Yes I had one done. It is painless except for the needle that they put in your arm as an iv to put the dye into you. They let you sit in a dark comfortable room on a comfortable chair and you have to sit still like that for a bit so that the dye settles on you. Movement wll make it settle in the wrong places. It is a fast test after that, almost like an MRI or CAT Scan except you are not in a closed machine..... it is pain free test. Good luck with it.
My mom had one done this year. She is 73. It is painless as hellos mentioned too. My mom had to sit in a very comfortable recliner. They put something in her vein,but i don't recall it being a dye. she had to drink something red in color and after a while went in for the test. My mom is a big chicken when it comes to tests and she was fine with it.
Hope this has helped.