PET/MRI in infectious and inflammatory diseases: will it be a useful improvement?

The knowledge of disease mechanisms and the identification of markers of disease development and progression, and for therapy evaluation, are rapidly expanding. Early diagnosis, possible disease prevention and individual therapy stratification are important goals in health care. Nuclear medicine and radiology are potentially able to satisfy these increasing demands for diagnosis, prevention, pathophysiological understanding and treatment possibilities. An increasing number of biomarkers, drugs, antibodies and peptides, contrast agents and MRI sequences have also been developed for these purposes. Together with this continuing search for the "holy grail" radiopharmaceutical, the use of hybrid imaging is another important development in the field. A recent development in hybrid cameras is the introduction of combined PET and MRI. Despite the intriguing novelty, it is important to evaluate carefully, in a cost-benefit manner, the possible advantages and clinical applications of such an expensive tool.