Effect of Fat: Assessment of Apparent Diffusion Coefficient

Over the past two decades, diffusion-weighted imaging (DWI) has evolved to an important tool for studying neurological disorders (1-3), while application of this method for characterization of abdominal pathological conditions awaited improved hardware and robust pulse sequences over nearly a decade (4). In the kidney, DWI has been used to investigate chronic kidney disease (CKD) (5), renal lesions (6), and deteriorating allografts (7). Nevertheless, the contribution of tubular flow and hemodynamics to the apparent diffusion constant (ADC), the diffusion quantitative index of the single compartment mono-exponential model, complicates tissue characterization and renal DWI analysis (8). This encouraged implementation of models incorporating a larger number of compartments to differentiate pure diffusion from pseudo-diffusive components. Indeed, in the kidney the intra-voxel incoherent motion (IVIM) analytical method, which utilizes a two-compartment model associated with pure diffusion and flow, showed superiority over the mono-exponential decay model (9, 10).