title: PET/MRI system design.
abstract: BACKGROUND
  The combination of clinical MRI and PET systems has received increased attention in recent years. In contrast to currently used PET/CT systems, PET/MRI offers not only improved soft-tissue contrast and reduced levels of ionizing radiation, but also a wealth of MRI-specific information such as functional, spectroscopic and diffusion tensor imaging. Combining PET and MRI, however, has proven to be very challenging, due to the detrimental cross-talk effects between the two systems.
  
  
  OBJECTIVE
  Significant progress has been made in the recent years to overcome these difficulties, with several groups reporting PET/MRI prototypes for animal imaging and a clinical insert for neurological applications being demonstrated at the 2007 Annual Meeting of the Society of Nuclear Medicine.
  
  
  CONCLUSIONS
  In this paper we review different architectures for clinical PET/MRI systems, and their possibilities, limitations and technological obstacles.
authors.affiliation: Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaniger Str. 22, 81675, Munich, Germany. gaspar.delso@tum.de
authors.forename: Gaspar
authors.initials: G
authors.lastname: Delso
authors.forename: Sibylle
authors.initials: S
authors.lastname: Ziegler
mesh_terms: D000818:Animals; D004867:Equipment Design; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D049268:Positron-Emission Tomography / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors