Long-T₂ -suppressed zero echo time imaging with weighted echo subtraction and gradient error correction

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Biomedical Engineering
• Radiology

Background:

• Direct MRI of short-T2 tissues is challenging due to signal decay.
• Existing methods often struggle with selectivity and speed.
• Musculoskeletal (MSK) imaging requires high-resolution visualization of tissues like bone and ligaments.

Purpose of the Study:

• To develop and validate a selective MRI technique for short-T2 tissues.
• To utilize zero echo time (ZTE) imaging combined with weighted echo subtraction (WSUB).
• To achieve direct, high-resolution imaging of specific tissues in MSK applications.

Main Methods:

• Acquired ZTE and gradient echo (GRE) signals using radial imaging at 7T.
• Employed weighted subtraction of ZTE and GRE images for long-T2 suppression.
• Implemented gradient history matching and trajectory measurement to correct for gradient imperfections.

Main Results:

• Successfully addressed gradient imperfections through trajectory analysis and phantom imaging.
• Demonstrated high-resolution 3D imaging of bone, tendons, and ligaments in vivo.
• Achieved excellent selectivity for short-T2 tissues with high signal-to-noise ratio (SNR).

Conclusions:

• Weighted subtraction of ZTE and GRE data provides robust long-T2 suppression and efficient k-space coverage.
• The developed approach enables high-resolution imaging selective to short-T2 tissues.
• This technique holds significant promise for MSK and neuroimaging applications.