Three dimensional ultrasonic molecular imaging of angiogenesis

Ultrasonic (US) molecular imaging (MI) relies on microbubble contrast agents (MCAs) adhering to ligand-speciflc biomarkers for characterizing diseased tissue in applications such as tumor angiogenesis. One drawback to traditional 2D US MI methods is the inability to completely characterize the three dimensional (3D) in vivo environment. We attempt to improve targeted MCA visualization and quantification by performing US MI of tumors expressing α_vβ₃ in 3D space. 3D acquisitions were obtained on multiple rat fibrosarcoma tumors with a Siemens Sequoia system in CPS mode by mechanically scanning the transducer in the elevational direction across the tumor. Our US MI results show high targeting variability suggesting that individual 2D acquisitions can misrepresent more complex heterogeneous tissues. Our hypothesis is that 3D US MI will provide a more robust evaluation of disease progression than traditional methods.