12B-1 Detectability of Small Blood Vessels Using High-Frequency Power Doppler Ultrasound

Power Doppler imaging of physiological and pathological angiogenesis can be challenging given the presence of small blood vessels and slow flow velocities. Images can be plagued with false-positive color pixels or undetected vessels, thereby complicating the interpretation of vascularity metrics. This paper presents studies of blood vessel detectability using flow phantoms with various combinations of vessel size (160, 200, 250, 300, and 360 mum), flow velocity (4, 3, 2, 1, and 0.5 mm/s), and transducer frequency (30 and 40 MHz), while varying the wall filter cut-off velocity. Receiver operating characteristic (ROC) curves and areas under ROC curves indicate that good vessel detection performance can be achieved with a 40-MHz transducer for flow velocities ges 2 mm/s and with a 30-MHz transducer for flow velocities ges 1 mm/s.