Validation of Image Qualities of a Novel Four-Mice Bed PET System as an Oncological and Neurological Analysis Tool.

Kyung Jun Kang,Se Jong Oh,Kyo Chul Lee,Jae Yong Choi,Kyung Rok Nam,Ji-Ae Park,Heesu Ahn

doi:10.3390/jimaging7030043

Kyung Jun Kang, Se Jong Oh + Show 5 more

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https://doi.org/10.3390/jimaging7030043

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Abstract

Background: Micro-positron emission tomography (micro-PET), a small-animal dedicated PET system, is used in biomedical studies and has the quantitative imaging capabilities of radiotracers. A single-bed system, commonly used in micro-PET, is laborious to use in large-scale studies. Here, we evaluated the image qualities of a multi-bed system. Methods: Phantom imaging studies were performed to assess the recovery coefficients (RCs), uniformity, and spill-over ratios (SORs) in water- and air-filled chambers. 18F-FDG and 18F-FPEB PET images of xenograft and normal mice from the multi-bed and single-bed systems were compared. Results: For small diameters (< 3 mm), the RC values between the two systems differed significantly. However, for large diameters (> 4 mm), there were no differences in RC values between the two systems. Uniformity and SORs of both systems were within the tolerance limit of 15%. In the oncological study, the estimation of 18F-FDG uptake in the tumor was significantly lower in the multi-bed system than that in the single-bed system. However, 18F-FDG PET in xenograft mice with tumor size > 4 mm revealed the variation between subjects within the multi-bed system group to be less than 12%. In the neurological study, SUV for the multi-bed group was 25–26% lower than that for the single-bed group; however, inter-object variations within the multi-bed system were below 7%. Conclusions: Although the multi-bed system showed lower estimation of radiotracer uptake than that of the single-bed system, the inter-subject variations were within acceptable limits. Our results indicate that the multi-bed system can be used in oncological and neurological studies.

Highlights

Molecular imaging is used for the diagnosis of oncological, neurological, and cardiovascular diseases [1,2,3,4]
For rods above 4 mm, there was no significant difference in the recovery coefficients (RCs) values between the two systems
Using multiple beds for sizes above 4 mm is recommended because the RC difference is under 2%

Summary

Introduction

Molecular imaging is used for the diagnosis of oncological, neurological, and cardiovascular diseases [1,2,3,4]. The demand for preclinical research is increasing worldwide, as it can predict clinical trials and advance our understanding of the pathophysiological mechanisms underlying a specific disease [8] For this purpose, researchers use micro-PET (μPET), which is a small-animal dedicated system. Few studies have focused on the validity of oncological and neurological PET imaging of the four-mice bed system. 18F-FDG and 18F-FPEB PET images of xenograft and normal mice from the multi-bed and single-bed systems were compared. The estimation of 18F-FDG uptake in the tumor was significantly lower in the multi-bed system than that in the single-bed system. Conclusions: the multi-bed system showed lower estimation of radiotracer uptake than that of the single-bed system, the inter-subject variations were within acceptable limits. Our results indicate that the multi-bed system can be used in oncological and neurological studies

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