Effect of the Modified Look-Locker Inversion Recovery Sampling Scheme on Accuracy and Heart Rate Variability in...

Area of Science:

• Medical Imaging
• Cardiovascular MRI
• Quantitative MRI

Background:

• T1 relaxation time is crucial for cardiovascular magnetic resonance imaging (CMR) assessments.
• Modified Look-Locker inversion recovery (MOLLI) is a common technique for T1 mapping.
• Understanding the impact of heart rate variability (HRV) on MOLLI accuracy is essential for clinical translation.

Purpose of the Study:

• To evaluate the accuracy and HRV-induced variability of different MOLLI sampling schemes.
• To identify the optimal MOLLI sequence for robust T1 quantification in CMR.

Main Methods:

• Comparison of five MOLLI sampling schemes (5(3)3, 5s(3s)3s, 4(1)3(1)2, 4s(1s)3s(1s)2s, 3(3)3(3)5).
• Utilized a phantom experiment with a simulated electrocardiogram signal.
• Assessed accuracy against reference T1 values and variability across different heart rates.

Main Results:

• The 5(3)3 and 5s(3s)3s schemes showed high accuracy (R² > 0.95) for native and contrast-enhanced T1 values.
• The 5(3)3 scheme exhibited minimal T1 measurement variation due to HRV (<6% error).
• This scheme maintained accuracy irrespective of the T1 value or heart rate.

Conclusions:

• The 5(3)3 MOLLI sequence offers superior accuracy and robustness against HRV for T1 mapping.
• This sequence is suitable for quantitative CMR across a wide range of T1 values.
• The 5(3)3 scheme enhances the reliability of cardiovascular MRI diagnostics.