Investigation of diffusion time dependence of apparent diffusion coefficient and intravoxel incoherent motion parameters in the human kidney
Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Purpose
To characterize the diffusion time (Δ eff ) dependence of apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM)-related parameters in the human kidney at 3T.
Methods
Sixteen healthy volunteers underwent an MRI examination at 3T including DWI at different Δ eff ranging from 24.1 ms to 104.1 ms. The extended mono-exponential ADC, and IVIM models were fitted to the data for each Δ eff , and medullary and cortical ADC, (pseudo-) diffusion coefficients (D* and D) and flow-related signal fraction (f) were calculated.
Results
When all the data was used for fitting, a trend toward higher ADC with increasing Δ eff was observed between 24.1 and 104.1 ms ([median and interquartile range]: 2.10 [1.94 2.26] to 2.36 [2.09 2.69] x10 −3 mm 2 /s for cortex, and 2.24 [2.10 2.36] to 2.64 [2.49 2.78] x10 −3 mm 2 /s for medulla). In contrast, no significant differences in ADC were found when only the data acquired at b-values higher than 200 s/mm 2 was used for fitting. When the IVIM model was applied, cortical and medullary f increased significantly (cortex: 0.24 [0.22 0.30] to 0.54 [0.43 0.63] x10 −3 mm 2 /s; medulla: 0.26 [0.23 0.38] to 0.50 [0.39 0.62] x10 −3 mm 2 /s) and cortical D (cortex: 1.66 [1.59 1.71] to 1.24 [1.10 1.47] x10 −3 mm 2 /s) and cortical D* (cortex: 9.10 [5.50 12.9] to 4.19 [3.84 5.73] x10 −3 mm 2 /s) decreased significantly between 24.1 and 104.1 ms.
Conclusion
Renal perfusion and tubular flow substantially contribute to the observed increase in ADC over a wide range of Δ eff between 24 and 104 ms.
