title: Susceptibility-weighted imaging of the brain: does gadolinium administration matter?
abstract: OBJECTIVE
  Susceptibility-weighted MR imaging (SWI) is usually obtained without administration of intravenous gadolinium (Gd). However, it is occasionally necessary to perform SWI after Gd is injected. The effects of Gd on SWI have not been systematically examined. The aim of this prospective study was to investigate whether performing SWI after Gd would influence the diagnostic image quality, parenchymal signal and vascular enhancement. An additional aim is to suggest potential future applications for Gd-enhanced SWI.
  
  
  METHODS
  SWI was performed in 31 subjects before and after Gd administration. 17 cases were examined in a 1.5T scanner and the remaining 14 were scanned at 3T. The pre- and post-Gd images were analysed for signal changes in the cerebral grey matter (GM), white matter (WM) as well as for enhancement in the superficial and deep venous system. The visibility of the veins was graded on subtraction maps.
  
  
  RESULTS
  The Gd-enhanced images showed no image quality degradation and no significant signal intensity change in the GM and WM as compared to the pre-Gd images (p>0.05). After Gd-administration significant enhancement of the venous sinuses was noticed (p<0.005), while the deep and cortical veins were poorly enhanced as confirmed by the calculated subtraction maps. The results showed no significant difference at variable MRI field strengths.
  
  
  CONCLUSIONS
  It is possible to perform SWI after Gd injection without information loss or signal change in the parenchyma. The most significant difference is the enhancement of the cerebral venous sinuses. Potential future applications are discussed.
authors.affiliation: Institute of Diagnostic and Interventional Neuroradiology, University Bern, Inselspital, Freiburgstrasse 4, 3010 Bern, Switzerland. marwan.el-koussy@insel.ch
authors.forename: Marwan
authors.initials: M
authors.lastname: El-Koussy
authors.forename: Pascal
authors.initials: P
authors.lastname: Schenk
authors.forename: Claus
authors.initials: C
authors.lastname: Kiefer
authors.forename: Omar M
authors.initials: OM
authors.lastname: Osman
authors.forename: Pasquale
authors.initials: P
authors.lastname: Mordasini
authors.forename: Christoph
authors.initials: C
authors.lastname: Ozdoba
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schroth
authors.forename: Friedrich
authors.initials: F
authors.lastname: Gönner
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000187:drug effects / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol