title: Real-time multipoint gastrointestinal 19-fluorine catheter tracking.
abstract: OBJECTIVE
  To develop MR based real-time gastrointestinal 19-Fluorine (19F) catheter tracking and visualization allowing for real-time detection and feedback of 3D catheter shape and movement as well as catheter-driven adjustments of 1H imaging geometry parameters.
  
  
  METHODS
  Data were acquired on a 3T clinical system using 3D Golden Angle radial sampling. Two gastrointestinal catheters incorporating four fiducial 19F markers (65 or 50 µL marker volume) were tracked while being pulled through a gel phantom by an operator inside the MR room with velocities of 2-18 mm/s. During continuous acquisition, k-space profiles were transferred in real-time to an external computer for concurrent reconstruction of 3D 19F images and detection and visualization of marker positions. Based on αthe marker positions, automatic adjustments of 1H imaging planes to facilitate targeted anatomical scanning was implemented.
  
  
  RESULTS
  Mean tracking reliabilities were 94.5 and 83.6% (catheters 1 and 2) for temporal resolutions 185-740 ms. Reconstruction times of 196 ms were achieved. Real-time visual feedback allowed the operator to accurately control the catheter movement. Catheter-guidance for 1H imaging was reliable.
  
  
  CONCLUSIONS
  The presented real-time 19F MR based framework for the tracking of 19F labeled devices is applicable to combined 19F and 1H MRI guidance of gastrointestinal devices in vivo.
authors: Institute for Biomedical Engineering, University and ETH Zurich, Switzerland.
authors: Tobias
authors: T
authors: Hahn
authors: Sebastian
authors: S
authors: Kozerke
authors: Werner
authors: W
authors: Schwizer
authors: Michael
authors: M
authors: Fried
authors: Peter
authors: P
authors: Boesiger
authors: Andreas
authors: A
authors: Steingoetter
mesh_terms: D002404:Catheterization / Q000379:methods*; D003199:Computer Systems; D003287:Contrast Media; D005461:Fluorine; D041981:Gastrointestinal Tract / Q000033:anatomy & histology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D053783:Magnetic Resonance Imaging, Interventional / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D005461:Fluorine
keywords: 19F; MRI; catheter; interventional; tracking