Coded excitation is used to improve which aspect of image quality?

• A. Improved lateral resolution
• B. Shorter pulse repetition period
• C. Improved contrast resolution
• D. Improved temporal resolution

Answer: (C)

Coded excitation works by sending a long, coded pulse that carries more energy while keeping peak intensity within safe limits, then using signal processing to compress the received echoes back to a short duration. This process boosts the signal-to-noise ratio, making echoes from tissue interfaces easier to detect against background noise. With a clearer signal, subtle differences in echogenicity become more distinguishable, improving the ability to separate adjacent tissues—i.e., contrast resolution. It doesn’t inherently shorten the pulse repetition period or directly enhance temporal resolution, and its primary impact is on the clarity of tissue contrast rather than lateral resolution.