The application of acoustic angiography to assess the progression of angiogenesis in a spontaneous mouse model of breast cancer

Acoustic angiography is a method for contrast enhanced ultrasound imaging that provides sufficient contrast and resolution to visualize microvasculature non-invasively. A dual-frequency transducer is used to transmit at low frequency and receive high frequency (superharmonic) echoes originating from intravascular microbubbles. Analysis of these images in healthy and tumor-bearing mice revealed that tumors possess quantifiably different vascular structure than healthy control animals, through measurements of vascular density and 2 metrics of tortuosity. Furthermore, tortuosity is correlated to proximity to the tumor margin, and distal tissue surrounding tumor regions has an intermediate level of tortuosity between that of tumor and control tissue. Overall, these results indicate that acoustic angiography images can reveal microvasculature in sufficient detail for vascular morphology to be used as a biomarker for cancer imaging.