Dual-Probe Shear Wave Elastography in a Transversely Isotropic Phantom

This project aimed to evaluate the possibility of obtaining a full mechanical characterization of a transversely isotropic (TI) phantom with dual-probe SWE. A TI phantom was developed and mechanical tests were performed to verify its anisotropy. Moreover, multiple wave propagation modes calculated with dual-probe SWE showed a good agreement with the theoretical curves and indicated the possibility of measuring all the elasticity constants needed to fully characterize a TI tissueope

Dual-Probe Shear Wave Elastography in a Transversely Isotropic Phantom

Shear Wave Elastography (SWE) is an ultrasound based technique which is able to measure tissue stiffness through the speed of induced shear waves. Tissue stiffness is often related to pathological conditions and detecting mechanical changes can help the recognition of potential diseases. The clinical use of SWE is limited to isotropic tissue due to the difficulty in assessing a theoretical model for more complex tissue and this project therefore aimed to evaluate the possibility of obtaining a full mechanical characterization of a transversely isotropic (TI) phantom with dual-probe SWE. A TI hydrogel phantom was developed and mechanical tests were performed to verify its anisotropy and determine the elastic moduli in both the perpendicular and longitudinal directions. Shear moduli were estimated using conventional and dual-probe SWE comparing the results to theoretical pure-transverse (PT) and quasi-transverse (QT) wave propagation modes. Both mechanical and SWE tests showed that the phantoms were transversely isotropic ET/EL=0.81. Moreover, multiple wave propagation modes calculated with dual-probe SWE showed a good agreement with the theoretical curves and indicated the possibility of measuring all the elasticity constants needed to fully characterize an incompressible, TI tissue with dual-probe SWE

Applicazione dell'analisi del cammino alla prevenzione del piede diabetico tramite solette baropodometriche

Lo scopo della tesi è stato verificare se l'attività fisica potesse prevenire il piede diabetico tramite un protocollo di cammino su treadmill utilizzando EMG e solette baropodometriche.Questi dati sono stati poi analizzati tramite i programmi Pedar-x online, Matlab e SPSS Statistic.L'esercizio ha influito sui pazienti diabetici con e senza vasculopatia,al contrario dei controlli.La baropodometria è quindi utile per valutare gli effetti dell'esercizio che risulta valido per la prevenzion

Acquisition of multiple mode shear wave propagation in transversely isotropic medium using dualprobe setup

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Smart Ultrasound Device for Non-Invasive Real-Time Myocardial Stiffness Quantification of the Human Heart

International audienceQuantitative assessment of myocardial stiffness is crucial to understand and evaluate cardiac biomechanics and function. Despite the recent progresses of ultrasonic shear wave elastography, quantitative evaluation of myocardial stiffness still remains a challenge because of myocardium location, motion, large elasticity changes and strong elastic anisotropy. In this paper we introduce a smart ultrasound approach for non-invasive real-time quantification of shear wave velocity (SWV) and elastic fractional anisotropy (FA) in locally transverse isotropic elastic medium such as the myocardium. We demonstrated, that this approach can quantify accurately SWV in the range of 1.5 to 6 m/s in transverse isotropic medium (FA<0.7) using numerical simulations. The approach was experimentally validated on calibrated phantoms and anisotropic ex vivo tissues. A mean absolute error of 0.22 m/s was found when compared to gold standard measurements. Finally, in vivo feasibility of myocardial anisotropic stiffness assessment was evaluated in four healthy volunteers on the antero-septo basal segment and on anterior free wall of the right ventricule (RV) in end-diastole. A mean longitudinal SWV of 1.08 ± 0.20 m/s was measured on the RV and 1.74 ± 0.51 m/s on the Septum with a good intra-volunteer reproducibility (± 0.18 m/s). This approach has the potential to become a clinical tool for the quantitative evaluation of myocardial stiffness and diastolic function