Safety of intrauterine contraceptive devices during MR imaging.

Three intrauterine contraceptive devices (IUD) were examined in an experimental in vitro setup to test their MR compatibility: Multiload CU375. Nova T (containing copper and silver), and Gyne T. The devices were fixed in a polyacrylamide gel and exposed to the magnetic field and the radiofrequency (RF) of standard MR sequences (spin-echo, turbo-spin-echo, turboFLASH, and magnetization transfer prepared FLASH). The RF power of a turbo-spin-echo sequence was increased by a factor of 5. Temperatures of the IUDs and the gel were measured during the MR examination. No deflection of the IUDs exposed to the magnetic field of 1.5 Tesla was detected. Under normal imaging conditions no temperature increase could be observed. Using an increased RF power, a maximal temperature rise of 0.4 degree C per examination was seen. No differences between the gel and the IUDs were observed, indicating that there is no specific heating of the tested IUDs.