What is one main advantage of using tissue harmonics?

• A. Improved penetration
• B. Improved temporal resolution
• C. Improved contrast resolution
• D. Improved signal-to-noise ratio

Answer: (C)

Tissue harmonic imaging works by using the second harmonic signal generated as sound travels through tissue, so the image is built from frequencies that are less affected by near-field clutter and transducer artifacts. This cleaner signal makes tissue interfaces—where echogenicity changes—stand out more clearly, so borders between different tissues and lesions become sharper and easier to distinguish. That enhanced delineation directly translates to better contrast resolution, which is why improved contrast resolution is the main advantage. Penetration tends to be worse with higher harmonic frequencies, temporal resolution is not the primary gain, and while clutter is reduced, the standout benefit relevant to how tissue types are separated is the improved ability to resolve contrasts between structures.