Sonographic Evaluation of Pleural Effusion

Abstract

Background: Although at times small amounts of pleural fluid is detected on the lateral decubitus chest radiograph, this may be impossible to obtain in severely ill patients. Because of its ready availability and ability for bedside imaging, ultrasonography has become a crucial imaging modality not only in detecting the presence of pleural fluid but also as a guide to aspiration. Aims: To sonographically determine the nature of pleural effusions. To analyze predictability of both benign and malignant pleural effusions and to study statistical value of various ultrasound characteristics in differentiating exudative and transudative as well as benign and malignant effusions in correlation with thoracocentesis. Material and Methods: Sonographic feature as well as fluid cytology was evaluated. Following categorization into exudates or transudate as well as benign or malignant the diagnosis was then correlated biochemically. Results: Transudates were anechoic, while an anechoic effusion may be either a transudate or an exudate. Complex septation, internal echoes, thickened pleura or homogeneously echogenic patterns were always exudates. Sonographic findings of pleural nodules and associated parenchymal lesions in the lung and liver were indicative of malignancy. Conclusions: Ultrasound in addition to being highly sensitive for pleural effusion also aided in characterizing the nature and minimizing the complications during thoracocentesis. Pleural effusions were categorized into exudates and transudate as well as benign and malignant with a certain degree of confidence based on sonographic findings.