# Whole-body dynamic FDG-PET/CT parametric imaging in alveolar echinococcosis

## TL;DR

This study explores how dynamic FDG-PET/CT imaging can better detect and quantify liver lesions in alveolar echinococcosis compared to standard PET/CT.

## Contribution

The study introduces whole-body dynamic FDG-PET/CT as a novel imaging method for improved quantification and contrast in alveolar echinococcosis.

## Key findings

- AE lesions showed significantly higher Patlak ratio compared to non-infected liver tissue.
- SUVratio and Patlak ratio both correlated strongly with E. granulosus hydatid fluid antibodies.
- Dynamic PET/CT provides higher lesion-to-background contrast than standard PET/CT.

## Abstract

To determine the role of whole-body dynamic (WBD)/Patlak parametric 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with alveolar echinococcosis (AE). This technique allows separating metabolized from unmetabolized FDG in the blood pool and tissue, potentially providing complementary qualitative information and superior quantification to standard static PET/CT images.

We prospectively analyzed 20 PET/CT datasets performed for staging or therapy monitoring in patients with confirmed AE. Dynamic and standard static PET/CT datasets were acquired in all patients, and quantitative imaging parameters were measured in the lesion with the highest uptake (i.e., maximum standardized uptake value (SUVmax) and Patlak parameters) and compared to normal liver tissue (SUVratio and Patlak ratio).

Mean SUVmax in AE manifestations was 5.7 ± 3.1 (3.2–13.9), compared to 3.2 ± 0.4 (2.5–4.2) in non-infected liver tissue, respective values for Patlak were 13.0 ± 8.6 (2.7–35.5) and 4.9 ± 2.8 (0.6–12.1). SUVratio (1.8 ± 1.1; 1.0–5.2) was significantly lower (P < 0.001) than Patlak ratio (3.2 ± 3.2; 1.1–15.6). Both ratios correlated significantly with E. granulosus hydatid fluid (EgHF) antibodies (SUVratio r = 0.73, P < 0.001; Patlak ratio r = 0.85, P < 0.001).

WBD PET/CT yields higher lesion-to-background contrast and may, therefore, have the potential to increase sensitivity in the assessment of hepatic AE.