In this patient, a large pleural effusion obscures most of the right lung field. In an uncomplicated effusion such as this, fluid is higher laterally than medially, forming a meniscus with the pleura. A horizontal fluid level is seen only in hydropneumothorax (both fluid and air within pleural cavity). Blunting of costophrenic angles is first noted on the PA view with approximately 200 cc of fluid accumulation.