The influence of static portal pressure on liver biophysical properties

• Published in: Acta biomaterialia 2023-10, Vol.169, p.118-129
• Main Authors: Safraou, Yasmine, Krehl, Karolina, Meyer, Tom, Mehrgan, Shahryari, Jordan, Jakob Ernst Luis, Tzschätzsch, Heiko, Fischer, Thomas, Asbach, Patrick, Braun, Jürgen, Sack, Ingolf, Guo, Jing
• Format: Article
• Language: English
• Subjects: Diffusion-weighted imaging (DWI); Fluid viscosity; Liver; Liver confinement; Magnetic resonance elastography (MRE); Portal pressure; Stiffness; Vascular permeability
• ISSN: 1742-7061; 1878-7568; 1878-7568
• DOI: 10.1016/j.actbio.2023.07.033

The liver is a highly vascularized organ where fluid properties, including vascular pressure, vessel integrity and fluid viscosity, play a critical role in gross mechanical properties. To study the effects of portal pressure, liver confinement, fluid viscosity, and tissue crosslinking on liver stiffness, water diffusion, and vessel size, we applied multiparametric magnetic resonance imaging (mpMRI), including multifrequency magnetic resonance elastography (MRE) and apparent diffusion coefficient (ADC) measurements, to ex vivo livers from healthy male rats (13.6±1.6 weeks) at room temperature. Four scenarios including altered liver confinement, tissue crosslinking, and vascular fluid viscosity were investigated with mpMRI at different portal pressure levels (0-17.5 cmH2O). Our experiments demonstrated that, with increasing portal pressure, rat livers showed higher water content, water diffusivity, and increased vessel sizes quantified by the vessel tissue volume fraction (VTVF). These effects were most pronounced in native, unconfined livers (VTVF: 300±120%, p