gms | German Medical Science

Objective: Spinal cord stimulation (SCS) is an invasive treatment option for various chronic neuropathic pain syndromes. An estimated number of 1500 implants per year are performed in Germany. Because of the expanding indications and increasing number of magnetic resonance imaging-examinations it is of most importance that implanted materials are MRI-conditional. In detail, the MRI-scan with the body-coil is the significant problem for all ferromagnetic implants. A recent overview of the available SCS implants with respect to the MRI-conditionality and the clinical experience will be presented.

Methods: Different stimulation devices of at least four companies are available for SCS in Germany. Usually, a SCS implantable system mostly consists of a lead, an extension and a stimulation device. The main risk of MRI-scanning with ferromagnetic implants is the heating and thus tissue damage around the devices, in first instance the lead. Since January 2013 a neurostimulation device with a new designed lead and a modified impulse generator is approved for SCS and 1.5 Tesla MRI-scanning with the body-coil. In 2016 another SCS device received the approval for MRI full-body-scan with the body coil in 1.5 Tesla scanners.

Results: In more than 70 patients a MRI-conditional SCS device was implanted. In each case the stimulation lead were directly connected to the stimulation device and no extensions were used. Prior to the MRI-scanning an impedance measurement was carried out and, in case of normality, the device was switched off to an MRI-safety mode. Different MRI-scans with adapted scan parameters were performed in the implanted patient sample, e. g. lumbar spine, heart, breast etc. No adverse events or technical failures of the implanted materials were noted. Also no complaints or discomfort were reported by the patients during or following the MRI-scans. Only local distortion or minor artifacts were seen on the MRI-scans at the site of the implanted materials, but these did not influence the image quality and evaluation.

Conclusion: In all de novo SCS procedures the use of MRI-conditional implants is recommended. Therefore all companies should make the effort that future devices for SCS achieve the approval for full-body MRI-scanning with a body-coil, at least in 1.5 Tesla scanners. Additionally detailed patient information and a standardized safety protocol for radiologists conducting MRI-examinations in patients with SCS should be easily available and strictly followed.