title: Magnetic resonance phase contrast velocity measurement for non-invasive follow up after percutaneous transluminal angioplasty.
abstract: BACKGROUND
  The aim of this study was to evaluate magnetic resonance phase contrast velocimetry (MRVL) as a non-invasive follow up tool to assess restenosis after percutaneous transluminal angioplasty (PTA).
  
  
  METHODS
  We prospectively investigated 51 consecutive patients who underwent PTA of the femoropopliteal region. MRVL was conducted prior, one day, six weeks, twelve weeks and 24 weeks after PTA using a circular polarized extremity coil and a gradient echo sequence (TR/TE 600/6 ms, flip angel 30 degrees, slice thickness 10 mm). Hemodynamic data, derived from the MR phase contrast sequence, allowed to calculate the degree of area stenosis of the lesion treated with PTA. These data were correlated with clinical hemodynamic parameters (ankle-brachial index and walking distance).
  
  
  RESULTS
  The mean grade of area stenosis was 69% +/- 27% before PTA, 30% +/- 20% one day, 29% +/- 23% six weeks, 39% +/- 17% twelve weeks and 42% +/- 18% 24 weeks after PTA and correlated well with clinical data and the post angioplasty clinical course of the patients.
  
  
  CONCLUSIONS
  Follow up measurements using MRVL are suitable to assess restenosis after PTA and allow quantifying the grade of recurrent stenosis as well as the hemodynamic consequences.
authors.affiliation: Department of Diagnostic Radiology, University Hospital, Philipps University, Marburg, Germany.
authors.forename: J T
authors.initials: JT
authors.lastname: Heverhagen
authors.forename: H J
authors.initials: HJ
authors.lastname: Wagner
authors.forename: D
authors.initials: D
authors.lastname: Bandorski
authors.forename: M
authors.initials: M
authors.lastname: Hoppe
authors.forename: H
authors.initials: H
authors.lastname: Alfke
mesh_terms: D000368:Aged; D000800:Angioplasty, Balloon / Q000379:methods*; D001157:Arterial Occlusive Diseases / Q000175:diagnosis / Q000628:therapy*; D001783:Blood Flow Velocity / Q000502:physiology*; D005260:Female; D005263:Femoral Artery / Q000473:pathology / Q000503:physiopathology; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007383:Intermittent Claudication / Q000175:diagnosis / Q000628:therapy*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011150:Popliteal Artery / Q000473:pathology / Q000503:physiopathology; D011446:Prospective Studies; D012008:Recurrence; D012680:Sensitivity and Specificity; D012984:Software