When a coin is facing you on an AP/PA film, what anatomical structure does it represent?

When a coin is positioned in front of you on an anteroposterior (AP) or posteroanterior (PA) film, it typically represents the esophagus. This is due to the anatomical location and the projection of the esophagus in these imaging views. The esophagus is located in the midline, posterior to the trachea, and it can appear as a circular or oval density on these types of X-rays, similar to the shape of a coin.

In contrast, other structures like the trachea, stomach, and heart have different positioning and shapes on imaging. The trachea is more centrally located but appears more tubular and usually is surrounded by air, making it less likely to represent a coin-like density. The stomach has a more complex shape and would not typically present as a simple disk on an AP/PA film. The heart, while centrally located in the chest, has a unique silhouette that is recognized as a cardiac contour rather than a simple, round shape.