Which statement best describes differences between film-based and digital radiography in relation to radiation exposure?

• A. Digital radiography generally requires less exposure due to higher detector sensitivity and dynamic range; film-based generally requires higher exposure for adequate density; technique and processing also play a role.
• B. Digital radiography generally requires more exposure because of processing constraints and sensor limitations.
• C. Film-based radiography requires less exposure due to slower processing.
• D. Exposure levels are identical for both film-based and digital radiography.

Answer: (B)

Digital radiography generally allows lower patient exposure because digital detectors are more sensitive and have a wider dynamic range than film. That means you can obtain a diagnostically usable image at a lower entrance dose, while film requires higher exposure to reach the same density and visibility of anatomical structures.

Processing differences also matter. Film needs chemical development, which introduces variability and may require reexposure if results aren’t adequate. Digital systems rely on image processing software to adjust brightness and contrast, enabling optimization of the image without increasing dose. Of course, the exact dose depends on technique factors (kVp, mA, exposure time), patient size, and the specific equipment, but the general principle is that digital radiography can achieve the same diagnostic quality with less exposure than film.