Discussion
This radiograph demonstrates unilateral pulmonary edema in the right lung. The differential for this appearance is limited and includes severe mitral regurgitation (such as a papillary muscle rupture), unilateral pulmonary venous obstruction, and lymphangitic spread of malignancy mimicking edema. Those etiologies rarely present with as much uniformity as this case, which was due to prolonged decubitus positioning that rapidly resolved on subsequent radiographs.
Incidentally noted is the presence of a tracheostomy tube with an overlying tracheostomy mask supplying oxygen to the patient.