Ramping down a clinical 3 T scanner: a journey into MRI and MRS at 0.75 T

Area of Science:

• Medical Imaging
• Physics

Background:

• Lower-field magnetic resonance imaging (MRI) offers a cost-effective alternative to high-field MRI.
• Limited availability and high cost of dedicated lower-field MRI systems hinder research.
• Advances in hardware and software have revitalized interest in lower-field MRI.

Purpose of the Study:

• To present a low-cost, temporary solution for lower-field MRI research.
• To demonstrate the feasibility of modifying a clinical MRI system for lower field strengths.
• To enable advanced MRI techniques at reduced field strengths.

Main Methods:

• A clinical 3 Tesla (T) MRI system was ramped down to 0.75 T.
• Proton signals were acquired using repurposed 13C transmit/receive hardware.
• Software and hardware modifications for the multi-nuclei spectrometer interface were implemented.

Main Results:

• System characterization was performed at the reduced field strength.
• In vivo cardiac cine imaging and abdominal water/fat separation were achieved.
• Water/fat-separated MR Fingerprinting and point-resolved spectroscopy were successfully demonstrated.
• Unique comparisons of gradient fidelity at different field strengths were enabled.

Conclusions:

• Ramping down existing MRI systems is a viable option for lower-field research.
• This method provides a cost-effective alternative to acquiring new lower-field MRI systems.
• The approach serves as a platform for testing custom multi-nuclei transmit/receive coils.