Which structures might appear blunted on a chest radiograph in the presence of pleural effusion?

• A. Costophrenic angles
• B. Pulmonary veins
• C. Diaphragmatic recess
• D. Cardiac silhouette

Answer: (A)

When pleural effusion is present, the excess fluid in the pleural space can lead to blunted costophrenic angles on a chest radiograph. The costophrenic angles, located where the diaphragm meets the pleural lining, are typically sharp and well-defined. However, when fluid accumulates, this area can appear rounded or blunted due to the presence of the fluid. This blunting serves as an important radiographic sign for clinicians to identify pleural effusions early.

Recognizing blunted costophrenic angles helps in the assessment and management of pleural effusions, guiding decisions on further imaging, such as ultrasound or CT, and interventions like thoracentesis. Detecting a change in the normal contour of the costophrenic angles can alert radiologists and clinicians to the existence and potentially the volume of pleural effusion, thus aiding in patient management.