[Sub-specialization within the field of radiology].

Medical knowledge and skills are accumulating at an ever increasing speed. Therefore, it becomes more and more difficult for a single one to have a complete overview of a whole discipline. This general observation also applies for radiology. Radiology has to cooperate with almost all medical disciplines and has to provide competent experts. It is therefore mandatory to support differentiation within the field of radiology and at the same time to save coherence and future developments.