When stem cell-derived alveolar-like macrophages (ALMs) are labeled with perfluoropolyether (PFPE), they can potentially be monitored and tracked longitudinally in vivo using 19F MRI. In this work, different concentrations of PFPE and 5 million PFPE-labeled ALMs were imaged in vitro using 19F MRI at 3T. The results demonstrated the feasibility of detecting a small number of PFPE-labeled ALMs. This work will provide guidance for the upcoming in vivo instillation experiments in rat lungs. Longitudinal in vivo studies will further aid ALMs to be clinically translated as a stem cell therapy to treat chronic lung diseases.