title: Nonenhanced ECG-gated time-resolved 4D steady-state free precession (SSFP) MR angiography (MRA) for assessment of cerebral collateral flow: comparison with digital subtraction angiography (DSA).
abstract: OBJECTIVE
  To evaluate a nonenhanced time-resolved 4D SSFP MRA for dynamic visualization of intracranial collateral blood flow.
  
  
  METHODS
  22 patients (59.0 ± 11.8 years) with steno-occlusive disease of brain-supplying arteries were included in this study. 4D SSFP MRA of the intracranial arteries was acquired with 15 temporal phases and a temporal resolution of 115 ms using 1.5 T MR. Cerebral DSA served as the reference standard and was available in all patients.
  
  
  RESULTS
  Nonenhanced 4D SSFP MRA allowed for detailed dynamic visualization of blood flow in the circle of Willis and its branches in 21 of 22 (95.5%) patients. Collateral flow was excluded with both 4D SSFP MRA and DSA in 4 patients. In 17 patients, DSA detected anterior collateral flow (n = 8), posterior collateral flow via the right (n = 8) and left (n = 7) posterior communicating artery as well as patent EC-IC bypasses (n = 8). 29 of 31 collateral flow pathways were visualized by 4D SSFP MRA. As compared to DSA, 4D SSFP MRA showed a high sensitivity (92.3%), specificity (100%), positive predictive value (100%) and negative predictive value (95.2%) for visualization of intracranial collateral flow.
  
  
  CONCLUSIONS
  4D SSFP MRA is a promising non-invasive imaging technique for dynamic visualization of intracranial collateral flow.
authors.affiliation: Department of Radiology, University Hospital Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Germany. rotemshlomo@yahoo.de
authors.forename: Rotem Shlomo
authors.initials: RS
authors.lastname: Lanzman
authors.forename: Patric
authors.initials: P
authors.lastname: Kröpil
authors.forename: Peter
authors.initials: P
authors.lastname: Schmitt
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Bi
authors.forename: Michael
authors.initials: M
authors.lastname: Gliem
authors.forename: Falk R
authors.initials: FR
authors.lastname: Miese
authors.forename: Daniel
authors.initials: D
authors.lastname: Hänggi
authors.forename: Marcel
authors.initials: M
authors.lastname: Kamp
authors.forename: Axel
authors.initials: A
authors.lastname: Scherer
authors.forename: Bernd
authors.initials: B
authors.lastname: Turowski
authors.forename: Dirk
authors.initials: D
authors.lastname: Blondin
mesh_terms: D015901:Angiography, Digital Subtraction / Q000379:methods*; D001783:Blood Flow Velocity; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D002560:Cerebrovascular Circulation; D002941:Circle of Willis / Q000503:physiopathology*; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D007089:Image Enhancement; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity