Spinal cord stimulators (SCS) are implanted medical devices that deliver mild electrical pulses to the spinal cord to help manage chronic pain. These devices are used for a variety of conditions, including failed back surgery syndrome and complex regional pain syndrome. MRI is a diagnostic tool widely used to create detailed images of organs and tissues. Understanding how these two interact is important for individuals with an SCS.
Understanding MRI Compatibility
It is possible to have an MRI scan with a spinal cord stimulator, but only under specific conditions. MRI machines generate strong magnetic fields and radiofrequency (RF) energy, which can interact with metallic implanted devices like an SCS. This interaction raises concerns about potential issues such as heating of the device or surrounding tissue, movement of the device within the body, damage to the stimulator, and interference with the quality of the MRI images.
Older SCS devices were often considered “MRI-unsafe” or “MRI-incompatible,” meaning an MRI was generally not advised due to these risks. However, advancements in technology have led to the development of “MRI-conditional” devices. These newer SCS systems are designed to be safely scanned under specific parameters and guidelines provided by the manufacturer.
Factors Determining Compatibility
Several factors determine whether a patient with an SCS can safely undergo an MRI. The specific type and model of the SCS device are paramount. Many newer SCS systems are labeled as “MRI-conditional,” meaning they are safe for MRI under certain circumstances, while older or non-conditional devices may not be.
The strength of the MRI magnet, measured in Tesla (T), also plays a role. Some SCS devices might be conditional for lower field strengths, such as 1.5 Tesla, but not for higher strengths like 3 Tesla. The location of the MRI scan relative to the SCS implant can also influence compatibility; some devices may be conditional for head or extremity scans but not for full-body imaging, especially with older percutaneous leads versus surgically implanted paddle leads.
Essential Precautions and Procedures
Before an MRI scan, consulting with the pain management specialist or neurosurgeon who manages the SCS is necessary. This specialist will identify the exact SCS model and manufacturer to determine its MRI compatibility based on the device’s labeling and check its specific MRI conditions.
MRI-conditional devices often require specific programming adjustments before the scan. This might involve temporarily turning off the stimulator or setting it to a particular mode to ensure safety and prevent damage during the imaging process. It is also important to inform the MRI technologist about the implanted SCS device before the scan begins. Following the MRI, the SCS typically needs to be checked and potentially reprogrammed by the physician to restore its original therapy settings.
Potential Risks of Non-Compliance
Undergoing an MRI without proper precautions or with an incompatible SCS carries several risks. One concern is patient injury, which can include tissue heating around the SCS site or even burns. Strong magnetic fields can also cause the device or its leads to move within the body, potentially leading to further injury.
Beyond direct patient harm, there is a risk of the SCS device malfunctioning or sustaining permanent damage. This could result in a loss of pain therapy, requiring the device to be replaced, which would necessitate additional surgery. Furthermore, the presence of an incompatible device can lead to image degradation, producing artifacts on the MRI scans that make them unusable for diagnostic purposes.