title: Brain tumor enhancement in magnetic resonance imaging: comparison of signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) at 1.5 versus 3 tesla.
abstract: OBJECTIVE
  The objective of this study was to compare the difference in lesion enhancement between 1.5 and 3 T using an extracellular gadolinium chelate in a rat brain glioma model.
  
  
  METHODS
  Five rats (CDF Fischer 344) with implanted C6/LacZ brain gliomas were evaluated using matched T1-weighted spin echo techniques and hardware configurations at 1.5 and 3 T. Serial imaging over 10 minutes after gadoteridol (ProHance) administration was performed. Contrast enhancement (CE), signal-to-noise ratios (SNR) for brain and tumor, as well as contrast-to-noise ratios (CNR) were evaluated using region-of-interest (ROI) analysis at both field strengths. All gliomas were also evaluated by histopathology.
  
  
  RESULTS
  CE at 3 T increased by 106% to 137% (all P<0.05) with maximum CE occurring at 5 minutes for both 1.5 and 3 T (9.8+/-2.2 vs 21.1+/-3.5; P=0.0004). At 3 T, SNR increased for normal brain by 66% to 76% (P<0.01) and SNR for tumor increased by 70% to 89% (P<0.01). CNR increased by 101% to 137% (P<0.05) depending on the time postcontrast. The highest CNR for both 1.5 T and 3 T occurred 5 minutes after contrast (1.5 T: 9.4+/-1.1 vs 3 T: 20.3+/-2.4; P<0.0004).
  
  
  CONCLUSIONS
  Using a standardized animal model and matched scan techniques, this study shows a significant benefit of 3 T compared with 1.5 T in contrast-enhanced brain tumor magnetic resonance imaging.
authors.affiliation: Department of Radiology, Scott & White Clinic and Hospital, Texas A&M University Health Science Center, Temple, Texas 76508, USA. jbiswas@medicine.tamu.edu
authors.forename: Jonmenjoy
authors.initials: J
authors.lastname: Biswas
authors.forename: C Brett
authors.initials: CB
authors.lastname: Nelson
authors.forename: Val M
authors.initials: VM
authors.lastname: Runge
authors.forename: Bernd J
authors.initials: BJ
authors.lastname: Wintersperger
authors.forename: Shannon S
authors.initials: SS
authors.lastname: Baumann
authors.forename: Carney B
authors.initials: CB
authors.lastname: Jackson
authors.forename: Tushar
authors.initials: T
authors.lastname: Patel
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000473:pathology*; D005260:Female; D005910:Glioma / Q000473:pathology*; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051381:Rats; D011916:Rats, Inbred F344; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity