Can a patient with a spinal (Spinal Cord Stimulator) undergo a lumbar Magnetic Resonance Imaging (MRI)?

MRI Safety with Spinal Cord Stimulators: A Conditional Yes with Critical Precautions

Lumbar MRI can be performed in patients with spinal cord stimulators using modified protocols with reduced specific absorption rate (SAR), but this requires manufacturer-specific device compatibility verification, informed consent about risks including device damage and thermal injury, and close monitoring during the procedure. 1

Device-Specific Compatibility Assessment

• First, verify the specific manufacturer and model of the spinal cord stimulator, as MRI compatibility varies dramatically between devices 1, 2
• Devices implanted before July 2013 are generally NOT MRI-compatible and carry significant risk of thermal injury at lead and generator sites 3
• Some modern SCS systems have conditional MRI approval with specific scanning parameters that must be strictly followed 3
• Contact the device manufacturer directly to obtain written MRI compatibility guidelines for the specific model implanted 1, 2

Modified MRI Protocol Requirements

When MRI is deemed necessary despite SCS presence:

• Use 1.5 Tesla field strength only - higher field strengths increase risk 1
• Implement reduced specific absorption rate (SAR) protocols that limit transmitted energy 1
• Scan only the anatomic region distant from the pulse generator when possible to minimize artifact and risk 4
• Expect image quality degradation (rated slightly inferior to standard imaging) particularly near hardware 1

Clinical Risk-Benefit Analysis

Proceed with MRI only when:

• New neurological deficits develop that require urgent imaging (e.g., progressive myelopathy, cauda equina syndrome) 5
• Alternative imaging modalities (CT, CT myelography) cannot provide necessary diagnostic information 6
• The diagnostic information will directly change clinical management 1
• 69.2% of patients in one series had clinically relevant findings that affected treatment, justifying the risk when appropriately indicated 1

Do NOT proceed with routine surveillance imaging or when clinical assessment is stable 6

Documented Adverse Events and Monitoring

Potential complications include:

• Device malfunction requiring pulse generator replacement - documented in case reports where output circuitry switches were damaged by radiofrequency current 2
• Transient warm sensations at electrode sites (23% of patients) 1
• Brief intense shocking sensations during and after scanning 2
• Thermal injury risk at lead and generator sites 3
• No permanent neurological deficits reported in prospective series, but close monitoring is mandatory 1

Mandatory Patient Counseling and Consent

Before proceeding, document discussion of:

• Risk of permanent device damage requiring surgical replacement 2
• Potential for thermal injury at implant sites 3
• Possibility of uncomfortable sensations during scanning 1
• Need for device interrogation and potential reprogramming after MRI 2
• Alternative imaging options including CT or explantation for critical imaging needs 3

Post-MRI Device Management

• Immediately interrogate the SCS device after MRI to assess for parameter changes or malfunction 4, 2
• Test all stimulation programs to ensure proper function 2
• Document any patient-reported changes in stimulation quality or comfort 1
• Be prepared for device replacement if malfunction is detected 2

Alternative Imaging Strategies

When MRI compatibility cannot be confirmed:

• CT with contrast can evaluate for infection, hardware complications, or mass lesions 6
• FDG-PET/CT has 94.8% sensitivity for spine infection when MRI is contraindicated 6
• Surgical explantation of SCS device may be necessary for critical diagnostic imaging - 4 of 33 explanted devices in one series were removed specifically to obtain MRI 3

Critical Pitfall to Avoid

Never assume all spinal cord stimulators are MRI-compatible - this is the most dangerous misconception. Each device requires individual verification, and proceeding without manufacturer confirmation risks permanent device damage and patient injury 3, 2. The historical view that neurostimulators are an absolute contraindication has been challenged, but this does not mean all devices are safe 1.