title: 19F MR imaging golden angle-based capsule tracking for intestinal transit and catheter tracking: initial in vivo experience.
abstract: OBJECTIVE
  To combine fluorine 19 ((19)F) magnetic resonance (MR) imaging and golden angle radial acquisition and to assess the feasibility of (19)F MR imaging golden angle-based tracking for catheter tracking applications and simultaneous three-dimensional (3D) intestinal tracking of ingested (19)F-labeled capsules in vivo.
  
  
  METHODS
  Approval from the local ethical committee and informed consent from the subject were obtained. In vitro studies were performed to assess (19)F MR imaging golden angle-based tracking reliability with regard to temporal resolution and different tracking strategies (boundary condition-free tracking, composite image-based tracking, and model-based tracking). In vivo performance of the method was investigated in one healthy volunteer on 2 days. On study day 1, a duodenal catheter incorporating five (19)F-labeled capsules was administered nasally, and its 3D movement was tracked inside the stomach and esophagus. On study day 2, three (19)F-labeled capsules were swallowed, and intestinal movement was tracked.
  
  
  RESULTS
  Simultaneous in vivo 3D tracking of multiple (19)F-labeled capsules was successfully performed without incorporation of boundary conditions at a temporal resolution of 252 msec. Incorporation of boundary conditions with composite image-based tracking and model-based tracking increased tracking reliability and enabled temporal resolution as high as 108 msec.
  
  
  CONCLUSIONS
  Use of (19)F MR imaging golden angle-based capsule tracking enables in vivo tracking of (19)F-labeled capsules and catheters at high temporal resolution. The presented method is applicable to physioanatomic studies of the gastrointestinal tract and shows potential for real-time tracking in interventional radiology.
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.
authors.forename: Tobias
authors.initials: T
authors.lastname: Hahn
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kozerke
authors.forename: Werner
authors.initials: W
authors.lastname: Schwizer
authors.forename: Michael
authors.initials: M
authors.lastname: Fried
authors.forename: Peter
authors.initials: P
authors.lastname: Boesiger
authors.forename: Andreas
authors.initials: A
authors.lastname: Steingoetter
mesh_terms: D000465:Algorithms; D002214:Capsules; D002404:Catheterization; D020099:Coated Materials, Biocompatible; D043844:Crown Ethers; D005240:Feasibility Studies; D005466:Fluorocarbons; D005769:Gastrointestinal Motility / Q000502:physiology*; D005772:Gastrointestinal Transit / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio
chemical_list: D002214:Capsules; D020099:Coated Materials, Biocompatible; D043844:Crown Ethers; D005466:Fluorocarbons; C089317:perfluoro-15-crown-5-ether; C003005:hexafluorobenzene