Which modality has the highest resolution among the listed?

• A. Gamma camera
• B. MRI and CT
• C. Computed radiography
• D. Screen-Film Radiography

Answer: (D)

Understanding resolution means looking at how finely a modality can depict small details. Traditional screen-film radiography forms the image directly on film with very fine grain and minimal intermediate sampling, so it can render sharp edges and tiny structures with exceptional detail. In contrast, a gamma camera image relies on collimation to locate photons, and that collimation inherently blurs the image, producing lower spatial resolution. MRI and CT can show fine anatomical structures, but their practical resolution is limited by voxel or pixel size and acquisition parameters, and is typically not as fine as the sharpness achievable with film-screen radiography for many anatomic details. Because of these factors, the modality with the highest spatial resolution among the listed options is screen-film radiography.