Methodology for improved detection of low concentration metabolites in MRS: optimised combination of signals from multi-element coil arrays.
State of the art magnetic resonance imaging (MRI) scanners are generally equipped with multi-element receive coils; 16 or 32 channel coils are common. Their development has been predominant for parallel imaging to enable faster scanning. Less consideration has been given to localized magnetic resonance spectroscopy (MRS). Multinuclear studies, for example (31)P or (13)C MRS, are often conducted with a single element coil located over the region of interest. (1)H MRS studies have generally employed the same multi-element coils used for MRI, but little consideration has been given as to how the spectroscopic data from the different channels are combined. In many cases it is simply co-added with detrimental effect on the signal to noise ratio. In this study, we derive the optimum method for combining multi-coil data, namely weighting with the ratio of signal to the square of the noise. We show that provided that the noise is uncorrelated, this is the theoretical optimal combination. The method is demonstrated for in vivo proton MRS data acquired using a 32 channel receive coil at 7T in four different brain areas; left motor and right motor, occipital cortex and medial frontal cortex.
['Hall|Emma L|EL|', 'Stephenson|Mary C|MC|', 'Price|Darren|D|', 'Morris|Peter G|PG|']
D000465:Algorithms D002540:Cerebral Cortex D004867:Equipment Design D019544:Equipment Failure Analysis D006801:Humans D009682:Magnetic Resonance Spectroscopy D018377:Neurotransmitter Agents D015203:Reproducibility of Results D012680:Sensitivity and Specificity D059629:Signal-To-Noise Ratio D014159:Transducers D005680:gamma-Aminobutyric Acid
MRS MRI Multi-element receive coil SNR