scholarly journals In Vivo Positron Emission Tomography (PET) Imaging with an αvβ6Specific Peptide Radiolabeled using18F-“Click” Chemistry: Evaluation and Comparison with the Corresponding 4-[18F]Fluorobenzoyl- and 2-[18F]Fluoropropionyl-Peptides

2008 ◽  
Vol 51 (19) ◽  
pp. 5901-5904 ◽  
Author(s):  
Sven H. Hausner ◽  
Jan Marik ◽  
M. Karen J. Gagnon ◽  
Julie L. Sutcliffe
Keyword(s):  
Positron Emission Tomography ◽  
Click Chemistry ◽  
Pet Imaging ◽  
Emission Tomography ◽  
Positron Emission

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 For that purpose, a gamma spectroscopic analysis is performed on blood samples manually withdrawn from the patient when at least one of the co-injected tracers is based on a non-pure positron emitter.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 Imaging Cardiovascular and Lung Macrophages With the Positron Emission Tomography Sensor 64 Cu-Macrin in Mice, Rabbits, and Pigs

2020 ◽  
Vol 13 (10) ◽  
Author(s):  
Matthias Nahrendorf ◽  
Friedrich Felix Hoyer ◽  
Anu E. Meerwaldt ◽  
Mandy M.T. van Leent ◽  
Max L. Senders ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Flow Cytometry ◽  
Confocal Microscopy ◽  
Pet Imaging ◽  
Near Infrared ◽  
Emission Tomography ◽  
Imaging Biomarker ◽  
Positron Emission ◽  
Pulmonary Macrophages

Background: Macrophages, innate immune cells that reside in all organs, defend the host against infection and injury. In the heart and vasculature, inflammatory macrophages also enhance tissue damage and propel cardiovascular diseases. Methods: We here use in vivo positron emission tomography (PET) imaging, flow cytometry, and confocal microscopy to evaluate quantitative noninvasive assessment of cardiac, arterial, and pulmonary macrophages using the nanotracer 64 Cu-Macrin—a 20-nm spherical dextran nanoparticle assembled from nontoxic polyglucose. Results: PET imaging using 64 Cu-Macrin faithfully reported accumulation of macrophages in the heart and lung of mice with myocardial infarction, sepsis, or pneumonia. Flow cytometry and confocal microscopy detected the near-infrared fluorescent version of the nanoparticle ( VT680 Macrin) primarily in tissue macrophages. In 5-day-old mice, 64 Cu-Macrin PET imaging quantified physiologically more numerous cardiac macrophages. Upon intravenous administration of 64 Cu-Macrin in rabbits and pigs, we detected heightened macrophage numbers in the infarcted myocardium, inflamed lung regions, and atherosclerotic plaques using a clinical PET/magnetic resonance imaging scanner. Toxicity studies in rats and human dosimetry estimates suggest that 64 Cu-Macrin is safe for use in humans. Conclusions: Taken together, these results indicate 64 Cu-Macrin could serve as a facile PET nanotracer to survey spatiotemporal macrophage dynamics during various physiological and pathological conditions. 64 Cu-Macrin PET imaging could stage inflammatory cardiovascular disease activity, assist disease management, and serve as an imaging biomarker for emerging macrophage-targeted therapeutics.

Direct Observation of Hydroxyapatite Nanoparticles In Vivo

2012 ◽  
Vol 503-504 ◽  
pp. 688-691 ◽  
Author(s):  
Wei Zhou ◽  
Jun Zheng
Keyword(s):  
Positron Emission Tomography ◽  
Real Time ◽  
Pet Imaging ◽  
Three Dimensional ◽  
Transverse Plane ◽  
Emission Tomography ◽  
Hydroxyapatite Nanoparticles ◽  
Positron Emission ◽  
Dimensional Reconstruction

While nano-hydroxyapatite (nano-HAP) has been well known for series of amazing properties in chemical or physical, the controversy on the risks of its applications has also been existed. The worries of nano-HAP applications in preclinic and clinic indicate the blank researches of nano-HAP pharmacodynamics. It is important and necessary to trace and clarify the localizations of HAP nanoparticles in vivo. In the present paper, 18F is used as radiotracer for Positron Emission Tomography (PET) imaging of HAP nanoparticles. Through the transverse plane slices and three-dimensional reconstruction pictures, it is very clear to observe the localization of nano-HAP in vivo at real time. Most nano-HAP particles were noted in organs lump, liver, spleen, stomach and existed for period of time. Therefore, PET can be a new powerful technique for tracing nano-biomaterial and their pharmacodynamics researches.

scholarly journals An activatable PET imaging radioprobe is a dynamic reporter of myeloperoxidase activity in vivo

2019 ◽  
pp. 201818434 ◽  
Author(s):  
Cuihua Wang ◽  
Edmund Keliher ◽  
Matthias W. G. Zeller ◽  
Gregory R. Wojtkiewicz ◽  
Aaron D. Aguirre ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Competitive Inhibition ◽  
Emission Tomography ◽  
Myeloperoxidase Activity ◽  
Positron Emission ◽  
Emerging Therapies ◽  
Rheumatological Diseases

Myeloperoxidase (MPO) is a critical proinflammatory enzyme implicated in cardiovascular, neurological, and rheumatological diseases. Emerging therapies targeting inflammation have raised interest in tracking MPO activity in patients. We describe18F-MAPP, an activatable MPO activity radioprobe for positron emission tomography (PET) imaging. The activated radioprobe binds to proteins and accumulates at sites of MPO activity. The radioprobe18F-MAPP has a short blood half-life, remains stable in plasma, does not demonstrate cytotoxicity, and crosses the intact blood–brain barrier. The18F-MAPP imaging detected sites of elevated MPO activity in living mice embedded with human MPO and in mice induced with chemical inflammation or myocardial infarction. The18F-MAPP PET imaging noninvasively differentiated varying amounts of MPO activity, competitive inhibition, and MPO deficiency in living animals, confirming specificity and showing that the radioprobe can quantify changes in in vivo MPO activity. The radiosynthesis has been optimized and automated, an important step in translation. These data indicate that18F-MAPP is a promising translational candidate to noninvasively monitor MPO activity and inflammation in patients.

scholarly journals Imaging of Serotonin Mechanisms in Epilepsy

2005 ◽  
Vol 5 (6) ◽  
pp. 201-206 ◽  
Author(s):  
Harry T. Chugani ◽  
Diane C. Chugani
Keyword(s):  
Positron Emission Tomography ◽  
Surgical Treatment ◽  
Pet Imaging ◽  
Serotonin Receptors ◽  
Emission Tomography ◽  
Human Epilepsy ◽  
Positron Emission ◽  
Epilepsy Treatment ◽  
Neurotransmitter Synthesis

Advances in positron emission tomography (PET) techniques have allowed the measurement and imaging of neurotransmitter synthesis, transport, and receptor binding to be performed in vivo. With regard to epileptic disorders, imaging of neurotransmitter systems not only assists in the identification of epileptic foci for surgical treatment, but also provides insights into the basic mechanisms of human epilepsy. Recent investigative interest in epilepsy has focused on PET imaging of tryptophan metabolism, via the serotonin and kynurenine pathways, as well as on imaging of serotonin receptors. This review summarizes advances in PET imaging and how these techniques can be applied clinically for epilepsy treatment.

scholarly journals In Vivo Imaging of Hypoxia and Neoangiogenesis in Experimental Syngeneic Hepatocellular Carcinoma Tumor Model Using Positron Emission Tomography

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Adrienn Kis ◽  
Judit P. Szabó ◽  
Noémi Dénes ◽  
Adrienn Vágner ◽  
Gábor Nagy ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Tumor Model ◽  
Temporal Changes ◽  
Receptor Expression ◽  
Emission Tomography ◽  
Positron Emission ◽  
Angiogenic Markers

Introduction. Hypoxia-induced ανβ3 integrin and aminopeptidase N (APN/CD13) receptor expression play an important role in tumor neoangiogenesis. APN/CD13-specific 68Ga-NOTA-c(NGR), ανβ3 integrin-specific 68Ga-NODAGA-[c(RGD)]2, and hypoxia-specific 68Ga-DOTA-nitroimidazole enable the in vivo detection of the neoangiogenic process and the hypoxic regions in the tumor mass using positron emission tomography (PET) imaging. The aim of this study was to evaluate whether 68Ga-NOTA-c(NGR) and 68Ga-DOTA-nitroimidazole allow the in vivo noninvasive detection of the temporal changes of APN/CD13 expression and hypoxia in experimental He/De tumors using positron emission tomography. Materials and Methods. 5×106 hepatocellular carcinoma (He/De) cells were used for the induction of a subcutaneous tumor model in Fischer-344 rats. He/De tumor-bearing animals were anaesthetized, and 90 min after intravenous injection of 10.2±1.1 MBq 68Ga-NOTA-c(NGR) or 68Ga-NODAGA-[c(RGD)]2 (as angiogenesis tracers) or 68Ga-DOTA-nitroimidazole (for hypoxia imaging), whole-body PET/MRI scans were performed. Results. Hypoxic regions and angiogenic markers (αvβ3 integrin and APN/CD13) were determined using 68Ga-NOTA-c(NGR), 68Ga-DOTA-nitroimidazole, and 68Ga-NODAGA-[c(RGD)]2 in subcutaneously growing He/De tumors in rats. 68Ga-NOTA-c(NGR) showed the strong APN/CD13 positivity of He/De tumors in vivo, by which observation was confirmed by western blot analysis. By the qualitative analysis of PET images, heterogenous accumulation was found inside He/De tumors using all radiotracers. Significantly (p≤0.01) higher SUVmean and SUVmax values were found in the radiotracer avid regions of the tumors than those of the nonavid areas using hypoxia and angiogenesis-specific radiopharmaceuticals. Furthermore, a strong correlation was found between the presence of angiogenic markers, the appearance of hypoxic regions, and the tumor volume using noninvasive in vivo PET imaging. Conclusion. 68Ga-DOTA-nitroimidazole and 68Ga-NOTA-c(NGR) are suitable diagnostic radiotracers for the detection of the temporal changes of hypoxic areas and neoangiogenic molecule (CD13) expression, which vary during tumor growth in a hepatocellular carcinoma model.

Quantitative micro positron emission tomography (PET) imaging for the in vivo determination of pancreatic islet graft survival

2006 ◽  
Vol 12 (12) ◽  
pp. 1423-1428 ◽  
Author(s):  
Su-Jin Kim ◽  
Doris J Doudet ◽  
Andrei R Studenov ◽  
Cuilan Nian ◽  
Thomas J Ruth ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Graft Survival ◽  
Pancreatic Islet ◽  
Pet Imaging ◽  
Emission Tomography ◽  
Islet Graft ◽  
Positron Emission

scholarly journals Analysis of 18 F-Sodium Fluoride Positron Emission Tomography Signal Sources in Atherosclerotic Minipigs Shows Specific Binding of 18 F-Sodium Fluoride to Plaque Calcifications

2021 ◽  
Author(s):  
Paula Nogales ◽  
Carlos Velasco ◽  
Adriana Mota-Cobián ◽  
Leticia González-Cintado ◽  
Rubén Avelino Mota ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Sodium Fluoride ◽  
Abdominal Aorta ◽  
Pet Imaging ◽  
Ex Vivo ◽  
Emission Tomography ◽  
Iliac Arteries ◽  
Positron Emission

Objective: 18 F-sodium fluoride ( 18 F-NaF) positron emission tomography (PET) imaging is thought to visualize active atherosclerotic plaque calcification. This is supported by the binding of 18 F-NaF to plaque calcification ex vivo, but no prior studies have examined binding of 18 F-NaF to human-like plaque in vivo. Our aim was to validate the specificity of 18 F-NaF PET for plaque calcifications in atherosclerotic minipigs. Approach and Results: Gain-of-function PCSK9 D374Y (proprotein convertase/subtilisin kexin type 9) transgenic Yucatan minipigs (n=4) were fed high-fat diet for 2.5 years to develop atherosclerosis and then subjected to 18 F-NaF PET/computed tomography imaging. The heart, aorta, and iliac arteries were immediately re-scanned ex vivo after surgical extraction. Lesions from the abdominal aorta, iliac arteries, and coronary arteries were cryo-sectioned for autoradiography. Histological plaque characteristics, PET/computed tomography signal, and autoradiography were linked through regression and co-localization analysis. Arterial 18 F-NaF PET signal had intensities comparable to clinical scans and colocalized moderately with calcification detected by computed tomography. Histological analysis showed calcification spanning from microcalcifications near lipid pools and necrotic core to more homogenous macrocalcifications. Comparison with arteries from autopsy cases confirmed the resemblance in localization and appearance with early human plaque calcification. Regression analysis in the abdominal aorta showed correlations with calcified plaque but could not rule out contributions from noncalcified plaque. This was resolved by autoradiography, which showed specific accumulation in plaque calcifications in all examined arteries. In the context of porcine abdominal aorta, 18 F-NaF PET imaging was, however, less accurate than computed tomography for detecting small calcifications. Conclusions: 18 F-NaF accumulates specifically in calcifications of atherosclerotic plaques in vivo.

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