Three-dimensional quantitative elastography using micro-ultrasound: Proof of concept

Prostate cancer (PCa) is one of the most frequently diagnosed cancers worldwide, yet there are still limitations to overcome in its diagnostic workflow. Some of these limitations may be addressed by quantitative elastography and micro-ultrasound (microUS). This paper presents the first implementation of volumetric shear wave absolute vibro-elastography (S-WAVE) using the ExactVu™ microUS system. This implementation uses minimal additional hardware, making it conducive to insertion into the clinical workflow. In order to accurately recreate phasors with a frame rate below the Nyquist sampling rate for the excitation frequencies, a bandpass sampling strategy is employed for tissue motion tracing. This method is validated using a commercial quality assurance phantom, with inclusions of varying stiffness levels within a homogeneous background. All four inclusions could be visualized with the expected relative stiffness values, and the background stiffness could be measured repeatedly. This demonstrates the effectiveness of microUS-based S-WAVE imaging for the future detection of PCa lesions.