Which term describes the ability to distinguish two adjacent lines as separate?

• A. spatial resolution
• B. modulation transfer function
• C. dynamic range
• D. contrast resolution

Answer: (A)

Spatial resolution is about how fine a detail an imaging system can separate. When two lines sit next to each other, good spatial resolution lets you see them as two distinct lines rather than a single blurred feature. This is typically described by the smallest line spacing (or line pairs per millimeter) that can be resolved. Many factors influence it, including detector pixel size, focal spot size, sampling rate, and optics. While the modulation transfer function relates to how contrast is preserved across different spatial frequencies and is connected to resolution, the direct descriptor for separating adjacent lines is spatial resolution. Contrast resolution and dynamic range, by contrast, deal with distinguishing different brightness or gray levels, not the ability to resolve fine structural detail.