Elizabeth Mary Tunnicliffe1,2, Martin John Graves1,3, Matthew D. Robson4
1Department of Medical Physics & Clinical Engineering, Addenbrooke's Hospital, Cambridge, United Kingdom; 2AVIC, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom; 3Department of Radiology, University of Cambridge, Cambridge, United Kingdom; 4OCMR, Department of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom
The noise covariance matrix of a phased array coil provides information about both the noise level in individual channels and the correlations between channels. It can therefore be useful in quality assurance procedures as these characteristics are liable to change in the case of coil failure. This work presents examples of noise covariance matrices of functioning and failing arrays and suggests quantitative limits, beyond which remedial action may be required.