the meniscus is not well shown. the iso - to hyperechoic region is posteriorly of the meniscal vessel. so it is difficult to do a real good interpretation in this static image. send me a dynamic view of, because there are also ligaments around the meniscus and it could be an artefact
you are right it is an probably an artefact; Power Doppler US highlights the presence of a small vessel just above the focal hyperechogenicity, stressing the probability of posterior enhancement due to the presence of blood (water) in the vessel.