Two benefits of tissue harmonic imaging include which of the following options?

Two benefits of tissue harmonic imaging include which of the following options?

• A. Grating lobe artifacts are reduced and lateral resolution is improved.
• B. Axial and lateral resolutions are improved.
• C. Contrast and axial resolution are improved.
• D. Penetration is improved and axial resolution is improved.

Answer: (A)

Tissue harmonic imaging works by using the second harmonic signal generated as ultrasound travels through tissue, which tends to produce cleaner echoes than the fundamental frequency. The cleaner, more localized harmonic signal reduces off-axis energy that creates artifacts, so grating lobe artifacts are diminished. At the same time, the harmonic image benefits from a narrower effective beam and higher frequency content, which sharpens tissue interfaces and improves lateral resolution. Axial resolution is more influenced by wavelength and bandwidth, and penetration can actually be limited with higher frequencies, so those benefits are not the primary takeaway. This combination—fewer grating lobe artifacts and better lateral detail—best represents the two main advantages of tissue harmonic imaging.

Tissue harmonic imaging works by using the second harmonic signal generated as ultrasound travels through tissue, which tends to produce cleaner echoes than the fundamental frequency. The cleaner, more localized harmonic signal reduces off-axis energy that creates artifacts, so grating lobe artifacts are diminished. At the same time, the harmonic image benefits from a narrower effective beam and higher frequency content, which sharpens tissue interfaces and improves lateral resolution. Axial resolution is more influenced by wavelength and bandwidth, and penetration can actually be limited with higher frequencies, so those benefits are not the primary takeaway. This combination—fewer grating lobe artifacts and better lateral detail—best represents the two main advantages of tissue harmonic imaging.