Which statement best describes tissue harmonic imaging?

Which statement best describes tissue harmonic imaging?

• A. It reduces grating lobe artifacts and improves lateral resolution.
• B. It worsens resolution.
• C. It increases attenuation.
• D. It reduces penetration.

Answer: (A)

Tissue harmonic imaging relies on the tissue’s nonlinear response to ultrasound, generating harmonics of the transmitted wave. Because these harmonics have a shorter wavelength, the formed image uses a narrower beam, which sharpens edges and improves lateral resolution. The higher-frequency harmonic signal is also less influenced by the grating lobes and side lobes typical of the array in fundamental imaging, so those artifacts are reduced. Taken together, this means tissue harmonic imaging tends to produce clearer borders and fewer artifacts, which is why it’s described as reducing grating lobe artifacts and improving lateral resolution. It isn’t about worsening resolution or increasing penetration; in practice, the benefit in image quality often comes with some trade-off in how deep the signals can be effectively detected due to greater attenuation at the harmonic frequency.

Tissue harmonic imaging relies on the tissue’s nonlinear response to ultrasound, generating harmonics of the transmitted wave. Because these harmonics have a shorter wavelength, the formed image uses a narrower beam, which sharpens edges and improves lateral resolution. The higher-frequency harmonic signal is also less influenced by the grating lobes and side lobes typical of the array in fundamental imaging, so those artifacts are reduced. Taken together, this means tissue harmonic imaging tends to produce clearer borders and fewer artifacts, which is why it’s described as reducing grating lobe artifacts and improving lateral resolution. It isn’t about worsening resolution or increasing penetration; in practice, the benefit in image quality often comes with some trade-off in how deep the signals can be effectively detected due to greater attenuation at the harmonic frequency.