Dr Karl-Josef Langen is nuclear medicine physician focused on preclinical and clinical testing of new radiopharmaceuticals for nuclear medicine diagnostics. He qualified at RWTH Aachen university clinic in 1985 and completed training in nuclear medicine at the University of Düsseldorf in 1989. After habilitation in nuclear medicine in 1992 he became head of a research group at the Research Center Jülich (FZJ) focusing on SPECT/PET and correlative MR-PET imaging of brain tumors including Hybrid-PET-MRI. In 2013 he was appointed professor and senior physician of the Department of Clinical and Experimental Nuclear Medicine at the RWTH Aachen University at the research center Jülich.