According to the inverse square law, what happens to the patient dose when the source-to-image distance (SID) decreases?

According to the inverse square law, the intensity of radiation is inversely proportional to the square of the distance from the radiation source. This means that as the source-to-image distance (SID) decreases, the radiation intensity increases significantly because the radiation diverges over a larger area as the distance increases.

In practical terms, when the SID is reduced, the same amount of radiation is concentrated over a smaller area, resulting in a higher dose per unit area at the patient’s location. Consequently, the patient's dose increases as the SID decreases. This principle is crucial in radiography, as it underscores the importance of maintaining optimal distances to ensure patient safety while acquiring quality images. Hence, the correct answer highlights the relationship between distance and patient dose as dictated by the inverse square law.