Anna
Caroli1, Luca Antiga1, Giuseppe Petralia2,
Massimo Bellomi2, Andrea Remuzzi1,3, Paul Summers2
1Bioengineering Department, Mario Negri
Institute for Pharmacological Research, Bergamo, Italy; 2Division
of Radiology, European Institute of Oncology, Milan, Italy; 3University
of Bergamo, Bergamo, Italy
Mono-exponential
models do not accurately predict diffusion-weighted signal decay in the
kidney, while bi-exponential models are unable to differentiate contributions.
We propose a piece-wise exponential model, separately fitting low and high
b-values with two exponentials, expressive of fast and slow transport
components. Ten healthy volunteers underwent DWI both pre- and post-lunch,
and acquisitions were repeated within one of the two sessions. The model was
stable, and accurately fit signal attenuation. Diffusion parameters showed
high repeatability, but significant differences between pre- and post-meal
acquisitions. These results point out the need for more complete
interpretations of DWI signal in describing the complex transport in the
kidney.