Fast Spectroscopic Imaging (F-uTSI) of Angiogenesis on Vx-2 Tumors in Rabbits Using Targeted Perfluorocarbon Emulsions

Quantitative molecular MR imaging of angiogenesis may fulfill an unmet clinical need for patient stratification by increasing efficacy of antiangiogenic therapy. In particular, perfluorocarbons targeted to αvβ3 have been used to image angiogenesis through paramagnetic markers and also direct detection by F MR imaging or spectroscopy [1,2,3]. F offers several advantages including absolute quantification, high intrinsic specificity, and no need for pre-contrast imaging. However, one of the major drawbacks of more clinically relevant F compounds is the large chemical shift dispersion of the multiple resonances. If imaged by a gradient or spin echo technique, the resulting images will display a large chemical shift artifact in both the read-out direction and the slice selection direction. Fluorine ultra-fast Turbo Spectroscopic Imaging (F-uTSI) has been developed to overcome these drawbacks, without sacrificing sensitivity [4,5]. Additionally F-uTSI offers, without increasing scan time, the advantage of distinguishing various F compounds based on chemical shift differences allowing for ‘multi-color’ imaging. Beyond the preliminary, non-targeted in vivo results already shown, herein we demonstrate with in vivo tumor models the sensitive detection of angiogenesis with the F-uTSI technique.