Free-breathing simultaneous , , and quantification in the myocardium.

Area of Science:

• Cardiovascular Magnetic Resonance Imaging
• Quantitative MRI
• Tissue Characterization

Background:

• Accurate myocardial tissue characterization requires simultaneous measurement of T1, T2, and T2* relaxation times.
• Conventional methods often necessitate multiple scans or breath-holding, limiting clinical applicability.
• Developing a single, free-breathing sequence for comprehensive assessment is crucial.

Purpose of the Study:

• To implement and validate the Saturation And T2-prepared Relaxometry with Navigator-gating (SATURN) technique.
• To enable simultaneous free-breathing quantification of T1, T2, and T2* in the myocardium.
• To achieve comprehensive myocardial tissue characterization in a single MRI scan.

Main Methods:

• The SATURN technique utilizes a multi-gradient-echo readout with saturation and T2 preparation pulses.
• Acquisition involves a series of images with varying saturation and T2 preparation times, and multiple echo times.
• Validation was performed using Bloch simulations, phantom experiments, and comparison with conventional single-parameter methods in volunteers and patients.

Main Results:

• The 5-parameter fit model used in SATURN was accurately validated by simulations and phantom experiments.
• In vivo parameter maps from SATURN were visually comparable to those from conventional methods.
• Quantitative measurements showed no significant differences between SATURN and single-parameter methods for T1, T2, and T2* values.

Conclusions:

• SATURN enables simultaneous, free-breathing quantification of T1, T2, and T2* in the myocardium.
• The technique provides co-registered parameter maps for comprehensive tissue characterization.
• SATURN achieves good agreement with conventional methods, offering a more efficient single-scan solution.