Toward optimal fitting parameters for multi-exponential DWI analysis of the kidney: A simulation study comparing different fitting algorithms

Motivation: The use of multi-exponential signal analysis is common practice to identify present diffusion components in diffusion-weighted MRI. Yet, the absence of appropriate acquisition parameters and standardised signal analysis methods hinders the attainment of accurate results, especially in renal imaging. Goal(s): To assess the impact of fitting parameters and methods. Approach: A simulation was conducted comparing non-negative (NNLS) and non-linear (NLLS) fitting methods, but also determining ideal parameters for accurate in-vivo appliance. Results: The study showed superior accuracy when using the NNLS method in combination with area under curve (AUC) estimation and specified an optimized parameters set, improving clinical DWI examinations in kidneys. Impact: By employing our results, it is expected that stable and reliable results can be achieved in multi-exponential analysis of in-vivo DWI data using both NNLS and NLLS approaches. This will enable enhanced evaluation of clinical DWI examinations in the kidney.