Lateral resolution describes how well an ultrasound machine can tell apart two structures that are positioned next to each other (perpendicular to the beam direction) at the same depth. It is determined primarily by the width of the ultrasound beam at a given depth, with narrower beams providing better resolution. Lateral resolution is generally poorest in the far field where the beam diverges, and best at the focal zone where the beam is narrowest. Sonographers can improve lateral resolution by adjusting the focal zone to the depth of interest, and higher-frequency transducers also tend to provide finer lateral detail.
Sonography Term