title: Highly undersampled supraaortic MRA at 3.0 T: initial results with parallel imaging in two directions using a 16-channel neurovascular coil and parallel imaging factors up to 16.
abstract: OBJECTIVE
  To present the feasibility of highly undersampled contrast-enhanced MRA (CE-MRA) of the supraaortic arteries with a 16-channel neurovascular coil at 3.0 T using parallel imaging in two directions with parallel imaging factors (PIF) up to 16.
  
  
  METHODS
  Institutional review board approval and informed consent were obtained. In a prospective study, MRA protocols including PIF of 1, 2, 4, 9 and 16 yielding a spatial resolution from 0.81×0.81×1.0 mm(3) to 0.46×.46×0.98 mm(3) were acquired. In 32 examinations, image quality and vascular segments were rated independently by two radiologists. SNR estimations were performed for all MRA protocols.
  
  
  RESULTS
  The use of high PIF allowed to shorten acquisition time from 2:09 min down to 1:13 min and to increase the anatomic coverage while maintaining or even increasing spatial resolution down to 0.46×0.46×0.98 mm(3). The larger anatomic coverage that was achieved with the use of high PIF allowed for visualization of vascular structures that were not covered by the standard protocols. Despite the resulting lower SNR using high PIF, image quality was constantly rated to be adequate for diagnosis or better in all cases.
  
  
  CONCLUSIONS
  The use of high PIF yielded diagnostic image quality and allowed to increase the anatomic coverage while maintaining or even improving spatial resolution and shortening the acquisition time.
authors.affiliation: Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany. guido.kukuk@ukb.uni-bonn.de
authors.forename: Guido M
authors.initials: GM
authors.lastname: Kukuk
authors.forename: Dariusch R
authors.initials: DR
authors.lastname: Hadizadeh
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gieseke
authors.forename: Marcus
authors.initials: M
authors.lastname: von Falkenhausen
authors.forename: Ingrid
authors.initials: I
authors.lastname: Böhm
authors.forename: Renate
authors.initials: R
authors.lastname: Semrau
authors.forename: Horst
authors.initials: H
authors.lastname: Urbach
authors.forename: Arne
authors.initials: A
authors.lastname: Koscielny
authors.forename: Frauke
authors.initials: F
authors.lastname: Verrel
authors.forename: Kai
authors.initials: K
authors.lastname: Wilhelm
authors.forename: Hans H
authors.initials: HH
authors.lastname: Schild
authors.forename: Winfried A
authors.initials: WA
authors.lastname: Willinek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D001158:Arteries / Q000473:pathology*; D003251:Constriction, Pathologic; D003287:Contrast Media / Q000494:pharmacology; D003952:Diagnostic Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D003287:Contrast Media