Correlation of pleural effusions' grayscale sonographic parameters with fluid's analysis results

Area of Science:

• Medical Imaging
• Pulmonology
• Diagnostic Ultrasound

Background:

• Quantitative sonography is used for pleural fluid volume but lacks methods for density and qualitative assessment.
• A novel quantitative method using pixel density of ultrasound images is proposed to evaluate pleural effusion echogenicity.

Purpose of the Study:

• To introduce and validate a new quantitative method for assessing pleural effusion echogenicity using ultrasound pixel density.
• To establish the hypoechogenicity index (HI) as a tool for evaluating pleural effusion characteristics.

Main Methods:

• Pleural ultrasound (US) images were acquired from 62 patients with pleural effusion.
• The hypoechogenicity index (HI) was calculated by comparing the mean echo levels of pleural effusion pixels to the 10th rib pixels.
• Diagnostic thoracocentesis and biochemical marker measurements were performed for comparison.

Main Results:

• The hypoechogenicity index (HI) showed significant correlation with LDH, cell count, and pH.
• Effusion pixel mean values were also significantly correlated with the HI.
• The pixel ratio did not correlate with other ultrasonography-derived parameters or biomarkers.

Conclusions:

• The study introduces the hypoechogenicity index (HI) as a novel measure of pleural effusion inflammation density.
• HI, when used with classical biomarkers, may aid in discriminating between pleural transudate and exudate.