title: Brain tumours at 7T MRI compared to 3T--contrast effect after half and full standard contrast agent dose: initial results.
abstract: OBJECTIVE
  To compare the contrast agent effect of a full dose and half the dose of gadobenate dimeglumine in brain tumours at 7 Tesla (7 T) MR versus 3 Tesla (3T).
  
  
  METHODS
  Ten patients with primary brain tumours or metastases were examined. Signal intensities were assessed in the lesion and normal brain. Tumour-to-brain contrast and lesion enhancement were calculated. Additionally, two independent readers subjectively graded the image quality and artefacts.
  
  
  RESULTS
  The enhanced mean tumour-to-brain contrast and lesion enhancement were significantly higher at 7 T than at 3T for both half the dose (91.8 ± 45.8 vs. 43.9 ± 25.3 [p = 0.010], 128.1 ± 53.7 vs. 75.5 ± 32.4 [p = 0.004]) and the full dose (129.2 ± 50.9 vs. 66.6 ± 33.1 [p = 0.002], 165.4 ± 54.2 vs. 102.6 ± 45.4 [p = 0.004]). Differences between dosages at each field strength were also significant. Lesion enhancement was higher with half the dose at 7 T than with the full dose at 3T (p = .037), while the tumour-to-brain contrast was not significantly different. Subjectively, contrast enhancement, visibility, and lesion delineation were better at 7 T and with the full dose. All parameters were rated as good, at the least.
  
  
  CONCLUSIONS
  Half the routine contrast agent dose at 7 T provided higher lesion enhancement than the full dose at 3T which indicates the possibility of dose reduction at 7 T.
  
  
  CONCLUSIONS
  • The contrast effect of gadobenate dimeglumine was assessed at 7 T and 3T. • In brain tumours, contrast effect was higher at 7 T than at 3T. • Tumour-to-brain contrast at 7 T half dose and 3T full dose were comparable. • 7 T half dose lesion enhancement was higher than 3T full dose enhancement. • Our results indicate the possibility of contrast agent dose reduction at 7 T.
authors.affiliation: High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, 1090, Vienna, Austria, iris.noebauer@medunwien.ac.at.
authors.forename: Iris-Melanie
authors.initials: IM
authors.lastname: Noebauer-Huhmann
authors.forename: P
authors.initials: P
authors.lastname: Szomolanyi
authors.forename: C
authors.initials: C
authors.lastname: Kronnerwetter
authors.forename: G
authors.initials: G
authors.lastname: Widhalm
authors.forename: M
authors.initials: M
authors.lastname: Weber
authors.forename: S
authors.initials: S
authors.lastname: Nemec
authors.forename: V
authors.initials: V
authors.lastname: Juras
authors.forename: M E
authors.initials: ME
authors.lastname: Ladd
authors.forename: D
authors.initials: D
authors.lastname: Prayer
authors.forename: S
authors.initials: S
authors.lastname: Trattnig
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D001932:Brain Neoplasms / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008536:Meglumine / Q000008:administration & dosage / Q000031:analogs & derivatives; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage; D011446:Prospective Studies
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine