Ground truth hardware phantoms for validation of diffusion-weighted MRI applications

Area of Science:

• Neuroimaging
• Biomedical Engineering
• Medical Physics

Background:

• Diffusion-weighted MRI (DW-MRI) is vital for neuroimaging, but its quantitative validation remains challenging.
• Accurate fiber tracking and diffusion modeling are critical for understanding white matter structure and pathology.
• Existing validation methods often lack the precision to assess sub-voxel crossing fiber complexities.

Purpose of the Study:

• To introduce a novel hardware phantom for the quantitative validation of DW-MRI applications.
• To provide a platform for validating DW-MRI acquisition, diffusion modeling, and fiber tracking algorithms.
• To address the recurrent issue of validating DW-MRI techniques in complex white matter environments.

Main Methods:

• Developed a hardware phantom with polyester fibers mimicking human white matter properties (anisotropy, FA, T2).
• Constructed sub-voxel crossing fiber configurations at 30, 50, and 65 degrees.
• Acquired DW-MRI data using a clinical protocol and analyzed diffusion profiles with advanced reconstruction methods (DOT, q-ball).

Main Results:

• The phantom successfully enabled estimation of diffusion tensor and non-Gaussian diffusion models.
• Streamline fiber tracking was effectively performed using data acquired from the phantom.
• Multimodal diffusion profiles were revealed in voxels with crossing fibers, validating reconstruction techniques.

Conclusions:

• The developed phantoms offer a versatile platform for DW-MRI validation.
• Applications include optimizing acquisition schemes, validating diffusion models, and comparing fiber tracking algorithms.
• This platform is essential for quality control in multi-center diffusion imaging studies.