scholarly journals Comparison of scandium-44 g with other PET radionuclides in pre-clinical PET phantom imaging

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Simon Ferguson ◽  
Hans-Sonke Jans ◽  
Melinda Wuest ◽  
Terence Riauka ◽  
Frank Wuest
Keyword(s):  
Image Quality ◽  
Expectation Maximization ◽  
Small Animal ◽  
Quality Parameters ◽  
Small Animal Pet ◽  
A Posteriori ◽  
Reconstruction Algorithms ◽  
Phantom Measurements ◽  
Theranostic Applications ◽  
Imaging Conditions

Abstract Purpose The decay characteristics of radionuclides in PET studies can impact image reconstruction. 44gSc has been the topic of recent research due to potential theranostic applications and is a promising radiometal for PET imaging. In this study, the reconstructed images from phantom measurements with scandium in a small-animal PET scanner are compared with 18F and two prominent radiometals: 64Cu and 68Ga Methods Three phantoms filled with 18F, 64C, 68Ga, and 44gSc were imaged in the Siemens Inveon PET scanner. The NEMA image quality phantom was used to determine the recovery coefficients (RCs), spill-over ratios (SORs), and noise (%SD) under typical pre-clinical imaging conditions. Image contrast was determined using a Derenzo phantom, while the coincidence characteristics were investigated using an NEC phantom. Three reconstruction algorithms were used, namely filtered back projection (FBP), ordered subset expectation maximization (OSEM), and maximum a-posteriori (MAP). Results Image quality parameters were measured for 18F, 64Cu, 68Ga, and 44gSc respectively; using FBP, the %SD are 5.65, 5.88, 7.28, and 7.70; the RCs for the 5-mm rod are 0.849, 1.01, 0.615, and 0.825; the SORs in water are 0.0473, 0.0595, 0.141, 0.0923; and the SORs in air are 0.0589, 0.0484, 0.0525, and 0.0509. The contrast measured in the 2.5-mm rods are 0.674, 0.637, 0.196, and 0.347. The NEC rate with 44gSc increased at a slower rate than 18F and 68Ga as a function of activity in the field of view. Conclusion 44gSc demonstrates intermediate behavior relative to 18F and 68Ga with regard to RC and contrast measurements. It is a promising radionuclide for preclinical imaging.

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

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

Evaluation of 3D reconstruction algorithms for a small animal PET camera

1997 ◽  
Vol 44 (3) ◽  
pp. 1303-1308 ◽  
Author(s):  
C.A. Johnson ◽  
J. Seidel ◽  
R.E. Carson ◽  
W.R. Gandler ◽  
A. Sofer ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Small Animal ◽  
Small Animal Pet ◽  
Reconstruction Algorithms ◽  
Animal Pet

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.

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