Which factor would produce a radiographic image with the highest spatial resolution?

• A. increased matrix size
• B. increased bit depth
• C. increased pixel size
• D. increased contrast resolution

Answer: (A)

Spatial resolution comes from how finely the image is sampled. In a digital radiograph, the image is a grid of pixels; the smaller those pixels, the more detail you can capture. If you increase the matrix size while keeping the same field of view, the individual pixels become smaller, boosting sampling frequency and making fine structures distinguishable. Increasing bit depth adds more gray levels, which improves contrast but not sharpness. Making pixels larger reduces the ability to separate small details, lowering spatial resolution. Increasing contrast resolution changes how many gray tones are available, not how finely you sample the image. So, enlarging the image matrix size provides the greatest gain in spatial resolution.