title: Time-resolved TOF MR angiography in mice using a prospective 3D radial double golden angle approach.
abstract: OBJECTIVE
  To develop an undersampled anatomical, three-dimensional (3-D) time-resolved magnetic resonance angiography (MRA) method for small animals based on time-of-flight (TOF) effect and radial sampling.
  
  
  METHODS
  Mouse carotid arteries and Circle of Willis images were acquired on a 7T scanner with an electrocardiogram (ECG)-triggered sequence. Preliminary experiments were used to generate an approximately uniform distribution of radial projections with a first golden angle and to produce anatomical TOF images. A second golden angle ratio between consecutive projections of cine acquisitions was added to make it possible to use a temporal filter during reconstruction of time-resolved angiography. A decreasing number of projections were tested, and their impact on signal-to-noise ratio (SNR) and spatial resolution was assessed.
  
  
  RESULTS
  In anatomical MRA, the undersampled radial approach efficiently allows fast acquisition of mouse angiogram in 3D (22 sec). It was also only slightly sensitive to motion and flow artifacts. The time-resolved sequence can be performed with only 2,500 projections per cine and a temporal resolution under 4 ms in a relatively short acquisition time (less than 5 min).
  
  
  CONCLUSIONS
  This technique simultaneously provided high 3D isotropic spatial resolution and excellent temporal resolution with a good SNR level, allowing blood flow to be visualized in a restricted acquisition time.
authors.affiliation: Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université Bordeaux Segalen, Bordeaux Cedex, France.
authors.forename: Aurelien J
authors.initials: AJ
authors.lastname: Trotier
authors.forename: William
authors.initials: W
authors.lastname: Lefrançois
authors.forename: Emeline J
authors.initials: EJ
authors.lastname: Ribot
authors.forename: Eric
authors.initials: E
authors.lastname: Thiaudiere
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Franconi
authors.forename: Sylvain
authors.initials: S
authors.lastname: Miraux
mesh_terms: D000465:Algorithms; D000818:Animals; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods; D002339:Carotid Arteries / Q000033:anatomy & histology*; D002941:Circle of Willis / Q000033:anatomy & histology*; D003627:Data Interpretation, Statistical; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D015233:Models, Statistical; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio
keywords: 3D radial; TOF angiography; golden angle; small animals; temporal filter; time-resolved