Which imaging technique reduces acoustic speckle in ultrasound images?

• A. Compound imaging
• B. Harmonic imaging
• C. Doppler imaging
• D. B-mode

Answer: (A)

Speckle reduction in ultrasound is achieved by combining data from different angles, a technique known as spatial compounding. Speckle is the granular pattern created by interference of echoes from tiny structures; it makes images look noisy and can obscure edges. By acquiring data from multiple angles around the same region and averaging the results, the random speckle patterns tend to cancel out while the true tissue features stay consistent. The outcome is a cleaner image with better edge definition and improved contrast between structures. Harmonic imaging uses tissue-generated harmonics to improve resolution and reduce clutter, but its main purpose isn’t speckle suppression. Doppler imaging focuses on motion and flow, and standard B-mode imaging shows the natural speckle pattern. So, spatial compounding is the technique that best reduces acoustic speckle.