A new paper An image-based approach for the estimation of arterial local stiffness in vivo has been published in the Frontiers in Bioengineering and Biotechnology journal in collaboration with the MeDiTATe project.

The paper was written by Simona Celi, Emanuele Gasparotti, Katia Capellini and Emanuele Vignali from BioCardioLab (Fondazione Toscana G. Monasterio), Francesco Bardi (ESR 10), Martino Andrea Scarpolini (ESR 09), Carlo Cavaliere (IRCCS SynLab SDN) e Filippo Cademartiri (Dipartimento Immagini, Fondazione Toscana Gabriele Monasterio).

Here follows the paper’s abstract:

The analysis of mechanobiology of arterial tissues remains an important topic of research for cardiovascular pathologies evaluation. In the current state of the art, the gold standard to characterize the tissue mechanical behavior is represented by experimental tests, requiring the harvesting of ex-vivo specimens. In recent years though, image-based techniques for the in vivo estimation of arterial tissue stiffness were presented. The aim of this study is to define a new approach to provide local distribution of arterial stiffness, estimated as the linearized Young’s Modulus, based on the knowledge of in vivo patient-specific imaging data. In particular, the strain and stress are estimated with sectional contour length ratios and a Laplace hypothesis/inverse engineering approach, respectively, and then used to calculate the Young’s Modulus. After describing the method, this was validated by using a set of Finite Element simulations as input. In particular, idealized cylinder and elbow shapes plus a single patient-specific geometry were simulated. Different stiffness distributions were tested for the simulated patient-specific case. After the validation from Finite Element data, the method was then applied to patient-specific ECG-gated Computed Tomography data by also introducing a mesh morphing approach to map the aortic surface along the cardiac phases. The validation process revealed satisfactory results. In the simulated patient-specific case, root mean square percentage errors below 10% for the homogeneous distribution and below 20% for proximal/distal distribution of stiffness. The method was then successfully used on the three ECG-gated patient-specific cases. The resulting distributions of stiffness exhibited significant heterogeneity, nevertheless the resulting Young’s moduli were always contained within the 1–3 MPa range, which is in line with literature.