Technical challenges and safety of magnetic resonance imaging with in situ neuromodulation from spine to brain

Abstract

The increasing availability of devices conditional for 3 T MRI, whole-body transmit imaging, and imaging in the on-stimulation condition, will be of significant benefit to the growing population of patients benefitting from neuromodulation therapy, and open up new opportunities for functional imaging research.

Recognizing the Common Origins of Dystonia and the Development of Human Movement: A Manifesto of Unmet Needs in Isolated Childhood Dystonias

“…But for any field to prosper we must be prepared to look elsewhere for examples of success and also applications of successful neuromodulation interventions, for instance, in the management of chronic pain (96) and bladder and bowel incontinence (97) where neuromodulation can make a significant positive impact. We must also evaluate the childhood brain and define stimulation targets in appropriate targets of the motor conectome in children (98) and ensure preservation of cognitive (99) function and accept the technical challenges of new imaging techniques to safely work with neuromodulation systems (100). …”

Removal of Sacral Nerve Stimulation Devices for Magnetic Resonance Imaging: What Happens Next?

“…Only 16 (76%) patients explanted ultimately underwent MRI, a median of 13 [3][4][5][6][7][8][9][10][11][12][13][14][15][16] days after device removal. Three studies took place before Medtronic's April 2012 announcement regarding the safety of MRI-head studies with SNM devices in situ; the remainder were after this announcement.…”

“…Indeed, data regarding SNM compatibility with MRI are limited. When bench-top MRI safety testing was conducted with patient-equivalent phantoms and a magnetic field representative of a 1.5T magnet, the magnetic forces acting on the tested Medtronic Activa battery (similar to the InterStim battery) were less than the force of gravity (4,7).…”

“…However, patients with SNM devices are cautioned not to undergo magnetic resonance imaging (MRI) of sites other than the head (2) due to concern for generator and/or lead migration, heating, changes in the SNM device program, or damage to implanted components (3). Moreover, there are additional concerns that in situ neuromodulation devices may decrease the quality of the images produced in an MRI study (4). The device manufacturer, Medtronic, conducted a series of in vitro studies, which led to a 2012 statement deeming its InterStim Model II 3058 series and select serial numbers of its 3023 series systems to be "MRI conditional," with adequate data to support the safety of head MRI via a 1.5T magnet using transmit/receive.…”

A Comprehensive Practice Guideline for Magnetic Resonance Imaging Compatibility in Implanted Neuromodulation Devices

“…High rate of change of field strengths have been theorized to induce currents with sufficient voltage to interfere with device functioning or damage the IPG (17). Furthermore, the RF pulses during MRI elicit dielectric energy absorption that can be channeled by conducting materials within implants resulting in increased temperature and risk for thermal injury along leads (17,18). Other risk factors include spatial gradient and specific absorption rates.…”