68Ga-NOTA PET imaging for gastric emptying assessment in mice

Xinyu Wang,Maoyu Cao,Juan Liu,Yan Wang,Donghui Pan,Lizhen Wang,Min Yang,Xueyan Chen,Yuping Xu,Junjie Yan,Yu Liu

doi:10.1186/s12876-021-01642-7

Abstract

BackgroundPositron emission tomography (PET) has the potential for visualization and quantification of gastric emptying (GE). The traditional Chinese medicine (TCM) has been recognized promising for constipation. This study aimed to establish a PET imaging method for noninvasive GE measurement and to evaluate the efficacy of a TCM on delayed GE caused by constipation using PET imaging.Methods[68Ga]Ga-NOTA was synthesized as the tracer and sesame paste with different viscosity were selected as test meals. The dynamic PET scans were performed after [68Ga]Ga-NOTA mixed with test meals were administered to normal mice. Two methods were utilized for the quantification of PET imaging. A constipation mouse model was treated with maren chengqi decoction (MCD), and the established PET imaging scans were performed after the treatment.Results[68Ga]Ga-NOTA was synthesized within 20 min, and its radiochemical purity was > 95%. PET images showed the dynamic process of GE. %ID/g, volume, and total activity correlated well with each other. Among which, the half of GE time derived from %ID/g for 4 test meals were 3.92 ± 0.87 min, 13.1 ± 1.25 min, 17.8 ± 1.31 min, and 59.7 ± 3.11 min, respectively. Constipation mice treated with MCD showed improved body weight and fecal conditions as well as ameliorated GE measured by [68Ga]Ga-NOTA PET.ConclusionsA PET imaging method for noninvasive GE measurement was established with stable radiotracer, high image quality, and reliable quantification methods. The efficacy of MCD on delayed GE was demonstrated using PET.

Highlights

Positron emission tomography (PET) has the potential for visualization and quantification of gastric emptying (GE)
Radiochemistry and in vitro stability The synthesis of [68Ga]Ga-NOTA was completed within 20 min with a radiochemical purity > 95% (Fig. 1a)
The 4 groups of mice reached the maximum radioactivity in the stomach at similar time points by gavage, the PET images showed that the time points at which different contents were discharged from

Summary

Introduction

Positron emission tomography (PET) has the potential for visualization and quantification of gastric emptying (GE). This study aimed to establish a PET imaging method for noninvasive GE measurement and to evaluate the efficacy of a TCM on delayed GE caused by constipation using PET imaging. Gastrointestinal motility disorders such as gastroparesis, functional dyspepsia, and constipation, affect the life quality of a huge population worldwide and cause considerable medical expenses and economic burden [1, 2]. Gastric emptying (GE) is one of the most important parts of gastrointestinal motility. The indirect methods such as 13C breathe test

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