Native myocardial T₁ mapping using inversion recovery T₁-weighted turbo field echo sequence

Area of Science:

• Cardiovascular Magnetic Resonance Imaging
• Quantitative MRI Techniques

Background:

• Myocardial T1 mapping is crucial for assessing tissue characteristics.
• The modified Look-Locker inversion recovery (MOLLI) sequence is widely used but has limitations.
• Accurate and reproducible T1 measurements are essential for clinical applications.

Purpose of the Study:

• To evaluate the inversion recovery T1-weighted turbo field echo (IR-T1TFE) sequence for myocardial T1 mapping.
• To compare the accuracy, precision, and reproducibility of IR-T1TFE with the MOLLI sequence.
• To validate IR-T1TFE as a reliable method for native myocardial T1 quantification.

Main Methods:

• Phantom studies were conducted using vials with known T1 values to compare IR-T1TFE, MOLLI, and inversion recovery spin-echo (IR-SE).
• In vivo studies involved 15 healthy subjects undergoing native myocardial T1 mapping with both MOLLI and IR-T1TFE sequences.
• Myocardium segmentation was performed to calculate whole-myocardium T1 values.

Main Results:

• IR-T1TFE demonstrated excellent accuracy across all T1 ranges in phantom studies.
• MOLLI showed lower accuracy than IR-T1TFE, significantly underestimating T1 values above 1000 ms.
• In vivo, mean myocardial T1 values were higher with IR-T1TFE (1484 ± 28 ms) compared to MOLLI (1306 ± 70 ms).
• Reproducibility within each sequence was not statistically significant.

Conclusions:

• The IR-T1TFE sequence is a valid and useful tool for myocardial T1 mapping.
• IR-T1TFE provides highly accurate and reproducible native myocardial T1 measurements.
• This sequence offers a reliable alternative for quantitative assessment of myocardial tissue.