Which parameter most directly affects the quantity of xrays produced?

Which parameter most directly affects the quantity of xrays produced?

• A. mA
• B. kVp
• C. s
• D. Focal length

Answer: (A)

The number of X-ray photons produced in the tube is driven by the tube current. This is controlled by milliamperes (mA). Increasing mA raises the electron stream from the cathode to the anode, so more interactions occur in the target each second and more photons are generated. Over a set exposure time, the total photon output is essentially proportional to mA × s (mAs). While kVp changes the energy (quality) of the photons and distance can affect how many of those photons reach the image receptor, the direct factor that increases the actual quantity of X-rays produced is the tube current controlled by mA.

The number of X-ray photons produced in the tube is driven by the tube current. This is controlled by milliamperes (mA). Increasing mA raises the electron stream from the cathode to the anode, so more interactions occur in the target each second and more photons are generated. Over a set exposure time, the total photon output is essentially proportional to mA × s (mAs). While kVp changes the energy (quality) of the photons and distance can affect how many of those photons reach the image receptor, the direct factor that increases the actual quantity of X-rays produced is the tube current controlled by mA.