A separable least squares approach for intravoxel incoherent motion (IVIM) MRI

Abstract

Intravoxel incoherent motion (IVIM) MRI allows measuring pseudo perfusion as an extension to diffusion weighted imaging (DWI) measures such as the apparent diffusion coefficient (ADC). Recent applications in oncology makes it an attractive addition to the traditional ADC measurements which could help capturing potential microstructural alterations in disease. However, the use of two compartments model, such as in IVIM, is susceptible to numerical issues and are traditionally solved using nonlinear least squares method. We investigate the stability and precision of recovered IVIM parameters by making use instead of separable nonlinear least squares and optionally the addition of a constant compartment.