Quality control of small animal PET scanner: The Brazilian Scenario

This study evaluated Image Quality (IQ) parameters and spatial resolution (SR) of Triumph® LabPET systems installed in three different Brazilian preclinical molecular imaging centers. A comprehensive evaluation of the PET scanner intrinsic parameters is important to optimize the acquired images, providing more reliable qualitative and quantitative analyses. Experiments were carried out at the centers: C1 - Molecular Imaging Laboratory of the CDTN/CNEN; C2 - Laboratory of Nuclear Medicine of HCFMUSP; C3 - Preclinical Research Center of the Brain Institute at PUC-RS. IQ phantom PET images were acquired as recommended in NEMA NU 4-2008 standard. Image reconstructions were performed in each system using the same reconstruction protocol. Data was processed using PMOD® software. The IQ parameters: (i) uniformity, (ii) spill-over ratio (SOR) and (iii) recovery coefficients (RC) were evaluated and compared. For Uniformity test, the percentage standard deviations of mean activity concentration were 7.8%; 7.3% and 6.4% for Centers 1, 2 and 3 respectively. Cold chambers RSO values in the systems 1, 2 and 3 were respectively 0.16, 0.19 and 0.21 for water; 0.26; 0.28 and 0.30 for air. The RC’s for rod diameters from 1 to 5 mm ranged from 0.08 to 0.91 for the three centers. Results revealed that the three PET systems have appropriate quality parameters for pre-clinical studies, presenting values compatible with international standards. This study was able to reveals the performance of preclinical PET system of different Brazilian imaging centers and may support the standardization of a National Quality Control Program for Small Animal PET scanners.

Section: Recovery Coefficientsupporting

confidence: 90%

Section: Spatial Resolution Evaluationmentioning

confidence: 99%

Section: Image Quality Evaluationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Comparative analysis of image quality parameters and spatial resolution of three Small Animal PET scanner in Brazil

Gontijo,

Ferreira,

Faria

et al. 2023

The Historical Background of Quality Assurance at Laboratório de Imagem Molecular of the Centro de Desenvolvimento da Tecnologia Nuclear

Vilaça Silva,

Modesto Gadelha Gontijo,

Vidal Ferreira

2024

The Centro de Desenvolvimento da Tecnologia Nuclear has a small animals positron emission tomograph in its Laboratório de Imagem Molecular. This equipment, the GE HealthCare LabPET SOLO 4 model, is widely used in preclinical studies related to the development of new radiopharmaceuticals or novel applications of conventional radiopharmaceuticals. The “PET Image Quality” subproject, integrated into the Centro de Desenvolvimento da Tecnologia Nuclear multi-year planning for 2018-2022, proposed actions involving quality assurance and human resources development for the laboratory. This work aims to consolidate the historical trajectory of Quality Assurance at Laboratório de Imagem Molecular of the Centro de Desenvolvimento da Tecnologia Nuclear. A search for documents related to the laboratory was conducted in the institutional quality system, called d-Qualidade, while a search for the curricula vitae of laboratory researchers was performed on the Plataforma Lattes, with the purpose of identifying the main products generated related to the Quality theme in the laboratory. The scientific production of the laboratory team demonstrates its pioneering role in Brazil in developing studies about the Quality Management applied to the small animals positron emission tomogragh. The laboratory history in the field of Quality Management emphasizes its national prominence and reveals the group's commitment over the past decade to significant technical/scientific production.

Image quality evaluation for two different positron emitters in a preclinical PET scanner

Gadelha¹,

Ferreira²,

Souza³

et al. 2020

Positron emission tomography (PET) is widely used in preclinical trials, generating molecular images applied to biochemical, metabolic and functional investigation of organs and tissues. The positron emitters 11C and 18F radionuclides are relevant for different diseases studies. However, they have different positron energies, ranges, and branching ratio. This could result in a distinct quality between the acquired PET images. Thus, the aim of this study is to evaluate the image quality performance of the PET scanner (LabPET 4, GE) at CDTN/CNEN using the NEMA NU 4-2008 standards and specific phantom for these two different positron emitters. The NEMA image-quality (IQ) phantom consists of 3 different regions to analyze distinct characteristics: uniformity, recovery coefficients (RCs) and spill-over rations (SOR) in air and water. The IQ phantom was filled with two different aqueous solutions (18F-FDG and 11C-PK11195), both activities calibrated at the beginning of acquisition (3.7MBq). The IQ phantom was placed in the center of the field-of-view (FOV) and measured with the typical whole body imaging protocol. The images were reconstructed following the Molecular Imaging Laboratory (LIM/CDTN) standard protocol: MLEM-3D algorithm, 20 iterations, no high-resolution mode, no attenuation or scatter corrections, no post-filtering. PMOD® software was used to perform images post-processing following NEMA analyses standard. The %SD of medium concentration activity for 18F and 11C was 7.7 and 14.5, respectively. The RCs for 18F and 11C were 0.11 and 0.12 respectively for the 1-mm-diameter rod and 0.88 and 0.77 for the 5-mm-diameter rod. SORs in air were 0.19 and 0.22, respectively, and in water 0.29 and 0.33. Experimental results demonstrates that when 18F radionuclide is used, PET images presents a better performance in the image quality tests compared to 11C PET images.