Using a transducer with poor elevation resolution, which problem is most likely to occur?

Using a transducer with poor elevation resolution, which problem is most likely to occur?

• A. Inability to resolve two structures that lie close together and parallel to the path of the beam
• B. Inability to clearly demonstrate small cystic structures
• C. Inability to penetrate through dense tissue
• D. Inability to demonstrate rapidly moving structures accurately

Answer: (B)

Elevation resolution is about how thick the ultrasound beam is in the direction perpendicular to the image plane, i.e., the slice thickness. When this resolution is poor, the beam’s slice is thick, so small structures that occupy only a tiny part of that thickness get averaged with surrounding tissue. That partial-volume effect makes tiny cystic structures hard to distinguish and visualize clearly. So, the problem most likely to occur is the inability to clearly demonstrate small cystic structures. The other potential issues relate to different aspects of imaging—distinguishing objects along the beam path is tied to axial resolution, penetration through dense tissue depends on frequency and attenuation, and tracking rapidly moving structures relies on temporal (frame) resolution.

Elevation resolution is about how thick the ultrasound beam is in the direction perpendicular to the image plane, i.e., the slice thickness. When this resolution is poor, the beam’s slice is thick, so small structures that occupy only a tiny part of that thickness get averaged with surrounding tissue. That partial-volume effect makes tiny cystic structures hard to distinguish and visualize clearly.

So, the problem most likely to occur is the inability to clearly demonstrate small cystic structures. The other potential issues relate to different aspects of imaging—distinguishing objects along the beam path is tied to axial resolution, penetration through dense tissue depends on frequency and attenuation, and tracking rapidly moving structures relies on temporal (frame) resolution.