A novel Sensitivity Index from the Flow Velocity Variation in Quality Control for PW Doppler: a preliminary study

In recent years, the scientific community highlighted how the combination of the progressive evolution of the Ultrasound (US) technologies and the difficulties in retrieving a fixed number of Quality Control (QC) parameters to assess US equipment performance represents a burden in the definition of a shared worldwide standard. Consequently, this preliminary study introduces and investigates a novel parameter for Pulsed Wave (PW) Doppler QC, namely the Average Maximum Velocity Sensitivity (AMVS). The mathematical expression of the parameter hereby presented has a differential nature that prevents AMVS from being dependent on the insonification angle, which is a commonly accepted systematic error source for the accuracy in the PW Doppler maximum velocity estimation. Data have been acquired from three US systems of intermediate technology level, each one equipped with a phased array US probe. Tests have been performed with two different US system settings and two constant flow rate regimes set on a Doppler flow phantom. Despite the limitations encountered, from the results AMVS emerged as a promising parameter for the assessment of US sensitivity. Therefore, further studies are going to be conducted with different Doppler phantom models, on a higher number of US diagnostic systems and probes.