MRI induced heating of pacemaker leads: effect of temperature probe positioning and pacemaker placement on lead tip heating and local SAR.

{
  "study_type": "engineering",
  "exposure": {
    "band": "RF",
    "source": "MRI",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "Lead tip temperature increase",
    "Local SAR at pacemaker lead tip",
    "Measurement error/underestimation due to temperature probe positioning",
    "Effect of pacemaker placement and lead geometry on heating/local SAR (phantom measurements)"
  ],
  "main_findings": "Experimental measurements indicated that temperature probe positioning affects measured lead-tip temperature and local SAR during MRI RF exposure. Transversal contact between the active portion of the fluoroptic probe and the lead tip produced the highest measured temperature and SAR; other configurations could underestimate temperature by ~11% and SAR by ~70%. Additional measurements in a human-shaped phantom in a real MRI system were performed to investigate effects of pacemaker placement and lead geometry on heating and local SAR.",
  "effect_direction": "harm",
  "limitations": [
    "Frequency, MRI sequence parameters, and exposure duration not reported in the abstract",
    "Quantitative heating/SAR values (absolute) not provided in the abstract",
    "Phantom-based measurements; human clinical outcomes not described",
    "Sample size and number of experimental repetitions not stated"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "MRI",
    "radiofrequency field",
    "pacemaker",
    "lead tip heating",
    "local SAR",
    "fluoroptic temperature probe",
    "probe positioning",
    "phantom"
  ],
  "suggested_hubs": [
    {
      "slug": "medical-imaging-mri",
      "weight": 0.95,
      "reason": "Study examines RF exposure during MRI and associated heating/local SAR around pacemaker leads."
    },
    {
      "slug": "implanted-medical-devices",
      "weight": 0.9,
      "reason": "Focus on pacemaker lead tip heating and effects of device placement/geometry."
    }
  ]
}