A three-dimensional free-breathing sequence for simultaneous myocardial T₁ and T₂ mapping

Area of Science:

• Cardiovascular Magnetic Resonance Imaging
• Biomedical Engineering
• Medical Physics

Background:

• Accurate measurement of native myocardial T1 and T2 is essential for diagnosing and monitoring various cardiac conditions.
• Existing techniques may be limited by scan time, breath-holding requirements, or simultaneous measurement capabilities.

Purpose of the Study:

• To develop, test, and validate a novel 3D free-breathing magnetic resonance imaging (MRI) technique.
• To enable simultaneous measurement of native myocardial T1 and T2 values.
• To assess the accuracy and precision of the proposed technique in phantoms and human subjects.

Main Methods:

• Acquisition of five fat-suppressed, electrocardiogram-triggered, respiratory navigator-gated spoiled gradient echo volumes in an interleaved manner.
• Utilizing a combination of nonselective saturation and T2 preparation for four volumes, and fully recovered longitudinal magnetization for one volume.
• Validation through numerical simulations, phantom experiments, and in vivo MRI in 15 healthy subjects.

Main Results:

• The developed 3D technique allows for whole-heart T1 and T2 mapping with a voxel size of 1.5 x 1.5 x 16 mm3.
• In vivo scans were acquired in approximately 8 minutes without parallel imaging.
• Measured T1 and T2 values demonstrated homogeneity in the left ventricle myocardium and were insensitive to heart rate.

Conclusions:

• The proposed 3D free-breathing technique successfully enables simultaneous measurement of whole-heart native myocardial T1 and T2.
• The method achieves preserved accuracy and precision in a single, efficient scan.
• This technique holds promise for improved cardiac MRI assessment.