Application of Magnetic Resonance Imaging in Liver Biomechanics: A Systematic Review

Abstract

MRI-based biomechanical studies can provide a deep understanding of the mechanisms governing liver function, its mechanical performance but also liver diseases. In addition, comprehensive modeling of the liver can help improve liver disease treatment. Furthermore, such studies demonstrate the beginning of an engineering-level approach to how the liver disease affects material properties and liver function. Aimed at researchers in the field of MRI-based liver simulation, research articles pertinent to MRI-based liver modeling were identified, reviewed, and summarized systematically. Various MRI applications for liver biomechanics are highlighted, and the limitations of different viscoelastic models used in magnetic resonance elastography are addressed. The clinical application of the simulations and the diseases studied are also discussed. Based on the developed questionnaire, the papers' quality was assessed, and of the 46 reviewed papers, 32 papers were determined to be of high-quality. Due to the lack of the suitable material models for different liver diseases studied by magnetic resonance elastography, researchers may consider the effect of liver diseases on constitutive models. In the future, research groups may incorporate various aspects of machine learning (ML) into constitutive models and MRI data extraction to further refine the study methodology. Moreover, researchers should strive for further reproducibility and rigorous model validation and verification.

Polydatin attenuates tubulointerstitial fibrosis in diabetic kidney disease by inhibiting YAP expression and nuclear translocation

“…This study evaluated the role of PD in regulating the mechanotransduction pathway of renal fibroblasts, with the following highlights: 1) For the first time, based on real kidney stiffness in different stages of renal fibrosis in DKD rats, we prepared a PA gel system which can simulate the real ECM stiffness environment of kidney tissue in vivo and confirmed that pathological matrix stiffness promoted the expression of α-SMA and collagen I, YAP nuclear translocation and ROS production in fibroblasts; 2) For the first time, using the in vitro model of renal fibroblasts cultured in PA hydrogels with different stiffness and the in vivo model of DKD rats intervened by PD or VP (a pharmacological inhibitor of YAP), we proved that PD can delay fibrosis progression via a mechanism that is dependent, at least in part, on inhibiting YAP expression and nuclear translocation. Magnetic resonance elastography (MRE) and ultrasound shear wave elastography (SWE) have emerged as preferred non-invasive techniques for the clinical assessment of the fibrotic tissue stiffness, but the confounding factors owing to the complex architecture and mechanical properties of the kidney, such as renal anisotropy, tissue viscoelasticity and renal hemodynamics, influence the reliability and Frontiers in Physiology frontiersin.org accuracy of the measurement results obtained (Lim et al, 2021;Seyedpour et al, 2021). Nanoindentation technology and atomic force microscopy (AFM) have high spatial resolution and mechanical sensitivity, which have been widely used to measure the mechanical properties of biomaterials and tissues (Wu et al, 2020).…”

Imaging Methods Applicable in the Diagnostics of Alzheimer’s Disease, Considering the Involvement of Insulin Resistance

“…The common hepatic MRI examination consists of T 1 - and T 2 -weighted MRI for assessing hepatic lipid and/or iron content but can be extended by gadolinium-enhanced T 1 -weighted MRI for grading more severe acute hepatitis and fibrosis and for delineating vascular abnormalities [ 177 , 178 ]. Another increasingly applied method is MR elastography (MRE), the principle of which is based on an image-encoding response of the stimulated soft tissue produced by harmonic mechanical vibrations and the reconstruction of parameters denoting viscoelastic (i.e., the degree of liver stiffness) tissue properties [ 174 , 175 , 179 ]. Hepatic MRE enables an examination of the entire liver and is suitable as a screening method for liver fibrosis [ 177 , 179 , 180 ].…”

“…Another increasingly applied method is MR elastography (MRE), the principle of which is based on an image-encoding response of the stimulated soft tissue produced by harmonic mechanical vibrations and the reconstruction of parameters denoting viscoelastic (i.e., the degree of liver stiffness) tissue properties [ 174 , 175 , 179 ]. Hepatic MRE enables an examination of the entire liver and is suitable as a screening method for liver fibrosis [ 177 , 179 , 180 ]. The variety of MR modalities facilitates the evaluation of abnormal liver fatty infiltration (e.g., T 1 -weighted fast spoiled gradient echo [ 178 ], MRI-estimated proton density fat fraction [ 180 ], in-phase and opposed-phase imaging [ 174 ], and Dixon sequences or 1 H MRS [ 181 ]) based on distinguishing the fat–water composition within soft tissues.…”

From Seeing to Simulating: A Survey of Imaging Techniques and Spatially-Resolved Data for Developing Multiscale Computational Models of Liver Regeneration

“…While all three techniques can be utilized for volumetric measurements of the liver, MRI offers higher soft tissue contrast compared to CT and ultrasound. A recent review article highlights the application of MRI-based liver modeling in understanding liver biomechanics and improving liver disease treatment (Seyedpour et al, 2021). Studying biomechanics of the liver aided by MRI allows for predictive modeling of liver diseases to identify and better understand the progressive stages ahead.…”