Table 3

Risk stratification of performing MRI in patients with MR Unlabelled CIEDs or MR Conditional CIEDs outside specified conditions

Risk categoryScenarioClinical riskLevel of evidence
LowestMR Conditional CIEDs* (meeting all conditions)MR safety tested by device manufacturer.25–27A
MR Conditional CIEDs with additional MR Conditional device implanted (eg, coronary stent)No clinical evidence of increased risk.A
LowerRecent implants (<6 weeks)No clinical evidence of increased risk.49C
Unmet condition due to presence of additional implanted deviceNo clinical evidence of increased risk.C
Temporary surgical epicardial pacing wires (with no external component)No clinical evidence of increased risk.66–69C
Unmet patient position exclusion zone, MR Conditional CIEDsNo clinical evidence of increased risk.78 79B
Scanning beyond SAR restrictions with MR Conditional CIEDs when required for diagnostic imagingNo clinical evidence signal of increased risk.75 76C
3 T MRI field strength, MR Conditional CIEDs labelled as MR Conditional at 1.5 T onlyNo clinical evidence of increased risk.80 81C
MR Unlabelled pin plug with MR Conditional generator and leadsNo clinical evidence of increased risk.C
‘Mismatched’ CIEDs with MR Conditional generators, MR Unlabelled leadsNo clinical evidence of increased risk.34C
IntermediateInactive, battery-depleted CIEDsPotential signal of increased risk from one case.34C
Generators implanted outside the pectoral regionHigher risk.C
MR Unlabelled generators, any lead MR labelling (non-pacing dependent)Risk of device failure.B
MR Unlabelled generators, any lead MR labelling (pacing dependent)Higher risk of asystole in the event of device failure.B
Abandoned leads (capped or not)Lead/Tissue heating in experimental studies, no reported clinical complications.49 57 59 60 63–65C
HigherStable abnormal lead parameterHigher risk, mitigated by investigating cause and appropriate device programming.C
CIED component advisory warningHigher risk depending on cause.C
Permanent epicardial leadsNo clinical evidence of increased risk.49 67C
Fractured leadsHigher risk.C
Battery at elective replacement intervalHigher risk.C
Temporary systems with externalised generatorNo clinical evidence of increased risk.49 71C
Pre-2000 market release generatorsIncreased risk of electrical reset.45B
AvoidPacing-dependent patients with ICDs devices where not possible to maintain asynchronous pacing (VOO/DOO)Unavoidable extremely high risk—do not scan.C
Scanning any active CIED without reprogramming prior to scan to minimise riskRisk highly possible—do not scan.C
  • Risk is represented as categories, but within each category the scenarios should be considered as a scale from low to progressively higher risk (top to bottom of the table - shaded from green to red respectively, with black shaded categories representing scenarios where MRI should be avoided). Overall risk is a combined consideration of the likelihood of an event and the clinical outcome if that event occurred. Scenarios considered higher risk either have a paucity of trial data describing clinical safety end points, or are based on expert consensus despite small series reporting safe MRI scanning. Level of evidence A=data derived from multiple randomised controlled trials, or meta-analyses; level of evidence B=data derived from a single randomised clinical trial or large non-randomised study; level of evidence C=consensus of expert opinion based on clinical experience or case series.

  • *Includes both permanent pacemakers. ICDs and implantable cardiac monitors.

  • CIED, cardiac implantable electronic device; ICD, implantable cardioverter-defibrillator; NA, not applicable; SAR, specific absorption rate.