Increasing slice thickness will degrade elevational resolution.

Increasing slice thickness will degrade elevational resolution.

• A. Improve
• B. Degrade
• C. No change
• D. Improve only at shallow depths

Answer: (B)

Elevational resolution is how well we can distinguish structures that lie above and below each other in the direction perpendicular to the imaging plane. This is determined by the slice thickness of the ultrasound beam in that direction. When slice thickness increases, signals from a larger volume are averaged together, causing partial-volume effects and blurring along the elevational axis. That blending makes boundaries less distinct and nearby structures harder to separate, so elevational resolution gets worse. To improve it, you’d want a thinner slice thickness; increasing thickness simply degrades the out-of-plane clarity.

Elevational resolution is how well we can distinguish structures that lie above and below each other in the direction perpendicular to the imaging plane. This is determined by the slice thickness of the ultrasound beam in that direction. When slice thickness increases, signals from a larger volume are averaged together, causing partial-volume effects and blurring along the elevational axis. That blending makes boundaries less distinct and nearby structures harder to separate, so elevational resolution gets worse. To improve it, you’d want a thinner slice thickness; increasing thickness simply degrades the out-of-plane clarity.