Elastography measurement for soft material using digital holography

The quantitative and qualitative studies of biomechanical properties is an important diagnostic tool for investigating abnormal tissues. Elastography is an experimental technique that is used to characterize soft materials including tissues collagen and fat etc. The existing ultrasound and magnetic-based elastography methods are limited by low spatial resolution and small imaging depth. The optical methods have enormous potential to quantify the elastographic measurement with microscale resolution. So, digital holography can establish a new platform for measuring the bulkelastographic properties of the soft tissues. In this work, we calculate the phase map of the Surface Acoustic Wave (SAW) produced by piezo-transducer on the surface of the tissue phantom using the Digital Holography (DH) imaging method. The temporal phase-shifting algorithm is employed to reconstruct the phase map of the SAW for accurate quantification of surface wave velocity. The precise calculation of surface wave velocity gives the direct measurement of the mechanical parameter like elastic modulus and shear modulus. The preliminary results obtained from the proposed method can be used to facilitate non-invasive or minimally invasive imaging with in-vivo and ex-vivo applications.