Simultaneous PET-MRI:: a new approach for functional and morphological imaging

Noninvasive imaging at the molecular level is an emerging field in biomedical research. This paper introduces a new technology synergizing two leading imaging methodologies: positron emission tomography ( PET) and magnetic resonance imaging ( MRI). Although the value of PET lies in its high- sensitivity tracking of biomarkers in vivo, it lacks resolving morphology. MRI has lower sensitivity, but produces high soft- tissue contrast and provides spectroscopic information and functional MRI ( fMRI). We have developed a three- dimensional animal PET scanner that is built into a 7- T MRI. Our evaluations show that both modalities preserve their functionality, even when operated isochronously. With this combined imaging system, we simultaneously acquired functional and morphological PET- MRI data from living mice. PET- MRI provides a powerful tool for studying biology and pathology in preclinical research and has great potential for clinical applications. Combining fMRI and spectroscopy with PET paves the way for a new perspective in molecular imaging.