Correlation analysis of structural and biomechanical properties of hepatocellular carcinoma tissue

It is known that biomechanical and structural properties of tumor tissues are potential biomarkers for the diagnosis and prognosis of tumors such as Hepatocellular carcinoma (HCC). Although there are many studies on the characterization of biomechanical properties of HCC at the cellular level, limited information is known from in vitro studies. Here, tissue samples from 14 patients diagnosed with HCC were analyzed. Indentation tests showed the instantaneous shear modulus and long-term shear modulus of the HCC tissue were 1.19 ± 0.86 kPa and 0.29 ± 0.25 kPa, respectively. The volume fraction of collagen fibers estimated by analyzing the histology images was positively correlated with either instantaneous shear modulus (r = 0.64, p = 0.016) or long-term shear modulus (r = 0.76, p = 0.002). Diffusion-weighted images with 13b-values were also collected and the diffusivity from Intravoxel Incoherent Motion (IVIM) and Diffusion Kurtosis Imaging (DKI) models were 1.09 ± 0.47 ∙ 10^-3 mm²/s and 2.06 ± 0.83∙10^-3 mm²/s, respectively. Significant positive correlations were observed between long-term shear modulus and the diffusivity estimated from IVIM (r = 0.600, p = 0.026). The shifted apparent diffusion coefficient (ADC) estimated based on b = 600 and 2000 s/mm² was negatively correlated with both instantaneous shear modulus (r = -0.745, p = 0.003) and long-term shear modulus (r = -0.591, p = 0.029). In addition, the diffusivity and non-Gaussian Kurtosis parameters estimated at different b values showed a significant negative correlation (r = -0.675, p = 0.010). Results revealed the close relationships between the structural and biomechanical properties of HCC tissue. The interrelation of diffusion and biomechanical properties are not only crucial for HCC characterization but could also provide helpful information for HCC diagnosis and prognosis.