Non‐gaussian diffusion evaluation of the human kidney by Padé exponent model

Purpose To evaluate the feasibility of renal diffusion quantification using the Padé exponent model (PEM) in healthy subjects. Materials and Methods Diffusion measurements were completed in 10 healthy subjects (mean age, 32.4 ± 8.9 years) on a 3T MRI scanner (Magnetom Trio, Siemens AG, Germany). A respiratory‐triggered echo planar imaging sequence (15 slices with 6 mm thickness; 16 b‐values [0–750 s/mm2]; three diffusion directions; field of view: 400 × 375 mm; Matrix 192 × 192; repetition time/echo time: 3000/74 ms) was acquired in the coronal direction. Parameter maps were calculated for the monoexponential, biexponential, kurtosis models, and the PEM. A regression analysis using an R2‐test and corrected Akaike information criterion (AICc) was performed to identify the best mathematical fitting to the measured diffusion‐weighted imaging signal decay. Results The mathematical accuracy of the PEM was significantly higher than for the other three‐parameter and the monoexponential model (P