What happens to the ESE when the OID is increased in fluoroscopic imaging?

In fluoroscopic imaging, when the Object-to-Image Distance (OID) is increased, the Entrance Skin Exposure (ESE) typically increases. This phenomenon occurs because as the OID increases, there is a greater distance between the x-ray source and the patient. Consequently, a larger portion of the x-ray beam may be required to cover the area of interest adequately, resulting in an increase in exposure levels to achieve the necessary image quality.

This increased distance can lead to the x-rays diverging more before they reach the patient, effectively increasing the amount of radiation that the patient absorbs at the skin level. This relationship underscores the importance of optimizing OID in fluoroscopic techniques to ensure that radiation exposure is minimized while still acquiring high-quality images for diagnostic purposes.