Tunable imaging of cells labeled with MRI-PARACEST agents

Cell-tracking experiments by MRI are possible with a novel class of Tb and Eu paramagnetic imaging agents, with which contrast is generated upon irradiation at a specific frequency (see picture). Middle: A) unlabeled; B) Tb-labeled; C) Eu-labeled; D) Tb- and Eu-labeled cells. Left: irradiation at ±180 kHz (Tb-agent-specific). Right: irradiation at ±15 kHz (Eu-agent-specific).