A new magnetic resonance imaging $($MRI$)$ method is developed to determine the active and resting state of the brain. In a controlled experiment, when the brain is under rest, the amplitudes of all pixels from the brain image span over $10-30$ dB with a spatial average of $20$ dB$,$ and when the brain is active, the amplitudes of all pixels from the brain image span over $20-40$ dB with a spatial average of $30$ dB$.$ What is the contrast to noise ratio? With an unknown state of the brain, is it possible to tell whether it is resting state or active state based on the image?