Which change in technical factors will result in the greatest reduction in radiation dose to the patient?

Changing the field size from 14"x17" to 8"x10" results in the greatest reduction in radiation dose to the patient primarily because it limits the area being irradiated. A smaller field size decreases the volume of tissue exposed to the X-ray beam, which directly reduces the amount of radiation that interacts with the patient's body. This not only minimizes the patient's overall dose but also decreases the scatter radiation that could potentially affect image quality or other areas of the patient's body.

By using a smaller field size, you focus the radiation on the specific area of interest, which enhances the image quality through improved contrast and reduces unnecessary exposure to surrounding tissues. This principle aligns with the ALARA (As Low As Reasonably Achievable) concept in radiation safety, emphasizing the importance of minimizing radiation exposure while achieving adequate diagnostic quality.