Characterizing the compression-dependent viscoelastic properties of human hepatic pathologies using dynamic compression testing

Abstract

Recent advances in elastography have provided several imaging modalities capable of quantifying the elasticity of tissue, an intrinsic tissue property. This information is useful for determining tumour margins and may also be useful for diagnosing specific tumour types. In this study, we used dynamic compression testing to quantify the viscoelastic properties of 16 human hepatic primary and secondary malignancies and their corresponding background tissue obtained following surgical resection. Two additional backgrounds were also tested. An analysis of the background tissue showed that F4-graded fibrotic liver tissue was significantly stiffer than F0-graded tissue, with a modulus contrast of 4:1. Steatotic liver tissue was slightly stiffer than normal liver tissue, but not significantly so. The tumour-to-background storage modulus contrast of hepatocellular carcinomas, a primary tumour, was approximately 1:1, and the contrast decreased with increasing fibrosis grade of the background tissue. Ramp testing showed that the background stiffness increased faster than the malignant tissue. Conversely, secondary tumours were typically much stiffer than the surrounding background, with a tumour-to-background contrast of 10:1 for colon metastases and 10:1 for cholangiocarcinomas. Ramp testing showed that colon metastases stiffened faster than their corresponding backgrounds. These data have provided insights into the mechanical properties of specific tumour types, which may prove beneficial as the use of quantitative stiffness imaging increases.

Indentation loading response of a resonance sensor—discriminating prostate cancer and normal tissue

“…the PCa to normal tissue contrast could be of similar magnitude whether measured ex vivo or in vivo. A similar discussion was given for measurements on liver tissue ex vivo with dynamic compression testing [28]. Our results are promising for further studies on prostate tissue in vivo.…”

The nano-epsilon dot method for strain rate viscoelastic characterisation of soft biomaterials by spherical nano-indentation

“…Because very small forces are applied, the technique is well suited for soft biomaterials (Karimzadeh and Ayatollahi, 2014;Rettler et al, 2013), such as hydrogels (Ebenstein and Pruitt, 2004;Kaufman et al, 2008), which due to their pliable and highly hydrated nature, are a challenge to characterise using macro-scale techniques. Finally, given that pathological and ageing tissues are known to exhibit altered mechanical properties (Derby and Akhtar, 2015;DeWall et al, 2012), this method is also attractive in the biomedical context as a potential diagnostic tool or for intelligent scaffold design (Albert et al, 2013;Lyyra et al, 1995;Mattei et al, 2015).…”

Aim: To investigate the value of ElastPQ measurement for differential diagnosis of benign and malignant focal liver lesions (FLLs) by using histologic results as a reference standard. Material and methods: A total of 154 patients were included. ElastPQ measurement was performed for each lesion in which the shear wave speed (SWS) was measured. The difference in SWS and SWS ratio of FLL to surrounding liver were evaluated, and the cut off value was investigated. Receiver operating characteristic (ROC) curve

“…Previous studies proved that hepatocellular carcinoma (HCCs) were relatively soft compared with the background liver, when compared with other malignancy groups [14,26,30,31]. HCCs in cirrhotic livers exhibited a relatively uniform and soft interior when compared with the stiff and heterogeneous surrounding parenchyma.…”

“…ElastPQ measurement might be helpful in differentiation of hepatic hemangioma from malignant FLLs [30][31][32][33][34][35].…”