MRI contraindications

MR Contraindications

Cardiovascular Devices

Device	MR Category	Comments
Coronary artery stents	Most MR Safe (some MR Conditional)	Check individual type
Peripheral vascular stents	Most MR Safe (some MR Conditional)	Check individual type
Aortic stent grafts	Most MR Safe	Zenith AAA and TAA endovascular grafts (Cook) = MR Conditional
Mechanical cardiac valves (prosthetic heart valves and annuloplasty rings )	Most MR Safe (some MR Conditional)
Sternal wires	Generally considered MR safe
Cardiac closure and occluder devices	Most MR Safe (some MR Conditional)
IVC filters	Most MR Safe (some MR Conditional)	Weakly ferromagnetic devices [e.g. Gianturco bird nest IVC filter (Cook), stainless steel Greenfield vena cava filter (Boston Scientific)]: after six weeks as long as no reason to suspect improper positioning or movement
Embolization coils	Most MR Safe (some MR Conditional)
Loop recorder (Event monitor)	MR Conditional?	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 )	MR Unsafe (unless otherwise specified)
Temporary pacemaker (external pulse generators or temporary pacing leads)	MR Unsafe
Permanent pacemakers and implantable ICDs	Strong relative contraindication vs. MR Unsafe	Absolute contraindication: pacemakers or ICDs with known lead fractures
Retained transvenous pacemaker and defibrillator leads	Strong relative contraindication vs. MR Unsafe	Approached same as those with pacemakers or ICDs (see above)
Hemodynamic support devices (intraaortic balloon pump and ventricular assist devices)	MR Unsafe

Permanent pacemakers and implantable ICDs

• 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

Non-Cardiovascular

Device	MR Category	Comments
Nerve stimulators	MR Unsafe
Cochlear implants	MR Unsafe
Aneurysm clips	Ferromagnetic: MR Unsafe; Non/weakly-ferromagnetic: MR Safe	Requires specific information about clip material
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 avoid unless an urgent clinical indication without acceptable alternative

Other

• Pregnancy: Unknown (if any, probably low)
  • Gadolinium-based contrast not recommended unless benefit justifies risk (crosses the placenta)
• Claustrophobia
• Agitated
• Very Obese (depending on system)

MR (Gadolinium-Based) Contrast

Background

• Unlike iodinated contrast, MR contrast has few side effects and rarely cause anaphylaxis
• It does cross the placenta

Specific Groups

• Pregnancy (see above)
  • Gadolinium-based contrast not recommended unless benefit justifies risk
• Moderate to severe chronic kidney disease:
  • Contrast nephropathy can occur (MR Unsafe)
• Dialysis and hepatorenal patients in the perioperative liver transplant period
  • Associated nephrogenic systemic fibrosis (MR Unsafe)

Key

• MR Safe: Generally safe
• MR Conditional: Weigh risk/benefit (relative contraindication)
• MR Unsafe: Generally contraindicated (absolute contraindication)

Source

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