Well i had met up wit an accident where i hurt my shoulder,leg and hand.. I was badly injured on my left shoulder,where i was unable to move my neck and my shoulder.I did an X-ray that showed normal.When i did an ultra sonography revealed mild cortical irregularity involving greater tuberosity of Lt. humerus-could be sequele to trauma.So the doctor then advised a MRI to better understand why my pain was so severe.
The MRI and the US seem to show similar results, perhaps the US will show tendon ruptures more easily and the MRI things like effusions that is the swelling. The main thing is not the pictures but what is it you are suffering from. Have you weakness, not from pain but true weakness, have you loss of movement, what can you not do. Also, how long since you had the accident?