MRI scanning of an intact implanted spinal fusion stimulator produced safe temperature rises (<2°C), but a broken lead wire caused unsafe heating (11-14°C), necessitating prior radiological checks.
Does an implanted spinal fusion stimulator cause unsafe RF heating during 1.5 T MRI scans?
MRI at 1.5 T is safe for intact spinal fusion stimulators but unsafe if a lead wire is broken, necessitating radiological confirmation of implant integrity prior to scanning.
Radio frequency (RF) heating of an implanted spinal fusion stimulator (SpF) during magnetic resonance imaging (MRI) was studied on a full-size human phantom. Heating during MRI scans (GE Signa 4X, 1.5 T) was measured with RF-transparent fiberoptic sensors. With the implant correctly connected, the maximum temperature rises were less than 2 degrees C during the 26 min that the scans were at maximum RF power. At the tip of a broken stimulator lead (connecting the SpF generator and its electrodes), the maximum temperature rise was 11-14 degrees C. Regular 4-min scans of the spinal cord produced similar temperature rises at the broken tip. After the generator and the leads were removed, heating at the electrode connector tip was less than 1.5 degrees C. The control temperature rises at the same locations, without the stimulator, were less than 0.5 degree C. This study shows that spinal fusion stimulator heating is within the Food and Drug Administration safety guideline of 2 degrees C. However, if a lead wire is broken, it is unsafe during MRI scans. Radiological examinations will be necessary to ensure the integrity of the implant.
Chou et al. (Thu,) conducted a other in Implanted spinal fusion stimulator during MRI. MRI scan (1.5 T) with implanted spinal fusion stimulator vs. Control temperature rises without the stimulator was evaluated on Maximum temperature rise. MRI scanning of an intact implanted spinal fusion stimulator produced safe temperature rises (<2°C), but a broken lead wire caused unsafe heating (11-14°C), necessitating prior radiological checks.