Perry Karmarkar1, William A. Edelstein1, Paul A.
1Suite B307, 1101 E 33rd Street,
SurgiVision Inc, Baltimore, MD, United States
about RF heating of implanted devices precludes MRI for many patients who
could otherwise benefit. Implanted leads are insulated and vary in length,
depending on function and patient size.
We investigated experimentally and theoretically the local specific
absorption rate (SAR) and heating of leads as a function of sample size, lead
length, and insulation thickness in gel phantoms exposed to 4W/kg at
1.5T. Heating and SAR are maximum at
the bare electrode, increasing with lead insulation thickness and sample
size. SAR is highly nonuniform so
sensor sampling volume is critical for matching local theoretical SAR with
measured temperature changes.