Which condition is characterized by a "water-bottle" shaped heart on imaging?

A "water-bottle" shaped heart on imaging is typically associated with pericardial effusion. This condition occurs when excess fluid accumulates in the pericardial cavity, the space surrounding the heart. The accumulated fluid can cause the heart to assume a more globular or rounded appearance on chest X-ray or other imaging modalities, resembling the shape of a water bottle.

In pericardial effusion, the volume of fluid in the pericardial space results in dilation of the heart silhouette, making it appear larger and closer to a spherical shape, rather than the normal conical shape of a healthy heart. This distinctive appearance helps clinicians in diagnosing pericardial effusion when reviewing imaging studies.

Other conditions may present with changes on imaging, but they do not typically produce the characteristic "water-bottle" appearance of the heart. For instance, aortic coarctation typically leads to changes such as upper body hypertension and may show indirect signs of heart strain, whereas cardiomyopathy often results in a more varied shape depending on the type (dilated, hypertrophic, or restrictive). Pneumothorax primarily affects lung fields and does not influence heart shape directly in imaging studies.