He received his Master's Degree and Ph.D. in Medical Physics from the University of Wisconsin–Madison in 1979 and in 1988 he completed his Habilitation in Medical Physics at the University of Tübingen.
During the period 1979 to 1995 he worked in the research laboratories of Siemens Medical Systems in Erlangen, Germany, from 1988 to 1995 as head of the department of Medical Physics. Since 1991 he has been Adjunct Associate Professor of Medical Physics at the University of Wisconsin, from 1993 to 1995 he lectured at the Technical University of Munich. In 1995 he was appointed full professor and director of the newly established Institute of Medical Physics at the Friedrich-Alexander-University, Erlangen-Nuremberg, Germany.
His main research interests is in medical imaging, the development and introduction of helical scan CT was a particular focus. He has also worked in radiation protection and the development of quantitative diagnostic procedures, e.g. for assessment of osteoporosis, lung and cardiac diseases.
As of 2006[update] he has published more than 670 scientific papers.