Reliable estimation of incoherent motion parametric maps from diffusion-weighted MRI using fusion bootstrap moves

Area of Science:

• Medical Imaging
• Biophysics
• Radiology

Background:

• Diffusion-weighted MRI (DW-MRI) offers insights into physiological and microstructural properties.
• The Intra-Voxel Incoherent Motion (IVIM) model quantifies parameters like blood flow (D*) and diffusivity (D).
• Independent voxel-wise fitting of the IVIM model yields imprecise parameter estimates, limiting clinical utility.

Purpose of the Study:

• To enhance the precision of DW-MRI parameter estimates using a novel approach.
• To introduce a spatially-constrained Incoherent Motion (IM) model and an efficient Fusion Bootstrap Moves (FBM) solver.
• To improve the characterization of heterogeneous biological environments, such as tumors and lesions.

Main Methods:

• Development of a spatially-constrained Incoherent Motion (IM) model for DW-MRI signal decay.
• Implementation of an iterative Fusion Bootstrap Moves (FBM) solver utilizing graph-cut optimization.
• Validation using simulated data and in vivo DW-MRI data from abdominal tumors and musculoskeletal lesions.

Main Results:

• The IM-FBM method significantly reduced the relative root mean square error for D* (80%) and f/D (50%) compared to IVIM on simulated data.
• In vivo analysis showed IM-FBM reduced the coefficient of variation for D* (43%), f (37%), and D (17%) estimates.
• Characterization of heterogeneous musculoskeletal lesions improved with a 19.3% increase in contrast-to-noise ratio.

Conclusions:

• The combined IM model and FBM solver provide more precise physiological parameter estimates from DW-MRI signal decay.
• This approach offers a superior mechanism for characterizing heterogeneous lesions compared to traditional IVIM methods.
• The enhanced precision and characterization capabilities hold promise for improved diagnostic accuracy in clinical settings.