If all other factors remain constant, what happens to the entrance skin exposure (ESE) rate as SSD increases?

As the source-to-skin distance (SSD) increases, the entrance skin exposure (ESE) rate decreases due to the inverse square law. This law states that the intensity of radiation exposure is inversely proportional to the square of the distance from the source of radiation.

In practical terms, when the distance between the radiation source and the patient's skin increases, the same amount of radiation is spread over a larger area, resulting in less intensity or dose delivered to any specific point on the patient's skin. This reduction in intensity translates to a lower entrance skin exposure rate. Understanding this principle is critical for ensuring patient safety and minimizing radiation exposure during fluoroscopic procedures.