A SIMPLE NUMERICAL METHOD TO COMPUTE THE SIGNAL-TO-NOISE RATIO OF A MAGNETIC RESONANCE IMAGING SURFACE COIL

The quality of a magnetic resonance image can be reliably measured by the signal-to-noise ratio. This widely accepted parameter is a function of the magnetic field generated by the coil and the electric field produced by the sample to be imaged. A simple numerical method is proposed to calculate the coil signal-to-noise ratio of a circular shaped coil and a spherical phantom. The phantom is composed of two concentric sphere simulating a brain-skull model. The electromagnetic fields produced were then numerically computed by solving Maxwell's equations with the finite element method implemented in a commercial software tool. The electric and magnetic fields were used to numerically determine the signal-to-noise ratio using the quasi-static approach. The numerical results demonstrated that this simple method is able to calculate the signal-to-noise ratio of surface coils with simple coil geometries involving a simulated phantom.