If wires in an AIUM test object do not appear in the same place as on the display, what is amiss?

• A. registration accuracy
• B. dynamic range accuracy
• C. near gain
• D. gray scale dynamic range

Answer: (A)

The key idea is spatial alignment between what’s in the phantom and what appears on the screen. When wires in the AIUM test object don’t line up with their fixed, known positions on the display, it means the system isn’t mapping the real geometry of the object to the image correctly. That misalignment is what registration accuracy measures.

Dynamic range-related issues would alter how bright or dark the image appears across depths, and near gain or gray-scale dynamic range affect brightness and contrast, not where objects show up on the screen. So the observed displacement specifically points to a problem with registration accuracy.