Which statement is most accurate about screen-film mammography resolution?

• A. It is measured in lp/mm and has a practical limit near 15 lp/mm
• B. It is unrelated to image sharpness
• C. It can exceed 50 lp/mm with standard equipment
• D. It is determined solely by exposure time

Answer: (A)

Spatial resolution in screen-film mammography is about how finely details can be distinguished, and it is expressed in line pairs per millimeter (lp/mm). In conventional screen-film systems, the practical limit is around 15 lp/mm because the image blur comes from several unavoidable sources: the finite size of the x-ray focal spot creates geometric blur, the screen-film interface adds detail loss, and imperfect contact between screen and film plus processing steps further degrade sharpness. Motion during exposure can worsen this, but the most influential factor is the overall blur built into the system, which caps how much detail can be resolved. So describing resolution with lp/mm and a practical ceiling near 15 lp/mm aligns with how these systems perform in typical practice. Other statements aren’t accurate because resolution is indeed tied to image sharpness, it isn’t realistic for standard equipment to reach 50 lp/mm, and resolution isn’t determined solely by exposure time—many geometric and processing factors set the limit.