Digital multiband receiver for magnetic resonance

A multichannel, digital receiver made of off-the-shelf components is presented. The direct-sampling and software-based direct-conversion constitutes a flexible receiver platform for multinuclear MR applications. The architecture allows increased level of flexibility in the functionality of the receiver, also beyond MR imaging and spectroscopy applications. The system is designed in a way that the parallel operation with a standard MRI scanner does not require either hardware changes or specially designed pulse sequences. By using proper anti-alias filtering at the RF front-end, the system described can be applied for signal detection up to 128 MHz, corresponding to 3 T proton MR. In comparison with a standard, clinical MRI receiver systems, the described receiver provides comparable signal-to-noise ratio but results in somewhat decreased data processing speed. The multichannel, multifrequency characteristics are exploited for magnetic field monitoring using 2H deuterium-based NMR probes in conjunction with non-Cartesian 1H proton signal detection. Furthermore, the wide bandwidth direct sampling scheme is demonstrated for simultaneous acquisition of multiple signals at distinct, nonoverlapping frequency bands.