Introduction: The completion of an integrated PET/MR prototype system for brain imaging is the latest step in the evolution of positron emission tomography. Early images with this new imaging system demonstrate that high-resolution multiparametric studies can be combined without significant loss of performance of either imaging modality.
Objective: This new technology will make fusion of morphological and biological information much easier, yield real-time assessment of complementary variables and will provide dynamic information for kinetic modelling. Simultaneous acquisition of various metabolic and functional parameters may open new insights into the organization of the brain and its changes in disease.
Discussion: A new field may open up for molecular and cellular imaging, where new targets--e.g. angiogenesis, gene transfer, function and migration of transplanted cells--can be imaged in the morphological context and within a functional environment. This application might have a special impact on the translation of treatment concepts from experimental models into clinical application. If the added value of the hybrid system for diagnosis and treatment monitoring is established, a cost-effective PET/MR combination might attain wider clinical application.