It is very common for biliary pain to refer to the back, typically near the tip of the right shoulder blade. The slight ductal dilatation may well represent a component of sphincter of Oddi dysfunction. I agree with the cholecystectomy but there is a chance that you may continue to have symptoms post op and ultimately require a sphincterotomy which is done endoscopically. Generally, the gallbladder must be out of the system before this diagnosis is detected.
Thank you for your help. I'm scheduled for surgery in 3 days and I'm still not sure if it is the right thing to do. I'll post a comment after surgery....if I have it. Thank you!