Lateral resolution is commonly expressed as a function of which parameter?

Lateral resolution is commonly expressed as a function of which parameter?

• A. Frame rate
• B. Depth
• C. Beam width
• D. Wavelength

Answer: (C)

Lateral resolution is determined by how narrow the ultrasound beam is in the plane perpendicular to the beam direction. The key idea is that two reflectors that sit side by side will only appear as two distinct echoes if the beam is narrow enough to separate them. Therefore, the ability to distinguish those side-by-side features improves as beam width decreases, making beam width the primary parameter that expresses lateral resolution. Frame rate affects how often images are updated (temporal resolution) rather than the sharpness of side-by-side detail. Depth changes how far you image and can influence beam spread with distance, but it doesn’t set the intrinsic lateral sharpness. Wavelength influences axial resolution and penetration; its effect on lateral detail is indirect and usually secondary to the beam width that defines the lateral point-spread.

Lateral resolution is determined by how narrow the ultrasound beam is in the plane perpendicular to the beam direction. The key idea is that two reflectors that sit side by side will only appear as two distinct echoes if the beam is narrow enough to separate them. Therefore, the ability to distinguish those side-by-side features improves as beam width decreases, making beam width the primary parameter that expresses lateral resolution.

Frame rate affects how often images are updated (temporal resolution) rather than the sharpness of side-by-side detail. Depth changes how far you image and can influence beam spread with distance, but it doesn’t set the intrinsic lateral sharpness. Wavelength influences axial resolution and penetration; its effect on lateral detail is indirect and usually secondary to the beam width that defines the lateral point-spread.