Implementation of Shear Wave and Strain Elastography with Micro-Ultrasound

Quantitative tissue stiffness characterization can aid in diagnosing prostate cancer. Shear wave absolute vibro-elastography (S-WAVE) provides quantitative, multi-frequency shear wave imaging with external excitation, while strain elastography (SE) provides a map of relative tissue stiffness. In this work, we present a first-of-its-kind micro-ultrasound (microUS)-based system for prostate elastographic imaging. The system uses an ExactVu™ microUS with minimum hardware addition– making it compatible with the current clinical workflow. Bandpass sampling is utilized to effectively recreate phasors with a frame rate beneath the Nyquist sampling rate for tissue motion tracking in S-WAVE imaging. We characterize the methods (S-WAVE and SE) with a commercial quality assurance elasticity phantom having inclusions with different levels of stiffness. Promising results are achieved with both methods being able to identify all four inclusions with their expected contrast difference.