Abstract
A recently developed compact 3 T (C3T) MRI scanner with high performance gradients [1, 2] has a dedicated radiofrequency (RF) transmit coil that exposes only the head, neck and a small portion of the upper body region during head-first scanning. Due to the unique coil geometry and patient positioning, the established SAR model used for a conventional whole-body scanner cannot be directly translated to the C3T. Here a specific absorption rate (SAR) estimation and validation framework was developed and used to implement a dedicated and accurate SAR prediction model for the C3T. Two different SAR prediction models for the C3T were defined and evaluated: one based on an anatomically derived exposed mass, and one using a fixed anatomical position located caudally to the RF coil to determine the exposed mass. After coil modeling and virtual human body simulation, the designed SAR prediction model was implemented on the C3T and verified with calorimetry and in vivo scan power monitoring. The fixed-demarcation exposed mass model was selected as appropriate exposed mass region to accurately estimate the SAR deposition in the patient on the C3T.
Original language | English (US) |
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Pages (from-to) | 168-176 |
Number of pages | 9 |
Journal | Magnetic Resonance Imaging |
Volume | 85 |
DOIs | |
State | Published - Jan 2022 |
Keywords
- Compact radiofrequency coil
- Magnetic resonance imaging
- Simulation
- Specific absorption rate
- Validation
ASJC Scopus subject areas
- Biophysics
- Biomedical Engineering
- Radiology Nuclear Medicine and imaging