A combined use of intravoxel incoherent motion MRI parameters can differentiate early stage hepatitis-b fibrotic livers from healthy livers

Abstract

This study investigated a combined use of IVIM parameters Dslow (D), PF (f) and Dfast (D*) for liver fibrosis evaluation. 16 healthy volunteers (F0) and 33 hepatitis-b patients (stage F1= 15, stage F2-4 = 18) were included. With a 1.5-T MR scanner and respiration-gating, IVIM diffusion weighted imaging was acquired using a single-shot echo-planar imaging sequence with ten b-values of 10, 20, 40, 60, 80, 100, 150, 200, 400, and 800 s/mm2. Signal measurement was performed on right liver parenchyma. With a 3-dimensional tool, Dslow, PF, and Dfast values were placed along the x-axis, y-axis, and z-axis, and a plane was defined to separate healthy volunteers from patients. 3-dimensional tool demonstrated healthy volunteers and all patients with liver fibrosis could be separated. Classification and Regression Tree showed a combination of PF (PF < 12.55%), Dslow (Dslow < 1.152 ×10−3 mm2/s) and Dfast (Dfast <13.36 ×10−3 mm2/s) could differentiate healthy subjects and all fibrotic livers (F1-F4) with an area under the curve of logistic regression (AUC) of 0.986. The AUC for differentiation of healthy livers vs. F2-4 livers was 1. PF offered the best diagnostic value, followed by Dslow; however, all three parameters of PF, Dslow, and Dfast contributed to liver fibrosis detection.

Comparison of tri‐exponential decay versus bi‐exponential decay and full fitting versus segmented fitting for modeling liver intravoxel incoherent motion diffusion MRI

“…This highlights the limitation of accurate D' Vfast value estimation. Interestingly, in a previous study where the lowest b-value was b = 10 s/mm 2 , reducing the tri-exponential to a bi-exponential model, 17 the D fast value was 12.34 ± 3.06 × 10 −3 mm 2 /s, thus close to our D' fast value (≈15 × 10 −3 mm 2 /s).…”

“…Note that adjusted R 2 is a better indicator when comparing nested models, since its calculation takes into account the number of parameters (References and Supplementary Document 2). Using ROI analysis, an R 2 value higher than 0.95 generally indicates good fit …”

“…Using ROI analysis, an R 2 value higher than 0.95 generally indicates good fit. 11,16,17 In addition to the IVIM parameter estimation based on individual scans, the measured signals at each b-value from the 50 scans were additionally averaged together; the averaged signals (total-averaged) were then fitted with the four approaches as they were from a single scan. 6,18 To…”

An interesting approach for the diagnosis of hepatic fibrosis: Wáng et al., “A combined use of intravoxel incoherent motion MRI parameters can differentiate early-stage hepatitis-b fibrotic livers from healthy livers”

“…Recently, Wáng and colleagues provided a particularly interesting work on application of IVIM diffusion imaging for the diagnosis of hepatic fibrosis without steatosis (8). The methodology used is original.…”

Validation study of a diffusion MRI derived vessel density biomarker for detecting viral hepatitis-b induced liver fibrosis

“…Wang et al [1, 5], Huang et al [2], and Li et al [6] recently demonstrated that Diffusion MRI derived IVIM measurements can offer high performance in detecting liver fibrosis. However, the disadvantages of IVIM measurement include long scan time to acquire multiple b -value imaging data, and this itself is often associated with respiration induced motion artefacts.…”