Ultrasound finding: there is non homogeneous echo pattern deep to the trapezius muscle. what does this mean? mri was advised for better visual.

Irregular: Homogenous means the tissue all looks the same, non homogenous means that there is tissue under your trapezius that looks significantly different than the area around it. There can be a lot of possibilities, many of which are quite benign conditions. I agree that an mri is a much better test to evaluate this as the resolution is tremendously better than that of an ultrasound.