Which modality shows 8 lp/mm resolution?

Which modality shows 8 lp/mm resolution?

• A. Gamma camera
• B. Digital radiography
• C. MRI
• D. Screen-Film Radiography

Answer: (D)

Line pairs per millimeter measures how finely an imaging system can separate alternating black and white lines. Screen-film radiography provides very high spatial detail because the film–screen combination records a continuous analog signal with minimal digital discretization, which lets it resolve fine structures. In practice, conventional screen-film systems often reach around 8 lp/mm in high-contrast regions, meaning features on the order of about 0.125 mm can be distinguished as separate line pairs. Gamma cameras rely on collimation, which blurs fine details and reduces resolution, so they do not reach this level. MRI delivers high anatomic detail and is typically described in millimeter voxels rather than lp/mm, so its resolution isn’t characterized this way. Digital radiography improves efficiency and dynamic range but is usually limited by detector pixel size and sampling, often yielding fewer lp/mm than optimized screen-film setups. Thus, among the options, screen-film radiography best achieves about 8 lp/mm, reflecting its superior inherent spatial resolution for fine detail.

Line pairs per millimeter measures how finely an imaging system can separate alternating black and white lines. Screen-film radiography provides very high spatial detail because the film–screen combination records a continuous analog signal with minimal digital discretization, which lets it resolve fine structures. In practice, conventional screen-film systems often reach around 8 lp/mm in high-contrast regions, meaning features on the order of about 0.125 mm can be distinguished as separate line pairs.

Gamma cameras rely on collimation, which blurs fine details and reduces resolution, so they do not reach this level. MRI delivers high anatomic detail and is typically described in millimeter voxels rather than lp/mm, so its resolution isn’t characterized this way. Digital radiography improves efficiency and dynamic range but is usually limited by detector pixel size and sampling, often yielding fewer lp/mm than optimized screen-film setups.

Thus, among the options, screen-film radiography best achieves about 8 lp/mm, reflecting its superior inherent spatial resolution for fine detail.