B. Pleural Effusion
C. Lung Collapse
Image shows:Erect chest radiograph showing large right pleural effusion opacifying the right mid and lower zone.
- The complete opacification of the right mid and lower zones is due to fluid in the pleural cavity.
- Note the meniscus sign,i.e. concavity of the fluid level due to surface tension with the pleura.
- Blunting of costophrenic angle may be due to a small pleural effusion or focal pleural thickening.
- If the patient cannot stand, a lateral decubitus CXR is sometimes performed to help in the diagnosis of pleural effusion (as the fluid layers out in the dependent position).
- Ultrasound or CT thorax serve as alternative modalities for early detection of small pleural effusion.
- Ultrasound has the advantage of not involving radiation, and can be used to guide drainage.
- CT has the advantage of evaluating the underlying lung and mediastinal structures to identify the cause of the effusion.