Abstract
Background: Pleural fluid (PF) echogenicity is expressed qualitatively as echogenic or anechoic. Quantification of echogenicity has been found to contribute useful diagnostic information in assessment of organs such as the thyroid and liver. This study aimed to assess the feasibility of quantifying PF echogenicity.
Methods: Using a curvilinear probe US scans of patients undergoing thoracentesis were saved as greyscale images that were transferred to a computer to analyse using the software ‘ImageJ’. The software grades greyscale images from 0 (black) to 255 (white). PF relative echogenicity (PFRE) was calculated as the ratio of the PF:liver echogenicity to control for difference in sonographic windows between patients. To ensure uniformity of US parameter per patient, analysis of liver and effusion echogenicity was done by choosing a region of interest the same image (right effusions) or in a different image with the exact US settings (left effusions).
Results: 30 cases were included. Mean (SD) PF protein was 4.7 (1) gm/dL. Median (IQR) LDH was 457 (240-1044) IU/L and median glucose was 98 (31-115) gm/dL. Mean PFRE was 0.52 (0.29). PFRE significantly correlated with LDH (r 0.67, p<0.001) but the correlation was not perfectly linear (figure).
Conclusion: PFRE measurement is feasible using simple technique and correlated with PF inflammatory status. Future studies should explore its utility for diagnostic and prognostic purposes.
Footnotes
Cite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA3544.
This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2021
