Are brain aneurysm coils Magnetic Resonance Imaging (MRI) compatible?

Brain Aneurysm Coils Are MRI Compatible

Brain aneurysm coils are generally MRI compatible, but care should be taken to ensure the specific coils are verified as compatible with the MRI scanner environment before imaging. 1

MRI Compatibility of Aneurysm Coils

Safety Profile

• Guglielmi detachable coils (GDCs), which are platinum microcoils commonly used for endovascular treatment of intracranial aneurysms, have been specifically tested and shown to be MRI compatible 2, 3
• These coils display:
  • Very low level of MR artifacts
  • No ferromagnetism (no magnetic field attraction)
  • No significant heat production (only 0.2°C temperature increase during MRI)
  • No adverse events in clinical use 3

Imaging Considerations

When performing MRI on patients with coiled aneurysms:

1. Susceptibility artifacts: While coils are MRI compatible, they do create some imaging artifacts

   • Artifacts are relatively mild compared to the actual size and shape of the coil 3
   • These artifacts can affect image quality in the immediate vicinity of the coil

2. Follow-up imaging: MRA is recommended for surveillance of treated aneurysms 1

   • MRA has a sensitivity of 86% and specificity of 84-89% for detecting residual aneurysm after coiling 1
   • Both time-of-flight and contrast-enhanced MRA techniques can be used effectively

3. Potential limitations:

   • MRA may underestimate the size of residual or recurrent aneurysms due to susceptibility artifacts 1
   • In some cases, DSA (digital subtraction angiography) may be necessary for definitive evaluation 1

Clinical Protocol for MRI in Patients with Aneurysm Coils

1. Verify coil compatibility: Ensure the specific type of coil used is MRI compatible

   • Most modern coils are designed to be MRI compatible at 1.5T or less 3

2. Select appropriate imaging protocol:

   • For routine follow-up, MRA is reasonable and recommended (Class IIa; Level of Evidence C) 1
   • Consider contrast-enhanced MRA for better visualization of complex flow dynamics 1

3. Interpret with caution:

   • Be aware that susceptibility artifacts may affect visualization around the coil
   • DSA remains the most sensitive imaging for follow-up of treated aneurysms when definitive evaluation is needed 1

Important Considerations

• The American Heart Association/American Stroke Association guidelines support the use of MRA for follow-up of treated aneurysms 1
• Coil manufacturers have specifically designed modern aneurysm coils to be MRI compatible to facilitate follow-up imaging 2, 3
• For patients with multiple types of implants, verification of MRI compatibility for all devices is essential before scanning

By following these guidelines, MRI can be safely and effectively performed in patients with brain aneurysm coils, providing valuable follow-up information while minimizing risk to the patient.