PET/MRI: a new technology in the field of molecular imaging.

BACKGROUND: The introduction of the new simultaneous PET/MRI scanner opens new opportunities in functional imaging. SOURCES OF DATA: This article is based on the literature review and our personal experience of the first simultaneous PET/MRI scanner in the UK. AREAS OF AGREEMENT: PET/CT is well established and a key component of management guidance in a range of diseases. MRI has superior soft tissue resolution, which is useful in the evaluation of many diseases. AREAS OF CONTROVERSY: There are currently no guidelines regarding clinical use of PET/MRI, and those centres with a PET/MRI facility are undertaking research to look for a 'key application'. GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH: This review briefly describes some of the technical advances, present comparisons with the diagnostic performance of current imaging modalities (PET/CT and MRI) and identifies potential indications and research directions.