Non‐gaussian diffusion evaluation of the human kidney by Padé exponent model. Issue 1 (4th May 2017)

• Record Type: Journal Article
• Authors: Ljimani, Alexandra; Lanzman, Rotem S.; Müller‐Lutz, Anja; Antoch, Gerald; Wittsack, Hans‐Jörg
• Is Part Of: Journal of magnetic resonance imaging. Volume 47:Issue 1(2018)
• Page Start: 160
• Page End: 167
• Publication Date: 2017-05-04
• Subjects: renal fMRI -- DWI -- non‐Gaussian diffusion -- Padé exponent model; Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.25742
• Languages: English
• ISSNs: 1053-1807

Abstract

Abstract : 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/mm 2 ]; 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 R 2 ‐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 < 0.05), which enables more precise information about the deviation of the Gaussian behavior of the diffusion signal by the PEM. The biexponential model showed better fitting to the diffusion signal (medullar R bi 2 0.989 ± 0.008, AICcbi 113.3 ± 6.6; cortical R bi 2 0.992 ± 0.006, AICcbi 113.3 ± 5.2) than the three‐parameter models (medullar R Pad é 2 0.965 ± 0.016, AICcPadé 122.6 ± 6.4, R K 2 0.954 ± 0.019, AICcK 128.5 ± 6.0; cortical R Pad é 2 0.989 ± 0.005, AICcPadé 116.3 ± 4.4, R K 2 0.985 ± 0.007, AICcK 120.4 ± 4.8). The monoexponential model fits least to the diffusion signal in the kidney (medullar R mono 2 0.898 ± 0.039, AICcmono 141.4 ± 5.6; cortical R mono 2 0.961 ± 0.013, AICcmono 135.4 ± 4.8). Conclusion: The PEM is a novel promising approach to quantify diffusion properties in the human kidney and might further improve functional renal MR imaging. Level of Evidence: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:160–167.