The geometrical noise amplification factor (g-factor) of an eight-channel receive-only coil array was studied for brain imaging at various field strengths. At 1.5, 3.0 and 7.0 Tesla, both experimental and simulation results were obtained and compared for verification purposes. Numerical simulations were further performed at 11.7, 14.0 and 21.0 Tesla. It was found that the most significant parallel imaging performance gain was achieved at an acceleration rate 4 and when the field strength is above 3.0 Tesla. However, the performance of parallel imaging plateaus above 11.7 Tesla plateaus due to highly correlated coil profiles.