title: PET/MR images acquired with a compact MR-compatible PET detector in a 7-T magnet.
abstract: OBJECTIVE
  To prospectively use compact avalanche photodiodes instead of photomultiplier tubes to integrate a positron emission tomographic (PET) detector and a 7-T magnetic resonance (MR) imager.
  
  
  METHODS
  All animal experiments were performed in accordance with the University of Tübingen guidelines and the German law for the protection of animals. A compact lutetium oxyorthosilicate-avalanche photodiode PET detector was built and optimized to operate within a 7-T MR imager. The detector performance was investigated both outside and inside the magnet, and MR image quality was evaluated with and without the PET detector. Two PET detectors were set up opposite each other and operated in coincidence to acquire PET images in the step-and-shoot mode in a mouse head specimen after injection of fluorine 18 fluorodeoxyglucose.
  
  
  RESULTS
  The performance of the PET detector when operated inside the magnet during MR image acquisition showed little degradation in energy resolution (increase from 14.6% to 15.9%). The PET detector did not influence MR imaging. The fused PET and MR images showed an anatomic match and no degradation of image quality.
  
  
  CONCLUSIONS
  Simultaneous PET and MR imaging with a 7-T system was deemed feasible.
authors: Laboratory for Preclinical Imaging and Imaging Technology, Clinic of Radiology, University of Tübingen, Röntgenweg 13, 72076 Tübingen, Germany.
authors: Martin S
authors: MS
authors: Judenhofer
authors: Ciprian
authors: C
authors: Catana
authors: Brian K
authors: BK
authors: Swann
authors: Stefan B
authors: SB
authors: Siegel
authors: Wulf-Ingo
authors: WI
authors: Jung
authors: Robert E
authors: RE
authors: Nutt
authors: Simon R
authors: SR
authors: Cherry
authors: Claus D
authors: CD
authors: Claussen
authors: Bernd J
authors: BJ
authors: Pichler
mesh_terms: D000818:Animals; D004867:Equipment Design; D005240:Feasibility Studies; D019788:Fluorodeoxyglucose F18; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D051379:Mice; D049268:Positron-Emission Tomography / Q000295:instrumentation*; D011446:Prospective Studies; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18