Subpulmonic effusion

Subpulmonic effusion is excess fluid that collects at the base of the lung, in the space between the pleura and diaphragm. It is a type of pleural effusion in which the fluid collects in this particular space, but can be "layered out" with decubitus chest radiographs.

An interesting aspect of this finding is the generally minimal nature of costophrenic angle blunting usually found with larger pleural effusions.