How does milliamperage (mA) relate to patient dose?

Milliamperage (mA) is a measure of the x-ray tube current, which indicates the number of electrons flowing through the tube and ultimately affects the quantity of x-rays produced during an exposure. When the milliamperage is increased, more electrons are emitted, resulting in the production of a greater number of x-ray photons. This increase in the number of x-ray photons directly raises the amount of radiation exposure that the patient receives.

Thus, patient dose is directly proportional to the milliamperage. A higher milliamperage leads to a higher dose because the increased number of x-ray photons enhances the amount of radiation energy absorbed by body tissues. Conversely, reducing the milliamperage will decrease the patient dose because fewer x-ray photons will be generated, resulting in lower radiation exposure.

This relationship is fundamental in radiography as it allows radiologic technologists and radiologists to adjust exposure settings to obtain optimal image quality while minimizing patient radiation dose.