Opportunities in Interventional and Diagnostic Imaging by Using High-Performance Low-Field-Strength MRI

Area of Science:

• Medical Imaging
• Magnetic Resonance Imaging (MRI)
• Cardiovascular Interventions

Background:

• Commercial low-field-strength MRI systems typically lack advanced hardware, limiting their use in demanding imaging techniques.
• A novel MRI system was developed integrating low field strength (0.55 T) with high-performance imaging capabilities.
• This innovation addresses the limitations of traditional low-field MRI for complex clinical applications.

Purpose of the Study:

• To evaluate the clinical utility of a high-performance low-field-strength (0.55 T) MRI system.
• Specific applications assessed include MRI-guided cardiovascular catheterizations using metallic devices, diagnostic imaging in high-susceptibility regions, and efficient imaging acquisition strategies.
• The study aimed to demonstrate the system's advantages over conventional MRI technologies.

Main Methods:

• A standard 1.5-T MRI system was modified to operate at 0.55 T, retaining high-performance hardware, shielded gradients, and advanced imaging techniques.
• MRI examinations were conducted between January 2018 and April 2019.
• Measurements included T1, T2, and T2* relaxation times, contrast agent relaxivity, and evaluation of clinical applications.

Main Results:

• Eighty-three 0.55-T MRI examinations were performed, showing shorter T1 (32%), longer T2 (26%), and longer T2* (40%) compared to 1.5 T.
• Metallic interventional devices (n=9) were safe (<1°C heating), enabling MRI-guided right heart catheterization in seven participants using metallic guidewires.
• Reduced image distortion in high-susceptibility regions (lungs, sinuses, intestines), enhanced lung signal with oxygen inhalation (19% vs 7.6%), and improved signal-to-noise ratio with spiral acquisitions were observed.

Conclusions:

• The high-performance low-field-strength (0.55 T) MRI system demonstrates significant advantages for specific clinical applications.
• Key benefits include safe MRI-guided interventions with metallic devices, superior imaging in high-susceptibility areas, and efficient image acquisition.
• This technology represents a promising advancement for specialized MRI procedures.