F MRI of Fibroblasts and Neuroblastoma cells labeled with emulsified Perfluoro-15-Crown-5 Ether

Introduction: F-labelled cells provide an important new technique to evaluate in vivo the migration of implanted cells such as in stem cell therapy [1]. F-marker substances such as perfluorocarbons (PFC ) have been used for cell tracking based on F spectroscopy [2]as well as F magnetic resonance imaging (MRI). We present first results of F MRI of fibroblasts and neuroblastoma cells labeled with a perfluoro-15crown-5-ether (PFCE; ABCR-GmbH/Germany) emulsion [3,4]. The efficacy of the labelling compounds is mainly dependent on the composition and number of fluorine atoms. Often fluorine compunds exhibit strong chemical shifts reducing the sensitivity as well as introducing additional artifacts in MRI. In contrast PFCE has 20 chemically equivalent fluorine atoms. The F spectrum therefore presents a single narrow resonance enabling imaging applications with a high sensitivity but without chemical shift artefacts [5]. To ease the transfection of the cells PFCE was applied as an emulsion.