In B-mode imaging, which property is encoded along the Z-axis on a CRT display?

In B-mode imaging, which property is encoded along the Z-axis on a CRT display?

• A. Amplitude of the echo
• B. Time-of-flight
• C. Frequency shift
• D. Color

Answer: (A)

In B-mode imaging, the display uses brightness to represent the strength of each echo. The Z-axis on a CRT corresponds to how bright a dot is. So when an echo is strong (large amplitude), the dot lights up brighter; weaker echoes appear dimmer. This brightness encodes the echo amplitude. Time-of-flight relates to depth by where along the image depth the echo comes from, not to brightness. Frequency shift is a Doppler concept, used for velocity, not standard B-mode brightness. Color is used in color Doppler imaging, not B-mode brightness.

In B-mode imaging, the display uses brightness to represent the strength of each echo. The Z-axis on a CRT corresponds to how bright a dot is. So when an echo is strong (large amplitude), the dot lights up brighter; weaker echoes appear dimmer. This brightness encodes the echo amplitude.

Time-of-flight relates to depth by where along the image depth the echo comes from, not to brightness. Frequency shift is a Doppler concept, used for velocity, not standard B-mode brightness. Color is used in color Doppler imaging, not B-mode brightness.