Multiple-echo diffusion tensor acquisition technique (MEDITATE) on a 3T clinical scanner.

Area of Science:

• Magnetic Resonance Imaging
• Biomedical Engineering
• Diffusion Tensor Imaging

Background:

• Diffusion Tensor Imaging (DTI) provides valuable information about tissue microstructure.
• Standard DTI acquisition can be time-consuming, limiting its clinical utility.
• Developing faster DTI methods is crucial for dynamic and in-vivo applications.

Purpose of the Study:

• To describe the concepts and implementation of the Multiple-Echo Diffusion Tensor Acquisition Technique (MEDITATE) on a clinical MRI scanner.
• To evaluate the feasibility and accuracy of MEDITATE for acquiring diffusion tensor maps.
• To compare MEDITATE performance against standard DTI methods.

Main Methods:

• Implementation of MEDITATE on a 3T clinical scanner, utilizing multiple echoes and diffusion gradients.
• Acquisition of diffusion-weighted images with varying strengths in two scans.
• Testing on phantoms (isotropic and anisotropic) and in vivo skeletal muscle with cardiac gating.
• Comparison with standard twice-refocused spin echo (TRSE) DTI.

Main Results:

• Accurate estimation of DTI parameters (eigenvalues, mean diffusivity, fractional anisotropy) was achieved in two scans.
• Good quantitative agreement was found between MEDITATE and TRSE DTI.
• Correct reproduction of orientation patterns in phantoms and approximate reproduction in vivo.
• Demonstrated feasibility of MEDITATE on a clinical platform.

Conclusions:

• The MEDITATE technique is a feasible method for compressed diffusion encoding on clinical MRI scanners.
• MEDITATE allows for rapid acquisition of DTI parameters, potentially enabling time-sensitive applications.
• Future developments may lead to clinical use for dynamic DTI, particularly in muscle imaging.