PET-MRI: a review of challenges and solutions in the development of integrated multimodality imaging.
MRI is the most flexible of our diagnostic imaging modalities, possessing the ability to characterize a wide range of parameters in the living subject and provide exquisite spatial resolution. Here we first review the rise of MRI to its current clinical "state-of-the-art" status and then consider the future directions for this technique. The long-term impact on clinical practice of recent innovations in MRI scanner hardware and sequence design are also considered. Key changes in clinical practice that we predict for the coming 10 years include: a widespread shift to higher field imaging (3T); further improvements in MRI coil technology, including further increases in the number of channels; the introduction of ultra-short echo-time imaging; the introduction of combined modality methods (e.g. positron emission tomography (PET)-MRI and single photon emission CT (SPECT)-MRI); and significant advances in molecular MRI agents. Even after 30 years of continuing developments in human MRI, the coming decade will provide further major advances in diagnostic MRI.