Rapid combined T1 and T2 mapping using gradient recalled acquisition in the steady state

Area of Science:

• Magnetic Resonance Imaging
• Biomedical Engineering
• Medical Physics

Background:

• Accurate T1 and T2 relaxation time mapping is crucial for quantitative MRI.
• Existing methods often suffer from long acquisition times or lower accuracy.
• There is a need for efficient and high-resolution relaxation time mapping techniques.

Purpose of the Study:

• To present a novel, fully 3D, high-resolution method for simultaneous T1 and T2 mapping.
• To evaluate the accuracy and efficiency of the proposed method compared to conventional techniques.
• To demonstrate the potential for real-time clinical application of whole-brain T1 and T2 mapping.

Main Methods:

• Developed a steady-state imaging technique utilizing spoiled gradient recalled echo (SPGR) and refocused steady-state free precession (SSFP) sequences.
• T1 information derived from optimized flip angle SPGR images.
• T2 information derived by combining T1-weighted SPGR data with SSFP images.

Main Results:

• Achieved approximately 7% error for T1 (300-2000 ms) and T2 (30-150 ms) mapping in phantom and in vivo studies.
• Demonstrated superior efficiency, being three times more efficient than multipoint inversion recovery (IR) and multiecho spin-echo (SE) methods.
• Enabled whole-brain T1 and T2 mapping with 1 mm³ isotropic voxels in under 15 minutes, including post-processing.

Conclusions:

• The novel method provides accurate and highly efficient 3D T1 and T2 mapping.
• This technique significantly reduces acquisition time, facilitating real-time clinical applications.
• The presented approach represents a substantial advancement in quantitative MRI for diagnostics and research.