MR Imaging Using Localized Oscillating Magnetic Fields

MRI is a cornerstone of modern diagnostics, offering detailed insights into soft tissue structures and dynamic processes. Despite advances like parallel imaging, which utilizes multiple RF receiver coils to accelerate acquisition, traditional MRI techniques are still limited by long scan times, especially for moving or dynamic samples. Existing methods, such as static magnetic field gradients and techniques like PatLoc or FRONSAC, provide partial solutions but lack the flexibility and speed needed for certain applications. To address these limitations, a new approach introduces localized, time-varying magnetic fields that enhance spatial encoding. This innovation builds on established parallel imaging principles, offering a scalable solution to further reduce acquisition times while maintaining high image quality.

This innovative imaging method accelerates MRI acquisition by incorporating localized, time-varying magnetic fields into the imaging process (Fig. 1). Small current loops, arranged around the imaging object, generate dynamic magnetic fields with independently adjustable frequencies and phases. These oscillating fields modify the local Larmor frequency of the magnetization, creating spatially unique modulations during signal acquisition.
Each coil in the system operates independently, enabling the generation of tailored field patterns that enhance spatial encoding. By leveraging advanced reconstruction algorithms, the spatial origin of the acquired signals can be accurately identified, allowing for significant reductions in the number of required measurements.
This method is designed to integrate seamlessly with existing parallel imaging techniques, combining their strengths with the additional spatial information provided by the localized oscillations. The system is scalable for applications requiring higher acceleration, offering flexibility and efficiency across various imaging scenarios.  

• Reduced Acquisition Time: Speeds up imaging by 2 to 4 times compared to conventional methods (Scheffler, et al., 2019).
• Enhanced Flexibility: Supports dynamic imaging scenarios, overcoming motion-related challenges.
• Improved Image Quality: Increases the signal-to-noise ratio (SNR) while maintaining spatial resolution.
• Scalability: Adapts to various imaging applications, including 2D and 3D modalities.
• Ease of Integration: Compatible with existing MRI hardware and parallel imaging systems.

• Medical Imaging: Rapid scanning for dynamic processes like cardiac motion or fetal imaging.
• Neuroscience: High-speed brain imaging for functional MRI (fMRI) studies.
• Pediatric and Emergency Care: Reduces scan time for patients unable to remain still.
• Industrial Use: Non-destructive testing for materials or devices.
• Portable MRI Systems: Ideal for low-resource settings where quick scans are crucial.

PCT (WO2020007794A1; 01.07.2019), active in EP, CN

K. Scheffler, et al., "Spread-spectrum magnetic resonance imaging" Magn Reson Med. 2019, 877–885 (2019)