title: Magnetic resonance angiography of the carotid arteries: comparison of unenhanced and contrast enhanced techniques.
abstract: OBJECTIVE
  To compare different techniques for carotid imaging including contrast-enhanced, unenhanced and dynamic techniques to find an alternative to contrast-enhanced MRA.
  
  
  METHODS
  43 patients referred for imaging of the carotids were enrolled in this IRB-approved study. Imaging included dark-blood, time-of-flight, ECG-gated SSFP and dynamic and static contrast-enhanced MRA. Two radiologists evaluated all datasets in terms of image quality (vessel lumen, signal homogeneity, diagnostic confidence, preferred technique) on a four-point Likert-scale and in measuring the vessel area.
  
  
  RESULTS
  Of the 43 included patients the first 8 subjects served for protocol optimisation and 4 individuals discontinued the examination. Thus 31 datasets served for evaluation. CE-MRA revealed best results for delineation of vessel lumen, signal homogeneity and diagnostic confidence with values of 3.61, 3.42 and 3.77. It was also rated as the most preferred technique. SSFP-MRA was rated second in all categories with values of 3.1, 2.9 and 3.11. This unenhanced technique was the only one showing non-significantly different results in quantitative analysis.
  
  
  CONCLUSIONS
  SSFP-MRA, an unenhanced form of MRA, represents an alternative to CE-MRA, particularly in patients where administration of gadolinium for CE-MRA may be contraindicated. In contrast to other techniques, SSFP-MRA serves with not significant different results compared to standard CE-MRA.
authors.affiliation: Department of Clinical Radiology, University Hospitals Munich-Grosshadern Campus, Ludwig Maximilians University, Marchioninistr. 15, 81377 Munich, Germany. harald.kramer@med.lmu.de
authors.forename: Harald
authors.initials: H
authors.lastname: Kramer
authors.forename: Val M
authors.initials: VM
authors.lastname: Runge
authors.forename: John N
authors.initials: JN
authors.lastname: Morelli
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Williams
authors.forename: L Gill
authors.initials: LG
authors.lastname: Naul
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Bernd J
authors.initials: BJ
authors.lastname: Wintersperger
mesh_terms: D000704:Analysis of Variance; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000473:pathology; D003287:Contrast Media; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D008875:Middle Aged; D009942:Organometallic Compounds; D011446:Prospective Studies
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine