What term describes the depth discrimination ability of ultrasound?

What term describes the depth discrimination ability of ultrasound?

• A. Depth resolution
• B. Range resolution
• C. Axial resolution
• D. Temporal resolution

Answer: (B)

Depth discrimination along the ultrasound beam is described by range resolution. This is the system’s ability to distinguish two reflectors at different depths along the same scan line as separate echoes. The key factor here is the pulse length: shorter spatial pulse length yields finer depth discrimination, so echoes from two closely spaced depths can be resolved as distinct signals. Because echoes travel to the reflector and back, axial (range) resolution is effectively half the spatial pulse length and depends on how many cycles are in the pulse and the sound speed in tissue. So range resolution specifically captures how well you separate echoes by depth, which is exactly what we mean by depth discrimination. If you’re weighing related terms, axial resolution is often used synonymously with range resolution in this context, since both describe depth discernment along the beam. Temporal resolution, by contrast, concerns frame rate and motion over time, not how closely two depths can be distinguished.

Depth discrimination along the ultrasound beam is described by range resolution. This is the system’s ability to distinguish two reflectors at different depths along the same scan line as separate echoes. The key factor here is the pulse length: shorter spatial pulse length yields finer depth discrimination, so echoes from two closely spaced depths can be resolved as distinct signals. Because echoes travel to the reflector and back, axial (range) resolution is effectively half the spatial pulse length and depends on how many cycles are in the pulse and the sound speed in tissue. So range resolution specifically captures how well you separate echoes by depth, which is exactly what we mean by depth discrimination.

If you’re weighing related terms, axial resolution is often used synonymously with range resolution in this context, since both describe depth discernment along the beam. Temporal resolution, by contrast, concerns frame rate and motion over time, not how closely two depths can be distinguished.