What type of screens contain layers of phosphor material that fluoresce upon exposure?

The correct answer is intensifying screens, as these specific screens are designed to enhance the effectiveness of radiographic film by utilizing phosphor materials. When x-rays hit these screens, the phosphors fluoresce and emit visible light, which in turn exposes the photographic film more efficiently than x-rays alone would. This not only allows for a reduction in the amount of radiation needed to obtain a diagnostic image, thereby enhancing safety for both patients and practitioners, but it also improves image quality in terms of contrast and detail.

Conventional screens, while they may also refer to some traditional types of radiographic screens, do not specifically describe the function of fluorescence from phosphor layers. Digital screens are part of digital imaging systems that do not rely on the fluorescent properties of phosphors but instead use electronic sensors to capture images. Lead screens are primarily used for radiation shielding to protect from scatter radiation rather than for image production. Therefore, intensifying screens' unique capability to fluoresce upon exposure makes them the appropriate choice.