Which factor does not primarily contribute to spatial resolution in digital imaging?

• A. Pixel size
• B. Matrix size
• C. Bit depth
• D. Field of view

Answer: (C)

Spatial resolution measures how finely an imaging system can distinguish closely spaced structures. It mainly depends on how the image is sampled in space: pixel size sets the smallest detail that can be captured, with smaller pixels providing finer sampling; matrix size increases the number of samples across the image, so a larger matrix improves spatial sampling when the field of view is kept constant; field of view determines how much area each pixel represents, so a larger FOV enlarges pixel size and reduces sampling density (lower spatial resolution) while a smaller FOV tightens sampling and improves resolution. Bit depth, on the other hand, affects how many gray levels per pixel can be stored, influencing contrast resolution rather than the spacing of samples. So it does not primarily contribute to spatial resolution.