High-frequency ultrasound imaging of targeted-microbubbles detects tumor vessel hypoxia.

Representative image and quantified data of anti-pimonidazole labeled microbubbles (MBα-pimo) bound in perfused hypoxic tumor vasculature without pimonidazole injection (A), and with pimonidazole injection (B) in 4T1 tumor bearing mice. Top image shows the signal before the burst sequence and the bottom image shows after the burst sequence (A, B). (C) Quantified data of different experimental conditions using targeting and non-targeting microbubbles (as indicated). D) Summary of quantitated data statistically analyzed represented as mean ± SEM, ^#p < 0.05, versus non-targeting MB, MBα-pimo without pimonidazole injection, and MBα-pimo in muscle tissue (ANOVA post-hoc Holm-Sidak).