mA
Tube current in milliamperes. Controls the number of X-ray photons produced per unit time. Together with kVp (peak voltage) and exposure time (combined as mA·s), determines the X-ray exposure delivered to the patient.
Why it matters to buyers: mA × exposure time = mA·s, the core dose driver in radiography and CT. Dose-reduction features (CT-AEC: Smart mA, CARE Dose4D, DoseRight) modulate mA dynamically per slice based on patient attenuation. Iterative reconstruction enables lower-mA acquisitions at matched image quality.
Why it matters to engineers: mA is constrained by anode heat capacity and generator output. Sustained high-mA fluoroscopy is the #1 tube-life accelerator — long-fluoro cases on a marginal tube trigger thermal limits before they trigger arcing.