Simulation on Newly Designed Radio Frequency Pick-Up Archimedean Spiral Coil for Magnetic Resonance Imaging

摘要

The radio frequency (RF) coils pick up the radio frequency waves which being radiated inside the human body for MRI (Magnetic Resonance Imaging) study. In the present study, a spiral coil for a clinical MR scanner for whole body has been designed and fabricated. The number of turns for the spiral coil was determined by the computer simulation. The designed coil has following spiral dimension: diameter of 80 mm, width of spiral line of 1.0 mm, pitch of 2.0 mm, turns of twelve in the flat plane. The resonance frequency was adjusted to 64 MHz, which was corresponded to a 1.5 Teslas MRI system. Quality factor (Q) of the spiral RF coil was measured in comparison with a single-loop RF coil. The results show that Q of the spiral RF coil is twenty-four percents higher than thatrnof the single loop coil in the experiment with a phantom. Comparison of signal-to-noise ratio shows that the spiral RF coil has better sensitivity. The present study shows that the Archimedean coil is effective for MRI, and that simulation is effective to evaluate inductance at each frequency without experiments in phantom by manufacturing various coils.