Selective suppression of artifact-generating echoes in cine DENSE using through-plane dephasing

Area of Science:

• Medical Imaging
• Biophysics
• Magnetic Resonance Imaging

Background:

• Displacement-encoded imaging with stimulated echoes (DENSE) MRI encodes tissue displacement in phase.
• Artifact-generating echoes (complex conjugate, T1 relaxation) in DENSE MRI can cause displacement measurement errors.
• Ideal artifact suppression should be independent of imaging parameters and not require extra acquisitions.

Purpose of the Study:

• To develop and evaluate a method for suppressing artifact echoes in DENSE MRI.
• To improve the accuracy of displacement measurements in DENSE imaging.
• To achieve artifact suppression without compromising signal or requiring additional complex sequences.

Main Methods:

• Utilized through-plane gradients to selectively dephase artifact-generating echoes in DENSE MRI.
• Modified a cine DENSE sequence incorporating dephasing gradients and complementary spatial modulation of magnetization (CSPAMM).
• Compared artifact suppression efficacy of dephasing alone, CSPAMM alone, and a combination of both techniques.

Main Results:

• Single-acquisition cine DENSE with dephasing alone achieved artifact suppression comparable to two-acquisition CSPAMM.
• Combining dephasing with CSPAMM (two acquisitions) yielded superior artifact suppression compared to either method individually.
• The proposed dephasing technique minimized signal loss of the primary stimulated echo.

Conclusions:

• Through-plane gradients offer an effective method for artifact suppression in DENSE MRI.
• Combining dephasing gradients with CSPAMM provides enhanced artifact reduction for accurate displacement quantification.
• This approach has the potential to improve the reliability of DENSE MRI in various applications.