title: 7 Tesla MPRAGE imaging of the intracranial arterial vasculature: nonenhanced versus contrast-enhanced.
abstract: OBJECTIVE
  To intraindividually compare the delineation of intracranial arterial vasculature in nonenhanced versus contrast-enhanced magnetization prepared rapid gradient echo (MPRAGE) imaging at 7 Tesla (T).
  
  
  METHODS
  Sixteen subjects were examined on a 7 T whole-body magnetic resonance system (Magnetom 7T) equipped with a 32-channel transmit/receive head coil. MPRAGE imaging was performed pre- and postcontrast after the application of 0.1 mmol/kg bodyweight gadobutrol. For qualitative analysis, the delineation of the intracranial arteries, overall image quality, and image impairment were assessed in the nonenhanced and contrast-enhanced datasets using a 5-point scale (5 = excellent to 1 = nondiagnostic). Additionally, contrast ratios (CR) of the middle cerebral artery in correlation to surrounding gray matter in nonenhanced and postcontrast images were obtained. For statistical analysis a Wilcoxon signed-rank test was applied.
  
  
  RESULTS
  Nonenhanced MPRAGE imaging offered an excellent delineation of the central vessel segments of the anterior circulation (mean anterior circulation 4.6) and a moderate- to high-quality assessment of the vessels of the posterior circulation (mean posterior circulation 3.9). Vessel delineation was improved in all assessed segments in the contrast-enhanced datasets, except for the cavernous segment of the internal carotid artery. Quantitative analysis revealed a mild, nonsignificant increase in CR mean values of the M1 segment (CRnonenhanced 0.67; CRcontrast-enhanced 0.69).
  
  
  CONCLUSIONS
  Our results demonstrate the high diagnostic value of nonenhanced 7 T MPRAGE imaging for the assessment of the intracranial arterial vasculature, with improved assessment of the peripheral segments because of the application of a contrast agent.
authors.affiliation: Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Germany. Lale.Umutlu@uk-essen.de
authors.forename: Lale
authors.initials: L
authors.lastname: Umutlu
authors.forename: Nina
authors.initials: N
authors.lastname: Theysohn
authors.forename: Stefan
authors.initials: S
authors.lastname: Maderwald
authors.forename: Sören
authors.initials: S
authors.lastname: Johst
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Lauenstein
authors.forename: Christoph
authors.initials: C
authors.lastname: Moenninghoff
authors.forename: Sophia L
authors.initials: SL
authors.lastname: Goericke
authors.forename: Philipp
authors.initials: P
authors.lastname: Dammann
authors.forename: Karsten H
authors.initials: KH
authors.lastname: Wrede
authors.forename: Mark E
authors.initials: ME
authors.lastname: Ladd
authors.forename: Michael
authors.initials: M
authors.lastname: Forsting
authors.forename: Marc
authors.initials: M
authors.lastname: Schlamann
mesh_terms: D000328:Adult; D002340:Carotid Artery Diseases / Q000473:pathology*; D002536:Cerebral Arteries / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000473:pathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol