scholarly journals Direct Aromatic 18F-Labeling of Highly Reactive Tetrazines for Pretargeted Bioorthogonal PET Imaging

2021 ◽  
Author(s):  
Rocio García-Vázquez ◽  
Umberto Maria Battisti ◽  
Jesper Tranekjær Jørgensen ◽  
Vladimir Shalgunov ◽  
Lars Hvass ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Emission Tomography ◽  
Positron Emission

Pretargeted imaging can be used to visualize and quantify slow accumulating targeting vectors with short-lived radionuclides such as fluorine-18 - the most clinically applied Positron Emission Tomography (PET) radionuclide. Pretargeting...

Usefulness of positron emission tomography for differentiating gliomas according to the 2016 World Health Organization classification of tumors of the central nervous system

2020 ◽  
Vol 133 (4) ◽  
pp. 1010-1019 ◽  
Author(s):  
Hiroaki Takei ◽  
Jun Shinoda ◽  
Soko Ikuta ◽  
Takashi Maruyama ◽  
Yoshihiro Muragaki ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Who Classification ◽  
Standardized Uptake Value ◽  
Emission Tomography ◽  
World Health ◽  
Pet Tracers ◽  
Positron Emission ◽  
Significant Difference ◽  
The Mean

OBJECTIVEPositron emission tomography (PET) is important in the noninvasive diagnostic imaging of gliomas. There are many PET studies on glioma diagnosis based on the 2007 WHO classification; however, there are no studies on glioma diagnosis using the new classification (the 2016 WHO classification). Here, the authors investigated the relationship between uptake of 11C-methionine (MET), 11C-choline (CHO), and 18F-fluorodeoxyglucose (FDG) on PET imaging and isocitrate dehydrogenase (IDH) status (wild-type [IDH-wt] or mutant [IDH-mut]) in astrocytic and oligodendroglial tumors according to the 2016 WHO classification.METHODSIn total, 105 patients with newly diagnosed cerebral gliomas (6 diffuse astrocytomas [DAs] with IDH-wt, 6 DAs with IDH-mut, 7 anaplastic astrocytomas [AAs] with IDH-wt, 24 AAs with IDH-mut, 26 glioblastomas [GBMs] with IDH-wt, 5 GBMs with IDH-mut, 19 oligodendrogliomas [ODs], and 12 anaplastic oligodendrogliomas [AOs]) were included. All OD and AO patients had both IDH-mut and 1p/19q codeletion. The maximum standardized uptake value (SUV) of the tumor/mean SUV of normal cortex (T/N) ratios for MET, CHO, and FDG were calculated, and the mean T/N ratios of DA, AA, and GBM with IDH-wt and IDH-mut were compared. The diagnostic accuracy for distinguishing gliomas with IDH-wt from those with IDH-mut was assessed using receiver operating characteristic (ROC) curve analysis of the mean T/N ratios for the 3 PET tracers.RESULTSThere were significant differences in the mean T/N ratios for all 3 PET tracers between the IDH-wt and IDH-mut groups of all histological classifications (p < 0.001). Among the 27 gliomas with mean T/N ratios higher than the cutoff values for all 3 PET tracers, 23 (85.2%) were classified into the IDH-wt group using ROC analysis. In DA, there were no significant differences in the T/N ratios for MET, CHO, and FDG between the IDH-wt and IDH-mut groups. In AA, the mean T/N ratios of all 3 PET tracers in the IDH-wt group were significantly higher than those in the IDH-mut group (p < 0.01). In GBM, the mean T/N ratio in the IDH-wt group was significantly higher than that in the IDH-mut group for both MET (p = 0.034) and CHO (p = 0.01). However, there was no significant difference in the ratio for FDG.CONCLUSIONSPET imaging using MET, CHO, and FDG was suggested to be informative for preoperatively differentiating gliomas according to the 2016 WHO classification, particularly for differentiating IDH-wt and IDH-mut tumors.

Role of Positron Emission Tomography for Central Nervous System Involvement in Systemic Autoimmune Diseases: Status and Perspectives

2018 ◽  
Vol 25 (26) ◽  
pp. 3096-3104 ◽  
Author(s):  
Daniele Mauro ◽  
Gaetano Barbagallo ◽  
Salvatore D`Angelo ◽  
Pasqualina Sannino ◽  
Saverio Naty ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Central Nervous System ◽  
Nervous System ◽  
Autoimmune Diseases ◽  
Pet Imaging ◽  
Emission Tomography ◽  
Cns Involvement ◽  
Systemic Autoimmune Diseases ◽  
Positron Emission

In the last years, an increasing interest in molecular imaging has been raised by the extending potential of positron emission tomography [PET]. The role of PET imaging, originally confined to the oncology setting, is continuously extending thanks to the development of novel radiopharmaceutical and to the implementation of hybrid imaging techniques, where PET scans are combined with computed tomography [CT] or magnetic resonance imaging[MRI] in order to improve spatial resolution. Early preclinical studies suggested that 18F–FDG PET can detect neuroinflammation; new developing radiopharmaceuticals targeting more specifically inflammation-related molecules are moving in this direction. Neurological involvement is a distinct feature of various systemic autoimmune diseases, i.e. Systemic Lupus Erythematosus [SLE] or Behcet’s disease [BD]. Although MRI is largely considered the gold-standard imaging technique for the detection of Central Nervous System [CNS] involvement in these disorders. Several patients complain of neuropsychiatric symptoms [headache, epilepsy, anxiety or depression] in the absence of any significant MRI finding; in such patients the diagnosis relies mainly on clinical examination and often the role of the disease process versus iatrogenic or reactive forms is doubtful. The aim of this review is to explore the state-of-the-art for the role of PET imaging in CNS involvement in systemic rheumatic diseases. In addition, we explore the potential role of emerging radiopharmaceutical and their possible application in aiding the diagnosis of CNS involvement in systemic autoimmune diseases.

Direct incorporation of [ 18F] into aliphatic systems: A promising Mncatalysed labelling technique for PET imaging

2020 ◽  
Vol 13 ◽  
Author(s):  
Sara Cesarec ◽  
Jonathan A. Robson ◽  
Laurence S. Carroll ◽  
Eric O. Aboagye ◽  
Alan C. Spivey
Keyword(s):  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Emission Tomography ◽  
Labelling Technique ◽  
Porphyrin Complex ◽  
Mild Conditions ◽  
Drug Substances ◽  
Positron Emission ◽  
Site Selective ◽  
Direct Incorporation

Background: One of the challenges in positron emission tomography (PET) is labelling complex aliphatic molecules. Objective: To develop a method of metal-catalysed radiofluorination that is site-selective and works in moderate to good yields under facile conditions. Methods: We report here on the optimisation of an aliphatic C-H to C-18F bond transformation catalysed by a Mn(porphyrin) complex. Results: The successful oxidation of 11 aliphatic molecules including progesterone are reported. Radiochemical Incorporations (RCIs) up to 69% were achieved within 60 min without the need for pre-activation or specialist equipment. Conclusion: The method features mild conditions (60 °C) and promises to constitute a valuable approach to labelling of biomolecules and drug substances.

scholarly journals Development of a blood sample detector for multi-tracer positron emission tomography using gamma spectroscopy

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Carlos Velasco ◽  
Adriana Mota-Cobián ◽  
Jesús Mateo ◽  
Samuel España
Keyword(s):  
Positron Emission Tomography ◽  
Blood Sample ◽  
Pet Imaging ◽  
Spectroscopic Analysis ◽  
Gamma Spectroscopy ◽  
Emission Tomography ◽  
Blood Samples ◽  
Positron Emission

Abstract Background Multi-tracer positron emission tomography (PET) imaging can be accomplished by applying multi-tracer compartment modeling. Recently, a method has been proposed in which the arterial input functions (AIFs) of the multi-tracer PET scan are explicitly derived. For that purpose, a gamma spectroscopic analysis is performed on blood samples manually withdrawn from the patient when at least one of the co-injected tracers is based on a non-pure positron emitter. Alternatively, these blood samples required for the spectroscopic analysis may be obtained and analyzed on site by an automated detection device, thus minimizing analysis time and radiation exposure of the operating personnel. In this work, a new automated blood sample detector based on silicon photomultipliers (SiPMs) for single- and multi-tracer PET imaging is presented, characterized, and tested in vitro and in vivo. Results The detector presented in this work stores and analyzes on-the-fly single and coincidence detected events. A sensitivity of 22.6 cps/(kBq/mL) and 1.7 cps/(kBq/mL) was obtained for single and coincidence events respectively. An energy resolution of 35% full-width-half-maximum (FWHM) at 511 keV and a minimum detectable activity of 0.30 ± 0.08 kBq/mL in single mode were obtained. The in vivo AIFs obtained with the detector show an excellent Pearson’s correlation (r = 0.996, p < 0.0001) with the ones obtained from well counter analysis of discrete blood samples. Moreover, in vitro experiments demonstrate the capability of the detector to apply the gamma spectroscopic analysis on a mixture of 68Ga and 18F and separate the individual signal emitted from each one. Conclusions Characterization and in vivo evaluation under realistic experimental conditions showed that the detector proposed in this work offers excellent sensibility and stability. The device also showed to successfully separate individual signals emitted from a mixture of radioisotopes. Therefore, the blood sample detector presented in this study allows fully automatic AIFs measurements during single- and multi-tracer PET studies.

scholarly journals Incremental prognostic value of visually estimated coronary artery calcium in patients undergoing positron emission tomography imaging

Open Heart ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. e001648
Author(s):  
Senthil Selvaraj ◽  
Muhammad Shoaib Khan ◽  
Mahesh K Vidula ◽  
Philip C Wiener ◽  
Alejandro E de Feria ◽  
...  
Keyword(s):  
Risk Factors ◽  
Positron Emission Tomography ◽  
Coronary Artery ◽  
Pet Imaging ◽  
Prognostic Value ◽  
Primary Outcome ◽  
Chest Ct ◽  
Emission Tomography ◽  
Positron Emission ◽  
Traditional Risk Factors

ObjectiveVisually estimated coronary artery calcium (VECAC) from chest CT or attenuation correction (AC)/CT obtained during positron emission tomography (PET)–myocardial perfusion imaging (MPI) is feasible. Our aim was to determine the prognostic value of VECAC beyond conventional risk factors and PET imaging parameters, including coronary flow reserve (CFR).MethodsWe analysed 608 patients without known coronary artery disease who underwent PET–MPI between 2012 and 2016 and had AC/CT and/or chest CT images. We used Cox regression to estimate the association of VECAC categories (≤10, 11–400, >400 Agatston units (AU)) with the primary outcome of all-cause death, acute coronary syndrome or stroke (mean follow-up 4.3±1.8 years). C-statistics assessed the relationship between PET parameters and VECAC with the primary outcome.ResultsMean age was 58±11 years, 65% were women and 67% were black. VECAC ≤10, 11–400 and >400 AU was observed in 68%, 12% and 20% of subjects, respectively. Compared with VECAC ≤10, VECAC categories 11–400 (HR 2.25, 95% CI 1.24 to 4.08) and >400 AU (HR 3.05, 95% CI 1.87 to 4.98) were associated with the primary outcome after adjusting for traditional risk factors, MPI findings and CFR. Adding VECAC to a model that included PET–MPI, CFR and clinical risk factors improved the prognostic value for the primary outcomes (c-statistic 0.71 to 0.75 with VECAC, p=0.01).ConclusionsVECAC is a potent predictor of events beyond traditional risk factors and PET imaging markers, including CFR. These data further support the importance for routine VECAC implementation.

scholarly journals Positron emission tomography reporter gene strategy for use in the central nervous system

2019 ◽  
Vol 116 (23) ◽  
pp. 11402-11407 ◽  
Author(s):  
Tom Haywood ◽  
Corinne Beinat ◽  
Gayatri Gowrishankar ◽  
Chirag B. Patel ◽  
Israt S. Alam ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Central Nervous System ◽  
Nervous System ◽  
Reporter Gene ◽  
Pet Imaging ◽  
Emission Tomography ◽  
Great Promise ◽  
Adeno Associated Virus ◽  
Positron Emission ◽  
The Central Nervous System

There is a growing need for monitoring or imaging gene therapy in the central nervous system (CNS). This can be achieved with a positron emission tomography (PET) reporter gene strategy. Here we report the development of a PET reporter gene system using the PKM2 gene with its associated radiotracer [18F]DASA-23. The PKM2 reporter gene was delivered to the brains of mice by adeno-associated virus (AAV9) via stereotactic injection. Serial PET imaging was carried out over 8 wk to assess PKM2 expression. After 8 wk, the brains were excised for further mRNA and protein analysis. PET imaging at 8 wk post-AAV delivery showed an increase in [18F]DASA-23 brain uptake in the transduced site of mice injected with the AAV mice over all controls. We believe PKM2 shows great promise as a PET reporter gene and to date is the only example that can be used in all areas of the CNS without breaking the blood–brain barrier, to monitor gene and cell therapy.

scholarly journals Positron emission tomography (PET) imaging of neuroblastoma and melanoma with 64Cu-SarAr immunoconjugates

2007 ◽  
Vol 104 (44) ◽  
pp. 17489-17493 ◽  
Author(s):  
S. D. Voss ◽  
S. V. Smith ◽  
N. DiBartolo ◽  
L. J. McIntosh ◽  
E. M. Cyr ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Emission Tomography ◽  
Positron Emission

Positron Emission Tomography (PET) for Flow Measurement

2011 ◽  
Vol 301-303 ◽  
pp. 1316-1321 ◽  
Author(s):  
Arthur E. Ruggles ◽  
Bi Yao Zhang ◽  
Spero M. Peters
Keyword(s):  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Three Dimensional ◽  
Bulk Water ◽  
Emission Tomography ◽  
Optical Methods ◽  
Imaging Method ◽  
Analysis And Design ◽  
Pet Tracer ◽  
Positron Emission

Positron Emission Tomography (PET) produces a three dimensional spatial distribution of positron-electron annihilations within an image volume. Various positron emitters are available for use in aqueous, organic and liquid metal flows. Preliminary experiments at the University of Tennessee at Knoxville (UTK) injected small flows of PET tracer into a bulk water flow in a four rod bundle. The trajectory and diffusion of the tracer in the bulk flow were then mapped using a PET scanner. A spatial resolution of 1.4 mm is achieved with current preclinical Micro-PET imaging equipment resulting in 200 MB 3D activity fields. A time resolved 3-D spatial activity profile was also measured. The PET imaging method is especially well suited to complex geometries where traditional optical methods such as LDV and PIV are difficult to apply. PET methods are uniquely useful for imaging in opaque fluids, opaque pressure boundaries, and multiphase studies. Several commercial and shareware Computational Fluid Dynamics (CFD) codes are currently used for science and engineering analysis and design. These codes produce detailed three dimensional flow predictions. The models produced by these codes are often difficult to validate. The development of this experimental technique offers a modality for the comparison of CFD outcomes with experimental data. Developed data sets from PET can be used in verification and validation exercises of simulation outcomes.

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