MRI contraindications

Contraindications

Cardiovascular Devices

• Coronary artery and peripheral vascular stents: most "MR safe" and "MR conditional" (check individual type)
• Aortic stent grafts:
  • Most "MR safe"
  • Zenith AAA and TAA endovascular grafts (Cook) = "MR conditional"
• Mechanical cardiac valves:
  • most prosthetic heart valves and annuloplasty rings = "MR safe"
  • Others ="MR conditional"
• Sternal wires = generally considered MR safe
• Cardiac closure and occluder devices
  • Majority of cardiac closure and occluder devices = "MR safe"
  • Several tested devices have been labeled as "MR conditional"
• Inferior vena cava filters:
  • Most "MR safe"
  • The remainder = "MR conditional"
  • Weakly ferromagnetic devices: can be performed after six weeks if clinically indicated as long as there is no reason to suspect that the device is not positioned properly or that it is not firmly in place
    • Gianturco bird nest IVC filter (Cook)
    • Stainless steel Greenfield vena cava filter (Boston Scientific)
• Embolization coils: most "MR safe"
  • The remainder = "MR conditional"
• Loop recorder (Event monitor) —
  • Reveal Plus ILR = "MR conditional."
  • May undergo MRI any time after implantation if there is no reason to believe the device is not well implanted
  • Stored data may be affected
• Hemodynamic monitoring and temporary pacing devices
  • "MR unsafe"
• Pulmonary artery hemodynamic monitoring/thermodilution catheters
  • Swan-Ganz catheter and similar catheters
  • Generally MR unsafe, unless otherwise specified
• Temporary pacemaker (external pulse generators or temporary pacing leads)
  • MR unsafe
• Permanent pacemakers and implantable ICDs
  • Generally considered a strong relative contraindication
  • Only if no alternative diagnostic test is available and the potential benefit to the patient clearly outweighs the potential risks
  • If performed, the pacemaker/ICD should be interrogated before and after the procedure
  • Risks:
    • pacemaker/ICD dysfunction
    • pacemaker/ICD damage
    • arrhythmia
    • death
  • Absolute contraindication (MR Unsafe): pacemakers or ICDs with known lead fractures
• Retained transvenous pacemaker and defibrillator leads
  • Approached same as those with pacemakers or ICDs (see above)
• Hemodynamic support devices (intraaortic balloon pump and ventricular assist devices)
  • Absolute contraindication (MR Unsafe)
• Nerve stimulators: MR Unsafe
• Cochlear implants: MR Unsafe
• Aneurysm clips
  • Requires specific information about the clip, particularly its material
    • Ferromagnetic: absolute contraindication
    • Nonferromagnetic or weakly ferromagnetic: MR safe

Non-Cardiovascular

• Dental materials (alloys, wires, splints, and prostheses): MR Safe
• Neurosurgical halo pins: MR unsafe?
• Transdermal patches
  • If contain aluminum or other metals (in non-adhesive backing): MR Unsafe (remove before MR)
    • Examples: certain clonidine, nicotine, scopolamine, testosterone, or fentanyl patches
• Unstable patient: MR conditional (probably should not unless there is an urgent clinical indication without acceptable alternative)
• Pregnancy: Unknown (if any, probably low)
  • Gadolinium-based contrast not recommended unless benefit justifies risk (crosses the placenta)

MR Contrast

• Pregnancy (see above)
• MR contrast agents and renal failure
  • Unlike iodinated contrast, MR contrast has few side effects and rarely cause anaphylaxis
    • Moderate to severe chronic kidney disease:
      • Contrast nephropathy can occur
      • Dialysis and hepatorenal patients in the perioperative liver transplant period
        • Associated nephrogenic systemic fibrosis (may be fatal)
        • MR Unsafe

Other

• Claustrophobia
• Agitated
• Very Obese (depending on system)