Which type of resolution is most affected by wavelength?

Axial resolution is most affected by wavelength because it is defined as the ability of the ultrasound system to distinguish two structures that are positioned along the direction of the ultrasound beam. This resolution is determined primarily by the spatial pulse length, which is a function of the wavelength of the emitted sound wave.

Shorter wavelengths provide better axial resolution because they result in shorter pulse lengths, allowing for the differentiation of closely spaced structures. When the wavelength is shorter, the ability to resolve two closely spaced interfaces is enhanced, leading to improved imaging quality.

In contrast, lateral resolution is influenced more by factors such as the beam width rather than wavelength alone, since it pertains to the ability to distinguish between objects that are positioned side by side rather than along the beam’s path. Temporal resolution is related to the frame rate and the time it takes to acquire and display images, while contrast resolution deals with the ability to differentiate between tissues based on brightness or echo intensity, which are influenced by system sensitivity and processing rather than wavelength.