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.