Free-breathing three-dimensional simultaneous myocardial T₁ and T₂ mapping based on multi-parametric...

Area of Science:

• Cardiovascular Magnetic Resonance Imaging
• Quantitative Myocardial Tissue Characterization
• Advanced Imaging Techniques

Background:

• Current T1 and T2 mapping for cardiomyopathies often uses 2D breath-hold sequences.
• Three-dimensional (3D) techniques are limited by long scan times, hindering clinical adoption.
• Accurate assessment of myocardial tissue abnormalities requires advanced parametric mapping.

Purpose of the Study:

• To develop and validate a time-efficient 3D free-breathing simultaneous T1 and T2 mapping sequence.
• To introduce the multi-parametric SAturation-recovery and Variable-flip-Angle (mSAVA) technique.
• To overcome limitations of current 2D mapping methods in terms of scan duration.

Main Methods:

• Developed and validated the mSAVA sequence using simulations, phantoms, and in-vivo 3T MRI.
• Acquired four volumes for simultaneous whole-heart T1 and T2 mapping.
• Compared mSAVA T1/T2 values with MOLLI/GraSE and evaluated clinical performance against LGE in 11 healthy subjects and 11 patients.

Main Results:

• mSAVA demonstrated strong correlation with reference sequences in phantoms (R² = 0.98-0.99).
• Achieved in-vivo imaging resolution of 1.5 × 1.5 × 8 mm³ with free-breathing acquisition.
• In patients, mSAVA T1/T2 maps showed consistent findings with LGE, with T2 standard deviation lower than GraSE.

Conclusions:

• mSAVA is a fast, 3D technique for simultaneous T1 and T2 mapping.
• The method is promising for clinical whole-heart assessment of cardiomyopathies.
• mSAVA offers a time-efficient alternative to current 2D mapping sequences.