What is a typical range of kilovolts for diagnostic radiography?

• A. 60-140 kV
• B. 30-110 kV
• C. 50-120 kV
• D. 20-80 kV

Answer: (C)

Kilovoltage sets the energy of the x-ray photons, which determines how well they penetrate the body and how much contrast you’ll see in the image. Lower kV gives higher image contrast but less penetration; higher kV improves penetration but reduces contrast. For diagnostic radiography, you need a range that covers both thin and thick body parts, balancing penetration with sufficient contrast while keeping patient dose reasonable. The typical, practical range across many exams is about 50 to 120 kV, which accommodates most chest, abdomen, and extremity studies. The lower end is used when you want higher contrast for thin or small parts, and the higher end is used for thicker anatomy to ensure adequate penetration. Among the options, 50-120 kV best fits this everyday practice.