Ultra-Short Echo Time Balanced SSFP for Highly Sensitive Detection & Quantification of Multi-Resonant 19F Imaging Agents for Targeted Molecular MRI

Jochen Keupp¹, Samuel A. Wickline², Gregory M. Lanza², Shelton D. Caruthers²

¹⁹F-MRI bears a high potential for molecular imaging allowing the direct quantification of targeted perfluoro-carbon nanoparticles (NP). Towards human translation, clinically-relevant compounds (safety, stability) like perfluoro-octyl-bromide (PFOB) should be used. But rich spectra and large chemical shifts add significant complexity. A combination of ultra-short echo time with a balanced SSFP pulse sequence enables highly sensitive detection of multi-resonant imaging labels like PFOB. During the FID readout of 0.6 ms, the PFOB-CF₂ line-group is recorded in constructive superposition. Sensitivity comparison to other ¹⁹F-MRI sequences like cartesian SSFP or fast-spin echo shows a superior performance of the novel sequence for PFOB imaging.