Grating lobes cause a _____ of the ultrasound beam and _____ lateral resolution.

Grating lobes cause a _____ of the ultrasound beam and _____ lateral resolution.

• A. Attenuation and No effect
• B. Narrowing and Enhanced
• C. Smearing and Degrade
• D. Sharpening and Improve

Answer: (C)

Grating lobes arise in an array when the element spacing is large relative to the ultrasound wavelength, producing secondary maxima in the beam away from the mainlobe. These off-axis lobes siphon energy from the central beam, so the lateral beam profile becomes broader and more dispersed rather than tight and focused. That broad, smeared lateral profile makes it harder to distinguish two reflectors that are side by side, which is exactly what lateral resolution measures. So grating lobes cause a smeared beam and degrade lateral resolution. Techniques like reducing element spacing or applying apodization help minimize grating lobes and preserve lateral sharpness.

Grating lobes arise in an array when the element spacing is large relative to the ultrasound wavelength, producing secondary maxima in the beam away from the mainlobe. These off-axis lobes siphon energy from the central beam, so the lateral beam profile becomes broader and more dispersed rather than tight and focused. That broad, smeared lateral profile makes it harder to distinguish two reflectors that are side by side, which is exactly what lateral resolution measures. So grating lobes cause a smeared beam and degrade lateral resolution. Techniques like reducing element spacing or applying apodization help minimize grating lobes and preserve lateral sharpness.