PET/MRI: challenges, solutions and perspectives

Z Med Phys. 2012 Dec;22(4):281-98. doi: 10.1016/j.zemedi.2012.07.003. Epub 2012 Aug 25.


Already from the start of PET/CT integrating positron emission tomography (PET) and computed tomography (CT) in one instrument, there have been considerations how to combine PET and magnetic resonance imaging (MRI) so that their complementary abilities can be utilized in a single investigation. Since classical PET electronics fail in an even weak magnetic field and PET signal processing might disturb high-frequency signals of MRI, it soon became clear that new solutions had to be found to avoid mutual interferences. During the last fifteen years a number of different approaches towards PET/MRI for small animal imaging have been developed by research groups which together with their specific features are summarized in this review. Recently, PET/MRI for human imaging became available as well - this time by industrial initiatives. First some prototypes of BrainPET/MRI were developed followed by commercial products for simultaneous and non-simultaneous whole-body PET/MRI. Although only PET/MRI integrated in one scanner offers the full diversity of complementary multiparametric imaging, there are also promising applications of non-simultaneous sequential PET/MRI. While describing the present instrumentation for human PET/MRI, this review discusses the challenges and promises related to this new imaging technology.

MeSH terms

  • Alzheimer Disease / diagnosis
  • Alzheimer Disease / pathology
  • Animals
  • Brain / pathology
  • Carbon Radioisotopes
  • Contrast Media / administration & dosage
  • Diffusion Magnetic Resonance Imaging / instrumentation
  • Diffusion Magnetic Resonance Imaging / methods
  • Efficiency
  • Electron Spin Resonance Spectroscopy / instrumentation
  • Electron Spin Resonance Spectroscopy / methods
  • Equipment Design
  • Fluorodeoxyglucose F18
  • Hodgkin Disease / diagnosis
  • Hodgkin Disease / pathology
  • Humans
  • Image Enhancement / instrumentation*
  • Image Enhancement / methods*
  • Image Interpretation, Computer-Assisted / instrumentation*
  • Image Interpretation, Computer-Assisted / methods*
  • Magnetic Resonance Imaging / instrumentation
  • Magnetic Resonance Imaging / methods*
  • Models, Animal
  • Multimodal Imaging / instrumentation
  • Multimodal Imaging / methods
  • Positron-Emission Tomography / instrumentation*
  • Positron-Emission Tomography / methods*
  • Raclopride
  • Rats
  • Sensitivity and Specificity
  • Software
  • Tomography, X-Ray Computed
  • Whole Body Imaging / instrumentation
  • Whole Body Imaging / methods
  • Young Adult


  • Carbon Radioisotopes
  • Contrast Media
  • Fluorodeoxyglucose F18
  • Raclopride