Which pairing correctly identifies the resolution type with its direction?

Which pairing correctly identifies the resolution type with its direction?

• A. Axial resolution - lateral plane
• B. Lateral resolution - depth direction
• C. Elevational resolution - out-of-plane direction
• D. Temporal resolution - frame rate

Answer: (C)

Understanding how resolution maps to spatial directions helps explain this pairing. Axial resolution is about distinguishing two reflectors along the direction the ultrasound beam travels, so it’s a depth (along the beam) measure. Lateral resolution concerns separation across the image plane, side-to-side within that plane. Elevational resolution, however, deals with the slice thickness—the dimension perpendicular to both the depth and the in-plane directions—so it corresponds to the out-of-plane direction. Temporal resolution is about how quickly frames are acquired over time, not a spatial direction. Because elevational resolution reflects the out-of-plane (slice thickness) direction, that pairing is the correct one.

Understanding how resolution maps to spatial directions helps explain this pairing. Axial resolution is about distinguishing two reflectors along the direction the ultrasound beam travels, so it’s a depth (along the beam) measure. Lateral resolution concerns separation across the image plane, side-to-side within that plane. Elevational resolution, however, deals with the slice thickness—the dimension perpendicular to both the depth and the in-plane directions—so it corresponds to the out-of-plane direction. Temporal resolution is about how quickly frames are acquired over time, not a spatial direction. Because elevational resolution reflects the out-of-plane (slice thickness) direction, that pairing is the correct one.