Development of an optical elastomicroscopy for imaging tissue elasticity in high resolution

Articular cartilage is a thin but crucial tissue layer which plays an important role in diarthrodial joints. During the last decade, the quantitative ultrasound technique, especially the high frequency ultrasound elasticity measurement technique, called as ultrasound elastomicroscopy (UEM), has been widely employed as a versatile modality to investigate the articular cartilage. Ultrasound elastomicroscopy can measure the deformation of different layers of articular cartilage under compression, but whether the propagation of ultrasound in tissues was changed or not with the imposed load is still unknown. In this study, we developed a new optical method to validate the accuracy and reliability of the ultrasound elastomicroscopy. Layered sponge phantoms were prepared for the experiments. During the compression, both the ultrasound and optical elastomicroscopy systems were employed to record the ultrasound signals and optical images from inside and the font of the phantoms. The deformations of the phantoms from different layers were tracked from both ultrasound and optical signals and were then compared. The preliminary results suggest that the measurements of the ultrasound elastomicroscopy system could be validated.