[Application of MR/PET in oncologic imaging]

The present review aims to depict the possibilities offered by hybrid imaging with magnetic resonance positron emission tomography (MR/PET). Recently, new whole-body MR/PET scanners were introduced allowing for the combination of both modalities outside the brain. This is a challenge for both modalities: For MRI, it is essential to provide anatomical images with high resolution. Additionally, diffusion-weighted imaging (DWI), proton spectroscopy, but also dynamic contrast-enhanced imaging plays an important role. With regard to PET, the technical challenge mainly consists of obtaining an appropriate MR-based attenuation correction for the PET data. Using MR/PET, it is possible to acquire morphological and functional data in one examination. In particular, children and young adults will benefit from this new hybrid technique, especially in oncologic imaging with multiple follow-up examinations. However, it is expected that PET/CT will not be replaced completely by MR/PET because PET/CT is less cost-intensive and more widely available. Moreover, in lung imaging, MRI limitations still have to be accepted. Concerning research, simultaneous MR/PET offers a variety of new possibilities, for example cardiac imaging, functional brain studies or the evaluation of new tracers in correlation with specific MR techniques.