This work presents an open-source, optimized solenoid head coil tailored for the 50 mT open-source scanner (OSII ONE v2.1), set the basis for a fully reliable and reproducible component for the open-source OSII ONE MRI scanner.
Abstract
Low-field magnetic resonance imaging (MRI) provides an accessible, portable, and low-cost alternative to high-field scanners, expanding diagnostic imaging to point-of-care settings. However, widespread adoption is fundamentally hindered by a severely reduced signal-to-noise ratio (SNR). At low frequencies, radiofrequency (RF) coil conductor losses - rather than tissue sample losses - predominantly govern the system's total noise, making meticulous RF coil optimization critical to recovering image quality. This work presents an open-source, optimized solenoid head coil tailored for the 50 mT open-source scanner (OSII ONE v2.1). The paper validates production reproducibility across three independent international institutions and introduce an open-source connector with integrated digital circuitry for coil identification and DC or logic signals. Comprehensive benchtop measurements, Electromagnetic Interference (EMI) coupling analysis, Specific Absorption Rate (SAR) safety simulations, and phantom and human volunteer imaging confirm the design's efficacy, safety, and reproducibility. The results of the paper, when combined with the material provided in the open-source dedicated repositories, set the basis for a fully reliable and reproducible component for the open-source OSII ONE MRI scanner. In addition, the same optimization strategy and design material can be exploited for designing other RF coils for imaging of other body parts.
This review elaborates on the inductive coupling mechanism of ICWCs, the derivation of the SNR formula, potential causes of g-factor reduction, and recommendations for fabrication methods, providing a reference for the innovation of MRI RF coil technology and the clinical translation of ICWCs.
An open-source reference system for portable low-field MRI designed to support replication, reproducibility, benchmarking, and quantitative comparison is presented, aiming to support cross-site comparability, reproducible research, and collaborative development of future portable low-field MRI technologies.
D. Schote, H. Herthum, Umberto Zanovello et al.· 0 citations
The recent developments in ultra-low-field brain MRI are reviewed, which enable imaging in open environments and demonstrate initial clinical applicability in point-of-care settings, and future developments are envisioned to address the current limitations of image quality and contrast in ultra-low-field brain MRI systems.
Ed X. Wu, Yujiao Zhao, Yilong Liu et al.· Stroke· 1 citation
By providing higher temporal resolution motion tracking than FatNav, EMIC achieved superior PMC performance in 2D PC-MRI and significantly improved image quality.
Zhanbin Dong, Tuo Yu, Bingbing Zhao et al.· IEEE transactions on bio-med...· 0 citations
Magnetic resonance imaging (MRI) scanning remains largely restricted to specific modalities, typically involving low radiofrequency (RF) power levels and stringent protocols for patients with deep brain stimulation (DBS) implants, due to safety concerns related to RF-induced heating of the implants. A 6-channel dual-role head coil array capable of modulating the electric-field (E-field) distribution was designed and evaluated using electromagnetic (EM) simulations. By optimizing the resonant frequency of each coil element during RF transmission, the transmit field was reshaped, leading to a significant reduction in RF-induced heating near the DBS lead tip. The proposed method was validated across two scenarios of increasing complexity: 1) a simple straight conductive wire for concept validation and 2) four realistic DBS leads representing complex real-world scenarios. The coil settings can be optimized either to suppress the E-field at a specific location, such as the DBS lead tip, or to suppress the peak specific absorption rate (SAR) across the entire human head. For location-specific E-field suppression, the simplified predefined-state control scheme and the fine-tuning genetic algorithm (GA)-based framework were implemented, achieving E-field reductions of 45.9% and 68.3%, respectively. For whole-head peak SAR suppression, the annealed Log-Sum-Exp (LSE)–Adaptive Moment Estimation (Adam) framework (LSE–Adam) was implemented, achieving an average 1 g SAR reduction of 72.09% across four realistic DBS lead models. The dual-role coil demonstrated a high degree of flexibility in controlling the transmit field and reducing RF-induced heating at DBS implants, offering a novel approach to mitigate RF-induced heating of the implants in MRI.
Zhonghao Zhang, Ming Lu, Zhengyi Lu et al.· IEEE Access· 0 citations
It is demonstrated that the use of an endorectal monopole antenna substantially increases the SNR of 7 ‐ T MRI at the cervical anatomy and may be employed to obtain metabolic information using MRS and to enhance spatial resolutions to assess tumor invasion.
I. M. L. van Kalleveen, J. Hoogendam, A. J. E. Raaijmakers et al.· 0 citations
