7 research outputs found
Benchmarking the performance of a low-cost Magnetic Resonance Control System at multiple sites in the open MaRCoS community
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 (custom-built 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.Comment: 9 pages, 10 figures, comments welcom
A 31-channel integrated âAC/DCâ B0 shim and radiofrequency receive array coil for improved 7T MRI
Purpose: To test an integrated "AC/DC" array approach at 7T, where B0 inhomogeneity poses an obstacle for functional imaging, diffusion-weighted MRI, MR spectroscopy, and other applications. Methods: A close-fitting 7T 31-channel (31-ch) brain array was constructed and tested using combined Rx and ÎB0 shim channels driven by a set of rapidly switchable current amplifiers. The coil was compared to a shape-matched 31-ch reference receive-only array for RF safety, signal-to-noise ratio (SNR), and inter-element noise correlation. We characterize the coil array's ability to provide global and dynamic (slice-optimized) shimming using ÎB0 field maps and echo planar imaging (EPI) acquisitions. Results: The SNR and average noise correlation were similar to the 31-ch reference array. Global and slice-optimized shimming provide 11% and 40% improvements respectively compared to baseline second-order spherical harmonic shimming. Birdcage transmit coil efficiency was similar for the reference and AC/DC array setups. Conclusion: Adding ÎB0 shim capability to a 31-ch 7T receive array can significantly boost 7T brain B0 homogeneity without sacrificing the array's rdiofrequency performance, potentially improving ultra-high field neuroimaging applications that are vulnerable to off-resonance effects