Rayleigh scattering occurs with reflectors that are what size in relation to the wavelength?

Rayleigh scattering refers to the scattering of ultrasound waves when they encounter reflectors that are significantly smaller than the wavelength of the sound being used. This phenomenon is a fundamental principle in ultrasound imaging, as it explains how sound waves interact with small structures, such as red blood cells or other microscopic anatomical features.

When the size of the reflectors is much smaller than the wavelength, the scattered energy is distributed in all directions rather than being reflected back predominantly in one direction. This scattering effect is more pronounced at shorter wavelengths, which is why it is particularly relevant in ultrasound applications where high-frequency sound waves are used.

Understanding Rayleigh scattering is crucial for interpreting ultrasound images and recognizing how different tissues or structures may appear based on their size in relation to the wavelength of the ultrasound. This concept helps sonographers expect and analyze the types of echoes that will return from various tissues, enhancing their diagnostic capabilities.