title: Myocardial perfusion imaging with Gadobutrol: a comparison between 3 and 1.5 Tesla with an identical sequence design.
abstract: OBJECTIVE
  To implement myocardial first-pass perfusion imaging at 3 Tesla and to evaluate the potential benefit with regard to signal parameters in comparison to 1.5 Tesla using identical sequence settings and an intraindividual comparison.
  
  
  METHODS
  In 16 volunteers, myocardial first-pass perfusion imaging was performed at 1.5 Tesla (Magnetom Avanto) and 3 Tesla (Magnetom TIM Trio) after injection of 0.05 mmol/kg body weight Gadobutrol using an accelerated saturation recovery TurboFLASH technique (GRAPPA; R=2) at 1.5 and 3 Tesla. Detailed sequence parameters (TR 2.3 milliseconds, TE 0.93 milliseconds, flip angle 15 degrees , bandwidth 780 Hz/px) as well as spatial resolution were kept identical for both field strengths. Artifacts were assessed quantitatively and qualitatively, signal-to-noise ratio (SNR) and contrast enhancement ratio (CER) were calculated from raw data signal intensity-time curves. A linear fit on the upslope was performed for semiquantitative perfusion analysis.
  
  
  RESULTS
  SNR was significantly higher at 3 Tesla than at 1.5 Tesla (35.7+/-11.9 vs. 18.0+/-5.5, P<0.001). CER was significantly greater at 3 Tesla than at 1.5 Tesla (2.2+/-0.9 vs. 1.4+/-0.5, P<0.001). Maximum upslope was significantly higher at 3 Tesla than at 1.5 Tesla (3.3+/-2.4 vs. 2.0+/-1.0, P<0.001). A qualitative examination of all images for artifacts by 2 board-certified radiologists yielded no significant differences between the field strengths.
  
  
  CONCLUSIONS
  Three Tesla significantly improves CER and SNR compared with 1.5 Tesla with identical sequence parameters. In addition, the most important semiquantitative perfusion parameter maximum upslope is significantly increased. This may allow for an improvement of spatial resolution and potentially for a better delineation of perfusion defects. However, further studies are necessary to potentially demonstrate a benefit of 3 Tesla perfusion imaging in a clinical setting.
authors.affiliation: Department of Clinical Radiology, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany. daniel.theisen@med.uni-muenchen.de
authors.forename: Daniel
authors.initials: D
authors.lastname: Theisen
authors.forename: Bernd J
authors.initials: BJ
authors.lastname: Wintersperger
authors.forename: Armin
authors.initials: A
authors.lastname: Huber
authors.forename: Olaf
authors.initials: O
authors.lastname: Dietrich
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schönberg
mesh_terms: D000328:Adult; D003287:Contrast Media; D003971:Diastole; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium; D009942:Organometallic Compounds; D010477:Perfusion; D019047:Phantoms, Imaging; D012815:Signal Processing, Computer-Assisted; D013599:Systole
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol