I had Titanium clips used to seal off blood vessels after my bilateral mastectomy. I also had no idea they were there until I had a chest X ray of my shoulder, which showed a whole lot of them. They looked like grains of rice. When I asked my surgeon at my next check up why I hadn't been told, the cheeky so and so said she didn't feel it was necessary as they are routinely used and are quite safe for MRI tests as they are not magnetic. When I said that I would still like to have known about them she added "Well I didn't tell you what size scalpel I used, or what sutures were used..." I was not impressed. X ray showing some of them.