# Differentiation Between Abscesses and Unnecessary Intervention Fluid After Pancreas Surgery Using Dual-Energy Computed Tomography

## TL;DR

This study shows that dual-energy CT can help distinguish abscesses from other post-surgery fluids in the pancreas area.

## Contribution

The study introduces the use of virtual non-contrast images from dual-energy CT to differentiate abscesses from postoperative fluids.

## Key findings

- Virtual non-contrast (VNC) images showed significant differences between abscesses and ascites.
- Abscesses were more likely to require intervention compared to postoperative ascites.
- C-reactive protein levels and fever incidence differed significantly between abscess and ascites groups.

## Abstract

Introduction: This study aimed to evaluate the potential of dual-energy computed tomography (CT) to distinguish postoperative ascites, pancreatic fistula, and abscesses.

Materials and method: Patients who underwent biliary and pancreatic surgery performed at our institution between June 2021 and February 2022 were included in the study. Postoperative body fluid samples were collected through a drain or percutaneous drainage. These samples were set in a phantom, and imaging data were obtained using dual-energy CT. Image analysis was performed to obtain CT values at each energy in virtual monoenergetic images (VMIs), effective atomic number, iodine map, and virtual non-contrast (VNC) images. VMIs were calculated from 80 and 140 kVp tube data at 10 kV each from 40-140 kV. Additionally, the effective atomic number, iodine map, and VNC images were reconstructed from the material decomposition process using water and iodine as the base material pair.

Results: In this study, 25 patients (eight with abscess and 17 with ascites) were included. No significant association was observed between the presence or absence of abscess and malignancy or surgical procedure. The intervention was performed in six of the eight patients with abscesses. In contrast, five of the 17 patients with postoperative ascites required intervention. A significant relationship was observed between the intervention and the presence of an abscess. Significant differences in C-reactive protein values and the incidence of fever were observed between the groups. Only VNC showed a significant difference between the groups.

Conclusions: VNC using dual-energy CT could differentiate abscesses from postoperative fluid.