MRCP UK EXAMINATIONS

Detailed explanation-1: -Blunting of a costophrenic angle is the classic sign for pleural effusion. It is important to note that minor blunting may be caused by scarring or chronic atelectasis. Effusions first become apparent on lateral upright radiographs with blunting of the posterior costophrenic angle.

Detailed explanation-2: -A large free pleural effusion appears as a dependent opacity with lateral upward sloping of a meniscus-shaped contour. The diaphragmatic contour is partially or completely obliterated, depending on the amount of the fluid (silhouette sign).

Detailed explanation-3: -The most frequent but least specific criterion for detecting pleural effusions on supine radiographs is blunting of the costophrenic angle. Other helpful signs include loss of the hemidiaphragm and increased density of the hemithorax. A normal supine radiograph does not exclude a pleural effusion.

Detailed explanation-4: -Pleural fluid is usually straw-colored, and if it is milky white, then a chylothorax should be suspected. Diagnosis of hemothorax can be made if the pleural fluid hematocrit is more than 0.5 times that of serum hematocrit. The chest x-ray may reveal a mediastinal shift to the contralateral chest cavity.

Detailed explanation-5: -Blunting of the costophrenic angles is usually caused by a pleural effusion, as already discussed. Other causes of costophrenic angle blunting include lung disease in the region of the costophrenic angle, and lung hyperexpansion.