The technique that improves contrast and spatial and axial resolution using a series of pulses and gaps in the pulser is known as?

• A. Code Excitation
• B. Cine Loop
• C. Edge Shadow
• D. Frame Rate

Answer: (A)

Code excitation uses a coded sequence of transmitted pulses with gaps, then relies on pulse compression at reception to shorten the pulse. This approach sends more energy overall than a single short pulse, which boosts the signal-to-noise ratio and penetration. When the received echoes are passed through a matched filter that correlates with the transmitted code, the long coded waveform is compressed into a very short, high-amplitude burst. That compression shortens the effective pulse length, improving axial resolution, while the higher energy reduces noise and enhances contrast resolution. In short, transmitting a series of pulses and gaps as a code and then compressing it on receive gives clearer, more detailed images with better contrast and resolution.