Four-row MR-linac receive array with remote circuitry to preserve radiation transparency

Motivation: Linac-compatible coils have been restricted to one or two rows because of the desire to place radiation-opaque circuitry adjacent to the coils and outside the window through which the beam travels. Such layouts limit parallel imaging performance. Goal(s): We previously showed that a remote circuit strategy allows greater freedom in array layout but carries a loss penalty. Here, we explored its limits. Approach: We built a four-row array with remote circuits and compared it to two- and three-row arrays with similar coverage. Results: The four-row array provided similar central SNR and significant g-factor advantages compared to the two- and three-row arrays Impact: High performance, multi-directional parallel imaging enabled by remote circuits in a four-row array can potentially support MR-linac applications that require rapid imaging and high SNR.