Ultra-Short Echo Time 19F/1H Imaging of Gadolinium-Free Perfluoro-Carbon Nanoparticles: A Robust Method for in Vivo Angiogenesis Imaging

Jochen Keupp¹, Anne H. Schmieder², Todd A. Williams², J. S. Allen², Samuel A. Wickline², Gregory M. Lanza², Shelton D. Caruthers²

Molecular imaging of integrin-targeted theranostic nanoparticles (NP) may offer profound impact on anti-angiogenic therapy. Previously, the value of α_νβ3-targeted nanoparticles (NP) with large payloads of Gd has been shown. This work presents a novel ¹⁹F pulse sequence to image clinically-relevant perfluoro-octyl-bromide (PFOB) NP without Gd. Using ¹⁹F/¹H radial 3D balanced UTE-SSFP sequence, angiogenesis is imaged in a rabbit Vx2 cancer model comparing α_νβ3-targeted PFOB-NP with and without Gd. The new sequence is shown to allow robust, sensitive in vivo visualization of cancer-related neovasculature despite the complex resonant peak structure and the extended T1-relaxation time of Gd-free NP.