Of all the tests that I have had, this is the easiest to tolerate. Please don't stress over it unless you really can't lay still for a few minues. It is a dark, quiet room, the technician does everything to make you comfortable. You will be asked to hold your breath several times--at least I was--but it is not unpleasant. You'll be fine! It is nothing like an MRI or even a CT scan. Good luck!