Role of ultrasound in qualitative and quantitative assessment of pleural effusion - a diagnostic analytic study

This study aims to evaluate the diagnostic utility of ultrasonography in differentiating exudative from transudative pleural effusion and estimating its volume. The study will enrol a total of 100 subjects over 15-18 months period attending Departments of Medicine/ICU/Radio-Diagnosis in a Corporate hospital, and having pleural effusion diagnosed on USG. To differentiate transudative and  exudative pleural effusion, lung USG will evaluate accuracy of presence of a combination of factors including echogenicity, septations and pleural thickening, as compared to pleural fluid analysed using Light’s criteria. Estimation of volume of pleural effusion on lung USG will use the Balik’s Formula (supine position)/Goecke Formula (erect position) as compared to CT chest volumetry. The diagnostic accuracy of various ultrasonographical features being used to distinguish between exudative and transudative pleural effusion will be calculated. Diagnosis of exudate/ transudate and volumetry on USG will help clinician assess the effusion as a whole without the need for invasive investigations like thoracocentesis. Faster diagnosis provided by USG will help make prompt therapeutic decisions and early institution of treatment. Further, in effusions whose nature is clear on ultrasonography and which do not cause distress to the patient, thoracocentesis can be avoided. However, in patients with respiratory distress and large volumes of effusion, therapeutic thoracocentesis would still be required.