Improved assessment of radiofrequency electromagnetic field power deposition near orthopaedic device using a bone-inclusive ASTM phantom under 1.5T and 3T MRI.
Research
RF Safe Research Library
Jan 1, 2024
This engineering/simulation study proposes a bone-inclusive ASTM phantom to improve assessment of RF power deposition near orthopaedic implants during 1.5 T and 3 T MRI. Using numerical simulations across multiple implant families, the authors report better correlation of peak 1 g SAR near implants with anatomically…
The effects of RF coils and SAR supervision strategies for clinically applicable nonselective parallel-transmit pulses at 7 T.
Research
RF Safe Research Library
Jan 1, 2023
This engineering study evaluated how different 7T parallel-transmit head coils and SAR supervision strategies affect nonselective pTx pulse design for a 3D-MPRAGE sequence. It reports that FOCUS pulses were more robust than universal pulses when applied across different coils, and that FOCUS inversion pulses…
Effects of Anatomical Differences on Electromagnetic Fields, SAR, and Temperature Change.
Research
RF Safe Research Library
Jan 1, 2016
This engineering study evaluates how anatomical/geometric differences affect MRI RF safety metrics. Simulations and a bovine-phantom experiment found that similar transmit B-field patterns can coincide with notably different peak SAR and temperature rise. The authors highlight challenges in using…
Measurement of creatine kinase reaction rate in human brain using magnetization transfer image-selected in vivo spectroscopy (MT-ISIS) and a volume ³¹P/¹H radiofrequency coil in a clinical 3-T MRI system.
Research
RF Safe Research Library
Jan 1, 2011
This paper describes a new magnetization transfer 31P MRS approach (MT-ISIS) for measuring the creatine kinase forward reaction rate in the human brain using a volume 31P/1H RF coil on a clinical 3-T MRI system. The method aims to reduce acquisition time (30 min), avoid scalp muscle contamination, improve RF…
[Conclusion: probable and possible futures. MRI with ultra high magnetic field].
Research
RF Safe Research Library
Jan 1, 2009
This narrative piece states that MR neuroimaging does not interfere with brain function and is safe for use in patients and healthy volunteers. It argues that ultra-high-field MRI could substantially improve spatiotemporal resolution, potentially enabling study of brain function at finer scales. It also describes the…
Minimal-SAR RF pulse optimization for parallel transmission in MRI.
Research
RF Safe Research Library
Jan 1, 2008
This engineering study presents an optimization framework to design RF pulses for parallel transmission MRI with the goal of minimizing SAR. Using computer simulations of a 4-channel system, the authors report significant SAR reduction while maintaining excitation pattern quality and without increasing pulse…
Development of a patch antenna array RF coil for ultra-high field MRI.
Research
RF Safe Research Library
Jan 1, 2007
This engineering study describes development of a patch antenna array coil (PAAC) intended to address short RF wavelength challenges in ultra-high-field (≥7T) MRI. A prototype PAAC for 7T proton imaging was used to image a monkey brain. The authors report that the imaging demonstrated the coil's utility for…