What is the diagnosis associated with blunting of costophrenic angles on an XR?

Blunting of the costophrenic angles on an X-ray is most commonly associated with pleural effusion. When a pleural effusion occurs, fluid accumulates in the pleural space, particularly in the areas of the costophrenic angles, which are the angles formed by the diaphragm and the thoracic wall. This accumulation of fluid leads to an obscuring of the sharp angles that are normally visible on an X-ray, resulting in a blunted appearance.

In contrast, other conditions like pneumothorax typically present as a visceral pleural line with a visible pleural space that can appear as increased lucency in the affected lung area rather than blunted angles. Pulmonary edema manifests as increased vascular markings and may show bat-wing opacities but does not specifically cause blunting of the costophrenic angles. Congestive heart failure, while it can lead to pulmonary edema, also would not directly cause the blunting of costophrenic angles without the presence of effusion. Thus, the radiographic finding of blunted costophrenic angles is a key indicator of pleural effusion.