Any-nucleus distributed active programmable transmit coil

Area of Science:

• Medical Imaging
• Nuclear Magnetic Resonance (NMR)
• Biophysics

Background:

• Most current Magnetic Resonance Imaging (MRI) relies on a single nucleus, hydrogen-1 (¹H).
• Numerous biologically relevant nuclei exist, offering potential for advanced research.
• Existing MRI technology is limited in its ability to image diverse nuclei.

Purpose of the Study:

• To develop a single transmit coil capable of exciting arbitrary nuclei for human-scale MRI.
• To overcome the limitations of current MRI technology in multi-nuclear imaging.
• To facilitate the imaging of biologically relevant nuclei beyond ¹H.

Main Methods:

• Introduction of the Any-nucleus Distributed Active Programmable Transmit Coil (ADAPT Coil).
• Integration of fast switches for operation at any relevant frequency.
• Direct conversion of direct current (DC) power to radiofrequency (RF) magnetic fields, controlled digitally.
• Segmentation of the coil to mitigate semiconductor switch imperfections.

Main Results:

• Circuit simulations confirmed the ADAPT Coil's effectiveness.
• A 9 cm diameter surface ADAPT Coil was successfully implemented.
• Phantom images of ¹H, ²³Na, ²H, and ¹³C were acquired.
• Ex vivo images of ¹H and ²³Na were obtained.
• Real-time reprogramming of nuclei excitation was achieved by altering digital control signals.

Conclusions:

• The ADAPT Coil offers a cost-effective, scalable, and efficient method for exciting arbitrary nuclei in MRI.
• This technology enables streamlined multi-nuclear MRI workflows.
• It opens avenues for studying dozens of biologically relevant nuclei, advancing medical research.