Spatially Constrained Model of Body Diffusion-Weighted MRI Signal Decay Increases Precision of Parameter Estimates

Moti Freiman¹, Jeannette M. Perez-Rossello¹, Michael J. Callahan¹, Robert V. Mulkern¹, Stephan D. Voss¹, Simon K. Warfield¹

The role of incoherent motion parameters as quantitative imaging biomarkers for various clinical applications is becoming increasingly important. However, the IVIM model of DW-MRI signal decay does not count for inter-voxel incoherent motion. Thus, incoherent motion parameter estimates are not reliable or specific enough. In this work, we improved the precision of incoherent motion measurements from DW-MRI data significantly by introducing a spatially constrained model of DW-MRI signal decay (IM). We demonstrated the improvement achieved by using our IM model using in-vivo abdominal DW-MRI data of 30 patients. The spatially constrained IM model provides more precise insight to the physiological causes of the DW-MRI signal decay than the IVIM model.