title: Time-resolved three-dimensional magnetic resonance digital subtraction angiography without contrast material in the brain: Initial investigation.
abstract: OBJECTIVE
  To evaluate a novel magnetic resonance (MR) angiography (MRA) of three-dimensional (3D) MR digital subtraction angiography (MRDSA) without contrast material, which is essentially 3D true steady-state free precession (SSFP) with selected inversion recovery (IR) pulse using multiple cardiac phase acquisitions with a short increment delay in the assessment of normal cranial arteries, as a feasibility study before clinical use.
  
  
  METHODS
  Serial MRA images using 3D MRDSA without contrast material were acquired from 10 healthy volunteers. Visualization of normal cranial arteries with time-spatial labeling inversion pulse (Time-SLIP) MRDSA was qualitatively compared with the conventional MRA method, 3D time-of-flight (TOF)-MRA.
  
  
  RESULTS
  In all volunteers, serial 3D MRDSAs containing hemodynamic information were successfully imaged. The results of visualization of the branches of the cranial arteries with Time-SLIP MRDSA were comparable to those of 3D TOF-MRA. The mean scores +/- standard deviations for normal cerebral arteries (internal carotid arteries, middle cerebral arteries, anterior cerebral arteries, posterior cerebral arteries, and basilar arteries) were 2.4 +/- 0.5, 2.3 +/- 0.5, 2.0 +/- 0.7, 2.3 +/- 0.7, and 2.5 +/- 0.7, respectively.
  
  
  CONCLUSIONS
  Time-SLIP 3D MRDSA is a simple method for obtaining hemodynamic information. Although more MR sequence improvement is needed, it can play an important role in assessing cranial arteries without contrast material.
authors.affiliation: Department of Radiology, University of Yamanashi, Chuou, Yamanashi, Japan. masahori-tky@umin.ac.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hori
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shiraga
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Shigeki
authors.initials: S
authors.lastname: Aoki
authors.forename: Sachiko
authors.initials: S
authors.lastname: Isono
authors.forename: Masao
authors.initials: M
authors.lastname: Yui
authors.forename: Kuni
authors.initials: K
authors.lastname: Ohtomo
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
mesh_terms: D015901:Angiography, Digital Subtraction / Q000379:methods*; D001921:Brain / Q000033:anatomy & histology / Q000098:blood supply*; D002536:Cerebral Arteries / Q000033:anatomy & histology*; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D015588:Observer Variation; D012016:Reference Values