The 15% rule changes which aspect of radiography?

The 15% rule in radiography is a guideline used to maintain optimal radiographic image quality while balancing the factors that affect exposure. Specifically, it states that if the kVp (kilovoltage peak) is increased by 15%, the exposure should be reduced by half to maintain the same image density, and conversely, if the kVp is decreased by 15%, the exposure time must be doubled to achieve the same density.

This rule primarily affects the exposure time because altering the kVp significantly impacts the amount of radiation reaching the image receptor. By adjusting the kVp, radiographers can control the quality of the X-rays produced and the overall exposure required. Therefore, while it is true that changing kVp can also impact the overall radiation dose to the patient and image contrast, the core focus of the 15% rule lies in managing the exposure time to reach the desired image density and quality.

Understanding the 15% rule is essential for radiologic technologists to ensure they produce high-quality images while minimizing unnecessary radiation exposure to patients.