Magnetic Field Efficiency of Transmission Coils and Antenna Arrays for 7T MRI of the Lumbar Spine

초록

7T Magnetic Resonance Imaging (MRI) offers higher resolution imaging than lower-field MRI but faces challenges in clinical adaptation, particularly for spine imaging. Two major issues are the limited transmission of the magnetic field into deep tissues due to shortened wavelength caused by tissue electrical properties at higher frequencies and safety concerns related to specific absorption rate (SAR), which restrict clinical approval. This study surveys the performance of commonly used 7T MRI magnetic field transmission elements. Their efficiency is evaluated based on their geometry and design, with the magnetic field intensity, uniformity, and maximum local SAR. A scoring function is proposed to quantify the array performance, assessing field intensity, uniformity, and SAR at selected regions of interest in the lumbar spine. Results indicate that loop coil arrays provide the best efficiency for 7T MRI spine imaging.

키워드