Elevational resolution is determined by _______.

Elevational resolution is determined by _______.

• A. Beam slice thickness
• B. Elevation aperture
• C. Beam width
• D. Pulse repetition frequency

Answer: (A)

Elevational resolution is about how well you can distinguish two reflectors that lie above and below the imaging plane (in the elevation, or out-of-plane, dimension). The key factor shaping that ability is how thick the ultrasound beam is in that direction—the slice thickness. A thinner slice produces a narrower beam in elevation, so nearby structures separated vertically along that axis appear as distinct and can be resolved. A thicker slice blends them together through partial volume averaging, making separation harder and reducing elevational resolution. The other terms describe different aspects of the beam or imaging setup but don’t set the elevation detail in the same way. The beam width relates to the size of the beam across the plane and is more about lateral resolution. Pulse repetition frequency affects how fast data are acquired and the resulting temporal resolution, not the physical thickness of the beam in the elevational direction. Elevation aperture can influence beam shape but the primary determinant for elevational separation is slice thickness.

Elevational resolution is about how well you can distinguish two reflectors that lie above and below the imaging plane (in the elevation, or out-of-plane, dimension). The key factor shaping that ability is how thick the ultrasound beam is in that direction—the slice thickness. A thinner slice produces a narrower beam in elevation, so nearby structures separated vertically along that axis appear as distinct and can be resolved. A thicker slice blends them together through partial volume averaging, making separation harder and reducing elevational resolution.

The other terms describe different aspects of the beam or imaging setup but don’t set the elevation detail in the same way. The beam width relates to the size of the beam across the plane and is more about lateral resolution. Pulse repetition frequency affects how fast data are acquired and the resulting temporal resolution, not the physical thickness of the beam in the elevational direction. Elevation aperture can influence beam shape but the primary determinant for elevational separation is slice thickness.