meta-DENSE complex acquisition for reduced intravoxel dephasing.

Area of Science:

• Biomedical Imaging
• Cardiovascular Magnetic Resonance
• Quantitative MRI

Background:

• Displacement Encoding with Stimulated Echoes (DENSE) is a quantitative MRI technique for measuring myocardial strain.
• Intravoxel dephasing can lead to signal loss in DENSE imaging, affecting strain map quality.
• Existing methods like meta-DENSE aim to suppress unwanted signals but may not fully address dephasing.

Purpose of the Study:

• To introduce and evaluate a novel RF phase cycling scheme for DENSE MRI.
• To reduce intravoxel dephasing signal loss in DENSE imaging.
• To improve the quality of DENSE-derived myocardial strain maps.

Main Methods:

• Implementation of a specific RF phase cycling strategy to suppress the STEAM anti-echo.
• Combination of the RF phase cycling with the meta-DENSE readout.
• Acquisition of phantom and human cardiac images using the enhanced DENSE sequence.
• Assessment of image quality and reduction in intravoxel dephasing.

Main Results:

• The proposed RF phase cycling effectively suppresses the STEAM anti-echo.
• The combined technique significantly reduces intravoxel dephasing signal loss compared to prior methods.
• Higher quality DENSE myocardial strain maps were achieved.
• Acquisition at lower encoding gradient strengths was possible, improving spatial resolution.

Conclusions:

• The described RF phase cycling combined with meta-DENSE offers superior DENSE imaging performance.
• This method provides enhanced myocardial strain quantification with reduced artifacts.
• The technique holds promise for improved clinical assessment of cardiac mechanics.