An increase in which of the following technical factors would decrease patient exposure?

Increasing filtration in a radiographic setup effectively reduces patient exposure by selectively allowing only the penetrating x-rays to pass through while absorbing lower-energy, non-penetrating x-rays. These lower-energy x-rays contribute to unnecessary radiation dose without providing diagnostic value.

Filtration acts as a barrier that filters out these softer x-rays, which are more likely to be absorbed by the patient’s body instead of contributing to the image formation. By removing these less useful rays, the overall dose of radiation a patient receives is decreased while maintaining image quality.

On the other hand, increasing kilovoltage peak (kVp) would enhance the quality of the x-ray beam, potentially allowing for lower mAs, but it does not inherently decrease exposure. Milliampere-seconds (mAs) directly influences the quantity of x-rays produced; increasing it raises patient dose. Focal spot size primarily affects image sharpness and resolution but has no direct relationship with exposure reduction. Thus, filtration is the most effective factor in minimizing patient exposure while still achieving a quality diagnostic image.