Metallic spinal artifacts in magnetic resonance imaging

Area of Science:

• Medical Imaging
• Biomaterials Science
• Neurosurgery

Background:

• Surgical implants, including metallic components, can cause artifacts in magnetic resonance imaging (MRI).
• Understanding artifact susceptibility is crucial for accurate postoperative spinal imaging.
• Previous studies have explored metallic artifact generation, but comparative analysis across different sequences and alloys is ongoing.

Purpose of the Study:

• To quantitatively compare void artifact susceptibility of aluminum, titanium, and stainless steel surgical metals using MRI.
• To evaluate artifact differences between spin echo and gradient echo sequences.
• To assess the impact of stainless steel alloy composition on MRI artifact.

Main Methods:

• Human thoracic spine models with deposited metallic filings were imaged using spin echo and gradient echo sequences.
• Void artifact was quantified and compared across different metallic alloys and a liquid paraffin control.
• Two blinded neuroradiologists rated artifact severity on a scale of 1 to 4.

Main Results:

• Artifact magnitude generally correlated with metal magnetism.
• 316L stainless steel produced less artifact than 304 stainless steel on gradient echo imaging due to nickel content stabilizing iron.
• No significant artifact was observed with any metal in all spin echo sequences.

Conclusions:

• Stainless steel should be suspected if significant artifact is seen on postoperative gradient echo imaging.
• Spin echo techniques are recommended for optimal visualization of the spinal cord and soft tissues in the presence of suspected metallic artifacts.
• The choice of MRI sequence is critical for minimizing artifact and ensuring diagnostic accuracy after spinal surgery involving metallic implants.