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Numerical simulation in magnetic resonance imaging radiofrequency dosimetry
Christiana Subaar1, Emmanuel Gyan2, Kwadwo A Dompreh3
1Department of Physics, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Biomedical Physics & Engineering Express
|August 2, 2024
Summary
Radiofrequency electromagnetic fields (RF EMFs) used in Magnetic Resonance Imaging (MRI) scans may cause heat buildup in the brain. This study used computational methods to estimate temperature increases during MRI, finding that longer scan times correlate with higher body temperatures.
Area of Science:
- Biomedical Engineering
- Medical Imaging Physics
Background:
- Magnetic Resonance Imaging (MRI) utilizes radiofrequency electromagnetic fields (RF EMFs) for imaging.
- The biological effects and potential health hazards of RF EMF exposure during MRI remain insufficiently understood.
- In-vivo temperature monitoring during MRI is invasive, necessitating computational approaches.
Purpose of the Study:
- To estimate the absorbed power and resulting temperature distributions in the brain during MRI scans.
- To analyze potential thermal effects in patients undergoing brain MRI across various field strengths.
Main Methods:
- Modified a three-dimensional Penne's bio-heat equation for computational analysis.
- Simulated temperature distributions and thermal effects within the brain for MRI scans from 0.3 T to 1.5 T.
- Calculated instantaneous and cumulative temperature increases over time.
Main Results:
- Simulations indicated temperature increases in brain tissue during MRI scans.
- Measured temperature rises were 0.2 °C at 20.62 s and 0.4 °C at 30.92 s.
- Highest recorded temperatures reached 0.4 °C at 1.03 min and 0.6 °C at 2.06 min, showing heat buildup.
Conclusions:
- MRI RF EMF exposure leads to heat buildup and temperature increases in patients.
- Preventing temperature increases during MRI is challenging.
- Extended MRI imaging duration is associated with elevated body temperatures.
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