Question: What changes do you have to make to a medical implant to make it radiopaque?

Lisa Phelan answered on 9 Nov 2014:

For an implantable endoprosthesis to be radiopaque, it must be made from a material possessing radiographic density higher than a surrounding host tissue and have sufficient thickness to affect the transmission of x-rays to produce contrast in the image. An implantable endoprosthesis may be made of metals including tantalum or platinum having relatively high radiographic densities. Other metals such as stainless steel, superalloys, nitinol, and titanium having lower radiographic densities may also be used.
It’s expensive to have a whole device radiopaque so we just have markers along the device, for example you could mark the start, middle and end of a balloon catheter to know you have it in the correct vessel area that’s blocked and needs reopening.