Clinical Utility of Amyloid PET Imaging in the Differential Diagnosis of Atypical Dementias and Its Impact on Caregivers.

Science.gov (United States)

Bensaïdane, Mohamed Reda; Beauregard, Jean-Mathieu; Poulin, Stéphane; Buteau, François-Alexandre; Guimond, Jean; Bergeron, David; Verret, Louis; Fortin, Marie-Pierre; Houde, Michèle; Bouchard, Rémi W; Soucy, Jean-Paul; Laforce, Robert

2016-04-18

Recent studies have supported a role for amyloid positron emission tomography (PET) imaging in distinguishing Alzheimer's disease (AD) pathology from other pathological protein accumulations leading to dementia. We investigated the clinical utility of amyloid PET in the differential diagnosis of atypical dementia cases and its impact on caregivers. Using the amyloid tracer 18F-NAV4694, we prospectively scanned 28 patients (mean age 59.3 y, s.d. 5.8; mean MMSE 21.4, s.d. 6.0) with an atypical dementia syndrome. Following a comprehensive diagnostic workup (i.e., history taking, neurological examination, blood tests, neuropsychological evaluation, MRI, and FDG-PET), no certain diagnosis could be arrived at. Amyloid PET was then conducted and classified as positive or negative. Attending physicians were asked to evaluate whether this result led to a change in diagnosis or altered management. They also reported their degree of confidence in the diagnosis. Caregivers were met after disclosure of amyloid PET results and completed a questionnaire/interview to assess the impact of the scan. Our cohort was evenly divided between positive (14/28) and negative (14/28) 18F-NAV4694 cases. Amyloid PET resulted in a diagnostic change in 9/28 cases (32.1%: 17.8% changed from AD to non-AD, 14.3% from non-AD to AD). There was a 44% increase in diagnostic confidence. Altered management occurred in 71.4% (20/28) of cases. Knowledge of amyloid status improved caregivers' outcomes in all domains (anxiety, depression, disease perception, future anticipation, and quality of life). This study suggests a useful additive role for amyloid PET in atypical cases with an unclear diagnosis beyond the extensive workup of a tertiary memory clinic. Amyloid PET increased diagnostic confidence and led to clinically significant alterations in management. The information gained from that test was well received by caregivers and encouraged spending quality time with their loved ones.

MR-assisted PET motion correction in simultaneous PET/MRI studies of dementia subjects.

Science.gov (United States)

Chen, Kevin T; Salcedo, Stephanie; Chonde, Daniel B; Izquierdo-Garcia, David; Levine, Michael A; Price, Julie C; Dickerson, Bradford C; Catana, Ciprian

2018-03-08

Subject motion in positron emission tomography (PET) studies leads to image blurring and artifacts; simultaneously acquired magnetic resonance imaging (MRI) data provides a means for motion correction (MC) in integrated PET/MRI scanners. To assess the effect of realistic head motion and MR-based MC on static [ 18 F]-fluorodeoxyglucose (FDG) PET images in dementia patients. Observational study. Thirty dementia subjects were recruited. 3T hybrid PET/MR scanner where EPI-based and T 1 -weighted sequences were acquired simultaneously with the PET data. Head motion parameters estimated from high temporal resolution MR volumes were used for PET MC. The MR-based MC method was compared to PET frame-based MC methods in which motion parameters were estimated by coregistering 5-minute frames before and after accounting for the attenuation-emission mismatch. The relative changes in standardized uptake value ratios (SUVRs) between the PET volumes processed with the various MC methods, without MC, and the PET volumes with simulated motion were compared in relevant brain regions. The absolute value of the regional SUVR relative change was assessed with pairwise paired t-tests testing at the P = 0.05 level, comparing the values obtained through different MR-based MC processing methods as well as across different motion groups. The intraregion voxelwise variability of regional SUVRs obtained through different MR-based MC processing methods was also assessed with pairwise paired t-tests testing at the P = 0.05 level. MC had a greater impact on PET data quantification in subjects with larger amplitude motion (higher than 18% in the medial orbitofrontal cortex) and greater changes were generally observed for the MR-based MC method compared to the frame-based methods. Furthermore, a mean relative change of ∼4% was observed after MC even at the group level, suggesting the importance of routinely applying this correction. The intraregion voxelwise variability of regional SUVRs

Extracting a respiratory signal from raw dynamic PET data that contain tracer kinetics.

Science.gov (United States)

Schleyer, P J; Thielemans, K; Marsden, P K

2014-08-07

Data driven gating (DDG) methods provide an alternative to hardware based respiratory gating for PET imaging. Several existing DDG approaches obtain a respiratory signal by observing the change in PET-counts within specific regions of acquired PET data. Currently, these methods do not allow for tracer kinetics which can interfere with the respiratory signal and introduce error. In this work, we produced a DDG method for dynamic PET studies that exhibit tracer kinetics. Our method is based on an existing approach that uses frequency-domain analysis to locate regions within raw PET data that are subject to respiratory motion. In the new approach, an optimised non-stationary short-time Fourier transform was used to create a time-varying 4D map of motion affected regions. Additional processing was required to ensure that the relationship between the sign of the respiratory signal and the physical direction of movement remained consistent for each temporal segment of the 4D map. The change in PET-counts within the 4D map during the PET acquisition was then used to generate a respiratory curve. Using 26 min dynamic cardiac NH3 PET acquisitions which included a hardware derived respiratory measurement, we show that tracer kinetics can severely degrade the respiratory signal generated by the original DDG method. In some cases, the transition of tracer from the liver to the lungs caused the respiratory signal to invert. The new approach successfully compensated for tracer kinetics and improved the correlation between the data-driven and hardware based signals. On average, good correlation was maintained throughout the PET acquisitions.

Authentically radiolabelled Mn(II) complexes as bimodal PET/MR tracers

Energy Technology Data Exchange (ETDEWEB)

Vanasschen, Christian; Brandt, Marie; Ermert, Johannes [Institute of Neuroscience and Medicine, INM-5 - Nuclear Chemistry, Forschungszentrum Jülich (Germany); Neumaier, Bernd [Institute for Radiochemistry and Experimental Molecular Imaging, Medical Clinics, University of Cologne (Germany); Coenen, Heinz H [Institute of Neuroscience and Medicine, INM-5 - Nuclear Chemistry, Forschungszentrum Jülich (Germany)

2015-05-18

The development of small molecule bimodal PET/MR tracers is mainly hampered by the lack of dedicated preparation methods. Authentic radiolabelling of MR contrast agents ensures easy access to such probes: a ligand, chelating a paramagnetic metal ion (e.g. Mn2+) and the corresponding PET isotope (e.g. 52gMn), leads to a “cocktail mixture” where both imaging reporters exhibit the same pharmacokinetics. Paramagnetic [55Mn(CDTA)]2- shows an excellent compromise between thermodynamic stability, kinetic inertness and MR contrast enhancement. Therefore, the aim of this study was to develop new PET/MR tracers by labelling CDTA ligands with paramagnetic manganese and the β+-emitter 52gMn. N.c.a. 52gMn (t1/2: 5.6 d; Eβ+: 575.8 keV (29.6%)) was produced by proton irradiation of a natCr target followed by cation-exchange chromatography. CDTA was radiolabelled with n.c.a. 52gMn2+ in NaOAc buffer (pH 6) at RT. The complex was purified by RP-HPLC and its stability tested in PBS and blood plasma at 37°C. The redox stability was assessed by monitoring the T1 relaxation (20 MHz) in HEPES buffer (pH 7.4). A functionalized CDTA ligand was synthesized in 5 steps. [52gMn(CDTA)]2- was quantitatively formed within 30 min at RT. The complex was stable for at least 6 days in PBS and blood plasma at 37°C and no oxidation occurred within 7 months storage at RT. Labelling CDTA with an isotopic 52g/55Mn2+ mixture led to the corresponding bimodal PET/MR tracer. Furthermore, a functionalized CDTA ligand was synthesized with an overall yield of 18-25%. [52g/55Mn(CDTA)]2-, the first manganese-based bimodal PET/MR tracer prepared, exhibits excellent stability towards decomplexation and oxidation. This makes the functionalized CDTA ligand highly suitable for designing PET/MR tracers with high relaxivity or targeting properties.

Authentically radiolabelled Mn(II) complexes as bimodal PET/MR tracers

International Nuclear Information System (INIS)

Vanasschen, Christian; Brandt, Marie; Ermert, Johannes; Neumaier, Bernd; Coenen, Heinz H

2015-01-01

The development of small molecule bimodal PET/MR tracers is mainly hampered by the lack of dedicated preparation methods. Authentic radiolabelling of MR contrast agents ensures easy access to such probes: a ligand, chelating a paramagnetic metal ion (e.g. Mn2+) and the corresponding PET isotope (e.g. 52gMn), leads to a “cocktail mixture” where both imaging reporters exhibit the same pharmacokinetics. Paramagnetic [55Mn(CDTA)]2- shows an excellent compromise between thermodynamic stability, kinetic inertness and MR contrast enhancement. Therefore, the aim of this study was to develop new PET/MR tracers by labelling CDTA ligands with paramagnetic manganese and the β+-emitter 52gMn. N.c.a. 52gMn (t1/2: 5.6 d; Eβ+: 575.8 keV (29.6%)) was produced by proton irradiation of a natCr target followed by cation-exchange chromatography. CDTA was radiolabelled with n.c.a. 52gMn2+ in NaOAc buffer (pH 6) at RT. The complex was purified by RP-HPLC and its stability tested in PBS and blood plasma at 37°C. The redox stability was assessed by monitoring the T1 relaxation (20 MHz) in HEPES buffer (pH 7.4). A functionalized CDTA ligand was synthesized in 5 steps. [52gMn(CDTA)]2- was quantitatively formed within 30 min at RT. The complex was stable for at least 6 days in PBS and blood plasma at 37°C and no oxidation occurred within 7 months storage at RT. Labelling CDTA with an isotopic 52g/55Mn2+ mixture led to the corresponding bimodal PET/MR tracer. Furthermore, a functionalized CDTA ligand was synthesized with an overall yield of 18-25%. [52g/55Mn(CDTA)]2-, the first manganese-based bimodal PET/MR tracer prepared, exhibits excellent stability towards decomplexation and oxidation. This makes the functionalized CDTA ligand highly suitable for designing PET/MR tracers with high relaxivity or targeting properties.

Extracting a respiratory signal from raw dynamic PET data that contain tracer kinetics

International Nuclear Information System (INIS)

Schleyer, P J; Thielemans, K; Marsden, P K

2014-01-01

Data driven gating (DDG) methods provide an alternative to hardware based respiratory gating for PET imaging. Several existing DDG approaches obtain a respiratory signal by observing the change in PET-counts within specific regions of acquired PET data. Currently, these methods do not allow for tracer kinetics which can interfere with the respiratory signal and introduce error. In this work, we produced a DDG method for dynamic PET studies that exhibit tracer kinetics. Our method is based on an existing approach that uses frequency-domain analysis to locate regions within raw PET data that are subject to respiratory motion. In the new approach, an optimised non-stationary short-time Fourier transform was used to create a time-varying 4D map of motion affected regions. Additional processing was required to ensure that the relationship between the sign of the respiratory signal and the physical direction of movement remained consistent for each temporal segment of the 4D map. The change in PET-counts within the 4D map during the PET acquisition was then used to generate a respiratory curve. Using 26 min dynamic cardiac NH 3 PET acquisitions which included a hardware derived respiratory measurement, we show that tracer kinetics can severely degrade the respiratory signal generated by the original DDG method. In some cases, the transition of tracer from the liver to the lungs caused the respiratory signal to invert. The new approach successfully compensated for tracer kinetics and improved the correlation between the data-driven and hardware based signals. On average, good correlation was maintained throughout the PET acquisitions. (paper)

A Comparative Uptake Study of Multiplexed PET Tracers in Mice with Turpentine-Induced Inflammation

Directory of Open Access Journals (Sweden)

Tingting Huang

2012-11-01

Full Text Available The potential value of multiplexed positron emission tomography (PET tracers in mice with turpentine-induced inflammation was evaluated and compared with 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG for glucose metabolism imaging. These PET tracers included [18F]fluoromethylcholine ([18F]FCH for choline metabolism imaging, (S-[11C]methyl-D-cysteine ([11C]DMCYS for amino acid metabolism imaging, [11C]bis(zinc(II-dipicolylamine ([11C]DPA-Zn2+ for apoptosis imaging, 2-(4-N-[11C]-methylaminophenyl-6-hydroxybenzothiazole ([11C]PIB for β amyloid binding imaging, and [18F]fluoride (18F− for bone metabolism imaging. In mice with turpentine-induced inflammation mice, the biodistribution of all the tracers mentioned above at 5, 15, 30, 45, and 60 min postinjection was determined. Also, the time-course curves of the tracer uptake ratios for inflammatory thigh muscle (IM to normal uninflammatory thigh muscle (NM, IM to blood (BL, IM to brain (BR, and IM to liver (LI were acquired, respectively. Moreover, PET imaging with the tracers within 60 min postinjection on a clinical PET/CT scanner was also conducted. [18F]FDG and 18F− showed relatively higher uptake ratios for IM to NM, IM to BL, IM to BR, and IM to LI than [18F]FCH, [11C]DPA-Zn2+, [11C]DMCYS and [11C]PIB, which were highly consistent with the results delineated in PET images. The results demonstrate that 18F− seems to be a potential PET tracer for inflammation imaging. [18F]FCH and [11C]DMCYS, with lower accumulation in inflammatory tissue than [18F]FDG, are not good PET tracers for inflammation imaging. As a promising inflammatory tracer, the chemical structure of [11C]DPA-Zn2+ needs to be further optimized.

Early [18F]florbetaben and [11C]PiB PET images are a surrogate biomarker of neuronal injury in Alzheimer's disease

International Nuclear Information System (INIS)

Tiepolt, Solveig; Patt, Marianne; Luthardt, Julia; Barthel, Henryk; Hesse, Swen; Sabri, Osama; Schroeter, Matthias L.; Hoffmann, Karl-Titus; Weise, David; Gertz, Hermann-Josef

2016-01-01

[ 18 F]FDG is a commonly used neuronal injury biomarker for early and differential diagnosis of dementia. Typically, the blood supply to the brain is closely coupled to glucose consumption. Early uptake of the Aβ tracer [ 11 C]PiB on PET images is mainly determined by cerebral blood flow and shows a high correlation with [ 18 F]FDG uptake. Uptake data for 18 F-labelled Aβ PET tracers are, however, scarce. We investigated the value of early PET images using the novel Aβ tracer [ 18 F]FBB in the diagnosis of Alzhimers disease (AD). This retrospective analysis included 22 patients with MCI or dementia who underwent dual time-point PET imaging with either [ 11 C]PiB (11 patients) or [ 18 F]FBB (11 patients) in routine clinical practice. Images were acquired 1 - 9 min after administration of both tracers and 40 - 70 min and 90 - 110 min after administration of [ 11 C]PiB and [ 18 F]FBB, respectively. The patients also underwent [ 18 F]FDG brain PET imaging. PET data were analysed visually and semiquantitatively. Associations between early Aβ tracer uptake and dementia as well as brain atrophy were investigated. Regional visual scores of early Aβ tracer and [ 18 F]FDG PET images were significantly correlated (Spearman's ρ = 0.780, P < 0.001). Global brain visual analysis revealed identical results between early Aβ tracer and [ 18 F]FDG PET images. In a VOI-based analysis, the early Aβ tracer data correlated significantly with the [ 18 F]FDG data (r = 0.779, P < 0.001), but there were no differences between [ 18 F]FBB and [ 11 C]PiB. Cortical SUVRs in regions typically affected in AD on early Aβ tracer and [ 18 F]FDG PET images were correlated with MMSE scores (ρ = 0.458, P = 0.032, and ρ = 0.456, P = 0.033, respectively). A voxel-wise group-based search for areas with relatively higher tracer uptake on early Aβ tracer PET images compared with [ 18 F]FDG PET images revealed a small cluster in the midbrain/pons; no significant clusters were found for the

Statistical dynamic imaging of RI-labeled tracer from list-mode PET data

International Nuclear Information System (INIS)

Tanimoto, Michiaki; Kuroda, Yoshihiro; Oshiro, Osamu; Watabe, Hiroshi; Kuroda, Tomohiro

2009-01-01

Positron emission tomography (PET) can be used in physiological analysis to illustrate physiological states by visualizing the accumulation of radioisotope (RI)-labeled tracer in specific organs or tissues. PET obtains spatio-temporal statistics in the form of list-mode data. However, conventional imaging techniques, which sum up list-mode data over a given time period, cannot depict detailed temporal dynamics of the RI-labeled tracer. In this study, a spatio-temporal analysis approach was employed to visualize the temporal flow dynamics of RI-labeled tracer from the obtained list-mode data. Experiments to assess the visualization of simulated RI-labeled tracer dynamics as well as RI-labeled tracer dynamics in a vascular phantom showed that the proposed method successfully depicted detailed temporal flow dynamics that could not be visualized using conventional methods. (author)

Rapid dual-tracer PTSM+ATSM PET imaging of tumour blood flow and hypoxia: a simulation study

International Nuclear Information System (INIS)

Rust, T C; Kadrmas, D J

2006-01-01

Blood flow and hypoxia are interrelated aspects of physiology that affect cancer treatment and response. Cu-PTSM and Cu-ATSM are related PET tracers for blood flow and hypoxia, and the ability to rapidly image both tracers in a single scan would bring several advantages over conventional single-tracer techniques. Using dynamic imaging with staggered injections, overlapping signals for multiple PET tracers may be recovered utilizing information from kinetics and radioactive decay. In this work, rapid dual-tracer PTSM+ATSM PET was simulated and tested as a function of injection delay, order and relative dose for several copper isotopes, and the results were compared relative to separate single-tracer data. Time-activity curves representing a broad range of tumour blood flow and hypoxia levels were simulated, and parallel dual-tracer compartment modelling was used to recover the signals for each tracer. The main results were tested further using a torso phantom simulation of PET tumour imaging. Using scans as short as 30 minutes, the dual-tracer method provided measures of blood flow and hypoxia similar to single-tracer imaging. The best performance was obtained by injecting PTSM first and using a somewhat higher dose for ATSM. Comparable results for different copper isotopes suggest that tracer kinetics with staggered injections play a more important role than radioactive decay in the signal separation process. Rapid PTSM+ATSM PET has excellent potential for characterizing both tumour blood flow and hypoxia in a single, fast scan, provided that technological hurdles related to algorithm development and routine use can be overcome

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-02-01

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

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.

TU-AB-202-11: Tumor Segmentation by Fusion of Multi-Tracer PET Images Using Copula Based Statistical Methods

International Nuclear Information System (INIS)

Lapuyade-Lahorgue, J; Ruan, S; Li, H; Vera, P

2016-01-01

Purpose: Multi-tracer PET imaging is getting more attention in radiotherapy by providing additional tumor volume information such as glucose and oxygenation. However, automatic PET-based tumor segmentation is still a very challenging problem. We propose a statistical fusion approach to joint segment the sub-area of tumors from the two tracers FDG and FMISO PET images. Methods: Non-standardized Gamma distributions are convenient to model intensity distributions in PET. As a serious correlation exists in multi-tracer PET images, we proposed a new fusion method based on copula which is capable to represent dependency between different tracers. The Hidden Markov Field (HMF) model is used to represent spatial relationship between PET image voxels and statistical dynamics of intensities for each modality. Real PET images of five patients with FDG and FMISO are used to evaluate quantitatively and qualitatively our method. A comparison between individual and multi-tracer segmentations was conducted to show advantages of the proposed fusion method. Results: The segmentation results show that fusion with Gaussian copula can receive high Dice coefficient of 0.84 compared to that of 0.54 and 0.3 of monomodal segmentation results based on individual segmentation of FDG and FMISO PET images. In addition, high correlation coefficients (0.75 to 0.91) for the Gaussian copula for all five testing patients indicates the dependency between tumor regions in the multi-tracer PET images. Conclusion: This study shows that using multi-tracer PET imaging can efficiently improve the segmentation of tumor region where hypoxia and glucidic consumption are present at the same time. Introduction of copulas for modeling the dependency between two tracers can simultaneously take into account information from both tracers and deal with two pathological phenomena. Future work will be to consider other families of copula such as spherical and archimedian copulas, and to eliminate partial volume

Towards tracer dose reduction in PET studies: Simulation of dose reduction by retrospective randomized undersampling of list-mode data.

Science.gov (United States)

Gatidis, Sergios; Würslin, Christian; Seith, Ferdinand; Schäfer, Jürgen F; la Fougère, Christian; Nikolaou, Konstantin; Schwenzer, Nina F; Schmidt, Holger

2016-01-01

Optimization of tracer dose regimes in positron emission tomography (PET) imaging is a trade-off between diagnostic image quality and radiation exposure. The challenge lies in defining minimal tracer doses that still result in sufficient diagnostic image quality. In order to find such minimal doses, it would be useful to simulate tracer dose reduction as this would enable to study the effects of tracer dose reduction on image quality in single patients without repeated injections of different amounts of tracer. The aim of our study was to introduce and validate a method for simulation of low-dose PET images enabling direct comparison of different tracer doses in single patients and under constant influencing factors. (18)F-fluoride PET data were acquired on a combined PET/magnetic resonance imaging (MRI) scanner. PET data were stored together with the temporal information of the occurrence of single events (list-mode format). A predefined proportion of PET events were then randomly deleted resulting in undersampled PET data. These data sets were subsequently reconstructed resulting in simulated low-dose PET images (retrospective undersampling of list-mode data). This approach was validated in phantom experiments by visual inspection and by comparison of PET quality metrics contrast recovery coefficient (CRC), background-variability (BV) and signal-to-noise ratio (SNR) of measured and simulated PET images for different activity concentrations. In addition, reduced-dose PET images of a clinical (18)F-FDG PET dataset were simulated using the proposed approach. (18)F-PET image quality degraded with decreasing activity concentrations with comparable visual image characteristics in measured and in corresponding simulated PET images. This result was confirmed by quantification of image quality metrics. CRC, SNR and BV showed concordant behavior with decreasing activity concentrations for measured and for corresponding simulated PET images. Simulation of dose

Prevalence of amyloid PET positivity in dementia syndromes

DEFF Research Database (Denmark)

Ossenkoppele, Rik; Jansen, Willemijn J; Rabinovici, Gil D

2015-01-01

IMPORTANCE: Amyloid-β positron emission tomography (PET) imaging allows in vivo detection of fibrillar plaques, a core neuropathological feature of Alzheimer disease (AD). Its diagnostic utility is still unclear because amyloid plaques also occur in patients with non-AD dementia. OBJECTIVE: To use...

Application of separable parameter space techniques to multi-tracer PET compartment modeling

International Nuclear Information System (INIS)

Zhang, Jeff L; Michael Morey, A; Kadrmas, Dan J

2016-01-01

Multi-tracer positron emission tomography (PET) can image two or more tracers in a single scan, characterizing multiple aspects of biological functions to provide new insights into many diseases. The technique uses dynamic imaging, resulting in time-activity curves that contain contributions from each tracer present. The process of separating and recovering separate images and/or imaging measures for each tracer requires the application of kinetic constraints, which are most commonly applied by fitting parallel compartment models for all tracers. Such multi-tracer compartment modeling presents challenging nonlinear fits in multiple dimensions. This work extends separable parameter space kinetic modeling techniques, previously developed for fitting single-tracer compartment models, to fitting multi-tracer compartment models. The multi-tracer compartment model solution equations were reformulated to maximally separate the linear and nonlinear aspects of the fitting problem, and separable least-squares techniques were applied to effectively reduce the dimensionality of the nonlinear fit. The benefits of the approach are then explored through a number of illustrative examples, including characterization of separable parameter space multi-tracer objective functions and demonstration of exhaustive search fits which guarantee the true global minimum to within arbitrary search precision. Iterative gradient-descent algorithms using Levenberg–Marquardt were also tested, demonstrating improved fitting speed and robustness as compared to corresponding fits using conventional model formulations. The proposed technique overcomes many of the challenges in fitting simultaneous multi-tracer PET compartment models. (paper)

Defining optimal tracer activities in pediatric oncologic whole-body {sup 18}F-FDG-PET/MRI

Energy Technology Data Exchange (ETDEWEB)

Gatidis, Sergios; Schmidt, Holger; Nikolaou, Konstantin; Schwenzer, Nina F.; Schaefer, Juergen F. [University of Tuebingen, Department of Radiology, Diagnostic and Interventional Radiology, Tuebingen (Germany); La Fougere, Christian [University of Tuebingen, Department of Radiology, Nuclear Medicine, Tuebingen (Germany)

2016-12-15

To explore the feasibility of reducing administered tracer activities and to assess optimal activities for combined {sup 18}F-FDG-PET/MRI in pediatric oncology. 30 {sup 18}F-FDG-PET/MRI examinations were performed on 24 patients with known or suspected solid tumors (10 girls, 14 boys, age 12 ± 5.6 [1-18] years; PET scan duration: 4 min per bed position). Low-activity PET images were retrospectively simulated from the originally acquired data sets using randomized undersampling of list mode data. PET data of different simulated administered activities (0.25-2.5 MBq/kg body weight) were reconstructed with or without point spread function (PSF) modeling. Mean and maximum standardized uptake values (SUV{sub mean} and SUV{sub max}) as well as SUV variation (SUV{sub var}) were measured in physiologic organs and focal FDG-avid lesions. Detectability of organ structures and of focal {sup 18}F-FDG-avid lesions as well as the occurrence of false-positive PET lesions were assessed at different simulated tracer activities. Subjective image quality steadily declined with decreasing tracer activities. Compared to the originally acquired data sets, mean relative deviations of SUV{sub mean} and SUV{sub max} were below 5 % at {sup 18}F-FDG activities of 1.5 MBq/kg or higher. Over 95 % of anatomic structures and all pathologic focal lesions were detectable at 1.5 MBq/kg {sup 18}F-FDG. Detectability of anatomic structures and focal lesions was significantly improved using PSF. No false-positive focal lesions were observed at tracer activities of 1 MBq/kg {sup 18}F-FDG or higher. Administration of {sup 18}F-FDG activities of 1.5 MBq/kg is, thus, feasible without obvious diagnostic shortcomings, which is equivalent to a dose reduction of more than 50 % compared to current recommendations. Significant reduction in administered {sup 18}F-FDG tracer activities is feasible in pediatric oncologic PET/MRI. Appropriate activities of {sup 18}F-FDG or other tracers for specific clinical

[18F]Fluoroazabenzoxazoles as potential amyloid plaque PET tracers: synthesis and in vivo evaluation in rhesus monkey

International Nuclear Information System (INIS)

Hostetler, Eric D.; Sanabria-Bohórquez, Sandra; Fan Hong; Zeng, Zhizhen; Gammage, Linda; Miller, Patricia; O'Malley, Stacey; Connolly, Brett; Mulhearn, James; Harrison, Scott T.; Wolkenberg, Scott E.; Barrow, James C.; Williams, David L.; Hargreaves, Richard J.; Sur, Cyrille; Cook, Jacquelynn J.

2011-01-01

Introduction: An 18 F-labeled positron emission tomography (PET) tracer for amyloid plaque is desirable for early diagnosis of Alzheimer's disease, particularly to enable preventative treatment once effective therapeutics are available. Similarly, such a tracer would be useful as a biomarker for enrollment of patients in clinical trials for evaluation of antiamyloid therapeutics. Furthermore, changes in the level of plaque burden as quantified by an amyloid plaque PET tracer may provide valuable insights into the effectiveness of amyloid-targeted therapeutics. This work describes our approach to evaluate and select a candidate PET tracer for in vivo quantification of human amyloid plaque. Methods: Ligands were evaluated for their in vitro binding to human amyloid plaques, lipophilicity and predicted blood–brain barrier permeability. Candidates with favorable in vitro properties were radiolabeled with 18 F and evaluated in vivo. Baseline PET scans in rhesus monkey were conducted to evaluate the regional distribution and kinetics of each tracer using tracer kinetic modeling methods. High binding potential in cerebral white matter and cortical grey matter was considered an unfavorable feature of the candidate tracers. Results: [ 18 F]MK-3328 showed the most favorable combination of low in vivo binding potential in white matter and cortical grey matter in rhesus monkeys, low lipophilicity (Log D=2.91) and high affinity for human amyloid plaques (IC 50 =10.5±1.3 nM). Conclusions: [ 18 F]MK-3328 was identified as a promising PET tracer for in vivo quantification of amyloid plaques, and further evaluation in humans is warranted.

New horizons in cardiac innervation imaging. Introduction of novel 18F-labeled PET tracers

International Nuclear Information System (INIS)

Kobayashi, Ryohei; Chen, Xinyu; Werner, Rudolf A.; Lapa, Constantin; Javadi, Mehrbod S.; Higuchi, Takahiro

2017-01-01

Cardiac sympathetic nervous activity can be uniquely visualized by non-invasive radionuclide imaging techniques due to the fast growing and widespread application of nuclear cardiology in the last few years. The norepinephrine analogue 123 I-meta-iodobenzylguanidine ( 123 I-MIBG) is a single photon emission computed tomography (SPECT) tracer for the clinical implementation of sympathetic nervous imaging for both diagnosis and prognosis of heart failure. Meanwhile, positron emission tomography (PET) imaging has become increasingly attractive because of its higher spatial and temporal resolution compared to SPECT, which allows regional functional and dynamic kinetic analysis. Nevertheless, wider use of cardiac sympathetic nervous PET imaging is still limited mainly due to the demand of costly on-site cyclotrons, which are required for the production of conventional 11 C-labeled (radiological half-life, 20 min) PET tracers. Most recently, more promising 18 F-labeled (half-life, 110 min) PET radiopharmaceuticals targeting sympathetic nervous system have been introduced. These tracers optimize PET imaging and, by using delivery networks, cost less to produce. In this article, the latest advances of sympathetic nervous imaging using 18 F-labeled radiotracers along with their possible applications are reviewed. (orig.)

In vivo amyloid imaging with PET in frontotemporal dementia

International Nuclear Information System (INIS)

Engler, Henry; Santillo, Alexander F.; Lindau, Maria; Lannfelt, Lars; Kilander, Lena; Wang, Shu Xia; Savitcheva, Irina; Nordberg, Agneta; Laangstroem, Bengt

2008-01-01

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.)

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.)

Dosimetry of 64Cu-DOTA-AE105, a PET tracer for uPAR imaging

DEFF Research Database (Denmark)

Persson, Morten; El Ali, Henrik H.; Binderup, Tina

2014-01-01

64Cu-DOTA-AE105 is a novel positron emission tomography (PET) tracer specific to the human urokinase-type plasminogen activator receptor (uPAR). In preparation of using this tracer in humans, as a new promising method to distinguish between indolent and aggressive cancers, we have performed PET...... studies in mice to evaluate the in vivo biodistribution and estimate human dosimetry of 64Cu-DOTA-AE105. MethodsFive mice received iv tail injection of 64Cu-DOTA-AE105 and were PET/CT scanned 1, 4.5 and 22h post injection. Volume-of-interest (VOI) were manually drawn on the following organs: heart, lung......Favorable dosimetry estimates together with previously reported uPAR PET data fully support human testing of 64Cu-DOTA-AE105....

Spectrum of neurocognitive dysfunction in Indian population on FDG PET/CT imaging

International Nuclear Information System (INIS)

Sharma, Rajnish; Tripathi, Madhavi; D’Souza, Maria M; Jaimini, Abhinav; Varshney, Raunak; Panwar, Puja; Kaushik, Aruna; Saw, Sanjeev; Seher, Romana; Pandey, Santosh; Singh, Dinesh; Solanki, Yachna; Mishra, Anil K; Mondal, Anupam; Tripathi, RP

2011-01-01

A variety of neurodegenerative disorders produce significant abnormal brain function which can be detected using fluorodeoxyglucose positron emission tomography (FDG PET) scan even when structural changes are not detected on CT or MRI Scan. A study was undertaken at our institute to evaluate the FDG PET/CT findings in Indian population suffering from mild cognitive impairment (MCI), Alzheimer's disease (AD), fronto-temporal dementia (FTD), dementia with lewy body disease (DLBD) and other miscellaneous causes of dementia. 117 subjects having neurocognitive deficits and 36 normals were included in our study. All patients underwent a detailed history and clinical examination. This was followed by a mini mental state examination. Subsequently an FDG brain PET scan and an MRI were done. In the patient population included in our study group 36 were normal, 39 had MCI, 40 had AD, 14 had FTD, and 13 had DLBD and 11 dementia due to other miscellaneous causes. MCI patients showed primarily reduced tracer uptake in the mesio-temporal cortex. AD patients showed reduced tracer concentration in temporo-parietal lobes, while patients with advanced diseases showed frontal lobe disease additionally. In subjects of FTD, reduced radiotracer uptake in the fronto-temporal lobes was noted. In addition, FTD patients also showed basal ganglia defects. In contrast the DLBD patients showed globally reduced FDG uptake including severely affecting the occipital cortices. In the current study the F18-FDG PET scans have been shown to be highly useful in the diagnosis of various neurocognitive disorders of the brain. AD was found to be the most common dementia in the Indian population followed by MCI. Diffuse Lewy body disease, FTD and other miscellaneous categories of dementia had a near similar incidence

Design and utilisation of protocols to characterise dynamic PET uptake of two tracers using basis pursuit

Science.gov (United States)

Bell, Christopher; Puttick, Simon; Rose, Stephen; Smith, Jye; Thomas, Paul; Dowson, Nicholas

2017-06-01

Imaging using more than one biological process using PET could be of great utility, but despite previously proposed approaches to dual-tracer imaging, it is seldom performed. The alternative of performing multiple scans is often infeasible for clinical practice or even in research studies. Dual-tracer PET scanning allows for multiple PET radiotracers to be imaged within the same imaging session. In this paper we describe our approach to utilise the basis pursuit method to aid in the design of dual-tracer PET imaging experiments, and later in separation of the signals. The advantage of this approach is that it does not require a compartment model architecture to be specified or even that both signals are distinguishable in all cases. This means the method for separating dual-tracer signals can be used for many feasible and useful combinations of biology or radiotracer, once an appropriate scanning protocol has been decided upon. Following a demonstration in separating the signals from two consecutively injected radionuclides in a controlled experiment, phantom and list-mode mouse experiments demonstrated the ability to test the feasibility of dual-tracer imaging protocols for multiple injection delays. Increases in variances predicted for kinetic macro-parameters V D and K I in brain and tumoral tissue were obtained when separating the synthetically combined data. These experiments confirmed previous work using other approaches that injections delays of 10-20 min ensured increases in variance were kept minimal for the test tracers used. On this basis, an actual dual-tracer experiment using a 20 min delay was performed using these radio tracers, with the kinetic parameters (V D and K I) extracted for each tracer in agreement with the literature. This study supports previous work that dual-tracer PET imaging can be accomplished provided certain constraints are adhered to. The utilisation of basis pursuit techniques, with its removed need to specify a model

A Japanese nationwide survey on the FDG-PET scans for dementia. Analysis on the predicted costs and benefits of FDG-PET for early diagnosis of Alzheimer

International Nuclear Information System (INIS)

Senda, Michio; Ouchi, Yasuomi; Ishii, Kazunari

2003-01-01

A nation-wide survey was carried out on the FDG-PET scans for the diagnosis of dementia by the FDG-PET Working Group organized by both the Japan Radioisotope Association and the Japanese Society of Nuclear Medicine. A total of 406 case reports were presented by 15 PET centers for one year. The purpose of the PET scans included early diagnosis of Alzheimer-type Dementia (154 cases, group A) and differential diagnosis of degenerative dementia (144 cases, group B), which was achieved by the PET scan in most cases. The PET scan turned out to allow omitting cerebral blood flow (CBF)-SPECT scans. Since donepezil treatment of the Alzheimer patients prevents the progress of the disease and reduces the care cost, an economic evaluation was performed on the two-year projected cost and benefit of FDG-PET. The reduction of the total cost by incorporating PET into the protocol was predicted to be 61500 yen (group A) and 13700 yen (group B) per person. The increase of the quality adjusted life year (QALY) was predicted to be 0.0442 (group A) and 0.0137 (group B). Therefore, incorporation of PET into the clinical pass was shown to be an economically dominant. As the number of potential subjects for early diagnosis of dementia is estimated to be 9000 across the country every year, PET is expected to increase their quality of life equivalent to 398 intact persons per year while reducing the cost of health care by 554 million yen. (author)

Comparison of PET and proton NMR imaging in the diagnosis of Alzheimer-type dementia

International Nuclear Information System (INIS)

Friedland, R.P.; Budinger, T.F.; Jagust, W.J.; Brant-Zawadzki, M.

1985-01-01

Despite recent advances in the understanding of the pathophysiology of Alzheimer's disease (AD), medical personnel remain unable to make the diagnosis noninvasively, except by exclusion. The more recently developed technique of positron emission tomography (PET) has been used with a labeled glucose analogue, ( 18 F)-2-fluoro-2-deoxy-D-glucose (FDG), to noninvasively study glucose metabolism in dementia. Specific regional alterations, particularly in the temporal-parietal cortex, have been found. Nuclear magnetic resonance (NMR) imaging is another powerful new technology that is beginning to be applied to dementia. The authors have compared the findings in PET studies using FDG with NMR imaging in two subjects with Alzheimer-type dementia

Multimodal PET Imaging of Amyloid and Tau Pathology in Alzheimer Disease and Non-Alzheimer Disease Dementias.

Science.gov (United States)

Xia, Chenjie; Dickerson, Bradford C

2017-07-01

Biomarkers of the molecular pathology underpinning dementia syndromes are increasingly recognized as crucial for diagnosis and development of disease-modifying treatments. Amyloid PET imaging is an integral part of the diagnostic assessment of Alzheimer disease. Its use has also deepened understanding of the role of amyloid pathology in Lewy body disorders and aging. Tau PET imaging is an imaging biomarker that will likely play an important role in the diagnosis, monitoring, and treatment in dementias. Using tau PET imaging to examine how tau pathology relates to amyloid and other markers of neurodegeneration will serve to better understand the pathophysiologic cascade that leads to dementia. Copyright © 2017 Elsevier Inc. All rights reserved.

Multi-contrast attenuation map synthesis for PET/MR scanners: assessment on FDG and Florbetapir PET tracers

Energy Technology Data Exchange (ETDEWEB)

Burgos, Ninon [University College London, Translational Imaging Group, Centre for Medical Image Computing, London (United Kingdom); Cardoso, M.J.; Modat, Marc; Ourselin, Sebastien [University College London, Translational Imaging Group, Centre for Medical Image Computing, London (United Kingdom); University College London, Dementia Research Centre, Institute of Neurology, London (United Kingdom); Thielemans, Kris; Dickson, John [University College London, Institute of Nuclear Medicine, London (United Kingdom); Schott, Jonathan M. [University College London, Dementia Research Centre, Institute of Neurology, London (United Kingdom); Atkinson, David [University College London, Centre for Medical Imaging, London (United Kingdom); Arridge, Simon R. [University College London, Centre for Medical Image Computing, London (United Kingdom); Hutton, Brian F. [University College London, Institute of Nuclear Medicine, London (United Kingdom); University of Wollongong, Centre for Medical Radiation Physics, Wollongong, NSW (Australia)

2015-08-15

Positron Emission Tomography/Magnetic Resonance Imaging (PET/MR) scanners are expected to offer a new range of clinical applications. Attenuation correction is an essential requirement for quantification of PET data but MRI images do not directly provide a patient-specific attenuation map. Methods We further validate and extend a Computed Tomography (CT) and attenuation map (μ-map) synthesis method based on pre-acquired MRI-CT image pairs. The validation consists of comparing the CT images synthesised with the proposed method to the original CT images. PET images were acquired using two different tracers ({sup 18}F-FDG and {sup 18}F-florbetapir). They were then reconstructed and corrected for attenuation using the synthetic μ-maps and compared to the reference PET images corrected with the CT-based μ-maps. During the validation, we observed that the CT synthesis was inaccurate in areas such as the neck and the cerebellum, and propose a refinement to mitigate these problems, as well as an extension of the method to multi-contrast MRI data. Results With the improvements proposed, a significant enhancement in CT synthesis, which results in a reduced absolute error and a decrease in the bias when reconstructing PET images, was observed. For both tracers, on average, the absolute difference between the reference PET images and the PET images corrected with the proposed method was less than 2%, with a bias inferior to 1%. Conclusion With the proposed method, attenuation information can be accurately derived from MRI images by synthesising CT using routine anatomical sequences. MRI sequences, or combination of sequences, can be used to synthesise CT images, as long as they provide sufficient anatomical information. (orig.)

Defining optimal tracer activities in pediatric oncologic whole-body "1"8F-FDG-PET/MRI

International Nuclear Information System (INIS)

Gatidis, Sergios; Schmidt, Holger; Nikolaou, Konstantin; Schwenzer, Nina F.; Schaefer, Juergen F.; La Fougere, Christian

2016-01-01

To explore the feasibility of reducing administered tracer activities and to assess optimal activities for combined "1"8F-FDG-PET/MRI in pediatric oncology. 30 "1"8F-FDG-PET/MRI examinations were performed on 24 patients with known or suspected solid tumors (10 girls, 14 boys, age 12 ± 5.6 [1-18] years; PET scan duration: 4 min per bed position). Low-activity PET images were retrospectively simulated from the originally acquired data sets using randomized undersampling of list mode data. PET data of different simulated administered activities (0.25-2.5 MBq/kg body weight) were reconstructed with or without point spread function (PSF) modeling. Mean and maximum standardized uptake values (SUV_m_e_a_n and SUV_m_a_x) as well as SUV variation (SUV_v_a_r) were measured in physiologic organs and focal FDG-avid lesions. Detectability of organ structures and of focal "1"8F-FDG-avid lesions as well as the occurrence of false-positive PET lesions were assessed at different simulated tracer activities. Subjective image quality steadily declined with decreasing tracer activities. Compared to the originally acquired data sets, mean relative deviations of SUV_m_e_a_n and SUV_m_a_x were below 5 % at "1"8F-FDG activities of 1.5 MBq/kg or higher. Over 95 % of anatomic structures and all pathologic focal lesions were detectable at 1.5 MBq/kg "1"8F-FDG. Detectability of anatomic structures and focal lesions was significantly improved using PSF. No false-positive focal lesions were observed at tracer activities of 1 MBq/kg "1"8F-FDG or higher. Administration of "1"8F-FDG activities of 1.5 MBq/kg is, thus, feasible without obvious diagnostic shortcomings, which is equivalent to a dose reduction of more than 50 % compared to current recommendations. Significant reduction in administered "1"8F-FDG tracer activities is feasible in pediatric oncologic PET/MRI. Appropriate activities of "1"8F-FDG or other tracers for specific clinical questions have to be further established in selected

Development of [18F]afatinib as new TKI-PET tracer for EGFR positive tumors

International Nuclear Information System (INIS)

Slobbe, Paul; Windhorst, Albert D.; Walsum, Marijke Stigter-van; Schuit, Robert C.; Smit, Egbert F.; Niessen, Heiko G.; Solca, Flavio; Stehle, Gerd; Dongen, Guus A.M.S. van; Poot, Alex J.

2014-01-01

Introduction: Afatinib is an irreversible ErbB family blocker that was approved for the treatment of EGFR mutated non-small cell lung cancer in 2013. Positron emission tomography (PET) with fluorine-18 labeled afatinib provides a means to obtain improved understanding of afatinib tumor disposition in vivo. PET imaging with [ 18 F]afatinib may also provide a method to select treatment responsive patients. The aim of this study was to label afatinib with fluorine-18 and evaluate its potential as TKI-PET tracer in tumor bearing mice. Methods: A radiochemically novel coupling, using peptide coupling reagent BOP, was explored and optimized to synthesize [ 18 F]afatinib, followed by a metabolite analysis and biodistribution studies in two clinically relevant lung cancer cell lines, xenografted in nude mice. Results: A reliable [ 18 F]afatinib radiosynthesis was developed and the tracer could be produced in yields of 17.0 ± 2.5% calculated from [ 18 F]F − and >98% purity. The identity of the product was confirmed by co-injection on HPLC with non-labeled afatinib. Metabolite analysis revealed a moderate rate of metabolism, with >80% intact tracer in plasma at 45 min p.i. Biodistribution studies revealed rapid tumor accumulation and good retention for a period of at least 2 hours, while background tissues showed rapid clearance of the tracer. Conclusion: We have developed a method to synthesize [ 18 F]afatinib and related fluorine-18 labeled 4-anilinoquinazolines. [ 18 F]Afatinib showed good stability in vivo, justifying further evaluation as a TKI-PET tracer

New horizons in cardiac innervation imaging. Introduction of novel {sup 18}F-labeled PET tracers

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Ryohei [University Hospital of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Nihon Medi-Physics Co., Ltd., Research Centre, Chiba (Japan); Chen, Xinyu [University Hospital of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); University Hospital of Wuerzburg, Comprehensive Heart Failure Center, Wuerzburg (Germany); Werner, Rudolf A. [University Hospital of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); University Hospital of Wuerzburg, Comprehensive Heart Failure Center, Wuerzburg (Germany); Johns Hopkins School of Medicine, The Russell H Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Lapa, Constantin [University Hospital of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Javadi, Mehrbod S. [Johns Hopkins School of Medicine, The Russell H Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Higuchi, Takahiro [University Hospital of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); University Hospital of Wuerzburg, Comprehensive Heart Failure Center, Wuerzburg (Germany); National Cerebral and Cardiovascular Center, Department of Biomedical Imaging, Research Institute, Suita (Japan)

2017-12-15

Cardiac sympathetic nervous activity can be uniquely visualized by non-invasive radionuclide imaging techniques due to the fast growing and widespread application of nuclear cardiology in the last few years. The norepinephrine analogue {sup 123}I-meta-iodobenzylguanidine ({sup 123}I-MIBG) is a single photon emission computed tomography (SPECT) tracer for the clinical implementation of sympathetic nervous imaging for both diagnosis and prognosis of heart failure. Meanwhile, positron emission tomography (PET) imaging has become increasingly attractive because of its higher spatial and temporal resolution compared to SPECT, which allows regional functional and dynamic kinetic analysis. Nevertheless, wider use of cardiac sympathetic nervous PET imaging is still limited mainly due to the demand of costly on-site cyclotrons, which are required for the production of conventional {sup 11}C-labeled (radiological half-life, 20 min) PET tracers. Most recently, more promising {sup 18}F-labeled (half-life, 110 min) PET radiopharmaceuticals targeting sympathetic nervous system have been introduced. These tracers optimize PET imaging and, by using delivery networks, cost less to produce. In this article, the latest advances of sympathetic nervous imaging using {sup 18}F-labeled radiotracers along with their possible applications are reviewed. (orig.)

Development of a PET tracer for imaging EGFR tyrosine kinase: evaluation of the suitability of PKI166

International Nuclear Information System (INIS)

Kernchen, R.; Brust, P.; Krause, M.; Baumann, M.

2002-01-01

The suitability of PKI166 for the development of a PET tracer for imaging EGFR tyrosine kinase was investigated. Binding studies using EGFR positive tumour tissue and tritiated PKI166 as the radioligand indicated a low binding affinity of PKI166 to the target tissue. PKI166 is therefore not recommended for PET tracer development. (orig.)

Synthesis and preclinical evaluation of [11C]PAQ as a PET imaging tracer for VEGFR-2

International Nuclear Information System (INIS)

Samen, Erik; Stone-Elander, Sharon; Thorell, Jan-Olov; Lu, Li; Tegnebratt, Tetyana; Holmgren, Lars

2009-01-01

R,S-N-(4-Bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methox y)-4-quinazolinamine (PAQ) is a tyrosine kinase inhibitor with high affinity for the vascular endothelial growth factor receptor 2 (VEGFR-2), which plays an important role in tumour angiogenesis. The aim of this work was to develop and evaluate in mice the 11 C-labelled analogue as an in vivo tracer for VEGFR-2 expression in solid tumours. [ 11 C]PAQ was synthesized by an N-methylation of desmethyl-PAQ using [ 11 C]methyl iodide. The tracer's pharmacokinetic properties and its distribution in both subcutaneous and intraperitoneal tumour models were evaluated with positron emission tomography (PET). [ 18 F]FDG was used as a reference tracer for tumour growth. PET results were corroborated by ex vivo and in vitro phosphor imaging and immunohistochemical analyses. In vitro assays and PET in healthy animals revealed low tracer metabolism, limited excretion over 60 min and a saturable and irreversible binding. Radiotracer uptake in subcutaneous tumour masses was low, while focal areas of high uptake (up to 8% ID/g) were observed in regions connecting the tumour to the host. Uptake was similarly high but more distributed in tumours growing within the peritoneum. The pattern of radiotracer uptake was generally different from that of the metabolic tracer [ 18 F]FDG and correlated well with variations in VEGFR-2 expression determined ex vivo by immunohistochemical analysis. These results suggest that [ 11 C]PAQ has potential as a noninvasive PET tracer for in vivo imaging of VEGFR-2 expression in angiogenic ''hot spots''. (orig.)

Synthesis and preclinical evaluation of [(11)C]PAQ as a PET imaging tracer for VEGFR-2.

Science.gov (United States)

Samén, Erik; Thorell, Jan-Olov; Lu, Li; Tegnebratt, Tetyana; Holmgren, Lars; Stone-Elander, Sharon

2009-08-01

(R,S)-N-(4-Bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolinamine (PAQ) is a tyrosine kinase inhibitor with high affinity for the vascular endothelial growth factor receptor 2 (VEGFR-2), which plays an important role in tumour angiogenesis. The aim of this work was to develop and evaluate in mice the (11)C-labelled analogue as an in vivo tracer for VEGFR-2 expression in solid tumours. [(11)C]PAQ was synthesized by an N-methylation of desmethyl-PAQ using [(11)C]methyl iodide. The tracer's pharmacokinetic properties and its distribution in both subcutaneous and intraperitoneal tumour models were evaluated with positron emission tomography (PET). [(18)F]FDG was used as a reference tracer for tumour growth. PET results were corroborated by ex vivo and in vitro phosphor imaging and immunohistochemical analyses. In vitro assays and PET in healthy animals revealed low tracer metabolism, limited excretion over 60 min and a saturable and irreversible binding. Radiotracer uptake in subcutaneous tumour masses was low, while focal areas of high uptake (up to 8% ID/g) were observed in regions connecting the tumour to the host. Uptake was similarly high but more distributed in tumours growing within the peritoneum. The pattern of radiotracer uptake was generally different from that of the metabolic tracer [(18)F]FDG and correlated well with variations in VEGFR-2 expression determined ex vivo by immunohistochemical analysis. These results suggest that [(11)C]PAQ has potential as a noninvasive PET tracer for in vivo imaging of VEGFR-2 expression in angiogenic "hot spots".

Focuss algorithm application in kinetic compartment modeling for PET tracer

International Nuclear Information System (INIS)

Huang Xinrui; Bao Shanglian

2004-01-01

Molecular imaging is in the process of becoming. Its application mostly depends on the molecular discovery process of imaging probes and drugs, from the mouse to the patient, from research to clinical practice. Positron emission tomography (PET) can non-invasively monitor . pharmacokinetic and functional processes of drugs in intact organisms at tracer concentrations by kinetic modeling. It has been known that for all biological systems, linear or nonlinear, if the system is injected by a tracer in a steady state, the distribution of the tracer follows the kinetics of a linear compartmental system, which has sums of exponential solutions. Based on the general compartmental description of the tracer's fate in vivo, we presented a novel kinetic modeling approach for the quantification of in vivo tracer studies with dynamic positron emission tomography (PET), which can determine a parsimonious model consisting with the measured data. This kinetic modeling technique allows for estimation of parametric images from a voxel based analysis and requires no a priori decision about the tracer's fate in vivo, instead determining the most appropriate model from the information contained within the kinetic data. Choosing a set of exponential functions, convolved with the plasma input function, as basis functions, the time activity curve of a region or a pixel can be written as a linear combination of the basis functions with corresponding coefficients. The number of non-zero coefficients returned corresponds to the model order which is related to the number of tissue compartments. The system macro parameters are simply determined using the focal underdetermined system solver (FOCUSS) algorithm. The FOCUSS algorithm is a nonparametric algorithm for finding localized energy solutions from limited data and is a recursive linear estimation procedure. FOCUSS algorithm usually converges very fast, so demands a few iterations. The effectiveness is verified by simulation and clinical

Search for a non-metabolizable PET tracer for heart neuronal imaging

International Nuclear Information System (INIS)

Wieland, D.M.; Rosenspire, K.C.; Van Dort, M.E.; Haka, M.S.; Jung, Y.W.; Gildersleeve, D.L.

1990-01-01

The tracer (1R,2S)-(-)-[ 11 C]-meta-hydroxyephedrine (MHED) is used successfully at the authors' institution to study neuronal heart diseases and neuroendocrine tumors. However, MHED is rapidly metabolized in humans, most likely to alpha-methylepinephrine and its 3-O-methyl ether by the initial action of liver microsomal hydroxylase. This presentation will describe efforts to develop a [ 11 C]-labelled neuronal tracer that is completely resistant to metabolism on the PET-imaging time scale

A new PET tracer specific for vascular endothelial growth factor receptor

International Nuclear Information System (INIS)

Wang, Hui; Cai, Weibo; Chen, Kai; Li, Zi-Bo; Kashefi, Amir; He, Lina; Chen, Xiaoyuan

2007-01-01

Noninvasive positron emission tomography (PET) imaging of vascular endothelial growth factor receptor 2 (VEGFR-2) expression could be a valuable tool for evaluation of patients with a variety of malignancies, and particularly for monitoring those undergoing antiangiogenic therapies that block VEGF/VEGFR-2 function. The aim of this study was to develop a VEGFR-2-specific PET tracer. The D63AE64AE67A mutant of VEGF 121 (VEGF DEE ) was generated by recombinant DNA technology. VEGF 121 and VEGF DEE were purified and conjugated with DOTA for 64 Cu labeling. The DOTA conjugates were tested in vitro for VEGFR-2 specificity and functional activity. In vivo tumor targeting efficacy and pharmacokinetics of 64 Cu-labeled VEGF 121 and VEGF DEE were compared using an orthotopic 4T1 murine breast tumor model. Blocking experiments, biodistribution studies, and immunofluorescence staining were carried out to confirm the noninvasive imaging results. Cell binding assay demonstrated that VEGF DEE had about 20-fold lower VEGFR-1 binding affinity and only slightly lower VEGFR-2 binding affinity as compared with VEGF 121 . MicroPET imaging studies revealed that both 64 Cu-DOTA-VEGF 121 and 64 Cu-DOTA-VEGF DEE had rapid and prominent activity accumulation in VEGFR-2-expressing 4T1 tumors. The renal uptake of 64 Cu-DOTA-VEGF DEE was significantly lower than that of 64 Cu-DOTA-VEGF 121 as rodent kidneys expressed high levels of VEGFR-1 based on immunofluorescence staining. Blocking experiments and biodistribution studies confirmed the VEGFR specificity of 64 Cu-DOTA-VEGF DEE . We have developed a VEGFR-2-specific PET tracer, 64 Cu-DOTA-VEGF DEE . It has comparable tumor targeting efficacy to 64 Cu-DOTA-VEGF 121 but much reduced renal toxicity. This tracer may be translated into the clinic for imaging tumor angiogenesis and monitoring antiangiogenic treatment efficacy. (orig.)

FDG-PET and CSF biomarker accuracy in prediction of conversion to different dementias in a large multicentre MCI cohort.

Science.gov (United States)

Caminiti, Silvia Paola; Ballarini, Tommaso; Sala, Arianna; Cerami, Chiara; Presotto, Luca; Santangelo, Roberto; Fallanca, Federico; Vanoli, Emilia Giovanna; Gianolli, Luigi; Iannaccone, Sandro; Magnani, Giuseppe; Perani, Daniela

2018-01-01

In this multicentre study in clinical settings, we assessed the accuracy of optimized procedures for FDG-PET brain metabolism and CSF classifications in predicting or excluding the conversion to Alzheimer's disease (AD) dementia and non-AD dementias. We included 80 MCI subjects with neurological and neuropsychological assessments, FDG-PET scan and CSF measures at entry, all with clinical follow-up. FDG-PET data were analysed with a validated voxel-based SPM method. Resulting single-subject SPM maps were classified by five imaging experts according to the disease-specific patterns, as "typical-AD", "atypical-AD" (i.e. posterior cortical atrophy, asymmetric logopenic AD variant, frontal-AD variant), "non-AD" (i.e. behavioural variant FTD, corticobasal degeneration, semantic variant FTD; dementia with Lewy bodies) or "negative" patterns. To perform the statistical analyses, the individual patterns were grouped either as "AD dementia vs. non-AD dementia (all diseases)" or as "FTD vs. non-FTD (all diseases)". Aβ42, total and phosphorylated Tau CSF-levels were classified dichotomously, and using the Erlangen Score algorithm. Multivariate logistic models tested the prognostic accuracy of FDG-PET-SPM and CSF dichotomous classifications. Accuracy of Erlangen score and Erlangen Score aided by FDG-PET SPM classification was evaluated. The multivariate logistic model identified FDG-PET "AD" SPM classification (Expβ = 19.35, 95% C.I. 4.8-77.8, p CSF Aβ42 (Expβ = 6.5, 95% C.I. 1.64-25.43, p CSF biomarkers.

Novel targets for positron emission tomography (PET) radiopharmaceutical tracers for visualization of neuroinflammation

Science.gov (United States)

Shchepetkin, I.; Shvedova, M.; Anfinogenova, Y.; Litvak, M.; Atochin, D.

2017-08-01

Non-invasive molecular imaging techniques can enhance diagnosis of neurological diseases to achieve their successful treatment. Positron emission tomography (PET) imaging can identify activated microglia and provide detailed functional information based on molecular biology. This imaging modality is based on detection of isotope labeled tracers, which emit positrons. The review summarizes the developments of various radiolabeled ligands for PET imaging of neuroinflammation.

Semi-automatic synthesis and biological evaluation of 18F-FCH as an oncologic PET tracer

International Nuclear Information System (INIS)

Wu Zhanhong; Wang Shizhen; Zhou Qian; Fu Zhe; Qiu Feichan; Huo Li

2005-01-01

18 F-fluromethylcholine ( 18 F-FCH) as a PET tracer is synthesized. The semi-automatic synthesis assembly of 18 F-FCH is modified from CPCU(CTI). The radiochemical purity is measured by analytical HPLC. The radiochemical yield and the radiochemical purity of 18 F-FCH are 15% and >99%, respectively. The total radiosynthesis time is 55 min after EOB. The labeled product exhibited low toxicity. The biodistribution in normal mice and the toxicity are studied. PET imaging with 18 F-FCH is performed on tumor xenograft murine model. The semi-automatic synthesis assembly is promising to be used for routine clinic radiopharmaceutical preparation and preliminary study has shown the usefulness of 18 F-FCH as an oncologic PET tracer. (authors)

[11C]UCB-A, a novel PET tracer for synaptic vesicle protein 2 A

International Nuclear Information System (INIS)

Estrada, Sergio; Lubberink, Mark; Thibblin, Alf; Sprycha, Margareta; Buchanan, Tim; Mestdagh, Nathalie; Kenda, Benoit; Mercier, Joel; Provins, Laurent; Gillard, Michel; Tytgat, Dominique; Antoni, Gunnar

2016-01-01

Introduction: Development of a selective and specific high affinity PET tracer, [ 11 C]UCB-A, for the in vivo study of SV2A expression in humans. Radiochemistry and preclinical studies in rats and pigs including development of a tracer kinetic model to determine V T . A method for the measurement of percent intact tracer in plasma was developed and the radiation dosimetry was determined in rats. Results: 3–5 GBq of [ 11 C]UCB-A could be produced with radiochemical purity exceeding 98% with a specific radioactivity of around 65 GBq/μmol. In vitro binding showed high selective binding towards SV2A. [ 11 C]UCB-A displayed a dose-dependent and reversible binding to SV2A as measured with PET in rats and pigs and the V T could be determined by Logan analysis. The dosimetry was favorable and low enough to allow multiple administrations of [ 11 C]UCB-A to healthy volunteers, and the metabolite analysis showed no sign of labeled metabolites in brain. Conclusions: We have developed the novel PET tracer, [ 11 C]UCB-A, that can be used to measure SV2A expression in vivo. The dosimetry allows up to 5 administrations of 400 MBq of [ 11 C]UCB-A in humans. Apart from measuring drug occupancy, as we have shown, the tracer can potentially be used to compare SV2A expression between individuals because of the rather narrow range of baseline V T values. This will have to be further validated in human studies.

Quantitative dynamic ¹⁸FDG-PET and tracer kinetic analysis of soft tissue sarcomas.

Science.gov (United States)

Rusten, Espen; Rødal, Jan; Revheim, Mona E; Skretting, Arne; Bruland, Oyvind S; Malinen, Eirik

2013-08-01

To study soft tissue sarcomas using dynamic positron emission tomography (PET) with the glucose analog tracer [(18)F]fluoro-2-deoxy-D-glucose ((18)FDG), to investigate correlations between derived PET image parameters and clinical characteristics, and to discuss implications of dynamic PET acquisition (D-PET). D-PET images of 11 patients with soft tissue sarcomas were analyzed voxel-by-voxel using a compartment tracer kinetic model providing estimates of transfer rates between the vascular, non-metabolized, and metabolized compartments. Furthermore, standard uptake values (SUVs) in the early (2 min p.i.; SUVE) and late (45 min p.i.; SUVL) phases of the PET acquisition were obtained. The derived transfer rates K1, k2 and k3, along with the metabolic rate of (18)FDG (MRFDG) and the vascular fraction νp, was fused with the computed tomography (CT) images for visual interpretation. Correlations between D-PET imaging parameters and clinical parameters, i.e. tumor size, grade and clinical status, were calculated with a significance level of 0.05. The temporal uptake pattern of (18)FDG in the tumor varied considerably from patient to patient. SUVE peak was higher than SUVL peak for four patients. The images of the rate constants showed a systematic pattern, often with elevated intensity in the tumors compared to surrounding tissue. Significant correlations were found between SUVE/L and some of the rate parameters. Dynamic (18)FDG-PET may provide additional valuable information on soft tissue sarcomas not obtainable from conventional (18)FDG-PET. The prognostic role of dynamic imaging should be investigated.

Synthesis and preclinical evaluation of [{sup 11}C]PAQ as a PET imaging tracer for VEGFR-2

Energy Technology Data Exchange (ETDEWEB)

Samen, Erik; Stone-Elander, Sharon [Karolinska University Hospital Solna, Karolinska Pharmacy, Stockholm (Sweden); Karolinska Institutet, Clinical Neurosciences, Stockholm (Sweden); Thorell, Jan-Olov [Karolinska University Hospital Solna, Karolinska Pharmacy, Stockholm (Sweden); Lu, Li [Karolinska Institutet, Clinical Neurosciences, Stockholm (Sweden); Tegnebratt, Tetyana; Holmgren, Lars [Karolinska Institutet, Cancer Center Karolinska, Oncology-Pathology, Stockholm (Sweden)

2009-08-15

(R,S)-N-(4-Bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolinamine (PAQ) is a tyrosine kinase inhibitor with high affinity for the vascular endothelial growth factor receptor 2 (VEGFR-2), which plays an important role in tumour angiogenesis. The aim of this work was to develop and evaluate in mice the {sup 11}C-labelled analogue as an in vivo tracer for VEGFR-2 expression in solid tumours. [{sup 11}C]PAQ was synthesized by an N-methylation of desmethyl-PAQ using [{sup 11}C]methyl iodide. The tracer's pharmacokinetic properties and its distribution in both subcutaneous and intraperitoneal tumour models were evaluated with positron emission tomography (PET). [{sup 18}F]FDG was used as a reference tracer for tumour growth. PET results were corroborated by ex vivo and in vitro phosphor imaging and immunohistochemical analyses. In vitro assays and PET in healthy animals revealed low tracer metabolism, limited excretion over 60 min and a saturable and irreversible binding. Radiotracer uptake in subcutaneous tumour masses was low, while focal areas of high uptake (up to 8% ID/g) were observed in regions connecting the tumour to the host. Uptake was similarly high but more distributed in tumours growing within the peritoneum. The pattern of radiotracer uptake was generally different from that of the metabolic tracer [{sup 18}F]FDG and correlated well with variations in VEGFR-2 expression determined ex vivo by immunohistochemical analysis. These results suggest that [{sup 11}C]PAQ has potential as a noninvasive PET tracer for in vivo imaging of VEGFR-2 expression in angiogenic ''hot spots''. (orig.)

Astrocytic tracer dynamics estimated from [1-11C]-acetate PET measurements

DEFF Research Database (Denmark)

Arnold, Andrea; Calvetti, Daniela; Gjedde, Albert

2015-01-01

We address the problem of estimating the unknown parameters of a model of tracer kinetics from sequences of positron emission tomography (PET) scan data using a statistical sequential algorithm for the inference of magnitudes of dynamic parameters. The method, based on Bayesian statistical...... inference, is a modification of a recently proposed particle filtering and sequential Monte Carlo algorithm, where instead of preassigning the accuracy in the propagation of each particle, we fix the time step and account for the numerical errors in the innovation term. We apply the algorithm to PET images...

Florbetapir F18 PET Amyloid Neuroimaging and Characteristics in Patients With Mild and Moderate Alzheimer Dementia.

Science.gov (United States)

Degenhardt, Elisabeth K; Witte, Michael M; Case, Michael G; Yu, Peng; Henley, David B; Hochstetler, Helen M; D'Souza, Deborah N; Trzepacz, Paula T

2016-01-01

Clinical diagnosis of Alzheimer disease (AD) is challenging, with a 70.9%-87.3% sensitivity and 44.3%-70.8% specificity, compared with autopsy diagnosis. Florbetapir F18 positron emission tomography (FBP-PET) estimates beta-amyloid plaque density antemortem. Of 2052 patients (≥55 years old) clinically diagnosed with mild or moderate AD dementia from 2 solanezumab clinical trials, 390 opted to participate in a FBP-PET study addendum. We analyzed baseline prerandomization characteristics. A total of 22.4% had negative FBP-PET scans, whereas 72.5% of mild and 86.9% of moderate AD patients had positive results. No baseline clinical variable reliably differentiated negative from positive FBP-PET scan groups. These data confirm the challenges of correctly diagnosing AD without using biomarkers. FBP-PET can aid AD dementia differential diagnosis by detecting amyloid pathology antemortem, even when the diagnosis of AD is made by expert clinicians. Copyright © 2016 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.

Measuring serotonin synthesis: from conventional methods to PET tracers and their (pre)clinical implications

Energy Technology Data Exchange (ETDEWEB)

Visser, Anniek K.D.; Waarde, Aren van; Willemsen, Antoon T.M. [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Bosker, Fokko J. [University of Groningen, University Medical Center Groningen, University Center of Psychiatry, Groningen (Netherlands); Luiten, Paul G.M. [University of Groningen, Center for Behavior and Neurosciences, Department of Molecular Neurobiology, Haren (Netherlands); Boer, Johan A. den [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Groningen, University Medical Center Groningen, University Center of Psychiatry, Groningen (Netherlands); Kema, Ido P. [University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, Groningen (Netherlands); Dierckx, Rudi A.J.O. [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University Hospital Ghent, Department of Nuclear Medicine, Ghent (Belgium)

2011-03-15

The serotonergic system of the brain is complex, with an extensive innervation pattern covering all brain regions and endowed with at least 15 different receptors (each with their particular distribution patterns), specific reuptake mechanisms and synthetic processes. Many aspects of the functioning of the serotonergic system are still unclear, partially because of the difficulty of measuring physiological processes in the living brain. In this review we give an overview of the conventional methods of measuring serotonin synthesis and methods using positron emission tomography (PET) tracers, more specifically with respect to serotonergic function in affective disorders. Conventional methods are invasive and do not directly measure synthesis rates. Although they may give insight into turnover rates, a more direct measurement may be preferred. PET is a noninvasive technique which can trace metabolic processes, like serotonin synthesis. Tracers developed for this purpose are {alpha}-[{sup 11}C]methyltryptophan ([{sup 11}C]AMT) and 5-hydroxy-L-[{beta}-{sup 11}C]tryptophan ([{sup 11}C]5-HTP). Both tracers have advantages and disadvantages. [{sup 11}C]AMT can enter the kynurenine pathway under inflammatory conditions (and thus provide a false signal), but this tracer has been used in many studies leading to novel insights regarding antidepressant action. [{sup 11}C]5-HTP is difficult to produce, but trapping of this compound may better represent serotonin synthesis. AMT and 5-HTP kinetics are differently affected by tryptophan depletion and changes of mood. This may indicate that both tracers are associated with different enzymatic processes. In conclusion, PET with radiolabelled substrates for the serotonergic pathway is the only direct way to detect changes of serotonin synthesis in the living brain. (orig.)

Technical considerations on scanning and image analysis for amyloid PET in dementia

International Nuclear Information System (INIS)

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

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. (author)

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.

Radiosynthesis and in vivo evaluation of a series of substituted 11C-phenethylamines as 5-HT (2A) agonist PET tracers

DEFF Research Database (Denmark)

Ettrup, Anders; Hansen, Martin; Santini, Martin A

2011-01-01

Positron emission tomography (PET) imaging of serotonin 2A (5-HT(2A)) receptors with agonist tracers holds promise for the selective labelling of 5-HT(2A) receptors in their high-affinity state. We have previously validated [(11)C]Cimbi-5 and found that it is a 5-HT(2A) receptor agonist PET tracer....... In an attempt to further optimize the target-to-background binding ratio, we modified the chemical structure of the phenethylamine backbone and carbon-11 labelling site of [(11)C]Cimbi-5 in different ways. Here, we present the in vivo validation of nine novel 5-HT(2A) receptor agonist PET tracers in the pig...

Radiosynthesis and in vivo evaluation of a series of substituted 11C-phenethylamines as 5-HT2A agonist PET tracers

DEFF Research Database (Denmark)

Ettrup, Anders; Hansen, Martin; Santini, Martin A

2011-01-01

Positron emission tomography (PET) imaging of serotonin 2A (5-HT(2A)) receptors with agonist tracers holds promise for the selective labelling of 5-HT(2A) receptors in their high-affinity state. We have previously validated [(11)C]Cimbi-5 and found that it is a 5-HT(2A) receptor agonist PET tracer....... In an attempt to further optimize the target-to-background binding ratio, we modified the chemical structure of the phenethylamine backbone and carbon-11 labelling site of [(11)C]Cimbi-5 in different ways. Here, we present the in vivo validation of nine novel 5-HT(2A) receptor agonist PET tracers in the pig...

Dosimetry of ⁶⁴Cu-DOTA-AE105, a PET tracer for uPAR imaging

DEFF Research Database (Denmark)

Persson, Morten; El Ali, Henrik H.; Binderup, Tina

2014-01-01

64Cu-DOTA-AE105 is a novel positron emission tomography (PET) tracer specific to the human urokinase-type plasminogen activator receptor (uPAR). In preparation of using this tracer in humans, as a new promising method to distinguish between indolent and aggressive cancers, we have performed PET......, liver, kidney, spleen, intestine, muscle, bone and bladder. The activity concentrations in the mentioned organs [%ID/g] were used for the dosimetry calculation. The %ID/g of each organ at 1, 4.5 and 22h was scaled to human value based on a difference between organ and body weights. The scaled values...

Preliminary evaluation of MRI-derived input function for quantitative measurement of glucose metabolism in an integrated PET-MRI

International Nuclear Information System (INIS)

Anazodo, Udunna; Kewin, Matthew; Finger, Elizabeth; Thiessen, Jonathan; Hadway, Jennifer; Butler, John; Pavlosky, William; Prato, Frank; Thompson, Terry; St Lawrence, Keith

2015-01-01

PET semi-quantitative methods such as relative uptake value can be robust but offer no biological information and do not account for intra-subject variability in tracer administration or clearance. Simultaneous multimodal measurements that combine PET and MRI not only permit crucial multiparametric measurements, it provides means of applying tracer kinetic modelling without the need for serial arterial blood sampling. In this study we adapted an image-derived input function (IDIF) method to improve characterization of glucose metabolism in an ongoing dementia study. Here we present preliminary results in a small group of frontotemporal dementia patients and controls. IDIF was obtained directly from dynamic PET data guided by regions of interest drawn on carotid vessels on high resolution T1-weighted MR Images. IDIF was corrected for contamination of non-arterial voxels. A validation of the method was performed in a porcine model in a PET-CT scanner comparing IDIF to direct arterial blood samples. Metabolic rate of glucose (CMRglc) was measured voxel-by-voxel in gray matter producing maps that were compared between groups. Net influx rate (Ki) and global mean CMRglc are reported. A good correlation (r = 0.9 p<0.0001) was found between corrected IDIF and input function measured from direct arterial blood sampling in the validation study. In 3 FTD and 3 controls, a trend towards hypometabolism was found in frontal, temporal and parietal lobes similar to significant differences previously reported by other groups. The global mean CMRglc and Ki observed in control subjects are in line with previous reports. In general, kinetic modelling of PET-FDG using an MR-IDIF can improve characterization of glucose metabolism in dementia. This method is feasible in multimodal studies that aim to combine PET molecular imaging with MRI as dynamic PET can be acquired along with multiple MRI measurements.

Preliminary evaluation of MRI-derived input function for quantitative measurement of glucose metabolism in an integrated PET-MRI

Energy Technology Data Exchange (ETDEWEB)

Anazodo, Udunna; Kewin, Matthew [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada); Finger, Elizabeth [Department of Clinical Neurological Sciences, Western University, London, Ontario (Canada); Thiessen, Jonathan; Hadway, Jennifer; Butler, John [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada); Pavlosky, William [Diagnostic Imaging, St Joseph' s Health Care, London, Ontario (Canada); Prato, Frank; Thompson, Terry; St Lawrence, Keith [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada)

2015-05-18

PET semi-quantitative methods such as relative uptake value can be robust but offer no biological information and do not account for intra-subject variability in tracer administration or clearance. Simultaneous multimodal measurements that combine PET and MRI not only permit crucial multiparametric measurements, it provides means of applying tracer kinetic modelling without the need for serial arterial blood sampling. In this study we adapted an image-derived input function (IDIF) method to improve characterization of glucose metabolism in an ongoing dementia study. Here we present preliminary results in a small group of frontotemporal dementia patients and controls. IDIF was obtained directly from dynamic PET data guided by regions of interest drawn on carotid vessels on high resolution T1-weighted MR Images. IDIF was corrected for contamination of non-arterial voxels. A validation of the method was performed in a porcine model in a PET-CT scanner comparing IDIF to direct arterial blood samples. Metabolic rate of glucose (CMRglc) was measured voxel-by-voxel in gray matter producing maps that were compared between groups. Net influx rate (Ki) and global mean CMRglc are reported. A good correlation (r = 0.9 p<0.0001) was found between corrected IDIF and input function measured from direct arterial blood sampling in the validation study. In 3 FTD and 3 controls, a trend towards hypometabolism was found in frontal, temporal and parietal lobes similar to significant differences previously reported by other groups. The global mean CMRglc and Ki observed in control subjects are in line with previous reports. In general, kinetic modelling of PET-FDG using an MR-IDIF can improve characterization of glucose metabolism in dementia. This method is feasible in multimodal studies that aim to combine PET molecular imaging with MRI as dynamic PET can be acquired along with multiple MRI measurements.

Determination of regional flow by use of intravascular PET tracers: microvascular theory and experimental validation for pig livers

DEFF Research Database (Denmark)

Munk, O L; Bass, L; Feng, H

2003-01-01

Today, the standard approach for the kinetic analysis of dynamic PET studies is compartment models, in which the tracer and its metabolites are confined to a few well-mixed compartments. We examine whether the standard model is suitable for modern PET data or whether theories including more...... physiologic realism can advance the interpretation of dynamic PET data. A more detailed microvascular theory is developed for intravascular tracers in single-capillary and multiple-capillary systems. The microvascular models, which account for concentration gradients in capillaries, are validated and compared...... with the standard model in a pig liver study. METHODS: Eight pigs underwent a 5-min dynamic PET study after (15)O-carbon monoxide inhalation. Throughout each experiment, hepatic arterial blood and portal venous blood were sampled, and flow was measured with transit-time flow meters. The hepatic dual...

Clinical utility of FDG-PET for the differential diagnosis among the main forms of dementia.

Science.gov (United States)

Nestor, Peter J; Altomare, Daniele; Festari, Cristina; Drzezga, Alexander; Rivolta, Jasmine; Walker, Zuzana; Bouwman, Femke; Orini, Stefania; Law, Ian; Agosta, Federica; Arbizu, Javier; Boccardi, Marina; Nobili, Flavio; Frisoni, Giovanni Battista

2018-05-07

To assess the clinical utility of FDG-PET as a diagnostic aid for differentiating Alzheimer's disease (AD; both typical and atypical forms), dementia with Lewy bodies (DLB), frontotemporal lobar degeneration (FTLD), vascular dementia (VaD) and non-degenerative pseudodementia. A comprehensive literature search was conducted using the PICO model to extract evidence from relevant studies. An expert panel then voted on six different diagnostic scenarios using the Delphi method. The level of empirical study evidence for the use of FDG-PET was considered good for the discrimination of DLB and AD; fair for discriminating FTLD from AD; poor for atypical AD; and lacking for discriminating DLB from FTLD, AD from VaD, and for pseudodementia. Delphi voting led to consensus in all scenarios within two iterations. Panellists supported the use of FDG-PET for all PICOs-including those where study evidence was poor or lacking-based on its negative predictive value and on the assistance it provides when typical patterns of hypometabolism for a given diagnosis are observed. Although there is an overall lack of evidence on which to base strong recommendations, it was generally concluded that FDG-PET has a diagnostic role in all scenarios. Prospective studies targeting diagnostically uncertain patients for assessing the added value of FDG-PET would be highly desirable.

Recommendations for the use of PET imaging biomarkers in the diagnosis of neurodegenerative conditions associated with dementia: SEMNIM and SEN consensus.

Science.gov (United States)

Arbizu, Javier; García-Ribas, Guillermo; Carrió, Ignasi; Garrastachu, Puy; Martínez-Lage, Pablo; Molinuevo, José Luis

2015-01-01

The new diagnostic criteria for Alzheimer's disease (AD) acknowledges the interest given to biomarkers to improve the specificity in subjects with dementia and to facilitate an early diagnosis of the pathophysiological process of AD in the prodromal or pre-dementia stage. The current availability of PET imaging biomarkers of synaptic dysfunction (PET-FDG) and beta amyloid deposition using amyloid-PET provides clinicians with the opportunity to apply the new criteria and improve diagnostic accuracy in their clinical practice. Therefore, it seems essential for the scientific societies involved to use the new clinical diagnostic support tools to establish clear, evidence-based and agreed set of recommendations for their appropriate use. The present work includes a systematic review of the literature on the utility of FDG-PET and amyloid-PET for the diagnosis of AD and related neurodegenerative diseases that occur with dementia. Thus, we propose a series of recommendations agreed on by the Spanish Society of Nuclear Medicine and Spanish Society of Neurology as a consensus statement on the appropriate use of PET imaging biomarkers. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

PET and SPECT investigations in Alzheimer's disease

International Nuclear Information System (INIS)

Asenbaum, S.

2003-01-01

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

Comparison of multiple tau-PET measures as biomarkers in aging and Alzheimer's disease

Energy Technology Data Exchange (ETDEWEB)

Maass, Anne [Univ. of California, Berkeley, CA (United States); German Center for Neurodegenerative Diseases, Magdeburg (Germany); Landau, Susan [Univ. of California, Berkeley, CA (United States); Baker, Suzanne L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Horng, Andy [Univ. of California, Berkeley, CA (United States); Lockhart, Samuel N. [Univ. of California, Berkeley, CA (United States); La Joie, Renaud [Univ. of California, San Francisco, CA (United States); Rabinovici, Gil D. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, San Francisco, CA (United States); Jagust, William J. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, San Francisco, CA (United States)

2017-06-03

The recent development of tau-specific positron emission tomography (PET) tracers enables in vivo quantification of regional tau pathology, one of the key lesions in Alzheimer's disease (AD). Tau PET imaging may become a useful biomarker for clinical diagnosis and tracking of disease progression but there is no consensus yet on how tau PET signal is best quantified. The goal of the current paper was to evaluate multiple whole-brain and region-specific approaches to detect clinically relevant tau PET signal. Two independent cohorts of cognitively normal adults and amyloid-positive (Aβ⁺) patients with mild cognitive impairment (MCI) or AD-dementia underwent [¹⁸F]AV-1451 PET. Methods for tau tracer quantification included: (i) in vivo Braak staging, (ii) regional uptake in Braak composite regions, (iii) several whole-brain measures of tracer uptake, (iv) regional uptake in AD-vulnerable voxels, and (v) uptake in a priori defined regions. Receiver operating curves characterized accuracy in distinguishing Aβ^- controls from AD/MCI patients and yielded tau positivity cutoffs. Clinical relevance of tau PET measures was assessed by regressions against cognition and MR imaging measures. Key tracer uptake patterns were identified by a factor analysis and voxel-wise contrasts. Braak staging, global and region-specific tau measures yielded similar diagnostic accuracies, which differed between cohorts. While all tau measures were related to amyloid and global cognition, memory and hippocampal/entorhinal volume/thickness were associated with regional tracer retention in the medial temporal lobe. Key regions of tau accumulation included medial temporal and inferior/middle temporal regions, retrosplenial cortex, and banks of the superior temporal sulcus. Finally, our data indicate that whole-brain tau PET measures might be adequate biomarkers to detect AD-related tau pathology. However, regional measures covering AD-vulnerable regions may

Preclinical tools in PET-tracer development : automatisation and biopharmaceutical evaluation with special emphasis on the adenosine A3 receptor

International Nuclear Information System (INIS)

Haeusler, D. I. B.

2010-01-01

Positron Emission Tomography (PET) is the first choice technology for the visualization and quantification of receptors and transporters, enabling examination of e.g. neurological, psychiatric and oncological diseases on a molecular level. Therefore, new and innovative PET-radiopharmaceuticals need to be developed to get further insights into the biochemical mechanisms involved in pathological changes. PET-tracer development starts with the idea or modelling of the chemical structure of a (new) molecule with (hopefully) good binding characteristics to the desired target site. As next steps, the compound needs to be synthesized and radiolabelled with a suitable PET-nuclide. Then it has to be evaluated regarding its parameters in various preclinical experimental settings. Hence, two major tools are crucial in the development-process of new PET-tracers: 1) a fast and reliable production method, most desirable and optimal in an automated set-up, and 2) proof of tracer suitability (high affinity, high selectivity and specificity, beside low unspecific binding) through preclinical evaluation in an animal model, prior to human application. Both aspects, the radiochemical preparation and automatisation, as well as the biopharmaceutical evaluation are presented in the thesis in 5 different manuscripts. In detail, the development and preclinical evaluation of 4 different PET-tracers ([11C]DASB, [18F]FE SUPPY, [18F]FE SUPPY:2, and [18F]FE CIT) for 3 targets, the serotonin transporter (SERT), the adenosine A3 receptor (A3R) and the dopamine transporter (DAT), respectively, are covered in the present thesis. The first manuscript presents a method for a fast, reliable and fully-automated radiosynthesis of [11C]DASB (a tracer for the imaging of the SERT in human brain in e.g. depression patients) will facilitate further clinical investigations (e.g. for the department of psychiatry and psychotherapy of the medical university of Vienna) with this tracer. [18F]FE SUPPY was

Application of 18F-FDG PET for the diagnosis and differential diagnosis of Alzheimer's disease and Lewy body dementia

International Nuclear Information System (INIS)

Klisarova, A.; Bochev, P.; Deleva, N.; Dimitrov, I.; Ivanov, B.

2010-01-01

Alzheimer's disease and Lewy body dementia are the two most frequent disorders among degenerative dementias. Their clinical identification and differential diagnosis are often difficult in the early stages when, on the other hand treatment is most effective. FDG-PET assessment of region brain metabolism is a proven method and its application demented patients ensures a higher diagnostic accuracy even at the preclinical stage. It helps resolving cases with difficult differential diagnosis as well. In this paper we discuss the application of the method in Alzheimer's disease and Lev body dementia; we present typical cases of both disorder which were assessed by FDG-PET for the first time in Bulgaria highlighting the methodology and the characteristic imaging findings

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-11-15

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

Limbic system, the main focus of dementia syndrome; A study with MRI and PET

Energy Technology Data Exchange (ETDEWEB)

Matsuzawa, Taiju [Morinosato Hospital, Atsugi, Kanagawa (Japan)

1990-12-01

Alzheimer disease and multi-infarct dementia are two entirely different diseases producing almost the same abnormalities as dementia syndrome. The statistical studies with MRI to locate the focus of dementia syndrome in the neocortex was an absolute failure. With MRI there is drastic atrophy and destruction of the amygdala and hippocampus suggesting the limbic system as the focus of dementia syndrome. Destruction of the limbic system in particular amygdala and hippocampus produced the functional obstruction brought about by the marked reduction in the glucose utilization with PET in the bilateral temporal, parietal and occipital association cortices. Although this type constitutes only about 1/5 of all dementia patients. It is considered the fundamental type of dementia syndrome. Aside from this, there is a type wherein simultaneous and symmetrical reductions in glucose utilization of the frontal association cortex and the motor association cortex in the anterior part of the neocortex. This is referred to as type II. It constitutes about 4/5 of all dementia patients which is far more than type I. Based on these results, it is thought that limbic system is the main focus of dementia syndrome. (author).

Atmospheric tracer study of the emissions from the University of Michigan Cyclotron/PET Facility

International Nuclear Information System (INIS)

Scofield, P.A.

1986-01-01

The University of Michigan (U of M) Cyclotron/Positron Emission Tomography (PET) facility consists of a cyclotron (Model CS-30, The Cyclotron Corporation), radiochemistry laboratory, and Pet scanner. Accelerator-produced radioactive materials, such as, carbon-11 and oxygen-15 are typically emitted from the Cyclotron/PET facility through short stacks located on the roof. This project studied the dispersion of emissions from the facility within the medical complex. To achieve this purpose, the research project had three phases: a physical modeling study; a preliminary field smoke release study; and, a field study using a tracer gas to simulate emission dispersion from the U of M Cyclotron/PET facility vault stack. The objective was to determine normalized concentrations, under selected wind directions and speeds, for use in establishing radionuclide concentrations at the air intakes of the Cyclotron/PET facility and surrounding buildings and at selected ground-level locations

Biodistribution of [11C] methylaminoisobutyric acid, a tracer for PET studies on system A amino acid transport in vivo

International Nuclear Information System (INIS)

Sutinen, E.; Jyrkkioe, S.; Groenroos, T.; Haaparanta, M.; Lehikoinen, P.; Naagren, K.

2001-01-01

[N-methyl- 11 C]α-Methylaminoisobutyric acid ( 11 C-MeAIB) is a potentially useful tracer for positron emission tomography (PET) studies on hormonally regulated system A amino acid transport. 11 C-MeAIB is a metabolically stable amino acid analogue specific for system A amino acid transport. We evaluated the biodistribution of 11 C-MeAIB in rats and humans to estimate the usefulness of the tracer for in vivo human PET studies, for example, on regulation of system A amino acid transport and on tumour imaging. Healthy Sprague-Dawley rats (n=14) were killed 5, 20, 40 or 60 min after the injection of 11 C-MeAIB, and the tissue samples were weighed and counted for 11 C radioactivity. Ten lymphoma patients with relatively limited tumour burden underwent whole-body (WB) PET imaging with 11 C-MeAIB. In addition, three other patients had dynamic PET scanning of the head and neck area, and the tracer uptake was quantitated by calculating the kinetic influx constants (K i values) for the tracer. In animal studies, the highest activity was detected in the kidney, pancreas, adrenal gland and intestines. In humans, the highest activity was found in the salivary glands, and after that in the kidney and pancreas, similar to the results in animal studies. Rapid uptake was also detected in the skeletal muscle. In the graphical analysis, linear plots were obtained, and the mean fractional tracer uptake values (K i ) of the parotid glands (n=3) and cervical muscles (n=3) were 0.039±0.008 min -1 and 0.013±0.006 min -1 , respectively. The K i value of the tumour (n=1) was 0.064 min -1 . Higher uptake of 11 C-MeAIB into the tumour tissue was encountered. These results encourage further 11 C-MeAIB PET studies in humans on the physiology and pathology of system A amino acid transport and on tumour detection. (orig.)

In-vivo measurements of regional acetylcholine esterase activity in degenerative dementia: comparison with blood flow and glucose metabolism.

Science.gov (United States)

Herholz, K; Bauer, B; Wienhard, K; Kracht, L; Mielke, R; Lenz, M O; Strotmann, T; Heiss, W D

2000-01-01

Memory and attention are cognitive functions that depend heavily on the cholinergic system. Local activity of acetylcholine esterase (AChE) is an indicator of its integrity. Using a recently developed tracer for positron emission tomography (PET), C-11-labeled N-methyl-4-piperidyl-acetate (C11-MP4A), we measured regional AChE activity in 4 non-demented subjects, 4 patients with dementia of Alzheimer type (DAT) and 1 patient with senile dementia of Lewy body type (SDLT), and compared the findings with measurements of blood flow (CBF) and glucose metabolism (CMRGlc). Initial tracer extraction was closely related to CBF. AChE activity was reduced significantly in all brain regions in demented subjects, whereas reduction of CMRGlc and CBF was more limited to temporo-parietal association areas. AChE activity in SDLT was in the lower range of values in DAT. Our results indicate that, compared to non-demented controls, there is a global reduction of cortical AChE activity in dementia. Dementia, cholinergic system, acetylcholine esterase, positron emission tomography, cerebral blood flow, cerebral glucose metabolism.

[18F]Fluoroethylflumazenil: a novel tracer for PET imaging of human benzodiazepine receptors

International Nuclear Information System (INIS)

Gruender, G.; Lange-Asschenfeldt, C.; Vernaleken, I.; Lueddens, H.; Siessmeier, T.; Buchholz, H.-G.; Bartenstein, P.; Stoeter, P.; Drzezga, A.; Roesch, F.

2001-01-01

5-(2'-[ 18 F]Fluoroethyl)flumazenil ([ 18 F]FEF) is a fluorine-18 labelled positron emission tomography (PET) tracer for central benzodiazepine receptors. Compared with the established [ 11 C]flumazenil, it has the advantage of the longer half-life of the fluorine-18 label. After optimisation of its synthesis and determination of its in vitro receptor affinities, we performed first PET studies in humans. PET studies in seven healthy human volunteers were performed on a Siemens ECAT EXACT whole-body scanner after injection of 100-280 MBq [ 18 F]FEF. In two subjects, a second PET scan was conducted after pretreatment with unlabelled flumazenil (1 mg or 2.5 mg i.v., 3 min before tracer injection). A third subject was studied both with [ 18 F]FEF and with [ 11 C]flumazenil. Brain radioactivity was measured for 60-90 min p.i. and analysed with a region of interest-oriented approach and on a voxelwise basis with spectral analysis. Plasma radioactivity was determined from arterial blood samples and metabolites were determined by high-performance liquid chromatography. In human brain, maximum radioactivity accumulation was observed 4±2 min p.i., with a fast clearance kinetics resulting in 50% and 20% of maximal activities at about 10 and 30 min, respectively. [ 18 F]FEF uptake followed the known central benzodiazepine receptor distribution in the human brain (occipital cortex >temporal cortex >cerebellum >thalamus >pons). Pretreatment with unlabelled flumazenil resulted in reduced tracer uptake in all brain areas except for receptor-free reference regions like the pons. Parametric images of distribution volume and binding potential generated on a voxelwise basis revealed two- to three-fold lower in vivo receptor binding of [ 18 F]FEF compared with [ 11 C]flumazenil, while relative uptake of [ 18 F]FEF was higher in the cerebellum, most likely owing to its relatively higher affinity for benzodiazepine receptors containing the α6 subunit. Metabolism of [ 18 F]FEF was very

Imaging in-vivo tau pathology in Alzheimer's disease with THK5317 PET in a multimodal paradigm

International Nuclear Information System (INIS)

Chiotis, Konstantinos; Saint-Aubert, Laure; Savitcheva, Irina; Jelic, Vesna; Andersen, Pia; Jonasson, My; Eriksson, Jonas; Antoni, Gunnar; Lubberink, Mark; Almkvist, Ove; Wall, Anders; Nordberg, Agneta

2016-01-01

The aim of this study was to explore the cerebral distribution of the tau-specific PET tracer [ 18 F]THK5317 (also known as (S)-[ 18 F]THK5117) retention in different stages of Alzheimer's disease; and study any associations with markers of hypometabolism and amyloid-beta deposition. Thirty-three individuals were enrolled, including nine patients with Alzheimer's disease dementia, thirteen with mild cognitive impairment (MCI), two with non-Alzheimer's disease dementia, and nine healthy controls (five young and four elderly). In a multi-tracer PET design [ 18 F]THK5317, [ 11 C] Pittsburgh compound B ([ 11 C]PIB), and [ 18 F]FDG were used to assess tau pathology, amyloid-beta deposition and cerebral glucose metabolism, respectively. The MCI patients were further divided into MCI [ 11 C]PIB-positive (n = 11) and MCI [ 11 C]PIB-negative (n = 2) groups. Test-retest variability for [ 18 F]THK5317-PET was very low (1.17-3.81 %), as shown by retesting five patients. The patients with prodromal (MCI [ 11 C]PIB-positive) and dementia-stage Alzheimer's disease had significantly higher [ 18 F]THK5317 retention than healthy controls (p = 0.002 and p = 0.001, respectively) in areas exceeding limbic regions, and their discrimination from this control group (using the area under the curve) was >98 %. Focal negative correlations between [ 18 F]THK5317 retention and [ 18 F]FDG uptake were observed mainly in the frontal cortex, and focal positive correlations were found between [ 18 F]THK5317 and [ 11 C]PIB retentions isocortically. One patient with corticobasal degeneration syndrome and one with progressive supranuclear palsy showed no [ 11 C]PIB but high [ 18 F]THK5317 retentions with a different regional distribution from that in Alzheimer's disease patients. The tau-specific PET tracer [ 18 F]THK5317 images in vivo the expected regional distribution of tau pathology. This distribution contrasts with the different patterns of hypometabolism and amyloid

18F PET with florbetaben for the early diagnosis of Alzheimer's disease dementia and other dementias in people with mild cognitive impairment (MCI).

Science.gov (United States)

Martínez, Gabriel; Vernooij, Robin Wm; Fuentes Padilla, Paulina; Zamora, Javier; Flicker, Leon; Bonfill Cosp, Xavier

2017-11-22

18 F-florbetaben uptake by brain tissue, measured by positron emission tomography (PET), is accepted by regulatory agencies like the Food and Drug Administration (FDA) and the European Medicine Agencies (EMA) for assessing amyloid load in people with dementia. Its added value is mainly demonstrated by excluding Alzheimer's pathology in an established dementia diagnosis. However, the National Institute on Aging and Alzheimer's Association (NIA-AA) revised the diagnostic criteria for Alzheimer's disease and confidence in the diagnosis of mild cognitive impairment (MCI) due to Alzheimer's disease may be increased when using some amyloid biomarkers tests like 18 F-florbetaben. These tests, added to the MCI core clinical criteria, might increase the diagnostic test accuracy (DTA) of a testing strategy. However, the DTA of 18 F-florbetaben to predict the progression from MCI to Alzheimer's disease dementia (ADD) or other dementias has not yet been systematically evaluated. To determine the DTA of the 18 F-florbetaben PET scan for detecting people with MCI at time of performing the test who will clinically progress to ADD, other forms of dementia (non-ADD), or any form of dementia at follow-up. The most recent search for this review was performed in May 2017. We searched MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP), BIOSIS Citation Index (Thomson Reuters Web of Science), Web of Science Core Collection, including the Science Citation Index (Thomson Reuters Web of Science) and the Conference Proceedings Citation Index (Thomson Reuters Web of Science), LILACS (BIREME), CINAHL (EBSCOhost), ClinicalTrials.gov (https://clinicaltrials.gov), and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) (http://www.who.int/ictrp/search/en/). We also searched ALOIS, the Cochrane Dementia & Cognitive Improvement Group's specialised register of dementia studies (http://www.medicine.ox.ac.uk/alois/). We checked the reference lists of any

Validating PET segmentation of thoracic lesions-is 4D PET necessary?

DEFF Research Database (Denmark)

Nielsen, M. S.; Carl, J.

2017-01-01

Respiratory-induced motions are prone to degrade the positron emission tomography (PET) signal with the consequent loss of image information and unreliable segmentations. This phantom study aims to assess the discrepancies relative to stationary PET segmentations, of widely used semiautomatic PET...... segmentation methods on heterogeneous target lesions influenced by motion during image acquisition. Three target lesions included dual F-18 Fluoro-deoxy-glucose (FDG) tracer concentrations as high-and low tracer activities relative to the background. Four different tracer concentration arrangements were...... segmented using three SUV threshold methods (Max40%, SUV40% and 2.5SUV) and a gradient based method (GradientSeg). Segmentations in static 3D-PET scans (PETsta) specified the reference conditions for the individual segmentation methods, target lesions and tracer concentrations. The motion included PET...

Heart PET scan

Science.gov (United States)

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

Apathy in patients with Parkinson disease without dementia or depression: a PET study.

Science.gov (United States)

Robert, Gabriel; Le Jeune, Florence; Lozachmeur, Clément; Drapier, Sophie; Dondaine, Thibault; Péron, Julie; Travers, David; Sauleau, Paul; Millet, Bruno; Vérin, Marc; Drapier, Dominique

2012-09-11

We sought to identify apathy metabolic bases in Parkinson disease (PD). A total of 45 patients with PD who were not clinically depressed (Montgomery-Åsberg Depression Rating Scale [MADRS] dementia (Mattis Dementia Rating Scale [MDRS] >130) were assessed with the Apathy Evaluation Scale (AES) and underwent a resting-state F-18 fluorodeoxyglucose PET (FDG-PET) scan. A motor assessment comprising the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) was conducted and total levodopa equivalent daily dose (LEDD) was calculated. Imaging data were analyzed with statistical parametric mapping. Age, LEDD, and MDRS scores were introduced as covariates. Positive correlations were observed between the AES score and cerebral metabolism in the right inferior frontal gyrus (Brodmann area [BA] 47), right middle frontal gyrus (BA 10), right cuneus (BA 18), and right anterior insula (BA 13). Negative correlations were observed between the AES score and cerebellar metabolism in the semilunar lobules bilaterally, within the posterior lobe. Using an AES score equal to or above 42 to define clinical apathy, prevalence in our patient group was 17.8%. The AES score was negatively correlated with the MDRS score and positively correlated with the "retardation" subscore of the MADRS. It was not correlated with either UPDRS III or LEDD. Results indicate that the frontal, temporal, and cerebellar areas known to be involved in reward, emotion, and cognition are also implicated in apathy in patients with PD without dementia or depression. Their roles in the etiopathology of apathy are discussed.

Comparison of conventional and novel PET tracers for imaging mesothelioma in nude mice with subcutaneous and intrapleural xenografts

Energy Technology Data Exchange (ETDEWEB)

Tsuji, Atsushi B.; Sogawa, Chizuru; Sugyo, Aya [Diagnostic Imaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Sudo, Hitomi [Diagnostic Imaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Department of Pathology and Oncology, Juntendo University School of Medicine, Tokyo, 113-8421 (Japan); Toyohara, Jun [Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, 206-8670 (Japan); Koizumi, Mitsuru [Diagnostic Imaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Abe, Masaaki; Hino, Okio [Department of Pathology and Oncology, Juntendo University School of Medicine, Tokyo, 113-8421 (Japan); Harada, Yoshi-nobu; Furukawa, Takako [Diagnostic Imaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Suzuki, Kazutoshi [Molecular Probe Group, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Saga, Tsuneo [Diagnostic Imaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan)], E-mail: saga@nirs.go.jp

2009-05-15

Introduction: Malignant mesothelioma is a highly aggressive tumor originating in the pleura, peritoneum and pericardium, and the prognosis of patients undergoing current treatment remains poor. To develop new therapies, it is important to have a noninvasive imaging system for evaluating the efficacy of such prospective treatments. We have established clinically relevant mouse models and evaluated conventional and novel positron emission tomography (PET) tracers. Methods: Epithelioid and sarcomatoid mesothelioma cells were inoculated subcutaneously and intrapleurally into nude mice. Biodistribution and PET imaging studies were conducted by injecting [{sup 18}F]fluoro-2-deoxy-D-glucose (FDG), 3'-[{sup 18}F]fluoro-3'-doxythymidine (FLT) or 4'-methyl-[{sup 11}C]thiothymidine (S-dThd) into the mouse models. In vitro cellular uptake of [{sup 14}C]FDG and [{sup 3}H]FLT and thymidine kinase 1 (TK{sub 1}) activity in both cell lines were measured. Expression of glucose transporter 1 (GLUT-1) and Ki-67 in xenografted tumors was evaluated by immunohistochemical staining. Results: In epithelioid mesothelioma models, biodistribution experiments showed that tumor uptake of [{sup 11}C]S-dThd was significantly higher than that of [{sup 18}F]FDG. On the other hand, in sarcomatoid models, [{sup 18}F]FDG showed significantly higher accumulation than the other two tracers. These differential uptakes of the three tracers were confirmed by PET imaging. The cellular uptake of [{sup 14}C]FDG and [{sup 3}H]FLT and TK{sub 1} activity in sarcomatoid cells were higher than those of epithelioid cells. GLUT-1 protein was strongly expressed in sarcomatoid but not in epithelioid tumor. We observed a high percentage of Ki-67-positive cells in both epithelioid and sarcomatoid tumors. Conclusions: We established nude mouse models of epithelioid and sarcomatoid subtypes of mesothelioma. PET tracers applicable for the evaluation of epithelioid and sarcomatoid mesothelioma would vary

Current status and future role of brain PET/MRI in clinical and research settings

Energy Technology Data Exchange (ETDEWEB)

Werner, P.; Barthel, H.; Sabri, O. [University Hospital Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Drzezga, A. [University Hospital Cologne, Department of Nuclear Medicine, Koeln (Germany)

2015-01-09

Hybrid PET/MRI systematically offers a complementary combination of two modalities that has often proven itself superior to the single modality approach in the diagnostic work-up of many neurological and psychiatric diseases. Emerging PET tracers, technical advances in multiparametric MRI and obvious workflow advantages may lead to a significant improvement in the diagnosis of dementia disorders, neurooncological diseases, epilepsy and neurovascular diseases using PET/MRI. Moreover, simultaneous PET/MRI is well suited to complex studies of brain function in which fast fluctuations of brain signals (e.g. related to task processing or in response to pharmacological interventions) need to be monitored on multiple levels. Initial simultaneous studies have already demonstrated that these complementary measures of brain function can provide new insights into the functional and structural organization of the brain. (orig.)

Current status and future role of brain PET/MRI in clinical and research settings

International Nuclear Information System (INIS)

Werner, P.; Barthel, H.; Sabri, O.; Drzezga, A.

2015-01-01

Hybrid PET/MRI systematically offers a complementary combination of two modalities that has often proven itself superior to the single modality approach in the diagnostic work-up of many neurological and psychiatric diseases. Emerging PET tracers, technical advances in multiparametric MRI and obvious workflow advantages may lead to a significant improvement in the diagnosis of dementia disorders, neurooncological diseases, epilepsy and neurovascular diseases using PET/MRI. Moreover, simultaneous PET/MRI is well suited to complex studies of brain function in which fast fluctuations of brain signals (e.g. related to task processing or in response to pharmacological interventions) need to be monitored on multiple levels. Initial simultaneous studies have already demonstrated that these complementary measures of brain function can provide new insights into the functional and structural organization of the brain. (orig.)

Complementary roles of tumour specific PET tracer {sup 18}F-FAMT to {sup 18}F-FDG PET/CT for the assessment of bone metastasis

Energy Technology Data Exchange (ETDEWEB)

Morita, Motoho [Gunma University Hospital, Department of General Medicine, Maebashi, Gunma (Japan); Gunma University Graduate School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Maebashi, Gunma (Japan); Higuchi, Tetsuya; Tokue, Azusa; Arisaka, Yukiko; Tsushima, Yoshito [Gunma University Graduate School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Maebashi, Gunma (Japan); Achmad, Arifudin [Gunma University Graduate School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Maebashi, Gunma (Japan); Gadjah Mada University, Department of Radiology, Faculty of Medicine, Yogyakarta (Indonesia)

2013-10-15

The usefulness of {sup 18}F-FDG PET/CT for bone metastasis evaluation has already been established. The amino acid PET tracer [{sup 18}F]-3-fluoro-alpha-methyl tyrosine ({sup 18}F-FAMT) has been reported to be highly specific for malignancy. We evaluated the additional value of {sup 18}F-FAMT PET/CT to complement {sup 18}F-FDG PET/CT in the evaluation of bone metastasis. This retrospective study included 21 patients with bone metastases of various cancers who had undergone both {sup 18}F-FDG and {sup 18}F-FAMT PET/CT within 1 month of each other. {sup 18}F-FDG-avid bone lesions suspicious for malignancy were carefully selected based on the cut-off value for malignancy, and the SUVmax of the {sup 18}F-FAMT in the corresponding lesions were evaluated. A total of 72 {sup 18}F-FDG-positive bone lesions suspected to be metastases in the 21 patients were used as the reference standard. {sup 18}F-FAMT uptake was found in 87.5 % of the lesions. In the lesions of lung cancer origin, the uptake of the two tracers showed a good correlation (40 lesions, r = 0.68, P < 0.01). Bone metastatic lesions of oesophageal cancer showed the highest average of {sup 18}F-FAMT uptake. Bone metastatic lesions of squamous cell carcinoma showed higher {sup 18}F-FAMT uptake than those of adenocarcinoma. No significant difference in {sup 18}F-FAMT uptake was seen between osteoblastic and osteolytic bone metastatic lesions. The usefulness of {sup 18}F-FAMT PET/CT for bone metastasis detection regardless of the lesion phenotype was demonstrated. The fact that {sup 18}F-FAMT uptake was confirmed by {sup 18}F-FDG uptake suggests that {sup 18}F-FAMT PET/CT has the potential to complement {sup 18}F-FDG PET/CT for the detection of bone metastases. (orig.)

Multi-tracer small animal PET imaging of the tumour response to the novel pan-Erb-B inhibitor CI-1033

International Nuclear Information System (INIS)

Dorow, Donna S.; Cullinane, Carleen; Conus, Nelly; Roselt, Peter; Binns, David; McCarthy, Timothy J.; McArthur, Grant A.; Hicks, Rodney J.

2006-01-01

This study was designed as ''proof of concept'' for a drug development model utilising multi-tracer serial small animal PET imaging to characterise tumour responses to molecularly targeted therapy. Mice bearing subcutaneous A431 human squamous carcinoma xenografts (n=6-8) were treated with the pan-Erb-B inhibitor CI-1033 or vehicle and imaged serially (days 0, 3 and 6 or 7) with [ 18 F]fluorodeoxyglucose, [ 18 F]fluoro-L-thymidine, [ 18 F]fluoro-azoazomycinarabinoside or [ 18 F]fluoromisonidazole. Separate cohorts (n=3) were treated identically and tumours were assessed ex vivo for markers of glucose metabolism, proliferation and hypoxia. During the study period, mean uptake of all PET tracers generally increased for control tumours compared to baseline. In contrast, tracer uptake into CI-1033-treated tumours decreased by 20-60% during treatment. Expression of the glucose transporter Glut-1 and cell cycle markers was unchanged or increased in control tumours and generally decreased with CI-1033 treatment, compared to baseline. Thymidine kinase activity was reduced in all tumours compared to baseline at day 3 but was sevenfold higher in control versus CI-1033-treated tumours by day 6 of treatment. Uptake of the hypoxia marker pimonidazole was stable in control tumours but was severely reduced following 7 days of CI-1033 treatment. CI-1033 treatment significantly affects tumour metabolism, proliferation and hypoxia as determined by PET. The PET findings correlated well with ex vivo biomarkers for each of the cellular processes studied. These results confirm the utility of small animal PET for evaluation of the effectiveness of molecularly targeted therapies and simultaneously definition of specific cellular processes involved in the therapeutic response. (orig.)

Development of a Widely Usable Amino Acid Tracer: ⁷⁶Br-α-Methyl-Phenylalanine for Tumor PET Imaging.

Science.gov (United States)

Hanaoka, Hirofumi; Ohshima, Yasuhiro; Suzuki, Yurika; Yamaguchi, Aiko; Watanabe, Shigeki; Uehara, Tomoya; Nagamori, Shushi; Kanai, Yoshikatsu; Ishioka, Noriko S; Tsushima, Yoshito; Endo, Keigo; Arano, Yasushi

2015-05-01

Radiolabeled amino acids are superior PET tracers for the imaging of malignant tumors, and amino acids labeled with (76)Br, an attractive positron emitter because of its relatively long half-life (16.2 h), could potentially be a widely usable tumor imaging tracer. In this study, in consideration of its stability and tumor specificity, we designed two (76)Br-labeled amino acid derivatives, 2-(76)Br-bromo-α-methyl-l-phenylalanine (2-(76)Br-BAMP) and 4-(76)Br-bromo-α-methyl-l-phenylalanine (4-(76)Br-BAMP), and investigated their potential as tumor imaging agents. Both (76)Br- and (77)Br-labeled amino acid derivatives were prepared. We performed in vitro and in vivo stability studies and cellular uptake studies using the LS180 colon adenocarcinoma cell line. Biodistribution studies in normal mice and in LS180 tumor-bearing mice were performed, and the tumors were imaged with a small-animal PET scanner. Both (77)Br-BAMPs were stable in the plasma and in the murine body. Although both (77)Br-BAMPs were taken up by LS180 cells and the uptake was inhibited by L-type amino acid transporter 1 inhibitors, 2-(77)Br-BAMP exhibited higher uptake than 4-(77)Br-BAMP. In the biodistribution studies, 2-(77)Br-BAMP showed more rapid blood clearance and lower renal accumulation than 4-(77)Br-BAMP. More than 90% of the injected radioactivity was excreted in the urine by 6 h after the injection of 2-(77)Br-BAMP. High tumor accumulation of 2-(77)Br-BAMP was observed in tumor-bearing mice, and PET imaging with 2-(76)Br-BAMP enabled clear visualization of the tumors. 2-(77)Br-BAMP exhibited preferred pharmacokinetics and high LS180 tumor accumulation, and 2-(76)Br-BAMP enabled clear visualization of the tumors by PET imaging. These findings suggest that 2-(76)Br-BAMP could constitute a potential new PET tracer for tumor imaging and may eventually enable the wider use of amino acid tracers. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

(18)F-FDG dynamic PET/CT in patients with multiple myeloma: patterns of tracer uptake and correlation with bone marrow plasma cell infiltration rate.

Science.gov (United States)

Sachpekidis, Christos; Mai, Elias K; Goldschmidt, Hartmut; Hillengass, Jens; Hose, Dirk; Pan, Leyun; Haberkorn, Uwe; Dimitrakopoulou-Strauss, Antonia

2015-06-01

The value of F-FDG PET in the diagnostic approach of multiple myeloma (MM) remains incompletely elicited. Little is known about the kinetics of F-FDG in the bone marrow and extramedullary sites in MM. This study aimed to evaluate quantitative data on kinetics and distribution patterns of F-FDG in MM patients with regard to pelvic bone marrow plasma cell infiltration. The study included 40 patients with primary MM. Dynamic PET/CT scanning of the lower lumbar spine and pelvis was performed after the administration of F-FDG. Whole-body PET/CT studies were performed. Sites of focal increased tracer uptake were considered as highly suggestive of myelomatous involvement after taking into account the patient history and CT findings. Bone marrow of the os ilium without pathologic tracer accumulation served as reference. The evaluation of dynamic PET/CT studies was based in addition to the conventional visual (qualitative) assessment, on semiquantitative (SUV) calculations, as well as on absolute quantitative estimations after application of a 2-tissue compartment model and a noncompartmental approach. F-FDG quantitative information and corresponding distribution patterns were correlated with pelvic bone marrow plasma cell infiltration. Fifty-two myelomatous lesions were detected in the pelvis. All parameters in suspected MM lesions ranged in significantly higher levels than in reference tissue (P PET/CT imaging demonstrated 4 patterns of tracer uptake; these are as follows: negative, focal, diffuse, and mixed (focal/diffuse) tracer uptake. Patients with a mixed pattern of radiotracer uptake had the highest mean plasma cell infiltration rate in their bone marrow, whereas those with negative PET/CT scans demonstrated the lowest bone marrow plasma cell infiltration. In total, 265 focal myeloma-indicative F-FDG-avid lesions were detected, 129 of which correlated with low-dose CT osteolytic findings. No significant correlation between the number of focal lesions detected in PET

Arterial spin labeling-based Z-maps have high specificity and positive predictive value for neurodegenerative dementia compared to FDG-PET

Energy Technology Data Exchange (ETDEWEB)

Faellmar, David; Larsson, Elna-Marie [Uppsala University, Department of Surgical Sciences, Radiology, Uppsala (Sweden); Haller, Sven [Uppsala University, Department of Surgical Sciences, Radiology, Uppsala (Sweden); University Medical Center Freiburg, Department of Neuroradiology, Freiburg (Germany); University of Geneva, Faculty of Medicine, Geneva (Switzerland); Affidea CDRC - Centre Diagnostique Radiologique de Carouge, Carouge (Switzerland); Lilja, Johan [Uppsala University, Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala (Sweden); Hermes Medical Solutions, Stockholm (Sweden); Danfors, Torsten [Uppsala University, Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala (Sweden); Kilander, Lena [Uppsala University, Department of Public Health and Caring Sciences, Geriatrics, Uppsala (Sweden); Tolboom, Nelleke; Croon, Philip M.; Berckel, Bart N.M. van [VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Egger, Karl [University Medical Center Freiburg, Department of Neuroradiology, Freiburg (Germany); Kellner, Elias [Medical Center University of Freiburg, Department of Radiology, Medical Physics, Faculty of Medicine, Freiburg (Germany); Verfaillie, Sander C.J.; Ossenkoppele, Rik [VU University Medical Center, Department of Neurology, Alzheimer Center Amsterdam, Amsterdam (Netherlands); Barkhof, Frederik [VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); UCL, Institutes of Neurology and Healthcare Engineering, London (United Kingdom)

2017-10-15

Cerebral perfusion analysis based on arterial spin labeling (ASL) MRI has been proposed as an alternative to FDG-PET in patients with neurodegenerative disease. Z-maps show normal distribution values relating an image to a database of controls. They are routinely used for FDG-PET to demonstrate disease-specific patterns of hypometabolism at the individual level. This study aimed to compare the performance of Z-maps based on ASL to FDG-PET. Data were combined from two separate sites, each cohort consisting of patients with Alzheimer's disease (n = 18 + 7), frontotemporal dementia (n = 12 + 8) and controls (n = 9 + 29). Subjects underwent pseudocontinuous ASL and FDG-PET. Z-maps were created for each subject and modality. Four experienced physicians visually assessed the 166 Z-maps in random order, blinded to modality and diagnosis. Discrimination of patients versus controls using ASL-based Z-maps yielded high specificity (84%) and positive predictive value (80%), but significantly lower sensitivity compared to FDG-PET-based Z-maps (53% vs. 96%, p < 0.001). Among true-positive cases, correct diagnoses were made in 76% (ASL) and 84% (FDG-PET) (p = 0.168). ASL-based Z-maps can be used for visual assessment of neurodegenerative dementia with high specificity and positive predictive value, but with inferior sensitivity compared to FDG-PET. (orig.)

Exploring requirements and alternative pet robots for robot assisted therapy with older adults with dementia

NARCIS (Netherlands)

P Martinez-Martim; J. Albo-Canals; S. Anisuzzaman; Marcel Heerink; M. Valenti-Soler; J. Zondag; C. Smits

2013-01-01

Robot assisted therapy has been applied in care for older adults who suffer from dementia for over ten years. Strong effects like improved interac-tion and signs of a higher sense of wellbeing have been reported. Still it is un-clear which features are needed and which robotic pets would are

Regional cerebral glucose metabolism in frontotemporal dementia: a study with FDG PET

Energy Technology Data Exchange (ETDEWEB)

Cho, S. S.; Jeong, J.; Kang, S. J.; Na, D. L.; Choe, Y. S.; Lee, K. H.; Choi, Y.; Kim, B. T.; Kim, S. E. [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2002-07-01

Frontotemporal dementia (FTD) is a common cause of presenile dementia. We investigated the regional cerebral glucose metabolic impairments in patients with FTD using FDG PET. We analysed the regional metabolic patterns on FDG PET images obtained from 30 patients with FTD and age- and sex-matched 15 patients with Alzheimers disease (AD) and 11 healthy subjects using SPM99. We also compared the inter-hemispheric metabolic asymmetry among the three groups by counting the total metabolic activity of each hemisphere and computing asymmetry index (AL) between hemispheres. The hypometabolic brain regions in FTD patients compared with healthy controls were as follows: superior middle and medial frontal lobules, superior and middle temporal lobules, anterior and posterior cingulate gyri, uncus, insula, lateral globus pallidus and thalamus. The regions with decreased metabolism in FTD patients compared with AD patients were as follows: superior, inferior and medial frontal lobules, anterior cingulate gyrus, and caudate nucleus. Twenty-five (83%) out of the 30 FTD patients had AI values that was beyond the 95% confidence interval of the AI values obtained from healthy controls; 10 patients had hypometabolism more severe on the right and 15 patients had the opposite pattern. In comparison, 10 (67%) out of the 15 AD patients had asymmetric metabolism. Our SPM analysis of FDG PET revealed additional areas of decreased metabolism in FTD patients compared with prior studies using the ROI method, involving frontal, temporal, cingulate gyrus, corpus callosum, uncus, insula, and some subcortical areas. The inter-hemispheric metabolic asymmetry was common in FTD patients, which can be another metabolic feature that helps differentiate FTD from AD.

Regional cerebral glucose metabolism in frontotemporal dementia: a study with FDG PET

International Nuclear Information System (INIS)

Cho, S. S.; Jeong, J.; Kang, S. J.; Na, D. L.; Choe, Y. S.; Lee, K. H.; Choi, Y.; Kim, B. T.; Kim, S. E.

2002-01-01

Frontotemporal dementia (FTD) is a common cause of presenile dementia. We investigated the regional cerebral glucose metabolic impairments in patients with FTD using FDG PET. We analysed the regional metabolic patterns on FDG PET images obtained from 30 patients with FTD and age- and sex-matched 15 patients with Alzheimers disease (AD) and 11 healthy subjects using SPM99. We also compared the inter-hemispheric metabolic asymmetry among the three groups by counting the total metabolic activity of each hemisphere and computing asymmetry index (AL) between hemispheres. The hypometabolic brain regions in FTD patients compared with healthy controls were as follows: superior middle and medial frontal lobules, superior and middle temporal lobules, anterior and posterior cingulate gyri, uncus, insula, lateral globus pallidus and thalamus. The regions with decreased metabolism in FTD patients compared with AD patients were as follows: superior, inferior and medial frontal lobules, anterior cingulate gyrus, and caudate nucleus. Twenty-five (83%) out of the 30 FTD patients had AI values that was beyond the 95% confidence interval of the AI values obtained from healthy controls; 10 patients had hypometabolism more severe on the right and 15 patients had the opposite pattern. In comparison, 10 (67%) out of the 15 AD patients had asymmetric metabolism. Our SPM analysis of FDG PET revealed additional areas of decreased metabolism in FTD patients compared with prior studies using the ROI method, involving frontal, temporal, cingulate gyrus, corpus callosum, uncus, insula, and some subcortical areas. The inter-hemispheric metabolic asymmetry was common in FTD patients, which can be another metabolic feature that helps differentiate FTD from AD

Dual Tracer PET Imaging with FDG and FLT Differentiates Tuberculous Lymphadenopathy from Metastases in a Case of Carcinoma Cervix

Energy Technology Data Exchange (ETDEWEB)

Joshi, Prathamesh; Lele, Vikram; Aland, Parag; Gemawat, Shilpa [Jaslok Hospital and Research Centre, Woril (India)

2013-09-15

A forty-year-old woman with a known case of carcinoma cervix underwent 18-fluorodeoxyglucose positron emission tomography.computed tomography (18-FDG PET/CT) for evaluation of abdominal lymphadenopathy. Her treatment history included radical hysterectomy and radiotherapy 6 months ago. She complained of weight loss of 7 kg over last 5 months. The maximum intensity projection (MIP) image (Fig. 1a, arrows) revealed multiple areas of intense FDG uptake, which on CT and fused PET/CT images were localized to multiple lymph nodes in bilateral cervical region, right axilla, mediastinum and abdomen. The SUVmax of right axillary lymph nodes (most FDG avid of all lymph node groups) was 15.3. There was no evidence of metabolically active disease or CT demonstrable abnormality in rest of the body. Presence of metabolically active disease in extensive supradiaphramatic lymphadenopathy was unusual for a case of carcinoma cervix. This finding, along with history of significant weight loss and absence of extranodal disease, was suspicious for unrelated pathology like lymphoproliferative disorder or granulomatous disease. Mixed malignant and benign lymphadenopathy was also considered a possibility. To solve the conundrum, 18-fluoro-L-thymidine (FLT) PET/CT was performed on the next day. This scan was performed to assess the proliferation rate in various above-mentioned lymph nodes, and to plan the optimum site of biopsy. The FLT PET scan (Fig. 1b) showed physiological distribution of the tracer in bone marrow, liver, gall bladder and urinary bladder. There was minimal FLT uptake in the enlarged, FDG avid lymph nodes (Fig. 1c and d). SUVmax of FLT uptake in right axillary lymph nodes was 1.4 (SUVmax of FDG uptake = 15.8). The SUVmax of FLT uptake in cervical, mediastinal and abdominal lymph nodes were 1.3, 1.4 and 1.0 respectively. (SUVmax of FDG uptake 12.1, 12.7 and 11.9, respectively). Considering avidity for FDG and non-avidity of proliferation marker tracer (FLT), possibility of

PET and SPET tracers for mapping the cardiac nervous system

International Nuclear Information System (INIS)

Langer, Oliver; Halldin, Christer

2002-01-01

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-[ 18 F]fluorodopamine, (-)-6-[ 18 F]fluoronorepinephrine and (-)-[ 11 C]epinephrine, and radiolabelled catecholamine analogues, such as [ 123 I]meta-iodobenzylguanidine, [ 11 C]meta-hydroxyephedrine, [ 18 F]fluorometaraminol, [ 11 C]phenylephrine and meta-[ 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 (-)-[ 18 F]fluoroethoxybenzovesamicol display a high degree of non-specific binding in myocardium which restricts their utility for cardiac neuronal imaging. (orig.)

Impact of advanced MRI techniques for the diagnosis of dementia: comparison with PET

DEFF Research Database (Denmark)

Steffensen, Elena; Prakash, Vineet; Vestergård, Karsten

Introduction: The use of high magnetic fields in combination with fast algorithms for computer-based postprocessing has moved advanced MRI techniques into clinical practice. MRI provides in analogy with PET physiological information in addition to more traditional morphological images. Evaluation...... with suspected Alzheimer's disease (AD); 4 with suspected frontotemporal dementia (FTD), and 2 were found normal. Mean FA and ADC values in cingulum and in CC for the patient group compared with controls are presented in Table 1. ADC values in CC were higher comparing with controls and higher for patients...... with suspected FTD than for patients with suspected AD. Conclusion: CBF measurements and characteristics obtained by advanced MRI techniques have a potential to facilitate early diagnosis and understanding of dementia....

Amyloid Imaging in Aging and Dementia: Testing the Amyloid Hypothesis In Vivo

Directory of Open Access Journals (Sweden)

G. D. Rabinovici

2009-01-01

Full Text Available Amyloid imaging represents a major advance in neuroscience, enabling the detection and quantification of pathologic protein aggregations in the brain. In this review we survey current amyloid imaging techniques, focusing on positron emission tomography (PET with ^{11}carbon-labelled Pittsburgh Compound-B (11C-PIB, the most extensively studied and best validated tracer. PIB binds specifically to fibrillar beta-amyloid (Aβ deposits, and is a sensitive marker for Aβ pathology in cognitively normal older individuals and patients with mild cognitive impairment (MCI and Alzheimer’s disease (AD. PIB-PET provides us with a powerful tool to examine in vivo the relationship between amyloid deposition, clinical symptoms, and structural and functional brain changes in the continuum between normal aging and AD. Amyloid imaging studies support a model in which amyloid deposition is an early event on the path to dementia, beginning insidiously in cognitively normal individuals, and accompanied by subtle cognitive decline and functional and structural brain changes suggestive of incipient AD. As patients progress to dementia, clinical decline and neurodegeneration accelerate and proceed independently of amyloid accumulation. In the future, amyloid imaging is likely to supplement clinical evaluation in selecting patients for anti-amyloid therapies, while MRI and FDG-PET may be more appropriate markers of clinical progression.

Development and automation of a novel NET-PET tracer: [11C]Me@APPI.

Science.gov (United States)

Mark, Christina; Bornatowicz, Birgit; Mitterhauser, Markus; Hendl, Matthias; Nics, Lukas; Haeusler, Daniela; Lanzenberger, Rupert; Berger, Michael L; Spreitzer, Helmut; Wadsak, Wolfgang

2013-02-01

The norepinephrine transporter (NET) is an important target for research in neurology and psychology and is involved in the pathophysiology of many neurodegenerative diseases such as Alzheimer's disease and attention deficient hyperactivity disorder. For visualization of NET abundance and deregulation, a novel PET tracer--[(11)C]Me@APPI--has been developed. For precursor synthesis, a 4-step synthesis starting from N-phenyl-o-phenylenediamine was set up. Radiosynthesis was established and optimized using standard methods and subsequently automated in a GE TRACERlabFx C Pro synthesizer. Preclinical testing was performed comprising affinity and selectivity testing on human membranes as well as stability and blood-brain-barrier-penetration using in-vitro models. Precursor molecule (APPI:0) and reference compound (Me@APPI) were synthesized with 26.5% and 21.4% overall yield, respectively. So far, 1.25±0.72 GBq [(11)C]Me@APPI with 54.35±7.80 GBq/μmol specific activity were produced (n=11). Affinity of reference compounds was determined as 8.08±1.75 nM for Me@APPI and 19.31±2.91 nM for APPI:0, respectively (n≥9). IAM-chromatography experiments (n=3) revealed a P(m) value of 1.51±0.34 for Me@APPI. Stability testing using human liver microsomes revealed that 99.5% of the tracer was found to be still intact after 60 minutes (n=4). Present data indicate that [(11)C]Me@APPI has promising properties to become a clinically useful NET-PET-tracer. Further in-vitro and in-vivo evaluations are currently under way. Copyright © 2013 Elsevier Inc. All rights reserved.

Development and automation of a novel NET-PET tracer: [11C]Me@APPI

International Nuclear Information System (INIS)

Mark, Christina; Bornatowicz, Birgit; Mitterhauser, Markus; Hendl, Matthias; Nics, Lukas; Haeusler, Daniela; Lanzenberger, Rupert; Berger, Michael L.; Spreitzer, Helmut; Wadsak, Wolfgang

2013-01-01

Introduction: The norepinephrine transporter (NET) is an important target for research in neurology and psychology and is involved in the pathophysiology of many neurodegenerative diseases such as Alzheimer's disease and attention deficient hyperactivity disorder. For visualization of NET abundance and deregulation, a novel PET tracer – [ 11 C]Me@APPI – has been developed. Methods: For precursor synthesis, a 4-step synthesis starting from N-phenyl-o-phenylenediamine was set up. Radiosynthesis was established and optimized using standard methods and subsequently automated in a GE TRACERlabFx C Pro synthesizer. Preclinical testing was performed comprising affinity and selectivity testing on human membranes as well as stability and blood–brain-barrier-penetration using in-vitro models. Results: Precursor molecule (APPI:0) and reference compound (Me@APPI) were synthesized with 26.5% and 21.4% overall yield, respectively. So far, 1.25 ± 0.72 GBq [ 11 C]Me@APPI with 54.35 ± 7.80 GBq/μmol specific activity were produced (n = 11). Affinity of reference compounds was determined as 8.08 ± 1.75 nM for Me@APPI and 19.31 ± 2.91 nM for APPI:0, respectively (n ≥ 9). IAM-chromatography experiments (n = 3) revealed a P m value of 1.51 ± 0.34 for Me@APPI. Stability testing using human liver microsomes revealed that 99.5% of the tracer was found to be still intact after 60 minutes (n = 4). Conclusion: Present data indicate that [ 11 C]Me@APPI has promising properties to become a clinically useful NET-PET-tracer. Further in-vitro and in-vivo evaluations are currently under way

Dosimetry of 64Cu-DOTA-AE105, a PET tracer for uPAR imaging

International Nuclear Information System (INIS)

Persson, Morten; El Ali, Henrik H.; Binderup, Tina; Pfeifer, Andreas; Madsen, Jacob; Rasmussen, Palle; Kjaer, Andreas

2014-01-01

64 Cu-DOTA-AE105 is a novel positron emission tomography (PET) tracer specific to the human urokinase-type plasminogen activator receptor (uPAR). In preparation of using this tracer in humans, as a new promising method to distinguish between indolent and aggressive cancers, we have performed PET studies in mice to evaluate the in vivo biodistribution and estimate human dosimetry of 64 Cu-DOTA-AE105. Methods: Five mice received iv tail injection of 64 Cu-DOTA-AE105 and were PET/CT scanned 1, 4.5 and 22 h post injection. Volume-of-interest (VOI) were manually drawn on the following organs: heart, lung, liver, kidney, spleen, intestine, muscle, bone and bladder. The activity concentrations in the mentioned organs [%ID/g] were used for the dosimetry calculation. The %ID/g of each organ at 1, 4.5 and 22 h was scaled to human value based on a difference between organ and body weights. The scaled values were then exported to OLINDA software for computation of the human absorbed doses. The residence times as well as effective dose equivalent for male and female could be obtained for each organ. To validate this approach, of human projection using mouse data, five mice received iv tail injection of another 64 Cu-DOTA peptide-based tracer, 64 Cu-DOTA-TATE, and underwent same procedure as just described. The human dosimetry estimates were then compared with observed human dosimetry estimate recently found in a first-in-man study using 64 Cu-DOTA-TATE. Results: Human estimates of 64 Cu-DOTA-AE105 revealed the heart wall to receive the highest dose (0.0918 mSv/MBq) followed by the liver (0.0815 mSv/MBq), All other organs/tissue were estimated to receive doses in the range of 0.02–0.04 mSv/MBq. The mean effective whole-body dose of 64 Cu-DOTA-AE105 was estimated to be 0.0317 mSv/MBq. Relatively good correlation between human predicted and observed dosimetry estimates for 64 Cu-DOTA-TATE was found. Importantly, the effective whole body dose was predicted with very high

Dosimetry of 64Cu-DOTA-AE105, a PET tracer for uPAR imaging.

Science.gov (United States)

Persson, Morten; El Ali, Henrik H; Binderup, Tina; Pfeifer, Andreas; Madsen, Jacob; Rasmussen, Palle; Kjaer, Andreas

2014-03-01

(64)Cu-DOTA-AE105 is a novel positron emission tomography (PET) tracer specific to the human urokinase-type plasminogen activator receptor (uPAR). In preparation of using this tracer in humans, as a new promising method to distinguish between indolent and aggressive cancers, we have performed PET studies in mice to evaluate the in vivo biodistribution and estimate human dosimetry of (64)Cu-DOTA-AE105. Five mice received iv tail injection of (64)Cu-DOTA-AE105 and were PET/CT scanned 1, 4.5 and 22 h post injection. Volume-of-interest (VOI) were manually drawn on the following organs: heart, lung, liver, kidney, spleen, intestine, muscle, bone and bladder. The activity concentrations in the mentioned organs [%ID/g] were used for the dosimetry calculation. The %ID/g of each organ at 1, 4.5 and 22 h was scaled to human value based on a difference between organ and body weights. The scaled values were then exported to OLINDA software for computation of the human absorbed doses. The residence times as well as effective dose equivalent for male and female could be obtained for each organ. To validate this approach, of human projection using mouse data, five mice received iv tail injection of another (64)Cu-DOTA peptide-based tracer, (64)Cu-DOTA-TATE, and underwent same procedure as just described. The human dosimetry estimates were then compared with observed human dosimetry estimate recently found in a first-in-man study using (64)Cu-DOTA-TATE. Human estimates of (64)Cu-DOTA-AE105 revealed the heart wall to receive the highest dose (0.0918 mSv/MBq) followed by the liver (0.0815 mSv/MBq), All other organs/tissue were estimated to receive doses in the range of 0.02-0.04 mSv/MBq. The mean effective whole-body dose of (64)Cu-DOTA-AE105 was estimated to be 0.0317 mSv/MBq. Relatively good correlation between human predicted and observed dosimetry estimates for (64)Cu-DOTA-TATE was found. Importantly, the effective whole body dose was predicted with very high precision

Evaluation of [{sup 11}C]rofecoxib as PET tracer for cyclooxygenase 2 overexpression in rat models of inflammation

Energy Technology Data Exchange (ETDEWEB)

Vries, Erik F.J. de [Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen (Netherlands)], E-mail: e.f.j.de.vries@ngmb.umcg.nl; Doorduin, Janine; Dierckx, Rudi A.; Waarde, Aren van [Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen (Netherlands)

2008-01-15

Background: Overexpression of cyclooxygenase type 2 (COX-2) is triggered by inflammatory stimuli, but it also plays a prominent role in the initiation and progression of various diseases. This study aims to investigate [{sup 11}C]rofecoxib as a positron emission tomography (PET) tracer for COX-2 expression. Methods: [{sup 11}C]Rofecoxib was prepared by methylation of its sulphinate precursor. Regional brain distribution and specific binding of [{sup 11}C]rofecoxib in healthy rats was studied by ex vivo biodistribution and autoradiography. Regional brain distribution and PET imaging studies were also performed on rats with severe encephalitis, caused by nasal infection with herpes simplex virus (HSV). Finally, ex vivo biodistribution and blocking studies were carried in rats with a sterile inflammation, induced by intramuscular turpentine injection. Results: [{sup 11}C]rofecoxib brain uptake in control animals corresponded with the known distribution of COX-2. Pretreatment with NS398 significantly reduced tracer uptake in the cingulate/frontopolar cortex, whereas the reduction in hippocampus approached significance. Ex vivo autoradiography also revealed preferential tracer uptake in hippocampus and cortical areas that could be blocked by NS398. In HSV-infected animals, [{sup 11}C]rofecoxib uptake was moderately increased in all brain regions, but it could not be blocked with indomethacin. Yet, some PET images revealed increased tracer uptake in brain areas with microglia activation. In turpentine-injected animals, [{sup 11}C]rofecoxib uptake in inflamed muscle was not higher than in control muscle and could not be blocked with NS398. Indomethacin caused a slight reduction in muscle uptake. Conclusions: Despite the apparent correlation between [{sup 11}C]rofecoxib uptake and COX-2 distribution in healthy rats, [{sup 11}C]rofecoxib could not unambiguously detect COX-2 overexpression in two rat models of inflammation.

Non-FDG PET imaging of brain tumors

Institute of Scientific and Technical Information of China (English)

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

2007-01-01

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

Current Role for Biomarkers in Clinical Diagnosis of Alzheimer Disease and Frontotemporal Dementia.

Science.gov (United States)

Sheikh-Bahaei, Nasim; Sajjadi, Seyed Ahmad; Pierce, Aimee L

2017-11-14

Purpose of review Alzheimer's disease (AD) and frontotemporal dementia can often be diagnosed accurately with careful clinical history, cognitive testing, neurological examination, and structural brain MRI. However, there are certain circumstances wherein detection of specific biomarkers of neurodegeneration or underlying AD pathology will impact the clinical diagnosis or treatment plan. We will review the currently available biomarkers for AD and frontotemporal dementia (FTD) and discuss their clinical importance. Recent findings With the advent of 18 F-labeled tracers that bind amyloid plaques, amyloid PET is now clinically available for the detection of amyloid pathology and to aid in a biomarker-supported diagnosis of AD or mild cognitive impairment (MCI) due to AD. It is not yet possible to test for the specific FTD pathologies (tau or TDP-43); however, a diagnosis of FTD may be "imaging supported" based upon specific MRI or FDG-PET findings. Cerebrospinal fluid measures of amyloid-beta, total-tau, and phospho-tau are clinically available and allow detection of both of the cardinal pathologies of AD: amyloid and tau pathology. Summary It is appropriate to pursue biomarker testing in cases of MCI and dementia when there remains diagnostic uncertainty and the result will impact diagnosis or treatment. Practically speaking, due to the rising prevalence of amyloid positivity with advancing age, measurement of biomarkers in cases of MCI and dementia is most helpful in early-onset patients, patients with atypical clinical presentations, or when considering referral for AD clinical trials.

Reversal of brain metabolic abnormalities following treatment of AIDS dementia complex with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine): a PET-FDG study

International Nuclear Information System (INIS)

Brunetti, A.; Berg, G.; Di Chiro, G.

1989-01-01

Brain glucose metabolism was evaluated in four patients with acquired immunodeficiency syndrome (AIDS) dementia complex using [ 18 F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) scans at the beginning of therapy with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine), and later in the course of therapy. In two patients, baseline, large focal cortical abnormalities of glucose utilization were reversed during the course of therapy. In the other two patients, the initial PET study did not reveal pronounced focal alterations, while the post-treatment scans showed markedly increased cortical glucose metabolism. The improved cortical glucose utilization was accompanied in all patients by immunologic and neurologic improvement. PET-FDG studies can detect cortical metabolic abnormalities associated with AIDS dementia complex, and may be used to monitor the metabolic improvement in response to AZT treatment

Creutzfeldt-Jakob Disease Mimicking Alzheimer Disease and Dementia With Lewy Bodies-Findings of FDG PET With 3-Dimensional Stereotactic Surface Projection.

Science.gov (United States)

Miyazawa, Nobuhiko

2017-05-01

A 78-year-old man received a diagnosis of sporadic Creutzfeldt-Jakob disease based on symptoms and findings of MRI, FDG PET, and cerebrospinal fluid markers. PET with 3-dimensional stereotactic surface projection (3D-SSP) showed that the distribution of hypometabolism mimicked that of Alzheimer disease. A 68-year-old woman was treated under a diagnosis of convulsion. Findings of MRI, PET, familial history, and cerebrospinal fluid markers revealed familial Creutzfeldt-Jakob disease. FDG PET with 3D-SSP disclosed that the hypometabolic pattern mimicked that of dementia with Lewy bodies. FDG PET with 3D-SSP can demonstrate similar patterns in various neurodegenerative disorders.

Tau-PET Binding Distinguishes Patients With Early-stage Posterior Cortical Atrophy From Amnestic Alzheimer Disease Dementia.

Science.gov (United States)

Day, Gregory S; Gordon, Brian A; Jackson, Kelley; Christensen, Jon J; Rosana Ponisio, Maria; Su, Yi; Ances, Beau M; Benzinger, Tammie L S; Morris, John C

2017-01-01

Flortaucipir (tau) positron emission tomography (PET) binding distinguishes individuals with clinically well-established posterior cortical atrophy (PCA) due to Alzheimer disease (AD) from cognitively normal (CN) controls. However, it is not known whether tau-PET binding patterns differentiate individuals with PCA from those with amnestic AD, particularly early in the symptomatic stages of disease. Flortaucipir and florbetapir (β-amyloid) PET imaging were performed in individuals with early-stage PCA (N=5), amnestic AD dementia (N=22), and CN controls (N=47). Average tau and β-amyloid deposition were quantified using standard uptake value ratios and compared at a voxelwise level, controlling for age. PCA patients [median age-at-onset, 59 (51 to 61) years] were younger at symptom onset than similarly staged individuals with amnestic AD [75 (60 to 85) years] or CN controls [73 (61 to 90) years; P=0.002]. Flortaucipir uptake was higher in individuals with early-stage symptomatic PCA versus those with early-stage amnestic AD or CN controls, and greatest in posterior regions. Regional elevations in florbetapir were observed in areas of greatest tau deposition in PCA patients. Flortaucipir uptake distinguished individuals with PCA and amnestic AD dementia early in the symptomatic course. The posterior brain regions appear to be uniquely vulnerable to tau deposition in PCA, aligning with clinical deficits that define this disease subtype.

Tau PET binding distinguishes patients with early-stage posterior cortical atrophy from amnestic Alzheimer disease dementia

Science.gov (United States)

Day, Gregory S.; Gordon, Brian A.; Jackson, Kelley; Christensen, Jon J.; Ponisio, Maria Rosana; Su, Yi; Ances, Beau M; Benzinger, Tammie L.S.; Morris, John C.

2017-01-01

Background Flortaucipir (tau) PET binding distinguishes individuals with clinically well-established posterior cortical atrophy (PCA) due to Alzheimer disease (AD) from cognitively normal (CN) controls. However, it is not known whether tau PET binding patterns differentiate individuals with PCA from those with amnestic AD, particularly early in the symptomatic stages of disease. Methods Flortaucipir and florbetapir (β-amyloid) PET-imaging were performed in individuals with early-stage PCA (N=5), amnestic AD dementia (N=22), and CN controls (N=47). Average tau and β-amyloid deposition were quantified using standard uptake value ratios and compared at a voxel-wise level, controlling for age. Results PCA patients (median age-at-onset, 59 [51–61] years) were younger at symptom-onset than similarly-staged individuals with amnestic AD (75 [60–85] years) or CN controls (73 [61–90] years; p=0.002). Flortaucipir uptake was higher in individuals with early-stage symptomatic PCA versus those with early-stage amnestic AD or CN controls, and greatest in posterior regions. Regional elevations in florbetapir were observed in areas of greatest tau deposition in PCA patients. Conclusions and Relevance Flortaucipir uptake distinguished individuals with PCA and amnestic AD dementia early in the symptomatic course. The posterior brain regions appear to be uniquely vulnerable to tau deposition in PCA, aligning with clinical deficits that define this disease subtype. PMID:28394771

Clinical utility of FDG PET in Parkinson's disease and atypical parkinsonism associated with dementia.

Science.gov (United States)

Walker, Zuzana; Gandolfo, Federica; Orini, Stefania; Garibotto, Valentina; Agosta, Federica; Arbizu, Javier; Bouwman, Femke; Drzezga, Alexander; Nestor, Peter; Boccardi, Marina; Altomare, Daniele; Festari, Cristina; Nobili, Flavio

2018-05-19

There are no comprehensive guidelines for the use of FDG PET in the following three clinical scenarios: (1) diagnostic work-up of patients with idiopathic Parkinson's disease (PD) at risk of future cognitive decline, (2) discriminating idiopathic PD from progressive supranuclear palsy, and (3) identifying the underlying neuropathology in corticobasal syndrome. We therefore performed three literature searches and evaluated the selected studies for quality of design, risk of bias, inconsistency, imprecision, indirectness and effect size. Critical outcomes were the sensitivity, specificity, accuracy, positive/negative predictive value, area under the receiving operating characteristic curve, and positive/negative likelihood ratio of FDG PET in detecting the target condition. Using the Delphi method, a panel of seven experts voted for or against the use of FDG PET based on published evidence and expert opinion. Of 91 studies selected from the three literature searches, only four included an adequate quantitative assessment of the performance of FDG PET. The majority of studies lacked robust methodology due to lack of critical outcomes, inadequate gold standard and no head-to-head comparison with an appropriate reference standard. The panel recommended the use of FDG PET for all three clinical scenarios based on nonquantitative evidence of clinical utility. Despite widespread use of FDG PET in clinical practice and extensive research, there is still very limited good quality evidence for the use of FDG PET. However, in the opinion of the majority of the panellists, FDG PET is a clinically useful imaging biomarker for idiopathic PD and atypical parkinsonism associated with dementia.

A Cochrane review on brain [18F]FDG PET in dementia: limitations and future perspectives

International Nuclear Information System (INIS)

Morbelli, Silvia; Garibotto, Valentina; Giessen, Elsmarieke van de; Arbizu, Javier; Chetelat, Gael; Drezgza, Alexander; Hesse, Swen; Lammertsma, Adriaan A.; Law, Ian; Pappata', Sabina; Payoux, Pierre; Pagani, Marco

2015-01-01

Based on a large body of evidence on its diagnostic sensitivity for the identification of AD, in 2004 [18F]FDG PET imaging was approved by the Centers for Medicare and Medicaid Services (CMS, USA) as a routine examination tool for early and differential diagnosis of AD. Since then, large amounts of additional [18F]FDG PET data have become available showing that the addition of [18F]FDG PET to clinical examinations increases diagnostic accuracy in identifying AD patients even in the predementia stage. Of course, new opportunities and new challenges are coming up, which require the definition of the specific role of [18F]FDG PET in the era of AD biomarkers (i.e. relationship with other biomarkers and role as a marker of progression in AD [46, 48]). Meanwhile, in daily clinical practice, nuclear medicine experts should continue to perform high-quality [18F]FDG PET scans, constantly improving the standard through continuous education and the use of appropriate tools, knowing that it is one of the most informative biomarkers currently available for the prediction of dementia at the MCI stage.

[(11)C]PIB-, [(18)F]FDG-PET and MRI imaging in patients with Parkinson's disease with and without dementia

DEFF Research Database (Denmark)

Jokinen, Pekka; Scheinin, Noora; Aalto, Sargo

2010-01-01

and controls, and hippocampal atrophy was associated with impaired memory. This cross-sectional data suggests that development of dementia in PD is associated with extensive spread of hypometabolism beyond the occipital cortex, and with hippocampal and frontal atrophy but not beta-amyloid deposition consistent...... impairment and dementia in PD. We performed a neuropsychological evaluation, structural brain MRI, [(18)F]FDG PET and [(11)C]PIB PET in 19 PD patients [eight non-demented (PD), eleven demented (PDD)] and 24 healthy elderly volunteers. [(11)C]PIB region-to-cerebellum ratios did not differ significantly...... between the groups in any brain region (p > 0.05). PDD patients showed impaired glucose metabolism in cortical brain regions and this reduction was associated with the degree of cognitive impairment. PDD patients had more atrophy both in the hippocampus and the frontal cortex compared with PD patients...

Small Molecule PET-Radiopharmaceuticals

NARCIS (Netherlands)

Elsinga, Philip H.; Dierckx, Rudi A. J. O.

This review describes several aspects required for the development of small molecule PET-tracers. Design and selection criteria are important to consider before starting to develop novel PET-tracers. Principles and latest trends in C-11 and F-18-radiochemistry are summarized. In addition an update

Visual Versus Fully Automated Analyses of 18F-FDG and Amyloid PET for Prediction of Dementia Due to Alzheimer Disease in Mild Cognitive Impairment.

Science.gov (United States)

Grimmer, Timo; Wutz, Carolin; Alexopoulos, Panagiotis; Drzezga, Alexander; Förster, Stefan; Förstl, Hans; Goldhardt, Oliver; Ortner, Marion; Sorg, Christian; Kurz, Alexander

2016-02-01

Biomarkers of Alzheimer disease (AD) can be imaged in vivo and can be used for diagnostic and prognostic purposes in people with cognitive decline and dementia. Indicators of amyloid deposition such as (11)C-Pittsburgh compound B ((11)C-PiB) PET are primarily used to identify or rule out brain diseases that are associated with amyloid pathology but have also been deployed to forecast the clinical course. Indicators of neuronal metabolism including (18)F-FDG PET demonstrate the localization and severity of neuronal dysfunction and are valuable for differential diagnosis and for predicting the progression from mild cognitive impairment (MCI) to dementia. It is a matter of debate whether to analyze these images visually or using automated techniques. Therefore, we compared the usefulness of both imaging methods and both analyzing strategies to predict dementia due to AD. In MCI participants, a baseline examination, including clinical and imaging assessments, and a clinical follow-up examination after a planned interval of 24 mo were performed. Of 28 MCI patients, 9 developed dementia due to AD, 2 developed frontotemporal dementia, and 1 developed moderate dementia of unknown etiology. The positive and negative predictive values and the accuracy of visual and fully automated analyses of (11)C-PiB for the prediction of progression to dementia due to AD were 0.50, 1.00, and 0.68, respectively, for the visual and 0.53, 1.00, and 0.71, respectively, for the automated analyses. Positive predictive value, negative predictive value, and accuracy of fully automated analyses of (18)F-FDG PET were 0.37, 0.78, and 0.50, respectively. Results of visual analyses were highly variable between raters but were superior to automated analyses. Both (18)F-FDG and (11)C-PiB imaging appear to be of limited use for predicting the progression from MCI to dementia due to AD in short-term follow-up, irrespective of the strategy of analysis. On the other hand, amyloid PET is extremely useful to

Analysis of metabolism of 6FDG: a PET glucose transport tracer

Energy Technology Data Exchange (ETDEWEB)

Muzic, Raymond F., E-mail: raymond.muzic@case.edu [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Chandramouli, Visvanathan [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Huang, Hsuan-Ming [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Wu Chunying; Wang Yanming [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Ismail-Beigi, Faramarz [Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

2011-07-15

Introduction: We are developing {sup 18}F-labeled 6-fluoro-6-deoxy-D-glucose ([{sup 18}F]6FDG) as a tracer of glucose transport. As part of this process it is important to characterize and quantify putative metabolites. In contrast to the ubiquitous positron emission tomography (PET) tracer {sup 18}F-labeled 2-fluoro-2-deoxy-D-glucose ([{sup 18}F]2FDG) which is phosphorylated and trapped intracellularly, the substitution of fluorine for a hydroxyl group at carbon-6 in [{sup 18}F]6FDG should prevent its phosphorylation. Consequently, [{sup 18}F]6FDG has the potential to trace the transport step of glucose metabolism without the confounding effects of phosphorylation and subsequent steps of metabolism. Herein the focus is to determine whether, and the degree to which, [{sup 18}F]6FDG remains unchanged following intravenous injection. Methods: Biodistribution studies were performed using 6FDG labeled with {sup 18}F or with the longer-lived radionuclides {sup 3}H and {sup 14}C. Tissues were harvested at 1, 6, and 24 h following intravenous administration and radioactivity was extracted from the tissues and analyzed using a combination of ion exchange columns, high-performance liquid chromatography, and chemical reactivity. Results: At the 1 h time-point, the vast majority of radioactivity in the liver, brain, heart, skeletal muscle, and blood was identified as 6FDG. At the 6-h and 24-h time points, there was evidence of a minor amount of radioactive material that appeared to be 6-fluoro-6-deoxy-D-sorbitol and possibly 6-fluoro-6-deoxy-D-gluconic acid. Conclusion: On the time scale typical of PET imaging studies radioactive metabolites of [{sup 18}F]6FDG are negligible.

A Cochrane review on brain [{sup 18}F]FDG PET in dementia: limitations and future perspectives

Energy Technology Data Exchange (ETDEWEB)

Morbelli, Silvia [University of Genoa, Nuclear Medicine Unit, IRCCS San Martino - IST, Department of Health Sciences, Genoa (Italy); Garibotto, Valentina [Geneva University and Geneva University Hospitals, Department of Medical Imaging, Geneva (Switzerland); Giessen, Elsmarieke van de [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, Amsterdam (Netherlands); Arbizu, Javier [University of Navarra, Nuclear Medicine Department, Clinica Universidad de Navarra, Pamplona (Spain); Chetelat, Gael [Inserm, U1077, Caen (France); Universite de Caen Basse-Normandie, UMR-S1077, Caen (France); Ecole Pratique des Hautes Etudes, UMR-S1077, Caen (France); CHU de Caen, U1077, Caen (France); Drezgza, Alexander [Universitaet zu Koeln, Klinik und Poliklinik fuer Nuklearmedizin, Koeln (Germany); Hesse, Swen [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Lammertsma, Adriaan A. [VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Law, Ian [Copenhagen University Hospital, Rigshospitalet, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen (Denmark); Pappata' , Sabina [Institute of Biostructure and Bioimaging, CNR, Naples (Italy); Payoux, Pierre [INSERM UMR 825 Toulouse Univ., Imagerie Cerebrale et Handicaps Neurologiques (France); Pagani, Marco [Institute of Cognitive Sciences and Technologies, CNR, Rome (Italy); Karolinska Hospital, Department of Nuclear Medicine, Stockholm (Sweden); Collaboration: European Association of Nuclear Medicine

2015-09-15

Based on a large body of evidence on its diagnostic sensitivity for the identification of AD, in 2004 [18F]FDG PET imaging was approved by the Centers for Medicare and Medicaid Services (CMS, USA) as a routine examination tool for early and differential diagnosis of AD. Since then, large amounts of additional [18F]FDG PET data have become available showing that the addition of [18F]FDG PET to clinical examinations increases diagnostic accuracy in identifying AD patients even in the predementia stage. Of course, new opportunities and new challenges are coming up, which require the definition of the specific role of [18F]FDG PET in the era of AD biomarkers (i.e. relationship with other biomarkers and role as a marker of progression in AD [46, 48]). Meanwhile, in daily clinical practice, nuclear medicine experts should continue to perform high-quality [18F]FDG PET scans, constantly improving the standard through continuous education and the use of appropriate tools, knowing that it is one of the most informative biomarkers currently available for the prediction of dementia at the MCI stage.

Early Dementia Screening

Directory of Open Access Journals (Sweden)

Peter K. Panegyres

2016-01-01

Full Text Available As the population of the world increases, there will be larger numbers of people with dementia and an emerging need for prompt diagnosis and treatment. Early dementia screening is the process by which a patient who might be in the prodromal phases of a dementing illness is determined as having, or not having, the hallmarks of a neurodegenerative condition. The concepts of mild cognitive impairment, or mild neurocognitive disorder, are useful in analyzing the patient in the prodromal phase of a dementing disease; however, the transformation to dementia may be as low as 10% per annum. The search for early dementia requires a comprehensive clinical evaluation, cognitive assessment, determination of functional status, corroborative history and imaging (including MRI, FDG-PET and maybe amyloid PET, cerebrospinal fluid (CSF examination assaying Aβ1–42, T-τ and P-τ might also be helpful. Primary care physicians are fundamental in the screening process and are vital in initiating specialist investigation and treatment. Early dementia screening is especially important in an age where there is a search for disease modifying therapies, where there is mounting evidence that treatment, if given early, might influence the natural history—hence the need for cost-effective screening measures for early dementia.

Automatic extraction of forward stroke volume using dynamic PET/CT: a dual-tracer and dual-scanner validation in patients with heart valve disease.

Science.gov (United States)

Harms, Hendrik Johannes; Tolbod, Lars Poulsen; Hansson, Nils Henrik Stubkjær; Kero, Tanja; Orndahl, Lovisa Holm; Kim, Won Yong; Bjerner, Tomas; Bouchelouche, Kirsten; Wiggers, Henrik; Frøkiær, Jørgen; Sörensen, Jens

2015-12-01

The aim of this study was to develop and validate an automated method for extracting forward stroke volume (FSV) using indicator dilution theory directly from dynamic positron emission tomography (PET) studies for two different tracers and scanners. 35 subjects underwent a dynamic (11)C-acetate PET scan on a Siemens Biograph TruePoint-64 PET/CT (scanner I). In addition, 10 subjects underwent both dynamic (15)O-water PET and (11)C-acetate PET scans on a GE Discovery-ST PET/CT (scanner II). The left ventricular (LV)-aortic time-activity curve (TAC) was extracted automatically from PET data using cluster analysis. The first-pass peak was isolated by automatic extrapolation of the downslope of the TAC. FSV was calculated as the injected dose divided by the product of heart rate and the area under the curve of the first-pass peak. Gold standard FSV was measured using phase-contrast cardiovascular magnetic resonance (CMR). FSVPET correlated highly with FSVCMR (r = 0.87, slope = 0.90 for scanner I, r = 0.87, slope = 1.65, and r = 0.85, slope = 1.69 for scanner II for (15)O-water and (11)C-acetate, respectively) although a systematic bias was observed for both scanners (p dynamic PET/CT and cluster analysis. Results are almost identical for (11)C-acetate and (15)O-water. A scanner-dependent bias was observed, and a scanner calibration factor is required for multi-scanner studies. Generalization of the method to other tracers and scanners requires further validation.

(18)F-alfatide II and (18)F-FDG dual-tracer dynamic PET for parametric, early prediction of tumor response to therapy.

Science.gov (United States)

Guo, Jinxia; Guo, Ning; Lang, Lixin; Kiesewetter, Dale O; Xie, Qingguo; Li, Quanzheng; Eden, Henry S; Niu, Gang; Chen, Xiaoyuan

2014-01-01

A single dynamic PET acquisition using multiple tracers administered closely in time could provide valuable complementary information about a tumor's status under quasiconstant conditions. This study aimed to investigate the utility of dual-tracer dynamic PET imaging with (18)F-alfatide II ((18)F-AlF-NOTA-E[PEG4-c(RGDfk)]2) and (18)F-FDG for parametric monitoring of tumor responses to therapy. We administered doxorubicin to one group of athymic nude mice with U87MG tumors and paclitaxel protein-bound particles to another group of mice with MDA-MB-435 tumors. To monitor therapeutic responses, we performed dual-tracer dynamic imaging, in sessions that lasted 90 min, starting with injection via the tail vein catheters with (18)F-alfatide II, followed 40 min later by (18)F-FDG. To achieve signal separation of the 2 tracers, we fit a 3-compartment reversible model to the time-activity curve of (18)F-alfatide II for the 40 min before (18)F-FDG injection and then extrapolated to 90 min. The (18)F-FDG tumor time-activity curve was isolated from the 90-min dual-tracer tumor time-activity curve by subtracting the fitted (18)F-alfatide II tumor time-activity curve. With separated tumor time-activity curves, the (18)F-alfatide II binding potential (Bp = k3/k4) and volume of distribution (VD) and (18)F-FDG influx rate ((K1 × k3)/(k2 + k3)) based on the Patlak method were calculated to validate the signal recovery in a comparison with 60-min single-tracer imaging and to monitor therapeutic response. The transport and binding rate parameters K1-k3 of (18)F-alfatide II, calculated from the first 40 min of the dual-tracer dynamic scan, as well as Bp and VD correlated well with the parameters from the 60-min single-tracer scan (R(2) > 0.95). Compared with the results of single-tracer PET imaging, (18)F-FDG tumor uptake and influx were recovered well from dual-tracer imaging. On doxorubicin treatment, whereas no significant changes in static tracer uptake values of (18)F-alfatide II

Novel tracer for radiation treatment planning

International Nuclear Information System (INIS)

Schwarzenboeck, S.; Krause, B.J.; Herrmann, K.; Gaertner, F.; Souvatzoglou, M.; Klaesner, B.

2011-01-01

PET and PET/CT with innovative tracers gain increasing importance in diagnosis and therapy management, and radiation treatment planning in radio-oncology besides the widely established FDG. The introduction of [ 18 F]Fluorothymidine ([ 18 F]FLT) as marker of proliferation, [ 18 F]Fluoromisonidazole ([ 18 F]FMISO) and [ 18 F]Fluoroazomycin-Arabinoside ([ 18 F]FAZA) as tracer of hypoxia, [ 18 F]Fluoroethyltyrosine ([ 18 F]FET) and [ 11 C]Methionine for brain tumour imaging, [ 68 Ga]DOTATOC for somatostatin receptor imaging, [ 18 F]FDOPA for dopamine synthesis and radioactively labeled choline derivatives for imaging phospholipid metabolism have opened novel approaches to tumour imaging. Some of these tracers have already been implemented into radio-oncology: Amino acid PET and PET/CT have the potential to optimise radiation treatment planning of brain tumours through accurate delineation of tumour tissue from normal tissue, necrosis and edema. Hypoxia represents a major therapeutic problem in radiation therapy. Hypoxia imaging is very attractive as it may allow to increase the dose in hypoxic tumours potentially allowing for a better tumour control. Advances in hybrid imaging, i.e. the introduction of MR/PET, may also have an impact in radio-oncology through synergies related to the combination of molecular signals of PET and a high soft tissue contrast of MRI as well as functional MRI capabilities. (orig.)

Neuroimaging and functional assessment in dementia

Energy Technology Data Exchange (ETDEWEB)

Terashi, Akiro; Kitamura, Shin; Ujike, Takashi [Nippon Medical School, Tokyo (Japan)

1990-05-01

Recent progress in diagnostic imaging techniques has greatly contributed to the elucidation of pathophysiology, as well as differential diagnosis in dementia. In particular, X-ray computed tomography (CT) offers the ability to detect morphological changes of the brain, whereby making it possible to differentiate between cerebrovascular and degenerative dementias. Magnetic resonance imaging (MRI) allows three-dimensional visualization of gyrus atrophy, providing the ability to depict subcortical minor infarcts and white matter lesions. The advent of positron emission tomography (PET) and single photon emission computed tomography (SPECT) has led to a dramatic progression in the search for pathophysiology of dementia. The purpose of this paper is to outline the recent findings of diagnostic imaging modalities, such as X-ray CT, MRI, PET and SPECT, focusing on those in commonly observed cerebrovascular dementia and in degenerative dementias that are projected to increase. Degenerative dementias cover Alzheimer's disease, Pick's disease, Huntington's disease, progressive supranuclear palsy, Parkinson's disease, and normal pressure hydrocephalus. (N.K.) 90 refs.

64Cu-NODAGA-c(RGDyK) Is a Promising New Angiogenesis PET Tracer: Correlation between Tumor Uptake and Integrin αvβ3 Expression in Human Neuroendocrine Tumor Xenografts

DEFF Research Database (Denmark)

Oxbøl, Jytte; Schjøth-Eskesen, Christina; El Ali, Henrik H.

2012-01-01

727) were administered (64)Cu-NODAGA-c(RGDyK) i.v. for study of biodistribution as well as for dynamic PET. Gene expression of angiogenesis markers integrin α(V), integrin β(3), and VEGF-A were analyzed using QPCR and correlated to the tracer uptake in the tumors (%ID/g). From biodistribution data......Purpose. The purpose of this paper is to evaluate a new PET tracer (64)Cu-NODAGA-c(RGDyK) for imaging of tumor angiogenesis using gene expression of angiogenesis markers as reference and to estimate radiation dosimetry for humans. Procedures. Nude mice with human neuroendocrine tumor xenografts (H...... was estimated to be 0.038 and 0.029 mSv/MBq for females and males, respectively, with highest absorbed dose in bladder wall. Conclusion. (64)Cu-NODAGA-c(RGDyK) is a promising new angiogenesis PET tracer with potential for human use....

18F PET with florbetapir for the early diagnosis of Alzheimer's disease dementia and other dementias in people with mild cognitive impairment (MCI).

Science.gov (United States)

Martínez, Gabriel; Vernooij, Robin Wm; Fuentes Padilla, Paulina; Zamora, Javier; Bonfill Cosp, Xavier; Flicker, Leon

2017-11-22

18 F-florbetapir uptake by brain tissue measured by positron emission tomography (PET) is accepted by regulatory agencies like the Food and Drug Administration (FDA) and the European Medicine Agencies (EMA) for assessing amyloid load in people with dementia. Its added value is mainly demonstrated by excluding Alzheimer's pathology in an established dementia diagnosis. However, the National Institute on Aging and Alzheimer's Association (NIA-AA) revised the diagnostic criteria for Alzheimer's disease and confidence in the diagnosis of mild cognitive impairment (MCI) due to Alzheimer's disease may be increased when using amyloid biomarkers tests like 18 F-florbetapir. These tests, added to the MCI core clinical criteria, might increase the diagnostic test accuracy (DTA) of a testing strategy. However, the DTA of 18 F-florbetapir to predict the progression from MCI to Alzheimer's disease dementia (ADD) or other dementias has not yet been systematically evaluated. To determine the DTA of the 18 F-florbetapir PET scan for detecting people with MCI at time of performing the test who will clinically progress to ADD, other forms of dementia (non-ADD), or any form of dementia at follow-up. This review is current to May 2017. We searched MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP), BIOSIS Citation Index (Thomson Reuters Web of Science), Web of Science Core Collection, including the Science Citation Index (Thomson Reuters Web of Science) and the Conference Proceedings Citation Index (Thomson Reuters Web of Science), LILACS (BIREME), CINAHL (EBSCOhost), ClinicalTrials.gov (https://clinicaltrials.gov), and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) (http://www.who.int/ictrp/search/en/). We also searched ALOIS, the Cochrane Dementia & Cognitive Improvement Group's specialised register of dementia studies (http://www.medicine.ox.ac.uk/alois/). We checked the reference lists of any relevant studies and systematic reviews, and

Animal-assisted therapy for dementia: a review of the literature.

Science.gov (United States)

Filan, Susan L; Llewellyn-Jones, Robert H

2006-12-01

Animal-assisted therapy (AAT) is gaining popularity as part of therapy programs in residential aged care facilities. Humans and pet dogs respond to quiet interaction with a lowering of blood pressure and an increase in neurochemicals associated with relaxation and bonding. These effects may be of benefit in ameliorating behavioral and psychological symptoms of dementia (BPSD). Medline, PsychInfo and CINAHL databases (1960-2005) were searched for papers on AAT or pets and dementia. Publications of controlled trials that measured the effect of AAT for dementia were reviewed. Several small studies suggest that the presence of a dog reduces aggression and agitation, as well as promoting social behavior in people with dementia. One study has shown that aquaria in dining rooms of dementia care units stimulate residents to eat more of their meals and to gain weight but is limited by the small number of facilities studied. There is preliminary evidence that robotic pets may provide pleasure and interest to people with dementia. Current literature suggests that AAT may ameliorate BPSD, but the duration of the beneficial effect has not been explored. The relative benefits of "resident" versus "visiting" pet dogs are unclear and are confounded by the positive effect of pet interaction on staff or caregivers. Further research on the potential benefits of AAT is recommended.

PET imaging of angiogenesis after myocardial infarction/reperfusion using a one-step labeled integrin-targeted tracer {sup 18}F-AlF-NOTA-PRGD2

Energy Technology Data Exchange (ETDEWEB)

Gao, Haokao [The Fourth Military Medical University, Department of Cardiology, Xijing Hospital, Xi' an (China); National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Laboratory of Molecular Imaging and Nanomedicine (LOMIN), Bethesda, MD (United States); Lang, Lixin; Guo, Ning; Quan, Qimeng; Hu, Shuo; Kiesewetter, Dale O.; Niu, Gang; Chen, Xiaoyuan [National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Laboratory of Molecular Imaging and Nanomedicine (LOMIN), Bethesda, MD (United States); Cao, Feng [The Fourth Military Medical University, Department of Cardiology, Xijing Hospital, Xi' an (China)

2012-04-15

The {alpha}{sub v}{beta}{sub 3} integrin represents a potential target for noninvasive imaging of angiogenesis. The purpose of this study was to evaluate a novel one-step labeled integrin {alpha}{sub v}{beta}{sub 3}-targeting positron emission tomography (PET) probe, {sup 18}F-AlF-NOTA-PRGD2, for angiogenesis imaging in a myocardial infarction/reperfusion (MI/R) animal model. Male Sprague-Dawley rats underwent 45-min transient left coronary artery occlusion followed by reperfusion. The myocardial infarction was confirmed by ECG, {sup 18}F-fluorodeoxyglucose (FDG) imaging, and cardiac ultrasound. In vivo PET imaging was used to determine myocardial uptake of {sup 18}F-AlF-NOTA-PRGD2 at different time points following reperfusion. The control peptide RAD was labeled with a similar procedure and used to confirm the specificity. Ex vivo autoradiographic analysis and CD31/CD61 double immunofluorescence staining were performed to validate the PET results. Myocardial origin of the {sup 18}F-AlF-NOTA-PRGD2 accumulation was confirmed by {sup 18}F-FDG and autoradiography. PET imaging demonstrated increased focal accumulation of {sup 18}F-AlF-NOTA-PRGD2 in the infarcted area which started at day 3 (0.28 {+-} 0.03%ID/g, p < 0.05) and peaked between 1 and 3 weeks (0.59 {+-} 0.16 and 0.55 {+-} 0.13%ID/g, respectively). The focal accumulation decreased but still kept at a higher level than the sham group after 4 months of reperfusion (0.31 {+-} 0.01%ID/g, p < 0.05). Pretreatment with unlabeled arginine-glycine-aspartic acid (RGD) peptide significantly decreased tracer uptake, indicating integrin specificity of this tracer. At 1 week after MI/R, uptake of the control tracer {sup 18}F-AlF-NOTA-RAD that does not bind to integrin, in the infarcted area, was only 0.21 {+-} 0.01%ID/g. Autoradiographic imaging showed the same trend of uptake in the myocardial infarction area. The time course of focal tracer uptake was consistent with the pattern of vascular density and integrin {beta

Comparison of two new angiogenesis PET tracers 68Ga-NODAGA-E[c(RGDyK)]2 and 64Cu-NODAGA-E[c(RGDyK)]2; in vivo imaging studies in human xenograft tumors

DEFF Research Database (Denmark)

Oxbøl, Jytte; Brandt-Larsen, Malene; Schjøth-Eskesen, Christina

2014-01-01

INTRODUCTION: The aim of this study was to synthesize and perform a side-by-side comparison of two new tumor-angiogenesis PET tracers (68)Ga-NODAGA-E[c(RGDyK)](2) and (64)Cu-NODAGA-E[c(RGDyK)](2) in vivo using human xenograft tumors in mice. Human radiation burden was estimated to evaluate...... potential for future use as clinical PET tracers for imaging of neo-angiogenesis. METHODS: A (68)Ge/(68)Ga generator was used for the synthesis of (68)Ga-NODAGA-E[c(RGDyK)](2). (68)Ga and (64)Cu labeled NODAGA-E[c(RGDyK)](2) tracers were administrated in nude mice bearing either human glioblastoma (U87MG......) or human neuroendocrine (H727) xenograft tumors. PET/CT scans at 3 time points were used for calculating the tracer uptake in tumors (%ID/g), integrin αVβ3 target specificity was shown by blocking with cold NODAGA-E[c(RGDyK)](2), and biodistribution in normal organs were also examined. From biodistribution...

The application of PET and PET-CT in cervical cancer

International Nuclear Information System (INIS)

Huang Jianmin; Pan Liping; Li Dongxue

2007-01-01

Cervical cancer is the common malignancies in woman, 18 F-fluorodeoxyglucose ( 18 F-FDG) PET is a well-established method for detecting, staging, cancer recurrence, therapeutic response and prognosis of cervical cancer. PET-CT can accurately locate the anatomical sites of tracer uptake and improve the diagnostic accuraccy of PET. (authors)

Early-Dynamic Positron Emission Tomography (PET)/Computed Tomography and PET Angiography for Endoleak Detection After Endovascular Aneurysm Repair.

Science.gov (United States)

Drescher, Robert; Gühne, Falk; Freesmeyer, Martin

2017-06-01

To propose a positron emission tomography (PET)/computed tomography (CT) protocol including early-dynamic and late-phase acquisitions to evaluate graft patency and aneurysm diameter, detect endoleaks, and rule out graft or vessel wall inflammation after endovascular aneurysm repair (EVAR) in one examination without intravenous contrast medium. Early-dynamic PET/CT of the endovascular prosthesis is performed for 180 seconds immediately after intravenous injection of F-18-fluorodeoxyglucose. Data are reconstructed in variable time frames (time periods after tracer injection) to visualize the arterial anatomy and are displayed as PET angiography or fused with CT images. Images are evaluated in view of vascular abnormalities, graft configuration, and tracer accumulation in the aneurysm sac. Whole-body PET/CT is performed 90 to 120 minutes after tracer injection. This protocol for early-dynamic PET/CT and PET angiography has the potential to evaluate vascular diseases, including the diagnosis of complications after endovascular procedures.

Imaging Alzheimer's disease pathophysiology with PET

Directory of Open Access Journals (Sweden)

Lucas Porcello Schilling

Full Text Available ABSTRACT Alzheimer's disease (AD has been reconceptualised as a dynamic pathophysiological process characterized by preclinical, mild cognitive impairment (MCI, and dementia stages. Positron emission tomography (PET associated with various molecular imaging agents reveals numerous aspects of dementia pathophysiology, such as brain amyloidosis, tau accumulation, neuroreceptor changes, metabolism abnormalities and neuroinflammation in dementia patients. In the context of a growing shift toward presymptomatic early diagnosis and disease-modifying interventions, PET molecular imaging agents provide an unprecedented means of quantifying the AD pathophysiological process, monitoring disease progression, ascertaining whether therapies engage their respective brain molecular targets, as well as quantifying pharmacological responses. In the present study, we highlight the most important contributions of PET in describing brain molecular abnormalities in AD.

Measurement of cardiovascular function using a novel view-sharing PET reconstruction method and tracer kinetic analysis

Directory of Open Access Journals (Sweden)

Paul R. Territo

2016-10-01

Full Text Available Abstract Recent advancements in PET instrumentation have made the non-invasive assessment of cardiovascular function in small animals a reality. The majority of small animal PET systems use stationary detector gantries, thus affording high temporal resolution imaging of cardiac function. Systems designed to maximize spatial resolution and detection sensitivity employing rotating gantry designs are suboptimal when high temporal resolution imaging is needed. To overcome this limitation, the current work developed a novel view-sharing data analysis scheme suitable for dynamic cardiac PET imaging using 18F-NaF as the tracer and tracer kinetic model analysis. This scheme was tested in a rat model of cardiovascular function where the relationship between direct transonic flow measures of cardiac output were highly correlated (f(x = 1.0216x − 24.233, R = 0.9158, p < 0.001 with the new model. Similarly, derived measures of stroke volume were also highly correlated (f(x = 0.9655x − 0.0428, R = 0.9453, p < 0.001 with the current approach. Administration of xylazine caused a statistically significant increase in stroke volume (0.32 ± 0.07 ml, p = 0.003, n = 4 and a significant decrease in both heart rate (−155 ± 7.1 beats/min, p < 0.001, n = 4 and cardiac output (−75.9 ± 23.0 ml/kg min, p = 0.01, n = 4. These findings suggest that the new sinogram binning and kinetic modeling methods produce reliable cardiac function measures suitable for longitudinal monitoring of cardiovascular function.

Kinetic modeling in PET imaging of hypoxia

Science.gov (United States)

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

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 contains additional valuable information on the temporal changes in tracer distribution. Kinetic modeling can be used to extract relevant pharmacokinetic parameters of tracer behavior in vivo that reflects relevant physiological processes. In this paper, we review the potential contribution of kinetic analysis for PET imaging of hypoxia. PMID:25250200

A longitudinal study of CMRGlu in dementia of Alzheimer type

Energy Technology Data Exchange (ETDEWEB)

Kuwabara, Yasuo; Ichiya, Yuichi; Ichimiya, Atsushi; Sasaki, Masayuki; Akashi, Yuko; Yoshida, Tsuyoshi; Fukumura, Toshimitsu; Masuda, Kouji [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

1994-10-01

We studied the serial changes of CMRGlu in 6 patients with dementia of Alzheimer type. All patients demonstrated moderately severe dementia at the initial PET scan. Serial PET scans were performed at an interval of 12 to 24 months. Five of the 6 patients showed a deterioration of clinical symptoms at the second scan. The global CMRGlu serially decreased in all patients. An asymmetry of CMRGlu in both the frontal and parietal regions was observed at the initial PET scan, while the direction of asymmetry was preserved at the second PET scan. The ratios (frontal/parietal and parietal/striatum) of CMRGlu showed no interval change. Therefore, CMRGlu was considered to decrease progressively throughout the entire brain in patients with moderately severe dementia of Alzheimer type. (author).

A longitudinal study of CMRGlu in dementia of Alzheimer type

International Nuclear Information System (INIS)

Kuwabara, Yasuo; Ichiya, Yuichi; Ichimiya, Atsushi; Sasaki, Masayuki; Akashi, Yuko; Yoshida, Tsuyoshi; Fukumura, Toshimitsu; Masuda, Kouji

1994-01-01

We studied the serial changes of CMRGlu in 6 patients with dementia of Alzheimer type. All patients demonstrated moderately severe dementia at the initial PET scan. Serial PET scans were performed at an interval of 12 to 24 months. Five of the 6 patients showed a deterioration of clinical symptoms at the second scan. The global CMRGlu serially decreased in all patients. An asymmetry of CMRGlu in both the frontal and parietal regions was observed at the initial PET scan, while the direction of asymmetry was preserved at the second PET scan. The ratios (frontal/parietal and parietal/striatum) of CMRGlu showed no interval change. Therefore, CMRGlu was considered to decrease progressively throughout the entire brain in patients with moderately severe dementia of Alzheimer type. (author)

New SPECT tracers: Example of tracers of proteoglycans and melanin

International Nuclear Information System (INIS)

Cachin, F.; Mestas, D.; Kelly, A.; Merlin, C.; Veyre, A.; Maublant, J.; Cachin, F.; Chezal, J.M.; Miot-Noirault, E.; Moins, N.; Auzeloux, P.; Vidal, A.; Bonnet-Duquennoy, M.; Boisgard, S.; D'Incan, M.; Madelmont, J.C.; Maublant, J.; Boisgard, S.; D'Incan, M.; Redini, F.; Filaire, M.

2009-01-01

The majority of research program on new radiopharmaceuticals turn to tracers used for positron emission tomography (PET). Only a few teams work on new non fluorine labeled tracers. However, the coming of SPECT/CT gamma cameras, the arrival of semi-conductors gamma cameras should boost the development of non-PET tracers. We exhibit in this article the experience acquired by our laboratory in the conception and design of two new non fluorine labelled compounds. The 99m Tc-N.T.P. 15-5 (N.T.P. 15-5 for N-[tri-ethyl-ammonium]-3-propyl-[15]ane-N5) which binds to proteoglycans could be used for the diagnosis and staging of osteoarthritis and chondrosarcoma. The iodo benzamides, specific to the melanin, are nowadays compared to 18 F-fluorodeoxyglucose in a phase III clinical trial for the diagnosis and detection of melanoma metastasis. Our last development focus on N-[2-(diethyl-amino)ethyl]-4 and 2-iodo benzamides respectively B.Z.A. and B.Z.A.2 hetero-aromatic analogues usable for melanoma treatment. (authors)

Biocompatible branched copolymer nanoparticles prepared by RAFT polymerization as MRI/PET bimodal tracers

Energy Technology Data Exchange (ETDEWEB)

Yang, Chang-Tong [Lee Kong Chian School of Medicine, Nanyang Technological University (Singapore); Tao, He; Jackson, Alexander W [Institute of Chemical and Engineering Sciences, Agency for Science Technology and Research (Singapore); Chandrasekharan, Prashant [Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Agency for Science Technology and Research (Singapore); Padmanabhan, Parasuraman [Lee Kong Chian School of Medicine, Nanyang Technological University (Singapore); Gulyás, Balázs; Halldin, Christer [Lee Kong Chian School of Medicine, Nanyang Technological University (Singapore); Karolinska Institutet, Department of Clinical Neuroscience, Stockholm (Sweden)

2015-05-18

Stable branched copolymer nanoparticles of varying size (Dh = 20 – 35 nm) have been developed and employed as MRI nano-sized contrast agents. RAFT polymerization has been employed to prepare these novel nanoparticles possessing DO3A macrocycles within their cores and succinimidyl ester benzoate functionalities within their coronas. It has been demonstrated that these nanoparticles can chelate gadolinium and in vitro cytotoxicity studies using HK-2 cells established their negligible toxicity profile. In vivo MRI experiments showed that these nanoparticles have a high relaxivity and a long blood retention time. Xenograft experiments further illustrated the ability of these nanoparticles to perfuse and passively accumulate in tumor cells, presumably through the enhanced EPR effect. The presence of the succinimidyl ester benzoate functionalities within the nanoparticle coronas will permit future surface modification with fluorophores or targeting moieties to generate nanoparticles to study opportunities for bimodal imaging nano-probes or active cell targeting contrast agents. The chelation with PET radioisotopes (68Ga(III) or 64Cu(II)) can afford various PET tracers.

Biocompatible branched copolymer nanoparticles prepared by RAFT polymerization as MRI/PET bimodal tracers

International Nuclear Information System (INIS)

Yang, Chang-Tong; Tao, He; Jackson, Alexander W; Chandrasekharan, Prashant; Padmanabhan, Parasuraman; Gulyás, Balázs; Halldin, Christer

2015-01-01

Stable branched copolymer nanoparticles of varying size (Dh = 20 – 35 nm) have been developed and employed as MRI nano-sized contrast agents. RAFT polymerization has been employed to prepare these novel nanoparticles possessing DO3A macrocycles within their cores and succinimidyl ester benzoate functionalities within their coronas. It has been demonstrated that these nanoparticles can chelate gadolinium and in vitro cytotoxicity studies using HK-2 cells established their negligible toxicity profile. In vivo MRI experiments showed that these nanoparticles have a high relaxivity and a long blood retention time. Xenograft experiments further illustrated the ability of these nanoparticles to perfuse and passively accumulate in tumor cells, presumably through the enhanced EPR effect. The presence of the succinimidyl ester benzoate functionalities within the nanoparticle coronas will permit future surface modification with fluorophores or targeting moieties to generate nanoparticles to study opportunities for bimodal imaging nano-probes or active cell targeting contrast agents. The chelation with PET radioisotopes (68Ga(III) or 64Cu(II)) can afford various PET tracers.

Synthesis of tracers using automated radiochemistry and robotics

International Nuclear Information System (INIS)

Dannals, R.F.

1992-07-01

Synthesis of high specific activity radiotracers labeled with short-lived positron-emitting radionuclides for positron emission tomography (PET) often requires handling large initial quantities of radioactivity. High specific activities are required when preparing tracers for use in PET studies of neuroreceptors. A fully automated approach for tracer synthesis is highly desirable. This proposal involves the development of a system for the Synthesis of Tracers using Automated Radiochemistry and Robotics (STARR) for this purpose. While the long range objective of the proposed research is the development of a totally automated radiochemistry system for the production of major high specific activity 11 C-radiotracers for use in PET, the specific short range objectives are the automation of 11 C-methyl iodide ( 11 CH 3 I) production via an integrated approach using both radiochemistry modular labstations and robotics, and the extension of this automated capability to the production of several radiotracers for PET (initially, 11 C-methionine, 3-N-[ 11 C-methyl]spiperone, and [ 11 C]-carfentanil)

Positron emission tomography with additional γ-ray detectors for multiple-tracer imaging.

Science.gov (United States)

Fukuchi, Tomonori; Okauchi, Takashi; Shigeta, Mika; Yamamoto, Seiichi; Watanabe, Yasuyoshi; Enomoto, Shuichi

2017-06-01

Positron emission tomography (PET) is a useful imaging modality that quantifies the physiological distributions of radiolabeled tracers in vivo in humans and animals. However, this technique is unsuitable for multiple-tracer imaging because the annihilation photons used for PET imaging have a fixed energy regardless of the selection of the radionuclide tracer. This study developed a multi-isotope PET (MI-PET) system and evaluated its imaging performance. Our MI-PET system is composed of a PET system and additional γ-ray detectors. The PET system consists of pixelized gadolinium orthosilicate (GSO) scintillation detectors and has a ring geometry that is 95 mm in diameter with an axial field of view of 37.5 mm. The additional detectors are eight bismuth germanium oxide (BGO) scintillation detectors, each of which is 50 × 50 × 30 mm 3 , arranged into two rings mounted on each side of the PET ring with a 92-mm-inner diameter. This system can distinguish between different tracers using the additional γ-ray detectors to observe prompt γ-rays, which are emitted after positron emission and have an energy intrinsic to each radionuclide. Our system can simultaneously acquire double- (two annihilation photons) and triple- (two annihilation photons and a prompt γ-ray) coincidence events. The system's efficiency for detecting prompt de-excitation γ-rays was measured using a positron-γ emitter, 22 Na. Dual-radionuclide ( 18 F and 22 Na) imaging of a rod phantom and a mouse was performed to demonstrate the performance of the developed system. Our system's basic performance was evaluated by reconstructing two images, one containing both tracers and the other containing just the second tracer, from list-mode data sets that were categorized by the presence or absence of the prompt γ-ray. The maximum detection efficiency for 1275 keV γ-rays emitted from 22 Na was approximately 7% at the scanner's center, and the minimum detection efficiency was 5.1% at the edge of

11C-harmine as a potential PET tracer for ductal pancreas cancer: in vitro studies

International Nuclear Information System (INIS)

Herlin, G.; Persson, B.; Laangstroem, B.; Aspelin, P.; Bergstroem, M.

2003-01-01

Our objective was to find a tracer in diagnosing human pancreatic cancer using positron emission tomography (PET). For this purpose in vitro test of pancreatic tissues with autoradiography was used. Autoradiography was performed with 11 C-harmine (a MAO-A-inhibitor) with and without competitive inhibition. Tissue preparations were obtained from normal human pancreas and pancreatic cancer. The uptake was compared with rat brain or pig brain, tissues with high expression of MAO-A. Nine autoradiography studies on 16 samples from five different human pancreatic cancers gave a significant level of specific binding of 11 C-harmine in 13, and 3 samples did not give a significant level of specific binding of 11 C-harmine. All 16 samples were analysed with autoradiography. Compared with rat brain, the uptake in the human cancers varied between 9 and 43% except for one tissue preparation which had a too low value for measurement. This study shows expression of MAO-A in human pancreatic cancer. This is readily characterised in vitro. The potential use of 11 C-harmine in the diagnosis of pancreatic cancer using PET might be limited, but further PET studies are necessary. (orig.)

Other PET tracers for neuroendocrine tumors

NARCIS (Netherlands)

Koopmans, Klaas Pieter; Glaudemans, Andor W J M

In this article the applicability of (124)I-MIBG and (11)C-5-HTP PET for the detection of abdominal gastro-enteropancreatic neuroendocrine tumors is discussed. (124)I-MIBG is a positron-emitting variant of (123)I-MIBG and therefore suited for PET imaging. Due to the better intrinsic characteristics

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

Directory of Open Access Journals (Sweden)

Sonja Probst

2014-01-01

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

A new integrated dual time-point amyloid PET/MRI data analysis method

International Nuclear Information System (INIS)

Cecchin, Diego; Zucchetta, Pietro; Turco, Paolo; Bui, Franco; Barthel, Henryk; Tiepolt, Solveig; Sabri, Osama; Poggiali, Davide; Cagnin, Annachiara; Gallo, Paolo; Frigo, Anna Chiara

2017-01-01

In the initial evaluation of patients with suspected dementia and Alzheimer's disease, there is no consensus on how to perform semiquantification of amyloid in such a way that it: (1) facilitates visual qualitative interpretation, (2) takes the kinetic behaviour of the tracer into consideration particularly with regard to at least partially correcting for blood flow dependence, (3) analyses the amyloid load based on accurate parcellation of cortical and subcortical areas, (4) includes partial volume effect correction (PVEC), (5) includes MRI-derived topographical indexes, (6) enables application to PET/MRI images and PET/CT images with separately acquired MR images, and (7) allows automation. A method with all of these characteristics was retrospectively tested in 86 subjects who underwent amyloid ( 18 F-florbetaben) PET/MRI in a clinical setting (using images acquired 90-110 min after injection, 53 were classified visually as amyloid-negative and 33 as amyloid-positive). Early images after tracer administration were acquired between 0 and 10 min after injection, and later images were acquired between 90 and 110 min after injection. PVEC of the PET data was carried out using the geometric transfer matrix method. Parametric images and some regional output parameters, including two innovative ''dual time-point'' indexes, were obtained. Subjects classified visually as amyloid-positive showed a sparse tracer uptake in the primary sensory, motor and visual areas in accordance with the isocortical stage of the topographic distribution of the amyloid plaque (Braak stages V/VI). In patients classified visually as amyloid-negative, the method revealed detectable levels of tracer uptake in the basal portions of the frontal and temporal lobes, areas that are known to be sites of early deposition of amyloid plaques that probably represented early accumulation (Braak stage A) that is typical of normal ageing. There was a strong correlation between age

A new integrated dual time-point amyloid PET/MRI data analysis method

Energy Technology Data Exchange (ETDEWEB)

Cecchin, Diego; Zucchetta, Pietro; Turco, Paolo; Bui, Franco [University Hospital of Padua, Nuclear Medicine Unit, Department of Medicine - DIMED, Padua (Italy); Barthel, Henryk; Tiepolt, Solveig; Sabri, Osama [Leipzig University, Department of Nuclear Medicine, Leipzig (Germany); Poggiali, Davide; Cagnin, Annachiara; Gallo, Paolo [University Hospital of Padua, Neurology, Department of Neurosciences (DNS), Padua (Italy); Frigo, Anna Chiara [University Hospital of Padua, Biostatistics, Epidemiology and Public Health Unit, Department of Cardiac, Thoracic and Vascular Sciences, Padua (Italy)

2017-11-15

In the initial evaluation of patients with suspected dementia and Alzheimer's disease, there is no consensus on how to perform semiquantification of amyloid in such a way that it: (1) facilitates visual qualitative interpretation, (2) takes the kinetic behaviour of the tracer into consideration particularly with regard to at least partially correcting for blood flow dependence, (3) analyses the amyloid load based on accurate parcellation of cortical and subcortical areas, (4) includes partial volume effect correction (PVEC), (5) includes MRI-derived topographical indexes, (6) enables application to PET/MRI images and PET/CT images with separately acquired MR images, and (7) allows automation. A method with all of these characteristics was retrospectively tested in 86 subjects who underwent amyloid ({sup 18}F-florbetaben) PET/MRI in a clinical setting (using images acquired 90-110 min after injection, 53 were classified visually as amyloid-negative and 33 as amyloid-positive). Early images after tracer administration were acquired between 0 and 10 min after injection, and later images were acquired between 90 and 110 min after injection. PVEC of the PET data was carried out using the geometric transfer matrix method. Parametric images and some regional output parameters, including two innovative ''dual time-point'' indexes, were obtained. Subjects classified visually as amyloid-positive showed a sparse tracer uptake in the primary sensory, motor and visual areas in accordance with the isocortical stage of the topographic distribution of the amyloid plaque (Braak stages V/VI). In patients classified visually as amyloid-negative, the method revealed detectable levels of tracer uptake in the basal portions of the frontal and temporal lobes, areas that are known to be sites of early deposition of amyloid plaques that probably represented early accumulation (Braak stage A) that is typical of normal ageing. There was a strong correlation between

Dual-Tracer PET Using Generalized Factor Analysis of Dynamic Sequences

Science.gov (United States)

Fakhri, Georges El; Trott, Cathryn M.; Sitek, Arkadiusz; Bonab, Ali; Alpert, Nathaniel M.

2013-01-01

Purpose With single-photon emission computed tomography, simultaneous imaging of two physiological processes relies on discrimination of the energy of the emitted gamma rays, whereas the application of dual-tracer imaging to positron emission tomography (PET) imaging has been limited by the characteristic 511-keV emissions. Procedures To address this limitation, we developed a novel approach based on generalized factor analysis of dynamic sequences (GFADS) that exploits spatio-temporal differences between radiotracers and applied it to near-simultaneous imaging of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) (brain metabolism) and 11C-raclopride (D2) with simulated human data and experimental rhesus monkey data. We show theoretically and verify by simulation and measurement that GFADS can separate FDG and raclopride measurements that are made nearly simultaneously. Results The theoretical development shows that GFADS can decompose the studies at several levels: (1) It decomposes the FDG and raclopride study so that they can be analyzed as though they were obtained separately. (2) If additional physiologic/anatomic constraints can be imposed, further decomposition is possible. (3) For the example of raclopride, specific and nonspecific binding can be determined on a pixel-by-pixel basis. We found good agreement between the estimated GFADS factors and the simulated ground truth time activity curves (TACs), and between the GFADS factor images and the corresponding ground truth activity distributions with errors less than 7.3±1.3 %. Biases in estimation of specific D2 binding and relative metabolism activity were within 5.9±3.6 % compared to the ground truth values. We also evaluated our approach in simultaneous dual-isotope brain PET studies in a rhesus monkey and obtained accuracy of better than 6 % in a mid-striatal volume, for striatal activity estimation. Conclusions Dynamic image sequences acquired following near-simultaneous injection of two PET radiopharmaceuticals

Fully automated synthesis of ¹¹C-acetate as tumor PET tracer by simple modified solid-phase extraction purification.

Science.gov (United States)

Tang, Xiaolan; Tang, Ganghua; Nie, Dahong

2013-12-01

Automated synthesis of (11)C-acetate ((11)C-AC) as the most commonly used radioactive fatty acid tracer is performed by a simple, rapid, and modified solid-phase extraction (SPE) purification. Automated synthesis of (11)C-AC was implemented by carboxylation reaction of MeMgBr on a polyethylene Teflon loop ring with (11)C-CO2, followed by acidic hydrolysis with acid and SCX cartridge, and purification on SCX, AG11A8 and C18 SPE cartridges using a commercially available (11)C-tracer synthesizer. Quality control test and animals positron emission tomography (PET) imaging were also carried out. A high and reproducible decay-uncorrected radiochemical yield of (41.0 ± 4.6)% (n=10) was obtained from (11)C-CO2 within the whole synthesis time about 8 min. The radiochemical purity of (11)C-AC was over 95% by high-performance liquid chromatography (HPLC) analysis. Quality control test and PET imaging showed that (11)C-AC injection produced by the simple SPE procedure was safe and efficient, and was in agreement with the current Chinese radiopharmaceutical quality control guidelines. The novel, simple, and rapid method is readily adapted to the fully automated synthesis of (11)C-AC on several existing commercial synthesis module. The method can be used routinely to produce (11)C-AC for preclinical and clinical studies with PET imaging. Copyright © 2013 Elsevier Ltd. All rights reserved.

Metabolic imaging using PET

International Nuclear Information System (INIS)

Kudo, Takashi

2007-01-01

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

Joint estimation of activity and attenuation for PET using pragmatic MR-based prior: application to clinical TOF PET/MR whole-body data for FDG and non-FDG tracers

Science.gov (United States)

Ahn, Sangtae; Cheng, Lishui; Shanbhag, Dattesh D.; Qian, Hua; Kaushik, Sandeep S.; Jansen, Floris P.; Wiesinger, Florian

2018-02-01

Accurate and robust attenuation correction remains challenging in hybrid PET/MR particularly for torsos because it is difficult to segment bones, lungs and internal air in MR images. Additionally, MR suffers from susceptibility artifacts when a metallic implant is present. Recently, joint estimation (JE) of activity and attenuation based on PET data, also known as maximum likelihood reconstruction of activity and attenuation, has gained considerable interest because of (1) its promise to address the challenges in MR-based attenuation correction (MRAC), and (2) recent advances in time-of-flight (TOF) technology, which is known to be the key to the success of JE. In this paper, we implement a JE algorithm using an MR-based prior and evaluate the algorithm using whole-body PET/MR patient data, for both FDG and non-FDG tracers, acquired from GE SIGNA PET/MR scanners with TOF capability. The weight of the MR-based prior is spatially modulated, based on MR signal strength, to control the balance between MRAC and JE. Large prior weights are used in strong MR signal regions such as soft tissue and fat (i.e. MR tissue classification with a high degree of certainty) and small weights are used in low MR signal regions (i.e. MR tissue classification with a low degree of certainty). The MR-based prior is pragmatic in the sense that it is convex and does not require training or population statistics while exploiting synergies between MRAC and JE. We demonstrate the JE algorithm has the potential to improve the robustness and accuracy of MRAC by recovering the attenuation of metallic implants, internal air and some bones and by better delineating lung boundaries, not only for FDG but also for more specific non-FDG tracers such as 68Ga-DOTATOC and 18F-Fluoride.

The role of functional imaging techniques in the dementia

International Nuclear Information System (INIS)

Ryu, Young Hoon

2004-01-01

Evaluation of dementia in patients with early symptoms of cognitive decline is clinically challenging, but the need for early, accurate diagnosis has become more crucial, since several medication for the treatment of mild to moderate Alzheimer' disease are available. Many neurodegenerative diseases produce significant brain function alteration even when structural imaging (CT of MRI) reveal no specific abnormalities. The role of PET and SPECT brain imaging in the initial assessment and differential diagnosis of dementia is beginning to evolve rapidly and growing evidence indicates that appropriate incorporation of PET into the clinical work up can improve diagnostic and prognostic accuracy with respect to Alzheimer's disease, the most common cause of dementia in the geriatric population. In the fast few years, studies comparing neuropathologic examination with PET have established reliable and consistent accuracy for diagnostic evaluations using PET - accuracies substantially exceeding those of comparable studies of diagnostic value of SPECT or of both modalities assessed side by side, or of clinical evaluations done without nuclear imaging. This review deals the role of functional brian imaging techniques in the evaluation of dementias and the role of nuclear neuroimaging in the early detection and diagnosis of Alzheimer's disease

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

International Nuclear Information System (INIS)

Samarin, Andrei; Burger, Cyrill; Crook, David W.; Burger, Irene A.; Schmid, Daniel T.; Schulthess, Gustav K. von; Kuhn, Felix P.; Wollenweber, Scott D.

2012-01-01

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

The role of radionuclide studies in the differential diagnosis of dementia with Lewy Body (DLB)

International Nuclear Information System (INIS)

Brockhuis, B.; Romanowicz, G.; Slawek, J.; Wieczorek, D.; Ussorowska, D.; Derejko, M.

2006-01-01

Dementia with Lewy Body (DLB) is considered to be the second most common (20%) neuropathological cause of degenerative dementia after Alzheimer's disease (AD). Typical clinical features of DLB include a progressive and fluctuating cognitive impairment and visual hallucinations along with Parkinsonian symptoms. Early diagnosis is important in DLB because of dangerous neuroleptic sensitivity which is associated with increased morbidity and mortality. Cholinergic deficit in DLB is more extensive when compared with AD. This might explain the beneficial effect of therapy with cholinesterase inhibitors, with improvement of cognitive and psychiatric functions. The functional neuroimaging with the use of SPECT and PET may contribute to the clinical diagnosis and understanding the possible pathogenesis of DLB. There are many similarities between DLB and AD with pronounced parietotemporal hypoperfusion whereas occipital hypoperfusion is more pronounced in DLB. Using tracers for presynaptic dopamine transporters such as I-123 β-CIT recent studies have found severely impaired dopaminergic function in DLB, similar to Parkinson Disease (PD) but not present in AD. Authors present a review of current literature on the role of SPECT and PET imaging in the diagnosis of DLB and three illustrated cases of probable DLB with rCBF SPECT scanning showing mostly parieto-occipital hypoperfusion. (author)

PET/CT in renal, bladder and testicular cancer

Science.gov (United States)

Bouchelouche, Kirsten; Physician, Chief; Choyke, Peter L.

2015-01-01

Imaging plays an important role in the clinical management of cancer patients. Hybrid imaging with PET/CT is having a broad impact in oncology, and in recent years PET/CT is beginning to have an impact in uro-oncology as well. In both bladder and renal cancer there is a need to study the efficacy of other tracers than F-18 fluorodeoxyglucose (FDG), particularly tracers with only limited renal excretion. Thus, new tracers are being introduced in these malignancies. This review focuses on the clinical role of FDG and other PET agents in renal, bladder and testicular cancer. PMID:26099672

A fast chemoenzymatic synthesis of [11C]-N5,N10-methylenetetrahydrofolate as a potential PET tracer for proliferating cells

International Nuclear Information System (INIS)

Saeed, Muhammad; Tewson, Timothy J.; Erdahl, Colbin E.; Kohen, Amnon

2012-01-01

Introduction: Thymidylate synthase and folate receptors are well-developed targets of cancer therapy. Discovery of a simple and fast method for the conversion of 11 CH 3 Ito[ 11 C]-formaldehyde ( 11 CH 2 O) encouraged us to label the co-factor of this enzyme. Preliminary studies conducted on cell lines have demonstrated a preferential uptake of [11- 14 C]-(R)-N 5 ,N 10 -methylene-5,6,7,8-tetrahydrofolate ( 14 CH 2 H 4 folate) by cancerous cell vs. normal cells from the same organ (Saeed M., Sheff D. and Kohen A. Novel positron emission tomography tracer distinguishes normal from cancerous cells. J Biol Chem 2011;286:33872–33878), pointing out 11 CH 2 H 4 folate as a positron emission tomography (PET) tracer for cancer imaging. Herein we report the synthesis of 11 CH 2 H 4 folate, which may serve as a potential PET tracer. Methods: In a remotely controlled module, methyl iodide ( 11 CH 3 I) was bubbled into a reaction vial containing trimethylamine N-oxide in N,N-Dimethylformamide (DMF) and heated to 70°C for 2 min. Formaldehyde ( 11 CH 2 O) formed after the completion of reaction was then mixed with a solution of freshly prepared tetrahydrofolate (H 4 folate) by using a fast chemoenzymatic approach to accomplish synthesis of 11 CH 2 H 4 folate. Purification of the product was carried out by loading the crude reaction mixture on a SAX cartridge, washing with water to remove unbound impurities and finally eluting with a saline solution. Results: The synthesis and purification of 11 CH 2 H 4 folate were completed within 5 min. High-performance liquid chromatography analysis of the product after SAX purification indicates that more than 90% of the radioactivity that was retained on the SAX cartridge was in 11 CH 2 H 4 folate, with minor ( 11 CH 2 O. Conclusion: We present a fast (∼5 min) synthesis and purification of 11 CH 2 H 4 folate as a potential PET tracer. The final product is received in physiologically compatible buffer (100 mM sodium phosphate, pH 7

Clinical application of positron emission tomography for diagnosis of dementia

International Nuclear Information System (INIS)

Ishii, Kazunari

2002-01-01

Clinical applications of PET studies for dementia are reviewed in this paper. At the mild and moderate stages of Alzheimer's disease (AD), glucose metabolism is reduced not only in the parietotemporal region but also in the posterior cingulate and precuneus. At the advanced stage of AD, there is also a metabolic reduction in the frontal region. In AD patients, glucose metabolism is relatively preserved in the pons, sensorimotor cortices, primary visual cortices, basal ganglia, thalamus and cerebellum. In patients with dementia with Lewy bodies, glucose metabolism in the primary visual cortices is reduced, and this reduction appears to be associated with the reduction pattern in AD patients. In patients with frontotemporal dementia, reduced metabolism in the frontotemporal region is the main feature of this disease, but reduced metabolism in the basal ganglia, and/or parietal metabolic reduction can be associated with the frontotemporal reduction. When corticobasal degeneration is associated with dementia, the reduction pattern of dementia is similar to the reduction pattern in AD and the hallmarks of diagnosing corticobasal degeneration associated with dementia are a reduced metabolism in the primary sensorimotor region and/or basal ganglia and an asymmetric reduction in the two hemispheres. FDG-PET is a very useful tool for the diagnosis of early AD and for the differential diagnosis of dementia. I also describe clinical applications of PET for the diagnosis of dementia in Japan. (author)

Synthesis of 1-[11C]-D,L-homocysteine thiolactone: a potential tracer for myocardial ischemia using PET

International Nuclear Information System (INIS)

Hamacher, K.; Hanus, J.

1989-01-01

The synthesis of 1-[ 11 C]-D,L-homocysteine thiolactone, a potential tracer for PET imaging of ischemic heart regions, is described. The labelling is achieved by reaction of [ 11 C]carbon dioxide with α-lithiated S-(tetrahydro-pyran-2-yl)3-thiopropylisonitrile. Deprotection of the mercapto group and lactonisation of the resulting thioamino acid is accomplished in an acid catalysed reaction. The radiochemical yield obtained is 10 to 15% and the synthesis time, including the HPLC purification is about 45 min. (author)

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

STRATEGIES FOR QUANTIFYING PET IMAGING DATA FROM TRACER STUDIES OF BRAIN RECEPTORS AND ENZYMES.

Energy Technology Data Exchange (ETDEWEB)

Logan, J.

2001-04-02

A description of some of the methods used in neuroreceptor imaging to distinguish changes in receptor availability has been presented in this chapter. It is necessary to look beyond regional uptake of the tracer since uptake generally is affected by factors other than the number of receptors for which the tracer has affinity. An exception is the infusion method producing an equilibrium state. The techniques vary in complexity some requiring arterial blood measurements of unmetabolized tracer and multiple time uptake data. Others require only a few plasma and uptake measurements and those based on a reference region require no plasma measurements. We have outlined some of the limitations of the different methods. Laruelle (1999) has pointed out that test/retest studies to which various methods can be applied are crucial in determining the optimal method for a particular study. The choice of method will also depend upon the application. In a clinical setting, methods not involving arterial blood sampling are generally preferred. In the future techniques for externally measuring arterial plasma radioactivity with only a few blood samples for metabolite correction will extend the modeling options of clinical PET. Also since parametric images can provide information beyond that of ROI analysis, improved techniques for generating such images will be important, particularly for ligands requiring more than a one-compartment model. Techniques such as the wavelet transform proposed by Turkheimer et al. (2000) may prove to be important in reducing noise and improving quantitation.

Investigation of 6-[¹⁸F]-fluoromaltose as a novel PET tracer for imaging bacterial infection.

Directory of Open Access Journals (Sweden)

Gayatri Gowrishankar

Full Text Available Despite advances in the field of nuclear medicine, the imaging of bacterial infections has remained a challenge. The existing reagents suffer from poor sensitivity and specificity. In this study we investigate the potential of a novel PET (positron emission tomography tracer that overcomes these limitations.6-[¹⁸F]-fluoromaltose was synthesized. Its behavior in vitro was evaluated in bacterial and mammalian cultures. Detailed pharmacokinetic and biodistribution profiles for the tracer were obtained from a murine model.6-[¹⁸F]-fluoromaltose is taken up by multiple strains of pathogenic bacteria. It is not taken up by mammalian cancer cell lines. 6-[¹⁸F]-fluoromaltose is retained in infected muscles in a murine model of bacterial myositis. It does not accumulate in inflamed tissue.We have shown that 6-[¹⁸F]-fluoromaltose can be used to image bacterial infection in vivo with high specificity. We believe that this class of agents will have a significant impact on the clinical management of patients.

Comparison between MRI-based attenuation correction methods for brain PET in dementia patients

International Nuclear Information System (INIS)

Cabello, Jorge; Lukas, Mathias; Pyka, Thomas; Nekolla, Stephan G.; Ziegler, Sibylle I.; Rota Kops, Elena; Shah, N. Jon; Ribeiro, Andre; Yakushev, Igor

2016-01-01

The combination of Positron Emission Tomography (PET) with magnetic resonance imaging (MRI) in hybrid PET/MRI scanners offers a number of advantages in investigating brain structure and function. A critical step of PET data reconstruction is attenuation correction (AC). Accounting for bone in attenuation maps (μ-map) was shown to be important in brain PET studies. While there are a number of MRI-based AC methods, no systematic comparison between them has been performed so far. The aim of this work was to study the different performance obtained by some of the recent methods presented in the literature. To perform such a comparison, we focused on [ 18 F]-Fluorodeoxyglucose-PET/MRI neurodegenerative dementing disorders, which are known to exhibit reduced levels of glucose metabolism in certain brain regions. Four novel methods were used to calculate μ-maps from MRI data of 15 patients with Alzheimer's dementia (AD). The methods cover two atlas-based methods, a segmentation method, and a hybrid template/segmentation method. Additionally, the Dixon-based and a UTE-based method, offered by a vendor, were included in the comparison. Performance was assessed at three levels: tissue identification accuracy in the μ-map, quantitative accuracy of reconstructed PET data in specific brain regions, and precision in diagnostic images at identifying hypometabolic areas. Quantitative regional errors of -20-10 % were obtained using the vendor's AC methods, whereas the novel methods produced errors in a margin of ±5 %. The obtained precision at identifying areas with abnormally low levels of glucose uptake, potentially regions affected by AD, were 62.9 and 79.5 % for the two vendor AC methods, the former ignoring bone and the latter including bone information. The precision increased to 87.5-93.3 % in average for the four new methods, exhibiting similar performances. We confirm that the AC methods based on the Dixon and UTE sequences provided by the vendor are inferior

Comparison between MRI-based attenuation correction methods for brain PET in dementia patients

Energy Technology Data Exchange (ETDEWEB)

Cabello, Jorge; Lukas, Mathias; Pyka, Thomas; Nekolla, Stephan G.; Ziegler, Sibylle I. [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Rota Kops, Elena; Shah, N. Jon [Forschungszentrum Juelich GmbH, Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Juelich (Germany); Ribeiro, Andre [Forschungszentrum Juelich GmbH, Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Juelich (Germany); Institute of Biophysics and Biomedical Engineering, Lisbon (Portugal); Yakushev, Igor [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Institute TUM Neuroimaging Center (TUM-NIC), Munich (Germany)

2016-11-15

The combination of Positron Emission Tomography (PET) with magnetic resonance imaging (MRI) in hybrid PET/MRI scanners offers a number of advantages in investigating brain structure and function. A critical step of PET data reconstruction is attenuation correction (AC). Accounting for bone in attenuation maps (μ-map) was shown to be important in brain PET studies. While there are a number of MRI-based AC methods, no systematic comparison between them has been performed so far. The aim of this work was to study the different performance obtained by some of the recent methods presented in the literature. To perform such a comparison, we focused on [{sup 18}F]-Fluorodeoxyglucose-PET/MRI neurodegenerative dementing disorders, which are known to exhibit reduced levels of glucose metabolism in certain brain regions. Four novel methods were used to calculate μ-maps from MRI data of 15 patients with Alzheimer's dementia (AD). The methods cover two atlas-based methods, a segmentation method, and a hybrid template/segmentation method. Additionally, the Dixon-based and a UTE-based method, offered by a vendor, were included in the comparison. Performance was assessed at three levels: tissue identification accuracy in the μ-map, quantitative accuracy of reconstructed PET data in specific brain regions, and precision in diagnostic images at identifying hypometabolic areas. Quantitative regional errors of -20-10 % were obtained using the vendor's AC methods, whereas the novel methods produced errors in a margin of ±5 %. The obtained precision at identifying areas with abnormally low levels of glucose uptake, potentially regions affected by AD, were 62.9 and 79.5 % for the two vendor AC methods, the former ignoring bone and the latter including bone information. The precision increased to 87.5-93.3 % in average for the four new methods, exhibiting similar performances. We confirm that the AC methods based on the Dixon and UTE sequences provided by the vendor are

Radiosynthesis and initial characterization of a PDE10A specific PET tracer [18 F]AMG 580 in non-human primates

International Nuclear Information System (INIS)

Hwang, Dah-Ren; Hu, Essa; Allen, Jennifer R.; Davis, Carl; Treanor, James; Miller, Silke; Chen, Hang; Shi, Bingzhi; Narayanan, Tanjorie K.; Barret, Olivier; Alagille, David; Yu, Zhigang; Slifstein, Mark

2015-01-01

Introduction: Phosphodiesterase 10A (PDE10A) is an intracellular enzyme responsible for the breakdown of cyclic nucleotides which are important second messengers for neurotransmission. Inhibition of PDE10A has been identified as a potential target for treatment of various neuropsychiatric disorders. To assist drug development, we have identified a selective PDE10A positron emission tomography (PET) tracer, AMG 580. We describe here the radiosynthesis of [ 18 F]AMG 580 and in vitro and in vivo characterization results. Methods: The potency and selectivity were determined by in vitro assay using [ 3 H]AMG 580 and baboon brain tissues. [ 18 F]AMG 580 was prepared by a 1-step [ 18 F]fluorination procedure. Dynamic brain PET scans were performed in non-human primates. Regions-of-interest were defined on individuals’ MRIs and transferred to the co-registered PET images. Data were analyzed using two tissue compartment analysis (2TC), Logan graphical (Logan) analysis with metabolite-corrected input function and the simplified reference tissue model (SRTM) method. A PDE10A inhibitor and unlabeled AMG 580 were used to demonstrate the PDE10A specificity. K D was estimated by Scatchard analysis of high and low affinity PET scans. Results: AMG 580 has an in vitro K D of 71.9 pM. Autoradiography showed specific uptake in striatum. Mean activity of 121 ± 18 MBq was used in PET studies. In Rhesus, the baseline BP ND for putamen and caudate was 3.38 and 2.34, respectively, via 2TC, and 3.16, 2.34 via Logan, and 2.92, and 2.01 via SRTM. A dose dependent decrease of BP ND was observed by the pre-treatment with a PDE10A inhibitor. In baboons, 0.24 mg/kg dose of AMG 580 resulted in about 70% decrease of BP ND . The in vivo K D of [ 18 F]AMG 580 was estimated to be around 0.44 nM in baboons. Conclusion: [ 18 F]AMG 580 is a selective and potent PDE10A PET tracer with excellent specific striatal binding in non-human primates. It warrants further evaluation in humans

Clinical application of positron emission tomography for diagnosis of dementia

Energy Technology Data Exchange (ETDEWEB)

Ishii, Kazunari [Hyogo Brain and Heart Center, Himeji (Japan)

2002-12-01

Clinical applications of PET studies for dementia are reviewed in this paper. At the mild and moderate stages of Alzheimer's disease (AD), glucose metabolism is reduced not only in the parietotemporal region but also in the posterior cingulate and precuneus. At the advanced stage of AD, there is also a metabolic reduction in the frontal region. In AD patients, glucose metabolism is relatively preserved in the pons, sensorimotor cortices, primary visual cortices, basal ganglia, thalamus and cerebellum. In patients with dementia with Lewy bodies, glucose metabolism in the primary visual cortices is reduced, and this reduction appears to be associated with the reduction pattern in AD patients. In patients with frontotemporal dementia, reduced metabolism in the frontotemporal region is the main feature of this disease, but reduced metabolism in the basal ganglia, and/or parietal metabolic reduction can be associated with the frontotemporal reduction. When corticobasal degeneration is associated with dementia, the reduction pattern of dementia is similar to the reduction pattern in AD and the hallmarks of diagnosing corticobasal degeneration associated with dementia are a reduced metabolism in the primary sensorimotor region and/or basal ganglia and an asymmetric reduction in the two hemispheres. FDG-PET is a very useful tool for the diagnosis of early AD and for the differential diagnosis of dementia. I also describe clinical applications of PET for the diagnosis of dementia in Japan. (author)

New PET tracers for cerebral dopamine: Should 6-[18f]fluoro-dopa be replaced?

International Nuclear Information System (INIS)

Firnau, G.; Chirakal, R.; Chen, J.J.; Murthy, D.; Nahmias, C.; Garnett, E.S.

1993-01-01

The visualization with PET of dopaminergic terminals in the human brain has been accomplished by a variety of approaches using β + -labelled substrates 1. for Aromatic L-Amino acid Decarboxylase, AADC, (6-[ 18 F]fluoro-L-dopa, FD; 6-[ 18 F]fluoro-L-meta-tyrosine, FmT; L-[ 11 C]Dopa); and β + -labelled inhibitors 2. for reuptake transporter ([ 11 C]Cocain, [ 11 C]WIN 35,428); 3. for Monoamine Oxidase-B ([ 11 C]deprenyl); 4. for the Vesicular uptake site ([ 11 C]tetrabenzamine). The enzyme approach with FD has been particularly successful in providing important insights into Parkinson's disease and dystonias. The extraction of quantitative data from FD/PET studies in humans is complicated by the formation of O-methylFD in the periphery, which, like FD, also enters the brain. Following the suggestion by deJesus (1988) to use a labelled meta-tyrosine (substrate for AADC but not COMT) the authors have synthesized FmT, developed it into a radiopharmaceutical (toxicology and radiation dose in humans) and studied the intracerebral distribution in man and the metabolites in monkeys. They found that FmT's peripheral metabolite does not enter the brain. Unlike FD, FmT delineates with greater clarity the dopaminergic terminals and cells including those in the substantia nigra that, so far, could not be investigated with any other PET tracer. Thus, FmT appears to be superior to FD

[F-18]fluoro-meta-L-tyrosine is a better PET tracer than [F-18]fluoro-L-dopa for the delineation of dopaminergic structures in the human brain

International Nuclear Information System (INIS)

Firnau, G.; Chirakal, R.; Nahmias, C.; Garnett, E.S.

1990-01-01

Fluorine-18 labelled fluoro-m-L-tyrosine (FmLtyr) and fluoro-L-Dopa (F-Dopa) have been synthesized, and the utility of FmLtyr for PET investigations of dopaminergic brain regions has been compared to that of F-dopa. Experimental results from both monkey and human studies indicate that FmLtyr gives better delineation of striatum, and is a better PET tracer than F-dopa

Issues in quantification of registered respiratory gated PET/CT in the lung

Science.gov (United States)

Cuplov, Vesna; Holman, Beverley F.; McClelland, Jamie; Modat, Marc; Hutton, Brian F.; Thielemans, Kris

2018-01-01

PET/CT quantification of lung tissue is limited by several difficulties: the lung density and local volume changes during respiration, the anatomical mismatch between PET and CT and the relative contributions of tissue, air and blood to the PET signal (the tissue fraction effect). Air fraction correction (AFC) has been shown to improve PET image quantification in the lungs. Methods to correct for the movement and anatomical mismatch involve respiratory gating and image registration techniques. While conventional registration methods only account for spatial mismatch, the Jacobian determinant of the deformable registration transformation field can be used to estimate local volume changes and could therefore potentially be used to correct (i.e. Jacobian Correction, JC) the PET signal for changes in concentration due to local volume changes. This work aims to investigate the relationship between variations in the lung due to respiration, specifically density, tracer concentration and local volume changes. In particular, we study the effect of AFC and JC on PET quantitation after registration of respiratory gated PET/CT patient data. Six patients suffering from lung cancer with solitary pulmonary nodules underwent 18 F-FDG PET/cine-CT. The PET data were gated into six respiratory gates using displacement gating based on a real-time position management (RPM) signal and reconstructed with matched gated CT. The PET tracer concentration and tissue density were extracted from registered gated PET and CT images before and after corrections (AFC or JC) and compared to the values from the reference images. Before correction, we observed a linear correlation between the PET tracer concentration values and density. Across all gates and patients, the maximum relative change in PET tracer concentration before (after) AFC was found to be 16.2% (4.1%) and the maximum relative change in tissue density and PET tracer concentration before (after) JC was found to be 17.1% (5.5%) and 16

Conspicuity of FDG-aid osseous lesions on PET/MRI versus PET/CT: A quantitative and visual analysis

Energy Technology Data Exchange (ETDEWEB)

Fraum, Tyler J.; Fowler, Kathryn J.; Mcconathy, Jonathan [Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis (United States)

2016-09-15

Because standard MRI-based attenuation correction (AC) does not account for the attenuation of photons by cortical bone, PET/MRI may have reduced sensitivity for FDG-avid focal bone lesions (FFBLs). This study evaluates whether MRI-based AC compromises detection of FFBLs, by comparing their conspicuity both quantitatively and qualitatively on PET/MRI versus PET/CT. One hundred ninety general oncology patients underwent whole-body PET/CT followed by whole-body PET/MRI, utilizing the same FDG dose. Thirteen patients with a total of 50 FFBLs were identified. Using automated contouring software, a volumetric contour was generated for each FFBL. Adjacent regions of normal background bone (BB) were selected manually. For each contour, SUV-max and SUV-mean were determined. Lesion-to-background SUV ratios served as quantitative metrics of conspicuity. Additionally, two blinded readers evaluated the relative conspicuity of FFBLs on PET images derived from MRI-based AC versus CT-based AC. Visibility of an anatomic correlate for FFBLs on the corresponding CT and MR images was also assessed. SUV-mean was lower on PET/MRI for both FFBLs (-6.5 %, p = 0.009) and BB (-20.5 %, p < 0.001). SUV-max was lower on PET/MRI for BB (-14.2 %, p = 0.002) but not for FFBLs (-6.2 %, p = 0.068). The ratio of FFBL SUV-mean to BB SUV-mean was higher for PET/MRI (+29.5 %, p < 0.001). Forty of 50 lesions (80 %) were visually deemed to be of equal or greater conspicuity on PET images derived from PET/MRI. Thirty-five of 50 FFBLs (70 %) had CT correlates, while 40/50 FFBLs (80 %) had a correlate on at least one MRI sequence. The mean interval from tracer administration to imaging was longer (p < 0.001) for PET/MRI (127 v. 62 min). Both FFBLs and BB had lower mean SUVs on PET/MRI than PET/CT. This finding was likely in part due to differences in the handling of cortical bone by MRI-based AC versus CT-based AC. Despite this systematic bias, FFBLs had greater conspicuity on PET

Radiosynthesis and in vivo evaluation of a series of substituted {sup 11}C-phenethylamines as 5-HT{sub 2A} agonist PET tracers

Energy Technology Data Exchange (ETDEWEB)

Ettrup, Anders; Santini, Martin A.; Palner, Mikael; Knudsen, Gitte M. [Copenhagen University Hospital, Neurobiology Research Unit, Copenhagen (Denmark); Copenhagen University Hospital, Rigshospitalet, Center for Integrated Molecular Brain Imaging (Cimbi), Copenhagen (Denmark); Hansen, Martin; Paine, James; Kristensen, Jesper; Begtrup, Mikael [University of Copenhagen, Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Copenhagen (Denmark); Copenhagen University Hospital, Rigshospitalet, Center for Integrated Molecular Brain Imaging (Cimbi), Copenhagen (Denmark); Gillings, Nic; Herth, Matthias M.; Madsen, Jacob [Copenhagen University Hospital, Rigshospitalet, PET and Cyclotron Unit, Copenhagen (Denmark); Copenhagen University Hospital, Rigshospitalet, Center for Integrated Molecular Brain Imaging (Cimbi), Copenhagen (Denmark); Lehel, Szabolcs [Copenhagen University Hospital, Rigshospitalet, PET and Cyclotron Unit, Copenhagen (Denmark)

2011-04-15

Positron emission tomography (PET) imaging of serotonin 2A (5-HT{sub 2A}) receptors with agonist tracers holds promise for the selective labelling of 5-HT{sub 2A} receptors in their high-affinity state. We have previously validated [{sup 11}C]Cimbi-5 and found that it is a 5-HT{sub 2A} receptor agonist PET tracer. In an attempt to further optimize the target-to-background binding ratio, we modified the chemical structure of the phenethylamine backbone and carbon-11 labelling site of [{sup 11}C]Cimbi-5 in different ways. Here, we present the in vivo validation of nine novel 5-HT{sub 2A} receptor agonist PET tracers in the pig brain. Each radiotracer was injected intravenously into anaesthetized Danish Landrace pigs, and the pigs were subsequently scanned for 90 min in a high-resolution research tomography scanner. To evaluate 5-HT{sub 2A} receptor binding, cortical nondisplaceable binding potentials (BP{sub ND}) were calculated using the simplified reference tissue model with the cerebellum as a reference region. After intravenous injection, all compounds entered the brain and distributed preferentially into the cortical areas, in accordance with the known 5-HT{sub 2A} receptor distribution. The largest target-to-background binding ratio was found for [{sup 11}C]Cimbi-36 which also had a high brain uptake compared to its analogues. The cortical binding of [{sup 11}C]Cimbi-36 was decreased by pretreatment with ketanserin, supporting 5-HT{sub 2A} receptor selectivity in vivo. [{sup 11}C]Cimbi-82 and [{sup 11}C]Cimbi-21 showed lower cortical BP{sub ND}, while [{sup 11}C]Cimbi-27, [{sup 11}C]Cimbi-29, [{sup 11}C]Cimbi-31 and [{sup 11}C]Cimbi-88 gave rise to cortical BP{sub ND} similar to that of [{sup 11}C]Cimbi-5. [{sup 11}C]Cimbi-36 is currently the most promising candidate for investigation of 5-HT{sub 2A} receptor agonist binding in the living human brain with PET. (orig.)

Quantitative assessment of dynamic PET imaging data in cancer imaging.

Science.gov (United States)

Muzi, Mark; O'Sullivan, Finbarr; Mankoff, David A; Doot, Robert K; Pierce, Larry A; Kurland, Brenda F; Linden, Hannah M; Kinahan, Paul E

2012-11-01

Clinical imaging in positron emission tomography (PET) is often performed using single-time-point estimates of tracer uptake or static imaging that provides a spatial map of regional tracer concentration. However, dynamic tracer imaging can provide considerably more information about in vivo biology by delineating both the temporal and spatial pattern of tracer uptake. In addition, several potential sources of error that occur in static imaging can be mitigated. This review focuses on the application of dynamic PET imaging to measuring regional cancer biologic features and especially in using dynamic PET imaging for quantitative therapeutic response monitoring for cancer clinical trials. Dynamic PET imaging output parameters, particularly transport (flow) and overall metabolic rate, have provided imaging end points for clinical trials at single-center institutions for years. However, dynamic imaging poses many challenges for multicenter clinical trial implementations from cross-center calibration to the inadequacy of a common informatics infrastructure. Underlying principles and methodology of PET dynamic imaging are first reviewed, followed by an examination of current approaches to dynamic PET image analysis with a specific case example of dynamic fluorothymidine imaging to illustrate the approach. Copyright © 2012 Elsevier Inc. All rights reserved.

Cholinergic imaging in dementia spectrum disorders

Energy Technology Data Exchange (ETDEWEB)

Roy, Roman; Niccolini, Flavia; Pagano, Gennaro; Politis, Marios [Institute of Psychiatry, Psychology and Neuroscience, King' s College London, Neurodegeneration Imaging Group, Department of Basic and Clinical Neuroscience, London (United Kingdom)

2016-07-15

The multifaceted nature of the pathology of dementia spectrum disorders has complicated their management and the development of effective treatments. This is despite the fact that they are far from uncommon, with Alzheimer's disease (AD) alone affecting 35 million people worldwide. The cholinergic system has been found to be crucially involved in cognitive function, with cholinergic dysfunction playing a pivotal role in the pathophysiology of dementia. The use of molecular imaging such as SPECT and PET for tagging targets within the cholinergic system has shown promise for elucidating key aspects of underlying pathology in dementia spectrum disorders, including AD or parkinsonian dementias. SPECT and PET studies using selective radioligands for cholinergic markers, such as [{sup 11}C]MP4A and [{sup 11}C]PMP PET for acetylcholinesterase (AChE), [{sup 123}I]5IA SPECT for the α{sub 4}β{sub 2} nicotinic acetylcholine receptor and [{sup 123}I]IBVM SPECT for the vesicular acetylcholine transporter, have been developed in an attempt to clarify those aspects of the diseases that remain unclear. This has led to a variety of findings, such as cortical AChE being significantly reduced in Parkinson's disease (PD), PD with dementia (PDD) and AD, as well as correlating with certain aspects of cognitive function such as attention and working memory. Thalamic AChE is significantly reduced in progressive supranuclear palsy (PSP) and multiple system atrophy, whilst it is not affected in PD. Some of these findings have brought about suggestions for the improvement of clinical practice, such as the use of a thalamic/cortical AChE ratio to differentiate between PD and PSP, two diseases that could overlap in terms of initial clinical presentation. Here, we review the findings from molecular imaging studies that have investigated the role of the cholinergic system in dementia spectrum disorders. (orig.)

Cholinergic imaging in dementia spectrum disorders

International Nuclear Information System (INIS)

Roy, Roman; Niccolini, Flavia; Pagano, Gennaro; Politis, Marios

2016-01-01

The multifaceted nature of the pathology of dementia spectrum disorders has complicated their management and the development of effective treatments. This is despite the fact that they are far from uncommon, with Alzheimer's disease (AD) alone affecting 35 million people worldwide. The cholinergic system has been found to be crucially involved in cognitive function, with cholinergic dysfunction playing a pivotal role in the pathophysiology of dementia. The use of molecular imaging such as SPECT and PET for tagging targets within the cholinergic system has shown promise for elucidating key aspects of underlying pathology in dementia spectrum disorders, including AD or parkinsonian dementias. SPECT and PET studies using selective radioligands for cholinergic markers, such as [ 11 C]MP4A and [ 11 C]PMP PET for acetylcholinesterase (AChE), [ 123 I]5IA SPECT for the α 4 β 2 nicotinic acetylcholine receptor and [ 123 I]IBVM SPECT for the vesicular acetylcholine transporter, have been developed in an attempt to clarify those aspects of the diseases that remain unclear. This has led to a variety of findings, such as cortical AChE being significantly reduced in Parkinson's disease (PD), PD with dementia (PDD) and AD, as well as correlating with certain aspects of cognitive function such as attention and working memory. Thalamic AChE is significantly reduced in progressive supranuclear palsy (PSP) and multiple system atrophy, whilst it is not affected in PD. Some of these findings have brought about suggestions for the improvement of clinical practice, such as the use of a thalamic/cortical AChE ratio to differentiate between PD and PSP, two diseases that could overlap in terms of initial clinical presentation. Here, we review the findings from molecular imaging studies that have investigated the role of the cholinergic system in dementia spectrum disorders. (orig.)

Fluorinated tracers for imaging cancer with positron emission tomography

International Nuclear Information System (INIS)

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

2004-01-01

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

Differential diagnosis of neurodegenerative dementias with nuclear medicine methods

International Nuclear Information System (INIS)

Kluge, R.

2015-01-01

Full text: Neurodegenerative dementias (NDD) are characterized by insidious onset and gradual progression of cognitive dysfunction, initially relatively focal with respect to cognitive domains and brain regions involved. Nuclear medicine techniques help to clarify differential diagnoses of syndromes such as Alzheimer’s disease (AD), dementia with Lewy bodies (DlB), posterior cortical atrophy (PCA), logopenic primary progressive aphasia (PPA), agrammatic PPA, semantic dementia (SD), behavioral variant frontotemporal dementia (bvFTD) and progressive supranuclear palsy syndrome (PSPS). The process of pathologic changes in the brain may start decades before first clinical symptoms become evident. An early diagnosis already in the pre-clinical phase of the diseases will be of immense importance when expected effective therapeutic options have been introduced. NDDs are histopathologically characterized by accumulation of pathological proteins in the brain like beta amyloid or protein tau. While radiotracers for labeling of protein tau are in preclinical evaluation, different radiotracers labeling amyloid plaques ([11C]PIB, [18F]Florbetapir (Amyvid, Fa. EliLilly), [18F]Florbetaben (Neuraceq, Fa. Piramal), [18F]Flutemetamol (vVzamyl, Fa. Ge) have already been established in clinical use during the last years. In AD these tracers are intensively accumulated in the whole cortical brain. Even an early disease can be excluded in case of a negative amyloid PET. The method is, however, not highly specific since amyloid plaques may also be present in DlB (70 – 80%), FTD (30%) orlogopenicPPA (100%). Neuronal dysfunction goes along with decreased glucose consumption. Different diseases are characterized by different topographical zones of reduced [18F]FDG uptake. In AD the posterior cingular, temporopariatal and (later) frontal cortex are affected, in DlB the pattern is similar, including the occipital cortex, in FTD the frontal cortex is affected, in nonfluent PPA the

Fully automated synthesis of 11C-acetate as tumor PET tracer by simple modified solid-phase extraction purification

International Nuclear Information System (INIS)

Tang, Xiaolan; Tang, Ganghua; Nie, Dahong

2013-01-01

Introduction: Automated synthesis of 11 C-acetate ( 11 C-AC) as the most commonly used radioactive fatty acid tracer is performed by a simple, rapid, and modified solid-phase extraction (SPE) purification. Methods: Automated synthesis of 11 C-AC was implemented by carboxylation reaction of MeMgBr on a polyethylene Teflon loop ring with 11 C-CO 2 , followed by acidic hydrolysis with acid and SCX cartridge, and purification on SCX, AG11A8 and C18 SPE cartridges using a commercially available 11 C-tracer synthesizer. Quality control test and animals positron emission tomography (PET) imaging were also carried out. Results: A high and reproducible decay-uncorrected radiochemical yield of (41.0±4.6)% (n=10) was obtained from 11 C-CO 2 within the whole synthesis time about 8 min. The radiochemical purity of 11 C-AC was over 95% by high-performance liquid chromatography (HPLC) analysis. Quality control test and PET imaging showed that 11 C-AC injection produced by the simple SPE procedure was safe and efficient, and was in agreement with the current Chinese radiopharmaceutical quality control guidelines. Conclusion: The novel, simple, and rapid method is readily adapted to the fully automated synthesis of 11 C-AC on several existing commercial synthesis module. The method can be used routinely to produce 11 C-AC for preclinical and clinical studies with PET imaging. - Highlights: • A fully automated synthesis of 11 C-acetate by simple modified solid-phase extraction purification has been developed. • Typical non-decay-corrected yields were (41.0±4.6)% (n=10) • Radiochemical purity was determined by radio-HPLC analysis on a C18 column using the gradient program, instead of expensive organic acid column or anion column. • QC testing (RCP>99%)

Early AIDS dementia complex

International Nuclear Information System (INIS)

Mountz, J.M.; Speed, N.M.; Adams, K.; Schwartz, J.A.; Gross, M.D.; Ostrow, D.G.

1988-01-01

A frequent complication of the acquired immunodeficiency syndrome (AIDS) is AIDS dementia complex (ADC). The authors evaluated seven patients with AIDS (aged 28-55 years, all male) for ADC by psychiatric evaluation, neuropsychological testing, CT scanning, and IMP-SPECT. Six of seven patients exhibited cognitive or behavioral abnormalities. Neuropsychological testing showed general deficits but no cases of explicit dementia. SPECT showed marked abnormalities in two cases: posterior temporal-parietal diminution of tracer uptake in one case (posterior/anterior=0.81) and marked right/left subcortical asymmetry (1.17) in the other. In three additional cases there was asymmetric tracer uptake in the subcortical and parietal regions. CT findings were normal in all seven cases. The authors conclude that functional imaging with the use of IMP-SPECT may be a useful method to follow ADC progression and response to therapy

Bone formation rather than inflammation reflects Ankylosing Spondylitis activity on PET-CT: a pilot study

OpenAIRE

Bruijnen, Stefan TG; van der Weijden, Mignon AC; Klein, Joannes P; Hoekstra, Otto S; Boellaard, Ronald; van Denderen, J Christiaan; Dijkmans, Ben AC; Voskuyl, Alexandre E; van der Horst-Bruinsma, Irene E; van der Laken, Conny J

2012-01-01

Introduction Positron Emission Tomography - Computer Tomography (PET-CT) is an interesting imaging technique to visualize Ankylosing Spondylitis (AS) activity using specific PET tracers. Previous studies have shown that the PET tracers [18F]FDG and [11C](R)PK11195 can target inflammation (synovitis) in rheumatoid arthritis (RA) and may therefore be useful in AS. Another interesting tracer for AS is [18F]Fluoride, which targets bone formation. In a pilot setting, the potential of PET-CT in ima...

Adapting MR-BrainPET scans for comparison with conventional PET: experiences with dynamic FET-PET in brain tumours

Energy Technology Data Exchange (ETDEWEB)

Lohmann, Philipp; Herzog, Hans; Kops, Elena Rota; Stoffels, Gabriele; Filss, Christian [Institute of Neuroscience and Medicine (INM-3,-4,-5), Forschungszentrum Juelich, Juelich (Germany); Galldiks, Norbert [Institute of Neuroscience and Medicine (INM-3,-4,-5), Forschungszentrum Juelich, Juelich (Germany); Department of Neurology, University of Cologne, Cologne (Germany); Coenen, Heinrich H; Shah, N Jon; Langen, Karl-Josef [Institute of Neuroscience and Medicine (INM-3,-4,-5), Forschungszentrum Juelich, Juelich (Germany)

2014-07-29

Imaging results from subsequent measurements (preclinical 3T MR-BrainPET, HR+) are compared. O-(2-[{sup 18}F]fluoroethyl)-L-tyrosine (FET) may exhibit non-uniform tracer uptake in gliomas. The aim was to analyse and adapt the physical properties of the scanners and study variations of biological tumour volume (BTV) in early and late FET-PET.

[1-11C]octanoate as a PET tracer for studying ischemic stroke. Evaluation in a canine model of thromboembolic stroke with positron emission tomography

International Nuclear Information System (INIS)

Kuge, Yuji; Kawashima, Hidefumi; Minematsu, Kazuo

2000-01-01

Octanoate is taken up by the brain and converted in astrocytes to glutamine through the TCA cycle after β-oxidation. Consequently, [1- 11 C]octanoate might serve as a useful positron emission tomography (PET) probe for studying cerebral oxidative metabolism and/or astroglial functions. The present study attempted to evaluate the utility of using [1- 11 C]octanoate as a PET tracer for imaging and evaluating the pathophysiology of ischemic stroke. We used a canine model of thromboembolic stroke. Five male beagle dogs were implanted with an indwelling catheter in the left internal carotid artery. A single autologous blood clot was injected into the left internal carotid artery through the catheter. The brain distribution of [1- 11 C]octanoate and cerebral blood flow (CBF) were determined 24 h after insult using a high resolution PET scanner. Post mortem brain regions unstained with 2, 3, 5-triphenyltetrazolium chloride (TTC) were defined as infarcts. In the region of an infarct, accumulation of [1- 11 C]octanoate decreased concurrently with CBF reduction. In contrast, normal accumulation of [1- 11 C]octanoate was observed in ischemic but vital regions, suggesting that an increased accumulation of [1- 11 C]octanoate relative to CBF takes place in these regions. In conclusion, [1- 11 C]octanoate accumulated in ischemic but vital regions, indicating that [1- 11 C]octanoate is a potentially useful PET tracer for imaging and evaluating the pathophysiology of ischemic stroke. (author)

Functional neuroimaging of Alzheimer's disease and other dementias

International Nuclear Information System (INIS)

Wang Ruimin

2001-01-01

Dementing illnesses comprise Alzheimer's disease (AD), Pick's disease, Multi-infarct dementia (MID) and other neurological disorders. These diseases have different clinical characters respectively. Neuropsychological examinations can help to diagnose and differential diagnose dementias. The development of neuroimaging dementias is more and more rapid. 18 F-FDG PET method shows neo-cortical hypometabolism occurring in the biparietal-temporal lobes and left-right asymmetry of AD patients in the early stage. It can also differential diagnose Ad from other dementias

PET and PET-CT. State of the art and future prospects

International Nuclear Information System (INIS)

Fanti, Stefano; Franchi, Roberto; Battista, Giuseppe; Monetti, Nino; Canini, Romeo

2005-01-01

Fluoro-deoxyglucose positron emission tomography (FDG PET) enables the in vivo study of tissue metabolism, and thus is able to identify malignant tumours as hypermetabolic lesions by an increase in tracer uptake. Many papers have demonstrated both the relevant impact of FDG PET on staging of many cancers and the superior accuracy of the technique compared with conventional diagnostic methods for pre-treatment evaluation, therapy response evaluation and relapse identification. In particular PET was found useful in identifying lymph nodal and metastatic spread. thus altering patient management in more than 30% of cases. PET images, however, provide limited anatomical data, which in regions such as the head and neck, mediastinum and pelvic cavity is a significant drawback. The exact localization of lesions may also be difficult in some cases, on the basis of PET images alone. The introduction of combined PET-computed tomography (PET-CT) scanners enables the almost simultaneous acquisition of transmission and emission images, thus obtaining optimal fusion images in a very short time. PET-CT fusion images enable lesions to be located, reducing false positive studies and increasing accuracy; the overall duration of examination may also be reduced. On the basis of both literature data and our experience we established the clinical indications when PET-CT may be particularly useful, in comparison with PET alone. It should also be underlined that the use of PET-CT is almost mandatory for new traces such as C-choline and C-methionine; these new tracers may be applied for studying tumours not assessable with FDG, such as prostate cancer. In conclusion PET-CT is at present the most advanced method for metabolic imaging, and is capable of precisely localizing and assessing tumours; fusion images reduce false positive and inconclusive studies, thus increasing diagnostic accuracy [it

[18F]FE rate at SUPPY: a suitable PET tracer for the adenosine A3 receptor? An in vivo study in rodents

International Nuclear Information System (INIS)

Haeusler, Daniela; Zeilinger, Markus; Wadsak, Wolfgang; Hacker, Marcus; Mitterhauser, Markus; Kuntner, Claudia; Wanek, Thomas; Langer, Oliver; Nics, Lukas; Savli, Markus; Lanzenberger, Rupert R.; Karagiannis, Panagiotis; Shanab, Karem; Spreitzer, Helmut

2015-01-01

The adenosine A 3 receptor (A3R) is involved in cardiovascular, neurological and tumour-related pathologies and serves as an exceptional pharmaceutical target in the clinical setting. A3R antagonists are considered antiinflammatory, antiallergic and anticancer agents, and to have potential for the treatment of asthma, COPD, glaucoma and stroke. Hence, an appropriate A3R PET tracer would be highly beneficial for the diagnosis and therapy monitoring of these diseases. Therefore, in this preclinical in vivo study we evaluated the potential as a PET tracer of the A3R antagonist [ 18 F]FE rate at SUPPY. Rats were injected with [ 18 F]FE rate at SUPPY for baseline scans and blocking scans (A3R with MRS1523 or FE rate at SUPPY, P-gp with tariquidar; three animals each). Additionally, metabolism was studied in plasma and brain. In a preliminary experiment in a mouse xenograft model (mice injected with cells expressing the human A3R; three animals), the animals received [ 18 F]FE rate at SUPPY and [ 18 F]FDG. Dynamic PET imaging was performed (60 min in rats, 90 min in xenografted mice). In vitro stability of [ 18 F]FE rate at SUPPY in human and rat plasma was also evaluated. [ 18 F]FE rate at SUPPY showed high uptake in fat-rich regions and low uptake in the brain. Pretreatment with MRS1523 led to a decrease in [ 18 F]FE rate at SUPPY uptake (p = 0.03), and pretreatment with the P-gp inhibitor tariquidar led to a 1.24-fold increase in [ 18 F]FE rate at SUPPY uptake (p = 0.09) in rat brain. There was no significant difference in metabolites in plasma and brain in the treatment groups. However, plasma concentrations of [ 18 F]FE rate at SUPPY were reduced to levels similar to those in rat brain after blocking. In contrast to [ 18 F]FDG uptake (p = 0.12), the xenograft model showed significantly increased uptake of [ 18 F]FE rate at SUPPY in the tissue masses from CHO cells expressing the human A3R (p = 0.03). [ 18 F]FE rate at SUPPY was stable in human plasma. Selective and

PET/CT studies of multiple myeloma using {sup 18}F-FDG and {sup 18}F-NaF: comparison of distribution patterns and tracers' pharmacokinetics

Energy Technology Data Exchange (ETDEWEB)

Sachpekidis, Christos [Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); German Cancer Research Center, Medical PET Group - Biological Imaging Clinical Cooperation Unit Nuclear Medicine, Heidelberg (Germany); Goldschmidt, Hartmut; Hose, Dirk [University of Heidelberg, Medical Clinic V, Heidelberg (Germany); National Center for Tumor Diseases Heidelberg, Heidelberg (Germany); Pan, Leyun; Cheng, Caixia; Dimitrakopoulou-Strauss, Antonia [Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); Kopka, Klaus [German Cancer Research Center, Division of Radiopharmaceutical Chemistry, Heidelberg (Germany); Haberkorn, Uwe [Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); University of Heidelberg, Division of Nuclear Medicine, Heidelberg (Germany)

2014-07-15

The aim of this prospective study is to evaluate the combined use of fluorine-18 fluorodeoxyglucose ({sup 18}F-FDG) and fluorine-18 sodium fluoride ({sup 18}F-NaF) PET/CT in the skeletal assessment of patients with multiple myeloma (MM) and to compare the efficacy of these two PET tracers regarding detection of myeloma-indicative osseous lesions. The study includes 60 patients with multiple myeloma (MM) diagnosed according to standard criteria. All patients underwent dynamic (dPET/CT) scanning of the pelvis as well as whole body PET/CT studies with both tracers. The interval between the two exams was one day. Sites of focal increased {sup 18}F-FDG uptake were considered as highly suspicious of myelomatous involvement. The lesions detected on the {sup 18}F-NaF PET/CT scans were then correlated with those detected on {sup 18}F-FDG PET/CT, which served as a reference. Moreover, the {sup 18}F-FDG PET/CT results were also correlated with the low-dose CT findings. The evaluation of dPET/CT studies was based on qualitative evaluation, SUV calculation, and quantitative analysis based on a 2-tissue compartment model and a non-compartmental approach. Whole body {sup 18}F-FDG PET/CT revealed approximately 343 focal lesions while {sup 18}F-NaF PET/CT revealed 135 MM-indicative lesions (39 % correlation). CT demonstrated 150 lesions that correlated with those in {sup 18}F-FDG PET/CT (44 % correlation). Six patients demonstrated a diffuse pattern of disease with {sup 18}F-FDG, while 15 of them had a mixed (diffuse and focal) pattern of skeletal {sup 18}F-FDG uptake. A high number of degenerative, traumatic and arthritic disease lesions were detected with {sup 18}F-NaF PET/CT. In three patients with multiple focal {sup 18}F-FDG-uptake, {sup 18}F-NaF PET/CT failed to demonstrate any bone lesion. The dPET/CT scanning of the pelvic area with {sup 18}F-FDG and {sup 18}F-NaF revealed 77 and 24 MM-indicative lesions, respectively. Kinetic analysis of {sup 18}F-FDG revealed the

Amyloid PET in pseudotumoral multiple sclerosis.

Science.gov (United States)

Matías-Guiu, Jordi A; Cabrera-Martín, María Nieves; Cortés-Martínez, Ana; Pytel, Vanesa; Moreno-Ramos, Teresa; Oreja-Guevara, Celia; Carreras, José Luis; Matías-Guiu, Jorge

2017-07-01

Pseudotumoral multiple sclerosis is a rare form of demyelinating disease of the central nervous system. Positron emission tomography (PET) using amyloid-tracers has also been suggested as a marker of damage in white matter lesions in multiple sclerosis due to the nonspecific uptake of these tracers in white matter. We present the case of a 59 year-old woman with a pathological-confirmed pseudotumoral multiple sclerosis, who was studied with the amyloid tracer 18 F-florbetaben. The patient had developed word-finding difficulties and right hemianopia twelve years ago. In that time, MRI showed a lesion on the left hemisphere with an infiltrating aspect in frontotemporal lobes. Brain biopsy showed demyelinating areas and inflammation. During the following years, two new clinical relapses occurred. 18 F-florbetaben PET showed lower uptake in the white matter lesion visualized in the CT and MRI images. Decreased tracer uptake was also observed in a larger area of the left hemisphere beyond the lesions observed on MRI or CT. White matter lesion volume on FLAIR was 44.2mL, and tracer uptake change between damaged white matter and normal appearing white matter was - 40.5%. Standardized uptake value was inferior in the pseudotumoral lesion than in the other white matter lesions. We report the findings of amyloid PET in a patient with pseudotumoral multiple sclerosis. This case provides further evidence on the role of amyloid PET in the assessment of white matter and demyelinating diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantitative PET of liver functions.

Science.gov (United States)

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

2018-01-01

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

Quantitative PET of liver functions

Science.gov (United States)

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

2018-01-01

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

Hyperthyroid dementia: clinicoradiological findings and response to treatment.

Science.gov (United States)

Fukui, T; Hasegawa, Y; Takenaka, H

2001-02-15

Dementia associated with hyperthyroidism is less well documented than is hypothyroid dementia. Therapeutic response of hyperthyroid dementia and associated cerebral circulatory and/or metabolic abnormalities has not been elucidated. We described a patient with hyperthyroid dementia and clinicoradiological response to treatment. Single photon emission computed tomographic (SPECT) study was repeated and analyzed semiquantitatively. A 67-year-old man experienced progressive impairments of attention, memory, constructive skills and behavior as well as hand tremor and weight loss of two-year duration. Laboratory findings were compatible with Graves' disease. The initial SPECT showed diffuse tracer uptake defect with an accentuation in the bilateral temporoparietal regions. Clinical and SPECT findings both suggested concurrent "possible" Alzheimer's disease. However, initial treatment with a beta-blocker improved behavior and attention-related cognitive functions as well as tracer uptake in the frontal lobes. Subsequent treatment with additional methimazole then improved memory and constructive abilities when a euthyroid state was established. Uptake defect in the temporoparietal regions also responded gradually to the medication. We suggest that the present patient represent hyperthyroid dementia, which responds favorably to treatment with regard to clinical symptoms and SPECT findings. We also suggest that thyroid function be measured in patients with "possible" Alzheimer's disease because treatable hyperthyroid dementia may not be identified.

18F PET with flutemetamol for the early diagnosis of Alzheimer's disease dementia and other dementias in people with mild cognitive impairment (MCI).

Science.gov (United States)

Martínez, Gabriel; Vernooij, Robin Wm; Fuentes Padilla, Paulina; Zamora, Javier; Flicker, Leon; Bonfill Cosp, Xavier

2017-11-22

18 F-flutemetamol uptake by brain tissue, measured by positron emission tomography (PET), is accepted by regulatory agencies like the Food and Drug Administration (FDA) and the European Medicine Agencies (EMA) for assessing amyloid load in people with dementia. Its added value is mainly demonstrated by excluding Alzheimer's pathology in an established dementia diagnosis. However, the National Institute on Aging and Alzheimer's Association (NIA-AA) revised the diagnostic criteria for Alzheimer's disease and the confidence in the diagnosis of mild cognitive impairment (MCI) due to Alzheimer's disease may be increased when using some amyloid biomarkers tests like 18 F-flutemetamol. These tests, added to the MCI core clinical criteria, might increase the diagnostic test accuracy (DTA) of a testing strategy. However, the DTA of 18 F-flutemetamol to predict the progression from MCI to Alzheimer's disease dementia (ADD) or other dementias has not yet been systematically evaluated. To determine the DTA of the 18 F-flutemetamol PET scan for detecting people with MCI at time of performing the test who will clinically progress to ADD, other forms of dementia (non-ADD) or any form of dementia at follow-up. The most recent search for this review was performed in May 2017. We searched MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP), BIOSIS Citation Index (Thomson Reuters Web of Science), Web of Science Core Collection, including the Science Citation Index (Thomson Reuters Web of Science) and the Conference Proceedings Citation Index (Thomson Reuters Web of Science), LILACS (BIREME), CINAHL (EBSCOhost), ClinicalTrials.gov (https://clinicaltrials.gov), and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) (http://www.who.int/ictrp/search/en/). We also searched ALOIS, the Cochrane Dementia & Cognitive Improvement Group's specialised register of dementia studies (http://www.medicine.ox.ac.uk/alois/). We checked the reference lists of any

PET/MR in oncology

DEFF Research Database (Denmark)

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

2012-01-01

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

Synthesis and preliminary evaluation of 18F-labeled 4-thia palmitate as a PET tracer of myocardial fatty acid oxidation

International Nuclear Information System (INIS)

DeGrado, Timothy R.; Wang Shuyan; Holden, James E.; Nickles, R. Jerome; Taylor, Michael; Stone, Charles K.

2000-01-01

Interest remains strong for the development of a noninvasive technique for assessment of regional fatty acid oxidation rate in the myocardium. 18 F-labeled 4-thia palmitate (FTP, 16-[ 18 F]fluoro-4-thia-hexadecanoic acid) has been synthesized and preliminarily evaluated as a metabolically trapped probe of myocardial fatty acid oxidation for positron emission tomography (PET). The radiotracer is synthesized by Kryptofix 2.2.2/K 2 CO 3 assisted nucleophilic radiofluorination of an iodo-ester precursor, followed by alkaline hydrolysis and by purification by reverse phase high performance liquid chromatography. Biodistribution studies in rats showed high uptake and long retention of FTP in heart, liver, and kidneys consistent with relatively high fatty acid oxidation rates in these tissues. Inhibition of carnitine palmitoyl-transferase-I caused an 80% reduction in myocardial uptake, suggesting the dependence of trapping on the transport of tracer into the mitochondrion. Experiments with perfused rat hearts showed that the estimates of the fractional metabolic trapping rate (FR) of FTP tracked inhibition of oxidation rate of palmitate with hypoxia, whereas the FR of the 6-thia analog 17-[ 18 F]fluoro-6-thia-heptadecanoic acid was insensitive to hypoxia. In vivo defluorination of FTP in the rat was evidenced by bone uptake of radioactivity. A PET imaging study with FTP in normal swine showed excellent myocardial images, prolonged myocardial retention, and no bone uptake of radioactivity up to 3 h, the last finding suggesting a species dependence for defluorination of the omega-labeled fatty acid. The results support further investigation of FTP as a potential PET tracer for assessing regional fatty acid oxidation rate in the human myocardium

Diagnostic accuracy of 18F amyloid PET tracers for the diagnosis of Alzheimer's disease: a systematic review and meta-analysis

International Nuclear Information System (INIS)

Morris, Elizabeth; Chalkidou, Anastasia; Hammers, Alexander; Peacock, Janet; Summers, Jennifer; Keevil, Stephen

2016-01-01

Imaging or tissue biomarker evidence has been introduced into the core diagnostic pathway for Alzheimer's disease (AD). PET using 18 F-labelled beta-amyloid PET tracers has shown promise for the early diagnosis of AD. However, most studies included only small numbers of participants and no consensus has been reached as to which radiotracer has the highest diagnostic accuracy. First, we performed a systematic review of the literature published between 1990 and 2014 for studies exploring the diagnostic accuracy of florbetaben, florbetapir and flutemetamol in AD. The included studies were analysed using the QUADAS assessment of methodological quality. A meta-analysis of the sensitivity and specificity reported within each study was performed. Pooled values were calculated for each radiotracer and for visual or quantitative analysis by population included. The systematic review identified nine studies eligible for inclusion. There were limited variations in the methods between studies reporting the same radiotracer. The meta-analysis results showed that pooled sensitivity and specificity values were in general high for all tracers. This was confirmed by calculating likelihood ratios. A patient with a positive ratio is much more likely to have AD than a patient with a negative ratio, and vice versa. However, specificity was higher when only patients with AD were compared with healthy controls. This systematic review and meta-analysis found no marked differences in the diagnostic accuracy of the three beta-amyloid radiotracers. All tracers perform better when used to discriminate between patients with AD and healthy controls. The sensitivity and specificity for quantitative and visual analysis are comparable to those of other imaging or biomarker techniques used to diagnose AD. Further research is required to identify the combination of tests that provides the highest sensitivity and specificity, and to identify the most suitable position for the tracer in the

Assessment of dopamine metabolism in brain of patients with dementia by means of 18F-fluorodopa and PET

International Nuclear Information System (INIS)

Itoh, Masatoshi; Fujiwara, Takehiko; Meguro, Kenichi; Hatazawa, Jun; Iwata, Ren; Ishiwata, Kiichi; Takahashi, Toshihiro; Ido, Tatsuo; Sasaki, Hidetada.

1994-01-01

By means of positron emission tomography (PET) and 18 F-fluorodopa (FDOPA), a study was initiated to analyze the cerebral dopamine (DA) metabolism of 32 subjects including those with AD/SDAT and vascular dementia (VD, multi-infarct type). A semiautomated irregular ROI drawing routine to identify the striatum was developed that interactively defined the PET threshold pixels referring to the count histograms and location of the corresponding pixels. A comparative study by five examiners showed significant improvement in the area size definition and count linearity particularly for low contrast objects. The graphical plot was employed to calculate the FDOPA influx rate (Ki) for the ROI data with cerebellar radioactivity as an input function. The striatal Ki value was found to be relatively stable and did not show signs of a significant age-related change. The vascular patients had smaller Ki to the striatum than the aged control. Although the mean Ki of AD/SDAT was almost compatible with that of age-matched normals, their Ki was more scattered with higher and lower Ki cases. The multiple regression analysis revealed that the Ki could be predicted by age and the mini-mental state (MMS) performance (r 2 =0.590, p 2 =0.401, and p<0.05 for VD). MMS was found to be a more dominant factor than age. We conclude that dopamine metabolism became disturbed as dementia became progressively severe. (author)

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....

Bringing Physiology into PET of the Liver

OpenAIRE

Keiding, Susanne

2012-01-01

Several physiologic features make interpretation of PET studies of liver physiology an exciting challenge. As with other organs, hepatic tracer kinetics using PET is quantified by dynamic recording of the liver after the administration of a radioactive tracer, with measurements of time–activity curves in the blood supply. However, the liver receives blood from both the portal vein and the hepatic artery, with the peak of the portal vein time–activity curve being delayed and dispersed compared...

Cross-validation of biomarkers for the early differential diagnosis and prognosis of dementia in a clinical setting

International Nuclear Information System (INIS)

Perani, Daniela; Cerami, Chiara; Caminiti, Silvia Paola; Santangelo, Roberto; Coppi, Elisabetta; Ferrari, Laura; Magnani, Giuseppe; Pinto, Patrizia; Passerini, Gabriella; Falini, Andrea; Iannaccone, Sandro; Cappa, Stefano Francesco; Comi, Giancarlo; Gianolli, Luigi

2016-01-01

The aim of this study was to evaluate the supportive role of molecular and structural biomarkers (CSF protein levels, FDG PET and MRI) in the early differential diagnosis of dementia in a large sample of patients with neurodegenerative dementia, and in determining the risk of disease progression in subjects with mild cognitive impairment (MCI). We evaluated the supportive role of CSF Aβ 42 , t-Tau, p-Tau levels, conventional brain MRI and visual assessment of FDG PET SPM t-maps in the early diagnosis of dementia and the evaluation of MCI progression. Diagnosis based on molecular biomarkers showed the best fit with the final diagnosis at a long follow-up. FDG PET SPM t-maps had the highest diagnostic accuracy in Alzheimer's disease and in the differential diagnosis of non-Alzheimer's disease dementias. The p-tau/Aβ 42 ratio was the only CSF biomarker providing a significant classification rate for Alzheimer's disease. An Alzheimer's disease-positive metabolic pattern as shown by FDG PET SPM in MCI was the best predictor of conversion to Alzheimer's disease. In this clinical setting, FDG PET SPM t-maps and the p-tau/Aβ 42 ratio improved clinical diagnostic accuracy, supporting the importance of these biomarkers in the emerging diagnostic criteria for Alzheimer's disease dementia. FDG PET using SPM t-maps had the highest predictive value by identifying hypometabolic patterns in different neurodegenerative dementias and normal brain metabolism in MCI, confirming its additional crucial exclusionary role. (orig.)

Cross-validation of biomarkers for the early differential diagnosis and prognosis of dementia in a clinical setting

Energy Technology Data Exchange (ETDEWEB)

Perani, Daniela [Vita-Salute San Raffaele University, Milan (Italy); San Raffaele Scientific Institute, Division of Neuroscience, Milan (Italy); San Raffaele Hospital, Nuclear Medicine Unit, Milan (Italy); Cerami, Chiara [Vita-Salute San Raffaele University, Milan (Italy); San Raffaele Scientific Institute, Division of Neuroscience, Milan (Italy); San Raffaele Hospital, Clinical Neuroscience Department, Milan (Italy); Caminiti, Silvia Paola [Vita-Salute San Raffaele University, Milan (Italy); San Raffaele Scientific Institute, Division of Neuroscience, Milan (Italy); Santangelo, Roberto; Coppi, Elisabetta; Ferrari, Laura; Magnani, Giuseppe [San Raffaele Hospital, Department of Neurology, Milan (Italy); Pinto, Patrizia [Papa Giovanni XXIII Hospital, Department of Neurology, Bergamo (Italy); Passerini, Gabriella [Servizio di Medicina di Laboratorio OSR, Milan (Italy); Falini, Andrea [Vita-Salute San Raffaele University, Milan (Italy); San Raffaele Scientific Institute, Division of Neuroscience, Milan (Italy); San Raffaele Hospital, CERMAC - Department of Neuroradiology, Milan (Italy); Iannaccone, Sandro [San Raffaele Hospital, Clinical Neuroscience Department, Milan (Italy); Cappa, Stefano Francesco [San Raffaele Scientific Institute, Division of Neuroscience, Milan (Italy); IUSS Pavia, Pavia (Italy); Comi, Giancarlo [Vita-Salute San Raffaele University, Milan (Italy); San Raffaele Hospital, Department of Neurology, Milan (Italy); Gianolli, Luigi [San Raffaele Hospital, Nuclear Medicine Unit, Milan (Italy)

2016-03-15

The aim of this study was to evaluate the supportive role of molecular and structural biomarkers (CSF protein levels, FDG PET and MRI) in the early differential diagnosis of dementia in a large sample of patients with neurodegenerative dementia, and in determining the risk of disease progression in subjects with mild cognitive impairment (MCI). We evaluated the supportive role of CSF Aβ{sub 42}, t-Tau, p-Tau levels, conventional brain MRI and visual assessment of FDG PET SPM t-maps in the early diagnosis of dementia and the evaluation of MCI progression. Diagnosis based on molecular biomarkers showed the best fit with the final diagnosis at a long follow-up. FDG PET SPM t-maps had the highest diagnostic accuracy in Alzheimer's disease and in the differential diagnosis of non-Alzheimer's disease dementias. The p-tau/Aβ{sub 42} ratio was the only CSF biomarker providing a significant classification rate for Alzheimer's disease. An Alzheimer's disease-positive metabolic pattern as shown by FDG PET SPM in MCI was the best predictor of conversion to Alzheimer's disease. In this clinical setting, FDG PET SPM t-maps and the p-tau/Aβ{sub 42} ratio improved clinical diagnostic accuracy, supporting the importance of these biomarkers in the emerging diagnostic criteria for Alzheimer's disease dementia. FDG PET using SPM t-maps had the highest predictive value by identifying hypometabolic patterns in different neurodegenerative dementias and normal brain metabolism in MCI, confirming its additional crucial exclusionary role. (orig.)

The preliminary study of 18F-FDG PET in diagnosis of Alzheimer's disease

International Nuclear Information System (INIS)

Ma, Y.; Zhang, X.; Le, D.

2000-01-01

To investigate the imaging characteristic and diagnostic criteria of 18F-FDG brain PET in detecting Alzheimer's disease (AD). The study included in 12 normal subject, 12 patients with AD, 6 patients with vascular dementia, 3 patients with Lewy body disease (LBD) and 2 patients with mixed dementia. The dementia severity was measured by ESD and MMSE. 12 cases had mild, 7 moderate and 4 severe dementia. 23 patients and 6 normal subjects underwent MR imaging of the brain. All participants fasted for at least 6 hours. 40 minutes after intravenous administration of 185-370 MBq 18F-FDG, 2D brain scan in 25 cases and 3D scan in 10 cases were performed using SIEMENS ECAT 47 scanner. The transaxial, coronal and sagittal images were then reconstructed by computer. At the same time, semiquantitative analysis was also applied to help evaluation using the ratio of mean radioactivity between cerebral lobe to cerebellum (Rcl/cb). In normal subjects PET scan showed clear images of cerebral cortex, basal ganglia, thalamus and cerebellum with symmetrical distribution of radioactivity. 22 of 23 patients were found to have decreased uptake of FDG in the brain. 20 patients had cerebral atrophy and it also appeared in 6 normal elder people. PET images for Alzheimer's disease were classified in 6 normal elder people. PET image for Alzheimer's 3 patterns: bilateral parietal hypo metabolism in 5 cases, bilateral temporo-parietal hypo metabolism in 4 cases and unilateral temporo-parietal hypo metabolism in 3 cases. The Rcl/cb of AD patents in parietal and temporal was significantly decreased than normal subjects (p<0.05). PET images for non-AD dementia were also classified 3 patterns: multiple and asymmetrical patch foci with decreased radioactivity in 8 cases, bilateral temporo-parietal with diffuse cortical hypo metabolism in 2 cases, and normal imaging in 1 case. The hypo metabolic involvement was accorded with severity of dementia. The more dementia had, the bigger hypometabloic region

Systematic screening of imaging biomarkers for the Islets of Langerhans, among clinically available positron emission tomography tracers

International Nuclear Information System (INIS)

Karlsson, Filip; Antonodimitrakis, Pantelis Clewemar; Eriksson, Olof

2015-01-01

Introduction: Functional imaging could be utilized for visualizing pancreatic islets of Langerhans. Therefore, we present a stepwise algorithm for screening of clinically available positron emission tomography (PET) tracers for their use in imaging of the neuroendocrine pancreas in the context of diabetes. Methods: A stepwise procedure was developed for screening potential islet imaging agents. Suitable PET-tracer candidates were identified by their molecular mechanism of targeting. Clinical abdominal examinations were retrospectively analyzed for pancreatic uptake and retention. The target protein localization in the pancreas was assessed in silico by –omics approaches and the in vitro by binding assays to human pancreatic tissue. Results: Six putative candidates were identified and screened by using the stepwise procedure. Among the tested PET tracers, only [ 11 C]5-Hydroxy-tryptophan passed all steps. The remaining identified candidates were falsified as candidates and discarded following in silico and in vitro screening. Conclusions: Of the six clinically available PET tracers identified, [ 11 C]5-HTP was found to be a promising candidate for beta cell imaging, based on intensity of in vivo pancreatic uptake in humans, and islet specificity as assessed on human pancreatic cell preparations. The flow scheme described herein constitutes a methodology for evaluating putative islet imaging biomarkers among clinically available PET tracers

Positron emission tomography (PET) in psychiatry. PET in der Psychiatrie

Energy Technology Data Exchange (ETDEWEB)

Herholz, K [Max-Planck-Institut fuer Neurologische Forschung und Neurologische Klinik der Universitaet Koeln (Germany)

1993-08-13

Currently, clinical PET is mainly useful in psychiatry and related areas for differential diagnosis of dementia. In dementia of Alzheimer type reductions of glucose metabolism are found mainly in the temporoparietal assocaiton cortex, in Pick's disease mainly in the frontal cortex, and in Huntington's disease in the striatum. Other demential diseases usually show less toposelective metabolic impairment. In the future, new diagnostic possibilities may arise from analysis of functional stimulation of specific brain areas and from the use of ligands for specific neurotransmitter systems. (orig.)

Automatic extraction of forward stroke volume using dynamic PET/CT

DEFF Research Database (Denmark)

Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik

Background: Dynamic PET can be used to extract forward stroke volume (FSV) by the indicator dilution principle. The technique employed can be automated and is in theory independent on the tracer used and may therefore be added to any dynamic cardiac PET protocol. The aim of this study...... was to validate automated methods for extracting FSV directly from dynamic PET studies for two different tracers and to examine potential scanner hardware bias. Methods: 21 subjects underwent a dynamic 27 min 11C-acetate PET scan on a Siemens Biograph TruePoint 64 PET/CT scanner (scanner I). In addition, 8...... subjects underwent a dynamic 6 min 15O-water PET scan followed by a 27 min 11C-acetate PET scan on a GE Discovery ST PET/CT scanner (scanner II). The LV-aortic time-activity curve (TAC) was extracted automatically from dynamic PET data using cluster analysis. The first-pass peak was isolated by automatic...

Diagnostic accuracy of {sup 18}F amyloid PET tracers for the diagnosis of Alzheimer's disease: a systematic review and meta-analysis

Energy Technology Data Exchange (ETDEWEB)

Morris, Elizabeth; Chalkidou, Anastasia [St Thomas' Hospital, King' s Technology Evaluation Centre, King' s College London, London (United Kingdom); St Thomas' Hospital, Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King' s College London, London (United Kingdom); Hammers, Alexander [St Thomas' Hospital, Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King' s College London, London (United Kingdom); Peacock, Janet; Summers, Jennifer [St Thomas' Hospital, King' s Technology Evaluation Centre, King' s College London, London (United Kingdom); King' s College London, Division of Health and Social Care Research, London (United Kingdom); King' s College London, NIHR Biomedical Research Centre at Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom); Keevil, Stephen [St Thomas' Hospital, King' s Technology Evaluation Centre, King' s College London, London (United Kingdom); St Thomas' Hospital, Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King' s College London, London (United Kingdom); St Thomas' Hospital, Department of Medical Physics, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom)

2016-02-15

Imaging or tissue biomarker evidence has been introduced into the core diagnostic pathway for Alzheimer's disease (AD). PET using {sup 18}F-labelled beta-amyloid PET tracers has shown promise for the early diagnosis of AD. However, most studies included only small numbers of participants and no consensus has been reached as to which radiotracer has the highest diagnostic accuracy. First, we performed a systematic review of the literature published between 1990 and 2014 for studies exploring the diagnostic accuracy of florbetaben, florbetapir and flutemetamol in AD. The included studies were analysed using the QUADAS assessment of methodological quality. A meta-analysis of the sensitivity and specificity reported within each study was performed. Pooled values were calculated for each radiotracer and for visual or quantitative analysis by population included. The systematic review identified nine studies eligible for inclusion. There were limited variations in the methods between studies reporting the same radiotracer. The meta-analysis results showed that pooled sensitivity and specificity values were in general high for all tracers. This was confirmed by calculating likelihood ratios. A patient with a positive ratio is much more likely to have AD than a patient with a negative ratio, and vice versa. However, specificity was higher when only patients with AD were compared with healthy controls. This systematic review and meta-analysis found no marked differences in the diagnostic accuracy of the three beta-amyloid radiotracers. All tracers perform better when used to discriminate between patients with AD and healthy controls. The sensitivity and specificity for quantitative and visual analysis are comparable to those of other imaging or biomarker techniques used to diagnose AD. Further research is required to identify the combination of tests that provides the highest sensitivity and specificity, and to identify the most suitable position for the tracer in the

Synthesis and preliminary evaluation of {sup 18}F-labeled 4-thia palmitate as a PET tracer of myocardial fatty acid oxidation

Energy Technology Data Exchange (ETDEWEB)

DeGrado, Timothy R. E-mail: trd@petsparc.mc.duke.edu; Wang Shuyan; Holden, James E.; Nickles, R. Jerome; Taylor, Michael; Stone, Charles K

2000-04-01

Interest remains strong for the development of a noninvasive technique for assessment of regional fatty acid oxidation rate in the myocardium. {sup 18}F-labeled 4-thia palmitate (FTP, 16-[{sup 18}F]fluoro-4-thia-hexadecanoic acid) has been synthesized and preliminarily evaluated as a metabolically trapped probe of myocardial fatty acid oxidation for positron emission tomography (PET). The radiotracer is synthesized by Kryptofix 2.2.2/K{sub 2}CO{sub 3} assisted nucleophilic radiofluorination of an iodo-ester precursor, followed by alkaline hydrolysis and by purification by reverse phase high performance liquid chromatography. Biodistribution studies in rats showed high uptake and long retention of FTP in heart, liver, and kidneys consistent with relatively high fatty acid oxidation rates in these tissues. Inhibition of carnitine palmitoyl-transferase-I caused an 80% reduction in myocardial uptake, suggesting the dependence of trapping on the transport of tracer into the mitochondrion. Experiments with perfused rat hearts showed that the estimates of the fractional metabolic trapping rate (FR) of FTP tracked inhibition of oxidation rate of palmitate with hypoxia, whereas the FR of the 6-thia analog 17-[{sup 18}F]fluoro-6-thia-heptadecanoic acid was insensitive to hypoxia. In vivo defluorination of FTP in the rat was evidenced by bone uptake of radioactivity. A PET imaging study with FTP in normal swine showed excellent myocardial images, prolonged myocardial retention, and no bone uptake of radioactivity up to 3 h, the last finding suggesting a species dependence for defluorination of the omega-labeled fatty acid. The results support further investigation of FTP as a potential PET tracer for assessing regional fatty acid oxidation rate in the human myocardium.

PET applications in pediatrics

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-01

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

VII. Boettstein Colloquium: PET-Radiopharmaceuticals at PSI: achievement and future prospects

International Nuclear Information System (INIS)

Schubiger, P.A.; Beer, H.F.; Blaeuenstein, P.; Leenders, K.E.

1993-01-01

The three sessions of the 1993 Boettstein colloquium dealt with the following topics: - PET-radiopharmaceuticals, - PET-scanning: significance of tracer uptake, - clinical options using PET. 22 papers were presented. figs., refs

VII. Boettstein Colloquium: PET-Radiopharmaceuticals at PSI: achievement and future prospects

Energy Technology Data Exchange (ETDEWEB)

Schubiger, P.A.; Beer, H.F.; Blaeuenstein, P.; Leenders, K.E.

1993-12-31

The three sessions of the 1993 Boettstein colloquium dealt with the following topics: - PET-radiopharmaceuticals, - PET-scanning: significance of tracer uptake, - clinical options using PET. 22 papers were presented. figs., refs.

VII. Boettstein Colloquium: PET-Radiopharmaceuticals at PSI: achievement and future prospects

Energy Technology Data Exchange (ETDEWEB)

Schubiger, P A; Beer, H F; Blaeuenstein, P; Leenders, K E

1994-12-31

The three sessions of the 1993 Boettstein colloquium dealt with the following topics: - PET-radiopharmaceuticals, - PET-scanning: significance of tracer uptake, - clinical options using PET. 22 papers were presented. figs., refs.

Re(CO)3([18F]FEDA), a novel 18F PET renal tracer: Radiosynthesis and preclinical evaluation.

Science.gov (United States)

Lipowska, Malgorzata; Jarkas, Nashwa; Voll, Ronald J; Nye, Jonathon A; Klenc, Jeffrey; Goodman, Mark M; Taylor, Andrew T

2018-03-01

Our previous work demonstrated that the 99m Tc renal tracer, 99m Tc(CO) 3 (FEDA) ( 99m Tc-1), has a rapid clearance comparable in rats to that of 131 I-OIH, the radioactive gold standard for the measurement of effective renal plasma flow. The uncharged fluoroethyl pendant group of 99m Tc-1 provides a route to the synthesis of a structurally analogous rhenium-tricarbonyl 18 F renal imaging agent, Re(CO) 3 ([ 18 F]FEDA) ( 18 F-1). Our goal was to develop an efficient one-step method for the preparation of 18 F-1 and to compare its pharmacokinetic properties with those of 131 I-OIH in rats. 18 F-1 was prepared by the nucleophilic 18 F-fluorination of its tosyl precursor. The labeled compound was isolated by HPLC and subsequently evaluated in Sprague-Dawley rats using 131 I-OIH as an internal control and by dynamic PET/CT imaging. Plasma protein binding (PPB) and erythrocyte uptake (RCB) were determined and the urine was analyzed for metabolites. 18 F-1 was efficiently prepared as a single species with high radiochemical purity (>99%) and it displayed high radiochemical stability in vitro and in vivo. PPB was 87% and RCB was 21%. Biodistribution studies confirmed rapid renal extraction and high specificity for renal excretion, comparable to that of 131 I-OIH, with minimal hepatic/gastrointestinal elimination. The activity in the urine, as a percentage of 131 I-OIH, was 92% and 95% at 10 and 60 min, respectively. All other organs (heart, spleen, lungs) showed a negligible tracer uptake (F-1 through the kidneys and into the bladder; there was no demonstrable activity in bone verifying the absence of free [ 18 F]fluoride. 18 F-1 exhibited a high specificity for the kidney, rapid renal excretion comparable to that of 131 I-OIH and high in vivo radiochemical stability. Not only is 18 F-1 a promising PET renal tracer, but it provides a route to the development of a pair of analogous 18 F/ 99m Tc renal imaging agents with almost identical structures and comparable

Positron emission tomography (PET) in psychiatry. PET in der Psychiatrie

Energy Technology Data Exchange (ETDEWEB)

Herholz, K. (Max-Planck-Institut fuer Neurologische Forschung und Neurologische Klinik der Universitaet Koeln (Germany))

1993-08-13

Currently, clinical PET is mainly useful in psychiatry and related areas for differential diagnosis of dementia. In dementia of Alzheimer type reductions of glucose metabolism are found mainly in the temporoparietal assocaiton cortex, in Pick's disease mainly in the frontal cortex, and in Huntington's disease in the striatum. Other demential diseases usually show less toposelective metabolic impairment. In the future, new diagnostic possibilities may arise from analysis of functional stimulation of specific brain areas and from the use of ligands for specific neurotransmitter systems. (orig.)

{sup 68}Ga-PSMA-11 PET/CT in primary staging of prostate cancer: PSA and Gleason score predict the intensity of tracer accumulation in the primary tumour

Energy Technology Data Exchange (ETDEWEB)

Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Guggenberg, Elisabeth von; Kendler, Dorota; Scarpa, Lorenza; Di Santo, Gianpaolo; Roig, Llanos Geraldo; Maffey-Steffan, Johanna; Virgolini, Irene Johanna [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Fritz, Josef [Medical University Innsbruck, Department of Medical Statistics, Informatics and Health Economics, Innsbruck (Austria); Horninger, Wolfgang [Medical University Innsbruck, Department of Urology, Innsbruck (Austria)

2017-06-15

Prostate cancer (PC) cells typically show increased expression of prostate-specific membrane antigen (PSMA), which can be visualized by {sup 68}Ga-PSMA-11 PET/CT. The aim of this study was to assess the intensity of {sup 68}Ga-PSMA-11 uptake in the primary tumour and metastases in patients with biopsy-proven PC prior to therapy, and to determine whether a correlation exists between the primary tumour-related {sup 68}Ga-PSMA-11 accumulation and the Gleason score (GS) or prostate-specific antigen (PSA) level. Ninety patients with transrectal ultrasound biopsy-proven PC (GS 6-10; median PSA: 9.7 ng/ml) referred for {sup 68}Ga-PSMA-11 PET/CT were retrospectively analysed. PET images were analysed visually and semiquantitatively by measuring the maximum standardized uptake value (SUV{sub max}). The SUV{sub max} of the primary tumour and pathologic lesions suspicious for lymphatic or distant metastases were then compared to the physiologic background activity of normal prostate tissue and gluteal muscle. The SUV{sub max} of the primary tumour was assessed in relation to both PSA level and GS. Eighty-two patients (91.1%) demonstrated pathologic tracer accumulation in the primary tumour that exceeded physiologic tracer uptake in normal prostate tissue (median SUV{sub max}: 12.5 vs. 3.9). Tumours with GS of 6, 7a (3+4) and 7b (4+3) showed significantly lower {sup 68}Ga-PSMA-11 uptake, with median SUV{sub max} of 5.9, 8.3 and 8.2, respectively, compared to patients with GS >7 (median SUV{sub max}: 21.2; p < 0.001). PC patients with PSA ≥10.0 ng/ml exhibited significantly higher uptake than those with PSA levels <10.0 ng/ml (median SUV{sub max}: 17.6 versus 7.7; p < 0.001). In 24 patients (26.7%), 82 lymph nodes with pathologic tracer accumulation consistent with metastases were detected (median SUV{sub max}: 10.6). Eleven patients (12.2%) revealed 55 pathologic osseous lesions suspicious for bone metastases (median SUV{sub max}: 11.6). The GS and PSA level correlated with

[18F]FE@SNAP—A new PET tracer for the melanin concentrating hormone receptor 1 (MCHR1): Microfluidic and vessel-based approaches

Science.gov (United States)

Philippe, Cécile; Ungersboeck, Johanna; Schirmer, Eva; Zdravkovic, Milica; Nics, Lukas; Zeilinger, Markus; Shanab, Karem; Lanzenberger, Rupert; Karanikas, Georgios; Spreitzer, Helmut; Viernstein, Helmut; Mitterhauser, Markus; Wadsak, Wolfgang

2012-01-01

Changes in the expression of the melanin concentrating hormone receptor 1 (MCHR1) are involved in a variety of pathologies, especially obesity and anxiety disorders. To monitor these pathologies in-vivo positron emission tomography (PET) is a suitable method. After the successful radiosynthesis of [11C]SNAP-7941—the first PET-Tracer for the MCHR1, we aimed to synthesize its [18F]fluoroethylated analogue: [18F]FE@SNAP. Therefore, microfluidic and vessel-based approaches were tested. [18F]fluoroethylation was conducted via various [18F]fluoroalkylated synthons and direct [18F]fluorination. Only the direct [18F]fluorination of a tosylated precursor using a flow-through microreactor was successful, affording [18F]FE@SNAP in 44.3 ± 2.6%. PMID:22921745

Positron emission tomography (PET) for oncologic applications in oral region

International Nuclear Information System (INIS)

Shozushima, Masanori; Terasaki, Kazunori

2004-01-01

A rapidly emerging clinical application of positron emission tomography (PET) is the detection of cancer with radionuclide tracer, because it provides information unavailable by ultrasound, computed tomography or magnetic resonance imaging. The most commonly used radiotracer for PET oncologic imaging is fluorine-18-labeled fluorodeoxyglucose ( 18 F-FDG). Early studies show PET has potential value in viewing the region of the tumor, detecting, staging, grading, monitoring response to anticancer therapy, and differentiating recurrent or residual disease from post treatment changes. However, limitations of FDG-PET in the head and neck region, namely, physiological FDG uptake in the salivary glands and palatine tonsils, have been reported, increasing the false-positive rates in image interpretation. This review was designed to address these distinctions of oral cancer PET imaging: specialization of PET equipment, cancer cell metabolism, proliferation and tracers, clinical diagnosis of oral cancer with PET, pitfalls in oncologic diagnosis with FDG-PET imaging. (author)

Added value of 18F-florbetaben amyloid PET in the diagnostic workup of most complex patients with dementia in France: A naturalistic study.

Science.gov (United States)

Ceccaldi, Mathieu; Jonveaux, Thérèse; Verger, Antoine; Krolak-Salmon, Pierre; Houzard, Claire; Godefroy, Olivier; Shields, Trevor; Perrotin, Audrey; Gismondi, Rossella; Bullich, Santiago; Jovalekic, Aleksandar; Raffa, Nicola; Pasquier, Florence; Semah, Franck; Dubois, Bruno; Habert, Marie-Odile; Wallon, David; Chastan, Mathieu; Payoux, Pierre; Stephens, Andrew; Guedj, Eric

2018-03-01

Although some studies have previously addressed the clinical impact of amyloid positron emission tomography (PET), none has specifically addressed its selective and hierarchical implementation in relation to cerebrospinal fluid analysis in a naturalistic setting. This multicenter study was performed at French tertiary memory clinics in patients presenting with most complex clinical situations (i.e., early-onset, atypical clinical profiles, suspected mixed etiological conditions, unexpected rate of progression), for whom cerebrospinal fluid analysis was indicated but either not feasible or considered as noncontributory (ClinicalTrials.gov: NCT02681172). Two hundred five patients were enrolled with evaluable florbetaben PET scans; 64.4% of scans were amyloid positive. PET results led to changed diagnosis and improved confidence in 66.8% and 81.5% of patients, respectively, and altered management in 80.0% of cases. High-level improvement of diagnostic certainty and management is provided by selective and hierarchical implementation of florbetaben PET into current standard practices for the most complex dementia cases. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of regularisation priors on dynamic PET Data

International Nuclear Information System (INIS)

Caldeira, Liliana; Scheins, Juergen; Silva, Nuno da; Gaens, Michaela; Shah, N Jon

2014-01-01

Dynamic PET provides temporal information about tracer uptake. However, each PET frame has usually low statistics, resulting in noisy images. The goal is to study effects of prior regularisation on dynamic PET data. Quantification and noise in image-domain and time-domain as well as impact on parametric images is assessed.

Imaging with 124I in differentiated thyroid carcinoma: is PET/MRI superior to PET/CT?

International Nuclear Information System (INIS)

Binse, I.; Poeppel, T.D.; Ruhlmann, M.; Gomez, B.; Bockisch, A.; Rosenbaum-Krumme, S.J.; Umutlu, L.

2016-01-01

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 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 2 ) followed by PET/MRI of the neck 24 h after 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 2 acquisition time (2 min, PET/MRI 2 ) and the other covering the whole MRI scan time (30 min, PET/MRI 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 2 detected significantly more iodine-positive metastases and thyroid remnants than PET/CT 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 30 tended to detect more PET-positive metastases than PET/MRI 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-positive lesions as either metastasis or thyroid remnant

[{sup 18}F]FE rate at SUPPY: a suitable PET tracer for the adenosine A3 receptor? An in vivo study in rodents

Energy Technology Data Exchange (ETDEWEB)

Haeusler, Daniela; Zeilinger, Markus; Wadsak, Wolfgang; Hacker, Marcus; Mitterhauser, Markus [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); Kuntner, Claudia; Wanek, Thomas; Langer, Oliver [AIT Austrian Institute of Technology GmbH, Biomedical Systems, Health and Environment Department, Seibersdorf (Austria); Nics, Lukas [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); University of Vienna, Department of Nutritional Sciences, Vienna (Austria); Savli, Markus; Lanzenberger, Rupert R. [Medical University of Vienna, Department of Psychiatry and Psychotherapy, Vienna (Austria); Karagiannis, Panagiotis [King' s College London, Cutaneous Medicine and Immunotherapy, St. John' s Institute of Dermatology, Division of Genetics and Molecular Medicine King' s College London School of Medicine, Guy' s Hospital, London (United Kingdom); Shanab, Karem; Spreitzer, Helmut [University of Vienna, Department of Drug and Natural Product Synthesis, Vienna (Austria)

2015-04-01

The adenosine A{sub 3} receptor (A3R) is involved in cardiovascular, neurological and tumour-related pathologies and serves as an exceptional pharmaceutical target in the clinical setting. A3R antagonists are considered antiinflammatory, antiallergic and anticancer agents, and to have potential for the treatment of asthma, COPD, glaucoma and stroke. Hence, an appropriate A3R PET tracer would be highly beneficial for the diagnosis and therapy monitoring of these diseases. Therefore, in this preclinical in vivo study we evaluated the potential as a PET tracer of the A3R antagonist [{sup 18}F]FE rate at SUPPY. Rats were injected with [{sup 18}F]FE rate at SUPPY for baseline scans and blocking scans (A3R with MRS1523 or FE rate at SUPPY, P-gp with tariquidar; three animals each). Additionally, metabolism was studied in plasma and brain. In a preliminary experiment in a mouse xenograft model (mice injected with cells expressing the human A3R; three animals), the animals received [{sup 18}F]FE rate at SUPPY and [{sup 18}F]FDG. Dynamic PET imaging was performed (60 min in rats, 90 min in xenografted mice). In vitro stability of [{sup 18}F]FE rate at SUPPY in human and rat plasma was also evaluated. [{sup 18}F]FE rate at SUPPY showed high uptake in fat-rich regions and low uptake in the brain. Pretreatment with MRS1523 led to a decrease in [{sup 18}F]FE rate at SUPPY uptake (p = 0.03), and pretreatment with the P-gp inhibitor tariquidar led to a 1.24-fold increase in [{sup 18}F]FE rate at SUPPY uptake (p = 0.09) in rat brain. There was no significant difference in metabolites in plasma and brain in the treatment groups. However, plasma concentrations of [{sup 18}F]FE rate at SUPPY were reduced to levels similar to those in rat brain after blocking. In contrast to [{sup 18}F]FDG uptake (p = 0.12), the xenograft model showed significantly increased uptake of [{sup 18}F]FE rate at SUPPY in the tissue masses from CHO cells expressing the human A3R (p = 0.03). [{sup 18}F

Radiosynthesis and biological evaluation of N-(2-[18F]fluoropropionyl)-3,4-dihydroxy-l-phenylalanine as a PET tracer for oncologic imaging.

Science.gov (United States)

Tang, Caihua; Nie, Dahong; Tang, Ganghua; Gao, Siyuan; Liu, Shaoyu; Wen, Fuhua; Tang, Xiaolan

2017-07-01

Several 11 C and 18 F labeled 3,4-dihydroxy-l-phenylalanine (l-DOPA) analogues have been used for neurologic and oncologic diseases, especially for brain tumors and neuroendocrine tumors PET imaging. However, 18 F-labeled N-substituted l-DOPA analogues have not been reported so far. In the current study, radiosynthesis and biological evaluation of a new 18 F-labeled l-DOPA analogue, N-(2-[ 18 F]fluoropropionyl)-3,4-dihydroxy-l-phenylalanine ([ 18 F]FPDOPA) for tumor PET imaging are performed. The synthesis of [ 18 F]FPDOPA was via a two-step reaction sequence from 4-nitrophenyl-2-[ 18 F]fluoropropionate ([ 18 F]NFP). The biodistribution of [ 18 F]FPDOPA was determined in normal Kunming mice. In vitro competitive inhibition and protein incorporation experiments were performed with SPC-A-1 lung adenocarcinoma cell lines. PET/CT studies of [ 18 F]FPDOPA were conducted in C6 rat glioma and SPC-A-1 human lung adenocarcinoma and H460 human large cell lung cancer-bearing nude mice. [ 18 F]FPDOPA was prepared with a decay-corrected radiochemical yield of 28±5% and a specific activity of 50±15GBq/μmol (n=10) within 125min. In vitro cell experiments showed that [ 18 F]FPDOPA uptake in SPC-A-1 cells was primarily transported through Na + -independent system L, with Na + -dependent system B 0,+ and system ASC partly involved in it. Biodistribution data in mice showed that renal-bladder route was the main excretory system of [ 18 F]FPDOPA. PET imaging demonstrated intense accumulation of [ 18 F]FPDOPA in several tumor xenografts, with (8.50±0.40)%ID/g in C6 glioma, (6.30±0.12)%ID/g in SPC-A-1 lung adenocarcinoma, and (6.50±0.10)%ID/g in H460 large cell lung cancer, respectively. A novel N-substituted 18 F-labeled L-DOPA analogue [ 18 F]FPDOPA is synthesized and evaluated in vitro and in vivo. The results support that [ 18 F]FPDOPA seems to be a potential PET tracer for tumor imaging, especially be a better potential PET tracer than [ 18 F]fluoro-2-deoxy-d-glucose ([ 18 F

18F-FDG PET-CT pattern in idiopathic normal pressure hydrocephalus

Directory of Open Access Journals (Sweden)

Ryan A. Townley

Full Text Available Background: Idiopathic normal pressure hydrocephalus (iNPH is an important and treatable cause of neurologic impairment. Diagnosis is complicated due to symptoms overlapping with other age related disorders. The pathophysiology underlying iNPH is not well understood. We explored FDG-PET abnormalities in iNPH patients in order to determine if FDG-PET may serve as a biomarker to differentiate iNPH from common neurodegenerative disorders. Methods: We retrospectively compared 18F-FDG PET-CT imaging patterns from seven iNPH patients (mean age 74 ± 6 years to age and sex matched controls, as well as patients diagnosed with clinical Alzheimer's disease dementia (AD, Dementia with Lewy Bodies (DLB and Parkinson's Disease Dementia (PDD, and behavioral variant frontotemporal dementia (bvFTD. Partial volume corrected and uncorrected images were reviewed separately. Results: Patients with iNPH, when compared to controls, AD, DLB/PDD, and bvFTD, had significant regional hypometabolism in the dorsal striatum, involving the caudate and putamen bilaterally. These results remained highly significant after partial volume correction. Conclusions: In this study, we report a FDG-PET pattern of hypometabolism in iNPH involving the caudate and putamen with preserved cortical metabolism. This pattern may differentiate iNPH from degenerative diseases and has the potential to serve as a biomarker for iNPH in future studies. These findings also further our understanding of the pathophysiology underlying the iNPH clinical presentation. Keywords: FDG-PET, Normal pressure hydrocephalus, Hypometabolism, Caudate, Biomarker

Initial evaluation of a practical PET respiratory motion correction method in clinical simultaneous PET/MRI

International Nuclear Information System (INIS)

Manber, Richard; Thielemans, Kris; Hutton, Brian; Barnes, Anna; Ourselin, Sebastien; Arridge, Simon; O’Meara, Celia; Atkinson, David

2014-01-01

Respiratory motion during PET acquisitions can cause image artefacts, with sharpness and tracer quantification adversely affected due to count ‘smearing’. Motion correction by registration of PET gates becomes increasingly difficult with shorter scan times and less counts. The advent of simultaneous PET/MRI scanners allows the use of high spatial resolution MRI to capture motion states during respiration [1, 2]. In this work, we use a respiratory signal derived from the PET list-mode data [3, ], with no requirement for an external device or MR sequence modifications.

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

Neuroimaging in dementia and Alzheimer's disease: Current protocols and practice in the Republic of Ireland

International Nuclear Information System (INIS)

Kelly, I.; Butler, M.-L.; Ciblis, A.; McNulty, J.P.

2016-01-01

Introduction: Neuroimaging plays an essential supportive role in the diagnosis of dementia, assisting in establishing the dementia subtype(s). This has significant value in both treatment and care decisions and has important implications for prognosis. This study aims to explore the development and nature of neuroimaging protocols currently used in the assessment of dementia and Alzheimer's disease (AD). Methods: An online questionnaire was designed and distributed to lead radiography personnel working in computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) departments (n = 94) in both hospital-based and out-patient imaging centres in the Republic of Ireland. Results: Response rates for each modality ranged from 42 to 44%. CT, MRI, and PET were used to specifically diagnose dementia or AD by 43%, 40% and 50% of responding centres respectively. Of these, dementia-specific neuroimaging protocols were utilised in 33%, 50% and 100% of CT, MRI and PET centres respectively, with the remainder using either standard or other non-specific protocols. Both radiologists and clinical specialist radiographers participated in the development of the majority of protocols. The Royal College of Radiologists (RCR) guidelines were most commonly referenced as informing protocol development, however, none of the MRI respondents were able to identify any guidelines used to inform MR protocol development. Conclusion: Currently there is no consensus in Ireland on optimal dementia/AD neuroimaging protocols, particularly for PET and MRI. Similarly the use of validated and published guidelines to inform protocols is not universal. - Highlights: • We examined the nature of neuroimaging protocols for dementia and Alzheimer's disease in Ireland. • Dementia or Alzheimer's disease-specific protocols were used by between 33 and 100% of centres depending on modality. • Stated dementia-specific protocols were identical for CT whereas

Clinical usefulness of PET in the management of oral cancer. Comparison between FDG-PET and MET-PET

International Nuclear Information System (INIS)

Kitagawa, Yoshimasa; Saitoh, Masaaki; Nakamura, Mikiko

2007-01-01

Inductive chemoradiotherapy has played an important role in preserving organs and functions in patients with oral squamous cell carcinoma (SCC). To determine whether a reduced form of surgery should be performed after chemoradiotherapy, accurate evaluation of residual tumor cells is essential. We investigated the clinical value of positron emission tomography with 18 F labeled fluorodeoxyglucose (FDG-PET) in the management of oral SCCs. Forty-five patients underwent two FDG-PET studies, one prior to and one at 6 weeks after the chemoradiotherapy. Pretreatment FDG-PET was useful in predicting the response to treatment. Posttreatment FDG-PET could evaluate residual viable cells and prognosis. Organ preservation may be feasible based on PET evaluation. Hence FDG-PET is a valuable tool in the treatment of oral cancer. 11 C-Methionine (MET) is another promising tracer for PET that can be used to assess metabolic demand for amino acids in cancer cells. A MET-PET and FDG-PET study was performed during the same period to investigate diagnostic accuracy in 40 oral malignancies. Sensitivity and positive predictive value of MET-PET were 95% and 100%, respectively, and were comparable with those of FDG-PET. Further study is required to determine the diagnostic significance of MET-PET in evaluating response to chemoradiotherapy. (author)

THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy - The Bad Berka Experience.

Science.gov (United States)

Baum, Richard P; Kulkarni, Harshad R

2012-01-01

The acronym THERANOSTICS epitomizes the inseparability of diagnosis and therapy, the pillars of medicine and takes into account personalized management of disease for a specific patient. Molecular phenotypes of neoplasms can be determined by molecular imaging with specific probes using positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), or optical methods, so that the treatment is specifically targeted against the tumor and its environment. To meet these demands, we need to define the targets, ligands, coupling and labeling chemistry, the most appropriate radionuclides, biodistribution modifiers, and finally select the right patients for the personalized treatment. THERANOSTICS of neuroendocrine tumors (NETs) using Ga-68 labeled tracers for diagnostics with positron emission tomography/ computed tomography (PET/CT), and using Lu-177 or other metallic radionuclides for radionuclide therapy by applying the same peptide proves that personalized radionuclide therapy today is already a fact and not a fiction.

Comparison of FDG-PET and IMP-SPECT in patients with dementia with Lewy bodies

International Nuclear Information System (INIS)

Ishii, Kazunari; Hosaka, Kayo; Mori, Tetsuya; Mori, Etsuro

2004-01-01

To investigate regional differences in cerebral glucose metabolism and blood flow of dementia with Lewy bodies (DLB), we studied 7 subjects with DLB and 20 normal controls using F-18 fluorodeoxyglucose (FDG) and positron emission tomography (PET) and then examined the same 7 subjects and 20 other normal controls with I-123 iodoamphetamine (IMP) and single photon emission computed tomography (SPECT). The anatomically standardized images were produced with NEUROSTAT and the regional relative metabolic and perfusional values were calculated. The mean reduction ratios of FDG uptake in the DLB group relative to the mean normal controls in the parietal lobe and occipital lobe were 0.72 and 0.83, respectively, while the corresponding mean reduction ratios of IMP uptake were 0.81 and 0.88, respectively. In the DLB group, parietal FDG uptake was significantly lower than parietal IMP uptake (p<0.05), occipital FDG uptake was significantly lower than occipital IMP uptake (p<0.05), and parietal IMP uptake was significantly lower than occipital IMP uptake (p<0.01), but there was no difference between parietal and occipital FDG uptake. Our findings suggest that parietal metabolism and perfusion are severely affected in DLB patients, though the occipital metabolic and perfusional reduction is thought to be a feature of DLB. FDG-PET is thought to be superior to IMP-SPECT in detecting functional changes in the DLB brain. (author)

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.)

Practical use and implementation of PET in children in a hospital PET centre

DEFF Research Database (Denmark)

Borgwardt, Lise; Larsen, Helle Jung; Pedersen, Kate

2003-01-01

Children are not just small adults-they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use...... and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments......, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine....

Practical use and implementation of PET in children in a hospital PET centre

International Nuclear Information System (INIS)

Borgwardt, Lise; Larsen, Helle Jung; Pedersen, Kate; Hoejgaard, Liselotte

2003-01-01

Children are not just small adults - they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine. (orig.)

Practical use and implementation of PET in children in a hospital PET centre

Energy Technology Data Exchange (ETDEWEB)

Borgwardt, Lise; Larsen, Helle Jung; Pedersen, Kate; Hoejgaard, Liselotte [Department of Clinical Physiology, Nuclear Medicine and PET, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen (Denmark)

2003-10-01

Children are not just small adults - they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine. (orig.)

Bringing physiology into PET of the liver.

Science.gov (United States)

Keiding, Susanne

2012-03-01

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

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

18F-FDG PET-CT pattern in idiopathic normal pressure hydrocephalus.

Science.gov (United States)

Townley, Ryan A; Botha, Hugo; Graff-Radford, Jonathan; Boeve, Bradley F; Petersen, Ronald C; Senjem, Matthew L; Knopman, David S; Lowe, Val; Jack, Clifford R; Jones, David T

2018-01-01

Idiopathic normal pressure hydrocephalus (iNPH) is an important and treatable cause of neurologic impairment. Diagnosis is complicated due to symptoms overlapping with other age related disorders. The pathophysiology underlying iNPH is not well understood. We explored FDG-PET abnormalities in iNPH patients in order to determine if FDG-PET may serve as a biomarker to differentiate iNPH from common neurodegenerative disorders. We retrospectively compared 18 F-FDG PET-CT imaging patterns from seven iNPH patients (mean age 74 ± 6 years) to age and sex matched controls, as well as patients diagnosed with clinical Alzheimer's disease dementia (AD), Dementia with Lewy Bodies (DLB) and Parkinson's Disease Dementia (PDD), and behavioral variant frontotemporal dementia (bvFTD). Partial volume corrected and uncorrected images were reviewed separately. Patients with iNPH, when compared to controls, AD, DLB/PDD, and bvFTD, had significant regional hypometabolism in the dorsal striatum, involving the caudate and putamen bilaterally. These results remained highly significant after partial volume correction. In this study, we report a FDG-PET pattern of hypometabolism in iNPH involving the caudate and putamen with preserved cortical metabolism. This pattern may differentiate iNPH from degenerative diseases and has the potential to serve as a biomarker for iNPH in future studies. These findings also further our understanding of the pathophysiology underlying the iNPH clinical presentation.

Feasibility and acceptance of simultaneous amyloid PET/MRI

International Nuclear Information System (INIS)

Schuetz, Lisa; Tiepolt, Solveig; Werner, Peter; Jochimsen, Thies; Rullmann, Michael; Sattler, Bernhard; Patt, Marianne; Barthel, Henryk; Lobsien, Donald; Fritzsch, Dominik; Hoffmann, Karl-Titus; Schroeter, Matthias L.; Villringer, Arno; Berrouschot, Joerg; Saur, Dorothee; Classen, Joseph; Hesse, Swen; Sabri, Osama; Gertz, Hermann-Josef

2016-01-01

Established Alzheimer's disease (AD) biomarker concepts classify into amyloid pathology and neuronal injury biomarkers, while recent alternative concepts classify into diagnostic and progression AD biomarkers. However, combined amyloid positron emission tomography/magnetic resonance imaging (PET/MRI) offers the chance to obtain both biomarker category read-outs within one imaging session, with increased patient as well as referrer convenience. The aim of this pilot study was to investigate this matter for the first time. 100 subjects (age 70 ± 10 yrs, 46 female), n = 51 with clinically defined mild cognitive impairment (MCI), n = 44 with possible/probable AD dementia, and n = 5 with frontotemporal lobe degeneration, underwent simultaneous [ 18 F]florbetaben or [ 11 C]PIB PET/MRI (3 Tesla Siemens mMR). Brain amyloid load, mesial temporal lobe atrophy (MTLA) by means of the Scheltens scale, and other morphological brain pathologies were scored by respective experts. The patients/caregivers as well as the referrers were asked to assess on a five-point scale the convenience related to the one-stop-shop PET and MRI approach. In three subjects, MRI revealed temporal lobe abnormalities other than MTLA. According to the National Institute on Aging-Alzheimer's Association classification, the combined amyloid-beta PET/MRI evaluation resulted in 31 %, 45 %, and 24 % of the MCI subjects being categorized as ''MCI-unlikely due to AD'', ''MCI due to AD-intermediate likelihood'', and ''MCI due to AD-high likelihood'', respectively. 50 % of the probable AD dementia patients were categorized as ''High level of evidence of AD pathophysiological process'', and 56 % of the possible AD dementia patients as ''Possible AD dementia - with evidence of AD pathophysiological process''. With regard to the International Working Group 2 classification, 36 subjects had both positive

Feasibility and acceptance of simultaneous amyloid PET/MRI

Energy Technology Data Exchange (ETDEWEB)

Schuetz, Lisa; Tiepolt, Solveig; Werner, Peter; Jochimsen, Thies; Rullmann, Michael; Sattler, Bernhard; Patt, Marianne; Barthel, Henryk [Leipzig University Hospital, Department of Nuclear Medicine, Leipzig (Germany); Lobsien, Donald; Fritzsch, Dominik; Hoffmann, Karl-Titus [Leipzig University Hospital, Department of Neuroradiology, Leipzig (Germany); Schroeter, Matthias L.; Villringer, Arno [Leipzig University Hospital and Max Planck Institute for Human Cognitive and Brain Sciences, Day Clinic for Cognitive Neurology, Leipzig (Germany); Leipzig University Hospital, IFB Adiposity Diseases, Leipzig (Germany); Berrouschot, Joerg [Clinical Centre Altenburger Land, Altenburg (Germany); Saur, Dorothee; Classen, Joseph [Leipzig University Hospital, Department of Neurology, Leipzig (Germany); Hesse, Swen; Sabri, Osama [Leipzig University Hospital, Department of Nuclear Medicine, Leipzig (Germany); Leipzig University Hospital, IFB Adiposity Diseases, Leipzig (Germany); Gertz, Hermann-Josef [Leipzig University Hospital, Department of Psychiatry, Leipzig (Germany)

2016-11-15

Established Alzheimer's disease (AD) biomarker concepts classify into amyloid pathology and neuronal injury biomarkers, while recent alternative concepts classify into diagnostic and progression AD biomarkers. However, combined amyloid positron emission tomography/magnetic resonance imaging (PET/MRI) offers the chance to obtain both biomarker category read-outs within one imaging session, with increased patient as well as referrer convenience. The aim of this pilot study was to investigate this matter for the first time. 100 subjects (age 70 ± 10 yrs, 46 female), n = 51 with clinically defined mild cognitive impairment (MCI), n = 44 with possible/probable AD dementia, and n = 5 with frontotemporal lobe degeneration, underwent simultaneous [{sup 18}F]florbetaben or [{sup 11}C]PIB PET/MRI (3 Tesla Siemens mMR). Brain amyloid load, mesial temporal lobe atrophy (MTLA) by means of the Scheltens scale, and other morphological brain pathologies were scored by respective experts. The patients/caregivers as well as the referrers were asked to assess on a five-point scale the convenience related to the one-stop-shop PET and MRI approach. In three subjects, MRI revealed temporal lobe abnormalities other than MTLA. According to the National Institute on Aging-Alzheimer's Association classification, the combined amyloid-beta PET/MRI evaluation resulted in 31 %, 45 %, and 24 % of the MCI subjects being categorized as ''MCI-unlikely due to AD'', ''MCI due to AD-intermediate likelihood'', and ''MCI due to AD-high likelihood'', respectively. 50 % of the probable AD dementia patients were categorized as ''High level of evidence of AD pathophysiological process'', and 56 % of the possible AD dementia patients as ''Possible AD dementia - with evidence of AD pathophysiological process''. With regard to the International Working Group 2 classification, 36 subjects had both

Kinetic modeling in PET imaging of hypoxia

DEFF Research Database (Denmark)

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

2014-01-01

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

Optimal time-point for 68Ga-PSMA-11 PET/CT imaging in assessment of prostate cancer: feasibility of sterile cold-kit tracer preparation?

Science.gov (United States)

Beheshti, Mohsen; Paymani, Zeinab; Brilhante, Joana; Geinitz, Hans; Gehring, Daniela; Leopoldseder, Thomas; Wouters, Ludovic; Pirich, Christian; Loidl, Wolfgang; Langsteger, Werner

2018-07-01

In this prospective study, we evaluated the optimal time-point for 68 Ga-PSMA-11 PET/CT acquisition in the assessment of prostate cancer. We also examined, for the first time the feasibility of tracer production using a PSMA-11 sterile cold-kit in the clinical workflow of PET/CT centres. Fifty prostate cancer patients (25 staging, 25 biochemical recurrence) were enrolled in this study. All patients received an intravenous dose of 2.0 MBq/kg body weight 68 Ga-PSMA-11 prepared using a sterile cold kit (ANMI SA, Liege, Belgium), followed by an early (20 min after injection) semi-whole-body PET/CT scan and a standard-delay (100 min after injection) abdominopelvic PET/CT scan. The detection rates with 68 Ga-PSMA-11 were compared between the two acquisitions. The pattern of physiological background activity and tumour to background ratio were also analysed. The total preparation time was reduced to 5 min using the PSMA-11 sterile cold kit, which improved the final radionuclide activity by about 30% per single 68 Ge/ 68 Ga generator elution. Overall, 158 pathological lesions were analysed in 45 patients (90%) suggestive of malignancy on both (early and standard-delay) 68 Ga-PSMA PET/CT images. There was a significant (p PET/CT imaging seems to provide a detection rate comparable with that of standard-delay imaging. Furthermore, the shorter preparation time using the 68 Ga-PSMA-11 sterile cold kit and promising value of early PET/CT scanning could allow tailoring of imaging protocols which may reduce the costs and improve the time efficiency in PET/CT centres.

Cognitive correlates of α4β2 nicotinic acetylcholine receptors in mild Alzheimer's dementia.

Science.gov (United States)

Sabri, Osama; Meyer, Philipp M; Gräf, Susanne; Hesse, Swen; Wilke, Stephan; Becker, Georg-Alexander; Rullmann, Michael; Patt, Marianne; Luthardt, Julia; Wagenknecht, Gudrun; Hoepping, Alexander; Smits, Rene; Franke, Annegret; Sattler, Bernhard; Tiepolt, Solveig; Fischer, Steffen; Deuther-Conrad, Winnie; Hegerl, Ulrich; Barthel, Henryk; Schönknecht, Peter; Brust, Peter

2018-06-01

In early Alzheimer's dementia, there is a need for PET biomarkers of disease progression with close associations to cognitive dysfunction that may aid to predict further cognitive decline and neurodegeneration. Amyloid biomarkers are not suitable for that purpose. The α4β2 nicotinic acetylcholine receptors (α4β2-nAChRs) are widely abundant in the human brain. As neuromodulators they play an important role in cognitive functions such as attention, learning and memory. Post-mortem studies reported lower expression of α4β2-nAChRs in more advanced Alzheimer's dementia. However, there is ongoing controversy whether α4β2-nAChRs are reduced in early Alzheimer's dementia. Therefore, using the recently developed α4β2-nAChR-specific radioligand (-)-18F-flubatine and PET, we aimed to quantify the α4β2-nAChR availability and its relationship to specific cognitive dysfunction in mild Alzheimer's dementia. Fourteen non-smoking patients with mild Alzheimer's dementia, drug-naïve for cholinesterase therapy, were compared with 15 non-smoking healthy controls matched for age, sex and education by applying (-)-18F-flubatine PET together with a neuropsychological test battery. The one-tissue compartment model and Logan plot method with arterial input function were used for kinetic analysis to obtain the total distribution volume (VT) as the primary, and the specific binding part of the distribution volume (VS) as the secondary quantitative outcome measure of α4β2-nAChR availability. VS was determined by using a pseudo-reference region. Correlations between VT within relevant brain regions and Z-scores of five cognitive functions (episodic memory, executive function/working memory, attention, language, visuospatial function) were calculated. VT (and VS) were applied for between-group comparisons. Volume of interest and statistical parametric mapping analyses were carried out. Analyses revealed that in patients with mild Alzheimer's dementia compared to healthy controls

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.

Bone formation rather than inflammation reflects ankylosing spondylitis activity on PET-CT: a pilot study.

Science.gov (United States)

Bruijnen, Stefan T G; van der Weijden, Mignon A C; Klein, Joannes P; Hoekstra, Otto S; Boellaard, Ronald; van Denderen, J Christiaan; Dijkmans, Ben A C; Voskuyl, Alexandre E; van der Horst-Bruinsma, Irene E; van der Laken, Conny J

2012-04-02

Positron Emission Tomography - Computer Tomography (PET-CT) is an interesting imaging technique to visualize Ankylosing Spondylitis (AS) activity using specific PET tracers. Previous studies have shown that the PET tracers [18F]FDG and [11C](R)PK11195 can target inflammation (synovitis) in rheumatoid arthritis (RA) and may therefore be useful in AS. Another interesting tracer for AS is [18F]Fluoride, which targets bone formation. In a pilot setting, the potential of PET-CT in imaging AS activity was tested using different tracers, with Magnetic Resonance Imaging (MRI) and conventional radiographs as reference. In a stepwise approach different PET tracers were investigated. First, whole body [18F]FDG and [11C](R)PK11195 PET-CT scans were obtained of ten AS patients fulfilling the modified New York criteria. According to the BASDAI five of these patients had low and five had high disease activity. Secondly, an extra PET-CT scan using [18F]Fluoride was made of two additional AS patients with high disease activity. MRI scans of the total spine and sacroiliac joints were performed, and conventional radiographs of the total spine and sacroiliac joints were available for all patients. Scans and radiographs were visually scored by two observers blinded for clinical data. No increased [18F]FDG and [11C](R)PK11195 uptake was noticed on PET-CT scans of the first 10 patients. In contrast, MRI demonstrated a total of five bone edema lesions in three out of 10 patients. In the two additional AS patients scanned with [18F]Fluoride PET-CT, [18F]Fluoride depicted 17 regions with increased uptake in both vertebral column and sacroiliac joints. In contrast, [18F]FDG depicted only three lesions, with an uptake of five times lower compared to [18F]Fluoride, and again no [11C](R)PK11195 positive lesions were found. In these two patients, MRI detected nine lesions and six out of nine matched with the anatomical position of [18F]Fluoride uptake. Conventional radiographs showed structural

THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy - The Bad Berka Experience

Directory of Open Access Journals (Sweden)

Richard P. Baum, Harshad R. Kulkarni

2012-01-01

Full Text Available The acronym THERANOSTICS epitomizes the inseparability of diagnosis and therapy, the pillars of medicine and takes into account personalized management of disease for a specific patient. Molecular phenotypes of neoplasms can be determined by molecular imaging with specific probes using positron emission tomography (PET, single photon emission computed tomography (SPECT, magnetic resonance imaging (MRI, or optical methods, so that the treatment is specifically targeted against the tumor and its environment. To meet these demands, we need to define the targets, ligands, coupling and labeling chemistry, the most appropriate radionuclides, biodistribution modifiers, and finally select the right patients for the personalized treatment. THERANOSTICS of neuroendocrine tumors (NETs using Ga-68 labeled tracers for diagnostics with positron emission tomography/ computed tomography (PET/CT, and using Lu-177 or other metallic radionuclides for radionuclide therapy by applying the same peptide proves that personalized radionuclide therapy today is already a fact and not a fiction.

'Serial review on clinical PET tracers'. Application of health insurance of [15O]oxygen PET and [18F]FDG-PET

International Nuclear Information System (INIS)

Torizuka, Kanji

2009-01-01

As regards the application required for health insurance of PET, the Ministry of Health, Labour and Welfare indicates the following procedures: first, request a permission to the Ministry of Health, Labour and Welfare for the clinical use of the automatic synthetic instrument for PET drug, approved according to the Pharmaceutical Affairs Law. Second, put into practice the use of PET test, under the highly advanced medicine premises. Then, in case of gathered positive results, the health insurance is approved for this PET test. Thus, following the above mentioned procedures, first, the use of [ 15 O] oxygen PET was approved in April 1996. Second, the use of [ 18 F]FDG-PET was approved in 12 different diseases: epilepsy, ischemic heart disease and 10 different types of cancer, in April 2002. Third, in April 2006, a additional 3 types of cancer were approved. Now, we are in the process to get the health insurance of all kinds of malignant tumors (cancer and sarcoma) except for the early gastric cancer. (author)

Preclinical in vitro and in vivo evaluation of [11C]SNAP-7941 – the first PET tracer for the melanin concentrating hormone receptor 1

International Nuclear Information System (INIS)

Philippe, Cécile; Nics, Lukas; Zeilinger, Markus; Kuntner, Claudia; Wanek, Thomas; Mairinger, Severin; Shanab, Karem; Spreitzer, Helmut; Viernstein, Helmut; Wadsak, Wolfgang; Mitterhauser, Markus

2013-01-01

Introduction: Due to its involvement in a variety of pathologies (obesity, diabetes, gut inflammation and depression), the melanin concentrating hormone receptor 1 (MCHR1) is a new target for the treatment of these lifestyle diseases. We previously presented the radiosynthesis of [ 11 C]SNAP-7941, the first potential PET tracer for the MCHR1. Methods: We herein present its in vitro and in vivo evaluation, including binding affinity, plasma stability, stability against liver mircrosomes and carboxylesterase, lipohilicity, biodistribution, in vivo metabolism and small-animal PET. Results: [ 11 C]SNAP-7941 evinced high stability against liver microsomes, carboxylesterase and in human plasma. The first small-animal PET experiments revealed a 5 fold increased brain uptake after Pgp/BCRP inhibition. Therefore, it can be assumed that [ 11 C]SNAP-7941 is a Pgp/BCRP substrate. No metabolites were found in brain. Conclusion: On the basis of these experiments with healthy rats, the suitability of [ 11 C]SNAP-7941 for the visualisation of central and peripheral MCHR1 remains speculative

T156. IN VIVO CHARACTERIZATION OF THE FIRST AGONIST DOPAMINE D1 RECEPTORS PET IMAGING TRACER [18F]MNI-968 IN HUMAN

Science.gov (United States)

Tamagnan, Gilles; Barret, Olivier; Alagille, David; Carroll, Vincent; Madonia, Jennifer; Constantinescu, Cristian; SanDiego, Christine; Papin, Caroline; Morley, Thomas; Russell, David; McCarthy, Timothy; Zhang, Lei; Gray, David; Villalobos, Anna; Lee, Chewah; Chen, Jianqing; Seibyl, John; Marek, Kenneth

2018-01-01

Abstract Background D1 receptors, which couple to inhibitory G-proteins, have been shown to regulate neuronal growth and development, mediate some behavioral responses. Its function has been shown to be altered in both neurologic and psychiatric disorders. To date, there is a lack of agonist PET tracers for the D1 receptors labeled with 18F with relevance in clinical studies. We report the evaluation in non-human primates of [18F]MNI-968 (PF-06730110), a novel PET radiotracer of the D1 receptors Methods Four brain PET studies, 2 baselines and 2 blockade studies using PF-2562, a D1 partial agonist compound, were conducted for 90 min in two rhesus monkeys with [18F]MNI-968 (169 ± 31 MBq). [18F]PF-06730110 was administered at the same dose level for both monkeys as a bolus followed by a 2-hour infusion, with [18F]MNI-968 administered 30 min into the infusion. Additionally, six brain PET studies were conducted over 180 min (317 ± 49 MBq) in 6 healthy human volunteers (3 test/retest and 3 test). PET data were modeled with 2-tissue compartmental model (2T), Logan graphical analysis (LGA), and non-invasive Logan graphical analysis (NI-LGA) with cerebellar cortex as reference region to estimate total distribution volume VT, and binding potential BPND. For the blockade studies in rhesus monkeys, occupancy was estimated from BPND at baseline and post blockade. Results In rhesus monkeys, [18F]MNI-968 (PF-06730110), penetrated the brain with a peak whole-brain uptake up to ~3% of the injected dose at ~ 6 min post injection and showed a fast washout. The highest signal was found in the caudate, putamen, with moderate extrastriatal uptake. The lowest signal was in the cerebellum. BPND values were up to ~1.4 in the putamen. All three quantification methods (2T, LGA and NI-LGA) were in excellent agreement, with a similar estimated D1 receptors occupancy of PF-06730110 of ~40% for both monkeys in the caudate and putamen. In human, [18F]MNI-968 kinetics appeared to be faster

Correlation of Dynamic PET and Gene Array Data in Patients with Gastrointestinal Stromal Tumors

Directory of Open Access Journals (Sweden)

Ludwig G. Strauss

2012-01-01

Full Text Available Introduction. The results obtained with dynamic PET (dPET were compared to gene expression data obtained in patients with gastrointestinal stromal tumors (GIST. The primary aim was to assess the association of the dPET results and gene expression data. Material and Methods. dPET was performed following the injection of F-18-fluorodeoxyglucose (FDG in 22 patients with GIST. All patients were examined prior to surgery for staging purpose. Compartment and noncompartment models were used for the quantitative evaluation of the dPET examinations. Gene array data were based on tumor specimen obtained by surgery after the PET examinations. Results. The data analysis revealed significant correlations for the dPET parameters and the expression of zinc finger genes (znf43, znf85, znf91, znf189. Furthermore, the transport of FDG (k1 was associated with VEGF-A. The cell cycle gene cyclin-dependent kinase inhibitor 1C was correlated with the maximum tracer uptake (SUVmax in the tumors. Conclusions. The data demonstrate a dependency of the tracer kinetics on genes associated with prognosis in GIST. Furthermore, angiogenesis and cell proliferation have an impact on the tracer uptake.

Functional neuroimaging in epilepsy: FDG-PET and SPECT

International Nuclear Information System (INIS)

Lee, Sang Kun; Lee, Dong Soo

2003-01-01

Finding epileptogenic zone is the most important step for the successful epilepsy surgery. F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and single photon emission computed tomography (SPECT) can be used in the localization of epileptogenic foci. In medial temporal lobe epilepsy, the diagnostic sensitivity of FDG-PET and ictal SPECT is excellent. However, detection of hippocampal sclerosis by MRI is so certain that use of FDG-PET and ictal SPECT in medial temporal lobe epilepsy is limited for some occasions. In neocortical epilepsy, the sensitivities of FDG-PET or ictal SPECT are fair. However, FDG-PET and ictal SPECT can have a crucial role in the localization of epileptogenic foci for non-lesional neocortical epilepsy. Interpretation of FDG-PET has been recently advanced by voxel-based analysis and automatic volume of interest analysis based on a population template. Both analytical methods can aid the objective diagnosis of epileptogenic foci. lctal SPECT was analyzed using subtraction methods and voxel-based analysis. Rapidity of injection of tracers, ictal EEG findings during injection of tracer, and repeated ictal SPECT were important technical issues of ictal SPECT. SPECT can also be used in the evaluation of validity of Wada test

Functional neuroimaging in epilepsy: FDG-PET and SPECT

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Kun; Lee, Dong Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2003-02-01

Finding epileptogenic zone is the most important step for the successful epilepsy surgery. F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and single photon emission computed tomography (SPECT) can be used in the localization of epileptogenic foci. In medial temporal lobe epilepsy, the diagnostic sensitivity of FDG-PET and ictal SPECT is excellent. However, detection of hippocampal sclerosis by MRI is so certain that use of FDG-PET and ictal SPECT in medial temporal lobe epilepsy is limited for some occasions. In neocortical epilepsy, the sensitivities of FDG-PET or ictal SPECT are fair. However, FDG-PET and ictal SPECT can have a crucial role in the localization of epileptogenic foci for non-lesional neocortical epilepsy. Interpretation of FDG-PET has been recently advanced by voxel-based analysis and automatic volume of interest analysis based on a population template. Both analytical methods can aid the objective diagnosis of epileptogenic foci. lctal SPECT was analyzed using subtraction methods and voxel-based analysis. Rapidity of injection of tracers, ictal EEG findings during injection of tracer, and repeated ictal SPECT were important technical issues of ictal SPECT. SPECT can also be used in the evaluation of validity of Wada test.

[{sup 11}C]FMAU and [{sup 18}F]FHPG as PET tracers for herpes simplex virus thymidine kinase enzyme activity and human cytomegalovirus infections

Energy Technology Data Exchange (ETDEWEB)

Vries, Erik F.J. de E-mail: e.f.j.de.vries@pet.azg.nl; Waarde, Aren van; Harmsen, Marco C.; Mulder, Nanno H.; Vaalburg, Willem; Hospers, Geke A.P

2000-02-01

[{sup 11}C]-2'-Fluoro-5-methyl-1-{beta}-D-arabinofuranosyluracil ([{sup 11}C]FMAU) and [{sup 18}F]-9-[(3-fluoro-1-hydroxy-2-propoxy)methyl]guanine ([{sup 18}F]FHPG), radiolabeled representatives of two classes of antiviral agents, were evaluated as tracers for measuring herpes simplex virus thymidine kinase (HSV-tk) enzyme activity after gene transfer and as tracers for localization of active human cytomegalovirus (HCMV) infections. In vitro accumulation experiments revealed that both [{sup 11}C]FMAU and [{sup 18}F]FHPG accumulated significantly more in HSV-tk expressing cells than they did in control cells. [{sup 18}F]FHPG uptake in HSV-tk expressing cells, however, was found to depend strongly on the cell line used, which might be due to cell type dependent membrane transport or cell type dependent substrate specific susceptibility of the enzyme. In vitro, both tracers exhibited a good selectivity for accumulation in HCMV-infected human umbilical vein endothelial cells over uninfected cells. In contrast to [{sup 18}F]FHPG, [{sup 11}C]FMAU uptake in control cells was relatively high due to phosphorylation of the tracer by host kinases. Therefore, [{sup 18}F]FHPG appears to be the more selective tracer not only to predict HSV-tk gene therapy outcome, but also to localize active HCMV infections with PET.

18F-FET-PET in Primary Hyperparathyroidism

DEFF Research Database (Denmark)

Krakauer, Martin; Kjær, Andreas; Bennedbæk, Finn Noe

2016-01-01

-isotope parathyroid subtraction single photon emission computed tomography had determined the exact location of the parathyroid adenoma. A dynamic FET PET/CT scan was performed with subsequent visual evaluation and calculation of target-to-background (TBR; parathyroid vs. thyroid). The maximum TBR in the two patients......Preoperative localisation of the diseased parathyroid gland(s) in primary hyperparathyroidism (PHP) is a prerequisite for subsequent minimally invasive surgery. Recently, as alternatives to conventional sestamibi parathyroid scintigraphy, the (11)C-based positron emission tomography (PET) tracers...... methionine and choline have shown promise for this purpose. We evaluated the feasibility of using the (18)F-based PET tracer fluoroethyl-l-tyrosine (FET), as the longer half-life of (18)F makes it logistically more favourable. As a proof-of-concept study, we included two patients with PHP in which dual...

Characteristics of cerebral glucose utilization in dementia

Energy Technology Data Exchange (ETDEWEB)

Matsuzawa, Taiju; Matsui, Hiroshige; Meguro, Kenichi; Ueda, Masamichi; Yamada, Kenji; Yamaguchi, Tatsuo; Itoh, Masatoshi; Hatazawa, Jun; Kinomura, Shigeo (Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis and Cancer)

1990-12-01

To make clear the characteristics of cerebral glucose utilization in dementia, PET studies with 18F-FDG were carried out. Taking the pattern of 18F-FDG utilization, dementia can be subdivided into two types. One type shows a simultaneous and symmetrical reduction glucose utilization in the posterior part of neocortex covering the temporal, parietal and occipital association cortices. This is referred to as type I. Although this type constitutes only about 1/5 of all dementia patients, it is considered the fundamental type of dementia. Aside from this, there is type wherein a simultaneous and symmetrical reduction in glucose utilization of the neocortex. This is type II. It constitutes about 4/5 of all dementia patients which is far more type I. There are no essential difference in the characteristics of cerebral glucose utilization in AD and MID. However, with regards the mean, AD is lower than MID. Various organic defect in neocortex do not correlate with the global reduction in glucose utilization in dementia patients. These results suggest that the reduction in glucose utilization in dementia may be functional disorder. (author).

Characteristics of cerebral glucose utilization in dementia

International Nuclear Information System (INIS)

Matsuzawa, Taiju; Matsui, Hiroshige; Meguro, Kenichi; Ueda, Masamichi; Yamada, Kenji; Yamaguchi, Tatsuo; Itoh, Masatoshi; Hatazawa, Jun; Kinomura, Shigeo

1990-01-01

To make clear the characteristics of cerebral glucose utilization in dementia, PET studies with 18F-FDG were carried out. Taking the pattern of 18F-FDG utilization, dementia can be subdivided into two types. One type shows a simultaneous and symmetrical reduction glucose utilization in the posterior part of neocortex covering the temporal, parietal and occipital association cortices. This is referred to as type I. Although this type constitutes only about 1/5 of all dementia patients, it is considered the fundamental type of dementia. Aside from this, there is type wherein a simultaneous and symmetrical reduction in glucose utilization of the neocortex. This is type II. It constitutes about 4/5 of all dementia patients which is far more type I. There are no essential difference in the characteristics of cerebral glucose utilization in AD and MID. However, with regards the mean, AD is lower than MID. Various organic defect in neocortex do not correlate with the global reduction in glucose utilization in dementia patients. These results suggest that the reduction in glucose utilization in dementia may be functional disorder. (author)

Neuropsychiatry: PET and SPECT

International Nuclear Information System (INIS)

Quintana F, Juan Carlos

2002-01-01

Functional brain imaging with PET and SPECT have a definitive and well established role in the investigation of a variety of conditions such as dementia, epilepsy and drug addiction. With these methods it is possible to detect early rCBF (regional Cerebral Blood Flow) changes seen in dementia (even before clinical symptoms) and differentiate Alzheimer's disease from other dementias by means of the rCBF pattern change. 18-F-FDG PET imaging is a useful tool in partial epilepsy because both rCBF and brain metabolism are compromised at the epileptogenic focus. During the seizure, rCBF dramatically increases locally. Using SPECT it is possible to locate such foci with 97% accuracy. In drug addiction, particularly with cocaine, functional imaging has proven to be very sensitive to detect brain flow and metabolism derangement early in the course of this condition. These findings are important in many ways: prognostic value, they are used as a powerful reinforcement tool and to monitor functional recovery with rehabilitation. There are many other conditions in which functional brain imaging is of importance such as acute stroke treatment assessment, trauma rehabilitation and in psychiatric and abnormal movement diseases specially with the development of receptor imaging (au)

Comparison of [68Ga]Ga-PSMA-11 PET/CT with [18F]NaF PET/CT in the evaluation of bone metastases in metastatic prostate cancer patients prior to radionuclide therapy.

Science.gov (United States)

Uprimny, Christian; Svirydenka, Anna; Fritz, Josef; Kroiss, Alexander Stephan; Nilica, Bernhard; Decristoforo, Clemens; Haubner, Roland; von Guggenberg, Elisabeth; Buxbaum, Sabine; Horninger, Wolfgang; Virgolini, Irene Johanna

2018-05-16

The purpose of this study was to investigate the diagnostic performance of 68 Ga-PSMA-11 PET/CT in the evaluation of bone metastases in metastatic prostate cancer (PC) patients scheduled for radionuclide therapy in comparison to [ 18 F]sodium fluoride ( 18 F-NaF) PET/CT. Sixteen metastatic PC patients with known skeletal metastases, who underwent both 68 Ga-PSMA-11 PET/CT and 18 F-NaF PET/CT for assessment of metastatic burden prior to radionuclide therapy, were analysed retrospectively. The performance of both tracers was calculated on a lesion-based comparison. Intensity of tracer accumulation of pathologic bone lesions on 18 F-NaF PET and 68 Ga-PSMA-11 PET was measured with maximum standardized uptake values (SUV max ) and compared to background activity of normal bone. In addition, SUV max values of PET-positive bone lesions were analysed with respect to morphologic characteristics on CT. Bone metastases were either confirmed by CT or follow-up PET scan. In contrast to 468 PET-positive lesions suggestive of bone metastases on 18 F-NaF PET, only 351 of the lesions were also judged positive on 68 Ga-PSMA-11 PET (75.0%). Intensity of tracer accumulation of pathologic skeletal lesions was significantly higher on 18 F-NaF PET compared to 68 Ga-PSMA-11 PET, showing a median SUV max of 27.0 and 6.0, respectively (p PET, with a median SUV max of 1.0 in comparison to 2.7 on 18 F-NaF PET; however, tumour to background ratio was significantly higher on 18 F-NaF PET (9.8 versus 5.9 on 68 Ga-PSMA-11 PET; p = 0.042). Based on morphologic lesion characterisation on CT, 18 F-NaF PET revealed median SUV max values of 23.6 for osteosclerotic, 35.0 for osteolytic, and 19.0 for lesions not visible on CT, whereas on 68 Ga-PSMA-11 PET median SUV max values of 5.0 in osteosclerotic, 29.5 in osteolytic, and 7.5 in lesions not seen on CT were measured. Intensity of tracer accumulation between 18 F-NaF PET and 68 Ga-PSMA-11 PET was significantly higher in osteosclerotic (p PET

Brain {sup 18}F-FDG PET-MRI co registration: iconographic essay;PET-RM neurologico com FDG-{sup 18}F: ensaio iconografico

Energy Technology Data Exchange (ETDEWEB)

Cavalcanti Filho, Jose Leite Gondim; Machado Neto, Luiz de Souza, E-mail: leite_jose@yahoo.co [Multi Imagem PET, Rio de Janeiro, RJ (Brazil); Fonseca, Lea Mirian Barbosa da; Gasparetto, Emerson Leandro [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Domingues, Romeu Cortes; Domingues, Roberto Cortes [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil)

2010-05-15

The combination of positron emission tomography (PET) with magnetic resonance imaging (MRI) has been the subject of several studies in recent years. Positron emission tomography is the most sensitive and specific imaging modality in the detection of metabolic changes, but presents limited spatial resolution. On the other hand, MRI presents a significant spatial resolution, besides evaluating soft tissues signal intensity with excellent contrast resolution. The present iconographic essay is aimed at demonstrating the potential clinical application of PET/MRI co registration. The studies were performed in a dedicated PET unit with {sup 18}F-fluorodeoxyglucose (FDG) as radiopharmaceutical and co registered with 1.5 T or 3 T brain MRI. The brain images fusion software presents an already well-established accuracy, so a significant synergy between a functional PET study and an excellent MRI anatomical detail is achieved. The most attractive clinical applications of this approach are the following: epileptogenic zone assessment in patients refractory to drug therapy, identification of patients with cognitive impairment at higher risk for progression to dementia and differentiation of dementias and Parkinsonian syndromes. (author)

Carbon-11 and Fluorine-18 Labeled Amino Acid Tracers for Positron Emission Tomography Imaging of Tumors

Science.gov (United States)

Sun, Aixia; Liu, Xiang; Tang, Ganghua

2017-12-01

Tumor cells have an increased nutritional demand for amino acids(AAs) to satisfy their rapid proliferation. Positron-emitting nuclide labeled AAs are interesting probes and are of great importance for imaging tumors using positron emission tomography (PET). Carbon-11 and fluorine-18 labeled AAs include the [1-11C] amino acids, labeling alpha-C- amino acids, the branched-chain of amino acids and N-substituted carbon-11 labeled amino acids. These tracers target protein synthesis or amino acid(AA) transport, and their uptake mechanism mainly involves AA transport. AA PET tracers have been widely used in clinical settings to image brain tumors, neuroendocrine tumors, prostate cancer, breast cancer, non–small cell lung cancer (NSCLC) and hepatocellular carcinoma. This review focuses on the fundamental concepts and the uptake mechanism of AAs, AA PET tracers and their clinical applications.

The preliminary study of {sup 18}F-FDG PET in diagnosis of Alzheimer's disease

Energy Technology Data Exchange (ETDEWEB)

Ma, Y.; Zhang, X.; Le, D. [Capital Univ. of Medical Sciences, Beijing (Switzerland)] [and others

2000-07-01

To investigate the imaging characteristic and diagnostic criteria of 18F-FDG brain PET in detecting Alzheimer's disease (AD). The study included in 12 normal subject, 12 patients with AD, 6 patients with vascular dementia, 3 patients with Lewy body disease (LBD) and 2 patients with mixed dementia. The dementia severity was measured by ESD and MMSE. 12 cases had mild, 7 moderate and 4 severe dementia. 23 patients and 6 normal subjects underwent MR imaging of the brain. All participants fasted for at least 6 hours. 40 minutes after intravenous administration of 185-370 MBq 18F-FDG, 2D brain scan in 25 cases and 3D scan in 10 cases were performed using SIEMENS ECAT 47 scanner. The transaxial, coronal and sagittal images were then reconstructed by computer. At the same time, semiquantitative analysis was also applied to help evaluation using the ratio of mean radioactivity between cerebral lobe to cerebellum (Rcl/cb). In normal subjects PET scan showed clear images of cerebral cortex, basal ganglia, thalamus and cerebellum with symmetrical distribution of radioactivity. 22 of 23 patients were found to have decreased uptake of FDG in the brain. 20 patients had cerebral atrophy and it also appeared in 6 normal elder people. PET images for Alzheimer's disease were classified in 6 normal elder people. PET image for Alzheimer's 3 patterns: bilateral parietal hypo metabolism in 5 cases, bilateral temporo-parietal hypo metabolism in 4 cases and unilateral temporo-parietal hypo metabolism in 3 cases. The Rcl/cb of AD patents in parietal and temporal was significantly decreased than normal subjects (p<0.05). PET images for non-AD dementia were also classified 3 patterns: multiple and asymmetrical patch foci with decreased radioactivity in 8 cases, bilateral temporo-parietal with diffuse cortical hypo metabolism in 2 cases, and normal imaging in 1 case. The hypo metabolic involvement was accorded with severity of dementia. The more dementia had, the bigger

Progress of PET imaging in Schizophrenia

International Nuclear Information System (INIS)

Cai Li; Gao Shuo

2011-01-01

PET is an important functional neuroimaging technique that can be used to assessment of cerebral metabolic activity and blood flow and identifies the distribution of important neurotransmitters in the human brain. Compared with other conventional imaging techniques, PET enables regional cerebral glucose metabolism, blood flow, dopaminergic and serotonergic receptor function to be assessed qualitatively and quantitatively. In recent years, PET increasingly being used greatly to advance our understanding of the neurobiology and pathophysiology of schizophrenia. This review focuses on the use of PET tracers in identifying regional brain abnormalities and regions associated with cognitive functioning in schizophrenia. (authors)

Improving PET Quantification of Small Animal [68Ga]DOTA-Labeled PET/CT Studies by Using a CT-Based Positron Range Correction.

Science.gov (United States)

Cal-Gonzalez, Jacobo; Vaquero, Juan José; Herraiz, Joaquín L; Pérez-Liva, Mailyn; Soto-Montenegro, María Luisa; Peña-Zalbidea, Santiago; Desco, Manuel; Udías, José Manuel

2018-01-19

Image quality of positron emission tomography (PET) tracers that emits high-energy positrons, such as Ga-68, Rb-82, or I-124, is significantly affected by positron range (PR) effects. PR effects are especially important in small animal PET studies, since they can limit spatial resolution and quantitative accuracy of the images. Since generators accessibility has made Ga-68 tracers wide available, the aim of this study is to show how the quantitative results of [ 68 Ga]DOTA-labeled PET/X-ray computed tomography (CT) imaging of neuroendocrine tumors in mice can be improved using positron range correction (PRC). Eighteen scans in 12 mice were evaluated, with three different models of tumors: PC12, AR42J, and meningiomas. In addition, three different [ 68 Ga]DOTA-labeled radiotracers were used to evaluate the PRC with different tracer distributions: [ 68 Ga]DOTANOC, [ 68 Ga]DOTATOC, and [ 68 Ga]DOTATATE. Two PRC methods were evaluated: a tissue-dependent (TD-PRC) and a tissue-dependent spatially-variant correction (TDSV-PRC). Taking a region in the liver as reference, the tissue-to-liver ratio values for tumor tissue (TLR tumor ), lung (TLR lung ), and necrotic areas within the tumors (TLR necrotic ) and their respective relative variations (ΔTLR) were evaluated. All TLR values in the PRC images were significantly different (p DOTA-labeled PET/CT imaging of mice with neuroendocrine tumors, hence demonstrating that these techniques could also ameliorate the deleterious effect of the positron range in clinical PET imaging.

New SPECT tracers: Example of tracers of proteoglycans and melanin; Nouveaux traceurs TEMP: exemple des traceurs des proteoglycanes et de la melanine

Energy Technology Data Exchange (ETDEWEB)

Cachin, F.; Mestas, D.; Kelly, A.; Merlin, C.; Veyre, A.; Maublant, J. [CRLCC Jean-Perrin, Service de Medecine Nucleaire, 63 - Clermont-Ferrand (France); Cachin, F.; Chezal, J.M.; Miot-Noirault, E.; Moins, N.; Auzeloux, P.; Vidal, A.; Bonnet-Duquennoy, M.; Boisgard, S.; D' Incan, M.; Madelmont, J.C.; Maublant, J. [Universite d' Auvergne, EA 4231, 63 - Clermont-Ferrand (France); Boisgard, S. [CHRU Gabriel-Montpied, Service d' Orthopedie, 63 - Clermont-Ferrand (France); D' Incan, M. [CHRU Gabriel-Montpied, Service de Dermatologie, 63 - Clermont-Ferrand (France); Redini, F. [Inserm, U957-EA3822, Faculte de Medecine, 44 - Nantes (France); Filaire, M. [Universite d' Auvergne, Lab. d' Anatomie, 63 - Clermont-Ferrand (France)

2009-02-15

The majority of research program on new radiopharmaceuticals turn to tracers used for positron emission tomography (PET). Only a few teams work on new non fluorine labeled tracers. However, the coming of SPECT/CT gamma cameras, the arrival of semi-conductors gamma cameras should boost the development of non-PET tracers. We exhibit in this article the experience acquired by our laboratory in the conception and design of two new non fluorine labelled compounds. The {sup 99m}Tc-N.T.P. 15-5 (N.T.P. 15-5 for N-[tri-ethyl-ammonium]-3-propyl-[15]ane-N5) which binds to proteoglycans could be used for the diagnosis and staging of osteoarthritis and chondrosarcoma. The iodo benzamides, specific to the melanin, are nowadays compared to {sup 18}F-fluorodeoxyglucose in a phase III clinical trial for the diagnosis and detection of melanoma metastasis. Our last development focus on N-[2-(diethyl-amino)ethyl]-4 and 2-iodo benzamides respectively B.Z.A. and B.Z.A.2 hetero-aromatic analogues usable for melanoma treatment. (authors)

Right Limbic FDG-PET Hypometabolism Correlates with Emotion Recognition and Attribution in Probable Behavioral Variant of Frontotemporal Dementia Patients.

Directory of Open Access Journals (Sweden)

Chiara Cerami

Full Text Available The behavioural variant of frontotemporal dementia (bvFTD is a rare disease mainly affecting the social brain. FDG-PET fronto-temporal hypometabolism is a supportive feature for the diagnosis. It may also provide specific functional metabolic signatures for altered socio-emotional processing. In this study, we evaluated the emotion recognition and attribution deficits and FDG-PET cerebral metabolic patterns at the group and individual levels in a sample of sporadic bvFTD patients, exploring the cognitive-functional correlations. Seventeen probable mild bvFTD patients (10 male and 7 female; age 67.8±9.9 were administered standardized and validated version of social cognition tasks assessing the recognition of basic emotions and the attribution of emotions and intentions (i.e., Ekman 60-Faces test-Ek60F and Story-based Empathy task-SET. FDG-PET was analysed using an optimized voxel-based SPM method at the single-subject and group levels. Severe deficits of emotion recognition and processing characterized the bvFTD condition. At the group level, metabolic dysfunction in the right amygdala, temporal pole, and middle cingulate cortex was highly correlated to the emotional recognition and attribution performances. At the single-subject level, however, heterogeneous impairments of social cognition tasks emerged, and different metabolic patterns, involving limbic structures and prefrontal cortices, were also observed. The derangement of a right limbic network is associated with altered socio-emotional processing in bvFTD patients, but different hypometabolic FDG-PET patterns and heterogeneous performances on social tasks at an individual level exist.

In vivo PET imaging of the neuroinflammatory response in rat spinal cord injury using the TSPO tracer [18F]GE-180 and effect of docosahexaenoic acid

International Nuclear Information System (INIS)

Tremoleda, J.L.; Thau-Zuchman, O.; Davies, M.; Vadivelu, K.C.; Yip, P.K.; Michael-Titus, A.T.; Foster, J.; Sosabowski, J.; Khan, I.; Trigg, W.

2016-01-01

Traumatic spinal cord injury (SCI) is a devastating condition which affects millions of people worldwide causing major disability and substantial socioeconomic burden. There are currently no effective treatments. Modulating the neuroinflammatory (NI) response after SCI has evolved as a major therapeutic strategy. PET can be used to detect the upregulation of the 18-kDa translocator protein (TSPO), a hallmark of activated microglia in the CNS. We investigated whether PET imaging using the novel TSPO tracer [ 18 F]GE-180 can be used as a clinically relevant biomarker for NI in a contusion SCI rat model, and we present data on the modulation of NI by the lipid docosahexaenoic acid (DHA). A total of 22 adult male Wistar rats were subjected to controlled spinal cord contusion at the T10 spinal cord level. Six non-injured and ten T10 laminectomy only (LAM) animals were used as controls. A subset of six SCI animals were treated with a single intravenous dose of 250 nmol/kg DHA (SCI-DHA group) 30 min after injury; a saline-injected group of six animals was used as an injection control. PET and CT imaging was carried out 7 days after injury using the [ 18 F]GE-180 radiotracer. After imaging, the animals were killed and the spinal cord dissected out for biodistribution and autoradiography studies. In vivo data were correlated with ex vivo immunohistochemistry for TSPO. In vivo dynamic PET imaging revealed an increase in tracer uptake in the spinal cord of the SCI animals compared with the non-injured and LAM animals from 35 min after injection (P < 0.0001; SCI vs. LAM vs. non-injured). Biodistribution and autoradiography studies confirmed the high affinity and specific [ 18 F]GE-180 binding in the injured spinal cord compared with the binding in the control groups. Furthermore, they also showed decreased tracer uptake in the T10 SCI area in relation to the non-injured remainder of the spinal cord in the SCI-DHA group compared with the SCI-saline group (P < 0.05), supporting

Two anti-angiogenic TKI-PET tracers, [11C]axitinib and [11C]nintedanib: Radiosynthesis, in vivo metabolism and initial biodistribution studies in rodents

International Nuclear Information System (INIS)

Slobbe, Paul; Poot, Alex J.; Haumann, Rianne; Schuit, Robert C.; Windhorst, Albert D.; Dongen, Guus A.M.S. van

2016-01-01

Introduction: Tyrosine kinase inhibitors (TKIs) are very attractive targeted drugs, although a large portion of patients remains unresponsive. PET imaging with EGFR targeting TKIs ([ 11 C]erlotinib and [ 18 F]afatinib) showed promise in identifying treatment sensitive tumors. The aim of this study was to synthesize two anti-angiogenic TKI tracers, [ 11 C]axitinib and [ 11 C]nintedanib, and to evaluate their potential for PET. Methods: Following successful tracer synthesis, biodistribution studies in VU-SCC-OE and FaDu xenograft bearing mice were performed. Furthermore, tracer stability studies in mice were performed employing (radio-)HPLC and LC–MS/MS techniques. For [ 11 C]nintedanib an LC–MS/MS method was developed to detect the primary carboxylic acid metabolite, resulting from methylester cleavage, in plasma and tumors, because this metabolite is postulated to be important for nintedanib efficacy. LC–MS/MS was also explored to assess the metabolic fate of [ 11 C]axitinib in vivo, since axitinib has an isomerizable double bond. Results: [ 11 C]axitinib and [ 11 C]nintedanib were successfully synthesized with 10.5 ± 2.6% and 25.6 ± 3.3% radiochemical yield (corrected for decay), respectively. Biodistribution studies only demonstrated tumor uptake of [ 11 C]nintedanib in FaDu xenografts of 1.66 ± 0.02% ID/g at 60 min p.i. In vivo stability analysis of [ 11 C]axitinib at 45 min p.i. revealed the formation of predominantly non-polar metabolites (36.6 ± 6.8% vs 47.1 ± 8.4% of parent tracer and 16.3 ± 2.1% of polar metabolites), while for [ 11 C]nintedanib mostly polar metabolites were found (70.9 ± 4.1 vs 26.7 ± 3.9% of parent tracer and only 2.4 ± 1.6 of a non-polar metabolites). No isomerization of [ 11 C]axtinib was observed in vivo; however, a sulfoxide metabolite could be detected using LC–MS/MS. For [ 11 C]nintedanib, LC–MS/MS revealed formation of the reported primary carboxylic acid metabolite when in vitro plasma incubations were performed

Determination of tumour hypoxia with the PET tracer [18F]EF3: improvement of the tumour-to-background ratio in a mouse tumour model

International Nuclear Information System (INIS)

Christian, Nicolas; Bol, Anne; Bast, Marc de; Labar, Daniel; Lee, John; Mahy, Pierre; Gregoire, Vincent

2007-01-01

The 2-(2-nitroimidazol-1-yl)-N-(3,3,3-trifluoropropyl)acetamide (EF3) is a 2-nitroimidazole derivative which undergoes bioreductive activation under hypoxic conditions. Using the PET tracer [ 18 F]EF3 in mice, tumour-to-muscle ratios ranging from 1.3 to 3.5 were observed. This study investigated the impact of various interventions aimed at increasing [ 18 F]EF3 elimination, thus potentially increasing the tumour-to-noise ratio in mice, by increasing the renal filtration rate (spironolactone, furosemide), decreasing tubular re-absorption (metronidazole, ornidazole, amino acid solution) or stimulating gastro-intestinal elimination (phenobarbital). C3H mice were injected i.v. with an average of 12.95 MBq of [ 18 F]EF3. Drugs were injected i.v. 15 min before the tracer or daily 4 days prior to the experiment (phenobarbital). Anaesthetised mice were imaged from 30 to 300 min with a dedicated animal PET (Mosaic, Philips). Regions of interest were delineated around the tumour, bladder, heart, liver and leg muscle. Radioactivity was expressed as a percentage of injected activity per gram of tissue. Ornidazole decreased the urinary excretion and increased the liver uptake of [ 18 F]EF3, but without causing any changes in the other organs. Phenobarbital significantly increased the liver concentration and decreased radioactivity in blood and muscle without affecting the tracer uptake in tumour. Consequently, a small but non-significant increase in tumour-to-noise ratio was observed. Although some effects were observed with other drugs, they did not modify the tumour-to-noise ratio. Only phenobarbital induced a trend toward an increased tumour-to-noise ratio that could possibly be tested in the clinical situation. (orig.)

Florbetaben PET in the Early Diagnosis of Alzheimer's Disease: A Discrete Event Simulation to Explore Its Potential Value and Key Data Gaps

Science.gov (United States)

Guo, Shien; Getsios, Denis; Hernandez, Luis; Cho, Kelly; Lawler, Elizabeth; Altincatal, Arman; Lanes, Stephan; Blankenburg, Michael

2012-01-01

The growing understanding of the use of biomarkers in Alzheimer's disease (AD) may enable physicians to make more accurate and timely diagnoses. Florbetaben, a beta-amyloid tracer used with positron emission tomography (PET), is one of these diagnostic biomarkers. This analysis was undertaken to explore the potential value of florbetaben PET in the diagnosis of AD among patients with suspected dementia and to identify key data that are needed to further substantiate its value. A discrete event simulation was developed to conduct exploratory analyses from both US payer and societal perspectives. The model simulates the lifetime course of disease progression for individuals, evaluating the impact of their patient management from initial diagnostic work-up to final diagnosis. Model inputs were obtained from specific analyses of a large longitudinal dataset from the New England Veterans Healthcare System and supplemented with data from public data sources and assumptions. The analyses indicate that florbetaben PET has the potential to improve patient outcomes and reduce costs under certain scenarios. Key data on the use of florbetaben PET, such as its influence on time to confirmation of final diagnosis, treatment uptake, and treatment persistency, are unavailable and would be required to confirm its value. PMID:23326754

Florbetaben PET in the Early Diagnosis of Alzheimer's Disease: A Discrete Event Simulation to Explore Its Potential Value and Key Data Gaps

Directory of Open Access Journals (Sweden)

Shien Guo

2012-01-01

Full Text Available The growing understanding of the use of biomarkers in Alzheimer's disease (AD may enable physicians to make more accurate and timely diagnoses. Florbetaben, a beta-amyloid tracer used with positron emission tomography (PET, is one of these diagnostic biomarkers. This analysis was undertaken to explore the potential value of florbetaben PET in the diagnosis of AD among patients with suspected dementia and to identify key data that are needed to further substantiate its value. A discrete event simulation was developed to conduct exploratory analyses from both US payer and societal perspectives. The model simulates the lifetime course of disease progression for individuals, evaluating the impact of their patient management from initial diagnostic work-up to final diagnosis. Model inputs were obtained from specific analyses of a large longitudinal dataset from the New England Veterans Healthcare System and supplemented with data from public data sources and assumptions. The analyses indicate that florbetaben PET has the potential to improve patient outcomes and reduce costs under certain scenarios. Key data on the use of florbetaben PET, such as its influence on time to confirmation of final diagnosis, treatment uptake, and treatment persistency, are unavailable and would be required to confirm its value.

PET imaging of hepatocellular carcinoma with {sup 18}F-fluoroethylcholine and {sup 11}C-choline

Energy Technology Data Exchange (ETDEWEB)

Kolthammer, Jeffrey A.; Tenley, Nathan [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); Corn, David J.; Wu, Chunying; Tian, Haibin; Wang, Yanming [University Hospitals Case Medical Center, Nuclear Medicine Division, Department of Radiology, Cleveland, OH (United States); Lee, Zhenghong [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); University Hospitals Case Medical Center, Nuclear Medicine Division, Department of Radiology, Cleveland, OH (United States)

2011-07-15

Choline-based radiotracers have been studied for PET imaging of hepatocellular carcinoma (HCC). Using an {sup 18}F-labeled choline analog, instead of the {sup 11}C-labeled native choline, would facilitate its widespread use in the clinic. In this study, PET with {sup 18}F-fluoroethylcholine (FEC) and {sup 11}C-choline (CHOL) were compared using an animal model of HCC. The effects of fasting on the performance of choline-based tracers were also investigated. A woodchuck model of HCC was used to compare the two tracers, which were administered and imaged in sequence during the same imaging session. Dynamic PET images were generated spanning 50 min starting from tracer injection. Time-activity curves and tracer contrast were calculated in liver regions with tracer accumulation, and the contrast at a late time-point with the two tracers, and between fasted and nonfasted states, were compared. Foci of HCC with increased uptake ranged in size from 1.0 to 1.6 cm, with mean tumor-to-background contrast of 1.3 with FEC and 1.5 with CHOL at 50 min after injection. The tracers show similar patterns of uptake immediately following administration, and both activities plateaued at 10 min after injection. No significant differences in uptake dynamics or final contrast were observed between the fasted and nonfasted states. PET imaging of HCC is possible with both CHOL and FEC. Fasting was not found to affect accumulation of either tracer. These results encourage further investigation into the clinical utility of FEC for HCC imaging. (orig.)

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

Use of amyloid-PET to determine cutpoints for CSF markers

DEFF Research Database (Denmark)

Zwan, Marissa D; Rinne, Juha O; Hasselbalch, Steen G

2016-01-01

OBJECTIVES: To define CSF β-amyloid 1-42 (Aβ42) cutpoints to detect cortical amyloid deposition as assessed by 11C-Pittsburgh compound B ([11C]PiB)-PET and to compare these calculated cutpoints with cutpoints currently used in clinical practice. METHODS: We included 433 participants (57 controls......, 99 with mild cognitive impairment, 195 with Alzheimer disease [AD] dementia, and 82 with non-AD dementia) from 5 European centers. We calculated for each center and for the pooled cohort CSF Aβ42 and Aβ42/tau ratio cutpoints for cortical amyloid deposition based on visual interpretation of [11C......]PiB-PET images. RESULTS: Amyloid-PET-based calculated CSF Aβ42 cutpoints ranged from 521 to 616 pg/mL, whereas existing clinical-based cutpoints ranged from 400 to 550 pg/mL. Using the calculated cutpoint from the pooled sample (557 pg/mL), concordance between CSF Aβ42 and amyloid-PET was 84%. Similar...

Preliminary validation of varicella zoster virus thymidine kinase as a novel reporter gene for PET

International Nuclear Information System (INIS)

Deroose, Christophe M.; Chitneni, Satish K.; Gijsbers, Rik; Vermaelen, Peter; Ibrahimi, Abdelilah; Balzarini, Jan; Baekelandt, Veerle; Verbruggen, Alfons; Nuyts, Johan; Debyser, Zeger; Bormans, Guy M.

2012-01-01

Introduction: Imaging of gene expression with positron emission tomography (PET) has emerged as a powerful tool for biomedical research during the last decade. The prototypical herpes simplex virus type 1 thymidine kinase (HSV1-TK) PET reporter gene (PRG) is widely used and many other PRGs have also been validated. We investigated varicella zoster virus thymidine kinase (VZV-tk) as new PRG with radiolabeled bicyclic nucleoside analogues (BCNAs) as PET tracers. Methods: The uptake and washout of four different radiolabeled BCNAs was evaluated in cells expressing VZV-tk after lentiviral vector (LV) transduction and in control cells. Metabolism of the tracers was assayed by high pressure liquid chromatography (HPLC). Mice bearing VZV-TK expressing xenografts were imaged with PET. Results: High uptake in VZV-tk expressing cells was seen for 3 of the 4 tracers tested. The uptake of the tracers could be blocked by the presence of excess thymidine in the incubation solution. Cellular retention was variable, with one tracer showing an acceptable half-life of ∼ 1 hour. The amount of intracellular tracer correlated with the titer of LV used to transduce the cells. VZV-TK dependent conversion into metabolites was shown by HPLC. No specific accumulation was observed in cells expressing a fusion protein containing an HSV1-TK moiety. VZV-tk expression in xenografts resulted in a 60% increase in uptake in vivo as measured with PET. Conclusions: We have validated the combination of VZV-tk and radiolabeled BCNAs as new PRG/PRP system. Further optimization of the PRPs and the PRG are warranted to increase the signal.

Carbon-11 choline or FDG-PET for staging of oesophageal cancer?

International Nuclear Information System (INIS)

Jager, P.L.; Que, T.H.; Vaalburg, W.; Pruim, J.; Elsinga, P.; Plukker, J.T.

2001-01-01

We investigated the feasibility of using carbon-11 choline (CHOL) positron emission tomography (PET) for the staging of oesophageal cancer, in comparison with fluorine-18 fluorodeoxyglucose (FDG) PET, using histopathological findings as the gold standard. Eighteen patients were studied: 16 patients with cancer of the oesophagus or gastro-oesophageal junction and two with in situ carcinoma/high-grade dysplasia. PET imaging was performed 5 min (CHOL) or 90 min (FDG) after injection of 370 MBq of the tracer. PET images were analysed by two independent and blinded physicians using visual and standardised uptake value (SUV) analysis. PET results were compared with surgical and histopathological findings. FDG-PET was able to detect all (100%) of the 16 malignant primary lesions, while CHOL-PET detected 73%. In situ carcinoma (n=1) and high-grade dysplasia (n=1) were not visualised with either tracer. Diffuse uptake of the tracers was noted in areas of Barrett's oesophagitis. Twelve patients had locoregional metastases (N1) that were not detected with either FDG or CHOL. Six patients had additional distant nodal (M1a) metastases; four of six (66%) were visualised by FDG, and three of five (60%) by CHOL-PET. On a lesion basis, FDG-PET detected 10/12 non-regional metastases (sensitivity 83%), while CHOL-PET detected 5/12 (sensitivity 42%). Haematogenous distant metastases (M1b) were positive on FDG-PET in three of four patients, and on CHOL-PET in two of four. SUV values were significantly higher for FDG (FDG 6.6±3.5, CHOL 5.5±2.5, P=0.04). CHOL-PET is able to visualise oesophageal carcinoma and its metastases, but appears to be inferior to FDG-PET. Presumably this is the result of lower tumoural uptake and considerable non-specific uptake of CHOL in liver, stomach wall, pancreas and small intestine. Further studies are needed to confirm these data. (orig.)

Carbon-11 choline or FDG-PET for staging of oesophageal cancer?

Energy Technology Data Exchange (ETDEWEB)

Jager, P.L.; Que, T.H.; Vaalburg, W.; Pruim, J.; Elsinga, P. [PET Centre, Groningen Univ. Hospital (Netherlands); Plukker, J.T. [Dept. of Surgical Oncology, Groningen University Hospital (Netherlands)

2001-12-01

We investigated the feasibility of using carbon-11 choline (CHOL) positron emission tomography (PET) for the staging of oesophageal cancer, in comparison with fluorine-18 fluorodeoxyglucose (FDG) PET, using histopathological findings as the gold standard. Eighteen patients were studied: 16 patients with cancer of the oesophagus or gastro-oesophageal junction and two with in situ carcinoma/high-grade dysplasia. PET imaging was performed 5 min (CHOL) or 90 min (FDG) after injection of 370 MBq of the tracer. PET images were analysed by two independent and blinded physicians using visual and standardised uptake value (SUV) analysis. PET results were compared with surgical and histopathological findings. FDG-PET was able to detect all (100%) of the 16 malignant primary lesions, while CHOL-PET detected 73%. In situ carcinoma (n=1) and high-grade dysplasia (n=1) were not visualised with either tracer. Diffuse uptake of the tracers was noted in areas of Barrett's oesophagitis. Twelve patients had locoregional metastases (N1) that were not detected with either FDG or CHOL. Six patients had additional distant nodal (M1a) metastases; four of six (66%) were visualised by FDG, and three of five (60%) by CHOL-PET. On a lesion basis, FDG-PET detected 10/12 non-regional metastases (sensitivity 83%), while CHOL-PET detected 5/12 (sensitivity 42%). Haematogenous distant metastases (M1b) were positive on FDG-PET in three of four patients, and on CHOL-PET in two of four. SUV values were significantly higher for FDG (FDG 6.6{+-}3.5, CHOL 5.5{+-}2.5, P=0.04). CHOL-PET is able to visualise oesophageal carcinoma and its metastases, but appears to be inferior to FDG-PET. Presumably this is the result of lower tumoural uptake and considerable non-specific uptake of CHOL in liver, stomach wall, pancreas and small intestine. Further studies are needed to confirm these data. (orig.)

Integrated 18F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging (18F-FDG PET/MRI), a multimodality approach for comprehensive evaluation of dementia patients: A pictorial essay

International Nuclear Information System (INIS)

Jena, Amarnath; Renjen, Pushpendra Nath; Taneja, Sangeeta; Gambhir, Aashish; Negi, Pradeep

2015-01-01

Dementia, caused by irreversible neurodegenerative disorders such as Alzheimer's disease or reversible non-degenerative conditions, is rapidly becoming one of the most alarming health problems in our aging society. This cognitive disorder associated with a multitude of clinical differentials with overlapping clinical, pathological, and imaging features is difficult to diagnose and treat, as it often presents late after significant neuronal damage has already occurred. Novel disease-modifying treatments being developed will have to be corroborated with innovative imaging biomarkers so that earlier reliable diagnosis can be made and treatment initiated upon. Along with new specific PET radiotracers, integrated PET/MRI with combined methodological advantage and simultaneously acquired structural-cum-functional information may help achieve this goal. The present pictorial essay details our experiences with PET/MRI in dementing disorders, along with reviewing recent advances and future scope

Kinetic analysis of dynamic PET data

Energy Technology Data Exchange (ETDEWEB)

Knittel, B.

1983-12-01

Our goal is to quantify regional physiological processes such as blood flow and metabolism by means of tracer kinetic modeling and positron emission tomography (PET). Compartmental models are one way of characterizing the behavior of tracers in physiological systems. This paper describes a general method of estimating compartmental model rate constants from measurements of the concentration of tracers in blood and tissue, taken at multiple time intervals. A computer program which applies the method is described, and examples are shown for simulated and actual data acquired from the Donner 280-Crystal Positron Tomograph.

Kinetic analysis of dynamic PET data

International Nuclear Information System (INIS)

Knittel, B.

1983-12-01

Our goal is to quantify regional physiological processes such as blood flow and metabolism by means of tracer kinetic modeling and positron emission tomography (PET). Compartmental models are one way of characterizing the behavior of tracers in physiological systems. This paper describes a general method of estimating compartmental model rate constants from measurements of the concentration of tracers in blood and tissue, taken at multiple time intervals. A computer program which applies the method is described, and examples are shown for simulated and actual data acquired from the Donner 280-Crystal Positron Tomograph

Voxel-based analysis of cerebral glucose metabolism in AD and non-AD degenerative dementia using statistical parametric mapping

International Nuclear Information System (INIS)

Li Zugui; Gao Shuo; Zhang Benshu; Ma Aijun; Cai Li; Li Dacheng; Li Yansheng; Liu Lei

2008-01-01

Objective: It is know that Alzheimer's disease (AD) and non-AD degenerative dementia have some clinical features in common. The aim of this study was to investigate the specific patterns of regional, cerebral glucose metabolism of AD and non-AD degenerative dementia patients, using a voxel-based 18 F-fluorodeoxyglucose (FDG) PET study. Methods: Twenty-three AD patients and 24 non-AD degenerative dementia patients including 9 Parkinson's disease with dementia(PDD), 7 frontal-temporal dementia (FTD), 8 dementia of Lewy bodies (DLB) patients, and 40 normal controls (NC)were included in the study. To evaluate the relative cerebral metabolic rate of glucose (rCMRglc), 18 F-FDG PET imaging was performed in all subjects. Subsequently, statistical comparison of PET data with NC was performed using statistical parametric mapping (SPM). Results: The AD-associated FDG imaging pattern typically presented as focal cortical hypometabolism in bilateral parietotemporal association cortes and(or) frontal lobe and the posterior cingulate gyms. As compared with the comparative NC, FTD group demonstrated significant regional reductions in rCMRglc in bilateral frontal, parietal lobes, the cingulate gyri, insulae, left precuneus, and the subcortical structures (including right putamen, right medial dorsal nucleus and ventral anterior nucleus). The PDD group showed regional reductions in rCMRglc in bilateral frontal cortexes, parietotemporal association cortexes, and the subcortical structures (including left caudate, right putamen, the dorsomedial thalamus, lateral posterior nucleus, and pulvinar). By the voxel-by-voxel comparison between the DLB group and NC group, regional reductions in rCMRglc included bilateral occipital cortexes, precuneuses, frontal and parietal lobes, left anterior cingulate gyms, right superior temporal cortex, and the subcortical structures including putamen, caudate, lateral posterior nucleus, and pulvinar. Conclusions: The rCMRglc was found to be different

Kinetic Modelling of Infection Tracers [¹⁸F]FDG, [⁶⁸Ga]Ga-Citrate, [¹¹C]Methionine, and [¹¹C]Donepezil in a Porcine Osteomyelitis Model

DEFF Research Database (Denmark)

Jødal, Lars; Jensen, Svend Borup; Nielsen, Ole Lerberg

2017-01-01

Introduction. Positron emission tomography (PET) is increasingly applied for infection imaging using [18F]FDG as tracer, but uptake is unspecific. The present study compares the kinetics of [18F]FDG and three other PET tracers with relevance for infection imaging. Methods. A juvenile porcine...... osteomyelitis model was used. Eleven pigs underwent PET/CT with 60-minute dynamic PET imaging of [18F]FDG, [68Ga]Ga-citrate, [11C]methionine, and/or [11C]donepezil, along with blood sampling. For infectious lesions, kinetic modelling with one- and two-tissue-compartment models was conducted for each tracer...... for the analysis. Conclusions. The kinetics of the four studied tracers in infection was characterized. For clinical applications, [18F]FDG remains the first-choice PET tracer. [11C]methionine may have a potential for detecting soft tissue infections. [68Ga]Ga-citrate and [11C]donepezil were not found useful...

In vivo PET imaging of neuroinflammation in Alzheimer's disease.

Science.gov (United States)

Lagarde, Julien; Sarazin, Marie; Bottlaender, Michel

2018-05-01

Increasing evidence suggests that neuroinflammation contributes to the pathophysiology of many neurodegenerative diseases, especially Alzheimer's disease (AD). Molecular imaging by PET may be a useful tool to assess neuroinflammation in vivo, thus helping to decipher the complex role of inflammatory processes in the pathophysiology of neurodegenerative diseases and providing a potential means of monitoring the effect of new therapeutic approaches. For this objective, the main target of PET studies is the 18 kDa translocator protein (TSPO), as it is overexpressed by activated microglia. In the present review, we describe the most widely used PET tracers targeting the TSPO, the methodological issues in tracer quantification and summarize the results obtained by TSPO PET imaging in AD, as well as in neurodegenerative disorders associated with AD, in psychiatric disorders and ageing. We also briefly describe alternative PET targets and imaging modalities to study neuroinflammation. Lastly, we question the meaning of PET imaging data in the context of a highly complex and multifaceted role of neuroinflammation in neurodegenerative diseases. This overview leads to the conclusion that PET imaging of neuroinflammation is a promising way of deciphering the enigma of the pathophysiology of AD and of monitoring the effect of new therapies.

Determination of cerebral metabolic patterns in dementia using positron emission tomography

International Nuclear Information System (INIS)

Kuhl, D.E.

1986-01-01

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

Neurotransmission imaging by PET

International Nuclear Information System (INIS)

Takano, Akihiro; Suhara, Tetsuya

2001-01-01

examined. GABA has been predominantly studied by PET in epilepsy by using the GABA receptor tracer [ 11 C]flumazenil and there have been reports on [ 123 I]iomazenil SPECT in panic disorder. Abnormal GABA/benzodiazepine receptors have been hypothesized to be related to schizophrenia, although insufficient evidence has been accumulated to verify it. The acetylcholinesterase tracer [ 11 C]N-methyl-4-piperidyl acetate, has been used to investigate changes in acetylcholinesterase in Alzheimer's disease, and another study used [ 11 C]N-methyl-4-piperidylbenzilate to determine the relationship between muscarinic receptor occupancy by biperiden and its blood concentration. Because of the many disadvantages associated with [ 11 C]nicotine, a nicotinic acetylcholine receptor tracer, a more useful tracer needs to be developed. Glutamic acid is thought to be related to mental disorders. Two types of PET legands selective for NMDA receptor sub-units have been developed very recently. (K.H.)

Neuroimaging in dementia

Energy Technology Data Exchange (ETDEWEB)

Barkhof, Frederik [VU Univ. Medical Center, Amsterdam (NL). Dept. of Radiology and Image Analysis Center (IAC); Fox, Nick C. [UCL Institute of Neurology, London (United Kingdom). Dementia Research Centre; VU Univ. Medical Center, Amsterdam (Netherlands); Bastos-Leite, Antonio J. [Porto Univ. (Portugal). Dept. of Medical Imaging; Scheltens, Philip [VU Univ. Medical Center, Amsterdam (Netherlands). Dept. of Neurology and Alzheimer Center

2011-07-01

Against a background of an ever-increasing number of patients, new management options, and novel imaging modalities, neuroimaging is playing an increasingly important role in the diagnosis of dementia. This up-to-date, superbly illustrated book aims to provide a practical guide to the effective use of neuroimaging in the patient with cognitive decline. It sets out the key clinical and imaging features of the wide range of causes of dementia and directs the reader from clinical presentation to neuroimaging and on to an accurate diagnosis whenever possible. After an introductory chapter on the clinical background, the available ''toolbox'' of structural and functional neuroimaging techniques is reviewed in detail, including CT, MRI and advanced MR techniques, SPECT and PET, and image analysis methods. The imaging findings in normal ageing are then discussed, followed by a series of chapters that carefully present and analyze the key imaging findings in patients with dementias. A structured path of analysis follows the main presenting feature: disorders associated with primary gray matter loss, with white matter changes, with brain swelling, etc. Throughout, a practical approach is adopted, geared specifically to the needs of clinicians (neurologists, radiologists, psychiatrists, geriatricians) working in the field of dementia, for whom this book should prove an invaluable resource. (orig.)

Multi-technique hybrid imaging in PET/CT and PET/MR: what does the future hold?

International Nuclear Information System (INIS)

Galiza Barbosa, F. de; Delso, G.; Voert, E.E.G.W. ter; Huellner, M.W.; Herrmann, K.; Veit-Haibach, P.

2016-01-01

Integrated positron-emission tomography and computed tomography (PET/CT) is one of the most important imaging techniques to have emerged in oncological practice in the last decade. Hybrid imaging, in general, remains a rapidly growing field, not only in developing countries, but also in western industrialised healthcare systems. A great deal of technological development and research is focused on improving hybrid imaging technology further and introducing new techniques, e.g., integrated PET and magnetic resonance imaging (PET/MRI). Additionally, there are several new PET tracers on the horizon, which have the potential to broaden clinical applications in hybrid imaging for diagnosis as well as therapy. This article aims to highlight some of the major technical and clinical advances that are currently taking place in PET/CT and PET/MRI that will potentially maintain the position of hybrid techniques at the forefront of medical imaging technologies.

Separation of input function for rapid measurement of quantitative CMRO2 and CBF in a single PET scan with a dual tracer administration method

International Nuclear Information System (INIS)

Kudomi, Nobuyuki; Watabe, Hiroshi; Hayashi, Takuya; Iida, Hidehiro

2007-01-01

Cerebral metabolic rate of oxygen (CMRO 2 ), oxygen extraction fraction (OEF) and cerebral blood flow (CBF) images can be quantified using positron emission tomography (PET) by administrating 15 O-labelled water (H 15 2 O) and oxygen ( 15 O 2 ). Conventionally, those images are measured with separate scans for three tracers C 15 O for CBV, H 15 2 O for CBF and 15 O 2 for CMRO 2 , and there are additional waiting times between the scans in order to minimize the influence of the radioactivity from the previous tracers, which results in a relatively long study period. We have proposed a dual tracer autoradiographic (DARG) approach (Kudomi et al 2005), which enabled us to measure CBF, OEF and CMRO 2 rapidly by sequentially administrating H 15 2 O and 15 O 2 within a short time. Because quantitative CBF and CMRO 2 values are sensitive to arterial input function, it is necessary to obtain accurate input function and a drawback of this approach is to require separation of the measured arterial blood time-activity curve (TAC) into pure water and oxygen input functions under the existence of residual radioactivity from the first injected tracer. For this separation, frequent manual sampling was required. The present paper describes two calculation methods: namely a linear and a model-based method, to separate the measured arterial TAC into its water and oxygen components. In order to validate these methods, we first generated a blood TAC for the DARG approach by combining the water and oxygen input functions obtained in a series of PET studies on normal human subjects. The combined data were then separated into water and oxygen components by the present methods. CBF and CMRO 2 were calculated using those separated input functions and tissue TAC. The quantitative accuracy in the CBF and CMRO 2 values by the DARG approach did not exceed the acceptable range, i.e., errors in those values were within 5%, when the area under the curve in the input function of the second tracer

Limbic system, the main focus of dementia syndrome

International Nuclear Information System (INIS)

Matsuzawa, Taiju

1990-01-01

Alzheimer disease and multi-infarct dementia are two entirely different diseases producing almost the same abnormalities as dementia syndrome. The statistical studies with MRI to locate the focus of dementia syndrome in the neocortex was an absolute failure. With MRI there is drastic atrophy and destruction of the amygdala and hippocampus suggesting the limbic system as the focus of dementia syndrome. Destruction of the limbic system in particular amygdala and hippocampus produced the functional obstruction brought about by the marked reduction in the glucose utilization with PET in the bilateral temporal, parietal and occipital association cortices. Although this type constitutes only about 1/5 of all dementia patients. It is considered the fundamental type of dementia syndrome. Aside from this, there is a type wherein simultaneous and symmetrical reductions in glucose utilization of the frontal association cortex and the motor association cortex in the anterior part of the neocortex. This is referred to as type II. It constitutes about 4/5 of all dementia patients which is far more than type I. Based on these results, it is thought that limbic system is the main focus of dementia syndrome. (author)

Silicon Photomultipliers and Monolithic Scintillators for Time-of-Flight PET

NARCIS (Netherlands)

Seifert, S.

2012-01-01

Positron emission tomography (PET) is a nuclear medical imaging modality. Its aim is to visualize the 3-dimensional distribution of a radiopharmaceutical (also called the tracer) within a patient (clinical PET) or test-animal (in case of preclinical investigations). The information that can be

Comparison of PET/CT and PET/MRI hybrid systems using a 68Ga-labelled PSMA ligand for the diagnosis of recurrent prostate cancer: initial experience

International Nuclear Information System (INIS)

Afshar-Oromieh, A.; Haberkorn, U.; Schlemmer, H.P.; Fenchel, M.; Roethke, M.; Eder, M.; Eisenhut, M.; Hadaschik, B.A.; Kopp-Schneider, A.

2014-01-01

68 Ga-labelled HBED-CC-PSMA is a highly promising tracer for imaging recurrent prostate cancer (PCa). The intention of this study was to evaluate the feasibility of PET/MRI with this tracer. Twenty patients underwent PET/CT 1 h after injection of the 68 Ga-PSMA ligand followed by PET/MRI 3 h after injection. Data from the two investigations were first analysed separately and then compared with respect to tumour detection rate and radiotracer uptake in various tissues. To evaluate the quantification accuracy of the PET/MRI system, differences in SUVs between PET/CT and corresponding PET/MRI were compared with differences in SUVs between PET/CT 1 h and 3 h after injection in another patient cohort. This cohort was investigated using the same PET/CT system. With PET/MRI, different diagnostic sequences, higher contrast of lesions and higher resolution of MRI enabled a subjectively easier evaluation of the images. In addition, four unclear findings on PET/CT could be clarified as characteristic of PCa metastases by PET/MRI. However, in PET images of the PET/MRI, a reduced signal was observed at the level of the kidneys (in 11 patients) and around the urinary bladder (in 15 patients). This led to reduced SUVs in six lesions. SUV mean values provided by the PET/MRI system were different in muscles, blood pool, liver and spleen. PCa was detected more easily and more accurately with Ga-PSMA PET/MRI than with PET/CT and with lower radiation exposure. Consequently, this new technique could clarify unclear findings on PET/CT. However, scatter correction was challenging when the specific 68 Ga-PSMA ligand was used. Moreover, direct comparison of SUVs from PET/CT and PET/MR needs to be conducted carefully. (orig.)

Monte Carlo simulations of GeoPET experiments: 3D images of tracer distributions (18F, 124I and 58Co) in Opalinus clay, anhydrite and quartz

Science.gov (United States)

Zakhnini, Abdelhamid; Kulenkampff, Johannes; Sauerzapf, Sophie; Pietrzyk, Uwe; Lippmann-Pipke, Johanna

2013-08-01

Understanding conservative fluid flow and reactive tracer transport in soils and rock formations requires quantitative transport visualization methods in 3D+t. After a decade of research and development we established the GeoPET as a non-destructive method with unrivalled sensitivity and selectivity, with due spatial and temporal resolution by applying Positron Emission Tomography (PET), a nuclear medicine imaging method, to dense rock material. Requirements for reaching the physical limit of image resolution of nearly 1 mm are (a) a high-resolution PET-camera, like our ClearPET scanner (Raytest), and (b) appropriate correction methods for scatter and attenuation of 511 keV—photons in the dense geological material. The latter are by far more significant in dense geological material than in human and small animal body tissue (water). Here we present data from Monte Carlo simulations (MCS) reflecting selected GeoPET experiments. The MCS consider all involved nuclear physical processes of the measurement with the ClearPET-system and allow us to quantify the sensitivity of the method and the scatter fractions in geological media as function of material (quartz, Opalinus clay and anhydrite compared to water), PET isotope (18F, 58Co and 124I), and geometric system parameters. The synthetic data sets obtained by MCS are the basis for detailed performance assessment studies allowing for image quality improvements. A scatter correction method is applied exemplarily by subtracting projections of simulated scattered coincidences from experimental data sets prior to image reconstruction with an iterative reconstruction process.

Fluorine-18 labeled tracers for PET studies in the neurosciences

Energy Technology Data Exchange (ETDEWEB)

Ding, Yu-Shin; Fowler, J.S.

1995-12-31

This chapter focuses on fluorine-18, the positron emitter with the longest half-life, the lowest positron energy and probably, the most challenging chemistry. The incorporation of F-18 into organic compounds presents many challenges, including: the need to synthesize and purify the compound within a 2--3 hour time frame; the limited number of labeled precursor molecules; the need to work on a microscale; and the need to produce radiotracers which are chemically and radiochemically pure, sterile and pyrogen-free, and suitable for intravenous injection. The PET method and F-18 labeling of organic molecules are described followed by highlights of the applications of F-18 labeled compounds in the neurosciences and neuropharmacology. It is important to emphasize the essential and pivotal role that organic synthesis has played in the progression of the PET field over the past twenty years from one in which only a handful of institutions possessed the instrumentation and staff to carry out research to the present-day situation where there are more than 200 PET centers worldwide. During this period PET has become an important scientific tool in the neurosciences, cardiology and oncology. It is important to point out that PET is by no means a mature field. The fact that a hundreds of different F-18 labeled compounds have been developed but only a few possess the necessary selectivity and sensitivity in vivo to track a specific biochemical process illustrates this and underscores a major difficulty in radiotracer development, namely the selection of priority structures for synthesis and the complexities of the interactions between chemical compounds and living systems. New developments in rapid organic synthesis are needed in order to investigate new molecular targets and to improve the quantitative nature of PET experiments.

Fluorine-18 labeled tracers for PET studies in the neurosciences

International Nuclear Information System (INIS)

Ding, Yu-Shin; Fowler, J.S.

1995-01-01

This chapter focuses on fluorine-18, the positron emitter with the longest half-life, the lowest positron energy and probably, the most challenging chemistry. The incorporation of F-18 into organic compounds presents many challenges, including: the need to synthesize and purify the compound within a 2--3 hour time frame; the limited number of labeled precursor molecules; the need to work on a microscale; and the need to produce radiotracers which are chemically and radiochemically pure, sterile and pyrogen-free, and suitable for intravenous injection. The PET method and F-18 labeling of organic molecules are described followed by highlights of the applications of F-18 labeled compounds in the neurosciences and neuropharmacology. It is important to emphasize the essential and pivotal role that organic synthesis has played in the progression of the PET field over the past twenty years from one in which only a handful of institutions possessed the instrumentation and staff to carry out research to the present-day situation where there are more than 200 PET centers worldwide. During this period PET has become an important scientific tool in the neurosciences, cardiology and oncology. It is important to point out that PET is by no means a mature field. The fact that a hundreds of different F-18 labeled compounds have been developed but only a few possess the necessary selectivity and sensitivity in vivo to track a specific biochemical process illustrates this and underscores a major difficulty in radiotracer development, namely the selection of priority structures for synthesis and the complexities of the interactions between chemical compounds and living systems. New developments in rapid organic synthesis are needed in order to investigate new molecular targets and to improve the quantitative nature of PET experiments

Positron emission tomography (PET) in psychiatry

International Nuclear Information System (INIS)

Herholz, K.

1993-01-01

Currently, clinical PET is mainly useful in psychiatry and related areas for differential diagnosis of dementia. In dementia of Alzheimer type reductions of glucose metabolism are found mainly in the temporoparietal assocaiton cortex, in Pick's disease mainly in the frontal cortex, and in Huntington's disease in the striatum. Other demential diseases usually show less toposelective metabolic impairment. In the future, new diagnostic possibilities may arise from analysis of functional stimulation of specific brain areas and from the use of ligands for specific neurotransmitter systems. (orig.) [de

Imaging with PET system

International Nuclear Information System (INIS)

Das, B.K.; Noreen Norfaraheen Lee Abdullah

2012-01-01

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

False Positive Uptake in Bilateral Gynecomastia on 68Ga-PSMA PET/CT Scan.

Science.gov (United States)

Sasikumar, Arun; Joy, Ajith; Nair, Bindu P; Pillai, M R A; Madhavan, Jayaprakash

2017-09-01

A 66-year-old man on hormonal therapy with prostate cancer was referred for Ga-PSMA PET/CT scan for biochemical recurrence. Ga-PSMA PET/CT scan detected moderate heterogeneous tracer concentration in bilateral breast parenchyma, in addition to the abnormal tracer concentration in enlarged prostate gland, right external iliac lymph node, and sclerotic lesion in L4 vertebra. On clinical examination, he was found to have bilateral gynecomastia. Abnormal concentration of Ga-PSMA in breast cancer is now well known, and in this context, it is important to know that tracer localization can occur in gynecomastia as well, as evidenced in this case.

Comparison of PET/CT and PET/MRI hybrid systems using a {sup 68}Ga-labelled PSMA ligand for the diagnosis of recurrent prostate cancer: initial experience

Energy Technology Data Exchange (ETDEWEB)

Afshar-Oromieh, A. [University Hospital Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); German Cancer Research Center (DKFZ), Department of Radiology, Heidelberg (Germany); Haberkorn, U. [University Hospital Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); German Cancer Research Center (DKFZ), Clinical Cooperation Unit of Nuclear Medicine, Heidelberg (Germany); Schlemmer, H.P.; Fenchel, M.; Roethke, M. [German Cancer Research Center (DKFZ), Department of Radiology, Heidelberg (Germany); Eder, M.; Eisenhut, M. [German Cancer Research Center (DKFZ), Department of Radiopharmaceutical Chemistry, Heidelberg (Germany); Hadaschik, B.A. [University Hospital Heidelberg, Department of Urology, Heidelberg (Germany); Kopp-Schneider, A. [German Cancer Research Center (DKFZ), Department of Biostatistics, Heidelberg (Germany)

2014-05-15

{sup 68}Ga-labelled HBED-CC-PSMA is a highly promising tracer for imaging recurrent prostate cancer (PCa). The intention of this study was to evaluate the feasibility of PET/MRI with this tracer. Twenty patients underwent PET/CT 1 h after injection of the {sup 68}Ga-PSMA ligand followed by PET/MRI 3 h after injection. Data from the two investigations were first analysed separately and then compared with respect to tumour detection rate and radiotracer uptake in various tissues. To evaluate the quantification accuracy of the PET/MRI system, differences in SUVs between PET/CT and corresponding PET/MRI were compared with differences in SUVs between PET/CT 1 h and 3 h after injection in another patient cohort. This cohort was investigated using the same PET/CT system. With PET/MRI, different diagnostic sequences, higher contrast of lesions and higher resolution of MRI enabled a subjectively easier evaluation of the images. In addition, four unclear findings on PET/CT could be clarified as characteristic of PCa metastases by PET/MRI. However, in PET images of the PET/MRI, a reduced signal was observed at the level of the kidneys (in 11 patients) and around the urinary bladder (in 15 patients). This led to reduced SUVs in six lesions. SUV{sub mean} values provided by the PET/MRI system were different in muscles, blood pool, liver and spleen. PCa was detected more easily and more accurately with Ga-PSMA PET/MRI than with PET/CT and with lower radiation exposure. Consequently, this new technique could clarify unclear findings on PET/CT. However, scatter correction was challenging when the specific {sup 68}Ga-PSMA ligand was used. Moreover, direct comparison of SUVs from PET/CT and PET/MR needs to be conducted carefully. (orig.)

TH-E-202-00: PET for Radiation Therapy

International Nuclear Information System (INIS)

2016-01-01

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss: Pitfalls and remedies in PET/CT imaging for RT planning The use of hypoxia PET imaging for radiotherapy PET for tumor response evaluation The first presentation will address the issue of mis-registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image-guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de-escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi-quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non-FDG PET tracers for response assessment. Learning Objectives: Identify the causes of mis-registration of CT and PET images in PET/CT, and review the strategies to remedy the issue. Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo-radiation therapy). Understand the basics of dynamic PET imaging, compartmental modeling and parametric images. Understand the

TH-E-202-00: PET for Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

NONE

2016-06-15

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss: Pitfalls and remedies in PET/CT imaging for RT planning The use of hypoxia PET imaging for radiotherapy PET for tumor response evaluation The first presentation will address the issue of mis-registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image-guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de-escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi-quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non-FDG PET tracers for response assessment. Learning Objectives: Identify the causes of mis-registration of CT and PET images in PET/CT, and review the strategies to remedy the issue. Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo-radiation therapy). Understand the basics of dynamic PET imaging, compartmental modeling and parametric images. Understand the

Determination of tumour hypoxia with the PET tracer [{sup 18}F]EF3: improvement of the tumour-to-background ratio in a mouse tumour model

Energy Technology Data Exchange (ETDEWEB)

Christian, Nicolas; Bol, Anne; Bast, Marc de; Labar, Daniel; Lee, John; Mahy, Pierre; Gregoire, Vincent [Universite Catholique de Louvain, Center for Molecular Imaging and Experimental Radiotherapy, Brussels (Belgium)

2007-09-15

The 2-(2-nitroimidazol-1-yl)-N-(3,3,3-trifluoropropyl)acetamide (EF3) is a 2-nitroimidazole derivative which undergoes bioreductive activation under hypoxic conditions. Using the PET tracer [{sup 18}F]EF3 in mice, tumour-to-muscle ratios ranging from 1.3 to 3.5 were observed. This study investigated the impact of various interventions aimed at increasing [{sup 18}F]EF3 elimination, thus potentially increasing the tumour-to-noise ratio in mice, by increasing the renal filtration rate (spironolactone, furosemide), decreasing tubular re-absorption (metronidazole, ornidazole, amino acid solution) or stimulating gastro-intestinal elimination (phenobarbital). C3H mice were injected i.v. with an average of 12.95 MBq of [{sup 18}F]EF3. Drugs were injected i.v. 15 min before the tracer or daily 4 days prior to the experiment (phenobarbital). Anaesthetised mice were imaged from 30 to 300 min with a dedicated animal PET (Mosaic, Philips). Regions of interest were delineated around the tumour, bladder, heart, liver and leg muscle. Radioactivity was expressed as a percentage of injected activity per gram of tissue. Ornidazole decreased the urinary excretion and increased the liver uptake of [{sup 18}F]EF3, but without causing any changes in the other organs. Phenobarbital significantly increased the liver concentration and decreased radioactivity in blood and muscle without affecting the tracer uptake in tumour. Consequently, a small but non-significant increase in tumour-to-noise ratio was observed. Although some effects were observed with other drugs, they did not modify the tumour-to-noise ratio. Only phenobarbital induced a trend toward an increased tumour-to-noise ratio that could possibly be tested in the clinical situation. (orig.)

Neurotransmission imaging by PET

Energy Technology Data Exchange (ETDEWEB)

Takano, Akihiro; Suhara, Tetsuya [National Inst. of Radiological Sciences, Chiba (Japan)

2001-08-01

been developed, and serotonin transporters have recently begun to be examined. GABA has been predominantly studied by PET in epilepsy by using the GABA receptor tracer [{sup 11}C]flumazenil and there have been reports on [{sup 123}I]iomazenil SPECT in panic disorder. Abnormal GABA/benzodiazepine receptors have been hypothesized to be related to schizophrenia, although insufficient evidence has been accumulated to verify it. The acetylcholinesterase tracer [{sup 11}C]N-methyl-4-piperidyl acetate, has been used to investigate changes in acetylcholinesterase in Alzheimer's disease, and another study used [{sup 11}C]N-methyl-4-piperidylbenzilate to determine the relationship between muscarinic receptor occupancy by biperiden and its blood concentration. Because of the many disadvantages associated with [{sup 11}C]nicotine, a nicotinic acetylcholine receptor tracer, a more useful tracer needs to be developed. Glutamic acid is thought to be related to mental disorders. Two types of PET legands selective for NMDA receptor sub-units have been developed very recently. (K.H.)

Direct reconstruction of parametric images for brain PET with event-by-event motion correction: evaluation in two tracers across count levels

Science.gov (United States)

Germino, Mary; Gallezot, Jean-Dominque; Yan, Jianhua; Carson, Richard E.

2017-07-01

Parametric images for dynamic positron emission tomography (PET) are typically generated by an indirect method, i.e. reconstructing a time series of emission images, then fitting a kinetic model to each voxel time activity curve. Alternatively, ‘direct reconstruction’, incorporates the kinetic model into the reconstruction algorithm itself, directly producing parametric images from projection data. Direct reconstruction has been shown to achieve parametric images with lower standard error than the indirect method. Here, we present direct reconstruction for brain PET using event-by-event motion correction of list-mode data, applied to two tracers. Event-by-event motion correction was implemented for direct reconstruction in the Parametric Motion-compensation OSEM List-mode Algorithm for Resolution-recovery reconstruction. The direct implementation was tested on simulated and human datasets with tracers [11C]AFM (serotonin transporter) and [11C]UCB-J (synaptic density), which follow the 1-tissue compartment model. Rigid head motion was tracked with the Vicra system. Parametric images of K 1 and distribution volume (V T  =  K 1/k 2) were compared to those generated by the indirect method by regional coefficient of variation (CoV). Performance across count levels was assessed using sub-sampled datasets. For simulated and real datasets at high counts, the two methods estimated K 1 and V T with comparable accuracy. At lower count levels, the direct method was substantially more robust to outliers than the indirect method. Compared to the indirect method, direct reconstruction reduced regional K 1 CoV by 35-48% (simulated dataset), 39-43% ([11C]AFM dataset) and 30-36% ([11C]UCB-J dataset) across count levels (averaged over regions at matched iteration); V T CoV was reduced by 51-58%, 54-60% and 30-46%, respectively. Motion correction played an important role in the dataset with larger motion: correction increased regional V T by 51% on average in the [11C

SPECT og PET i neurobiologien

DEFF Research Database (Denmark)

Paulson, O.B.; Lassen, N.A.

1997-01-01

PET (positron emission tomography) and SPECT (single photon emission computed tomography) are isotopic methods in which the distribution is registered of radiolabelled tracers given in such small amounts that they are without effect on the organism or the organism's disposal of them. Thus, a series...

Discovering EEG resting state alterations of semantic dementia.

Science.gov (United States)

Grieder, Matthias; Koenig, Thomas; Kinoshita, Toshihiko; Utsunomiya, Keita; Wahlund, Lars-Olof; Dierks, Thomas; Nishida, Keiichiro

2016-05-01

Diagnosis of semantic dementia relies on cost-intensive MRI or PET, although resting EEG markers of other dementias have been reported. Yet the view still holds that resting EEG in patients with semantic dementia is normal. However, studies using increasingly sophisticated EEG analysis methods have demonstrated that slightest alterations of functional brain states can be detected. We analyzed the common four resting EEG microstates (A, B, C, and D) of 8 patients with semantic dementia in comparison with 8 healthy controls and 8 patients with Alzheimer's disease. Topographical differences between the groups were found in microstate classes B and C, while microstate classes A and D were comparable. The data showed that the semantic dementia group had a peculiar microstate E, but the commonly found microstate C was lacking. Furthermore, the presence of microstate E was significantly correlated with lower MMSE and language scores. Alterations in resting EEG can be found in semantic dementia. Topographical shifts in microstate C might be related to semantic memory deficits. This is the first study that discovered resting state EEG abnormality in semantic dementia. The notion that resting EEG in this dementia subtype is normal has to be revised. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

The establishment of the Rossendorf PET Center

International Nuclear Information System (INIS)

Johannsen, B.; Steinbach, J.

1993-01-01

The objectives of the newly established Positron Emission Tomography (PET) Center at the Institut of Bioinorganic and Radiopharmaceutical Chemistry in Rossendorf are described, referring to medical research, development of tracers and radiochemicals developments, biochemistry and future prospects of PET in Rossendorf. The layout of the center is also described considering the cyclotron and targetry, the transport system, the radiopharmaceutical laboratories and the tomograph. A schedule for project development is going. (BBR)

Hypoxia positron emission tomography imaging: combining information on perfusion and tracer retention to improve hypoxia specificity

DEFF Research Database (Denmark)

Busk, Morten; Munk, Ole L; Jakobsen, Steen S

2017-01-01

BACKGROUND: Static positron emission tomography (PET) allows mapping of tumor hypoxia, but low resolution and slow tracer retention/clearance results in poor image contrast and the risk of missing areas where hypoxic cells and necrosis are intermixed. Fully dynamic PET may improve accuracy but scan...

Follicular thyroid cancer avid on C-11 Methionine PET/CT

OpenAIRE

Jochumsen, Mads Ryø; Iversen, Peter; Arveschoug, Anne Kirstine

2018-01-01

Summary A case of follicular thyroid cancer with intense focal Methionine uptake on 11C-Methionine PET/CT is reported here. The use of 11C-Methionine PET in differentiated thyroid cancer is currently being investigated as a surrogate tracer compared to the more widely used 18F-FDG PET. This case illustrates the potential incremental value of this modality, not only in the localizing of parathyroid adenoma, but also indicating that 11C-Methionine PET might have a potential of increasing the pr...

SPECT perfusion brain scintigraphy in dementia: early diagnostic and differential diagnostic

International Nuclear Information System (INIS)

Klisarova, A.

2003-01-01

The present review discusses the role of Single Photon Emission Computer Tomography (SPECT) and Positron Emission Tomography (PET) for the early detection and the differential diagnosis of the different types of dementia. The usefulness of the functional imaging is particularly emphasized in the detection of the early changes occurring in Alzheimer's diseases. The early diagnosis is a crucial factor for the treatment in the phase of reversible changes. The correlation between the severity of the diseases and the degree of hypoperfusion of the functional neuroimaging is also subject to review. SPECT and PET are of particular importance for the differential diagnosis of the various kinds of dementia. The imaging models are defined for the different stages of diseases. The functional imaging together with the clinical tests increase the diagnostic accuracy in Alzheimer's disease. The review presents the relation between the development of Alzheimer's disease and some risk factors. The review confirms the usefulness of SPECT and PET in the early diagnosis of Alzheimer's disease and the differential diagnosis of the different types of dementia which proves the SPECT appropriateness in the routine clinical practice. The brain structures are more advantageous than the other methods of visualisation (CT and MRI) for the detection of the functional disorders in the brain cortex in a number of diseases of the central nervous system. (author)

Monitoring of anti-cancer treatment with (18)F-FDG and (18)F-FLT PET

DEFF Research Database (Denmark)

Jensen, Mette Munk; Kjaer, Andreas

2015-01-01

treatment effect early in a treatment course and by that to stratify patients into responders and non-responders. With 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) and 3'-deoxy-3'-[(18)F]fluorothymidine((18)F-FLT) two of the cancer hallmarks, altered energy metabolism and increased cell proliferation, can......Functional imaging of solid tumors with positron emission tomography (PET) imaging is an evolving field with continuous development of new PET tracers and discovery of new applications for already implemented PET tracers. During treatment of cancer patients, a general challenge is to measure...... be visualized and quantified non-invasively by PET. With (18)F-FDG and (18)F-FLT PET changes in energy metabolism and cell proliferation can thereby be determined after initiation of cancer treatment in both clinical and pre-clinical studies in order to predict, at an early time-point, treatment response...

Development of a New Positron Emission Tomography Tracer for Targeting Tumor Angiogenesis: Synthesis, Small Animal Imaging, and Radiation Dosimetry

Directory of Open Access Journals (Sweden)

David S. Lalush

2013-05-01

Full Text Available Angiogenesis plays a key role in cancer progression and correlates with disease aggressiveness and poor clinical outcomes. Affinity ligands discovered by screening phage display random peptide libraries can be engineered to molecularly target tumor blood vessels for noninvasive imaging and early detection of tumor aggressiveness. In this study, we tested the ability of a phage-display-selected peptide sequence recognizing specifically bone marrow- derived pro-angiogenic tumor-homing cells, the QFP-peptide, radiolabeled with 64Cu radioisotope to selectively image tumor vasculature in vivo by positron emission tomography (PET. To prepare the targeted PET tracer we modified QFP-phage with the DOTA chelator and radiolabeled the purified QFP-phage-DOTA intermediate with 64Cu to obtain QFP-targeted radioconjugate with high radiopharmaceutical yield and specific activity. We evaluated the new PET tracer in vivo in a subcutaneous (s.c. Lewis lung carcinoma (LLC mouse model and conducted tissue distribution, small animal PET/CT imaging study, autoradiography, histology, fluorescence imaging, and dosimetry assessments. The results from this study show that, in the context of the s.c. LLC immunocompetent mouse model, the QFP-tracer can target tumor blood vessels selectively. However, further optimization of the biodistribution and dosimetry profile of the tracer is necessary to ensure efficient radiopharmaceutical applications enabled by the biological specificity of the QFP-peptide.

TH-E-202-03: PET for Tumor Response Evaluation

International Nuclear Information System (INIS)

Lu, W.

2016-01-01

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss: Pitfalls and remedies in PET/CT imaging for RT planning The use of hypoxia PET imaging for radiotherapy PET for tumor response evaluation The first presentation will address the issue of mis-registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image-guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de-escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi-quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non-FDG PET tracers for response assessment. Learning Objectives: Identify the causes of mis-registration of CT and PET images in PET/CT, and review the strategies to remedy the issue. Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo-radiation therapy). Understand the basics of dynamic PET imaging, compartmental modeling and parametric images. Understand the

TH-E-202-03: PET for Tumor Response Evaluation

Energy Technology Data Exchange (ETDEWEB)

Lu, W. [University of Maryland School of Medicine (United States)

2016-06-15

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss: Pitfalls and remedies in PET/CT imaging for RT planning The use of hypoxia PET imaging for radiotherapy PET for tumor response evaluation The first presentation will address the issue of mis-registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image-guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de-escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi-quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non-FDG PET tracers for response assessment. Learning Objectives: Identify the causes of mis-registration of CT and PET images in PET/CT, and review the strategies to remedy the issue. Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo-radiation therapy). Understand the basics of dynamic PET imaging, compartmental modeling and parametric images. Understand the

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,

Clinical and imaging correlates of amyloid deposition in dementia with Lewy bodies.

Science.gov (United States)

Donaghy, Paul C; Firbank, Michael J; Thomas, Alan J; Lloyd, Jim; Petrides, George; Barnett, Nicola; Olsen, Kirsty; O'Brien, John T

2018-04-19

Amyloid deposition is common in dementia with Lewy bodies, but its pathophysiological significance is unclear. The objective of this study was to investigate the relationship between amyloid deposition and clinical profile, gray matter volume, and brain perfusion in dementia with Lewy bodies. Dementia with Lewy bodies (n = 37), Alzheimer's disease (n = 20), and controls (n = 20) underwent a thorough clinical assessment, 3T MRI, and early- and late-phase 18 F-Florbetapir PET-CT to assess cortical perfusion and amyloid deposition, respectively. Amyloid scans were visually categorized as positive or negative. Image analysis was carried out using statistical parametric mapping (SPM) 8. There were no significant differences between amyloid-positive and amyloid-negative dementia with Lewy bodies cases in age (P = .78), overall cognitive impairment (P = .83), level of functional impairment (P = .80), or any other clinical or cognitive scale. There were also no significant differences in hippocampal or gray matter volumes. However, amyloid-positive dementia with Lewy bodies cases had lower medial temporal lobe perfusion (P = .03) than amyloid-negative cases, although a combination of medial temporal lobe perfusion, hippocampal volume, and cognitive measures was unable to accurately predict amyloid status in dementia with Lewy bodies. Amyloid deposition was not associated with differences in clinical or neuropsychological profiles in dementia with Lewy bodies, but was associated with imaging evidence of medial temporal lobe dysfunction. The presence of amyloid in dementia with Lewy bodies cannot be identified on the basis of clinical and other imaging features and will require direct assessment via PET imaging or CSF. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf

Comparison of dosimetry between PET/CT and PET alone using 11C-ITMM

International Nuclear Information System (INIS)

Ito, Kimiteru; Sakata, Muneyuki; Wagarsuma, Kei; Toyohara, Jun; Ishibashi, Kenji; Ishii, Kenji; Ishiwata, Kiichi; Oda, Keiichi

2016-01-01

We used a new tracer, N-[4-[6-(isopropylamino) pyrimidin-4-yl]-1,3-thiazol-2-yl]-4- 11 C-methoxy-N-methylbenzamide ( 11 C-ITMM), to compare radiation doses from positron emission tomography (PET)/computed tomography (CT) with previously published doses from PET alone. Twelve healthy volunteers [six males (mean age ± SD, 27.7 ± 6.7 years) and six females (31.8 ± 14.5 years)] in 12 examinations were recruited. Dose estimations from PET/CT were compared with those from PET alone. Regions of interest (ROIs) in PET/CT were delineated on the basis of low-dose CT (LD-CT) images acquired during PET/CT. Internal and external radiation doses were estimated using OLINDA/EXM 1.0 and CT-Expo software. The effective dose (ED) for 11 C-ITMM calculated from PET/CT was estimated to be 4.7 ± 0.5 μSv/MBq for the male subjects and 4.1 ± 0.7 μSv/MBq for the female subjects. The mean ED for 11 C-ITMM calculated from PET alone in a previous report was estimated to be 4.6 ± 0.3 μSv/MBq (males, n = 3). The ED values for 11 C-ITMM calculated from PET/CT in the male subjects were almost identical to those from PET alone. The absorbed doses (ADs) of the gallbladder, stomach, red bone marrow, and spleen calculated from PET/CT were significantly different from those calculated from PET alone. The EDs of 11 C-ITMM calculated from PET/CT were almost identical to those calculated from PET alone. The ADs in several organs calculated from PET/CT differed from those from PET alone. LD-CT images acquired during PET/CT may facilitate organ identification.

Dementia syndrome and the onset of mind

International Nuclear Information System (INIS)

Matsuzawa, Taiju; Meguro, Kenichi; Ueda, Masamichi; Matsui, Hiroshige

1988-01-01

The present report is designed to make clear the mechanism of dementia syndrome and the onset area of the mind. The plan of the statistic studies with X-CT, MRI and PET to find out the focus of dementia in the cortex was an absolute failure. A large number of patients having infarction of varying numbers and sizes in the cortex was neuropsychologically normal. With MRI, quantitative changes of atrophy and destruction were observed in the amygdaloid and hippocampal system bilaterally in both multiinfarct dementia (MID) and Alzheimer disease (AD) patients. With PET, the activity or excitability of the cortices was estimated by measuring the glucose utilization with 18 F-2-fluorodeoxyglucose in response to musical stimulation (a Japanese popular song entitled Sakura, Sakura=cherry blossoms, cherry blossoms) while having the eyes closed, (1) Not only normal volunteers but also with cases of MID and AD, the primary sensory and motor areas were stimulated. (2) In cases of MID and AD, the glucose utilization, was reduced drastically in the bilateral temporal and parietal association cortices. The impulses from all the primary sensory areas drain into the amygdala. Furthermore the impulses from the amygdala drain directly or indirectly into the hippocampus, and the impulses flow into the temporal cortex. Recognition may take place in this temporal cortex. Then, the impulses come to the parietal cortex. Conception may be completed there. Any damage to the amygdaloid and hippocampal system would result in abnormalities in memory, recognition, conception and various emotions. This is a possible mechanism of dementia syndrome. In view of this data the system also can be said to be the onset area of the mind. (author)

Dementia syndrome and the onset of mind

Energy Technology Data Exchange (ETDEWEB)

Matsuzawa, Taiju; Meguro, Kenichi; Ueda, Masamichi; Matsui, Hiroshige

1988-12-01

The present report is designed to make clear the mechanism of dementia syndrome and the onset area of the mind. The plan of the statistic studies with X-CT, MRI and PET to find out the focus of dementia in the cortex was an absolute failure. A large number of patients having infarction of varying numbers and sizes in the cortex was neuropsychologically normal. With MRI, quantitative changes of atrophy and destruction were observed in the amygdaloid and hippocampal system bilaterally in both multiinfarct dementia (MID) and Alzheimer disease (AD) patients. With PET, the activity or excitability of the cortices was estimated by measuring the glucose utilization with /sup 18/F-2-fluorodeoxyglucose in response to musical stimulation (a Japanese popular song entitled Sakura, Sakura=cherry blossoms, cherry blossoms) while having the eyes closed, (1) Not only normal volunteers but also with cases of MID and AD, the primary sensory and motor areas were stimulated. (2) In cases of MID and AD, the glucose utilization, was reduced drastically in the bilateral temporal and parietal association cortices. The impulses from all the primary sensory areas drain into the amygdala. Furthermore the impulses from the amygdala drain directly or indirectly into the hippocampus, and the impulses flow into the temporal cortex. Recognition may take place in this temporal cortex. Then, the impulses come to the parietal cortex. Conception may be completed there. Any damage to the amygdaloid and hippocampal system would result in abnormalities in memory, recognition, conception and various emotions. This is a possible mechanism of dementia syndrome. In view of this data the system also can be said to be the onset area of the mind. (author).

Multi-atlas attenuation correction supports full quantification of static and dynamic brain PET data in PET-MR

Science.gov (United States)

Mérida, Inés; Reilhac, Anthonin; Redouté, Jérôme; Heckemann, Rolf A.; Costes, Nicolas; Hammers, Alexander

2017-04-01

In simultaneous PET-MR, attenuation maps are not directly available. Essential for absolute radioactivity quantification, they need to be derived from MR or PET data to correct for gamma photon attenuation by the imaged object. We evaluate a multi-atlas attenuation correction method for brain imaging (MaxProb) on static [18F]FDG PET and, for the first time, on dynamic PET, using the serotoninergic tracer [18F]MPPF. A database of 40 MR/CT image pairs (atlases) was used. The MaxProb method synthesises subject-specific pseudo-CTs by registering each atlas to the target subject space. Atlas CT intensities are then fused via label propagation and majority voting. Here, we compared these pseudo-CTs with the real CTs in a leave-one-out design, contrasting the MaxProb approach with a simplified single-atlas method (SingleAtlas). We evaluated the impact of pseudo-CT accuracy on reconstructed PET images, compared to PET data reconstructed with real CT, at the regional and voxel levels for the following: radioactivity images; time-activity curves; and kinetic parameters (non-displaceable binding potential, BPND). On static [18F]FDG, the mean bias for MaxProb ranged between 0 and 1% for 73 out of 84 regions assessed, and exceptionally peaked at 2.5% for only one region. Statistical parametric map analysis of MaxProb-corrected PET data showed significant differences in less than 0.02% of the brain volume, whereas SingleAtlas-corrected data showed significant differences in 20% of the brain volume. On dynamic [18F]MPPF, most regional errors on BPND ranged from -1 to  +3% (maximum bias 5%) for the MaxProb method. With SingleAtlas, errors were larger and had higher variability in most regions. PET quantification bias increased over the duration of the dynamic scan for SingleAtlas, but not for MaxProb. We show that this effect is due to the interaction of the spatial tracer-distribution heterogeneity variation over time with the degree of accuracy of the attenuation maps. This

Episodic Memory Dysfunction in Behavioral Variant Frontotemporal Dementia: A Clinical And FDG-PET Study.

Science.gov (United States)

Fernández-Matarrubia, Marta; Matías-Guiu, Jordi A; Cabrera-Martín, María Nieves; Moreno-Ramos, Teresa; Valles-Salgado, María; Carreras, José Luis; Matías-Guiu, Jorge

2017-01-01

Episodic memory disturbance is still considered as an exclusion criterion for behavioral variant frontotemporal dementia (bvFTD), but growing evidence suggests that memory can be impaired. Our main purposes were to assess episodic memory in a group of bvFTD patients comparatively with Alzheimer's disease (AD) patients, and analyze the relationship between episodic memory and brain metabolism measured using positron emission tomography imaging with 18F-fluorodeoxyglucose (FDG-PET). Twenty-six bvFTD, 29 AD, and 24 healthy controls were included. Episodic memory was assessed by the Free and Cued Selective Reminding Test (FCSRT), which controls for effective encoding and measures memory consolidation processing. All participants underwent FDG-PET brain scans to provide data for voxel-based brain mapping analysis. Half of bvFTD patients had a deficit of total, free delayed, and total free delayed recall as severe as AD patients (amnestic-FTD). The other half had FCSRT scores similar to controls (non-amnestic-FTD). Imaging analyses revealed that amnestic-FTD showed bilateral lower metabolism than non-amnestic-FTD in anterior parahippocampal and inferior temporal gyri. Additionally, FCSRT total and total delayed scores were inversely correlated with parahippocampal metabolism in both bvFTD and AD. Besides, bvFTD showed an inverse association among FCSRT and inferior temporal metabolism. Our findings support that bvFTD could present a genuine amnesia affecting storage and consolidation abilities, which involves structures implicated in the Papez circuit, as occurs in AD, and also inferior temporal regions. These results contribute to understanding the mechanisms underpinning memory dysfunction in bvFTD, and may be relevant to further revisions of the current diagnostic criteria.

Impact of contamination with long-lived radionuclides on PET kinetics modelling in multitracer studies

DEFF Research Database (Denmark)

Jødal, Lars; Hansen, Søren Baarsgaard; Jensen, Svend B

2016-01-01

Introduction: An important issue in multitracer studies is the separation of signals from the different radiotracers. This is especially the case when an early tracer has a long physical half-life and kinetic modelling has to be performed, because the early tracer can confer a long-lived contamin......Introduction: An important issue in multitracer studies is the separation of signals from the different radiotracers. This is especially the case when an early tracer has a long physical half-life and kinetic modelling has to be performed, because the early tracer can confer a long...... of subsequent PET tracers. Blood sample counts were corrected by recounting the samples a few days later. A more optimal choice of energy window was also explored. The effect of correction versus noncorrection was investigated using a two-tissue kinetic model with irreversible uptake (K1, k2, k3). Results: K1...... counting of blood samples can lead to a contaminating background not observed in PET imaging and this background can affect kinetic modelling. If the contaminating tracer has a much longer half-life than the foreground tracer, then the problem can be solved by late recounting of the samples....

Preliminary evaluation of a brain PET insertable to MRI

International Nuclear Information System (INIS)

Cho, Gyuseng; Choi, Yong; Lee, Jae Sung; An, Hyun Joon; Jung, Jin Ho; Park, Hyun Wook; Oh, Chang Hyun; Park, Kyeongjin; Lim, Kyung Taek; Cho, Minsik; Sul, Woo Suk; Kim, Hyoungtaek; Kim, Hyunduk

2014-01-01

There is a new trend of the medical image that diagnoses a brain disease as like Alzheimer dementia. The first qualified candidate is a PET-MRI fusion modality because MRI is a more powerful anatomic diagnosis tool than other modalities. In our study, in order to solve the high magnetic field from MRI, the development was consisted with four main items such as photo-sensor, PET scanner, MRI head-coil and attenuation correction algorithm development.

Preliminary evaluation of a brain PET insertable to MRI

Energy Technology Data Exchange (ETDEWEB)

Cho, Gyuseng [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 South (Korea, Republic of); Choi, Yong [Department of Electronic Engineering, Sogang University, Seoul, 121-742 South (Korea, Republic of); Lee, Jae Sung; An, Hyun Joon [Department of Nuclear Medicine, Seoul National University, Seoul, 110-744 South (Korea, Republic of); Jung, Jin Ho [Department of Electronic Engineering, Sogang University, Seoul, 121-742 South (Korea, Republic of); Park, Hyun Wook; Oh, Chang Hyun; Park, Kyeongjin; Lim, Kyung Taek; Cho, Minsik [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 South (Korea, Republic of); Sul, Woo Suk [National NanoFab Center, Deajeon, 305-806 South (Korea, Republic of); Kim, Hyoungtaek; Kim, Hyunduk [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 South (Korea, Republic of)

2014-07-29

There is a new trend of the medical image that diagnoses a brain disease as like Alzheimer dementia. The first qualified candidate is a PET-MRI fusion modality because MRI is a more powerful anatomic diagnosis tool than other modalities. In our study, in order to solve the high magnetic field from MRI, the development was consisted with four main items such as photo-sensor, PET scanner, MRI head-coil and attenuation correction algorithm development.

PET for molecular imaging of cancer: a tool for tailored therapy

International Nuclear Information System (INIS)

Kjaer, Andreas

2014-01-01

The concept of personalised medicine has led to a need for improved phenotyping as well as prediction of treatment response early after therapy initiation. Most of the molecular biology methods used today need tissue sampling for in vitro analysis. In contrast, molecular imaging allows for non-invasive studies at the molecular level in living, intact organisms. Accordingly, molecular imaging with PET has been one of the most successful techniques in such phenotyping and response prediction using FDG. In addition, recent development of new PET tracers has further improved the value of PET in tumor characterization. Such new PET tracers allow for visualization of tumor specific receptors and tissue characteristics such as ability to metastasize. Furthermore, PET has a high sensitivity and allows for quantification and is not prone to sampling error as seen with biopsies. We will present examples of development of probes targeting the somatostatin receptor type 2, over-expressed in neuroendocrine tumors, including our first-in-man studies of 64 Cu-DOTATATE. Also development in probes for visualization of the invasive phenotype will be presented. Finally, with the most recent development of true integrated PET/MRI scanners has now become possible to add information from MRI. The value of such hybrid imaging will also be briefly discussed. (author)

PET for molecular imaging of cancer: a tool for tailored therapy

International Nuclear Information System (INIS)

Kjaer, Andreas

2013-01-01

The concept of personalised medicine has led to a need for improved phenotyping as well as prediction of treatment response early after therapy initiation. Most of the molecular biology methods used today need tissue sampling for in vitro analysis. In contrast, molecular imaging allows for non-invasive studies at the molecular level in living, intact organisms. Accordingly, molecular imaging with PET has been one of the most successful techniques in such phenotyping and response prediction using FDG. In addition, recent development of new PET tracers has further improved the value of PET in tumor characterization. Such new PET tracers allow for visualization of tumor specific receptors and tissue characteristics such as ability to metastasize. Furthermore, PET has a high sensitivity and allows for quantification and is not prone to sampling error as seen with biopsies. We will present examples of development of probes targeting the somatostatin receptor type 2, over-expressed in neuroendocrine tumors, including our first-in-man studies of 64Cu-DOTATATE. Also development in probes for visualization of the invasive phenotype will be presented. Finally, with the most recent development of true integrated PET/MRI scanners it has now become possible to add information from MRI. The value of such hybrid imaging will also be briefly discussed. (author)

Fundamentals of quantitative PET data analysis

NARCIS (Netherlands)

Willemsen, ATM; van den Hoff, J

2002-01-01

Drug analysis and development with PET should fully exhaust the ability of this tomographic technique to quantify regional tracer concentrations in vivo. Data evaluation based on visual inspection or assessment of regional image contrast is not sufficient for this purpose since much of the

Radiosynthesis and evaluation of 11C-CIMBI-5 as a 5-HT2A receptor agonist radioligand for PET

DEFF Research Database (Denmark)

Ettrup, Anders; Palner, Mikael; Gillings, Nic

2010-01-01

PET brain imaging of the serotonin 2A (5-hydroxytryptamine 2A, or 5-HT(2A)) receptor has been widely used in clinical studies, and currently, several well-validated radiolabeled antagonist tracers are used for in vivo imaging of the cerebral 5-HT(2A) receptor. Access to 5-HT(2A) receptor agonist...... PET tracers would, however, enable imaging of the active, high-affinity state of receptors, which may provide a more meaningful assessment of membrane-bound receptors. In this study, we radiolabel the high-affinity 5-HT(2A) receptor agonist 2-(4-iodo-2,5-dimethoxyphenyl)-N-(2-[(11)C-OCH(3......)]methoxybenzyl)ethanamine ((11)C-CIMBI-5) and investigate its potential as a PET tracer....

Usefulness of Choline-PET for the detection of residual hemangiopericytoma in the skull base: comparison with FDG-PET

Directory of Open Access Journals (Sweden)

Ito Shin

2012-02-01

Full Text Available Abstract Background Choline is a new PET tracer that is useful for the detection of malignant tumor. Choline is a precursor of the biosynthesis of phosphatidylcholine, a major phospholipid in the cell membrane of eukaryotic cells. Malignant tumors have an elevated level of phosphatidylcholine in cell membrane. Thus, choline is a marker of tumor malignancy. Method The patient was a 51-year-old man with repeated recurrent hemangiopericytoma in the skull base. We performed Choline-PET in this patient after various treatments and compared findings with those of FDG-PET. Results Choline accumulated in this tumor, but FDG did not accumulate. We diagnosed this tumor as residual hemangiopericytoma and performed the resection of the residual tumor. FDG-PET is not appropriate for skull base tumor detection because uptake in the brain is very strong. Conclusion We emphasize the usefulness of Choline-PET for the detection of residual hemangiopericytoma in the skull base after various treatments, compared with FDG-PET.

Diagnostic performance of {sup 18}F-fluorothymidine PET/CT for primary colorectal cancer and its lymph node metastasis: comparison with {sup 18}F-fluorodeoxyglucose PET/CT

Energy Technology Data Exchange (ETDEWEB)

Nakajo, Masatoyo [Kagoshima University, Graduate School of Medical and Dental Sciences, Department of Radiology, Kagoshima (Japan); Nanpuh Hospital, Department of Radiology, Kagoshima (Japan); Nakajo, Masayuki; Jinguji, Megumi; Fukukura, Yoshihiko [Kagoshima University, Graduate School of Medical and Dental Sciences, Department of Radiology, Kagoshima (Japan); Kajiya, Yoriko; Tani, Atushi [Nanpuh Hospital, Department of Radiology, Kagoshima (Japan); Nishimata, Nobuaki; Shimaoka, Shunji; Nihara, Tohru [Nanpuh Hospital, Department of Gastroenterology, Kagoshima (Japan); Aridome, Kuniaki [Nanpuh Hospital, Department of Surgery, Kagoshima (Japan); Tanaka, Sadao [Nanpuh Hospital, Department of Pathology, Kagoshima (Japan); Koriyama, Chihaya [Kagoshima University, Graduate School of Medical and Dental Sciences, Department of Epidemiology and Preventive Medicine, Kagoshima (Japan)

2013-08-15

To examine the diagnostic performance of {sup 18}F-fluorothymidine (FLT) PET/CT in primary and metastatic lymph node colorectal cancer foci in comparison with {sup 18}F-fluorodeoxyglucose (FDG) PET/CT. The study population comprised 28 patients with 30 newly diagnosed colorectal cancers who underwent surgical resection of the primary lesion and regional lymph nodes after both FLT and FDG PET/CT. The associations between SUVmax levels and pathological factors were evaluated using the Mann-Whitney U or Kruskal-Wallis test. Differences in diagnostic indexes for detecting nodal metastasis between the two tracers were estimated using the McNemar exact or {chi} {sup 2} test. All 30 primary cancers (43.0 {+-} 20.0 mm, range 14 - 85 mm) were visualized by both tracers, but none of the FLT SUVmax values exceeded the FDG SUVmax values in any of the primary cancers (6.6 {+-} 2.4 vs. 13.6 {+-} 5.8, p < 0.001). The sensitivity, specificity and accuracy for detecting nodal metastasis were 41 % (15/37), 98.8 % (493/499) and 94.8 % (508/536) for FDG PET/CT, and 32 % (12/37), 98.8 % (493/499) and 94.2 % (505/536) for FLT PET/CT, respectively. The sensitivity (p = 0.45), specificity (p = 0.68) and accuracy (p = 0.58) were not different between the tracers. Nodal uptake of FLT and FDG was discordant in 7 (19 %) of 37 metastatic nodes. There were ten concordant true-positive nodes of which six showed higher FDG SUVmax and four showed higher FLT SUVmax, but the difference between FDG and FLT SUVmax was not significant (5.56 {+-} 3.55 and 3.62 {+-} 1.45, respectively; p = 0.22). FLT has the same potential as FDG in PET/CT for the diagnosis of primary and nodal foci of colorectal cancer despite significantly lower FLT uptake in primary foci. (orig.)

Multiparametric PET imaging in thyroid malignancy characterizing tumour heterogeneity: somatostatin receptors and glucose metabolism

Energy Technology Data Exchange (ETDEWEB)

Traub-Weidinger, Tatjana [Medical University of Vienna, Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Medical University of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Putzer, Daniel; Bale, Reto [Medical University of Innsbruck, Department of Radiology, Innsbruck (Austria); Guggenberg, Elisabeth von; Dobrozemsky, Georg; Nilica, Bernhard; Kendler, Dorota; Virgolini, Irene Johanna [Medical University of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria)

2015-12-15

Radiolabelled somatostatin (SST) analogues have proven useful in diagnosing tumours positive for SST receptor (SSTR). As different subtypes of SSTR are expressed on the tumour cell surface, the choice of appropriate therapeutic SST analogue is crucial. We evaluated the SSTR status of thyroid cancer patients who had signs of progressive disease comparing different SSTR ligands for PET imaging to evaluate possible further therapeutic options. PET with {sup 68}Ga-radiolabelled SSTR ligands DOTA lanreotide (DOTA-LAN), DOTA-Tyr{sup 3} octreotide (DOTA-TOC) and {sup 18}F-FDG was performed in 31 patients with thyroid cancer (TC). These 31 patients comprised 18 with radioiodine non-avid differentiated TC (DTC) including 6 papillary TC (PTC), 8 follicular TC (FTC) and 4 oxyphilic TC (oxyTC), 5 with anaplastic TC (ATC), and 8 with medullary TC (MTC). The PET results were compared in a region-based evaluation. All patients underwent a PET study with {sup 68}Ga-DOTA-LAN, 28 patients with {sup 68}Ga-DOTA-TOC and 28 patients with {sup 18}F-FDG. A lack of SSTR expression was found in 13 of the 31 patients (42 %) with negative results with both SSTR tracers in 12 patients. Ambiguous results with both SSTR tracers were observed in one patient. High tracer uptake in SSTR PET images was seen in seven DTC patients (39 %; two PTC, three FTC, two oxyTC), in four ATC patients (80 %) and in six MTC patients (75 %). Lesions showing aerobic glycolysis on {sup 18}F-FDG PET were found in 24 of 28 patients (86 %) with corresponding positive results with {sup 68}Ga-DOTA-LAN in 35 % and with {sup 68}Ga-DOTA-TOC in 29 %. The heterogeneous SSTR profile of TC tumour lesions needs to be evaluated using different SSTR PET tracers to characterize more closely the SSTR subtype affinities in patients with progressive TC in order to further stratify therapy with SSTR therapeutics. (orig.)

Early dynamic imaging in 68Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions.

Science.gov (United States)

Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Fritz, Josef; Warwitz, Boris; Scarpa, Lorenza; Roig, Llanos Geraldo; Kendler, Dorota; von Guggenberg, Elisabeth; Bektic, Jasmin; Horninger, Wolfgang; Virgolini, Irene Johanna

2017-05-01

PET/CT with 68 Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic 68 Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. Eighty consecutive PC patients referred to 68 Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUV max of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic 68 Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suv max was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p dynamic imaging in 68 Ga-PSMA-11 PET/CT reliably enables the differentiation of pathologic tracer uptake in PC lesions from physiologic bladder accumulation. Performance of early dynamic imaging in addition to whole body imaging 60 min after tracer injection might improve the detection rate

WE-AB-204-03: A Novel 3D Printed Phantom for 4D PET/CT Imaging and SIB Radiotherapy Verification

International Nuclear Information System (INIS)

Soultan, D; Murphy, J; Moiseenko, V; Cervino, L; Gill, B

2015-01-01

Purpose: To construct and test a 3D printed phantom designed to mimic variable PET tracer uptake seen in lung tumor volumes. To assess segmentation accuracy of sub-volumes of the phantom following 4D PET/CT scanning with ideal and patient-specific respiratory motion. To plan, deliver and verify delivery of PET-driven, gated, simultaneous integrated boost (SIB) radiotherapy plans. Methods: A set of phantoms and inserts were designed and manufactured for a realistic representation of lung cancer gated radiotherapy steps from 4D PET/CT scanning to dose delivery. A cylindrical phantom (40x 120 mm) holds inserts for PET/CT scanning. The novel 3D printed insert dedicated to 4D PET/CT mimics high PET tracer uptake in the core and lower uptake in the periphery. This insert is a variable density porous cylinder (22.12×70 mm), ABS-P430 thermoplastic, 3D printed by uPrint SE Plus with inner void volume (5.5×42 mm). The square pores (1.8×1.8 mm2 each) fill 50% of outer volume, resulting in a 2:1 SUV ratio of PET-tracer in the void volume with respect to porous volume. A matching in size cylindrical phantom is dedicated to validate gated radiotherapy. It contains eight peripheral holes matching the location of the porous part of the 3D printed insert, and one central hole. These holes accommodate adaptors for Farmer-type ion chamber and cells vials. Results: End-to-end test were performed from 4D PET/CT scanning to transferring data to the planning system and target volume delineation. 4D PET/CT scans were acquired of the phantom with different respiratory motion patterns and gating windows. A measured 2:1 18F-FDG SUV ratio between inner void and outer volume matched the 3D printed design. Conclusion: The novel 3D printed phantom mimics variable PET tracer uptake typical of tumors. Obtained 4D PET/CT scans are suitable for segmentation, treatment planning and delivery in SIB gated treatments of NSCLC

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.

Differentiation of dementia with lewy bodies from Alzheimer's disease using FDG PET and I-123-fluoropropyl-β-CIT SPECT

International Nuclear Information System (INIS)

Park, Eun Kyung; Cho, Sang Soo; Lee, Jae Sung; Kim, Jung Eun; Kim, Sang Yun; Lee, Won Woo; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul; Kim, Sang Eun

2004-01-01

Dementia with Lewy bodies (DLB) shares clinical and pathological features with Alzheimer's disease (AD) and Parkinson's disease. The differentiation of DLB from these disorders poses difficulties. We compared regional cerebral metabolic impairment and dopaminergic neuronal integrity between patients with DLB and AD using FDG PET and I-123-fluoropropyl-β-CIT (FP-CIT) SPECT, respectively, as measures for differential diagnosis. Fourteen clinically diagnosed DLB patients, 15 probable AD patients, and 12 age- and gender-matched healthy controls were studied with FDG PET and FP-CIT SPECT. A voxel-wise comparison of PET images was performed using SPM99. A dopamine transporter (DAT) parameter V3 was calculated in striatal regions as (striatal VOIcerebellar VOI)/cerebellar VOI activity on SPECT images obtained 3 h after injection of 185 MBq FP-CIT. SPM analysis of PET images of DLB revealed hypometabolism bilaterally in the occipital cortices, lateral occipitotemporal gyri, cunei, caudate, and Thalami compared with controls, most pronounced in the occipital cortex compared with AD. In DLB, V3 in the caudate (1.07±0.55) and putamen (1.01±0.34) was significantly (P < 0.001) lower than in AD (2.73±0.75 and 3.17±0.88, respectively) and controls (3.00±0.45 and 3.11±0.31, respectively). There was no significant difference in striatal V3 between AD and controls. The ratio of putamen-to-caudate V3 was not significantly different between DLB (1.04±0.32) and controls (1.05±0.12), indicating that DATs in the caudate and putamen are evenly affected in DLB. In DLB, there was a significant correlation between striatal V3 and MMSE score (rho=0.97, P<0.01). These data demonstrate different biochemical features between DLB and AD, in terms of regional brain metabolism and dopaminergic neuronal integrity. Measures of the glucose metabolism in the occipital cortex and the striatal DAT density may be informative diagnostic aids to distinguish DLB from AD

Follicular thyroid cancer avid on C-11 Methionine PET/CT

Directory of Open Access Journals (Sweden)

Mads Ryø Jochumsen

2018-01-01

Full Text Available A case of follicular thyroid cancer with intense focal Methionine uptake on 11C-Methionine PET/CT is reported here. The use of 11C-Methionine PET in differentiated thyroid cancer is currently being investigated as a surrogate tracer compared to the more widely used 18F-FDG PET. This case illustrates the potential incremental value of this modality, not only in the localizing of parathyroid adenoma, but also indicating that 11C-Methionine PET might have a potential of increasing the pretest likelihood of thyroid malignancy in a cold nodule with highly increased Sestamibi uptake.

Laboratory and cyclotron requirements for PET research

International Nuclear Information System (INIS)

Schlyer, D.J.

1993-01-01

The requirements for carrying out PET research can vary widely depending on the type of basic research being carried out and the extent of a clinical program at a particular center. The type of accelerator and laboratory facilities will, of course, depend on the exact mix. These centers have been divided into four categories. 1. Clinical PET with no radionuclide production facilities, 2. clinical PET with some radionuclide production facilities, 3. clinical PET with research support, and 4. a PET research facility developing new tracers and exploring clinical applications. Guidelines for the choice of an accelerator based on these categories and the practical yields of the common nuclear reactions for production of PET isotopes have been developed and are detailed. Guidelines as to the size and physical layout of the laboratory space necessary for the synthesis of various radiopharmaceuticals have also been developed and are presented. Important utility and air flow considerations are explored

FDG-PET in the clinical management of Hodgkin lymphoma

DEFF Research Database (Denmark)

Hutchings, Martin; Eigtved, Annika I; Specht, Lena

2004-01-01

Positron emission tomography (PET) is a molecular functional imaging technique that provides qualitative and quantitative information about the localization and activity of pathophysiological processes. The most commonly used tracer for oncological purposes is 2-[18F]fluoro-2-deoxy-d-glucose (FDG......). FDG-PET has within recent years become the most important nuclear medicine imaging modality in the management of lymphoma. This review summarizes the data published so far concerning the value of FDG-PET in staging, treatment monitoring, therapy planning, and follow-up of Hodgkin lymphoma (HL). FDG...

A quality system for PET: An industry perspective

International Nuclear Information System (INIS)

Zigler, Steven S.; Breslow, Kenneth; Nazerias, Michael

2005-01-01

Quality systems have been employed in a variety of industries to develop and supply products that meet customer expectations and regulatory requirements. Most quality systems address organizational structure, design controls, production, complaints, audits, corrective actions and preventive actions. This paper describes PETNET's efforts to develop a quality system for use in the production of PET tracers. Our goal is to ensure quality products and to facilitate compliance with impending PET good manufacturing practice (GMP) regulations

Early dynamic imaging in {sup 68}Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions

Energy Technology Data Exchange (ETDEWEB)

Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Warwitz, Boris; Scarpa, Lorenza; Roig, Llanos Geraldo; Kendler, Dorota; Guggenberg, Elisabeth von; Virgolini, Irene Johanna [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Fritz, Josef [Medical University Innsbruck, Department for Medical Statistics, Informatics and Health Economics, Innsbruck (Austria); Bektic, Jasmin; Horninger, Wolfgang [Medical University Innsbruck, Department of Urology, Innsbruck (Austria)

2017-05-15

PET/CT with {sup 68}Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic {sup 68}Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. Eighty consecutive PC patients referred to {sup 68}Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUV{sub max} of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic {sup 68}Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suv{sub max} was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p < 0.001). In the subgroup of PC patients with biochemical relapse the detection rate of local recurrence could be increased from 20.3 to 29.7%. Early dynamic imaging in {sup 68}Ga-PSMA-11 PET/CT reliably enables the differentiation of pathologic tracer uptake in PC lesions from physiologic

Early dynamic imaging in "6"8Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions

International Nuclear Information System (INIS)

Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Warwitz, Boris; Scarpa, Lorenza; Roig, Llanos Geraldo; Kendler, Dorota; Guggenberg, Elisabeth von; Virgolini, Irene Johanna; Fritz, Josef; Bektic, Jasmin; Horninger, Wolfgang

2017-01-01

PET/CT with "6"8Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic "6"8Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. Eighty consecutive PC patients referred to "6"8Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUV_m_a_x of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic "6"8Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suv_m_a_x was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p < 0.001). In the subgroup of PC patients with biochemical relapse the detection rate of local recurrence could be increased from 20.3 to 29.7%. Early dynamic imaging in "6"8Ga-PSMA-11 PET/CT reliably enables the differentiation of pathologic tracer uptake in PC lesions from physiologic bladder accumulation

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

DEFF Research Database (Denmark)

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

2012-01-01

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

Semiautomated analysis of small-animal PET data.

Science.gov (United States)

Kesner, Adam L; Dahlbom, Magnus; Huang, Sung-Cheng; Hsueh, Wei-Ann; Pio, Betty S; Czernin, Johannes; Kreissl, Michael; Wu, Hsiao-Ming; Silverman, Daniel H S

2006-07-01

The objective of the work reported here was to develop and test automated methods to calculate biodistribution of PET tracers using small-animal PET images. After developing software that uses visually distinguishable organs and other landmarks on a scan to semiautomatically coregister a digital mouse phantom with a small-animal PET scan, we elastically transformed the phantom to conform to those landmarks in 9 simulated scans and in 18 actual PET scans acquired of 9 mice. Tracer concentrations were automatically calculated in 22 regions of interest (ROIs) reflecting the whole body and 21 individual organs. To assess the accuracy of this approach, we compared the software-measured activities in the ROIs of simulated PET scans with the known activities, and we compared the software-measured activities in the ROIs of real PET scans both with manually established ROI activities in original scan data and with actual radioactivity content in immediately harvested tissues of imaged animals. PET/atlas coregistrations were successfully generated with minimal end-user input, allowing rapid quantification of 22 separate tissue ROIs. The simulated scan analysis found the method to be robust with respect to the overall size and shape of individual animal scans, with average activity values for all organs tested falling within the range of 98% +/- 3% of the organ activity measured in the unstretched phantom scan. Standardized uptake values (SUVs) measured from actual PET scans using this semiautomated method correlated reasonably well with radioactivity content measured in harvested organs (median r = 0.94) and compared favorably with conventional SUV correlations with harvested organ data (median r = 0.825). A semiautomated analytic approach involving coregistration of scan-derived images with atlas-type images can be used in small-animal whole-body radiotracer studies to estimate radioactivity concentrations in organs. This approach is rapid and less labor intensive than are

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...... 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. METHODS AND RESULTS: Forty-eight patients were randomized to adenosine or dipyridamole cardiac...... 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...

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

International Nuclear Information System (INIS)

Khayum, M.A.; Doorduin, J.; Antunes, I.F.; Kwizera, C.; Zijlma, R.; Boer, J.A. den; Dierckx, R.A.J.O.; Vries, E.F.J. de

2015-01-01

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

Development of fluorine 18 labelled MPPF, radiopharmaceutical tracer for serotoninergic system exploration

International Nuclear Information System (INIS)

Le Bars, D.; Tochon-Danguy, H.

2002-01-01

Full text: Positron Emission Tomography (PET) is a non-invasive method for exploration, in man and animals, of metabolism with radiopharmaceutical tracers labelled with positron emitters such as carbon 11 and fluorine 18 obtained with a cyclotron. Among the ever increasing number of tracers focussed at the CNS neurotransmission, the discovery of a new family of serotoninergic 5HT 1A antagonists (WAY 100635) has led to the first in vivo imaging of 5HT 1A receptors in man, located in cerebral structures such as cortex and hippocampus. Exploration of serotonine parthway is particulaly interesting in normal or diseased state, as this neurotransmitter is involved in the control of mood, sleep and is probably altered in psychiatric disorders. CERMEP, in collaboration with other PET centres has developped a new 5HT 1A antagonist, MPPF, labelled with fluorine 18. [ 18 F]MPPF has the advantadge of fluorine 18 labelling, with a longer half-life (110 min vs 20 min for carbon 11) and easier radiosynthesis automation. Moreover, MPPF affinity for 5HT 1A is close to serotonin itself, thus enabling displacement of MPPF by endogenous serotonin during pharmacological challenges. Automated radiosynthesis of MPPF is achieved via a classical [ 18 F]F - fluoro for nitro displacement, activated by a catalyst, on a nitro precursor prepared in four steps. A final HPLC purification ensures the production of [ 18 F]MPPF with a high purity and a high specific activity. Ex vivo autoradiographies and PET studies in animals (rat, cat) have shown the excellent specificity of MPPF for the 5HT 1A receptor. Experiments with intracerebral β probe have evidenced the displacement of [ 18 F]MPPF by endogenous serotonin after fenfluramine injection. [ 18 F]MPPF is now used in man for non-invasive PET studies of serotoninergic system. Normal volunteers matched for age and sex have been screened as a database and to compute a mathematical model of the tracer kinetic describing 5HT 1A receptor affinity and

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 DOTA-NOC PET-CT is superior to F-FDG PET-CT only for lymph node metastases (P DOTA-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.

WE-H-207A-06: Hypoxia Quantification in Static PET Images: The Signal in the Noise

International Nuclear Information System (INIS)

Keller, H; Yeung, I; Milosevic, M; Jaffray, D; Kueng, R; Shek, T; Driscoll, B

2016-01-01

Purpose: Quantification of hypoxia from PET images is of considerable clinical interest. In the absence of dynamic PET imaging the hypoxic fraction (HF) of a tumor has to be estimated from voxel values of activity concentration of a radioactive hypoxia tracer. This work is part of an effort to standardize quantification of tumor hypoxic fraction from PET images. Methods: A simple hypoxia imaging model in the tumor was developed. The distribution of the tracer activity was described as the sum of two different probability distributions, one for the normoxic (and necrotic), the other for the hypoxic voxels. The widths of the distributions arise due to variability of the transport, tumor tissue inhomogeneity, tracer binding kinetics, and due to PET image noise. Quantification of HF was performed for various levels of variability using two different methodologies: a) classification thresholds between normoxic and hypoxic voxels based on a non-hypoxic surrogate (muscle), and b) estimation of the (posterior) probability distributions based on maximizing likelihood optimization that does not require a surrogate. Data from the hypoxia imaging model and from 27 cervical cancer patients enrolled in a FAZA PET study were analyzed. Results: In the model, where the true value of HF is known, thresholds usually underestimate the value for large variability. For the patients, a significant uncertainty of the HF values (an average intra-patient range of 17%) was caused by spatial non-uniformity of image noise which is a hallmark of all PET images. Maximum likelihood estimation (MLE) is able to directly optimize for the weights of both distributions, however, may suffer from poor optimization convergence. For some patients, MLE-based HF values showed significant differences to threshold-based HF-values. Conclusion: HF-values depend critically on the magnitude of the different sources of tracer uptake variability. A measure of confidence should also be reported.

WE-H-207A-06: Hypoxia Quantification in Static PET Images: The Signal in the Noise

Energy Technology Data Exchange (ETDEWEB)

Keller, H; Yeung, I; Milosevic, M; Jaffray, D [University of Toronto, Toronto (Canada); Princess Margaret Cancer Centre, Toronto (Canada); Kueng, R [Princess Margaret Cancer Centre, Toronto (Canada); Inselspital Bern, Bern, Switzerland. (Switzerland); Shek, T; Driscoll, B [Princess Margaret Cancer Centre, Toronto (Canada)

2016-06-15

Purpose: Quantification of hypoxia from PET images is of considerable clinical interest. In the absence of dynamic PET imaging the hypoxic fraction (HF) of a tumor has to be estimated from voxel values of activity concentration of a radioactive hypoxia tracer. This work is part of an effort to standardize quantification of tumor hypoxic fraction from PET images. Methods: A simple hypoxia imaging model in the tumor was developed. The distribution of the tracer activity was described as the sum of two different probability distributions, one for the normoxic (and necrotic), the other for the hypoxic voxels. The widths of the distributions arise due to variability of the transport, tumor tissue inhomogeneity, tracer binding kinetics, and due to PET image noise. Quantification of HF was performed for various levels of variability using two different methodologies: a) classification thresholds between normoxic and hypoxic voxels based on a non-hypoxic surrogate (muscle), and b) estimation of the (posterior) probability distributions based on maximizing likelihood optimization that does not require a surrogate. Data from the hypoxia imaging model and from 27 cervical cancer patients enrolled in a FAZA PET study were analyzed. Results: In the model, where the true value of HF is known, thresholds usually underestimate the value for large variability. For the patients, a significant uncertainty of the HF values (an average intra-patient range of 17%) was caused by spatial non-uniformity of image noise which is a hallmark of all PET images. Maximum likelihood estimation (MLE) is able to directly optimize for the weights of both distributions, however, may suffer from poor optimization convergence. For some patients, MLE-based HF values showed significant differences to threshold-based HF-values. Conclusion: HF-values depend critically on the magnitude of the different sources of tracer uptake variability. A measure of confidence should also be reported.

The role of PET quantification in cardiovascular imaging.

Science.gov (United States)

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

2014-08-01

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

18F-FPYBF-2, a new F-18 labelled amyloid imaging PET tracer: biodistribution and radiation dosimetry assessment of first-in-man 18F-FPYBF-2 PET imaging.

Science.gov (United States)

Nishii, Ryuichi; Higashi, Tatsuya; Kagawa, Shinya; Okuyama, Chio; Kishibe, Yoshihiko; Takahashi, Masaaki; Okina, Tomoko; Suzuki, Norio; Hasegawa, Hiroshi; Nagahama, Yasuhiro; Ishizu, Koichi; Oishi, Naoya; Kimura, Hiroyuki; Watanabe, Hiroyuki; Ono, Masahiro; Saji, Hideo; Yamauchi, Hiroshi

2018-05-01

Recently, a benzofuran derivative for the imaging of β-amyloid plaques, 5-(5-(2-(2-(2- 18 F-fluoroethoxy)ethoxy)ethoxy)benzofuran-2-yl)- N-methylpyridin-2-amine ( 18 F-FPYBF-2) has been validated as a tracer for amyloid imaging and it was found that 18 F-FPYBF-2 PET/CT is a useful and reliable diagnostic tool for the evaluation of AD (Higashi et al. Ann Nucl Med, https://doi.org/10.1007/s12149-018-1236-1 , 2018). The aim of this study was to assess the biodistribution and radiation dosimetry of diagnostic dosages of 18 F-FPYBF-2 in normal healthy volunteers as a first-in-man study. Four normal healthy volunteers (male: 3, female: 1; mean age: 40 ± 17; age range 25-56) were included and underwent 18 F-FPYBF-2 PET/CT study for the evaluation of radiation exposure and pharmacokinetics. A 10-min dynamic PET/CT scan of the body (chest and abdomen) was performed at 0-10 min and a 15-min whole-body static scan was performed six times after the injection of 18 F-FPYBF-2. After reconstructing PET and CT image data, individual organ time-activity curves were estimated by fitting volume of interest data from the dynamic scan and whole-body scans. The OLINDA/EXM version 2.0 software was used to determine the whole-body effective doses. Dynamic PET imaging demonstrated that the hepatobiliary and renal systems were the principal pathways of clearance of 18 F-FPYBF-2. High uptake in the liver and the gall bladder, the stomach, and the kidneys were demonstrated, followed by the intestines and the urinary bladder. The ED for the adult dosimetric model was estimated to be 8.48 ± 1.25 µSv/MBq. The higher absorbed doses were estimated for the liver (28.98 ± 12.49 and 36.21 ± 15.64 µGy/MBq), the brain (20.93 ± 4.56 and 23.05 ± 5.03µ Gy/MBq), the osteogenic cells (9.67 ± 1.67 and 10.29 ± 1.70 µGy/MBq), the small intestines (9.12 ± 2.61 and 11.12 ± 3.15 µGy/MBq), and the kidneys (7.81 ± 2.62 and 8.71 ± 2.90 µGy/MBq) for

Clinical Application of 18F-FDG PET in Alzheimer's Disease

International Nuclear Information System (INIS)

Ryu, Young Hoon

2008-01-01

PET of the cerebral metabolic rate of glucose is increasingly used to support the clinical diagnosis in the examination of patients with suspected major neurodegenerative disorders, such as Alzheimer's disease. 18 F-FDG PET has been reported to have high diagnostic performance, especially, very high sensitivity in the diagnosis and clinical assessment of therapeutic efficacy. According to clinical research data hitherto, 18 F-FDG PET is expected to be an effective diagnostic tool in early and differential diagnosis of Alzheimer's disease. Since 2004, Medicare covers 18 F-FDG PET scans for the differential diagnosis of fronto-temporal dementia (FTD) and Alzheimer's disease (AD) under specific requirements; or, its use in a CMS approved practical clinical trial focused on the utility of 18 F-FDG PET in the diagnosis or treatment of dementing neurodegenerative diseases

Cardiac sympathetic neuronal imaging using PET

International Nuclear Information System (INIS)

Lautamaeki, Riikka; Tipre, Dnyanesh; Bengel, Frank M.

2007-01-01

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.)

One-Step 18F-Labeling of Estradiol Derivative for PET Imaging of Breast Cancer

Directory of Open Access Journals (Sweden)

Hongbo Huang

2018-01-01

Full Text Available Positron emission tomography (PET imaging is a useful method to evaluate in situ estrogen receptor (ER status for the early diagnosis of breast cancer and optimization of the appropriate treatment strategy. The 18F-labeled estradiol derivative has been successfully used to clinically assess the ER level of breast cancer. In order to simplify the radiosynthesis process, one-step 18F-19F isotope exchange reaction was employed for the 18F-fluorination of the tracer of [18F]AmBF3-TEG-ES. The radiotracer was obtained with the radiochemical yield (RCY of ~61% and the radiochemical purity (RCP of >98% within 40 min. Cell uptake and blocking assays indicated that the tracer could selectively accumulate in the ER-positive human breast cancer cell lines MCF-7 and T47D. In vivo PET imaging on the MCF-7 tumor-bearing mice showed relatively high tumor uptake (1.4~2.3 %D/g and tumor/muscle uptake ratio (4~6. These results indicated that the tracer is a promising PET imaging agent for ER-positive breast cancers.

Preparation, quality control and biodistribution of [61Cu]-doxorubicin for PET imaging

International Nuclear Information System (INIS)

Jalilian, A.R.; Akhlaghi, M.; Zandi, H.; Yousefnia, H.; Faghihi, R.

2009-01-01

This work was conducted for radiolabeling of an anticancer antibiotic, i.e. doxorubicin with 61 Cu for production of possible tracer used in PET oncology. 61 Cu was prepared with natural zinc target and 22 MeV 150 μA protons via nat Zn(p, xn) 61 Cu reaction with a yield of 123.2 MBq·μA -1 ·h -1 . Optimization reactions were performed for pH, temperature and concentration. Biodistribution of the tracer was studied in normal and fibrosarcoma bearing mice. At the optimized conditions, ITLC showed that radiochemical purity was over 97% with a specific activity of 2.22 X 10 3 MBq·mmol -1 ·L -1 . This was kept unchanged even with presence of human serum as well as room temperature for 5 h. Biodistribution of the tracer in fibrosarcoma bearing mice demonstrated significant tumor uptake after 2 h. This tracer can be used in the detection of various tumors responding to doxorubicin chemotherapy using PET scan and/or determination of tumor therapy response to doxorubicin chemotherapy. (authors)

Positron Emission Tomography (PET) Imaging of Opioid Receptors

NARCIS (Netherlands)

van Waarde, Aren; Absalom, Anthony; Visser, Anniek; Dierckx, Rudi; Dierckx, Rudi AJO; Otte, Andreas; De Vries, Erik FJ; Van Waarde, Aren; Luiten, Paul GM

2014-01-01

The opioid system consists of opioid receptors (which mediate the actions of opium), their endogenous ligands (the enkephalins, endorphins, endomorphins, dynorphin, and nociceptin), and the proteins involved in opioid production, transport, and degradation. PET tracers for the various opioid

PET/MR in oncology: an introduction with focus on MR and future perspectives for hybrid imaging

Science.gov (United States)

Balyasnikova, Svetlana; Löfgren, Johan; de Nijs, Robin; Zamogilnaya, Yanna; Højgaard, Liselotte; Fischer, Barbara M

2012-01-01

After more than 20 years of research, a fully integrated PET/MR scanner was launched in 2010 enabling simultaneous acquisition of PET and MR imaging. Currently, no clinical indication for combined PET/MR has been established, however the expectations are high. In this paper we will discuss some of the challenges inherent in this new technology, but focus on potential applications for simultaneous PET/MR in the field of oncology. Methods and tracers for use with the PET technology will be familiar to most readers of this journal; thus this paper aims to provide a short and basic introduction to a number of different MRI techniques, such as DWI-MR (diffusion weighted imaging MR), DCE-MR (dynamic contrast enhanced MR), MRS (MR spectroscopy) and MR for attenuation correction of PET. All MR techniques presented in this paper have shown promising results in the treatment of patients with solid tumors and could be applied together with PET increasing the amount of information about the tissues of interest. The potential clinical benefit of applying PET/MR in staging, radiotherapy planning and treatment evaluation in oncology, as well as the research perspectives for the use of PET/MR in the development of new tracers and drugs will be discussed. PMID:23145362

PET/CT in patients with hepatocellular carcinoma using [{sup 18}F]fluorocholine: preliminary comparison with [{sup 18}F]FDG PET/CT

Energy Technology Data Exchange (ETDEWEB)

Talbot, Jean-Noel; Gutman, Fabrice; Kerrou, Khaldoun; Grahek, Dany; Montravers, Francoise [Hopital Tenon, AP-HP, et Universite Pierre et Marie Curie, Department of Nuclear Medicine, Paris (France); Fartoux, Laetitia; Poupon, Raoul; Rosmorduc, Olivier [Hopital Saint-Antoine, AP-HP, et Universite Pierre et Marie Curie, Department of Hepatology, Paris (France); Grange, Jean-Didier [Hopital Tenon, AP-HP, et Universite Pierre et Marie Curie, Department of Hepatology, Paris (France); Ganne, Nathalie [Hopital Jean Verdier, AP-HP, Department of Hepatology, Bondy (France)

2006-11-15

The diagnostic accuracy of [{sup 18}F]fluorodeoxyglucose (FDG) PET is insufficient to characterise hepatocellular carcinoma (HCC) in liver masses and to diagnose all cases of recurrent HCC. HCC has been reported to take up [{sup 11}C]acetate, but routine use of this tracer is difficult. Choline is another tracer of lipid metabolism, present in large amounts in HCC. In a proof-of-concept study, we evaluated [{sup 18}F]fluorocholine (FCH) uptake by HCC and compared FCH PET/CT with FDG PET/CT. Twelve patients with newly diagnosed (n=8) or recurrent HCC (n=4) were prospectively enrolled. HCC was assessed by histology in eight cases and by American Association for the Study of Liver Diseases (AASLD) criteria in four cases. All patients underwent whole-body PET/CT 10 min after injection of 4 MBq/kg FCH. Within 1 week, 9 of the 12 patients also underwent whole-body FDG PET/CT 1 h after injection of 5 MBq/kg FDG. The per-patient analysis showed a detection rate of 12/12 using FCH PET/CT for both newly diagnosed and recurrent HCC. The median signal to noise ratio was 1.5{+-}0.38. There was a trend towards a higher FCH SUV{sub max} in well-differentiated HCC (15.6{+-}7.9 vs 11.9{+-}0.9, NS). Of the nine patients who underwent FCH and FDG PET/CT, all nine were positive with FCH whereas only five were positive with FDG. FCH provides a high detection rate for HCC, making it potentially useful in the initial evaluation of HCC or in the detection of recurrent disease. The favourable result of this proof-of-concept study opens the way to a phase III prospective study. (orig.)

Quantitative analysis of coronary endothelial function with generator-produced {sup 82}Rb PET: comparison with {sup 15}O-labelled water PET

Energy Technology Data Exchange (ETDEWEB)

Yoshinaga, Keiichiro [Hokkaido University Graduate School of Medicine, Department of Photobiology, Division of Molecular/Cellular Imaging, Kita-Ku, Sapporo, Hokkaido (Japan); Manabe, Osamu; Tamaki, Nagara [Hokkaido University of Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); Katoh, Chietsugu [Hokkaido University of Graduate School of Medicine, Department of Health Sciences, Sapporo (Japan); Chen, Li; Kemp, Robert A. de; Williams, Kathryn; Beanlands, Rob S.B. [University of Ottawa Heart Institute, National Cardiac PET Centre, Division of Cardiology, Ottawa, Ontario (Canada); Klein, Ran [Hokkaido University of Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan); University of Ottawa Heart Institute, National Cardiac PET Centre, Division of Cardiology, Ottawa, Ontario (Canada); Naya, Masanao [Hokkaido University of Graduate School of Medicine, Department of Cardiology, Sapporo (Japan)

2010-12-15

Endothelial dysfunction is the earliest abnormality in the development of coronary atherosclerosis. {sup 82}Rb is a generator-produced positron emission tomography (PET) myocardial perfusion tracer that is becoming more widely used. We aimed to (1) develop a method for quantitative assessment of coronary endothelial function using the myocardial blood flow (MBF) response during a cold pressor test (CPT) in smokers, measured using {sup 82}Rb PET, and (2) compare the results with those measured using {sup 15}O-water PET. MBF was assessed at rest and during the CPT with {sup 82}Rb and {sup 15}O-water in nine controls and ten smokers. A one-compartment model with tracer extraction correction was used to estimate MBF with both tracers. CPT response was calculated as the ratio of MBF during the CPT to MBF at rest. At rest, measurements of MBF for smokers vs controls were not different using {sup 15}O-water (0.86 {+-} 0.18 vs 0.70 {+-} 0.13, p = 0.426) than they were using {sup 82}Rb (0.83 {+-} 0.23 vs 0.62 {+-} 0.20, p = 0.051). Both methods showed a reduced CPT response in smokers vs controls ({sup 15}O-water, 1.03 {+-} 0.21 vs 1.42 {+-} 0.29, p = 0.006; {sup 82}Rb, 1.02 {+-} 0.28 vs 1.70 {+-} 0.52, p < 0.001). There was high reliability [intraclass correlation coefficients: 0.48 (0.07, 0.75)] of MBF measurement between {sup 82}Rb and {sup 15}O-water during the CPT. Using a CPT, {sup 82}Rb MBF measurements detected coronary endothelial dysfunctions in smokers. {sup 82}Rb MBF measurements were comparable to those made using the {sup 15}O-water approach. Thus, {sup 82}Rb PET may be applicable for risk assessments or evaluation of risk factor modification in subjects with coronary risk factors. (orig.)

Evaluation of early-phase [18F]-florbetaben PET acquisition in clinical routine cases

Directory of Open Access Journals (Sweden)

Sonja Daerr

2017-01-01

Conclusions: Early-phase FBB acquisitions correlate on a relative quantitative and visual level with FDG PET scans, irrespective of the amyloid plaque density assessed in late FBB imaging. Thus, early-phase FBB uptake depicts a metabolism-like image, suggesting it as a valid surrogate marker for synaptic dysfunction, which could ultimately circumvent the need for additional FDG PET investigation in diagnosis of dementia.

Delayed clearance of cerebrospinal fluid tracer from entorhinal cortex in idiopathic normal pressure hydrocephalus: A glymphatic magnetic resonance imaging study.

Science.gov (United States)

Eide, Per K; Ringstad, Geir

2018-01-01

The glymphatic system plays a key role for clearance of waste solutes from the rodent brain. We recently found evidence of glymphatic circulation in the human brain when using magnetic resonance imaging (MRI) contrast agent as cerebrospinal fluid (CSF) tracer in conjunction with multiple MRI acquisitions (gMRI). The present study explored the hypothesis that reduced glymphatic clearance in entorhinal cortex (ERC) may be instrumental in idiopathic normal pressure hydrocephalus (iNPH) dementia. gMRI acquisitions were obtained over a 24-48 h time span in cognitively affected iNPH patients and non-cognitively affected patients with suspected CSF leaks. The CSF tracer enrichment was determined as changes in normalized MRI T1 signal units. The study included 30 patients with iNPH and 8 individuals with suspected CSF leaks (i.e. reference individuals). Compared to reference individuals, iNPH patients presented with higher medial temporal lobe atrophy score and Evan's index and inferior ERC thickness. We found delayed clearance of the intrathecal CSF tracer gadobutrol from CSF, the ERC and adjacent white matter, suggesting impaired glymphatic circulation. Reduced clearance and accumulation of toxic waste product such as amyloid-β may be a mechanism behind dementia in iNPH. Glymphatic MRI (gMRI) may become a tool for assessment of early dementia.

A microvascular compartment model validated using 11C-methylglucose liver PET in pigs

Science.gov (United States)

Munk, Ole L.; Keiding, Susanne; Baker, Charles; Bass, Ludvik

2018-01-01

The standard compartment model (CM) is widely used to analyse dynamic PET data. The CM is fitted to time-activity curves to estimate rate constants that describe the transport of a tracer between well-mixed compartments. The aim of this study was to develop and validate a more realistic microvascular compartment model (MCM) that includes capillary tracer concentration gradients, backflux from cells into the perfused capillaries and multiple re-uptakes during the passage through a capillary. The MCM incorporates only parameters with clear physiological meaning, it is easy to implement, and it does not require numerical solution. We compared the MCM and CM for the analysis of 3 min dynamic PET data of pig livers (N  =  5) following injection of 11C-methylglucose. During PET scans, the tracer concentrations in blood were measured in the abdominal aorta, portal vein and liver vein by manual sampling. We found that the MCM outperformed the CM and that dynamic PET data include information which cannot be extracted using standard CM. The MCM fitted dynamic PET data better than the CM (Akaike values were 46  ±  4 for best MCM fits, and 82  ±  8 for best CM fits; mean  ±  standard deviation) and extracted physiologically reasonable parameter estimates such as blood perfusion that were in agreement with independent measurements. The difference between model-independent perfusion estimates and the best MCM perfusion estimates was  -0.01  ±  0.05 ml/ml/min, whereas the difference was 0.30  ±  0.13 ml/ml/min using the CM. In addition, the MCM predicted the time course of concentrations in the liver vein, a prediction fundamentally unobtainable using the CM as it does not return tracer backflux from cells to capillary blood. The results demonstrate the benefit of using models that include more physiology and that models including concentration gradients should be preferred when analysing the blood-cell exchange of

Therapeutic robocat for nursing home residents with dementia: preliminary inquiry.

Science.gov (United States)

Libin, Alexander; Cohen-Mansfield, Jiska

2004-01-01

Traditional pet therapy enhances individual well-being. However, there are situations where a substitute artificial companion (i.e., robotic pet) may serve as a better alternative because of insufficient available resources to care for a real pet, allergic responses to pets, or other difficulties. This pilot study, which compared the benefits of a robotic cat and a plush toy cat as interventions for elderly persons with dementia, was conducted at a special care unit of a large, not-for-profit nursing home. Various aspects of a person's engagement and affect were assessed through direct observations. Though not identical, similar trends were seen for the two cats. Interacting with the cats was linked with decreased agitation and increased pleasure and interest. The study is intended to pave the way for future research on robotherapy with nursing home residents.

Age and neurodegeneration imaging biomarkers in persons with Alzheimer disease dementia.

Science.gov (United States)

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

2016-08-16

To examine neurodegenerative imaging biomarkers in Alzheimer disease (AD) dementia from middle to old age. Persons with AD dementia and elevated brain β-amyloid with Pittsburgh compound B (PiB)-PET imaging underwent [(18)F]-fluorodeoxyglucose (FDG)-PET and structural MRI. We evaluated 3 AD-related neurodegeneration biomarkers: hippocampal volume adjusted for total intracranial volume (HVa), FDG standardized uptake value ratio (SUVR) in regions of interest linked to AD, and cortical thickness in AD-related regions of interest. We examined associations of each biomarker with age and evaluated age effects on cutpoints defined by the 90th percentile in AD dementia. We assembled an age-, sex-, and intracranial volume-matched group of 194 similarly imaged clinically normal (CN) persons. The 97 participants with AD dementia (aged 49-93 years) had PiB SUVR ≥1.8. A nonlinear (inverted-U) relationship between FDG SUVR and age was seen in the AD group but an inverse linear relationship with age was seen in the CN group. Cortical thickness had an inverse linear relationship with age in AD but a nonlinear (flat, then inverse linear) relationship in the CN group. HVa showed an inverse linear relationship with age in both AD and CN groups. Age effects on 90th percentile cutpoints were small for FDG SUVR and cortical thickness, but larger for HVa. In persons with AD dementia with elevated PiB SUVR, values of each neurodegeneration biomarker were associated with age. Cortical thickness had the smallest differences in 90th percentile cutpoints from middle to old age, and HVa the largest differences. © 2016 American Academy of Neurology.

Current status and prospects of cardiac PET

International Nuclear Information System (INIS)

Yoshida, Katuya

1999-01-01

With positron emission tomography (PET), noninvasive measurements of myocardial blood flow and metabolism have now become possible. 1) Myocardial blood flow: We developed a high-resolution PET system for rabbits and showed that myocardial N-13 ammonnia uptake correlated well with flow measure with microspheres. We also demonstrated that a simplified PET protocol using N-13 ammonia or Rb-82 provide noninvasive measurement of coronary flow reserve in dog experiments. This protocol enables to produce estimates of myocardial blood flow in man and that are well correlated with the complex compartment model. 2) Myocardial glucose metabolism: We validated experimentally a simple method to quantify tissue glucose utilization with the brain reference index (BRI) using C-14 deoxyglucose and assessed its clinical feasibility for myocardial PET. 3) Membrane integrity: Loss of cell membrane integrity for trapping the potassium or it's analog is a market of myocardial necrosis/viability. We recently synthetized potassium-38 as a PET tracer and started an experimental study. (author)

Somatostatin receptor PET in neuroendocrine tumours: 68Ga-DOTA0,Tyr3-octreotide versus 68Ga-DOTA0-lanreotide

International Nuclear Information System (INIS)

Putzer, Daniel; Kroiss, Alexander; Waitz, Dietmar; Gabriel, Michael; Uprimny, Christian; Guggenberg, Elisabeth von; Decristoforo, Clemens; Warwitz, Boris; Virgolini, Irene Johanna; Traub-Weidinger, Tatjana; Widmann, Gerlig

2013-01-01

The aim of this study was to evaluate the impact of 68 Ga-labelled DOTA 0 -lanreotide ( 68 Ga-DOTA-LAN) on the diagnostic assessment of neuroendocrine tumour (NET) patients with low to moderate uptake on planar somatostatin receptor (SSTR) scintigraphy or 68 Ga-labelled DOTA 0 ,Tyr 3 -octreotide ( 68 Ga-DOTA-TOC) positron emission tomography (PET). Fifty-three patients with histologically confirmed NET and clinical signs of progressive disease, who had not qualified for peptide receptor radionuclide therapy (PRRT) on planar SSTR scintigraphy or 68 Ga-DOTA-TOC PET (n = 38) due to lack of tracer uptake, underwent 68 Ga-DOTA-LAN PET to evaluate a treatment option with 90 Y-labelled lanreotide according to the MAURITIUS trial. The included patients received 150 ± 30 MBq of each radiopharmaceutical intravenously. PET scans were acquired 60-90 min after intravenous bolus injection. Image results from both PET scans were compared head to head, focusing on the intensity of tracer uptake in terms of treatment decision. CT was used for morphologic correlation of tumour lesions. To further evaluate the binding affinities of each tracer, quantitative and qualitative values were calculated for target lesions. 68 Ga-DOTA-LAN and 68 Ga-DOTA-TOC both showed equivalent findings in 24/38 patients when fused PET/CT images were interpreted. The sensitivity, specificity and accuracy of 68 Ga-DOTA-LAN in comparison to CT were 0.63, 0.5 and 0.62 (n = 53; p 68 Ga-DOTA-TOC in comparison to CT 0.78, 0.5 and 0.76 (n = 38; p 68 Ga-DOTA-TOC showed a significantly higher maximum standardized uptake value (SUV max ) regarding the primary tumour in 25 patients (p 68 Ga-DOTA-LAN. Corresponding values of both PET scans for tumour and liver did not show any significant correlation. 68 Ga-DOTA-TOC revealed more tumour sites than 68 Ga-DOTA-LAN (106 vs 53). The tumour to background ratios for tumour and liver calculated from SUV max measurements were significantly higher for 68 Ga-DOTA-TOC than 68 Ga

Approaches using molecular imaging technology - use of PET in clinical microdose studies§

OpenAIRE

Wagner, Claudia C.; Langer, Oliver

2011-01-01

Positron emission tomography (PET) imaging uses minute amounts of radiolabeled drug tracers and thereby meets the criteria for clinical microdose studies. The advantage of PET, when compared to other analytical methods used in microdose studies, is that the pharmacokinetics (PK) of a drug can be determined in the tissue targeted for drug treatment. PET microdosing already offers interesting applications in clinical oncology and in the development of central nervous system pharmaceuticals and ...

Clinical application of PET in abdominal cancers

International Nuclear Information System (INIS)

Choi, Chang Woon

2002-01-01

Clinical application of positron emission tomography (PET) is rapidly increasing for the detection and staging of cancer at whole-body studies performed with the glucose analogue tracer 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FG). Although FDG PET cannot match the anatomic resolution of conventional imaging techniques in the liver and the other abdominal organs, it is particularly useful for identification and characterization of the entire body simultaneously. FDG PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterizing of indeterminate soft-tissue masses. Most abdominal cancer requires surgical management. FGD PET can improve the selection of patients for surgical treatment and thereby reduce the morbidity and mortality associated with inappropriate surgery. FDG PET is also useful for the early detection of recurrence and the monitoring of therapeutic effect. The abdominal cancers, such as gastroesophageal cancer, colorectal cancer, liver cancer and pancreatic cancer, are common malignancies in Korea, and PET is one of the most promising and useful methodologies for the management of abdominal cancers

Use of PET and PET/CT for Radiation Therapy Planning: IAEA expert report 2006-2007

International Nuclear Information System (INIS)

MacManus, Michael; Nestle, Ursula; Rosenzweig, Kenneth E.; Carrio, Ignasi; Messa, Cristina; Belohlavek, Otakar; Danna, Massimo; Inoue, Tomio; Deniaud-Alexandre, Elizabeth; Schipani, Stefano; Watanabe, Naoyuki; Dondi, Maurizio; Jeremic, Branislav

2009-01-01

Positron Emission Tomography (PET) is a significant advance in cancer imaging with great potential for optimizing radiation therapy (RT) treatment planning and thereby improving outcomes for patients. The use of PET and PET/CT in RT planning was reviewed by an international panel. The International Atomic Energy Agency (IAEA) organized two synchronized and overlapping consultants' meetings with experts from different regions of the world in Vienna in July 2006. Nine experts and three IAEA staff evaluated the available data on the use of PET in RT planning, and considered practical methods for integrating it into routine practice. For RT planning, 18 F fluorodeoxyglucose (FDG) was the most valuable pharmaceutical. Numerous studies supported the routine use of FDG-PET for RT target volume determination in non-small cell lung cancer (NSCLC). There was also evidence for utility of PET in head and neck cancers, lymphoma and in esophageal cancers, with promising preliminary data in many other cancers. The best available approach employs integrated PET/CT images, acquired on a dual scanner in the radiotherapy treatment position after administration of tracer according to a standardized protocol, with careful optimization of images within the RT planning system and carefully considered rules for contouring tumor volumes. PET scans that are not recent or were acquired without proper patient positioning should be repeated for RT planning. PET will play an increasing valuable role in RT planning for a wide range of cancers. When requesting PET scans, physicians should be aware of their potential role in RT planning.

Development of 68Ga ethyl cysteinate dimer for PET studies

International Nuclear Information System (INIS)

Alireza Mirzaei; Jalilian, A.R.; Gholamali Shabani; Ashraf Fakhari; Mehdi Akhlaghi; Davood Beiki

2016-01-01

In this work development of 68 Ga-ethyl cysteinate dimer ( 68 Ga-ECD) a 68 Ga tracer for possible cerebral blood flow based on 99m Tc ECD homolog is reported. 68 Ga-ECD was prepared using generator-based 68 GaCl 3 and ECD at optimized conditions. Quality control, stability, partition co-efficient and the biodistribution of the tracer (by tissue counting and PET/CT in rats) was studied. Significant metabolism of the lipophilic tracer into water soluble metabolite(s) led to urinary excretion of the tracer, un-comparable to that of homologous 99m Tc-compound. Cardiac uptake of the complex suggests formation of a possible lipophil cationic complex and/or metabolite. (author)

PET-CT and PET-MRI of the prostate. From {sup 18}F-FDG to {sup 68}Ga-PSMA; PET-CT/-MRT der Prostata. Von {sup 18}F-FDG zu {sup 68}Ga-PSMA

Energy Technology Data Exchange (ETDEWEB)

Knorr, K.; Eiber, M.; Scheidhauer, K. [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Muenchen (Germany); Maurer, T. [Technische Universitaet Muenchen, Urologische Klinik und Poliklinik, Klinikum rechts der Isar, Muenchen (Germany); Wester, H.J. [Technische Universitaet Muenchen, Pharmazeutische Radiochemie, Garching (Germany)

2017-08-15

In the last few years nuclear medical diagnostics have experienced a unprecedented renaissance in the diagnostics of prostate cancer, due to the availability of hybrid imaging with positron emission tomography computed tomography (PET/CT), PET magnetic resonance imaging (PET/MRI) and single photon emission computed tomography (SPECT) CT as well as the development of prostate-specific radiopharmaceuticals. The use of fluorodeoxyglucose (FDG), which has been successfully implemented for many years in PET diagnostics, is only helpful in dedifferentiated tumors due to the biological characteristics of prostate cancer. New specific radiopharmaceuticals, such as choline-derivatives, which are incorporated into the prostate cancer cell and built into the cell membrane as well as the recently developed highly specific ligands for prostate-specific membrane antigen (PSMA) are revolutionizing prostate cancer imaging and (re-) staging. The {sup 68} Ga-labeled PSMA ligands for PET-CT and PET-MRI are highly specific tracers for primary diagnostics and detection of metastases of prostate carcinoma. In risk patients, which includes patients with intermediate and high-risk tumors, they have largely replaced choline-based PET-CT, especially in the case of very low PSA values <0.5 ng/ml in the diagnostics of recurrence. The use in the primary diagnostics as PET-MRI, also in combination with multiparametric MRI (mpMRI), is promising with respect to early diagnostics and image fusion-assisted biopsy as well as surgery and irradiation planning. (orig.) [German] Die nuklearmedizinische Diagnostik hat in den letzten Jahren bei der Bildgebung des Prostatakarzinoms eine rasante Entwicklung erlebt, sowohl aufgrund der verfuegbaren Hybridbildgebung mit der Positronenemissionstomographie(PET)-CT, PET-MRT sowie der Single-photon-emission-computed-tomography(SPECT)-CT als auch durch die Entwicklung prostataspezifischer Radiopharmaka. Die in der PET-Diagnostik seit Jahren erfolgreich eingesetzte

TH-E-202-02: The Use of Hypoxia PET Imaging for Radiotherapy

International Nuclear Information System (INIS)

Humm, J.

2016-01-01

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss: Pitfalls and remedies in PET/CT imaging for RT planning The use of hypoxia PET imaging for radiotherapy PET for tumor response evaluation The first presentation will address the issue of mis-registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image-guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de-escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi-quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non-FDG PET tracers for response assessment. Learning Objectives: Identify the causes of mis-registration of CT and PET images in PET/CT, and review the strategies to remedy the issue. Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo-radiation therapy). Understand the basics of dynamic PET imaging, compartmental modeling and parametric images. Understand the

TH-E-202-02: The Use of Hypoxia PET Imaging for Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Humm, J. [Memorial Sloan-Kettering Cancer Center (United States)

2016-06-15

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss: Pitfalls and remedies in PET/CT imaging for RT planning The use of hypoxia PET imaging for radiotherapy PET for tumor response evaluation The first presentation will address the issue of mis-registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image-guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de-escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi-quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non-FDG PET tracers for response assessment. Learning Objectives: Identify the causes of mis-registration of CT and PET images in PET/CT, and review the strategies to remedy the issue. Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo-radiation therapy). Understand the basics of dynamic PET imaging, compartmental modeling and parametric images. Understand the

Pharmacokinetic Analysis of 64Cu-ATSM Dynamic PET in Human Xenograft Tumors in Mice

DEFF Research Database (Denmark)

Li, Fan; Jørgensen, Jesper Tranekjær; Madsen, Jacob

2015-01-01

The aim of this study was to evaluate the feasibility to perform voxel-wise kinetic modeling on datasets obtained from tumor-bearing mice that underwent dynamic PET scans with 64Cu-ATSM and extract useful physiological parameters.METHODS: Tumor-bearing mice underwent 90-min dynamic PET scans...... relevant parameters from voxel-wise pharmacokinetic analysis to be used for preclinical validation of 64Cu-ATSM as a hypoxia-specific PET tracer....

Impact of molecular imaging on the diagnostic process in a memory clinic.

Science.gov (United States)

Ossenkoppele, Rik; Prins, Niels D; Pijnenburg, Yolande A L; Lemstra, Afina W; van der Flier, Wiesje M; Adriaanse, Sofie F; Windhorst, Albert D; Handels, Ron L H; Wolfs, Claire A G; Aalten, Pauline; Verhey, Frans R J; Verbeek, Marcel M; van Buchem, Mark A; Hoekstra, Otto S; Lammertsma, Adriaan A; Scheltens, Philip; van Berckel, Bart N M

2013-07-01

[(11)C]Pittsburgh compound B ([(11)C]PIB) and [(18)F]-2-fluoro-2-deoxy-D-glucose ([(18)F]FDG) PET measure fibrillar amyloid-β load and glucose metabolism, respectively. We evaluated the impact of these tracers on the diagnostic process in a memory clinic population. One hundred fifty-four patients underwent paired dynamic [(11)C]PIB and static [(18)F]FDG PET scans shortly after completing a standard dementia screening. Two-year clinical follow-up data were available for 39 patients. Parametric PET images were assessed visually and results were reported to the neurologists responsible for the initial diagnosis. Outcome measures were (change in) clinical diagnosis and confidence in that diagnosis before and after disclosing PET results. [(11)C]PIB scans were positive in 40 of 66 (61%) patients with a clinical diagnosis of Alzheimer's disease (AD), 5 of 18 (28%) patients with frontotemporal dementia (FTD), 4 of 5 (80%) patients with Lewy body dementia, and 3 of 10 (30%) patients with other dementias. [(18)F]FDG uptake patterns matched the clinical diagnosis in 38 of 66 (58%) of AD patients, and in 6 of 18 (33%) FTD patients. PET results led to a change in diagnosis in 35 (23%) patients. This only occurred when prior diagnostic certainty was Diagnostic confidence increased from 71 ± 17% before to 87 ± 16% after PET (p diagnostic work-up, especially when prior diagnostic confidence is low. Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Clinical utility of spatially normalized PET and SPECT to evaluate patients with memory and cognitive impairments

International Nuclear Information System (INIS)

Okumura, Ayumi; Nakayama, Noriyuki; Soeda, Akio; Miwa, Kazuhiro; Shinoda, Jun; Iwama, Toru

2004-01-01

We assessed cerebral metabolism and blood flow in patients with memory and other cognitive impairment using the easy Z score imaging system (eZIS) and statistical parametric mapping (SPM) of FDG-PET and SPECT scans. Twenty patients with dementia (12 Alzheimer's disease (AD), 3 diffuse Lewy body disease (DLB), and 2 frontotemporal dementia (FTD)) and twenty with diffuse axonal injury (DAI) and cognitive impairments were studied with FDG-PET and ECD-SPECT. All images were analyzed using eZIS with the same processing procedures, including smoothing, normalization, and z-transformation, and compared to a database of normals. Z score maps were super-imposed on 3D MRI brain images. Group analyses were performed using SPM. Age-related declines in cerebral metabolism and blood flow were observed in the anterior cingulate association area. In contrast, reductions in these cerebral functions correlated best with severity of AD in the posterior cingulate association areas. In DLB and FTD, eZIS analysis of PET and SPECT revealed reductions of cerebral functions in specific areas. DAI showed low metabolism and blood flow in mesiofrontal cortex including the anterior cingulate association area. Dysfunction of the anterior cingulate association area in DAI, which resembled age-related cognitive decline, may be responsible for cognitive impairments. Overall, PET and SPECT scans showed significant correlations according to the type of dementia. Spatially normalized maps contributed to PET and SPECT image interpretation for patients with memory and cognitive impairments because better 3D visualization allowed more objective and systematic investigations. (author)

Automatic extraction of forward stroke volume using dynamic PET/CT

DEFF Research Database (Denmark)

Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik Stubkjær

2015-01-01

Background The aim of this study was to develop and validate an automated method for extracting forward stroke volume (FSV) using indicator dilution theory directly from dynamic positron emission tomography (PET) studies for two different tracers and scanners. Methods 35 subjects underwent...... a dynamic 11 C-acetate PET scan on a Siemens Biograph TruePoint-64 PET/CT (scanner I). In addition, 10 subjects underwent both dynamic 15 O-water PET and 11 C-acetate PET scans on a GE Discovery-ST PET/CT (scanner II). The left ventricular (LV)-aortic time-activity curve (TAC) was extracted automatically...... from PET data using cluster analysis. The first-pass peak was isolated by automatic extrapolation of the downslope of the TAC. FSV was calculated as the injected dose divided by the product of heart rate and the area under the curve of the first-pass peak. Gold standard FSV was measured using phase...

Radiosynthesis and biological evaluation of 5-(3-[18F]Fluoropropyloxy)-L-tryptophan for tumor PET imaging

International Nuclear Information System (INIS)

He, Shanzhen; Tang, Ganghua; Hu, Kongzhen; Wang, Hongliang; Wang, Shuxia; Huang, Tingting; Liang, Xiang; Tang, Xiaolan

2013-01-01

Introduction: [ 18 F]FDG PET has difficulty distinguishing tumor from inflammation in the clinic because of the same high uptake in nonmalignant and inflammatory tissue. In contrast, amino acid tracers do not accumulate in inflamed tissues and thus provide an excellent opportunity for their use in clinical cancer imaging. In this study, we developed a new amino acid tracer 5-(3-[ 18 F]Fluoropropyloxy)-L-tryptophan ([ 18 F]-L-FPTP) by two-step reactions and performed its biologic evaluation. Methods: [ 18 F]-L-FPTP was prepared by [ 18 F]fluoropropylation of 5-hydroxy-L-tryptophan disodium salt and purification on C18 cartridges. The biodistribution of [ 18 F]-L-FPTP was determined in normal mice and the incorporation of [ 18 F]-L-FPTP into tissue proteins was investigated. In vitro competitive inhibition experiments were performed with Hepa1-6 hepatoma cell lines. [ 18 F]-L-FPTP PET imaging was performed on tumor-bearing and inflammation mice and compared with [ 18 F]-L-FEHTP PET. Results: The overall uncorrected radiochemical yield of [ 18 F]-L-FPTP was 21.1 ± 4.4% with a synthesis time of 60 min, the radiochemical purity was more than 99%. Biodistribution studies demonstrate high uptake of [ 18 F]-L-FPTP in liver, kidney, pancreas, and blood at the early phase, and fast clearance in most tissues over the whole observed time. The uptake studies in Hepa1-6 cells suggest that [ 18 F]-L-FPTP is transported by the amino acid transport system B 0,+ , LAT2 and ASC. [ 18 F]-L-FPTP displays good stability and is not incorporated into proteins in vitro. PET imaging shows that [ 18 F]-L-FPTP can be a better potential PET tracer for differentiating tumor from inflammation than [ 18 F]FDG and 5-(3-[ 18 F]fluoroethyloxy)-L-tryptophan ([ 18 F]-L-FEHTP), with high [ 18 F]-L-FPTP uptake ratio (2.53) of tumor to inflammation at 60 min postinjection. Conclusions: Using [ 18 F]fluoropropyl derivatives as intermediates, the new tracer [ 18 F]-L-FPTP was achieved with good yield and

In vivo PET/CT in a human glioblastoma chicken chorioallantoic membrane model: a new tool for oncology and radiotracer development.

Science.gov (United States)

Warnock, Geoff; Turtoi, Andrei; Blomme, Arnaud; Bretin, Florian; Bahri, Mohamed Ali; Lemaire, Christian; Libert, Lionel Cyrille; Seret, Alain E J J; Luxen, André; Castronovo, Vincenzo; Plenevaux, Alain R E G

2013-10-01

For many years the laboratory mouse has been used as the standard model for in vivo oncology research, particularly in the development of novel PET tracers, but the growth of tumors on chicken chorioallantoic membrane (CAM) provides a more rapid, low cost, and ethically sustainable alternative. For the first time, to our knowledge, we demonstrate the feasibility of in vivo PET and CT imaging in a U87 glioblastoma tumor model on chicken CAM, with the aim of applying this model for screening of novel PET tracers. U87 glioblastoma cells were implanted on the CAM at day 11 after fertilization and imaged at day 18. A small-animal imaging cell was used to maintain incubation and allow anesthesia using isoflurane. Radiotracers were injected directly into the exposed CAM vasculature. Sodium (18)F-fluoride was used to validate the imaging protocol, demonstrating that image-degrading motion can be removed with anesthesia. Tumor glucose metabolism was imaged using (18)F-FDG, and tumor protein synthesis was imaged using 2-(18)F-fluoro-l-tyrosine. Anatomic images were obtained by contrast-enhanced CT, facilitating clear delineation of the tumor, delineation of tracer uptake in tumor versus embryo, and accurate volume measurements. PET imaging of tumor glucose metabolism and protein synthesis was successfully demonstrated in the CAM U87 glioblastoma model. Catheterization of CAM blood vessels facilitated dynamic imaging of glucose metabolism with (18)F-FDG and demonstrated the ability to study PET tracer uptake over time in individual tumors, and CT imaging improved the accuracy of tumor volume measurements. We describe the novel application of PET/CT in the CAM tumor model, with optimization of typical imaging protocols. PET imaging in this valuable tumor model could prove particularly useful for rapid, high-throughput screening of novel radiotracers.

Amyloid PET imaging in Alzheimer's disease: a comparison of three radiotracers

Energy Technology Data Exchange (ETDEWEB)

Landau, S.M.; Jagust, W.J. [University of California, Berkeley, Helen Wills Neuroscience Institute, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Life Sciences Division, Berkeley, CA (United States); Thomas, B.A. [University College London, Institute of Nuclear Medicine, London (United Kingdom); Thurfjell, L. [GE Healthcare, Uppsala (Sweden); Schmidt, M. [Janssen Pharmaceutica, NV, Beerse (Belgium); Margolin, R. [Janssen Alzheimer Immunotherapy, South San Francisco, CA (United States); Mintun, M.; Pontecorvo, M. [Avid Radiopharmaceuticals, Inc., Philadelphia, PA (United States); Baker, S.L. [Lawrence Berkeley National Laboratory, Life Sciences Division, Berkeley, CA (United States); Collaboration: The Alzheimer' s Disease Neuroimaging Initiative

2014-07-15

The increasing use of amyloid PET in Alzheimer's disease research and clinical trials has motivated efforts to standardize methodology. We compared retention of the {sup 11}C radiotracer Pittsburgh Compound B (PiB) and that of two {sup 18}F amyloid radiotracers (florbetapir and flutemetamol) using two study populations. We also examined the feasibility of converting between tracer-specific measures, using PiB as the common link between the two {sup 18}F tracers. One group of 40 subjects underwent PiB and flutemetamol imaging sessions and a separate group of 32 subjects underwent PiB and florbetapir imaging sessions. We compared cortical and white matter retention for each {sup 18}F tracer relative to that of PiB, as well as retention in several reference regions and image analysis methods. Correlations between tracer pairs were used to convert tracer-specific threshold values for amyloid positivity between tracers. Cortical retention for each pair of tracers was strongly correlated regardless of reference region (PiB-flutemetamol, ρ = 0.84-0.99; PiB-florbetapir, ρ = 0.83-0.97) and analysis method (ρ = 0.90-0.99). Compared to PiB, flutemetamol had higher white matter retention, while florbetapir had lower cortical retention. Two previously established independent thresholds for amyloid positivity were highly consistent when values were converted between tracer pairs. Despite differing white and grey matter retention characteristics, cortical retention for each {sup 18}F tracer was highly correlated with that of PiB, enabling conversion of thresholds across tracer measurement scales with a high level of internal consistency. Standardization of analysis methods and measurement scales may facilitate the comparison of amyloid PET data obtained using different tracers. (orig.)

Radiosynthesis of N-¹¹C-Methyl-Taurine-Conjugated Bile Acids and Biodistribution Studies in Pigs by PET/CT.

Science.gov (United States)

Schacht, Anna Christina; Sørensen, Michael; Munk, Ole Lajord; Frisch, Kim

2016-04-01

During cholestasis, accumulation of conjugated bile acids may occur in the liver and lead to hepatocellular damage. Inspired by our recent development of N-(11)C-methyl-glycocholic acid-that is, (11)C-cholylsarcosine-a tracer for PET of the endogenous glycine conjugate of cholic acid, we report here a radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids and biodistribution studies in pigs by PET/CT. A radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids was developed and used to prepare N-(11)C-methyl-taurine conjugates derived from cholic, chenodeoxycholic, deoxycholic, ursodeoxycholic, and lithocholic acid. The lipophilicity of these new tracers was determined by reversed-phase thin-layer chromatography. The effect of lipophilicity and structure on the biodistribution was investigated in pigs by PET/CT using the tracers derived from cholic acid (3α-OH, 7α-OH, 12α-OH), ursodeoxycholic acid (3α-OH, 7β-OH), and lithocholic acid (3α-OH). The radiosyntheses of the N-(11)C-methyl-taurine-conjugated bile acids proceeded with radiochemical yields of 61% (decay-corrected) or greater and radiochemical purities greater than 99%. PET/CT in pigs revealed that the tracers were rapidly taken up by the liver and secreted into bile. There was no detectable radioactivity in urine. Significant reflux of N-(11)C-methyl-taurolithocholic acid into the stomach was observed. We have successfully developed a radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids. These tracers behave in a manner similar to endogenous taurine-conjugated bile acids in vivo and are thus promising for functional PET of patients with cholestatic diseases. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

PET application in psychiatry and psychopharmacology

Energy Technology Data Exchange (ETDEWEB)

Suhara, Tetsuya [National Inst. of Radiological Sciences, Chiba (Japan)

1999-07-01

In the last few decades diagnostic and research tools in the medical field have made great advances, yet psychiatry has lacked sufficiently sensitive tools to measure the aberration of brain functions. Recently however, the development of Positron emission tomography (PET) techniques has made it possible to measure changes in neurochemical components in mental disorders and the effect of psychoactive drugs in living human brain. Most of the advancement in the psychiatric field has came from the development psychoactive drugs. Brain research involving identification of neurotransmission is largely based on compounds developed in psychopharmacology. Some of these compounds have been radiolabelled and used as radioligands for quantitative examination of neuroreceptors and other aspects of neurotransmission. Using PET, radioligand binding can now be examined in the human brain in vivo. PET techniques also allow examination of an unlabelled drug by examination of its interaction with a radioligand. So one potential of PET in psychiatry is to investigate the mechanism of psychoactive drugs. Antidepressants modulate serotonin transmission by inhibiting serotonin reuptake from the synaptic cleft. High affinity [{sup 3}H]imipramine binding sites in mammalian brain have been labelled to investigate serotonin transporters in living human brain by PET. Cyanoimipramine which is described as a potent serotonin reuptake inhibitor, was labelled with {sup 11}C. In a PET experiment with 6 healthy human subjects, a high accumulation of [{sup 11}C]cyanoimipramine was found in the thalamus and striatum and lowest accumulation was observed in the cerebellum, a region relatively void of serotonin transporters. The thalamus to cerebellum ratio was about 2 at 90 min after the injection of the tracer. Recently, [{sup 11}C]McN5652-X has been introduced as a better tracer for serotonin transporter imaging. Employing [{sup 11}C]McN5652-X in a PET study of 7 healthy human subjects, a high

PET application in psychiatry and psychopharmacology

International Nuclear Information System (INIS)

Suhara, Tetsuya

1999-01-01

In the last few decades diagnostic and research tools in the medical field have made great advances, yet psychiatry has lacked sufficiently sensitive tools to measure the aberration of brain functions. Recently however, the development of Positron emission tomography (PET) techniques has made it possible to measure changes in neurochemical components in mental disorders and the effect of psychoactive drugs in living human brain. Most of the advancement in the psychiatric field has came from the development psychoactive drugs. Brain research involving identification of neurotransmission is largely based on compounds developed in psychopharmacology. Some of these compounds have been radiolabelled and used as radioligands for quantitative examination of neuroreceptors and other aspects of neurotransmission. Using PET, radioligand binding can now be examined in the human brain in vivo. PET techniques also allow examination of an unlabelled drug by examination of its interaction with a radioligand. So one potential of PET in psychiatry is to investigate the mechanism of psychoactive drugs. Antidepressants modulate serotonin transmission by inhibiting serotonin reuptake from the synaptic cleft. High affinity [ 3 H]imipramine binding sites in mammalian brain have been labelled to investigate serotonin transporters in living human brain by PET. Cyanoimipramine which is described as a potent serotonin reuptake inhibitor, was labelled with 11 C. In a PET experiment with 6 healthy human subjects, a high accumulation of [ 11 C]cyanoimipramine was found in the thalamus and striatum and lowest accumulation was observed in the cerebellum, a region relatively void of serotonin transporters. The thalamus to cerebellum ratio was about 2 at 90 min after the injection of the tracer. Recently, [ 11 C]McN5652-X has been introduced as a better tracer for serotonin transporter imaging. Employing [ 11 C]McN5652-X in a PET study of 7 healthy human subjects, a high accumulation was observed

Visualization of multiple organ amyloid involvement in systemic amyloidosis using {sup 11}C-PiB PET imaging

Energy Technology Data Exchange (ETDEWEB)

Ezawa, Naoki; Katoh, Nagaaki; Yoshinaga, Tsuneaki [Shinshu University School of Medicine, Department of Medicine (Neurology and Rheumatology), Nagano (Japan); Oguchi, Kazuhiro [Jisenkai Brain Imaging Research Center, Matsumoto (Japan); Yazaki, Masahide [Shinshu University School of Health Sciences, Department of Biomedical Laboratory Sciences, Matsumoto (Japan); Shinshu University, Institute for Biomedical Sciences, Matsumoto (Japan); Sekijima, Yoshiki [Shinshu University School of Medicine, Department of Medicine (Neurology and Rheumatology), Nagano (Japan); Jisenkai Brain Imaging Research Center, Matsumoto (Japan); Shinshu University, Institute for Biomedical Sciences, Matsumoto (Japan)

2018-03-15

To investigate the utility of Pittsburgh compound B (PiB) positron emission tomography (PET) imaging for evaluating whole-body amyloid involvement in patients with systemic amyloidosis. Whole-body {sup 11}C-PiB PET was performed in seven patients with systemic immunoglobulin light-chain (AL) amyloidosis, seven patients with hereditary transthyretin (ATTRm) amyloidosis, one asymptomatic TTR mutation carrier and three healthy controls. The correlations between clinical organ involvement, radiological {sup 11}C-PiB uptake and histopathological findings were analysed for each organ. Organ involvement on {sup 11}C-PiB PET imaging showed good correlations with the clinical findings for the heart and stomach. Abnormal tracer uptake was also observed in the spleen, lachrymal gland, submandibular gland, sublingual gland, lymph node, brain, scalp, extraocular muscles, nasal mucosa, pharynx, tongue and nuchal muscles, most of which were asymptomatic. Physiological tracer uptake was universally observed in the urinary tract (kidney, renal pelvis, ureter and bladder) and enterohepatic circulatory system (liver, gallbladder, bile duct and small intestine) in all participants. Most of the patients and one healthy control subject showed asymptomatic tracer uptake in the lung and parotid gland. The peripheral nervous system did not show any tracer uptake even in patients with apparent peripheral neuropathy. Histological amyloid deposition was confirmed in biopsied myocardium and gastric mucosa where abnormal {sup 11}C-PiB retention was observed. {sup 11}C-PiB PET imaging can be used clinically in the systemic evaluation of amyloid distribution in patients with AL and ATTRm amyloidosis. Quantitative analysis of {sup 11}C-PiB PET images may be useful in therapy evaluation and will reveal whether amyloid clearance is correlated with clinical response. (orig.)

Preparation and evaluation of 68Ga-ECC as a PET renal imaging agent

International Nuclear Information System (INIS)

Mizaei, Alireza; Jaililan, Amir Reza; Mazidi, Mohammad; Aghanejad, Ayuob; Yousefnia, Hassan; Shabani, Gholamli; Ardaneh, Khosro; Geramifar, Patham; Beiki, Davood

2015-01-01

Development of a gallium-68-labeled renal tracer can be a good substitute for Tc-99m, a known SPECT tracer. In this study, effort was made to develop 68 Ga-ethylenecysteamine cysteine ( 68 Ga-ECC). Ga-ECC was prepared using generator-based 68 GaCl3 and ethylenecysteamine cysteine (ECC) at optimized conditions. Stability of the complex was checked in human serum followed by partition coefficient determination of the tracer. The biodistribution of the tracer in rats was studied using tissue counting and PET/CT imaging up to 120 min. Ga-ECC was prepared at optimized conditions in 15 min at 90 °C (radiochemical purity ≈97 ± 0.88 % ITLC, >99 % HPLC, specific activity: 210 ± 5 GBq/mM). 68 Ga-ECC was a water-soluble complex based on partition coefficient data (log P; −1.378) and was stable in the presence of human serum for 2 h at 37 °C. The biodistribution of the tracer demonstrated high kidney excretion of the tracer in 10–20 min. The SUV max ratios of the liver to left kidney were 0.38 and 0.39 for 30 and 90 min, respectively, indicating high kidney uptake. Initial biodistribution results showed significant kidney and urinary excretion of the tracer comparable to that of the homologous 99m Tc compound. The complex could be a possible PET kidney imaging agent with a fast imaging time

Therapy assessment in prostate cancer using choline and PSMA PET/CT

Energy Technology Data Exchange (ETDEWEB)

Ceci, Francesco; Castellucci, Paolo; Fanti, Stefano [University of Bologna, Nuclear Medicine Unit, S. Orsola-Malpighi University Hospital, Bologna (Italy); Herrmann, Ken [University Hospital Essen, Department of Nuclear Medicine, Essen (Germany); University of California Los Angeles, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, CA (United States); Hadaschik, Boris [University Hospital Essen, Department of Urology, Essen (Germany)

2017-08-15

While PET with non-FDG tracers (mainly choline and Ga-PSMA) has commonly been used for restaging in men with biochemically recurrent prostate cancer, as well as for primary staging, it is only recently that a few preliminary studies have addressed the possible use of PET for monitoring the response to systemic therapy of metastatic disease, especially innovative treatments such as abiraterone and enzalutamide. This article aims to evaluate the role of PET imaging with different non-FDG radiotracers for assessment of therapy in advanced prostate cancer patients. (orig.)

Comparison of {sup 18}F-FET and {sup 18}F-FDG PET in brain tumors

Energy Technology Data Exchange (ETDEWEB)

Pauleit, Dirk; Stoffels, Gabriele [Institute of Neuroscience and Medicine, Forschungszentrum Juelich, D-52425 Juelich (Germany); Bachofner, Ansgar [Clinic of Nuclear Medicine, Heinrich-Heine-University, D-40001 Duesseldorf (Germany); Floeth, Frank W.; Sabel, Michael [Department of Neurosurgery, Heinrich-Heine-University, D-40001 Duesseldorf (Germany); Herzog, Hans; Tellmann, Lutz [Institute of Neuroscience and Medicine, Forschungszentrum Juelich, D-52425 Juelich (Germany); Jansen, Paul [Institute of Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany); Reifenberger, Guido [Department of Neuropathology, Heinrich-Heine-University, D-40001 Duesseldorf (Germany); Hamacher, Kurt; Coenen, Heinz H. [Institute of Neuroscience and Medicine, Forschungszentrum Juelich, D-52425 Juelich (Germany); Langen, Karl-Josef [Institute of Neuroscience and Medicine, Forschungszentrum Juelich, D-52425 Juelich (Germany)], E-mail: k.j.langen@fz-juelich.de

2009-10-15

The purpose of this study was to compare the diagnostic value of positron emission tomography (PET) using [{sup 18}F]-fluorodeoxyglucose ({sup 18}F-FDG) and O-(2-[{sup 18}F]fluoroethyl)-L-tyrosine ({sup 18}F-FET) in patients with brain lesions suspicious of cerebral gliomas. Methods: Fifty-two patients with suspicion of cerebral glioma were included in this study. From 30 to 50 min after injection of 180 MBq {sup 18}F-FET, a first PET scan ({sup 18}F-FET scan) was performed. Thereafter, 240 MBq {sup 18}F-FDG was injected and a second PET scan was acquired from 30 to 60 min after the second injection ({sup 18}F-FET/{sup 18}F-FDG scan). The cerebral accumulation of {sup 18}F-FDG was calculated by decay corrected subtraction of the {sup 18}F-FET scan from the {sup 18}F-FET/{sup 18}F-FDG scan. Tracer uptake was evaluated by visual scoring and by lesion-to-background (L/B) ratios. The imaging results were compared with the histological results and prognosis. Results: Histology revealed 24 low-grade gliomas (LGG) of World Health Organization (WHO) Grade II and 19 high-grade gliomas (HGG) of WHO Grade III or IV, as well as nine others, mainly benign histologies. The gliomas showed increased {sup 18}F-FET uptake (>normal brain) in 86% and increased {sup 18}F-FDG uptake (>white matter) in 35%. {sup 18}F-FET PET provided diagnostically useful delineation of tumor extent while this was impractical with {sup 18}F-FDG due to high tracer uptake in the gray matter. A local maximum in the tumor area for biopsy guidance could be identified with {sup 18}F-FET in 76% and with {sup 18}F-FDG in 28%. The L/B ratios showed significant differences between LGG and HGG for both tracers but considerable overlap so that reliable preoperative grading was not possible. A significant correlation of tracer uptake with overall survival was found with {sup 18}F-FDG only. In some benign lesions like abscesses, increased uptake was observed for both tracers indicating a limited specificity of both

Clinical experience with a commercially available negative oral contrast medium in PET/CT

International Nuclear Information System (INIS)

Hausegger, K.; Reinprecht, P.; Kau, T.; Igerc, I.; Lind, P.

2005-01-01

Purpose: to evaluate a commercially available negative oral contrast material for PET/CT. Material and methods: in a prospective series of 49 patients, Mukofalk registered , which is a vegetarian-based substance, was used as a negative oral contrast medium in whole body PET/CT studies. Mukofalk was administered during a time period of 1.5 hours before the examination. Quality of small bowl distension and eventual pathological tracer uptake in the intestine were evaluated. Results: distension of the small bowel was excellent or good in 41 (85%) and poor in 8 (15%) patients. Mild tracer uptake in the small bowel was observed in 5 patients (10.2%) and moderate uptake in another 2 patients (4%). In none of these patients did the F-18 FDG uptake interfere with image interpretation. Conclusion: Mukofalk registered can be used as a negative oral contrast medium in PET/CT studies. (orig.)

Clinical experience with a commercially available negative oral contrast medium in PET/CT

Energy Technology Data Exchange (ETDEWEB)

Hausegger, K.; Reinprecht, P. [Roentgendiagnostisches Zentralinstitut, LKH Klagenfurt (Austria); Kau, T. [Roentgendiagnostisches Zentral Inst., Klagenfurt (Austria); Igerc, I.; Lind, P. [Abt. fuer Nuklearmedizin und Spezielle Endokrinologie, LKH Klagenfurt (Austria)

2005-06-01

Purpose: to evaluate a commercially available negative oral contrast material for PET/CT. Material and methods: in a prospective series of 49 patients, Mukofalk {sup registered}, which is a vegetarian-based substance, was used as a negative oral contrast medium in whole body PET/CT studies. Mukofalk was administered during a time period of 1.5 hours before the examination. Quality of small bowl distension and eventual pathological tracer uptake in the intestine were evaluated. Results: distension of the small bowel was excellent or good in 41 (85%) and poor in 8 (15%) patients. Mild tracer uptake in the small bowel was observed in 5 patients (10.2%) and moderate uptake in another 2 patients (4%). In none of these patients did the F-18 FDG uptake interfere with image interpretation. Conclusion: Mukofalk {sup registered} can be used as a negative oral contrast medium in PET/CT studies. (orig.)

Review on PET radiopharmaceuticals: from isotopes and molecules to medical applications

International Nuclear Information System (INIS)

Seimbille, Yann

2014-01-01

Molecular imaging of living subjects is an emerging field that aims to study molecular and cellular events in the intact living animal and human. Unlike classical biology, molecular imaging allows to study biological processes with cells residing in their native environment in the living subjects. Positron Emission Tomography (PET) is actually one of the preferred molecular imaging tool for its high sensitivity and its capability to non-invasively and quantitatively visualize in vivo cellular events in the non- or sub-pharmacologic concentration (nano to picomolar) without affecting biological processes. An overview of the principles of this imaging technique and a comparison with other imaging modalities will be presented. Combination of PET technology with conventional anatomical imaging (computed tomography (CT), magnetic resonance imaging (MRI)) or with another molecular imaging technique is getting more and more relevant, and such hybrid imaging is often best suited to answer specific biological or medical question. PET imaging requires the injection of a radioactive tracer, which is made of a positron-emitting isotope that allows signal detection and a chemically specific pharmacophore that interacts with the intended molecular target. Infrastructure, methods and regulation about the production of the different radionuclides of interest and the synthesis of PET tracers will be discussed. Recent novel radiolabelling strategies, as well as new technologies (i.e. micro fluidic), to generate libraries of PET radiopharmaceuticals will also be covered in this presentation

Kinetic Modeling of the Tau PET Tracer 18F-AV-1451 in Human Healthy Volunteers and Alzheimer Disease Subjects.

Science.gov (United States)

Barret, Olivier; Alagille, David; Sanabria, Sandra; Comley, Robert A; Weimer, Robby M; Borroni, Edilio; Mintun, Mark; Seneca, Nicholas; Papin, Caroline; Morley, Thomas; Marek, Ken; Seibyl, John P; Tamagnan, Gilles D; Jennings, Danna

2017-07-01

18 F-AV-1451 is currently the most widely used of several experimental tau PET tracers. The objective of this study was to evaluate 18 F-AV-1451 binding with full kinetic analysis using a metabolite-corrected arterial input function and to compare parameters derived from kinetic analysis with SUV ratio (SUVR) calculated over different imaging time intervals. Methods: 18 F-AV-1451 PET brain imaging was completed in 16 subjects: 4 young healthy volunteers (YHV), 4 aged healthy volunteers (AHV), and 8 Alzheimer disease (AD) subjects. Subjects were imaged for 3.5 h, with arterial blood samples obtained throughout. PET data were analyzed using plasma and reference tissue-based methods to estimate the distribution volume, binding potential (BP ND ), and SUVR. BP ND and SUVR were calculated using the cerebellar cortex as a reference region and were compared across the different methods and across the 3 groups (YHV, AHV, and AD). Results: AD demonstrated increased 18 F-AV-1451 retention compared with YHV and AHV based on both invasive and noninvasive analyses in cortical regions in which paired helical filament tau accumulation is expected in AD. A correlation of R 2 > 0.93 was found between BP ND (130 min) and SUVR-1 at all time intervals. Cortical SUVR curves reached a relative plateau around 1.0-1.2 for YHV and AHV by approximately 50 min, but increased in AD by up to approximately 20% at 110-130 min and approximately 30% at 160-180 min relative to 80-100 min. Distribution volume (130 min) was lower by 30%-35% in the YHV than AHV. Conclusion: Our data suggest that although 18 F-AV-1451 SUVR curves do not reach a plateau and are still increasing in AD, an SUVR calculated over an imaging window of 80-100 min (as currently used in clinical studies) provides estimates of paired helical filament tau burden in good correlation with BP ND , whereas SUVR sensitivity to regional cerebral blood changes needs further investigation. © 2017 by the Society of Nuclear Medicine and

18F-labelled annexin V: a PET tracer for apoptosis imaging

International Nuclear Information System (INIS)

Murakami, Yoshihiro; Tatsumi, Mitsuyoshi; Ichise, Rikiya; Nishimura, Shintaro; Takamatsu, Hiroyuki; Noda, Akihiro; Taki, Junichi; Tait, Jonathan F.

2004-01-01

Annexin V can be used to detect apoptotic cells in vitro and in vivo, based on its ability to identify extracellular phosphatidylserine, which arises during apoptosis. In the present study, we examined the synthesis of fluorine-18 labelled annexin V as a positron emission tomography tracer for apoptosis imaging. The distribution of [ 18 F]annexin V and technetium-99m labelled annexin V, a well-characterised SPET tracer for apoptosis imaging, was compared. [ 18 F]annexin V was synthesised using N-succinimidyl 4-[ 18 F]fluorobenzoate as an 18 F labelling reagent. Synthesised and purified [ 18 F]annexin V was confirmed by SDS-PAGE. In an ex vivo imaging experiment, [ 18 F]annexin V was intravenously injected into rats 24 h after the induction of myocardial ischaemia, and accumulation in the left ventricle was examined. [ 18 F]annexin V accumulated in the infarct area of the left ventricle, where apoptotic cells were observed. In separate experiments, [ 18 F]annexin V or [ 99m Tc]annexin V was intravenously injected into ischaemic or normal animals, and the distribution of the tracers was compared. In ischaemic animals, accumulation of [ 18 F]annexin V and [ 99m Tc]annexin V in the infarct area was about threefold higher than in the non-infarct area. Furthermore, the ratio of accumulation in the normal heart to the blood radioactivity was not significantly different between the tracers. In normal animals, however, the uptake of [ 18 F]annexin V in the liver, spleen and kidney was much lower than that of [ 99m Tc]annexin V. The low uptake of [ 18 F]annexin V in these organs might represent an advantage over [ 99m Tc]annexin V. (orig.)