Elizabeth M. Tunnicliffe1, Martin J. Graves1
1Department of Medical Physics and Clinical Engineering, Cambridge University Hospitals, Cambridge, CB2 0QQ, United Kingdom
This phantom study compares six signal-to-noise ratio (SNR) measurement methods in two eight-channel head arrays. While the methods are equivalent for well de-coupled elements, this is not the case once noise correlations exist, which can indicate that an array is failing. In the absence of longitudinal SNR data, a comparison between the background region standard deviation SNR method and the noise power SNR method can provide evidence of array failure. In this situation the noise power method provides the most accurate estimate of the underlying SNR in a single image acquisition.