Partial volume artifact is also known as slide thickness artifact.

Partial volume artifact is also known as slide thickness artifact.

• A. Slice thickness artifact
• B. Edge artifact
• C. Ring artifact
• D. Shadowing

Answer: (A)

Partial volume effects happen when a single CT voxel contains more than one tissue density, so the measured attenuation is an average of those tissues. This averaging blurs boundaries and can misrepresent the true composition at interfaces. The degree of this averaging depends on how thick each slice is: thicker slices sample more tissue along the z-axis, increasing the mixing and producing the slide thickness, or slice thickness, artifact. That’s why this artifact is known as slice thickness artifact—the fading of sharp detail and incorrect density at interfaces arise from the finite slice thickness. To minimize it, thinner slices or higher-resolution reconstructions reduce the amount of averaging. Other choices describe different problems: ring artifacts come from detector calibration issues and appear as circular rings; shadowing and edge-related artifacts stem from beam hardening, photon starvation, or reconstruction limitations rather than from averaging across a slice.

Partial volume effects happen when a single CT voxel contains more than one tissue density, so the measured attenuation is an average of those tissues. This averaging blurs boundaries and can misrepresent the true composition at interfaces. The degree of this averaging depends on how thick each slice is: thicker slices sample more tissue along the z-axis, increasing the mixing and producing the slide thickness, or slice thickness, artifact. That’s why this artifact is known as slice thickness artifact—the fading of sharp detail and incorrect density at interfaces arise from the finite slice thickness. To minimize it, thinner slices or higher-resolution reconstructions reduce the amount of averaging.

Other choices describe different problems: ring artifacts come from detector calibration issues and appear as circular rings; shadowing and edge-related artifacts stem from beam hardening, photon starvation, or reconstruction limitations rather than from averaging across a slice.