Final answer:
Lateral resolution is the capability to distinguish two objects side by side or parallel to the ultrasound beam, which is option (C). This is distinct from axial resolution and is governed by principles such as the Rayleigh criterion.
Step-by-step explanation:
Lateral resolution in an ultrasound (US) is a critical aspect when we consider image clarity and detail. It is defined as the ability of the imaging system to differentiate two reflectors that are side by side or parallel to the ultrasound beam. Given the choices provided, the correct option for lateral resolution is (C) The ability to differentiate two reflectors that are parallel to the US beam.
It is important to understand that lateral resolution differs from axial resolution, which is the ability to distinguish objects that are in front of or behind each other along the path of the ultrasound beam. Diffracts and the Rayleigh criterion further elaborate on this concept by stating two images are just-resolvable when the center of the diffraction pattern of one image is directly over the first minimum of the diffraction pattern of the other.