Initial experience of generalized intravoxel incoherent motion imaging and diffusion tensor imaging (GIVIM-DTI) in healthy subjects.

PURPOSE

To evaluate the feasibility of combined generalized intravoxel incoherent imaging and diffusion tensor imaging (GIVIM-DTI) to access the renal microstructure and microcirculation with respiratory triggering.

MATERIALS AND METHODS

A total of 28 young healthy volunteers with no history of renal disease were recruited into our study. GIVIM-DTI images were acquired with respiratory triggering at 3 Tesla. The following diffusion and pseudodiffusion parameters were obtained: pure tissue diffusion ( Ds), fractional anisotropy (FA), mean diffusivity (MD), mean pseudodiffusion ( D¯), perfusion volume fraction ( fp), dispersion of pseudodiffusion ( σ), and an estimate of the microcirculation flow velocity ( fp⋅D¯). The renal left-right difference was analyzed using a paired t-test. The corticomedullary difference was assessed using the one-way analysis of variance test. The reliability of individual parameters was evaluated with the coefficient of variation (CV).

RESULTS

Among all parameters, only the cortical fp showed a bilateral difference (P = 0.045). The cortical fp and σ were significantly higher (P < 0.001 for both) than those in the medulla, but D¯ was significantly lower (P < 0.001) in the cortex, and the fp⋅D¯ values showed no significant corticomedullary difference (P = 0.068). The diffusion parameters Ds and MD were significantly higher (P < 0.001 for both) in the cortex than in the medulla. The cortical FA was significantly lower (P < 0.001) than the corresponding medullary value. Good consistency (CV < 20%) was obtained in the values of Ds, FA, and MD, moderate consistency (CV < 50%) in fp, and poor consistency (CV > 50%) was found in D¯, σ and fp⋅D¯.

CONCLUSION

GIVIM-DTI shows promise for advancing the characterization of the renal microstructure and microcirculation. J. Magn. Reson. Imaging 2016;44:732-738.