scholarly journals Imaging Salt Uptake Dynamics in Plants Using PET

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Gerard Ariño-Estrada ◽  
Gregory S. Mitchell ◽  
Prasenjit Saha ◽  
Ahmad Arzani ◽  
Simon R. Cherry ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Sodium Transport ◽  
Crop Production ◽  
Small Animal ◽  
Region Of Interest ◽  
Salt Transport ◽  
Small Animal Pet ◽  
Transport Dynamics ◽  
Positron Emission ◽  
Over Time

AbstractSoil salinity is a global environmental challenge for crop production. Understanding the uptake and transport properties of salt in plants is crucial to evaluate their potential for growth in high salinity soils and as a basis for engineering varieties with increased salt tolerance. Positron emission tomography (PET), traditionally used in medical and animal imaging applications for assessing and quantifying the dynamic bio-distribution of molecular species, has the potential to provide useful measurements of salt transport dynamics in an intact plant. Here we report on the feasibility of studying the dynamic transport of 22Na in millet using PET. Twenty-four green foxtail (Setaria viridis L. Beauv.) plants, 12 of each of two different accessions, were incubated in a growth solution containing 22Na+ ions and imaged at 5 time points over a 2-week period using a high-resolution small animal PET scanner. The reconstructed PET images showed clear evidence of sodium transport throughout the whole plant over time. Quantitative region-of-interest analysis of the PET data confirmed a strong correlation between total 22Na activity in the plants and time. Our results showed consistent salt transport dynamics within plants of the same variety and important differences between the accessions. These differences were corroborated by independent measurement of Na+ content and expression of the NHX transcript, a gene implicated in sodium transport. Our results demonstrate that PET can be used to quantitatively evaluate the transport of sodium in plants over time and, potentially, to discern differing salt-tolerance properties between plant varieties. In this paper, we also address the practical radiation safety aspects of working with 22Na in the context of plant imaging and describe a robust pipeline for handling and incubating plants. We conclude that PET is a promising and practical candidate technology to complement more traditional salt analysis methods and provide insights into systems-level salt transport mechanisms in intact plants.

scholarly journals NEMA NU4-2008 Performance Evaluation of Albira: A Two-Ring Small-Animal PET System Using Continuous LYSO Crystals

2016 ◽  
Vol 3 (1) ◽  
pp. 12-26 ◽  
Author(s):  
Malgorzata Z. Pajak ◽  
David Volgyes ◽  
Sally L. Pimlott ◽  
Carlos C. Salvador ◽  
Antonio S. Asensi ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Small Animal Imaging ◽  
Small Animal ◽  
Axial Direction ◽  
Small Animal Pet ◽  
Performance Review ◽  
Good Spatial Resolution ◽  
Positron Emission ◽  
Animal Images ◽  
Pet System

Goals:This paper presents the performance review based on a dual-ring Positron Emission Tomography (PET) scanner being a part of Bruker Albira: a multi-modal small-animal imaging platform. Each ring of Albira PET contains eight detectors arranged as octagon, and each detector is built using a single continuous lutetium-yttrium oxyorthosilicate crystal and multi-anode photo multiplier tube. In two-ring configuration, the scanner covers 94.4 mm in axial- and 80´80 mm in trans-axial direction, which is sufficient to acquire images of small animals (e.g.mice) without the need of moving the animal bed during the scan.Methods:All measurements and majority of data processing were performed according to the NEMA NU4-2008 standard with one exception. Due to the scanner geometry, the spatial resolution test was reconstructed using iterative algorithm instead of the analytical one. The main performance characteristics were compared with those of the other PET sub-systems of tri-modal small-animal scanners.Results:The measured spatial resolution at the centre of the axial field of view in radial, tangential and axial directions was 1.72, 1.70 and 2.45 mm, respectively. The scatter fraction for the mouse-like phantom was 9.8% and for the rat-like phantom, 21.8%. The maximum absolute sensitivity was 5.30%. Finally, the recovery co-efficients for 5, 4, 3, 2, 1 mm diameter rods in image quality phantom were: 0.90, 0.77, 0.66, 0.30 and 0.05, respectively.Conclusion:The Bruker Albira is a versatile small-animal multi-modal device that can be used for variety of studies. Overall the PET sub-system provides a good spatial resolution coupled with better-than average sensitivity and the ability to produce good quality animal images when administering low activities.

scholarly journals New 55Co-labeled Albumin-Binding Folate Derivatives as Potential PET Agents for Folate Receptor Imaging

2019 ◽  
Vol 12 (4) ◽  
pp. 166 ◽  
Author(s):  
Lauren L. Radford ◽  
Solana Fernandez ◽  
Rebecca Beacham ◽  
Retta El Sayed ◽  
Renata Farkas ◽  
...  
Keyword(s):  
Folate Receptor ◽  
Small Animal ◽  
Small Animal Pet ◽  
Receptor Imaging ◽  
Albumin Binding ◽  
Liver Uptake ◽  
Biodistribution Studies ◽  
Positron Emission

Overexpression of folate receptors (FRs) on different tumor types (e.g., ovarian, lung) make FRs attractive in vivo targets for directed diagnostic/therapeutic agents. Currently, no diagnostic agent suitable for positron emission tomography (PET) has been adopted for clinical FR imaging. In this work, two 55Co-labeled albumin-binding folate derivatives-[55Co]Co-cm10 and [55Co]Co-rf42-with characteristics suitable for PET imaging have been developed and evaluated. High radiochemical yields (≥95%) and in vitro stabilities (≥93%) were achieved for both compounds, and cell assays demonstrated FR-mediated uptake. Both 55Co-labeled folate conjugates demonstrated high tumor uptake of 17% injected activity per gram of tissue (IA/g) at 4 h in biodistribution studies performed in KB tumor-bearing mice. Renal uptake was similar to other albumin-binding folate derivatives, and liver uptake was lower than that of previously reported [64Cu]Cu-rf42. Small animal PET/CT images confirmed the biodistribution results and showed the clear delineation of FR-expressing tumors.

scholarly journals Radiosynthesis and Evaluation of Cyclohexyl (5-(2-[11C-Carbonyl]acetamidobenzo[d]thiazol-6-yl)-2-Methylpyridin-3-yl)Carbamate ([11C]PK68) As a New Radioligand For Imaging Receptor-Interacting Protein 1 Kinase

2022 ◽  
Author(s):  
Tomoteru Yamasaki ◽  
Katsushi Kumata ◽  
Atsuto Hiraishi ◽  
Yiding Zhang ◽  
Hidekatsu Wakizaka ◽  
...  
Keyword(s):  
Acetyl Chloride ◽  
Radiochemical Purity ◽  
Specific Binding ◽  
Small Animal ◽  
Small Animal Pet ◽  
Interacting Protein ◽  
Molar Activity ◽  
Positron Emission ◽  
Key Enzyme

Abstract Background: Receptor-interacting protein 1 kinase (RIPK1) is a key enzyme in the regulation of cellular necroptosis. Recently, cyclohexyl (5-(2-acetamidobenzo[d]thiazol-6-yl)-2-methylpyridin-3-yl)carbamate (PK68, 5) has been developed as a potent inhibitor of RIPK1. Herein, we radiosynthesized [11C]PK68 as a new positron emission tomography (PET) ligand for imaging RIPK1 and evaluated its potential in vivo.Results: We synthesized [11C]PK68 by reacting amine precursor 14 with [11C]acetyl chloride. At the end of synthesis, we obtained [11C]PK68 of 1200–1790 MBq (n = 10) with >99% radiochemical purity and a molar activity of 37–99 GBq/μmol starting from 18–33 GBq of [11C]CO2. The fully automated synthesis took 30 min from the end of irradiation. In a small-animal PET study, [11C]PK68 was rapidly distributed in the liver and kidneys of healthy mice after injection, and was subsequently cleared from their bodies via hepatobiliary excretion and the intestinal reuptake pathway. Although there was no obvious specific binding of RIPK1 in the PET study, [11C]PK68 demonstrated relatively high stability in vivo, and may be used as a lead compound for further candidate development.Conclusions: In the present study, we successfully radiosynthesized [11C]PK68 and evaluated its potential in vivo. We are planning to optimize the chemical structure of [11C]PK68 and conduct further PET studies on it using pathological models.

scholarly journals Influence of detectors efficiency normalization on small animal PET image quality

2019 ◽  
Vol 7 (3) ◽  
Author(s):  
Mateus Gesulado Carneiro De Santana ◽  
Guilherme Cavalcante de Albuquerque Souza ◽  
Rodrigo Modesto Gadelha Gontijo ◽  
Bruno Melo Mendes ◽  
Andréa Vidal Ferreira
Keyword(s):  
Image Quality ◽  
Image Acquisition ◽  
Small Animal ◽  
Quality Parameters ◽  
Small Animal Pet ◽  
Daily Routine ◽  
Positron Emission Tomograph ◽  
Software Update ◽  
Positron Emission ◽  
Compromise Image Quality

LabPET GE 4 (a small animal positron emission tomograph) image acquisition is done by 1536 independents channels. Differences in the rate counting of each channel must be corrected so as not compromise image quality. Equipment user manual recommends that normalization of the detectors efficiency be made as often as possible and always whenever there are hardware or software parameters changes - included, but not limited to channels parameters adjustments, electronic cards replacements, channels activation or inactivation or software update. This work evaluates the normalization effects on the image quality parameters. PET image acquisition were performed using recommended parameters by the NEMA NU 4-2008 standards. Image was reconstructed in different ways using different normalization files. The tests performed indicated that the image quality parameters do not vary significantly with different normalization data. Therefore, a daily routine of normalizations is not justified, suggesting a periodical frequency of one month or more for this procedure.

scholarly journals 18F-FIMP: a LAT1-specific PET probe for discrimination between tumor tissue and inflammation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Satoshi Nozaki ◽  
Yuka Nakatani ◽  
Aya Mawatari ◽  
Nina Shibata ◽  
William E. Hume ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Early Phase ◽  
Liver Microsomes ◽  
Small Animal ◽  
Absorbed Dose ◽  
Biological Evaluation ◽  
Small Animal Pet ◽  
Positron Emission ◽  
Tumor Tissues

Abstract Positron emission tomography (PET) imaging can assist in the early-phase diagnostic and therapeutic evaluation of tumors. Here, we report the radiosynthesis, small animal PET imaging, and biological evaluation of a L-type amino acid transporter 1 (LAT1)-specific PET probe, 18F-FIMP. This probe demonstrates increased tumor specificity, compared to existing tumor-specific PET probes (18F-FET, 11C-MET, and 18F-FDG). Evaluation of probes by in vivo PET imaging, 18F-FIMP showed intense accumulation in LAT1-positive tumor tissues, but not in inflamed lesions, whereas intense accumulation of 18F-FDG was observed in both tumor tissues and in inflamed lesions. Metabolite analysis showed that 18F-FIMP was stable in liver microsomes, and mice tissues (plasma, urine, liver, pancreas, and tumor). Investigation of the protein incorporation of 18F-FIMP showed that it was not incorporated into protein. Furthermore, the expected mean absorbed dose of 18F-FIMP in humans was comparable or slightly higher than that of 18F-FDG and indicated that 18F-FIMP may be a safe PET probe for use in humans. 18F-FIMP may provide improved specificity for tumor diagnosis, compared to 18F-FDG, 18F-FET, and 11C-MET. This probe may be suitable for PET imaging for glioblastoma and the early-phase monitoring of cancer therapy outcomes.

PET study of 11C-acetoacetate kinetics in rat brain during dietary treatments affecting ketosis

2009 ◽  
Vol 296 (4) ◽  
pp. E796-E801 ◽  
Author(s):  
M'hamed Bentourkia ◽  
Sébastien Tremblay ◽  
Fabien Pifferi ◽  
Jacques Rousseau ◽  
Roger Lecomte ◽  
...  
Keyword(s):  
Ketogenic Diet ◽  
Pet Imaging ◽  
Control Diet ◽  
Small Animal ◽  
Liver Mitochondria ◽  
Small Animal Pet ◽  
Clinical Effects ◽  
Brain Uptake ◽  
Positron Emission ◽  
The Brain

Normally, the brain's fuel is glucose, but during fasting it increasingly relies on ketones (β-hydroxybutyrate, acetoacetate, and acetone) produced in liver mitochondria from fatty acid β-oxidation. Although moderately raised blood ketones produced on a very high fat ketogenic diet have important clinical effects on the brain, including reducing seizures, ketone metabolism by the brain is still poorly understood. The aim of the present work was to assess brain uptake of carbon-11-labeled acetoacetate (11C-acetoacetate) by positron emission tomography (PET) imaging in the intact, living rat. To vary plasma ketones, we used three dietary conditions: high carbohydrate control diet (low plasma ketones), fat-rich ketogenic diet (raised plasma ketones), and 48-h fasting (raised plasma ketones). 11C-acetoacetate metabolism was measured in the brain, heart, and tissue in the mouth area. Using 11C-acetoacetate and small animal PET imaging, we have noninvasively quantified an approximately seven- to eightfold enhanced brain uptake of ketones on a ketogenic diet or during fasting. This opens up an opportunity to study brain ketone metabolism in humans.

scholarly journals Influence of image reconstruction protocols on the image quality of a small animal PET scanner using 18F and 11C

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
João Vitor do Carmo Barbosa ◽  
Rodrigo Modesto Gadelha Gontijo ◽  
Guilherme Cavalcante de Albuquerque Souza ◽  
Bruno Melo Mendes ◽  
Juliana Batista da Silva ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Image Quality ◽  
Iterative Algorithms ◽  
Small Animal ◽  
High Standard ◽  
Small Animal Pet ◽  
Mean Values ◽  
Positron Emission ◽  
Novel Applications ◽  
Number Of Iterations

The small animal positron emission tomography (PET) scanner from Molecular Imaging Laboratory (LIM/CDTN) is dedicated to pre-clinical studies on new 18F and 11C-based radiopharmaceuticals and to development of novel applications for well-known radiopharmaceuticals. Thus, quality control tests recommended by the publication NEMA NU 4-2008 are routinely carried out to ensure the proper performance of PET scanner. The aim of this work was to evaluate the influence of image reconstruction protocols on the image quality, accuracy of attenuation and scatter corrections parameters for 18F and 11C PET images. PET images of the image quality phantom filed with 18F-FDG or 11C-PK1122 were acquired and then reconstructed using different reconstruction protocols. The reconstruction variables evaluated were the algorithms (FBP, MLEM-3D, OSEM-3D), the resolution mode (high/standard) and the number of iterations (10 to 150). Uniformity, spill-over ratio (SOR) and recovery coefficients (RC) tests were performed for each reconstructed image according NEMA NU 4-2008. PMOD software was used for image analysis. FBP based protocol generated noisier images compared to iterative algorithms (MLEM-3D or OSEM-3D) based protocols. The increase in the number of iterations resulted in higher standard deviation of the analyzed parameters for all reconstructed images. MLEM-3D and OSEM-3D based protocols generates similar results when number of iterations and resolution mode were identical. SOR and RC mean values remained stable when the number of iterations ranged from 40 to 150. This study allowed the evaluation of different image reconstruction protocols on important parameters of 18F and 11C PET image quality. Additionally, standard image reconstruction protocols to be adopted in LIM/CDTN laboratorial routine for 18F and 11C images reconstruction in preclinical studies were defined.

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

2016 ◽  
Vol 22 (3) ◽  
pp. 69-75 ◽  
Author(s):  
Khadidja Berradja ◽  
Nabil Boughanmi
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Metabolic Rate ◽  
Small Animal ◽  
Region Of Interest ◽  
Input Function ◽  
Small Animal Pet ◽  
Animal Pet ◽  
Significant Difference

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

Sign in / Sign up

Export Citation Format

Share Document