phantoms and preclinical PET.

    Science.gov (United States)

    Bunka, Maruta; Müller, Cristina; Vermeulen, Christiaan; Haller, Stephanie; Türler, Andreas; Schibli, Roger; van der Meulen, Nicholas P

    2016-04-01

    PET is the favored nuclear imaging technique because of the high sensitivity and resolution it provides, as well as the possibility for quantification of accumulated radioactivity. (44)Sc (T1/2=3.97h, Eβ(+)=632keV) was recently proposed as a potentially interesting radionuclide for PET. The aim of this study was to investigate the image quality, which can be obtained with (44)Sc, and compare it with five other, frequently employed PET nuclides using Derenzo phantoms and a small-animal PET scanner. The radionuclides were produced at the medical cyclotron at CRS, ETH Zurich ((11)C, (18)F), at the Injector II research cyclotron at CRS, PSI ((64)Cu, (89)Zr, (44)Sc), as well as via a generator system ((68)Ga). Derenzo phantoms, containing solutions of each of these radionuclides, were scanned using a GE Healthcare eXplore VISTA small-animal PET scanner. The image resolution was determined for each nuclide by analysis of the intensity signal using the reconstructed PET data of a hole diameter of 1.3mm. The image quality of (44)Sc was compared to five frequently-used PET radionuclides. In agreement with the positron range, an increasing relative resolution was determined in the sequence of (68)Ga<(44)Sc<(89)Zr<(11)C<(64)Cu<(18)F. The performance of (44)Sc was in agreement with the theoretical expectations based on the energy of the emitted positrons. PMID:26774390

  1. Molecular Characterization of Pneumococcal Isolates from Pets and Laboratory Animals

    OpenAIRE

    Mark van der Linden; Adnan Al-Lahham; Werner Nicklas; Ralf René Reinert

    2009-01-01

    BACKGROUND: Between 1986 and 2008 Streptococcus pneumoniae was isolated from 41 pets/zoo animals (guinea pigs (n = 17), cats (n = 12), horses (n = 4), dogs (n = 3), dolphins (n = 2), rat (n = 2), gorilla (n = 1)) treated in medical veterinary laboratories and zoos, and 44 laboratory animals (mastomys (multimammate mice; n = 32), mice (n = 6), rats (n = 4), guinea pigs (n = 2)) during routine health monitoring in an animal facility. S. pneumoniae was isolated from nose, lung and respiratory tr...

  2. PET tracer for imaging of neuroendocrine tumors

    DEFF Research Database (Denmark)

    2013-01-01

    There is provided a radiolabelled peptide-based compound for diagnostic imaging using positron emission tomography (PET). The compound may thus be used for diagnosis of malignant diseases. The compound is particularly useful for imaging of somatostatin overexpression in tumors, wherein the compound...

  3. Ga-68-DOTATOC: Feasibility of high throughput screening by small animal PET using a clinical high-resolution PET/CT scanner

    International Nuclear Information System (INIS)

    As radio peptide tracers have been developed in recent years for the high sensitive detection of neuroendocrine tumors, still the broad application of other peptides to breast and prostate cancer is missing. A rapid screening of new peptides can, in theory, be based on in vivo screening in animals by PET/CT. To test this hypothesis and to asses the minimum screening time needed per animal, we used the application of Ga-68-DOTATOC PET/CT in rats as test system. The Ga-68-DOTATOC yields in a hot spot imaging with minimal background. To delineate liver and spleen, we performed PET/CT of 10 animals on a SIEMENS Biograph 16 LSO HIGHREZ after intravenous injection of 1.5 MBq Ga-68-DOTATOC per animal. Animals were mounted in an '18 slot' holding device and scanned for a single-bed position. The emission times for the PET scan was varied from 1 to 20 min. The images were assessed first for 'PET only' and afterwards in PET/CT fusion mode. The detection of the two organs was good at emission times down to 1 min in PET/CT fusion mode. In the 'PET only' scans, the liver was clearly to be identified down to 1 min emission in all animals. But the spleen could only be delineated only by 1 min of emission in the PET/CT-fusion mode. In conclusion the screening of 'hot spot' enriching peptides is feasible. 'PET only' is in terms of delineation of small organs by far inferior to PET/CT fusion. If animal tumors are above a diameter of 10 mm small, animal PET/CT using clinical high resolution scanners will enable rapid screening. Even the determination of bio-distributions becomes feasible by using list mode tools. The time for the whole survey of 18 animals including anesthesia, preparation and mounting was approximately 20 min. By use of several holding devices mounted simultaneously, a survey time of less than 1 h for 180 animals can be expected

  4. The significant human-animal bond: Pets with cancer

    Energy Technology Data Exchange (ETDEWEB)

    Weller, R.E.

    1994-03-01

    Veterinarians have responsibilities to both the animal and its owner. In the past several years there has been an increased awareness and concern about human-animal bonds. As a result, we have begun to appreciate the nature, strength, and significance of bonds that develop between humans and companion animals. It is typical for a pet to be perceived as and treated as a member of the family and as a result, animals provide special and beneficial relationships for many years. It is partly because of this role of the pet in promoting human health and happiness that we as veterinarians have an obligation to assist both owner and animal. The mark of the good practitioner concerns not only the ability to diagnose and treat accurately, but also the ability to show understanding and compassionate judgement.

  5. Comparison between Bioluminescent Imaging and Small-animal PET-CT in Xenotransplantation Tumor Model with Luc-expressing Cell%荧光素酶标的人肝癌细胞裸鼠异种移植瘤模型的生物发光成像和PET-CT成像比较

    Institute of Scientific and Technical Information of China (English)

    李小颖; 高凯; 董伟; 张连峰

    2011-01-01

    Objective To establish hepatic carcinoma mouse model with human BEL-7402 cells expressing luciferase and to compare bioluminescence imaging with that by small-animal PET-CT.Method The vector containing luciferase gene was constructed and transfected into human BEL-7402 liver tumor cell line and selected with G418 to obtain stable Luc-expressing clones.5 × l05 cells, constitutively expressing luciferase, were inoculated to liver of BALB/cA-nu through hepatic portal vein for assessment of tumor growth with the whole-body optical imaging system and small-animal PET-CT.Result The stable Luc-expressing BEL-7402 cell lines were abtained, which could grow to tumor mass after implantation.There was high uptake of 18 F-FDG at the edge of liver with small-animal PET-CT.Conclusion Luc-labeled BEL-7402 cell lines and a mouse tumor model based on the cell lines are established, the whole-body optical imaging system combined with small-animal PET-CT provides a new and reliable technology for the in situ tumor model, which is a new tool to further study the mechanism of metastasis and drug discovery.%目的 利用荧光素酶基因标记的人肝癌细胞株BEL-7402建立裸鼠肝原位移植模型,及小鼠肝原位移植模型的生物发光和小动物PET-CT成像的比较.方法 构建表达荧光素酶基因的真核表达载体并将其转人人肝癌细胞BEL-7402,经梯度浓度G418筛选获得稳定表达荧光素酶基因的细胞克隆并扩大培养.BALB/cA-nu裸鼠肝门静脉接种5×10(5),个发光细胞使其成瘤,活体荧光成像和小动物PET-CT成像系统观察肿瘤的生长情况.结果 获得了稳定表达Luc的人肝癌细胞株,将其接种到裸鼠体内,活体荧光成像系统观察发现能够成瘤,小动物PET-CT影像观察发现小鼠肝脏边缘对18F-FDG有高摄取区域.结论 利用荧光素酶基因标记的人肝癌细胞BEL7402成功建立了原位肝癌裸鼠模型,小动物活体成像结合小动物PET-CT技术为原位肿瘤模

  6. Cardiac sympathetic neuronal imaging using PET

    Energy Technology Data Exchange (ETDEWEB)

    Lautamaeki, Riikka; Tipre, Dnyanesh [Johns Hopkins University, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Bengel, Frank M. [Johns Hopkins University, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Cardiovascular Nuclear Medicine, Baltimore, MD (United States)

    2007-06-15

    Balance of the autonomic nervous system is essential for adequate cardiac performance, and alterations seem to play a key role in the development and progression of various cardiac diseases. PET imaging of the cardiac autonomic nervous system has advanced extensively in recent years, and multiple pre- and postsynaptic tracers have been introduced. The high spatial and temporal resolution of PET enables noninvasive quantification of neurophysiologic processes at the tissue level. Ligands for catecholamine receptors, along with radiolabeled catecholamines and catecholamine analogs, have been applied to determine involvement of sympathetic dysinnervation at different stages of heart diseases such as ischemia, heart failure, and arrhythmia. This review summarizes the recent findings in neurocardiological PET imaging. Experimental studies with several radioligands and clinical findings in cardiac dysautonomias are discussed. (orig.)

  7. PET imaging in patients with Modic changes

    Energy Technology Data Exchange (ETDEWEB)

    Albert, H.B.; Manniche, C. [Univ. of Southern Denmark, Funen (Denmark). Back Research Centre; Petersen, H.; Hoeilund-Carlsen, P.F. [Odense University Hospital, Univ. of Southern Denmark (Denmark). Dept. of Nuclear Medicine

    2009-07-01

    The aim of this study was via PET imaging to reveal if any highly metabolic processes were occurring in Modic changes type 1 and/or in the adjacent discs. Modic changes (MC) are signal changes in the vertebral endplate and body visualised by magnetic resonance imaging (MRI). MC are strongly associated with low back pain (LBP). MC type 1 appear to be inflammation on MRI, and histological and biochemical findings make it highly likely that an inflammation is present. Though MC is painful no known treatment is available, and it is unknown which entities affect the progress or regress of MC. The changes observed on MRI are slow and take months to develop, but faster changes in the metabolism might provide a platform for monitoring patients. Patients from The Back Centre Funen, with low back pain in the area of L1 to S1, MC type 1 in L1 to L5, and a previous herniated lumbar disc. All patients had a PET scan using FDG ({sup 18}F-fluorodeoxyglucose) as tracer. Included in the study were 11 patients, 4 women and 7 men, mean age 48.1 year (range 20-65). All MC were situated in the vertebrae both above and below the previously herniated disc/discs. Ten patients had MC at 1 level, and 1 had MC at 2 levels. The affected levels were 1 at L2/L3, 6 at L4 /L5, and 5 at L5/S1. All had a previous disc herniation and MC larger than 4 mm in diameter. Technically satisfactory PET scans were obtained. However, PET imaging showed no increases in metabolism in any vertebra or disc of any patient. Modic type 1 changes do not reveal themselves by showing increased metabolism with ordinary FDG PET imaging. PET tracers illuminating inflammation are being developed and hopefully may become more successful. (orig.)

  8. Combined PET/MR imaging in neurology

    DEFF Research Database (Denmark)

    Andersen, Flemming Littrup; Ladefoged, Claes Nøhr; Beyer, Thomas;

    2014-01-01

    AIM: Combined PET/MR systems have now become available for clinical use. Given the lack of integrated standard transmission (TX) sources in these systems, attenuation and scatter correction (AC) must be performed using the available MR-images. Since bone tissue cannot easily be accounted for duri...

  9. LOR-interleaving image reconstruction for PET imaging with fractional-crystal collimation

    Science.gov (United States)

    Li, Yusheng; Matej, Samuel; Karp, Joel S.; Metzler, Scott D.

    2015-01-01

    Positron emission tomography (PET) has become an important modality in medical and molecular imaging. However, in most PET applications, the resolution is still mainly limited by the physical crystal sizes or the detector’s intrinsic spatial resolution. To achieve images with better spatial resolution in a central region of interest (ROI), we have previously proposed using collimation in PET scanners. The collimator is designed to partially mask detector crystals to detect lines of response (LORs) within fractional crystals. A sequence of collimator-encoded LORs is measured with different collimation configurations. This novel collimated scanner geometry makes the reconstruction problem challenging, as both detector and collimator effects need to be modeled to reconstruct high-resolution images from collimated LORs. In this paper, we present a LOR-interleaving (LORI) algorithm, which incorporates these effects and has the advantage of reusing existing reconstruction software, to reconstruct high-resolution images for PET with fractional-crystal collimation. We also develop a 3D ray-tracing model incorporating both the collimator and crystal penetration for simulations and reconstructions of the collimated PET. By registering the collimator-encoded LORs with the collimator configurations, high-resolution LORs are restored based on the modeled transfer matrices using the non-negative least-squares method and EM algorithm. The resolution-enhanced images are then reconstructed from the high-resolution LORs using the MLEM or OSEM algorithm. For validation, we applied the LORI method to a small-animal PET scanner, A-PET, with a specially designed collimator. We demonstrate through simulated reconstructions with a hot-rod phantom and MOBY phantom that the LORI reconstructions can substantially improve spatial resolution and quantification compared to the uncollimated reconstructions. The LORI algorithm is crucial to improve overall image quality of collimated PET, which

  10. PET Imaging - from Physics to Clinical Molecular Imaging

    Science.gov (United States)

    Majewski, Stan

    2008-03-01

    From the beginnings many years ago in a few physics laboratories and first applications as a research brain function imager, PET became lately a leading molecular imaging modality used in diagnosis, staging and therapy monitoring of cancer, as well as has increased use in assessment of brain function (early diagnosis of Alzheimer's, etc) and in cardiac function. To assist with anatomic structure map and with absorption correction CT is often used with PET in a duo system. Growing interest in the last 5-10 years in dedicated organ specific PET imagers (breast, prostate, brain, etc) presents again an opportunity to the particle physics instrumentation community to contribute to the important field of medical imaging. In addition to the bulky standard ring structures, compact, economical and high performance mobile imagers are being proposed and build. The latest development in standard PET imaging is introduction of the well known TOF concept enabling clearer tomographic pictures of the patient organs. Development and availability of novel photodetectors such as Silicon PMT immune to magnetic fields offers an exciting opportunity to use PET in conjunction with MRI and fMRI. As before with avalanche photodiodes, particle physics community plays a leading role in developing these devices. The presentation will mostly focus on present and future opportunities for better PET designs based on new technologies and methods: new scintillators, photodetectors, readout, software.

  11. Denoising of high resolution small animal 3D PET data using the non-subsampled Haar wavelet transform

    Energy Technology Data Exchange (ETDEWEB)

    Ochoa Domínguez, Humberto de Jesús, E-mail: hochoa@uacj.mx [Departamento de Ingeniería Eléctrica y computación, Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chih. (Mexico); Máynez, Leticia O. [Departamento de Ingeniería Eléctrica y computación, Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chih. (Mexico); Vergara Villegas, Osslan O. [Departamento de Ingeniería Industrial, Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chih. (Mexico); Mederos, Boris; Mejía, José M.; Cruz Sánchez, Vianey G. [Departamento de Ingeniería Eléctrica y computación, Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chih. (Mexico)

    2015-06-01

    PET allows functional imaging of the living tissue. However, one of the most serious technical problems affecting the reconstructed data is the noise, particularly in images of small animals. In this paper, a method for high-resolution small animal 3D PET data is proposed with the aim to reduce the noise and preserve details. The method is based on the estimation of the non-subsampled Haar wavelet coefficients by using a linear estimator. The procedure is applied to the volumetric images, reconstructed without correction factors (plane reconstruction). Results show that the method preserves the structures and drastically reduces the noise that contaminates the image.

  12. PET imaging in patients with Modic changes

    DEFF Research Database (Denmark)

    Albert, Hanne; Pedersen, Henrik; Manniche, Claus;

    2009-01-01

    The aim of this study was via PET imaging to reveal if any highly metabolic processes were occurring in Modic changes type 1 and/or in the adjacent discs. Modic changes (MC) are signal changes in the vertebral endplate and body visualised by magnetic resonance imaging (MRI). MC are strongly...... disc. All patients had a PET scan using FDG (18F-fluorodeoxyglucose) as tracer. RESULTS: Included in the study were 11 patients, 4 women and 7 men, mean age 48.1 year (range 20-65). All MC were situated in the vertebrae both above and below the previously herniated disc/discs. Ten patients had MC at 1...... level, and 1 had MC at 2 levels. The affected levels were 1 at L2/L3, 6 at L4 /L5, and 5 at L5/S1. All had a previous disc herniation and MC larger than 4 mm in diameter. Technically satisfactory PET scans were obtained. However, PET imaging showed no increases in metabolism in any vertebra or disc...

  13. Automated analysis of small animal PET studies through deformable registration to an atlas

    International Nuclear Information System (INIS)

    This work aims to develop a methodology for automated atlas-guided analysis of small animal positron emission tomography (PET) data through deformable registration to an anatomical mouse model. A non-rigid registration technique is used to put into correspondence relevant anatomical regions of rodent CT images from combined PET/CT studies to corresponding CT images of the Digimouse anatomical mouse model. The latter provides a pre-segmented atlas consisting of 21 anatomical regions suitable for automated quantitative analysis. Image registration is performed using a package based on the Insight Toolkit allowing the implementation of various image registration algorithms. The optimal parameters obtained for deformable registration were applied to simulated and experimental mouse PET/CT studies. The accuracy of the image registration procedure was assessed by segmenting mouse CT images into seven regions: brain, lungs, heart, kidneys, bladder, skeleton and the rest of the body. This was accomplished prior to image registration using a semi-automated algorithm. Each mouse segmentation was transformed using the parameters obtained during CT to CT image registration. The resulting segmentation was compared with the original Digimouse atlas to quantify image registration accuracy using established metrics such as the Dice coefficient and Hausdorff distance. PET images were then transformed using the same technique and automated quantitative analysis of tracer uptake performed. The Dice coefficient and Hausdorff distance show fair to excellent agreement and a mean registration mismatch distance of about 6 mm. The results demonstrate good quantification accuracy in most of the regions, especially the brain, but not in the bladder, as expected. Normalized mean activity estimates were preserved between the reference and automated quantification techniques with relative errors below 10 % in most of the organs considered. The proposed automated quantification technique is

  14. Automated analysis of small animal PET studies through deformable registration to an atlas

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, Daniel F. [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva 4 (Switzerland); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine and Molecular Imaging, Geneva 4 (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland); University of Groningen, Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands)

    2012-11-15

    This work aims to develop a methodology for automated atlas-guided analysis of small animal positron emission tomography (PET) data through deformable registration to an anatomical mouse model. A non-rigid registration technique is used to put into correspondence relevant anatomical regions of rodent CT images from combined PET/CT studies to corresponding CT images of the Digimouse anatomical mouse model. The latter provides a pre-segmented atlas consisting of 21 anatomical regions suitable for automated quantitative analysis. Image registration is performed using a package based on the Insight Toolkit allowing the implementation of various image registration algorithms. The optimal parameters obtained for deformable registration were applied to simulated and experimental mouse PET/CT studies. The accuracy of the image registration procedure was assessed by segmenting mouse CT images into seven regions: brain, lungs, heart, kidneys, bladder, skeleton and the rest of the body. This was accomplished prior to image registration using a semi-automated algorithm. Each mouse segmentation was transformed using the parameters obtained during CT to CT image registration. The resulting segmentation was compared with the original Digimouse atlas to quantify image registration accuracy using established metrics such as the Dice coefficient and Hausdorff distance. PET images were then transformed using the same technique and automated quantitative analysis of tracer uptake performed. The Dice coefficient and Hausdorff distance show fair to excellent agreement and a mean registration mismatch distance of about 6 mm. The results demonstrate good quantification accuracy in most of the regions, especially the brain, but not in the bladder, as expected. Normalized mean activity estimates were preserved between the reference and automated quantification techniques with relative errors below 10 % in most of the organs considered. The proposed automated quantification technique is

  15. PET Imaging in Huntington’s Disease

    Science.gov (United States)

    Roussakis, Andreas-Antonios; Piccini, Paola

    2015-01-01

    To date, little is known about how neurodegeneration and neuroinflammation propagate in Huntington’s disease (HD). Unfortunately, no treatment is available to cure or reverse the progressive decline of function caused by the disease, thus considering HD a fatal disease. Mutation gene carriers typically remain asymptomatic for many years although alterations in the basal ganglia and cortex occur early on in mutant HD gene–carriers. Positron Emission Tomography (PET) is a functional imaging technique of nuclear medicine which enables in vivo visualization of numerous biological molecules expressed in several human tissues. Brain PET is most powerful to study in vivo neuronal and glial cells function as well as cerebral blood flow in a plethora of neurodegenerative disorders including Parkinson’s disease, Alzheimer’s and HD. In absence of HD–specific biomarkers for monitoring disease progression, previous PET studies in HD were merely focused on the study of dopaminergic terminals, cerebral blood flow and glucose metabolism in manifest and premanifest HD–gene carriers. More recently, research interest has been exploring novel PET targets in HD including the state of phosphodiesterse expression and the role of activated microglia. Hence, a better understanding of the HD pathogenesis mechanisms may lead to the development of targeted therapies. PET imaging follow–up studies with novel selective PET radiotracers such as 11C-IMA–107 and 11C-PBR28 may provide insight on disease progression and identify prognostic biomarkers, elucidate the underlying HD pathology and assess novel pharmaceutical agents and over time. PMID:26683130

  16. Molecular imaging of prostate cancer with PET.

    Science.gov (United States)

    Jadvar, Hossein

    2013-10-01

    Molecular imaging is paving the way for precision and personalized medicine. In view of the significant biologic and clinical heterogeneity of prostate cancer, molecular imaging is expected to play an important role in the evaluation of this prevalent disease. The natural history of prostate cancer spans from an indolent localized process to biochemical relapse after radical treatment with curative intent to a lethal castrate-resistant metastatic disease. The ongoing unraveling of the complex tumor biology of prostate cancer uniquely positions molecular imaging with PET to contribute significantly to every clinical phase of prostate cancer evaluation. The purpose of this article was to provide a concise review of the current state of affairs and potential future developments in the diagnostic utility of PET in prostate cancer.

  17. Energy dependence of scatter components in multispectral PET imaging

    International Nuclear Information System (INIS)

    High resolution images in PET based on small individual detectors are obtained at the cost of low sensitivity and increased detector scatter. These limitations can be partially overcome by enlarging discrimination windows to include more low-energy events and by developing more efficient energy-dependent methods to correct for scatter radiation from all sources. The feasibility of multispectral scatter correction was assessed by decomposing response functions acquired in multiple energy windows into four basic components: object, collimator and detector scatter, and trues. The shape and intensity of these components are different and energy-dependent. They are shown to contribute to image formation in three ways: useful (true), potentially useful (detector scatter), and undesirable (object and collimator scatter) information to the image over the entire energy range. With the Sherbrooke animal PET system, restoration of detector scatter in every energy window would allow nearly 90% of all detected events to participate in image formation. These observations suggest that multispectral acquisition is a promising solution for increasing sensitivity in high resolution PET. This can be achieved without loss of image quality if energy-dependent methods are made available to preserve useful events as potentially useful events are restored and undesirable events removed

  18. PET image reconstruction: mean, variance, and optimal minimax criterion

    Science.gov (United States)

    Liu, Huafeng; Gao, Fei; Guo, Min; Xue, Liying; Nie, Jing; Shi, Pengcheng

    2015-04-01

    Given the noise nature of positron emission tomography (PET) measurements, it is critical to know the image quality and reliability as well as expected radioactivity map (mean image) for both qualitative interpretation and quantitative analysis. While existing efforts have often been devoted to providing only the reconstructed mean image, we present a unified framework for joint estimation of the mean and corresponding variance of the radioactivity map based on an efficient optimal min-max criterion. The proposed framework formulates the PET image reconstruction problem to be a transformation from system uncertainties to estimation errors, where the minimax criterion is adopted to minimize the estimation errors with possibly maximized system uncertainties. The estimation errors, in the form of a covariance matrix, express the measurement uncertainties in a complete way. The framework is then optimized by ∞-norm optimization and solved with the corresponding H∞ filter. Unlike conventional statistical reconstruction algorithms, that rely on the statistical modeling methods of the measurement data or noise, the proposed joint estimation stands from the point of view of signal energies and can handle from imperfect statistical assumptions to even no a priori statistical assumptions. The performance and accuracy of reconstructed mean and variance images are validated using Monte Carlo simulations. Experiments on phantom scans with a small animal PET scanner and real patient scans are also conducted for assessment of clinical potential.

  19. PET imaging clinical trials: standards for good image quality

    International Nuclear Information System (INIS)

    Full text: Imaging holds a promising place in the drug development process and clinical trials. In recent times, scientists and researchers have realized that imaging enables them to look for new surrogate endpoints and accelerate the process of drug development. As the number of such trials is increasing every year, there is a growing awareness for the need of quality in imaging trials, so as to avoid imaging issues, reduce losses due to non-evaluable imaging and improve subject safety. This paper is an attempt to address the need of standards for good quality image in clinical trials which use imaging. The main focus of the paper is to describe the various acquisition options in PET-CT available for medical imaging, their applicability in drug development process and clinical trials, emphasize the need to identify possible sources that could possibly impact the quality of images, ways of standardizing the equipments and minimizing the variability of different scanners. Additionally this paper will look into the importance of an expert medical imaging group, imaging protocols, quality assurance programs, and image assessment post acquisition for technical compliance and image quality. A reference of standards as prescribed by various scientific bodies and organizations will also be reviewed. In this paper the focus will be mainly to discuss aspects of PET-CT imaging in clinical trials. PET-CT has the potential to be best for response monitoring to therapy and early detection of disease compared to all other imaging modalities such as CT, MRI, gamma camera, SPECT, ultrasonography etc. In research, PET imaging can help in understanding the pharmacokinetics of a molecule, i.e. kinetic modeling and provides various imaging options, qualitative and quantitative. PET-CT provides anatomical as well as functional information and has the potential to be highly reproducible. The paper emphasizes good imaging practices and its relevance, especially when we are not just

  20. The research on detector sensitivity of full-coverage animal PET system

    International Nuclear Information System (INIS)

    In order to improve detector sensitivity of small animal PET system and increase geometry angle coverage rate of detector, a full-coverage animal PET system design is proposed, in which two square detectors are added to the original circular PET scanner's both ends. There is a hole in the middle of each of the two square detectors. To investigate the detector sensitivity performance of the new system, GATE was used to build system model and simulation was performed with three different types of radioactive sources which is point, plane and volume sources. The simulation results demonstrate that the change to the detector structure effectively increase the detector sensitivity, and the number of line of responses (LOR) is doubled more than before which will potentially benefit image reconstruction; meanwhile the simulation results of point and plane radioactive sources show that the proposed full-coverage arrangement of detectors improves the uniformity of sensitivity in the FOV, however the hole on the board detector weakens the improvement of detector sensitivity, especially to the radioactive source which is put on the edge of the FOV. Full-coverage animal PET system as proposed can improve detector sensitivity and image quality. (authors)

  1. PET imaging in pediatric Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Advances in diagnostic imaging technology, especially functional imaging modalities like positron emission tomography (PET), have significantly influenced the staging and treatment approaches used for pediatric Hodgkin's lymphoma. Today, the majority of children and adolescents diagnosed with Hodgkin's lymphoma will be cured following treatment with noncross-resistant combination chemotherapy alone or in combination with low-dose, involved-field radiation. This success produced a greater appreciation of long-term complications related to radiation, chemotherapy, and surgical staging that prompted significant changes in staging and treatment protocols for children and adolescents with Hodgkin's lymphoma. Contemporary treatment for pediatric Hodgkin's lymphoma uses a risk-adapted approach that reduces the number of combination chemotherapy cycles and radiation treatment fields and doses for patients with localized favorable disease presentation. Advances in diagnostic imaging technology have played a critical role in the development of these risk-adapted treatment regimens. The introduction of computed tomography (CT) provided an accurate and non-invasive modality to define nodal involvement below the diaphragm that motivated the change from surgical to clinical staging. The introduction of functional imaging modalities, like positron emission tomography (PET) scanning, provided the means to correlate tumor activity with anatomic features generated by CT and modify treatment based on tumor response. For centers with access to this modality, PET imaging plays an important role in staging, evaluating tumor response, planning radiation treatment fields, and monitoring after completion of therapy for pediatric Hodgkin's lymphoma. (orig.)

  2. Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jin Ho; Choi, Yong, E-mail: ychoi.image@gmail.com; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun [Department of Electronic Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 121-742 (Korea, Republic of); Oh, Chang Hyun; Park, Hyun-wook [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Kyung Min; Kim, Jong Guk [Korea Institute of Radiological and Medical Science, 75 Nowon-ro, Nowon-gu, Seoul 139-709 (Korea, Republic of)

    2015-05-15

    Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

  3. Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

    International Nuclear Information System (INIS)

    Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

  4. PET imaging in pediatric neuroradiology: current and future applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sunhee [Children' s Hospital of Pittsburgh of UPMC, Department of Radiology, Pittsburgh, PA (United States); Salamon, Noriko [UCLA David Geffen School of Medicine at UCLA, Department of Radiology, Ronald Reagan UCLA Medical Center, Los Angeles, CA (United States); Jackson, Hollie A.; Blueml, Stefan [Keck School of Medicine of USC, Department of Radiology, Childrens Hospital Los Angeles, Los Angeles, CA (United States); Panigrahy, Ashok [Children' s Hospital of Pittsburgh of UPMC, Department of Radiology, Pittsburgh, PA (United States); Keck School of Medicine of USC, Department of Radiology, Childrens Hospital Los Angeles, Los Angeles, CA (United States)

    2010-01-15

    Molecular imaging with positron emitting tomography (PET) is widely accepted as an essential part of the diagnosis and evaluation of neoplastic and non-neoplastic disease processes. PET has expanded its role from the research domain into clinical application for oncology, cardiology and neuropsychiatry. More recently, PET is being used as a clinical molecular imaging tool in pediatric neuroimaging. PET is considered an accurate and noninvasive method to study brain activity and to understand pediatric neurological disease processes. In this review, specific examples of the clinical use of PET are given with respect to pediatric neuroimaging. The current use of co-registration of PET with MR imaging is exemplified in regard to pediatric epilepsy. The current use of PET/CT in the evaluation of head and neck lymphoma and pediatric brain tumors is also reviewed. Emerging technologies including PET/MRI and neuroreceptor imaging are discussed. (orig.)

  5. [¹⁸F]-fluorodeoxyglucose PET imaging of atherosclerosis

    DEFF Research Database (Denmark)

    Blomberg, Björn Alexander; Høilund-Carlsen, Poul Flemming

    2015-01-01

    [(18)F]-fluorodeoxyglucose PET ((18)FDG PET) imaging has emerged as a promising tool for assessment of atherosclerosis. By targeting atherosclerotic plaque glycolysis, a marker for plaque inflammation and hypoxia, (18)FDG PET can assess plaque vulnerability and potentially predict risk of atheros......[(18)F]-fluorodeoxyglucose PET ((18)FDG PET) imaging has emerged as a promising tool for assessment of atherosclerosis. By targeting atherosclerotic plaque glycolysis, a marker for plaque inflammation and hypoxia, (18)FDG PET can assess plaque vulnerability and potentially predict risk...... of atherosclerosis-related disease, such as stroke and myocardial infarction. With excellent reproducibility, (18)FDG PET can be a surrogate end point in clinical drug trials, improving trial efficiency. This article summarizes key findings in the literature, discusses limitations of (18)FDG PET imaging...... of atherosclerosis, and reports recommendations to optimize imaging protocols....

  6. Pet Face: Mechanisms Underlying Human-Animal Relationships

    OpenAIRE

    Borgi, Marta; Cirulli, Francesca

    2016-01-01

    Accumulating behavioral and neurophysiological studies support the idea of infantile (cute) faces as highly biologically relevant stimuli rapidly and unconsciously capturing attention and eliciting positive/affectionate behaviors, including willingness to care. It has been hypothesized that the presence of infantile physical and behavioral features in companion (or pet) animals (i.e., dogs and cats) might form the basis of our attraction to these species. Preliminary evidence has indeed shown...

  7. [11C]PR04.MZ, a promising DAT ligand for low concentration imaging: synthesis, efficient 11C-0-methylation and initial small animal PET studies

    Energy Technology Data Exchange (ETDEWEB)

    Riss, P.J.; Hooker, J.; Alexoff, D.; Kim, Sung-Won; Fowler, J.S.; Roesch, F.

    2009-05-01

    PR04.MZ was designed as a highly selective dopamine transporter inhibitor, derived from natural cocaine. Its binding profile indicates that [{sup 11}C]PR04.MZ may be suited as a PET radioligand for the non-invasive exploration of striatal and extrastriatal DAT populations. As a key feature, its structural design facilitates both, labelling with fluorine-18 at its terminally fluorinated butynyl moiety and carbon-11 at its methyl ester function. The present report concerns the efficient [{sup 11}C]MeI mediated synthesis of [{sup 11}C]PR04.MZ from an O-desmethyl precursor trifluoroacetic acid salt with Rb{sub 2}CO{sub 3} in DMF in up to 95 {+-} 5% labelling yield. A preliminary {mu}PET-experiment demonstrates the reversible, highly specific binding of [{sup 11}C]PR04.MZ in the brain of a male Sprague-Dawley rat.

  8. Performance evaluation of a high-sensitivity large-aperture small-animal PET scanner. ClairvivoPET

    International Nuclear Information System (INIS)

    In this study, we evaluated the performance of a newly commercialized small-animal positron emission tomography (PET) scanner, ClairvivoPET, which provides significant advantages in spatial resolution, sensitivity, and quantitative accuracy. This scanner consists of depth of interaction detector modules with a large axial extent of 151 mm and an external 137Cs source for attenuation correction. Physical performances, resolution, sensitivity, scatter fraction (SF), counting rate including noise equivalent count (NEC) rate, quantitative accuracy versus activity strength, and transmission accuracy, were measured and evaluated. Animal studies were also performed. Transaxial spatial resolution, measured with a capillary tube, was 1.54 mm at the center and 2.93 mm at a radial offset of 40 mm. The absolute sensitivity was 8.2% at the center, and SFs for mouse- and rat-sized phantoms were 10.7% and 24.2%, respectively. Peak NEC rates for mouse- and rat-sized uniform cylindrical phantoms were 328 kcps at 173 kBq/ml and 119 kcps at 49 kBq/ml, respectively. The quantitative stability of emission counts against activity strength was within 2% over 5 half-lives, ranging from 0.6 MBq to 30 MBq. Transmission measurement based on segmented attenuation correction allowed 6-min and 10-min scans for mouse- and rat-sized cylindrical phantoms, respectively. Rat imaging injected with 18F-NaF resulted in visibility of fine bone structures, and mouse imaging injected with 18F-D-fluoromethyl tyrosine demonstrated the feasibility of using this system to obtain simultaneous time activity curves from separate regions, such as for the heart and tumors. ClairvivoPET is well suited to quantitative imaging even with short scan times, and will provide a number of advantages in new drug development and for kinetic measurement in molecular imaging. (author)

  9. An image quality approach for optimizing {sup 124}I PET imaging on Siemens Inveon PET Scanner

    Energy Technology Data Exchange (ETDEWEB)

    Yu, A Ram; Kim, Jin Su; An, Gwang Il; Woo, Sang Keun; Kim, Jong Guk; Park, Ji Ae; Cheon, Gi Jeong; Kim, Byeong Il; Choi, Chang Woon; Lim, Sang Moo; Kim, Kyeong Min [Korea Institute Radiological and Medical Science, Seoul (Korea, Republic of); Kim, Hee Joung [College of Health Science, Yonsei University, Wonju (Korea, Republic of)

    2010-10-15

    {sup 124}I has a long half life of 4.2 days that is suitable for imaging over several days during the biological uptake and washout of radioiodine. However {sup 124}I has a low positron branching ratio (23%). High-energy {gamma}- photons (602 keV to 1,326 keV) are emitted in cascade with the positrons. These cascade {gamma}- photons degrade the image quality. To find optimal parameter, image quality of the Inveon {sup 124}I PET scanner with various energy window settings was measured based on the NEMA NU4-standars and compared with those of {sup 18}F PET

  10. PET imaging of human cardiac opioid receptors

    International Nuclear Information System (INIS)

    The presence of opioid peptides and receptors and their role in the regulation of cardiovascular function has been previously demonstrated in the mammalian heart. The aim of this study was to image μ and δ opioid receptors in the human heart using positron emission tomography (PET). Five subjects (three females, two males, 65±8 years old) underwent PET scanning of the chest with [11C]carfentanil ([11C]CFN) and [11C]-N-methyl-naltrindole ([11C]MeNTI) and the images were analyzed for evidence of opioid receptor binding in the heart. Either [11C]CFN or [11C]MeNTI (20 mCi) was injected i.v. with subsequent dynamic acquisitions over 90 min. For the blocking studies, either 0.2 mg/kg or 1 mg/kg of naloxone was injected i.v. 5 min prior to the injection of [11C]CFN and [11C]MeNTI, respectively. Regions of interest were placed over the left ventricle, left ventricular chamber, lung and skeletal muscle. Graphical analysis demonstrated average baseline myocardial binding potentials (BP) of 4.37±0.91 with [11C]CFN and 3.86±0.60 with [11C]MeNTI. Administration of 0.2 mg/kg naloxone prior to [11C]CFN produced a 25% reduction in BP in one subject in comparison with baseline values, and a 19% decrease in myocardial distribution volume (DV). Administration of 1 mg/kg of naloxone before [11C]MeNTI in another subject produced a 14% decrease in BP and a 21% decrease in the myocardial DV. These results demonstrate the ability to image these receptors in vivo by PET. PET imaging of cardiac opioid receptors may help to better understand their role in cardiovascular pathophysiology and the effect of abuse of opioids and drugs on heart function. (orig.)

  11. Animal Images and Metaphors in Animal Farm

    OpenAIRE

    Ping Sun

    2015-01-01

    In literary works animal images are frequently used as the “source domain” of a metaphor to disclose the natures of the “target domain”, human beings. This is called “cross-domain mapping” or “conceptual metaphor” in cognitive linguistics, which is based on the similar qualities between animals and human beings. Thus the apparent descriptions of the animals are really the deep revelations of the human beings. Animal Farm is one exemplary product of this special expressing way. Diversified ani...

  12. Animal imaging studies of potential brain damage

    Science.gov (United States)

    Gatley, S. J.; Vazquez, M. E.; Rice, O.

    To date, animal studies have not been able to predict the likelihood of problems in human neurological health due to HZE particle exposure during space missions outside the Earth's magnetosphere. In ongoing studies in mice, we have demonstrated that cocaine stimulated locomotor activity is reduced by a moderate dose (120 cGy) of 1 GeV 56Fe particles. We postulate that imaging experiments in animals may provide more sensitive and earlier indicators of damage due to HZE particles than behavioral tests. Since the small size of the mouse brain is not well suited to the spatial resolution offered by microPET, we are now repeating some of our studies in a rat model. We anticipate that this will enable us to identify imaging correlates of behavioral endpoints. A specific hypothesis of our studies is that changes in the metabolic rate for glucose in striatum of animals will be correlated with alterations in locomotor activity. We will also evaluate whether the neuroprotective drug L-deprenyl reduces the effect of radiation on locomotor activity. In addition, we will conduct microPET studies of brain monoamine oxidase A and monoamine oxidase B in rats before and at various times after irradiation with HZE particles. The hypothesis is that monoamine oxidase A, which is located in nerve terminals, will be unchanged or decreased after irradiation, while monoamine oxidase B, which is located in glial cells, will be increased after irradiation. Neurochemical effects that could be measured using PET could in principle be applied in astronauts, in terms of detecting and monitoring subtle neurological damage that might have occurred during long space missions. More speculative uses of PET are in screening candidates for prolonged space missions (for example, for adequate reserve in critical brain circuits) and in optimizing medications to treat impairments after missions.

  13. BIODISTRIBUTION AND PET IMAGING OF [18F]-FLUOROADENOSINE DERIVATIVES

    Science.gov (United States)

    Alauddin, Mian M.; Shahinian, Antranik; Park, Ryan; Tohme, Michael; Fissekis, John D.; Conti, Peter S.

    2007-01-01

    Introduction: Many fluorinated analogues of adenosine nucleoside have been synthesized and studied as potential antitumor and antiviral agents. Earlier we reported radiosynthesis of 2′-deoxy-2′-[18F]fluoro-1-β-D-arabinofuranosyl-adenine ([18F]-FAA) and 3′-deoxy-3′-[18F]fluoro-1-β-D-xylofuranosyl-adenine ([18F]FXA). Now we report their in vivo studies including blood clearance, biodistribution and micro-PET imaging in tumor-bearing nude mice. Methods: Tumors were grown in six weeks old athymic nude mice (Harlan, Indianapolis, IN) by inoculation of HT-29 cells, wild type cells in the left flank and transduced cells with HSV-tk on the right flank. When the tumor was about 1 cm in size, animals were injected with these radiotracers for in vivo studies, including blood clearance, micro-PET imaging and biodistribution. Results: Uptake of [18F]FAA in tumor was 3.3-fold higher than blood, with highest uptake in the spleen. Maximum uptake of [18F]FXA was observed in the heart compared to other organs. There was no tumor uptake of [18F]FXA. Biodistribution results were supported by micro-PET images, which also showed very high uptake of [18F]FAA in spleen and visualization of tumors, and high uptake of [18F]FXA in the heart. Conclusion: These results suggest that [18F]FAA may be useful for tumor imaging, while [18F]FXA may have potential as a heart imaging agent with PET. PMID:17383576

  14. PET ANIMALS (CATS AND DOGS) OWNERS PROSPECTS FOR THE VETERINARY CLINICS

    OpenAIRE

    DEMİR, Pınar; UĞURLU KOÇ, Aysun

    2014-01-01

    In this study, the views and expectations of pet animal owners were determined for their veterinary clinic. The material of this study was obtained from a survey conducted with the owners of 102 pet animals in Ankara Altinpark. 55.9% of the pet owners, who surveyed, were  female and the average age of pet owners were 34.9±1.28 and having pet animals average 8.2±0.79 years. The study also determined that almost 55% of animal breeders who surveyed feed the cat. The average monthly income of the...

  15. Animal Housing: The Secret Life of Students' Pets Is Not Always a Walk in the Park.

    Science.gov (United States)

    Hoover, Eric

    2003-01-01

    Animals owned by college students are particularly vulnerable to neglect, mistreatment, and abandonment, given the fact that pets are usually prohibited from college dorms and student apartments. Some students, however, persist in keeping pets on campus. (SLD)

  16. Inter-subject MR-PET image registration and integration

    International Nuclear Information System (INIS)

    A MR-PET inter-subject image integration technique is developed to provide more precise anatomical location based on a template MR image, and to examine the anatomical variation in sensory-motor stimulation or to obtain cross-subject signal averaging to enhance the delectability of focal brain activity detected by different subject PET images. In this study, a multimodality intrasubject image registration procedure is firstly applied to align MR and PET images of the same subject. The second procedure is to estimate an elastic image transformation that can nonlinearly deform each 3D brain MR image and map them to the template MR image. The estimation procedure of the elastic image transformation is based on a strategy that searches the best local image match to achieve an optimal global image match, iteratively. The final elastic image transformation estimated for each subject will then be used to deform the MR-PET registered PET image. After the nonlinear PET image deformation, MR-PET intersubject mapping, averaging, and fusing are simultaneously accomplished. The developed technique has been implemented to an UNIX based workstation with Motif window system. The software named Elastic-IRIS has few requirements of user interaction. The registered anatomical location of 10 different subjects has a standard deviation of ∼2mm. in the x, y, and z directions. The processing time for one MR-PET inter-subject registration ranged from 20 to 30 minutes on a SUN SPARC-20

  17. Childhood pet ownership, attachment to pets, and subsequent meat avoidance. The mediating role of empathy toward animals.

    Science.gov (United States)

    Rothgerber, Hank; Mican, Frances

    2014-08-01

    Researchers studying childhood pet ownership outcomes do not typically focus on measures of adult diet, and those studying the psychology of meat consumption do not normally consider early experiences with companion animals. The present research sought to integrate these two areas by examining relationships between childhood pet ownership, pet attachment, empathy toward animals, belief in human-animal similarity, meat avoidance, and justifications for eating meat. Results from 273 individuals responding to a survey on an internet platform revealed that participants with greater childhood attachment to a pet reported greater meat avoidance as adults, an effect that disappeared when controlling for animal empathy. Greater childhood pet attachment was also related to the use of indirect, apologetic justifications for meat consumption, and this effect too, was mediated by empathy toward animals. Child pet ownership itself predicted views toward animals but not dietary behavior or meat-eating justifications. The authors propose a sequence of events by which greater childhood pet attachment leads to increased meat avoidance, focusing on the central role played by empathy toward animals. PMID:24704704

  18. The application of PET imaging in psychoneuroimmunology research.

    Science.gov (United States)

    Hannestad, Jonas

    2012-01-01

    Positron emission tomography (PET) imaging is a research tool that allows in vivo measurements of brain metabolism and specific target molecules. PET imaging can be used to measure these brain variables in a variety of species, including human and non-human primates, and rodents. PET imaging can therefore be combined with various experimental and clinical model systems that are commonly used in psychoneuroimmunology research.

  19. Why Did You Choose This Pet?: Adopters and Pet Selection Preferences in Five Animal Shelters in the United States

    OpenAIRE

    Carla Vela; Heather Mohan-Gibbons; Emily Weiss; Katherine Miller

    2012-01-01

    Simple Summary This study examined reasons why adopters chose their pet in an animal shelter, what behaviors were first exhibited by the pet to the adopter, what information was important during their selection process, and the relative importance of seeing the animals’ behavior in various contexts. Abstract Responses from an adopter survey (n = 1,491) determined reasons for pet selection, type of information received by the adopter, and the context in which the animal’s behavior was observed...

  20. An efficient simulator for pinhole imaging of PET isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Goorden, M C; Van der Have, F; Kreuger, R; Beekman, F J, E-mail: m.c.goorden@tudelft.nl [Section of Radiation Detection and Medical Imaging, Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)

    2011-03-21

    Today, small-animal multi-pinhole single photon emission computed tomography (SPECT) can reach sub-half-millimeter image resolution. Recently we have shown that dedicated multi-pinhole collimators can also image PET tracers at sub-mm level. Simulations play a vital role in the design and optimization of such collimators. Here we propose and validate an efficient simulator that models the whole imaging chain from emitted positron to detector signal. This analytical simulator for pinhole positron emission computed tomography (ASPECT) combines analytical models for pinhole and detector response with Monte Carlo (MC)-generated kernels for positron range. Accuracy of ASPECT was validated by means of a MC simulator (MCS) that uses a kernel-based step for detector response with an angle-dependent detector kernel based on experiments. Digital phantom simulations with ASPECT and MCS converge to almost identical images. However, ASPECT converges to an equal image noise level three to four orders of magnitude faster than MCS. We conclude that ASPECT could serve as a practical tool in collimator design and iterative image reconstruction for novel multi-pinhole PET.

  1. Optimizing modelling in iterative image reconstruction for preclinical pinhole PET

    Science.gov (United States)

    Goorden, Marlies C.; van Roosmalen, Jarno; van der Have, Frans; Beekman, Freek J.

    2016-05-01

    The recently developed versatile emission computed tomography (VECTor) technology enables high-energy SPECT and simultaneous SPECT and PET of small animals at sub-mm resolutions. VECTor uses dedicated clustered pinhole collimators mounted in a scanner with three stationary large-area NaI(Tl) gamma detectors. Here, we develop and validate dedicated image reconstruction methods that compensate for image degradation by incorporating accurate models for the transport of high-energy annihilation gamma photons. Ray tracing software was used to calculate photon transport through the collimator structures and into the gamma detector. Input to this code are several geometric parameters estimated from system calibration with a scanning 99mTc point source. Effects on reconstructed images of (i) modelling variable depth-of-interaction (DOI) in the detector, (ii) incorporating photon paths that go through multiple pinholes (‘multiple-pinhole paths’ (MPP)), and (iii) including various amounts of point spread function (PSF) tail were evaluated. Imaging 18F in resolution and uniformity phantoms showed that including large parts of PSFs is essential to obtain good contrast-noise characteristics and that DOI modelling is highly effective in removing deformations of small structures, together leading to 0.75 mm resolution PET images of a hot-rod Derenzo phantom. Moreover, MPP modelling reduced the level of background noise. These improvements were also clearly visible in mouse images. Performance of VECTor can thus be significantly improved by accurately modelling annihilation gamma photon transport.

  2. PET image reconstruction with rotationally symmetric polygonal pixel grid based highly compressible system matrix

    International Nuclear Information System (INIS)

    To achieve a maximum compression of system matrix in positron emission tomography (PET) image reconstruction, we proposed a polygonal image pixel division strategy in accordance with rotationally symmetric PET geometry. Geometrical definition and indexing rule for polygonal pixels were established. Image conversion from polygonal pixel structure to conventional rectangular pixel structure was implemented using a conversion matrix. A set of test images were analytically defined in polygonal pixel structure, converted to conventional rectangular pixel based images, and correctly displayed which verified the correctness of the image definition, conversion description and conversion of polygonal pixel structure. A compressed system matrix for PET image recon was generated by tap model and tested by forward-projecting three different distributions of radioactive sources to the sinogram domain and comparing them with theoretical predictions. On a practical small animal PET scanner, a compress ratio of 12.6:1 of the system matrix size was achieved with the polygonal pixel structure, comparing with the conventional rectangular pixel based tap-mode one. OS-EM iterative image reconstruction algorithms with the polygonal and conventional Cartesian pixel grid were developed. A hot rod phantom was detected and reconstructed based on these two grids with reasonable time cost. Image resolution of reconstructed images was both 1.35 mm. We conclude that it is feasible to reconstruct and display images in a polygonal image pixel structure based on a compressed system matrix in PET image reconstruction. (authors)

  3. A rat head holder for simultaneous scanning of two rats in small animal PET scanners: Design, construction, feasibility testing and kinetic validation

    OpenAIRE

    Cheng, Tee Ean; Yoder, Karmen K; Normandin, Marc D.; Risacher, Shannon L; Converse, Alexander K; Hampel, Joseph A; Miller, Michael A.; Morris, Evan D

    2008-01-01

    To reduce imaging costs, we designed a head holder for scanning two rats simultaneously in small animal PET scanners. Our goals were (i) to maintain high sensitivity and (ii) to minimize repositioning error between scans.

  4. Choline-PET/CT for imaging prostate cancer; Cholin-PET/CT zur Bildgebung des Prostatakarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Bernd Joachim [Klinik- und Poliklinik fuer Nuklearmedizin, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany); Treiber, U.; Schwarzenboeck, S.; Souvatzoglou, M. [Klinik fuer Urologie, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany)

    2010-09-15

    PET and PET/CT using [{sup 11}C]- and [{sup 18}F]-labelled choline derivatives are increasingly being used for imaging of prostate cancer. The value of PET and PET/CT with [{sup 11}C]- and [{sup 18}F]-labelled choline derivates in biochemical recurrence of prostate cancer has been examined in many studies and demonstrates an increasing importance. Primary prostate cancer can be detected with moderate sensitivity using PET and PET/CT using [{sup 11}C]- and [{sup 18}F]-labelled choline derivatives - the differentiation between benign prostatic hyperplasia, prostatitis or high-grade intraepithelial neoplasia (HGPIN) is not always possible. At the present time [{sup 11}C]choline PET/CT is not recommended in the primary setting but may be utilized in clinically suspected prostate cancer with repeatedly negative prostate biopsies, in preparation of a focused re-biopsy. Promising results have been obtained for the use of PET and PET/CT with [{sup 11}C]- and [{sup 18}F]-labelled choline derivates in patients with biochemical recurrence. The detection rate of choline PET and PET/CT for local, regional, and distant recurrence in patients with a biochemical recurrence shows a linear correlation with PSA values at the time of imaging and reaches about 75% in patients with PSA > 3 ng/mL. At PSA values below 1 ng/mL, the recurrence can be diagnosed with choline PET/CT in approximately 1/3 of the patients. PET and PET/CT with [{sup 11}C]- and [{sup 18}F]choline derivates can be helpful for choosing a therapeutic strategy in the sense of an individualized treatment: since an early diagnosis of recurrence is crucial to the choice of optimal treatment. The localization of the site of recurrence - local recurrence, lymph node metastasis or systemic dissemination - has important influence on the therapy regimen. (orig.)

  5. PET imaging of human cardiac opioid receptors

    Energy Technology Data Exchange (ETDEWEB)

    Villemagne, Patricia S.R.; Dannals, Robert F. [Department of Radiology, The Johns Hopkins University School of Medicine, 605 N Caroline St., Baltimore, Maryland (United States); Department of Environmental Health Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Ravert, Hayden T. [Department of Radiology, The Johns Hopkins University School of Medicine, 605 N Caroline St., Baltimore, Maryland (United States); Frost, James J. [Department of Radiology, The Johns Hopkins University School of Medicine, 605 N Caroline St., Baltimore, Maryland (United States); Department of Environmental Health Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

    2002-10-01

    The presence of opioid peptides and receptors and their role in the regulation of cardiovascular function has been previously demonstrated in the mammalian heart. The aim of this study was to image {mu} and {delta} opioid receptors in the human heart using positron emission tomography (PET). Five subjects (three females, two males, 65{+-}8 years old) underwent PET scanning of the chest with [{sup 11}C]carfentanil ([{sup 11}C]CFN) and [{sup 11}C]-N-methyl-naltrindole ([{sup 11}C]MeNTI) and the images were analyzed for evidence of opioid receptor binding in the heart. Either [{sup 11}C]CFN or [{sup 11}C]MeNTI (20 mCi) was injected i.v. with subsequent dynamic acquisitions over 90 min. For the blocking studies, either 0.2 mg/kg or 1 mg/kg of naloxone was injected i.v. 5 min prior to the injection of [{sup 11}C]CFN and [{sup 11}C]MeNTI, respectively. Regions of interest were placed over the left ventricle, left ventricular chamber, lung and skeletal muscle. Graphical analysis demonstrated average baseline myocardial binding potentials (BP) of 4.37{+-}0.91 with [{sup 11}C]CFN and 3.86{+-}0.60 with [{sup 11}C]MeNTI. Administration of 0.2 mg/kg naloxone prior to [{sup 11}C]CFN produced a 25% reduction in BP in one subject in comparison with baseline values, and a 19% decrease in myocardial distribution volume (DV). Administration of 1 mg/kg of naloxone before [{sup 11}C]MeNTI in another subject produced a 14% decrease in BP and a 21% decrease in the myocardial DV. These results demonstrate the ability to image these receptors in vivo by PET. PET imaging of cardiac opioid receptors may help to better understand their role in cardiovascular pathophysiology and the effect of abuse of opioids and drugs on heart function. (orig.)

  6. Dual-Modality PET/Ultrasound imaging of the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Jennifer S.; Moses, William W.; Pouliot, Jean; Hsu, I.C.

    2005-11-11

    Functional imaging with positron emission tomography (PET)will detect malignant tumors in the prostate and/or prostate bed, as well as possibly help determine tumor ''aggressiveness''. However, the relative uptake in a prostate tumor can be so great that few other anatomical landmarks are visible in a PET image. Ultrasound imaging with a transrectal probe provides anatomical detail in the prostate region that can be co-registered with the sensitive functional information from the PET imaging. Imaging the prostate with both PET and transrectal ultrasound (TRUS) will help determine the location of any cancer within the prostate region. This dual-modality imaging should help provide better detection and treatment of prostate cancer. LBNL has built a high performance positron emission tomograph optimized to image the prostate.Compared to a standard whole-body PET camera, our prostate-optimized PET camera has the same sensitivity and resolution, less backgrounds and lower cost. We plan to develop the hardware and software tools needed for a validated dual PET/TRUS prostate imaging system. We also plan to develop dual prostate imaging with PET and external transabdominal ultrasound, in case the TRUS system is too uncomfortable for some patients. We present the design and intended clinical uses for these dual imaging systems.

  7. Molecular characterization of pneumococcal isolates from pets and laboratory animals.

    Directory of Open Access Journals (Sweden)

    Mark van der Linden

    Full Text Available BACKGROUND: Between 1986 and 2008 Streptococcus pneumoniae was isolated from 41 pets/zoo animals (guinea pigs (n = 17, cats (n = 12, horses (n = 4, dogs (n = 3, dolphins (n = 2, rat (n = 2, gorilla (n = 1 treated in medical veterinary laboratories and zoos, and 44 laboratory animals (mastomys (multimammate mice; n = 32, mice (n = 6, rats (n = 4, guinea pigs (n = 2 during routine health monitoring in an animal facility. S. pneumoniae was isolated from nose, lung and respiratory tract, eye, ear and other sites. METHODOLOGY/PRINCIPAL FINDINGS: Carriage of the same isolate of S. pneumoniae over a period of up to 22 weeks was shown for four mastomys. Forty-one animals showed disease symptoms. Pneumococcal isolates were characterized by optochin sensitivity, bile solubility, DNA hybridization, pneumolysin PCR, serotyping and multilocus sequence typing. Eighteen of the 32 mastomys isolates (56% were optochin resistant, all other isolates were optochin susceptible. All mastomys isolates were serotype 14, all guinea pig isolates serotype 19F, all horse isolates serotype 3. Rats had serotypes 14 or 19A, mice 33A or 33F. Dolphins had serotype 23F, the gorilla serotype 14. Cats and dogs had many different serotypes. Four isolates were resistant to macrolides, three isolates also to clindamycin and tetracycline. Mastomys isolates were sequence type (ST 15 (serotype 14, an ST/serotype combination commonly found in human isolates. Cats, dogs, pet rats, gorilla and dolphins showed various human ST/serotype combinations. Lab rats and lab mice showed single locus variants (SLV of human STs, in human ST/serotype combinations. All guinea pig isolates showed the same completely new combination of known alleles. The horse isolates showed an unknown allele combination and three new alleles. CONCLUSIONS/SIGNIFICANCE: The isolates found in mastomys, mice, rats, cats, dogs, gorilla and dolphins are most likely identical to human pneumococcal isolates. Isolates from

  8. Head and neck imaging with PET and PET/CT: artefacts from dental metallic implants

    International Nuclear Information System (INIS)

    Germanium-68 based attenuation correction (PETGe68) is performed in positron emission tomography (PET) imaging for quantitative measurements. With the recent introduction of combined in-line PET/CT scanners, CT data can be used for attenuation correction. Since dental implants can cause artefacts in CT images, CT-based attenuation correction (PETCT) may induce artefacts in PET images. The purpose of this study was to evaluate the influence of dental metallic artwork on the quality of PET images by comparing non-corrected images and images attenuation corrected by PETGe68 and PETCT. Imaging was performed on a novel in-line PET/CT system using a 40-mAs scan for PETCT in 41 consecutive patients with high suspicion of malignant or inflammatory disease. In 17 patients, additional PETGe68 images were acquired in the same imaging session. Visual analysis of fluorine-18 fluorodeoxyglucose (FDG) distribution in several regions of the head and neck was scored on a 4-point scale in comparison with normal grey matter of the brain in the corresponding PET images. In addition, artefacts adjacent to dental metallic artwork were evaluated. A significant difference in image quality scoring was found only for the lips and the tip of the nose, which appeared darker on non-corrected than on corrected PET images. In 33 patients, artefacts were seen on CT, and in 28 of these patients, artefacts were also seen on PET imaging. In eight patients without implants, artefacts were seen neither on CT nor on PET images. Direct comparison of PETGe68 and PETCT images showed a different appearance of artefacts in 3 of 17 patients. Malignant lesions were equally well visible using both transmission correction methods. Dental implants, non-removable bridgework etc. can cause artefacts in attenuation-corrected images using either a conventional 68Ge transmission source or the CT scan obtained with a combined PET/CT camera. We recommend that the non-attenuation-corrected PET images also be evaluated

  9. Automated image registration for FDOPA PET studies

    Science.gov (United States)

    Lin, Kang-Ping; Huang, Sung-Cheng; Yu, Dan-Chu; Melega, William; Barrio, Jorge R.; Phelps, Michael E.

    1996-12-01

    In this study, various image registration methods are investigated for their suitability for registration of L-6-[18F]-fluoro-DOPA (FDOPA) PET images. Five different optimization criteria including sum of absolute difference (SAD), mean square difference (MSD), cross-correlation coefficient (CC), standard deviation of pixel ratio (SDPR), and stochastic sign change (SSC) were implemented and Powell's algorithm was used to optimize the criteria. The optimization criteria were calculated either unidirectionally (i.e. only evaluating the criteria for comparing the resliced image 1 with the original image 2) or bidirectionally (i.e. averaging the criteria for comparing the resliced image 1 with the original image 2 and those for the sliced image 2 with the original image 1). Monkey FDOPA images taken at various known orientations were used to evaluate the accuracy of different methods. A set of human FDOPA dynamic images was used to investigate the ability of the methods for correcting subject movement. It was found that a large improvement in performance resulted when bidirectional rather than unidirectional criteria were used. Overall, the SAD, MSD and SDPR methods were found to be comparable in performance and were suitable for registering FDOPA images. The MSD method gave more adequate results for frame-to-frame image registration for correcting subject movement during a dynamic FDOPA study. The utility of the registration method is further demonstrated by registering FDOPA images in monkeys before and after amphetamine injection to reveal more clearly the changes in spatial distribution of FDOPA due to the drug intervention.

  10. 78 FR 57227 - Animal Welfare; Retail Pet Stores and Licensing Exemptions

    Science.gov (United States)

    2013-09-18

    ... the definition of retail pet store in the regulations is consistent with the Animal Welfare Act (AWA... INFORMATION: I. Purpose of the Regulatory Action Need for the Regulatory Action The Animal Welfare Act (AWA or... Health Inspection Service 9 CFR Parts 1 and 2 RIN 0579-AD57 Animal Welfare; Retail Pet Stores...

  11. Accuracy and reproducibility of tumor positioning during prolonged and multi-modality animal imaging studies

    Science.gov (United States)

    Zhang, Mutian; Huang, Minming; Le, Carl; Zanzonico, Pat B.; Claus, Filip; Kolbert, Katherine S.; Martin, Kyle; Ling, C. Clifton; Koutcher, Jason A.; Humm, John L.

    2008-10-01

    Dedicated small-animal imaging devices, e.g. positron emission tomography (PET), computed tomography (CT) and magnetic resonance imaging (MRI) scanners, are being increasingly used for translational molecular imaging studies. The objective of this work was to determine the positional accuracy and precision with which tumors in situ can be reliably and reproducibly imaged on dedicated small-animal imaging equipment. We designed, fabricated and tested a custom rodent cradle with a stereotactic template to facilitate registration among image sets. To quantify tumor motion during our small-animal imaging protocols, 'gold standard' multi-modality point markers were inserted into tumor masses on the hind limbs of rats. Three types of imaging examination were then performed with the animals continuously anesthetized and immobilized: (i) consecutive microPET and MR images of tumor xenografts in which the animals remained in the same scanner for 2 h duration, (ii) multi-modality imaging studies in which the animals were transported between distant imaging devices and (iii) serial microPET scans in which the animals were repositioned in the same scanner for subsequent images. Our results showed that the animal tumor moved by less than 0.2-0.3 mm over a continuous 2 h microPET or MR imaging session. The process of transporting the animal between instruments introduced additional errors of ~0.2 mm. In serial animal imaging studies, the positioning reproducibility within ~0.8 mm could be obtained.

  12. Accuracy and reproducibility of tumor positioning during prolonged and multi-modality animal imaging studies

    International Nuclear Information System (INIS)

    Dedicated small-animal imaging devices, e.g. positron emission tomography (PET), computed tomography (CT) and magnetic resonance imaging (MRI) scanners, are being increasingly used for translational molecular imaging studies. The objective of this work was to determine the positional accuracy and precision with which tumors in situ can be reliably and reproducibly imaged on dedicated small-animal imaging equipment. We designed, fabricated and tested a custom rodent cradle with a stereotactic template to facilitate registration among image sets. To quantify tumor motion during our small-animal imaging protocols, 'gold standard' multi-modality point markers were inserted into tumor masses on the hind limbs of rats. Three types of imaging examination were then performed with the animals continuously anesthetized and immobilized: (i) consecutive microPET and MR images of tumor xenografts in which the animals remained in the same scanner for 2 h duration, (ii) multi-modality imaging studies in which the animals were transported between distant imaging devices and (iii) serial microPET scans in which the animals were repositioned in the same scanner for subsequent images. Our results showed that the animal tumor moved by less than 0.2-0.3 mm over a continuous 2 h microPET or MR imaging session. The process of transporting the animal between instruments introduced additional errors of ∼0.2 mm. In serial animal imaging studies, the positioning reproducibility within ∼0.8 mm could be obtained.

  13. Imaging corn plants with PhytoPET, a modular PET system for plant biology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.; Kross, B.; McKisson, J.; McKisson, J. E.; Weisenberger, A. G.; Xi, W.; Zorn, C.; Bonito, G.; Howell, C. R.; Reid, C. D.; Crowell, A.; Cumberbatch, L. C.; Topp, C.; Smith, M. F.

    2013-11-01

    PhytoPET is a modular positron emission tomography (PET) system designed specifically for plant imaging. The PhytoPET design allows flexible arrangements of PET detectors based on individual standalone detector modules built from single Hamamatsu H8500 position sensitive photomultiplier tubes and pixelated LYSO arrays. We have used the PhytoPET system to perform preliminary corn plant imaging studies at the Duke University Biology Department Phytotron. Initial evaluation of the PhytoPET system to image the biodistribution of the positron emitting tracer {sup 11}C in corn plants is presented. {sup 11}CO{sub 2} is loaded into corn seedlings by a leaf-labeling cuvette and translocation of {sup 11}C-sugars is imaged by a flexible arrangement of PhytoPET modules on each side. The PhytoPET system successfully images {sup 11}C within corn plants and allows for the dynamic measurement of {sup 11}C-sugar translocation from the leaf to the roots.

  14. PET/MR Imaging in Cancers of the Gastrointestinal Tract.

    Science.gov (United States)

    Paspulati, Raj Mohan; Gupta, Amit

    2016-10-01

    PET/computed tomography (PET/CT) is an established hybrid imaging technique for staging and follow-up of gastrointestinal (GI) tract malignancies, especially for colorectal carcinoma. Dedicated hybrid PET/MR imaging scanners are currently available for clinical use. Although they will not replace regular use of PET/CT, they may have utility in selected cases of GI tract malignancies. The superior soft tissue contrast resolution and depiction of anatomy and the functional information obtained from diffusion-weighted imaging (DWI) provided by MR imaging in PET/MR imaging are advantages over CT of PET/CT for T staging and follow-up of rectal carcinoma and for better characterization of liver lesions. Functional information from DWI and use of liver-specific MR imaging contrast agents are an added advantage in follow-up of liver metastases after systemic and locoregional treatment. New radiotracers will improve the utility of PET/MR imaging in staging and follow-up of tumors, which may not be [18F]-2-fluoro-2-deoxy-d-glucose avid, such as hepatocellular carcinoma and neuroendocrine tumors. PET/MR imaging also has application in selected cases of cholangiocarcinoma, gallbladder cancer, and pancreatic carcinoma for initial staging and follow-up assessment.

  15. PET/MR Imaging in Cancers of the Gastrointestinal Tract.

    Science.gov (United States)

    Paspulati, Raj Mohan; Gupta, Amit

    2016-10-01

    PET/computed tomography (PET/CT) is an established hybrid imaging technique for staging and follow-up of gastrointestinal (GI) tract malignancies, especially for colorectal carcinoma. Dedicated hybrid PET/MR imaging scanners are currently available for clinical use. Although they will not replace regular use of PET/CT, they may have utility in selected cases of GI tract malignancies. The superior soft tissue contrast resolution and depiction of anatomy and the functional information obtained from diffusion-weighted imaging (DWI) provided by MR imaging in PET/MR imaging are advantages over CT of PET/CT for T staging and follow-up of rectal carcinoma and for better characterization of liver lesions. Functional information from DWI and use of liver-specific MR imaging contrast agents are an added advantage in follow-up of liver metastases after systemic and locoregional treatment. New radiotracers will improve the utility of PET/MR imaging in staging and follow-up of tumors, which may not be [18F]-2-fluoro-2-deoxy-d-glucose avid, such as hepatocellular carcinoma and neuroendocrine tumors. PET/MR imaging also has application in selected cases of cholangiocarcinoma, gallbladder cancer, and pancreatic carcinoma for initial staging and follow-up assessment. PMID:27593246

  16. Correction of MRI-induced geometric distortions in whole-body small animal PET-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Frohwein, Lynn J., E-mail: frohwein@uni-muenster.de; Schäfers, Klaus P. [European Institute for Molecular Imaging, University of Münster, Münster 48149 (Germany); Hoerr, Verena; Faber, Cornelius [Department of Clinical Radiology, University Hospital of Münster, Münster 48149 (Germany)

    2015-07-15

    Purpose: The fusion of positron emission tomography (PET) and magnetic resonance imaging (MRI) data can be a challenging task in whole-body PET-MRI. The quality of the registration between these two modalities in large field-of-views (FOV) is often degraded by geometric distortions of the MRI data. The distortions at the edges of large FOVs mainly originate from MRI gradient nonlinearities. This work describes a method to measure and correct for these kind of geometric distortions in small animal MRI scanners to improve the registration accuracy of PET and MRI data. Methods: The authors have developed a geometric phantom which allows the measurement of geometric distortions in all spatial axes via control points. These control points are detected semiautomatically in both PET and MRI data with a subpixel accuracy. The spatial transformation between PET and MRI data is determined with these control points via 3D thin-plate splines (3D TPS). The transformation derived from the 3D TPS is finally applied to real MRI mouse data, which were acquired with the same scan parameters used in the phantom data acquisitions. Additionally, the influence of the phantom material on the homogeneity of the magnetic field is determined via field mapping. Results: The spatial shift according to the magnetic field homogeneity caused by the phantom material was determined to a mean of 0.1 mm. The results of the correction show that distortion with a maximum error of 4 mm could be reduced to less than 1 mm with the proposed correction method. Furthermore, the control point-based registration of PET and MRI data showed improved congruence after correction. Conclusions: The developed phantom has been shown to have no considerable negative effect on the homogeneity of the magnetic field. The proposed method yields an appropriate correction of the measured MRI distortion and is able to improve the PET and MRI registration. Furthermore, the method is applicable to whole-body small animal

  17. Non-FDG PET imaging of brain tumors

    Institute of Scientific and Technical Information of China (English)

    HUANG Zemin; GUAN Yihui; ZUO Chuantao; ZHANG Zhengwei; XUE Fangping; LIN Xiangtong

    2007-01-01

    Due to relatively high uptake of glucose in the brain cortex, the use of FDG PET imaging is greatly limited in brain tumor imaging, especially for low-grade gliomas and some metastatic tumours. More and more tracers with higher specificity were developed lately for brain tumor imaging. There are 3 main types of non-FDG PET tracers:amino acid tracers, choline tracers and nucleic acid tracers. These tracers are now widely applied in many aspects of brain tumor imaging. This article summarized the general use of non-FDG PET in different aspects of brain tumor imaging.

  18. 18F-fluoride PET imaging in a nude rat model of bone metastasis from breast cancer: Comparison with 18F-FDG and bioluminescence imaging

    International Nuclear Information System (INIS)

    Introduction: Clinically-relevant animal models and appropriate imaging diagnostic tools are essential to study cancer and develop novel therapeutics. We evaluated a model of bone metastasis in nude rats by micro-PET and bioluminescence imaging. Methods: A bone metastasis model was produced by intracardiac injection of osteotropic MDA-MB-231Bo-Luc human breast cancer cells into nude rats. Bioluminescence imaging and micro-PET scans using 18F-FDG and 18F-fluoride were acquired serially for 5 weeks. We correlated bioluminescence imaging, 18F-FDG and 18F-fluoride PET images, and histological slides. Results: Multiple bone metastases were successfully evaluated by bioluminescence imaging and 18F-FDG and 18F-fluoride PET scans. Bioluminescence photon flux increased exponentially on weekly follow-up. 18F-FDG PET revealed increased FDG uptake at the spine and bilaterally in the hind legs in week 2 images, and showed a progressive pattern up to 4 weeks that correlated with bioluminescence imaging. 18F-fluoride PET showed minimal abnormal findings in week 2 images, but it showed an irregular pattern at the spine from week 3 or 4 images. On quantitative analysis with standardized uptake values, a pattern of gradual increase was observed from week 2 to week 4 in both 18F-FDG PET and fluoride PET. Histopathological examination confirmed the formation of osteolytic metastasis and necrosis of the distal femur, which appeared as a photon defect on PET scans. Conclusion: Developing bone metastasis from breast cancer in a nude rat model was successfully evaluated with an animal PET imaging system and bioluminescence imaging. This nude rat model of bone metastasis, which can be evaluated by PET imaging, may be a valuable tool for evaluating early responses to novel therapeutics

  19. MR-based Motion Correction for PET Imaging

    OpenAIRE

    Ouyang, Jinsong; Li, Quanzheng; Fakhri, Georges El

    2013-01-01

    PET image quality is limited by patient motion. Emission data are blurred due to cardiac and/or respiratory motion. Although spatial resolution is 4 mm for standard clinical whole-body PET scanners, the effective resolution can be a low as 1 cm due to motion. Additionally, the deformation of attenuation medium causes image artifacts. Previously, gating is used to “freeze” the motion, but leads to significantly increased noise level. Simultaneous PET-MR modality offers a new way to perform PET...

  20. Accuracy and Radiation Dose of CT-Based Attenuation Correction for Small Animal PET: A Monte Carlo Simulation Study

    International Nuclear Information System (INIS)

    -Small animal PET allows qualitative assessment and quantitative measurement of biochemical processes in vivo, but the accuracy and reproducibility of imaging results can be affected by several parameters. The first aim of this study was to investigate the performance of different CT-based attenuation correction strategies and assess the resulting impact on PET images. The absorbed dose in different tissues caused by scanning procedures was also discussed to minimize biologic damage generated by radiation exposure due to PET/CT scanning. A small animal PET/CT system was modeled based on Monte Carlo simulation to generate imaging results and dose distribution. Three energy mapping methods, including the bilinear scaling method, the dual-energy method and the hybrid method which combines the kVp conversion and the dual-energy method, were investigated comparatively through assessing the accuracy of estimating linear attenuation coefficient at 511 keV and the bias introduced into PET quantification results due to CT-based attenuation correction. Our results showed that the hybrid method outperformed the bilinear scaling method, while the dual-energy method achieved the highest accuracy among the three energy mapping methods. Overall, the accuracy of PET quantification results have similar trend as that for the estimation of linear attenuation coefficients, whereas the differences between the three methods are more obvious in the estimation of linear attenuation coefficients than in the PET quantification results. With regards to radiation exposure from CT, the absorbed dose ranged between 7.29-45.58 mGy for 50-kVp scan and between 6.61-39.28 mGy for 80-kVp scan. For 18F radioactivity concentration of 1.86x105 Bq/ml, the PET absorbed dose was around 24 cGy for tumor with a target-to-background ratio of 8. The radiation levels for CT scans are not lethal to the animal, but concurrent use of PET in longitudinal study can increase the risk of biological effects. The

  1. Application of PET/SPECT imaging in vascular disease

    NARCIS (Netherlands)

    van der Vaart, M. G.; Meerwaidt, R.; Slart, R. H. J. A.; van Dam, G. M.; Tio, R. A.; Zeebregts, C. J.

    2008-01-01

    Background. Nuclear medicine imaging differs from other imaging modalities by showing physiological processes instead of anatomical details. Objective. To describe the current applications of positron emission tomography (PET) and single photon emission computed tomography (SPECT) as a diagnostic to

  2. PET FACE: MECHANISMS UNDERLYING HUMAN-ANIMAL RELATIONSHIPS

    Directory of Open Access Journals (Sweden)

    Marta eBorgi

    2016-03-01

    Full Text Available Accumulating behavioral and neurophysiological studies support the idea of infantile (cute faces as highly biologically relevant stimuli rapidly and unconsciously capturing attention and eliciting positive/affectionate behaviors, including willingness to care. It has been hypothesized that the presence of infantile physical and behavioral features in companion (or pet animals (i.e. dogs and cats might form the basis of our attraction to these species. Preliminary evidence has indeed shown that the human attentional bias toward the baby schema may extend to animal facial configurations. In this review, the role of facial cues, specifically of infantile traits and facial signals (i.e. eyes gaze as emotional and communicative signals is highlighted and discussed as regulating human-animal bond, similarly to what can be observed in the adult-infant interaction context. Particular emphasis is given to the neuroendocrine regulation of social bond between humans and animals through oxytocin secretion. Instead of considering companion animals as mere baby substitutes for their owners, in this review we highlight the central role of cats and dogs in human lives. Specifically, we consider the ability of companion animals to bond with humans as fulfilling the need for attention and emotional intimacy, thus serving similar psychological and adaptive functions as human-human friendships. In this context, facial cuteness is viewed not just as a releaser of care/parental behavior, but more in general as a trait motivating social engagement. To conclude, the impact of this information for applied disciplines is briefly described, particularly in consideration of the increasing evidence of the beneficial effects of contacts with animals for human health and wellbeing.

  3. Pet Face: Mechanisms Underlying Human-Animal Relationships

    Science.gov (United States)

    Borgi, Marta; Cirulli, Francesca

    2016-01-01

    Accumulating behavioral and neurophysiological studies support the idea of infantile (cute) faces as highly biologically relevant stimuli rapidly and unconsciously capturing attention and eliciting positive/affectionate behaviors, including willingness to care. It has been hypothesized that the presence of infantile physical and behavioral features in companion (or pet) animals (i.e., dogs and cats) might form the basis of our attraction to these species. Preliminary evidence has indeed shown that the human attentional bias toward the baby schema may extend to animal facial configurations. In this review, the role of facial cues, specifically of infantile traits and facial signals (i.e., eyes gaze) as emotional and communicative signals is highlighted and discussed as regulating the human-animal bond, similarly to what can be observed in the adult-infant interaction context. Particular emphasis is given to the neuroendocrine regulation of the social bond between humans and animals through oxytocin secretion. Instead of considering companion animals as mere baby substitutes for their owners, in this review we highlight the central role of cats and dogs in human lives. Specifically, we consider the ability of companion animals to bond with humans as fulfilling the need for attention and emotional intimacy, thus serving similar psychological and adaptive functions as human-human friendships. In this context, facial cuteness is viewed not just as a releaser of care/parental behavior, but, more in general, as a trait motivating social engagement. To conclude, the impact of this information for applied disciplines is briefly described, particularly in consideration of the increasing evidence of the beneficial effects of contacts with animals for human health and wellbeing. PMID:27014120

  4. Pet Face: Mechanisms Underlying Human-Animal Relationships.

    Science.gov (United States)

    Borgi, Marta; Cirulli, Francesca

    2016-01-01

    Accumulating behavioral and neurophysiological studies support the idea of infantile (cute) faces as highly biologically relevant stimuli rapidly and unconsciously capturing attention and eliciting positive/affectionate behaviors, including willingness to care. It has been hypothesized that the presence of infantile physical and behavioral features in companion (or pet) animals (i.e., dogs and cats) might form the basis of our attraction to these species. Preliminary evidence has indeed shown that the human attentional bias toward the baby schema may extend to animal facial configurations. In this review, the role of facial cues, specifically of infantile traits and facial signals (i.e., eyes gaze) as emotional and communicative signals is highlighted and discussed as regulating the human-animal bond, similarly to what can be observed in the adult-infant interaction context. Particular emphasis is given to the neuroendocrine regulation of the social bond between humans and animals through oxytocin secretion. Instead of considering companion animals as mere baby substitutes for their owners, in this review we highlight the central role of cats and dogs in human lives. Specifically, we consider the ability of companion animals to bond with humans as fulfilling the need for attention and emotional intimacy, thus serving similar psychological and adaptive functions as human-human friendships. In this context, facial cuteness is viewed not just as a releaser of care/parental behavior, but, more in general, as a trait motivating social engagement. To conclude, the impact of this information for applied disciplines is briefly described, particularly in consideration of the increasing evidence of the beneficial effects of contacts with animals for human health and wellbeing. PMID:27014120

  5. 77 FR 41716 - Animal Welfare; Retail Pet Stores and Licensing Exemptions

    Science.gov (United States)

    2012-07-16

    ... animals sold at retail under the protection of the Animal Welfare Act (AWA). We are also announcing the... regulations to bring more pet animals sold at retail under the protection of the Animal Welfare Act (AWA... Animal and Plant Health Inspection Service 9 CFR Parts 1 and 2 RIN 0579-AC36 Animal Welfare; Retail......

  6. Kinetic modeling in PET imaging of hypoxia

    DEFF Research Database (Denmark)

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

    2014-01-01

    be used for non-invasive mapping of tissue oxygenation in vivo and several hypoxia specific PET tracers have been developed. Evaluation of PET data in the clinic is commonly based on visual assessment together with semiquantitative measurements e.g. standard uptake value (SUV). However, dynamic PET...

  7. Automated movement correction for dynamic PET/CT images: Evaluation with phantom and patient data

    OpenAIRE

    Ye, H.; Wong, KP; Wardak, M; Dahlbom, M.; Kepe, V; Barrio, JR; Nelson, LD; Small, GW; Huang, SC

    2014-01-01

    Head movement during a dynamic brain PET/CT imaging results in mismatch between CT and dynamic PET images. It can cause artifacts in CT-based attenuation corrected PET images, thus affecting both the qualitative and quantitative aspects of the dynamic PET images and the derived parametric images. In this study, we developed an automated retrospective image-based movement correction (MC) procedure. The MC method first registered the CT image to each dynamic PET frames, then re-reconstructed th...

  8. Twelve automated thresholding methods for segmentation of PET images: a phantom study

    Science.gov (United States)

    Prieto, Elena; Lecumberri, Pablo; Pagola, Miguel; Gómez, Marisol; Bilbao, Izaskun; Ecay, Margarita; Peñuelas, Iván; Martí-Climent, Josep M.

    2012-06-01

    Tumor volume delineation over positron emission tomography (PET) images is of great interest for proper diagnosis and therapy planning. However, standard segmentation techniques (manual or semi-automated) are operator dependent and time consuming while fully automated procedures are cumbersome or require complex mathematical development. The aim of this study was to segment PET images in a fully automated way by implementing a set of 12 automated thresholding algorithms, classical in the fields of optical character recognition, tissue engineering or non-destructive testing images in high-tech structures. Automated thresholding algorithms select a specific threshold for each image without any a priori spatial information of the segmented object or any special calibration of the tomograph, as opposed to usual thresholding methods for PET. Spherical 18F-filled objects of different volumes were acquired on clinical PET/CT and on a small animal PET scanner, with three different signal-to-background ratios. Images were segmented with 12 automatic thresholding algorithms and results were compared with the standard segmentation reference, a threshold at 42% of the maximum uptake. Ridler and Ramesh thresholding algorithms based on clustering and histogram-shape information, respectively, provided better results that the classical 42%-based threshold (p < 0.05). We have herein demonstrated that fully automated thresholding algorithms can provide better results than classical PET segmentation tools.

  9. Twelve automated thresholding methods for segmentation of PET images: a phantom study

    International Nuclear Information System (INIS)

    Tumor volume delineation over positron emission tomography (PET) images is of great interest for proper diagnosis and therapy planning. However, standard segmentation techniques (manual or semi-automated) are operator dependent and time consuming while fully automated procedures are cumbersome or require complex mathematical development. The aim of this study was to segment PET images in a fully automated way by implementing a set of 12 automated thresholding algorithms, classical in the fields of optical character recognition, tissue engineering or non-destructive testing images in high-tech structures. Automated thresholding algorithms select a specific threshold for each image without any a priori spatial information of the segmented object or any special calibration of the tomograph, as opposed to usual thresholding methods for PET. Spherical 18F-filled objects of different volumes were acquired on clinical PET/CT and on a small animal PET scanner, with three different signal-to-background ratios. Images were segmented with 12 automatic thresholding algorithms and results were compared with the standard segmentation reference, a threshold at 42% of the maximum uptake. Ridler and Ramesh thresholding algorithms based on clustering and histogram-shape information, respectively, provided better results that the classical 42%-based threshold (p < 0.05). We have herein demonstrated that fully automated thresholding algorithms can provide better results than classical PET segmentation tools. (paper)

  10. Non-Invasive in vivo Imaging in Small Animal Research

    Directory of Open Access Journals (Sweden)

    V. Koo

    2006-01-01

    Full Text Available Non-invasive real time in vivo molecular imaging in small animal models has become the essential bridge between in vitro data and their translation into clinical applications. The tremendous development and technological progress, such as tumour modelling, monitoring of tumour growth and detection of metastasis, has facilitated translational drug development. This has added to our knowledge on carcinogenesis. The modalities that are commonly used include Magnetic Resonance Imaging (MRI, Computed Tomography (CT, Positron Emission Tomography (PET, bioluminescence imaging, fluorescence imaging and multi-modality imaging systems. The ability to obtain multiple images longitudinally provides reliable information whilst reducing animal numbers. As yet there is no one modality that is ideal for all experimental studies. This review outlines the instrumentation available together with corresponding applications reported in the literature with particular emphasis on cancer research. Advantages and limitations to current imaging technology are discussed and the issues concerning small animal care during imaging are highlighted.

  11. Sparsity-constrained PET image reconstruction with learned dictionaries

    Science.gov (United States)

    Tang, Jing; Yang, Bao; Wang, Yanhua; Ying, Leslie

    2016-09-01

    PET imaging plays an important role in scientific and clinical measurement of biochemical and physiological processes. Model-based PET image reconstruction such as the iterative expectation maximization algorithm seeking the maximum likelihood solution leads to increased noise. The maximum a posteriori (MAP) estimate removes divergence at higher iterations. However, a conventional smoothing prior or a total-variation (TV) prior in a MAP reconstruction algorithm causes over smoothing or blocky artifacts in the reconstructed images. We propose to use dictionary learning (DL) based sparse signal representation in the formation of the prior for MAP PET image reconstruction. The dictionary to sparsify the PET images in the reconstruction process is learned from various training images including the corresponding MR structural image and a self-created hollow sphere. Using simulated and patient brain PET data with corresponding MR images, we study the performance of the DL-MAP algorithm and compare it quantitatively with a conventional MAP algorithm, a TV-MAP algorithm, and a patch-based algorithm. The DL-MAP algorithm achieves improved bias and contrast (or regional mean values) at comparable noise to what the other MAP algorithms acquire. The dictionary learned from the hollow sphere leads to similar results as the dictionary learned from the corresponding MR image. Achieving robust performance in various noise-level simulation and patient studies, the DL-MAP algorithm with a general dictionary demonstrates its potential in quantitative PET imaging.

  12. Companion animal welfare and possible implications on the human-pet relationship

    Directory of Open Access Journals (Sweden)

    Marina Verga

    2010-01-01

    Full Text Available The role of pets (dogs and cats in particular in human society has changed in recent years. Nowadays pets are an integral part of the human family and this aspect has many social and emotional implications. For their positive effects on human health, pets are also employed in some special and therapeutic activities known by the generic term of “Pet Therapy”. In these programmes the animal becomes an integral part of the therapeutic plan in order to induce some physical, social, emotional, and cognitive improvements in human patients. However, the close bond between companion animals and man is not always the herald of beneficial effects. Sometimes the welfare of pets may be compromised by distress due to many factors, mostly related to the environment and to management by humans. Both behavioural and physiological variables may be analysed in order to evaluate welfare level in pets. Reduced welfare may be indicated by the onset of some behavioural problems, which have usually a multifactorial aetiology, related both to the genetic individual basis and environmental factors. Physiological variables which may be analysed in order to evaluate pet welfare include hormone levels, mainly related to the HPA (hypothalamus-pituitary-adrenal- axis and to the immune systems activations. Behavioural problems may also lead to the relinquishment of pets to shelters. Animals housed in rescue shelters cannot display their ethogram and show behavioural and physiological signs of distress. Thus it is very important to improve the human-pet relationship both by educating owners and reducing the number of stray animals, in accordance with the indications of the European Convention for the Protection of Pet Animals stated at Strasbourg in 1987, mainly as regards pet breeding and welfare. Humans have to realise that adopting pets implies the responsibility to care for their health and welfare, avoiding undue stress in the living environment and improving the

  13. PET/MRI in Oncological Imaging: State of the Art.

    Science.gov (United States)

    Bashir, Usman; Mallia, Andrew; Stirling, James; Joemon, John; MacKewn, Jane; Charles-Edwards, Geoff; Goh, Vicky; Cook, Gary J

    2015-01-01

    Positron emission tomography (PET) combined with magnetic resonance imaging (MRI) is a hybrid technology which has recently gained interest as a potential cancer imaging tool. Compared with CT, MRI is advantageous due to its lack of ionizing radiation, superior soft-tissue contrast resolution, and wider range of acquisition sequences. Several studies have shown PET/MRI to be equivalent to PET/CT in most oncological applications, possibly superior in certain body parts, e.g., head and neck, pelvis, and in certain situations, e.g., cancer recurrence. This review will update the readers on recent advances in PET/MRI technology and review key literature, while highlighting the strengths and weaknesses of PET/MRI in cancer imaging. PMID:26854157

  14. PET/MRI in Oncological Imaging: State of the Art

    Directory of Open Access Journals (Sweden)

    Usman Bashir

    2015-07-01

    Full Text Available Positron emission tomography (PET combined with magnetic resonance imaging (MRI is a hybrid technology which has recently gained interest as a potential cancer imaging tool. Compared with CT, MRI is advantageous due to its lack of ionizing radiation, superior soft-tissue contrast resolution, and wider range of acquisition sequences. Several studies have shown PET/MRI to be equivalent to PET/CT in most oncological applications, possibly superior in certain body parts, e.g., head and neck, pelvis, and in certain situations, e.g., cancer recurrence. This review will update the readers on recent advances in PET/MRI technology and review key literature, while highlighting the strengths and weaknesses of PET/MRI in cancer imaging.

  15. MR-Based Cardiac and Respiratory Motion-Compensation Techniques for PET-MR Imaging.

    Science.gov (United States)

    Munoz, Camila; Kolbitsch, Christoph; Reader, Andrew J; Marsden, Paul; Schaeffter, Tobias; Prieto, Claudia

    2016-04-01

    Cardiac and respiratory motion cause image quality degradation in PET imaging, affecting diagnostic accuracy of the images. Whole-body simultaneous PET-MR scanners allow for using motion information estimated from MR images to correct PET data and produce motion-compensated PET images. This article reviews methods that have been proposed to estimate motion from MR images and different techniques to include this information in PET reconstruction, in order to overcome the problem of cardiac and respiratory motion in PET-MR imaging. MR-based motion correction techniques significantly increase lesion detectability and contrast, and also improve accuracy of uptake values in PET images.

  16. Contourlet-based active contour model for PET image segmentation

    NARCIS (Netherlands)

    Abdoli, M.; Dierckx, R. A. J. O.; Zaidi, H.

    2013-01-01

    Purpose: PET-guided radiation therapy treatment planning, clinical diagnosis, assessment of tumor growth, and therapy response rely on the accurate delineation of the tumor volume and quantification of tracer uptake. Most PET image segmentation techniques proposed thus far are suboptimal in the pres

  17. Non-oncological positron emission tomography (PET): brain imaging

    International Nuclear Information System (INIS)

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

  18. PET IMAGING STUDIES IN DRUG ABUSE RESEARCH.

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Volkow, N.D.; Ding, Y.S.; Logan, J.; Wang, G.J.

    2001-01-29

    There is overwhelming evidence that addiction is a disease of the brain (Leshner, 1997). Yet public perception that addiction is a reflection of moral weakness or a lack of willpower persists. The insidious consequence of this perception is that we lose sight of the fact that there are enormous medical consequences of addiction including the fact that a large fraction of the total deaths from cancer and heart disease are caused by smoking addiction. Ironically the medical school that educates physicians in addiction medicine and the cancer hospital that has a smoking cessation clinic are vanishingly rare and efforts at harm reduction are frequently met with a public indignation. Meanwhile the number of people addicted to substances is enormous and increasing particularly the addictions to cigarettes and alcohol. It is particularly tragic that addiction usually begins in adolescence and becomes a chronic relapsing problem and there are basically no completely effective treatments. Clearly we need to understand how drugs of abuse affect the brain and we need to be creative in using this information to develop effective treatments. Imaging technologies have played a major role in the conceptualization of addiction as a disease of the brain (Fowler et al., 1998a; Fowler et al., 1999a). New knowledge has been driven by advances in radiotracer design and chemistry and positron emission tomography (PET) instrumentation and the integration of these scientific tools with the tools of biochemistry, pharmacology and medicine. This topic cuts across the medical specialties of neurology, psychiatry, cancer and heart disease because of the high medical, social and economic toll that drugs of abuse, including and especially the legal drugs, cigarettes and alcohol, take on society. In this chapter we will begin by highlighting the important role that chemistry has played in making it possible to quantitatively image the movement of drugs as well as their effects on the human brain

  19. Development of a PET/Cerenkov-light hybrid imaging system

    International Nuclear Information System (INIS)

    Purpose: Cerenkov-light imaging is a new molecular imaging technology that detects visible photons from high-speed electrons using a high sensitivity optical camera. However, the merit of Cerenkov-light imaging remains unclear. If a PET/Cerenkov-light hybrid imaging system were developed, the merit of Cerenkov-light imaging would be clarified by directly comparing these two imaging modalities. Methods: The authors developed and tested a PET/Cerenkov-light hybrid imaging system that consists of a dual-head PET system, a reflection mirror located above the subject, and a high sensitivity charge coupled device (CCD) camera. The authors installed these systems inside a black box for imaging the Cerenkov-light. The dual-head PET system employed a 1.2 × 1.2 × 10 mm3 GSO arranged in a 33 × 33 matrix that was optically coupled to a position sensitive photomultiplier tube to form a GSO block detector. The authors arranged two GSO block detectors 10 cm apart and positioned the subject between them. The Cerenkov-light above the subject is reflected by the mirror and changes its direction to the side of the PET system and is imaged by the high sensitivity CCD camera. Results: The dual-head PET system had a spatial resolution of ∼1.2 mm FWHM and sensitivity of ∼0.31% at the center of the FOV. The Cerenkov-light imaging system's spatial resolution was ∼275μm for a 22Na point source. Using the combined PET/Cerenkov-light hybrid imaging system, the authors successfully obtained fused images from simultaneously acquired images. The image distributions are sometimes different due to the light transmission and absorption in the body of the subject in the Cerenkov-light images. In simultaneous imaging of rat, the authors found that 18F-FDG accumulation was observed mainly in the Harderian gland on the PET image, while the distribution of Cerenkov-light was observed in the eyes. Conclusions: The authors conclude that their developed PET/Cerenkov-light hybrid imaging

  20. Development of a PET/Cerenkov-light hybrid imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Hamamura, Fuka; Kato, Katsuhiko; Ogata, Yoshimune [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Aichi 461-8673 (Japan); Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Hatazawa, Jun [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan); Watabe, Hiroshi [CYRIC, Tohoku University, Miyagi 980-8578 (Japan)

    2014-09-15

    Purpose: Cerenkov-light imaging is a new molecular imaging technology that detects visible photons from high-speed electrons using a high sensitivity optical camera. However, the merit of Cerenkov-light imaging remains unclear. If a PET/Cerenkov-light hybrid imaging system were developed, the merit of Cerenkov-light imaging would be clarified by directly comparing these two imaging modalities. Methods: The authors developed and tested a PET/Cerenkov-light hybrid imaging system that consists of a dual-head PET system, a reflection mirror located above the subject, and a high sensitivity charge coupled device (CCD) camera. The authors installed these systems inside a black box for imaging the Cerenkov-light. The dual-head PET system employed a 1.2 × 1.2 × 10 mm{sup 3} GSO arranged in a 33 × 33 matrix that was optically coupled to a position sensitive photomultiplier tube to form a GSO block detector. The authors arranged two GSO block detectors 10 cm apart and positioned the subject between them. The Cerenkov-light above the subject is reflected by the mirror and changes its direction to the side of the PET system and is imaged by the high sensitivity CCD camera. Results: The dual-head PET system had a spatial resolution of ∼1.2 mm FWHM and sensitivity of ∼0.31% at the center of the FOV. The Cerenkov-light imaging system's spatial resolution was ∼275μm for a {sup 22}Na point source. Using the combined PET/Cerenkov-light hybrid imaging system, the authors successfully obtained fused images from simultaneously acquired images. The image distributions are sometimes different due to the light transmission and absorption in the body of the subject in the Cerenkov-light images. In simultaneous imaging of rat, the authors found that {sup 18}F-FDG accumulation was observed mainly in the Harderian gland on the PET image, while the distribution of Cerenkov-light was observed in the eyes. Conclusions: The authors conclude that their developed PET

  1. Ultrasonography Fused with PET-CT Hybrid Imaging

    DEFF Research Database (Denmark)

    Udesen, Jesper; Ewertsen, Caroline; Gran, Fredrik;

    2011-01-01

    We present a method with fusion of images of three modalities 18F-FDG PET, CT, and 3-D ultrasound (US) applied to imaging of the anal canal and the rectum. To obtain comparable geometries in the three imaging modalities, a plexiglas rod, with the same dimensions as the US transducer, is placed...... in the anal canal prior to the PET-CT examination. The method is based on manual co-registration of PET-CT images and 3-D US images. The three-modality imaging of the rectum-anal canal may become useful as a supplement to conventional imaging in the external radiation therapy in the treatment of anal cancer......-modality imaging may also be used in certain other diagnostic or therapeutic fields....

  2. Cardiovascular hybrid imaging using PET/MRI; Kardiovaskulaere Hybridbildgebung mit PET/MRT

    Energy Technology Data Exchange (ETDEWEB)

    Nensa, Felix; Schlosser, Thomas [Universitaetsklinikum Essen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie

    2014-12-15

    The following overview provides a summary of the state of the art and research as well as potential clinical applications of cardiovascular PET/MR imaging. PET/MRI systems have been clinically available for a few years, and their use in cardiac imaging has been successfully demonstrated. At this period in time, some of the technical difficulties that arose at the beginning have been solved; in particular with respect to MRI-based attenuation correction, caution should be exercised with PET quantification. In addition, many promising technical options are still in the developmental stage, such as MRI-based motion correction of PET data resulting from simultaneous MR acquisition, and are not yet available for cardiovascular imaging. On the other hand, PET/MRI has been used to demonstrate significant pathologies such as acute and chronic myocardial infarction, myocarditis or cardiac sarcoidosis; future applications in clinical routine or within studies appear to be possible. In coming years additional studies will have to be performed to prove diagnostic gain at a reasonable cost-benefit ratio before valid conclusions are possible regarding the clinical utility and future of cardiovascular PET/MR imaging.

  3. Molecular imaging of cancer using PET and SPECT

    DEFF Research Database (Denmark)

    Kjaer, Andreas

    2006-01-01

    Molecular imaging allows for the study of molecular and cellular events in the living intact organism. The nuclear medicine methodologies of positron emission tomography (PET) and single photon emission computer tomography (SPECT) posses several advantages, which make them particularly suited...

  4. PET Imaging and biodistribution of chemically modified bacteriophage MS2.

    Science.gov (United States)

    Farkas, Michelle E; Aanei, Ioana L; Behrens, Christopher R; Tong, Gary J; Murphy, Stephanie T; O'Neil, James P; Francis, Matthew B

    2013-01-01

    The fields of nanotechnology and medicine have merged in the development of new imaging and drug delivery agents based on nanoparticle platforms. As one example, a mutant of bacteriophage MS2 can be differentially modified on the exterior and interior surfaces for the concurrent display of targeting functionalities and payloads, respectively. In order to realize their potential for use in in vivo applications, the biodistribution and circulation properties of this class of agents must first be investigated. A means of modulating and potentially improving the characteristics of nanoparticle agents is the appendage of PEG chains. Both MS2 and MS2-PEG capsids possessing interior DOTA chelators were labeled with (64)Cu and injected intravenously into mice possessing tumor xenografts. Dynamic imaging of the agents was performed using PET-CT on a single animal per sample, and the biodistribution at the terminal time point (24 h) was assessed by gamma counting of the organs ex vivo for 3 animals per agent. Compared to other viral capsids of similar size, the MS2 agents showed longer circulation times. Both MS2 and MS2-PEG bacteriophage behaved similarly, although the latter agent showed significantly less uptake in the spleen. This effect may be attributed to the ability of the PEG chains to mask the capsid charge. Although the tumor uptake of the agents may result from the enhanced permeation and retention (EPR) effect, selective tumor imaging may be achieved in the future by using exterior targeting groups. PMID:23214968

  5. Assessment of oxidative metabolism in Brown Fat using PET imaging

    OpenAIRE

    Otto eMuzik; Mangner, Thomas J.; Granneman, James G.

    2012-01-01

    Objective: Although it has been believed that brown adipose tissue (BAT) depots disappear shortly after the perinatal period in humans, PET imaging using the glucose analog FDG has shown unequivocally the existence of functional BAT in humans. The objective of this study was to determine, using dynamic oxygen-15 (15O) PET imaging, to what extent BAT thermogenesis is activated in adults during cold stress and to establish the relationship between BAT oxidative metabolism and FDG tracer uptake....

  6. Assessment of Oxidative Metabolism in Brown Fat Using PET Imaging

    OpenAIRE

    Muzik, Otto; Mangner, Thomas J.; Granneman, James G.

    2012-01-01

    Objective: Although it has been believed that brown adipose tissue (BAT) depots disappear shortly after the perinatal period in humans, positron emission tomography (PET) imaging using the glucose analog 18F-deoxy-d-glucose (FDG) has shown unequivocally the existence of functional BAT in humans, suggesting that most humans have some functional BAT. The objective of this study was to determine, using dynamic oxygen-15 (15O) PET imaging, to what extent BAT thermogenesis is activated in adults d...

  7. PET/CT scanners: a hardware approach to image fusion.

    Science.gov (United States)

    Townsend, David W; Beyer, Thomas; Blodgett, Todd M

    2003-07-01

    New technology that combines positron tomography with x-ray computed tomography (PET/CT) is available from all major vendors of PET imaging equipment: CTI, Siemens, GE, Philips. Although not all vendors have made the same design choices as those described in this review all have in common that their high performance design places a commercial CT scanner in tandem with a commercial PET scanner. The level of physical integration is actually less than that of the original prototype design where the CT and PET components were mounted on the same rotating support. There will undoubtedly be a demand for PET/CT technology with a greater level of integration, and at a reduced cost. This may be achieved through the design of a scanner specifically for combined anatomical and functional imaging, rather than a design combining separate CT and PET scanners, as in the current approaches. By avoiding the duplication of data acquisition and image reconstruction functions, for example, a more integrated design should also allow cost savings over current commercial PET/CT scanners. The goal is then to design and build a device specifically for imaging the function and anatomy of cancer in the most optimal and effective way, without conceptualizing it as combined PET and CT. The development of devices specifically for imaging a particular disease (eg, cancer) differs from the conventional approach of, for example, an all-purpose anatomical imaging device such as a CT scanner. This new concept targets more of a disease management approach rather than the usual division into the medical specialties of radiology (anatomical imaging) and nuclear medicine (functional imaging). PMID:12931321

  8. Spatial resolution evaluation with a pair of two four-layer DOI detectors for small animal PET scanner: jPET-RD

    Energy Technology Data Exchange (ETDEWEB)

    Nishikido, Fumihiko [National Institute of Radiological Sciences, Anagawa 4-9-1 Inage-ku, Chiba-shi, Chiba 263-8555 (Japan)], E-mail: funis@nirs.go.jp; Tsuda, Tomoaki [Shimadzu Corporation, Nishinokyo Kuwabaracho 1 Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Yoshida, Eiji; Inadama, Naoko; Shibuya, Kengo; Yamaya, Taiga [National Institute of Radiological Sciences, Anagawa 4-9-1 Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Kitamura, Keishi [Shimadzu Corporation, Nishinokyo Kuwabaracho 1 Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Takahashi, Kei [National Institute of Radiological Sciences, Anagawa 4-9-1 Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Graduate School of Science and Technology, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba-shi, Chiba 263-8522 (Japan); Ohmura, Atsushi [National Institute of Radiological Sciences, Anagawa 4-9-1 Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Graduate School of Advanced Science and Engineering, Waseda University, Okubo 3-4-1, Shinjuku-ku, Tokyo 169-8555 (Japan); Murayama, Hideo [National Institute of Radiological Sciences, Anagawa 4-9-1 Inage-ku, Chiba-shi, Chiba 263-8555 (Japan)

    2008-01-01

    We are developing a small animal PET scanner, 'jPET-RD' to achieve high sensitivity as well as high spatial resolution by using four-layer depth-of-interaction (DOI) detectors. The jPET-RD is designed with two detector rings. Each detector ring is composed of six DOI detectors arranged hexagonally. The diameter of the field-of-view (FOV) is 8.8 cm, which is smaller than typical small animal PET scanners on the market now. Each detector module consists of a crystal block and a 256-channel flat panel position-sensitive photomultiplier tube. The crystal block, consisting of 32x32x4 crystal (4096 crystals, each 1.46 mmx1.46 mmx4.5 mm) and a reflector, is mounted on the 256ch FP-PMT. In this study, we evaluated the spatial resolution of reconstructed images with the evaluation system of two four-layer DOI detectors which consist of 32x32x4 LYSO (Lu: 98%, Y: 2%) crystals coupled on the 256ch FP-PMT by using RTV rubber. The spatial resolution of 1.5 mm was obtained at the center of the FOV by the filtered back projection. The spatial resolution, better than 2 mm in the whole FOV, was also achieved with DOI while the spatial resolution without DOI was degraded to 3.3 mm.

  9. Fluorine-18 NaF PET imaging of child abuse

    International Nuclear Information System (INIS)

    We describe the use of 18F-NaF positron emission tomography (PET) whole-body imaging for the evaluation of skeletal trauma in a case of suspected child abuse. To our knowledge, 18F NaF PET has not been used in the past for the evaluation of child abuse. In our patient, this technique detected all sites of trauma shown by initial and follow-up skeletal surveys, including bilateral metaphyseal fractures of the proximal humeri. Fluorine-18 NaF PET has potential advantage over Tc-99m-labeled methylene diphosphonate (MDP) based upon superior image contrast and spatial resolution. (orig.)

  10. Fluorine-18 NaF PET imaging of child abuse

    Energy Technology Data Exchange (ETDEWEB)

    Drubach, Laura A. [Children' s Hospital Boston and Harvard Medical School, Department of Radiology, Division of Nuclear Medicine/PET, Boston, MA (United States); Sapp, Mark.V. [School of Osteopathic Medicine, Child Abuse Research Education and Services (CARES) Institute University of Medicine and Dentistry of New Jersey, New Jersey (United States); Laffin, Stephen [Children' s Hospital Boston, Department of Radiology, Division of Nuclear Medicine/PET, Boston, MA (United States); Kleinman, Paul K. [Children' s Hospital Boston and Harvard Medical School, Department of Radiology, Division of Musculoskeletal Imaging, Boston, MA (United States)

    2008-07-15

    We describe the use of {sup 18}F-NaF positron emission tomography (PET) whole-body imaging for the evaluation of skeletal trauma in a case of suspected child abuse. To our knowledge, 18F NaF PET has not been used in the past for the evaluation of child abuse. In our patient, this technique detected all sites of trauma shown by initial and follow-up skeletal surveys, including bilateral metaphyseal fractures of the proximal humeri. Fluorine-18 NaF PET has potential advantage over Tc-99m-labeled methylene diphosphonate (MDP) based upon superior image contrast and spatial resolution. (orig.)

  11. Evaluation of New Inorganic Scintillators for Application in a Prototype Small Animal PET Scanner

    CERN Document Server

    Kuntner, C

    2003-01-01

    In the study of new pharmaceuticals as well as brain and genetic research, Positron Emission Tomography (PET) is a useful method. It has also recently entered the clinical domain in cardiology and particularly in oncology. Small animals such as mice, are often used to validate sophisticated models of human disease. High spatial resolution PET instrumentation is therefore necessary due to the reduced dimensions of the organs. Inorganic scintillators are employed in most of the diagnostic imaging devices. The ultimate performance of the PET scanner is tightly bound to the scintillation properties of the crystals. In the last years there has been an effort to develop new scintillating materials characterized by high light output, high detection efficiency and fast decay time. The most studied systems are mainly Ce3+-doped crystals such as LSO:Ce, YAP:Ce, LuAP:Ce, and recently also mixed Lux(RE3+)1-xAlO3:Ce crystals. These crystals are very attractive for medical application because of their high density (with th...

  12. The benefit of pets and animal-assisted therapy to the health of older individuals.

    Science.gov (United States)

    Cherniack, E Paul; Cherniack, Ariella R

    2014-01-01

    Many studies utilizing dogs, cats, birds, fish, and robotic simulations of animals have tried to ascertain the health benefits of pet ownership or animal-assisted therapy in the elderly. Several small unblinded investigations outlined improvements in behavior in demented persons given treatment in the presence of animals. Studies piloting the use of animals in the treatment of depression and schizophrenia have yielded mixed results. Animals may provide intangible benefits to the mental health of older persons, such as relief social isolation and boredom, but these have not been formally studied. Several investigations of the effect of pets on physical health suggest animals can lower blood pressure, and dog walkers partake in more physical activity. Dog walking, in epidemiological studies and few preliminary trials, is associated with lower complication risk among patients with cardiovascular disease. Pets may also have harms: they may be expensive to care for, and their owners are more likely to fall. Theoretically, zoonotic infections and bites can occur, but how often this occurs in the context of pet ownership or animal-assisted therapy is unknown. Despite the poor methodological quality of pet research after decades of study, pet ownership and animal-assisted therapy are likely to continue due to positive subjective feelings many people have toward animals. PMID:25477957

  13. The Benefit of Pets and Animal-Assisted Therapy to the Health of Older Individuals

    Directory of Open Access Journals (Sweden)

    E. Paul Cherniack

    2014-01-01

    Full Text Available Many studies utilizing dogs, cats, birds, fish, and robotic simulations of animals have tried to ascertain the health benefits of pet ownership or animal-assisted therapy in the elderly. Several small unblinded investigations outlined improvements in behavior in demented persons given treatment in the presence of animals. Studies piloting the use of animals in the treatment of depression and schizophrenia have yielded mixed results. Animals may provide intangible benefits to the mental health of older persons, such as relief social isolation and boredom, but these have not been formally studied. Several investigations of the effect of pets on physical health suggest animals can lower blood pressure, and dog walkers partake in more physical activity. Dog walking, in epidemiological studies and few preliminary trials, is associated with lower complication risk among patients with cardiovascular disease. Pets may also have harms: they may be expensive to care for, and their owners are more likely to fall. Theoretically, zoonotic infections and bites can occur, but how often this occurs in the context of pet ownership or animal-assisted therapy is unknown. Despite the poor methodological quality of pet research after decades of study, pet ownership and animal-assisted therapy are likely to continue due to positive subjective feelings many people have toward animals.

  14. Human-animal bonds II: the role of pets in family systems and family therapy.

    Science.gov (United States)

    Walsh, Froma

    2009-12-01

    The vast majority of pet owners regard their companion animals as family members, yet the role of pets in family systems and family therapy has received little attention in research, training, and practice. This article first notes the benefits of family pets and their importance for resilience. It then examines their role in couple and family processes and their involvement in relational dynamics and tensions. Next, it addresses bereavement in the loss of a cherished pet, influences complicating grief, and facilitation of mourning and adaptation. Finally, it explores the ways that clients' pets and the use of therapists' companion animals in animal-assisted therapy can inform and enrich couple and family therapy as valuable resources in healing. PMID:19930434

  15. Use of animal waste for the production of pet food for dogs

    OpenAIRE

    Kubáčková, Anna

    2013-01-01

    The reason why I have chosen the topic named “Use of animal waste for the production of pet food for dogs“ was mainly the fact that I am interested in pet food for dogs its composition and use of animal waste for its prepare. Literature research is focused on the use of animal waste, such as slaughter waste, uneaten leftovers from the store, etc., to the production of feed dogs as pets. It can be industry food, which has three sections dry food, semi-dry food and canned or homemade BARF di...

  16. Dynamic {sup 11}C-methionine PET analysis has an additional value for differentiating malignant tumors from granulomas: an experimental study using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Songji; Zhao, Yan [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Kuge, Yuji; Hatano, Toshiyuki [Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan); Yi, Min; Kohanawa, Masashi [Hokkaido University, Department of Advanced Medicine, Graduate School of Medicine, Sapporo (Japan); Magota, Keiichi; Tamaki, Nagara [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Nishijima, Ken-ichi [Hokkaido University, Department of Molecular Imaging, Graduate School of Medicine, Sapporo (Japan)

    2011-10-15

    We evaluated whether the dynamic profile of L-{sup 11}C-methionine ({sup 11}C-MET) may have an additional value in differentiating malignant tumors from granulomas in experimental rat models by small animal positron emission tomography (PET). Rhodococcus aurantiacus and allogenic rat C6 glioma cells were inoculated, respectively, into the right and left calf muscles to generate a rat model bearing both granulomas and tumors (n = 6). Ten days after the inoculations, dynamic {sup 11}C-MET PET was performed by small animal PET up to 120 min after injection of {sup 11}C-MET. The next day, after overnight fasting, the rats were injected with {sup 18}F-2-deoxy-2-fluoro-D-glucose ({sup 18}F-FDG), and dynamic {sup 18}F-FDG PET was performed up to 180 min. The time-activity curves, static images, and mean standardized uptake value (SUV) in the lesions were calculated. {sup 11}C-MET uptake in the granuloma showed a slow exponential clearance after an initial distribution, while the uptake in the tumor gradually increased with time. The dynamic pattern of {sup 11}C-MET uptake in the granuloma was significantly different from that in the tumor (p < 0.001). In the static analysis of {sup 11}C-MET, visual assessment and SUV analysis could not differentiate the tumor from the granuloma in all cases, although the mean SUV in the granuloma (1.48 {+-} 0.09) was significantly lower than that in the tumor (1.72 {+-} 0.18, p < 0.01). The dynamic patterns, static images, and mean SUVs of {sup 18}F-FDG in the granuloma were similar to those in the tumor (p = NS). Dynamic {sup 11}C-MET PET has an additional value for differentiating malignant tumors from granulomatous lesions, which deserves further elucidation in clinical settings. (orig.)

  17. FDG PET/CT imaging as a biomarker in lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Meignan, Michel; Itti, Emmanuel [Hopitaux Universitaires Henri Mondor, Paris-Est Creteil University, LYSA Imaging, Department of Nuclear Medicine, Creteil (France); Gallamini, Andrea [Nice University, Research, Innovation and Statistic Department, Antoine Lacassagne Cancer Center, Nice (France); Scientific Research Committee, S. Croce Hospital, Cuneo (Italy); Younes, Anas [Memorial Sloan Kettering Cancer Center, Lymphoma Service, New York, NY (United States)

    2015-04-01

    FDG PET/CT has changed the management of FDG-avid lymphoma and is now recommended as the imaging technique of choice for staging and restaging. The need for tailoring therapy to reduce toxicity in patients with a favourable outcome and for improving treatment in those with high-risk factors requires accurate diagnostic methods and a new prognostic algorithm to identify different risk categories. New drugs are used in relapsed/refractory patients. The role of FDG PET/CT as a biomarker in this context is summarized in this review. New trends in FDG metabolic imaging in lymphoma are addressed including metabolic tumour volume measurement at staging and integrative PET which combines PET data with clinical and molecular markers or other imaging techniques. The quantitative approach for response assessment which is under investigation and is used in large ongoing trials is compared with visual criteria. The place of FDG in the era of targeted therapy is discussed. (orig.)

  18. Simultaneous MRI and PET imaging of a rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Raylman, Raymond R [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States); Majewski, Stan [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Lemieux, Susan K [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States); Velan, S Sendhil [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States); Kross, Brian [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Popov, Vladimir [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Smith, Mark F [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Weisenberger, Andrew G [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Zorn, Carl [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Marano, Gary D [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States)

    2006-12-21

    Multi-modality imaging is rapidly becoming a valuable tool in the diagnosis of disease and in the development of new drugs. Functional images produced with PET fused with anatomical structure images created by MRI will allow the correlation of form with function. Our group is developing a system to acquire MRI and PET images contemporaneously. The prototype device consists of two opposed detector heads, operating in coincidence mode. Each MRI-PET detector module consists of an array of LSO detector elements coupled through a long fibre optic light guide to a single Hamamatsu flat panel position-sensitive photomultiplier tube (PSPMT). The use of light guides allows the PSPMTs to be positioned outside the bore of a 3T MRI scanner where the magnetic field is relatively small. To test the device, simultaneous MRI and PET images of the brain of a male Sprague Dawley rat injected with FDG were successfully obtained. The images revealed no noticeable artefacts in either image set. Future work includes the construction of a full ring PET scanner, improved light guides and construction of a specialized MRI coil to permit higher quality MRI imaging.

  19. Quantitative Comparison of Y-90 and Ge-68 PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Sangkeun; Kwak, Shin Hye; Lee, Jeong A; Song, Han Kyeol; Kang, Joo Hyun; Lim, Sang Moo; KIm, Kyeong Min [Korea Institute of Raiological and Medical Sciences, Seoul (Korea, Republic of); Jeong, Su Young [Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of)

    2014-05-15

    The purpose of this study was to assess statistical characteristics and to improve count rate of image for enhancing Y-90 image quality by using non-parametric bootstrap method. The results showed that Y-90 PET image can be improved using non-parametric bootstrap method. PET data was able to be improved using non-parametric bootstrap method and it was verified with showing improved prompts rate. Y-90 PET image quality was improved and bias indicated that the bootstrapped image was more similar to the gold standard than other images. The non-parametric bootstrap method will be useful tool for enhancing Y-90 PET image and it will be expected to reduce time for acquisition and to elevate performance for diagnosis and treatment. Yttrium-90 (Y-90) radioembolization is one of the treatment methods unrespectable stage of hepatocellular carcinoma (HCC) and metastatic colon cancer to the liver. However, Y-90 radioembolization is a catheter-based therapy that delivers internal radiation to tumors, it results in greater radiation exposure to the tumors than using external radiation. Also, unlike other current therapies for the treatment of unresectable liver tumors, Y-90 radioembolization is much less often associated with toxicities such as abdominal pain, fever, nausea, and vomiting. Therefore Y-90 has been received much interest and studied by many researchers. Imaging of Y-90 has been conducted using most commonly gamma camera but quantitative PET imaging is required due to low sensitivity and resolution. Y-90 imaging is generally performed with SPECT by Bremsstrahlung photons. Unfortunately, the low image quality due to the nature of the Bremsstrahlung photon limits the quantitative accuracy of Y-90 SPECT. To overcome this limitation in SPECT imaging, Y-90 PET has been suggested as an alternative.

  20. Companion animal welfare and possible implications on the human-pet relationship

    OpenAIRE

    Marina Verga; Manuela Michelazzi

    2010-01-01

    The role of pets (dogs and cats in particular) in human society has changed in recent years. Nowadays pets are an integral part of the human family and this aspect has many social and emotional implications. For their positive effects on human health, pets are also employed in some special and therapeutic activities known by the generic term of “Pet Therapy”. In these programmes the animal becomes an integral part of the therapeutic plan in order to induce some physical, social, e...

  1. Imaging and PET-CT evaluation of Gi tract cancers

    International Nuclear Information System (INIS)

    Imaging plays a pivotal role in the management of G.I. tract cancers for diagnosis, characterization, locoregional staging, metastatic work-up and follow-up during and after curative or palliative treatment. The imaging protocols should be optimized and reproducible because of their impact on therapy. Thoracic, abdominal and pelvic CT is the cornerstone of the imaging work-up, optimized and reproducible because of their impact on therapy. Thoracic, abdominal and pelvic CT is the cornerstone of the imaging work-up, optimized and tailored to the specific G.I. segment involved, requiring good G.I. tract distension. Image interpretation of native axial and reformatted multiplanar images is routinely performed. In specific cases, additional targeted imaging with the US or MRI or whole body imaging with PET/CT or MRI may be valuable. PET/CT is a complement to morphological imaging. PET allows detection of lesions otherwise undetected on morphological imaging, usually due to poor contrast with surrounding tissues, and characterization of known lesions. PET/CT is best used as an integral part of a comprehensive imaging work-up. Radiologist and nuclear medicine specialists provide complementary information. each must be familiar with the clinical questions at hand and related stakes, and advantages and limitations of each modality to optimize treatment as part of a multidisciplinary management approach. (authors)

  2. PET Imaging of Integrin αVβ3 Expression

    Directory of Open Access Journals (Sweden)

    Ambros J. Beer, Horst Kessler, Hans-Jürgen Wester, Markus Schwaiger

    2011-01-01

    Full Text Available PET imaging of integrin αvβ3 expression has been studied intensely by the academia and recently also by the industry. Imaging of integrin αvβ3 expression is of great potential value, as the integrin αvβ3 is a key player in tumor metastasis and angiogenesis. Therefore PET imaging of this target might be a suitable in-vivo biomarker of angiogenesis and metastatic potential of tumors. In this manuscript, the various strategies for PET imaging of the integrin αvβ3 will be summarized, including monomeric and multimeric radiolabelled RGD peptides and nanoparticles. While most experiments have been performed using preclinical tumor models, more and more clinical results on PET imaging of αvβ3 expression are available and will be discussed in detail. However, while a multitude of radiotracer strategies have been successfully evaluated for PET imaging of αvβ3, the ultimate clinical value of this new imaging biomarker still has to be evaluated in large clinical trials.

  3. Spatial resolution recovery utilizing multi-ray tracing and graphic processing unit in PET image reconstruction

    International Nuclear Information System (INIS)

    Depth-of-interaction (DOI) poses a major challenge for a PET system to achieve uniform spatial resolution across the field-of-view, particularly for small animal and organ-dedicated PET systems. In this work, we implemented an analytical method to model system matrix for resolution recovery, which was then incorporated in PET image reconstruction on a graphical processing unit platform, due to its parallel processing capacity. The method utilizes the concepts of virtual DOI layers and multi-ray tracing to calculate the coincidence detection response function for a given line-of-response. The accuracy of the proposed method was validated for a small-bore PET insert to be used for simultaneous PET/MR breast imaging. In addition, the performance comparisons were studied among the following three cases: 1) no physical DOI and no resolution modeling; 2) two physical DOI layers and no resolution modeling; and 3) no physical DOI design but with a different number of virtual DOI layers. The image quality was quantitatively evaluated in terms of spatial resolution (full-width-half-maximum and position offset), contrast recovery coefficient and noise. The results indicate that the proposed method has the potential to be used as an alternative to other physical DOI designs and achieve comparable imaging performances, while reducing detector/system design cost and complexity. (paper)

  4. Spatial resolution recovery utilizing multi-ray tracing and graphic processing unit in PET image reconstruction

    Science.gov (United States)

    Liang, Yicheng; Peng, Hao

    2015-02-01

    Depth-of-interaction (DOI) poses a major challenge for a PET system to achieve uniform spatial resolution across the field-of-view, particularly for small animal and organ-dedicated PET systems. In this work, we implemented an analytical method to model system matrix for resolution recovery, which was then incorporated in PET image reconstruction on a graphical processing unit platform, due to its parallel processing capacity. The method utilizes the concepts of virtual DOI layers and multi-ray tracing to calculate the coincidence detection response function for a given line-of-response. The accuracy of the proposed method was validated for a small-bore PET insert to be used for simultaneous PET/MR breast imaging. In addition, the performance comparisons were studied among the following three cases: 1) no physical DOI and no resolution modeling; 2) two physical DOI layers and no resolution modeling; and 3) no physical DOI design but with a different number of virtual DOI layers. The image quality was quantitatively evaluated in terms of spatial resolution (full-width-half-maximum and position offset), contrast recovery coefficient and noise. The results indicate that the proposed method has the potential to be used as an alternative to other physical DOI designs and achieve comparable imaging performances, while reducing detector/system design cost and complexity.

  5. Imaging with {sup 124}I in differentiated thyroid carcinoma: is PET/MRI superior to PET/CT?

    Energy Technology Data Exchange (ETDEWEB)

    Binse, I.; Poeppel, T.D.; Ruhlmann, M.; Gomez, B.; Bockisch, A.; Rosenbaum-Krumme, S.J. [University of Duisburg-Essen, Medical Faculty, Department of Nuclear Medicine, Essen (Germany); Umutlu, L. [University of Duisburg-Essen, Medical Faculty, Department of Radiology, Essen (Germany)

    2016-06-15

    The aim of this study was to compare integrated PET/CT and PET/MRI for their usefulness in detecting and categorizing cervical iodine-positive lesions in patients with differentiated thyroid cancer using {sup 124}I as tracer. The study group comprised 65 patients at high risk of iodine-positive metastasis who underwent PET/CT (low-dose CT scan, PET acquisition time 2 min; PET/CT{sub 2}) followed by PET/MRI of the neck 24 h after {sup 124}I administration. PET images from both modalities were analysed for the numbers of tracer-positive lesions. Two different acquisition times were used for the comparisons, one matching the PET/CT{sub 2} acquisition time (2 min, PET/MRI{sub 2}) and the other covering the whole MRI scan time (30 min, PET/MRI{sub 30}). Iodine-positive lesions were categorized as metastasis, thyroid remnant or inconclusive according to their location on the PET/CT images. Morphological information provided by MRI was considered for evaluation of lesions on PET/MRI and for volume information. PET/MRI{sub 2} detected significantly more iodine-positive metastases and thyroid remnants than PET/CT{sub 2} (72 vs. 60, p = 0.002, and 100 vs. 80, p = 0.001, respectively), but the numbers of patients with at least one tumour lesion identified were not significantly different (21/65 vs. 17/65 patients). PET/MRI{sub 30} tended to detect more PET-positive metastases than PET/MRI{sub 2} (88 vs. 72), but the difference was not significant (p = 0.07). Of 21 lesions classified as inconclusive on PET/CT, 5 were assigned to metastasis or thyroid remnant when evaluated by PET/MRI. Volume information was available in 34 % of iodine-positive metastases and 2 % of thyroid remnants on PET/MRI. PET/MRI of the neck was found to be superior to PET/CT in detecting iodine-positive lesions. This was attributed to the higher sensitivity of the PET component, Although helpful in some cases, we found no substantial advantage of PET/MRI over PET/CT in categorizing iodine

  6. Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part II. In Vivo Imaging of Bone Marrow Stromal Cells in Swine with PET/CT and MR Imaging.

    Science.gov (United States)

    Parashurama, Natesh; Ahn, Byeong-Cheol; Ziv, Keren; Ito, Ken; Paulmurugan, Ramasamy; Willmann, Jürgen K; Chung, Jaehoon; Ikeno, Fumiaki; Swanson, Julia C; Merk, Denis R; Lyons, Jennifer K; Yerushalmi, David; Teramoto, Tomohiko; Kosuge, Hisanori; Dao, Catherine N; Ray, Pritha; Patel, Manishkumar; Chang, Ya-Fang; Mahmoudi, Morteza; Cohen, Jeff Eric; Goldstone, Andrew Brooks; Habte, Frezghi; Bhaumik, Srabani; Yaghoubi, Shahriar; Robbins, Robert C; Dash, Rajesh; Yang, Phillip C; Brinton, Todd J; Yock, Paul G; McConnell, Michael V; Gambhir, Sanjiv S

    2016-09-01

    Purpose To quantitatively determine the limit of detection of marrow stromal cells (MSC) after cardiac cell therapy (CCT) in swine by using clinical positron emission tomography (PET) reporter gene imaging and magnetic resonance (MR) imaging with cell prelabeling. Materials and Methods Animal studies were approved by the institutional administrative panel on laboratory animal care. Seven swine received 23 intracardiac cell injections that contained control MSC and cell mixtures of MSC expressing a multimodality triple fusion (TF) reporter gene (MSC-TF) and bearing superparamagnetic iron oxide nanoparticles (NP) (MSC-TF-NP) or NP alone. Clinical MR imaging and PET reporter gene molecular imaging were performed after intravenous injection of the radiotracer fluorine 18-radiolabeled 9-[4-fluoro-3-(hydroxyl methyl) butyl] guanine ((18)F-FHBG). Linear regression analysis of both MR imaging and PET data and nonlinear regression analysis of PET data were performed, accounting for multiple injections per animal. Results MR imaging showed a positive correlation between MSC-TF-NP cell number and dephasing (dark) signal (R(2) = 0.72, P = .0001) and a lower detection limit of at least approximately 1.5 × 10(7) cells. PET reporter gene imaging demonstrated a significant positive correlation between MSC-TF and target-to-background ratio with the linear model (R(2) = 0.88, P = .0001, root mean square error = 0.523) and the nonlinear model (R(2) = 0.99, P = .0001, root mean square error = 0.273) and a lower detection limit of 2.5 × 10(8) cells. Conclusion The authors quantitatively determined the limit of detection of MSC after CCT in swine by using clinical PET reporter gene imaging and clinical MR imaging with cell prelabeling. (©) RSNA, 2016 Online supplemental material is available for this article. PMID:27332865

  7. FDG PET/CT imaging in canine cancer patients

    DEFF Research Database (Denmark)

    Hansen, Anders Elias; McEvoy, Fintan; Engelholm, Svend Aage;

    2011-01-01

    and organs in canine cancer patients. FDG PET/CT was performed in 14 dogs including, nine mesenchymal tumors, four carcinomas, and one incompletely excised mast cell tumor. A generally higher FDG uptake was observed in carcinomas relative to sarcomas. Maximum SUV of carcinomas ranged from 7.6 to 27.......0, and for sarcomas from 2.0 to 10.6. The FDG SUV of several organs and tissues, including regional brain uptake is reported, to serve as a reference for future FDG PET studies in canine cancer patients. Several potential pitfalls have been recognized in interpretation of FDG PET images of human patients, a number...

  8. Atlas of PET/MR imaging in oncology

    Energy Technology Data Exchange (ETDEWEB)

    Ratib, Osman [University Hospital of Geneva (Switzerland). Nuclear Medicine Division; Schwaiger, Markus [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik und Poliklinik; Beyer, Thomas (eds.) [General Hospital Vienna (Austria). Center for Medical Physics and Biomedical Engineering

    2013-08-01

    Numerous illustrated clinical cases in different oncology domains. Includes digital interactive software matching the cases in the book. Interactive version based on the latest web standard, HTML5, ensuring the widest compatibility. Edited by three international opinion leaders/imaging experts in the field. This new project on PET/MR imaging in oncology includes digital interactive software matching the cases in the book. The interactive version of the atlas is based on the latest web standard, HTML5, ensuring compatibility with any computer operating system as well as a dedicated version for Apple iPad and iPhone. The book opens with an introduction to the principles of hybrid imaging that pays particular attention to PET/MR imaging and standard PET/MR acquisition protocols. A wide range of illustrated clinical case reports are then presented. Each case study includes a short clinical history, findings, and teaching points, followed by illustrations, legends, and comments. The multimedia version of the book includes dynamic movies that allow the reader to browse through series of rotating 3D images (MIP or volume rendered), display blending between PET and MR, and dynamic visualization of 3D image volumes. The movies can be played either continuously or sequentially for better exploration of sets of images. The editors of this state-of-the-art publication are key opinion leaders in the field of multimodality imaging. Professor Osman Ratib (Geneva) and Professor Markus Schwaiger (Munich) were the first in Europe to initiate the clinical adoption of PET/MR imaging. Professor Thomas Beyer (Zurich) is an internationally renowned pioneering physicist in the field of hybrid imaging. Individual clinical cases presented in this book are co-authored by leading international radiologists and nuclear physicians experts in the use of PET and MRI.

  9. Validation of a small-animal PET simulation using GAMOS: a GEANT4-based framework.

    Science.gov (United States)

    Cañadas, M; Arce, P; Rato Mendes, P

    2011-01-01

    Monte Carlo-based modelling is a powerful tool to help in the design and optimization of positron emission tomography (PET) systems. The performance of these systems depends on several parameters, such as detector physical characteristics, shielding or electronics, whose effects can be studied on the basis of realistic simulated data. The aim of this paper is to validate a comprehensive study of the Raytest ClearPET small-animal PET scanner using a new Monte Carlo simulation platform which has been developed at CIEMAT (Madrid, Spain), called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations). This toolkit, based on the GEANT4 code, was originally designed to cover multiple applications in the field of medical physics from radiotherapy to nuclear medicine, but has since been applied by some of its users in other fields of physics, such as neutron shielding, space physics, high energy physics, etc. Our simulation model includes the relevant characteristics of the ClearPET system, namely, the double layer of scintillator crystals in phoswich configuration, the rotating gantry, the presence of intrinsic radioactivity in the crystals or the storage of single events for an off-line coincidence sorting. Simulated results are contrasted with experimental acquisitions including studies of spatial resolution, sensitivity, scatter fraction and count rates in accordance with the National Electrical Manufacturers Association (NEMA) NU 4-2008 protocol. Spatial resolution results showed a discrepancy between simulated and measured values equal to 8.4% (with a maximum FWHM difference over all measurement directions of 0.5 mm). Sensitivity results differ less than 1% for a 250-750 keV energy window. Simulated and measured count rates agree well within a wide range of activities, including under electronic saturation of the system (the measured peak of total coincidences, for the mouse-sized phantom, was 250.8 kcps reached at 0.95 MBq mL(-1) and the simulated peak

  10. Validation of a small-animal PET simulation using GAMOS: a GEANT4-based framework

    Science.gov (United States)

    Cañadas, M.; Arce, P.; Rato Mendes, P.

    2011-01-01

    Monte Carlo-based modelling is a powerful tool to help in the design and optimization of positron emission tomography (PET) systems. The performance of these systems depends on several parameters, such as detector physical characteristics, shielding or electronics, whose effects can be studied on the basis of realistic simulated data. The aim of this paper is to validate a comprehensive study of the Raytest ClearPET small-animal PET scanner using a new Monte Carlo simulation platform which has been developed at CIEMAT (Madrid, Spain), called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations). This toolkit, based on the GEANT4 code, was originally designed to cover multiple applications in the field of medical physics from radiotherapy to nuclear medicine, but has since been applied by some of its users in other fields of physics, such as neutron shielding, space physics, high energy physics, etc. Our simulation model includes the relevant characteristics of the ClearPET system, namely, the double layer of scintillator crystals in phoswich configuration, the rotating gantry, the presence of intrinsic radioactivity in the crystals or the storage of single events for an off-line coincidence sorting. Simulated results are contrasted with experimental acquisitions including studies of spatial resolution, sensitivity, scatter fraction and count rates in accordance with the National Electrical Manufacturers Association (NEMA) NU 4-2008 protocol. Spatial resolution results showed a discrepancy between simulated and measured values equal to 8.4% (with a maximum FWHM difference over all measurement directions of 0.5 mm). Sensitivity results differ less than 1% for a 250-750 keV energy window. Simulated and measured count rates agree well within a wide range of activities, including under electronic saturation of the system (the measured peak of total coincidences, for the mouse-sized phantom, was 250.8 kcps reached at 0.95 MBq mL-1 and the simulated peak was

  11. Bayesian PET image reconstruction incorporating anato-functional joint entropy

    Science.gov (United States)

    Tang, Jing; Rahmim, Arman

    2009-12-01

    We developed a maximum a posterior (MAP) reconstruction method for positron emission tomography (PET) image reconstruction incorporating magnetic resonance (MR) image information, with the joint entropy between the PET and MR image features serving as the regularization constraint. A non-parametric method was used to estimate the joint probability density of the PET and MR images. Using realistically simulated PET and MR human brain phantoms, the quantitative performance of the proposed algorithm was investigated. Incorporation of the anatomic information via this technique, after parameter optimization, was seen to dramatically improve the noise versus bias tradeoff in every region of interest, compared to the result from using conventional MAP reconstruction. In particular, hot lesions in the FDG PET image, which had no anatomical correspondence in the MR image, also had improved contrast versus noise tradeoff. Corrections were made to figures 3, 4 and 6, and to the second paragraph of section 3.1 on 13 November 2009. The corrected electronic version is identical to the print version.

  12. Compact and mobile high resolution PET brain imager

    Science.gov (United States)

    Majewski, Stanislaw; Proffitt, James

    2011-02-08

    A brain imager includes a compact ring-like static PET imager mounted in a helmet-like structure. When attached to a patient's head, the helmet-like brain imager maintains the relative head-to-imager geometry fixed through the whole imaging procedure. The brain imaging helmet contains radiation sensors and minimal front-end electronics. A flexible mechanical suspension/harness system supports the weight of the helmet thereby allowing for patient to have limited movements of the head during imaging scans. The compact ring-like PET imager enables very high resolution imaging of neurological brain functions, cancer, and effects of trauma using a rather simple mobile scanner with limited space needs for use and storage.

  13. Complicated grief and posttraumatic stress disorder in humans' response to the death of pets/animals.

    Science.gov (United States)

    Adrian, Julie A Luiz; Deliramich, Aimee N; Frueh, B Christopher

    2009-01-01

    The present exploratory project represents a cross-sectional study designed to determine the percentage of people reporting significant symptoms of complicated grief (CG) and/or posttraumatic stress disorder (PTSD) in response to the death of companion pets/animals. Human participants (N = 106) were sampled from a veterinary clinic. Fifty-two percent of participants had lost one to three pets from natural causes, 60% had never lost a pet to euthanasia, and 37% had lost one to three pets to euthanasia. The study suggests that many people experience significant attachment to their pets/animals and experience significant features of grief reactions (about 20%) after the death of a pet/animal. However, the percentage of people experiencing major pathological disruption is relatively low (pets/animals and last 6 months or more for about 30% of those sampled. Severe pathological reactions do occur but are quite rare among human survivors. Implications for mental health clinicians working with affected populations are discussed. PMID:19807222

  14. Fusion of PET and MRI for Hybrid Imaging

    Science.gov (United States)

    Cho, Zang-Hee; Son, Young-Don; Kim, Young-Bo; Yoo, Seung-Schik

    Recently, the development of the fusion PET-MRI system has been actively studied to meet the increasing demand for integrated molecular and anatomical imaging. MRI can provide detailed anatomical information on the brain, such as the locations of gray and white matter, blood vessels, axonal tracts with high resolution, while PET can measure molecular and genetic information, such as glucose metabolism, neurotransmitter-neuroreceptor binding and affinity, protein-protein interactions, and gene trafficking among biological tissues. State-of-the-art MRI systems, such as the 7.0 T whole-body MRI, now can visualize super-fine structures including neuronal bundles in the pons, fine blood vessels (such as lenticulostriate arteries) without invasive contrast agents, in vivo hippocampal substructures, and substantia nigra with excellent image contrast. High-resolution PET, known as High-Resolution Research Tomograph (HRRT), is a brain-dedicated system capable of imaging minute changes of chemicals, such as neurotransmitters and -receptors, with high spatial resolution and sensitivity. The synergistic power of the two, i.e., ultra high-resolution anatomical information offered by a 7.0 T MRI system combined with the high-sensitivity molecular information offered by HRRT-PET, will significantly elevate the level of our current understanding of the human brain, one of the most delicate, complex, and mysterious biological organs. This chapter introduces MRI, PET, and PET-MRI fusion system, and its algorithms are discussed in detail.

  15. Improved dead-time correction for PET scanners: application to small-animal PET

    International Nuclear Information System (INIS)

    Pile-up and dead-time are two main causes of nonlinearity in the response of a PET scanner as a function of activity in the field of view (FOV). For a given scanner and acquisition system, pile-up effects depend on the material and size of the object being imaged and on the distribution of activity inside and outside the FOV, because these factors change the singles-to-coincidences ratio (SCR). Thus, it is difficult to devise an accurate correction that would be valid for any acquisition. In this work, we demonstrate a linear relationship between SCR and effective dead-time, which measures the effects of both dead-time (losses) and pile-up (gains and losses). This relationship allows us to propose a simple method to accurately estimate dead-time and pile-up corrections using only two calibration acquisitions with, respectively, a high and low SCR. The method has been tested with simulations and experimental data for two different scanner geometries: a scanner with large area detectors and no pile-up rejection, and a scanner composed of two full rings of smaller detectors. Our results show that the SCR correction method is accurate within 7%, even for high activities in the FOV, and avoids the bias of the standard single-parameter method. (paper)

  16. Improved dead-time correction for PET scanners: application to small-animal PET

    Science.gov (United States)

    Vicente, E.; Herraiz, J. L.; España, S.; Herranz, E.; Desco, M.; Vaquero, J. J.; Udías, J. M.

    2013-04-01

    Pile-up and dead-time are two main causes of nonlinearity in the response of a PET scanner as a function of activity in the field of view (FOV). For a given scanner and acquisition system, pile-up effects depend on the material and size of the object being imaged and on the distribution of activity inside and outside the FOV, because these factors change the singles-to-coincidences ratio (SCR). Thus, it is difficult to devise an accurate correction that would be valid for any acquisition. In this work, we demonstrate a linear relationship between SCR and effective dead-time, which measures the effects of both dead-time (losses) and pile-up (gains and losses). This relationship allows us to propose a simple method to accurately estimate dead-time and pile-up corrections using only two calibration acquisitions with, respectively, a high and low SCR. The method has been tested with simulations and experimental data for two different scanner geometries: a scanner with large area detectors and no pile-up rejection, and a scanner composed of two full rings of smaller detectors. Our results show that the SCR correction method is accurate within 7%, even for high activities in the FOV, and avoids the bias of the standard single-parameter method.

  17. Mass effect of injected dose in small rodent imaging by SPECT and PET

    Energy Technology Data Exchange (ETDEWEB)

    Kung, M.-P. [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kung, Hank F. [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States) and Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104 (United States)]. E-mail: kunghf@sunmac.spect.upenn.edu

    2005-10-01

    This paper discusses the effect of mass (chemical quantity) of injected dose on positron emission tomography (PET) and single-photon emission computed tomography (SPECT). Commonly, PET or SPECT imaging study uses a 'no-carrier added' dose, which contains a small amount of radioactive imaging agent (in picogram to microgram). For small animal (rodent) imaging studies, specifically targeting binding sites or biological processes, the mass (chemical quantity) in the dose may significantly modify the binding, pharmacokinetics and, ultimately, the imaging outcome. Due to differences in size and other physiological factors between humans and rodents, there is a dramatic divergence of mass effect between small animal and human imaging study. In small animal imaging studies, the mass, or effective dose (ED{sub 50}), a dose required for 50% of receptor or binding site occupancy, is usually not directly related to binding potential (B {sub max}/K {sub d}) (measured by in vitro binding assay). It is likely that dynamic interplays between specific and nonspecific binding in blood circulation, transient lung retention, kidney excretion, liver-gallbladder flow, soft tissue retention as well as metabolism could each play a significant role in determining the concentration of the tracer in the target regions. When using small animal imaging for studying drug occupancy (either by a pretreatment, coinjection or chasing dose), the mass effects on imaging outcome are important factors for consideration.

  18. The Benefit of Pets and Animal-Assisted Therapy to the Health of Older Individuals

    OpenAIRE

    E. Paul Cherniack; Cherniack, Ariella R.

    2014-01-01

    Many studies utilizing dogs, cats, birds, fish, and robotic simulations of animals have tried to ascertain the health benefits of pet ownership or animal-assisted therapy in the elderly. Several small unblinded investigations outlined improvements in behavior in demented persons given treatment in the presence of animals. Studies piloting the use of animals in the treatment of depression and schizophrenia have yielded mixed results. Animals may provide intangible benefits to the mental health...

  19. Rapid intracerebroventricular delivery of Cu-DOTA-etanercept after peripheral administration demonstrated by PET imaging

    Directory of Open Access Journals (Sweden)

    Chen Xiaoyuan

    2009-02-01

    Full Text Available Abstract Background The cytokines interleukin-1 and tumor necrosis factor (TNF, and the cytokine blocker interleukin-1 receptor antagonist, all have been demonstrated to enter the cerebrospinal fluid (CSF following peripheral administration. Recent reports of rapid clinical improvement in patients with Alzheimer's disease and related forms of dementia following perispinal administration of etanercept, a TNF antagonist, suggest that etanercept also has the ability to reach the brain CSF. To investigate, etanercept was labeled with a positron emitter to enable visualization of its intracranial distribution following peripheral administration by PET in an animal model. Findings Radiolabeling of etanercept with the PET emitter 64Cu was performed by DOTA (1,4,7,10-tetraazadodecane-N,N',N",N"'-tetraacetic acid conjugation of etanercept, followed by column purification and 64Cu labeling. MicroPET imaging revealed accumulation of 64Cu-DOTA-etanercept within the lateral and third cerebral ventricles within minutes of peripheral perispinal administration in a normal rat anesthesized with isoflurane anesthesia, with concentration within the choroid plexus and into the CSF. Conclusion Synthesis of 64Cu-DOTA-etanercept enabled visualization of its intracranial distribution by microPET imaging. MicroPET imaging documented rapid accumulation of 64Cu-DOTA-etanercept within the choroid plexus and the cerebrospinal fluid within the cerebral ventricles of a living rat after peripheral administration. Further study of the effects of etanercept and TNF at the level of the choroid plexus may yield valuable insights into the pathogenesis of Alzheimer's disease.

  20. PET/MR imaging of bone lesions - implications for PET quantification from imperfect attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Samarin, Andrei [University Hospital of Zurich, Department of Medical Radiology, Zurich (Switzerland); University Hospital Zurich, Nuclear Medicine, Zurich (Switzerland); Burger, Cyrill; Crook, David W.; Burger, Irene A.; Schmid, Daniel T.; Schulthess, Gustav K. von; Kuhn, Felix P. [University Hospital of Zurich, Department of Medical Radiology, Zurich (Switzerland); Wollenweber, Scott D. [GE Healthcare, Waukesha, WI (United States)

    2012-07-15

    Accurate attenuation correction (AC) is essential for quantitative analysis of PET tracer distribution. In MR, the lack of cortical bone signal makes bone segmentation difficult and may require implementation of special sequences. The purpose of this study was to evaluate the need for accurate bone segmentation in MR-based AC for whole-body PET/MR imaging. In 22 patients undergoing sequential PET/CT and 3-T MR imaging, modified CT AC maps were produced by replacing pixels with values of >100 HU, representing mostly bone structures, by pixels with a constant value of 36 HU corresponding to soft tissue, thereby simulating current MR-derived AC maps. A total of 141 FDG-positive osseous lesions and 50 soft-tissue lesions adjacent to bones were evaluated. The mean standardized uptake value (SUVmean) was measured in each lesion in PET images reconstructed once using the standard AC maps and once using the modified AC maps. Subsequently, the errors in lesion tracer uptake for the modified PET images were calculated using the standard PET image as a reference. Substitution of bone by soft tissue values in AC maps resulted in an underestimation of tracer uptake in osseous and soft tissue lesions adjacent to bones of 11.2 {+-} 5.4 % (range 1.5-30.8 %) and 3.2 {+-} 1.7 % (range 0.2-4 %), respectively. Analysis of the spine and pelvic osseous lesions revealed a substantial dependence of the error on lesion composition. For predominantly sclerotic spine lesions, the mean underestimation was 15.9 {+-} 3.4 % (range 9.9-23.5 %) and for osteolytic spine lesions, 7.2 {+-} 1.7 % (range 4.9-9.3 %), respectively. CT data simulating treating bone as soft tissue as is currently done in MR maps for PET AC leads to a substantial underestimation of tracer uptake in bone lesions and depends on lesion composition, the largest error being seen in sclerotic lesions. Therefore, depiction of cortical bone and other calcified areas in MR AC maps is necessary for accurate quantification of tracer

  1. PET/CT imaging in lung cancer: indications and findings

    Directory of Open Access Journals (Sweden)

    Bruno Hochhegger

    2015-06-01

    Full Text Available The use of PET/CT imaging in the work-up and management of patients with lung cancer has greatly increased in recent decades. The ability to combine functional and anatomical information has equipped PET/CT to look into various aspects of lung cancer, allowing more precise disease staging and providing useful data during the characterization of indeterminate pulmonary nodules. In addition, the accuracy of PET/CT has been shown to be greater than is that of conventional modalities in some scenarios, making PET/CT a valuable noninvasive method for the investigation of lung cancer. However, the interpretation of PET/CT findings presents numerous pitfalls and potential confounders. Therefore, it is imperative for pulmonologists and radiologists to familiarize themselves with the most relevant indications for and limitations of PET/CT, seeking to protect their patients from unnecessary radiation exposure and inappropriate treatment. This review article aimed to summarize the basic principles, indications, cancer staging considerations, and future applications related to the use of PET/CT in lung cancer.

  2. Healthy animals, healthy people: zoonosis risk from animal contact in pet shops, a systematic review of the literature.

    Directory of Open Access Journals (Sweden)

    Kate D Halsby

    Full Text Available BACKGROUND: Around 67 million pets are owned by households in the United Kingdom, and an increasing number of these are exotic animals. Approximately a third of pets are purchased through retail outlets or direct from breeders. A wide range of infections can be associated with companion animals. OBJECTIVES: This study uses a systematic literature review to describe the transmission of zoonotic disease in humans associated with a pet shop or other location selling pets (incidents of rabies tracebacks and zoonoses from pet food were excluded. DATA SOURCES: PubMed and EMBASE. RESULTS: Fifty seven separate case reports or incidents were described in the 82 papers that were identified by the systematic review. Summary information on each incident is included in this manuscript. The infections include bacterial, viral and fungal diseases and range in severity from mild to life threatening. Infections associated with birds and rodents were the most commonly reported. Over half of the reports describe incidents in the Americas, and three of these were outbreaks involving more than 50 cases. Many of the incidents identified relate to infections in pet shop employees. LIMITATIONS: This review may have been subject to publication bias, where unusual and unexpected zoonotic infections may be over-represented in peer-reviewed publications. It was also restricted to English-language articles so that pathogens that are more common in non-Western countries, or in more exotic animals not common in Europe and the Americas, may have been under-represented. CONCLUSIONS/IMPLICATIONS: A wide spectrum of zoonotic infections are acquired from pet shops. Salmonellosis and psittacosis were the most commonly documented diseases, however more unusual infections such as tularemia also appeared in the review. Given their potential to spread zoonotic infection, it is important that pet shops act to minimise the risk as far as possible.

  3. Jet set pets: examining the zoonosis risk in animal import and travel across the European Union

    Directory of Open Access Journals (Sweden)

    Fooks AR

    2014-12-01

    Full Text Available Anthony R Fooks,1,2 Nicholas Johnson1 1Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Addlestone, Surrey, 2Department of Clinical Infection, University of Liverpool, Liverpool, UK Abstract: Ownership of companion animals or pets is popular throughout the world. Unfortunately, such animals are susceptible to and potential reservoirs of zoonotic pathogens. Close proximity to and contact with pets can lead to human infections. The distribution of zoonotic diseases associated with companion animals such as dogs and cats is not uniform around the world, and moving animals between regions, countries, and continents carries with it the risk of relocating the pathogens they might harbor. Critical among these zoonotic diseases are rabies, echinococcosis, and leishmania. In addition, the protozoan parasites, Toxoplasma gondii and Giardia duodenalis, are also significant agents for human disease of pet origin. Considerable effort is applied to controlling movements of companion animals, particularly dogs, into the European Union. However, free movement of people and their pets within the European Union is a risk factor for the translocation of diseases and their vectors. This review considers the current distribution of some of these diseases, the risks associated with pet travel, and the controls implemented within Europe to prevent the free movement of zoonotic pathogens. Keywords: zoonosis, companion animal, rabies, alveolar echinococcosis, leishmania

  4. PET/SPECT imaging: From carotid vulnerability to brain viability

    Energy Technology Data Exchange (ETDEWEB)

    Meerwaldt, Robbert [Department of Surgery, Isala Clinics, Zwolle (Netherlands); Slart, Riemer H.J.A. [Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Dam, Gooitzen M. van [Department of Surgery, University Medical Center Groningen, Groningen (Netherlands); Luijckx, Gert-Jan [Department of Neurology, University Medical Center Groningen, Groningen (Netherlands); Tio, Rene A. [Department of Cardiology, University Medical Center Groningen, Groningen (Netherlands); Zeebregts, Clark J. [Department of Surgery, University Medical Center Groningen, Groningen (Netherlands)], E-mail: czeebregts@hotmail.com

    2010-04-15

    Background: Current key issues in ischemic stroke are related to carotid plaque vulnerability, brain viability, and timing of intervention. The treatment of ischemic stroke has evolved into urgent active interventions, as 'time is brain'. Functional imaging such as positron emission tomography (PET)/single photon emission computed tomography (SPECT) could improve selection of patients with a vulnerable plaque and evaluation of brain viability in ischemic stroke. Objective: To describe the current applications of PET and SPECT as a diagnostic tool in relation to ischemic stroke. Methods: A literature search using PubMed identified articles. Manual cross-referencing was also performed. Results: Several papers, all observational studies, identified PET/SPECT to be used as a tool to monitor systemic atheroma modifying treatment and to select high-risk patients for surgery regardless of the degree of luminal stenosis in carotid lesions. Furthermore, PET/SPECT is able to quantify the penumbra region during ischemic stroke and in this way may identify those patients who may benefit from timely intervention. Discussion: Functional imaging modalities such as PET/SPECT may become important tools for risk-assessment and evaluation of treatment strategies in carotid plaque vulnerability and brain viability. Prospective clinical studies are needed to evaluate the diagnostic accuracy of PET/SPECT.

  5. Monitoring proton radiation therapy with in-room PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Xuping; Ouyang Jinsong; El Fakhri, Georges [Department of Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114 (United States); Espana, Samuel; Daartz, Juliane; Liebsch, Norbert; Paganetti, Harald; Bortfeld, Thomas R, E-mail: elfakhri@pet.mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114 (United States)

    2011-07-07

    We used a mobile positron emission tomography (PET) scanner positioned within the proton therapy treatment room to study the feasibility of proton range verification with an in-room, stand-alone PET system, and compared with off-line equivalent studies. Two subjects with adenoid cystic carcinoma were enrolled into a pilot study in which in-room PET scans were acquired in list-mode after a routine fractionated treatment session. The list-mode PET data were reconstructed with different time schemes to generate in-room short, in-room long and off-line equivalent (by skipping coincidences from the first 15 min during the list-mode reconstruction) PET images for comparison in activity distribution patterns. A phantom study was followed to evaluate the accuracy of range verification for different reconstruction time schemes quantitatively. The in-room PET has a higher sensitivity compared to the off-line modality so that the PET acquisition time can be greatly reduced from 30 to <5 min. Features in deep-site, soft-tissue regions were better retained with in-room short PET acquisitions because of the collection of {sup 15}O component and lower biological washout. For soft tissue-equivalent material, the distal fall-off edge of an in-room short acquisition is deeper compared to an off-line equivalent scan, indicating a better coverage of the high-dose end of the beam. In-room PET is a promising low cost, high sensitivity modality for the in vivo verification of proton therapy. Better accuracy in Monte Carlo predictions, especially for biological decay modeling, is necessary.

  6. Development of a simultaneous optical/PET imaging system for awake mice

    Science.gov (United States)

    Takuwa, Hiroyuki; Ikoma, Yoko; Yoshida, Eiji; Tashima, Hideaki; Wakizaka, Hidekatsu; Shinaji, Tetsuya; Yamaya, Taiga

    2016-09-01

    Simultaneous measurements of multiple physiological parameters are essential for the study of brain disease mechanisms and the development of suitable therapies to treat them. In this study, we developed a measurement system for simultaneous optical imaging and PET for awake mice. The key elements of this system are the OpenPET, optical imaging and fixation apparatus for an awake mouse. The OpenPET is our original open-type PET geometry, which can be used in combination with another device because of the easily accessible open space of the former. A small prototype of the axial shift single-ring OpenPET was used. The objective lens for optical imaging with a mounted charge-coupled device camera was placed inside the open space of the AS-SROP. Our original fixation apparatus to hold an awake mouse was also applied. As a first application of this system, simultaneous measurements of cerebral blood flow (CBF) by laser speckle imaging (LSI) and [11C]raclopride-PET were performed under control and 5% CO2 inhalation (hypercapnia) conditions. Our system successfully obtained the CBF and [11C]raclopride radioactivity concentration simultaneously. Accumulation of [11C]raclopride was observed in the striatum where the density of dopamine D2 receptors is high. LSI measurements could be stably performed for more than 60 minutes. Increased CBF induced by hypercapnia was observed while CBF under the control condition was stable. We concluded that our imaging system should be useful for investigating the mechanisms of brain diseases in awake animal models.

  7. Development of a simultaneous optical/PET imaging system for awake mice.

    Science.gov (United States)

    Takuwa, Hiroyuki; Ikoma, Yoko; Yoshida, Eiji; Tashima, Hideaki; Wakizaka, Hidekatsu; Shinaji, Tetsuya; Yamaya, Taiga

    2016-09-01

    Simultaneous measurements of multiple physiological parameters are essential for the study of brain disease mechanisms and the development of suitable therapies to treat them. In this study, we developed a measurement system for simultaneous optical imaging and PET for awake mice. The key elements of this system are the OpenPET, optical imaging and fixation apparatus for an awake mouse. The OpenPET is our original open-type PET geometry, which can be used in combination with another device because of the easily accessible open space of the former. A small prototype of the axial shift single-ring OpenPET was used. The objective lens for optical imaging with a mounted charge-coupled device camera was placed inside the open space of the AS-SROP. Our original fixation apparatus to hold an awake mouse was also applied. As a first application of this system, simultaneous measurements of cerebral blood flow (CBF) by laser speckle imaging (LSI) and [(11)C]raclopride-PET were performed under control and 5% CO2 inhalation (hypercapnia) conditions. Our system successfully obtained the CBF and [(11)C]raclopride radioactivity concentration simultaneously. Accumulation of [(11)C]raclopride was observed in the striatum where the density of dopamine D2 receptors is high. LSI measurements could be stably performed for more than 60 minutes. Increased CBF induced by hypercapnia was observed while CBF under the control condition was stable. We concluded that our imaging system should be useful for investigating the mechanisms of brain diseases in awake animal models. PMID:27514436

  8. Development of Input Function Measurement System for Small Animal PET Study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Guk; Kim, Byung Su; Kim, Jin Su [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2010-10-15

    For quantitative measurement of radioactivity concentration in tissue and a validated tracer kinetic model, the high sensitive detection system has been required for blood sampling. With the accurate measurement of time activity curves (TACs) of labeled compounds in blood (plasma) enable to provide quantitative information on biological parameters of interest in local tissue. Especially, the development of new tracers for PET imaging requires knowledge of the kinetics of the tracer in the body and in arterial blood and plasma. Conventional approaches of obtaining an input function are to sample arterial blood sequentially by manual as a function of time. Several continuous blood sampling systems have been developed and used in nuclear medicine research field to overcome the limited temporal resolution in sampling by the conventional method. In this work, we developed the high sensitive and unique geometric design of GSO detector for small animal blood activity measurement

  9. Importance of PET/CT for imaging of colorectal cancer; Stellenwert der PET/CT zur Bildgebung des kolorektalen Karzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Meinel, F.G.; Schramm, N.; Graser, A.; Reiser, M.F.; Rist, C. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany); Haug, A.R. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Klinik und Poliklinik fuer Nuklearmedizin, Muenchen (Germany)

    2012-06-15

    Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has emerged as a very useful imaging modality in the management of colorectal carcinoma. Data from the literature regarding the role of PET/CT in the initial diagnosis, staging, radiotherapy planning, response monitoring and surveillance of colorectal carcinoma is presented. Future directions and economic aspects are discussed. Computed tomography (CT), magnetic resonance imaging (MRI) and FDG-PET for colorectal cancer and endorectal ultrasound for rectal cancer. Combined FDG-PET/CT. While other imaging modalities allow superior visualization of the extent and invasion depth of the primary tumor, PET/CT is most sensitive for the detection of distant metastases of colorectal cancer. We recommend a targeted use of PET/CT in cases of unclear M staging, prior to metastasectomy and in suspected cases of residual or recurrent colorectal carcinoma with equivocal conventional imaging. The role of PET/CT in radiotherapy planning and response monitoring needs to be determined. Currently there is no evidence to support the routine use of PET/CT for colorectal screening, staging or surveillance. To optimally exploit the synergy between morphologic and functional information, FDG-PET should generally be performed as an integrated FDG-PET/CT with a contrast-enhanced CT component in colorectal carcinoma. (orig.) [German] Die Fluordesoxyglukose-Positronenemissionstomographie/Computertomographie (FDG-PET/CT) hat in den letzten Jahren zunehmende Bedeutung zur Bildgebung des kolorektalen Karzinoms erlangt. In diesem Beitrag stellen wir den Stand der Literatur zur Rolle der PET/CT bei Screening, Staging, Bestrahlungsplanung, Beurteilung eines Therapieansprechens und Nachsorge des kolorektalen Karzinoms dar. Zudem wird auf gesundheitsoekonomische Aspekte und zukuenftige Entwicklungen eingegangen. CT, MRT, FDG-PET, beim Rektumkarzinom zusaetzlich endorektaler Ultraschall. Kombinierte FDG-PET/CT. Waehrend

  10. MRI and PET images fusion based on human retina model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The diagnostic potential of brain positron emission tomography (PET) imaging is limited by low spatial resolution.For solving this problem we propose a technique for the fusion of PET and MRI images. This fusion is a trade-off between the spectral information extracted from PET images and the spatial information extracted from high spatial resolution MRI. The proposed method can control this trade-off. To achieve this goal, it is necessary to build a multiscale fusion model, based on the retinal cell photoreceptors model. This paper introduces general prospects of this model, and its application in multispectral medical image fusion. Results showed that the proposed method preserves more spectral features with less spatial distortion.transform methods, the best spectral and spatial quality is only achieved simultaneously with the proposed feature-based data fusion method. This method does not require resampling images, which is an advantage over the other methods, and can perform in any aspect ratio between the pixels of MRI and PET images.

  11. A prototype of very high-resolution small animal PET scanner using silicon pad detectors

    CERN Document Server

    Park, S J; Huh, S; Kagan, H; Honscheid, K; Burdette, D; Chesi, Enrico Guido; Lacasta, C; Llosa, G; Mikuz, M; Studen, A; Weilhammer, P; Clinthorne, N H

    2007-01-01

    Abstract A very high-resolution small animal positron emission tomograph (PET), which can achieve sub-millimeter spatial resolution, is being developed using silicon pad detectors. The prototype PET for a single slice instrument consists of two 1 mm thick silicon pad detectors, each containing a 32×16 array of 1.4×1.4 mm pads readout with four VATAGP3 chips which have 128 channels low-noise self-triggering ASIC in each chip, coincidence units, a source turntable and tungsten slice collimator. The silicon detectors were located edgewise on opposite sides of a 4 cm field-of-view to maximize efficiency. Energy resolution is dominated by electronic noise, which is 0.98% (1.38 keV) FWHM at 140.5 keV. Coincidence timing resolution is 82.1 ns FWHM and coincidence efficiency was measured to be 1.04×10−3% from two silicon detectors with annihilation photons of 18F source. Image data were acquired and reconstructed using conventional 2-D filtered-back projection (FBP) and a maximum likelihood expectation maximizat...

  12. Performance of a DOI-encoding small animal PET system with monolithic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Carles, M., E-mail: montcar@ific.uv.es [Instituto de Instrumentacion para Imagen Molecular(I3M), Centro mixto CSIC-Universitat Politecnica de Valencia- IEMAT, Camino de Vera s/n, 46020 Valencia (Spain); Lerche, Ch.W. [Department X-Ray Imaging Systems, Philips Research Europe, Weisshausstrasse 2, D-52066 Aachen (Germany); Sanchez, F.; Orero, A.; Moliner, L.; Soriano, A.; Benlloch, J.M. [Instituto de Instrumentacion para Imagen Molecular(I3M), Centro mixto CSIC-Universitat Politecnica de Valencia- IEMAT, Camino de Vera s/n, 46020 Valencia (Spain)

    2012-12-11

    PET systems designed for specific applications require high resolution and sensitivity instrumentation. In dedicated system design smaller ring diameters and deeper crystals are widely used in order to increase the system sensitivity. However, this design increases the parallax error, which degrades the spatial image resolution gradually from the center to the edge of the field-of-view (FOV). Our group has designed a depth of interaction(DOI)-encoding small animal PET system based on monolithic crystals. In this work we investigate the restoration of radial resolution for transaxially off-center sources using the DOI information provided by our system. For this purpose we have designed a support for point like sources adapted to our system geometry that allows a spatial compression and resolution response study. For different point source radial positions along vertical and horizontal axes of a FOV transaxial plane we compare the results obtained by three methods: without DOI information, with the DOI provided by our system and with the assumption that all the {gamma}-rays interact at half depth of the crystal thickness. Results show an improvement of the mean resolution of 10% with the half thickness assumption and a 16% achieved using the DOI provided by the system. Furthermore, a 10% restoration of the resolution uniformity is obtained using the half depth assumption and an 18% restoration using measured DOI.

  13. Evaluation of transmission methodology and attenuation correction for the microPET Focus 220 animal scanner

    Energy Technology Data Exchange (ETDEWEB)

    Lehnert, Wencke [School of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe NSW 1825 (Australia); Meikle, Steven R [School of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe NSW 1825 (Australia); Siegel, Stefan [Siemens Preclinical Solutions, 810 Innovation Drive, Knoxville, TN 37932 (United States); Newport, Danny [Siemens Preclinical Solutions, 810 Innovation Drive, Knoxville, TN 37932 (United States); Banati, Richard B [School of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe NSW 1825 (Australia); Rosenfeld, Anatoly B [Centre for Medical Radiation Physics, University of Wollongong, Wollongong NSW 2522 (Australia)

    2006-08-21

    An accurate, low noise estimate of photon attenuation in the subject is required for quantitative microPET studies of molecular tracer distributions in vivo. In this work, several transmission-based measurement techniques were compared, including coincidence mode with and without rod windowing, singles mode with two different energy sources ({sup 68}Ge and {sup 57}Co), and postinjection transmission scanning. In addition, the effectiveness of transmission segmentation and the propagation of transmission bias and noise into the emission images were examined. The {sup 57}Co singles measurements provided the most accurate attenuation coefficients and superior signal-to-noise ratio, while {sup 68}Ge singles measurements were degraded due to scattering from the object. Scatter correction of {sup 68}Ge transmission data improved the accuracy for a 10 cm phantom but over-corrected for a mouse phantom. {sup 57}Co scanning also resulted in low bias and noise in postinjection transmission scans for emission activities up to 20 MBq. Segmentation worked most reliably for transmission data acquired with {sup 57}Co but the minor improvement in accuracy of attenuation coefficients and signal-to-noise may not justify its use, particularly for small subjects. We conclude that {sup 57}Co singles transmission scanning is the most suitable method for measured attenuation correction on the microPET Focus 220 animal scanner.

  14. Gallium-68 EDTA PET/CT for Renal Imaging.

    Science.gov (United States)

    Hofman, Michael S; Hicks, Rodney J

    2016-09-01

    Nuclear medicine renal imaging provides important functional data to assist in the diagnosis and management of patients with a variety of renal disorders. Physiologically stable metal chelates like ethylenediaminetetraacetic acid (EDTA) and diethylenetriamine penta-acetate (DTPA) are excreted by glomerular filtration and have been radiolabelled with a variety of isotopes for imaging glomerular filtration and quantitative assessment of glomerular filtration rate. Gallium-68 ((68)Ga) EDTA PET usage predates Technetium-99m ((99m)Tc) renal imaging, but virtually disappeared with the widespread adoption of gamma camera technology that was not optimal for imaging positron decay. There is now a reemergence of interest in (68)Ga owing to the greater availability of PET technology and use of (68)Ga to label other radiotracers. (68)Ga EDTA can be used a substitute for (99m)Tc DTPA for wide variety of clinical indications. A key advantage of PET for renal imaging over conventional scintigraphy is 3-dimensional dynamic imaging, which is particularly helpful in patients with complex anatomy in whom planar imaging may be nondiagnostic or difficult to interpret owing to overlying structures containing radioactive urine that cannot be differentiated. Other advantages include accurate and absolute (rather than relative) camera-based quantification, superior spatial and temporal resolution and integrated multislice CT providing anatomical correlation. Furthermore, the (68)Ga generator enables on-demand production at low cost, with no additional patient radiation exposure compared with conventional scintigraphy. Over the past decade, we have employed (68)Ga EDTA PET/CT primarily to answer difficult clinical questions in patients in whom other modalities have failed, particularly when it was envisaged that dynamic 3D imaging would be of assistance. We have also used it as a substitute for (99m)Tc DTPA if unavailable owing to supply issues, and have additionally examined the role of

  15. Use of segmented CT transmission map to avoid metal artifacts in PET images by a PET-CT device

    International Nuclear Information System (INIS)

    Background: Attenuation correction is generally used to PET images to achieve count rate values independent from tissue densities. The goal of this study was to provide a qualitative comparison of attenuation corrected PET images produced by a PET-CT device (CT, 120 kV, 40 mAs, FOV 600 mm) with and without segmentation of transmission data (ACseg+ and ACseg-respectively). Methods: The reconstructed images were compared to attenuation corrected images obtained with a high-energy transmission source (Cs-137 – 662 keV). Thirty oncologic patients were studied using CT and 137Cs for attenuation correction. All image data were acquired using the Gemini PET-CT scanner (Philips Medical Systems). It is an open PET-CT system that consists of the MX8000 multislice CT and the Allegro PET scanner arranged in a separable configuration. Images with ACseg+ and ACseg- were analyzed simultaneously in coronal, sagittal and transaxial planes. Two nuclear medicine physicians reviewed the image sets. Results: The image quality in the area of metal implants was better with ACseg+ than ACseg-, without metal induced artifacts generally observed in CT corrected images. Further the images with ACseg+ were qualitatively comparable to those obtained with 137Cs attenuation correction. Conclusions: In case of metal implants, PET studies corrected by CT should preferably use the ACseg+ method to avoid the image artifacts

  16. Feasibility of breathing-adapted PET/CT imaging for radiation therapy of Hodgkin lymphoma

    DEFF Research Database (Denmark)

    Aznar, M C; Andersen, Flemming; Berthelsen, A K;

    2011-01-01

    Aim: Respiration can induce artifacts in positron emission tomography (PET)/computed tomography (CT) images leading to uncertainties in tumour volume, location and uptake quantification. Respiratory gating for PET images is now established but is not directly translatable to a radiotherapy setup....... in PET/CT images. These results suggest that advanced therapies (such as SUV-based dose painting) will likely require breathing-adapted PET images and that the relevant SUV thresholds are yet to be investigated....

  17. Feasibility of breathing-adapted PET/CT imaging for radiation therapy of Hodgkin lymphoma

    DEFF Research Database (Denmark)

    Aznar, M C; Andersen, Flemming; Berthelsen, A K;

    2011-01-01

    Aim: Respiration can induce artifacts in positron emission tomography (PET)/computed tomography (CT) images leading to uncertainties in tumour volume, location and uptake quantification. Respiratory gating for PET images is now established but is not directly translatable to a radiotherapy setup....... uptake in PET/CT images. These results suggest that advanced therapies (such as SUV-based dose painting) will likely require breathing-adapted PET images and that the relevant SUV thresholds are yet to be investigated....

  18. MRI and PET image fusion using fuzzy logic and image local features.

    Science.gov (United States)

    Javed, Umer; Riaz, Muhammad Mohsin; Ghafoor, Abdul; Ali, Syed Sohaib; Cheema, Tanveer Ahmed

    2014-01-01

    An image fusion technique for magnetic resonance imaging (MRI) and positron emission tomography (PET) using local features and fuzzy logic is presented. The aim of proposed technique is to maximally combine useful information present in MRI and PET images. Image local features are extracted and combined with fuzzy logic to compute weights for each pixel. Simulation results show that the proposed scheme produces significantly better results compared to state-of-art schemes.

  19. Application of inulin-type fructans in animal feed and pet food

    NARCIS (Netherlands)

    Verdonk, J.M.A.J.; Shim, S.B.; Leeuwen, van P.; Verstegen, M.W.A.

    2005-01-01

    The inulin-type fructans are non-digestible oligosaccharides that are fermented in the gastrointestinal tract of farm animals and pets. This review focuses on the various effects of inulin-type fructans in pigs, poultry, calves and companion animals. Effects of the inulin-type fructans on gut microf

  20. Spatio-temporal diffusion of dynamic PET images

    Energy Technology Data Exchange (ETDEWEB)

    Tauber, C; Chalon, S; Guilloteau, D [Inserm U930, CNRS ERL3106, Universite Francois Rabelais, Tours (France); Stute, S; Buvat, I [IMNC, IN2P3, UMR 8165 CNRS-Paris 7 and Paris 11 Universities, Orsay (France); Chau, M [ASA-Advanced Solutions Accelerator, Montpellier (France); Spiteri, P, E-mail: clovis.tauber@univ-tours.fr [IRIT-ENSEEIHT, UMR CNRS 5505, Toulouse (France)

    2011-10-21

    Positron emission tomography (PET) images are corrupted by noise. This is especially true in dynamic PET imaging where short frames are required to capture the peak of activity concentration after the radiotracer injection. High noise results in a possible bias in quantification, as the compartmental models used to estimate the kinetic parameters are sensitive to noise. This paper describes a new post-reconstruction filter to increase the signal-to-noise ratio in dynamic PET imaging. It consists in a spatio-temporal robust diffusion of the 4D image based on the time activity curve (TAC) in each voxel. It reduces the noise in homogeneous areas while preserving the distinct kinetics in regions of interest corresponding to different underlying physiological processes. Neither anatomical priors nor the kinetic model are required. We propose an automatic selection of the scale parameter involved in the diffusion process based on a robust statistical analysis of the distances between TACs. The method is evaluated using Monte Carlo simulations of brain activity distributions. We demonstrate the usefulness of the method and its superior performance over two other post-reconstruction spatial and temporal filters. Our simulations suggest that the proposed method can be used to significantly increase the signal-to-noise ratio in dynamic PET imaging.

  1. Image artifacts from MR-based attenuation correction in clinical, whole-body PET/MRI

    DEFF Research Database (Denmark)

    Keller, Sune H; Holm, Søren; Hansen, Adam E;

    2013-01-01

    Integrated whole-body PET/MRI tomographs have become available. PET/MR imaging has the potential to supplement, or even replace combined PET/CT imaging in selected clinical indications. However, this is true only if methodological pitfalls and image artifacts arising from novel MR-based attenuation...

  2. Neuroprotective effect of the traditional Chinese herbal formulaTongxinluo:a PET imaging study in rats

    Institute of Scientific and Technical Information of China (English)

    Xiao Cheng; Haoxuan Luo; Lihua Zhou; Lixin Wang; Jingbo Sun; Yan Huang; Enli Luo; Yefeng Cai

    2014-01-01

    Tongxinluo has been widely used in China for the treatment of acute stroke and for neu-roprotection. However, there are few positron emission tomography (PET) studies on the neuroprotective effect ofTongxinluo on cerebral ischemia/reperfusion in small animals. In the present study,Tongxinluosuperfine powder suspension or its vehicle was administered intragastrically to rats for 5 successive days before middle cerebral artery occlusion.18F-lfuo-rodeoxyglucose (FDG) small animal PET imaging showed that at 1 and 2 weeks after cerebral ischemia/reperfusion, glucose metabolism in the ischemic area was greater in rats that had receivedTongxinluo than in those that had received the vehicle. Nissl staining showed that 2 weeks after cerebral ischemia/reperfusion, there was less neuronal loss in the prefrontal cortex in Tongxinluo-treated rats than in controls. In addition,Tongxinluo-treated animals showed better neurologic function and lower cerebral infarct volume than rats that received the vehicle. These findings suggest thatTongxinluo exhibits neuroprotective effects in cerebral ischemia/reper-fusion injury and demonstrates that18F-FDG small animal PET imaging is a useful tool with which to study the molecular pharmacology of traditional Chinese medicine.

  3. Preclinical imaging in animal models of radiation therapy

    International Nuclear Information System (INIS)

    Modern radiotherapy benefits from precise and targeted diagnostic and pretherapeutic imaging. Standard imaging modalities, such as computed tomography (CT) offer high morphological detail but only limited functional information on tumors. Novel functional and molecular imaging modalities provide biological information about tumors in addition to detailed morphological information. Perfusion magnetic resonance imaging (MRI) CT or ultrasound-based perfusion imaging as well as hybrid modalities, such as positron emission tomography (PET) CT or MRI-PET have the potential to identify and precisely delineate viable and/or perfused tumor areas, enabling optimization of targeted radiotherapy. Functional information on tissue microcirculation and/or glucose metabolism allow a more precise definition and treatment of tumors while reducing the radiation dose and sparing the surrounding healthy tissue. In the development of new imaging methods for planning individualized radiotherapy, preclinical imaging and research plays a pivotal role, as the value of multimodality imaging can only be assessed, tested and adequately developed in a preclinical setting, i.e. in animal tumor models. New functional imaging modalities will play an increasing role for the surveillance of early treatment response during radiation therapy and in the assessment of the potential value of new combination therapies (e.g. combining anti-angiogenic drugs with radiotherapy). (orig.)

  4. An integrated multimodality image-guided robot system for small-animal imaging research

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Wen-Lin [Department of Radiology, Tzu-Chi University and Radiation Oncology, Buddhist Tzu-Chi General Hospital Hualien, Taiwan (China); Hsin Wu, Tung [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan (China); Hsu, Shih-Ming [Department of Biomedical Imaging and Radiological Sciences, China Medical University, Taichung, Taiwan (China); Chen, Chia-Lin [Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan (China); Lee, Jason J.S., E-mail: jslee@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan (China); Huang, Yung-Hui, E-mail: yhhuang@isu.edu.tw [Department of Medical Imaging and Radiological Sciences, I-Shou University, Kaohsiung, Taiwan (China)

    2011-10-01

    We design and construct an image-guided robot system for use in small-animal imaging research. This device allows the use of co-registered small-animal PET-MRI images to guide the movements of robotic controllers, which will accurately place a needle probe at any predetermined location inside, for example, a mouse tumor, for biological readouts without sacrificing the animal. This system is composed of three major components: an automated robot device, a CCD monitoring mechanism, and a multimodality registration implementation. Specifically, the CCD monitoring mechanism was used for correction and validation of the robot device. To demonstrate the value of the proposed system, we performed a tumor hypoxia study that involved FMISO small-animal PET imaging and the delivering of a pO{sub 2} probe into the mouse tumor using the image-guided robot system. During our evaluation, the needle positioning error was found to be within 0.153{+-}0.042 mm of desired placement; the phantom simulation errors were within 0.693{+-}0.128 mm. In small-animal studies, the pO{sub 2} probe measurements in the corresponding hypoxia areas showed good correlation with significant, low tissue oxygen tensions (less than 6 mmHg). We have confirmed the feasibility of the system and successfully applied it to small-animal investigations. The system could be easily adapted to extend to other biomedical investigations in the future.

  5. Simultaneous PET/MRI with 13C magnetic resonance spectroscopic imaging (hyperPET): phantom-based evaluation of PET quantification

    DEFF Research Database (Denmark)

    Hansen, Adam E.; Andersen, Flemming L.; Henriksen, Sarah T.;

    2016-01-01

    -MRSI phantoms including a NEMA [18F]-FDG phantom, 13C-acetate and 13C-urea sources, and hyperpolarized 13C-pyruvate were imaged repeatedly with PET and/or 13C-MRSI. Measurements evaluated for interference effects included PET activity values in the largest sphere and a background region; total number of PET......Background: Integrated PET/MRI with hyperpolarized 13C magnetic resonance spectroscopic imaging (13C-MRSI) offers simultaneous, dual-modality metabolic imaging. A prerequisite for the use of simultaneous imaging is the absence of interference between the two modalities. This has been documented...... for a clinical whole-body system using simultaneous 1 H-MRI and PET but never for 13C-MRSI and PET. Here, the feasibility of simultaneous PET and 13C-MRSI as well as hyperpolarized 13C-MRSI in an integrated whole-body PET/MRI hybrid scanner is evaluated using phantom experiments. Methods: Combined PET and 13C...

  6. ClearPEM: prototype PET device dedicated to breast imaging

    CERN Multimedia

    Joao Varela

    2009-01-01

    Clinical trials have begun in Portugal on a new breast imaging system (ClearPEM) using positron emission tomography (PET). The system, developed by a Portuguese consortium in collaboration with CERN and laboratories participating in the Crystal Clear collaboration, will detect even the smallest tumours and thus help avoid unnecessary biopsies.

  7. (18)F- and (68)Ga-Labeled Neurotensin Peptides for PET Imaging of Neurotensin Receptor 1.

    Science.gov (United States)

    Maschauer, Simone; Einsiedel, Jürgen; Hübner, Harald; Gmeiner, Peter; Prante, Olaf

    2016-07-14

    The neurotensin (NT) receptor-1 (NTS1) is overexpressed in a variety of carcinomas and is therefore an interesting target for imaging with positron emission tomography (PET). The aim of this study was the development of new NT derivatives based on the metabolically stable peptide sequence NLys-Lys-Pro-Tyr-Tle-Leu suitable for PET imaging. The NT peptides were synthesized by solid-phase supported peptide synthesis and elongated with respective chelators (NODA-GA, DOTA) for (68)Ga-labeling or propargylglycine for (18)F-labeling via copper-catalyzed azide-alkyne cycloaddition. Receptor affinities of the peptides for NTS1 were in the range of 19-110 nM. Biodistribution studies using HT29 tumor-bearing mice showed highest tumor uptake for [(68)Ga]6 and [(68)Ga]8 and specific binding in small-animal PET studies. The tumor uptake of (68)Ga-labeled peptides in vivo significantly correlated with the in vitro Ki values for NTS1. [(68)Ga]8 displayed an excellent tumor-to-background ratio and could therefore be considered as an appropriate molecular probe for NTS1 imaging by PET. PMID:27336295

  8. Optimization and characterization of PET scanners for Medical Imaging

    OpenAIRE

    Cucciati,

    2014-01-01

    Positron emission tomography is an imaging technique that appeared to be a valid instrument for cancers detection and neuro-imaging studies. Since first models built during 1960s, an incredible effort has been done by researchers to develop scanners more and more advanced with higher specificity and efficiency. Monte Carlo simulations have shown to be a very important tool during design phase of PET prototypes thanks to their ability to simulate systems with many coupled degrees of freedom, a...

  9. Ready for prime time? Dual tracer PET and SPECT imaging

    OpenAIRE

    Fakhri, Georges El

    2012-01-01

    Dual isotope single photon emission computed tomography (SPECT) and dual tracer positron emission tomography (PET) imaging have great potential in clinical and molecular applications in the pediatric as well as the adult populations in many areas of brain, cardiac, and oncologic imaging as it allows the exploration of different physiological and molecular functions (e.g., perfusion, neurotransmission, metabolism, apoptosis, angiogenesis) under the same physiological and physical conditions. T...

  10. A dedicated high resolution PET imager for plant sciences

    CERN Document Server

    Wang, Qiang; Li, Ke; Wen, Jie; Komarov, Sergey; O'Sullivan, Joseph A; Tai, Yuan-Chuan

    2014-01-01

    PET provides in vivo molecular and functional imaging capability that is crucial to studying the interaction of plant with changing environment at the whole-plant level. We have developed a dedicated plant PET imager that features high spatial resolution, housed in a fully controlled environment provided by a plant growth chamber (PGC). The system currently contains two types of detector modules: 84 microPET R4 block detectors with 2.2 mm crystals to provide a large detecting area; and 32 Inveon block detectors with 1.5 mm crystals to provide higher spatial resolution. Outputs of the four microPET block detectors in a modular housing are concatenated by a custom printed circuit board to match the output characteristics of an Inveon detector. All the detectors are read out by QuickSilver electronics. The detector modules are configured to full rings with a 15 cm diameter trans-axial field of view (FOV) for dynamic tomographic imaging of small plants. Potentially, the Inveon detectors can be reconfigured to qua...

  11. Guidelines for 18F-FDG PET and PET-CT imaging in paediatric oncology

    DEFF Research Database (Denmark)

    Stauss, J.; Franzius, C.; Pfluger, T.;

    2008-01-01

    by the EANM Paediatric Committee, do not intend to compete with the existing guidelines, but rather aim at providing additional information on issues particularly relevant to PET imaging of children with cancer. CONCLUSION: The guidelines summarize the views of the Paediatric Committee of the European...... not be deemed inclusive of all proper procedures or exclusive of other procedures reasonably directed to obtaining the same results Udgivelsesdato: 2008/8...

  12. Predicting standard-dose PET image from low-dose PET and multimodal MR images using mapping-based sparse representation

    Science.gov (United States)

    Wang, Yan; Zhang, Pei; An, Le; Ma, Guangkai; Kang, Jiayin; Shi, Feng; Wu, Xi; Zhou, Jiliu; Lalush, David S.; Lin, Weili; Shen, Dinggang

    2016-01-01

    Positron emission tomography (PET) has been widely used in clinical diagnosis for diseases and disorders. To obtain high-quality PET images requires a standard-dose radionuclide (tracer) injection into the human body, which inevitably increases risk of radiation exposure. One possible solution to this problem is to predict the standard-dose PET image from its low-dose counterpart and its corresponding multimodal magnetic resonance (MR) images. Inspired by the success of patch-based sparse representation (SR) in super-resolution image reconstruction, we propose a mapping-based SR (m-SR) framework for standard-dose PET image prediction. Compared with the conventional patch-based SR, our method uses a mapping strategy to ensure that the sparse coefficients, estimated from the multimodal MR images and low-dose PET image, can be applied directly to the prediction of standard-dose PET image. As the mapping between multimodal MR images (or low-dose PET image) and standard-dose PET images can be particularly complex, one step of mapping is often insufficient. To this end, an incremental refinement framework is therefore proposed. Specifically, the predicted standard-dose PET image is further mapped to the target standard-dose PET image, and then the SR is performed again to predict a new standard-dose PET image. This procedure can be repeated for prediction refinement of the iterations. Also, a patch selection based dictionary construction method is further used to speed up the prediction process. The proposed method is validated on a human brain dataset. The experimental results show that our method can outperform benchmark methods in both qualitative and quantitative measures.

  13. Designing Image Operators for MRI-PET Image Fusion of the Brain

    Science.gov (United States)

    Márquez, Jorge; Gastélum, Alfonso; Padilla, Miguel A.

    2006-09-01

    Our goal is to obtain images combining in a useful and precise way the information from 3D volumes of medical imaging sets. We address two modalities combining anatomy (Magnetic Resonance Imaging or MRI) and functional information (Positron Emission Tomography or PET). Commercial imaging software offers image fusion tools based on fixed blending or color-channel combination of two modalities, and color Look-Up Tables (LUTs), without considering the anatomical and functional character of the image features. We used a sensible approach for image fusion taking advantage mainly from the HSL (Hue, Saturation and Luminosity) color space, in order to enhance the fusion results. We further tested operators for gradient and contour extraction to enhance anatomical details, plus other spatial-domain filters for functional features corresponding to wide point-spread-function responses in PET images. A set of image-fusion operators was formulated and tested on PET and MRI acquisitions.

  14. Pitfalls and Limitations of PET/CT in Brain Imaging.

    Science.gov (United States)

    Salmon, Eric; Bernard Ir, Claire; Hustinx, Roland

    2015-11-01

    Neurologic applications were at the forefront of PET imaging when the technique was developed in the mid-1970s. Although oncologic indications have become prominent in terms of number of studies performed worldwide, neurology remains a major field in which functional imaging provides unique information, both for clinical and research purposes. The evaluation of glucose metabolism using FDG remains the most frequent exploration, but in recent years, alternative radiotracers have been developed, including fluorinated amino acid analogues for primary brain tumor imaging and fluorinated compounds for assessing the amyloid deposits in patients with suspected Alzheimer disease. As the brain is enclosed in the skull, which presents fixed landmarks, it is relatively easy to coregister images obtained with various cross-sectional imaging methods, either functional or anatomical, with a relatively high accuracy and robustness. Nevertheless, PET in neurology has fully benefited from the advent of hybrid imaging. Attenuation and scatter correction is now much faster and equally accurate, using CT as compared with the traditional transmission scan using an external radioactive source. The perfect coregistration with the CT data, which is now systematically performed, also provides its own set of valuable information, for instance regarding cerebral atrophy. However, hybrid imaging in neurology comes with pitfalls and limitations, in addition to those that are well known, for example, blood glucose levels or psychotropic drugs that greatly affect the physiological FDG uptake. Movements of the patient's head, either during the PET acquisition or between the PET and the CT acquisitions will generate artifacts that may be very subtle yet lead to erroneous interpretation of the study. Similarly, quantitative analysis, such as voxel-based analyses, may prove very helpful in improving the diagnostic accuracy and the reproducibility of the reading, but a wide variety of artifacts may

  15. Simultaneous PET/MR imaging in a human brain PET/MR system in 50 patients-Current state of image quality

    Energy Technology Data Exchange (ETDEWEB)

    Schwenzer, N.F., E-mail: nina.schwenzer@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Stegger, L., E-mail: stegger@gmx.net [Department of Nuclear Medicine and European Institute for Molecular Imaging, University of Muenster, Muenster (Germany); Bisdas, S., E-mail: sbisdas@gmail.com [Department of Diagnostic and Interventional Neuroradiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Schraml, C., E-mail: christina.schraml@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Kolb, A., E-mail: armin.kolb@med.uni-tuebingen.de [Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Preclinical Imaging and Radiopharmacy, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Boss, A., E-mail: Andreas.Boss@usz.ch [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Institute of Diagnostic and Interventional Radiology, University Hospital Zuerich, Zuerich (Switzerland); Mueller, M., E-mail: mark.mueller@med.uni-tuebingen.de [Department of Nuclear Medicine, Eberhard-Karls University Tuebingen, Tuebingen (Germany); and others

    2012-11-15

    Objectives: The present work illustrates the current state of image quality and diagnostic accuracy in a new hybrid BrainPET/MR. Materials and methods: 50 patients with intracranial masses, head and upper neck tumors or neurodegenerative diseases were examined with a hybrid BrainPET/MR consisting of a conventional 3T MR system and an MR-compatible PET insert. Directly before PET/MR, all patients underwent a PET/CT examination with either [{sup 18}F]-FDG, [{sup 11}C]-methionine or [{sup 68}Ga]-DOTATOC. In addition to anatomical MR scans, functional sequences were performed including diffusion tensor imaging (DTI), arterial spin labeling (ASL) and proton-spectroscopy. Image quality score of MR imaging was evaluated using a 4-point-scale. PET data quality was assessed by evaluating FDG-uptake and tumor delineation with [{sup 11}C]-methionine and [{sup 68}Ga]-DOTATOC. FDG uptake quantification accuracy was evaluated by means of ROI analysis (right and left frontal and temporo-occipital lobes). The asymmetry indices and ratios between frontal and occipital ROIs were compared. Results: In 45/50 patients, PET/MR examination was successful. Visual analysis revealed a diagnostic image quality of anatomical MR imaging (mean quality score T2 FSE: 1.27 {+-} 0.54; FLAIR: 1.38 {+-} 0.61). ASL and proton-spectroscopy was possible in all cases. In DTI, dental artifacts lead to one non-diagnostic dataset (mean quality score DTI: 1.32 {+-} 0.69; ASL: 1.10 {+-} 0.31). PET datasets of PET/MR and PET/CT offered comparable tumor delineation with [{sup 11}C]-methionine; additional lesions were found in 2/8 [{sup 68}Ga]-DOTATOC-PET in the PET/MR. Mean asymmetry index revealed a high accordance between PET/MR and PET/CT (1.5 {+-} 2.2% vs. 0.9 {+-} 3.6%; mean ratio (frontal/parieto-occipital) 0.93 {+-} 0.08 vs. 0.96 {+-} 0.05), respectively. Conclusions: The hybrid BrainPET/MR allows for molecular, anatomical and functional imaging with uncompromised MR image quality and a high accordance

  16. PET molecular imaging in stem cell therapy for neurological diseases

    International Nuclear Information System (INIS)

    Human neurological diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, spinal cord injury and multiple sclerosis are caused by loss of different types of neurons and glial cells in the brain and spinal cord. At present, there are no effective therapies against these disorders. Discovery of the therapeutic potential of stem cells offers new strategies for the treatment of neurological diseases. Direct assessment of stem cells' survival, interaction with the host and impact on neuronal functions after transplantation requires advanced in vivo imaging techniques. Positron emission tomography (PET) is a potential molecular imaging modality to evaluate the viability and function of transplanted tissue or stem cells in the nervous system. This review focuses on PET molecular imaging in stem cell therapy for neurological diseases. (orig.)

  17. PET molecular imaging in stem cell therapy for neurological diseases

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiachuan; Zhang, Hong [Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Zhejiang University, Medical PET Center, Hangzhou (China); Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou (China); Tian, Mei [University of Texas, M.D. Anderson Cancer Center, Department of Experimental Diagnostic Imaging, Houston, TX (United States)

    2011-10-15

    Human neurological diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, spinal cord injury and multiple sclerosis are caused by loss of different types of neurons and glial cells in the brain and spinal cord. At present, there are no effective therapies against these disorders. Discovery of the therapeutic potential of stem cells offers new strategies for the treatment of neurological diseases. Direct assessment of stem cells' survival, interaction with the host and impact on neuronal functions after transplantation requires advanced in vivo imaging techniques. Positron emission tomography (PET) is a potential molecular imaging modality to evaluate the viability and function of transplanted tissue or stem cells in the nervous system. This review focuses on PET molecular imaging in stem cell therapy for neurological diseases. (orig.)

  18. PET imaging biomarkers in head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Differding, Sarah; Gregoire, Vincent [Universite Catholique de Louvain, St-Luc University Hospital, Department of Radiation Oncology, and Center for Molecular Imaging, Radiotherapy and Oncology (MIRO), Institut de Recherche Experimentale et Clinique (IREC), Brussels (Belgium); Hanin, Francois-Xavier [Universite Catholique de Louvain, St-Luc University Hospital, Department of Nuclear Medicine, and Center for Molecular Imaging, Radiotherapy and Oncology (MIRO), Institut de Recherche Experimentale et Clinique (IREC), Brussels (Belgium)

    2015-04-01

    In locally advanced head and neck squamous cell carcinoma (HNSCC), the role of imaging becomes more and more critical in the management process. In this framework, molecular imaging techniques such as PET allow noninvasive assessment of a range of tumour biomarkers such as metabolism, hypoxia and proliferation, which can serve different purposes. First, in a pretreatment setting they can influence therapy selection strategies and target delineation for radiation therapy. Second, their predictive and/or prognostic value could help enhance the therapeutic ratio in the management of HNSCC. Third, treatment modification can be performed through the generation of a molecular-based heterogeneous dose distribution with dose escalation to the most resistant parts of the tumour, a concept known as dose painting. Fourth, they are increasingly becoming a tool for monitoring response to therapy. In this review, PET imaging biomarkers used in the routine management of HNSCC or under investigation are discussed. (orig.)

  19. PET Imaging of the AT{sub 1} receptor with [{sup 11}C]KR31173

    Energy Technology Data Exchange (ETDEWEB)

    Zober, Tamas G. [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-0817 (United States); Mathews, William B. [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-0817 (United States); Seckin, Esen [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-0817 (United States); Yoo, Sung-eun [Center for Biological Modulators, Korea Research Institute of Chemical Technology, Daejeon 305-343 (Korea, Republic of); Hilton, John [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-0817 (United States); Xia Jinsong [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-0817 (United States); Sandberg, Kathryn [Department of Medicine, Georgetown University, Washington, DC 20057 (United States); Ravert, Hayden T. [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-0817 (United States); Dannals, Robert F. [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-0817 (United States); Szabo, Zsolt [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-0817 (United States)]. E-mail: zszabo@jhmi.edu

    2006-01-15

    Aim: The goal of this study was to investigate the binding characteristics of [{sup 11}C]KR31173 and its applicability for PET studies of the AT{sub 1} receptor (AT{sub 1}R). Methods: Ex vivo biodistribution and pharmacology were tested in mice. PET imaging was performed in mice, beagle dogs and a baboon. To assess nonspecific binding, PET imaging was performed both before and after pretreatment with a potent AT{sub 1}R antagonist. In the baboon, PET imaging was also performed with the previously developed radioligand [{sup 11}C]L-159,884 for comparison. Results: Ex vivo biodistribution studies in mice showed specific binding rates of 80-90% in the adrenals, kidneys, lungs and heart. Specific binding was confirmed in mice using small animal PET. In dogs, renal cortex tissue concentration at 75-95 min postinjection (pi) was 63 nCi/ml per millicurie at a specific binding rate of 95%. In the baboon renal cortex, tissue activity at 55-75 min pi was 345 nCi/ml per millicurie. In the baboon the specific binding of [{sup 11}C]KR31173 was higher (81%) than the specific binding of [{sup 11}C]L-159,884 (34%). Conclusion: [{sup 11}C]KR31173 shows accumulation and significant specific binding to the AT{sub 1}R in the kidneys of mice, dogs and baboon. These findings suggest that this radioligand is suited for imaging the renal cortical AT{sub 1}R in multiple species.

  20. Preclinical Study on GRPR-Targeted (68)Ga-Probes for PET Imaging of Prostate Cancer.

    Science.gov (United States)

    Sun, Yao; Ma, Xiaowei; Zhang, Zhe; Sun, Ziyan; Loft, Mathias; Ding, Bingbing; Liu, Changhao; Xu, Liying; Yang, Meng; Jiang, Yuxin; Liu, Jianfeng; Xiao, Yuling; Cheng, Zhen; Hong, Xuechuan

    2016-08-17

    Gastrin-releasing peptide receptor (GRPR) targeted positron emission tomography (PET) is a highly promising approach for imaging of prostate cancer (PCa) in small animal models and patients. Developing a GRPR-targeted PET probe with excellent in vivo performance such as high tumor uptake, high contrast, and optimal pharmacokinetics is still very challenging. Herein, a novel bombesin (BBN) analogue (named SCH1) based on JMV594 peptide modified with an 8-amino octanoic acid spacer (AOC) was thus designed and conjugated with the metal chelator 1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid (NODAGA). The resulting NODAGA-SCH1 was then radiolabeled with (68)Ga and evaluated for PET imaging of PCa. Compared with (68)Ga-NODAGA-JMV594 probe, (68)Ga-NODAGA-SCH1 exhibited excellent PET/CT imaging properties on PC-3 tumor-bearing nude mice, such as high tumor uptake (5.80 ± 0.42 vs 3.78 ± 0.28%ID/g, 2 h) and high tumor/muscle contrast (16.6 ± 1.50 vs 8.42 ± 0.61%ID/g, 2 h). Importantly, biodistribution data indicated a relatively similar accumulation of (68)Ga-NODAGA-SCH1 was observed in the liver (4.21 ± 0.42%ID/g) and kidney (3.41 ± 0.46%ID/g) suggesting that the clearance is through both the kidney and the liver. Overall, (68)Ga-NODAGA-SCH1 showed promising in vivo properties and is a promising candidate for translation into clinical PET-imaging of PCa patients. PMID:27399868

  1. Small Animal Radionuclide Imaging With Focusing Gamma-Ray Optics

    Energy Technology Data Exchange (ETDEWEB)

    Hill, R; Decker, T; Epstein, M; Ziock, K; Pivovaroff, M J; Craig, W W; Jernigan, J G; Barber, W B; Christensen, F E; Funk, T; Hailey, C J; Hasegawa, B H; Taylor, C

    2004-02-27

    Significant effort currently is being devoted to the development of noninvasive imaging systems that allow in vivo assessment of biological and biomolecular interactions in mice and other small animals. While physiological function in small animals can be localized and imaged using conventional radionuclide imaging techniques such as single-photon emission tomography (SPECT) and positron emission tomography (PET), these techniques inherently are limited to spatial resolutions of 1-2 mm. For this reason, we are developing a small animal radionuclide imaging system (SARIS) using grazing incidence optics to focus gamma-rays emitted by {sup 125}I and other radiopharmaceuticals. We have developed a prototype optic with sufficient accuracy and precision to focus the 27.5 keV photons from {sup 125}I onto a high-resolution imaging detector. Experimental measurements from the prototype have demonstrated that the optic can focus X-rays from a microfocus X-ray tube to a spot having physical dimensions (approximately 1500 microns half-power diameter) consistent with those predicted by theory. Our theoretical and numerical analysis also indicate that an optic can be designed and build that ultimately can achieve 100 {micro}m spatial resolution with sufficient efficiency to perform in vivo single photon emission imaging studies in small animal.

  2. A micro-PET/CT approach using O-(2-[{sup 18}F]fluoroethyl)-L-tyrosine in an experimental animal model of F98 glioma for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Menichetti, L., E-mail: luca.menichetti@ifc.cnr.it [CNR Institute of Clinical Physiology, Pisa (Italy); Petroni, D.; Panetta, D. [CNR Institute of Clinical Physiology, Pisa (Italy); Burchielli, S. [Fondazione CNR/Regione Toscana G. Monasterio, Pisa (Italy); Bortolussi, Silva [Dept. Theoretical and Nuclear Physics, University of Pavia, Pavia (Italy); Matteucci, M. [Scuola Superiore Sant' Anna, Pisa (Italy); Pascali, G.; Del Turco, S. [CNR Institute of Clinical Physiology, Pisa (Italy); Del Guerra, A. [Department of Physics, University of Pisa, Pisa (Italy); Altieri, S. [Dept. Theoretical and Nuclear Physics, University of Pavia, Pavia (Italy); Salvadori, P.A. [CNR Institute of Clinical Physiology, Pisa (Italy)

    2011-12-15

    The present study focuses on a micro-PET/CT application to be used for experimental Boron Neutron Capture Therapy (BNCT), which integrates, in the same frame, micro-CT derived anatomy and PET radiotracer distribution. Preliminary results have demonstrated that {sup 18}F-fluoroethyl-tyrosine (FET)/PET allows the identification of the extent of cerebral lesions in F98 tumor bearing rat. Neutron autoradiography and {alpha}-spectrometry on axial tissues slices confirmed the tumor localization and extraction, after the administration of fructose-boronophenylalanine (BPA). Therefore, FET-PET approach can be used to assess the transport, the net influx, and the accumulation of FET, as an aromatic amino acid analog of BPA, in experimental animal model. Coregistered micro-CT images allowed the accurate morphological localization of the radiotracer distribution and its potential use for experimental BNCT.

  3. High-resolution image reconstruction for PET using estimated detector response functions

    Science.gov (United States)

    Tohme, Michel S.; Qi, Jinyi

    2007-02-01

    The accuracy of the system model in an iterative reconstruction algorithm greatly affects the quality of reconstructed PET images. For efficient computation in reconstruction, the system model in PET can be factored into a product of geometric projection matrix and detector blurring matrix, where the former is often computed based on analytical calculation, and the latter is estimated using Monte Carlo simulations. In this work, we propose a method to estimate the 2D detector blurring matrix from experimental measurements. Point source data were acquired with high-count statistics in the microPET II scanner using a computer-controlled 2-D motion stage. A monotonically convergent iterative algorithm has been derived to estimate the detector blurring matrix from the point source measurements. The algorithm takes advantage of the rotational symmetry of the PET scanner with the modeling of the detector block structure. Since the resulting blurring matrix stems from actual measurements, it can take into account the physical effects in the photon detection process that are difficult or impossible to model in a Monte Carlo simulation. Reconstructed images of a line source phantom show improved resolution with the new detector blurring matrix compared to the original one from the Monte Carlo simulation. This method can be applied to other small-animal and clinical scanners.

  4. Low energy cyclotron production of multivalent transition metals for PET imaging and therapy

    Science.gov (United States)

    Avila-Rodriguez, Miguel Angel

    Recent advances in high-resolution tomographs for small animals require the production of nonconventional long-lived positron emitters to label novel radiopharmaceuticals for PET-based molecular imaging. Radioisotopes with an appropriate half life to match the kinetics of slow biological processes will allow to researchers to study the phamacokinetics of PET ligands over several hours, or even days, on the same animal, with the injection of a single dose. In addition, radionuclides with a suitable half life can potentially be distributed from a central production site making them available in PET facilities that lack an in-house cyclotron. In the last few years there has been a growing interest in the use of PET ligands labeled with radiometals, particularly isotopes of copper, yttrium and zirconium. Future clinical applications of these tracers will require them to be produced reliably and efficiently. This thesis work deals with implementing and optimizing the production of the multivalent transition metals 61,64Cu, 86Y and 89Zr for molecular PET imaging and therapy. Our findings in the production of these radionuclides at high specific activity on an 11 MeV proton-only cyclotron are presented. Local applications of these tracers, including Cu-ATSM for in vivo quantification of hypoxia, synthesis of targeted radiopharmaceuticals using activated esters of DOTA, and a novel development of positron emitting resin microspheres, are also be discussed. As a result of this thesis work, metallic radionuclides are now efficiently produced on a weekly basis in sufficient quality and quantity for collaborating scientists at UW-Madison and external users in other Universities across the country.

  5. 78 FR 27303 - Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food; Electron...

    Science.gov (United States)

    2013-05-10

    ...) in part 579 Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food (21...--IRRADIATION IN THE PRODUCTION, PROCESSING, AND HANDLING OF ANIMAL FEED AND PET FOOD 0 1. The authority... / Friday, May 10, 2013 / Rules and Regulations#0;#0; ] DEPARTMENT OF HEALTH AND HUMAN SERVICES Food...

  6. 78 FR 34565 - Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food; Electron...

    Science.gov (United States)

    2013-06-10

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 579 Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food; Electron Beam and X-Ray Sources for Irradiation of Poultry... THE PRODUCTION, PROCESSING, AND HANDLING OF ANIMAL FEED AND PET FOOD 0 1. The authority citation...

  7. Classification of bones from MR images in torso PET-MR imaging using a statistical shape model

    NARCIS (Netherlands)

    Ay, Mohammad Reza; Akbarzadeh, Afshin; Ahmadian, Alireza; Zaidi, Habib

    2014-01-01

    There have been exclusive features for hybrid PET/MRI systems in comparison with its PET/CT counterpart in terms of reduction of radiation exposure, improved soft-tissue contrast and truly simultaneous and multi-parametric imaging capabilities. However, quantitative imaging on PET/MR is challenged b

  8. SiliPET: Design of an ultra-high resolution small animal PET scanner based on stacks of semi-conductor detectors

    Science.gov (United States)

    Cesca, N.; Auricchio, N.; Di Domenico, G.; Zavattini, G.; Malaguti, R.; Andritschke, R.; Kanbach, G.; Schopper, F.

    2007-03-01

    We studied with Monte Carlo simulations, using the EGSnrc code, a new scanner for small animal positron emission tomography (PET), based on stacks of double-sided semiconductor detectors. Each stack is composed of planar detectors with dimension 70×60×1 mm 3 and orthogonal strips on both sides with 500 μm pitch to read the two interaction coordinates, the third being the detector number in the stack. Multiple interactions in a stack are discarded. In this way, we achieve a precise determination of the first interaction point of the two 511 keV photons. The reduced dimensions of the scanner also improve the solid angle coverage resulting in a high sensitivity. Preliminary results of scanners based on Si planar detectors are presented and the initial tomographic reconstructions demonstrate very good spatial resolution limited only by the positron range. This suggests that, this is a promising new approach for small animal PET imaging. We are testing some double-sided silicon detectors, equipped with 128 orthogonal p and n strips on opposite sides using VATAGP3 ASIC by IDEAS.

  9. SiliPET: Design of an ultra-high resolution small animal PET scanner based on stacks of semi-conductor detectors

    International Nuclear Information System (INIS)

    We studied with Monte Carlo simulations, using the EGSnrc code, a new scanner for small animal positron emission tomography (PET), based on stacks of double-sided semiconductor detectors. Each stack is composed of planar detectors with dimension 70x60x1 mm3 and orthogonal strips on both sides with 500 μm pitch to read the two interaction coordinates, the third being the detector number in the stack. Multiple interactions in a stack are discarded. In this way, we achieve a precise determination of the first interaction point of the two 511 keV photons. The reduced dimensions of the scanner also improve the solid angle coverage resulting in a high sensitivity. Preliminary results of scanners based on Si planar detectors are presented and the initial tomographic reconstructions demonstrate very good spatial resolution limited only by the positron range. This suggests that, this is a promising new approach for small animal PET imaging. We are testing some double-sided silicon detectors, equipped with 128 orthogonal p and n strips on opposite sides using VATAGP3 ASIC by IDEAS

  10. Small animal imaging. Basics and practical guide

    International Nuclear Information System (INIS)

    Small animal imaging has been recognized as an important tool in preclinical research. Nevertheless, the results of non-invasive imaging are often disappointing owing to choice of a suboptimal imaging modality and/or shortcomings in study design, experimental setup, and data evaluation. This textbook is a practical guide to the use of non-invasive imaging in preclinical research. Each of the available imaging modalities is discussed in detail, with the assistance of numerous informative illustrations. In addition, many useful hints are provided on the installation of a small animal unit, study planning, animal handling, and the cost-effective performance of small animal imaging. Cross-calibration methods, data postprocessing, and special imaging applications are also considered in depth. This is the first book to cover all the practical basics in small animal imaging, and it will prove an invaluable aid for researchers, students, and technicians. (orig.)

  11. Registration of chest PET and CT images. Fusion technique using the PET/Tr image by the respiration compensation

    International Nuclear Information System (INIS)

    The conventional registration of PET images of the chest with CT images is performed by rotating and shifting those images while used median lines and contours on axial images as the reference indexes. For the thoracic and the abdominal regions, therefore, the respiratory movements have prevented us from achieving satisfactory levels of registration reproducibility and accuracy. In order to solve this, we have analyzed respiratory movements of the chest and derived an image fusion method. Respiratory movements of the lung along each axis (X-axis: left-right, Y-axis: dorsoventral, and Z-axis: craniocaudal) during deep breathing were analyzed using CT-3D images. In addition, respiratory movements of the lung and thorax in the Y-axis and Z-axis directions during deep breathing and at rest were also analyzed by using an MR system that is the non-invasive method and allows for acquiring arbitrary tomographic images. Respiratory movements were compensated for on PET images of the lung. Moving average deviations in the Y-axis and Z-axis directions, which were obtained from the analytical result of respiration (30 samples), were used to derive the compensatory values. The analysis of CT-3D images showed that the movements in the X-axis direction were negligible. Registration of PET images with CT images was found useful when it performed on the sagittal planes. The analysis of MR images on sagittal planes revealed that the region extending from the apex of the lung to the posterior wall of the lung was useful for reference indexes for registration. The PET image by the compensation of the respiration transfer difference in the pulmonary hilum division was fusion on the CT image. In the pulmonary hilum division, the improvement in the accuracy of 3.6 mm in the dorsoventral and 6.1 mm in the craniocaudal direction was obtained in comparison with the fusion only of the reference index. The developed image fusion technique compensating the respiratory movements was found to be

  12. Spatial resolution and sensitivity of the Inveon small-animal PET scanner.

    NARCIS (Netherlands)

    Visser, E.P.; Disselhorst, J.; Brom, M.; Laverman, P.; Gotthardt, M.; Oyen, W.J.G.; Boerman, O.C.

    2009-01-01

    The Inveon small-animal PET scanner is characterized by a large, 127-mm axial length and a 161-mm crystal ring diameter. The associated high sensitivity is obtained by using all lines of response (LORs) up to the maximum ring difference (MRD) of 79, for which the most oblique LORs form acceptance an

  13. Accurate modeling of a DOI capable small animal PET scanner using GATE

    International Nuclear Information System (INIS)

    data confirms that the developed simulation setup is a useful tool for a wide range of research applications. - Highlights: ► We developed an MC model of the Argus (Sedecal) small-animal PET scanner using GATE. ► Validation was performed through comparison between simulated and experimental data. ► Spatial resolution, sensitivity and scatter fraction showed agreement within 7%. ► NEC was in excellent agreement at activities up to 50 MBq in the field of view. ► Image quality was also compared through the NEMA NU-4 phantom

  14. High resolution PET breast imager with improved detection efficiency

    Science.gov (United States)

    Majewski, Stanislaw

    2010-06-08

    A highly efficient PET breast imager for detecting lesions in the entire breast including those located close to the patient's chest wall. The breast imager includes a ring of imaging modules surrounding the imaged breast. Each imaging module includes a slant imaging light guide inserted between a gamma radiation sensor and a photodetector. The slant light guide permits the gamma radiation sensors to be placed in close proximity to the skin of the chest wall thereby extending the sensitive region of the imager to the base of the breast. Several types of photodetectors are proposed for use in the detector modules, with compact silicon photomultipliers as the preferred choice, due to its high compactness. The geometry of the detector heads and the arrangement of the detector ring significantly reduce dead regions thereby improving detection efficiency for lesions located close to the chest wall.

  15. {sup 11}C-Choline PET/pathology image coregistration in primary localized prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Grosu, Anca-Ligia; Prokic, Vesna [University of Freiburg, Department of Radiation Oncology, Freiburg (Germany); Technical University of Munich, Department of Radiation Oncology, Munich (Germany); Weirich, Gregor [Technical University of Munich, Institute of Pathology, Munich (Germany); Wendl, Christina; Geinitz, Hans; Molls, Michael [Technical University of Munich, Department of Radiation Oncology, Munich (Germany); Kirste, Simon [University of Freiburg, Department of Radiation Oncology, Freiburg (Germany); Souvatzoglou, Michael; Schwaiger, Markus [Technical University of Munich, Department of Nuclear Medicine, Munich (Germany); Gschwend, Juergen E.; Treiber, Uwe [Technical University of Munich, Department of Urology, Munich (Germany); Weber, Wolfgang A. [Memorial Sloan-Kettering Cancer Center, Molecular Imaging and Therapy Service, New York (United States); Krause, Bernd Joachim [Technical University of Munich, Department of Nuclear Medicine, Munich (Germany); University of Rostock, Department of Nuclear Medicine, Rostock (Germany)

    2014-12-15

    The aim of this study was to develop a methodology for the comparison of pathology specimens after prostatectomy (post-S) with PET images obtained before surgery (pre-S). This method was used to evaluate the merit of {sup 11}C-choline PET/CT for delineation of gross tumour volume (GTV) in prostate cancer (PC). In 28 PC patients, {sup 11}C-choline PET/CT was performed before surgery. PET/CT data were coregistered with the pathology specimens. GTV on PET images (GTV-PET) was outlined automatically and corrected manually. Tumour volume in the prostate (TVP) was delineated manually on the pathology specimens. Based on the coregistered PET/pathology images, the following parameters were assessed: SUVmax and SUVmean in the tumoral and nontumoral prostate (NP), GTV-PET (millilitres) and TVP (millilitres). PET/pathology image coregistration was satisfactory. Mean SUVmax in the TVP was lower than in the NP: 5.0 and 5.5, respectively (p = 0.093). Considering the entire prostate, SUVmax was located in the TVP in two patients, in the TVP and NP in 12 patients and exclusively in NP in 14 patients. Partial overlap the TVP and GTV-PET was seen in 71 % of patients, and complete overlap in 4 %. PET/pathology image coregistration can be used for evaluation of different imaging modalities. {sup 11}C-Choline PET failed to distinguish tumour from nontumour tissue. (orig.)

  16. Recent trends in Molecular Imaging : PET/CT in Neurology

    Directory of Open Access Journals (Sweden)

    R P Tripathi

    2015-06-01

    Full Text Available PET/CT is an important molecular imaging technique for the assessment ofneurological disorders. The most widely used radiopharmaceutical for both clinical and research purposes is [18F] 2-fluoro-2-deoxy-D-glucose (FDG. It is extensively used owing to its favourable physical characteristics. It enables depiction of cerebral glucose metabolism, and has thus been used to study various pathological states. Despite this, FDG has its own limitations. This is owing to its limited specificity and high cortical uptake. This has paved the way for the development of several non-FDG PET radiopharmaceuticals. We present the insights gained at our institution, using these radiotracers in the assessment of neurological disease. Our study shows that the use of FDG and non-FDG novel PET radiopharmaceuticals facilitates the early diagnosis, delineation of extent, prognostication and monitoring of therapeutic response in several neuropathological states.PET/CT is an important molecular imaging technique for the assessment ofneurological disorders. The most widely used radiopharmaceutical for both clinicaland research purposes is [18F] 2-fluoro-2-deoxy-D-glucose (FDG. It is extensivelyused owing to its favourable physical characteristics. It enables depiction of cerebralglucose metabolism, and has thus been used to study various pathological states.Despite this, FDG has its own limitations. This is owing to its limited specificity andhigh cortical uptake. This has paved the way for the development of several non-FDGPET radiopharmaceuticals. We present the insights gained at our institution, usingthese radiotracers in the assessment of neurological disease. Our study shows that theuse of FDG and non-FDG novel PET radiopharmaceuticals facilitates the earlydiagnosis, delineation of extent, prognostication and monitoring of therapeuticresponse in several neuropathological states.

  17. Peritoneal Lymphomatosis Imaged by F-18 FDG PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun Kyung; Lee, Se Ryeon; Kim, Young Chul; Oh, Sun Young; Choe, Jae Gol [Korea University Anam Hospital, Seoul (Korea, Republic of)

    2010-06-15

    Peritoneal lymphomatosis is uncommon, but when encountered is associated with aggressive histological subtypes of high-grade lymphoma, such as small-cell, large-cell, mixed large and small cell, non-cleaved, lymphoblastic Burkitt-like, and diffuse large B-cell lymphomas. The CT findings of peritoneal lymphomatosis are linear or nodular peritoneal thickening, retroperitoneal lymphadenopathy, omental and mesenteric involvement with streak-like infiltrations or a bulky mass, bowel wall thickening, hepatosplenomegaly, and ascites. The authors reports report the first FDG PET/CT images of diffuse large B-cell lymphoma of small bowel origin associated with peritoneal lymphomatosis in a 69-year-old man. The lesions demonstrated intense FDG uptake in PET/CT images.

  18. Assessment of MR-compatibility of SiPM PET insert using short optical fiber bundles for small animal research

    International Nuclear Information System (INIS)

    Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) can provide new perspectives in human disease research because of their complementary in-vivo imaging techniques. Previously, we have developed an MR-compatible PET insert based on optical fibers using silicon photomultipliers (SiPM). However when echo planar imaging (EPI) sequence was performed, signal intensity was slowly decreased by −0.9% over the 5.5 minutes and significant geometrical distortion was observed as the PET insert was installed inside an MRI bore, indicating that the PET electronics and its shielding boxes might have been too close to an MR imaging object. In this paper, optical fiber bundles with a length of 54 mm instead of 31 mm were employed to minimize PET interference on MR images. Furthermore, the LYSO crystals with a size of 1.5 × 1.5 × 7.0 mm3 were used instead of 2.47 × 2.74 × 20.0 mm3 for preclinical PET/MR applications. To improve the MR image quality, two receive-only loop coils were used. The effects of the PET insert on the SNR of the MR image either for morphological or advanced MR pulse sequences such as diffusion weighted imaging (DWI), functional MRI (fMRI), and magnetic resonance spectroscopy (MRS) were investigated. The quantitative MR compatibility such as B0 and B1 field homogeneity without PET, with 'PET OFF', and with 'PET ON' was also evaluated. In conclusion, B0 maps were not affected by the proposed PET insert whereas B1 maps were significantly affected by the PET insert. The advanced MRI sequences such as DWI, EPI, and MRS can be performed without a significant MR image quality degradation

  19. Assessment of MR-compatibility of SiPM PET insert using short optical fiber bundles for small animal research

    Science.gov (United States)

    Kang, H. G.; Hong, S. J.; Ko, G. B.; Yoon, H. S.; Song, I. C.; Rhee, J. T.; Lee, J. S.

    2015-12-01

    Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) can provide new perspectives in human disease research because of their complementary in-vivo imaging techniques. Previously, we have developed an MR-compatible PET insert based on optical fibers using silicon photomultipliers (SiPM). However when echo planar imaging (EPI) sequence was performed, signal intensity was slowly decreased by -0.9% over the 5.5 minutes and significant geometrical distortion was observed as the PET insert was installed inside an MRI bore, indicating that the PET electronics and its shielding boxes might have been too close to an MR imaging object. In this paper, optical fiber bundles with a length of 54 mm instead of 31 mm were employed to minimize PET interference on MR images. Furthermore, the LYSO crystals with a size of 1.5 × 1.5 × 7.0 mm3 were used instead of 2.47 × 2.74 × 20.0 mm3 for preclinical PET/MR applications. To improve the MR image quality, two receive-only loop coils were used. The effects of the PET insert on the SNR of the MR image either for morphological or advanced MR pulse sequences such as diffusion weighted imaging (DWI), functional MRI (fMRI), and magnetic resonance spectroscopy (MRS) were investigated. The quantitative MR compatibility such as B0 and B1 field homogeneity without PET, with `PET OFF', and with `PET ON' was also evaluated. In conclusion, B0 maps were not affected by the proposed PET insert whereas B1 maps were significantly affected by the PET insert. The advanced MRI sequences such as DWI, EPI, and MRS can be performed without a significant MR image quality degradation.

  20. Motion compensation for PET image reconstruction using deformable tetrahedral meshes

    International Nuclear Information System (INIS)

    Respiratory-induced organ motion is a technical challenge to PET imaging. This motion induces displacements and deformation of the organs tissues, which need to be taken into account when reconstructing the spatial radiation activity. Classical image-based methods that describe motion using deformable image registration (DIR) algorithms cannot fully take into account the non-reproducibility of the respiratory internal organ motion nor the tissue volume variations that occur during breathing. In order to overcome these limitations, various biomechanical models of the respiratory system have been developed in the past decade as an alternative to DIR approaches. In this paper, we describe a new method of correcting motion artefacts in PET image reconstruction adapted to motion estimation models such as those based on the finite element method. In contrast with the DIR-based approaches, the radiation activity was reconstructed on deforming tetrahedral meshes. For this, we have re-formulated the tomographic reconstruction problem by introducing a time-dependent system matrix based calculated using tetrahedral meshes instead of voxelized images. The MLEM algorithm was chosen as the reconstruction method. The simulations performed in this study show that the motion compensated reconstruction based on tetrahedral deformable meshes has the capability to correct motion artefacts. Results demonstrate that, in the case of complex deformations, when large volume variations occur, the developed tetrahedral based method is more appropriate than the classical DIR-based one. This method can be used, together with biomechanical models controlled by external surrogates, to correct motion artefacts in PET images and thus reducing the need for additional internal imaging during the acquisition. (paper)

  1. Synthesis of fluorine-18 radio-labeled serum albumins for PET blood pool imaging

    International Nuclear Information System (INIS)

    We sought to develop a practical, reproducible and clinically translatable method of radiolabeling serum albumins with fluorine-18 for use as a PET blood pool imaging agent in animals and man. Fluorine-18 radiolabeled fluoronicotinic acid-2,3,5,6-tetrafluorophenyl ester, [18F]F-Py-TFP was prepared first by the reaction of its quaternary ammonium triflate precursor with [18F]tetrabutylammonium fluoride ([18F]TBAF) according to a previously published method for peptides, with minor modifications. The incubation of [18F]F-Py-TFP with rat serum albumin (RSA) in phosphate buffer (pH 9) for 15 min at 37–40 °C produced fluorine-18-radiolabeled RSA and the product was purified using a mini-PD MiniTrap G-25 column. The overall radiochemical yield of the reaction was 18–35% (n = 30, uncorrected) in a 90-min synthesis. This procedure, repeated with human serum albumin (HSA), yielded similar results. Fluorine-18-radiolabeled RSA demonstrated prolonged blood retention (biological half-life of 4.8 hours) in healthy awake rats. The distribution of major organ radioactivity remained relatively unchanged during the 4 hour observation periods either by direct tissue counting or by dynamic PET whole-body imaging except for a gradual accumulation of labeled metabolic products in the bladder. This manual method for synthesizing radiolabeled serum albumins uses fluorine-18, a widely available PET radionuclide, and natural protein available in both pure and recombinant forms which could be scaled up for widespread clinical applications. These preclinical biodistribution and PET imaging results indicate that [18F]RSA is an effective blood pool imaging agent in rats and might, as [18F]HSA, prove similarly useful as a clinical imaging agent

  2. Biodistribution and PET imaging of [{sup 18}F]-fluoroadenosine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Alauddin, Mian M. [Department of Radiology, PET Imaging Science Center, University of Southern California, Los Angeles, CA 90033 (United States)]. E-mail: alauddin@di.mdacc.tmc.edu; Shahinian, Antranik [Department of Radiology, PET Imaging Science Center, University of Southern California, Los Angeles, CA 90033 (United States); Park, Ryan [Department of Radiology, PET Imaging Science Center, University of Southern California, Los Angeles, CA 90033 (United States); Tohme, Michael [Department of Radiology, PET Imaging Science Center, University of Southern California, Los Angeles, CA 90033 (United States); Fissekis, John D. [Department of Radiology, PET Imaging Science Center, University of Southern California, Los Angeles, CA 90033 (United States); Conti, Peter S. [Department of Radiology, PET Imaging Science Center, University of Southern California, Los Angeles, CA 90033 (United States)

    2007-04-15

    Introduction: Many fluorinated analogues of adenosine nucleoside have been synthesized and studied as potential antitumor and antiviral agents. Earlier, we reported radiosynthesis of 2'-deoxy-2'-[{sup 18}F]fluoro-1-{beta}-D-arabinofuranosyl-adenine ([{sup 18}F]-FAA) and 3'-deoxy-3'-[{sup 18}F]fluoro-1-{beta}-D-xylofuranosyl-adenine ([{sup 18}F]FXA). Now, we report their in vivo studies including blood clearance, biodistribution and micro-PET imaging in tumor-bearing nude mice. Methods: Tumors were grown in 6-week-old athymic nude mice (Harlan, Indianapolis, IN, USA) by inoculation of HT-29 cells, wild-type cells in the left flank and transduced cells with HSV-tk on the right flank. When the tumor was about 1 cm in size, animals were injected with these radiotracers for in vivo studies, including blood clearance, micro-PET imaging and biodistribution. Results: Uptake of [{sup 18}F]FAA in tumor was 3.3-fold higher than blood, with highest uptake in the spleen. Maximum uptake of [{sup 18}F]FXA was observed in the heart compared to other organs. There was no tumor uptake of [{sup 18}F]FXA. Biodistribution results were supported by micro-PET images, which also showed very high uptake of [{sup 18}F]FAA in spleen and visualization of tumors, and high uptake of [{sup 18}F]FXA in the heart. Conclusion: These results suggest that [{sup 18}F]FAA may be useful for tumor imaging, while [{sup 18}F]FXA may have potential as a heart imaging agent with PET.

  3. Anatomic and functional imaging of tagged molecules in animals

    Science.gov (United States)

    Weisenberger, Andrew G.; Majewski, Stanislaw; Paulus, Michael J.; Gleason, Shaun S.

    2007-04-24

    A novel functional imaging system for use in the imaging of unrestrained and non-anesthetized small animals or other subjects and a method for acquiring such images and further registering them with anatomical X-ray images previously or subsequently acquired. The apparatus comprises a combination of an IR laser profilometry system and gamma, PET and/or SPECT, imaging system, all mounted on a rotating gantry, that permits simultaneous acquisition of positional and orientational information and functional images of an unrestrained subject that are registered, i.e. integrated, using image processing software to produce a functional image of the subject without the use of restraints or anesthesia. The functional image thus obtained can be registered with a previously or subsequently obtained X-ray CT image of the subject. The use of the system described herein permits functional imaging of a subject in an unrestrained/non-anesthetized condition thereby reducing the stress on the subject and eliminating any potential interference with the functional testing that such stress might induce.

  4. Effect of MR contrast agents on quantitative accuracy of PET in combined whole-body PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lois, Cristina [University of Santiago de Compostela, Department of Particle Physics, Santiago de Compostela (Spain); Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela (Spain); Imaging Science Institute, Tuebingen (Germany); Bezrukov, Ilja [Eberhard Karls University, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens Foundation, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Max Plank Institute for Intelligent Systems, Department of Empirical Inference, Tuebingen (Germany); Schmidt, Holger [Eberhard Karls University, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens Foundation, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Eberhard Karls University, Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Schwenzer, Nina; Werner, Matthias K. [Eberhard Karls University, Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Kupferschlaeger, Juergen [Eberhard Karls University, Nuclear Medicine, Department of Radiology, Tuebingen (Germany); Beyer, Thomas [Imaging Science Institute, Tuebingen (Germany); cmi-experts GmbH, Zuerich (Switzerland)

    2012-11-15

    Clinical PET/MR acquisition protocols entail the use of MR contrast agents (MRCA) that could potentially affect PET quantification following MR-based attenuation correction (AC). We assessed the effect of oral and intravenous (IV) MRCA on PET quantification in PET/MR imaging. We employed two MRCA: Lumirem {sup registered} (oral) and Gadovist {sup registered} (IV). First, we determined their reference PET attenuation values using a PET transmission scan (ECAT-EXACT HR+, Siemens) and a CT scan (PET/CT Biograph 16 HI-REZ, Siemens). Second, we evaluated the attenuation of PET signals in the presence of MRCA. Phantoms were filled with clinically relevant concentrations of MRCA in a background of water and {sup 18}F-fluoride, and imaged using a PET/CT scanner (Biograph 16 HI-REZ, Siemens) and a PET/MR scanner (Biograph mMR, Siemens). Third, we investigated the effect of clinically relevant volumes of MRCA on MR-based AC using human pilot data: a patient study employing Gadovist {sup registered} (IV) and a volunteer study employing two different oral MRCA (Lumirem {sup registered} and pineapple juice). MR-based attenuation maps were calculated following Dixon-based fat-water segmentation and an external atlas-based and pattern recognition (AT and PR) algorithm. IV and oral MRCA in clinically relevant concentrations were found to have PET attenuation values similar to those of water. The phantom experiments showed that under clinical conditions IV and oral MRCA did not yield additional attenuation of PET emission signals. Patient scans showed that PET attenuation maps are not biased after the administration of IV MRCA but may be biased, however, after ingestion of iron oxide-based oral MRCA when segmentation-based AC algorithms are used. Alternative AC algorithms, such as AT and PR, or alternative oral contrast agents, such as pineapple juice, can yield unbiased attenuation maps. In clinical PET/MR scenarios MRCA are not expected to lead to markedly increased attenuation

  5. Effect of MR contrast agents on quantitative accuracy of PET in combined whole-body PET/MR imaging

    International Nuclear Information System (INIS)

    Clinical PET/MR acquisition protocols entail the use of MR contrast agents (MRCA) that could potentially affect PET quantification following MR-based attenuation correction (AC). We assessed the effect of oral and intravenous (IV) MRCA on PET quantification in PET/MR imaging. We employed two MRCA: Lumirem registered (oral) and Gadovist registered (IV). First, we determined their reference PET attenuation values using a PET transmission scan (ECAT-EXACT HR+, Siemens) and a CT scan (PET/CT Biograph 16 HI-REZ, Siemens). Second, we evaluated the attenuation of PET signals in the presence of MRCA. Phantoms were filled with clinically relevant concentrations of MRCA in a background of water and 18F-fluoride, and imaged using a PET/CT scanner (Biograph 16 HI-REZ, Siemens) and a PET/MR scanner (Biograph mMR, Siemens). Third, we investigated the effect of clinically relevant volumes of MRCA on MR-based AC using human pilot data: a patient study employing Gadovist registered (IV) and a volunteer study employing two different oral MRCA (Lumirem registered and pineapple juice). MR-based attenuation maps were calculated following Dixon-based fat-water segmentation and an external atlas-based and pattern recognition (AT and PR) algorithm. IV and oral MRCA in clinically relevant concentrations were found to have PET attenuation values similar to those of water. The phantom experiments showed that under clinical conditions IV and oral MRCA did not yield additional attenuation of PET emission signals. Patient scans showed that PET attenuation maps are not biased after the administration of IV MRCA but may be biased, however, after ingestion of iron oxide-based oral MRCA when segmentation-based AC algorithms are used. Alternative AC algorithms, such as AT and PR, or alternative oral contrast agents, such as pineapple juice, can yield unbiased attenuation maps. In clinical PET/MR scenarios MRCA are not expected to lead to markedly increased attenuation of the PET emission signals. MR

  6. Enclosure for small animals during awake animal imaging

    Science.gov (United States)

    Goddard, Jr., James S

    2013-11-26

    An enclosure or burrow restrains an awake animal during an imaging procedure. A tubular body, made from a radiolucent material that does not attenuate x-rays or gamma rays, accepts an awake animal. A proximal end of the body includes an attachment surface that corresponds to an attachment surface of an optically transparent and optically uniform window. An anti-reflective coating may be applied to an inner surface, an outer surface, or both surfaces of the window. Since the window is a separate element of the enclosure and it is not integrally formed as part of the body, it can be made with optically uniform thickness properties for improved motion tracking of markers on the animal with a camera during the imaging procedure. The motion tracking information is then used to compensate for animal movement in the image.

  7. Imaging of Tumor Metabolism Using Positron Emission Tomography (PET).

    Science.gov (United States)

    Apostolova, Ivayla; Wedel, Florian; Brenner, Winfried

    2016-01-01

    Molecular imaging employing PET/CT enables in vivo visualization, characterization, and measurement of biologic processes in tumors at a molecular and cellular level. Using specific metabolic tracers, information about the integrated function of multiple transporters and enzymes involved in tumor metabolic pathways can be depicted, and the tracers can be directly applied as biomarkers of tumor biology. In this review, we discuss the role of F-18-fluorodeoxyglucose (FDG) as an in vivo glycolytic marker which reflects alterations of glucose metabolism in cancer cells. This functional molecular imaging technique offers a complementary approach to anatomic imaging such as computed tomography (CT) and magnetic resonance imaging (MRI) and has found widespread application as a diagnostic modality in oncology to monitor tumor biology, optimize the therapeutic management, and guide patient care. Moreover, emerging methods for PET imaging of further biologic processes relevant to cancer are reviewed, with a focus on tumor hypoxia and aberrant tumor perfusion. Hypoxic tumors are associated with poor disease control and increased resistance to cytotoxic and radiation treatment. In vivo imaging of hypoxia, perfusion, and mismatch of metabolism and perfusion has the potential to identify specific features of tumor microenvironment associated with poor treatment outcome and, thus, contribute to personalized treatment approaches. PMID:27557539

  8. Performance evaluation of SiPM photodetectors for PET imaging in the presence of magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Espana, S., E-mail: samuel@nuclear.fis.ucm.e [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Fraile, L.M.; Herraiz, J.L.; Udias, J.M. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Desco, M.; Vaquero, J.J. [Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain)

    2010-02-01

    The multi-pixel photon counter (MPPC) or silicon photomultiplier (SiPM), recently introduced as a solid-state photodetector, consists of an array of Geiger-mode photodiodes (microcells). It is a promising device for PET due to its potential for high photon detection efficiency (PDE) and its foreseeable immunity to magnetic fields. It is also easy to use with simple read-outs, has a high gain and a small size. In this work we evaluate the in field performance of three 1x1 mm{sup 2} (with 100, 400 and 1600 microcells, respectively) and one 6x6 mm{sup 2} (arranged as a 2x2 array) Hamamatsu MPPCs for their use in PET imaging. We examine the dependence of the energy resolution and the gain of these devices on the temperature and reverse bias voltage, when coupled to LYSO scintillator crystals under conditions that one would find in a PET system. We find that the 400 and 1600 microcells models and the 2x2 array are suitable for small-size crystals, like those employed in high resolution small animal scanners. We have confirmed the good performance of these devices up to magnetic fields of 7 T as well as their suitability for performing PET acquisitions in the presence of fast switching gradients and high duty radiofrequency MRI sequences.

  9. Clinical, FDG and amyloid PET imaging in posterior cortical atrophy.

    Science.gov (United States)

    Singh, Tarun D; Josephs, Keith A; Machulda, Mary M; Drubach, Daniel A; Apostolova, Liana G; Lowe, Val J; Whitwell, Jennifer L

    2015-06-01

    The purpose of this study was to identify the clinical, [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) and amyloid-PET findings in a large cohort of posterior cortical atrophy (PCA) patients, to examine the neural correlates of the classic features of PCA, and to better understand the features associated with early PCA. We prospectively recruited 25 patients who presented to the Mayo Clinic between March 2013 and August 2014 and met diagnostic criteria for PCA. All patients underwent a standardized set of tests and amyloid imaging with [(11)C] Pittsburg compound B (PiB). Seventeen (68 %) underwent FDG-PET scanning. We divided the cohort at the median disease duration of 4 years in order to assess clinical and FDG-PET correlates of early PCA (n = 13). The most common clinical features were simultanagnosia (92 %), dysgraphia (68 %), poly-mini-myoclonus (64 %) and oculomotor apraxia (56.5 %). On FDG-PET, hypometabolism was observed bilaterally in the lateral and medial parietal and occipital lobes. Simultanagnosia was associated with hypometabolism in the right occipital lobe and posterior cingulum, optic ataxia with hypometabolism in left occipital lobe, and oculomotor apraxia with hypometabolism in the left parietal lobe and posterior cingulate gyrus. All 25 PCA patients were amyloid positive. Simultanagnosia was the only feature present in 85 % of early PCA patients. The syndrome of PCA is associated with posterior hemisphere hypometabolism and with amyloid deposition. Many of the classic features of PCA show associated focal, but not widespread, areas of involvement of these posterior hemispheric regions. Simultanagnosia appears to be the most common and hence sensitive feature of early PCA. PMID:25862483

  10. PET imaging with the non-pure positron emitters: 55Co, 86Y and 124I

    DEFF Research Database (Denmark)

    Braad, Poul-Erik; Hansen, S B; Thisgaard, H;

    2015-01-01

    PET/CT with non-pure positron emitters is a highly valuable tool in immuno-PET and for pretherapeutic dosimetry. However, imaging is complicated by prompt gamma coincidences (PGCs) that add an undesired background activity to the images. Time-of-flight (TOF) reconstruction improves lesion...... detectability in 18F-PET and can potentially also improve the signal-to-noise ratio in images acquired with non-pure positron emitters. Using the GE Discovery 690 PET/CT system, we evaluated the image quality with 55Co, 86Y and 124I, and the effect of PGC-correction and TOF-reconstruction on image quality...

  11. PET tracers for somatostatin receptor imaging of neuroendocrine tumors

    DEFF Research Database (Denmark)

    Johnbeck, Camilla Bardram; Knigge, Ulrich; Kjær, Andreas

    2014-01-01

    Neuroendocrine tumors have shown rising incidence mainly due to higher clinical awareness and better diagnostic tools over the last 30 years. Functional imaging of neuroendocrine tumors with PET tracers is an evolving field that is continuously refining the affinity of new tracers in the search...... for the perfect neuroendocrine tumor imaging tracer. (68)Ga-labeled tracers coupled to synthetic somatostatin analogs with differences in affinity for the five somatostatin receptor subtypes are now widely applied in Europe. Comparison of sensitivity between the most used tracers - (68)Ga-DOTA-Tyr3-octreotide...

  12. In vivo imaging of brain androgen receptors in rats: a [18F]FDHT PET study

    International Nuclear Information System (INIS)

    Introduction: Steroid hormones like androgens play an important role in the development and maintenance of several brain functions. Androgens can act through androgen receptors (AR) in the brain. This study aims to demonstrate the feasibility of positron emission tomography (PET) with 16β-[18F]fluoro-5α-dihydrotestosterone ([18F]FDHT) to image AR expression in the brain. Methods: Male Wistar rats were either orchiectomized to inhibit endogenous androgen production or underwent sham-surgery. Fifteen days after surgery, rats were subjected to a 90-min dynamic [18F]FDHT PET scan with arterial blood sampling. In a subset of orchiectomized rats, 1 mg/kg dihydrotestosterone was co-injected with the tracer in order to saturate the AR. Plasma samples were analyzed for the presence of radioactive metabolites by radio-TLC. Pharmacokinetic modeling was performed to quantify brain kinetics of the tracer. After the PET scan, the animals were terminated for ex-vivo biodistribution. Results: PET imaging and ex vivo biodistribution studies showed low [18F]FDHT uptake in all brain regions, except pituitary. [18F]FDHT uptake in the surrounding cranial bones was high and increased over time. [18F]FDHT was rapidly metabolized in rats. Metabolism was significantly faster in orchiectomized rats than in sham-orchiectomized rats. Quantitative analysis of PET data indicated substantial spill-over of activity from cranial bones into peripheral brain regions, which prevented further analysis of peripheral brain regions. Logan graphical analysis and kinetic modeling using 1- and 2-tissue compartment models showed reversible and homogenously distributed tracer uptake in central brain regions. [18F]FDHT uptake in the brain could not be blocked by endogenous androgens or administration of dihydrotestosterone. Conclusion: The results of this study indicate that imaging of AR availability in rat brain with [18F]FDHT PET is not feasible. The low AR expression in the brain, the rapid metabolism of

  13. PET imaging in pediatric Hodgkin's lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, M.M. [Dept. of Hematology-Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Krasin, M.J. [Dept. of Radiological Sciences, Div. of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States); Kaste, S.C. [Dept. of Radiological Sciences, Div. of Diagnostic Imaging, St. Jude Children' s Research Hospital, Memphis, TN (United States); Dept. of Radiology, Coll. of Medicine, Univ. of Tennessee Health Science Center, Memphis, TN (United States)

    2004-03-01

    Advances in diagnostic imaging technology, especially functional imaging modalities like positron emission tomography (PET), have significantly influenced the staging and treatment approaches used for pediatric Hodgkin's lymphoma. Today, the majority of children and adolescents diagnosed with Hodgkin's lymphoma will be cured following treatment with noncross-resistant combination chemotherapy alone or in combination with low-dose, involved-field radiation. This success produced a greater appreciation of long-term complications related to radiation, chemotherapy, and surgical staging that prompted significant changes in staging and treatment protocols for children and adolescents with Hodgkin's lymphoma. Contemporary treatment for pediatric Hodgkin's lymphoma uses a risk-adapted approach that reduces the number of combination chemotherapy cycles and radiation treatment fields and doses for patients with localized favorable disease presentation. Advances in diagnostic imaging technology have played a critical role in the development of these risk-adapted treatment regimens. The introduction of computed tomography (CT) provided an accurate and non-invasive modality to define nodal involvement below the diaphragm that motivated the change from surgical to clinical staging. The introduction of functional imaging modalities, like positron emission tomography (PET) scanning, provided the means to correlate tumor activity with anatomic features generated by CT and modify treatment based on tumor response. For centers with access to this modality, PET imaging plays an important role in staging, evaluating tumor response, planning radiation treatment fields, and monitoring after completion of therapy for pediatric Hodgkin's lymphoma. (orig.)

  14. Imaging the Gastrointestinal Tract of Small Animals

    OpenAIRE

    Jelicks, Linda A.

    2010-01-01

    Animal models of human diseases are increasingly available and are invaluable for studies of organ pathophysiology. Megacolon, abnormal dilatation of the colon not caused by mechanical obstruction, involves the destruction of the autonomic nervous system innervating the colon. Animal models of megacolon include mouse models of Chagas disease and Hirschprung’s disease. Small animal imaging has become an important research tool and recent advances in preclinical imaging modalities have enhanced...

  15. Investigation of optimization-based reconstruction with an image-total-variation constraint in PET

    Science.gov (United States)

    Zhang, Zheng; Ye, Jinghan; Chen, Buxin; Perkins, Amy E.; Rose, Sean; Sidky, Emil Y.; Kao, Chien-Min; Xia, Dan; Tung, Chi-Hua; Pan, Xiaochuan

    2016-08-01

    Interest remains in reconstruction-algorithm research and development for possible improvement of image quality in current PET imaging and for enabling innovative PET systems to enhance existing, and facilitate new, preclinical and clinical applications. Optimization-based image reconstruction has been demonstrated in recent years of potential utility for CT imaging applications. In this work, we investigate tailoring the optimization-based techniques to image reconstruction for PET systems with standard and non-standard scan configurations. Specifically, given an image-total-variation (TV) constraint, we investigated how the selection of different data divergences and associated parameters impacts the optimization-based reconstruction of PET images. The reconstruction robustness was explored also with respect to different data conditions and activity up-takes of practical relevance. A study was conducted particularly for image reconstruction from data collected by use of a PET configuration with sparsely populated detectors. Overall, the study demonstrates the robustness of the TV-constrained, optimization-based reconstruction for considerably different data conditions in PET imaging, as well as its potential to enable PET configurations with reduced numbers of detectors. Insights gained in the study may be exploited for developing algorithms for PET-image reconstruction and for enabling PET-configuration design of practical usefulness in preclinical and clinical applications.

  16. A 16-channel MR coil for simultaneous PET/MR imaging in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dregely, Isabel [Klinikum rechts der Isar der Technischen Universitaet Muenchen, Nuklearmedizinische Klinik, Munich (Germany); Department of Radiological Sciences, Los Angeles, CA (United States); Lanz, Titus; Mueller, Matthias F. [Rapid Biomedical GmbH, Rimpar (Germany); Metz, Stephan [Klinikum rechts der Isar der Technischen Universitaet Muenchen, Institut fuer diagnostische und interventionelle Radiologie, Munich (Germany); Kuschan, Marika [Klinikum rechts der Isar der Technischen Universitaet Muenchen, Nuklearmedizinische Klinik, Munich (Germany); IMETUM, Technische Universitaet Muenchen, Munich (Germany); Nimbalkar, Manoj; Ziegler, Sibylle I.; Nekolla, Stephan G.; Schwaiger, Markus [Klinikum rechts der Isar der Technischen Universitaet Muenchen, Nuklearmedizinische Klinik, Munich (Germany); Bundschuh, Ralph A. [Klinikum rechts der Isar der Technischen Universitaet Muenchen, Nuklearmedizinische Klinik, Munich (Germany); Universitaetsklinikum Bonn, Nuklearmedizinische Klinik, Bonn (Germany); Haase, Axel [IMETUM, Technische Universitaet Muenchen, Munich (Germany)

    2015-04-01

    To implement and evaluate a dedicated receiver array coil for simultaneous positron emission tomography/magnetic resonance (PET/MR) imaging in breast cancer. A 16-channel receiver coil design was optimized for simultaneous PET/MR imaging. To assess MR performance, the signal-to-noise ratio, parallel imaging capability and image quality was evaluated in phantoms, volunteers and patients and compared to clinical standard protocols. For PET evaluation, quantitative {sup 18} F-FDG PET images of phantoms and seven patients (14 lesions) were compared to images without the coil. In PET image reconstruction, a CT-based template of the coil was combined with the MR-acquired attenuation correction (AC) map of the phantom/patient. MR image quality was comparable to clinical MR-only examinations. PET evaluation in phantoms showed regionally varying underestimation of the standardised uptake value (SUV; mean 22 %) due to attenuation caused by the coil. This was improved by implementing the CT-based coil template in the AC (<2 % SUV underestimation). Patient data indicated that including the coil in the AC increased the SUV values in the lesions (21 ± 9 %). Using a dedicated PET/MR breast coil, state-of-the-art MRI was possible. In PET, accurate quantification and image homogeneity could be achieved if a CT-template of this coil was included in the AC for PET image reconstruction. (orig.)

  17. A PET imaging system dedicated to mammography

    CERN Document Server

    Varela, J

    2007-01-01

    The imaging system Clear-PEM for positron emission mammography, under development within the framework of the Crystal Clear Collaboration at CERN, is presented. The detector is based on pixelized LYSO crystals optically coupled to avalanche photodiodes (APD) and readout by a fast low-noise electronic system. A dedicated digital trigger and data acquisition system is used for on-line selection of coincidence events with high efficiency, large bandwidth and negligible dead-time. The detector module performance was characterized in detail.

  18. Imaging optimizations with non-pure and high-energy positron emitters in small animal positron computed tomography

    International Nuclear Information System (INIS)

    The contribution on imaging optimizations with non-pure and high-energy positron emitters in small animal positron emission tomography (PET) covers the following topics: physical fundamentals of PET, mathematical image reconstruction and data analyses, Monte-Carlo simulations and implemented correction scheme, quantification of cascade gamma coincidences based on simulations and measurements, sinogram based corrections, restoration of the spatial resolution, implementation of full corrections.

  19. Radiation protection in an animal research unit with pet: Occupational doses and dose rates produced by animals

    International Nuclear Information System (INIS)

    This study focuses on the occupational doses of technologists working at an Animal Research Unit using PET radiotracers and on the environmental dose rates produced by the animals (mice, rats and monkeys). In particular, whole body and extremity monitoring is reported and related with the workload. The study shows that doses not only depend on the amount of activity injected but also on the type of animals and radiotracers managed. The extremities, with a great variability of the doses received, are the limiting organs as far as regulatory dose limits for workers are concerned. Mean H∗(10) rates in contact and at 20 cm from the animals, when they are handled by the technologist, range from around 1 mSv/h to 20 μSv/h, respectively.

  20. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chuan; Brady, Thomas J.; El Fakhri, Georges; Ouyang, Jinsong, E-mail: ouyang.jinsong@mgh.harvard.edu [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Ackerman, Jerome L. [Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Petibon, Yoann [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

    2014-04-15

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic{sup 18}F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R{sup 2} = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast.

  1. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    International Nuclear Information System (INIS)

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic18F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R2 = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast

  2. Comparison of imaging with FDG PET/CT with other imaging modalities in myeloma

    Energy Technology Data Exchange (ETDEWEB)

    Breyer, Richard J. [University of Maryland Medical Center, Department of Radiology, Baltimore, MD (United States); University of Maryland Medical Center, Division of Nuclear Medicine, Baltimore, MD (United States); Mulligan, Michael E.; Smith, Stacy E. [University of Maryland Medical Center, Department of Radiology, Baltimore, MD (United States); Line, Bruce R. [University of Maryland Medical Center, Division of Nuclear Medicine, Baltimore, MD (United States); Badros, Ashraf Z. [University of Maryland Medical Center, Marlene and Stewart Greenebaum Cancer Center, Baltimore, MD (United States)

    2006-09-15

    To determine the usefulness of FDG PET/CT scanning in the management and staging of myeloma and to assess its strengths and limitations. FDG PET/CT scans and all other available imaging studies were reviewed retrospectively from 16 consecutive patients by two experienced musculoskeletal radiologists and two nuclear medicine physicians working in consensus. The 16 patients had undergone a total of 19 FDG PET/CT scans. Radiographs were available in all cases, including 13 skeletal surveys; 25 CT scans (16 chest, three abdominal, four pelvic, one spine, one neck) and 22 MR imaging studies (17 spine, three pelvic, two extremity) also were reviewed. Patients' records were examined for relevant clinical information. All focal areas of abnormal FDG uptake were correlated with the other imaging studies to determine clinical significance. FDG PET/CT scans also were reviewed to see if small lesions shown on the other imaging studies could be identified in retrospect. The 12 men and four women had an average age of 58 years (range 30-69 years). All 16 patients had an established diagnosis of multiple myeloma, with average duration of disease, from time of initial diagnosis to review, of 30 months (range 6 months to 11+ years). The FDG PET/CT scans revealed a total of 104 sites (90 in bone, 14 soft tissue) that were suspicious for neoplastic activity based on a standardized uptake value (SUV) greater than 2.5. Fifty-seven of these sites (55%) were new or previously undetected. The other imaging studies (X-ray, CT, MR) and clinical information confirmed the other 47 areas but also revealed 133 other small skeletal lesions. Six of these 133 additional lesions showed mild FDG uptake on re-review of the PET/CT scans. The FDG PET/CT findings led to management changes in 9/16 patients. MR imaging revealed five cases of diffuse bone involvement (four spine, one scapula) that were not evident by FDG PET/CT. FDG PET/CT scans are useful for the management and staging of myeloma

  3. Prostate Cancer Imaging with Novel PET Tracers.

    Science.gov (United States)

    Lindenberg, Liza; Choyke, Peter; Dahut, William

    2016-03-01

    Molecular imaging of prostate cancer is in a dynamic phase of development. Currently approved techniques are limited and researchers have been working on novel agents to improve accuracy in targeting and detecting prostate tumors. In addition, the complexity of various prostate cancer states also contributes to the challenges in evaluating suitable radiotracer candidates. We have highlighted nuclear medicine tracers that focus on mechanisms involved in bone metastasis, prostate cancer cell membrane synthesis, amino acid analogs, androgen analogs, and the prostate specific membrane antigen. Encouraging results with many of these innovative radiotracer compounds will not only advance diagnostic capabilities for prostate cancer but open opportunities for theranostic applications to treat this worldwide malignancy. PMID:26874530

  4. Automatic detection of radioactive fixations in oncology PET images

    International Nuclear Information System (INIS)

    Therapeutic follow-up of patients with cancer is nowadays of main interest in research. Positron Emission Tomography (PET) appears to become a reference exam for monitoring treatment of cancers, particular in lymphoma. This PhD thus deals on the development of a computer aided detection (CAD) tool focused on hardly visible tumors for whole-body 3D PET images. To achieve such a goal, we proposed an approach based on the combination of two classifiers, the Linear Discriminant Analysis (LDA) and the Support Vector Machines, associated with wavelet image features. Each classifier gives a 3D score map quantifying the probability of its voxels to correspond to a tumor. We proposed a 3D evaluation strategy based on the use of simulated images giving the targeted tumor characteristic gold standard. Such database was developed in this PhD from hundred Monte Carlo simulations of the Zuba phantom. It includes hundred images presenting 375 spherical tumors of calibrated contrasts. Results of the CAD obtained from the binary detection maps are promising. They open the perspective of enriching the binary information generally given to the clinician with parametric indices quantifying the pertinence of each detected tumor. (author)

  5. GPU based Monte Carlo for PET image reconstruction: parameter optimization

    International Nuclear Information System (INIS)

    This paper presents the optimization of a fully Monte Carlo (MC) based iterative image reconstruction of Positron Emission Tomography (PET) measurements. With our MC re- construction method all the physical effects in a PET system are taken into account thus superior image quality is achieved in exchange for increased computational effort. The method is feasible because we utilize the enormous processing power of Graphical Processing Units (GPUs) to solve the inherently parallel problem of photon transport. The MC approach regards the simulated positron decays as samples in mathematical sums required in the iterative reconstruction algorithm, so to complement the fast architecture, our work of optimization focuses on the number of simulated positron decays required to obtain sufficient image quality. We have achieved significant results in determining the optimal number of samples for arbitrary measurement data, this allows to achieve the best image quality with the least possible computational effort. Based on this research recommendations can be given for effective partitioning of computational effort into the iterations in limited time reconstructions. (author)

  6. State of the art in both in vitro and in vivo aspects of small animal imaging

    International Nuclear Information System (INIS)

    Full text: In vivo imaging for small animals is dramatically expanding due to the coincidence of mainly three technical factors: 1. the explosion in computer power 2. the enhancement in image processing 3. the accessibility and affordability of digital autoradiography systems and small-animal scanners. Among these imaging techniques let us mention the anatomical imaging techniques such as ultrasonography, X-rays and IRM and the functional imaging radioisotopic techniques SPECT and TEP. The main advantage of the first group of imaging techniques is essentially linked to the high resolution of the anatomical images (with the drawback of the necessity of putting the animal at rest using anaesthesia). The main advantages of SPECT and PET are their high sensitivity and the vast number of functions or metabolism they allow to image. The applications for isotopic functional imaging in small animals are increasing rapidly. Factors contributing to this dramatic expansion include the three previous technical factors plus, at least, three methodological factors: 1. the drug discovery process based on receptor / mechanism of action 2. the increasing number of rodent models of human diseases (SCID mice implanted with human tumors, gene knock-out mice, transgene mice) 3. the advances in isotope and validated tracer availability performances Small animal radioisotopic functional imaging for drug development. In vivo quantification of biological processes to measure the mechanism of action of a potential drug and its concentration at the site of action has become mandatory for developing a drug. Rational and efficient means of confirming mechanisms of action are required. For this purpose, PET and/or SPECT functional - biochemical - molecular imaging in small animals are tools of choice for economical reasons (in the domain of drug development, industry is suffering huge opportunity costs by failing to weed out non-performing new active substances until late phases II and III) and

  7. In vivo PET imaging of brain nicotinic cholinergic receptors

    International Nuclear Information System (INIS)

    Neuronal acetylcholine receptors (nAChRs) are widely distributed throughout the central nervous system where they modulate a number of CNS functions including neurotransmitter release, cognitive function, anxiety, analgesia and control of cerebral blood flow. In the brain, a major subtype is composed of the α4β2 subunit combination. Density of this subtype has been shown to be decreased in patients with neuro-degenerative disease such as Alzheimer and Parkinson's disease (AD and PD), and mutated receptors has been described in some familial epilepsy. Thus, in vivo mapping of the nicotinic nAChRs by Positron Emission Tomography (PET) are of great interest to monitor the evolution of these pathologies and changes in the neuronal biochemistry induced by therapeutic agents. Recently, a new compound, 3-[2(S)-2-azetidinyl-methoxy]pyridine (A-85380) has been synthesised and labelled with fluorine-18, [18F]fluoro-A-85380 (Dolle et al., 1999). The [18F]fluoro-A-85380 has been shown to bind with high affinity t o nAChRs in vitro (Saba et al., 2004), and its toxicity was low and compatible with it s use at tracer dose in human PET studies (Valette, 2002). PET studies in baboons showed that, after in vivo administration of [ 18F]fluoro-A-85380 at a tracer dose, the distribution of the radioactivity in the brain reflect the distribution of the 18F]fluoro-A-8538 0 combined with its low toxicity make possible the imaging of the nicotinic receptor s in human by PET (Bottlaender 2003). Studies were performed in healthy non-smoker volunteers to evaluate the brain kinetics of [18F]fluoro-A-85380 and to assess the quantification of its nAChRs binding in the human brain with PET (Gallezot et a., 2005). The [18F]fluoro-A-85380 was also used in epileptic patients to whom a mutation in the α4 or β2 nAChRs subunit have been identified. We found that, in these patients, the pattern of the brain distribution of the radiotracer was found different when compared to the healthy subjects

  8. Imaging results and TOF studies with axial PET detectors

    CERN Document Server

    Joram, Christian

    2013-01-01

    We have developed a fully operational PET demonstrator setup which allows true 3D reconstruction of the 511 keV photons and therefore leads to practically parallax free images. The AX-PET concept is based on thin 100 mm long scintillation crystals (LYSO), axially oriented and arranged in layers around the held of view. Layers of wavelength shifting plastic strips mounted in between the crystal layers give the axial coordinate. Both crystals and WLS strips are individually read out by G-APD (SiPM) photodetectors. The Fully scalable concept overcomes the dilemma of sensitivity versus spatial resolution which is inherent to classical PET designs. A demonstrator set-up based on two axial modules was exhaustively characterized using point-like sources, phantoms filled with radiotracer and finally rats and a mouse. The results entirely meet the performance expectations ( <2 mm FWHM in all three coordinates over the complete held of view) and also demonstrated the ability to include Compton interactions (inter-cr...

  9. Physiological imaging with PET and SPECT in Dementia

    Energy Technology Data Exchange (ETDEWEB)

    Jagust, W.J. (California Univ., San Francisco, CA (United States). Dept. of Neurology Lawrence Berkeley Lab., CA (United States))

    1989-10-01

    Dementia is a medical problem of increasingly obvious importance. The most common cause of dementia, Alzheimer's disease (AD) accounts for at least 50% of all cases of dementia, with multi-infarct dementia the next most common cause of the syndrome. While the accuracy of diagnosis of AD may range from 80 to 90%, there is currently no laboratory test to confirm the diagnosis. Functional imaging techniques such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) offer diagnostic advantages since brain function is unequivocally disturbed in all dementing illnesses. Both PET and SPECT have been utilized in the study of dementia. While both techniques rely on principles of emission tomography to produce three dimensional maps of injected radiotracers, the differences between positron and single photon emission have important consequences for the practical applications of the two procedures. This briefly reviews the technical differences between PET and SPECT, and discusses how both techniques have been used in our laboratory to elucidate the pathophysiology of dementia. 32 refs., 2 figs.

  10. Physiological imaging with PET and SPECT in Dementia

    International Nuclear Information System (INIS)

    Dementia is a medical problem of increasingly obvious importance. The most common cause of dementia, Alzheimer's disease (AD) accounts for at least 50% of all cases of dementia, with multi-infarct dementia the next most common cause of the syndrome. While the accuracy of diagnosis of AD may range from 80 to 90%, there is currently no laboratory test to confirm the diagnosis. Functional imaging techniques such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) offer diagnostic advantages since brain function is unequivocally disturbed in all dementing illnesses. Both PET and SPECT have been utilized in the study of dementia. While both techniques rely on principles of emission tomography to produce three dimensional maps of injected radiotracers, the differences between positron and single photon emission have important consequences for the practical applications of the two procedures. This briefly reviews the technical differences between PET and SPECT, and discusses how both techniques have been used in our laboratory to elucidate the pathophysiology of dementia. 32 refs., 2 figs

  11. Fluorescence-enhanced optical tomography and nuclear imaging system for small animals

    Science.gov (United States)

    Tan, I.-Chih; Lu, Yujie; Darne, Chinmay; Rasmussen, John C.; Zhu, Banghe; Azhdarinia, Ali; Yan, Shikui; Smith, Anne M.; Sevick-Muraca, Eva M.

    2012-03-01

    Near-infrared (NIR) fluorescence is an alternative modality for molecular imaging that has been demonstrated in animals and recently in humans. Fluorescence-enhanced optical tomography (FEOT) using continuous wave or frequency domain photon migration techniques could be used to provide quantitative molecular imaging in vivo if it could be validated against "gold-standard," nuclear imaging modalities, using dual-labeled imaging agents. Unfortunately, developed FEOT systems are not suitable for incorporation with CT/PET/SPECT scanners because they utilize benchtop devices and require a large footprint. In this work, we developed a miniaturized fluorescence imaging system installed in the gantry of the Siemens Inveon PET/CT scanner to enable NIR transillumination measurements. The system consists of a CCD camera equipped with NIR sensitive intensifier, a diode laser controlled by a single board compact controller, a 2-axis galvanometer, and RF circuit modules for homodyne detection of the phase and amplitude of fluorescence signals. The performance of the FEOT system was tested and characterized. A mouse-shaped solid phantom of uniform optical properties with a fluorescent inclusion was scanned using CT, and NIR fluorescence images at several projections were collected. The method of high-order approximation to the radioactive transfer equation was then used to reconstruct the optical images. Dual-labeled agents were also used on a tumor bearing mouse to validate the results of the FEOT against PET/CT image. The results showed that the location of the fluorophore obtained from the FEOT matches the location of tumor obtained from the PET/CT images. Besides validation of FEOT, this hybrid system could allow multimodal molecular imaging (FEOT/PET/CT) for small animal imaging.

  12. Clinical PET-MR Imaging in Breast Cancer and Lung Cancer.

    Science.gov (United States)

    Rice, Samuel L; Friedman, Kent P

    2016-10-01

    Hybrid imaging systems have dramatically improved thoracic oncology patient care over the past 2 decades. PET-MR imaging systems have the potential to further improve imaging of thoracic neoplasms, resulting in diagnostic and therapeutic advantages compared with current MR imaging and PET-computed tomography systems. Increasing soft tissue contrast and lesion sensitivity, improved image registration, reduced radiation exposure, and improved patient convenience are immediate clinical advantages. Multiparametric quantitative imaging capabilities of PET-MR imaging have the potential to improve understanding of the molecular mechanisms of cancer and treatment effects, potentially guiding improvements in diagnosis and therapy. PMID:27593245

  13. Combined Micro-PET/Micro-CT Imaging of Lung Tumours in SPC-raf and SPC-myc Transgenic Mice

    Science.gov (United States)

    Rodt, Thomas; Luepke, Matthias; Boehm, Claudia; Hueper, Katja; Halter, Roman; Glage, Silke; Hoy, Ludwig; Wacker, Frank; Borlak, Juergen; von Falck, Christian

    2012-01-01

    Introduction SPC-raf and SPC-myc transgenic mice develop disseminated and circumscribed lung adenocarcinoma respectively, allowing for assessment of carcinogenesis and treatment strategies. The purpose of this study was to investigate the technical feasibility, the correlation of initial findings to histology and the administered radiation dose of combined micro-PET/micro-CT in these animal models. Material and Methods 14 C57BL/6 mice (4 nontransgenic, 4 SPC-raf transgenic, 6 SPC-myc transgenic) were examined using micro-CT and 18F-Fluoro-deoxyglucose micro-PET in-vivo. Micro-PET data was corrected for random events and scatter prior to reconstruction with a 3D-FORE/2D-OSEM iterative algorithm. Rigid micro-PET/micro-CT registration was performed. Tumour-to-non-tumour ratios were calculated for different lung regions and focal lesions. Diffuse tumour growth was quantified using a semiautomated micro-CT segmentation routine reported earlier. Regional histologic tumour load was assessed using a 4-point rating scale. Gamma radiation dose was determined using thermoluminescence dosimeters. Results Micro-CT allowed visualisation of diffuse and circumscribed tumours in SPC-raf and SPC-myc transgenic animals along with morphology, while micro-PET provided information on metabolism, but lacked morphologic detail. Mean tumour-to-non-tumour ratio was 2.47 for circumscribed lesions. No significant correlation could be shown between histological tumour load and tumour-to-nontumour ratio for diffuse tumours in SPC-raf transgenic animals. Calculation of the expected dose based on gamma dosimetry yielded approximately 140 mGy/micro-PET examination additional to approximately 200 mGy due to micro-CT. Conclusions Combined micro-PET/micro-CT imaging allows for in-vivo assessment of lung tumours in SPC-raf and SPC-myc transgenic mice. The technique has potential for the evaluation of carcinogenesis and treatment strategies in circumscribed lung tumours. PMID:23028537

  14. Combined micro-PET/micro-CT imaging of lung tumours in SPC-raf and SPC-myc transgenic mice.

    Directory of Open Access Journals (Sweden)

    Thomas Rodt

    Full Text Available INTRODUCTION: SPC-raf and SPC-myc transgenic mice develop disseminated and circumscribed lung adenocarcinoma respectively, allowing for assessment of carcinogenesis and treatment strategies. The purpose of this study was to investigate the technical feasibility, the correlation of initial findings to histology and the administered radiation dose of combined micro-PET/micro-CT in these animal models. MATERIAL AND METHODS: 14 C57BL/6 mice (4 nontransgenic, 4 SPC-raf transgenic, 6 SPC-myc transgenic were examined using micro-CT and (18F-Fluoro-deoxyglucose micro-PET in-vivo. Micro-PET data was corrected for random events and scatter prior to reconstruction with a 3D-FORE/2D-OSEM iterative algorithm. Rigid micro-PET/micro-CT registration was performed. Tumour-to-non-tumour ratios were calculated for different lung regions and focal lesions. Diffuse tumour growth was quantified using a semiautomated micro-CT segmentation routine reported earlier. Regional histologic tumour load was assessed using a 4-point rating scale. Gamma radiation dose was determined using thermoluminescence dosimeters. RESULTS: Micro-CT allowed visualisation of diffuse and circumscribed tumours in SPC-raf and SPC-myc transgenic animals along with morphology, while micro-PET provided information on metabolism, but lacked morphologic detail. Mean tumour-to-non-tumour ratio was 2.47 for circumscribed lesions. No significant correlation could be shown between histological tumour load and tumour-to-nontumour ratio for diffuse tumours in SPC-raf transgenic animals. Calculation of the expected dose based on gamma dosimetry yielded approximately 140 mGy/micro-PET examination additional to approximately 200 mGy due to micro-CT. CONCLUSIONS: Combined micro-PET/micro-CT imaging allows for in-vivo assessment of lung tumours in SPC-raf and SPC-myc transgenic mice. The technique has potential for the evaluation of carcinogenesis and treatment strategies in circumscribed lung tumours.

  15. Molecular imaging of gene expression and protein function in vivo with PET and SPECT.

    Science.gov (United States)

    Sharma, Vijay; Luker, Gary D; Piwnica-Worms, David

    2002-10-01

    Molecular imaging is broadly defined as the characterization and measurement of biological processes in living animals, model systems, and humans at the cellular and molecular level using remote imaging detectors. One underlying premise of molecular imaging is that this emerging field is not defined by the imaging technologies that underpin acquisition of the final image per se, but rather is driven by the underlying biological questions. In practice, the choice of imaging modality and probe is usually reduced to choosing between high spatial resolution and high sensitivity to address a given biological system. Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) inherently use image-enhancing agents (radiopharmaceuticals) that are synthesized at sufficiently high specific activity to enable use of tracer concentrations of the compound (picomolar to nanomolar) for detecting molecular signals while providing the desired levels of image contrast. The tracer technologies strategically provide high sensitivity for imaging small-capacity molecular systems in vivo (receptors, enzymes, transporters) at a cost of lower spatial resolution than other technologies. We review several significant PET and SPECT advances in imaging receptors (somatostatin receptor subtypes, neurotensin receptor subtypes, alpha(v)beta(3) integrin), enzymes (hexokinase, thymidine kinase), transporters (MDR1 P-glycoprotein, sodium-iodide symporter), and permeation peptides (human immunodeficiency virus type 1 (HIV-1) Tat conjugates), as well as innovative reporter gene constructs (herpes simplex virus 1 thymidine kinase, somatostatin receptor subtype 2, cytosine deaminase) for imaging gene promoter activation and repression, signal transduction pathways, and protein-protein interactions in vivo. PMID:12353250

  16. 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.  ...

  17. Feasibility of using respiration-averaged MR images for attenuation correction of cardiac PET/MR imaging.

    Science.gov (United States)

    Ai, Hua; Pan, Tinsu

    2015-01-01

    Cardiac imaging is a promising application for combined PET/MR imaging. However, current MR imaging protocols for whole-body attenuation correction can produce spatial mismatch between PET and MR-derived attenuation data owing to a disparity between the two modalities' imaging speeds. We assessed the feasibility of using a respiration-averaged MR (AMR) method for attenuation correction of cardiac PET data in PET/MR images. First, to demonstrate the feasibility of motion imaging with MR, we used a 3T MR system and a two-dimensional fast spoiled gradient-recalled echo (SPGR) sequence to obtain AMR images ofa moving phantom. Then, we used the same sequence to obtain AMR images of a patient's thorax under free-breathing conditions. MR images were converted into PET attenuation maps using a three-class tissue segmentation method with two sets of predetermined CT numbers, one calculated from the patient-specific (PS) CT images and the other from a reference group (RG) containing 54 patient CT datasets. The MR-derived attenuation images were then used for attenuation correction of the cardiac PET data, which were compared to the PET data corrected with average CT (ACT) images. In the myocardium, the voxel-by-voxel differences and the differences in mean slice activity between the AMR-corrected PET data and the ACT-corrected PET data were found to be small (less than 7%). The use of AMR-derived attenuation images in place of ACT images for attenuation correction did not affect the summed stress score. These results demonstrate the feasibility of using the proposed SPGR-based MR imaging protocol to obtain patient AMR images and using those images for cardiac PET attenuation correction. Additional studies with more clinical data are warranted to further evaluate the method. PMID:26218995

  18. Molecular imaging of cancer with radiolabeled peptides and PET.

    Science.gov (United States)

    Vāvere, Amy L; Rossin, Raffaella

    2012-06-01

    Radiolabeled peptides hold promise for diagnosis and therapy of cancer as well as for early monitoring of therapy outcomes, patient stratification, etc. This manuscript focuses on the development of peptides labeled with 18F, 64Cu, 68Ga and other positron-emitting radionuclides for PET imaging. The major techniques for radionuclide incorporation are briefly discussed. Then, examples of positron-emitting peptides targeting somatostatin receptors, integrins, gastrin-releasing peptide receptors, vasointestinal peptide receptors, melanocortin 1 receptors and others are reviewed. PMID:22292762

  19. Noise and physical limits to maximum resolution of PET images

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J.L.; Espana, S. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain); Vicente, E.; Vaquero, J.J.; Desco, M. [Unidad de Medicina y Cirugia Experimental, Hospital GU ' Gregorio Maranon' , E-28007 Madrid (Spain); Udias, J.M. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain)], E-mail: jose@nuc2.fis.ucm.es

    2007-10-01

    In this work we show that there is a limit for the maximum resolution achievable with a high resolution PET scanner, as well as for the best signal-to-noise ratio, which are ultimately related to the physical effects involved in the emission and detection of the radiation and thus they cannot be overcome with any particular reconstruction method. These effects prevent the spatial high frequency components of the imaged structures to be recorded by the scanner. Therefore, the information encoded in these high frequencies cannot be recovered by any reconstruction technique. Within this framework, we have determined the maximum resolution achievable for a given acquisition as a function of data statistics and scanner parameters, like the size of the crystals or the inter-crystal scatter. In particular, the noise level in the data as a limitation factor to yield high-resolution images in tomographs with small crystal sizes is outlined. These results have implications regarding how to decide the optimal number of voxels of the reconstructed image or how to design better PET scanners.

  20. PET/CT Imaging and Radioimmunotherapy of Prostate Cancer

    DEFF Research Database (Denmark)

    Bouchelouche, Kirsten; Tagawa, Scott T; Goldsmith, Stanley J;

    2011-01-01

    of more effective treatment modalities that could improve outcome. Prostate cancer represents an attractive target for radioimmunotherapy (RIT) for several reasons, including pattern of metastatic spread (lymph nodes and bone marrow, sites with good access to circulating antibodies) and small volume...... antitumor activity and is well tolerated. Clinical trials are underway to further improve upon treatment efficacy and patient selection. This review focuses on the recent advances of clinical PET/CT imaging and RIT of prostate cancer.......Prostate cancer is a common cancer in men and continues to be a major health problem. Imaging plays an important role in the clinical management of patients with prostate cancer. An important goal for prostate cancer imaging is more accurate disease characterization through the synthesis...

  1. Pediatric oncologic imaging. A key application of combined PET/MRI

    Energy Technology Data Exchange (ETDEWEB)

    Gatidis, Sergios; La Fougere, C.; Schaefer, J.F. [Universitaetsklinikum Tuebingen (Germany). Abteilung fuer Diagnostische und Interventionelle Radiologie

    2016-04-15

    Pediatric imaging has been identified as a key application of combined whole-body PET/MRI. First studies have revealed the clinical feasibility and possible advantages of PET/MRI over PET/CT and MRI. Besides a significant reduction in radiation exposure of about 50 - 75 %, combined whole-body PET/MRI offers the diagnostic advantage of the multiparametric characterization of pathophysiologic processes and helps reduce the number of necessary imaging studies. However, very few studies focusing on pediatric PET/MRI have been published to date. Additional studies are necessary in order to fully appreciate the clinical impact of this novel method. This review article shall summarize the existing literature concerning pediatric PET/MRI and give insight into the practical experience derived from over 160 pediatric PET/MRI examinations that were performed in Tuebingen.

  2. FDG-PET/CT imaging for staging and radiotherapy treatment planning of head and neck carcinoma

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) has a potential improvement for staging and radiation treatment planning of various tumor sites. We analyzed the use of 18F-fluorodeoxyglucose (FDG)-PET/computed tomography (CT) images for staging and target volume delineation of patients with head and neck carcinoma candidates for radiotherapy. Twenty-two patients candidates for primary radiotherapy, who did not receive any curative surgery, underwent both CT and PET/CT simulation. Gross Tumor Volume (GTV) was contoured on CT (CT-GTV), PET (PET-GTV), and PET/CT images (PET/CT-GTV). The resulting volumes were analyzed and compared. Based on PET/CT, changes in TNM categories and clinical stage occurred in 5/22 cases (22%). The difference between CT-GTV and PET-GTV was not statistically significant (p = 0.2) whereas the difference between the composite volume (PET/CT-GTV) and CT-GTV was statistically significant (p < 0.0001). PET/CT fusion images could have a potential impact on both tumor staging and treatment planning

  3. MO-G-17A-01: Innovative High-Performance PET Imaging System for Preclinical Imaging and Translational Researches

    Energy Technology Data Exchange (ETDEWEB)

    Sun, X [University of Texas MD Anderson Cancer Center, Houston, TX (United States); Lou, K [University of Texas MD Anderson Cancer Center, Houston, TX (United States); Rice University, Houston, TX (United States); Deng, Z [Tsinghua University, Beijing (China); Shao, Y

    2014-06-15

    Purpose: To develop a practical and compact preclinical PET with innovative technologies for substantially improved imaging performance required for the advanced imaging applications. Methods: Several key components of detector, readout electronics and data acquisition have been developed and evaluated for achieving leapfrogged imaging performance over a prototype animal PET we had developed. The new detector module consists of an 8×8 array of 1.5×1.5×30 mm{sup 3} LYSO scintillators with each end coupled to a latest 4×4 array of 3×3 mm{sup 2} Silicon Photomultipliers (with ∼0.2 mm insensitive gap between pixels) through a 2.0 mm thick transparent light spreader. Scintillator surface and reflector/coupling were designed and fabricated to reserve air-gap to achieve higher depth-of-interaction (DOI) resolution and other detector performance. Front-end readout electronics with upgraded 16-ch ASIC was newly developed and tested, so as the compact and high density FPGA based data acquisition and transfer system targeting 10M/s coincidence counting rate with low power consumption. The new detector module performance of energy, timing and DOI resolutions with the data acquisition system were evaluated. Initial Na-22 point source image was acquired with 2 rotating detectors to assess the system imaging capability. Results: No insensitive gaps at the detector edge and thus it is capable for tiling to a large-scale detector panel. All 64 crystals inside the detector were clearly separated from a flood-source image. Measured energy, timing, and DOI resolutions are around 17%, 2.7 ns and 1.96 mm (mean value). Point source image is acquired successfully without detector/electronics calibration and data correction. Conclusion: Newly developed advanced detector and readout electronics will be enable achieving targeted scalable and compact PET system in stationary configuration with >15% sensitivity, ∼1.3 mm uniform imaging resolution, and fast acquisition counting rate

  4. MO-G-17A-01: Innovative High-Performance PET Imaging System for Preclinical Imaging and Translational Researches

    International Nuclear Information System (INIS)

    Purpose: To develop a practical and compact preclinical PET with innovative technologies for substantially improved imaging performance required for the advanced imaging applications. Methods: Several key components of detector, readout electronics and data acquisition have been developed and evaluated for achieving leapfrogged imaging performance over a prototype animal PET we had developed. The new detector module consists of an 8×8 array of 1.5×1.5×30 mm3 LYSO scintillators with each end coupled to a latest 4×4 array of 3×3 mm2 Silicon Photomultipliers (with ∼0.2 mm insensitive gap between pixels) through a 2.0 mm thick transparent light spreader. Scintillator surface and reflector/coupling were designed and fabricated to reserve air-gap to achieve higher depth-of-interaction (DOI) resolution and other detector performance. Front-end readout electronics with upgraded 16-ch ASIC was newly developed and tested, so as the compact and high density FPGA based data acquisition and transfer system targeting 10M/s coincidence counting rate with low power consumption. The new detector module performance of energy, timing and DOI resolutions with the data acquisition system were evaluated. Initial Na-22 point source image was acquired with 2 rotating detectors to assess the system imaging capability. Results: No insensitive gaps at the detector edge and thus it is capable for tiling to a large-scale detector panel. All 64 crystals inside the detector were clearly separated from a flood-source image. Measured energy, timing, and DOI resolutions are around 17%, 2.7 ns and 1.96 mm (mean value). Point source image is acquired successfully without detector/electronics calibration and data correction. Conclusion: Newly developed advanced detector and readout electronics will be enable achieving targeted scalable and compact PET system in stationary configuration with >15% sensitivity, ∼1.3 mm uniform imaging resolution, and fast acquisition counting rate capability for

  5. Registered error between PET and CT images confirmed by a water model

    International Nuclear Information System (INIS)

    The registered error between PET and CT imaging system was confirmed by a water model simulating clinical cases. A barrel of 6750 mL was filled with 59.2 MBq [18F]-FDG and scanned after 80 min by 2 dimension model PET/CT. The CT images were used to attenuate the PET images. The CT/PET images were obtained by image morphological processing analyses without barrel wall. The relationship of the water image centroids of CT and PET images was established by linear regression analysis, and the registered error between PET and CT image could be computed one slice by one slice. The alignment program was done 4 times following the protocol given by GE Healthcare. Compared with centroids of water CT images, centroids of PET images were shifted to X-axis (0.011slice+0.63) mm, to Y-axis (0.022×slice+1.35) mm. To match CT images, PET images should be translated along X-axis (-2.69±0.15) mm, Y-axis (0.43±0.11) mm, Z-axis (0.86±0.23) mm, and X-axis be rotated by (0.06±0.07)°, Y-axis by (-0.01±0.08)°, and Z-axis by (0.11±0.07)°. So, the systematic registered error was not affected by load and its distribution. By finding the registered error between PET and CT images for coordinate rotation random error, the water model could confirm the registered results of PET-CT system corrected by Alignment parameters. (authors)

  6. FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0

    DEFF Research Database (Denmark)

    Boellaard, Ronald; O'Doherty, Mike J; Weber, Wolfgang A;

    2010-01-01

    The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about[18F]-fluorodeoxyglucose (FDG) positron emission tomography......-computed tomography (PET/CT) and is provided to help the physician and physicist to assist to carrying out,interpret, and document quantitative FDG PET/CT examinations,but will concentrate on the optimisation of diagnostic quality and quantitative information....

  7. Attenuation correction of emission PET images with average CT: Interpolation from breath-hold CT

    International Nuclear Information System (INIS)

    Misregistration resulting from the difference of temporal resolution in PET and CT scans occur frequently in PET/CT imaging, which causes distortion in tumor quantification in PET. Respiration cine average CT (CACT) for PET attenuation correction has been reported to improve the misalignment effectively by several papers. However, the radiation dose to the patient from a four-dimensional CT scan is relatively high. In this study, we propose a method to interpolate respiratory CT images over a respiratory cycle from inhalation and exhalation breath-hold CT images, and use the average CT from the generated CT set for PET attenuation correction. The radiation dose to the patient is reduced using this method. Six cancer patients of various lesion sites underwent routine free-breath helical CT (HCT), respiration CACT, interpolated average CT (IACT), and 18F-FDG PET. Deformable image registration was used to interpolate the middle phases of a respiratory cycle based on the end-inspiration and end-expiration breath-hold CT scans. The average CT image was calculated from the eight interpolated CT image sets of middle respiratory phases and the two original inspiration and expiration CT images. Then the PET images were reconstructed by these three methods for attenuation correction using HCT, CACT, and IACT. Misalignment of PET image using either CACT or IACT for attenuation correction in PET/CT was improved. The difference in standard uptake value (SUV) from tumor in PET images was most significant between the use of HCT and CACT, while the least significant between the use of CACT and IACT. Besides the similar improvement in tumor quantification compared to the use of CACT, using IACT for PET attenuation correction reduces the radiation dose to the patient.

  8. Attenuation correction of emission PET images with average CT: Interpolation from breath-hold CT

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Tzung-Chi [Department of Biomedical Imaging and Radiological Science, China Medical University, Taiwan (China); Zhang, Geoffrey [Department of Radiation Oncology, Moffitt Cancer Center, FL (United States); Chen, Chih-Hao [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Yang, Bang-Hung [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Wu, Nien-Yun [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Wang, Shyh-Jen, E-mail: jwshyh@vghtpe.gov.tw [Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China); Wu, Tung-Hsin, E-mail: tung@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taiwan (China)

    2011-05-15

    Misregistration resulting from the difference of temporal resolution in PET and CT scans occur frequently in PET/CT imaging, which causes distortion in tumor quantification in PET. Respiration cine average CT (CACT) for PET attenuation correction has been reported to improve the misalignment effectively by several papers. However, the radiation dose to the patient from a four-dimensional CT scan is relatively high. In this study, we propose a method to interpolate respiratory CT images over a respiratory cycle from inhalation and exhalation breath-hold CT images, and use the average CT from the generated CT set for PET attenuation correction. The radiation dose to the patient is reduced using this method. Six cancer patients of various lesion sites underwent routine free-breath helical CT (HCT), respiration CACT, interpolated average CT (IACT), and 18F-FDG PET. Deformable image registration was used to interpolate the middle phases of a respiratory cycle based on the end-inspiration and end-expiration breath-hold CT scans. The average CT image was calculated from the eight interpolated CT image sets of middle respiratory phases and the two original inspiration and expiration CT images. Then the PET images were reconstructed by these three methods for attenuation correction using HCT, CACT, and IACT. Misalignment of PET image using either CACT or IACT for attenuation correction in PET/CT was improved. The difference in standard uptake value (SUV) from tumor in PET images was most significant between the use of HCT and CACT, while the least significant between the use of CACT and IACT. Besides the similar improvement in tumor quantification compared to the use of CACT, using IACT for PET attenuation correction reduces the radiation dose to the patient.

  9. Attenuation correction of emission PET images with average CT: Interpolation from breath-hold CT

    Science.gov (United States)

    Huang, Tzung-Chi; Zhang, Geoffrey; Chen, Chih-Hao; Yang, Bang-Hung; Wu, Nien-Yun; Wang, Shyh-Jen; Wu, Tung-Hsin

    2011-05-01

    Misregistration resulting from the difference of temporal resolution in PET and CT scans occur frequently in PET/CT imaging, which causes distortion in tumor quantification in PET. Respiration cine average CT (CACT) for PET attenuation correction has been reported to improve the misalignment effectively by several papers. However, the radiation dose to the patient from a four-dimensional CT scan is relatively high. In this study, we propose a method to interpolate respiratory CT images over a respiratory cycle from inhalation and exhalation breath-hold CT images, and use the average CT from the generated CT set for PET attenuation correction. The radiation dose to the patient is reduced using this method. Six cancer patients of various lesion sites underwent routine free-breath helical CT (HCT), respiration CACT, interpolated average CT (IACT), and 18F-FDG PET. Deformable image registration was used to interpolate the middle phases of a respiratory cycle based on the end-inspiration and end-expiration breath-hold CT scans. The average CT image was calculated from the eight interpolated CT image sets of middle respiratory phases and the two original inspiration and expiration CT images. Then the PET images were reconstructed by these three methods for attenuation correction using HCT, CACT, and IACT. Misalignment of PET image using either CACT or IACT for attenuation correction in PET/CT was improved. The difference in standard uptake value (SUV) from tumor in PET images was most significant between the use of HCT and CACT, while the least significant between the use of CACT and IACT. Besides the similar improvement in tumor quantification compared to the use of CACT, using IACT for PET attenuation correction reduces the radiation dose to the patient.

  10. PET imaging reveals brain functional changes in internet gaming disorder

    International Nuclear Information System (INIS)

    Internet gaming disorder is an increasing problem worldwide, resulting in critical academic, social, and occupational impairment. However, the neurobiological mechanism of internet gaming disorder remains unknown. The aim of this study is to assess brain dopamine D2 (D2)/Serotonin 2A (5-HT2A) receptor function and glucose metabolism in the same subjects by positron emission tomography (PET) imaging approach, and investigate whether the correlation exists between D2 receptor and glucose metabolism. Twelve drug-naive adult males who met criteria for internet gaming disorder and 14 matched controls were studied with PET and 11C-N-methylspiperone (11C-NMSP) to assess the availability of D2/5-HT2A receptors and with 18F-fluoro-D-glucose (18F-FDG) to assess regional brain glucose metabolism, a marker of brain function. 11C-NMSP and 18F-FDG PET imaging data were acquired in the same individuals under both resting and internet gaming task states. In internet gaming disorder subjects, a significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems. Dysregulation of D2 receptors was observed in the striatum, and was correlated to years of overuse. A low level of D2 receptors in the striatum was significantly associated with decreased glucose metabolism in the orbitofrontal cortex. For the first time, we report the evidence that D2 receptor level is significantly associated with glucose metabolism in the same individuals with internet gaming disorder, which indicates that D2/5-HT2A receptor-mediated dysregulation of the orbitofrontal cortex could underlie a mechanism for loss of control and compulsive behavior in internet gaming disorder subjects. (orig.)

  11. PET imaging reveals brain functional changes in internet gaming disorder

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Mei; Zhang, Ying; Du, Fenglei; Hou, Haifeng; Chao, Fangfang; Zhang, Hong [The Second Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou (China); Chen, Qiaozhen [The Second Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); The Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Psychiatry, Hangzhou (China)

    2014-07-15

    Internet gaming disorder is an increasing problem worldwide, resulting in critical academic, social, and occupational impairment. However, the neurobiological mechanism of internet gaming disorder remains unknown. The aim of this study is to assess brain dopamine D{sub 2} (D{sub 2})/Serotonin 2A (5-HT{sub 2A}) receptor function and glucose metabolism in the same subjects by positron emission tomography (PET) imaging approach, and investigate whether the correlation exists between D{sub 2} receptor and glucose metabolism. Twelve drug-naive adult males who met criteria for internet gaming disorder and 14 matched controls were studied with PET and {sup 11}C-N-methylspiperone ({sup 11}C-NMSP) to assess the availability of D{sub 2}/5-HT{sub 2A} receptors and with {sup 18}F-fluoro-D-glucose ({sup 18}F-FDG) to assess regional brain glucose metabolism, a marker of brain function. {sup 11}C-NMSP and {sup 18}F-FDG PET imaging data were acquired in the same individuals under both resting and internet gaming task states. In internet gaming disorder subjects, a significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems. Dysregulation of D{sub 2} receptors was observed in the striatum, and was correlated to years of overuse. A low level of D{sub 2} receptors in the striatum was significantly associated with decreased glucose metabolism in the orbitofrontal cortex. For the first time, we report the evidence that D{sub 2} receptor level is significantly associated with glucose metabolism in the same individuals with internet gaming disorder, which indicates that D{sub 2}/5-HT{sub 2A} receptor-mediated dysregulation of the orbitofrontal cortex could underlie a mechanism for loss of control and compulsive behavior in internet gaming disorder subjects. (orig.)

  12. Clinical PET/CT Atlas: A Casebook of Imaging in Oncology

    International Nuclear Information System (INIS)

    Integrated positron emission tomography/computed tomography (PET/CT) has evolved since its introduction into the commercial market more than a decade ago. It is now a key procedure, particularly in oncological imaging. Over the last years in routine clinical service, PET/CT has had a significant impact on diagnosis, treatment planning, staging, therapy, and monitoring of treatment response and has therefore played an important role in the care of cancer patients. The high sensitivity from the PET component and the specificity of the CT component give this hybrid imaging modality the unique characteristics that make PET/CT, even after over 10 years of clinical use, one of the fastest growing imaging modalities worldwide. This publication combines over 90 comprehensive cases covering all major indications of fluorodeoxyglucose (18F-FDG)-PET/CT as well as some cases of clinically relevant special tracers. The cases provide an overview of what the specific disease can look like in PET/CT, the typical pattern of the disease’s spread as well as likely pitfalls and teaching points. This PET/CT Atlas will allow professionals interested in PET/CT imaging to embrace the variety of oncological imaging by providing clinically relevant teaching files on the effectiveness and diagnostic quality of FDG-PET/CT imaging in routine applications

  13. The labelling and animal study of tumor positive imaging agent 5-18F-fluorouracil

    International Nuclear Information System (INIS)

    Objective: To synthesize and label a tumor positive imaging agent 18F-fluorouracil (FU) and the animal study on the product was also undertaken. Methods: 18F-FU was synthesized and labelled. Its biodistribution analysis was done on normal and tumor bearing nude mice. PET imaging was performed on normal and tumor bearing rabbits. Results: HPLC analysis and other quality control test results guaranteed the possibility of animal study and clinical usage of 18F-FU. Biodistribution analysis and PET imaging also demonstrated a high accumulation of the tracer in tumor tissue. Conclusion: 18F-FU is a kind of potential tumor positive imaging agents which can be used to assess the effects of chemotherapy

  14. ICA based automatic segmentation of dynamic H(2)(15)O cardiac PET images.

    Science.gov (United States)

    Margadán-Méndez, Margarita; Juslin, Anu; Nesterov, Sergey V; Kalliokoski, Kari; Knuuti, Juhani; Ruotsalainen, Ulla

    2010-05-01

    In this study, we applied an iterative independent component analysis (ICA) method for the separation of cardiac tissue components (myocardium, right, and left ventricle) from dynamic positron emission tomography (PET) images. Previous phantom and animal studies have shown that ICA separation extracts the cardiac structures accurately. Our goal in this study was to investigate the methodology with human studies. The ICA separated cardiac structures were used to calculate the myocardial perfusion in two different cases: 1) the regions of interest were drawn manually on the ICA separated component images and 2) the volumes of interest (VOI) were automatically segmented from the component images. For the whole myocardium, the perfusion values of 25 rest and six drug-induced stress studies obtained with these methods were compared to the values from the manually drawn regions of interest on differential images. The separation of the rest and stress studies using ICA-based methods was successful in all cases. The visualization of the cardiac structures from H (2) (15) O PET studies was improved with the ICA separation. Also, the automatic segmentation of the VOI seemed to be feasible. PMID:19273031

  15. Simultaneous scanning of two mice in a small-animal PET scanner: a simulation-based assessment of the signal degradation

    Science.gov (United States)

    Reilhac, Anthonin; Boisson, Frédéric; Wimberley, Catriona; Parmar, Arvind; Zahra, David; Hamze, Hasar; Davis, Emma; Arthur, Andrew; Bouillot, Caroline; Charil, Arnaud; Grégoire, Marie-Claude

    2016-02-01

    In PET imaging, research groups have recently proposed different experimental set ups allowing multiple animals to be simultaneously imaged in a scanner in order to reduce the costs and increase the throughput. In those studies, the technical feasibility was demonstrated and the signal degradation caused by additional mice in the FOV characterized, however, the impact of the signal degradation on the outcome of a PET study has not yet been studied. Here we thoroughly investigated, using Monte Carlo simulated [18F]FDG and [11C]Raclopride PET studies, different experimental designs for whole-body and brain acquisitions of two mice and assessed the actual impact on the detection of biological variations as compared to a single-mouse setting. First, we extended the validation of the PET-SORTEO Monte Carlo simulation platform for the simultaneous simulation of two animals. Then, we designed [18F]FDG and [11C]Raclopride input mouse models for the simulation of realistic whole-body and brain PET studies. Simulated studies allowed us to accurately estimate the differences in detection between single- and dual-mode acquisition settings that are purely the result of having two animals in the FOV. Validation results showed that PET-SORTEO accurately reproduced the spatial resolution and noise degradations that were observed with actual dual phantom experiments. The simulated [18F]FDG whole-body study showed that the resolution loss due to the off-center positioning of the mice was the biggest contributing factor in signal degradation at the pixel level and a minimal inter-animal distance as well as the use of reconstruction methods with resolution modeling should be preferred. Dual mode acquisition did not have a major impact on ROI-based analysis except in situations where uptake values in organs from the same subject were compared. The simulated [11C]Raclopride study however showed that dual-mice imaging strongly reduced the sensitivity to variations when mice were

  16. PET imaging predicts future body weight and cocaine preference

    International Nuclear Information System (INIS)

    Deficits in dopamine D2/D3 receptor (D2R/D3R) binding availability using PET imaging have been reported in obese humans and rodents. Similar deficits have been reported in cocaine-addicts and cocaine-exposed primates. We found that D2R/D3R binding availability negatively correlated with measures of body weight at the time of scan (ventral striatum), at 1 (ventral striatum) and 2 months (dorsal and ventral striatum) post scan in rats. Cocaine preference was negatively correlated with D2R/D3R binding availability 2 months (ventral striatum) post scan. Our findings suggest that inherent deficits in striatal D2R/D3R signaling are related to obesity and drug addiction susceptibility and that ventral and dorsal striatum serve dissociable roles in maintaining weight gain and cocaine preference. Measuring D2R/D3R binding availability provides a way for assessing susceptibility to weight gain and cocaine abuse in rodents and given the translational nature of PET imaging, potentially primates and humans.

  17. Recent advances in PET imaging for evaluation of Parkinson's disease.

    Science.gov (United States)

    Sioka, Chrissa; Fotopoulos, Andreas; Kyritsis, Athanassios P

    2010-08-01

    Parkinson's disease (PD) consists of loss of pigmented dopamine-secreting neurons in the pars compacta of the midbrain substantia nigra. These neurons project to the striatum (putamen and caudate nucleus) and their loss leads to alterations in the activity of the neural circuits that regulate movement. In a simplified model, two dopamine pathways are involved: the direct pathway, which is mediated through facilitation of the D(1) receptors, and the indirect pathway through D(2) receptors (inhibitory). Positron emission tomography (PET) tracers to image the presynaptic sites of the dopaminergic system include 6-[(18)F]FDOPA and 6-[(18)F]FMT, [(11)C]dihydrotetrabenazine, [(11)C]nomifensine and various radiolabelled cocaine derivatives. Postsynaptically, for the dopamine D(1) subtype the most commonly used ligands are [(11)C]SCH 23390 or [(11)C]NNC 112 and for the D(2) subtype [(11)C]raclopride, [(11)C]MNPA and [(18)F]DMFP. PET is a sensitive and specific non-invasive molecular imaging technique that may be helpful for evaluation of PD and its differential diagnosis from other parkinsonian syndromes. PMID:20107789

  18. PET imaging predicts future body weight and cocaine preference

    Energy Technology Data Exchange (ETDEWEB)

    Michaelides M.; Wang G.; Michaelides M.; Thanos P.K. Kim R.; Cho J.; Ananth M.; Wang G.-J.; Volkow N.D.

    2011-08-28

    Deficits in dopamine D2/D3 receptor (D2R/D3R) binding availability using PET imaging have been reported in obese humans and rodents. Similar deficits have been reported in cocaine-addicts and cocaine-exposed primates. We found that D2R/D3R binding availability negatively correlated with measures of body weight at the time of scan (ventral striatum), at 1 (ventral striatum) and 2 months (dorsal and ventral striatum) post scan in rats. Cocaine preference was negatively correlated with D2R/D3R binding availability 2 months (ventral striatum) post scan. Our findings suggest that inherent deficits in striatal D2R/D3R signaling are related to obesity and drug addiction susceptibility and that ventral and dorsal striatum serve dissociable roles in maintaining weight gain and cocaine preference. Measuring D2R/D3R binding availability provides a way for assessing susceptibility to weight gain and cocaine abuse in rodents and given the translational nature of PET imaging, potentially primates and humans.

  19. FDG PET/CT : EANM procedure guidelines for tumour imaging: version 2.0

    NARCIS (Netherlands)

    Boellaard, Ronald; Delgado-Bolton, Roberto; Oyen, Wim J. G.; Giammarile, Francesco; Tatsch, Klaus; Eschner, Wolfgang; Verzijlbergen, Fred J.; Barrington, Sally F.; Pike, Lucy C.; Weber, Wolfgang A.; Stroobants, Sigrid; Delbeke, Dominique; Donohoe, Kevin J.; Holbrook, Scott; Graham, Michael M.; Testanera, Giorgio; Hoekstra, Otto S.; Zijlstra, Josee; Visser, Eric; Hoekstra, Corneline J.; Pruim, Jan; Willemsen, Antoon; Arends, Bertjan; Kotzerke, Joerg; Bockisch, Andreas; Beyer, Thomas; Chiti, Arturo; Krause, Bernd J.

    2015-01-01

    The purpose of these guidelines is to assist physicians in recommending, performing, interpreting and reporting the results of FDG PET/CT for oncological imaging of adult patients. PET is a quantitative imaging technique and therefore requires a common quality control (QC)/quality assurance (QA) pro

  20. Ultrasound and PET-CT image fusion for prostate brachytherapy image guidance

    International Nuclear Information System (INIS)

    Fusion of medical images between different cross-sectional modalities is widely used, mostly where functional images are fused with anatomical data. Ultrasound has for some time now been the standard imaging technique used for treatment planning of prostate cancer cases. While this approach is laudable and has yielded some positive results, latest developments have been the integration of images from ultrasound and other modalities such as PET-CT to compliment missing properties of ultrasound images. This study has sought to enhance diagnosis and treatment of prostate cancers by developing MATLAB algorithms to fuse ultrasound and PET-CT images. The fused ultrasound-PET-CT image has shown to contain improved quality of information than the individual input images. The fused image has the property of reduced uncertainty, increased reliability, robust system performance, and compact representation of information. The objective of co-registering the ultrasound and PET-CT images was achieved by conducting performance evaluation of the ultrasound and PET-CT imaging systems, developing image contrast enhancement algorithm, developing MATLAB image fusion algorithm, and assessing accuracy of the fusion algorithm. Performance evaluation of the ultrasound brachytherapy system produced satisfactory results in accordance with set tolerances as recommended by AAPM TG 128. Using an ultrasound brachytherapy quality assurance phantom, average axial distance measurement of 10.11 ± 0.11 mm was estimated. Average lateral distance measurements of 10.08 ± 0.07 mm, 20.01 ± 0.06 mm, 29.89 ± 0.03 mm and 39.84 ± 0.37 mm were estimated for the inter-target distances corresponding to 10 mm, 20 mm, 30 mm and 40 mm respectively. Volume accuracy assessment produced measurements of 3.97 cm3, 8.86 cm3 and 20.11 cm3 for known standard volumes of 4 cm3, 9 cm3 and 20 cm3 respectively. Depth of penetration assessment of the ultrasound system produced an estimate of 5.37 ± 0.02 cm, indicating the

  1. PET and PET/CT imaging for the earliest detection and treatment of colorectal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Carter, Kevin [Michigan State Univ., Pontiac, MI (United States). POH Medical Center; Kotlyarov, Eduard [Michigan State Univ., Pontiac, MI (United States). POH Medical Center; Georgetown Univ. (United States)

    2005-10-15

    Approximately 150,000 new cases of colorectal cancer are diagnosed each year with the life time risk of developing colon caner in developed nations being 4.6% in men and 3.2% in women. Screening patients is essential early detection of colon carcinoma to aid in complete resection. Unfortunately current screening methods carry with them poor patient compliance. PET and PET/CT may be a significant part of this screening solution. The authors reviewed and analyzed the English language articles and case reports identified on Medline during the last 10 years. PET and PET/CT results for colorectal carcinoma were tabulated and presented for the fifth Scientific Meeting of the Brazilian Society of Nuclear Biosciences. Though most studies have been retrospective analysis in using PET for staging for other malignant processes the cases that have identified additional uptake in the colon are important. The accuracy when utilizing PET and PET/CT in this screening method has a sensitivity between 65 and 90% with a specificity of 84 to 90% and a positive predictive value 71 to 78%. Early stages of malignancies and pre-cancerous polyps avidly accumulates F-18 Deoxyfluoro glucose allowing us to conclude that whole body PET and PET/CT is an essential component in the work up, staging or treatment monitoring in colon carcinoma. We have to continue to accumulate data for possible introduction for whole body PET and PET/CT scanning for colon carcinoma and precancerous polyps.(author)

  2. Combined image interpretation of computed tomography and hybrid PET in head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zimny, M.; Cremerius, U.; Nowak, B.; Buell, U. [Technische Hochschule Aachen (Germany). Klinik fuer Nuklearmedizin; Wildberger, J.E. [Dept. of Diagnostic Radiology, Univ. of Technology, Aachen (Germany); DiMartino, E. [Dept. of Otorhinolaryngology, Univ. of Technology, Aachen (Germany); Jaenicke, S. [Dept. of Maxillofacial and Facial Plastic Surgery, Univ. of Technology, Aachen (Germany)

    2002-02-01

    Aim: Evaluation of potential synergistic effects of combined image interpretation of FDG PET using a gamma camera modified for coincidence detection (hybrid PET) and computed tomography (CT) and comparison of the diagnostic accuracy of hybrid PET and dedicated PET in patients with head and neck cancer. Methods: Forty-two patient with suspected primary or recurrent cancer were included. Twenty-four patients underwent dedicated PET in addition to attenuation-corrected hybrid PET using a one-day protocol. Results: Sensitivity, specificity and accuracy for detection of primary or recurrent head and neck cancer were 74, 73, and 74% for hybrid PET, 52, 82, and 60% for CT and 77, 82, and 79% for combined reading. With the combination of CT and hybrid PET all cases of recurrent disease were detected. The largest tumour not detected was 1.7 cm in diameter. Sensitivity, specificity and accuracy for the detection of neck sides with lymph node metastases were 69, 88, and 85% for hybrid PET, 62, 88, and 84% for CT, 69, 99, and 94% for combined image interpretation. With combined interpretation four involved neck sides were missed including two cases of microscopic metastases. Hybrid PET revealed concordant results to dedicated PET in all patients with respect to the detection of primary or recurrent tumour and in 45 of 48 neck sides (94%) with the same number of false negative findings. Conclusion: The combination of functional information of hybrid PET and morphological information of CT by the simple approach of combined image interpretation improves the sensitivity for the detection of primary/recurrent head and neck cancer and increases the specificity of lymph node staging compared to CT alone. The accuracy of hybrid PET and dedicated PET was almost identical. (orig.)

  3. Application of PET and PET/CT imaging for cancer screening

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the potential application of 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) and PET/CT for cancer screening in asymptomatic individuals. Methods: The subjects consisted of 3631 physical check up examinees (1947 men, 1684 women; mean age ±SD, 52.1±8.2 y) with non-specific medical histories. Whole-body FDG PET (or PET/CT), ultrasound and tumor markers were performed on all patients. Focal hypermetabolic areas with intensities equal to or exceeding the level of FDG uptake in the brain and bladder were considered abnormal and interpreted as neoplasia. Follow-up periods were longer than one year. Results: Among the 3631 FDG PET (including 1687 PET/CT), ultrasound and tumor markers examinations, malignant tumors were discovered in 47 examinees (1.29%). PET findings were true-positive in 38 of the 47 cancers (80.9%). In addition, 32 of the 47 cancers were performed with the PET-CT scan. PET detected cancer lesions in 28 of the 32 examinees. However, the CT detected cancer lesions in only 15 of 32 examinees. Conclusion: The sensitivity of FDG PET in the detection of a wide variety of cancers is high. Most cancer can be detected with FDG PET in a resectable stage. CT of the PET/CT for localization and characteristics of the lesion shows an increased specificity of the PET scan. Using ultrasound and tumor markers may complement the PET scan in cancer screening for hepatic and urologic neoplasms. (authors)

  4. Tau PET: the next frontier in molecular imaging of dementia.

    Science.gov (United States)

    Xia, Chenjie; Dickerson, Bradford C

    2016-09-01

    We have arrived at an exciting juncture in dementia research: the second major pathological hallmark of Alzheimer's disease (AD)-tau-can now be seen for the first time in the living human brain. The major proteinopathies in AD include amyloid-β plaques and neurofibrillary tangles (NFTs) made of hyperphosphorylated paired helical filament (PHF) tau. Since its advent more than a decade ago, amyloid PET imaging has revolutionized the field of dementia research, enabling more confident diagnosis of the likely pathology in patients with a variety of clinical dementia syndromes, paving the way for the identification of people with preclinical or prodromal AD pathology, and serving as a minimally invasive molecular readout in clinical trials of putative disease-modifying interventions. Now that we are on the brink of a second revolution in molecular imaging in dementia, it is worth considering the likely potential impact of this development on the field. PMID:27334648

  5. Myocardial perfusion imaging using SPECT/CT and PET/CT; Myokardperfusionsszintigrafie mit SPECT/CT und PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, Marcus; Uebleis, C. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Univ. Muenchen (Germany)

    2010-06-15

    With technical progress coronary CT angiography is increasingly accepted as a noninvasive alternative in morphological imaging. However, image quality and interpretation are still influenced by various factors like blooming artifacts, misregistration and the experience of the interpreter. The combination with stress-rest myocardial perfusion SPECT or PET as a hybrid scanner or two standalone scanners enables comprehensive noninvasive anatomical and functional imaging of the heart as well as three dimensional image fusion. Hybrid-imaging is feasible with today's commercially available software packages but still requires time demanding manual intervention and experienced interpretation. PET investigations, either in replacement of SPECT for perfusion measurements, or in addition with new biomarkers will provide even more impact to hybrid imaging in future. (orig.)

  6. Transmission imaging for integrated PET-MR systems

    Science.gov (United States)

    Bowen, Spencer L.; Fuin, Niccolò; Levine, Michael A.; Catana, Ciprian

    2016-08-01

    Attenuation correction for PET-MR systems continues to be a challenging problem, particularly for body regions outside the head. The simultaneous acquisition of transmission scan based μ-maps and MR images on integrated PET-MR systems may significantly increase the performance of and offer validation for new MR-based μ-map algorithms. For the Biograph mMR (Siemens Healthcare), however, use of conventional transmission schemes is not practical as the patient table and relatively small diameter scanner bore significantly restrict radioactive source motion and limit source placement. We propose a method for emission-free coincidence transmission imaging on the Biograph mMR. The intended application is not for routine subject imaging, but rather to improve and validate MR-based μ-map algorithms; particularly for patient implant and scanner hardware attenuation correction. In this study we optimized source geometry and assessed the method’s performance with Monte Carlo simulations and phantom scans. We utilized a Bayesian reconstruction algorithm, which directly generates μ-map estimates from multiple bed positions, combined with a robust scatter correction method. For simulations with a pelvis phantom a single torus produced peak noise equivalent count rates (34.8 kcps) dramatically larger than a full axial length ring (11.32 kcps) and conventional rotating source configurations. Bias in reconstructed μ-maps for head and pelvis simulations was  ⩽4% for soft tissue and  ⩽11% for bone ROIs. An implementation of the single torus source was filled with 18F-fluorodeoxyglucose and the proposed method quantified for several test cases alone or in comparison with CT-derived μ-maps. A volume average of 0.095 cm‑1 was recorded for an experimental uniform cylinder phantom scan, while a bias of  images with significantly higher SNR than competing fixed geometries at matched total acquisition time.

  7. PET/CT imaging of human somatostatin receptor 2 (hsstr2) as reporter gene for gene therapy

    Science.gov (United States)

    Hofmann, M.; Gazdhar, A.; Weitzel, T.; Schmid, R.; Krause, T.

    2006-12-01

    Localized information on region-selective gene expression in small animals is widely obtained by use of reporter genes inducing light emission. Using these reporter genes for imaging deep inside the human body fluorescent probes are hindered by attenuation, scattering and possible fluorescence quenching. This can be overcome by use of radio-peptide receptors as reporter genes. Therefore, the feasibility of the somatostatin receptor 2 expression vector system for expression imaging was checked against a control vector containing luciferase gene. For in vivo transduction of vector DNA into the rat forelimb muscles the in vivo electroporation technique was chosen because of its high regio-selectivity. The gene expression was imaged by high-sensitive CCD camera (luciferase activity) and by PET/CT using a Ga-68-DOTATOC as radio peptide probe. The relative sstr2 expression was enhanced by gene transduction at maximum to a factor of 15. The PET/CT images could be fully quantified. The above demonstrated feasibility of radio-peptide PET/CT reporter gene imaging may serve in the future as a tool for full quantitative understanding of regional gene expression, especially in large animals and humans.

  8. An update on novel quantitative techniques in the context of evolving whole-body PET imaging

    DEFF Research Database (Denmark)

    Houshmand, Sina; Salavati, Ali; Hess, Søren;

    2015-01-01

    Since its foundation PET has established itself as one of the standard imaging modalities enabling the quantitative assessment of molecular targets in vivo. In the past two decades, quantitative PET has become a necessity in clinical oncology. Despite introduction of various measures...... for quantification and correction of PET parameters, there is debate on the selection of the appropriate methodology in specific diseases and conditions. In this review, we have focused on these techniques with special attention to topics such as static and dynamic whole body PET imaging, tracer kinetic modeling...

  9. Noninvasive Bioluminescence Imaging in Small Animals

    OpenAIRE

    Zinn, Kurt R.; Chaudhuri, Tandra R.; Szafran, April Adams; O’Quinn, Darrell; Weaver, Casey; Dugger, Kari; Lamar, Dale; Kesterson, Robert A.; Wang, Xiangdong; Frank, Stuart J.

    2008-01-01

    There has been a rapid growth of bioluminescence imaging applications in small animal models in recent years, propelled by the availability of instruments, analysis software, reagents, and creative approaches to apply the technology in molecular imaging. Advantages include the sensitivity of the technique as well as its efficiency, relatively low cost, and versatility. Bioluminescence imaging is accomplished by sensitive detection of light emitted following chemical reaction of the luciferase...

  10. Protocol requirements and diagnostic value of PET/MR imaging for liver metastasis detection

    Energy Technology Data Exchange (ETDEWEB)

    Reiner, Caecilia S. [University Hospital Zurich, Diagnostic and Interventional Radiology, Zurich (Switzerland); Stolzmann, Paul [University Hospital Zurich, Diagnostic and Interventional Radiology, Zurich (Switzerland); University Hospital Zurich, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Division of Nuclear Medicine, Zurich (Switzerland); Husmann, Lars; Burger, Irene A.; Huellner, Martin W.; Schulthess, Gustav K. von [University Hospital Zurich, Nuclear Medicine, Zurich (Switzerland); Schaefer, Niklaus G. [University Hospital Zurich, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Oncology, Zurich (Switzerland); Schneider, Paul M. [University Hospital Zurich, Visceral and Transplant Surgery, Zurich (Switzerland); Veit-Haibach, Patrick [University Hospital Zurich, Diagnostic and Interventional Radiology, Zurich (Switzerland); University Hospital Zurich, Nuclear Medicine, Zurich (Switzerland)

    2014-04-15

    To compare the accuracy of PET/MR imaging with that of FDG PET/CT and to determine the MR sequences necessary for the detection of liver metastasis using a trimodality PET/CT/MR set-up. Included in this single-centre IRB-approved study were 55 patients (22 women, age 61 ± 11 years) with suspected liver metastases from gastrointestinal cancer. Imaging using a trimodality PET/CT/MR set-up (time-of-flight PET/CT and 3-T whole-body MR imager) comprised PET, low-dose CT, contrast-enhanced (CE) CT of the abdomen, and MR with T1-W/T2-W, diffusion-weighted (DWI), and dynamic CE imaging. Two readers evaluated the following image sets for liver metastasis: PET/CT (set A), PET/CECT (B), PET/MR including T1-W/T2-W (C), T1-W/T2-W with either DWI (D) or CE imaging (E), and a combination (F). The accuracy of each image set was determined by receiver-operating characteristic analysis using image set B as the standard of reference. Of 120 liver lesions in 21/55 patients (38 %), 79 (66 %) were considered malignant, and 63/79 (80 %) showed abnormal FDG uptake. Accuracies were 0.937 (95 % CI 89.5 - 97.9 %) for image set A, 1.00 (95 % CI 99.9 - 100.0 %) for set C, 0.998 (95 % CI 99.4 - 100.0 %) for set D, 0.997 (95 % CI 99.3 - 100.0 %) for set E, and 0.995 (95 % CI 99.0 - 100.0 %) for set F. Differences were significant for image sets D - F (P < 0.05) when including lesions without abnormal FDG uptake. As shown by follow-up imaging after 50 - 177 days, the use of image sets D and both sets E and F led to the detection of metastases in one and three patients, respectively, and further metastases in the contralateral lobe in two patients negative on PET/CECT (P = 0.06). PET/MR imaging with T1-W/T2-W sequences results in similar diagnostic accuracy for the detection of liver metastases to PET/CECT. To significantly improve the characterization of liver lesions, we recommend the use of dynamic CE imaging sequences. PET/MR imaging has a diagnostic impact on clinical decision making. (orig.)

  11. Monte Carlo simulations versus experimental measurements in a small animal PET system. A comparison in the NEMA NU 4-2008 framework

    Science.gov (United States)

    Popota, F. D.; Aguiar, P.; España, S.; Lois, C.; Udias, J. M.; Ros, D.; Pavia, J.; Gispert, J. D.

    2015-01-01

    In this work a comparison between experimental and simulated data using GATE and PeneloPET Monte Carlo simulation packages is presented. All simulated setups, as well as the experimental measurements, followed exactly the guidelines of the NEMA NU 4-2008 standards using the microPET R4 scanner. The comparison was focused on spatial resolution, sensitivity, scatter fraction and counting rates performance. Both GATE and PeneloPET showed reasonable agreement for the spatial resolution when compared to experimental measurements, although they lead to slight underestimations for the points close to the edge. High accuracy was obtained between experiments and simulations of the system’s sensitivity and scatter fraction for an energy window of 350-650 keV, as well as for the counting rate simulations. The latter was the most complicated test to perform since each code demands different specifications for the characterization of the system’s dead time. Although simulated and experimental results were in excellent agreement for both simulation codes, PeneloPET demanded more information about the behavior of the real data acquisition system. To our knowledge, this constitutes the first validation of these Monte Carlo codes for the full NEMA NU 4-2008 standards for small animal PET imaging systems.

  12. Monte Carlo simulations versus experimental measurements in a small animal PET system. A comparison in the NEMA NU 4-2008 framework

    International Nuclear Information System (INIS)

    In this work a comparison between experimental and simulated data using GATE and PeneloPET Monte Carlo simulation packages is presented. All simulated setups, as well as the experimental measurements, followed exactly the guidelines of the NEMA NU 4-2008 standards using the microPET R4 scanner. The comparison was focused on spatial resolution, sensitivity, scatter fraction and counting rates performance. Both GATE and PeneloPET showed reasonable agreement for the spatial resolution when compared to experimental measurements, although they lead to slight underestimations for the points close to the edge. High accuracy was obtained between experiments and simulations of the system’s sensitivity and scatter fraction for an energy window of 350–650 keV, as well as for the counting rate simulations. The latter was the most complicated test to perform since each code demands different specifications for the characterization of the system’s dead time. Although simulated and experimental results were in excellent agreement for both simulation codes, PeneloPET demanded more information about the behavior of the real data acquisition system. To our knowledge, this constitutes the first validation of these Monte Carlo codes for the full NEMA NU 4-2008 standards for small animal PET imaging systems. (paper)

  13. A Comparison of Imaging Techniques to Monitor Tumor Growth and Cancer Progression in Living Animals

    Directory of Open Access Journals (Sweden)

    Anne-Laure Puaux

    2011-01-01

    Full Text Available Introduction and Purpose. Monitoring solid tumor growth and metastasis in small animals is important for cancer research. Noninvasive techniques make longitudinal studies possible, require fewer animals, and have greater statistical power. Such techniques include FDG positron emission tomography (FDG-PET, magnetic resonance imaging (MRI, and optical imaging, comprising bioluminescence imaging (BLI and fluorescence imaging (FLI. This study compared the performance and usability of these methods in the context of mouse tumor studies. Methods. B16 tumor-bearing mice (n=4 for each study were used to compare practicality, performance for small tumor detection and tumor burden measurement. Using RETAAD mice, which develop spontaneous melanomas, we examined the performance of MRI (n=6 mice and FDG-PET (n=10 mice for tumor identification. Results. Overall, BLI and FLI were the most practical techniques tested. Both BLI and FDG-PET identified small nonpalpable tumors, whereas MRI and FLI only detected macroscopic, clinically evident tumors. FDG-PET and MRI performed well in the identification of tumors in terms of specificity, sensitivity, and positive predictive value. Conclusion. Each of the four methods has different strengths that must be understood before selecting them for use.

  14. Radionuclide imaging of spinal osteomyelitis: prospective comparison of FDG-PET and Ga-SPECT

    International Nuclear Information System (INIS)

    Aim: MRI is currently recognized as the imaging modality of choice for diagnosing spinal osteomyelitis. Radionuclide imaging with 67Ga citrate (Ga) is usually reserved for those situations in which the MRI cannot be performed or is inconclusive. The delay between injection of radiogallium and imaging, typically 48 -72 hours, as well as the unfavorable imaging characteristics of this radionuclide are disadvantages of the procedure. There are data that suggest that 18F-FDG-PET (FDG-PET) imaging may be useful for diagnosing spinal osteomyelitis. We are prospectively studying the role of FDG-PET in the diagnosis of spinal osteomyelitis, and comparing it to Ga for this purpose. Materials and Methods: To date, 8 patients, 5 males and 3 females, 44 - 74 years old have undergone Ga-SPECT and FDG-PET imaging within 48 hours of each other. The regions of concern were: cervical spine (n=1), thoracic spine (n=2), and lumbar spine (n=5). Results: Five patients had spinal osteomyelitis; one patient also had an adjacent psoas abscess. Final diagnoses in the 3 remaining patients were degenerative joint disease, soft tissue infection, and chronic demyelinating polyneuropathy. Imaging results are presented. FDG-PET vs Gallium-SPECT. Results of FDG-PET and Ga-SPECT were concordant in all 8 patients. Conclusion: Although further study in a larger population is needed, FDG-PET, which is rapidly completed and has superior image quality, may emerge as the radionuclide imaging procedure of choice for diagnosing spinal osteomyelitis

  15. Molecular Imaging in Breast Cancer: From Whole-Body PET/CT to Dedicated Breast PET

    Directory of Open Access Journals (Sweden)

    B. B. Koolen

    2012-01-01

    Full Text Available Positron emission tomography (PET, with or without integrated computed tomography (CT, using 18F-fluorodeoxyglucose (FDG is based on the principle of elevated glucose metabolism in malignant tumors, and its use in breast cancer patients is frequently being investigated. It has been shown useful for classification, staging, and response monitoring, both in primary and recurrent disease. However, because of the partial volume effect and limited resolution of most whole-body PET scanners, sensitivity for the visualization of small tumors is generally low. To improve the detection and quantification of primary breast tumors with FDG PET, several dedicated breast PET devices have been developed. In this nonsystematic review, we shortly summarize the value of whole-body PET/CT in breast cancer and provide an overview of currently available dedicated breast PETs.

  16. Automatic cardiac gating of small-animal PET from list-mode data

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J.L.; Udias, J.M. [Universidad Complutense de Madrid Univ. (Spain). Grupo de Fisica Nuclear; Vaquero, J.J.; Desco, M. [Universidad Carlos III de Madrid (Spain). Dept. de Bioingenieria e Ingenieria Aeroespacial; Cusso, L. [Hospital General Universitario Gregorio Maranon, Madrid (Spain). Unidad de Medicina y Cirugia Experimental

    2011-07-01

    This work presents a method to obtain automatically the cardiac gating signal in a PET study of rats, by employing the variation with time of the counts in the cardiac region, that can be extracted from list-mode data. In an initial step, the cardiac region is identified in the image space by backward-projecting a small fraction of the acquired data and studying the variation with time of the counts in each voxel inside said region, with frequencies within 2 and 8 Hz. The region obtained corresponds accurately to the left-ventricle of the heart of the rat. In a second step, the lines-of-response (LORs) connected with this region are found by forward-projecting this region. The time variation of the number of counts in these LORs contains the cardiac motion information that we want to extract. This variation of counts with time is band-pass filtered to reduce noise, and the time signal so obtained is used to create the gating signal. The result was compared with a cardiac gating signal obtained from an ECG acquired simultaneously to the PET study. Reconstructed gated images obtained from both gating information are similar. The method proposed demonstrates that valid cardiac gating signals can be obtained for rats from PET list-mode data. (orig.)

  17. Evaluation of anesthesia effects on [{sup 18}F]FDG uptake in mouse brain and heart using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Hiroshi E-mail: htoyama@fujita-hu.ac.jp; Ichise, Masanori; Liow, Jeih-San; Vines, Douglass C.; Seneca, Nicholas M.; Modell, Kendra J.; Seidel, Jurgen; Green, Michael V.; Innis, Robert B

    2004-02-01

    This study evaluates effects of anesthesia on {sup 18}F-FDG (FDG) uptake in mouse brain and heart to establish the basic conditions of small animal PET imaging. Prior to FDG injection, 12 mice were anesthetized with isoflurane gas; 11 mice were anesthetized with an intraperitoneal injection of a ketamine/xylazine mixture; and 11 mice were awake. In isoflurane and ketamine/xylazine conditions, FDG brain uptake (%ID/g) was significantly lower than in controls. Conversely, in the isoflurane condition, %ID/g in heart was significantly higher than in controls, whereas heart uptake in ketamine/xylazine mice was significantly lower. Results suggest that anesthesia impedes FDG uptake in mouse brain and affects FDG uptake in heart; however, the effects in the brain and heart differ depending on the type of anesthesia used.

  18. Automatic extraction of myocardial mass and volumes using parametric images from dynamic non-gated PET

    DEFF Research Database (Denmark)

    Harms, Hans; Hansson, Nils Henrik Stubkjær; Tolbod, Lars Poulsen;

    2016-01-01

    -gated dynamic cardiac PET. METHODS: Thirty-five patients with aortic-valve stenosis and 10 healthy controls (HC) underwent a 27-min 11C-acetate PET/CT scan and cardiac magnetic resonance imaging (CMR). HC were scanned twice to assess repeatability. Parametric images of uptake rate K1 and the blood pool were......LV and WT only and an overestimation for LVEF at lower values. Intra- and inter-observer correlations were >0.95 for all PET measurements. PET repeatability accuracy in HC was comparable to CMR. CONCLUSION: LV mass and volumes are accurately and automatically generated from dynamic 11C-acetate PET without...... ECG-gating. This method can be incorporated in a standard routine without any additional workload and can, in theory, be extended to other PET tracers....

  19. A CT-, PET- and MR-imaging-compatible hyperbaric pressure chamber for baromedical research

    DEFF Research Database (Denmark)

    Hansen, Kasper; Søvsø Szocska Hansen, Esben; Tolbod, Lars P;

    2015-01-01

    OBJECTIVES: We describe the development of a novel preclinical rodent-sized pressure chamber system compatible with computed tomography (CT), positron emission tomography (PET) and magnetic resonance imaging (MRI) that allows continuous uncompromised and minimally invasive data acquisition...... different tissues in the MRI phantoms. CONCLUSION: This study demonstrates a pressure chamber system compatible with CT, PET and MRI. We found that no correction in image intensity was required with pressurisation up to 1.013 mPa for any imaging modality. CT, PET or MRI can be used to obtain anatomical...... throughout hyperbaric exposures. The effect of various pressures on the acquired image intensity obtained with different CT, PET and MRI phantoms are characterised. MATERIAL AND METHODS: Tissue-representative phantom models were examined with CT, PET or MRI at normobaric pressure and hyperbaric pressures up...

  20. Heterogeneity in stabilization phenomena in FLT PET images of canines

    Science.gov (United States)

    Simoncic, Urban; Jeraj, Robert

    2014-12-01

    3ʹ-(18F)fluoro-3ʹ-deoxy-L-thymidine (FLT) is a PET marker of cellular proliferation. Its tissue uptake rate is often quantified with a Standardized Uptake Value (SUV), although kinetic analysis provides a more accurate quantification. The purpose of this study is to investigate the heterogeneity in FLT stabilization phenomena. The study was done on 15 canines with spontaneously occurring sinonasal tumours. They were imaged dynamically for 90 min with FLT PET/CT twice; before and during the radiotherapy. Images were analyzed for kinetics on a voxel basis through compartmental analysis. Stabilization curves were calculated as a time-dependant correlation between the time-dependant SUV and the kinetic parameters (voxel values within the tumour were correlated). Stabilization curves were analyzed for stabilization speed, maximal correlation and correlation decrease following the maximal correlation. These stabilization parameters were correlated with the region-averaged kinetic parameters. The FLT SUV was highly correlated with vasculature fraction immediately post-injection, followed by maximum in correlation with the perfusion/permeability. At later times post-injection the FLT SUV was highly correlated (Pearson correlation coefficient above 0.95) with the FLT influx parameter for cases with tumour-averaged SUV30-50 min above 2, while others were indeterminate (correlation coefficients from 0.1 to 0.97). All cases with highly correlated SUV and FLT influx parameter had correlation coefficient within 0.5% of its maximum in the period of 30-50 min post-injection. Stabilization time was inversely proportional to the FLT influx rate. Correlation between the FLT SUV and FLT influx parameter dropped at later times post-injection with drop being proportional to the dephosphorylation rate. The FLT was found to be metabolically stable in canines. FLT PET imaging protocol should define minimal and maximal FLT uptake period, which would be 30-50 min for our patients

  1. In vivo PET imaging of brain nicotinic cholinergic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Bottlaender, M.; Valette, H.; Saba, W.; Schollhorn-Peyronneau, M.A.; Dolle, F.; Syrota, A. [Service Hospitalier Frederic Joliot (CEA/DSV/DRM), 91 - Orsay (France)

    2006-07-01

    Neuronal acetylcholine receptors (nAChRs) are widely distributed throughout the central nervous system where they modulate a number of CNS functions including neurotransmitter release, cognitive function, anxiety, analgesia and control of cerebral blood flow. In the brain, a major subtype is composed of the {alpha}4{beta}2 subunit combination. Density of this subtype has been shown to be decreased in patients with neuro-degenerative disease such as Alzheimer and Parkinson's disease (AD and PD), and mutated receptors has been described in some familial epilepsy. Thus, in vivo mapping of the nicotinic nAChRs by Positron Emission Tomography (PET) are of great interest to monitor the evolution of these pathologies and changes in the neuronal biochemistry induced by therapeutic agents. Recently, a new compound, 3-[2(S)-2-azetidinyl-methoxy]pyridine (A-85380) has been synthesised and labelled with fluorine-18, [{sup 18}F]fluoro-A-85380 (Dolle et al., 1999). The [{sup 18}F]fluoro-A-85380 has been shown to bind with high affinity t o nAChRs in vitro (Saba et al., 2004), and its toxicity was low and compatible with it s use at tracer dose in human PET studies (Valette, 2002). PET studies in baboons showed that, after in vivo administration of [ {sup 18}F]fluoro-A-85380 at a tracer dose, the distribution of the radioactivity in the brain reflect the distribution of the < 4R2 nAChRs. Competition and pre-blocking studies, using nicotinic agonists, confirm that the radiotracer binds specifically to the heteromeric nAChRs in the brain (Valette et al., 1999). The in vivo, characteristics of the [{sup 18}F]fluoro-A-8538 0 combined with its low toxicity make possible the imaging of the nicotinic receptor s in human by PET (Bottlaender 2003). Studies were performed in healthy non-smoker volunteers to evaluate the brain kinetics of [{sup 18}F]fluoro-A-85380 and to assess the quantification of its nAChRs binding in the human brain with PET (Gallezot et a., 2005). The [{sup 18}F

  2. Bioluminescence imaging in live cells and animals.

    Science.gov (United States)

    Tung, Jack K; Berglund, Ken; Gutekunst, Claire-Anne; Hochgeschwender, Ute; Gross, Robert E

    2016-04-01

    The use of bioluminescent reporters in neuroscience research continues to grow at a rapid pace as their applications and unique advantages over conventional fluorescent reporters become more appreciated. Here, we describe practical methods and principles for detecting and imaging bioluminescence from live cells and animals. We systematically tested various components of our conventional fluorescence microscope to optimize it for long-term bioluminescence imaging. High-resolution bioluminescence images from live neurons were obtained with our microscope setup, which could be continuously captured for several hours with no signs of phototoxicity. Bioluminescence from the mouse brain was also imaged noninvasively through the intact skull with a conventional luminescence imager. These methods demonstrate how bioluminescence can be routinely detected and measured from live cells and animals in a cost-effective way with common reagents and equipment.

  3. How Phoenix Creates Color Images (Animation)

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation This simple animation shows how a color image is made from images taken by Phoenix. The Surface Stereo Imager captures the same scene with three different filters. The images are sent to Earth in black and white and the color is added by mission scientists. By contrast, consumer digital cameras and cell phones have filters built in and do all of the color processing within the camera itself. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASAaE(TM)s Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  4. PET Evidence of the Effect of Donepezil on Cognitive Performance in an Animal Model of Chemobrain.

    Science.gov (United States)

    Lim, Ilhan; Joung, Hye-Young; Yu, A Ram; Shim, Insop; Kim, Jin Su

    2016-01-01

    A considerable number of patients with breast cancer complain of cognitive impairment after chemotherapy. In this study, we showed that donepezil enhanced memory function and increased brain glucose metabolism in a rat model of cognitive impairment after chemotherapy using behavioral analysis and positron emission tomography (PET). We found that chemotherapy affected spatial learning ability, reference memory, and working memory and that donepezil improved these cognitive impairments. According to PET analysis, chemotherapy reduced glucose metabolism in the medial prefrontal cortex and hippocampus, and donepezil increased glucose metabolism in the bilateral frontal lobe, parietal lobe, and hippocampus. Reduced glucose metabolism was more prominent after treatment with doxorubicin than cyclophosphamide. Our results demonstrated the neural mechanisms for cognitive impairment after chemotherapy and show that cognition was improved after donepezil intervention using both behavioral and imaging methods. Our results suggested that donepezil can be employed clinically for the treatment of cognitive deficits after chemotherapy. PMID:27556039

  5. PET Evidence of the Effect of Donepezil on Cognitive Performance in an Animal Model of Chemobrain

    Directory of Open Access Journals (Sweden)

    Ilhan Lim

    2016-01-01

    Full Text Available A considerable number of patients with breast cancer complain of cognitive impairment after chemotherapy. In this study, we showed that donepezil enhanced memory function and increased brain glucose metabolism in a rat model of cognitive impairment after chemotherapy using behavioral analysis and positron emission tomography (PET. We found that chemotherapy affected spatial learning ability, reference memory, and working memory and that donepezil improved these cognitive impairments. According to PET analysis, chemotherapy reduced glucose metabolism in the medial prefrontal cortex and hippocampus, and donepezil increased glucose metabolism in the bilateral frontal lobe, parietal lobe, and hippocampus. Reduced glucose metabolism was more prominent after treatment with doxorubicin than cyclophosphamide. Our results demonstrated the neural mechanisms for cognitive impairment after chemotherapy and show that cognition was improved after donepezil intervention using both behavioral and imaging methods. Our results suggested that donepezil can be employed clinically for the treatment of cognitive deficits after chemotherapy.

  6. PET Evidence of the Effect of Donepezil on Cognitive Performance in an Animal Model of Chemobrain

    Science.gov (United States)

    Lim, Ilhan; Yu, A Ram

    2016-01-01

    A considerable number of patients with breast cancer complain of cognitive impairment after chemotherapy. In this study, we showed that donepezil enhanced memory function and increased brain glucose metabolism in a rat model of cognitive impairment after chemotherapy using behavioral analysis and positron emission tomography (PET). We found that chemotherapy affected spatial learning ability, reference memory, and working memory and that donepezil improved these cognitive impairments. According to PET analysis, chemotherapy reduced glucose metabolism in the medial prefrontal cortex and hippocampus, and donepezil increased glucose metabolism in the bilateral frontal lobe, parietal lobe, and hippocampus. Reduced glucose metabolism was more prominent after treatment with doxorubicin than cyclophosphamide. Our results demonstrated the neural mechanisms for cognitive impairment after chemotherapy and show that cognition was improved after donepezil intervention using both behavioral and imaging methods. Our results suggested that donepezil can be employed clinically for the treatment of cognitive deficits after chemotherapy. PMID:27556039

  7. Ga-68-labeled neolactosylated human serum albumin (LSA) for PET imaging of hepatic asialoglycoprotein receptor

    International Nuclear Information System (INIS)

    Introduction: The purpose of this study was the development of 68Ga-labeled neolactosylated human serum albumin (LSA) for imaging asialoglycoprotein receptors in the liver by using positron emission tomography (PET), which would enable functional imaging with higher resolution than single-photon emission computed tomography (SPECT). Methods: LSA was synthesized by conjugating α-lactose to human serum albumin (HSA) by reductive amination. LSA was conjugated with 2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (SCN-NOTA) and the resultant NOTA-LSA was labeled with 68Ga at room temperature. The labeling efficiency of NOTA-LSA was evaluated as a function of pH and time. The stability of 68Ga-NOTA-LSA in phosphate buffered saline (PBS) and human serum at 37 °C was determined. Biodistribution and PET studies of 68Ga-NOTA-LSA were performed in mice following tail vein injection of radiotracer. Results: The numbers of lactose and NOTA units per HSA were determined to be 31.7 and 4.6, respectively. When the reaction was done at room temperature, the labeling efficiency of NOTA-LSA was higher than 99% at pH 4.8 and 96% at pH 6. More than 95% of the detected radioactivity was associated with the intact molecule for at least the 4 h following synthesis when incubated in PBS or human serum at 37 °C. Biodistribution and animal PET studies showed specific retention of 68Ga-NOTA-LSA in liver following intravenous administration. Conclusion: 68Ga-NOTA-LSA was successfully developed for imaging asialoglycoprotein receptors in the liver with a simple labeling method, high labeling efficiency, and high stability

  8. PET Imaging of Skeletal Metastases and Its Role in Personalizing Further Management.

    Science.gov (United States)

    Mahajan, Abhishek; Azad, Gurdip Kaur; Cook, Gary J

    2016-07-01

    In oncology, the skeleton is one of the most frequently encountered sites for metastatic disease and thus early detection not only has an impact on an individual patient's management but also on the overall outcome. Multiparametric and multimodal hybrid PET/computed tomography and PET/MR imaging have revolutionized imaging for bone metastases, but irrespective of tumor biology or morphology of the bone lesion it remains unclear which imaging modality is the most clinically relevant to guide individualized cancer care. In this review, we highlight the current clinical challenges of PET imaging in evaluation and quantification of skeletal tumor burden and its impact on personalized cancer management. PMID:27321034

  9. EXPLORER: Changing the molecular imaging paradigm with total-body PET/CT (Conference Presentation)

    Science.gov (United States)

    Cherry, Simon R.; Badawi, Ramsey D.; Jones, Terry

    2016-04-01

    Positron emission tomography (PET) is the highest sensitivity technique for human whole-body imaging studies. However, current clinical PET scanners do not make full use of the available signal, as they only permit imaging of a 15-25 cm segment of the body at one time. Given the limited sensitive region, whole-body imaging with clinical PET scanners requires relatively long scan times and subjects the patient to higher than necessary radiation doses. The EXPLORER initiative aims to build a 2-meter axial length PET scanner to allow imaging the entire subject at once, capturing nearly the entire available PET signal. EXPLORER will acquire data with ~40-fold greater sensitivity leading to a six-fold increase in reconstructed signal-to-noise ratio for imaging the total body. Alternatively, total-body images with the EXPLORER scanner will be able to be acquired in ~30 seconds or with ~0.15 mSv injected dose, while maintaining current PET image quality. The superior sensitivity will open many new avenues for biomedical research. Specifically for cancer applications, high sensitivity PET will enable detection of smaller lesions. Additionally, greater sensitivity will allow imaging out to 10 half-lives of positron emitting radiotracers. This will enable 1) metabolic ultra-staging with FDG by extending the uptake and clearance time to 3-5 hours to significantly improve contrast and 2) improved kinetic imaging with short-lived radioisotopes such as C-11, crucial for drug development studies. Frequent imaging studies of the same subject to study disease progression or to track response to therapy will be possible with the low dose capabilities of the EXPLORER scanner. The low dose capabilities will also open up new imaging possibilities in pediatrics and adolescents to better study developmental disorders. This talk will review the basis for developing total-body PET, potential applications, and review progress to date in developing EXPLORER, the first total-body PET scanner.

  10. Automatic co-segmentation of lung tumor based on random forest in PET-CT images

    Science.gov (United States)

    Jiang, Xueqing; Xiang, Dehui; Zhang, Bin; Zhu, Weifang; Shi, Fei; Chen, Xinjian

    2016-03-01

    In this paper, a fully automatic method is proposed to segment the lung tumor in clinical 3D PET-CT images. The proposed method effectively combines PET and CT information to make full use of the high contrast of PET images and superior spatial resolution of CT images. Our approach consists of three main parts: (1) initial segmentation, in which spines are removed in CT images and initial connected regions achieved by thresholding based segmentation in PET images; (2) coarse segmentation, in which monotonic downhill function is applied to rule out structures which have similar standardized uptake values (SUV) to the lung tumor but do not satisfy a monotonic property in PET images; (3) fine segmentation, random forests method is applied to accurately segment the lung tumor by extracting effective features from PET and CT images simultaneously. We validated our algorithm on a dataset which consists of 24 3D PET-CT images from different patients with non-small cell lung cancer (NSCLC). The average TPVF, FPVF and accuracy rate (ACC) were 83.65%, 0.05% and 99.93%, respectively. The correlation analysis shows our segmented lung tumor volumes has strong correlation ( average 0.985) with the ground truth 1 and ground truth 2 labeled by a clinical expert.

  11. Molecular identification of Cryptosporidium isolates from exotic pet animals in Japan.

    Science.gov (United States)

    Abe, Niichiro; Matsubara, Katsuki

    2015-04-30

    The Cryptosporidium horse genotype, a zoonotic protozoan parasite first found in a Prezewalski wild horse, has not been found in any other mammal but calves, horses, and humans. Hedgehogs, popular exotic pet animals in Japan, are a reservoir of two zoonotic Cryptosporidum: C. parvum and C. erinacei (previously known as the hedgehog genotype). Recently, after finding Cryptosporidium infection in a four-toed hedgehog (Atelerix albiventris), we identified the isolate genetically as the Cryptosporidium horse genotype. Its subtype (VIbA13) was the same as that of an isolate from a pet shop employee with severe clinical symptoms, as reported previously from sequencing analysis of the partial Cryptosporidum 60kDa glycoprotein gene sequence. The occurrence of this genotype in hedgehog indicates that the horse genotype has broad host specificity. This report is the first of a study identifying isolates from pet reptiles genetically in Japan. The study identified a new host (Teratoscincus scincus) in C. serpentis lizard genotype by sequencing analysis of partial SSU rRNA and actin genes. PMID:25801359

  12. PET in tumor imaging: research only or a cost effective clinical tool?

    International Nuclear Information System (INIS)

    PET imaging has for many years been a versatile tool for non-invasive imaging of neuro-physiology and, indeed, whole body physiology. Quantitative PET imaging of trace amounts of radioactivity is scientifically elegant and can be very complex. This lecture focuses on whether and where this test is clinically useful. Because of the research tradition, PET imaging has been perceived as an 'expensive' test, as it costs more per scan than CT and MRI scans at most institutions. Such a superficial analysis is incorrect, however, as it is increasingly recognized that imaging costs, which in some circumstances will be increased by the use of PET, are only a relatively small component of patient care costs. Thus, PET may raise imaging costs and the number of imaging procedures in some settings, though PET may reduce imaging test numbers in other settings. However, the analysis must focus on the total costs of patient management. Analyses focused on total patient care costs, including cost of hospitalization and cost surgery as well as imaging costs, have shown that PET can substantially reduce total patient care costs in several settings. This is achieved by providing a more accurate diagnosis, and thus having fewer instances of an incorrect diagnosis resulting in subsequent inappropriate surgery or investigations. Several institutions have shown scenarios in which PET for tumor imaging is cost effective. While the specific results of the analyses vary based on disease prevalence and cost input values for each procedure, as well as the projected performance of PET, the similar results showing total care cost savings in the management of several common cancers, strongly supports the rational for the use of PET in cancer management. In addition, promising clinical results are forthcoming in several other illnesses, suggesting PET will have broader utility than these uses, alone. Thus, while PET is an 'expensive' imaging procedure and has considerable utility as a research

  13. The additional value of PET/CT over PET in FDG imaging of oesophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bar-Shalom, Rachel; Frenkel, Alex [Rambam Medical Center, Department of Nuclear Medicine, Haifa (Israel); Guralnik, Ludmila; Leiderman, Max [Rambam Medical Center, Department of Diagnostic Imaging, Haifa (Israel); Tsalic, Medy [Rambam Medical Center, Department of Oncology, Haifa (Israel); Gaitini, Diana [Rambam Medical Center, Department of Diagnostic Imaging, Haifa (Israel); School of Medicine, Israel Institute of Technology, Haifa (Israel); Ben-Nun, Alon [Rambam Medical Center, Department of Thoracic Surgery, Haifa (Israel); Keidar, Zohar; Israel, Ora [Rambam Medical Center, Department of Nuclear Medicine, Haifa (Israel); School of Medicine, Israel Institute of Technology, Haifa (Israel)

    2005-08-01

    The aim of this study was to assess the value of combined PET/CT compared with PET reviewed side-by-side with CT, in patients with oesophageal cancer, before and after surgery. Forty-one FDG PET/CT studies were performed in 32 patients with oesophageal cancer, before surgery (n=18) or during follow-up after resection of the primary tumour (n=23). One hundred and fifteen sites suspicious for malignancy were evaluated. PET/CT was prospectively compared with PET reviewed side-by-side with CT, for detection, accurate localisation and characterisation of malignant sites. PET/CT performance in different anatomical regions was compared before and after surgery. The impact of fused data on patient management was retrospectively assessed. PET/CT had an incremental value over PET for interpretation of 25 of 115 sites (22%), changing the initial characterisation of ten sites to either malignant (n=1) or benign (n=9), and defining the precise anatomical location of 15 sites. PET/CT provided better specificity and accuracy than PET for detecting sites of oesophageal cancer (81% and 90% vs 59% and 83% respectively, p<0.01). Fusion was of special value for interpretation of cervical and abdomino-pelvic sites, for disease assessment in loco-regional lymph nodes before surgery and in regions of postoperative anatomical distortion. PET/CT had an impact on the further management of four patients (10%), by detecting nodal metastases that warranted disease upstaging (n=2) and by excluding disease in sites of benign uptake after surgery (n=2). (orig.)

  14. Development of (F-18)-Labeled Amyloid Imaging Agents for PET

    International Nuclear Information System (INIS)

    The applicant proposes to design and synthesize a series of fluorine-18-labeled radiopharmaceuticals to be used as amyloid imaging agents for positron emission tomography (PET). The investigators will conduct comprehensive iterative in vitro and in vivo studies based upon well defined acceptance criteria in order to identify lead agents suitable for human studies. The long term goals are to apply the selected radiotracers as potential diagnostic agents of Alzheimer's disease (AD), as surrogate markers of amyloid in the brain to determine the efficacy of anti-amyloid therapeutic drugs, and as tools to help address basic scientific questions regarding the progression of the neuropathology of AD, such as testing the 'amyloid cascade hypothesis' which holds that amyloid accumulation is the primary cause of AD.

  15. Performance simulation of a MRPC-based PET Imaging System

    CERN Document Server

    Banerjee, A

    2011-01-01

    The low cost and high resolution gas-based Multi-gap Resistive Plate Chamber (MRPC) opens a new possibility to find an efficient alternative detector for Time of Flight (TOF) based Positron Emission Tomography, where the sensitivity of the system depends largely on the time resolution of the detector. Suitable converters can be used to increase the efficiency of detection of photons from annihilation. In this work, we perform a detailed GEANT4 simulation to optimize the converter thickness thereby improving the efficiency of photon conversion. Also we have developed a Monte Carlo based simulation of MRPC response thereby obtaining the intrinsic time resolution of the detector, making it possible to simulate the final response of MRPC-based systems for PET imaging. The result of the cosmic ray test of a four-gap Bakelite-based MRPC operating in streamer mode is discussed.

  16. Development of [F-18]-Labeled Amyloid Imaging Agents for PET

    Energy Technology Data Exchange (ETDEWEB)

    Mathis, CA

    2007-05-09

    The applicant proposes to design and synthesize a series of fluorine-18-labeled radiopharmaceuticals to be used as amyloid imaging agents for positron emission tomography (PET). The investigators will conduct comprehensive iterative in vitro and in vivo studies based upon well defined acceptance criteria in order to identify lead agents suitable for human studies. The long term goals are to apply the selected radiotracers as potential diagnostic agents of Alzheimer's disease (AD), as surrogate markers of amyloid in the brain to determine the efficacy of anti-amyloid therapeutic drugs, and as tools to help address basic scientific questions regarding the progression of the neuropathology of AD, such as testing the "amyloid cascade hypothesis" which holds that amyloid accumulation is the primary cause of AD.

  17. A COMPARISON OF MRI AND PET IMAGES FUSION BASED ON YCBCR AND IHS COLOR SPACES

    OpenAIRE

    Ehsan Jalili; Sabalan Daneshvar

    2014-01-01

    Image fusion is a process in which two or more images from different sources or of various states are merged to create a single image in order to increase desired information of the images, decrease ambiguity, and eliminate repeated information. Fusion of high spatial resolution images such as MRI image with high spectral resolution images such as PET image is a case in point. A proper fusion technique adds spatial information to the final image without obliterating spectral information. Amon...

  18. Assessment of oxidative metabolism in Brown Fat using PET imaging

    Directory of Open Access Journals (Sweden)

    Otto eMuzik

    2012-02-01

    Full Text Available Objective: Although it has been believed that brown adipose tissue (BAT depots disappear shortly after the perinatal period in humans, PET imaging using the glucose analog FDG has shown unequivocally the existence of functional BAT in humans. The objective of this study was to determine, using dynamic oxygen-15 (15O PET imaging, to what extent BAT thermogenesis is activated in adults during cold stress and to establish the relationship between BAT oxidative metabolism and FDG tracer uptake.Methods: Fourteen adult normal subjects (9F/5M, 30+7 years underwent triple oxygen scans (H215O, C15O, 15O2 as well as indirect calorimetric measurements at rest and following exposure to mild cold (60F. Subjects were divided into two groups (BAT+ and BAT- based on the presence or absence of FDG tracer uptake (SUV > 2 in supraclavicular BAT. Blood flow (BF and oxygen extraction fraction (OEF was calculated from dynamic PET scans at the location of BAT, muscle and white adipose tissue (WAT. The metabolic rate of oxygen (MRO2 in BAT was determined and used to calculate the contribution of activated BAT to daily energy expenditure (DEE.Results: The median mass of activated BAT in the BAT+ group (5F, 31+8yrs was 52.4 g (14-68g and was 1.7 g (0-6.3g in the BAT- group (5M/4F, 29+6yrs. SUV values were significantly higher in the BAT+ as compared to the BAT- group (7.4+3.7 vs 1.9+0.9; p=0.03. BF values in BAT were significantly higher in the BAT+ as compared to the BAT- group (13.1+4.4 vs 5.7+1.1 ml/100g/min, p=0.03, but were similar in WAT (4.1+1.6 vs 4.2+1.8 ml/100g/min and muscle (3.7+0.8 vs 3.3+1.2 ml/100g/min. Calculated MRO2 values in BAT increased from 0.95+0.74 to 1.62+0.82 ml/100g/min in the BAT+ group and were significantly higher than those determined in the BAT- group (0.43+0.27 vs 0.56+0.24; p=0.67. The DEE associated with BAT oxidative metabolism was highly variable in the BAT+ group, with an average of 5.5+6.4 kcal/day (range 0.57–15.3 kcal/day.

  19. 21 CFR 570.14 - Indirect food additives resulting from packaging materials for animal feed and pet food.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Indirect food additives resulting from packaging materials for animal feed and pet food. 570.14 Section 570.14 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD...

  20. Monte Carlo modelling of singles-mode transmission data for small animal PET scanners

    International Nuclear Information System (INIS)

    The attenuation corrections factors (ACFs), which are necessary for quantitatively accurate PET imaging, can be obtained using singles-mode transmission scanning. However, contamination from scatter is a largely unresolved problem for these data. We present an extension of the Monte Carlo simulation tool, GATE, for singles-mode transmission data and its validation using experimental data from the microPET R4 and Focus 120 scanners. We first validated our simulated PET scanner for coincidence-mode data where we found that experimental resolution and scatter fractions (SFs) agreed well for simulations that included positron interactions and scatter in the source material. After modifying GATE to model singles-mode data, we compared simulated and experimental ACFs and SFs for three different sized water cylinders using 57Co (122 keV photon emitter) and 68Ge (positron emitter) transmission sources. We also propose a simple correction for a large background contamination we identified in the 68Ge singles-mode data due to intrinsic 176Lu radioactivity present in the detector crystals. For simulation data, the SFs agreed to within 1.5% and 2.5% of experimental values for background-corrected 68Ge and 57Co transmission data, respectively. This new simulation tool accurately models the photon interactions and data acquisition for singles-mode transmission scans

  1. Strategies for improving the Voxel-based statistical analysis for animal PET studies: assessment of cerebral glucose metabolism in cat deafness model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Kang, Hye Jin; Im, Ki Chun; Moon, Dae Hyuk; Lim, Sang Moo; Oh, Seung Ha; Lee, Dong Soo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    In imaging studies of the human brain, voxel-based statistical analysis method was widely used, since these methods were originally developed for the analysis of the human brain data, they are not optimal for the animal brain data. The aim of this study is to optimize the procedures for the 3D voxel-based statistical analysis of cat FDG PET brain images. A microPET Focus 120 scanner was used. Eight cats underwent FDG PET scans twice before and after inducing the deafness. Only the brain and adjacent regions were extracted from each data set by manual masking. Individual PET image at normal and deaf state was realigned to each other to remove the confounding effects by the different spatial normalization parameters on the results of statistical analyses. Distance between the sampling points on the reference image and kernel size of Gaussian filter applied to the images before estimating the realignment parameters were adjusted to 0.5 mm and 2 mm. Both data was then spatial normalized onto study-specific cat brain template. Spatially normalized PET data were smoothed and voxel-based paired t-test was performed. Cerebral glucose metabolism decreased significantly after the loss of hearing capability in parietal lobes, postcentral gyri, STG, MTG, lTG, and IC at both hemisphere and left SC (FDR corrected P < 0.05, k=50). Cerebral glucose metabolism in deaf cats was found to be significantly higher than in controls in the right cingulate (FDR corrected P < 0.05, k=50). The ROI analysis also showed significant reduction of glucose metabolism in the same areas as in the SPM analysis, except for some regions (P < 0.05). Method for the voxel-based analysis of cat brain PET data was optimized for analysis of cat brain PET. This result was also confirmed by ROI analysis. The results obtained demonstrated the high localization accuracy and specificity of the developed method, and were found to be useful for examining cerebral glucose metabolism in a cat cortical deafness model.

  2. 3D Surface Realignment Tracking for Medical Imaging: A Phantom Study with PET Motion Correction

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Paulsen, Rasmus Reinhold; Jensen, Rasmus Ramsbøl;

    2011-01-01

    We present a complete system for motion correction in high resolution brain positron emission tomography (PET) imaging. It is based on a compact structured light scanner mounted above the patient tunnel of the Siemens High Resolution Research Tomograph PET brain scanner. The structured light syst...

  3. Generalized whole-body Patlak parametric imaging for enhanced quantification in clinical PET

    NARCIS (Netherlands)

    Karakatsanis, Nicolas A.; Zhou, Yun; Lodge, Martin A.; Casey, Michael E.; Wahl, Richard L.; Zaidi, Habib; Rahmim, Arman

    2015-01-01

    We recently developed a dynamic multi-bed PET data acquisition framework to translate the quantitative benefits of Patlak voxel-wise analysis to the domain of routine clinical whole-body (WB) imaging. The standard Patlak (sPatlak) linear graphical analysis assumes irreversible PET tracer uptake, ign

  4. Comparative methods for PET image segmentation in pharyngolaryngeal squamous cell carcinoma

    NARCIS (Netherlands)

    Zaidi, Habib; Abdoli, Mehrsima; Fuentes, Carolina Llina; El Naqa, Issam M.

    2012-01-01

    Several methods have been proposed for the segmentation of F-18-FDG uptake in PET. In this study, we assessed the performance of four categories of F-18-FDG PET image segmentation techniques in pharyngolaryngeal squamous cell carcinoma using clinical studies where the surgical specimen served as the

  5. Current imaging techniques in rheumatology: MRI, scintigraphy and PET

    International Nuclear Information System (INIS)

    The first-line imaging technique for diagnosis inflammation in musculo-skeletal organs in rheumatoid arthritis (RA) is planar X-ray examination, which was for many years the first and the only single tool for RA diagnostics and response evaluation. Today, in the era of more aggressive RA treatment, ultrasound examination (US) and magnetic resonance imaging (MRI) are also frequently used. US is used to detect early signs of inflammation within the soft tissue. MRI allows to assess the soft tissue and bone marrow involvement in case of inflammation and/or infection. MRI is capable of detecting more inflammatory lesions and erosions than US, X-ray, or CT. Standard scintigraphy plays a crucial role, and data from positron emission tomography (PET) are also promising. These functional imaging techniques are used in detection of inflammation and/or infection in case of ambiguous results being obtained by other techniques or at other clinics. In patients with RA, scintigraphy plays a key role in the differential diagnosis of hip, knee, etc. endoprosthesis disorders, including mechanical or septic loosening

  6. Influence of Arm Movement on Lesion Detection in PET/CT Imaging: Case Report

    Directory of Open Access Journals (Sweden)

    Yasemin Parlak

    2015-06-01

    Full Text Available Arm movement after the CT scan is a common artifact in PET/CT scanning. Motion artifacts may lead to difficulties in interpreting PET/CT images accurately. We report a 66 year old male patient with gastric cancer who underwent PET/CT for primary staging. He had a previous history of papillary thyroid cancer. In PET scan, there were striking cold artifacts at the level of arms. This is a classical sign of an accidental arm motion. A second scan was performed with the arms down due to the history of papillary thyroid cancer. The results were discussed.

  7. Influence of Arm Movement on Lesion Detection in PET/CT Imaging: Case Report

    OpenAIRE

    Yasemin Parlak; Gozde Mutevelizade; Gul Gumuser

    2015-01-01

    Arm movement after the CT scan is a common artifact in PET/CT scanning. Motion artifacts may lead to difficulties in interpreting PET/CT images accurately. We report a 66 year old male patient with gastric cancer who underwent PET/CT for primary staging. He had a previous history of papillary thyroid cancer. In PET scan, there were striking cold artifacts at the level of arms. This is a classical sign of an accidental arm motion. A second scan was performed with the arms down due to ...

  8. Impact of metal artefacts due to EEG electrodes in brain PET/CT imaging

    International Nuclear Information System (INIS)

    The goal of this study is to investigate the impact of electroencephalogram (EEG) electrodes on the visual quality and quantification of 18F-FDG PET images in neurological PET/CT examinations. For this purpose, the scans of 20 epilepsy patients with EEG monitoring were used. The CT data were reconstructed with filtered backprojection (FBP) and with a metal artefact reduction (MAR) algorithm. Both data sets were used for CT-based attenuation correction (AC) of the PET data. Also, a calculated AC (CALC) technique was considered. A volume of interest (VOI)-based analysis and a voxel-based quantitative analysis were performed to compare the different AC methods. Images were also evaluated visually by two observers. It was shown with simulations and phantom measurements that from the considered AC methods, the MAR-AC can be used as the reference in this setting. The visual assessment of PET images showed local hot spots outside the brain corresponding to the locations of the electrodes when using FBP-AC. In the brain, no abnormalities were observed. The quantitative analysis showed a very good correlation between PET-FBP-AC and PET-MAR-AC, with a statistically significant positive bias in the PET-FBP-AC images of about 5-7% in most brain voxels. There was also good correlation between PET-CALC-AC and PET-MAR-AC, but in the PET-CALC-AC images, regions with both a significant positive and negative bias were observed. EEG electrodes give rise to local hot spots outside the brain and a positive quantification bias in the brain. However, when diagnosis is made by mere visual assessment, the presence of EEG electrodes does not seem to alter the diagnosis. When quantification is performed, the bias becomes an issue especially when comparing brain images with and without EEG monitoring

  9. Symposium on Housing and Diseases of Rabbits, furbearing animals and pet animals

    NARCIS (Netherlands)

    Rommers, J.M.; Jong, de I.C.; Greef, de K.H.

    2015-01-01

    Within the Welfare Quality® project protocols have been developed to assess animal welfare on-farm in an objective, science based and practically applicable way. For various species like broilers and laying hens, sows and growing pigs, dairy cattle and veal calves, welfare assessment protocols have

  10. Fully 3D PET image reconstruction with a 4D sinogram blurring kernel

    Energy Technology Data Exchange (ETDEWEB)

    Tohme, Michel S.; Qi, Jinyi [California Univ., Davis, CA (United States). Dept. of Biomedical Engineering; Zhou, Jian

    2011-07-01

    Accurately modeling PET system response is essential for high-resolution image reconstruction. Traditionally, sinogram blurring effects are modeled as a 2D blur in each sinogram plane. Such 2D blurring kernel is insufficient for fully 3D PET data, which has four dimensions. In this paper, we implement a fully 3D PET image reconstruction using a 4D sinogram blurring kernel estimated from point source scans and perform phantom experiments to evaluate the improvements in image quality over methods with existing 2D blurring kernels. The results show that the proposed reconstruction method can achieve better spatial resolution and contrast recovery than existing methods. (orig.)

  11. Automated interpretation of PET/CT images in patients with lung cancer

    DEFF Research Database (Denmark)

    Gutte, Henrik; Jakobsson, David; Olofsson, Fredrik;

    2007-01-01

    cancer. METHODS: A total of 87 patients who underwent PET/CT examinations due to suspected lung cancer comprised the training group. The test group consisted of PET/CT images from 49 patients suspected with lung cancer. The consensus interpretations by two experienced physicians were used as the 'gold...... for localization of lesions in the PET images in the feature extraction process. Eight features from each examination were used as inputs to artificial neural networks trained to classify the images. Thereafter, the performance of the network was evaluated in the test set. RESULTS: The performance of the automated...

  12. Rare Thyroid Cartilage and Diaphragm Metastases from Lung Cancer Visualized on F-18 FDG-PET/CT Imaging

    Directory of Open Access Journals (Sweden)

    Pelin Özcan Kara

    2011-08-01

    Full Text Available Positron emission tomography (PET with F-18 fluorodeoxyglucose (FDG has evolved as a useful imaging modality in the assessment of a variety of cancers, especially for tumor staging and post treatment monitoring. It provides metabolic information. Although, when used alone, relative lack of anatomic landmarks, is a major limitation of PET imaging, this limitation of PET imaging is overcome by the availability of integrated PET/CT imaging. PET and CT images are acquired in one procedure, yielding fused anatomical and functional data sets. Studies with integrated PET/CT imaging have shown promising results. In this case, we present an interesting integrated PET/CT imaging in a lung cancer patient with rare, diaphragm and thyroid cartilage metastases. (MIRT 2011;20:70-72

  13. Transmission imaging for integrated PET-MR systems

    Science.gov (United States)

    Bowen, Spencer L.; Fuin, Niccolò; Levine, Michael A.; Catana, Ciprian

    2016-08-01

    Attenuation correction for PET-MR systems continues to be a challenging problem, particularly for body regions outside the head. The simultaneous acquisition of transmission scan based μ-maps and MR images on integrated PET-MR systems may significantly increase the performance of and offer validation for new MR-based μ-map algorithms. For the Biograph mMR (Siemens Healthcare), however, use of conventional transmission schemes is not practical as the patient table and relatively small diameter scanner bore significantly restrict radioactive source motion and limit source placement. We propose a method for emission-free coincidence transmission imaging on the Biograph mMR. The intended application is not for routine subject imaging, but rather to improve and validate MR-based μ-map algorithms; particularly for patient implant and scanner hardware attenuation correction. In this study we optimized source geometry and assessed the method’s performance with Monte Carlo simulations and phantom scans. We utilized a Bayesian reconstruction algorithm, which directly generates μ-map estimates from multiple bed positions, combined with a robust scatter correction method. For simulations with a pelvis phantom a single torus produced peak noise equivalent count rates (34.8 kcps) dramatically larger than a full axial length ring (11.32 kcps) and conventional rotating source configurations. Bias in reconstructed μ-maps for head and pelvis simulations was  ⩽4% for soft tissue and  ⩽11% for bone ROIs. An implementation of the single torus source was filled with 18F-fluorodeoxyglucose and the proposed method quantified for several test cases alone or in comparison with CT-derived μ-maps. A volume average of 0.095 cm-1 was recorded for an experimental uniform cylinder phantom scan, while a bias of  <2% was measured for the cortical bone equivalent insert of the multi-compartment phantom. Single torus μ-maps of a hip implant phantom showed significantly less

  14. ImmunoPET imaging of phosphatidylserine in pro-apoptotic therapy treated tumor models

    International Nuclear Information System (INIS)

    An immunoPET imaging probe for the detection of phosphatidylserine was developed and tested in animal models of human cancer treated with pro-apoptotic therapy. We hypothesized that the relatively long plasma half-life of a probe based on a full-length antibody coupled with a residualizing radionuclide would be able to catch the wave of drug-induced apoptosis and lead to a specific accumulation in apoptotic tumor tissue. Methods: The imaging probe is based on a 89Zr-labeled monoclonal antibody PGN635 targeting phosphatidylserine. The probe was evaluated pre-clinically in four tumor xenograft models: one studied treatment with paclitaxel to trigger the intrinsic apoptotic pathway, and three others interrogated treatment with an agonistic death-receptor monoclonal antibody to engage the extrinsic apoptotic pathway. Results: High accumulation of 89Zr-PGN635 was observed in treated tumors undergoing apoptosis reaching 30 %ID/g and tumor-to-blood ratios up to 13. The tumor uptake in control groups treated with vehicle or imaged with a non-binding antibody probe was significantly lower. Conclusions: The results demonstrate the ability of 89Zr-PGN635 to image drug-induced apoptosis in animal models and corroborate our hypothesis that radiolabeled antibodies binding to intracellular targets transiently exposed on the cell surface during apoptosis can be employed for detection of tumor response to therapy.

  15. A New F-18 Labeled PET Agent For Imaging Alzheimer's Plaques

    International Nuclear Information System (INIS)

    Amyloid plaques and neurofibrillary tangles are hallmarks of Alzheimer's disease (AD). Advances in development of imaging agents have focused on targeting amyloid plaques. Notable success has been the development of C-11 labeled PIB (Pittsburgh Compound) and a number of studies have demonstrated the utility of this agent. However, the short half life of C-11 (t1/2: 20 min), is a limitation, thus has prompted the development of F-18 labeled agents. Most of these agents are derivatives of amyloid binding dyes; Congo red and Thioflavin. Some of these agents are in clinical trials with encouraging results. We have been exploring new class of agents based on 8-hydroxy quinoline, a weak metal chelator, targeting elevated levels of metals in plaques. Iodine-123 labeled clioquinol showed affinity for amyloid plaques however, it had limited brain uptake and was not successful in imaging in intact animals and humans. We have been successful in synthesizing F-18 labeled 8-hydroxy quinoline. Small animal PET/CT imaging studies with this agent showed high (7-10% ID/g), rapid brain uptake and fast washout of the agent from normal mice brains and delayed washout from transgenic Alzheimer's mice. These promising results encouraged us in further evaluation of this class of compounds for imaging AD plaques.

  16. FDG PET/MRI Imaging of an Angiosarcoma in a Popliteal Aneurysm and Tibial Head After Popliteal Graft.

    Science.gov (United States)

    Bader, Thomas; Strobel, Klaus; Egger-Sigg, Michèle; Diebold, Joachim; Beck, Martin

    2016-09-01

    Angiosarcomas are rare aggressive neoplasms with a wide variety of anatomic locations, one third of them presenting multifocal. Molecular imaging with PET/CT and PET/MR plays an emerging role in staging sarcomas. This case demonstrates the value of PET/MR imaging of an angiosarcoma with involvement of the tibial head and a popliteal aneurysm with histopathologic correlation. PMID:27405038

  17. Evaluation of animal control measures on pet demographics in Santa Clara County, California, 1993-2006.

    Science.gov (United States)

    Kass, Philip H; Johnson, Karen L; Weng, Hsin-Yi

    2013-01-01

    The measurable benefits of animal control programs are unknown and the aim of this study was to determine the impact of these programs on pet population changes. A prospective cross-sectional study of 1000 households was implemented in 2005 to evaluate characteristics of the owned and unowned population of dogs and cats in Santa Clara County, California. The same population was previously studied 12 years earlier. During this time period, the county instituted in 1994 and then subsequently disestablished a municipal spay/neuter voucher program for cats. Dog intakes declined from 1992-2005, as they similarly did for an adjacent county (San Mateo). However, cat intakes declined significantly more in Santa Clara County than San Mateo, with an average annual decline of approximately 700 cats for the 12 year period. Time series analysis showed a greater than expected decline in the number of cats surrendered to shelters in Santa Clara County during the years the voucher program was in effect (1994-2005). The net savings to the county by reducing the number of cat shelter intakes was estimated at approximately $1.5 million. The measurable benefits of animal control programs are unknown and the aim of this study was to determine the impact of these programs on pet population changes.

  18. Evaluation of animal control measures on pet demographics in Santa Clara County, California, 1993–2006

    Directory of Open Access Journals (Sweden)

    Philip H. Kass

    2013-02-01

    Full Text Available The measurable benefits of animal control programs are unknown and the aim of this study was to determine the impact of these programs on pet population changes. A prospective cross-sectional study of 1000 households was implemented in 2005 to evaluate characteristics of the owned and unowned population of dogs and cats in Santa Clara County, California. The same population was previously studied 12 years earlier. During this time period, the county instituted in 1994 and then subsequently disestablished a municipal spay/neuter voucher program for cats. Dog intakes declined from 1992–2005, as they similarly did for an adjacent county (San Mateo. However, cat intakes declined significantly more in Santa Clara County than San Mateo, with an average annual decline of approximately 700 cats for the 12 year period. Time series analysis showed a greater than expected decline in the number of cats surrendered to shelters in Santa Clara County during the years the voucher program was in effect (1994–2005. The net savings to the county by reducing the number of cat shelter intakes was estimated at approximately $1.5 million. The measurable benefits of animal control programs are unknown and the aim of this study was to determine the impact of these programs on pet population changes.

  19. Radiofluorinated rhenium cyclized α-MSH analogues for PET imaging of melanocortin receptor 1.

    Science.gov (United States)

    Ren, Gang; Liu, Shuanlong; Liu, Hongguang; Miao, Zheng; Cheng, Zhen

    2010-12-15

    In order to accomplish in vivo molecular imaging of melanoma biomarker melanocortin 1 receptor (MC1R), several α-melanocyte-stimulating hormone (α-MSH) analogues have been labeled with N-succinimidyl-4-¹⁸F-fluorobenzoate (¹⁸)F-SFB) and studied as positron emission tomography (PET) probes in our recent studies. To further pursue a radiofluorinated α-MSH peptide with high clinical translation potential, we utilized 4-nitrophenyl 2-¹⁸F-fluoropropionate (¹⁸F-NFP) to radiofluorinate the transition metal rhenium cyclized α-MSH metallopeptides for PET imaging of MC1R positive malignant melanoma. Metallopeptides Ac-d,Lys-ReCCMSH(Arg¹¹) (two isomers, namely RMSH-1 and RMSH-2) were synthesized using conventional solid phase peptide synthesis chemistry and rhenium cyclization reaction. The two isomers were then conjugated with ¹⁹F-NFP or ¹⁸F-NFP. The resulting cold or radiofluorinated metallopeptides, (¹⁸/¹⁹)F-FP-RMSH-1 and (¹⁸/¹⁹)F-FP-RMSH-2, were further evaluated for their in vitro receptor binding affinities, in vivo biodistribution, and small-animal PET imaging properties. The binding affinities of ¹⁹F-FP-RMSH-1 and ¹⁹F-FP-RMSH-2 were determined to be within low nanomolar range. In vivo studies revealed that both F-labeled metallopeptides possessed good tumor uptake in the B16F10 murine model with high MC1R expression, while possessing much lower uptake in A375M human melanoma xenografts. Moreover, ¹⁸F-FP-RMSH-1 displayed more favorable in vivo performance in terms of higher tumor uptake and much lower accumulation in the kidney and liver, when compared to that of ¹⁸F-FP-RMSH-2 at 2 h postinjection (p.i.). ¹⁸F-FP-RMSH-1 also displayed lower liver and lung uptake when compared with that of the same peptide labeled with ¹⁸F-SFB (named as ¹⁸F-FB-RMSH-1). Small animal PET imaging of ¹⁸F-FP-RMSH-1 in mice bearing B16F10 tumors at 1 and 2 h showed good tumor imaging quality. As expected, much lower tumor uptake and

  20. Motion correction in simultaneous PET/MR brain imaging using sparsely sampled MR navigators

    DEFF Research Database (Denmark)

    Keller, Sune H; Hansen, Casper; Hansen, Christian;

    2015-01-01

    BACKGROUND: We present a study performing motion correction (MC) of PET using MR navigators sampled between other protocolled MR sequences during simultaneous PET/MR brain scanning with the purpose of evaluating its clinical feasibility and the potential improvement of image quality. FINDINGS......: Twenty-nine human subjects had a 30-min [(11)C]-PiB PET scan with simultaneous MR including 3D navigators sampled at six time points, which were used to correct the PET image for rigid head motion. Five subjects with motion greater than 4 mm were reconstructed into six frames (one for each navigator......) which were averaged to one image after MC. The average maximum motion magnitude observed was 3.9 ± 2.4 mm (1 to 11 mm). Visual evaluation by a nuclear medicine physician of the five subjects' motion corrected rated three of the five images blurred before motion correction, while no images were rated...

  1. Initial studies using the RatCAP conscious animal PET tomograph

    Energy Technology Data Exchange (ETDEWEB)

    Woody, C. [Brookhaven National Laboratory, Upton, NY (United States)]. E-mail: woody@bnl.gov; Vaska, P. [Brookhaven National Laboratory, Upton, NY (United States); Schlyer, D. [Brookhaven National Laboratory, Upton, NY (United States); Pratte, J.-F. [Brookhaven National Laboratory, Upton, NY (United States); Junnarkar, S. [Brookhaven National Laboratory, Upton, NY (United States); Park, S.-J. [Brookhaven National Laboratory, Upton, NY (United States); Stoll, S. [Brookhaven National Laboratory, Upton, NY (United States); Purschke, M. [Brookhaven National Laboratory, Upton, NY (United States); Southekal, S. [Stony Brook University, Stony Brook, NY (United States); Kriplani, A. [Stony Brook University, Stony Brook, NY (United States); Krishnamoorthy, S. [Stony Brook University, Stony Brook, NY (United States); Maramraju, S. [Stony Brook University, Stony Brook, NY (United States); Lee, D. [Brookhaven National Laboratory, Upton, NY (United States); Schiffer, W. [Brookhaven National Laboratory, Upton, NY (United States); Dewey, S. [Brookhaven National Laboratory, Upton, NY (United States); Neill, J. [Long Island University, Brookville, NY (United States); Kandasamy, A. [Brookhaven National Laboratory, Upton, NY (United States); O' Connor, P. [Brookhaven National Laboratory, Upton, NY (United States); Radeka, V. [Brookhaven National Laboratory, Upton, NY (United States); Fontaine, R. [Sherbrooke University, Sherbrooke, Que. (Canada); Lecomte, R. [Sherbrooke University, Sherbrooke, Que. (Canada)

    2007-02-01

    The RatCAP is a small, head-mounted PET tomograph designed to image the brain of a conscious rat without the use of anesthesia. The detector is a complete, high-performance 3D tomograph consisting of a 3.8 cm inside-diameter ring containing 12 block detectors, each of which is comprised of a 4x8 array of 2.2x2.2x5 mm{sup 3} LSO crystals readout with a matching APD array and custom ASIC, and has a 1.8 cm axial field of view. Construction of the first working prototype detector has been completed and its performance characteristics have been measured. The results show an intrinsic spatial resolution of 2.1 mm, a time resolution of {approx}14 ns FWHM, and a sensitivity of 0.7% at an energy threshold of 150 keV. First preliminary images have been obtained using {sup 18}F-FDG and {sup 11}C-methamphetamine, which show comparable image quality to those obtained from a commercial MicroPET R4 scanner. Initial studies have also been carried out to study stress levels in rats wearing the RatCAP.

  2. Initial studies using the RatCAP conscious animal PET tomograph

    Science.gov (United States)

    Woody, C.; Vaska, P.; Schlyer, D.; Pratte, J.-F.; Junnarkar, S.; Park, S.-J.; Stoll, S.; Purschke, M.; Southekal, S.; Kriplani, A.; Krishnamoorthy, S.; Maramraju, S.; Lee, D.; Schiffer, W.; Dewey, S.; Neill, J.; Kandasamy, A.; O'Connor, P.; Radeka, V.; Fontaine, R.; Lecomte, R.

    2007-02-01

    The RatCAP is a small, head-mounted PET tomograph designed to image the brain of a conscious rat without the use of anesthesia. The detector is a complete, high-performance 3D tomograph consisting of a 3.8 cm inside-diameter ring containing 12 block detectors, each of which is comprised of a 4×8 array of 2.2×2.2×5 mm 3 LSO crystals readout with a matching APD array and custom ASIC, and has a 1.8 cm axial field of view. Construction of the first working prototype detector has been completed and its performance characteristics have been measured. The results show an intrinsic spatial resolution of 2.1 mm, a time resolution of ˜14 ns FWHM, and a sensitivity of 0.7% at an energy threshold of 150 keV. First preliminary images have been obtained using 18F-FDG and 11C-methamphetamine, which show comparable image quality to those obtained from a commercial MicroPET R4 scanner. Initial studies have also been carried out to study stress levels in rats wearing the RatCAP.

  3. [F18]-FDG imaging of experimental animal tumours using a hybrid gamma-camera

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) has been widely used in clinical studies. This technology permits detection of compounds labelled with positron emitting radionuclides and in particular, [F18]-fluorodeoxyglucose ([F18]-FDG).[F18]-FDG uptake and accumulation is generally related to malignancy; some recent works have suggested the usefulness of PET camera dedicated to small laboratory animals (micro-PET). Our study dealt with the feasibility of [F18]-FDG imaging of malignant tumours in animal models by means of an hybrid camera dedicated for human scintigraphy. We evaluated the ability of coincidence detection emission tomography (CDET) using this hybrid camera to visualize in vivo subcutaneous tumours grafted to mice or rats. P815 murine mastocytoma grafted in syngeneic DBA/2 mice resulted with foci of very high FDG uptake. Tumours with a diameter of only 3 mm were clearly visualized. Medullary thyroid cancer provoked by rMTC 6/23 and CA77 lines in syngeneic Wag/Rij rat was also detected. The differentiated CA77 tumours exhibited avidity for [F18]-FDG and a tumour, which was just palpable (diameter lower than 2 mm), was identified. In conclusion, CDET-FDG is a non-invasive imaging tool which can be used to follow grafted tumours in the small laboratory animal, even when their size is smaller than 1 cm. It has the potential to evaluate experimental anticancer treatments in small series of animals by individual follow-up. It offers the opportunity to develop experimental PET research within a nuclear medicine or biophysics department, the shift to a dedicated micro-PET device being subsequently necessary. It is indeed compulsory to strictly follow the rules for non contamination and disinfection of the hybrid camera. (authors)

  4. 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.

  5. Restoration of the analytically reconstructed OpenPET images by the method of convex projections

    Energy Technology Data Exchange (ETDEWEB)

    Tashima, Hideaki; Murayama, Hideo; Yamaya, Taiga [National Institute of Radiological Sciences, Chiba (Japan); Katsunuma, Takayuki; Suga, Mikio [Chiba Univ. (Japan). Graduate School of Engineering; Kinouchi, Shoko [National Institute of Radiological Sciences, Chiba (Japan); Chiba Univ. (Japan). Graduate School of Engineering; Obi, Takashi [Tokyo Institute of Technology (Japan). Interdisciplinary Graduate School of Science and Engineering; Kudo, Hiroyuki [Tsukuba Univ. (Japan). Graduate School of Systems and Information Engineering

    2011-07-01

    We have proposed the OpenPET geometry which has gaps between detector rings and physically opened field-of-view. The image reconstruction of the OpenPET is classified into an incomplete problem because it does not satisfy the Orlov's condition. Even so, the simulation and experimental studies have shown that applying iterative methods such as the maximum likelihood expectation maximization (ML-EM) algorithm successfully reconstruct images in the gap area. However, the imaging process of the iterative methods in the OpenPET imaging is not clear. Therefore, the aim of this study is to analytically analyze the OpenPET imaging and estimate implicit constraints involved in the iterative methods. To apply explicit constraints in the OpenPET imaging, we used the method of convex projections for restoration of the images reconstructed by the analytical way in which low-frequency components are lost. Numerical simulations showed that the similar restoration effects are involved both in the ML-EM and the method of convex projections. Therefore, the iterative methods have advantageous effect of restoring lost frequency components of the OpenPET imaging. (orig.)

  6. Respiratory motion correction in 4D-PET by simultaneous motion estimation and image reconstruction (SMEIR)

    Science.gov (United States)

    Kalantari, Faraz; Li, Tianfang; Jin, Mingwu; Wang, Jing

    2016-08-01

    In conventional 4D positron emission tomography (4D-PET), images from different frames are reconstructed individually and aligned by registration methods. Two issues that arise with this approach are as follows: (1) the reconstruction algorithms do not make full use of projection statistics; and (2) the registration between noisy images can result in poor alignment. In this study, we investigated the use of simultaneous motion estimation and image reconstruction (SMEIR) methods for motion estimation/correction in 4D-PET. A modified ordered-subset expectation maximization algorithm coupled with total variation minimization (OSEM-TV) was used to obtain a primary motion-compensated PET (pmc-PET) from all projection data, using Demons derived deformation vector fields (DVFs) as initial motion vectors. A motion model update was performed to obtain an optimal set of DVFs in the pmc-PET and other phases, by matching the forward projection of the deformed pmc-PET with measured projections from other phases. The OSEM-TV image reconstruction was repeated using updated DVFs, and new DVFs were estimated based on updated images. A 4D-XCAT phantom with typical FDG biodistribution was generated to evaluate the performance of the SMEIR algorithm in lung and liver tumors with different contrasts and different diameters (10-40 mm). The image quality of the 4D-PET was greatly improved by the SMEIR algorithm. When all projections were used to reconstruct 3D-PET without motion compensation, motion blurring artifacts were present, leading up to 150% tumor size overestimation and significant quantitative errors, including 50% underestimation of tumor contrast and 59% underestimation of tumor uptake. Errors were reduced to less than 10% in most images by using the SMEIR algorithm, showing its potential in motion estimation/correction in 4D-PET.

  7. Respiratory motion correction in 4D-PET by simultaneous motion estimation and image reconstruction (SMEIR)

    Science.gov (United States)

    Kalantari, Faraz; Li, Tianfang; Jin, Mingwu; Wang, Jing

    2016-08-01

    In conventional 4D positron emission tomography (4D-PET), images from different frames are reconstructed individually and aligned by registration methods. Two issues that arise with this approach are as follows: (1) the reconstruction algorithms do not make full use of projection statistics; and (2) the registration between noisy images can result in poor alignment. In this study, we investigated the use of simultaneous motion estimation and image reconstruction (SMEIR) methods for motion estimation/correction in 4D-PET. A modified ordered-subset expectation maximization algorithm coupled with total variation minimization (OSEM-TV) was used to obtain a primary motion-compensated PET (pmc-PET) from all projection data, using Demons derived deformation vector fields (DVFs) as initial motion vectors. A motion model update was performed to obtain an optimal set of DVFs in the pmc-PET and other phases, by matching the forward projection of the deformed pmc-PET with measured projections from other phases. The OSEM-TV image reconstruction was repeated using updated DVFs, and new DVFs were estimated based on updated images. A 4D-XCAT phantom with typical FDG biodistribution was generated to evaluate the performance of the SMEIR algorithm in lung and liver tumors with different contrasts and different diameters (10–40 mm). The image quality of the 4D-PET was greatly improved by the SMEIR algorithm. When all projections were used to reconstruct 3D-PET without motion compensation, motion blurring artifacts were present, leading up to 150% tumor size overestimation and significant quantitative errors, including 50% underestimation of tumor contrast and 59% underestimation of tumor uptake. Errors were reduced to less than 10% in most images by using the SMEIR algorithm, showing its potential in motion estimation/correction in 4D-PET.

  8. [18F]desmethoxyfallypride as a novel PET radiotracer for quantitative in vivo dopamine D2/D3 receptor imaging in rat models of neurodegenerative diseases

    International Nuclear Information System (INIS)

    Introduction: [18F]desmethoxyfallypride ([18F]DMFP) is a promising tracer for longitudinal assessment of striatal dopamine D2/D3-receptor (D2R) availability by positron emission tomography (PET) in small animal models. We explored the feasibility of [18F]DMFP-PET to image D2R availability in rat models of Huntington's (HD) and Parkinson's disease (PD). Methods: Animals received either unilateral intrastriatal quinolinic acid lesions or medial forebrain bundle injections of 6-OHDA to produce the loss of striatal projection neurones or deplete the striatal dopamine, corresponding to established animal models for HD and PD, respectively. Three weeks after lesioning, PET scans were acquired on a microPET Focus 120 system following the tail vein injection of [18F]DMFP. Results: [18F]DMFP-PET clearly visualized lesion induced decreases and increases of D2R availability. In vivo estimates of D2R binding and changes thereof gained by pharmacokinetic analyses correlated significantly with D2R density and its change provided by in vitro [3H]raclopride-autoradiography. Conclusions: In conclusion, [18F]DMFP-PET is a suitable method for in vivo D2R-assessment in preclinical research, e.g for monitoring cell-based therapies.

  9. Noninvasive bioluminescence imaging in small animals.

    Science.gov (United States)

    Zinn, Kurt R; Chaudhuri, Tandra R; Szafran, April Adams; O'Quinn, Darrell; Weaver, Casey; Dugger, Kari; Lamar, Dale; Kesterson, Robert A; Wang, Xiangdong; Frank, Stuart J

    2008-01-01

    There has been a rapid growth of bioluminescence imaging applications in small animal models in recent years, propelled by the availability of instruments, analysis software, reagents, and creative approaches to apply the technology in molecular imaging. Advantages include the sensitivity of the technique as well as its efficiency, relatively low cost, and versatility. Bioluminescence imaging is accomplished by sensitive detection of light emitted following chemical reaction of the luciferase enzyme with its substrate. Most imaging systems provide 2-dimensional (2D) information in rodents, showing the locations and intensity of light emitted from the animal in pseudo-color scaling. A 3-dimensional (3D) capability for bioluminescence imaging is now available, but is more expensive and less efficient; other disadvantages include the requirement for genetically encoded luciferase, the injection of the substrate to enable light emission, and the dependence of light signal on tissue depth. All of these problems make it unlikely that the method will be extended to human studies. However, in small animal models, bioluminescence imaging is now routinely applied to serially detect the location and burden of xenografted tumors, or identify and measure the number of immune or stem cells after an adoptive transfer. Bioluminescence imaging also makes it possible to track the relative amounts and locations of bacteria, viruses, and other pathogens over time. Specialized applications of bioluminescence also follow tissue-specific luciferase expression in transgenic mice, and monitor biological processes such as signaling or protein interactions in real time. In summary, bioluminescence imaging has become an important component of biomedical research that will continue in the future.

  10. A Survey of FDG- and Amyloid-PET Imaging in Dementia and GRADE Analysis

    Directory of Open Access Journals (Sweden)

    Perani Daniela

    2014-01-01

    Full Text Available PET based tools can improve the early diagnosis of Alzheimer’s disease (AD and differential diagnosis of dementia. The importance of identifying individuals at risk of developing dementia among people with subjective cognitive complaints or mild cognitive impairment has clinical, social, and therapeutic implications. Within the two major classes of AD biomarkers currently identified, that is, markers of pathology and neurodegeneration, amyloid- and FDG-PET imaging represent decisive tools for their measurement. As a consequence, the PET tools have been recognized to be of crucial value in the recent guidelines for the early diagnosis of AD and other dementia conditions. The references based recommendations, however, include large PET imaging literature based on visual methods that greatly reduces sensitivity and specificity and lacks a clear cut-off between normal and pathological findings. PET imaging can be assessed using parametric or voxel-wise analyses by comparing the subject’s scan with a normative data set, significantly increasing the diagnostic accuracy. This paper is a survey of the relevant literature on FDG and amyloid-PET imaging aimed at providing the value of quantification for the early and differential diagnosis of AD. This allowed a meta-analysis and GRADE analysis revealing high values for PET imaging that might be useful in considering recommendations.

  11. 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.

  12. 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.

  13. Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    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

  14. Evolving role of FDG PET imaging in assessing joint disorders: a systematic review

    International Nuclear Information System (INIS)

    Assessing joint disorders has been a relatively recent and evolving application of 18F-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) imaging. FDG is taken up by inflammatory cells, particularly when they are active as part of an ongoing inflammatory process. Hence FDG PET has been employed to assess a wide array of arthritic disorders. FDG PET imaging has been investigated in various joint diseases for diagnostic purposes, treatment monitoring, and as a prognostic indicator as in other disorders. In some of the diseases the ancillary findings in FDG PET have provided important clues about the underlying pathophysiology and pathogenesis processes. While substantial promise has been demonstrated in a number of studies, it is clear that the potential utility of PET in this clinical realm far outweighs that which has been established to date. (orig.)

  15. Towards continualized task-based resolution modeling in PET imaging

    Science.gov (United States)

    Ashrafinia, Saeed; Karakatsanis, Nicolas; Mohy-ud-Din, Hassan; Rahmim, Arman

    2014-03-01

    We propose a generalized resolution modeling (RM) framework, including extensive task-based optimization, wherein we continualize the conventionally discrete framework of RM vs. no RM, to include varying degrees of RM. The proposed framework has the advantage of providing a trade-off between the enhanced contrast recovery by RM and the reduced inter-voxel correlations in the absence of RM, and to enable improved task performance. The investigated context was that of oncologic lung FDG PET imaging. Given a realistic blurring kernel of FWHM h (`true PSF'), we performed iterative EM including RM using a wide range of `modeled PSF' kernels with varying widths h. In our simulations, h = 6mm, while h varied from 0 (no RM) to 12mm, thus considering both underestimation and overestimation of the true PSF. Detection task performance was performed using prewhitened (PWMF) and nonprewhitened matched filter (NPWMF) observers. It was demonstrated that an underestimated resolution blur (h = 4mm) enhanced task performance, while slight over-estimation (h = 7mm) also achieved enhanced performance. The latter is ironically attributed to the presence of ringing artifacts. Nonetheless, in the case of the NPWMF, the increasing intervoxel correlations with increasing values of h degrade detection task performance, and underestimation of the true PSF provides the optimal task performance. The proposed framework also achieves significant improvement of reproducibility, which is critical in quantitative imaging tasks such as treatment response monitoring.

  16. PET/CT and MR imaging in myeloma

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, Michael E. [University of Maryland Medical Center, Department of Radiology, Baltimore, MD (United States); Badros, Ashraf Z. [University of Maryland, Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, Baltimore, MD (United States)

    2007-01-15

    Myeloma is the most common primary bone malignancy. It accounts for 10% of all hematological malignancies and 1% of all cancers. In the United States, there are an estimated 16,000 new cases and over 11,000 deaths yearly due to myeloma. Plasma cell dyscrasias manifest themselves in a variety of forms that range from MGUS (monoclonal gammopathy of undetermined significance) and smoldering myeloma that require no therapy, to the ''malignant'' form of multiple myeloma. The role of imaging in the management of myeloma includes: an assessment of the extent of intramedullary bone disease, detection of any extramedullary foci, and severity of the disease at presentation; the identification and characterization of complications; subsequent assessment of disease status. This review will focus on the use of PET/CT and MR imaging for myeloma patients at the time of initial diagnosis and for follow-up management, based on current reports in the literature and our practice at the Marlene and Stewart Greenebaum Cancer Center, University of Maryland Medical Center in Baltimore, USA. (orig.)

  17. PET/CT and MR imaging in myeloma

    International Nuclear Information System (INIS)

    Myeloma is the most common primary bone malignancy. It accounts for 10% of all hematological malignancies and 1% of all cancers. In the United States, there are an estimated 16,000 new cases and over 11,000 deaths yearly due to myeloma. Plasma cell dyscrasias manifest themselves in a variety of forms that range from MGUS (monoclonal gammopathy of undetermined significance) and smoldering myeloma that require no therapy, to the ''malignant'' form of multiple myeloma. The role of imaging in the management of myeloma includes: an assessment of the extent of intramedullary bone disease, detection of any extramedullary foci, and severity of the disease at presentation; the identification and characterization of complications; subsequent assessment of disease status. This review will focus on the use of PET/CT and MR imaging for myeloma patients at the time of initial diagnosis and for follow-up management, based on current reports in the literature and our practice at the Marlene and Stewart Greenebaum Cancer Center, University of Maryland Medical Center in Baltimore, USA. (orig.)

  18. A pretargeting system for tumor PET imaging and radioimmunotherapy

    Directory of Open Access Journals (Sweden)

    Françoise eKraeber-Bodéré

    2015-03-01

    Full Text Available Labeled antibodies, as well as their fragments and antibody-derived recombinant constructs, have long been proposed as general vectors to target radionuclides to tumor lesions for imaging and therapy. They have indeed shown promise in both imaging and therapeutic applications, but they have not fulfilled the original expectations of achieving sufficient image contrast for tumor detection or sufficient radiation dose delivered to tumors for therapy. Pretargeting was originally developed for tumor immunoscintigraphy. It was assumed that directly-radiolabled antibodies could be replaced by an unlabeled immunoconjugate capable of binding both a tumor-specific antigen and a small molecular weight molecule. The small molecular weight molecule would carry the radioactive payload and would be injected after the bispecific immunoconjugate. It has been demonstrated that this approach does allow for both antibody-specific recognition and fast clearance of the radioactive molecule, thus resulting in improved tumor-to-normal tissue contrast ratios. It was subsequently shown that pretargeting also held promise for tumor therapy, translating improved tumor-to-normal tissue contrast ratios into more specific delivery of absorbed radiation doses. Many technical approaches have been proposed to implement pretargeting, and two have been extensively documented. One is based on the avidin-biotin system, and the other on bispecific antibodies binding a tumor-specific antigen and a hapten. Both have been studied in preclinical models, as well as in several clinical studies, and have shown improved targeting efficiency. This article reviews the historical and recent preclinical and clinical advances in the use of bispecific-antibody-based pretargeting for radioimmunodetection and radioimmunotherapy of cancer. The results of recent evaluation of pretargeting in PET imaging also are discussed.

  19. Artifacts and pitfalls in oncologic {sup 18}F-FDG-PET-CT imaging; Artefakte und Fallstricke in der onkologischen {sup 18}F-FDG-PET-CT-Diagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Falck, Christian von [Medizinische Hochschule Hannover (Germany). Schwerpunkt multimodale Bildgebung; Raatschen, Hans-Juergen [Charite Berlin (Germany). Radiologie; Bengel, Frank M. [Medizinische Hochschule Hannover (Germany)

    2011-12-15

    Hybrid imaging such as {sup 18}F-FDG PET-CT synergistically combines the advantages of metabolic and morphologic imaging. Due to its increasing role in the imaging of oncologic disease there is a growing demand for the general radiologists to have a basic unterstanding of the method and its limitations. Therefore, the objective of this review is to explain und illustrate the typical artifacts and pitfalls of oncologic PET-CT imaging using {sup 18}F-FDG. (orig.)

  20. PET imaging of neuroinflammation in a rat traumatic brain injury model with radiolabeled TSPO ligand DPA-714

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yu [Medical School of Southeast University, Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Nanjing (China); National Institutes of Health - NIH, Laboratory of Molecular Imaging and Nanomedicine - LOMIN, National Institute of Biomedical Imaging and Bioengineering - NIBIB, Bethesda, MD (United States); Yue, Xuyi; Kiesewetter, Dale O.; Niu, Gang; Chen, Xiaoyuan [National Institutes of Health - NIH, Laboratory of Molecular Imaging and Nanomedicine - LOMIN, National Institute of Biomedical Imaging and Bioengineering - NIBIB, Bethesda, MD (United States); Teng, Gaojun [Medical School of Southeast University, Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Nanjing (China)

    2014-07-15

    The inflammatory response in injured brain parenchyma after traumatic brain injury (TBI) is crucial in the pathological process. In order to follow microglia activation and neuroinflammation after TBI, we performed PET imaging in a rat model of TBI using {sup 18}F-labeled DPA-714, a ligand of the 18-kDa translocator protein (TSPO). TBI was induced in male SD rats by a controlled cortical impact. The success of the TBI model was confirmed by MRI. [{sup 18}F]DPA-714 was synthesized using a slightly modified TRACERLab FX-FN module and an automated procedure. In vivo PET imaging was performed at different time points after surgery using an Inveon small-animal PET scanner. The specificity of [{sup 18}F]DPA-714 was confirmed by a displacement study with an unlabeled competitive TSPO ligand, PK11195. Ex vivo autoradiography as well as immunofluorescence staining was carried out to confirm the in vivo PET results. Both in vivo T{sub 2}-weighted MR images and ex vivo TTC staining results revealed successful establishment of the TBI model. Compared with the sham-treated group, [{sup 18}F]DPA-714 uptake was significantly higher in the injured brain area on PET images. Increased lesion-to-normal ratios of [{sup 18}F]DPA-714 were observed in the brain of TBI rats on day 2 after surgery. Ratios peaked around day 6 (2.65 ± 0.36) and then decreased gradually to nearly normal levels on day 28. The displacement study using PK11195 confirmed the specific binding of [{sup 18}F]DPA-714 to TSPO. The results of ex vivo autoradiography were consistent with in vivo PET results. Immunofluorescence staining showed the time course of TSPO expression after TBI and the temporal and the spatial distribution of microglia in the damaged brain area. TSPO-targeted PET using [{sup 18}F]DPA-714 as the imaging probe can be used to dynamically monitor the inflammatory response after TBI in a noninvasive manner. This method will not only facilitate a better understanding of the inflammatory process

  1. Dual-modality PET/CT imaging: the effect of respiratory motion on combined image quality in clinical oncology

    International Nuclear Information System (INIS)

    To reduce potential mis-registration from differences in the breathing pattern between two complementary PET and CT data sets, patients are generally allowed to breathe quietly during a dual-modality scan using a combined PET/CT tomograph. Frequently, however, local mis-registration between the CT and the PET is observed. We have evaluated the appearance, magnitude, and frequency of respiration-induced artefacts in CT images of dual-modality PET/CT studies of 62 patients. Combined PET/CT scans during normal respiration were acquired in 43 subjects using single- or dual-slice CT. Nineteen patients were scanned with a special breathing protocol (limited breath-hold technique) on a single-slice PET/CT tomograph. All subjects were injected with 370 MBq of FDG, and PET/CT scanning commenced 1 h post injection. The CT images were reconstructed and, after appropriate scaling, used for on-line attenuation correction of the PET emission data. We found that respiration artefacts can occur in the majority of cases if no respiration protocol is used. When applying the limited breath-hold technique, the frequency of severe artefacts in the area of the diaphragm was reduced by half, and the spatial extent of respiration-induced artefacts was reduced by at least 40% compared with the acquisition protocols without any breathing instructions. In conclusion, special breathing protocols are effective and should be used for CT scans as part of combined imaging protocols using a dual-modality PET/CT tomograph. The results of this study can also be applied to multi-slice CT to potentially reduce further breathing artefacts in PET/CT imaging and to improve overall image quality. (orig.)

  2. PET imaging of hepatocellular carcinoma with {sup 18}F-fluoroethylcholine and {sup 11}C-choline

    Energy Technology Data Exchange (ETDEWEB)

    Kolthammer, Jeffrey A.; Tenley, Nathan [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); Corn, David J.; Wu, Chunying; Tian, Haibin; Wang, Yanming [University Hospitals Case Medical Center, Nuclear Medicine Division, Department of Radiology, Cleveland, OH (United States); Lee, Zhenghong [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); University Hospitals Case Medical Center, Nuclear Medicine Division, Department of Radiology, Cleveland, OH (United States)

    2011-07-15

    Choline-based radiotracers have been studied for PET imaging of hepatocellular carcinoma (HCC). Using an {sup 18}F-labeled choline analog, instead of the {sup 11}C-labeled native choline, would facilitate its widespread use in the clinic. In this study, PET with {sup 18}F-fluoroethylcholine (FEC) and {sup 11}C-choline (CHOL) were compared using an animal model of HCC. The effects of fasting on the performance of choline-based tracers were also investigated. A woodchuck model of HCC was used to compare the two tracers, which were administered and imaged in sequence during the same imaging session. Dynamic PET images were generated spanning 50 min starting from tracer injection. Time-activity curves and tracer contrast were calculated in liver regions with tracer accumulation, and the contrast at a late time-point with the two tracers, and between fasted and nonfasted states, were compared. Foci of HCC with increased uptake ranged in size from 1.0 to 1.6 cm, with mean tumor-to-background contrast of 1.3 with FEC and 1.5 with CHOL at 50 min after injection. The tracers show similar patterns of uptake immediately following administration, and both activities plateaued at 10 min after injection. No significant differences in uptake dynamics or final contrast were observed between the fasted and nonfasted states. PET imaging of HCC is possible with both CHOL and FEC. Fasting was not found to affect accumulation of either tracer. These results encourage further investigation into the clinical utility of FEC for HCC imaging. (orig.)

  3. Metal artifact reduction strategies for improved attenuation correction in hybrid PET/CT imaging.

    Science.gov (United States)

    Abdoli, Mehrsima; Dierckx, Rudi A J O; Zaidi, Habib

    2012-06-01

    Metallic implants are known to generate bright and dark streaking artifacts in x-ray computed tomography (CT) images, which in turn propagate to corresponding functional positron emission tomography (PET) images during the CT-based attenuation correction procedure commonly used on hybrid clinical PET/CT scanners. Therefore, visual artifacts and overestimation and/or underestimation of the tracer uptake in regions adjacent to metallic implants are likely to occur and as such, inaccurate quantification of the tracer uptake and potential erroneous clinical interpretation of PET images is expected. Accurate quantification of PET data requires metal artifact reduction (MAR) of the CT images prior to the application of the CT-based attenuation correction procedure. In this review, the origins of metallic artifacts and their impact on clinical PET/CT imaging are discussed. Moreover, a brief overview of proposed MAR methods and their advantages and drawbacks is presented. Although most of the presented MAR methods are mainly developed for diagnostic CT imaging, their potential application in PET/CT imaging is highlighted. The challenges associated with comparative evaluation of these methods in a clinical environment in the absence of a gold standard are also discussed.

  4. Metal artifact reduction strategies for improved attenuation correction in hybrid PET/CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Abdoli, Mehrsima; Dierckx, Rudi A. J. O.; Zaidi, Habib [Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, 9700 RB Groningen (Netherlands); Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva (Switzerland); Geneva Neuroscience Center, Geneva University, CH-1205 Geneva (Switzerland) and Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, 9700 RB Groningen (Netherlands)

    2012-06-15

    Metallic implants are known to generate bright and dark streaking artifacts in x-ray computed tomography (CT) images, which in turn propagate to corresponding functional positron emission tomography (PET) images during the CT-based attenuation correction procedure commonly used on hybrid clinical PET/CT scanners. Therefore, visual artifacts and overestimation and/or underestimation of the tracer uptake in regions adjacent to metallic implants are likely to occur and as such, inaccurate quantification of the tracer uptake and potential erroneous clinical interpretation of PET images is expected. Accurate quantification of PET data requires metal artifact reduction (MAR) of the CT images prior to the application of the CT-based attenuation correction procedure. In this review, the origins of metallic artifacts and their impact on clinical PET/CT imaging are discussed. Moreover, a brief overview of proposed MAR methods and their advantages and drawbacks is presented. Although most of the presented MAR methods are mainly developed for diagnostic CT imaging, their potential application in PET/CT imaging is highlighted. The challenges associated with comparative evaluation of these methods in a clinical environment in the absence of a gold standard are also discussed.

  5. Robust framework for PET image reconstruction incorporating system and measurement uncertainties.

    Directory of Open Access Journals (Sweden)

    Huafeng Liu

    Full Text Available In Positron Emission Tomography (PET, an optimal estimate of the radioactivity concentration is obtained from the measured emission data under certain criteria. So far, all the well-known statistical reconstruction algorithms require exactly known system probability matrix a priori, and the quality of such system model largely determines the quality of the reconstructed images. In this paper, we propose an algorithm for PET image reconstruction for the real world case where the PET system model is subject to uncertainties. The method counts PET reconstruction as a regularization problem and the image estimation is achieved by means of an uncertainty weighted least squares framework. The performance of our work is evaluated with the Shepp-Logan simulated and real phantom data, which demonstrates significant improvements in image quality over the least squares reconstruction efforts.

  6. Introduction to the physics of molecular imaging with radioactive tracers in small animals.

    Science.gov (United States)

    King, Michael A; Pretorius, P Hendrik; Farncombe, Troy; Beekman, Freek J

    2002-01-01

    Recent advances have greatly enhanced the three-dimensional (3D) imaging of radioactive tracers in living animals. this article introduces the physics of imaging behind the imaging methods. The article first discusses the selection of the radiation emitted from the tracer and then the process of tomographic reconstruction or how 3D images are made from imaging around the outside of the animal. The technique of single photon emission computed tomography (SPECT) in which the detection of one X-ray or gamma ray at a time is employed for image formation is then described. Finally, positron emission tomography (PET) which relies on the simultaneous detection of the pair of gamma-rays formed when the positron annihilates is presented.

  7. {sup 18}F-FDG PET/CT in paediatric lymphoma: comparison with conventional imaging

    Energy Technology Data Exchange (ETDEWEB)

    London, Kevin [Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); Cross, Siobhan; Dalla-Pozza, Luciano [Children' s Hospital at Westmead, Oncology Unit, Sydney (Australia); Onikul, Ella [Children' s Hospital at Westmead, Department of Medical Imaging, Sydney (Australia); Howman-Giles, Robert [Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Discipline of Imaging, Sydney Medical School, Sydney (Australia)

    2011-02-15

    In children with Hodgkin's disease and non-Hodgkin's lymphoma, the ability of {sup 18}F-fluoro-2-deoxy-D-glucose PET/CT and conventional imaging (CI) to detect malignant lesions and predict poor lesion response to therapy was assessed and compared. A retrospective review of findings reported on PET/CT and CI was performed using a lesion-based analysis of 16 lymph node and 8 extra-nodal regions. Lesions were defined by histopathological findings or follow-up > 6 months. The study included 209 PET/CT scans with a valid CI comparator. A total of 5,014 regions (3,342 lymph node, 1,672 extra-nodal) were analysed. PET/CT performed significantly better than CI in the detection of malignant lesions with sensitivity and specificity of 95.9 and 99.7% compared to 70.1 and 99.0%, respectively. For predicting poor lesion response to therapy, PET/CT had fewer false-positive lesions than CI. The specificity for predicting poor lesion response to treatment for PET/CT was 99.2% compared to 96.9% for CI. PET/CT was the correct modality in 86% of lesions with discordant findings. PET/CT is more accurate than CI in detecting malignant lesions in childhood lymphoma and in predicting poor lesion response to treatment. In lesions with discordant findings, PET/CT results are more likely to be correct. (orig.)

  8. 18F-FDG PET/CT in paediatric lymphoma: comparison with conventional imaging

    International Nuclear Information System (INIS)

    In children with Hodgkin's disease and non-Hodgkin's lymphoma, the ability of 18F-fluoro-2-deoxy-D-glucose PET/CT and conventional imaging (CI) to detect malignant lesions and predict poor lesion response to therapy was assessed and compared. A retrospective review of findings reported on PET/CT and CI was performed using a lesion-based analysis of 16 lymph node and 8 extra-nodal regions. Lesions were defined by histopathological findings or follow-up > 6 months. The study included 209 PET/CT scans with a valid CI comparator. A total of 5,014 regions (3,342 lymph node, 1,672 extra-nodal) were analysed. PET/CT performed significantly better than CI in the detection of malignant lesions with sensitivity and specificity of 95.9 and 99.7% compared to 70.1 and 99.0%, respectively. For predicting poor lesion response to therapy, PET/CT had fewer false-positive lesions than CI. The specificity for predicting poor lesion response to treatment for PET/CT was 99.2% compared to 96.9% for CI. PET/CT was the correct modality in 86% of lesions with discordant findings. PET/CT is more accurate than CI in detecting malignant lesions in childhood lymphoma and in predicting poor lesion response to treatment. In lesions with discordant findings, PET/CT results are more likely to be correct. (orig.)

  9. MRI-guided brain PET image filtering and partial volume correction.

    Science.gov (United States)

    Yan, Jianhua; Lim, Jason Chu-Shern; Townsend, David W

    2015-02-01

    Positron emission tomography (PET) image quantification is a challenging problem due to limited spatial resolution of acquired data and the resulting partial volume effects (PVE), which depend on the size of the structure studied in relation to the spatial resolution and which may lead to over or underestimation of the true tissue tracer concentration. In addition, it is usually necessary to perform image smoothing either during image reconstruction or afterwards to achieve a reasonable signal-to-noise ratio. Typically, an isotropic Gaussian filtering (GF) is used for this purpose. However, the noise suppression is at the cost of deteriorating spatial resolution. As hybrid imaging devices such as PET/MRI have become available, the complementary information derived from high definition morphologic images could be used to improve the quality of PET images. In this study, first of all, we propose an MRI-guided PET filtering method by adapting a recently proposed local linear model and then incorporate PVE into the model to get a new partial volume correction (PVC) method without parcellation of MRI. In addition, both the new filtering and PVC are voxel-wise non-iterative methods. The performance of the proposed methods were investigated with simulated dynamic FDG brain dataset and (18)F-FDG brain data of a cervical cancer patient acquired with a simultaneous hybrid PET/MR scanner. The initial simulation results demonstrated that MRI-guided PET image filtering can produce less noisy images than traditional GF and bias and coefficient of variation can be further reduced by MRI-guided PET PVC. Moreover, structures can be much better delineated in MRI-guided PET PVC for real brain data. PMID:25575248

  10. Anomaly Detection and Artifact Recovery in PET Attenuation-Correction Images Using the Likelihood Function

    OpenAIRE

    Laymon, Charles M; Bowsher, James E.

    2013-01-01

    In dual modality PET/CT, CT data are used to generate the attenuation correction applied in the reconstruction of the PET emission image. This requires converting the CT image into a 511-keV attenuation map. Algorithms for making this transformation require assumptions about the makeup of material within the patient. Anomalous material such as contrast agent administered to enhance the CT scan confounds conversion algorithms and has been observed to result in inaccuracies, i.e., inconsistenci...

  11. Utility of high-definition FDG-PET image reconstruction for lung cancer staging

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Yoshiyuki; Hara, Masaki; Shibamoto, Yuta [Dept. of Radiology, Nagoya City Univ. Graduate School of Medical Sciences, Aichi (Japan)], e-mail: ykiooster@gmail.com; Tamaki, Tsuneo; Omi, Kumiko [Dept. of Radiology, East Nagoya Imaging Diagnosis Center, Aichi (Japan); Nishio, Masami [Dept. of Radiology, Nagoya PET Imaging Center, Aichi (Japan)

    2013-10-15

    Background: High-definition (HD) positron emission tomography (PET) image reconstruction is a new image reconstruction method based on the point spread function system, which improves the spatial resolution of the images. Purpose: To compare the utility of HD reconstruction of PET images for staging lung cancer with that of conventional 2D ordered subset expectation maximization + Fourier rebinning (2D) reconstruction. Material and Methods: Thirty-five lung cancer patients (24 men, 11 women; median age, 66 years) who underwent surgery after 18F-2-deoxy-fluoro-D-glucose (FDG)-PET-CT were studied. Their PET data were reconstructed with 2D and HD PET reconstruction algorithms. Two radiologists individually TNM staged both sets of images. They also evaluated the quality of the images and the diagnostic confidence that the images afforded them using 5-point scales. Results: T, N, and M stages were correctly diagnosed on both the 2D and HD reconstructed images in 23 (66%), 25 (71%), and 30 (86%) of 35 cases, respectively. Overall TNM stage was correctly diagnosed on both types of reconstructed images in 23 cases (66%), underestimated in three (9%), and overestimated in nine (26%). No significant difference in T, N, or M stage or overall TNM stage was observed between the two reconstruction methods. However, the HD reconstructed images afforded a significantly higher level of diagnostic confidence during TNM staging than the 2D reconstructed images and were also of higher quality than the 2D reconstructed images. Conclusion: Although HD reconstruction of FDG-PET images did not improve the diagnostic accuracy of lung cancer staging compared with 2D reconstruction, the quality of the HD reconstructed images and the diagnostic confidence level they afforded the radiologists were higher than those of the conventional 2D reconstructed images.

  12. PET molecular imaging of peripheral and central inflammatory processes targeting the TSPO 18 kDa

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the in vivo potential of the TSPO 18 kDa as a bio-marker of inflammation, with the use of its radioligand [18F]DPA-714, to non-invasively quantify the inflammatory state within the scope of various pathologies. Multiple animal models of various inflammatory diseases, to include: inflammatory bowel disease, neuro-inflammation, and septic shock, were developed and put in place by adapted measures. The animals well-being and the subsequent inflammation was evaluated. The inflammatory state was measured using quantitative PET imaging with the TSPO radioligand [18F]DPA-714 and correlated to the expression of conventional inflammatory markers using microscopy. Based on the observed data, we were able to distinguish control groups from treated groups when using [18F]DPA-714. This TSPO radioligand permitted us to quantify the inflammatory level and to observe evolutionary changes in the inflammatory state of the disease in multiple models. The PET results, using the [18F]DPA-714 signal was correlated with an increased TSPO expression at cellular level. Results indicate that [18F]DPA-714 is a suitable tracer for studying inflammation of multiple diseases. [18F]DPA-714 could be a good molecular probe to non-invasively evaluate the level and localization of inflammation. Moreover, in vivo imaging using this TSPO ligand is potentially a powerful tool to stage and certainly to follow the evolution and therapeutic efficiency at molecular level in inflammatory diseases. (author)

  13. Implementation and assessment of an animal management system for small-animal micro-CT / micro-SPECT imaging

    Science.gov (United States)

    Holdsworth, David W.; Detombe, Sarah A.; Chiodo, Chris; Fricke, Stanley T.; Drangova, Maria

    2011-03-01

    Advances in laboratory imaging systems for CT, SPECT, MRI, and PET facilitate routine micro-imaging during pre-clinical investigations. Challenges still arise when dealing with immune-compromised animals, biohazardous agents, and multi-modality imaging. These challenges can be overcome with an appropriate animal management system (AMS), with the capability for supporting and monitoring a rat or mouse during micro-imaging. We report the implementation and assessment of a new AMS system for mice (PRA-3000 / AHS-2750, ASI Instruments, Warren MI), designed to be compatible with a commercial micro-CT / micro-SPECT imaging system (eXplore speCZT, GE Healthcare, London ON). The AMS was assessed under the following criteria: 1) compatibility with the imaging system (i.e. artifact generation, geometric dimensions); 2) compatibility with live animals (i.e. positioning, temperature regulation, anesthetic supply); 3) monitoring capabilities (i.e. rectal temperature, respiratory and cardiac monitoring); 4) stability of co-registration; and 5) containment. Micro-CT scans performed using a standardized live-animal protocol (90 kVp, 40 mA, 900 views, 16 ms per view) exhibited low noise (+/-19 HU) and acceptable artifact from high-density components within the AMS (e.g. ECG pad contacts). Live mice were imaged repeatedly (with removal and replacement of the AMS) and spatial registration was found to be stable to within +/-0.07 mm. All animals tolerated enclosure within the AMS for extended periods (i.e. > one hour) without distress, based on continuous recordings of rectal temperature, ECG waveform and respiratory rate. A sealed AMS system extends the capability of a conventional micro-imaging system to include immune-compromised and biosafety level 2 mouse-imaging protocols.

  14. FDG Co-PET imaging of occult primary tumour presenting with metastatic disease

    International Nuclear Information System (INIS)

    Full text: The management of patients with known metastatic disease but no clinically apparent primary site remains a challenge. We assessed Coincidence Positron Emission Tomography (Co-PET) with Fluorodeoxyglucose (FDG) in the detection of occult primary tumour in patients with proven metastatic disease. Nineteen patients with biopsy proven metastatic cervical adenopathy (7) or extracervical metastases (12) from occult primary tumours were evaluated with FDG Co-PET. All patients had appropriate conventional anatomical imaging within one month of FDG Co-PET during the period of December 1997 to December 2001. Whole body imaging was performed with an ADAC Solus Co-PET scanner 60 minutes after 185 MBq FDG administration. The results of Co-PET imaging were correlated with conventional anatomical imaging. FDG Co-PET suggested the primary tumour sites in 7 of the 19 patients (37%): pancreas (1), hypopharynx (1), oropharynx (1) lung (1), oesophagus (1), right kidney (1) and ascending colon (1). Three of these cases were confirmed either with serological tumour marker (1) or clinical course of disease (2) with potential management impacts. Compared with conventional anatomical imaging for detection of metastatic sites, FDG Co-PET was concordant in 9 patients (47%). Co-PET detected extra sites in 8 patients (42%), and detected fewer sites in 2 patients (11%) both whom had excision biopsies. FDG Co-PET was successful in localizing occult primary tumour in a limited number of patients presenting with metastatic disease with potential management impact. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  15. Derivation of the scan time requirement for maintaining a consistent PET image quality

    Science.gov (United States)

    Kim, Jin Su; Lee, Jae Sung; Kim, Seok-Ki

    2015-05-01

    Objectives: the image quality of PET for larger patients is relatively poor, even though the injection dose is optimized considering the NECR characteristics of the PET scanner. This poor image quality is due to the lower level of maximum NECR that can be achieved in these large patients. The aim of this study was to optimize the PET scan time to obtain a consistent PET image quality regardless of the body size, based on the relationship between the patient specific NECR (pNECR) and body weight. Methods: eighty patients (M/F=53/27, body weight: 059 ± 1 kg) underwent whole-body FDG PET scans using a Philips GEMINI GS PET/CT scanner after an injection of 0.14 mCi/kg FDG. The relationship between the scatter fraction (SF) and body weight was determined by repeated Monte Carlo simulations using a NEMA scatter phantom, the size of which varied according to the relationship between the abdominal circumference and body weight. Using this information, the pNECR was calculated from the prompt and delayed PET sinograms to obtain the prediction equation of NECR vs. body weight. The time scaling factor (FTS) for the scan duration was finally derived to make PET images with equivalent SNR levels. Results: the SF and NECR had the following nonlinear relationships with the body weight: SF=0.15 ṡ body weight0.3 and NECR = 421.36 (body weight)-0.84. The equation derived for FTS was 0.01ṡ body weight + 0.2, which means that, for example, a 120-kg person should be scanned 1.8 times longer than a 70 kg person, or the scan time for a 40-kg person can be reduced by 30%. Conclusion: the equation of the relative time demand derived in this study will be useful for maintaining consistent PET image quality in clinics.

  16. Pragmatic fully 3D image reconstruction for the MiCES mouse imaging PET scanner

    International Nuclear Information System (INIS)

    We present a pragmatic approach to image reconstruction for data from the micro crystal elements system (MiCES) fully 3D mouse imaging positron emission tomography (PET) scanner under construction at the University of Washington. Our approach is modelled on fully 3D image reconstruction used in clinical PET scanners, which is based on Fourier rebinning (FORE) followed by 2D iterative image reconstruction using ordered-subsets expectation-maximization (OSEM). The use of iterative methods allows modelling of physical effects (e.g., statistical noise, detector blurring, attenuation, etc), while FORE accelerates the reconstruction process by reducing the fully 3D data to a stacked set of independent 2D sinograms. Previous investigations have indicated that non-stationary detector point-spread response effects, which are typically ignored for clinical imaging, significantly impact image quality for the MiCES scanner geometry. To model the effect of non-stationary detector blurring (DB) in the FORE+OSEM(DB) algorithm, we have added a factorized system matrix to the ASPIRE reconstruction library. Initial results indicate that the proposed approach produces an improvement in resolution without an undue increase in noise and without a significant increase in the computational burden. The impact on task performance, however, remains to be evaluated

  17. A PRELIMINARY STUDY ON COMPARISON AND FUSION OF METABOLIC IMAGES OF PET WITH ANATOMIC IMAGES OF CT AND MRI

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective. To compare and match metabolic images of PET with anatomic images of CT and MRI. Methods. The CT or MRI images of the patients were obtained through a photo scanner, and then transferred to the remote workstation of PET scanner with a floppy disk. A fusion method was developed to match the 2-dimensional CT or MRI slices with the correlative slices of 3-dimensional volume PET images. Results. Twenty- nine metabolically changed foci were accurately localized in 21 epilepsy patients' MRI images, while MRI alone had only 6 true positive findings. In 53 cancer or suspicious cancer patients, 53 positive lesions detected by PET were compared and matched with the corresponding lesions in CT or MRI images, in which 10 lesions were missed. On the other hand, 23 lesions detected from the patients' CT or MRI images were negative or with low uptake in the PET images, and they were finally proved as benign. Conclusions. Comparing and matching metabolic images with anatomic images helped obtain a full understanding about the lesion and its peripheral structures. The fusion method was simple, practical and useful for localizing metabolically changed lesions.

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

    Energy Technology Data Exchange (ETDEWEB)

    Covello, M., E-mail: echoplanare@gmail.com [IRCCS SDN, Via E. Gianturco, 111-113 – 80143, Naples (Italy); Cavaliere, C.; Aiello, M.; Cianelli, M.S. [IRCCS SDN, Via E. Gianturco, 111-113 – 80143, Naples (Italy); Mesolella, M.; Iorio, B. [Department of Otorhinolaryngoiatry, Federico II University, Naples (Italy); Rossi, A.; Nicolai, E. [IRCCS SDN, Via E. Gianturco, 111-113 – 80143, Naples (Italy)

    2015-07-15

    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 pri