Stupid Doctor
It's a test done in nuclear science. You lay on this table and for the first hour they inject you with something to see how your gallbladder fills, than the second hour they inject you with something else to see how it empties. You have to lay perfectly still but it's not painful. I had it because on my ultrasound I didn't show any stones but I did have some thickening of the gallbladder wall. The hidascan scan showed normal for function, it did empty a little slow but not enough to be considered a problem. Good luck!