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

The correct understanding of the inverse square law indicates that as the source-to-image distance (SID) decreases, the intensity of radiation or radiation dose received by the patient increases. The law states that the intensity of radiation from a point source is inversely proportional to the square of the distance from the source. This means that if the distance is halved, the radiation intensity (and thus the dose) will increase fourfold (since 1 divided by (1/2)^2 equals 4).

Therefore, a decrease in SID results in a higher dose of radiation delivered to the patient, which is why the correct answer reflects an increase in patient dose under those conditions. Understanding this principle is critical in radiological practices to ensure patient safety and minimize radiation exposure.