Small-diameter Vasculature Detection with Coherent Flow Power Doppler Imaging

Power Doppler (PD) imaging is a widely used technique for flow detection in clinics, and is utilized as an adjunct tool for prenatal/placental vessel evaluation. However, the sensitivity of PD in small vessel detection is limited by the small-diameter and slow flow of the placental vasculature, where abnormalities are indicative of disorders including preeclampsia, fetal growth restriction, and early pregnancy loss. In order to provide more sensitive detection of placental vasculature, a coherent flow imaging technique, termed coherent flow power Doppler (CFPD), is characterized and evaluated with both simulation and flow-phantom experiment studies. The results from both studies suggest that CFPD is able to provide 15-25 dB increase in the signal-to-noise ratio (SNR) of Doppler images. Due to the increase in SNR, CFPD is able to detect small vessels in high channel noise cases, for which PD was unable to generate enough contrast on the vessel. Such cases are not uncommon among people with high body mass index. The results indicate that the CFPD method is a promising candidate for small vessel imaging.