Signal Intensity on MRI is equivalent to which term used in CT imaging?

Signal Intensity on MRI is equivalent to which term used in CT imaging?

• A. Density
• B. Attenuation
• C. Contrast
• D. Signal Intensity

Answer: (D)

Brightness in MRI is determined by signal intensity—how strongly a voxel emits signal based on proton density and relaxation properties. In CT, brightness is determined by how much X-rays are attenuated by tissue, quantified as attenuation (often described as density on the image). So the CT term that best matches MRI signal intensity is attenuation (density). Contrast refers to differences between tissues, not the absolute brightness of a voxel, so it’s not the direct equivalence.

Brightness in MRI is determined by signal intensity—how strongly a voxel emits signal based on proton density and relaxation properties. In CT, brightness is determined by how much X-rays are attenuated by tissue, quantified as attenuation (often described as density on the image). So the CT term that best matches MRI signal intensity is attenuation (density). Contrast refers to differences between tissues, not the absolute brightness of a voxel, so it’s not the direct equivalence.