No bad reaction to bone scan and I’ve had a minimum of 8 of them. You lay in scanner and it goes from head to toe examining each area. It takes about 20 min. They do inject the dye and then you come back 3 hours later for scan. You can eat and drink liquid during this time. I joke with the staff and say I pee green but you don’t! I hate to do as many as I have but I’m Stage 4 so they want to keep an eye on my situation. The last bone scan it actually said you could get more info from my CT scan. If I can’t get PET scan due to insurance then they do both CT and Bone scans at the same time. Plus your not in a capsule during scan it’s a machine over the top of you. Good luck!