Nexus: A versatile console for advanced low-field MRI

To develop a low-cost, high-performance, versatile, open-source console for low-field MRI applications that can integrate a multitude of different auxiliary sensors.

A new MR console was realized with four transmission and eight reception channels. The interface cards for signal transmission and reception are installed in PCI Express slots, allowing console integration in a commercial PC rack. Following standards developed by the MRI community, we implemented an open-source console software package with native Pulseq and ISMRM raw data support. It is implemented in Python to allow easy customization and provide the flexible use of a freely configurable number of transmit and receive channels. We benchmarked the system by comparing the imaging quality with a state-of-the-art reference system. Different examples of how auxiliary sensors, connected via additional channels, can improve imaging are demonstrated.

Using a three-dimensional turbo spin-echo sequence, image quality of proton density-weighted and T₂-weighted images in the brain of a healthy volunteer obtained by the proposed Nexus console matches closely to a commonly applied commercial system. The use of additional receive channels was demonstrated for system monitoring (radiofrequency pulses and gradient currents), electromagnetic interference detection, and temperature and B₀ field monitoring. Based on these measurements, system calibrations and electromagnetic interference-mitigation techniques were applied to improve image quality.

Our console offers high versatility in terms of data acquisition, is freely configurable, adheres to open-source data standards, and is easy to customize. It yields a similar image quality compared with a commercially available reference system yet is substantially lower cost and open source.