Is it safe for a patient who has undergone lumbar fusion with MRI‑compatible (titanium) pedicle screws and rods to undergo an MRI?

MRI Safety After Lumbar Fusion

Yes, patients with lumbar fusion hardware can safely undergo MRI, and MRI remains the preferred imaging modality for evaluating new or progressive symptoms after lumbar fusion surgery. 1

MRI Safety with Modern Spinal Hardware

Modern spinal fusion hardware, particularly titanium constructs, is MRI-safe and does not pose a contraindication to MRI at 1.5T or less. 1 This is a critical point that is often misunderstood in clinical practice.

Material-Specific Considerations

• Titanium implants produce significantly fewer artifacts in the spinal canal compared to stainless steel implants, making them superior for postoperative MRI imaging 2, 3
• Titanium offers superior MRI and CT resolution with significantly less signal interference compared to stainless steel 4
• Shorter screws, wider screw placement, and thinner titanium plates produce the least imaging artifacts 3

Optimal Imaging Protocol Selection

For patients with prior lumbar surgery and new or progressive symptoms, MRI lumbar spine without and with IV contrast is the most useful initial imaging study. 1

When to Use Contrast

• Contrast administration accurately distinguishes recurrent or residual disc herniations from postoperative scar tissue 1
• Contrast helps evaluate nerve root compression or arachnoiditis in the post-surgical spine 1
• New or progressive radiculopathy after fusion should be evaluated with MRI with and without contrast 1
• Suspected infection or abscess requires MRI with and without contrast 1

Best MRI Sequences to Minimize Artifacts

• Spin echo (T1), turbo spin echo (T1, T2), and half Fourier single shot turbo spin echo (HASTE) sequences produce the best images with metallic implants 3
• Avoid sequences containing gradient echo components (gradient echo, turbo gradient and spin echo, or frequency-selective fat saturation techniques) as these result in the highest amount of image degradation 3

When MRI is Limited by Artifact

When metallic artifact significantly limits MRI diagnostic quality, CT myelography is the preferred alternative imaging modality. 1

• CT myelography effectively assesses spinal canal patency, neural foramina, and nerve root compression despite the presence of hardware 1
• For hardware integrity concerns specifically, use CT without contrast 1

Common Pitfalls to Avoid

• Do not assume all spinal hardware is MRI-unsafe – this outdated assumption prevents patients from receiving optimal diagnostic imaging 1
• Do not rely on plain radiographs alone for postoperative evaluation, as they have only 64-69% accuracy for detecting complications with significant interobserver variability 5, 6
• Do not skip contrast in post-surgical patients with new symptoms, as contrast is essential for distinguishing scar from recurrent disc herniation 1
• Do not order MRI without specifying the appropriate sequences – communicate with radiology to avoid gradient echo-based sequences that maximize artifact 3

Clinical Decision Algorithm

1. Patient with lumbar fusion hardware + new symptoms → Order MRI lumbar spine with and without contrast 1
2. If MRI quality is severely degraded by artifact → Proceed to CT myelography 1
3. If concern is hardware integrity/loosening → Order CT without contrast 1
4. Ensure titanium hardware was used if possible for future imaging considerations 2, 3