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Sample records for cardiac pet images

  1. Cardiac Applications of PET/MR Imaging.

    Science.gov (United States)

    Lau, Jeffrey M C; Laforest, Richard; Nensa, Felix; Zheng, Jie; Gropler, Robert J; Woodard, Pamela K

    2017-05-01

    Simultaneous acquisition PET/MR imaging combines the anatomic capabilities of cardiac MR imaging with quantitative capabilities of both PET and MR imaging. Cardiac PET/MR imaging has the potential not only to assess cardiac tumors but also to provide thorough assessment of myocardial ischemia, infarction, and function and specific characterization of cardiomyopathies, such as cardiac sarcoid. In this article, the authors start with a discussion of the technical challenges specific to cardiovascular PET/MR imaging followed by a discussion of the use of PET/MR imaging in various cardiovascular conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Cardiac sympathetic neuronal imaging using PET

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    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.)

  3. PET imaging of human cardiac opioid receptors

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    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.)

  4. Assessment of cardiac autonomic neuronal function using PET imaging.

    Science.gov (United States)

    Thackeray, James T; Bengel, Frank M

    2013-02-01

    The autonomic nervous system is the primary extrinsic control of cardiac performance, and altered autonomic activity has been recognized as an important factor in the progression of various cardiac pathologies. Molecular imaging techniques have been developed for global and regional interrogation of pre- and postsynaptic targets of the cardiac autonomic nervous system. Building on established work with the guanethidine analogue ¹²³I-metaiodobenzylguanidine (MIBG) for single-photon emission tomography (SPECT), development of radiotracers and protocols for positron emission tomography (PET) investigation of autonomic signaling has expanded. PET is limited in availability and requires specialized centers for radiosynthesis and interpretation, but the higher resolution allows for improved regional analysis and kinetic modeling provides more true quantification than is possible with SPECT. A wider array of radiolabeled catecholamines, analogues of catecholamines, and receptor ligands have been characterized and evaluated. Sympathetic neuronal PET tracers have shown promise in the identification of several cardiac pathologies. In particular, recent studies have elucidated a mechanistic role for heterogeneous sympathetic innervation in the development of lethal ventricular arrhythmias. Evaluation of cardiomyocyte adrenergic receptor expression and the parasympathetic nervous system has been slower to develop, with clinical studies beginning to emerge. This review summarizes the clinical and the experimental PET tracers currently available for autonomic imaging and discusses their application in health and cardiovascular disease, with particular emphasis on the major findings of the last decade.

  5. Molecular cardiac PET besides FDG viability imaging; Molekulare Kardiale PET jenseits der FDG-Vitalitaetsdiagnostik

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    Lindner, O.; Burchert, W. [Universitaetsklinik der Ruhr-Univ. Bochum (Germany). Inst. fuer Radiologie, Nuklearmedizin und Molekulare Bildgebung, Herz- und Diabetszentrum NRW

    2009-06-15

    Molecular cardiac non F-18-FDG PET is currently based on perfusion imaging. It is of excellent diagnostic accuracy to detect coronary artery disease (CAD) and superior to perfusion SPECT. There is also evidence for its incremental prognostic value. The unique feature of PET to measure myocardial perfusion in absolute terms and in short time periods define its impact on cardiac imaging enabling both the evaluation of early changes in CAD and the accurate characterization of multivessel disease. Currently, all available PET perfusion tracers in Europe are cyclotron products. Rb-82, a generator product, is the most frequently employed perfusion tracer in the United States and cyclotron independent. This tracer has the potential to become an alternative in Europe soon. Nowadays, PET systems are manufactured as hybrid PET-CT scanners. In oncology, hybrid imaging revealed, that the combination of functional and morphological imaging is superior to the single components. In cardiology, the integration of perfusion PET imaging with CT calcium scoring and CT anatomy of the coronary arteries represents a similar constellation. Atherosclerotic plaque evaluation by combined PET-CT technique will be one of the most promising future applications with a potential immense impact on prophylaxis, diagnosis and therapy of CAD in the future. (orig.)

  6. Evaluation of respiratory and cardiac motion correction schemes in dual gated PET/CT cardiac imaging

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    Lamare, F., E-mail: frederic.lamare@chu-bordeaux.fr; Fernandez, P. [Univ. Bordeaux, INCIA, UMR 5287, F-33400 Talence (France); CNRS, INCIA, UMR 5287, F-33400 Talence (France); Service de Médecine Nucléaire, Hôpital Pellegrin, CHU de Bordeaux, 33076 Bordeaux (France); Le Maitre, A.; Visvikis, D. [INSERM, UMR1101, LaTIM, Université de Bretagne Occidentale, 29609 Brest (France); Dawood, M.; Schäfers, K. P. [European Institute for Molecular Imaging, University of Münster, Mendelstr. 11, 48149 Münster (Germany); Rimoldi, O. E. [Vita-Salute University and Scientific Institute San Raffaele, Milan, Italy and CNR Istituto di Bioimmagini e Fisiologia Molecolare, Milan (Italy)

    2014-07-15

    Purpose: Cardiac imaging suffers from both respiratory and cardiac motion. One of the proposed solutions involves double gated acquisitions. Although such an approach may lead to both respiratory and cardiac motion compensation there are issues associated with (a) the combination of data from cardiac and respiratory motion bins, and (b) poor statistical quality images as a result of using only part of the acquired data. The main objective of this work was to evaluate different schemes of combining binned data in order to identify the best strategy to reconstruct motion free cardiac images from dual gated positron emission tomography (PET) acquisitions. Methods: A digital phantom study as well as seven human studies were used in this evaluation. PET data were acquired in list mode (LM). A real-time position management system and an electrocardiogram device were used to provide the respiratory and cardiac motion triggers registered within the LM file. Acquired data were subsequently binned considering four and six cardiac gates, or the diastole only in combination with eight respiratory amplitude gates. PET images were corrected for attenuation, but no randoms nor scatter corrections were included. Reconstructed images from each of the bins considered above were subsequently used in combination with an affine or an elastic registration algorithm to derive transformation parameters allowing the combination of all acquired data in a particular position in the cardiac and respiratory cycles. Images were assessed in terms of signal-to-noise ratio (SNR), contrast, image profile, coefficient-of-variation (COV), and relative difference of the recovered activity concentration. Results: Regardless of the considered motion compensation strategy, the nonrigid motion model performed better than the affine model, leading to higher SNR and contrast combined with a lower COV. Nevertheless, when compensating for respiration only, no statistically significant differences were

  7. Cardiac PET imaging in mice with simultaneous cardiac and respiratory gating

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    Yang, Yongfeng; Rendig, Stephen; Siegel, Stefan; Newport, Danny F.; Cherry, Simon R.

    2005-07-01

    Gating firmware and software were developed for the microPET II small animal scanner. The measured cardiac and respiratory signals were collected and converted to TTL gating signals by a Biopac MP150 data acquisition system and sent to microPET II through two BNC connectors on the front panel. During acquisition, the coincidence monitor takes the average of the last eight gate input cycles and inserts this into the list mode data stream on the falling edge of the gating pulse. This value is then used to determine the current time interval of the next gate cycle when the list mode data are sorted into sinograms. The gating firmware and software were validated by an experiment using a rotating point source. Mouse heart (18F-FDG) and bone (18F-) imaging was performed with simultaneous cardiac and respiratory gating. It was clearly demonstrated that the contractile function of the mouse heart can be studied by cardiac-gated imaging with microPET II. The left ventricular volumes at different times of the cardiac cycle were measured and the ejection fraction was calculated. In the bone scan, no detectable movement caused by heart contraction was observed. Respiratory motion was more subtle with virtually no motion for more than 75% of the respiratory cycle. The motion of the mouse heart and bones in the thorax caused by respiration was less than 1 mm. It appears with the current resolution of PET, and the small fraction of the respiratory cycle in which motion occurs, that respiratory gating is probably not necessary for most mouse cardiac studies.

  8. 11C-Pittsburgh B PET imaging in cardiac amyloidosis.

    Science.gov (United States)

    Lee, Seung-Pyo; Lee, Eun Seong; Choi, Hongyoon; Im, Hyung-Jun; Koh, Youngil; Lee, Min-Ho; Kwon, Ji-Hyun; Paeng, Jin Chul; Kim, Hyung-Kwan; Cheon, Gi Jeong; Kim, Yong-Jin; Kim, Inho; Yoon, Sung-Soo; Seo, Jeong-Wook; Sohn, Dae-Won

    2015-01-01

    This study sought to investigate the efficacy of (11)C-Pittsburgh B (PiB) positron emission tomography (PET)/computed tomography (CT) in the diagnosis of cardiac amyloidosis. The PiB compound has been promising for detection of amyloid deposits in the brain. A total of 22 consecutive patients were enrolled in this prospective pilot study of monoclonal gammopathy patients with suspected cardiac amyloidosis. The study consisted of a series of (11)C-PiB PET/CT, echocardiography, cardiac magnetic resonance, and endomyocardial biopsy within a 1-month period. In addition, 10 normal subjects were recruited to determine the most optimal cut-off value for a positive (11)C-PiB PET/CT scan. Among the 22 patients, 15 patients were diagnosed as cardiac amyloidosis by endomyocardial biopsy and 5 patients had undergone chemotherapy previously before the (11)C-PiB PET/CT. There were no differences in echocardiographic parameters between patients with versus without cardiac amyloidosis, except for a marginal difference in the left ventricular end-diastolic dimension (median 41.0 mm [range 33.0 to 49.0 mm] vs. 50.0 mm [range 38.0 to 55.0 mm], p = 0.066). (11)C-PiB PET/CT was positive in 13 of 15 biopsy-proven cardiac amyloidosis patients, whereas none of the patients without cardiac amyloidosis demonstrated positive (11)C-PiB PET/CT scan results. The maximal myocardium-to-blood cavity ratio was significantly different between patients with versus without cardiac amyloidosis (median 3.9 [range 1.7 to 19.9] vs. 1.0 [range 0.8 to 1.2], p < 0.001). In association with the significant difference of (11)C-PiB uptake in the myocardium between the chemotherapy naïve versus the previous chemotherapy group (median 10.4 [range 1.7 to 19.9] vs. 2.3 [range 1.7 to 3.8], p = 0.014), all except 1 patient among the 5 previously treated patients had responded to chemotherapy by serum free light chain assay results at the time of (11)C-PiB PET/CT scan. (11)C-PiB PET/CT may be valuable for the

  9. Respiratory and cardiac motion correction in dual gated PET/MR imaging

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    Fayad, Hadi; Monnier, Florian [LaTIM, INSERM, UMR 1101, Brest (France); Odille, Freedy; Felblinger, Jacques [INSERM U947, University of Nancy, Nancy (France); Lamare, Frederic [INCIA, UMR5287, CNRS, CHU Bordeaux, Bordeaux (France); Visvikis, Dimitris [LaTIM, INSERM, UMR 1101, Brest (France)

    2015-05-18

    Respiratory and cardiac motion in PET/MR imaging leads to reduced quantitative and qualitative image accuracy. Correction methodologies involve the use of double gated acquisitions which lead to low signal-to-noise ratio (SNR) and to issues concerning the combination of cardiac and respiratory frames. The objective of this work is to use a generalized reconstruction by inversion of coupled systems (GRICS) approach, previously used for PET/MR respiratory motion correction, combined with a cardiac phase signal and a reconstruction incorporated PET motion correction approach in order to reconstruct motion free images from dual gated PET acquisitions. The GRICS method consists of formulating parallel MRI in the presence of patient motion as a coupled inverse problem. Its resolution, using a fixed-point method, allows the reconstructed image to be improved using a motion model constructed from the raw MR data and two respiratory belts. GRICS obtained respiratory displacements are interpolated using the cardiac phase derived from an ECG to model simultaneous cardiac and respiratory motion. Three different volunteer datasets (4DMR acquisitions) were used for evaluation. GATE was used to simulate 4DPET datasets corresponding to the acquired 4DMR images. Simulated data were subsequently binned using 16 cardiac phases (M1) vs diastole only (M2), in combination with 8 respiratory amplitude gates. Respiratory and cardiac motion corrected PET images using either M1 or M2 were compared to respiratory only corrected images and evaluated in terms of SNR and contrast improvement. Significant visual improvements were obtained when correcting simultaneously for respiratory and cardiac motion (using 16 cardiac phase or diastole only) compared to respiratory motion only compensation. Results were confirmed by an associated increased SNR and contrast. Results indicate that using GRICS is an efficient tool for respiratory and cardiac motion correction in dual gated PET/MR imaging.

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

    Science.gov (United States)

    Ai, Hua; Pan, Tinsu

    2015-07-08

    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.

  11. A novel dual gating approach using joint inertial sensors: implications for cardiac PET imaging

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    Jafari Tadi, Mojtaba; Teuho, Jarmo; Lehtonen, Eero; Saraste, Antti; Pänkäälä, Mikko; Koivisto, Tero; Teräs, Mika

    2017-10-01

    Positron emission tomography (PET) is a non-invasive imaging technique which may be considered as the state of art for the examination of cardiac inflammation due to atherosclerosis. A fundamental limitation of PET is that cardiac and respiratory motions reduce the quality of the achieved images. Current approaches for motion compensation involve gating the PET data based on the timing of quiescent periods of cardiac and respiratory cycles. In this study, we present a novel gating method called microelectromechanical (MEMS) dual gating which relies on joint non-electrical sensors, i.e. tri-axial accelerometer and gyroscope. This approach can be used for optimized selection of quiescent phases of cardiac and respiratory cycles. Cardiomechanical activity according to echocardiography observations was investigated to confirm whether this dual sensor solution can provide accurate trigger timings for cardiac gating. Additionally, longitudinal chest motions originating from breathing were measured by accelerometric- and gyroscopic-derived respiratory (ADR and GDR) tracking. The ADR and GDR signals were evaluated against Varian real-time position management (RPM) signals in terms of amplitude and phase. Accordingly, high linear correlation and agreement were achieved between the reference electrocardiography, RPM, and measured MEMS signals. We also performed a Ge-68 phantom study to evaluate possible metal artifacts caused by the integrated read-out electronics including mechanical sensors and semiconductors. The reconstructed phantom images did not reveal any image artifacts. Thus, it was concluded that MEMS-driven dual gating can be used in PET studies without an effect on the quantitative or visual accuracy of the PET images. Finally, the applicability of MEMS dual gating for cardiac PET imaging was investigated with two atherosclerosis patients. Dual gated PET images were successfully reconstructed using only MEMS signals and both qualitative and quantitative

  12. Recent Advances and Clinical Applications of PET Cardiac Autonomic Nervous System Imaging.

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    Boutagy, Nabil E; Sinusas, Albert J

    2017-04-01

    The purpose of this review was to summarize current advances in positron emission tomography (PET) cardiac autonomic nervous system (ANS) imaging, with a specific focus on clinical applications of novel and established tracers. [(11)C]-Meta-hydroxyephedrine (HED) has provided useful information in evaluation of normal and pathological cardiovascular function. Recently, [(11)C]-HED PET imaging was able to predict lethal arrhythmias, sudden cardiac death (SCD), and all-cause mortality in heart failure patients with reduced ejection fraction (HFrEF). In addition, initial [(11)C]-HED PET imaging studies have shown the potential of this agent in elucidating the relationship between impaired cardiac sympathetic nervous system (SNS) innervation and the severity of diastolic dysfunction in HF patients with preserved ejection fraction (HFpEF) and in predicting the response to cardiac resynchronization therapy (CRT) in HFrEF patients. Longer half-life (18)F-labeled presynaptic SNS tracers (e.g., [(18)F]-LMI1195) have been developed to facilitate clinical imaging, although no PET radiotracers that target the ANS have gained wide clinical use in the cardiovascular system. Although the use of parasympathetic nervous system radiotracers in cardiac imaging is limited, the novel tracer, [(11)C]-donepezil, has shown potential utility in initial studies. Many ANS radioligands have been synthesized for PET cardiac imaging, but to date, the most clinically relevant PET tracer has been [(11)C]-HED. Recent studies have shown the utility of [(11)C]-HED in relevant clinical issues, such as in the elusive clinical syndrome of HFpEF. Conversely, tracers that target cardiac PNS innervation have been used less clinically, but novel tracers show potential utility for future work. The future application of [(11)C]-HED and newly designed (18)F-labeled tracers for targeting the ANS hold promise for the evaluation and management of a wide range of cardiovascular diseases, including the

  13. MR-based motion correction for cardiac PET parametric imaging: a simulation study.

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    Guo, Rong; Petibon, Yoann; Ma, Yixin; El Fakhri, Georges; Ying, Kui; Ouyang, Jinsong

    2018-02-01

    Both cardiac and respiratory motions bias the kinetic parameters measured by dynamic PET. The aim of this study was to perform a realistic positron emission tomography-magnetic resonance (PET-MR) simulation study using 4D XCAT to evaluate the impact of MR-based motion correction on the estimation of PET myocardial kinetic parameters using PET-MR. Dynamic activity distributions were obtained based on a one-tissue compartment model with realistic kinetic parameters and an arterial input function. Realistic proton density/T1/T2 values were also defined for the MRI simulation. Two types of motion patterns, cardiac motion only (CM) and both cardiac and respiratory motions (CRM), were generated. PET sinograms were obtained by the projection of the activity distributions. PET image for each time frame was obtained using static (ST), gated (GA), non-motion-corrected (NMC), and motion-corrected (MC) methods. Voxel-wise unweighted least squares fitting of the dynamic PET data was then performed to obtain K 1 values for each study. For each study, the mean and standard deviation of K 1 values were computed for four regions of interest in the myocardium across 25 noise realizations. Both cardiac and respiratory motions introduce blurring in the PET parametric images if the motion is not corrected. Conventional cardiac gating is limited by high noise level on parametric images. Dual cardiac and respiratory gating further increases the noise level. In contrast to GA, the MR-based MC method reduces motion blurring in parametric images without increasing noise level. It also improves the myocardial defect delineation as compared to NMC method. Finally, the MR-based MC method yields lower bias and variance in K 1 values than NMC and GA, respectively. The reductions of K 1 bias by MR-based MC are 7.7, 5.1, 15.7, and 29.9% in four selected 0.18-mL myocardial regions of interest, respectively, as compared to NMC for CRM. MR-based MC yields 85.9, 75.3, 71.8, and 95.2% less K 1 standard

  14. Regadenoson versus dipyridamole hyperemia for cardiac PET imaging.

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    Johnson, Nils P; Gould, K Lance

    2015-04-01

    The goal of this study was to compare regadenoson and dipyridamole hyperemia for quantitative myocardial perfusion imaging. Regadenoson is commonly used for stress perfusion imaging. However, no study in nuclear cardiology has employed a paired design to compare quantitative hyperemic flow from regadenoson to more traditional agents such as dipyridamole. Additionally, the timing of regadenoson bolus relative to tracer administration can be expected to affect quantitative flow. Subjects underwent 2 rest/stress cardiac positron emission tomography scans using an Rb-82 generator. Each scan employed dipyridamole and a second drug in random sequence, either regadenoson according to 5 timing sequences or repeated dipyridamole. A validated retention model quantified absolute flow and coronary flow reserve. A total of 176 pairs compared regadenoson (126 pairs, split unevenly among 5 timing sequences) or repeated dipyridamole (50 pairs). The cohort largely had few symptoms, only risk factors, and nearly normal relative uptake images, with 8% typical angina or dyspnea, 20% manifest coronary artery disease, and a minimum quadrant average of 80% (interquartile range: 76% to 83%) on dipyridamole scans. Hyperemic flow varied among regadenoson timing sequences but showed consistently lower stress flow and coronary flow reserve compared with dipyridamole. A timing sequence most similar to the regadenoson package insert achieved about 80% of dipyridamole hyperemia, whereas further delaying radiotracer injection reached approximately 90% of dipyridamole hyperemia. Because of the small numbers of pairs for each regadenoson timing protocol and a paucity of moderate or large perfusion defects, we did not observe a difference in relative uptake. With the standard timing protocol from the package insert, regadenoson achieved only 80% of dipyridamole hyperemia quantitatively imaged by cardiac positron emission tomography using Rb-82. A nonstandard protocol using a more delayed

  15. Enhancing ejection fraction measurement through 4D respiratory motion compensation in cardiac PET imaging

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    Tang, Jing; Wang, Xinhui; Gao, Xiangzhen; Segars, W. Paul; Lodge, Martin A.; Rahmim, Arman

    2017-06-01

    ECG gated cardiac PET imaging measures functional parameters such as left ventricle (LV) ejection fraction (EF), providing diagnostic and prognostic information for management of patients with coronary artery disease (CAD). Respiratory motion degrades spatial resolution and affects the accuracy in measuring the LV volumes for EF calculation. The goal of this study is to systematically investigate the effect of respiratory motion correction on the estimation of end-diastolic volume (EDV), end-systolic volume (ESV), and EF, especially on the separation of normal and abnormal EFs. We developed a respiratory motion incorporated 4D PET image reconstruction technique which uses all gated-frame data to acquire a motion-suppressed image. Using the standard XCAT phantom and two individual-specific volunteer XCAT phantoms, we simulated dual-gated myocardial perfusion imaging data for normally and abnormally beating hearts. With and without respiratory motion correction, we measured the EDV, ESV, and EF from the cardiac-gated reconstructed images. For all the phantoms, the estimated volumes increased and the biases significantly reduced with motion correction compared with those without. Furthermore, the improvement of ESV measurement in the abnormally beating heart led to better separation of normal and abnormal EFs. The simulation study demonstrated the significant effect of respiratory motion correction on cardiac imaging data with motion amplitude as small as 0.7 cm. The larger the motion amplitude the more improvement respiratory motion correction brought about on the EF measurement. Using data-driven respiratory gating, we also demonstrated the effect of respiratory motion correction on estimating the above functional parameters from list mode patient data. Respiratory motion correction has been shown to improve the accuracy of EF measurement in clinical cardiac PET imaging.

  16. Enhancing ejection fraction measurement through 4D respiratory motion compensation in cardiac PET imaging.

    Science.gov (United States)

    Tang, Jing; Wang, Xinhui; Gao, Xiangzhen; Paul Segars, W; Lodge, Martin A; Rahmim, Arman

    2017-06-07

    ECG gated cardiac PET imaging measures functional parameters such as left ventricle (LV) ejection fraction (EF), providing diagnostic and prognostic information for management of patients with coronary artery disease (CAD). Respiratory motion degrades spatial resolution and affects the accuracy in measuring the LV volumes for EF calculation. The goal of this study is to systematically investigate the effect of respiratory motion correction on the estimation of end-diastolic volume (EDV), end-systolic volume (ESV), and EF, especially on the separation of normal and abnormal EFs. We developed a respiratory motion incorporated 4D PET image reconstruction technique which uses all gated-frame data to acquire a motion-suppressed image. Using the standard XCAT phantom and two individual-specific volunteer XCAT phantoms, we simulated dual-gated myocardial perfusion imaging data for normally and abnormally beating hearts. With and without respiratory motion correction, we measured the EDV, ESV, and EF from the cardiac-gated reconstructed images. For all the phantoms, the estimated volumes increased and the biases significantly reduced with motion correction compared with those without. Furthermore, the improvement of ESV measurement in the abnormally beating heart led to better separation of normal and abnormal EFs. The simulation study demonstrated the significant effect of respiratory motion correction on cardiac imaging data with motion amplitude as small as 0.7 cm. The larger the motion amplitude the more improvement respiratory motion correction brought about on the EF measurement. Using data-driven respiratory gating, we also demonstrated the effect of respiratory motion correction on estimating the above functional parameters from list mode patient data. Respiratory motion correction has been shown to improve the accuracy of EF measurement in clinical cardiac PET imaging.

  17. Role of Cardiac PET in Clinical Practice.

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    Salata, Brian M; Singh, Parmanand

    2017-11-09

    Early identification of atherosclerosis and at-risk lesions plays a critical role in reducing the burden of cardiovascular disease. While invasive coronary angiography serves as the gold standard for diagnosing coronary artery disease, non-invasive imaging techniques provide visualization of both anatomical and functional atherosclerotic processes prior to clinical presentation. The development of cardiac positron emission tomography (PET) has greatly enhanced our capability to diagnose and treat patients with early stages of atherosclerosis. Cardiac PET is a powerful, versatile non-invasive diagnostic tool with utility in the identification of high-risk plaques, myocardial perfusion defects, and viable myocardial tissue. Cardiac PET allows for comparisons of myocardial function both at time of rest and stress, providing accurate assessments of both myocardial perfusion and viability. Furthermore, novel PET techniques with unique radiotracers yield clinically relevant data on high-risk plaques in active progressive atherosclerosis. While PET exercise stress tests were previously difficult to perform given short radiotracer half-life, the development of the novel radiotracer Flurpiridaz F-18 provides a promising future for PET exercise stress imaging. In addition, hybrid imaging with computed tomography angiography (CTA) and cardiac magnetic resonance (CMR) provides integration of cardiac function and structure. In this review article, we discuss the principles of cardiac PET, the clinical applications of PET in diagnosing and prognosticating patients at risk for future cardiovascular events, compare PET with other non-invasive cardiac imaging modalities, and discuss future applications of PET in CVD evaluation and management.

  18. Dual Respiratory and Cardiac Motion Estimation in PET Imaging: Methods Design and Quantitative Evaluation.

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    Feng, Tao; Wang, Jizhe; Tsui, Benjamin M W

    2018-02-05

    The goal of this study is to develop and evaluate four post-reconstruction respiratory and cardiac (R&C) motion vector field (MVF) estimation methods for cardiac 4D PET data. In Method 1, the dual R&C motions were estimated directly from the dual R&C gated images. In Methods 2, respiratory motion (RM) and cardiac motion (CM) were separately estimated from the respiratory gated only and cardiac gated only images. The effects of RM on CM estimation were modeled in Method 3 by applying an image-based RM correction on the cardiac gated images before CM estimation, the effects of CM on RM estimation were neglected. Methods 4 iteratively models the mutual effects of RM and CM during dual R&C motion estimations. Realistic simulation data were generated for quantitative evaluation of four methods. Almost noise-free PET projection data were generated from the 4D XCAT phantom with realistic R&C MVF using Monte Carlo simulation. Poisson noise was added to the scaled projection data to generate additional datasets of 2 more different noise levels. All the projection data were reconstructed using a 4D image reconstruction method to obtain dual R&C gated images. The four dual R&C MVF estimation methods were applied to the dual R&C gated images and the accuracy of motion estimation was quantitatively evaluated using the root mean square error (RMSE) of the estimated MVFs. Results show that among the 4 estimation methods, Methods 2 performed the worst for noise-free case while Method 1 performed the worst for noisy cases in terms of quantitative accuracy of the estimated MVF. Methods 4 and 3 showed comparable results and achieved RMSE lower by up to 35% than that in Method 1 for noisy cases. In conclusion, we have developed and evaluated 4 different post-reconstruction R&C MVF estimation methods for use in 4D PET imaging. Comparison of the performance of four methods on simulated data indicates separate R&C estimation with modeling of RM before CM estimation (Method 3) to be the

  19. Evaluation of accuracy and workflow between different alignment techniques for correction of CTAC and PET misalignment in cardiac PET-CT imaging

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    Philps, Elizabeth B.; Aivano, Sarah J.

    2007-03-01

    Small errors in the alignment between CT Attenuation Correction (CTAC) images and Positron Emission Tomography (PET) acquisitions can result in significant changes in PET attenuation corrected images. Misalignment due to respiratory or cardiac motion can produce mismatch between the PET and CTAC acquisitions. This contributes to artifactual hypoperfusion defects that are interpretable as myocardial ischemia or infarct. Correction for the misalignment between the PET and CTAC images can eliminate these false positive artifacts. Two methods for correcting for this respiratory and cardiac misalignment were compared. The first was an existing procedure, the manual-shift method, using point-to-point, in-plane, two-dimensional (2D) measurements of the shifts in axial, sagittal, and coronal planes. A new PET image reconstruction using the corrected attenuation map shifted by the 2D measurements was then performed. In the second method, the Interactive ACQC method, visual alignment was performed between the left ventricle boundaries on fused images and automated calculation of necessary rigid three-dimensional (3D) alignment parameters was performed. A new PET image reconstruction was then performed with an attenuation map shifted by the prescribed alignment parameters. The two methods were compared for accuracy and workflow efficiency using five cardiac PET/CT cases, scanned on GE Discovery VCT and Discovery ST systems. Alignment measurements using the visual alignment process (the interactive ACQC method) improved productivity by over five minutes, on average. The results show that the interactive ACQC procedure yields similar results to those of the point-to-point procedure while providing improved workflow for cardiac PET attenuation correction quality control.

  20. Direct reconstruction of cardiac PET kinetic parametric images using a preconditioned conjugate gradient approach.

    Science.gov (United States)

    Rakvongthai, Yothin; Ouyang, Jinsong; Guerin, Bastien; Li, Quanzheng; Alpert, Nathaniel M; El Fakhri, Georges

    2013-10-01

    Our research goal is to develop an algorithm to reconstruct cardiac positron emission tomography (PET) kinetic parametric images directly from sinograms and compare its performance with the conventional indirect approach. Time activity curves of a NCAT phantom were computed according to a one-tissue compartmental kinetic model with realistic kinetic parameters. The sinograms at each time frame were simulated using the activity distribution for the time frame. The authors reconstructed the parametric images directly from the sinograms by optimizing a cost function, which included the Poisson log-likelihood and a spatial regularization terms, using the preconditioned conjugate gradient (PCG) algorithm with the proposed preconditioner. The proposed preconditioner is a diagonal matrix whose diagonal entries are the ratio of the parameter and the sensitivity of the radioactivity associated with parameter. The authors compared the reconstructed parametric images using the direct approach with those reconstructed using the conventional indirect approach. At the same bias, the direct approach yielded significant relative reduction in standard deviation by 12%-29% and 32%-70% for 50 × 10(6) and 10 × 10(6) detected coincidences counts, respectively. Also, the PCG method effectively reached a constant value after only 10 iterations (with numerical convergence achieved after 40-50 iterations), while more than 500 iterations were needed for CG. The authors have developed a novel approach based on the PCG algorithm to directly reconstruct cardiac PET parametric images from sinograms, and yield better estimation of kinetic parameters than the conventional indirect approach, i.e., curve fitting of reconstructed images. The PCG method increases the convergence rate of reconstruction significantly as compared to the conventional CG method.

  1. Hybrid cardiac imaging: SPECT/CT and PET/CT. A joint position statement by the European Association of Nuclear Medicine (EANM), the European Society of Cardiac Radiology (ESCR) and the European Council of Nuclear Cardiology (ECNC)

    DEFF Research Database (Denmark)

    Flotats, Albert; Gutberlet, Matthias; Knuuti, Juhani

    2011-01-01

    improvement in the management of patients with cancer over stand-alone acquired CT and PET images. Hybrid cardiac imaging either with single photon emission computed tomography (SPECT) or PET combined with CT depicts cardiac and vascular anatomical abnormalities and their physiologic consequences in a single....... The European Association of Nuclear Medicine (EANM), the European Society of Cardiac Radiology (ESCR) and the European Council of Nuclear Cardiology (ECNC) in this paper want to present a position statement of the institutions on the current roles of SPECT/CT and PET/CT hybrid cardiac imaging in patients...

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

    DEFF Research Database (Denmark)

    Christensen, Nana Louise; Tolbod, Lars Poulsen

    Aim: Q.Clear reconstruction is expected to improve detection of perfusion defects in cardiac PET due to the high degree of image convergence and effective noise suppression. However, 82Rb (T½=76s) possess a special problem, since count statistics vary significantly not only between patients...... statistics using a cardiac PET phantom as well as a selection of clinical patients referred for 82Rb cardiac PET. Methods: The study consistent of 3 parts: 1) A thorax-cardiac phantom was scanned for 10 minutes after injection of 1110 MBq 82Rb. Frames at 3 different times after infusion were reconstructed...... to yield images with total number of prompts (TP) ranging from 4 to 40 MCnts. Contrast of defect-to-LV and LV-to-cavity were characterized at a range of beta factors. 2) Body Surface Area (BSA) and TP in static frames 2.5-5 min post 82Rb infusion (1110 MBq) was extracted from 75 consecutive clinical 82Rb...

  3. Dynamic cardiac PET imaging: extraction of time-activity curves using ICA and a generalized Gaussian distribution model.

    Science.gov (United States)

    Mabrouk, Rostom; Dubeau, François; Bentabet, Layachi

    2013-01-01

    Kinetic modeling of metabolic and physiologic cardiac processes in small animals requires an input function (IF) and a tissue time-activity curves (TACs). In this paper, we present a mathematical method based on independent component analysis (ICA) to extract the IF and the myocardium's TACs directly from dynamic positron emission tomography (PET) images. The method assumes a super-Gaussian distribution model for the blood activity, and a sub-Gaussian distribution model for the tissue activity. Our appreach was applied on 22 PET measurement sets of small animals, which were obtained from the three most frequently used cardiac radiotracers, namely: desoxy-fluoro-glucose ((18)F-FDG), [(13)N]-ammonia, and [(11)C]-acetate. Our study was extended to PET human measurements obtained with the Rubidium-82 ((82) Rb) radiotracer. The resolved mathematical IF values compare favorably to those derived from curves extracted from regions of interest (ROI), suggesting that the procedure presents a reliable alternative to serial blood sampling for small-animal cardiac PET studies.

  4. TU-G-BRA-08: BEST IN PHYSICS (JOINT IMAGING-THERAPY): Hybrid PET-MRI Imaging of Acute Radiation Induced Cardiac Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    El-Sherif, O; Xhaferllari, I; Gaede, S [Western Univeristy, London, ON (United Kingdom); London Regional Cancer Program, London, ON (United Kingdom); Sykes, J; Butler, J [Lawson Health Research Institute, London, ON (United Kingdom); Wisenberg, G; Prato, F [Western Univeristy, London, ON (United Kingdom); Lawson Health Research Institute, London, ON (United Kingdom)

    2015-06-15

    Purpose: To identify the presence of low-dose radiation induced cardiac toxicity in a canine model using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI). Methods: Research ethics board approval was obtained for a longitudinal imaging study of 5 canines after cardiac irradiation. Animals were imaged at baseline, 1 week post cardiac irradiation, and 1 month post cardiac irradiation using a hybrid PET- MRI system (Biograph mMR, Siemens Healthcare). The imaging protocol was designed to assess acute changes in myocardial perfusion and inflammation. Myocardial perfusion imaging was performed using N13-ammonia tracer followed by a dynamic PET acquisition scan. A compartmental tracer kinetic model was used for absolute perfusion quantification. Myocardial inflammation imaging was performed using F18-fluorodeoxyglucose (FDG) tracer. The standard uptake value (SUV) over a region encompassing the whole heart was used to compare FDG scans. All animals received a simulation CT scan (GE Medical Systems) for radiation treatment planning. Radiation treatment plans were created using the Pinncale3 treatment planning system (Philips Radiation Oncology Systems) and designed to resemble the typical cardiac exposure during left-sided breast cancer radiotherapy. Cardiac irradiations were performed in a single fraction using a TrueBeam linear accelerator (Varian Medical Systems). Results: The delivered dose (mean ± standard deviation) to heart was 1.8±0.2 Gy. Reductions in myocardial stress perfusion relative to baseline were observed in 2 of the 5 animals 1 month post radiation. A global inflammatory response 1 month post radiation was observed in 4 of the 5 animals. The calculated SUV at 1 month post radiation was significantly higher (p=0.05) than the baseline SUV. Conclusion: Low doses of cardiac irradiation (< 2 Gy) may lead to myocardial perfusion defects and a global inflammatory response that can be detectable as early as 1 month post irradiation

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

    Science.gov (United States)

    O' Doherty, Jim; Schleyer, Paul

    2017-12-01

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

  6. A three-dimensional model-based partial volume correction strategy for gated cardiac mouse PET imaging

    Science.gov (United States)

    Dumouchel, Tyler; Thorn, Stephanie; Kordos, Myra; DaSilva, Jean; Beanlands, Rob S. B.; deKemp, Robert A.

    2012-07-01

    Quantification in cardiac mouse positron emission tomography (PET) imaging is limited by the imaging spatial resolution. Spillover of left ventricle (LV) myocardial activity into adjacent organs results in partial volume (PV) losses leading to underestimation of myocardial activity. A PV correction method was developed to restore accuracy of the activity distribution for FDG mouse imaging. The PV correction model was based on convolving an LV image estimate with a 3D point spread function. The LV model was described regionally by a five-parameter profile including myocardial, background and blood activities which were separated into three compartments by the endocardial radius and myocardium wall thickness. The PV correction was tested with digital simulations and a physical 3D mouse LV phantom. In vivo cardiac FDG mouse PET imaging was also performed. Following imaging, the mice were sacrificed and the tracer biodistribution in the LV and liver tissue was measured using a gamma-counter. The PV correction algorithm improved recovery from 50% to within 5% of the truth for the simulated and measured phantom data and image uniformity by 5-13%. The PV correction algorithm improved the mean myocardial LV recovery from 0.56 (0.54) to 1.13 (1.10) without (with) scatter and attenuation corrections. The mean image uniformity was improved from 26% (26%) to 17% (16%) without (with) scatter and attenuation corrections applied. Scatter and attenuation corrections were not observed to significantly impact PV-corrected myocardial recovery or image uniformity. Image-based PV correction algorithm can increase the accuracy of PET image activity and improve the uniformity of the activity distribution in normal mice. The algorithm may be applied using different tracers, in transgenic models that affect myocardial uptake, or in different species provided there is sufficient image quality and similar contrast between the myocardium and surrounding structures.

  7. Respiratory gating in cardiac PET

    DEFF Research Database (Denmark)

    Lassen, Martin Lyngby; Rasmussen, Thomas; Christensen, Thomas E

    2017-01-01

    BACKGROUND: Respiratory motion due to breathing during cardiac positron emission tomography (PET) results in spatial blurring and erroneous tracer quantification. Respiratory gating might represent a solution by dividing the PET coincidence dataset into smaller respiratory phase subsets. The aim...... stress (82)RB-PET. Respiratory rates and depths were measured by a respiratory gating system in addition to registering actual respiratory rates. Patients undergoing adenosine stress showed a decrease in measured respiratory rate from initial to later scan phase measurements [12.4 (±5.7) vs 5.6 (±4.......7) min(-1), P PET...

  8. LMI1195 PET imaging in evaluation of regional cardiac sympathetic denervation and its potential role in antiarrhythmic drug treatment

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ming; Bozek, Jody; Lamoy, Melanie; Kagan, Mikhail; Benites, Pedro; Onthank, David; Robinson, Simon P. [Lantheus Medical Imaging, Discovery Research, N. Billerica, MA (United States)

    2012-12-15

    Regional cardiac sympathetic denervation (RCSD) associated with reduced noradrenaline transporter (NAT) function has been linked to cardiac arrhythmia. This study examined the association of LMI1195, an {sup 18}F-labeled NAT substrate developed for positron emission tomography (PET) imaging, with NAT in vitro, and its imaging to detect RCSD and guide antiarrhythmic drug treatment in vivo. LMI1195 association with NAT was assessed in comparison with other substrates, noradrenaline (NA) and {sup 123}I-metaiodobenzylguanidine (MIBG), in NAT-expressing cells. LMI1195 cardiac imaging was performed for evaluation of RCSD in a rabbit model surgically developed by regional phenol application on the left ventricular (LV) wall. The normal LV areas in images were quantified as regions with radioactivity {>=}50 % maximum. Potential impact of RCSD on dofetilide, an antiarrhythmic drug, induced ECG changes was assessed. NAT blockade with desipramine reduced LMI1195 cell uptake by 90 {+-} 3 %, similar to NA and MIBG. NA, MIBG, or self inhibited LMI1195 cell uptake concentration-dependently with comparable IC{sub 50} values (1.09, 0.21, and 0.90 {mu}M). LMI1195 cardiac imaging differentiated innervated and denervated areas in RCSD rabbits. The surgery resulted in a large denervated LV area at 2 weeks which was partially recovered at 12 weeks. Myocardial perfusion imaging with flurpiridaz F 18 showed normal perfusion in RCSD areas. Dofetilide induced more prominent QTc prolongation in RCSD than control animals. However, changes in heart rate were comparable. LMI1195 exhibits high association with NAT and can be used for imaging RCSD. The detected RCSD increases cardiac risks to the antiarrhythmic drug, dofetilide, by inducing more QTc prolongation. (orig.)

  9. Is metal artefact reduction mandatory in cardiac PET/CT imaging in the presence of pacemaker and implantable cardioverter defibrillator leads?

    Energy Technology Data Exchange (ETDEWEB)

    Ghafarian, Pardis [Shahid Beheshti University, Department of Radiation Medicine, Tehran (Iran, Islamic Republic of); Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Tehran University of Medical Sciences, Research Center for Science and Technology in Medicine, Tehran (Iran, Islamic Republic of); Aghamiri, S.M.R. [Shahid Beheshti University, Department of Radiation Medicine, Tehran (Iran, Islamic Republic of); Ay, Mohammad R. [Tehran University of Medical Sciences, Research Center for Science and Technology in Medicine, Tehran (Iran, Islamic Republic of); Tehran University of Medical Sciences, Department of Medical Physics and Biomedical Engineering, Tehran (Iran, Islamic Republic of); Tehran University of Medical Sciences, Research Institute for Nuclear Medicine, Tehran (Iran, Islamic Republic of); Rahmim, Arman [Johns Hopkins University, Department of Radiology, Baltimore, MD (United States); Schindler, Thomas H. [Geneva University, Cardiovascular Center, Nuclear Cardiology, Geneva (Switzerland); Ratib, Osman [Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland)

    2011-02-15

    Cardiac PET/CT imaging is often performed in patients with pacemakers and implantable cardioverter defibrillator (ICD) leads. However, metallic implants usually produce artefacts on CT images which might propagate to CT-based attenuation-corrected (CTAC) PET images. The impact of metal artefact reduction (MAR) for CTAC of cardiac PET/CT images in the presence of pacemaker, ICD and ECG leads was investigated using both qualitative and quantitative analysis in phantom and clinical studies. The study included 14 patients with various leads undergoing perfusion and viability examinations using dedicated cardiac PET/CT protocols. The PET data were corrected for attenuation using both artefactual CT images and CT images corrected using the MAR algorithm. The severity and magnitude of metallic artefacts arising from these leads were assessed on both linear attenuation coefficient maps ({mu}-maps) and attenuation-corrected PET images. CT and PET emission data were obtained using an anthropomorphic thorax phantom and a dedicated heart phantom made in-house incorporating pacemaker and ICD leads attached at the right ventricle of the heart. Volume of interest-based analysis and regression plots were performed for regions related to the lead locations. Bull's eye view analysis was also performed on PET images corrected for attenuation with and without the MAR algorithm. In clinical studies, the visual assessment of PET images by experienced physicians and quantitative analysis did not reveal erroneous interpretation of the tracer distribution or significant differences when PET images were corrected for attenuation with and without MAR. In phantom studies, the mean differences between tracer uptake obtained without and with MAR were 10.16{+-}2.1% and 6.86{+-}2.1% in the segments of the heart in the vicinity of metallic ICD or pacemaker leads, and were 4.43{+-}0.5% and 2.98{+-}0.5% in segments far from the leads. Although the MAR algorithm was able to effectively improve

  10. Cardiac-gated parametric images from82Rb PET from dynamic frames and direct 4D reconstruction.

    Science.gov (United States)

    Germino, Mary; Carson, Richard E

    2018-02-01

    Cardiac perfusion PET data can be reconstructed as a dynamic sequence and kinetic modeling performed to quantify myocardial blood flow, or reconstructed as static gated images to quantify function. Parametric images from dynamic PET are conventionally not gated, to allow use of all events with lower noise. An alternative method for dynamic PET is to incorporate the kinetic model into the reconstruction algorithm itself, bypassing the generation of a time series of emission images and directly producing parametric images. So-called "direct reconstruction" can produce parametric images with lower noise than the conventional method because the noise distribution is more easily modeled in projection space than in image space. In this work, we develop direct reconstruction of cardiac-gated parametric images for 82 Rb PET with an extension of the Parametric Motion compensation OSEM List mode Algorithm for Resolution-recovery reconstruction for the one tissue model (PMOLAR-1T). PMOLAR-1T was extended to accommodate model terms to account for spillover from the left and right ventricles into the myocardium. The algorithm was evaluated on a 4D simulated 82 Rb dataset, including a perfusion defect, as well as a human 82 Rb list mode acquisition. The simulated list mode was subsampled into replicates, each with counts comparable to one gate of a gated acquisition. Parametric images were produced by the indirect (separate reconstructions and modeling) and direct methods for each of eight low-count and eight normal-count replicates of the simulated data, and each of eight cardiac gates for the human data. For the direct method, two initialization schemes were tested: uniform initialization, and initialization with the filtered iteration 1 result of the indirect method. For the human dataset, event-by-event respiratory motion compensation was included. The indirect and direct methods were compared for the simulated dataset in terms of bias and coefficient of variation as a

  11. SU-D-217A-05: Auto-Registration of Cardiac PET/CT Images with a 3D Weighted Gradient Correlation Algorithm.

    Science.gov (United States)

    Ai, H; Pan, T

    2012-06-01

    To design a novel 3D automatic registration algorithm for cardiac PET/CT registration using gradient information and to evaluate the performance of the algorithm with clinical PET/CT datasets. The 512×512×47 CT images are at first resized to 128×128×47 to match the matrix size of PET. In order to maximize the gradient information at boundaries in CT, a conventional fuzzy c-means clustering algorithm (number of cluster = 7) is implemented to suppress signals from tissues that do not contribute much useful information for the registration purpose (fat, lung, and bones). The 3D Image gradient map, consisting of all three orthogonal components, is derived from the PET images and the post- clustering CT images. The mis-registration is modeled as 3D rigid body translation in this study, though it can be extended to include rotations as well. The details of the gradient-based objective function are described in the support document. Optimal registration is determined by searching for the maximum of the objective function over a range of potential translation positions (e.g. 8.2×8.2×2.8cm). This process is repeated at a higher matrix size (512×512×47) to refine the result of registration. We applied this auto registration technique on 55 patient data sets of cardiac PET/CT images. The CT images were average-CT images, and the PET images were without attenuation correction. 54 out of the 55 cases produced satisfactory registration. The proposed weighted gradient correlation algorithm is a viable solution for auto registration of cardiac PET/CT images. More work is needed to further improve the robustness of thealgorithm. © 2012 American Association of Physicists in Medicine.

  12. Evaluation of the clinical efficacy of the PeTrack motion tracking system for respiratory gating in cardiac PET imaging

    Science.gov (United States)

    Manwell, Spencer; Chamberland, Marc J. P.; Klein, Ran; Xu, Tong; deKemp, Robert

    2017-03-01

    Respiratory gating is a common technique used to compensate for patient breathing motion and decrease the prevalence of image artifacts that can impact diagnoses. In this study a new data-driven respiratory gating method (PeTrack) was compared with a conventional optical tracking system. The performance of respiratory gating of the two systems was evaluated by comparing the number of respiratory triggers, patient breathing intervals and gross heart motion as measured in the respiratory-gated image reconstructions of rubidium-82 cardiac PET scans in test and control groups consisting of 15 and 8 scans, respectively. We found evidence suggesting that PeTrack is a robust patient motion tracking system that can be used to retrospectively assess patient motion in the event of failure of the conventional optical tracking system.

  13. Alignment of 3-dimensional cardiac structures in O-15-labeled water PET emission images with mutual information.

    Science.gov (United States)

    Juslin, Anu; Lötjönen, Jyrki; Nesterov, Sergey V; Kalliokoski, Kari; Knuuti, Juhani; Ruotsalainen, Ulla

    2007-01-01

    The aim of this study was to develop a method to correct the heart position between two oxygen 15-labeled water cardiac positron emission tomography (PET) image sets to be able to use the equivalent regions of interest for the quantification of the perfusion values in the same myocardial segments. Independent component analysis was applied to the dynamic image sets (simulated phantom and 6 rest-pharmacologic stress and 10 rest-rest image sets of healthy female volunteers) acquired at different time points to separate the cardiac structures (ventricles and myocardium). The separated component images from independent component analysis from the 2 studies of the same individual were aligned with a normalized mutual information-based registration method. The alignment parameters were applied to position the regions of interest in the floating image sets for calculation of the myocardial blood flow values. In the rest case the mean myocardial blood flow value was 0.76 +/- 0.12 mL x g(-1) x min(-1) for the manual method and 0.79 +/- 0.10 mL x g(-1) x min(-1) for the proposed method (by use of the right ventricle component in the alignment), and in the stress case these values were 3.39 +/- 0.70 mL x g(-1) x min(-1) and 4.01 +/- 0.71 mL x g(-1) x min(-1), respectively. No statistically significant difference was found between the methods. In the tests with the phantom and patient images the alignment of cardiac structures was shown to be successful. The alignment could be done without the use of information from the myocardial compartment.

  14. Synthesis of two optically active calcium channel antagonists labelled with carbon-11 for in vivo cardiac PET imaging.

    Science.gov (United States)

    Dollé, F; Hinnen, F; Valette, H; Fuseau, C; Duval, R; Péglion, J L; Crouzel, C

    1997-04-01

    (+/-)-S11568 (1, 3-ethyl-5-methyl-(+/-)-2-[(2-(2-aminoethoxy)ethoxy) methyl]-4-(2,3-dichlorophenyl)-6-methyl-1,4-dihydropyridine-3, 5-dicarboxylate), has an in vitro profile of high potency and of high selectivity for the low-voltage dependent. L-type calcium channel. In in vitro binding studies, it displaced specifically bound (-)-[3H]PN 200-110 (isradipine (2), the reference molecule for in vitro studies) from cardiac and vascular smooth muscle preparations with potencies of 5.6 and 51 nM, respectively. It also appears as a pure pharmacological antagonist acting at a single channel L-type and free of any interaction at the benzothiazepine binding site such as amlodipine (3). Both enantiomers of S11568 have in vitro activities, the dextro isomer S12967 ((+)-1) being 6 to 18-fold less potent than the levo one S12968 ((-)-1). Two couples of optically active labelling precursors of S11568, ((-)-10/(+)-10 and (-)-14/(+)-14) have been synthesized using a modified Hantzsch's dihydropyridine synthesis. In both cases, the enantiomers were separated by preparative chiral HPLC. They both have been independently labelled with carbon-11, using [11C]diazomethane or [11C]iodomethane to give multimilliCurie quantities of (-)-1 (S12968) and (+)-1 (S12967) with high specific activities (500-1000 mCi/mumol, 18.5-37.0 GBq/mumol). Both enantiomers appear suitable for PET experiments: their myocardial concentration increases after a bolus injection to reach a maximum in 2 min and then remains on a plateau with a slight downslope while the blood concentration falls rapidly. Myocardial uptake was threefold higher than lung uptake, leading to a good contrast on PET images. The present preliminary biological results obtained in Beagle dogs showed that both enantiomers have similar myocardial kinetics and in vivo affinity for the left ventricular myocardium.

  15. Evaluation of attenuation correction in cardiac PET using PET/MR.

    Science.gov (United States)

    Lau, Jeffrey M C; Laforest, R; Sotoudeh, H; Nie, X; Sharma, S; McConathy, J; Novak, E; Priatna, A; Gropler, R J; Woodard, P K

    2017-06-01

    Simultaneous acquisition Positron emission tomography/magnetic resonance (PET/MR) is a new technology that has potential as a tool both in research and clinical diagnosis. However, cardiac PET acquisition has not yet been validated using MR imaging for attenuation correction (AC). The goal of this study is to evaluate the feasibility of PET imaging using a standard 2-point Dixon volume interpolated breathhold examination (VIBE) MR sequence for AC. Evaluation was performed in both phantom and patient data. A chest phantom containing heart, lungs, and a lesion insert was scanned by both PET/MR and PET/CT. In addition, 30 patients underwent whole-body 18F-fluorodeoxyglucose PET/CT followed by simultaneous cardiac PET/MR. Phantom study showed 3% reduction of activity values in the myocardium due to the non-inclusion of the phased array coil in the AC. In patient scans, average standardized uptake values (SUVs) obtained by PET/CT and PET/MR showed no significant difference (n = 30, 4.6 ± 3.5 vs 4.7 ± 2.8, P = 0.47). There was excellent per patient correlation between the values acquired by PET/CT and PET/MR (R 2 = 0.97). Myocardial SUVs PET imaging using MR for AC shows excellent correlation with myocardial SUVs obtained by standard PET/CT imaging. The 2-point Dixon VIBE MR technique can be used for AC in simultaneous PET/MR data acquisition.

  16. Cine CT for Attenuation Correction in Cardiac PET/CT

    Science.gov (United States)

    Alessio, Adam M.; Kohlmyer, Steve; Branch, Kelley; Chen, Grace; Caldwell, James; Kinahan, Paul

    2008-01-01

    In dual-modality PET/CT systems, the CT scan provides the attenuation map for PET attenuation correction. The current clinical practice of obtaining a single helical CT scan provides only a snapshot of the respiratory cycle, whereas PET occurs over multiple respiratory cycles. Misalignment of the attenuation map and emission image because of respiratory motion causes errors in the attenuation correction factors and artifacts in the attenuation-corrected PET image. To rectify this problem, we evaluated the use of cine CT, which acquires multiple low-dose CT images during a respiratory cycle. We evaluated the average and the intensity-maximum image of cine CT for cardiac PET attenuation correction. Methods Cine CT data and cardiac PET data were acquired from a cardiac phantom and from multiple patient studies. The conventional helical CT, cine CT, and PET data of an axially translating phantom were evaluated with and without respiratory motion. For the patient studies, we acquired 2 cine CT studies for each PET acquisition in a rest–stress 13N-ammonia protocol. Three readers visually evaluated the alignment of 74 attenuation image sets versus the corresponding emission image and determined whether the alignment provided acceptable or unacceptable attenuation-corrected PET images. Results In the phantom study, the attenuation correction from helical CT caused a major artifactual defect in the lateral wall on the PET image. The attenuation correction from the average and from the intensity-maximum cine CT images reduced the defect by 20% and 60%, respectively. In the patient studies, 77% of the cases using the average of the cine CT images had acceptable alignment and 88% of the cases using the intensity maximum of the cine CT images had acceptable alignment. Conclusion Cine CT offers an alternative to helical CT for compensating for respiratory motion in the attenuation correction of cardiac PET studies. Phantom studies suggest that the average and the intensity

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

    Science.gov (United States)

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

    2014-07-01

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

  18. Metabolic imaging using PET

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Takashi [University of Fukui, Biomedical Imaging Research Center, Eiheiji-cho, Fukui (Japan)

    2007-06-15

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

  19. Respiratory gating in cardiac PET: Effects of adenosine and dipyridamole.

    Science.gov (United States)

    Lassen, Martin Lyngby; Rasmussen, Thomas; Christensen, Thomas E; Kjær, Andreas; Hasbak, Philip

    2017-12-01

    Respiratory motion due to breathing during cardiac positron emission tomography (PET) results in spatial blurring and erroneous tracer quantification. Respiratory gating might represent a solution by dividing the PET coincidence dataset into smaller respiratory phase subsets. The aim of our study was to compare the resulting imaging quality by the use of a time-based respiratory gating system in two groups administered either adenosine or dipyridamole as the pharmacological stress agent. Forty-eight patients were randomized to adenosine or dipyridamole cardiac stress 82RB-PET. Respiratory rates and depths were measured by a respiratory gating system in addition to registering actual respiratory rates. Patients undergoing adenosine stress showed a decrease in measured respiratory rate from initial to later scan phase measurements [12.4 (±5.7) vs 5.6 (±4.7) min-1, P respiratory gating compared to dipyridamole (47% vs 71%, P = .12). As a result, imaging quality was superior in the dipyridamole group compared to adenosine. If respiratory gating is considered for use in cardiac PET, a dipyridamole stress protocol is recommended as it, compared to adenosine, causes a more uniform respiration and results in a higher frequency of successful respiratory gating and thereby superior imaging quality.

  20. PET imaging in multiple sclerosis

    NARCIS (Netherlands)

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

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

  1. Comparison of volumetric and functional parameters in simultaneous cardiac PET/MR: feasibility of volumetric assessment with residual activity from prior PET/CT.

    Science.gov (United States)

    Lücke, C; Oppolzer, B; Werner, P; Foldyna, B; Lurz, P; Jochimsen, T; Brenneis, B; Lehmkuhl, L; Sattler, B; Grothoff, M; Barthel, H; Sabri, O; Gutberlet, M

    2017-12-01

    To compare cardiac left ventricular (LV) parameters in simultaneously acquired hybrid fluorine-18-fluorodeoxyglucose ([18F] FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) in patients with residual tracer activity of upstream PET/CT. Twenty-nine patients (23 men, age 58±17 years) underwent cardiac PET/MRI either directly after a non-cardiac PET/CT with homogenous cardiac [18F] FDG uptake (n=20) or for viability assessment (n=9). Gated cardiac [18F] FDG PET and cine MR sequences were acquired simultaneously and evaluated blinded to the cross-imaging results. Image quality (IQ), end-diastolic (LVEDV), end-systolic volume (LVESV), ejection fraction (LVEF) and myocardial mass (LVMM) were measured. Pearson correlation and intraclass correlation coefficient (ICC), regression and a Bland-Altman analysis were assessed. Except LVMM, volumetric and functional LV parameters demonstrated high correlations (LVESV: r=0.97, LVEDV: r=0.95, LVEF: r=0.91, LVMM: r=0.87, each pPET-IQ (0-3) was high (mean: 2.2±0.9) with significant influence on LVMM calculations only. In simultaneously acquired cardiac PET/MRI data, LVEDV, LVESV and LVEF show good agreement. However, the agreement seems to be limited if cardiac PET/MRI follows PET/CT and only the residual activity is used. • [ 18 F] FDG PET-MRI is feasible with residual [ 18 F] FDG activity in patients with homogenous cardiac uptake. • Cardiac volumes and function assessed by PET/MRI show good agreement. • LVEDV and LVESV are underestimated; PET overestimates LVMM and LVEF. • Cardiac PET and MRI data correlate better when acquired simultaneously than sequentially. • PET and MRI should not assess LV parameters interchangeably.

  2. Breast PET/MR Imaging.

    Science.gov (United States)

    Melsaether, Amy; Moy, Linda

    2017-05-01

    Breast and whole-body PET/MR imaging is being used to detect local and metastatic disease and is being investigated for potential imaging biomarkers, which may eventually help personalize treatments and prognoses. This article provides an overview of breast and whole-body PET/MR exam techniques, summarizes PET and MR breast imaging for lesion detection, outlines investigations into multi-parametric breast PET/MR, looks at breast PET/MR in the setting of neo-adjuvant chemotherapy, and reviews the pros and cons of whole-body PET/MR in the setting of metastatic or suspected metastatic breast cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Measuring cardiac efficiency using PET/MRI

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, Grand [Lawrence Berkeley National Laboratory (United States); Aparici, Carina Mari; Brooks, Gabriel [University of California San Francisco (United States); Liu, Jing; Guccione, Julius; Saloner, David; Seo, Adam Youngho; Ordovas, Karen Gomes [Lawrence Berkeley National Laboratory (United States)

    2015-05-18

    Heart failure (HF) is a complex syndrome that is projected by the American Heart Association to cost $160 billion by 2030. In HF, significant metabolic changes and structural remodeling lead to reduced cardiac efficiency. A normal heart is approximately 20-25% efficient measured by the ratio of work to oxygen utilization (1 ml oxygen = 21 joules). The heart requires rapid production of ATP where there is complete turnover of ATP every 10 seconds with 90% of ATP produced by mitochondrial oxidative metabolism requiring substrates of approximately 30% glucose and 65% fatty acids. In our preclinical PET/MRI studies in normal rats, we showed a negative correlation between work and the influx rate constant for 18FDG, confirming that glucose is not the preferred substrate at rest. However, even though fatty acid provides 9 kcal/gram compared to 4 kcal/gram for glucose, in HF the preferred energy source is glucose. PET/MRI offers the potential to study this maladapted mechanism of metabolism by measuring work in a region of myocardial tissue simultaneously with the measure of oxygen utilization, glucose, and fatty acid metabolism and to study cardiac efficiency in the etiology of and therapies for HF. MRI is used to measure strain and a finite element mechanical model using pressure measurements is used to estimate myofiber stress. The integral of strain times stress provides a measure of work which divided by energy utilization, estimated by the production of 11CO2 from intravenous injection of 11C-acetate, provides a measure of cardiac efficiency. Our project involves translating our preclinical research to the clinical application of measuring cardiac efficiency in patients. Using PET/MRI to develop technologies for studying myocardial efficiency in patients, provides an opportunity to relate cardiac work of specific tissue regions to metabolic substrates, and measure the heterogeneity of LV efficiency.

  4. Feasibility of simultaneous PET-MR perfusion using a novel cardiac perfusion phantom

    OpenAIRE

    O'Doherty, James; SAMMUT, EVA; Schleyer, Paul; Stirling, James; Nazir, Muhummad Sohaib; Marsden, Paul K.; Chiribiri, Amedeo

    2017-01-01

    Background: PET-MR scanners are beginning to be employed for quantitative myocardial perfusion imaging. In order to examine simultaneous perfusion calculations, this work describes a feasibility study of simultaneous PET-MR of gadolinium-based contrast agent (GBCA) and PET radiotracer in a novel cardiac perfusion phantom. Results: [18F]F- and GBCA were injected simultaneously into a cardiac phantom using a range of ground-truth myocardial perfusion rates of 1 to 5 ml/g/min. PET quantification...

  5. Initial Experience With Simultaneous 18F-FDG PET/MRI in the Evaluation of Cardiac Sarcoidosis and Myocarditis.

    Science.gov (United States)

    Hanneman, Kate; Kadoch, Michael; Guo, Henry H; Jamali, Mehran; Quon, Andrew; Iagaru, Andrei; Herfkens, Robert

    2017-07-01

    The purpose of this study was to compare combined PET/MRI with PET/CT and cardiac MRI in the evaluation of cardiac sarcoidosis and myocarditis. Ten patients (4 men and 6 women; 56.1 ± 9.6 years old) were prospectively enrolled for evaluation of suspected cardiac sarcoidosis or myocarditis. Written informed consent was obtained. Following administration of 9.9 ± 0.9 mCi F-FDG, patients underwent standard cardiac PET/CT followed by combined PET/MRI using a simultaneous 3-T scanner. Cardiac MRI sequences included ECG-triggered cine SSFP, T2-weighted, and late gadolinium-enhanced imaging. Myocardial involvement was assessed with separate analysis of combined PET/MRI, PET/CT, and cardiac MRI data using dedicated postprocessing software. Estimates of radiation dose were derived from the applied doses of F-FDG and CT protocol parameters. Imaging was acquired with a delay from F-FDG injection of 90.2 ± 27.4 minutes for PET/CT and 207.7 ± 40.3 minutes for PET/MRI. Total scan time for PET/MRI was significantly longer than for PET/CT (81.4 ± 14.8 vs 12.0 minutes, P PET/MRI compared with PET/CT (6.9 ± 0.6 vs 8.2 ± 1.1 mSv, P = 0.007). There was no significant difference in the number of positive cases identified between combined PET/MRI (n = 10 [100%]), PET/CT (n = 6 [60%]), and cardiac MRI (n = 8 [80%]), P = 0.091. Simultaneous cardiac PET/MRI is feasible in the evaluation of cardiac sarcoidosis and myocarditis achieving diagnostic image quality.

  6. Simultaneous PET and MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yiping Shao; Cherry, Simon R.; Meadors, Ken; Siegel, Stefan; Silverman, Robert W. [Crump Institute for Biological Imaging, Department of Molecular and Medical Pharmacology, 10833 Le Conte Avenue, UCLA School of Medicine, Los Angeles, CA 90095 (United States); Farahani, Keyvan [Department of Radiological Sciences, 10833 Le Conte Avenue, UCLA School of Medicine, Los Angeles, CA 90095 (United States); Marsden, Paul K. [Guy' s and St Thomas' Clinical PET Centre, Division of Radiological Sciences, UMDS, London (United Kingdom)

    1997-10-01

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

  7. Imaging for cardiac electrophysiology

    Directory of Open Access Journals (Sweden)

    Benoit Desjardins

    2016-11-01

    Full Text Available Clinical cardiac electrophysiology is the study of the origin and treatment of arrhythmia. There has been considerable recent development in this field, where imaging has had a transformational impact. In this invited review, we offer a global overview of the most important developments in the use of imaging in cardiac electrophysiology. We first describe the radiological imaging modalities involved in cardiac electrophysiology, to assess cardiac anatomy, function and scar. We then introduce an imaging modality with which readers are probably unfamiliar (electroanatomical mapping [EAM], but which is routinely used by electrophysiologists to plan and guide cardiac mapping and cardiac ablation therapy by catheter, a therapy which can reduce or even cure arrhythmia. We identify the limitations of EAM and describe how radiological imaging modalities can complement this technique. We then describe and illustrate how imaging has helped the diagnosis of arrhythmogenic conditions, and how imaging is used to plan and guide clinical cardiac electrophysiologic procedures and assess their results and complications. We focus on the two most common arrhythmias for which imaging has the greatest impact: atrial fibrillation and ventricular tachycardia.

  8. Cardiac imaging in adults

    Energy Technology Data Exchange (ETDEWEB)

    Jaffe, C.C.

    1987-01-01

    This book approaches adult cardiac disease from the correlative imaging perspective. It includes chest X-rays and angiographs, 2-dimensional echocardiograms with explanatory diagrams for clarity, plus details on digital radiology, nuclear medicine techniques, CT and MRI. It also covers the normal heart, valvular heart disease, myocardial disease, pericardial disease, bacterial endocarditis, aortic aneurysm, cardiac tumors, and congenital heart disease of the adult. It points out those aspects where one imaging technique has significant superiority.

  9. Effectiveness of prolonged fasting 18f-FDG PET-CT in the detection of cardiac sarcoidosis.

    Science.gov (United States)

    Langah, Rumman; Spicer, Kenneth; Gebregziabher, Mulugeta; Gordon, Leonie

    2009-01-01

    The Japanese Ministry of Health and Welfare guidelines (JMHWG) are currently the standard used to diagnose cardiac sarcoidosis. JMHWG incorporate (67)Gallium scintigraphy as a minor criterion, while fasting (18)fluorine-2-fluoro-2-deoxy-D-glucose (FDG) PET is not included. As there is no published data comparing the accuracy of prolonged fasting FDG PET-CT (PF-PET) and Gallium scintigraphy for detecting active cardiac sarcoidosis, we sought to compare these two modalities. We retrospectively reviewed medical records and nuclear images of 76 patients with suspected cardiac sarcoid who had either PF-PET or Gallium scintigraphy between January 2004 and August 2008. Eleven patients were excluded due to inadequate fasting for PF-PET, incomplete records or diagnosis other than sarcoid. Cardiac catheterizations, electrocardiogram interpretations, echocardiography reports, pathology reports, therapeutic interventions, and follow-up findings were correlated to PF-PET and Gallium scintigraphy results. Nuclear images of all patients including controls were reviewed independently by two experienced nuclear physicians blinded to results. Using JMHWG as reference standard, sensitivity, specificity, and accuracy of PF-PET were 85%, 90%, and 86.7% and for Gallium scintigraphy were 15%, 80%, and 42.8%. Relative to Gallium scintigraphy, PF-PET appears to provide greater accuracy for detecting cardiac sarcoidosis. Our findings also highlight the importance of revising JMHWG to incorporate PF-PET and the importance of adequate prolonged fasting prior to FDG PET imaging.

  10. Cardiac magnetic resonance imaging

    African Journals Online (AJOL)

    2011-03-06

    Mar 6, 2011 ... Bruce Spottiswoode has a BSc in Electrical Engineering from the University of the Witwatersrand and a PhD in Biomedical Engineering on cardiac MRI from the. University of Cape Town. He has worked on developing electronics for the CSIR, on MRI image reconstruction for Siemens, and on X-ray imaging ...

  11. 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.

  12. 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

  13. PET/MR Imaging in Gynecologic Oncology.

    Science.gov (United States)

    Ohliger, Michael A; Hope, Thomas A; Chapman, Jocelyn S; Chen, Lee-May; Behr, Spencer C; Poder, Liina

    2017-08-01

    MR imaging and PET using 2-Deoxy-2-[18F]fluoroglucose (FDG) are both useful in the evaluation of gynecologic malignancies. MR imaging is superior for local staging of disease whereas fludeoxyglucose FDG PET is superior for detecting distant metastases. Integrated PET/MR imaging scanners have great promise for gynecologic malignancies by combining the advantages of each modality into a single scan. This article reviews the technology behind PET/MR imaging acquisitions and technical challenges relevant to imaging the pelvis. A dedicated PET/MR imaging protocol; the roles of PET and MR imaging in cervical, endometrial, and ovarian cancers; and future directions for PET/MR imaging are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2017-12-01

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

  15. PET and SPET tracers for mapping the cardiac nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Oliver; Halldin, Christer [Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institute, Karolinska Hospital, 17176 Stockholm (Sweden)

    2002-03-01

    The human cardiac nervous system consists of a sympathetic and a parasympathetic branch with (-)-norepinephrine and acetylcholine as the respective endogenous neurotransmitters. Dysfunction of the cardiac nervous system is implicated in various types of cardiac disease, such as heart failure, myocardial infarction and diabetic autonomic neuropathy. In vivo assessment of the distribution and function of cardiac sympathetic and parasympathetic neurones with positron emission tomography (PET) and single-photon emission tomography (SPET) can be achieved by means of a number of carbon-11-, fluorine-18-, bromine-76- and iodine-123-labelled tracer molecules. Available tracers for mapping sympathetic neurones can be divided into radiolabelled catecholamines, such as 6-[{sup 18}F]fluorodopamine, (-)-6-[{sup 18}F]fluoronorepinephrine and (-)-[{sup 11}C]epinephrine, and radiolabelled catecholamine analogues, such as [{sup 123}I]meta-iodobenzylguanidine, [{sup 11}C]meta-hydroxyephedrine, [{sup 18}F]fluorometaraminol, [{sup 11}C]phenylephrine and meta-[{sup 76}Br]bromobenzylguanidine. Resistance to metabolism by monoamine oxidase and catechol-O-methyl transferase simplifies the myocardial kinetics of the second group. Both groups of compounds are excellent agents for an overall assessment of sympathetic innervation. Biomathematical modelling of tracer kinetics is complicated by the complexity of the steps governing neuronal uptake, retention and release of these agents as well as by their high neuronal affinity, which leads to partial flow dependence of uptake. Mapping of cardiac parasympathetic neurones is limited by a low density and focal distribution pattern of these neurones in myocardium. Available tracers are derivatives of vesamicol, a molecule that binds to a receptor associated with the vesicular acetylcholine transporter. Compounds like (-)-[{sup 18}F]fluoroethoxybenzovesamicol display a high degree of non-specific binding in myocardium which restricts their utility

  16. 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.

  17. MR-based attenuation correction for cardiac FDG PET on a hybrid PET/MRI scanner: comparison with standard CT attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Vontobel, Jan; Liga, Riccardo; Possner, Mathias; Clerc, Olivier F.; Mikulicic, Fran; Veit-Haibach, Patrick; Voert, Edwin E.G.W. ter; Fuchs, Tobias A.; Stehli, Julia; Pazhenkottil, Aju P.; Benz, Dominik C.; Graeni, Christoph; Gaemperli, Oliver; Herzog, Bernhard; Buechel, Ronny R.; Kaufmann, Philipp A. [University Hospital Zurich, Department of Nuclear Medicine, Zurich (Switzerland)

    2015-09-15

    The aim of this study was to evaluate the feasibility of attenuation correction (AC) for cardiac {sup 18}F-labelled fluorodeoxyglucose (FDG) positron emission tomography (PET) using MR-based attenuation maps. We included 23 patients with no known cardiac history undergoing whole-body FDG PET/CT imaging for oncological indications on a PET/CT scanner using time-of-flight (TOF) and subsequent whole-body PET/MR imaging on an investigational hybrid PET/MRI scanner. Data sets from PET/MRI (with and without TOF) were reconstructed using MR AC and semi-quantitative segmental (20-segment model) myocardial tracer uptake (per cent of maximum) and compared to PET/CT which was reconstructed using CT AC and served as standard of reference. Excellent correlations were found for regional uptake values between PET/CT and PET/MRI with TOF (n = 460 segments in 23 patients; r = 0.913; p < 0.0001) with narrow Bland-Altman limits of agreement (-8.5 to +12.6 %). Correlation coefficients were slightly lower between PET/CT and PET/MRI without TOF (n = 460 segments in 23 patients; r = 0.851; p < 0.0001) with broader Bland-Altman limits of agreement (-12.5 to +15.0 %). PET/MRI with and without TOF showed minimal underestimation of tracer uptake (-2.08 and -1.29 %, respectively), compared to PET/CT. Relative myocardial FDG uptake obtained from MR-based attenuation corrected FDG PET is highly comparable to standard CT-based attenuation corrected FDG PET, suggesting interchangeability of both AC techniques. (orig.)

  18. Musculoskeletal imaging using fluoride PET.

    Science.gov (United States)

    Fischer, Dorothee Rita

    2013-11-01

    The convenience of (18)F-fluoride imaging is undeniable both because of its favorable tracer and because of its technical characteristics, including high image quality and short examination times leading to increased patient comfort. Depending on the activity administered, the radiation dose to patients is about comparable to higher using (18)F-fluoride for bone imaging compared with conventional scintigraphy using 99mTc-methylene diphosphonate. In times of molybdenum shortage, (18)F-fluoride represents a good alternative to 99mTc-based bone tracers. Besides malignant skeletal disease(18)F-fluoride PET/CT has in the last decade been investigated in a variety of non-oncologic musculoskeletal disorders of all parts of the skeleton. Studies included imaging of the skull with a special focus on bisphosphonate-induced osteonecrosis of the jaw in patients treated with bisphosphonates due to benign or malignant bone changes. Further studies evaluated the appendicular skeleton with emphasis on postsurgical changes including patients after knee and hip surgery and patients having received bone grafts of their limbs. Also, therapeutic effect of (18)F-fluoride PET/CT on patients with unclear foot pain was investigated. Finally imaging of the axial skeleton was analyzed including patients with ankylosing spondylitis and with Paget disease as well as patients after spine surgery including assessment of cage incorporation after cervical and lumbar spine fusion surgery. Furthermore, children suspected of child abuse as well as young patients with back pain were investigated by either (18)F-fluoride PET or PET/CT. Regarding its favorable technical aspects as well as study results presented, it is imaginable that (18)F-fluoride PET/(CT) will be increasingly used for non-oncologic musculoskeletal imaging in the future either as an adjunct or alternative to so far established imaging modalities and seems to be promising regarding decision making in the therapeutic management of

  19. Four Dimensional Cardiac Imaging

    Science.gov (United States)

    Smith, L. D. R.; Quarendon, P.

    1986-05-01

    A system for the production of a four dimensional (moving three dimensional) human epicardial left ventriculogram, modelled and highlighted to show regional wall motion changes, is described. The moving image is derived by fitting a surface to the three dimensional coordinates of coronary artery bifurcations. These are determined by analysis of digitised biplane coronary cineangiograms. This image system not only provides a unique 3-D view of left ventricular activity but might also provide measures of cardiac dynamics such as, stroke volume and velocity of wall movement. The system is not fully automated although operator interaction may be minimised. Further work on vessel tracking systems is required before full automation is possible.

  20. Coronary Artery PET/MR Imaging: Feasibility, Limitations, and Solutions.

    Science.gov (United States)

    Robson, Philip M; Dweck, Marc R; Trivieri, Maria Giovanna; Abgral, Ronan; Karakatsanis, Nicolas A; Contreras, Johanna; Gidwani, Umesh; Narula, Jagat P; Fuster, Valentin; Kovacic, Jason C; Fayad, Zahi A

    2017-10-01

    The aims of this study were to describe the authors' initial experience with combined coronary artery positron emission tomographic (PET) and magnetic resonance (MR) imaging using 18F-fluorodeoxyglucose (18F-FDG) and 18F-sodium fluoride (18F-NaF) radiotracers, describe common problems and their solutions, and demonstrate the feasibility of coronary PET/MR imaging in appropriate patients. Recently, PET imaging has been applied to the aortic valve and regions of atherosclerosis. 18F-FDG PET imaging has become established for imaging inflammation in atherosclerosis in the aorta and carotid arteries. Moreover, 18F-NaF has emerged as a novel tracer of active microcalcification in the aortic valve and coronary arteries. Coronary PET imaging remains challenging because of the small caliber of the vessels and their complex motion. Currently, most coronary imaging uses combined PET and computed tomographic imaging, but there is increasing enthusiasm for PET/MR imaging because of its reduced radiation, potential to correct for motion, and the complementary information available from cardiac MR in a single scan. Twenty-three patients with diagnosed or documented risk factors for coronary artery disease underwent either 18F-FDG or 18F-NaF PET/MR imaging. Standard breath-held MR-based attenuation correction was compared with a novel free-breathing approach. The impact on PET image artifacts and the interpretation of vascular uptake were evaluated semiquantitatively by expert readers. Moreover, PET reconstructions with more algorithm iterations were compared visually and by target-to-background ratio. Image quality was significantly improved by novel free-breathing attenuation correction. Moreover, conspicuity of coronary uptake was improved by increasing the number of algorithm iterations from 3 to 6. Elevated radiotracer uptake could be localized to individual coronary lesions using both 18F-FDG (n = 1, maximal target-to-background ratio = 1.61) and 18F-NaF (n = 7

  1. 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.

  2. Combined PET/MR imaging in neurology

    DEFF Research Database (Denmark)

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

    2014-01-01

    ). RESULTS: PET activity values in patients following MR-AC (A) showed a substantial radial dependency when compared to PET/CT. In all patients cortical PET activity was lower than the activity in the central region of the brain (10-15%). When adding bone attenuation values to standard MR-AC (B and C......) the radial gradient of PET activity values was removed. Further evaluation of PET/MR activity following MR-AC (A) relative to MR-AC (C) using the full CT for attenuation correction showed an underestimation of 25% in the cortical regions and 5-10% in the central regions of the brain. Observations in patients...... were replicated by observations from the phantom study. CONCLUSION: Our phantom and patient data demonstrate a spatially varying bias of the PET activity in PET/MR images of the brain when bone tissue is not accounted for during attenuation correction. This has immediate implications for PET/MR imaging...

  3. 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.)

  4. Accelerated acquisition of tagged MRI for cardiac motion correction in simultaneous PET-MR: Phantom and patient studies

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chuan, E-mail: chuan.huang@stonybrookmedicine.edu [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Departments of Radiology, Psychiatry, Stony Brook Medicine, Stony Brook, New York 11794 (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); Ouyang, Jinsong; El Fakhri, Georges [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); Reese, Timothy G. [Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 and Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129 (United States); Ahlman, Mark A.; Bluemke, David A. [Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, Maryland 20892 (United States)

    2015-02-15

    Purpose: Degradation of image quality caused by cardiac and respiratory motions hampers the diagnostic quality of cardiac PET. It has been shown that improved diagnostic accuracy of myocardial defect can be achieved by tagged MR (tMR) based PET motion correction using simultaneous PET-MR. However, one major hurdle for the adoption of tMR-based PET motion correction in the PET-MR routine is the long acquisition time needed for the collection of fully sampled tMR data. In this work, the authors propose an accelerated tMR acquisition strategy using parallel imaging and/or compressed sensing and assess the impact on the tMR-based motion corrected PET using phantom and patient data. Methods: Fully sampled tMR data were acquired simultaneously with PET list-mode data on two simultaneous PET-MR scanners for a cardiac phantom and a patient. Parallel imaging and compressed sensing were retrospectively performed by GRAPPA and kt-FOCUSS algorithms with various acceleration factors. Motion fields were estimated using nonrigid B-spline image registration from both the accelerated and fully sampled tMR images. The motion fields were incorporated into a motion corrected ordered subset expectation maximization reconstruction algorithm with motion-dependent attenuation correction. Results: Although tMR acceleration introduced image artifacts into the tMR images for both phantom and patient data, motion corrected PET images yielded similar image quality as those obtained using the fully sampled tMR images for low to moderate acceleration factors (<4). Quantitative analysis of myocardial defect contrast over ten independent noise realizations showed similar results. It was further observed that although the image quality of the motion corrected PET images deteriorates for high acceleration factors, the images were still superior to the images reconstructed without motion correction. Conclusions: Accelerated tMR images obtained with more than 4 times acceleration can still provide

  5. Ultra-low Dose CT for Attenuation Correction of 82Rb Cardiac PET

    DEFF Research Database (Denmark)

    Sørensen, Maria Balshøj; Bouchelouche, Kirsten; Tolbod, Lars Poulsen

    Aim: Myocardial perfusion imaging (MPI) using cardiac PET with tracers like 82Rb and 15O-water is substantially lower in radiation dose than classic MIBI-based SPECT. However, for cardiac PET, the dose contribution of CT for attenuation correction (CTAC) is typically 20-30% of the total dose....... To reduce the total radiation dose of cardiac PET further, we set out to examine if the use of ultra-low dose CTAC (UL-CTAC) would affect the accuracy of the quantitative parameters related to MPI. Furthermore, we examined whether the low quality of the UL-CTAC would affect the technologist’s ability...... to perform manual adjustment for misalignment between PET and CTAC. The CT reconstruction algorithm Q.AC was used to improve quality and consistency of the CTAC. Method: 23 consecutive clinical patients (BMI: 26.9 [range: 15.4-38.8]) referred for 82Rb PET rest and stress imaging were included in the study...

  6. Heterogeneous response of cardiac sympathetic function to cardiac resynchronization therapy in heart failure documented by 11[C]-hydroxy-ephedrine and PET/CT.

    Science.gov (United States)

    Capitanio, Selene; Nanni, Cristina; Marini, Cecilia; Bonfiglioli, Rachele; Martignani, Cristian; Dib, Bassam; Fuccio, Chiara; Boriani, Giuseppe; Picori, Lorena; Boschi, Stefano; Morbelli, Silvia; Fanti, Stefano; Sambuceti, Gianmario

    2015-11-01

    Cardiac resynchronization therapy (CRT) is an accepted treatment in patients with end-stage heart failure. PET permits the absolute quantification of global and regional homogeneity in cardiac sympathetic innervation. We evaluated the variation of cardiac adrenergic activity in patients with idiopathic heart failure (IHF) disease (NYHA III-IV) after CRT using (11)C-hydroxyephedrine (HED) PET/CT. Ten IHF patients (mean age = 68; range = 55-81; average left ventricular ejection fraction 26 ± 4%) implanted with a resynchronization device underwent three HED PET/CT studies: PET 1 one week after inactive device implantation; PET 2, one week after PET 1 under stimulated rhythm; PET 3, at 3 months under active CRT. A dedicated software (PMOD 3.4 version) was used to estimate global and regional cardiac uptake of HED through 17 segment polar maps. At baseline, HED uptake was heterogeneously distributed throughout the left ventricle with a variation coefficient of 18 ± 5%. This variable markedly decreased after three months CRT (12 ± 5%, p cardiac sympathetic system to CRT and a systemic response involving remote tissues with rich adrenergic innervation. This work might contribute to identify imaging parameters that could predict the response to CRT therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. 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.

  8. Kinetic modeling in PET imaging of hypoxia

    DEFF Research Database (Denmark)

    Joergensen, Jesper T; Hansen, Anders E; Kjaer, Andreas

    2014-01-01

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

  9. Kinetic modeling in PET imaging of hypoxia

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  10. Clinical PET/MR Imaging in Oncology

    DEFF Research Database (Denmark)

    Kjær, Andreas; Torigian, Drew A.

    2016-01-01

    . The question, therefore, arises regarding what the future clinical applications of PET/MR imaging will be. In this article, the authors discuss ways in which PET/MR imaging may be used in future applications that justify the added cost, predominantly focusing on oncologic applications. The authors suggest...

  11. Magnetic Resonance-based Motion Correction for Quantitative PET in Simultaneous PET-MR Imaging.

    Science.gov (United States)

    Rakvongthai, Yothin; El Fakhri, Georges

    2017-07-01

    Motion degrades image quality and quantitation of PET images, and is an obstacle to quantitative PET imaging. Simultaneous PET-MR offers a tool that can be used for correcting the motion in PET images by using anatomic information from MR imaging acquired concurrently. Motion correction can be performed by transforming a set of reconstructed PET images into the same frame or by incorporating the transformation into the system model and reconstructing the motion-corrected image. Several phantom and patient studies have validated that MR-based motion correction strategies have great promise for quantitative PET imaging in simultaneous PET-MR. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Significance of 18 F-FDG PET and immunohistochemical GLUT-1 expression for cardiac myxoma.

    Science.gov (United States)

    Okazaki, Yukio; Yamada, Sohsuke; Kitada, Shohei; Matsunaga, Iwao; Nogami, Eijirou; Watanabe, Teruo; Sasaguri, Yasuyuki; Honma, Yutaka; Itou, Tsuyoshi

    2014-06-16

    Cardiac tumours are relatively rare and are difficult to diagnose merely with imaging techniques. We demonstrated an unusual case of left atrial myxoma, displaying the successful detection by positron emission tomography using 2-deoxy-2-[18 F] fluoro-D-glucose (18 F-FDG PET), correlated closely to more intense and enhanced immunoreactivity with glucose transporter-1 (GLUT-1) in a substantial number of cardiac myxoma cells. Further prospective studies are needed to validate the significance of 18 F-FDG PET findings for cardiac myxoma and the association with immunohistochemical GLUT-1 expression in its tumour cells, after collecting and investigating a larger number of surgical cases examined with both of them. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2991481941253449.

  13. Is it time for cardiac innervation imaging?

    Energy Technology Data Exchange (ETDEWEB)

    Knuuti, J. [Turku Univ., Turku (Finland) Turku PET Center; Sipola, P. [Kuopio Univ., Kuopio (Finland)

    2005-03-01

    The autonomic nervous system plays an important role in the regulation of cardiac function and the regional distribution of cardiac nerve terminals can be visualized using scintigraphic techniques. The most commonly used tracer is iodine-123-metaiodobenzylguanidine (MIBG) but C-11-hydroxyephedrine has also been used with PET. When imaging with MIBG, the ratio of heart-to-mediastinal counts is used as an index of tracer uptake, and regional distribution is also assessed from tomographic images. The rate of clearance of the tracer can also be measured and indicates the function of the adrenergic system. Innervation imaging has been applied in patients with susceptibility to arrythmias, coronary artery disease, hypertrophic and dilated cardiomyopathy and anthracycline induced cardiotoxicity. Abnormal adrenergic innervation or function appear to exist in many pathophysiological conditions indicating that sympathetic neurons are very susceptible to damage. Abnormal findings in innervation imaging also appear to have significant prognostic value especially in patients with cardiomyopathy. Recently, it has also been shown that innervation imaging can monitor drug-induced changes in cardiac adrenergic activity. Although innervation imaging holds great promise for clinical use, the method has not received wider clinical acceptance. Larger randomized studies are required to confirm the value of innervation imaging in various specific indications.

  14. Assessment of attenuation correction for myocardial PET imaging using combined PET/MRI.

    Science.gov (United States)

    Lassen, Martin Lyngby; Rasul, Sazan; Beitzke, Dietrich; Stelzmüller, Marie-Elisabeth; Cal-Gonzalez, Jacobo; Hacker, Marcus; Beyer, Thomas

    2017-11-22

    To evaluate the frequency of artifacts in MR-based attenuation correction (AC) maps and their impact on the quantitative accuracy of PET-based flow and metabolism measurements in a cohort of consecutive heart failure patients undergoing combined PET/MR imaging. Myocardial viability studies were performed in 20 patients following a dual-tracer protocol involving the assessment of myocardial perfusion (13N-NH3: 813 ± 86 MBq) and metabolism (18F-FDG: 335 ± 38 MBq). All acquisitions were performed using a fully-integrated PET/MR system, with standard DIXON-attenuation correction (DIXON-AC) mapping for each PET scan. All AC maps were examined for spatial misalignment with the emission data, total lung volume, susceptibility artifacts, and tissue inversion (TI). Misalignment and susceptibility artifacts were corrected using rigid co-registration and retrospective filling of the susceptibility-induced gaps, respectively. The effects of the AC artifacts were evaluated by relative difference measures and perceived changes in clinical interpretations. Average respiratory misalignment of (7 ± 4) mm of the PET-emission data and the AC maps was observed in 18 (90%) patients. Substantial changes in the lung volumes of the AC maps were observed in the test-retest analysis (ratio: 1.0 ± 0.2, range: 0.8-1.4). Susceptibility artifacts were observed in 10 (50%) patients, while six (30%) patients had TI artifacts. Average differences of 14 ± 10% were observed for PET images reconstructed with the artifactual AC maps. The combined artifact effects caused false-positive findings in three (15%) patients. Standard DIXON-AC maps must be examined carefully for artifacts and misalignment effects prior to AC correction of cardiac PET/MRI studies in order to avoid misinterpretation of biased perfusion and metabolism readings from the PET data.

  15. PET tracer for imaging of neuroendocrine tumors

    DEFF Research Database (Denmark)

    2013-01-01

    There is provided a radiolabelled peptide-based compound for diagnostic imaging using positron emission tomography (PET). The compound may thus be used for diagnosis of malignant diseases. The compound is particularly useful for imaging of somatostatin overexpression in tumors, wherein the compound...... is capable of being imaged by PET when administered with a target dose in the range of 150-350 MBq, such as 150-250 MBq, preferable in the range of 191-210 MBq....

  16. Quantitative Techniques in PET-CT Imaging

    NARCIS (Netherlands)

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

    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

  17. Imaging neuronal pathways with 52Mn PET

    DEFF Research Database (Denmark)

    Napieczynska, Hanna; Severin, Gregory; Fonslet, Jesper

    2017-01-01

    tomography (PET) neuronal tract tracer. We used 52Mn for imaging dopaminergic pathways after a unilateral injection into the ventral tegmental area (VTA), as well as the striatonigral pathway after an injection into the dorsal striatum (STR) in rats. Furthermore, we tested potentially noxious effects...... of the radioactivity dose with a behavioral test and histological staining. 24 h after 52Mn administration, the neuronal tracts were clearly visible in PET images and statistical analysis confirmed the observed distribution of the tracer. We noticed a behavioral impairment in some animals treated with 170 kBq of 52Mn...... for PET imaging....

  18. Quantitative PET imaging with the 3T MR-BrainPET

    Energy Technology Data Exchange (ETDEWEB)

    Weirich, C., E-mail: c.weirich@fz-juelich.de [Forschungszentrum Jülich, Institute of Neuroscience and Medicine – 4, Juelich (Germany); Scheins, J.; Lohmann, P.; Tellmann, L. [Forschungszentrum Jülich, Institute of Neuroscience and Medicine – 4, Juelich (Germany); Byars, L.; Michel, C. [Siemens Healthcare, Molecular Imaging, Knoxville, TN (United States); Rota Kops, E.; Brenner, D.; Herzog, H.; Shah, N.J. [Forschungszentrum Jülich, Institute of Neuroscience and Medicine – 4, Juelich (Germany)

    2013-02-21

    The new hybrid imaging technology of MR-PET allows for simultaneous acquisition of versatile MRI contrasts and the quantitative metabolic imaging with PET. In order to achieve the quantification of PET images with minimal residual error the application of several corrections is crucial. In this work we present our results on quantification with the 3T MR BrainPET scanner.

  19. Cardiac magnetic resonance imaging

    African Journals Online (AJOL)

    2011-03-06

    right ventricular fibrosis); (d) idiopathic dilated cardiomyopathy. (midwall fibrosis); (e) infiltrative cardiomyopathies (cardiac sarcoidosis); and (f) systemic vasculitides (Churg Strauss Syndrome). LV = left ventricle;. RV = right ...

  20. PET/MR Imaging in Vascular Disease

    DEFF Research Database (Denmark)

    Ripa, Rasmus Sejersten; Pedersen, Sune Folke; Kjær, Andreas

    2016-01-01

    For imaging of atherosclerotic disease, lumenography using computed tomography, ultrasonography, or invasive angiography is still the backbone of evaluation. However, these methods are less effective to predict the likelihood of future thromboembolic events caused by vulnerability of plaques. PET...

  1. Simultaneous trimodal PET-MR-EEG imaging: Do EEG caps generate artefacts in PET images?

    OpenAIRE

    Ravichandran Rajkumar; Elena Rota Kops; Jörg Mauler; Lutz Tellmann; Christoph Lerche; Hans Herzog; N Jon Shah; Irene Neuner

    2017-01-01

    Trimodal simultaneous acquisition of positron emission tomography (PET), magnetic resonance imaging (MRI), and electroencephalography (EEG) has become feasible due to the development of hybrid PET-MR scanners. To capture the temporal dynamics of neuronal activation on a millisecond-by-millisecond basis, an EEG system is appended to the quantitative high resolution PET-MR imaging modality already established in our institute. One of the major difficulties associated with the development of sim...

  2. Imaging in cardiac mass lesions

    Energy Technology Data Exchange (ETDEWEB)

    Mundinger, A.; Gruber, H.P.; Dinkel, E.; Geibel, A.; Beck, A.; Wimmer, B.; Schlosser, V. (Freiburg Univ. (Germany))

    In 26 patients with cardiac mass lesions confirmed by surgery, diagnostic imaging was performed preoperatively by means of two-dimensional echocardiography (26 patients), angiography (12 patients), correlative computed tomography (CT, 8 patients), and magnetic resonance imaging (MRI, 3 patients). Two-dimensional echocardiography correctly identified the cardiac masses in all patients. Angiography missed two of 12 cardiac masses; CT missed one of eight. MRI identified three of three cardiac masses. Although the sensitivity of two-dimensional echocardiography was high (100%), all methods lacked specificity. None of the methods allowed differentiation between myxoma (n=13) and thrombus (n=7). Malignancy of the lesions was successfully predicted by noninvasive imaging methods in all six patients. However, CT and MRI provided additional information concerning cardiac mural infiltration, pericardial involvement, and extracardiac tumor extension, and should be integrated within a preoperative imaging strategy. Thus two-dimensional echocardiography is the method of choice for primary assessment of patients with suspected cardiac masses. Further preoperative imaging by CT or MRI can be limited to patients with malignancies suspected on the grounds of pericardial effusion or other clinical results. (author).

  3. Cardiac T1 Imaging

    OpenAIRE

    Jerosch-Herold, Michael; Kwong, Raymond Y.

    2014-01-01

    T1 mapping of the heart has evolved into a valuable tool to evaluate myocardial tissue properties, with or without contrast injection, including assessment of myocardial edema and free water content, extra-cellular volume (expansion), and most recently cardiomyocyte hypertrophy. The MRI pulse sequence techniques developed for these applications have had to address at least two important considerations for cardiac applications: measure magnetization inversion recoveries during cardiac motion w...

  4. Cardiac imaging in infectious endocarditis

    DEFF Research Database (Denmark)

    Bruun, Niels Eske; Habib, Gilbert; Thuny, Franck

    2014-01-01

    and abnormalities in the heart, but it does not uncover the underlying pathophysiological processes at the cellular or molecular level. This problem is addressed with introduction of new molecular imaging methods as (18)F-fluorodesoxyglucose ((18)F-FDG) PET-CT and single photon emission computed tomography fused...... infectious foci. A flowchart for the use of imaging in both left-sided and right-sided endocarditis is suggested....

  5. Cardiac displacement during13N-Ammonia myocardial perfusion PET/CT: comparison between adenosine and regadenoson induced stress.

    Science.gov (United States)

    Vleeming, Elise; Lazarenko, Sergiy; van der Zant, Friso; Pan, Xiao-Bo; Declerck, Jerome; Wondergem, Maurits; Knol, Remco

    2017-12-22

    In this study, differences are investigated in cardiac displacement during adenosine stress versus regadenoson stress in 13 N-Ammonia( 13 NH 3 ) MP PET/CT scans. A total of 61 MP PET/CTs were acquired using either adenosine (n=30) or regadenoson (n=31) as a stressor. For both groups, cardiac displacement during rest and stress was measured three-dimensionally, relative to either a fixed reference frame or the previous frame, in each 1-minute frame of a list-mode PET acquisition of 25 minutes. All stress scans were additionally evaluated for the presence of motion artifacts. Also, patient tolerability and occurrence of various side effects were compared between groups. Significantly larger cardiac displacement during stress was detected in the adenosine group as compared to the regadenoson group, reflected by both maximal cardiac displacement (p=0.022) and mean cardiac displacement (p=0.001). The duration of the movement was typically shorter in the regadenoson group. Frames with cardiac displacement ≥5 mm were observed nearly twice as frequent when using adenosine instead of regadenoson. The displacement during regadenoson stress is of lower amplitude and lasts shorter, and may therefore contribute to the lower incidence of motion artifacts on regadenoson compared to adenosine induced stress PET/CT scans. Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  6. Myocardial Fibrosis in Hypertrophic Cardiomyopathy Demonstrated by Integrated Cardiac F-18 FDG PET/MR

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Eunjung; Lee, Sanghee; Cho, Ihnho [Yeungnam Univ., Daegu (Korea, Republic of)

    2013-09-15

    Hypertrophic cardiomyopathy (HCM) is a common condition defined as a diffuse or segmental left ventricular (LV) hypertrophy with a nondilated and hyperdynamic chamber as well as cardiac arrhythmias. Cardiac MR (CMR) imaging is a key modality for evaluation of HCM. In addition to the assessment of LV wall thickness, LV function and aortic flow, CMR is capable of estimation of late gadolinium enhancement (LGE) in affected myocardium which has been shown to have a direct correlation with incidence and severity of arrhythmias in HCM. In patients with HCM, LGE on CMR is presumed to represent intramyocardial fibrosis. Meanwhile, F-18 FDG myocardial PET has been sporadically studied in HCM, mostly for evaluation of the metabolic status of a hypertrophic myocardial segment, especially after interventions or to demonstrate partial myocardial fibrosis. We presented here the case of a 25-year-old male patient referred for simultaneous F-18 FDG cardiac PET/MR for the evaluation of septal hypertrophy. The PET/MR revealed myocardial fibrosis in the septum associated with FDG-defect and LGE.

  7. Effect of motion-induced PET-CT misalignment on cardiac function and myocardial blood flow measured using dynamic 15O-water PET

    DEFF Research Database (Denmark)

    Lubberink, Mark; Ebrahimi, M; Harms, Hans

    amplitude, and is thus not affected by attenuation correction errors. Hence, misalignment is hypothesized not to affect 15O-water-based MBF to any large extent, but it may affect cardiac function measures derived from 15O-water scans. The aim of the present work was to assess the effect of PET......-induced stress on a Discovery MI PET-CT scanner. Attenuation correction was based on a respiration- averaged CT scan. Images were reconstructed using TF-OSEM including PSF-recovery. PET-CT misalignment was induced by translation of the PET relative to the CT (1 cm caudal or cranial, 1 cm cranial + ventral, and 2.......5 cm cranial + 1 cm ventral). MBF, MBFt, PTF, CO, SV and LVEF were calculated semi-automatically using aQuant software and values with and without misalignment were compared using correlation and Bland-Altman analysis. The original data, without misalignment, was analysed twice to assess intra...

  8. Assessment of Cardiac Sarcoidosis with Advanced Imaging Modalities

    Science.gov (United States)

    Akasaka, Takashi

    2014-01-01

    Sarcoidosis is a chronic systemic disease of unknown etiology that is characterized by the presence of noncaseating epithelioid granulomas, usually in multiple organs. Several studies have shown that sarcoidosis might be the result of an exaggerated granulomatous reaction after exposure to unidentified antigens in genetically susceptible individuals. Cardiac involvement may occur and lead to an adverse outcome: the heart mechanics will be affected and that causes ventricular failure, and the cardiac electrical system will be disrupted and lead to third degree atrioventricular block, malignant ventricular tachycardia, and sudden cardiac death. Thus, early diagnosis and treatment of this potentially devastating disease is critically important. However, sensitive and accurate imaging modalities have not been established. Recent studies have demonstrated the promising potential of cardiac magnetic resonance imaging (MRI) and 18F-fluoro-2-deoxyglucose positron emission tomography (18F-FDG PET) in the diagnosis and assessment of cardiac sarcoidosis (CS). In this review, we discuss the epidemiology, etiology, histological findings, and clinical features of sarcoidosis. We also introduce advanced imaging including 18F-FDG PET and cardiac MRI as more reliable diagnostic modalities for CS. PMID:25250336

  9. PET/MRI for Oncologic Brain Imaging

    DEFF Research Database (Denmark)

    Rausch, Ivo; Rischka, Lucas; Ladefoged, Claes N

    2017-01-01

    by Siemens Healthcare). As a reference, AC maps were derived from patient-specific CT images (CTref). PET data were reconstructed using standard settings after AC with all 4 AC methods. We report changes in diagnosis for all brain tumor patients and the following relative differences values (RDs...... of the whole brain and 10 anatomic regions segmented on MR images.Results:For brain tumor imaging (A and B), the standard PET-based diagnosis was not affected by any of the 3 MR-AC methods. For A, the average RDs of SUVmeanwere -10%, -4%, and -3% and of the VOIs 1%, 2%, and 7% for DIXON, UTE, and BD......, respectively.Conclusion:The diagnostic reading of PET/MR patients with brain tumors did not change with the chosen AC method. Quantitative accuracy of SUVs was clinically acceptable for UTE- and BD-AC for group A, whereas for group B BD was in accordance with CTref. Nevertheless, for the quantification...

  10. A dual tracer (68)Ga-DOTANOC PET/CT and (18)F-FDG PET/CT pilot study for detection of cardiac sarcoidosis.

    Science.gov (United States)

    Gormsen, Lars C; Haraldsen, Ate; Kramer, Stine; Dias, Andre H; Kim, Won Yong; Borghammer, Per

    2016-12-01

    Cardiac sarcoidosis (CS) is a potentially fatal condition lacking a single test with acceptable diagnostic accuracy. (18)F-FDG PET/CT has emerged as a promising imaging modality, but is challenged by physiological myocardial glucose uptake. An alternative tracer, (68)Ga-DOTANOC, binds to somatostatin receptors on inflammatory cells in sarcoid granulomas. We therefore aimed to conduct a proof-of-concept study using (68)Ga-DOTANOC to diagnose CS. In addition, we compared diagnostic accuracy and inter-observer variability of (68)Ga-DOTANOC vs. (18)F-FDG PET/CT. Nineteen patients (seven female) with suspected CS were prospectively recruited and dual tracer scanned within 7 days. PET images were reviewed by four expert readers for signs of CS and compared to the reference standard (Japanese ministry of Health and Welfare CS criteria). CS was diagnosed in 3/19 patients. By consensus, 11/19 (18)F-FDG scans and 0/19 (68)Ga-DOTANOC scans were rated as inconclusive. The sensitivity of (18)F-FDG PET for diagnosing CS was 33 %, specificity was 88 %, PPV was 33 %, NPV was 88 %, and diagnostic accuracy was 79 %. For (68)Ga-DOTANOC, accuracy was 100 %. Inter-observer agreement was poor for (18)F-FDG PET (Fleiss' combined kappa 0.27, NS) and significantly better for (68)Ga-DOTANOC (Fleiss' combined kappa 0.46, p = 0.001). Despite prolonged pre-scan fasting, a large proportion of (18)F-FDG PET/CT images were rated as inconclusive, resulting in low agreement among reviewers and correspondingly poor diagnostic accuracy. By contrast, (68)Ga-DOTANOC PET/CT had excellent diagnostic accuracy with the caveat that inter-observer variability was still significant. Nevertheless, (68)Ga-DOTANOC PET/CT looks very promising as an alternative CS PET tracer. Current Controlled Trials NCT01729169 .

  11. Do carotid MR surface coils affect PET quantification in PET/MR imaging?

    Energy Technology Data Exchange (ETDEWEB)

    Willemink, Martin J; Eldib, Mootaz [Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Leiner, Tim [Department of Radiology, University Medical Center Utrecht, Utrecht (Netherlands); Fayad, Zahi A; Mani, Venkatesh [Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY (United States)

    2015-05-18

    To evaluate the effect of surface coils for carotid MR imaging on PET quantification in a clinical simultaneous whole-body PET/MR scanner. A cylindrical phantom was filled with a homogeneous 2L water-FDG mixture at a starting dose of 301.2MBq. Clinical PET/MR and PET/CT systems were used to acquire PET-data without a coil (reference standard) and with two carotid MRI coils (Siemens Special Purpose 8-Channel and Machnet 4-Channel Phased Array). PET-signal attenuation was evaluated with Osirix using 51 (PET/MR) and 37 (PET/CT) circular ROIs. Mean and maximum standardized uptake values (SUVs) were quantified for each ROI. Furthermore, SUVs of PET/MR and PET/CT were compared. For validation, a patient was scanned with an injected dose of 407.7MBq on both a PET/CT and a PET/MR system without a coil and with both coils. PET/MR underestimations were -2.2% (Siemens) and -7.8% (Machnet) for SUVmean, and -1.2% (Siemens) and -3.3% (Machnet) for SUVmax, respectively. For PET/CT, underestimations were -1.3% (Siemens) and -1.4% (Machnet) for SUVmean and -0.5% (both Siemens and Machnet) for SUVmax, respectively using no coil data as reference. Except for PET/CT SUVmax values all differences were significant. SUVs differed significantly between PET/MR and PET/CT with SUVmean values of 0.51-0.55 for PET/MR and 0.68-0.69 for PET/CT, respectively. The patient examination showed that median SUVmean values measured in the carotid arteries decreased from 0.97 without a coil to 0.96 (Siemens) and 0.88 (Machnet). Carotid surface coils do affect attenuation correction in both PET/MR and PET/CT imaging. Furthermore, SUVs differed significantly between PET/MR and PET/CT.

  12. Cardiac imaging in infectious endocarditis.

    Science.gov (United States)

    Bruun, Niels Eske; Habib, Gilbert; Thuny, Franck; Sogaard, Peter

    2014-03-01

    Infectious endocarditis remains both a diagnostic and a treatment challenge. A positive outcome depends on a rapid diagnosis, accurate risk stratification, and a thorough follow-up. Imaging plays a key role in each of these steps and echocardiography remains the cornerstone of the methods in use. The technique of both transthoracic echocardiography and transoesophageal echocardiography has been markedly improved across the last decades and most recently three-dimensional real-time echocardiography has been introduced in the management of endocarditis patients. Echocardiography depicts structural changes and abnormalities in the heart, but it does not uncover the underlying pathophysiological processes at the cellular or molecular level. This problem is addressed with introduction of new molecular imaging methods as (18)F-fluorodesoxyglucose ((18)F-FDG) PET-CT and single photon emission computed tomography fused with conventional CT (SPECT/CT). Of these methods, (18)F-FDG PET-CT carries the best promise for a future role in endocarditis. But there are distinct limitations with both SPECT/CT and (18)F-FDG PET-CT which should not be neglected. MRI and spiral CT are methods primarily used in the search for extra cardial infectious foci. A flowchart for the use of imaging in both left-sided and right-sided endocarditis is suggested.

  13. Hybrid Magnetic Resonance Imaging and Positron Emission Tomography With Fluorodeoxyglucose to Diagnose Active Cardiac Sarcoidosis.

    Science.gov (United States)

    Dweck, Marc R; Abgral, Ronan; Trivieri, Maria Giovanna; Robson, Philip M; Karakatsanis, Nicolas; Mani, Venkatesh; Palmisano, Anna; Miller, Marc A; Lala, Anuradha; Chang, Helena L; Sanz, Javier; Contreras, Johanna; Narula, Jagat; Fuster, Valentin; Padilla, Maria; Fayad, Zahi A; Kovacic, Jason C

    2017-06-09

    The purpose of this study was to explore the diagnostic usefulness of hybrid cardiac magnetic resonance (CMR) and positron emission tomography (PET) using 18F-fluorodeoxyglucose (FDG) for active cardiac sarcoidosis. Active cardiac sarcoidosis (aCS) is underdiagnosed and has a high mortality. Patients with clinical suspicion of aCS underwent hybrid CMR/PET with late gadolinium enhancement (LGE) and FDG to assess the pattern of injury and disease activity, respectively. Patients were categorized visually as magnetic resonance (MR)+PET+ (characteristic LGE aligning exactly with increased FDG uptake), MR+PET- (characteristic LGE but no increased FDG), MR-PET- (neither characteristic LGE nor increased FDG), and MR-PET+ (increased FDG uptake in absence of characteristic LGE) and further characterized as aCS+ (MR+PET+) or aCS- (MR+PET-, MR-PET-, MR-PET+). FDG uptake was quantified using maximum target-to-normal-myocardium ratio and the net uptake rate (Ki) from dynamic Patlak analysis. Receiver operating characteristic methods were used to identify imaging biomarkers for aCS. FDG PET was assessed using computed tomography/PET in 19 control subjects with healthy myocardium. A total of 25 patients (12 males; 54.9 ± 9.8 years of age) were recruited prospectively; 8 were MR+PET+, suggestive of aCS; 1 was MR+PET-, consistent with inactive cardiac sarcoidosis; and 8 were MR-PET-, with no imaging evidence of cardiac sarcoidosis. Eight patients were MR-PET+ (6 with global myocardial FDG uptake, 2 with focal-on-diffuse uptake); they demonstrated distinct Ki values and hyperintense maximum standardized uptake value compared with MR+PET+ patients. Similar hyperintense patterns of global (n = 9) and focal-on-diffuse (n = 2) FDG uptake were also observed in control patients, suggesting physiological myocardial uptake. Maximum target-to-normal-myocardium ratio values were higher in the aCS+ group (p < 0.001), demonstrating an area under the curve of 0.98 on receiver operating

  14. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. (18)F-Fluorodeoxyglucose PET/MR Imaging in Lymphoma.

    Science.gov (United States)

    Platzek, Ivan

    2016-10-01

    (18)F-Fluorodeoxyglucose (FDG) PET/MR imaging is feasible for initial staging and therapy response assessment in lymphoma. Although FDG PET/MR imaging is equivalent to FDG PET/CT for initial staging of lymphoma, not enough data are available with regard to other indications yet. Diffusion-weighted MR imaging is a promising addition to FDG PET/MR imaging, but has not been evaluated systematically. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2018-02-01

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

  17. (Non-invasive evaluation of the cardiac autonomic nervous system by PET)

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The proposed research addresses the development, validation and application of cardiac PET imaging techniques to characterize the autonomic nervous system of the heart. PET technology has significantly matured over the last two decades. Instrument design, image processing and production of radiochemical compounds have formed an integrative approach to provide a powerful and novel imaging modality for the quantitative in vivo evaluation of the autonomic nervous system of the heart. Animal studies using novel tracers for the sympathetic and parasympathetic nerve terminals will be employed to characterize the functional integrity of nerve terminals. This work will be complemented by the development of agents which bind to postsynaptic receptor sites. The combined evaluation of presynaptic and postsynaptic neuronal function will allow a unique characterization of neuronal function. Initial development in animal studies will be followed by feasibility studies in humans. These studies are designed to test sophisticated imaging protocols in the human heart and validate the scintigraphic findings with independent markers of autonomic innervation. Subsequent clinical application in various cardiac diseases is expected to provide new insights into the neuropathophysiology of the heart.

  18. 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.)

  19. PET/MR Imaging in Musculoskeletal Disorders

    DEFF Research Database (Denmark)

    Andersen, Kim Francis; Jensen, Karl Erik; Loft, Annika

    2016-01-01

    , treatment planning and monitoring, and follow-up of patients with musculoskeletal malignancies, and may also prove helpful in assessment of musculoskeletal infectious and inflammatory disorders. The application of more sophisticated MR imaging sequences and PET radiotracers other than FDG in the diagnostic...... workup and follow-up of patients with musculoskeletal disorders should be explored....

  20. Calculation of left ventricular volumes and ejection fraction from dynamic cardiac-gated 15O-water PET/CT: 5D-PET

    Directory of Open Access Journals (Sweden)

    Jonny Nordström

    2017-11-01

    Full Text Available Abstract Background Quantitative measurement of myocardial blood flow (MBF is of increasing interest in the clinical assessment of patients with suspected coronary artery disease (CAD. 15O-water positron emission tomography (PET is considered the gold standard for non-invasive MBF measurements. However, calculation of left ventricular (LV volumes and ejection fraction (EF is not possible from standard 15O-water uptake images. The purpose of the present work was to investigate the possibility of calculating LV volumes and LVEF from cardiac-gated parametric blood volume (V B 15O-water images and from first pass (FP images. Sixteen patients with mitral or aortic regurgitation underwent an eight-gate dynamic cardiac-gated 15O-water PET/CT scan and cardiac MRI. V B and FP images were generated for each gate. Calculations of end-systolic volume (ESV, end-diastolic volume (EDV, stroke volume (SV and LVEF were performed with automatic segmentation of V B and FP images, using commercially available software. LV volumes and LVEF were calculated with surface-, count-, and volume-based methods, and the results were compared with gold standard MRI. Results Using V B images, high correlations between PET and MRI ESV (r = 0.89, p  0.86, p < 0.001. Conclusion Calculation of LV volumes and LVEF from dynamic 15O-water PET is feasible and shows good correlation with MRI. However, the analysis method is laborious, and future work is needed for more automation to make the method more easily applicable in a clinical setting.

  1. 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...

  2. PET imaging of the autonomic nervous system.

    Science.gov (United States)

    Thackeray, James T; Bengel, Frank M

    2016-12-01

    The autonomic nervous system is the primary extrinsic control of heart rate and contractility, and is subject to adaptive and maladaptive changes in cardiovascular disease. Consequently, noninvasive assessment of neuronal activity and function is an attractive target for molecular imaging. A myriad of targeted radiotracers have been developed over the last 25 years for imaging various components of the sympathetic and parasympathetic signal cascades. While routine clinical use remains somewhat limited, a number of larger scale studies in recent years have supplied momentum to molecular imaging of autonomic signaling. Specifically, the findings of the ADMIRE HF trial directly led to United States Food and Drug Administration approval of 123I-metaiodobenzylguanidine (MIBG) for Single Photon Emission Computed Tomography (SPECT) assessment of sympathetic neuronal innervation, and comparable results have been reported using the analogous PET agent 11C-meta-hydroxyephedrine (HED). Due to the inherent capacity for dynamic quantification and higher spatial resolution, regional analysis may be better served by PET. In addition, preliminary clinical and extensive preclinical experience has provided a broad foundation of cardiovascular applications for PET imaging of the autonomic nervous system. Recent years have witnessed the growth of novel quantification techniques, expansion of multiple tracer studies, and improved understanding of the uptake of different radiotracers, such that the transitional biology of dysfunctional subcellular catecholamine handling can be distinguished from complete denervation. As a result, sympathetic neuronal molecular imaging is poised to play a role in individualized patient care, by stratifying cardiovascular risk, visualizing underlying biology, and guiding and monitoring therapy.

  3. Simultaneous PET/MR imaging with a radio frequency-penetrable PET insert.

    Science.gov (United States)

    Grant, Alexander M; Lee, Brian J; Chang, Chen-Ming; Levin, Craig S

    2017-01-01

    A brain sized radio frequency (RF)-penetrable PET insert has been designed for simultaneous operation with MRI systems. This system takes advantage of electro-optical coupling and battery power to electrically float the PET insert relative to the MRI ground, permitting RF signals to be transmitted through small gaps between the modules that form the PET ring. This design facilitates the use of the built-in body coil for RF transmission and thus could be inserted into any existing MR site wishing to achieve simultaneous PET/MR imaging. The PET detectors employ nonmagnetic silicon photomultipliers in conjunction with a compressed sensing signal multiplexing scheme, and optical fibers to transmit analog PET detector signals out of the MRI room for decoding, processing, and image reconstruction. The PET insert was first constructed and tested in a laboratory benchtop setting, where tomographic images of a custom resolution phantom were successfully acquired. The PET insert was then placed within a 3T body MRI system, and tomographic resolution/contrast phantom images were acquired both with only the B0 field present, and under continuous pulsing from different MR imaging sequences. The resulting PET images have comparable contrast-to-noise ratios (CNR) under all MR pulsing conditions: The maximum percent CNR relative difference for each rod type among all four PET images acquired in the MRI system has a mean of 14.0 ± 7.7%. MR images were successfully acquired through the RF-penetrable PET shielding using only the built-in MR body coil, suggesting that simultaneous imaging is possible without significant mutual interference. These results show promise for this technology as an alternative to costly integrated PET/MR scanners; a PET insert that is compatible with any existing clinical MRI system could greatly increase the availability, accessibility, and dissemination of PET/MR. © 2016 American Association of Physicists in Medicine.

  4. FDG PET-CT findings of extra-thoracic sarcoid are associated with cardiac sarcoid: A rationale for using FGD PET-CT for cardiac sarcoid evaluation.

    Science.gov (United States)

    Patel, Darshan C; Gunasekaran, Senthil S; Goettl, Christopher; Sweiss, Nadera J; Lu, Yang

    2017-07-05

    This retrospective study investigates the relationship between cardiac and extra-thoracic sarcoid findings on FDG PET-CT using a 72-hour pretest high-fat, high-protein, and very low-carbohydrate (HFHPVLC) diet. A total of 196 consecutive FDG PET-CT scans with 72-hour HFHPVLC diet preparation were performed between December 2014 and December 2015 in known sarcoid patients. Of these scans, 5 were excluded for non-adherence to diet preparation or underlying cancer. Cardiac and extra-thoracic sarcoid lesions were categorized and measured for radiotracer uptake. A total of 188 patients had 191 eligible FDG PET/CT scans (3 follow-up scans), of which there were 20 (10%) positive, 6 indeterminate (3%), and 165 (86%) negative for CS. Among the 20 scans positive for CS, 8 (40%) had findings of both cardiac and extra-thoracic sarcoid. Our study shows that 40% of CS patients also have FDG PET-CT findings of extra-thoracic sarcoid. This makes an intriguing case for FDG PET-CT use with pretest diet prep over cardiac MRI (CMR) for cardiac sarcoid evaluation, given that CMR is likely to overlook these extra-thoracic sites of disease.

  5. 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

  6. The need for standardisation of cardiac FDG PET imaging in the evaluation of myocardial viability in patients with chronic ischaemic left ventricular dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Kuuti, J. [Turku Univ. (Finland). Turku PET Centre; Schelbert, H.R. [UCLA School of Medicine, Los Angeles, CA (United States). Dept. of Molecular and Medical Pharmacology; Bax, J.J. [Leiden University Medical Center (Netherlands). Dept. of Cardilogy

    2002-09-01

    The evaluation of myocardial glucose utilisation with fluorine-18 fluorodeoxyglucose (FDG) and positron emission tomography is currently considered the most reliable tool for the identification of myocardial viability. However, the investigations using FDG imaging to predict improvement in left ventricular (LV) function after revascularisation have reported wide ranges for sensitivity (71%-100%) and, in particular, for specificity (33%-91%). The variable results may be related to differences in study populations but also to differences in the imaging protocols employed. Detailed analysis of the published studies has revealed differences in study populations, patient selection criteria, the methods for assessing changes in LV function post revascularisation and the timing of these assessments. Even more importantly, protocols have varied substantially with regard to imaging equipment, perfusion tracers, metabolic conditions, data analysis and interpretation of results. In addition, evaluation of patients with insulin resistance appears to represent a specific challenge. This review examines the different study protocols and methodologies used for myocardial FDG imaging in order to draw conclusions concerning optimal imaging protocols. It appears that the optimisation and standardisation of study protocols and analysis of FDG images for the assessment of myocardial viability are critical. In addition, multi-centre trials seem warranted on prediction of long-term function, congestive heart failure symptoms, survival and quality of life.

  7. Fat-constrained 18F-FDG PET reconstruction in hybrid PET/MR imaging.

    Science.gov (United States)

    Prevrhal, Sven; Heinzer, Susanne; Wülker, Christian; Renisch, Steffen; Ratib, Osman; Börnert, Peter

    2014-10-01

    Fusion of information from PET and MR imaging can increase the diagnostic value of both modalities. This work sought to improve (18)F FDG PET image quality by using MR Dixon fat-constrained images to constrain PET image reconstruction to low-fat regions, with the working hypothesis that fatty tissue metabolism is low in glucose consumption. A novel constrained PET reconstruction algorithm was implemented via a modification of the system matrix in list-mode time-of-flight ordered-subsets expectation maximization reconstruction, similar to the way time-of-flight weighting is incorporated. To demonstrate its use in PET/MR imaging, we modeled a constraint based on fat/water-separating Dixon MR images that shift activity away from regions of fat tissue during PET image reconstruction. PET and MR imaging scans of a modified National Electrical Manufacturers Association/International Electrotechnical Commission body phantom simulating body fat/water composition and in vivo experiments on 2 oncology patients were performed on a commercial time-of-flight PET/MR imaging system. Fat-constrained PET reconstruction visibly and quantitatively increased resolution and contrast between high-uptake and fatty-tissue regions without significantly affecting the images in nonfat regions. The incorporation of MR tissue information, such as fat, in image reconstruction can improve the quality of PET images. The combination of a variety of potential other MR tissue characteristics with PET represents a further justification for merging MR data with PET data in hybrid systems. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  8. Preclinical molecular imaging using PET and MRI.

    Science.gov (United States)

    Wolf, Gunter; Abolmaali, Nasreddin

    2013-01-01

    Molecular imaging fundamentally changes the way we look at cancer. Imaging paradigms are now shifting away from classical morphological measures towards the assessment of functional, metabolic, cellular, and molecular information in vivo. Interdisciplinary driven developments of imaging methodology and probe molecules utilizing animal models of human cancers have enhanced our ability to non-invasively characterize neoplastic tissue and follow anti-cancer treatments. Preclinical molecular imaging offers a whole palette of excellent methodology to choose from. We will focus on positron emission tomography (PET) and magnetic resonance imaging (MRI) techniques, since they provide excellent and complementary molecular imaging capabilities and bear high potential for clinical translation. Prerequisites and consequences of using animal models as surrogates of human cancers in preclinical molecular imaging are outlined. We present physical principles, values and limitations of PET and MRI as molecular imaging modalities and comment on their high potential to non-invasively assess information on hypoxia, angiogenesis, apoptosis, gene expression, metabolism, and cell trafficking in preclinical cancer research.

  9. MRI-assisted dual motion correction for myocardial perfusion defect detection in PET imaging.

    Science.gov (United States)

    Wang, Xinhui; Rahmim, Arman; Tang, Jing

    2017-09-01

    Myocardial perfusion (MP) PET imaging is a powerful tool in risk assessment and stratification of patients with coronary artery disease. Involuntary organ motion degrades cardiac PET image resolution, while respiratory and/or cardiac gating to freeze the motion leads to noisier reconstructed images due to reduced counts in the gated frames. In this work, we propose an MRI-assisted dual motion correction method to compensate for respiratory and cardiac motion in MP PET data and study the impact of dual motion correction on MP defect detection using systematically designed experiments. The proposed dual motion correction method addresses the respiratory motion before correcting the cardiac motion among the respiratory motion corrected cardiac gates. The respiratory motion is estimated from the respiratory-gated only PET images and compensated within a 4D motion-incorporated image reconstruction algorithm. The cardiac motion is then corrected using the motion vector fields estimated from the corresponding cardiac-gated MR images. To evaluate the proposed method, we performed experiments using the standard XCAT phantom and two individual-specific volunteer XCAT phantoms. For each of the three phantoms, we simulated four dual-gated Rb-82 MP PET imaging datasets, one with normal perfusion and the other three with 50% nontransmural, 75% nontransmural, and transmural regionally reduced perfusion. The corresponding cardiac-gated MR images were simulated by the SIMRI simulator, with the sequence specified to be 3D T1-weighted as used in a protocol of a clinical PET/MRI scanner. We quantitatively evaluated the reconstructed images with no motion correction, only respiratory motion correction and dual motion correction, in terms of the myocardium to blood pool contrast and the trade-off between the noise and the normal to defect contrast. Using the channelized Hotelling observer, we performed receiver operating characteristic analysis for the task of detecting perfusion

  10. SPECT and PET Imaging of Meningiomas

    Directory of Open Access Journals (Sweden)

    Varvara Valotassiou

    2012-01-01

    Full Text Available Meningiomas arise from the meningothelial cells of the arachnoid membranes. They are the most common primary intracranial neoplasms and represent about 20% of all intracranial tumors. They are usually diagnosed after the third decade of life and they are more frequent in women than in men. According to the World Health Organization (WHO criteria, meningiomas can be classified into grade I meningiomas, which are benign, grade II (atypical and grade III (anaplastic meningiomas, which have a much more aggressive clinical behaviour. Computed Tomography (CT and Magnetic Resonance Imaging (MRI are routinely used in the diagnostic workup of patients with meningiomas. Molecular Nuclear Medicine Imaging with Single Photon Emission Computed Tomography (SPECT and Positron Emission Tomography (PET could provide complementary information to CT and MRI. Various SPECT and PET tracers may provide information about cellular processes and biological characteristics of meningiomas. Therefore, SPECT and PET imaging could be used for the preoperative noninvasive diagnosis and differential diagnosis of meningiomas, prediction of tumor grade and tumor recurrence, response to treatment, target volume delineation for radiation therapy planning, and distinction between residual or recurrent tumour from scar tissue.

  11. Automatic extraction of myocardial mass and volumes using parametric images from dynamic nongated PET

    DEFF Research Database (Denmark)

    Harms, Hendrik Johannes; Hansson, Nils Henrik Stubkjær; Tolbod, Lars Poulsen

    2016-01-01

    Dynamic cardiac positron emission tomography (PET) is used to quantify molecular processes in vivo. However, measurements of left-ventricular (LV) mass and volumes require electrocardiogram (ECG)-gated PET data. The aim of this study was to explore the feasibility of measuring LV geometry using non......-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......) and LV ejection fraction (LVEF). PET measurements were compared with CMR. RESULTS: High and linear correlations were found for LV mass (r=0.95), ESV (r=0.93) and EDV (r=0.90), and slightly lower for SV (r=0.74), LVEF (r=0.81) and WT(r=0.78). Bland Altman analyses showed significant differences for m...

  12. Development of PET insert for simultaneous PET/MR imaging of human brain

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jiwoong; Choi, Yong; Jung, Jin Ho; Kim, Sangsu; Im, Ki Chun; Lim, Hyun Keong [Molecular Imaging Research & Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Oh, Changheun; Park, HyunWook; Cho, Gyuseong [Departments of Electrical Engineering and Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon (Korea, Republic of)

    2014-07-29

    Recently, there has been great interest on the development of combined PET/MR, which is a useful tool for both functional and anatomic imaging. The purpose of this study was to develop a MR compatible PET insert for simultaneous PET and MR imaging of human brain and to evaluate the performance of the hybrid PET-MRI. The PET insert consisted of 18 detector blocks arranged in a ring of 390 mm diameter with 60 mm axial FOV. Each detector block was composed of 4 × 4 matrix of detector modules, each of which consisted of a 4 × 4 array LYSO coupled to a 4 × 4 GAPD array. The PET gantry was shielded with gold-plated conductive fabric tapes. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuits (PDCs) and then transferred to FPGA-embedded DAQ modules. The PDCs and DAQ modules were enclosed in an aluminum box and located at the rear of the MR bore inside MRI room. 3-T human MRIs of two different vendors were used to evaluate the MR compatibility of developed PET insert. No significant changes of the PET performance and the homogeneity of MR images caused by the non-compatibility of PET-MRI were observed with the 2 different MRIs. The signal intensities of MR images were slightly degraded (<3.6%) with the both MRI systems. The difference between independently and simultaneously acquired PET images of brain phantom was negligibly small (<4.3%). High quality simultaneous brain PET and MRI of 3 normal volunteers were successfully acquired. Experimental results indicate that the high performance compact and lightweight PET insert for hybrid PET/MRI, which could be utilized with the MRI from various manufactures, can be developed using GAPD arrays and charge signal transmission method proposed in this study.

  13. Brain {sup 18}F-FDG, {sup 18}F-florbtaben PET/CT, {sup 123}I-FP-CIT SPECT and cardiac {sup 123}I-MBG imaging for diagnosis of a 'cerebral type' of Lewy Body disease

    Energy Technology Data Exchange (ETDEWEB)

    Gucht, Axel Van Der; Bélissant, Ophélie; Rabu, Corenti; Cottereau, Anne-Ségolène; Evangelista, Eva; Chalaye, Julia; Bonnot-Lours, Sophie; Fénelon, Gilles; Itti, Emmanuel [Dept. of Nuclear Medicine, AP-HP, Henri-Mondor Teaching Hospital, Crteil (France); De Langavant, Laurent Cleret [Cognitive Neurology Unit, H. Mondor Hospital, Creteil (France)

    2016-09-15

    A 67-year-old man was referred for fluctuating neuropsychiatric symptoms, featuring depression, delirious episodes, recurrent visual hallucinations and catatonic syndrome associated with cognitive decline. No parkinsonism was found clinically even under neuroleptic treatment. {sup 18}F-FDG PET/CT showed hypometabolism in the posterior associative cortex including the occipital cortex, suggesting Lewy body dementia, but {sup 123}I-FP-CIT SPECT was normal and cardiac {sup 123}I-MIBG imaging showed no signs of sympathetic denervation. Alzheimer's disease was excluded by a normal {sup 18}F-florbetaben PET/CT. This report suggests a rare case of α-synucleinopathy without brainstem involvement, referred to as 'cerebral type' of Lewy body disease.

  14. 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.

  15. 11C-meta-hydroxyephedrine: a promising PET radiopharmaceutical for imaging the sympathetic nervous system.

    Science.gov (United States)

    Boschi, Stefano; Lodi, Filippo; Boschi, Laura; Nanni, Cristina; Chondrogiannis, Sotirios; Colletti, Patrick M; Rubello, Domenico; Fanti, Stefano

    2015-02-01

    Dysfunction of the sympathetic nervous system underlies many cardiac diseases and can be assessed by molecular imaging using SPECT tracers as I-metaiodobenzylguanidine (I-MIBG). The norepinephrine analog C-meta-hydroxyephedrine (HED) has been used with PET to map the regional distribution of cardiac sympathetic neurons. Hydroxyephedrine is rapidly transported into sympathetic neurons by the norepinephrine transporter and stored in vesicles. This review describes the mechanism of action, radiosynthesis, and application of HED in the assessment of the cardiac sympathetic nervous system in heart failure, myocardial infarction, and arrhythmias. Noncardiac applications of HED in the clinical setting of sympathetic nervous system tumors and other emerging research applications are described.

  16. [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 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...

  17. [Evaluation of new technologies PET/CT nuclear imaging].

    Science.gov (United States)

    Giraldes, Maria Rosário

    2010-01-01

    Nuclear imaging has used initially anatomic and volumetric technologies as CT or MRI. In recent years new dimensions of non invasive studies, as PET, have shown a higher utility in the effectiveness of the treatment. The evaluation of need must be done according to a principle of Horizontal Equity, equal treatment for equal need and of a principle of Vertical Equity, Different treatment, at regional level, according to each hospital level. The evaluation of need has been made according to the Potential Demand by Potential User Groups: diabetes, type 2, (50 years and more); screening colorectal (50 years and more); morbidity by cancer; surgery of lung cancer; cardiology; heart surgery; acute chest pain in the emergency department. In a Macro Perspective need has been evaluated using the Population Estimations for 2007, at municipality level. Relatively to Lisbon and Porto data at locality level has been used, from the 2001 Census. According to Campos, J.R. (2007), in 2006, it existed 1 PET by 1 million inhabitants and after that date 2 more were created (Quadrantes and Hospital ad Luz), belonging to the private sector. Mores 15 PET are needed in the NHS, 1 PET for about 504128 inhabitants. According to The Potential Demand perspective 18 new PET are needed, 15 from the public sector. The private sector will cover progressively the demand. Dorado and Albertino (2002), in Spain, mention that the introduction of this new technique in our Health System must be done slowly due to the cost and complexity. In Portugal exists already 6 PET and this applies also. As a first priority the intervention in Oncology in the IPO (Coimbra). A priority must be given to the University Hospitals of Santa Maria and São João. The Central Hospitals of Viseu and VilaReal/Régua must have also 1 PET. A priority must be given to the interior in order to avoid transports of patients and families. In fourth place the HC Central Lisbon must have also 1 PET, which will go to the New Hospital

  18. Quantitative, Simultaneous PET/MRI for Intratumoral Imaging with an MRI-Compatible PET Scanner

    Science.gov (United States)

    Ng, Thomas S.C.; Bading, James R.; Park, Ryan; Sohi, Hargun; Procissi, Daniel; Colcher, David; Conti, Peter S.; Cherry, Simon R.; Raubitschek, Andrew A.; Jacobs, Russell E.

    2012-01-01

    Noninvasive methods are needed to explore the heterogeneous tumor microenvironment and its modulation by therapy. Hybrid PET/MRI systems are being developed for small-animal and clinical use. The advantage of these integrated systems depends on their ability to provide MR images that are spatially coincident with simultaneously acquired PET images, allowing combined functional MRI and PET studies of intratissue heterogeneity. Although much effort has been devoted to developing this new technology, the issue of quantitative and spatial fidelity of PET images from hybrid PET/MRI systems to the tissues imaged has received little attention. Here, we evaluated the ability of a first-generation, small-animal MRI-compatible PET scanner to accurately depict heterogeneous patterns of radiotracer uptake in tumors. Methods Quantitative imaging characteristics of the MRI-compatible PET (PET/MRI) scanner were evaluated with phantoms using calibration coefficients derived from a mouse-sized linearity phantom. PET performance was compared with a commercial small-animal PET system and autoradiography in tumor-bearing mice. Pixel and structure-based similarity metrics were used to evaluate image concordance among modalities. Feasibility of simultaneous PET/MRI functional imaging of tumors was explored by following 64Cu-labeled antibody uptake in relation to diffusion MRI using cooccurrence matrix analysis. Results The PET/MRI scanner showed stable and linear response. Activity concentration recovery values (measured and true activity concentration) calculated for 4-mm-diameter rods within linearity and uniform activity rod phantoms were near unity (0.97 ± 0.06 and 1.03 ± 0.03, respectively). Intratumoral uptake patterns for both 18F-FDG and a 64Cu-antibody acquired using the PET/MRI scanner and small-animal PET were highly correlated with autoradiography (r > 0.99) and with each other (r = 0.97 ± 0.01). On the basis of these data, we performed a preliminary study comparing

  19. A knowledge-based method for reducing attenuation artefacts caused by cardiac appliances in myocardial PET/CT

    Science.gov (United States)

    Hamill, James J.; Brunken, Richard C.; Bybel, Bohdan; Di Filippo, Frank P.; Faul, David D.

    2006-06-01

    Attenuation artefacts due to implanted cardiac defibrillator leads have previously been shown to adversely impact cardiac PET/CT imaging. In this study, the severity of the problem is characterized, and an image-based method is described which reduces the resulting artefact in PET. Automatic implantable cardioverter defibrillator (AICD) leads cause a moving-metal artefact in the CT sections from which the PET attenuation correction factors (ACFs) are derived. Fluoroscopic cine images were measured to demonstrate that the defibrillator's highly attenuating distal shocking coil moves rhythmically across distances on the order of 1 cm. Rhythmic motion of this magnitude was created in a phantom with a moving defibrillator lead. A CT study of the phantom showed that the artefact contained regions of incorrect, very high CT values and adjacent regions of incorrect, very low CT values. The study also showed that motion made the artefact more severe. A knowledge-based metal artefact reduction method (MAR) is described that reduces the magnitude of the error in the CT images, without use of the corrupted sinograms. The method modifies the corrupted image through a sequence of artefact detection procedures, morphological operations, adjustments of CT values and three-dimensional filtering. The method treats bone the same as metal. The artefact reduction method is shown to run in a few seconds, and is validated by applying it to a series of phantom studies in which reconstructed PET tracer distribution values are wrong by as much as 60% in regions near the CT artefact when MAR is not applied, but the errors are reduced to about 10% of expected values when MAR is applied. MAR changes PET image values by a few per cent in regions not close to the artefact. The changes can be larger in the vicinity of bone. In patient studies, the PET reconstruction without MAR sometimes results in anomalously high values in the infero-septal wall. Clinical performance of MAR is assessed by two

  20. Impact of motion and partial volume effects correction on PET myocardial perfusion imaging using simultaneous PET-MR

    Science.gov (United States)

    Petibon, Yoann; Guehl, Nicolas J.; Reese, Timothy G.; Ebrahimi, Behzad; Normandin, Marc D.; Shoup, Timothy M.; Alpert, Nathaniel M.; El Fakhri, Georges; Ouyang, Jinsong

    2017-01-01

    PET is an established modality for myocardial perfusion imaging (MPI) which enables quantification of absolute myocardial blood flow (MBF) using dynamic imaging and kinetic modeling. However, heart motion and partial volume effects (PVE) significantly limit the spatial resolution and quantitative accuracy of PET MPI. Simultaneous PET-MR offers a solution to the motion problem in PET by enabling MR-based motion correction of PET data. The aim of this study was to develop a motion and PVE correction methodology for PET MPI using simultaneous PET-MR, and to assess its impact on both static and dynamic PET MPI using 18F-Flurpiridaz, a novel 18F-labeled perfusion tracer. Two dynamic 18F-Flurpiridaz MPI scans were performed on healthy pigs using a PET-MR scanner. Cardiac motion was tracked using a dedicated tagged-MRI (tMR) sequence. Motion fields were estimated using non-rigid registration of tMR images and used to calculate motion-dependent attenuation maps. Motion correction of PET data was achieved by incorporating tMR-based motion fields and motion-dependent attenuation coefficients into image reconstruction. Dynamic and static PET datasets were created for each scan. Each dataset was reconstructed as (i) Ungated, (ii) Gated (end-diastolic phase), and (iii) Motion-Corrected (MoCo), each without and with point spread function (PSF) modeling for PVE correction. Myocardium-to-blood concentration ratios (MBR) and apparent wall thickness were calculated to assess image quality for static MPI. For dynamic MPI, segment- and voxel-wise MBF values were estimated by non-linear fitting of a 2-tissue compartment model to tissue time-activity-curves. MoCo and Gating respectively decreased mean apparent wall thickness by 15.1% and 14.4% and increased MBR by 20.3% and 13.6% compared to Ungated images (P  <  0.01). Combined motion and PSF correction (MoCo-PSF) yielded 30.9% (15.7%) lower wall thickness and 82.2% (20.5%) higher MBR compared to Ungated data reconstructed

  1. Research Progress of Amino Acid Metabolism PET Imaging in Tumor

    Directory of Open Access Journals (Sweden)

    NIE Da-hong

    2015-11-01

    Full Text Available Amino acid metabolism PET imaging plays a very important role in metabolism molecular imaging. Amino acid PET tracers include [1-11C]amino acid, labeling α-C amino acid, labeling side-chain amino acid, and N-substituted labeling amino acid. Uptake mechanism of these amino acids in tumor mainly involves in amino acid transport and amino acid metabolism PET imaging has an advantage of differential diagnosis of neuropsychiatric diseases, brain cancer, neuroendocrine tumor, and other tumors. The research progress of amino acid metabolism PET imaging in tumor were summarized.

  2. Practical Considerations for Clinical PET/MR Imaging.

    Science.gov (United States)

    Galgano, Samuel; Viets, Zachary; Fowler, Kathryn; Gore, Lael; Thomas, John V; McNamara, Michelle; McConathy, Jonathan

    2018-01-01

    Clinical PET/MR imaging is currently performed at a number of centers around the world as part of routine standard of care. This article focuses on issues and considerations for a clinical PET/MR imaging program, focusing on routine standard-of-care studies. Although local factors influence how clinical PET/MR imaging is implemented, the approaches and considerations described here intend to apply to most clinical programs. PET/MR imaging provides many more options than PET/computed tomography with diagnostic advantages for certain clinical applications but with added complexity. A recurring theme is matching the PET/MR imaging protocol to the clinical application to balance diagnostic accuracy with efficiency. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    tomography ((18)F-FDG PET) in paediatric oncology. The Oncology Committee of the European Association of Nuclear Medicine (EANM) has published excellent procedure guidelines on tumour imaging with (18)F-FDG PET (Bombardieri et al., Eur J Nucl Med Mol Imaging 30:BP115-24, 2003). These guidelines, published...

  4. Reproducibility of Quantitative Brain Imaging Using a PET-Only and a Combined PET/MR System

    DEFF Research Database (Denmark)

    Lassen, Martin L; Muzik, Otto; Beyer, Thomas

    2017-01-01

    observed for kinetic parameters derived from emission data obtained from PET/MR and PET-only imaging due to different standard AC methods employed. Therefore, a transfer of imaging protocols from PET-only to PET/MR systems is not straightforward without application of proper correction methods...

  5. 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.

  6. Motion-Corrected Imaging of the Aortic Valve with (18)F-NaF PET/CT and PET/MRI: A Feasibility Study.

    Science.gov (United States)

    Doris, Mhairi K; Rubeaux, Mathieu; Pawade, Tania; Otaki, Yuka; Xie, Yibin; Li, Debiao; Tamarappoo, Balaji K; Newby, David E; Berman, Daniel S; Dweck, Marc R; Slomka, Piotr J; Dey, Damini

    2017-11-01

    We investigated whether motion correction of gated (18)F-fluoride PET/CT and PET/MRI of the aortic valve could improve PET quantitation and image quality. Methods: A diffeomorphic, mass-preserving, anatomy-guided registration algorithm was used to align the PET images from 4 cardiac gates, preserving all counts, and apply them to the PET/MRI and PET/CT data of 6 patients with aortic stenosis. Measured signal-to-noise ratios (SNRs) and target-to-background ratios (TBRs) were compared with the standard method of using only the diastolic gate. Results: High-intensity aortic valve (18)F-fluoride uptake was observed in all patients. After motion correction, SNR and TBR increased compared with the median diastolic gate (SNR, 51.61 vs. 21.0; TBR, 2.85 vs. 2.22) and the median summed data (SNR, 51.61 vs. 34.10; TBR, 2.85 vs. 1.95) (P = 0.028 for all). Furthermore, noise decreased from 0.105 (median, diastolic) to 0.042 (median, motion-corrected) (P = 0.028). Conclusion: Motion correction of hybrid (18)F-fluoride PET markedly improves SNR, resulting in improved image quality. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  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/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. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. 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.

  10. Development of a PET Scanner for Simultaneously Imaging Small Animals with MRI and PET

    Directory of Open Access Journals (Sweden)

    Christopher J Thompson

    2014-08-01

    Full Text Available Recently, positron emission tomography (PET is playing an increasingly important role in the diagnosis and staging of cancer. Combined PET and X-ray computed tomography (PET-CT scanners are now the modality of choice in cancer treatment planning. More recently, the combination of PET and magnetic resonance imaging (MRI is being explored in many sites. Combining PET and MRI has presented many challenges since the photo-multiplier tubes (PMT in PET do not function in high magnetic fields, and conventional PET detectors distort MRI images. Solid state light sensors like avalanche photo-diodes (APDs and more recently silicon photo-multipliers (SiPMs are much less sensitive to magnetic fields thus easing the compatibility issues. This paper presents the results of a group of Canadian scientists who are developing a PET detector ring which fits inside a high field small animal MRI scanner with the goal of providing simultaneous PET and MRI images of small rodents used in pre-clinical medical research. We discuss the evolution of both the crystal blocks (which detect annihilation photons from positron decay and the SiPM array performance in the last four years which together combine to deliver significant system performance in terms of speed, energy and timing resolution.

  11. APD-based PET detector for simultaneous PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Grazioso, Ronald [Siemens Molecular Imaging, Knoxville, TN (United States)]. E-mail: ron.grazioso@siemens.com; Zhang, Nan [Siemens Molecular Imaging, Knoxville, TN (United States); Corbeil, James [Siemens Molecular Imaging, Knoxville, TN (United States); Schmand, Matthias [Siemens Molecular Imaging, Knoxville, TN (United States); Ladebeck, Ralf [Siemens AG Medical Solutions MR, Erlangen (Germany); Vester, Markus [Siemens AG Medical Solutions MR, Erlangen (Germany); Schnur, Guenter [Siemens AG Medical Solutions MR, Erlangen (Germany); Renz, Wolfgang [Siemens AG Medical Solutions MR, Erlangen (Germany); Fischer, Hubertus [Siemens AG Medical Solutions MR, Erlangen (Germany)

    2006-12-20

    Two, APD-based, PET modules have been evaluated for use in combined PET/MR imaging. Each module consists of 4 independent, optically isolated detectors. Each detector consists of an 8x8 array of 2x2x20 mm LSO crystals read out by a 2x2 array of 5x5 mm Hamamatsu S8664-55 APDs. The average crystal energy resolution and time resolution (against a plastic scintillator on a PMT) of the detectors was 17% and 1.8 ns, respectively. The modules were positioned in the tunnel of a 1.5 T Siemens Symphony MR scanner. The presence of the PET modules decreased the MR signal-to-noise ratio by about 15% but no image interference was observed. The gradient and RF pulse sequences of the MR produced adverse effects on the PET event signals. These high-frequency pulses did not affect the true PET events but did increase the dead time of the PET system. Simultaneous, artifact-free, images were acquired with the PET and MR system using a small Derenzo phantom. These results show that APD-based PET detectors can be used for a high-resolution and cost-effective integrated PET/MR system.

  12. APD-based PET detector for simultaneous PET/MR imaging

    Science.gov (United States)

    Grazioso, Ronald; Zhang, Nan; Corbeil, James; Schmand, Matthias; Ladebeck, Ralf; Vester, Markus; Schnur, Günter; Renz, Wolfgang; Fischer, Hubertus

    2006-12-01

    Two, APD-based, PET modules have been evaluated for use in combined PET/MR imaging. Each module consists of 4 independent, optically isolated detectors. Each detector consists of an 8×8 array of 2×2×20 mm LSO crystals read out by a 2×2 array of 5×5 mm Hamamatsu S8664-55 APDs. The average crystal energy resolution and time resolution (against a plastic scintillator on a PMT) of the detectors was 17% and 1.8 ns, respectively. The modules were positioned in the tunnel of a 1.5 T Siemens Symphony MR scanner. The presence of the PET modules decreased the MR signal-to-noise ratio by about 15% but no image interference was observed. The gradient and RF pulse sequences of the MR produced adverse effects on the PET event signals. These high-frequency pulses did not affect the true PET events but did increase the dead time of the PET system. Simultaneous, artifact-free, images were acquired with the PET and MR system using a small Derenzo phantom. These results show that APD-based PET detectors can be used for a high-resolution and cost-effective integrated PET/MR system.

  13. Clinical PET/MR Imaging in Oncology: Future Perspectives.

    Science.gov (United States)

    Kjær, Andreas; Torigian, Drew A

    2016-10-01

    In 2011, the first fully integrated commercially available clinical PET/MR imaging systems became available, and the imaging community thought that these scanners would replace PET/CT systems. However, today a disappointing number of less than 100 scanners have been installed worldwide. The question, therefore, arises regarding what the future clinical applications of PET/MR imaging will be. In this article, the authors discuss ways in which PET/MR imaging may be used in future applications that justify the added cost, predominantly focusing on oncologic applications. The authors suggest that such areas include combined molecular and functional imaging, multimodality radiomics, and hyperPET. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. EANM/ESC guidelines for radionuclide imaging of cardiac function

    DEFF Research Database (Denmark)

    Hesse, B.; Lindhardt, T.B.; Acampa, W.

    2008-01-01

    Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibri......". The guidelines are designed to assist in the practice of referral to, performance, interpretation and reporting of nuclear cardiology studies for the evaluation of cardiac performance Udgivelsesdato: 2008/4......Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibrium...... radionuclide ventriculography, gated myocardial perfusion scintigraphy, gated PET, and studies with non-imaging devices for the evaluation of cardiac function. The items covered are presented in 11 sections: clinical indications, radiopharmaceuticals and dosimetry, study acquisition, RV EF, LV EF, LV volumes...

  15. Limitations of PET for imaging lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Barrington, Sally F.; O' Doherty, Michael J. [Clinical PET Centre of Guy' s and St Thomas' Hospitals, St Thomas' Hospital, SE1 7EH, London (United Kingdom)

    2003-06-01

    The uptake of fluorine-18 fluorodeoxyglucose (FDG) is increased in processes with enhanced glycolysis, including malignancy. It is this property of FDG which is exploited in positron emission tomography (PET) imaging for lymphoma. FDG, whilst a good oncology tracer, is not perfect and there are limitations to its use. FDG may have low uptake in some types of lymphoma, predominantly low-grade lymphomas. High physiological uptake may occur within the bowel, urinary tract, muscle, salivary glands and lymphoid tissue. FDG is not specific for malignancy and increased uptake occurs in benign conditions with increased glycolysis such as infection, inflammation and granulomatous disease. Benign conditions usually have lower uptake than malignancy but there is overlap. These limitations of FDG mean that tumour may be 'missed', 'masked' or 'mimicked' by other pathology. These limitations are described in this article and methods to circumvent them where possible are discussed. These include performing baseline scans at presentation with lymphoma for comparison with post-treatment scans, simple manoeuvres to reduce physiological uptake such as administration of frusemide and diazepam and remaining alert to the possibility of alternative pathology in immunosuppressed patients. Patients with disease secondary to human immunodeficiency virus are a particular challenge in this regard as they often have dual or multiple pathology. One of the most important skills in PET reporting may be to recognise its limitations and be clear when a definitive answer cannot be given to the referring clinician's question. This may require using PET to direct the clinician to biopsy the site most likely to yield the correct diagnosis. (orig.)

  16. First experience of simultaneous PET/MRI for the early detection of cardiac involvement in patients with Anderson-Fabry disease

    Energy Technology Data Exchange (ETDEWEB)

    Nappi, Carmela; Altiero, Michele; Imbriaco, Massimo; Giudice, Caterina Anna; Spinelli, Letizia; Cuocolo, Alberto [University Federico II, Department of Advanced Biomedical Sciences, Naples (Italy); Nicolai, Emanuele; Aiello, Marco; Diomiaiuti, Claudio Tommaso [IRCCS SDN, Naples (Italy); Pisani, Antonio [University Federico II, Department of Public Health, Naples (Italy)

    2015-03-26

    Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder associated with severe multiorgan dysfunction and premature death. Early diagnosis and treatment strategies play a key role in patient outcome. We investigated the potential role of hybrid PET/MR imaging in the assessment of early cardiac involvement in AFD patients. Thirteen AFD patients without cardiac symptoms and with normal left ventricular function underwent simultaneous cardiac PET/MR imaging after administration of {sup 18}F-FDG. Cardiac FDG uptake was quantified by measuring the standardized uptake value in 17 myocardial segments in each subject. The coefficient of variation (COV, i.e. the standard deviation divided by the average) of the uptake of the 17 segments was calculated as an index of heterogeneity in the heart. Six patients exhibited focal late gadolinium enhancement (LGE) indicating intramyocardial fibrosis, and four of these also had positive short inversion time inversion recovery (STIR) sequences. All patients with LGE and positive STIR MR images showed focal FDG uptake in the corresponding myocardial segments indicating inflammation. Of the seven patients with negative LGE and STIR images, five showed homogeneous FDG cardiac uptake and two showed heterogeneous FDG uptake. The COV was significantly greater in patients with focal FDG uptake (0.25 ± 0.02) than in those without (0.14 ± 0.07, p < 0.01). PET/MR imaging is clinically feasible for the early detection of cardiac involvement in patients with AFD. Further studies evaluating the role of hybrid PET/MR imaging in management of the disease in larger patient populations are warranted. (orig.)

  17. Validation of cardiac {sup 123}I-MIBG scintigraphy in patients with Parkinson's disease who were diagnosed with dopamine PET

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Kenji [Tokyo Medical and Dental University, Department of Neurology and Neurological Science, Graduate School, Tokyo (Japan); Tokyo Metropolitan Institute of Gerontology, Positron Medical Center, Tokyo (Japan); Saito, Yuko [Tokyo Metropolitan Geriatric Hospital, Department of Pathology, Tokyo (Japan); Tokyo Metropolitan Institute of Gerontology, Department of Neuropathology, Tokyo (Japan); Murayama, Shigeo [Tokyo Metropolitan Institute of Gerontology, Department of Neuropathology, Tokyo (Japan); Kanemaru, Kazutomi [Tokyo Metropolitan Geriatric Hospital, Department of Neurology, Tokyo (Japan); Oda, Keiichi; Ishiwata, Kiichi; Ishii, Kenji [Tokyo Metropolitan Institute of Gerontology, Positron Medical Center, Tokyo (Japan); Mizusawa, Hidehiro [Tokyo Medical and Dental University, Department of Neurology and Neurological Science, Graduate School, Tokyo (Japan)

    2010-01-15

    The aim of this study was to evaluate the diagnostic potential of cardiac {sup 123}I-labelled metaiodobenzylguanidine ({sup 123}I-MIBG) scintigraphy in idiopathic Parkinson's disease (PD). The diagnosis was confirmed by positron emission tomography (PET) imaging with {sup 11}C-labelled 2{beta}-carbomethoxy-3{beta}-(4-fluorophenyl)-tropane ({sup 11}C-CFT) and {sup 11}C-raclopride (together designated as dopamine PET). Cardiac {sup 123}I-MIBG scintigraphy and dopamine PET were performed for 39 parkinsonian patients. To estimate the cardiac {sup 123}I-MIBG uptake, heart to mediastinum (H/M) ratios in early and delayed images were calculated. On the basis of established clinical criteria and our dopamine PET findings, 24 patients were classified into the PD group and 15 into the non-PD (NPD) group. Both early and delayed images showed that the H/M ratios were significantly lower in the PD group than in the NPD group. When the optimal cut-off levels of the H/M ratio were set at 1.95 and 1.60 in the early and delayed images, respectively, by receiver-operating characteristic analysis, the sensitivity of cardiac {sup 123}I-MIBG scintigraphy for the diagnosis of PD was 79.2 and 70.8% and the specificity was 93.3 and 93.3% in the early and delayed images, respectively. In the Hoehn and Yahr 1 and 2 PD patients, the sensitivity decreased by 69.2 and 53.8% in the early and delayed images, respectively. In early PD cases, cardiac {sup 123}I-MIBG scintigraphy is of limited value in the diagnosis, because of its relatively lower sensitivity. However, because of its high specificity for the overall cases, cardiac {sup 123}I-MIBG scintigraphy may assist in the diagnosis of PD in a complementary role with the dopaminergic neuroimaging. (orig.)

  18. ENerGetIcs in hypertrophic cardiomyopathy: traNslation between MRI, PET and cardiac myofilament function (ENGINE study).

    Science.gov (United States)

    Güçlü, A; Germans, T; Witjas-Paalberends, E R; Stienen, G J M; Brouwer, W P; Harms, H J; Marcus, J T; Vonk, A B A; Stooker, W; Yilmaz, A; Klein, P; Ten Berg, J M; Kluin, J; Asselbergs, F W; Lammertsma, A A; Knaapen, P; van Rossum, A C; van der Velden, J

    2013-12-01

    Hypertrophic cardiomyopathy (HCM) is an autosomal dominant heart disease mostly due to mutations in genes encoding sarcomeric proteins. HCM is characterised by asymmetric hypertrophy of the left ventricle (LV) in the absence of another cardiac or systemic disease. At present it lacks specific treatment to prevent or reverse cardiac dysfunction and hypertrophy in mutation carriers and HCM patients. Previous studies have indicated that sarcomere mutations increase energetic costs of cardiac contraction and cause myocardial dysfunction and hypertrophy. By using a translational approach, we aim to determine to what extent disturbances of myocardial energy metabolism underlie disease progression in HCM. Hypertrophic obstructive cardiomyopathy (HOCM) patients and aortic valve stenosis (AVS) patients will undergo a positron emission tomography (PET) with acetate and cardiovascular magnetic resonance imaging (CMR) with tissue tagging before and 4 months after myectomy surgery or aortic valve replacement + septal biopsy. Myectomy tissue or septal biopsy will be used to determine efficiency of sarcomere contraction in-vitro, and results will be compared with in-vivo cardiac performance. Healthy subjects and non-hypertrophic HCM mutation carriers will serve as a control group. Our study will reveal whether perturbations in cardiac energetics deteriorate during disease progression in HCM and whether these changes are attributed to cardiac remodelling or the presence of a sarcomere mutation per se. In-vitro studies in hypertrophied cardiac muscle from HOCM and AVS patients will establish whether sarcomere mutations increase ATP consumption of sarcomeres in human myocardium. Our follow-up imaging study in HOCM and AVS patients will reveal whether impaired cardiac energetics are restored by cardiac surgery.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-15

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

  20. Ultrasound Imaging in Teaching Cardiac Physiology

    Science.gov (United States)

    Johnson, Christopher D.; Montgomery, Laura E. A.; Quinn, Joe G.; Roe, Sean M.; Stewart, Michael T.; Tansey, Etain A.

    2016-01-01

    This laboratory session provides hands-on experience for students to visualize the beating human heart with ultrasound imaging. Simple views are obtained from which students can directly measure important cardiac dimensions in systole and diastole. This allows students to derive, from first principles, important measures of cardiac function, such…

  1. 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

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

    NARCIS (Netherlands)

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

    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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  4. The effect of patient positioning aids on PET quantification in PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mantlik, Frederic; Hofmann, Matthias [University of Tuebingen, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Radiology, Tuebingen (Germany); Max Planck Institute for Biological Cybernetics, Tuebingen (Germany); Werner, Matthias K.; Sauter, Alexander [University Hospital, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Kupferschlaeger, Juergen [University Hospital, Department of Nuclear Medicine, Tuebingen (Germany); Schoelkopf, Bernhard [Max Planck Institute for Biological Cybernetics, Tuebingen (Germany); Pichler, Bernd J. [University of Tuebingen, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Radiology, Tuebingen (Germany); Beyer, Thomas [University Hospital, Imaging Science Institute, Tuebingen (Germany)

    2011-05-15

    Clinical PET/MR requires the use of patient positioning aids to immobilize and support patients for the duration of the combined examination. Ancillary immobilization devices contribute to overall attenuation of the PET signal, but are not detected with conventional MR sequences and, hence, are ignored in standard MR-based attenuation correction (MR-AC). We report on the quantitative effect of not accounting for the attenuation of patient positioning aids in combined PET/MR imaging. We used phantom and patient data acquired with positioning aids on a PET/CT scanner (Biograph 16, HI-REZ) to mimic PET/MR imaging conditions. Reference CT-based attenuation maps were generated from measured (original) CT transmission images (origCT-AC). We also created MR-like attenuation maps by following the same conversion procedure of the attenuation values except for the prior delineation and subtraction of the positioning aids from the CT images (modCT-AC). First, a uniform {sup 68}Ge cylinder was positioned centrally in the PET/CT scanner and fixed with a vacuum mattress (10 cm thick) and, in a repeat examination, with MR positioning foam pads. Second, 16 patient datasets were selected for subsequent processing. All patients were regionally immobilized with positioning aids: a vacuum mattress for head/neck imaging (nine patients) and a foam mattress for imaging of the lower extremities (seven patients). PET images were reconstructed following CT-based attenuation and scatter correction using the original and modified (MR-like) CT images: PET{sub origCT-AC} and PET{sub modCT-AC}, respectively. PET images following origCT-AC and modCT-AC were compared visually and in terms of mean differences of voxels with a standardized uptake value of at least 1.0. In addition, we report maximum activity concentration in lesions for selected patients. In the phantom study employing the vacuum mattress the average voxel activity in PET{sub modCT-AC} was underestimated by 6.4% compared to PET

  5. The effect of patient positioning aids on PET quantification in PET/MR imaging.

    Science.gov (United States)

    Mantlik, Frederic; Hofmann, Matthias; Werner, Matthias K; Sauter, Alexander; Kupferschläger, Jürgen; Schölkopf, Bernhard; Pichler, Bernd J; Beyer, Thomas

    2011-05-01

    Clinical PET/MR requires the use of patient positioning aids to immobilize and support patients for the duration of the combined examination. Ancillary immobilization devices contribute to overall attenuation of the PET signal, but are not detected with conventional MR sequences and, hence, are ignored in standard MR-based attenuation correction (MR-AC). We report on the quantitative effect of not accounting for the attenuation of patient positioning aids in combined PET/MR imaging. We used phantom and patient data acquired with positioning aids on a PET/CT scanner (Biograph 16, HI-REZ) to mimic PET/MR imaging conditions. Reference CT-based attenuation maps were generated from measured (original) CT transmission images (origCT-AC). We also created MR-like attenuation maps by following the same conversion procedure of the attenuation values except for the prior delineation and subtraction of the positioning aids from the CT images (modCT-AC). First, a uniform (68)Ge cylinder was positioned centrally in the PET/CT scanner and fixed with a vacuum mattress (10 cm thick) and, in a repeat examination, with MR positioning foam pads. Second, 16 patient datasets were selected for subsequent processing. All patients were regionally immobilized with positioning aids: a vacuum mattress for head/neck imaging (nine patients) and a foam mattress for imaging of the lower extremities (seven patients). PET images were reconstructed following CT-based attenuation and scatter correction using the original and modified (MR-like) CT images: PET(origCT-AC) and PET(modCT-AC), respectively. PET images following origCT-AC and modCT-AC were compared visually and in terms of mean differences of voxels with a standardized uptake value of at least 1.0. In addition, we report maximum activity concentration in lesions for selected patients. In the phantom study employing the vacuum mattress the average voxel activity in PET(modCT-AC) was underestimated by 6.4% compared to PET(origCT-AC), with 3

  6. Clinical evaluation of PET image quality as a function of acquisition time in a new TOF-PET/MR compared to TOF-PET/CT - initial results

    Energy Technology Data Exchange (ETDEWEB)

    Zeimpekis, Konstantinos; Huellner, Martin; De Galiza Barbosa, Felipe; Ter Voert, Edwin; Davison, Helen; Delso, Gaspar; Veit-Haibach, Patrick [Nuclear Medicine, University Hospital Zurich (Switzerland)

    2015-05-18

    The recently available integrated PET/MR imaging can offer significant additional advances in clinical imaging. The purpose of this study was to compare the PET performance between a PET/CT scanner and an integrated TOF-PET/MR scanner concerning image quality parameters and quantification in terms of SUV as a function of acquisition time (a surrogate of dose). Five brain and five whole body patients were included in the study. The PET/CT scan was used as a reference and the PET/MR acquisition time was consecutively adjusted, taking into account the decay between the scans in order to expose both systems to the same amount of emitted signal. The acquisition times were then retrospectively reduced to assess the performance of the PET/MRI for lower count rates. Image quality, image sharpness, artifacts and noise were evaluated. SUV measurements were taken in the liver and in white matter to compare quantification. Quantitative evaluation showed good correlation between PET/CT and PET/MR brain SUVs. Liver correlation was lower, with uptake underestimation in PET/MR, partially justified by bio-redistribution. The clinical evaluation showed that PET/MR offers higher image quality and sharpness with lower levels of noise and artefacts compared to PET/CT with reduced acquisition times for whole body scans, while for brain scans there is no significant difference. The PET-component of the TOF-PET/MR showed higher image quality compared to PET/CT as tested with reduced imaging times. However, these results account mainly for body imaging, while no significant difference were found in brain imaging. This overall higher image quality suggests that the acquisition time or injected activity can be reduced by at least 37% on the PET/MR scanner.

  7. [Non-invasive evaluation of the cardiac autonomic nervous system by PET]. Progress report, September 1991--September 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-09-01

    The proposed research addresses the development, validation and application of cardiac PET imaging techniques to characterize the autonomic nervous system of the heart. PET technology has significantly matured over the last two decades. Instrument design, image processing and production of radiochemical compounds have formed an integrative approach to provide a powerful and novel imaging modality for the quantitative in vivo evaluation of the autonomic nervous system of the heart. Animal studies using novel tracers for the sympathetic and parasympathetic nerve terminals will be employed to characterize the functional integrity of nerve terminals. This work will be complemented by the development of agents which bind to postsynaptic receptor sites. The combined evaluation of presynaptic and postsynaptic neuronal function will allow a unique characterization of neuronal function. Initial development in animal studies will be followed by feasibility studies in humans. These studies are designed to test sophisticated imaging protocols in the human heart and validate the scintigraphic findings with independent markers of autonomic innervation. Subsequent clinical application in various cardiac diseases is expected to provide new insights into the neuropathophysiology of the heart.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-15

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

  9. 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

  10. Assessment of the diagnostic accuracy of {sup 18}F-FDG PET/CT in prosthetic infective endocarditis and cardiac implantable electronic device infection: comparison of different interpretation criteria

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Ballve, Ana; Jesus Perez-Castejon, Maria; Carreras-Delgado, Jose L. [Clinico San Carlos University Hospital, San Carlos Health Research Institute (IdISSC), Complutense University of Madrid, Department of Nuclear Medicine, Madrid (Spain); Delgado-Bolton, Roberto C. [Clinico San Carlos University Hospital, San Carlos Health Research Institute (IdISSC), Complutense University of Madrid, Department of Nuclear Medicine, Madrid (Spain); San Pedro Hospital and Centre for Biomedical Research of La Rioja (CIBIR), University of La Rioja, Department of Diagnostic Imaging (Radiology) and Nuclear Medicine, La Rioja (Spain); Sanchez-Enrique, Cristina; Vilacosta, Isidre; Vivas, David; Olmos, Carmen [Clinico San Carlos University Hospital, Department of Cardiology, Madrid (Spain); Ferrer, Manuel E.F. [Clinico San Carlos University Hospital, Research Unit, Madrid (Spain)

    2016-12-15

    The diagnosis of prosthetic valve (PV) infective endocarditis (IE) and infection of cardiac implantable electronic devices (CIEDs) remains challenging. The aim of this study was to assess the usefulness of {sup 18}F-FDG PET/CT in these patients and analyse the interpretation criteria. We included 41 patients suspected of having IE by the Duke criteria who underwent {sup 18}F-FDG PET/CT. The criteria applied for classifying the findings as positive/negative for IE were: (a) visual analysis of only PET images with attenuation-correction (AC PET images); (b) visual analysis of both AC PET images and PET images without AC (NAC PET images); (c) qualitative analysis of NAC PET images; and (d) semiquantitative analysis of AC PET images. {sup 18}F-FDG PET/CT was considered positive for IE independently of the intensity and distribution of FDG uptake. The gold standard was the Duke pathological criteria (if tissue was available) or the decision of an endocarditis expert team after a minimum 4 months follow-up. We studied 62 areas with suspicion of IE, 28 areas (45 %) showing definite IE and 34 (55 %) showing possible IE. Visual analysis of only AC PET images showed poor diagnostic accuracy (sensitivity 20 %, specificity 57 %). Visual analysis of both AC PET and NAC PET images showed excellent sensitivity (100 %) and intermediate specificity (73 %), focal uptake being more frequently associated with IE. The accuracy of qualitative analysis of NAC PET images depended on the threshold: the maximum sensitivity, specificity and accuracy achieved were 88 %, 80 %, 84 %, respectively. In the semiquantitative analysis of AC PET images, SUVmax was higher in areas of confirmed IE than in those without IE (∇SUVmax 2.2, p < 0.001). When FDG uptake was twice that in the liver, IE was always confirmed, and SUVmax 5.5 was the optimal threshold for IE diagnosis using ROC curve analysis (area under the curve 0.71). The value of {sup 18}F-FDG PET/CT in the diagnosis of suspected IE of PVs

  11. 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.)

  12. 18F-FDOPA PET Imaging in Prolactinoma.

    Science.gov (United States)

    Ginet, Merwan; Cuny, Thomas; Schmitt, Emmanuelle; Marie, Pierre-Yves; Verger, Antoine

    2017-08-01

    Pituitary macroadenoma constitutes a frequently misdiagnosed benign tumor. We report herein a case where such macroadenoma, a prolactinoma, was incidentally discovered in a 63-year-old man who had been referred to F-FDG PET and F-FDOPA PET imaging for a pharmacoresistant epilepsy. An increased uptake was documented for both radiotracers within the sellar region, although with a much higher contrast for F-FDOPA than for F-FDG. This case presents an increased uptake documented within a prolactinoma owing to the high contrast and image quality provided by F-FDOPA PET.

  13. Evaluation of image registration in PET/CT of the liver and recommendations for optimized imaging.

    NARCIS (Netherlands)

    Vogel, W.V.; Dalen, J.A. van; Wiering, B.; Huisman, H.J.; Corstens, F.H.M.; Ruers, T.J.M.; Oyen, W.J.G.

    2007-01-01

    Multimodality PET/CT of the liver can be performed with an integrated (hybrid) PET/CT scanner or with software fusion of dedicated PET and CT. Accurate anatomic correlation and good image quality of both modalities are important prerequisites, regardless of the applied method. Registration accuracy

  14. Development of a PET-Transrectal Ultrasound Prostate Imaging System

    Science.gov (United States)

    Huber, Jennifer S.; Peng, Qiyu.; Moses, William W.; Reutter, Bryan W.; Pouliot, Jean; Hsu, I. Chow

    2011-06-01

    Multimodality imaging has an increasing role in the management of a large number of diseases, particularly if both functional and structural information are acquired and accurately registered. Transrectal ultrasound (TRUS) imaging is currently an integral part of prostate cancer diagnosis and treatment procedures, providing high-resolution anatomical detail of the prostate region. Positron Emission Tomography (PET) imaging with 11C-choline is a sensitive functional imaging technique that can identify biochemical states associated with prostate cancer. We believe that merging these prostate imaging technologies will help identify the location and aggressiveness of prostate cancer. We envision using dual PET-TRUS prostate imaging to guide biopsy, guide treatment procedures, and detect local recurrence earlier than is currently possible. Hence, we have developed a dual PET-TRUS prostate imaging system and protocol designed to allow accurate 3-D image registration. We have evaluated this PET-TRUS system by performing dual PET-TRUS imaging of custom phantoms. We describe here our dual-modality imaging system, custom phantoms and phantom study results. We also discuss our investigation of the PET-TRUS registration accuracy. We measure an average PET-TRUS registration error for our phantom studies of 2.1 ±1.7 mm in the x direction, 1.9 ±1.6 mm in the y direction, and 0.6 ±0.2 mm in the z direction. This registration accuracy is sufficient for some clinical applications such as biopsy guidance and early detection of recurrence.

  15. Role of Cardiac MR Imaging in Cardiomyopathies.

    Science.gov (United States)

    Kramer, Christopher M

    2015-06-01

    Cardiac MR imaging has made major inroads in the new millennium in the diagnosis and assessment of prognosis for patients with cardiomyopathies. Imaging of left and right ventricular structure and function and tissue characterization with late gadolinium enhancement (LGE) as well as T1 and T2 mapping enable accurate diagnosis of the underlying etiology. In the setting of coronary artery disease, either transmurality of LGE or contractile reserve in response to dobutamine can assess the likelihood of recovery of function after revascularization. The presence of scar reduces the likelihood of a response to medical therapy and to cardiac resynchronization therapy in heart failure. The presence and extent of LGE relate to overall cardiovascular outcome in cardiomyopathies. A major role for cardiac MR imaging in cardiomyopathies is to identify myocardial scar for diagnostic and prognostic purposes. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  16. Quantifying hypoxia in human cancers using static PET imaging

    Science.gov (United States)

    Taylor, Edward; Yeung, Ivan; Keller, Harald; Wouters, Bradley G.; Milosevic, Michael; Hedley, David W.; Jaffray, David A.

    2016-11-01

    Compared to FDG, the signal of 18F-labelled hypoxia-sensitive tracers in tumours is low. This means that in addition to the presence of hypoxic cells, transport properties contribute significantly to the uptake signal in static PET images. This sensitivity to transport must be minimized in order for static PET to provide a reliable standard for hypoxia quantification. A dynamic compartmental model based on a reaction-diffusion formalism was developed to interpret tracer pharmacokinetics and applied to static images of FAZA in twenty patients with pancreatic cancer. We use our model to identify tumour properties—well-perfused without substantial necrosis or partitioning—for which static PET images can reliably quantify hypoxia. Normalizing the measured activity in a tumour voxel by the value in blood leads to a reduction in the sensitivity to variations in ‘inter-corporal’ transport properties—blood volume and clearance rate—as well as imaging study protocols. Normalization thus enhances the correlation between static PET images and the FAZA binding rate K 3, a quantity which quantifies hypoxia in a biologically significant way. The ratio of FAZA uptake in spinal muscle and blood can vary substantially across patients due to long muscle equilibration times. Normalized static PET images of hypoxia-sensitive tracers can reliably quantify hypoxia for homogeneously well-perfused tumours with minimal tissue partitioning. The ideal normalizing reference tissue is blood, either drawn from the patient before PET scanning or imaged using PET. If blood is not available, uniform, homogeneously well-perfused muscle can be used. For tumours that are not homogeneously well-perfused or for which partitioning is significant, only an analysis of dynamic PET scans can reliably quantify hypoxia.

  17. Clinical Evaluation of PET Image Quality as a Function of Acquisition Time in a New TOF-PET/MRI Compared to TOF-PET/CT--Initial Results.

    Science.gov (United States)

    Zeimpekis, Konstantinos G; Barbosa, Felipe; Hüllner, Martin; ter Voert, Edwin; Davison, Helen; Veit-Haibach, Patrick; Delso, Gaspar

    2015-10-01

    The purpose of this study was to compare only the performance of the PET component between a TOF-PET/CT (henceforth noted as PET/CT) scanner and an integrated TOF-PET/MRI (henceforth noted as PET/MRI) scanner concerning image quality parameters and quantification in terms of standardized uptake value (SUV) as a function of acquisition time (a surrogate of dose). The CT and MR image quality were not assessed, and that is beyond the scope of this study. Five brain and five whole-body patients were included in the study. The PET/CT scan was used as a reference and the PET/MRI acquisition time was consecutively adjusted, taking into account the decay between the scans in order to expose both systems to the same amount of the emitted signal. The acquisition times were then retrospectively reduced to assess the performance of the PET/MRI for lower count rates. Image quality, image sharpness, artifacts, and noise were evaluated. SUV measurements were taken in the liver and in the white matter to compare quantification. Quantitative evaluation showed strong correlation between PET/CT and PET/MRI brain SUVs. Liver correlation was good, however, with lower uptake estimation in PET/MRI, partially justified by bio-redistribution. The clinical evaluation showed that PET/MRI offers higher image quality and sharpness with lower levels of noise and artifacts compared to PET/CT with reduced acquisition times for whole-body scans while for brain scans there is no significant difference. The TOF-PET/MRI showed higher image quality compared to TOF-PET/CT as tested with reduced imaging times. However, this result accounts mainly for body imaging, while no significant differences were found in brain imaging.

  18. Automated Segmentation of Cardiac Magnetic Resonance Images

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Nilsson, Jens Chr.; Grønning, Bjørn A.

    2001-01-01

    Magnetic resonance imaging (MRI) has been shown to be an accurate and precise technique to assess cardiac volumes and function in a non-invasive manner and is generally considered to be the current gold-standard for cardiac imaging [1]. Measurement of ventricular volumes, muscle mass and function...... is based on determination of the left-ventricular endocardial and epicardial borders. Since manual border detection is laborious, automated segmentation is highly desirable as a fast, objective and reproducible alternative. Automated segmentation will thus enhance comparability between and within cardiac...... studies and increase accuracy by allowing acquisition of thinner MRI-slices. This abstract demonstrates that statistical models of shape and appearance, namely the deformable models: Active Appearance Models, can successfully segment cardiac MRIs....

  19. Optimization of yttrium-90 PET for simultaneous PET/MR imaging: A phantom study.

    Science.gov (United States)

    Eldib, Mootaz; Oesingmann, Niels; Faul, David D; Kostakoglu, Lale; Knešaurek, Karin; Fayad, Zahi A

    2016-08-01

    Positron emission tomography (PET) imaging of yttrium-90 in the liver post radioembolization has been shown useful for personalized dosimetry calculations and evaluation of extrahepatic deposition. The purpose of this study was to quantify the benefits of several MR-based data correction approaches offered by using a combined PET/MR system to improve Y-90 PET imaging. In particular, the feasibility of motion and partial volume corrections were investigated in a controlled phantom study. The ACR phantom was filled with an initial concentration of 8 GBq of Y-90 solution resulting in a contrast of 10:1 between the hot cylinders and the background. Y-90 PET motion correction through motion estimates from MR navigators was evaluated by using a custom-built motion stage that simulated realistic amplitudes of respiration-induced liver motion. Finally, the feasibility of an MR-based partial volume correction method was evaluated using a wavelet decomposition approach. Motion resulted in a large (∼40%) loss of contrast recovery for the 8 mm cylinder in the phantom, but was corrected for after MR-based motion correction was applied. Partial volume correction improved contrast recovery by 13% for the 8 mm cylinder. MR-based data correction improves Y-90 PET imaging on simultaneous PET/MR systems. Assessment of these methods must be studied further in the clinical setting.

  20. Cardiac 99mTc sestamibi SPECT and 18F FDG PET as viability markers in takotsubo cardiomyopathy

    DEFF Research Database (Denmark)

    Christensen, Thomas Emil; Bang, Lia Evi; Holmvang, Lene

    2014-01-01

    In patients with heart failure (HF) due to coronary disease, a combined evaluation of perfusion and glucose metabolism by cardiac single photon emission computed tomography (SPECT)/positron emission tomography (PET) can be used to distinguish viable from non-viable myocardium, and current...... guidelines recommend cardiac SPECT and fluorodeoxyglucose (FDG) PET for viability assessment. Takotsubo cardiomyopathy (TTC) is a disease characterized by acute but reversible HF leaving no scarring. To explore how robust the semi-quantitative viability criteria used in cardiac SPECT and FDG PET stands...

  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...

  2. Functional imaging in extrapulmonary sarcoidosis: FDG-PET/CT and MR features.

    Science.gov (United States)

    Soussan, Michael; Augier, Alexandre; Brillet, Pierre-Yves; Weinmann, Pierre; Valeyre, Dominique

    2014-02-01

    Sarcoidosis is a multiorgan granulomatous disease of unknown etiology that primarily involves the lungs and the lymphatic system. Extrapulmonary sarcoidosis is common, occurring in 30 to 50% of patients. In this review, we describe and illustrate the role of F-FDG PET/CT and MR imaging in patients with extrapulmonary sarcoidosis. FDG-PET/CT and MR can improve the accuracy of the diagnosis of extrapulmonary involvement, specify the respective contributions of active and fibrotic components of lesions, guide the selection of the biopsy site, provide prognostic information, and guide therapeutic management. We focus on suggestive patterns that help to improve lesion characterization, especially when these lesions are clinically occult. In cardiac sarcoidosis, the combined use of FDG-PET/CT and cardiac MR may provide optimal detection of the disease by enabling the differentiation between patients with active granulomatous inflammation and those with fibrous lesions. In cases with central nervous system involvement, the T2 hypointensity of the dural and parenchymal lesions is helpful for identifying sarcoidosis. Granulomatous bone marrow infiltration in the axial skeleton can be sensitively detected by both FDG-PET/CT and MR. Muscular sarcoidosis can have a characteristic appearance with the "dark star" sign on MR and a thick linear FDG uptake that predominantly involves the lower legs, designated as the "tiger man" sign. Extrathoracic lymphadenopathy is commonly observed on FDG-PET/CT imaging; however, its features are not specific, and the differentiation of extrathoracic lymphadenopathy from metastatic disease, tuberculosis, or lymphoma may be difficult. Familiarity with the functional imaging features in extrapulmonary sarcoidosis in various anatomical locations plays a crucial role in the diagnosis and management of patients.

  3. 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.

  4. PKU-PET-II: A novel SiPM-based PET imaging system for small animals

    Science.gov (United States)

    Xie, Zhaoheng; Li, Suying; Zhou, Kun; Vuletic, Ivan; Meng, Xiangxi; Zhu, Sihao; Xu, Huan; Yang, Kun; Xu, Baixuan; Zhang, Jinming; Ren, Qiushi

    2018-01-01

    The objective of this study was to introduce, describe, and validate the performance of a novel preclinical silicon photomultiplier (SiPM)-based PET system (PKU-PET-II). Briefly, the detector assembly consisted of cerium-doped lutetium-yttrium oxyorthosilicate (LYSO) crystals, with dimensions of 2 ×2 ×15 mm3, that offered a 60 mm transaxial field of view (FOV) and 32 mm axial FOV, respectively. The compact front-end electronics readout and digital controller implemented architecture in the FPGA were noteworthy improvements in PKU-PET-II over its predecessor (PKU-PET-I). Based on the National Electrical Manufacturers Association (NEMA) NU 04-2008 standards, the design of the PKU-PET-II system was validated by a phantom experiment. The results presented spatial resolution (evaluated as full width at half maximum) with a system range from 1.68 ±0.07 to 2.31 ±0.03 mm at the FOV center and from 1.43 ±0.02 to 2.10 ±0.10 mm at the 1/4th axial FOV, respectively. The system's absolute sensitivity at the center position was 1.35% with the coincidence window of 6 ns and energy window of 300-700 keV. In addition, the NEMA image quality phantom and an animal study results validated the system imaging performance in preclinical imaging application. In conclusion, this SiPM-based, small-animal PET system (PKU-PET-II) provided higher-resolution, adequate sensitivity, and excellent image quality and has potential as a useful tool for real-time imaging of disease progression and development in vivo.

  5. Development of compact DOI-measurable PET detectors for simultaneous PET/MR Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yiping; Sun, Xishan [University of Texas MD Anderson Cancer Center (United States); Lou, Kai [Rice University (United States)

    2015-05-18

    It is critically needed yet challenging to develop compact PET detectors with high sensitivity and uniform, high imaging resolution for improving the performance of simultaneous PET/MR imaging, particularly for an integrated/inserted small-bore system. Using the latest “edge-less” SiPM arrays for DOI measurement using the design of dual-ended-scintillator readout, we developed several compact PET detectors suited for PET/MR imaging. Each detector consists of one LYSO array with each end coupled to a SiPM array. Multiple detectors can be seamlessly tiled together along all sides to form a large detector panel. Detectors with 1.5x1.5 and 2.0x2.0 mm crystals at 20 or 30 mm lengths were studied. Readout of individual SiPM or capacitor-based signal multiplexing was used to transfer 3D interaction position-coded analog signals through flexible-print-circuit cables to dedicated ASIC frontend electronics to output digital timing pulses that encode interaction information. These digital pulses can be transferred to, through standard LVDS cables, and decoded by a FPGA-based data acquisition positioned outside the MRI scanner for coincidence event selection. Initial detector performance measurement shows excellent crystal identification even with 30 mm long crystals, ~18% and 2.8 ns energy and timing resolutions, and around 2-3 mm DOI resolution. A large size detector panel can be scaled up with these modular detectors and different PET systems can be flexibly configured with the scalable readout electronics and data acquisition, providing an important design advantage for different system and application requirements. It is expected that standard shielding of detectors, electronics and signal transfer lines can be applied for simultaneous PET/MR imaging applications, with desired DOI measurement capability to enhance the PET performance and image quality.

  6. Reproducibility of Quantitative Brain Imaging Using a PET-Only and a Combined PET/MR System.

    Science.gov (United States)

    Lassen, Martin L; Muzik, Otto; Beyer, Thomas; Hacker, Marcus; Ladefoged, Claes Nøhr; Cal-González, Jacobo; Wadsak, Wolfgang; Rausch, Ivo; Langer, Oliver; Bauer, Martin

    2017-01-01

    The purpose of this study was to test the feasibility of migrating a quantitative brain imaging protocol from a positron emission tomography (PET)-only system to an integrated PET/MR system. Potential differences in both absolute radiotracer concentration as well as in the derived kinetic parameters as a function of PET system choice have been investigated. Five healthy volunteers underwent dynamic (R)-[11C]verapamil imaging on the same day using a GE-Advance (PET-only) and a Siemens Biograph mMR system (PET/MR). PET-emission data were reconstructed using a transmission-based attenuation correction (AC) map (PET-only), whereas a standard MR-DIXON as well as a low-dose CT AC map was applied to PET/MR emission data. Kinetic modeling based on arterial blood sampling was performed using a 1-tissue-2-rate constant compartment model, yielding kinetic parameters (K1 and k2) and distribution volume (V T ). Differences for parametric values obtained in the PET-only and the PET/MR systems were analyzed using a 2-way Analysis of Variance (ANOVA). Comparison of DIXON-based AC (PET/MR) with emission data derived from the PET-only system revealed average inter-system differences of -33 ± 14% (p PET/MR resulted in slightly lower systematic differences of -16 ± 18% for K1 and -9 ± 10% for k2. The average differences in V T were -18 ± 10% (p PET/MR and PET-only imaging due to different standard AC methods employed. Therefore, a transfer of imaging protocols from PET-only to PET/MR systems is not straightforward without application of proper correction methods. Clinical Trial Registration: www.clinicaltrialsregister.eu, identifier 2013-001724-19.

  7. Reproducibility of Quantitative Brain Imaging Using a PET-Only and a Combined PET/MR System

    Science.gov (United States)

    Lassen, Martin L.; Muzik, Otto; Beyer, Thomas; Hacker, Marcus; Ladefoged, Claes Nøhr; Cal-González, Jacobo; Wadsak, Wolfgang; Rausch, Ivo; Langer, Oliver; Bauer, Martin

    2017-01-01

    The purpose of this study was to test the feasibility of migrating a quantitative brain imaging protocol from a positron emission tomography (PET)-only system to an integrated PET/MR system. Potential differences in both absolute radiotracer concentration as well as in the derived kinetic parameters as a function of PET system choice have been investigated. Five healthy volunteers underwent dynamic (R)-[11C]verapamil imaging on the same day using a GE-Advance (PET-only) and a Siemens Biograph mMR system (PET/MR). PET-emission data were reconstructed using a transmission-based attenuation correction (AC) map (PET-only), whereas a standard MR-DIXON as well as a low-dose CT AC map was applied to PET/MR emission data. Kinetic modeling based on arterial blood sampling was performed using a 1-tissue-2-rate constant compartment model, yielding kinetic parameters (K1 and k2) and distribution volume (VT). Differences for parametric values obtained in the PET-only and the PET/MR systems were analyzed using a 2-way Analysis of Variance (ANOVA). Comparison of DIXON-based AC (PET/MR) with emission data derived from the PET-only system revealed average inter-system differences of −33 ± 14% (p PET/MR resulted in slightly lower systematic differences of −16 ± 18% for K1 and −9 ± 10% for k2. The average differences in VT were −18 ± 10% (p PET/MR and PET-only imaging due to different standard AC methods employed. Therefore, a transfer of imaging protocols from PET-only to PET/MR systems is not straightforward without application of proper correction methods. Clinical Trial Registration: www.clinicaltrialsregister.eu, identifier 2013-001724-19 PMID:28769742

  8. Automated Quantitative Analysis of Cardiac Medical Images

    OpenAIRE

    Ding, Xiaowei

    2015-01-01

    Studies in clinical medicine often demand the quantitative analysis of medical images. These tasks need careful and time-consuming tracing and labeling on fine image structures, cost expensive medical expert labor and often suffer from low reproducibility. We present a collection of methods that quantify important parameters from cardiac computed tomography (CT) and magnetic resonance imaging (MRI) in a fully-automated mode. We first present atlas-based segmentation, active contours models an...

  9. Evaluation of a silicon photomultiplier PET insert for simultaneous PET and MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Guen Bae; Kim, Kyeong Yun; Yoon, Hyun Suk; Son, Jeong-Whan [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Lee, Min Sun [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Im, Hyung-Jun [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Lee, Jae Sung, E-mail: jaes@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of)

    2016-01-15

    Purpose: In this study, the authors present a silicon photomultiplier (SiPM)-based positron emission tomography (PET) insert dedicated to small animal imaging with high system performance and robustness to temperature change. Methods: The insert consists of 64 LYSO-SiPM detector blocks arranged in 4 rings of 16 detector blocks to yield a ring diameter of 64 mm and axial field of view of 55 mm. Each detector block consists of a 9 × 9 array of LYSO crystals (1.2 × 1.2 × 10 mm{sup 3}) and a monolithic 4 × 4 SiPM array. The temperature of each monolithic SiPM is monitored, and the proper bias voltage is applied according to the temperature reading in real time to maintain uniform performance. The performance of this PET insert was characterized using National Electrical Manufacturers Association NU 4-2008 standards, and its feasibility was evaluated through in vivo mouse imaging studies. Results: The PET insert had a peak sensitivity of 3.4% and volumetric spatial resolutions of 1.92 (filtered back projection) and 0.53 (ordered subset expectation maximization) mm{sup 3} at center. The peak noise equivalent count rate and scatter fraction were 42.4 kcps at 15.08 MBq and 16.5%, respectively. By applying the real-time bias voltage adjustment, an energy resolution of 14.2% ± 0.3% was maintained and the count rate varied ≤1.2%, despite severe temperature changes (10–30 °C). The mouse imaging studies demonstrate that this PET insert can produce high-quality images useful for imaging studies on the small animals. Conclusions: The developed MR-compatible PET insert is designed for insertion into a narrow-bore magnetic resonance imaging scanner, and it provides excellent imaging performance for PET/MR preclinical studies.

  10. 82Rb Cardiac PET in patients with known ischemic heart disease – a direct comparison with 15O-water Cardiac PET

    DEFF Research Database (Denmark)

    Hoff, Camilla Molich; Tolbod, Lars Poulsen; Harms, Hans

    2017-01-01

    Objectives Due to incomplete extraction, corrections are required when using 82Rb for absolute MBF measurements. Previous studies have established these corrections based on healthy subjects, however, the performance in patients with pathologically reduced MBF has only been studied in few...... individuals. In this study, we compared 82Rb cardiac PET with the non-invasive gold standard for absolute blood flow quantification, 15O-water, in patients with known ischemic heart disease (IHD). Methods Thirty-nine patients with known IHD referred to 82Rb PET were included in the study. Each patient...... for both tracers and the extraction correction by Lortie et al for 82Rb. Comparisons included 1) correlation of absolute MBF for 82Rb versus 15O-water, 2) standard clinical practice for 82Rb using assessment of static, gated and dynamic scans by 2 experienced physicians (consensus), 3) in-house established...

  11. 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.

  12. FDG PET/CT imaging in canine cancer patients

    DEFF Research Database (Denmark)

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

    2011-01-01

    .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...... 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...

  13. Myocardial wall motion imaging with cardiac magnetic resonance imaging

    NARCIS (Netherlands)

    Lubbers, Dani�l; Kuijpers, D.; Oudkerk, M.

    2006-01-01

    Wall motion imaging with cardiac magnetic resonance imaging (CMR) provides important functional information about global and regional myocardial function. This review will give an overview of the current state of myocardial wall motion imaging, especially focusing on the clinical role of dobutamine

  14. Compact and mobile high resolution PET brain imager

    Science.gov (United States)

    Majewski, Stanislaw [Yorktown, VA; Proffitt, James [Newport News, VA

    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.

  15. 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

  16. PET/MR imaging of atherosclerosis: initial experience and outlook.

    Science.gov (United States)

    Rischpler, Christoph; Nekolla, Stephan G; Beer, Ambros J

    2013-01-01

    Hybrid scanners such as PET/CT have in the past emerged as a valuable modality in clinical routine as well as an important research tool. Recently, the newly developed fully integrated PET/MR scanners were introduced to the market, raising high expectations especially due to the excellent soft tissue contrast and functional imaging capabilities of MRI. In this issue of the American Journal of Nuclear Medicine and Molecular Imaging, initial experiences using a hybrid PET/MR scanner for carotid artery imaging in a group of patients with increased risk for atherosclerosis are described. This represents a proof-of-principle study, which could stimulate future applications of this powerful modality in atherosclerotic plaque imaging.

  17. Cardiac MR imaging: current status and future direction

    Science.gov (United States)

    Van, Tu Anh; Krug, Roland; Hetts, Steven W.; Wilson, Mark W.

    2015-01-01

    Coronary artery disease is currently a worldwide epidemic with increasing impact on healthcare systems. Magnetic resonance imaging (MRI) sequences give complementary information on LV function, regional perfusion, angiogenesis, myocardial viability and orientations of myocytes. T2-weighted short-tau inversion recovery (T2-STIR), fat suppression and black blood sequences have been frequently used for detecting edematous area at risk (AAR) of infarction. T2 mapping, however, indicated that the edematous reaction in acute myocardial infarct (AMI) is not stable and warranted the use of edematous area in evaluating therapies. On the other hand, cine MRI demonstrated reproducible data on LV function in healthy volunteers and LV remodeling in patients. Noninvasive first pass perfusion, using exogenous tracer (gadolinium-based contrast media) and arterial spin labeling MRI, using endogenous tracer (water), are sensitive and useful techniques for evaluating myocardial perfusion and angiogenesis. Recently, new strategies have been developed to quantify myocardial viability using T1-mapping and equilibrium contrast enhanced MR techniques because existing delayed contrast enhancement MRI (DE-MRI) sequences are limited in detecting patchy microinfarct and diffuse fibrosis. These new techniques were successfully used for characterizing diffuse myocardial fibrosis associated with myocarditis, amyloidosis, sarcoidosis heart failure, aortic hypertrophic cardiomyopathy, congenital heart disease, restrictive cardiomyopathy, arrhythmogenic right ventricular dysplasia and hypertension). Diffusion MRI provides information regarding microscopic tissue structure, while diffusion tensor imaging (DTI) helps to characterize the myocardium and monitor the process of LV remodeling after AMI. Novel trends in hybrid imaging, such as cardiac positron emission tomography (PET)/MRI and optical imaging/MRI, are recently under intensive investigation. With the promise of higher spatial

  18. Cardiac MR imaging: current status and future direction.

    Science.gov (United States)

    Saeed, Maythem; Van, Tu Anh; Krug, Roland; Hetts, Steven W; Wilson, Mark W

    2015-08-01

    Coronary artery disease is currently a worldwide epidemic with increasing impact on healthcare systems. Magnetic resonance imaging (MRI) sequences give complementary information on LV function, regional perfusion, angiogenesis, myocardial viability and orientations of myocytes. T2-weighted short-tau inversion recovery (T2-STIR), fat suppression and black blood sequences have been frequently used for detecting edematous area at risk (AAR) of infarction. T2 mapping, however, indicated that the edematous reaction in acute myocardial infarct (AMI) is not stable and warranted the use of edematous area in evaluating therapies. On the other hand, cine MRI demonstrated reproducible data on LV function in healthy volunteers and LV remodeling in patients. Noninvasive first pass perfusion, using exogenous tracer (gadolinium-based contrast media) and arterial spin labeling MRI, using endogenous tracer (water), are sensitive and useful techniques for evaluating myocardial perfusion and angiogenesis. Recently, new strategies have been developed to quantify myocardial viability using T1-mapping and equilibrium contrast enhanced MR techniques because existing delayed contrast enhancement MRI (DE-MRI) sequences are limited in detecting patchy microinfarct and diffuse fibrosis. These new techniques were successfully used for characterizing diffuse myocardial fibrosis associated with myocarditis, amyloidosis, sarcoidosis heart failure, aortic hypertrophic cardiomyopathy, congenital heart disease, restrictive cardiomyopathy, arrhythmogenic right ventricular dysplasia and hypertension). Diffusion MRI provides information regarding microscopic tissue structure, while diffusion tensor imaging (DTI) helps to characterize the myocardium and monitor the process of LV remodeling after AMI. Novel trends in hybrid imaging, such as cardiac positron emission tomography (PET)/MRI and optical imaging/MRI, are recently under intensive investigation. With the promise of higher spatial

  19. Non-local means denoising of dynamic PET images.

    Directory of Open Access Journals (Sweden)

    Joyita Dutta

    Full Text Available Dynamic positron emission tomography (PET, which reveals information about both the spatial distribution and temporal kinetics of a radiotracer, enables quantitative interpretation of PET data. Model-based interpretation of dynamic PET images by means of parametric fitting, however, is often a challenging task due to high levels of noise, thus necessitating a denoising step. The objective of this paper is to develop and characterize a denoising framework for dynamic PET based on non-local means (NLM.NLM denoising computes weighted averages of voxel intensities assigning larger weights to voxels that are similar to a given voxel in terms of their local neighborhoods or patches. We introduce three key modifications to tailor the original NLM framework to dynamic PET. Firstly, we derive similarities from less noisy later time points in a typical PET acquisition to denoise the entire time series. Secondly, we use spatiotemporal patches for robust similarity computation. Finally, we use a spatially varying smoothing parameter based on a local variance approximation over each spatiotemporal patch.To assess the performance of our denoising technique, we performed a realistic simulation on a dynamic digital phantom based on the Digimouse atlas. For experimental validation, we denoised [Formula: see text] PET images from a mouse study and a hepatocellular carcinoma patient study. We compared the performance of NLM denoising with four other denoising approaches - Gaussian filtering, PCA, HYPR, and conventional NLM based on spatial patches.The simulation study revealed significant improvement in bias-variance performance achieved using our NLM technique relative to all the other methods. The experimental data analysis revealed that our technique leads to clear improvement in contrast-to-noise ratio in Patlak parametric images generated from denoised preclinical and clinical dynamic images, indicating its ability to preserve image contrast and high

  20. Accuracy of82Rb PET/CT Myocardial Perfusion Imaging with Regadenoson Stress, Including 3-Year Clinical Outcomes.

    Science.gov (United States)

    Brophey, Michael D; Farukhi, Irfan M; Castanon, Rosinda; DeLaPena, Rosinda; Bradshaw, Ledjona; Banerjee, Subhash

    2017-06-01

    The purpose of this study was to determine the clinical accuracy of 82 Rb PET/CT myocardial perfusion imaging (MPI) when performed with regadenoson stress in a U.S. Department of Veterans Affairs (VA) population of patients. Methods: The initial cohort of 480 patients undergoing vasodilator PET MPI with regadenoson stress at our institution from September 2009 through July 2010 was closely tracked for short-term outcomes based on correlation with invasive coronary catheterization. Long-term outcomes were determined by major adverse cardiac event rates based on data extraction from the electronic medical record and grouped by summed stress score (SSS) for a 3-y period. Results: At the 3-y follow-up, there had been 31 patient deaths, 5 of which were heart-related. Twenty-four patients had documented myocardial infarctions. Event rates and cardiac death rates were highly predicted by the results of PET MPI. Seventy patients underwent invasive cardiac catheterization within 60 d of the PET MPI. Patients were increasingly likely to undergo catheterization as their SSS increased. Catheterization correlation demonstrated a sensitivity of 95%, a positive predictive value of 88.4% for significant coronary artery disease, and an overall accuracy of 86% for PET MPI with regadenoson stress when compared with invasive catheterization. Conclusion: PET MPI with regadenoson stress demonstrates high accuracy when correlated with invasive catheterization and clinical outcomes. The SSS was highly predictive of cardiac events and patient survival in a VA population over a 3-y period of clinical follow-up. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  1. Impact of Point-Spread Function Modeling on PET Image Quality in Integrated PET/MR Hybrid Imaging.

    Science.gov (United States)

    Aklan, Bassim; Oehmigen, Mark; Beiderwellen, Karsten; Ruhlmann, Marcus; Paulus, Daniel H; Jakoby, Bjoern W; Ritt, Philipp; Quick, Harald H

    2016-01-01

    The aim of this study was to systematically assess the quantitative and qualitative impact of including point-spread function (PSF) modeling into the process of iterative PET image reconstruction in integrated PET/MR imaging. All measurements were performed on an integrated whole-body PET/MR system. Three substudies were performed: an (18)F-filled Jaszczak phantom was measured, and the impact of including PSF modeling in ordinary Poisson ordered-subset expectation maximization reconstruction on quantitative accuracy and image noise was evaluated for a range of radial phantom positions, iteration numbers, and postreconstruction smoothing settings; 5 representative datasets from a patient population (total n = 20, all oncologic (18)F-FDG PET/MR) were selected, and the impact of PSF on lesion activity concentration and image noise for various iteration numbers and postsmoothing settings was evaluated; and for all 20 patients, the influence of PSF modeling was investigated on visual image quality and number of detected lesions, both assessed by clinical experts. Additionally, the influence on objective metrics such as changes in SUVmean, SUVpeak, SUVmax, and lesion volume was assessed using the manufacturer-recommended reconstruction settings. In the phantom study, PSF modeling significantly improved activity recovery and reduced the image noise at all radial positions. This effect was measurable only at a high number of iterations (>10 iterations, 21 subsets). In the patient study, again, PSF increased the detected activity in the patient's lesions at concurrently reduced image noise. Contrary to the phantom results, the effect was notable already at a lower number of iterations (>1 iteration, 21 subsets). Lastly, for all 20 patients, when PSF and no-PSF reconstructions were compared, an identical number of congruent lesions was found. The overall image quality of the PSF reconstructions was rated better when compared with no-PSF data. The SUVs of the detected lesions

  2. Cardiac tumors: optimal cardiac MR sequences and spectrum of imaging appearances.

    LENUS (Irish Health Repository)

    O'Donnell, David H

    2012-02-01

    OBJECTIVE: This article reviews the optimal cardiac MRI sequences for and the spectrum of imaging appearances of cardiac tumors. CONCLUSION: Recent technologic advances in cardiac MRI have resulted in the rapid acquisition of images of the heart with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MRI provides optimal assessment of the location, functional characteristics, and soft-tissue features of cardiac tumors, allowing accurate differentiation of benign and malignant lesions.

  3. Optimization of image reconstruction conditions with phantoms for brain FDG and amyloid PET imaging

    National Research Council Canada - National Science Library

    Akamatsu, Go; Ikari, Yasuhiko; Nishio, Tomoyuki; Nishida, Hiroyuki; Ohnishi, Akihito; Aita, Kazuki; Sasaki, Masahiro; Sasaki, Masayuki; Senda, Michio

    2016-01-01

    The purpose of this study was to optimize image reconstruction conditions for brain 18F-FDG, 11C-PiB, 18F-florbetapir and 18F-flutemetamol PET imaging with Discovery-690 PET/CT for diagnosis and research on Alzheimer’s disease (AD...

  4. Cardiac Imaging in Patients With Ventricular Tachycardia.

    Science.gov (United States)

    Mahida, Saagar; Sacher, Frédéric; Dubois, Rémi; Sermesant, Maxime; Bogun, Frank; Haïssaguerre, Michel; Jaïs, Pierre; Cochet, Hubert

    2017-12-19

    Ventricular tachycardia (VT) is a major cause of sudden cardiac death. The majority of malignant VTs occur in patients with structural heart disease. Multimodality imaging techniques play an integral role in determining the underlying etiology and prognostic significance of VT. In recent years, advances in imaging technology have enabled characterization of the structural arrhythmogenic substrate in patients with VT with increasing precision. In parallel with these advances, the role of cardiac imaging has expanded from a largely diagnostic tool to an adjunctive tool to guide interventional approaches for treatment of VT. Invasive and noninvasive imaging techniques, often used in combination, have made it possible to integrate structural and electrophysiological information during VT ablation procedures. An important area of current development is the use of noninvasive imaging techniques based on body surface electrocardiographic mapping to elucidate the mechanisms of VT. In the future, these techniques may provide a priori information on mechanisms of VT in patients undergoing interventional procedures. This review provides an overview of the role of cardiac imaging in patients with VT. © 2017 American Heart Association, Inc.

  5. 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.

  6. PET imaging in ectopic Cushing syndrome: a systematic review.

    Science.gov (United States)

    Santhanam, Prasanna; Taieb, David; Giovanella, Luca; Treglia, Giorgio

    2015-11-01

    Cushing syndrome due to endogenous hypercortisolism may cause significant morbidity and mortality. The source of excess cortisol may be adrenal, pituitary, or ectopic. Ectopic Cushing syndrome is sometimes difficult to localize on conventional imaging like CT and MRI. After performing a multilevel thoracoabdominal imaging with CT, the evidence regarding the use of radiotracers for PET imaging is unclear due to significant molecular and etiological heterogeneity of potential causes of ectopic Cushing's syndrome. In our systematic review of literature, it appears that GalLium-based (Ga68) somatostatin receptor analogs have better sensitivity in diagnosis of bronchial carcinoids causing Cushing syndrome and FDG PET appears superior for small-cell lung cancers and other aggressive tumors. Further large-scale studies are needed to identify the best PET tracer for this condition.

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

    Science.gov (United States)

    Zhu, Xuping; España, Samuel; Daartz, Juliane; Liebsch, Norbert; Ouyang, Jinsong; Paganetti, Harald; Bortfeld, Thomas R.; El Fakhri, Georges

    2011-07-01

    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 soft-tissue regions were better retained with in-room short PET acquisitions because of the collection of 15O 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.

  8. Simultaneous maximum a posteriori longitudinal PET image reconstruction

    Science.gov (United States)

    Ellis, Sam; Reader, Andrew J.

    2017-09-01

    Positron emission tomography (PET) is frequently used to monitor functional changes that occur over extended time scales, for example in longitudinal oncology PET protocols that include routine clinical follow-up scans to assess the efficacy of a course of treatment. In these contexts PET datasets are currently reconstructed into images using single-dataset reconstruction methods. Inspired by recently proposed joint PET-MR reconstruction methods, we propose to reconstruct longitudinal datasets simultaneously by using a joint penalty term in order to exploit the high degree of similarity between longitudinal images. We achieved this by penalising voxel-wise differences between pairs of longitudinal PET images in a one-step-late maximum a posteriori (MAP) fashion, resulting in the MAP simultaneous longitudinal reconstruction (SLR) method. The proposed method reduced reconstruction errors and visually improved images relative to standard maximum likelihood expectation-maximisation (ML-EM) in simulated 2D longitudinal brain tumour scans. In reconstructions of split real 3D data with inserted simulated tumours, noise across images reconstructed with MAP-SLR was reduced to levels equivalent to doubling the number of detected counts when using ML-EM. Furthermore, quantification of tumour activities was largely preserved over a variety of longitudinal tumour changes, including changes in size and activity, with larger changes inducing larger biases relative to standard ML-EM reconstructions. Similar improvements were observed for a range of counts levels, demonstrating the robustness of the method when used with a single penalty strength. The results suggest that longitudinal regularisation is a simple but effective method of improving reconstructed PET images without using resolution degrading priors.

  9. Postmortem cardiac imaging in fetuses and children

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Andrew M. [Great Ormond Street Hospital for Children NHS Foundation Trust, Cardiorespiratory Division, Level 7, Old Nurses Home, London (United Kingdom); UCL Institute of Cardiovascular Science, London (United Kingdom); Arthurs, Owen J. [Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Radiology, London (United Kingdom); UCL Institute of Cardiovascular Science, London (United Kingdom); Sebire, Neil J. [UCL Institute of Cardiovascular Science, London (United Kingdom); Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Histopathology, London (United Kingdom)

    2015-04-01

    Fetal and pediatric cardiac autopsies have a crucial role in the counseling of parents with regard to both the cause of death of their child and the implications of such findings for future pregnancies, as well as for quality assurance of antenatal screening programs and antemortem diagnostic procedures. Postmortem imaging allows an opportunity to investigate the heart in situ prior to dissection, and both postmortem CT and postmortem MRI have shown excellent accuracy in detecting the majority of clinically significant cardiac lesions in the perinatal and pediatric population. As less-invasive autopsy becomes increasingly popular, clinical guidelines for maximal diagnostic yield in specific circumstances can be developed. (orig.)

  10. Clinical impact of 18F-FDG-PET/CT in the extra cardiac work-up of patients with infective endocarditis

    DEFF Research Database (Denmark)

    Asmar, Ali; Ozcan, Cengiz; Diederichsen, Axel C P

    2014-01-01

    OBJECTIVE: The purpose of this study was to assess the clinical importance of (18)F-FDG-PET/CT used in the extra cardiac work-up of patients with infective endocarditis (IE). BACKGROUND: IE is a serious condition with a significant mortality. Besides the degree of valvular involvement, the progno......OBJECTIVE: The purpose of this study was to assess the clinical importance of (18)F-FDG-PET/CT used in the extra cardiac work-up of patients with infective endocarditis (IE). BACKGROUND: IE is a serious condition with a significant mortality. Besides the degree of valvular involvement......, the prognosis relies crucially on the presence of systemic infectious embolism. METHODS: Seventy-two patients (71% males and mean age 63 ± 17 years) with IE were evaluated with (18)F-FDG-PET/CT in addition to standard work-up including patient history, physical examination, conventional imaging modalities...... lesions of clinical importance in one of seven IE patients and may be a substantial imaging technique for tracing peripheral infectious embolism due to IE. Thus, (18)F-FDG-PET/CT may help to guide adequate therapy and thereby improve the prognosis of patients with IE....

  11. Transforming a Targeted Porphyrin Theranostic Agent into a PET Imaging Probe for Cancer

    National Research Council Canada - National Science Library

    Shi, Jiyun; Liu, Tracy W B; Chen, Juan; Green, David; Jaffray, David; Wilson, Brian C; Wang, Fan; Zheng, Gang

    2011-01-01

    ...)Cu-PPF into a positron emission tomography (PET) probe for cancer imaging. Noninvasive PET imaging followed by radioassay evaluated the tumor accumulation, pharmacokinetics and biodistribution of (64)Cu-PPF. (64...

  12. Simultaneous Multiparametric PET/MRI with Silicon Photomultiplier PET and Ultra-High-Field MRI for Small-Animal Imaging.

    Science.gov (United States)

    Ko, Guen Bae; Yoon, Hyun Suk; Kim, Kyeong Yun; Lee, Min Sun; Yang, Bo Yeun; Jeong, Jae Min; Lee, Dong Soo; Song, In Chan; Kim, Seok-Ki; Kim, Daehong; Lee, Jae Sung

    2016-08-01

    Visualization of biologic processes at molecular and cellular levels has revolutionized the understanding and treatment of human diseases. However, no single biomedical imaging modality provides complete information, resulting in the emergence of multimodal approaches. Combining state-of-the-art PET and MRI technologies without loss of system performance and overall image quality can provide opportunities for new scientific and clinical innovations. Here, we present a multiparametric PET/MR imager based on a small-animal dedicated, high-performance, silicon photomultiplier (SiPM) PET system and a 7-T MR scanner. A SiPM-based PET insert that has the peak sensitivity of 3.4% and center volumetric resolution of 1.92/0.53 mm(3) (filtered backprojection/ordered-subset expectation maximization) was developed. The SiPM PET insert was placed between the mouse body transceiver coil and gradient coil of a 7-T small-animal MRI scanner for simultaneous PET/MRI. Mutual interference between the MRI and SiPM PET systems was evaluated using various MR pulse sequences. A cylindric corn oil phantom was scanned to assess the effects of the SiPM PET on the MR image acquisition. To assess the influence of MRI on the PET imaging functions, several PET performance indicators including scintillation pulse shape, flood image quality, energy spectrum, counting rate, and phantom image quality were evaluated with and without the application of MR pulse sequences. Simultaneous mouse PET/MRI studies were also performed to demonstrate the potential and usefulness of the multiparametric PET/MRI in preclinical applications. Excellent performance and stability of the PET system were demonstrated, and the PET/MRI combination did not result in significant image quality degradation of either modality. Finally, simultaneous PET/MRI studies in mice demonstrated the feasibility of the developed system for evaluating the biochemical and cellular changes in a brain tumor model and facilitating the

  13. 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

  14. Ligands for SPECT and PET imaging of muscarinic-cholinergic receptors of the heart and brain

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, F.F. Jr.; McPherson, D.W.; Luo, H. [and others

    1995-06-01

    Interest in the potential use of cerebral SPECT and PET imaging for determination of the density and activity of muscarinic-cholinergic receptors (mAChR) has been stimulated by the changes in these receptors which occur in many neurological diseases. In addition, the important involvement of mAChR in modulating negative inotropic cardiac activity suggests that such receptor ligands may have important applications in evaluation of changes which may occur in cardiac disease. In this paper, the properties of several key muscarinic receptor ligands being developed or which have been used for clinical SPECT and PET are discussed. In addition, the ORNL development of the new iodinated IQNP ligand based on QNB and the results of in vivo biodistribution studies in rats, in vitro competitive binding studies and ex vivo autoradiographic experiments are described. The use of radioiodinated IQNP may offer several advantages in comparison to IQNB because of its easy and high yield preparation and high brain uptake and the potential usefulness of the {open_quotes}partial{close_quotes} subtype selective IONP isomers. We also describe the development of new IQNP-type analogues which offer the opportunity for radiolabeling with positron-emitting radioisotopes (carbon-11, fluorine-18 and bromine-76) for potential use with PET.

  15. Pulmonary imaging using respiratory motion compensated simultaneous PET/MR.

    Science.gov (United States)

    Dutta, Joyita; Huang, Chuan; Li, Quanzheng; El Fakhri, Georges

    2015-07-01

    Pulmonary positron emission tomography (PET) imaging is confounded by blurring artifacts caused by respiratory motion. These artifacts degrade both image quality and quantitative accuracy. In this paper, the authors present a complete data acquisition and processing framework for respiratory motion compensated image reconstruction (MCIR) using simultaneous whole body PET/magnetic resonance (MR) and validate it through simulation and clinical patient studies. The authors have developed an MCIR framework based on maximum a posteriori or MAP estimation. For fast acquisition of high quality 4D MR images, the authors developed a novel Golden-angle RAdial Navigated Gradient Echo (GRANGE) pulse sequence and used it in conjunction with sparsity-enforcing k-t FOCUSS reconstruction. The authors use a 1D slice-projection navigator signal encapsulated within this pulse sequence along with a histogram-based gate assignment technique to retrospectively sort the MR and PET data into individual gates. The authors compute deformation fields for each gate via nonrigid registration. The deformation fields are incorporated into the PET data model as well as utilized for generating dynamic attenuation maps. The framework was validated using simulation studies on the 4D XCAT phantom and three clinical patient studies that were performed on the Biograph mMR, a simultaneous whole body PET/MR scanner. The authors compared MCIR (MC) results with ungated (UG) and one-gate (OG) reconstruction results. The XCAT study revealed contrast-to-noise ratio (CNR) improvements for MC relative to UG in the range of 21%-107% for 14 mm diameter lung lesions and 39%-120% for 10 mm diameter lung lesions. A strategy for regularization parameter selection was proposed, validated using XCAT simulations, and applied to the clinical studies. The authors' results show that the MC image yields 19%-190% increase in the CNR of high-intensity features of interest affected by respiratory motion relative to UG and a 6

  16. Quantitative carotid PET/MR imaging: clinical evaluation of MR-Attenuation correction versus CT-Attenuation correction in 18F-FDG PET/MR emission data and comparison to PET/CT

    OpenAIRE

    Bini, Jason; Robson, Philip M.; Calcagno, Claudia; Eldib, Mootaz; Fayad, Zahi A.

    2015-01-01

    Current PET/MR systems employ segmentation of MR images and subsequent assignment of empirical attenuation coefficients for quantitative PET reconstruction. In this study we examine the differences in the quantification of 18F-FDG uptake in the carotid arteries between PET/MR and PET/CT scanners. Five comparisons were performed to asses differences in PET quantification: i) PET/MR MR-based AC (MRAC) versus PET/MR CTAC, ii) PET/MR MRAC versus PET/CT, iii) PET/MR MRAC with carotid coil versus P...

  17. PET imaging in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Semah, F. [Service Hospitalier Frederic Joliot, DSV-CEA, 91 Orsay (France)

    2006-07-01

    The research projects on epilepsy addressed two main issues: the pathophysiology of the inter-ictal hypo-metabolism in temporal lobe epilepsy and the role of the basal ganglia in the control of seizure. Our research projects focused primarily on temporal lobe epilepsy: The pathophysiology of inter-ictal hypo-metabolism and its correlation with the epileptogenic network was investigated in patients with mesial temporal lobe epilepsy. Inter-ictal hypo-metabolism is commonly found in mesio-temporal lobe epilepsy (MTLE) but its pathophysiology remains incompletely understood. We hypothesized that metabolic changes reflect the preferential networks involved in ictal discharges. We analyzed the topography of inter-ictal hypo-metabolism according to electro-clinical patterns in 50 patients with unilateral hippocampal sclerosis (HS) and consistent features of MTLE. Based on electro-clinical correlations we identified 4 groups:1) mesial group characterized by mesial seizure onset without evidence of early spread beyond the temporal lobe; 2) anterior mesio-lateral group (AML) with early anterior spread, involving the anterior lateral temporal cortex and insulo-fronto-opercular areas; 3) widespread mesio-lateral group (WML) with widespread spread, involving both anterior and posterior lateral temporal and peri-sylvian areas; 4) bi-temporal group (BT) with early contralateral temporal spread. Results of FDG-PET imaging in each group were compared to control subjects using statistical parametric mapping software (SPM99). MRI data and surgical outcome in each group were compared to metabolic findings. Hypo-metabolism was limited to the hippocampal gyrus, the temporal pole and the insula in the mesial group. Gradual involvement of the lateral temporal cortex, the insula and the peri-sylvian areas was observed in the AML and WML groups. The BT group differed from the others by mild bi-temporal involvement, bilateral insular hypo-metabolism and longer epilepsy duration. MRI

  18. Acute myocarditis: multiparametric cardiac MR imaging.

    Science.gov (United States)

    Luetkens, Julian A; Doerner, Jonas; Thomas, Daniel K; Dabir, Darius; Gieseke, Juergen; Sprinkart, Alois M; Fimmers, Rolf; Stehning, Christian; Homsi, Rami; Schwab, Joerg O; Schild, Hans; Naehle, Claas P

    2014-11-01

    To evaluate the diagnostic value of cardiac magnetic resonance (MR) imaging at 3 T in patients suspected of having acute myocarditis by using a multiparametric cardiac MR imaging approach including T1 relaxation time as an additional tool for tissue characterization. Ethics commission approval was obtained for this prospective study, and written informed consent was obtained from all subjects. Twenty four patients with acute myocarditis (mean age ± standard deviation, 34.7 years ± 15.1; 75% men) and 42 control subjects (mean age, 38.7 years ± 10.2; 64% men) were included. Cardiac MR imaging approaches included relative T2 short tau inversion-recovery signal intensity ratio (T2 ratio), early gadolinium enhancement ratio, late gadolinium enhancement, native T1 relaxation times, and extracellular volume fraction. Receiver operating characteristic analysis was performed to compare diagnostic performance. The reference standard was the clinical evidence for acute myocarditis. Native T1 relaxation times were significantly longer in patients with acute myocarditis than in control subjects (1185.3 msec ± 49.3 vs 1089.1 msec ± 44.9, respectively; P T1 relaxation times (0.94) were higher compared with those of other cardiac MR parameters (late gadolinium enhancement, 0.90; T2 ratio, 0.79; extracellular volume fraction, 0.71; early gadolinium enhancement ratio, 0.63; P = .390, .018, .002, and T1 relaxation times (cutoff, 1140 msec) were equivalent compared with those of the established combined Lake Louise criteria (sensitivity, 92%; specificity, 80%; diagnostic accuracy, 85%). Diagnostic performance with native T1 mapping was superior to that with T2 ratio and early gadolinium enhancement ratio, and specificity was higher with native T1 mapping than that with Lake Louise criteria. This study underlines the potential of native T1 relaxation times to complement current cardiac MR approaches in patients suspected of having acute myocarditis.

  19. 18F-FDG PET-CT for Evaluation of Cardiac Angiosarcoma: A Case Report and Review of Literature

    Directory of Open Access Journals (Sweden)

    Varun Singh Dhull

    2015-02-01

    Full Text Available Cardiac angiosarcomas are rare neoplasms. We here present the case of a 24 year old male with a cardiac mass which was characterised as malignant on 18F-Fluorodeoxyglucose (18F-FDG positron emission tomography-computed tomography (PETCT. In addition 18F-FDG PET-CT also demonstrated pericardial infiltration and bone metastases. The tumor was confirmed to be angiosarcoma on biopsy and palliative chemotherapy was started. Here we have highlighted the potential role of 18F-FDG PET-CT in patients with cardiac angiosarcoma and presented a brief review

  20. 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...

  1. 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......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...... of anatomic, functional, and molecular imaging information. Positron emission tomography (PET)/computed tomography (CT) in oncology is emerging as an important imaging tool. The most common radiotracer for PET/CT in oncology, (18)F-fluorodeoxyglucose (FDG), is not very useful in the imaging of prostate cancer...

  2. Dynamic low dose I-123-iodophenylpentadecanoic acid metabolic cardiac imaging; Comparison to myocardial biopsy and reinjection SPECT thallium in ischemic cardiomyopathy and cardiac transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Murray, G.L.; Magill, H.L. [Baptist Memorial Hospital (United States); Schad, N.C.

    1993-12-01

    Recognition of stunned and hibernating myocardium is essential in this era of cardiac revascularization. Positron emission tomography (PET) accurately identifies viability but is costly and unavailable to most patients. Dynamic low dose I-123-iodophenylpentadecanoic acid (IPPA) metabolic cardiac imaging is a potentially cost-effective alternative to PET. Using transmural myocardial biopsies obtained during coronary bypass surgery as the viability gold standard, resting IPPA imaging agreed with 39/43 (91%) biopsies, with a sensitivity for viability of 33/36(92%) and a specificity of 6/7 (86%) in patients with severe ischemic cardiomyopathy. Eighty percent of IPPA viable, infarcted segments improved wall motion postoperatively. Furthermore, when compared to reinjection thallium (SPECT-Tl) scans after myocardial infarction, there was IPPA-Tl concordance in 27/35 (77%)(Kappa=0.536, p=0.0003). Similar to PET, IPPA demonstrated more viability than SPECT-Tl, 26/35 (74%) vs. 18/35 (51%)(p=0.047). Finally, when compared to transvenous endomyocardial biopsy for detecting rejection following cardiac transplantation, IPPA sensitivity for {>=}Grade II rejection was 100%, and IPPA screening assessment for the necessity of biopsy could result in a 31% cost-savings. Therefore, IPPA metabolic cardiac imaging is a safe, inexpensive technique with a promising future. (author).

  3. Magnetic resonance imaging for cardiac tumors

    Energy Technology Data Exchange (ETDEWEB)

    Niwa, Koichiro; Tashima, Kazuyuki; Okajima, Yoshitomo; Nakajima, Hiromichi; Terai, Masaru; Nakajima, Hironori; Harada, Tsutomu; Ishida, Yoshikazu.

    1988-09-01

    We performed magnetic resonance imaging (MRI) in 4 patients with cardiac tumor (1 with rhabdomyoma, 1 with left atrial myxoma, and 2 with tumor of the left ventricular wall) for morphological evaluation of the tumor. ECG-gated MRI was performed by the spin echo imaging technique using a superconducting MRI system operating at 0.5 tesla. Spatial extension of the tumor was clearly demonstrated in all the patients. Gadolinium-DTPA (Gd-DTPA), was used in the 2 patients with tumor of the left ventricular myocardium to enhance the contrast, and allowed clear visualization of the tumor. These findings show the usefulness of MRI and MRI with Gd-DTPA for morphological evaluation of cardiac tumor.

  4. Software-based PET-MR image coregistration: combined PET-MRI for the rest of us

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Matthew S.; Liu, Xinyang; Vyas, Pranav K.; Safdar, Nabile M. [Children' s National Health System, Sheikh Zayed Institute for Pediatric Surgical Innovation, Washington, DC (United States); Plishker, William; Zaki, George F. [IGI Technologies, Inc., College Park, MD (United States); Shekhar, Raj [Children' s National Health System, Sheikh Zayed Institute for Pediatric Surgical Innovation, Washington, DC (United States); IGI Technologies, Inc., College Park, MD (United States)

    2016-10-15

    With the introduction of hybrid positron emission tomography/magnetic resonance imaging (PET/MRI), a new imaging option to acquire multimodality images with complementary anatomical and functional information has become available. Compared with hybrid PET/computed tomography (CT), hybrid PET/MRI is capable of providing superior anatomical detail while removing the radiation exposure associated with CT. The early adoption of hybrid PET/MRI, however, has been limited. To provide a viable alternative to the hybrid PET/MRI hardware by validating a software-based solution for PET-MR image coregistration. A fully automated, graphics processing unit-accelerated 3-D deformable image registration technique was used to align PET (acquired as PET/CT) and MR image pairs of 17 patients (age range: 10 months-21 years, mean: 10 years) who underwent PET/CT and body MRI (chest, abdomen or pelvis), which were performed within a 28-day (mean: 10.5 days) interval. MRI data for most of these cases included single-station post-contrast axial T1-weighted images. Following registration, maximum standardized uptake value (SUV{sub max}) values observed in coregistered PET (cPET) and the original PET were compared for 82 volumes of interest. In addition, we calculated the target registration error as a measure of the quality of image coregistration, and evaluated the algorithm's performance in the context of interexpert variability. The coregistration execution time averaged 97±45 s. The overall relative SUV{sub max} difference was 7% between cPET-MRI and PET/CT. The average target registration error was 10.7±6.6 mm, which compared favorably with the typical voxel size (diagonal distance) of 8.0 mm (typical resolution: 0.66 mm x 0.66 mm x 8 mm) for MRI and 6.1 mm (typical resolution: 3.65 mm x 3.65 mm x 3.27 mm) for PET. The variability in landmark identification did not show statistically significant differences between the algorithm and a typical expert. We have presented a software

  5. 89Zr-bevacizumab PET imaging in primary breast cancer

    NARCIS (Netherlands)

    Gaykema, Sietske B M; Brouwers, Adrienne H; Lub-de Hooge, Marjolijn N; Pleijhuis, Rick G; Timmer-Bosscha, Hetty; Pot, Linda; van Dam, Gooitzen M; van der Meulen, Sibylle B; de Jong, Johan R; Bart, Joost; de Vries, Jakob; Jansen, Liesbeth; de Vries, Elisabeth G. E.; Schröder, Carolien P; de Vries, J

    UNLABELLED: Vascular endothelial growth factor (VEGF)-A is overexpressed in most malignant and premalignant breast lesions. VEGF-A can be visualized noninvasively with PET imaging and using the tracer (89)Zr-labeled bevacizumab. In this clinical feasibility study, we assessed whether VEGF-A in

  6. ClearPEM: prototype PET device dedicated to breast imaging

    CERN Document Server

    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. Zr-89- Bevacizumab PET Imaging in Primary Breast Cancer

    NARCIS (Netherlands)

    Gaykema, Sietske B. M.; Brouwers, Adrienne H.; Lub-de Hooge, Marjolijn N.; Pleijhuis, Rick G.; Timmer-Bosscha, Hetty; Pot, Linda; van Dam, Gooitzen M.; van der Meulen, Sibylle B.; de Jong, Johan R.; Bart, Joost; de Vries, Jakob; Jansen, Liesbeth; de Vries, Elisabeth G. E.; Schroder, Carolien P.

    2013-01-01

    Vascular endothelial growth factor (VEGF)-A is overexpressed in most malignant and premalignant breast lesions. VEGF-A can be visualized noninvasively with PET imaging and using the tracer Zr-89-labeled bevacizumab. In this clinical feasibility study, we assessed whether VEGF-A in primary breast

  8. PET imaging in the surgical management of pediatric brain tumors.

    Science.gov (United States)

    Pirotte, Benoit; Acerbi, Francesco; Lubansu, Alphonse; Goldman, Serge; Brotchi, Jacques; Levivier, Marc

    2007-07-01

    The present article illustrates whether positron-emission tomography (PET) imaging may improve the surgical management of pediatric brain tumors (PBT) at different steps. Among 400 consecutive PBT treated between 1995 and 2005 at Erasme Hospital, Brussels, Belgium, we have studied with (18) F-2-fluoro-2-deoxy-D-glucose (FDG)-PET and/or L-(methyl-(11)C)methionine (MET)-PET and integrated PET images in the diagnostic workup of 126 selected cases. The selection criteria were mainly based on the lesion appearance on magnetic resonance (MR) sequences. Cases were selected when MR imaging showed limitations for (1) assessing the evolving nature of an incidental lesion (n = 54), (2) selecting targets for contributive and accurate biopsy (n = 32), and (3) delineating tumor tissue for maximal resection (n = 40). Whenever needed, PET images were integrated in the planning of image-guided surgical procedures (frame-based stereotactic biopsies (SB), frameless navigation-based resections, or leksell gamma knife radiosurgery). Like in adults, PET imaging really helped the surgical management of the 126 children explored, which represented about 30% of all PBT, especially when the newly diagnosed brain lesion was (1) an incidental finding so that the choice between surgery and conservative MR follow-up was debated, and (2) so infiltrative or ill-defined on MR that the choice between biopsy and resection was hardly discussed. Integrating PET into the diagnostic workup of these two selected groups helped to (1) take a more appropriate decision in incidental lesions by detecting tumor/evolving tissue; (2) better understand complex cases by differentiating indolent and active components of the lesion; (3) improve target selection and diagnostic yield of stereotactic biopsies in gliomas; (4) illustrate the intratumoral histological heterogeneity in gliomas; (5) provide additional prognostic information; (6) reduce the number of trajectories in biopsies performed in eloquent areas such

  9. PET imaging of acute and chronic inflammation in living mice

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Qizhen; Cai, Weibo; Li, Zi-Bo; Chen, Kai; He, Lina; Chen, Xiaoyuan [Stanford University School of Medicine, The Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford, CA (United States); Li, Hui-Cheng; Hui, Mizhou [AmProtein Corporation, Camarillo, CA (United States)

    2007-11-15

    In this study, we evaluated the 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced acute and chronic inflammation in living mice by PET imaging of TNF-{alpha} and integrin {alpha}{sub v}{beta}{sub 3} expression. TPA was topically applied to the right ear of BALB/c mice every other day to create the inflammation model. {sup 64}Cu-DOTA-etanercept and {sup 64}Cu-DOTA-E{l_brace}E[c(RGDyK)]{sub 2}{r_brace}{sub 2} were used for PET imaging of TNF-{alpha} and integrin {alpha}{sub v}{beta}{sub 3} expression in both acute and chronic inflammation. Hematoxylin and eosin staining, ex vivo autoradiography, direct tissue sampling, and immunofluorescence staining were also performed to confirm the non-invasive PET imaging results. The ear thickness increased significantly and the TNF-{alpha} level more than tripled after a single TPA challenge. MicroPET imaging using {sup 64}Cu-DOTA-etanercept revealed high activity accumulation in the inflamed ear, reaching 11.1 {+-} 1.3, 13.0 {+-} 2.0, 10.9 {+-} 1.4, 10.2 {+-} 2.2%ID/g at 1, 4, 16, and 24 h post injection, respectively (n = 3). Repeated TPA challenges caused TPA-specific chronic inflammation and reduced {sup 64}Cu-DOTA-etanercept uptake due to lowered TNF-{alpha} expression. {sup 64}Cu-DOTA-E{l_brace}E[c(RGDyK)]{sub 2}{r_brace}{sub 2} uptake in the chronically inflamed ears (after four and eight TPA challenges) was significantly higher than in the control ears and those after one TPA challenge. Immunofluorescence staining revealed increased integrin {beta}{sub 3} expression, consistent with the non-invasive PET imaging results using {sup 64}Cu-DOTA-E{l_brace}E[c(RGDyK)]{sub 2}{r_brace}{sub 2} as an integrin {alpha}{sub v} {beta}{sub 3}-specific radiotracer. Biodistribution and autoradiography studies further confirmed the quantification capability of microPET imaging. Successful PET imaging of TNF- {alpha} expression in acute inflammation and integrin {alpha}{sub v} {beta}{sub 3} expression in chronic inflammation provides

  10. Comparison of MR-based attenuation correction vs. CT-based attenuation correction of Whole Body PET/MR imaging

    Science.gov (United States)

    Izquierdo-Garcia, David; Sawiak, Stephen J.; Knesaurek, Karin; Narula, Jagat; Fuster, Valentin; Machac, Joseph; Fayad, Zahi A.

    2014-01-01

    Purpose The objective of this paper was to evaluate the performance of the built-in MR-based attenuation correction method (MRAC) included in the combined whole-body Ingenuity TF PET/MR scanner and compare it to the gold standard CT-based attenuation correction (CTAC). Methods Twenty-six patients undergoing clinical whole body FDG-PET/CT imaging were subsequently scanned on the PET/MR (mean delay 100min). Patients were separated in two groups: alpha group (N=14) with no MR coils during PET/MR imaging and beta group (N=12) including MR coils (Neuro-Vascular, Spine, Cardiac or Torso coils). All images were coregistered to the same space (PET/MR). Voxel- and region-based (10 regions of interest, ROIs) comparisons were made between the 2 PET images from PET/MR: using MRAC and CTAC. Additional comparison of lesions performed by an experienced clinician was also reported. Results Body mass index (BMI) and lung density showed significant differences between alpha and beta groups. Right vs. left lung density was also significantly different within each group. Overall the beta group (with coils) presented higher MRAC PET values than the alpha group when compared to the CTAC (alpha: −0.2±33.6%, R2=0.98, p<0.001, beta: 10.31±69.86%, R2=0.97, p<0.001). Conclusion In comparison to CTAC, PET values with MRAC method were underestimated by less than 10% on average, although some ROIs and lesions do differ by more (such as spine, lung or heart). The beta group (with coils) showed increased overall PET quantification as well as increased variability when compared to the alpha group (no coils). PET reconstructed with MRAC showed some differences when compared to PET reconstructed with CTAC, mostly due to air pockets, metallic implants and attenuation differences in big bone areas (such as pelvis and spine) due to the segmentation limitation of the MRAC method. PMID:24652234

  11. 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...... in this field of small animal molecular imaging with special emphasis on the targets for tissue characterization in tumor biology such as hypoxia, proliferation and cancer specific over-expression of receptors. The added value of applying CT imaging for anatomical localization and tumor volume measurements...... is also described. In addition, the non-invasive nature of molecular imaging and the targets of these promising new tracers are attractive for other research areas as well, although these fields are much less explored. We present an example of an interesting research field with the application of small...

  12. NEMA image quality phantom measurements and attenuation correction in integrated PET/MR hybrid imaging

    OpenAIRE

    Ziegler, Susanne; Jakoby, Bjoern W.; Braun, Harald; Paulus, Daniel H.; Quick, Harald H.

    2015-01-01

    Background In integrated PET/MR hybrid imaging the evaluation of PET performance characteristics according to the NEMA standard NU 2?2007 is challenging because of incomplete MR-based attenuation correction (AC) for phantom imaging. In this study, a strategy for CT-based AC of the NEMA image quality (IQ) phantom is assessed. The method is systematically evaluated in NEMA IQ phantom measurements on an integrated PET/MR system. Methods NEMA IQ measurements were performed on the integrated 3.0 T...

  13. Nuclear cardiac imaging: Principles and applications

    Energy Technology Data Exchange (ETDEWEB)

    Iskandrian, A.S.

    1987-01-01

    This book is divided into 11 chapters. The first three provide a short description of the instrumentation, radiopharmaceuticals, and imaging techniques used in nuclear cardiology. Chapter 4 discusses exercise testing. Chapter 5 gives the theory, technical aspects, and interpretations of thallium-201 myocardial imaging and radionuclide ventriculography. The remaining chapters discuss the use of these techniques in patients with coronary artery disease, acute myocardial infarction, valvular heart disease, and other forms of cardiac disease. The author intended to emphasize the implications of nuclear cardiology procedures on patient care management and to provide a comprehensive bibliography.

  14. Imaging of Cardiac Valves by Computed Tomography

    OpenAIRE

    Gudrun Feuchtner

    2013-01-01

    This paper describes “how to” examine cardiac valves with computed tomography, the normal, diseased valves, and prosthetic valves. A review of current scientific literature is provided. Firstly, technical basics, “how to” perform and optimize a multislice CT scan and “how to” interpret valves on CT images are outlined. Then, diagnostic imaging of the entire spectrum of specific valvular disease by CT, including prosthetic heart valves, is highlighted. The last part gives a guide “how to” use ...

  15. Characterizing Tumors Using Metabolic Imaging: PET Imaging of Cellular Proliferation and Steroid Receptors

    Directory of Open Access Journals (Sweden)

    David A. Mankoff

    2000-01-01

    Full Text Available Treatment decisions in oncology are increasingly guided by information on the biologic characteristics of tumors. Currently, patient-specific information on tumor biology is obtained from the analysis of biopsy material. Positron emission tomography (PET provides quantitative estimates of regional biochemistry and receptor status and can overcome the sampling error and difficulty in performing serial studies inherent with biopsy. Imaging using the glucose metabolism tracer, 2-deoxy-2-fluoro-D-glucose (FDG, has demonstrated PET's ability to guide therapy in clinical oncology. In this review, we highlight PET approaches to imaging two other aspects of tumor biology: cellular proliferation and tumor steroid receptors. We review the biochemical and biologic processes underlying the imaging, positron-emitting radiopharmaceuticals that have been developed, quantitative image-analysis considerations, and clinical studies to date. This provides a basis for evaluating future developments in these promising applications of PET metabolic imaging.

  16. Dynamic comparison of PET imaging performance between state-of-the-art ToF-PET/CT and ToF-PET/MR scanners

    Energy Technology Data Exchange (ETDEWEB)

    Delso, Gaspar; Deller, Tim; Khalighi, Mehdi [GE Healthcare (Switzerland); Veit-Haibach, Patrick; Schulthess, Gustav von [University Hospital of Zurich (Switzerland)

    2014-07-29

    The goal of the present work was to determine the potential for dose reduction in a new clinical ToF-PET/MR scanner. This was achieved by means of long dynamic phantom acquisitions designed to provide a fair comparison of image quality and lesion detectability, as a function of activity, between the new PET/MR system and a state-of-the art PET/CT.

  17. Segmentation of Striatal Brain Structures from High Resolution PET Images

    Directory of Open Access Journals (Sweden)

    Ricardo J. P. C. Farinha

    2009-01-01

    Full Text Available We propose and evaluate an automatic segmentation method for extracting striatal brain structures (caudate, putamen, and ventral striatum from parametric C11-raclopride positron emission tomography (PET brain images. We focus on the images acquired using a novel brain dedicated high-resolution (HRRT PET scanner. The segmentation method first extracts the striatum using a deformable surface model and then divides the striatum into its substructures based on a graph partitioning algorithm. The weighted kernel k-means algorithm is used to partition the graph describing the voxel affinities within the striatum into the desired number of clusters. The method was experimentally validated with synthetic and real image data. The experiments showed that our method was able to automatically extract caudate, ventral striatum, and putamen from the images. Moreover, the putamen could be subdivided into anterior and posterior parts. An automatic method for the extraction of striatal structures from high-resolution PET images allows for inexpensive and reproducible extraction of the quantitative information from these images necessary in brain research and drug development.

  18. Reproducibility of Quantitative Brain Imaging Using a PET-Only and a Combined PET/MR System

    Directory of Open Access Journals (Sweden)

    Martin L. Lassen

    2017-07-01

    Full Text Available The purpose of this study was to test the feasibility of migrating a quantitative brain imaging protocol from a positron emission tomography (PET-only system to an integrated PET/MR system. Potential differences in both absolute radiotracer concentration as well as in the derived kinetic parameters as a function of PET system choice have been investigated. Five healthy volunteers underwent dynamic (R-[11C]verapamil imaging on the same day using a GE-Advance (PET-only and a Siemens Biograph mMR system (PET/MR. PET-emission data were reconstructed using a transmission-based attenuation correction (AC map (PET-only, whereas a standard MR-DIXON as well as a low-dose CT AC map was applied to PET/MR emission data. Kinetic modeling based on arterial blood sampling was performed using a 1-tissue-2-rate constant compartment model, yielding kinetic parameters (K1 and k2 and distribution volume (VT. Differences for parametric values obtained in the PET-only and the PET/MR systems were analyzed using a 2-way Analysis of Variance (ANOVA. Comparison of DIXON-based AC (PET/MR with emission data derived from the PET-only system revealed average inter-system differences of −33 ± 14% (p < 0.05 for the K1 parameter and −19 ± 9% (p < 0.05 for k2. Using a CT-based AC for PET/MR resulted in slightly lower systematic differences of −16 ± 18% for K1 and −9 ± 10% for k2. The average differences in VT were −18 ± 10% (p < 0.05 for DIXON- and −8 ± 13% for CT-based AC. Significant systematic differences were observed for kinetic parameters derived from emission data obtained from PET/MR and PET-only imaging due to different standard AC methods employed. Therefore, a transfer of imaging protocols from PET-only to PET/MR systems is not straightforward without application of proper correction methods.Clinical Trial Registration:www.clinicaltrialsregister.eu, identifier 2013-001724-19

  19. Image quality and radiation dose in cardiac imaging

    NARCIS (Netherlands)

    van Dijk, Joris David

    2016-01-01

    Coronary artery disease is a major cause of death accounting for 8% of all deaths in the Netherlands. This disease can be detected in an early stage by cardiac imaging. However, this detection comes at the price of a relatively high radiation dose which is potentially harmful for the patient.

  20. 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

  1. Value of C-11-methionine PET in imaging brain tumours and metastases

    NARCIS (Netherlands)

    Glaudemans, Andor W J M; Enting, Roeline; Heesters, Martinus; Dierckx, Rudi A J O; van Rheenen, Ronald W J; Walenkamp, Annemiek M E; Slart, Riemer H J A

    C-11-methionine (MET) is the most popular amino acid tracer used in PET imaging of brain tumours. Because of its characteristics, MET PET provides a high detection rate of brain tumours and good lesion delineation. This review focuses on the role of MET PET in imaging cerebral gliomas. The

  2. Radiolabeled Sugars Used for PET and SPECT Imaging.

    Science.gov (United States)

    Barrios-Lopez, Brianda; Bergstrom, Kim

    2016-01-01

    There are new efforts to develop "sugar" probes for molecular imaging focusing on human clinical studies. Radiolabeled carbohydrates are used as substrate probes for studying specific processes in tissues and organisms. The best application case is 2-Deoxy-2-[18F]fluoro-D-glucose (18F-FDG), which is incorporated by cancer cells. The introduction of ltF-FDG has advanced enormously human Positron Emission Tomography (PET). This review focuses on the importance of 18FFDG and other sugars as imaging probes in PET and Single Photon Emission Computed Tomography (SPECT) imaging. In conclusion, new radiolabeled molecules that can be used as radiopharmaceuticals also would possibly help in the treatment of cancer cells in human patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. 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.)

  4. 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.)

  5. Energy dependence of scatter components in multispectral PET imaging.

    Science.gov (United States)

    Bentourkia, M; Msaki, P; Cadorette, J; Lecomte, R

    1995-01-01

    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.

  6. NEMA image quality phantom measurements and attenuation correction in integrated PET/MR hybrid imaging.

    Science.gov (United States)

    Ziegler, Susanne; Jakoby, Bjoern W; Braun, Harald; Paulus, Daniel H; Quick, Harald H

    2015-12-01

    In integrated PET/MR hybrid imaging the evaluation of PET performance characteristics according to the NEMA standard NU 2-2007 is challenging because of incomplete MR-based attenuation correction (AC) for phantom imaging. In this study, a strategy for CT-based AC of the NEMA image quality (IQ) phantom is assessed. The method is systematically evaluated in NEMA IQ phantom measurements on an integrated PET/MR system. NEMA IQ measurements were performed on the integrated 3.0 Tesla PET/MR hybrid system (Biograph mMR, Siemens Healthcare). AC of the NEMA IQ phantom was realized by an MR-based and by a CT-based method. The suggested CT-based AC uses a template μ-map of the NEMA IQ phantom and a phantom holder for exact repositioning of the phantom on the systems patient table. The PET image quality parameters contrast recovery, background variability, and signal-to-noise ratio (SNR) were determined and compared for both phantom AC methods. Reconstruction parameters of an iterative 3D OP-OSEM reconstruction were optimized for highest lesion SNR in NEMA IQ phantom imaging. Using a CT-based NEMA IQ phantom μ-map on the PET/MR system is straightforward and allowed performing accurate NEMA IQ measurements on the hybrid system. MR-based AC was determined to be insufficient for PET quantification in the tested NEMA IQ phantom because only photon attenuation caused by the MR-visible phantom filling but not the phantom housing is considered. Using the suggested CT-based AC, the highest SNR in this phantom experiment for small lesions (PET/MR hybrid system. The superiority of CT-based AC for this phantom is demonstrated by comparison to measurements using MR-based AC. Furthermore, optimized PET image reconstruction parameters are provided for the highest lesion SNR in NEMA IQ phantom measurements.

  7. Toward simultaneous PET/MR breast imaging: systematic evaluation and integration of a radiofrequency breast coil.

    Science.gov (United States)

    Aklan, Bassim; Paulus, Daniel H; Wenkel, Evelyn; Braun, Harald; Navalpakkam, Bharath K; Ziegler, Susanne; Geppert, Christian; Sigmund, Eric E; Melsaether, Amy; Quick, Harald H

    2013-02-01

    With the recent introduction of integrated whole-body hybrid positron emission tomography/magnetic resonance (PET/MR) scanners, simultaneous PET/MR breast imaging appears to be a potentially attractive new clinical application. In this study, the technical groundwork toward performing simultaneous PET/MR breast imaging was developed and systematically evaluated in phantom experiments and breast cancer patient hybrid imaging. Measurements were performed on a state-of-the-art whole-body simultaneous PET/MR system (Biograph mMR, Siemens AG, Erlangen, Germany). The PET signal attenuating effects of a MR-only four-channel radiofrequency (RF) breast coil that is present in the PET field-of-view (FoV) during a simultaneous PET/MR data acquisition has been investigated and quantified. For this purpose, a dedicated PET/MR visible breast phantom featuring four modular inserts with various structures (no insert, MR insert, PET insert, and PET/MR insert) was developed. In addition to a systematic evaluation of MR-only image quality, the following phantom scans were performed using (18)F radio tracer: (1) PET emission scan with only the homogeneous breast phantom; (2) PET emission scan additionally with the RF breast coil in the PET FoV. Attenuation correction (AC) of PET data was performed with CT-based three-dimensional (3D) hardware attenuation maps (μ-maps) of the RF coil and breast phantom. Finally, a simultaneous PET/MR breast imaging was performed in two breast cancer patients. The modular breast phantom allowed for systematic evaluation of various MR, PET, and PET/MR image quality parameters. The RF breast coil provided MR images of good image quality, unaffected by PET imaging. The global attenuation of the RF breast coil on the PET emission data was approximately 11%. This hardware attributed PET signal attenuation was successfully corrected by using an appropriate CT-based 3D μ-map of the RF breast coil. Imaging of two breast cancer patients confirmed the

  8. A small animal PET based on GAPDs and charge signal transmission approach for hybrid PET-MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jihoon; Choi, Yong; Hong, Key Jo; Hu, Wei; Jung, Jin Ho; Huh, Yoonsuk [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Kim, Byung-Tae, E-mail: ychoi.image@gmail.com [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of)

    2011-08-15

    Positron emission tomography (PET) employing Geiger-mode avalanche photodiodes (GAPDs) and charge signal transmission approach was developed for small animal imaging. Animal PET contained 16 LYSO and GAPD detector modules that were arranged in a 70 mm diameter ring with an axial field of view of 13 mm. The GAPDs charge output signals were transmitted to a preamplifier located remotely using 300 cm flexible flat cables. The position decoder circuits (PDCs) were used to multiplex the PET signals from 256 to 4 channels. The outputs of the PDCs were digitized and further-processed in the data acquisition unit. The cross-compatibilities of the PET detectors and MRI were assessed outside and inside the MRI. Experimental studies of the developed full ring PET were performed to examine the spatial resolution and sensitivity. Phantom and mouse images were acquired to examine the imaging performance. The mean energy and time resolution of the PET detector were 17.6% and 1.5 ns, respectively. No obvious degradation on PET and MRI was observed during simultaneous PET-MRI data acquisition. The measured spatial resolution and sensitivity at the CFOV were 2.8 mm and 0.7%, respectively. In addition, a 3 mm diameter line source was clearly resolved in the hot-sphere phantom images. The reconstructed transaxial PET images of the mouse brain and tumor displaying the glucose metabolism patterns were imaged well. These results demonstrate GAPD and the charge signal transmission approach can allow the development of high performance small animal PET with improved MR compatibility.

  9. PET Imaging Stability Measurements During Simultaneous Pulsing of Aggressive MR Sequences on the SIGNA PET/MR System.

    Science.gov (United States)

    Deller, Timothy W; Khalighi, Mohammad Mehdi; Jansen, Floris P; Glover, Gary H

    2018-01-01

    The recent introduction of simultaneous whole-body PET/MR scanners has enabled new research taking advantage of the complementary information obtainable with PET and MRI. One such application is kinetic modeling, which requires high levels of PET quantitative stability. To accomplish the required PET stability levels, the PET subsystem must be sufficiently isolated from the effects of MR activity. Performance measurements have previously been published, demonstrating sufficient PET stability in the presence of MR pulsing for typical clinical use; however, PET stability during radiofrequency (RF)-intensive and gradient-intensive sequences has not previously been evaluated for a clinical whole-body scanner. In this work, PET stability of the GE SIGNA PET/MR was examined during simultaneous scanning of aggressive MR pulse sequences. Methods: PET performance tests were acquired with MR idle and during simultaneous MR pulsing. Recent system improvements mitigating RF interference and gain variation were used. A fast recovery fast spin echo MR sequence was selected for high RF power, and an echo planar imaging sequence was selected for its high heat-inducing gradients. Measurements were performed to determine PET stability under varying MR conditions using the following metrics: sensitivity, scatter fraction, contrast recovery, uniformity, count rate performance, and image quantitation. A final PET quantitative stability assessment for simultaneous PET scanning during functional MRI studies was performed with a spiral in-and-out gradient echo sequence. Results: Quantitation stability of a 68Ge flood phantom was demonstrated within 0.34%. Normalized sensitivity was stable during simultaneous scanning within 0.3%. Scatter fraction measured with a 68Ge line source in the scatter phantom was stable within the range of 40.4%-40.6%. Contrast recovery and uniformity were comparable for PET images acquired simultaneously with multiple MR conditions. Peak noise equivalent count

  10. PET/MR Imaging: New Frontier in Alzheimer's Disease and Other Dementias.

    Science.gov (United States)

    Zhang, Xin Y; Yang, Zhen L; Lu, Guang M; Yang, Gui F; Zhang, Long J

    2017-01-01

    Alzheimer's disease (AD) is the most common form of dementia; a progressive neurodegenerative disease that currently lacks an effective treatment option. Early and accurate diagnosis, in addition to quick elimination of differential diagnosis, allows us to provide timely treatments that delay the progression of AD. Imaging plays an important role for the early diagnosis of AD. The newly emerging PET/MR imaging strategies integrate the advantages of PET and MR to diagnose and monitor AD. This review introduces the development of PET/MR imaging systems, technical considerations of PET/MR imaging, special considerations of PET/MR in AD, and the system's potential clinical applications and future perspectives in AD.

  11. Positron Emission Tomography imaging with the SmartPET system

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-21

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

  12. Effect of glucose level on brain FDG-PET images

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Young; Lee, Yong Ki; Ahn, Sung Min [Dept. of Radiological Science, Gachon University, Seongnam (Korea, Republic of)

    2017-06-15

    In addition to tumors, normal tissues, such as the brain and myocardium can intake {sup 18}F-FDG, and the amount of {sup 18}F-FDG intake by normal tissues can be altered by the surrounding environment. Therefore, a process is necessary during which the contrasts of the tumor and normal tissues can be enhanced. Thus, this study examines the effects of glucose levels on FDG PET images of brain tissues, which features high glucose activity at all times, in small animals. Micro PET scan was performed on fourteen mice after injecting {sup 18}F-FDG. The images were compared in relation to fasting. The findings showed that the mean SUV value w as 0 .84 higher in fasted mice than in non-fasted mice. During observation, the images from non-fasted mice showed high accumulation in organs other than the brain with increased surrounding noise. In addition, compared to the non-fasted mice, the fasted mice showed higher early intake and curve increase. The findings of this study suggest that fasting is important in assessing brain functions in brain PET using {sup 18}F-FDG. Additional studies to investigate whether caffeine levels and other preprocessing items have an impact on the acquired images would contribute to reducing radiation exposure in patients.

  13. Hybrid PET/MR Imaging and Brain Connectivity.

    Science.gov (United States)

    Aiello, Marco; Cavaliere, Carlo; Salvatore, Marco

    2016-01-01

    In recent years, brain connectivity is gaining ever-increasing interest from the interdisciplinary research community. The study of brain connectivity is characterized by a multifaceted approach providing both structural and functional evidence of the relationship between cerebral regions at different scales. Although magnetic resonance (MR) is the most established imaging modality for investigating connectivity in vivo, the recent advent of hybrid positron emission tomography (PET)/MR scanners paved the way for more comprehensive investigation of brain organization and physiology. Due to the high sensitivity and biochemical specificity of radiotracers, combining MR with PET imaging may enrich our ability to investigate connectivity by introducing the concept of metabolic connectivity and cometomics and promoting new insights on the physiological and molecular bases underlying high-level neural organization. This review aims to describe and summarize the main methods of analysis of brain connectivity employed in MR imaging and nuclear medicine. Moreover, it will discuss practical aspects and state-of-the-art techniques for exploiting hybrid PET/MR imaging to investigate the relationship of physiological processes and brain connectivity.

  14. Hybrid PET/MR Imaging and Brain Connectivity

    Directory of Open Access Journals (Sweden)

    Marco eAiello

    2016-03-01

    Full Text Available In recent years, brain connectivity is gaining ever-increasing interest from the interdisciplinary research community. The study of brain connectivity is characterized by a multifaceted approach providing both structural and functional evidence of the relationship between cerebral regions at different scales. Although magnetic resonance (MR is the most established imaging modality for investigating connectivity in vivo, the recent advent of hybrid positron emission tomography (PET/MR scanners paved the way for more comprehensive investigation of brain organization and physiology. Due to the high sensitivity and biochemical specificity of radiotracers, combining MR with PET imaging may enrich our ability to investigate connectivity by introducing the concept of metabolic connectivity and cometomics and promoting new insights on the physiological and molecular bases underlying high-level neural organization. This review aims to describe and summarize the main methods of analysis of brain connectivity employed in MR imaging and nuclear medicine. Moreover, it will discuss practical aspects and state-of-the-art techniques for exploiting hybrid PET/MR imaging to investigate the relationship of physiological processes and brain connectivity.

  15. FDG PET Imaging of Extremities in Rheumatoid Arthritis.

    Science.gov (United States)

    Dhawan, Richa; Lokitz, Kyla; Lokitz, Stephen; Caldito, Gloria; Takalkar, Amol M

    2016-01-01

    The primary objective of this study was to evaluate the utility of fluorodeoxyglucose positive emission tomography imaging in assessing the degree of joint inflammation and response to therapy in patients with rheumatoid arthritis using standard PET parameters. Five subjects with newly diagnosed RA were enrolled in this IRB-approved prospective study. After standard conventional workup that included clinical and laboratory evaluation and disease activity score (DAS3v) calculation, subjects underwent baseline FDG PET scans of their hands and feet prior to initiation of treatment and after six months of standard treatment. The uptake of FDG in involved joints was assessed qualitatively (visual evaluation) as well as semi quantitatively using standardized uptake value (SUV). Findings from the FDG PET scans were correlated with clinical and laboratory parameters including DAS and ESR. In all five patients, increased FDG uptake was noted in various joints affected by RA. The intensity of uptake varied from mild to intense (SUVmax values from 3.10 to 6.0). Overall, these correlated well with the clinical evaluation of involved joints. FDG PET imaging provided additional information by showing involvement in joints that were difficult to evaluate clinically (e.g. mid foot joints). The PET data also provided a distribution of joint involvement with varying degrees of severity in the same subject. On objective analysis using Spearman rank correlation coefficient for statistical analysis, no significant correlations were observed (p>0.05) between DAS, ESR, and the different PET parameters at baseline (before treatment) despite large calculated positive correlation coefficients. This was due to the small sample size (n=5). At post-treatment, the significant correlations were those between DAS and Maximum metabolic disease burden (MDB max) (RS=0.9, p=0.04) and between ESR and MDB max (RS=0.9, p=0.04). The positive correlations between total metabolic disease burden (Total MDB

  16. 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.

  17. Novel axolotl cardiac function analysis method using magnetic resonance imaging

    NARCIS (Netherlands)

    Sanches, Pedro Gomes; Op 't Veld, Roel C.; de Graaf, Wolter; Strijkers, Gustav J.; Grüll, Holger

    2017-01-01

    The salamander axolotl is capable of complete regeneration of amputated heart tissue. However, non-invasive imaging tools for assessing its cardiac function were so far not employed. In this study, cardiac magnetic resonance imaging is introduced as a non-invasive technique to image heart function

  18. Integrated PET/MR.

    Science.gov (United States)

    Quick, Harald H

    2014-02-01

    Integrated whole-body PET/MR hybrid imaging combines excellent soft tissue contrast and various functional imaging parameters provided by MR with high sensitivity and quantification of radiotracer metabolism provided by positron emission tomography (PET). While clinical evaluation now is under way, integrated PET/MR demands for new technologies and innovative solutions, currently subject to interdisciplinary research. Attenuation correction of human soft tissues and of hardware components has to be MR-based to maintain quantification of PET imaging because computed tomography (CT) attenuation information is missing. This brings up the question of how to provide bone information with MR imaging. The limited field-of-view in MR imaging leads to truncations in body imaging and MR-based attenuation correction. Another research field is the implementation of motion correction technologies to correct for breathing and cardiac motion in view of the relatively long PET data acquisition times. Initial clinical applications of integrated PET/MR in oncology, neurology, pediatric oncology, and cardiovascular disease are highlighted. The hybrid imaging workflow here has to be tailored to the clinical indication to maximize diagnostic information while minimizing acquisition time. PET/MR introduces new artifacts that need special observation and innovative solutions for correction. Finally, the rising need for appropriate phantoms and standardization efforts in PET/MR hybrid imaging is discussed. Copyright © 2013 Wiley Periodicals, Inc.

  19. {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.)

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

    Science.gov (United States)

    Hansen, Adam E; Andersen, Flemming L; Henriksen, Sarah T; Vignaud, Alexandre; Ardenkjaer-Larsen, Jan H; Højgaard, Liselotte; Kjaer, Andreas; Klausen, Thomas L

    2016-12-01

    Integrated PET/MRI with hyperpolarized (13)C magnetic resonance spectroscopic imaging ((13)C-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 (13)C-MRSI and PET. Here, the feasibility of simultaneous PET and (13)C-MRSI as well as hyperpolarized (13)C-MRSI in an integrated whole-body PET/MRI hybrid scanner is evaluated using phantom experiments. Combined PET and (13)C-MRSI phantoms including a NEMA [(18)F]-FDG phantom, (13)C-acetate and (13)C-urea sources, and hyperpolarized (13)C-pyruvate were imaged repeatedly with PET and/or (13)C-MRSI. Measurements evaluated for interference effects included PET activity values in the largest sphere and a background region; total number of PET trues; and (13)C-MRSI signal-to-noise ratio (SNR) for urea and acetate phantoms. Differences between measurement conditions were evaluated using t tests. PET and (13)C-MRSI data acquisition could be performed simultaneously without any discernible artifacts. The average difference in PET activity between acquisitions with and without simultaneous (13)C-MRSI was 0.83 (largest sphere) and -0.76 % (background). The average difference in net trues was -0.01 %. The average difference in (13)C-MRSI SNR between acquisitions with and without simultaneous PET ranged from -2.28 to 1.21 % for all phantoms and measurement conditions. No differences were significant. The system was capable of (13)C-MRSI of hyperpolarized (13)C-pyruvate. Simultaneous PET and (13)C-MRSI in an integrated whole-body PET/MRI hybrid scanner is feasible. Phantom experiments showed that possible interference effects introduced by acquiring data from the two modalities simultaneously are small and non-significant. Further experiments can now investigate the benefits of simultaneous PET and

  1. Transthoracic Cardiac Acoustic Radiation Force Impulse Imaging

    Science.gov (United States)

    Bradway, David Pierson

    This dissertation investigates the feasibility of a real-time transthoracic Acoustic Radiation Force Impulse (ARFI) imaging system to measure myocardial function non-invasively in clinical setting. Heart failure is an important cardiovascular disease and contributes to the leading cause of death for developed countries. Patients exhibiting heart failure with a low left ventricular ejection fraction (LVEF) can often be identified by clinicians, but patients with preserved LVEF might be undetected if they do not exhibit other signs and symptoms of heart failure. These cases motivate development of transthoracic ARFI imaging to aid the early diagnosis of the structural and functional heart abnormalities leading to heart failure. M-Mode ARFI imaging utilizes ultrasonic radiation force to displace tissue several micrometers in the direction of wave propagation. Conventional ultrasound tracks the response of the tissue to the force. This measurement is repeated rapidly at a location through the cardiac cycle, measuring timing and relative changes in myocardial stiffness. ARFI imaging was previously shown capable of measuring myocardial properties and function via invasive open-chest and intracardiac approaches. The prototype imaging system described in this dissertation is capable of rapid acquisition, processing, and display of ARFI images and shear wave elasticity imaging (SWEI) movies. Also presented is a rigorous safety analysis, including finite element method (FEM) simulations of tissue heating, hydrophone intensity and mechanical index (MI) measurements, and thermocouple transducer face heating measurements. For the pulse sequences used in later animal and clinical studies, results from the safety analysis indicates that transthoracic ARFI imaging can be safely applied at rates and levels realizable on the prototype ARFI imaging system. Preliminary data are presented from in vivo trials studying changes in myocardial stiffness occurring under normal and abnormal

  2. CT, PET and MR-Imaging in experimental baromedical research

    DEFF Research Database (Denmark)

    Hansen, Kasper

    CBF), T and T * relaxation, and blood brain barrier (BBB) breakage 90 min following decompression. Results: Simulated diving induced significant changes in all measured parameters during 3 T MRI. SUV of F-FDG was unchanged in both groups, although following μCT-examination revealed intracranial bubbles...... it is intrinsically difficult to study humans or animals inside a pressure chamber. We have developed a preclinical pressure chamber system compatible with CT, PET and MR-imaging during pressurisation up to 1.013 mPa, which allows for anatomical visualisations and measurements of certain physiological processes......Pa pressurisation, and repeatedly after 500 kPa/min decompression. After MRI, venous bubble development was monitored using ultrasound. Second, preclinical μCT, PET/MRI, and high-field 9.4 T MR-Imaging systems evaluated changes in cerebral standard uptake value (SUV) of F-FDG, changes in cerebral blood flow (delta...

  3. Molecular Imaging of Hydrolytic Enzymes Using PET and SPECT.

    Science.gov (United States)

    Rempel, Brian P; Price, Eric W; Phenix, Christopher P

    2017-01-01

    Hydrolytic enzymes are a large class of biological catalysts that play a vital role in a plethora of critical biochemical processes required to maintain human health. However, the expression and/or activity of these important enzymes can change in many different diseases and therefore represent exciting targets for the development of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) radiotracers. This review focuses on recently reported radiolabeled substrates, reversible inhibitors, and irreversible inhibitors investigated as PET and SPECT tracers for imaging hydrolytic enzymes. By learning from the most successful examples of tracer development for hydrolytic enzymes, it appears that an early focus on careful enzyme kinetics and cell-based studies are key factors for identifying potentially useful new molecular imaging agents.

  4. Extracting cardiac myofiber orientations from high frequency ultrasound images

    Science.gov (United States)

    Qin, Xulei; Cong, Zhibin; Jiang, Rong; Shen, Ming; Wagner, Mary B.; Kirshbom, Paul; Fei, Baowei

    2013-03-01

    Cardiac myofiber plays an important role in stress mechanism during heart beating periods. The orientation of myofibers decides the effects of the stress distribution and the whole heart deformation. It is important to image and quantitatively extract these orientations for understanding the cardiac physiological and pathological mechanism and for diagnosis of chronic diseases. Ultrasound has been wildly used in cardiac diagnosis because of its ability of performing dynamic and noninvasive imaging and because of its low cost. An extraction method is proposed to automatically detect the cardiac myofiber orientations from high frequency ultrasound images. First, heart walls containing myofibers are imaged by B-mode high frequency (pig hearts.

  5. Cardiac Imaging Techniques for Physicians: Late Enhancement

    Science.gov (United States)

    Kellman, Peter; Arai, Andrew E.

    2012-01-01

    Late enhancement imaging is used to diagnose and characterize a wide range of ischemic and non-ischemic cardiomyopathies, and its use has become ubiquitous in the cardiac MR exam. As the use of late enhancement imaging has matured and the span of applications has widened, the demands on image quality have grown. The characterization of sub-endocardial MI now includes the accurate quantification of scar size, shape, and characterization of borders which have been shown to have prognostic significance. More diverse patterns of late enhancement including patchy, mid-wall, sub-epicardial, or diffuse enhancement are of interest in diagnosing non-ischemic cardiomyopathies. As clinicians are examining late enhancement images for more subtle indication of fibrosis, the demand for lower artifacts has increased. A range of new techniques have emerged to improve the speed and quality of late enhancement imaging including: methods for acquisition during free breathing, and fat water separated imaging for characterizing fibro-fatty infiltration and reduction of artifacts related to the presence of fat. Methods for quantification of T1 and extracellular volume fraction are emerging to tackle the issue of discriminating globally diffuse fibrosis from normal healthy tissue which is challenging using conventional late enhancement methods. The aim of this review will be to describe the current state of the art and to provide a guide to various clinical protocols that are commonly used. PMID:22903654

  6. A Novel Positron Emission Tomography (PET) Approach to Monitor Cardiac Metabolic Pathway Remodeling in Response to Sunitinib Malate.

    Science.gov (United States)

    O'Farrell, Alice C; Evans, Rhys; Silvola, Johanna M U; Miller, Ian S; Conroy, Emer; Hector, Suzanne; Cary, Maurice; Murray, David W; Jarzabek, Monika A; Maratha, Ashwini; Alamanou, Marina; Udupi, Girish Mallya; Shiels, Liam; Pallaud, Celine; Saraste, Antti; Liljenbäck, Heidi; Jauhiainen, Matti; Oikonen, Vesa; Ducret, Axel; Cutler, Paul; McAuliffe, Fionnuala M; Rousseau, Jacques A; Lecomte, Roger; Gascon, Suzanne; Arany, Zoltan; Ky, Bonnie; Force, Thomas; Knuuti, Juhani; Gallagher, William M; Roivainen, Anne; Byrne, Annette T

    2017-01-01

    Sunitinib is a tyrosine kinase inhibitor approved for the treatment of multiple solid tumors. However, cardiotoxicity is of increasing concern, with a need to develop rational mechanism driven approaches for the early detection of cardiac dysfunction. We sought to interrogate changes in cardiac energy substrate usage during sunitinib treatment, hypothesising that these changes could represent a strategy for the early detection of cardiotoxicity. Balb/CJ mice or Sprague-Dawley rats were treated orally for 4 weeks with 40 or 20 mg/kg/day sunitinib. Cardiac positron emission tomography (PET) was implemented to investigate alterations in myocardial glucose and oxidative metabolism. Following treatment, blood pressure increased, and left ventricular ejection fraction decreased. Cardiac [18F]-fluorodeoxyglucose (FDG)-PET revealed increased glucose uptake after 48 hours. [11C]Acetate-PET showed decreased myocardial perfusion following treatment. Electron microscopy revealed significant lipid accumulation in the myocardium. Proteomic analyses indicated that oxidative metabolism, fatty acid β-oxidation and mitochondrial dysfunction were among the top myocardial signalling pathways perturbed. Sunitinib treatment results in an increased reliance on glycolysis, increased myocardial lipid deposition and perturbed mitochondrial function, indicative of a fundamental energy crisis resulting in compromised myocardial energy metabolism and function. Our findings suggest that a cardiac PET strategy may represent a rational approach to non-invasively monitor metabolic pathway remodeling following sunitinib treatment.

  7. A Novel Positron Emission Tomography (PET Approach to Monitor Cardiac Metabolic Pathway Remodeling in Response to Sunitinib Malate.

    Directory of Open Access Journals (Sweden)

    Alice C O'Farrell

    Full Text Available Sunitinib is a tyrosine kinase inhibitor approved for the treatment of multiple solid tumors. However, cardiotoxicity is of increasing concern, with a need to develop rational mechanism driven approaches for the early detection of cardiac dysfunction. We sought to interrogate changes in cardiac energy substrate usage during sunitinib treatment, hypothesising that these changes could represent a strategy for the early detection of cardiotoxicity. Balb/CJ mice or Sprague-Dawley rats were treated orally for 4 weeks with 40 or 20 mg/kg/day sunitinib. Cardiac positron emission tomography (PET was implemented to investigate alterations in myocardial glucose and oxidative metabolism. Following treatment, blood pressure increased, and left ventricular ejection fraction decreased. Cardiac [18F]-fluorodeoxyglucose (FDG-PET revealed increased glucose uptake after 48 hours. [11C]Acetate-PET showed decreased myocardial perfusion following treatment. Electron microscopy revealed significant lipid accumulation in the myocardium. Proteomic analyses indicated that oxidative metabolism, fatty acid β-oxidation and mitochondrial dysfunction were among the top myocardial signalling pathways perturbed. Sunitinib treatment results in an increased reliance on glycolysis, increased myocardial lipid deposition and perturbed mitochondrial function, indicative of a fundamental energy crisis resulting in compromised myocardial energy metabolism and function. Our findings suggest that a cardiac PET strategy may represent a rational approach to non-invasively monitor metabolic pathway remodeling following sunitinib treatment.

  8. Simultaneous acquisition of magnetic resonance spectroscopy (MRS) data and positron emission tomography (PET) images with a prototype MR-compatible, small animal PET imager

    Energy Technology Data Exchange (ETDEWEB)

    Raylman, Raymond R; Majewski, Stan; Velan, S Sendhil; Lemieux, Susan; Kross, Brian; Popov, Vladimir; Smith, Mark F; Weisenberger, Andrew G

    2007-06-01

    Multi-modality imaging (such as PET-CT) 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 images created by MRI, allow the correlation of form with function. Perhaps more exciting than the combination of anatomical MRI with PET, is the melding of PET with MR spectroscopy (MRS). Thus, two aspects of physiology could be combined in novel ways to produce new insights into the physiology of normal and pathological processes. Our team is developing a system to acquire MRI images and MRS spectra, and PET images contemporaneously. The prototype MR-compatible PET system consists of two opposed detector heads (appropriate in size for small animal imaging), operating in coincidence mode with an active field-of-view of ∼14 cm in diameter. Each detector consists of an array of LSO detector elements coupled through a 2-m long fiber optic light guide to a single position-sensitive photomultiplier tube. The use of light guides allows these magnetic field-sensitive elements of the PET imager to be positioned outside the strong magnetic field of our 3T MRI scanner. The PET scanner imager was integrated with a 12-cm diameter, 12-leg custom, birdcage coil. Simultaneous MRS spectra and PET images were successfully acquired from a multi-modality phantom consisting of a sphere filled with 17 brain relevant substances and a positron-emitting radionuclide. There were no significant changes in MRI or PET scanner performance when both were present in the MRI magnet bore. This successful initial test demonstrates the potential for using such a multi-modality to obtain complementary MRS and PET data.

  9. Evaluation of PET Imaging Resolution Using 350 mu{m} Pixelated CZT as a VP-PET Insert Detector

    Science.gov (United States)

    Yin, Yongzhi; Chen, Ximeng; Li, Chongzheng; Wu, Heyu; Komarov, Sergey; Guo, Qingzhen; Krawczynski, Henric; Meng, Ling-Jian; Tai, Yuan-Chuan

    2014-02-01

    A cadmium-zinc-telluride (CZT) detector with 350 μm pitch pixels was studied in high-resolution positron emission tomography (PET) imaging applications. The PET imaging system was based on coincidence detection between a CZT detector and a lutetium oxyorthosilicate (LSO)-based Inveon PET detector in virtual-pinhole PET geometry. The LSO detector is a 20 ×20 array, with 1.6 mm pitches, and 10 mm thickness. The CZT detector uses ac 20 ×20 ×5 mm substrate, with 350 μm pitch pixelated anodes and a coplanar cathode. A NEMA NU4 Na-22 point source of 250 μm in diameter was imaged by this system. Experiments show that the image resolution of single-pixel photopeak events was 590 μm FWHM while the image resolution of double-pixel photopeak events was 640 μm FWHM. The inclusion of double-pixel full-energy events increased the sensitivity of the imaging system. To validate the imaging experiment, we conducted a Monte Carlo (MC) simulation for the same PET system in Geant4 Application for Emission Tomography. We defined LSO detectors as a scanner ring and 350 μm pixelated CZT detectors as an insert ring. GATE simulated coincidence data were sorted into an insert-scanner sinogram and reconstructed. The image resolution of MC-simulated data (which did not factor in positron range and acolinearity effect) was 460 μm at FWHM for single-pixel events. The image resolutions of experimental data, MC simulated data, and theoretical calculation are all close to 500 μm FWHM when the proposed 350 μm pixelated CZT detector is used as a PET insert. The interpolation algorithm for the charge sharing events was also investigated. The PET image that was reconstructed using the interpolation algorithm shows improved image resolution compared with the image resolution without interpolation algorithm.

  10. Early Recognition of Chronic Traumatic Encephalopathy through FDDNP PET Imaging

    Science.gov (United States)

    2016-10-01

    in those exposed to cumulative head trauma . 15. SUBJECT TERMS Traumatic Brain ury Positron Emission .<..IUlU’::!.!. "’. 16. SECURITY...brain template with gray mask applied. The results indicate a relationship between increased exposure to head trauma (measured by number of fights...boxers and non trauma exposed controls. ·Outcomes: To determine if PET FDDNP imaging may be a potential biomarker of and diagnostic tool for CTE

  11. Netupitant PET imaging and ADME studies in humans

    OpenAIRE

    Spinelli, Tulla; Calcagnile, Selma; Giuliano, Claudio; Rossi, Giorgia; Lanzarotti, Corinna; Mair, Stuart; Stevens, Lloyd; Nisbet, Ian

    2013-01-01

    Netupitant is a new, selective NK1 receptor antagonist under development for the prevention of chemotherapy-induced nausea and vomiting. Two studies were conducted to evaluate the brain receptor occupancy (RO) and disposition (ADME) of netupitant in humans. Positron emission tomography (PET) imaging with the NK1 receptor-binding?selective tracer [11C]-GR205171 was used to evaluate the brain penetration of different doses of netupitant (100, 300, and 450?mg) and to determine the NK1-RO duratio...

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

    OpenAIRE

    Dregely, Isabel; Lanz, Titus; Metz, Stephan; Mueller, Matthias F; Kuschan, Marika; Nimbalkar, Manoj; Ralph A. Bundschuh; Ziegler, Sibylle I; Haase, Axel; Nekolla, Stephan G.; Schwaiger, Markus

    2016-01-01

    OBJECTIVES: To implement and evaluate a dedicated receiver array coil for simultaneous positron emission tomography/magnetic resonance (PET/MR) imaging in breast cancer.METHODS: 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 (18) F-FDG...

  13. PET Imaging of Epigenetic Influences on Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Paul J. Couto

    2015-01-01

    Full Text Available The precise role of environment-gene interactions (epigenetics in the development and progression of Alzheimer’s disease (AD is unclear. This review focuses on the premise that radiotracer-specific PET imaging allows clinicians to visualize epigenetically influenced events and that such imaging may provide new, valuable insights for preventing, diagnosing, and treating AD. Current understanding of the role of epigenetics in AD and the principles underlying the use of PET radiotracers for in vivo diagnosis are reviewed. The relative efficacies of various PET radiotracers for visualizing the epigenetic influences on AD and their use for diagnosis are discussed. For example, [18F]FAHA demonstrates sites of differential HDAC activity, [18F]FDG indirectly illuminates sites of neuronal hypomethylation, and the carbon-11 isotope-containing Pittsburgh compound B ([11C]PiB images amyloid-beta plaque deposits. A definitive AD diagnosis is currently achievable only by postmortem histological observation of amyloid-beta plaques and tau neurofibrillary tangles. Therefore, reliable in vivo neuroimaging techniques could provide opportunities for early diagnosis and treatment of AD.

  14. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Imaging spectrum of sudden athlete cardiac death.

    LENUS (Irish Health Repository)

    Arrigan, M T

    2012-02-01

    Sudden athlete death (SAD) is a widely publicized and increasingly reported phenomenon. For many, the athlete population epitomize human physical endeavour and achievement and their unexpected death comes with a significant emotional impact on the public. Sudden deaths within this group are often without prior warning. Preceding symptoms of exertional syncope and chest pain do, however, occur and warrant investigation. Similarly, a positive family history of sudden death in a young person or a known family history of a condition associated with SAD necessitates further tests. Screening programmes aimed at detecting those at risk individuals also exist with the aim of reducing fatalities. In this paper we review the topic of SAD and discuss the epidemiology, aetiology, and clinical presentations. We then proceed to discuss each underlying cause, in turn discussing the pathophysiology of each condition. This is followed by a discussion of useful imaging methods with an emphasis on cardiac magnetic resonance and cardiac computed tomography and how these address the various issues raised by the pathophysiology of each entity. We conclude by proposing imaging algorithms for the investigation of patients considered at risk for these conditions and discuss the various issues raised in screening.

  16. Generalized PSF modeling for optimized quantitation in PET imaging

    Science.gov (United States)

    Ashrafinia, Saeed; Mohy-ud-Din, Hassan; Karakatsanis, Nicolas A.; Jha, Abhinav K.; Casey, Michael E.; Kadrmas, Dan J.; Rahmim, Arman

    2017-06-01

    Point-spread function (PSF) modeling offers the ability to account for resolution degrading phenomena within the PET image generation framework. PSF modeling improves resolution and enhances contrast, but at the same time significantly alters image noise properties and induces edge overshoot effect. Thus, studying the effect of PSF modeling on quantitation task performance can be very important. Frameworks explored in the past involved a dichotomy of PSF versus no-PSF modeling. By contrast, the present work focuses on quantitative performance evaluation of standard uptake value (SUV) PET images, while incorporating a wide spectrum of PSF models, including those that under- and over-estimate the true PSF, for the potential of enhanced quantitation of SUVs. The developed framework first analytically models the true PSF, considering a range of resolution degradation phenomena (including photon non-collinearity, inter-crystal penetration and scattering) as present in data acquisitions with modern commercial PET systems. In the context of oncologic liver FDG PET imaging, we generated 200 noisy datasets per image-set (with clinically realistic noise levels) using an XCAT anthropomorphic phantom with liver tumours of varying sizes. These were subsequently reconstructed using the OS-EM algorithm with varying PSF modelled kernels. We focused on quantitation of both SUVmean and SUVmax, including assessment of contrast recovery coefficients, as well as noise-bias characteristics (including both image roughness and coefficient of-variability), for different tumours/iterations/PSF kernels. It was observed that overestimated PSF yielded more accurate contrast recovery for a range of tumours, and typically improved quantitative performance. For a clinically reasonable number of iterations, edge enhancement due to PSF modeling (especially due to over-estimated PSF) was in fact seen to lower SUVmean bias in small tumours. Overall, the results indicate that exactly matched PSF

  17. Generalized PSF modeling for optimized quantitation in PET imaging.

    Science.gov (United States)

    Ashrafinia, Saeed; Mohy-Ud-Din, Hassan; Karakatsanis, Nicolas A; Jha, Abhinav K; Casey, Michael E; Kadrmas, Dan J; Rahmim, Arman

    2017-06-21

    Point-spread function (PSF) modeling offers the ability to account for resolution degrading phenomena within the PET image generation framework. PSF modeling improves resolution and enhances contrast, but at the same time significantly alters image noise properties and induces edge overshoot effect. Thus, studying the effect of PSF modeling on quantitation task performance can be very important. Frameworks explored in the past involved a dichotomy of PSF versus no-PSF modeling. By contrast, the present work focuses on quantitative performance evaluation of standard uptake value (SUV) PET images, while incorporating a wide spectrum of PSF models, including those that under- and over-estimate the true PSF, for the potential of enhanced quantitation of SUVs. The developed framework first analytically models the true PSF, considering a range of resolution degradation phenomena (including photon non-collinearity, inter-crystal penetration and scattering) as present in data acquisitions with modern commercial PET systems. In the context of oncologic liver FDG PET imaging, we generated 200 noisy datasets per image-set (with clinically realistic noise levels) using an XCAT anthropomorphic phantom with liver tumours of varying sizes. These were subsequently reconstructed using the OS-EM algorithm with varying PSF modelled kernels. We focused on quantitation of both SUVmean and SUVmax, including assessment of contrast recovery coefficients, as well as noise-bias characteristics (including both image roughness and coefficient of-variability), for different tumours/iterations/PSF kernels. It was observed that overestimated PSF yielded more accurate contrast recovery for a range of tumours, and typically improved quantitative performance. For a clinically reasonable number of iterations, edge enhancement due to PSF modeling (especially due to over-estimated PSF) was in fact seen to lower SUVmean bias in small tumours. Overall, the results indicate that exactly matched PSF

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

    Science.gov (United States)

    Dregely, Isabel; Lanz, Titus; Metz, Stephan; Mueller, Matthias F; Kuschan, Marika; Nimbalkar, Manoj; Bundschuh, Ralph A; Ziegler, Sibylle I; Haase, Axel; Nekolla, Stephan G; Schwaiger, Markus

    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 (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 (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. • State-of-the-art breast MRI using a dedicated PET/MR breast coil is feasible. • A multi-channel design facilitates shorter MR acquisition times via parallel imaging. • An MR coil inside a simultaneous PET/MR system causes PET photon attenuation. • Including a coil CT-template in PET image reconstruction results in recovering accurate quantification.

  19. Ultrasound image guidance of cardiac interventions

    Science.gov (United States)

    Peters, Terry M.; Pace, Danielle F.; Lang, Pencilla; Guiraudon, Gérard M.; Jones, Douglas L.; Linte, Cristian A.

    2011-03-01

    Surgical procedures often have the unfortunate side-effect of causing the patient significant trauma while accessing the target site. Indeed, in some cases the trauma inflicted on the patient during access to the target greatly exceeds that caused by performing the therapy. Heart disease has traditionally been treated surgically using open chest techniques with the patient being placed "on pump" - i.e. their circulation being maintained by a cardio-pulmonary bypass or "heart-lung" machine. Recently, techniques have been developed for performing minimally invasive interventions on the heart, obviating the formerly invasive procedures. These new approaches rely on pre-operative images, combined with real-time images acquired during the procedure. Our approach is to register intra-operative images to the patient, and use a navigation system that combines intra-operative ultrasound with virtual models of instrumentation that has been introduced into the chamber through the heart wall. This paper illustrates the problems associated with traditional ultrasound guidance, and reviews the state of the art in real-time 3D cardiac ultrasound technology. In addition, it discusses the implementation of an image-guided intervention platform that integrates real-time ultrasound with a virtual reality environment, bringing together the pre-operative anatomy derived from MRI or CT, representations of tracked instrumentation inside the heart chamber, and the intra-operatively acquired ultrasound images.

  20. Molecular imaging for prostate cancer: Performance analysis of (68)Ga-PSMA PET/CT versus choline PET/CT.

    Science.gov (United States)

    Michaud, L; Touijer, K A

    2017-06-01

    There is a need for a precise and reliable imaging to improve the management of prostate cancer. In recent years the PET/CT with choline has changed the handling of prostate cancer in Europe, and it is commonly used for initial stratification or for the diagnosis of a biochemical recurrence, although it does not lack limitations. Other markers are being tested, including the ligand of prostate-specific membrane antigen (PSMA), that seems to offer encouraging prospects. The goal of this piece of work was to critically review the role of choline and PSMA PET/CT in prostate cancer. A systematic literature review of databases PUBMED/MEDLINE and EMBASE was conducted searching for articles fully published in English on the PET marker in prostate cancer and its clinical application. It seems as 68Ga-PSMA PET/CT is better than PET/CT in prostate cancer to detect primary prostate lesions, initial metastases in the lymph nodes and recurrence. However, further research is required to obtain high-level tests. Also, other PET markers are studied. Moreover, the emergence of a new PET/MR camera could change the performance of PET imaging. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Simultaneous water activation and glucose metabolic rate imaging with PET.

    Science.gov (United States)

    Verhaeghe, Jeroen; Reader, Andrew J

    2013-02-07

    A novel imaging and signal separation strategy is proposed to be able to separate [(18)F]FDG and multiple [(15)O]H(2)O signals from a simultaneously acquired dynamic PET acquisition of the two tracers. The technique is based on the fact that the dynamics of the two tracers are very distinct. By adopting an appropriate bolus injection strategy and by defining tailored sets of basis functions that model either the FDG or water component, it is possible to separate the FDG and water signal. The basis functions are inspired from the spectral analysis description of dynamic PET studies and are defined as the convolution of estimated generating functions (GFs) with a set of decaying exponential functions. The GFs are estimated from the overall measured head curve, while the decaying exponential functions are pre-determined. In this work, the time activity curves (TACs) are modelled post-reconstruction but the model can be incorporated in a global 4D reconstruction strategy. Extensive PET simulation studies are performed considering single [(18)F]FDG and 6 [(15)O]H(2)O bolus injections for a total acquisition time of 75 min. The proposed method is evaluated at multiple noise levels and different parameters were estimated such as [(18)F]FDG uptake and blood flow estimated from the [(15)O]H(2)O component, requiring a full dynamic analysis of the two components, static images of [(18)F]FDG and the water components as well as [(15)O]H(2)O activation. It is shown that the resulting images and parametric values in ROIs are comparable to images obtained from separate imaging, illustrating the feasibility of simultaneous imaging of [(18)F]FDG and [(15)O]H(2)O components.

  2. 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.

  3. 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...

  4. 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...... for molecular imaging of cancer. Especially the possibility of a quick transfer of methods developed in animals to patients (translational research) is an important strength. This article will briefly discuss the newest applications and their importance and perspective in relation to the shift in paradigm...

  5. 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

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

    Science.gov (United States)

    Lois, Cristina; Bezrukov, Ilja; Schmidt, Holger; Schwenzer, Nina; Werner, Matthias K; Kupferschläger, Jürgen; Beyer, Thomas

    2012-11-01

    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 (oral) and Gadovist (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 (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 (IV) and a volunteer study employing two different oral MRCA (Lumirem and pineapple juice). MR-based attenuation maps were calculated following Dixon-based fat-water segmentation and an external atlas-based and pattern recognition (AT&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&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-based attenuation maps may be biased by oral iron

  7. Short-lived positron emitters in beam-on PET imaging during proton therapy

    NARCIS (Netherlands)

    Dendooven, P.; Buitenhuis, H. J. T.; Diblen, F.; Heeres, P. N.; Biegun, A. K.; Fiedler, F.; van Goethem, M-J; van der Graaf, E. R.; Brandenburg, Sijtze

    2015-01-01

    The only method for in vivo dose delivery verification in proton beam radiotherapy in clinical use today is positron emission tomography (PET) of the positron emitters produced in the patient during irradiation. PET imaging while the beam is on (so called beam-on PET) is an attractive option,

  8. The Risks of Inappropriateness in Cardiac Imaging

    Directory of Open Access Journals (Sweden)

    Eugenio Picano

    2009-05-01

    Full Text Available The immense clinical and scientific benefits of cardiovascular imaging are well-established, but are also true that 30 to 50% of all examinations are partially or totally inappropriate. Marketing messages, high patient demand and defensive medicine, lead to the vicious circle of the so-called Ulysses syndrome. Mr. Ulysses, a typical middle-aged “worried-well” asymptomatic subject with an A-type coronary personality, a heavy (opium smoker, leading a stressful life, would be advised to have a cardiological check-up after 10 years of war. After a long journey across imaging laboratories, he will have stress echo, myocardial perfusion scintigraphy, PET-CT, 64-slice CT, and adenosine-MRI performed, with a cumulative cost of >100 times a simple exercise-electrocardiography test and a cumulative radiation dose of >4,000 chest x-rays, with a cancer risk of 1 in 100. Ulysses is tired of useless examinations, exorbitant costs. unaffordable even by the richest society, and unacceptable risks.

  9. Dual tracer functional imaging of gastroenteropancreatic neuroendocrine tumors using 68Ga-DOTA-NOC PET-CT and 18F-FDG PET-CT: competitive or complimentary?

    Science.gov (United States)

    Naswa, Niraj; Sharma, Punit; Gupta, Santosh Kumar; Karunanithi, Sellam; Reddy, Rama Mohan; Patnecha, Manish; Lata, Sneh; Kumar, Rakesh; Malhotra, Arun; Bal, Chandrasekhar

    2014-01-01

    This study aimed to compare the diagnostic performance of Ga-DOTANOC PET/CT with F-FDG PET/CT in the patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Data of 51 patients with definite histological diagnosis of GEP-NET who underwent both Ga-DOTA-NOC PET-CT and F-FDG PET-CT within a span of 15 days were selected for this retrospective analysis. Sensitivity, specificity, and predictive values were calculated for Ga-DOTA-NOC PET-CT and F-FDG PET-CT, and results were compared both on patientwise and regionwise analysis. Ga-DOTA-NOC PET-CT is superior to F-FDG PET-CT on patientwise analysis (P NOC PET-CT is superior to F-FDG PET-CT only for lymph node metastases (P NOC PET-CT detected more liver and skeletal lesions compared with F-FDG PET-CT, the difference was not statistically significant. In addition, the results of combined imaging helped in selecting candidates who would undergo the appropriate mode of treatment, whether octreotide therapy or conventional chemotherapy Ga-DOTA-NOC PET-CT seems to be superior to F-FDG PET-CT for imaging GEP-NETs. However, their role seems to be complementary because combination of Ga-DOTA-NOC PET-CT and F-FDG PET-CT in such patients helps demonstrate the total disease burden and segregate them to proper therapeutic groups.

  10. Will PET amyloid imaging lead to overdiagnosis of Alzheimer dementia?

    Science.gov (United States)

    Dubroff, Jacob G; Nasrallah, Ilya M

    2015-08-01

    Alzheimer disease (AD), a progressive neurodegenerative disease that causes dementia, affects millions of elderly Americans and represents a growing problem with the aging of the population. There has been an increasing effort for improved and earlier diagnosis for AD. Several newly developed radiolabeled compounds targeting β-amyloid plaques, one of the major pathologic biomarkers of AD, have recently become available for clinical use. These radiopharmaceuticals allow for in vivo noninvasive visualization of abnormal β-amyloid deposits in the brain using positron emission tomography (PET). Amyloid PET imaging has demonstrated high sensitivity for pathologic cerebral amyloid deposition in multiple studies. Principal drawbacks to this new diagnostic test are declining specificity in older age groups and uncertain clinical role given lack of disease-modifying therapy for AD. Although there is strong evidence for the utility of amyloid PET in certain situations, detailed in a set of guidelines for appropriate use from the Alzheimer's Association and the Society of Nuclear Medicine and Molecular Imaging, the question of overdiagnosis, the diagnosis of a disease that would result in neither symptoms nor deaths, using this new medical tool needs to be carefully considered in light of efforts to secure reimbursement for the new technology that is already widely available for use as a clinical tool. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  11. Regenerative cell imaging in cardiac repair.

    Science.gov (United States)

    Moudgil, Rohit; Dick, Alexander J

    2014-11-01

    Heart disease continues to be a leading cause of death in the Western world. Although strides have been made in prevention and management of coronary artery disease, lost myocardium after an ischemic event remains at the core of the morbidity and the mortality. Poor regenerative capacity of the myocardium has led to the study of cell-based therapies to restore anatomical, functional, and viable myocardium. To that end, stem cells are undifferentiated cells that are self-renewing, clonogenic, and pluripotent and therefore ideal for the restorative job. However, to refine the technique of cell-based therapy, in vivo molecular assessment is imperative to monitor cell survival and their effect on myocardial restoration. Direct imaging of the behaviour of cells after implantation into living subjects can offer great insight into their mechanisms of action, and their therapeutic efficacy. In this article we explore current knowledge of various imaging modalities that have been used to assess in vivo cellular and molecular events after administration of stem cells in injured myocardium. The goal of the article is to provide a comprehensive overview of the literature, highlight various imaging modalities, and suggest some of the key concepts on the horizon in cardiac stem cell imaging. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  12. Cardiac stress MR imaging with dobutamine

    Energy Technology Data Exchange (ETDEWEB)

    Strach, K.; Meyer, C.; Schild, H.; Sommer, T. [University of Bonn, Department of Radiology, Bonn (Germany)

    2006-12-15

    Stress testing for detection of ischemia-induced wall-motion abnormalities has become a mainstay for noninvasive diagnosis and risk stratification of patients with suspected coronary artery disease (CAD). Recent technical developments in magnetic resonance imaging (MRI), including the adoption of balanced steady-state free precession (b-SSFP) sequences - preferentially in combination with parallel imaging techniques - have led to a significant reduction of imaging time and improved patient safety. The stress protocol includes application of high-dose dobutamine (up to 40 {mu}g/kg/min) combined with fractionated atropine (up to a maximal dose of 1.0 mg). High-dose dobutamine stress MRI revealed good sensitivity (83-96%) and specificity (80-100%) for detection of significant CAD. Myocardial tagging methods have been shown to further increase sensitivity for CAD detection. Severe complications (sustained tachycardia, ventricular fibrillation, myocardial infarction, cardiogenic shock) are rare but may be expected in 0.1-0.3% of patients. Dobutamine stress MRI has emerged as a reliable and safe clinical alternative for noninvasive assessment of CAD. New pulse sequences, such as real-time imaging, might obviate the need for breath holding and electrocardiogram (ECG) triggering in patients with severe dyspnoea and cardiac arrhythmias, which may further improve the clinical impact and acceptance of stress MRI in the future. (orig.)

  13. Erroneous cardiac ECG-gated PET list-mode trigger events can be retrospectively identified and replaced by an offline reprocessing approach: first results in rodents

    Science.gov (United States)

    Böning, Guido; Todica, Andrei; Vai, Alessandro; Lehner, Sebastian; Xiong, Guoming; Mille, Erik; Ilhan, Harun; la Fougère, Christian; Bartenstein, Peter; Hacker, Marcus

    2013-11-01

    The assessment of left ventricular function, wall motion and myocardial viability using electrocardiogram (ECG)-gated [18F]-FDG positron emission tomography (PET) is widely accepted in human and in preclinical small animal studies. The nonterminal and noninvasive approach permits repeated in vivo evaluations of the same animal, facilitating the assessment of temporal changes in disease or therapy response. Although well established, gated small animal PET studies can contain erroneous gating information, which may yield to blurred images and false estimation of functional parameters. In this work, we present quantitative and visual quality control (QC) methods to evaluate the accuracy of trigger events in PET list-mode and physiological data. Left ventricular functional analysis is performed to quantify the effect of gating errors on the end-systolic and end-diastolic volumes, and on the ejection fraction (EF). We aim to recover the cardiac functional parameters by the application of the commonly established heart rate filter approach using fixed ranges based on a standardized population. In addition, we propose a fully reprocessing approach which retrospectively replaces the gating information of the PET list-mode file with appropriate list-mode decoding and encoding software. The signal of a simultaneously acquired ECG is processed using standard MATLAB vector functions, which can be individually adapted to reliably detect the R-peaks. Finally, the new trigger events are inserted into the PET list-mode file. A population of 30 mice with various health statuses was analyzed and standard cardiac parameters such as mean heart rate (119 ms ± 11.8 ms) and mean heart rate variability (1.7 ms ± 3.4 ms) derived. These standard parameter ranges were taken into account in the QC methods to select a group of nine optimal gated and a group of eight sub-optimal gated [18F]-FDG PET scans of mice from our archive. From the list-mode files of the optimal gated group, we

  14. Monte Carlo simulation of PET and SPECT imaging of {sup 90}Y

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Akihiko, E-mail: takahsr@hs.med.kyushu-u.ac.jp; Sasaki, Masayuki [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Himuro, Kazuhiko; Yamashita, Yasuo; Komiya, Isao [Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Baba, Shingo [Department of Clinical Radiology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

    2015-04-15

    Purpose: Yittrium-90 ({sup 90}Y) is traditionally thought of as a pure beta emitter, and is used in targeted radionuclide therapy, with imaging performed using bremsstrahlung single-photon emission computed tomography (SPECT). However, because {sup 90}Y also emits positrons through internal pair production with a very small branching ratio, positron emission tomography (PET) imaging is also available. Because of the insufficient image quality of {sup 90}Y bremsstrahlung SPECT, PET imaging has been suggested as an alternative. In this paper, the authors present the Monte Carlo-based simulation–reconstruction framework for {sup 90}Y to comprehensively analyze the PET and SPECT imaging techniques and to quantitatively consider the disadvantages associated with them. Methods: Our PET and SPECT simulation modules were developed using Monte Carlo simulation of Electrons and Photons (MCEP), developed by Dr. S. Uehara. PET code (MCEP-PET) generates a sinogram, and reconstructs the tomography image using a time-of-flight ordered subset expectation maximization (TOF-OSEM) algorithm with attenuation compensation. To evaluate MCEP-PET, simulated results of {sup 18}F PET imaging were compared with the experimental results. The results confirmed that MCEP-PET can simulate the experimental results very well. The SPECT code (MCEP-SPECT) models the collimator and NaI detector system, and generates the projection images and projection data. To save the computational time, the authors adopt the prerecorded {sup 90}Y bremsstrahlung photon data calculated by MCEP. The projection data are also reconstructed using the OSEM algorithm. The authors simulated PET and SPECT images of a water phantom containing six hot spheres filled with different concentrations of {sup 90}Y without background activity. The amount of activity was 163 MBq, with an acquisition time of 40 min. Results: The simulated {sup 90}Y-PET image accurately simulated the experimental results. PET image is visually

  15. 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.)

  16. Cardiac imaging in patients with chronic liver disease

    DEFF Research Database (Denmark)

    Wiese, Signe; Hove, Jens D; Møller, Søren

    2017-01-01

    to be involved in the development of hepatic nephropathy and is associated with an impaired survival. In the field of cardiac imaging, CCM is not yet a well-characterized entity, hence various modalities of cardiac imaging have been applied. Stress testing with either physiologically or pharmacologically induced...

  17. Partial volume correction of whole body PET images using the wavelet transform

    Science.gov (United States)

    Spinelli, Antonello E.; Guerrieri, Luca; D'Ambrosio, Daniela; Franchi, Roberto; Boschi, Stefano; Marengo, Mario

    2008-04-01

    A general approach for partial volume correction of positron emission tomography (PET) images is introduced. The method is based on the merging of functional information from PET images and anatomical information using high resolution anatomical images. In order to decompose the PET and high resolution images the "á trous" algorithm was implemented. Results obtained with simulated and real patients images show a significant partial volume reduction and image enhancement. The relative errors in the partial volume corrected image are always less than 3,6% with respect to 16% of the original image.

  18. Amyloid PET Imaging in Lewy body disorders.

    Science.gov (United States)

    Donaghy, Paul; Thomas, Alan J; O'Brien, John T

    2015-01-01

    Lewy body (LB) disorders, including Parkinson disease (PD), Parkinson disease dementia (PDD), and dementia with Lewy bodies (DLB), are the second most common type of neurodegenerative dementia. Although the pathological hallmarks of LB disorders are Lewy bodies and Lewy neurites, cortical amyloid-beta (Aβ) deposition is also often seen. The relationship between Aβ pathology and dementia in LB disorders is unclear. Recently, positron emission tomography Aβ ligands have been developed that enable in vivo imaging of Aβ. In this paper we review amyloid imaging studies in LB disorders. LB disorders are associated with lower mean cortical Aβ ligand binding compared with Alzheimer disease. In DLB and PDD many subjects have normal levels of cortical Aβ, though a subset show increased Aβ ligand binding. Those with DLB show greater ligand binding than PDD; binding does not appear to be increased in PD without dementia. Cortical Aβ deposition may be a factor in the development of cognitive impairment in some cases of dementia in LB disorders. Amyloid imaging is of limited use in the diagnosis of LB disorders but Aβ deposition may predict the future development of dementia in PD. Reports of correlation between Aβ deposition and symptom profile, severity, and progression have been inconsistent. Some results suggest a synergistic interaction between Aβ and α-synuclein. Interpretation of the current evidence is hampered by differing methodologies across studies and small sample sizes. Large, prospective longitudinal studies are needed to clarify the association of Aβ with symptom development, progression, severity, and treatment response in LB disorders. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  19. Deep Learning MR Imaging-based Attenuation Correction for PET/MR Imaging.

    Science.gov (United States)

    Liu, Fang; Jang, Hyungseok; Kijowski, Richard; Bradshaw, Tyler; McMillan, Alan B

    2018-02-01

    Purpose To develop and evaluate the feasibility of deep learning approaches for magnetic resonance (MR) imaging-based attenuation correction (AC) (termed deep MRAC) in brain positron emission tomography (PET)/MR imaging. Materials and Methods A PET/MR imaging AC pipeline was built by using a deep learning approach to generate pseudo computed tomographic (CT) scans from MR images. A deep convolutional auto-encoder network was trained to identify air, bone, and soft tissue in volumetric head MR images coregistered to CT data for training. A set of 30 retrospective three-dimensional T1-weighted head images was used to train the model, which was then evaluated in 10 patients by comparing the generated pseudo CT scan to an acquired CT scan. A prospective study was carried out for utilizing simultaneous PET/MR imaging for five subjects by using the proposed approach. Analysis of covariance and paired-sample t tests were used for statistical analysis to compare PET reconstruction error with deep MRAC and two existing MR imaging-based AC approaches with CT-based AC. Results Deep MRAC provides an accurate pseudo CT scan with a mean Dice coefficient of 0.971 ± 0.005 for air, 0.936 ± 0.011 for soft tissue, and 0.803 ± 0.021 for bone. Furthermore, deep MRAC provides good PET results, with average errors of less than 1% in most brain regions. Significantly lower PET reconstruction errors were realized with deep MRAC (-0.7% ± 1.1) compared with Dixon-based soft-tissue and air segmentation (-5.8% ± 3.1) and anatomic CT-based template registration (-4.8% ± 2.2). Conclusion The authors developed an automated approach that allows generation of discrete-valued pseudo CT scans (soft tissue, bone, and air) from a single high-spatial-resolution diagnostic-quality three-dimensional MR image and evaluated it in brain PET/MR imaging. This deep learning approach for MR imaging-based AC provided reduced PET reconstruction error relative to a CT-based standard within the brain compared

  20. Functional cardiac imaging by random access microscopy

    Directory of Open Access Journals (Sweden)

    Claudia eCrocini

    2014-10-01

    Full Text Available Advances in the development of voltage sensitive dyes and Ca2+ sensors in combination with innovative microscopy techniques allowed researchers to perform functional measurements with an unprecedented spatial and temporal resolution. At the moment, one of the shortcomings of available technologies is their incapability of imaging multiple fast phenomena while controlling the biological determinants involved. In the near future, ultrafast deflectors can be used to rapidly scan laser beams across the sample, performing optical measurements of action potential and Ca2+ release from multiple sites within cardiac cells and tissues. The same scanning modality could also be used to control local Ca2+ release and membrane electrical activity by activation of caged compounds and light-gated ion channels. With this approach, local Ca2+ or voltage perturbations could be induced, simulating arrhythmogenic events, and their impact on physiological cell activity could be explored. The development of this optical methodology will provide fundamental insights in cardiac disease, boosting new therapeutic strategies, and, more generally, it will represent a new approach for the investigation of the physiology of excitable cells.

  1. 90Y PET/CT quantitative accuracy and image quality

    Directory of Open Access Journals (Sweden)

    Wendy Siman

    2014-03-01

    Full Text Available Purpose: To optimize 90Y-PET/CT image reconstruction for quantitative accuracy and optimal image quality.Methods: PET/CT scans of a NEMA IEC phantom (3GBq 90YCl2, sphere uptake ratio of ~7 were acquired on 4 GE (BGO:DSTE, DST & LYSO:DRX, D690 and 1 Siemens (LSO:mCT scanners in 3D list mode with 30 min/bed; replayed to 20, 15, 10 min/bed. Iterative reconstruction parameters explored were SUB × IT (3 – 80 and post-reconstruction filters: transaxial: 5 – 25 mm cutoff & z-axis (GE only: std vs. heavy. The effects of PSF modeling and TOF correction were evaluated for D690 and mCT. VOIs were drawn inside spheres and in adjacent background regions. The accuracy of sphere activity concentration (AC in kBq/mL and contrast to noise ratio (CNR was calculated as function of SUB × IT. Reconstructed PET images were also evaluated qualitatively for sphere detectability and artifacts.Results: AC converged to 70 – 90% accuracy for 37 mm sphere and further degraded for smaller spheres. Spheres at max CNR might not reach AC convergence yet. Smaller spheres have slower convergence but reach CNR max together with other spheres. Scan duration did not strongly affect sphere convergence but shorter scans increased noise and reduced detectability; 13 mm spheres were not visible going from 30 to 15 min/bed. Heavy z-axis (GE and transaxial filter with 10 – 15 mm cutoff helped suppress noise and increase sphere detectability at the expense of accuracy. Images with PSF+TOF corrections had higher sphere detectability and converged faster. Hot cluster artifacts 5 – 7 times the background were seen in some cases with SUB × IT near convergence and lower filtration.Conclusion: Accurate 90Y AC was not achieved even at convergence and noise is a major concern. 90YPET/CT reconstruction parameters are different than those for 18F and benefit substantially from PSF+TOF corrections. Optimum image quality and accurate AC may not be simultaneously achievable

  2. 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.

  3. Role of {sup 18}F-FDG PET/CT in the diagnosis of infective endocarditis in patients with an implanted cardiac device: a prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Graziosi, Maddalena; Lorenzini, Massimiliano; Diemberger, Igor; Pasquale, Ferdinando; Ziacchi, Matteo; Biffi, Mauro; Martignani, Cristian; Boriani, Giuseppe; Rapezzi, Claudio [Alma Mater-University of Bologna, and S. Orsola-Malpighi Hospital, Cardiology Unit, Department of Experimental, Diagnostic and Specialty Medicine, Bologna (Italy); Nanni, Cristina; Bonfiglioli, Rachele; Fanti, Stefano [Alma Mater-University of Bologna, and S. Orsola-Malpighi Hospital, Nuclear Medicine Unit, Department of Experimental, Diagnostic and Specialty Medicine, Bologna (Italy); Bartoletti, Michele; Tumietto, Fabio; Viale, Pier Luigi [Alma Mater-University of Bologna, and S. Orsola-Malpighi Hospital, Infectious Diseases Unit, Department of Medical and Surgical Sciences, Bologna (Italy)

    2014-08-15

    Infective endocarditis (IE) is widely underdiagnosed or diagnosed after a major delay. The diagnosis is currently based on the modified DUKE criteria, where the only validated imaging technique is echocardiography, and remains challenging especially in patients with an implantable cardiac device. The aim of this study was to assess the incremental diagnostic role of {sup 18}F-FDG PET/CT in patients with an implanted cardiac device and suspected IE. We prospectively analysed 27 consecutive patients with an implantable device evaluated for suspected device-related IE between January 2011 and June 2013. The diagnostic probability of IE was defined at presentation according to the modified DUKE criteria. PET/CT was performed as soon as possible following the clinical suspicion of IE. Patients then underwent medical or surgical treatment based on the overall clinical evaluation. During follow-up, we considered: lead cultures in patients who underwent extraction, direct inspection and lead cultures in those who underwent surgery, and a clinical/instrumental reevaluation after at least 6 months in patients who received antimicrobial treatment or had an alternative diagnosis and were not treated for IE. After the follow-up period, the diagnosis was systematically reviewed by the multidisciplinary team using the modified DUKE criteria and considering the new findings. Among the ten patients with a positive PET/CT scan, seven received a final diagnosis of ''definite IE'', one of ''possible IE'' and two of ''IE rejected''. Among the 17 patients with a negative PET/CT scan, four were false-negative and received a final diagnosis of definite IE. These patients underwent PET/CT after having started antibiotic therapy (≥48 h) or had a technically suboptimal examination. In patients with a cardiac device, PET/CT increases the diagnostic accuracy of the modified Duke criteria for IE, particularly in the subset of

  4. PET/MR Versus PET/CT Imaging: Impact on the Clinical Management of Small-Bowel Crohn's Disease.

    Science.gov (United States)

    Pellino, Gianluca; Nicolai, Emanuele; Catalano, Onofrio A; Campione, Severo; D'Armiento, Francesco P; Salvatore, Marco; Cuocolo, Alberto; Selvaggi, Francesco

    2016-03-01

    The aim of this study was to compare the accuracy and clinical impact of hybrid positron emission tomography [PET]/magnetic resonance-enterography [MR-E] and PET/computed tomography-enterography [CT-E] in patients with Crohn's disease [CD]. A total of 35 patients with symptomatic small-bowel CD who were scheduled to undergo operation were evaluated before operation by same-day PET/CT-E and PET/MR-E. PET/MR-E was also compared with MR-E alone. Imaging accuracy for detecting pathological sites and discriminating between fibrotic and inflammatory strictures was assessed. Treatment was adjusted according to imaging findings and change in medical/surgical strategy was also evaluated. PET/CT-E, PET/MR-E, and MR-E were equally accurate in detecting CD sites. PET/MR-E was more accurate in assessing extra-luminal disease [p = 0.002], which was associated with higher need for stoma [p = 0.022] and distant localisation [p = 0.002]. When the latter was observed, laparoscopy was started with hand-assisted device, reducing operative time [p = 0.022]. PET/MR-E was also more accurate in detecting a fibrotic component compared with PET/CT-E [p = 0.043] and with MR-E [p = 0.024]. Fibrosis was more frequently classified as inflammation with MR-E compared with PET/MR-E [p = 0.019]. Out of 8 patients with predominantly inflammatory CD who received medical treatment, 6 [75%] remained surgery free. Overall, 29 patients received surgery. At median follow-up of 9 [6-22] months, no recurrences occurred in either the medical or the surgical group. Preoperative PET/MR-E imaging is highly accurate for assessing CD lesions before operation and contributed to clinical management of patients with small-bowel CD more often than PET/CT-E. Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  5. ACR accreditation of nuclear medicine and PET imaging departments.

    Science.gov (United States)

    MacFarlane, Carolyn Richards

    2006-03-01

    The accreditation programs of the American College of Radiology (ACR) are the most established and widely proven for all imaging modalities. For facilities committed to quality imaging, the ACR Nuclear Medicine and PET Accreditation Program provides a solid foundation for a continuous quality improvement program through a peer review and educational process. This article provides general information describing the goals and development of the ACR accreditation programs. The ACR Nuclear Medicine and PET Accreditation Program evaluates the qualifications of personnel, equipment, image quality, and quality control measures. It is believed that these are the primary factors that have an impact on the quality of patient imaging. This article describes the application process, including the clinical examinations that are required and the quality control and performance tests that are expected from each facility. Outcomes and pass/fail statistics are discussed, as are common pitfalls that may cause deficiencies. Upon completion of this article, the reader should be able to describe the application process, the components of the ACR accreditation program, the most common causes for failure, and the site survey process.

  6. Diagnostic Accuracy of 18F-FDG PET/CT in Infective Endocarditis and Implantable Cardiac Electronic Device Infection: A Cross-Sectional Study.

    Science.gov (United States)

    Granados, Ulises; Fuster, David; Pericas, Juan M; Llopis, Jaime L; Ninot, Salvador; Quintana, Eduard; Almela, Manel; Paré, Carlos; Tolosana, José M; Falces, Carlos; Moreno, Asuncion; Pons, Francesca; Lomeña, Francisco; Miro, Jose M

    2016-11-01

    Early diagnosis of infective endocarditis (IE) is based on the yielding of blood cultures and echocardiographic findings. However, they have limitations and sometimes the diagnosis is inconclusive, particularly in patients with prosthetic valves (PVs) and implantable cardiac electronic devices (ICEDs). The primary aim of this study was to evaluate the diagnostic accuracy of 18F-FDG PET/CT in patients with suspected IE and ICED infection. A prospective study with 80 consecutive patients with suspected IE and ICED infection (65 men and 15 women with a mean age of 68 ± 13 y) between June 2013 and May 2015 was performed in our hospital. The inclusion criteria were clinically suspected IE and ICED infection at the following locations: native valve (NV) (n = 21), PV (n = 29), or ICED (n = 30) (automatic implantable defibrillator [n = 11] or pacemaker [n = 19]). Whole-body 18F-FDG PET/CT with a myocardial uptake suppression protocol with unfractionated heparin was performed in all patients. The final diagnosis of infection was established by the IE Study Group according to the clinical, echocardiographic, and microbiologic findings. A final diagnosis of infection was confirmed in 31 patients: NV (n = 6), PV (n = 12), and ICED (n = 13). Sensitivity, specificity, positive predictive value, and negative predictive value for 18F-FDG PET/CT were 82%, 96%, 94%, and 87%, respectively. 18F-FDG PET/CT was false-negative in all cases with infected NV. 18F-FDG PET/CT was able to reclassify 63 of 70 (90%) patients initially classified as possible IE by modified Duke criteria. In 18 of 70 cases, 18F-FDG PET/CT changed possible to definite IE (26%) and in 45 of 70 cases changed possible to rejected IE (64%). Additionally, 18F-FDG PET/CT identified 8 cases of septic embolism and 3 of colorectal cancer in patients with a final diagnosis of IE. 18F-FDG PET/CT proved to be a useful diagnostic tool in suspected IE and ICED infection and should be included in the diagnostic algorithm for

  7. How to differentiate benign versus malignant cardiac and paracardiac 18F FDG uptake at oncologic PET/CT.

    Science.gov (United States)

    Maurer, Alan H; Burshteyn, Mark; Adler, Lee P; Steiner, Robert M

    2011-01-01

    Patients undergoing 2-[fluorine 18]fluoro-2-deoxy-d-glucose (FDG) whole-body oncologic positron emission tomography (PET)/computed tomography (CT) are studied while fasting. Cardiac FDG uptake in fasted patients has been widely reported as variable. It is important to understand the normal patterns of cardiac FDG activity that can be seen in oncologic FDG PET/CT studies. These include focal and regional patterns of increased FDG myocardial activity. Focal activity can be observed in papillary muscles, the atria, the base, and the distal anteroapical region of the left ventricle. Regional increased cardiac FDG activity may be diffuse or localized in the posterolateral wall or the base of the left ventricle. Abnormal patterns of cardiac FDG activity not related to malignancy include those associated with lipomatous hypertrophy of the interatrial septum, epicardial and pericardial fat, increased atrial activity associated with atrial fibrillation or a prominent crista terminalis, cardiac sarcoidosis, endocarditis, myocarditis, and pericarditis. Knowledge of these patterns of cardiac FDG activity is important to be able to recognize malignant disease involving the paracardiac spaces, myocardium, and pericardium. With a better understanding of the range of normal and abnormal patterns of cardiac FDG activity, important benign and malignant diseases involving the heart and pericardium can be recognized and diagnosed.

  8. ASCI 2010 contrast media guideline for cardiac imaging: a report of the Asian Society of Cardiovascular Imaging cardiac computed tomography and cardiac magnetic resonance imaging guideline working group

    Science.gov (United States)

    Kitagawa, Kakuya; Tsai, I-Chen; Chan, Carmen; Yu, Wei; Yong, Hwan Seok; Choi, Byoung Wook

    2010-01-01

    The use of contrast media for cardiac imaging becomes increasing as the widespread of cardiac CT and cardiac MR. A radiologist needs to carefully consider the indication and the injection protocol of contrast media to be used as well as the possibility of adverse effect. There are several guidelines for contrast media in western countries. However, these are focusing the adverse effect of contrast media. The Asian Society of Cardiovascular Imaging, the only society dedicated to cardiovascular imaging in Asia, formed a Working Group and created a guideline, which summarizes the integrated knowledge of contrast media for cardiac imaging. In cardiac imaging, coronary artery evaluation is feasible by non-contrast MR angiography, which can be an alternative examination in high risk patients for the use of iodine contrast media. Furthermore, the body habitus of Asian patients is usually smaller than that of their western counterparts. This necessitates modifications in the injection protocol and in the formula for calculation of estimated glomerular filtration rate. This guideline provided fundamental information for the use of contrast media for Asian patients in cardiac imaging. PMID:20931289

  9. Clinical feasibility of {sup 90}Y digital PET/CT for imaging microsphere biodistribution following radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Chadwick L.; Binzel, Katherine; Zhang, Jun; Knopp, Michael V. [The Ohio State University Wexner Medical Center, Wright Center of Innovation in Biomedical Imaging, Department of Radiology, Columbus, OH (United States); Wuthrick, Evan J. [The Ohio State University Wexner Medical Center, Department of Radiation Oncology, Columbus, OH (United States)

    2017-07-15

    The purpose of this study was to evaluate the clinical feasibility of next generation solid-state digital photon counting PET/CT (dPET/CT) technology and imaging findings in patients following {sup 90}Y microsphere radioembolization in comparison with standard of care (SOC) bremsstrahlung SPECT/CT (bSPECT/CT). Five patients underwent SOC {sup 90}Y bremsstrahlung imaging immediately following routine radioembolization with 3.5 ± 1.7 GBq of {sup 90}Y-labeled glass microspheres. All patients also underwent dPET/CT imaging at 29 ± 11 h following radioembolization. Matched pairs comparison was used to compare image quality, image contrast and {sup 90}Y biodistribution between dPET/CT and bSPECT/CT images. Volumetric assessments of {sup 90}Y activity using different isocontour thresholds on dPET/CT and bSPECT/CT images were also compared. Digital PET/CT consistently provided better visual image quality and {sup 90}Y-to-background image contrast while depicting {sup 90}Y biodistribution than bSPECT/CT. Isocontour volumetric assessment using a 1% threshold precisely outlined {sup 90}Y activity and the treatment volume on dPET/CT images, whereas a more restrictive 20% threshold on bSPECT/CT images was needed to obtain comparable treatment volumes. The use of a less restrictive 10% threshold isocontour on bSPECT/CT images grossly overestimated the treatment volume when compared with the 1% threshold on dPET/CT images. Digital PET/CT is clinically feasible for the assessment of {sup 90}Y microsphere biodistribution following radioembolization, and provides better visual image quality and image contrast than routine bSPECT/CT with comparable acquisition times. With further optimization and clinical validation, dPET technology may allow faster and more accurate imaging-based assessment of {sup 90}Y microsphere biodistribution. (orig.)

  10. 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...

  11. 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.

  12. Quantitative Evaluation of Atlas-based Attenuation Correction for Brain PET in an Integrated Time-of-Flight PET/MR Imaging System.

    Science.gov (United States)

    Yang, Jaewon; Jian, Yiqiang; Jenkins, Nathaniel; Behr, Spencer C; Hope, Thomas A; Larson, Peder E Z; Vigneron, Daniel; Seo, Youngho

    2017-07-01

    Purpose To assess the patient-dependent accuracy of atlas-based attenuation correction (ATAC) for brain positron emission tomography (PET) in an integrated time-of-flight (TOF) PET/magnetic resonance (MR) imaging system. Materials and Methods Thirty recruited patients provided informed consent in this institutional review board-approved study. All patients underwent whole-body fluorodeoxyglucose PET/computed tomography (CT) followed by TOF PET/MR imaging. With use of TOF PET data, PET images were reconstructed with four different attenuation correction (AC) methods: PET with patient CT-based AC (CTAC), PET with ATAC (air and bone from an atlas), PET with ATACpatientBone (air and tissue from the atlas with patient bone), and PET with ATACboneless (air and tissue from the atlas without bone). For quantitative evaluation, PET mean activity concentration values were measured in 14 1-mL volumes of interest (VOIs) distributed throughout the brain and statistical significance was tested with a paired t test. Results The mean overall difference (±standard deviation) of PET with ATAC compared with PET with CTAC was -0.69 kBq/mL ± 0.60 (-4.0% ± 3.2) (P PET with ATACboneless (-9.4% ± 3.7) was significantly worse than that of PET with ATAC (-4.0% ± 3.2) (P PET with ATACpatientBone (-1.5% ± 1.5) improved over that of PET with ATAC (-4.0% ± 3.2) (P PET/MR imaging achieves similar quantification accuracy to that from CTAC by means of atlas-based bone compensation. However, patient-specific anatomic differences from the atlas causes bone attenuation differences and misclassified sinuses, which result in patient-dependent performance variation of ATAC. © RSNA, 2017 Online supplemental material is available for this article.

  13. Detection of Atherosclerotic Inflammation by $^{68}$Ga-DOTATATE PET Compared to [$^{18}$F]FDG PET Imaging

    OpenAIRE

    Tarkin, JM; Joshi, FR; Evans, NR; Chowdhury, MM; Figg, NL; Shah, AV; Starks, LT; Martin-Garrido, A; Manavaki, R; Yu, E; Kuc, RE; Grassi, L.; Kreuzhuber, R; Kostadima, MA; Frontini, M.

    2017-01-01

    $\\textbf{Background}$ Inflammation drives atherosclerotic plaque rupture. Although inflammation can be measured using fluorine-18-labeled fluorodeoxyglucose positron emission tomography ([$^{18}$F]FDG PET), [$^{18}$F]FDG lacks cell specificity, and coronary imaging is unreliable because of myocardial spillover. $\\textbf{Objectives}$ Objectives This study tested the efficacy of gallium-68-labeled DOTATATE ($^{68}$Ga-DOTATATE), a somatostatin receptor subtype-2 (SST2)-binding PET t...

  14. Cardiac carcinoid: tricuspid delayed hyperenhancement on cardiac 64-slice multidetector CT and magnetic resonance imaging.

    LENUS (Irish Health Repository)

    Martos, R

    2012-02-01

    INTRODUCTION: Carcinoid heart disease is a rare condition in adults. Its diagnosis can be easily missed in a patient presenting to a primary care setting. We revised the advantages of using coronary multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (MRI) in diagnosing this condition. MATERIALS AND METHODS: We studied a 65-year-old patient with carcinoid heart disease and right heart failure using transthoracic Doppler-echocardiogram, cardiac MDCT and MRI. Cardiac echocardiogram revealed marked thickening and retraction of the tricuspid leaflets with dilated right atrium and ventricle. Cardiac MDCT and MRI demonstrated fixation and retraction of the tricuspid leaflets with delayed contrast hyperenhancement of the tricuspid annulus. CONCLUSION: This case demonstrates fascinating imaging findings of cardiac carcinoid disease and highlights the increasing utility of contrast-enhanced MRI and cardiac MDCT in the diagnosis of this interesting condition.

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

    Science.gov (United States)

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

    2017-11-13

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

  16. MO-FG-207-00: Technological Advances in PET/MR Imaging

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    The use of integrated PET/MRI systems in clinical applications can best benefit from understanding their technological advances and limitations. The currently available clinical PET/MRI systems have their own characteristics. Thorough analyses of existing technical data and evaluation of necessary performance metrics for quality assurances could be conducted to optimize application-specific PET/MRI protocols. This Symposium will focus on technical advances and limitations of clinical PET/MRI systems, and how this exciting imaging modality can be utilized in applications that can benefit from both PET and MRI. Learning Objectives: To understand the technological advances of clinical PET/MRI systems To correctly identify clinical applications that can benefit from PET/MRI To understand ongoing work to further improve the current PET/MRI technology Floris Jansen is a GE Healthcare employee.

  17. Advantages of percutaneous abdominal biopsy under PET-CT/ultrasound fusion imaging guidance: a pictorial essay.

    Science.gov (United States)

    Paparo, Francesco; Piccazzo, Riccardo; Cevasco, Luca; Piccardo, Arnoldo; Pinna, Francesco; Belli, Fiorenza; Bacigalupo, Lorenzo; Biscaldi, Ennio; De Caro, Giovanni; Rollandi, Gian Andrea

    2014-10-01

    Positron emission tomography (PET) is a functional imaging technique that can investigate the metabolic characteristics of tissues. Currently, PET images are acquired and co-registered with a computed tomography (CT) scan (PET-CT), which is employed for correction of attenuation and anatomical localization. In spite of the high negative predictive value of PET, false-positive results may occur; indeed, Fluorine 18 ((18)F)-fluorodeoxyglucose ((18)F-FDG) uptake is not specific to cancer. As (18)F-FDG uptake may also be seen in non-malignant infectious or inflammatory processes, FDG-avid lesions may necessitate biopsy to confirm or rule out malignancy. However, some PET-positive lesions may have little or no correlative ultrasound (US) and/or CT findings (i.e., low conspicuity on morphological imaging). Since it is not possible to perform biopsy under PET guidance alone, owing to intrinsic technical limitations, PET information has to be integrated into a CT- or US-guided biopsy procedure (multimodal US/PET-CT fusion imaging). The purpose of this pictorial essay is to describe the technique of multimodal imaging fusion between real-time US and PET/CT, and to provide an overview of the clinical settings in which this multimodal integration may be useful in guiding biopsy procedures in PET-positive abdominal lesions.

  18. 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.

  19. Pet Imaging Of The Chemistry Of The Brain

    Science.gov (United States)

    Wagner, Henry N., Jr.

    1986-06-01

    Advances in neurobiology today are as important as the advances in atomic physics at the turn of the century and molecular genetics in the 1950's. Positron-emission tomography is participating in these advances by making it possible for the first time to measure the chemistry of the living human brain in health and disease and to relate the changes at the molecular level to the functioning of the human mind. The amount of data generated requires modern data processing, display, and archiving capabilities. To achieve maximum benefit from the PET imaging and the derived quantitative measurements, the data must be combined with information, usually of a structural nature, from other imaging modalities, chiefly computed tomography and magnetic resonance imaging.

  20. Non-oncologic Applications of PET/CT and PET/MR in Musculoskeletal, Orthopedic, and Rheumatologic Imaging: General Considerations, Techniques, and Radiopharmaceuticals.

    Science.gov (United States)

    Gholamrezanezhad, Ali; Basques, Kyle; Batouli, Ali; Olyaie, Mojtaba; Matcuk, George; Alavi, Abass; Jadvar, Hossein

    2017-11-10

    Positron Emission Tomography (PET) is often underutilized in the field of musculoskeletal imaging, with key reasons including the excellent performance of conventional musculoskeletal MRI, the limited spatial resolution of PET, and the lack of reimbursement for PET for non-oncologic musculoskeletal indications. However, with improvements in PET/CT and PET/MR imaging over the last decade as well as an increased understanding of the pathophysiology of musculoskeletal diseases, there is an emerging potential for PET as a primary or complementary modality in the management of rheumatologic and orthopedic patients. Specific advantages of PET include the convenience of whole body imaging in a single session, the relative resilience of the modality in the imaging of metallic implants compared to CT and MRI, the ability to evaluate deep joints not amenable to palpation, and the potential for improved specificity of diagnosis with novel radiopharmaceuticals. In this review, we discuss multiple radiopharmaceuticals and technical consideration of PET/CT and PET/MRI that can be employed in imaging of non-tumoral bone and soft tissue disorders. Both PET/CT and PET/MR hold significant promise in the field of musculoskeletal imaging, and with further radiopharmaceutical development and clinical research, these hybrid modalities can potentially transform the current management of patients with orthopedic and rheumatologic disease. Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  1. Self-gated cardiac cine imaging using phase information.

    Science.gov (United States)

    Seo, Hyunseok; Kim, Dongchan; Oh, Changheun; Park, HyunWook

    2017-03-01

    To obtain multiphase cardiac cine images with high resolution, a novel self-gating method for both cardiac and respiratory motions is proposed. The proposed method uses the phase of projection data obtained from a separate axial slice to measure cardiac and respiratory motion, after the acquisition of every k-space line in the image plane. Cardiac motion is estimated from the phase of the projection data passing through the aorta, which is amplified by superior-inferior directional bipolar gradients, whereas respiratory motion is estimated from the phase of the left-right directional projection data of the abdomen. To verify the proposed self-gating method, a simulation and in vivo steady state free precession cardiac imaging were performed. The proposed method provides high resolution multiphase cardiac cine images. Using the proposed self-gating method, the phase variation of the projection data offers information about cardiac and respiratory motions that is equivalent to external gating devices. The proposed method can capture time-resolved cardiac and respiratory motion from the phase information of the projection data. Because the projection data is obtained from a separate gating slice, the self-gating signals are not affected by imaging planes. Magn Reson Med 77:1216-1222, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  2. Characterization of the impact to PET quantification and image quality of an anterior array surface coil for PET/MR imaging.

    Science.gov (United States)

    Wollenweber, Scott D; Delso, Gaspar; Deller, Timothy; Goldhaber, David; Hüllner, Martin; Veit-Haibach, Patrick

    2014-04-01

    The aim of this study was to determine the impact to PET quantification, image quality and possible diagnostic impact of an anterior surface array used in a combined PET/MR imaging system. An extended oval phantom and 15 whole-body FDG PET/CT subjects were re-imaged for one bed position following placement of an anterior array coil at a clinically realistic position. The CT scan, used for PET attenuation correction, did not include the coil. Comparison, including liver SUV(mean), was performed between the coil present and absent images using two methods of PET reconstruction. Due to the time delay between PET scans, a model was used to account for average physiologic time change of SUV. On phantom data, neglecting the coil caused a mean bias of -8.2% for non-TOF/PSF reconstruction, and -7.3% with TOF/PSF. On clinical data, the liver SUV neglecting the coil presence fell by -6.1% (± 6.5%) for non-TOF/PSF reconstruction; respectively -5.2% (± 5.3%) with TOF/PSF. All FDG-avid features seen with TOF/PSF were also seen with non-TOF/PSF reconstruction. Neglecting coil attenuation for this anterior array coil results in a small but significant reduction in liver SUV(mean) but was not found to change the clinical interpretation of the PET images.

  3. Patient motion effects on the quantification of regional myocardial blood flow with dynamic PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, Chad R. R. N.; Kemp, Robert A. de, E-mail: RAdeKemp@ottawaheart.ca [Physics Department, Room 3302 Herzberg Laboratories, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada and Cardiac Imaging, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7 (Canada); Klein, Ran [Department of Nuclear Medicine, Ottawa Hospital, Civic Campus, 1053 Carling Avenue, Ottawa, Ontario K1Y 4E9 (Canada); Beanlands, Rob S. [Cardiac Imaging, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7 (Canada)

    2016-04-15

    Purpose: Patient motion is a common problem during dynamic positron emission tomography (PET) scans for quantification of myocardial blood flow (MBF). The purpose of this study was to quantify the prevalence of body motion in a clinical setting and evaluate with realistic phantoms the effects of motion on blood flow quantification, including CT attenuation correction (CTAC) artifacts that result from PET–CT misalignment. Methods: A cohort of 236 sequential patients was analyzed for patient motion under resting and peak stress conditions by two independent observers. The presence of motion, affected time-frames, and direction of motion was recorded; discrepancy between observers was resolved by consensus review. Based on these results, patient body motion effects on MBF quantification were characterized using the digital NURBS-based cardiac-torso phantom, with characteristic time activity curves (TACs) assigned to the heart wall (myocardium) and blood regions. Simulated projection data were corrected for attenuation and reconstructed using filtered back-projection. All simulations were performed without noise added, and a single CT image was used for attenuation correction and aligned to the early- or late-frame PET images. Results: In the patient cohort, mild motion of 0.5 ± 0.1 cm occurred in 24% and moderate motion of 1.0 ± 0.3 cm occurred in 38% of patients. Motion in the superior/inferior direction accounted for 45% of all detected motion, with 30% in the superior direction. Anterior/posterior motion was predominant (29%) in the posterior direction. Left/right motion occurred in 24% of cases, with similar proportions in the left and right directions. Computer simulation studies indicated that errors in MBF can approach 500% for scans with severe patient motion (up to 2 cm). The largest errors occurred when the heart wall was shifted left toward the adjacent lung region, resulting in a severe undercorrection for attenuation of the heart wall. Simulations

  4. 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.

  5. PET/MR Imaging in Head and Neck Cancer: Current Applications and Future Directions.

    Science.gov (United States)

    Galgano, Samuel J; Marshall, Ryan V; Middlebrooks, Erik H; McConathy, Jonathan E; Bhambhvani, Pradeep

    2018-02-01

    Clinical PET/MR imaging is being implemented at institutions worldwide as part of the standard-of-care imaging for select oncology patients. This article focuses on oncologic applications of PET/MR imaging in cancers of the head and neck. Although current published literature is relatively sparse, the potential benefits of a hybrid modality of PET/MR imaging are discussed along with several possible areas of research. With the increasing number of PET/MR imaging scanners in clinical use and ongoing research, the role of PET/MR imaging in the management of head and neck cancer is likely to become more evident in the near future. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    Tian, Mei; Chen, Qiaozhen; Zhang, Ying; Du, Fenglei; Hou, Haifeng; Chao, Fangfang; Zhang, Hong

    2014-07-01

    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 (11)C-N-methylspiperone ((11)C-NMSP) to assess the availability of D2/5-HT2A receptors and with (18)F-fluoro-D-glucose ((18)F-FDG) to assess regional brain glucose metabolism, a marker of brain function. (11)C-NMSP and (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 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.

  7. 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.)

  8. 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.

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

    NARCIS (Netherlands)

    Aide, N.; Visser, E.P.; Lheureux, S.; Heutte, N.; Szanda, I.; Hicks, R.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

  10. Development of F-18-IL2 : a PET radiotracer for imaging activated T-cells

    NARCIS (Netherlands)

    van der Veen, Elly L.; Maarsingh, Petra; van Scheltinga, Anton G. T. Terwisscha; Lub-de Hooge, Marjolijn N.; Hospers, G.A.P.; Vries, de Erik; Vries, de Elisabeth G. E.

    2016-01-01

    Introduction: Activation of T-cells is accompanied by a strong up-regulation of interleukin-2 (IL2) receptor (CD25). Therefore PET imaging of IL2 receptors might be a suitable imaging biomarker for T-cell activation. 18F-IL2 PET could detect CD25-positive T-cells and the migration of these T-cells

  11. The future of hybrid imaging—part 3: PET/MR, small-animal imaging and beyond

    National Research Council Canada - National Science Library

    Beyer, Thomas; Freudenberg, Lutz S; Czernin, Johannes; Townsend, David W

    2011-01-01

    ... (MRI). Unlike PET/computed tomography (CT), PET/MRI started out from developments in small-animal imaging technology, and, therefore, we add a section on advances in dual- and multi-modality imaging technology for small animals...

  12. Multimodality Imaging in Cardiac Sarcoidosis: Is There a Winner?

    Science.gov (United States)

    Perez, Irving E.; Garcia, Mario J.; Taub, Cynthia C.

    2016-01-01

    Sarcoidosis is a multisystem granulomatous disease of unknown cause that can affect the heart. Cardiac sarcoidosis may be present in as many as 25% of patients with systemic sarcoidosis, and it is frequently underdiagnosed. The early and accurate diagnosis of myocardial involvement is challenging. Advanced imaging techniques play important roles in the diagnosis and management of patients with cardiac sarcoidosis. PMID:25784137

  13. Advances in cardiac magnetic resonance imaging of congenital heart disease

    NARCIS (Netherlands)

    Driessen, Mieke M P; Breur, Johannes M. P. J.; Budde, Ricardo P J; van Oorschot, Joep W M; van Kimmenade, Roland R J; Sieswerda, Gertjan Tj.; Meijboom, Folkert J; Leiner, Tim

    Due to advances in cardiac surgery, survival of patients with congenital heart disease has increased considerably during the past decades. Many of these patients require repeated cardiovascular magnetic resonance imaging to assess cardiac anatomy and function. In the past decade, technological

  14. Advances in cardiac magnetic resonance imaging of congenital heart disease

    NARCIS (Netherlands)

    Driessen, M.M.; Breur, J.M.; Budde, R.P.; Oorschot, J.W. van; Kimmenade, R.R. van; Sieswerda, G.T.; Meijboom, F.J.; Leiner, T.

    2015-01-01

    Due to advances in cardiac surgery, survival of patients with congenital heart disease has increased considerably during the past decades. Many of these patients require repeated cardiovascular magnetic resonance imaging to assess cardiac anatomy and function. In the past decade, technological

  15. Cardiac Physiology for Radiologists: Review of Relevant Physiology for Interpretation of Cardiac MR Imaging and CT.

    Science.gov (United States)

    Sheth, Pooja J; Danton, Gary H; Siegel, Yoel; Kardon, Richard E; Infante, Juan C; Ghersin, Eduard; Fishman, Joel E

    2015-01-01

    Cardiac computed tomography (CT) and magnetic resonance (MR) imaging provide clinicians with important insights into cardiac physiology and pathology. However, not all radiologists understand the language and concepts of cardiac physiology that are used daily by cardiologists. This review article covers basic cardiac physiology as it relates to cardiac CT and MR imaging. Topics include a review of the cardiac cycle and left ventricular pressure-volume loops as they relate to different pathologic states, evaluation of cardiac function, and calculation of key parameters such as left ventricular volumes and the ejection fraction. The hemodynamics of cardiac shunts are covered, with an emphasis on factors important to cardiologists, including the ratio of pulmonary flow to systemic flow. Additionally, valvular physiologic function is reexamined, with a focus on understanding pressure gradients within the heart and also the changes associated with valvular pathologic conditions, including measurement of regurgitant fractions in patients with valvular insufficiency. Understanding these basic concepts will help radiologists tailor the reporting of cardiac studies to clinically relevant information. (©)RSNA, 2015.

  16. 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....

  17. Quantitative image reconstruction for total-body PET imaging using the 2-meter long EXPLORER scanner.

    Science.gov (United States)

    Zhang, Xuezhu; Zhou, Jian; Cherry, Simon R; Badawi, Ramsey D; Qi, Jinyi

    2017-03-21

    The EXPLORER project aims to build a 2 meter long total-body PET scanner, which will provide extremely high sensitivity for imaging the entire human body. It will possess a range of capabilities currently unavailable to state-of-the-art clinical PET scanners with a limited axial field-of-view. The huge number of lines-of-response (LORs) of the EXPLORER poses a challenge to the data handling and image reconstruction. The objective of this study is to develop a quantitative image reconstruction method for the EXPLORER and compare its performance with current whole-body scanners. Fully 3D image reconstruction was performed using time-of-flight list-mode data with parallel computation. To recover the resolution loss caused by the parallax error between crystal pairs at a large axial ring difference or transaxial radial offset, we applied an image domain resolution model estimated from point source data. To evaluate the image quality, we conducted computer simulations using the SimSET Monte-Carlo toolkit and XCAT 2.0 anthropomorphic phantom to mimic a 20 min whole-body PET scan with an injection of 25 MBq 18 F-FDG. We compare the performance of the EXPLORER with a current clinical scanner that has an axial FOV of 22 cm. The comparison results demonstrated superior image quality from the EXPLORER with a 6.9-fold reduction in noise standard deviation comparing with multi-bed imaging using the clinical scanner.

  18. Quantitative image reconstruction for total-body PET imaging using the 2-meter long EXPLORER scanner

    Science.gov (United States)

    Zhang, Xuezhu; Zhou, Jian; Cherry, Simon R.; Badawi, Ramsey D.; Qi, Jinyi

    2017-03-01

    The EXPLORER project aims to build a 2 meter long total-body PET scanner, which will provide extremely high sensitivity for imaging the entire human body. It will possess a range of capabilities currently unavailable to state-of-the-art clinical PET scanners with a limited axial field-of-view. The huge number of lines-of-response (LORs) of the EXPLORER poses a challenge to the data handling and image reconstruction. The objective of this study is to develop a quantitative image reconstruction method for the EXPLORER and compare its performance with current whole-body scanners. Fully 3D image reconstruction was performed using time-of-flight list-mode data with parallel computation. To recover the resolution loss caused by the parallax error between crystal pairs at a large axial ring difference or transaxial radial offset, we applied an image domain resolution model estimated from point source data. To evaluate the image quality, we conducted computer simulations using the SimSET Monte-Carlo toolkit and XCAT 2.0 anthropomorphic phantom to mimic a 20 min whole-body PET scan with an injection of 25 MBq 18F-FDG. We compare the performance of the EXPLORER with a current clinical scanner that has an axial FOV of 22 cm. The comparison results demonstrated superior image quality from the EXPLORER with a 6.9-fold reduction in noise standard deviation comparing with multi-bed imaging using the clinical scanner.

  19. Bayesian statistics, factor analysis, and PET images I. Mathematical background.

    Science.gov (United States)

    Phillips, P R

    1989-01-01

    The problem of image reconstruction in positron emission tomography (PET) is examined, although the approach is quite general and may have other applications. The approach is based on the maximum-likelihood method L.A. Shepp and Y. Vardi (1982), with their assumption that the number of image pixels is greater than the number of data points. In this situation a (nonunique) solution can be written down directly, although it is not guaranteed to be positive definite. The arbitrariness in this solution can be precisely characterized by a geometric argument. A unique solution can be obtained only by introducing prior information. It is suggested that factor analysis is an efficient way to do this. In the simplest application of the method, the solution is written as the sum of two parts, r(alpha )+t(alpha), where r(alpha) is determined solely by the data and t(alpha) is determined by r(alpha) and the prior information.

  20. Non rigid respiratory motion correction in whole body PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fayad, Hadi [INSERM UMR1101, LaTIM, Brest (France); Schmidt, Holger [Université de Bretagne Occidentale, Brest (France); Wuerslin, Christian [University Hospital of Tübingen (Germany); Visvikis, Dimitris [INSERM UMR1101, LaTIM, Brest (France)

    2014-07-29

    Respiratory motion in PET/MR imaging leads to reduced quantitative and qualitative image accuracy. Correction methodologies include the use of respiratory synchronized gated frames which lead to low signal to noise ratio (SNR) given that each frame contains only part of the count available throughout an average PET acquisition. In this work, 4D MRI extracted elastic transformations were applied to list-mode data either inside the image reconstruction or to the reconstructed respiratory synchronized images to obtain respiration corrected PET images.

  1. 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.  ...

  2. Technical Considerations on Scanning and Image Analysis for Amyloid PET in Dementia.

    Science.gov (United States)

    Akamatsu, Go; Ohnishi, Akihito; Aita, Kazuki; Ikari, Yasuhiko; Yamamoto, Yasuji; Senda, Michio

    2017-01-01

    Brain imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET), can provide essential and objective information for the early and differential diagnosis of dementia. Amyloid PET is especially useful to evaluate the amyloid-β pathological process as a biomarker of Alzheimer's disease. This article reviews critical points about technical considerations on the scanning and image analysis methods for amyloid PET. Each amyloid PET agent has its own proper administration instructions and recommended uptake time, scan duration, and the method of image display and interpretation. In addition, we have introduced general scanning information, including subject positioning, reconstruction parameters, and quantitative and statistical image analysis. We believe that this article could make amyloid PET a more reliable tool in clinical study and practice.

  3. PET measures of pre- and post-synaptic cardiac beta adrenergic function

    Energy Technology Data Exchange (ETDEWEB)

    Link, Jeanne M.; Stratton, John R.; Levy, Wayne; Poole, Jeanne E.; Shoner, Steven C.; Stuetzle, Werner; Caldwell, James H. E-mail: jcald@u.washington.edu

    2003-11-01

    Positron Emission Tomography was used to measure global and regional cardiac {beta}-adrenergic function in 19 normal subjects and 9 congestive heart failure patients. [{sup 11}C]-meta-hydroxyephedrine was used to image norepinephrine transporter function as an indicator of pre-synaptic function and [{sup 11}C]-CGP12177 was used to measure cell surface {beta}-receptor density as an indicator of post-synaptic function. Pre-synaptic, but not post-synaptic, function was significantly different between normals and CHF patients. Pre-synaptic function was well matched to post-synaptic function in the normal hearts but significantly different and poorly matched in the CHF patients studied. This imaging technique can help us understand regional sympathetic function in cardiac disease.

  4. The Emerging Role of PET/MR Imaging in Gynecologic Cancers.

    Science.gov (United States)

    Ponisio, Maria Rosana; Fowler, Kathryn J; Dehdashti, Farrokh

    2016-10-01

    This article summarizes recent advances in PET/MR imaging in gynecologic cancers and the emerging clinical value of PET/MR imaging in the management of the 3 most common gynecologic malignancies: cervical, endometrial, and ovarian cancers. PET/MR imaging offers superior soft tissue contrast, improved assessment of primary tumor involvement because of high-resolution multiplanar reformats, and functional MR techniques such as diffusion-weighted MR imaging and dynamic contrast-enhanced MR imaging. This article discusses the challenges, future directions, and technical advances of PET/MR imaging, and the emerging new multimodality, multiparametric imaging techniques for integrating morphologic, functional, and molecular imaging data. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. 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...

  6. Applying Amide Proton Transfer MR Imaging to Hybrid Brain PET/MR: Concordance with Gadolinium Enhancement and Added Value to [(18)F]FDG PET.

    Science.gov (United States)

    Sun, Hongzan; Xin, Jun; Zhou, Jinyuan; Lu, Zaiming; Guo, Qiyong

    2017-10-23

    The purpose of this study is to evaluate the diagnostic concordance and metric correlations of amide proton transfer (APT) imaging with gadolinium-enhanced magnetic resonance imaging (MRI) and 2-deoxy-2-[(18)F-]fluoro-D-glucose ([(18)F]FDG) positron emission tomography (PET), using hybrid brain PET/MRI. Twenty-one subjects underwent brain gadolinium-enhanced [(18)F]FDG PET/MRI prospectively. Imaging accuracy was compared between unenhanced MRI, MRI with enhancement, APT-weighted (APTW) images, and PET based on six diagnostic criteria. Among tumors, the McNemar test was further used for concordance assessment between gadolinium-enhanced imaging, APT imaging, and [(18)F]FDG PET. As well, the relation of metrics between APT imaging and PET was analyzed by the Pearson correlation analysis. APT imaging and gadolinium-enhanced MRI showed superior and similar diagnostic accuracy. APTW signal intensity and gadolinium enhancement were concordant in 19 tumors (100 %), while high [(18)F]FDG avidity was shown in only 12 (63.2 %). For the metrics from APT imaging and PET, there was significant correlation for 13 hypermetabolic tumors (P PET in the evaluation of tumor metabolic activity during brain PET/MR studies.

  7. Malignant pleural mesothelioma: initial experience in integrated (18)F-FDG PET/MR imaging.

    Science.gov (United States)

    Schaarschmidt, Benedikt M; Sawicki, Lino M; Gomez, Benedikt; Grueneisen, Johannes; Hoiczyk, Mathias; Heusch, Philipp; Buchbender, Christian

    2016-01-01

    This study aims to compare staging results of (18)F-FDG PET/computed tomography (CT) and integrated PET/magnetic resonance (MR) in malignant pleural mesothelioma (MPM) patients and to investigate a potential apparent diffusion coefficient (ADC)/SUV correlation. Six patients with MPM underwent (18)F-FDG PET/CT and PET/MR including diffusion-weighted imaging. Thoracic TNM staging was performed for both modalities. SUV and ADC were assessed in therapy-naive pleural lesions. In thoracic TNM staging, no differences were found between PET/CT and PET/MR. An inverse correlation was observed between SUVmean and ADCmin (r=-0.63, P=.002). MPM can be staged using PET/MR. The inverse correlation ADC/SUV indicates that future research on multiparametric therapy response evaluation may be warranted. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Direct Parametric Image Reconstruction in Reduced Parameter Space for Rapid Multi-Tracer PET Imaging.

    Science.gov (United States)

    Cheng, Xiaoyin; Li, Zhoulei; Liu, Zhen; Navab, Nassir; Huang, Sung-Cheng; Keller, Ulrich; Ziegler, Sibylle; Shi, Kuangyu

    2015-02-12

    The separation of multiple PET tracers within an overlapping scan based on intrinsic differences of tracer pharmacokinetics is challenging, due to limited signal-to-noise ratio (SNR) of PET measurements and high complexity of fitting models. In this study, we developed a direct parametric image reconstruction (DPIR) method for estimating kinetic parameters and recovering single tracer information from rapid multi-tracer PET measurements. This is achieved by integrating a multi-tracer model in a reduced parameter space (RPS) into dynamic image reconstruction. This new RPS model is reformulated from an existing multi-tracer model and contains fewer parameters for kinetic fitting. Ordered-subsets expectation-maximization (OSEM) was employed to approximate log-likelihood function with respect to kinetic parameters. To incorporate the multi-tracer model, an iterative weighted nonlinear least square (WNLS) method was employed. The proposed multi-tracer DPIR (MTDPIR) algorithm was evaluated on dual-tracer PET simulations ([18F]FDG and [11C]MET) as well as on preclinical PET measurements ([18F]FLT and [18F]FDG). The performance of the proposed algorithm was compared to the indirect parameter estimation method with the original dual-tracer model. The respective contributions of the RPS technique and the DPIR method to the performance of the new algorithm were analyzed in detail. For the preclinical evaluation, the tracer separation results were compared with single [18F]FDG scans of the same subjects measured 2 days before the dual-tracer scan. The results of the simulation and preclinical studies demonstrate that the proposed MT-DPIR method can improve the separation of multiple tracers for PET image quantification and kinetic parameter estimations.

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

    NARCIS (Netherlands)

    Boellaard, R.; O'Doherty, M.J.; Weber, W.A.; Mottaghy, F.M.; Lonsdale, M.N.; Stroobants, S.G.; Oyen, W.J.G.; Kotzerke, J.; Hoekstra, O.S.; Pruim, J.; Marsden, P.K.; Tatsch, K.; Hoekstra, C.J.; Visser, E.P.; Arends, B.; Verzijlbergen, F.J.; Zijlstra, J.M.; Comans, E.F.I.; Lammertsma, A.A.; Paans, A.M.; Willemsen, A.T.; Beyer, T.; Bockisch, A.; Schaefer-Prokop, C.; Delbeke, D.; Baum, R.P.; Chiti, A.; Krause, B.J.

    2010-01-01

    The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about [18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed

  10. Molecular imaging of head and neck cancers. Perspectives of PET/MRI; Molekulare Bildgebung bei Kopf-ï]¿Hals-Tumoren. Perspektive der PET-MRT

    Energy Technology Data Exchange (ETDEWEB)

    Stumpp, P.; Kahn, T. [Universitaetsklinikum Leipzig AoeR, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Leipzig (Germany); Purz, S.; Sabri, O. [Universitaetsklinikum Leipzig, Klinik und Poliklinik fuer Nuklearmedizin, Leipzig (Germany)

    2016-07-15

    The {sup 18}F-fluorodeoxyglucose positron emission tomography-computed tomography ({sup 18}F-FDG-PET/CT) procedure is a cornerstone in the diagnostics of head and neck cancers. Several years ago PET-magnetic resonance imaging (PET/MRI) also became available as an alternative hybrid multimodal imaging method. Does PET/MRI have advantages over PET/CT in the diagnostics of head and neck cancers ?The diagnostic accuracy of the standard imaging methods CT, MRI and PET/CT is depicted according to currently available meta-analyses and studies concerning the use of PET/MRI for these indications are summarized. In all studies published up to now PET/MRI did not show superiority regarding the diagnostic accuracy in head and neck cancers; however, there is some evidence that in the future PET/MRI can contribute to tumor characterization and possibly be used to predict tumor response to therapy with the use of multiparametric imaging. Currently, {sup 18}F-FDG-PET/CT is not outperformed by PET/MRI in the diagnostics of head and neck cancers. The additive value of PET/MRI due to the use of multiparametric imaging needs to be investigated in future research. (orig.) [German] Die {sup 18}F-Fluordesoxyglukose-Positronenemissionstomographie-Computertomographie ({sup 18}F-FDG-PET-CT) hat ihren festen Stellenwert in der Diagnostik von Kopf-Hals-Tumoren. Seit einigen Jahren ist die PET-MRT als weitere hybride Bildgebungsmodalitaet verfuegbar. Bringt die PET-MRT Fortschritte bei der Diagnostik von Kopf-Hals-Tumoren ?Darstellung der diagnostischen Genauigkeit der bisherigen Bildgebungsmethoden CT, MRT und PET-CT anhand von Metaanalysen und Zusammenfassung der bisherigen Publikationen zur PET-MRT auf diesem Gebiet. Die PET-MRT zeigt in allen bisherigen Studien keine Ueberlegenheit bzgl. der diagnostischen Genauigkeit von Kopf-Hals-Tumoren. Sie kann jedoch durch die multiparametrische Diagnostik perspektivisch Beitraege zur Tumorcharakterisierung und damit moeglicherweise Voraussagen zum

  11. An alternative approach to histopathological validation of PET imaging for radiation therapy image-guidance: a proof of concept.

    Science.gov (United States)

    Axente, Marian; He, Jun; Bass, Christopher P; Sundaresan, Gobalakrishnan; Zweit, Jamal; Williamson, Jeffrey F; Pugachev, Andrei

    2014-02-01

    In radiotherapy, PET images can be used to guide the delivery of selectively escalated doses to biologically relevant tumour subvolumes. Validation of PET for such applications requires demonstration of spatial coincidence between PET tracer uptake pattern and the histopathologically confirmed target. This study introduces a novel approach to histopathological validation of PET image segmentation for radiotherapy guidance. Sequential tissue sections from surgically excised whole-tumour specimens were used to acquire full 3D-sets of both histopathological images (microscopy) and PET tracer distribution images (autoradiography). After these datasets were accurately registered, a full 3D autoradiographic distribution of PET tracer was reconstructed and used to obtain synthetic PET images (sPET) by simulating the image deterioration induced by processes involved in PET image formation. To illustrate the method, sPET images were used in this study to investigate spatial coincidence between high FDG uptake areas and the distribution of viable tissue in two small animal tumour models. The reconstructed 3D autoradiographic distribution of the PET tracer was spatially coherent, as indicated by the high average value of the normalised pixel-by-pixel correlation of intensities between successive slices (0.84 ± 0.05 and 0.94 ± 0.02). The loss of detail in the sPET images versus the 3D autoradiography was significant as indicated by Dice coefficient values corresponding to the two tumours (0 and 0.1 at 70% threshold). The maximum overlap between the FDG segmented volumes and the extent of the viable tissue as indicated by Dice coefficient values, was 0.8 for one tumour (for the image thresholded at 22% of max intensity) and 0.88 for the other (threshold of 14% of max intensity). It was demonstrated that the use of synthetic PET images for histopathological validation allows for bypassing a technically challenging and error-prone step of registering non-invasive PET images

  12. Accelerating Dynamic Cardiac MR Imaging Using Structured Sparse Representation

    Directory of Open Access Journals (Sweden)

    Nian Cai

    2013-01-01

    Full Text Available Compressed sensing (CS has produced promising results on dynamic cardiac MR imaging by exploiting the sparsity in image series. In this paper, we propose a new method to improve the CS reconstruction for dynamic cardiac MRI based on the theory of structured sparse representation. The proposed method user the PCA subdictionaries for adaptive sparse representation and suppresses the sparse coding noise to obtain good reconstructions. An accelerated iterative shrinkage algorithm is used to solve the optimization problem and achieve a fast convergence rate. Experimental results demonstrate that the proposed method improves the reconstruction quality of dynamic cardiac cine MRI over the state-of-the-art CS method.

  13. PET/CT and MRI in the imaging assessment of cervical cancer.

    Science.gov (United States)

    Kusmirek, Joanna; Robbins, Jessica; Allen, Hailey; Barroilhet, Lisa; Anderson, Bethany; Sadowski, Elizabeth A

    2015-10-01

    Imaging plays a central role in the evaluation of patients with cervical cancer and helps guide treatment decisions. The purpose of this pictorial review is to describe magnetic resonance (MR) imaging and positron emission tomography (PET)/computed tomography (CT) assessment of cervical cancer, including indications for imaging, important findings that may result in management change, as well as limitations of both modalities. The International Federation of Gynecology and Obstetrics cervical cancer staging system does not officially include imaging; however, the organization endorses the use of MR imaging and PET/CT in the management of patients with cervical cancer where these modalities are available. MR imaging provides the best visualization of the primary tumor and extent of soft tissue disease. PET/CT is recommended for assessment of nodal involvement, as well as distant metastases. Both MR imaging and PET/CT are used to follow patients post-treatment to assess for recurrence. This review focuses on the current MR imaging and PET/CT protocols, the utility of these modalities in assessing primary tumors and recurrences, with emphasis on imaging findings which change management and on imaging pitfalls to avoid. It is important to be familiar with the MR imaging and PET/CT appearance of the primary tumor and metastasis, as well as the imaging pitfalls, so that an accurate assessment of disease burden is made prior to treatment.

  14. Clinical evaluation of 2D versus 3D whole-body PET image quality using a dedicated BGO PET scanner.

    Science.gov (United States)

    Visvikis, D; Griffiths, D; Costa, D C; Bomanji, J; Ell, P J

    2005-09-01

    Three-dimensional positron emission tomography (3D PET) results in higher system sensitivity, with an associated increase in the detection of scatter and random coincidences. The objective of this work was to compare, from a clinical perspective, 3D and two-dimensional (2D) acquisitions in terms of whole-body (WB) PET image quality with a dedicated BGO PET system. 2D and 3D WB emission acquisitions were carried out in 70 patients. Variable acquisition parameters in terms of time of emission acquisition per axial field of view (aFOV) and slice overlap between sequential aFOVs were used during the 3D acquisitions. 3D and 2D images were reconstructed using FORE+WLS and OSEM respectively. Scatter correction was performed by convolution subtraction and a model-based scatter correction in 2D and 3D respectively. All WB images were attenuation corrected using segmented transmission scans. Images were blindly assessed by three observers for the presence of artefacts, confidence in lesion detection and overall image quality using a scoring system. Statistically significant differences between 2D and 3D image quality were only obtained for 3D emission acquisitions of 3 min. No statistically significant differences were observed for image artefacts or lesion detectability scores. Image quality correlated significantly with patient weight for both modes of operation. Finally, no differences were seen in image artefact scores for the different axial slice overlaps considered, suggesting the use of five slice overlaps in 3D WB acquisitions. 3D WB imaging using a dedicated BGO-based PET scanner offers similar image quality to that obtained in 2D considering similar overall times of acquisitions.

  15. Clinical evaluation of 2D versus 3D whole-body PET image quality using a dedicated BGO PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Visvikis, D. [CHU Morvan, U650 INSERM, Laboratoire de Traitement de l' Information Medicale (LaTIM), Brest (France); Griffiths, D. [Lister Healthcare, London PET Centre, London (United Kingdom); Costa, D.C. [Middlesex Hospital, Institute of Nuclear Medicine, Royal Free and University College Medical School, London (United Kingdom); HPP Medicina Molecular, SA Porto (Portugal); Bomanji, J.; Ell, P.J. [Middlesex Hospital, Institute of Nuclear Medicine, Royal Free and University College Medical School, London (United Kingdom)

    2005-09-01

    Three-dimensional positron emission tomography (3D PET) results in higher system sensitivity, with an associated increase in the detection of scatter and random coincidences. The objective of this work was to compare, from a clinical perspective, 3D and two-dimensional (2D) acquisitions in terms of whole-body (WB) PET image quality with a dedicated BGO PET system. 2D and 3D WB emission acquisitions were carried out in 70 patients. Variable acquisition parameters in terms of time of emission acquisition per axial field of view (aFOV) and slice overlap between sequential aFOVs were used during the 3D acquisitions. 3D and 2D images were reconstructed using FORE+WLS and OSEM respectively. Scatter correction was performed by convolution subtraction and a model-based scatter correction in 2D and 3D respectively. All WB images were attenuation corrected using segmented transmission scans. Images were blindly assessed by three observers for the presence of artefacts, confidence in lesion detection and overall image quality using a scoring system. Statistically significant differences between 2D and 3D image quality were only obtained for 3D emission acquisitions of 3 min. No statistically significant differences were observed for image artefacts or lesion detectability scores. Image quality correlated significantly with patient weight for both modes of operation. Finally, no differences were seen in image artefact scores for the different axial slice overlaps considered, suggesting the use of five slice overlaps in 3D WB acquisitions. 3D WB imaging using a dedicated BGO-based PET scanner offers similar image quality to that obtained in 2D considering similar overall times of acquisitions. (orig.)

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

    DEFF Research Database (Denmark)

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

    2018-01-01

    BACKGROUND: The increasing use of the pig as a research model in neuroimaging requires standardized processing tools. For example, extraction of regional dynamic time series from brain PET images requires parcellation procedures that benefit from being automated. COMPARISON WITH EXISTING METHODS......: Manual inter-modality spatial normalization to a MRI atlas is operator-dependent, time-consuming, and can be inaccurate with lack of cortical radiotracer binding or skull uptake. NEW METHOD: A parcellated PET template that allows for automatic spatial normalization to PET images of any radiotracer....... RESULTS: MRI and [11C]Cimbi-36 PET scans obtained in sixteen pigs made the basis for the atlas. The high resolution MRI scans allowed for creation of an accurately averaged MRI template. By aligning the within-subject PET scans to their MRI counterparts, an averaged PET template was created in the same...

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

    DEFF Research Database (Denmark)

    Sun, Yao; Ma, Xiaowei; Zhang, Zhe

    2016-01-01

    (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...... 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.......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...

  18. PET/MR Imaging: New Frontier in Alzheimer's Disease and Other Dementias

    Directory of Open Access Journals (Sweden)

    Xin Y. Zhang

    2017-11-01

    Full Text Available Alzheimer's disease (AD is the most common form of dementia; a progressive neurodegenerative disease that currently lacks an effective treatment option. Early and accurate diagnosis, in addition to quick elimination of differential diagnosis, allows us to provide timely treatments that delay the progression of AD. Imaging plays an important role for the early diagnosis of AD. The newly emerging PET/MR imaging strategies integrate the advantages of PET and MR to diagnose and monitor AD. This review introduces the development of PET/MR imaging systems, technical considerations of PET/MR imaging, special considerations of PET/MR in AD, and the system's potential clinical applications and future perspectives in AD.

  19. FDG PET/MR in initial staging of sarcoma: Initial experience and comparison with conventional imaging.

    Science.gov (United States)

    Platzek, Ivan; Beuthien-Baumann, Bettina; Schramm, Georg; Maus, Jens; Laniado, Michael; Kotzerke, Jörg; van den Hoff, Jörg; Schuler, Markus

    To assess the feasibility of positron emission tomography/magnetic resonance imaging (PET/MR) with 18F-fluordeoxyglucose (FDG) for initial staging of sarcoma. Twenty-nine patients with sarcoma were included in this study. Weighted kappa (κ) was used to assess the agreement between PET/MR and conventional imaging (CT and MR). The accuracy of PET/MR and conventional imaging for distant metastases was compared using receiver operating characteristic (ROC) analysis. T and M stage were identical for PET/MR and conventional modalities in all patients (κ=1). N stage was identical for 28/29 patients (κ=0.65). FDG PET/MR shows excellent agreement with the currently preferred imaging methods (CT and MR) in initial staging of sarcoma. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. In Vivo PET Imaging of HDL in Multiple Atherosclerosis Models

    DEFF Research Database (Denmark)

    Pérez-Medina, Carlos; Binderup, Tina; Lobatto, Mark E

    2016-01-01

    OBJECTIVES: The goal of this study was to develop and validate a noninvasive imaging tool to visualize the in vivo behavior of high-density lipoprotein (HDL) by using positron emission tomography (PET), with an emphasis on its plaque-targeting abilities. BACKGROUND: HDL is a natural nanoparticle......,2-distearoyl-sn-glycero-3-phosphoethanolamine-deferoxamine B). Biodistribution and plaque targeting of radiolabeled HDL were studied in established murine, rabbit, and porcine atherosclerosis models by using PET combined with computed tomography (PET/CT) imaging or PET combined with magnetic resonance imaging......-injection for both (89)Zr-HDL nanoparticles. In the porcine model, increased accumulation of radioactivity was observed in lesions by using in vivo PET imaging. Irrespective of the radiolabel's location, HDL nanoparticles were able to preferentially target plaque macrophages and monocytes. CONCLUSIONS: (89)Zr...

  1. PET/MRI Imaging in High-Risk Sarcoma: First Findings and Solving Clinical Problems

    Directory of Open Access Journals (Sweden)

    Markus K. Schuler

    2013-01-01

    Full Text Available Simultaneous positron emission tomography (PET and magnetic resonance imaging (MRI is a new whole-body hybrid PET/MR imaging technique that combines metabolic and cross-sectional diagnostic imaging. Since the use of MRI in imaging of soft-tissue sarcoma is extremely beneficial, investigation of the combined PET/MRI is of great interest. In this paper, we present three cases and first data. Combined PET/MRI technique can support the process of clinical decision-making and give answers to some meaningful questions when treating patients with STS. Therefore, the combined modality of simultaneous PET/MRI offers new pieces to the puzzle of sarcoma treatment.

  2. Quantitative carotid PET/MR imaging: clinical evaluation of MR-Attenuation correction versus CT-Attenuation correction in (18)F-FDG PET/MR emission data and comparison to PET/CT.

    Science.gov (United States)

    Bini, Jason; Robson, Philip M; Calcagno, Claudia; Eldib, Mootaz; Fayad, Zahi A

    2015-01-01

    Current PET/MR systems employ segmentation of MR images and subsequent assignment of empirical attenuation coefficients for quantitative PET reconstruction. In this study we examine the differences in the quantification of (18)F-FDG uptake in the carotid arteries between PET/MR and PET/CT scanners. Five comparisons were performed to asses differences in PET quantification: i) PET/MR MR-based AC (MRAC) versus PET/MR CTAC, ii) PET/MR MRAC versus PET/CT, iii) PET/MR MRAC with carotid coil versus PET/MR MRAC without coil, iv) PET/MR MRAC scan 2 versus PET/MR MRAC scan 1, and v) PET/MR CTAC versus PET/CT. Standardized uptakes values (SUV) mean and SUV maximum were calculated for six regions-of-interests: left and right carotid arteries, left and right lungs, spine and muscle. Pearson's Correlation and Bland-Altman plots were used to compare SUV mean and maximum within each ROI of each patient. PET/MR emission data reconstructed with MRAC versus PET/MR emission data reconstructed with CTAC had percent differences of SUV mean ranging from -2.0% (Absolute Difference, -0.02) to 7.4% (absolute difference, 0.06). Percent differences within the carotid arteries proved to correlate well with differences of SUV mean of 5.4% (Absolute Difference, 0.07) in the left carotid and 2.7% (Absolute Difference, 0.03) in the right carotid. Pearson's correlation and Bland-Altman of PET/MR with MRAC versus PET/MR with CTAC showed high correlation between SUV mean (R(2)=0.80, mean difference 0.03 ± 0.18 SUV, p=0.3382), demonstrating excellent correlation within ROIs analyzed. The results of this study support the use of (18)F-FDG PET/MR for quantitative measure of inflammation in the carotid arteries.

  3. Quantitative carotid PET/MR imaging: clinical evaluation of MR-Attenuation correction versus CT-Attenuation correction in 18F-FDG PET/MR emission data and comparison to PET/CT

    Science.gov (United States)

    Bini, Jason; Robson, Philip M; Calcagno, Claudia; Eldib, Mootaz; Fayad, Zahi A

    2015-01-01

    Current PET/MR systems employ segmentation of MR images and subsequent assignment of empirical attenuation coefficients for quantitative PET reconstruction. In this study we examine the differences in the quantification of 18F-FDG uptake in the carotid arteries between PET/MR and PET/CT scanners. Five comparisons were performed to asses differences in PET quantification: i) PET/MR MR-based AC (MRAC) versus PET/MR CTAC, ii) PET/MR MRAC versus PET/CT, iii) PET/MR MRAC with carotid coil versus PET/MR MRAC without coil, iv) PET/MR MRAC scan 2 versus PET/MR MRAC scan 1, and v) PET/MR CTAC versus PET/CT. Standardized uptakes values (SUV) mean and SUV maximum were calculated for six regions-of-interests: left and right carotid arteries, left and right lungs, spine and muscle. Pearson’s Correlation and Bland-Altman plots were used to compare SUV mean and maximum within each ROI of each patient. PET/MR emission data reconstructed with MRAC versus PET/MR emission data reconstructed with CTAC had percent differences of SUV mean ranging from -2.0% (Absolute Difference, -0.02) to 7.4% (absolute difference, 0.06). Percent differences within the carotid arteries proved to correlate well with differences of SUV mean of 5.4% (Absolute Difference, 0.07) in the left carotid and 2.7% (Absolute Difference, 0.03) in the right carotid. Pearson’s correlation and Bland-Altman of PET/MR with MRAC versus PET/MR with CTAC showed high correlation between SUV mean (R2=0.80, mean difference 0.03 ± 0.18 SUV, p=0.3382), demonstrating excellent correlation within ROIs analyzed. The results of this study support the use of 18F-FDG PET/MR for quantitative measure of inflammation in the carotid arteries. PMID:26069863

  4. Joint MR-PET Reconstruction Using a Multi-Channel Image Regularizer.

    Science.gov (United States)

    Knoll, Florian; Holler, Martin; Koesters, Thomas; Otazo, Ricardo; Bredies, Kristian; Sodickson, Daniel K

    2017-01-01

    While current state of the art MR-PET scanners enable simultaneous MR and PET measurements, the acquired data sets are still usually reconstructed separately. We propose a new multi-modality reconstruction framework using second order Total Generalized Variation (TGV) as a dedicated multi-channel regularization functional that jointly reconstructs images from both modalities. In this way, information about the underlying anatomy is shared during the image reconstruction process while unique differences are preserved. Results from numerical simulations and in-vivo experiments using a range of accelerated MR acquisitions and different MR image contrasts demonstrate improved PET image quality, resolution, and quantitative accuracy.

  5. Image reconstruction of mMR PET data using the open source software STIR

    Energy Technology Data Exchange (ETDEWEB)

    Markiewicz, Pawel [Centre for Medical Image Computing, University College London, London (United Kingdom); Thielemans, Kris [Institute of Nuclear Medicine, University College London, London (United Kingdom); Burgos, Ninon [Centre for Medical Image Computing, University College London, London (United Kingdom); Manber, Richard [Institute of Nuclear Medicine, University College London, London (United Kingdom); Jiao, Jieqing [Centre for Medical Image Computing, University College London, London (United Kingdom); Barnes, Anna [Institute of Nuclear Medicine, University College London, London (United Kingdom); Atkinson, David [Centre for Medical Imaging, University College London, London (United Kingdom); Arridge, Simon R [Centre for Medical Image Computing, University College London, London (United Kingdom); Hutton, Brian F [Institute of Nuclear Medicine, University College London, London (United Kingdom); Ourselin, Sébastien [Centre for Medical Image Computing, University College London, London (United Kingdom); Dementia Research Centre, University College London, London (United Kingdom)

    2014-07-29

    Simultaneous PET and MR acquisitions have now become possible with the new hybrid Biograph Molecular MR (mMR) scanner from Siemens. The purpose of this work is to create a platform for mMR 3D and 4D PET image reconstruction which would be freely accessible to the community as well as fully adjustable in order to obtain optimal images for a given research task in PET imaging. The proposed platform is envisaged to prove useful in developing novel and robust image bio-markers which could then be adapted for use on the mMR scanner.

  6. Towards integration of PET/MR hybrid imaging into radiation therapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Paulus, Daniel H., E-mail: daniel.paulus@imp.uni-erlangen.de [Institute of Medical Physics, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen 91052 (Germany); Thorwath, Daniela [Section for Biomedical Physics, University Hospital for Radiation Oncology, Eberhard Karls University Tübingen, Tübingen 72076 (Germany); Schmidt, Holger [Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tübingen, Tübingen 72076 (Germany); Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Tübingen 72076 (Germany); Quick, Harald H. [Institute of Medical Physics, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen 91052 (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen 45141 (Germany); High Field and Hybrid MR-Imaging, University Hospital Essen, Essen 45147 (Germany)

    2014-07-15

    Purpose: Multimodality imaging has become an important adjunct of state-of-the-art radiation therapy (RT) treatment planning. Recently, simultaneous PET/MR hybrid imaging has become clinically available and may also contribute to target volume delineation and biological individualization in RT planning. For integration of PET/MR hybrid imaging into RT treatment planning, compatible dedicated RT devices are required for accurate patient positioning. In this study, prototype RT positioning devices intended for PET/MR hybrid imaging are introduced and tested toward PET/MR compatibility and image quality. Methods: A prototype flat RT table overlay and two radiofrequency (RF) coil holders that each fix one flexible body matrix RF coil for RT head/neck imaging have been evaluated within this study. MR image quality with the RT head setup was compared to the actual PET/MR setup with a dedicated head RF coil. PET photon attenuation and CT-based attenuation correction (AC) of the hardware components has been quantitatively evaluated by phantom scans. Clinical application of the new RT setup in PET/MR imaging was evaluated in anin vivo study. Results: The RT table overlay and RF coil holders are fully PET/MR compatible. MR phantom and volunteer imaging with the RT head setup revealed high image quality, comparable to images acquired with the dedicated PET/MR head RF coil, albeit with 25% reduced SNR. Repositioning accuracy of the RF coil holders was below 1 mm. PET photon attenuation of the RT table overlay was calculated to be 3.8% and 13.8% for the RF coil holders. With CT-based AC of the devices, the underestimation error was reduced to 0.6% and 0.8%, respectively. Comparable results were found within the patient study. Conclusions: The newly designed RT devices for hybrid PET/MR imaging are PET and MR compatible. The mechanically rigid design and the reproducible positioning allow for straightforward CT-based AC. The systematic evaluation within this study provides the

  7. Towards integration of PET/MR hybrid imaging into radiation therapy treatment planning.

    Science.gov (United States)

    Paulus, Daniel H; Thorwath, Daniela; Schmidt, Holger; Quick, Harald H

    2014-07-01

    Multimodality imaging has become an important adjunct of state-of-the-art radiation therapy (RT) treatment planning. Recently, simultaneous PET/MR hybrid imaging has become clinically available and may also contribute to target volume delineation and biological individualization in RT planning. For integration of PET/MR hybrid imaging into RT treatment planning, compatible dedicated RT devices are required for accurate patient positioning. In this study, prototype RT positioning devices intended for PET/MR hybrid imaging are introduced and tested toward PET/MR compatibility and image quality. A prototype flat RT table overlay and two radiofrequency (RF) coil holders that each fix one flexible body matrix RF coil for RT head/neck imaging have been evaluated within this study. MR image quality with the RT head setup was compared to the actual PET/MR setup with a dedicated head RF coil. PET photon attenuation and CT-based attenuation correction (AC) of the hardware components has been quantitatively evaluated by phantom scans. Clinical application of the new RT setup in PET/MR imaging was evaluated in anin vivo study. The RT table overlay and RF coil holders are fully PET/MR compatible. MR phantom and volunteer imaging with the RT head setup revealed high image quality, comparable to images acquired with the dedicated PET/MR head RF coil, albeit with 25% reduced SNR. Repositioning accuracy of the RF coil holders was below 1 mm. PET photon attenuation of the RT table overlay was calculated to be 3.8% and 13.8% for the RF coil holders. With CT-based AC of the devices, the underestimation error was reduced to 0.6% and 0.8%, respectively. Comparable results were found within the patient study. The newly designed RT devices for hybrid PET/MR imaging are PET and MR compatible. The mechanically rigid design and the reproducible positioning allow for straightforward CT-based AC. The systematic evaluation within this study provides the technical basis for the clinical

  8. 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

  9. Image reconstructions from super-sampled data sets with resolution modeling in PET imaging.

    Science.gov (United States)

    Li, Yusheng; Matej, Samuel; Metzler, Scott D

    2014-12-01

    Spatial resolution in positron emission tomography (PET) is still a limiting factor in many imaging applications. To improve the spatial resolution for an existing scanner with fixed crystal sizes, mechanical movements such as scanner wobbling and object shifting have been considered for PET systems. Multiple acquisitions from different positions can provide complementary information and increased spatial sampling. The objective of this paper is to explore an efficient and useful reconstruction framework to reconstruct super-resolution images from super-sampled low-resolution data sets. The authors introduce a super-sampling data acquisition model based on the physical processes with tomographic, downsampling, and shifting matrices as its building blocks. Based on the model, we extend the MLEM and Landweber algorithms to reconstruct images from super-sampled data sets. The authors also derive a backprojection-filtration-like (BPF-like) method for the super-sampling reconstruction. Furthermore, they explore variant methods for super-sampling reconstructions: the separate super-sampling resolution-modeling reconstruction and the reconstruction without downsampling to further improve image quality at the cost of more computation. The authors use simulated reconstruction of a resolution phantom to evaluate the three types of algorithms with different super-samplings at different count levels. Contrast recovery coefficient (CRC) versus background variability, as an image-quality metric, is calculated at each iteration for all reconstructions. The authors observe that all three algorithms can significantly and consistently achieve increased CRCs at fixed background variability and reduce background artifacts with super-sampled data sets at the same count levels. For the same super-sampled data sets, the MLEM method achieves better image quality than the Landweber method, which in turn achieves better image quality than the BPF-like method. The authors also demonstrate

  10. Cardiac imaging. Direct diagnosis in radiology

    Energy Technology Data Exchange (ETDEWEB)

    Claussen, C.D.; Miller, S.; Fenchel, M.; Kramer, U. [Tuebingen Univ. (Germany). Dept. of Diagnostic and Interventional Radiology; Riessen, R. [Tuebingen Univ. (Germany). Dept. of Medicine

    2008-07-01

    Teh book covers chest radiographic findings, echocardiographic findings, PET findings, CT findings, MRI findings and invasive diagnostic procedures within the following chapters: ischemic heart diseases; heart failure; acquired valvular heart diseases, cardiomyopathy; inflammatory heart diseases, hypertension, tumors and other masses; trauma; congenital heart diseases, diseases of the great vessels; and standard views of the heart.

  11. 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.

  12. Colorectal Cancer Liver Metastases: Diagnostic Performance and Prognostic Value of PET/MR Imaging.

    Science.gov (United States)

    Lee, Dong Ho; Lee, Jeong Min; Hur, Bo Yun; Joo, Ijin; Yi, Nam-Joon; Suh, Kyung-Suk; Kang, Keon Wook; Han, Joon Koo

    2016-09-01

    Purpose To evaluate the diagnostic performance of combined positron emission tomography (PET) and magnetic resonace (MR) imaging (hereafter, PET/MR imaging) in the detection of liver metastases and to assess its prognostic value in patients with colorectal cancer liver metastases (CRLMs). Materials and Methods Institutional review board approval was obtained for this retrospective study, with waiver of informed consent. A total of 55 patients with 98 CRLMs who underwent PET/MR imaging and multidetector computed tomography (CT) between January 2013 and June 2014 comprised the study population. Of these patients, 34 underwent hepatic resection, 18 of whom also underwent neoadjuvant chemotherapy (NAC). Two board-certificated radiologists independently assessed the four image sets (ie, multidetector CT, whole-body PET, MR imaging with a liver-specific contrast agent [hereafter, EOB MR imaging], and PET/MR imaging). To compare the diagnostic performance of each imaging modality, jackknife alternative free-response receiver operating characteristic and generalized estimating equations were used. To assess prognostic value, recurrence-free survival of the 18 patients who underwent NAC followed by hepatic resection was analyzed by using the Kaplan-Meier method and log-rank test. Results The reader-averaged figure of merit of PET/MR imaging was significantly higher than that of either multidetector CT (P = .003) or PET (P = .020) in the detection of CRLMs. However, no significant difference was observed between figure of merit for PET/MR imaging and that for EOB MR imaging (P = .231). After NAC, six of the 18 patients had isometabolic CRLMs on PET images, and 12 patients had hypermetabolic CRLMs. The 1-year recurrence-free survival rate was 80% in patients with isometabolic CRLMs and 14% in patients with hypermetabolic CRLMs, showing a significant difference (P = .026). Conclusion PET/MR imaging can yield significantly higher diagnostic performance in the detection of CRLMs

  13. Generation of structural MR images from amyloid PET: Application to MR-less quantification.

    Science.gov (United States)

    Choi, Hongyoon; Lee, Dong Soo

    2017-12-07

    Structural magnetic resonance (MR) images concomitantly acquired with PET images can provide crucial anatomical information for precise quantitative analysis. However, in the clinical setting, not all the subjects have corresponding MR. Here, we developed a model to generate structural MR images from amyloid PET using deep generative networks. We applied our model to quantification of cortical amyloid load without structural MR. Methods: We used florbetapir PET and structural MR data of Alzheimer's Disease Neuroimaging Initiative database. The generative network was trained to generate realistic structural MR images from florbetapir PET images. After the training, the model was applied to the quantification of cortical amyloid load. PET images were spatially normalized to the template space using the generated MR and then standardized uptake value ratio (SUVR) of the target regions was measured by predefined regions-of-interests. A real MR-based quantification was used as the gold standard to measure the accuracy of our approach. Other MR-less methods, a normal PET template-based, multi-atlas PET template-based and PET segmentation-based normalization/quantification methods, were also tested. We compared performance of quantification methods using generated MR with that of MR-based and MR-less quantification methods. Results: Generated MR images from florbetapir PET showed visually similar signal patterns to the real MR. The structural similarity index between real and generated MR was 0.91 ± 0.04. Mean absolute error of SUVR of cortical composite regions estimated by the generated MR-based method was 0.04±0.03, which was significantly smaller than other MR-less methods (0.29±0.12 for the normal PET-template, 0.12±0.07 for multiatlas PET-template and 0.08±0.06 for PET segmentation-based methods). Bland-Altman plots revealed that the generated MR-based SUVR quantification was the closest to the SUVR values estimated by the real MR-based method. Conclusion

  14. Incidental Cardiac Findings on Thoracic Imaging.

    LENUS (Irish Health Repository)

    Kok, Hong Kuan

    2013-02-07

    The cardiac structures are well seen on nongated thoracic computed tomography studies in the investigation and follow-up of cardiopulmonary disease. A wide variety of findings can be incidentally picked up on careful evaluation of the pericardium, cardiac chambers, valves, and great vessels. Some of these findings may represent benign variants, whereas others may have more profound clinical importance. Furthermore, the expansion of interventional and surgical practice has led to the development and placement of new cardiac stents, implantable pacemaker devices, and prosthetic valves with which the practicing radiologist should be familiar. We present a collection of common incidental cardiac findings that can be readily identified on thoracic computed tomography studies and briefly discuss their clinical relevance.

  15. 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.

  16. Local respiratory motion correction for PET/CT imaging: Application to lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lamare, F., E-mail: frederic.lamare@chu-bordeaux.fr; Fernandez, P. [INCIA, UMR 5287, University of Bordeaux, Talence F-33400, France and Nuclear Medicine Department, University Hospital, Bordeaux 33000 (France); Fayad, H.; Visvikis, D. [INSERM, UMR1101, LaTIM, Université de Bretagne Occidentale, Brest 29609 (France)

    2015-10-15

    Purpose: Despite multiple methodologies already proposed to correct respiratory motion in the whole PET imaging field of view (FOV), such approaches have not found wide acceptance in clinical routine. An alternative can be the local respiratory motion correction (LRMC) of data corresponding to a given volume of interest (VOI: organ or tumor). Advantages of LRMC include the use of a simple motion model, faster execution times, and organ specific motion correction. The purpose of this study was to evaluate the performance of LMRC using various motion models for oncology (lung lesion) applications. Methods: Both simulated (NURBS based 4D cardiac-torso phantom) and clinical studies (six patients) were used in the evaluation of the proposed LRMC approach. PET data were acquired in list-mode and synchronized with respiration. The implemented approach consists first in defining a VOI on the reconstructed motion average image. Gated PET images of the VOI are subsequently reconstructed using only lines of response passing through the selected VOI and are used in combination with a center of gravity or an affine/elastic registration algorithm to derive the transformation maps corresponding to the respiration effects. Those are finally integrated in the reconstruction process to produce a motion free image over the lesion regions. Results: Although the center of gravity or affine algorithm achieved similar performance for individual lesion motion correction, the elastic model, applied either locally or to the whole FOV, led to an overall superior performance. The spatial tumor location was altered by 89% and 81% for the elastic model applied locally or to the whole FOV, respectively (compared to 44% and 39% for the center of gravity and affine models, respectively). This resulted in similar associated overall tumor volume changes of 84% and 80%, respectively (compared to 75% and 71% for the center of gravity and affine models, respectively). The application of the nonrigid

  17. A First Report on [18F]FPRGD2 PET/CT Imaging in Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Nadia Withofs

    2017-01-01

    Full Text Available An observational study was set up to assess the feasibility of [F18]FPRGD2 PET/CT for imaging patients with multiple myeloma (MM and to compare its detection rate with low dose CT alone and combined [F18]NaF/[F18]FDG PET/CT images. Four patients (2 newly diagnosed patients and 2 with relapsed MM were included and underwent whole-body PET/CT after injection of [F18]FPRGD2. The obtained images were compared with results of low dose CT and already available results of a combined [F18]NaF/[F18]FDG PET/CT. In total, 81 focal lesions (FLs were detected with PET/CT and an underlying bone destruction or fracture was seen in 72 (89% or 8 (10% FLs, respectively. Fewer FLs (54% were detected by [F18]FPRGD2 PET/CT compared to low dose CT (98% or [F18]NaF/[F18]FDG PET/CT (70% and all FLs detected with [F18]FPRGD2 PET were associated with an underlying bone lesion. In one newly diagnosed patient, more [F18]FPRGD2 positive lesions were seen than [F18]NaF/[F18]FDG positive lesions. This study suggests that [F18]FPRGD2 PET/CT might be less useful for the detection of myeloma lesions in patients with advanced disease as all FLs with [F18]FPRGD2 uptake were already detected with CT alone.

  18. Impact of motion compensation and partial volume correction for 18F-NaF PET/CT imaging of coronary plaque

    Science.gov (United States)

    Cal-González, J.; Tsoumpas, C.; Lassen, M. L.; Rasul, S.; Koller, L.; Hacker, M.; Schäfers, K.; Beyer, T.

    2018-01-01

    Recent studies have suggested that 18F-NaF-PET enables visualization and quantification of plaque micro-calcification in the coronary tree. However, PET imaging of plaque calcification in the coronary arteries is challenging because of the respiratory and cardiac motion as well as partial volume effects. The objective of this work is to implement an image reconstruction framework, which incorporates compensation for respiratory as well as cardiac motion (MoCo) and partial volume correction (PVC), for cardiac 18F-NaF PET imaging in PET/CT. We evaluated the effect of MoCo and PVC on the quantification of vulnerable plaques in the coronary arteries. Realistic simulations (Biograph TPTV, Biograph mCT) and phantom acquisitions (Biograph mCT) were used for these evaluations. Different uptake values in the calcified plaques were evaluated in the simulations, while three ‘plaque-type’ lesions of 36, 31 and 18 mm3 were included in the phantom experiments. After validation, the MoCo and PVC methods were applied in four pilot NaF-PET patient studies. In all cases, the MoCo-based image reconstruction was performed using the STIR software. The PVC was obtained from a local projection (LP) method, previously evaluated in preclinical and clinical PET. The results obtained show a significant increase of the measured lesion-to-background ratios (LBR) in the MoCo  +  PVC images. These ratios were further enhanced when using directly the tissue-activities from the LP method, making this approach more suitable for the quantitative evaluation of coronary plaques. When using the LP method on the MoCo images, LBR increased between 200% and 1119% in the simulated data, between 212% and 614% in the phantom experiments and between 46% and 373% in the plaques with positive uptake observed in the pilot patients. In conclusion, we have built and validated a STIR framework incorporating MoCo and PVC for 18F-NaF PET imaging of coronary plaques. First results indicate an improved

  19. 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.

  20. Combined SPECT/CT and PET/CT for breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Paolo [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Larobina, Michele [Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Tommaso De Amicis, 95, Naples I-80145 (Italy); Di Lillo, Francesca [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Del Vecchio, Silvana [Università di Napoli Federico II, Dipartimento di Scienze Biomediche Avanzate, Via Pansini, 5, Naples I-80131 (Italy); Mettivier, Giovanni, E-mail: mettivier@na.infn.it [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy)

    2016-02-11

    In the field of nuclear medicine imaging, breast imaging for cancer diagnosis is still mainly based on 2D imaging techniques. Three-dimensional tomographic imaging with whole-body PET or SPECT scanners, when used for imaging the breast, has performance limits in terms of spatial resolution and sensitivity, which can be overcome only with a dedicated instrumentation. However, only few hybrid imaging systems for PET/CT or SPECT/CT dedicated to the breast have been developed in the last decade, providing complementary functional and anatomical information on normal breast tissue and lesions. These systems are still under development and clinical trials on just few patients have been reported; no commercial dedicated breast PET/CT or SPECT/CT is available. This paper reviews combined dedicated breast PET/CT and SPECT/CT scanners described in the recent literature, with focus on their technological aspects.

  1. Simultaneous functional imaging using fPET and fMRI

    Energy Technology Data Exchange (ETDEWEB)

    Villien, Marjorie [CERMEP (France)

    2015-05-18

    Brain mapping of task-associated changes in metabolism with PET has been accomplished by subtracting scans acquired during two distinct static states. We have demonstrated that PET can provide truly dynamic information on cerebral energy metabolism using constant infusion of FDG and multiple stimuli in a single experiment. We demonstrate here that the functional PET (fPET-FDG) method accomplished simultaneously with fMRI, can enable the first direct comparisons in time, space and magnitude of hemodynamics and oxygen and glucose consumption. The imaging studies were performed on a 3T Tim-Trio MR scanner modified to support an MR-compatible BrainPET insert. Ten healthy subjects were included. The total PET acquisition and infusion time was 90 minutes. We did 3 blocks of right hand fingers tapping for 10 minutes at 30, 50 and 70 minutes after the beginning of the PET acquisition. ASL and BOLD imaging were acquired simultaneously during the motor paradigm. Changes in glucose utilization are easily observed as changes in the TAC slope of the PET data (FDG utilization rate) and in the derivative signal during motor stimuli in the activated voxels. PET and MRI (ASL, and BOLD) activations are largely colocalized but with very different statistical significance and temporal dynamic, especially in the ipsilateral side of the stimuli. This study demonstrated that motor activation can be measured dynamically during a single FDG PET scan. The complementary nature of fPET-FDG to fMRI capitalizes on the emerging technology of hybrid MR-PET scanners. fPET-FDG, combined with quantitative fMRI methods, allow us to simultaneously measure dynamic changes in glucose utilization and hemodynamic, addressing vital questions about neurovascular coupling.

  2. PET and PET/CT imaging for the earliest detection and treatment of colorectal carcinoma

    Directory of Open Access Journals (Sweden)

    Kevin Carter

    2005-10-01

    Full Text Available 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 Deoxyflouro 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.Aproximadamente, 150 000 novos casos de câncer coloretal são diagnosticados, anualmente, em países em desenvolvimento. Destes, 4,6% em homens e 3,2% em mulheres. A triagem de pacientes é essencial na detecção precoce do carcinoma de colon para ajudar na completa ressecção. Infelizmente, os métodos de exame atualmente disponíveis contam com uma baixa adesão dos pacientes. Parte significativa da solução desse problema pode estar no uso de PET e PET/CT. Os autores revisaram e

  3. Towards integration of PET/MR hybrid imaging into radiation therapy treatment planning

    OpenAIRE

    Paulus, Daniel H.; Thorwath, Daniela; Schmidt, Holger; Quick, Harald H.

    2014-01-01

    Purpose: Multimodality imaging has become an important adjunct of state-of-the-art radiation therapy (RT) treatment planning. Recently, simultaneous PET/MR hybrid imaging has become clinically available and may also contribute to target volume delineation and biological individualization in RT planning. For integration of PET/MR hybrid imaging into RT treatment planning, compatible dedicated RT devices are required for accurate patient positioning. In this study, prototype RT positioning d...

  4. Comparison of MR-based attenuation correction and CT-based attenuation correction of whole-body PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo-Garcia, David [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, New York, NY (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA (United States); Sawiak, Stephen J. [University of Cambridge, Wolfson Brain Imaging Centre, Cambridge (United Kingdom); Knesaurek, Karin; Machac, Joseph [Mount Sinai School of Medicine, Division of Nuclear Medicine, Department of Radiology, New York, NY (United States); Narula, Jagat [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Fuster, Valentin [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); The Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid (Spain); Fayad, Zahi A. [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, New York, NY (United States); Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States)

    2014-08-15

    The objective of this study was to evaluate the performance of the built-in MR-based attenuation correction (MRAC) included in the combined whole-body Ingenuity TF PET/MR scanner and compare it to the performance of CT-based attenuation correction (CTAC) as the gold standard. Included in the study were 26 patients who underwent clinical whole-body FDG PET/CT imaging and subsequently PET/MR imaging (mean delay 100 min). Patients were separated into two groups: the alpha group (14 patients) without MR coils during PET/MR imaging and the beta group (12 patients) with MR coils present (neurovascular, spine, cardiac and torso coils). All images were coregistered to the same space (PET/MR). The two PET images from PET/MR reconstructed using MRAC and CTAC were compared by voxel-based and region-based methods (with ten regions of interest, ROIs). Lesions were also compared by an experienced clinician. Body mass index and lung density showed significant differences between the alpha and beta groups. Right and left lung densities were also significantly different within each group. The percentage differences in uptake values using MRAC in relation to those using CTAC were greater in the beta group than in the alpha group (alpha group -0.2 ± 33.6 %, R{sup 2} = 0.98, p < 0.001; beta group 10.31 ± 69.86 %, R{sup 2} = 0.97, p < 0.001). In comparison to CTAC, MRAC led to underestimation of the PET values by less than 10 % on average, although some ROIs and lesions did differ by more (including the spine, lung and heart). The beta group (imaged with coils present) showed increased overall PET quantification as well as increased variability compared to the alpha group (imaged without coils). PET data reconstructed with MRAC and CTAC showed some differences, mostly in relation to air pockets, metallic implants and attenuation differences in large bone areas (such as the pelvis and spine) due to the segmentation limitation of the MRAC method. (orig.)

  5. Evaluation of ¹⁸F-labeled BODIPY dye as potential PET agents for myocardial perfusion imaging.

    Science.gov (United States)

    Liu, Shuanglong; Li, Dan; Shan, Hong; Gabbaï, Francois P; Li, Zibo; Conti, Peter S

    2014-01-01

    Despite the great potential of positron emission tomography/computed tomography (PET/CT) in cardiovascular disease imaging, one of the major limitations is the availability of PET probes with desirable half-lives and reasonable cost. In this report, we hypothesized that lipophilic cationic BODIPY dye could be selectively accumulated in cardiac muscle, possibly for the development of novel PET myocardial perfusion imaging (MPI) probes. A (18)F-labeled BODIPY dye ([(18)F]1) was synthesized efficiently through a fluoride exchange reaction catalyzed by the Lewis acid tin chloride (SnCl₄). The compound was first evaluated by a cellular uptake assay in vitro, followed by biodistribution and microPET imaging studies in vivo. [(18)F]1 was obtained in more than 90% labeling yield, with >98% radiochemical purity. The HEK-293 cellular uptake assay showed that the preferential uptake of [(18)F]1 could be related to the cell membrane potential. The biodistribution data demonstrated high levels of [(18)F]1 accumulation in the heart. In the biodistribution study in mice, the radioactivity uptake in the heart, blood, liver and lung was 3.01 ± 0.44, 0.39 ± 0.09, 0.69 ± 0.07, 1.71 ± 0.27%ID/g, respectively, at 3h post-injection (p.i.). The heart-to-lung and heart-to-liver ratios are 1.76 ± 0.14 and 4.37 ± 0.51 at 3h p.i., respectively. Volume-of-interest analysis of the microPET images correlated well with the biodistribution studies in mice. The heart was clearly visualized in normal rats, with 0.72 ± 0.18, 0.69 ± 0.18, 0.67 ± 0.20 and 0.59 ± 0.17%ID/g uptake at 0.5, 1, 2 and 4h p.i., respectively. (18)F-labeled BODIPY dye showed good heart uptake and heart-to-blood and heart-to-lung contrast. A (18)F-labeled BODIPY dyes may represent a new category of cationic PET agents for myocardial perfusion imaging. © 2013.

  6. [Non-invasive evaluation of the cardiac autonomic nervous system by PET

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    C-11 hydroxy ephedrine, introduced as the first clinically usable norepinephrine analogue, studies employing normal volunteers and patients with various cardiac disorders was found to valuable as a nonadreneric tracer. Simultaneously, animal studies been used to assess its use following ischemic injury in order to define neuronal damage. Current research focuses on the comparison of C-11 hydroxyephedrine with other neurotransmitters such as C-11 epinephrine and C-11 threohydroxyephedrine. Epinephrine is primarily stored in vesicles of the nerve terminal, while threo-hydroxyephedrine is only substrate to uptake I mechanism. Such a combination of radiotracers may allow the dissection of uptake I mechanism as well as vesicular storage. In parallel to the refinement of presynaptic tracers for the sympathetic nervous system, we are developing radiopharmaceuticals to delineate the adrenergic receptors in the heart. The combined evaluation of pre- and postsynaptic nerve function will improve our ability to identify abnormalides. We are currently developing a new radiosynthesis of the hydrophilic adrenergic receptor antagonist C-11 CGP-12177 which has been used by others for the visualization of adrenergic receptors in the heart. We are developing radiopharmaceuticals, for the delineation of presynaptic cholinergic nerve terminals. Derivatives of benzovesamicol have been labeled in our institution and are currently under investigation. The most promising agent is F-18 benzovesamicol (FEBOBV) which allows the visualization of parasympathetic nerve terminals in the canine heart as demonstrated by, preliminary PET data.

  7. [Non-invasive evaluation of the cardiac autonomic nervous system by PET]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    C-11 hydroxy ephedrine, introduced as the first clinically usable norepinephrine analogue, studies employing normal volunteers and patients with various cardiac disorders was found to valuable as a nonadreneric tracer. Simultaneously, animal studies been used to assess its use following ischemic injury in order to define neuronal damage. Current research focuses on the comparison of C-11 hydroxyephedrine with other neurotransmitters such as C-11 epinephrine and C-11 threohydroxyephedrine. Epinephrine is primarily stored in vesicles of the nerve terminal, while threo-hydroxyephedrine is only substrate to uptake I mechanism. Such a combination of radiotracers may allow the dissection of uptake I mechanism as well as vesicular storage. In parallel to the refinement of presynaptic tracers for the sympathetic nervous system, we are developing radiopharmaceuticals to delineate the adrenergic receptors in the heart. The combined evaluation of pre- and postsynaptic nerve function will improve our ability to identify abnormalides. We are currently developing a new radiosynthesis of the hydrophilic adrenergic receptor antagonist C-11 CGP-12177 which has been used by others for the visualization of adrenergic receptors in the heart. We are developing radiopharmaceuticals, for the delineation of presynaptic cholinergic nerve terminals. Derivatives of benzovesamicol have been labeled in our institution and are currently under investigation. The most promising agent is F-18 benzovesamicol (FEBOBV) which allows the visualization of parasympathetic nerve terminals in the canine heart as demonstrated by, preliminary PET data.

  8. Imaging the DNA damage response with PET and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Knight, James C.; Koustoulidou, Sofia; Cornelissen, Bart [University of Oxford, CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, Oxford (United Kingdom)

    2017-06-15

    DNA integrity is constantly challenged by endogenous and exogenous factors that can alter the DNA sequence, leading to mutagenesis, aberrant transcriptional activity, and cytotoxicity. Left unrepaired, damaged DNA can ultimately lead to the development of cancer. To overcome this threat, a series of complex mechanisms collectively known as the DNA damage response (DDR) are able to detect the various types of DNA damage that can occur and stimulate the appropriate repair process. Each DNA damage repair pathway leads to the recruitment, upregulation, or activation of specific proteins within the nucleus, which, in some cases, can represent attractive targets for molecular imaging. Given the well-established involvement of DDR during tumorigenesis and cancer therapy, the ability to monitor these repair processes non-invasively using nuclear imaging techniques may facilitate the earlier detection of cancer and may also assist in monitoring response to DNA damaging treatment. This review article aims to provide an overview of recent efforts to develop PET and SPECT radiotracers for imaging of DNA damage repair proteins. (orig.)

  9. Detection of Atherosclerotic Inflammation by (68)Ga-DOTATATE PET Compared to [(18)F]FDG PET Imaging.

    Science.gov (United States)

    Tarkin, Jason M; Joshi, Francis R; Evans, Nicholas R; Chowdhury, Mohammed M; Figg, Nichola L; Shah, Aarti V; Starks, Lakshi T; Martin-Garrido, Abel; Manavaki, Roido; Yu, Emma; Kuc, Rhoda E; Grassi, Luigi; Kreuzhuber, Roman; Kostadima, Myrto A; Frontini, Mattia; Kirkpatrick, Peter J; Coughlin, Patrick A; Gopalan, Deepa; Fryer, Tim D; Buscombe, John R; Groves, Ashley M; Ouwehand, Willem H; Bennett, Martin R; Warburton, Elizabeth A; Davenport, Anthony P; Rudd, James H F

    2017-04-11

    Inflammation drives atherosclerotic plaque rupture. Although inflammation can be measured using fluorine-18-labeled fluorodeoxyglucose positron emission tomography ([(18)F]FDG PET), [(18)F]FDG lacks cell specificity, and coronary imaging is unreliable because of myocardial spillover. This study tested the efficacy of gallium-68-labeled DOTATATE ((68)Ga-DOTATATE), a somatostatin receptor subtype-2 (SST2)-binding PET tracer, for imaging atherosclerotic inflammation. We confirmed (68)Ga-DOTATATE binding in macrophages and excised carotid plaques. (68)Ga-DOTATATE PET imaging was compared to [(18)F]FDG PET imaging in 42 patients with atherosclerosis. Target SSTR2 gene expression occurred exclusively in "proinflammatory" M1 macrophages, specific (68)Ga-DOTATATE ligand binding to SST2 receptors occurred in CD68-positive macrophage-rich carotid plaque regions, and carotid SSTR2 mRNA was highly correlated with in vivo (68)Ga-DOTATATE PET signals (r = 0.89; 95% confidence interval [CI]: 0.28 to 0.99; p = 0.02). (68)Ga-DOTATATE mean of maximum tissue-to-blood ratios (mTBRmax) correctly identified culprit versus nonculprit arteries in patients with acute coronary syndrome (median difference: 0.69; interquartile range [IQR]: 0.22 to 1.15; p = 0.008) and transient ischemic attack/stroke (median difference: 0.13; IQR: 0.07 to 0.32; p = 0.003). (68)Ga-DOTATATE mTBRmax predicted high-risk coronary computed tomography features (receiver operating characteristics area under the curve [ROC AUC]: 0.86; 95% CI: 0.80 to 0.92; p 68)Ga-DOTATATE PET scans were readable in all patients. We validated (68)Ga-DOTATATE PET as a novel marker of atherosclerotic inflammation and confirmed that (68)Ga-DOTATATE offers superior coronary imaging, excellent macrophage specificity, and better power to discriminate high-risk versus low-risk coronary lesions than [(18)F]FDG. (Vascular Inflammation Imaging Using Somatostatin Receptor Positron Emission Tomography [VISION]; NCT02021188). Copyright

  10. Feasibility of Multiparametric Imaging with PET/MR in Head and Neck Squamous Cell Carcinoma

    DEFF Research Database (Denmark)

    Rasmussen, Jacob H; Nørgaard, Martin; Hansen, Adam E

    2017-01-01

    . CONCLUSION: In multiparametric imaging with the integrated PET/MR scanner, the VOIs from DWI and (18)F-FDG PET were both within the target volume for radiotherapy and overlapped substantially although not completely. No correlation between (18)F-FDG uptake and DWI could be found across patients, but within...

  11. 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...

  12. 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,

  13. Accuracy of rigid CT-FDG-PET image registration of the liver.

    NARCIS (Netherlands)

    Dalen, J.A. van; Vogel, W.V.; Huisman, H.J.; Oyen, W.J.G.; Jager, G.J.; Karssemeijer, N.

    2004-01-01

    Diagnostic and surgical strategies could benefit from accurate localization of liver malignancies via CT-FDG-PET image registration. However, registration uncertainty occurs due to protocol differences in data-acquisition, the limited spatial resolution of positron emission tomography (PET) and the

  14. 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.

  15. Variation of system performance, quality control standards and adherence to international FDG-PET/CT imaging guidelines. A national survey of PET/CT operations in Austria.

    Science.gov (United States)

    Rausch, I; Bergmann, H; Geist, B; Schaffarich, M; Hirtl, A; Hacker, M; Beyer, T

    2014-01-01

    To gather information on clinical operations, quality control (QC) standards and adoption of guidelines for FDG-PET/CT imaging in Austrian PET/CT centres. A written survey composed of 68 questions related to A) PET/CT centre and installation, B) standard protocol parameters for FDG-PET/CT imaging of oncology patients, and C) standard QC procedures was conducted between November and December 2013 among all Austrian PET/CT centres. In addition, a NEMA-NU2 2012 image quality phantom test was performed using standard whole-body imaging settings on all PET/CT systems with a lesion-to-background ratio of 4. Recovery coefficients (RC) were calculated for each lesion and PET/CT system. A) 13 PET/CT systems were installed in 12 nuclear medicine departments at public hospitals. B) Average fasting prior to FDG-PET/CT was 7.6 (4-12) h. All sites measured blood glucose levels while using different cut-off levels (64%: 150 mg/dl). Weight-based activity injection was performed at 83% sites with a mean FDG activity of 4.1 MBq/kg. Average FDG uptake time was 55 (45-75) min. All sites employed CT contrast agents (variation from 1%-95% of the patients). All sites reported SUV-max. C) Frequency of QC tests varied significantly and QC phantom measurements revealed significant differences in RCs. Significant variations in FDG-PET/CT protocol parameters among all Austrian PET/CT users were observed. Subsequently, efforts need to be put in place to further standardize imaging protocols. At a minimum clinical PET/CT operations should ensure compliance with existing guidelines. Further, standardized QC procedures must be followed to improve quantitative accuracy across PET/CT centres.

  16. 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

  17. Test-retest repeatability of myocardial blood flow and infarct size using {sup 11}C-acetate micro-PET imaging in mice

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, Etienne; Renaud, Jennifer M.; McDonald, Matthew; Klein, Ran; DaSilva, Jean N.; Beanlands, Rob S.B.; DeKemp, Robert A. [University of Ottawa Heart Institute, National Cardiac PET Centre, Ottawa, Ontario (Canada)

    2015-09-15

    Global and regional responses of absolute myocardial blood flow index (iMBF) are used as surrogate markers to assess response to therapies in coronary artery disease. In this study, we assessed the test-retest repeatability of iMBF imaging, and the accuracy of infarct sizing in mice using {sup 11}C-acetate PET. {sup 11}C-Acetate cardiac PET images were acquired in healthy controls, endothelial nitric oxide synthase (eNOS) knockout transgenic mice, and mice after myocardial infarction (MI) to estimate global and regional iMBF, and myocardial infarct size compared to {sup 18}F-FDG PET and ex-vivo histology results. Global test-retest iMBF values had good coefficients of repeatability (CR) in healthy mice, eNOS knockout mice and normally perfused regions in MI mice (CR = 1.6, 2.0 and 1.5 mL/min/g, respectively). Infarct size measured on {sup 11}C-acetate iMBF images was also repeatable (CR = 17 %) and showed a good correlation with the infarct sizes found on {sup 18}F-FDG PET and histopathology (r{sup 2} > 0.77; p < 0.05). {sup 11}C-Acetate micro-PET assessment of iMBF and infarct size is repeatable and suitable for serial investigation of coronary artery disease progression and therapy. (orig.)

  18. Evaluating image reconstruction methods for tumor detection performance in whole-body PET oncology imaging

    Science.gov (United States)

    Lartizien, Carole; Kinahan, Paul E.; Comtat, Claude; Lin, Michael; Swensson, Richard G.; Trebossen, Regine; Bendriem, Bernard

    2000-04-01

    This work presents initial results from observer detection performance studies using the same volume visualization software tools that are used in clinical PET oncology imaging. Research into the FORE+OSEM and FORE+AWOSEM statistical image reconstruction methods tailored to whole- body 3D PET oncology imaging have indicated potential improvements in image SNR compared to currently used analytic reconstruction methods (FBP). To assess the resulting impact of these reconstruction methods on the performance of human observers in detecting and localizing tumors, we use a non- Monte Carlo technique to generate multiple statistically accurate realizations of 3D whole-body PET data, based on an extended MCAT phantom and with clinically realistic levels of statistical noise. For each realization, we add a fixed number of randomly located 1 cm diam. lesions whose contrast is varied among pre-calibrated values so that the range of true positive fractions is well sampled. The observer is told the number of tumors and, similar to the AFROC method, asked to localize all of them. The true positive fraction for the three algorithms (FBP, FORE+OSEM, FORE+AWOSEM) as a function of lesion contrast is calculated, although other protocols could be compared. A confidence level for each tumor is also recorded for incorporation into later AFROC analysis.

  19. Nonlinear PET parametric image reconstruction with MRI information using kernel method

    Science.gov (United States)

    Gong, Kuang; Wang, Guobao; Chen, Kevin T.; Catana, Ciprian; Qi, Jinyi

    2017-03-01

    Positron Emission Tomography (PET) is a functional imaging modality widely used in oncology, cardiology, and neurology. It is highly sensitive, but suffers from relatively poor spatial resolution, as compared with anatomical imaging modalities, such as magnetic resonance imaging (MRI). With the recent development of combined PET/MR systems, we can improve the PET image quality by incorporating MR information. Previously we have used kernel learning to embed MR information in static PET reconstruction and direct Patlak reconstruction. Here we extend this method to direct reconstruction of nonlinear parameters in a compartment model by using the alternating direction of multiplier method (ADMM) algorithm. Simulation studies show that the proposed method can produce superior parametric images compared with existing methods.

  20. 68Ga-DOTATATE PET/CT Can Be an Alternative Imaging Method in Insulinoma Patients.

    Science.gov (United States)

    Tuzcu, Sadiye Altun; Pekkolay, Zafer; Kılınç, Faruk; Tuzcu, Alpaslan Kemal

    2017-09-01

    Insulinomas are the most common cause of hypoglycemia, resulting from endogenous hyperinsulinism. The diagnosis of insulinoma is established by demonstrating inappropriately high serum insulin concentrations during a spontaneous or induced episode of hypoglycemia. Most insulinomas are islet-cell tumors. They are often small (<2 cm), benign, and difficult to localize with current imaging techniques. Insulinomas can be detected using either noninvasive procedures (e.g., transabdominal ultrasonography, spiral CT, MRI, 111In-pentetreotide imaging, and 18F-l-dihydroxyphenylalanine PET) or invasive procedures (e.g., endoscopic ultrasonography) or a selective arterial calcium stimulation test with hepatic venous sampling. Methods: We performed 68Ga-DOTATATE PET/CT on 3 patients with insulinoma. Results: All patients' insulinomas were shown clearly with 68Ga-DOTATATE PET/CT. Conclusion:68Ga-DOTATATE PET/CT imaging may be a useful noninvasive imaging technique to localize insulinomas preoperatively. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  1. An Annotated Dataset of 14 Cardiac MR Images

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille

    2002-01-01

    This note describes a dataset consisting of 14 annotated cardiac MR images. Points of correspondence are placed on each image at the left ventricle (LV). As such, the dataset can be readily used for building statistical models of shape. Further, format specifications and terms of use are given....

  2. TU-AB-BRA-06: Texture Feature Reproducibility Between PET/CT and PET/MR Imaging Modalities

    Energy Technology Data Exchange (ETDEWEB)

    Galavis, P; Friedman, K; Chandarana, H; Jackson, K [NYU Langone Medical Center, New York, NY (United States)

    2015-06-15

    Purpose: Radiomics involves the extraction of texture features from different imaging modalities with the purpose of developing models to predict patient treatment outcomes. The purpose of this study is to investigate texture feature reproducibility across [18F]FDG PET/CT and [18F]FDG PET/MR imaging in patients with primary malignancies. Methods: Twenty five prospective patients with solid tumors underwent clinical [18F]FDG PET/CT scan followed by [18F]FDG PET/MR scans. In all patients the lesions were identified using nuclear medicine reports. The images were co-registered and segmented using an in-house auto-segmentation method. Fifty features, based on the intensity histogram, second and high order matrices, were extracted from the segmented regions from both image data sets. One-way random-effects ANOVA model of the intra-class correlation coefficient (ICC) was used to establish texture feature correlations between both data sets. Results: Fifty features were classified based on their ICC values, which were found in the range from 0.1 to 0.86, in three categories: high, intermediate, and low. Ten features extracted from second and high-order matrices showed large ICC ≥ 0.70. Seventeen features presented intermediate 0.5 ≤ ICC ≤ 0.65 and the remaining twenty three presented low ICC ≤ 0.45. Conclusion: Features with large ICC values could be reliable candidates for quantification as they lead to similar results from both imaging modalities. Features with small ICC indicates a lack of correlation. Therefore, the use of these features as a quantitative measure will lead to different assessments of the same lesion depending on the imaging modality from where they are extracted. This study shows the importance of the need for further investigation and standardization of features across multiple imaging modalities.

  3. Impact of Time-of-Flight PET on Quantification Errors in MR Imaging-Based Attenuation Correction

    NARCIS (Netherlands)

    Mehranian, Abolfazl; Zaidi, Habib

    Time-of-flight (TOF) PET/MR imaging is an emerging imaging technology with great capabilities offered by TOF to improve image quality and lesion detectability. We assessed, for the first time, the impact of TOF image reconstruction on PET quantification errors induced by MR imaging based attenuation

  4. In vivo amyloid imaging with PET in frontotemporal dementia

    Energy Technology Data Exchange (ETDEWEB)

    Engler, Henry [Uruguay University Hospital of Clinics and Faculty of Science, Department of Nuclear Medicine, Montevideo (Uruguay); Uppsala University Hospital, Department of Nuclear Medicine, Uppsala (Sweden); Uppsala University, Department of Medical Sciences, Uppsala (Sweden); GE Healthcare, Uppsala Imanet, Uppsala (Sweden); Santillo, Alexander F.; Lindau, Maria; Lannfelt, Lars; Kilander, Lena [Uppsala University, Department of Public Health and Caring Sciences/Geriatrics, Uppsala (Sweden); Wang, Shu Xia [Guangdong Provincial People' s Hospital, Weilun PET Centre, Guangzhou (China); Savitcheva, Irina [Uppsala University Hospital, Department of Nuclear Medicine, Uppsala (Sweden); Nordberg, Agneta [Karolinska Institute, Division of Molecular Neuropharmacology, Stockholm (Sweden); Karolinska University Hospital Huddinge, Department of Geriatric Medicine, Stockholm (Sweden); Laangstroem, Bengt [GE Healthcare, Uppsala Imanet, Uppsala (Sweden); Uppsala University, Departments of Biochemistry and Organic Chemistry, Uppsala (Sweden)

    2008-01-15

    N-methyl[11C]2-(4'methylaminophenyl)-6-hydroxy-benzothiazole (PIB) is a positron emission tomography (PET) tracer with amyloid binding properties which allows in vivo measurement of cerebral amyloid load in Alzheimer's disease (AD). Frontotemporal dementia (FTD) is a syndrome that can be clinically difficult to distinguish from AD, but in FTD amyloid deposition is not a characteristic pathological finding. The aim of this study is to investigate PIB retention in FTD. Ten patients with the diagnosis of FTD participated. The diagnosis was based on clinical and neuropsychological examination, computed tomography or magnetic resonance imaging scan, and PET with 18Fluoro-2-deoxy-d-glucose (FDG). The PIB retention, measured in regions of interest, was normalised to a reference region (cerebellum). The results were compared with PIB retention data previously obtained from 17 AD patients with positive PIB retention and eight healthy controls (HC) with negative PIB retention. Statistical analysis was performed with a students t-test with significance level set to 0.00625 after Bonferroni correction. Eight FTD patients showed significantly lower PIB retention compared to AD in frontal (p < 0.0001), parietal (p < 0.0001), temporal (p = 0.0001), and occipital (p = 0.0003) cortices as well as in putamina (p < 0.0001). The PIB uptake in these FTD patients did not differ significantly from the HC in any region. However, two of the 10 FTD patients showed PIB retention similar to AD patients. The majority of FTD patients displayed no PIB retention. Thus, PIB could potentially aid in differentiating between FTD and AD. (orig.)

  5. A perspective on the future role of brain pet imaging in exercise science.

    Science.gov (United States)

    Boecker, Henning; Drzezga, Alexander

    2016-05-01

    Positron Emission Tomography (PET) bears a unique potential for examining the effects of physical exercise (acute or chronic) within the central nervous system in vivo, including cerebral metabolism, neuroreceptor occupancy, and neurotransmission. However, application of Neuro-PET in human exercise science is as yet surprisingly sparse. To date the field has been dominated by non-invasive neuroelectrical techniques (EEG, MEG) and structural/functional magnetic resonance imaging (sMRI/fMRI). Despite PET having certain inherent disadvantages, in particular radiation exposure and high costs limiting applicability at large scale, certain research questions in human exercise science can exclusively be addressed with PET: The "metabolic trapping" properties of (18)F-FDG PET as the most commonly used PET-tracer allow examining the neuronal mechanisms underlying various forms of acute exercise in a rather unconstrained manner, i.e. under realistic training scenarios outside the scanner environment. Beyond acute effects, (18)F-FDG PET measurements under resting conditions have a strong prospective for unraveling the influence of regular physical activity on neuronal integrity and potentially neuroprotective mechanisms in vivo, which is of special interest for aging and dementia research. Quantification of cerebral glucose metabolism may allow determining the metabolic effects of exercise interventions in the entire human brain and relating the regional cerebral rate of glucose metabolism (rCMRglc) with behavioral, neuropsychological, and physiological measures. Apart from FDG-PET, particularly interesting applications comprise PET ligand studies that focus on dopaminergic and opioidergic neurotransmission, both key transmitter systems for exercise-related psychophysiological effects, including mood changes, reward processing, antinociception, and in its most extreme form 'exercise dependence'. PET ligand displacement approaches even allow quantifying specific endogenous

  6. 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.)

  7. Resolution improvement of brain PET images using prior information from MRI: clinical application on refractory epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Silva-Rodríguez, Jesus [Instituto de Investigaciones Sanitarias (IDIS), Santiago de Compostela (Spain); Tsoumpas, Charalampos [University of Leeds, Leeds (United Kingdom); Aguiar, Pablo; Cortes, Julia [Nuclear Medicine Department, University Hospital (CHUS), Santiago de Compostela (Spain); Urdaneta, Jesus Lopez [Instituto de Investigaciones Sanitarias (IDIS), Santiago de Compostela (Spain)

    2015-05-18

    An important counterpart of clinical Positron Emission Tomography (PET) for early diagnosis of neurological diseases is its low resolution. This is particularly important when evaluating diseases related to small hypometabolisms such as epilepsy. The last years, new hybrid systems combining PET with Magnetic Resonance (MR) has been increasingly used for several different clinical applications. One of the advantages of MR is the production of high spatial resolution images and a potential application of PET-MR imaging is the improvement of PET resolution using MR information. A potential advantage of resolution recovery of PET images is the enhancement of contrast delivering at the same time better detectability of small lesions or hypometabolic areas and more accurate quantification over these areas. Recently, Shidahara et al (2009) proposed a new method using wavelet transforms in order to produce PET images with higher resolution. We optimised Shidahara’s method (SFS-RR) to take into account possible shortcomings on the particular clinical datasets, and applied it to a group of patients diagnosed with refractory epilepsy. FDG-PET and MRI images were acquired sequentially and then co-registered using software tools. A complete evaluation of the PET/MR images was performed before and after the correction, including different parameters related with PET quantification, such as atlas-based metabolism asymmetry coefficients and Statistical Parametric Mapping results comparing to a database of 87 healthy subjects. Furthermore, an experienced physician analyzed the results of non-corrected and corrected images in order to evaluate improvements of detectability on a visual inspection. Clinical outcome was used as a gold standard. SFS-RR demonstrated to have a positive impact on clinical diagnosis of small hypometabolisms. New lesions were detected providing additional clinically relevant information on the visual inspection. SPM sensitivity for the detection of small

  8. 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.

  9. [The Quality Assurance (QA) and the Quality Control (QC) of Positron Emission Tomography (PET) Image].

    Science.gov (United States)

    Iimori, Takashi

    2015-01-01

    Positron emission tomography (PET) is widely used for image diagnostics; making judgments for early diagnostics, differential diagnostics, staging and treatment effect. As for undertaking the large clinical trial and the multicenter study using several diagnostics, the quantitative standardization of PET images is important. We should maintain the safety and the accuracy of daily clinical images. Moreover, we have to develop a safety treatment manual for instruments, apparatus and radiopharmaceuticals in order to produce PET studies of the highest diagnostic accuracy. In addition, daily quality assurance (QA) and quality control (QC) are very important in order to achieve efficiency and safety of PET studies. The importance of the QA and the QC have been recognized from the view of clinical incident protection points. PET will become more advanced in the future, and therefore the QA and the QC for PET images will continue to important in our work. In the view-risk management, we should reaffirm the importance of both QA and QC. Furthermore, we underline the importance of the constant management system and organization in order to gain the quality enhancement of PET imaging.

  10. Characterisation of peripartum cardiomyopathy by cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mouquet, Frederic; Groote, Pascal de; Bouabdallaoui, Nadia; Dagorn, Joel; Lamblin, Nicolas; Bauters, Christophe [Pole de Cardiologie et Maladies Vasculaires, CHRU Lille et Universite Lille 2, Lille Cedex (France); Lions, Christophe; Willoteaux, Serge; Beregi, Jean Paul [Radiologie et Imagerie Cardiovasculaire, CHRU Lille et Universite Lille 2, Lille Cedex (France); Deruelle, Philippe [Gynecologie-Maternite, CHRU Lille et Universite Lille 2, Lille Cedex (France)

    2008-12-15

    Peripartum cardiomyopathy (PPCM) is a rare cause of heart failure. Only half of the patients recover normal cardiac function. We assessed the usefulness of magnetic resonance imaging (MRI) and late enhancement imaging to detect myocardial fibrosis in order to predict cardiac function recovery in patients with peripartum cardiomyopathy. Among a consecutive series of 1,037 patients referred for heart failure treatment or prognostic evaluation between 1999 and 2006, eight women had confirmed PPCM. They all underwent echocardiography and cardiac MRI for assessment of left ventricular anatomy, systolic function and detection of myocardial fibrosis through late enhancement imaging. Mean ({+-} SD) baseline left ventricular ejection fraction (LVEF) was 28 {+-} 4%. After a follow-up of 50 {+-} 9 months, half the patients recovered normal cardiac function (LVEF = 58 {+-} 4%) and four did not (LVEF = 35 {+-} 6%). None of the eight patients exhibited abnormal myocardial late enhancement. No difference in MRI characteristics was observed between the two groups. Patients with PPCM do not exhibit a specific cardiac MRI pattern and particularly no myocardial late enhancement. It suggests that myocardial fibrosis does not play a major role in the limitation of cardiac function recovery after PPCM. (orig.)

  11. 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.

  12. PET/MR - a rapidly growing technique of imaging in oncology and neurology.

    Science.gov (United States)

    Sałyga, Alicja; Guzikowska-Ruszkowska, Izabela; Czepczyński, Rafał; Ruchała, Marek

    2016-01-01

    The combination of positron emission tomography (PET) and magnetic resonance (MR) has become a subject of interest for researchers in the recent several years. Positron emission tomography in combination with magnetic resonance (PET/MR) is the most recent imaging technique classified in the so called hybrid systems category. This review briefly discusses the development history of PET/MR scanners, the principle of their operation, of tandem systems, as well as fully integrated devices. Further, it summarizes recent reports on the application of PET/MR scans and their possible future role in oncological and non-oncological diagnostics. Recent reports regarding the application of PET/MR scanners show huge potential of simultaneously received images, which exceed the advantages of either of those scans used separately. However, the results so far remain uncertain and require further investigations, especially in terms of clinical studies, not only for scientific purposes.

  13. PET/MR imaging of head/neck in the presence of dental implants

    DEFF Research Database (Denmark)

    Ladefoged, Claes; Beyer, Thomas; Keller, Sune

    2013-01-01

    semi-automatically filled with soft tissue (Soft). Following MR-AC, both PET emission images were reconstructed on 344x344 matrices using AW-OSEM (3iter, 21sub, 4mm Gauss). We report the volume of the inpainted area and the relative difference (Δ%) of PET(/MR)Soft to PET(/MR)DWFS for reference regions...... in the inpainted region, tongue and cerebellum. Furthermore, PET ratio images are computed for visual inspection. Results: The mean volume of implant-induced signal voids was (232±68) mL (min: 152mL, max: 348mL). The relative difference in mean SUV following inpainting as part of MR-AC (PET(/MR)Soft) was (217...... this bias may markedly affect regions used commonly as reference for kinetic modeling. Artifacts and bias can be corrected to a first degree by inpainting with soft tissue prior to MR-AC....

  14. 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.

  15. Metabolic imaging of patients with intracranial tumors: H-1 MR spectroscopic imaging and PET.

    Science.gov (United States)

    Luyten, P R; Marien, A J; Heindel, W; van Gerwen, P H; Herholz, K; den Hollander, J A; Friedmann, G; Heiss, W D

    1990-09-01

    Hydrogen-1 magnetic resonance (MR) spectroscopic images of patients with intracranial tumors were obtained. Metabolite maps of N-acetyl aspartate, choline, lactate, and creatine concentrations were reconstructed with a nominal spatial resolution of 7 mm and a section thickness of 25 mm. The metabolite maps showed variations in metabolite concentrations across the tumor. In one patient, it was observed that choline concentration was increased in one part of the tumor but decreased in another part. In another patient, the concentration of N-acetyl aspartate was extremely low in one part of the tumor but only slightly increased in another part of the tumor. Lactate was observed in all patients. In one patient, a combined measurement made with positron emission tomography (PET) and MR spectroscopic imaging was performed. This demonstrated that increased lactate concentration measured with H-1 MR spectroscopic imaging corresponded topographically with increased glucose uptake measured with fluorine-18 fluoro-2-deoxyglucose PET. Combined MR spectroscopic and PET measurements provide an opportunity to investigate, in greater detail than before, glucose uptake and catabolism by intracranial tumors.

  16. Clinical evaluation of PET image reconstruction using a spatial resolution model

    DEFF Research Database (Denmark)

    Andersen, Flemming Littrup; Klausen, Thomas Levin; Loft, Annika

    2013-01-01

    reconstructed on 336×336-matrices using: (R1) standard AW-OSEM (4 iter, 8 subsets, 4mm Gaussian) and (R2) AW-OSEM with PSF (3 iter, 21 subsets, 2mm). Blinded and randomised reading of R1- and R2-PET images was performed. Individual lesions were located and counted independently on both sets of images......PURPOSE: PET image resolution is variable across the measured field-of-view and described by the point spread function (PSF). When accounting for the PSF during PET image reconstruction image resolution is improved and partial volume effects are reduced. Here, we evaluate the effect of PSF......-based reconstruction on lesion quantification in routine clinical whole-body (WB) PET/CT imaging. MATERIALS AND METHODS: 41 oncology patients were referred for a WB-PET/CT examination (Biograph 40 TruePoint). Emission data were acquired at 2.5min/bed at 1hpi of 400 MBq [18F]-FDG. Attenuation-corrected PET images were...

  17. Development of new peripheral benzodiazepine receptor ligands for SPECT and PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Katsifis, A.; Fookes, C.; Pham, T.; Holmes, T.; Mattner, F.; Berghoffer, P.; Gregoire, M.C.; Loc' h, C.; Greguric, I. [Radiopharmaceuticas Research Institute, ANSTO, Menai, N.S.W. Sydney (Australia); Thominiaux, C.; Boutin, H.; Chauveau, F.; Gregoire, M.C.; Hantraye, Ph.; Tavitain, B.; Dolle, F. [Service Hospitalier Frederic Joliot, CEA/DSV, 91 - Orsay (France); Arlicot, N.; Chalon, S.; Guilloteau, D. [Universite Francois Rabelais, Inserm U619, 37 - Tours (France)

    2008-02-15

    This study aims to demonstrate that a number of radiolabelled ({sup 123}I,{sup 11}C, {sup 18}F) imidazo pyridines, imidazo pyridazines and indolglyoxylamides can be developed as potential tracers for SPECT and PET imaging. (N.C.)

  18. Integration of PET/MR Hybrid Imaging into Radiation Therapy Treatment.

    Science.gov (United States)

    Zhu, Tong; Das, Shiva; Wong, Terence Z

    2017-05-01

    Hybrid PET/MR imaging is in early development for treatment planning. This article briefly reviews research and clinical applications of PET/MR imaging in radiation oncology. With improvements in workflow, more specific tracers, and fast and robust acquisition protocols, PET/MR imaging will play an increasingly important role in better target delineation for treatment planning and have clear advantages in the evaluation of tumor response and in a better understanding of tumor heterogeneity. With advances in treatment delivery and the potential of integrating PET/MR imaging with research on radiomics for radiation oncology, quantitative and physiologic information could lead to more precise and personalized RT. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. 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.

  20. A recovery coefficient method for partial volume correction of PET images

    National Research Council Canada - National Science Library

    Srinivas, Shyam M; Dhurairaj, Thiruvenkatasamy; Basu, Sandip; Bural, Gonca; Surti, Suleman; Alavi, Abass

    2009-01-01

    Correction of the "partial volume effect" has been an area of great interest in the recent times in quantitative PET imaging and has been mainly studied with count recovery models based upon phantoms...

  1. Sensitivity study of voxel-based PET image comparison to image registration algorithms.

    Science.gov (United States)

    Yip, Stephen; Chen, Aileen B; Aerts, Hugo J W L; Berbeco, Ross

    2014-11-01

    Accurate deformable registration is essential for voxel-based comparison of sequential positron emission tomography (PET) images for proper adaptation of treatment plan and treatment response assessment. The comparison may be sensitive to the method of deformable registration as the optimal algorithm is unknown. This study investigated the impact of registration algorithm choice on therapy response evaluation. Sixteen patients with 20 lung tumors underwent a pre- and post-treatment computed tomography (CT) and 4D FDG-PET scans before and after chemoradiotherapy. All CT images were coregistered using a rigid and ten deformable registration algorithms. The resulting transformations were then applied to the respective PET images. Moreover, the tumor region defined by a physician on the registered PET images was classified into progressor, stable-disease, and responder subvolumes. Particularly, voxels with standardized uptake value (SUV) decreases >30% were classified as responder, while voxels with SUV increases >30% were progressor. All other voxels were considered stable-disease. The agreement of the subvolumes resulting from difference registration algorithms was assessed by Dice similarity index (DSI). Coefficient of variation (CV) was computed to assess variability of DSI between individual tumors. Root mean square difference (RMSrigid) of the rigidly registered CT images was used to measure the degree of tumor deformation. RMSrigid and DSI were correlated by Spearman correlation coefficient (R) to investigate the effect of tumor deformation on DSI. Median DSIrigid was found to be 72%, 66%, and 80%, for progressor, stable-disease, and responder, respectively. Median DSIdeformable was 63%-84%, 65%-81%, and 82%-89%. Variability of DSI was substantial and similar for both rigid and deformable algorithms with CV > 10% for all subvolumes. Tumor deformation had moderate to significant impact on DSI for progressor subvolume with Rrigid = - 0.60 (p = 0.01) and

  2. Comparison of 18F-FDG-PET/CT and 18F-FDG-PET/MR imaging in oncology: a systematic review.

    Science.gov (United States)

    Singnurkar, Amit; Poon, Raymond; Metser, Ur

    2017-06-01

    The aim of this study was to systematically review the literature to evaluate the clinical performance of integrated 18F-FDG PET/MR as compared with 18F-FDG PET/CT in oncologic imaging. The literature was searched using MEDLINE and EMBASE via OVID. Studies comparing the diagnostic accuracy of integrated 18F-FDG PET/MR and 18F-FDG PET/CT in the diagnosis, staging/restaging, assessment of treatment response, or evaluation of metastasis in patients with suspected or diagnosed cancers were deemed eligible for inclusion. Risk of bias and applicability concerns were assessed using the QUADAS-2 tool. Twenty studies met the inclusion criteria. The overall quality of the studies was rated favorably with bias or applicability concerns in a few studies. Our review suggests that 18F-FDG PET/MR performs comparably to 18F-FDG PET/CT in the detection of local lymph node and distant metastases and superiorly in determining the local extent of tumor. SUV obtained from 18F-FDG PET/MR correlated highly with those obtained from 18F-FDG PET/CT. Based on early evidence, 18F-FDG PET/MR is comparable to 18F-FDG PET/CT in the clinical scenarios examined in this review. The potential for interchangeability of 18F-FDG PET/MR with 18F-FDG PET/CT will vary by indication and the body site that is being imaged, with PET scanners integrated with MRI predicted to provide greater detail in the evaluation of local tumor extent, where 18F-FDG PET/CT can be limited.

  3. Transcranial optical vascular imaging (TOVI) during cardiac arrest (Conference Presentation)

    Science.gov (United States)

    Kalchenko, Vyacheslav; Kuznetsov, Yuri; Meglinski, Igor; Harmelin, Alon

    2017-03-01

    Based on the recent studies the prognosis of patients after cardiac arrest (CA) remains poor. Thus it is extremely important to understand fine mechanisms related to the influence of CA on the brain and Cerebral Blood Flow (CBF) during and after cardiac arrest. Recently our group introduced Transcranial Optical Vascular Imaging (TOVI) approach that combines laser speckle and dynamic fluorescent imaging. TOVI proved to be useful during various preclinical brain research applications. For example it allows imaging of brain blood vessels of a mouse in vivo through the intact cranium. Herein for the first time we present the use of TOVI during cardiac arrest. TOVI possibly could be a useful tool for preclinical studies of CBF during and after CA.

  4. Evolution of bombesin conjugates for targeted PET imaging of tumors.

    Directory of Open Access Journals (Sweden)

    Hanwen Zhang

    Full Text Available Bombesin receptors are under intense investigation as molecular targets since they are overexpressed in several prevalent solid tumors. We rationally designed and synthesized a series of modified bombesin (BN peptide analogs to study the influence of charge and spacers at the N-terminus, as well as amino acid substitutions, on both receptor binding affinity and pharmacokinetics. This enabled development of a novel (64/67Cu-labeled BN peptide for PET imaging and targeted radiotherapy of BN receptor-positive tumors. Our results show that N-terminally positively charged peptide ligands had significantly higher affinity to human gastrin releasing peptide receptor (GRPr than negatively charged or uncharged ligands (IC(50: 3.2±0.5 vs 26.3±3.5 vs 41.5±2.5 nM. The replacement of Nle(14 by Met, and deletion of D-Tyr(6, further resulted in 8-fold higher affinity. Contrary to significant changes to human GRPr binding, modifications at the N-terminal and at the 6(th, 11(th, and 14(th position of BN induced only slight influences on affinity to mouse GRPr. [Cu(II]-CPTA-[βAla(11] BN(7-14 ([Cu(II]-BZH7 showed the highest internalization rate into PC-3 cells with relatively slow efflux because of its subnanomolar affinity to GRPr. Interestingly, [(64/67Cu]-BZH7 also displayed similar affinities to the other 2 human BN receptor subtypes. In vivo studies showed that [(64/67Cu]-BZH7 had a high accumulation in PC-3 xenografts and allowed for clear-cut visualization of the tumor in PET imaging. In addition, a CPTA-glycine derivative, forming a hippurane-type spacer, enhanced kidney clearance of the radiotracer. These data indicate that the species variation of BN receptor plays an important role in screening radiolabeled BN. As well, the positive charge from the metallated complex at the N-terminal significantly increases affinity to human GRPr. Application of these observations enabled the novel ligand [(64/67Cu]-BZH7 to clearly visualize PC-3 tumors in vivo

  5. [18F]DPA 714 PET Imaging Reveals Global Neuroinflammation in Zika Virus Infected Mice

    Science.gov (United States)

    2017-09-12

    with neurotropic viruses and the evaluation of therapeutics being developed for treatment of infectious diseases. Keywords: Zika virus , Animal...18F]DPA-714 PET Imaging Reveals Global Neuroinflammation in Zika Virus - Infected Mice Kyle Kuszpit1†, Bradley S. Hollidge2†, Xiankun Zeng3, Robert...Running Head: PET Imaging of Zika Virus -Induced Neuroinflammation Manuscript Category: Article Affiliations: 1Molecular and Translational

  6. Pretargeted PET Imaging of trans-Cyclooctene-Modified Porous Silicon Nanoparticles

    OpenAIRE

    Keinänen, Outi; Mäkilä, Ermei M.; Lindgren, Rici; Virtanen, Helena; Liljenbäck, Heidi; Oikonen, Vesa; Sarparanta, Mirkka; Molthoff, Carla; Windhorst, Albert D.; Roivainen, Anne; Salonen, Jarno J.; Airaksinen, Anu J.

    2017-01-01

    Pretargeted positron emission tomography (PET) imaging based on bioorthogonal chemical reactions has proven its potential in immunoimaging. It may also have great potential in nanotheranostic applications. Here, we report the first successful pretargeted PET imaging of trans-cyclooctene-modified mesoporous silicon nanoparticles, using 18F-labeled tetrazine as a tracer. The inverse electron-demand Diels?Alder cycloaddition (IEDDA) reaction was fast, resulting in high radioactivity accumulation...

  7. 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...

  8. MRI-guided brain PET image filtering and partial volume correction

    Science.gov (United States)

    Yan, Jianhua; Chu-Shern Lim, Jason; 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 18F-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.

  9. Single photon image from PET with insertable collimator for boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jooyoung; Suh, Tae Suk [Catholic Univ. of Korea, Seoul (Korea, Republic of); Hong, Key Jo [Stanford Univ., Stanford (United States)

    2014-05-15

    Boron neutron capture therapy (BNCT) is a radiation therapy technique for treating deep-seated brain tumors by irradiation with a thermal neutron in which boron-labelled low molecular weight compounds. Once completed, a single photon emission computed tomography (SPECT) scan is conducted to investigate for the region of therapy using an isotope exclusive to SPECT. In the case of an existing PET/SPECT combination system, at least two types of isotopes should be used for each scan with their purposes. Recently, researchers examined the effects of PET/SPECT dual modality on animal imaging systems. They reported that the PET/SPECT combination system was effective for simultaneous achievement of a single event and coincidence. The aim of our proposed system is to confirm the feasibility of extraction of two types of images from one PET module with an insertable collimator for brain tumor treatment during the BNCT. We attempted to acquire the PET and SPECT images simultaneously using only PET without an additional isotope. Single photon images were acquired using an insertable collimator on a PET detector.

  10. Clinical PET/MR Imaging in Dementia and Neuro-Oncology

    DEFF Research Database (Denmark)

    Henriksen, Otto M.; Marner, Lisbeth; Law, Ian

    2016-01-01

    The introduction of hybrid PET/MRI systems allows simultaneous multimodality image acquisition of high technical quality. This technique is well suited for the brain, and particularly in dementia and neuro-oncology. In routine use combinations of well-established MRI sequences and PET tracers...... provide the most optimal and clinically valuable protocols. For dementia the [18F]-fluorodeoxyglucose (FDG) has merit with a simultaneous four sequence MRI protocol of 20 min supported by supplementary statistical reading tools and quantitative measurements of the hippocampal volume. Clinical PET......-oncology under general anesthesia. The clinical value of adding advanced MRI sequences in multiparametric imaging setting, however, is still undocumented....

  11. Thorax: normal and benign pathologic patterns in FDG-PET/CT imaging.

    Science.gov (United States)

    Wachsmann, Jason W; Gerbaudo, Victor H

    2014-04-01

    This article describes the normal patterns of thoracic (18)F-fluorodeoxyglucose (FDG) biodistribution, and expands on the role of FDG-PET/computed tomography (CT) for the evaluation of patients suffering from a spectrum of benign pathologic conditions that affect the chest. The discussion addresses the applications of FDG-PET/CT imaging in a wide variety of chest-related disorders. Familiarity with the normal thoracic biodistribution of FDG, coupled with knowledge of the potential nonmalignant causes of increased FDG uptake in the chest, is essential to minimize the incidence of incorrect interpretation of FDG-PET images in daily clinical practice. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. How we read pediatric PET/CT: indications and strategies for image acquisition, interpretation and reporting.

    Science.gov (United States)

    Colleran, Gabrielle C; Kwatra, Neha; Oberg, Leah; Grant, Frederick D; Drubach, Laura; Callahan, Michael J; MacDougall, Robert D; Fahey, Frederic H; Voss, Stephan D

    2017-11-07

    PET/CT plays an important role in the diagnosis, staging and management of many pediatric malignancies. The techniques for performing PET/CT examinations in children have evolved, with increasing attention focused on reducing patient exposure to ionizing radiation dose whenever possible and minimizing scan duration and sedation times, with a goal toward optimizing the overall patient experience. This review outlines our approach to performing PET/CT, including a discussion of the indications for a PET/CT exam, approaches for optimizing the exam protocol, and a review of different approaches for acquiring the CT portion of the PET/CT exam. Strategies for PACS integration, image display, interpretation and reporting are also provided. Most practices will develop a strategy for performing PET/CT that best meets their respective needs. The purpose of this article is to provide a comprehensive overview for radiologists who are new to pediatric PET/CT, and also to provide experienced PET/CT practitioners with an update on state-of-the art CT techniques that we have incorporated into our protocols and that have enabled us to make considerable improvements to our PET/CT practice.

  13. {sup 18}F-FDG PET/CT diagnosis of unexpected extracardiac septic embolisms in patients with suspected cardiac endocarditis

    Energy Technology Data Exchange (ETDEWEB)

    Bonfiglioli, Rachele; Nanni, Cristina; Morigi, Joshua James; Ambrosini, Valentina; Fanti, Stefano [Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, Nuclear Medicine, Bologna (Italy); Graziosi, Maddalena; Rapezzi, Claudio [Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, Cardiology, Bologna (Italy); Trapani, Filippo; Bartoletti, Michele; Tumietto, Fabio; Viale, Pier Luigi [Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, Infective Diseases, Bologna (Italy); Ferretti, Alice; Rubello, Domenico [Azienda Ospedaliera S. Maria della Misericordia, Nuclear Medicine, Radiology, Neuroradiology, Medical Physics, Rovigo (Italy)

    2013-08-15

    Acute infective endocarditis is a potentially life-threatening disease. Its outcome strongly depends on systemic embolization and extracardiac infections. When present, these conditions usually lead to a more aggressive therapeutic approach. However, the diagnosis of peripheral septic embolism is very challenging. {sup 18}F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT has proven to be accurate for the detection of inflammatory diseases and occult infections. The aim of this study was to assess the added value of {sup 18}F-FDG PET/CT in the detection of extracardiac embolisms in the evaluation of patients with suspected valvular endocarditis (VE). Seventy-one patients with suspected infective endocarditis, enrolled between June 2010 and December 2012, underwent {sup 18}F-FDG PET/CT with the standard procedure on a dedicated PET/CT scanner. Extracardiac findings were subsequently evaluated with other imaging procedures. Of the 71 patients with suspicion of infective endocarditis, we found unexpected extracardiac findings in 17 patients (24 %) without any clinical suspicion. Extracardiac findings were subsequently evaluated with other imaging procedures. PET/CT detected unexpected extra sites of infection in 24 % of cases, leading to changes in therapeutic management in a very relevant percentage of patients. These findings may have important therapeutic implications. (orig.)

  14. 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.

  15. Modern CT and PET/CT imaging of the liver; Moderne CT- und PET/CT-Bildgebung der Leber

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, J.; Heusner, T.A.; Riegger, C.; Reichelt, D.; Kuhlemann, J.; Antoch, G.; Blondin, D. [Medizinische Fakultaet, Heinrich-Heine-Universitaet Duesseldorf, Institut fuer Diagnostische und Interventionelle Radiologie, Duesseldorf (Germany)

    2011-08-15

    Computed tomography (CT) is now widely available and represents an important and rapid method for the diagnostics of acute liver disease, characterization of focal liver lesions, planning of interventional therapy measures and postintervention control. In recent years CT has not become less important despite the increasing value of magnetic resonance imaging (MRI). By the use of different contrast medium phases good characterization of space-occupying lesions can be achieved. For the diagnostics of hepatocellular carcinoma (HCC) a triphasic examination protocol should always be implemented. The introduction of dual energy CT increased the sensitivity of imaging of hypervascularized and hypovascularized liver lesions and by the use of virtual native imaging it has become possible to avoid additional native imaging which reduces the x-ray exposition of patients. Positron emission tomography (PET) has an advantage for imaging in oncology because nearly the complete body of the patient can be screened and this is the main indication for PET/CT (whole-body staging). For purely hepatic problems 18F-fluorodeoxyglucose (FDG)-PET/CT using diagnostic CT data has a higher precision than CT alone but is inferior to MRI. (orig.) [German] Die Computertomographie (CT) ist heute breit verfuegbar und stellt eine wichtige und schnelle Methode zur Diagnostik akuter Lebererkrankungen, der Artdiagnostik fokaler Leberlaesionen und der Planung interventioneller Therapiemassnahmen sowie der postinterventionellen Kontrolle dar. In den letzten Jahren hat die CT trotz des zunehmenden Stellenwerts der Magnetresonanztomographie (MRT) nicht an Bedeutung verloren. Durch den Einsatz unterschiedlicher Kontrastmittelphasen kann meist eine gute Charakterisierung von Raumforderungen erfolgen. Bei der Diagnostik des hepatozellulaeren Karzinoms (HCC) sollte beispielsweise immer ein triphasisches Untersuchungsprotokoll angewendet werden. Mit Einfuehrung der Dual-energy-CT hat die Sensitivitaet in der

  16. Performance of a PET Insert for High Resolution Small Animal PET/MR Imaging at 7T.

    Science.gov (United States)

    Stortz, Greg; Thiessen, Jonathan D; Bishop, Daryl; Khan, Muhammad S; Kozlowski, Piotr; Retière, Fabrice; Schellenberg, Graham; Shams, Ehsan; Zhang, Xuezhu; Thompson, Christopher J; Goertzen, Andrew; Sossi, Vesna

    2017-09-14

    We present the characterization of a compact magnetic resonance (MR) compatible positron emission tomography (PET) insert for simultaneous pre-clinical PET/MR imaging. While specifically designed with the strict size constraint to fit inside the 114 mm inner diameter of the BGA-12S gradient coil used in the Bruker 70/20 and 94/20 series of small animal MR imaging (MRI) systems, the insert can be easily installed in any appropriate MRI scanner or used as a stand-alone PET system. Methods: The insert is made from a ring of 16 detector-blocks each made from depth-of-interaction capable dual-layer-offset arrays of cerium-doped lutetium-yttrium oxyorthosilicate crystals read out by silicon photomultiplier (SiPM) arrays. Scintillator crystal arrays are made from 22×10 / 21×9 crystals in the bottom/top layers with 6/4 mm layer thicknesses, arranged with a 1.27 mm pitch, resulting in a useable field of view (FOV) 28 mm long and ~55 mm wide. Results: Spatial resolution ranges from 1.17 to 1.86 mm full-width-at-half-maximum (FWHM) in the radial direction from a radial offset of 0 to 15 mm. With a 300-800 keV energy window, peak sensitivity is 2.2% and noise-equivalent count rate (NECR) from a mouse-sized phantom at 3.7 MBq is 11.1 kcps and peaks at 20.8 kcps at 14.5 MBq. Phantom imaging shows that feature sizes as low as 0.7 mm can be resolved. 18F-fluorodeoxyglucose (18F-FDG) PET/MR images of mouse and rat brains show no signs of inter-modality interference, and can excellently resolve substructures within the brains. Conclusion: Due to excellent spatial resolvability and lack of intermodality interference, this PET insert will serve as a useful tool for pre-clinical PET/MR. Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  17. Advances in cardiac magnetic resonance imaging of congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Driessen, Mieke M.P. [University of Utrecht, University Medical Center Utrecht, Department of Radiology, PO Box 85500, Utrecht (Netherlands); University of Utrecht, University Medical Center Utrecht, Department of Cardiology, PO Box 85500, Utrecht (Netherlands); The Interuniversity Cardiology Institute of the Netherlands (ICIN) - Netherlands Heart Institute, PO Box 19258, Utrecht (Netherlands); Breur, Johannes M.P.J. [Wilhelmina Children' s Hospital, University Medical Center Utrecht, Department of Pediatric Cardiology, PO Box 85500, Utrecht (Netherlands); Budde, Ricardo P.J.; Oorschot, Joep W.M. van; Leiner, Tim [University of Utrecht, University Medical Center Utrecht, Department of Radiology, PO Box 85500, Utrecht (Netherlands); Kimmenade, Roland R.J. van; Sieswerda, Gertjan Tj [University of Utrecht, University Medical Center Utrecht, Department of Cardiology, PO Box 85500, Utrecht (Netherlands); Meijboom, Folkert J. [University of Utrecht, University Medical Center Utrecht, Department of Cardiology, PO Box 85500, Utrecht (Netherlands); Wilhelmina Children' s Hospital, University Medical Center Utrecht, Department of Pediatric Cardiology, PO Box 85500, Utrecht (Netherlands)

    2015-01-01

    Due to advances in cardiac surgery, survival of patients with congenital heart disease has increased considerably during the past decades. Many of these patients require repeated cardiovascular magnetic resonance imaging to assess cardiac anatomy and function. In the past decade, technological advances have enabled faster and more robust cardiovascular magnetic resonance with improved image quality and spatial as well as temporal resolution. This review aims to provide an overview of advances in cardiovascular magnetic resonance hardware and acquisition techniques relevant to both pediatric and adult patients with congenital heart disease and discusses the techniques used to assess function, anatomy, flow and tissue characterization. (orig.)

  18. 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

    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...

  19. Noise contamination from PET blood sampling pump: Effects on structural MRI image quality in simultaneous PET/MR studies.

    Science.gov (United States)

    Bartlett, Elizabeth; DeLorenzo, Christine; Parsey, Ramin; Huang, Chuan

    2018-02-01

    To fully quantify PET imaging outcome measures, a blood sampling pump is often used during the PET acquisition. With simultaneous PET/MR studies, a structural magnetization-prepared rapid gradient-echo (MP-RAGE) may also be acquired while the pump is generating electromagnetic noise. This study investigated whether this noise contamination would be detrimental to the quantification of volume and cortical thickness measures obtained from automated segmentation of the MP-RAGE image. MP-RAGE T1w structural images were acquired for a phantom and 10 healthy volunteers (five female, 27.2 ± 5.1 y old) with the blood sampling pump and without. The white matter signal-to-noise ratio (SNR) was computed for all images. Region-wise cortical thickness and volume were extracted with Freesurfer 5.3.0. The phantom SNR and the white matter human subject SNR was degraded in the MP-RAGE images acquired with the pump (P = 0.005; white matter SNR: 43.9 and 50.8 with the pump and without). Intrasession, region-wise volume and cortical thickness estimates were significantly overestimated with the pump (percent difference: 1.14 ± 2.67% for volume (P = 0.0003) and 0.34 ± 1.59% (P = 0.02) for cortical thickness). Regions with percent differences greater than 5% between pump conditions were those close to tissue-air interfaces: entorhinal, frontal pole, parsorbitalis, temporal pole, and medial orbitofrontal. Synthetically adding Gaussian noise to the without pump MP-RAGE images yielded similar, significant detriments to cortical morphometry compared to without the pump. This study provides evidence that the use of PET blood sampling pumps may generate unstructured, Gaussian-distributed noise in MP-RAGE images that significantly alters the accuracy of Freesurfer-derived volume and cortical thickness estimates. While many cortical regions showed a percent difference of less than 1% with the pump, regions close to tissue-air interfaces, subject to larger susceptibility artifacts

  20. Preoperative Assessment of Pancreatic Cancer with FDG PET/MR Imaging versus FDG PET/CT Plus Contrast-enhanced Multidetector CT: A Prospective Preliminary Study.

    Science.gov (United States)

    Joo, Ijin; Lee, Jeong Min; Lee, Dong Ho; Lee, Eun Sun; Paeng, Jin Chul; Lee, Soo Jin; Jang, Jin-Young; Kim, Sun-Whe; Ryu, Ji Kon; Lee, Kyoung-Bun

    2017-01-01

    Purpose To determine the diagnostic performance of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging in the preoperative assessment of pancreatic cancer in comparison with that of FDG PET/computed tomography (CT) plus contrast material-enhanced multidetector CT. Materials and Methods This prospective study was approved by the institutional review board; written informed consent was obtained. Thirty-seven patients with 39 pancreatic tumors underwent preoperative FDG PET/MR imaging, PET/CT, and contrast-enhanced multidetector CT. The authors measured maximal and mean standardized uptake values (SUVmax and SUVmean, respectively) of pancreatic cancer at PET/MR imaging and PET/CT. Two radiologists independently reviewed the two imaging sets (set 1, PET/MR imaging; set 2, PET/CT plus multidetector CT) to determine tumor resectability according to a five-point scale, N stage (N0 or N positive), and M stage (M0 or M1). With use of clinical-surgical-pathologic findings as the standard of reference (n = 20), diagnostic performances of the two imaging sets were compared by using the McNemar test. Results Both SUVmax and SUVmean of pancreatic tumors showed strong correlations between PET/MR imaging and PET/CT (r = 0.897 and 0.890, respectively; P PET/MR imaging was not significantly different from that of PET/CT plus multidetector CT in the assessment of tumor resectability (area under the receiver operating characteristic curve: 0.891 vs 0.776, respectively, for reviewer 1 [P = .109] and 0.859 vs 0.797 for reviewer 2 [P = .561]), N stage (accuracy: 54% [seven of 13 patients] vs 31% [four of 13 patients]; P = .250 for both reviewers), and M stage (accuracy: 94% [16 of 17 patients] vs 88% [15 of 17 patients] for reviewer 1 [P > .999] and 94% [16 of 17 patients] vs 82% [14 of 17 patients] for reviewer 2 [P = .500]). Conclusion FDG PET/MR imaging showed a diagnostic performance similar to that of PET/CT plus contrast

  1. 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 primary tumors and 22 follow-up) were studied. Patients initially received a clinical exam and endoscopy with direct biopsy. Next patients underwent whole body PET/CT followed by PET/MR of the head/neck region. PET and MRI studies were separately evaluated by two blinded groups (both included one radiologist and one nuclear physician) in order to define the presence or absence of lesions/recurrences. Regions of interest (ROIs) analysis was conducted on the primary lesion at the level of maximum size on metabolic (SUV and MTV), diffusion (ADC) and perfusion (K{sup trans}, V{sub e}, k{sub ep} and iAUC) parameters. Results: PET/MR examinations were successfully performed on all 44 patients. Agreement between the two blinded groups was found in anatomic allocation of lesions by PET/MR (Primary tumors: Cohen's kappa 0.93; Follow-up: Cohen's kappa 0.89). There was a significant correlation between CT-SUV measures and MR (e.g., CT-SUV VOI vs. MR-SUV VOI: ρ = 0.97, p < 0.001 for the entire sample). There was also significant positive correlations between the ROI area, SUV measures, and the metabolic parameters (SUV and MTV) obtained during both PET/CT and PET/MR. A significant negative correlation was observed between ADC and K{sup trans} values in the primary tumors. In addition, a significant negative correlation existed between MR SUV and ADC in

  2. Deep Auto-context Convolutional Neural Networks for Standard-Dose PET Image Estimation from Low-Dose PET/MRI.

    Science.gov (United States)

    Xiang, Lei; Qiao, Yu; Nie, Dong; An, Le; Wang, Qian; Shen, Dinggang

    2017-12-06

    Positron emission tomography (PET) is an essential technique in many clinical applications such as tumor detection and brain disorder diagnosis. In order to obtain high-quality PET images, a standard-dose radioactive tracer is needed, which inevitably causes the risk of radiation exposure damage. For reducing the patient's exposure to radiation and maintaining the high quality of PET images, in this paper, we propose a deep learning architecture to estimate the high-quality standard-dose PET (SPET) image from the combination of the low-quality low-dose PET (LPET) image and the accompanying T1-weighted acquisition from magnetic resonance imaging (MRI). Specifically, we adapt the convolutional neural network (CNN) to account for the two channel inputs of LPET and T1, and directly learn the end-to-end mapping between the inputs and the SPET output. Then, we integrate multiple CNN modules following the auto-context strategy, such that the tentatively estimated SPET of an early CNN can be iteratively refined by subsequent CNNs. Validations on real human brain PET/MRI data show that our proposed method can provide competitive estimation quality of the PET images, compared to the state-of-the-art methods. Meanwhile, our method is highly efficient to test on a new subject, e.g., spending ~2 seconds for estimating an entire SPET image in contrast to ~16 minutes by the state-of-the-art method. The results above demonstrate the potential of our method in real clinical applications.

  3. PET image reconstruction using multi-parametric anato-functional priors.

    Science.gov (United States)

    Mehranian, Abolfazl; Belzunce, Martin A; Niccolini, Flavia; Politis, Marios; Prieto, Claudia; Turkheimer, Federico; Hammers, Alexander; Reader, Andrew J

    2017-07-06

    In this study, we investigate the application of multi-parametric anato-functional (MR-PET) priors for the maximum a posteriori (MAP) reconstruction of brain PET data in order to address the limitations of the conventional anatomical priors in the presence of PET-MR mismatches. In addition to partial volume correction benefits, the suitability of these priors for reconstruction of low-count PET data is also introduced and demonstrated, comparing to standard maximum-likelihood (ML) reconstruction of high-count data. The conventional local Tikhonov and total variation (TV) priors and current state-of-the-art anatomical priors including the Kaipio, non-local Tikhonov prior with Bowsher and Gaussian similarity kernels are investigated and presented in a unified framework. The Gaussian kernels are calculated using both voxel- and patch-based feature vectors. To cope with PET and MR mismatches, the Bowsher and Gaussian priors are extended to multi-parametric priors. In addition, we propose a modified joint Burg entropy prior that by definition exploits all parametric information in the MAP reconstruction of PET data. The performance of the priors was extensively evaluated using 3D simulations and two clinical brain datasets of [ 18 F]florbetaben and [ 18 F]FDG radiotracers. For simulations, several anato-functional mismatches were intentionally introduced between the PET and MR images, and furthermore, for the FDG clinical dataset, two PET-unique active tumours were embedded in the PET data. Our simulation results showed that the joint Burg entropy prior far outperformed the conventional anatomical priors in terms of preserving PET unique lesions, while still reconstructing functional boundaries with corresponding MR boundaries. In addition, the multi-parametric extension of the Gaussian and Bowsher priors led to enhanced preservation of edge and PET unique features and also an improved bias-variance performance. In agreement with the simulation results, the clinical

  4. PET image reconstruction using multi-parametric anato-functional priors

    Science.gov (United States)

    Mehranian, Abolfazl; Belzunce, Martin A.; Niccolini, Flavia; Politis, Marios; Prieto, Claudia; Turkheimer, Federico; Hammers, Alexander; Reader, Andrew J.

    2017-08-01

    In this study, we investigate the application of multi-parametric anato-functional (MR-PET) priors for the maximum a posteriori (MAP) reconstruction of brain PET data in order to address th