Estimating the Patient-Specific Relative Stiffness Between a Hepatic Lesion and the Liver Parenchyma

This paper presents a novel non-invasive methodology to obtain the patient-specific relative stiffness between a hepatic lesion and the liver parenchyma in vivo. This relative stiffness can be used as a biomarker about the type of lesion. This biomarker together with the rest of pathological information can be used to plan a biopsy, an image-guide intervention or a radiation therapy. This relative stiffness is estimated by means of the finite element simulation of the breathing process, which is embedded in an optimization routine based on genetic algorithms. This routine was aimed at finding the patient-specific relative stiffness between a hepatic lesion and the liver parenchyma for the proposed model. The feasibility of the proposed methodology was proved first with a synthetic case, where the relative stiffness factor between liver and a tumour were known and the algorithm performed a blind search of it. After that, the methodology was applied to real cases. The results show the good performance of the proposed methodology since the deformation of the tumors were detected with a mean error low.