Which of the following factors influences the grayscale of a digital radiograph?

Bit depth is a critical factor that influences the grayscale of a digital radiograph because it determines the number of shades of gray that can be represented in the image. A higher bit depth allows for a greater number of possible gray levels, resulting in more subtle distinctions between different tones in the image. This leads to improved contrast and detail, essential for accurately interpreting radiographic information. For example, an 8-bit image can represent 256 shades of gray, while a 16-bit image can represent over 65,000 shades. This increased range enhances the visibility of structures and nuances in the radiographic image.

Other factors, while relevant to certain aspects of image quality, do not directly influence the grayscale. Matrix size pertains to the number of pixels in the image, which affects resolution but not the range of grayscale levels. Pixel pitch, the distance between pixels, can influence image sharpness but does not affect the number of gray levels represented. Exposure time influences the overall density and quality of the image but does not inherently change the grayscale capability defined by bit depth.