Hepatic Steatosis Decreases Diffusion Parameters in Diffusion-Weighted Imaging With Monte Carlo Simulation and...

Area of Science:

• Medical Imaging
• Biophysics
• Liver Disease Research

Background:

• Hepatic steatosis affects liver tissue properties.
• Diffusion-weighted imaging (DWI) parameters like ADC and D are sensitive to tissue microstructural changes.
• Accurate calibration of DWI parameters is crucial for reliable liver disease assessment.

Purpose of the Study:

• To calibrate the impact of hepatic steatosis on apparent diffusion coefficient (ADC) and pure diffusion coefficient (D).
• To utilize Monte Carlo simulations and phantom studies for precise calibration.

Main Methods:

• Constructed virtual liver models with varying fat droplet characteristics.
• Simulated magnetic fields and proton dynamics to predict DWI signals and diffusion parameters.
• Conducted phantom studies to correlate proton density fat fraction (PDFF) with diffusion parameters.

Main Results:

• Simulation and phantom studies revealed a linear negative correlation between fat fraction (FF) and both ADC and D (r ≤ -0.895).
• Simulations accurately predicted diffusion parameters when incorporating specific fat susceptibility and proton diffusivity values.
• Hepatic steatosis was confirmed to decrease diffusion parameters.

Conclusions:

• Hepatic steatosis significantly decreases ADC and D values.
• Calibration of diffusion parameters is necessary for accurate DWI-based assessment of liver fibrosis in the presence of steatosis.