Why do magnification modes result in increased radiation dose?

Magnification modes result in increased radiation dose primarily because they decrease the field size, which concentrates the x-ray beam onto a smaller area of the patient. When the field size is reduced, the same amount of radiation is focused on a smaller target, leading to an increase in the intensity of radiation delivered to that specific area. This concentration of radiation can produce more photoelectric interactions, which, in turn, results in a higher dose to the tissues within that reduced field.

While the truest implication of increased radiation dose in magnification modes involves the geometric changes that occur, resulting in a higher dose distribution, other aspects of fluoroscopy practices may inadvertently contribute to increased exposure. However, the primary dynamics of dose escalation relate to the reduced field size that magnification imposes.