Analysis of High-Lateral-Resolution Imaging Using Thin Quartz Fibers as Transmission Lines

As a quantitative imaging tool for ultrasonic endoscopy with high lateral resolution, we proposed a new measurement method for tissue acoustic impedance utilizing the adjacent near-field at one end of a quartz fiber. In this note, the fine prospect for matching layer design at a fiber end with a diameter less than wavelength of ultrasound transmitted into a tissue medium is reported. Real-time simulations by the three dimensional finite element method ensure that the shear wave propagation is dominant in the matching layer, and the reflection coefficient obtained from echoes at the matching frequency is very sensitive for the evaluation of tissue acoustic impedance.