Which statement about computed tomography is true?

• A. CT images are color for easy differentiation
• B. CT uses no ionizing radiation
• C. CT images are digital and film free
• D. CT cannot image bone

Answer: (C)

CT imaging creates cross-sectional pictures by using X-rays and detectors around the patient, with a computer reconstructing the data into slices. Because the data are processed and stored digitally, the images are digital and film-free; they’re viewed on monitors, archived electronically, and shared without needing photographic film. This is why the statement about CT images being digital and film-free is the true one. In contrast, CT does use ionizing radiation, so saying there is no ionizing radiation is incorrect. The standard CT image is displayed in grayscale to represent varying tissue densities, not in color, though some post-processing may add color overlays in specialized workflows. And CT can image bone very well—bone appears bright because it strongly attenuates X-rays—so the claim that CT cannot image bone is false.