Comparison of monoexponential, intravoxel incoherent motion diffusion-weighted imaging and diffusion kurtosis imaging for assessment of hepatic fibrosis

Background Hepatic fibrosis is a dynamic, reversible process which can result in liver failure. Diagnosis and monitoring of hepatic fibrosis are clinically important. Purpose To compare the diagnostic performance of diffusion kurtosis imaging (DKI), intravoxel incoherent motion (IVIM), and monoexponential diffusion-weighted imaging (DWI) to detect clinically significant fibrosis (>= F2). Material and Methods This retrospective study was approved by Institutional Review Board and the requirement of informed consent was waived. One hundred and six patients were included who underwent liver multiple b-value DWI (10 b-values at 0-1000 s/mm(2)) at 1.5 T and were histologically diagnosed with hepatic fibrosis. Apparent diffusion coefficient (ADC), DKI-derived apparent kurtosis (Kapp) and diffusivity (Dapp), and IVIM-derived true diffusion (Dt), pseudodiffusion (D*), and perfusion fraction (f) were compared between no or early fibrosis (F0-1, n = 19) and clinically significant fibrosis (>= F2, n = 87). Diagnostic performance was evaluated with receiver operating characteristic (ROC) analysis. Results F2-4 had a significantly lower D* (59.9 +/- 16.3 vs. 86.2 +/- 21.0 [x10(-3) mm(2)/s]) and Dapp (3.46 +/- 0.79 vs. 4.07 +/- 0.76 [x10(-3) mm(2)/s]) but higher Kapp (1.10 +/- 0.18 vs. 0.98 +/- 0.12) than F0-1 (P < 0.01). ADC, Dt, and f did not show significant difference between two groups (P > 0.05). The area under the ROC curve for diagnosis of clinically significant fibrosis (>= F2) was significantly larger in D* (0.89; 95% CI = 0.81-0.94) than Dapp (0.73; 95% CI = 0.63-0.81) and Kapp (0.75; 95% CI = 0.65-0.83) (P = 0.017 and 0.012, respectively). Conclusion IVIM-DWI might be more suitable for detecting hepatic fibrosis than the monoexponential and kurtosis model, and D* showed a better diagnostic performance to detect clinically significant fibrosis than other parameters.