Early Diagnosis of Murine Sepsis-Associated Encephalopathy Using Dynamic PET/CT Imaging and Multiparametric MRI

Tianxing Zhu; Jiayi Jiang; Yitai Xiao; Duo Xu; Zibin Liang; Lei Bi; Min Yang; Mingzhu Liang; Dan Li; Yong Lin

doi:10.1007/s11307-022-01743-z

Early Diagnosis of Murine Sepsis-Associated Encephalopathy Using Dynamic PET/CT Imaging and Multiparametric MRI

Mol Imaging Biol. 2022 Dec;24(6):928-939. doi: 10.1007/s11307-022-01743-z. Epub 2022 May 25.

Authors

Tianxing Zhu^#¹, Jiayi Jiang^#¹, Yitai Xiao^#¹, Duo Xu¹, Zibin Liang², Lei Bi¹, Min Yang¹, Mingzhu Liang³, Dan Li⁴, Yong Lin⁵

Affiliations

¹ Guangdong Provincial Key Laboratory of Biomedical Imaging and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China.
² Department of Thoracic Oncology, The Cancer Center of The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, 519020, China.
³ Department of Radiology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China. liangmzh5@mail.sysu.edu.cn.
⁴ Guangdong Provincial Key Laboratory of Biomedical Imaging and Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China. lidan25@mail.sysu.edu.cn.
⁵ Department of Psychiatry, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, 519000, Guangdong Province, China. liny337@mail.sysu.edu.cn.

^# Contributed equally.

PMID: 35612771
DOI: 10.1007/s11307-022-01743-z

Abstract

Purpose: Early diagnosis of sepsis-associated encephalopathy (SAE) is essential for the treatment and prognosis of septic patients. Static PET and MRI have shown promise for early diagnosis, while pharmacokinetic parameters from dynamic PET may provide better quantification for SAE. This study aims to compare the performance of dynamic 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]F-FDG) PET and multiparametric MRI in early imaging SAE with a view to providing guidance for the early diagnosis of SAE.

Procedures: Dynamic [¹⁸F]F-FDG-PET/CT scans and multiparametric MRI were performed in SAE mice induced by LPS. Standardized uptake value (SUV) was measured in static scan images and [¹⁸F]F-FDG pharmacokinetic parameters were analyzed with two-tissue compartment model and Patlak plot. MRI relative signal intensity (rT1) derived from T1-weighted images (pre and post contrast) and 4 parameters originating from diffusion-weighted data were measured.

Results: Both SUV and dephosphorylation rate constant (k₄) increased in SAE model as early as 6 h post sepsis induction, while k₄ increased with the relative value (SAE/normal) significantly stronger than that of SUV. Moreover, the net influx constant (K_i) showed significant decrease in SAE as early as 6 h compared with normal mice. Increased signal intensity was identified in T1-weighted contrast enhanced images and rT1 value increased at 12 h post induction. Diffusion tensor imaging (DTI) revealed fractional anisotropy (FA) decreased at 12 h and 24 h in external capsule (ec) and declined axial diffusivity (AD) was shown in white matter at 24 h.

Conclusions: The dynamic PET (k₄) was more sensitive than static PET (SUV) for early diagnosis of SAE and declined K_i was firstly found in murine SAE, which indicated the advantage of dynamic PET/CT in early detection and differential diagnosis of SAE. While MRI has a higher soft tissue resolution than PET/CT and can classify more subtle brain areas, the comprehensive utilization of the two modalities is helpful for managing SAE.

Keywords: Dynamic PET/CT; Multiparametric magnetic resonance imaging; Sepsis; Sepsis-associated encephalopathy; [18F]F-FDG.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Diffusion Tensor Imaging
Early Diagnosis
Fluorodeoxyglucose F18
Mice
Multiparametric Magnetic Resonance Imaging*
Positron Emission Tomography Computed Tomography / methods
Positron-Emission Tomography / methods
Radiopharmaceuticals
Sepsis-Associated Encephalopathy*

Substances

Fluorodeoxyglucose F18
4-O-carboxymethylascochlorin
Radiopharmaceuticals