Abstract
Background and aims. Liver mechanical properties’ (stiffness/viscoelasticity) evaluation is relevant for diagnosing/monitoring liver fibrosis. Due to limitations of the commonly used elastography, we propose the use of rheology and Low Field-Nuclear Magnetic Resonance (LF-NMR). Methods. In 30 liver samples from patients undergoing bariatric surgery and 18 control samples, we evaluated the shear modulus G/critical stress τc (elastic properties) and mean complex modulus 𝐺∗a (elastic/viscous properties) by rheology. LF-NMR was used to measure the spin–spin relaxation time (T2m), reflecting iron content. The expression of iron-related proteins and of pro-fibrotic proteins were evaluated by qRT-PCR. Tissue histology was also determined. Results. 𝐺∗a/G/τc were higher in pathological samples, which also showed increased expression of pro-fibrotic proteins. Fibrosis determination displayed a correspondence of 4/30 samples for elastography/histology and 17/30 for rheology/histology. T2m was significantly lower in pathological livers, indicating iron accumulation as confirmed by increased expression of iron-related proteins. T2m was more effective than histology in detecting iron. An inverse correlation was observed between T2m and 𝐺∗a/G showing that iron accumulation is associated with increased liver elasticity/viscoelasticity, i.e., fibrosis. Additionally, an inverse correlation of 𝐺∗a/G with transferrin, was observed. Conclusion. As our patients mostly have mild liver fibrosis, the combined use of rheology/LF-NMR can effectively detect early changes in liver mechanical properties, aiding in staging and diagnosis of fibrosis.
Biasin, A., Palmisano, S., Abrami, M., Bonazza, D., Zanconati, F., Tierno, D., Tonon, F., Truong, N.H., Dang Minh, T., Weiskirchen, R., Felluga, F., Scaggiante, B., Grassi, M. and Grassi, G. (2026) International Journal of Molecular Sciences, 27(9), p. 4040.