Artifact-suppressed optimal three-dimensional T₁ - and T₂ *-weighted dual-echo imaging

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Physics
• Biomedical Engineering

Background:

• Conventional MRI sequences often face challenges in simultaneously achieving optimal contrast for different tissue properties.
• Simultaneous T1- and T2*-weighted imaging is desirable for comprehensive diagnostic information but technically demanding.

Purpose of the Study:

• To develop and validate an artifact-suppressed, optimal three-dimensional (3D) T1- and T2*-weighted dual-echo imaging sequence.
• To enable simultaneous high-resolution T1- and T2*-weighted imaging in a single scan.

Main Methods:

• Optimization of flip angles for 3D T1- and T2*-weighted imaging using in vivo experiments and simulations.
• Implementation of a dual-echo sequence with echo-specific k-space reordering to achieve optimal contrast for both T1 and T2*.
• Development of two artifact suppression strategies: smooth transition regions and discarding k-space regions with abrupt flip angle changes.

Main Results:

• Experimental and simulation results confirmed optimal flip angles differ for T1 and T2* contrast.
• The optimized dual-echo sequence achieved simultaneous optimal T1 and T2* contrast.
• Proposed artifact suppression strategies effectively mitigated ringing artifacts caused by flip angle variations.

Conclusions:

• The developed 3D dual-echo sequence provides simultaneous optimal T1 and T2* contrast without artifacts.
• This technique holds potential for routine clinical application in simultaneous high-resolution T1- and T2*-weighted MRI.