Definition: Fluid accumulates in pleural space.
You are looking at pleural effusion on right, in the Chest x-ray.
Irrespective of the nature of fluid, radiologically they will look similar.
Radiological criteria are:
Comprehend the following
What is pleural effusion?
What are the types of fluid that can accumulate in pleural space?
What are the mechanisms by which fluid accumulates in pleural space?
How does pleural effusion appear in CT?