Image quality evaluation of a small animal PET scanner

In preclinical PET, SUV (standardized uptake value) is a robust quantifier that can be used to analyze PET images. Several factors – biological or technical – can affect SUV determination. Among technical factors, it is possible to cite the reconstruction protocols of PET images. This work evaluated the influence of two resolution modes – standard and high – on mean and maximum SUVs. The PET image of a mouse with a tumor in left flank was chosen from a PET image bank and reconstructed using two different protocols varying the resolution mode. The post-processing of images was performed using AMIDE software and eight volumes of interest (VOIs) were defined. Qualitatively, there was light improvement in structures definition in high-resolution image compared to standard resolution image. At the semiquantitative analysis, image reconstruction protocols using high-resolution mode did not significantly improve the recuperation of radiopharmaceutical uptake into analyzed tissues.

Section: Introductionmentioning

confidence: 99%

Influence of the resolution mode on mean and maximum SUV for PET images acquired by a LabPET SOLO 4 scanner

Barbosa,

Souza,

Gontijo

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.

Performance based on NEMA NU-4 2008 Standard of CDTN/CNEN’s Small Animal PET Scanner

Gontijo¹,

Ferreira

Silva³

et al. 2022

Self Cite

This study aimed to evaluate the general performance of the preclinical PET scanner (LabPET Solo 4, GE) at CDTN/CNEN using the NEMA NU 4-2008 protocol. The performance parameters include: (i) spatial resolution; (ii) scatter fraction and counts rate performance; (iii) sensitivity and (iv) image quality. For the evaluation specific simulators and a sealed radioactive source of Sodium-22 were used. The results revealed that the NEMA-based radial spatial resolution ranged from 1.79 mm at the center of the FOV to 2.49 mm at a radial offset of 25mm. Tangential resolution ranged from 1.95mm at the center of the FOV to 3.50mm at a radial offset of 25mm. Axial resolution ranged from 1.78mm at the center of the FOV to 5.42mm at a radial offset of 25mm. Iterative image reconstruction improved the radial spatial resolution to 0.93mm at the center of the FOV. For the mouse-sized phantom, the peak noise equivalent count rate (NECR) was 37.8kcps at 85MBq whereas the peak true count rate was 169.9kcps at 125MBq with a count loss of 7.8% for the maximum rate reached at 103.3MBq. The peak of sensitivity (S) and absolute sensitivity (SA) at the center of axial field-of-view (FOV) is 5.7cps.Bq-1 and 0.63%, respectively. The overall imaging capabilities of the scanner were assessed using the NEMA image-quality phantom. The image roughness was 9.5%. Spillover rates (SORs) in air and in water were 0.26 and 0.17 respectively. The recovery coefficients (RCs) were 0.12 for the 1-mm-diameter rod and 0.91 for the 5-mm-diameter rod. The results demonstrate that CDTN/CNENsmall animal PET scanner has adequate reliability and acquired images are compatible with international quality standards for the molecular imaging research.