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 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.

Image quality evaluation of a small animal PET scanner

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Andréa Vidal Ferreira ◽  
Rodrigo Modesto Gadelha Gontijo ◽  
Guilherme Cavalcante de Albuquerque Souza ◽  
Bruno Melo Mendes ◽  
Juliana Batista da Silva ◽  
...  
Keyword(s):  
Image Quality ◽  
Quality Evaluation ◽  
Small Animal ◽  
Small Animal Pet ◽  
Image Quality Evaluation ◽  
Animal Pet

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.

Cold wall effect eliminating method to determine the contrast recovery coefficient for small animal PET scanners using the NEMA NU-4 image quality phantom

2014 ◽  
Vol 59 (11) ◽  
pp. 2727-2746 ◽  
Author(s):  
Imre Lajtos ◽  
Johannes Czernin ◽  
Magnus Dahlbom ◽  
Freddie Daver ◽  
Miklos Emri ◽  
...  
Keyword(s):  
Image Quality ◽  
Small Animal ◽  
Wall Effect ◽  
Small Animal Pet ◽  
Cold Wall ◽  
Recovery Coefficient ◽  
Animal Pet ◽  
Pet Scanners

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.

A GPU-accelerated fully 3D OSEM image reconstruction for a high-resolution small animal PET scanner using dual-ended readout detectors

2020 ◽  
Vol 65 (24) ◽  
pp. 245007 ◽  
Author(s):  
Tianyi Zeng ◽  
Juan Gao ◽  
Dongfang Gao ◽  
Zhonghua Kuang ◽  
Ziru Sang ◽  
...  
Keyword(s):  
High Resolution ◽  
Image Reconstruction ◽  
Small Animal ◽  
Small Animal Pet ◽  
Animal Pet
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