Benchmarking the performance of a low-cost Magnetic Resonance Control System at multiple sites in the open MaRCoS community

Abstract

Purpose: To describe the current properties and capabilities of an open-source hardware and software package that is being developed by many sites internationally with the aim of providing an inexpensive yet flexible platform for low-cost MRI. Methods: This paper describes three different setups from 50 to 360 mT in different settings, all of which used the MaRCoS console for acquiring data, and different types of software interfaces (custombuilt GUI or PulSeq overlay) to acquire the data. Results: Images are presented from both phantoms and in vivo from healthy volunteers to demonstrate the image quality that can be obtained from the MaRCoS hardware/software interfaced to different low-field magnets. Conclusions:The results presented here show that a number of different sequences commonly used in the clinic can be programmed into an open-source system relatively quickly and easily, and can produce good quality images even at this early stage of development. Both the hardware and software will continue to develop, and it is an aim of this paper to encourage other groups to join this international consortium.I. I M ARCOS (Magnetic Resonance Control System) is a low-cost, high-performance console developed to fulfill the requirements of a rapidly expanding low-field Magnetic Resonance Imaging (LF-MRI) community [1]- [3]. LF-MRI is developing as a customizable and affordable complement to standard high-field MRI (> 1 T), which is an expensive medical imaging modality in terms of purchase cost, maintenance, siting and training, and consequently is concentrated in large hospitals in the economically developed world [4]-[8]. In the last few years, LF-MRI has demonstrated its value for point-ofcare imaging [9]-[15], home healthcare [16], quantitative MRI

MaRCoS, an open-source electronic control system for low-field MRI

“…The FPGA part of the Zynq communicates with a dual-channel 16-bit analog-digital converter (ADC) and a dual-channel 14bit digital-analog converter (DAC), which together provide two independent channels for MRI 3 . The system is clocked from a 122.88 MHz crystal oscillator 4 , providing an analog baseband bandwidth of ∼ 50 MHz.…”

“…The GPA-FHDO and adapter PCB designs are fully open-source [27], and a set of PCBs can be manufactured and assembled for below $400. 3 ADC: Analog Devices LTC2185. DAC: Analog Devices AD9767 4 Abracon ABLNO-122.880MHz 5 Texas Instruments DAC80504 6 Analog Devices ADUM4150 7 The SPI bandwidth can be used to update the channels unevenly, e.g.…”

“…The phase and magnitude of control pulses, as well as their timing, is sufficiently stable for demanding MRI applications [3]. Although more thorough characterization is required, the MaRCoS hardware is sufficiently stable for imaging with a range of sequences including gradient echo, turbo spin echo or inversion recovery, with different sampling trajectories like Cartesian or radial [3].…”

“…The consoles provided by the major scanner manufacturers tend to be tailored to their specific setups [2], [3], but there exist also more generic concepts that are somewhat hardware-agnostic and could be used in a wide range of scanners. Although a number of relatively low cost consoles have been developed for MRI, e.g.…”

“…Among the projects opened to the community [2], [18]- [24], the Open-source Console for Real-time Acquistion (OCRA [21]) is notable for its flexibility, inexpensive off-the-shelf components, community focus, and real-time capabilities. The MAgnetic Resonance COntrol System (MaRCoS [3]) uses the same versatile hardware, however its software, firmware and FPGA firmware have been replaced to go beyond the limitations of OCRA.…”